Engineering Commons^™

The Influence Of Cathode Ingredients In Zinc Chloride Type Battery On The Discharge Ability, Qi Shen, Biao Zhuang

Journal of Electrochemistry

The influence of cathodic powder ingredients in ZnCl₂ type heavy duty battery on the discharge ability has been studied, a suitable battery ingredients is founds.

Hydrogen Evolution Reaction On Nanocrystalline Co-Mo/Ni Composite-Coated Electrodes, Weizeng Yu, Jie Ma, Yiming Chu, Huizhe Zhu, Hongjie Wang, Shuncheng Liu

Journal of Electrochemistry

The electrochemical behaviours of the hydrogen evolution reaction (HER) at electrodes prepared by composite coating of nanocrytstalline Co-Mo alloy particles formed by ball milling on nickel base has been sludied by using sleady-state polarization and ac impedance techiu ques. The microstructure and the size of the nanocrystals of Co-Mo alloy and the morphology of the composite-coating surface of the electrodes are measured by XRD, TEM and SEM. Results show that the nanocrystalline Co-Mo alloys prepared by high energy ball milling has high electrocatalytic activity for HER. The electrocatalytic activity for the HER is enhanced and the energy of activation for …

Electrochemical Studies On Corroding Metallic Electrodes In Frequency Domain, Chunan Cao

Journal of Electrochemistry

The electrochemical studies on corroding metallic electrodes carried out in the State Key Laberatory for Corrosion and Protection are reviewed briefly: (1) General equations of faradaic admittance under potential-control condition were derived based on the stabillity conditions of steady processes. The faradaic admittance at mixed potential then was deduced based on these equations and the electrochemical impedance spectroscopy (EIS) at corrosion potentials in the solutions containing interface inhibitors was diseussed by application of the thecetical results obtained. (2) The spectral power density (SPD) curves for electrochemical noise (EN) during the initial stagu of pitting corrosion were observed for iron and …

Kinetic Behavior Of The Pt/Ysz Solid Electrolyte Interface Exposed To O2+He Mixture, Yi Jiang, Wenzhao Li, Lixin Cao, Jingwang Yan

Journal of Electrochemistry

Electrochemical behavior of the Pt/YSZ solid electrolyre interface has been investigated by cyclic voltammetry and linear potential sweep technique. It was found that the electrochemical adsorption of oxygen on the Pt surface follows the Temkin adsorption model. The amount of oxygen species increases logarithmically with time. Two oxygen species are electrochemically formed on the Pt surface. One is atomically adsorbed, the other probably subsurface oxygen or Pt oxide. The electrochemical reduction of adsorbed oxygen is kinetically irreverable. The cathodic peak potential is affected both by the potential sean rate and the amount of oxygen ahorbed on the surface. Kinetic parameters, …

An Indirect Electrochemical Oxidation Of Toluene─Catalytic Effects Of Ag(Ⅰ) On Mn(Ⅱ)/Mn(Ⅲ) Couple Transition At Pt Electrode, Zhonghua Wang, Yunan Qu, Xingguo Yan, Qngmin Hua, Guacai Chen, Zhongquan Wang

Journal of Electrochemistry

The Catalytic effects of Ag(Ⅰ) on toluene oxidation by Mn(Ⅲ) as well as the anodic generation of Mn(Ⅲ) were investigated. The rates of toluene oxidation were first order with respect to both Ag(Ⅰ) and Mn(Ⅲ). Ag(Ⅱ) formed on the surface of the platinum anode when Ag(Ⅰ) was present in the anolyte, which catalyic the Mn(Ⅱ) to Mn(Ⅲ) in solution.

