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1991

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Articles 361 - 390 of 1363

Full-Text Articles in Engineering

A Microengineered Beam Diaphragm Structure For The High Performance Pressure Sensor, Alkesh Shah Aug 1991

A Microengineered Beam Diaphragm Structure For The High Performance Pressure Sensor, Alkesh Shah

Theses

The thesis details the design for a novel microengineered beam diaphragm structure for piezoresistive pressure sensor applications. The beam diaphragm structure is used as a pressure sensing device, within a Wheatstone bridge circuit. The single crystal silicon with [100] orientation is used for the beam diaphragm structure.

It has the advantages of high sensitivity(2.56 v/v/mm of Hg), good linearity(3Kpa to 1.4 Mpa) and overpressure protection with the help of the bosses. It's protection range is about 400 times the standard pressure range. The beam diaphragm structure has two rectangular bosses which are formed by anisotropic etching. Two pairs of diffused …


Electrical Characterization Of Preoxide Growth Fluorine Incorporated Thin Sio2 Films, Nilay J. Patel Aug 1991

Electrical Characterization Of Preoxide Growth Fluorine Incorporated Thin Sio2 Films, Nilay J. Patel

Theses

Analyses of electrical characterization, of thin SiO2 films grown on virgin and etched silicon surfaces, are presented here. The characterization techniques employed in these experiments are High Frequency Capacitance-Voltage (C-V), Capacitance-Time (C-T) & MOS Doping Profile and Static & Dynamic Current-Voltage (I-V) measurements. The structures, with areas ranging from 0.001-0.05 cm2, used in this study are Al/Poly/SiO2/Si/Al capacitors fabricated on virgin and C2F6 CHF3 + He plasma exposed n-Si substrates. In this experiment, we have studied the effect of sacrificial oxidation. In this step, the oxide is thermally grown on the …


Efficient Multiprocessor Scheduling Based On Genetic Algorithms, Hong Ren Aug 1991

Efficient Multiprocessor Scheduling Based On Genetic Algorithms, Hong Ren

Theses

The problem of multiprocessor scheduling can be stated as finding a schedule for a general task graph to be executed on a multiprocessor system so that the schedule length can be minimized. This scheduling problem in known to be NP-hard and methods based on heuristic search have been proposed to obtain optimal and sub-optimal solutions to the problem. Genetic algorithms have recently received much attention as robust stochastic searching algorithms for various optimization problems. In this thesis, we propose an efficient method based on genetic algorithms to solve the multiprocessor scheduling problem. The representation of the search node will be …


Magnetic Solvent Extraction, Jiann-Yang Hwang Aug 1991

Magnetic Solvent Extraction, Jiann-Yang Hwang

Michigan Tech Patents

Particles of a magnetic material coated with a hydro- phobic surfactant are dispersed in an organic solvent extractant to produce a magnetic solvent extractant which can be used in solvent extraction processes. Phase separation of an organic phase, carrying the component to be separated, from the aqueous phase can be accelerated by applying a magnetic field to the organic phase. After removal of the organic phase, a magnetic field can be applied to the aqueous phase to remove any residual organic phase and thereby enhance the degree of separation.


Method Of Making High Strength Articles From Forged Powder Steel Alloys, Alfred A. Hendrickson, Darrell W. Smith Aug 1991

Method Of Making High Strength Articles From Forged Powder Steel Alloys, Alfred A. Hendrickson, Darrell W. Smith

Michigan Tech Patents

High strength steel parts or articles are made from a powder alloy by compacting the powder into a preform, sintering the preform in a sintering furnace or the like under a highly-reducing atmosphere and at a temperature of at least 1150° C., cooling the preform, preheating the sintered preform in a highly-reducing atmosphere, such as an inert gas-based atmosphere containing hydrogen or pure hydrogen, to a temperature of at least 1000° C. and transferring the preheated preform to an impact forging device and impacting the preform at a peak averaging forging pressure of at least about 1000 MPa to obtain …


