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Articles 4051 - 4080 of 5701

Full-Text Articles in Engineering

Influence Of Ions Dimension On The Electric Field Activation Of Micro-Crystallite Carbon, Gang-Wei Sun, Wen-Hua Song, Guo Cheng, Wen-Ming Qiao, Li-Cheng Ling May 2010

Influence Of Ions Dimension On The Electric Field Activation Of Micro-Crystallite Carbon, Gang-Wei Sun, Wen-Hua Song, Guo Cheng, Wen-Ming Qiao, Li-Cheng Ling

Journal of Electrochemistry

Micro-crystallite carbon (CC) was synthesized by KOH activation of carbonized petroleum coke precursors. The porous properties structure and crystallite structure were characterized by N2 adsorption-desorption, X-ray diffraction (XRD) measurements. The capacitive behavior of CC was investigated in the electrolyte of Et4NBF4/PC, Et4NBF4/AN, Bu4NBF4/PC and Bu4NBF4/AN, respectively. Results showed that the lower potential of electric field activation (EFA) was obtained in the solvent of AN than in PC, which was ascribed to the fact that smaller solvated ions dimension in AN facilitating the intercalation …


Electrochemical Behaviors Of Hydrazine In Bmimpf6 Solution At Ag Electrode, Jie Sun, Yan Li, Yi-Ling Feng, Rong Wang, Xia-Qin Wu May 2010

Electrochemical Behaviors Of Hydrazine In Bmimpf6 Solution At Ag Electrode, Jie Sun, Yan Li, Yi-Ling Feng, Rong Wang, Xia-Qin Wu

Journal of Electrochemistry

In this work, the electrochemical behaviors of hydrazine at Ag electrode in the room temperature ionic liquid, BmimPF6, were studied by cyclic voltammetry. Results suggested that Ag electrode showed a good catalytic activity towards hydrazine oxidation. The catalytic peak current showed a good linear relationship with the hydrazine concentration in the range of 0 ~ 3.4 mmol/L. The rate-determining step of the electrocatalytic reaction involved one electron transfer form hydrazine molecule to Ag+ ion.


Hydrogen Evolution Reaction Activtity Of Ni-Ru-Ir Oxide Cathode Coating, Yin-Hui Fu, Xue-Ming Li, Wu-Lin Li, Jun Zhang May 2010

Hydrogen Evolution Reaction Activtity Of Ni-Ru-Ir Oxide Cathode Coating, Yin-Hui Fu, Xue-Ming Li, Wu-Lin Li, Jun Zhang

Journal of Electrochemistry

The Ni-Ru-Ir electrode coating was fabricated by thermal decomposition and oxidation. Electrochemical properties of Ni-Ru-Ir electrode coating and pure nickel cathode in the 30% NaOH solutions at 90 ℃(conditions of the industrial electrolysis) ,have been investigated by cyclic voltammetry,Tafel curves and chronoamperometry. The results show that the Ni-Ru-Ir oxide electrode coating exhibited high catalytic activity. At the current density of 0. 3 A·cm-2,the lowest hydrogen evolution overpotential of Ni-Ru-Ir oxide electrode coating was about 300 mV lower than Ni. The roughness and excharge current density of Ni-Ru-Ir electrode coating were 32 and 4 times,respectively,larger than those of pure …


Synthesis And Electrochemical Properties Of Li3V2(Po4)3/C Cathode Materials For Lithium Ion Battery, Li-Ying Liu, Hai-Yan Zhang, Lian Chen, Yu-Chun Zhai May 2010

Synthesis And Electrochemical Properties Of Li3V2(Po4)3/C Cathode Materials For Lithium Ion Battery, Li-Ying Liu, Hai-Yan Zhang, Lian Chen, Yu-Chun Zhai

Journal of Electrochemistry

Cathode material Li3V2(PO4) 3 /C for Lithium-ion battery was synthesized by combination of ball milling and baking. Physical and electrochemical performances of as-prepared materials were characterized through XRD,EIS and galvanostatic cell cycling. The results show that the products were monoclinic Li3 V2 (PO4) 3 with well-developed crystal structure. At 0. 1C,0. 25C and 0. 5C,the initial discharge capacities were 150. 6,134. 1 and 107. 1 mAh·g-1 ,respectively. Capacity retention rates were 87. 3% after 130 cycles at 0. 25C and 87. 2% after 105 cycles at 0. 5C. Charge-discharge …


