Biomedical Engineering and Bioengineering Commons^™

An Engineering Evaluation Of Ankle Prosthetics, Christopher Thian, Stephen Tiernan, Fiona Mcevoy, Robert Flavin

Conference Papers

There are a wide range of different types of ankle replacements on the market today each with a
different mechanical design. Unfortunately the results of ankle replacements are not as good as hip
and knee replacements; this is due to the complexity of the ankle joint. In the early days of ankle
replacements some of the prosthetics only lasted 4 months. Recent developments have improved the
longevity of the replacements although, there are still many complications and failures of the
replacements, these include; the prosthetic components migrating into the bone, the components
failing due to stresses induced by the forces …

An Analysis Of The Performance Of Foams Used In Hurling Helmets, Keith Norris, Stephen Tiernan

Conference Papers

Abstract Head injuries can occur in most sporting activities. The seriousness of these injuries can vary greatly depending on the sport. Many sports such as American football, cricket, baseball and hurling try to reduce this risk by designing helmets that are suitable to be worn by the players. The National Standard Authority of Ireland (NSAI) has recently made great strides in this area with the introduction of the first comprehensive standard adopted for the sport I.S. 355:2006, which sets out new testing procedures that all new helmets must meet. The Gaelic Athletic Association (GAA) has also stated its intention to …

Potentiality Of Biogas And The Role Of Substrates In Biogas Formation Potential, Scott Shealy

Independent Study Project (ISP) Collection

Biogas infrastructure development, particularly in countries such as Vietnam, has the potential to provide great benefits to people living agrarian lifestyles in rural areas. Decentralized wastewater treatment facilities that utilize anaerobic technologies to digest organic waste for the purpose of collecting methane provide a number of benefits to centralized use as well. In both cases, users benefit from the production of methane gas, wastewater treatment, nutrient recycling, and organic fertilizers. In the case of decentralized use, as is most prevalent in Vietnam, integrated farming methods, such as the VACB model, allow farmers to reap the benefits of a wide array …

Positive Model Temperature And Its Effect On Stiffness And Percent Crystallinity Of Polypropylene, Mark Geil

Faculty Articles

No abstract provided.

Influence Of Van Der Waals Forces On Increasing The Strength And Toughness In Dynamic Fracture Of Nanofibre Networks: A Peridynamic Approach, Florin Bobaru Ph.D.

Department of Engineering Mechanics: Faculty Publications

The peridynamic method is used here to analyse the effect of van der Waals forces on the mechanical behaviour and strength and toughness properties of three-dimensional nanofibre networks under imposed stretch deformation. The peridynamic formulation allows for a natural inclusion of long-range forces (such as van der Waals forces) by considering all interactions as ‘long-range’. We use van der Waals interactions only between different fibres and do not need to model individual atoms. Fracture is introduced at the microstructural (peridynamic bond) level for the microelastic type bonds, while van der Waals bonds can reform at any time. We conduct statistical …

Licenses, Leases And Other Contractual Arrangements For The Exploration And Production Of Petroleum A Comparative Study Between Nigeria And The United States, Omolara Elumelu

LLM Theses and Essays

Much has been written about Oil and Gas leases. This paper focuses on the various Oil and Gas leases and other contractual arrangements for oil and gas exploration and production in Nigeria and the United States. The paper examines the origin, structure, development and mode of operations in both jurisdictions and concludes with a comparative analysis of both jurisdictions.

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Intracellular Signaling Networks In The Immune Response: Pathways Activated By Interleukin-2 And-4 Receptors And Their Roles In T Cell Proliferation, Kristen K. Comfort

Chemical and Materials Engineering Faculty Publications

Cells sense and respond to chemical and physical stimuli through signal transduction pathways, which mediate cell proliferation, differentiation, migration, and survival. The cytokines interleukin-2 (IL-2) and interleukin-4 (IL-4) are key regulators of the adaptive immune system, particularly influencing the clonal expansion and differentiation of T cells. At least in culture, both synergistic and antagonistic effects of IL-2 and -4 co-stimulation have been reported; the antagonism, when observed, is thought to arise from the utilization of a common subunit shared by IL-2 and IL-4 receptors. We have sought to characterize IL-2 and IL-4 signaling at the level of intracellular pathways activated …

Immobilized Pseudornonas Cepacia Lipase For Biodiesel Fuel Production From Soybean Oil,, Hossein Noureddini, X Gao, R S. