Engineering Commons^™

A Multicompartmental Model For The Simulation Of Soluble Gas Exchange In The Lungs, Chitaranjan Varadhan

Theses

No abstract provided.

Analysis Of Cutthroat Flume Discharge Ratings, Liyan Ren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sixteeen sets of original laboratory data collected by many investigators for various Cutthroat flume sizes are thoroughly reviewed and organized. Best-fit discharge parameters are obtained by performing the free-flow analysis and the submerged-flow analysis. Then, the transition submergence can be calculated. Afterwards, the unified free-flow and submerged-flow discharge parameters are developed for each flume size in order to generalize the calibrations for Cutthroat flumes. This is a very tedious process requiring a trial-and-error approach. Finally, comparisons are made of the measured laboratory discharges with the predicted discharges for both free flow and submerged flow using both the best-fit and the …

Competitive Enzyme Immunoassay By Polyclonal Antibodies Against Organophosphorus Pesticides, Kuo-Lan Wen

Theses and Dissertations in Biomedical Sciences

Organophosphorus compounds (OPs) comprise one of the major classes of pesticides in use today because they are highly effective and less toxic. Because of their extensive use, there is a need for monitoring OPs in water and vegetables. Gas chromatography (GC) is the usual method for OPs screening, but it is time-consuming and has the high cost of instrumentation. The goal of this project was to find an easy method which was sensitive and had less instrumentation required to test OPs.

Microwells and microtubes were utilized as the solid-phase immobilization for the development of an enzyme immunoassay for OPs. A …

Simulated Thermal Performance Of A Solar Heated Floor, Michael F. Kocher, James A. Deshazer, Gerald R. Bodman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A low cost, simple solar heating system consisting of an active collector with an In-Floor Heat Distribution and Storage (IFHDS) system was developed in response to the energy crisis of the 1970s. A two-dimensional finite difference model was developed and used to simulate the performance of IFHDS system cross-sections. Simulation runs were conducted with a steady-periodic model for the temperature of the solar-heated air in the IFHDS system cross-section. The steady periodic simulation results indicated IFHDS system energy efficiency increases with decreasing air temperature in the room above the IFHDS system, peak temperature of the solar-heated air in the IFHDS …

Critical Shear Stress And Critical Flow Rates For Initiation Of Rilling, John E. Gilley, W. J. Elliot, J. M. Laflen, J. R. Simanton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study was conducted to identify critical shear stress and critical flow rates required to initiate rilling on selected sites. The data used in this investigation were collected from soils located throughout the USA where crop residues had been removed, and moldboard plowing and disking had occurred. Runoff and soil loss measurements were made on sites where simulated rainfall was applied to preformed rills. Multiple regression analyses were used to relate critical shear stress values and critical flow rates to selected soil properties. The soil-based regression equations were found to provide reliable estimates. Information identified in this study will improve …

Dynamics Of Blood Coagulation, Jie Gao

Theses

In this paper we present a new method to analyze whole blood coagulation dynamics. Using a PC-286 computer equipped with a DASH-16 AID board.

The row data from a SONOCLOT analyzer is amplified and digitized on the DASH-16 A/D board and stored in the PC-286 hard disk. The data is filtered through a digital Butterworth filter. The filtered data is then fit to mathematical relationship by the least square method. The coefficients which define the mathematical relationships are used to identify blood specimens with normal coagulation dynamics as distinguished from specimens with abnormal dynamics.

The digital filter and curve-fitting routine …

A Review Of Energy Storing Prosthetic Feet And Computer Aided Structural Optimization Of A Below-Knee Prosthesis, Poonam Gope Lalwani

Theses

Because people with physical disabilities have shown an interest in participation in sports, a new class of prosthetic feet known as "energy storing prosthetic feet" has been developed. These new developments in prosthetic foot design utilize energy storage and return to improve ambulation. This thesis reviews the design, materials, advantages and disadvantages of various energy storing prosthetic feet. Research studies, comparing gait in below-knee amputees using different prosthetic designs, can be applied to the design of prosthetic feet that are lighter, stronger and more reliable. Comparisions among these feet are reviewed in the context of functional capability and patient satisfaction. …

