Materials Science and Engineering Commons^™

Effect Of 2,2'-Dipyridyldipyridyl And K4Fe(Cn)6 On Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Dan-Dan Shen, Fang-Zu Yang, Hui-Huang Wu

Journal of Electrochemistry

The electroless copper plating was studied in a bath consisting of glyoxylic acid as reducing agent,Na₂EDTA as complexing agent,both 2,2'-dipyridyl and K₄Fe(CN)₆ as additives,focused on the influence of the additives on the deposition rate,as well as on the composition,structures and surface morphology of the deposits.It was found that adding an optimum amount of 2,2'-dipyridyl and K₄Fe(CN)₆ to the bath will not only improve the stability of the bath,but also increase the deposition rate by 100 %.The simultaneous addition of both additives causes the deposits to bright appearance and the change in morphology.The …

Study On The Electrochemical Machining Of Titanium Alloys Tc4 With The Method Of Uniform Design, Mei-Li Zhang, Di Zhu, Zheng-Yang Xu

Journal of Electrochemistry

For the electrochemical machining of titanium alloys,a passivating film tends to form on the machining surface,which holdbacks the process of machining;and some corrosive pittings can appear on the non-machining surface,which leading to the poor surface quality.So how to improve the machining surface quality,this is a hot problem in aerospace industries.An experiment plan has been made with the method of uniform design and the variance analysis has been carried out using the result data of the previous experiments.The experimental results show that an excellent machining surface with Ra 0.38 μm would be obtained in the electrolyte of 10% NaCl solution,4% Na …

The Influence Of Electrolytic Conditions On Synthesis Of Feo42-, Yan Zhou, Wei-Hua Yang, Dong-Qin Bi, Ting-Ting Huang, Zhen Sun, Quan-Feng Guo

Journal of Electrochemistry

The FeO₄^2-was synthesized using iron lattice as anode and the solid K₂FeO₄ was also prepared.Influence of electrolytic conditions,such as stir,ultrasonic,temperature and current density on the current efficiency were studied.The results showed that preferable ferrate(VI) current yield was obtained in a current density of 10 mA·cm^-2,temperature 30 ℃ and 14 mol/L NaOH as electrolyte under at stirring effect.

Variable Frequence Switching Power Supply Used To Aluminum Foil Corrosion, Xiang-Dong Zhuo, Lan Sun, Guo-Qing Qian, Chang-Jian Lin

Journal of Electrochemistry

A new variable frequence and multi-wave power supply used to aluminum foil corrosion is introduced. The switching supply power supply controlled by the microcontroller and Variable Frequence in low band and multi-wave, big power supply controlled by the electronic switch bridge for changing phase were designed. This power supply does not need bulky and cumbersome transformer, and the frequency at lower limit is not limited, even lower than 1Hz.

Effects Of Direct Current Bias Potentials On Lipid Membranes Forming On A Glassy Carbon Electrode, Yu-Hui Li, Hong-Wei Zhang, Gui-Lan Song, Zhan-Jun Zhang, Sheng-Min Cai

Journal of Electrochemistry

The effects of direct current(DC) bias voltage on the structure of lipid membranes forming on a glassy carbon electrode(GCE) was investigated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).The experiment showed that the lipid membranes can be formed with either positive or negative bias potential exerted.When bias voltage was exerted,bilayer lipid membranes tended to form due to the electrostatic interaction between the superficial positive charges on the polarized electrode and the negative charged part of PC.When the positive bias voltage overrun the range,the lacunas on s-BLMs would increase,and the BLMs would be broken.A proper equivalent circuit was nonlinearly fitted,based on the …

Comparison Of The Electrochemical Reactivity Of Electrodes Modified By Carbon Nanotubes With Different Sizes, Guo-Feng Yang, Neng-Qin Jia, Zhi-Yong Wang

Journal of Electrochemistry

The electrochemical activity of multi-walled carbon nanotubes(MWNTs) with different sizes,including four different MWNTs with the same length and different diameter,two different MWNTs with the same diameter and different length has been assessed and compared.The various MWNTs modified electrodes were prepared by immobilizing the suitable amount of MWNTs onto a glassy carbon electrode,and their voltammetric responses to ferricyanide,uric acid and dopamine were examined.The corresponding cyclic voltammetric data was showed that the electrochemical and electrocatalytic activities are depended on the nanotube length.The electrochemical reactivity of short MWNT(S-MWNT) is better than that of long MWNT(L-MWNT),which may be mainly attributed to the existence of …

