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Analysis Of A Lithium/Thionyl Chloride Battery Under Moderate-Rate Discharge, Mukul Jain, Ganesan Nagasubramanian, Rudolph G. Jungst, John W. Weidner Jan 1999

Analysis Of A Lithium/Thionyl Chloride Battery Under Moderate-Rate Discharge, Mukul Jain, Ganesan Nagasubramanian, Rudolph G. Jungst, John W. Weidner

Faculty Publications

A one-dimensional mathematical model of a spirally wound lithium/thionyl chloride primary battery is developed and used for parameter estimation and design studies. The model formulation is based on the fundamental conservation laws using porous electrode theory and concentrated solution theory. The model is used to estimate the transference number, the diffusion coefficient, and the kinetic parameters for the reactions at the anode and the cathode as a function of temperature. These parameters are obtained by fitting the simulated capacity and average cell voltage to experimental data over a wide range of temperatures (–55 to 49°C) and discharge loads (10-250 ). …

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Determination Of The Lithium Ion Diffusion Coefficient In Graphite, Ping Yu, Branko N. Popov, James A. Ritter, Ralph E. White Jan 1999

Determination Of The Lithium Ion Diffusion Coefficient In Graphite, Ping Yu, Branko N. Popov, James A. Ritter, Ralph E. White

Faculty Publications

A complex impedance model for spherical particles was used to determine the lithium ion diffusion coefficient in graphite as a function of the state of charge (SOC) and temperature. The values obtained range from of 1.12 × 10–10 to 6.51 × 10–11 cm2/s at 25°C for 0 and 30% SOC, respectively, and for 0% SOC, the value at 55°C was 1.35 × 10–10 cm2/s. The conventional potentiostatic intermittent titration technique (PITT) and Warburg impedance approaches were also evaluated, and the advantages and disadvantages of these techniques were exposed

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Historical Essays On Meteorology, 1919-1995, Theodore S. Feldman Jan 1999

Historical Essays On Meteorology, 1919-1995, Theodore S. Feldman

Faculty Publications

No abstract provided.

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Preparation Of Mesoporous Tin Oxide For Electrochemical Applications, Fanglin Chen, Meilin Liu Jan 1999

Preparation Of Mesoporous Tin Oxide For Electrochemical Applications, Fanglin Chen, Meilin Liu

Faculty Publications

Mesoporous tin oxide stable up to 500 °C has been prepared for the first time using both cationic and neutral surfactants.

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Exploiting Expertise Through Knowledge Networks, Michael N. Huhns, Larry M. Stevens Jan 1999

Exploiting Expertise Through Knowledge Networks, Michael N. Huhns, Larry M. Stevens

Faculty Publications

The paper discusses the necessary capabilities of knowledge networks: categorizing (the ability to classify Web pages and other unstructured data automatically); hyperlinking (the ability to add to each item of information appropriate pointers to other relevant items of information); alerting (the automatic notification of users and agents to new information that might be of interest to them); and profiling (the construction of models of users and agents to describe their interests and expertise).

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Negotiating For Goods And Services, Michael N. Huhns, Anuj K. Malhotra Jan 1999

Negotiating For Goods And Services, Michael N. Huhns, Anuj K. Malhotra

Faculty Publications

Can a negotiation protocol be both fair and “envy-free” when more than two agents are involved? The authors consider how envy-free apportioning is more difficult than fair apportioning, but both can help to manage critical resources. They discuss an envy-free protocol and agent-based Web auctions.

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Benevolent Agents, Michael N. Huhns, Abdulla Mohamed Jan 1999

Benevolent Agents, Michael N. Huhns, Abdulla Mohamed

Faculty Publications

Some agents roaming the Web these days are benevolent-for example, they may clean up stalled or failed database transactions, or share query results that may have cost substantial resources to acquire and might consume more to share. The Agent Behavior Testbed is a tool for studying the economics of agent altruism. As more agents hit the Internet, benevolence and cooperation will help with overall efficiency and productivity. The paper discusses benevolent agents on the Web.

