Physical Sciences and Mathematics Commons^™

Multifragmentation In E/A=35 Mev Collisions: Evidence For A Coulomb Driven Breakup?, M. D'Agostino, G. J. Kunde, P. M. Milazzo, J. D. Diniu, M. Bruno, N. Colonna, M. L. Fiandri, C. K. Gelbke, T. Glasmacher, F. Gramegna, D. O. Handzy, W. C. Hsi, M. Huang, M. A. Lisa, W. G. Lynch, P. F. Mastinu, C. P. Montoya, A. Moroni, Graham F. Peaslee, L. Phair, R. Rui, C. Schwarz, M. B. Tsang, G. Vannini, C. Williams

Faculty Publications

Multifragment disintegrations have been measured for central Au+Au collisions at EA=35 MeV. Fragment emission occurs predominantly at low center of mass energies of about EA≈5 MeV, consistent with a Coulomb dominated breakup of a single source. Mean fragment multiplicities of ⟨NIMF⟩≈10.8 are extracted after correction for the detection efficiency. The fragment charge distributions decrease much more gradually than expected from scaling laws recently applied to the extraction of critical exponents for the nuclear liquid-gas phase transition from nuclear collisions.

Croatian Symposium Of Chemistry And Macromolecular Chemistry, Otto Vogl, Zvonimir Janovic

Emeritus Faculty Author Gallery

No abstract provided.

Polymer Science In Australia Iv. Universities In Victoria And Southern Australia, Otto Vogl, David Solomon, Ezio Rizzardo, Robert A. Shanks, David Williams

Emeritus Faculty Author Gallery

No abstract provided.

52. Bengt Ranby, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.

Croatian Symposium Of Chemistry And Macromolecular Chemistry, Otto Vogl, Zvonimir Janovic

Otto Vogl

No abstract provided.

Polymer Science In Australia Iv. Universities In Victoria And Southern Australia, Otto Vogl, David Solomon, Ezio Rizzardo, Robert A. Shanks, David Williams

Otto Vogl

No abstract provided.

52. Bengt Ranby, Otto Vogl

Otto Vogl

No abstract provided.

Synthesis And Characterization Of A Water-Soluble Metallopeptide That Resembles A Parallel Beta-Pleated Sheet, Michael Y. Ogawa, Alexei B. Gretchikhine, Sunil-Datta Soni, Steven M. Davis

Chemistry Faculty Publications

The title metallopeptide consists of two divalinyl peptides attached to the carboxylate groups of the ruthenium polypyridyl complex. [Ru(bpy)(2)L](2+): bpy = 2,2'-bipyridine; L = 3,5-dicarboxy-2,2'-bipyridine. The charged ruthenium complex is water soluble and is shown by variable temperature, and 2-D NMR to consist a parallel arrangement of interacting, extended peptide strands that ir reminiscent of the beta-sheet structure. Circular dichroism results support this assignment.

Prompt And Sequential Decay Processes In The Fragmentation Of 40 Mev/A 20ne Projectiles, R. J. Charity, L. G. Sobotka, N. J. Robertson, D. G. Sarantites, J. Dinius, C. K. Gelbke, T. Glasmacher, D. O. Handzy, W. C. Hsi, M. J. Huang, W. G. Lynch, C. P. Montoya, Graham F. Peaslee, C. Schwarz, M. B. Tsang

Faculty Publications

The fragmentation of E/A=40 MeV Ne20 projectiles into exit channels containing only p, d, t, He3, α, He6, Li6, and Li7fragments has been investigated. Relative shifts between the average longitudinal velocity of each fragment type were measured with Sn120 and Au197 targets. A post-breakup Coulomb acceleration component of these shifts was isolated. Its magnitude indicates that the projectile broke up while in near contact with the target. On the other hand, correlations between projectile fragments indicate that a significant fraction of these fragments are produced by the sequential decay of long- and short-lived unstable intermediates. A fully sequential decay process, …

The Separation Of Aqueous Iron Species Found In Stepwise Complexation By Capillary Electrophoresis With Atomic Absorption Spectroscopy Detection, Robert E. Sutton

Dissertations

A capillary zone electrophoresis system was interfaced to an atomic absorption spectrom eter to permit the separation and detection o f various species of iron found in step wise complexation in aqueous solutions. The samples were introduced at the anodic end of the column employing the electroosmotic flow to drive all the species to the detector at the cathodic end. Aqueous solutions of iron(II) and iron (III) chloride salts were among the compounds studied. The buffer employed w as a 20 millimolar (2-[N-morpholino]ethanesulfonic acid adjusted to a pH of 6 with 6 .6 millimolar potassium hydroxide. The detection limit was …

Model Of Chlorocarbon (Cfc-12) Chemisorption On Solid Rocket Motor Alumina Exhaust Particles, Gary E. Lund