Composite Electroplating And Characterizations Of Sn-Sba15 Anode For Lithium-Ion Batteries, Xiao-Yong Fan, Jin-Mei Xu, Quan-Chao Zhuang, Hong-Hong Jiang, Ling Huang, Yan-Xia Jiang, Quan-Feng Dong, Shi-Gang Sun

Journal of Electrochemistry

Sn-SBA15 anode was prepared by composite electroplating. The first discharge and charge capacity was 1075mAh/g and 630mAh/g respectively. After fifty charge/discharge cycles, the charge and discharge capacity of Sn-SBA15 were retained above 400mAh/g. XRD patterns indicated that the Sn-SBA15 has tetragonal crystal type. SEM images showed that the Sn-SBA15 had a honeycombed surface. EIS results indicated that there was SEI film formed on the surface of Sn-SBA15 electrode.

Electrochemical Oxidation Of The Phenol In The Chloride System, Yong Liu, Dan Liu, Shi-Lin Zhao, Jing-Jing Lai

Journal of Electrochemistry

The Ru-Ir /Ti electrode as cathode to electrolysis the synthetic phenolic wastewater was studied. The effect of the initial chloride concentration on the electrolytic treatment result has been discussed. Experiment result shows that the electrochemical oxidation of phenol suits to one kinetics equation in given electrolytic time. If the initial chloride concentration in wastewater increases, the time of the electrochemical oxidation of phenol can be shorten, in other words the apparent rate constant is greater. The middle matters of electrochemical oxidation of phenol in the chloride system detected out by HPLC and GC-MS is mainly 1-chloro-phenol, 4-chloro-phenol, 2,4-dichloro-phenol, 2,6-dichloro-phenol, 2,4,6-trichloro-phenol, …

Diamond-Like-Carbon Film Prepared On Stainless Steel Substrates By Liquid Phase Electrochemical Deposition, Jing-Yong Du, Gui-Feng Zhang, Guo-Qing Li, Xiao-Duo Hou

Journal of Electrochemistry

Diamond-like carbon (DLC) films were deposited on stainless steel substrates at atmospheric pressure and low temperature (60 ℃) by electrolysis in a methanol solution with a pulseddirect current power supply. The morphology and microstructure of the resulting DLC films were analyzed using atomic force microscopy(AFM), scanning electron microscopy (SEM), Raman spectroscopy and Fourier transformation infrared spectrometry (FTIR). The experimental results show that the hydrogenated diamond-like carbon filmsare smooth and compact. Raman spectroscopy analysis confirmed the presence of a strongpeak at 1332.51 cm^-1, which is assigned to crystalline diamond. The deposition rate can be enhanced to 0.5 μm/h by …

Preparation And Lithium Storage Performance Of Nano-Structural Sno2/Carbon Nanotubes Composite Electrodes, Hong-Bing Wei, Ling Huang, Xiao-Bin Wu, Fu-Sheng Ke, Jin-Shu Cai, Xiao-Yong Fan, Fang-Zu Yang, Shi-Gang Sun

Journal of Electrochemistry

The Nano-structural SnO₂/Carbon Nanotubes Composites were prepared in a solution of SnCl₂,ethylene glycol(EG),purified MWCNTs and sodium dodecyl sulfate(SDS) at 160 ℃.The phase structure and surface morphology of the composites were measured by XRD HRTEM and SEM.The results indicate that there are high dispersions and high loadings of SnO₂ nanoparticles on MWCNTs.Electrochemical lithium storage performance was studied preliminarily on the obtained samples.MWCNTs modified with SnO₂ nanoparicles were shown to have a higher electrochemical reversible capacity than that of MWCNTs during the charge and discharge process.MWCNTs can accommodate the larger structure strain of the active materials …

Investigations On Edlcs Using Pmma-Based Gel Polymer Electrolytes, Xiang-Li Meng, Jin-Ling Yin, Juan Ren, Bao-Hong Zhang

Journal of Electrochemistry

Polymethyl methacrylate(PMMA) based gel polymer electrolytes electrochemical double layer capacitors(GPE-EDLCs) were fabricated by an in situ polymerisatonal method with actived carbon electrodes,using propylene carbonate(PC) and ethylene carbonate(EC) as plasticizer,lithion perchlorate as surporting electrolytes.The ion conductivity values of GPEs were evaluated by AC impedance.The properties of PMMA-based GPEs capacitors were researched by impedance spectrum,cyclic voltammetry,galvanostatic charge-discharge.It showed that the ion conductivities of the PMMA-based gel polymer electrolytes reached to 3.7 mS·cm^-1 at ambient tempreture.The working voltage of the capacitors reached to 3.0 V.The specific capacitance of the capacitor was obtained as high as 41.6 F·g^-1(I=1 mA·cm^-2).The …

