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Biomedical Engineering and Bioengineering Commons™

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1987

Articles 1 - 13 of 13

Full-Text Articles in Biomedical Engineering and Bioengineering

Nebraska's Modified-Open-Front Farrowing Houses Design And Operation, Gerald R. Bodman, Donald G. Levis, Duane E. Reese Nov 1987

Nebraska's Modified-Open-Front Farrowing Houses Design And Operation, Gerald R. Bodman, Donald G. Levis, Duane E. Reese

Biological Systems Engineering: Papers and Publications

Two modified-open-front non-mechanically ventilated farrowing houses with creep boxes were operated over a two year period. Annual energy requirements were in the range of 10.6 to 10.9 cents per crate per day. No adverse effects on pig performance were realized. In most instances pig performance exceeded national standards of excellent performance—survival rates in excess of 90% and 21-day pig weights of 5.9 to 6.8 kg (13 to 15 lb). The study verified that another alternative is available to producers who do not want additional mechanical equipment to operate and maintain.

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Size Distribution Of Sediment As Affected By Surface Residue And Slope Length, John E. Gilley, S. C. Finkner, G. E. Varvel Sep 1987

Size Distribution Of Sediment As Affected By Surface Residue And Slope Length, John E. Gilley, S. C. Finkner, G. E. Varvel

Biological Systems Engineering: Papers and Publications

Runoff samples for determination of size distribution of sediment were collected under simulated rainfall conditions at selected downslope distances on plots covered with sorghum and soybean residue at rates ranging from 0.00 to 6.73 t/ha . The effects of surface residue and slope length on size distribution of sediment were evaluated. Substantial movement of sediment in the form of aggregates was found for each of the residue treatments. Significant differences in size distribution of sediment occurred between residue treatments. For a given residue rate, differences in sediment size distribution were found between sorghum and soybean residue. Size distribution of sediment …

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Electron Beam Effects In The Analysis Of Compound Semiconductors And Devices, Nancy Burnham, Ll Kazmerski, Ab Swartzlander, Aj Nelson, Se Asher Aug 1987

Electron Beam Effects In The Analysis Of Compound Semiconductors And Devices, Nancy Burnham, Ll Kazmerski, Ab Swartzlander, Aj Nelson, Se Asher

Nancy A. Burnham

The effects of electron beams on the analysis of CuInSe2surfaces are examined in this paper. Potential changes in the surface chemistry—including oxidation and desorption—under a range of incident probe conditions, are investigated for possible artifactual information generation. Emphasis is placed on the relationships between beam conditions and oxygen chemisorption and physisorption, since oxygen treatments of devices utilizing this semiconductor are critical to performance. Single crystals and polycrystalline thin films are analyzed and compared to establish the beam‐induced phenomena.

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Electron Energy‐Loss Spectroscopy Study Of Hydrogenated Amorphous Silicon, Nancy Burnham, Rf Fisher, Se Se, Ll Kazmerski Jun 1987

Electron Energy‐Loss Spectroscopy Study Of Hydrogenated Amorphous Silicon, Nancy Burnham, Rf Fisher, Se Se, Ll Kazmerski

Nancy A. Burnham

Electron energy‐loss spectroscopy is used to study hydrogenated amorphous silicon (a‐Si:H). Core‐level and plasma excitations were examined as a function of hydrogen content. This technique and its interpretation reveals a consistent picture of the electron excitations within this important material. The a‐Si:H thin films were fabricated by rf sputtering. Their hydrogen concentrations ranged from 0% to 15%. Hydrogen content was determined by infrared spectroscopy and secondary ion mass spectroscopy. X‐ray photoelectron spectroscopy and inspection of the silicon Auger‐K L L peak confirmed the silicon core levels.

