Engineering Commons^™

Estimation Of The Diffusion Coefficient And Solubility For A Gas Diffusing Through A Membrane, Michael C. Kimble, Ralph E. White, Yu-Min Tsou, R. Neal Beaver

Faculty Publications

Analysis of the data obtained by the electrochemical monitoring technique for diffusion of a gas through a membrane is considered. It is shown that combining a numerical method with a nonlinear parameter estimation technique provides a means to determine values for the diffusion coefficient and the solubility of the diffusing gas. It is shown that better accuracy can be obtained for the diffusion coefficient and solubility of this gas by using the method presented and all experimental data rather than only part of the data, as has often been done in the past.

A Computer Program For Optimal Control Of Water Supply Pump Stations: Development And Testing, Donald V. Chase

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

This report presents an optimal control methodology designed to reduce the electrical consumption and operating costs at Army water supply pumping stations.

The methodology, contained in a computer program called Optimal Control of Pumping Stations (OCOPS), enables water utility managers and operators to reduce the electrical consumption at pumping stations while maintaining adequate storage and system pressures for fire protection. OCOPS can be applied to any water distribution system and is not limited to any number of pumps, pump stations, or storage tanks within the system.

The optimal control strategy developed is based on electricity unit charges, but can be …

The Development Of A Procedure To Forecast Traffic Volumes On Urban Segments Of The State And Interstate Highway Systems, Sunil K. Saha, Jon D. Fricker

JTRP Technical Reports

This study developed a multi-facted procedure to forecast traffic volumes on urban segments of the state and interstate highway systems for the Indiana Department of Transportation. A detailed statistical analysis was conducted to develop alternative models to forecast traffic. The models and the procedures described in this study's Final Report are intended to provide highway planners with a tool for simple, fast and inexpensive estimation of traffic projections. Emphasis was also placed on achieving reliable input information for the forecasts of any background factors (independent variables) used in the models. This study improves on previous efforts to build simple and …

Electrical Properties Of Hydrogenated Diamond, Sacharia Albin, Linwood Watkins

Electrical & Computer Engineering Faculty Publications

Hydrogen passivation of deep traps in diamond is demonstrated. Current‐voltage (I‐V) characteristics of polycrystalline thin film and bulk diamond were studied before and after hydrogenation. On hydrogenation, all the samples showed several orders of magnitude increase in conductivity. Hydrogenation was carried out under controlled conditions to study the changes in the I‐V characteristics of the samples. The concentration of uncompensated traps was varied systematically by hydrogenation. The concentration of electrically active hydrogen was determined from the I‐V data. It is shown that hydrogenation is an alternative to deep‐level transient spectroscopy, suitable for …

Influence Of Copper Doping On The Performance Of Optically Controlled Gaas Switches, St. T. Ko, V. K. Lakdawala, K. H. Schoenbach, M. S. Mazzola

Electrical & Computer Engineering Faculty Publications

The influence of the copper concentration in silicon-doped gallium arsenide on the photoionization and photoquenching of charge carriers was studied both experimentally and theoretically. The studies indicate that the compensation ratio (N_Cu/N_Si) is an important parameter for the GaAs:Si:Cu switch systems with regard to the turn-on and turn-off performance. The optimum copper concentration for the use of GaAs:Si:Cu as an optically controlled closing and opening switch is determined.

Application Of The Results Of Carbon Pellet Modeling To The Problem Of Plasma Penetration, L. L. Vahala, A. G. El Cashlan, G. A. Gerdin, P. B. Parks

Electrical & Computer Engineering Faculty Publications

The assumptions of the evaporation model for low-Z pellets interacting with magnetic fusion plasmas developed by Parks are tested. These assumptions are that the vapor density profile in the region adjacent to the pellet surface falls off with radial distance as r^-α , where 5 <α<6, and that the ionization time for the transition between charge states ז_f (i.e., for r < ~3 sonic radii). The first assumption is tested by solving a two-parameter eigenvalue problem for the evaporation cloud in the region interior to the sonic radius; the results are found to be consistent with the low-Z evaporation model. The second assumption, that ז_zi «ז_f, is tested at the sonic radius using the results from atomic physics and the low-Z evaporation model. It is found that indeed ז_zi «ז_f for plasmas with parameters close to thermonuclear conditions (e.g. CIT), but not for those of smaller Tokamaks such as …

Metamodeling Aspects Of Model Conceptualization, Wayne W. Wakeland

Complex Systems Faculty Publications and Presentations

This paper suggests a technique for improving the conceptualization of models. The key aspect of this technique is to set aside the main model for a period of time during the model conceptualization process and focus on building a "watchdog" submodel. The primary purpose of the watchdog submodel is to assure that the main model remains internally consistent during its operation. In the experience of this author, such a submodel can help to identify model conceptualization errors and to determine if a model is sufficiently "robust" to adequately replicate the behavior of the system being modeled.

This is not a …

Traffic Speed Report No. 123, David L. Cochran, Donald W. Genda

JTRP Technical Reports

No abstract provided.

The Use Of Bottom Ash In Highway Embankments, Subgrades, And Subbases : Executive Summary, Wei-Hsing Huang

JTRP Technical Reports

This research assessed those properties of power plant bottom ash likely to affect its use as highway fill or pavement material, based on laboratory investigation conducted on eleven Indiana bottom ashes. Laboratory tests included: chemical analysis, mineralogical study, microscopic examination of ash particles, specific gravity, grain size distribution, sulfate soundness, Los Angeles abrasion, permeability, shear strength, moisture-density relations, degradation under compaction, compressibility, and California bearing ratio.

The various test values and properties were compared to- those of representative granular soils or appropriate specifications. These comparisons provide information necessary for judging the suitability of bottom ash in Indiana highway construction.

The …

The Physical Durability And Electrical Resistivity Of Indiana Bottom Ash : Executive Summary, Te-Chih Ke

JTRP Technical Reports

This research assessed the long-term performance (durability) and the environmental effect (corrosiveness to adjacent metal structures) of Indiana bottom ashes, based mainly on laboratory investigation. The 5-cycle sodium sulfate soundness tests and the 50-cycle freeze-thaw tests were conducted to examine the physical durability. Four electrochemical characteristics (electrical resistivity, pH, soluble chloride, and soluble sulfate) were used to estimate the corrosion potential of Indiana bottom ashes.

Evaluation criteria for durability and corrosiveness of bottom ash, based on appropriate specifications for aggregates and past experiences for soils, were developed. The comparison of test results and the above criteria shows that Indiana bottom …

The Use Of Bottom Ash In Highway Embankments, Subgrades, And Subbases, Wei-Hsing Huang

JTRP Technical Reports

This research assessed those properties of power plant bottom ash likely to affect its use as highway fill or pavement material, based on laboratory investigation conducted on eleven Indiana bottom ashes. Laboratory tests included: chemical analysis, mineralogical study, microscopic examination of ash particles, specific gravity, grain size distribution, sulfate soundness, Los Angeles abrasion, permeability, shear strength, moisture-density relations, degradation under compaction, compressibility, and California bearing ratio.

The various test values and properties were compared to- those of representative granular soils or appropriate specifications. These comparisons provide information necessary for judging the suitability of bottom ash in Indiana highway construction.

The …

An Electronic Surveillance And Control System For Traffic Management On The Borman Expressway, Part I, Michael J. Cassidy, Kumares C. Sinha

JTRP Technical Reports

No abstract provided.

The Physical Durability And Electrical Resistivity Of Indiana Bottom Ash, Te-Chih Ke

JTRP Technical Reports

This research assessed the long-term performance (durability) and the environmental effect (corrosiveness to adjacent metal structures) of Indiana bottom ashes, based mainly on laboratory investigation. The 5-cycle sodium sulfate soundness tests and the 50-cycle freeze-thaw tests were conducted to examine the physical durability. Four electrochemical characteristics (electrical resistivity, pH, soluble chloride, and soluble sulfate) were used to estimate the corrosion potential of Indiana bottom ashes.

Evaluation criteria for durability and corrosiveness of bottom ash, based on appropriate specifications for aggregates and past experiences for soils, were developed. The comparison of test results and the above criteria shows that Indiana bottom …

Neural Networks In Manufacturing: Possible Impacts On Cutting Stock Problems, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

The potential of neural networks is examined, and the effect of parallel processing on the solution of the stock-cutting problem is assessed. The conceptual model proposed integrates a feature-recognition network and a simulated annealing approach. The model uses a neocognitron neural network paradigm to generate data for assessing the degree of match between two irregular patterns. The information generated through the feature recognition network is passed to an energy function, and the optimal configuration of patterns is computed using a simulated annealing algorithm. Basics of the approach are demonstrated with an example.

Knowledge-Based Prototype For Improving Scheduling Productivity, Colin Othniel Benjamin, Daniel L. Babcock, N. B. Yunus, John B. Kincaid

Engineering Management and Systems Engineering Faculty Research & Creative Works

The development of efficient construction plans and schedules presents continuing challenges to construction schedulers. Knowledge-based systems offer considerable potential as computer-based planning tools to aid the development of realistic project plans and schedules. This paper outlines the development of a knowledge-based prototype system for construction planning and scheduling and evaluates its effectiveness as a tool for improving the productivity of inexperienced construction project schedulers. The prototype, developed using the M.1 knowledge engineering shell, incorporates data bases, algorithm, and heuristics that mimic the decision process of expert construction project schedulers and identifies a work breakdown structure and precedence relationships. Inexperienced schedulers …

