Zoran Ristovski

Overview and preliminary results of the Surface Ocean Aerosol Production (SOAP) campaign

Publisher: Copernicus GmbH

Date: 16-11-2017

DOI: 10.5194/ACP-17-13645-2017

Abstract: Abstract. Establishing the relationship between marine boundary layer (MBL) aerosols and surface water biogeochemistry is required to understand aerosol and cloud production processes over the remote ocean and represent them more accurately in earth system models and global climate projections. This was addressed by the SOAP (Surface Ocean Aerosol Production) c aign, which examined air–sea interaction over biologically productive frontal waters east of New Zealand. This overview details the objectives, regional context, s ling strategy and provisional findings of a pilot study, PreSOAP, in austral summer 2011 and the following SOAP voyage in late austral summer 2012. Both voyages characterized surface water and MBL composition in three phytoplankton blooms of differing species composition and biogeochemistry, with significant regional correlation observed between chlorophyll a and DMSsw. Surface seawater dimethylsulfide (DMSsw) and associated air–sea DMS flux showed spatial variation during the SOAP voyage, with maxima of 25 nmol L−1 and 100 µmol m−2 d−1, respectively, recorded in a dinoflagellate bloom. Inclusion of SOAP data in a regional DMSsw compilation indicates that the current climatological mean is an underestimate for this region of the southwest Pacific. Estimation of the DMS gas transfer velocity (kDMS) by independent techniques of eddy covariance and gradient flux showed good agreement, although both exhibited periodic deviations from model estimates. Flux anomalies were related to surface warming and sea surface microlayer enrichment and also reflected the heterogeneous distribution of DMSsw and the associated flux footprint. Other aerosol precursors measured included the halides and various volatile organic carbon compounds, with first measurements of the short-lived gases glyoxal and methylglyoxal in pristine Southern Ocean marine air indicating an unidentified local source. The application of a real-time clean sector, contaminant markers and a common aerosol inlet facilitated multi-sensor measurement of uncontaminated air. Aerosol characterization identified variable Aitken mode and consistent submicron-sized accumulation and coarse modes. Submicron aerosol mass was dominated by secondary particles containing ammonium sulfate/bisulfate under light winds, with an increase in sea salt under higher wind speeds. MBL measurements and chamber experiments identified a significant organic component in primary and secondary aerosols. Comparison of SOAP aerosol number and size distributions reveals an underprediction in GLOMAP (GLObal Model of Aerosol Processes)-mode aerosol number in clean marine air masses, suggesting a missing marine aerosol source in the model. The SOAP data will be further examined for evidence of nucleation events and also to identify relationships between MBL composition and surface ocean biogeochemistry that may provide potential proxies for aerosol precursors and production.

Biomass burning and biogenic aerosols in northern Australia during the SAFIRED campaign

Publisher: Copernicus GmbH

Date: 23-03-2017

DOI: 10.5194/ACP-17-3945-2017

Abstract: Abstract. There is a lack of knowledge of how biomass burning aerosols in the tropics age, including those in the fire-prone Northern Territory in Australia. This paper reports chemical characterization of fresh and aged aerosols monitored during the 1-month-long SAFIRED (Savannah Fires in the Early Dry Season) field study, with an emphasis on the chemical signature and aging of organic aerosols. The c aign took place in June 2014 during the early dry season when the surface measurement site, the Australian Tropical Atmospheric Research Station (ATARS), located in the Northern Territory, was heavily influenced by thousands of wild and prescribed bushfires. ATARS was equipped with a wide suite of instrumentation for gaseous and aerosol characterization. A compact time-of-flight aerosol mass spectrometer was deployed to monitor aerosol chemical composition. Approximately 90 % of submicron non-refractory mass was composed of organic material. Ozone enhancement in biomass burning plumes indicated increased air mass photochemistry. The ersity in biomass burning emissions was illustrated through variability in chemical signature (e.g. wide range in f44, from 0.06 to 0.18) for five intense fire events. The background particulate loading was characterized using positive matrix factorization (PMF). A PMF-resolved BBOA (biomass burning organic aerosol) factor comprised 24 % of the submicron non-refractory organic aerosol mass, confirming the significance of fire sources. A dominant PMF factor, OOA (oxygenated organic aerosol), made up 47 % of the s led aerosol, illustrating the importance of aerosol aging in the Northern Territory. Biogenic isoprene-derived organic aerosol factor was the third significant fraction of the background aerosol (28 %).

Engine performance and emissions analysis in a cold, intermediate and hot start diesel engine

Publisher: MDPI AG

Date: 31-05-2020

DOI: 10.3390/APP10113839

Abstract: Presented in this paper is an in-depth analysis of the impact of engine start during various stages of engine warm up (cold, intermediate, and hot start stages) on the performance and emissions of a heavy-duty diesel engine. The experiments were performed at constant engine speeds of 1500 and 2000 rpm on a custom designed drive cycle. The intermediate start stage was found to be longer than the cold start stage. The oil warm up lagged the coolant warm up by approximately 10 °C. During the cold start stage, as the coolant temperature increased from ~25 to 60 °C, the brake specific fuel consumption (BSFC) decreased by approximately 2% to 10%. In the intermediate start stage, as the coolant temperature reached 70 °C and the injection retarded, the indicated mean effective pressure (IMEP) and the brake mean effective pressure (BMEP) decreased by approximately 2% to 3%, while the friction mean effective pressure (FMEP) decreased by approximately 60%. In this stage, the NOx emissions decreased by approximately 25% to 45%, while the HC emissions increased by approximately 12% to 18%. The normalised FMEP showed that higher energy losses at lower loads were most likely contributing to the heating of the lubricating oil.

Measurement report: Understanding the seasonal cycle of Southern Ocean aerosols

Publisher: Copernicus GmbH

Date: 29-03-2023

DOI: 10.5194/ACP-23-3749-2023

Abstract: Abstract. The remoteness and extreme conditions of the Southern Ocean and Antarctic region have meant that observations in this region are rare, and typically restricted to summertime during research or resupply voyages. Observations of aerosols outside of the summer season are typically limited to long-term stations, such as Kennaook / Cape Grim (KCG 40.7∘ S, 144.7∘ E), which is situated in the northern latitudes of the Southern Ocean, and Antarctic research stations, such as the Japanese operated Syowa (SYO 69.0∘ S, 39.6∘ E). Measurements in the midlatitudes of the Southern Ocean are important, particularly in light of recent observations that highlighted the latitudinal gradient that exists across the region in summertime. Here we present 2 years (March 2016–March 2018) of observations from Macquarie Island (MQI 54.5∘ S, 159.0∘ E) of aerosol (condensation nuclei larger than 10 nm, CN10) and cloud condensation nuclei (CCN at various supersaturations) concentrations. This important multi-year data set is characterised, and its features are compared with the long-term data sets from KCG and SYO together with those from recent, regionally relevant voyages. CN10 concentrations were the highest at KCG by a factor of ∼50 % across all non-winter seasons compared to the other two stations, which were similar (summer medians of 530, 426 and 468 cm−3 at KCG, MQI and SYO, respectively). In wintertime, seasonal minima at KCG and MQI were similar (142 and 152 cm−3, respectively), with SYO being distinctly lower (87 cm−3), likely the result of the reduction in sea spray aerosol generation due to the sea ice ocean cover around the site. CN10 seasonal maxima were observed at the stations at different times of year, with KCG and MQI exhibiting January maxima and SYO having a distinct February high. Comparison of CCN0.5 data between KCG and MQI showed similar overall trends with summertime maxima and wintertime minima however, KCG exhibited slightly (∼10 %) higher concentrations in summer (medians of 158 and 145 cm−3, respectively), whereas KCG showed ∼40 % lower concentrations than MQI in winter (medians of 57 and 92 cm−3, respectively). Spatial and temporal trends in the data were analysed further by contrasting data to coincident observations that occurred aboard several voyages of the RSV Aurora Australis and the RV Investigator. Results from this study are important for validating and improving our models and highlight the heterogeneity of this pristine region and the need for further long-term observations that capture the seasonal cycles.

Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

Publisher: Copernicus GmbH

Date: 25-08-2014

DOI: 10.5194/ACPD-14-21659-2014

Abstract: Abstract. Dicarbonyls glyoxal and methylglyoxal have been measured with 2,4-dinitrophenylhydrazine (2,4-DNPH) cartridges and high performance liquid chromatography (HPLC), optimised for dicarbonyl detection, in clean marine air over the temperate Southern Hemisphere (SH) oceans. Measurements of a range of dicarbonyl precursors (volatile organic compounds, VOCs) were made in parallel. These are the first in situ measurements of glyoxal and methylglyoxal over the remote temperate oceans. Six 24 h s les were collected in late summer (February–March) over the Chatham Rise in the South West Pacific Ocean during the Surface Ocean Aerosol Production (SOAP) voyage in 2012, while 34 24 h s les were collected at Cape Grim Baseline Air Pollution Station in late winter (August–September) 2011. Average glyoxal mixing ratios in clean marine air were 7 ppt at Cape Grim, and 24 ppt over Chatham Rise. Average methylglyoxal mixing ratios in clean marine air were 28 ppt at Cape Grim and 12 ppt over Chatham Rise. The mixing ratios of glyoxal at Cape Grim are the lowest observed over the remote oceans, while mixing ratios over Chatham Rise are in good agreement with other temperate and tropical observations, including concurrent MAX-DOAS observations. Methylglyoxal mixing ratios at both sites are comparable to the only other marine methylglyoxal observations available over the tropical Northern Hemisphere (NH) ocean. Ratios of glyoxal : methylglyoxal 1 over Chatham Rise but 1 at Cape Grim, suggesting different formation and/or loss processes or rates dominate at each site. Dicarbonyl precursor VOCs, including isoprene and monoterpenes, are used to calculate an upper estimate yield of glyoxal and methylglyoxal in the remote marine boundary layer and explain at most 1–3 ppt of dicarbonyls observed, corresponding to 11 and 17% of the observed glyoxal and 28 and 10% of the methylglyoxal at Chatham Rise and Cape Grim, respectively, highlighting a significant but as yet unknown production mechanism. Glyoxal surface observations from both sites were converted to vertical columns and compared to average vertical column densities (VCDs) from GOME-2 satellite retrievals. Both satellite columns and in situ observations are higher in summer than winter, however satellite vertical column densities exceeded the surface observations by more than 1.5 × 1014 molecules cm−2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption, or use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much needed data to verify the presence of these short lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

A comparison of particulate matter and gaseous emission factors from two large cargo vessels during manoeuvring conditions

Publisher: Elsevier BV

Date: 11-2019

DOI: 10.1016/J.EGYR.2019.10.001

Physical and Chemical Stability of Bagasse Biocrude from Liquefaction Stored in Real Conditions

Publisher: American Chemical Society (ACS)

Date: 10-11-2016

DOI: 10.1021/ACS.ENERGYFUELS.6B02115

Influence of doping Mg cation in Fe3O4 lattice on its oxygen storage capacity to use as a catalyst for reducing emissions of a compression ignition engine

Publisher: Elsevier BV

Date: 07-2020

DOI: 10.1016/J.FUEL.2020.117728

The Use of a Nitroxide Probe in DMSO to Capture Free Radicals in Particulate Pollution

Publisher: Wiley

Date: 11-09-2012

DOI: 10.1002/EJOC.201200903

On-road CO2 and NOx emissions of a diesel vehicle in urban traffic

Publisher: Elsevier BV

Date: 06-2022

DOI: 10.1016/J.TRD.2022.103326

Fuel properties and emission characteristics of essential oil blends in a compression ignition engine

Publisher: Elsevier BV

Date: 02-2019

DOI: 10.1016/J.FUEL.2018.10.136

Oxidative potential of gas phase combustion emissions - An underestimated and potentially harmful component of air pollution from combustion processes

Publisher: Elsevier BV

Date: 06-2017

DOI: 10.1016/J.ATMOSENV.2017.03.041

Combustion analysis of microalgae methyl ester in a common rail direct injection diesel engine

Publisher: Elsevier BV

Date: 03-2015

DOI: 10.1016/J.FUEL.2014.11.063

Supplementary material to "Aging of aerosols emitted from biomass burning in northern Australia"

Publisher: Copernicus GmbH

Date: 15-08-2016

DOI: 10.5194/ACP-2016-730-SUPPLEMENT

Dust emissions from a tunnel-ventilated broiler poultry shed with fresh and partially reused litter

Publisher: CSIRO Publishing

Date: 2010

DOI: 10.1071/AN09207

Abstract: Dust emissions from large-scale, tunnel-ventilated poultry sheds could have negative health and environmental impacts. Despite this fact, the literature concerning dust emissions from tunnel-ventilated poultry sheds in Australia and overseas is relatively scarce. Dust measurements were conducted during two consecutive production cycles at a single broiler shed on a poultry farm near Ipswich, Queensland. Fresh litter was employed during the first cycle and partially reused litter was employed during the second cycle. This provided an opportunity to study the effect that partial litter reuse has on dust emissions. Dust levels were characterised by the number concentration of suspended particles having a diameter between 0.5 and 20 μm and by the mass concentration of dust particles of less than 10 μm diameter (PM10) and 2.5 μm diameter (PM2.5). In addition, we measured the number size distributions of dust particles. The average concentration and emission rate of dust was higher when partially reused litter was used in the shed than when fresh litter was used. In addition, we found that dust particles emitted from the shed with partially reused litter were finer than the particles emitted with fresh litter. Although the change in litter properties is certainly contributing to this observed variability, other factors such as ventilation rate and litter moisture content are also likely to be involved.

Sea spray aerosol in the Great Barrier Reef and the presence of non-volatile organics

Publisher: American Geophysical Union (AGU)

Date: 22-06-2016

DOI: 10.1002/2016JD024966

The use of artificial neural networks for identifying sustainable biodiesel feedstocks

Publisher: MDPI AG

Date: 29-07-2013

DOI: 10.3390/EN6083764

A review of biomass burning: Emissions and impacts on air quality, health and climate in China

Publisher: Elsevier BV

Date: 02-2017

DOI: 10.1016/J.SCITOTENV.2016.11.025

Abstract: Biomass burning (BB) is a significant air pollution source, with global, regional and local impacts on air quality, public health and climate. Worldwide an extensive range of studies has been conducted on almost all the aspects of BB, including its specific types, on quantification of emissions and on assessing its various impacts. China is one of the countries where the significance of BB has been recognized, and a lot of research efforts devoted to investigate it, however, so far no systematic reviews were conducted to synthesize the information which has been emerging. Therefore the aim of this work was to comprehensively review most of the studies published on this topic in China, including literature concerning field measurements, laboratory studies and the impacts of BB indoors and outdoors in China. In addition, this review provides insights into the role of wildfire and anthropogenic BB on air quality and health globally. Further, we attempted to provide a basis for formulation of policies and regulations by policy makers in China.

Mid‐term outcome in patients with bicuspid aortic valve stenosis following transcatheter aortic valve replacement with a current generation device: A multicenter study

Publisher: Wiley

Date: 04-09-2019

DOI: 10.1002/CCD.28475

Abstract: To perform clinical and echocardiographic follow-up beyond 1 year in consecutive patients with severe bicuspid aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) with a current generation balloon-expandable valve. Treatment of bicuspid aortic valve disease with TAVR remains controversial and late follow-up data is still scarce. We collected baseline characteristics, procedural data, 30-day and mid-term clinical follow-up findings from six centers in Europe and Canada from patients with bicuspid AS treated with TAVR using the SAPIEN 3 valve. Seventy-nine patients underwent TAVR. Mean age was 76 ± 9 years median STS risk score for mortality was 3.8% (interquartile range 2.3-5.5%). Median follow-up was 390 days (interquartile range 138-739 days). Device success was achieved in 95% of patients. Postimplantation mean aortic gradient decreased from 50.2 ± 16.2 to 8.8 ± 4.4 mmHg and no patient had more than mild aortic regurgitation. At last follow-up, there was persistent good valve performance. At 30 days and 1 year, the rates of all-cause mortality were 3.8 and 7.7%, stroke 1.2 and 1.2%, and the rate of new pacemakers 18 and 18%. Our data confirm that treating patients with stenotic bicuspid aortic valves is safe, effective, and has favorable valve performance over time.

Supplementary material to "Biomass burning emissions in north Australia during the early dry season: an overview of the 2014 SAFIRED campaign"

Publisher: Copernicus GmbH

Date: 10-11-2016

DOI: 10.5194/ACP-2016-866-SUPPLEMENT

Gaseous and particle emissions from an ethanol fumigated compression ignition engine

Publisher: Elsevier BV

Date: 02-2012

DOI: 10.1016/J.ENCONMAN.2011.10.011

Composition, size and cloud condensation nuclei activity of biomass burning aerosol from north Australian savannah fires

Publisher: Copernicus GmbH

Date: 07-10-2016

DOI: 10.5194/ACP-2016-867

Abstract: Abstract. The vast majority of Australia's fires occur in the tropical north of the continent during the dry season. These fires are a significant source of aerosol and cloud condensation nuclei (CCN) in the region, providing a unique opportunity to investigate the biomass burning aerosol (BBA) in the absence of other sources. CCN concentrations at 0.5 % supersaturation and aerosol size and chemical properties were measured at the Australian Tropical Atmospheric Research Station (ATARS) during June 2014. CCN concentrations reached over 104 cm−3 when frequent and close fires were burning up to 45 times higher than periods with no fires. Both the size distribution and composition of BBA appeared to significantly influence CCN concentrations. A distinct diurnal trend in the proportion of BBA activating to cloud droplets was observed, with an activation ratio of 40 % ± 20 % during the night and 60 % ± 20 % during the day. BBA was, on average, less hygroscopic during the night (κ = 0.04 ± 0.03) than during the day (κ = 0.07 ± 0.05), with a maximum typically observed just before midday. Size-resolved composition of BBA showed that organics comprised a constant 90 % of the aerosol volume for aerodynamic diameters between 100 nm and 200 nm. The photochemical oxidation of organics led to an increase in the hygroscopic growth and an increase in daytime activation ratios. Modelled CCN concentrations assuming typical continental hygroscopicities produced very large overestimations of up to 200 %. Smaller, but still significant over predictions up to ~100 % were observed using AMS and H-TDMA derived hygroscopicities as well as c aign night and day averages. The largest estimations in every case occurred during the night when the small variations in very weakly hygroscopic species corresponded to large variations in the activation diameters. Trade winds carry the smoke generated from these fires over the Timor Sea where aerosol-cloud interactions are likely to be sensitive to changes in CCN concentrations, perturbing cloud albedo and lifetime. Dry season fires in north Australia are therefore potentially very important in cloud processes in this region.

Influence of fuel composition on polycyclic aromatic hydrocarbon emissions from a fleet of in-service passenger cars

Publisher: Elsevier BV

Date: 2007

DOI: 10.1016/J.ATMOSENV.2006.07.044

Biomass burning emissions in north Australia during the early dry season: an overview of the 2014 SAFIRED campaign

Publisher: Copernicus GmbH

Date: 10-11-2016

DOI: 10.5194/ACP-2016-866

Abstract: Abstract. The SAFIRED (Savannah Fires in the Early Dry Season) c aign took place from 29th of May, 2014 until the 30th June, 2014 at the Australian Tropical Atmospheric Research Station (ATARS) in the Northern Territory, Australia. The purpose of this c aign was to investigate emissions from fires in the early dry season in northern Australia. Measurements were made of biomass burning aerosols, volatile organic compounds, polycyclic aromatic carbons, greenhouse gases, radon, mercury cycle, and trace metals. Aspects of the biomass burning aerosol emissions investigated included emission factors of various emitted species, physical and chemical aerosol properties, aerosol aging, micronutrient supply to the ocean, nucleation, and aerosol water uptake. Over the course of the month-long c aign, biomass burning signals were prevalent and emissions from several large single burning events were observed at ATARS. Biomass burning emissions dominated the gas and aerosol concentrations in this region. Nine major biomass burning events were identified and associated with intense or close in idual smoke plumes. Dry season fires are extremely frequent and widespread across the northern region of Australia, which suggests that the measured aerosol and gaseous emissions at ATARS are likely representative of signals across the entire region of north Australia. Air mass forward trajectories show that these biomass burning emissions are carried north west over the Timor Sea and could influence the atmosphere over Indonesia and the tropical atmosphere over the Indian Ocean. The outcomes of this c aign will be numerous. This region is an environment with little human impact and provides a unique look into the characteristics of biomass burning aerosol without the influence of other significant emission sources. Relationships between the aerosol physical and chemical properties, gas concentrations and meteorological data for the entire month will provide fundamental knowledge required to understand the influence of early dry season burning in this tropical region on the atmosphere. In this paper we present characteristics of the biomass burning observed at the s ling site and provide an overview of the more specific outcomes of the SAFIRED c aign.

Concentration and oxidative potential of on-road particle emissions and their relationship with traffic composition: Relevance to exposure assessment

Publisher: Elsevier BV

Date: 11-2012

DOI: 10.1016/J.ATMOSENV.2012.05.039

Particulate emissions from a petrol to CNG converted spark ignition vehicle

Publisher: Elsevier BV

Date: 09-2000

DOI: 10.1016/S0021-8502(00)90633-5

Influence of medium range transport of particles from nucleation burst on particle number concentration within the urban airshed

Publisher: Copernicus GmbH

Date: 07-06-2012

DOI: 10.5194/ACP-12-4951-2012

Abstract: Abstract. An elevated particle number concentration (PNC) observed during nucleation events could play a significant contribution to the total particle load and therefore to the air pollution in the urban environments. Therefore, a field measurement study of PNC was commenced to investigate the temporal and spatial variations of PNC within the urban airshed of Brisbane, Australia. PNC was monitored at urban (QUT), roadside (WOO) and semi-urban (ROC) areas around the Brisbane region during 2009. During the morning traffic peak period, the highest relative fraction of PNC reached about 5% at QUT and WOO on weekdays. PNC peaks were observed around noon, which correlated with the highest solar radiation levels at all three stations, thus suggesting that high PNC levels were likely to be associated with new particle formation caused by photochemical reactions. Wind rose plots showed relatively higher PNC for the NE direction, which was associated with industrial pollution, accounting for 12%, 9% and 14% of overall PNC at QUT, WOO and ROC, respectively. Although there was no significant correlation between PNC at each station, the variation of PNC was well correlated among three stations during regional nucleation events. In addition, PNC at ROC was significantly influenced by upwind urban pollution during the nucleation burst events, with the average enrichment factor of 15.4. This study provides an insight into the influence of regional nucleation events on PNC in the Brisbane region and it the first study to quantify the effect of urban pollution on semi-urban PNC through the nucleation events.

Exploratory cross-sectional investigations on ambient submicrometer particles in Salzburg, Austria

Publisher: Elsevier BV

Date: 07-2004

DOI: 10.1016/J.ATMOSENV.2004.03.024

Performance and gaseous and particle emissions from a liquefied petroleum gas (LPG) fumigated compression ignition engine

Publisher: Elsevier BV

Date: 10-2014

DOI: 10.1016/J.FUEL.2014.04.093

Particulate number emissions during cold-start with diesel and biofuels

Publisher: Elsevier BV

Date: 06-2022

DOI: 10.1016/J.SETA.2022.101953

Critical Analysis of High Particle Number Emissions from Accelerating Compressed Natural Gas Buses

Publisher: American Chemical Society (ACS)

Date: 15-05-2010

DOI: 10.1021/ES1003186

Abstract: Compressed natural gas (CNG) engines are thought to be less harmful to the environment than conventional diesel engines, especially in terms of particle emissions. Although, this is true with respect to particulate matter (PM) emissions, results of particle number (PN) emission comparisons have been inconclusive. In this study, results of on-road and dynamometer studies of buses were used to derive several important conclusions. We show that, although PN emissions from CNG buses are significantly lower than from diesel buses at low engine power, they become comparable at high power. For diesel buses, PN emissions are not significantly different between acceleration and operation at steady maximum power. However, the corresponding PN emissions from CNG buses when accelerating are an order of magnitude greater than when operating at steady maximum power. During acceleration under heavy load, PN emissions from CNG buses are an order of magnitude higher than from diesel buses. The particles emitted from CNG buses are too small to contribute to PM(10) emissions or contribute to a reduction of visibility and may consist of semivolatile nanoparticles.

A comparative investigation into cold-start and hot-start operation of diesel engine performance with oxygenated fuels during transient and steady-state operation

Publisher: Elsevier BV

Date: 09-2018

DOI: 10.1016/J.FUEL.2018.05.004

Experimental investigation of diesel engine performance, combustion and emissions using a novel series of dioctyl phthalate (DOP) biofuels derived from microalgae

Publisher: MDPI AG

Date: 22-05-2019

DOI: 10.3390/EN12101964

Abstract: Physico-chemical properties of microalgae biodiesel depend on the microalgae species and oil extraction method. Dioctyl phthalate (DOP) is a clear, colourless and viscous liquid as a plasticizer. It is used in the processing of polyvinyl chloride (PVC) resin and polymers. A new potential biofuel, hydrothermally liquefied microalgae bio-oil can contain nearly 11% (by mass) of DOP. This study investigated the feasibility of using up to 20% DOP blended in 80% diesel fuel (v/v) in an existing diesel engine, and assessed the performance and exhaust emissions. Despite reasonable differences in density, viscosity, surface tension, and boiling point, blends of DOP and diesel fuel were found to be entirely miscible and no separation was observed at any stage during prolonged miscibility tests. The engine test study found a slight decrease in peak cylinder pressure, brake, and indicated mean effective pressure, indicated power, brake power, and indicated and brake thermal efficiency with DOP blended fuels, where the specific fuel consumption increased. This is due to the presence of 16.4% oxygen in neat DOP, responsible for the relatively lower heating value, compared to that of diesel. The emission tests revealed a slight increase in nitrogen oxides (NOx) and carbon monoxide (CO) emissions from DOP blended fuels. However, particulate matter (PM) emissions were lower from DOP blended fuels, although some inconsistency in particle number (PN) was present among different engine loads.

Particle exposure level and potential health risks of domestic Chinese cooking

Publisher: Elsevier BV

Date: 10-2017

DOI: 10.1016/J.BUILDENV.2017.07.031

Sea spray aerosol organic enrichment, water uptake and surface tension effects

Publisher: Copernicus GmbH

Date: 09-07-2020

DOI: 10.5194/ACP-20-7955-2020

Abstract: Abstract. The aerosol-driven radiative effects on marine low-level cloud represent a large uncertainty in climate simulations, in particular over the Southern Ocean, which is also an important region for sea spray aerosol production. Observations of sea spray aerosol organic enrichment and the resulting impact on water uptake over the remote Southern Hemisphere are scarce, and therefore the region is under-represented in existing parameterisations. The Surface Ocean Aerosol Production (SOAP) voyage was a 23 d voyage which s led three phytoplankton blooms in the highly productive water of the Chatham Rise, east of New Zealand. In this study we examined the enrichment of organics to nascent sea spray aerosol and the modifications to sea spray aerosol water uptake using in situ chamber measurements of seawater s les taken during the SOAP voyage. Primary marine organics contributed up to 23 % of the sea spray mass for particles with diameter less than approximately 1 µm and up to 79 % of the particle volume for 50 nm diameter sea spray. The composition of the submicron organic fraction was consistent throughout the voyage and was largely composed of a polysaccharide-like component, characterised by very low alkane-to-hydroxyl-concentration ratios of approximately 0.1–0.2. The enrichment of organics was compared to the output from the chlorophyll-a-based sea spray aerosol parameterisation suggested by Gantt et al. (2011) and the OCEANFILMS (Organic Compounds from Ecosystems to Aerosols: Natural Films and Interfaces via Langmuir Molecular Surfactants) models. OCEANFILMS improved on the representation of the organic fraction predicted using chlorophyll a, in particular when the co-adsorption of polysaccharides was included however, the model still under-predicted the proportion of polysaccharides by an average of 33 %. Nascent 50 nm diameter sea spray aerosol hygroscopic growth factors measured at 90 % relative humidity averaged 1.93±0.08 and did not decrease with increasing sea spray aerosol organic fractions. The observed hygroscopicity was greater than expected from the assumption of full solubility, particularly during the most productive phytoplankton bloom (B1), during which organic fractions were greater than approximately 0.4. The water uptake behaviour observed in this study is consistent with that observed for other measurements of phytoplankton blooms and can be partially attributed to the presence of sea salt hydrates, which lowers the sea spray aerosol hygroscopicity when the organic enrichment is low. The inclusion of surface tension effects only marginally improved the modelled hygroscopicity, and a significant discrepancy between the observed and modelled hygroscopicity at high organic volume fractions remained. The findings from the SOAP voyage highlight the influence of biologically sourced organics on sea spray aerosol composition these data improve the capacity to parameterise sea spray aerosol organic enrichment and water uptake.

Morphological and Nanostructural Characteristics of Diesel Exhaust Soot Particles at Different Engine Operating Conditions

Publisher: Springer Nature Singapore

Date: 2022

DOI: 10.1007/978-981-16-8341-1_33

Particle and carbon dioxide emissions from passenger vehicles operating on unleaded petrol and LPG fuel

Publisher: Elsevier BV

Date: 06-2005

DOI: 10.1016/J.SCITOTENV.2004.10.021

Abstract: A comprehensive study of the particle and carbon dioxide emissions from a fleet of six dedicated liquefied petroleum gas (LPG) powered and five unleaded petrol (ULP) powered new Ford Falcon Forte passenger vehicles was carried out on a chassis dynamometer at four different vehicle speeds--0 (idle), 40, 60, 80 and 100 km h(-1). Emission factors and their relative values between the two fuel types together with a statistical significance for any difference were estimated for each parameter. In general, LPG was found to be a 'cleaner' fuel, although in most cases, the differences were not statistically significant owing to the large variations between emissions from different vehicles. The particle number emission factors ranged from 10(11) to 10(13) km(-1) and was over 70% less with LPG compared to ULP. Corresponding differences in particle mass emission factor between the two fuels were small and ranged from the order of 10 microg km(-1) at 40 to about 1000 microg km(-1) at 100 km h(-1). The count median particle diameter (CMD) ranged from 20 to 35 nm and was larger with LPG than with ULP in all modes except the idle mode. Carbon dioxide emission factors ranged from about 300 to 400 g km(-1) at 40 km h(-1), falling with increasing speed to about 200 g km(-1) at 100 km h(-1). At all speeds, the values were 10% to 18% greater with ULP than with LPG.

On the use of small and cheaper sensors and devices for indicative citizen-based monitoring of respirable particulate matter

Publisher: Elsevier BV

Date: 11-2015

DOI: 10.1016/J.ENVPOL.2015.08.035

Abstract: Respirable particulate matter present in outdoor and indoor environments is a health hazard. The particle concentrations can quickly change, with steep gradients on short temporal and spatial scales, and their chemical composition and physical properties vary considerably. Existing networks of aerosol particle measurements consist of limited number of monitoring stations, and mostly aim at assessment of compliance with air quality legislation regulating mass of particles of varying sizes. These networks can now be supplemented using small portable devices with low-cost sensors for assessment of particle mass that may provide higher temporal and spatial resolution if we understand the capabilities and characteristics of the data they provide. This paper overviews typical currently available devices and their characteristics. In addition it is presented original results of measurement and modelling in the aim of one low-cost PM monitor validation.

The effect of triacetin as a fuel additive to waste cooking biodiesel on engine performance and exhaust emissions

Publisher: Elsevier BV

Date: 10-2016

DOI: 10.1016/J.FUEL.2016.06.039

Influence of non-thermal plasma after-treatment technology on diesel engine particulate matter composition and NOx concentration

Publisher: Springer Science and Business Media LLC

Date: 04-08-2016

DOI: 10.1007/S13762-015-0865-3

Atmospheric Trace Metal Deposition near the Great Barrier Reef, Australia

Publisher: MDPI AG

Date: 15-04-2020

DOI: 10.3390/ATMOS11040390

Abstract: Aerosols deposited into the Great Barrier Reef (GBR) contain iron (Fe) and other trace metals, which may act as micronutrients or as toxins to this sensitive marine ecosystem. In this paper, we quantified the atmospheric deposition of Fe and investigated aerosol sources in Mission Beach (Queensland) next to the GBR. Leaching experiments were applied to distinguish pools of Fe with regard to its solubility. The labile Fe concentration in aerosols was 2.3–10.6 ng m−3, which is equivalent to 4.9%–11.4% of total Fe and was linked to combustion and biomass burning processes, while total Fe was dominated by crustal sources. A one-day precipitation event provided more soluble iron than the average dry deposition flux, 0.165 and 0.143 μmol m−2 day−1, respectively. Scanning Electron Microscopy indicated that alumina-silicates were the main carriers of total Fe and s les affected by combustion emissions were accompanied by regular round-shaped carbonaceous particulates. Collected aerosols contained significant amounts of Cd, Co, Cu, Mo, Mn, Pb, V, and Zn, which were mostly (47.5%–96.7%) in the labile form. In this study, we provide the first field data on the atmospheric delivery of Fe and other trace metals to the GBR and propose that this is an important delivery mechanism to this region.

Global impacts of recent IMO regulations on marine fuel oil refining processes and ship emissions

Publisher: Elsevier BV

Date: 05-2019

DOI: 10.1016/J.TRD.2019.04.001

Biomass burning emissions in north Australia during the early dry season: an overview of the 2014 SAFIRED campaign

Publisher: Copernicus GmbH

Date: 17-11-2017

DOI: 10.5194/ACP-17-13681-2017

Abstract: Abstract. The SAFIRED (Savannah Fires in the Early Dry Season) c aign took place from 29 May until 30 June 2014 at the Australian Tropical Atmospheric Research Station (ATARS) in the Northern Territory, Australia. The purpose of this c aign was to investigate emissions from fires in the early dry season in northern Australia. Measurements were made of biomass burning aerosols, volatile organic compounds, polycyclic aromatic carbons, greenhouse gases, radon, speciated atmospheric mercury and trace metals. Aspects of the biomass burning aerosol emissions investigated included emission factors of various species, physical and chemical aerosol properties, aerosol aging, micronutrient supply to the ocean, nucleation, and aerosol water uptake. Over the course of the month-long c aign, biomass burning signals were prevalent and emissions from several large single burning events were observed at ATARS.Biomass burning emissions dominated the gas and aerosol concentrations in this region. Dry season fires are extremely frequent and widespread across the northern region of Australia, which suggests that the measured aerosol and gaseous emissions at ATARS are likely representative of signals across the entire region of north Australia. Air mass forward trajectories show that these biomass burning emissions are carried north-west over the Timor Sea and could influence the atmosphere over Indonesia and the tropical atmosphere over the Indian Ocean. Here we present characteristics of the biomass burning observed at the s ling site and provide an overview of the more specific outcomes of the SAFIRED c aign.

Aging of aerosols emitted from biomass burning in northern Australia

Publisher: Copernicus GmbH

Date: 15-08-2016

DOI: 10.5194/ACP-2016-730

Abstract: Abstract. There is a lack of knowledge of how biomass burning aerosols in the tropics age, including those in the fire-prone Northern Territory in Australia. This paper reports chemical characterization and aging of aerosols monitored during the one month long SAFIRED (Savannah Fires in the Early Dry Season) field study, with an emphasis on chemical signature and aging of organic aerosols. The c aign took place in June 2014 during the early dry season when the surface measurement site, the Australian Tropical Atmospheric Research Station (ATARS), located in the Northern Territory, was heavily influenced by thousands of wild and prescribed bushfires. ATARS was equipped with a wide suite of instrumentation for gaseous and aerosol characterization. A compact time-of-flight aerosol mass spectrometer was deployed to monitor aerosol chemical composition. Approximately 80 % of submicron carbonaceous mass and 90 % of submicron non-refractory mass was composed of organic material. Ozone enhancement in biomass burning plumes indicated increased air mass photochemistry and increased organic aerosol and particle diameter with the aging parameter (f44) suggested secondary organic aerosol formation. Diversity of biomass burning emissions was illustrated through variability in chemical signature (e.g. wide range in f44, from 0.06 to 0.13) for five intense fire events. The background particulate loading was characterized using Positive Matrix Factorization (PMF). A PMF-resolved BBOA (biomass burning organic aerosol) factor comprised 24 % of the submicron non-refractory organic aerosol mass, confirming the significance of fire sources. A dominant PMF factor, OOA (oxygenated organic aerosol), made up 47 % of s led aerosol fraction, illustrating the importance of aerosol aging in the Northern Territory. Biogenic IEPOX-SOA (isoprene epoxydiols-related secondary organic aerosol) was the third significant fraction of the background aerosol (28 %).

Performance and Combustion Characteristics Analysis of Multi-Cylinder CI Engine Using Essential Oil Blends

Publisher: MDPI AG

Date: 24-03-2018

DOI: 10.3390/EN11040738

To Sonicate or Not to Sonicate PM Filters: Reactive Oxygen Species Generation Upon Ultrasonic Irradiation

Publisher: Informa UK Limited

Date: 20-11-2014

DOI: 10.1080/02786826.2014.981330

An Overview of the Surface Ocean Aerosol Production (SOAP) campaign

Publisher: Copernicus GmbH

Date: 20-06-2017

DOI: 10.5194/ACP-2017-535

Abstract: Abstract. Establishing the relationship between marine boundary layer (MBL) aerosols and surface water biogeochemistry over the remote ocean is required to understand aerosol and cloud production processes, and also represent them accurately in Earth System Models and global climate projections. This was addressed in the SOAP (Surface Ocean Aerosol Production) c aign, which examined air-sea interaction over biologically-productive frontal waters east of New Zealand. This overview details the objectives, regional context, s ling strategy, and provisional findings of a pilot study, PreSOAP, in austral summer 2011, and the following SOAP voyage in late austral summer 2012. Both voyages characterised surface water and MBL composition in three phytoplankton blooms of differing species composition and biogeochemistry, with significant regional correlation observed between chlorophyll-a and DMSsw. Surface seawater dimethylsulfide (DMSsw) and associated air-sea DMS flux showed spatial variation during the SOAP voyage, with maxima of 25 nmol L−1 and 100 µmol m−2 d−1, respectively, recorded in a dinoflagellate bloom. Inclusion of SOAP data in a regional DMSsw compilation confirmed that the current climatological mean is an underestimate for this region of the South-west Pacific. Estimation of the DMS gas transfer velocity (kDMS) by independent techniques of eddy covariance and gradient flux showed good agreement, although both exhibited periodic deviations from model estimates. Flux anomalies were related to surface warming and sea surface microlayer enrichment, and also reflected the heterogeneous distribution of DMSsw and the associated flux footprint. Other aerosol precursors measured included the halides and various volatile organic carbon compounds, with the first measurements of the short-lived gases glyoxal and methylglyoxal in pristine Southern Ocean marine air indicating an unidentified local source. The application of a real-time clean-sector, contaminant markers, and a common aerosol inlet facilitated multi-sensor measurement of uncontaminated air. Aerosol characterisation identified variable Aitken mode, and consistent sub-micron sized accumulation and coarse modes. Sub-micron aerosol mass was dominated by secondary particles containing ammonium sulfate/bisulfate under light winds, with an increase in sea-salt under higher wind-speeds. MBL measurements and chamber experiments identified a significant organic component in primary and secondary aerosols. Comparison of SOAP aerosol number and size distributions reveals an underprediction in GLOMAP-mode aerosol number in clean marine air masses, suggesting a missing marine aerosol source in the model. The SOAP data will be further examined for evidence of nucleation events, and also for relationships between MBL composition and surface ocean biogeochemistry with the aim of identifying potential proxies for aerosol precursors and production.

Observation of the suppression of water uptake by marine particles

Publisher: Elsevier BV

Date: 11-2010

DOI: 10.1016/J.ATMOSRES.2010.03.025

Particulate matter research and management in Serbia

Publisher: National Library of Serbia

Date: 2023

DOI: 10.2298/TSCI230300XIJ

Abstract: nema

Supplementary material to "Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania, 41° S"

Publisher: Copernicus GmbH

Date: 07-2015

DOI: 10.5194/ACPD-15-17599-2015-SUPPLEMENT

Shipping emissions and their impacts on air quality in China

Publisher: Elsevier BV

Date: 03-2017

DOI: 10.1016/J.SCITOTENV.2016.12.098

Abstract: China has >400 ports, is home to 7 of 10 biggest ports in the world and its waterway infrastructure construction has been accelerating over the past years. But the increasing number of ports and ships means increasing emissions, and in turn, increasing impact on local and regional air pollution. This paper presents an overview of the broad field of ship emissions in China and their atmospheric impacts, including topics of ship engine emissions and control, ship emission factors and their measurements, developing of ship emission inventories, shipping and port emissions of the main shipping areas in China, and quantitative contribution of shipping emissions to the local and regional air pollution. There have been an increasing number of studies published on all the above aspects, yet, this review identified some critical research gaps, filling of which is necessary for better control of ship emissions, and for lowering their impacts. In particular, there are very few studies on inland ports and river ships, and there are few national scale ship emission inventories available for China. While advanced method to estimate ship emission based on ship AIS activities makes it now possible to develop high spatial- and temporal-resolution emission inventories, the ship emission factors used in Chinese studies have been based mainly on foreign measurements. Further, the contribution of ship emissions to air pollution in coastal cities, the dispersion of pollution plumes emitted by ships, or the chemical evolution process along the transmission path, have so far not been systematically studied in China.

Morphology and nanostructure of soot particles from diesel engine under transient and steady-state operating conditions with a microalgae fuel component, dioctyl phthalate biofuel

Publisher: Elsevier BV

Date: 12-2023

DOI: 10.1016/J.SETA.2023.103504

Euler-Lagrange Prediction of Diesel-Exhaust Polydisperse Particle Transport and Deposition in Lung: Anatomy and Turbulence Effects

Publisher: Springer Science and Business Media LLC

Date: 27-08-2019

DOI: 10.1038/S41598-019-48753-6

Abstract: In clinical assessments, the correlation between atmospheric air pollution and respiratory damage is highly complicated. Epidemiological studies show that atmospheric air pollution is largely responsible for the global proliferation of pulmonary disease. This is particularly significant, since most Computational Fluid Dynamics (CFD) studies to date have used monodisperse particles, which may not accurately reflect realistic inhalation patterns, since atmospheric aerosols are mostly polydisperse. The aim of this study is to investigate the anatomy and turbulent effects on polydisperse particle transport and deposition (TD) in the upper airways. The Euler-Lagrange approach is used for polydisperse particle TD prediction in both laminar and turbulent conditions. Various anatomical models are adopted to investigate the polydisperse particle TD under different flow conditions. Rossin-Rammler diameter distribution is used for the distribution of the initial particle diameter. The numerical results illustrate that airflow rate distribution at the right lung of a realistic model is higher than a non-realistic model. The CFD study also shows that turbulence effects on deposition are higher for larger diameter particles than with particles of smaller diameter. A significant amount of polydisperse particles are also shown to be deposited at the tracheal wall for CT-based model, whereas particles are mostly deposited at the carinal angle for the non-realistic model. A comprehensive, polydisperse particle TD analysis would enhance understanding of the realistic deposition pattern and decrease unwanted therapeutic aerosol deposition at the extrathoracic airways.

ON-ROAD SAMPLING TECHNIQUE FOR VEHICLE EMISSION MEASUREMENTS

Publisher: Elsevier BV

Date: 07-2004

DOI: 10.1016/S0021-8502(19)30169-7

Biomass burning influenced particle characteristics in Northern Territory Australia based on airborne measurements

Publisher: Elsevier BV

Date: 04-2010

DOI: 10.1016/J.ATMOSRES.2009.12.002

On-board measurements of particle and gaseous emissions from a large cargo vessel at different operating conditions

Publisher: Elsevier BV

Date: 06-2018

DOI: 10.1016/J.ENVPOL.2017.11.008

Abstract: This study investigated particle and gaseous emission factors from a large cargo vessel for her whole voyage including at berth, manoeuvring and cruising. Quantification of these factors assists in minimising the uncertainty in the current methods of exhaust gas emission factor estimation. Engine performance and emissions from the main marine engine were measured on-board while the ship was manoeuvring and cruising at sea. Emissions of an auxiliary engine working at 55% of maximum continuous rating (MCR) were measured when the ship was at actual harbour stopovers. Gaseous and particle emission factors in this study are presented in g kWh

Structural characterisation of soot particles for cold and hot-start operation of a diesel engine

Publisher: The University of Queensland

Date: 11-12-2020

DOI: 10.14264/183B6CF

Measurement Report: Understanding the seasonal cycle of Southern Ocean aerosols

Publisher: Copernicus GmbH

Date: 07-09-2022

DOI: 10.5194/ACP-2022-568

Abstract: Abstract. The remoteness and extreme conditions of the Southern Ocean and Antarctic region have meant that observations in this region are rare, and typically restricted to summertime during research or resupply voyages. Observations of aerosols outside of the summer season are typically limited to long-term stations, such as Kennaook/Cape Grim (KCG, 40.7° S, 144.7° E) which is situated in the northern latitudes of the Southern Ocean, and Antarctic research stations, such as the Japanese operated Syowa (SYO, 69.0° S, 39.6° E). Measurements in the mid-latitudes of the Southern Ocean are important, particularly in light of recent observations that highlighted the latitudinal gradient that exists across the region in summertime. Here we present two years (March 2016–March 2018) of observations from Macquarie Island (MQI, 54.5° S, 159.0° E) of aerosol (condensation nuclei larger than 10 nm, CN10) and cloud condensation nuclei (CCN at various supersaturations) concentrations. This important multi-year data set is characterised, and its features are compared with the long-term data sets from KCG and SYO together with those from recent, regionally relevant voyages. CN10 concentrations were the highest at KCG by a factor of ∼50 % across all non-winter seasons compared to the other two stations which were similar (summer medians of 530 cm-3, 426 cm-3 and 468 cm-3 at KCG, MQI and SYO, respectively). In wintertime, seasonal minima at KCG and MQI were similar (142 cm-3 and 152 cm-3, respectively), with SYO being distinctly lower (87 cm-3), likely the result of the reduction in sea spray aerosol generation due to the sea-ice ocean cover around the site. CN10 seasonal maxima were observed at the stations at different times of year, with KCG and MQI exhibiting January maxima and SYO having a distinct February high. Comparison of CCN0.5 data between KCG and MQI showed similar overall trends with summertime maxima and wintertime minima, however KCG exhibited slightly (∼10 %) higher concentrations in summer (medians of 158 cm-3 and 145 cm-3, respectively), whereas KCG showed ∼40 % lower concentrations than MQI in winter (medians of 57 cm-3 and 92 cm-3, respectively). Spatial and temporal trends in the data were analysed further by contrasting data to coincident observations that occurred aboard several voyages of the RSV Aurora Australis and the RV Investigator. Results from this study are important for validating and improving our models, highlight the heterogeneity of this pristine region, and the need for further long-term observations that capture the seasonal cycles.

Assessment and application of clustering techniques to atmospheric particle number size distribution for the purpose of source apportionment

Publisher: Copernicus GmbH

Date: 11-06-2014

DOI: 10.5194/ACPD-14-15257-2014

Abstract: Abstract. Long-term measurements of particle number size distribution (PNSD) produce a very large number of observations and their analysis requires an efficient approach in order to produce results in the least possible time and with maximum accuracy. Clustering techniques are a family of sophisticated methods which have been recently employed to analyse PNSD data, however, very little information is available comparing the performance of different clustering techniques on PNSD data. This study aims to apply several clustering techniques (i.e. K-means, PAM, CLARA and SOM) to PNSD data, in order to identify and apply the optimum technique to PNSD data measured at 25 sites across Brisbane, Australia. A new method, based on the Generalised Additive Model (GAM) with a basis of penalised B-splines, was proposed to parameterise the PNSD data and the temporal weight of each cluster was also estimated using the GAM. In addition, each cluster was associated with its possible source based on the results of this parameterisation, together with the characteristics of each cluster. The performances of four clustering techniques were compared using the Dunn index and silhouette width validation values and the K-means technique was found to have the highest performance, with five clusters being the optimum. Therefore, five clusters were found within the data using the K-means technique. The diurnal occurrence of each cluster was used together with other air quality parameters, temporal trends and the physical properties of each cluster, in order to attribute each cluster to its source and origin. The five clusters were attributed to three major sources and origins, including regional background particles, photochemically induced nucleated particles and vehicle generated particles. Overall, clustering was found to be an effective technique for attributing each particle size spectra to its source and the GAM was suitable to parameterise the PNSD data. These two techniques can help researchers immensely in analysing PNSD data for characterisation and source apportionment purposes.

Supplementary material to "Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols"

Publisher: Copernicus GmbH

Date: 27-11-2019

DOI: 10.5194/ACP-2019-1081-SUPPLEMENT

Review on the Use of Essential Oils in Compression Ignition Engines

Publisher: Springer Singapore

Date: 02-11-2019

DOI: 10.1007/978-981-13-3287-6_8

Photoacoustic properties of softmagnetic amorphous Fe81B13Si4C2 ribbon

Publisher: Springer Science and Business Media LLC

Date: 04-1998

DOI: 10.1023/A:1004330027196

Application of profluorescent nitroxides for measurements of oxidative capacity of combustion generated particles

Publisher: National Library of Serbia

Date: 2012

DOI: 10.2298/CICEQ120113113S

Abstract: Oxidative stress caused by generation of free radicals and related reactive oxygen species (ROS) at the sites of deposition has been proposed as a mechanism for many of the adverse health outcomes associated with exposure to particulate matter (PM). Recently, a new profluorescent nitroxide molecular probe (BPEAnit) developed at QUT was applied in an entirely novel, rapid and non-cell based assay for assessing the oxidative potential of particles (i.e. potential of particles to induce oxidative stress). The technique was applied on particles produced by several combustion sources, namely cigarette smoke, diesel exhaust and wood smoke. One of the main findings from the initial studies undertaken at QUT was that the oxidative potential per PM mass significantly varies for different combustion sources as well as the type of fuel used and combustion conditions. However, possibly the most important finding from our studies was that there was a strong correlation between the organic fraction of particles and the oxidative potential measured by the PFN assay, which clearly highlights the importance of organic species in particle-induced toxicity.

In situ measurements of human cough aerosol hygroscopicity

Publisher: The Royal Society

Date: 05-2021

DOI: 10.1098/RSIF.2021.0209

Abstract: The airborne dynamics of respiratory droplets, and the transmission routes of pathogens embedded within them, are governed primarily by the diameter of the particles. These particles are composed of the fluid which lines the respiratory tract, and is primarily mucins and salts, which will interact with the atmosphere and evaporate to reach an equilibrium diameter. Measuring organic volume fraction (OVF) of cough aerosol has proved challenging due to large variability and low material volume produced after coughing. Here, the diametric hygroscopic growth factors (GF) of the cough aerosol produced by healthy participants were measured in situ using a rotating aerosol suspension chamber and a humidification tandem differential mobility analyser. Using hygroscopicity models, it was estimated that the average OVF in the evaporated cough aerosol was 0.88 ± 0.07 and the average GF at 90% relative humidity (RH) was 1.31 ± 0.03. To reach equilibrium in dry air the droplets will reduce in diameter by a factor of approximately 2.8 with an evaporation factor of 0.36 ± 0.05. Hysteresis was observed in cough aerosol at RH = ∼35% and RH = ∼65% for efflorescence and deliquescence, respectively, and may depend on the OVF. The same behaviour and GF were observed in nebulized bovine bronchoalveolar lavage fluid.

Characterization of expiration air jets and droplet size distributions immediately at the mouth opening

Publisher: Elsevier BV

Date: 02-2009

DOI: 10.1016/J.JAEROSCI.2008.10.003

Novel biofuels derived from waste tyres and their effects on reducing oxides of nitrogen and particulate matter emissions

Publisher: Elsevier BV

Date: 2020

DOI: 10.1016/J.JCLEPRO.2019.118463

Exergy and energy analysis during cold-start and warm-up engine operation

Publisher: Elsevier BV

Date: 12-2022

DOI: 10.1016/J.FUEL.2022.125580

Comparison of light absorption and oxidative potential of biodiesel/diesel and chemicals/diesel blends soot particles

Publisher: Elsevier BV

Date: 2020

DOI: 10.1016/J.JES.2019.06.014

Abstract: Soot particles, mainly coming from fuel combustion, affect climate forcing through absorbing light and also result in adverse human health outcomes. Though biodiesel or additives blending with diesel was considered environmentally friendly, the understanding on absorbing and oxidative capacity of soot emitted from them are still unclear. The water-soluble organic carbon (WSOC) content, surface chemical structure, light absorption and oxidative potential (OP

A Comparative Investigation of Ultrafine Particle Number and Mass Emissions from a Fleet of On-Road Diesel and CNG Buses

Publisher: American Chemical Society (ACS)

Date: 22-07-2008

DOI: 10.1021/ES800394X

Abstract: Particle number, particle mass, and CO2 concentrations were measured on the curb of a busy urban busway used entirely by a mix of diesel and CNG operated buses. With the passage of each bus, the ratio of particle number concentration and particle mass concentration to CO2 concentration in the diluted exhaust plume were used as measures of the particle number and mass emission factors, respectively. With all buses accelerating pastthe monitoring point, the results showed that the median particle mass emission from CNG buses was less than 9% of that from diesel buses. However, the median particle number emission from CNG buses was 6 times higher than the diesel buses, and the particles from the CNG buses were mainly in the nanoparticle size range. Using a thermodenuder to remove the volatile material from the s led emissions showed that the majority of particles from the CNG buses, but not from the diesel buses, were volatile. Approximately, 82% of the particles from the CNG buses and 38% from the diesel buses were removed by heating the emissions to 300 degrees C.

Applications of low-cost sensing technologies for air quality monitoring and exposure assessment: How far have they gone?

Publisher: Elsevier BV

Date: 07-2018

DOI: 10.1016/J.ENVINT.2018.04.018

Hydrothermal liquefaction of bagasse using ethanol and black liquor as solvents

Publisher: Wiley

Date: 10-09-2015

DOI: 10.1002/BBB.1578

Respiratory health effects of diesel particulate matter

Publisher: Wiley

Date: 24-01-2012

DOI: 10.1111/J.1440-1843.2011.02109.X

Abstract: Particulate matter (PM) emissions involve a complex mixture of solid and liquid particles suspended in a gas, where it is noted that PM emissions from diesel engines are a major contributor to the ambient air pollution problem. While epidemiological studies have shown a link between increased ambient PM emissions and respiratory morbidity and mortality, studies of this design are not able to identify the PM constituents responsible for driving adverse respiratory health effects. This review explores in detail the physico-chemical properties of diesel PM (DPM) and identifies the constituents of this pollution source that are responsible for the development of respiratory disease. In particular, this review shows that the DPM surface area and adsorbed organic compounds play a significant role in manifesting chemical and cellular processes that if sustained can lead to the development of adverse respiratory health effects. The mechanisms of injury involved included inflammation, innate and acquired immunity, and oxidative stress. Understanding the mechanisms of lung injury from DPM will enhance efforts to protect at-risk in iduals from the harmful respiratory effects of air pollutants.

