Physical Sciences and Mathematics Commons^™

The Electrochemical Reduction Of 2-Ethylanthraquinone(2eaq), Yaobin Zhu

Journal of Electrochemistry

The process of electrochemical reduction of 2EAQ in DMSO is studied using CVand ESR methods in this work, Pt, Pd and some implanted materials are used as electrodes. Thequasi-rever+sible property of two electron transfer steps and their following homogeneous chemicalreactions are illustrated,The mechanism of the electrochemical red uction of 2 EAQ and the kineticparameters of the related steps are obtained. Having measured the influence of water content in thesystem, the effect of the proton donor is discussed. After comparising the experimental results witheach other these experiments gives us the idea that the replacement of metal Pd or some Pd-catalystswith pd-implanted …

Study On The Electron Transfer Process Of Cytochrome C With Different Charge Transfer Promoters, Guoxin Tang

Journal of Electrochemistry

The diffusion coefficient D. standard rate constant and transfer coefficient afor electron transfer process of cytochrome C at OTTLE in the presence of 4,4'-Dithiedipyridine(PySSPy),Adenine and L-Cysteine were determined by the chronoadsorptometric technique with Au-OTTLE. A computer fitting method was used to calculated these kinetic parameters.The mechanismsof PysSPy,Adenine and L-Cysteine were used as the promoters,and were also discussed.

Study Of The Electrochemistry Of Systems Of Practical Importance, Chuansin Cha, Juntao Lu

Journal of Electrochemistry

Research projects mainly of the following two categories have been carrying on inthis laboratory:1.Development of experimental electrochemical methedes,including traditional electrochemicaland spectro-electrochemical techniques suitable for the study of practical electrochemical systems,suchas porous electrodes,powdery materials,hazardous(toxic,explosive)systems,etc.2.Study of electrochemical systems possessing practical importance,including mechanistic andelectrocatalytic studies.The studied electrochemical systems are mostly related to electrochemicalpower sources,electrochemical sensors and electrochemical synthesis.

A Sutface-Enhanced Raman Spectroscopic Study On The Inhibition Mechanism Of Bmat On Stainless Steel In Hydrochloric Acid Solutions, Yinghua Zha, Baoming Wei

Journal of Electrochemistry

The absorbtion of some nitrogen and sulfur compounds such as BMAT on 18-8stainless steel(SS)in 0.5% HCl were investigated by surface enhanced Raman scattering(SERS)spectroscopy.The SERS spectra of BMAT adsorbed on SS were measured using a SS electredepositedwith discontin uous silvet micro-islands.The results show that the inhibitor,BMAT,is chemisorbed onthe SS surface through the N atom. Under the influence of π-electron interaction ,BMAT can beadsorbed on SS surface at an angle. The allyls in BMAT molecules play the role of steric hindrance inthe inbibition effect.

The Effects Of Magnetic Field Onthe Electropolymerization Of Aniline, Lintao Cai, Shibing Yao, Shaomin Zhou

Journal of Electrochemistry

The aniline electropolyinerization under the magnetic field was studied by cyclicvoltammetry and potentiostatic step techniques. Theinaximum peak current was obtained at 0. 58 Twhen the magnetic flux was perpendicular to the surface of the working electrede in H_2SO_4 solution.These were speculated in terins of magnetic dircctional effect. But when the magneic flux directed inparallcl with the surface of elcctrode, the peak current obviously increased as the magnetic flux densityrised. The results uere explained as the enhancement of mass transfer by magnetohydredynamic(MHD) mechanism. The PAN film growth via a two-dimentional (2-D) instantaneous nucleationunder the electron transfer kinetic controlled. The enhanced effects …

Laser Scanning In-Situ Photoelectrochemical Microscopictechnique And Its Applications, Zugeng Lin, Jinkua You, Xiangdong Zhuo, Chun Zhang, Yong Yang