Fabrication And Performance Of Ni-Scsz Cermet Anode Modified By Coating With Gd0.2Ce0.8O2 For A Sofc, Ren-Zhu Liu, Bo Huang, Xiao-Feng Ye, Shao-Rong Wang, Jia-Di Cao, Huai-Wen Nie, Ting-Lian Wen

Journal of Electrochemistry

A Ni-scandia-stabilized zirconia(Ni-ScSZ) cermet anode modified by coating with nano-sized gadolinium-doped ceria(GDC,Gd_0.2Ce_0.8O₂) was prepared using a simple combustion process for the solid oxide fuel cell(SOFC) running on methane fuel. X-ray diffraction(XRD) and scanning electron microscopy(SEM) indicated that the surface of Ni-ScSZ was coated by nano-sized GDC particles(<100nm). Single cell testing showed that the 2.0%(by mass) GDC-coated Ni-ScSZ anode had better performance. The highest power densities of the cell with this anode were 825 and 848mW/cm² at 850℃ in humidified hydrogen and methane, respectively, whereas the corresponding values were 584 and 586mW/cm² for the cell with Ni-ScSZ anode.Electrochemical impedance spectra(EIS) illustrated that the cell with Ni-ScSZ anode exhibited far greater impedances than the cell with 2.0%(by mass) GDC-coated Ni-ScSZ anode.Then the …

The Effect Of Oil Swelling On The Fatigue Life Of Elastomers Subjected To Cyclic Bubble Inflation, Niall Murphy, John Hanley, Stephen Jerrams, Ali Hassan

Conference Papers

This paper describes the behaviour of rubber in multi-axial fatigue, with respect to oil resistance. A series of tests were carried out on EPDM specimens subjected to varying degrees of swelling. The control methodology and the loading mechanism employed in the testing of elastomers using dynamic multi-axial bubble inflation are outlined. Swollen specimens were prepared by immersing them in reference mineral oil. Specimens were cycled to failure and the results were analysed. The number of cycles to failure for a given engineering stress amplitude was plotted for both dry (unswollen) and swollen specimens. Fracture surfaces for each set of specimens …

A Finite Element Material Model Applied To A1-Alloy Consolidates Processed Via Equal Channel Angular Extrusion, Khalil Ibrahim El Khodary

Archived Theses and Dissertations

No abstract provided.

Nanofibrous Articles, Gene Kim, Bonnie Bachman, Stephen O. Bozzone

Economics Faculty Research & Creative Works

Nanofibrous articles can be manufactured by a process that includes preparation of a surface of a substrate to provide an adhesion mechanism for securing the nanofibers to the surface. The nanofibers can be dispersed in an area near the substrate for the purpose of being adhered to the surface. If an ordered arrangement of nanofibers is required, an electric field can be provided in the area where the nanofibers are dispersed to selectively control an ordering of the nanofibers as they are adhered to the surface by the adhesion mechanism.

High Temperature Heat Exchanger Project: Quarterly Progress Report October 1, 2006 Through December 31, 2006, Anthony Hechanova

Publications (NSTD)

Modifications to the single-channel models of the Ceramatec heat exchanger and decomposer concept for hexagonal flow channels under two values of layer-overlapping (50% and 100%) and for diamond-shaped flow channels were completed.

The finite element calculations of the “Ball on Three Ball Test” for ceramic material for the purpose of selecting the appropriate specimen thickness for future experimental testing was performed for plate thicknesses ranging from 2 to 8 mm.

A finite element model of the “Ball on Three Ball Test” was also studied for discs having micro-channels.

