Engineering Commons^™

Investigation On Ru-Ti-Ir-Sn Oxide Anode Coatings For Electrolyzing Seawater, Ke Wang, Yan Han, Lei-Yuan Wang, Xiao-Ling Zhang, Yu-Pu Sun

Journal of Electrochemistry

The anode coatings of Ru-Ti-Ir-Sn oxide with various compositions were prepared by thermal decomposition. The physical and electrochemical properties of the coatings were characterized by scanning electron microscope (SEM), energy dispersive X-ray detector (EDX), accelerated life, current efficiency, anti-Mn²⁺ contamination, polarization curveandcyclic voltammetry tests. The results showed thatthe anode coating with optimized formula possessed excellent overall properties for electrolyzing seawater.

Structure And Corrosion Electrochemical Properties Of Self-Assembled (3-Mercaptopropyl) Trimethoxysilane Films On Copper Electrode, Ling Huang, Ke-Fa Lin, Fang-Zu Yang, Shu-Kai Xu, Shao-Min Zhou

Journal of Electrochemistry

A self-assembled monolayer of (3-mercaptopropyl) trimethoxysilane(MPTS) was formed on a electrochemical polished copper surface electrode. The corrosion protection abilities of the monolayer were evaluated in 5% NaCl solution using electrochemical linear polarization. The effects of deposition time and silane concentration on corrosion of copper were also discussed. The surface structure of MPTS films was measured by FT-IR and SEM. It was found that the corrosion resistance of copper was reduced markedly owing to the MPTS monolayers formation on copper. The MPTS monolayer retarded the reduction of dissolved oxygen and inhibited the growth of copper oxide in the NaCl solution. FT-IR …

Study On Synthesis Of M-Phenoxy Benzoic Acid By Electrolysis Oxidation Method, Wei Xu, Chong-Tao Zhao

Journal of Electrochemistry

The m-phenoxy benzoic acid was synthesized by oxidation m-phenoxy toluene using Cr(Ⅵ)as oxidation media, which was prepared by electrolysis oxidation of Cr(Ⅲ)in the electrochemical bath using Nafion 417 as a diaphragm, Pb-PbO₂ as an anode and Pb as cathode. The effect factors on the electrochemical oxidation of Cr(Ⅲ)to Cr(Ⅵ)in this electrolysis were studied. Furthermore, the optimal conditions for electronic synthesis of m-phenoxy benzoic acid were also discussed.

The Effect Of Oxidant On Structure And Properties Of Pan/Ptfe Conducting Composite Membrane, Chang-Yuan Tao, Jing Chen, Jun Du, Cai-Xin Sun

Journal of Electrochemistry

The PAn/PTFE conducting composite membrane was prepared by means of in-situ permeating chemical polymerization, with (NH₄)₂S₂O₈ and Na₃VO₄ being used as an oxidant respectively. The polymerization-growth behavior of the aniline by using different oxidant was compared. In addition, the oxidant effect on the structure and properties of conducting composite membrane was discussed. The results of SEM micrographs, pore size distribution and electrochemical methods suggested that using either oxidants could also induce the product with small pore size and dense pore structure. Compared with (NH₄)₂S₂O …

Static And Modal Analysis Of The Magnetic Levitation Vehicle, Santosh Kumar Desetty

Mechanical & Aerospace Engineering Theses & Dissertations

The magnetic levitation train project at Old Dominion University has been stalled due to many technical problems. The control system is the main component of the vehicle, which is supposed to maintain an intended gap of 1 cm between the vehicle and the track while traveling, hence providing a smooth ride. The goal of the project is to document the mathematics of the complete system so that the control algorithm can be implemented and modified with the expectation of obtaining an improved levitation and propulsion.

The complete system includes the vehicle, the track, and the concrete guide-way. The focus of …

Tensile Properties Of Martensitic Stainless Steels At Elevated Temperatures, Ajit K. Roy, Srinivasarao R. Kukatla, Bhagath Yarlagadda, V. N. Potluri, Martin Lewis, Brendan O'Toole

Mechanical Engineering Faculty Research

Tensile properties of quenched and tempered martensitic alloys EP-823, HT-9, and 422 were evaluated at temperatures ranging from ambient to 600 °C as a function of three different tempering times. The results indicated that the yield strength, ultimate tensile strength, and the failure strength were gradually reduced with increasing temperature. The ductility parameters were enhanced at elevated temperatures due to increased plastic flow. However, the tempering time did not significantly influence these properties. The evaluation of the fracture surfaces by scanning electron microscopy revealed reduced cracking and dimpled microstructures, indicating enhanced ductility at higher testing temperatures.

Residual Stress Characterization In Structural Materials By Destructive And Nondestructive Techniques, Ajit K. Roy, Anand Venkatesh, Vikram Marthandam, Satish Dronavalli, Douglas P. Wells, Ronald Rogge

Mechanical Engineering Faculty Research

Transmutation of nuclear waste is currently being considered to transform long-lived isotopes to species with relatively short half-lives and reduced radioactivity through capture and decay of minor actinides and fission products. This process is intended for geologic disposal of spent nuclear fuels for shorter durations in the proposed Yucca Mountain repository. The molten lead-bismuth-eutectic will be used as a target and coolant during transmutation, which will be contained in a subsystem vessel made from materials such as austenitic (304L) and martensitic (EP-823 and HT-9) stainless steels. The structural materials used in this vessel will be subjected to welding operations and …

Steady State Stress In A Coated Infinite Half-Space Subjected To A Moving Load, Jason M. Cruthirds

Theses and Dissertations

This research investigates the use of coatings to mitigate the stress distribution into an infinite half-space. High energy impact phenomenon at velocities exceeding the speed of sound is an important area of interest to the Air Force Research Laboratory. Holloman Air Force Base's High Speed Test Track sustains significant damage due to this phenomenon. In this thesis, the track system and coating are modeled analytically with equations of motion in terms of linear displacements. Coating thickness and material properties of epoxy or polymer laminates are investigated to understand their affect of stress distribution in the rail. An analytic solution is …

Analysis Of Computational Methods For The Treatment Of Material Interfaces, Minh C. Nguyen

Theses and Dissertations

Rocket sled tests at the Air Force Research Laboratory's Holloman High Speed Test Track frequently approach velocities where gouging development becomes the limiting factor to achieving higher operating velocities. Direct observation of the gouging process is not possible so computational modeling is necessary to study the phenomenon. Since gouging development is dependent on the impact surface conditions, the method used to model material interfaces directly affects the accuracy of the solution. Three methods are available in the hydrocode CTH to handle material interfaces: 1) materials are joined at the interface, 2) a frictionless slide line is inserted, and 3) a …

Fatigue Behavior Of A Functionally-Graded Titanium Matrix Composite, Scott R. Cunningham

Theses and Dissertations

Functionally-graded Titanium Matrix Composites are an attempt to utilize the high-strength properties of a titanium matrix composite with a monolithic alloy having the more practical machining qualities. This work studied the mechanical characteristics of the joint region as a first step toward future evaluation of this material. The scope of this effort involved testing under monotonic tension and fatigue loading conditions. Mechanical properties and cyclic behavior were evaluated for the joint area and then compared to those of the parent materials. The results of this study found that the strength of the transition region was slightly higher than the unreinforced …

Creep-Rupture Behavior Of An Oxide/Oxide Ceramic Matrix Composite At Elevated Temperatures In Air And Steam Environments, Lee B. Harlen

Theses and Dissertations

Oxide/oxide ceramic matrix composites (CMCs) are being considered for applications such as jet engine combustion chambers and afterburner flaps. Nextel™ 720/A (N720/A), an oxide/oxide CMC with an alumina matrix and no interphase at the fiber-matrix interface, was developed specifically to provide improved long-term properties and performance at 1200°C. This study focused on experimental investigation of creep behavior of N720/A [0/90] at elevated temperatures in laboratory air and in 100% steam environment. Monotonic tensile tests to failure were performed at 23, 1200, and 1330°C. Ultimate tensile strength (UTS) values were established and monotonic stress-strain curves were produced. Creep-rupture tests at 1200°C …

Tensile Stress Rupture Behavior Of A Woven Ceramic Matrix Composite In Humid Environments At Intermediate Temperature, Kevin J. Larochelle

