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Articles 2881 - 2903 of 2903

Full-Text Articles in Engineering

Texture, Microstructure And Formability Of Aluminum Alloys, Xiang-Ming Cheng Jan 2001

Texture, Microstructure And Formability Of Aluminum Alloys, Xiang-Ming Cheng

University of Kentucky Doctoral Dissertations

Texture, microstructure and formability were studied in Direct Chill Cast (DC) and Strip Cast (SC) aluminum alloys with regard to crystallographic anisotropy, the Portevin-Le Chatelier effect and aging softening behavior. It was found that material properties change greatly with manufacturing processes (DC vs. SC) and chemical composition (3xxx vs. 5 xxx alloys). DC cast hot band materials are usually fully recrystallized and have strong softening textures while SC hot band materials have a rolling structure with strong deformation textures. Softening textures cause 90 earing while deformation textures result in 45 earing after deep drawing. During cold rolling, 90 earing in …


History, Religion And Meaning: American Reflections On The Holocuast And Israel, Jules Simon Jan 2000

History, Religion And Meaning: American Reflections On The Holocuast And Israel, Jules Simon

Departmental Papers (Philosophy)

No abstract provided.


Seasonal And Spatial Variation Of Subgrade Response, Mustaque Hossain, Stefan Romanoschi, Andrew J. Gisi Jan 2000

Seasonal And Spatial Variation Of Subgrade Response, Mustaque Hossain, Stefan Romanoschi, Andrew J. Gisi

Civil Engineering Faculty Publications - Archive

Temperature, subgrade moisture content, and Falling Weight Defleetometer (FWD)-deflection data were collected monthly on four asphalt pavement test sections in Kansas for a year. The subgrade moduli were baekealeulated using the elastic layer theory. It was found that for almost all sites, the monthly variation in subgrade moisture content was not very significant over the seasons. The patterns of subgrade response, in terms of subgrade moduli versus time, simulated sine-shaped forms signifying a possible temperature effect. Higher variabilities across the site were associated with the extreme temperature conditions, usually very low or high average pavement temperatures. In all cases, the …


Bovine Follicular Dynamics, Oocyte Recovery,And Development Of Oocytes Microinjected With A Green Fluorescent Protein Construct, M S. Chauhan, S Nadir, T L. Bailey, A W. Pryor, S P. Butler, D R. Notter, William H. Velander, F C. Gwazdauskas Jan 1999

Bovine Follicular Dynamics, Oocyte Recovery,And Development Of Oocytes Microinjected With A Green Fluorescent Protein Construct, M S. Chauhan, S Nadir, T L. Bailey, A W. Pryor, S P. Butler, D R. Notter, William H. Velander, F C. Gwazdauskas

Papers in Biotechnology

The present study was carried out to 1) evaluate the viability of in vitro fertilized zygotes after microinjection of DNA, 2) assess the influence of oocyte quality upon the development rate of embryos when injected with DNA, and 3) determine the integration frequency of green fluorescent protein DNA into microinjected embryos. Oocytes were aspirated from ovaries of nine nonlactating Holsteins and were categorized into grades A, B, C, and D. At 16 h after in vitro fertilization, approximately half of the pronuclear stage presumptive zygotes were classified as having 1 pronucleus or 2 pronuclei, and they were microinjected with DNA …


A Strategy For Extending The House Of Quality To Obtain Preliminary Design Specifications, Patricia Brackin, Jonathon Colton Jan 1999

A Strategy For Extending The House Of Quality To Obtain Preliminary Design Specifications, Patricia Brackin, Jonathon Colton

Faculty Publications - Electrical and Computer Engineering

No abstract provided.


