Engineering Commons^™

A Labview Program To Obtain The Initiating Component Of A Vergence Eye Movement In An Open-Loop Experiment, Anuj P. Daftari

Theses

The vergence oculomotor system is used in viewing objects moving in depth, such as when a baseball player tracks a ball moving towards him. It is composed of two components according to the Dual Mode Theory; a fast preprogrammed initiating component and a slow feedback-controlled sustaining component. The initiating component is described with open-loop control and the sustaining component is described as a closed-loop feedback control system. Previously, several languages have been utilized to develop programs to study and isolate the open-loop portion of vergence eye movements. Presenting a subject with a stimulus, which initiates an open-loop response has been …

Development Of Fmri Compatible Lower Body Negative Pressure System, Pratap Singh Kunwar

Theses

The lower body negative pressure (LBNP) system provides a controlled, measured orthostatic stress to the cardiovascular system, which can be used with a magnetic resonance imaging (MRI) machine to study cardiovascular and cerebrovascular responses to graded LBNP. In the past, even though functional MRI (fMRI) was considered as one of the best modalities with which to measure small metabolic changes in the brain, it has not been used with an LBNP system to measure cerebrovascular changes. This was due to the lack of an fMRI compatible LBNP system.

In this project, an tMRI compatible LBNP system was first constructed without …

Transmission Of Light And Audible Sound In A Synthetic Fog Medium, Bhavin Babaria

Theses

The primary goal of the thesis was to study the propagation of visible light and auditory sound through a synthetic fog medium compared to an ambient air environment. It is known that the fog substantially decreases the visibility however; this has not been studied quantitatively. Further information regarding other energies such as sound is also needed to understand how the energy reacts in the fog medium. The extent of visual and auditory degradation in humans needs to be investigated. Researchers have studied light transmitted through water, air; however, no one has studied how light or sound is transmitted through a …

Evaluation Of Postural Stability Using Sensory Organization Test, Tiffany Sims

Theses

Poor postural stability of the elderly and other patients has been a major concern.The cost of treating injuries due to poor stability is expected to rise to $32.4 Billion by 2020. Many interventions have been proposed and used to improve stability. In order to determine the efficacy of these interventions, an objective evaluation of postural stability before and after intervention is important.

The aim of this thesis was to scientifically analyze the ambiguities in the equilibrium score (ES) given by the Neurocom Smart Equitest (NSE) machine, and compare it to a new measure of stability that has been proposed by …

Mechano-Biological Interactions Of Endothelial Cells, Claire Brougham, Karen Coughlan, Valerie Barron, Peter Mchugh

Conference Papers

Atherosclerosis is an ever-increasing cause of morbidity in the western world. Current surgical treatments include bypass grafts and coronary artery stents. However, there is still a need for alternative approaches especially for those who cannot receive conventional therapy. Tissue engineering is one such approach that may hold the key to the repair and regeneration. Tissue engineering is one such approach that may hold the key to the repair and regeneration of coronary arteries. Nevertheless, many questions need to be answered before a vialbe vascular tissie with the inherent properties of native tissue becomes a real contender with the surgical therapies …

Total Reduced Sulfur Concentrations In The Vicinity Of Beef Cattle Feedlots, Richard K. Koelsch, Bryan L. Woodbury, David E. Stenberg, Daniel N. Miller, Dennis D. Schulte

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A field survey of total reduced sulfur (TRS) concentrations in the vicinity of beef cattle feedlots was conducted to compare field observations against current regulatory thresholds. In addition, environmental factors that may contribute to increased TRS emissions were evaluated. It was observed that TRS levels in the vicinity of beef cattle feedlots are not likely to exceed current regulatory thresholds used by midwestern states. It was further noted that concentration of TRS varies with air temperature and time of day. However, wet feedlot surface conditions and wind speed had almost no impact upon observed concentrations.

