Biomedical Engineering and Bioengineering Commons^™

Fracture Of An Acetabular Component Inserted Without Cement: A Case Report, R T. Trousdale, D J. Berry, Joshua J. Jacobs, Jeremy L. Gilbert

Biomedical and Chemical Engineering - All Scholarship

No abstract provided.

The Effects Of Machining On Structure And Tribological Properties Of Ultra High Molecular Weight Polyethylene For Artificial Joint Prostheses, Jinshan Song

Masters Theses

Understanding the effect of machining on the structure and property of subsurface layer of ultra high molecular weight polyethylene (UHMWPE) can significantly facilitate the increase in longevity of artificial joints. This study was performed to investigate the machining effects on the polymeric structure and tribological properties. Machining parameters include cutting speed, tool feed rate and depth of cut. Temperature rise was studied during machining to assess the extent of thermal degradation due to machining. Polymeric structure of the semicrystalline polymer was characterized using differential scanning calorimetry (DSC) in terms of melting enthalpy, crystallinity and melting temperature. Surface texture and hardness …

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 …

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 …

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 …

The Role Of Surface Characteristics In The Initial Adhesion Of Human Bone-Derived Cells On Ceramics, H. Zreiqat, O. C. Standard, T. Gengenbach, J. G. Steele, C. R. Howlett

Cells and Materials

The tissue/biomaterial interactions of three biomaterials of potential use in bone implants were studied in vitro. The mechanism of cell adherence to various ceramic substrata has been investigated by measurement of short term (90 minutes) cell attachment and spreading rate. We have determined the effect of two serum glycoproteins, fibronectin and vitronectin, on the adhesion of human bone derived cells (HBD-cells) cultured on three different types of ceramics {alumina (Al₂O₃), hydroxyapatite (HAP) and yttria-doped tetragonal zirconia polycrystal (Y-TZP)} . The attachment of HBD-cells to alumina and hydroxyapatite was approximately 60% of that to Y-TZP. Furthermore, …

Pelargonic Acid In Enhanced Oil Recovery, Hossein Noureddini, M L. Rempe

Papers in Biomaterials

Oxidation of monounsaturated iatty ac~dss,u ch as erucic and oleic acids, results in the for~nation of dibasic fatty acids, such as brassylic and azelaic acids. Dibasic acids find many inclustrial applications. Prlargon~ca cid is the co-product oi the process. Expanded use oi dibasic acids would require an expansion in the existing and possihiy new uses for pelargoriic acid and its derivatives. In this study, the potential for using pe!argonic acid in enhanced oil recovery is investigated. Experimental results are presented ior the enhanccd oil recover" by waterilooding with the aid oi a surfactan;. In sifu iormation of surfactant at the …

Biomaterials Associated Infections: The Scale Of The Problem, David J. Stickler, Robert J. C. Mclean

Cells and Materials

The biomaterials used in the manufacture of implanted prosthetic devices profoundly impair the host's ability to opsonise and phagocytose invading microbes. As a result, while these devices generally provide effective relief from painful, crippling and life-threatening disorders, they can also induce vulnerability to infection in the recipients. The surfaces of the implants are susceptible to colonisation by microbial biofilms. The cells in the biofilm.s are further protected against opsonophagocytosis and are also resistant to antibacterials. Device associated infections thus tend to be refractile to antibiotic therapy and in many cases the device has to be removed before the infection will …

High Shear Mixing Reactor For Glycerolysis, Hossein Noureddini

Papers in Biomaterials

lnrcreased ervironmental awareness and depletion of resources are driving industry to develop aiternative fuels from renewable resources that are environmentally more acceptable. Esters of fatty acids (biodiesel), derived from the transesterification of vegetable oils, have properties similar to cornponents of petroleum based diesel fuel. Cost has been a major factor in slowing down the commercialization of biodiesel. In order to improve the economy of this process two factors were investigated in this study: 1) use of beef tallow as raw material and 2) by-product utilization.

Glycerol is the by-product of the esterification process. In this work the feasibility of the …

Intergranular Corrosion-Fatigue Failure Of Cobalt-Alloy Femoral Stems. A Failure Analysis Of Two Implants, Jeremy L. Gilbert, Christine A. Buckley, Joshua J. Jacobs, Kim C. Bertin, Michael R. Zernich

Biomedical and Chemical Engineering - All Scholarship

Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the …

Viscosities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B. C. Teoh, L. Davis Clements

Papers in Biomaterials

Data for viscosity as a function of temperature from 24 to 110°C (75 to 230°F) have been measured for a number of vegetable oils (crambe, rapeseed, corn, soybean, milk- coconut, lesquerella) and eight fatty acids in the from Cg to CZZ The viscosity measurements were performed according to ASTM test methods D 445 and D 446. Several correlations were fitted to the experimental data. Correlation constants for the best fit are presented. The range of temperature in which the correlations are valid is from 24°C (75°F), or the melting point of the substance, to 110°C (230°F). The correlation constants are …

Densities Of Vegetable Oils And Fatty Acids, Hossein Noureddini, B C. Teoh, L Davis Clements

Papers in Biomaterials

Complete data for density as a function of temperature have been measured for a number of vegetable oils (cramhe, rapeseed, corn, soybean, milkweed, coconut, lesquerella), as well as eight fatty acids in the range CS to C,, at temperatures from above their melting points to llQ°C (23Q°F). The specific gravity and density measure mente were performed according to American Society for Testing and Materials (ASTM) standard test methods D 368, D 891 and D 1298 for hydrometers and a modified ASTM D 369 and D 891 for pycnometers. Correlation constants, based on the experimental data, are presented for calculating the …

Structural Characterization Of Fucoidan And Its Role In The Hemizona Assay, Manish S. Patankar

Chemistry & Biochemistry Theses & Dissertations

Fucoidan is a polysaccharide commonly found in brown algae. It is a sulfated polymer of the monosaccharide L-fucose. Fucoidan is thought to function in water retention by algae. Commercially available fucoidan is extracted from a brown algae called Eurus vesiculosus.

This polysaccharide has immense potential as a biologically active agent: (i) it exhibits anticoagulant action, (ii) it has also been reported to block retroviral replication and (iii) it is capable of blocking sperm-egg binding in sea urchin, mouse and rabbit. Recently, fucoidan has also been shown to block the interaction of human sperm and egg in the hemizona assay …

Projection Effect Errors In Biomaterials And Bone Research, K. N. Bachus, R. D. Bloebaum

Cells and Materials

Micoradiography and backscattered electron (BSE) imaging are techniques used to investigate the morphologic, histometric, and mineral content changes at the bone/biomaterials interface. Investigators have shown that the superimposition of multiple tissue layers can cause errors with both the morphologic observations and the histometric measurements of bone. The objective of this study was to document errors in the bone mineral content measurements associated with overlapping tissues.

Using a digital image analysis system, microradiographic and BSE images from canine cortical and cancellous bone were captured and analyzed. The results of this study showed that microradiography had more projection effect errors associated with …