Theses and Dissertations

Solid Rocket (SRMs) that power Titan IV rockets and Space Shuttles, exhaust large quantities of potentially ozone damaging pollutants directly into the stratosphere, while in powered flight. In the past, studies on potential stratospheric impact of the exhaust products from aluminum/ammonium perchlorate based SRMs have focused on the effect of gaseous HCl from SRMs on the stratosphere. Until recently, the impact of heterogeneous chemistry on stratospheric ozone was believed to be relatively insignificant. This research investigates the potential heterogeneous process of CFC-12 dissociative chemisorption on alumina surfaces and the release of reactive halogen species known to destroy ozone. Through a …

Effects Of Insulin And Insulin Mimetics On Antioxidant Enzyme Levels: In Vivo And In Vitro, Shikha Varma

Masters Theses

Tissue antioxidation status is considered to be an important factor for elucidating the etiology of diabetes and its physiological complications. This study was aimed to determine the in vivo antioxidant enzyme levels in the altered antioxidant status of diabetic rat liver with the treatment of two potent insulin mimetics, vanadium and selenate. The direct effects of vanadate, selenate, and zinc (another insulin mimetic) on the antioxidant enzyme levels in primary rat hepatocytes in culture was also determined. Levels of superoxide dismutase (SOD), catalase (CAT) and gluthahione peroxidase (GPX) were determined in both model systems.

In the vivo model, insulin treatment …

Regulation Of The Expression Of Lipogenic Enzymes By Insulin-Mimetics, Juiyu Wu

Masters Theses

Many researchers have shown that selenate (SeO₄^2-) and vanadate (VO₄^2-) have insulin-mimetic effects in certain biological processes. These mimetic effects include increasing glucose transport, regulating glycolytic enzymes, normalizing plasma glucose levels and activities of insulin regulated enzymes in diabetic rats. To clarify the functions and roles of these insulin-mimetics in different insulin-regulated metabolic pathways, the expression of the genes for glucose-6-phosphate dehydrogenase (G6PDH) and fatty acid synthase (FAS) were investigated. G6PDH is a key enzyme in the pentose phosphate pathway and is also involved in lipogenic metabolism by providing 55-70% of the NADPH utilization …

Study Of The Long-Term Desorption Of Trichloroethylene From Clay Soils Using Infrared Spectroscopy, Mary P. Stager

Theses and Dissertations

Slow desorption of contaminants from soil presents one of the greatest challenges to modeling contaminant fate and transport and implementing effective remediation technologies. The kinetics of long-term desorption of trichloroethylene (TCE) from powdered clay soils were studied to determine the desorption rates and mechanism. Infrared absorption spectroscopy was used to monitor the concentration of TCE desorbed from contaminated flint clay for 71 hours. Observed gas phase TCE concentrations as a function of time were compared to that predicted by a one-site Langmuir desorption mechanism. The Langmuir model, with a single type of bonding site, did not account for the release …

Atmospheric Transport And Diffusion Modeling Of Rocket Exhaust, Chad A. Burel

Theses and Dissertations

Space launches at Vandenberg Air Force Base (VAFB) and the Cape Canaveral Air Station (CCAS) produce exhaust from the solid rocket boosters and liquid hypergolic fuels containing several toxic substances including hydrogen chloride and hydrazine. In order to estimate the health risk that would be imposed upon the public by proposed launches, range safety officials rely on the Rocket Exhaust Effluent Diffusion Model to predict where the exhaust chemicals will go after the launch and how strong the concentrations will be. The original REEDM program averaged the meteorological parameters (wind speed, wind direction, shear, etc.) across the entire mixing level …

Effects Of Ammonium Perchlorate On The Thyroid Hormone Levels Of The Sprague-Dawley Rat, James H. King Jr.

Theses and Dissertations

The purpose of this research was to determine the threshold dose for ammonium perchlorate (AP) in the Sprague-Dawley rat. No dose response data exist for AP and the EPA has studied literature on the subject of perchlorates to determine a provisional reference dose. The Perchiorate Group, a consortium of DoD and industry representatives, believes this provisional reference dose is too conservative. This experiment was executed to provide dose response data on which to base a more accurate reference dose. The study consisted of eight groups of 12 Sprague-Dawley rats, six male and six female, which were exposed to incremental doses …

Upper-Tropospheric Aerosol Sampled During Project Fire Ifo Ii, Donald E. Hagen, Josef Podzimek, Max B. Trueblood

Physics Faculty Research & Creative Works

Aerosols can play a role in the cloud formation process through the heterogeneous nucleation mechanism, and in turn, once formed, cirrus clouds can impact the ambient aerosol through scavenging and other collection mechanisms. University of Missouri aerosol sampling facilities were employed on aircraft for in situ collection and characterization of the particulates near cirrus cloud level. Tandem differential mobility analyzer and impactor techniques were used to measure aerosol size distribution, hydration capability, and particle composition information. Evidence of aerosol layering was observed near the tropospause, and there was a tendency toward depletion of the ambient aerosol at both ends of …

Application Of Polarization Modulation Infrared Reflection Absorption Spectrscopy To Study The In Situ Structure Of Electrodes Modified With Alkanethiol, Mark Anderson

Mark R. Anderson

No abstract is currently available.

