Engineering Commons^™

Corrosion Barrier Development For Lbe Corrosion Resistance: Quarterly Report (April 2006), Biswajit Das

Transmutation Sciences Materials (TRP)

As reported in the last quarterly report, synthesis of Cr nanowires was found to be problematic in terms of uniform coverage. Hence Ni was identified as the alternative metal to form the nanowires. The purpose of the metal nanowires is to provide structural integrity to the nanoporous alumina, as well as a second defense mechanism against corrosion by oxidizing in case the top alumina layer is compromised. Nickel was selected due to its established electrochemical synthesis procedure. While Ni can provide very good structural integrity to the porous alumina, one potential problem is its higher dissolution rate in LBE. However, …

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive …

Second Generation Waste Package Design Study, Sam Armijo, Mano Misra

Publications (YM)

The design of waste packages currently proposed for YMP is highly conservative. The candidate materials of construction of the waste packages and drip shields while highly corrosion resistant are extremely expensive and components made from these materials will require complex and expensive fabrication methods to assure their integrity. A proposed, second generation operating concept and waste package design, is intended to permit more efficient and less costly operation of the repository while maintaining waste package integrity. Major reductions in waste package costs can be realized by increasing the number of fuel assemblies stored in each waste package, eliminating the reference …

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 1st Quarterly Report, 2006, Clemens Heske

Fuels Campaign (TRP)

This project is devoted to an in-depth study of the chemical and electronic impact of metal fission products on the coating layers in TRISO nuclear fuel. In particular, there is a focus on the investigation of Pd, Cs, and Ag and their interface formation with SiC and carbon-based substrates. A variety of surface and near-surface bulk sensitive probes that investigate the occupied and unoccupied electronic states of the substrate and the metal overlayer have been utilized. By a controlled and stepwise deposition of the metal overlayer, it is possible to gain substantial insight into the formation of interfaces and their …

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

In this project the chemical bonding and interface formation of metal fission products with the coating materials used in TRISO fuel particles is investigated. The interface formation of Pd, Cs, and Ag with SiC and pyrolytic carbon is studied in detail. Using the SiC single crystals and TRISO coating materials as substrates, interfaces are prepared under controlled conditions in an ultra-high vacuum environment and are studied with a photoelectron spectroscopy, Auger electron spectroscopy, Inverse Photoemission, X-ray emission spectroscopy, and X-ray absorption spectroscopy. Recent additions to the experimental approach include microscopic techniques (Transmission Electron Microscopy, Scanning Tunneling Microscopy, Atomic Force Microscopy) …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski

Fuels Campaign (TRP)

This project examines inert fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations are used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of ²³⁹Pu. Ceramics are synthesized and characterized based on the reactor physics results. The solubility of the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, are investigated in a manner to provide thermodynamic data necessary for …

Selective Growth Of Carbon Nanotubes And Oxide Nanowires: Applications In Shadow Lithography And Fabrication Of Aligned Carbon Nanotube Membranes, Nitin Chopra

University of Kentucky Doctoral Dissertations

A promising approach investigated here is to utilize thin film multilayer structures where the thickness of a catalyst layer at an exposed edge of photolithographically defined pattern determines the diameter of the nanotubes/nanowires grown from it. This can in turn be incorporated into photolithographically defined post structures resulting in an array of suspended nanowires for line-of-site shadow lithography. Success of the diameter control approach has been shown by selectively growing carbon nanotubes (CNTs) from narrow lines (12-60 nm) of SiO₂, Fe, Ni, Co on micron-scale patterned substrates in a ferrocene or nonferrocene catalyzed CVD process. In addition, the …

Modeling Of Dielectric Mixtures Containing Conducting Inclusions With Statistically Distributed Aspect Ratio, Marina Koledintseva, Sandeep K. R. Chandra, Richard E. Dubroff, Robert W. Schwartz

Electrical and Computer Engineering Faculty Research & Creative Works

An analytical model of composites made of a dielectric base and randomly oriented metal inclusions in the form of nanorods is presented. This model is based on the generalized Maxwell Garnett (MG) mixing rule. In this model, the nanorod particles are modeled as prolate spheroids with a statistically normal distribution of their aspect ratios. It is shown that parameters of the distribution laws affect the frequency characteristics of the composites both at microwave and optical frequencies. The results of computations are represented.