Environmental Effects On Corrosion Properties Of Alloy 22, Mano Misra, L. G. Mcmillion

Publications (YM)

Subtask 1: Experimental Determination of Parameters for the General Corrosion Model Subtask 2: Corrosion Under Dust Deposits Containing Hygroscopic Salts Subtask 3: Heated Electrode Approach for the Study of Corrosion Under Aggressive Conditions Subtask 4: Effect of Hydrogen Permeation on the Stability of the Passive Film of Alloy 22

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For Yucca Mountain Repository, Dhanesh Chandra, Jaak J.K. Daemen

Publications (YM)

Outline

Metallurgical Issues in Underground Repository Reinforcement Support for Nuclear Materials Storage in simulated Yucca Mountain Environment used for Corrosion Issues
Issues related to I-beams (Low Carbon) and Rock Bolts (Med. Carbon)

Experimental

Results

1. Corrosion Tests- Effect of Ionic Concentration (1x,10x,100x), Temperature, concentration and aeration/deaeration effects in YM waters (RB and I-Beam)
2. Hydrogen Permeation Tests
3. Environmentally Assisted Corrosion Tests - Stress Corrosion Cracking/Hydrogen Embrittlement in 100x YM water concentration at Room Temperature and 85oC (I-Beams)

Phase Stability And Segregation In Alloy 22 Base Metal And Weldments, Jeffrey Lacombe, G. L. Mcmillon

Publications (YM)

Subtask 1: Microstructural Characterization of Phase Stability and Variability in Alloy 22. Develop an improved understanding of Alloy 22 and the extent to which compositional and microstructural variations are present in otherwise “nominal” as-procured material. Subtask 2: Electrochemical Methods to Detect Susceptibility of Alloy 22 to Localized Corrosion. Study the influence that compositional and microstructural variations have on the corrosion performance of Alloy 22.

Study Of Structure Development During Melt Spinning Of Isotactic Polypropylene Fibers Using Raman Spectroscopy And Wide Angle X-Ray Diffraction Simultaneously , Dushyanth Pandana

All Theses

ABSTRACT
Isotactic polypropylene (iPP) fibers have a wide variety of applications. Specific end-use applications require specific properties, which are dependent on the polymer morphology produced during processing. Therefore, the final properties of a material are dependent on the processing parameters. iPP fibers are produced mainly by melt spinning. The important processing parameters in the melt spinning process include, the extrusion temperatures, the throughput and shear rates, the rate of cooling, and the feed and draw roll take-up velocities. An understanding of how the morphology develops along the spinline, and the effect of processing parameters on the morphology is crucial in …

Influence Of Lithophysae Geometry On Mechanical Properties Of Hydro-Stone®, Moses Karakouzian, Doug Rigby

Publications (YM)

85 percent of YM drift tunnels will be constructed in lithophysal volcanic tuff. Rock behavior depends on porosity. Limited experimental data exists to characterize rock porosity and dependencies on properties such as σc , E, and n.

Synthesis And Photocatalysis Study Of Brookite Phase Titanium Dioxide Nanoparticles, Radhika Bhave

All Theses

Titanium dioxide is used in variety of applications like photocatalysis, self-cleaning coatings, fog proof glass and water purifier. A lot of research is being done in synthesis and applications of TiO2. Titanium dioxide or TiO2 mainly exists in three phases namely anatase, brookite and rutile. Current studies relate to synthesis of brookite phase TiO2 nanoparticles by ambient condition sol (ACS) process and characterization of these particles for phase purity, morphology and surface area analysis. The photoactivity of these particles was investigated and absorption in the visible light region was detected. This implies brookite to have good potential to be used …

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For The Yucca Mountain Repository — Quarterly Technical Report No. 10, Dhanesh Chandra, Jaak J.K. Daemen

Publications (YM)

This report shows the work done for this period in accordance to cooperative agreement of University of Nevada system for the Task 019 “Subsurface Corrosion Research on Rock Bolt System, Perforated SS Sheets and Steel Sets for the Yucca Mountain Repository”, the overall objective of which is to conduct corrosion research and predict the durability of rock-bolts and other underground metallic roof supports. We are performing oxidation tests using Thermogravimetric Analyzer (TGA), and Potentiodynamic tests to determine the corrosion rates of rock bolts, other support materials including bench mark materials. In this quarter: Potentiodynamic tests were performed to determine corrosion …

Integrating Project-Based Learning Throughout The Undergraduate Engineering Curriculum, Richard N. Savage, Katherine C. Chen, Linda Vanasupa

Materials Engineering

Equipping engineering students with the skills and knowledge required to be successful global engineers in the 21st century is one of the primary objectives of undergraduate educators. Enabling students to practice self-directed learning, to find solutions to design problems that are sustainable and to recognize that they are part of a global community are just of few of our educational goals. Self-directed learning can define an individual’s ability to practice life-long learning. It places the responsibility on the individual to initiate and direct the learning process and can enable an individual to adapt to change. Project-based learning provides the contextual …

