Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons™

Open Access. Powered by Scholars. Published by Universities.®

2009

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 121 - 150 of 823

Full-Text Articles in Chemistry

A Direct Borohydride Fuel Cell With Fecopc2-Catalysed Cathode, Jin-Fu Ma, Yan Liu, Jun-Hua Lai, Yong-Ning Liu Aug 2009

A Direct Borohydride Fuel Cell With Fecopc2-Catalysed Cathode, Jin-Fu Ma, Yan Liu, Jun-Hua Lai, Yong-Ning Liu

Journal of Electrochemistry

In this paper,a membraneless direct borohydride fuel cell was investigated. Cyclic voltammograms of FeCoPc2-modified glassy carbon electrode in the alkaline solution show that FeCoPc2 was active for oxygen reduction reaction. In addition, the steady-state polarization curve tests indicate that FeCoPc2 had better activity than FePc,CoPc or FePc+CoPc, which is due to its conjugated effect and synergistic effect of Fe and Co. Finally, a maximum power density of 110 mW/cm2 was attained, and the 25-day life test shows that the direct borohydride fuel cell had a good stability.

Go to article

Simultaneous Determination Of Uric Acid(Ua) And Ascorbic Acid(Aa) At Pca/Gc Electrode, Ren Wang, Ying Zhang, Jie Ding Aug 2009

Simultaneous Determination Of Uric Acid(Ua) And Ascorbic Acid(Aa) At Pca/Gc Electrode, Ren Wang, Ying Zhang, Jie Ding

Journal of Electrochemistry

Poly(cinnamic acid)-modified electrode (PCA /GC) was prepared by potentiostatic technique and was used for determination of uric acid (UA),ascorbic acid (AA),and their mixture by cyclic voltammetry. This modified electrode exhibited a potent and persistent electron-mediating behavior followed by well-separated oxidation peaks toward UA and AA at a scan rate of 50 mV·s-1 with a potential difference of 280 mV,which is large enough to determine UA and AA individually and simultaneously. The catalytic peak current obtained was linearly dependent on the UA and AA concentrations in the range of 2.0×10-6~1.0×10-4 mol·L-1,2.0×10-5~6.0×10-4 mol·L …

Go to article

Electrochemically Induced Free Radical Polymerization Of Methacrylic Acid And Fabrication Of Amperometric Glucose Biosensor, Sheng Wang, Ying Lei, Kang Shi Aug 2009

Electrochemically Induced Free Radical Polymerization Of Methacrylic Acid And Fabrication Of Amperometric Glucose Biosensor, Sheng Wang, Ying Lei, Kang Shi

Journal of Electrochemistry

Electrochemically induced free radical polymerization of methacrylic acid was preliminarily investigated. Based on the electrochemical reduction of persulfate anion in phosphate buffer (pH 7.0) solution,the free radical polymerization of methacrylic acid was initiated to generate an ultrathin and biocompatible hydrogel layer on the gold electrode. At the meantime,glucose oxidase could be immobilized within the hydrogel film in the polymerization process. The resulting biosensor displayed an attractive performance.

Go to article

The Electrochemical Behavior Of Daunorubicin Hydrochloride On Galactic Disk Electrode And Its Reaction With Bsa, Hong-Fen Cheng, Yong Zhang, Jie Liu, Yan-Mei Liu Aug 2009

The Electrochemical Behavior Of Daunorubicin Hydrochloride On Galactic Disk Electrode And Its Reaction With Bsa, Hong-Fen Cheng, Yong Zhang, Jie Liu, Yan-Mei Liu

Journal of Electrochemistry

This article used the linear sweep voltammetry and the circulation voltammetry to study the electrochemical behavior of daunorubicin hydrochloride on galactic disk electrode and its electrode reaction with BSA.Also it studied the interaction of daunorubicin hydrochloride with BSA.The results showed that daunorubicin hydrochloride has a sensitive reduction peak at -0.64 V(vs. SCE) in pH 6.50 Britton-Robinson buffer.The valus of reductions peak current reduced by the addition of BSA to the above mentioned solution.A new electrochemical determination method of bovine serum albumin was developed based on the interaction of daunorubicin hydrochloride with BSA.Furthermore,under the optimized condition,the decrease of the reduction peak …

