Engineering Commons^™

Effect Of High Concentration Lithium Bromide Solution On Electrochemical Behavior Of Low Alloy Steel At High Temperature, Jian-Wei Guo, Cheng-Hao Liang

Journal of Electrochemistry

By electrochemical measurements and weight loss experiments, the effect of MoO₄^2- on low alloy steel's electrochemical behaviors was investigated at high temperature in 55%LiBr+0.07 mol/L LiOH solution. The results showed that MoO₄^2-, as an anodic inhibitor, formed passive film rapidly and impeded both anodic and cathodic procedures. Moreover, Na₂MoO₄ prevented corrosion effectively in 55%LiBr+0.07 mol/L LiOH solution when its concentration is more than 200 mg/L. The pitting potential increased accompanying to the arising of Na₂MoO₄ concentration. Some elements of alloy strengthened resistance to corrosion, shch as chromium and nickel, …

The Development Of Carbon Monoxide Tolerant Catalysts For Proton-Exchange Membrane Fuel Cell, Zhong-Jun Hou, Hong-Mei Yu, Bao-Lian Yi, Ming Han

Journal of Electrochemistry

High over-potential of proton exchange membrane fuel cell (PEMFC) anode caused by carbon monnoxide poisoning when reformate or methanol is used as fuel is main obstacle to the high performance of PEMFCs. Using carbon monoxide tolerant catalysts is the most hopeful way to solve the CO problem. The CO poisoning problem is reviewed briefly in this paper, and the development of CO tolerant catalysts is introduced in details, including electrocatalysts activity, preparation method and mechanism of tolerance to CO.Mo and W can improve catalysts' CO tolerance. Multi-component catalysts are expected to be more tolerant to CO.

Studies Of Adsorption And Oxidation Of Ethanol On Nm-Pt/Gc Electrode——I. Cyclic Voltammograms And In-Situ Ftir Spectroscopy In Alkaline Media, Guo-Lian Chen, Shi-Gang Sun, Sheng-Pei Chen, Zhi-You Zhou

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L^-1 NaOH+0.1 mol·L^-1 CH₃CH₂OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH₃COO^-, only very small amount of CH ³CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

Investigation Of A Complex Lithium Cobalt Nickel Oxide As Lithium Ion Battery Cathode Materials Prepared By A New Citrate Sol-Gel Method, Jing-Li Han, Qing-Guo Liu

Journal of Electrochemistry

The synthesis and electrochemical characteristics of lithium cobalt nickel oxide as cathode materials for rechargeable lithium batteries were investigated. It was clarified from these investigations that lithium cobalt nickel oxide has been produced from basic cobalt carbonate,basic nickel carbonate, lithium carbonate, and citrate. LiNi_0.8Co _0.2O₂ prepared under the stream of oxygen gas showed a higher cycling capacity of (～190 mAh·g^-1).

Template Synthesis Of Nano-Structured Electrode Materials And Its Electrochemical Performance, Jian Zhao, Quan-Yong Gao, Yong Yang, Zu-Geng Lin

Journal of Electrochemistry

In this letter, various nano structured materials such as spinel LiMn₂O₄ nanotubes/nanowires and carbon nanotubes have been prepared by using porous alumina template. The prepared template and materials have been characterized by AFM and TEM techniques. It is shown that size of the nanotubes can be conveniently controlled by using template method. Some preliminary results of cyclic voltammetry about nano structured LiMn₂O₄ are also reported.

The Electrochemical Performance Of The Spinel Limn2O4, Shi-Gang Lu, Yu-Cheng Sun, Ren-Min Liu, Wei-Hua Jin, Wen-Zhong Li, Cang Han

Journal of Electrochemistry

The cathode material spinel LiMn₂O₄ of lithium ion battery was synthesized by making use of solid state reaction at 750～850 ℃. The discharge capacity was 115～125 mAh·g^-1 . It was observed that the capacity loss increase at the elvated 55 ℃ temperature. A little excess Li content and the Co doped spined could improved the cycle capability of the cathode material. The dissolution of the spined in the electrolyte was measured. The treatment method was used to stabilize the LiMn₂O₄ structure. It was found that the spinel LiMn₂O₄, treated …

The Study Of Pretreatment For The Determination Of The Conventional Anion In Sea Water By Ic——The Method Of Electrolysing Argentine Electrode, Lei Guo, Wei Yang, Rong-Zong Hu

Journal of Electrochemistry

The method of pretreatment to determine trace amounts of Br^-, NO₃^- and SO₄^2- in sea water by ion chromatography was proposed, by which the electrolysing argentine electrode was used to minimize the disturbance of Cl^-. The results indicate that the method is simple, convenient, quick and efficient with recovery rates over 95 percent.