Journal of Electrochemistry

Abstract The main factors of the laser scanning in-situ photoelectrochemical microscopicmeasurement system which is set up in our lab have been discusaed in this paper. Some applications ofthis technique for insttn study of medificiition and processing of semiconductor electrodes , monitoringof electredeposition process of semiconducting material and redox reaction occurring at metal oxideelectrodes have aiso been presented. The results have shown that the technique is very powerfui thatfor studing local photoelectrochemical properties of semiconductors and metal oxide electredes. Theseprovide important information on the micro structural and electronic properties in the solidlelectrolyteinterface.AbstractLaser scanning, Local photocurrent spectroscopy, Photoelectrochemical,Semiconductor electode

Studies Of The Black Molybdate Conversion Film On Stainless Steel, Jingli Fang, Liuqin Liuqin, Keping Han, Yaohui Chen

Journal of Electrochemistry

A black conversion film was formed on stainless steel with cathodicelectrodeposition method from a molybdate-phosphate solution. This film displayed goodthemcotability. The results of XPS and AES analysis showed that the thickness of the film was 820 nmand that Mo existed as Mo(Ⅵ)in the surface of the film,while existed as Mo(Ⅵ)and Mo(Ⅳ)in theinternal layer of the film. The relative atomic percent content(A,C.% of the film obtained from theelemental composition constant region of the depth profile curves by AES was O 50.9%,Mo 29.4%,P12.6%and Fe 7.1%respectively.The cyclevoltammetric oxluation peak also showed that Mo(Ⅳ)existed in the internal layer of the film.

An Indirect Electrochemical Oxidation Of Toluene──Anodic Oxidation Of Mn(Ⅱ) On The Lead Electrode, Zhonghua Wang, Qingmin Hua, Guaeai Chen

Journal of Electrochemistry

The electrochemical oxidation of Mn (Ⅱ) to Mn(Ⅱ) in concentrated H_2SO_4(2￣8 mol . L-1) at lead electrede has been studied. It is found that the electrede surface is oxidized toPbO_2 in a direct electrochemical reaction, then PbO_2formed reacts with Mn (Ⅱ) in a chemicalreaction. Some effects involves current density , concentration of H_2SO_4 , temperature and conversionwere evaluated. The rule of electrogenerated Mn (Ⅲ) in flow electrolysis cell were determined atseveral conditions. The current efficiency at greater than 90% is obtained in general.

Electrochemically Modified Glassy Carbon Electrode And Determination Of Copper By Anodic Stripping Voltammetry, Jinrui Xu, Yie Liu, Xiurun Zhuang

Journal of Electrochemistry

This paper reported the glassy carbon electrode modified by cyclic voltammetrybetween-0. 1and + 1. 5 V(vs. SCE)in an aqueous solution containing catechol,formaldehyde andtalium hydroxide. The modified electrode can be applied to the determination of copper(Ⅱ) in water,and its sensitivity is about 35 times higher than that of unmedified glassy carbon electrede, Thequantitative limit with this modified electrede is 0. 1 ng/ml.

The Reduction Of Oxygen To Hydrogen Peroxide At The Poly(O-Phenylenediamine)-Filmed Electrode, Zhaoe Lu, Tiangeng Zhong, Guanyong Zhang

Journal of Electrochemistry

The poly(o-phenylenediamine)(PPD)filmed graphite electrode was formed byelectro-polymerization of o-phenylenediamine in acidified(pH=1)0.2 mol·L-1 Na_2SO_4 solutionusing the cyclic voltammetric methed. The catalytic effect of the electrcareduction of oxygen in acidsolution was demonstrated by the voltammogram of the electrede in the oxygen saturated acid solutionof Na_2SO_4. The current efficiency of the reduction of oxygen to hydrogen peroxide was determined byIhe electrolysis in a divided cell under the condition of constant current. The various effectsinfluencing the accm ulation of H_2O_2 in the catholyte were discussed.

Studies On Coordination Behavior Of Dimethyl Sulfoxide In Complex Of Rare Earth With Cryptand, Shichang Liu

Journal of Electrochemistry

lectrochemical reduction reaction in the course of the titration of Eu ( 2.2.2)and Eu( 2.2)using strong bonding solvent,DMSO,in C_2H_4Cl_2 has been investigated by cyclicvoltammetry. The greater the concen tration of strong bonding solvent,the more negative the half-wave potentials for the reduction reaction are. The coordination number of Eu(2.2.2 ) and Eu(2.2)which are 2 and 3 respectively,with DMSO can be calculated,according to the relations betweenhalf -wave potentials and the variety of concentration of DMSO.