Go to article

Redox State Of Polyaniline Nanodot And Its Coulomb Staircase Effect, Jian-Zhang Zhou, Shao-Huang Weng, Zhong-Hua Lin Aug 2009

Redox State Of Polyaniline Nanodot And Its Coulomb Staircase Effect, Jian-Zhang Zhou, Shao-Huang Weng, Zhong-Hua Lin

Journal of Electrochemistry

Polyaniline nanodot array had been fabricated in AAO template with potentiostatic method and the I~V characteristics of nanodots with different redox states were measured by conducting atomic force microscope (C-AFM) in atmosphere at room temperature. We found that only nanodots in partial oxidation state exhibit coulomb staircase in the I~V curves,while those in the full oxidation state and reduced state do not. The above phenomena were discussed preliminarily.

Go to article

Electrochemical Reduction Of Nitrobenzene In Different Ionic Liquids, Jun-Li Fan, Wei-Lin Ye, Rong Wang, Li-Qun Xu, Xia-Qin Wu Aug 2009

Electrochemical Reduction Of Nitrobenzene In Different Ionic Liquids, Jun-Li Fan, Wei-Lin Ye, Rong Wang, Li-Qun Xu, Xia-Qin Wu

Journal of Electrochemistry

Electrochemical reduction of nitrobenzene at glassy carbon electrode in different ionic liquids,such as N-methylimidazolium-p-toluene sulfonic acid ([Mim][PhSO3]) and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]) have been investigated by cyclic voltammetry. Experimental results showed that only a cathodic current peak was observed in [Mim][PhSO3],which is a diffusional controlled irreversible reaction. And two pairs of current peaks were obtained in [Bmim][PF6] in the same potential range,indicating showed that the reduction products of nitrobenzene were different in different ionic liquids.

Go to article

Electrochemical Studies On The Ionic Charge Transfer Properties Of The Oxygen Vacancy Defects In The Oxide Films Formed On Titanium, De-Sheng Kong, Hai-Yan Liu, Wen-Juan Fan, Wen-Hua Lv, Zhang-Yu Yu, Yuan-Yuan Feng Aug 2009

Electrochemical Studies On The Ionic Charge Transfer Properties Of The Oxygen Vacancy Defects In The Oxide Films Formed On Titanium, De-Sheng Kong, Hai-Yan Liu, Wen-Juan Fan, Wen-Hua Lv, Zhang-Yu Yu, Yuan-Yuan Feng

Journal of Electrochemistry

The ionic charge transfer properties of the oxygen vacancy point defects in TiO2 films formed on titanium were studied in 1.0 mol·L-1 HClO4 solution with cyclic voltammetry,potentiostatic polarization,galvanostatic reduction and capacitance measurements. The measured capacitance data were analyzed based on the Mott-Schottky equation and Einstein equation. Based on the different response times to the changes of the applied electric field between the ionic and the electronic charge transfers,the diffusion coefficient of the point defects in the anodic oxide film on titanium was estimated. It was shown that the passive potential region for titanium in 1.0 mol·L-1 …

Go to article

Composite Micro-Porous Polymer Electrolyte Of Pvdf-Hfp Modified By Mcm-48, Wei-Feng Wu, Chang-Chun Yang, Su-Jiao He, Bing-Bing Zhang, Song Xu Aug 2009

Composite Micro-Porous Polymer Electrolyte Of Pvdf-Hfp Modified By Mcm-48, Wei-Feng Wu, Chang-Chun Yang, Su-Jiao He, Bing-Bing Zhang, Song Xu

