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Articles 4141 - 4170 of 5701

Full-Text Articles in Engineering

Dynamics Of Ultrasonic Consolidation, James Gibert Dec 2009

Dynamics Of Ultrasonic Consolidation, James Gibert

All Dissertations

Ultrasonic consolidation (UC) is a solid state rapid manufacturing process derived from ultrasonic welding of thin metal foils coupled with contour milling to achieve functional accurate components. The bonding of metal is accomplished by the local application of high frequency vibration energy under pressure producing a metallurgical bond without melting the base material. Its unique nature allows the design and fabrication of structural panels for satellites, production of injection molding tools, functionally graded structures, metal-matrix composites, embedded sensors, armor, and fiber embedded adaptive structures. It is commonly theorized that interfacial motion and friction at the bonding interface play a prominent …

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Platinum Modified With Hydrogen Molybdenum/Tungsten Bronze As Electrocatalysts For Direct Small Organic Molecule Fuel Cell, Wei-Shan Li, Li-Peng Tian, Jun-Hua Du, Hong-Liang Huang, Wei Li, Li-Xia Zhang, Hong-Yan Yang, Pan-Pan Guo, Zhi-Hui Zhou, Xing-De Xiang, Zhao Fu Nov 2009

Platinum Modified With Hydrogen Molybdenum/Tungsten Bronze As Electrocatalysts For Direct Small Organic Molecule Fuel Cell, Wei-Shan Li, Li-Peng Tian, Jun-Hua Du, Hong-Liang Huang, Wei Li, Li-Xia Zhang, Hong-Yan Yang, Pan-Pan Guo, Zhi-Hui Zhou, Xing-De Xiang, Zhao Fu

Journal of Electrochemistry

There are several problems that limit the application of direct small organic fuel cell,including the use of precious platinum and the activity loss of platinum due to the intermediates poisons from the oxidation of small organic molecules.These problems have attracted wide interest and many solutions have been proposed.We have developed a new method to reduce the platinum usage and improve its activity,based on the modification of platinum with hydrogen molybdenum/tungsten bronze(HxMo(W)O3) was reviewed.

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Preparation Of Pt Nanoflower/Zno Composites Arrays And Their Electrocatalysis For Methanol Oxidation, Li Gao, Yi-Feng E, Lou-Zhen Fan Nov 2009

Preparation Of Pt Nanoflower/Zno Composites Arrays And Their Electrocatalysis For Methanol Oxidation, Li Gao, Yi-Feng E, Lou-Zhen Fan

Journal of Electrochemistry

The Pt nanoflower/ZnO(PtNF/ZnO) nanorod composites arrays were electrochemically prepared by controlling the hydrophobicity and the hydrophilicity of ZnO nanorods arrays.The Pt nanoflowers grew on the tip of ZnO nanorods,which maintain the vertical array of Zno nanorods with a high degree of size uniformity and high surface area.Compared with Pt nanoparticle covered ZnO nanorod arrays,which were prepared by controlling the hydrophilicities of ZnO nanorods and Pt nanoparticles,the PtNF/ZnO displayed highest electrocatalytic activities for the oxidation of methanol.

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Indirect Electrosynthesis Of Double Aldehyde Starch Using Pb-(Bro3-/Br-) As Electro-Catalytic Mediator, Ni-Na Chen, Ri-Yao Chen, Xi Zheng, Xiao Chen, Zhen Chen Nov 2009

Indirect Electrosynthesis Of Double Aldehyde Starch Using Pb-(Bro3-/Br-) As Electro-Catalytic Mediator, Ni-Na Chen, Ri-Yao Chen, Xi Zheng, Xiao Chen, Zhen Chen

Journal of Electrochemistry

In this paper,Nafion membrane was used as the separator in the electrolysis cell to indirectly electro-generating the double aldehyde starch(DAS) with BrO3-/Br-as a redox mediator and Pb as an anode.Effects of temperature,concentration of sulfuric acid and starch on the electro-oxidation of DAS were discussed.The steady state polarization curves were obtained.The experiment results showed that the current efficiency was over 50% when the electrolysis current density was 15mA/ cm2.

