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Articles 66421 - 66450 of 75322

Full-Text Articles in Engineering

Effect Of Culture Conditions, Donor Age, And Injection Site On In Vitro Development Of Dna Microinjected Porcine Zygotes, M A. Hajdu, J W. Knight, R S. Cansecot, R L. Krisher, William H. Velander, R E. Pearson, F C. Gwazdauskas May 1994

Effect Of Culture Conditions, Donor Age, And Injection Site On In Vitro Development Of Dna Microinjected Porcine Zygotes, M A. Hajdu, J W. Knight, R S. Cansecot, R L. Krisher, William H. Velander, R E. Pearson, F C. Gwazdauskas

Papers in Biotechnology

A series of experiments evaluated development of porcine zygotes microinjected with DNA in three culture media and two incubation temperatures, from postpubertal and prepubertal donors, and between zygotes injected with DNA into the pronucleus and the cytoplasm. Zygotes recovered from 36 postpubertal gilts in Exp. 1 were injected and cultured in modified NCSU-23, modified NCSU-37, and CZB media at 37°C or 39°C for 7 d. In Exp. 2, zygotes were collected from postpubertal or prepubertal gilts, microinjected with DNA, and cultured in modified NCSU-23. In Exp. 3 superovulated prepubertal gilts had DNA injected into the cytoplasm or pronucleus of zygotes. …


Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski May 1994

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski

Mechanical Engineering Faculty Research

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, …


The Effects Of Channel Curvature And Protusion Height On Nucleate Boiling And The Critical Heat Flux Of A Simulated Electronic Chip, John E. Leland May 1994

The Effects Of Channel Curvature And Protusion Height On Nucleate Boiling And The Critical Heat Flux Of A Simulated Electronic Chip, John E. Leland

Office for Research Publications and Presentations

The quest for higher power yet smaller electronics has given rise to the need for very effective cooling of these electronics. Because one of the foremost problems in electronics cooling is achieving high heat flux cooling within small packages while expending minimal pumping power, one focus of this study was to investigate the effects of channel curvature on the CHF. Experimental data were obtained for flow rates of 1-7 m/s, subcoolings of 5-35"C, and radii of curvature of 25.4 and 50.8 mm. A correlation was obtained for these data which provided an excellent fit.

One condition that has been ignored …


Non‐Rayleigh Statistics Of Ultrasonic Backscattered Echo From Tissues, V. Manjo Narayanan, Robert C. Molthen, P. M. Shankar, J. M. Reid May 1994

Non‐Rayleigh Statistics Of Ultrasonic Backscattered Echo From Tissues, V. Manjo Narayanan, Robert C. Molthen, P. M. Shankar, J. M. Reid

Biomedical Engineering Faculty Research and Publications

The envelope of the backscattered signal from tissues can exhibit non‐Rayleigh statistics if the number density of scatterers is small or if the variations in the scattering cross sections are random. The K distribution which has been used extensively in radar, is introduced to model this non‐Rayleigh behavior. The generalized K distribution is extremely useful since it encompasses a wide range of distributions such as Rayleigh, Lognormal, and Rician. Computer simulations were conducted using a simple one‐dimensional discrete scatteringmodel to investigate the properties of the echo envelope. In addition to cases of low number densities, significant departures from Rayleigh statistics …


Electrical And Crystallographic Characterization Of Cdte Grown By The Vapor Transport Method, Jack L. Boone, Gene Cantwell, W. C. Harsch, J. E. Thomas, B. A. Foreman May 1994

Electrical And Crystallographic Characterization Of Cdte Grown By The Vapor Transport Method, Jack L. Boone, Gene Cantwell, W. C. Harsch, J. E. Thomas, B. A. Foreman

Electrical and Computer Engineering Faculty Research & Creative Works

Crystallographic and electrical characterization techniques were performed on CdTe single crystal samples grown by the sublimation and physical vapor transport (SPVT) technique. The SPVT growth process described here has resulted in the routine growth of 45-50 mm diameter, 250-300 g boules of single crystal CdTe. As-grown material is p-type in the 5-10 ω cm range. Etch pit densities (EPD) are nominally 7x104 cm-2 along the [111] growth direction and 3x104 cm-2 along the [111] direction. X-ray full width at half maximum (FWHM) on recent samples is 8.6 arc sec compared to 8.5 arc sec theoretical. The as-grown p-type material displays …


A User-Level Process Package For Concurrent Computing, Ravi Konuru, Steve Otto, Jonathan Walpole, Robert Prouty, Jeremy Casas May 1994

A User-Level Process Package For Concurrent Computing, Ravi Konuru, Steve Otto, Jonathan Walpole, Robert Prouty, Jeremy Casas

Computer Science Faculty Publications and Presentations

A lightweight user-level process(ULP) package for parallel computing is described. Each ULP has its own register context, stack, data and heap space and communication with other ULPs is performed using locally synchronous, location transparent, message passing primitives. The aim of the package is to provide support for lightweight over-decomposition, optimized local communication and transparent dynamic migration. The package supports a subset of the Parallel Virtual Machine(PVM) interface[Sun90).


Fluttering Fountains: Stability Criteria, Lee W. Casperson May 1994

Fluttering Fountains: Stability Criteria, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The fluttering oscillations that have long been seen in falling sheets of water have recently been subjected to detailed theoretical analysis. In this study stability criteria for these oscillations are derived and discussed. These criteria provide insight into the physical mechanisms of the instability and may be employed in the design of fluttering waterfall systems.


The Reduction Of Dielectric Constant By Shaped Porosity, Weiping Cai May 1994

The Reduction Of Dielectric Constant By Shaped Porosity, Weiping Cai

Opportunities for Undergraduate Research Experience Program (OURE)

In multi-layer circuits, the reduction of the dielectric constant in substrate materials is becoming increasingly important, as the heat emission of the circuits increases with an increasing number of layers. One way to achieve a lower dielectric constant is to create porosity in the material. In this project, two types of substrate samples were made with coin-shaped porosity. One had holes of 8.0mm in diameter, and the other had holes of 2.5mm in diameter. The total vacuum area was 250mm2, or 7.7% of the total area, in either case. It was hoped to discover a relationship between aspect …


Fixed Site Facilitated Transport Of Oxygen And Nitrogen Through Plasma Polymer Films, Chad Dunnegan May 1994

Fixed Site Facilitated Transport Of Oxygen And Nitrogen Through Plasma Polymer Films, Chad Dunnegan

Opportunities for Undergraduate Research Experience Program (OURE)

A method of preparing plasma polymer films, in which metal chelate molecules are incorporated, is briefly outlined. The chemical reactivity of metal chelate molecules is preserved so that they may ”facilitate” the transport of oxygen molecules through the membrane. The method for testing permeability of the films is presented and results are analyzed with respect to the dual mode sorption model, applied to fixed site facilitated transport.


Skin Effects Due To Perforations -- A Study Of Analysis Techniques, Jon Michael Gibbs May 1994

Skin Effects Due To Perforations -- A Study Of Analysis Techniques, Jon Michael Gibbs

Opportunities for Undergraduate Research Experience Program (OURE)

Until 1991, two methods could be used to evaluate the skin effect due to perforations, the Brons and Marting Method and the Harris Method. Due to the simplicity of the technique, the Brons and Marting Method has been the preferred method of use in the petroleum industry. However, with the recent development of a third technique to evaluate the skin effect due to perforations, the need has arisen to evaluate each of these techniques to determine which method is the most accurate under given conditions. This paper reviews and compares each of the three methods for evaluating the perforations skin. …


Solubility Of Red Phosphorous In Lead, Sean E. Walker May 1994

Solubility Of Red Phosphorous In Lead, Sean E. Walker

Opportunities for Undergraduate Research Experience Program (OURE)

The determination of the solubility of red phosphorus in lead can be used to produce a plot of the solubility with respect to temperature and pressure. The plot is produced with experimental data, activity determination from present thermodynamic data, and compilation of the two sets of data into the semi-regular solution format. A lead-phosphorus solubility diagram is necessary to determine the amount phosphorus that will be absorbed by lead and will remain unreacted in a given process.


The Development Of Equipment Specification Form From The Pdxi Data Models, Justin M. Juengel May 1994

The Development Of Equipment Specification Form From The Pdxi Data Models, Justin M. Juengel

Opportunities for Undergraduate Research Experience Program (OURE)

The project has culminated in the development of a simplistic working model, based upon the existing data model created by the Process Data Exchange Institute (PDXI). This data model is depicted in Volume 1 of the deliverables for the PDXI Data File Interchange Format Project. The working model, based in part on the Planning Level Model and the Heat Transfer Model [1] of the overall data model, was then used to create an equipment specification form (Fig 1) for a heat exchanger, partially utilizing the standards set forth by the Tubular Exchanger Manufacturers Association (TEMA).


Solvent Recovery For An Extraction Process, Denise C. Ratcliff May 1994

Solvent Recovery For An Extraction Process, Denise C. Ratcliff

Opportunities for Undergraduate Research Experience Program (OURE)

The solvent recovery project involves the recovery of a valuable solute, acetic acid, from a spend solvent stream generated in a laboratory extraction experiment. The majority of this project’s efforts center on the simulation of a ten-stage distillation column that will recover the acid. These simulation results will then be used to specify the ancillary process equipment needed for this distillation process.


Evaluation Of The Edge Strength Of Architectural Glass, Kevin L. Alexander May 1994

Evaluation Of The Edge Strength Of Architectural Glass, Kevin L. Alexander

Opportunities for Undergraduate Research Experience Program (OURE)

A mechanical device to test the edge strength of glass was developed in a previous study and was to be modified for more accurate results in this study. The mechanical apparatus allows for a load to be applied and directed along one diagonal of a glass beam making the other diagonal the neutral axis. This allows only one edge to be in tension where the failure is desired.

This study evaluated the scored edge lines and the other edge lines of annealed glass which was cut by an experienced glass cutter with a steel scoring wheel, and a carbide scoring …


Automation Of Process Data Management, Stephen C. Chadwick May 1994

Automation Of Process Data Management, Stephen C. Chadwick

Opportunities for Undergraduate Research Experience Program (OURE)

The project goal is to create an automated system for managing data that describes a chemical process. The data is both graphical, such as piping and instrumentation diagrams, and numerical, such as pipe schedule and diameter. AutoLisp and C++ programs were developed and tested to simplify the creation of the automated system.


The Affects Of Butyl Acetate And Acetone On Plexiglass, Tracy E. Downs May 1994

The Affects Of Butyl Acetate And Acetone On Plexiglass, Tracy E. Downs

Opportunities for Undergraduate Research Experience Program (OURE)

The actions that solvents take on polymers was the focus of the summer 1993 research. There were two goals: one was to measure the distances between the cracks that formed in the plexiglass and two was to determine the time of arrival of the cracks. Two solvents, butyl acetate and acetone were used to generate data on polymethyl methacrylate (PMNA/Plexiglass).

The measurement of the time of arrival of a crack was another goal. This quantity is related to the growth of the fractures. This was difficult since only a localized portion of the plexiglass sample could be viewed.


Automation Of The Electrostatic Aerosol Classifier And The Continuous Flow Cloud Diffusion Chamber, Daron W. Dryer May 1994

Automation Of The Electrostatic Aerosol Classifier And The Continuous Flow Cloud Diffusion Chamber, Daron W. Dryer

Opportunities for Undergraduate Research Experience Program (OURE)

Analyzing cloud condensation nuclei through the use of a Continuous Flow Thermal Diffusion Cloud Chamber (CFD) and an Electrostatic Aerosol Classifier (EAC) can be very time consuming. An alternative to manually monitoring these devices is to automate the equipment, thus freeing personnel for other research as well increasing CCN data collection.

Automation of the EAC will be carried out by digital command through the use of a Quick Basic program. This program will be run from an IBM personal computer outfitted with a digital input/output board.

RS-485 Standard will also be incorporated into the Quick Basic program in order to …


Improved Techniques For Manufacturing Layered Laminate Composite Materials, Michael D. Grabber May 1994

Improved Techniques For Manufacturing Layered Laminate Composite Materials, Michael D. Grabber

Opportunities for Undergraduate Research Experience Program (OURE)

An increasingly important class of engineering materials are known as fiber reinforced composite materials. They offer outstanding mechanical properties, unique flexibility in design, and ease of fabrication. Because of this, fiber reinforced composites are being found more and more in such diverse applications as aircraft, space vehicles, automobiles, sporting goods, and appliances.

The main objective of this research project was to develop a procedure for which high quality composite plates could be manufactured. The procedure needed to be able to accommodate materials of various thicknesses as well as various sizes. We also wanted the procedure to be versatile enough to …


An Extension Of Pdxi Data Models To Include Process Control Data, Joseph D. Graber May 1994

An Extension Of Pdxi Data Models To Include Process Control Data, Joseph D. Graber

Opportunities for Undergraduate Research Experience Program (OURE)

The results described herein have culminated into the creation of an object model which extends an existing engineering data model to include process control data. The existing data model is described in Volume I of the deliverables for the Process Data Exchange Institute (PDXI) Data File Interchange Format Project. This object model was created using the OMTooP software package on Sun Stations in the Intelligent Systems Center(ISC) of the University of Missouri--Rolla (UMR). It expands on the classes of signal port, control element, and control system.


Forced Convective Diffusion And Interphase Heat And Mass Transfer: Computations Of Radial Functions, Temperature And Concentration Fields, And Presentation Of Local And Average Nusselt And Sherwood Numbers, Stephen Myers, X B. Reed Jr., N. Y. Shah, A. E. Penn May 1994

Forced Convective Diffusion And Interphase Heat And Mass Transfer: Computations Of Radial Functions, Temperature And Concentration Fields, And Presentation Of Local And Average Nusselt And Sherwood Numbers, Stephen Myers, X B. Reed Jr., N. Y. Shah, A. E. Penn

Opportunities for Undergraduate Research Experience Program (OURE)

Theoretical calculations have been carried out for forced convective transport for uniform streaming and uniaxial and biaxial extensional axisymmetric flows past single spheres. Homogeneous and heterogeneous chemical reactions, both of first and of second order have also been or are presently being treated. Orthogonality and other properties of Legendre functions have been used, together with introduction of an eigenfunction expansion, to reduce the mathematical description from a partial differential equation with variable coefficients, which is nonlinear for homogeneous second order chemical reactions, to a system of coupled ordinary differential equations for the radial modes. The numerical solutions of the latter …


A Computer Graphic Teaching Aid For The Synthesis Of Four-Bar Linkages, Sew K. Woon May 1994

A Computer Graphic Teaching Aid For The Synthesis Of Four-Bar Linkages, Sew K. Woon

Opportunities for Undergraduate Research Experience Program (OURE)

This project involves developing software for the use as a teaching tool in the classroom. The "four-bar linkage mechanism", often used in kinematic movement, is the main subject

The software provides a working environment to perform a graphical synthesis of a four- bar linkage to move one of the links through three specified positions in the plane. The construction process is facilitated by the built in kinematic intelligence so that the student can quickly and easily visualize the process. The construction lines are dynamically updated as the free parameters in the design are modified. This is particularly beneficial because it …


Institutional Issues Related To The Application Of Intelligent Vehicle Highway Systems Technologies To Commercial Vehicle Operations In Indiana, James G. Kavalaris, Kumares C. Sinha May 1994

Institutional Issues Related To The Application Of Intelligent Vehicle Highway Systems Technologies To Commercial Vehicle Operations In Indiana, James G. Kavalaris, Kumares C. Sinha

JTRP Technical Reports

The study focused on potential barriers and opportunities to implementing Intelligent Vehicle-Highway System (IVHS) technologies to Commercial Vehicle Operations (CVO) in Indiana. Specific concepts included: (1) Automatic payment of tolls while driving at mainline speeds; (2) Pre-Clearance of vehicles and drivers past weigh stations; (3) "One-Stop-Shopping" for licenses, registrations, and permits; and (4) Transparent state borders. The study reviewed existing laws and policies applying to commercial vehicles operating in Indiana; prepared an inventory of the agencies responsible, their existing procedures, their physical facilities, and their human resources used to implement these regulations; itemized present impediments preventing the implementation of IVHS-CVO …


Behavior Of Web Elements With Openings Subjected To Bending, Shear And The Combination Of Bending And Shear, Ming-Yang Shan, Roger A. Laboube, Wei-Wen Yu May 1994

Behavior Of Web Elements With Openings Subjected To Bending, Shear And The Combination Of Bending And Shear, Ming-Yang Shan, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE The current design criteria for cold-formed steel members published by the American Iron and Steel Institute (1986,1991) do not provide sufficient information for the design of web elements with openings. The primary objective of this investigation was to study the structural behavior of cold-formed steel C-sections with web openings. This study deals with the structural behavior of beam webs subjected to bending moment, shear force and combined bending moment and shear force. This report presents a summary of experimental study and findings of analytical results. The test results indicate that the current AISI Specification does not account for the …


Constraint Objects, Divesh Srivastava, Raghu Ramakrishnan, Peter Revesz May 1994

Constraint Objects, Divesh Srivastava, Raghu Ramakrishnan, Peter Revesz

School of Computing: Conference and Workshop Papers

We describe the Constraint Object Data Model (CODM), which enhances an object-based data model with existential constraints to naturally represent partially specified information. We present the Constraint Object Query Language (COQL), a declarative, rule-based query language that can be used to infer relationships about and monotonically refine information represented in the CODM. COQL has a model-theoretic and an equivalent fixed-point semantics, based on the notions of constraint entailment and "proofs in all possible worlds." We also provide a novel polynomial-time algorithm for quantifier elimination for set-order constraints, a restricted class of set constraints that uses membership of subset-equal.


