Chemistry Center

Dutton Park, Australia

Chemistry Center

Dutton Park, Australia
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Popovic A.,University of Belgrade | Djordjevic D.,Chemistry Center | Relic D.,University of Belgrade
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2013

Serbia obtains most of its energy from low-quality lignite, thus being one of the world's largest producers of coal ash per capita. In order to examine the distribution of trace and major elements in the ash and the pollution potential of the ash itself, six combined samples of filter ash, obtained by lignite combustion in the "Nikola Tesla A" Power Plant, were subjected to a five-phase sequential extraction. Analysis of obtained concentrations revealed the short- and long-term pollution capacity of different elements as well as the influence ionic strength of river water may have to the pollution of neighboring waters. © 2013 Copyright Taylor and Francis Group, LLC.

Popovic A.,University of Belgrade | Djordjevic D.,Chemistry Center
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2015

In order to establish associations of trace and major elements in dump coal ash taken from active, currently filled cassette of "Nikola Tesla A" power plant dump (Obrenovac near Belgrade, Serbia), eight samples of dump ash were subjected to a five-step sequential extraction, comprising of the following phases: distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, acidic solution of H2O2, and 6 M solution of HCl. The obtained concentrations were subjected to correlation analysis, and results compared to those obtained by analysis of leached concentrations from fresh, lignite filter coal ash. © Taylor and Francis Group, LLC.

Popovic A.,University of Belgrade | Djordjevic D.,Chemistry Center
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2015

Eight samples each of coal ash taken from active, currently filled, and passive, previously filled cassettes of "Nikola Tesla A" power plant dump (Obrenovac near Belgrade, Serbia) were subjected to a sequential extraction, comprising of the following five phases: distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, acidic solution of H2O2, and 6 M solution of HCl. Leached concentrations were discussed from the standpoint of their environmental significance, keeping in mind the processes occurring during and after coal ash transport to the dump, as well as the concentrations washed from the original filter lignite ash. © Taylor and Francis Group, LLC.

Relic D.,University of Belgrade | Crossed D Signorcrossed D Signevic D.,Chemistry Center | Popovic A.,University of Belgrade | Jadranin M.,Chemistry Center | Polic P.,University of Belgrade
Environmental Monitoring and Assessment | Year: 2010

Thirty-five alluvial sediments of the River Danube and 12 groundwater samples were taken within the Pančevo Oil Refinery (Serbia). The results for groundwater samples exceed European primary drinking water standards for Fe (obtained results, >200 μg/l) and Mn (obtained results, >50 μg/l), while the levels of the trace metals are below the thresholds for drinking water quality. Sediments were treated by sequential extraction procedure with five different solutions, each having a higher extraction capacity than the previous one. We also wanted to determine the possible relationships among trace metals and between sediment properties and elemental concentrations. These solutions partitioned metals into CH3COONH4 extractable (F1); HCl carbonate extractable and NH2OH•HCl easily reducible (F2); (NH4)2C2O4/H2C 2O4 moderately reducible (F3); H2O 2-HNO3 organic/sulfide extractable fractions (F4); and HCl acid-soluble residue (F5). The sum of trace metals Ni, Pb, Cu, and Zn associated with the first two fractions (exchangeable, carbonate, and easily reducible) is significant and extremely important because it represents the proportion of heavy metals that can be easily remobilized by changes in environmental conditions such as pH, redox potential, salinity, etc. Sediments located nearer the groundwater flow are exposed to stronger groundwater fluctuation and had a higher quantity of amorphous and less stable substrates of trace metals. Principal component analysis was used to understand and visualize the associations between the trace metals and certain geological forms within analyzed sediments. The observed association between Cr with total sulfur and Mn from the acid-soluble residue could indicate that Cr is in the form of reduced, less toxic Cr(III), which is from the ecochemical point of view very important. © 2009 Springer Science+Business Media B.V.

