Engineering Science and Materials Commons^™

Problems On The Study Of Anodic Films On Pb In Sulfuric Acid Solution (Ⅱ), Houtian Liu, Qunzhou Wang, Yongqin Wan, Weifang Zhou

Journal of Electrochemistry

The conditions for the growth of the different phases in the anodic Pb(Ⅱ) film on Pb in sulfuric acid solution were discussed.

A Study Of The Electroplated Fe-Cr-Ni Alloy Microstructure, Donglin Li, Jianping Liu, Fangzhou Guo, Jianrong Hua

Journal of Electrochemistry

The microstructure of the electroplated Fe-Cr-Ni alloys from the mixed carboxylic acid solution containing Cr(Ⅲ) and additives were determined with XRD and SEM. Experimental results showed that, under the experimental condition, the phase component, structure of Cu base electroplated Fe-Cr-Ni alloys had a critical thickness, which was 11 μm and a critical Ni content, which was 32%. Organic additives, formic acid or polyethylene Glycol, mainly affected the surface, cross section morphology of the electroplated Fe-Cr-Ni alloys. Adding Mo to the electroplated Fe-Cr-Ni alloys led to remarkable corrosion resistance in concentrated HCl.

The Applications Of Poap Ni2+ Films Modified Electrode As Sensor For Alcohol, Bingzeng Hua, Wenyun Hu, Yanzhen Chen

Journal of Electrochemistry

POAP Ni²⁺ films modified electrode can electrocatalyzes significantly the oxidation of alcohol. The modified electrode can be used as the electrochemical sensor for the detection of alcohol. But the oxidation of alcohol is effected by the thickness of films、the concentration of nickel ion in films, pH of electrolyte, as well as temperative. All of those conditions have been studied in order to achieve stable response current during the oxidation of alcohol, and the relation between concentration and current has been made. At last the major characteristic parameters, such as the low limitation of concentration, the response time, the ability …

Surface Raman Spectra Of Pyridine And 2 Mercaptopyrimidine Adsorbed On Rough Nickel Electrode, Qunjian Huang, Jinsong Gao, Xiongwei Cai, Bingwei Mao, Mingsen Zheng, Zhongqun Tian

Journal of Electrochemistry

The Raman spectra of pyridine and 2-mercaptopyrimidine (2-MP) adsorbed on bare nickel electrodes roughened by a HNO₃ etching procedure have been obtained for the first time by utilizing a highly sensitive confocal Raman microscope. Their adsorption behaviours are discussed briefly. This primary result illustrates a great potential for in-situ Raman spectroscopy in the study of chemical and electrochemical processes of transition metal surfaces.

Electrocatalytic Oxidation Of Some C2 Compounds (Alcohols, Aldehydes, And Carboxylic Acids) On A Pt/SbAd Electrod, Hong Li, Lincai Jiang, Xiong Jiang

Journal of Electrochemistry

The electrocatalytic oxidation behavior of some C₂ compounds(alcohols, aldehydes and carboxylic acids) on a Pt/Sb_ad electrode prepared in-situ or ex-situ UPD was investigated using pontential sweep and rotating disc electrode methods. It is confirmed that Pt/Sb_ad electrode show the most electrocatalytical active to the oxidation of aldehyde functional group and only a little activity to the oxidation of hydroxyl group, but no activity for the oxidation of carboxyl group.

The experimental results show that the activity of the Pt/Sb_ad electrode prepared by ex-situ UPD is higher than that prepared by in-situ UPD.

