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Articles 1 - 16 of 16
Full-Text Articles in Physical Sciences and Mathematics
Gas-Particle Partitioning Of Atmospheric Hg(Ii) And Its Effect On Global Mercury Deposition, H M. Amos, D J. Jacob, C D. Holmes, Jenny A. Fisher, Q Wang, R M. Yantosca, E S. Corbitt, E Galarneau, A P. Rutter, M S. Gustin, A Steffen, J J. Schauer, J A. Graydon, V L. St Louis, R W. Talbot, E S. Edgerton, Y Zhang, E N. Sunderland
Gas-Particle Partitioning Of Atmospheric Hg(Ii) And Its Effect On Global Mercury Deposition, H M. Amos, D J. Jacob, C D. Holmes, Jenny A. Fisher, Q Wang, R M. Yantosca, E S. Corbitt, E Galarneau, A P. Rutter, M S. Gustin, A Steffen, J J. Schauer, J A. Graydon, V L. St Louis, R W. Talbot, E S. Edgerton, Y Zhang, E N. Sunderland
Faculty of Science - Papers (Archive)
Atmospheric deposition represents a major input of mercury to surface environments. The phase of mercury (gas or particle) has important implications for its removal from the atmosphere. We use long-term observations of reactive gaseous mercury (RGM), particle-bound mercury (PBM), fine particulate matter (PM2.5), and temperature at five sites in North America to derive an empirical gas-particle partitioning relationship log10(K-1) = (10 ± 1) − (2500 ± 300)/T where K = (PBM/PM2.5)/RGM with PBM and RGM in common mixing ratio units, PM2.5 in μg m−3, and T in …
The Effect Of Field-Collected Biofilms On The Toxicity Of Copper To A Marine Microalga (Tetraselmis Sp.) In Laboratory Bioassays, Jacqueline L. Levy, Jenny L. Stauber, Steven A. Wakelin, Dianne F. Jolley
The Effect Of Field-Collected Biofilms On The Toxicity Of Copper To A Marine Microalga (Tetraselmis Sp.) In Laboratory Bioassays, Jacqueline L. Levy, Jenny L. Stauber, Steven A. Wakelin, Dianne F. Jolley
Faculty of Science - Papers (Archive)
Standard algal growth rate inhibition bioassays can lack environmental realism and may over- or underestimate metal bioavailability in natural systems. In aquatic environments, algal species interact with other biota, including other algae, bacteria and biofilms. In this work, the feasibility of incorporating marine biofilms into 72h algal growth inhibition toxicity tests was explored. The effects of copper on Tetraselmis sp. were tested in the absence and presence of characterised field-collected biofilms. We hypothesised that the addition of biofilm would prevent copper toxicity to the alga primarily through interactions of the metal with other cells and biofilm exudates. The sensitivity …
Effect Of Two Types Of Tree Guards (With And Without Weed Control) On Tree Seedling Establishment, Brenton Ladd, Stephen P. Bonser, Joshua R. Larsen
Effect Of Two Types Of Tree Guards (With And Without Weed Control) On Tree Seedling Establishment, Brenton Ladd, Stephen P. Bonser, Joshua R. Larsen
Faculty of Science - Papers (Archive)
No abstract provided.
