ORCID Profile
0000-0003-4009-5262
Current Organisation
UNSW Sydney
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Publisher: Wiley
Date: 15-09-2021
DOI: 10.1002/HTJ.22326
Abstract: The present study investigates exergy analysis of optimal designed spiral plate heat exchangers (SPHEs) based on energy criteria. A new design algorithm is developed to obtain a higher overall heat transfer coefficient and more compact SPHE by (1) maintaining the geometric aspect ratio (GAR), (2) enhancing channel pressure drops, and (3) minimizing the total costs. Mathematical modeling of spiral turns of designed SPHEs as a hypothetical network of heat exchangers (HEs), and implementation of energy balance equations contribute to the determination of channel temperature distributions. In the second part of the study, two new dimensionless energy‐based numbers have been introduced besides thermal effectiveness, temperature difference number, and modified temperature difference number. These two newly defined dimensionless numbers can add to the exergy evaluation in channels. To reach the set goals, several studies are conducted in different cases of single‐phase counter‐current SPHEs. First, temperature distribution obtained from the mathematical modeling was validated with computational fluid dynamics simulation results, which shows less than 5% deviation in dimensionless temperature distribution. Afterward, results of energy‐based criteria were assessed by thermal effectiveness correlation of counter‐current HEs. Second, comparing the new algorithm with other algorithms highlights the key role of GAR, pressure drop, and economic factors. The results show the highest enhancement in the relative heat rate capacity per volume of the newly designed SPHE, up to 54%, in comparison with other designs. Finally, analysis of various designed SPHEs and their channels confirms the reliability of newly defined criteria and temperature distribution significance in performance and irreversibility evaluation of spiral turns. Nevertheless, results show contradictions in total exergy loss number for SPHEs with larger and smaller than 12 spiral turns in numbers
Publisher: World Scientific Pub Co Pte Ltd
Date: 08-2018
DOI: 10.1142/S0219455418400114
Abstract: Movement of bridge abutment is a significant issue affecting the overall reliability and safety of the structure. However, despite considerable consequences, potential movement of abutment is usually not considered in design of bridges for serviceability and abutments are generally designed as fixed elements. Theoretical analysis of bridge abutment and deck design provides background knowledge of reactions that should be anticipated and accounted for. Case studies of bridges experiencing movements and rotations show that practical outcomes often deviate from theoretical expectations. The research presented in this paper, aims to develop a better understanding of abutment stability from both a design and maintenance point of view. This paper includes an in-depth case study of the Kanahooka Road Overbridge in New South Wales, Australia. The results of a full bridge inspection leading to identification of multiple serviceability issues caused by movement of abutments are presented. Moreover, a systematic methodology is implemented, to identify potential remedial options for treatment of abutment movement. The knowledge gained through this case study has led to the development of a model for the management of abutment movement.
Publisher: Elsevier BV
Date: 08-2014
Publisher: MDPI AG
Date: 05-04-2019
DOI: 10.3390/EN12071313
Abstract: Exergy analysis is one of the useful decision-support tools in assessing the environmental impact related to waste emissions from fossil fuel. This paper proposes a thermodynamic-based design to estimate the exergy quantity and losses during the recycling of copper and other valuable metals out of electronic waste (e-waste) through a secondary copper recycling process. The losses related to recycling, as well as the quality losses linked to metal and oxide dust, can be used as an index of the resource loss and the effectiveness of the selected recycling route. Process-based results are presented for the emission exergy of the major equipment used, which are namely a reduction furnace, an oxidation furnace, and fire-refining, electrorefining, and precious metal-refining (PMR) processes for two scenarios (secondary copper recycling with 50% and 30% waste printed circuit boards in the feed). The results of the work reveal that increasing the percentage of waste printed circuit boards (PCBs) in the feed will lead to an increase in the exergy emission of CO2. The variation of the exergy loss for all of the process units involved in the e-waste treatment process illustrated that the oxidation stage is the key contributor to exergy loss, followed by reduction and fire refining. The results also suggest that a fundamental variation of the emission refining through a secondary copper recycling process is necessary for e-waste treatment.
