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2008

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Articles 1 - 30 of 138

Full-Text Articles in Engineering Science and Materials

Dynamic Design Guidelines For Prestressed Concrete Sleepers, Alexander Remennikov, Martin H. Murray, Sakdirat Kaewunruen Dec 2008

Dynamic Design Guidelines For Prestressed Concrete Sleepers, Alexander Remennikov, Martin H. Murray, Sakdirat Kaewunruen

Faculty of Engineering - Papers (Archive)

Current design philosophy, outlined in AS 1085.14, is based on the analysis of permissible stresses resulting from quasi-static wheel loads and essentially the static response of concrete sleepers. In general, cracking can incur when the bottom fibre stress is larger than tensile strength of concrete. Premature cracking of prestressed concrete sleepers has been detected in railway tracks. The major cause of cracking is the infrequent but high-magnitude wheel loads produced by a small percentage of “out-of-round” wheels or railhead surface defects, which are crudely accounted for in AS 1085.14 by a single load factor. Based on the current design method, …

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Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash Dec 2008

Modeling And Control Of Piezoactive Micro And Nano Systems, Saeid Bashash

All Dissertations

Piezoelectrically-driven (piezoactive) systems such as nanopositioning platforms, scanning probe microscopes, and nanomechanical cantilever probes are advantageous devices enabling molecular-level imaging, manipulation, and characterization in disciplines ranging from materials science to physics and biology. Such emerging applications require precise modeling, control and manipulation of objects, components and subsystems ranging in sizes from few nanometers to micrometers. This dissertation presents a comprehensive modeling and control framework for piezoactive micro and nano systems utilized in various applications.
The development of a precise memory-based hysteresis model for feedforward tracking as well as a Lyapunov-based robust-adaptive controller for feedback tracking control of nanopositioning stages are …

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Modeling, Analysis And Control Of Flexible Solid-State Hysteretic Actuators, Kushan Vora Dec 2008

Modeling, Analysis And Control Of Flexible Solid-State Hysteretic Actuators, Kushan Vora

All Theses

A distributed parameters modeling and control framework for flexible solid-state hysteretic actuator is presented in this work. For the simplicity of analysis, the actuator dynamic behavior is decoupled and treated separately from the hysteresis nonlinearity. To include the effects of widely-used flexural mechanisms, a mass-spring-damper boundary condition is considered for system. Moreover, the effect of electromechanical actuation is included as a concentrate force at the boundary. The problem is then divided into two parts: first part deals with free motion analysis of system in order to obtain eigenvalues and eigenfunctions using the expansion theorem and a standard eigenvalue problem procedure. …

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Finite Element Analysis Of Carbon Fiber Composite Ripping Using Abaqus, Joy Pederson Dec 2008

Finite Element Analysis Of Carbon Fiber Composite Ripping Using Abaqus, Joy Pederson

All Theses

An energy dissipation system is proposed for use on consumer passenger automotive vehicles and auto racing stock cars. This system will be utilized to protect the occupants from frontal impacts with stationary or near stationary objects. The system will be affixed to the front of the car's primary structure. It is proposed to replace the traditional steel bumper currently in use. This system will not increase the weight of the car, nor will it adversely affect the aerodynamics of the body. The system will improve the crashworthiness of the vehicle. Advanced composites will be the primary sacrificial element in the …

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Nonlinear Finite Element Analysis Of Tweel Geometric Parameter Modifications On Spoke Dynamics During High Speed Rolling, Maya Ramachandran Dec 2008

Nonlinear Finite Element Analysis Of Tweel Geometric Parameter Modifications On Spoke Dynamics During High Speed Rolling, Maya Ramachandran

All Theses

The acoustic signature and noise produced by non-pnuematic wheels such as the Michelin TWEELTM is a critical design criteria for automotive and other mobility applications. The TWEELTM structure consists of three basic parts: (1) a circular deformable 'shear beam', (2) collapsible spokes and (3) a rigid hub. During high speed rolling the TWEELTM produces acoustic noise which is hypothesized to be due to resonant vibration of the TWEELTM spokes as they enter the contact region, buckle and then snap back into a state of tension. In order to identify and help understand the causes of acoustic noise for a rolling …

