Physical Sciences and Mathematics Commons^™

Studies Of The Electrode Preparation Of Electrode From Lead Carbonate For Lead Acid Battery Ⅰ The Activation Of The Pme, Zhongxu Dai, Dihua Wang, Junwei Jiang, Yunhong Zhou, Jinyun Zou

Journal of Electrochemistry

Lead carbonate which was an intermediate product in lead hydrometallurgy without pollution of lead vapor and sulfur dioxide was selected as electrode material of lead_acid batteries. In the present work,the performances of PbO 2/PbSO 4 or PbSO 4/Pb electrode transformed from PbCO 3 have been investigated by powder microelectrode technique combined with cyclic voltammetry.The results show that the CV characteristics of either negative or positive electrode prepared from PbCO 3 is as good as that of both electrodes made from lead oxide produced by mill machine,when a powder microelectrode with PbCO 3 transformed into PbSO 4 in 1.0 mol/L H …

Studies On Methods Of Fuel Cells Electrodes Preparation, Jun Gu, Sheng Sui, Guangqiang Li, Zhitong Sui

Journal of Electrochemistry

In fuel cells,the structure of electrodes is an important factor which effect the cell performance.To improve the structure and the performance of electrodes,a new method of providing fuel cell electrodes is proposed in this paper.PTFE(polytetrafluoroethylene) and ethyne black was ground for about half an hour in a high_speed grinder,then the catalyst was added into the grinder and milled for an hour.This milled catalyst was transferred into a mixer followed by the addition of surface_active agent. After a suspension was formed,it was filtered under vacuum condition.Then a thin uniform filter_cake of the catalyst was formed,which was rolled together with a current_collecting …

Photoelectrochemical Studies On The Tio_2 Nanostructured Porous Film Sensitized By Cyanine Dye, Li Zhang, Maizhi Yang, Xuebin Qiao, Yanzhong Hao, Enqing Gao, Shengmin Cai

Journal of Electrochemistry

The photoelectrochemical behaviors of the TiO 2 nanostructured porous film sensitized by cyanine dye were investigated in this paper.The results showed that the excitaed state level matched the conduction band edge of TiO 2 nanoparticle.Therefore the sensitization of the dye can increase the photocurrent intensity of the TiO 2 nanostructured electrode obviously and results in a red-shift of optical absorption from the ultra_violet region to the visible.As a result,the light_to _electricity conversion efficiency was improved evidently,the maximum value of IPCE has reached 12.1%.

Study On Electrochemical Reduction Properties Of Nitrobenzene, Chuna Ma, Wenkui Zhang, Hui Huang, Yongping Gan

Journal of Electrochemistry

The electrochemical reduction characteristics of nitrobenzene was extensively investigated by using the techniques such as quasi_steady_state polarization,cyclic voltammetry,fast linear potential sweep method and chronoamperometry in this paper.The electroanalytic properties of Cu,Cu_Hg and Cu_Ni electrodes were evaluated.Based on the study of the transient steping behaviour of nitrobenzene to PAP,the reduction mechanism was discussed.The results showed that the transition steps existed on the electrochemical reduction of nitrobenzene in acidic solution,the reactant is also absorbed on electrodes surface. The control step in the reduction of nitrobenzene was ascribed to the diffusion of nitrobenzene and its electrochemical reductive products in the acid solution.

The Electrochemical Behaviors Of Superoxide Dismutase At Promoter Modified Gold Electrode, Xiaqin Wu, Xiaoyun Meng, Zhesu Wang, Zongrang Zhang

Journal of Electrochemistry

The electron_transfer process of superoxide dismutase was investigated by cyclic voltammetry at the 4,4'_dithiodipyridine,L_cysteine,histidine and arginine modified gold wire electrodes repectively.The quasi_reversible behavior was observed at L_cysteine modified gold electrode.An irreversible electrochemical behavior has been observed at hisdinine modified gold wire electrode.

