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2006

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Articles 121 - 150 of 280

Full-Text Articles in Materials Science and Engineering

Laying The Foundation For Nanoscience And Nanotechnology With An Introductory Module For High School Students, Maynard Valerie, Hsu Mathew, Katherine C. Chen, R. H. Chang Jun 2006

Laying The Foundation For Nanoscience And Nanotechnology With An Introductory Module For High School Students, Maynard Valerie, Hsu Mathew, Katherine C. Chen, R. H. Chang

Materials Engineering

In response to the need to create a skilled workforce in nanotechnology and to excite young students with the wonders and potentials of science, the National Center for Learning and Teaching in Nanoscale Science and Engineering, is developing educational materials for grades 7 – 16. Learning theory and cutting-edge research are used in the development of modules on nanoscience and nanotechnology. This paper describes the rationale for such materials and describes an introductory module in which students are lead through a series of inquiry-based and hands-on activities, which lead to a design project. Its goal is to teach an underlying …


The Role Of Industry In Supporting Education In Environmentally Responsible Engineering, Andrew Borchers, David Rinard, Trevor S. Harding, Terri Lynch-Caris Jun 2006

The Role Of Industry In Supporting Education In Environmentally Responsible Engineering, Andrew Borchers, David Rinard, Trevor S. Harding, Terri Lynch-Caris

Materials Engineering

Achievement of a sustainable future implies a collaborative effort between a variety of stakeholders including industry, government, and academia. We are traveling in unfamiliar waters where the course is not always clear and the goals are sometimes daunting. To develop the environmental wisdom we need to help us know the “right answers,” we must bring together the knowledge we get from our academic pursuits with the experience we obtain through trial and error. Bringing together the academic world and the business world not only helps us solve the immediate engineering need, it more importantly builds a partnership that will produce …


Solution Chemistry Control To Make Well Defined Submicron Continuous Fibres By Electrospinning: The (Ch3ch2ch2o)4ti/Acoh/Poly(N-Vinylpyrrolidone) System, Gustavo F. Larsen, Maciej Skotak Jun 2006

Solution Chemistry Control To Make Well Defined Submicron Continuous Fibres By Electrospinning: The (Ch3ch2ch2o)4ti/Acoh/Poly(N-Vinylpyrrolidone) System, Gustavo F. Larsen, Maciej Skotak

Papers in Materials Science

The (CH3CH2CH2O)4Ti/AcOH/poly(N-vinylpyrrolidone) system has been shown to yield suitable formulations for electrohydrodynamic (EHD) processing into continuous fibres and particles. The EHD processability of this, and generally most sol–gel-based formulations, into well defined fibres and particles with narrow submicron-range diameter distributions depends not only on the EHD process variables (electric field and flow rates), but also on the stability of key physical properties (e.g., conductivity, viscosity, surface tension, density and dielectric constant) of the sol over time. Sols that were almost certainly still undergoing hydrolysis and condensation reactions have been processed via EHD by many research groups to make materials with …


Characterization Of Passivated Indium Antimonide, Catherine Ann Taylor Jun 2006

Characterization Of Passivated Indium Antimonide, Catherine Ann Taylor

Theses and Dissertations

Infrared absorption and photoluminescence measurements have been used to optically characterize bulk-grown, 680-μm thick, indium antimonide (InSb), both as-grown and after passivation by either anodization or a 700-Å layer of silicon oxide (SiOx). Spectra were obtained using Fourier transform infrared (FT-IR) spectroscopy. Results include the effects of sample temperature in the range of 10 to 300 K and 4.636 μm laser pump power in the range of 28 mW to 1.43 W for the photoluminescence spectrum.