A Parallel Architecture For Stock Cutting Problem, Cihan H. Dagli, Alireza Hajakbari

Engineering Management and Systems Engineering Faculty Research & Creative Works

The problem of allocating irregular patterns arises frequently in applications where it has to be determined how a set of two-dimensional shapes will fit onto a stock sheet of finite dimensions with minimum waste. The use of the simulated annealing approach for the solution of this problem is described

Cost Justification Of An Expert System, Alice E. Smith, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

It is pointed out that, like other projects which spend corporate dollars, an expert system must be analyzed for its economic and strategic worth to the organization. Both traditional engineering economy project analysis and multivariate holistic methods can be applicable. The fundamental strategy of the analyst is to decide upon the evaluation methodologies, gather cost and benefit data, study the project from various perspectives, and present the results and recommendations.

Simulated Annealing Approach For Solving Stock Cutting Problem, Cihan H. Dagli, Alireza Hajakbari

Engineering Management and Systems Engineering Faculty Research & Creative Works

The simulated annealing approach is applied to stock cutting. The conceptual approach proposed uses an energy function that measures the area of the rectangular enclosure of all the patterns to be nested, the level of similarity between pattern pairs, and the amount of overlap among patterns in evaluating various pattern configurations to be generated by the simulated annealing algorithm. Three methods for pattern configuration generation are considered. The first method uses heuristics to generate the initial configuration. The second and third methods use random selection and random placement of patterns

1990 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Herpicc

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for agency officials and employees responsible for Indiana’s local road infrastructure.

Administration And Management Of Local Streets And Roads (1990 Update)—Chapter 8 Road Revenues, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

Funding highway, road and street work is a never-ending challenge. Local officials must be aware of the numerous sources of funds and the procedures involved in the acquisition and distribution of these dollars to local levels of government. Sources of funds are discussed. Answers to a number of road revenue questions are provided.

Simulation Of Free Radical Reactions In Biology And Medicine: A New Two-Compartment Kinetic Model Of Intracellular Lipid Peroxidation, Charles F. Babbs, Melissa Gale Steiner

Weldon School of Biomedical Engineering Faculty Publications

To explore mechanisms of free radical reactions leading to intracellular lipid peroxidation in living systems, we developed a computational model of up to 109 simultaneous enzymatic and free radical reactions thought to be involved in the initiation, propagation, and termination of membrane lipid peroxidation. Rate constants for the various reactions were obtained from the published literature. The simulation model included a lipid membrane compartment and an aqueous cytosolic compartment, between which various chemical species were partitioned. Lipid peroxidation was initiated by the iron-catalyzed, superoxide-driven Fenton reaction. A "C"-language computer program implemented numerical solution of the steady-state rate equations for concentrations …

Transistor-Based Measurements Of Electron Injection Currents In P-Type Gaas Doped 1018–1020 Cm-3, M. E. Klausmeier-Brown, M. R. Melloch, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

Measurements of electron currents injected into p+‐GaAs are presented for molecular beam epitaxially grown material doped from 2×1018 to 8×1019 cm−3 with Be. The collector current versus base‐emitter voltage characteristics of n‐p+‐n GaAs homojunction bipolar transistors are analyzed, and the results are interpreted in terms of the quantity (n0Dn), where n0 is the equilibrium minority‐carrier concentration and Dn is the minority‐carrier diffusion coefficient. The results are consistent with earlier measurements of (n0Dn) made using metalorganic chemical vapor deposited p+‐n GaAs solar …

High‐Efficiency Al0.22ga0.78as Solar Cells Grown By Molecular Beam Epitaxy, Michael R. Melloch, S. P. Tobin, C. Bajgar, A. Keshavarzi, T. B. Stellwag, G. B. Lush, Mark S. Lundstrom, K. Emery

Department of Electrical and Computer Engineering Faculty Publications

The quality of pn junction photodetectors made of Al0.2Ga0.8As has been investigated as a first step in the optimization of tandem solar cells. We have obtained 1 sun AM1.5 efficiencies of 16.1% for 0.25 cm2 Al0.22Ga0.78As solar cellsfabricated from molecular beam epitaxy (MBE) material. This efficiency is 3.2 percentage points higher than the previously best reported efficiency of 12.9% for an Al0.2Ga0.8As solar cell fabricated from MBE material.

