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Raman Spectroscopic Study On Mechanism Of Aluminum Triphosphate Pigment, Zhi-Jun Gu, Yong-Gui Liao, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su

Journal of Electrochemistry

The painted steel sample whose coating contained anticorrosive pigment has been investigated by Raman spectroscopy. The protective mechanism of aluminum triphosphate pigment for A3 steel is proposed as follows: Aluminum triphosphate can be dissolved and arrive at the surface of the steel.The dissolved triphosphate ions can complex with ferric ions.And the new products, namely ferric triphosphate, can strongly adhere at the surface of the steel by chemical bonds slowly. At last, a compact protective film, which effectively separates the steel substrate from the aggressive media, is formed at the steel surface.

Study On The Orthogonal Test Of Al-Substituted α-Ni(Oh)2 Prepared By Complexation-Precipitation Method, Hui Chen, Jian-Ming Wang, Tao Pan, Hui-Ming Xiao, Jian-Qing Zhang

Journal of Electrochemistry

Al-substituted α-Ni(OH)₂ was prepared by a complexation-precipitation method and characterized by XRD.The electrochemical performance was tested by the charge-discharge method. The experimental results of orthogonal test showed that the effect order of some key preparative conditions on the electrochemical performance of Al-substituted α-Ni(OH)₂ was the concentration of aqueous ammonia, the content of aluminum and pH value.The optimum prepareative conditions for obtaining the sample with maximum specific discharge capacity (304 mAh·g^-1) were 0.5 mol·L^-1 aqueous ammonia, 15 mol% Al content and pH 11.0.

Uncertainty In Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode Based On The Transition Region Of Diffusion-Controlled Impedance, Xian-Xia Yuan, Nai-Xin Xu

Journal of Electrochemistry

Hydrogen diffusion coefficient in MlNi_3.75Co_0.65 Mn_0.4Al_0.2 metal hydride electrode has been determined with transition region of diffusion-controlled impedance. Multiple solutions were obtained at each data point because of the periodic characteristic of some functions used in the calculation, and the maximum difference between the solutions reached several orders of magnitude. On the other hand, the solutions varied for different data points in the transition region of diffusion-controlled impedance of the same experimental plot. It could be concluded that this method is not so well defined and some modification is required.

The Determination Of The Best Modified Way And Microscopical Analysis For Enzyme/Immunoelectrodes, Sa-Ying Dong, Hong-Ren Wang, Yu-Zhu Gao, Guang-Zhang Chen, Ming-Xiang Lv, Bo-Yi Tian

Journal of Electrochemistry

In this paper, the electrochemical response characteristics of enzyme and immuno electrodes were studied by cyclic voltammetry under different conditions. Our goals were to determine the best modified way of bioelectrode, which was the base of biosensor's application. 30U GOD and 0.8 mg/mL SEC1 antibody were suitable to bioelectrode preparation and detection. The microscopical analysis was finished with scan microscopy.

Preliminary Study On Direct Ethanol Fuel Cell, Shu-Qin Song, Li-Kang Chen, Jian-Guo Liu, Zhao-Bin Wei, Qin Xin

Journal of Electrochemistry

The performance of a direct ethanol fuel cell based on Nafion115 was reported.PtRu/C and Pt/C were used as ethanol anode and oxygen cathode catalysts in a single cell of size 9 cm² .The effects of temperature, oxygen pressure, the flow rate of ethanol, and oxygen, and ethanol concentration were tentatively studied. The experimental results showed that the cell open circuit voltage 0.608 V, the cell voltage 0.329 V at 50 mA/cm², and the peak power density 19.25 mW/cm² were reached under the conditions of T_cell =85 ℃, P_O2 =0.5 MPa, C_ethanol =1.0 mol/L …

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.

