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Articles 5401 - 5430 of 6327

Full-Text Articles in Engineering

The Development Of A Prototype Congestion Management System For The State Of Indiana: Phase 1, Nishantha R. Gunawardena, Kumares C. Sinha Jan 1994

The Development Of A Prototype Congestion Management System For The State Of Indiana: Phase 1, Nishantha R. Gunawardena, Kumares C. Sinha

JTRP Technical Reports

This study details a comprehensive set of guidelines and a work-plan that consists of nine elements that need to be developed in implementing a congesion management system. A procedure has been developed by means of which congestion on roadway links can be identified at a macroscopic level using daily volume counts (ADT) after which, links that are identified as being congested will be subjected to a more detailed microscopic study using hourly volume counts to determine extent, duration and severity of congestion.


Use Of Waste Foundry Sand In Highway Construction : Final Report, Sayeed Javed Jan 1994

Use Of Waste Foundry Sand In Highway Construction : Final Report, Sayeed Javed

JTRP Technical Reports

The promulgation of environmental regulations, both at the federal and state level, have resulted in increased control over both the hazardous and nonhazardous wastes generated in the foundry industry. The increased regulation action has in many cases resulted in foundry wastes being disposed in highly engineered and often times costly land disposal facilities. Beneficial reuse represents an alternative to disposal and the associated problems of diminished landfill capacity and increased tipping fees. This study contains: synthesis of all available information and laboratory results for different beneficial uses of waste foundry sand. Among the different beneficial uses, waste foundry sand as …


The Components And Benefits Of An Advanced Surface Arterial Traffic Management System, Ted M. Andrews, Kumares C. Sinha Jan 1994

The Components And Benefits Of An Advanced Surface Arterial Traffic Management System, Ted M. Andrews, Kumares C. Sinha

JTRP Technical Reports

Traffic congestion has become an increasing problem on major surface arterial roadways. Demand for accessibility to adjacent land uses yields increased vehicular turning movement activity at driveways and intersections. As turning and cross-road traffic volumes increase, the need for traffic signalization will eventually be warranted. When numerous, independently operating traffic signals are present on a given arterial roadway, adverse effects can result. First, continous movement along the arterials at a desirable speed may not be assured. Second, vehicular delay will increase because of the slower operating speeds and increased number of stops. Third, safety can be threatened as poor traffic …


An Indot Lessons Learned Constructability Program And Integrated Multimedia System, Bob G. Mccullouch, Robert Michael Patty Jan 1994

An Indot Lessons Learned Constructability Program And Integrated Multimedia System, Bob G. Mccullouch, Robert Michael Patty

JTRP Technical Reports

To improve constructability, experienced design and construction engineers often select processes and develop details that require less labor, equipment, or management resources to build. These innovative ideas, enabling circumstances, and their effect on the construction process are not usually recorded in a reusable format. Without such a mechanism, recalling this experience under the appropriate circumstances, or transferring the technology to new management has generally not happened. Further, civil engineers are generally educated to optimize cost by minimizing the material quantity. Through experience gained after graduation, they are expected to pick up options for engineering impact on the labor, equipment, and …


Pavement Drainage And Pavement Shoulder Joint Evaluation Numerical Analysis Of Infiltration And Drainage In Pavement Systems, Reynaldo David. Espinoza, Philippe L. Bourdeau, Thomas D. White Dec 1993

Pavement Drainage And Pavement Shoulder Joint Evaluation Numerical Analysis Of Infiltration And Drainage In Pavement Systems, Reynaldo David. Espinoza, Philippe L. Bourdeau, Thomas D. White

JTRP Technical Reports

The continuing loss of pavement performance observed in the U.S. transportation infrastructure system raises the issue of the subdrainage design. Experience with the Indiana highways indicates that the lack of adequa the sub-drainage is probably a major cause of pavement distress. In order to provide highway engineers with a methodology to analyze the water migration and drainage into pavement systems a new numerical model has been developed. The numerical scheme is a finite difference formulation of the equations of water flow in unsaturated porous media. The resulting system of equations used is nonlinear and state-of-the-art numerical techniques have been used …


Introduction To Leveling - A Training Guide For Road Maintenance Personnel In Indiana's Counties, Cities And Towns, Herpicc Dec 1993

Introduction To Leveling - A Training Guide For Road Maintenance Personnel In Indiana's Counties, Cities And Towns, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This booklet presents the basic concepts of leveling and is intended as a reference for those employees performing essential leveling operations for the construction of roads and drainage structures.


