Engineering Commons^™

A Continuous Process For The Conversion Of Vegetable Oils Into Biodiesel, Hossein Noureddini, D Harkey, V Medikonduru

Papers in Biomaterials

Over the last few years fatty acid methyl esters have assumed importance as research has intensified on the utilization of vegetable oils and animal fats derivatives from liquid fuels (better known as biodiesel).Traditional batch processing has been an still is the most widely used process for this coversion. New and more efficient processing schemes. for large scale production of biodiesel for fuelfile1 purposes, is a. key for commercialization of biodiesel. In this, study a continuous process for the transesterification of triglycerides to methyl esters was investigated. This process is based a combined high shear and motionless reactor system. The experimental …

Effective Doses Of Recombinant Human Bone Morphogenetic Protein-2 In Experimental Spinal Fusion, Harvinder Sandhu, Linda E.A. Kanim, J. Michael Kabo, Jeffrey M. Toth, Erik N. Zeegen, David Liu, Rick B. Delamarter, Edgar G. Dawson

Biomedical Engineering Faculty Research and Publications

Study Design

Nineteen dogs underwent L4-L5 intertransverse process fusions with either 58 μg, 115 μg, 230 μg, 460 μg, or 920 μg of recombinant human bone morphogenetic protein-2 carried by a polylactic acid polymer. A previous study (12 dogs) compared 2300 μg of recombinant human bone morphogenetic protein-2, autogenous iliac bone, and carrier alone in this model. All fusions subsequently were compared.

Objectives

To characterize the dose-response relationship of recombinant human bone morphogenetic protein-2 in a spinal fusion model.

Summary of Background Data

Recombinant osteoinductive morphogens, such as recombinant human bone morphogenetic protein-2, are effective in vertebrate diaphyseal defect and …

Pancreatic Expression Of Interleukin-4 Abrogates Insulitis And Autoimmune Diabetes In Nonobese Diabetic (Nod) Mice., Regula Mueller, Troy Krahl, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Diabetes in nonobese diabetic (NOD) mice is a T cell-dependent autoimmune disease. The destructive activities of autoreactive T cells have been shown to be tightly regulated by effector molecules. In particular, T helper (Th) 1 cytokines have been linked to diabetes pathogenesis, whereas Th2 cytokines and the cells that release them have been postulated to be protective from disease. To test this hypothesis, we generated transgenic NOD mice that express interleukin (IL) 4 in their pancreatic beta cells under the control of the human insulin promoter. We found that transgenic NOD-IL-4 mice, both females and males, were completely protected from …

Calcium Buffering Is Required To Maintain Bone Stiffness In Saline Solution, M. B. Gustafson, R. B. Martin, V. Gibson, D. H. Storms, S. M. Stover, J. Gibeling, L. Griffin

Biomedical Engineering

This work determined whether mineral dissolution due to prolonged testing or storage of bone s~'imens in normal salint: would alter Lheir elastic modulus. In one experiment, small pieces of equine third metacarpal bone were soaked in normal saline supplemented with varying amounts of CaCI1. Changing Ca ion concentrations in the bath were monitored and the equilibrium concentration was determined. In a second experiment, the elastic moduli of twenty 4 x 10 x 100 mm equine third metacarpal beams were determined non-destructively in four-point bending. Half the beams were then soaked for 10 days in normal saline, and the other half …

In Vitro Fatigue Behavior Of The Equine Third Metacarpus: Remodeling And Microcrack Damage Analysis, R.B. Martin, V.A. Gibson, S.M. Stover, J.C. Gibeling, L.V. Griffin

Biomedical Engineering

We studied remodeling and microcrack damage in specimens of Thoroughbred racehorse third metacarpal bone that had been subjected to monotonic or fatigue failure. We asked three questions. What effects does mechanical loading have on histologically observable microcrack damage? Are there regional variations in remodeling of the equine cannon bone, and do these variations correlate with mechanical properties? To what extent are remodeling and microcrack damage age-dependent? Machined beams from the medial, lateral, and dorsal cortices were loaded to fracture in four-point bending monotonically, or cyclically at a load initially producing 10,000 microstrain. Specimens were then bulk-stained in basic fuchsin, and …

Osteonal Structure In The Equine Third Metacarpus, R. B. Martin, V. A. Gibson, S. M. Stover, J. C. Gibeling, L. V. Griffin

