Open Access. Powered by Scholars. Published by Universities.®

Engineering Science and Materials Commons

Open Access. Powered by Scholars. Published by Universities.®

2000

Discipline
Institution
Keyword
Publication
Publication Type

Articles 31 - 60 of 62

Full-Text Articles in Engineering Science and Materials

Preparation And Characteristics Of A Enzyme Electrode Based On Immobilization Of Tyrosinase In Electropolymerized Polypyrrole Film, Liu-Shui Yan, Qia Wei, Cheng-Yi Wang, Rong-Rong Shi, Xiao-Tong Ma May 2000

Preparation And Characteristics Of A Enzyme Electrode Based On Immobilization Of Tyrosinase In Electropolymerized Polypyrrole Film, Liu-Shui Yan, Qia Wei, Cheng-Yi Wang, Rong-Rong Shi, Xiao-Tong Ma

Journal of Electrochemistry

A sensitive and stable amperometric enzyme electrode was constructed, based on the immobilization of tyrosinase in potentiostatically electropolymerized polypyrrole film at a platinum electrode. The influence of pH and potential on immbilization was discussed. SEM micrographs and CV curves of films obtained before and after incorparation of tyrosinase molecular were analyzed and compared each other. The enzyme electrode responds linearly to p-cresol over a concentration range of 5×10 -8 ~1×10 -6 mol/L with an optimum pH of 6.6, It exhibited kinetic characteristics of the typical enzyme-catalyzed reaction with an apparent Michaelis constant of 2.2 ×10 -5 mol/L.


Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides May 2000

Template Synthesis And Uv-Vis Absorption Spectra Of The Nanowire Arrays Of Cadmium Chalcogenides

Journal of Electrochemistry

XU Shi_min, XUE Kuan_hong , KONG Jing_lin, SUN Dong_mei, FENG Yu_ying, LU Hai_yan (Dept. of Chem., Nanjing Normal Univ., Nanjing 210097, China) WANG Guang_hou (National Laboratory of Solid State Microstructures, Nanjing Univ., Nanjing 210093, China)The porous alumina membrane formed in the anodic oxidation of highly pure aluminum foil has attracted a great deal of attention in recent years [1] . It can be served as a desired template to prepare nanometer scale materials [2] due to its unique structure of discrete and cylindrical nanopores, paralleled one another, with the homogeneous size and distribution [3] . Chalcogenide semiconductors have promising prospect …


Effects Of Temperature On The Proton Diffusion Of Doped Ni(Oh)_2, Jian-Hua Liu, Jing-Wu Yang, Zhi-Yuan Tang May 2000

Effects Of Temperature On The Proton Diffusion Of Doped Ni(Oh)_2, Jian-Hua Liu, Jing-Wu Yang, Zhi-Yuan Tang

Journal of Electrochemistry

The Chronoamperometry of powder spherical Ni(OH) 2 microelectrode was used to study the proton diffusion coefficients of Ni(OH) 2. The proton diffusion coeefficients and the apparent diffusion active energy in anode and cathode processes at different temperature were obtained. Compared with pure Ni(OH) 2, the apparent diffusion active energy( E a) of Ni(OH) 2 doped with Co and Co+Zn was decreased and the diffusion constant( D o) was increased in the anode and the cathode processes, respectively, the effect of Co was greater. In contrast, for Ni(OH) 2 doped with Zn, its E a was increased and D o was …


Study On The Effect Of Sodium Ion On Cycle Performance Of Lithium/Improved Graphite Lithium Ion Cell, Wen-Huang Huang, Yu-Shun Yan, Chun-Rong Wan, Chang-Yin Jiang May 2000

Study On The Effect Of Sodium Ion On Cycle Performance Of Lithium/Improved Graphite Lithium Ion Cell, Wen-Huang Huang, Yu-Shun Yan, Chun-Rong Wan, Chang-Yin Jiang

Journal of Electrochemistry

The different concentration of Na + was introduced into the non_aqueous eletrolyte system EC/DEC/LiClO 4 with 4A molecular sieve and lithiated 4A molecular sieve,by which the trace amount of water was removed.The concentrations of Na + and Li + were determined by atomic adsorption spectrometry. The cycle performance of lithium/improved graphite cells was then examined by charging and discharging under the constant electric current.The results demonstrated that the cycle performance of the cells was destroyed by the high concentration of Na + under the small electric current.With the increase of electric current,the cell became less sensitive to the concentration of …