Ftis Observation Of Twin Adsorbates Of Co On Rh Electrode In Acid Solution, Wenfeng Lin, Shigang Sun

Journal of Electrochemistry

Because of its great importance both in electrocatalysis and C1 chemistry applications, the adsorption of CO on metallic electrodes such as Pt, Pd, Au, Ag, RhF, etc. has been extensively studied by in situ infrared spectroscopy Since 1981. In all these studies only three types of CO adsorbates, i. e., linear (2090～2000 cm^-1), bridgrd (2000～1900 cm^-1) or multi-bonded (1900～1800 cm^-1) species, were identified. A different absorbate, twin CO on rhodium (Rh(CO)₂), does exist on the solid/gas interface of highly dispersed Rh or Rhn clusters on supports, this species originating a doublet at …

Preparation Techique Of Foamed Nickel By Electrodeposition, Xihua He, Ronghui Hu, Hanxi Yang, Zhengzhong Zuo

Journal of Electrochemistry

This paper describes the preparation technique and operation conditions for manufacturing foamed nickel by chemilcal pretreament, electrodeposition and heat treatment. The foamed nickel made in this method showed high porosity, uniformity and considerable strength and tenacity,applicable for various secondary battery electrodes.

Study Of The Calcium-Thionyl Chloride Cells, Baohong Zhang, Meng Chen, Yingdong Wang, Dongsheng Xu

Journal of Electrochemistry

The properties of CaCl₂ SEI covered on the ca electrode surface in thionyl chloride, the influence of various salts in thionyl chloride on the porformance of the Ca anode and carbon cathode, and the function of the additive CuCl₂ and CuBr₂ to cathode in the improvement of the cathode performance were studied by AC impedance, constant current discharge, and SEM. As a result, the Ca-SOCl₂ cell was able to discharge at 50 mA·cm^-2 and the capacity reached 17.5 mAh·cm^-2.

Research On Molten Carbnate Fuel Cell, Naichao Li, Baolian Yi, Lianying Kong, Enjun Zhang, Huaxin Lin, Tianxi Qu, Yingcai Cheng

Journal of Electrochemistry

Cold-roll-milling has been evaluated as a technique for preparing porous LiAlO₂ matrices for use as a molten carbonate fuel cell electrolyte matrix. This technique produces reliable electrolyte structures with the following characteristics and advantages: ease of handling, uniform thickness, using nontoxic inorganic solvents, controlled pore size distribution, and ability to be impregnated with the alkali carbonate without fracrure.

The Molren Carbnatod Fuel Cell (MCFC) was assembled from sintered Ni electrodes and LiAlO₂ electrolyte matrix, the electrode area is 28 cm², the effect of operating conditions on cell performance was tested, it was found that the cell …

The Electrochemical Behavior Of C60-Chemically Modified Poly(N-Vinylcarhzole)In 1 Mol/L Liclo4-Thf Solutions, Yu Chen, Zuen Huang, Ruifang Cai, Fupin Zhang

Journal of Electrochemistry

The electrochemical behavior of C₆₀-PNVC copolymer in 1 mol/L LiClO₄-THF solutions has been studied by cyclic voltammetry. The results demonstrated that there are considerable differences of electronic structure between PNVC (Poly (N-vinylcarbazole)) and C₆₀-PNVC copolymer, this being consistent with the ESR results and the oxidstion-reduction activarion of pure PNVC by C₆₀-chemical modification. In the potential region, 1.3V～-3.5V, five steps, 0. 90V/0.60V, 0.20V/0.00V, -1.05V/-1.30 V, -1.25V/-1.75 V, -2.00V/-2.50V, of oxidation/reduction proceases were indicated in the cyclic voltammetry for pure PNVC, whereas seven steps, 0.20V/0.20V, -0.30V/-0.50 V, -0. 60V/-0.60 V, -0.80V/-1.10 V, -1.95V/-2.10 V, …

Study On The Manufacture Of Pt/C Gas-Diffusion Electrodes, Yonglin Ma

Journal of Electrochemistry

The various methods of manufacturing gas-diffusion electrodes are reviewed and a new method of preparing the Pt/C electrocatalyst and the gas-diffusion electrodes is explored in this paper. The electrochemical performance of resulting electrodes in concentrated phosphoric acid for oxygen reduction at 150℃ are compared with the commercial electrode which purched from Giner Inc. (U. S. A). The results show that the performance of the Pt/C electrodes which manufactured by the method in this paper has been greatly improved. Therefor, a fuel cell using such electrodes has high industrial value.

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Building Services Engineering

No abstract provided.

Laboratory Growth Systems In Biofilm Research, Julian W. T. Wimpenny

Cells and Materials

The huge variety of ecosystems that we collectively refer to as "biofilm" is reflected by the numerous different systems available to grow them in the laboratory. The relationship between in situ systems, microcosms and laboratory models is defined and discussed. The first two represent holistic approaches designed to assess the structure and function of particular biofilms: the last is analytical and reductionist, aiming to isolate specific functions of biofilms in order to understand properties that can apply to biofilm in general. Properties of a model can be completely understood whilst this is unlikely with natural ecosystems because of the possibility …

Initial Biodeterioration Of Silicone Rubber By C. Albicans And C. Aropicalis Strains Isolated From Voice Prostheses, H. C. Van Der Mei, B. Van De Belt-Gritter, F. Dijk, H. J. Busscher

Cells and Materials

Silicone rubber voice prostheses m patients after total laryngectomy become rapidly colonized by a biofilm, consisting of yeasts and bacteria. An especially troublesome feature of these biofilms is the ingrowth into the silicone rubber by colonizing yeasts. Microcolonies of ingrowing yeasts have been frequently observed on explanted voice prostheses after 3-4 months use. Incubation of silicone rubber samples in a modified Robbins device with a culture of Candida tropicalis, isolated from a Groningen button voice prosthesis, while passing the yeasts through a cycle of feasts (7 days) and famine (also 7 days) demonstrated, by electron microscopy, the onset of the …

Effects Of Solidification Conditions And Heat Treatment On The Microstructure And Vickers Hardness Of Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, Stanley G. Vermilyea, Efstratios Papazoglou, John C. Mitchell, Alan B. Carr

Cells and Materials

Two representative Pd-Cu-Ga dental alloys, one with a dendritic as-cast microstructure containing a eutectic interdendritic constituent and the other with an equiaxed fine-grained as-cast microstructure containing a near-surface eutectic constituent, have been subjected to rapid quenching following casting, in addition to the conventional bench cooling recommended by the manufacturers. The quenched alloys were subsequently heat treated at temperatures of 1200°, 1500° and 1800 op that span the range of the firing cycles for dental porcelain. Scanning electron microscopic examination showed that the lamellar eutectic constituents normally present in the microstructures of the as-cast and bench-cooled alloys persisted when the alloys …

Gap Junctional Intercellular Communication In Bone, Henry J. Donahue, Monique A. Vander Molen, Clare E. Yellowley, Zhongyong Li

Cells and Materials

Gap junctional intercellular communication has been demonstrated in bone cells and may contribute to the mechanism by which osteoblasts integrate and amplify extracellular signals, both chemical (hormonal) and biophysical (electrical and mechanical). Connexin 43 (Cx43) is the predominant gap junction protein expressed by bone cells. Experiments with osteoblastic cells in which Cx43 expression was diminished by antisense transfection demonstrate that cell-to-cell coupling in osteoblastic ROS 17/2.8 cells is via gap junctions composed of Cx43. Cellular networks of these coupling deficient clones are dramatically less responsive to parathyroid hormone (PTH) suggesting that coupling contributes to hormonal responsiveness. Furthermore, PTH per se …

Fabrication Of A Three-Phase Double Polysilicon Charge Coupled Devices, Sarah Cohen

Journal of the Microelectronic Engineering Conference

Charge-coupled devices were fabricated using the existing seven level mask design (Scott Kipperman). Previous attempts at RIT (Scott Kipperman, Michael McGranahan) to fabricate working CCD's have not been successful, perhaps due to time constraints and misprocessed lots. Devices were completed using the current CCD process, while overcoming previous process problems. Results include testing of poly1 and poly2 transistors, and an attempt to test a one-dimensional 8-pixel array electrically. Equivalent capacitors were built, the threshold voltages obtained were 6.84V and 6.62V, respectively. The 8-pixel array was shown to be light sensitive, and conduct current as all three phases were pulsed high. …

