ORCID Profile
0000-0002-3122-7617
Current Organisations
RMIT University
,
CSIRO
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Hydrometallurgy | Chemical Engineering Design | Environmental Technologies | Resources Engineering and Extractive Metallurgy
Environmentally Sustainable Plant Production not elsewhere classified | Mining and Extraction of Precious (Noble) Metal Ores | Mining and Extraction of Copper Ores |
Publisher: The Chemical Society of Japan
Date: 05-06-2008
DOI: 10.1246/CL.2008.606
Publisher: Springer Science and Business Media LLC
Date: 09-10-2019
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 12-2008
Publisher: Elsevier BV
Date: 2008
Publisher: American Chemical Society (ACS)
Date: 08-10-2015
Abstract: Understanding the amalgamation mechanisms between mercury and gold is of fundamental interest and importance to many mercury sensing applications. However, there is only limited and piecemeal discussion in the literature of the mechanisms by which Au-Hg amalgams are formed on thin Au films. Here, we present a comprehensive description of a series of morphological changes occurring in a thin polycrystalline Au film during Au-Hg amalgamation investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). These microscopic investigations enable us to offer a coherent explanation for the features and the mechanisms of amalgamation of Hg with Au in the film. We also use an optical technique (fringes of equal chromatic order, FECO) to observe changes in optical thickness and reflectivity of the film. Amalgamation reactions in the film render it inhomogeneous, thus making optical techniques unsuitable as a method for quantitative monitoring of Hg vapor using Au films of this type.
Publisher: Elsevier BV
Date: 04-2008
Publisher: American Chemical Society (ACS)
Date: 06-09-2012
DOI: 10.1021/AC3019944
Abstract: Differences in electrical conductivity provide a basis for identification of different components present at a material surface. Here it is demonstrated that this effect can be exploited for surface analysis of compound materials in solution by making localized alternating current impedance measurements.
Publisher: Elsevier BV
Date: 03-2013
Publisher: Elsevier BV
Date: 08-2016
Publisher: Informa UK Limited
Date: 10-2005
Publisher: Elsevier BV
Date: 05-2012
Publisher: Elsevier BV
Date: 06-2021
Publisher: CSIRO Publishing
Date: 2017
DOI: 10.1071/CH16088
Abstract: An experimental study on copper leaching from Cu1.85S thin films is presented, wherein copper extraction is quantitatively evaluated by changes in film thickness measured by white light interferometric profilometry. Changes in the film morphology and elemental composition, as assessed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, are used to confirm that the loss in film thickness is due to changes in the copper content and that the resultant film species is consistent with the mechanism of copper dissolution. The Cu1.85S thin films were synthesized by chemical bath deposition. The leaching behaviour of copper from the films was investigated in acidic ferric sulfate media at pHs 1, 2, and 3, and pH 1 at redox potentials of ~350–650 mV versus Ag/AgCl in 3 M KCl. The changes in the film thickness and copper sulfur ratio were shown to reflect copper dissolution behaviour from chalcocite. Leaching of the Cu1.85S films demonstrated a greater decrease in film thickness as pH decreased. In addition comparison of the order of reaction as a function of proton concentration in non-oxidative dissolution of Cu1.85S (0.06) and as a function of iron(iii) concentration in ferric oxidation of Cu1.85S (0.40) shows that the proton dissolution reaction is negligible. Leaching of the Cu1.85S films at redox potentials of up to ~476.4 mV versus Ag/AgCl in 3 M KCl produced covellite and demonstrated greater decreases in film thickness with increases in the redox potential. Leaching of the films above ~476.4 mV resulted in the formation of spionkopite and demonstrated a much lesser decrease in film thickness. These results are consistent with Eh-pH diagrams for the Cu–S–H2O system.
Publisher: The Chemical Society of Japan
Date: 05-10-2007
DOI: 10.1246/CL.2007.1286
Publisher: Elsevier BV
Date: 07-2007
DOI: 10.1016/J.JCIS.2007.02.084
Abstract: A simple method for the fabrication of silica nanoparticle film based on the covalent-bonding interaction between carboxylic acid-functionalized silica nanoparticles (SiO(2)-COOH) and amino-terminated silicon wafer was developed. Prior to assembly, silica nanoparticles with an average diameter 80 nm were prepared using the Stöber method, amino-functionalized silica nanoparticles (SiO(2)-NH(2)) were prepared by a silanization with 3-aminopropyltriethoxysilane (APTES), while carboxylic acid-functionalized silica nanoparticles (SiO(2)-COOH) were prepared by a ring opening linker elongation reaction of the amine functions with succinic anhydride, at the same time, amino-terminated silicon wafer (Si-NH(2)) was obtained by self-assembling 3-aminopropyltriethoxysilane, then one layer relative close-packed carboxylic acid-functionalized silica nanoparticles (SiO(2)-COOH) was arranged on silicon wafer through amidation reaction under DCC coupling agent.
Publisher: Elsevier BV
Date: 10-2011
DOI: 10.1016/J.BIORTECH.2011.06.088
Abstract: NMR relaxation measurements can provide a simple means for understanding biological activity of cells in solution with known composition. It has the advantage that it is an in situ, non-intrusive technique, and the acquisition is fast. The iron oxidation ability of Acidithiobacillus ferrooxidans was investigated using NMR relaxation measurements. The transversal relaxation is characterized by a time constant, T₂, which is sensitive to the chemical environment. Fe³⁺ ion has more significant T₂ shortening than Fe²⁺ ion. In the presence of A. ferrooxidans in solutions containing Fe²⁺ ion, T₂ shortening was found with increasing time as the bacteria oxidize Fe²⁺ to Fe³⁺ ions. In the optimal growth medium, the bacteria concentration increased 80 times and high iron oxidation rate was found. In 10 mM K₂SO₄ medium, however, bacteria concentration remained almost unchanged and the iron oxidation rate was significantly lower.