An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider Aug 1991

An Experimental Investigation Of The Finite Time Efficiency Of A Peltier Refrigeration Device, Thomas Schneider

Dissertations and Theses

Since the need of energy conservation has become more and more urgent in the past decades, there has been an increased interest in the study and development of more efficient energy conversion systems. One of the fields that have arisen from that endeavor is a branch of physics called Finite Time Thermodynamics (FIT). It may be said that FIT was initiated through the famous paper by Curzon and Ahlborn (1975) that established new bounds on the efficiency of a finite time Carnot heat engine. Before, the traditional treatments gave a fundamental upper limit on the efficiency of any heat engine. …


Composition And Method For Radiation Synovectomy Of Arthritic Joints, D. E. Day, Gary J. Ehrhardt Aug 1991

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

Materials Science and Engineering Faculty Research & Creative Works

A method for preparing nonradioactive microspheres adapted for radiation synovectomy of arthritic joints in a mammal involves forming the microspheres by doping a biodegradable glass material which may be lithium or potassium silicate, lithium or potassium aluminosilicate, lithium or potassium aluminoborate, lithium or potassium germanate or lithium or potassium alumino- germanate with an isotope which may be samarium, holmium, erbium, dysprosium, rhemium or yttrium so that the isotope is chemcially dissolved in and distributed uniformly throughout the glass material. The doped glass material is then treated with an acid wash to produce a thin layer on the surface thereof and …


Integrated Neural Network And Machine Vision Approach For Intelligent State Identification, Cihan H. Dagli, Timothy Andrew Bauer Aug 1991

Integrated Neural Network And Machine Vision Approach For Intelligent State Identification, Cihan H. Dagli, Timothy Andrew Bauer

Engineering Management and Systems Engineering Faculty Research & Creative Works

An interfacing of neural networks (NNs) and machine vision to provide the next state of a system given an image of the present state of the system is presented. This interfacing is applied to a loading operation. First, a NN is trained for part recognition under conditions of rotation, location, object distortion, and background noise given an image of the part. Then, a second NN, given the output of the first NN and an image of a pallet being loaded, is trained for optimal part loading onto the pallet under conditions of noise in the image. The paradigm used is …


Acuta Enews August 1991, Vol. 20, No. 8 Aug 1991

Acuta Enews August 1991, Vol. 20, No. 8

ACUTA Newsletters

In This Issue

President's column

Business meeting

Regional meetings

User groups

Director's column

Workshop in Atlanta


Electromagnetic Field Plot Of An Inductive Window By The Moment Method, John R. Natzke, Mark R. Wolski, Thomas Koryu Ishii Aug 1991

Electromagnetic Field Plot Of An Inductive Window By The Moment Method, John R. Natzke, Mark R. Wolski, Thomas Koryu Ishii

Faculty Publications - Department of Electrical Engineering and Computer Science

A moment method is used to plot the electromagnetic field of an inductive window in a TE10 -mode rectangular waveguide. Green's dyadic functions are derived based on Tai's approach, which is a modified form of Hansen's vector wave functions. Based on the computed electric fields, the S matrix and the equivalent aperture reactance of the waveguide window are calculated. This calculation agrees with the previously published closed-form results of Marcuvitz.


Ccfss News August 1991, Wei-Wen Yu Center For Cold-Formed Steel Structures Aug 1991

Ccfss News August 1991, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.


Efficient Single-Heterojunction Al0.27Ga0.73As/Gaas P-I-N Photodiodes With 22-Ghz Bandwidths, C. Johnson, S. Sloan, D. M. Braun, J. L. Russell, M. Zurakowski, M. Lightner, F. Kellert, G. Patterson, R. Koo, Dennis J. Derickson, J. E. Bowers Aug 1991

Efficient Single-Heterojunction Al0.27Ga0.73As/Gaas P-I-N Photodiodes With 22-Ghz Bandwidths, C. Johnson, S. Sloan, D. M. Braun, J. L. Russell, M. Zurakowski, M. Lightner, F. Kellert, G. Patterson, R. Koo, Dennis J. Derickson, J. E. Bowers

Electrical Engineering

A report is presented on the design, fabrication, testing, and modeling of single-heterojunction Al0.27Ga0.73As/Ga p-i-n photodiodes for use as components in optical receivers. The photodiodes are grown by molecular beam epitaxy and fabricated as 1100-μm2 mesa structures. At 5-V reverse bias and 850 nm, 100 fF of capacitance, 90 pA of leakage current, 73% external quantum efficiency, <2% reflectivity, and 22-GHz bandwidths are typically measured.