Calibration Of Process And Electrical Models For Rit Vertical Npn Bipolar Junction Transistors, Lena Zavyalova

Journal of the Microelectronic Engineering Conference

Presented study is based on the need in 2D process and device simulations providing a good estimation of in-line process and electrical parameters for RIT vertical NPN bipolar junction transistors. These involve process and electrical modeling adjustments in order to reproduce vertical dopant profiles and show an appropriate electrical behavior of simulated BJTs Technology Modeling Associates (TMA) software has been implemented to facilitate this task. Theoretical and experimental verification efforts have been performed to examine the validity of the simulation results, and good agreement has been obtained.

A Practical Porous Silicon Device Structure For Increased Electroluminescent Efficiency, D Cardarelli

Journal of the Microelectronic Engineering Conference

This work reports on the results of two innovative designs for efficient silicon-based light emitting devices(LEDs). The two devices demonstrated improvement on the extraction efficiency of photons produced by electroluminescent porous silicon. With the previous structures, the produced luminescence was collected from the surface of the devices through the uses a redesigned top contact along with an etch into the active region of the device. The second type used an edge emitting arrangement. The new surface emitting device showed visible luminescence that was easily seen in a dim ambient. the edge emitting structure exhibited an increase in intensity of between …

Development Of A Polygate Pmos Process Compatible With Micromechanical Sensor Fabrication, Earl P. Schenck

Journal of the Microelectronic Engineering Conference

The objective for this study is to develop a device fabrication process that is compatible with the fabrication process that is compatible with the fabrication of on-chip micromachine sensors. It is desirable for the devices to be easily fabricated and to incorporate the least number of additional fabrication steps in the existing procedure of the micromechanical pressure sensor.

The polysilicon gate PMOS technology was merged into the fabrication of the capacitive pressure sensor with only two additional lithography steps that utilized the same mask. The primary results showed working PMOS transistors with a threshold voltage of -1 V, inverters with …

Formation Of Sidewall Spacers And Titanium Salicide For Rit's Sub-Micron Cmos, S K. Bhaskaran

Journal of the Microelectronic Engineering Conference

Low Temperature Oxide (LTO) sidewall spacers have been successfully fabricated using etchback an technique. The process for forming these features was optimised for repeatibility for RIT's sub-micron CMOS. In addition, a reliable process for forming low resistive self aligning titanium silicide was also developed using these sidewall spacers.

Chemical-Mechanical Polishing Of Copper With A Low K Polymer Interlevel Dielectric, Thomas L. Brown

Journal of the Microelectronic Engineering Conference

Chemical-mechanical polishing (CMP) of copper with a low dielectric constant polymer as interlevel dielectrics (ILD) has been demonstrated as a viable patterning approach for copper interconnect structures. This paper presents a study of the mechanisms involved in copper CMP when used with a low k ILD. A two-step model of copper CMP involves the mechanical abrasion of the copper surface followed by removal of the abraded material from the vicinity of the surface and has been optimized after rigorous CMP experiments with alternative slurries.

Development Of Bonding And Etchback Silicon On Insulator Wafers, Bobby Mozumder

Journal of the Microelectronic Engineering Conference

Bonding and Etchback Silicon on Insulator wafers were successfully developed at the Rochester Institute of Technology's Microelectronics facilities. [100] and [111] wafer pairs were successfully bonded using SOG and Thermal Oxides and etched back using times KOH etch. The results were successfully bonded wafer with a large Silicon layer.

