Engineering Commons^™

Diffusion Of Hydrogen At Iron Apply For Electrochemical Oscillating Permeation, Li Zhang, Ren-He Yin, Zhan-Mei Sun

Journal of Electrochemistry

The diffusion of hydrogen in iron was measured using electrochemical oscillating permeation. Through the samples in the different frequencies, it was found that diffusion of hydrogen at iron is of linear relation with boundary condition, which is the key to Fick's diffusion equation amplitude in the liquor. We can exploit this line relation getting the diffusion of hydrogen at iron.

Research Progress On Electrode Material In All-Vanadium Redox Battery, Hua Li, Shou-Wen Chang, Chuan-Wei Yan

Journal of Electrochemistry

An all-vanadium redox flow storage battery possesses many advantages over conventional storage batteries.The development statue of two types electrode materials (metal and compound type) is introduced in this article.

Initial Stages Of Copper Electrodeposition On Glassy Carbon Electrode, Ling Huang, Rui Zhang, Min Gu, Fang-Zu Yang, Shu-Kai Xu, Shao-Min Zhou

Journal of Electrochemistry

Initial stages of copper electrodeposition on glassy carbon electrode from acid sulphate solutions were studied using cyclic voltammetry and chronoamperometry. The electrolyte solution was a 0.05 mol.L^-1 copper sulphate, 1.4～1.8 mol⋅L^-1 sulphuric acid containing 1 mg·L^-1 2-mercaptobenzoimidazole, Results show that 2-mercaptobenzoimidazole produced an inhibition of the copper deposition, probably related to the adsorption,sulphuric acid promote copper electrodeposition. The initial deposition kinetics corresponded to a model including instantaneous nucleation and diffusion controlled growth.Addition of 2-mercaptobenzoimidazole and sulphuric acid did not change the initial nucleation of copper electrocrystallization, it increased the nucleation rate and the number density of nuclei …

Xrd Study On Highly Preferred Orientation Cu Electrodeposit, Min Gu, Fang-Zu Yang, Ling Huang, Shi-Bing Yao, Shao-Min Zhou

Journal of Electrochemistry

Copper electrodeposit was obtained in CuSO₄+H₂SO₄ electrolyte solution by electrodeposition and its structure was studied by XRD. The results showed that copper electoddeposits with the highly preferred orientations of (220) and (111) could be obtained at current density 4.0 A/dm² and 15.0 A/dm², respectively. The texture coefficient (TC) values were increased by thickness of Cu deposits. The thickness would be, to obtain Cu electrodeposit with (111) highly preferred orientation, about 7 times of that of (220) highly preferred orientation, which indicated that(220) face was easier to be remained than (111) face and …

Ionic Conduction In Ba0.95Ce0.9Y0.1O3 - Α Solid Oxide And Its Performance In Fuel Cell, Gui-Lin Ma, Ding-Xian Jia, Li-Gan Qiu, Hui Shi, Rong Chen

Journal of Electrochemistry

Using Ba_0.95Ce_0.9Y_0.1O_3-α as a solid electrolyte and porous platinum as electrodes,hydrogen and oxygen concentration cells and hydrogen-air fuel cell were constructed, respectively. Electromotive forces (MEFs) of the gas concentration cells and I-V characteristics of the fuel cell were detdrmined in the temperature range of 600～1 000 ℃. The Ba_0.95Ce_0.9Y_0.1O_3-α exhibited almost the pure protonic conduction under hydrogen gas,and a mixed conduction of oxide-ion and electron hole with oxide-ion transport number of 0.3～0.5 under oxygen gas. It exhibited a mixed conduction of proton and oxide-ion with the …

Modification Of Molybdenum Nitride Electrode For Supercapacitor(I)——The Effect Of Ammonium Vanadate On The Properties Of Molybdenum Nitride Electrode, Xue-Liang Li, Dao-Rong Luo, Hua-Lin Wang, Jian-Bo He, Yun-Guei Zhu

Journal of Electrochemistry

The effect of vanadium on the properties of the electrode of molybdenum nitride has been studied by using XRD, SEM and cyclic voltammetry. Modified molybdenum nitride was made as follow: films were coated by dipping titanium sheet in the solution containing different composition of molybdenum oxide, ammonium vanadate, ammonia, glycol and oxalic acid, and coated films are reacted with free ammonia. The results show that the specific capacitance of modified electrode was considerably increased and the operation voltage was broadened with the addition of ammonium vanadate in the dipping solution. The mechanism of these effects generated is the formation of …

Pure Hap Film Prepared By Direct Electrodepositing On Metallic Surface And Its Mechanism, Hao-Bing Hu, Chang-Jian Lin, Fei Chen, Ren Hu, Ming Guo

Journal of Electrochemistry

In controlling concentration of Ca²⁺ and PO₄^3- in electrodeposition solution, the HAP film on Ti alloy has been deposited directly. Using XRD and SEM we have learned that prepared HAP is intact in crystal and equal in dimension. Thermodynamic calculation indicated that the HAP is easer formation of than that TCP of. With the XRD, SEM analyses and thermodynamic calculation, the electrodeposition mechanism has been discussed. It was proved that electrodepositon is a two-stage process and formation of HAP is a direct process from solution ions to HAP crystal without precursor.