Electrochcmical Reaction Of Redoxproteins Speeded Up By The Dye Modified Electrodes, Ting Chen, Shaojun Dong, Yuanwu Xie

Journal of Electrochemistry

The electron transfer reaction of redox proteins faciliated by dye medifiedelectrede was reviewed in this paper.The medification metheds and the properties of dye modifiedelectrede were discussed. Several different studying metheds,such as voltammetry,flow analysis andspectroelectrochemical methed,were reviewed.Areversible electrocatalytic reaction mechanism wasproposed and verified by comparing the digital calculation results with the experimental results.47references were cited.

Photoelectrochemical And Spectroelectrochemical Studies Oniron Oxide Ultrafine Particles, Maizhi Yang, Yongjun Ji, Wen Zhang, Shengmin Cai

Journal of Electrochemistry

in this paper, Raman spectra, photocurrent and the UV-VIS reflectance aremeasured for studying the α-Fe_2O_3ultrafine particles adsorbed on Pt electrode. The blue shifts ofRaman peaks demonstrate the size quantization effect for the particles of 50 nm in diameter ascompared with the bulk material. With the changing of the potential , the photocurrent decrcases as theUV-VIS reflectance increases, and vice-versa. Therefore, the potential not only affects the hargetransfer direcdtion in the interface of electrede/redox couple, but also influences the light absortion onthe surface of particles.According to the results of photoelectrochemistry, we suggest that the cathedicphotocurrent in the potential range of more …

Horseradish Peroxidase/Poly-O- Phen Ylenediamine Mem Brane Electrode:Preparation And Properties, Dong Wei, Huihuang Wu

Journal of Electrochemistry

A horseradish peroxidase(HRP)/poly-o-phenylenediamine(PPD)membraneelectrede was prepared by electropolymerization of o-phenylenediamine on glassy carbon in pH 7.0phosphate buffer,the process of the enzyme immobilization was studied,The enzyme electredeobtained exhibits the activity to catalyze the electrored uction of hydrogen peroxide in the absence ofany electron transfer mediator.The red uction reaction occurs in the potential range of PPD redoxprocess,it was believed that the polymer participates in electron transfer of the enzyme.The enzymereaction kinetics at rotating H RP/PPD electrede was analysed,and the factors influencing kineticparameters were discussed.

The Formation And Voltammetric Behavior Of Manganese Chlorophyll, Qingdong Qiao

Journal of Electrochemistry

The formation and voltam metric behavior of manganese chlorophyll werestudied.The electrochemical red uction mechanism of Mn chlorophyll a (MnChla)in aqueous solutionwas investigated and discussed.During the electrored uction of MnChla ,the porphyrin ring was singlyreduced with 2 electrons and the Mn￣(2+) ion remained its original state,The reduction rate constant k_m=0.36/s was gained.

Use Of Fractals And Kinetic Equations To Model Thermally Induced Hillock Formation And Growth In Thin Metal Films, Joseph Chaiken, Jerry Goodisman

Chemistry - All Scholarship

We investigated the applicability of a model based on fractals and the Smoluchowski kinetic equations to describe hillock formation in thin metal films. We have previously used this model to analyze cluster and ultrafine particle production. We show how to extract two parameters from measured hillock size distributions which may reveal the scaling of the mobility of clusters and vacancies in films with varying hillock size. On the basis of our application of this model to certain data taken from the literature, the model shows considerable potential for being able to provide an internally consistent quantitative basis for monitoring thermally …

Transitions In Masculinity And Hemingway's Developed "Code", Daniel Polk

Honors Theses

The "Hemingway Code" is much more than two words that fit nicely together for a scholar's usage; the words signify a much deeper championing of masculinity, almost a haunting presence. For Ernest Hemingway living life every day, every moment with its fullest masculine fervor, became an obsession, a never-ending quest to be at one with the attitude of never complaining, never crying out, panicking, thinking too much, or regretting. To live a manly life in a series of tactical victories, performed with steadfast ritualistic mannerisms, is to embody masculinity, and therefore the "Hemingway Code."