Evaluation Of Headwalls And Outlets For Geocomposite Edge Drains On I-75 And I-71, L. John Fleckenstein, David L. Allen, Jack A. Harison Aug 1991

Evaluation Of Headwalls And Outlets For Geocomposite Edge Drains On I-75 And I-71, L. John Fleckenstein, David L. Allen, Jack A. Harison

Kentucky Transportation Center Research Report

Longitudinal, round, perforated pipe edge drains have been used along Kentucky roadways for approximately two decades. Panel (fin) edge drains were first used in Kentucky in 1984. Most of these edge drains were installed on the Interstate and Parkway systems.

Several problems related to the drains have been noted in the last seven years. A number of these problems have been observed to be related to flexible outlet pipes and headwalls.

A recent study was initiated to evaluate headwalls and outlets on I-75 from Lexington, Kentucky to Cincinnati, Ohio (approximately 70 miles) and on I-71 from Louisville, Kentucky to I-75 …


The Effect Of Defense Management Review Decision 904, Stock Funding Depot Level Reparables, On Cash Flow Within The Reparable Support Division Of The Air Force Stock Fund, Deborah A. Elliot Aug 1991

The Effect Of Defense Management Review Decision 904, Stock Funding Depot Level Reparables, On Cash Flow Within The Reparable Support Division Of The Air Force Stock Fund, Deborah A. Elliot

Theses and Dissertations

This study investigated what the potential cash flow condition of the Reparable Support Division of the Air Force Stock Fund might be after final implementation of the procedures outlined in Defense Management Review Decision 904, Stock Funding Depot Level Reparables. The operation of the future Reparable Support Division was modelled using the General Purpose Simulation Software (GPSS/H) package and future cash flow conditions were projected through use of this model. Recommendations were then made based on the results of these projections and based on other data gathered during the course of the research process.


Inhibited Spontaneous Emission By Photonic Band Gaps In A Square Lattice Of Periodic Dielectric Medium, Abdullah Al-Ghamdi Aug 1991

Inhibited Spontaneous Emission By Photonic Band Gaps In A Square Lattice Of Periodic Dielectric Medium, Abdullah Al-Ghamdi

Masters Theses

The concepts of band theory for electrons can be employed to describe the behavior of electromagnetic waves propagating in two-dimensional, periodic dielectric structures. These two-dimensional, periodic structures can produce photonic band gaps in which the spontaneous emission by atoms embedded in the structure is prohibited and as a result the performance of many semiconductor devices can be enhanced. The calculations are based on finding the eigenvalues of the algebraic equation for the frequencies of electromagnetic waves moving in a square lattice composed of square dielectric rods with different dielectric constants.


Computer Aided Process Planning System For Generating Alternative Process Plans, Rao T. Gali Aug 1991

Computer Aided Process Planning System For Generating Alternative Process Plans, Rao T. Gali

Masters Theses

Computer Aided Process Planning (CAPP) has a key role in Computer Integrated Manufacturing (CIM) as an interface between design and manufacturing. Current CAPP systems treat process planning as a static function, and always generate the same machine and process combinations. Thus, these CAPP systems are inadequate for advanced manufacturing facilities such as Flexible Manufacturing Systems (FMS). This thesis presents research conducted for the design and development of a CAPP system called Alternative Computer Aided Process Planning (A-CAPP) which generates alternative process plans by interacting with production planning and machine loading functions to satisfy system capacity constraints.