Bondonno C.P.,University of Western Australia | Yang X.,Shaanxi Normal University | Croft K.D.,University of Western Australia | Considine M.J.,University of Western Australia | And 6 more authors.
Free Radical Biology and Medicine | Year: 2012

Flavonoids and nitrates in fruits and vegetables may protect against cardiovascular disease. Dietary flavonoids and nitrates can augment nitric oxide status via distinct pathways, which may improve endothelial function and lower blood pressure. Recent studies suggest that the combination of flavonoids and nitrates can enhance nitric oxide production in the stomach. Their combined effect in the circulation is unclear. Here, our objective was to investigate the independent and additive effects of flavonoid-rich apples and nitrate-rich spinach on nitric oxide status, endothelial function, and blood pressure. A randomized, controlled, crossover trial with healthy men and women (n = 30) was conducted. The acute effects of four energy-matched treatments (control, apple, spinach, and apple + spinach), administered in random order, were compared. Measurements included plasma nitric oxide status, assessed by measuring S-nitrosothiols + other nitrosylated species (RXNO) and nitrite, blood pressure, and endothelial function, measured as flow-mediated dilatation of the brachial artery. Results are means and 95% CI. Relative to control, all treatments resulted in higher RXNO (control, 33 nmol/L, 26, 42; apple, 51 nmol/L, 40, 65; spinach, 86 nmol/L, 68, 110; apple + spinach, 69 nmol/L, 54, 88; P < 0.01) and higher nitrite (control, 35 nmol/L, 27, 46; apple, 69 nmol/L, 53, 90; spinach, 99 nmol/L, 76, 129; apple + spinach, 80 nmol/L, 61, 104; P < 0.01). Compared to control, all treatments resulted in higher flow-mediated dilatation (P < 0.05) and lower pulse pressure (P < 0.05), and apple and spinach resulted in lower systolic blood pressure (P < 0.05). No significant effect was observed on diastolic blood pressure. The combination of apple and spinach did not result in additive effects on nitric oxide status, endothelial function, or blood pressure. In conclusion, flavonoid-rich apples and nitrate-rich spinach can independently augment nitric oxide status, enhance endothelial function, and lower blood pressure acutely, outcomes that may benefit cardiovascular health. © 2011 Elsevier Inc.

Popovic A.,University of Belgrade | Djordjevic D.,Chemistry Center | Relic D.,University of Belgrade | Mihajlidi-Zelic A.,University of Belgrade
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2011

Six composite filter fly, bottom, and dump ash samples, each taken from Obilic power plant, were subjected to the sequential extraction procedure comprised of five phases. Iron silicates, alumosilicates not containing iron and silicates not containing iron nor aluminum, as well as a form of aluminum not containing silicon, are established as substrates dissolved in the fifth phase of extraction. Alumosilicates and mixed oxides of iron and manganese are dissolved in the third phase of extraction. Association patterns and distribution of trace and major elements with substrates as well as environmental consequences of such distribution were established and discussed. © 2011 Copyright Taylor and Francis Group, LLC.

News Article | December 16, 2016

FAU chemists are developing an artificial intelligence application which can predict which molecule structures will produce or suppress specific odours. The Volkswagen Foundation has granted the project 96,100 euros of funding for the next 18 months as part of its 'Experiment!' programme. It's something that everyone has experienced. You buy an inflatable exercise ball to improve your posture at your desk, but you have to leave it outside for the first three days until it no longer stinks. Or you pick up a packaged salami at the supermarket and it smells more like plastic than beechwood smoke. Researchers at FAU's Computer Chemistry Center (CCC) are working to make undesirable smells in packaging and products a thing of the past. To this end, they are developing an artificial intelligence application that can predict with great certainty which molecule combinations neutralise or specifically foster odours. The project is called 'CLINGON: Computer Linguistics of Olfaction' and will receive close to 96,100 euros of funding over the next year and a half from the Volkswagen Foundation. 'We will be spending most of our time working at the computer, not in the laboratory,' said Dr. Thilo Bauer. Together with Dr. Tatyana Shubina from CCC and Prof. Dr. Andrea Büttner from the Chair of Food Chemistry, Bauer has developed a database which pools knowledge about the molecular structure of fragrances and aromas: 'We use computer linguistics for this purpose. It's similar to processing language; the programme is supposed to understand odour molecules as a sentence in which the molecule fragments represent the words. The combination of the fragments determines the meaning of the sentence, or in our case, the smell.' In the near future the FAU chemists hope to use pattern recognition to make reliable predictions about the creation of odours, thus making time-consuming trial and error experiments unnecessary - and not only for purposes of avoiding certain odours, but also for creating scents. 'In the cosmetics industry many thousands of molecules are synthesised and tested for their scent every year. Only a few of them ever make it onto the market,' said Thilo Bauer. 'Our programme could help to make the development of new products more effective and resource-efficient.' The Volkswagen Foundation uses its funding initiative 'Experiment!' to foster ambitious research projects which fundamentally challenge established ideas, strive to establish unconventional hypotheses, methods or technologies or strike out in wholly new directions in research. Researchers from the natural sciences, engineering and life sciences have the opportunity to test the practicability of their concept during the exploratory phase, which is limited to 100,000 euros in funding over 18 months. The Foundation explicitly accepts failure of the funded projects as a result. Since the initiative was established in November 2012, 67 proposals have been approved.