Publisher: SAGE Publications
Date: 14-05-2022
DOI: 10.1177/15280837221101213
Abstract: Recently, new developments in the design and performance optimization of smart mechanisms associated with natural and man-made hazards have progressed considerably. This is mainly owing to advances in smart sensing mechanisms including communication and data technologies. This work provides a detailed overview of existing improvements on smart hazard monitoring equipment and materials applied in textile sensing systems. Given that fire is one of the most common disasters in many countries such as Australia, and every year many firefighters are affected by these unfortunate incidents, the focus of this study is on firefighters' protective clothing Fire Fighter Protective clothing. This review provides a unique opportunity to study smart sensing systems in coating technologies, potentially provides more effective techniques for training and better safety protocols of fire fighters. It aims to revisit the existing advances and address recent challenges and opportunities for improvement in the domain of smart coating and fire protective wearables. The goal of this review is to provide information about smart coating in protective clothing for firefighters. The capability of some of these clothing in managing thermal stresses, responding to humid environment, monitoring some critical parameters and adapting to the size of the wearers (clothes fabricated with phase change and shape memory substances) made them attractive choice in adjusting specific design features of industrial textiles. Various types of phase change and shape memory substances are defined and a combination of these substances within the structure of fabrics are presented. This paper also provides a detailed review on the heat exposure and capability of the shape memory substances (SMM) and phase change materials (PCM) to delay the heat transfer through fire fighter protective clothing. Referring to the former research, several issues have been detected using such substances. For instance, combination of phase change and shape memory materials needs fundamental improvements with regards to assessment techniques and testing criteria. Additionally, recent improvements in the domain of PCM and SMM including modifying mechanical features, functionality, and durability under different conditions have been informed. It has been suggested that the major problem in developing fabric-Phase Change Materials (PCMs) and Shape memory material (SMM) systems is their usage methods. At last recent developments on wearable monitoring systems applied in the firefighters’ protective gear. Wearable sensors are usually used directly on the body or located on wearable items to monitor information related to firefighters’ safety.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Oxford University Press (OUP)
Date: 21-08-2021
DOI: 10.1093/JCDE/QWAA061
Abstract: In this study, a nonlinear numerical method is presented to solve the governing equations of generalized thermoelasticity in a large deformation domain of an elastic medium subjected to thermal shock. The main focus of the study is on the modified Green–Lindsay thermoelasticity theory, solving strain and temperature rate-dependent model using finite strain theory. To warrant the continuity of the finding responses at the boundary after the applied shock, higher order elements are adopted. An analytical solution is provided to validate the numerical findings and an acceptable agreement between the two presented solutions is obtained. The findings revealed that stress and thermal waves have distinct interactions and a harmonic temperature variation may lead to a systematic uniform stress distribution. Besides, a notable difference in the results predicted by the modified Green–Lindsay model and classic theory is observed. It is also found that the modified Green–Lindsay theory is more efficient in determining the wave propagation phenomenon. Furthermore, the findings established that thermal shock induces tensile stresses in the structure immediately after the shock, and the perceived phenomenon mainly depends on the defined boundary conditions. The results show that the strain rate can have a significant influence on the displacement and stress wave propagation in a structure subjected to thermal shock and these impacts may be more considerable with mechanical loading.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 10-2020
Publisher: Springer Science and Business Media LLC
Date: 24-08-2020
Publisher: Informa UK Limited
Date: 11-11-2021
Publisher: Elsevier BV
Date: 11-2023
Publisher: Elsevier BV
Date: 12-2021
Publisher: Indian Council of Agricultural Research, Directorate of Knowledge Management in Agriculture
Date: 16-12-2020
DOI: 10.56093/IJAS.V90I11.108564
Abstract: The success of any pearl millet hybrid programme depends upon the assessment of the structure of parental ersity. In this investigation, polymorphism data generated using 42 simple sequence repeat (SSR) markers and 12 agromorphological traits were used for genetic ersity assessment among 32 genotypes (29 restorers and 3 maintainers) of pearl millet [Pennisetum glaucum (L.) R. Br.].In contrast to morphological data, SSR based clustering pattern and Principal Coordinate Analysis revealed that the genotypes were found to be consistent with their pedigree and origin. Polymorphism information content (PIC) values based on microsatellites ranged from 0.117 to 0.841 per locus with an average PIC of 0.348. Allelic richness varied from two to five per locus. The highest similarity index (0.74) was observed between restorers WGI 58 and WGI 148, whereas the lowest similarity index (0.27) was observed between seed parent 841 B and PPMI 269. AMOVA analysis observed more genetic variance among the in iduals than within in iduals.The study led to the identification of maintainer 841 B as a genetically erse parent from other maintainers as well as among most of the restorers and hence may be used in future hybrid development programmes. Further, the correlation between phenotypic and genetic distance matrices was observed to be very low. Appropriate heterotic combinations were identified based on morphological and molecular ersity.
Publisher: Springer Science and Business Media LLC
Date: 28-10-2020
Publisher: MDPI AG
Date: 27-01-2022
DOI: 10.3390/FIRE5010017
Abstract: This paper presents an investigation on the effect of fire intensity of a wind driven surface fire, similar to a large wildfire, on an idealized structure located downstream from the fire source. A numerical simulation was conducted using an open source CFD code called FireFOAM, which is a transient solver for fire simulation and turbulent diffusion flames, supported by a large eddy simulation (LES) solver for incompressible flow. The numerical data were verified using the aerodynamic experimental data of a full-scale building model with no fire effects. An idealized cubic obstacle representing a simplified building with the dimension of 6 × 6 × 6 m is considered downstream from the fire source. Different fire intensity values of the fire line representing different grassland fuels were simulated to analyse the impact of wind-fire interaction on a built area. To solve the problem, a coupled velocity and pressure method was applied through a PIMPLE scheme in FireFoam solver of OpenFoam platform. There is a good agreement between simulated results and experimental measurements with a maximum error of 18%, which confirms the validity and accuracy of the model. The results showed that by increasing the fire intensity the velocity of the crosswind stream increases, which causes low-density air and generates an extra stream behind the fire plume. It was also found that increasing fire intensity from 10 MW/m to 18 MW/m raises the integrated temperature on the ground near the building and on the surface of the building by 26%, and 69%, respectively.