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Networking Embedded Agents, Michael N. Huhns Jan 1999

Networking Embedded Agents, Michael N. Huhns

Faculty Publications

Most of us will soon be managing an intranet in our homes, though we might not realize it. We might also be surprised at the devices that will be networked together. Just about every electrical device now contains one or more microprocessors. Designers typically find this a cost-effective way to provide device functionality, even when much of a processor's power is unnecessary or unused. For example, my coffee maker contains a processor, even though the appliance needn't be very smart and wastes most of its CPU cycles. Nevertheless, it is cheaper to include a general-purpose microprocessor than to incorporate custom …

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Ecological Legacies: Impacts On Ecosystems Of The Mcmurdo Dry Valleys, Daryl L. Moorhead, Peter T. Doran, Andrew G. Fountain, W. Berry Lyons, Diane M. Mcknight, John C. Priscu, Ross A. Virginia, Diana H. Wall Jan 1999

Ecological Legacies: Impacts On Ecosystems Of The Mcmurdo Dry Valleys, Daryl L. Moorhead, Peter T. Doran, Andrew G. Fountain, W. Berry Lyons, Diane M. Mcknight, John C. Priscu, Ross A. Virginia, Diana H. Wall

Faculty Publications

No abstract provided.

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Physical Controls On The Taylor Valley Ecosystem, Antarctica, Andrew G. Fountain, W. Berry Lyons, Melody B. Burkins, Gayle L. Dana, Peter T. Doran, Karen J. Lewis, Diane M. Mcknight, Daryl L. Moorhead, Andrew N. Parsons, John C. Priscu, Diana H. Wall, Robert A. Wharton, Ross A. Virginia Jan 1999

Physical Controls On The Taylor Valley Ecosystem, Antarctica, Andrew G. Fountain, W. Berry Lyons, Melody B. Burkins, Gayle L. Dana, Peter T. Doran, Karen J. Lewis, Diane M. Mcknight, Daryl L. Moorhead, Andrew N. Parsons, John C. Priscu, Diana H. Wall, Robert A. Wharton, Ross A. Virginia

Faculty Publications

No abstract provided.

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I/O-Conscious Tiling For Disk-Resident Data Sets, Mahmut Kandemir, Alok Choudhary, J. Ramanujam Jan 1999

I/O-Conscious Tiling For Disk-Resident Data Sets, Mahmut Kandemir, Alok Choudhary, J. Ramanujam

Faculty Publications

This paper describes a tiling technique that can be used by application programmers and optimizing compilers to obtain I/O-efficient versions of regular scientific loop nests. Due to the particular characteristics of I/O operations, straightforward extension of the traditional tiling method to I/O-intensive programs may result in poor I/O performance. Therefore, the technique proposed in this paper customizes iteration space tiling for high I/O performance. The generated code results in huge savings in the number of I/O calls as well as the data volume transferred between the disk subsystem and main memory. © Springer-Verlag Berlin Heidelberg 1999.

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A Matrix-Based Approach To Global Locality Optimization, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Prith Banerjee Jan 1999

A Matrix-Based Approach To Global Locality Optimization, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Prith Banerjee

Faculty Publications

Global locality optimization is a technique for improving the cache performance of a sequence of loop nests through a combination of loop and data layout transformations. Pure loop transformations are restricted by data dependencies and may not be very successful in optimizing imperfectly nested loops and explicitly parallelized programs. Although pure data transformations are not constrained by data dependencies, the impact of a data transformation on an array might be program-wide; that is, it can affect all the references to that array in all the loop nests. Therefore, in this paper we argue for an integrated approach that employs both …

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A Global Communication Optimization Technique Based On Data-Flow Analysis And Linear Algebra, M. Kandemir, P. Banerjee, A. Choudhary, J. Ramanujam, N. Shenoy Jan 1999

A Global Communication Optimization Technique Based On Data-Flow Analysis And Linear Algebra, M. Kandemir, P. Banerjee, A. Choudhary, J. Ramanujam, N. Shenoy

Faculty Publications

Reducing communication overhead is extremely important in distributed-memory message-passing architectures. In this article, we present a technique to improve communication that considers data access patterns of the entire program. Our approach is based on a combination of traditional data-flow analysis and a linear algebra framework, and it works on structured programs with conditional statements and nested loops but without arbitrary goto statements. The distinctive features of the solution are the accuracy in keeping communication set information, support for general alignments and distributions including block-cyclic distributions, and the ability to simulate some of the previous approaches with suitable modifications. We also …

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Personal Ontologies, Michael N. Huhns, Larry M. Stevens Jan 1999

Personal Ontologies, Michael N. Huhns, Larry M. Stevens

Faculty Publications

Corporations can suffer from too much information, and it is often inaccessible, inconsistent, and incomprehensible. The corporate solution entails knowledge management techniques and data warehouses. The paper discusses the use of the personal ontology. The promising approach is an organization scheme based on a model of an office and its information, an ontology, coupled with the proper tools for using it.

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Environmental Sustainability And Environmental Justice At The International Level: Traces Of Tension And Traces Of Synergy, Donald Thomas Hornstein Jan 1999

Environmental Sustainability And Environmental Justice At The International Level: Traces Of Tension And Traces Of Synergy, Donald Thomas Hornstein

Faculty Publications

No abstract provided.