Biomedical Engineering

In studying the flexural fatigue properties of the equine third metacarpal (cannon) bone, we previously found that the dorsal region was weaker monotonically, but more fatigue resistant, than the lateral region. Fatigue resistance was associated with fracture surfaces which demonstrated that secondary osteons had “pulled out” of the surrounding matrix; this never happened in lateral specimens. We therefore became interested in the osteonal structure of this bone, and began to study its birefringence patterns in circularly polarized light. We found that the predominant type of secondary osteon was one in which only the outermost few lamellae were circumferential, with the …

Monoclonal Antibody Assay And Kit For Detecting Metal Cations In Body Fluids, Randall R. Carlson, Jay S. Stout, Dwane E. Wylie, Fred W. Wagner, Malcolm Riddell

Biological Process Development Facility: Staff Publications

The invention provides method and kits for detecting a metallic cation in a sample of a body fluid. The preferred method and kits include the use of at least two different types of antibodies having different specificities. In the preferred method, the sample of body fluid can be contacted with an effective amount of a capture antibody specific for a naturally occurring polypeptide that can bind the metallic cation to form a first antigen-antibody complex. An effective amount of an antibody specific for an epitope on a metallic cation-naturally occurring polypeptide complex or an antibody specific for a metallic cation …

A Review Of Prosthetic Interface Stress Investigations, Barbara Silver-Thorn, John W. Steege, Dudley S. Childress

Biomedical Engineering Faculty Research and Publications

Over the last decade, numerous experimental and numerical analyses have been conducted to investigate the stress distribution between the residual limb and prosthetic socket of persons with lower limb amputation. The objectives of these analyses have been to improve our understanding of the residual limb/prosthetic socket system, to evaluate the influence of prosthetic design parameters and alignment variations on the interface stress distribution, and to evaluate prosthetic fit. The purpose of this paper is to summarize these experimental investigations and identify associated limitations. In addition, this paper presents an overview of various computer models used to investigate the residual limb …

Parametric Analysis Using The Finite Element Method To Investigate Prosthetic Interface Stresses For Persons With Trans-Tibial Amputation, Barbara Silver-Thorn, Dudley S. Childress

Biomedical Engineering Faculty Research and Publications

A finite element (FE) model of the below-knee residual limb and prosthetic socket was created to investigate the effects of parameter variations on the interface stress distribution during static stance. This model was based upon geometric approximations of anthropometric residual limb geometry. The model was not specific to an individual with amputation, but could be scaled to approximate the limb of a particular subject. Parametric analyses were conducted to investigate the effects of prosthetic socket design and residual limb geometry on the residual limb/prosthetic socket interface stresses. Behavioral trends were illustrated via sensitivity analysis.

The results of the parametric analyses …

Il-10 Is Necessary And Sufficient For Autoimmune Diabetes In Conjunction With Nod Mhc Homozygosity., Myung-Shik Lee, Regula Mueller, Linda S. Wicker, Laurence B. Peterson, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Contrary to expectations based on in vitro experiments, we previously found that pancreatic IL-10 did not inhibit autoimmune diabetes but accelerated it in an MHC-dependent manner. Therefore, the ability of IL-10 to overcome the absence of all non-MHC diabetes susceptibility (Idd) alleles was studied in transgenic mice expressing pancreatic IL-10 backcrossed to B10.H2g7 congenic mice, which have no Idd alleles other than NOD MHC (H2g7). IL-10 transgenic backcross 1 (BC1) mice with H2g7/g7 haplotype developed clear-cut insulitis and diabetes, but neither transgenic mice with the H2g/b haplotype nor nontransgenic BC1 mice did so. Further implicating IL-10 in autoimmune diabetes, anti-IL-10 …

Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh

Faculty Works

Purple membrane (PM, λ" role="presentation">λmax" role="presentation">max 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue (λ" role="presentation">λmax" role="presentation">max 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI−" role="presentation">− and HPO42−" role="presentation">2−4. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI−" role="presentation">− and HPO42−" role="presentation">2−4 show marked pH effect. At pH 1.0 the efficiency of …

Comparison Of Different Signal Processing Algorithms To Extract The Respiration Waveform From The Ecg, David J. Caggiano

Theses

Power spectral analysis of heart rate variability is a powerful tool to measure the activity of the parasympathetic division of the autonomic nervous system noninvasively. To determine the parasympathetic activity, the frequency of respiration must be known. However, during ambulatory studies, the frequency of respiration is not acquired. To alleviate this problem, methods have been proposed in the past to derive the respiration from the ECG. Unfortunately, these previous methods are unreliable if the subject's breathing rate is uncontrolled. In this study, four methods to derive the respiration waveform from the electrocardiogram (ECG) were developed. Two leads of ECG and …