Comparative evaluation of the effect of sweet orange oil-diesel blend on performance and emissions of a multi-cylinder compression ignition engine

Publisher: Author(s)

Date: 2017

DOI: 10.1063/1.4984636

The effect of diesel emission exposure on primary human bronchial epithelial cells from a COPD cohort: N-acetylcysteine as a potential protective intervention.

Publisher: Elsevier BV

Date: 03-2018

DOI: 10.1016/J.ENVRES.2018.12.035

Abstract: Chronic obstructive pulmonary disease (COPD) will be the third leading cause of death world-wide by 2020. Prolonged exposure to particulate matter is associated with COPD progression and mortality. Diesel emissions are a major contributor to particulate matter pollution. In this study we test a therapeutic antioxidant, N-acetylcysteine (NAC), for its ability to protect bronchial epithelial cells (pHBECs) from patients with COPD from adverse effects of diesel emission exposure. pHBECs from patients with or without COPD were cultured at air-liquid interface (ALI). Cells were exposed to diesel emissions for 30 min with or without 3-h post-exposure treatment with 5 mM N-acetylcysteine (NAC). Filtered laboratory air was tested as a negative control. Cell responses (cell viability, inflammation and oxidative stress) and gene expression profiles for intracellular and immune signaling were assessed. Diesel emissions exposure increased IL-8 secretion and production, antioxidant production, and cytochrome P450 1a1 (CYP1a1) mRNA expression and suppressed superoxide dismutase-1 (SOD1) mRNA expression in bronchial epithelial cells from COPD patients. Treatment with N-acetyl cysteine attenuated the suppression of SOD1. Nanostring gene expression profiling of the filtered air controls showed COPD epithelial cells have increased expression of MHC class II and an interferon signaling profile. This study indicates that bronchial epithelial cells from COPD patients may be vulnerable to diesel emission exposure due to reduced antioxidant capacity, and elevated CYP1a1 mRNA expression. NAC did not appear to offer protection. Future research will be needed to explore other means of recovering oxidant capacity in COPD airways.

Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling

Publisher: Copernicus GmbH

Date: 05-10-2017

DOI: 10.5194/ACP-17-11707-2017

Abstract: Abstract. We have tested the ability of a high-resolution chemical transport model (CTM) to reproduce biomass burning (BB) plume strikes and ozone (O3) enhancements observed at Cape Grim in Tasmania, Australia, from the Robbins Island fire. The CTM has also been used to explore the contribution of near-field BB emissions and background sources to O3 observations under conditions of complex meteorology. Using atmospheric observations, we have tested model sensitivity to meteorology, BB emission factors (EFs) corresponding to low, medium, and high modified combustion efficiency (MCE), and spatial variability. The use of two different meteorological models (TAPM–CTM and CCAM–CTM) varied the first (BB1) plume strike time by up to 15 h and the duration of impact between 12 and 36 h, and it varied the second (BB2) plume duration between 50 and 57 h. Meteorology also had a large impact on simulated O3, with one model (TAPM–CTM) simulating four periods of O3 enhancement, while the other model (CCAM) simulating only one period. Varying the BB EFs, which in turn varied the non-methane organic compound (NMOC) ∕ oxides of nitrogen (NOx) ratio, had a strongly non-linear impact on simulated O3 concentration, with either destruction or production of O3 predicted in different simulations. As shown in previous work (Lawson et al., 2015), minor rainfall events have the potential to significantly alter EF due to changes in combustion processes. Models that assume fixed EF for O3 precursor species in an environment with temporally or spatially variable EF may be unable to simulate the behaviour of important species such as O3. TAPM–CTM is used to further explore the contribution of the Robbins Island fire to the observed O3 enhancements during BB1 and BB2. Overall, TAPM–CTM suggests that the dominant source of O3 observed at Cape Grim was aged urban air (age = 2 days), with a contribution of O3 formed from local BB emissions. This work shows the importance of assessing model sensitivity to meteorology and EF and the large impact these variables can have in particular on simulated destruction or production of O3 in regional atmospheric chemistry simulations. This work also shows the importance of using models to elucidate the contribution from different sources to atmospheric composition, where this is difficult using observations alone.

Determination of average emission factors for vehicles on a busy road

Publisher: Elsevier BV

Date: 02-2003

DOI: 10.1016/S1352-2310(02)00923-8

Impact of COVID-19 on the imaging diagnosis of cardiac disease in Europe

Publisher: BMJ

Date: 08-2021

DOI: 10.1136/OPENHRT-2021-001681

Abstract: We aimed to explore the impact of the COVID-19 pandemic on cardiac diagnostic testing and practice and to assess its impact in different regions in Europe. The online survey organised by the International Atomic Energy Agency Division of Human Health collected information on changes in cardiac imaging procedural volumes between March 2019 and March/April 2020. Data were collected from 909 centres in 108 countries. Centres in Northern and Southern Europe were more likely to cancel all outpatient activities compared with Western and Eastern Europe. There was a greater reduction in total procedure volumes in Europe compared with the rest of the world in March 2020 (45% vs 41%, p=0.003), with a more marked reduction in Southern Europe (58%), but by April 2020 this was similar in Europe and the rest of the world (69% vs 63%, p=0.261). Regional variations were apparent between imaging modalities, but the largest reductions were in Southern Europe for nearly all modalities. In March 2020, location in Southern Europe was the only independent predictor of the reduction in procedure volume. However, in April 2020, lower gross domestic product and higher COVID-19 deaths were the only independent predictors. The first wave of the COVID-19 pandemic had a significant impact on care of patients with cardiac disease, with substantial regional variations in Europe. This has potential long-term implications for patients and plans are required to enable the diagnosis of non-COVID-19 conditions during the ongoing pandemic.

An experimental investigation of diesel soot thermal-induced oxidation based on the chemical structure evolution

Publisher: Elsevier BV

Date: 03-2022

DOI: 10.1016/J.CARBON.2021.11.068

Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania, 41° S

Publisher: Copernicus GmbH

Date: 07-2015

DOI: 10.5194/ACPD-15-17599-2015

Abstract: Abstract. Biomass burning (BB) plumes were measured at the Cape Grim Baseline Air Pollution Station during the 2006 Precursors to Particles c aign, when emissions from a fire on nearby Robbins Island impacted the station. Measurements made included non methane organic compounds (NMOCs) (PTR-MS), particle number size distribution, condensation nuclei (CN) 3 nm, black carbon (BC) concentration, cloud condensation nuclei (CCN) number, ozone (O3), methane (CH4), carbon monixide (CO), hydrogen (H2), carbon dioxide (CO2), nitrous oxide (N2O), halocarbons and meteorology. During the first plume strike event (BB1), a four hour enhancement of CO (max ~ 2100 ppb), BC (~ 1400 ng m−3) and particles 3 nm (~ 13 000 cm−3) with dominant particle mode of 120 nm were observed overnight. Dilution of the plume resulted in a drop in the dominant particle mode to 50 nm, and then growth to 80 nm over 5 h. This was accompanied by an increase in O3, suggesting that photochemical processing of air and condensation of low volatility oxidation products may be driving particle growth. The ability of particles 80 nm (CN80) to act as CCN at 0.5 % supersaturation was investigated. The ΔCCN / ΔCN80 ratio was lowest during the fresh BB plume (56 %), higher during the particle growth event (77 %) and higher still (104 %) in background marine air. Particle size distributions indicate that changes to particle chemical composition, rather than particle size, are driving these changes. Hourly average CCN during both BB events were between 2000–5000 CCN cm−3, which were enhanced above typical background levels by a factor of 6–34, highlighting the dramatic impact BB plumes can have on CCN number in clean marine regions. During the 29 h of the second plume strike event (BB2) CO, BC and a range of NMOCs including acetonitrile and hydrogen cyanide (HCN) were clearly enhanced and some enhancements in O3 were observed (ΔO3 / ΔCO 0.001–0.074). A shortlived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2–4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meterological events on BB emissions. Emission factors (EF) were derived for a range of trace gases, some never before reported for Australian conditions, (including hydrogen, phenol and toluene) using a calculated ER to CO and a published CO EF. The EF derived for most species are comparable to other temperate Australian studies but lower than Northern Hemisphere temperate studies. This work demonstrates the substantial impact that BB plumes have on the composition of marine air, and the significant changes that can occur as the plume is diluted and interacts with other emission sources. We also provide new trace gas and particle EF for temperate southern Australia.

Measuring the regional availability of biomass for biofuels and the potential for microalgae

Publisher: Elsevier BV

Date: 09-2015

DOI: 10.1016/J.RSER.2015.04.084

Characterization of aerosols over the Great Barrier Reef: The influence of transported continental sources

Publisher: Elsevier BV

Date: 11-2019

DOI: 10.1016/J.SCITOTENV.2019.07.007

Abstract: The rapid environmental changes in Australia prompt a more thorough investigation of the influence of transportation, local emissions, and optical-chemical properties on aerosol production across the region. A month-long intensive measurement c aign was conducted during spring 2016 at Mission Beach, a remote coastal site west of the Great Barrier Reef (GBR) on the north-east coast of Australia. One aerosol pollution episode was investigated in early October. This event was governed by meteorological conditions and characterized by the increase in black carbon (BC) mass concentration (averaged value of 0.35 ± 0.20 μg m

Quantification of Particle-Bound Organic Radicals in Secondary Organic Aerosol

Publisher: American Chemical Society (ACS)

Date: 10-05-2019

DOI: 10.1021/ACS.EST.9B00825

Abstract: The chemical composition and evolution of secondary organic aerosol (SOA) in the atmosphere represents one of the largest uncertainties in our current understanding of air quality. Despite vast research, the toxicological mechanisms relating to adverse human health effects upon exposure to particulate matter are still poorly understood. Particle-bound reactive oxygen species (ROS) may substantially contribute to observed health effects by influencing aerosol oxidative potential (OP). The role of radicals in both the formation and aging of aerosol, as well as their contribution to aerosol OP, remains highly uncertain. The profluorescent spin trap BPEAnit (9,10-bis(phenylethynyl)anthracenenitroxide), previously utilized to study combustion-generated aerosol, has been applied to provide the first estimate of particle-bound radical concentrations in SOA. We demonstrate that SOA from different atmospherically important VOC precursors have different particle-bound radical concentrations, estimated for the ozonolysis of α-pinene (0.020 ± 0.0050 nmol/μg), limonene (0.0059 ± 0.0010 nmol/μg), and β-caryophyllene (0.0025 ± 0.00080 nmol/μg), highlighting the potential importance of OH-initiated formation of particle-bound organic radicals. Additionally, the lifetime of particle-bound radical species in α-pinene SOA was estimated, and a pseudo-first-order rate constant of k = 7.3 ± 1.7 × 10

Supplementary material to "Characterization of the Particle Emission from Ships Operating at Sea Using Unmanned Aerial Vehicles"

Publisher: Copernicus GmbH

Date: 26-06-2017

DOI: 10.5194/AMT-2017-146-SUPPLEMENT

A photoacoustic investigation of transport properties and thermal diffusivity of InSb single crystals

Publisher: Elsevier BV

Date: 09-1996

DOI: 10.1016/0026-2692(95)00025-9

An aerosol comparison of various sites on different sides of the world

Publisher: Elsevier BV

Date: 09-1999

DOI: 10.1016/S0021-8502(99)80122-0

Physicochemical characterization of porcine respiratory aerosol and considerations for future aerovirology

Publisher: Oxford University Press (OUP)

Date: 03-2023

DOI: 10.1093/PNASNEXUS/PGAD087

Abstract: Understanding the mechanisms which inactivate airborne viruses is a current challenge. The composition of human respiratory aerosol is poorly understood and needs to be adequately investigated for use in aerovirology studies. Here, the physicochemical properties of porcine respiratory fluid (PRF) from the trachea and lungs were investigated both in bulk solutions and in aerosols. The mass ratio of Na:K in PRF compared with cell culture media (Dulbecco's Modified Eagle Medium, DMEM), which is frequently used in aerovirology studies, was significantly lower (∼2:1 vs ∼16:1). PRF contained significantly more potassium and protein than DMEM. PRF aerosols of all s les were similarly hygroscopic to human respiratory aerosol. PRF particles could nucleate with spatially separated crystals, indicating that the protein matrix was sufficiently viscous to prevent the complete coalescence of aqueous salts prior to efflorescence. The effects of these differences in compositions on the viability of viruses are currently not well understood. The virus suspensions in aerovirology studies need to be reconsidered to adequately reflect a real-world expiration scenario.

Oxidative Potential of Logwood and Pellet Burning Particles Assessed by a Novel Profluorescent Nitroxide Probe

Publisher: American Chemical Society (ACS)

Date: 04-08-2010

DOI: 10.1021/ES100963Y

Abstract: This study reports the potential toxicological impact of particles produced during biomass combustion by an automatic pellet boiler and a traditional logwood stove under various combustion conditions using a novel profluorescent nitroxide probe, BPEAnit. This probe is weakly fluorescent but yields strong fluorescence emission upon radical trapping or redox activity. S les were collected by bubbling aerosol through an impinger containing BPEAnit solution, followed by fluorescence measurement. The fluorescence of BPEAnit was measured for particles produced during various combustion phases: at the beginning of burning (cold start), stable combustion after refilling with the fuel (warm start), and poor burning conditions. For particles produced by the logwood stove under cold-start conditions, significantly higher amounts of reactive species per unit of particulate mass were observed compared to emissions produced during a warm start. In addition, s ling of logwood burning emissions after passing through a thermodenuder at 250 degrees C resulted in an 80-100% reduction of the fluorescence signal of the BPEAnit probe, indicating that the majority of reactive species were semivolatile. Moreover, the amount of reactive species showed a strong correlation with the amount of particulate organic material. This indicates the importance of semivolatile organics in particle-related toxicity. Particle emissions from the pellet boiler, although of similar mass concentration, were not observed to lead to an increase in fluorescence signal during any of the combustion phases.

Observation of new particle formation in subtropical urban environment

Publisher: Copernicus GmbH

Date: 10-2010

DOI: 10.5194/ACPD-10-22623-2010

Abstract: Abstract. The aim of this study was to characterise the new particle formation events in subtropical urban environment Southern Hemisphere. The study measured the number concentration of particles and its size distribution in Brisbane, Australia during 2009. The variation of particle number concentration and nucleation burst events were studied and the particle growth rate was characterised which was first reported in urban environment of Australia. The annual average NUFP, NAitken and Nnuc were 9.3×103, 3.7×103 and 5.6×103 cm−3, respectively. Weak seasonal variation in number concentration was observed. Local vehicle emission was major contributor of the pollution observed in the morning which was dominated by the Aitken mode particles, while particle formed by secondary formation process was contributed to the particle number concentration in the afternoon. 65 nucleation burst events were identified during the study period. Nucleation burst events were classified into two groups with and without particle growth after the burst of nucleation mode particles observed. Average particle growth rate of the nucleation events was 4.6 nm hr−1 (ranged from 1.79–7.78 nm hr−1). Case studies of the nucleation burst events were characterised including i) the nucleation burst with particle growth which was associated with the particle precursor emitted from local vehicle emission, ii) the nucleation burst without particle growth which was due to the transport of industrial emissions from the coast to Brisbane city, and iii) interplay between the above two cases which demonstrated the impact of the vehicle and industrial emissions on the variation of particle number concentration and its size distribution during the same day.

Supplementary material to "Composition, size and cloud condensation nuclei activity of biomass burning aerosol from north Australian savannah fires"

Publisher: Copernicus GmbH

Date: 07-10-2016

DOI: 10.5194/ACP-2016-867-SUPPLEMENT

Experimental analysis of the morphology and nanostructure of soot particles for butanol/diesel blends at different engine operating modes

Publisher: American Chemical Society (ACS)

Date: 15-05-2019

DOI: 10.1021/ACS.ENERGYFUELS.9B00368

Application of Multicriteria Decision Making Methods to Compression Ignition Engine Efficiency and Gaseous, Particulate, and Greenhouse Gas Emissions

Publisher: American Chemical Society (ACS)

Date: 08-02-2013

DOI: 10.1021/ES3035208

Abstract: Compression ignition (CI) engine design is subject to many constraints, which present a multicriteria optimization problem that the engine researcher must solve. In particular, the modern CI engine must not only be efficient but must also deliver low gaseous, particulate, and life cycle greenhouse gas emissions so that its impact on urban air quality, human health, and global warming is minimized. Consequently, this study undertakes a multicriteria analysis, which seeks to identify alternative fuels, injection technologies, and combustion strategies that could potentially satisfy these CI engine design constraints. Three data sets are analyzed with the Preference Ranking Organization Method for Enrichment Evaluations and Geometrical Analysis for Interactive Aid (PROMETHEE-GAIA) algorithm to explore the impact of (1) an ethanol fumigation system, (2) alternative fuels (20% biodiesel and synthetic diesel) and alternative injection technologies (mechanical direct injection and common rail injection), and (3) various biodiesel fuels made from 3 feedstocks (i.e., soy, tallow, and canola) tested at several blend percentages (20-100%) on the resulting emissions and efficiency profile of the various test engines. The results show that moderate ethanol substitutions (~20% by energy) at moderate load, high percentage soy blends (60-100%), and alternative fuels (biodiesel and synthetic diesel) provide an efficiency and emissions profile that yields the most "preferred" solutions to this multicriteria engine design problem. Further research is, however, required to reduce reactive oxygen species (ROS) emissions with alternative fuels and to deliver technologies that do not significantly reduce the median diameter of particle emissions.

Erratum to “A comparative study of the elemental composition of the exhaust emissions of cars powered by liquefied petroleum gas and unleaded petrol” [Atmospheric Environment 40 (2006) 3111–3122]

Publisher: Elsevier BV

Date: 12-2006

DOI: 10.1016/J.ATMOSENV.2006.09.007

The ambient aerosol characterization during the prescribed bushfire season in Brisbane 2013

Publisher: Elsevier BV

Date: 08-2016

DOI: 10.1016/J.SCITOTENV.2016.04.036

Abstract: Prescribed burnings are conducted in Queensland each year from August until November aiming to decrease the impact of bushfire hazards and maintain the health of vegetation. This study reports chemical characteristics of the ambient aerosol, with a focus on source apportionment of the organic aerosol (OA) fraction, during the prescribed biomass burning (BB) season in Brisbane 2013. All measurements were conducted within the International Laboratory for Air Quality and Health (ILAQH) located in Brisbane's Central Business District. Chemical composition, degree of ageing and the influence of BB emission on the air quality of central Brisbane were characterized using a compact Time of Flight Aerosol Mass Spectrometer (cToF-AMS). AMS loadings were dominated by OA (64%), followed by, sulfate (17%), ammonium (14%) and nitrates (5%). Source apportionment was applied on the AMS OA mass spectra via the multilinear engine solver (ME-2) implementation within the recently developed Source Finder (SoFi) interface. Six factors were extracted including hydrocarbon-like OA (HOA), cooking-related OA (COA), biomass burning OA (BBOA), low-volatility oxygenated OA (LV-OOA), semivolatile oxygenated OA (SV-OOA), and nitrogen-enriched OA (NOA). The aerosol fraction that was attributed to BB factor was 9%, on average over the s ling period. The high proportion of oxygenated OA (72%), typically representing aged emissions, could possess a fraction of oxygenated species transfored from BB components on their way to the s ling site.

Study of performance, combustion and emission characteristics of a common rail diesel engine with tea tree oil-diglyme blends

Publisher: Elsevier BV

Date: 08-2019

DOI: 10.1016/J.ENERGY.2019.05.070

Comprehensive aerosol and gas data set from the Sydney Particle Study

Publisher: Copernicus GmbH

Date: 13-05-2019

DOI: 10.5194/ESSD-2019-56

Abstract: Abstract. The Sydney Particle Study involved the comprehensive measurement of meteorology, particles and gases at a location in western Sydney during February/March 2011 and April/May 2012. The aim of this study was to increase scientific knowledge of the processes leading to particle formation and transformations in Sydney. In this paper we describe the methods used to collect and analyse particle and gaseous s les, as well as the methods employed for the continuous measurement of particle concentrations, particle microphysical properties and gaseous concentrations. This paper also provides a description of the data collected and is a meta data record for the data sets published in Keywood et al. (2016a) 0.4225/08/57903B83D6A5D and Keywood et al. (2016b) 0.4225/08/5791B5528BD63.

The influence of oxygenated fuels on transient and steady-state engine emissions

Publisher: Elsevier BV

Date: 02-2017

DOI: 10.1016/J.ENERGY.2017.01.058

New Methods of Determination of Average Particle Emission Factors for Two Groups of Vehicles on a Busy Road

Publisher: Elsevier BV

Date: 05-2004

DOI: 10.1016/J.ATMOSENV.2004.02.015

Elevated levels of glyoxal and methylglyoxal at a remote mountain site in southern China: Prompt in-situ formation combined with strong regional transport

Publisher: Elsevier BV

Date: 07-2019

DOI: 10.1016/J.SCITOTENV.2019.04.020

Abstract: The dicarbonyls glyoxal (Gly) and methylglyoxal (Mgly) are key tracers for the oxidation of volatile organic compounds (VOCs) in the atmosphere, but their atmospheric chemistry in remote forest environments is not well understood. A study was carried out during Jul. 31-Nov. 5 of 2016 at the summit of Mt. Tianjing (1690 m.a.s.l.), a remote mountaintop site in southern China, to measure the levels of Gly and Mgly and explore their sources and fate. During the study period, the average mixing ratios of Gly and Mgly were 509 ± 31 pptv and 340 ± 32 pptv, respectively, with the Gly/Mgly ratios averaging 1.8 ± 0.2. Both the dicarbonyl concentrations and the Gly/Mgly ratios were significantly higher than those observed in other background sites. Production yield calculations and meteorological data analysis indicate that high levels of Gly and Mgly observed at the study site were largely a combined result of rapid in-situ formation and regional transport by prevailing winds. On average, in-situ formation from precursors is estimated to account for 67% of the observed Mgly and about 9% of the observed Gly. There were significant changes in Gly and Mgly mixing ratios among different time periods when air masses from different source regions dominated, indicating contribution of regional transport to the observed dicarbonyl mixing ratios at the study site. Biogenic emissions in eastern China and anthropogenic emissions in the Pearl River Delta region were the two main sources responsible for the dicarbonyls observed at the site during most of the s ling period, but large-scale biomass burning in central China was also important in the late autumn, as supported by a backward trajectory analysis of fire spot data and the identification of biomass burning tracers. This study provides insights into the background atmospheric chemistry and the impact of biogenic and anthropogenic sources on the dicarbonyls speciation.

A multiscale modeling method incorporating spatial coupling and temporal coupling into transient simulations of the human airways

Publisher: Wiley

Date: 09-06-2021

DOI: 10.1002/FLD.5015

Abstract: In this article, a novel multiscale modeling method is proposed for transient computational fluid dynamics (CFD) simulations of the human airways. The developed method is the first attempt to incorporate spatial coupling and temporal coupling into transient human airway simulations, aiming to improve the flexibility and the efficiency of these simulations. In this method, domain decomposition was used to separate the complex airway model into different scaled domains. Each scaled domain could adopt a suitable mesh and timestep, as necessary: the coarse mesh and large timestep were employed in the macro regions to reduce the computational cost, while the fine mesh and small timestep were used in micro regions to maintain the simulation accuracy. The radial point interpolation method was used to couple data between the coarse mesh and the fine mesh. The continuous micro solution–intermittent temporal coupling method was applied to bridge different timesteps. The developed method was benchmarked using a well‐studied four‐generation symmetric airway model under realistic normal breath conditions. The accuracy and efficiency of the method were verified separately in the inhalation phase and the exhalation phase. Similar airflow behavior to previous studies was observed from the multiscale airway model. The developed multiscale method has the potential to improve the flexibility and efficiency of transient human airway simulations without sacrificing accuracy.

JEM Spotlight: Environmental monitoring of airborne nanoparticles

Publisher: Royal Society of Chemistry (RSC)

Date: 2009

DOI: 10.1039/B912589M

Abstract: The aim of this work was to review the existing instrumental methods to monitor airborne nanoparticles in different types of indoor and outdoor environments in order to detect their presence and to characterise their properties. Firstly the terminology and definitions used in this field are discussed, which is followed by a review of the methods to measure particle physical characteristics including number, concentration, size distribution and surface area. An extensive discussion is provided on the direct methods for particle elemental composition measurements, as well as on indirect methods providing information on particle volatility and solubility, and thus in turn on volatile and semivolatile compounds of which the particle is composed. A brief summary of broader considerations related to nanoparticle monitoring in different environments concludes the paper.

Atmospheric concentrations and sources of black carbon over tropical Australian waters

Publisher: Elsevier BV

Date: 2023

DOI: 10.1016/J.SCITOTENV.2022.159143

Abstract: Black carbon (BC) aerosols significantly contribute to radiative budgets globally, however their actual contributions remain poorly constrained in many under-s led ocean regions. The tropical waters north of Australia are a part of the Indo-Pacific warm pool, regarded as a heat engine of global climate, and are in proximity to large terrestrial sources of BC aerosols such as fossil fuel emissions, and biomass burning emissions from northern Australia. Despite this, measurements of marine aerosols, especially BC remain elusive, leading to large uncertainties and discrepancies in current chemistry-climate models for this region. Here, we report the first comprehensive measurements of aerosol properties collected over the tropical warm pool in Australian waters during a voyage in late 2019. The non-marine related aerosol emissions observed in the Arafura Sea region were more intense than in the Timor Sea marine region, as the Arafura Sea was subject to greater continental outflows. The median equivalent BC (eBC) concentration in the Arafura Sea (0.66 μg m

Physicochemical Characterization of Particulate Emissions from a Compression Ignition Engine Employing Two Injection Technologies and Three Fuels

Publisher: American Chemical Society (ACS)

Date: 31-05-2011

DOI: 10.1021/ES200388F

Abstract: Alternative fuels and injection technologies are a necessary component of particulate emission reduction strategies for compression ignition engines. Consequently, this study undertakes a physicochemical characterization of diesel particulate matter (DPM) for engines equipped with alternative injection technologies (direct injection and common rail) and alternative fuels (ultra low sulfur diesel, a 20% biodiesel blend, and a synthetic diesel). Particle physical properties were addressed by measuring particle number size distributions, and particle chemical properties were addressed by measuring polycyclic aromatic hydrocarbons (PAHs) and reactive oxygen species (ROS). Particle volatility was determined by passing the polydisperse size distribution through a thermodenuder set to 300 °C. The results from this study, conducted over a four point test cycle, showed that both fuel type and injection technology have an impact on particle emissions, but injection technology was the more important factor. Significant particle number emission (54%-84%) reductions were achieved at half load operation (1% increase-43% decrease at full load) with the common rail injection system however, the particles had a significantly higher PAH fraction (by a factor of 2 to 4) and ROS concentrations (by a factor of 6 to 16) both expressed on a test-cycle averaged basis. The results of this study have significant implications for the health effects of DPM emissions from both direct injection and common rail engines utilizing various alternative fuels.