A Pressure Sensitive Mat For Measuring Contact Pressure Distributions Of Patients Lying On Hospital Beds, Charles F. Babbs, Joe D. Bourland, George P. Graber, James T. Jones, William E. Schoenlein

Weldon School of Biomedical Engineering Faculty Publications

The authors describe a novel system for sensing and displaying the distribution of contact pressure caused by a patient's lying on a hospital bed. The system includes a flexible, pressure sensitive mat, electronics to activate the mat, a small computer to process data, and a color video display. The present prototypes can sense pressure at 1,536 discrete locations in a rectangular grid of 24 x 64 nodes, each node representing an area of 4 cm2. The computer receives data from each node and displays the results as a false-color map, refreshable every 5 seconds. The pressure sensitive mat itself includes …

Quantitation Of The Hydroxyl Radical By Reaction With Dimethyl Sulfoxide, Melissa G. Steiner, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This investigation was conducted to validate the use of dimethyl sulfoxide (DMSO) as a quantitative molecular probe for the generation of hydroxyl radicals (HO) in aqueous systems. Reaction of HO with DMSO produces methane sulfinic acid as a primary product, which can be detected by a simple calorimetric assay. To evaluate this method for estimating total HO production, we studied three model systems, including the Fenton reaction,  irradiation of water, and ultraviolet photolysis of hydrogen peroxide, for which the theoretical maximum yield of HO could be calculated and compared to measured DMSO oxidation. The results confirm that 0.05 to …

Free Radicals And The Etiology Of Colon Cancer, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This hypothesis paper reviews diverse evidence suggesting that intracolonic production of oxygen radicals may play a role in carcinogenesis. The hypothesis began to evolve when the author made the chance discovery that 1/10,000 dilutions of feces generated detectable quantities of highly reactive hydroxyl radicals (HO). The rate of HO formation, detected using DMSO as a molecular probe, was quite remarkable, corresponding to that which would be produced by over 10,000 rads of gamma irradiation per day, absorbed in the periphery of the fecal mass adjacent to the mucosa. The relatively high concentrations of iron in feces, together with the ability …

Accuracy And Precision Of Computer-Simulated Tissue Temperatures In Individual Human Intracranial Tumours Treated With Interstitial Hyperthermia, J A. Deford, Charles F. Babbs, U H. Patel, N E. Fearnot, J A. Marchosky, C J. Moran

Weldon School of Biomedical Engineering Faculty Publications

Accurate knowledge of tissue temperature is necessary for effective delivery of clinical hyperthermia in the treatment of malignant tumours. This report compares computer-predicted versus measured intratumoral temperatures in 11 human subjects with intracranial tumours, treated with a conceptually simple 'conductive' interstitial hyperthermia system. Interstitial hyperthermia was achieved by the use of parallel arrays of implanted, electrically heated catheters. The tissue was warmed by thermal conduction and blood convection. Simulation of intratumoral temperatures was achieved by solving a modified bioheat transfer equation on a digital computer using a finite difference method. Comparison of intratumoral temperatures from simulations and measured values differed …

Surface Passivation Effects Of As2s3 Glass On Self‐Aligned Algaas/Gaas Heterojunction Bipolar Transistors, H. L. Chuang, M. S. Carpenter, Michael R. Melloch, Mark S. Lundstrom, E. Yablonovitch, T. J. Gmitter

Department of Electrical and Computer Engineering Faculty Publications

A recently developed As₂S₃ chemical treatment was used to passivate the perimeters of self‐aligned heterojunction bipolar transistors (HBTs). The As₂S₃chemical treatment significantly lowered the base current resulting in a two order of magnitude reduction in the collector current density at which dc current gain was observed (β=1). No degradation with time has been observed in the electrical characteristics of the chemically treated HBTs. This absence of degradation is attributed to the impermeability to oxygen of the As2S3 glass which coats the perimeter of the HBT after chemical treatment.

Orientation-Dependent Perimeter Recombination In Gaas Diodes, T. B. Stellwag, Michael R. Melloch, Mark S. Lundstrom, M. S. Carpenter, R. F. Pierret

Department of Electrical and Computer Engineering Faculty Publications

Perimeter recombination currents affect the performance of GaAs-based devices such as solar cells, heterojunction bipolar transistors, and injection lasers. We report that the n SEf 2 perimeter recombination current has a strong orientation dependence. More than a factor of five variation in the surface recombination current at mesa-etched edges has been observed. These results suggest that with proper device design, perimeter recombination currents could be substantially reduced.

Theoretical Basis For Controlling Minimal Tumor Temperature During Interstitial Conductive Heat Therapy, Charles F. Babbs, Neal E. Fearnot, J A. Marchosky, C J. Moran, James T. Jones, T D. Plantenga

Weldon School of Biomedical Engineering Faculty Publications

This paper describes simulation of steady-state intratumoral temperatures achieved by a simple modality of local heat therapy: interstitial treatment with parallel arrays of warmed, conductive heating elements. During “conductive heating” power is directly deposited only in the interstitial probes. Adjacent tissue is warmed by heat conduction. Simulations of interstitial conductive heating involved solution of the bioheat transfer equation on a digital computer using a finite difference model of the treated tissue. The simulations suggest that when the complete temperature distributions for conductive interstitial hyperthermia are examined in detail, substantial uniformity of the temperature distributions is evident. Except for a thin …