Developments Of Fundamental Studies In Modern Electrochemistry──A Lecture For The National Advanced Workshop Of Modern Electrochemistry, Zhaowu Tian, Wenduan Su

Journal of Electrochemistry

This paper is a lecture notes spoken by profesor Tian to the national advancedworkshop of modern electrochemistry.The developments of fundamental studies of modernelectrochemistry are reviewed.outline of this subject as follows. 1. Importance of science and technology in electrochemistry 1.1 Electrochemical phenomena exist every where in nature1.2 Extensive applications of electrochemical technology 2.Electroch6mical systems and researches 2.1Characteristics 2.2Advantages 2.3Difficulties3.Advance the modern electrochemical fundamental study at atomic-molecular level3.l Comparisons between traditional and modern electrochemical studies 3. 2 Puzzles and strategy on the molecular-level study 3.3 Leap on molecular-level study──Opportunities

Catalytic Oxidation Of Methanol On Pt/C-Spe And Ptru/C-Spe Electodes, Aihua Su, Changzhi Li, Gongquan Sun, Ying Zhang, Tianhong Lu

Journal of Electrochemistry

Anode catalysts of methanol oxidation for direct methanol fuel cell, pt/C andPtRu/C,were prepared by chemical reduction in this work.The results indicated that the PtRu/Cshowed higher electrocatalytic activity than that of Pt/C. It was explained by XRD and XPS analysesthat the existence of Ru enhanced the catalytic activity for electrochemical oxidation of methanol.

Growth Kinetics And Breakdown Of Passive Films On Rebar Electrodes In Simulated Cement Pore Solution, Wei Chu, Yuanxiang Shi, Baoming Wei

Journal of Electrochemistry

The growth kinetics and breakdown of passive films on REBAR electrodes insimulated cement solution(pH=12.5 and 13.8)have been investigated using in situphotoelectrochemical methods and potential step method. The results show that there are two mainstages in the growth of the film ,with two rate functions characterized by linear relation between thefilm thickness and the direct logarithm of time. There is a sign in laser-scanning photoelectrochemicalmicroscopic image just before the passive film breaks down. The addition of inhibitor NaNO_2changesthe growth kinetics and thickness of the film ,and therefore improves the resistance of pitting corrosioninduced by chloride.

Application Of Electroanalytical Chemistry In Heteropoly Compounds System──Studies On The Redox Properties Of Bis( Undecatungstometalate)Lanthanates, Weiqing Wang, Xiumei Zhang

Journal of Electrochemistry

The redox properties of Ln(MW_(11))_2(M=As, Ti, Ga; Ln=La,ce,pr,Nd,Sm,Eu,Gd , Dy ) are systematically studied.It has been found that the redox order is La(AsW_(11))_2>La(TiW_(11))_2>La(GaW_(11))_2.The reduction process of Ln(MW_(11))_2 anion has been discussed.

Cyclic Voltammetric Calorimetry Studying The Deposition Of Copper Of Pt Electrodes, Yongchun Zhu, Robin H J Clark

Journal of Electrochemistry

In the present paper,cyclic voltammetric calorimetry has been used to study thedeposition of copper on platinum electrode from LiClO_4 aqueous solution. Cyclic voltammetricthermogram and cyclic voltammetric differential thermogram show that the deposition of copper on theelectrode is an exothermal process with a strong interaction between copper and platinum layer(-3227.0 kJ /mol).The electrochemical oxidation of the deposited copper is composed of twoprocesses :an endothermal activation process with 747.0 kJ/mol of activation enthalpy,and anexothermal oxidation reaction with-189.9 kJ/mol of the reaction enthalpy, which are accord withthe data from the theoritical estimation and thermodynamic handbook respectively.

