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Articles 1 - 19 of 19

Full-Text Articles in Biomedical Engineering and Bioengineering

Irradiation-Hyperthermia In Canine Hemangiopericytomas: Large-Animal Model For Therapeutic Response, Ralph C. Richardson, Virgil L. Anderson, William D. Voorhees, William E. Blevins, Tammy K. Inskeep, Wolfgang Janas, Robert E. Shupe, Charles F. Babbs Nov 1984

Irradiation-Hyperthermia In Canine Hemangiopericytomas: Large-Animal Model For Therapeutic Response, Ralph C. Richardson, Virgil L. Anderson, William D. Voorhees, William E. Blevins, Tammy K. Inskeep, Wolfgang Janas, Robert E. Shupe, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Results of irradiation-hyperthermia treatment in 11 dogs with naturally occurring hemangiopericytomas are reported. Similarities of canine and human hemangiopericytomas are described. Orthovoltage X-irradiation followed by microwaveinduced hyperthermia resulted in a 91% objective response rate. A statistical procedure was given to evaluate quantitatively the clinical behavior of locally invasive, nonmetastatic tumors in dogs that were undergoing therapy for control of local disease. The procedure used a small sample size and demonstrated distribution of the data on a scaled response as well as transformation of the data through classical parametric and nonparametric statistical methods. These statistical methods set confidence limits on the ...


Model And Production Function For Irrigation Management, Derrel L. Martin, Darrell G. Watts, James R. Gilley Jun 1984

Model And Production Function For Irrigation Management, Derrel L. Martin, Darrell G. Watts, James R. Gilley

Biological Systems Engineering: Papers and Publications

A simulation model was developed to estimate the effect of deficit irrigation upon crop yield. The model was designed to provide relative yield estimates for numerous combinations of irrigation system, crop growth and irrigation management parameters. A daily soil moisture balance was used to predict evaporation and transpiration from which crop yields were estimated. Gross irrigation water requirements were estimated from net irrigation requirements, irrigation efficiencies, irrigation system limitations, and effective rainfall. Crop production functions that use physically defined parameters were also developed to relate crop yields to gross irrigation requirements. The production functions worked well on a limited test ...


Suitability Of Reduced Pressure Center-Pivots, John E. Gilley Apr 1984

Suitability Of Reduced Pressure Center-Pivots, John E. Gilley

Biological Systems Engineering: Papers and Publications

Selection criteria for reduced pressure center-pivot irrigation systems are developed. An analysis of the combined effects of the application rate characteristics or center-pivot irrigation systems and the Soil Conservation Service (SCS) soil intake family curves is used to determine the maximum depth of water which could be applied per irrigation for various types of soils and sprinkler packages. These irrigation depths are used to determine guidelines for proper selection of reduced pressure center-pivot systems. The results can be used as a general guide to determine if a particular system may have a runoff problem under a given situation.


Regional Blood Flow During Cardiopulmonary Resuscitation With Abdominal Counterpulsation In Dogs, William D. Voorhees Iii, Sandra H. Ralston, Charles F. Babbs Jan 1984

Regional Blood Flow During Cardiopulmonary Resuscitation With Abdominal Counterpulsation In Dogs, William D. Voorhees Iii, Sandra H. Ralston, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The addition of abdominal counterpulsation to standard cardiopulmonary resuscitation (IAC-CPR) during ventricular fibrillation has been shown to improve cardiac output, oxygen uptake, and central arterial blood pressure in dogs. The present study was performed to determine the effect of IAC-CPR on regional blood flow. Regional blood flow was measured with radioactively labeled microspheres during sinus rhythm and during alternate periods of IAC-CPR and standard CPR (STD-CPR) in nine dogs anesthetized with pentobarbital. Blood pressures and oxygen uptake were measured continuously. As in previous studies, diastolic arterial pressure was higher (30.8%) during IAC-CPR than during STD-CPR, as were cardiac output ...


Abnormal Response Of Tumor Vasculature To Vasoactive Drugs, Rosanna C. Chan, Charles F. Babbs, Richard J. Vetter, Carlton H. Lamar Jan 1984

Abnormal Response Of Tumor Vasculature To Vasoactive Drugs, Rosanna C. Chan, Charles F. Babbs, Richard J. Vetter, Carlton H. Lamar

Weldon School of Biomedical Engineering Faculty Publications

The effects of the vasoconstrictor, phenylephrine, and the vasodilator, hydralazine, on blood flow to tumor were studied and compared to those on blood flow to normal tissues in vivo. Regional blood flow and cardiac output were measured with the use of radioactive microspheres in 150- to 250 g inbred Harlan F344 rats bearing subcutaneous nodules of two types of transplantable carcinoma ("hard" and "soft") with microscopically different vascular patterns. Three groups of rats were treated with hydralazine, saline, or phenylephrine, and regional blood flow was determined at the time of maximum blood pressure response. Results were correlated with quantitative morphometric ...


Theoretical Advantages Of Abdominal Counterpulsation In Cpr As Demonstrated In A Simple Electrical Model Of The Circulation, Charles F. Babbs, Sandra H. Ralston, Leslie A. Geddes Jan 1984

Theoretical Advantages Of Abdominal Counterpulsation In Cpr As Demonstrated In A Simple Electrical Model Of The Circulation, Charles F. Babbs, Sandra H. Ralston, Leslie A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

Animal studies and preliminary clinical observations suggest that the addition of interposed abdominal compressions (IAC) to ventilation and chest compression of standard cardiopulmonary resuscitation (CPR) augments blood flow, blood pressures, and immediate survival. To investigate the physical basis for enhanced circulation during IAC-CPR, we developed an electrical model of the circulation. Heart and blood vessels were modeled as resistive-capacitive networks, pressures as voltages, blood flow as electric current, blood inertia as inductance, and the cardiac and venous valves as diodes. External pressurization of the heart and great vessels, as would occur in CPR, was simulated by application by half-sinusoidal voltage ...


Preclinical Studies Of Abdominal Counterpulsation In Cpr, Charles F. Babbs Jan 1984

Preclinical Studies Of Abdominal Counterpulsation In Cpr, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Abdominal counterpulsation added to standard cardiopulmonary resuscitation improves blood flow in animal models when compared to chest compressions alone. Similar effects can be demonstrated in analog and digital computer models of the circulation. The technique generates both central aortic and central venous pressure pulses, and successful application of the method depends on maximizing the former and minimizing the latter. Proper technique is important in order to generate the largest possible arteriovenous pressure difference.


An Experimental Circulatory Arrest Model In The Rat To Evaluate Calcium Antagonists In Cerebral Resuscitation, Lawrence De Garavilla, Charles F. Babbs, Willis A. Tacker Jan 1984

An Experimental Circulatory Arrest Model In The Rat To Evaluate Calcium Antagonists In Cerebral Resuscitation, Lawrence De Garavilla, Charles F. Babbs, Willis A. Tacker

Weldon School of Biomedical Engineering Faculty Publications

A circulatory arrest model in the rat was developed for use in cerebral and cardiac resuscitation studies. Whole-body ischemia was produced for 8 to 18 minutes by arresting the heart with a cold potassium chloride cardioplegic solution. Following cardiopulmonary resuscitation, minimal, standardized intensive care was provided. As the duration of ischemia was increased from 8 to 18 minutes, survival immediately following resuscitation decreased from 100% to 25%, and survival at 48 hours after ischemia decreased from 80% to 0%. Thirty per cent of the rats recovering from 11 minutes of ischemia suffered motor seizures. Survival and the incidence of motor ...


Efficacy And Safety Of The Reciprocal Pulse Defibrillator Current Waveform, M J. Niebauer, Charles F. Babbs, L A. Geddes, J D. Bourland Jan 1984

Efficacy And Safety Of The Reciprocal Pulse Defibrillator Current Waveform, M J. Niebauer, Charles F. Babbs, L A. Geddes, J D. Bourland

Weldon School of Biomedical Engineering Faculty Publications

The efficacy and safety of a new defibrillating current waveform, consisting of a low-tilt 5 ms trapezoidal pulse followed closely by a second identical pulse of opposite polarity, was tested m seven isolated, perfused, working canine hearts suspended in an isoresistive, isosmotic shock bath at 37 oC. The efficacy and safety of the reciprocal pulse was compared with a single 5 ms pulse, a single 10 ms pulse, and a dual (unidirectional) 5 ms pulse waveform. The mean threshold average current densities for the 5 ms single pulse, 10 ms single pulse, dual 5 ms pulse, and reciprocal pulse (absolute ...


