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Articles 27181 - 27210 of 34731

Full-Text Articles in Physical Sciences and Mathematics

Application Of Pyrolysis-Gc/Ms For Rapid Assessment Of Organic Contamination In Sediments From Barcelona Harbor, Michael A. Kruge, Albert Permanyer Jan 2004

Application Of Pyrolysis-Gc/Ms For Rapid Assessment Of Organic Contamination In Sediments From Barcelona Harbor, Michael A. Kruge, Albert Permanyer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Pyrolysis-GC/MS is advantageous as a tool for rapid sediment contamination assessment because of the small sample size required, minimal sample preparation, and its ability to detect a wide variety of organic pollutants as well as naturally-occurring biological materials. Py-GC/MS was applied, together with determination of organic carbon, and major and minor element concentrations, to evaluate potentially contaminated sediments in the port of Barcelona (Spain) and the adjacent Llobregat River delta. Detected contaminant markers, most evident in the Old Port (Port Vell) area, included hopanes and alkylated PAHs (petroleum), sterenes (sewage), C16-C19 phenylalkanes (detergents) and parent …


Superionicity In Na3Po4: A Molecular Dynamics Simulation, Wei-Guo Yin, Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy Jan 2004

Superionicity In Na3Po4: A Molecular Dynamics Simulation, Wei-Guo Yin, Jianjun Liu, Chun-Gang Duan, Wai-Ning Mei, Robert W. Smith, John R. Hardy

Physics Faculty Publications

Fast ionic conduction in solid Na3PO4 is studied by use of molecular dynamics simulation based on the modified Lu-Hardy approach. We obtain reasonable agreement with experiment for the structural transition and diffusion of the sodium ions. All the sodium ions are found to contribute comparably to the high ionic conductivity. The results of the simulation are discussed in terms of the relative magnitude of the two proposed transport mechanisms: percolation and paddle-wheel. It appears to us that the percolation mechanism dominates the sodium diffusion.


Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur Jan 2004

Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur

Gilles Muller

Type II restriction enzymes are homodimeric systems that bind four to eight base pair palindromic recognition sequences of DNA and catalyze metal ion-dependent phosphodiester cleavage. While Mg(II) is required for cleavage in these enzymes, in some systems Ca(II) promotes avid substrate binding and sequence discrimination. These properties make them useful model systems for understanding the roles of alkaline earth metal ions in nucleic acid processing. We have previously shown that two Ca(II) ions stimulate DNA binding by PvuII endonuclease and that the trivalent lanthanide ions Tb(III) and Eu(III) support subnanomolar DNA binding in this system. Here we capitalize on this …


Metallic Single-Walled Silicon Nanotubes, Jaeil Bai, Xiao Cheng Zeng, Hideki Tanaka, J. Y. Zeng Jan 2004

Metallic Single-Walled Silicon Nanotubes, Jaeil Bai, Xiao Cheng Zeng, Hideki Tanaka, J. Y. Zeng

Xiao Cheng Zeng Publications

Atomistic computer-simulation evidences are presented for the
possible existence of one-dimensional silicon nanostructures: the
square, pentagonal, and hexagonal single-walled silicon nanotubes
(SWSNTs). The local geometric structure of the SWSNTs
differs from the local tetrahedral structure of cubic diamond
silicon, although the coordination number of atoms of the SWSNTs
is still fourfold. Ab initio calculations show that the SWSNTs
are locally stable in vacuum and have zero band gap, suggesting
that the SWSNTs are possibly metals rather than wide-gap
semiconductors.