Toward Virtual Digital Mammograms For Research And Training In Tumor Detection, Charles F. Babbs, Leslie A. Geddes Dec 1993

Toward Virtual Digital Mammograms For Research And Training In Tumor Detection, Charles F. Babbs, Leslie A. Geddes

Weldon School of Biomedical Engineering Faculty Working Papers

Research in the processing, compression, transmission, and interpretation of digital radiographic images requires evaluation of a wide variety of test images, varying in format, in spatial resolution, and in anatomic content. To evaluate the diagnostic performance of observers using novel versus conventional image formats, large numbers of test images containing known abnormalities are required. This report describes a method for creating high resolution, virtual digital mammograms from computational models of the human breast that include branched lobulated ducts and suspensory ligaments embedded in fatty subcutaneous tissue. Breast phantoms may include any of three types of simulated tumors (fibroadenomas, invasive ductal …


Rate Equations For The Phonon Peak In Resonant-Tunneling Structures, Roger Lake, Gerhard Klimeck, J. P. Anantram, Supriyo Datta Nov 1993

Rate Equations For The Phonon Peak In Resonant-Tunneling Structures, Roger Lake, Gerhard Klimeck, J. P. Anantram, Supriyo Datta

Birck and NCN Publications

The ratio of the phonon peak current to the main peak current in double-barrier resonant-tunneling structures is significantly enhanced by barrier asymmetry. Previously, using the Keldysh formalism, we derived analytical expressions, valid in the zero-temperature, high-bias regime, which explained this eftect. We now provide analytical expressions valid for finite temperature and bias obtained from (i) an intuitive derivation using a rate equation approach and (ii) a more general derivation using the Keldysh formalism. The results of the two difFerent approaches are shown to be essentially identical for the ex- perimental device parameters. The finite temperature expressions shed light on the …


A Summary Of Highway Revenues, Expenses And Distributions: 1986 Through 1993, Herpicc Nov 1993

A Summary Of Highway Revenues, Expenses And Distributions: 1986 Through 1993, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This report shows the history of receipts, expenses and distributions of revenues that provide funding to all local governments for highway, road and street work.


The Effect Of Texture And Microstructure On Equibiaxial Fracture In Gallium Embrittled Aluminum Sheet, Michael Daniel Grah Oct 1993

The Effect Of Texture And Microstructure On Equibiaxial Fracture In Gallium Embrittled Aluminum Sheet, Michael Daniel Grah

Open Access Dissertations

No abstract provided.


Flowable Fill, Herpicc Aug 1993

Flowable Fill, Herpicc

Indiana Local Technical Assistance Program (LTAP) Technical Reports

This publication supplies information on Controlled Low Strength Material (CLSM) and performance related to material characteristics and mixture properties.


Applicant's Guide To Traffic Impact Studies, Soumya Sekhar Dey, Jon D. Fricker Jun 1993

Applicant's Guide To Traffic Impact Studies, Soumya Sekhar Dey, Jon D. Fricker

JTRP Technical Reports

No abstract provided.