An Investigation Into Microwave Energy To Soften Scrap Tire Rubber Aiding Existing Mechanical Separation Processes, Russell Jon Lucas

Dissertations and Theses @ UNI

This research was performed to soften scrap tires to aid in their transformation from whole tires to valuable streams of rubber and steel for reuse in industry. Actual shredded scrap rubber was used in this experiment to determine if this highly variable material could yield consistent results if subjected to volumetric heating from a magnetron emitting microwave energy.

A consumer microwave oven was used to heat this material. This oven had its control circuitry modified by using a programmable logic controller to operate the energy exposure time. The sample's surface temperature was measured utilizing a non contact infrared thermometer. All …

Method And System For Electronically Generating Random Answers, Stephen O. Bozzone, Bonnie Bachman

Economics Faculty Research & Creative Works

The invention concerns a method (300) and system (110) for electronically generating random responses in a portable electronic device (110). The method includes the steps of detecting (316) motion of the portable electronic device, in response to the detecting step, generating (318) the random response and outputting (320) the random response to a user of the portable electronic device. The method can further include the steps of prompting (312) the user to ask a question and following a predetermined time period after prompting the user to ask the question, prompting (314) the user to shake the portable electronic device. The …

College Of Engineering Senior Design Competition Fall 2005, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Multiple Channel Laser Beam Combination And Phasing Using Stimulated Brillouin Scattering In Optical Fibers, Brent W. Grime

Theses and Dissertations

Brightness scaling lasers using stimulated Brillouin scattering (SBS) in optical fibers is explored. A multiple-channel amplifier approach is used to increase the total power of a laser system while avoiding a significant burden on a single channel. The work explores two approaches utilizing both SBS beam cleanup and SBS piston error conjugation. A unique beam combiner that takes advantage of the SBS beam cleanup properties of a long, gradient-index multimode fiber was designed and tested. The beam combiner was developed to combine multiple-channel laser beams simultaneously with high input and output coupling efficiency. The design for the SBS beam combiner …

Interactions Between Antiwear Agent And Novel Additive In Engine Oils, Kajal Parekh

Material Science and Engineering Theses - Archive

Research has shown that side/end products of phosphorus and sulfur compounds in engine oils reduce effective life of exhaust catalysts of automobiles resulting in harmful emissions. Thus environmental regulations have been imposed on phosphorus levels in engine oils. The main source of phosphorus in today's oils is the indispensable antiwear agent Zinc Dialkyl Dithiophosphate (ZDDP). To find cost-effective non-phosphorus substitute has not proven fruitful. A unique way of reducing phosphorus or ZDDP level while maintaining good antiwear performance has been achieved by introduction of a novel additive FeF3 along with ZDDP. It appears that the interactions between FeF3 and ZDDP …

A Study Of Overcharge Characteristic Of Lithium-Ion Cells, Jing Pang, Shi-Gang Lu, Sha Liu

Journal of Electrochemistry

The overcharge characteristics and effect factors of lithium-ion cells containing LiMn₂O₄ cathodes were studied in detail. Overcharge testing of Lithium-ion cells with a systematic variation in the cell balance demonstrated that the overcharge characteristics of Lithium-ion cells was affected by the amount of cathode in the cells, which is independent of the amount of anode material. The rate of charge was found to be an important parameter, as electrolyte complete decomposition at low charge rates caused the end of overcharge testing, while high charge rates accelerated the rate of heat generation in the cells and the cell …

The Deactivation Mechanism Of Metal Oxide Anodes Under Alternative Current Electrolysis Condition, Jun-Tao Wang, Yan Han, Guang-Zhang Chen, Wen-Fa Liu