Journal of Electrochemistry

The composite micro-porous polymer electrolyte (CMPE) of PVDF-HFP modified by meso-porous molecular sieves of MCM-48 was prepared by phase-inversion process. The ionic conductivity and Li+ transference number of the polymer electrolyte were raised,respectively,by 97%(from 0.89 mS/cm to 1.75 mS/cm) and 39%(from 0.57 to 0.79),when 4%(by mass) MCM-48 was added in. Meanwhile,the crystallinity and electrochemical stability of the polymer electrolyte had not been changed by the addition of MCM-48. The charge-discharge efficiency of the button cell assembled with the composite membrane (Li/4%MCM-48-CMPE/LiFePO4) was 91% in the first cycle,and no loss of capacity was found even after 30 cycles. …

Go to article

Structural Basis For High-Rate Capability Of Cathode Material Li0.1Fe0.9Mg0.1Po4, Lin Hu, Zheng Li, Zhao-Qiang Zeng Aug 2009

Structural Basis For High-Rate Capability Of Cathode Material Li0.1Fe0.9Mg0.1Po4, Lin Hu, Zheng Li, Zhao-Qiang Zeng

Journal of Electrochemistry

Cathode materials LiFePO4 and LiFe0.9Mg0.1PO4 for lithium ion batteries were synthesized by a solid state reaction. Chemical oxidation to obtain Li0.4Fe0.9Mg0.1PO4 and LiFe0.9Mg0.1PO4was carried out by reacting LiFe0.9Mg0.1PO4 with K2S2O8 solution of different concentration. Li0.1Fe0.9Mg0.1PO4 was confirmed to be a single phase compound with no impure phases,investigated by X-ray diffraction (XRD),selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) techniques. Calculated lattice …

Go to article

Crystallization And Electrochemical Corrosion Behaviors Of Amorphous And Nanocrystalline Fe-Based Alloys, Xiang Li, Biao Yan, Peng Dong Aug 2009

Crystallization And Electrochemical Corrosion Behaviors Of Amorphous And Nanocrystalline Fe-Based Alloys, Xiang Li, Biao Yan, Peng Dong

Journal of Electrochemistry

In this study,amorphous Fe78Si13B9 and Fe73.5Si13.5B9Nb3Cu1 ribbons were prepared by the chill block melt-spinning process and nanocrystalline Fe73.5Si13.5B9Nb3Cu1 ribbons were obtained by annealing. The amorphous ribbons and their crystallization processes were identified by differential scanning calorimeter (DSC) and X-ray diffraction (XRD). A comparative study of the electrochemical corrosion behaviors of  Fe78Si13B9 and Fe73.5Si13.5B9Nb3Cu1 amorphous and nanocrystallized alloys was performed by linear polarization method …

Go to article

Synthesis And Characterization Of Sulfur-Carbonnanotubes As Cathode Of Lithium/Sulfur Rechargeable Battery, Rui Du, Zhong-Zhi Yuan Aug 2009

Synthesis And Characterization Of Sulfur-Carbonnanotubes As Cathode Of Lithium/Sulfur Rechargeable Battery, Rui Du, Zhong-Zhi Yuan

Journal of Electrochemistry

A carbon-containing composite was synthesized by heating element sulfur and carbon nanotubes. The sulfur-carbonnanotube composites were characterized by X-ray diffraction, SEM, Brunauer-Emmett-Teller. The electrochemical property was characterized by cyclic voltammetry,constant current charge and discharge. It was revealed that the sulfur-carbonnanotube cathode 2016-type coin cells exhibited a good electrochemical property with the initial dicharge specific capacity up to 680 mAh/g and a stable capacity approximately 500 mAh/g after 30 cycle numbers.