Infusing The Materials Engineering Curriculum With Sustainability Principles, Katherine C. Chen, Linda Vanasupa, Blair London, Richard N. Savage Jun 2006

Infusing The Materials Engineering Curriculum With Sustainability Principles, Katherine C. Chen, Linda Vanasupa, Blair London, Richard N. Savage

Materials Engineering

In order to better prepare our students for the complex, global world outside the confines of the university, we have been making concerted efforts to incorporate sustainability principles (i.e., balance of economics, society, and environment) within the materials engineering curriculum at California Polytechnic (Cal Poly) State University. Many future engineering tasks will require the understanding of complicated interplays of technology with the environment and society. In addition, energy demands and dwindling natural resources have emerged as significant challenges for scientists and engineers. The materials engineer has great opportunity to help devise sustainable solutions through appropriate materials selection and processing, and …


Cheating In College And Its Influence On Ethical Behavior In Professional Engineering Practice, Trevor S. Harding, Cynthia J. Finelli, Donald D. Carpenter Jun 2006

Cheating In College And Its Influence On Ethical Behavior In Professional Engineering Practice, Trevor S. Harding, Cynthia J. Finelli, Donald D. Carpenter

Materials Engineering

Research has demonstrated that engineering undergraduates report rates of cheating higher than those in most other disciplines and that students who cheat in college are more likely to make unethical decisions as professionals. To explore the relationship between academic and professional ethical behavior, the authors launched the Work Experience Study (WES) that examines students' decision-making processes in situations where they are tempted to engage in unethical behavior in academic and professional settings. The population sampled for WES includes engineering undergraduates with substantial work experience in engineering. Such a sampling strategy enables us to make comparisons between academic and work-place scenarios …


Examining The Underlying Motivations Of Engineering Undergraduates To Behave Unethically, Trevor S. Harding, Cynthia J. Finelli, Donald D. Carpenter, Matthew Mayhew Jun 2006

Examining The Underlying Motivations Of Engineering Undergraduates To Behave Unethically, Trevor S. Harding, Cynthia J. Finelli, Donald D. Carpenter, Matthew Mayhew

Materials Engineering

The need for ethical behavior in engineering professional practice has been demonstrated repeatedly over the years, and most, if not all, academic institutions provide opportunities for engineering students to learn about ethics and professional responsibility. While there has been some investigation of the effectiveness of these academic efforts on student learning of ethics, little attention has been paid to students’ ethical decision-making and behavior. The present study seeks to verify the use of a model of ethical decision-making to predict the tendency of engineering and humanities students to engage in cheating, an unethical behavior with which nearly all undergraduates are …


The Effect Of Sample Size And Ground Granulated Blast-Furnace Slag On Hydration Temperature In Hot Climates, Mariam Eissa Saeed Al-Harrasi Jun 2006

The Effect Of Sample Size And Ground Granulated Blast-Furnace Slag On Hydration Temperature In Hot Climates, Mariam Eissa Saeed Al-Harrasi

Theses

Heat of hydration of Portland cement mixes is of great importance to civil engineers. While there is great deal of work being carried out on the hydration temperature of OPC-slag mixes, there is a lack in the literature of research work on the effect of such materials in real hot climates. The current research examines the influence of ground granulated blast-furnace slag (ggbs) as a partial cement replacement on temperature evolution during hydration in winter and summer in AI-Ain (interior region of the United Arab Emirates). Evolution of temperature inside the concrete was recorded by the aid of a Labview …


Effect Of Environment On Creep Behavior Of An Oxide/Oxide Cfcc With ±45° Fiber Orientation, Gregory T. Siegert Jun 2006

Effect Of Environment On Creep Behavior Of An Oxide/Oxide Cfcc With ±45° Fiber Orientation, Gregory T. Siegert

Theses and Dissertations

Aerospace applications require materials capable of maintaining superior mechanical properties while operating at high temperatures and oxidizing environments. Nextel™ 720/A (N720/A), an oxide/oxide ceramic matrix composite (CMC) with a porous alumina matrix was developed specifically to provide improved long-term properties and performance at 1200°C. This research evaluated the creep behavior of N720/A with a ±45° fiber orientation at 1200°C in: laboratory air, steam, and argon environments. Creep-rupture tests at the creep stress levels of: 45, 40, 35, and 15 MPa were conducted in each environment.
The ultimate tensile strength of N720/A with ±45° fiber orientation was 55 MPa, the elastic …