Investigation of a modified Sinclair–La Mer aerosol generator in the submicrometer range

Publisher: Elsevier BV

Date: 08-1998

DOI: 10.1016/S0021-8502(97)10024-6

Determining the link between hygroscopicity and composition for semi-volatile aerosol species

Publisher: Copernicus GmbH

Date: 30-01-2018

DOI: 10.5194/AMT-2018-17

Abstract: Abstract. Internally and externally mixed aerosols present significant challenges in assessing the hygroscopicity of each aerosol component. This study presents a new s ling technique which uses differences in volatility to separate mixtures and directly examine their respective composition and hygroscopic contribution. A shared thermodenuder and unheated bypass line are continuously cycled between an aerosol mass spectrometer and a volatility and hygroscopicity tandem differential mobility analyser, allowing real-time comparative analysis of heated and unheated aerosol properties. Measurements have been taken of both chamber-generated secondary organic aerosol and coastal marine aerosol at Cape Grim, Australia, to investigate system performance under erse conditions. Despite rapidly changing aerosol properties and the need to restrict analysis to a narrow size-range, the former experiment separated the hygroscopic influences of ammonium sulfate and two distinct organic components with similar oxygen to carbon ratios but different volatilities. Analysis of the marine aerosol revealed an external mixture of non-sea salt sulfates and sea spray aerosol, both of which likely shared similar volatile fractions composed of sulfuric acid and a non-hygroscopic organic component.

Deposition rates of fungal spores in indoor environments, factors effecting them and comparison with non-biological aerosols

Publisher: Elsevier BV

Date: 09-2008

DOI: 10.1016/J.ATMOSENV.2008.05.059

Multivariate analysis of performance and emission parameters in a diesel engine using biodiesel and oxygenated additive

Publisher: Elsevier BV

Date: 12-2019

DOI: 10.1016/J.ENCONMAN.2019.112183

Particle emissions from compressed natural gas engines

Publisher: Elsevier BV

Date: 04-2000

DOI: 10.1016/S0021-8502(99)00530-3

Synthesis and evaluation of catalytic activity of NiFe2O4 nanoparticles in a diesel engine: An experimental investigation and Multi-Criteria Decision Making approach

Publisher: Elsevier BV

Date: 09-2022

DOI: 10.1016/J.JCLEPRO.2022.132818

Supplementary material to "An instrument for the rapid quantification of PM oxidative potential: the Particle Into Nitroxide Quencher (PINQ)"

Publisher: Copernicus GmbH

Date: 05-11-2018

DOI: 10.5194/AMT-2018-333-SUPPLEMENT

Supplementary material to "Sea spray aerosol organic enrichment, water uptake and surface tension effects"

Publisher: Copernicus GmbH

Date: 19-09-2019

DOI: 10.5194/ACP-2019-797-SUPPLEMENT

Influence of Diesel Fuel Sulfur on Nanoparticle Emissions from City Buses

Publisher: American Chemical Society (ACS)

Date: 20-01-2006

DOI: 10.1021/ES050094I

Abstract: Particle emissions from twelve buses, operating alternately on low sulfur (LS 500 ppm) and ultralow sulfur (ULS 50 ppm) diesel fuel, were monitored. The buses were 1-19 years old and had no after-treatment devices fitted. Measurements were carried out at four steady-state operational modes on a chassis dynamometer using a mini dilution tunnel (PM mass measurement) and a Dekati ejector diluter as a secondary diluter (SMPS particle number). The mean particle number emission rate (s(-1)) of the buses, in the size range 8-400 nm, using ULS diesel was 31% to 59% lower than the rate using LS diesel in all four modes. The fractional reduction was highest in the newest buses and decreased with mileage upto about 500,000 km, after which no further decrease was apparent. However, the mean total suspended particle (TSP) mass emission rate did not show a systematic difference between the two fuel types. When the fuel was changed from LS to ULS diesel, the reduction in particle number was mainly in the nanoparticle size range. Over all operational modes, 58% of the particles were smaller than 50 nm with LS fuel as opposed to just 45% with ULS fuel, suggesting that sulfur in diesel fuel was playing a major role in the formation of nanoparticles. The greatest influence of the fuel sulfur content was observed at the highest engine load, where 74% of the particles were smaller than 50 nm with LS diesel compared to 43% with ULS diesel.

Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols

Publisher: Copernicus GmbH

Date: 10-07-2020

DOI: 10.5194/ACP-20-8047-2020

Abstract: Abstract. Cloud–radiation interactions over the Southern Ocean are not well constrained in climate models, in part due to uncertainties in the sources, concentrations, and cloud-forming potential of aerosol in this region. To date, most studies in this region have reported measurements from fixed terrestrial stations or a limited set of instrumentation and often present findings as broad seasonal or latitudinal trends. Here, we present an extensive set of aerosol and meteorological observations obtained during an austral summer cruise across the full width of the Southern Ocean south of Australia. Three episodes of continental-influenced air masses were identified, including an apparent transition between the Ferrel atmospheric cell and the polar cell at approximately 64∘ S, and accompanied by the highest median cloud condensation nuclei (CCN) concentrations, at 252 cm−3. During the other two episodes, synoptic-scale weather patterns erted air masses across distances greater than 1000 km from the Australian and Antarctic coastlines, respectively, indicating that a large proportion of the Southern Ocean may be periodically influenced by continental air masses. In all three cases, a highly cloud-active accumulation mode dominated the size distribution, with up to 93 % of the total number concentration activating as CCN. Frequent cyclonic weather conditions were observed at high latitudes and the associated strong wind speeds led to predictions of high concentrations of sea spray aerosol. However, these modelled concentrations were not achieved due to increased aerosol scavenging rates from precipitation and convective transport into the free troposphere, which decoupled the air mass from the sea spray flux at the ocean surface. CCN concentrations were more strongly impacted by high concentrations of large-diameter Aitken mode aerosol in air masses which passed over regions of elevated marine biological productivity, potentially contributing up to 56 % of the cloud condensation nuclei concentration. Weather systems were vital for aerosol growth in biologically influenced air masses and in their absence ultrafine aerosol diameters were less than 30 nm. These results demonstrate that air mass meteorological history must be considered when modelling sea spray concentrations and highlight the potential importance of sub-grid-scale variability when modelling atmospheric conditions in the remote Southern Ocean.

Observation of new particle formation in subtropical urban environment

Publisher: Copernicus GmbH

Date: 27-04-2011

DOI: 10.5194/ACP-11-3823-2011

Abstract: Abstract. The aim of this study was to characterise the new particle formation events in a subtropical urban environment in the Southern Hemisphere. The study measured the number concentration of particles and its size distribution in Brisbane, Australia during 2009. The variation of particle number concentration and nucleation burst events were characterised as well as the particle growth rate which was first reported in urban environment of Australia. The annual average NUFP, NAitken and NNuc were 9.3×103, 3.7×103 and 5.6×103 cm−3, respectively. Weak seasonal variation in number concentration was observed. Local traffic exhaust emissions were a major contributor of the pollution (NUFP) observed in morning which was dominated by the Aitken mode particles, while particles formed by secondary formation processes contributed to the particle number concentration during afternoon. Overall, 65 nucleation burst events were identified during the study period. Nucleation burst events were classified into two groups, with and without particles growth after the burst of nucleation mode particles observed. The average particle growth rate of the nucleation events was 4.6 nm h−1 (ranged from 1.79–7.78 nm h−1). Case studies of the nucleation burst events were characterised including (i) the nucleation burst with particle growth which is associated with the particle precursor emitted from local traffic exhaust emission, (ii) the nucleation burst without particle growth which is due to the transport of industrial emissions from the coast to Brisbane city or other possible sources with unfavourable conditions which suppressed particle growth and (iii) interplay between the above two cases which demonstrated the impact of the vehicle and industrial emissions on the variation of particle number concentration and its size distribution during the same day.

Effect of face velocity and the nature of aerosol on the collection of submicrometer particles by electrostatic precipitator

Publisher: Hindawi Limited

Date: 06-2002

DOI: 10.1034/J.1600-0668.2002.09136.X

Abstract: Despite the electrostatic collection of aerosol particles as one of the most widely used air cleaning methods, there has not been sufficient amount of effort devoted to investigate its performance in the full range of operating conditions. This paper reports results of the tests of a two-stage electrostatic precipitator (ESP) conducted in the particle size range of 0.018-1.2 microns over a range of flow rates using NaCl and Environmental Tobacco Smoke (ETS) test aerosols. The total collection efficiency of the precipitator was found to increase with an increase in the count median diameter (CMD) of the particles, to have polynomial dependence on flow rate and no significant dependence on the type of test aerosol. The fractional efficiency of the precipitator was found to be dependent on flow rate. However, the 'critical' particle size of about 1.2 microns was found to exist when the fractional collection efficiency becomes independent of flow rate. For submicrometer particles, the collection efficiency was found to be independent of particle size at flow rates below 560 l/s. A minimum in the efficiency was observed in the 0.1-0.45 micron particle size range and for particles smaller than about 0.02 micron.

Influence of biodiesel fuel composition on the morphology and microstructure of particles emitted from diesel engines

Publisher: Elsevier BV

Date: 08-2016

DOI: 10.1016/J.CARBON.2016.03.061

Investigation into chemistry of new particle formation and growth in subtropical urban environment

Publisher: Copernicus GmbH

Date: 11-11-2014

DOI: 10.5194/ACPD-14-27945-2014

Abstract: Abstract. The role of different chemical compounds, particularly organics, involved in the new particle formation (NPF) and its consequent growth are not fully understood. Therefore, this study was conducted to investigate the chemistry of aerosol particles during NPF events in an urban subtropical environment. Aerosol chemical composition was measured along with particle number size distribution (PNSD) and several other air quality parameters at five sites across an urban subtropical environment. An Aerodyne compact Time-of-Flight Aerosol Mass Spectrometer (c-TOF-AMS) and a TSI Scanning Mobility Particle Sizer (SMPS) measured aerosol chemical composition and PNSD, respectively. Five NPF events, with growth rates in the range 3.3–4.6 nm, were detected at two sites. The NPF events happened on relatively warmer days with lower humidity and higher solar radiation. Temporal percent fractions of nitrate, sulphate, ammonium and organics were modelled using the Generalised Additive Model (GAM), with a basis of penalised spline. Percent fractions of organics increased after the NPF events, while the mass fraction of ammonium and sulphate decreased. This uncovered the important role of organics in the growth of newly formed particles. Three organic markers, factors f43, f44 and f57, were calculated and the f44 vs. f43 trends were compared between nucleation and non-nucleation days. f44 vs. f43 followed a different pattern on nucleation days compared to non-nucleation days, whereby f43 decreased for vehicle emission generated particles, while both f44 and f43 decreased for NPF generated particles. It was found for the first time that vehicle generated and newly formed particles cluster in different locations on f44 vs. f43 plot and this finding can be used as a~tool for source apportionment of measured particles.

Application of the VH‐TDMA technique to coastal ambient aerosols

Publisher: American Geophysical Union (AGU)

Date: 08-2004

DOI: 10.1029/2004GL020126

The diurnal characteristics of PM-bound ROS and its influencing factors at urban ambient and roadside environments

Publisher: Elsevier BV

Date: 11-2020

DOI: 10.1016/J.ATMOSRES.2020.105039

The application of profluorescent nitroxides to detect reactive oxygen species derived from combustion-generated particulate matter: Cigarette smoke – A case study

Publisher: Elsevier BV

Date: 06-2010

DOI: 10.1016/J.ATMOSENV.2010.02.043

An instrument for the rapid quantification of PM-bound ROS: The Particle into Nitroxide Quencher (PINQ)

Publisher: Copernicus GmbH

Date: 16-04-2019

DOI: 10.5194/AMT-12-2387-2019

Abstract: Abstract. Reactive oxygen species (ROS) present on or generated by particulate matter (PM) have been implicated in PM-induced health effects. Methodologies to quantify ROS concentrations vary widely, both in detection and collection methods. However, there is currently an increasing emphasis on rapid collection and measurement due to observations of short half-life ROS. To address this problem, this paper details the design and characterization of a novel instrument for the measurement of PM-bound ROS named the Particle Into Nitroxide Quencher (PINQ). This instrument combines the 9,10-bis (phenylethynyl) anthracene-nitroxide (BPEAnit) ROS assay in conjunction with a purpose-built aerosol collection device, the insoluble aerosol collector (IAC). The IAC continuously collects PM regardless of size or chemistry directly into a liquid s le with a collection efficiency of 0.97 and a cut-off size of 20 nm. The s ling time resolution of the PINQ is 1 min, with a limit of detection (LOD) of 0.08 nmol m−3 in equivalent BPEAnit-Me concentration per volume of air. This high s le time resolution and sensitivity is achieved due to a combination of the highly concentrated IAC liquid s le, minimized liquid s le volume, and the rapid reaction and stability of the BPEAnit probe.

A parametric study on engine performance and emissions with neat diesel and diesel-butanol blends in the 13-Mode European Stationary Cycle

Publisher: Elsevier BV

Date: 09-2017

DOI: 10.1016/J.ENCONMAN.2017.06.001

The impact of chemical composition of oxygenated fuels on morphology and nanostructure of soot particles

Publisher: Elsevier BV

Date: 2020

DOI: 10.1016/J.FUEL.2019.116167

An experimental study of the role of biodiesel on the performance of diesel particulate filters

Publisher: Elsevier BV

Date: 07-2019

DOI: 10.1016/J.FUEL.2019.03.042

Performance Evaluation of the UVAPS in Measuring Biological Aerosols: Fluorescence Spectra from NAD(P)H Coenzymes and Riboflavin

Publisher: Informa UK Limited

Date: 04-2004

DOI: 10.1080/02786820490437505

Conflict, ethnicity and gender: A money-burning field experiment in Indonesia

Publisher: Elsevier BV

Date: 04-2019

DOI: 10.1016/J.ECONLET.2019.01.010

Physicochemical Characterization of Particulate Emissions from a Compression Ignition Engine: The Influence of Biodiesel Feedstock

Publisher: American Chemical Society (ACS)

Date: 15-11-2011

DOI: 10.1021/ES2018797

Abstract: This study undertook a physicochemical characterization of particle emissions from a single compression ignition engine operated at one test mode with 3 biodiesel fuels made from 3 different feedstocks (i.e., soy, tallow, and canola) at 4 different blend percentages (20%, 40%, 60%, and 80%) to gain insights into their particle-related health effects. Particle physical properties were inferred by measuring particle number size distributions both with and without heating within a thermodenuder (TD) and also by measuring particulate matter (PM) emission factors with an aerodynamic diameter less than 10 μm (PM(10)). The chemical properties of particulates were investigated by measuring particle and vapor phase Polycyclic Aromatic Hydrocarbons (PAHs) and also Reactive Oxygen Species (ROS) concentrations. The particle number size distributions showed strong dependency on feedstock and blend percentage with some fuel types showing increased particle number emissions, while others showed particle number reductions. In addition, the median particle diameter decreased as the blend percentage was increased. Particle and vapor phase PAHs were generally reduced with biodiesel, with the results being relatively independent of the blend percentage. The ROS concentrations increased monotonically with biodiesel blend percentage but did not exhibit strong feedstock variability. Furthermore, the ROS concentrations correlated quite well with the organic volume percentage of particles - a quantity which increased with increasing blend percentage. At higher blend percentages, the particle surface area was significantly reduced, but the particles were internally mixed with a greater organic volume percentage (containing ROS) which has implications for using surface area as a regulatory metric for diesel particulate matter (DPM) emissions.

Combustion characteristics of microalgae-based dioctyl phthalate biofuel during ambient, preheated and hot engine operation

Publisher: Elsevier BV

Date: 2023

DOI: 10.1016/J.FUEL.2022.125890

Effect of cold start on engine performance and emissions from diesel engines using IMO-Compliant distillate fuels

Publisher: Elsevier BV

Date: 12-2019

DOI: 10.1016/J.ENVPOL.2019.113260

Abstract: Emissions from ships at berth are small compared to the total ship emissions however, they are one of the main contributors to pollutants in the air of densely-populated areas, consequently heavily affecting public health. This is due to auxiliary marine engines being used to generate electric power and steam for heating and providing services. The present study has been conducted on an engine representative of a marine auxiliary, which was a heavy duty, six-cylinder, turbocharged and after-cooled engine with a high pressure common rail injection system. Engine performance and emission characterisations during cold start are the focus of this paper, since cold start is significantly influential. Three tested fuels were used, including the reference diesel and two IMO (International Maritime Organization) compliant spiked fuels. The research engine was operated at a constant speed and 25% load condition after 12 h cooled soak. Results show that during cold start, significant heat generated from combustion is used to heat the engine block, coolant and lubricant. During the first minute, compared to the second minute, emissions of particle number (PN), carbon monoxide (CO), particulate matter (PM), and nitrogen oxides (NO

Effects of enhanced fuel with Mg-doped Fe3O4 nanoparticles on combustion of a compression ignition engine

Publisher: Elsevier BV

Date: 05-2021

DOI: 10.1016/J.RSER.2021.110817

A Plume Capture Technique for the Remote Characterization of Aircraft Engine Emissions

Publisher: American Chemical Society (ACS)

Date: 20-05-2008

DOI: 10.1021/ES702581M

Abstract: A technique for capturing and analyzing plumes from unmodified aircraft or other combustion sources under real world conditions is described and applied to the task of characterizing plumes from commercial aircraft during the taxiing phase of the Landing/Take-Off (LTO) cycle. The method utilizes a Plume Capture and Analysis System (PCAS) mounted in a four-wheel drive vehicle which is positioned in the airfield 60 to 180 m downwind of aircraft operations. The approach offers low test turnaround times with the ability to complete careful measurements of particle and gaseous emission factors and sequentially scanned particle size distributions without distortion due to plume concentration fluctuations. These measurements can be performed for in idual aircraft movements at five minute intervals. A Plume Capture Device (PCD) collected s les of the naturally diluted plume in a 200 L conductive membrane conforming to a defined shape. S les from over 60 aircraft movements were collected and analyzed in situ for particulate and gaseous concentrations and for particle size distribution using a Scanning Particle Mobility Sizer (SMPS). Emission factors are derived for particle number, NO(x), and PM2.5 for a widely used commercial aircraft type, Boeing 737 airframes with predominantly CFM56 class engines, during taxiing. The practical advantages of the PCAS include the capacity to perform well targeted and controlled emission factor and size distribution measurements using instrumentation with varying response times within an airport facility, in close proximity to aircraft during their normal operations.

Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling

Publisher: Copernicus GmbH

Date: 05-12-2016

DOI: 10.5194/ACP-2016-932

Abstract: Abstract. We have tested the ability of high resolution chemical transport modelling (CTM) to reproduce biomass burning (BB) plume strikes observed at Cape Grim in Tasmania Australia from the Robbins Island fire. The model has also been used to explore the contribution of near-field BB emissions and background sources to ozone (O3) under conditions of complex meteorology. Using atmospheric observations, we have tested model sensitivity to meteorology, BB emission factors (EF) corresponding to low, medium and high modified combustion efficiency (MCE) and spatial variability. The use of two different meteorological models varied the first (BB1) plume strike time by up to 15 hours, and duration of impact between 12 and 36 hours, while the second plume strike (BB2) was simulated well using both meteorological models. Meteorology also had a large impact on simulated O3, with one model (TAPM-CTM) simulating 4 periods of O3 enhancement, while the other model (CCAM) simulating only one period. Varying the BB EFs which in turn varied the non methanic-organic compound (NMOC) / oxides of nitrogen (NOx) ratio had a strongly non-linear impact on O3 concentration, with either destruction or production of O3 predicted in different simulations. As shown in the previous work (Lawson et al., 2015), minor rainfall events have the potential to significantly alter EF due to changes in combustion processes. Models which assume fixed EF for O3 precursor species in an environment with temporally or spatially variable EF may be unable to simulate the behaviour of important species such as O3. TAPM-CTM is used to explore the contribution of the Robbins Island fire to the observed O3 enhancements during BB1 and BB2. Overall, the model suggests the dominant source of O3 observed at Cape Grim was aged urban air (age = 2 days), with a contribution of O3 formed from local BB emissions. The model indicates that in an area surrounding Cape Grim, between 25–43 % of O3 enhancement during BB1 was formed from BB emissions while the fire led to a net depletion in O3 during BB2. This work shows the importance of assessing model sensitivity to meteorology and EF, and the large impact these variables can have in particular on simulated destruction or production of O3. This work also demonstrates how a model can be used to elucidate the degree of contribution from different sources to atmospheric composition, where this is difficult using observations alone.

The role of non-thermal plasma technique in NOx treatment: A review

Publisher: Elsevier BV

Date: 12-2014

DOI: 10.1016/J.RSER.2014.07.194

Insights into the growth of newly formed particles in a subtropical urban environment

Publisher: Copernicus GmbH

Date: 07-12-2015

DOI: 10.5194/ACP-15-13475-2015

Abstract: Abstract. The role of different chemical compounds, particularly organics, involved in the new particle formation (NPF) and its consequent growth are not fully understood. Therefore, this study was conducted to investigate the chemical composition of aerosol particles during NPF events in an urban subtropical environment. Aerosol chemical composition was measured along with particle number size distribution (PNSD) and several other air quality parameters at five sites across an urban subtropical environment. An Aerodyne compact Time-of-Flight Aerosol Mass Spectrometer (c-ToF-AMS) and a TSI Scanning Mobility Particle Sizer (SMPS) measured aerosol chemical composition (particles above 50 nm in vacuum aerodynamic diameter) and PNSD (particles within 9–414 nm in mobility diameter), respectively. Five NPF events, with growth rates in the range 3.3–4.6 nm, were detected at two of the sites. The NPF events happened on relatively warmer days with lower condensation sink (CS). Temporal percent fractions of organics increased after the particles grew enough to have a significant contribution to particle volume, while the mass fraction of ammonium and sulfate decreased. This uncovered the important role of organics in the growth of newly formed particles. Three organic markers, factors f43, f44 and f57, were calculated and the f44 vs. f43 trends were compared between nucleation and non-nucleation days. K-means cluster analysis was performed on f44 vs. f43 data and it was found that they follow different patterns on nucleation days compared to non-nucleation days, whereby f43 decreased for vehicle-emission-generated particles, while both f44 and f43 decreased for NPF-generated particles. It was found for the first time that vehicle-generated and newly formed particles cluster in different locations on f44 vs. f43 plot, and this finding can be potentially used as a tool for source apportionment of measured particles.

Rapid Identification of High Particle Number Emitting On-Road Vehicles and Its Application to a Large Fleet of Diesel Buses

Publisher: American Chemical Society (ACS)

Date: 12-06-2007

DOI: 10.1021/ES063020V

Abstract: Pollutant concentrations measured in the exhaust plume of a vehicle may be related to the pollutant emission factor using the CO2 concentration as a measure of the dilution factor. We have used this method for the rapid identification of high particle number (PN) emitting on-road vehicles. The method was validated for PN using a medium-duty vehicle and successfully applied to measurements of PN emissions from a large fleet of on-road diesel buses. The ratio of PN concentration to CO2 concentration, Z, in the exhaust plume was estimated for in idual buses. On the average, a bus emitted about 1.5 x 10(9) particles per mg of CO2 emitted. A histogram of the number of buses as a function of Z showed, for the first time, that the PN emissions from diesel buses followed a gamma distribution, with most of the values within a narrow range and a few buses exhibiting relatively large values. It was estimated that roughly 10% and 50% of the PN emissions came from just 2% and 25% of the buses, respectively. A regression analysis showed that there was a positive correlation between Z and age of buses, with the slope of the best line being significantly different from zero. The mean Z value for the pre-Euro buses was significantly greater than each of the values for the Euro I and II buses.

Soot particle morphology and nanostructure with oxygenated fuels: A comparative study into cold-start and hot-start operation

Publisher: Elsevier BV

Date: 04-2021

DOI: 10.1016/J.ENVPOL.2021.116592

Characterization of the Particle Emission from Ships Operating at Sea Using Unmanned Aerial Vehicles

Publisher: Copernicus GmbH

Date: 26-06-2017

DOI: 10.5194/AMT-2017-146

Abstract: Abstract. This research demonstrates the use of an unmanned aerial vehicle (UAV) to characterize the gaseous (CO2) and particle (10–500 nm) emissions of a ship at sea. The field study was part of the research voyage The Great Barrier Reef as a significant source of climatically relevant aerosol particles on-board the RV Investigator around the Australian Great Barrier Reef. Measurements of the RV Investigator exhaust plume were carried out while the ship was operating at sea, at a steady engine load of 30 %. The UAV system was flown autonomously using several different programmed paths. These incorporated different altitudes and distances behind the ship in order to investigate the optimal position to capture the ship plume. Five flights were performed, providing a total of 27 horizontal transects perpendicular to the ship exhaust plume. Results show that the most appropriate altitude and distance to effectively capture the plume was 25 m above sea level and 20 m downwind. Particle number (PN) emission factors (EF) were calculated in terms of number of particles emitted (#) per weight of fuel consumed (Kg fuel). Fuel consumption was calculated using the simultaneous measurements of plume CO2 concentration. Calculated EFPN were between 9.19 × 1014 and 5.15 × 1015 #∙(Kg fuel)−1. These values are in line with those reported in the literature for ship emissions ranging from 0.2 6.2 × 1016 #∙(Kg fuel)−1 to 6.2 × 1016 #∙(Kg fuel)−1. This UAV system successfully assessed ship emissions to derive emission factors (EFs) under real world conditions. This is significant as, for the first time, it provides a reliable, inexpensive and accessible way to assess and potentially regulate ship emissions.

Cough-generated aerosols of pseudomonas aeruginosa and other Gram-negative bacteria from patients with cystic fibrosis

Publisher: BMJ

Date: 07-2009

DOI: 10.1136/THX.2008.112466

Atmospheric Aerosol and Ion Characteristics during EUCAP (Eucalypt Forest Aerosols and Precursors)

Publisher: Springer Netherlands

Date: 2007

DOI: 10.1007/978-1-4020-6475-3_186

The role of sulphates and organic vapours in growth of newly formed particles in a eucalypt forest

Publisher: Copernicus GmbH

Date: 29-03-2010

DOI: 10.5194/ACP-10-2919-2010

Abstract: Abstract. The influence of biogenic particle formation on climate is a well recognised phenomenon. To understand the mechanisms underlying the biogenic particle formation, determining the chemical composition of the new particles and therefore the species that drive the particle production is of utmost importance. Due to the very small amount of mass involved, indirect approaches are frequently used to infer the composition. We present here the results of such an indirect approach by simultaneously measuring volatile and hygroscopic properties of newly formed particles in a forest environment. It is shown that the particles are composed of both sulphates and organics, with the amount of sulphate component strongly depending on the available gas-phase sulphuric acid, and the organic components having the same volatility and hygroscopicity as photo-oxidation products of a monoterpene such as α-pinene. Our findings agree with a two-step process through nucleation and cluster formation followed by simultaneous growth by condensation of sulphates and organics that take the particles to climatically relevant sizes.