Development Of Single Chamber Solid Oxide Fuel Cells With Porous Samaria Doped Ceria Electrolytes, Nathaniel Goss

Opportunities for Undergraduate Research Experience Program (OURE)

Single chamber solid oxide fuel cells generate electricity using hydrogen and hydrocarbon fuel mixed with oxygen at intermediate temperatures (400-800°C) without using seals to separate the gases. A single-chamber solid oxide fuel cell was fabricated with a porous samaria doped ceria (SOC) electrolyte, nickel oxide anode, and a lanthanum strontium cobalt iron oxide (LSCF) cathode. Instead of separately sintering the different components at different temperatures, the electrolyte and electrodes were co-sintered at 1100°C. The porous SOC electrolyte approached 84% theoretical density when sintered at 1100° C. The fuel cell had a maximum open circuit voltage of .65 V at 550°C. …

Microstructures And Viscoelastic Properties Of Anisotropic Magnetorheological Elastomers, Lin Chen

Articles

The microstructures and viscoelastic properties of anisotropic magnetorheological elastomers were investigated in this paper. The measurement results show that their mechanical properties are greatly dependent on the magnetic flux density applied in preparation. A finite-column model was proposed to describe the relations between the microstructures and the viscoelastic properties. The simulation results agree well with the experimental results.

Investigation On Magnetorheological Elastomers Based On Natural Rubber, Lin Chen

Articles

Magnetorheological Elastomers (MR Elastomers or MREs) are a kind of novel smart material, whose mechanical, electrical, magnetic properties are controllable under applied magnetic fields. They have attracted increasing attentions and broad application prospects. But conventional MREs are limited to wide applications because their MR effects and mechanical performances are not high enough. This paper aims to optimize the fabrication method and to fabricate good natural rubber based MREs with high modulus by investigating the influences of a variety of fabrication conditions on the MREs performances, such as matrix type, external magnetic flux density, and temperature, plasticizer and iron particles. Among …

Ferroelectric Properties Of Langmuir-Blodgett Copolymer Films At The Nanoscale, A. Tolstousov, R. V. Gaynutdinov, R. Tadros-Morgane, Herbert Kliem, Stephen Ducharme, Vladimir M. Fridkin

Stephen Ducharme Publications

Langmuir-Blodgett (LB) films are well known structures prepared as a result of successive transfer of monolayers (ML) from the gas-liquid interface onto solid substrates. One impressive possibility of LB method is the opportunity to vary the thickness of the film to an accuracy of one transfer, which could coincide with one ML. The ferroelectric properties of a copolymer of vinylidene fluoride and trifluorethylene P[VDF-TrFE] prepared by LB deposition are investigated in the region of a few monolayers.

Pairwise Cobalt Doping Of Boron Carbides With Cobaltocene, A. Yu. Ignatov, Yaroslav B. Losovyj, L. Carlson, D. Lagraffe, Jennifer I. Brand, Peter A. Dowben

Materials Research Science and Engineering Center: Faculty Publications

We have performed Co K-edge x-ray absorption fine structure and x-ray absorption near edge structure measurements of Co-doped plasma enhanced chemical vapor phase deposition (PECVD) grown “C₂B₁₀H_x” semiconducting boron carbides, using cobaltocene. Cobalt does not dope PECVD grown boron carbides as a random fragment of the cobaltocene source gas. The Co atoms are fivefold boron coordinated (R=2.10±0.02 Å) and are chemically bonded to the icosahedral cages of B₁₀CH_x or B₉C₂H_y. Pairwise Co doping occurs, with the cobalt atoms favoring sites some 5.28±0.02 …

Cluster-Assembled Iron-Platinum Nanocomposite Permanent Magnets, Xiangxin Rui, Zhiguang Sun, Yinfan Xu, David J. Sellmyer, Jeffrey E. Shield

Materials Research Science and Engineering Center: Faculty Publications

Exchange-spring nanocomposite permanent magnets have received a great deal of attention for their potential for improved the energy products. Predicted results, however, has been elusive. Optimal properties rely on a uniformly fine nanostructure. Particularly, the soft magnetic phase must be below approximately 10 nm to ensure complete exchange coupling. Inert gas condensation (IGC) is an ideal processing route to produce sub-10 nm clusters method. Two distinct nanostructures have been produced. In the first, Fe clusters were embedded in an FePt matrix by alternate deposition from two sources. Fe cluster content ranged from 0 to 30 volume percent. Post-deposition multi-step heat …