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An Investigation On Spot-Weld Modeling Complexity For Crash Simulation, Srinivasan Vimalanathan Dec 2008

An Investigation On Spot-Weld Modeling Complexity For Crash Simulation, Srinivasan Vimalanathan

All Theses

In order to design car body structures which are safe during crash, modern automotive manufacturers perform both full-scale experimental crash tests and computer simulation of vehicle crash events using commercially available Finite Element Analysis (FEA) packages such as ABAQUS or LS-DYNA. Use of crash simulations significantly reduces the number of real time crash experiments needed and reduces the time required for design changes. However, in order to capture accurately crash behavior during high-speed impact, a large amount of detailed FEA modeling features such as number and types of elements, mesh element size, number of components, different types of connectors, material …

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Computational Analysis Of Input-Shaping Control Of Microelectromechanical Mirrors, Thomas Starling Dec 2008

Computational Analysis Of Input-Shaping Control Of Microelectromechanical Mirrors, Thomas Starling

All Theses

Advances in micromachining technology have enabled the design and development of high performance microelectromechanical systems (MEMS). There is a pressing need for control techniques that can be used to improve the dynamic behavior of MEMS such as the response speed and precision. In MEMS applications, open-loop control is attractive as it computes a priori the required system input to achieve desired dynamic behavior without using feedback, thus eliminating the problems associated with closed-loop MEMS control. While the input-shaping control is attractive due to its simplicity, the effectiveness of this control approach depends on the accuracy of the model that is …

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Computional Modeling Of Precision Molding Of Aspheric Glass Optics, Balajee Ananthasayanam Dec 2008

Computional Modeling Of Precision Molding Of Aspheric Glass Optics, Balajee Ananthasayanam

All Dissertations

In this dissertation, research in two parallel directions is presented; the first involves the prediction of the final size and shape of a glass lens during a precision glass lens molding process and the second introduces a method to compute and quantify the importance of higher order terms in fracture mechanics for different modes of fracture.
The process of precision lens molding has received attention in recent years due to its potential to mass produce aspherical lenses. Aspherical lenses have significantly better optical properties and conventional lens making techniques are limited to manufacturing of spherical lenses only. The conventional technique …

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Independent Torque Distribution Management Systems For Vehicle Stability Control, Indrasen Karogal Dec 2008

Independent Torque Distribution Management Systems For Vehicle Stability Control, Indrasen Karogal

All Theses

Vehicle Dynamics Control (VDC) systems, also called Electronic Stability Control (ESC) systems, are active on-board safety systems intended to stabilize the dynamics of vehicle lateral motion. In so doing, these systems reduce the possibility of the driver's loss of control of the vehicle in some critical or aggressive maneuvers. One approach to vehicle dynamics control is the use of appropriate drive torque distribution to the wheels of the vehicle. This thesis focuses on particular torque distribution management systems suitable for vehicles with independently driven wheels.
In conducting this study, a non-linear seven degree-of-freedom vehicle model incorporating a non-linear tire model …

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Flexography Printing Of Silver Based Conductive Inks On Packaging Substrates, Ramesh Chandra Kattumenu Dec 2008

Flexography Printing Of Silver Based Conductive Inks On Packaging Substrates, Ramesh Chandra Kattumenu

Dissertations

Printing technologies for the production of flexible electronics have gained much interest due to its potential as a means to reduce the complexity and costs of present technology. High volume printing techniques like flexography are of great importance in order to produce rolls of flexible electronics printed directly on paper substrates. The proposed research will be focused on RFID components being in-line printed using flexography printing as the manufacturing platform. The properties of substrates and inks and printing process parameters are evaluated to study their effect on printed traces and RFID antenna. It was found in the study that properties …

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Combustion Product Characterization Of The Iron-Heated Powders In Thermal Batteries, Jin Chong, Xue-Ping Gao, Ji-Qiang Wang Nov 2008

