Physical Sciences and Mathematics Commons^™

The Application Of Astm C1202-93 On Evaluating The Performance Of Anti-Corrosion Of Concrete, Yuan Chen Yuan

Journal of Electrochemistry

The test of chloride ion penetration based on the standards of ASTM C1202-93 is applied to evaluate the anti-corrosion performance of concrete in this research. Concrete specimens were produced according to ACI 318-89 mixture proportioning design and the Desenfied Mixture Design Algorithm (DMDA) and were measured the 6-hour coulombs at the age of 91 days. Results show that w/b is not the factor influencing chloride penetration of ACI concrete, as the ion penetration of ACI specimens is all higher than 2 000 Coulombs and can even be poorer than 10 000 Coulombs. With a proper amount of pozzolanic material, the …

The Research Of Nano-Sized Nio Anode Materials For Lithium Ion Batteries, Jun-Mei Yan, Jing Zhang, Yong Yang

Journal of Electrochemistry

The nano-sized NiO materials were synthesized by solid phase method and sol-gel method. The synthesis conditions were optimized by DSC and TG techniques. The sol-gel method was optimized by changing the solvent and regulating the solution's pH for preparing NiO material. The structure and morphology of the materials were also characterized by means of XRD and TEM techniques, and the electrochemical performances of the materials were studied by the galvanostatically charge and discharge experiments.

Cyclic Voltammetry And Surface Enhanced Raman Spectroscopy Of Dissociative Adsorption Of Ethanol On Pt-Ru Electrodes, Zhang Bin

Journal of Electrochemistry

The behaviors of dissociative adsorption of ethanol on roughened platinum-ruthenium electrode with high activity of SERS were studied by using cyclic voltammetry and in-situ surface enhanced Raman spectroscopy, surface enhanced Raman spectra of dissociative adsorption of ethanol on Pt electrode in acid was obtained for the first time. It is shown that the Pt-Ru could lower the over-potential of CO oxidation when compared to Pt electrode. The results show that the ethanol in acid medium can be self-dissociated at Pt-Ru electrode to produce CO, which discourage the further oxidation of ethanol, some information of Pt-C and Pt-C-Pt stretching vibration from …

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 …

An Electrochemical Behavior Of Limn_(2)O_(4) Electrode In Electrolyte Based On Room Temperature Ionic Liquid, Zheng Hong-He

Journal of Electrochemistry

The electrochemical behavior of spinel LiMn_(2)O_(4)electrode in ionic liquid electrolyte was investigated by using cyclic voltammetry, galvanostatic charge-discharge and ACimpedance techniques. The results reveal that the spinel LiMn_(2)O_(4)can be effectively cycled in electrolyte based on the ionic liquid with discharge capacity of 108.2mAh/g and Coulombic efficiency of more than 90% in the first cycle at room temperature. Temperature and current density play an important role in the electrode performances. The activation energy for lithium ion transfer through interface between the electrode and the electrolyte was evaluated by AC impedance spectroscopy. The high activation energy accounts for the poor cell performance …

Corrosion Behavior Of Sml,Erw Pipeline Steels Exposed To Seamud, Wei Hua

Journal of Electrochemistry

The corrosion behavior of API Spec X60 pipeline steels, including electric resistance welding(ERW) and Seamless (SML) types,in sea mud gathered fromYangtse River estuaryof the East China Sea was investigatedthrough linear polarization resistance, potentio-dynamic polarizationand electrochemical impedance measurements.The result indicate the improved corrosion resistance of SML in sea mud. The oxygen diffusion in the cathode zone determines the corrosion behavior of pipeline steel in sea mud.

Effect Of Sintering Temperatures On Synthesis Of Mgco_(0.4)Mn_(1.6)O_(4 ) Positive Materials In Magnesium Ion Battery, Xiu-Ling Gao, Li-Fang Jiao, Hua-Tang Yuan

Journal of Electrochemistry

The cathode material MgCo_(0.4)Mn_(1.6)O_(4 ) for magnesium ion battery was synthesized by sol-gel method. The TG-DTA and XRD analyses showed that the prepared samples has simple spinel structure. Effect of annealing temperature on electrochemical properties was researched.The result shows that the sample sintered at 700℃ has the best electrochemical properties.