Self Consistent Field, Scf Homo And Lumo For Cuo2 Layer In Cuprates, H. Sahibudeen, Juana Acrivos Jan 2004

Self Consistent Field, Scf Homo And Lumo For Cuo2 Layer In Cuprates, H. Sahibudeen, Juana Acrivos

Faculty Publications, Chemistry

Before photoemission studies [1995] measured the symmetry of layer cuprate conduction states along the (xy),(-x-y) direction of the unit cell, a SCF analysis [1993] gave the symmetry of the HOMO & LUMO showing O:2pxy-O:2pxy charge de-localization for the conducting CuO2 layer in a superconducting cuprate (T'-Nd2CuO4 in the crystal field of point charges of nearest neighbor unit cells). The predictive power of MO calculations are applied now to understand the concept of valence and periodic lattice distortions commonly found in these solids [2003].


Laser Writing Of Semiconductor Nanoparticles And Quantum Dots, Massimo F. Bertino, Raghuveer Reddy Gadipalli, J. Greg Story, C. G. Williams, Guo-Hui Zhang, Chariklia Sotiriou-Leventis, Akira Tokuhiro, Suchi Guha, Nicholas Leventis Jan 2004

Laser Writing Of Semiconductor Nanoparticles And Quantum Dots, Massimo F. Bertino, Raghuveer Reddy Gadipalli, J. Greg Story, C. G. Williams, Guo-Hui Zhang, Chariklia Sotiriou-Leventis, Akira Tokuhiro, Suchi Guha, Nicholas Leventis

Physics Faculty Research & Creative Works

Silica aerogels were patterned with CdS using a photolithographic technique based on local heating with infrared (IR) light. The solvent of silica hydrogels was exchanged with an aqueous solution of the precursors CdNO3 and NH4 OH, all precooled to a temperature of 5°C. Half of the bathing solution was then replaced by a thiourea solution. After thiourea diffused into the hydrogels, the samples were exposed to a focused IR beam from a continuous wave, Nd-YAG laser. The precursors reacted in the spots heated by the IR beam to form CdS nanoparticles. We lithographed features with a diameter of …


Using Microenvironmental Effects To Increase Loading And Stereoselectivity For Polymer Bound Nabh4 Reagents., James R. Blanton Jan 2004

Using Microenvironmental Effects To Increase Loading And Stereoselectivity For Polymer Bound Nabh4 Reagents., James R. Blanton

Journal of the South Carolina Academy of Science

No abstract provided.


On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Year 1, September 2003, Gary A. Bishop, Daniel A. Burgard, Donald H. Stedman Jan 2004

On-Road Remote Sensing Of Automobile Emissions In The Tulsa Area: Year 1, September 2003, Gary A. Bishop, Daniel A. Burgard, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


High Temperature And Fuel Impacts On Hc Emissions (Presentation), Richard Barrett, Donald H. Stedman Jan 2004

High Temperature And Fuel Impacts On Hc Emissions (Presentation), Richard Barrett, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Infrared Thermal Imaging Of Automobiles (Presentation), Angela M. Monateri, Donald H. Stedman, Gary A. Bishop Jan 2004

Infrared Thermal Imaging Of Automobiles (Presentation), Angela M. Monateri, Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.


A History Of On-Road Emissions And Emissions Deterioration (Presentation), Donald H. Stedman, Gary A. Bishop Jan 2004

A History Of On-Road Emissions And Emissions Deterioration (Presentation), Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.


Analysis Of Free Analyte Fractions By Rapid Affinity Chromatography, David S. Hage, William A. Clarke Jan 2004

Analysis Of Free Analyte Fractions By Rapid Affinity Chromatography, David S. Hage, William A. Clarke

Chemistry Department: Faculty Publications

The invention is generally directed toward an analytical method to determine the concentration of the free analyte fraction in a sample. More particularly, the method encompasses applying a sample comprising a free and bound analyte fraction to an affinity column capable of selectively extracting the free fraction in the millisecond time domain. The signal generated by the free fraction is then quantified by standard analytical detection techniques. The concentration of the free fraction may then be determined by comparison of its signal with that of a calibration curve depicting the signal of known concentration of the same analyte.