Some Consideration For Lithium-Ion Cells' Safety, Guang-Xia Hu, Jing-Ying Xie

Journal of Electrochemistry

The safety is the most important problem for lithium ion cells, especially for large lithium ion cells. In this paper, some information about lithium ion cells' safety can be learned by discussing several aspects of lithium ion cells, such as, materials of lithium ion cell, manufacturing processes, using conditions and so on.

Study On Hydrogen Evolution Performance Of Nickel-Tin Electrode, Tian-Yi Chang, Bao-Hong Zhang, Wenbo Cong, Yao Luo

Journal of Electrochemistry

The cathode active material with low hydrogen evolution overvoltage was prepared by electroplating Ni-Sn alloy on the ferrous basic body.This kind of material can be applied in the diaphragm type of electrolytic tank to decrease cell voltage and save energy. On the condition according with cathode solution in the electrolytic tank (NaOH 120 g/L, NaCl 190 g/L, 90 ℃, i=150 mA/cm²), the overvoltage of hydrogen evolution was 88 mV. By the X-ray diffraction analysis, it was found that the structure of this kind of material was different from that of Ni-Sn alloy applied in traditional decoration. By using …

Electrochemical Degradation Of Organic Wastewater By Three-Dimensional Electrode Reactor, Chun He, Tai-Cheng An, Ya Xiong, Dong Shu, Hui-Ling Hu, Xi-Hai Zhu

Journal of Electrochemistry

The electrochemical degradation of aniline was investigated using a novel electrochemical reactor, three-dimensional electrode reactor. The experimental results indicated that the reactor could efficiently remove aniline. The removal efficiency could be attributed to a combination of direct and indirect electrochemical reactions, that is, anodic oxidation and oxidation of electrogenerated H₂O₂ and hydroxyl radicals generated in electro-Fenton process. It was also observed that the removal efficiency was significantly dependent on applied voltage, Fe²⁺ concentration, pH value and electrolysis time. In the experimental range they all have a positive effect on the removal efficiency except for pH value. …

Dielectric Properties Of A Ferroelectric Copolymer Langmuir–Blodgett Film, Mahantappa S. Jogad, Stephen Ducharme

Stephen Ducharme Publications

We report measurements of the real (epsilon prime) and imaginary (epsilon double-prime) parts of the relative complex permittivity of a Langmuir–Blodgett film of ferroelectric copolymer of vinylidene fluoride (70%) with trifluoroethylene (30%). The measurements were made in the temperature range of 35 to 125° C, and frequency range of 19 Hz to 5 MHz. The results indicate low frequency loss due to conduction and dielectric loss peak near the ferroelectric–paraelectric phase transition.

Field Guide To The Geology Of The Harlan County Lake Area, Harlan County, Nebraska, With A History Of Events Leading To Construction Of Harlan County Dam, Robert F. Diffendal Jr., Duane R. Mohlman, R. George Corner, F. Edwin Harvey, K. J. Warren, Scott Summerside, Roger K. Pabian, Duane A. Eversoll

School of Natural Resources: Faculty Publications

The year 2002 will mark the fiftieth anniversary of completion of the Harlan County Dam and Multi-Purpose Reservoir. This seems a good time to write about the history of and reasons for building the dam, the effects of the dam and reservoir on the Republican River valley, and the geologic features seen along the shores of the lake and areas nearby. As many junior authors helped produced this educational circular, they are listed in the table of contents. All other sections were written by the senior author.

Includes July 2016 update: Addendum of photographs showing fault traces on drought-exposed lake …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 5/16/02- 8/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

Two activities are proposed in this Phase I task: the development of systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model is the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project is to streamline and improve an integral part of the overall systems model, which is the software package AMUSE. AMUSE analyzes the UREX process and other related solvent extraction processes and defines many of the process streams that are integral to …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides: Quarterly Progress Report 5/16/02- 8/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

An important aspect of the Advanced Accelerator Applications (AAA) program is the development of a casting process by which volatile actinide element (i.e., americium) can be incorporated into metallic alloy fuel pins. The traditional metal fuel casting process uses an inductively heated crucible.