Measurement Of The Electroencephalogram (Eeg) Coherence, Atmospheric Noise, And Schumann Resonances In Group Meditation, Douglas A. Newandee

Theses

Electrical activity in the human body was investigated using EEG and ECG measurements while subjects remained with eyes open, eyes closed and in a meditation state. During these measurements, additional antennas were attached to the equipment to record atmospheric noise and signal activity simultaneously. The obtained data was analyzed and various observations were made. Processed data based on antenna signals clearly showed the presence of man-made signals, having narrow spectral widths that could be treated as atmospheric noise in the frequency range up to 50 Hz. In addition, signals clustered around 7.8, 14.1, 20.3, 26.4, and 32.5 Hz were observed …

A Mathematical Model Of Cardiovascular System With Feedback Control, Jiayu Gu

Theses

A mathematical model of human cardiovascular system is presented in this study. The closed-loop model is composed of twenty compartments which includes the left and right ventricles, and the systemic and pulmonary circulations. Two physiologic feedback control mechanisms, autoregulation of blood flow and baroreceptor reflex regulation of arterial pressure, are incorporated in the model. Autoregulation acts by changing local resistance to blood flow through metabolic and myogenic mechanisms, thereby insuring a match between oxygen supply and demand for any tissue or organ. Baroreceptors act through neural pathways to alter heart rate, contractility and peripheral resistance in order to return sudden …

Validation Of A Mathematical Model Of The Human Walking Cycle Using Parameter Identification Methods, Robert Mccann

Theses

A mathematical model of the swing phase, toe-off and heel strike is presented in this paper and is mathematically represented as a two dimensional, simple coupled pendulum system with three degrees of freedom. Lagange equations of motion are used to solve this highly idealized system. The model consists of three segments which represent the stance leg, thigh and shank. During the swing phase it is assumed that the only external forces acting on the system are gravity and viscous dissipative terms proportional to joint angular velocities. It is assumed that muscle forces act only to establish the initial limb segment …

A New Concept In Artificial Ligament And Tendons Modeling : Finite Element Analysis, Miroslaw Sokol

Theses

Reconstruction of the Anterior Cruciate Ligament (ACL) has been a major focus in sports medicine for over twenty years. Severe or unrepairable damage of the ACL due to sport injury is a major problem faced by orthopedic surgeons and engineers. To successfully replace or reconstruct an injured ACL, the mechanical properties as well as the dimensional limitation of the material used must be similar to the biological ligaments. Although excessive literature describes experimental investigation on the mechanical property and clinical application of the ligament material, there is no analytical study that describes strains, stresses, and endurance in the bone/ligament/bone complex. …

Method For Reducing The Generation Of Wear Particulates From An Implant, David A. Pienkowski

Biomedical Engineering Faculty Patents

A method is provided for reducing the amount of wear particulates generated by a total joint orthopaedic implant. The implant consists of two matched articulating components. The method includes the steps of placing the total joint orthopaedic implant in a fluid bath and articulating the implant in the fluid bath for at least 1,000 cycles. The articulation may be performed in three stages. In the first, the implant is articulated under a load of substantially 0.1-500 Newtons with sliding speeds of substantially 0.01-0.5 meters per second. During a second stage the articulation takes place under a load of substantially 200-2,500 …

Effect Of Screw Configuration And Speed On Rtd And Expansion Of Rice Extrudate, Siew-Yoong Lee, Kathryn L. Mccarthy

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The influence of screw configuration and screw speed on the residence time distribution and product expansion was determined for rice meal processed in a corotating twin screw extruder. Screw speed had strong effect on the E(t)- and F(t)-diagrams, with the mean residence time varying inversely with screw speed from 206 s to 256 s. the F-diagram was modeled by the combination of perfect mixing and plug flow. the P estimates, which express the fraction of material in plug flow, varied inversely with screw speed from 0.41 to 0.55 for the operating conditions in this study. Both screw configuration and screw …

Improved Conversion Of Plant Oils And Animal Fats Into Biodiesel And Co-Product , Praveen R. Muniyappa, Scott C. Brammer, Hossein Noureddini