Publisher: Informa UK Limited
Date: 30-01-2023
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 06-2020
Publisher: Elsevier BV
Date: 07-2004
Publisher: Elsevier BV
Date: 03-2004
Publisher: Wiley
Date: 06-1998
DOI: 10.1002/(SICI)1521-4109(199806)10:7<477::AID-ELAN477>3.0.CO;2-S
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.JBIOSC.2018.02.001
Abstract: Biohydrometallurgy is generally considered as a green technology for the recycling of industrial solid waste. In this study, an indigenous fungal strain named Y5 with the ability of high-yielding organic acids was isolated and applied in bioleaching of waste printed circuit boards (PCBs). The strain Y5 was identified as Penicillium chrysogenum by morphological and molecular identification. Meanwhile, we investigated that an optimal set of culturing conditions for the fungal growth and acids secretion was 15 g/L glucose with initial pH 5.0, temperature 25°C and shaking speed 120 rpm in shaken flasks culture. Moreover, three bioleaching processes such as one-step, two-step and spent medium processes were conducted to extract copper from waste PCBs. Spent medium bioleaching showed higher copper extraction percentage and it was 47% under 5%(w/v) pulp density. Transmission electron microscope (TEM) observation combining with energy dispersive analysis of X-rays (EDAX) showed that the leached metal ions did not obviously damage the hypha cells. All above results indicated that P.chrysogenum strain Y5 has the tolerance to metal ions, suggesting its potential in recycling of metals from waste PCBs in industry.
Publisher: Elsevier BV
Date: 05-2001
Publisher: Elsevier BV
Date: 05-2005
Publisher: Elsevier BV
Date: 2011
Publisher: Springer International Publishing
Date: 15-11-2023
Publisher: The Chemical Society of Japan
Date: 05-2004
DOI: 10.1246/CL.2004.602
Publisher: Elsevier BV
Date: 12-2009
Publisher: Wiley
Date: 04-2008
DOI: 10.1002/MRD.20967
Abstract: Transcription profiling of ovarian follicles. Understanding the mechanisms by which a single follicle is selected for further ovulation is important to control fertility in mammals. However, development of new treatments is limited by our poor understanding of molecular mechanisms regulating follicular selection. Our hypothesis is that genes involved in the control of cell proliferation and apoptosis are differentially regulated during follicular selection. Our objective was to identify these new genes. Bovine follicles were collected and gene expression levels were measured using microarrays. First, follicles were allocated to three groups, according to the time spent from the initiation of follicular wave to surgery (24 H, 36 H, and 48-60 H). Fifty-seven genes are differentially expressed at a false discovery rate of 5%. These genes are involved in the control of lipid metabolism (P-value = 0.0005), cell proliferation (0.007), cell death (0.003), cell morphology (0.003), and immune response (0.003). Follicles were also grouped into four categories, according to the expected time of deviation (early deviation 8 mm, mid-deviation 8.5 mm, late deviation 9 mm, dominant follicles >or=10 mm). One hundred and twenty eight genes are differentially expressed between these four groups, including genes involved in cell proliferation (0.00002), cell death (0.0006), cell-to-cell signaling (0.003), cell morphology (0.003), lipid metabolism (0.0004), and immune response (0.00007). The expression levels of 10 genes were confirmed using quantitative real time PCR. As expected, we identified new differentially regulated genes involved in the control of cell growth and apoptosis. We also discovered a potential role for immune cells, and in particular macrophages, in follicular selection.
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 05-2015
Publisher: Royal Society of Chemistry (RSC)
Date: 2009
DOI: 10.1039/B818633B
Abstract: Multiple facet supported alumina nanowires are produced very efficiently in a very short time via high field anodization upon modification with perfluorosilane, the surface becomes super-repellent towards a broad range of liquids, which includes (salted) water, water emulsion, common organic liquids like glycerol and alkanes, and a variety of lubrication oils including ionic liquids, poly(alpha-olefin), polydimethylsiloxane oils etc.
Publisher: Elsevier BV
Date: 2015
Publisher: Springer Science and Business Media LLC
Date: 30-08-2023
DOI: 10.1007/S13384-022-00567-8
Abstract: Although ‘child safety’ is now a national policy priority in Australia, there is little research exploring the practices in schools that contribute to children and young people’s felt sense of safety and wellbeing. Drawing on a mixed-method Australian Research Council (ARC) Discovery project, this article presents findings from interviews with school staff ( N = 10), leaders ( N = 5) and nine focus groups with students ( N = 58), in primary and secondary schools in three Australian states (New South Wales, Victoria and South Australia). We employ relational ethics, recognition theory and the theory of practice architectures to explore practices at school that support student wellbeing and safety. The findings contribute significantly to understanding the ‘bundled’ nature of current practices and the conditions that enable and constrain these. Close attention to these findings is critical as schools seek to operationalise the National Child Safe Principles and refine ongoing safeguarding procedures. The findings have informed the development of an online survey that is currently testing, on a much larger scale, which elements of ethical practice are most positively associated with students’ safety, wellbeing and recognition at school.