The Arctic Summer Cloud-Ocean Study (ASCOS): overview and experimental design

Publisher: Copernicus GmbH

Date: 23-05-2013

DOI: 10.5194/ACPD-13-13541-2013

Abstract: Abstract. The climate in the Arctic is changing faster than anywhere else on Earth. Poorly understood feedback processes relating to Arctic clouds and aerosol-cloud interactions contribute to a poor understanding of the present changes in the Arctic climate system, and also to a large spread in projections of future climate in the Arctic. The problem is exacerbated by the paucity of research-quality observations in the central Arctic. Improved formulations in climate models require such observations, which can only come from measurements in-situ in this difficult to reach region with logistically demanding environmental conditions. The Arctic Summer Cloud-Ocean Study (ASCOS) was the most extensive central Arctic Ocean expedition with an atmospheric focus during the International Polar Year (IPY) 2007–2008. ASCOS focused on the study of the formation and life cycle of low-level Arctic clouds. ASCOS departed from Longyearbyen on Svalbard on 2 August and returned on 9 September 2008. In transit into and out of the pack ice, four short research stations were undertaken in the Fram Strait two in open water and two in the marginal ice zone. After traversing the pack-ice northward an ice c was set up on 12 August at 87°21' N 01°29' W and remained in operation through 1 September, drifting with the ice. During this time extensive measurements were taken of atmospheric gas and particle chemistry and physics, mesoscale and boundary-layer meteorology, marine biology and chemistry, and upper ocean physics. ASCOS provides a unique interdisciplinary data set for development and testing of new hypotheses on cloud processes, their interactions with the sea ice and ocean and associated physical, chemical, and biological processes and interactions. For ex le, the first ever quantitative observation of bubbles in Arctic leads, combined with the unique discovery of marine organic material, polymer gels with an origin in the ocean, inside cloud droplets suggest the possibility of primary marine organically derived cloud condensation nuclei in Arctic stratocumulus clouds. Direct observations of surface fluxes of aerosols could, however, not explain observed variability in aerosol concentrations and the balance between local and remote aerosols sources remains open. Lack of CCN was at times a controlling factor in low-level cloud formation, and hence for the impact of clouds on the surface energy budget. ASCOS provided detailed measurements of the surface energy balance from late summer melt into the initial autumn freeze-up, and documented the effects of clouds and storms on the surface energy balance during this transition. In addition to such process-level studies, the unique, independent ASCOS data set can and is being used for validation of satellite retrievals, operational models, and reanalysis data sets.

Volatile Properties of Particles Emitted by Compressed Natural Gas and Diesel Buses during Steady-State and Transient Driving Modes

Publisher: American Chemical Society (ACS)

Date: 12-12-2011

DOI: 10.1021/ES2026856

Abstract: Volatile properties of particle emissions from four compressed natural gas (CNG) and four diesel buses were investigated under steady-state and transient driving modes on a chassis dynamometer. The exhaust was diluted utilizing a full-flow continuous volume s ling system and passed through a thermodenuder at controlled temperature. Particle number concentration and size distribution were measured with a condensation particle counter and a scanning mobility particle sizer, respectively. We show that while almost all the particles emitted by the CNG buses were in the nanoparticle size range, at least 85% and 98% were removed at 100 and 250 °C, respectively. Closer analysis of the volatility of particles emitted during transient cycles showed that volatilization began at around 40 °C, with the majority occurring by 80 °C. Particles produced during hard acceleration from rest exhibited lower volatility than those produced during other times of the cycle. On the basis of our results and the observation of ash deposits on the walls of the tailpipes, we suggest that these nonvolatile particles were composed mostly of ash from lubricating oil. Heating the diesel bus emissions to 100 °C removed ultrafine particle numbers by 69-82% when a nucleation mode was present and just 18% when it was not.

Synthesize of magnetite Mg-Fe mixed metal oxide nanocatalyst by urea-nitrate combustion method with optimal fuel ratio for reduction of emissions in diesel engines

Publisher: Elsevier BV

Date: 10-2020

DOI: 10.1016/J.JALLCOM.2020.155627

Influence of fuel-borne oxygen on European Stationary Cycle: Diesel engine performance and emissions with a special emphasis on particulate and NO emissions

Publisher: Elsevier BV

Date: 11-2016

DOI: 10.1016/J.ENCONMAN.2016.09.010

Effect of atmospheric ageing on volatility and ROS of biodiesel exhaust nano-particles

Publisher: Copernicus GmbH

Date: 05-03-2015

DOI: 10.5194/ACPD-15-6481-2015

Abstract: Abstract. In the prospect of limited energy resources and climate change, effects of alternative biofuels on primary emissions are being extensively studied. Our two recent studies have shown that biodiesel fuel composition has a~significant impact on primary particulate matter emissions. It was also shown that particulate matter caused by biodiesels was substantially different from the emissions due to petroleum diesel. Emissions appeared to have higher oxidative potential with the increase in oxygen content and decrease of carbon chain length and unsaturation levels of fuel molecules. Overall, both studies concluded that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions. This suggests that the atmospheric ageing processes, including secondary organic aerosol formation, of emissions from different fuels will be different as well. In this study, measurements were conducted on a modern common-rail diesel engine. To get more information on realistic properties of tested biodiesel particulate matter once they are released into the atmosphere, particulate matter was exposed to atmospheric oxidants, ozone and ultra-violet light and the change in their properties was monitored for different biodiesel blends. Upon the exposure to oxidative agents, the chemical composition of the exhaust changes. It triggers the cascade of photochemical reactions resulting in the partitioning of semi-volatile compounds between the gas and particulate phase. In most of the cases, aging lead to the increase in volatility and oxidative potential, and the increment of change was mainly dependent on the chemical composition of fuels as the leading cause for the amount and the type of semi-volatile compounds present in the exhaust.

Review-evaluating the molecular assays for measuring the oxidative potential of particulate matter

Publisher: National Library of Serbia

Date: 2015

DOI: 10.2298/CICEQ140228031H

Abstract: Several cell-free assays are currently used to quantify and detect the Reactive Oxygen Species (ROS). All of them have certain limitations, do not provide direct comparison of results and, to date, none of these assays have been acknowledged as the most suitable acellular assay and none has yet been adopted for investigation of potential PM toxicity. These assays include DTT, ascorbic acid, DCFHDA and PFN assays which have been used in measurements of the particles generated from various combustion sources such as diesel engine, wood smoke (or biomass burning) and cigarette smoke, as well as for outdoor measurements. All the probes use different units for expressing redox properties of PM. Also, their reactivity is being triggered by different types of ROS. This limits the direct comparison of the results that are reporting the toxicity of the same aerosol type measured with various probes. This study is evaluating and comparing the various assays in order to develop deeper understanding of their capabilities, selectivity as well as improve understanding of the underlying chemical mechanisms.

Supplementary material to "An Overview of the Surface Ocean Aerosol Production (SOAP) campaign"

Publisher: Copernicus GmbH

Date: 20-06-2017

DOI: 10.5194/ACP-2017-535-SUPPLEMENT

Humidity-dependent survival of an airborne influenza a virus: Practical implications for controlling airborne viruses

Publisher: American Chemical Society (ACS)

Date: 20-04-2021

DOI: 10.1021/ACS.ESTLETT.1C00253

Marine aerosol hygroscopicity and volatility, measured on the Chatham Rise (New Zealand)

Publisher: AIP

Date: 2013

DOI: 10.1063/1.4803329

The Arctic Summer Cloud Ocean Study (ASCOS): overview and experimental design

Publisher: Copernicus GmbH

Date: 19-03-2014

DOI: 10.5194/ACP-14-2823-2014

Abstract: Abstract. The climate in the Arctic is changing faster than anywhere else on earth. Poorly understood feedback processes relating to Arctic clouds and aerosol–cloud interactions contribute to a poor understanding of the present changes in the Arctic climate system, and also to a large spread in projections of future climate in the Arctic. The problem is exacerbated by the paucity of research-quality observations in the central Arctic. Improved formulations in climate models require such observations, which can only come from measurements in situ in this difficult-to-reach region with logistically demanding environmental conditions. The Arctic Summer Cloud Ocean Study (ASCOS) was the most extensive central Arctic Ocean expedition with an atmospheric focus during the International Polar Year (IPY) 2007–2008. ASCOS focused on the study of the formation and life cycle of low-level Arctic clouds. ASCOS departed from Longyearbyen on Svalbard on 2 August and returned on 9 September 2008. In transit into and out of the pack ice, four short research stations were undertaken in the Fram Strait: two in open water and two in the marginal ice zone. After traversing the pack ice northward, an ice c was set up on 12 August at 87°21' N, 01°29' W and remained in operation through 1 September, drifting with the ice. During this time, extensive measurements were taken of atmospheric gas and particle chemistry and physics, mesoscale and boundary-layer meteorology, marine biology and chemistry, and upper ocean physics. ASCOS provides a unique interdisciplinary data set for development and testing of new hypotheses on cloud processes, their interactions with the sea ice and ocean and associated physical, chemical, and biological processes and interactions. For ex le, the first-ever quantitative observation of bubbles in Arctic leads, combined with the unique discovery of marine organic material, polymer gels with an origin in the ocean, inside cloud droplets suggests the possibility of primary marine organically derived cloud condensation nuclei in Arctic stratocumulus clouds. Direct observations of surface fluxes of aerosols could, however, not explain observed variability in aerosol concentrations, and the balance between local and remote aerosols sources remains open. Lack of cloud condensation nuclei (CCN) was at times a controlling factor in low-level cloud formation, and hence for the impact of clouds on the surface energy budget. ASCOS provided detailed measurements of the surface energy balance from late summer melt into the initial autumn freeze-up, and documented the effects of clouds and storms on the surface energy balance during this transition. In addition to such process-level studies, the unique, independent ASCOS data set can and is being used for validation of satellite retrievals, operational models, and reanalysis data sets.

Performance assessment of UVAPS: Influence of fungal spore age and air exposure

Publisher: Elsevier BV

Date: 2007

DOI: 10.1016/J.JAEROSCI.2006.10.003

Role of semi-volatile particulate matter in gas-particle partitioning leading to change in oxidative potential

Publisher: Elsevier BV

Date: 02-2021

DOI: 10.1016/J.ENVPOL.2020.116061

Combustion Analysis of a Diesel Engine during Warm up at Different Coolant and Lubricating Oil Temperatures

Publisher: MDPI AG

Date: 08-2020

DOI: 10.3390/EN13153931

Abstract: A comprehensive analysis of combustion behaviour during cold, intermediately cold, warm and hot start stages of a diesel engine are presented. Experiments were conducted at 1500 rpm and 2000 rpm, and the discretisation of engine warm up into stages was facilitated by designing a custom drive cycle. Advanced injection timing, observed during the cold start period, led to longer ignition delay, shorter combustion duration, higher peak pressure and a higher peak apparent heat release rate (AHRR). The peak pressure was ~30% and 20% and the AHRR was ~2 to 5% and ±1% higher at 1500 rpm and 2000 rpm, respectively, during cold start, compared to the intermediate cold start. A retarded injection strategy during the intermediate cold start phase led to shorter ignition delay, longer combustion duration, lower peak pressure and lower peak AHRR. At 2000 rpm, an exceptional combustion behaviour led to a ~27% reduction in the AHRR at 25% load. Longer ignition delays and shorter combustion durations at 25% load were observed during the intermediately cold, warm and hot start segments. The mass fraction burned (MFB) was calculated using a single zone combustion model to analyse combustion parameters such as crank angle (CA) at 50% MFB, AHRR@CA50 and CA duration for 10–90% MFB.

Comparison of manual and automatic approaches for characterisation of morphology and nanostructure of soot particles

Publisher: Elsevier BV

Date: 10-2019

DOI: 10.1016/J.JAEROSCI.2019.07.001

Sea spray aerosol organic enrichment, water uptake and surface tension effects

Publisher: Copernicus GmbH

Date: 19-09-2019

DOI: 10.5194/ACP-2019-797

Abstract: Abstract. The aerosol driven radiative effects on marine low-level cloud represent a large uncertainty in climate simulations, in particular over the Southern Ocean, which is also an important region for sea spray aerosol production. Observations of sea spray aerosol organic enrichment and the resulting impact on water uptake over the remote southern hemisphere are scarce, and are therefore the region is under-represented in existing parameterisations. The Surface Ocean Aerosol Production (SOAP) voyage was a 23 day voyage which s led three phytoplankton blooms in the highly productive water of the Chatham Rise, east of New Zealand. In this study we examined the enrichment of organics to nascent sea spray aerosol and the modifications to sea spray aerosol water uptake using in-situ chamber measurements of seawater s les taken during the SOAP voyage. Primary marine organics contributed up to 23 % of the sea spray mass for particles with diameter less than approximately 1 μm, and up to 87 % of the particle volume in the Aitken mode. The composition of the organic fraction was consistent throughout the voyage and was largely comprised of a polysaccharide-like component, characterised by very low alkane to hydroxyl concentration ratios of approximately 0.1–0.2. The enrichment of organics was compared to the output from the chlorophyll-a based sea spray aerosol parameterisation suggested by Gantt et al. (2011) and the OCEANFILMS models. OCEANFILMS improved on the representation of the organic fraction predicted using chlorophyll-a, in particular when the co-adsoprtion of polysaccharides was included, however the model still under predicted the proportion of polysaccharides by an average of 33 %. Nascent sea spray aerosol hygroscopic growth factors averaged 1.93 ± 0.08, and did not decrease with increasing sea spray aerosol organic fractions. The observed hygroscopicity was greater than expected from the assumption of full solubility, particularly during the most productive phytoplankton bloom (B1), during which organic fractions were greater than approximately 0.4. The water uptake behaviour observed in this study is consistent with that observed for other measurements of phytoplankton blooms, and was attributed to the surface partitioning of the organic components which leads to a decrease in particle surface tension and an increase in hygroscopicity. The compressed film model was used to estimate the influence of surface partitioning and the error in the modelled hygroscopicity was low only when the entire organic fraction was available to partition to the particle surface. The modelled sea spray aerosol hygroscopicity at high organic fractions was underestimated when only a portion of the organic component was available to be partitioned to the surface. The findings from the SOAP voyage highlight the influence of biologically-sourced organics on sea spray aerosol composition, these data improve the capacity to parameterise sea spray aerosol organic enrichment and water uptake.

Influence of oxygen content of the certain types of biodiesels on particulate oxidative potential

Publisher: Elsevier BV

Date: 03-2016

DOI: 10.1016/J.SCITOTENV.2015.12.036

Abstract: Oxidative potential (OP) is related to the organic phase, specifically to its oxygenated organic fraction (OOA). Furthermore, the oxygen content of fuel molecules has significant influence on particulate OP. Thus, this study aimed to explore the actual dependency of the OOA and ROS to the oxygen content of the fuel. In order to reach the goal, different biodiesels blends, with various ranges of oxygen content have been employed. The compact time of flight aerosol mass spectrometer (c-ToF AMS) enabled better identification of OOA. ROS monitored by using two assays: DTT and BPEA-nit. Despite emitting lower mass, both assays agreed that oxygen content of a biodiesel is directly correlated with its OOA, and highly related to its OP. Hence, the more oxygen included in the considered biodiesels, the higher the OP of PM emissions. This highlights the importance of taking oxygen content into account while assessing emissions from new fuel types, which is relevant from a health effects standpoint.

E-cigarettes induce toxicity comparable to tobacco cigarettes in airway epithelium from patients with COPD

Publisher: Elsevier BV

Date: 09-2021

DOI: 10.1016/J.TIV.2021.105204

An overview of the influence of biodiesel, alcohols, and various oxygenated additives on the particulate matter emissions from diesel engines

Publisher: MDPI AG

Date: 23-05-2019

DOI: 10.3390/EN12101987

Abstract: Rising pollution levels resulting from vehicular emissions and the depletion of petroleum-based fuels have left mankind in pursuit of alternatives. There are stringent regulations around the world to control the particulate matter (PM) emissions from internal combustion engines. To this end, researchers have been exploring different measures to reduce PM emissions such as using modern combustion techniques, after-treatment systems such as diesel particulate filter (DPF) and gasoline particulate filter (GPF), and alternative fuels. Alternative fuels such as biodiesel (derived from edible, nonedible, and waste resources), alcohol fuels (ethanol, n-butanol, and n-pentanol), and fuel additives have been investigated over the last decade. PM characterization and toxicity analysis is still growing as researchers are developing methodologies to reduce particle emissions using various approaches such as fuel modification and after-treatment devices. To address these aspects, this review paper studies the PM characteristics, health issues, PM physical and chemical properties, and the effect of alternative fuels such as biodiesel, alcohol fuels, and oxygenated additives on PM emissions from diesel engines. In addition, the correlation between physical and chemical properties of alternate fuels and the characteristics of PM emissions is explored.

Emissions from a vehicle fitted to operate on either petrol or compressed natural gas

Publisher: Elsevier BV

Date: 05-05-2004

DOI: 10.1016/J.SCITOTENV.2003.10.023

Emission factors of trace gases and particles from tropical savanna fires in Australia

Publisher: American Geophysical Union (AGU)

Date: 10-06-2017

DOI: 10.1002/2016JD025925

Assessing the Effect of Reactive Oxygen Species and Volatile Organic Compound Profiles Coming from Certain Types of Chinese Cooking on the Toxicity of Human Bronchial Epithelial Cells

Publisher: American Chemical Society (ACS)

Date: 09-06-2020

DOI: 10.1021/ACS.EST.9B07553

Modular design of profluorescent polymer sensors

Publisher: Royal Society of Chemistry (RSC)

Date: 2015

DOI: 10.1039/C5PY00120J

Abstract: Through orthogonal coupling chemistries, the synthesis of profluorescent nitroxide containing polymers for applications as radical or redox sensors is achieved.

Nanomechanics and Morphology of Simulated Respiratory Particles

Publisher: American Chemical Society (ACS)

Date: 19-07-2022

DOI: 10.1021/ACS.EST.2C01829

Abstract: The impact of respiratory particle composition on the equilibrium morphology and phase is not well understood. Furthermore, the effects of these different phases and morphologies on the viability of viruses embedded within these particles are equally unknown. Physiologically relevant respiratory fluid analogues were constructed, and their hygroscopic behavior was measured using an ensemble technique. A relationship between hygroscopicity and protein concentration was determined, providing additional validation to the high protein content of respiratory aerosol measured in prior works (>90%). It was found that the salt component of the respiratory particles could crystallize as a single crystal, multiple crystals, or would not crystallize at all. It was found that dried protein particles at indoor-relevant climatic conditions could exist separately in a glassy (∼77% of particles) or viscoelastic state (∼23% of particles). The phase state and morphology of respiratory particles may influence the viability of embedded pathogens. We recommend that pathogen research aiming to mimic the native composition of respiratory fluid should use a protein concentration of at least 90% by solute volume to improve the representativity of the pathogen's microenvironment.

Dimethyl sulfide and other biogenic volatile organic compound emissions from branching coral and reef seawater: potential sources of secondary aerosol over the Great Barrier Reef

Publisher: Springer Science and Business Media LLC

Date: 22-01-2016

DOI: 10.1007/S10874-016-9327-7

Performance and exhaust emissions of diesel engines using microalgae FAME and the prospects for microalgae HTL biocrude

Publisher: Elsevier BV

Date: 02-2018

DOI: 10.1016/J.RSER.2017.06.026

Engine performance characteristics for biodiesels of different degrees of saturation and carbon chain lengths

Publisher: SAE International

Date: 08-04-2013

DOI: 10.4271/2013-01-1680

Primary human bronchial epithelial cell responses to diesel and novel biodiesel emissions

Publisher: European Respiratory Society

Date: 15-09-2018

DOI: 10.1183/13993003.CONGRESS-2018.PA4243

Conduction of heat in inhomogeneous solids

Publisher: AIP Publishing

Date: 20-07-1998

DOI: 10.1063/1.121821

Abstract: In this letter we present a method for calculation of linear heat flow in inhomogeneous solids. The method is based on the evaluation of transfer matrices for each layer in a multilayered structure from the Laplace transformation of the partial differential equation of heat conduction. The multilayered structure is then described by a matrix obtained as a chain of products of in idual layer transfer matrices and corresponding boundary thermal resistivity matrices. The analytic expression for the nth power of the multilayered transfer matrix is found, describing a periodic multilayered structure composed of n equal multilayered structures. The application of the presented method for calculation of photothermal signals is also shown. Dispersion relation for the thermal waves in inhomogeneous solids is obtained from the matrix elements of the transfer matrix. Finally, from the dispersion relation explicit expressions for the effective values of thermal diffusivity and conductivity of both the discontinuously and continuously inhomogeneous solids are evaluated.

Experimental investigations of physical and chemical properties for microalgae HTL bio-crude using a large batch reactor

Publisher: MDPI AG

Date: 05-04-2017

DOI: 10.3390/EN10040467

Elemental composition of combustion emissions from spark ignition vehicles

Publisher: Elsevier BV

Date: 09-1999

DOI: 10.1016/S0021-8502(99)80433-9

Should industrial bagasse-fired boilers be phased out in China?

Publisher: Elsevier BV

Date: 08-2020

DOI: 10.1016/J.JCLEPRO.2020.121716

Characterization of VOCs from LPG and unleaded petroleum fuelled passenger cars

Publisher: Elsevier BV

Date: 2014

DOI: 10.1016/J.FUEL.2013.06.031

A comparative study of the elemental composition of the exhaust emissions of cars powered by liquefied petroleum gas and unleaded petrol

Publisher: Elsevier BV

Date: 06-2006

DOI: 10.1016/J.ATMOSENV.2006.01.007

Fuel characterisation, engine performance, combustion and exhaust emissions with a new renewable Licella biofuel

Publisher: Elsevier BV

Date: 05-2015

DOI: 10.1016/J.ENCONMAN.2015.02.085

Primary human bronchial epithelial cell responses to diesel and biodiesel emissions at an air-liquid interface

Publisher: Elsevier BV

Date: 06-2019

DOI: 10.1016/J.TIV.2019.02.005

Abstract: Diesel emissions have a high level of particulate matter which can cause inflammation and oxidative stress in the airways. A strategy to reduce diesel particulate matter and the associated adverse effects is the use of biodiesels and fuel additives. However, very little is known about the biological effects of these alternative emissions. The aim of this study is to compare the effect of biodiesel and triacetin/biodiesel emissions on primary human bronchial epithelial cells (pHBECs) compared to diesel emissions. pHBECs were exposed to diesel, biodiesel (20%, 50% and 100% biodiesel derived from coconut oil) and triacetin/biodiesel (4% and 10% triacetin) emissions for 30 min at air-liquid interface. Cell viability (cellular metabolism, cell death, CASP3 mRNA expression and BCL2 mRNA expression), inflammation (IL-8 and IL-6 secretion), antioxidant production (HO-1 mRNA expression) and xenobiotic metabolism (CYP1a1 mRNA expression) were measured. Biodiesel emissions (B50) reduced cell viability, and increased oxidative stress. Triacetin/biodiesel emissions (B90) decreased cell viability and increased antioxidant production, inflammation and xenobiotic metabolism. Biodiesel emissions (B100) reduced cell viability, and increased IL-8 secretion and xenobiotic metabolism. Biodiesel substitution in diesel fuel and triacetin substitution in biodiesel can increase the adverse effects of diesel emissions of pHBECs. Further studies of the effect of these diesel fuel alternatives on pHBECs are required.

Assessment and application of clustering techniques to atmospheric particle number size distribution for the purpose of source apportionment

Publisher: Copernicus GmbH

Date: 12-11-2014

DOI: 10.5194/ACP-14-11883-2014

Abstract: Abstract. Long-term measurements of particle number size distribution (PNSD) produce a very large number of observations and their analysis requires an efficient approach in order to produce results in the least possible time and with maximum accuracy. Clustering techniques are a family of sophisticated methods that have been recently employed to analyse PNSD data however, very little information is available comparing the performance of different clustering techniques on PNSD data. This study aims to apply several clustering techniques (i.e. K means, PAM, CLARA and SOM) to PNSD data, in order to identify and apply the optimum technique to PNSD data measured at 25 sites across Brisbane, Australia. A new method, based on the Generalised Additive Model (GAM) with a basis of penalised B-splines, was proposed to parameterise the PNSD data and the temporal weight of each cluster was also estimated using the GAM. In addition, each cluster was associated with its possible source based on the results of this parameterisation, together with the characteristics of each cluster. The performances of four clustering techniques were compared using the Dunn index and Silhouette width validation values and the K means technique was found to have the highest performance, with five clusters being the optimum. Therefore, five clusters were found within the data using the K means technique. The diurnal occurrence of each cluster was used together with other air quality parameters, temporal trends and the physical properties of each cluster, in order to attribute each cluster to its source and origin. The five clusters were attributed to three major sources and origins, including regional background particles, photochemically induced nucleated particles and vehicle generated particles. Overall, clustering was found to be an effective technique for attributing each particle size spectrum to its source and the GAM was suitable to parameterise the PNSD data. These two techniques can help researchers immensely in analysing PNSD data for characterisation and source apportionment purposes.

Measurement of Airborne Particles

Publisher: Wiley

Date: 29-10-2003

DOI: 10.1002/9783527610013.CH2B

Engine Performance during Transient and Steady-State Operation with Oxygenated Fuels

Publisher: American Chemical Society (ACS)

Date: 20-06-2017

DOI: 10.1021/ACS.ENERGYFUELS.7B00429

Real-time monitoring of viable bioaerosols: capability of the UVAPS to predict the amount of individual microorganisms in aerosol particles

Publisher: Elsevier BV

Date: 05-2005

DOI: 10.1016/J.JAEROSCI.2004.12.005

Size-Selective Assessment of Airborne Particles in Swine Confinement Building with the UVAPS

Publisher: Elsevier BV

Date: 07-2004

DOI: 10.1016/J.ATMOSENV.2004.02.058

In-cylinder pressure reconstruction by engine acoustic emission

Publisher: Elsevier BV

Date: 05-2021

DOI: 10.1016/J.YMSSP.2020.107490

Ternary Nucleation as a Mechanism for the Production of Diesel Nanoparticles:  Experimental Analysis of the Volatile and Hygroscopic Properties of Diesel Exhaust Using the Volatilization and Humidific

Publisher: American Chemical Society (ACS)

Date: 25-09-2007

DOI: 10.1021/ES062574V

Abstract: The volatile and hygroscopic properties of diesel nanoparticles were simultaneously determined under a range of engine loads using the volatilization and humidification tandem differential mobility analyzer (VH-TDMA). Additionally, the VH-TDMA was used to measure changes in the hygroscopic behavior of the heterogeneously nucleated diesel nanoparticles as one or more semivolatile species were removed via thermal evaporation or decomposition. Particles produced at high loads exhibited high, dual-step volatility, while those particles produced at low loads were less volatile and exhibited continuous volatilization curves. The hygroscopic growth factor of the particles was shown to be load dependent with high-load particles exhibiting growth factors similar to that of ammonium sulfate. At 85% relative humidity, particles produced at moderate loads exhibited growth factors of approximately 1.1 while low-load particles were shown to be hydrophobic. Growth factors and volatilization temperatures measured for high-load particles clearly indicate that ternary nucleation is involved in particle formation.

Novel Method for On-Road Emission Factor Measurements Using a Plume Capture Trailer

Publisher: American Chemical Society (ACS)

Date: 08-12-2007

DOI: 10.1021/ES060179Z

Abstract: The method outlined provides for emission factor measurements to be made for unmodified vehicles driving under real world conditions at minimal cost. The method consists of a plume capture trailer towed behind a test vehicle. The trailer collects a s le of the naturally diluted plume in a 200 L conductive bag and this is delivered immediately to a mobile laboratory for subsequent analysis of particulate and gaseous emissions. The method offers low test turnaround times with the potential to complete much larger numbers of emission factor measurements than have been possible using dynamometer testing. S les can be collected at distances up to 3 m from the exhaust pipe allowing investigation of early dilution processes. Particle size distribution measurements, as well as particle number and mass emission factor measurements, based on naturally diluted plumes are presented. A dilution profile relating the plume dilution ratio to distance from the vehicle tail pipe for a diesel passenger vehicle is also presented. Such profiles are an essential input for new mechanistic roadway air quality models.

