Chemistry Commons^™

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 …

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, …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics-Phase Two, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. The …

Development Of A Systems Engineering Model Of The Chemical Separations Process, Yitung Chen, Darrell Pepper, Randy Clarksean

Separations Campaign (TRP)

Two activities are proposed: the development of a systems engineering model and the refinement of the Argonne code AMUSE (Argonne Model for Universal Solvent Extraction). The detailed systems engineering model will be the start of an integrated approach to the analysis of the materials separations associated with the AAA Program. A second portion of the project will 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 the systems engineering model. …

Syntheses And Photoluminescence Of Zinc Oxide Polyaniline Coaxial Nanowires And Their Array, Zhi-Xin Zheng, Yan-Yan Xi, Ping Dong, Huai-Guo Huang, Jian-Zhang Zhou, Lin-Lin Wu, Zhong-Hua Lin

Journal of Electrochemistry

A novel nanomaterial, zinc oxide (ZnO) and polyaniline (PANI) coaxial nanowires and their array in the template, was synthesized using anodic aluminum oxide (AAO) membrane as template. The morphology of these coaxial nanowires was observed with transmission electron microscope (TEM). The experiments on photoluminescence (PL) of coaxial nanowires and their array in AAO membrane show that the visible emission band of ZnO shifts from 530 nm to 400 nm and the luminescence is enhanced for the coaxial nanowires array in AAO membrane,and the visible emission band shifts to a lower wavelergth (385 nm) for coatial nanowires in NaOH solution. Possible …

Electrochemical Properties Of Mixed Metal Oxide Coated Titanium Anodes In Seawater, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen

Journal of Electrochemistry

Mixed metal oxide coated titanium anodes prepared by thermal decomposition were characterized by scanning electron microscopy and electrochemical measurement, while the consumption rate of an anode was also measured in seawater. In order to examine the practical performances of mixed metal oxide-coated anodes, a simulating test on floating dock in seawater has also been carried out. The SEM results indicate that oxide layers exhibited a cracked-mud morphology which endows the anode with good electrocatalytic activity. The electrochemical measurements showed that mixed metal oxide-coated anodes exhibit excellent electrochemical activity and electrochemical stability in seawater. Owing to good corrosion resistance and low …

Development Of 200～500 W Portable Proton Exchange Membrane Fuel Cell Power System, Li-Qing Hu, Li-Rong Zhou, Zheng Li, Jian-Wei Xia, Ming-Zhu Fu, Xin Wu, Yun Zhu

Journal of Electrochemistry

The Properties of the Portable PEM Fuel Cell Power Source are very unique compared with the common primary or rechargeable electro-chemical battery. This paper describes the In this work, of the 200～500 W portable PEM fuel cell power system, was developed. The system mainly composed of four subsystem: 1)Fuel cell stack; 2)Air delivery; 3)Hydrogen source; 4)Heat dissipation and system control.

Studies On Sulfate Reducing Bacteria Influenced Corrosion Of 90/10 Cu/Ni Alloy, Guang-Zhou Liu, Jian-Hua Qian, Yan Ma, Jian-Hua Wu

Journal of Electrochemistry

Electrochemical techniques such as measurements of corrosion potential,the polarization resistance, and potentiodynamic scanning technique were used to investigate the electrochemical behavior of 90/10 Cu/Ni alloy in Postgate C medium containing sulfate reducing bacteria(SRB). The results showed that the corrosion potential of the alloy changed from -0.20 to -0.75 V(SCE) when bacteria inocula was added, and the polarization resistance R_p decreased obviously, which corresponds to an increased corrosion rate. The shape ofthe anodic polarization curves was drastically changed in the presence of SRB, and an active-passive transition was observed. Electron probe microanalyzer was used to investigate the morphology and chemical …

Self-Assembled Monolayer Of Schiff Bases On Au Electrode, Ke-Qiang Ding, Qing-Fei Wang, Zhen-Bin Jia, Na Tian, Ning Wang, Ru-Ting Tong, Xin-Kui Wang, Hui-Bo Shao

Journal of Electrochemistry

Schiff bases tailored with -SH group, was self-assembled on Au substrate for the first time. The packing degree of this monolayer was described with SEM technique. Spontaneously, the self-assembled monolayer (SAM) was briefly characterized with CV and EIS methods. Though Comparing with the SAM of alkanethiol, the membrane we fabricated was relatively loose, our work is the first step to study Schiff bases by means of self-assembled monolayer.