Determination Of Kinetic Parameters Of Enzyme-Immunoelectrode For Sec Assay, Sa-Ying Dong, Xin-Miao Liu, Yuan-Zhi Wang, Guang-Zhang Chen, Ming-Xiang Lv, Bo-Yi Tian May 2000

Determination Of Kinetic Parameters Of Enzyme-Immunoelectrode For Sec Assay, Sa-Ying Dong, Xin-Miao Liu, Yuan-Zhi Wang, Guang-Zhang Chen, Ming-Xiang Lv, Bo-Yi Tian

Journal of Electrochemistry

Reaction mechanism of enzyme immunoelectrode is studied by potentiostatic. Rotating disk electrode is used to determine the controlling step of bioelectrode. Under different potentials and different modifying conditions, kinetic parameters of bioelectrodes were measured on the base of electrochemical impendance spectra. At the same time, these parameters are compared and discussed.


The Influence Of Surface Diffusion Of Adsorbed Intermediate On Hydrogen Evolution Reaction At Pt/Nafion Composite Electrodes, Wei-Yi Tu, Lei Su, Wen-Jun Liu, Bing-Liang Wu May 2000

The Influence Of Surface Diffusion Of Adsorbed Intermediate On Hydrogen Evolution Reaction At Pt/Nafion Composite Electrodes, Wei-Yi Tu, Lei Su, Wen-Jun Liu, Bing-Liang Wu

Journal of Electrochemistry

The decrease of over_potential of hydrogen evolution reaction at Pt black powder/Nafion microelectrode, comparing that of the Pt microdisk/Nafion electrode, was evident from the polarization curves of the Pt microdisk/Nafion electrode, platinized Pt micrdisk/Nafion electrode and Pt black powder/Nafion microelectrode. It is also evidenced by a plane Pt electrode with an additional free Pt surface. The surface diffusion and the surface recombination reaction of the adsorbed intermediate at the free surface of the Pt particles were supposed. It is an additional reaction path that induced the decrease of the concentration of the adsorbed intermediate. Thereby, the over_potential decreased.


Electrochemical Quartz Crystal Microbalance Study On The Promoted Electron Transfer Process At Gold Electrode, Xia-Qin Wu, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang May 2000

Electrochemical Quartz Crystal Microbalance Study On The Promoted Electron Transfer Process At Gold Electrode, Xia-Qin Wu, Zhe-Su Wang, Xiao-Yun Meng, Zong-Rang Zhang

Journal of Electrochemistry

The adsorption behavior of amino acids, such as L_cysteine, histidine and arginine at gold_quartz crystal microbalance (Au_QCM) was investigated. The adsorption quantity of cysteine is more appreciable than others because of the stronger interaction between its thiol group and the gold electrode surface. The electron_transfer process of superoxide dismutase(SOD) in presence of cysteine at Au_QCM has also been studied using the electrochemical quartz crystal microbalance (EQCM) technique which reveals clearly the quasi_reversible electron_transfer process accompanied by the frequency shift cycle. The reversible adsorption and disorption processes are discussed.


Study On Carbon From Pyrolyzing Phenol-Formaldehyde Resin For The Negative Electrode Of Li-Ion Secondary Battery, Zhi-Yuan Tang, Xin-Guo Zhuang, Yu-Mei Zhai, Jian-Gang Li, Jian-Jun Xue, Chun-Yan Liu May 2000

Study On Carbon From Pyrolyzing Phenol-Formaldehyde Resin For The Negative Electrode Of Li-Ion Secondary Battery, Zhi-Yuan Tang, Xin-Guo Zhuang, Yu-Mei Zhai, Jian-Gang Li, Jian-Jun Xue, Chun-Yan Liu

Journal of Electrochemistry

Li_ion secondary batteries negative electrodes were prepared by low temperature (<1 000 ℃) pyrolysis of commercial phenol_formaldhyde resin. A thermogravimetric analysis (TGA) and an X_ray diffraction (XRD) studies were peoformed for the pyrolytic carbonaceous materials. The results indicated that these samples are amorphous polyacenic structure materials. With increasing pyrolytic temperature, these materials become structurally order, and the first charge_discharge special capacities reduce. The specific capacities base on pyrolytic temperature, involving lithium storage nanometer cavities.