A Study Of Pulsation Of Chest Wall Using Microwave Interferometer, Paul Zeno

Theses

The microwave interferometer is utilized to pick up vibrations of the anterior chest wall produced by the cardiac activity. The objective of this project is to find the causes of different peaks in the output of the microwave interferometer. The output of the microwave interferometer is recorded simultaneously with EKG and jugular pressure pulses. Eighteen subjects had their mechanical vibrations of the chest wall, EKG and jugular pressure pulses recorded. The processed interferometer data, when compared with EKG and jugular pressure pulses appear to have a close relation to the mechanical events in the cardiac cycle. Four peaks in the …

The Thermal Model Of The Rat Under Hemorrhagic Shock Hypothermia With Microwave Intervention, Liu Zhe

Theses

A whole body thermal model simulating heat distribution and temperature regulation in rats during hemorrhagic shock and during post-shock microwave core rewarming period was developed. An electrical circuit was used to simulate the thermal system and a software named PSpice? was used to analyze the circuit. The temperature regulation as the result of the simulation is demonstrated to match the measured temperature histories of rats in hemorrhagic shock and the microwave rewarming experiment.

The blood pressure drop and cardiac output decrease were considered in the simulation and the so called "set point temperature" was investigated in the model. Linear decrease …

Computer Aided Finite Element Stress Analysis Of A Three Dimension Mandibular Bone Model Using I-Deas Software, Yixiong Xu

Theses

A three dimensional model of half of the mandibular bone, with 487 tetrahedra elements and 1,047 nodes, is established and analyzed by means of I-DEAS software. The masseter muscle is assumed to be 15° deviation from y-axis, and the Umetani boundary conditions are allowed to be varied. A 337 lb force was applied along the midline of the mandible to simulate a trauma force caused by the auto accident. The maximum principal stress is 18,400 psi and the minimum principal stress is -1,340 psi. Depending on the experimental results of dispalcement and maximum principal stress, the conclusions are drawn: 1) …

Fingerprint Pattern Recognition For Medical Uses, Feng You

Theses

The purpose of my research is to provide a method to automatically classify fingerprints into three subgroups: whorl, loop and arch, which can help medical scientists to study the relationship between fingerprint patterns and medical disorders. In the research, two different kinds of approaches were developed. The first one is performing pattern recognition in the frequency domain, which uses the feature of Fourier spectrum. That is, prominent peaks in the spectrum give the principal direction of fingerprint patterns. Using the above feature, we can obtain the principal direction of every subregion, after which the pattern of the whole image can …

Heating Of Calcium Phosphate Crystals: Morphological Consequences And Biological Implications, W. Bohne, J. A. Pouezat, L. Peru, G. Daculsi

Cells and Materials

Sintering hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) affects the chemical composition, the crystallinity, and the morphological features as demonstrated by means of X-ray diffraction (XRD) , infrared spectroscopy (IR), and scanning electron microscopy (SEM). When heated to 1230°C, 16.7% of HA had decomposed to ß-TCP. SEM investigations showed homogeneous, sharp angular polyhedric blocks of 30 to 50 µm with rare surface pores. On heating at 1230°C, ß-TCP had entirely transformed to a-TCP. During sintering, the size of the powder grains increased and progressive bridging between the grains was observed. At 1230°C, a network within round-shaped polyhedric blocks of 50 to …

Bone Growth On Sol-Gel Calcium Phosphate Thin Films In Vitro, Q. Qiu, P. Vincent, B. Lowenberg, M. Sayer, J. E. Davies

Cells and Materials

Thin, sub-micron, films of calcium phosphate were fabricated on either glass or quartz supports by a colloidal suspension sol-gel method. These films, which varied in both surface chemistry and topography were then employed as culture substrata for osteogenic rat bone marrow cells. During an 18 day culture period, the cells elaborated a morphologically distinguishable bone matrix on all substrata which was similar to that reported earlier on tissue culture polystyrene. Selected samples of the culture substrata were fractured, critical point dried, and observed by scanning electron microscopy. Particular attention was paid to the morphologies of the interface between the so1-gellayer …

Mineralized Matrix Synthesis By Isolated Mouse Odontoblast-Like Cells In Vitro, P. B. Andrews, A. R. Ten Cate, J. E. Davies

Cells and Materials

First mandibular molar tooth germs were dissected from 17 day mouse embryos. The dental papilla was isolated using both mechanical separation and enzymatic digestion. The cells of the papilla were then enzymatically disaggregated and cultured in 35 mm polystyrene dishes containing alpha minimum essential medium supplemented with 15 % fetal calf serum, 50 μglml ascorbic acid, 1 o-8 M dexamethasone and 10 mM Na-13-glycerophosphate. The cultures were maintained for 23 days. The cultured cells initially appeared as large flat cells having numerous cell processes. Multilayered cell nodules, distributed randomly in the cultures, were apparent after 5 days. Matrix was visible …