Wear Analysis Of Cu-Al Coating On Ti-6al-4v Under Fretting, Karl N. Murray Jun 2006

Wear Analysis Of Cu-Al Coating On Ti-6al-4v Under Fretting, Karl N. Murray

Theses and Dissertations

The effects of changes in the coefficient of friction (CoF) between the contacting surfaces on the fretting wear characteristics of Cu-Al coating on Ti-6Al-4V were investigated. This Cu-Al coating is part of a system that is applied to titanium turbine blades to reduce fretting at the interface. In the application, there is a solid lubricant that is added on top of the coating as an assembly aid and to help reduce the friction while the lubricant remains within the contact. Previous studies have researched the characteristics of the coating without the additional lubricant. In this study, liquid motor oil was …


Effects Of Frequency And Environment On Fatigue Behavior Of An Oxide-Oxide Ceramic Matrix Composite At 1200°C, Griffin Hetrick Jun 2006

Effects Of Frequency And Environment On Fatigue Behavior Of An Oxide-Oxide Ceramic Matrix Composite At 1200°C, Griffin Hetrick

Theses and Dissertations

Advances in aeronautical engineering in the 21st century depend upon materials that can perform well in extreme environments such as high temperatures and oxidizing conditions. Nextel™720/Alumina (N720/A) is an oxide/oxide ceramic matrix composite with a porous alumina matrix that has been identified as a candidate material for such applications. This research investigated the effects of frequency on fatigue response of N720/A at 1200°C in both air and steam environment. Prior investigation of this material by Eber [8] in 2005 studied fatigue behavior at 1200°C in air and in steam environments at the frequency of 1.0 Hz. The current research focused …


Application Of Electrolessplating Technology In Interconnection Manufacturing Of Ultralarge-Scale Integration, Zeng-Lin Wang, Zhi-Juan Liu, Hong-Yan Jiang, Xiu-Wen Wang, Shingubara Shoso May 2006

Application Of Electrolessplating Technology In Interconnection Manufacturing Of Ultralarge-Scale Integration, Zeng-Lin Wang, Zhi-Juan Liu, Hong-Yan Jiang, Xiu-Wen Wang, Shingubara Shoso

Journal of Electrochemistry

In this paper,research progresses in electroless plating for damascene copper process were reviewed.Electroless nickel ternary alloy deposition for barrier layer and electroless copper plating for seed layer were presented.Bottom-up copper fill high-aspect-via-hole and electroless plating after ICB-Pd catalytic layer for seed layer were mainly introduced.The applications of electroless plating in ultralarge-scale integration were discussed,and the developing tendency was also suggested.


Synthesis Of Zinc Polyhedral Microspheres And Applications In Alkaline Zn-Mno2 Battery, Hua Ma, Chun-Sheng Li, Fang-Yi Cheng, Chun-Yuan Zhou, Feng Gao, Jun Chen May 2006

Synthesis Of Zinc Polyhedral Microspheres And Applications In Alkaline Zn-Mno2 Battery, Hua Ma, Chun-Sheng Li, Fang-Yi Cheng, Chun-Yuan Zhou, Feng Gao, Jun Chen

Journal of Electrochemistry

The zinc polyhedral microspheres were synthesized by evaporation of pure zinc powders via a vapor-transport process.The results characterized by XRD and SEM show that the as-synthesized zinc powders are polyhedral microspheres with the diameter of 2~3 μm.The electrochemical investigation showed that the capacity of the as-assembled AA-size primary alkaline Zn-MnO2 battery was increased to 3.14 Ah under the constant discharge current of 100 mA by using the as-deposited microspherical zinc powders as the anode active materials and γ-MnOnanowires as the cathode active materials,indicating their potential application in high-energy batteries.