Combustion Product Characterization Of The Iron-Heated Powders In Thermal Batteries, Jin Chong, Xue-Ping Gao, Ji-Qiang Wang

Journal of Electrochemistry

The combustion products of thermal battery used iron-heated powders have been studied.It is identified by X-ray diffraction(XRD) analysis that the main compositions of the combustion products are Fe、FeO and KCl.The transmission electron microscopy(TEM) shows a typical core-shell structure with un-reacted Fe particle core coated by FeO shell with a shell thickness of around 200 nm.The combusted iron-heated powders exhibit no metal property,which is contrast to previous assumption.Further measurement indicates that at the ambient temperature the combustion products show semiconductor property of the p-type with conductivity in the order of 103 S·cm-1,which is five order lower than that of the iron …

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Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang Nov 2008

Studies Of Surface Diffusion In Pemfc Electrodes, Jiang-Shui Luo, Jian Chen, Bao-Lian Yi, Chuan-Sin Cha, Hua-Min Zhang

Journal of Electrochemistry

A PEMFC electrode consisting of dual-layer catalyst layer(CL) was fabricated in this work.The outer CL was Nafion-free,while the inner CL was Nafion-bonded.The effects of Pt/C catalyst in the outer CL that did not contact with Nafion on the current generation in PEMFC electrodes were investigated.Cyclic voltammetric studies indicated that the Pt/C catalyst in the outer CL without direct contact with Nafion was still electrochemically active in taking part in the adsorption/desorption of hydrogen and the electrochemical oxidation/reduction of the oxygen-containing species occurring at the interface of "Pt/Nafion" in the inner CL.The polarization curves showed that the output voltage of the …

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High Performance Fuel Cell Catalyst And 5kw Pemfc Stack Without Humidification At Room Temperature And Atmosphere, Xin-Fa Hu, Min Chen, Shi-Jun Liao Nov 2008

High Performance Fuel Cell Catalyst And 5kw Pemfc Stack Without Humidification At Room Temperature And Atmosphere, Xin-Fa Hu, Min Chen, Shi-Jun Liao

Journal of Electrochemistry

The Pt/C catalyst with high dispersion and high performance was prepared successfully by an organic colloidal method and small batch production(10g) of Pt/C catalyst has been realized.The particle sizes of the active components in the catalyst could be as small as 2.8 nm and the active surface area was up to 450 m2/g.A high performance membrane-electrode assembly(MEA) with surface area of 275 cm2 has been prepared by using the home-made catalyst with a catalyst coated membrane method invented in the lab,and a 5 kW stack has been assembled.The stack showed working 10 h at room temperature,atmosphere and without humidification.

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Ceo_2/Pt Composite Electrodes And Their Catalytic Performance, Ying Fu, Zi-Dong Wei, Yong-Chao Feng, Xin-Li Ma, Ming-Jia Liao, Chao Liao, Jie Zhang, Huan Zhang Nov 2008

Ceo_2/Pt Composite Electrodes And Their Catalytic Performance, Ying Fu, Zi-Dong Wei, Yong-Chao Feng, Xin-Li Ma, Ming-Jia Liao, Chao Liao, Jie Zhang, Huan Zhang

Journal of Electrochemistry

In this paper,the cerium oxide(CeO2) nanoparticles were electrochemically deposited on a Pt electrode by potentiostatic deposition(psd) and potential pulse deposition(ppd) to form CeO2/Pt composite electrodes,CeO2/Pt(psd) and CeO2/Pt(ppd).The properties of the CeO2 were characterized by field emission scanning electron microscope(FESEM) and X-ray diffraction(XRD).The results showed that the CeO2 nanoparticles prepared by psd and ppd were homogeneous and dense.The methanol oxidation reaction(MOR) and oxygen reduction reaction(ORR) on the Pt electrode were enhanced with the introduction of CeO2 into Pt.In addition,the catalytic capability of the CeO2/Pt electrode can be further improved after dissolution of part of CeO2 on the composite electrode in H2SO4.The …