An Investigation Of Inhibition Mechanism Of Cerium For Aluminum Alloy 2024-T3, Min-Hua Shao, Yan Fu, Rong-Gang Hu, Chang-Jian Lin

Journal of Electrochemistry

Cerium compounds are promising inhibitors for aluminum alloy. However, the inhibition mechanism is not very clear. Scanning microreference electrode (SMRE) technique was used to probe the potential imaging of Al 2024 T3 in NaCl and CeCl₃ solution. The results of SMRE showed that in NaCl solution a severe localized corrosion occurred on the surface of Al 2024 specimen at once and maintained for a long time. The corrosion activity of Al alloy in CeCl₃ decreased with immersion time and disappeared finally. Additionally, the competition of inhibition and aggression between Ce³⁺ and Cl^- on Al alloy was …

Electrosynthesis Of Glyoxylic Acid In A Packed Bed Reactor, Jin-Hong Fan, Jun Li, Yu-Zhong Su, Hao-Qi Gao

Journal of Electrochemistry

Glyoxylic acid was produced by electroreduction of oxalic acid in a packed bed reator. The cathodic and anodic electrolytes were super-saturated oxalic and hydrochloric acid aqueous solutions separated by a super-acid ion-exchange membrane. The current efficiency and yield of glyoxylic acid were studied under different structured packed bed reactors and different electrode materials, temperatures and current densities. The results indicated that the current efficiency of synthsis of glyoxylic acid was over 66.2% and the concentration of glyoxylic acid could reach 2.02% after 45min electrolysis with cathode of lead particles and anode of graphite board under conditions of temperature 32 ℃, …

Determination Of Copper In The Waste Water Of Plating By Chronocoulometry For Flowing Solution, Xin-Hua Lin, Wei Chen

Journal of Electrochemistry

The chronocoulometry for flowing solution was devoloped and applied to the detemination of copper(Ⅱ) in the waste water of plating. The linear range of copper(Ⅱ) was 2～16mg/L, and the relative standard deviation was less than 0.1% (n =8). The recovery was 98%～103% for copper(Ⅱ) in the waste water.Chronocoulometry for flowing solution overcomed noise disturbance resulting from capacity current and variety of property of electrode surface. This method was sensitive,accurate and well reproducible.

Further Evidence For Surface Properties Of Porous Silicon Resulting In Electroluminescence, Zhan-Jun Zhang, Bin Wu, Jing-Jian Li, Zhong-Fan Liu, Sheng-Min Cai

Journal of Electrochemistry

The electroluminescence of porous silicon in solutions at positive biases was investigated by luminescence spectrometer. The electroluminescence of porous silicon in solutions mainly depended on its surface properties. The elelctroluminescence was much enhanced when the sample of porous silicon was electrolyzed once again which had undergone an electroluminescence test. The tests of both cyclic voltammetry and the luminescence of the sample of porous silicon prepared by repeated electrolysis provided further evidence that the electroluminescence of porous silicon in solutions at positive biases stemmed from the oxidation of Si-H on the surface of porous silicon. The voltage tunable emitting for porous …

Photoelectrochemistry Of La3+ Doped Semiconductor Porous Films Sensitized By Ru(Bpy)2(Ncs)2 Dye, Li Zhang, Yan-Jie Ren, Sheng-Min Cai

Journal of Electrochemistry

The La³⁺-doped TiO₂ nanoparticles were prepared with hydrothermal method.The photoelectrochemical properties of La³⁺-doped TiO₂ nanoporous-film electrode sensitized by Ru(bpy)₂(NCS)₂ were studied. The conversion efficiency of light to electricity and the energy conversion efficiencies were ineased with the depth of La³⁺-doped TiO₂ nanoporous-film electrode.

