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Articles 1 - 23 of 23

Full-Text Articles in Biomedical Engineering and Bioengineering

Irrigation Soybeans By Growth Stages In Nebraska, N. L. Klocke, Dean E. Eisenhauer, James E. Specht, Roger Wesley Elmore, Gary W. Hergert Sep 1989

Irrigation Soybeans By Growth Stages In Nebraska, N. L. Klocke, Dean E. Eisenhauer, James E. Specht, Roger Wesley Elmore, Gary W. Hergert

Biological Systems Engineering: Papers and Publications

Irrigated soybean production in Nebraska spans a region with diverse soils and climates. Irrigators can easily adopt irrigation scheduling using a stage of growth for timing applications. However, simplifying assumptions, including soil water holding capacity, rainfall, stored soil water, and adequate irrigation system capacity, are implicit in the development of stage of growth irrigation scheduling recommendations. Reliance on these can lead to misapplication of irrigation water.
This project tested irrigation scheduling techniques for indeterminate soybean production in Nebraska, with stage of growth indicating the initiation of irrigation. The range of soils and climate in the study area gave a range ...


A Simplified Equation For Modeling Sediment Transport Capacity, S. C. Finkner, M. A. Nearing, G. R. Foster, John E. Gilley Sep 1989

A Simplified Equation For Modeling Sediment Transport Capacity, S. C. Finkner, M. A. Nearing, G. R. Foster, John E. Gilley

Biological Systems Engineering: Papers and Publications

Sediment transport capacity for shallow overland flow was represented as a quadratic function of downslope distance using the assumption of a linear increase in overland flow discharge with downslope distance and an approximation to the Yalin equation for sediment transport capacity. The simplified equation for sediment transport applies to complex topography having uniform soil and management characteristics. The simplified equation accurately approximated the Yalin equation when calibrated using the average of the hydraulic shear stresses at the end of a constant slope reference profile and the end of the actual profile. The simplified equation is useful in deriving closed-form solutions ...


Measuring The Nanomechanical Properties And Surface Forces Of Materials Using An Atomic Force Microscope, Nancy Burnham, Richard Colton Jun 1989

Measuring The Nanomechanical Properties And Surface Forces Of Materials Using An Atomic Force Microscope, Nancy Burnham, Richard Colton

Nancy A. Burnham

An atomic force microscope(AFM) has been configured so that it measures the force between a tip mounted on a cantilever beam and a sample surface as a function of the tip–surface separation. This allows the AFM to study both the nanomechanical properties of the sample and the forces associated with the tip–surface interaction. More specifically, the AFM can measure the elastic and plastic behavior and hardness via nanoindentation,van der Waals forces, and the adhesion of thin‐film and bulk materials with unprecedented force and spatial resolution. The force resolution is currently 1 nanonewton, and the depth ...


Performance Of Solar-Assisted Modified-Open-Front Swine Nurseries, G. R. Bodman, M. F. Kocher, J. A. Deshazer Jun 1989

Performance Of Solar-Assisted Modified-Open-Front Swine Nurseries, G. R. Bodman, M. F. Kocher, J. A. Deshazer

Biological Systems Engineering: Papers and Publications

Performance data of two modified-open-front non-mechanically ventilated swine nurseries have shown that solar energy can be effectively utilized to maintain a productive environment within the animal space during cold weather (temperatures as low as -26°C ( - 15 °F). The nurseries feature a monoslope roof design and passive collector panels that also function as warm weather ventilation panels. An active solar-heating system uses a ground-level collector operated in conjunction with an in-floor solar heat distribution and storage system. The nurseries were designed to handle pigs weighing from 7 to 23 kg (15 to 50 lb). An average of 19% of the ...


A Non-Invasive Technique For Burn Area Measurement, Jong-Daw Yu May 1989

A Non-Invasive Technique For Burn Area Measurement, Jong-Daw Yu

Theses

The need for a reliable and accurate method for assessing the surface area of burn wounds currently exists in the branch of medicine involved with burn care and treatment. The percentage of the surface area is of critical importance in evaluating fluid replacement amounts and nutritional support during the 24 hours of postburn therapy. A noninvasive technique has been developed which facilitates the measurement of burn area. The method we shall describe is an inexpensive technique to measure the burn areas accurately.