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Preparation Of Polyaniline/Polyester Conductive Fabric Via In-Situ Polymerization, Fang Na, Wei Wang Nov 2009

Preparation Of Polyaniline/Polyester Conductive Fabric Via In-Situ Polymerization, Fang Na, Wei Wang

Journal of Electrochemistry

The formation of PANI coating on the surface of PET fiber and fabric was obtained by in-situ polymerization method.The coating′s thickness was about 1～2 μm.Orthogonal test methodology was used to analyze the main factors of preparation of PANI / PET conductive fabric.The effects of the aniline monomer concentration,oxidant: aniline molar ratio,doping acid concentration and types,reaction time on the conductivities of the fabric were studied.The structure of the polymer were characterized by SEM,FTIR and XRD.The results indicated that there was uniform and continuous polyaniline film on the surface of polyester fabric.The contents of oxidation and reduction of polyaniline molecular chain structure …

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Electrocatalytic Activities Of Au-Mmni(3.2)Al(0.2)Mn(0.6)Co(1.00) For Borohydride Oxidation, Gui-Ling Wang, Jin-Cheng Liu, Ke-Ning Sun, Dian-Xue Cao Nov 2009

Electrocatalytic Activities Of Au-Mmni(3.2)Al(0.2)Mn(0.6)Co(1.00) For Borohydride Oxidation, Gui-Ling Wang, Jin-Cheng Liu, Ke-Ning Sun, Dian-Xue Cao

Journal of Electrochemistry

In this work,the electrocatalytic activities of MmNi3.2Al0.2Mn0.6Co1.0, NaOH treated MmNi3.2Al0.2Mn0.6Co1.0 and Au-MmNi3.2Al0.2Mn0.6Co1.0 obtained after NaOH treatment(Mm: misch metal) for NaBH4 oxidation were reported. The electrodes were prepared by electrodeposition, their morphologies were analysized by SEM, their electrocatalytic properties were studied by the linear sweeping test. It was found that the oxidation current density of the Au-MmNi3.2Al0.2Mn0.6Co1.0 was 60 mA·cm-2, it was 3.5 times higher than that at the …

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Electrocatalytic Performance Of Carbon Supported Ir Catalysts With Different Ir Loadings For Ammonia Oxidation, Yu-Zhi Jiang, Qing-Mei Kong, Tian-Hong Lu, Yi-Ming Zhou, Ya-Wen Tang Nov 2009

Electrocatalytic Performance Of Carbon Supported Ir Catalysts With Different Ir Loadings For Ammonia Oxidation, Yu-Zhi Jiang, Qing-Mei Kong, Tian-Hong Lu, Yi-Ming Zhou, Ya-Wen Tang

Journal of Electrochemistry

The electrocatalytic performance of the Ir/C catalyst as the anodic catalyst in the amperometric and electrochemical NH3 sensor was investigated.The experimental results illustrated that in the NaClO4 neutral electrolyte,the electrocatalytic performance of the Ir/C catalyst for the NH3 oxidation is related to the Ir loading in the Ir/C catalyst.Among the Ir/C catalysts with different Ir loading,the best electrocatalytic activity,stability and sensitivity were achieved by the Ir/C catalyst with 10% Ir loadings.In addition,the current densities of the NH3 oxidation at the Ir/C catalysts with the different Ir loadings were linearly proportional to the NH3 concentration.The Ir/C …

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Progresses In Electrocatalysis Of Nanomaterials—Tuning The Surface Structure And Property Of Electrocatalysts, Yan-Xia Jiang, Na Tian, Zhi-You Zhou, Sheng-Pei Chen, Shi-Gang Sun Nov 2009

Progresses In Electrocatalysis Of Nanomaterials—Tuning The Surface Structure And Property Of Electrocatalysts, Yan-Xia Jiang, Na Tian, Zhi-You Zhou, Sheng-Pei Chen, Shi-Gang Sun

Journal of Electrochemistry

The property of an electrocatalyst depends strongly on its surface structure.The study of surface structure-catalytic functionality is the base of design and preparation of electrocatalysts of high activity,high stability and high selectivity at microstructure level.In this paper,based mainly on our results concering hydrogen and oxygen adsorption-desorption,ethylene glycol oxidation and CO2 reduction,the research progresses in tuning the surface structure and property of electrocatalysts are summarized.This paper overviews firstly the cyclic voltammetric characteristics,electrocatalytic properties of platinum single crystal planes lying on different crystallographic zones of the unit stereographic triangle of face-centered cubic(fcc) metals.Next,the innovation of electrochemical methods to control the surface …