Ultrastructural, Cytochemical, And Immunocytochemical Studies On Bone And Its Interfaces, M. D. Mckee, A. Nanci

Cells and Materials

Bone cells possess the ability to synthesize, secrete and direct the assembly and maintenance of extracellular matrix to form a functionally rigid and/or weight-bearing mineralized tissue complex, the skeleton. The skeleton not only supports and protects the organs and tissues of the body, but also acts as a mineral ion reservoir for maintaining systemic calcium balance (calcium homeostasis). The remarkable biological precision necessary for the formation, turnover and constant adaptation of bone to external mechanical forces is a dynamic process requiring a coordinated cellular effort relying on a variety of cell-cell and cell-matrix/mineral interactions. Indeed, cell-matrix interfaces found in a …

Multinucleated Giant Cells-Hydroxyapatite Interactions: A Time-Related Quantitative Study In A Rat Skull Defect, J. M. Dersot, A. Llorens, J. L. Saffar

Cells and Materials

The implantation of calcium phosphate ceramics in the bone environment elicits the differentiation of multinucleated giant cells (MNGCs). MNGC interactions with both crushed and standard hydroxyapatite (HA, Bioapatite ®) particles (cHA and sHA) were studied in rat skull defects. Light microscopy (LM) of undemineralized material after 21 and 42 days of implantation showed that the number of particles in the defect significantly decreased (about SO%) with the two HA forms. Concomitantly, average cHA particle size increased significantly due to the elimination of the smallest particles by the MNGCs. The number of MNGCs per mm2 of defect decreased significantly between 21 …

Evaluation Of Drug Delivery Systems By Electron Microscopy Techniques, Y. V. Pathak, V. D. Labhashetwar

Cells and Materials

This review covers the applications of electron microscopic techniques to the characterization and evaluation of drug delivery systems. Various electron microscopic (EM) related techniques such as transmission electron microscopy, scanning electron microscopy (SEM), SEM with energy dispersive X-ray microanalysis, and freeze-fracture electron microscopy are extensively used for this purpose. Microcapsules, microspheres, nanocapsules, liposomes , polymeric carriers and other drug delivery systems are characterized using EM related techniques for their surface topography, size and shape analysis, biodegradation, in vitro - in vivo evaluation and drug excipient interactions and characterization. Electron microscopy methods are very useful in understanding the mechanism of drug …

Metallurgical Structures Of As-Cast And Heat-Treated High-Palladium Dental Alloys, William A. Brantley, Zhuo Cai, Alan B. Carr, John C. Mitchell

Cells and Materials

Scanning electron microscope observations and energy-dispersive spectroscopic analyses have been performed on two first-generation and two second-generation high-palladium dental casting alloys. A specimen design simulating a maxillary central incisor coping was employed to conserve metal, while providing thin and thick sections to yield a range of solidification rates. The alloys were centrifugally cast in air, following standard dental laboratory techniques; three castings were prepared for each alloy. Each casting was sectioned to produce two mirror-image specimens, and one specimen received the appropriate oxidation heat treatment, followed by a simulated full porcelain firing sequence. After metallographic polishing, specimens were examined with …

A Comparative Study Of The Interactions Of Two Calcium Phosphates, Peo/Pbt Copolymer (Polyactive) And A Silicone Rubber With Bone And Fibrous Tissue, C. A. Van Blitterswijk, J. R. De Wijn, H. Leenders, J. V.D. Brink, S. C. Hesseling, D. Bakker

Cells and Materials

In this study, hydroxyapatite, tetracalcium phosphate, HPEO/PBT 55145 copolymer, PEO/PBT 55!45 copolymer (Polyactive) and silicone rubber were implanted as dense blocks, subcutaneously and. into the tibia of rats. Biocompatibility and degradation were investigated but most attention was directed to .the bone/biomaterial interactions. None of the materials showed any significant adverse tissue reactions. With exception of the silicone rubber, all materials sho~ed bone bonding phenomena based on both morphological and mechanical evaluations. (H)PEO/PBT 55145 copolymer is the first polymer reported to be bonded by bone and thus widens the spectrum of bone bonding materials with a low modulus, degradable, elastomer in …

Immunohistochemical Investigation Of Tracks Left By The Migration Of Fibroblasts On Titanium Surfaces, Y. Abiko, D. M. Brunette

Cells and Materials

Fibronectin, a major attachment protein, has been thought to be involved in pathway guidance, a process in which cells migrate along specific pathways within a tissue during development. Fibroblasts exhibit the phenomenon of contact guidance, the tendency of cells to be guided in their direction of migration by the shape of the substratum. The purpose of our study was to test the hypothesis that fibronectin tracks are deposited by fibroblasts moving on smooth and grooved titanium surfaces.