Crossover Photonic Switching Network With Cmos/Seed Smart Pixel Device And 2d Optical Fiber Bundle Array, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Deming Liu

Electro-Optics and Photonics Faculty Publications

A 16 X 16 Crossover photonic switching network with hybrid integrated CMOS/SEED smart pixel device and 2D optical fiber bundle array I/O access device is reported in this paper. SEEd array devices ar used as light receivers and transmitters, while CMOS devices make efficient logical processing. 4 X 40 2D multilayer optical fiber bundle arrays are fabricated and are used as I/O access devices in the crossover photonic switching network. The center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125micrometers , and the spacing between adjacent layers is 250micrometers . Displacing …

Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu

Electro-Optics and Photonics Faculty Publications

An optoelectronic switching network with 2-D optical fiber bundle arrays I/O access device is presented in this paper. An optoelectronic recirculating Banyan network based on CMOS/SEED smart pixel device is used in this configuration. Thirty-two X two single-mode fiber bundle array and 32 X 2 multi- mode fiber bundle array are fabricated respectively based on the features of high density, high precision and array permutation of the CMOS/SEED optoelectronic integrated devices. The measuring results show that the center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125 micrometer, and the spacing between …

The Ac Impedance Analysis For Pluse Oxide Film Of Aluminium Alloy, Ailing Du, Xicheng Ma, Heming Zhang

Journal of Electrochemistry

Bode diagrams for aluminum PC (abbreviated from pulse current) oxide films were first obtained by AC impedance measurements in a wide range of frequency.The experimental results show that different kinds of electrical equivalent circuits can be used for representing PC films and DC (abbreviated from direct current) oxide films separately,the main differences between them are their porous layers,the PC films are more even with little defects.Those are also verified by SEM and V I characteristic curve measurements.

Study On Synthesizing Of 2_Methylbutanoic Acid By Indirect Electrooxidation, Chongta Zhao, Zeshan Zhu

Journal of Electrochemistry

The working conditions of synthesizing 2_methylbutanoic acid by oxidizing 2_methyl_1_butanol with tetrabutylammonium hydrosulfate(TBAS) or tetrabutylammonium perchlorate(TBAP) as phase transfer catalyst in sulfuric acid Cr(Ⅵ) oxidation medium was studied. The Cr(Ⅵ) oxidation medium could be electrolytic regenerated from Cr(Ⅲ), during above oxidation reaction.Under the optinum condition,the yield of 2_methylbutanoic acid is more than 95%.

Electrochemical Synthesis Of Fes Electrode And Its Behavior Measurement, Congsheng Guan

Journal of Electrochemistry

The Potential for the electrochemical synthesis of FeS electrode has been obtained by cyclic voltammetry.FeS electrodes were synthesiaed by controlling Fe electrode at -1.0 V in LiCl_KCl_Li 2S and Li(FClI)_Li 2S melts and their behavior were measured also.The FeS electrode synthesized in molten Li(FClI)_Li 2S has the best charge and discharge properties.

Deactivation Of Nickel Oxide/Hydroxide To Electrooxidation Of H 2po - 2 Anions On Nickel Electrodes In Alkaline Solutions, Taixiang Jiang, Huihuang Wu

Journal of Electrochemistry

Electrooxidation of hypophosphite anions on polycrystalline nickel in alkaline solutions has been investigated by cyclic voltammetry and open circuit potential measurements.The results are explained based on the mechanism that the first step of hypophosphite oxidation is the adsorption of hypophosphite ions on nickel,followed by the homolysis of its hydrogen bond with the formation of radicals.The oxidation of hypophosphite on nickel in alkaline medium occurs at lower potentials between ca.-0.8 V—-1.1 V(SCE)and phosphite ion is the only oxidation product.There is no indication of hypophosphite oxidation at higher potentials.Severe deactivation of the surface occurs when the nickel surface is covered with surface …

Structural And Electrochemical Studies On Lithium Manganese Oxide Containing Li + Prepared By Hydrothermal Method For Lithium Ion Batteries, Deyao Liu, Jinkua You, Wei Chu, Yong Yang, Zugeng Lin

Journal of Electrochemistry

In this paper, Todorokite manganese oxides containing Li + with large tunnel structure(sample M5) have been synthesized by hydrothermal methods from natural manganese oxide nano fiber (sample M4). The structure and composition of the samples were characterized and analyzed by XRD, ICP, TGA and DTA. Its electrochemical behavior as a cathode materials for rechargeable lithium ion insertion were studied by galvanostatic charge/discharge measurements. XRD results show that the sample M4 is mainly composed of Birnessite and Vernadite structure. Although the sample M4 shows a high initial capacity of approximately 150 mAh/g, its performances decrease gradually over 30 cycles. It is …

The Techniques Of The Paired Electrosynthesis, Hongkun Zhang, Dengping Gu

Journal of Electrochemistry

In this Paper,we introduce our work on paired electrosynthesis.In conjunction with our research practice,we introduce electrolytic conditions,such as material of electrode ,courrent density and electrolytic temperature etc,as reference for researcher.We categorize the paired electrosynthesis techniques to widen our view on the paired electroorganic synthesis and to promote the deveopments of paired electrosynthesis techniques.