Nano-Sized Au On Nickel Foam As Cathode Of Alkaline Al-H2O2 Semi Fuel Cell, Shu-Li Chen, Bang-An Lu, Yao Liu, Gui-Ling Wang, Dian-Xue Cao May 2010

Nano-Sized Au On Nickel Foam As Cathode Of Alkaline Al-H2O2 Semi Fuel Cell, Shu-Li Chen, Bang-An Lu, Yao Liu, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

Nano-sized Au particles were deposited on a nickel foam substrate by a fast spontaneous deposition method using AuCl3 as the source of Au. The effects of AuCl3 concentration and deposition time on the size and distribution of Au particles,and the performance of the obtained Au/Ni electrode as the cathode of Al-H2O2 semi fuel cell were investigated. It was found that after the nickel foam was immersed in a 2 mmol·L-1 AuCl3 solution for 60 s,Au particles with diameters smaller than 100 nm were deposited on its surfaces and cover the surface completely. The …


Electrokinetic Manipulation Of Particles And Cells In Microfluidic Devices, Christopher Church May 2010

Electrokinetic Manipulation Of Particles And Cells In Microfluidic Devices, Christopher Church

All Theses

With the recent advancement in micro-fabrication technology, lab-on-a-chip devices have been developed in order to perform biological analysis through cell manipulation. Microchannels used in these lab-on-a-chip devices have been demonstrated to accurately perform many different cell manipulation techniques such as focusing, separation, trapping, and lysis. Although there are many methods available for these techniques, electrokinetics has been rapidly gaining popularity due to the simplicity of application and removal of the need for in channel micro-structures. This thesis studies the use of electrokinetic flow and accompanying phenomena in various structured microchannels to perform focusing, separation, trapping, and lysis of cells. Three …


Modeling Of A Porous Metal Foam Cryogenic Counter Flow Heat Exchanger, Craig Fortier May 2010

Modeling Of A Porous Metal Foam Cryogenic Counter Flow Heat Exchanger, Craig Fortier

All Theses

This thesis involves the modeling of cryogenic fluids through a porous metal foam counter flow heat exchanger. Although much research has been completed involving light weight high porosity metal foams in recent years, research performed on the subject of mid range porosities in metal foams and their use in heat exchangers has been relatively untouched. Even less literature is available pertaining to the effects of cryogenic fluids in porous metal foams.
Much about heat exchanger performance and pressure drop depends on the structure and relative density of the metal foams. This has been elaborated in several sources, but only for …


Mechanical Milling Of Co-Rich Melt-Spun Sm-Co Alloys, Farhad Reza Golkar-Fard May 2010

Mechanical Milling Of Co-Rich Melt-Spun Sm-Co Alloys, Farhad Reza Golkar-Fard

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Rare-earth, high-energy permanent magnets are currently the best performing permanent magnets used today. The discovery of single domain magnetism in 1950’s ultimately led to the development of nanocomposite magnets which had superior magnetic properties. Previous work has shown that mechanical milling (MM) effectively generates nanoscale structures in Sm-Co-based alloys. MM of more Co-rich, melt-spun Sm-Co alloys (up to the eutectic composition) and the role of initial structure on the milling behavior were investigated.

Sm-Co alloys with compositions of Sm10.5Co89.5 and Sm8Co92 were produced by arc melting, melt-spinning and mechanical milling. X-ray diffraction results showed …


Coupled Dem-Fem For Dynamic Analysis Of Granular Systems In Bending, Kitti Rattanadit May 2010

Coupled Dem-Fem For Dynamic Analysis Of Granular Systems In Bending, Kitti Rattanadit

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Characterizing the dynamic behavior of granular materials is one of the great challenges in the mechanics of granular matter. Methods for evaluating the mechanical properties of granular matter have applications in a variety of industries, mining and geotechnical activities, defense and military operations. A coupled 2D Discrete Element Method-Finite Element Method (DEM-FEM) code, called "BobKit", is developed and implemented for analyzing the behavior of a 2D granular layer on top of an elastic beam under deforming (quasi-static) or vibrating (dynamic) of the beam. The explicit time-integration dynamic code is used to simulate quasi-static and dynamic bending of the granular layer …


Re-Engineering A Trash/Recycling Collection Vehicle Based On Challenging Customer Requirements, Edward Smith May 2010

Re-Engineering A Trash/Recycling Collection Vehicle Based On Challenging Customer Requirements, Edward Smith

