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2006

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Articles 541 - 570 of 592

Full-Text Articles in Chemistry

Acid-Catalyzed Time-Efficient Synthesis Of Resorcinol-Formaldehyde Aerogels And Crosslinking With Isocyanates, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis Jan 2006

Acid-Catalyzed Time-Efficient Synthesis Of Resorcinol-Formaldehyde Aerogels And Crosslinking With Isocyanates, Sudhir Mulik, Chariklia Sotiriou-Leventis, Nicholas Leventis

Chemistry Faculty Research & Creative Works

Aerogels are open-cell foams derived from supercritical fluid (SCF) drying of wet gels. Their large internal void space is responsible for low thermal conductivity, high surface area and high acoustic impedance. Most aerogels are based on inorganic metal or semimetal oxide frameworks. Pekala and co-workers synthesized resorcinol-formaldehyde (RF) organic aerogels by poly-condensation of resorcinol with formaldehyde in the presence of Na2CO3 as base catalyst, followed by drying with SCF CO2. Low-density RF aerogels prepared by this method exhibit high porosities (>80%), high surface areas (400-900 m2g-1), ultrafine cell-size (<500 > Å) …

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Conformal Internal Coating Of Macroporous Co-Continuous Mcf-Silicas With Isocyanate Derived Polymers, Nicholas Leventis, Chariklia Sotiriou-Leventis, Xiaojiang Wang, Sudhir Mulik Jan 2006

Conformal Internal Coating Of Macroporous Co-Continuous Mcf-Silicas With Isocyanate Derived Polymers, Nicholas Leventis, Chariklia Sotiriou-Leventis, Xiaojiang Wang, Sudhir Mulik

Chemistry Faculty Research & Creative Works

Since their discovery in 1992,1,2 templating sol-gel silica with structuredirecting agents has resulted in new materials with ordered mesoporous (2-50 nm) structure that is investigated for application in areas as diverse as high surface area supports for caralysts or as nanostructured drug storage and release platforms.3 Structure-directing agents are typically surfactants ranging from cationic detergents such as alkyl-trimethylammonium salts with C8-C18 hydrocarbon chains to non-ionic tertiary amines, polyethylene oxide or amphiphilic triblock copolymers such as poly(ethyleneoxide)-blockpoly( propyleneoxide)-block-poly(ethyleneoxide) (e.g., Pluronic P123). Depending on the surfactant and the conditions (e.g., kind and concentration of catalyst) the structure of the mesopores may vary …

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Segmental Dynamics In Poly(Methyl Acrylate) On Silica: Molecular-Mass Effects, Burak Metin, Frank D. Blum Jan 2006

Segmental Dynamics In Poly(Methyl Acrylate) On Silica: Molecular-Mass Effects, Burak Metin, Frank D. Blum

Chemistry Faculty Research & Creative Works

The effect of molecular mass on the segmental dynamics of poly(methyl acrylate) (PMA) adsorbed on silica was studied using deuterium quadrupole-echo nuclear magnetic resonance (NMR) and modulated differential scanning calorimetry. Samples adsorbed on silica (all about 1.5 mg PMA/m2 silica) were shown to have more restricted segmental mobility, and higher Tg's, than the corresponding bulk PMA samples. Around the glass-transition region, adsorbed samples exhibited segmental mobility, which could be classified as heterogeneous due to a superposition of more-mobile and less-mobile components present in the deuterium NMR spectra. This heterogeneity was consistent with a motional gradient with more-mobile segments near the …

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Exploration Of Iron And Cobalt Core-Shell Nanoparticles Via Thermal And Microwave Polyol Synthesis, Hope M. Klukovich Jan 2006

Exploration Of Iron And Cobalt Core-Shell Nanoparticles Via Thermal And Microwave Polyol Synthesis, Hope M. Klukovich