Electrochemical Studies Of Iron-Doped Nickel Oxide Electrode For Oxygen Evolution Reaction, Jin-Zhao Huang, Zheng Xu, Hai-Ling Li, Guo-Hu Kang, Wen-Jing Wang May 2006

Electrochemical Studies Of Iron-Doped Nickel Oxide Electrode For Oxygen Evolution Reaction, Jin-Zhao Huang, Zheng Xu, Hai-Ling Li, Guo-Hu Kang, Wen-Jing Wang

Journal of Electrochemistry

In this paper,the iron-doped nickel oxide thin film as anode catalyst was prepared by RF reactivesputtering method.The oxygen evolution reaction(OER) on the iron-doped nickel oxide was investigated withcyclic voltammetry,liner sweep voltammetry,polarization curves and electrochemical impedance spectroscopy.Results showthat the iron acts as active site in the film which makes the overpotential lower,and changes therate-limiting from primary discharge of OH-ions to the recombination of oxygen atom.With the increasing of ox-ygen content in flu ratio during sputtering,the electrocatalytic activities of the film increase.Iron-doped nickeloxide thin film is promising material as OER electrocatalyst for hydrogen production than the nickel electrode.The oxygen overpotential on the …


Electrochemical Impedance Spectrum Of Ferrocene At A Rotating Disk Glassy Carbon Electrode And Its Interaction With Dna, Can-Hui Chen, Hong Li, Jian-Zhang Zhou, Zhong-Hua Lin, Wei Zhu, Quan-Xin Zhang May 2006

Electrochemical Impedance Spectrum Of Ferrocene At A Rotating Disk Glassy Carbon Electrode And Its Interaction With Dna, Can-Hui Chen, Hong Li, Jian-Zhang Zhou, Zhong-Hua Lin, Wei Zhu, Quan-Xin Zhang

Journal of Electrochemistry

The electrochemical impedance spectrum(EIS) of ferrocene(Fc) at a rotating glassy carbon(GC) electrode and its interaction with calf thymus DNA in Tris-NaCl buffer solution(pH=7.2) have been investigated by using electrochemical techniques such as rotating disk electrode(RDE),EIS and its data fitting.A plateau of the limiting current for the voltammetric curve and two capacitance arches obtained at the rotating GC electrode are exhibited.The interaction of Fc with DNA is represented by the decrease of limiting diffusion current and the increase of electrochemical reaction resistances with the increase of DNA concentration,respectively.On the other hand,based on the theoretical analysis and data fitting of RDE and …


Structure And Properties Of Electrodeposited Sn-Co Alloy Electrodes As Anode Material For Lithium-Ion Secondary Batteries, Hong-Hong Jiang, Ling Huang, Shun-Wei Zhou, Fu-Sheng Ke, Fang-Zu Yang, Xiao-Yong Fan, Shi-Gang Sun May 2006

Structure And Properties Of Electrodeposited Sn-Co Alloy Electrodes As Anode Material For Lithium-Ion Secondary Batteries, Hong-Hong Jiang, Ling Huang, Shun-Wei Zhou, Fu-Sheng Ke, Fang-Zu Yang, Xiao-Yong Fan, Shi-Gang Sun

Journal of Electrochemistry

The Sn-Co alloy deposits were prepared by electroplating.The structure and electrochemical performance of the electroplated Sn-Co alloys have been investigated in detail. Experimental results show that the porous Sn-Co alloy film exhibits hexagonal solid solution,with Sn as the solvent, Co as the solute. The texture of the Sn-Co alloy coating exhibits(110) preferred orientation. Electrochemical tests show that the porous Sn-Co alloy coating electrodes can deliver a discharge capacity of 643mAh/g in the first cycle. At the 20h cycle the charge was 461mAh/g. At initial charge curve the irreversible capacity is probably associated to a combination of processes, which may …


High Density Lifepo4/C Synthesized By Controlled Crystallization And Microwave Carbon Thermal Reduction, Chang-Ping Tang, Jie-Rong Ying, Min Lei, Wei Li, Chang-Yin Jiang, Chun-Rong Wan May 2006

High Density Lifepo4/C Synthesized By Controlled Crystallization And Microwave Carbon Thermal Reduction, Chang-Ping Tang, Jie-Rong Ying, Min Lei, Wei Li, Chang-Yin Jiang, Chun-Rong Wan

Journal of Electrochemistry

The spherical FePO4·xH2O was prepared in the solution by controlled crystallization.The precursor FePOwas obtained in high temperatureceramic approach,then the high density LiFePO/C was synthesized by microwave carbon thermal reduction.The structure and morphology of the materials were characterized by means of XRD and SEM techniques,and the electrochemical properties were studies by charge-discharge experiments.


Effect Of Cracks On Corrosion Of Rebar In Concrete Studied By Wire Beam Electrode, Guo-Xi Li, Xian-Lu Hou, Ri-Long Zhu, Jin-Feng Hu, Yan-Na Du May 2006

Effect Of Cracks On Corrosion Of Rebar In Concrete Studied By Wire Beam Electrode, Guo-Xi Li, Xian-Lu Hou, Ri-Long Zhu, Jin-Feng Hu, Yan-Na Du

Journal of Electrochemistry

The effects of crack and ethanolamine on corrosion of rebar in concrete were studied by measuring the distribution of corrosion potential and polarization resistance of iron wires in 10% NaCl solution.The results showed that the diffusion of water,oxygen and chloric ion toward concrete was accelerated by the crack which intensified the nonuniform corrosion of iron wire with the regions near to crack as anode and the uncracked regions as cathode.Ethanolamine could diffuse into the body of concrete and absorb on the surface of iron wire,which reduced iron corrosion evidently and successfully inhibited the nonuniform corrosion caused by crack without changing …


Preparation Of Spherical Ni(Oh)2 Coated With Coooh And Its Fast Charge Performance, Min-Jie Yang, Jun-Min Nan, Jian-Jun Xue, Yan Cui, Ming Cui May 2006

Preparation Of Spherical Ni(Oh)2 Coated With Coooh And Its Fast Charge Performance, Min-Jie Yang, Jun-Min Nan, Jian-Jun Xue, Yan Cui, Ming Cui

Journal of Electrochemistry

Spherical Ni(OH)2 was coated with CoOOH through chemical precipitation and electrolytic oxidation.The influences of CoOOH coating on fast charge performance ofMH/Ni battery were studied by preparing high capacity and fast charge AA size MH/Ni batteries.The sample coated with CoOOH was characterized by Infrared spectrum(IR) and scanning electron microscopy(SEM).The results showed that the internal resistance decreased 3.4 mΩ,the charge plateau lower and the cell temperrature was below 55 ℃ at the end of charging process when the cathode active material used Ni(OH)2 coated with CoOOH as compared with that doped by CoO.In addition,an initial discharge efficiency of 90.6% and …


Tyrosinase Immobilizarion On Boron-Doped Diamond Electrodes And The Determination Of Phenolic Compounds, Yan-Li Zhou, Jin-Fang Zhi May 2006

Tyrosinase Immobilizarion On Boron-Doped Diamond Electrodes And The Determination Of Phenolic Compounds, Yan-Li Zhou, Jin-Fang Zhi

Journal of Electrochemistry

As-grown BDD surfaces were first functionalized by photochemically linking vinyl groups of allylamine,producing covalently linked amine-terminated active BDD surfaces.Then the tyrosinase was immobilized onto the BDD surface through peptide linking.Cyclic voltammograms of phenol,pcresol and hydroquinone were measured using the tyrosinase-modified BDD electrode and amperometric characteristics such as sensitivity,linear response range and stability were studied.


Electrochemical Studies On Electrocatalytic Activity Of AuCore PtShell Nanoparticles To Methanol Oxidation, Fang Bao, Jian-Lin Yao, Ren-Ao Gu May 2006

Electrochemical Studies On Electrocatalytic Activity Of AuCore PtShell Nanoparticles To Methanol Oxidation, Fang Bao, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