Genetic Programming For Multitimescale Modeling, Kumara Sastry, Duane D. Johnson, David E. Goldberg, Pascal Bellon

Duane D. Johnson

A bottleneck for multitimescale thermally activated dynamics is the computation of the potential energy surface. We explore the use of genetic programming (GP) to symbolically regress a mapping of the saddle-point barriers from only a few calculated points via molecular dynamics, thereby avoiding explicit calculation of all barriers. The GP-regressed barrier function enables use of kinetic Monte Carlo to simulate real-time kinetics (seconds to hours) based upon realistic atomic interactions. To illustrate the concept, we apply a GP regression to vacancy-assisted migration on a surface of a concentrated binary alloy (from both quantum and empirical potentials) and predict the diffusion …

47th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 47th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 31 - August 4, 2005.

High Temperature Heat Exchanger Project: Quarterly Progress Report April 1, 2005 Through June 30, 2005, Anthony Hechanova

Publications (NSTD)

Quarterly Collaboration Meeting. General Atomics hosted a UNLVRF HTHX Project quarterly meeting on June 5 in San Diego, California. The purpose of the meeting was to promote collaboration and communication among the UNLV Research Foundation partners. Collaborators had the opportunity to discuss their research program plan and update their progress. The next meeting will be in September in Berkeley hosted by UC Berkeley.

HTHX Computational Design (UNLV). Work on optimizing the ceramic offset strip in compact HTHX design through parametric studies was performed and completed. A simple single channel model was used to perform parametric studies on dimensions and flow …

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements: Quarterly Progress Report (March – May 2005), Ajit K. Roy

Transmutation Sciences Materials (TRP)

Accomplishments:

● Analyses of defects (dislocations) in martensitic Alloy EP-823, cold-reduced to different levels, have been performed by using transmission electron microscopy. The dislocation density has been related to the degree of cold-reduction and residual stress in terms of a line-shape parameter determined by the positron annihilation spectroscopy (PAS).

● Additional PAS measurements are ongoing on tensile, welded and cold-worked specimens of Alloys EP-823 and HT-9 at the Idaho Accelerator Center of ISU. Both Subhra and Silpa are involved in these measurements.

● Silpa is performing neutron diffraction (ND) measurements at the Atomic Energy of Canada Limited (AECL), Chalk River …

Effect Of Silicon Content On The Corrosion Resistance And Radiation-Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems: Quarterly Progress Report (February – April 2005), Ajit K. Roy

Transmutation Sciences Materials (TRP)

This proposal is intended to study the effect of Si content not only on the corrosion resistance but also on the radiation-induced embrittlement of martensitic stainless steels. The susceptibility of these alloys with different Si content to stress corrosion cracking, general corrosion and localized corrosion will be evaluated in the molten LBE and aqueous environments of different pH values using state-of-the-art testing techniques. Testing in the aqueous media is intended to develop baseline data for comparison purpose. Radiation-induced embrittlement of these alloys will initially be studied by irradiating the test specimens with bremmstrahlung gamma radiation from 20-40 MeV electron beams …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, April 2005 To June 2005, Earl Wolfram, Thomas Hartmann, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert matrix 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 will be 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 will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to …

Study On Synthesis Of M-Phenoxy Benzoic Acid By Electrolysis Oxidation Method, Wei Xu, Chong-Tao Zhao

Journal of Electrochemistry

The m-phenoxy benzoic acid was synthesized by oxidation m-phenoxy toluene using Cr(Ⅵ)as oxidation media, which was prepared by electrolysis oxidation of Cr(Ⅲ)in the electrochemical bath using Nafion 417 as a diaphragm, Pb-PbO_(2) as an anode and Pb as cathode. The effect factors on the electrochemical oxidation of Cr(Ⅲ)to Cr(Ⅵ)in this electrolysis were studied. Furthermore, the optimal conditions for electronic synthesis of m-phenoxy benzoic acid were also discussed.