Theses and Dissertations

Stress rupture tests on the Sylramic^TM fiber with an in-situ layer of boron nitride, boron nitride interphase, and SiC matrix ceramic matrix composite were performed at 550°C and 750°C with 0.0, 0.2, or 0.6 atm partial pressure of water vapor, pH₂O. The 550°C, 100-hr strengths were 75%, 65% and 51% of the monotonic room temperature tensile strength, respectively. At 750°C, the strengths were 67%, 51%, and 49%, respectively. Field Emission Scanning Electron Microscopy analysis estimated the total embrittlement times for 550°C with 0.0, 0.2, and 0.6 atm pH₂O were >63 hrs, >38 hrs, and between …

An Investigation Of A Simplified Gouging Model, Gregory S. Rickerd

Theses and Dissertations

Gouging is a type of structural failure that becomes important when two metals slide against each other at velocities in the range of 1.5 kilometers per second. A computer model has previously been used to model the development of gouging at the Holloman High Speed Test Track. This model has not been experimentally verified to be correct, due to the complexity of the model. This research develops a simplified model that can be experimentally verified. The computer program utilized in this research was studied to determine the most appropriate options to use in simulations. This was accomplished by modeling a …

Fabrication And Studies Of A Novel Ag/Agcl Reference Electrode In High Temperature Molten Chloride Salts, Pei Gao, Xian-Bo Jin, Di-Hua Wang, Xiao-Hong Hu, Zheng Chen

Journal of Electrochemistry

A new method for the easy fabrication of a stable and long life silver/silver chloride reference electrode in molten chloride salts is described in this paper. The method is based on the fact that simply placing the silica glass in molten NaCl or its vapour in the presence of oxygen resulted in satisfactory conductivity for sodium ion and possibly calcium ion in the material.The performance of such made electrode has been investigated in a few typical chloride systems at temperatures ranging from 400 to 900℃. Due to the wholly sealed construction, the reference electrode is stable, temperature-reversible, contamination free to …

Anodic Polarization Behaviors Of Carbon Steel In Bicarbonate Solution, Jing-Mao Zhao, Yu Zuo

Journal of Electrochemistry

The anodic polarization curves of mild steel were measured in sodium bicarbonate solution of various concentrations, and the surface products were analyzed by XPS. Two anodic current peaks and two passive zones are observed in all the curves. When HCO₃^- ions concentration is below 0.1mol/L, the two peaks are so close that the first passive zone is difficult to be observed. When HCO₃^- ions concentration is above 0.1 mol/L, the first peak appears clear, while the second becomes smaller. The XPS results indicate that the out layer of film formed at a higher potential is mainly …

Preparation And Characterization Of Lini0.85Co0.10(Timg)0.025O2 As Cathode Materials For Lithium-Ion Batteries, Xian-Jun Zhu, Hong-Hao Chen, Hui Zhan, Dai-Ling Yang, Yun-Hong Zhou

Journal of Electrochemistry

Cathode material of LiNi_0.85Co_0.10(TiMg)_0.025O₂ were prepared by solid state reaction at 725℃ for 24 h from LiOH·H₂O, Ni₂O₃, Co₂O₃, TiO₂ and Mg(OH)₂ under flowing oxygen, and were characterized by TG-DTA, XRD, SEM and electrochemical tests. Effort to simultaneously doped LiNiO₂ with Co-Ti-Mg has been tried to improve the cathode performance. The results show that co-doping definitely has a large beneficial effect in increasing the capacity (182.7mAh/g of the first discharge capacity for  LiNi_0.85Co_0.10(TiMg)_0.025O_{2 …}

Corrosion Resistance For Tio2 Thin Films Coated 316l Stainless Steel In The Nacl Solution, Guang-Xia Shen, Yi-Cong Chen, Chang-Jian Lin

Journal of Electrochemistry

The nano-TiO₂ thin films have been deposited on the 316L stainless steel by sol-gel and the dip-coating methods. Hydrothermal post-treatment leads to crack-free coatings. Meanwhile, the surface structure and properties are optimized. Surface morphology, structure and properties are characterized by XRD, and SEM technologies. The results have shown that the surface of coatings is porous, uniform and orderly, the particle diameters are in the range of 15~18 nm and the pores are about 4~8 nm and TiO₂ is anatase. The results of electrochemical measurements show that in the NaCl solution with pH ≥ 2 and concentration below 1mol/L, …