An Investigation On The Corrosion Potential Imaging At The Interface Of Concrete/Reinforcing Bar In Corrosion Media, Rong-Zong Hu, Chang-Jian Lin, Xiang Zhou, Jian-Guang Tan, Xiong-Chao Zhao May 2000

An Investigation On The Corrosion Potential Imaging At The Interface Of Concrete/Reinforcing Bar In Corrosion Media, Rong-Zong Hu, Chang-Jian Lin, Xiang Zhou, Jian-Guang Tan, Xiong-Chao Zhao

Journal of Electrochemistry

The iron array electrode covered with concrete as a new electrochemical technique is applied to map the potential imaging and to investigate on the iron electrode corrosion process under concrete: In Cl - solution the corrosion of the iron array electrode covered with concrete had been prevented for a short term since the concrete protection, but the corrosion still occurreed and developed after immersed for a long time. In SO 4 2- solution although the sample had being immersed for a long time and the concrete was possibly broken, the corrosion did not develop. In Cl - solution the corrosion …


Electrocrystallization Mechanism And Grain Sizes Of Ni-W-B Alloy Eletrodeposits, Fang-Zu Yang, Gang-Min Cao, Xiao Hu, Shu-Kai Xu, Shao-Min Zhou May 2000

Electrocrystallization Mechanism And Grain Sizes Of Ni-W-B Alloy Eletrodeposits, Fang-Zu Yang, Gang-Min Cao, Xiao Hu, Shu-Kai Xu, Shao-Min Zhou

Journal of Electrochemistry

The electrodeposition characteristics and grain sizes of Ni_W_B alloy have been studied by cyclic voltammetry, potentiostatic step and X_ray diffraction (XRD). The results showed that Ni_W_B alloy electrodeposit obtained from the solution containing ammonium citrate as a complexing agent was presented in the lower electrochemical activity compared with Ni_W alloy. Based upon the i~t curves of potentiostatic step, it was revealed that electrocrystallization of Ni_W_B alloy on glassy carbon followed the mechanism of instantaneous nucleation and three dimensional growth with diffusion controlled. The crystal nucleus number on the surface of electrode was raised by the increase of overpotential. According to …


Finite Element Analysis Of A Composite Cylindrical Shell With A Cutout Under A Fatigue Load, Joshua T. Boatwright Mar 2000

Finite Element Analysis Of A Composite Cylindrical Shell With A Cutout Under A Fatigue Load, Joshua T. Boatwright

Theses and Dissertations

A higher-order shell theory is used to analyze compressive and tensile loads on a graphite/epoxy laminated cylinder containing a square cutout. The Hashin failure criterion is used to determine failure in the fiber, matrix, or lamination. Once failure occurs, the appropriate stiffness terms are reduced. This failure causes a redistribution of stress, leading to further failure. In order to account for the loss of residual strength due to cyclic loading, the stiffness matrix is further reduced at each new increment of load or displacement. The objective is not to determine the S-N curve for the material, but rather to determine …


Mechanics Of A Functionally-Graded Titanium Matrix Composite, G. Brandt Miller Mar 2000

Mechanics Of A Functionally-Graded Titanium Matrix Composite, G. Brandt Miller

Theses and Dissertations

Functionally-graded Titanium Matrix Composites, (F/G TMCs) combine the ideal properties of titanium matrix composites with the more practical machining qualities of monolithic (unreinforced) alloy. This material shows great promise in application to aerospace structural components - even in parts whose design requirements have defied the use of composite materials in the past. Successful implementation of such a material would lead to enhanced aircraft performance. However, the basic properties of a functionally-graded titanium matrix composite need to be investigated. The composite/alloy transition region, or joint area, may be less strong than its constituents and therefore determine the overall performance of the …


Studies Of Abnormal Infrared Effects Of Nanometer Thin Films Of Transition Metals And Alloys In Acid Solutions, Shi-Gang Sun, Ming-Sen Zheng, Guo-Qiang Lu, Li-Rong Cai, Sheng-Pei Cehn, Xiao-Yin Xiao Feb 2000

Studies Of Abnormal Infrared Effects Of Nanometer Thin Films Of Transition Metals And Alloys In Acid Solutions, Shi-Gang Sun, Ming-Sen Zheng, Guo-Qiang Lu, Li-Rong Cai, Sheng-Pei Cehn, Xiao-Yin Xiao

Journal of Electrochemistry

The adsorption of CO on electrodes of nanometer thin films of transition metals (Pt, Pd, Rh, Ru) and alloys (PtPd, PtRu) prepared under cyclic voltammetric conditions has been studied by in situ FTIR spectroscopy. The abnormal infrared effects (AIREs) have been explored as a novel and general phenomenon. The AIREs consist mainly in the inversion of the direction of IR band and the significant enhancement of IR absorption by adsorbed CO species. It was revealed that the enhanced IR absoroption of adsorbed species in AIREs depends strongly on the nature of metal or alloy, and on the structure and the …


Sprayed And Thermally Evaporated Carbon Films As Anodes For Lithium Ion Batteries, Shu-Gao Zhang, M.Schleich Donald Feb 2000

Sprayed And Thermally Evaporated Carbon Films As Anodes For Lithium Ion Batteries, Shu-Gao Zhang, M.Schleich Donald

Journal of Electrochemistry

Carbon films were made using spray_thermal evaporation from a kind of pyrolytic carbon powder. The films obtained with graphite structure were both potentio_statically and galvanostaically tested. Cycling patterns indicated a reduction peak on the first cycle corresponding to the formation of solid electrolyte interface, and the capacity values and x values were quite acceptable compared to theoretical ones when charging_discharging current density was suitable. Based on the experimental results, the obtained carbon films could be used as anode materials for relatively determining the electrochemical performances of cathode materials.


The Study On Fabricating Thin Electrodes For Polymer Electrolyte Membrane Fuel Cells(Pemfc), Yong-Sheng Yang, Jing-Hua Liu, Chang-Peng Liu, Gong-Quan Sun, Chang-Zhi Li, Tian-Hong Lu Feb 2000

The Study On Fabricating Thin Electrodes For Polymer Electrolyte Membrane Fuel Cells(Pemfc), Yong-Sheng Yang, Jing-Hua Liu, Chang-Peng Liu, Gong-Quan Sun, Chang-Zhi Li, Tian-Hong Lu

Journal of Electrochemistry

To lower platinum loading in electrodes for polymer electrolyte membrane fuel cell,a new thin electrode fabrication technique(TEFT) was developed in this work.A series of low Pt loading electrodes with smooth and uniformed surface were fabricated by the TEFT.As a result,the maximum power density of the cell with platinum loading of 1 mg/cm 2 and Nafion 117 membrane as electrolyte was up to 0.3 W.cm -2 .Moreover,the effects of PTFE and Nafion content in cathodes on the performance of PEMFC with low Pt loading electrodes(1 mg Pt/cm 2)were examined systematically.


Studies Of The Preparation Of Electrodes From Lead Carbonate For Lead-Acid Battery Ⅱ.The Preparation Of Paste Electrodes, Zhong-Xu Dai, Di-Hua Wang, Hao-Hao Ke, Jin-Yun Zou, Yun-Hong Zhou Feb 2000

Studies Of The Preparation Of Electrodes From Lead Carbonate For Lead-Acid Battery Ⅱ.The Preparation Of Paste Electrodes, Zhong-Xu Dai, Di-Hua Wang, Hao-Hao Ke, Jin-Yun Zou, Yun-Hong Zhou

Journal of Electrochemistry

The positive and negative pastes were prepared by mixing PbCO 3 and H 2SO 4 solution as well as relative additives, respectively. The effects of the various formation methods and the charge/discharge conditions on discharge capacity and active material utilization of both electrodes were examined. The results indicate that the performance of the positive electrode formed at 2.0 mA/cm 2 is better than that formed at higher current density under the same charge/discharge condition, the PAM utilization reaches 74.4 % under discharging at 2.0 mA/cm 2; and the property of the negative electrode formed by unsymmetrical square wave is superior …


Electrochemical Characterization Of Ir-Ta-Ti Metal Oxide Coated Titanium Anodes, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen Feb 2000

Electrochemical Characterization Of Ir-Ta-Ti Metal Oxide Coated Titanium Anodes, Ting-Yong Wang, Li-Kun Xu, Guang-Zhang Chen