Accuracy And Interferences For Enzyme-Linked Immunoassay Tests For Atrazine, Craig D. Adams, Hua Jiang, Michael Mcguire, Nicole Graziano, Alan Roberson, Michelle Frey Jan 2004

Accuracy And Interferences For Enzyme-Linked Immunoassay Tests For Atrazine, Craig D. Adams, Hua Jiang, Michael Mcguire, Nicole Graziano, Alan Roberson, Michelle Frey

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Atrazine is one of the most commonly used herbicides in the United States, therefore it is a regulatory concern and is extensively monitored in the environment, especially in drinking water. Because of the higher costs of gas chromatography (GC) methods, utility managers and regulators are considering the increased use of enzyme-linked immunosorbent assay (ELISA) methods for monitoring atrazine. an ELISA test kit was recently approved by the US Environmental Protection Agency. the research in this article points out potential biases and inaccuracies that may occur with such test kits. ELISA test kits for atrazine are typically precise (repeatable) but often …


Synthesis And Characterization Of Polyimide Residuum, Friable Balloons, Microspheres And Foams, Erik Saul Weiser Jan 2004

Synthesis And Characterization Of Polyimide Residuum, Friable Balloons, Microspheres And Foams, Erik Saul Weiser

Dissertations, Theses, and Masters Projects

In order to meet requirements of future NASA systems for advanced polymeric cellular materials, research was undertaken to develop the next generation of polyimide foams which could be utilized as a reusable structural insulation on future Reusable Launch Vehicle (RLV) Programs. This research activity focused on developing polyimide foam and foam structures which were made using monomeric solutions or salt solutions formed from the reaction of a dianhydride and diamine dissolved in a mixture of foaming agents and alkyl alcohols. This process produced a precursor solid residuum which could then be manufactured into foams, friable balloons and microspheres. Polyimide foams …


Atmospheric Variability Of Methyl Chloride During The Last 300 Years From An Antarctic Ice Core And Firn Air, M. Aydin, Eric S. Saltzman, Warren J. De Bruyn, S. A. Montzka, J. H. Butler, M. Battle Jan 2004

Atmospheric Variability Of Methyl Chloride During The Last 300 Years From An Antarctic Ice Core And Firn Air, M. Aydin, Eric S. Saltzman, Warren J. De Bruyn, S. A. Montzka, J. H. Butler, M. Battle

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Measurements of methyl chloride (CH3Cl) in Antarctic polar ice and firn air are used to describe the variability of atmospheric CH3Cl during the past 300 years. Firn air results from South Pole and Siple Dome suggest that the atmospheric abundance of CH3Cl increased by about 10% in the 50 years prior to 1990. Ice core measurements from Siple Dome provide evidence for a cyclic natural variability on the order of 10%, with a period of about 110 years in phase with the 20th century rise inferred from firn air. Thus, the CH3Cl increase measured in firn air may largely be …


The Use Of Pyrosequencing For The Analysis Of Y Chromosome Single Nucleotide Polymorphisms, Jeremy Charles Fletcher Jan 2004

The Use Of Pyrosequencing For The Analysis Of Y Chromosome Single Nucleotide Polymorphisms, Jeremy Charles Fletcher

Electronic Theses and Dissertations

The potential value of the Y chromosome for forensic applications has been recognized for some time with the current work dedicated to Short Tandem Repeat analysis and Single Nucleotide Polymorphism (SNP) discovery. This study examined the ability of two different SNP analysis methods to determine if they could be utilized in forensic applications and ultimately be developed into an established system for Y chromosome SNP analysis. This study examined two principle SNP analysis systems: single base extension and Pyrosequencing. Pyrosequencing was determined to be superior to single base extension, due to the wealth of information provided with sequencing and the …


The Design And Development Of A Comprehensive 49 Locus Y-Str Database For Major U.S. Populations, Paulina Niki Berdos Jan 2004

The Design And Development Of A Comprehensive 49 Locus Y-Str Database For Major U.S. Populations, Paulina Niki Berdos

