Engineering Commons^™

Time-Resolved Electron Spin Resonance Spectroscopy For In-Situ Studies Of Electrochemical Systems, Lin Zhuang, Juntao Lu

Journal of Electrochemistry

No abstract provided.

Surface Raman Spectra Obtained From Various Electrodeposited Transidon Metals, Jingsong Gao, Bin Ren, Qunjian Huang, Zhongqun Tian

Journal of Electrochemistry

Good quality potential-dependent surface Raman spectra of pyridine were obtained for the first time from a series of transition metals, e. g., Fe, Co, Ni, Ru, Rh, Pd and Pt, which were electrodeposited on non-SERS-active substrates. The influences of the applied potential and the nature of metal on the adsorption behaviors were discussed briefly. This result illustrates that Raman spectroscopy is becoming a more general and powerful tool to study various electrochemical interfaces.

Electrodeposition Of Cu-Co Multilayer Thin Films, Jiangyun Xue, Jixun Wu, Dejun Yang

Journal of Electrochemistry

A method has been developed to produce Cu-Co Multilayer from a single electrolyte by electrodeposition. The effects of the concentration of copper ions, current density and the speed of rotation were investigated, and the Cu-Co electrodeposition films were analysed by TEM, AES and X-ray diffraction. The results indicated that the film was alternating pure copper and coppercobalt alloy layers. If the content of copper in cobalt layer is to be small, the concentration of its ions in solution must be small and the rotation speed must be low.

Study On The Ionic Conductivity Of Comb Polymer Electrolytes, Liming Ding

Journal of Electrochemistry

A comb polymer (CP350) with oligo-oxyethylene side chains was prepared from methyl vinyl ether/maleic anhydride copolymer.The ionic conductivity of CP350/LiAsF₆ and CP350/LiAsF₆ complexes was studied as a function of temperature and [Li]/[EO] ratios. A equivalent circuit was given to interpret complex impedance spectra. At 25 ℃, the ionic conductivity maxima of the two systems are 1.38×10^-4, 8.32×10^-5 S/cm respectively. The appearance of the conductivity maxima has been interpreted as being due to the effect of microviscosity on ion transport. lonic conduction displays non-Arrhenius behaviour. The temperature dependence of ionic conductivity was attributed mainly to the …

Electrochemical Studies On Chemical Polishing Of Copper, Keping Han, Jingli Fang

Journal of Electrochemistry

Changes in specular reflectivity,weight loss,surface topograph and potential with time and current-potential curves during chemical polishing were determined. The results showed that chemical polishing was composed of the etching, polishing and pitting stage. The passivating film theory also applied to the chemical polishing.

Study On The Growth Process Of Lead Dioxide On Lead-Antimony Electrodes By Impedance Tracing Method, Guolin Wei, Hongxin Yang, Jiarong Wang

Journal of Electrochemistry

The growth process of PbO₂ formed by the oxidation of PbSO₄ in the anodic film on lead-(1,3,5,7)wt% antimony electrodes was investigated with impedance tracing method of single frequency and the current-time transient method. The influence of antimony on this process was studied.The simulation curves obtained for capacity-time transients fit the experimental results very well. It has been shown that the mentioned growth process is a two-dimentional instantaneous nucleation and growth process. Antimony will inhibit the growth of PbO₂ nucleus but enhance its nucleation.

The Relationship Between Ionic Conductivity And The Structure Of The New Polymer Electrolytes, Hongze Liang, Yongxiang Song, Liming Ding, Yuchen Qi, Lixia Li, Xiabin Jing, Fusong Wang

Journal of Electrochemistry

Ionic conductivity of polymer-eutectic composed of lithium perchlorate and lithium nitrate has been studied. The effects of eutectic and polymers upon the conductivities have been discussed.The lonic conductivity depends on the eutectic properties as well as the treatment method of samples.