Improvement In Polysilicon Etch Process For The Rit Factory, Thomas F. Flynn Jr

Journal of the Microelectronic Engineering Conference

Investigations of the polysilicon etch process utilized by the RIT factory for CMOS fabrication were conducted. The RIT factory process utilizes a dry polysilicon etch process that employs SF₆ and o₂ chemistry, with flow rates of 42 sccm and 7.5 sccm, at 400 mTorr pressure and 40 watts of RF power in a GEC PlasmaCell. This process was found to suffer from uniformity problems. Stdies were done to attempt to improve the etch uniformity, by varying the chamber pressure. A significant improvement in the uniformity was achieved for a much lower chamber pressure of 175 mTorr under the …

Rapid Thermal Oxidation Process For 100a Si02, Mark Maslow

Journal of the Microelectronic Engineering Conference

An examination of RIT's AG Associates Heatpulse 410 rapid thermal processing system has been conducted to look at the possibilities of an in-control, high quality, 100A oxide growth process. Some of the complications involved with modifying the existing system to have the oxidation capability are discussed. Growth rate curves for various temperatures have been developed through a designed experiment. MOS capacitors have been fabricated using an optimized 100A recipe to characterize the electrical properties of the oxide.

The process for growing 100A oxides was tested for uniformity, repeatability, and oxide quality. Ellipsometry mapping of the wafers showed a 5.8% uniformity …

Effects Of Variations In Rca Clean On Breakdown Characteristics Of Thin Gate Oxides, Bryan Kasprowicz

Journal of the Microelectronic Engineering Conference

Several variations on the order of the RCA clean have been investigated for their effects on oxide charges and interface trap density of thin gate oxides (200 - 250A). Surface Charge Analysis (SCA) will be employed to evaluate charges and traps immediately after oxide growth. Capacitors with aluminum gate were then fabricated to determine the dielectric field breakdown testing on an HP4145 parametric analyzer, the total oxide charge and interface trap density have been obtained from C-V testing using a Keithley simultaneous high frequency / low frequency system.

Surface Charge Analysis (Sca) Of 300 Angstrom Thermally Grown Oxides, Briand D. Handel

Journal of the Microelectronic Engineering Conference

As the microelectronic industry progresses toward smaller devices, a decrease in the thickness of gate oxides accompanies them. High quality cannot be sacrificed as a result of this shrinkage. It is believed that oxide quality can be related to oxide charge density. Total oxide charge is related to a shift in Vt for transistors and believed to be related to oxide breakdown strength.

A surface charge analyzer on loan from the SemiTest Corp. was used to quantify oxide charge densities after thermal oxidation of 300 A oxides under various processing conditions. Variations to the base process included the temperature at …

Role Of Hydrogen At The Si/Sio2 Interface On Mos Cv Characteristics, Rahul Sachdev

Journal of the Microelectronic Engineering Conference

In this study an attempt has been made to investigate the effect of intentional doping of hydrogen near the Si/SiO₂ interface by ion implantation. MOS capacitors were fabricated with a composite stacked dielectric of thermally grown SiO^₂ and LPCVD nitride with and without H-implantation. Poly gate capacitors fabricated on both N and P type silicon wafers showed no significant change with hydrogen implant. Effect of hydrogen was distinct in aluminum gate structures.

Inorganic Arc For Use In Microlithography, David J. Stern

Journal of the Microelectronic Engineering Conference

In this study silicon nitride has been seen to be an effective anti-reflective coating for use at wavelengths from 190 to 436mm. The report discusses effects of the film such as index of refraction, extinction coefficient, thickness, and stoichiometric composition for the application of ARC in microlithography.

Investigation Of New Positive And Negative Electron Beam Resists For Microlithography, Huy M. Cao

Journal of the Microelectronic Engineering Conference

The primary objective of this investigation was to obtain maximum electron beam resist contrast (gamma), maximum sensitivity, minimum thickness loss, and maximum plasma etch resistance for 10 KeV electron beam exposure process. This is to be achieved while maintaining a robust design. This study also compares the etch resistivity and etch rate of different electron beam resist materials to O2, Cl2, and SF6 containing plasma conditions. Measurements of the resist thickness loss yield the results of resist sensitivity and gamma for various development conditions