Browse all Theses and Dissertations

Thermal and microwave polyol methods were investigated in the synthesis of various iron and cobalt core-shell nanoparticles. The reaction involved 1 mmol of an Fe+2 or Co+2 salt, bis-acetylacetanato [(Acac)2] iron (II), cobalt (Acac)2 or iron (II) acetate along with 1 mmol of a surfactant capping agent. The salt was reduced with 2 mmol of a 1,2 diol. When 1,2-hexadecanediol solid was used as a reducing agent, it was dissolved along with the metal salt and capping agent in octyl ether. When 1,2-hexanediol liquid was used as the reducing agent, it was also the solvent, and octyl ether …

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Pyrrole Carboxamides As Potential Carbonic Anhydrase Inhibitors, Nishrin Ismailbhai Marketwala Jan 2006

Pyrrole Carboxamides As Potential Carbonic Anhydrase Inhibitors, Nishrin Ismailbhai Marketwala

Browse all Theses and Dissertations

Carbonic anhydrases (CAs) are metalloenzymes that catalyze the reversible interconversion of CO2 and bicarbonate. We recently initiated a screen of a broad range of indoles and pyrroles possessing acyl-, carboxyl-, amido-, sulfonyl-, sulfamyl- and oxime- functionalities as potential inhibitors of á-CA II isozyme. As slight inhibition was observed in the case of 2-carboxamido-1-(phenylsulfonyl)pyrrole, and aware that pyrrole carboxamide derived sulfonamides had been previously demonstrated to possess CA inhibition, we sought to prepare a series of 1-(phenylsulfonyl)pyrrole-2-carboxamides but lacking a sulfonamide moiety to ascertain if the activity in our case might be due to a hitherto unrecognized pyrrole pharmacophore. To this …

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The Modeling Of Solubility, Frank Christopher Campanell Jan 2006

The Modeling Of Solubility, Frank Christopher Campanell

Browse all Theses and Dissertations

In this work the solubilities of gases in liquids and liquids in liquids were modeled using both physical properties and topological descriptors of the solutes. Quantitative structure-activity relationship (QSAR) methods were employed to create single-linear regression (SLR) and multiple-linear regression (MLR) models of the solubilities. Factor analysis was employed to determine the number of significant factors present in the solubilities. The solubilities of monoalcohols in water, halogenated alkanes in water, gases in water, gases in alkanes, and gases in alcohols were examined and modeled.

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Comments On The Mechanism Of Aging Of Antimony Doped Tin Oxide Based Electrochromic Devices, Joo C. Chan, Nicole A. Hannah, Shankar B. Rananavare, Laura Yeager, Liviu Dinescu, Ashok Saraswat, Pradeep Iyer, James P. Coleman Jan 2006

Comments On The Mechanism Of Aging Of Antimony Doped Tin Oxide Based Electrochromic Devices, Joo C. Chan, Nicole A. Hannah, Shankar B. Rananavare, Laura Yeager, Liviu Dinescu, Ashok Saraswat, Pradeep Iyer, James P. Coleman

Chemistry Faculty Publications and Presentations

Electrochromic effects of antimony doped tin oxide (ATO) nanoparticles are investigated to probe device yellowing (degradation). Voltage vs contrast ratio curves exhibit hysteresis, i.e., image-sticking phenomena due to irreversible charge insertion. X-ray, impedance and optical b* studies suggest that the yellowing/charge trapping is nanoparticle size-dependent with 4 nm size particles exhibiting the least yellowing. Yellowing results in increased impedances of electrode–electrolyte interface and electrode corrosion. Plausible sources of discoloration are formation of insulating complex alkali oxide film, carrier inversion (n-to-p type) through electrochemical Li doping, redeposition of the corroded electrode material and perhaps residual concentration of charge-transfer species.