Publisher: Elsevier BV
Date: 03-2008
Publisher: Elsevier BV
Date: 12-2023
Publisher: American Chemical Society (ACS)
Date: 30-11-2006
DOI: 10.1021/JP062340Y
Abstract: Self-assembled monolayers (SAMs) of three thiol compounds formed on mercury are investigated by a combination of cyclic voltammetry, electrocapillary curves, and a novel method of measuring electrical double-layer properties. The last method involves a modified surface force apparatus in which a flat mica surface is pressed down toward a fixed mercury drop held beneath it, while both are immersed in aqueous electrolyte solution. Optical interference measurements are made of the mica-mercury separation as a function of electrical potential applied to the mercury, which yields information on the double-layer interaction between the two surfaces. Mercury is decorated by SAMs of 11-mercapto-1-undecanoic acid, which is shown to bring negative charge to the mercury/aqueous interface due to dissociation of the carboxylic acid groups 11-mercapto-1-undecanol, which although it is uncharged changes the dipole potential of the interface and 1-undecanethiol, which likewise changes the dipole potential, but by a different amount. The difference between the changes in dipole potential (90 mV) can be related to the different terminal groups of these two SAMs, -CH3 compared to -OH, that are in contact with the aqueous phase.
Publisher: The Electrochemical Society
Date: 2018
DOI: 10.1149/2.0461813JES
Publisher: Elsevier BV
Date: 02-2016
Publisher: American Chemical Society (ACS)
Date: 19-04-2002
DOI: 10.1021/LA011389M
Publisher: Elsevier BV
Date: 07-2008
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 06-2017
DOI: 10.1016/J.JBIOSC.2016.12.017
Abstract: To seek a feasible technique for processing waste printed circuit boards (PCBs), pretreatment of PCBs by table separation and further bioleached by moderate thermophiles in a stirred tank reactor were investigated. The shaking table separation, conducted after grinding and sieving of PCBs, produced two fractions: metal-rich parts (RPCBs), which is more suitable for pyrometallurgy process than untreated PCBs, and metal-poor parts (PPCBs) with only 8.83% metals was then bioleached by a mixed culture of moderate thermophiles effectively. After adaptation, the mixed culture could tolerate 80 g/L PPCBs. The bioleaching results showed that metals recovery was 85.23% Zn, 76.59% Cu and 70.16% Al in only 7 days. Trace Pb and Sn were detected in the leachate because of precipitating. The microorganism community structure was analyzed by lified ribosomal DNA restriction analysis. Two moderately thermophilic bacteria species were identified as Leptospirillum ferriphilum and Acidithiobacillus caldus. Furthermore, uncultured Thermoplasmatales archaeon was also detected in the leaching system. It was also shown that moderate thermophiles revealed best bioleaching ability when compared with mesophiles and the mixture of mesophiles and moderate thermophiles. Finally, we designed a two-stage process model according to the present study to achieve semi-industrial waste PCBs recycling and economic feasibility analysis indicated that the process was profitable.
Publisher: Informa UK Limited
Date: 31-12-2008
Publisher: IOP Publishing
Date: 25-04-2008
DOI: 10.1088/0957-4484/19/22/225607
Abstract: Silver sulfide (Ag(2)S) nanocrystals were successfully synthesized by the thermal treatment of the single source precursors, silver dialkyldithiophosphates (Ag[S(2)P(OC(n)H(2n+1))(2)]), under mild reaction conditions. The size of Ag(2)S nanocrystals with regular shape can be controlled in the range of tens of nanometers by adjusting critical parameters, such as the carbon number of the substitute alkyl, the solvent and the reaction temperature. Electron diffraction and x-ray powder diffraction confirmed the orthorhombic phase of the Ag(2)S nanocrystals. The as-prepared Ag(2)S nanocrystals have an inorganic-organic core-shell structure, in which Ag(2)S nanocrystals are the inorganic core and the organic modifiers, consisting of oleylamine and dialkyldithiophosphate, are the shell. The organic modifiers were anchored to the surface of Ag(2)S nanocores by their active groups of -NH(2) and -SPS- , respectively, and their direct-alkyl chains spread to the outside. So, these as-prepared Ag(2)S nanocrystals can self-assemble to form orderly two-dimensional arrays easily, and they disperse in some non-polar solvents stably.
Publisher: Wiley
Date: 03-2004
DOI: 10.1002/APP.20121
Publisher: Elsevier BV
Date: 11-2023
Publisher: Informa UK Limited
Date: 09-10-2022
Publisher: Informa UK Limited
Date: 16-05-2023
Publisher: IOP Publishing
Date: 03-04-2002
Publisher: Springer Science and Business Media LLC
Date: 05-05-2015
DOI: 10.1007/S00284-015-0817-7
Abstract: Sulfate adenylyltransferase gene and 4Fe-4S ferredoxin gene are the key genes related to sulfur and iron oxidations during bioleaching system, respectively. In order to better understand the bioleaching and microorganism synergistic mechanism in chalcopyrite bioleaching by mixed culture of moderate thermophiles, expressions of the two energy metabolism genes and community dynamics of free and attached microorganisms were investigated. Specific primers were designed for real-time quantitative PCR to study the expression of these genes. Real-time PCR results showed that sulfate adenylyltransferase gene was more highly expressed in Sulfobacillus thermosulfidooxidans than that in Acidithiobacillus caldus, and expression of 4Fe-4S ferredoxin gene was higher in Ferroplasma thermophilum than that in S. thermosulfidooxidans and Leptospirillum ferriphilum. The results indicated that in the bioleaching system of chalcopyrite concentrate, sulfur and iron oxidations were mainly performed by S. thermosulfidooxidans and F. thermophilum, respectively. The community dynamics results revealed that S. thermosulfidooxidans took up the largest proportion during the whole period, followed by F. thermophilum, A. caldus, and L. ferriphilum. The CCA analysis showed that 4Fe-4S ferredoxin gene expression was mainly affected (positively correlated) by high pH and elevated concentration of ferrous ion, while no factor was observed to prominently influence the expression of sulfate adenylyltransferase gene.
Publisher: Elsevier BV
Date: 12-2014
Publisher: Wiley
Date: 08-2008
Publisher: Trans Tech Publications, Ltd.
