Engineering Commons^™

The Fracture Of Ice On Scales Large And Small: Arctic Leads And Wing Cracks, E. M. Schulson, W. D. Hibler

Dartmouth Scholarship

From observations and calculations of crack patterns in ice, it is suggested that a similar mechanism may account for cracking over a wide range of scales.

General Phase Modulation Method For Stored Waveform Inverse Fourier Transform Excitation For Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Shenheng Guan, Patrick R. Jones

Pacific Patents

A method for reducing the dynamic range of FT-ICR signal generated by the SWIFT technique includes the step of time shifting wave packets corresponding to segments of the Fourier spectral magnitude function to prevent coherent summing of the various frequency components of the excitation signal.

Apparatus And Method For Automatically Identifying Chemical Species Within A Plasma Reactor Environment, Richard N. Savage

Materials Engineering

A method and apparatus to control the plasma environment in a semiconductor or thin-film fabrication chamber. The apparatus and method include a means for measuring an optical emission spectrum of the chemical species in the plasma and a library containing a multiplicity of predefined spectral patterns. A processor automatically correlates the spectrum with the predefined spectral patterns in the library, and yields a correlation value for all the correlations. A subset of the predefined spectral patterns based upon the highest correlation values are selected and used to identify the chemical species and abundances thereof in the plasma. A comparator compares …

Visible Light Emission From Semiconducting Polymer Diodes, David Braun, A. J. Heeger

Electrical Engineering

We report visible light emission from Shottky diodes made from semiconducting polymers, confirming the discovery by the Cambridge group [Nature 347, 539 (1990)]. Our results demonstrate that light-emitting diodes can be fabricated by casting the polymer film from solution with no subsequent processing or heat treatment required. Electrical characterization reveals diode behavior with rectification ratios greater than 104. We propose that tunneling of electrons from the recitifying metal contact into the gap states of the positive polaron majority carriers dominates current flow and provides the mechanism for light emission.

Exploiting And/Or Parallelism In Prolog, Bankim Shah

Dissertations and Theses

Logic programming languages have generated increasing interest over the last few years. Logic programming languages like Prolog are being explored for different applications. Prolog is inherently parallel. Attempts are being made to utilize this inherent parallelism. There are two kinds of parallelism present in Prolog, OR parallelism and AND parallelism. OR parallelism is relatively easy to exploit while AND parallelism poses interesting issues. One of the main issues is dependencies between literals.

It is very important to use the AND parallelism available in the language structure as not exploiting it would result in a substantial loss of parallelism. Any system …

Measuring Thermostat And Air Conditioner Performance In Florida Homes, Florida Solar Energy Center, Hugh Henderson, Jr.

FSEC Energy Research Center®

This report summarizes the experimental results from 30 field tests in 23 Central Florida homes during the Summer of 1990. Detailed thermostat measurements were made at each site for a one to three day period. The purpose of this study was to determine how thermostats operate in actual buildings. This knowledge is necessary to understand the part load performance of air conditioners (ACs).

Effects Of Plan Asymmetry In Inelastic Seismic Response Of One-Story Systems, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The effects of plan asymmetry on the earthquake response of one-story systems are identified by comparing the dynamic response of an asymmetric-plan system and the corresponding symmetric-plan system for a wide range of system parameters—uncoupled lateral vibration period, uncoupled torsional-to-lateral frequency ratio, stiffness eccentricity, and yield factor. Elastic as well as inelastic systems are studied. For the latter, two values of the strength eccentricity are considered: equal to the stiffness eccentricity and zero; the latter is representative of code-designed buildings. Based on the response results for a wide range of system parameters, this paper identifies how the structural response is …

Acuta Enews May 1991, Vol. 20, No. 5

ACUTA Newsletters

In This Issue

Golf outing set for St. Louis

Network ties islands together

Reorganization at Chicago

Recycling phone books

Party Line

Call for nominations

Hydraulic Roughness Coefficients As Affected By Random Roughness, John E. Gilley, S. C. Finkner

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Random roughness parameters are used to characterize surface microrelief. In this study, random roughness was determined following six selected tillage operations. Random roughness measurements agreed closely with values reported in the literature.

Surface runoff on upland areas is analyzed using hydraulic roughness coefficients. Darcy-Weisbach and Manning hydraulic roughness coefficients were identified in this investigation on each soil surface where random roughness values were determined. Hydraulic roughness coefficients were obtained from measurements of discharge rat巳and flow velocity.

The experimental data were used to derive regression relationships which related Darcy-Weisbach and Manning hydraulic roughness coefficients to random roughness and Reynolds number. Random …

Calculating Farm Machinery Field Capacities, J. N. Hancock, Larry D. Swetnam, F. J. Benson

Agricultural Engineering Extension Publications

Calculating field capacities is just part of the overall concept of farm machinery management. Successful farm machinery management does not guarantee a profit, but machinery costs are a major expense and they must be monitored and managed. Therefore, the efficient use of farm machinery starts with determining working capacity in conjunction with the amount of work to be accomplished in a timely manner.

The Calendar - May 1991, Nova University

The Calendar

No abstract provided.