Lewis S.E.,James Cook University | Olley J.,Griffith University | Furuichi T.,Chemistry Center | Sharma A.,Chemistry Center | Burton J.,Chemistry Center
Earth and Planetary Science Letters | Year: 2014

Understanding the key processes controlling the delivery, deposition and fate of sediments on continental shelves is critical to appreciate the evolution of coasts and estuaries and to interpret geological sequences. This study presents radiocarbon and Optically Stimulated Luminescence (OSL) ages of sediment cores collected from key locations offshore from the Burdekin River, Australia, the largest single source of sediment delivered to the Great Barrier Reef (GBR) lagoon. The ages show variable sediment accumulation rates at the different locations that coincide with the Holocene avulsion history of the Burdekin River. Our data show that most fine sediment (<63 μm) delivered from the Burdekin River is retained within 50 km of the mouth, a finding that contrasts previous studies which postulated that fine sediments are advected northwards via longshore drift processes. The pairing of radiocarbon and OSL ages provides insights on resuspension regimes operating on the inner shelf of the GBR. It was thought that turbidity on inshore GBR coral reefs and seagrass meadows has increased as a result of increased erosion in the adjacent catchment from agricultural development. Our data show that the age of the sediments in Cleveland Bay (derived from the radiocarbon ages from shell and organic material) can be several thousand years older than when the sediment was last deposited (OSL ages). However, the increased turbidity could conceivably be caused from 'new biologically-produced sediment' (i.e. particulate organic matter) as a result of increased nutrient export to the GBR. We suggest that the composition of sediment in resuspension events before and after the wet season be analysed to examine whether newly delivered organic-rich sediment can affect coral reefs and seagrass meadows. © 2014.

Coates-Marnane J.,Griffith University | Olley J.,Griffith University | Burton J.,Chemistry Center | Grinham A.,University of Queensland
Science of the Total Environment | Year: 2016

Drought-breaking floods pose a risk to coastal water quality as sediments, nutrients, and pollutants stored within catchments during periods of low flow are mobilized and delivered to coastal waters within a short period of time. Here we use subtidal surface sediment surveys and sediment cores to explore the effects of the 2011 Brisbane River flood on trace metals zinc (Zn), lead (Pb), copper (Cu), nickel (Ni), chromium (Cr), manganese (Mn), and phosphorus (P) deposition in Moreton Bay, a shallow subtropical bay in eastern Australia. Concentrations of Zn, Cu, and Pb in sediments in central Moreton Bay derived from the 2011 flood were the highest yet observed in the Bay. We suggest flushing of metal rich sediments which had accumulated on the Brisbane River floodplain and in its estuary during the preceding 10 to 40 years of low flows to be the primary source of this increase. This highlights the importance of intermittent high magnitude floods in tidally influenced rivers in controlling metal transport to coastal waters in subtropical regions. © 2016

Coates-Marnane J.,Griffith University | Olley J.,Griffith University | Burton J.,Chemistry Center | Sharma A.,Chemistry Center
Estuarine, Coastal and Shelf Science | Year: 2016

Understanding processes that govern the transport and distribution of terrestrial sediments to and within bays is critical for interpreting the drivers of long-term changes in these ecosystems. On the east coast of Australia increased soil erosion and sediment delivery following extensive land clearing in the contributing catchments, associated with European settlement, is highlighted as a key driver of the decline of numerous nearshore habitats including seagrass meadows and in-shore coral reefs. Here we use optical, radiocarbon and radionuclide dating to estimate mass accumulation rates and type of terrestrial sedimentation in central Moreton Bay during the Holocene. We compare the long-term rates of infilling within the central basin with the recent past and show a 3-9 fold increase in sediment accretion over the last 100 years compared to the long term (last ∼ 1500 to 3000 yrs) average. Infilling during the Holocene is not spatially uniform, with preferential deposition occurring within the now submerged palaeochannels of the Brisbane and Pine rivers. We suggest that modern turbidity regimes in Moreton Bay are the result of the compounded effect of both a historical increase in fine sediment supply and a rapid decline in the effective storage capacity of the basin. © 2016 Elsevier Ltd.

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