Publisher: Springer Science and Business Media LLC
Date: 11-03-2019
Publisher: MDPI AG
Date: 07-02-2020
DOI: 10.3390/SU12031208
Abstract: Environmental concerns have increased due to the amount of unused/expired plastic medical waste generated in hospitals, laboratories, and other healthcare facilities, in addition to the fact that disposing of such wastes with extremely low degradation levels causes them to remain in the environment for extended periods of time. These issues have led researchers to develop more environmentally friendly alternatives for disposing of plastic medical waste in Australia. This study is an attempt to assess the impacts of using expired plastic syringes as fine aggregate on fresh and hardened characteristics of flowable concrete, which might provide a solution to environmental concerns. Six mixtures of flowable concrete with water-to-cement ratios of 0.38 were studied. It was found that using recycled aggregate in up to 20% can improve the workability and increase the V-funnel values of flowable concrete mixtures. However, using waste aggregates in more than 30% caused an inapt flowability. Adding waste aggregate at the 30%–50% replacement level led to a decrease in the L-box ratio. To verify the utility and the efficacy of this experiment, the connections between different rheological test measurements were also compared by implementing the Pearson correlation function. The mechanical properties of the mixes containing recycled aggregates were decreased at the age of seven days however, at later ages, waste aggregates increased the strength at the 10%–30% replacement levels.
Publisher: Elsevier BV
Date: 07-2014
Publisher: Elsevier BV
Date: 12-2021
Publisher: MDPI AG
Date: 12-12-2021
DOI: 10.3390/FIRE4040094
Abstract: In this study, a time-dependent investigation has been conducted to numerically analyze the impact of wind-driven surface fire on an obstacle located on sloped terrain downstream of the fire source. Inclined field with different upslope terrain angles of 0, 10, 20, and 30° at various wind-velocities have been simulated by FireFoam, which is a large eddy simulation (LES) solver of the OpenFOAM platform. The numerical data have been validated using the aerodynamic measurements of a full-scale building model in the absence of fire effects. The results underlined the physical phenomena contributing to the impact of varying wind flow and terrain slope near the fire bed on a built area. The findings indicated that under a constant heat release rate and upstream wind velocity, increasing the upslope terrain angle leads to an increase in the higher temperature areas on the ground near the building. It is also found that raising the inclined terrain slope angle from 0 to 30°, results in an increase in the integrated temperature on the surface of the building. Furthermore, by raising the terrain slope from 0 to 30°, the integrated temperature on the ground for the mentioned cases increases by 16%, 10%, and 13%, respectively.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2018
Publisher: Elsevier BV
Date: 03-2022
Publisher: Oxford University Press (OUP)
Date: 07-01-2021
DOI: 10.1093/JCDE/QWAA082
Abstract: A review of the recent studies on the generalized thermoelasticity theories and their associated modified models is presented. The aim is to outline an overview of the utilization and physical limitations of available relevant theories. By contrast to classical thermoelasticity theory, generalized thermoelasticity theories (second sound) can involve a hyperbolic-form transport correlation and are motivated by experiments illustrating more accurately of the wave-form heat transfer (second sound). Many researchers have formulated such theories on different fields and analyzed various problems, presenting characteristic properties of these theories. This paper expresses a self-included bibliographical review of previous documents in the area of the second sound. The general structure of this review contains theories, formulations, real limitations, and used solution techniques of the equations for different geometries and loadings. Given that the classical theory is feeble in simulating the temperature distribution, especially in the structures under a sudden thermal shock, this review may be a useful tool for researchers who work in sensitive industries such as steam turbines, micro-temperature sensors, and lithium battery manufacturing.
Publisher: Elsevier BV
Date: 10-2017
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 06-2020
Publisher: American Association for the Advancement of Science (AAAS)
Date: 21-01-2022
Abstract: Improvements to perovskite solar cells (PSCs) have focused on increasing their power conversion efficiency (PCE) and operational stability and maintaining high performance upon scale-up to module sizes. We report that replacing the commonly used mesoporous–titanium dioxide electron transport layer (ETL) with a thin layer of polyacrylic acid–stabilized tin(IV) oxide quantum dots (paa-QD-SnO 2 ) on the compact–titanium dioxide enhanced light capture and largely suppressed nonradiative recombination at the ETL–perovskite interface. The use of paa-QD-SnO 2 as electron-selective contact enabled PSCs (0.08 square centimeters) with a PCE of 25.7% (certified 25.4%) and high operational stability and facilitated the scale-up of the PSCs to larger areas. PCEs of 23.3, 21.7, and 20.6% were achieved for PSCs with active areas of 1, 20, and 64 square centimeters, respectively.
Publisher: MDPI AG
Date: 14-12-2022
DOI: 10.3390/EN15249499
Abstract: In this paper, the effects of the fluid-thermal parameters of a porous medium with different values of porosity and permeability on the fluid flow, heat, and concentration parameters were investigated for solar energy applications. The characteristics of the boundary layer, velocity profiles, pressure drop, and thermal and high heat concentration distribution have been analyzed. A developed Brinkman equation for fluid flow and a power law model for thermal conductivity (considering the porosity and permeability factors) were calculated with constant solar heat flux. The numerical model was developed based on the finite element method by the LU algorithm using the MUMPS solver. The Brinkman equations were solved under steady and unsteady states for velocity, pressure, thermal, and concentration distribution effects, respectively. In a porous medium, the normalized temperature of the presented model had an acceptable agreement with the experimental data, with a maximum error of 3%. At constant permeability, by decreasing the porosity, the velocity profile was extended. This was mainly due to the presence of pores in the collector. With an accelerated flow, the maximum velocity of 2.5 m/s occurred at a porosity of 0.2. It was also found that in the porous collector, the Nusselt number increased where the maximum difference between the porous and the nonporous collectors occurred at the beginning of the collector, with a value of 32%, and the minimum difference was 27%. The results also indicate that in the porous collector, solar energy absorbance was higher and the heat transfer was improved. However, an increase in the pressure drop was noted in the porous collectors.