Cardiac, Thoracic, And Abdominal Pump Mechanisms In Cardiopulmonary Resuscitation: Studies In An Electrical Model Of The Circulation, Charles F. Babbs, Christopher Weaver, Sandra H. Ralston, Leslie A. Geddes Jan 1984

Cardiac, Thoracic, And Abdominal Pump Mechanisms In Cardiopulmonary Resuscitation: Studies In An Electrical Model Of The Circulation, Charles F. Babbs, Christopher Weaver, Sandra H. Ralston, Leslie A. Geddes

Weldon School of Biomedical Engineering Faculty Publications

To investigate alternative mechanisms generating artificial circulation during cardiopulmonary resuscitation (CPR), an electrical model of the circulation was developed. Heart and blood vessels were modeled as resistive-capacitive networks; pressures in the chest, abdomen, and vascular compartments as voltages; blood flow as electric current; blood inertia as inductance; and the cardiac and venous valves as diodes. External pressurization of thoracic and abdominal vessels, as would occur in CPR, was simulated by application of half-sinusoidal voltage pulses. Three modes of creating artificial circulation were studied: cardiac pump (CP), in which the atria and ventricles of the model were pressurized simultaneously; thoracic pump ...


Intrapulmonary Epinephrine During Prolonged Cardipulmonary Resuscitation: Improved Regional Blood Flow And Resuscitation In Dogs, Sandra H. Ralston, William D. Voorhees, Charles F. Babbs Jan 1984

Intrapulmonary Epinephrine During Prolonged Cardipulmonary Resuscitation: Improved Regional Blood Flow And Resuscitation In Dogs, Sandra H. Ralston, William D. Voorhees, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Blood flow to vital organs was measured at five-minute intervals during 20 minutes of cardiopulmonary resuscitation (CPR) and ventricular fibrillation in two groups of anesthetized dogs (n = 15 per group). The relationship between organ blood flow and restoration of circulation after 20 minutes was assessed with no additional treatment in Group I and with intrapulmonary epinephrine in Group II. Cardiac output and organ blood flow did not vary significantly in Group I. In Group II, intrapulmonary epinephrine significantly improved blood flow to the myocardium, the brain, and the adrenal glands. A mean myocardial blood flow of less than 0.13 ...


The Use Of Computer-Assisted Experiments In The Canine To Support The Development Of A Mathematical Model For The Hepatic Removal Of Indocyanine Green Dye Under Normal And Reduced Hepatic Blood Flow Conditions , Paul Joseph Antol Jan 1984

The Use Of Computer-Assisted Experiments In The Canine To Support The Development Of A Mathematical Model For The Hepatic Removal Of Indocyanine Green Dye Under Normal And Reduced Hepatic Blood Flow Conditions , Paul Joseph Antol

Retrospective Theses and Dissertations

Sixteen mongrel dogs were tested for hepatic removal of indocyanine green (ICG) dye in normal animals and animals with portal-caval shunts. Characteristics of blood ICG clearance and bile ICG accumulation were studied. Response of the mathematical model is similar to the response from the studies of normal animals when programmed with initial parameters taken from the animal studies. A data-handling system was developed for the acquisition of the experimental data. Cardiac output decreased two-fold (p < 0.01) following a portal-caval shunt. Dye decay rate in the plasma decreased (p < 0.05) which resulted in an increase in area under the blood concentration curve and time to zero concentration in the shunted animals. Mean bile flow was reduced two-fold (p < 0.05) while the area under the ascending bile curve increased (p < 0.05) in the shunted animals. A method in which to measure the volume of the bile canalicular space has been discovered by analysis of the descending portion of the bile dye curve. Effects of methoxyfluorane-nitrous oxide anesthetic on the hepatic system appear to be minimal with respect to dye clearance as seen by relatively small differences between the animal data and the mathematical model.


Laboratory Wet Milling Of Ensiled Corn Kernels, A. Neryng, Peter J. Reilly Jan 1984

Laboratory Wet Milling Of Ensiled Corn Kernels, A. Neryng, Peter J. Reilly

Chemical and Biological Engineering Publications

Dried and ensiled corn were each steeped with aqueous SO2 or water at initial pHs of 4-5; both were also steeped with aqueous SO2 at pH7. Initial steepwater composition or pH had less effect on yields of individual fractions and recoveries of various components than did differences between dried or ensiled corn. Recovery of starch after milling was appreciably higher with ensiled corn. Protein recovery in gluten decreased, but this was partially counterbalanced by increased protein content of the steepwater from ensiled corn. Results using batchwise steeping or a simulated countercurrent procedure were similar, though the latter gave higher starch ...