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Quantitative Model For The Prediction Of Hydrodynamic Size Of Nonionic Reverse Micelles, Melissa A. Michaels Jan 2006

Quantitative Model For The Prediction Of Hydrodynamic Size Of Nonionic Reverse Micelles, Melissa A. Michaels

Theses and Dissertations

The sizes of nonionic reverse micelles were investigated as a function of the molecular structure of the surfactant, the type of oil, the total concentration of surfactant [NP], the ratio of NP4 to total surfactant (r), the water to surfactant molar ratio (ω), temperature, salt concentration, and polar phase. The basis of our investigation was nonylphenol polyethoxylates - NP4 and NP7. Micelle sizes were determined using dynamic light scattering (DLS). A central composite experimental design was used to quantitatively model reverse micelle size as a function of ω, [NP], and r. The model has demonstrated the capability of predicting the …

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Analytical Potential Of Polymerized Liposomes Bound To Lanthanide Ions For Qualitative And Quantitative Analysis Of Proteins, Marina Santos Jan 2006

Analytical Potential Of Polymerized Liposomes Bound To Lanthanide Ions For Qualitative And Quantitative Analysis Of Proteins, Marina Santos

Electronic Theses and Dissertations

One of the intriguing features of biological systems is the prevalence of highly selective and often very strong interactions among different cellular components. Such interactions play a variety of organizational, mechanical, and physiological roles at the cellular and organism levels. Antigen-antibody complexes are representative examples of highly selective and potent interactions involving proteins. The marked specificity of protein-antibody complexes have led to a wide range of applications in cellular and molecular biology related research. They have become an integral research tool in the present genomic and proteomic era. Unfortunately, the production of selective tools based on antigen-antibody interactions requires cumbersome …

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Synthetic Studies Directed Toward The Proposed Structure For Heteroscyphic Acid A, Subhabrata Chaudhury, Shukun Li, William A. Donaldson Jan 2006

Synthetic Studies Directed Toward The Proposed Structure For Heteroscyphic Acid A, Subhabrata Chaudhury, Shukun Li, William A. Donaldson

Chemistry Faculty Research and Publications

A route to the carbon skeleton of the proposed structure for heteroscyphic acid A was developed utilizing a Mn(III)/Cu(II) mediated oxidative free-radical cyclization and nucleophilic addition to (3-methylpentadienyl)iron(1+) cation.

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Highly Cooperative Tetrametallic Ruthenium-Μ-Oxo-Μ-Hydroxo Catalyst For The Alcohol Oxidation Reaction, Chae S. Yi, Tonya N. Zeczycki, Ilia A. Guzei Jan 2006

Highly Cooperative Tetrametallic Ruthenium-Μ-Oxo-Μ-Hydroxo Catalyst For The Alcohol Oxidation Reaction, Chae S. Yi, Tonya N. Zeczycki, Ilia A. Guzei

Chemistry Faculty Research and Publications

The tetrametallic ruthenium-oxo-hydroxo-hydride complex {[(PCy3)(CO)RuH]4(μ4-O)(μ3-OH)(μ2-OH)} (1) was synthesized in two steps from the monomeric complex (PCy3)(CO)RuHCl (2). The tetrameric complex 1 was found to be a highly effective catalyst for the transfer dehydrogenation of alcohols. Complex 1 showed a different catalytic activity pattern toward primary and secondary benzyl alcohols, as indicated by the Hammett correlation for the oxidation reaction of p-X-C6H4CH2OH (ρ = −0.45) and p-X-C6H4CH(OH)CH3 (ρ = +0.22) (X = …

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A Practical Synthesis Of Bridged Diarylacetylenes, Ruchi Shukla, Daniel M. Brody, Sergey V. Lindeman, Rajendra Rathore Jan 2006

A Practical Synthesis Of Bridged Diarylacetylenes, Ruchi Shukla, Daniel M. Brody, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

An efficient and practical synthesis of bridged diarylacetylenes in multigram quantities has been successfully carried out using high-yielding (classical) synthetic methods and readily available starting materials. The structural analysis of the representative bridged diarylacetylenes by X-ray crystallography strongly suggests that conformations, bending of the linear triple bond, and the angle between the mean planes of aromatic rings in various bridged diarylacetylenes are governed by the p−π conjugation among the aromatic rings and the ethereal groups. Furthermore, the synthetic scheme also allows the preparation of (appropriately) bromo-substituted bridged diarylacetylenes which hold potential for their future usage for the preparation of polymeric …

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Thermal And Flame Properties Of Polyethylene And Polypropylene Nanocomposites Based On An Oligomerically–Modified Clay, Jinguo Zhang, David D. Jiang, Charles A. Wilkie Jan 2006