Varying Current Electro-Synthesis Of Glyoxalic Acid In Pairs In The Fixed-Bed Electrolytic Cell, Yin-Sheng Chen, Xin-Sheng Zhang, Ying-Chun Dai, Wei-Kang Yuan

Journal of Electrochemistry

As for the process of the electro oxidation of glyoxal to glyoxalic acid, the electrolytic result of either fixed bed electrolytic cell or varying current electrolysis was better than that of either flat plate electrolytic cell or constant current electrolysis. The average current density of varying current electro synthesis of glyoxalic acid in pairs was 1535 A/m² and the current efficiency were 85.3% and 86.7% and the selectivity were 93.9% and 94.0% for the anodic oxidation and cathodal reduction respectively. The initial composition of anodic electrolyte was 7% glyoxal and 8% hydrochloric acid (W/W) and the cathodal electrolyte consisted …

Electrochemical Synthesis And Characterization Of The Nickel Electropolyurushiol Coordination Polymer, Feng Gao, Guo-Cai Shen, Jie-Yuan Tang, Wen-Gong Zhang

Journal of Electrochemistry

The nickel electropolyurushiol coordination polymer (EPU Ni²⁺) was obtained by the reaction between nickel chloride isopropyl alcohol solution with electropolyurushiol (EPU). The electrochemical polymerization of urushiol and the preparation of nickel electropolyurushiol coordination polymer were investigated. The coordination polymer was characterized by XPS, FT-IR, DMTA and AES methods, and its composition and structure were determined.The content of Ni²⁺ reached up to 7.5%. It was shown that there was certain coordination between Ni²⁺ and electropolyurushiol in the coordination polymer, thus cross-inks were formed. Therefore the glass transition temperature of the coordination polymer increased and heat resistance was …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report 11/16/01- 2/15/02, 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. The transport of oxygen and corrosion products, their interaction and variation of corrosion/precipitation along the flow are not well understood.

The first subtask of this project involves using a …

Development Of A Systems Engineering Model Of The Chemical Separations Process: Quarterly Progress Report 11/16/01- 2/15/02, Yitung Chen, Randy Clarksean, Darrell Pepper

Separations Campaign (TRP)

The AAA program is developing technology for the transmutation of nuclear waste to address many of the long-term disposal issues. An integral part of this program is the proposed chemical separations scheme.

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 …

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the effect of hydrogen on 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 test materials will undergo appropriate thermal treatments prior to being hydrogen-charged by potentiostatic cathodic polarization technique in a simulated aqueous environment at different temperatures of interest. The specimens, upon completion of testing, will be metallographically examined. Further, the scanning electron microscopy (SEM) will be used to determine the extent and nature of cracking in the specimens tested. The thrust of the proposed …

The Influence Of Gold Substrate Topography On The Voltammetry Of Cytochrome C Adsorbed On Carboxylic Acid Terminated Self-Assembled Monolayers, Michael C. Leopold, Edmond F. Bowden

Chemistry Faculty Publications

Interfacial investigations of a protein monolayer electrochemical system, equine cytochrome c (cyt c) adsorbed to carboxylic acid terminated self-assembled monolayer (COOH SAM) modified gold electrodes, were performed. Electrochemical, spectroscopic, and scanning probe microscopy techniques were utilized to explore the influence of gold topography in the cyt c/COOH SAM/gold system. COOH SAMs were prepared from 14-mercaptotetradecanoic acid and 11-mercaptoundecanoic acid on a variety of substrates including evaporated, bulk, single crystal, and epitaxially grown gold on mica. These substrates encompassed a wide range of surface roughness. As the topography of the gold became smoother, SAMs exhibited an increased ability to …

Opacity Enhancement Of The On-Road Remote Sensor For Hc, Co And No, Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Studies Of Ppi Dendrimers: Structures, Properties, And Potential Applications, Dian He

Theses, Dissertations and Capstones

The research reported in this thesis focused on poly (propylene imine) (PPI) dendrimers, in terms of their structures, properties and potential applications. Different analytical techniques, including our main research tool, NMR spectroscopy, as well as AFM imaging and UV-vis spectroscopy, were used for the elucidation of structural information. The study showed (1) PPI dendrimers tend to have the extended chain conformation in polar solvents because of the strong interaction between solvent and dendrimer molecules, while in nonpolar solvents the dendrimers are inclined to have the back-folded chain conformation as a result of the weaker interaction between …