Particulate emissions and soot characterisation of diesel engine exhaust for steady-state operating condition using dioctyl phthalate blends with diesel

Publisher: Elsevier BV

Date: 05-2023

DOI: 10.1016/J.FUEL.2023.127527

Diesel engine performance and emissions with fuels derived from waste tyres

Publisher: Springer Science and Business Media LLC

Date: 06-02-2018

DOI: 10.1038/S41598-018-19330-0

Abstract: The disposal of waste rubber and scrap tyres is a significant issue globally disposal into stockpiles and landfill poses a serious threat to the environment, in addition to creating ecological problems. Fuel production from tyre waste could form part of the solution to this global issue. Therefore, this paper studies the potential of fuels derived from waste tyres as alternatives to diesel. Production methods and the influence of reactor operating parameters (such as reactor temperature and catalyst type) on oil yield are outlined. These have a major effect on the performance and emission characteristics of diesel engines when using tyre derived fuels. In general, tyre derived fuels increase the brake specific fuel consumption and decrease the brake thermal efficiency. The majority of studies indicate that NOx emissions increase with waste tyre derived fuels however, a few studies have reported the opposite trend. A similar increasing trend has been observed for CO and CO 2 emissions. Although most studies reported an increase in HC emission owing to lower cetane number and higher density, some studies have reported reduced HC emissions. It has been found that the higher aromatic content in such fuels can lead to increased particulate matter emissions.

Size distribution of particles emitted from grass fires in the Northern Territory, Australia

Publisher: Elsevier BV

Date: 12-2007

DOI: 10.1016/J.ATMOSENV.2007.07.020

Influence of fuel molecular structure on the volatility and oxidative potential of biodiesel particulate matter

Publisher: American Chemical Society (ACS)

Date: 27-10-2014

DOI: 10.1021/ES503160M

Abstract: We have studied the effect of chemical composition of biodiesel fuel on the physical (volatility) and chemical (reactive oxygenated species concentration) properties of nano particles emitted from a modern common-rail diesel engine. Particle emissions from the combustion of four biodiesels with controlled chemical compositions and different varying unsaturation degrees and carbon-chain lengths, together with a commercial diesel, were tested and compared in terms of volatility of particles and the amount of reactive oxygenated species carried by particles. Different blends of biodiesel and petro diesel were tested at several engine loads and speeds. We have observed that more saturated fuels with shorter carbon chain lengths result in lower particle mass but produce particles that are more volatile and also have higher levels of Reactive Oxygen Species. This highlights the importance of taking into account metrics that are relevant from the health effects point of view when assessing emissions from new fuel types.

Detection of misfire in a six-cylinder diesel engine using acoustic emission signals

Publisher: American Society of Mechanical Engineers

Date: 09-11-2018

DOI: 10.1115/IMECE2018-86506

Abstract: This study will focus on the detection of misfire using Acoustic emission sensor in a multi-cylinder diesel engine. Detection of misfire is important since this malfunction can cause the engine to stall in a short time. In order to investigate the misfire, an experimental engine was run with and without injection of the fuel in the first cylinder. The acoustic emission signal was acquired synchronously with the crank angle signal, in order to have a reference for the transformation from time to angular domain. The AE signal was then processed using the squared envelope spectrum to highlight angle-periodic modulations in the signal’s power (cyclic bursts). This study will present the effectiveness of this combination of sensor technology and signal processing to detect misfire in a six-cylinder diesel engine connected to a hydraulic dynamometer.

Intercomparison study of six HTDMAs: results and recommendations

Publisher: Copernicus GmbH

Date: 24-07-2009

DOI: 10.5194/AMT-2-363-2009

Abstract: Abstract. We report on an intercomparison of six different hygroscopicity tandem differential mobility analysers HTDMAs). These HTDMAs are used worldwide in laboratory experiments and field c aigns to measure the water uptake of aerosol particles and have never been intercompared. After an investigation of the different design of the instruments with their advantages and inconveniencies, the methods for calibration, validation and data analysis are presented. Measurements of nebulised ammonium sulphate as well as of secondary organic aerosol generated from a smog chamber were performed. Agreement and discrepancies between the instruments and to the theory are discussed, and final recommendations for a standard instrument are given, as a benchmark for laboratory or field experiments to ensure a high quality of HTDMA data.

Engine blow-by with oxygenated fuels: A comparative study into cold and hot start operation

Publisher: Elsevier BV

Date: 12-2017

DOI: 10.1016/J.ENERGY.2017.08.115

Odour, dust and non-methane volatile organic-compound emissions from tunnel-ventilated layer-chicken sheds: A case study of two farms

Publisher: CSIRO Publishing

Date: 2013

DOI: 10.1071/AN12343

Abstract: An observational study was undertaken to measure odour and dust (PM10 and PM2.5) emission rates and identify non-methane volatile organic compounds (NMVOCs) and odorants in the exhaust air from two tunnel-ventilated layer-chicken sheds that were configured with multi-tiered cages and manure belts. The study sites were located in south-eastern Queensland and the West Gippsland region of Victoria, Australia. S les were collected in summer and winter on sequential days across the manure-belt cleaning cycle. Odour emissions ranged from 58 to 512 ou/s per 1000 birds (0.03–0.27 ou/s.kg) and dust emission rates ranged 0.014–0.184 mg/s per 1000 birds for PM10 and 0.001–0.190 mg/s per 1000 birds for PM2.5. Twenty NMVOCs were identified, including three that were also identified as odorants using thermal desorption–gas chromatography–mass spectrometry/olfactometry analysis. Odour emission rates were observed to vary with the amount of manure accumulation on the manure belts, being lowest 2–4 days after removing manure. Odour emission rates were also observed to vary with diurnal and seasonal changes in ventilation rate. Dust emissions were observed to increase with ventilation rate but not with manure accumulation. Some NMVOCs were identified at both farms and in different seasons whereas others were observed only at one farm or in one season, indicating that odorant composition was influenced by farm-specific practices and season.

Theoretical analysis of the motion and evaporation of exhaled respiratory droplets of mixed composition

Publisher: Elsevier BV

Date: 2011

DOI: 10.1016/J.JAEROSCI.2010.10.005

Method for measuring the hygroscopic behaviour of lower volatility fractions in an internally mixed aerosol

Publisher: Elsevier BV

Date: 04-2004

DOI: 10.1016/J.JAEROSCI.2003.10.008

Investigating particles, VOCs, ROS produced from mosquito-repellent incense emissions and implications in SOA formation and human health

Publisher: Elsevier BV

Date: 10-2018

DOI: 10.1016/J.BUILDENV.2018.07.053

Submicron particle emissions from compressed natural gas engines

Publisher: Elsevier BV

Date: 09-1999

DOI: 10.1016/S0021-8502(99)80276-6

Effect of sulphur and vanadium spiked fuels on particle characteristics and engine performance of auxiliary diesel engines

Publisher: Elsevier BV

Date: 12-2018

DOI: 10.1016/J.ENVPOL.2018.08.055

Abstract: Particle emission characteristics and engine performance were investigated from an auxiliary, heavy duty, six-cylinder, turbocharged and after-cooled diesel engine with a common rail injection system using spiked fuels with different combinations of sulphur (S) and vanadium (V) spiking. The effect of fuel S content on both particle number (PN) and mass (PM) was clearly observed in this study. Higher PN and PM were observed for fuels with higher S contents at all engine load conditions. This study also found a correlation between fuel S content and nucleation mode particle number concentration which have more harmful impact on human health than larger particles. The highest PN and PM were observed at partial load conditions. In addition, S in fuel resulted in higher viscosity of spiked fuels, which led to lower engine blow-by. Fuel V content was observed in this study, evidencing that it had no clear effect on engine performance and emissions. Increased engine load also resulted in higher engine blow-by. The lower peak of in-cylinder pressure observed at both pre-mixed and diffusion combustion phases with the spiked fuels may be associated with the lower energy content in the fuel blends compared to diesel fuel.

Observations on the formation, growth and chemical composition of aerosols in an urban environment

Publisher: American Chemical Society (ACS)

Date: 05-06-2014

DOI: 10.1021/ES5019509

Abstract: The charge and chemical composition of ambient particles in an urban environment were determined using a neutral particle and air ion spectrometer and an aerodyne compact time-of-flight aerosol mass spectrometer. Particle formation and growth events were observed on 20 of the 36 days of s ling, with eight of these events classified as strong. During these events, peaks in the concentration of intermediate and large ions were followed by peaks in the concentration of ammonium and sulfate, which were not observed in the organic fraction. Comparison of days with and without particle formation events revealed that ammonium and sulfate were the dominant species on particle formation days while high concentrations of biomass burning OA inhibited particle growth. Analyses of the degree of particle neutralization lead us to conclude that an excess of ammonium enabled particle formation and growth. In addition, the large ion concentration increased sharply during particle growth, suggesting that during nucleation the neutral gaseous species ammonia and sulfuric acid react to form ammonium and sulfate ions. Overall, we conclude that the mechanism of particle formation and growth involved ammonia and sulfuric acid, with limited input from organics.

Photoacoustic frequency heat-transmission technique: Thermal and carrier transport parameters measurements in silicon

Publisher: AIP Publishing

Date: 11-1995

DOI: 10.1063/1.359637

Abstract: Photoacoustic frequency heat-transmission technique is used to study thermal and carrier transport properties in low-doped silicon wafers. Amplitude and phase photoacoustic signals as a function of modulation frequency of incident optical beam are measured using different experimental conditions. The thermal diffusivity, coefficient of excess carrier diffusion, carrier lifetime, and the surface recombination velocity were determined by comparing experimental results and calculated theoretical photoacoustic signals. The suitability of the photoacoustic frequency heat-transmission technique as a contactless diagnostic method is assessed in comparison with the more conventional photothermal deflection and photothermal modulated reflection techniques.

Impact of COVID-19 on Cardiovascular Testing in the United States Versus the Rest of the World

Publisher: Elsevier BV

Date: 09-2021

DOI: 10.1016/J.JCMG.2021.03.007

The effect of diesel emission exposure on intracellular signaling pathways of primary human bronchial epithelial cells

Publisher: European Respiratory Society

Date: 09-2017

DOI: 10.1183/1393003.CONGRESS-2017.PA4458

Analysis of cold-start NO2 and NOx emissions, and the NO2/NOx ratio in a diesel engine powered with different diesel-biodiesel blends

Publisher: Elsevier BV

Date: 12-2021

DOI: 10.1016/J.ENVPOL.2021.118052

Hygroscopic and Volatile Properties of Ultrafine Particles in the Eucalypt Forests: Comparison with Chamber Experiments and the Role of Sulphates in New Particle Formation

Publisher: Springer Netherlands

Date: 2007

DOI: 10.1007/978-1-4020-6475-3_135

Marine productivity and synoptic meteorology drive summer-time variability in Southern Ocean aerosols

Publisher: Copernicus GmbH

Date: 27-11-2019

DOI: 10.5194/ACP-2019-1081

Abstract: Abstract. Cloud-radiation interactions over the Southern Ocean are not well constrained in climate models, in part due to uncertainties in the sources, concentrations and cloud-forming potential of aerosol in this region. To date, most studies in this region have reported measurements from fixed terrestrial stations or a limited set of instrumentation, and often present findings as broad seasonal or latitudinal trends. Here, we present an extensive set of aerosol and meteorological observations obtained during an austral summer cruise across the full width of the Southern Ocean south of Australia. Three episodes of continental-influenced air masses were identified, including an apparent transition between the Ferrel atmospheric cell and the polar cell at approximately 64° S. During the other two episodes, synoptic-scale weather patterns erted air masses across distances greater than 1000 km from the Australian and Antarctic coastlines, respectively, indicating that a large proportion of the Southern Ocean may be periodically influenced by continental air masses. In all three cases, a highly cloud-active accumulation mode dominated the size distribution, with up to 93 % of the total number concentration activating as cloud condensation nuclei. In contrast, s ling periods influenced by marine air masses frequently demonstrated a correlation between air mass trajectories over regions of high biological productivity and subsequent enhancement of an Aitken mode centred at approximately 30 nm and contributing an average of 71 % of the total aerosol number concentration. Although these small diameters limited their contribution to cloud condensation nuclei concentrations, Aitken number concentrations and diameters were highly variable. A detailed investigation of the marine air masses revealed that this variability may be attributed to the availability of biogenic precursors, the competing influence of condensation sinks (such as sea spray aerosol) and vertical transport between the marine boundary layer and the free troposphere. This variability of the marine Aitken mode as well as the instances of long-range transport were governed by synoptic-scale weather systems, through their influence on air mass trajectories and both generation and depletion of condensation sinks. These results demonstrate the highly dynamic nature of Southern Ocean aerosol and their complex dependence on both biological productivity and synoptic-scale weather systems.

Assessment of the use of a novel series of oxygenated fuels for a turbocharged diesel engine

Publisher: Elsevier BV

Date: 04-2019

DOI: 10.1016/J.JCLEPRO.2019.01.249

Performance evaluation of non-thermal plasma on particulate matter, ozone and CO2 correlation for diesel exhaust emission reduction

Publisher: Elsevier BV

Date: 09-2015

DOI: 10.1016/J.CEJ.2015.04.086

The effects of fuel characteristics and engine operating conditions on the elemental composition of emissions from heavy duty diesel buses

Publisher: Elsevier BV

Date: 08-2007

DOI: 10.1016/J.FUEL.2006.11.025

Hygroscopic behavior of partially volatilized coastal marine aerosols using the volatilization and humidification tandem differential mobility analyzer technique

Publisher: American Geophysical Union (AGU)

Date: 25-10-2005

DOI: 10.1029/2004JD005657

Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

Publisher: Copernicus GmbH

Date: 12-01-2015

DOI: 10.5194/ACP-15-223-2015

Abstract: Abstract. The dicarbonyls glyoxal and methylglyoxal have been measured with 2,4-dinitrophenylhydrazine (2,4-DNPH) cartridges and high-performance liquid chromatography (HPLC), optimised for dicarbonyl detection, in clean marine air over the temperate Southern Hemisphere (SH) oceans. Measurements of a range of dicarbonyl precursors (volatile organic compounds, VOCs) were made in parallel. These are the first in situ measurements of glyoxal and methylglyoxal over the remote temperate oceans. Six 24 h s les were collected in summer (February–March) over the Chatham Rise in the south-west Pacific Ocean during the Surface Ocean Aerosol Production (SOAP) voyage in 2012, while 34 24 h s les were collected at Cape Grim Baseline Air Pollution Station in the late winter (August–September) of 2011. Average glyoxal mixing ratios in clean marine air were 7 ppt at Cape Grim and 23 ppt over Chatham Rise. Average methylglyoxal mixing ratios in clean marine air were 28 ppt at Cape Grim and 10 ppt over Chatham Rise. The mixing ratios of glyoxal at Cape Grim are the lowest observed over the remote oceans, while mixing ratios over Chatham Rise are in good agreement with other temperate and tropical observations, including concurrent Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations. Methylglyoxal mixing ratios at both sites are comparable to the only other marine methylglyoxal observations available over the tropical Northern Hemisphere (NH) ocean. Ratios of glyoxal : methylglyoxal 1 over Chatham Rise but 1 at Cape Grim suggest that a different formation and/or loss processes or rates dominate at each site. Dicarbonyl precursor VOCs, including isoprene and monoterpenes, are used to calculate an upper-estimate yield of glyoxal and methylglyoxal in the remote marine boundary layer and explain at most 1–3 ppt of dicarbonyls observed, corresponding to 10% and 17% of the observed glyoxal and 29 and 10% of the methylglyoxal at Chatham Rise and Cape Grim, respectively, highlighting a significant but as yet unknown production mechanism. Surface-level glyoxal observations from both sites were converted to vertical columns and compared to average vertical column densities (VCDs) from GOME-2 satellite retrievals. Both satellite columns and in situ observations are higher in summer than winter however, satellite vertical column densities exceeded the surface observations by more than 1.5 × 1014 molecules cm−2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or it may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption or the use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much-needed data to verify the presence of these short-lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

Hygroscopic and volatile properties of marine aerosol observed at Cape Grim during the P2P campaign

Publisher: CSIRO Publishing

Date: 2007

DOI: 10.1071/EN07011

Abstract: Environmental context. The marine environment covers 71% of the Earth’s surface, and accounts for most of the planet’s cloud cover. Water droplets in these clouds all form on pre-existing marine aerosol particles. The number, size and composition of these particles determine the cloud droplet size and consequently, the cloud’s light scattering and precipitation behaviour. Marine aerosols, therefore, have a major influence on the planet’s radiation balance and climate. The origin of marine aerosols is still not completely resolved. The newly developed VH-TDMA technique has been applied to marine aerosols that come from the Southern Ocean. The technique enabled new insights into the composition and structure of these aerosols. It has been found that organic matter constitutes 20–40% of these particles, which suppresses their hygroscopic growth. Abstract. Simultaneous measurement of particle hygroscopic and volatile properties was performed using a VH-TDMA on both Aitken and accumulation mode particles. In addition, deliquescence measurements at different thermodenuder temperatures were also performed. The measurements were part of the P2P c aign which took place in February 2006 at the Cape Grim monitoring station in Tasmania, Australia. During baseline conditions, there was often a volatilisation step that occurred below 125°C in the volatility scans, where up to 25% of the volume is lost. Analysis of the changes in growth as this took place indicates that different substances are responsible for this volatilisation on different days – ammonium nitrate, sulfuric acid, or a volatile non-hygroscopic organic. The major volatilisation in all cases occurred in the temperature range ~140–200°C, which is taken to indicate the presence of ammonium sulfate or ammonium bisulfate. A degree of growth suppression is generally evident before this volatilisation, which indicates that a non-hygroscopic material with a similar volatility to ammonium sulfate/bisulfate may be present, which cannot be distinguished in the volatility scans. Organic matter was typically present at around ~20–40% for these particles. When Aitken and accumulation mode particles were measured on the same day, it was found that the organic content of the smaller particles tended to be higher than the larger particles by roughly 20 percentage points.

Engine performance and emissions of high nitrogen-containing fuels

Publisher: Elsevier BV

Date: 03-2020

DOI: 10.1016/J.FUEL.2019.116805

Modeling Indoor Particulate Matter and Small Ion Concentration Relationship—A Comparison of a Balance Equation Approach and Data Driven Approach

Publisher: MDPI AG

Date: 27-08-2020

DOI: 10.3390/APP10175939

Abstract: In this work we explore the relationship between particulate matter (PM) and small ion (SI) concentration in a typical indoor elementary school environment. A range of important air quality parameters (radon, PM, SI, temperature, humidity) were measured in two elementary schools located in urban background and suburban area in Belgrade city, Serbia. We focus on an interplay between concentrations of radon, small ions (SI) and particulate matter (PM) and for this purpose, we utilize two approaches. The first approach is based on a balance equation which is used to derive approximate relation between concentration of small ions and particulate matter. The form of the obtained relation suggests physics based linear regression modelling. The second approach is more data driven and utilizes machine learning techniques, and in this approach, we develop a more complex statistical model. This paper attempts to put together these two methods into a practical statistical modelling approach that would be more useful than either approach alone. The artificial neural network model enabled prediction of small ion concentration based on radon and particulate matter measurements. Models achieved median absolute error of about 40 ions/cm3 and explained variance of about 0.7. This could potentially enable more simple measurement c aigns, where a smaller number of parameters would be measured, but still allowing for similar insights.

Restructuring of carbonaceous particles upon exposure to organic and water vapours

Publisher: Elsevier BV

Date: 05-2012

DOI: 10.1016/J.JAEROSCI.2011.12.005

Particle emissions from biodiesels with different physical properties and chemical composition

Publisher: Elsevier BV

Date: 10-2014

DOI: 10.1016/J.FUEL.2014.05.053

Emissions and performance with diesel and waste lubricating oil: A fundamental study into cold start operation with a special focus on particle number size distribution

Publisher: Elsevier BV

Date: 04-2020

DOI: 10.1016/J.ENCONMAN.2020.112604

The contribution of coral-reef-derived dimethyl sulfide to aerosol burden over the Great Barrier Reef

Publisher: Copernicus GmbH

Date: 22-02-2022

DOI: 10.5194/ACP-22-2419-2022

Abstract: Abstract. Coral reefs have been found to produce the sulfur compound dimethyl sulfide (DMS), a climatically relevant aerosol precursor predominantly associated with phytoplankton. Until recently, the role of coral-reef-derived DMS within the climate system had not been quantified. A study preceding the present work found that DMS produced by corals had negligible long-term climatic forcing at the global–regional scale. However, at sub-daily timescales more typically associated with aerosol and cloud formation, the influence of coral-reef-derived DMS on local aerosol radiative effects remains unquantified. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) has been used in this work to study the role of coral-reef-derived DMS at sub-daily timescales for the first time. WRF-Chem was run to coincide with an October 2016 field c aign over the Great Barrier Reef, Queensland, Australia, against which the model was evaluated. After updating and scaling the DMS surface water climatology, the model reproduced DMS and sulfur concentrations well. The inclusion of coral-reef-derived DMS resulted in no significant change in sulfate aerosol mass or total aerosol number. Subsequently, no direct or indirect aerosol effects were detected. The results suggest that the co-location of the Great Barrier Reef with significant anthropogenic aerosol sources along the Queensland coast prevents coral-reef-derived aerosol from having a modulating influence on local aerosol burdens in the current climate.

Influence of oxygenated organic aerosols (OOAs) on the oxidative potential of diesel and biodiesel particulate matter

Publisher: American Chemical Society (ACS)

Date: 26-06-2013

DOI: 10.1021/ES4007433

Abstract: Generally, the magnitude of pollutant emissions from diesel engines running on biodiesel fuel is ultimately coupled to the structure of the fuel's constituent molecules. Previous studies demonstrated the relationship between the organic fraction of particulate matter (PM) and its oxidative potential. Herein, emissions from a diesel engine running on different biofuels were analyzed in more detail to explore the role that different organic fractions play in the measured oxidative potential. In this work, a more detailed chemical analysis of biofuel PM was undertaken using a compact time of flight aerosol mass spectrometer (c-ToF AMS). This enabled a better identification of the different organic fractions that contribute to the overall measured oxidative potentials. The concentration of reactive oxygen species (ROS) was measured using a profluorescent nitroxide molecular probe 9-(1,1,3,3-tetramethylisoindolin-2-yloxyl-5-ethynyl)-10-(phenylethynyl)anthracene (BPEAnit). Therefore, the oxidative potential of the PM, measured through the ROS content, although proportional to the total organic content in certain cases, shows a much higher correlation with the oxygenated organic fraction as measured by the c-ToF AMS. This highlights the importance of knowing the surface chemistry of particles for assessing their health impacts. It also sheds light onto new aspects of particulate emissions that should be taken into account when establishing relevant metrics for assessing health implications of replacing diesel with alternative fuels.

Effect of Oxygenated Functional Groups in Essential Oils on Diesel Engine Performance, Emissions, and Combustion Characteristics

Publisher: American Chemical Society (ACS)

Date: 09-09-2019

DOI: 10.1021/ACS.ENERGYFUELS.9B01604

Particle emissions from microalgae biodiesel combustion and their relative oxidative potential

Publisher: Royal Society of Chemistry (RSC)

Date: 2015

DOI: 10.1039/C5EM00125K

Abstract: Microalgae are considered to be one of the most viable biodiesel feedstocks for the future due to their potential for providing sustainable and cleaner alternatives to petroleum diesel.

Relation between particle mass and number for submicrometer airborne particles

Publisher: Elsevier BV

Date: 06-1999

DOI: 10.1016/S1352-2310(98)00433-6

Characteristics of Particle Number and Particle Mass Emissions of a Diesel Engine during Cold-, Warm-, and Hot-Start Operation

Publisher: SAE International

Date: 02-06-2021

DOI: 10.4271/2021-01-5061

Diesel engine emissions with oxygenated fuels: A comparative study into cold-start and hot-start operation

Publisher: Elsevier BV

Date: 09-2017

DOI: 10.1016/J.JCLEPRO.2017.06.052

Effect of atmospheric aging on volatility and reactive oxygen species of biodiesel exhaust nano-particles

Publisher: Copernicus GmbH

Date: 17-08-2015

DOI: 10.5194/ACP-15-9099-2015

Abstract: Abstract. In the prospect of limited energy resources and climate change, effects of alternative biofuels on primary emissions are being extensively studied. Our two recent studies have shown that biodiesel fuel composition has a significant impact on primary particulate matter emissions. It was also shown that particulate matter caused by biodiesels was substantially different from the emissions due to petroleum diesel. Emissions appeared to have higher oxidative potential with the increase in oxygen content and decrease of carbon chain length and unsaturation levels of fuel molecules. Overall, both studies concluded that chemical composition of biodiesel is more important than its physical properties in controlling exhaust particle emissions. This suggests that the atmospheric aging processes, including secondary organic aerosol formation, of emissions from different fuels will be different as well. In this study, measurements were conducted on a modern common-rail diesel engine. To get more information on realistic properties of tested biodiesel particulate matter once they are released into the atmosphere, particulate matter was exposed to atmospheric oxidants, ozone and ultra-violet light and the change in their properties was monitored for different biodiesel blends. Upon the exposure to oxidative agents, the chemical composition of the exhaust changes. It triggers the cascade of photochemical reactions resulting in the partitioning of semi-volatile compounds between the gas and particulate phase. In most of the cases, aging lead to the increase in volatility and oxidative potential, and the increment of change was mainly dependent on the chemical composition of fuels as the leading cause for the amount and the type of semi-volatile compounds present in the exhaust.

Energy and chemical conversion of five Australian lignocellulosic feedstocks into bio-crude through liquefaction

Publisher: Royal Society of Chemistry (RSC)

Date: 2017

DOI: 10.1039/C7RA02335A

Abstract: Thermal liquefaction of five potential feedstocks namely, banana bunch stems (BBS), pineapple tops (PT), Forage sorghum (FS), bagasse (Ba) and Arundo donax (AD) were examined from an energy perspective at a large laboratory scale.

Gaseous and particulate emissions analysis using microalgae based dioctyl phthalate biofuel during cold, warm and hot engine operation

Publisher: Elsevier BV

Date: 03-2022

DOI: 10.1016/J.FUEL.2021.122965

Particle and gaseous emissions from compressed natural gas and ultralow sulphur diesel-fuelled buses at four steady engine loads

Publisher: Elsevier BV

Date: 04-2009

DOI: 10.1016/J.SCITOTENV.2009.01.001

Abstract: Exhaust emissions from thirteen compressed natural gas (CNG) and nine ultralow sulphur diesel in-service transport buses were monitored on a chassis dynamometer. Measurements were carried out at idle and at three steady engine loads of 25%, 50% and 100% of maximum power at a fixed speed of 60 km h(-1). Emission factors were estimated for particle mass and number, carbon dioxide and oxides of nitrogen for two types of CNG buses (Scania and MAN, compatible with Euro 2 and 3 emission standards, respectively) and two types of diesel buses (Volvo Pre-Euro/Euro1 and Mercedez OC500 Euro3). All emission factors increased with load. The median particle mass emission factor for the CNG buses was less than 1% of that from the diesel buses at all loads. However, the particle number emission factors did not show a statistically significant difference between buses operating on the two types of fuel. In this paper, for the very first time, particle number emission factors are presented at four steady state engine loads for CNG buses. Median values ranged from the order of 10(12) particles min(-)(1) at idle to 10(15) particles km(-)(1) at full power. Most of the particles observed in the CNG emissions were in the nanoparticle size range and likely to be composed of volatile organic compounds The CO2 emission factors were about 20% to 30% greater for the diesel buses over the CNG buses, while the oxides of nitrogen emission factors did not show any difference due to the large variation between buses.