The limitations of the …

Studies Of Surface Treatment Methods And Their Operating Mechanisms For Activation Of Hydrogen Storage Electrode, Ronghui Hu, Hanxi Yang, Shigang Lu, Shengxian Li, Jingcheng Liu, Chongzhi Yang

Journal of Electrochemistry

Surface treatment methods by use of charge discharge cycling, KBH₄ reduction and KOH etching were parallely investigated for the rapid activation of Mn(NiCoMnAl)₅ electrode. It is found that the MH electrode treated with hot and concentrated KOH solution exhibits rapid and full activation, and also gives lower discharge overvoltage, higher stable capacity and improved cycleability. It is also revealed from SEM, EDAX and ICP analysis that the KOH activation of the electrode proceeds mainly through the enrichment of mischmetal and nickel in surface to form electrocatalytically active surface for hydrogen absorption reaction, but the surface modification with KBH …

Electrocatalytic Reduction Of Nitrite In The Presence Of Complex Of Cobalt(Ⅱ) And 1,10 Phenanthroline, Jian Tong, Xiaojun Dang, Hulin Li

Journal of Electrochemistry

The electrochemistry of cobalt(Ⅱ)-1,10-phenanthroline Co(Phen)₂²⁺ complex and its ability to electrocatalyze the reduction of nitrite were studied, we found that this complex could act as a catalyst in alkaline or neutral solution for nitrite reduction. We have investigated the effect of the complex composition on electrocatalytic ability. The effects of pH value, complex concentration, regeneration and activation of electrocatalyst on the catalytic current have been studied and discussed.

Study On Electrode Constructure And Electrical Performance Of Na/S Cell, Jianhua Yang, Jiadi Cao

Journal of Electrochemistry

A sodium wick for sodium electrode and trough shaped performs for sulfur electrode in Na/S cell were designed and investigated. The experiments suggested that the sodium wick for sodium electrode not only improved the discharge performance of cell but also reduced the quantity of sodium utilization, and increased the specific energy of Na/S cell. The trough shaped preform with alumina fibres for sulfur electrode decreased the polarization, improved the charge acceptance and prolonged the life of cell.

The Reduction Of Oxygen To Hydrogen Peroxide In An Acidic Trickle Bed Cell Using Graphite Chip Cathode, Zhaoe Lu, Guanyong Zhang, Tiangeng Zhong, Guonu Fang

Journal of Electrochemistry

The authors investigated the electrochemical reduction of oxygen to hydrogen peroxide in 0.05 mol/L H₂SO₄ solution by the trickle bed electrode using graphite chip. The bed dimension was 14×5×0.6 cm. The current efficiency and the concentration of H₂O₂ in the catholyte were determined at various current strengths and various rates of adding the electrolyte. The proper current was 0.15 A. i.e. the current density was 2.1 mA/cm² vertical cross section area of the bed. The concentration of H₂O₂ reached 7×10^-3 mol/L with the current efficiency of 0.2. If the …

Waste Steel Chips From Workshops As A Substitute For Fiber Reinforcement In Concrete, Alaa Abdultawab Abulella

Archived Theses and Dissertations

No abstract provided.

An Approach For Multidisciplinary Design Optimization, Robert V. Krueger

Mechanical & Aerospace Engineering Theses & Dissertations

Multidisciplinary Design Optimization (MDO) is an optimization technique that allows complex designs to be improved by managing conflicting goals in such a fashion so as to improve the overall design. This thesis presents a nonhierarchic MDO formulation and gives a general explanation of how it is to be applied to various appropriate problems. In addition, this thesis evaluates the viability of this MDO technique by applying it to two distinct, multidisciplinary problems that have been used as examples in other literature. The first example problem is a combined aerodynamic/structural problem and the second example is an alkylation process problem. First, …

Modeling Of Progressive Damage In Fiber-Reinforced Ceramic Matrix Composites, James P. Solti

Theses and Dissertations

An analytic methodology is developed to model the response of fiber-reinforced ceramic matrix composites (CMOs) when subjected to monotonic and fatigue loadings. The analysis requires the formulation of (1) a micromechanics model which defines the laminate's geometry and constitutive relationship; (2) failure criteria which estimate the extent of microstructural damage, and, finally, (3) a means of analyzing frictional slip, fiber pull-out, interfacial wear and laminate failure. For the present study, the behavior of unidirectional and crossply CMOs is investigated using modified shear-lag theory in conjunction with a set of failure criteria with a minimum reliance on empirical data. The damage …

Ftis Observation Of Twin Adsorbates Of Co On Rh Electrode In Acid Solution, Wenfeng Lin, Shigang Sun

Journal of Electrochemistry

Because of its great importance both in electrocatalysis and C1 chemistry applications, the adsorption of CO on metallic electrodes such as Pt, Pd, Au, Ag, RhF, etc. has been extensively studied by in situ infrared spectroscopy Since 1981. In all these studies only three types of CO adsorbates, i. e., linear (2090～2000 cm^-1), bridgrd (2000～1900 cm^-1) or multi-bonded (1900～1800 cm^-1) species, were identified. A different absorbate, twin CO on rhodium (Rh(CO)₂), does exist on the solid/gas interface of highly dispersed Rh or Rhn clusters on supports, this species originating a doublet at …

Hydrogen Evolution Reaction On Nanocrystalline Co-Mo/Ni Composite-Coated Electrodes, Weizeng Yu, Jie Ma, Yiming Chu, Huizhe Zhu, Hongjie Wang, Shuncheng Liu

Journal of Electrochemistry

The electrochemical behaviours of the hydrogen evolution reaction (HER) at electrodes prepared by composite coating of nanocrytstalline Co-Mo alloy particles formed by ball milling on nickel base has been sludied by using sleady-state polarization and ac impedance techiu ques. The microstructure and the size of the nanocrystals of Co-Mo alloy and the morphology of the composite-coating surface of the electrodes are measured by XRD, TEM and SEM. Results show that the nanocrystalline Co-Mo alloys prepared by high energy ball milling has high electrocatalytic activity for HER. The electrocatalytic activity for the HER is enhanced and the energy of activation for …

Electrochemical Studies On Corroding Metallic Electrodes In Frequency Domain, Chunan Cao

Journal of Electrochemistry

The electrochemical studies on corroding metallic electrodes carried out in the State Key Laberatory for Corrosion and Protection are reviewed briefly: (1) General equations of faradaic admittance under potential-control condition were derived based on the stabillity conditions of steady processes. The faradaic admittance at mixed potential then was deduced based on these equations and the electrochemical impedance spectroscopy (EIS) at corrosion potentials in the solutions containing interface inhibitors was diseussed by application of the thecetical results obtained. (2) The spectral power density (SPD) curves for electrochemical noise (EN) during the initial stagu of pitting corrosion were observed for iron and …

An Indirect Electrochemical Oxidation Of Toluene─Catalytic Effects Of Ag(Ⅰ) On Mn(Ⅱ)/Mn(Ⅲ) Couple Transition At Pt Electrode, Zhonghua Wang, Yunan Qu, Xingguo Yan, Qngmin Hua, Guacai Chen, Zhongquan Wang

Journal of Electrochemistry

The Catalytic effects of Ag(Ⅰ) on toluene oxidation by Mn(Ⅲ) as well as the anodic generation of Mn(Ⅲ) were investigated. The rates of toluene oxidation were first order with respect to both Ag(Ⅰ) and Mn(Ⅲ). Ag(Ⅱ) formed on the surface of the platinum anode when Ag(Ⅰ) was present in the anolyte, which catalyic the Mn(Ⅱ) to Mn(Ⅲ) in solution.

Preparation Techique Of Foamed Nickel By Electrodeposition, Xihua He, Ronghui Hu, Hanxi Yang, Zhengzhong Zuo

Journal of Electrochemistry

This paper describes the preparation technique and operation conditions for manufacturing foamed nickel by chemilcal pretreament, electrodeposition and heat treatment. The foamed nickel made in this method showed high porosity, uniformity and considerable strength and tenacity,applicable for various secondary battery electrodes.