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Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen Nov 2009

Synthesis And Electrocatalytic Properties Of Ni-Pd/C Catalysts With Pd-Enriched Surface, Yu-Mei Chen, Zhi-Xiu Liang, Sheng-Li Chen

Journal of Electrochemistry

The Ni-Pd alloy catalysts with Pd-enriched surface were synthesized through a modified polyol process.The synthesized materials were investigated by XRD and electrochemical methods,and tested as electrocatalysts for CH3OH-tolerant oxygen reduction.The results indicated that the synthesized Ni-Pd nanoparticles possess multiple phases containing Pd-Ni alloy and pure Ni.Comparing with Pd/C,the prepared Ni-Pd/C nanoparticles exhibited better resolved voltammetric peaks between the hydrogen absorption and adsorption,and positively shifted current peaks for the reduction of Pd oxide.The prepared Ni-Pd alloys with Pd-enriched surface have significantly enhanced ORR activity and improved CH3OH tolerance as comparing with Pd/C catalysts.

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Electrooxidation Of Formic Acid On Pd-Ni Alloy Film Electrode-The Effect Of Dealloying, Chao Wang, Fei-Fei Shi, Jin-Yi Wang, Han-Xuan Zhang, Wen-Bin Cai Nov 2009

Electrooxidation Of Formic Acid On Pd-Ni Alloy Film Electrode-The Effect Of Dealloying, Chao Wang, Fei-Fei Shi, Jin-Yi Wang, Han-Xuan Zhang, Wen-Bin Cai

Journal of Electrochemistry

A Pd-Ni alloy film was electrodeposited on Au disc electrode at a constant potential from a weakly basic bath containing PdCl2,NiSO4 and ethylenediamine.The as-deposited film was then subjected to potential cycling in a perchloric acid solution for surface dealloying treatment.The dealloyed Pd-Ni film electrode was examined for the electrocatalytic oxidation of formic acid,and compared with the as-deposited one as well as a Pd film electrode.The FE-SEM and electrochemical measurements on the Pd-Ni films revealed that the dealloying treatment caused a surface roughening and an increase in specific surface reaction area.The ICP-AES and XPS analyses demonstrated that the …

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Complex Reduction Preparation Of Carbon Supported Pd Nanoparticle Catalyst And Its Electrocatalysis For Formic Acid Oxidation, Wei He, Yong-Yin Kang, Chong Du, Zhi-Qing Zou, Xiao-Gang Zhang, Hui Yang Nov 2009

Complex Reduction Preparation Of Carbon Supported Pd Nanoparticle Catalyst And Its Electrocatalysis For Formic Acid Oxidation, Wei He, Yong-Yin Kang, Chong Du, Zhi-Qing Zou, Xiao-Gang Zhang, Hui Yang

Journal of Electrochemistry

A simple procedure involved the complexing of PdCl2 with sodium citrate followed by ethylene glycol reduction has been employed for the preparation of carbon-supported Pd nanoparticles(Pd/C).The XRD and TEM characterizations indicate that Pd nanoparticles with a small particle size were well-dispersed on carbon support.The mean particle sizes of the Pd/C catalysts were found to be increased from 2.7 to 5.8 nm with heat-treatments at different temperature.The mass activity of the Pd/C catalyst for formic acid electrooxidation increased with the decrease in Pd particle size.However,the specific activity increased with Pd particle size.Furthermore,the Pd/C catalyst with a particle size of ca.3.6 …

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Cyclic Voltammetric And In-Situ Ftir Spectroscopic Studies Of Adsorption And Reduction Of No On Electrode Of Pt Nanoparticles, Qian Cheng, Yan-Xia Jiang, Dong-Mei Zeng, Shi-Gang Sun Nov 2009

Cyclic Voltammetric And In-Situ Ftir Spectroscopic Studies Of Adsorption And Reduction Of No On Electrode Of Pt Nanoparticles, Qian Cheng, Yan-Xia Jiang, Dong-Mei Zeng, Shi-Gang Sun

Journal of Electrochemistry

Adsorption and reduction of NO on electrode of Pt nanoparticles in acid solutions were studied by means of cyclic voltammetry(CV) and in-situ FTIR spectroscopy.The results indicated that the reduction of NO is a complicated process including the adsorption of NO on electrode surface.Two types of surface-bonded NO were determined on Pt nanoparticles.The weakly adsorbed NO was reduced between 0.6 V and-0.05 V,which yielded nitrous oxide(N2O) and ammonium(NH4+) as products;while the strongly bonded NO was reduced at more negative potentials between-0.05V and-0.15V,producing only NH4+ species.

