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Articles 1 - 16 of 16

Full-Text Articles in Biomedical Engineering and Bioengineering

The Use Of Dynamic Control In Periodic Counter Current Chromatography, Hans Blom, Helena Skoglar Nov 1985

The Use Of Dynamic Control In Periodic Counter Current Chromatography, Hans Blom, Helena Skoglar

Integrated Continuous Biomanufacturing II

The interest for use of continuous processing in biotech downstream operations is rapidly growing, driven by the gains in productivity, product stability and reduced cost of goods. Continuous processing encompasses a range of different approaches and can relate to both single step operations as well as semi- to fully continuous processes. Improvements in equipment and hardware have now made several commercial systems for continuous chromatography available. As implementation of various strategies for continuous processing becomes more common, the demand/need for reliability in monitoring with existing hardware solutions is steadily increasing. Integration of process analytical technologies will be the determining ...


Application Of Cross-Linked Carboxymethyl Cellulose Degradation By 1-Glucosidase And Vaginal Microbes To Toxic Shock Syndrome, Michael R. Sierks, Peter J. Reilly Sep 1985

Application Of Cross-Linked Carboxymethyl Cellulose Degradation By 1-Glucosidase And Vaginal Microbes To Toxic Shock Syndrome, Michael R. Sierks, Peter J. Reilly

Chemical and Biological Engineering Publications

Eleven bacterial and two yeast strains, four of which were previously identified as having activity on a lightly cross-linked carboxymethyl cellulose (CLD-2) found in one type of superabsorbent tampon, were grown on a variety of substrates, most containing cellulosics. None produced detectable amounts of cellulases, but all elaborated beta-glucosidase. None of these 13 strains nor 3 commercially obtained beta-glucosidase preparations could hydrolyze CLD-2, although a commercial cellulase and two other bacterial preparations known to produce cellulases could. Based on these results, it appears that previous work suggesting that the degradation of CLD-2 by vaginal microbes and beta-glucosidase is implicated in ...


Hydraulics Of Perforated Irrigation Trail Tube, John E. Gilley, Jan Feyen Jun 1985

Hydraulics Of Perforated Irrigation Trail Tube, John E. Gilley, Jan Feyen

Biological Systems Engineering: Papers and Publications

The author presented a methodology for calculating the hydraulics of trail tubes for center-pivot irrigation systems. While he mentioned several possible difficulties with trail tube irrigation, and stated that they have potential benefits in energy saving and improvements in water-use efficiency, additional clarification and analysis are required before the procedures he presented can be used for the rational design of such systems.
First and most importantly, a potential error in the analysis should be mentioned and discussed. The author used the two-term infiltration model of Philip to describe the water intake beneath a center-pivot irrigation system. The assumption of one-dimensional ...


Automated Eeg Spectrum Analysis System, Marinela C. Laguna May 1985

Automated Eeg Spectrum Analysis System, Marinela C. Laguna

Theses

A computer system has been designed to acquire EEG data from monkeys and to perform the spectral and statistical analysis. The system is capable of processing two channels simultaneously, acquire 64 Kbytes of EEG data for each channel on floppy disk, do the spectrums and averages of the spectrums, and calculate the histogram amplitudes of 13 frequency bands in a range of 0-71.1 Hz.

The software gives the user a lot of choices with respect to data acquisition and processing. The relative spectral power differences between "no-drug" and "drug" experiments give information about the drug effects on the central ...


An Inspiration-Triggered Delivery System For Oxygen Therapy Via A Nasal Cannula, Philip Charles Krause, Charles F. Babbs Jan 1985

An Inspiration-Triggered Delivery System For Oxygen Therapy Via A Nasal Cannula, Philip Charles Krause, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Therapy for severe chronic lung disease currently includes the administration of supplemental oxygen to prevent breathlessness and tissue hypoxia. Although effective, this therapy is unnecessarily costly, because oxygen is administered to the patient during expiration as well as inspiration. To eliminate this inefficiency, a delivery system that senses the inspiratory effort and delivers oxygen to the patient only during inspiration was developed. The 11  5  8-cm flow control unit attaches easily to a portable oxygen supply. The components of the system have an expected life of five years, and the 9-Volt battery provides power for about one month of use ...