Journal of Electrochemistry

The metal oxide anodes coated on titanium used in seawater electrolysis were prepared by thermal decomposition. Their morphologies, compositions and phase structures were determined by scanning electron microscope(SEM), energy dispersive X-ray detector(EDX) and X-ray diffraction(XRD). The electrochemical properties of the anodes were characterized by accelerated life test, cyclic voltammetry and electrochemical impedance spectroscopy. SEM, EDX and XRD showed that solid solution structures of (Ru, Ir, Ti)O₂ and (Ir, Ti)O₂ were formed after pyrolysis, the solid solution structures and active components were disappeared after the deactivation of the anodes. Electrochemical results indicated that the active area decreased and the …

Ferroelectric Switch For Spin Injection, Mikhail Ye. Zhuravlev, Sitaram Jaswal, Evgeny Y. Tsymbal, Renat F. Sabirianov

Materials Research Science and Engineering Center: Faculty Publications

A method for the switching of the spin polarization of the electric current injected into a semiconductor is proposed, based on injecting spins from a diluted magnetic semiconductor through a ferroelectric tunnel barrier. We show that the reversal of the electric polarization of the ferroelectric results in a sizable change in the spin polarization of the injected current, thereby providing a two-state electrical control of this spintronic device. We also predict a possibility of switching of tunneling magnetoresistance in magnetic tunnel junctions with a ferroelectric barrier and coexistence of tunneling magnetoresistance and giant electroresistance effects in these multiferroic tunnel junctions.

Solid Oxide Fuel Cells-Materials And Prospects, Molenda Janina, Marzec Jacek

Journal of Electrochemistry

The paper summarizes and discusses the basic properties of solid oxide fuel cell (SOFC) components (electrode materials and electrolyte) from the point of view of their essential functional parameters suck as chemicalstability, transport, catalytic and thermomechanical properties under operational conditions in a SOFC. An interrela-tion between the defect structure of these materials related to oxygen nonstoichiometry and their electronic propertiesand catalytic activity was shown. Single-chamber fuel cell concept was also presented.

The Optimal Sulfonation Conditions Of Self-Doped Polyaniline Obtained By Using Experimental Strategies, Wen-Yar Li, Chi-Chang Hu

Journal of Electrochemistry

The optimal sulfonation condition of self-doped sulfonated polyaniline (prepared from leucoemeraldinebase; denoted as LEB-SPANI) with a high electronic conductivity was obtained by experimental strategies, includingthe fractional factorial design (FFD) and central composite design (CCD). From the FFD experiment, the self-doped LEB-SPANI prepared at a lowtemperature (4℃), a short reaction time (1 h), and a small volume of fumingsulfuric acid (10 mL) showed a better conductivity (ca.127 mS/cm). In the CCD study coupled with a confirmationtest, the highest conductivity (ca.141 mS/cm) of the LEB-SPANI film was obtained under a sulfonation temperatureof 4℃, a sulfonation time of 75 minutes, and a volume …

A Study Of Three Corrosion Inhibitors For Reinforcing Steel In Sps Solution By Electrochemical Methods, Bing Zhao, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

Some electrochemical techniques such as linear polarization,electrochemical noise and EIS have been employedto study the inhibition behavior of N-lauroyl sarcosinate, β-sodium glycerophosphate and D-sodium gluconate for the reinforcing steel immersed in simulated concrete pore solution(SPS) with NaCl addition.The results show that D-sodium gluconatehas an obvious inhibitive effect for the reinforcing steelin containing Cl^- SPS solution. It has been proposed that the corrosion inhibition of D-sodium gluconate is due to its competitive adsorption and precipitation on steel surface in the simulated concrete environment.

Copper Electrodeposition Under The Perturbation Of Hard Particles, Zeng-Wei Zhu, Di Zhu

Journal of Electrochemistry

Copper electrodepositon was carried out on the rotating cathode,with hard particles(such as ceramic beads) filling between the electrodes. The rotation of cathode led hard particles to polish and impact the surface of deposit during electrodeposition.Copper deposits with a mass of cuspidal nodules were produced in acid sulfate solutions while brittle deposits without nodules were produced in alkaline sulfate solutions. It was also found that brightening and smoothing deposit could be obtained from the alkaline solution, and the deposit was approximatively disordered orientation with granular morphology of about 100~300 nm. The results show that the polishing and impact of hard particles …

Silicides And Composites Materials As Anodes For Lithium Ion Batteries, Jun-Mei Yan, Hui-Zhen Huang, Jing Zhang, Yong Yang

Journal of Electrochemistry

The anode materials of Mg₂Si and MnSi were synthesized by mechanically activated annealing(MAA) techniques in this work and the in electrochemical performances were also studied.A series of composite materials of Mg₂Si and CNTs or CMS were prepared by ball-milling method respectively. The reversible capacities of the composites were higher than that of the pure Mg₂Si and pure carbon materials.The cyclic performances have been improved greatly by ball-milling of the Mg₂Si and carbon materials. Results show that ball-milling method is one kind of method to make alloy materials into practical use.

Electrochemical Disinfection Method To Treat Wastewater From Hospitals, Zhi-Fu Li, Ya-Dong Tan, Ning Xu, Shao-Hong Ren, Yu Zhao

Journal of Electrochemistry

Electrochemical disinfection method was used to treat wastewater from hospitals. The mechanism of electrochemical disinfection was researched by using the different anode materials. The results showed that when the titanium coated with noble metal (Ru, Pt, Ir)oxide was used as an anode and stainless steel as a cathode, the current density was 6 mA/cm², hydraulic retention time was 15 min,air flow rate was 40 L/h, the rate of anode effective area to the inner water volume was 1.0, the amount of total colibacillus was below 500 CFU/L after electrochemical disinfection,All these meet the first order of Effluent Discharge …

A Continuous Operation For Electroreduction Of Oxalic Acid To Glyoxylic Acid, Xiao-Hui Hu, Xiang-Fei Yan, Yu-Zhong Su, Jun Li, Qing-Biao Li

Journal of Electrochemistry

A simulative-continuous-operation approach was proposed to study the continuous operation for electroreduction of oxalic acid to gloxylic acid using a packed bed reactor and a parallel reactor with cooled cathode in order to solve the low productivity problem in current state by using traditional reactor. The effects of the concentration of oxalic acid and temperature on this process were also studied. Results showed that,after 30min of the reaction(residence time), the mass fraction of the produced glyoxylic acid in the catholic solution could reach 3.76% and 3.66% with respect to a saturated oxalic acid method and a step-temperature decreasing method. From …

The Mechanism Of Ethylenediamine On Electroless Ni-B Alloy Deposition, Sen-Lin Wang

Journal of Electrochemistry

The effects of ethylenediamine stabilizer on the deposition rate and on the stability of the plating bath for electroless deposition of Ni-B alloy were investigated. It was found that the addition of ethylenediamine greatly enhances the stability of the electroless plating bath. The electrochemical polarization including cathodic and anodic polarizations measurements were carried out to examine the effect of ethylenediamine on the deposition process. The results show that ethylenediamine affects both the cathodic and the anodic polarization processes. The oxidation current of the reducer and the reduction current of Ni-B alloy decrease greatly when ethylenediamine was added into the plating …

Electrochemical Controllable Preparation Of Hydroxyapatite Coating With Different Morphologies And Preliminary In Vitro Tests, Hai-Yan Shi, Ren Hu, Chang-Jian Lin

Journal of Electrochemistry

The Controllable electrochemical deposition has been developed to prepare the hydroxyapatite(HA) coatings on Ti substrate with different morphologies and structures. Three kinds of typical topography of HA coatings, i.e. standing-up, flower and ordered porous structures have been obtained. The XRD and FTIR results demonstrate high crystallinity of the coating and exclusion of other forms of calcium phosphates. In vitro tests reveal that the biological property is largely dependent on the structure and morphology of the HA coating. It has been found that all pure HA coating show good biocompatibilities, while only the HA coating with ordered porous structures exhibits best …

Electrochemical Oxidation Of Organic Additives In Tin Plating Electrolytes, Yin-Mei Cheng, Lan-Kun Cai, Qiang Song