Date: 08-2017
DOI: 10.4028/WWW.SCIENTIFIC.NET/SSP.262.261
Abstract: To improve the efficiency of sustainable recovery of valuable resources (such as copper, gold, uranium), advanced technologies of electrochemistry, surface chemistry and materials characterization, such as Synchrotron X ray-absorption spectroscopy (XAS), X-Ray photoelectron spectroscopy (XPS), and in situ X-ray Diffraction (XRD) have been employed to investigate the interactions between microbes and sulfide minerals in situ to gain a detailed understanding of the chemical reaction mechanisms operating in bioleaching. It has been demonstrated that alternating current Scanning Electrochemical Microscopy (ac-SECM) allows for straightforward characterization of sulfide mineral s les in aqueous solution. With the technology localized electrochemical properties of the mineral surface including the surface current mapping can be achieved. Robust chemical sensors have been developed for real time, in-situ monitoring of key leaching process parameters.
Publisher: Informa UK Limited
Date: 11-07-2023
Publisher: Elsevier BV
Date: 2004
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JCIS.2019.01.027
Abstract: A strategy is described for the direct preparation of Au nanoparticles (AuNPs) on a Fe-based support, coated with porous carbon (PC), via pyrolysis of an AuCN functionalised Prussian Blue (PB) metal organic framework (MOF). The composite starting material was prepared with an even distribution of AuCN on the surface via galvanic exchange of PB with a gold salt in solution. The resulting structures after pyrolysis were shown to be active Au-based nanomaterials for model applications including catalysis (4-nitrophenol reduction) and electroanalysis (arsenic (III) detection), suggesting broad application where Au nanoparticles are required at a liquid-solid interface. The Fe based support was seen to consist of Fe, Fe
Publisher: Elsevier BV
Date: 2010
Publisher: Elsevier BV
Date: 07-2007
Publisher: Royal Society of Chemistry (RSC)
Date: 2008
DOI: 10.1039/B812277F
Abstract: The present work reports on a systematic study of the swelling/collapse transition of three anionic polymer brushes bearing carboxylate, phosphate and sulfonate side groups via AFM measurement. Time scale of conformation change process can be approximately evaluated directly. All the three brushes in their sodium salt forms stretch away from the surface in pure water, as a result of charge repulsion and uptake of water. The collapse of weak brushes has two ways: normal charge screening and precipitation (strong ion pairing), depending on the types of cations that have different coordination capabilities with anionic groups. Alkali metal ions can make brushes shrink only at relatively high concentrations following a gradually increased charge screening mechanism. The brushes collapsed in this way can be restored by simply flushing with water. However, multivalent cations can irreversibly collapse brushes more easily even under very low concentrations (<10(-3) mol L(-1)). The brushes cannot be restored with simple water rinsing even for strong sulfonate containing brushes. In this case, recovery can be achieved by ion exchange in concentrated salt solution, which facilitates transit from strong ion pairing to less strong charge screening and then flushing with water. Alternatively, the multivalent ion can be extracted with chelating reagent of low concentration (10 mM EDTA). As the chelating agent doesn't affect the conformation of brushes, the brushes are one-step recovered directly, much more efficient than with high concentration electrolyte which usually requires extra water rinsing to remove excess salt inside brushes. The interaction between anions in the brushes and metal ions represents a model system to profoundly understand the mechanism of bio-mimic motions and how muscle works. In this regard, the present study provides useful information for the development of polyelectrolyte brushes based ion sensor and ion powered nanoactuators.
Publisher: Elsevier BV
Date: 07-2007
DOI: 10.1016/J.JCIS.2007.02.044
Abstract: Micro-patterned films obtained from micro-contact printing (microCP) method are often challenged by site selectivity limitation. For applications site-selectivity requires improvements. In this paper a site-selective deposition of the rutile TiO2 thin films on patterned SnO2 film, which was formed on the patterned octadecyltrichlorosilane (OTS) SAMs through microCP is described. The depositions proceeded in an environmentally friendly aqueous solution (SnCl4 and peroxotitanium acidic solution) at a lower temperature (80 degrees C). It is shown that the OTS SAMs has a good selectivity deposition for SnO2 particles, which was mainly dominated by the heterogeneous nucleation mechanism. The SnO2 layer had a structure-directing effect for growth of the rutile TiO2, which was usually formed above 600 degrees C. The patterned films were characterized by a variety of techniques, including ellipsometry, optical microscopy, SEM, AFM, XPS, and DLS to determine the thicknesses, topologies, microstructures, chemical compositions of the films, particle sizes and zeta potentials of the titanium particles.
Publisher: Elsevier BV
Date: 06-2019
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.CHEMOSPHERE.2021.133185
Abstract: A high bioflocculant-producing bacterial strain was identified and named Bacillus subtilis ZHX3. Single-factor experiments suggested that 10 g/L starch and 5 g/L yeast extract were optimal for strain ZHX3 to produce bioflocculant MBF-ZHX3. The maximum flocculating rate reached 95.5%, and 3.14 g/L product was extracted after 3 days of cultivation. MBF-ZHX3 was mainly composed of polysaccharides (77.2%) and protein (14.8%). The polysaccharides contained 28.9% uronic acid and 3.7% amino sugar. Rhamnose, arabinose, galactose, glucose, mannose, and galacturonic acid in a molar ratio of 0.35:1.83:3.09:12.66:0.46:3.81 were detected. MBF-ZHX3 had a molecular weight of 10,028 Da and contained abundant groups (-OH, CO, >PO, C-O-C) contributing to flocculation. Adsorption and bridging was considered as the main flocculation mechanism. MBF-ZHX3 was more effective in decolorizing dyes, removing heavy metals and flotation reagents compared to polyacrylamide. The results implied that MBF-ZHX3 has the potential to substitute polyacrylamide in wastewater treatment because of its excellent biological and environmental benefits.