Laboratory Study On Properties Of Rubber-Soils, Imtiaz Ahmed May 1993

Laboratory Study On Properties Of Rubber-Soils, Imtiaz Ahmed

JTRP Technical Reports

The waste tire problem in the United States is of great magnitude and has far reaching environmental and economic implications. This study investigates the feasibility of using tire chips, alone and mixed with soils, as lightweight material in highway embankments . The report contains: synthesis of all available information and results from laboratory testing of tire chips, rubber-Ottawa sand, and rubber-Crosby till. It is found that rubber-sand with chip/mix ratios of 33% or less exhibits excellent engineering properties: easy to compact; low dry density; low compressibility; high strength; and excellent drainage characteristics. On the whole, the rubber-Crosby till mixes do …


Rate Equations From The Keldysh Formalism Applied To The Phonon Peak In Resonant-Tunneling Diodes, Roger Lake, Gerhard Klimeck, Supriyo Datta Mar 1993

Rate Equations From The Keldysh Formalism Applied To The Phonon Peak In Resonant-Tunneling Diodes, Roger Lake, Gerhard Klimeck, Supriyo Datta

Birck and NCN Publications

Starting from the Keldysh formalism, general analytical expressions are derived for the current and the occupation of the well in the presence of inelastic scattering, both at the main peak and at the pho- non peak. These expressions are then evaluated from a continuous coordinate representation of a double-barrier potential profile and also from a tight-binding model of a weakly coupled central site. The resulting expressions are similar, and the analytical expressions derived from the continuous coordi- nate representation compare well with the results obtained from numerical simulations. The analytical expressions and the numerical results show that unlike the main …


Pavement Drainage And Pavement-Shoulder Joint Evaluation And Rehabilitation, Zubair Ahmed, Thomas D. White, Philippe L. Bourdeau Mar 1993

Pavement Drainage And Pavement-Shoulder Joint Evaluation And Rehabilitation, Zubair Ahmed, Thomas D. White, Philippe L. Bourdeau

JTRP Technical Reports

The objectives of this research were i) to evaluate the performance of pavement subdrainage systems ii) study the behavior of moisture conditions below pavements and iii) provide recommendations for unproved drainage criteria based on analysis of field data. Existing and retrofitted subdrainage collector systems were inspected through external visual inspection in combination with a probe for internal inspection. Distresses and deficiencies in construction observed were listed and compiled on video. A methodology for inspection is presented that can be used by highway agencies in monitoring the condition, need for maintenance, and performance of collector systems. Pavements with various types of …


Embankment Widening And Grade Raising On Soft Foundation Soils, Phase 2, Scott Ludlow, Wai-Fah Chen, Philippe L. Bourdeau, C. W. Lovell Jan 1993

Embankment Widening And Grade Raising On Soft Foundation Soils, Phase 2, Scott Ludlow, Wai-Fah Chen, Philippe L. Bourdeau, C. W. Lovell

JTRP Technical Reports

No abstract provided.


Subgrade Resilient Modulus For Pavement Design And Evaluation, Woojin Lee, Nihal Chand Bohra, A. G. Altschaeffl, Thomas D. White Jan 1993

Subgrade Resilient Modulus For Pavement Design And Evaluation, Woojin Lee, Nihal Chand Bohra, A. G. Altschaeffl, Thomas D. White

JTRP Technical Reports

No abstract provided.


Debonding In Pretensioned Beams-Precast Strands, Part 2: Simply Supported Tests, O. A. Abdalla, J. A. Ramirez, Robert H. Lee Jan 1993

Debonding In Pretensioned Beams-Precast Strands, Part 2: Simply Supported Tests, O. A. Abdalla, J. A. Ramirez, Robert H. Lee

JTRP Technical Reports

No abstract provided.


Strand Debonding In Pretensioned Beams - Precast Prestressed Concrete Bridge Girders With Debonded Strands - Continuity Issues, O. A. Abdalla, J. A. Ramirez, Robert H. Lee Jan 1993

Strand Debonding In Pretensioned Beams - Precast Prestressed Concrete Bridge Girders With Debonded Strands - Continuity Issues, O. A. Abdalla, J. A. Ramirez, Robert H. Lee

JTRP Technical Reports

No abstract provided.