All Theses

Engineering design starts with the definition of design requirements. These requirements define the design problem and must be satisfied for a solution to be acceptable. While many design methodologies exist for defining design requirements, none presently provides a systematic approach for designers to challenge requirements. Yet, Pahl and Beitz, Hazelrigg, and Suh all argue that a designer should continually question the need for each requirement and refine them as the product evolves. Thus, there exists a need to develop a comprehensive method that enables a designer to verify, review/question, and revise requirements throughout the design process. This research uses the …


System Modeling And Power Management Strategy For A Series Hydraulic Hybrid Vehicle, Sisay Molla May 2010

System Modeling And Power Management Strategy For A Series Hydraulic Hybrid Vehicle, Sisay Molla

All Theses

A hydraulic hybrid vehicle draws propulsion power from an internal combustion engine as its prime mover and a gas-charged hydro-pneumatic accumulator as its energy buffer. The accumulator serves the purposes of storing regenerated braking energy and supplementing engine power as determined by an on-board power management strategy. In the configuration known as a series hydraulic hybrid powertrain, the engine is mechanically decoupled from the vehicle's wheels thereby offering excellent opportunities for maximizing energy efficiency and reducing pollutant emissions.
This thesis dealt with the development of a causally interconnected, non-linear, dynamic model of a series hydraulic hybrid powertrain featuring independently controllable …


Vehicle Steering Systems - Hardware-In-The-Loop Simulator, Driving Preferences, And Vehicle Intervention, Jesse Black May 2010

Vehicle Steering Systems - Hardware-In-The-Loop Simulator, Driving Preferences, And Vehicle Intervention, Jesse Black

All Dissertations

The steering system is a critical component of all ground vehicles regardless of their propulsion source. Chassis directional control is provided by the steering system, which in turn relays valuable feedback about the road and vehicle behavior. As the primary feedback channel to the driver, the steering system also delivers the initial perception of a vehicle's handling and responsiveness to the consumer. Consequently, the steering system is an important aspect of the vehicle's evaluation and purchasing process, even if drivers are unaware of its direct influence in their decision making. With automobile purchases potentially hinging on the steering system, a …


Comprehensive Analysis Of A Student-Centered Active-Learning Integrated Statics And Dynamics Course For Mechanical Engineers, Marisa Orr May 2010

Comprehensive Analysis Of A Student-Centered Active-Learning Integrated Statics And Dynamics Course For Mechanical Engineers, Marisa Orr

All Theses

The Student-Centered Active Learning in Undergraduate Programs (SCALE-UP) approach to instructional design was adapted with the goal of delivering more effective statics, dynamics and multivariate calculus instruction and integrated course curricula. Inquiry-based learning exercises were designed, incorporating material from statics and dynamics into multivariable calculus, and vice-versa, as well as integrating statics and dynamics into one course. Analysis included an exploration of student study habits, multiple measures of course effectiveness, and an examination of curricular effects. Challenges of implementation are also discussed.
Study habits of students in an integrated Statics and Dynamics course were assessed through a voluntary survey in …


A Proposed Method To Identify Requirements Significant To Mass Reduction, James Mclellan May 2010

A Proposed Method To Identify Requirements Significant To Mass Reduction, James Mclellan

All Theses

Reducing the mass of engineering products holds the potential for significant benefits by reducing material costs, environmental impact, transportation costs, and in the case of vehicles, reducing fuel consumption. While there are many approaches for reducing mass, analyzing requirements has the greatest potential since requirements definition is the earliest phase of product development, where the most design freedom exists. This thesis proposes a requirement analysis method that identifies requirements that impact significant amounts of mass. The research hypothesis is: Engineering requirements can be represented and processed in a systematic manner and linked to physical components and systems, thus enabling mass …


Interpretability Analysis Of Function Structures At Various Levels Of Abstraction: A User Study, Jonathan Thomas May 2010

Interpretability Analysis Of Function Structures At Various Levels Of Abstraction: A User Study, Jonathan Thomas

All Theses

Function models are used during the conceptual design phase of the design process to model the intended use or objective of a product, independent of the products physical form. Function models also aid in guiding design activities such as generating concepts and allocating design team resources. Recent research efforts have focused on the formalization of functional models through a controlled vocabulary and archival of functional representations in computer-based repositories. However, the usefulness and interpretability of these function models has not been rigorously evaluated.
This thesis presents the results of two controlled user studies to ascertain the interpretability of functional representations …


"Elementary" Engineering Experiences, Steven E. Butt, Tycho K. Fredericks Mar 2010

"Elementary" Engineering Experiences, Steven E. Butt, Tycho K. Fredericks

Academic Leadership Academy

Through early exposure to engineering, this program attempts to open the minds of children to future exciting opportunities that are accessible to them if they are appropriately prepared in mathematics and science. The program consists of a two to four hour session in which students, parents, and teachers are walked through a sequence of hands-on activities in various locations within the CEAS building. In addition to immersing the students in engaging activities, time is also invested in helping students understand who engineers are and what engineers do. This includes describing the various engineering disciplines, and their workplaces.


