Engineering Science and Materials Commons^™

Preparation And Electrochemical Performance Of Mo-Doped Li3V2(Po4)3/C Cathode Materials, Zhi-Yuan Tang, Wei Yuan, Ji Yan, Wen-Feng Mao, Li Ma

Journal of Electrochemistry

The molybdenum-doped Li₃V_2-xMo_x(PO₄)_3/C (x = 0.01, 0.02 and 0.03) cathode materials were prepared with a sol-gel method by using Li₂CO₃, NH₄H₂PO₄, V₂O₅ and MoO₃ as raw materials, and citric acid as both chelating reagent and carbon source. The X-ray diffraction (XRD) analyses showed that the crystal structure of as-prepared samples is monoclinic with space group P2₁/n. Scanning electron microscopy (SEM) observations indicated the uniform morphology for Li₃Mo_0.02V_1.98(PO₄) …

Synthesis And Electrochemical Properties Of Lifeso4F/Graphene Composite As Cathode Material For Lithium-Ion Batteries, Wei Guo, Ya-Xia Yin, Li-Jun Wan, Yu-Guo Guo

Journal of Electrochemistry

The LiFeSO₄F was successfully synthesized from the reactions of FeSO₄∙xH₂O (x=1, 4, 7) with LiF in tetraethylene glycol media through a facile low temperature method. The structures and microscopic features of the products were characterized by XRD, SEM and TEM. TGA result shows the good thermal stability of the as-prepared LiFeSO₄F. No diffraction peaks of the FeSO₄ are observed in the as-prepared products with the starting material of either FeSO₄∙4H₂O or FeSO₄∙7H₂O, which should be ascribed to delaying the release of H_{2 …}

Corrosion Inhibition Of 316l Steel Using Sodium Diethyl Dithiocarbamate Solution In Simulated Crude Oil, Xiao-Guang Ren, Jie Yang

Journal of Electrochemistry

The corrosion inhibition behaviors of 316L steel using the sodium diethyl dithiocarbamate (SDDTC) compound in the crude simulation solution were studied in the absence and presence of zinc sulfate or sodium chromate with different compositions. Experiment resultss showed that in the environments of highly acidic and high concentrations of chloride ions the SDDTC compound could well inhibit the corrosion of 316L steel. The good synergic effects on the corrosion inhibition of 316L steel by additions of either zinc sulfate or sodium chromate into SDDTC compound were indicated in this study, which is of great significance and importance in practical applications.

Ethanol Electrooxidation On Pt/Mo2/Cnts Catalysts, Yu-Long Cheng, Jie Sun, Ji-Gang Li, Li-Gong Zhang, Tian Zhou, Geng Chang, Zhong-Chao Dong

Journal of Electrochemistry

The ethanol electrooxidation behaviors on Pt/MO₂/CNTs（M=Sn, Ti, Ce）and Pt/CNTs catalysts in H₂SO₄ solutions were researched by cyclic voltammetry. It has revealed that the catalysts with the addition of metal oxides presented higher electrooxidation activity for ethanol, in particular, the Pt/CeO₂/CNTs catalyst showed the best activity for ethanol electrooxidation intermediate. The Pt/SnO₂/CNTs catalyst demonstrated the best ethanol electrooxidation activity when considering the synthetic effects of such parameters as the onset oxidation potential, peak current densities and total oxidation area.

Catalytic Activities Of Electrochemically Dealloyed Pt(Pd)-Cu Catalysts For Oxygen Reduction Reaction, Rui-Zhi Yang, Strasser Peter, Toney Michael

Journal of Electrochemistry

The electrochemically dealloyed Pt(Pd)-Cu catalysts were prepared by electrochemical dealloying of Cu₃Pt(Pd) and their catalytic activities toward oxygen reduction reaction (ORR) were studied in 0.1 mol·L^-1 HClO₄ . solutions. The structural features of the dealloyed Pt(Pd)-Cu were revealed by synchrotron-based anomalous X-ray diffraction (AXRD) and surface X-ray scattering (SXS) at an atomic scale. We established a relationship between the structure and the catalytic activity by comparing the ORR activity and the structure of dealloyed Cu₃Pt nanoparticles with similarly dealloyed Cu₃Pt thin films and Cu₃Pt(111). The enhancement in the activity of …

Electrocatalytic Oxidation Of Ethanol On Ni-P-Tio2 Composite Coating Electrodes, Guang-Hui Hu, Hai-Xia Zeng, Zhi-Gang Wei, Zhan-Chang Pan, Shu-Guang Xie, Yan-Di Zou

Journal of Electrochemistry

The Ni-P-TiO₂ composite coating electrodes with different contents of TiO₂ particulates were prepared by electroless plating technique from Ni-P plating bath containing TiO₂ powders on brass. Cyclic voltammetry, linear sweep voltammetry (LSV), chronoamperometry and electrochemical impedance spectroscopy (EIS) were used to test the electrochemical performance of Ni-P-TiO₂/Cu electrodes. It was indicated that the Ni-P-TiO₂/Cu electrodes exhibited very strong electrocatalytic activity toward the oxidation of ethanol in alkaline medium at ambient temperature. The electrocatalytic activity of ethanol oxidation on the Ni-P-TiO₂ electrodes depended on the amounts of TiO₂ in the coatings. The …