A-CAPP is a variant …


Roughness Coefficients For Selected Residue Materials, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman Aug 1991

Roughness Coefficients For Selected Residue Materials, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Analysis of surface runoff on upland areas requires identification of roughness coefficients. A laboratory study is conducted to measure Darcy-Weisbach and Manning roughness coefficients for corn, cotton, peanut, pine needles, sorghum, soybeans, sunflower, and wheat residue. Varying rates of flow are introduced into a flume in which selected amounts of residue are securely attached. Roughness coefficients are calculated from measurements of discharge rate and flow velocity. The laboratory data are used to derive regression equations for relating roughness coefficients to Reynolds number and either percent residue cover or residue rate. Separate equations are developed for Reynolds number values from 500 …


Study Of Parameters Affecting Performance Of Automotive Transmission Filters, Debra Cauthen Aug 1991

Study Of Parameters Affecting Performance Of Automotive Transmission Filters, Debra Cauthen

All Theses

Modified isocyanate binders have been introduced as a possible alternative to phenolic resins for bonding nonwovens in automatic transmission filtration. The Occupational Safety and Health Administration (OSHA) and the American Conference of Governmental Industrial Hygienists (ACGIH) have placed restrictions on worker exposure to phenol-formaldehyde due to toxicological and ecological concerns. Modified isocyanates are unproven for bonding needlefelts in this application.


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 …


33rd Rocky Mountain Conference On Applied Spectroscopy Jul 1991

33rd Rocky Mountain Conference On Applied Spectroscopy

Rocky Mountain Conference on Magnetic Resonance

Program and registration information for the 33rd annual meeting of the Rocky Mountain Conference on Applied Spectroscopy, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 28 - August 1, 1991.


Associative Processing Implemented With Content-Addressable Memories, Luis Sergio Kida Jul 1991

Associative Processing Implemented With Content-Addressable Memories, Luis Sergio Kida

Dissertations and Theses

The associative processing model provides an alternative solution to the von Neumann bottleneck. The memory of an associative computer takes some of the responsibility for processing. Only intermediate results are exchanged between memory and processor. This greatly reduces the amount of communication between them. Content-addressable memories are one implementation of memory for this computational model. Associative computers implemented with CAMs have reported performance improvements of three orders of magnitude, which is equivalent to the performance of the same application running in a conventional computer with clock frequencies of the order of GHz. Among the benefits of content-addressable memories to the …


Antique Farm Machinery And Equipment Commission July, 1991, Tractor Museum Jul 1991

Antique Farm Machinery And Equipment Commission July, 1991, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

No abstract provided.


Optimal Aquifer Planning With Salt Water Boundary, Richard C. Peralta, Shu Takahashi Jul 1991

Optimal Aquifer Planning With Salt Water Boundary, Richard C. Peralta, Shu Takahashi

Civil and Environmental Engineering Faculty Publications

Optimal sustained-yield pumping strategies were developed for the irrigated and industrialized eastern shore of the Great Salt Lake. The combined optimization and simulation model, in which steady-state, finite difference, quasi-three-dimensional ground water flow equations were embedded as constraints, computes the optima,! distribution for sustainable annual ground water pumping rates for alternative scenarios. 1. The model deals with management of a large, multilayer, confined/unconfined (linear/nonlinear) aquifer system. 2. The research can help manage water in the study area where· the demand for water of sufficient quality and quantity is increasing due to urbanization.


Solutal Partition Coefficients In Nickel-Based Superalloy Pwa-1480, Surendra N. Tewari, M. Vijayakumar, James E. Lee, P. A. Curreri Jul 1991

Solutal Partition Coefficients In Nickel-Based Superalloy Pwa-1480, Surendra N. Tewari, M. Vijayakumar, James E. Lee, P. A. Curreri

Chemical & Biomedical Engineering Faculty Publications

Solutal profiles in dendritic single-crystal specimens of PWA-1480 nickel-base superalloy, which were directionally solidified and quenched, were examined on several transverse cross-sections to obtain the partition coefficients. Similar to their nickel-base binaries, the partition coefficients of tantalum, titanium, and aluminum were found to be less than unity; those of tungsten and cobalt were greater than unity. The partition coefficients were temperature independent in the range 1584-1608 K. The contribution of solid-state diffusion to microsegregation was observed to be negligible.


Computer-Based Parameter Visualization And Decision Making For The Detection And Prediction Of Ovulation: The Ovulo-Computer, Omar Rodolfo Bermudez Jul 1991

Computer-Based Parameter Visualization And Decision Making For The Detection And Prediction Of Ovulation: The Ovulo-Computer, Omar Rodolfo Bermudez

Dissertations and Theses

It is now well accepted by gynecologists that a woman can conceive from an act of intercourse for a maximum of seven days of her menstrual cycle [1]. The reliability of natural family planning methods depends on identifying this window of fertility without ambiguity. Several natural family planning (NFP) methods have been used extensively and with some success. For decades, cycle length and BBT history have been used to forecast the most likely days of ovulation. When greater precision is needed, serum LH assays or ultrasound techniques are used. With the recent development of enzyme-linked immunosorbent assay, various kits have …


Acuta Enews July 1991, Vol. 20, No. 7 Jul 1991

Acuta Enews July 1991, Vol. 20, No. 7

ACUTA Newsletters

In This Issue

ACUTA Forum

Unblocking 1-0-XXX

President's farewell

Affordable fiber to the desk

Value of utility bill audits

$60 million math/science network


Santa Clara Magazine, Volume 33 Number 4, Summer 1991, Santa Clara University Jul 1991

Santa Clara Magazine, Volume 33 Number 4, Summer 1991, Santa Clara University

Santa Clara Magazine

12 - GEORGE BUSH AND THE QUESTION OF STYLE The president's campaign strategists have had Bush play up the victory in the Persian Gulf and avoid talk of much else. By Rita Beamish '74

17 - MIND OVER MONEY Challenging accepted notions about how to make money in the stock market through research on the psychology of investing. By Kathryn Bold '81

20 - STRESS: THE DEMOCRATIC AILMENT From bricklayers to stock brokers, everyone is susceptible to stress. By Elizabeth Fernandez '79

24 - CHARLES LAMPKIN: ON THE LONG ROAD Remembering the actor and music man who was SCU's artist-inresidence …


Impulse, Carrie Sword, Carey Crouse, Ross Berndt, Steve Poessnecker Jul 1991

Impulse, Carrie Sword, Carey Crouse, Ross Berndt, Steve Poessnecker

Impulse (Jerome J. Lohr College of Engineering Publication)

Features:
[Page 2] Water research: Saving for a 'dry day'
[Page 4] Regional water center enjoys benefits of Brookings
[Page 5] Feed Jake'
[Page 6] SDSU honors distinguished engineers
[Page 8] Scholarships awarded at annual banquet
[Page 10] New South Dakota businesses proposed by SDSU students

Departments:
Faculty:
[Page 11] Transportation technology service receives funding
[Page 11] Wayne Knabach honored
[Page 12] Faculty and students attendance at Dalton.
[Page 12] Conference focuses on women, minorities
[Page 13] Professors receive doctorates
[Page 13] Fulbright Scholar
[Page 14] Two retire from College of Engineering faculty
[Page 14] Former dean of engineering dies …


Tardiness Heuristic For Scheduling Flexible Manufacturing Systems, Ali S. Kiran, Sema E. Alptekin, A. Celal Kaplan Jul 1991

Tardiness Heuristic For Scheduling Flexible Manufacturing Systems, Ali S. Kiran, Sema E. Alptekin, A. Celal Kaplan

Industrial and Manufacturing Engineering

This paper evaluates the tardiness performance of a sampling-based adaptive heuristic in a dynamic manufacturing environment. A test bed, following a real world manufacturing system, has been developed. The proposed algorithm has been implemented in this simulated environment. After fine tuning the algorithm, it has been tested in various shop conditions. The results of these simulation studies are summarized.


The Calendar - July And August 1991, Nova University Jul 1991

The Calendar - July And August 1991, Nova University

The Calendar

No abstract provided.