Electrochemical Stability Of Pva Alkaline Gel Polymer Electrolyte Membranes, Jun-Hong Wang, Jian-Min Liu, Hua-Bin Yang, Zuo-Xiang Zhou

Journal of Electrochemistry

Polyvinyl alcohol (PVA) alkaline polymer gel electrolyte(GPE) membranes were successfully prepared by a solution-casting technique and their electrochemical stabilities were investigated. The electrochemical impedance spectrum (EIS) results showed that the ionic conductivity of the PVA alkaline GPE membranes first increased with the increase of KOH content, then decreased with the further increase of KOH. When the weight percentage of the KOH in the PVA alkaline GPE membrane approached to 42%, it exhibitedthe highest ionic conductivity of 2.01×10~(-3 ) S/cm at room temperature (R.T.). The X-ray diffraction (XRD) results revealed that with the increase of KOH the crystalline of the PVA …

Using Electrodeposition To Fabricate Mould For Polymer Microfluidic Chip, Luo Yi

Journal of Electrochemistry

Many researches have been focused on polymer microfluidic chip in recent years and the mould plays an important role in its fabrication process. Using electrodepositingmethod to fabricate a metal mould for polymer microfluidic chip has been presented in this paper. An ultra-thick photoresist SU-8 was coated on a pretreated metal plate, after photolithography, nickel was electrodeposited in the patterned SU-8, then was removed the SU-8 to obtain a final metal mould. This methodreduces workload of electrodeposit largely. Applying counter current before deposit, adding additive to solution and vacuum anneal after demould have been used to improve the binding force between …

A Preliminary Study Of Electrocrystallization Of Bismuth On Glassy Carbon, Min-Li Yang, Zhan-Jun Zhang

Journal of Electrochemistry

The electrocrystallization of bismuth on glassy carbon electrodes (GCEs) from nitrate solutions was studied by cyclic voltammetry and chronoamperometry. Cyclic voltammograms exhibit a crossover between the cathodic and anodic branches, characteristic of the formation of bismuth nuclei on GCEs, and show that the bismuth electrocrystallization on GCEs is a diffusion-controlled reaction. The current transients were analyzed with the Scharifker and the Heerman equations. With the increaseof Bi~(3+)concentration, the non-dimensional plots leaned to the theoretical curve for 3D instantaneous nucleation and growth. The overpotential dependence of nucleation and growth mechanism was also found. With the increase of overpotential, the non-dimensional curve …

A Comparison On Structural Sensitive Adsorption Of Sb On Au Single Crystalline Electrodes, Jia-Wei Yang, Wang-Huo Shang, Qiong Wu, Bing-Wei Mao

Journal of Electrochemistry

We compare the behaviors of irreversible adsorption of Sb(III) and its reduction, underpotential deposition of Sbon Au(111) and Au(100) as well as mutual interactions of the processes. Based on in-situ scanning tunneling microscopic and cyclic voltammetric results, the substrate structure not only influence anion adsorptionbehavior and thus the Sb adsorption structure, but also the stability of its own structure. On Au(111) surface,the irreversibly adsorbed dense and disordered SbO~(+ )film structure remains after reduction of the film; while on Au(100)surface, due to the coadsorption of SO_4~(2-),an ordered(2×2)structure is formed after reduction.UPD of Sb on Au(111)is accompanied by significant surface alloying, which …

Investigation On Ru-Ti-Ir-Sn Oxide Anode Coatings For Electrolyzing Seawater, Wang Ke

Journal of Electrochemistry

The anode coatings of Ru-Ti-Ir-Sn oxide with various compositions were prepared by thermal decomposition. The physical and electrochemical properties of the coatings were characterized by scanning electron microscope (SEM), energy dispersive X-ray detector (EDX), accelerated life, current efficiency, anti-Mn~(2+)contamination, polarization curveandcyclic voltammetry tests. The results showed thatthe anode coating with optimized formula possessed excellent overall properties for electrolyzing seawater.