Studies Of Electrochemical Impedance Spectroscopy On Coated Steel With Artificial Defect, Zhi-Gang Zhang, Zhi-Jun Gu, Yong-Gui Liao, Qi-Long Guo, Fang-Teng Su, Yan-Zhen Chen

Journal of Electrochemistry

Electrochemical Impedance Spectroscopy (EIS) was applied to rapidly evaluate the performance of organic coatings and the characterization of the protective properties of anticorrosive pigments in the presence of artificial defect in organic coatings. The results showed that artificial defect method can rapidly evaluate the performance of coatings and discriminate whether the pigments in the coatings have inhibitive.

The Memory Effect Of Mh-Ni Battery, De-Ming Xie, Jian-Ming Wang, Jian-Qing Zhang, Chu-Nan Cao

Journal of Electrochemistry

The memory effect of MH-Ni battery was investigated. The depth of discharge, discharge rate and cycle number influence the memory effect greatly. A few completely full charge/discharge cycles could eliminate it. The existence of the memory effect had nothing to do with zinc element. During the course of life cycling at low DOD (degree of discharge), the smaller the discharge current was, the lower was the maximum charge voltage. In addition, discharge voltage and discharge capacity drop fast at the beginning, gradually leveled off at about a value. If the discharge current was increased, the discharge capacity was obviously less …

Electrochemical Polymerization Of Biphenyl And P-Terphenyl In Organic Solvent, Sheng-Yun Cui

Journal of Electrochemistry

The electro-oxidation of ethanol on nm-Pt/GC electrode in alkaline solutions containing 0.02 mol·L^-1 NaOH+0.1 mol·L^-1 CH₃CH₂OH was investigated by using cyclic voltammetry and in-situ FTIR spectroscopy. The experimental results demonstrated that the main product of ethanol oxidation is CH₃COO^-, only very small amount of CH ³CHO has been determined simultaneously. In contrast with the dual path reaction mechanism for the oxidation of ethanol in acid media, the oxidation of ethanol in alkaline media didn't pass through the dissociative adsorption, and no adsorbed species could be determined even using a …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 3, November 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Detection Of Solid Pigment In Dermatoscopy Images Using Texture Analysis, Murali Anantha, William V. Stoecker, Randy Hays Moss

Chemistry Faculty Research & Creative Works

Background/aims: Epiluminescence microscopy (ELM), also known as dermoscopy or dermatoscopy, is a non-invasive, in vivo technique, that permits visualization of features of pigmented melanocytic neoplasms that are not discernable by examination with the naked eye. ELM offers a completely new range of visual features. One such feature is the solid pigment, also called the blotchy pigment or dark structureless area. Our goal was to automatically detect this feature and determine whether its presence is useful in distinguishing benign from malignant pigmented lesions.

Methods: Here, a texture-based algorithm is developed for the detection of solid pigment. The factors d and a …

Simulation Of Daily And Monthly Stream Discharge From Small Watersheds Using The Swat Model, Crystal A. Spruill, Stephen R. Workman, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

The Soil and Water Assessment Tool (SWAT) was evaluated and parameter sensitivities were determined while modeling daily streamflows in a small central Kentucky watershed over a two-year period. Streamflow data from 1996 were used to calibrate the model and streamflow data from 1995 were used for evaluation. The model adequately predicted the trends in daily streamflow during this period although Nash-Sutcliffe R² values were –0.04 and 0.19 for 1995 and 1996, respectively. The model poorly predicted the timing of some peak flow values and recession rates during the last half of 1995. Excluding daily peak flow values from August …

Alternative Principal Components Regression Procedures For Dendrohydrologic Reconstructions, Hugo G. Hidalgo, Thomas C. Piechota, John A. Dracup

Civil and Environmental Engineering and Construction Faculty Research

Streamflow reconstruction using tree ring information (dendrohydrology) has traditionally used principal components analysis (PCA) and stepwise regression to form a transfer function. However, PCA has several procedural choices that may result in very different reconstructions. This study assesses the different procedures in PCA-based regression and suggests alternative procedures for selection of variables and principal components. Cross-validation statistics are presented as an alternative for independently testing and identifying the optimal model. The objective is to use these statistics as a measure of the model's performance to find a conceptually acceptable model with a low prediction error and the fewest number of …

Application Of Tree-Structured Regression For Regional Precipitation Prediction Using General Circulation Model Output, Xiangshang Li, David J. Sailor