Evaluation Of Kentucky’S Policy On Tourist Information Signs, Jerry G. Pigman May 1994

Evaluation Of Kentucky’S Policy On Tourist Information Signs, Jerry G. Pigman

Kentucky Transportation Center Research Report

As a result of recommendations made by the Governor's Task Force on Signage and Tourism, the Transportation Cabinet requested that an evaluation be made of Kentucky's policy on tourist information signs. Among the tasks undertaken were a review of the formula tor Parks, Historic, and Recreation Area signs, a survey of interstates and parkways to determine the extent of the constraints imposed by the limitation of one supplemental sign tor each interchange approach, and an investigation of the potential for application of Tourist Oriented Directional signs (TODS).

The opportunity tor increased tourism through improvements in signing and accessibility was evaluated. …


Summary Of Stress Evaluations Of Welded Steel Bridges On Coal-Haul Routes, Theodore Hopwood Ii, Keith J. Hogan, Christopher M. Oberst May 1994

Summary Of Stress Evaluations Of Welded Steel Bridges On Coal-Haul Routes, Theodore Hopwood Ii, Keith J. Hogan, Christopher M. Oberst

Kentucky Transportation Center Research Report

Stress analyses were performed on continuous girder welded steel bridges on extended weights coal-haul routes. The tests were intended to determine whether extended weight coal trucks pose fatigue problems to those bridges. Measurements were performed by strain gaging selected bridges subject to high coal transport tonnages. Stress measurements were conducted on fatigue-prone weld details or test sites where high tensile stresses were anticipated. Test sites on the bridges were instrumented with strain gages. Strains induced by routine traffic including coal trucks were monitored for periods of one to two weeks. Unattended monitoring of the variable amplitude strain data was performed …


Tensile And Bearing Capacities Of Bolted Connections, Jeffrey L. Carril, Roger A. Laboube, Wei-Wen Yu May 1994

Tensile And Bearing Capacities Of Bolted Connections, Jeffrey L. Carril, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE Experimental studies were preformed to investigate the tensile capacity, bearing capacity and the interaction of tension and bearing capacities of flat sheet cold-formed steel bolted connections. The effect of bolt hole deformation on the bearing capacity of bolted connections, was also investigated. In the experimental investigation, single shear flat sheet connections were investigated for single bolt and multiple bolt configurations. The intent of this investigation was to compare the current AISI and AISC Specifications for the nominal bearing and tensile capacities and to develop appropriate serviceability design criteria. A review and evaluation of past research on the tensile and …


Structural Behavior Of Perforated Web Elements Of Cold-Formed Steel Flexural Members Subjected To Web Crippling And A Combination Of Web Crippling And Bending, James E. Langan, Roger A. Laboube, Wei-Wen Yu May 1994

Structural Behavior Of Perforated Web Elements Of Cold-Formed Steel Flexural Members Subjected To Web Crippling And A Combination Of Web Crippling And Bending, James E. Langan, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE A study of structural behavior was conducted and design equations were developed that account for the degradation in web crippling capacity caused by web openings for single web cold-formed steel flexural members. The sections were subjected to a concentrated load applied to one flange. The load application satisfied the AISI definition for either End-One-Flange or Interior-One-Flange loading. The research findings enable the current design provisions for sections without web openings to be modified by a reduction factor equation to obtain the web crippling capacity for sections with web openings. The modified capacity is considered for the web crippling capacity …


High Resolution Liquid Crystal Phase Grating Formed By Fringing Fields From Interdigitated Electrodes, Gregory P. Nordin, M. Friends, J. M. Jarem, S. T. Kowel, J. H. Kulick, T. Leslie, R. G. Lindquist May 1994

High Resolution Liquid Crystal Phase Grating Formed By Fringing Fields From Interdigitated Electrodes, Gregory P. Nordin, M. Friends, J. M. Jarem, S. T. Kowel, J. H. Kulick, T. Leslie, R. G. Lindquist

Faculty Publications

We report the formation of thin anisotropic phase gratings in a nematic liquid-crystalline film by use of lateral (fringing) electric fields induced by transparent interdigitated electrodes. These gratings yield high diffraction efficiency (>30%) with a strong dependence on the readout beam incidence angle. In addition, the formation of a defect wall is observed that has a significant effect on the diffraction properties of the phase grating.


Plains Electric Members Service Area_04-29-1994, University Of New Mexico Bureau Of Business And Economic Research Apr 1994

Plains Electric Members Service Area_04-29-1994, University Of New Mexico Bureau Of Business And Economic Research

BBER Publications

This report presents historical and projected socioeconomic data for 19 New Mexico and two Arizona counties which comprise the service areas of the distribution cooperatives in the Plains Electric Generation and Transmission Cooperative, Inc., system.