Ni-Mo-P Alloy By Electroless Deposition And Its Properties, Sen-Lin Wang

Journal of Electrochemistry

The electroless Ni-Mo-P alloy has been deposited from the alkaline bath containing boric acid as a buffer agent and sodium citrate as a complexing agent. The effect of deposition parameters, such as pH and concentration of (NH_(4))_(6)Mo_(7)O_(24)4H_(2)Oon the plating rate, the composition, the structure and the microhardness of the coating was examined. It was found that the presence of molybdenum has an inhibitory effect on the alloys deposition. As a consequence, the percentage of molybdenumin the Ni-Mo-P coatings never reaches high values, which was lower than 20 at%. It was also shown that the deposition condition affects the microhardness of …

Structure And Corrosion Electrochemical Properties Of Self-Assembled (3-Mercaptopropyl) Trimethoxysilane Films On Copper Electrode, Huangling Huangling, Ke-Fa Lin, Fang-Zu Yang, Shu-Kai Xu, Shao-Min Zhou

Journal of Electrochemistry

A self-assembled monolayer of (3-mercaptopropyl) trimethoxysilane(MPTS) was formed on a electrochemical polished copper surface electrode. The corrosion protection abilities of the monolayer were evaluated in 5% NaCl solution using electrochemical linear polarization. The effects of deposition time and silane concentration on corrosion of copper were also discussed. The surface structure of MPTS films was measured by FT-IR and SEM. It was found that the corrosion resistance of copper was reduced markedly owing to the MPTS monolayers formation on copper. The MPTS monolayer retarded the reduction of dissolved oxygen and inhibited the growth of copper oxide in the NaCl solution. FT-IR …

Selective Electroless Copper Plating Micro-Pattern On Ceramics Without Sensitisation And Activation, Zhen-Lin Xu

Journal of Electrochemistry

The purpose of this article is to provide a new technology of electroless copper plating without palladium activation steps. By combining the technology of laser micro-etching with the new copper-plating bath, copper plating on ceramics was obtained. The experimental results showed that the solution used for copper electroless plating was stable and the copper coating obtained was bright,dense with good electrical conductivity.The line definition was about 40 μm. The electroless Cu films deposited from this system were gentle and required simple operating conditions.

Potential Fluctuations Of 7075 Aluminum Alloy Under Thin Electrolyte Layers, Su-Jing Chen

Journal of Electrochemistry

Lens tissues adsorbing 3.5% sodium chloride solution were used to simulate thin electrolyte layers. The 7075 aluminum alloy was immersed under the thin electrolyte layers for 0, 4, 6, 8 and 12 h respectively. Then the fluctuations of natural-corrosion potentials of the alloy were monitored. The fluctuations of natural-corrosion potential were observed rather small in the initial corrosion stages after 6h immersion, and the positive peaks of potential appeared. However the amplitudes reached 20mV after 4h and 12h immersion. The RMS of natural-corrosion potentials decreased with corrosion time at first and then increased. It reached a minimum at 4 h. …

The Effect Of Oxidant On Structure And Properties Of Pan/Ptfe Conducting Composite Membrane, Chang-Yuan Tao

Journal of Electrochemistry

The PAn/PTFE conducting composite membrane was prepared by means of in-situ permeating chemical polymerization, with (NH_(4))_(2)S_(2)O_(8) and Na_(3)VO_(4) being used as an oxidant respectively.The polymerization-growth behavior of the aniline by using different oxidant was compared. In addition, the oxidant effect on the structure and properties of conducting composite membrane was discussed. The results of SEM micrographs, pore size distribution and electrochemical methods suggested that using either oxidants could also induce the product with small pore size and dense pore structure. Compared with (NH_(4))_(2)S_(2)O_(8), using Na_(3)VO_(4 ) as an oxidant would induce the polyaniline with denser polymers in the membrane pores, …

The Preparation And Performance Of The Aqueous Matrix For Molten Carbonate Fuel Cells, Hua-Xin Lin

Journal of Electrochemistry

PVA matrix of MCFC was prepared from the α-LiAlO_(2 )powder, and polyvinylalcohol(PVA), Compared with the conventional PVB matrix, higher porosity,higher thermal weight loss and smaller maximum pore diameter were achieved for PVA matrix. Single cell was assembled with PVA matrix. At reaction gas pressure of 0.9MPa, under reaction gas utilization of 20%, at 300 and 428.57mA·cm~(-2), the cell voltage was 0.849 and (0.739) V respectively, and the output power density was 254.7 and 316.7mW·cm~(-2 )respectively, which are higher than those of the cell assembled with PVB matrix. During thermal cycles, the cell performance shows a slightly decreasing-rising-stabilizing process, which might …