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Research Progress Of Synergistic Effect Of Metal Oxides On Pt-Based Catalysts, Hui-Ping Yuan, Xun Guo, Xin-Ping Qiu, Wen-Tao Zhu, Li-Quan Chen Nov 2009

Research Progress Of Synergistic Effect Of Metal Oxides On Pt-Based Catalysts, Hui-Ping Yuan, Xun Guo, Xin-Ping Qiu, Wen-Tao Zhu, Li-Quan Chen

Journal of Electrochemistry

In this paper,the work of Pt-based catalysts modified by metal oxides as the anode catalysts of direct methanol fuel cell(DMFC) is reviewed.The relationship between the structure and the composition of the catalysts and the reaction mechanism,exiting problems and developing direction are discussed.

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Electrocatalysis In Polymer Electrolyte Membrane Fuel Cells, Li Li, Si-Guo Chen, Xue-Qiang Qi, Yao-Qiong Wang, Meng-Bo Ji, Lan-Lan Li, Zi-Dong Wei Nov 2009

Electrocatalysis In Polymer Electrolyte Membrane Fuel Cells, Li Li, Si-Guo Chen, Xue-Qiang Qi, Yao-Qiong Wang, Meng-Bo Ji, Lan-Lan Li, Zi-Dong Wei

Journal of Electrochemistry

This review presents the study of Chongqing University in electrocatalysis for polymer electrolyte membrane fuel cells(PEMFCs).Based on the understanding to the performance degradation of PEMFCs' catalysts,the university has being concentrated on how to increase the activity,stability and utility of noble metal catalysts.It covers the molecular design of near-surface alloy catalysts for improvement of activity to oxygen reduction reaction(ORR) and resistance to foreign poison species,selective deposition of Pt on the so-called "three-phase interface" for a high Pt utility,and invention of anti-flooding electrode against water flooding in the catalyst layer of the membrane assemble electrode(MEA),and so on.The catalytic mechanism of electrode reactions …

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Highly Durable Pt/Ruo2/C Catalyst For The Cathode Of Direct Methanol Fuel Cells, Chun-Yu Du, Tao Dong, Ge-Ping Yin, Peng-Fei Shi Nov 2009

Highly Durable Pt/Ruo2/C Catalyst For The Cathode Of Direct Methanol Fuel Cells, Chun-Yu Du, Tao Dong, Ge-Ping Yin, Peng-Fei Shi

Journal of Electrochemistry

Instability of the carbon-supported Pt(Pt/C) catalyst at the cathode is one of the key technical challenges for the development of Direct Methanol Fuel Cells(DMFCs).In this paper,an efficient approach to enhancing the stability of the cathode catalyst was explored by designing and synthesizing a novel nanocomposite support,RuO2 coated carbon black(RuO2/C).Firstly,a wet chemical method was employed to synthesize the RuO2/C nanocomposite,from which Pt/RuO2/C catalyst was further prepared by a microwave method.The morphology and crystalline structure of the RuO2/C support and Pt/RuO2/C catalyst were then characterized by TEM and XRD.Finally,the electrochemical performance …

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Enhanced Visible Light Photoelectrochemical Performances With Nitrogen Doped Tio2 Nanowire Arrays, Xiao-Jun Lv, Yue-Ming Li, Hao Zhang, Da Chen, Jennifer Hensel, Jin Z Zhang, Jing-Hong Li Nov 2009

Enhanced Visible Light Photoelectrochemical Performances With Nitrogen Doped Tio2 Nanowire Arrays, Xiao-Jun Lv, Yue-Ming Li, Hao Zhang, Da Chen, Jennifer Hensel, Jin Z Zhang, Jing-Hong Li

Journal of Electrochemistry

Self-organized anodic anatase TiO2 nanowire arrays doped with nitrogen have been successfully fabri-cated and their photoelectrochemical(PEC) properties have been characterized and found to be substantially im-proved compared to undoped nanowires or commercial P25 nanoparticles.Photocurrent measured with monochro-matic incident light showed that the incident photon-to-current efficiency(IPCE,%) values of nanowire arrayelectrodes with or without N-doping were obviously higher than that of commercial P25 nanoparticle electrodes,and nitrogen-doped TiO2 nanowire arrays(NTNA) had noticeable absorption in the visible region.The NTNAelectrodes showed the highest photocurrent density and power conversion efficiency under 100 mW/cm2 visiblelight illumination.A maximumolphotoconversion efficiency of 0.52% was achieved for the …