AucorePtshell nanoparticles with different thicknesses were prepared by using chemical reduction method,and characterized by ultraviolet-visible spectroscopy(UV-Vis),transmission electron microscopy(TEM) and cyclic voltammetry(CV).The electrocatalytic activity of AucorePtshell nanoparticles with the mean diameter of 70~80 nm to methanol oxidation was investigated by cyclic voltammetry in the acid solution.The results revealed that the prepared core-shell nanoparticles were covered by Pt shell and exhibited the similar optical property and electrocatalytic activity with the normal Pt surface.Moreover,the electrocatalytic activity increased with the electrochemical sweep in the certain potential range.It might be contributed by the special loose structure of Pt shell …


Electrochemical Preparation Of Gd-Ni Alloy Film In Acetamide-Urea-Nabr Melt, Bi-Qing Chen, Jian-Chao Wang, Chen-Yu Guo, Jin-Gui Wang, Qing Liu May 2006

Electrochemical Preparation Of Gd-Ni Alloy Film In Acetamide-Urea-Nabr Melt, Bi-Qing Chen, Jian-Chao Wang, Chen-Yu Guo, Jin-Gui Wang, Qing Liu

Journal of Electrochemistry

Cyclic voltammetry was used to study the electroreduction of Ni2+ to Ni on Pt and Cu electrode in acetamide-urea-NaBr melt at 353K.It is irreversible in one step.At Pt and Cu eletrode the diffusion coefficient and electron transfer coefficient of Ni2+ in 0.063mol/dm3) NiCl2-acetamide-urea-NaBr melt were determined.The transfer coefficient α=0.28 and diffusion coefficient D_(0)=4.63×10-5 cm2·s-1 of the Pt eletrode and transfer coefficient α=0.22 and diffusion coefficient D_(0)=6.05×10-7 cm2·s-1 of the Cu eletrode were measured.It was put emphasis on that Gd3+ is not reduced to Gd alone …


Study On Composite Organic Inhibitor Of Zinc Electrode In Alkaline Solutions, Xue-Tao Bu, Guang-Chuan Liang, Cui Li May 2006

Study On Composite Organic Inhibitor Of Zinc Electrode In Alkaline Solutions, Xue-Tao Bu, Guang-Chuan Liang, Cui Li

Journal of Electrochemistry

The synergetic influence of sodium dodecyl benzene sulfonate(SDBS) with Tween-20(Tween) on zinc electrode was studied by polarization experiment,surface tension test,discharge test and SEM.It is found that the composite inhibitor ST has a much higher efficiency.The addition of Tween reduced the critical micell concentration of SDBS on zinc electrode remarkably and the distribution of adsorption became more homogeneous.ST inhibits corrosion of zinc electrode and improves discharge capacity of the whole battery.Through electrochemical morphological observation of anodic passivation behaviors of zinc electrode,the absorption of ST on electrode surface makes discharged production much smaller and keeps crude porous structure intact.Passivation of zinc electrode …


Electrodeposition Of Three-Dimensional Porous Copper Films Using Hydrogen Bubbles As Template, Ya-Feng Sun, Zhen-Jiang Niu, Shu-Qiong Cen, Ze-Lin Li May 2006

Electrodeposition Of Three-Dimensional Porous Copper Films Using Hydrogen Bubbles As Template, Ya-Feng Sun, Zhen-Jiang Niu, Shu-Qiong Cen, Ze-Lin Li

Journal of Electrochemistry

Using cathodic hydrogen bubbles as a template,the three-dimensional(3-D) porous copper films have been successfully electrodeposited from a bath of 0.2 mol·dm-3 CuSO4 and 1.5 mol·dm-3 H2SO4,effects of deposition parameters including temperature,current density and additives(Na2SO4,HCl and Polyethylene glycol(PEG)) on the morphologies of the deposits have been systematically studied.SEM results showed that both the pore size and thickness of the pore walls decreased with cooling the electrolyte temperature or adding(Na2SO4) or PEG into the bath when the other deposition parameters were fixed.With addition small amounts of HCl …


Corrosion Behavior Of The Welding Seam Of The Q235 Steel Jointed By J420 Electrode In Ammonium Sulfite Solution, A-Li Lei, Qiao-Qin Guo, La-Jun Feng May 2006

Corrosion Behavior Of The Welding Seam Of The Q235 Steel Jointed By J420 Electrode In Ammonium Sulfite Solution, A-Li Lei, Qiao-Qin Guo, La-Jun Feng

Journal of Electrochemistry

The corrosion behavior of welding seam of the Q235 steel jointed by J420 electrode in ammonium sulfite solution was researched.The results of electrochemical method of welding seam and metallurgical structure analysis showed that the poor corrosion resisting property was determined by its structure after the Q235 steel was jointed by J420 electrode.The sulfite corrosion rate was accelerated by increasing the temperature and concentration of ammorium.


