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University Of Nevada, Las Vegas Transmutation Research Program Annual Report Academic Year 2005-2006, Anthony Hechanova, Rebecca Arbour

Transmutation Research Program Reports (TRP)

It is my pleasure to present the UNLV Transmutation Research Program’s fifth annual report that highlights the academic year 2005 – 2006. Supporting this document are the many technical reports and scientific papers that have been generated over the past five years.

In the fifth year of our program, we saw amazing growth in the Radiochemistry Ph.D. program with a total of 12 students in the second year of the program (twice the number we anticipated in the program proposal). In the back of this issue, under Infrastructure Augmentation, you will find some news about the new academic programs sponsored …

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 …

Solution-Based Synthesis Of Nitride Fuels, Kenneth Czerwinski, Thomas Hartmann

Fuels Campaign (TRP)

A wide variety of fuel concepts are considered for advanced reactor technology including metals, metal oxides or metal nitrides as solid solutions or composite materials. Nitride fuels have appropriate properties for advanced fuels including high thermal conductivity, thermal stability, solid-state solubility of actinides, fissile metal density, and suitable neutronic properties. A drawback of nitride fuels involves their synthesis. A key parameter for preparing oxide fuels is the precipitation step in the sol-gel process. For nitride fuels, the current synthetic route is carbothermic reduction from the oxide to the nitride. This process step is based on solid phase reactions and for …

Growth Of Ge Quantum Dots On Si(100)-(2×1) By Pulsed Laser Deposition, M. S. Hegazy, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Self-assembled germanium quantum dots (QDs) were grown on Si(100)-(2×1) by pulsed laser deposition. In situ reflection-high energy electron diffraction (RHEED) and postdeposition atomic force microscopy are used to study the growth of the QDs. Several films of different thicknesses were grown at a substrate temperature of 400 °C using a Q-switched Nd:yttrium aluminum garnet laser (λ= 1064 nm, 40 ns pulse width, 23 J/cm ² fluence, and 10 Hz repetition rate). At low film thicknesses, hut clusters that are faceted by different planes, depending on their height, are observed after the completion of the wetting layer. With increasing film thickness, …

Atr-Ftir Spectroscopic Analysis Of Sorption Of Aqueous Analytes Into Polymer Coatings Used With Guided Sh-Saw Sensors, Yolanda K. Jones, Zhonghui Li, Michael M. Johnson, Fabien Josse, Jeanne Hossenlopp

Chemistry Faculty Research and Publications

Attenuated total internal reflectance Fourier transform infrared (ATR-FTIR) spectroscopy was used for the investigation of sorption of aqueous solutions of analytes into polymer coatings. A series of simple model polymers, such as poly(dimethylsiloxane), poly(epichlorhydrin), and poly(isobutylene), and films and analytes, such as aqueous solutions of ethylbenzene, xylenes, toluene, and nitrobenzene, were used to evaluate the use of ATR-FTIR spectroscopy as a screening tool for sensor development. The ratios of integrated infrared absorption bands provided a simple and efficient method for predicting trends in partition coefficients. Responses of polymer-coated guided shear horizontal surface acoustic wave (SH-SAW) sensor platforms to the series …

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 …}

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 …

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.

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.

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 Investigation On Poly(Vinyl Chloride-Co-Isobutyl Vinyl Ether) Coatings Modified By Rutile Nano-Tio2 Pastes, Xiang Bin, Sheng-Tao Zhang, Yan Li, Bao-Rong Hou

Journal of Electrochemistry

The anti-corrosion coating of Poly(Vinyl Chloride-Co-Isobutyl Vinyl Ether) (PVCCIVE) was modified by rutile nano-TiO₂. The influence of nano-TiO₂ pastes on the coating's corrosion resistance was investigated through electrochemistry impedance spectroscopy (EIS). The results show that the addition of nano-TiO₂ pastes does not have obvious effect on the coating's performance of adhesion, flexility, impact resistance, but improves the coating's UV resistance and the gloss.Meanwhile,with the proper addition of rutile nano-TiO₂ pastes, the anti-corrosion behavior of the coating was advanced.

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 …

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.