Thermal And Flame Properties Of Polyethylene And Polypropylene Nanocomposites Based On An Oligomerically–Modified Clay, Jinguo Zhang, David D. Jiang, Charles A. Wilkie

Chemistry Faculty Research and Publications

An oligomerically-modified clay was made using a surfactant which is the ammonium salt of an oligomer. The newly modified clay contains 37.5% inorganic clay and 62.5% oligomer. Polyethylene and polypropylene nanocomposites were made by melt blending the polymer with the oligomerically-modified clay in a Brabender mixer at various clay loadings. The structure of the nanocomposites was characterized by X-ray diffraction and transmission electron microscopy. Mechanical testing showed that the polyethylene nanocomposites had an enhanced Young's modulus and slightly decreased elongation, while the changes for polypropylene nanocomposites are small compared with the virgin polymers. The thermal stability and flame properties were …

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Solubilisation, Purification And Processing Of Single Walled Carbon Nanotubes Using Organic Molecules, Theresa Hedderman Jan 2006

Solubilisation, Purification And Processing Of Single Walled Carbon Nanotubes Using Organic Molecules, Theresa Hedderman

Doctoral

The aims of this research are seven fold; • To enhance the solubility of SWNTs in organic solvents. • To purify an untreated sample of SWNTs that contains many side products. • To gain a greater understanding of the interaction between the polycyclic aromatic hydrocarbons and SWNTs. • To debundle and disperse SWNTs. • To select SWNTs of a specific structure based on the structures of the polycyclic aromatic hydrocarbons used. • To observe and compare the interaction of polycyclic aromatic hydrocarbons with SWNTs produced by different methods. • To elucidate factors which contribute to different degrees of interaction between …

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Dna Damage Responses In Progeroid Syndromes Arise From Defective Maturation Of Prelamin A, Michael Sinensky, Y. Liu, A. Rusinol, Y. Wang, Y. Zou Jan 2006

Dna Damage Responses In Progeroid Syndromes Arise From Defective Maturation Of Prelamin A, Michael Sinensky, Y. Liu, A. Rusinol, Y. Wang, Y. Zou

Faculty Publications, Biological Sciences

The genetic diseases Hutchinson-Gilford progeria syndrome (HGPS) and restrictive dermopathy (RD) arise from accumulation of farnesylated prelamin A because of defects in the lamin A maturation pathway. Both of these diseases exhibit symptoms that can be viewed as accelerated aging. The mechanism by which accumulation of farnesylated prelamin A leads to these accelerated aging phenotypes is not understood. Here we present evidence that in HGPS and RD fibroblasts, DNA damage checkpoints are persistently activated because of the compromise in genomic integrity. Inactivation of checkpoint kinases Ataxia-telangiectasia-mutated (ATM) and ATR (ATM- and Rad3-related) in these patient cells can partially overcome their …

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Farnesylated Lamins, Progeroid Syndromes And Farnesyl Transferase Inhibitors, Michael Sinensky, A. E. Rusinol Jan 2006

Farnesylated Lamins, Progeroid Syndromes And Farnesyl Transferase Inhibitors, Michael Sinensky, A. E. Rusinol

Faculty Publications, Biological Sciences

Three mammalian nuclear lamin proteins, lamin B1, lamin B2 and the lamin A precursor, prelamin A, undergo canonical farnesylation and processing at CAAX motifs. In the case of prelamin A, there is an additional farnesylation-dependent endoproteolysis, which is defective in two congenital diseases: Hutchinson-Gilford progeria (HGPS) and restrictive dermopathy (RD). These two diseases arise respectively from defects in the prelamin A substrate and the enzyme (ZmpSte24) that processes it. Recent work has shed light on the roles of the lamin proteins and the enzymes involved in their farnesylation-dependent maturation. Other experimental work, including mouse model studies, have examined the possibility …

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Synthesis Of Glycosylamides And Carbohydrate Fused Heterocycles, Michael De Castro Jan 2006

Synthesis Of Glycosylamides And Carbohydrate Fused Heterocycles, Michael De Castro