Fabrication And Electrochemical Behaviors Of Thin Films Of Polyaniline By Langmuir-Blodgett Technique And Electropolymerization, Benzeng Hua, Zhaoxiong Xie, Yanzhen Chen

Journal of Electrochemistry

Hydrogen-bond between stearic acid and aniline in subphase lead to Langmuirmonotayers of stearic acid-aniline,the molecular area of stearic acid-aniline is 26 nm￣2.With surfacepressure increased into 50 mN/M,the hydrogen-bond would be rearranged ,aniline moleculartransales into vertical from horizontal,surface pressure decreased quickly. A new kind of Langmuirmonolayer is formed instead of collapse,it's molecular area decreases into 24 nm￣2 and thicknessincreases with 0.25 nm. After electroreduction of L-B films depeited onto the surface ofSnO_2 electrode ,anilne layers between two stear acid matix could be polymerized into thin films ofpolyanilne.The structu re of thin films has ben studied by small angle X-ray scattering.Theelectrochemical properties …

Simultaneous Detection System Combining Studies Of Programmedpotential Step Technique And Time-Resolved Ftir Spectroscopy, Shigang Sun, Xiaoyu Chen, Guoqiang Lu, Wenfeng Lin, Nanhai Li, Shenpei Chen, Hongping Dai, Jiqian Mu

Journal of Electrochemistry

No abstract provided.

Study Of The Modified Electrolytic Manganese Dioxide, Guohui Yuan, Dewei Chu, Rihui Shen, Hongwei Pan, Cuifen Zhang

Journal of Electrochemistry

A modified electrolytic manganese dioside doped with Bi(Bi-EMD)wasprepared and examined by XRD and XPS.It is predominantly γ-mnO_2 and the Bi exists as Bi_2O_3 inthe modified material.The content of Bi in Bi-EMDs increased with the increasement of Bi￣(3+)concentration in electrolyte,and reached14.3(wt)% from the bath of 0.008 mol·1￣(-1)Bi￣(3+)+ used.Some Zn /Bi-EMD prototype batteries of AA size were assembled,and which cycle life tests showedthat the Bi-EMD has better reversibility.

Studies Of In-Situ Raman Spectroscopy On Deprotonation And Degeneration Of Ppy Films, Jinsong Gao, Jing Chen, Yanzhen Chen, Qi Xue, Zhongqun Tian

Journal of Electrochemistry

By combining the in-situ Raman spectroscopic technique with the normalelectrochemical measurements ,the behavior and structure of PPY films in neutral or basic solutionswere studied.The oxidized PPY loses protons on the N atoms of pyrrole rings and is deprotonated inthese solutions ,resulting the formation of the quinoid structure. It makes the C=C stretching vibrationbonds of PPY split.Because this quinoid structure can′t be further oxidized ,the PPY becomes moredifficult to be oxidized and less reversible with the increasing of pH value of solutions and the degree ofdeprotonation of PPY. In the strong basic solution ( pH=13),the PPY film is degenerated in thepotential …

Effect Of Deposition Conditions On The Texture Of Zinc Deposits, Shukai Xu, Fangzu Yang, Shaomin Zhou

Journal of Electrochemistry

In this paper,the effects of additives,complex agents and current densities on thetexture and grain size of the zinc deposits from zincate baths are studied by means of X raydiffraction. The results show that the existence of additive AA-1 causes the preferential orientationof(101) face;when DIE is added alone,the preferential orientation changes to(110) face;withadditives both DIE and AA-1,Zn deposits with highly preferential orientation of(110) are obtainedin a certain range of current densities,and if complex agents TEA and EDTA are simultaneouslyexisted ,fine granular and bright Zn deposits with highly preferential orientation can be obtained in thewider range of current densities.

The Composition Structure And Corrosion Resistance Of Al-Mn Alloy Plating, Jiaju Guo

Journal of Electrochemistry

The Al-Mn alloy plating was electrodeposition from low temperature molten salts(below 200℃),its chemical composition control,corrosion resistance as well as the relationshipbetween chemical composition and structure were studied.The results indicate that the main effect onchemical composition of Al-Mn alloy plating is Mn ion concentration in molten salts.The Mn contentin the range of 25～40(wt)%, Al-Mn alloy plating has amorphous structure. In 0.5 mol/L H_2SO_4and NaCl solution ,corrosion resistance of the alloy plating is much better.When the alloy hasamorphous structure,corrosion resistance of plating has been remarkably increased.

Influence Of O-Phenylenediamine On The Catalysis At Hrp Enzyme Electrode In L,4-Dioxane, Hong Chen, Hui-Huang Wu

Journal of Electrochemistry

Horseradish peroxidase(HRP)was immobilized by crosslinkage on the glassycarbon electrode to prepare the enzyme electrede ,where the reduction of H_2O_2 was studied in l,4-dioxane media. It was shown that HRP electrode can catalyze the reduction of H_2O_2 without anymedintor,however, as an activator,o-phenylenediamine can promote the bio-catalysis. In thepresence of the activator,the parallel reactions occurred on the enzyme electrode. The workingcondition of the HRP electrede was investigated as the sensors for H_2O_2 and o-phenylenediamine,alsothe influence of water content in organic phase was discussed on the performance of the enzymeelectrode in organic phase.