The First Full-Scale Accelerated Pavement Test In Louisiana: Development And Findings, J.B. Metcalf, Stefan Romanoschi, Y. Li, M. Rasoulian Jan 1999

The First Full-Scale Accelerated Pavement Test In Louisiana: Development And Findings, J.B. Metcalf, Stefan Romanoschi, Y. Li, M. Rasoulian

Civil Engineering Faculty Publications - Archive

The Pavement Research Facility in Port Allen, Louisiana houses the first full-scale accelerated pavement testing experiment in the state. The purpose of the first experiment was to evaluate the historically prevalent flexible crushed stone and in-place soil cement stabilized base construction in comparison to several alternative base construction materials and construction processes for pavements designed for a semi-tropical climate. Loading is provided by an Accelerated Loading Facility (ALF) machine, the second of its type in the United States. More than six million equivalent axle loads (ESALs) were applied to the nine test lanes. Performance of the pavement structures and materials …


Parameter Estimation Using Artificial Neural Network And Genetic Algorithm For Free-Product Migration And Recovery, J. Morshed, Jagath J. Kaluarachchi May 1998

Parameter Estimation Using Artificial Neural Network And Genetic Algorithm For Free-Product Migration And Recovery, J. Morshed, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Artificial neural network (ANN) is considered to be a universal function approximator, and genetic algorithm (GA) is considered to be a robust optimization technique. As such, ANN regression analysis and ANN-GA optimization techniques can be used to perform inverse groundwater modeling for parameter estimation. In this manuscript the applicability of these two techniques in solving an inverse problem related to a light-hydrocarbon-contaminated site is assessed. The critical parameters to be evaluated are grain-size distribution index α and saturated hydraulic conductivity of water Ksw, since these parameters control free-product volume predictions and flow. A set of published data corresponding to a …


Optimizing Separate Phase Light Hydrocarbon Recovery From Contaminated Unconfined Aquifers, G. S. Cooper, Richard C. Peralta, Jagath J. Kaluarachchi Apr 1998

Optimizing Separate Phase Light Hydrocarbon Recovery From Contaminated Unconfined Aquifers, G. S. Cooper, Richard C. Peralta, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

A modeling approach is presented that optimizes separate phase recovery of light non-aqueous phase liquids (LNAPL) for a single dual-extraction well in a homogeneous, isotropic unconfined aquifer. A simulation/regression/optimization (S/R/O) model is developed to predict, analyze, and optimize the oil recovery process. The approach combines detailed simulation, nonlinear regression, and optimization. The S/R/O model utilizes nonlinear regression equations describing system response to time-varying water pumping and oil skimming. Regression equations are developed for residual oil volume and free oil volume. The S/R/O model determines optimized time-varying (stepwise) pumping rates which minimize residual oil volume and maximize free oil recovery while …


Kinetics Of Transesterification Of Soybean Oil, Hossein Noureddini, D Zhu Mar 1997

Kinetics Of Transesterification Of Soybean Oil, Hossein Noureddini, D Zhu

Papers in Biomaterials

Transesterification of soybean oil with methanol was investigated. Three stepwise and reversible reacttons are believed to occur. The effect of variations in mixing intensity (Reynolds number = 3,100 to 12,400) and temperature (30 to 70'CJ on the rate oireaction were studied while the molar ratio of alcohol to triglycerol (6:l) and the concentration of catalyst (0.20 wt% based on soybean oil) were held constant. The variations in mixing intensity appear to effect the reaction parallel to the variations in temperature. A reaction mechanism consisting of an initial mass transfer-controlled region followed by a kinetically controlled region is proposed. The experimental …


Affinity Purification Of Biologically Active Andinactive Forms Of Recombinant Human Protein C Produced In Porcine Mammary Gland, Kevin E. Van Cott, Barry Williams Department Of Chemical Engineering,Virginia Tech University, Blacksburg, Va 24061, Usa, William H. Velander, Francis C. Gwazdauskas, Tim Lee Jerome Holland Laboratory, American Red Cross, Rockville, Md 20855, Usa, Henryk Lubon, William N. Drohan Sep 1996

Affinity Purification Of Biologically Active Andinactive Forms Of Recombinant Human Protein C Produced In Porcine Mammary Gland, Kevin E. Van Cott, Barry Williams Department Of Chemical Engineering,Virginia Tech University, Blacksburg, Va 24061, Usa, William H. Velander, Francis C. Gwazdauskas, Tim Lee Jerome Holland Laboratory, American Red Cross, Rockville, Md 20855, Usa, Henryk Lubon, William N. Drohan

Papers in Biotechnology

Recombinant human protein C (rhPC) secreted in the milk of transgenic pigs was studied. 'Ikansgenes having different regulatory elements of the murine milk protein, whey acidic protein, were used with cDNA and genomic human protein C (hPC) DNA sequences to obtain lower and higher expressing animals. The cDNA pigs had a range of expression of about 0.1-0.5 g/l milk. Two different genomic hPC pig lines have expressed 0.3 and 1-2 g/l, respectively. The rhPC was first purified at yields greater than 60 per cent using a monoclonal antibody (mAb) to the activation site on the heavy chain of hPC. Subsequent …


Effect Of Subsurface Heterogeneity On Free-Product Recovery From Unconfined Aquifers, Jagath J. Kaluarachchi Mar 1996

Effect Of Subsurface Heterogeneity On Free-Product Recovery From Unconfined Aquifers, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

Free-product record system designs for light-hydrocarbon-contaminated sites were investigated to evaluate the effects of subsurface heterogeneity using a vertically integrated three-phase flow model. The input stochastic variable of the areal flow analysis was the log-intrinsic permeability and it was generated using the Turning Band method. The results of a series of hypothetical field-scale simulations showed that subsurface heterogeneity has a substantial effect on free-product recovery predictions. As the heterogeneity increased, the recoverable oil volume decreased and the residual trapped oil volume increased. As the subsurface anisotropy increased, these effects together with free- and total-oil contaminated areas were further enhanced. The …


Critical Assessment Of The Operator-Splitting Technique In Solving The Advection-Dispersion-Reaction Equation: 1. First-Order Reaction, Jagath J. Kaluarachchi, Jahangir Morshed Dec 1995

Critical Assessment Of The Operator-Splitting Technique In Solving The Advection-Dispersion-Reaction Equation: 1. First-Order Reaction, Jagath J. Kaluarachchi, Jahangir Morshed

Civil and Environmental Engineering Faculty Publications

Operator-splitting technique (OST) is a common mathematical approach used in the solution of the advection-dispersion-reaction equation (ADRE), especially in the presence of biological decay, where the scales of transport and biological decay are far apart. The OST introduces a time-lag between the advection-dispersion and reaction stages by splitting the ADRE causing a breakdown of the physics of the problem, thus limiting its applicability. In this work, the applicability of the operator splitting technique is studied in parts. This first manuscript addresses the critical limitations of the operator-splitting technique as related to first-order decay, and the second manuscript extends the work …


Critical Assessment Of The Operator-Splitting Technique In Solving The Advection-Dispersion-Reaction Equation: 2. Monod Kinetics And Coupled Transport, Jahangir Morshed, Jagath J. Kaluarachchi Dec 1995

Critical Assessment Of The Operator-Splitting Technique In Solving The Advection-Dispersion-Reaction Equation: 2. Monod Kinetics And Coupled Transport, Jahangir Morshed, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

In the first manuscript of this two-part series, the behavior of the inherent time-lag error in the operator-splitting technique has been discussed. However, the discussion has been limited to the advection-dispersion-reaction equation with first-order kinetics. In this manuscript, the discussion is extended to address the applicability of the operator-splitting technique in solving the advection-dispersion-reaction equation with Monod kinetics. The discussion also considers the two-species coupled transport problem. The results of the analysis show that the behavior of the time-lag error causing a mass balance error is rather similar to those observed with first-order kinetics. The time-lag error directly depends on …


Design Factors For Improving The Efficiency Of Freeproduct Recovery Systems In Unconfined Aquifers, Jagath J. Kaluarachchi, R. Elliot Nov 1995

Design Factors For Improving The Efficiency Of Freeproduct Recovery Systems In Unconfined Aquifers, Jagath J. Kaluarachchi, R. Elliot

Civil and Environmental Engineering Faculty Publications

Free-product recovery system designs for light hydrocarbon recovery were investigated to evaluate the effects of multiple-stage pumping, delayed startup, and uncertainty of key residual oil saturation input data using a vertically integrated three-phase flow model, ARMOS. The results obtained from a single well recovery system subjected to a given well location and uniform soil properties suggested that multiple-stage water pumping can enhance the recovery and provide optimal design conditions if cost and recovery oil volume are the targets. However, if containment of the spill area with simultaneous recovery is the target, then single-stage pumping still provides the optimal design. Delayed …


Effects Of Time Of Deoxyribonucleic Acid Microinjection On Gene Detection And In Vitro Development Of Bovine Embryos, A.E T. Sparks, R S. Canseco, C G. Russell, J L. Johnson, H D. Moll, William H. Velander, Francis C. Gwazdauskas Mar 1994

Effects Of Time Of Deoxyribonucleic Acid Microinjection On Gene Detection And In Vitro Development Of Bovine Embryos, A.E T. Sparks, R S. Canseco, C G. Russell, J L. Johnson, H D. Moll, William H. Velander, Francis C. Gwazdauskas

Papers in Biotechnology

In vivo fertilized embryos were surgically collected from superovulated dairy cows to evaluate microinjection on embryo development and utilized the polymerase chain reaction technique for selection of transgenic embryos. Seventy-two percent of the embryos with visible pronuclei or nuclei were microinjected with DNA, and the remaining 28% served as uninjected controls. All embryos were cocultured with bovine oviductal epithelial cells. Mean final development scores of embryos within the same initial cell stage at collection were unaffected by microinjection. After 144 h of culture, 45% of the microinjected embryos developed to the morula or blastocyst stage. The transgene was detected in …


Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi Aug 1991

Comparing Simulated And Experimental Hysteretic Two-Phase Transient Fluid Flow Phenomena, R. J. Lenhard, J. C. Parker, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

A hysteretic model for two-phase permeability (k)-saturation (S)-pressure (P) relations is outlined that accounts for effects of nonwetting fluid entrapment. The model can be employed in unsaturated fluid flow computer codes to predict temporal and spatial fluid distributions. Consideration is given to hysteresis in S-P relations caused by contact angle, irregular pore geometry, and nonwetting fluid entrapment effects and to hysteresis in k-Srelations caused by nonwetting fluid entrapment effects. An air-water flow experiment is conducted with a 72-cm vertical soil column where the water table is fluctuated to generate scanning S-P paths. Water contents are measured via a gamma radiation …


A Numerical Model For Areal Migration Of Water And Light Hydrocarbon In Unconfined Aquifers, Jagath J. Kaluarachchi, J. C. Parker, R. J. Lenhard Mar 1990

A Numerical Model For Areal Migration Of Water And Light Hydrocarbon In Unconfined Aquifers, Jagath J. Kaluarachchi, J. C. Parker, R. J. Lenhard

Civil and Environmental Engineering Faculty Publications

A finite element model has been developed to simulate simultaneous flow of water and light hydrocarbon in an areal flow region of an unconfined aquifer for analyses of hydrocarbon spreading from subsurface leaks or spills and for use in design of free product recovery systems. Vertically integrated governing equations for water and oil flow are employed which assume local vertical equilibrium and negligible gas pressure gradients. Multiple water and free product recovery wells are handled as internal type-I boundary conditions by stipulating air-oil table elevation and free product height with corrections to convert grid averaged nodal heads to actual well …


Conformational Changes In An Epitope Localized To The Nh2-Terminal Region Of Protein C, Carolyn L. Orthener, Rapti D. Madurawe, William H. Velander, William N. Drohan, Frances D. Bettey, Dudley K. Strickhand Nov 1989

Conformational Changes In An Epitope Localized To The Nh2-Terminal Region Of Protein C, Carolyn L. Orthener, Rapti D. Madurawe, William H. Velander, William N. Drohan, Frances D. Bettey, Dudley K. Strickhand