Cost Effective Maintenance Contracting -- A Literature Review, Bobby W. Meade, David Q. Hunsucker

Kentucky Transportation Center Research Report

Faced with ever increasing maintenance needs and constrained resources for meeting those needs, government agencies are searching for the most cost effective means of conducting highway maintenance. One alternative being used is contracting highway maintenance to private agencies. This report includes the findings of a literature search of articles pertaining to contract maintenance.

Review of the articles acquired in the literature search indicates that contract maintenance is increasing in usage and is a cost effective alternative.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, May 1991, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A six page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Evaluation Of Highway Geometrics Related To Large Trucks, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

One objective of this study was to determine the extent of highway safety and geometric problems associated with larger trucks using Kentucky's highways. The accident analysis involved both a general analysis of all truck accidents statewide as well as the identification of specific high-accident locations. A second objective was to identify criteria which can be used in identifying roadway sections that cannot safely accommodate large trucks.

The accident analysis given can be used to investigate locations which have a high number of truck accidents. The general accident statistics related to trucks can be used in the investigation of the high-accident …

Investigation Of Threaded Code, K. E. Graves, Paul D. Stigall

Computer Science Technical Reports

The design, structure and performance of threaded code are examined through the development of a threaded. code classification system and the modification of the threaded code technique used by a Forth programming language implementation. The classification system distinguishes threaded code designs by three elements: the interpreter, the code structure and the reference method to routines. Threaded code designs from the literature are described using the new classification scheme. The threaded code techniques of variable depth indirect threaded code and token indirect token threaded code are examined in a Forth programming language system on an INMOS IMS T222 transputer. Their design …

Applying Formal Verification Methods To Pure Rule-Based Programs, Rose F. Gamble, Gruia-Catalin Roman, William E. Ball, H. Conrad Cunningham

All Computer Science and Engineering Research

Reliability, defined as the guarantee that a program satisfies its specifications, is an important aspect of many applications for which rule-based expert systems are suited. Verification refer to the process used to determine the reliability of the rule-based program. Because past approaches to verification are informal, guarantees of reliability cannot fully be made without severely restricting the system. On the other hand, by constructing formal specifications for a program and showing the program satisfies those specifications, guarantees of reliability can be made. This paper presents an assertional approach to the verification of rule-based programs. The proof logical needed for verification …

Investigation Of Threaded Code, K. E. Graves, Paul D. Stigall

Computer Science Technical Reports

The design, structure and performance of threaded code are examined through the development of a threaded. code classification system and the modification of the threaded code technique used by a Forth programming language implementation. The classification system distinguishes threaded code designs by three elements: the interpreter, the code structure and the reference method to routines. Threaded code designs from the literature are described using the new classification scheme. The threaded code techniques of variable depth indirect threaded code and token indirect token threaded code are examined in a Forth programming language system on an INMOS IMS T222 transputer. Their design …

Bs News

Building Services Engineering

No abstract provided.

Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites

Electronic Theses and Dissertations

Glycerophospholipids of mammalian cells exist as chemically diverse structures with various fatty acids at the sn-1 and sn-2 positions. Arachidonic acid, a polyunsaturated fatty acid, which may be converted to biologically active eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, is found predominantly in the sn-2 position of glycerophospholipids. The purpose of this study was to examine, at the level of the individual molecular species, the incorporation of arachidonate into phospholipids and its release from phospholipids during stimulation. In this way, the specificity of the enzymes controlling arachidonate metabolism could be examined in order to clarify the processes that control the …

Field-Equation Approximations And The Dynamics Of High-Gain Lasers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Semiclassical models for laser-dynamics studies typically incorporate a derivative approximation that reduces the second-order wave equation for the electric field to a first-order equation. It is shown here that this approximation and further frequency approximations are not necessary and may lead to significant errors for some high-gain laser systems. A more exact analysis also reveals a partial decoupling of the electric and magnetic fields that occurs with fast transient phenomena. These ideas are illustrated in terms of well-known dynamical effects.

Effects Of Alternative Sprinkler Irrigation Parameters On Pesticide Movement, Ahmad Yar Ranjha, Richard C. Peralta, Robert W. Hill, Antonio Maria Requena, Howard M. Deer, Majid Ehteshami

Civil and Environmental Engineering Faculty Publications

The relative reduction in potential ground-water contamination due to pesticides at several sites in Utah was determined by comparing alternative irrigation system designs, water management practices and pesticides. Alternative sprinkler irrigation distribution coefficients were used to estimate infiltration depths. The movement of pesticides through soils following sprinkler irrigations was simulated with one-dimensional model. Pesticide contamination of ground water can be reduced by careful selection of pesticides, properly designed irrigation systems and improved water management techniques. Procedures for selecting an appropriate sprinkler design and pesticide are presented.

Estimation Of Crop Evapotranspiration By Means Of The Penman-Monteith Equation, Paul J. Vanderkimpen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study evaluated the potential of using simple, semi-empirical resistance models for the direct estimation of crop evapotranspiration as an alternative to the traditional approach involving a reference equation and a crop coefficient. It consisted of three major parts.