Calorimetric Study Of Block-Copolymers Of Poly(N-Butyl Acrylate) And Gradient Poly(N-Butyl Acrylate-Co-Methyl Methacrylate), A I. Buzin, M Pyda, P Costanzo, K Matyjaszewski, B Wunderlich

Chemistry and Biochemistry

The nanophase separation in diblock and triblock copolymers consisting of immiscible poly(n-butyl acrylate) (block A) and gradient copolymers of methyl methacrylate (MMA) and n-butyl acrylate (n BA) (block M/A) were investigated by means of their heat capacity, C_p, as a function of the composition of the blocks M/A and temperature. In all copolymers studied, both blocks are represented by their C_p and glass transition temperature, T_g, as well as the broadening of the transition-temperature range. The low-temperature transition of the blocks A is always close to that of the …

An On-Line Acid-Base Titration Applet In The Generic Tutorial System For The Sciences Project, Thomas Lee Gummo

Theses Digitization Project

The purpose of this Master's Project was to develop an Acid-Base Titration Simulator. It was also to be a part of the California State University - San Bernardino's GTSS, Generic Tutorial System for the Sciences, project. The main benefit is that students will be able to conduct titration experiments over the Internet without being in the laboratory and without costly equipment or dangerous chemicals. Instructors at the high school and college level can demonstrate the key principles of titration.

Stimulation And Modeling Of Pond Formations On The Asteroid 433 Eros, Justin Thompson

Inquiry: The University of Arkansas Undergraduate Research Journal

"Ponds" are surface features that appear to be the result of the deposition of finer material on the asteroid's regolith, the layer of loose sediment that blankets the entire asteroid. Ponds were discovered by the NEAR Shoemaker spacecraft in January, 2001, on the asteroid 433 Eros. The objective of experimentation is to simulate the development of these ponds in the Andromeda planetary sciences environmental chamber. The Andromeda Chamber offers a unique ability to simulate surface environments that occur on Eros. The chamber was used to simulate the processes that occur as Eros emits gas through its outer surface, including the …

Electrostatic Microencapsulation Of Composite Particulate Materials For Manufacturing And Environmental Applications, S. De, M. Pritchett, Malay K. Mazumder, Robert A. Sims, C. U. Yurteri, Alexandru S. Biris, A. Rego

Journal of the Arkansas Academy of Science

Electrostatic microencapsulation is a dry coating process where two powders, one containing the fines and the other relatively larger particles, are separately dispersed in air and pre-charged with opposite polarity, using corona charging for electrostatic coagulation. These oppositely charged core and guest particles experience attractive electrostatic forces and generate composite particles. Preliminary experiments of electrostatic microencapsulation were performed using Anionic Exchange Resin (AG 1-X8) as the host particle and Red Toner (Omega 4000) as the guest particles. An electrostatic microencapsulation tower has been designed for generation of composite particles using particles of different particle size distribution.

Electrical Network-Based Time-Dependent Model Of Electrical Breakdown In Water, R. P. Joshi, J. Qian, K. H. Schoenbach

Bioelectrics Publications

A time-dependent, two-dimensional, percolative approach to model dielectric breakdown based on a network of parallel resistor–capacitor elements having random values, has been developed. The breakdown criteria rely on a threshold electric field and on energy dissipation exceeding the heat of vaporization. By carrying out this time-dependent analysis, the development and propagation of streamers and prebreakdown dynamical evolution have been obtained directly. These model simulations also provide the streamer shape, characteristics such as streamer velocity, the prebreakdown delay time, time-dependent current, and relationship between breakdown times, and applied electric fields for a given geometry. The results agree well with experimental data …

Formation Of Copper Dots In Copper Decoration Technique, Swee Yong Pung

Student Works (2000-2009)