Use Of Combined Systemic Hypothermia And Local Heat Treatment To Enhance Temperature Differences Between Tumor And Normal Tissues, Charles F. Babbs, William D. Voorhees Iii, Robert R. Clark, David P. Dewitt Jan 1985

Use Of Combined Systemic Hypothermia And Local Heat Treatment To Enhance Temperature Differences Between Tumor And Normal Tissues, Charles F. Babbs, William D. Voorhees Iii, Robert R. Clark, David P. Dewitt

Weldon School of Biomedical Engineering Faculty Publications

The feasibility of combining local heat treatment with wholebody hypothermia in an effort to improve therapeutic gain was assessed. Superficial, non perfused phantom tumors were fashioned in eight anesthetized mongrel dogs by transplantation of the spleen from the abdomen to a subcutaneous site on the hind limb. After pretreatment of the animal with the vasodilator hydralazine (0.5 mg/kg, IV) to enhance normal tissue perfusion, the spleen implant was heated with a 2450-MHz microwave diathermy apparatus, first with the animal's core body temperature in the normal range (39°C) and then after the animal had been packed in ...


Endotracheal Versus Intravenous Epinephrine During Electromechanical Dissociation With Cpr In Dogs, Sandra H. Ralston, Willis A. Tacker, Lee Showen, Alice B. Carter, Charles F. Babbs Jan 1985

Endotracheal Versus Intravenous Epinephrine During Electromechanical Dissociation With Cpr In Dogs, Sandra H. Ralston, Willis A. Tacker, Lee Showen, Alice B. Carter, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The dose-response curves of epinephrine given either IV or endotracheally (ET) were compared during resuscitation from electromechanical dissociation (EMD). Ten anesthetized dogs were subjected to a two-minute period of electrically induced ventricular fibrillation (VF) followed by defibrillation without CPR to produce EMD. Mechanical CPR was followed by injection of either ET or IV epinephrine. Successful response was defined as a return of pulsatile blood pressure within two minutes of drug administration. Using log-dose increments of epinephrine, experimental trials were repeated in each animal. The IV and ET median effective doses were 14 and 130 g/kg, respectively. When the trials ...


Gastric Insufflation During Iac-Cpr And Standard Cpr In A Canine Model, Charles F. Babbs, William E. Schoenlein, Marc W. Lowe Jan 1985

Gastric Insufflation During Iac-Cpr And Standard Cpr In A Canine Model, Charles F. Babbs, William E. Schoenlein, Marc W. Lowe

Weldon School of Biomedical Engineering Faculty Publications

This study was undertaken to determine the effect of interposed abdominal compressions (IAC) during cardiopulmonary resuscitation (CPR) on gastric insufflation when the airway is not secured with an endotracheal tube. A canine model was used in which a common ventilation pressure was applied to separate cuffed esophageal and tracheal tubes. Gas entering the stomach was collected by a pre-placed gastrostomy tube leading to a bell spirometer. Gas entering the lungs was measured with a Wright Respirometer® in series with the endotracheal tube. During standard CPR, measurable gastric gas volume was collected in 28 of 30 trials (mean 215  93 ml ...


Electroventilation, L A. Geddes, William D. Voorhees, Charles F. Babbs, J A. Deford Jan 1985

Electroventilation, L A. Geddes, William D. Voorhees, Charles F. Babbs, J A. Deford

Weldon School of Biomedical Engineering Faculty Publications

Electroventilation is a term used to describe the production of inspiration by applying rhythmic bursts of short duration stimuli to extrathoracic electrodes to stimulate motor nerves to the inspiratory muscles. In the dog, the optimum site for the electrodes was found to be on the upper chest wall, bilaterally. The inspired volume increased with increasing current intensity. The maximum tidal volume attainable was about four times resting tidal volume. The ability of electroventilation to maintain arterial blood oxygen saturation without the production of cardiac arrhythmias was demonstrated in pentobarbital-anesthetized dogs. The technique has several potential applications and offers promise in ...


Writing A Scientific Paper Prior To The Research, Charles F. Babbs, Martha M. Tacker Jan 1985

Writing A Scientific Paper Prior To The Research, Charles F. Babbs, Martha M. Tacker

Weldon School of Biomedical Engineering Faculty Publications

The traditional approach to preparing a research report for publication is to begin writing after the study has been completed. We propose another approach- to write a "zeroth" draft before the study is begun. This approach helps to focus the investigator's attention during the planning stage on critical aspects of the study. The discipline of writing down the rationale, the methods, and the variety of possible outcomes and their significance helps to clarify the logic on which the study is based. If these are acceptable to all authors and colleagues in the zeroth draft, it is likely that the ...