Research On Molten Carbnate Fuel Cell, Naichao Li, Baolian Yi, Lianying Kong, Enjun Zhang, Huaxin Lin, Tianxi Qu, Yingcai Cheng

Journal of Electrochemistry

Cold-roll-milling has been evaluated as a technique for preparing porous LiAlO₂ matrices for use as a molten carbonate fuel cell electrolyte matrix. This technique produces reliable electrolyte structures with the following characteristics and advantages: ease of handling, uniform thickness, using nontoxic inorganic solvents, controlled pore size distribution, and ability to be impregnated with the alkali carbonate without fracrure.

The Molren Carbnatod Fuel Cell (MCFC) was assembled from sintered Ni electrodes and LiAlO₂ electrolyte matrix, the electrode area is 28 cm², the effect of operating conditions on cell performance was tested, it was found that the cell …

Study On The Manufacture Of Pt/C Gas-Diffusion Electrodes, Yonglin Ma

Journal of Electrochemistry

The various methods of manufacturing gas-diffusion electrodes are reviewed and a new method of preparing the Pt/C electrocatalyst and the gas-diffusion electrodes is explored in this paper. The electrochemical performance of resulting electrodes in concentrated phosphoric acid for oxygen reduction at 150℃ are compared with the commercial electrode which purched from Giner Inc. (U. S. A). The results show that the performance of the Pt/C electrodes which manufactured by the method in this paper has been greatly improved. Therefor, a fuel cell using such electrodes has high industrial value.

The Inhibition Of Amphipathic S- And N-Containing Compounds On Carbon Steel Corrosion, Wei Xing, Yibin Shan, Du Guo, Tianhog Lu, Shiquan Xi

Journal of Electrochemistry

Ordered monolayers of S- and N-containing amphipathic corrosion inhibitors were depoitod onto the surfaces of carbon steel electrode with super-molecular assembly technique. The effect of molecular aggregation of monolayers on carbon steel corrosion in 0.05 mol·cm^-3 H₂SO₄ and the mechanisms of these inhibitors were discussed in details. It was found that the transport of hydrated hydrogen ion to the surface of steel depends strongly on the inhibitor molecular aggregation in the monolayers.

Development Of The High Capacity Sintered Type Nickel Positive Electrode, Guohua Yu, Shijie Zhang, Xiaolin Wang, Jingqi Wei

Journal of Electrochemistry

By improving the design and technologies of the sintered type nickel oxide positive electrode for the NiMH batteries, We do our best to increase the sinter volume and porosity,the amount of the active materals and their utilization, so we have fabricated the high capacity sintered typo nickel electrodes fitting for the NiMH battreies. The sfecitic capacity of the lot produced electrodes is up to 550 mA/cm^-3.

The Influence Of Cathode Ingredients In Zinc Chloride Type Battery On The Discharge Ability, Qi Shen, Biao Zhuang

Journal of Electrochemistry

The influence of cathodic powder ingredients in ZnCl₂ type heavy duty battery on the discharge ability has been studied, a suitable battery ingredients is founds.

Characterization Of Low Pressure Chemically Vapor Deposited Boron Nitride Films As Low Dielectric Constant Materials, Manish Narayan

Theses

Boron nitride thin films were synthesized on Si and quartz wafers by low pressure chemical vapor deposition using borane triethylamine complex and ammonia as precursors. The films were processed at 400°C, 475°C and 550°C at a constant pressure of 0.5 Torr and at different precursor flow ratios.

The films deposited were uniform, amorphous and the composition of the films varied with deposition temperature and precursor flow ratios. The thickness of the film increased with increasing flow ratio, but, decreased with increasing temperature. The stresses in the film were either mildly tensile or compressive.

The least dielectric constant for the films …

Triangulation Rangefinder For Archers, Jeffrey Hargrove, William G. Wickham, John E. Briggs

Mechanical Engineering Patents

An archery rangefinder for use from an elevated position comprises a power supply for an electronic digital panel meter and a power supply for two voltage divider circuits that comprise the rangefinding circuit. One voltage divider provides a voltage signal proportional to the elevation distance. This signal acts to supply the second voltage divider to attenuate the voltage further by a factor proportional to the tangent of the inclination angle. A weighted pendulum arm is attached to a potentiometric element in the second voltage divider to effect feedback relevant to the angle of inclination. All circuits and components are housed …

Incorporating Matlab's Signal Processing Toolbox Into A Dsp Course At An Undergraduate E.E. Program, Sol Neeman Ph.D.