Journal of Electrochemistry

Cyclic voltammetry(CV) was used to characterize the voltammetric behaviours of organic additives, e.g. PSA(phenolsulfonic acid) EN(ethoxylatedα-naphthol) and ENSA(ethoxylatedα-naphthol sulfonic acid), on the anode surface. In PSA solutions, an anodic peak was obtained and the peak potential was about 1.2V. In EN and ENSA solutions, two anodic peaks were obtained and the peak potentials were about(0.95V) and 1.3V. The products of galvanostatic electrolysis were separated by HPLC(high performance liquid chromatography) and analyzed by EI/MS(electron ionizing mass spectrometry). The mechnism of the electrochemical oxidation was also disussed.

The High Temperature Corrosion Of 2205 Duplex Stainless Steel With Nacl Deposit, Fu-Fu Peng, Chaur-Jeng Wang, Yu-Chang Lin

Journal of Electrochemistry

The objective of this study was to figure out the hot corrosion behavior of 2205 duplex stainless steel (2205 DSS) within the temperature ranges from 550 to 850℃ in the static air condition with 2 mg/cm² NaCl deposit, and in the air atmosphere condition with a constant flow rate of 500 vppm NaCl_(g), respectively. Experimental results show that the hot corrosion kinetics met the parabolic rate law and the corrosion rate increased constantly with increasing temperature. The scales formed included Fe₂O₃/Fe₃O₄/Cr₂O₃ and FeCr₂O_{4 …}

Effect Of Hco3- Concentration On Co2 Corrosion In Gas And Oil Fields, Guo-An Zhang, Min-Xu Lu, Yin-Shun Wu

Journal of Electrochemistry

The effecs of HCO₃^- concentration on CO₂ corrosion in gas and oil fields were investigated by carrying out potentiodynamic scans and weight loss tests.Potentiodynamic polarization curves showed that the cathodic current density decreased with cm increase of HCO₃^- concentration when HCO₃^- was lower than 0.042(mol/L). The cathodic reations were promoted by increasing HCO₃^- when it reached 0.126 mol/L, Anodic behavior was an active process at low er [HCO₃^-] concentration and the anodic current density decreased with the increase of [HCO₃^-] concentration. An evident active-passive behavior …

An Electrochemical Study Of Electroless Copper Plating Using Glyoxylic Acid As Reducing Agent, Li-Qiong Wu, Fang-Zu Yang, Ling Hang, Shi-Gang Sun, Shao-Min Zhou

Journal of Electrochemistry

The electroless copper plating using glyoxylic acid as a reducing agent,Na₂EDTA as a chelating agent and K₄FeCN₆ and 2,2'-dipyridyl as additives was studied. The effect of chelating agent and addtives on the polangation behaviovs of copper reduction and glyoxylie acid oxidation were analyzed by linear sweep voltammetry. The results mainly demonstrated that the chelating agent hindered both the oxidation of glyoxylic acid and the reduction of copper complexing ions. It has revealed that K₄FeCN₆ and 2,2'-dipyridyl (with the content over than 20 mg/L) both played negative actions on the oxidation of glyoxylic …

The Electrocatalystic Investigation Of 3,4-Dihydroxybenzoic Acid On The Modified Multiply Wall Carbon Nanotubes, Ming-Qi Li, Duo-Chang Cai, Xiao-Ying He

Journal of Electrochemistry

The electrochemical behavior of 3,4-Dihydroxybenzoic acid(DHBA) on modified multiply wall carbon nanotubes electrode was investigated by cyclic voltammetry(CV) and square wave voltammetry(SWV). Results show that in 0.1 mol/L HCl solutions the modified carbon nanotube electrode has an obvious electrocatalytic effect on the oxidation and deoxidization of DHBA. The oxidation current of DHBA is linear to it's concentration in the range of 4.0×10^-6～1.0×10^-4 mol/L and 2.0×10^-4～8.0×10^-4 1mol/L with correlation coefficient of 0.9995 and 0.9992. The detection limit is 1.0×10^-6 mol/L.