Go to article

Capacitor Property Of Pani/Mwcnt Electrode In Li2So4 Solution, Wen-Bo Cong, Xiao-Shu He Aug 2009

Capacitor Property Of Pani/Mwcnt Electrode In Li2So4 Solution, Wen-Bo Cong, Xiao-Shu He

Journal of Electrochemistry

Polyaniline/multi-walled carbon nanotubes (PANI/MWCNT) composites synthesized by chemical oxidation method were characterized by scanning electron microscopy (SEM),X-ray diffraction (XRD) and IR techniques. In 1mol/L Li2SO4 neutral solution,the electrochemical performance of the composites electrode was investigated by cyclic voltammetry,galvanostatic charge-discharge tests and ac impedance spectroscopy. The results showed that the composites electrode performed well in 1mol/L Li2SO4 solution,the specific capacitance reached 412F/g at 5 mA/cm2. The composites electrode possessed better capability of high current than that of PANI electrode,the specific capacitance kept at 318 F/g at 50mA/cm2 and was 77.2% of that …

Go to article

Tungstate/Pertungstate System Cathodic Indirect Oxidation To Synthesis Hydrophobic Monascus Yellow Colorant, Wen-Jian Chen, Xue-Hong Huang, Zhen Chen, Sheng-Bo Ke, You-Zhen Lin Aug 2009

Tungstate/Pertungstate System Cathodic Indirect Oxidation To Synthesis Hydrophobic Monascus Yellow Colorant, Wen-Jian Chen, Xue-Hong Huang, Zhen Chen, Sheng-Bo Ke, You-Zhen Lin

Journal of Electrochemistry

Using SBS-g-(AA/StSO3Na)/SBS-g-DMAEMA Bipolar Membrane as a separator between the cathode and anode chambers in the electrolysis cell,the optimum conditions of deoxidization of oxygen in cathode were obtained through orthogonal experiment. Then using tungstate/pertungstate as media to indirect electrooxidate hydrophobic monascus red colorant to prepare hydrophobic monascus yellow colorant in cathode. The experiment results show the average current efficiency of cathode was up to 72.39% under the following conditions:that graphite as electrode,10% sulfuric acid as anode electrolyte,0.5 g·L-1 hydrophobic monascus red colorant solution as cathode electrolyte,tungstate concentration:15 mmol/L,pH=3,flow rate of oxygen:65 cm3/min,electrolyze 2 h under the …

Go to article

Electrocatalytic Oxidation Of Glucose On Cnt/Nanocrystlline Tio2-Pt Complex Film Electrode In Ionic Liquids, Dao-Bao Chu, Long-Wu Zha, Shu-Xi Wang, Jian Wang, Ying Xiao, Yuan-Yuan Hou, Jian-Guo He, Xue-Jiao Zhang Aug 2009

Electrocatalytic Oxidation Of Glucose On Cnt/Nanocrystlline Tio2-Pt Complex Film Electrode In Ionic Liquids, Dao-Bao Chu, Long-Wu Zha, Shu-Xi Wang, Jian Wang, Ying Xiao, Yuan-Yuan Hou, Jian-Guo He, Xue-Jiao Zhang

Journal of Electrochemistry

Using ionic liquid [EMI]BF4 as the electrolyte,the electrocatalytic oxidation of glucose on carbon nanotubes/nanocrystlline TiO2 film loaded on Pt (CNT/nanoTiO2-Pt) complex film electrode was investigated by cyclic voltammetry. The results found that the CNT/nanoTiO2-Pt complex electrode had high catalytic activity to the electrochemical oxidation of glucose in ionic liquids and the oxidation potential was -0.46 V. The best effect of glucose oxidation was obtained with the volume ratio of ionic liquid to water being 3:1. The process of electrodic reaction process was concentration polarization controlled.