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Synthesis Of α-Mno2 Microspheres For The Application In Supercapacitor, Liang Wang, Gui-Chang Liu, Zhi-Cong Shi Nov 2009

Synthesis Of α-Mno2 Microspheres For The Application In Supercapacitor, Liang Wang, Gui-Chang Liu, Zhi-Cong Shi

Journal of Electrochemistry

The MnO2 microspheres were prepared through the oxidation of KMnO4 and MnCO3 microspheres precursor.The microstructure and supercapacitor properties of MnO2 were characterized by XRD,SEM and CV.The results show that MnO2 was in a poorly crystalline state with α-crystallographic form,the size of microspheres typically ranged from 0.5 to 2 μm.Loading 5 mg·cm-2 MnO2 microspheres had excellent capacitance behaviors in 2 mol·L-1(NH4)2SO4 solution.The specific capacitance was 135.6 F·g-1 with the scan rate at 2 mV·s-1,and 118.8 F·g-1 with the large scan rate at 100 …

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Enhanced [Ru(Bpy)3]2+-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li Nov 2009

Enhanced [Ru(Bpy)3]2+-Mediated Oxidation Of Guanine Prompted By Dhp, Bao-Lian Zhang, Wei Hong, Bao-Yi Lu, Hong Li

Journal of Electrochemistry

The effects of dihexadecyl phosphate(DHP) and multi-walled carbon nanotubes(MWNTs) on the oxidation of guanine mediated by[Ru(bpy)3]2+ on the ITO electrode have been investigated by cyclic voltammetry and differential pulse voltammetry.The results showed that [Ru(bpy)3]2+ can mediate the oxidation.In the range from 0.01 to 0.15 mmol·L-1,peak currents for guanine oxidation mediated by [Ru(bpy)3]2+ increased with the rise of DHP concentrations.On the contrary,cationic surfactant HTAC has the ability to weaken the mediated oxidation of guanine.In addition,the oxidative mechanism of guanine mediated by [Ru(bpy)3]2+ with the participation of DHP …

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Electrocatalysis Of Myoglobin-Chitosan-Au Colloid Film Modified Glass Carbon Electrode, Yu-Hua Qin, Jun Guo, Hui Xu, Li-Heng Zhou, Sheng-Tian Wang Nov 2009

Electrocatalysis Of Myoglobin-Chitosan-Au Colloid Film Modified Glass Carbon Electrode, Yu-Hua Qin, Jun Guo, Hui Xu, Li-Heng Zhou, Sheng-Tian Wang

Journal of Electrochemistry

The cyclic voltammgram of Mb/AAO/Au Colloid/GCE shows a pair of well-defined and nearly reversible peaks at about-0.20 V(vs.Ag/AgCl) in 0.1 mol/L NaAc-HAc buffer(pH = 5.4),being the characteristic peaks of the Mb heme Fe(Ⅲ) / Fe(Ⅱ)redox couples.The electron transfer between Mb and the electrode was greatly enhanced under present testing conditions.The effects of scan rate,pH and buffers concentration on the electrochemical behaviors of Mb were studied in detail.Position of the Soret absorbance band suggested that Mb in chitosan-colloidal gold hept its secondary structure similar to the native states.Oxygen was catalytically reduced by Mb in chitosan-colloidal gold films.

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Imprinting Polymerfilm On Patterned Substrate, Li Tan, Yen-Peng Kong, Stella W. Pang, Albert F. Yee Nov 2009

Imprinting Polymerfilm On Patterned Substrate, Li Tan, Yen-Peng Kong, Stella W. Pang, Albert F. Yee

Department of Mechanical and Materials Engineering: Faculty Publications

A method of applying a pattern on a topography includes first applying a polymer film to an elastormer member, such as PDMS, to form a pad. The pad is then applied to a substrate having a varying topography under pressure. The polymer film is transferred to the substrate due to the plastic deformation of the polymer film under pressure compared to the elastic deformation of the PDMS member pulls away from the polymer layer, thereby depositing the polymer layer, thereby depositing the polymer layer upon the substrate.