The first part originally aimed at the development of simple expressions for the aerodynamic and surface resistance terms in the Penman-Monteith equation. This goal could not be achieved because of two reasons: First, the determination of aerodynamic resistance was rendered impossible because of problems with the measurements, and, secondly, the values of surface resistance, back-calculated from the Penman-Monteith equation, turned out …

Composition And Method For Radiation Synovectomy Of Arthritic Joints, D. E. Day, Gary J. Ehrhardt

Materials Science and Engineering Faculty Research & Creative Works

Radioactive microspheres for radiation synovectomy of arthritic joints in a mammal comprises a biodegradable glass material and a beta radiation emitting radioisotope chemically dissolved in and distributed substantially uniformly throughout the glass material. The biodegradable glass material may be lithium silicate, lithium aluminosilicate, lithium aluminoborate, lithium germa- nate, lithium aluminogermanate, potassium silicate, potassium aluminosilicate, potassium aluminoborate, potassium germanate or potassium aluminogermanate and the beta radiation emitting radioisotope may be samarium-153, holmium-166, erbium-169, dysprosium-165, rhenium-186, rhenium-188 or yttrium-90. Method for preparing such microspheres and for carrying out radiation synovectomy of arthritic joints utilizing such microspheres are also disclosed.

Radioactive Glass Microspheres, D. E. Day, Gary J. Ehrhardt

Materials Science and Engineering Faculty Research & Creative Works

A radioactive microsphere for radiation therapy of a mammal comprising a biologically compatible glass material containing a beta or gamma emitting radioisotope distributed substantially uniformly throughout the glass. Advantageously, the radioisotope is produced by irradiation of the microsphere.

Hybrid Wafer Scale Microcircuit Integration -- [ 5008213 ], Edward S. Kolesar Jr.

AFIT Patents

A wafer scale integration arrangement wherein integrated circuit die of varying size, fabrication processes, and function are commonly mounted in the same host wafer using a filled epoxy material of special characteristics. The mounting epoxy material also serves as a substrate for the die interconnecting conductors in regions adjacent the mounted die. The described assembly also includes a newly available photosensitive polyimide material as a planarization and passivation covering for the die and hose wafer and as a mounting surface for an interconnecting metal conductor array. Multiple levels of interconnection metal. Fabrication processes for the die to host wafer attachment …

The Thermal Response Of Downhill Skis, S. C. Colbeck, G. C. Warren

Dartmouth Scholarship

No abstract provided.

Optical And Magneto-Optical Characterization Of Tbfeco Thin Films In Trilayer Structures, William A. Mcgahan, Ping He, Liang-Yao Chen, Sal Bonafede, John A. Woollam, F. Sequeda, T. Mcdaniel, H. Do

Department of Electrical and Computer Engineering: Faculty Publications

A series of TbFeCo films ranging in thickness from 100 to 800 Å have been deposited in trilayer structures on silicon wafer substrates, with S₃N₄ being employed as the dielectric material. These films have been characterized both optically and magneto-optically by variable angle of incidence spectroscopic ellipsometry, normal angle of incidence) reflectometry, and normal angle of incidence Kerr spectroscopy. From these measurements, the optical constants n and k have been determined for the TbFeCo films, as well as the magneto-optical constants Ql and Q2. Results are presented that demonstrate the lack of dependence of these …

Monitored Energy Use Characteristics Of A Florida Residence: Demonstration Of A Research Monitoring Protocol, Data Acquisition System And Associated Analysis Methods, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

This report summarizes the first four months of data collection on the author's home in Cocoa Beach, Florida. This project was designed to develop and test a residential monitoring protocol for a cooling dominated climate. The project has demonstrated that useful research results can be obtained from the detailed monitoring of a single occupied residential home.

Vertical And Angular Motion Of A Wing Model In Steady Flow: A Physical And Numerical Experimental Study, Andrew P. Johnston

Opportunities for Undergraduate Research Experience Program (OURE)

The dynamic response of a rigid wing in steady flow mounted on translational and rotational elastic supports is investigated. This study presents both a numerical and a physical experimental arrangement that can be employed to investigate the effect of a wide range of parameters on the response of the wing subjected to steady flow. An interactive computer program, which utilizes the fourth order Runge-Kutta integration scheme to solve the governing differential equations, is discussed. The program output allows for quick visualization of the change in response due to parameter changes. An experimental arrangement that utilizes the new 18" x 18" …

Study Of Joint Flexibility In Steel Frame Structures, Randy R. Frank

Opportunities for Undergraduate Research Experience Program (OURE)

Joint flexibility plays an important role in the distribution of strains and displacements in the frame structures of buildings, towers, automobiles, etc.. The objective of this project is to study the effect of flexibility (or rigidity) of two simple mechanical joints in frame structures on the stress and displacement distributions, using both experimental and analytical methods. Three welded and three bolted samples were fabricated using A-36 low carbon steel in a two column and horizontal crossmember (table) arrangement. This arrangement allows for both shear forces and axial forces in the joint. From a three element rectangular rosette strain gage attached …