This process works well for the fabrication of metal fuel pins traditionally composed of alloys of uranium and plutonium, but does not work well when highly volatile actinides are included in the melt. The problem occurs both during the extended time period required to superheat the alloy melt as well as when the chamber must be evacuated. …

Object-Oriented Modeling And Fauly Detection Of A Powder Feeder For A Laser Metal Deposition System, Robert G. Landers, Michael Gene Hilgers, Frank W. Liou, Bruce M. Mcmillin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

One of the most critical components of a laser metal deposition system is the powder feeder unit. Techniques are required to efficiently design and analyze these systems and to ensure fault tolerance during the operation. In this paper, a model of the powder feeder unit, based on object- oriented abstractions of it components, is developed. This model is modular in that specific components can be efficiently updated or replaced with components that perform a similar function. In addition, the model can be used for simulation allowing for efficient design and analysis. Assurance of the correctness of the powder feeder system …

Object-Oriented Modeling And Fault Detection Of A Powder Feeder For A Laser Metal Deposition System, Robert G. Landers, Michael Gene Hilgers, Frank W. Liou, Bruce M. Mcmillin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

One of the most critical components of a laser metal deposition system is the powder feeder unit. Techniques are required to efficiently design and analyze these systems and to ensure fault tolerance during the operation. In this paper, a model of the powder feeder unit, based on object-oriented abstractions of it components, is developed. This model is modular in that specific components can be efficiently updated or replaced with components that perform a similar function. In addition, the model can be used for simulation allowing for efficient design and analysis. Assurance of the correctness of the powder feeder system is …

Corrosion Of Steel By Lead Bismuth Eutectic: Quarterly Report For May-June-July 2002, John Farley

Transmutation Sciences Materials (TRP)

The goal of this project is to understand the basic science of corrosion in the steel/LBE system.

We are taking more data, typically using the newly installed X-ray Photoelectron Spectrometry (XPS) apparatus, and analyzing our existing data. Undergraduate students Denise Parsons and Julia Manzerova have helped a great deal in the analysis of the data. We can obtain the elemental composition as a function of position within the sample. This gives clues to the migration of materials, the composition of the protective oxide layer, and the basic science of the corrosion process. We found dramatic differences between the exposed and …

Design And Analysis For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Xiaolong Wu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fundamental issues related to the selection of a metallic fuel casting furnace design are presented and discussed including heating mechanisms, casting issues, crucible design, and issues related to the mass transport of americium. The process of evaluating all of these different criteria is undertaken to select a concept that would have the greatest chance of success for casting americium in a metallic fuel rod. Based on this evaluation process, a concept for the casting of metallic fuel pins containing high vapor pressure materials is selected and discussed. The important physics of this concept include mass transport of americium from the …

Organizing And Personalizing Intelligence Gathering From The Web, Hwee-Leng Ong, Ah-Hwee Tan, Jamie Ng, Pan Hong, Qiu-Xiang Li

Research Collection School Of Computing and Information Systems

In this paper, we describe how an integrated web‐based application, code‐named FOCI (Flexible Organizer for Competitive Intelligence), can help the knowledge worker in the gathering, organizing, tracking and dissemination of competitive intelligence (CI). It combines the use of a novel user‐configurable clustering, trend analysis and visualization techniques to manage information gathered from the web. FOCI allows its users to define and personalize the organization of the information clusters according to their needs and preferences into portfolios. These personalized portfolios created are saved and can be subsequently tracked and shared with other users. The paper runs through an example to show …

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic: Quarterly Progress Report (May 01 – July 31, 2002), Yingtao Jiang, Bingmei Fu, Woosoon Yim

Transmutation Sciences Materials (TRP)

Accurate measurement of the oxygen concentration in liquid Lead-Bismuth Eutectic (LBE) cooling system is critical in the active control of the corrosion at the interface between LBE and the stainless steel of transport tubes. Currently, LANL (Los Alamos National Laboratory) scientists have employed an automobile-style YSZ (Yttria Stabilized Zirconia) oxygen sensor unit to measure oxygen levels in an engineeringscaled LBE test system. Although the theoretical model for calculating oxygen concentration based on voltage measurement of YSZ sensor in static conditions is well understood, there is an urgent and strong need to obtain a complete set of calibration curves for YSZ …

44th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 44th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Denver, Colorado, July 28 - August 1, 2002.

Integrating Local Search And Network Flow To Solve The Inventory Routing Problem, Hoong Chuin Lau, Q Liu, H. Ono

Research Collection School Of Computing and Information Systems

The inventory routing problem is one of important and practical problems in logistics. It involves the integration of inventory management and vehicle routing, both of which are known to be NP-hard. In this paper, we combine local search and network flows to solve the inventory management problem, by utilizing the minimum cost flow sub-solutions as a guiding measure for local search. We then integrate with a standard VRPTW solver to present experimental results for the overall inventory routing problem, based on instances extended from the Solomon benchmark problems.