Copper ions are dissolved from highly pure copper plate into the methanol during copper decoration process. As a result, copper concentration in methanol is increased with time. The copper concentration in methanol measured by ICP-OES is correlated well with the calculated value based on the magnitude of current and time during the process. Consequently, higher magnitude of current can be applied to build up copper concentration in methanol in shorter period. When copper ions are ejected in methanol, they are positively charged. They experience force from electric field and migrate towards oxide surface. Eventually, these copper ions will be discharged …

Analysis Of Plastics In The Tyre Industry Using Fourier Transform Infrared Techniques, Differential Scanning Calorimetry And Softening Point Apparatus, Ching Ching Loh

Student Works (2000-2009)

The plastics in a tyre factory were investigated. The plastics were analysed by FTlR-transmission, FTI.R-ATR, softening point apparatus as well as a Differential Scanning Calorimeter. All the plastics were detected to be polyethene based with melting point range of 107 to 125°C. It was also observed that The FTIR transmission spectrum can be different from the FTIR-ATR spectrum. The FTIR-ATR spectrum gives a higher band intensity at longer wavelengths compared to the FTIR-Transmission spectrum. Interference fringes can be present in the FTlR transmission spectrum. In addition to the above, it was also found that the melting point of plastics obtained …

Selective Separation Of Lead (Ii) And Cadmium (Ii) From Simulated Wastewater Solutions By Electrodeposition On Carbon Based Electrodes, Pek Yew Liew

Student Works (2000-2009)

The efficiency of electrodepositing Pb and Cd onto two carbon based electrodes glossy carbon electrode (GCE) and activated carbon paste electrode (CPE) and the selectivity of separating these metals from mixtures were investigated by cyclic voltammetry and square wave voltammetry. Good efficiency was observed in depositing Pb onto these electrodes but for Cd deposition. the efficiency was limited by the hydrogen evolution reaction at pH 3 and the dissociation of water al pH S. However, chis efficiency was improved when some amount of Pb was preplated onto the electrodes. When excess malonic acid was present in the system. the deposition …

University Of Nevada, Las Vegas Transmutation Research Program Annual Report 2001, Anthony Hechanova, Elizabeth Johnson, Gary Cerefice

Transmutation Research Program Reports (TRP)

The UNLV Transmutation Research Program was established in March 2001 as part of the national Advanced Accelerator Applications program to develop the technologies necessary for the ecological and economical treatment of spent nuclear fuel.

The primary role of the UNLV program in the national effort is the training of graduate and undergraduate students in nuclear engineering and other related fields to support the augmentation of the U.S. human infrastructure for transmutation technologies.

To accomplish this role, UNLV has developed the TRP with the primary focus of supporting student research into transmutation and supporting technologies. This focus is realized through the …

Experimental Investigation Of Steel Corrosion In Lead Bismuth Eutectic (Lbe): Characterization, Species Identification, And Chemical Reactions, John Farley, Dale L. Perry, Allen L. Johnson

Transmutation Sciences Materials (TRP)

The goal of the present research is to achieve a basic understanding of corrosion of steels by Lead Bismuth Eutectic (LBE). Liquid LBE is under consideration in the transmuter as both a spallation target and as a blanket coolant. There have been previous studies of LBE, especially by the Russians, who have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. However, a fundamental understanding and verification of its role in the corrosion of steels is still very incomplete. We have begun a program of post-experiment testing and analysis on steel samples that have been in intimate …

Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry, Allen L. Johnson

Transmutation Sciences Materials (TRP)

This research program will analyze various steel samples that have been exposed to LBE as part of the national program to develop LBE and transmutation technologies. This information will be paramount in developing engineering efforts to control, avoid, and/or minimize the effect of corrosion of steels by LBE in transmuter and LBE systems. Additionally, this program provides UNLV researchers with hands-on experience that will be crucial in developing the UNLV LBE program, supporting the University’s mission with the ISTC target complex, and the future development of additional facilities to examine LBE systems.

The research group plans to test the hypothesis …