The study was carried out on human gingival fibroblasts which were plated onto both smooth and grooved titanium substrata using medium containing either …

Experimental Induction Of Odontoblast Differentiation And Stimulation During Preparative Processes, H. Lesot, C. Begue-Kirn, M. D. Kubler, J. M. Meyer, A. J. Smith, N. Cassidy, J. V. Ruch

Cells and Materials

In vivo implantation experiments have shown that ethylenediaminetetraaceticacid(EDTA)-soluble frac tions of dentin stimulate reparative dentinogenesis . When isolated embryonic dental papillae were cultured in the presence of these dentin constituents, odontoblast cytological and functional differentiation could be initiated and maintained in the absence of an enamel organ. These effects were attributed to the presence of TGF-/1- related molecules [TGF-/11 or bone morphogenetic protein -2a (BMP-2a)] which had to be used in combination with an EDT A-soluble fraction of dentin in order to specifically affect competent preodontoblasts . These EDT A-soluble constituents present in dentin could be replaced by heparin or …

Calcification Of Liposomes And Red Cell Ghosts In Vitro And In Vivo, Kookmin M. Kim

Cells and Materials

To study the role of membranous phospholipids in calcification , liposomes made of phosphatidylserine and red blood cell ghosts (RBCG) prepared from rat and canine blood were incubated in minimal essential medium (MEM) with 2 .5 mM (mmol/l) calcium and 1.3 mM phosphate, pH 7.4 (MEM-2.5), and homologous (rat) or autologous (canine) plasma filtrate (serum) at 37°C for up to 1 week. Calcification was determined by electron probe microanalysis , electron diffraction, and depletions of calcium and phosphate from MEM-2.5 and sera. Liposomes and rat-RBCG incubated in MEM-2.5 and serum calcified in a week, whereas isolated collagen and elastin did …

Interaction Of Ciprofloxacin Loaded Liposomes With Pseudomonas Aeruginosa Cells, R. Nicholov, A. E. Khoury, A. W. Bruce, F. Dicosmo

Cells and Materials

An antibiotic delivery system has been developed using ciprotloxacin (CIPRO) encapsulated within sonicated unilamellar vesicles (SUV) of different lipid compositions composed of dipalmitoylphospatidylcholine (DPPC), L-aphosphatidylcholine (PC), phosphatidylethanolamine (PEA) and cholesterol (CHOL). The interaction of SUV (i.e. liposomes) with Pseudomonas aeruginosa (Tl 2977) cells was studied and the effect of the liposome encapsulated antibiotic was tested. Encapsulation of CIPRO apparently increased the amount of antibiotic resident in the vicinity of bacteria in aqueous solution at neutral pH.

Electrophoretic mobility measurements showed that P. aeruginosa cells were negatively charged. The zeta potential of P. aeruginosa was -11.4 ± 2.9 m V in …

Lysine Effect On Ruthenium Red And Alcian Blue Preservation And Staining Of The Staphylococcal Glycocalyx, Theresa A. Fassel, James R. Sanger, Charles E. Edmiston

Cells and Materials

The effect of lysine on ruthenium red (RR) and alcian blue (AB) preservation arid/or staining for transmission electron microscopy of glycocalyces was evaluated for three species of the gram-positive, coagulase-negative staphylococci. A RR and an AB procedure were compared with and without lysine included in the glutaraldehyde prefixation. Minimal or no glycocalyx was preserved or stained by glutaraldehyde fixation only. For all species, the inclusion of lysine increased visualization of fibrous material. RR treatment without lysine, results in sparse or limited fibrous material or artifactual condensations which contrasts with enhanced fibrous material seen when lysine is included with RR. The …

Are Long Term Cryopreservation And Patency Of Vein Allograft Truly Achievable?, G. Pasquinelli, G. L. Faggioli, P. Preda, M. Vici, G. N. Martinelli, R. Giardino, M. D'Addato, J. J. Ricotta