Submicrometer and supermicrometer particulate emission from spark ignition vehicles

Publisher: American Chemical Society (ACS)

Date: 29-10-1998

DOI: 10.1021/ES980102D

Real-time measurement of bacterial aerosols with the UVAPS: Performance evaluation

Publisher: Elsevier BV

Date: 03-2003

DOI: 10.1016/S0021-8502(02)00181-7

Measurements of oxidative potential of particulate matter at belgrade tunnel; comparison of BPEAnit, DTT and DCFH assays

Publisher: MDPI AG

Date: 05-12-2019

DOI: 10.3390/IJERPH16244906

Abstract: To estimate the oxidative potential (OP) of particulate matter (PM), two commonly used cell-free, molecular probes were applied: dithiothreitol (DTT) and dichloro-dihydro-fluorescein diacetate (DCFH-DA), and their performance was compared with 9,10-bis (phenylethynyl) anthracene-nitroxide (BPEAnit). To the best of our knowledge, this is the first study in which the performance of the DTT and DCFH has been compared with the BPEAnit probe. The average concentrations of PM, organic carbon (OC) and elemental carbon (EC) for fine (PM2.5) and coarse (PM10) particles were determined. The results were 44.8 ± 13.7, 9.8 ± 5.1 and 9.3 ± 4.8 µg·m−3 for PM2.5 and 75.5 ± 25.1, 16.3 ± 8.7 and 11.8 ± 5.3 µg·m−3 for PM10, respectively, for PM, OC and EC. The water-soluble organic carbon (WSOC) fraction accounted for 42 ± 14% and 28 ± 9% of organic carbon in PM2.5 and PM10, respectively. The average volume normalized OP values for the three assays depended on both the s ling periods and the PM fractions. The OPBPEAnit had its peak at 2 p.m. in the afternoon, it was three times higher compared to the morning and late afternoon values. The DCFH and BPEAnit results were correlated (r = 0.64), while there was no good agreement between the BPEAnit and the DTT (r = 0.14). The total organic content of PM does not necessarily represent oxidative capacity and it shows varying correlation with the OP. With respect to the two PM fractions studied, the OP was mostly associated with smaller particles.

Engine performance and emissions from fuels containing nitrogen and sulphur

Publisher: Elsevier BV

Date: 05-2022

DOI: 10.1016/J.ECMX.2022.100179

Characterisation of the impact of open biomass burning on urban air quality in Brisbane, Australia

Publisher: Elsevier BV

Date: 05-2016

DOI: 10.1016/J.ENVINT.2016.02.030

Abstract: Open biomass burning from wildfires and the prescribed burning of forests and farmland is a frequent occurrence in South-East Queensland (SEQ), Australia. This work reports on data collected from 10 to 30 September 2011, which covers the days before (10-14 September), during (15-20 September) and after (21-30 September) a period of biomass burning in SEQ. The aim of this project was to comprehensively quantify the impact of the biomass burning on air quality in Brisbane, the capital city of Queensland. A multi-parameter field measurement c aign was conducted and ambient air quality data from 13 monitoring stations across SEQ were analysed. During the burning period, the average concentrations of all measured pollutants increased (from 20% to 430%) compared to the non-burning period (both before and after burning), except for total xylenes. The average concentration of O3, NO2, SO2, benzene, formaldehyde, PM10, PM2.5 and visibility-reducing particles reached their highest levels for the year, which were up to 10 times higher than annual average levels, while PM10, PM2.5 and SO2 concentrations exceeded the WHO 24-hour guidelines and O3 concentration exceeded the WHO maximum 8-hour average threshold during the burning period. Overall spatial variations showed that all measured pollutants, with the exception of O3, were closer to spatial homogeneity during the burning compared to the non-burning period. In addition to the above, elevated concentrations of three biomass burning organic tracers (levoglucosan, mannosan and galactosan), together with the amount of non-refractory organic particles (PM1) and the average value of f60 (attributed to levoglucosan), reinforce that elevated pollutant concentration levels were due to emissions from open biomass burning events, 70% of which were prescribed burning events. This study, which is the first and most comprehensive of its kind in Australia, provides quantitative evidence of the significant impact of open biomass burning events, especially prescribed burning, on urban air quality. The current results provide a solid platform for more detailed health and modelling investigations in the future.

A nested real-time PCR assay has an increased sensitivity suitable for detection of viruses in aerosol studies

Publisher: Oxford University Press (OUP)

Date: 05-2009

DOI: 10.1111/J.1365-2672.2008.04119.X

Abstract: Influenza is commonly spread by infectious aerosols however, detection of viruses in aerosols is not sensitive enough to confirm the characteristics of virus aerosols. The aim of this study was to develop an assay for respiratory viruses sufficiently sensitive to be used in epidemiological studies. A two-step, nested real-time PCR assay was developed for MS2 bacteriophage, and for influenza A and B, parainfluenza 1 and human respiratory syncytial virus. Outer primer pairs were designed to nest each existing real-time PCR assay. The sensitivities of the nested real-time PCR assays were compared to those of existing real-time PCR assays. Both assays were applied in an aerosol study to compare their detection limits in air s les. The nested real-time PCR assays were found to be several logs more sensitive than the real-time PCR assays, with lower levels of virus detected at lower Ct values. The nested real-time PCR assay successfully detected MS2 in air s les, whereas the real-time assay did not. The sensitive assays for respiratory viruses will permit further research using air s les from naturally generated virus aerosols. This will inform current knowledge regarding the risks associated with the spread of viruses through aerosol transmission.

Characterization of the particle emission from a ship operating at sea using an unmanned aerial vehicle

Publisher: Copernicus GmbH

Date: 31-01-2019

DOI: 10.5194/AMT-12-691-2019

Abstract: Abstract. This research demonstrates the use of an unmanned aerial vehicle (UAV) to characterize the gaseous (CO2) and particle (10–500 nm) emissions of a ship at sea. The field study was part of the research voyage “The Great Barrier Reef as a significant source of climatically relevant aerosol particles” on board the RV Investigator around the Australian Great Barrier Reef. Measurements of the RV Investigator exhaust plume were carried out while the ship was operating at sea, at a steady engine load of 30 %. The UAV system was flown autonomously using several different programmed paths. These incorporated different altitudes and distances behind the ship in order to investigate the optimal position to capture the ship plume. Five flights were performed, providing a total of 27 horizontal transects perpendicular to the ship exhaust plume. Results show that the most appropriate altitude and distance to effectively capture the plume was 25 m a.s.l. and 20 m downwind. Particle number emission factors (EFPNs) were calculated in terms of number of particles emitted (no.) per weight of fuel consumed (kgfuel). Fuel consumption was calculated using the simultaneous measurements of plume CO2 concentration. The calculated EFPN was 7.6±1.4×1015no. kgfuel-1 which is in line with those reported in the literature for ship emissions ranging from 0.2 to 6.2×1016 no. kgfuel-1. This UAV system successfully assessed ship emissions to derive EFPN under real world conditions. This is significant as it provides a novel, relatively inexpensive and accessible way to assess ship EFPN at sea.

A robust, portable H-TDMA for field use

Publisher: Elsevier BV

Date: 10-2008

DOI: 10.1016/J.JAEROSCI.2008.05.005

Source apportionment of oxidative potential: What we know so far

Publisher: National Library of Serbia

Date: 2023

DOI: 10.2298/TSCI221107111S

Abstract: In numerous epidemiological studies, exposure to particulate matter (PM) has been associated with negative health outcomes. It has been established so far that the detrimental health effects of particles cannot be explained by a single parameter, such as particle mass, as the complexity of chemical composition and reactivity of particles are not always represented by the mass loadings. The oxidative potential (OP) of aerosol particles represents a promising indicator of their potential toxicity. To develop strategies and regulations at improving the air quality, an increasing number of studies are focused on the application of source apportionment (SA) of PM., while a limited number of SA investigations have been applied to OP. In this review previous research of SA of atmospheric PM OP and proposed guidelines for future studies are summarized. Most of the research studies were carried out in an urban area and focused on PM2.5, while few studies examined other PM fractions. It was noted that the three dominant contributors to OP were biomass burning (9-97%), secondary aerosols (6-67%), and traffic/vehicles (16-88%). The presence of other factors that contributed to the in-crease of OP to a lesser extent depended on the location and season. Further, a considerable discrepancy in the contribution of various OP vs. PM sources was discovered using SA models. Because of this, the use of SA is not equivalent when considering the mass of PM and its toxicity.

Low-cost PM2.5 Sensors: An Assessment of Their Suitability for Various Applications

Publisher: Taiwan Association for Aerosol Research

Date: 2020

DOI: 10.4209/AAQR.2018.10.0390

A new oxidation flow reactor for the measurements of secondary aerosol formation: Characterisation and a case study

Publisher: Elsevier BV

Date: 09-2023

DOI: 10.1016/J.ATMOSENV.2023.119886

Reductions in diesel emissions including PM and PN emissions with diesel-biodiesel blends

Publisher: Elsevier BV

Date: 11-2017

DOI: 10.1016/J.JCLEPRO.2017.08.096

Photoacoustic investigation of transport in semiconductors: Theoretical and experimental study of a Ge single crystal

Publisher: American Physical Society (APS)

Date: 15-05-1995

DOI: 10.1103/PHYSREVB.51.14226

Influence of different alternative fuels on particle emission from a turbocharged common-rail Diesel engine

Publisher: Elsevier BV

Date: 2013

DOI: 10.1016/J.PROENG.2013.03.136

Hazardous particles during diesel engine cold-start and warm-up

Publisher: Elsevier BV

Date: 10-2023

DOI: 10.1016/J.JHAZMAT.2023.132516

Performance Evaluation of the UVAPS: Influence of Physiological Age of Airborne Bacteria and Bacterial Stress

Publisher: Elsevier BV

Date: 12-2003

DOI: 10.1016/S0021-8502(03)00191-5

Nanomechanics and morphology of simulated respiratory particles

Publisher: American Chemical Society (ACS)

Date: 24-02-2022

DOI: 10.26434/CHEMRXIV-2022-3Z6S7

Abstract: The impact of respiratory particle composition on the equilibrium morphology and phase are not well understood. Furthermore, the effects of these different phases and morphologies on the viability of viruses embedded within these particles are equally unknown. Physiologically relevant respiratory fluid analogues were constructed, and their hygroscopic behavior were measured using an ensemble technique. A relationship between hygroscopicity and protein concentration was determined, providing additional validation to the high protein content of respiratory aerosol measured in prior works ( %). Atomic force microscopy was used to probe the viscoelasticity of deposited protein particles, and transmission electron microscopy was used to observe the morphology of dried composite protein/salt particles. It was found that dried protein particles at indoor-relevant climatic conditions could exist separately in a glassy or viscous semisolid state. A glassy protein shell could kinetically ‘freeze’ a particle at conditions more favorable for virus viability.

Whole-genome sequencing reveals transmission of gonococcal antibiotic resistance among men who have sex with men: An observational study

Publisher: BMJ

Date: 15-12-2018

DOI: 10.1136/SEXTRANS-2017-053287

Abstract: Drug-resistant Neisseria gonorrhoeae are now a global public health threat. Direct transmission of antibiotic-resistant gonococci between in iduals has been proposed as a driver for the increased transmission of resistance, but direct evidence of such transmission is limited. Whole-genome sequencing (WGS) has superior resolution to investigate outbreaks and disease transmission compared with traditional molecular typing methods such as multilocus sequence typing (MLST) and N. gonorrhoeae multiantigen sequence (NG-MAST). We therefore aimed to systematically investigate the transmission of N. gonorrhoeae between men in sexual partnerships using WGS to compare isolates and their resistance to antibiotics at a genome level. 458 couples from a large prospective cohort of men who have sex with men (MSM) tested for gonorrhoea together between 2005 and 2014 were included, and WGS was conducted on all isolates from couples where both men were culture-positive for N. gonorrhoeae . Resistance-determining sequences were identified from genome assemblies, and comparison of isolates between and within in iduals was performed by pairwise single nucleotide polymorphism and pangenome comparisons, and in silico predictions of NG-MAST and MLST. For 33 of 34 (97% 95% CI 85% to 100%) couples where both partners were positive for gonorrhoea, the resistance-determining genes and mutations were identical in isolates from each partner (94 isolates in total). Resistance determinants in isolates from 23 of 23 (100% 95% CI 86% to 100%) men with multisite infections were also identical within an in idual. These partner and within-host isolates were indistinguishable by NG-MAST, MLST and whole genomic comparisons. These data support the transmission of antibiotic-resistant strains between sexual partners as a key driver of resistance rates in gonorrhoea among MSM. This improved understanding of the transmission dynamics of N. gonorrhoeae between sexual partners will inform treatment and prevention guidelines.

An instrument for the rapid quantification of PM oxidative potential: the Particle Into Nitroxide Quencher (PINQ)

Publisher: Copernicus GmbH

Date: 05-11-2018

DOI: 10.5194/AMT-2018-333

Abstract: Abstract. Presence or generation of reactive oxygen species (ROS) on/by particulate matter (PM) have been implicated in PM-induced health effects. Methodologies to quantify ROS concentrations vary widely both in detection and collection methods. However, there is currently an increasing emphasis on rapid collection and measurement due to observations of short half-live ROS. To address this problem, this manuscript details the design and characterization of a novel instrument named the Particle Into Nitroxide Quencher (PINQ). This instrument combines the BPEAnit ROS assay in conjunction with a purpose-built aerosol collection device, the insoluble aerosol collector (IAC). The IAC continuously collects PM regardless of size or chemistry directly into a liquid s le with a collection efficiency of 0.98 and a low cut-off size of 20 nm. The s ling time resolution of the PINQ is one minute, with a limit of detection (LOD) of 0.08 nmol m−3 in equivalent BPEAnit-Me concentration per volume of air. This high s le time resolution and sensitivity is achieved due a combination of the highly concentrated IAC liquid s le and the rapid reaction and stability of the BPEAnit probe.

Cold-start NOx emissions

Publisher: Elsevier BV

Date: 02-2021

DOI: 10.1016/J.FUEL.2020.119430

The correlation between diesel soot chemical structure and reactivity

Publisher: Elsevier BV

Date: 05-2020

DOI: 10.1016/J.CARBON.2020.01.061

Experimental investigation of ultra-fine particle size distribution near a busy road

Publisher: Elsevier BV

Date: 04-2004

DOI: 10.1016/J.ATMOSENV.2003.12.028

Light absorption properties of black and brown carbon during the prescribed burning season at an urban background site in Brisbane, Australia

Publisher: Elsevier BV

Date: 11-2023

DOI: 10.1016/J.ATMOSENV.2023.120072

The contribution of coral reef-derived dimethyl sulfide to aerosol burden over the Great Barrier Reef: a modelling study

Publisher: Copernicus GmbH

Date: 29-07-2021

DOI: 10.5194/ACP-2021-507

Abstract: Abstract. Coral reefs have been found to produce the sulfur compound dimethyl sulfide (DMS), a climatically relevant aerosol precursor predominantly associated with phytoplankton. Until recently, the role of coral reef-derived DMS within the climate system had not been quantified. A study preceding the present work found that DMS produced by corals had negligible long-term climatic forcing at the global-regional scale. However, at sub-daily time scales more typically associated with aerosol and cloud formation, the influence of coral reef-derived DMS on local aerosol radiative effects remains unquantified. The Weather Research and Forecasting – chemistry model (WRF-Chem) has been used in this work to study the role of coral reef-derived DMS at sub-daily time scales for the first time. WRF-Chem was run to coincide with an October 2016 field c aign over the Great Barrier Reef, Queensland, Australia, against which the model was evaluated. After updating the DMS surface water climatology, the model reproduced DMS and sulfur concentrations well. The inclusion of coral reef-derived DMS resulted in no significant change in sulfate aerosol mass or total aerosol number. Subsequently, no direct or indirect aerosol effects were detected. The results suggest that the co-location of the Great Barrier Reef with significant anthropogenic aerosol sources along the Queensland coast prevents coral reef derived-aerosol from having a modulating influence on local aerosol burdens in the current climate.

Effect of fuel composition and engine operating conditions on polycyclic aromatic hydrocarbon emissions from a fleet of heavy-duty diesel buses

Publisher: Elsevier BV

Date: 28-10-2005

DOI: 10.1016/J.ATMOSENV.2005.09.019

A comparative study of the number and mass of fine particles emitted with diesel fuel and marine gas oil (MGO)

Publisher: Elsevier BV

Date: 09-2012

DOI: 10.1016/J.ATMOSENV.2012.04.039

Relationship between Atmospheric PM-Bound Reactive Oxygen Species, Their Half-Lives, and Regulated Pollutants: Investigation and Preliminary Model

Publisher: American Chemical Society (ACS)

Date: 18-03-2020

DOI: 10.1021/ACS.EST.9B06643

Quantification of Particle Number and Mass Emission Factors from Combustion of Queensland Trees

Publisher: American Chemical Society (ACS)

Date: 16-08-2006

DOI: 10.1021/ES0609497

Abstract: The quantification of particle emission factors under controlled laboratory conditions for burning of the following five common tree species found in South East Queensland forests has been studied: Spotted Gum (Corymbia citriodora), Blue Gum (Eucalyptus tereticornis), Bloodwood (Eucalyptus intermedia), Iron Bark (Eucalyptus crebra), and Stringybark (Eucalyptus umbra). The results of the study show that the particle number emission factors and PM2.5 mass emission factors depend on the type of tree and the burning rate. For fast burning conditions, the average particle number emission factors are in the range of 3.3-5.7 x 10(15) particles/kg for woods and 0.5-6.9 x 10(15) particles/kg for leaves and branches, and the PM2.5 emission factors are in the range of 140-210 mg/kg for woods and 450-4700 mg/kg for leaves and branches. For slow burning conditions, the average particle number emission factors are in the range of 2.8-44.8 x 10(13) particles/kg for woods and 0.5-9.3 x 10(13) particles/kg for leaves and branches, and the PM2.5 emissions factors are in the range of 120-480 mg/kg for woods and 3300-4900 mg/kg for leaves and branches.

Determining the link between hygroscopicity and composition for semi-volatile aerosol species

Publisher: Copernicus GmbH

Date: 24-07-2018

DOI: 10.5194/AMT-11-4361-2018

Abstract: Abstract. Internally and externally mixed aerosols present significant challenges in assessing the hygroscopicity of each aerosol component. This study presents a new s ling technique which uses differences in volatility to separate mixtures and directly examine their respective composition and hygroscopic contribution. A shared thermodenuder and unheated bypass line are continuously cycled between an aerosol mass spectrometer and a volatility and hygroscopicity tandem differential mobility analyser, allowing real-time comparative analysis of heated and unheated aerosol properties. Measurements have been taken of both chamber-generated secondary organic aerosol and coastal marine aerosol at Cape Grim, Australia, to investigate system performance under erse conditions. Despite rapidly changing aerosol properties and the need to restrict analysis to a narrow size range, the former experiment separated the hygroscopic influences of ammonium sulfate and two distinct organic components with similar oxygen to carbon ratios but different volatilities. Analysis of the marine aerosol revealed an external mixture of non-sea-salt sulfates and sea spray aerosol, which likely shared similar volatile fractions composed of sulfuric acid and a non-hygroscopic organic component.

Particle emissions, volatility, and toxicity from an ethanol fumigated compression ignition engine

Publisher: American Chemical Society (ACS)

Date: 08-12-2010

DOI: 10.1021/ES9021377

Abstract: Particle emissions, volatility, and the concentration of reactive oxygen species (ROS) were investigated for a pre-Euro I compression ignition engine to study the potential health impacts of employing ethanol fumigation technology. Engine testing was performed in two separate experimental c aigns with most testing performed at intermediate speed with four different load settings and various ethanol substitutions. A scanning mobility particle sizer (SMPS) was used to determine particle size distributions, a volatilization tandem differential mobility analyzer (V-TDMA) was used to explore particle volatility, and a new profluorescent nitroxide probe, BPEAnit, was used to investigate the potential toxicity of particles. The greatest particulate mass reduction was achieved with ethanol fumigation at full load, which contributed to the formation of a nucleation mode. Ethanol fumigation increased the volatility of particles by coating the particles with organic material or by making extra organic material available as an external mixture. In addition, the particle-related ROS concentrations increased with ethanol fumigation and were associated with the formation of a nucleation mode. The smaller particles, the increased volatility, and the increase in potential particle toxicity with ethanol fumigation may provide a substantial barrier for the uptake of fumigation technology using ethanol as a supplementary fuel.

Carbon dioxide emissions from diesel and compressed natural gas buses during acceleration

Publisher: Elsevier BV

Date: 07-2010

DOI: 10.1016/J.TRD.2010.03.005

The use of carbon dioxide as a tracer in the determination of particle number emissions from heavy-duty diesel vehicles

Publisher: Elsevier BV

Date: 11-2005

DOI: 10.1016/J.ATMOSENV.2005.07.060

Characterisation of a Commercially Available Thermodenuder and Diffusion Drier for Ultrafine Particles Losses

Publisher: Taiwan Association for Aerosol Research

Date: 2015

DOI: 10.4209/AAQR.2013.12.0355

Fungal spore fragmentation as a function of airflow rates and fungal generation methods

Publisher: Elsevier BV

Date: 08-2009

DOI: 10.1016/J.ATMOSENV.2009.04.043

Observations of Clouds, Aerosols, Precipitation, and Surface Radiation over the Southern Ocean: An Overview of CAPRICORN, MARCUS, MICRE, and SOCRATES

Publisher: American Meteorological Society

Date: 04-2021

DOI: 10.1175/BAMS-D-20-0132.1

Abstract: Weather and climate models are challenged by uncertainties and biases in simulating Southern Ocean (SO) radiative fluxes that trace to a poor understanding of cloud, aerosol, precipitation, and radiative processes, and their interactions. Projects between 2016 and 2018 used in situ probes, radar, lidar, and other instruments to make comprehensive measurements of thermodynamics, surface radiation, cloud, precipitation, aerosol, cloud condensation nuclei (CCN), and ice nucleating particles over the SO cold waters, and in ubiquitous liquid and mixed-phase clouds common to this pristine environment. Data including soundings were collected from the NSF–NCAR G-V aircraft flying north–south gradients south of Tasmania, at Macquarie Island, and on the R/V Investigator and RSV Aurora Australis . Synergistically these data characterize boundary layer and free troposphere environmental properties, and represent the most comprehensive data of this type available south of the oceanic polar front, in the cold sector of SO cyclones, and across seasons. Results show largely pristine environments with numerous small and few large aerosols above cloud, suggesting new particle formation and limited long-range transport from continents, high variability in CCN and cloud droplet concentrations, and ubiquitous supercooled water in thin, multilayered clouds, often with small-scale generating cells near cloud top. These observations demonstrate how cloud properties depend on aerosols while highlighting the importance of dynamics and turbulence that likely drive heterogeneity of cloud phase. Satellite retrievals confirmed low clouds were responsible for radiation biases. The combination of models and observations is examining how aerosols and meteorology couple to control SO water and energy budgets.

The organic fraction of bubble-generated, accumulation mode Sea Spray Aerosol (SSA)

Publisher: Copernicus GmbH

Date: 26-03-2010

DOI: 10.5194/ACP-10-2867-2010

Abstract: Abstract. Recent studies have detected a dominant accumulation mode (~100 nm) in the Sea Spray Aerosol (SSA) number distribution. There is evidence to suggest that particles in this mode are composed primarily of organics. To investigate this hypothesis we conducted experiments on NaCl, artificial SSA and natural SSA particles with a Volatility-Hygroscopicity-Tandem-Differential-Mobility-Analyser (VH-TDMA). NaCl particles were atomiser generated and a bubble generator was constructed to produce artificial and natural SSA particles. Natural seawater s les for use in the bubble generator were collected from biologically active, terrestrially-affected coastal water in Moreton Bay, Australia. Differences in the VH-TDMA-measured volatility curves of artificial and natural SSA particles were used to investigate and quantify the organic fraction of natural SSA particles. Hygroscopic Growth Factor (HGF) data, also obtained by the VH-TDMA, were used to confirm the conclusions drawn from the volatility data. Both datasets indicated that the organic fraction of our natural SSA particles evaporated in the VH-TDMA over the temperature range 170–200 °C. The organic volume fraction for 71–77 nm natural SSA particles was 8±6%. Organic volume fraction did not vary significantly with varying water residence time (40 s to 24 h) in the bubble generator or SSA particle diameter in the range 38–173 nm. At room temperature we measured shape- and Kelvin-corrected HGF at 90% RH of 2.46±0.02 for NaCl, 2.35±0.02 for artifical SSA and 2.26±0.02 for natural SSA particles. Overall, these results suggest that the natural accumulation mode SSA particles produced in these experiments contained only a minor organic fraction, which had little effect on hygroscopic growth. Our measurement of 8±6% is an order of magnitude below two previous measurements of the organic fraction in SSA particles of comparable sizes. We stress that our results were obtained using coastal seawater and they can't necessarily be applied on a regional or global ocean scale. Nevertheless, considering the order of magnitude discrepancy between this and previous studies, further research with independent measurement techniques and a variety of different seawaters is required to better quantify how much organic material is present in accumulation mode SSA.

Observation of sea‐salt fraction in sub‐100 nm diameter particles at Cape Grim

Publisher: American Geophysical Union (AGU)

Date: 04-03-2015

DOI: 10.1002/2014JD022601

Impact of driving style and traffic condition on emissions and fuel consumption during real-world transient operation

Publisher: Elsevier BV

Date: 07-2022

DOI: 10.1016/J.FUEL.2022.123874

New particle formation and growth at a remote, sub-tropical coastal location

Publisher: Copernicus GmbH

Date: 12-10-2009

DOI: 10.5194/ACP-9-7607-2009

Abstract: Abstract. A month-long intensive measurement c aign was conducted in March/April 2007 at Agnes Water, a remote coastal site just south of the Great Barrier Reef on the east coast of Australia. Particle and ion size distributions were continuously measured during the c aign. Coastal nucleation events were observed in clean, marine air masses coming from the south-east on 65% of the days. The events usually began at ~10:00 local time and lasted for 1–4 h. They were characterised by the appearance of a nucleation mode with a peak diameter of ~10 nm. The freshly nucleated particles grew within 1–4 h up to sizes of 20–50 nm. The events occurred when solar intensity was high (~1000 W m−2) and RH was low (~60%). Interestingly, the events were not related to tide height. The volatile and hygroscopic properties of freshly nucleated particles (17–22.5 nm), simultaneously measured with a volatility-hygroscopicity-tandem differential mobility analyser (VH-TDMA), were used to infer chemical composition. The majority of the volume of these particles was attributed to internally mixed sulphate and organic components. After ruling out coagulation as a source of significant particle growth, we conclude that the condensation of sulphate and/or organic vapours was most likely responsible for driving particle growth at sizes greater than 10 nm during the nucleation events. Although there was a possibility that the precursor vapours responsible for particle formation and growth had continental sources, on the balance of available data we would suggest that the precursors were most likely of marine/coastal origin. Furthermore, a unique and particularly strong nucleation event was observed during northerly wind. The event began early one morning (08:00) and lasted almost the entire day resulting in the production of a large number of ~80 nm particles (average modal concentration during the event was 3200 cm−3). The Great Barrier Reef was the most likely source of precursor vapours responsible for this event.

On the efficiency of impingers with fritted nozzle tip for collection of ultrafine particles

Publisher: Elsevier BV

Date: 02-2009

DOI: 10.1016/J.ATMOSENV.2008.12.001

An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives

Publisher: MDPI AG

Date: 12-07-2016

DOI: 10.3390/S16071072

Optimisation of driving-parameters and emissions of a diesel-vehicle using principal component analysis (PCA)

Publisher: The University of Queensland

Date: 11-12-2020

DOI: 10.14264/EECCC3F

Application of a Fluorescent Probe for the Online Measurement of PM-Bound Reactive Oxygen Species in Chamber and Ambient Studies

Publisher: MDPI AG

Date: 21-10-2019

DOI: 10.3390/S19204564

Abstract: This manuscript details the application of a profluorescent nitroxide (PFN) for the online quantification of radical concentrations on particulate matter (PM) using an improved Particle Into Nitroxide Quencher (PINQ). A miniature flow-through fluorimeter developed specifically for use with the 9,10-bis(phenylethynyl)anthracene-nitroxide (BPEAnit) probe was integrated into the PINQ, along with automated gas phase corrections through periodic high efficiency particle arrestor (HEPA) filtering. The resulting instrument is capable of unattended s ling and was operated with a minimum time resolution of 2.5 min. Details of the fluorimeter design and ex les of data processing are provided, and results from a chamber study of side-stream cigarette smoke and ambient monitoring c aign in Guangzhou, China are presented. Primary cigarette smoke was shown to have both short-lived (t1/2 = 27 min) and long-lived (t1/2 = indefinite) PM-bound reactive oxygen species (ROS) components which had previously only been observed in secondary organic aerosol (SOA).

The cytotoxic, inflammatory and oxidative potential of coconut oil-substituted diesel emissions on bronchial epithelial cells at an air-liquid interface.

Publisher: Springer Science and Business Media LLC

Date: 24-07-2019

DOI: 10.1007/S11356-019-05959-5

Abstract: Diesel emissions contain high levels of particulate matter (PM) which can have a severe effect on the airways. Diesel PM can be effectively reduced with the substitution of diesel fuel with a biofuel such as vegetable oil. Unfortunately, very little is known about the cellular effects of these alternative diesel emissions on the airways. The aim of this study was to test whether coconut oil substitution in diesel fuel reduces the adverse effect of diesel emission exposure on human bronchial epithelial cells. Human bronchial epithelial cells were cultured at air-liquid interface for 7 days and exposed to diesel engine emissions from conventional diesel fuel or diesel fuel blended with raw coconut oil at low (10%), moderate (15%) and high (20%) proportions. Cell viability, inflammation, antioxidant production and xenobiotic metabolism were measured. Compared to conventional diesel, low fractional coconut oil substitution (10% and 15%) reduced inflammation and increased antioxidant expression, whereas higher fractional coconut oil (20%) reduced cell viability and increased inflammation. Therefore, cellular responses after exposure to alternative diesel emission are dependent on fuel composition.

Engine performance characteristics using microalgae derived dioctyl phthalate biofuel during cold, preheated and hot engine operation

Publisher: Elsevier BV

Date: 07-2023

DOI: 10.1016/J.FUEL.2023.128162

Particle Number Emissions and Source Signatures of an Industrial Facility

Publisher: American Chemical Society (ACS)

Date: 16-12-2005

DOI: 10.1021/ES048337E

Abstract: The work presented was conducted within the scope of a larger study investigating impacts of the Stuart Oil Shale project, a facility operating to the north of the industrial city of Gladstone, Australia. The aims of the investigations were threefold: (a) the identification of the plant signatures in terms of particle size distributions in the submicrometer range (13-830 nm) through stack measurements, (b) exploring the applicability of these signatures in tracing the source contributions at locations of interest, at a distance from the plant, and (c) assessing the contribution of the plant to the total particle number concentration at locations of interest. The stack measurements conducted for three different conditions of plant operation showed that the particle size distributions were bimodal with average modal count median diameters (CMDs) of 24 (SD 4) and 52 (SD 9) nm. The average of all the particle size distributions recorded within the plant sector at a site located 4.5 km from the plant, over the s ling period when the plant was operating, also showed a bimodal distribution. The modal CMDs in this case were 27 and 50 nm, similar to those at the stack. This bimodal size distribution is distinct from the size distribution of the most common ambient anthropogenic emission source, which is vehicle emissions, and can be considered as a signature of this source. The average contribution of the plant (for plant sector winds) was estimated to be (10.0 +/- 3.8) x 10(2) particles cm(-3) and constituted approximately a 50% increase overthe local particle ambient concentration for plant sector winds. This increase in particle number concentration compared to the local background concentration, while high compared to the clean environment concentration, is not significant when compared to concentrations generally encountered in the urban environment of Brisbane.

Ambient nano and ultrafine particles from motor vehicle emissions: Characteristics, ambient processing and implications on human exposure

Publisher: Elsevier BV

Date: 11-2008

DOI: 10.1016/J.ATMOSENV.2008.07.050

Effect of pulsed power on particle matter in diesel engine exhaust using a DBD plasma reactor

Publisher: Institute of Electrical and Electronics Engineers (IEEE)

Date: 08-2013

DOI: 10.1109/TPS.2013.2270015

Diurnal profiles of particle-bound ROS of PM2.5 in urban environment of Hong Kong and their association with PM2.5, black carbon, ozone and PAHs

Publisher: Elsevier BV

Date: 12-2019

DOI: 10.1016/J.ATMOSENV.2019.117023

Role of Chinese cooking emissions on ambient air quality and human health

Publisher: Elsevier BV

Date: 07-2017

DOI: 10.1016/J.SCITOTENV.2017.02.124

Abstract: Chinese-style cooking often involves volatilization of oils which can potentially produce a large number of pollutants, which have adverse impact on environment and human health. Therefore, we have reviewed 75 published studies associated with research topic among Mainland China, Hong Kong and Taiwan, involving studies on the roles of food ingredients and oil type, cooking style impacting on generated pollutants, and human health. The highest concentration occurred including: 1) when peat, wood, and raw coal were used in stoves 2) olive oil was adopted 3) cooking with high temperatures and 4) without cleaning technology. We conclude that PM concentrations for cooking emissions were between 0.14 and 24.46mg/cm

Investigation of microalgae HTL fuel effects on diesel engine performance and exhaust emissions using surrogate fuels

Publisher: Elsevier BV

Date: 11-2017

DOI: 10.1016/J.ENCONMAN.2017.09.016

Widening the gap between measurement and modelling of secondary organic aerosol properties?

Publisher: Copernicus GmbH

Date: 15-03-2010

DOI: 10.5194/ACP-10-2577-2010

Abstract: Abstract. The link between measured sub-saturated hygroscopicity and cloud activation potential of secondary organic aerosol particles produced by the chamber photo-oxidation of α-pinene in the presence or absence of ammonium sulphate seed aerosol was investigated using two models of varying complexity. A simple single hygroscopicity parameter model and a more complex model (incorporating surface effects) were used to assess the detail required to predict the cloud condensation nucleus (CCN) activity from the sub-saturated water uptake. Sub-saturated water uptake measured by three hygroscopicity tandem differential mobility analyser (HTDMA) instruments was used to determine the water activity for use in the models. The predicted CCN activity was compared to the measured CCN activation potential using a continuous flow CCN counter. Reconciliation using the more complex model formulation with measured cloud activation could be achieved widely different assumed surface tension behavior of the growing droplet this was entirely determined by the instrument used as the source of water activity data. This unreliable derivation of the water activity as a function of solute concentration from sub-saturated hygroscopicity data indicates a limitation in the use of such data in predicting cloud condensation nucleus behavior of particles with a significant organic fraction. Similarly, the ability of the simpler single parameter model to predict cloud activation behaviour was dependent on the instrument used to measure sub-saturated hygroscopicity and the relative humidity used to provide the model input. However, agreement was observed for inorganic salt solution particles, which were measured by all instruments in agreement with theory. The difference in HTDMA data from validated and extensively used instruments means that it cannot be stated with certainty the detail required to predict the CCN activity from sub-saturated hygroscopicity. In order to narrow the gap between measurements of hygroscopic growth and CCN activity the processes involved must be understood and the instrumentation extensively quality assured. It is impossible to say from the results presented here due to the differences in HTDMA data whether: i) Surface tension suppression occurs ii) Bulk to surface partitioning is important iii) The water activity coefficient changes significantly as a function of the solute concentration.

The influence of fatty acid methyl ester profiles on inter-cycle variability in a heavy duty compression ignition engine

Publisher: Elsevier BV

Date: 2014

DOI: 10.1016/J.FUEL.2013.07.100

Nocturnal new particle formation events in urban environment

Publisher: Copernicus GmbH

Date: 20-07-2016

DOI: 10.5194/ACP-2016-521

Abstract: Abstract. Few studies have investigated nocturnal new particle formation (NPF) events, and none of them were conducted in urban environments. Nocturnal NPF can potentially be a significant source of particles in urban areas, and studying them would improve our understanding of nucleation mechanisms. To address this, our study was conducted in an urban environment to investigate the physical characteristics of NPF events, with a particular focus on nocturnal events and the differences between them and the daytime NPF events. Particle number size distribution (PNSD) was measured for two weeks at each of 25 sites across an urban environment. A new method was proposed to automatically categorise NPF events based on growth rate (GR) in order to remove the bias related to the manual procedure. Out of 219 observed events, 118 and 101 were categorised into class I and II respectively and 73 happened during the night time which included more than 30 % of the events. GR and condensation sink (CS) were calculated and a slight negative relationship between GR and CS was observed, and production of condensable vapour was lower in nighttime NPF events compared to daytime. Nocturnal events on average displayed 10 % higher GRs compared to day time ones. Back trajectory analysis was also conducted to estimate the locations of the sources of day time and nocturnal precursors. While the precursors related to day time events originated from different locations with no particular pattern, back-trajectory analysis showed many air masses associated with nocturnal NPF events were transported from over the ocean. Overall, nocturnal NPF events were found to be a significant source of particles in the studied environment with different physical characteristics/sources compared to day time events.

Composition, size and cloud condensation nuclei activity of biomass burning aerosol from northern Australian savannah fires

Publisher: Copernicus GmbH

Date: 14-03-2017

DOI: 10.5194/ACP-17-3605-2017

Abstract: Abstract. The vast majority of Australia's fires occur in the tropical north of the continent during the dry season. These fires are a significant source of aerosol and cloud condensation nuclei (CCN) in the region, providing a unique opportunity to investigate the biomass burning aerosol (BBA) in the absence of other sources. CCN concentrations at 0.5 % supersaturation and aerosol size and chemical properties were measured at the Australian Tropical Atmospheric Research Station (ATARS) during June 2014. CCN concentrations reached over 104 cm−3 when frequent and close fires were burning – up to 45 times higher than periods with no fires. Both the size distribution and composition of BBA appeared to significantly influence CCN concentrations. A distinct diurnal trend in the proportion of BBA activating to cloud droplets was observed, with an activation ratio of 40 ± 20 % during the night and 60 ± 20 % during the day. BBA was, on average, less hygroscopic during the night (κ = 0. 04 ± 0.03) than during the day (κ = 0.07 ± 0.05), with a maximum typically observed just before midday. Size-resolved composition of BBA showed that organics comprised a constant 90 % of the aerosol volume for aerodynamic diameters between 100 and 200 nm. While this suggests that the photochemical oxidation of organics led to an increase in the hygroscopic growth and an increase in daytime activation ratios, it does not explain the decrease in hygroscopicity after midday. Modelled CCN concentrations assuming typical continental hygroscopicities produced very large overestimations of up to 200 %. Smaller, but still significant, overpredictions up to ∼ 100 % were observed using aerosol mass spectrometer (AMS)- and hygroscopicity tandem differential mobility analyser (H-TDMA)-derived hygroscopicities as well as c aign night and day averages. The largest estimations in every case occurred during the night, when the small variations in very weakly hygroscopic species corresponded to large variations in the activation diameters. Trade winds carry the smoke generated from these fires over the Timor Sea, where aerosol–cloud interactions are likely to be sensitive to changes in CCN concentrations, perturbing cloud albedo and lifetime. Dry season fires in northern Australia are therefore potentially very important in cloud processes in this region.

Comprehensive aerosol and gas data set from the Sydney Particle Study

Publisher: Copernicus GmbH

Date: 02-12-2019

DOI: 10.5194/ESSD-11-1883-2019

Abstract: Abstract. The Sydney Particle Study involved the comprehensive measurement of meteorology, particles and gases at a location in western Sydney during February–March 2011 and April–May 2012. The aim of this study was to increase scientific understanding of particle formation and transformations in the Sydney airshed. In this paper we describe the methods used to collect and analyse particle and gaseous s les, as well as the methods employed for the continuous measurement of particle concentrations, particle microphysical properties, and gaseous concentrations. This paper also provides a description of the data collected and is a metadata record for the data sets published in Keywood et al. (2016a, 0.4225/08/57903B83D6A5D) and Keywood et al. (2016b, 0.4225/08/5791B5528BD63).

Influence of the buffer layer on the FIR reflectivity spectra of a thick superlattice

Publisher: Elsevier BV

Date: 03-1997

DOI: 10.1006/SPMI.1995.0166

Review of acp-2019-190

Publisher: No publisher found

Date: 2019

DOI: 10.5194/ACP-2019-190-RC1

Nocturnal new particle formation events in urban environments

Publisher: Copernicus GmbH

Date: 11-01-2017

DOI: 10.5194/ACP-17-521-2017

Abstract: Abstract. Few studies have investigated nocturnal new particle formation (NPF) events, and none of them were conducted in urban environments. Nocturnal NPF can potentially be a significant source of particles in urban areas, and studying them would improve our understanding of nucleation mechanisms. To address this, our study was conducted in an urban environment to investigate the physical characteristics of NPF events, with a particular focus on nocturnal events and the differences between them and the daytime NPF events. Particle number size distribution (PNSD) was measured for 2 weeks at each of 25 sites across an urban environment. A new method was proposed to automatically categorise NPF events based on growth rate (GR) in order to remove the bias related to the manual procedure. Out of 219 observed events, 118 and 101 were categorised into class I and II respectively and 73 happened during the nighttime which included more than 30 % of the events. GR and condensation sink (CS) were calculated and a slight negative relationship between GR and CS was observed. Nocturnal events displayed higher GRs compared to daylight ones which were on average about 10 %. Back trajectory analysis was also conducted to estimate the locations of the sources of daylight and nocturnal precursors. While the precursors related to daylight events originated from different locations with no particular pattern, back-trajectory analysis showed many air masses associated with nocturnal NPF events were transported from over the ocean. Overall, nocturnal NPF events were found to be a significant source of particles in the studied environment with different physical characteristics and/or sources compared to daylight events.

Influence of fuel-oxygen content on morphology and nanostructure of soot particles

Publisher: Elsevier BV

Date: 07-2019

DOI: 10.1016/J.COMBUSTFLAME.2019.04.009

Volcanic sulphate and arctic dust plumes over the North Atlantic Ocean

Publisher: Elsevier BV

Date: 10-2009

DOI: 10.1016/J.ATMOSENV.2009.07.007

Biomass burning emissions of trace gases and particles in marine air at Cape Grim, Tasmania

Publisher: Copernicus GmbH

Date: 07-12-2015

DOI: 10.5194/ACP-15-13393-2015

Abstract: Abstract. Biomass burning (BB) plumes were measured at the Cape Grim Baseline Air Pollution Station during the 2006 Precursors to Particles c aign, when emissions from a fire on nearby Robbins Island impacted the station. Measurements made included non-methane organic compounds (NMOCs) (PTR-MS), particle number size distribution, condensation nuclei (CN) 3 nm, black carbon (BC) concentration, cloud condensation nuclei (CCN) number, ozone (O3), methane (CH4), carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), nitrous oxide (N2O), halocarbons and meteorology. During the first plume strike event (BB1), a 4 h enhancement of CO (max ~ 2100 ppb), BC (~ 1400 ng m-3) and particles 3 nm (~ 13 000 cm-3) with dominant particle mode of 120 nm were observed overnight. A wind direction change lead to a dramatic reduction in BB tracers and a drop in the dominant particle mode to 50 nm. The dominant mode increased in size to 80 nm over 5 h in calm sunny conditions, accompanied by an increase in ozone. Due to an enhancement in BC but not CO during particle growth, the presence of BB emissions during this period could not be confirmed. The ability of particles 80 nm (CN80) to act as CCN at 0.5 % supersaturation was investigated. The ΔCCN / ΔCN80 ratio was lowest during the fresh BB plume (56 ± 8 %), higher during the particle growth period (77 ± 4 %) and higher still (104 ± 3 %) in background marine air. Particle size distributions indicate that changes to particle chemical composition, rather than particle size, are driving these changes. Hourly average CCN during both BB events were between 2000 and 5000 CCN cm-3, which were enhanced above typical background levels by a factor of 6–34, highlighting the dramatic impact BB plumes can have on CCN number in clean marine regions. During the 29 h of the second plume strike event (BB2) CO, BC and a range of NMOCs including acetonitrile and hydrogen cyanide (HCN) were clearly enhanced and some enhancements in O3 were observed (ΔO3 / ΔCO 0.001–0.074). A short-lived increase in NMOCs by a factor of 10 corresponded with a large CO enhancement, an increase of the NMOC / CO emission ratio (ER) by a factor of 2–4 and a halving of the BC / CO ratio. Rainfall on Robbins Island was observed by radar during this period which likely resulted in a lower fire combustion efficiency, and higher emission of compounds associated with smouldering. This highlights the importance of relatively minor meteorological events on BB emission ratios. Emission factors (EFs) were derived for a range of trace gases, some never before reported for Australian fires, (including hydrogen, phenol and toluene) using the carbon mass balance method. This provides a unique set of EFs for Australian coastal heathland fires. Methyl halide EFs were higher than EFs reported from other studies in Australia and the Northern Hemisphere which is likely due to high halogen content in vegetation on Robbins Island. This work demonstrates the substantial impact that BB plumes can have on the composition of marine air, and the significant changes that can occur as the plume interacts with terrestrial, aged urban and marine emission sources.

Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities

Publisher: Elsevier BV

Date: 03-2009

DOI: 10.1016/J.JAEROSCI.2008.11.002

Removal of Organic Content from Diesel Exhaust Particles Alters Cellular Responses of Primary Human Bronchial Epithelial Cells Cultured at an Air-Liquid Interface

Publisher: OMICS Publishing Group

Date: 2015

DOI: 10.4172/2161-0525.1000316

Precursors to Particles (P2P) at Cape Grim 2006: campaign overview

Publisher: CSIRO Publishing

Date: 2007

DOI: 10.1071/EN07041

Abstract: Environmental context. Understanding the role of clouds in assessing the impact of climate change is a challenging issue. It is thought that plankton and seaweed contribute to the formation of clouds by emitting gases that lead to the particle production necessary for cloud formation. Macroalgae (kelp) at Mace Head, Ireland, produce large quantities of iodine when exposed to sunlight at low tide and this iodine results in the rapid production of particles. Cape Grim, Tasmania, also has large colonies of kelp and the role of Bull Kelp (Durvillaea potatorum) in particle production was assessed. Abstract. Iodine emissions from coastal macroalgae have been found to be important initiators for nucleation events at Mace Head, Ireland. The source of this iodine is the large beds of the brown kelp Laminaria digitata, which are significantly exposed at low tide. On the coast around Cape Grim, Tasmania, there are beds of the brown kelp Durvillaea potatrum. The Precursors to Particles 2006 (P2P 2006) c aign at the Cape Grim Baseline Air Pollution Station in late summer (February) 2006 focused on the role of this local kelp in providing precursor gases to particle formation. Durvillaea potatorum does not produce iodated precursor gases at the levels observed at Mace Head. IO was measured at 0.5 ± 0.3 ppt, while OIO was below detection limits (9 ppt). The dominant atmospheric iodated species was methyl iodide and the average concentration measured at the Cape Grim Station was 1.5 ± 0.3 pptv in baseline conditions, but showed significant variation in discrete s les collected immediately above the ocean surface. Nucleation events were not detected at the Cape Grim Station, except for one period where the plume of a local bushfire interacted with air of marine origin. The passage of four fronts did not result in nucleation bursts and measurements on the beach 94 m below the Cape Grim Station suggested that Durvillaea potatorum was only a weak source of new particles.

Far infrared reflectivity of a GaAs/Al0.33Ga0.67As multiple quantum well structure

Publisher: Elsevier BV

Date: 02-1996

DOI: 10.1016/0026-2692(95)00057-7

Concentration and source identification of polycyclic aromatic hydrocarbons in the metropolitan area of Belgrade, Serbia

Publisher: Elsevier BV

Date: 07-2015

DOI: 10.1016/J.ATMOSENV.2015.04.034

In search of an optimal in-field calibration method of low-cost gas sensors for ambient air pollutants: Comparison of linear, multilinear and artificial neural network approaches

Publisher: Elsevier BV

Date: 09-2019

DOI: 10.1016/J.ATMOSENV.2019.06.028

The effect of diesel fuel sulphur and vanadium on engine performance and emissions

Publisher: Elsevier BV

Date: 02-2020

DOI: 10.1016/J.FUEL.2019.116437

University Of Belgrade School Of Electrical Engineering

Location: Serbia

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Queensland University Of Technology

Location: Australia

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Airborne Ultrafine Particles In Australian Cities

Start Date: 2019

End Date: 2021

Funder: Australian Research Council

Quantification Of Current And Future Traffic Emissions Of Greenhouse Gases And Particulate Matter For Application In Transport And Urban Planning

Start Date: 2007

End Date: 2009

Funder: Australian Research Council

Optimisation Of Dual Fuel Compression Ignition (Diesel) Engines With Respect To Engine Performance And Pollutant Emissions.

Start Date: 2007

End Date: 2009

Funder: Australian Research Council

Establishing Advanced Networks For Air Quality Sensing And Analyses

Start Date: 2016

End Date: 2018

Funder: Australian Research Council

Semi-volatile Particulate Matter (PM) Species In Roadside Environment: Role In Gas-particle Partitioning And Formation Of Oxidative Potential

Start Date: 2015

End Date: 2017

Funder: University Grants Committee

Secondary Aerosol Formation From Engine Exhaust Emissions

Start Date: 2018

End Date: 2020

Funder: Australian Research Council

Quantification Of Traffic Generated Nano And Ultrafine Particle Dynamics And Toxicity In Transit Hubs And Transport Corridors

Start Date: 2008

End Date: 2011

Funder: Australian Research Council

The Effect Of Fuel Type On Health And Environmental Risks Caused By Motor Vehicle Emissions

Start Date: 2002

End Date: 2004

Funder: Australian Research Council

The Effects Of Nano And Ultrafine Particles From Traffic Emissions On Children's Health

Start Date: 2009

End Date: 2013

Funder: Australian Research Council

Developing And Validating An Air Quality Assessment Model For Application In Human Exposure Assessment, Housing/urban Planning And Policy Setting

Start Date: 2002

End Date: 2004

Funder: Australian Research Council

Time Of Flight Aerosol Mass Spectrometer For Research On Airborne Particles And Their Impact On Health And The Environment

Start Date: 2006

End Date: 2006

Funder: Australian Research Council

DEVELOPING SCIENTIFIC BASIS FOR THE RAPID DETECTION SYSTEM OF DIESEL VEHICLES WITH HIGH LEVEL OF EXHAUST EMISSIONS

Start Date: 2004

End Date: 2006

Funder: Australian Research Council

AN INTEGRATED MODEL OF BUS EMISSION IMPACTS AT AND AROUND BUS STATIONS AND BUSWAYS FOR TRANSPORT AND LAND USE PLANNING

Start Date: 2003

End Date: 2005

Funder: Australian Research Council

Mechanisms Of Virus Transport In Indoor Environments

Start Date: 2005

End Date: 2007

Funder: Australian Research Council

Optimising Gaseous And Particulate Emissions From Diesel Engines

Start Date: 2011

End Date: 2014

Funder: Australian Research Council

A Fundamental Study Into The Role Of The Organic Fraction On The Toxicity Of Combustion Generated Airborne Particles

Start Date: 2012

End Date: 2014

Funder: Australian Research Council

Ultra-high-performance Liquid Chromatography Ion Trap Mass Spectrometer To Develop New Capabilities In Environmental And Human Toxicology

Start Date: 2011

End Date: 2011

Funder: Australian Research Council

GBR As A Significant Source Of Climatically Relevant Aerosol Particles

Start Date: 2015

End Date: 2017

Funder: Australian Research Council

Atmospheric Integrated Research On Burdens And Oxidative Capacity

Start Date: 2015

End Date: 2015

Funder: Australian Research Council

Discovery Projects - Grant ID: DP120100126

Start Date: 06-2012

End Date: 12-2015

Amount: $390,000.00

Funder: Australian Research Council

Industrial Transformation Training Centres - Grant ID: IC220100012

Start Date: 07-2023

End Date: 07-2028

Amount: $4,939,486.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0558410

Start Date: 03-2005

End Date: 06-2008

Amount: $274,318.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0454296

Start Date: 06-2004

End Date: 12-2007

Amount: $89,770.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP180100516

Start Date: 12-2019

End Date: 12-2023

Amount: $889,797.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0882544

Start Date: 07-2008

End Date: 08-2012

Amount: $485,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0211775

Start Date: 04-2002

End Date: 12-2005

Amount: $216,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0668513

Start Date: 2006

End Date: 12-2007

Amount: $280,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0219590

Start Date: 04-2002

End Date: 12-2007

Amount: $149,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP110200158

Start Date: 06-2012

End Date: 12-2016

Amount: $330,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE150100048

Start Date: 09-2015

End Date: 12-2016

Amount: $630,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0990134

Start Date: 07-2009

End Date: 12-2013

Amount: $774,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE220100103

Start Date: 07-2022

End Date: 12-2023

Amount: $328,389.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE230100008

Start Date: 2023

End Date: 12-2023

Amount: $831,200.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0347152

Start Date: 07-2003

End Date: 12-2006

Amount: $140,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0775178

Start Date: 2007

End Date: 12-2009

Amount: $300,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP210103284

Start Date: 07-2021

End Date: 12-2024

Amount: $351,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP200301123

Start Date: 2023

End Date: 06-2026

Amount: $898,013.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160100051

Start Date: 04-2017

End Date: 04-2020

Amount: $445,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE110100032

Start Date: 05-2011

End Date: 05-2012

Amount: $240,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP180102632

Start Date: 02-2018

End Date: 06-2022

Amount: $354,636.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0775260

Start Date: 2007

End Date: 12-2009

Amount: $219,995.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP150101649

Start Date: 05-2015

End Date: 12-2017

Amount: $263,500.00

Funder: Australian Research Council