The Effect Of Fuel Age On The Spread Of Fire In Sclerophyll Forest In The Sydney Region Of Australia., Ross A. Bradstock, Owen F. Price
The Effect Of Fuel Age On The Spread Of Fire In Sclerophyll Forest In The Sydney Region Of Australia., Ross A. Bradstock, Owen F. Price
Faculty of Science - Papers (Archive)
We investigated the effect of fuel age on the truncation of spread of unplanned fires using a set of 1473 patches in the Sydney region of Australia. Twenty-two percent of patches derived from prescribed fire experienced a subsequent unplanned fire within 5 years, compared with 42% of patches derived from unplanned fires. Among those encounters, the subsequent unplanned fire stopped at the leading edge of 18% of prescribed patches and 11% of unplanned patches. In comparison, the subsequent fire stopped somewhere in the patch for 44% of both prescribed and unplanned fires. Overall, there was a 10% chance that a …
Detection And Quantification Of Tear Phospholipids And Cholesterol In Contact Lens Deposits: The Effect Of Contact Lens Material And Lens Care Solution, Jennifer Saville, Zhenjun Zhao, Mark D.P. Willcox, Stephen J. Blanksby, Todd W. Mitchell
Detection And Quantification Of Tear Phospholipids And Cholesterol In Contact Lens Deposits: The Effect Of Contact Lens Material And Lens Care Solution, Jennifer Saville, Zhenjun Zhao, Mark D.P. Willcox, Stephen J. Blanksby, Todd W. Mitchell
Faculty of Science - Papers (Archive)
PURPOSE. To examine the deposition of tear phospholipids and cholesterol onto worn contact lenses and the effect of lens material and lens care solution. METHODS. Lipids were extracted from tears and worn contact lenses using 2: 1 chloroform: methanol and the extract washed with aqueous ammonium acetate, before analysis by electrospray ionization tandem mass spectrometry (ESI-MS/MS). RESULTS. Twenty-three molecular lipids from the sphingomyelin (SM) and phosphatidylcholine (PC) classes were detected in tears, with total concentrations of each class determined to be 5 +/- 1 pmol/mu L (similar to 3.8 mu g/mL) and 6 +/- 1 pmol/mu L (similar to 4.6 …
Using Lidar To Assess The Effect Of Fire And Floods On Upland Peat Bogs, Waterfall Gully, Mount Lofty Ranges, South Australia, Javier Leon Patino, Solomon Buckman, Robert P. Bourman, Rowena Morris, Katherine C. Brownlie
Using Lidar To Assess The Effect Of Fire And Floods On Upland Peat Bogs, Waterfall Gully, Mount Lofty Ranges, South Australia, Javier Leon Patino, Solomon Buckman, Robert P. Bourman, Rowena Morris, Katherine C. Brownlie
Faculty of Science - Papers (Archive)
A flood exceeding the 100 year average recurrence interval in November 2005 led to the failure of an upland peat bog in Waterfall Gully. The area is prone to severe bushfire and flood events and the control dam at the base of First Falls was filled with sediment sourced from Wilson Bog. A resistant quartzite bar at Fourth Falls has formed a natural constriction point against which burnt logs and debris have collected following previous fire events forming a natural dam resulting in sediment/peat accumulation upstream. The failure of the bog was inevitable as the vegetative material in the log-jam …
The Effect Of Preparation Conditions And Biopolymer Dispersants On The Properties Of Swnt Buckypapers, Jenny Boge, Luke J. Sweetman, Marc In Het Panhuis, Stephen F. Ralph
The Effect Of Preparation Conditions And Biopolymer Dispersants On The Properties Of Swnt Buckypapers, Jenny Boge, Luke J. Sweetman, Marc In Het Panhuis, Stephen F. Ralph
Faculty of Science - Papers (Archive)
The effect of varying preparation conditions on the properties of buckypapers made using single-walled carbon nanotubes (SWNTs) was systematically investigated. Changing the sonication time, final dispersion volume or membrane filter used to prepare SWNT-Triton X-100 buckypapers all generally had only a small influence on the density, thickness, contact angle and electrical conductivity of the resulting material. More significant changes were noted when the effects of variations in the above preparation conditions on the mechanical properties and surface morphology of SWNT-Triton X-100 buckypapers were investigated. However, the largest changes in properties were found when various biopolymers (bovine serum albumin, lysozyme, gellan …
The Effect Of Bacteria On The Sensitivity Of Microalgae To Copper In Laboratory Bioassays, Jacqueline Levy, Jenny L. Stauber, Steven A. Wakelin, Dianne F. Jolley
The Effect Of Bacteria On The Sensitivity Of Microalgae To Copper In Laboratory Bioassays, Jacqueline Levy, Jenny L. Stauber, Steven A. Wakelin, Dianne F. Jolley