Seton Hall University Dissertations and Theses (ETDs)

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Studies On 2-Ethyl-3-Carbmethoxy-4-Aryl-5-Oxo-1,4,5,6,7,8-Hexahydroquinoline Derivatives And Calcium Modulatory Activities, Ci̇hat Şafak, Elvan Doğan, Kevser Erol Jan 2006

Studies On 2-Ethyl-3-Carbmethoxy-4-Aryl-5-Oxo-1,4,5,6,7,8-Hexahydroquinoline Derivatives And Calcium Modulatory Activities, Ci̇hat Şafak, Elvan Doğan, Kevser Erol

Turkish Journal of Chemistry

Twelve new compounds having a 2-ethyl-3-carbmethoxy-4-aryl-5-oxo-1,4,5,6,7,8-hexahydroquinoline structure were synthesized, characterized and screened for their calcium modulatory activities. The calcium antagonistic activities of the compounds were investigated by tests performed on isolated rat ileum and lamb carotid artery. Compounds 1, 4, 8 and 9 showed considerable activity.

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Synthesis And Characterization Of Metal Complexes Of Cu(Ii), Ni(Ii), Zn(Ii), Co(Ii), Mn(Ii) And Cd(Ii) With Tetradentate Schiff Bases, Jianning Liu, Bo-Wan Wu, Bing Zhang, Yongchun Liu Jan 2006

Synthesis And Characterization Of Metal Complexes Of Cu(Ii), Ni(Ii), Zn(Ii), Co(Ii), Mn(Ii) And Cd(Ii) With Tetradentate Schiff Bases, Jianning Liu, Bo-Wan Wu, Bing Zhang, Yongchun Liu

Turkish Journal of Chemistry

4-(Benzeneazo)salicylaldehyde was synthesized with aniline, sodium nitrite and salicylaldehyde. Two tetradentate ligands, N,N'-bis[4-(benzeneazo) salicylaldehyde]-o-phenylenediamine (H_2L) and N,N'-bis[4-(benzeneazo) salicylaldehyde]ethylenediamine (H_2L') were formed by the 2:1 molar condensation of 4-(benzeneazo) salicylaldehyde with o-phenylenediamine or ethylenediamine. Their Cu(II), Ni(II), Zn(II), Co(II), Mn(II) and Cd(II) complexes were synthesized and characterized by elemental analysis, molar conductivity measurements, and infrared and electronic spectral data. Two ligands and their Ni(II) and Zn(II) complexes were further identified using ^1H NMR spectra. The results suggest that the metal is bonded to the ligand through the phenolic oxygen and the imino nitrogen.

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The Impact Of Polyacrylamide Molecular Weight On Its Adsorption Behavior At The Gold/Acidic Solution Interface, Dragica B. Chamovska, Toma P. Grchev, Maja V. Cvetkovska Jan 2006

The Impact Of Polyacrylamide Molecular Weight On Its Adsorption Behavior At The Gold/Acidic Solution Interface, Dragica B. Chamovska, Toma P. Grchev, Maja V. Cvetkovska

Turkish Journal of Chemistry

Adsorption isotherms for polyacrylamide (PAA) on polycrystalline gold, from sulfuric acid (potential range 0-2.0 V/she; 293 K), were obtained by means of cyclic voltammetry with simultaneous monitoring of the double-layer capacity. The Frumkin isotherm indicates that relatively strong attractive forces are present (a = 0.8-1.0), and the Gibbs energies range between 43 and 56 kJ mol^{-1}. The coverage (\theta) of the metal surface with polymer molecules depends on the molar concentration of PAA, as well as on its molecular weight, and the size of the statistical polymer coil in the solution (R_G = 7.49 \times 10^{-3} \times M_n^{0.64}/nm). The adsorption …

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Solution And Solid State Interactions Between Ionic Π-Systems, Jing Chen Jan 2006

