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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
A General Asymmetric Aldol Reaction Of Silyl Ketene Acetals Derived From Simple Esters To Aryl Alpha-Ketoesters, Brian Pagenkopf, Julie Le Engers
A General Asymmetric Aldol Reaction Of Silyl Ketene Acetals Derived From Simple Esters To Aryl Alpha-Ketoesters, Brian Pagenkopf, Julie Le Engers
Chemistry Publications
No abstract provided.
Extreme Ultraviolet Polarimetry With Laser-Generated High-Order Harmonics: Characterization Of Uranium, Nicole Brimhall
Extreme Ultraviolet Polarimetry With Laser-Generated High-Order Harmonics: Characterization Of Uranium, Nicole Brimhall
Theses and Dissertations
We developed an extreme ultraviolet (EUV) polarimeter, which employs laser-generated high-order harmonics as the light source. This relatively high-flux, directional EUV source has available wavelengths between 10 nm and 47 nm with easily rotatable linear polarization. The polarimeter has allowed us to characterize the optical constants of materials that may be useful for EUV optics. The instrument has a versatile positioning system and a spectral resolution of about 180, and we have demonstrated that reflectance as low as 0.1% can be measured repeatably at EUV wavelengths. We investigate the high harmonic source used for polarimetry measurements by documenting the spatial …
Factors Controlling The Geochemical Partitioning Of Trace Metals In Estuarine Sediments, Edward Burton, Ian Phillips, Darryl Hawker
Factors Controlling The Geochemical Partitioning Of Trace Metals In Estuarine Sediments, Edward Burton, Ian Phillips, Darryl Hawker
Associate Professor Edward D Burton
The geochemical partitioning of trace metals in sediments is of great importance in risk assessment and remedial investigation. Selected factors that may control the partitioning behavior of Cu, Pb and Zn in non-sulfidic, estuarine sediments were examined with the use of combined sorption curve—sequential extraction analysis. This approach, which has not been previously used to examine estuarine sediments, allowed determination of sorption parameters for Cu, Pb and Zn partitioning to individual geochemical fractions. Partitioning behavior in sulfidic sediments was also determined by sequentially extracting Cu, Pb, and Zn from synthetic sulfide minerals and from natural sediment and pure quartz sand …
Estimating Sludge Loadings To Land Based On Trace Metal Sorption In Soil: Effect Of Dissolved Organo-Metallic Complexes, Edward Burton, Darryl Hawker, M Redding
Estimating Sludge Loadings To Land Based On Trace Metal Sorption In Soil: Effect Of Dissolved Organo-Metallic Complexes, Edward Burton, Darryl Hawker, M Redding
Associate Professor Edward D Burton
This paper describes the results of research examining the effect of dissolved organo-metallic complexes of copper (Cu) and zinc (Zn) from sewage sludge leachate on sorption by a humic-gley soil A-horizon, and the influence of such complexes on resultant sludge loading estimates. Sorption was described with Linear, Freundlich or Langmuir equations, and compared between a sample of sludge leachate (containing 97.4% of Cu and 63.2% of Zn as dissolved organo-metallic complexes) and a reference solution (which mimicked the leachate, except for a lack of dissolved organic material). This comparison revealed that dissolved organo-metallic complexes significantly depressed Cu and Zn sorption …
Recovery Of Fathead Minnows (Pimephales Promelas) Following Episodic Copper Exposure: A Biochemical, Physiological, Individual, And Population Perspective, Holly Zahner
All Dissertations
The US EPA utilizes the Biotic Ligand Model (BLM) when developing site-specific water-quality criteria for copper. The BLM was calibrated using toxicity data from fixed duration continuous exposures (48 or 96h LC50). However, exposures of copper in natural aquatic systems typically vary in concentration, duration, and may occur multiple times over the life-span of an organism. Additionally, organisms will experience periods in copper free water, potentially allowing them to detoxify and recover homeostasis. Yet, the BLM framework does not consider brief exposures (<24h), multiple exposures, latent responses, or organism recovery, potentially resulting in an inaccurate assessment of exposure toxicity. A recently proposed physiologically-based addition to the BLM will extend the applicability of the framework to brief, multiple pulse copper exposures. Thus, the overall goal of this research was to characterize the recovery of larval Pimephales promelas following episodic copper exposure at a biochemical, physiological, individual, and population level.
The response of whole-body sodium, whole-body Na+/K+-ATPase, and whole-body carbonic anhydrase in larval P. promleas was quantified …
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 …
Beta-Diketone And -Ketoenamine-Based Organic Building Blocks For Porous Metal Organic-Materials, Yoseph Solomon Marcos
Beta-Diketone And -Ketoenamine-Based Organic Building Blocks For Porous Metal Organic-Materials, Yoseph Solomon Marcos
LSU Doctoral Dissertations
This dissertation focuses on synthesis of multifunctional â-diketone and â-ketoenamine ligands and their reaction with metal ions, mainly Cu2+. Several new bi-, tri-, and tetrafunctional organosilicon â-diketone building blocks with â-diketone groups at approx. 109° (tetrahedral) were successfully synthesized. New thiophene based bifunctional ligands where the â-diketones are at about 145° are also reported here. We also prepared a range of new aryl-â-ketoenamines from their analogous â-diketones in very high yield using a simple microwave-assisted procedure. Reactions of organosilicon tris(â-diketone)s LH3 with Cu2+ were explored quite intensively. These ligands form metal-organic-polyhedra (MOPs) that are soluble in organic solvents, and insoluble …
A Study Of Growth And Breakdown Of Passive Film On Copper Surface By Electrochemical Impedance Spectroscopy, Amtul Naseer, Athar Yaseen Khan
A Study Of Growth And Breakdown Of Passive Film On Copper Surface By Electrochemical Impedance Spectroscopy, Amtul Naseer, Athar Yaseen Khan
Turkish Journal of Chemistry
Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry were used to investigate the oxide layer formed on a copper disc electrode and the changes that took place when treated potentiostatically in the range of -0.3 V to 0.9 V in aqueous buffer solution of pH 9.2. Equivalent circuits were used to model the response of the electrode, initially at equilibrium to an applied potential. These circuits were proposed for different potential ranges in order to illustrate the Cu/oxide/electrolyte system and its properties in terms of 2 interfaces. A criterion for the applicability of equivalent circuit models was discussed. Changes in the …
Electronic And Structural Properties Of Molybdenum Thin Films As Determined By Real Time Spectroscopic Ellipsometry, J. D. Walker, H. Khatri, V. Ranjan, Jian Li, R. W. Collins, S. Marsillac
Electronic And Structural Properties Of Molybdenum Thin Films As Determined By Real Time Spectroscopic Ellipsometry, J. D. Walker, H. Khatri, V. Ranjan, Jian Li, R. W. Collins, S. Marsillac
Electrical & Computer Engineering Faculty Publications
Walker, J.D., Khatri, H., Ranjan, V., Li, J., Collins, R.W., & Marsillac, S. (2009). Electronic and structural properties of molybdenum thin films as determined by real-time spectroscopic ellipsometry. Applied Physics Letters, 94(14). doi: 10.1063/1.3117222