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Direct Electrochemistry Of Chloroperoxidase At Gc Electrode Modified With Swnts, Hong-Xia Zhang, Xia-Qin Wu, Wen-Jing Hou, Wen Xie, Zhong-Qing Lu, Rong Wang, He-Xing Li Nov 2008

Direct Electrochemistry Of Chloroperoxidase At Gc Electrode Modified With Swnts, Hong-Xia Zhang, Xia-Qin Wu, Wen-Jing Hou, Wen Xie, Zhong-Qing Lu, Rong Wang, He-Xing Li

Journal of Electrochemistry

The chloroperoxidase(CPO) was immobilized onto the surface of SWNTs modified electrodes.The electrochemical behaviors of modified electrode have been investigated by cyclic voltammetry.The appearance of a pair of well-defined redox peaks in the CV curve indicated that SWNTs can promote the electron transfer reaction of CPO.The results of cyclic voltammetry in PBS of different pH,from 3~9,showed that the reaction of CPO on the modified electrode was with equal numbers of electron and protein.This readily prepared SWNTs modified electrode showed excellent stability and good catalysis to O2.

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Synthesis Of The Lifepo_4 By Co Reduction:Reaction Mechanism And Kinetics, Yun-Hua Chen, Yong Yang Nov 2008

Synthesis Of The Lifepo_4 By Co Reduction:Reaction Mechanism And Kinetics, Yun-Hua Chen, Yong Yang

Journal of Electrochemistry

LiFePO4 cathode material was synthesized by CO reducing FePO4 and LiOH precursors.The structure,morphology and electrochemical performances of such LiFePO4 material were characterized by XRD,SEM and charge-discharge tests.It was shown that the particle size of the LiFePO4 synthesized with 5% excess of LiOH in the precursor was about 200 nm.By carbon coating,the LiFePO4 electrode was able to deliver a reversible capacity of 158 mAh·g-1 at 0.1C discharge rate.Temperature-programmed X-ray diffraction was employed to monitor the reaction during the formation of LiFePO4,and Li3Fe2(PO4)3 was found to be an intermediate by analyzing the time-resolved XRD patterns.Kinetic study indicates that nucleation and their growth …

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Ec-Pt/Cnts Glucose Oxidative Electrode, Jia-Hua Liang, Chun-Mei Zhou, Hong-Juan Wang Nov 2008

Ec-Pt/Cnts Glucose Oxidative Electrode, Jia-Hua Liang, Chun-Mei Zhou, Hong-Juan Wang

Journal of Electrochemistry

A glucose oxidative electrode(GOD),EC-Pt/CNTs glucose oxidative electrode,was constructed by ethyl cellulose(EC) and Pt/CNTs.The sensitivity of the EC-Pt/CNTs GOD is 0.85 μA/mM in the concentration range of 0～4 mmol/L of glucose.After dipped in PBS(4℃) for 18 days,the activity of the EC-Pt/CNTs GOD can reach 80%.It is promising for the EC-Pt/CNTs GOD to be used to construct glucose biosensor.

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The Hydrothermal Synthesis Of Nanoscale Lifepo_4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong Nov 2008

The Hydrothermal Synthesis Of Nanoscale Lifepo_4 And Its Electrochemical Performance, Si-Min Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode materials of nanosiged LiFePO4 were prepared by hydrothermal templating synthesis.The grain sizes and electrochemical performance of LiFePO4 were controlled by surfactant.It was shown that the grain sizes varied from less than a hundred to hundreds nanometers by the SEM images.In the charge/discharge tests,the discharge capacities of the sample as a lithium ion battery were achieved to 150 mAh/g at 0.1C,140 mAh/g at 1C,and 126 mAh/g at 2C,with good cycling performance.