Papers in Biomaterials

Increased environmental awareness and depletion of resources are driving to develop alternative fuel from renewable resources that are environmentally more acceptable. Esters of fatty acids (bio-diesel, derived from the transesterification vegetable oils, have properties similar to components of peh-oleior~. based diesel fuel Cost has been a major factor slowing the commercializatio of bio-diesel! Glycerol is the coproduct of the esterification process. In this work the feasibility of the glyc-erol of vegetable oil. with crude glycerol derived from the transesterification of the vegetable oils and animal fats was studied. Utilization of the crude co-product of the biodiesel process was investi-gated for …

Signal Processing Techniques In Heart Rate And Systolic Arterial Blood Pressure Variability Studies, Christopher O'Bara

Theses

Power spectral analysis of heart rate and systolic arterial blood pressure variability provides a window to the activity of the autonomic nervous system. To derive power spectra from raw blood pressure and electrocardiogram signals, many steps of signal processing must be performed. Most popular methods of spectral analysis require evenly spaced samples; therefore interpolation and resampling techniques must be used.

The results of the present study indicate that different interpolation techniques result in spectral distortions that vary depending upon the interpolation methods used as well as physiological parameters such as heart and respiration rate. Different interpolation methods applied to heart …

Armature Position Sensor For A Relay, G. Stephen Perreira, Richard L. Kutin, Lanny V. Griffin

Biomedical Engineering

A sensor for use with high-power solenoid-actuated relays, and for detecting and signalling relay armature position and hence the actuation state of the relay. The sensor is external to a sealed chamber in which the relay contacts and armature system are positioned, and includes a permanent magnet, the flux path of which includes the relay armature and base. Armature movement to close the relay alters the flux path to operate a reed switch adjacent the magnet, and the condition of the reed switch signals the unactuated or actuated state of the relay.

Laboratory Growth Systems In Biofilm Research, Julian W. T. Wimpenny

Cells and Materials

The huge variety of ecosystems that we collectively refer to as "biofilm" is reflected by the numerous different systems available to grow them in the laboratory. The relationship between in situ systems, microcosms and laboratory models is defined and discussed. The first two represent holistic approaches designed to assess the structure and function of particular biofilms: the last is analytical and reductionist, aiming to isolate specific functions of biofilms in order to understand properties that can apply to biofilm in general. Properties of a model can be completely understood whilst this is unlikely with natural ecosystems because of the possibility …

Initial Biodeterioration Of Silicone Rubber By C. Albicans And C. Aropicalis Strains Isolated From Voice Prostheses, H. C. Van Der Mei, B. Van De Belt-Gritter, F. Dijk, H. J. Busscher

Cells and Materials

Silicone rubber voice prostheses m patients after total laryngectomy become rapidly colonized by a biofilm, consisting of yeasts and bacteria. An especially troublesome feature of these biofilms is the ingrowth into the silicone rubber by colonizing yeasts. Microcolonies of ingrowing yeasts have been frequently observed on explanted voice prostheses after 3-4 months use. Incubation of silicone rubber samples in a modified Robbins device with a culture of Candida tropicalis, isolated from a Groningen button voice prosthesis, while passing the yeasts through a cycle of feasts (7 days) and famine (also 7 days) demonstrated, by electron microscopy, the onset of the …

Effects Of Solidification Conditions And Heat Treatment On The Microstructure And Vickers Hardness Of Pd-Cu-Ga Dental Alloys, William A. Brantley, Zhuo Cai, Stanley G. Vermilyea, Efstratios Papazoglou, John C. Mitchell, Alan B. Carr

Cells and Materials

Two representative Pd-Cu-Ga dental alloys, one with a dendritic as-cast microstructure containing a eutectic interdendritic constituent and the other with an equiaxed fine-grained as-cast microstructure containing a near-surface eutectic constituent, have been subjected to rapid quenching following casting, in addition to the conventional bench cooling recommended by the manufacturers. The quenched alloys were subsequently heat treated at temperatures of 1200°, 1500° and 1800 op that span the range of the firing cycles for dental porcelain. Scanning electron microscopic examination showed that the lamellar eutectic constituents normally present in the microstructures of the as-cast and bench-cooled alloys persisted when the alloys …

Gap Junctional Intercellular Communication In Bone, Henry J. Donahue, Monique A. Vander Molen, Clare E. Yellowley, Zhongyong Li

Cells and Materials

Gap junctional intercellular communication has been demonstrated in bone cells and may contribute to the mechanism by which osteoblasts integrate and amplify extracellular signals, both chemical (hormonal) and biophysical (electrical and mechanical). Connexin 43 (Cx43) is the predominant gap junction protein expressed by bone cells. Experiments with osteoblastic cells in which Cx43 expression was diminished by antisense transfection demonstrate that cell-to-cell coupling in osteoblastic ROS 17/2.8 cells is via gap junctions composed of Cx43. Cellular networks of these coupling deficient clones are dramatically less responsive to parathyroid hormone (PTH) suggesting that coupling contributes to hormonal responsiveness. Furthermore, PTH per se …