Publisher: MDPI AG
Date: 13-02-2023
DOI: 10.3390/EN16041854
Abstract: Plate Heat Exchanger (PHE) and Shell and Tube Heat Exchanger (STHE) with identical heat transfer areas and material characteristics are proposed and a comparative thermal and economic comparative analysis is carried out on both exchangers. Ag-water nanofluid is used at low concentrations (0, 2.5, 5, 10 mg/L), flow rates (2, 5, and 8 L/min), and inlet temperatures (36, 46, and 56 °C) as hot flow and the heat transfer coefficient (U), electrical power consumption of the pump, and costs per unit of average U value are considered as the calculated parameters for each heat exchanger in co-current and counter-current flows. The results revealed that PHE generates a higher U value compared to the STHE under different Ag-water nanofluid concentrations. This is due to the existence of grooves on the plates of PHE which generates turbulent flow. The impact of nanofluid concentration on U is negligible for lower concentrations in both PHE and STHE. It is also found that the nanofluid flow rate has the highest impact on the U value, just like conventional fluid. Besides, even though counter-current flow increases the U values for both PHE and STHE, the flow pattern has a higher impact on the U value of PHE than that of STHE. For both PHE and STHE, increasing the nanofluid flow rate enhances the amount of U. However, the effect of flow rate on the U value of PHE is greater than that of the STHE. It is also shown that throughout the entire experimental temperature domain, PHE has had higher performance than STHE, and as the fluid temperature increased from 36 to 56 °C, there was a slight increase in the overall heat transfer of both PHE and STHE. Furthermore, for the same flow rate, both PHE and STHE had almost the same pump power consumption, and increasing the nanofluid flow rate from 2 L/min to 8 L/min promoted the electrical power consumption of the pump. Finally, we found that the costs per unit of heat transfer coefficient for PHE are significantly lower than STHE. The presented results also indicated that using a vortex generator at the inlet of STHE tubes, to form turbulent flow, increases the U values of STHE for both co-current and counter-current flows but these U values are lower than the corresponding U values of PHE. Small plates gap in PHE structure cause higher fluid flow velocities and create a chain-like structure of nanoparticles (NPs) between PHE’s plates (especially at higher nanofluids concentrations).
Publisher: Elsevier BV
Date: 07-2022
Publisher: Springer Science and Business Media LLC
Date: 09-07-2018
DOI: 10.1038/S41467-018-05184-7
Abstract: The human gut microbiome has been associated with many health factors but variability between studies limits exploration of effects between them. Gut microbiota profiles are available for members of the deeply phenotyped TwinsUK cohort, providing a uniform platform for such comparisons. Here, we present gut microbiota association analyses for 38 common diseases and 51 medications within the cohort. We describe several novel associations, highlight associations common across multiple diseases, and determine which diseases and medications have the greatest association with the gut microbiota. These results provide a reference for future studies of the gut microbiome and its role in human health.
Publisher: Elsevier BV
Date: 10-2021
Publisher: Springer International Publishing
Date: 2018
Publisher: AIP Publishing
Date: 09-2021
DOI: 10.1063/5.0059779
Abstract: Studies on pressure-swirl atomizers have mainly focused on pressure-swirl atomizers with tangential input while there are limited studies on pressure-swirl atomizers with a spiral path. This study applies experimental and computational methods to provide a better understanding of flow development in this type of atomizer at the design point and outside the design point. Experimental results showed that as the pressure increases, the spray cone angle increases. This increase initially occurs with a higher slope and then the slope is toned down. While the drainage coefficient remains constant, the droplet diameter decreases as the pressure increases. It is observed that similar to the pressure-swirl atomizer with tangential input, the pressure-swirl atomizer with a spiral path has a conical hollow spray. At the constant mass flow rate, as the spiral path cross-section, the length of the swirl chamber and orifice diameter increase, the fluid film thickness and average diameter of droplets increase while the spray cone angle reduces. Further, increasing the number of spiral paths causes a wider spray cone angle, higher discharge coefficient, larger fluid film thickness, and larger droplet diameter. The results also showed that increasing the length of the orifice marginally affected the properties of the spray while significantly reducing the spray cone angle. It is important to note that the numerical results are in good agreement with the experimental data.