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Fabrication Of Superhydrophilic Aluminum Oxide Through Single-Step Anodic Oxidation, Qin Zhang, Qi-Ming Yin, Jia-Ming Ye, Yuan-Rong Zhu Nov 2008

Fabrication Of Superhydrophilic Aluminum Oxide Through Single-Step Anodic Oxidation, Qin Zhang, Qi-Ming Yin, Jia-Ming Ye, Yuan-Rong Zhu

Journal of Electrochemistry

Hydrophilic aluminum oxide is popularly used for heat exchanger of air-condition.Herein,we developed a simple method to prepare superhydrophilic aluminum oxide on the surface of aluminum through single-step electrochemical oxidization.The morphologies and water contact angles on surfaces of alumina fabricated under different electrochemical conditions were investgated.Superhydrophilic surfaces fabricated by this method have good stability and high mechanical strength with water contact angle almost 0°.Coated with low surface energy materials,superhydrophilc alumina will be converted to superhydrophobic.

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Primary Study Of Tiron As Active Materials For The Redox Flow Battery, Yan Xu, Yue-Hua Wen, Jie Cheng, Yu-Sheng Yang, Zi-Li Xie Nov 2008

Primary Study Of Tiron As Active Materials For The Redox Flow Battery, Yan Xu, Yue-Hua Wen, Jie Cheng, Yu-Sheng Yang, Zi-Li Xie

Journal of Electrochemistry

Effects of solution pH on the electrochemical behavior of tiron(sodium 4,5-dihydroxy-1,3-benzendisulfonic) couple(on a graphite electrode) were studied by cyclic voltammetry in aqueous solutions.It is shown that at pH<4,tiron exhibited a redox process at a relatively high potential with a good reversibility.A redox flow battery was formed employing tiron as the positive active species and V(III)/V(II) as the negative redox couple.In sulfuric acid medium,the coulombic efficiency of the tiron-V redox flow cell was more than 90% with a good cycle life.The decay in the cycle performance was minimal.Therefore,the feasibility of tiron as active materials for redox flow battery application is demonstrated.

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Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang Nov 2008

Preparation And Electrocatalystic Performance Of Ir/C Catalyst For Ammonia Oxidation, Qing-Mei Kong, Yi-Ping Han, Ling-Juan Deng, Tian-Hong Lu, Ya-Wen Tang

Journal of Electrochemistry

The Ir/C catalyst with 30%(by mass) Ir was prepared in the CH3CH2OH and H2O binary system.The X-ray diffraction(XRD) data showed that the average sizes of the Ir particles in the Ir/C catalyst was about 2.2 nm.The results of the electrochemical measurements indicated that the electrocatalytic activity of the Ir/C catalyst for the ammonia oxidation in the neutral NaClO4 solution was similar to the Ir catalyst,while electrocatalytic stability was much better than that of the Ir catalyst.Furthermore,the peak current density of the ammonia oxidation at the Ir/C catalyst electrode showed a good linear relationship with the ammonia concentration,illustrating that the Ir/C …

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Preparations Of Composite Electrodes Of Pt With H_Xwo_3 And Catalytic Activity Toward Oxygen Reduction Reaction, Pan-Pan Guo, You-Ju Huang, Hong-Yan Yang, Wei Li, Qing-Long Zhang, Wei-Shan Li Nov 2008

Preparations Of Composite Electrodes Of Pt With H_Xwo_3 And Catalytic Activity Toward Oxygen Reduction Reaction, Pan-Pan Guo, You-Ju Huang, Hong-Yan Yang, Wei Li, Qing-Long Zhang, Wei-Shan Li

Journal of Electrochemistry

Three composite electrodes of platinum with hydrogen tungsten bronze(HxWO3)were prepared by voltammetry: hydrogen tungsten bronze deposited on platinum(HxWO3/Pt);platinum deposited on hydrogen tungsten bronze(Pt/HxWO3) and codeposited platinum and hydrogen tungsten bronze(Pt-HxWO3).The eletro-catalytic activities of three electrodes toward oxygen reduction reaction were studied.It is found that the catalytic activity of platinum can be improved by introducing with hydrogen tungsten bronze.Among these composite electrodes Pt/HxWO3,and the electrode shows the best eletro-catalytic activity toward oxygen reduction reaction,hence,provides a new way for reducing loading of noble metal in the application for fuel cell.