Content Aware Request Distribution For High Performance Web Service: A Performance Study, Robert M. Jones

Dissertations and Theses

The World Wide Web is becoming a basic infrastructure for a variety of services, and the increases in audience size and client network bandwidth create service demands that are outpacing server capacity. Web clusters are one solution to this need for high performance, highly available web server systems. We are interested in load distribution techniques, specifically Layer-7 algorithms that are content-aware. Layer-7 algorithms allow distribution control based on the specific content requested, which is advantageous for a system that offers highly heterogenous services. We examine the performance of the Client Aware Policy (CAP) on a Linux/Apache web cluster consisting of …

Phase I: Design And Analysis Of A Process For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

The proposed research would be conducted in 3 phases. Each of the phases would be carried out over a one-year period. Phase I includes model development, analysis, and the selection of a new casting furnace design. The work discussed in this report was completed as Phase I. Phase II of the program will lead to more modeling and validation to evaluate the proposed furnace concept. Phase III would be a joint effort between UNLV and Argonne National Laboratory (ANL) to demonstrate the acceptable use of the new furnace in a simulated remote environment.

The Phase III work would include the …

Reflection-High Energy Electron Diffraction Study Of Si(100) Homoepitaxy By Femtosecond Pulsed Laser Deposition, Mohammed S. Hegazy

Electrical & Computer Engineering Theses & Dissertations

The dynamics of femtosecond pulsed laser deposition (fsPLD) of Si(!00)-1 x I and Si(!00)-2x I homoepitaxy are studied by in situ reflection high-energy electron diffraction (RHEED) and ex situ atomic force microscopy (AFM). The effects of substrate temperature, laser fluence and the pressure of a passive gas on the Si(!00)-1 x I growth mode are discussed. It is shown that films grow following the Volmer-Weber (3D) growth mode. The substrate temperature largely affects the morphology of the grown film. Below ~ 400 °C (at laser fluence of~ 1.9 J/cm²), randomly oriented 3D clusters are grown. This is shown …

Development Of An Efficient Ti:Sapphire Laser Transmitter For Atmospheric Ozone Lidar Measurements, Khaled A. Elsayed

Electrical & Computer Engineering Theses & Dissertations

The impetus of this work was to develop an all solid-state Ti:sapphire laser transmitter to replace the current dye lasers that could provide a potentially compact, robust, and highly reliable laser transmitter for differential absorption lidar measurements of atmospheric ozone. Two compact, high-energy pulsed, and injection-seeded Ti:sapphire lasers operating at a pulse repetition frequency of 30 Hz and wavelengths of 867 nm and 900 nm, with M² of 1.3, have been experimentally demonstrated and compared to model results. The Ti:sapphire lasers have shown the required output beam quality at maximum output pulse energy, 115 mJ at 867 nm and …

Creep And Creep-Recovery Models For Wood Under High Stress Levels, Zhiyong Cai, Kenneth J. Fridley, Michael O. Hunt, David V. Rosowsky

Civil and Environmental Engineering and Construction Faculty Research

Forty small clear southern pine specimens were loaded under third-point bending to examine creep and creep-recovery behavior for wood under high stress levels. Stress levels of between 69% and 91% of the predicted static strength were applied for 23 h with 1 h allowed for recovery, and the resulting deflection vs. time behavior was studied. The experimental creep and creep-recovery behavior was modeled using modified power law functions. The results indicate that these functions provide the best fit to both primary and secondary experimental data. The empirical models can be used to simulate the viscoelastic behavior of wood under high …

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems: Annual Progress Report (May 2001 – May 2002), Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate target materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including Alloy HT-9, Alloy EP 823 and Type 422 stainless steel. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these materials are being evaluated in environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. Further, the localized corrosion behavior of these alloys …

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823: Aaa Task-10 Quarterly (03/01, 2002 –05/31, 2002) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The objective of this task is to evaluate the elevated temperature tensile properties of Alloy EP-823, a leading target material for accelerator-driven waste transmutation applications. The test material will be thermally treated prior to evaluation of its tensile properties at temperatures relevant to the transmutation applications. The deformation characteristics of tensile specimens, upon completion of testing, will be evaluated by surface analytical techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The overall results are expected to provide a mechanistic understanding of high-temperature deformation behavior of Alloy EP-823 as a function of heat treatment.

Highlights of Accomplishment

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Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report 03/16/02- 06/15/02, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the AAA proposed application. Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with very limited density. Scientists have noticed that the concentration of oxygen dissolved in the liquid alloy could control the corrosion rate of steels exposed to Pb or Pb-Bi. At high oxygen concentration, …