Publisher: Elsevier BV
Date: 12-2008
Publisher: Elsevier BV
Date: 06-2014
DOI: 10.1016/J.BIORTECH.2014.03.163
Abstract: The shift of microbial community under the adjustment of different pH was analyzed by denaturing gradient gel electrophoresis (DGGE). The results indicated, at initial pH 1.0, 2.0 and 3.0, the copper extraction in 22 days amounted to 84.6%, 88.2% and 77.5%, respectively however, when the initial pH was 2.0, processing pH was adjusted to 1.0 and 3.0 on day 16, the copper extraction in 32 days was 85% and 62.6%, respectively. DGGE analysis showed Acidithiobacillus caldus, Leptospirillum ferriphilum, Sulfobacillus thermosulfidooxidans and Ferroplasma thermophilum existed in bioleaching systems. At initial pH 1.0 and 3.0, S. thermosulfidooxidans and A. caldus were main microorganisms. While at initial pH 2.0, L. ferriphilum, A. caldus and S. thermosulfidooxidans were always detected. At processing pH 1.0 and 3.0, the adjustment of pH greatly inhibited the growth of L. ferriphilum it was also found microbial community would recover gradually only if pH stimulation did not fatally affect microorganisms.
Publisher: Elsevier BV
Date: 2004
Publisher: Wiley
Date: 15-08-2003
Publisher: Elsevier BV
Date: 07-2022
Publisher: No publisher found
Date: 2011
DOI: 10.1016/J.HYDROMET.20HTTPS://DOI.ORG/10.HTTPS://DOI.ORG/10.012
Publisher: The Chemical Society of Japan
Date: 08-2006
DOI: 10.1246/CL.2006.850
Publisher: Elsevier BV
Date: 02-2005
Publisher: Elsevier BV
Date: 02-2009
Publisher: Elsevier BV
Date: 02-2014
Publisher: Elsevier BV
Date: 28-09-2008
Publisher: Springer Science and Business Media LLC
Date: 03-05-2019
DOI: 10.1007/S11356-019-05234-7
Abstract: Extracellular polymeric substances (EPSs) extracted from fungal mycelium by four chemical methods (NaOH, H
Publisher: Elsevier BV
Date: 11-2008
Publisher: Royal Society of Chemistry (RSC)
Date: 1998
DOI: 10.1039/A802278J
Publisher: Elsevier BV
Date: 09-2010
DOI: 10.1016/J.BIORTECH.2010.04.003
Abstract: A mixed culture of moderately thermophiles showed good performance in bioleaching of chalcopyrite. Its community structure was investigated by lified ribosomal DNA restriction analysis. The result shows that Leptospirillum ferriphilum and Acidithiobacillus caldus were the predominant bacteria and Ferroplasma thermophilum, the only archaea, could be always detected during bioleaching. Therefore, real-time PCR assay was performed to monitor these microorganisms' dynamics in the solution and on the mineral surface. It is shown that both in the solution and on the mineral surface, A. caldus was the dominant species at the early stage and L. ferriphilum was the predominant species at the later stage. The amount of the same species exhibited different variation trends in the solution and on the mineral surface. The amount of attached L. ferriphilum increased faster than that of the free one, and the amount of attached F. thermophilum kept at a stable level while the free one increased rapidly at the end.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 2008
Publisher: Elsevier BV
Date: 02-2021
Publisher: SAGE Publications
Date: 22-09-2019
Abstract: Chalcopyrite is the most abundant, but also one of the most refractory, copper sources. One way to enhance chalcopyrite’s electrochemical dissolution is by mixing it with pyrite. To understand how and to what extent pyrite affects chalcopyrite’s electrochemical dissolution at different potentials, the electrochemical behaviors of chalcopyrite, pyrite, and chalcopyrite–pyrite couples in pH 1.8 H 2 SO 4 were studied by potentiodynamic and electrochemical impedance spectroscopy. Potentiodynamic curves showed their different electrochemical reaction states and electrode surface characteristics. From open-circuit potential to 470 mV (vs saturated calomel electrode), chalcopyrite–pyrite was passivated with Cu 1− x Fe 1− y S 2 [Formula: see text] from 470 to 580 mV, trans-passive dissolution occurred, and in the passive region, Cu 1− x Fe 1− y S 2 transformed into Cu 1− x− z S 2 from 580 to 700 mV was an active region and a pseudo-passive region was formed with CuS when the potential was above 700 mV. The smaller charge transfer resistance and passive resistance, as well as the smaller inductive relaxation, revealed how and to what extent the coupled pyrite accelerated the electrochemical dissolution of chalcopyrite.
Publisher: The Chemical Society of Japan
Date: 05-05-2007
DOI: 10.1246/CL.2007.686
Publisher: Royal Society of Chemistry (RSC)
Date: 02-11-2001
DOI: 10.1039/B107831N
Abstract: Radical chain transfer to bonded thiol groups and surface re-initiated polymerization resulted in ultra-thin polymer films.
Publisher: Elsevier BV
Date: 07-2015
Publisher: Wiley
Date: 03-12-2003
Publisher: Informa UK Limited
Date: 05-01-2009
Publisher: Science China Press., Co. Ltd.
Date: 2004
DOI: 10.1360/03YB0092
Publisher: Elsevier BV
Date: 10-2018
Publisher: Trans Tech Publications, Ltd.