Electronic Theses and Dissertations

The establishment of a U.S. National Y-STR reference database from a variety of geographically and ethically diverse populations is essential to facilitate the generation of reliable estimates of Y-STR haplotype frequencies. Such multi-locus haplotype frequencies are required to provide a statistical estimate of the significance of a match. Y-STR loci, unlike traditional STR markers, are not independent of one another and are co-inherited as extended haplotypes of linked markers. The estimation of the frequency of occurrence of a particular haplotype therefore necessitates the use of a counting method, which means that the significance of many matches is dependent upon the …


Stability And Recovery Of Rna In Biological Stains, Mindy Eileen Setzer Jan 2004

Stability And Recovery Of Rna In Biological Stains, Mindy Eileen Setzer

Electronic Theses and Dissertations

In theory, RNA expression patterns, including the presence and relative abundance of particular RNA species, provide cell and tissue specific information that could be of use to forensic scientists. An mRNA based approach could allow the facile identification of the tissue components present in a body fluid stain and conceivably could supplant the battery of serological and biochemical tests currently employed in the forensic serology laboratory. Some of the potential advantages include greater test specificity, and the ability to perform simultaneous analysis using a common assay format for the presence of all body fluids of forensic interest. In this report, …


New Organic/Inorganic Hybrid Sol-Gel Nanocomposite Materials For Raman Gain In Fiber Optics, Stephen James Andrasik Jan 2004

New Organic/Inorganic Hybrid Sol-Gel Nanocomposite Materials For Raman Gain In Fiber Optics, Stephen James Andrasik

Electronic Theses and Dissertations

The recent increased availability of additional wavelengths in the telecommunications window of about 1300-1600 nm has generated an interest in new optical materials and devices that can operate outside the normally used regions of 840 nm, 1310 nm, and 1550 nm. Specifically, methods to amplify fiber optical data transmission in the regions where there is limited or no existing methods to achieve amplification is of interest in the chemistry and photonic communities. Raman gain is one method that has been proposed to passively amplify optical data transmission through a distributed process. Amplification is obtained through a nonlinear light scattering process …


Development Of Electrochemical Sensors For Monitoring Glucose, Michael Nesbitt Jan 2004

Development Of Electrochemical Sensors For Monitoring Glucose, Michael Nesbitt

Theses

The thesis focuses on evaluating calcium alginate as an immobilisation matrix for the oxidase enzyme glucose oxidase for the amperometric determination of glucose. The basic principles of enzymology and enzyme immobilisation is discussed followed by a review of a variety of first, second and third generation type enzyme electrodes. Amperometry as governed by the Cottrell equation and mass transfer models relating to amperometric electrodes are also considered.

Bovine serum albumin (BSA / GOx) enzyme electrode system was employed as a model to evaluate a calcium alginate immobilisation technique for glucose oxidase. The principal methods employed for enzyme immobilisation were:

• …


The Synthesis And Characterisation Of Diiron And Triiron Carbonyl Cluster Compounds With Sulphur And Phosphine Ligands, Geraldine Gray Jan 2004

The Synthesis And Characterisation Of Diiron And Triiron Carbonyl Cluster Compounds With Sulphur And Phosphine Ligands, Geraldine Gray

Theses

This work is primarily concerned with the synthesis and characterisation of di and triiron carbonyl cluster derivatives which contain sulphur and phosphine ligands.

The first chapter is a review of the literature of such complexes. Included are diiron carbonyl clusters which contain phosphine ligands, those which contain sulphur, and those that contain phosphine and sulphur ligands. Triiron carbonyl clusters which contain phosphine ligands, sulphur ligands and both are also discussed.