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Human Health Effects Assays, Ronald C. Sims, J. L. Sims, R. R. Dupont Jan 1987

Human Health Effects Assays, Ronald C. Sims, J. L. Sims, R. R. Dupont

Biological Engineering Faculty Publications

Health risk assessment of individual environmental chemicals, risks of drinking water supplies, methods for evaluating toxicity, and structure-activity relationships and response-surface methodology represent the focus for 1986. A report of the Steering Committee on Identification of Toxic and Potentially Toxic Chemicals for Consideration by the National Toxicology Pro gram found that, for the majority of substances they examined, data essential for human health hazard assessment were lacking.1 Milestone publications concerning human health effects aspects include works by Mortelmans et al,2 Busch et al,3 Hartman et al,4 Rein,5 Gentile,6 Hodgson,7 and Tagashira and Omura. …

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Colorimetric Assay For Methanesulfinic Acid In Biological Samples, Charles F. Babbs, Melissa J. Gale Jan 1987

Colorimetric Assay For Methanesulfinic Acid In Biological Samples, Charles F. Babbs, Melissa J. Gale

Weldon School of Biomedical Engineering Faculty Publications

We describe a simple colorimetric method to measure 30 to 300 M concentrations of sulfinic acids in biologic samples. The procedure employs the coupling reaction of an aromatic diazonium salt (Ar-N=N+) with the sulfinic acids (RSOOH) to produce a colored diazosulfone derivative (Ar-N=N-SOOR), which can be selectively extracted into an organic solvent. Linearity and noninterference by liver homogenate, phenols, amines, and thousand-fold or greater excesses of sulfate, thiol, and dimethyl sulfoxide are demonstrated. Sensitivity of the method is about 10 nmol per sample. Because methanesulfinic acid is the principal product of the action of hydroxyl radicals upon dimethyl sulfoxide, and …

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Protection From Reperfusion Injury In The Isolated Rat Heart By Postischaemic Deferoxamine And Osypurinol Administration, Stephen F. Badylak, Abby Simmons, John Turek, Charles F. Babbs Jan 1987

Protection From Reperfusion Injury In The Isolated Rat Heart By Postischaemic Deferoxamine And Osypurinol Administration, Stephen F. Badylak, Abby Simmons, John Turek, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The Langendorff isolated rat heart preparation was used to determine the effect of oxypurinol, a xanthine oxidase inhibitor, and deferoxamine, an iron binding agent, on the extent of myocardial reperfusion injury after 60 minutes of ischaemia. Thirty rats were divided into three groups of 10. and an isolated heart preparation made from each rat. The isolated hearts were perfused for 15 minutes with a modified Krebs-Henseleit perfusate solution to permit stabilisation of the preparation. Each heart was then subjected to 60 minutes of total ischaemia at 37°C followed by 60 minutes of reperfusion with either saline treated perfusate, oxypurinol treated …

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A Mathematical Model For The Fate Of Hazardous Substances In Soil: Model Description And Experimental Results, W. Greeney, C. Caupp, Ronald C. Sims Jan 1987

A Mathematical Model For The Fate Of Hazardous Substances In Soil: Model Description And Experimental Results, W. Greeney, C. Caupp, Ronald C. Sims

Biological Engineering Faculty Publications

A mathematical model (VIP) was developed and implemented for evaluating the fate of a hazardous substance in the unsaturated zone of the soil. The model simulates vadose zone processes including volatilization, degradation, adsorption/desorption, advection, and dispersion. Four physical phases in the vadose zone are considered including water, oil, soil grains, and soil-pore air (unsaturated pore space). The Vadose Zone Interactive Processes (VIP) model is appropriate for sites under RCRA and CERCLA (Superfund) categorization since site-specific soil-waste processes affecting transport of hazardous chemicals through the vadose zone are incorporated in the model. A RCRA land treatment system was chosen as the …

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The Effect Of Temperature On Polycyclic Aromatic Hydrocarbon Persistence In An Unacclimated Agricultural Soil, M. P. Coover, Ronald C. Sims Jan 1987

The Effect Of Temperature On Polycyclic Aromatic Hydrocarbon Persistence In An Unacclimated Agricultural Soil, M. P. Coover, Ronald C. Sims