Afci Quarterly Input – Unlv July 1 Through September 30, 2005, Harry Reid Center For Environmental Studies. Nuclear Science And Technology Division

Transmutation Research Program Reports (TRP)

Quarterly report highlighting research projects, activities and objectives of the Transmutation Research Program at the Nuclear Science & Technology Division, Harry Reid Research Center.The University of Nevada, Las Vegas supports the AFCI through research and development of technologies for economic and environmentally sound refinement of spent nuclear fuel. The UNLV program has four components: infrastructure, international collaboration, student-based research, and management and program support.

Nafion Emulsion Method For Fuel Cell Membrane-Electrode-Assembly Preparation, Chao-Yang Xia, Lin Zhuang, Jun-Tao Lu

Journal of Electrochemistry

A Nafion emulsion method for fuel cell membrane-electrode-assembly (MEA) preparation was reported for the first time in this paper. 5 %(by mass) Nafion alcohol solution and non-polar solvent (e.g., cyclohexane) were ultrasonicallymixed to produce Nafion emulsion. The catalyst ink prepared using the thus-obtained Nafion emulsion can be directly cast onto Nafion membrane to make MEA. This method is simple in operation, and effectively preventsthe Nafion membrane swelling, hence is suitable for large-scale application. The MEA thus-prepared showed comparable catalyst efficiencywith respect to the popular transfer-method, and the preliminary performance in room-temperature H₂/O₂ fuel cell test was satisfying.

Surface And Sructure Investigations Of Membrane Electrode Assembly In Dmfc Lifetime Testing, Xuan Cheng, Cheng Peng, Meng-Di You, Jing Liu, Ying Zhang

Journal of Electrochemistry

The lifetime and performance of a direct methanol fuel cell (DMFC) were investigatedto understand the correlation between thestructure of catalysts/membrane and cell performanceversus time. The cell polarization and performance curves were obtained during the DMFC operation with the time. The catalysts and Nafion membrane of the membrane electrode assembly (MEA) from the lifetime test were comprehensively examined by XRD, HRTEM, FTIR and Raman spectroscope techniques. The results revealed that there was significant performance degradation during the first 200 hours operation; while the degradation was slowing down between 200 and 704 hours operation. The degradation became worse after 1002 h operation. …

Adsorption Of Polyaspartic Acid From Sulphur Acid Solution On Carbon Steel And Its Corrosion Inhibition, Rong-Jing Cui, Ning Gu, Chun-Mei Li

Journal of Electrochemistry

The role of Polyaspartic acid in the corrosion inhibition of 45# carbon steel in sulphuric acid solution has been investigated by polarization curve andelectrochemical impedance spectroscopy (EIS). The influences of the concentration and the temperature of PASP on the corrosion inhibition efficiency were determined. The results indicated that the PASP as the corrosion inhibitor mainly inhibitated the anode; within the experiment temperature, the inhibitor efficiency decreased with the raising of the temperature and PASP had a good inhibiting performance at 10℃, the corrosion inhibition efficiency of PASP for carbon steel increased with the increase of the concentration of PASP when …

Effect Of Chloride Ions On The Corrosion Behavior Of Reinforcing Steel In Simulated Concrete Pore Solutions, Yu Liu, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The potentiodynamic anodic polarization was used to study the corrosion behavior of the reinforcing steel in simulated concrete pore solutions with different pH and chloride ion concentrations. The effect of chloride ions on passivity breakdown of the steel was examined by measuring the breaking potentials of reinforcing steel, and the critical chloride concentrations for depassivation were found in simulated concrete pore solutions at pH 12.50 and pH 12.00.

Research Progresses In A Flow Redox Battery, Quan-Feng Dong, Hua-Min Zhang, Ming-Gang Jin, Ming-Sen Zheng, Ya-Ding Zhan, Shi-Gang Sun, Zu-Geng Lin

Journal of Electrochemistry

As a large scale electrochemical storage device, flow redox battery in which the active materials are flowing electrolytes is different from the common batteries employing solid or gas materials as an electrode. In this paper we introduced flow redox battery in brief, reviewed its development and actual state on (study). The main problem existed in the new device was discussed when viewed with its future developments.