Journal of Electrochemistry

Ir_Ta_Ti metal oxide coated titanium anodes of variable composition were prepared by thermal decomposition. Their micro morphorogies and electrochemical properties were characterized by scanning electron microscope, open circuit potential, cyclic voltammetry, consumption rate measurements and accelerated life test. The SEM results indicated that all coatings were of a porous and cracked_mud microstructure influenced greatly by the composition of coatings. The electrochemical measurements showed that the Ir_Ta_Ti ternary oxide_coated anodes exhibited excellent electrochemical activity and electrochemical stability in both acidic media and seawater which were affected by the composition and microstructure of the coatings. Owing to good corrosion resistance and low …


Study On Preparation Of Coarse And Fine Γ-Lialo_2 Mixed Powder Used For Mcfc Matrix, Hua-Xin Lin, Bao-Lian Yi, Lian-Ying Kong, En-Jun Zhang, Li Zhou, Feng-Xia Wang Feb 2000

Study On Preparation Of Coarse And Fine Γ-Lialo_2 Mixed Powder Used For Mcfc Matrix, Hua-Xin Lin, Bao-Lian Yi, Lian-Ying Kong, En-Jun Zhang, Li Zhou, Feng-Xia Wang

Journal of Electrochemistry

Coarse α_LiALO 2 powder was transferred completely to γ_LiAlO 2 at 900 ℃ for ten hours.Fine γ_LiAlO 2 powder was prepared by “chloride” synthesis. MCFC matrix was fabricated by mixing the coarse and fine γ_LiAlO 2 powder and by tape cast.The out'put voltage of the cell assembled with the matrix was 0.85 and 0.75 V respectively at 200 and 300 mA/cm 2,and power density was about 250 mW/cm 2.The performance of the matrix fabricated with the mixed powder was obviously more advanced than that of the matrix fabricated with only coarse γ_LiAlO 2 powder.


Effect Of Different Species Of Cobalt Additive On Performance Of Nickel Hydroxide Electrode, Xian-Xia Yuan, Yin-Dong Wang, Feng Zhan Feb 2000

Effect Of Different Species Of Cobalt Additive On Performance Of Nickel Hydroxide Electrode, Xian-Xia Yuan, Yin-Dong Wang, Feng Zhan

Journal of Electrochemistry

Performances of nickel electrodes when adding or without adding Cobalt in different forms were studied, the results were interpreted by cyclic voltammetry(CV)and electrochemical impedance spectroscope(EIS). It was demonstrated that the additions of Co,CoO,CoO+Co by mechanically mixing with Ni(OH) 2 all can improve the performance of nickel electrode to some extent,and when Co is added in the form of CoO the best performance can be obtained. This can be mainly attributed to the fact that three kinds of Co additives all improved the structure of nickel hydroxide and the ability of H + in electrolyte transporting through the material,hence the reversibility …


Investigations Of Lithium Ion Battery Electrolyte Solution, Jing-Li Han, Qing-Guo Liu Feb 2000

Investigations Of Lithium Ion Battery Electrolyte Solution, Jing-Li Han, Qing-Guo Liu

Journal of Electrochemistry

Synthesis and electrochemical investigations of {LiB[(SO 3)C 6H 3(O)(COO)]OC 6H 5}in EC/DMC or DMSO/PC mixtures are presented.


Electro-Oxidation Of Glyoxal To Glyoxalic Acid, Yin-Sheng Chen, Xin-Sheng Zhang, Jun Hu, Ying-Chun Dai Feb 2000

Electro-Oxidation Of Glyoxal To Glyoxalic Acid, Yin-Sheng Chen, Xin-Sheng Zhang, Jun Hu, Ying-Chun Dai

Journal of Electrochemistry

An investigation has been made to obtain the glyoxalic acid by the electrochemical oxidation of glyoxal solution with hydrochloric acid under various experimental conditions.The cell used consists of a lead cathode, a DSA anode and a cation_exchange membrane of model CM001.The current efficiency and yield for glyoxalic acid generation were 80.0% and 91.1% respectively, under optimal operating conditions: velocity of electrolyte flow 1.4 m·s -1 ,current density 450A·m -2 ,temperature 30~40 ℃,initial concentration of glyoxal and hydrochloric acid 9.1%~16.0%, 4%~6%, respectively.