Differential Reflection Phase Shift Under Conditions Of Attenuated Internal Reflection, R. M.A. Azzam

Electrical Engineering Faculty Publications

The angle-of-incidence dependence of the differential reflection phase shift Δ between p and s polarizations is considered a function of the real and imaginary parts of the relative complex dielectric function ε of an interface in the domain of fractional optical constants, i.e., under conditions of internal reflection. The constraint on complex ε such that oscillatory and monotonic angular responses are obtained is determined. A sensitive and stable technique, which is based on attenuated internal reflection ellipsometry between the Brewster angle and the critical angle, is proposed for measuring small induced absorption (ε_i∼10⁻⁵) in the medium …

Guest Editorial: Special Section On Acousto-Optic Devices And Optical Information Processing: Research And Developments, Partha P. Banerjee, Ting-Chung Poon

Electrical and Computer Engineering Faculty Publications

This guest editorial provides an overview of the topical area and an introduction to the articles featured in the special section.

Examination Of Beam Propagation In Misaligned Holographic Gratings And Comparison With The Acousto-Optic Transfer Function Model For Profiled Beams, Monish Ranjan Chatterjee, David D. Reagan

Electrical and Computer Engineering Faculty Publications

A transfer function formalism developed earlier for the propagation of profiled optical beams through acousto-optic Bragg cells is revisited and applied to a thick holographic grating. The results based on the holographic coupled wave model and the acousto-optic multiple scattering model are shown to be compatible, and equivalent parameters such as the Q and grating strength are defined for the two systems. Results for a Gaussian spatial profile are numerically computed and compared. For the holographic grating, a profiled beam may be interpreted as an angular misalignment or Bragg-angle mismatch problem. The case of Bragg-wavelength mismatch is also investigated for …

Newton Parameter Update Algorithm For Recurrent Neural Networks Applied To Adaptive System Identification And Control, Donald Allen Gates

Electrical & Computer Engineering Theses & Dissertations

This paper shows that the combination of a second-order neural network parameter update algorithm and internal network feedback can be effectively used for adaptive, nonlinear, dynamical system identification and control. Adaptive neural identification and control algorithms are typically utilized for real-time applications where the rate of adaptation is often critical. A fast, adaptive network parameter update algorithm is presented.

Simulation results show that this algorithm is capable of quickly identifying and adapting to changes in system parameters, making it feasible to use for real-time control and fault accommodation applications.

Laser Beam Profile Deformation Effect During Bragg Acousto-Optic Interaction: A Non-Paraxial Approximation, Ray S. Huang, Chen-Wen Tarn, Partha P. Banerjee, Doungchin Cao

Electrical and Computer Engineering Faculty Publications

It is commonly known that the spatial profiles of the diffracted light beams during Bragg acousto-optic interaction are distorted due to the Bragg angle selection mechanism. All the conventional studies on this effect use the paraxial approximation. But this approximation should be amended when the incident angle of the light is large enough that the diffracted light waves do not propagate closely along the optic axis of the acousto-optic diffraction system. By using a spatial Fourier transform approach, we rigorously study the light beam profile deformation effect of the diffracted light during the Bragg acousto-optic interaction beyond the paraxial approximation. …

Probabilistic Crowding: Deterministic Crowding With Probabilistic Replacement, Ole J. Mengshoel, David E. Goldberg

Ole J Mengshoel

This paper presents a novel niching algorithm, probabilistic crowding. Like its predecessor deterministic crowding, probabilistic crowding is fast, simple, and requires no parameters beyond that of the classical GA. In probabilistic crowding, subpopulations are maintained reliably, and we analyze and predict how this maintenance takes place.