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Dam Nation: A Geographic Census Of American Dams And Their Large-Scale Hydrologic Impacts, William L. Graf Jan 1999

Dam Nation: A Geographic Census Of American Dams And Their Large-Scale Hydrologic Impacts, William L. Graf

Faculty Publications

Newly available data indicate that darns fragment the fluvial system of the continental United States and that their impact on river discharge is several times greater than impacts deemed likely as a result of global climate change. The 75,000 dams in the continental United States are capable of storing a volume of water almost equaling one year's mean runoff, but there is considerable geographic variation in potential surface water impacts. In some western mountain and plains regions, darns can store more than 3 year's runoff, while in the Northeast and Northwest, storage is as little as 25% of the annual …

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Integrated Computational Chemistry System For Catalysts Design, Salai Cheettu Ammal, S. Takami, M. Kubo, A. Miyamoto Jan 1999

Integrated Computational Chemistry System For Catalysts Design, Salai Cheettu Ammal, S. Takami, M. Kubo, A. Miyamoto

Faculty Publications

The understanding of valuable catalytic and adsorptive properties of heterogeneous catalysts at atomic and electronic levels is essential for the design of novel catalysts. Computer simulation studies can significantly contribute to provide a rational interpretation of the observed experimental results and suggest modification of new catalysts. Our recent work on the application of integrated computer simulation methods to investigate the structure and catalytic properties of solid surfaces including zeolites, transition metals and their oxides have been reviewed in this paper. We have emphasized the effectivity and applicability of integrated computer simulation system to solve the problems in a variety of …

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How Children In Cults May Use Emancipation Laws To Free Themselves, Robin A. Boyle Jan 1999

How Children In Cults May Use Emancipation Laws To Free Themselves, Robin A. Boyle

Faculty Publications

The author examines how children who are born into cults or brought into them at a young age can use state emancipation laws to gain independence when they are in their mid-teens, so long as they can demonstrate criteria that their states have established. Commonly, states require a showing that the minor has achieved some level of economic self-sufficiency and can live emotionally and physically independently from his or her parents. There are some difficulties for cultic children in demonstrating these criteria, but the obstacles are not insurmountable.

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Material Balance Modification In One-Dimensional Modeling Of Porous Electrodes, Mukul Jain, John W. Weidner Jan 1999

Material Balance Modification In One-Dimensional Modeling Of Porous Electrodes, Mukul Jain, John W. Weidner

Faculty Publications

The material balance used previously in one-dimensional mathematical models of porous electrodes is invalid when there is a non-zero volume change associated with the reaction. It is shown here how the material balance should be modified either to account for a loss in volume, or to account for an inflow of electrolyte from the header into the active pores. A one-dimensional mathematical model is used to illustrate the effect of this correction on the prediction of the delivered capacity and the electrolyte concentration in a lithium/thionyl chloride primary battery.

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Correlation Of Double-Layer Capacitance With The Pore Structure Of Sol-Gel Derived Carbon Xerogels, Chuan Lin, James A. Ritter, Branko N. Popov Jan 1999

Correlation Of Double-Layer Capacitance With The Pore Structure Of Sol-Gel Derived Carbon Xerogels, Chuan Lin, James A. Ritter, Branko N. Popov

Faculty Publications

Nine different sol-gel derived carbon xerogels were prepared with different pore structures by varying the carbonization temperature (in flowing N2) and activation time (in 5% CO2 in N2). For each of these carbon xerogels, mesopore and micropore size distributions and cumulative surface areas were extracted from a density functional theory analysis. Increasing the carbonization temperature caused a decrease in the number of micropores in the 6 Å range but had little effect on the mesopore size distribution and thus mesopore cumulative surface area. Increasing the CO2 activation time caused an increase in the number …

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A Mathematical Model Of An Electrochemical Capacitor With Double-Layer And Faradaic Processes, Chuan Lin, James A. Ritter, Branko N. Popov, Ralph E. White Jan 1999

A Mathematical Model Of An Electrochemical Capacitor With Double-Layer And Faradaic Processes, Chuan Lin, James A. Ritter, Branko N. Popov, Ralph E. White

Faculty Publications

A mathematical model of an electrochemical capacitor with hydrous ruthenium oxide (RuO2·xH2O) electrodes including both double-layer and surface faradaic processes is developed to predict the behavior of the capacitor under conditions of galvanostatic charge and discharge. The effect of RuO2·xH2O particle size is studied and shows that the smaller the particles the better the performance because of the increased surface area per unit volume or mass. The model also predicts that the faradaic process increases significantly the energy per unit volume of the capacitor for power densities of …