Biological Engineering Faculty Publications

A laboratory study was conducted to investigate the effect of temperature on the persistence of polycyclic aromatic hydrocarbons (PAHs) incubated in an unacclimated agricultural sandy loam soil. Soil microcosms were spiked with 16 priority pollutant PAHs and placed in incubation chambers at 10, 20, and 30°C. Triplicate sets of microcosms at each temperature were periodically removed from incubation over the 240 day study period and solvent extracted. Concentrations of PAHs in the soil were determined by HPLC analysis of the extracts. Substantial loss of three-ring compounds was observed at all temperatures whereas there was very little apparent loss of five …

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Conservation Tillage: Perceived And Actual Use, Elbert C. Dickey, Paul J. Jasa, Bryn J. Dolesh, Lisa A. Brown, S. Kay Rockwell Jan 1987

Conservation Tillage: Perceived And Actual Use, Elbert C. Dickey, Paul J. Jasa, Bryn J. Dolesh, Lisa A. Brown, S. Kay Rockwell

Biological Systems Engineering: Papers and Publications

A mail survey of farmers in Nebraska showed their perceived use of conservation tillage was about 55%. However, using the 30% residue cover criterion that the Conservation Tillage Information Center uses to define conservation tillage, a field survey of seven counties in 1984 showed that actual use of conservation tillage was less than 5%. Fewer than 20% of the producers surveyed had more than 20% residue cover remaining after tillage and planting. The field survey also showed disk tillage systems were used by almost 70% of the producers. The moldboard plow was used by only 15% of the producers, thus …

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Slope Length And Surface Residue Influences On Runoff And Erosion, John E. Gilley, S. C. Finkner, G. E. Varvel Jan 1987

Slope Length And Surface Residue Influences On Runoff And Erosion, John E. Gilley, S. C. Finkner, G. E. Varvel

Biological Systems Engineering: Papers and Publications

Runoff rate, runoff velocity , sediment concentration and soil loss rate of rills or overland flow channels were measured at selected downslope distances on plots with varying rates of sorghum and soybean residue, runoff rate, runoff velocity and soil loss rate usually increased with downslope distance. In general, the presence of greater amounts of crop residue reduced sediment concentration and soil loss rate along the entire slope length. Substantial variations in runoff rate, runoff velocity, sediment concentration and soil loss rate were found with downslope distance on some residue treatments.

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The Rate Of Benzo[A]Pyrene Apparent Loss In A Natural And Manure Amended Clay Loam Soil, M. P. Coover, Ronald C. Sims Jan 1987

The Rate Of Benzo[A]Pyrene Apparent Loss In A Natural And Manure Amended Clay Loam Soil, M. P. Coover, Ronald C. Sims

Biological Engineering Faculty Publications

A study was conducted to evaluate the rate of Benzo[a]pyrene apparent loss from a previously uncontaminated agricultural clay loam soil and to determine the effect of cow manure, as organic substrate amendment, on B[a]P apparent loss. Soil microcosms were spiked with 10 μg/g B[a]P and incubated at 20°C. Triplicate sets of microcosms were periodically removed from incubation and solvent extracted. Concentrations of B[a]P in the soil were determined by HPLC analysis of the extracts. Under the conditions of this study manure was an ineffective amendment for increasing the rate of B[a]P apparent loss in the Durant clay loam soil. In …

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Slot Injection Of Herbicides, Paul J. Jasa, Elbert C. Dickey, Thomas R. Peterson Jan 1987

Slot Injection Of Herbicides, Paul J. Jasa, Elbert C. Dickey, Thomas R. Peterson

Biological Systems Engineering: Papers and Publications

Injection of thiocarbamate herbicides into a slot created by a coulter was evaluated during a 3-year study in southeastern Nebraska. Control of shattercane, the dominant weed, with the slot injector was similar to conventional double disk incorporation. In both tilled and untilled surface conditions, the slot injector placed the herbicide into the soil with minimal disturbance of the soil and residue. Herbicides which are normally broadcast applied were band applied, reducing chemical costs by two-thirds.

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