Stability Of Liposomes Prepared From Archaeobacterical Lipids And Phosphatidylcholine Mixtures, G. D. Sprott, C. J. Dicaire, L. P. Fleming, G. B. Patel

Cells and Materials

In vitro stabilities of liposomes prepared from the total polar lipids (TPL) of various species of Archaeobacteria were compared with those made from egg phosphatidylcholine (EPC) and from mixtures of TPLIEPC. Stability was monitored by measuring the extent of leakage of entrapped dyes. Liposomes prepared from exclusively archaeobacteriallipids (coined archaeosomes), particularly those containing the bilayer spanning tetraether lipids, were generally stable to conditions such as storage at 37°C for greater than 7 days, exposure to phospholipase A₂, incubation with serum, and, to some extent, exposure to bile salts. In contrast, EPC liposomes were generally unstable to these conditions, …

Investigation Of Bone And Calcium Phosphate Coatings And Crystallinity Determination Using Raman Microspectroscopy, C. J. De Grauw, J. D. De Bruijn, C. Otto, J. Greve

Cells and Materials

Conventional spontaneous Raman micro-spectroscopy was used for the investigation of bone and calcium phosphate coatings on bone-implant surfaces. Chemical and structural changes at the bone-coating interface could be monitored on a microscopic scale. It was shown that the crystallinity did not vary within the crystalline apatite and amorphous calcium phosphate coatings, while the density within each coating did vary. Different degrees of crystallinity in coatings were investigated for a series of plasma-sprayed apatite coatings. It is concluded that Raman microspectroscopy is an easy non-destructive way to obtain information about the apatite structure and the degree of crystallinity.

Application Of Confocal Laser Scanning Microscopy To Cytocompatibility Testing Of Potential Orthopaedic Materials In Immortalised Osteoblast-Like Cell Lines, R. Macnair, R. Wilkinson, C. Macdonald, I. Goldie, D. B. Jones, M. H. Grant

Cells and Materials

Confocal laser scanning microscopy (CLSM) was used in conjunction with in vitro cell culture to investigate cellular interactions with orthopaedic biomaterials. Transfected rat and human osteoblasts were seeded on two potential isoelastic hip prosthesis materials, carbon fibre reinforced polyetheretherketone (PEEK) and epoxy. Titanium 318 alloy was employed as a control. Determination of the material surface contour, an important factor influencing cellular adhesion, proliferation and function, was performed using the industry standard Talysurf® and compared to analogous results obtained using the CLSM. The latter technique consistently gave higher values of material roughness but offers the advantage that it can be used …

Letter To The Editor: Biocompatibility And Reactogenicity Of Materials: A Semantic And Logical Analysis Of Definitions And Their Practical Significance, Leonid I. Slutskii, Janis J. Vetra

Cells and Materials

Any biomaterial implanted into a living body elicits a distinct local reaction. This reaction depends on the physical, physico-chemical and chemical properties of the material. The obvious term to designate this inherent property of a biomaterial to induce a local reaction is reactogenicity. Reactogenicity of a biomaterial is one of the main factors determining (together with other properties of the implanted device) the bio(non)compatibility of the implant. Such amplification of terminology which establishes differences between biocompatibility as a generalized characteristic of biomaterials in all their interrelations with the host's organism and the influences on local processes around implants, makes the …

A Microstructural Investigation Of Calcium Hydroxyapatites Synthesized From Cahpo4•2h2o And Ca4(Po4)2o, Kevor S. Tenhuisen, Boyd A. Clark, Maria Klimkiewicz, Paul W. Brown

Cells and Materials

This investigation determined the effects of reaction temperature and bulk composition on the microstructural features of hydroxyapatites (HAp) synthesized from reaction between particulate CaHPO₄·2H₂O and Ca₄(PO₄)₂O. These data were used in combination with previous work to further elucidate the mechanistic reaction path taken by these calcium phosphate cements. HAps having two different compositions (Ca/P = 1.50 and 1.67) were synthesized between 15.0 and 70.0°C. All reactions reached completion as indicated by X-ray diffraction. Single point nitrogen absorption was performed on all samples to determine specific surface areas. The HAp which …