The Synthesis, Characteristics And Performance Of Cnt Composites As Anodic Materials In Litium-Ion Battery, Quan-Feng Dong, Ming-Sen Zheng, Zhen-Cai Huang, Ming-Gang Jin, Ya-Ding Zhan, Zu-Geng Lin

Journal of Electrochemistry

As an anodic material for lithium ion battery the carbon nano-tube (CNT) and some compounds based on tin have ever been investigated intensively. The fruited progress has not been made yet, however. In this paper the composites of CNT and Sn/SnO_(2)were synthesized employing two methods and characterized by SEM and XRD. And the electrochemical performance of the composites was investigated.

Preparation And Characterization Of Mcm-41/ Pvdf-Hfp Composite Microporous Polymer Electrolytes For Li-Ion Batteries, Zuo-Feng Chen

Journal of Electrochemistry

MCM-41/vinylidine fluoride-hexafluropropene copolymer (PVdF-HFP) composite microporous polymer electrolytes were prepared with mixed solvent of N, N-Dimethylformamide (DMF) and acetone. The influence of MCM-41 and nano-SiO_(2) on the porous structure of the microporous polymer electrolytes were studied with SEM. The results show that MCM-41 could take the place of the plasticizer in the process of making pores, and bring the preparation of microporous membranes easily. The preliminary electrochemical tests showed that the ion conductivity of composite microporous polymer electrolyte with 10% MCM-41 was about 10~(-3) S cm~(-1), and the performance of batteries was improved. The mesoporous MCM-41selected in the paper possesses …

Application Of Nickel Foam Electrode For Electroreduction Intermediate Of Purine, Hui-Wen Yang, Xi-En Hu, Xue-Jun Wang

Journal of Electrochemistry

Nickel foam with weight uniformity, good porosity ,pore size and low resistivity as a three-dimensional cathode was used in a filter-press electrochemical reactor. The H_(2)SO_(4) as supporting electrolyte, separator of cation ion exchange membrane, and the lead plate as an anode were used. The cyclic system consisted of electroreduction reactor, pump, store tank and ampere meter. NAU was electroreduced in the cathode chamber of the reactor. Purine intermediate was synthesized with DAU, and the results were compared with those of iron powder reduction process. A peak current in the electroreduction process was detected. The current density of nickel foam increased …

Preparation, Characterization And Electrochemical Properties Of Nano Tio_(2)-Cnt-Pt On Ti Substrate Complex Electrode, Dao-Bao Chu

Journal of Electrochemistry

The nanoTiO_(2)-CNT-Pt on Ti substrate complex electrodes were prepared from precursor of (Ti(OEt)_(4)) directly hydrolyzed and by cyclic voltammograms electroplating method . The XRD and SEM results showed that the nano TiO_(2) (anatase) particle sizes ranged 5~10 nm and the Pt nanoparticle (average size 9nm) dispersed uniformly on nanoTiO_(2)-CNT film surface. The electrocatalytic activity of Ti/nanoTiO_(2)-CNT-Pt electrode was investigated by cyclic voltammetry and chronopotentiogram. The results indicated that the Ti/nanoTiO_(2)-CNT-Pt electrode exhibited very high electrocatalytic activity and stability for the electro-oxidation of methanol at room temperature. When Pt loading was 0.32 mg/cm~(2), the oxidation peak current of methanol was 480 …

Initial Process Of Pyrophosphate Copper Electroplating, Shao-Bin Feng, Shi-Bo Shang, Li-Ting Feng

Journal of Electrochemistry

The relationship between the type of on changes of copper electroplating potential~time and the adhesion of coating layer was examined by chronopotentiometry. The conception of critical initial current density (D_(KC)) was put forward. When the initial working current (D_(KI)) was higher than the critical initial current, the iron electrodewas polarized to activation potential of iron surface firstly, then to the activation of the substratesurface, and finally to depositionpotentialof copper ion. The coating deposited on the active surface and had goodadhesion.On the contrary,when D_(KI) was lower than D_(KC), the coating deposits on the surface of "passivated" iron substrate, and bad coating …