Improvement Of The Anti-Interference Characteristics Of God Electrode By Using The Powder Microelectrode Technique, Chen Jian, Chuansin Cha

Journal of Electrochemistry

The electrochemical behavior of ascorbic acid(AA), uric acid(UA), L-cystein(L-Cys) and acetaminophen (APAP), i.e. The main interference to the GOD electrode, were studied at the Pt,GC and powder microelectrode. Experimental results indicated that, due to the electrochemical activity of these interference, it is difficult to eliminate their interference effects by manipulation of electrode materials or working potential of the GOD electrode. However, it was found that the limiting curtents at the KB electrode are mainly controlled by mass transfer in liquid phase, so it is only related to the geometer size of the electrode, not its real surface area. Therefore, it …

A Study On Electrochemical Oxidation Of Reduced Nicotinamide Coenzyme Nadh In Organic Media, Fangzu Yang, Huihuang Wu, Shukai Xu, Shaomin Zhou

Journal of Electrochemistry

The behaviour of electrochemical oxidation of the reduced nicotinamide coenzyme NADH on glassy carbon was studied and some kinetic parameters were measured by means of voltammometry in the N-dimethylformamide (DMF) and 1,4-dioxane media respectively. The eletrochemical oxidation of NADH shows completely irriversable both in the two solvents,and the diagnostic experiments support that the process involves a fast chemical step.The oxidation rate and the diffusion coefficient of NADH in DMP are smaller than those in 1,4-dioxane, but the response current is more stable in DMF. The experimental results are discussed by solvent effects.

Studies On The Charge And Discharge Reaction Of Li/Lini0.3Co0.7O2 Battery, Fupjng Zhang

Journal of Electrochemistry

The charge and discharge reaction of Li/LiNi_0.3Co_0.7O₂ battery have been studied by using CV,CT,XRD and GCP. It is shown that the discharge capacity of the cell reaches 120-140 mA·h·g^-1 in the 4.30-3.00 V in 1 mol/L LiClO₄/PC electrolyte system. The discharge mechanism involve a two-step Li⁺ intercalation reaction. The thermodynamic data such as ΔG,ΔS, ΔH, of the reaction are given. Furthermore, the changes of the D or σ_i of Li⁺ with its composition have been discussed.

A Study On Solid Polymer Electrolyte Fuel Cell, Hongfeng Xu, Ming Han, Baolian Yi, Xinge Zhang, Shanhai Ge

Journal of Electrochemistry

Solid polymer electrolyte fuel cell (SPEFC) show promise of a high level of performance in the present fuel cell. In this paper, we report the method of SPEFC electrode preparation,and the effects of temperature, pressure and gas flow rate on the performance.

Electrochemical Study Of The Corrosion Behavior Of Coalesced Copper And Sw-206 Stainless Steel In The Acetic-Acid Solution, Rongzong Hu, Changjian Lin, Jianguang Tan, Zhanmei Sun, Xueqin Wu, Biao Wang

Journal of Electrochemistry

In order to provide a theoretic and experimental consideration for the material selection and anit-corrosion in the petrochemical industries the corrosion behavior of coalesced copper and sw-206 stainless steel in the acetic acid solution was studied by electrochemical impedance spectroscopy and polarization techniques. The effects of the temperature, acetic acid concentration and solubilized oxygen in the acetic acid solution on the corrosion process of this two metals were analyzed. It was found that these effects obviously accelerate corrosion process for the coalesced copper, but no apparent influnce for the sw-206 stainless steel.In the the acetic acid solution, containing water and …

An Esr Study Of Free Radicals In Electroreduction Process Of Allyl Alcohol, Jindong Zhang, Yafei Kuang, Shukun Huang, Naixian Xie, Fengzhen Wang, Dewen Chen

Journal of Electrochemistry

Electrochemical-ESR technique with spin trap phenyl-t-butyl nitrone(PBN)was used to study the intermediates of electroreduction of allyl alcohol at platinized platinum electrode in acidic alcohol-aqua solution. Hydrogen and allyl group and(or)propyl group radicals were identified by a hyperfine spectrum of the radical adducts, and that provided a direct evidence for the presence of these radicals in the electroreduction of allyl alcohol.

Real-Time Range Image Segmentation Using Adaptive Kernels And Kalman Filtering, Fred W. Depiero, Mohan M. Trivedi

Electrical Engineering

Segmentation is a fundamental process affecting the overall quality and utility of a machine vision system. Range Profile Tracking (RPT) is a systematic approach for stable, accurate and high speed segmentation of range images that is based on Kalman filtering. Tests of RPT have produced stable decompositions of second order surfaces bounded by jump and crease discontinuities, having a volumetric error of a few percent, in under 6 sec. for a wide variety of conditions. Results from over 900 tests on synthetic scenes and 150 real range images are presented.