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Development Of Carbon-Metal Oxide Supercapacitors From Sol-Gel Derived Carbon-Ruthenium Xerogels, Chuan Lin, James A. Ritter, Branko N. Popov Jan 1999

Development Of Carbon-Metal Oxide Supercapacitors From Sol-Gel Derived Carbon-Ruthenium Xerogels, Chuan Lin, James A. Ritter, Branko N. Popov

Faculty Publications

Sol-gel derived high surface area carbon-ruthenium xerogels were prepared from carbonized resorcinol-formaldehyde resins containing an electrochemically active form of ruthenium oxide. The electrochemical capacitance of these materials increased with an increase in the ruthenium content indicating the presence of pseudocapacitance associated with the ruthenium oxide undergoing reversible faradaic redox reactions. A specific capacitance of 256 F/g (single electrode) was obtained from a carbon xerogel containing 14 wt % Ru, which corresponded to more than 50% utilization of the ruthenium. The double layer accounted for 40% of this capacitance. This material was also electrochemically stable, showing no change in a cyclic …

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A Mathematical Model For Electroless Copper Deposition On Planar Substrates, M. Ramasubramanian, Branko N. Popov, Ralph E. White, K. S. Chen Jan 1999

A Mathematical Model For Electroless Copper Deposition On Planar Substrates, M. Ramasubramanian, Branko N. Popov, Ralph E. White, K. S. Chen

Faculty Publications

A mathematical model for the electroless deposition of copper on a planar electrode is presented and used to make time-dependent predictions on the various quantities in the system. The model takes into account mass transport by diffusion and migration, Butler-Volmer kinetics at the electrode surface, and mixed potential theory. A finite difference approach is used to solve the equations, and the resultant model is used to predict the concentration profiles, potential response, and plating rate as a function of time and concentration of various reactive components.

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Mathematical Modeling Of The Lithium Deposition Overcharge Reaction In Lithium‐Ion Batteries Using Carbon‐Based Negative Electrodes, Pankaj Arora, Marc Doyle, Ralph E. White Jan 1999

Mathematical Modeling Of The Lithium Deposition Overcharge Reaction In Lithium‐Ion Batteries Using Carbon‐Based Negative Electrodes, Pankaj Arora, Marc Doyle, Ralph E. White

Faculty Publications

No abstract provided.

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Influence Of Some Design Variables On The Thermal Behavior Of A Lithium‐Ion Cell, Gerardine G. Botte, Bradley A. Johnson, Ralph E. White Jan 1999

Influence Of Some Design Variables On The Thermal Behavior Of A Lithium‐Ion Cell, Gerardine G. Botte, Bradley A. Johnson, Ralph E. White

Faculty Publications

No abstract provided.

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A Simple Method For Determining Differential Diffusion Coefficients From Aqueous Electrolyte Diaphragm Cell Data At Temperatures Below 0°C, D. M. See, Ralph E. White Jan 1999

A Simple Method For Determining Differential Diffusion Coefficients From Aqueous Electrolyte Diaphragm Cell Data At Temperatures Below 0°C, D. M. See, Ralph E. White

Faculty Publications

No abstract provided.

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Methanol Fuel Cell Model: Anode, S. F. Baxter, V. S. Battaglia, Ralph E. White Jan 1999

Methanol Fuel Cell Model: Anode, S. F. Baxter, V. S. Battaglia, Ralph E. White

Faculty Publications

No abstract provided.

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Mathematical Modeling Of Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner Jan 1999

Mathematical Modeling Of Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner

Faculty Publications

Analytic solutions to the mathematical model of an electrochemical capacitor (EC) are used to study cell performance under two types of operating conditions: (i) constant current and (ii) electrochemical impedance spectroscopy. The analytic solution under constant-current operation is used to investigate the relative importance of ionic resistance in the separator, and ionic and electronic resistances in the porous electrode in the design and operation of an EC. Model results are presented that show the trade-off between energy and power density, as the physical properties of the cell components are varied (e.g., electrode thickness). The analytic solution …

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The American Courtroom Trial: Pop Culture, Courthouse Realities, And The Dream World Of Justice, David Ray Papke Jan 1999

The American Courtroom Trial: Pop Culture, Courthouse Realities, And The Dream World Of Justice, David Ray Papke

Faculty Publications

No abstract provided.

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Looking At Communities And Markets, Lan Cao Jan 1999

Looking At Communities And Markets, Lan Cao

Faculty Publications

No abstract provided.

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