Electrocrystallization Of Strongly Adherent Brushite Coatings On Prosthetic Alloys (Continuation), Jody G. Redepenning

Chemistry Department: Faculty Publications

An electrolytic method for providing bone-emulating, phosphate coatings on prosthetic appliances. Such coatings serve to enhance bone furation after implantation of the appliances. The method of the invention is an electrolysis process wherein the appliance to be coated is immersed in a phosphate-containing electrolyte to serve as the cathode of the electrolysis process. When current is appIied to the electrolysis cell, the electrolyte solution, which includes calcium ions and dihydrogen phosphate ions, is caused to rapidly increase in (localized) pH proximate the cathode element. The localized pH increase creates a supersaturated local condition causing less soluble calcium phosphate salts to …

Dna Interstrand Crosslinking Efficiencies, Sequence Preferences, And Organic Syntheses Of Diepoxide Metabolites In Fixation, Sara Charnecki

Honors Theses

Molecular Basis of Cancer: Cancer, a disease that has had a devastating and frightening impact on current society in the midst of a chemical revolution, represents a class of diseases comprising over 200 known types that affect various regions of the mammalian body (Farmer & Walker, 1985). This disease strikes randomly and is often diagnosed after the disease has progressed beyond present treatment capabilities. Cancer is the result of irregularities in growth, reproduction, and differentiation of cells due to pennanent flaws in genetic information. Mutations caused by environmental factors can be compounded over time to cause carcinomas of different tissues. …

Electrochemical Carbonylation Of Organoiron Methyl Complex: A Study Of Reaction Intermediates, C. Amatore, Mekki Bayachou, J. N. Verpeaux, L. Pospisil, J. Fiedler

Chemistry Faculty Publications

The one-electron reduction of CpFe(CO)2CH3 has been investigated by voltammetry and Fourier transform IR spectroelectrochemistry. The reduction initiates the insertion of CO ligand in the FeCH3 bond. The dissociation of a CO group proceeds in a parallel reaction. Reaction intermediates, the acyl derivative and released CO, form the radical anion of a complex CpFe(CO)2(COCH3) which is able to reduce the parent compound. The reversible redox potential − 1.8 V of CpFe(CO)2(COCH3) allows the regeneration of its radical anion which drives a catalytic cycle. The lifetime of intermediates is shortened by side reactions, one of which is the migration of the …

Studies Directed Toward Enantioselective Catalysis, Brian E. Jones

Open Access Master's Theses (through 2010)

Many organic molecules of modest size and complexity have chirality.That is, these molecules can exist in more than one stereoisomeric form.There is a strong desire to synthesize chiral compounds that exist in the form of a single stereoisomer.The method of synthesizing chiral compounds that was studied in our research employed a less than stoichiometric amount of chiral catalyst to both catalyze and control the stereochemical outcome of the reactions attempted.

A new chiral ligand was developed to be used as part of the chiral catalyst.This new ligand was used in the enantioselective Diels-Alder cycloaddition reaction and the enantioselective allylation reaction …

Synthesis Of Nitrosyl Metallpoprphyrins, Thomas M. Braxton Jr.

McCabe Thesis Collection

Nitric oxide, NO, is a molecule with great versatility and importance. Made up of only a single atom of nitrogen and a single atom of oxygen, nitric oxide is perhaps one of the smallest paramagnetic molecules found in nature. The functions of NO in the body are not all known, but this molecule definitely plays a variety of roles. It is involved in the regulation of blood pressure, and it sometimes acts as a messenger for cells as well as a killer of them. It also is important in the defense of the body against foreign invaders. The significance of …

59. Otto Kratky, 1902-1995, Otto Vogl, Josef Schurz

Otto Vogl

No abstract provided.

Iron-Dithiothreitol Dependent Production Of 8-Hydroxy-2'-Deoxyguanosine In Dna, David Allan Cook

Undergraduate Honors Capstone Projects

Oxidative damage to DNA in a metal-thiol system was studied. Calf thymus DNA was incubated in an iron(IIl)-dithiothreitol system prepared in various buffers. Damage was measured by monitoring the production of 8-hydroxy-2'-deoxyguanosine. DNA oxidation was proportional to the concentration of dithiothreitol (DTT) in HEPES and tris(hydroxymethyl)aminomethane (Tris) buffers while it was only roughly related to DTT concentration in sodium chloride. Incubation in potassium phosphate buffer produced no damage. The results indicate that hydroxyl radicals may be generated by the iron-OTT system in HEPES, Tris, and sodium chloride, while in the phosphate buffer an iron phosphate complex may be formed which …

Primase Structure And Function, Mark A. Griep

Chemistry Department: Faculty Publications

Primase is the ssDNA-dependent RNA polymerase that synthesizes RNA primers during DNA replication. In common with all DNA and RNA polymerases, primase has structural and functional features involved in polymer elongation. As RNA polymerase, it has structural and functional features for initiating chain synthesis. As a primase, it has structural and functional features for initiating chain synthesis on ssDNA. Using amino acid sequence analysis the structure of Escherichia coli primase responsible for binding zinc, at least three magnesium, and DnaB helicase has been identified. One of the magnesium binding motifs resembles the “active magnesium” motif found in all DNA and …

60. Teiji Tsuruta, Otto Vogl

Otto Vogl

No abstract provided.

Accuracy Of Deoxynucleotide Incorporation By Soybean Chloroplast Dna-Polymerases Is Independent Of The Presence Of A 3' To 5' Exonuclease, J. Clinton Bailey Ii, Sabine Heinhorst, Gordon C. Cannon

Faculty Publications

DNA polymerase was purified from soybean (Glycine max) chloroplasts that were actively replicating DNA. The main form (form I) of the enzyme was associated with a low level of 3' to 5' exonuclease activity throughout purification, although the ratio of exonuclease to polymerase activity decreased with each successive purification step. A second form (form II) of DNA polymerase, which elutes from DEAE-cellulose at a higher salt concentration than form I, was devoid of any exonuclease activity. To assess the potential function of the 3' to 5' exonuclease in proofreading, the fidelity of deoxynucleotide incorporation was measured for form I DNA …

Structural Effects On Micellar Catalyzed Hydrolysis Of Hydroxamic Acids With Perfluorooctanoic Acid As Surfactant, Xing Zhang

Masters Theses

This thesis demonstrated the structural effects on micellar catalyzed hydrolysis of hydroxamic acids with prefluorooctanoic acid as the reactive counterion surfactant in aqueous acetonitrile solution.

For different hydroxamic acids, the observed pseudo-first order rate constant-surfactant concentration profiles were obtained and were used in the determination of critical micellar concentrations (cmc).

The micellar catalytic effect was satisfactorily explained by the pseudo-phase ion exchange (PPIE) model. The PPIE model was successfully applied in the determination of the reaction rate constants both in the water phase and in micellar pseudo-phase.

Further investigation into more appropriate hydroxamic acids is suggested in order to obtain …

Structural Characterization Of A Novel Inhibitor Of Hiv Reverse Transcriptase (Hiv Rt), Greggory Jon Woitte

Chemistry & Biochemistry Theses & Dissertations

Human immunodeficiency virus (HIV) infections have become a leading cause of death among young people in the United States today. As the number of HIV infections increases, so too does the cost of treatment. Together, these numbers have prompted an increase in the development of pharmaceutical interventions. HIV reverse transcriptase (HIV RT) has become a suitable target for drug therapy because it is the sole enzyme responsible for HIV replication.

Fucoidan, a sulfated polysaccharide isolated from the brown algae Fucus vesiculosus, has been shown to block a variety of cell adhesion related events including metastasis. In addition, fucoidan has also …

"Be Not Afraid", Juana Acrivos

Faculty Publications, Chemistry

If l asked what am I doing here? the answer should be that I am here to recount the experience of a condensed matter scientist teaching frontier chemical physics at a so called "Undergraduate Institution with ≈47% Minorities" But should one distinguish undergraduate from graduate ability, minority from non-minority ability to do frontier science that shall benefit everyone? I hope to convince you the answer is no; the title of my address was borrowed from Pope John Paul's recent best seller in order to have the courage to do the job. This attitude is probably no different from anyone else …