Bie6810 - Biochemical Engineering, Spring 2004, Ron Sims

Biological and Irrigation Engineering - OCW

Biochemical processes, thermodynamics, and kinetics are used in the application of engineering principles to analyze, design, and develop processes using biocatalysts. Processes covered in the course include those that are involved in the formation of desirable compounds and products or in the transformation, or destruction of unwanted or toxic substances.

Bie6300 - Irrigation & Conveyance Control Systems, Spring 2004, Gary P. Merkley

Biological and Irrigation Engineering - OCW

This is a course regarding measurement of flow rates and water levels. Calibration, design, and selection of open-channel flow measurement structures. Design of irrigation conveyance and distribution system infrastructure.

Bie6150 - Surface Irrigation Design, Spring 2004, Wynn Walker

Biological and Irrigation Engineering - OCW

This course was originally developed for the United States Department of Agriculture. It contains nearly 20 video lecture presentations with accompanying slides in English, Arabic, and French, an online textbook, homework assignments, and downloadable surface irrigation simulation software also developed by Dr. Walker. This course highlights design and evaluation of surface irrigation systems, field measurements for evaluating and improving uniformity and efficiency, simulation of surface systems, and land leveling computation and equipment. Note: The simulation software is designed to run on a PC only.

Overview Of Metal-On-Polyethylene, Metal-On-Metal, And Ceramic Hip Wear Mechanisms, A. Buford, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Premature failure of orthopaedic hip implants caused by multiple wear mechanisms is the primary failure mode of prosthetic hips. Wearing of the implants may lead to aseptic loosening, biological incompatibilities, and mechanical failure of the implant. In order to prevent or restrict the effects of the wear mechanisms, multiple laboratory studies are being conducted in order to determine each mechanism and its contribution to increased wear rates. This paper combines previous laboratory studies related to the wear of metal-onpolyethylene, metal-on-metal, and ceramic materials. The bulk quantity materials discussed include cobalt chromium alloys, stainless steels, zirconium oxide ceramics, and polyethylene materials …

Policosanol Contents And Composition Of Grain Sorghum Kernels And Dried Distillers Grains, Keum T. Hwang, Curtis L. Weller, Susan L. Cuppett, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain sorghum can be a major source of policosanols, long-chained alcohols, that have beneficial physiological activities. Sorghum dried distillers grains (DDG), a by-product of ethanol production from grain sorghum. contain a large amount of policosanols. Content and composition of policosanols in long-chained lipids extracted from grain sorghum kernels and DDG were determined. Long-chained lipids were extracted using hot hexane or hot ethanol. The major components of the long-chained lipids extracted from grain sorghum kernels. as determined using HPLC were policosanols (37-44%), aldehydes (44-55%), and acids (4-5%). Long-chained lipids from DDG contained 52% policosanols, 23% aldehydes. 6.4% acids. and l7% wax …

Improving Heating Uniformity Of Fresh Fruit In Radio Frequency Treatments For Pest Control, Sohan Birla, Shaojin Wang, Juming Tang, Guy Hallman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Non-uniform heating of fresh fruit caused by variations in radio frequency (RF) fields is a major obstacle in developing postharvest insect control treatments based on RF energy. A fruit mover was developed to evaluate possibilities to improve RF heating uniformity of large fruit, such as oranges and apples, in a 12 kW batch type RF system. This fruit mover provided a means to rotate and move fruit in water when subjected to RF heating. Parameters for moving and rotating fruit in the mover were selected based on consideration of vortex formation, foaming, damage to the fruit, and volume occupied by …

Wear Mechanisms In Ceramic Hip Implants, M. Slonaker

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The wear in hip implants is one of the main causes for premature hip replacements. The wear affects the potential life of the prosthesis and subsequent removals of in-vivo implants. Therefore, the objective of this article is to review various joints that show lower wear rates and consequently higher life. Ceramics are used in hip implants and have been found to produce lower wear rates. This article discusses the advantages and disadvantages of ceramics compared to other implant materials. Different types of ceramics that are being used are reviewed in terms of the wear characteristics, debris released, and their size …

Wear Mechanisms In Ceramic Hip Implants, M. Slonaker, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The wear in hip implants is one of the main causes for premature hip replacements. The wear affects the potential life of the prosthesis and subsequent removals of in-vivo implants. Therefore, the objective of this article is to review various joints that show lower wear rates and consequently higher life. Ceramics are used in hip implants and have been found to produce lower wear rates. This article discusses the advantages and disadvantages of ceramics compared to other implant materials. Different types of ceramics that are being used are reviewed in terms of the wear characteristics, debris released, and their size …

General Creep-Fatigue Life Prediction Models, J. Toland, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

This paper presents a data bank that was compiled from published and unpublished sources. Using these data, low cycle fatigue curves were generated under a range of test conditions showing the effect of test parameters on the Coffin-Manson behavior of steel alloys. Generic equations have been developed in this paper to predict the creep-fatigue life of high temperature materials. Several new multivariate equations were developed to predict the creep-fatigue life of following alloy groups; I) Cr-Mo steels, 2) stainless steels and 3) generic materials involving the materials from the following alloy groups, solder, copper, steels, titanium, tantalum, and nickel based …

Leaching And Sorption Of Nitrogen And Phosphorus By Crop Residue, J. D. Cermak, John E. Gilley, Bahman Eghball, B. J. Weinhold

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Overland flow from cropland areas often contains nutrients and residue materials can either contribute to runoff nutrient load through leaching or remove nutrients by sorption. Measurements were made of leaching and sorption of nitrogen and phosphorus from corn (Zea mays L.), soybean (Glycine max (L.) Merr.) and winter wheat (Triticum aestivum L. cv. Pastiche) residues placed in solutions containing inorganic nutrients. Variables used were type of residue material, nutrient constituent, solution concentration, and residue / solution contact time. For a given residue material and nutrient constituent, four different solution concentrations were used (PO₄ -P: 0 to …

Long Stemmed Total Knee Arthroplasty With Interlocking Screws: A Computational Bone Adaptation Study, Jeffry S. Nyman, Scott J. Hazelwood, Juan J. Rodrigo, R. Bruce Martin, Oscar C. Yeh

Biomedical Engineering

The ability of an interlocking screw fixation technique to minimize bone loss related to stress shielding in the tibia was investigated and compared to the abilities of cement and press-fit fixation. Full bony ingrowth has been associated with greater stress shielding than partial ingrowth; therefore, the effect of intimate bonding of the stem to bone on subsequent bone loss was also studied. A damage-and disuse-based remodeling theory was coupled with a two-dimensional finite element model of the tibia to predict changes in bone remodeling following long stemmed total knee arthroplasty (TKA) for four different fixation techniques (cement, press-fit, interlock with …

Electrospinning As A Processing Method For Electroactive Polymers And Composites, Kristin Joy Pawlowski

Theses and Dissertations

Electrospinning was examined for its potential to create functional materials. Three distinct electroactive materials were electrospun into fibers and fiber mats and then characterized with the intent of determining their utility in aerospace and biomedical applications such as micro-air vehicles and the cardiovascular system. Electrospun Graft Elastomers demonstrated potential as actuators, as electromechanical strain testing showed comparable response to the film form of this material. Further improvement of electroactive response was realized with high dielectric inclusions and fiber orientation. Electrospin processing imparted piezoelectric properties to the fibers of poly(vinylidene fluoride). Differential scanning calorimetry and infrared spectroscopy indicated a degree of …

Loss Of Sympathetic Control Of Cardiovascular Function Following Spinal Cord Injury, Charles Everett Hogancamp Ii

University of Kentucky Master's Theses

Cardiovascular control in the human is significantly impaired after spinal cord injury(SCI) having a direct effect on the sympathetic nervous system (SNS) causing an inability toregulate vasoconstriction below the level of the lesion. The effects of SCI on the two majorcomponents of blood pressure regulation, control of plasma volume and neural control of theheart and peripheral vasculature are poorly understood. In particular, no index to diagnosedisorders to autonomic control of the heart and vasculature has been developed. The presentstudy primarily utilized noninvasively acquired, easily accessible variables that may havepromise as indicators of autonomic activity for assessing the level of autonomic …

Microscale Investigation Of Thermo-Fluid Transport In The Transition Fil, Region Of An Evaporating Capillary Meniscus Using A Microgravity Environment, Kenneth D. Kihm, Jeffrey S. Allen, Kevin P. Hallinan, David M. Pratt

Mechanical and Aerospace Engineering Faculty Publications

In order to enhance the fundamental understanding of thin film evaporation and thereby improve the critical design concept for two-phase heat transfer devices, microscale heat and mass transport is to be investigated for the transition film region using state-of-the-art optical diagnostic techniques. By utilizing a microgravity environment, the length scales of the transition film region can be extended sufficiently, from submicron to micron, to probe and measure the microscale transport fields which are affected by intermolecular forces. Extension of the thin film dimensions under microgravity will be achieved by using a conical evaporator made of a thin silicon substrate under …

Stimulation Of Capacitative Calcium Entry In Hl-60 Cells By Nanosecond Pulsed Electric Fields, Jody A. White, Peter F. Blackmore, Karl H. Schoenbach, Stephen J. Beebe

Bioelectrics Publications

Nanosecond pulsed electric fields (nsPEFs) are hypothesized to affect intracellular structures in living cells providing a new means to modulate cell signal transduction mechanisms. The effects of nsPEFs on the release of internal calcium and activation of calcium influx in HL-60 cells were investigated by using real time fluorescent microscopy with Fluo-3 and fluorometry with Fura-2. nsPEFs induced an increase in intracellular calcium levels that was seen in all cells. With pulses of 60 ns duration and electric fields between 4 and 15 kV/cm, intracellular calcium increased 200-700 nM, respectively, above basal levels (similar to100 nM), while the uptake of …

Studies In Cardiac Defribrillation, Eamonn Mckenna

Masters

Cardiac disease resulting in cardiac arrest is one of the most common fatal diseases in the developed world. Defibrillation is the medical procedure used to correct the irregular cardiac rhythm (ventricular fibrillation (VF)) which is very often detected in patients suffering cardiac arrest. In the work reported in this thesis, two aspects of the defibrillation of patients in VF were examined. The first area of investigation concentrated on the use of multiple defibrillation electrodes to be used during closed chest (transthoracic) defibrillation. This study was carried out in a saline bath and centred on “focusing” electric fields from perimeter electrodes …

Meta-Analysis Of Two-Treatment Clinical Trials Including Both Continuous And Dichotomous Results, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

To expedite the timely creation of medical practice guidelines, a meta-analytic method was developed to combine of both dichotomous survival data and continuous physiologic data from multiple studies comparing the same innovative clinical intervention to standard care. The method is adapted for synthesis of small, early studies of novel treatments. An aggregate ratio, R*, of the observed treatment effect to a clinically optimal treatment effect for studies in a series is computed, and compared to the 95% confidence limit for R* under the null hypothesis. Weights assigned to each study may reflect its precision, quality, or clinical relevance. Input data …

Optimizing Chest Compression To Rescue Ventilation Ratios During One-Rescuer Cpr By Professionals And Lay Persons: Children Are Not Just Little Adults, Charles F. Babbs, Vinay Nadkarni

Weldon School of Biomedical Engineering Faculty Publications

Objective: To estimate the optimum ratio of chest compressions to ventilations for onerescuer CPR that maximizes systemic oxygen delivery in children. Method: Equations describing oxygen delivery and blood flow during CPR as functions of the number of compressions and the number of ventilations delivered over time were adapted from the former work of Babbs and Kern. These equations were solved explicitly as a function of body weight, using scaling algorithms based upon principles of developmental anatomy and physiology. Results: The optimal compression to ventilation (C/V) ratios for infants and younger children increase sharply as a function of body weight. Optimal …

Residual Effects Of Manure And Compost Applications On Corn Production And Soil Properties, Bahman Eghball, Daniel Ginting, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Residual effects of manure or compost application on crop production and soil properties can last for several years. This study was conducted to evaluate residual effects of annual or biennial applications of N- and P-based composted and non-composted beef cattle (Bos Taurus) feedlot manure, chemical fertilizer, and no-treatment check on corn (Zea mays L.) production and soil properties. Manure and compost were applied from 1992 to 1995, and the residual effects were determined from 1997 to 1999. Residual effects of N- and P-based manure and compost applications on corn grain yield and N uptake lasted for at …

Changes In Composition And Thermal Transition Temperatures Of Grain Sorghum Wax During Storage, Keum Taek Hwang, Curtis L. Weller, Susan L. Cuppett, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Grain sorghum (Sorghum bicolor) wax is composed mainly of aldehydes, alcohols, and acids. Aldehydes, comprising about one-half of the wax, are readily converted to acids in presence of air. In this study, whole sorghum wax and an aldehyde fraction from sorghum wax were subjected to oxidative conditions. Changes in the major components and thermal transition temperatures were determined using HPLC and differential scanning calorimeter (DSC), respectively. The aldehyde fraction was oxidized markedly to acids over 4 months in storage at room temperature. Acid content, in the fraction, was initially 5–7% and increased to 42–51% after 135 days in …

Controlled Release Systems For Dna Delivery, Angela K. Pannier, Lonnie D Shea

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Adapting controlled release technologies to the delivery of DNA has the potential to overcome extracellular barriers that limit gene therapy. Controlled release systems can enhance gene delivery and increase the extent and duration of transgene expression relative to more traditional delivery methods (e.g., injection). These systems typically deliver vectors locally, which can avoid distribution to distant tissues, decrease toxicity to nontarget cells, and reduce the immune response to the vector. Delivery vehicles for controlled release are fabricated from natural and synthetic polymers, which function either by releasing the vector into the local tissue environment or by maintaining the vector at …

Development Of An Instrumented Deep−Tillage Implement For Sensing Of Soil Mechanical Resistance, Viacheslav I. Adamchuk, Andrey V. Skotnikov, Justin D. Speichinger, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Variable−depth tillage has the potential for economic and environmental benefits to modern crop production. Varying tillage depth according to local soil conditions prevents the waste of energy and preserves soil ecology. A prototype instrumentation system was developed based on a conventional implement for deep tillage. It was equipped with two load cells and two sets of strain gauges for sensing the load applied to the implement during tillage. Two linear pressure distribution models (full and redundant) were used to describe the change of soil mechanical resistance with depth. These models were then used to compare estimates of soil mechanical resistance …

Predicting Tractor Fuel Consumption, Robert D. Grisso, Michael F. Kocher, David H. Vaughan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Reports from the Nebraska Tractor Test Laboratory (NTTL) show improved fuel efficiency during the past 20 years. A 4.8% decrease in average annual specific volumetric fuel consumption for the data used in the ASAE Standards was shown. Using fuel consumption and power data from the NTTL reports, new equations for fuel consumption were established that predict fuel consumption for diesel engines during full and partial loads and under conditions when engine speeds are reduced from full throttle.

Field Efficiency Determination Using Traffic Pattern Indices, Robert D. Grisso, Michael F. Kocher, Viacheslav I. Adamchuk, Paul J. Jasa, Mark A. Schroeder

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Field efficiency is an important criterion for determining field capacity during field operations and, indirectly, for making important machinery management decisions. Geographic location data gathered with a yield monitor during harvest and a data logger during planting were used to provide time−motion studies of equipment and operator productivity. This study used these spatial and temporal data to quantify field performance of a combine and a planter. Seven Nebraska fields were used to compare results from soybean and corn production systems. Fields that were relatively flat with straight rows were contrasted with contoured fields with slopes of 3% to 5%. Two …