Go to article

Electrochemical Properties Of Ru-P/Mwcnts-Dhp/Gc Electrode, Miao-Jing Chen, Bao-Yi Lu, Wen-Jie Mei, Hong Li Aug 2009

Electrochemical Properties Of Ru-P/Mwcnts-Dhp/Gc Electrode, Miao-Jing Chen, Bao-Yi Lu, Wen-Jie Mei, Hong Li

Journal of Electrochemistry

Electrochemical properties of a novel monoruthenated porphyrin [Ru(phen)2(MPyTMPP)Cl]+ (where phen =1,10-phenanthroline,MPyTMPP =5-(3-pyridyl)-10,15,20-tris-(4-methylphenyl) porphyrin) on a multi-walled carbon nanotubes (MWCNTs) modified glassy carbon (GC) electrode with the participation of dihexadecyl phosphate (DHP) have been investigated by using cyclic voltammetry,differential pulse voltammetry,UV-Visible spectroscopy and fluorescence spectroscopy. It is found that [Ru(phen)2(MPyTMPP)Cl]+ has the ability to adsorb strongly onto the MWCNTs-DHP modified GC electrode and exhibits a pair of redox waves controlled by surface electrochemical process. DHP dispersed on the MWCNTs/GC electrode can facilitate the ruthenium complex to adsorb onto the MWCNTs-DHP surface. A new complex is generated by the …

Go to article

Ellipsometric Study On Colored Electroplating Of Cuprous Oxide On Ni Substrate, Xue-Song Feng, Jing-Lei Lei, Ai-Xiang Chen, Wan-Shan Yin, Ling-Jie Li, Sha Zheng, Hui Zhao, Shao-Yan Pan Aug 2009

Ellipsometric Study On Colored Electroplating Of Cuprous Oxide On Ni Substrate, Xue-Song Feng, Jing-Lei Lei, Ai-Xiang Chen, Wan-Shan Yin, Ling-Jie Li, Sha Zheng, Hui Zhao, Shao-Yan Pan

Journal of Electrochemistry

The colored Cu2O coating was electroplated on Ni substrate to meet the decorative requirements. Results of X-ray photoelectron spectroscopy (XPS) indicate the coating consisting of Cu2O. Images of scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) show that the Cu2O coating is smooth and uniform,and covers the Ni substrate wholly. Ellipsomtric measurements for Cu2O coatings with various electroplating time were carried out. Using a 4-layer model of "Air-Cu2O layer-interphase-Ni" ,the interphase was modeled with the graded effective medium approximation (EMA),the ellipsomtric data were deconvoluted and the Cu2O …

Go to article

Monte Carlo Simulation Of Kinetics Of Phenol Degradation On Titanium Based Anode, Xing-Fang Zhang, Zhen-Hai Liang, Wen-Ping Shi, Cai-Mei Fan Aug 2009

Monte Carlo Simulation Of Kinetics Of Phenol Degradation On Titanium Based Anode, Xing-Fang Zhang, Zhen-Hai Liang, Wen-Ping Shi, Cai-Mei Fan

Journal of Electrochemistry

According to Monte Carlo mechanism and random process theory,the mechanism of phenol degradation on titanium electrode was simulated. The effects of degradation time,initial concentration of phenol,electrode performance and intermediates on the process of degradation were determined. The results indicated that the phenol concentration is decreasing and becoming steady during the degradation process,if increase the initial concentration,the degradation rate is also increased at the beginning of reaction process,the electrodes with high performance strongly affect the first step of degradation by reducing the residence time of intermediates,the whole process and the productions of second step are primarily controlled by the first step …

Go to article

Characterization Of Dissolved Organic Matter By Separation And Fluorescence Spectroscopy, Yurong Deng Aug 2009

Characterization Of Dissolved Organic Matter By Separation And Fluorescence Spectroscopy, Yurong Deng

Chemistry and Chemical Biology ETDs

The goal of this work is to evaluate new methods of extracting and fractionating dissolved organic matter (DOM) using liquid-liquid and solid-phase extraction (SPE), monitored by optical spectroscopy. DOM in aquatic systems from different sources was characterized by three-dimension excitation-emission matrix fluorescence spectroscopy (3DEEMS) and UV absorbance spectroscopy. UV and visible humic-like fluorescence were observed in all water samples -- humic acids (HA), fulvic acids (FA), river water, wastewater, and their fractionations. Their fluorescence centers varied with environment in the range of λex/ λem = 220-250 nm/390-460 nm for UV humic-like fluorescence (peak A) and λex/ λem = 300-340 nm/390-460 …