Simple Rail-To-Rail Constant-Transconductance Input Stage Operating In Strong Inversion, Vladimir I. Prodanov, Michael M. Green

Electrical Engineering

A CMOS op-amp input and gain stage suitable for low voltage operation are introduced. The input stage operates in strong inversion and has common-mode range beyond rail-to-rail. It uses two complementary differential pairs connected in parallel. The common-mode dependent current biasing employs only four transistors, does not require additional voltage references, current switches and/or current mirrors and does not increase the minimum required supply voltage. The variation of the net transconductance is approximately 15% over the entire common-mode range. The gain-stage has constant output resistance. In addition it reduces the variation of the net transconductance due to variations in μn/μp …

Design And Implementation Of A Model For Authoring And Presenting Interactive Multimedia Documents, Vibha Mukul Nayyar

Dissertations and Theses

Multimedia technology enables direct manipulation of multiple media such as text, image, audio, and video, all integrated into one entity - the multimedia document. Interactive multimedia documents integrate text, images and continuous media such as audio and video, treat them as objects to be presented for a certain duration, and allow users to interact with the presentation. Authoring and presenting interactive multimedia documents imposes new requirements on document representation. We designed the interactive timeline model (ITM) for authoring and presenting interactive multimedia documents. We implemented the model and created a playback tool using the scripting language Tcl.

ITM uses an …

Are Energy Savings Due To Ceiling Fans Just Hot Air?, Florida Solar Energy Center, Patrick James

FSEC Energy Research Center®

Human comfort studies have shown that people prefer higher temperatures when they are subjected to a breeze. Ceiling fans are often used to create air motion in residences. Simulation studies (including one given in this paper) have demonstrated that in Florida, using ceiling fans combined with raising a home's temperature 2° F will generate about a 14% net savings in annual cooling energy use (subtracting out the ceiling fan energy and accounting for internally released heat). This savings drops to 2.6% with a 1° F increase in set point and to a negative 3.7% savings with only a 0.5° F …

Recent Developments In Extrusion Freeform Fabrication (Eff) Utilizing Non-Aqueous Gel Casting Formulations, Greg Hilmas, John L. Lombardi, Robert A. Hoffman, Kevin Stuffle

Materials Science and Engineering Faculty Research & Creative Works

Extrusion Freeform Fabrication (EFF) was shown to be an extremely versatile method for fabricating Functionally Graded Materials (FGMs) The approach is inexpensive and potentially feasible for grading between any thermodynamically compatible ceramic-metal, ceramic-ceramic, or metal-metal material combination. Several material systems were investigated in this study including alumina-304 stainless steel, zirconia-304 stainless steel, alumina-Inconel 625, zirconiaInconel625, alumina-nickel aluminide, zirconia-nickel aluminide, titanium carbide-InconeI625, titanium diboride-nickel aluminide, and tungsten carbide-nickel aluminide. A controlled gradient was demonstrated between the end members for all of the above compositions. The FGMs were hot pressed to achieve near theoretical densities, providing flexural strengths as high as 1000 …

Fabrication Of Double Side Fully Metallized Plated Thru-Holes, In Polymer Structures, Without Seeding Or Photoprocess, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

The present invention is directed to a process of a method for the full metallization of thru-holes in a polymer structure comprising the steps of applying a film-forming amount of a conductive polymer-metal composite paste to a metal cathode; bonding a patterned polymer structure to said paste; subjecting said polymer structure to an electrolytic plating bath for a time sufficient to fully metallize thru-hole surfaces in said patterned polymer structure and removing the structure from the cathode assembly. The fully metallized thru-hole polymer structure can then be cleaned and polished to produce a finished product.

Proposal For Renovation Of 1920 Tractor Test Lab Into Museum, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Bids for Renovating Roof State Fair Display Further Funding for Renovation

Daylight Dimming Systems: Studies In Energy Savings And Efficiency, Florida Solar Energy Center, Lynn Schrum

FSEC Energy Research Center®

Three studies were conducted at Florida Solar Energy Center (FSEC) to study the lighting energy savings of daylight dimming systems. The Daylighting Test Facility (DTF) was used to study daylight dimming systems and how aperture orientation and blinds affect performance. The energy consumption was compared in two pairs of offices for all four window orientations: north, south, east and west. One office in each pair had blinds in a fixed position (down and open) and the other office had no blinds. The study showed that the energy savings ranged from 24% to 51% depending on the orientation and blinds.