Mechanical and Materials Engineering Faculty Publications and Presentations

This study presents a tree-structured regression (TSR) method to relate daily precipitation with a variety of free-atmosphere variables. Historical data were used to identify distinct weather patterns associated with differing types of precipitation events. Models were developed using 67% of the data for training and the remaining data for model validation. Seasonal models were built for each of 2 US sites: San Francisco, California, and San Antonio, Texas. The average correlation between observed and simulated daily precipitation data series is 0.75 for the training set and 0.68 for the validation set. Relative humidity was found to be the dominant variable …

Use Of Goes Thermal Infrared Imagery For Eruption Scale Measurements, Soufrière Hills, Montserrat, William I. Rose, Gari C. Mayberry

Department of Geological and Mining Engineering and Sciences Publications

GOES two-band IR data are used to estimate the magnitude of small eruption clouds (ash; <∼10⁵ tonnes of fine [1–25 µm in diameter] ash, and 5–15 km asl). The method is demonstrated on clouds from Soufrière Hills Volcano, Montserrat in 1997–99. The clouds in early 1999 were much smaller, were generally emplaced lower in the atmosphere and contained an order of magnitude less fine ash than 1997 clouds generated during the most intense phase of the eruption to date. Although GOES has an excellent capability for large eruption clouds, its use for smaller eruptions like Montserrat highlights several shortcomings, including …

Santa Clara Magazine, Volume 42 Number 2, Fall 2000, Santa Clara University

Santa Clara Magazine

10 - I WANT MY IPO! By Susan Vogel. With so much venture capital available out there, why do women have to sprint to catch up with men in the race for funding?

14 - ON THE THRESHOLD OF A NEW ERA By George F. Giacomini, Jr. A long-time SCU professor offers his opinion of the most pivotal moments in the University's 150-year history, from wars to the admission of women.

18 - OF HEADHUNTERS AND SOLDIERS By Renato Rosaldo. Living with a headhunting Filipino tribe taught this author to be open to the possibility that other cultures have valid, …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 2, October 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Fourier Transform Raman Spectroscopy For Process Control In The Petroleum Industry, Kent Lawson Wise

Chemistry & Biochemistry Theses & Dissertations

As early as 1950, Raman spectroscopy was proposed as a method to determine aromatics and olefins in hydrocarbon mixtures. Until recently, extensive use of Raman spectroscopy in the characterization of hydrocarbons has not been practical due to several limitations. One early limitation to Raman analysis was the absence of a high intensity and stable excitation source. This problem has been overcome with the advent of lasers. Another limitation was the presence of fluorescence in hydrocarbon fuels when excited by visible lasers. However, the development of Fourier-transform Raman spectrometers now allows Raman spectra to be collected using near-IR lasers (e.g …

Studies Related To The Design And Implementation Of A Magnetic Suspension And Balance System, Syed Adeel Akhtar Jafri

Electrical & Computer Engineering Theses & Dissertations

This thesis presents studies related to the magnetic suspension and balance system (MSBS) of the Princeton/ONR High Reynolds Number Testing Facility (HRTF). The main motivation for developing the MSBS is to provide interference free aero/hydrodynamic testing of submersible models, which will lead to more accurate measurements. From the controls point of view, the main specification of the MSBS is to robustly control the position of a submersible model in five degrees of freedom (DOF), including three translational as well as pitching and yawing positions. The MSBS should not only regulate the submersible model's position but should also allow for small …

Fabrication And Characterization Of Silicon Field Emitter Arrays, Aaron M. Brock

Electrical & Computer Engineering Theses & Dissertations

Field emission is a process through which the application of a large electric field to the surface of a material causes electron emission into vacuum. The electron emission current is a strong function of the geometry of the emitting material. The focus of this thesis is to investigate the effect of geometry on the emission current. Specifically, silicon field emitter arrays were fabricated using two separate fabrication processes termed the standard process and the new process. The uniformity of the arrays was measured experimentally. The arrays were used in field emission tests from which parameters controlling field emission were extracted. …

Review Of: Joe Thornton, Pandora's Poison: Chlorine, Health, And A New Environmental Strategy, William Ronnenberg Jr.

RISK: Health, Safety & Environment (1990-2002)

Review of the book Pandora's Poison: Chlorine, Health, and a New Environmental Strategy by Joe Thornton, (M.I.T. Press 2000). Appendices, notes, references, index. LC 99-057011; ISBN 0-262-20124-0 [599 pp. $34.95 cloth, Five Cambridge Center, Cambridge MA 02142-1493] .