Calcium Zincate Prepared By Ball Mill Method, Sheng-Xian Li, Shuan-Bao Tian, Shao-Shan Zhu

Journal of Electrochemistry

Calcium zincate was prepared by ball milling method and the factors that influence its synthesis were investigated. The composition of the compound was Ca(OH)₂·2Zn(OH)_2^·2H₂O, which was verified by XRD and TG-DTA methods. The results of powder microelectrode and in simulated batteries showed that the material had excellent cyclic performance.

Influence Of Rare Earth Oxide On The Performance Of Secondary Zinc Electrodes, Xian-Ling Meng, Hua-Bin Yang, Jun-Hong Wang, Zuo-Xiang Zhou

Journal of Electrochemistry

Influence of La(OH)₃ or Ce(OH)₃ in secondary zinc electrode was investigated by the cyclic voltammetry, potentiodynamic polarizationand potentiostatic polarization tests and influence of La₂O₃ or CeO₂ in the charge/discharge performance of Zn/Ni battery was studied by galvanostatic charge/discharge experiment. The results showed that the film of rare earth hydroxide prevented the zincate species from transferring toward solution, enhanced hydrogen overpotential and decreased thecorrosion current density (i_corr), and therefore inhibited zinc corrosion. The potentiostatic polarization results at100mV overpotential showed that La(OH)₃ or Ce(OH)₃ oated on the zinc electrode effectively suppressed the …

The Fabrication And Electrochemical Studies On Carbon Nanotube Array Electrodes, Quan-Yong Gao, Jing Zhang, Yong Yang

Journal of Electrochemistry

An improved technique for fabrication of carbon nanotube array electrodes has been proposed in this work. Firstly, carbon nanotubes (CNs) array electrodes were prepared by combsination of Chemical Vapor Decomposition (CVD) method and sputtering techniques in anodized aluminum oxide (AAO) membrane. The CNs/AAO was immersed into HF solution to remove the barrier layer. Controlling the immersing time, the CNs array electrodes with different length contacted with electrolyte can be prepared. The morphology of CNs array electrodes was observed by SEM. The electrochemical properties of CNs array electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Cyclic voltammetric curves of …

Corrosion Behavior Of Mg2-XLaXNi And Mg2-XCeXNi Hydrogen Storage Alloy, Hai-Chang Zhang, Hua-Bin Yang, Jun-Hong Wang, Zuo-Xiang Zhou

Journal of Electrochemistry

The corrosion behavior of Mg-base hydrogen storage alloys has been investigated by potentiodynamic polarization and EIS. The results showed that the corrosion current density (i_corr) and the electrochemical polarized resistance of Mg_2-xCe_xNi alloys decreased with x increase, while i_corr of Mg_2-xLa_xNi alloys increased and the electrochemical polarized resistance of Mg_2-xLa_xNi alloys increased first, then decreased with x increase. SEM results showed that the surface of Mg_1.85Ce_0.15Ni alloy was relatively even while the surface of Mg_2-xLa_xNi alloy had …

A Study Of Metal Borides As High Capacity Anode Materials For Aqueous Primary Batteries, Ya-Dong Wang, Xin-Ping Ai, Han-Xi Yang

Journal of Electrochemistry

The transition metal borides VB₂ and TiB₂ were tested as high capacity anode materials and their electrochemical behaviors were studied by cyclic voltammetry and discharge measurements. The experimental results indicated that transition metal borides VB₂ and TiB₂ electrodes can deliver exceptionally high discharge capacity of over 3100 mAh/g and 1 600 mAh/g respectively, corresponding to 11- and 6-electron oxidation reaction, although their parent elements V, Ti and boron, are almost completely electrochemically inert. The different electrochemical activitis were probably due to the electrochemical activation of boron, which clamp the potential to passivation for Ti and activity …