Publisher: Elsevier BV
Date: 04-2020
Publisher: Springer International Publishing
Date: 2018
Publisher: Elsevier
Date: 2020
Publisher: ASME International
Date: 07-10-2021
DOI: 10.1115/1.4052540
Abstract: This study presents a comparative experimental approach to analyze flame temperature, emissions, and radiation behaviors of an oil furnace fueled with nano biodiesel blend fuel containing suspended energetic and non-energetic nanoparticles (NPs). Iron NPs were used as energetic nanoparticles, and alumina (Al2O3) was selected as non-energetic NPs. A dilute homogeneous mixture (500 ppm) was provided from each NPs in B20 blend fuel. The fuels were burned in an oil burner subsequently, and infrared radiation (IR) images of flame, profiles of flame temperature, luminous and total radiation and NOx and CO emissions were gauged and compared. Measurements showed that both NPs improve the evaporation rate of fuel droplets and displace the peak of flame temperature to the flame upstream region. Moreover, nano biodiesel blend fuel containing energetic iron NPs elevates flame temperature while the non-energetic alumina NPs reduce the peak of flame temperature. In addition, both NPs strengthen the nucleation and growth of intermediate soot particles. These fuels containing suspended particles also lead to an increase in the intermediate soot particles content of flame and flame emissivity. This increases IR, luminous, and total flame radiation. The improvement of average flame radiative flux for nano biodiesel blend fuel containing energetic iron NPs and non-energetic alumina NPs is as high as 25% and 10%, respectively. Also, using energetic iron NPs and non-energetic alumina NPs in B20 fuel reduces the NOx emission by 13% and 11%, respectively.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 05-2023
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 10-2021
Publisher: Springer Science and Business Media LLC
Date: 21-07-2017
Publisher: Elsevier BV
Date: 07-2021
Publisher: MDPI AG
Date: 31-12-2022
DOI: 10.3390/FIRE6010012
Abstract: Wildfires are complex phenomena, both in time and space, in ecosystems. The ability to understand wildfire dynamics and to predict the behaviour of the propagating fire is essential and at the same time a challenging practice. A common approach to investigate and predict such phenomena is making the most of power of numerical models and simulators. Improved and more accurate methods for simulating fire dynamics are indispensable to managing suppression plans and controlled burns, decreasing the fuel load and having a better assessment of wildfire risk mitigation methodologies. This paper is focused on the investigation of existing simulator models applicable in predicting wildfire spread and wind fire interaction. The available software packages are outlined with their broad range of applications in fire dynamic modeling. Significance of each work and associated shortcomings are critically reviewed. Finally, advanced simulations and designs, accurate assumptions, and considerations for improving the numerical simulations, existing knowledge gaps in scientific research and suggestions to achieve more efficient developments in this area are revisited.
Publisher: Wiley
Date: 08-02-2023
DOI: 10.1002/CJCE.24848
Abstract: The modelling of a biomass fluidized bed gasification system, one of the most effective ways to produce energy from biomass resources and wastes, has been performed in this study. The effect of the turbulence phenomena, including calculations relating to flow turbulence, chemical fuel reactions, and energy and momentum exchange between multiple solid and gas phases, has been taken into account in the current research as a novel approach. A computational fluid dynamics case study model that combines equations with comprehensive geometry has been considered. Results have been compared with published operational records of an existing power plant to validate the model. The solid particle distribution, the velocity of the mixture and gas phase, the turbulent flow viscosity ratio, and the temperature distribution in the model indicated the accuracy of the simulation performance compared with the experimental studies. The production of the molar fraction of the constituent elements of the synthesis gas has been evaluated in transient conditions. Additionally, 35 s after the process began, the system's performance was estimated, and the results indicated the average molecular weights of hydrogen, carbon monoxide, carbon dioxide, and methane are 26%, 23%, 12.5%, and 3.3%, respectively, which presented high precision with the experimental results.
Publisher: SAGE Publications
Date: 03-2022
DOI: 10.1177/07349041221079004
Abstract: This review aims to present recent improvements and existing challenges in the design of wearable sensors used in the firefighters’ protective clothing. Wearable sensors are generally used directly on the body or placed on wearable items to monitor data for the safety of firefighters. Recently, wearable sensors have attracted much attention from researchers and experts. Most investigations have addressed novel designs for wearable sensors to enhance firefighters’ safety measures and reduce the risk of exposure to fires. This article is an attempt to review design limitations of wearable sensors for future developments and improve existing shortcomings. The growing body of knowledge focused on the application of wearable technology to monitor firefighters’ activity, health, and body temperature. In the following, we have discussed the trials of the design of the existing sensors. Finally, moisture and radiation as common exterior parameters in fire events are discussed which received less attention and have major impact on the performance of firefighters’ wearable sensors.
Publisher: Elsevier BV
Date: 07-2016
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
Date: 07-2022
DOI: 10.2514/1.T6465
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 05-2016
Publisher: OMICS Publishing Group
Date: 2018
Publisher: Springer International Publishing
Date: 2018
Publisher: Springer Science and Business Media LLC
Date: 09-11-2021
Publisher: Springer Science and Business Media LLC
Date: 13-07-2022
DOI: 10.1007/S10163-022-01459-W
Abstract: Waste treatment using thermal technologies, such as incineration, leads to the production of pollutants and wastes, including fly ash (FA). Fly ash contains heavy metals (HMs) and other contaminants and can potentially pose high risks to the environment and negatively impact health and safety. Consequently, stabilizing fly ash prior to either use or landfilling is crucial. The toxicity of fly ash through heavy metal leaching can be assessed using leaching tests. The leaching rates of heavy metals primarily depend on the surrounding conditions as well as fly ash properties and metal speciation. Physical separation, leaching or extraction, thermal treatment and solidification/chemical stabilization are proposed as suitable approaches for fly ash treatment. Economic considerations, environmental concerns, energy consumption and processing times can define the efficiency and selection of the treatment approach. This review considers the latest findings and compares the advantages and shortcomings of different fly ash treatment methods with the aim of highlighting the recent advances in the field. The review concludes that the simultaneous implementation of various methods can lead to highly efficient heavy metals removal/stabilization while simultaneously taking economic and environmental considerations into account.