An Eis Study On The Synergetic Filming Between Cathodic Protection And The Corrosion Inhibitor, Yong-Tao Zhao, Jian-Hua Wu, Jian-Hua Qian, Hui Yu Feb 2000

An Eis Study On The Synergetic Filming Between Cathodic Protection And The Corrosion Inhibitor, Yong-Tao Zhao, Jian-Hua Wu, Jian-Hua Qian, Hui Yu

Journal of Electrochemistry

The electrochemical impedance spectroscope(EIS) of 907A steel in seawater was investigated to study the film formation and destruction. The corrosion protection mechanism of the synergy interaction between cathodic protection and YKI_5 corrosion inhibitor(a mixture of polyhydric alcohol phosphate ester, phosphate and polyphosphate) is discused. Typical EIS spectral changes were clearly observed during the film formation and destruction processes. EIS results indicated that the film seemed to formed a multi_layered structure which consist of an inner layer(this may be an inhibitor_metal complex layer) and many outer layers of calcareous deposits. The film possesses of good persistency under the testing conditions.


Fabrication And Examination Of Reduced Temperatrue Solid Oxide Fuel Cell Using A Supported Thin Ysz Electrolyte Substrate, Yi-Huang Zhang, Yong-Lei Dong, Yi Jiang, Zhi-Gui Lu, Jing-Wang Yan Feb 2000

Fabrication And Examination Of Reduced Temperatrue Solid Oxide Fuel Cell Using A Supported Thin Ysz Electrolyte Substrate, Yi-Huang Zhang, Yong-Lei Dong, Yi Jiang, Zhi-Gui Lu, Jing-Wang Yan

Journal of Electrochemistry

By using a cost_effective wet process,dense yttria stabilized zirconia (YSZ) films on Ni_YSZ anode substrates have been prepared successfully.The YSZ film was characterized to be around 10 μm in thickness,sufficiently dense,uniform and crack free.A single solid oxide fuel cell fabricated from the supported YSZ film electrolyte on the anode substrate and a LSM cathode prepared on the YSZ film was tested.The power density reached to 0.1 W/cm 2 at 800 ℃,showing a reasonable performance.Further analysis on both electrodes shows that the anodic overpotential was much larger than IR drop (including YSZ resistance and contact resistance) and than the cathodic overpotential.The …


Studies On Electrochemical Synthesis Of 4,5-Disubstituted-1,2- Benzoquinones And The Reaction Mechanism, Xian-Zhang Bu, Gui-Wu Xiao, Lin Ma, Xing-Chum He, Ling-Quan Gu Feb 2000

Studies On Electrochemical Synthesis Of 4,5-Disubstituted-1,2- Benzoquinones And The Reaction Mechanism, Xian-Zhang Bu, Gui-Wu Xiao, Lin Ma, Xing-Chum He, Ling-Quan Gu

Journal of Electrochemistry

The oxidation peak potentials( E p) of alinine derivates and catechol in 0.1 mol/L KCl+15% alcohol solution were measured by cyclic voltammograms technique. The electrochemical oxidation condition was set according to the E p. Three derivates of 4,5_disubstituted _1,2_benzoquinones were prepared via electrochemical oxidation_Michael addition reaction. The possible mechanism of electrochemical oxidation_Michael addition reaction is presented.


Cathodic Indirect Electro-Oxidation——Organic Electro-Synthesis Dimethyl Sulfone, Deng-Ping Gu, Rui-Zhi Wang, Hong-Kun Zhang, Xue-Ying Zhang, Wei Li Feb 2000

Cathodic Indirect Electro-Oxidation——Organic Electro-Synthesis Dimethyl Sulfone, Deng-Ping Gu, Rui-Zhi Wang, Hong-Kun Zhang, Xue-Ying Zhang, Wei Li

Journal of Electrochemistry

A cathodic indirect electro_oxidation system was established for indirect electro_oxidize dimethyl sulfoxide to dimethyl sulfone with electro_reduction generated H 2O 2 catalyzed by the pertungstate/tungstate(WO 5 2- /WO 4 2- )redox mediator. Influences of current density,pH,temperature,and the current efficiencies etc. on the cathodic indirect electro_oxidation of dimethyl sulfone were investigated for determining optimum reaction conditions.The current efficiency reached more than 70%.Mother_liquid could be recycled to use without pollution.