Multiobjective Design Of Service Routes, J. R. Wright, Jin-Yuan Wang Jan 1993

Multiobjective Design Of Service Routes, J. R. Wright, Jin-Yuan Wang

JTRP Technical Reports

The purpose of this research has been the design of a computer-based decision support system for use in the design of service routes on the Indiana intrastate highway system. The following work has been completed for this purpose:

1) Acquisition of a 1:100,000 scale DLG data representation of the entire state transportation network.

2) Reclassification of those data with the aid of a computer-based interactive data filter and participation by DOT maintenance personnel from 6 districts.

3) Development of several route design algorithm components designed specifically for addressing the problem of routing snow and ice control vehicles for INDOT.

4) …


1993 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Herpicc Jan 1993

1993 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.


Interposed Abdominal Compression Cardiopulmonary Resuscitation: Are We Missing The Mark In Clinical Trials?, Charles F. Babbs Jan 1993

Interposed Abdominal Compression Cardiopulmonary Resuscitation: Are We Missing The Mark In Clinical Trials?, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Straightforward considerations of abdominal anatomy in human beings set tight constraints on the theoretically optimal technique for abdominal compressions during interposed abdominal compression (IAC)-CPR. The location and extent of the abdominal aorta lead naturally to the recommendation that IAC be applied at a level corresponding to the lower two thirds of the sterno-umbilical line. The force vector required to achieve contact compression of the abdominal aorta is inclined in the transverse plane at an angle of 11 degrees from the vertical toward the left. Such slightly angled compression subjects the abdominal aorta to maximally flattening; while the inferior vena cava …


Interposed Abdominal Compression-Cpr: A Case Study In Cardiac Arrest Research, Charles F. Babbs Jan 1993

Interposed Abdominal Compression-Cpr: A Case Study In Cardiac Arrest Research, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

When the abdomen is compressed manually in counterpoint to the rhythm of chest compression, in the performance of interposed abdominal compression-CPR, artificial circulation is approximately doubled in animal experiments and in electronic models of the circulatory system. These studies suggest that external manual compression of the abdominal aorta acts like an intra-aortic balloon pump to increase aortic pressure, whereas external manual compression of the abdominal veins acts to prime the right heart and pulmonary vessels before the next chest compression. As a result, perfusion pressures and flows are increased. Several clinical studies of this technique have shown promising results, including …


Development Of A Rapidly Computable Descriptor Of Prostate Tissue Temperature During Transurethral Conductive Heat Therapy For Benign Prostate Hyperplasia, U H. Patel, Charles F. Babbs Jan 1993

Development Of A Rapidly Computable Descriptor Of Prostate Tissue Temperature During Transurethral Conductive Heat Therapy For Benign Prostate Hyperplasia, U H. Patel, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Benign prostate hyperplasia (BPH) is a condition in older men in which the mass of tissue in the prostate gland gradually increases over the course of many years, ultimately leading to urinary outflow obstruction. Current treatment of this condition is to surgically remove the obstructing tissue. One novel alternative therapy being studied is transurethral thermocoagulation of excessive prostatic mass. In this approach, a heat emitting catheter is placed in the prostatic urethra, and the intraprostatic segment of the catheter is heated to temperatures above 60 oC for one hour. Two dimensional cylindrical coordinate computer simulations of this treatment modality were …


A Spectral Flux Method For Solving The Boltzmann Equation, Muhammad A. Alam, Mark A. Stettler, Mark S. Lundstrom Jan 1993

A Spectral Flux Method For Solving The Boltzmann Equation, Muhammad A. Alam, Mark A. Stettler, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

A spectral method for solving the Boltzmann equation by the scattering matrix approach is presented, The algorithm discussed can be used to simulate both bulk and device properties with arbitrary field profiles. Although the primary goal is to reduce the data storage problem of the scattering matrix approach, many of the concepts and mathematical properties developed may be useful for other traditional spectral methods as well.