Effect Of Cl- On The Transition Current Density Of Zn During The Electrodeposition Of Zn-Ni Alloys, Ren-He Yin, Zheng-Hua Fang, Wei-Min Cao

Journal of Electrochemistry

There exists a transition current density of Zn when the normal co-deposition of Zn-Ni alloys at chloride baths turns to anomalous type. The value increases with Cl^- concentration, but is independent of pH, this is because the existence of Cl^- decreases the evolution overpotential of Ni metal and has a catalytic effect on it.

The Preparation And Characterization Of Growing Preferentially Cds Nanopartile Film, Huai-Guo Huang, Yan-Yan Xi, Zhi-Xin Zheng, Jia-Wei Yan, Jian-Zhang Zhou, Ling-Ling Wu, Zhong-Hua Lin

Journal of Electrochemistry

CdS nanoparticle films were prepared on the PANI film, PATP film, Au film and ITO respectively by constant current deposition or current impulse method, and their structure and character were also studied. The results show that the substrates influence the structure and character of CdS particle film.

An Investigation On Sr-Doped Spinel Phase-LisrXMn2-XO4, Hui Zhan, Yun-Hong Zhou

Journal of Electrochemistry

Sr-doped spinel phase-LiSr_xMn_2-xO₄ was successfully prepared by solid-state method. Structural and electrochemical characterizations were carried out. Although Sr²⁺ has a large ion radius-1.12 , the spinel structure can be well maintained for LiSr_xMn_2-xO₄ sample as far as the x value doesn't surpass 0.05. Electrochemical study presents supporting evidence that doping the stoichiometric LiSr_xMn_2-xO₄ phase with Sr is an effective way to improve the cycleability of LiSr_xMn_2-xO₄ spinel material. A remarkable enhancement of the cycleability with retention of the initial …

Polishing Rate And Dependent Factors Of Copper In Nh3 ·H2O Aqueous Solution Containing K3Fe(Cn)6 During Cmp, Han-Wei He, Yue-Hua Hu, Ke-Long Huang

Journal of Electrochemistry

Dependence of polishing rates of copper on concentrations of NH₃·H₂O, passivator K₃[Fe(CN)₆], γ-Al₂O₃ abrasives and polishing pressures, polishing rotative rates were studied. Dependent mechanisms were explained. It was shown a linear relation between polishing and polishing pressures and rotative rates within some range, non-linear relation between polishing and various reagent concentrations. Preston coefficient was varied. CMP recipe of the best polishing rate was gained: 4%K₃Fe(CN)₆+1%NH₃·H₂O+25%γ-Al₂O₃, K_p=0.02383. Technics conditions were 300 rpm and 80 kpa. The …

Electrosynthesis Of Glyoxylic Acid In A Cooled Cathode Reactor, Jin-Hong Fan, Jun Li, Xue-Yun Chen, Wei Li, Hao-Qi Gao

Journal of Electrochemistry

Glyoxylic acid was produced by electroreduction of oxalic acid in a well designed cooled cathode reactor. The cathodic and anodic electrolytes were super-saturated oxalic acid and hydrochloric acid aqueous solutions separated by a super-acid ion-exchange membrane. The current efficiency and time-space yield of glyoxylic acid were studied under different temperatures of cathode and electrolyte, current densities, materials of cathode. With the cooled cathode reactor, the energy consumption was reduced and higher oxalic acid concentration was available in solution, so that current efficiency was improved. The results indicated that the average time-space yield of glyoxylic acid was about 0.032 kg·dm^{-3 …}

Corrosive Electrochemical Behavior Of Carbon Steel In Microbiological Medium, Jing Liu, Hong-Bo Fan, Hai-Ping Xu, Jia-Shen Zheng, Li-Ming Xu, Zong-Qiang Mao

Journal of Electrochemistry

Sulfate-reducing bacteria (SRB)grows and propagates, PH of the solution is dropped from 7.5 to 5.8, and forms the biofilms on carbon steel in culture medium. The micro-environment on the surface of carbon steel is changed under the biofilms, the factors accelerate the formation of the pitting corrosion. When the biofilm on carbon steel is cleaned out, the surface of carbon steel have the non-uniform pitting corrosion. The activity of SRB and the porous structure of biofilms induced the initiation and development of the pitting corrosion of carbon steel. The process of microbiologically induced corrosion (MIC) involves the development of SRB …

Electrocatalytic Oxidation Of Formaldehyde On The Proline Film Modified Electrode, Yu-Rong Ma, Qiu-Xia Yang, Guo-Bao Li, Zheng-Kai Xi, Xue-Lin Wang