Go to article

Total Synthesis Of (-)-Acutumine, Fang Li Aug 2009

Total Synthesis Of (-)-Acutumine, Fang Li

Theses and Dissertations

Acutumine is a tetracyclic alkaloid isolated from the Asian vine Menispermum dauricum with selective T-cell cytotoxicity and antiamnestic properties. We have developed a total synthetic route to this congested alkaloid, during which we also found a novel, stereoselective radical-crossover reaction that combines an intramolecular radical conjugate addition with a subsequent enolate hydroxylation. Key features of this synthesis also include a reagent-controlled diastereoselective ketone allylation, an anionic oxy-Cope rearrangement to form a congested quaternary sterocenter, a pyridine-mediated selective ozonolysis, and a Lewis acid promoted Michael-type cyclization.

Go to article

The Effect Of Active Techniques Combined With Didactic Lecture On Student Achievement, Melissa Martin Aug 2009

The Effect Of Active Techniques Combined With Didactic Lecture On Student Achievement, Melissa Martin

Student Theses and Dissertations

The objective of this study is to investigate the effect of active teaching methods combined with didactic lecture versus lecture alone. This project compared two sections of physical science at a community college. The study was conducted for two 15-week semesters. The control groups were taught by didactic lecture alone and the experimental groups were instructed using active techniques combined with the traditional didactic lecture. The hypothesis for this study is that the active learning sections will achieve higher scores than the passive learning sections. Data was collected from pre/post test results, chapter exams, and end-of-course final grades. The data …

Go to article

Computational Investigation Of Spin Traps Using Hybrid Solvation Models., Sai Sriharsha Manoj Konda Aug 2009

Computational Investigation Of Spin Traps Using Hybrid Solvation Models., Sai Sriharsha Manoj Konda

Electronic Theses and Dissertations

The cyclic nitrone 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and the lesser known linear phenyl-N-tert-butylnitrone (PBN) and its phosphorylated analogues have been used as spin traps for the investigation of free radicals in biological systems. Theoretical work on these molecules suggests that there are important differences in their properties between biological systems and isolated molecules in the gas phase, most likely resulting from intra and intermolecular hydrogen bonding. Most dielectric solvation models such as the polarized continuum model and COSMO are incapable of direct determination of solvent-spin trap chemical interactions. To examine this, hybrid models incorporating COSMO for long range effects and discrete solvent …

Go to article

Studies Of The Preparations And Use Of Sol-Gel For Enzyme Immobilization And Analytical Applications., Suzana Hamdan Aug 2009

Studies Of The Preparations And Use Of Sol-Gel For Enzyme Immobilization And Analytical Applications., Suzana Hamdan

Electronic Theses and Dissertations

Much attention has been paid to immobilization of enzymes to improve enzyme stability and permit its reuse. Glucose oxidase entrapment in different kinds of silica sol-gel matrices was investigated. The enzyme showed stable activity for 11 uses in the sol-gel with tetramethyl orthosilicate (TMOS) as precursor, and at least 7 uses in the sol-gel induced electrochemically with tetraethyl orthosilicate (TEOS) as precursor. The sol-gel made with TEOS as precursor and HCl as catalyst showed stability in enzyme activity for 11 uses but the activity decreases on the same sol-gel when modified with silica nanoparticles. Factors such as optimal incubation time …

Go to article

Novel Strategy For The Synthesis Of Allenes., Mark-Henry Mbahmi Kamga Aug 2009

Novel Strategy For The Synthesis Of Allenes., Mark-Henry Mbahmi Kamga

Electronic Theses and Dissertations

Allenes are very important chemical reagents in organic synthesis. Due to their high reactivity, they have been extensively used to carry out a variety of unique and effective chemical transformations including but not limited to ionic and free radical additions and transition metal catalyzed cyclizations. As the chemistry of this group of compounds is explored further and their applications expanded there is a need to develop alternative and cost effective methods for their synthesis. Our approach involves the synthesis of allenes from oxa-bicyclo-alkan-2-ones by methyllithium induced Eschenmoser fragmentation of the bicyclotosylhydrazone derivatives.