Numerical Modeling Of High Temperature Bayonet Heat Exchanger And Decomposer For Decomposition Of Sulfur Trioxide, Vijaisri Nagarajan, Yitung Chen, Tzu-Chen Hung, Qiuwang Wang, Valery Ponyavin

College of Engineering: Graduate Celebration Programs

Motivation

• Hydrogen is an attractive energy carrier in the future energy technology.

• Hydrogen is produced from splitting of water through various process namely electrolysis, photo-electrolysis, photo-biological production and thermochemical water-splitting.

• The aim of this study is to numerically investigate fluid flow, heat transfer and chemical reaction in bayonet high temperature heat exchanger and decomposer.

• Parametric studies are performed to achieve maximum decomposition with less pressure drop.

Cellular Automaton For Simulation Of Oxide Layer Growth Influenced By Chromium Concentration Of Structure Material, Kuan-Che Lan, Yitung Chen, Ge-Ping Yu, Tzu-Chen Hung

College of Engineering: Graduate Celebration Programs

Chromium, an important alloying element, has been added in ferrous and nickel based alloy such as stainless steels and Inconel alloy to improve the corrosion resistance. High corrosion resistance of structural materials in extremely high working temperature is one crucial R&D objective of Gen IV nuclear power plants which propose to raise the thermal efficiency via high working temperature. A cellular automaton (CA) model based on the stochastic approach was proposed to simulate the process of oxidation and corrosion of structural material in flowing fluid. The relation of chromium concentration against oxide layer thickness during a specific period was found. …

Thermal Conductivity Measurement With 3Ω Method Background And Synopsis Of Its Implementation, Fiifi Blankson

College of Engineering: Graduate Celebration Programs

ABSTRACT

Continued advances in nanostructured materials have made it necessary to develop materials with specific thermoelectric properties. The 3ω Method provides an accurate measurement of one such property, thermal conductivity. It will be used in this research to find high electrical conductivity alloys with low thermal conductivity.

Acoustic Emission Detection Of Metals And Alloys During Machining Operations, Jameson K. Nelson

Purdue Polytechnic Masters Theses

Nelson, Jameson K. M.S., Purdue University, May 2012. Acoustic Emission Detection of Metals and Alloys During Machining Operations. Major Professor: Rodney G. Handy.

Practical correlation between material deformation attributes and theoretical concepts of machining has proven difficult to attain. The purpose of this study was to further explore trends and relationships using acoustic emission detection of materials undergoing single-point lathe turning machine processes. The majority of machining experiments that incorporate acoustic emissions focuses on tool degradation for the purposes of optimizing consumables required to manufacture mechanical devices. Experiments were implemented varying recording location, mechanical barrier condition, and machine parameters. The …

Model-Based Systems And Methods For Analyzing And Predicting Outcomes Of Vascular Interventions And Reconstructions, Yuris A. Dzenis, Alexey Kamenskiy, Iraklis I. Pipinos, Jason N. Mactaggart

Department of Mechanical and Materials Engineering: Faculty Publications

Systems and methods for analyzing and predicting treatment outcomes of medical procedures such as vascular interventions and reconstructions are disclosed. An illustrative system for analyzing and predicting therapeutic outcomes of medical procedures comprises a relational database configured for classifying and storing patient specific input data for multiple patients, a fluid-solid interaction biomechanical model configured for performing a biomechanics simulation and generating biomechanics data, and a graphical user interface.

Peridynamic Model For Dynamic Fracture In Unidirectional Fiber-Reinforced Composites, Wenke Hu, Youn Doh Ha, Florin Bobaru

Department of Mechanical and Materials Engineering: Faculty Publications

We propose a computational method for a homogenized peridynamics description of fiber-reinforced composites and we use it to simulate dynamic brittle fracture and damage in these materials. With this model we analyze the dynamic effects induced by different types of dynamic loading on the fracture and damage behavior of unidirectional fiber-reinforced composites. In contrast to the results expected from quasi-static loading, the simulations show that dynamic conditions can lead to co-existence of and transitions between fracture modes; matrix shattering can happen before a splitting crack propagates. We observe matrix–fiber splitting fracture, matrix cracking, and crack migration in the matrix, including …

A High Bandwidth Non-Destructive Method For Characterizing Simple Media, Matthew L. Szuster

Theses and Dissertations

The relative complex permittivity can be extracted with time domain data from a perfect electrical conductor (PEC) backed sample of a low-loss, non-dispersive dielectric using dual ridged waveguide aperture probes with attached PEC flange plates of the same geometry and different dimensions. The temporal domain measurement of interest is the ability to detect the reflection from the edge of the flange plate in the parallel region created by the flange plate and the PEC backing on the dielectric sample. Signal processing windows are applied to the data in order to exploit this edge reflection. The types of signal processing methods …