Faculty of Science - Papers (Archive)
Although single-species laboratory toxicity tests with microalgae are sensitive and highly reproducible, they lack environmental realism. Interactions between algae and their associated bacteria, either in the plankton or in biofilms, may alter algal sensitivity to contaminants, which are not mimicked in laboratory toxicity tests. This study investigated the effects of simple algal-bacterial relationships on the sensitivity of laboratory-cultured algae to copper using 72-h algal growth-rate inhibition bioassays. Four species of microalgae were used, two isolates of each; a strain of algae with no microscopically visible and no culturable bacteria present (operationally defined as axenic) and a non-axenic strain. The four …
Management Implications Of Recent Research Into The Effect Of Bitou Bush Invasion, Kristine O. French, Emilie-Jane Ens, Carl Gosper, Elizabeth Lindsay, Tanya J. Mason, Ben Owers, Natalie A. Sullivan
Management Implications Of Recent Research Into The Effect Of Bitou Bush Invasion, Kristine O. French, Emilie-Jane Ens, Carl Gosper, Elizabeth Lindsay, Tanya J. Mason, Ben Owers, Natalie A. Sullivan
Faculty of Science - Papers (Archive)
We review recent research into the impact of bitou bush (Chrysanthemoides monilifera spp. rotundata (DC.) Norl.) on coastal ecosystems which suggest this weed is having widespread impacts on ecosystem services, flora and fauna. Increased decomposition rates and altered nutrient cycling accompany changes in plant community structure and composition. Changes in invaded habitats influence invertebrate and bird assemblages. We summarise research that shows that the establishment phase of seedlings is the key phase where bitou bush outcompetes native species through both resource and interference competition mechanisms.
Reactions Of The Hydroperoxide Anion With Dimethyl Methylphosphonate In An Ion Trap Mass Spectrometer: Evidence For A Gas Phase A-Effect, Andrew M Mcanoy, Martin Paine, Stephen J. Blanksby
Reactions Of The Hydroperoxide Anion With Dimethyl Methylphosphonate In An Ion Trap Mass Spectrometer: Evidence For A Gas Phase A-Effect, Andrew M Mcanoy, Martin Paine, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
The gas phase degradation reactions of the chemical warfare agent (CWA) simulant, dimethyl methylphosphonate (DMMP), with the hydroperoxide anion (HOO–) were investigated using a modified quadrupole ion trap mass spectrometer. The HOO– anion reacts readily with neutral DMMP forming two significant product ions at m/z 109 and m/z 123. The major reaction pathways correspond to (i) the nucleophilic substitution at carbon to form [CH3P(O)(OCH3)O]– (m/z 109) in a highly exothermic process and (ii) exothermic proton transfer. The branching ratios of the two reaction pathways, 89% and 11% respectively, indicate that the …
Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon
Effect Of Protein Stabilization On Charge State Distribution In Positive- And Negative Ion Electrospray Ionization Mass Spectra, Stephen J. Watt, Margaret Sheil, Jennifer L. Beck, Pavel Prosselkov, Gottfried Otting, Nicholas E. Dixon
Faculty of Science - Papers (Archive)
Changes in protein conformation are thought to alter charge state distributions observed in electrospray ionization mass spectra (ESI-MS) of proteins. In most cases, this has been demonstrated by unfolding proteins through acidification of the solution. This methodology changes the properties of the solvent so that changes in the ESI-MS charge envelopes from conformational changes are difficult to separate from the effects of changing solvent on the ionization process. A novel strategy is presented enabling comparison of ESI mass spectra of a folded and partially unfolded protein of the same amino acid sequence subjected to the same experimental protocols and conditions. …
Sensitivity Of Marine Microalgae To Copper: The Effect Of Biotic Factors On Copper Adsorption And Toxicity, Jacqueline Levy, Jenny L. Stauber, Dianne F. Jolley
Sensitivity Of Marine Microalgae To Copper: The Effect Of Biotic Factors On Copper Adsorption And Toxicity, Jacqueline Levy, Jenny L. Stauber, Dianne F. Jolley
Faculty of Science - Papers (Archive)