Chapter two describes the synthesis of compounds of the type [{Fe2(SR)2(CO)5)2Ph2P (CH2)nPPh2] (R = …


Block Copolymer Stabilized Self-Assembled Magnetic Nanoparticles, Li Zhang Jan 2004

Block Copolymer Stabilized Self-Assembled Magnetic Nanoparticles, Li Zhang

Electronic Theses and Dissertations

Magnetic materials are currently being developed in the areas of pharmacology and medicinal chemistry for use in applications such as drug delivery and magnetic resonance imaging. Magnetic fluids are being used in audio equipment and hard disk drives. Their suspension in a particular fluid is promoted by the adsorption or reaction of steric or electrostatic stabilizers, which are appropriate for the particular medium. Critical to the success of these magnetic fluids is the development of the steric stabilizers, which must prevent the coagulation of the metal particles. Polymeric materials are one of the most suitable nonmagnetic media to disperse the …


President's Message, David J. Stroup Jan 2004

President's Message, David J. Stroup

Journal of the South Carolina Academy of Science

No abstract provided.


Building New Culture Media For Assisted Reproductive Technology., Mary N. Egbuniwe, H. Lee Higdon Iii, William R. Boone Jan 2004

Building New Culture Media For Assisted Reproductive Technology., Mary N. Egbuniwe, H. Lee Higdon Iii, William R. Boone

Journal of the South Carolina Academy of Science

No abstract provided.


Bioinformatics: An Undergraduate Research/Teaching Tool., Abhishek Agrawal, Valgene L. Dunham Jan 2004

Bioinformatics: An Undergraduate Research/Teaching Tool., Abhishek Agrawal, Valgene L. Dunham

Journal of the South Carolina Academy of Science

No abstract provided.


Characterization Of Microbial Communities In Tce-Contaminated Seep Zone Sediments., Brian A. Nevius, Christopher E. Bagwell, Robin L. Brigmon Jan 2004

Characterization Of Microbial Communities In Tce-Contaminated Seep Zone Sediments., Brian A. Nevius, Christopher E. Bagwell, Robin L. Brigmon

Journal of the South Carolina Academy of Science

No abstract provided.


Table Of Contents Jan 2004

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.


Electron Transfer In Phosphido-Bridged Complexes, Pradeep N. Perera Jan 2004

Electron Transfer In Phosphido-Bridged Complexes, Pradeep N. Perera

Masters Theses

No abstract provided.


Synthesis, Characterization And Study Of Novel Reagents For The Detection Of Saccharides And Amino Acids, Nadia Nadette St. Luce Jan 2004

Synthesis, Characterization And Study Of Novel Reagents For The Detection Of Saccharides And Amino Acids, Nadia Nadette St. Luce

LSU Doctoral Dissertations

The design of synthetic receptors for the recognition and sensing of saccharides and amino acids is currently a major challenge. This is due to inherent structural similarity and a lack of chromophoric or fluorophoric properties of these compounds. The synthesis and study of novel detection agents for bioactive molecules as well as mechanistic studies are presented herein. The elucidation of the mechanism by which tetraarylboronic acid resorcinarene interact with sugar molecules and promote a solution color change is explored. This vast collaborative study, reveals that DMSO solutions of boronic acid functionalized resorcinarene macrocycles afford visual color changes upon heating or …


Attachment Of Oligonucleotide Probes To Polymer Biochips And Its Application For The Detection Of Point Mutations, Yun Wang Jan 2004

Attachment Of Oligonucleotide Probes To Polymer Biochips And Its Application For The Detection Of Point Mutations, Yun Wang

LSU Doctoral Dissertations

This dissertation is on the fabrication of polymer-based microfluidic arrays for the detection of genetic mutations. Poly(methyl methacrylate) was chosen as one of the polymer substrate materials due to its low background noise, low adsorption of biomolecules, and low assembly temperature. The surface modification of polymer substrates for covalent attachment of oligonucleotide probes, the construction of fluidic channels/arrays, and hybridization kinetics will be covered. As an example of the application, point mutation detection using immobilized arrays constructed in microfluidic devices will be demonstrated. The PMMA surface was derivatized with N-lithioethylenediamine solution to introduce amine groups, which were utilized for the …