Our imaging system is based on a technique known as structured light. Most structured light computer imaging systems ...


Changes In Expired End-Tidal Carbon Dioxide During Cardiopulmonary Resuscitation In Dogs: A Prognostic Guide For Resuscitation Efforts, Karl B. Kern, Arthur B. Sanders, William D. Voorhees, Charles F. Babbs, Willis A. Tacker, Gordon A. Ewy Apr 1989

Changes In Expired End-Tidal Carbon Dioxide During Cardiopulmonary Resuscitation In Dogs: A Prognostic Guide For Resuscitation Efforts, Karl B. Kern, Arthur B. Sanders, William D. Voorhees, Charles F. Babbs, Willis A. Tacker, Gordon A. Ewy

Weldon School of Biomedical Engineering Faculty Publications

Expired end-tidal carbon dioxide (PCO2) measurements made during cardiopulmonary resuscitation have correlated with cardiac output and coronary perfusion pressure when wide ranges of blood flow are included. The utility of such measurements for predicting resuscitation outcome during the low flow state associated with closed chest cardiopulmonary resuscitation remains uncertain. Expired end-tidal PCO2 and coronary perfusion pressures were measured in 15 mongrel dogs undergoing 15 min of closed chest cardiopulmonary resuscitation after a 3 min period of untreated ventricular fibrillation. In six successfully resuscitated dogs, the mean expired end-tidal PCO2 was significantly higher than that in nine nonresuscitated dogs only after ...


Management Strategies To Minimize And Reduce Soil Compaction, A. J. Jones, R. A. Wiese, Elbert C. Dickey Mar 1989

Management Strategies To Minimize And Reduce Soil Compaction, A. J. Jones, R. A. Wiese, Elbert C. Dickey

Biological Systems Engineering: Papers and Publications

Nature has some built-in processes that reduce soil compaction. They include cycles of wetting and drying, and freezing and thawing.

In the last 20 to 30 years, farming practices have changed drastically. These farming changes have made it more difficult for nature to rejuvenate the soil environment to an optimum condition for crops. Performing field operations on wet soils, using multiple field operations to grow the same crop continuously, and eliminating meadow crops from crop rotations contribute to more extensive and deeper compaction.

Each farmer has the opportunity to make decisions that can keep soils from becoming compacted.

Adoption of ...


Evaluation Of Irrigation Planning Decisions, Derrel L. Martin, James R. Gilley, Raymond J. Supalla Feb 1989

Evaluation Of Irrigation Planning Decisions, Derrel L. Martin, James R. Gilley, Raymond J. Supalla

Biological Systems Engineering: Papers and Publications

A method is developed to determine optimal irrigation strategies for a single season using crop production functions which incorporate physically based coefficients. The relationship of yield to evapotranspiration is used to develop the yield-irrigation function. The physical parameters used in the production function can be determined from field measurements or various types of computer simulation. Using this approach, the optimal irrigated area and depth of water to apply can be related to prices, costs, and physical parameters. This produces a more general solution than commonly used production functions that depend on limited experimental results. The optimal irrigation depth and irrigated ...


Scatchard Analysis Of Methane Sulfinic Acid Production From Dimethyl Sulfoxide: A Method To Quantify Hydroxyl Radical Formation In Physiologic Systems, Charles F. Babbs, David W. Griffin Jan 1989

Scatchard Analysis Of Methane Sulfinic Acid Production From Dimethyl Sulfoxide: A Method To Quantify Hydroxyl Radical Formation In Physiologic Systems, Charles F. Babbs, David W. Griffin

Weldon School of Biomedical Engineering Faculty Publications

A major impediment to the confirmation of free radical mechanisms in pathogenesis is a lack of direct, chemical evidence that oxygen centered free radicals actually arise in living tissues in quantities sufficient to cause serious damage. This investigation was conducted to validate the use of dimethyl sulfoxide (DMSO) as a quantitative molecular probe for the generation of hydroxyl radicals (HO*) under physiologic conditions. Reaction of HO* with DMSO produces methane sulfinic acid (MSA) as a primary product, which can be detected by a simple colorimetric assay. To develop a method for estimating total HO* production, we studied two model systems ...


Lethal Hydroxyl Radical Production In Paraquat-Treated Plants, Charles F. Babbs, Jo Ann Pham, Ronald C. Coolbaugh Jan 1989

Lethal Hydroxyl Radical Production In Paraquat-Treated Plants, Charles F. Babbs, Jo Ann Pham, Ronald C. Coolbaugh

Weldon School of Biomedical Engineering Faculty Publications

Bipyridinium herbicides, including paraquat and diquat, are believed to act by generating highly reactive, oxygen-centered free radicals within chloroplasts when treated plants are exposed to sunlight. This hypothesis has not yet been confirmed by direct chemical measurements of specific free radicals. We studied paraquat-treated plants using a new method able to detect and quantify formation of highly reactive and deleterious hydroxyl radicals (HO*), in which dimethyl sulfoxide (DMSO) is used as a molecular probe. DMSO is oxidized by HO* to form the stable, nonradical compound, methane sulfinic acid, which can be easily extracted from plant tissue and measured spectrophotometrically. Initial ...


Effect Of Oxygen Concentration On The Formation Of Malondialdehyde-Like Material In A Model Of Tissue Ischemia And Reoxygenation, Steven C. Salaris, Charles F. Babbs Jan 1989

Effect Of Oxygen Concentration On The Formation Of Malondialdehyde-Like Material In A Model Of Tissue Ischemia And Reoxygenation, Steven C. Salaris, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This study was conducted to explore the functional relationship between oxygen concentration during tissue reoxygenation after ischemia and the extent of postischemic lipid peroxidation, an indicator of reoxygenation injury. Excised rat liver or kidney tissue was rendered ischemic for 1 h at 37°C, minced into 1 mm3 fragments, and then reoxygenated for 1 h in flasks of buffered salt solution containing various amounts of oxygen. Production of malondialdehyde-like material (MDA) was measured to indicate lipid peroxidation. MDA production was minimal at oxygen tensions less than 10 mmHg, increased sharply from 10 to 50 mmHg, and plateaued at approximately 100 ...


Quantitative Effects Of Iron Chelators On Hydroxyl Radical Production By The Superoxide-Driven Fenton Raction, Jean Blair Smith, Joanne C. Cusumano, Charles F. Babbs Jan 1989

Quantitative Effects Of Iron Chelators On Hydroxyl Radical Production By The Superoxide-Driven Fenton Raction, Jean Blair Smith, Joanne C. Cusumano, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Iron bound to certain chelators is known to promote the conversion of superoxide radicals (O2) to hydroxyl radicals (HO') by the superoxide-driven Fenton reaction. The production of HO' by various iron chelates was studied using the reaction of dimethyl sulfoxide and HO' to produce methane sulphinic acid. Methane sulphinic acid was quantified by use of a simple colorimetric assay and used to determine the amounts of HO' produced. Superoxide was generated from 200 M hypoxanthine and 0.05 U/ml xanthine oxidase in the presence of 0-100 M iron and 100 M of each chelator. The results of this preliminary ...


Organ Doses In Routine Radiographic Procedures, Yang Han Jan 1989

Organ Doses In Routine Radiographic Procedures, Yang Han

Theses and Dissertations

There is general agreement that the extent of the risk from x-ray examination is related in some way to the radiation dose. As the dose increases, the likelihood of significant biological effects also increases. If a clear correlation between dose and effect is to be established, a convenient and reasonably accurate method of estimating patient’s absorbed doses during common radiographic examinations will be highly needed. A simple method is developed in this project to determine the two important parameters e exposure at skin entrance (ESE) and half value layer (IIVL), which is essential to get reasonably accurate estimates of ...