Engineering Studies Faculty Publications and Creative Works

This paper provides some suggestions for incorporating MATLAB's Signal Processing Toolbox into a DSP course. Often, in a DSP course, students have difficulties understanding abstract and non-intuitive concepts and seeing their relevance to the practical part of their curriculum. The tools offered by MATLAB's Signal Processing Toolbox, can help to make these concepts more tangible and provide a perspective for students. Some basic tools relevant to an undergraduate DSP course will be introduced, including examples of tool use and graphic results. The tools presented will be applied in the areas of synthesis and analysis of signals, FFT computation, impulse response …

Monitoring The Dynamics Of Scaled Vehicles Using A Sonic Digitizer, Michael J. Bader, Larry G. Wells, Linus R. Walton

Biosystems and Agricultural Engineering Faculty Publications

Certain dynamic stability characteristics of an alternate method of mounting a front-end loader to a farm tractor were compared to those of a conventionally mounted front-end loader operating on a specified terrain. One objective of the study was to determine if the alternate method of mounting a front-end loader resulted in better stability characteristics and, in turn, safer operation than a conventional front-end loader. Another objective was to determine if a three-dimensional sonic digitizer could monitor the motion of the scale model tractor-loader systems accurately enough to perform a comparison between the systems. This article describes the second objective of …

Growth And Properties Of Chemically Deposited Cds Thin Films, Edward A. Gluszak

Theses : Honours

Polycrystalline thin films of undoped CdS and In doped CdS (i.e. CdS:In) have been deposited by chemical bath on glass slides and high purity silicon wafers. The effect of different processing conditions (e.g. substrate temperature, doping and air annealing) on film growth, optical transmittance and electrical properties were correlated with the film microstrucutre. The mechanism of chemical bath deposition of CdS thin films from the ammonia-thiourea system is studied. The influence of reaction parameters (i.e. concentration of reactants and pH) on film growth were determined and modeled. Thin film growth is thermally activated with an energy ≈ 5 x 10 …

Thermal Behavior Of Energy Storage System In A Cylindrical Tank, Walid Wagih Darwish

Archived Theses and Dissertations

No abstract provided.

Investigation Of Residual Strength And Fatigue Life Of Unstiffened Aluminum Panels With Multiple Site Damage, Mark C. Cherry

Theses and Dissertations

Multiple Site Damage MSD is the occurrence of small fatigue cracks at several sites within aircraft structures. This is important since it may lower the residual strength and fatigue life of the structure beyond what can be predicted using the damage tolerance technique based on a single crack, currently in use to design aircraft structures. This study investigated the effects of MSD on unstiffined panels. MSD usually occurs at rivet holes, or other stress concentration locations within an aircraft structure. This study simulated rivet holes with MSD, by using holes of constant diameter with small cracks, evenly spaced across the …

Thermo-Mechanical Fatigue Behavior Of Cross-Ply Ceramic Matrix Composite Under Tension-Tension Loading, Dana G. Allen

Theses and Dissertations

The purpose of this study was to investigate the combined effect of cyclic temperature and loading on the fatigue life of a ceramic matrix composite with a cross ply lay-up. The material used in this study was a potassium borosilicate glass (BSG) doped magnesium aluminosilicate (MAS) cordierite matrix reinforced with Nicalon (silicon carbide, SiC) fibers in a [0/90]_4s lay-up. Thermomechanical fatigue (TMF) tests were performed with a period of 180 seconds/cycle, or 0.00556 Hz, and a triangular wave-form. The temperature was cycled between 566°C and l093°C, and the stress levels varied between 60 MPa and 145 MPa. All tests …