Effect Of Preparation Conditions On Electroluminescence Of Porous Silicon, Ya-Jun Yang, Qing-Shan Li, Xian-Yun Liu, Ning Zhang, Bo Zhao, Xue-Gang Zheng, Ming-Ji Shi, Da Chen, Jing-Jing Wang May 2006

Effect Of Preparation Conditions On Electroluminescence Of Porous Silicon, Ya-Jun Yang, Qing-Shan Li, Xian-Yun Liu, Ning Zhang, Bo Zhao, Xue-Gang Zheng, Ming-Ji Shi, Da Chen, Jing-Jing Wang

Journal of Electrochemistry

Electrically induced visible light emitting porous silicon devices with the structure of ITO/PS/p-Si/Al were fabricated by evaporation-anodic oxidation method.The light emission last for a few hours under 7.5V forward bias conditions.It was shown that the electroluminescence(EL) peaks shifted to the blue with the increasing of current density,erosion time and solution concentration.In order to achieve samples with low driven voltage,long light emission time and high EL efficiency,porous silicon should be prepared under low current density and short erosion time.


Electrochemical Behavior And Reduction Mechanism Of High Valence Silver Oxide Ag3O4 In Alkaline Solution, Yan Cheng, Ming Yu, Man-Ming Yan, Zhi-Yu Jiang May 2006

Electrochemical Behavior And Reduction Mechanism Of High Valence Silver Oxide Ag3O4 In Alkaline Solution, Yan Cheng, Ming Yu, Man-Ming Yan, Zhi-Yu Jiang

Journal of Electrochemistry

The electrochemical properties of high-valence silver oxide Ag3O4 in alkaline solution were investigated for the first time and the reduction mechanism of Ag3O4 was proposed. It can be recognized that Ag3O4 consists of Ag(Ⅲ) and Ag(Ⅱ)~(*). From the results of voltammetry and XRD experiments it was found that the reduction process of Ag3O4 was more complicated. It could be electrochemically reduced through the series reactions of Ag(Ⅲ) →Ag(Ⅱ) →Ag(Ⅰ) →Ag(O) at low discharge rate or Ag(Ⅲ) →Ag(Ⅰ) →Ag(O) at higher discharge rate.And the Ag(Ⅱ)~(*) could be reduced to …


Development Of Ferrocement U-Shaped Beams Infilled With Core Materials, Ahmed Mahdy Abdelnaby May 2006

Development Of Ferrocement U-Shaped Beams Infilled With Core Materials, Ahmed Mahdy Abdelnaby

Archived Theses and Dissertations

No abstract provided.


Cerium-Based Spontaneous Coating Process For Corrosion Protection Of Aluminum Alloys, James O. Stoffer, Thomas J. O'Keefe, Matthew O'Keefe, Eric L. Morris, Scott A. Hayes, Paul Yu, Alex Williams, Berny F. Rivera Vasquez, Xuan Lin May 2006

Cerium-Based Spontaneous Coating Process For Corrosion Protection Of Aluminum Alloys, James O. Stoffer, Thomas J. O'Keefe, Matthew O'Keefe, Eric L. Morris, Scott A. Hayes, Paul Yu, Alex Williams, Berny F. Rivera Vasquez, Xuan Lin

Chemistry Faculty Research & Creative Works

A cerium-based coating for corrosion resistance is applied by exposing a cleaned aluminum-based component to a corrosion-inhibiting cerium solution containing cerium ions in the presence of an oxidizing agent. The coating deposits spontaneously without an external source of electrons.


Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall May 2006

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …