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1992

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Articles 1 - 30 of 1073

Full-Text Articles in Engineering

Method For Treating Rare Earth-Transition Metal Scrap, Frederick A. Schmidt, David T. Peterson, John T. Wheelock, Lawrence L. Jones Dec 1992

Method For Treating Rare Earth-Transition Metal Scrap, Frederick A. Schmidt, David T. Peterson, John T. Wheelock, Lawrence L. Jones

Iowa State University Patents

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite ...


Thermally Activated Reversible Threshold Shifts In Yba2Cu3O7-Δ/Yttria-Stabilized Zirconia/Si Capacitors, Jianmin Qiao, Eric M. Ajimine, Paresh P. Patel, Geoffrey L. Giese, Cary Y. Yang Dec 1992

Thermally Activated Reversible Threshold Shifts In Yba2Cu3O7-Δ/Yttria-Stabilized Zirconia/Si Capacitors, Jianmin Qiao, Eric M. Ajimine, Paresh P. Patel, Geoffrey L. Giese, Cary Y. Yang

Electrical and Computer Engineering

Yba2Cu3O7-δ/yttria‐stabilized zirconia (YSZ)/silicon superconductor–insulator–semiconductor capacitors are characterized with capacitance‐voltage (C‐V) measurements at different gate‐voltage sweep rates and under bias‐temperature cycling. It is shown that ionic conduction in YSZ causes both hysteresis and stretch‐out in room‐temperature C‐V curves. A thermally activated process with an activation energy of about 39 meV in YSZ and/or at YSZ/Si interface is attributed to trapping/detrapping mechanisms in the SiOx interfacial layer between YSZ and Si. The negative mobile ions in YSZ can be moved by ...


Nanosecond Transient Electroluminescene From Polymer Light-Emitting Diodes, David Braun, D. Moses, C. Zhang, A. J. Heeger Dec 1992

Nanosecond Transient Electroluminescene From Polymer Light-Emitting Diodes, David Braun, D. Moses, C. Zhang, A. J. Heeger

Electrical Engineering

The transient electroluminescence from polymer light-emitting diodes is reported. When the devices are mounted on a microstrip transmission line, the temporal response is limited by the electrode geometry, with rise and fall times below 50 ns. With low duty-cycle pulses (0.5%) the electroluminescence intensity remains proportional to the current at values up to 10 A/cm2, two orders of magnitude greater than possible under direct current operation. Since the spectral blue-shift observed at high current levels (with power dissipation above 1 W/cm2) indicates significant sample heating, still higher levels should be possible with proper thermal management.


Free-Radical Retrograde Precipitation-Polymerization Process, Gerard T. Caneba Dec 1992

Free-Radical Retrograde Precipitation-Polymerization Process, Gerard T. Caneba

Michigan Tech Patents

A free-radical retrograde polymerization process for forming a polymer. An admixture of reactants including predetermined amounts of a monomer, a solvent, and a free-radical-initiator is reacted. A precipitation polymerization reaction occurs such that a polymer-rich phase is at a temperature generally above the lower critical solution temperature (LCST) of the admixture.


Fuzzy Logic Applied To Adaptive Kalman Filtering, Marlys Rae Remus Dec 1992

Fuzzy Logic Applied To Adaptive Kalman Filtering, Marlys Rae Remus

Theses, Dissertations, and Student Research from Electrical & Computer Engineering

The Kalman filter provides an effective means of estimating the state of a system from noisy measurements given that the system parameters are completely specified. The innovations sequence for a properly specified Kalman filter will be a zero-mean white noise process. However, when the system parameters change with time the Kalman filter will need to be adapted to compensate for the changes. Traditionally this has been accomplished by using nonlinear filtering, parallel Kalman filtering and covariance matching techniques. These methods have produced good results at the expense of large amounts of computational time. Necessary changes in the system parameters become ...


Image Segmentation Using An Annealed Hopfield Neural Network, Yungsik Kim, Sarah A. Rajala Dec 1992

Image Segmentation Using An Annealed Hopfield Neural Network, Yungsik Kim, Sarah A. Rajala

Sarah A. Rajala

Good image segmentation can be achieved by finding the optimum solution to an appropriate energy function. A Hopfield neural network has been shown to solve complex optimization problems fast, but it only guarantees convergence to a local minimum of the optimization function. Alternatively, mean field annealing has been shown to reach the global or the nearly global optimum solution when solving optimization problems. Furthermore, it has been shown that there is a relationship between a Hopfield neural network and mean field annealing. In this paper, we combine the advantages of the Hopfield neural network and the mean field annealing algorithm ...


Turbomachine Stability And Forced Response Prediction, Leland Bert Clark Dec 1992

Turbomachine Stability And Forced Response Prediction, Leland Bert Clark

Open Access Theses

A mathematical model is developed and utilized to analyze turbomachine cascade flutter and forced response. The flutter boundary, defined as the largest value of reduced frequency at which flutter occurs for a given cascade, was evaluated for single degree of freedom torsional oscillation as well as coupled bending and torsional oscillations. The maximum amplitude of forced response in bending and torsion was also considered. The unsteady aerodynamic lift and moment coefficients were determined from unsteady aerodynamic flow models for subsonic flow, supersonic flow with a subsonic axial component and supersonic axial flow. The effect of changing the Mach number, stagger ...


High-Level Expression Of A Heterologous Protein In The Milk Of Transgenic Swine Using The Cdna Encoding Human Protein C, William H. Velander, John L. Johnson, Raymond L. Page, Christopher G. Russell, Anuradha Subramanian, Tracy D. Wilkins, Francis C. Gwazdauskas, Christoph Pittius, William N. Drohan Dec 1992

High-Level Expression Of A Heterologous Protein In The Milk Of Transgenic Swine Using The Cdna Encoding Human Protein C, William H. Velander, John L. Johnson, Raymond L. Page, Christopher G. Russell, Anuradha Subramanian, Tracy D. Wilkins, Francis C. Gwazdauskas, Christoph Pittius, William N. Drohan

William H. Velander Publications

Transgenic pigs were generated that produced human protein C in their milk at up to 1 g/liter. The gene construct was a fusion gene consisting of the cDNA for human protein C inserted into the first exon of the mouse whey acidic protein gene. These results demonstrate that the mouse whey acidic protein gene contains regulatory elements that can direct cDNA expression at high levels in the pig mammary gland. Recombinant human protein C that was produced at about 380 pg/ml per hr in transgenic pig milk possessed anticoagulant activity that was equivalent to that of protein C ...


Method Of Predicting Cut-Time Of Milk Coagulum In Cheese-Making Process, Frederick A. Payne, Clair L. Hicks Dec 1992

Method Of Predicting Cut-Time Of Milk Coagulum In Cheese-Making Process, Frederick A. Payne, Clair L. Hicks

Biosystems and Agricultural Engineering Faculty Patents

An apparatus for predicting milk coagulum cut-time in a cheese making process includes a light source, a sensor or detector for sensing diffuse reflectance of light from said milk and a controller for analyzing the diffuse reflectance and accurately predicting the cut-time to significantly enhance overall yield. More specifically, the apparatus includes an optical probe which may be suspended over the milk or attached to a wall of a fermentation vessel in which the milk is contained. A method for predicting milk coagulum cut-time includes the steps of (a) directing light from a light source toward milk undergoing enzymatic hydrolysis ...


A Computational Algorithm For Squaring-Up, Part I: Zero Input-Output Matrix, Pradeep Misra Dec 1992

A Computational Algorithm For Squaring-Up, Part I: Zero Input-Output Matrix, Pradeep Misra

Pradeep Misra

In this paper, some preliminary results on the problem
of squaring-up a non-square linear multivariable system
are presented. It. is shown that. for the case considered
here. the squaring-up problem can be transformed into a
state feedback problem. An illustrative numerical example
is included to illustrate the results developed.


Utilizing Instructional Design Constructs To Enhance Computer-Based Instruction In Air Traffic Controller Training, Theodore Scott Rhoads Dec 1992

Utilizing Instructional Design Constructs To Enhance Computer-Based Instruction In Air Traffic Controller Training, Theodore Scott Rhoads

Theses - Daytona Beach

This study demonstrates that a computer-based instructional design format is appropriate for novice air traffic control (ATC) training. The computer presents the student with small amounts of information in tutorial and drill and practice sequences that necessitate student interactivity. The student is then periodically audit tested to ascertain mastery of the subject matter. The result of these mid-lesson evaluations serve as a self-check so that the student can assess his/her progress in the learning cycle. The systematic design of instruction and interactive approach to learning, enhances student motivation, improves learning and retention, while placing the responsibility of achieving specific ...


Active Vibration Control Device, Keith E. Rouch, Sanjiv Tewani, Bruce L. Walcott, Ted R. Massa, Robert W. Stephenson, L. Scott Stephens Dec 1992

Active Vibration Control Device, Keith E. Rouch, Sanjiv Tewani, Bruce L. Walcott, Ted R. Massa, Robert W. Stephenson, L. Scott Stephens

Mechanical Engineering Faculty Patents

An active vibration control device for controlling vibration in a cantilevered member and a method for the same are disclosed. The device is comprised of a cantilevered member having a longitudinal axis comprising a sensor mounted near the free end of the member to measure motion of the member in a transverse direction and to produce a corresponding signal. A force generating assembly is mounted to the member near the free end to oppose the measured motion with a force thereby minimizing subsequent motion along the transverse axis caused by vibration.


Semiconductor P-N Junction Space Charge Region Capacitance, Mohammad Humayun Habib Dec 1992

Semiconductor P-N Junction Space Charge Region Capacitance, Mohammad Humayun Habib

Dissertations and Theses

The classical capacitance voltage characteristics based on the depletion approximation, is adequate at reverse bias, but introduces errors at high forward bias. Because of its inherent simplicity and compactness this classical depletion model is well studied and widely used in circuit simulators. In this work, a new model for the semiconductor space charge region (SCR) capacitance, based on physical justification, will be derived. This new model takes three input parameters, C0 , Vbi and m, thus eliminating the fitting parameter FC currently used in SPICE. This new model is applicable for any applied voltage and will be compared with the SCR ...


The Role And Responsibility Of The Agricultural Professional In Promoting Farmers' Safety And Health, C. J. Lehtola Dec 1992

The Role And Responsibility Of The Agricultural Professional In Promoting Farmers' Safety And Health, C. J. Lehtola

Proceedings of the Integrated Crop Management Conference

Farmers indicate they expect and request farm safety services and information from the local farm chemical dealers. This workshop identifies agricultural hazards associated with crop production; e.g., tractors, machinery, and chemicals. Emphasis is placed on discussing the roles and responsibilities of the agricultural professional towards enhancing and promoting farmers' safety and health by means of various intervention strategies. Workshop participants will participate in group discussions in order to identify and recommend additional ways in which they can better serve their clientele in this crucial area.


Understanding And Reducing Pesticide Losses, James Baker, Ed Adcock, Gerald Miller Dec 1992

Understanding And Reducing Pesticide Losses, James Baker, Ed Adcock, Gerald Miller

Proceedings of the Integrated Crop Management Conference

A small portion of pesticides applied on farms inadvertently reaches surface and groundwater. The amount varies from nearly zero to sometimes more than 5 percent of the amount applied, depending on several factors discussed below. That may not seem like much, but a 1 percent loss of a 1-pound-per-acre pesticide application can contaminate all of the drainage from a field in a normal year at 5 parts per billion (ppb). This level can be of concern if the drainage water enters drinking water supplies. The U.S. Environmental Protection Agency has established Health Advisory Levels for most pesticides in drinking ...


Residue Management With Chisel-Type Implements, Richard Johnson Dec 1992

Residue Management With Chisel-Type Implements, Richard Johnson

Proceedings of the Integrated Crop Management Conference

Where chisels are improperly used, it may be difficult to end up with 30% surface cover. But by considering one or more of the following, 30 to 50% surface cover after planting should be possible:


Tillage Equipment Adjustment For Surface Residue, Mark Hanna Dec 1992

Tillage Equipment Adjustment For Surface Residue, Mark Hanna

Proceedings of the Integrated Crop Management Conference

Crop producers are increasingly interested in methods to manage higher levels of surface residue. Both economics and soil conservation are responsible for this attention. Six million additional Iowa acres will be shifted to a conservation tillage system during 1992-94 to comply with soil loss goals of the Food Security Act according to plans filed with the Soil Conservation Service. From a production cost viewpoint, fewer machine operations on the land lower input costs and increase net profit if output can be maintained.


Crop Residue Management- Part Of Farming In The Future, Jeffrey J. Zimprich Dec 1992

Crop Residue Management- Part Of Farming In The Future, Jeffrey J. Zimprich

Proceedings of the Integrated Crop Management Conference

Farming systems that manage crop residue are becoming more and more popular today. Interest and enthusiasm in crop residue management indicates that these farming practices will be part of farming in the future. Profit and conservation are driving these upward trends.


Guide To Revenue Calculations: Local Option Highway User Tax 1992, Jon D. Fricker Dec 1992

Guide To Revenue Calculations: Local Option Highway User Tax 1992, Jon D. Fricker

Indiana Local Technical Assistance Program (LTAP) Publications

This guide is provided to explain the output generated by the computer programs, and to suggest ways in which the results can be adapted to specific LOHUT proposals before a County Council. HERPICC neither endorses nor opposes passage of a LOHUT. The revenue projections it provides are intended to be an aid to well-informed decision-making on the part of a county’s citizens and its County Council.


Royal Institute Of Technology: Department Of Polymer Technology, Otto Vogl, Ann Christine Albertsson Dec 1992

Royal Institute Of Technology: Department Of Polymer Technology, Otto Vogl, Ann Christine Albertsson

Emeritus Faculty Author Gallery

No abstract provided.


70. Obituary, Herman F. Mark, Otto Vogl Dec 1992

70. Obituary, Herman F. Mark, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.


Possible Applications Of Neural Nets To Power System Operation And Control, P. K. Kalra, Alok Srivastava, D. K. Chaturvedi Dec 1992

Possible Applications Of Neural Nets To Power System Operation And Control, P. K. Kalra, Alok Srivastava, D. K. Chaturvedi

D. K. Chaturvedi Dr.

Problems related to power system operation and control are complex and time consuming because of the non-linearities involved in their formulation and solution. Fast solutions to these problems can be obtained only through parallel processing. Neural nets provide massive parallel processing facilities and may also be used efficiently to model systems with non-linearities. The capabilities of neural nets can, therefore, be well utilized in modelling and processing problems related to power systems. In order to reduce the burden on computers, algorithms involving optimization and complex equations can be converted to heuristics. These heuristics can then be represented in terms of ...


Viscosities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements Dec 1992

Viscosities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements

Papers in Biomaterials

Data for viscosity as a function of temperature from 24 to llO°C (75 to 230°F) have been measured for a number of vegetable oils (crambe, rapeseed, corn, soybean, milk- coconut, lesquerella) and eight fatty acids in the from Cg to CZZ The viscosity measurements were performed according to ASTM test methods D 445 and D 446. Several correlations were fitted to the experimental data. Correlation constants for the best fit are presented. The range of temperature in which the correlations are valid is from 24'C (75'F), or the melting point of the substance, to llO°C ...


Losses In Electric Power Systems, E. Benedict, T. Collins, D. Gotham, S. Hoffman, D. Karipides, S. Pekarek, R. Ramabhadran Dec 1992

Losses In Electric Power Systems, E. Benedict, T. Collins, D. Gotham, S. Hoffman, D. Karipides, S. Pekarek, R. Ramabhadran

Department of Electrical and Computer Engineering Technical Reports

This report concerns losses in power systems. The report was assembled by seven authors in EE 532 class at Purdue University in December, 1992. The work was part of a class project on losses . All aspects of losses are discussed from the transmission system through utilization stages. High efficiency motors and lighting are also considered . The students participating in this project also videotaped presentations on power system losses .


Densities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements Dec 1992

Densities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements

Papers in Biomaterials

Complete data for density as a function of temperature have been measured for a number of vegetable oils (cramhe, rapeseed, corn, soybean, milkweed, coconut, lesquerella), as well as eight fatty acids in the range CS to C,, at temperatures from above their melting points to llQ°C (23Q°F). The specific gravity and density measure mente were performed according to American Society for Testing and Materials (ASTM) standard test methods D 368, D 891 and D 1298 for hydrometers and a modified ASTM D 369 and D 891 for pycnometers. Correlation constants, based on the experimental data, are presented for ...


Acuta Enews December 1992, Vol. 21, No. 12 Dec 1992

Acuta Enews December 1992, Vol. 21, No. 12

ACUTA Newsletters

In This Issue

Regulatory update

President's column

Dual routing protects Duke

Talking clock "tells" time

Seminar ratings

Director's column


High-Level Expression Of A Heterologous Protein In The Milk Of Transgenic Swine Using The Cdna Encoding Human Protein C, William H. Velander, John L. Johnson, Raymond L. Page, Chritopher G. Russell, Anuradha Subramanian, Tracy D. Wilkins, Francis C. Gwazdauskas, Christoph Pittus, William N. Drohan Dec 1992

High-Level Expression Of A Heterologous Protein In The Milk Of Transgenic Swine Using The Cdna Encoding Human Protein C, William H. Velander, John L. Johnson, Raymond L. Page, Chritopher G. Russell, Anuradha Subramanian, Tracy D. Wilkins, Francis C. Gwazdauskas, Christoph Pittus, William N. Drohan

Papers in Biotechnology

Transgenic pigs were generated that produced human protein C in their milk at up to 1 g/liter. The gene construct was a fusion gene consisting of the cDNA for human protein C inserted into the first exon of the mouse whey acidic protein gene. These results demonstrate that the mouse whey acidic protein gene contains regulatory elements that can direct cDNA expression at high levels in the pig mammary gland. Recombinant human protein C that was produced at about 380 pg/ml per hr in transgenic pig milk possessed anticoagulant activity that was equivalent to that of protein C ...


10th Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences Dec 1992

10th Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 10th Conference on Senior Engineering Design Projects was held on December 8, 1992 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.


Development And Analysis Of Non-Delay-Line Constant-Fraction Discriminator Timing Circuits, Including A Fully-Monolithic Cmos Implementation, David Martin Binkley Dec 1992

Development And Analysis Of Non-Delay-Line Constant-Fraction Discriminator Timing Circuits, Including A Fully-Monolithic Cmos Implementation, David Martin Binkley

Doctoral Dissertations

A constant-fraction discriminator (CFD) is a time pick-off circuit providing time derivation that is insensitive to input-signal amplitude and, in some cases, input-signal rise time. CFD time pick-off circuits are useful in Positron Emission Tomography (PET) systems where Bismuth Germanate (BGO)/photomultiplier scintillation detectors detect coincident, 511-keV annihilation gamma rays.

Time walk and noise-induced timing jitter in time pick-off circuits are discussed along with optimal and sub-optimal timing filters designed to minimize timing jitter. Additionally, the effects of scintillation-detector statistics on timing performance are discussed, and Monte Carlo analysis is developed to provide estimated timing and energy spectra for selected ...


Thermally Induced Vibration Of A Cross-Ply Laminated Plate With Hygrothermal Effects (Exact Solution), Stephen Jerry Maerz Dec 1992

Thermally Induced Vibration Of A Cross-Ply Laminated Plate With Hygrothermal Effects (Exact Solution), Stephen Jerry Maerz

Theses - Daytona Beach

Of increasing importance in structural design is the use of fiber-reinforced polymeric composite material, notably in advanced aircraft and projectiles. These applications expose the materials to varied environmental conditions, therefore the material performance under these conditions is of great interest. One aspect of this is the solution of the dynamic response of a composite structure under elevated temperature and moisture conditions. An exact solution is formulated which describes the hygrothermal effects due to heating and moisture diffusion on one surface of a symmetric cross-ply plate made of AS/3501 graphite epoxy with simply-supported boundary conditions.