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University of Nebraska - Lincoln

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Full-Text Articles in Engineering

Water Vapor Permeability And Mechanical Properties Of Grain Protein-Based Films As Effected By Mixtures Of Polyethylene Glycol Amd Glycerin Plasticizers, H. J. Park, J. M. Bunn, Curtis L. Weller, P. J. Vergano, R. F. Testin Jan 1994

Water Vapor Permeability And Mechanical Properties Of Grain Protein-Based Films As Effected By Mixtures Of Polyethylene Glycol Amd Glycerin Plasticizers, H. J. Park, J. M. Bunn, Curtis L. Weller, P. J. Vergano, R. F. Testin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain protein-based films containing mixtures of glycerin and polyethylene glycol (PEG) as plasticizers were prepared and evaluated for water vapor permeability (WVP), tensile strength (TS), and elongation (E). Changes in mechanical properties during storage were also studied. The PEG produced opposite trends in E of wheat gluten and corn-zein films. The TS of wheat gluten films increased and E of the films decreased as the ratio of glycerin/PEG decreased. Corn-zein films containing only glycerin were very brittle (E of 4%), and E of the films improved to 94% when the ratio of mL PEG/g protein was 0.39. The WVP of …


Long Term Tillage Effects On Grain Yield And Soil Properties In A Soybean/Grain Sorghum Rotation, Elbert C. Dickey, Paul J. Jasa, Robert Grisso Jan 1994

Long Term Tillage Effects On Grain Yield And Soil Properties In A Soybean/Grain Sorghum Rotation, Elbert C. Dickey, Paul J. Jasa, Robert Grisso

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In Nebraska, early adopters of conservation tillage, especially those using no-till planting, had some concerns regarding planter performance, early season weed control, and possible yield reductions. Selected tillage and planting systems were used long term to evaluate effects on soybean [Glycine max (L.) Merr.] and grain sorghum [Sorghum bicolor (L.) Moench] yield, soil properties, and residue cover in a non-irrigated rotation. The six tillage and planting systems selected for evaluation were: no-till, no-till with row-crop cultivation, disk, double disk, chisel, and plow. In 1981, two sets of field plots were established near Lincoln, NE, on a Sharpsburg silty …


Tillage And Planting System, Stalk Chopper, And Knife Applicator Influences On Corn Residue Cover, David P. Shelton, Stephen D. Kachman, Elbert C. Dickey, K.T. Fairbanks, Paul J. Jasa Jan 1994

Tillage And Planting System, Stalk Chopper, And Knife Applicator Influences On Corn Residue Cover, David P. Shelton, Stephen D. Kachman, Elbert C. Dickey, K.T. Fairbanks, Paul J. Jasa

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Percent corn (Zea mays L.) residue cover remaining on the soil surface after planting was measured for 11 tillage and planting systems that included combinations of the use, and timing, of a stalk chopper and/or a knife-type fertilizer applicator. Tillage, as well as use of a stalk chopper or knife applicator, significantly reduced residue cover. Only 27 of the 69 stalk chopper/knife applicator/tillage and planting system treatment combinations that were evaluated could be classified as conservation tillage by having at least 30% residue cover remaining after planting.


Monte Carlo Calculation Of Effective Diffusivities In Two- And Three-Dimensional Heterogeneous Materials Of Variable Structure, Mark R. Riley, Fernando J. Muzzio, Helen M. Buettner, Sebastian C. Reyes Jan 1994

Monte Carlo Calculation Of Effective Diffusivities In Two- And Three-Dimensional Heterogeneous Materials Of Variable Structure, Mark R. Riley, Fernando J. Muzzio, Helen M. Buettner, Sebastian C. Reyes

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A Monte Carlo technique that simulates tracer diffusion in multiphase materials of arbitrary complexity has been developed. Effective diffusivities are calculated for structures consisting of either overlapping or nonoverlapping inclusions with diffusivity Dc, distributed in a continuous phase with diffusivity D0>Dc. Two-dimensional simulations for various values of D0/Dc generate normalized diffusivities that correspond closely to their three-dimensional counterparts; they nearly collapse to a common curve when a simple scaling relation is applied.


Moisture Adsorption By Grain Protein Films, A. Gennadios, Curtis L. Weller Jan 1994

Moisture Adsorption By Grain Protein Films, A. Gennadios, Curtis L. Weller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain protein films plasticized with glycerol were prepared from corn zein (CZ), wheat gluten (WG), and a 2.3:1 mixture of wheat gluten and soy protein isolate (WG/SPI). Moisture adsorption curves of the three types of protein films at 25° C and within an approximate water activity range of 0.11 to 0.84 were obtained using a static gravimetric method. The Smith, Oswin, Halsey, and Guggenheim-Anderson-de Boer (GAB) models were applied to collected data. For all protein films, the GAB model showed the best fit over the entire studied water activity range yielding mean deviation modulus values (P) of 4.69, 3.44, and …


Acuta Enews December 1993, Vol. 22, No. 12 Dec 1993

Acuta Enews December 1993, Vol. 22, No. 12

ACUTA Newsletters

In This Issue

Board Report

President's message

Telecom talks $$$ at UNM

US West to test high speed transmission

Big MAN on campus

Student toll fraud


Wildlife Exposure Factors Handbook, Appendix: Literature Review Database, Volume Ii Of Ii, United States Environmental Protection Agency Dec 1993

Wildlife Exposure Factors Handbook, Appendix: Literature Review Database, Volume Ii Of Ii, United States Environmental Protection Agency

United States Environmental Protection Agency: Publications

This Appendix is intended to accompany the Wildlife Exposure Factors Handbook (hereafter referred to as the Handbook) and should be used only by individuals familiar with the Handbook. The species-specific values for the exposure factors presented in Chapter 2 of the Handbook of are a subset of the data included in the tables of this Appendix. Most values identified in the literature reviewed for the Handbook are included in this Appendix. For some exposure factors for some species, large quantities of data are available. For these factors and species, we tried to select data that represented a range of values …


Wildlife Exposure Factors Handbook, Volume I Of Ii, United States Environmental Protection Agency Dec 1993

Wildlife Exposure Factors Handbook, Volume I Of Ii, United States Environmental Protection Agency

United States Environmental Protection Agency: Publications

The Exposure Assessment Group of the Office of Health and Environmental Assessment (OHEA) has prepared the Wildlife Exposure Handbook in support of the Office of Solid Waste and Emergency Response and the Office of Water. The Handbook provides information on various factors used to assess exposure to wildlife. The goals of the project are (1) to promote the application of risk assessment methods to wildlife species, (2) to foster a consistent approach to wildlife exposure and risk assessments, and (3) to increase the accessibility of the literature applicable to these assessments.
The bulk of the document summarizes literature values for …


Simple High-Quality Lossy Image Coding Scheme, Shaolin Bi, Khalid Sayood Nov 1993

Simple High-Quality Lossy Image Coding Scheme, Shaolin Bi, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

A simple yet efficient image data compression method is presented. This method is based on coding only those segments of the image that are perceptually significant to the reconstruction of the image. Sequences of image pixels whose gray-level differences from the pixels of the previous row exceed two prespecified thresholds are considered significant. These pixels are coded using a differential pulse code modulation scheme that uses a 15-level recursively indexed nonuniform quantizer for the first pixel in a segment and a 7-level recursively indexed nonuniform quantizer for all other pixels in the segment. The quantizer outputs are Huffman coded. Simulation …


Acuta Enews November 1993, Vol. 22, No. 11 Nov 1993

Acuta Enews November 1993, Vol. 22, No. 11

ACUTA Newsletters

In This Issue

Board Report

President's message

TASA commissions

Numbering plan means net manager pains

21st Century Technology

Toll Fraud


A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory Nov 1993

A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory

Department of Industrial and Management Systems Engineering: Presentations

One of the more difficult tasks facing a modeler in developing a simulation model of a discrete part manufacturing system is deciding at what level of abstraction to represent the resources of the system. For example, questions about plant capacity can be modeled with a simple model, whereas questions regarding the efficiency of different part scheduling rules can only be answered with a more detailed model. In developing a simulation model, most of the actual features of the system under study must be ignored and an abstraction must be developed. If done correctly, this idealization provides a useful approximation of …


A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory Nov 1993

A Robust Aggregation Approach To Simplification Of Manufacturing Flow Line Models, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

One of the more difficult tasks facing a modeler in developing a simulation model of a discrete part manufacturing system is deciding at what level of abstraction to represent the resources of the system. For example, questions about plant capacity can be modeled with a simple model, whereas questions regarding the efficiency of different part scheduling rules can only be answered with a more detailed model. In developing a simulation model, most of the actual features of the system under study must be ignored and an abstraction must be developed. If done correctly, this idealization provides a useful approximation of …


Minutes Of Tractor Test Museum Committee October 21, 1993, Tractor Museum Oct 1993

Minutes Of Tractor Test Museum Committee October 21, 1993, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Status of using tractor test building. Organizing Friends of the Tractor Test Museum


Notes From Museum Committee Meeting October, 1993, Tractor Museum Oct 1993

Notes From Museum Committee Meeting October, 1993, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

No abstract provided.


Acuta Enews October 1993, Vol. 22, No. 10 Oct 1993

Acuta Enews October 1993, Vol. 22, No. 10

ACUTA Newsletters

In This Issue

E-mail

President's message

Data Comm Project at Delaware Tech

User Groups Meet at Conference

21st Century Technology

Staff Report


Closure To "Darcy-Weisbach Roughness Coefficients For Gravel And Cobble Surface", John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman Oct 1993

Closure To "Darcy-Weisbach Roughness Coefficients For Gravel And Cobble Surface", John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The writers appreciate the interest expressed by the discussers in this manuscript, and are pleased to have the opportunity to further discuss this material. The discussion states that the writers have generally examined a condition already investigated in other previous studies. Reynolds number values and roughness element size for the articles referenced by the discussers are shown in Table 5. Since flow rate and Reynolds number values were not given by Ferro and Giordano (1991), data from this study are not included in Table 5.
It can be seen from Table 5 that the roughness element sizes examined by Bathurst …


Gyroless Line-Of-Sight Stabilization For Pointing And Tracking Systems, Marcelo C. Aigrain Sep 1993

Gyroless Line-Of-Sight Stabilization For Pointing And Tracking Systems, Marcelo C. Aigrain

Department of Electrical and Computer Engineering: Faculty Publications

A new platform stabilization approach is described where miature, low-cost, linear accelerometers are used (instead of gyroscopes) for line-of-sight (LOS) stabilization. This is accomplished by placing the accelerometers at strategic locations and combining their outputs so that angular motion is determined from linear acceleration measurements. The control system uses the sensed angular accelerations to generate movement commands for the gimbal servomotors in the stabilization platform. This counterrotates the imaging device to stabilize its LOS. The use of accelerometers allows the servo system to operate in an acceleration control mode, which is more desirable than position or velocity control modes, typical …


Acuta Enews September 1993, Vol. 22, No. 9 Sep 1993

Acuta Enews September 1993, Vol. 22, No. 9

ACUTA Newsletters

In This Issue

Emergency phones

President's message

FCC opens up local loop

CWRU cuts phone bill by 20%

Staff report


Acuta Enews August 1993, Vol. 22, No. 8 Aug 1993

Acuta Enews August 1993, Vol. 22, No. 8

ACUTA Newsletters

In This Issue

Interview with Luther Robb

President's Message

Paradigms & Paradoxes

Total Quality Management

Super Schools

Win-Win Relationships

21st Century Technology

Executive Director's Message


Tillage And Cropping Practice Effects On Furrow Irrigation: Hydraulics And Macroporosity, Martin John Norton Aug 1993

Tillage And Cropping Practice Effects On Furrow Irrigation: Hydraulics And Macroporosity, Martin John Norton

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Furrow irrigation efficiency and performance is greatly influenced by advance time, infiltration and roughness. An experiment was conducted to determine tillage system and cropping system effects on those three variables. Four tillage systems, disk (D), chisel and disk (C), ridge till (RT), and slot plant (SP) were the treatments. They had been continuous for 17 years on a Hasting's silt loam (fine, montmorillonitic, mesic Udic Argistoll) soil. Subtreatments were a corn/soybean rotation (CS) and a continuous corn (CC) cropping system since 1984. A complete block split plot design was used. We measured inflow rate, advance time, runoff, and furrow geometry …


Acuta Enews July 1993, Vol. 22, No. 7 Jul 1993

Acuta Enews July 1993, Vol. 22, No. 7

ACUTA Newsletters

In This Issue

Gain-share at Wake Forest

President's Message

North American Numbering Plan

Toll Fraud Checklist

Staff Report


Photoellipsometry Determination Of Surface Fermi Level In Gaas (100), Yi-Ming Xiong, Paul G. Snyder, John A. Woollam Jul 1993

Photoellipsometry Determination Of Surface Fermi Level In Gaas (100), Yi-Ming Xiong, Paul G. Snyder, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Photoellipsometry, a new contactless optical method, is presented, Related to photoreflectance, this method utilizes spectroscopic ellipsometry with the addition of a laser pump beam directed at nearly normal incidence onto the sample surface, where photoexcited electron-hole pairs modify the built-in electric field as a result of the photovoltaic effect. The field-induced changes in the real and imaginary parts of the complex pseudodielectric function can be directly measured, and analyzed in terns of the pump beam power density or the probe beam photon energy to determine parameters, such as surface Fermi level, built-in field strength, depletion depth, broadening, critical point energies, …


A Technical Approach To Groundwater Contamination Problems, Jacqueline C. Burton, Catherine Leser, Candace M. Rose Jun 1993

A Technical Approach To Groundwater Contamination Problems, Jacqueline C. Burton, Catherine Leser, Candace M. Rose

United States Department of Energy: Publications

Argonne National Laboratory has been performing technical investigations at sites in Nebraska and Kansas that have identified groundwater contamination by carbon tetrachloride. This comprehensive program will ultimately provide the affected communities with safe drinking water. The first step in the program is to evaluate the available data and identify sites that will require an Alternate Water Supply Study (AWSS). The objective of the AWSS is to identify options for providing a safe drinking water supply to all users, in compliance with the Safe Drinking Water Act. The AWSS consists of an engineering and cost evaluation followed by implementation of the …


Acuta Enews June 1993, Vol. 22, No. 6 Jun 1993

Acuta Enews June 1993, Vol. 22, No. 6

ACUTA Newsletters

In This Issue

Telemedicine

Vancouver Review

Economy at Turning Point

Yale Meridian Upgrade

Executive Director's Message


Spectroscopic Ellipsometry Studies Of Hf Treated Si (100) Surfaces, Huade Yao, John A. Woollam, Samual A. Alterovitz Jun 1993

Spectroscopic Ellipsometry Studies Of Hf Treated Si (100) Surfaces, Huade Yao, John A. Woollam, Samual A. Alterovitz

Department of Electrical and Computer Engineering: Faculty Publications

Both ex situ and in situ spectroscopic ellipsometry (SE) measurements have been employed to investigate the effects of HF cleaning on Si surfaces. The hydrogeniterminated (H-terminated) Si surface was modeled as an equivalent dielectric layer, and monitored in real time by SE measurements. The SE analyses indicate that after a 20-s 9:l HF dip without rinse, the Si ( 100) surface was passivated by the hydrogen termination and remained chemically stable. Roughness of the HF-etched bare Si (100) surface was observed, in an ultrahigh vacuum (UHV) chamber, and analyzed by the in situ SE. Evidence for desorption of the H-terminated …


Inhibition Of Surface-Related Electrical Breakdown Of Long P+-I-N+ Silicon Structures, F. E. Peterkin, P. F. Williams, B. J. Hankla, L. L. Buresh, S. A. Woodward May 1993

Inhibition Of Surface-Related Electrical Breakdown Of Long P+-I-N+ Silicon Structures, F. E. Peterkin, P. F. Williams, B. J. Hankla, L. L. Buresh, S. A. Woodward

P. F. (Paul Frazer) Williams Publications

Semiconductors such as silicon and GaAs appear attractive for use in high voltage devices because of their high bulk dielectric strength. Typically, however, such devices fail at a voltage well below that expected due to a poorly understood, surface-related breakdown process. In this letter we present empirical results which show that such breakdown of long silicon p+-i-n+ devices can be inhibited by the application of weak visible or near-infrared illumination. These results suggest a technique for avoiding surface flashover in practical high voltage devices, and provide information about the physical mechanisms responsible for initiating …


Acuta Enews May 1993, Vol. 22, No. 5 May 1993

Acuta Enews May 1993, Vol. 22, No. 5

ACUTA Newsletters

In This Issue

Call for Nominations page 2

President's Message page 3

MHEC $aves with Virtual Private Network page 4

Board of Directors Meeting page 5

Tireed Dues page 5

Toll Fraud Takes Aim page 6

Infrastructure page 7

Toll Fraud Checklist page 8

Will My Cellular Phone Fry My Brain? page 9

Executive Director's Message page 11


Reaction Kinetics Analysis Of Urethane Polymerization To Gelation, B Liu, Hossein Noureddini, J S. Dorsey, Delmar C. Timm May 1993

Reaction Kinetics Analysis Of Urethane Polymerization To Gelation, B Liu, Hossein Noureddini, J S. Dorsey, Delmar C. Timm

Papers in Molecular Chemistry

A chemical reaction analysis of a thermosetting, urethane resin formulated from a triol and a diisocyanate is reported. Population density distributions of oligomeric molecules, monomer concentration, the cumulative molar concentration of intramolecular bonds, the resin's average molecular weights, and extent of reaction were determined as a function of time. Rate expressions for intermolecular reactions were first order with respect to the concentration of each reactant and were proportional to the functionality of their respective chemical moieties. Rate expressions for intramolecular reactions were first order with respect to the concentration of the reactant and were proportional to the functionality of the …


Introduction To Electrical Engineering And The Art Of Problem Solving: Volume I, P. Frazer Williams Apr 1993

Introduction To Electrical Engineering And The Art Of Problem Solving: Volume I, P. Frazer Williams

P. F. (Paul Frazer) Williams Publications

These notes were written to accompany a two-semester introductory course in Electrical Engineering. The primary goal of the course is to introduce you to the art of technical problem solving. Conventional Electrical Engineering curricula, in favorable cases at least, produce engineers who are reasonably adept at operating many of the tools important to the field, such as mathematics and circuit analysis. Often, however, these engineers lack skill in choosing which tools to use and in designing a plan of attack to solve problems which are new to them, even though they have all the information and skills needed to fabricate …


Introduction To Electrical Engineering And The Art Of Problem Solving: Volume Ii, P. Frazer Williams Apr 1993

Introduction To Electrical Engineering And The Art Of Problem Solving: Volume Ii, P. Frazer Williams

P. F. (Paul Frazer) Williams Publications

These notes were written to accompany a two-semester introductory course in Electrical Engineering. The primary goal of the course is to introduce you to the art of technical problem solving. Conventional Electrical Engineering curricula, in favorable cases at least, produce engineers who are reasonably adept at operating many of the tools important to the field, such as mathematics and circuit analysis. Often, however, these engineers lack skill in choosing which tools to use and in designing a plan of attack to solve problems which are new to them, even though they have all the information and skills needed to fabricate …