This paper also identifies probabilistic crowding as a member of a family of algorithms, which we call integrated tournament algorithms. Integrated tournament algorithms also include deterministic crowding, restricted tournament selection, elitist recombination, parallel recombinative simulated annealing, the Metropolis algorithm, and simulated annealing.

Parallel Digital Signal Processing On A Network Of Personal Computers Case Study: Space-Time Adaptive Processing, Fernando Silva

Theses and Dissertations

Network based parallel computing using personal computers is currently a popular choice for concurrent scientific computing. This work evaluates the capabilities and the performance of the AFIT Bimodal Cluster (ABC); a heterogeneous cluster of PCs connected by switched fast Ethernet and using MPICH 1.1 for interprocess communication for parallel digital signal processing using Space Time Adaptive Processing (STAP) as the case study. The MITRE RT_STAP Benchmark version 1.1 is ported and executed on the ABC, as well as on a cluster of six Sun SPARC workstations connected by a Myrinet network (the AFIT NOW), and on a IBM SP for …

Investigation Of Solution Chemistry In Crevice Of Carbon Steel And Its Anodic Polarization Behavior, Zhuo Chen, Cuiwei Du, Bei Cao, Yinshun Wu, Hai Yang, Zhengrong Zhang

Journal of Electrochemistry

A self_made wedge_shaped simulated crevice apparatus was designed to investigate the solution chemistry in crevice of carbon steel and its anodic polarization behavior. For carbon steel with 3.5%(wt) NaCl , the change and the distribution of electrode potential , concentration of Cl- and pH value of solution in the crevice, and the current density of metal in the crevice were measured respectively under various conditions of anodic polarization. The results showed that without polarization the metal about 2 cm away from the opening of the crevice was attacked preferentially because of its lowest free corrosion potential. The anodic polarization promoted …

Oxidation And Adsorption Of Deoxyribonucleic Acid At Highly Ordered Pyrolytic Graphite And Glass Carbon Electrode, Jianzhang Zhou, Lingling Wu, Jin Luo, Zhonghua Lin

Journal of Electrochemistry

It is shown that calf thymus DNA(CT DNA) can be adsorbed at highly ordered pyrolytic graphite(HOPG) electrode and detected by differential pulse voltammetry(DPV) and electrochemical atomic force microscopy(ECAFM). It is found that controlled potential pre-polarization influences largely the adsorption of dsDNA while it has little influence on ssDNA. It is demonstrated that ECAFM is useful to exploit adsorption of DNA at HOPGE. The pattern of adsorption of DNA at HOPG electrode that fits best with the experimental data is proposed. The results aslo shows that UV/Vis reflection spectroscopy, which has not been used in studying electrochemical behavior of DNA, is …

Influence Of Ptfe And Nafion On The Utilizationefficiency Of Pt/C Catalyst In Pemfc, Xiaoliang Cheng, Baolian Yi, Jingxin Zhang, Ming Han, Yaguang Qiao

Journal of Electrochemistry

With cycling voltammetry curve(C-V), TEM and SEM photographs, the influence of PTFE and Nafion on the platinum utilization in catalyst layer of PEMFC was investigated. The results show that in gas diffusion electrode, the blocking effect of PTFE in the platinum utilization is not pronunced. In the thin_film catalyst layer, the electron conduct of the catalyst was blocked by the nafion solid and this caused the decrease of platinum utilization. With the increase of the nafion content in the catalyst layer, both platinum utilization and the electron conductivity decreased in the catalyst layer. Because the molecule size of nafion is …

Preparation And Application Of Gold_Film On The Surface Of Bacterial_Modified Carbon Paste Electrode, Rongzong Hu, Yanping Ruan, Hao Xu, Jinkun Fu, Weide Zhang, Wenyun Hu

Journal of Electrochemistry

A novel method for preparation of gold_film composed of ultra_fine gold particles was reported in this paper. The gold_film was prepared by electrochemical method on the surface of the paste electrode modified with the strain Bacillus sp. D01 which has strong ability to absorb and reduce Au3+. In addition, this paper reported an experimental method of determining trace amount of Cu2+ in water solution using cathodic stripping analysis to estimate the performances of the obtained gold_film. The experimental results indicated that this new method for preparation of gold_film is simple. The obtained gold_film electrode is stable and sensitive to determining …

Zro2zro2_Y2o3 Coatings Deposited By High Energy Pulse, Weiping Yu

Journal of Electrochemistry

The basic rule and influence factors on deposition of ZrO2 and ZrO2_Y2O3 coatings by high energy pulse were studied. After the oxidizing experiment in air at 1 000 for 100 h, it was shown that the oxidation resistance of 18_8 stainless steel was marketly enhanced by depositing ZrO2 and ZrO2_Y2O3 coatings. The oxidation resistance was increased about 20 times and the oxide scale spallation resistance was increased about 100 times.

Electrochemical Behavior Of Riboflavin On Glassy Carbon Electrode, Hong Li, Lincai Jiang

Journal of Electrochemistry

The electrochemical behavior of riboflavin(RF) on glassy carbon has been investigated by using potential sweep,rotating ring_disc electrode and the measurement of differential capacitance. It is shown that a single well_behaved oxidation_reduction wave corresponding to a reversible two_electrons reaction apears in medium of pH<6,and the adsorption of RFH2 formed by electro_reduction is weak and hence its solubility is good.In medium of pH>6,there are two separating but overlapping partly oxidation_reduction waves corresponding to two_step one_electron reaction.The adsorptions of RFH and RFH2 produced by reduction reactions in medium of 610,the solubilities of the adsorbed species produced by electro_reduction are good.

The Behaviors Of Capacity Loss Of Limn2o4 Cathodeat Elevated Temperatures, Xiaohong Hu, Hanxi Yang, Xinping Ai, Shengxian Li, Xinlin Hong

Journal of Electrochemistry

The capacity loss of spinel LiMn2O4 cathode at elevated temperatures was evaluated by constant current charge_discharge methods and it was found that serious capacity loss and cycleability decrease occured at above 50 , especially for the charged cells. The mechanisms for this phenomena were examined by atomic emission and infrared spectrometry of the electrolyte, XRD measurment of the cycled elecrode and microelectrode voltammetry of LiMn2O4 at room and elevated temperatures. The results showed that with increasing temperature, Mn and Li ions tended to redistribute partly in the spinel framework due to the disproportion of Mn3+ ions and this results in …

In Situ Ftir Spectroelectrochemical Study Of Palladium Hexacyanoferrate Thin Film Deposited On Glassy Carbon Electrode, Aili Bo

Journal of Electrochemistry

The electrochemically deposited Palladium hexacyanoferrate thin film on Glassy Carbon electrode (PdHCF|GC) has been studied in HCl, KCl and NaCl solutions by in_situ external reflection FTIR spectroelectrochemical technique. It is found that the behavior of the electroactive PdHCF film can be understood in terms of two states: Pd2Fe(II)(CN)6 formed in the inner layer and (M+)2Fe(II)(CN)6 (M+: electrolyte cation) formed in the outer layer. The inner layer is oxidized at Em=0.87 V in 1 mol/L KCl, while for the outer layer Em=0.77 V(vs. Ag/AgCl). In 1 mol/L NaCl or HCl solutions, half_wave potentials of these two layers are not well resolved, …

Output Control Of Vertical Microcavity Light Emitting Device, James A. Lott

AFIT Patents

An improved intracavity sensor based output power control for microcavity light emitting devices. An improved phototransistor transducer is both configured and physically disposed so that it passively transmits the spurious optical energy output of the microcavity light emitting device while simultaneously generating a light determined electrical signal of easily used large magnitude that is nearly free of error. The base-collector region of the transistor is disposed with a quantum well absorbing layer and produces a signal responsive to a selected emission wavelength. The configuration of the optical energy communicating transducer is arranged so that it is improved in sensitivity and …

Development And Testing Of An Ac Micro Hollow Cathode Simulator, Thomas E. Caldwell

Electrical & Computer Engineering Theses & Dissertations

The use of AC source plasma discharge devices in applications such as material processing and film deposition has increased in recent years due to improvements in discharge efficiency made possible by devices such as the micro hollow cathode. Designing hollow cathodes for specific applications requires an understanding of the processes that govern the discharge. Simulation is an inexpensive tool for understanding hollow cathode operation and optimizing the device for specific applications. This thesis describes the development of an AC micro hollow cathode simulator. It details the theoretical models used in the simulation and presents the results of test cases intended …