Microalgae are sensitive indicators of environmental change and, as the basis of most freshwater and marine ecosystems, are widely used in the assessment of risk and development of environmental regulations for metals. However, interspecies differences in sensitivity to metals are not well understood. The relationship between metal-algal cell binding and copper sensitivity of marine microalgae was investigated using a series of 72-h growth-rate inhibition bioassays and short-term (1-h) uptake studies. A range of marine algae from different taxonomic groups were screened to determine whether copper adsorption to the cell membrane was influenced by biotic factors, such as the ultrastructure of …
Effect Of Overlying Water Ph, Dissolved Oxygen, Salinity And Sediment Disturbances On Metal Release And Sequestration From Metal Contaminated Marine Sediments, Clare Atkinson, Dianne F. Jolley, Stuart L. Simpson
Effect Of Overlying Water Ph, Dissolved Oxygen, Salinity And Sediment Disturbances On Metal Release And Sequestration From Metal Contaminated Marine Sediments, Clare Atkinson, Dianne F. Jolley, Stuart L. Simpson
Faculty of Science - Papers (Archive)
Experiments were undertaken to examine the key variables affecting metal release and sequestration processes in marine sediments with metal concentrations in sediments reaching up to 86, 240, 700, and 3000mgkg1 (dry weight) for Cd, Cu, Pb and Zn, respectively. The metal release and sequestration rates were affected to a much greater extent by changes in overlying water pH (5.58.0) and sediment disturbance (by physical mixing) than by changes in dissolved oxygen concentration (38mgl1) or salinity (1545 practical salinity units). The physical disturbance of sediments was also found to release metals more rapidly than biological disturbance (bioturbation). The rate of oxidative …
Palaeovolcanic Forcing Of Short-Term Dendroisotopic Depletion: The Effect Of Decreased Solar Intensity On Irish Oak, N. Ogle, Christian Turney, R.M. Kalin, L. O'Donnell, C.J. Butler
Palaeovolcanic Forcing Of Short-Term Dendroisotopic Depletion: The Effect Of Decreased Solar Intensity On Irish Oak, N. Ogle, Christian Turney, R.M. Kalin, L. O'Donnell, C.J. Butler
Faculty of Science - Papers (Archive)
The climatic effects of historical volcanic eruptions are well documented in the literature. What are less certain however, are the effects of eruptions on more distant environments, particularly vegetation. Here we present sub-annual δ13C records from two high-resolution Irish oak (Quercus spp.) chronologies that span the Laki (Grímsvötn) 1783–84 and Tambora 1815 eruptions. In both instances, a significant depletion in δ13C is recorded within the trees following the eruption (∼1.8‰). Historical meteorological datasets from observatories near to the trees sampled demonstrate that the shifts in carbon isotopic content cannot be accounted for by changes in …
A Study On Solid Waste Management System Of Dhaka City Corporation: Effect Of Composting And Landfill Location, Faisal Ibney Hai, M. Ashraf Ali
A Study On Solid Waste Management System Of Dhaka City Corporation: Effect Of Composting And Landfill Location, Faisal Ibney Hai, M. Ashraf Ali
Faculty of Science - Papers (Archive)
This study has analyzed the generation and characteristics of solid waste in Dhaka city, along with the associated environmental impacts and existing solid waste management practices. Special focus was given on the effect of composting on final disposal of solid waste and effect of landfill site location on transportation cost. An estimate of the future generation rate indicates that the present generation rate of 3500 tons/day may exceed 30 thousand tons/day by the year 2020.The mixed waste dumped at dumping sites is characterized with high organic content and high moisture content (about 80% and 50-70% by weight, respectively). According to …
Effect Of Organic Solvents On The Separation Of Benzoic Acids By Capillary Electrophoresis, Young J. Lee, William E. Price, Margaret Sheil
Effect Of Organic Solvents On The Separation Of Benzoic Acids By Capillary Electrophoresis, Young J. Lee, William E. Price, Margaret Sheil
Faculty of Science - Papers (Archive)
The effect of organic modifiers on the separation of a number of closely related isomeric benzoic acids by capillary electrophoresis is described. It is shown that while a single modifier concentration cannot help resolve the entire electropherogram, organic modifiers do significantly enhance the resolution of parts of the separation system by comparison with 40 mmol l-1 phosphate buffer. The effects on separation and retention times are discussed in terms of the effects on electroosmotic flow and the electrophoretic mobilities of the charged solutes. The effects were found to be modifier specific, although the trends were in the same direction (ie., …