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Corrosion Inhibition Of Magnesium Alloy In 3.5% Nacl Medium By Tungstate, Ling-Jie Li, Zhi-Ming Yao, Jing-Lei Lei, Dong-Hai He, Sheng-Tao Zhang, Fu-Sheng Pan Nov 2008

Corrosion Inhibition Of Magnesium Alloy In 3.5% Nacl Medium By Tungstate, Ling-Jie Li, Zhi-Ming Yao, Jing-Lei Lei, Dong-Hai He, Sheng-Tao Zhang, Fu-Sheng Pan

Journal of Electrochemistry

Electrochemical impedance spectroscopy(EIS),Tafel polarization curves and scanning electron microscopy(SEM) were used to study the corrosion inhibition of AZ61 magnesium alloy in 3.5% NaCl medium with tungstate.Results showed that tungstate demonstrates strong inhibition to the corrosion of AZ61 magnesium alloy.At the concentration of 0.01 mol/L,tungstate has a high inhibition efficiency 75.5%.Tungstate is an anodic inhibitor that mainly inhibited the anodic reactions of magnesium alloy through forming a compact protective layer that covered the magnesium alloy surface active sites.

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Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang Nov 2008

Behavior Of Copper Electrodeposition In Copper Electroplating Solution With Different Peg Molecular Weight, Lie Yin, Zeng-Lin Wang

Journal of Electrochemistry

The effect of the polyethylene glycol(PEG) molecular weight(MW) upon via-hole filling with diameter of 50 μm and aspect ratio of 1 in the acid copper plating solution was studied.The cathodic polarization in copper electroplating bath with PEG of different molecule weights was investigated by linear sweep voltammetry.The surface roughness,crystallography,and the resistivity of copper films were characterized by X-ray diffraction(XRD),atomic force microscopy(AFM) and the four-point probe measurements.The results showed that the polarization on the cathode and the hole-filling capability of electroplating copper bath were increased evidently with an increase of PEG molecular weight from 600 to 8000.When the PEG MW was …

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Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu Nov 2008

Voltammetric Determination Of Iodate Ion In Table Salt By Carboxylic Carbon Nanotubes Modified Carbon Paste Electrode, Jun-Hua Li, Fu-Xing Zhang, Jian-Qiu Wang, Zhi-Feng Xu, Rong-Ying Zeng, Yan Yu

Journal of Electrochemistry

A highly-sensitive and mercury-free method of determining iodate ion in table salt was established based on carboxylic carbon nanotubes modified carbon paste electrode.In 0.1 mol/L NaOH solution,there was a sensitive cathodic stripping peak on voltammograms.The stripping peak potential was-0.52 V when accumulation time of IO-3 at the modified electrode was 60 s and the potential scan rate was 300 mV/s.There was a good liner relationship between the peak current and IO-3 concentration in the range of 8.0×10-10 ～ 5.0×10-8 mol/L and 1.0×10-7 ～ 3.0×10-6 mol/L with the correlation coefficient of 0.999 and 0.998,respectively.The detection limit was 1.0 × 10-11 mol/L.This …

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Electrochemical Behavior And Determination Of Paracetamol On Activated Glassy Carbon Electrode, Bao-Yu Tan, Fang Liao, Xiao-Ying He, Qing-Tao Zhu, Jun Hua, Xiao-Li Jiang Nov 2008

Electrochemical Behavior And Determination Of Paracetamol On Activated Glassy Carbon Electrode, Bao-Yu Tan, Fang Liao, Xiao-Ying He, Qing-Tao Zhu, Jun Hua, Xiao-Li Jiang

Journal of Electrochemistry

The electrochemical behavior of paracetamol(PCT) was studied at glassy carbon electrode activated by cyclic voltammetry.In HAc-NaAc buffer solution(pH=4.00),a couple of sensitive redox peaks were recorded about 0.54 V in the cyclic voltammograms.The result indicated that the process was controlled by adsorption and nearly reversible.The reaction electron and proton numbers were estimated,respectively,to be two.Excllent linearity was observed in the correlation between the oxidation peak current and the concentration of PCT in the range of 8.00×10-6～2.00×10-4 mol·L-1.The correlative coefficient was-0.999 18.The detection limit was 6.34×10-6 mol·L-1.This method can be used for the determination of PCT real samples.