Processing A Nickel Nanostrand And Nickel Coated Carbon Fiber Filled Conductive Polyethylene By Injection Molding, David Anthony Whitworth Mar 2010

Processing A Nickel Nanostrand And Nickel Coated Carbon Fiber Filled Conductive Polyethylene By Injection Molding, David Anthony Whitworth

Theses and Dissertations

A new method for pre-impregnating nickel coated carbon fiber with a thermoplastic polymer to make towpreg, similar to a recently developed coating-line by João P. Nunes et al and a new electrically conductive thermoplastic are developed. A melted bath was used to help mitigate health concerns and waste for dispersion of nickel coated carbon fibers (NCF) in low density polyethylene (LDPE). This towpreg was then mixed with more LDPE or a mixture of LDPE and nickel nanostrands (NiNS) to a desired filler volume fraction to test the electrical conductivity of the composite. Some of these mixtures were then injection molded …


Me-Em Enewsbrief, March 2010, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University Mar 2010

Me-Em Enewsbrief, March 2010, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.


Self-Activating Safety Mechanisms For Li-Ion Batteries, Xin-Ping Ai, Yu-Liang Cao, Han-Xi Yang Feb 2010

Self-Activating Safety Mechanisms For Li-Ion Batteries, Xin-Ping Ai, Yu-Liang Cao, Han-Xi Yang

Journal of Electrochemistry

The safety concerns of LIBs are considered to be a main obstacle to their high rate or large capacity applications in electric vehicles.This paper describes briefly our research works on the development of self-activating safety mechanisms for LIBs,including redox shuttle,potential-sensitive separator,temperature-sensitive electrode,and fire-retardent electrolyte.The problems and future in this research area are also discussed.


The Synthesise Of Electron-Conducting Redox Hydrogel And Its Application In Microbial Fuel Cell, Kai-Peng Wang, Sheng-Li Chen Feb 2010

The Synthesise Of Electron-Conducting Redox Hydrogel And Its Application In Microbial Fuel Cell, Kai-Peng Wang, Sheng-Li Chen

Journal of Electrochemistry

Efficient electron transfer between the microbe and the anode is key for the electricity generation in Microbial fuel cell(MFC).Through the modification of anode,the rate of electron transfer can be accelerated,therefore the performance of MFC can be enhanced.In this paper,we report the synthesis of a type of electronconducting and bio-compatible redox hydrogel and its application.The hydrogel consists of poly(4-vinylpyridine) as backbone and neutral red as the redox center.By immobiliazing neutral red on the backbone through covalent bond,the secondary contamination due to the soluble redox mediator to external environment can be prevented.MFCs using the hydrogel-modified carbon anode significantly exhibit shorter acclimation period,and …


Effects Of Different Carbon Sources On Performance Of Li3V2(Po4)3/C Composite Cathode Materials, Kai-Yuan Liu, Jian-Shu Huang, Li Yang Feb 2010

Effects Of Different Carbon Sources On Performance Of Li3V2(Po4)3/C Composite Cathode Materials, Kai-Yuan Liu, Jian-Shu Huang, Li Yang

Journal of Electrochemistry

The monoclinic Li3V2(PO4)3 cathode materials were prepared by carbothermal reduction method,with methyl cellulose, chitosan(crab shells) or glucose anhydrous as carbon sources, respectively.The crystal structures, morphologies and the electrochemical performances were characterized by XRD, SEM and electrochemical measurement. The XRD patterns show that the samples obtained at 800 ℃ for 6 h have a pure monoclinic structure,which indicates that the carbon exists in amorphous phase. Electrochemical measurements show that the difference of carbon sources has a significant influence on the electrochemical properties of the materials. The Li3V2(PO4)3 …


Performance Of Sulfur-Super Conductive Carbon Black Composite In Electrolyte Mixed With Room Temperature Ionic Liquid, Bo Zhang, Si-Ting Chen, Xue-Ping Gao Feb 2010

Performance Of Sulfur-Super Conductive Carbon Black Composite In Electrolyte Mixed With Room Temperature Ionic Liquid, Bo Zhang, Si-Ting Chen, Xue-Ping Gao

Journal of Electrochemistry

The sulfur-super conductive carbon black composite was prepared as cathode material of lithium/sulfur battery.The composite was characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),and electrochemical impedance spectroscopy(EIS).The sulfur composite shows a high discharge capacity and a good cycle performance in electrolyte mixed with 50% of room temperature ionic liquid.In particular,the discharge capacity of the composite was stabilized at 483.6 mAh/g after 50 cycles.