Date: 08-2017
DOI: 10.4028/WWW.SCIENTIFIC.NET/SSP.262.53
Abstract: In the present study, we investigated the bioleaching of arsenopyrite with or without pyrite by moderate thermophiles. In both chemical leaching and bioleaching, the addition of pyrite decreased the leaching rate of arsenopyrite. The arsenic speciation and minerology changes in the residues were analysed by X-ray Absorption Near Edge Structure (XANES) Spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and powder X-ray Diffraction (XRD). The XANES analysis showed no detectable arsenopyrite in the final residues from the experiments without pyrite. However, there was still 21.7% of arsenic species presented as arsenopyrite after bioleaching, when the initial arsenopyrite yrite ratio was 1:5. The XPS analysis revealed there was only As(V) on the surface of most of the residues, except on one chemically leached s le where As(III) was found.
Publisher: Elsevier BV
Date: 05-2020
Publisher: The Electrochemical Society
Date: 2018
DOI: 10.1149/2.1261714JES
Publisher: Elsevier BV
Date: 03-2014
Publisher: Elsevier BV
Date: 07-2022
Publisher: American Chemical Society (ACS)
Date: 15-06-2007
DOI: 10.1021/JP070166N
Publisher: MDPI AG
Date: 13-07-2009
Publisher: Springer Science and Business Media LLC
Date: 29-11-2021
Publisher: Informa UK Limited
Date: 13-07-2022
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 2024
Publisher: Elsevier BV
Date: 10-2008
DOI: 10.1016/J.JCIS.2008.06.041
Abstract: The article reports on a very simple method to fabricate superhydrophobic surfaces with Cu-Zn alloy via changing the local oxygen concentration and formation of oxygen difference cell, which can be readily realized by covering or contacting the Cu-Zn alloy surface with a glass slide. This superhydrophobic film comes from the formation of a flower-like hierarchical structure due to the accelerated alloy etching. In contrast, the white film grown in the un-covered area showed a much lower hydrophobicity due to its different morphology. These superhydrophobic surfaces or superhydrophobic-hydrophobic surfaces are expected to find applications in making self-cleaning alloy surface, in metal anticorrosion, and in biomineralization, etc.
Publisher: Elsevier BV
Date: 12-2021
Publisher: Elsevier BV
Date: 05-2011
Publisher: Informa UK Limited
Date: 03-1997
Publisher: Springer Science and Business Media LLC
Date: 15-11-2022
Publisher: American Chemical Society (ACS)
Date: 16-12-2000
DOI: 10.1021/JP991391A
Publisher: Springer Science and Business Media LLC
Date: 27-06-2009
Publisher: Oxford University Press (OUP)
Date: 16-05-2017
DOI: 10.1111/JAM.13467
Abstract: To explore the distribution disciplinarian of alginate on the chalcopyrite concentrate surface during bioleaching. The evolution of Sulfobacillus thermosulfidooxidans secreting alginate during bioleaching of chalcopyrite concentrate was investigated through gas chromatography coupled with mass spectrometry (GC-MS) and confocal laser scanning microscope (CLSM), and the critical synthetic genes (algA, algC, algD) of alginate were analysed by real-time polymerase chain reaction (RT-PCR). The GC-MS analysis results indicated that there was a little amount of alginate formed on the mineral surface at the early stage, while increasing largely to the maximum value at the intermediate stage, and then kept a stable value at the end stage. The CLSM analysis of chalcopyrite slice showed the same variation trend of alginate content on the mineral surface. Furthermore, the RT-PCR results showed that during the early stage of bioleaching, the expressions of the algA, algC and the algD genes were all overexpressed. However, at the final stage, the algD gene expression decreased in a large scale, and the algA and algC decreased slightly. This expression pattern was attributed to the fact that algA and algC genes were involved in several biosynthesis reactions, but the algD gene only participated in the alginate biosynthesis and this was considered as the key gene to control alginate synthesis. The content of alginate on the mineral surface increased largely at the beginning of bioleaching, and remained stable at the end of bioleaching due to the restriction of algD gene expression. Our findings provide valuable information to explore the relationship between alginate formation and bioleaching of chalcopyrite.
Publisher: Wiley
Date: 2009
Abstract: Stable silver colloids were prepared using polyethylene glycol (PEG) as an environment friendly reduction agent and stabilizer, and with H2O as solvent. The Ag colloids were characterized by UV/VIS spectroscopy, transmission electron microscopy (TEM), and atom force microscopy (AFM). TEM and AFM of the s le showed uniform and monodispersive particle distribution in the colloids. The particle size is found to be less than 10 nm. The antibacterial activity of the Ag colloids was also studied. The results showed that the s le had high antibacterial activity toward Gram-positive and Gram-negative bacteria, and fungi.
Publisher: Elsevier BV
Date: 05-2005
Publisher: Elsevier BV
Date: 08-2009
Publisher: Elsevier BV
Date: 03-2020
Publisher: Springer Science and Business Media LLC
Date: 24-08-2014
Publisher: Springer Science and Business Media LLC
Date: 27-03-2014
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2006
DOI: 10.1142/S0219581X06005303
Abstract: In this paper, we present the results of using alkane derivatives to assist in the adsorption of planar molecules by employing 1-bromohexadecane( C 16 Br ) and phthalocyanine (Pc) as ex les. Their assembly behaviors have been well resolved on the observed STM images. The observations presented in this work demonstrate that single molecular arrays of Pc can be obtained with a template of C 16 Br on highly oriented pyrolytic graphite (HOPG) substrate surface to allow high-resolution STM studies. Binary mixtures of different molar ratios were also observed. By adjusting the molar ratio of Pc to C 16 Br to about 1:3–1:4, uniform assembly can become dominative on the surface. The resulting high stability and the well ordered assembly are attributed to the increased adsorption barrier of alkanes. This approach could be adapted to the studies of other molecules to observe molecular features and could be helpful in obtaining two-dimensional assemblies of monodispersed molecules, especially planar molecules.