Cells and Materials

Despite extensive experimental work, neither the effect of long term cryopreservation on vein graft architecture nor the failure of alloveins due to graft rejection have yet been investigated. Herein, we investigated ultrastructurally: a) the integrity of rabbit jugular veins following 1, 2 and 3 months of cryopreservation; b) the outcome of the three-month cryopreserved vein auto- and allografts after 1 month of implantation in the rabbit carotid artery; and c) the immunologic response to cryopreserved vein allografts with and without seeded autologous endothelium. Prior to implantation, the cryopreserved rabbit veins were well-maintained except for endothelial cell damage. Following implantation, the …

Influence Of Crystal Structure On The Establishment Of The Bone-Calcium Phosphate Interface In Vitro, J. D. De Bruijn, C. P. A. T. Klein, K. De Groot, C. A. Van Blitterswijk

Cells and Materials

An in vitro rat bone marrow cell system was used to examine the interfacial ultrastructure established between various calcium phosphates and mineralized tissue. The investigated calcium phosphates comprised hydroxyapatite (HA), fluorapatite (FA), tricalcium phosphate (TCP), tetracalcium phosphate (TECP) and magnesium whitlockite (MWL). Both scanning and transmission electron microscopy were used to examine the elaborated interface. The time in which a mineralized extracellular matrix was formed on the various materials differed from 2 weeks on HA, TCP and TECP, to 8 weeks on FA. It was only occasionally observed in some areas on MWL, which might have been due to aluminum …

Degradation Of Polymeric Biomaterials, Shalaby W. Shalaby, Russell A. Johnson, Meng Deng

Cells and Materials

Environmental and processing factors affecting the biostability of medical devices made from traditionally "stable" polymers, such as isotactic polypropylene (PP) and ultrahigh molecular weight polyethylene (UHMW-PE) , were analyzed and their undesirable degradation was related to performance of typical medical devices. Among the critical phenomena determining the biological performance of UHMW-PE and PP devices are oxidation during melt-processing and the propensity of the polymer chains to radiolyse and radio-oxidize. Polyesters and their biomedical devices , which can be designed to degrade predictably, are addressed with some focus on the less obvious determinants of performance.

Osteoclastic Resorption Of Calcium Phosphate Ceramic Thin Films, J. E. Davies, G. Shapiro, B. F. Lowenberg

Cells and Materials

Sub-micron calcium phosphate ceramic thin films were formed by vertically dipping transparent quartz plates in a particulate sol-gel suspension. Primary adult rat bone marrow cell populations were cultured on the ceramic thin films in conditions known to allow the differentiation of cells of the osteoclast lineage. Monitoring the cultures for periods of 11 to 28 days revealed the creation of resorption lacunae in the thin films by multinucleate cells. Some cultures were heated at 42 °C overnight to remove adherent cells; using bright field light microscopy (LM), after staining with silver nitrate, the degree of resorption could be easily assessed. …

Preferential Adhesion Of Urethral Bacteria From A Mixed Population To A Urinary Catheter, Gregor Reid, Christina Tieszer

Cells and Materials

The ability of uropathogens to adhere to catheters and subsequently colonize the urinary mucosa leads to urinary tract infections which afflict a large patient population. In vitro studies were carried out whereby Escherichia coli Hu734 (water contact angle 12 °) and Enterococcus faecalis (19°) were found to be highly adhesive to silicone latex urinary catheters. The addition of one of four Lactobacillus sp., with water contact angles ranging from 19-105 °, to the suspending fluid caused a 60-86% reduction in pathogen adhesion with a significant effect against E. coli, the organism most commonly found to infect the urinary tract. …

In-Vivo Reactions In Some Bioactive Glasses And Glass-Ceramics Granules, A. M. Gatti, T. Yamamuro, L. L. Hench, O. H. Andersson

Cells and Materials

Two different bioactive glasses and one glass-ceramic were implanted as granules for 2 months in rabbit muscle and for 5 months in sheep jaw in order to study the influence of the biological surroundings on the reactions of the materials.

Scanning electron microscope and energy dispersive X-ray microanalysis showed that a calcium and phosphorous-rich (CaP) surface layer (adjacent to a silicon rich-layer) forms on both glasses in both implantation sites. The glass-ceramic developed only a CaP layer. A chemical process of degradation was more evident in muscle, even though the implantation time was shorter than that in bone. For all …