Engineering Commons^™

Roller Compacted Concrete For Highway Applications, Jorge Gomez-Dominguez

Indiana Local Technical Assistance Program (LTAP) Publications

A series of laboratory studies were carried out to investigate the behavior and characteristics of Roller Compacted Concrete (RCC) for highway applications.

A Rapid, Widely Applicable Screen For Drugs That Suppress Free Radical Formation In Ischemia/Reperfusion, Steven C. Salaris, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Substantial injury can occur during reoxygenation of previously ischemic tissue in many experimental models, as the result of the generation of oxygen-derived free radicals. To test the antiradical activity of potentially protective compounds in this setting, we developed a simple screening system, applicable to fresh biopsy specimens, in which warm ischemia and reoxygenation of excised tissue are performed in vitro. Tissue production of malondialdehyde (MDA) equivalents is used as a nonspecific-but-sensitive marker of oxygen radical damage. Test compounds with putative antiradical activity are added prior to the reoxygenation phase, and their ability to suppress MDA production is an index of …

A Rapid, Widely Applicable Screen For Drugs That Suppress Free Radical Formation In Ischemia/Reperfusion, Steven C. Salaris, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Substantial injury can occur during reoxygenation of previously ischemic tissue in many experimental models, as the result of the generation of oxygen-derived free radicals. To test the antiradical activity of potentially protective compounds in this setting, we developed a simple screening system, applicable to fresh biopsy specimens, in which warm ischemia and reoxygenation of excised tissue are performed in vitro. Tissue production of malondialdehyde (MDA) equivalents is used as a nonspecific-but-sensitive marker of oxygen radical damage. Test compounds with putative antiradical activity are added prior to the reoxygenation phase, and their ability to suppress MDA production is an index of …

Evidence For Band-Gap Narrowing Effects In Be-Doped, P-P+ Gaas Homojunction Barriers, H. L. Chuang, Paul David Demoulin, M. E. Klausmeier-Brown, Michael R. Melloch, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The electrical performance of Be‐doped, p‐p+ GaAs homojunction barriers is characterized and analyzed. The results of the analysis show that minority‐carrier electrons, at 300 K, have a mobility of 4760 cm2/V s at a hole concentration of 2.3×1016 cm−3, and that the effective recombination velocity for these homojunction barriers is about 6×104 cm/s. We present evidence that this unexpectedly high recombination velocity is a consequence of an effective reduction in band gap due to the heavy impurity doping. The effective band‐gap shrinkage in this Be‐doped material grown by molecular‐beam epitaxy appears to be comparable to that already …

Effects Of Heavy Impurity Doping On Electron Injection In P+-N Gaas Diodes, M. E. Klausmeier-Brown, Mark S. Lundstrom, Michael R. Melloch, S. P. Tobin

Department of Electrical and Computer Engineering Faculty Publications

Measurements of electron injection currents in p+‐n diodes are presented for a range of p‐type dopant concentrations. A successive etch technique was used to characterize the electron injection current in terms of the product (noDn). Measurements are presented for Zn‐doped GaAs solar cells with p‐layer hole concentrations in the range 6.3×1017−1.3×1019 cm−3. The results demonstrate that so‐called band‐gap narrowing effects substantially increase the injected electron current in heavily doped p‐type GaAs. These heavy doping effects must be accounted for in the modeling and design of GaAs solar cells and heterostructure …

Myocardial Perfusion Pressure: A Predictor Of 24hour Survival During Prolonged Cardiac Arrest In Dogs, Karl B. Kern, Gordon A. Ewy, William D. Voorhees, Charles F. Babbs, Willis A. Tacker

Weldon School of Biomedical Engineering Faculty Publications

Myocardial perfusion pressure, defined as the aortic diastolic pressure minus the right atria1 diastolic pressure, correlates with coronary blood flow during cardiopulmonary resuscitation (CPR) and predicts initial resuscitation success. Whether this hemodynamic parameter can predict 24-h survival is not known. We examined the relationship between myocardial perfusion pressure and 24-h survival in 60 dogs that underwent prolonged (20 min) ventricular fibrillation and CPR. Forty-two (70%) animals were initially resuscitated and 20 (33%) survived for 24 h. Myocardial perfusion pressure was significantly greater when measured at 5, 10, 15 and 20 min of ventricular fibrillation in the resuscitated animals than in …

Fly Ash Concrete For Highway Use : Executive Summary, Sidney Diamond, J. Olek

JTRP Technical Reports

No abstract provided.