Silicon Carbide Capacitive High Temperature Mems Strain Transducer, Richard P. Weisenberger

Theses and Dissertations

Air Force Research Lab Air Vehicles directorate performs research on hypersonic vehicles. To verify materials or designs of hypersonic vehicles, they have a need to measure strain at temperatures exceeding 700°C. Strain sensors have the ability to measure strain. Strain is the deformation of materials due to internal stresses in a material. Internal stresses occur when a material is subjected to a force. Traditional strain sensors use Piezoresistive effects to measure strain, which is temperature dependent and making them unusable at high temperatures. This paper discusses a novel strain sensing device, sensing capacitance instead of piezoresistance. The strain sensor is …

High Speed Friction Stir Spot Welding On Dp 980 Steel:Joint Properties And Tool Wear, Nathan David Saunders

Theses and Dissertations

With the desire to improve passenger safety and fuel efficiency, Ultra High Strength Steels (UHSS) have been developed for use in the automotive industry. UHSS are high strength steels with high ductility and strength. DP 980 is one of these UHSS being applied in automobile manufacturing. DP 980 is difficult to join with Resistance Spot Welding (RSW) because of the high carbon content and alloying in this material. The weld becomes brittle when it solidifies during the welding process. With the desire and motivation of widely using UHSS, new welding processes are needed to be developed in order to effectively …

Me-Em Enewsbrief, March 2012, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Preparation And Electrochemical Performance Of Lifepo4/C By Spray Drying Method Assisted With Organic Template, Quan-Bing Liu, Yang-Mei Jiang, Hui-Yu Song, Shi-Jun Liao

Journal of Electrochemistry

In this work, the LiFePO₄/C composites were prepared by the spray drying and carbothermal method, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The effects of the organic assisted templates on the morphologies and electrochemical properties of the LiFePO₄/C composites were investigated. The results showed that the morphology and microstructure of the composites could be tuned by incorporating with the different templates. The morphology of the composite appeared to be solid microspheres if no organic template was added, while porous microspheres, nest-like …

Synthesis And Electrochemical Performance Of Xlifepo4·Yli3V2(Po4)3 Composites, Ping-Ping Ma, Zhi-Jian Liu, Jian-Hua Xia, Yu Chen, Pu Hu, Zhi-Chao Lu, Ding-Guo Xia

Journal of Electrochemistry

A series of xLiFePO₄·yLi₃V₂(PO₄)₃ composites were systematically synthesized through solid state reactions by variations in the proportions of LiFePO₄ and Li₃V₂(PO₄)₃. The properties of the prepared compounds were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. The capacity of 162.7 mAh/g at 0.2 C rate was obtained with the relatively good cycle stability and good conductivity for 0.95LiFePO₄·0.05Li₃V₂(PO₄)₃ due to more uniformed distributed and smaller particle sizes.

Preparation And Characterization Of Mno/Tin Anode For Lithium Ion Batteries, Gao-Jie Xu, Hai-Yan Yang, Peng-Xian Han, Li-Xue Zhang, Ke-Jun Zhang, Chuan-Jian Zhang, Yu-Hua Fan, Cai-Feng Bi, Guang-Lei Cui

Journal of Electrochemistry

Manganese titanate (MnTiO₃) powder was prepared via a sol-gel method using manganese acetate and tetrabutyl titanate as raw materials, and citric acid as a chelating agent. Through high temperature nitridation of MnTiO₃ powder in ammonia, the MnO/TiN composite was obtained. The phase structure, composition and morphology of the composites were characterized by XRD, SEM and EDS. The electrochemical properties of the composite electrodes were studied by performing cyclic voltammetry, galvanostatic charge and discharge, and electrochemical impedance spectroscopy tests. The MnO/TiN electrode delivered specific capacities of 394 mAh·g^-1 and 146 mAh·g^-1 at the current density of …

Preparation And Hydrogen Evolution Properties Of Ni/Ag2O/Ruo2-Pt Cathodes, Shu Huang, Xue-Ming Li, Wu-Lin Li, Wen Wang

Journal of Electrochemistry

The Ni/Ag₂O/RuO₂-Pt composite cathode was prepared by sol-gel method using RuCl₃ and H₂PtCl₆ as raw materials. The effects of heat treatment conditions and AgNO₃ concentrations on hydrogen evolution properties were investigated. The morphology and composition of Ni/Ag₂O/RuO₂-Pt composite cathode have been characterized by XRD, XPS and SEM-EDS. It is demonstrated that the surface structure of Ni/Ag₂O/RuO₂-Pt composite cathode is more compact, with fewer cracks and larger surface roughness than pure nickel. At the conditions of 0.3 A·cm^-2, 90 ^oC, and …