Solution And Solid State Interactions Between Ionic Π-Systems, Jing Chen

University of Kentucky Doctoral Dissertations

Although attractive interactions between π systems (π-π interaction) have been known for many years, understanding of its origin is still incomplete. Quantitative measuring of π-stacking is challenging due to the weak nature of the π-π interaction. This dissertation aims at elucidating a quantitative conformational analysis by NMR ring current anisotropy of an organic compound capable of intramolecular π-stacking in solution and studying charge effects on the stacking of π-systems. This dissertation offers four contributions to the area. (1) A general approach to four-state, conformational analysis based on the magnetic anisotropy of molecules undergoing fast dynamic exchange is described. (2) Study …

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In-Use Emission Measurements Of Snowmobiles And Snowcoaches In Yellowstone National Park, Gary A. Bishop, Daniel A. Burgard, Thomas R. Dalton, Donald H. Stedman Jan 2006

In-Use Emission Measurements Of Snowmobiles And Snowcoaches In Yellowstone National Park, Gary A. Bishop, Daniel A. Burgard, Thomas R. Dalton, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

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Multianalyte Detection Of Breast Cancer By Fabrication Of Hybridmicroarrays On Polymer-Based Microanalytical Devices, Suying Wei Jan 2006

Multianalyte Detection Of Breast Cancer By Fabrication Of Hybridmicroarrays On Polymer-Based Microanalytical Devices, Suying Wei

LSU Doctoral Dissertations

Breast cancer is one of the most common and fatal cancer diseases that affect women worldwide. As is true with most other cancer diseases, early detection of breast cancer is very crucial for proper medical treatment because treatment of advanced breast cancer will be much more difficult and inconsistent. Screening and testing of breast cancer biomarkers, either genetic or proteomic, are among techniques used for diagnosis of breast cancers. Nevertheless, none of the biomarkers is by itself sensitive and selective enough for diagnosis of breast cancer, and thus, multi-analyte assays towards detection of multiple breast cancer biomarkers from different classes …

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Fabrication, Characterization And Properties Of Hiercchically Ordered Nanocomposites, Avinash Dundigalla Jan 2006

Fabrication, Characterization And Properties Of Hiercchically Ordered Nanocomposites, Avinash Dundigalla

LSU Doctoral Dissertations

The objectives of this research are to study the structure, morphology and properties of poly(ethylene-oxide) (PEO)-clay nanocomposites using various imaging techniques. Optical Microscopy, Scanning Electron Microscopy, Environmental Scanning Electron Microscopy and Atomic Force Microscopy are used to image structures on all length scales. Complementary scattering experiments are discussed along with preliminary differential scanning calorimetry and Fourier Transform Infrared spectroscopy results. In particular we investigated the multilayered structures of PEO-Laponite and PEO-Montmorillonite multilayered films made from solution. The shear orientation of a polymer-clay network in solution combined with simultaneous solvent evaporation leads to supramolecular multilayer formation in the film. The resulting …

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Crystal Growth And The Search For Highly Correlated Ternary Intermetallic Antimonides And Stannides, Evan Lyle Thomas Jan 2006

Crystal Growth And The Search For Highly Correlated Ternary Intermetallic Antimonides And Stannides, Evan Lyle Thomas

LSU Doctoral Dissertations

This dissertation describes the crystal growth, chemical structures, and efforts made towards the understanding of the physical properties of novel ternary rare-earth intermetallics, which may display signature behavior such as superconductivity, heavy fermion behavior, intermediate valence, and/or large magnetoresistance. To address the problem of correlating these characteristics with structural features, several ternary antimony- and tin-containing phases, Ln-T-X (Ln = lanthanide; T = Co, Ni, Pd; X = Sn, Sb), have been synthesized in single crystalline form by metallic flux-growth methods and characterized by X-ray diffraction. The antimonide compounds LnNi1-xSb2 (Ln = Y, Gd-Tb, Er, Yb), alpha, beta-LnNiSb3 (Ln = La, …

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Application Of Polymeric Microfluidic Devices For Separation Of Single-Stranded Dna, Shawn Llopis Jan 2006

Application Of Polymeric Microfluidic Devices For Separation Of Single-Stranded Dna, Shawn Llopis