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 1, September 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A fourteen page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

The Effect Of Cerium On The Anodic Behavior Of Pb-Ca-Sn Alloy In Sulfuric Acid Solution, Hou-Tian Liu, Jiong Yang, Hai-He Liang, Ji-Hua Zhuang, Wei-Fang Zhou

Journal of Electrochemistry

The cyclic voltammograms for Pb - 0.5 at% Ca - 1.5 at% Sn and Pb - 0.5 at% Ca - 1.5 at% Sn containing a certain amount of cerium in 4.5 mol·dm^-3 H₂SO₄ at 20℃ were measured between 0.6 V and 1.4 V(vs. Hg/Hg₂SO₄). The growth rate of the anodic Pb(Ⅱ) films formed on the mentioned alloy electrodes at 0.9 V in the same sulfuric acid medium was investigated using the Linear Sweep Voltammetry. The variation with electrode potential of the real part of the impedence (Z’) for the anodic Pb(Ⅱ) films …

The Lineal Polarization Method For Corrosion Rate Measurement Of Reinforcing Bar Of Concrete In Situ, Ai-Ling Du, Wen-Tao Hou, He-Ming Zhang, Jian-Qun Luo

Journal of Electrochemistry

A linear polarization method was applied to measure corrosion rate of reinforcing bar of concrete in situ. Generally in the experiment, the area and shape of the reinforcing bar as a working electrode can be changed and adjusted according to our needs. But polarization area cannot be defined when reinforcing bar is polarized in situ, so that a real R_p can't be obtained. Thus the purpose of present work is to improve the measurement system. We used the double-ring auxiliary electrodes made by ourselves. The size of the double-ring auxiliary electrodes was adjusted repeatedly until the real polarization area …

The Electro-Catalytic Oxidation Of Hcooh On Electrodeposited Pd Electrode, Quan Zhou, Cun-Zhong Zhang, Xiao-Lin Lu, Zhong-Da Wu

Journal of Electrochemistry

The coherent electroplates were prepared by electro depositing Pd on supporting materials glassy carbon. The surface morphology of the electrodes was examined by SEM. The electro oxidation of HCOOH in HClO₄ solution was investigated by using cyclic voltammetry. The results show that the deposited conditions in the preparation of electrodes by electro depositing Pd affect the electrodes electro catalytic activity to the oxidation of HCOOH. The platinized Pd electrode on GC substrates using large current density is of higher catalytic activity to the oxidation of HCOOH than Pd electrode. The electro catalytic activity of PdO formed on the Pd …

Electrochemical Characteristics Of Sb Irreversibly Adsorbed On Pt(100), Pt(110), Pt(111) And Pt(320) Electrodes, Yi-Yun Yang, Zhi-You Zhou, Qi-Hui Wu, Shi-Gang Sun

Journal of Electrochemistry

The electrochemical behaviors of irreversibly adsorbed antimony on Pt(100), Pt(110), Pt(111) and Pt(320) were studied by using cyclic voltammetry. The results revealeds that the Sb adatoms are stable on Pt(100), Pt(110), Pt(111) and on Pt(320) when electrode potentials are below 0.45 V(SCE) and 0.40 V, respectively. It was demonstrated that various coverages of Sb ad can be conveniently obtained by controlling the number of potential cycling and varying the upper limit of potential scan. The electrochemical behaviors of irreversibly adsorbed antimony varied with the surface atomic arrangement of Pt single crystal electrodes. Based on quantitative results of the relationship between …

A Study On Stochastic Resonance For The Process Of Active-Passive Transition Of Iron In Sulfuric Acid, Hong-Bo Ding, Bao-Yun Xia, Chun-Sheng Yin, Zhong-Xiao Pan, Renato Seeber

Journal of Electrochemistry

The bistable characteristics of the process of active passive transition of iron in sulfuric acid was described and the stochastic resonance phenomenon in the process was simulated.

Mechanisimic Study Of Fes Electrode Process, Cong-Sheng Guan, Shu-Zhen Duan

Journal of Electrochemistry

The mechanism of FeS electrode process has been investigated by using linear cyclic voltammetry. The electrode porcess of FeS is accompanied with the formation and dissolution of insoluble FeS and controlled by ohmic resistance. The peak currents and potentials on the cyclic voltammograms are dependent lineally on the square root of the scan rates. According to this, an ohmic resistance controlling model of FeS electrode has been put forward, and the relative functions between peak currents or potentials and scan rates have been deduced. The theoretical deduction is corresponding to the results of the experiments.

Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang

Journal of Electrochemistry

By investigating the polarization curves of pure Ni-P alloy, Ni-P alloy coation and carbon steel in nitric acids with different concentrations, the sutable concentration of nitric acid for the evaluation of the porosity of Ni-P alloy coatings has been determined and the coatings with different thickness have been evaluated. The results indicated that the nitric acid with 10 wt% concentration is the most suitable solution for the porosity of the coating by using electrochemical method. The polarization curve of Ni-P alloy coating in 10% nitric acid can accurately reveal the porosity. With the decrease of the porosity of the coating, …