Electrochemical Properties Of Ni(Oh)2 Doped By Nio, Fei-Biao Chen, Bo-Rong Wu, Wei-Feng An, Zhao-Jun Yang, Feng Wu, Shi Chen Feb 2010

Electrochemical Properties Of Ni(Oh)2 Doped By Nio, Fei-Biao Chen, Bo-Rong Wu, Wei-Feng An, Zhao-Jun Yang, Feng Wu, Shi Chen

Journal of Electrochemistry

The Ni(OH)2 cathode material of MH/Ni was doped by NiO,which behaves as a capacitor and can improve the charge-discharge rate capacity of Ni(OH)2.The electrochemical properties of Ni(OH)2 was characterized by charge-discharge curves and cyclic voltammetry.The results showed that the material had the best discharge property when doped by 5% NiO,and the discharge specific capacity could reach 310.1 mAh/g at 0.2 C rate and remianed 79.5% at 3 C rate.The difference oxidation and reduction potentials between the of the battery was 164 mV when the Ni(OH)2 was doped by 5% NiO,which showed a good cyclic property.


Preparation And Characterization Of Sulfur/Mesoprous Carbon Composite Cathodes, Wen-Hua Zhang, Yao Chen, Xin-Ping Ai, Yu-Liang Cao Feb 2010

Preparation And Characterization Of Sulfur/Mesoprous Carbon Composite Cathodes, Wen-Hua Zhang, Yao Chen, Xin-Ping Ai, Yu-Liang Cao

Journal of Electrochemistry

A sulfur/mesoporous carbon composite was prepared by thermally treating a mixture of sublimed sulfur and mesoporous carbon. The microstructure of the mesoporous carbon was characterized by BET analysis and X-ray diffraction(XRD). The electrochemical performance of the S/C composite as cathode materials was evaluated by the galvanostatic method. The results confirmed that the mesoporous carbon could not only greatly enhance the electrochemical activity of sulfur electrode, but also effectively confine the diffusion of dissolved polysulfides in organic electrolyte. As a result,the S/C composites showed high capacity, good cycle performance and excellent rate capability. The specific capacity of the S/C composite was …


Preparation And Characterizations Of Li3V2(Po4)3 Cathode Material For Lithium Ion Batteries, Hong Chen, Tao Jiang, Chun-Zhong Wang, Gang Chen, Ying-Jin Wei Feb 2010

Preparation And Characterizations Of Li3V2(Po4)3 Cathode Material For Lithium Ion Batteries, Hong Chen, Tao Jiang, Chun-Zhong Wang, Gang Chen, Ying-Jin Wei

Journal of Electrochemistry

The carbon-coated Li3V2(PO4)3 was prepared by carbothermal reduction method.The structural and morphological properties of the material were studied by X-ray diffraction,FTIR and transmission electron microscopy.The synthesized material was a pure phase of Li3V2(PO4)3,with the particle size of about 100 nm.The values of Li ion diffusion coefficient of the material in the potential window of 3.0 ~ 4.3 V were nearly 3 orders larger than those in 3.0 ~ 4.8 V.In addition,the charge-transfer resistances in 3.0 ~ 4.3 V were much smaller than those in 3.0 …


Investigation Of Ceo2 As Cathode Electrocatalyst For Direct Borohydride Fuel Cell, Xue-Min Ni, Ya-Dong Wang, Mu Pan Feb 2010

Investigation Of Ceo2 As Cathode Electrocatalyst For Direct Borohydride Fuel Cell, Xue-Min Ni, Ya-Dong Wang, Mu Pan

Journal of Electrochemistry

The performance of CeO2 as oxygen reduction electrocatalyst in direct borohydride fuel cell was investigated.The experimental results indicate that CeO2 shows significant electrocatalytic performance for oxygen reduction and exhibits no observed promotion effect on hydrolysis or electro-oxidation of BH4-.The power density of experimental one-compartment fuel cell with CeO2 as cathode electrocatalyst can reach a 67.8 mW·cm-2 at room temperature.