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Indentation Creep Analysis For Self Similar Indenters, Sandeep V. Thube Oct 2009

Indentation Creep Analysis For Self Similar Indenters, Sandeep V. Thube

Mechanical & Aerospace Engineering Theses & Dissertations

In indentation creep experiments, it is difficult to characterize the mechanical properties of small size specimens using conventional methods. This study uses finite element modeling to investigate rate-sensitive deformation of materials with different hardness and strain rate sensitivities for self similar indenter tip geometries. The simulation model is developed using commercially available finite element software Abaqus/Standard. Our study investigates the difference between strain rate sensitivity of hardness (vH) and of flow stress (vu) and their relation to the hardness/modulus ratio. It reveals that the commonly held assumption that vH = vu is violated except for materials with low hardness/modulus …

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Application Of Systems Engineering To Rapid Prototyping For Close Air Support, John M. Colombi, Richard G. Cobb Oct 2009

Application Of Systems Engineering To Rapid Prototyping For Close Air Support, John M. Colombi, Richard G. Cobb

Faculty Publications

Twenty-first century military operations have brought forth many new challenges for the Armed Forces of the United States. One such challenge is with new operating environments, where current systems are not always effective. While it is desirable to apply a systems engineering approach to best meet critical user needs, there may be a misconception that systems engineering requires a lengthy and detailed process not nimble enough for a rapid prototyping effort. This article describes how a classic systems engineering methodology was successfully tailored to the rapid development of potential material solutions to meet a critical operational need. Key observations are …

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Me-Em Enewsbrief, September 2009, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Sep 2009

Me-Em Enewsbrief, September 2009, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

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Waves In Inhomogeneous Solids, Arkadi Berezovski, Mihhail Berezovski, Juri Engelbrecht Aug 2009

Waves In Inhomogeneous Solids, Arkadi Berezovski, Mihhail Berezovski, Juri Engelbrecht

Publications

The paper aims at presenting a numerical technique used in simulating the propagation of waves in inhomogeneous elastic solids. The basic governing equations are solved by means of a finite-volume scheme that is faithful, accurate, and conservative. Furthermore, this scheme is compatible with thermodynamics through the identification of the notions of numerical fluxes (a notion from numerics) and of excess quantities (a notion from irreversible thermodynamics). A selection of one-dimensional wave propagation problems is presented, the simulation of which exploits the designed numerical scheme. This selection of exemplary problems includes (i) waves in periodic media for weakly nonlinear waves with …

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Synthesis And Characterization For A New Organic Cathode Material Of Lithium-Ion Batteries——Poly Sulfurized Chloranilic Acid(Psca), Kai Liu, Jian-Ming Zheng, Gui-Ming Zhong, Yong Yang Aug 2009

Synthesis And Characterization For A New Organic Cathode Material Of Lithium-Ion Batteries——Poly Sulfurized Chloranilic Acid(Psca), Kai Liu, Jian-Ming Zheng, Gui-Ming Zhong, Yong Yang

Journal of Electrochemistry

A new organic cathode material,poly sulfurized chloranilic acid(PSCA),has been successfully synthesized for lithium-ion batteries. 13C solid state NMR and FTIR results indicated that the chorine in chronailic acid was substituted by sulfur after sulfurization. The electrochemical measurements showed that the initial discharge capacity of PSCA was up to 287.6 mAh/g,and 169.9 mAh/g still remained after 100 cycles when cycled between 1.5～3.6 V at the current density of 15 mA/g.

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Silicon Silver Composite Materials For Li-Ion Batteries, Lian-Bang Wang, Xiao-Bo Dai, Xin-Yan Zhu, Xin-Biao Mao, Chun-An Ma Aug 2009

Silicon Silver Composite Materials For Li-Ion Batteries, Lian-Bang Wang, Xiao-Bo Dai, Xin-Yan Zhu, Xin-Biao Mao, Chun-An Ma

Journal of Electrochemistry

properties of the composites were determined by charge-discharge tests and cyclic voltammetry. The composite composed of Si∶Ag with an atomic ratio of 1∶1 (sample 1#) showed good cyclic stability and charge-discharge reversibility. The reversible capacity of the composite (sample 1#) was remained over 300 mAh·g-1 after 50 cycles. Experimental results showed that controlling the potential range of charge-discharge processes could enhance the cyclic performance of alloy materials.