Joseph S. Redding's Contributions To Cardiac Resuscitation, Sandra H. Ralston, Charles F. Babbs Jan 1985

Joseph S. Redding's Contributions To Cardiac Resuscitation, Sandra H. Ralston, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The experimental studies conducted by the late Joseph S. Redding over the past three decades with his students and colleagues form the scientific basis for many aspects of present cardiopulmonary resuscitation (CPR). Redding's research was characterized by its elegance, simplicity, common-sense reasoning, and clinical relevance. Much of his work conducted in the 1960's anticipated with uncanny accuracy some of the most actively discussed issues in resuscitation today (Table 1). Most interesting are Redding's classic studies related to diastolic arterial pressure and myocardial perfusion during CPR, abdominal binding, acid-base status, and use of methoxamine versus other adrenergic drugs ...


Estimating Crop Residue- Using Residue To Help Control Wind And Water Erosion, Elbert C. Dickey, John Havlin Jan 1985

Estimating Crop Residue- Using Residue To Help Control Wind And Water Erosion, Elbert C. Dickey, John Havlin

Biological Systems Engineering: Papers and Publications

The Importance of Conservation Tillage

Conservation tillage has been practiced for many years and is becoming increasingly popular with Nebraska farmers. Recent surveys show, about 8 of 19 million cropland acres in Nebraska were farmed with conservation tillage systems. Conservation tillage includes a variety of tillage and planting systems that leave at least 30 percent of the previous crop's residue on the soil surface after planting.

Knowing how to measure or estimate residue cover is an important facet of conservation tillage. A minimum requirement of cover on the soil surface is often specified for U.S. Department of Agriculture ...


Soil Compaction I Where, How Bad, A Problem, Elbert C. Dickey, Thomas Peterson, Dean E. Eisenhauer, Paul J. Jasa Jan 1985

Soil Compaction I Where, How Bad, A Problem, Elbert C. Dickey, Thomas Peterson, Dean E. Eisenhauer, Paul J. Jasa

Biological Systems Engineering: Papers and Publications

Soil compaction is a more common problem now than it was 15 years ago, regardless of the tillage system used. Producers now use heavier tractors, larger implements, bigger combines, earlier spring tillage, reduced tillage, and no-till planting systems.

While all of these have a potential to increase compaction, the major cause of the problem is conducting field operations when the soil is too wet. Most think about tilling wet soils in the spring as being the major problem, but harvesting a too-wet field in the fall can cause just as much compaction. Large combines and auger wagons can have loads ...


Soil Erosion From Tillage Systems Used In Soybean And Corn Residues, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Thomas Peterson Jan 1985

Soil Erosion From Tillage Systems Used In Soybean And Corn Residues, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Thomas Peterson

Biological Systems Engineering: Papers and Publications

Rainfall simulation techniques were used to compare soil losses from various tillage systems used on plots where corn and soybeans had been grown the previous season. The two year study was conducted on a silty clay loam soil with a 5% slope and on a silt loam soil with a 10% slope. Five tillage treatments, ranging from a moldboard plow system to no-till, were evaluated for each residue at each site. Tillage and planting operations were conducted up-and-down hill on replicated plots. Total soil loss following 63.5 mm of rainfall applied during a 60 min period averaged more than ...


Interril Soil Erosion, Part I. Development Of Model Equations, John E. Gilley, D. A. Woolheiser, D, B. Mcwhorter Jan 1985

Interril Soil Erosion, Part I. Development Of Model Equations, John E. Gilley, D. A. Woolheiser, D, B. Mcwhorter

Biological Systems Engineering: Papers and Publications

Equations describing overland flow depth, rainfall induced soil detachment and sediment transport capacity on interrill areas were identified. The Darcy-Weisbach equation which included a parameter for predicting flow resistance caused by rainfall was used to calculate depth of overland flow. Soil detachment was determined from an equation incorporating raindrop induced, impact pressure estimates. The product of a soil transport factor, bottom shear stress and flow velocity was used to calculate sediment transport capacity. Nondimensional forms of the model equations were evaluated using existing experimental data.


Interril Soil Erosion, Part Ii. Testing And Use Of Model Equations, John E. Gilley, D. A. Woolhiser, D. B. Mcwhorter Jan 1985

Interril Soil Erosion, Part Ii. Testing And Use Of Model Equations, John E. Gilley, D. A. Woolhiser, D. B. Mcwhorter

Biological Systems Engineering: Papers and Publications

Laboratory measurements were made of interrill erosion as affected by varying overland flow discharge and slope slope steepness. Soil detachment and sediment transport capacity relations were then evaluated using experimentally obtained information.

The model equations were utilized to further characterize interrill soil erosion. The overland flow region over which the model equations are applicable for a disturbed Nunn clay loam soil was determined from laboratory tests and critical shear stress analyses. The influence of slope length on interrill erosion was also examined.