Publisher: Springer Science and Business Media LLC
Date: 17-02-2020
Publisher: Springer Science and Business Media LLC
Date: 12-2022
Publisher: MDPI AG
Date: 10-05-2021
DOI: 10.3390/FIRE4020027
Abstract: This work provides a detailed overview of existing investigations into the fire–wind interaction phenomena. Specifically, it considers: the fanning effect of wind, wind direction and slope angle, and the impact of wind on fire modelling, and the relevant analysis (numerical and experimental) techniques are evaluated. Recently, the impact of fire on buildings has been widely analysed. Most studies paid attention to fire damage evaluation of structures as well as structure fire safety engineering, while the disturbance interactions that influence structures have been neglected in prior studies and must be analysed in greater detail. In this review article, evidence regarding the fire–wind interaction is discussed. The effect of a fire transitioning from a wildfire to a wildland–urban interface (WUI) is also investigated, with a focus on the impact of the resulting fire–wind phenomenon on high- and low-rise buildings.
Publisher: Elsevier BV
Date: 06-2022
Publisher: Elsevier BV
Date: 12-2017
Publisher: InTech
Date: 24-10-2018
Publisher: MDPI AG
Date: 20-11-2022
DOI: 10.3390/EN15228726
Abstract: In this study, the impact of hydrogen concentration on deflagration to detonation transition (DDT) and detonation diffraction mechanisms was investigated. The combustion chamber was an ENACCEF facility, with nine obstacles at a blockage ratio of 0.63 and three mixtures with hydrogen concentrations of 13%, 20%, and 30%. Detonation diffraction mechanisms were numerically investigated by a density-based solver of OpenFOAM CFD toolbox named ddtFoam. In this simulation, for the low Mach numbers, the pddtFoam solver was applied, and for high speeds, the pddtFoam solver switched to the ddtFoam solver to simulate flame propagation without resolving all microscopic details in the flow in the CFD grid, and to provide a basis for simulating flame acceleration (FA) and the onset of detonation in large three-dimensional geometries. The results showed that, for the lean H2–air mixture with 13% hydrogen concentration, intense interaction between propagating flame and turbulent flow led to a rapid transition from slow to fast deflagration. However, the onset of detonation did not occur inside the tube. For the H2–air mixture with 20% hydrogen concentration, the detonation initiation appeared in the acceleration tube. It was also found that following the diffraction of detonation, the collision of transverse waves with the wall of the tube and the reflection of transverse waves were the most essential and effective parameters in the re-initiation of the detonation. For the H2–air mixture with 30% hydrogen concentration, the detonation initiation occurred while passing through the obstacles. Subsequently, at detonation diffraction, the direct initiation mechanism was observed.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2020
Publisher: Elsevier BV
Date: 07-2021
Publisher: Elsevier BV
Date: 04-2022
Publisher: Elsevier BV
Date: 2023
Publisher: American Chemical Society (ACS)
Date: 31-10-2013
DOI: 10.1021/IE402267B
Publisher: Elsevier BV
Date: 12-2019
Publisher: Wiley
Date: 22-10-2020
Abstract: Herein, a model is developed based on energy balance equations to analyze and improve the performance of single‐phase counter‐current and co‐current flow spiral plate heat exchangers (SPHEs). The aim is to comprehensively check the performance and irreversibility factors based on energy, entropy, and entransy methods. First, a new optimization algorithm is proposed to maximize pressure drops and minimize the total cost by considering the geometric proportion of the SPHE. Second, the SPHE spiral turns are modeled as a series‐connected equivalent internal heat exchangers network to determine the temperature boundaries and develop the temperature–enthalpy diagram in analysis. The algorithm and modeling is validated in two stages for different flow arrangement SPHEs. Performance and irreversibility analysis shows similar result trends in different flow patterns. In third stage, a wide range of counter‐current flow SPHEs with constant heat transfer rate is designed, modeled, and analyzed by energy, entropy, and entransy methods. To recapitulate, results assert that SPHEs designed by new algorithm have higher overall heat‐transfer coefficient and compactness. Although entropy and entransy analyses reveal irreversibility trends with effectiveness in SPHEs, entransy analysis is more effective and reliable to analyze the SPHEs.
Publisher: ASME International
Date: 13-01-2022
DOI: 10.1115/1.4053171
Abstract: This paper presents a systematic analysis of the thermodynamic performance of spiral turns in spiral plate heat exchangers (SPHEs), including non-adiabatic sources such as effects of heat leakage to the environment and fluid friction. These sources can reduce the thermal performance and increase the irreversibility of SPHEs. First, the critical factors of the heat loss rate to the environment, internal heat transfer rate (HTR), and channel temperature distributions are specified based on modeling the SPHE with hypothetical heat exchanger networks. Also, this modeling is validated with the results of channel temperature distributions by computational fluid dynamics simulation. Second, besides examining the spiral turns by entropy generation methods, entransy-based parameters are developed to analyze the SPHEs based on generated heat due to fluid viscosity in their channels for the first time. Finally, to show the method applicability proposed, an optimal designed single-phase counter-current SPHE is explored as a case. Three scenarios are introduced to evaluate the performance and irreversibility, namely heat leakage and no heat leakage to the environment and transferring the net heat between the streams. Results highlight the effects of non-adiabatic conditions, such as reductions of around 5.46%, 2.25%, and 2.42%, respectively, in the heat transfer area, total HTR, and overall heat transfer coefficient. Furthermore, findings confirm the performance reductions and irreversibility increments in non-adiabatic conditions and assert the importance of covering the outermost channels appropriately.