The Development Of Optimal Strategies For Maintenance, Rehabilitation And Replacement Of Highway Bridges, Vol. 1: The Elements Of The Indiana Bridge Management System (Ibms), Kumares C. Sinha, Mitsuru Saito, Yi Jiang, Sudhir Murthy, Ah Beng Tee, Mark D. Bowman

JTRP Technical Reports

No abstract provided.

Layer Coefficients In Terms Of Performance And Mixture Characteristics, Brian David Coree, Thomas D. White

JTRP Technical Reports

No abstract provided.

Experimental And Theoretical Studies On Design Calculations For Latent Heat Storage, Dieter Lindemann

Open Access Theses

Research was conducted to obtain design data of latent heat-of-fusion thermal energy storage (LHTES) devices. The devices studied utilize a porous medium (PM) to increase the effective conductivity of the storage system. Therefore the melting and freezing process is accelerated. Metal shavings and metal spheres were used as porous media and water as the phase change medium (PCM). A simple experimental method to measure the conductivity of a water-metal mixture or ice-metal mixture was applied to obtain conductivity data. These measurements can be considered fairly accurate because measured conductivity of pure water and of pure ice agreed very well with …

Crack Growth Gages For Monitoring Fatigue Damage : Final Informational Report, Charles Kpakpo Nmai, Mark D. Bowman

JTRP Technical Reports

No abstract provided.

Investigation On Latex-Modified Bridge Deck Overlay Concrete, Sidney Diamond

JTRP Technical Reports

No abstract provided.

Cost Reduction And Increased Efficacy Of Growth Retardant Mixtures For Vegetation Management Along Indiana Roadsides, D. James Morré

JTRP Technical Reports

No abstract provided.

Computational Package For Predicting Pile Stresses And Capacity : Executive Summary, Ahmad Amr Darrag

JTRP Technical Reports

No abstract provided.

Evaluation Of The Coordination Of Weigh-In-Motion Truck Data In Indiana (Fy86 Rtap Wim Project) : Interim Report, John Daniel Riverson, Kumares C. Sinha

JTRP Technical Reports

No abstract provided.

Pile Capacity Predictions Using Static And Dynamic Load Testing, Ahmad Amr Darrag

JTRP Technical Reports

No abstract provided.

An Evaluation Of Disadvantaged Business Enterprise Requirements For Indiana Department Of Highway Construction Projects : Executive Summary, Patrick A. Killian, Donn Edward Hancher

JTRP Technical Reports

No abstract provided.

Implementation Program To Improve Embankment Design And Performance With Indiana Soils, A. G. Altschaeffl, Sabanayagam Thevanayagam, G. Girish) Agrawal

JTRP Technical Reports

No abstract provided.

Development Of An Overlay Design Procedure For Flexible Pavements In Indiana : Executive Summary, Jay K. Lindly, Thomas D. White

JTRP Technical Reports

No abstract provided.

Effects Of Asphalt Composition And Compaction On The Performance Of Asphalt Pavement Mixtures, Leonard E. Wood, A. G. Altschaeffl

JTRP Technical Reports

No abstract provided.

Material Characterization Of Hot-Mix Recycled Bituminous Pavements, Leonard E. Wood, Ahmed Samy Noureldin

JTRP Technical Reports

No abstract provided.

Development Of An Overlay Design Procedure For Flexible Pavements In Indiana, Jay K. Lindly, Thomas D. White

JTRP Technical Reports

No abstract provided.

Traffic Control In Maintenance And Construction Areas, Gilbert T. Satterly

Indiana Local Technical Assistance Program (LTAP) Publications

This booklet is a revised chapter of the Handbook of Traffic Control Practices for Low-Volume Roads in Indiana, Publication No. H-84-3 by the Highway Extension and Research Project for Indiana Counties and Cities.

The purpose of this chapter is to provide information and guidelines to those persons involved in providing traffic control devices to warn and guide motorists and pedestrians in construction and maintenance areas on two-lane two-way roadways. This booklet is to serve as a supplement to the Indiana Manual on Uniform Traffic Control Devices for Streets and Highways.