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Synergism Of Complex Additives Of Dtab+Ktl For Zinc Corrosion Inhibition In Koh Solutions, Sheng-Zhou Lin, Zeng-Xin Cai, Gui-Sheng Wang, He-Bing Zhou, Wei-Shan Li Aug 2009

Synergism Of Complex Additives Of Dtab+Ktl For Zinc Corrosion Inhibition In Koh Solutions, Sheng-Zhou Lin, Zeng-Xin Cai, Gui-Sheng Wang, He-Bing Zhou, Wei-Shan Li

Journal of Electrochemistry

The electrochemical behaviors of Zn in 3mol/L KOH solution containing several kinds of inhibitors were investigated by weight-loss,electrochemical methods and SEM. The results showed that both the single ad-ditive and the mixed additives can suppress the corrosion of zinc in 3 mol/LKOH solution. And the inhibition ef-feciency of the mixed additives is higher than that of any single additive because of the synergistic effect between KTL and DTAB. The adsorption of DTAB on the surface of zinc has been enhanced in the presence of KTL.

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A Study On The Lifepo4/Mwcnts Cathode Materials For Li-Ion Batteries, You-Yi Peng, Hai-Yan Zhang, Chun-Hua He, Wei Xie, Zhi-Feng Zeng Aug 2009

A Study On The Lifepo4/Mwcnts Cathode Materials For Li-Ion Batteries, You-Yi Peng, Hai-Yan Zhang, Chun-Hua He, Wei Xie, Zhi-Feng Zeng

Journal of Electrochemistry

The LiFePO4/MWCNTs composite was synthesized by ball milling,then the composite electrode was assembled into button lithium-ion batteries.The structure and morphology of the samples,the electrochemical performance of the electrodes were investigated by ways of X-ray diffraction,scanning electron microscopy,cyclic voltammetry and charge-discharge capacity tests. The electrochemical performance of the composite electrodes with different MWNTs contents were studied. The results indicated that the composite electrode containing 10% MWCNTs(by mass)exhibited the most excellent electrochemical performance with the initial charge-discharge capacities of 139 mAh·g-1,128.5 mAh·g-1,respectively,and a Kulun efficiency of 92.4% at 0.1C rate under room temperature.Compared to the electrodes …

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A Direct Borohydride Fuel Cell With Fecopc2-Catalysed Cathode, Jin-Fu Ma, Yan Liu, Jun-Hua Lai, Yong-Ning Liu Aug 2009

A Direct Borohydride Fuel Cell With Fecopc2-Catalysed Cathode, Jin-Fu Ma, Yan Liu, Jun-Hua Lai, Yong-Ning Liu

Journal of Electrochemistry

In this paper,a membraneless direct borohydride fuel cell was investigated. Cyclic voltammograms of FeCoPc2-modified glassy carbon electrode in the alkaline solution show that FeCoPc2 was active for oxygen reduction reaction. In addition, the steady-state polarization curve tests indicate that FeCoPc2 had better activity than FePc,CoPc or FePc+CoPc, which is due to its conjugated effect and synergistic effect of Fe and Co. Finally, a maximum power density of 110 mW/cm2 was attained, and the 25-day life test shows that the direct borohydride fuel cell had a good stability.

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Simultaneous Determination Of Uric Acid(Ua) And Ascorbic Acid(Aa) At Pca/Gc Electrode, Ren Wang, Ying Zhang, Jie Ding Aug 2009

Simultaneous Determination Of Uric Acid(Ua) And Ascorbic Acid(Aa) At Pca/Gc Electrode, Ren Wang, Ying Zhang, Jie Ding

Journal of Electrochemistry

Poly(cinnamic acid)-modified electrode (PCA /GC) was prepared by potentiostatic technique and was used for determination of uric acid (UA),ascorbic acid (AA),and their mixture by cyclic voltammetry. This modified electrode exhibited a potent and persistent electron-mediating behavior followed by well-separated oxidation peaks toward UA and AA at a scan rate of 50 mV·s-1 with a potential difference of 280 mV,which is large enough to determine UA and AA individually and simultaneously. The catalytic peak current obtained was linearly dependent on the UA and AA concentrations in the range of 2.0×10-6~1.0×10-4 mol·L-1,2.0×10-5~6.0×10-4 mol·L …

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