Minority-Carrier Mobility Enhancement In P+ Ingaas Lattice Matched To Inp, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, D. Ritter, R. A. Hamm Jan 1993

Minority-Carrier Mobility Enhancement In P+ Ingaas Lattice Matched To Inp, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, D. Ritter, R. A. Hamm

Department of Electrical and Computer Engineering Faculty Publications

Minority electron mobilities in pf-In0.ssGac4, As have been measured with the zero field time-of-flight technique. The room-temperature (297 K) minority electron mobilities for p+-In,, 53Gac47A~ doped 0.9 and 3.1 x 10” cmm3 are found to be 2900 and 3300 cm* V-’ s-l, respectively. These are the first measurements to demonstrate enhancement in minority-carrier mobility as doping is increased for heavily doped Ines3Gae.4+s. This enhancement in mobility as doping is increased is similar to that observed in p+-GaAs, which has been attributed to reductions in plasmon and carrier-carrier scattering between minority electrons and majority holes.


Concentration‐Dependent Optical‐Absorption Coefficient In N‐Type Gaas, Gregory Benedict Lush, H. F. Macmillan, S. Asher, Michael R. Melloch, Mark S. Lundstrom Jan 1993

Concentration‐Dependent Optical‐Absorption Coefficient In N‐Type Gaas, Gregory Benedict Lush, H. F. Macmillan, S. Asher, Michael R. Melloch, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The doping-dependent, near-band-edge optical-absorption coefficient CY(h v) was deduced from optical transmission measurements in n-type GaAs thin films. The selenium-doped films were grown by metalorganic chemical-vapor deposition and do ed to produce room-temperature electron concentrations from 1.3 x 10” to 3.8X 1018 cm- P . The transmission measurements covered photon energies between 1.35 and 1.7 eV and were performed on double heterostructures with the substrate removed by selective etching. The results show good qualitative agreement with previous studies and good quantitative agreement, except for the heavily doped samples. For na=3.8 X 10” cme3, a( 1.42 eV> is approximately four times …


Experimental Observation Of A Minority Electron Mobility Enhancement In Degenerately Doped P-Type Gaas, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, T. J. De Lyon, J. M. Woodall Jan 1993

Experimental Observation Of A Minority Electron Mobility Enhancement In Degenerately Doped P-Type Gaas, E. S. Harmon, Michael L. Lovejoy, Michael R. Melloch, Mark S. Lundstrom, T. J. De Lyon, J. M. Woodall

Department of Electrical and Computer Engineering Faculty Publications

The variation of minority electron mobility with doping density in p+-GaAs has been measured with the zero-field time-of-flight technique. The results from a series of nine GaAs films doped between 1 X lOI and 8 X 10” cmm3 show the mobility decreasing from 1950 cm2 V-’ s-l at 1 X 10” cmm3 to 1370 cm2 V-l s-l at 9X 10” cmB3. For the doping range 9 x 1018-8x 1019 cme3, the decreasing trend in mobility is reversed. The measured mobility of 3710 cm2 V-’ s-l at 8 X 10” cmp3 is about three times higher than the measured value at …


Feature Extraction And Classification Algorithms For High Dimensional Data, Chulhee Lee, David Landgrebe Jan 1993

Feature Extraction And Classification Algorithms For High Dimensional Data, Chulhee Lee, David Landgrebe

Department of Electrical and Computer Engineering Technical Reports

In this research, feature extraction and classification algorithms for high dimensional data are investigated. Developments with regard to sensors for Earth observation are moving in the direction of providing much higher dimensional multispectral imagery than is now possible. In analyzing such high dimensional data, processing time becomes an important factor. With large increases in dimensionality and the number of classes, processing time will increase significantly. To address this problem, a multistage classification scheme is proposed which reduces the processing time substantially by eliminating unlikely classes from further consideration at each stage. Several truncation criteria are developed and the relationship between …


Chemical Admixtures Of Highway Concrete: Fundamental Research And A Guide To Usage, Sidney Diamond, Keisuke Matsukawa Jan 1993

Chemical Admixtures Of Highway Concrete: Fundamental Research And A Guide To Usage, Sidney Diamond, Keisuke Matsukawa

JTRP Technical Reports

No abstract provided.