Unpaved Roads Maintenance Management, Charles F. Scholer, John D. N. Riverson

Indiana Local Technical Assistance Program (LTAP) Publications

A guide for Counties, Cities, and Towns of Indiana to increase the understanding of the performance, maintenance and management of unpaved roads.

Handbook For Traffic Control In Construction And Maintenance Areas, Herpicc

Indiana Local Technical Assistance Program (LTAP) Publications

This booklet is a field reference for maintenance employees to assist in setting up the traffic control.

Bias‐Dependent Photoresponse Of P+In Gaas/Alas/Gaas Diodes, Michael R. Melloch, C. P. Mcmahon, Mark S. Lundstrom, J. A. Cooper Jr., Q D. Qian, S. Bandyopadhyay

Department of Electrical and Computer Engineering Faculty Publications

We report photocollection efficiency measurements of p + in GaAs! AIAs!GaAs diodes fabricated on films grown by molecular beam epitaxy, Both the zero-bias and bias-dependent photocollection characteristics can be explained by assuming that the band discontinuity between AlAs and GaAs is mostly accommodated i.n the valence band.

Colorimetric Assay For Methanesulfinic Acid In Biological Samples, Charles F. Babbs, Melissa J. Gale

Weldon School of Biomedical Engineering Faculty Publications

We describe a simple colorimetric method to measure 30 to 300 M concentrations of sulfinic acids in biologic samples. The procedure employs the coupling reaction of an aromatic diazonium salt (Ar-N=N+) with the sulfinic acids (RSOOH) to produce a colored diazosulfone derivative (Ar-N=N-SOOR), which can be selectively extracted into an organic solvent. Linearity and noninterference by liver homogenate, phenols, amines, and thousand-fold or greater excesses of sulfate, thiol, and dimethyl sulfoxide are demonstrated. Sensitivity of the method is about 10 nmol per sample. Because methanesulfinic acid is the principal product of the action of hydroxyl radicals upon dimethyl sulfoxide, and …

Protection From Reperfusion Injury In The Isolated Rat Heart By Postischaemic Deferoxamine And Osypurinol Administration, Stephen F. Badylak, Abby Simmons, John Turek, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The Langendorff isolated rat heart preparation was used to determine the effect of oxypurinol, a xanthine oxidase inhibitor, and deferoxamine, an iron binding agent, on the extent of myocardial reperfusion injury after 60 minutes of ischaemia. Thirty rats were divided into three groups of 10. and an isolated heart preparation made from each rat. The isolated hearts were perfused for 15 minutes with a modified Krebs-Henseleit perfusate solution to permit stabilisation of the preparation. Each heart was then subjected to 60 minutes of total ischaemia at 37°C followed by 60 minutes of reperfusion with either saline treated perfusate, oxypurinol treated …

Importance Of Space-Charge Effects In Resonant Tunneling Devices, M. Cahay, M. Mclennan, D. Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The consideration of space charge in the analysis of resonant tunneling devices leads to a substantial modification of the current-voltage relationship. The region of negative differential resistance (NDR) is shifted to a higher voltage, and broadened along the voltage axis. Moreover, the peak value of current prior to NDR is reduced, leading to a reduction in the predicted peak-to-valley ratio. An approach is presented to include space-charge effects, and a recently fabricated GaAs-Alx Gal _ x As structure is analyzed, to underscore the importance of a self-consistent electrostatic potential in theoretical calculations.

Recombination-Current Suppression In Gaas P-N Junctions Grown On Algaas Buffer Layers By Molecular-Beam Epitaxy, D. P. Rancour, M. R. Melloch, R. F. Pierret, Mark S. Lundstrom, M. E. Klausmeier-Brown, C. S. Kyono

Department of Electrical and Computer Engineering Faculty Publications

n+pp+GaAs and n+pP+ GaAs/GaAs/Al0.3Ga0.7As mesa diodes have been fabricated from films grown by molecular‐beam epitaxy. The diodes made from films employing an AlGaAs buffer layer show marked improvements (a factor of 5 reduction) in recombination current densities. Deep level transient spectroscopy measurements moreover indicate that deep level concentrations are reduced by the AlGaAs buffer.