Publisher: Springer Singapore
Date: 04-09-2020
Publisher: Springer International Publishing
Date: 2017
Publisher: AIP Publishing
Date: 07-2023
DOI: 10.1063/5.0153468
Abstract: Air-blast atomizers are widely used in passenger aircraft engines. In these atomizers, high-speed airflow is used for improved fuel atomization, and as a result, better combustion. The key purpose of this research is to investigate the duplex air-blast atomizers according to the engine data in the real operational conditions with the help of experimental method and numerical solution. When analyzing the variations in fuel sprays under different application conditions, it is important to consider not just one but multiple parameters such as fuel mass rate, air mass rate, and combustion chamber pressure. However, analyzing the in idual effects of these parameters can be challenging as they change simultaneously. To address this, a dimensionless number namely K was defined, which takes into account the combined effect of fuel mass rate, air mass rate, and combustion chamber pressure. The results showed that when K decreased by 31.25%, the spray angle of nozzle 1 and nozzle 2 increased by 10.09% and 48.15%, respectively, while the average droplet diameter caused by primary breakup for nozzle 1 and nozzle 2 decreased by 76.29% and 71.57%, respectively. The secondary breakup was somewhat similar, and for nozzle 1 and nozzle 2, the average droplet diameter decreased by 76.5% and 71.88%, respectively. It is worth noting that the average error for spray cone angle in the simulation compared to the experimental results was 6.47%. The results of this research, in addition to causing a better understanding of the atomization processes in air-blast atomizers, can be useful for aerospace engineers.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Informa UK Limited
Date: 17-01-2022
Publisher: MDPI AG
Date: 30-07-2018
Abstract: In this paper, the development process of a deployable modular sandwich panelized system for rapid-assembly building construction is presented, and its structural performance under some different action effects is investigated. This system, which includes an innovative sandwich panel and its integrated connections, can be used as structural walls and floors in quickly-assembled postdisaster housing, as well as load-bearing panels for prefabricated modular construction and semipermanent buildings. Panels and connections are composed of a pneumatic fabric formwork, and two 3D high-density polyethylene (HDPE) sheets as the skins, filled with high-density rigid polyurethane (PU) foam as the core. HDPE sheets manufactured with a studded surface considerably enhance stress distribution, buckling performance, and delamination strength of the sandwich panel under various loading conditions. The load-carrying behavior of the system in accordance with some American Society for Testing and Materials (ASTM) standards is presented here. The results show the system satisfies the codes’ criteria regarding semipermanent housing.
Publisher: Informa UK Limited
Date: 02-05-2022
Publisher: Informa UK Limited
Date: 28-10-2021
Publisher: MDPI AG
Date: 10-02-2017
DOI: 10.3390/APP7020168
Publisher: CRC Press
Date: 15-09-2016
Publisher: Elsevier BV
Date: 11-2021
Publisher: MDPI AG
Date: 08-12-2022
Abstract: An association mapping panel consisting of 380 genotypes of chickpea was evaluated for three different years, including 2014–2015, 2015–2016 and 2016–2017, for yield-contributing parameters, including the seed number and seed weight. The AMMI analysis presented mainly concentrated on the seed weight and seed number, which are the two most important yield-contributing traits. The genotypes contributed 93.08% of the total variance, while the interaction effect was comparatively low, with 4.1% for the two traits. AMMI biplot analysis identified IG5986, IG5982, ILC6025 and ICCV14307 as desirable genotypes for the seed weight and IG5893, ILC6891 and IG5856 for the seed number. Identifying stable genotypes would help in strategic planning for yield improvement through component trait breeding.
Publisher: Elsevier BV
Date: 12-2020
Publisher: Elsevier BV
Date: 08-2020
Publisher: CSIRO Publishing
Date: 2023
DOI: 10.1071/WF22124
Publisher: Informa UK Limited
Date: 23-03-2022
Publisher: Elsevier BV
Date: 04-2020
Publisher: Elsevier BV
Date: 09-2023
Publisher: Springer Science and Business Media LLC
Date: 02-02-2021
Publisher: Elsevier BV
Date: 08-2021
Publisher: MDPI AG
Date: 05-12-2022
DOI: 10.3390/FIRE5060208
Abstract: The combined effects of percent slope and fire intensity of a wind driven line fire on an idealized building has been numerically investigated in this paper. The simulations were done using the large eddy simulation (LES) solver of an open source CFD toolbox called FireFOAM. A set of three fire intensity values representing different heat release rates of grassland fuels on different inclined fuel beds have been modeled to analyze the impact of factors, such as fuel and topography on wind-fire interaction of a built area. An idealized cubic structure representing a simplified building was considered downstream of the fire source. The numerical results have been verified with the aerodynamic measurements of a full-scale building model in the absence of fire effects. There is a fair consistency between the modeled findings and empirical outcomes with maximum error of 18%, which acknowledge the validity and precision of the proposed model. The results show that concurrent increase of fire intensity and terrain slope causes an expansion of the surface temperature of the building which is partially due to the increase of flame tilt angle upslope on the hilly terrains. In addition, increasing fire intensity leads to an increase in the flow velocity, which is associated with the low-pressure area observed behind the fire front. Despite limitations of the experimental results in the area of wind-fire interaction the result of the present work is an attempt to shed light on this very important problem of fire behavior prediction. This article is a primary report on this subject in CFD modeling of the collective effects of fire intensity and sloped terrain on wind driven wildfire and its interaction on buildings.