Reovirus Removal And Inactivation By Slow Rate Sand Filtration, L. K. Mcconnell, Ronald C. Sims, B. B. Barnett Jan 1984

Reovirus Removal And Inactivation By Slow Rate Sand Filtration, L. K. Mcconnell, Ronald C. Sims, B. B. Barnett

Ronald Sims

No abstract provided.


Fuel Ethanol From Raw Corn, Curtis Weller, M. P. Steinberg, E. D. Rodda Jan 1984

Fuel Ethanol From Raw Corn, Curtis Weller, M. P. Steinberg, E. D. Rodda

Biological Systems Engineering: Papers and Publications

Crude amylase preparations were produced by growing Aspergillus awamori and A. niger on raw, ground, whole corn. These Koji preparations were used to hydrolyze the starch of raw, ground whole corn to sugars during simultaneous fermentation of the sugars to ethanol by distillers active dry yeast. Ethanol concentrations of the fermentation beers were determined with gas-chromatography. These fermentations yielded an average of 89.6% theoretical ethanol compared to control, conventional, fermentations that had an average of 89.9%. Carbon dioxide evolutions were determined with use of Alwood valves. The initial fermentation rate was greater for the conventional fermentation than the ...


Tillage Influences On Erosion During Furrow Irrigation, Elbert C. Dickey, Dean E. Eisenhauer, Paul J. Jasa Jan 1984

Tillage Influences On Erosion During Furrow Irrigation, Elbert C. Dickey, Dean E. Eisenhauer, Paul J. Jasa

Biological Systems Engineering: Papers and Publications

Erosion and runoff from furrow irrigation of corn was measured for three conventional and three reduced tillage systems in 1981 and 1982. The plots were located on a Hastings silt loam soil having a 0.5% slope and a 366 m furrow length. Erosion was the least for slot-planting and greatest for the chisel system, ranging from 20 to 340 kg/ha, respectively, for the first 45 min of runoff during the first irrigation. Erosion from the fourth irrigation was about 75% less than from the first irrigation. Cumulative runoff after 45 min of runoff was similar for all treatments ...


Tillage, Residue And Erosion On Moderately Sloping Soils, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Thomas Peterson Jan 1984

Tillage, Residue And Erosion On Moderately Sloping Soils, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Thomas Peterson

Biological Systems Engineering: Papers and Publications

Tillage treatments leaving 20% or more of the soil surface covered with residue reduced soil erosion by at least 50% of that which occurred from a moldboard plow system. No-till had the least erosion and tended to have the lowest cumulative runoff. These results were based on rainfall simulation tests on six tillage treatments used on both 5 and 10% slopes in continuous corn production.


Human Health Effects Assays, Ronald C. Sims, J. L. Sims, R. R. Dupont Jan 1984

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

Biological Engineering Faculty Publications

Current development and use of short-term bioassays to evaluate potential human health hazards of environmental chemical exposure has been the focus of the U. S. Environmental Protection Agency (EPA) Second and Third Symposia on the Ap plication of Short-Term Bioassays in the Analysis of Complex Environmental Mixtures.1'2 Topics addressed included development and applications of bioassays, collection and preparation of environmental samples, characterization of hazardous components using bioassays, and environmental assessment. Bartsch and Tomabis,3 using six mutagenicity assays including sub mammalian and mammalian assays to evaluate the quantitative relationship between carcinogenicity and mutagenicity for 532 chemicals, concluded that ...


The Application And Effectiveness Of Slow Sand Filtration In The United States, L. A. Slezak, Ronald C. Sims Jan 1984

The Application And Effectiveness Of Slow Sand Filtration In The United States, L. A. Slezak, Ronald C. Sims

Biological Engineering Faculty Publications

A survey of 27 slow sand filtration plants in the United States indicated that most of these plants are currently serving communities of fewer than 10 000 persons, are more than 50 years old, and are effective and inexpensive to operate. A slow sand filtration research facility in Logan, Utah, was compared with the operating plants to determine if locally available, unsieved sand achieved similar results. The 75‐m3/d research facility performed well in removing turbidity, coliform bacteria, and particles of a size representative of Giardia cysts.