Go to article

Studies Of Capsaicinoids Contents Of Locally Grown And Commercial Chilies Using Reversed-Phase High Performance Liquid Chromatography., John Kailemia Muchena Aug 2009

Studies Of Capsaicinoids Contents Of Locally Grown And Commercial Chilies Using Reversed-Phase High Performance Liquid Chromatography., John Kailemia Muchena

Electronic Theses and Dissertations

Capsaicinoids are a class of compounds responsible for the "heat" of hot peppers. Capsaicin and dihydrocapsaicin have the highest burning effect. The aim of this work is to separate and quantify the two major capsaicinoids in fruits harvested at different stages of development and at different seasons. Simple and rapid HPLC method involves 73:27% methanol water mobile phase with C18 stationary phase and UV-Vis detector set at 210 nm. The method showed good reproducibility with 1.74% - 4.72% relative standard deviations, a linear response within 0.65–45.5 and 0.25-17.5 μg/mL for capsaicin and dihydrocapsaicin, respectively. The method achieved average recovery …

Go to article

Studies Of Titanium Dioxide Nanoparticles And Surfactants Effects, Singly And In Combinations, On Luminescence Intensity Of Some Aromatic Compounds., Charles Anim Odame-Ankrah Aug 2009

Studies Of Titanium Dioxide Nanoparticles And Surfactants Effects, Singly And In Combinations, On Luminescence Intensity Of Some Aromatic Compounds., Charles Anim Odame-Ankrah

Electronic Theses and Dissertations

Luminescence techniques are sensitive, selective, and widely used in analysis. Luminescence intensity is attenuated by quenchers. This research has focused on the use of surfactants such as CTAB, SDS, and TX-100 singly or together with TiO2 nanoparticles to evaluate their individual and combined effects on some fluorescent aromatic compounds such as pyrene, fluoranthene, anthracene, phenanthrene, and carbazole. Rutile phase TiO2 was synthesized using the low temperature sol-gel method. Carbazole and phenanthrene were severely quenched by all surfactants singly or in combination with TiO2. Anthracene and fluoranthene showed some enhancement in their luminescence intensity. The most dramatic …

Go to article

Cardiac And Renal Function Are Progressively Impaired With Aging In Zucker Diabetic Fatty Type Ii Diabetic Rats, John W. Baynes, David B. Murray Aug 2009

Cardiac And Renal Function Are Progressively Impaired With Aging In Zucker Diabetic Fatty Type Ii Diabetic Rats, John W. Baynes, David B. Murray

Faculty Publications

This study investigated the temporal relationship between cardiomyopathy and renal pathology in the type II diabetic Zucker diabetic fatty (ZDF) rat. We hypothesized that changes in renal function will precede the development of cardiac dysfunction in the ZDF rat. Animals (10 weeks old) were divided into four experimental groups: Lean Control (fa/?) LC(n = 7), untreated ZDF rats (n = 7) sacrificed at 16 weeks of age, and LC (n = 7) untreated ZDF rats (n = 9) sacrificed at 36 weeks of age. LV structural/functional parameters were assessed via Millar conductance catheter. Renal function was evaluated via markers of …

Go to article

Single Molecule Force Spectroscopy On G-Quadruplex Dna, Susanna Lynch, Heather Baker, Sarah G. Byker, Dejian Zhou Aug 2009

Single Molecule Force Spectroscopy On G-Quadruplex Dna, Susanna Lynch, Heather Baker, Sarah G. Byker, Dejian Zhou