Publisher: Elsevier BV
Date: 04-2016
Publisher: Elsevier BV
Date: 02-2011
Publisher: Elsevier BV
Date: 04-2005
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 05-2008
Publisher: Elsevier BV
Date: 11-2017
Publisher: Informa UK Limited
Date: 09-08-2015
DOI: 10.1080/08927014.2015.1073720
Abstract: To obtain a fundamental understanding of the population behaviour of Acidithiobacillus ferrooxidans at chalcopyrite and pyrite surfaces, the early stage attachment behaviour and biofilm formation by this bacterium on chalcopyrite (CuFeS2) and pyrite (FeS2) were studied by optical microscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS) and electron backscatter diffraction (EBSD). The results indicate there was no significant difference in selectivity of bacterial attachment between chalcopyrite and pyrite. However, the result of ToF-SIMS analysis suggests that the surface of the pyrite was covered more extensively by biofilm than that of the chalcopyrite, which may indicate more extracellular polymeric substances (EPS) formation by bacterial cells growing on pyrite. EBSD and optical image analysis indicated that selectivity of bacterial attachment to chalcopyrite was not significantly affected by crystal orientation. The results also suggest that the bacterial population in defective areas of chalcopyrite was significantly higher than on the polished surfaces.
Publisher: American Chemical Society (ACS)
Date: 23-01-2007
DOI: 10.1021/CM062549O
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 09-2019
DOI: 10.1016/J.COLSURFB.2019.05.051
Abstract: Purpureocillium lilacinum can promote the biomineralization of jarosite by secreting extracellular polymeric substances (EPS), but the detailed mechanism is not clear. In this study, the biosynthesis process of jarosite induced by P. lilacinum Y3 and hypha cell surface characterization were investigated. X-ray diffraction (XRD) analysis indicated that P. lilacinum Y3 could induce the formation of jarosite crystal and enhance mineralization kinetics. The kinetic and isotherm models confirmed that the metal ions transferring from the solution to the mycelium surface was controlled by diffusion process and the active interfacial sites on hypha cell surface played a pivotal role in the biomineralization process. Furthermore, transmission electron microscopy (TEM) pictures illustrated that the P. lilacinum Y3 mainly induced the generation of mineral precipitate extracellularly, but not intracellularly. Three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectrum results further revealed the extracellular compounds such as fulvic-acid-like and protein-like substances participated in the mineralization process.
Publisher: Elsevier BV
Date: 06-2023
Publisher: Elsevier BV
Date: 07-2007
Publisher: Elsevier BV
Date: 08-2009
Publisher: Elsevier BV
Date: 05-2009
Publisher: Elsevier BV
Date: 1999
Publisher: Springer Science and Business Media LLC
Date: 20-02-2018
DOI: 10.1007/S00284-018-1453-9
Abstract: Iron-oxidizing Acidithiobacillus spp. are applied worldwide in biomining industry to extract metals from sulfide minerals. They derive energy for survival through Fe
Publisher: Springer Science and Business Media LLC
Date: 09-2002
Abstract: Polydimethylsiloxane (PDMS) films were prepared on silicon wafers by spin coating. The tribological properties of the PDMS films sliding against AISI-52100 steel ball were investigated with a dynamic static friction coefficient measurement apparatus in a ball-on-plate configuration. It was found that crosslinking, end grafting, and chemical characteristics of the substrate surfaces combined to play an important role in keeping the films' stability and improving the friction-reduction and wear-resistant properties. It was also noted that crosslinked PDMS films on hydroxylated substrates exhibited the most stable friction coefficient and the longest antiwear life, while a friction coefficient below 0.01 was observed for the crosslinked PDMS films on hydrophobic substrates. The latter might be attributed to the weak interaction at the interface of PDMS layer and the self-assembled monolayer. The friction coefficient appeared to be velocity dependent. At higher sliding velocities, the films showed more stable and smaller friction coefficients this might be attributed to the shear thinning effect.
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.JCIS.2008.11.066
Abstract: Positive and negative micropatterned copper sulfide thin films were successfully fabricated through chemical bath deposition methods. The thin films were deposited on patterned Si substrates with two different self-assembled monolayers (SAMs), i.e., NH(2)/CH(3) and NH(2)/OH terminated silane, respectively. Under an optimal depositing condition, the copper sulfide thin films were selectively deposited on NH(2) regions. The resultant Cu(2)S crystal films, in positive and negative circle patterns, respectively, were verified by SEM, XPS, XRD spectra. UV-vis spectrum analysis demonstrated that the prepared Cu(2)S films exhibited high optical transmission in the visible light regions (vis) and near-infrared region (NIR), and a low band gap of 2.48 eV.
Publisher: Elsevier BV
Date: 06-2020
Publisher: Springer Science and Business Media LLC
Date: 05-2020
Publisher: International Union of Crystallography (IUCr)
Date: 30-04-2015
DOI: 10.1107/S1600577515007596
Abstract: Figures 7 and 8 of the article by Clancy et al. [(2015), J. Synchrotron Rad. 22 , 366–375] are corrected.
Publisher: Elsevier BV
Date: 04-2023
Publisher: No publisher found
Date: 2018
Publisher: International Union of Crystallography (IUCr)
Date: 31-01-2015
DOI: 10.1107/S1600577514027659
Abstract: This paper describes the quantitative measurement, by in situ synchrotron X-ray diffraction (S-XRD) and subsequent Rietveld-based quantitative phase analysis and thickness calculations, of the evolution of the PbO 2 and PbSO 4 surface layers formed on a pure lead anode under simulated copper electrowinning conditions in a 1.6 M H 2 SO 4 electrolyte at 318 K. This is the first report of a truly in situ S-XRD study of the surface layer evolution on a Pb substrate under cycles of galvanostatic and power interruption conditions, of key interest to the mining, solvent extraction and lead acid battery communities. The design of a novel reflection geometry electrochemical flow cell is also described. The in situ S-XRD results show that β-PbO 2 forms immediately on the anode under galvanostatic conditions, and undergoes continued growth until power interruption where it transforms to PbSO 4 . The kinetics of the β-PbO 2 to PbSO 4 conversion decrease as the number of cycles increases, whilst the amount of residual PbO 2 increases with the number of cycles due to incomplete conversion to PbSO 4 . Conversely, complete transformation of PbSO 4 to β-PbO 2 was observed in each cycle. The results of layer thickness calculations demonstrate a significant volume change upon PbSO 4 to β-PbO 2 transformation.