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Voltammetric Determination Of L-Cysteine At Bipyrine Bridged Copper(Ⅱ) Complex Modified Glassy Carbon Electrode, Ming-Yan Wang, Fan Yang, Sheng-Yu Zhang, Xing-You Xu, Xu-Jie Yang Nov 2008

Voltammetric Determination Of L-Cysteine At Bipyrine Bridged Copper(Ⅱ) Complex Modified Glassy Carbon Electrode, Ming-Yan Wang, Fan Yang, Sheng-Yu Zhang, Xing-You Xu, Xu-Jie Yang

Journal of Electrochemistry

A modified electrode has been constructed by depositing a novel copper(Ⅱ) complex 2biPy(ClO4)4 on the glassy carbon electrode through the method of cyclic voltammetry(CV).It was found that the modified electrode exhibited high electrocatalytic activity toward L-Cysteine oxidation with good reproducibility and high sensitivity.The peak current of semi-derivative linear scan was proportional to the concentration of L-cys in the range of 1×10-6～3×10-4 mol·L-1.The detection limit was 5×10-7 mol·L-1.

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Hand-Held Flyback Driven Coaxial Dielectric Barrier Discharge: Development And Characterization, Victor J. Law, Vladimir Milosavljevic, Neil O’Connor, James F. Lalor, Steven Daniels Sep 2008

Hand-Held Flyback Driven Coaxial Dielectric Barrier Discharge: Development And Characterization, Victor J. Law, Vladimir Milosavljevic, Neil O’Connor, James F. Lalor, Steven Daniels

Articles

The development of a handheld single and triple chamber atmospheric pressure coaxial dielectric barrier discharge driven by Flyback circuitry for helium and argon discharges is described. The Flyback uses external metal-oxide-semiconductor field-effect transistor power switching technology and the transformer operates in the continuous current mode to convert a continuous dc power of 10–33 W to generate a 1.2–1.6 kV 3.5 μs pulse. An argon discharge breakdown voltage of ∼768 V is measured. With a 50 kHz, pulse repetition rate and an argon flow rate of 0.5–10 argon slm (slm denotes standard liters per minute), the electrical power density deposited in …

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A Novel Method Characterizing The Impact Response Of Functionally Graded Plates, Reid A. Larson Sep 2008

A Novel Method Characterizing The Impact Response Of Functionally Graded Plates, Reid A. Larson

Theses and Dissertations

Functionally graded material (FGM) plates are advanced composites with properties that vary continuously through the thickness of the plate. Metal-ceramic FGM plates have been proposed for use in thermal protection systems where a metal-rich interior surface of the plate gradually transitions to a ceramic-rich exterior surface of the plate. The ability of FGMs to resist impact loads must be demonstrated before using them in high-temperature environments in service. This dissertation presents a novel technique by which the impact response of FGM plates is characterized for low-velocity, low- to medium-energy impact loads. An experiment was designed where strain histories in FGM …

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Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, And The Impact On Fuel Economy, Dean Rotenberg Sep 2008

Ultracapacitor Assisted Powertrains: Modeling, Control, Sizing, And The Impact On Fuel Economy, Dean Rotenberg

All Theses

This thesis investigates possible fuel economy gains attainable by a combination of high-power density ultracapacitors (also called supercapacitors) and an induction motor integrated into a conventional vehicle powertrain for power assistance.
Periods of quick acceleration require a much higher power output from an automobile than what is encountered under more typical driving conditions. A simple kinetic energy calculation can show that accelerating a 2000 kg vehicle (roughly the size of a Ford Explorer SUV) from 0 to 60 mph in 10 seconds requires almost 70 kW of power, in addition to the power needed to overcome road and air drag …

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