University Faculty Publications and Creative Works

A study was conducted to demonstrate the first atomic force microscopy (AFM) based investigation of single-molecule (SM) force spectroscopy (FS). A bimolecular G-quadruplex formed between the AFM probe and a gold surface was used as the model system to conduct the investigations. A gold-coated Si 3N4 probe and a flat gold surface were functionalized with a self-assembled monolayer (SAM) of the 3G or 4G DNA. A loading rate dependence investigation was conducted to estimate kinetic and thermodynamic parameters of the 3G and 4G quadruplexes. Rupture forces were measured at loading rates ranging from 1027-43 500 pNs-1. It was observed that …

Go to article

Single Molecule Force Spectroscopy On G-Quadruplex Dna, Susanna Lynch, Heather Baker, Sarah G. Byker, Dejian Zhou Aug 2009

Single Molecule Force Spectroscopy On G-Quadruplex Dna, Susanna Lynch, Heather Baker, Sarah G. Byker, Dejian Zhou

University Faculty Publications and Creative Works

A study was conducted to demonstrate the first atomic force microscopy (AFM) based investigation of single-molecule (SM) force spectroscopy (FS). A bimolecular G-quadruplex formed between the AFM probe and a gold surface was used as the model system to conduct the investigations. A gold-coated Si 3N4 probe and a flat gold surface were functionalized with a self-assembled monolayer (SAM) of the 3G or 4G DNA. A loading rate dependence investigation was conducted to estimate kinetic and thermodynamic parameters of the 3G and 4G quadruplexes. Rupture forces were measured at loading rates ranging from 1027-43 500 pNs-1. It was observed that …

Go to article

Structural Basis For Α-Conotoxin Potency And Selectivity, Matthew Turner, Seth Eidemiller, Bryan Martin, Andrew Narver, Joshua Marshall, Kenneth A. Cornell, Owen M. Mcdougal Aug 2009

Structural Basis For Α-Conotoxin Potency And Selectivity, Matthew Turner, Seth Eidemiller, Bryan Martin, Andrew Narver, Joshua Marshall, Kenneth A. Cornell, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Parkinson's disease is a debilitating movement disorder characterized by altered levels of α6β2* nicotinic acetylcholine receptors (nAChRs) localized on presynaptic striatal catecholaminergic neurons. α-Conotoxin MII (α-CTx MII) is a highly useful ligand to probe α6ß2 nAChRs structure and function, but it does not discriminate among closely related α6* nAChR subtypes. Modification of the α-CTx MII primary sequence led to the identification of α-CTx MII[E11A], an analog with 500-5300 fold discrimination between α6* subtypes found in both human and non-human primates. α-CTx MII[E11A] binds most strongly (femtomolar dissociation constant) to …

Go to article

Toward Charge-Neutral ‘Soft Scorpionates’: Coordination Chemistry And Lewis Acid Promoted Isomerization Of Tris(1-Organo-Imidazol-2-Ylthio)Methanes, Chengeto Gwengo, Rosalice M. Silva, Mark D. Smith, Sergey V. Lindeman, James R. Gardinier Aug 2009

Toward Charge-Neutral ‘Soft Scorpionates’: Coordination Chemistry And Lewis Acid Promoted Isomerization Of Tris(1-Organo-Imidazol-2-Ylthio)Methanes, Chengeto Gwengo, Rosalice M. Silva, Mark D. Smith, Sergey V. Lindeman, James R. Gardinier

Chemistry Faculty Research and Publications

Two tris(1-organo-imidazol-2-ylthio)methanes, HC(S-timR)3 (R = organo = methyl, tert-butyl), have been prepared by a triphasic reaction between chloroform, the appropriate heterocycle, and saturated aqueous solutions of Na2CO3, in the presence of a phase transfer agent, (NBu4)(Br). These ligands have been characterized both spectroscopically and by single crystal X-ray diffraction. The reaction chemistry of these potentially N,N,N-tripodal ligands with AgBF4 was also explored where simple 1:1 coordination complexes could be isolated from reactions performed in THF solution at room temperature. The derivative {Ag[HC(S-timMe)3]}(BF4) was structurally …

Go to article

First Prev Next Last