Papers in Biotechnology

Murine monoclonal antibodies, developed following immunization with human protein C, were characterized for their ability tboin d antigen in thpe resence of either CaClz or excess EDTA. Three stablec lones were obtained which produced antiboditehsa t bound to protein C only itnh e presence of EDTA. Allt hree antibodies bound to the light choafi np rotein C on immunoblots and also bound to the homologous proteins factor X and prothrombin in solid-phase radioimmunoassays. One antibody, 7D7B10 was purified and studied further. The binding of 7D7B10 to human protein C was characterized bya KOo f 1.4 nM. In competition studies, it …


Finite Element Model Of Nitrogen Species Transformation And Transport In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker Nov 1988

Finite Element Model Of Nitrogen Species Transformation And Transport In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

A two-dimensional finite element model based on Galerkin's weighted residual approach and incorporating an upstream weighting technique was developed to predict the simultaneous transformation and transport of nitrogen species. The nitrogen cycle used in the analyses assumes first-order rate coefficients for nitrification, denitrification, immobilization and mineralization between the nitrogen species NH +4, NO -3, organic-N and denitrified fractions. The NO -3-N component in the soil solution was assumed to have negligible adsorption on exchange sites while adsorption of NH +4 was assumed to be represented by a Freundlich type nonlinear isotherm ( S = kdCp). The accuracy and validity of …


Effects Of Hysteresis With Air Entrapment On Water Flow In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker Oct 1987

Effects Of Hysteresis With Air Entrapment On Water Flow In The Unsaturated Zone, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

Effects of hysteresis with air entrapment on water content and head distributions, surface fluxes, and water balance components are investigated by finite element simulations of flow in one- and two-dimensional spatial domains. Results of one-dimensional analyses indicate that effects of hysteresis are markedly influenced by surface boundary conditions and to a lesser extent by initial conditions. Stipulation of flux-controlled boundary conditions results in minimal hysteretic effects, while potential-type boundary conditions produce substantial deviations between hysteretic and nonhysteretic simulations. The latter effects are attributable in large part to differences in surface conductivity associated with air entrapment. Predicted water content distributions for …


Finite Element Analysis Of Water Flow In Variably Saturated Soils, Jagath J. Kaluarachchi, J. C. Parker Apr 1987

Finite Element Analysis Of Water Flow In Variably Saturated Soils, Jagath J. Kaluarachchi, J. C. Parker

Civil and Environmental Engineering Faculty Publications

A two-dimensional Galerkin finite element model for water flow in variably saturated soil is presented. A fourth-order Runge-Kutta time integration method is employed which allows use of time steps at least 2 times greater than for a traditional finite difference approximation of time derivatives. For short total simulation times computer execution costs for the Runge-Kutta method are greater than for the finite difference approximation due to the start up cost of the Runge-Kutta method, but for longer simulation times the Runge-Kutta method requires considerably less computational effort even when automatic time-step adjustment is used with the finite difference procedure. A …


Infiltration Into Decomposed Granite Soils; Numerical Modeling, Applications And Some Laboratory Observations, A. W. Jayawardena, Jagath J. Kaluarachchi May 1986

Infiltration Into Decomposed Granite Soils; Numerical Modeling, Applications And Some Laboratory Observations, A. W. Jayawardena, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

This paper describes the outcome of a study on rain infiltration into decoposed granite which is one of the two main types of soils found in Hong Kong. It consists of the development and verification of a finite element based numerical model which has general applicability for flow through unsaturated porous media, application of the model for predicting moisture movement in an artificial slope made out of reconstituted decomposed granite and some laboratory observations including the estimation of soil hydraulic parameters.


Test 366: John Deere B, Nebraska Tractor Test Lab Jan 1941

Test 366: John Deere B, Nebraska Tractor Test Lab

Nebraska Tractor Tests

EXPLANATION OF TEST REPORT: John Deere B

TEST A: The manufacturer's representative operates the tractor for a minimum of 12 hours using light to heavy drawbar loads in each gear.

This serves as a period for limber up, general observation and adjustments. Adjustments that are permissible include valve tappet clearance, breaker ,point gap, spark plug gaps, clutch and others of a similar nature. No new parts or accessories can be installed without having mention made of it in the report. No data' are recorded during this preliminary run except the time that the engine is operated.

BELT HORSEPOWER TESTS

TEST …