Electrochemical Performance Of Gel Polymer Electrolyte Prepared By Thermal Initiating Polymerization Of Acrylates, Jin-Dan Piao, Li-Xia Yuan, Xin-Ping Ai, Han-Xi Yang, Yu-Liang Cao

Journal of Electrochemistry

A gel polymer electrolyte was prepared by thermal initiating polymerization of the acrylates in the EC/EMC/DMC electrolyte solution at 100℃. The LiCoO₂/MCMB polymer cells were assembled and their electrochemical properties were evaluated at various charge-discharge rate and temperatures. The ionic conductivity of the polymer electrolyte containing 85wt.% liquid electrolyte is around 3.2×10^-3 S·cm^-1  at 20℃ and 5.6×10^-4 S·cm^-1 at -30℃ respectively. The gel polymer electrolyte has good electrochemical stability up to 4.5V versus Li/Li⁺.The first charge-discharge efficiency of the polymer cell at 0.2C rate is almost 92.1%. The discharge capacity of the …

Application Of Carbon Paste Electrode On The Electrogenerative-Leaching Process Of Sulfide Minerals, Shao-Fen Wang, Zheng Fang, Yun-Yan Wang

Journal of Electrochemistry

The cyclic voltammetry curves of sulfide mineral electrodes or corresponding carbon paste electrodes in NaCl electrolytes have been obtained in this study. The experimental results indicate that acetylene black (revealed) the electro-catalytic propertyin the electrogenerative-leaching process of sulfide minerals. The output currentand potential of carbon paste electrodes were increased to some degrees while the activation energies were lower.

Preparation Of Poly (Bromophenol Blue) Modified Glassy Carbon Electrode And Its Electrocatalytic Activity, Wei Chen, Hong-Bin Luo, Xin-Hua Lin

Journal of Electrochemistry

A film of poly (bromophenol blue) was formed on a glassy carbon electrode by using cyclic voltammetry. A stable film could be obtained with a potential range from -1.0 V to +1.8 V (vs.Ag/AgCl). The experimental results showed that the poly (bromophenol blue) modified glassy carbon electrode could catalyse the oxidation of ascorbic acid. It decreased the oxidation potential by about 270mV but increased the peak current. Meanwhile, this electrode showed a good linear current response for the ascorbic acid range from 2.5 to 250 (g/mL).

Research On Phenol Wastewater Treatment By Electrochemical Oxidation, Tian-Cheng Li, Shen-Lin Zhu

Journal of Electrochemistry

Electrochemical oxidation is an effective technology for the phenol wastewater treatment, and the anode properties are important to the electrochemical oxidationefficiency. The over-potentials of oxygen evolution have been measured for thestainless steel, feasible graphite and SnO₂/Ti anode respectively. Moreover, the synthetic phenol wastewater was treated by the electrochemical oxidation with the stainless steel or feasible graphite anodes. The experimental results showed that the order of the over-potential is SnO₂/Ti > graphite > stainless steel; meanwhile, the COD values of purified water were approaching to or less than 100 mg·L^-1, and the phenol concentrations in the purified …

Using Neural Networks To Identify The Effect Of Construction Factors On The Cost Of Reinforced Concrete Elements, Ahmed Aly El-Sotouhy

Archived Theses and Dissertations

No abstract provided.

Engineering Tools For Variable Stiffness Vibration Suppression And Isolation, Michael F. Winthrop

Theses and Dissertations

With the advent of smart materials, the concept of semi-active control or dynamic control of stiffness and/or damping for vibration control of structures has become practical and has seen limited use. Semi-active control has advantages over active and passive control methods, since it provides almost as much capability as active control while requiring much less power. Its main disadvantage is its inherent nonlinearity, greatly complicating engineering design. The purpose of this research is to extend semi-active control vibration isolation tools and methods considering space launch and on-orbit systems.

Me-Em 2005 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering Annual Reports

Table of Contents

• Overview, Mission, and Vision
• Comments on the Strategic Plan
• Enrollment and Expenditure Data
• Professional Advisory Committee
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• Students
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Medical Technology: Contexts And Content In Science And Technology, Michael A. De Miranda, Mark Doggett, Jane T. Evans

Architectural and Manufacturing Sciences Faculty Publications

No abstract provided.