Preparation And Electrochemical Behavior Of Li4Ti5O12 Nanosheets As Anode Material For Lithium Ion Battery, Yi-Fei Wang, Yu-Feng Tang, Zheng Qiu, Li Yang Feb 2010

Preparation And Electrochemical Behavior Of Li4Ti5O12 Nanosheets As Anode Material For Lithium Ion Battery, Yi-Fei Wang, Yu-Feng Tang, Zheng Qiu, Li Yang

Journal of Electrochemistry

Spinel lithium titanate(Li4Ti5O12) nanosheets with a size range of 200 ~400 nm were synthesized by hydrothermal process from the amorphous hydrous titanium oxide precursors.The as-prepared products were characterized by X-ray powder diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The electrochemical behaviors of Li4Ti5O12 electrode in conventional organic electrolyte and ionic liquid electrolyte were investigated by using cyclic voltammetry,galvanostatic charge-discharge and AC impedance techniques.The experimental results indicate that the as-prepared nanostructured Li4Ti5O12,evaluated as anode material,exhibited good reversibility and cycle performance.It is expected to be a …


Synthesis Of High-Performance Lini1/3Co1/3Mn1/3O2 Cathode Materials Via Azeotropic Distillation Method, Sheng-An Xia, Li-Xia Yuan, Ze Yang, Zhao-Hui Wang, Yun-Hui Huang, Shuang Li, Wu-Xing Zhang, Ya-Bin Meng, Wei-Gong Zheng Feb 2010

Synthesis Of High-Performance Lini1/3Co1/3Mn1/3O2 Cathode Materials Via Azeotropic Distillation Method, Sheng-An Xia, Li-Xia Yuan, Ze Yang, Zhao-Hui Wang, Yun-Hui Huang, Shuang Li, Wu-Xing Zhang, Ya-Bin Meng, Wei-Gong Zheng

Journal of Electrochemistry

Layered LiNi1/3Co1/3Mn1/3O2 is one of the most promising alternative materials for LiCoO2 in lithium ion batteries due to its low cost,large capacity and excellent cyclability.In this paper,LiNi1/3Co1/3Mn1/3O2 was synthesized via azeotropic distillation method with isobutyl alcohol as an azeotropic agent.The structure and surface morphology were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM),respectively.The as-prepared LiNi1/3Co1/3Mn1/3O2 shows a layered α-NaFeO2 structure;the particles are small and uniformly distributed.As compared with the sample prepared by traditional method,the present cathode material …


Electrochemical Behavior Of Co-Ru Composite In Alkaline Solution, Su-Mei Yao, Guo-Chun Li, Xue-Ping Gao Feb 2010

Electrochemical Behavior Of Co-Ru Composite In Alkaline Solution, Su-Mei Yao, Guo-Chun Li, Xue-Ping Gao

Journal of Electrochemistry

The electrochemical properties of Ru doped cobalt hydroxides synthesized via homogeneous chemical co-precipitation were investigated in 6 mol·L-1 KOH solution by galvanostatic charge-discharge process and cyclic voltammetry(CV).It is demonstrated that Ru doped cobalt hydroxides exhibited good capacitive characteristic and high specific capacitance.The sample with a Co/Ru molar ratio of 8 /1 shows the optimized electrochemical performance,including capacitive property and discharge capacity.The microstructure and morphology of the obtained Ru doped hydroxides were characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM).The amorphous structure of ruthenium dioxide nanoparticles and single-crystal structure of Co(OH)2 platelets were confirmed.Based on a structure analysis and …


Studied Corrosion Behaviors Of Reinforcing Steel In Concrete By A Single-Dimensional Array Electrode, Lan-Qiang Li, Shi-Gang Dong, Rong-Gui Du, Chang-Jian Lin Feb 2010

Studied Corrosion Behaviors Of Reinforcing Steel In Concrete By A Single-Dimensional Array Electrode, Lan-Qiang Li, Shi-Gang Dong, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

A single-dimensional array electrode was developed as a new electrochemical technique to image corrosion potential,galvanic current and polarization curves of reinforcing steel in concrete during corrosion process.Combining with the polarization behavior for each micro-electrode,the interactions between corrosion macrocell and corrosion microcell of the steel in concrete were evaluated.It was noticed that the corrosion macrocell and microcell occurred independently in difference regions at the initial stage of corrosion.The corrosion macrocell current can be in situ followed by corrosion potential imaging.The corrosion propagation of steel in concrete is closely related to the interactions between corrosion macrocell and corrosion microcell.