Publisher: Springer Science and Business Media LLC
Date: 27-04-2021
Publisher: ASME International
Date: 27-01-2021
DOI: 10.1115/1.4049462
Abstract: In the current work, an unsteady analysis of methane/air premixed counterflow flame is carried out for different flame conditions and stability parameters considering different strain rate values. The results are presented at unsteady and final steady conditions, and the impact of time-dependent regimes and variations in equivalence ratio, from lean flame to rich one, are analyzed. The governing equations including continuity, momentum, energy, and species are numerically solved with a coupled simple and Piso algorithm. It is also found that when the strain rate value is 1000 s−1, for flame stability, the hydraulic distance of the microchannel must be at least 0.05 mm. Increasing the strain rate results in decreasing the time of stabilizing temperature distribution with a faster quasi-steady equilibrium. The necessity of time-dependent analysis is to comprehend the variations in the main factors of flame structure before reaching the finalized steady-state condition. Therefore, by designing an intermittent automatic valve, if the flow stops in time period of 0.0025 s and starts again, the formation of NO2 and CO2 will be reduced about 50% and 9%, respectively, in a case with a = 100 s−1.
Publisher: MDPI AG
Date: 06-08-2021
DOI: 10.3390/FIRE4030043
Abstract: Fire whirls are a particular case of flame behaviour characterized by a rotating column of fire driven by intense convective heating of air close to the ground. They typically result in a substantial increase in burning rate, temperature, and flame height. Fire whirls can occur in any intense flame environment, including urban areas, particularly within combustible structures, and in wildland or forest fires. Recently, investigations on the creation of fire whirls have attracted much attention. However, most analyses are focused on fire whirl structure, formation, and controlling their unique state. In effect, revisiting the available experimental techniques and numerical simulations used in analyzing fire whirls has received less attention. In this paper, experimental arrangements including empirical set ups and employed fuels are presented in detail. Subsequently, major research progress focused on experimental studies and their laboratory setup is fully discussed, followed by the available numerical simulations, including combustion and turbulence models. Applied methodologies and chosen software in the recent numerical studies are also reviewed exclusively. Finally, the latest findings are featured, and prospective pathways are advised.
Publisher: SAGE Publications
Date: 11-01-2022
DOI: 10.1177/09544062211065988
Abstract: Analysis of unsteady CH 4 /Air counterflow premixed flame into a newly designed plus-shaped channel is investigated in this study. The main objective is to explore the impact of platinum catalytic–coated walls of the combustion chamber on the flame characteristics and pollutant emissions. The OpenFOAM platform is used as a numerical simulation tool to investigate the effects of various equivalence ratios, from the range of lean to rich flames, and passing the reaction time on the counterflow flame characteristics and pollutant emissions of a plus-shaped chamber with the platinum catalyst–coated wall. Results show that the integrated temperature over the proposed geometry with platinum surfaces increases by 18% compared to the non-catalytic case. The numerical simulation revealed that presence of the platinum catalyst on the wall of the chamber has significant impact on reducing the pollutant emissions. This is evident as a 99.5% decrease on NO 2 emission and a 58% reduction on CO 2 formation are found.
Publisher: Springer Science and Business Media LLC
Date: 13-12-2021
DOI: 10.1038/S41560-021-00941-3
Abstract: Large datasets are now ubiquitous as technology enables higher-throughput experiments, but rarely can a research field truly benefit from the research data generated due to inconsistent formatting, undocumented storage or improper dissemination. Here we extract all the meaningful device data from peer-reviewed papers on metal-halide perovskite solar cells published so far and make them available in a database. We collect data from over 42,400 photovoltaic devices with up to 100 parameters per device. We then develop open-source and accessible procedures to analyse the data, providing ex les of insights that can be gleaned from the analysis of a large dataset. The database, graphics and analysis tools are made available to the community and will continue to evolve as an open-source initiative. This approach of extensively capturing the progress of an entire field, including sorting, interactive exploration and graphical representation of the data, will be applicable to many fields in materials science, engineering and biosciences.
Publisher: Springer Science and Business Media LLC
Date: 07-01-2021
Publisher: MDPI AG
Date: 25-12-2020
Abstract: This paper presents a numerical investigation of the impact of a wind-driven surface fire, comparable to a large wildfire, on an obstacle located downstream of the fire source. The numerical modelling was conducted using FireFOAM, a coupled fire-atmosphere model underpinned by a large eddy simulation (LES) solver, which is based on the Eddy Dissipation Concept (EDC) combustion model and implemented in the OpenFOAM platform (an open source CFD tool). The numerical data were validated using the aerodynamic measurements of a full-scale building model in the absence of fire effects. The results highlighted the physical phenomena contributing to the fire spread pattern and its thermal impact on the building. In addition, frequency analysis of the surface temperature fluctuations ahead of the fire front showed that the presence of a building influences the growth and formation of buoyant instabilities, which directly affect the behaviour of the fire’s plume. The coupled fire-atmosphere modelling presented here constitutes a fundamental step towards better understanding the behaviour and potential impacts of large wind-driven wildland fires in wildland-urban interface (WUI) areas.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Informa UK Limited
Date: 09-03-2021
Publisher: Elsevier BV
Date: 07-2023
No related grants have been discovered for Maryam Ghodrat.