Publisher: Springer Science and Business Media LLC
Date: 08-2009
Abstract: A simple and convenient method for preparing visible light response photocatalyst polypyrrole/TiO 2 (PPy/TiO 2 ) nanocomposite was developed. The products were characterized by x-ray diffraction, transmission electron microscopy, atomic force microscopy, ultraviolet-visible, and Fourier transform infrared techniques. The results indicated that the nanohybrid was composed of anatase TiO 2 and PPy and exhibited an enhanced visible light-capturing ability. Average diameters of TiO 2 and PPy/TiO 2 were 18 and 35 nm, respectively. The photocatalytic activity of the nanocomposite was evaluated by the degradation of methyl orange under visible light irradiation. In the presence of PPy/TiO 2 nanocomposite, the degradation efficiency of methyl orange of 95.54% could be obtained under visible light irradiation within 120 min. The apparent rate constant was 2.19 × 10 −2 , which was better than that Degussa P25 nano-TiO 2 . The sensitization mechanism of PPy/TiO 2 photocatalyst was discussed briefly.
Publisher: Wiley
Date: 03-07-2017
Publisher: Elsevier BV
Date: 07-2008
Publisher: Elsevier BV
Date: 04-2011
DOI: 10.1016/J.BIORTECH.2011.01.038
Abstract: A mesophilic acidophilic consortium was enriched from acid mine drainage s les collected from several uranium mines in China. The performance of the consortium in column bioleaching of low-grade uranium embedded in granite porphyry was investigated. The influences of several chemical parameters on uranium extraction in column reactor were also investigated. A uranium recovery of 96.82% was achieved in 97 days column leaching process including 33 days acid pre-leaching stage and 64 days bioleaching stage. It was reflected that indirect leaching mechanism took precedence over direct. Furthermore, the bacterial community structure was analyzed by using Amplified Ribosomal DNA Restriction Analysis. The results showed that microorganisms on the residual surface were more erse than that in the solution. Acidithiobacillus ferrooxidans was the dominant species in the solution and Leptospirillum ferriphilum on the residual surface.
Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 07-2013
Publisher: Elsevier BV
Date: 11-2007
DOI: 10.1016/J.JCIS.2007.06.080
Abstract: Measurements are presented of the effective complex refractive index of a layer of gold nanoparticles adsorbed to a silicon wafer at low coverages. The measurements were made by means of variable-angle ellipsometry, and correlated with nanoparticle coverage determined from atomic force microscope images. The analysis establishes the effective refractive index of a uniform layer whose thickness equals the nanoparticle diameter. A simple empirical relationship is obtained for real component of refractive index as a function of the fractional nanoparticle coverage regardless of the nanoparticle size. The imaginary component also follows a simple relationship but only up to a certain coverage, above which it increases rapidly. These relationships may be useful in other contexts such as chemical or biosensors in which the nanoparticle coverage could be inferred from optical measurements such as ellipsometry, surface plasmon resonance spectroscopy, reflectometry, or interferometry.
Publisher: Elsevier BV
Date: 11-2003
Publisher: Elsevier BV
Date: 05-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8RA03060J
Abstract: We proved fungal extracellular polymeric substances promoted biomineralization and the formation of P–O–Fe played a key role in this process.
Publisher: Elsevier BV
Date: 08-1998
DOI: 10.1016/S0039-9140(97)00300-7
Abstract: In the present paper, N,N'-dinaphthyl-N,N'-diphenyl-3,6-dioxaoctanediamide acts as a specific reagent for enhancing the fluorescence intensity of Eu(III) complex with thenoyl trifluoroacetone (TTA), the spectrofluorimetric determination of trace amounts of Eu(III) based on the above system was carried out and its luminescence mechanism was studied. The excitation and emission wavelengths are 343.6 and 613.3 nm, respectively. The fluorescence intensities vary linearly with the concentration of europium(III) in the range 3.647x10(-3)-3.039 mug ml(-1) for the original fluorescence with a detection limit down to 2.279x10(-4) mug ml(-1) and the standard deviation is 0.063 mug ml(-1) for 10 times measurements, and in the range 7.598x10(-4)-0.0243 mug ml(-1) (SD=0.035 for 15 times measurements), 0.06078-0.6100 mug ml(-1) (SD=0.52 for 10 times measurements) for the first derivative fluorescence signal with a detection limit down to 8.566x10(-5) mug ml(-1). The interferences of other rare earths and some of inorganic ions are described. This method is a direct, rapid, selective and sensitive analytical method for the determination of trivalent europium in rare earth ore s les and high purity of rare earth oxides.
Publisher: Elsevier BV
Date: 05-2002
Publisher: Elsevier BV
Date: 03-2018
Publisher: Informa UK Limited
Date: 20-07-2022
Publisher: Elsevier BV
Date: 07-2022
Publisher: Elsevier BV
Date: 06-2005
Publisher: Springer Science and Business Media LLC
Date: 05-2020
Location: Australia
Location: No location found
Location: China
Start Date: 01-2018
End Date: 02-2024
Amount: $360,000.00
Funder: Australian Research Council
View Funded Activity