LSU Doctoral Dissertations

Microsystems targeted for DNA sequencing, especially those focused on electrophoretic separations, are rapidly proving their viability to genomic research, mimicking the progress made when capillary electrophoresis developed from miniaturizing slab gel electrophoresis techniques. Being the more recent electrophoretic separation platform, the commercial availability of microchip electrophoresis devices remains relatively limited. To this extent, high-aspect ratio microstructures formed in thermo plastics have been developed using rapid fabrication methods from molding tools designed for mass replication of high-aspect ratio microfeatures. In this work, the choice and compatibility of poly(methylmethacrylate) (PMMA) – the primary substrate for DNA separations in this work – was …

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Porous Inorganic-Organic Materials Based On Beta-Diketone Ligands, Yixun Zhang Jan 2006

Porous Inorganic-Organic Materials Based On Beta-Diketone Ligands, Yixun Zhang

LSU Doctoral Dissertations

Synthesis and characterization of porous inorganic-organic materials have been studied mainly on two linear β-diketone multifunctional ligands: pyridine based pyacH and isocyanide based HacphNC. As a known ligand, the preparation of pyacH has been improved with higher yield. When pyacH reacts with Fe and Al metal salts, trigonal metal β-diketonate building blocks M(pyac)3 are produced. When pyacH reacts with zinc acetate, both trans and cis Zn(pyac)2 are produced, both isomers were isolated and characterized by single-crystal X-ray crystallography. Solutions of the trigonal building block Fe(pyac)3 generate various crystal structures on reaction with AgNO3 in CH3CN. When the concentration of AgNO3 …

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Structural Characterization Of Poly(Heterocycles) Formed Using Oxidative Methods, Rebecca Marie Brauch Jan 2006

Structural Characterization Of Poly(Heterocycles) Formed Using Oxidative Methods, Rebecca Marie Brauch

LSU Doctoral Dissertations

This research focused on elucidation of structural information for conducting polymer systems using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The structure of conducting polymer systems has been found to directly influence their physical properties. Poly(pyrrole) and poly(thiophene) are two of the most widely studied conducting polymers due to their high electrical conductivity, stability in the doped state, low toxicity, and current/potential applications. The purpose of this research was to apply MALDI-TOF MS to heterocyclic conducting polymers, specifically those of pyrrole and thiophene, to investigate structural properties of these polymers, with the specific aim of determining end group and …

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Two-Dimensional And High-Throughput Electrophoretic Separation Of Proteins Using Polymeric Microchips, Hamed Shadpour Jan 2006

Two-Dimensional And High-Throughput Electrophoretic Separation Of Proteins Using Polymeric Microchips, Hamed Shadpour

LSU Doctoral Dissertations

A major task in proteomics is to identify proteins from a biological sample using two-dimensional (2-D) separation prior to mass spectrometry of peptides generated via proteolytic digestion of the proteins. For 2-D separations, microfluidic devices are superior to bench top and capillary-based systems since they potentially provide higher separation efficiencies due to the minimal dead volumes produced during peak transfer between the two separation dimensions. In addition, fast separations can be envisioned because the column lengths are typically shorter in microfluidic platforms without scarifying peak capacity. High-throughput capabilities are extremely desirable for many types of bio-analytical analyses, such as understanding …

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Influence Of Surface Chemistry On The Aggregation Of Beta Amyloid Peptide, Mariah Joan Wooldridge Mcmasters Jan 2006

Influence Of Surface Chemistry On The Aggregation Of Beta Amyloid Peptide, Mariah Joan Wooldridge Mcmasters

LSU Doctoral Dissertations

Alzheimer's disease is a progressive neurological ailment affecting 4.5 million aging Americans. The disease is characterized by the presence in the brain of self-assembled fibrils consisting of beta amyloid protein (Aβ). Soluble Aβ protein is present in normal human cerebrospinal fluid, but it is unclear what makes the protein aggregate into insoluble plaques. There is evidence that the Aβ fibril assembly is affected by interactions with biological surfaces, such as neuronal membranes. Here, surfaces consisting of self-assembled alkanethiol monolayers with different end groups were used to test the effect of surface chemistry on the structure and morphology of aggregates formed …

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