Study Of Chlorination Of Nickel Ferrite By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic Jan 2000

Study Of Chlorination Of Nickel Ferrite By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic

Zeljko J Kamberovic

Thermodynamic analysis and experimental research of the chlorination of nickel ferrite (NiFe2O4) by gaseous chlorine in the presence of added C, BaS, S and NaCl in the temperature range from 300 to 900¾C are given in this paper. Nickel ferrite chlorination in the presence of BaS and CaCl2 was carried out in the temperature range from 750 to 950¾C. The presence of added C, BaS, S and NaCl intensifies the chlorination process of nickel ferrite by gaseous chlorine and reduces the temperature the reaction begins at from 700 to 300¾C. It is concluded that the process of nickel chlorination without …


Study Of Chlorination Of Nickel Silicate By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic Jan 2000

Study Of Chlorination Of Nickel Silicate By Gaseous Chlorine And Calcium Chloride In The Presence Of Active Additives, Zeljko J. Kamberovic

Zeljko J Kamberovic

The paper presents a thermodynamic analysis and experimental research on the kinetics of the chlorination of nickel silicate (2NiOÀSiO2) by gaseous chlorine and calcium chloride without additives and in the presence of added C, BaS, S and NaCl, to intensify the process. The influence of temperature in the range from 673 up to 1223 K for various chlorination times has been studied. Additives increases the chlorination rate. The kinetics of the process were determined by the analysis of dependence of the nickel chlorination rate on time and temperature. It was established that nickel chlorination without additives is a chemically-controlled reaction, …


Application Of Wavelets And Principal Component Analysis In Image Query And Mammography, Sol Neeman Ph.D. Jan 2000

Application Of Wavelets And Principal Component Analysis In Image Query And Mammography, Sol Neeman Ph.D.

Engineering Studies Faculty Publications and Creative Works

Breast cancer is currently one of the major causes of death for women in the U.S. Mammography is currently the most effective method for detection of breast cancer and early detection has proven to be an efficient tool to reduce the number of deaths. Mammography is the most demanding of all clinical imaging applications as it requires high contrast, high signal to noise ratio and resolution with minimal x-radiation. According to studies [36], 10% to 30% of women having breast cancer and undergoing mammography, have negative mammograms, i.e. are misdiagnosed. Furthermore, only 20%-40% of the women who undergo biopsy, have …


Textured Mos 2 Thin Films Obtained On Tungsten: Electrical Properties Of The W/Mos 2 Contact, E. Gourmelon, J. C. Bernède, J. Pouzet, S. Marsillac Jan 2000

Textured Mos 2 Thin Films Obtained On Tungsten: Electrical Properties Of The W/Mos 2 Contact, E. Gourmelon, J. C. Bernède, J. Pouzet, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Textured films of molybdenum disulfide have been obtained by solid state reaction between the constituents in thin films form when a (200) oriented tungsten sheet is used as substrate. The crystallites have their c axis perpendicular to the plane of the substrate. The annealing conditions are T=1073K and t=30 min. The films are stoichoimetric and p type. Such highly textured films are achieved without foreign atom addition (Ni, Co...). It appears, as shown by x-ray photoelectron spectroscopy, that a thin WS2 layer is present at the interface W/MoS2. The crystallization process is discussed by a …


Modeling The Effect Of Plasticizer On The Viscoelastic Response Of Crosslinked Polymers Using The Tube-Junction Model, P. P. Simon, Harry J. Ploehn Jan 2000

Modeling The Effect Of Plasticizer On The Viscoelastic Response Of Crosslinked Polymers Using The Tube-Junction Model, P. P. Simon, Harry J. Ploehn

Faculty Publications

Plasticizers modify the mechanical properties of polymericmaterials. The effects of plasticizers on glass transition temperatures can be most clearly observed in isochronal temperature sweep profiles of viscoelastic dynamic moduli. However, no simple mathematical models of plasticization are available to those who wish to design and employ plasticized materials in specific applications. We extend a phenomenological, molecular-level model (known as the tube–junction model) for crosslinked polymers to describe the effect of plasticizers on dynamic moduli. We show that the increase in free volume fraction due to the presence of the plasticizer can account for the shift in the glass transition in …