The …

Direct Chip Attachment (Dca) With Electrically Conductive Adhesives, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

A simple process for card assembly by Direct Chip Attachment (DCA) uses electrically conductive adhesives. Two methods create the same intermediate wafer product with a layer of insulative thermoplastic and conductive thermoplastic bumps. After sawing or dicing the wafer to form the chips, the chips are adhered to chip carriers with conductive pads which match the conductive thermoplastic bumps, using heat and pressure. Chips may be easily removed and replaced using heat.

Ccfss Technical Bulletin August 1996, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Acuta Enews August 1996, Vol. 25, No. 8

ACUTA Newsletters

In This Issue

Silver Anniversary Celebration 25 Years of Excellence

President's Message

Chicago Presentations Inspire, Inform, and Entertain

Executive Director

DC at a Glance

Record Number of Exhibitors in Chicago

From ACUTA Headquarters

A Comparison Of Traffic Models: Part 1, Framework, Hong Lo, Wei-Hua Lin, Lawrence Liao, Elbert Chang, Jacob Tsao

Faculty Publications

This report defines a framework for comparing dynamic traffic models. It emphasizes four dimensions: functionality, traffic dynamics, route choice dy namics, and overall network performance. The first dimension compares the models through a check-list of model functions. Regarding the last three comparison dimensions, a total of five networks and twelve scenarios are defined. These test scenarios are designed to accentuate model properties and differences. Also included in the report are a list of performance measures for comparison purpose, and a discussion of the interpretation of results.

Dynamic Traffic Assignment For Automated Highway Systems: A Two-Lane Highway With Speed Constancy, H.-S. Jacob Tsao

Faculty Publications

Dynamic traffic assignment through analytical modeling and optimization has been widely accepted by the IVHS R&D community as a promising traffic control tool for understanding and relieving traffic congestion on conventional highways and city streets. Due to the completely controlled nature of AHS traffic, dynamic assignment of AHS traffic is even more promising. One added dimension of complexity associated with AHS dynamic traffic assignment is lane assignment. Lane changes, for fully utilizing AHS capacity or for exiting, incur disturbances to and hence reduction of longitudinal flow. Intelligent lane assignment is necessary to ensure a high rate of successful exiting, to …

Structural Behavior Of Circular Holes In Web Elements Of Cold-Formed Steel Flexural Members Subjected To Web Crippling For End-One-Flange Loading, Craig Uphoff, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

I. INTRODUCTION A. GENERAL An environmental concern regarding the use of wood being an appropriate construction material has become a contemporary issue. The depletion of forests, caused not only by the building construction industry, but also by natural disasters such as forest fires, has raised many questions about the conservation of the environment. Trees are being replanted in an effort to make up for the loss, but trees take many years to mature. Therefore, in an attempt to improve the environment and the feasibility of building construction, alternative materials for residential construction are being investigated. One material that is being …

Measured Field Performance And Energy Savings Of Occupancy Sensors: Three Case Studies, Florida Solar Energy Center, David Floyd

FSEC Energy Research Center®

Occupancy sensors have the potential to significantly reduce energy use by switching off electrical loads when a normally occupied area is vacated. While occupancy sensors can be used to control a variety of load types, their most popular use has been to control lighting in commercial buildings. Manufacturers claim savings of 15% to 85%, although there is little published research to support the magnitude or timing of reductions. Energy savings and performance are directly related to the total wattage of the load being controlled, effectiveness of the previous control method, occupancy patterns within the space and proper sensor commissioning. In …

An Investigation Of The Relationships Between The Angle Of Mental Rotation Required For Spatial Orientation, Response Times, And Accuracy, Ronald D. Archer

Master's Theses - Daytona Beach

The purpose of this study is to investigate the relationship between the angles of mental rotation when attempting to spatially orientate and the resulting response times and levels of accuracy. By means of a computer program, participants were presented with 64 mental rotational trials. The mental rotational trials consisted of a triangle placed in the center of the screen with a standard stick symbol of an aircraft appearing at various headings and orientations around the triangle. The participants were required to imagine themselves inside the flight deck of the aircraft, and then respond as quickly and accurately as possible to …

Effect Of Unbalance On Power System Components In The Presence Of Harmonics, Jessica Williams

All Theses

No abstract provided.