Journal of Electrochemistry

The proline film modified electrode and its electrochemical behavior was studied by cyclic voltammetry and spectroelectrochemistry. After incorporation of Ni(Ⅱ), the cyclic voltammograms of the proline Ni(Ⅱ) film electrode exhibited a typical redox peak, which appeared at potential of 0.52 V anodic and 0.44 V cathodic in NaOH. The formal potentials E' were linearly dependent on the pH, and the peak currents ip were linearly dependent on the square root of the scan rates, thus charge transfer in the film was controlled by diffusion. The diffusion coefficient is figured out to be 2×10^_-10 cm²·s^-1. The …

Preparation,Structure And Properties Of Electrochromic Rhodium Oxide Films, Hai-Hong Wang, Tao Wang, Man-Ming Yan, Zhi-Yu Jiang

Journal of Electrochemistry

Electrochromic rhodium oxide films were prepared on ITO substrate by sol-gel method. The films exhibited reversible two-color (bright yellow at reduction and dark green at oxidation) electrochromic behavior in alkaline solution with good cycle stability. In-situ XRD, TGA-DTA, IR, XPS methods were used for studying the structure and chemical process of the films. The diffusion coefficient during the electrochromic process was measured by electrochemical impedance spectra method. It was found that the rhodium oxide films may be suitable for the use in electrochromic devices.

Recent Developments In The Electrolyte For Lic6/Electrolyte/Cathode Battery, Cui-Ying Wang, Sheng-Liang Zhao, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

We present a reviewed the development and status of electrolyte for LiC 6/electrolyte/cathode battery. The effect of the salt, solvent, additive and impurity on the conductivity of the electrolyte, formation of the solid-electrolyte-interphase (SEI) and cycle life of the battery were described.

A Blend Conducting Membranes For Direct Methanol Fuel Cells, Lei Li, Jun Zhang, Hong Wu, Yu-Xin Wang

Journal of Electrochemistry

An attempt was made to modify membranes for direct methanol fuel cells by blending Nafion or polystyrene sulfonic acid (PSSA) with polyvinylidene fluoride (PVDF) from their solutions. The proton conductivity and methanol barrier property as a function of the membrane compositions are discussed. Compared with the Nafion 117 membrane, the PVDF-Nafion blend membranes with 25 wt% of Nafion showed a decrease in the conductivity by about 2 orders of magnitude, and the methanol barrier properties increased about 3 orders of magnitude. If the ratio (σ/P) is adopted to characterize the performance of the membrane, the PVDF-PSSA and PVDF-Nafiion blend membranes …

Magnetic And Mössbauer Studies On Oxygen Deficient Perovskite, La₀.₆Sr₀.₄Feo3-Δ, Jinbo Yang, William B. Yelon, William Joseph James, X.-D. Zhou, Yixiang Xie, Harlan U. Anderson, Zili Chu

Physics Faculty Research & Creative Works

Samples of La_0.6Sr_0.4Fe_3-δ with varying oxygen vacancy contents were prepared by heating them in different gas flows. Magnetization measurement showed that samples with low oxygen vacancies have a magnetic ordering temperature in the range of 300-325 K while those with 9%-12% oxygen vacancies have a magnetic ordering temperature of 800 K and higher. Mössbauer spectra at 300 K exhibit paramagnetic or weak magnetic characteristics for the N₂, O₂, and air-quenched samples, whereas an average hyperfine field of 52 T is found for the CO/CO₂ reduced samples. The heat treatment in …

Structure And Magnetic Properties Of The Mnbi Low Temperature Phase, Jinbo Yang, William B. Yelon, William Joseph James, Qingsheng Cai, Samit Roy, Naushad Ali

Physics Faculty Research & Creative Works

High purity MnBi low temperature phase has been prepared and analyzed using magnetic measurements and neutron diffraction. The low-temperature phase of the MnBi alloy has a coercivity μ_0iH_c of 2.0 T at 400 K, and exhibits a positive temperature coefficient from 0 to at least 400 K. The neutron data refinement indicated that the Mn atom changes its spin direction from c axis above room temperature to nearly perpendicular to the c axis at 50 K. A canted magnetic structure has been observed below 200 K. The anisotropy field increases with increasing temperature which gives rise to …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 2/16/02- 5/15/02, 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 …

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle: Quarterly Report, William Culbreth, Pang Tao

Separations Campaign (TRP)

During the first two quarters of the work, the tasks included training students in the use of Monte Carlo codes used in radiation transport studies and the assessment of neutron multiplication factors for specific problems outlined by ANL-East through Drs. Laidler and Vandegrift.

The proposal also included objectives for the first year of work on this project, as listed below. The work conducted in the second quarter of the project was in partial completion of these objectives.

• Train UNLV students in the use of SCALE and/or MCNP for the assessment of nuclear criticality.

• Assess neutron multiplication factor, k …

Scitech News Volume 70, No. 3 (2016)

Sci-Tech News

Table of Contents:

Columns and Reports

From the Editor 3

Division News

Science-Technology Division 4

Chemistry Division 6

Conference Reflections (SPARKS Award Recipient) 12

Engineering Division 14

Engineering Division Awards Report 23

Aerospace Section of the Engineering Division 25

Reviews

Sci-Tech Book News Reviews 26

Adverstisements

IEEE 24

WeBuyBooks.net 28

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report Fourth Quarter (December 2001 To February 2002), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) Director to the U.S. Department of Energy (DOE) as described in the UNLV AAA proposal and Statement of Work for the Fourth Quarter.

The UNLV AAA UPP Director implements the program’s administration using staff from the Harry Reid Center for Environmental Studies (HRC) to ensure that work conducted under the UNLV AAA UPP meets program objectives. The UNLV AAA program consists of three components: Program Support, Research Infrastructure Augmentation, and Student Research.

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (December 1, 2001 – February 28, 2002) Report, 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 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 HT- 9, EP 823 and 422. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these alloys will be evaluated in environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. The extent and morphology of cracking of these alloys will further be evaluated …

Effect Of Ph And Gas-Phase Ozone Concentration On The Decolorization Of Common Textile Dyes, Craig D. Adams, Steven Gorg

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the results of a laboratory study on the effect of pH (2, 5, and 9) and gas-phase ozone concentration (1, 7, and 11 wt. %) on the decolorization efficiency via ozonation for seven common textile dyes. Higher gas-phase ozone concentrations resulted in higher decolorization rates due to more rapid ozone transfer. Higher gas-phase ozone concentration, however, was also observed to have a positive, neutral, or negative effect on ozone dose requirements for different dyes. In general, greater ozone utilization efficiency was achieved at lower pH levels where direct ozone reactions predominate. It was observed that because ozonation …

Removal Of Antibiotics From Surface And Distilled Water In Conventional Water Treatment Processes, Craig D. Adams, Yang Wang, K. Loftin, M. Meyer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Conventional drinking water treatment processes were evaluated under typical water treatment plant conditions to determine their effectiveness in the removal of seven common antibiotics: carbadox, sulfachlorpyridazine, sulfadimethoxine, sulfamerazine, sulfamethazine, sulfathiazole, and trimethoprim. Experiments were conducted using synthetic solutions prepared by spiking both distilled/ deionized water and Missouri River water with the studied compounds. Sorption on Calgon WPH powdered activated carbon, reverse osmosis, and oxidation with chlorine and ozone under typical plant conditions were all shown to be effective in removing the studied antibiotics. Conversely, coagulation/flocculation/sedimentation with alum and iron salts, excess lime/soda ash softening, ultraviolet irradiation at disinfection dosages, and …

Third Quarter Report, Covering January Through March 2002, John Farley

Transmutation Sciences Materials (TRP)

Progress from June 2001-November 2001 was presented at the winter meeting of the American Nuclear Society in Reno (November 12-15, 2001), and incorporated into a refereed conference proceeding. A copy of the refereed conference proceeding has been provided to Tony Hechanova. In brief, the paper described the new program to examine the corrosive effects of lead-bismuth eutectic (LBE) on steels. We employed various types of surface studies (Scanning Electron Microscope [SEM], and X-ray Photoelectron Spectrometry [XPS]) to examine steel samples that had been exposed to LBE for various lengths of time at various temperatures. The goal is to understand the …

Photocurrent Enhancement By Ticl4 Post-Treatment For Tio2 Nanoporous Film Electrode, Yan-Jie Ren, Li Zhang, Sheng-Min Cai

Journal of Electrochemistry

Enhanced photocurrent in dye-sensitized photoelectrochemical cell was obtained by post-treating the TiO₂ nanoporous film electrode with TiCl₄. By investigating the effect of the post-treatment on surface area, pore size distribution, laser pulse induced current transient of the film electrode, photocurrent increase by the post-treatment was assigned to the improved electron percolation resulting from broadening of interparticle neck.