The Competitive Effects Of Medroxyprogesterone Acetate (Mpa) In Vitro And In Vivo On Hypothalmic Androgen Binding In Cf-L Male Mice, Michael Patrick Perry Jan 1989

The Competitive Effects Of Medroxyprogesterone Acetate (Mpa) In Vitro And In Vivo On Hypothalmic Androgen Binding In Cf-L Male Mice, Michael Patrick Perry

Theses and Dissertations

No abstract provided.


Ultrasonic Attenuation Estimation For Tissue Characterization, Viren R. Amin Jan 1989

Ultrasonic Attenuation Estimation For Tissue Characterization, Viren R. Amin

Retrospective Theses and Dissertations

No abstract provided.


Hydrogel Ocular Inserts For The Treatment Of Infectious Bovine Keratoconjunctivitis , Je-Phil Ryoo Jan 1989

Hydrogel Ocular Inserts For The Treatment Of Infectious Bovine Keratoconjunctivitis , Je-Phil Ryoo

Retrospective Theses and Dissertations

Hydrogel coated ring shaped ocular inserts (containing the antibiotic, tylosin tartrate) were used in an evaluation of the effectiveness of polymeric ocular drug release devices for treating infectious bovine keratoconjunctivitis. Two major in vivo tests were done: a treatment test using infected cattle and a test to evaluate ring retention characteristics. The in vivo experiments represent the first experiments using hydrogel ocular inserts containing an antibiotic for treating infectious bovine keratoconjunctivitis;The bacterium, Moraxella bovis, was used to replicate the disease. In the infection tests, ten calves were challenged with 2.4 x 10[superscript]8 - 1.6 x 10 ...


Surface Cover Provided By Selected Legumes, John E. Gilley, J. F. Power, P. J. Reznicek, S. C. Finkner Jan 1989

Surface Cover Provided By Selected Legumes, John E. Gilley, J. F. Power, P. J. Reznicek, S. C. Finkner

Biological Systems Engineering: Papers and Publications

The use of legumes in conservation tillage systems may yield several benefits including reduced erosion resulting from establishment of surface cover. The effectiveness in furnishing surface cover of 18 plant species seeded on three different dates was evaluated over an 11-month period. For several of the legume species, planting date significantly influenced maximum surface cover and the number of days required to reach maximum cover. For each of the planting dates, hairy vetch achieved maximum cover as rapidly as any other legume and maintained the greatest cover throughout the study period. Relationships for estimating legume surface cover from vegetative mass ...


Enhancing The Adoption Of Soil Conservation Practices With Targeted Educational Programs, David P. Shelton, Elbert C. Dickey, Paul J. Jasa, David A. Biere Jan 1989

Enhancing The Adoption Of Soil Conservation Practices With Targeted Educational Programs, David P. Shelton, Elbert C. Dickey, Paul J. Jasa, David A. Biere

Biological Systems Engineering: Papers and Publications

Two independent, but closely related, grant funded educational programs have been developed and implemented to reduce soil erosion in selected areas of eastern Nebraska, U.S.A. Traditional extension programming methods as well as other more nontraditional approaches have been extensively used. In one program, encompassing 220,000 ha of cropland, annual soil erosion has been reduced by 2.5 Mt and annual fuel savings of 1.5 ML have been achieved through a reduction in the number of tillage operations. During a one-year period in the second project, more than 81,000 m of terraces were constructed, which resulted ...


Determining Crop Residue Cover With Electronic Image Analysis, Elbert C. Dickey, David P. Shelton, G.E. Meyer, K.T. Fairbanks Jan 1989

Determining Crop Residue Cover With Electronic Image Analysis, Elbert C. Dickey, David P. Shelton, G.E. Meyer, K.T. Fairbanks

Biological Systems Engineering: Papers and Publications

Crop residue management is one of the best and most efficient soil conservation methods available to farmers. Determinations of the percentage of the soil surface covered with crop residue are often needed for: soil conservation research; erosion control demonstrations; and maintaining compliance with federal, state, or local soil conservation regulations. A number of methods can be used to estimate residue cover, however, many have limitations. To help overcome some of these limitations, a technique, which uses readily-available microcomputer-related hardware and standard video camera equipment has been developed to estimate crop residue cover from photographic slides. This procedure is relatively rapid ...


Performance And Design Of Vegetative Filters For Feedlot Runoff Treatment, Elbert C. Dickey, D. H. Vanderholm Jan 1989

Performance And Design Of Vegetative Filters For Feedlot Runoff Treatment, Elbert C. Dickey, D. H. Vanderholm

Biological Systems Engineering: Papers and Publications

Installation of a zero-discharge, runoff-control system is one method for solving potential water pollution problems from many feedlot operations. Even though the zero-discharge system is required by regulation in several states, this approach may be economically prohibitive for many small operations. An alternative is to install a vegetative filter system to adequately control the runoff so that violations of water quality standards will not occur during storm runoff. Vegetative filters are systems in which a vegetative area such as pasture, grassed waterways, or even cropland is used for treating feedlot runoff by settling, filtration, dilution, adsorption of pollutants and infiltration ...


The Cost Of Misapplication Of Herbicides, Robert Grisso, Elbert C. Dickey, Larry D. Schulze Jan 1989

The Cost Of Misapplication Of Herbicides, Robert Grisso, Elbert C. Dickey, Larry D. Schulze

Biological Systems Engineering: Papers and Publications

A field survey of 103 private herbicide applicators was conducted during the spring of 1986 in 12 central and eastern Nebraska counties. The results showed that only 30% of the cooperators were applying herbicides within 5% of their intended application rate. Twenty-six percent of the cooperators over-applied herbicides during a single application, with an average cost due to misapplication of $3.11/ha ($1.26/a). If these values were extended over Nebraska, $4.26 million are expended for extra herbicides which were not necessary. The average cost of over application was in excess of $570 per application. Forty-four percent ...


Germ Weight, Germ Oil Content, And Estimated Oil Yield For Wet-Milled Yellow Dent Corn As Affected By Moisture Content At Harvest And Temperature Of Drying Air, Curtis L. Weller, Marvin R. Paulsen, Stephen Mbuvi Jan 1989

Germ Weight, Germ Oil Content, And Estimated Oil Yield For Wet-Milled Yellow Dent Corn As Affected By Moisture Content At Harvest And Temperature Of Drying Air, Curtis L. Weller, Marvin R. Paulsen, Stephen Mbuvi

Biological Systems Engineering: Papers and Publications

A split-plot experimental design was used to determine the effect of moisture content at harvest and temperature of drying air on weight, oil content, and estimated oil yield of corn germs recovered from laboratory wet milling. The effects were determined for a high-yielding hybrid of yellow dent corn widely grown in the corn belt that was hand-picked and hand-shelled. Germ oil content decreased significantly as moisture content at harvest and temperature of drying air increased. Germ weight and estimated oil yield generally decreased as both moisture content at harvest and temperature of drying air increased from 17.2 to 29 ...


Design Of A Portable Microprocessor-Based International Phonetic Alphabet (Ipa) Text-To-Speech Conversion Device For Use By The Speech Impaired , Dexter Katsutoshi Ishii Jan 1989

Design Of A Portable Microprocessor-Based International Phonetic Alphabet (Ipa) Text-To-Speech Conversion Device For Use By The Speech Impaired , Dexter Katsutoshi Ishii

Retrospective Theses and Dissertations

A portable microprocessor-based alternate communication device was designed and a prototype fabricated. This device allows speech impaired individuals, whose language skills remain intact, to input and edit an utterance of unrestricted vocabulary via a keyboard/LCD display system. The utterance, which is specified using the International Phonetic Alphabet (IPA), is then converted into an appropriate set of speech synthesizer parameters, using context sensitive rules. An interrupt driven system is used to pass each set of parameters, in order and at the appropriate time, to the synthesizer, thus generating an audible output;Tests conducted using the device in its present state ...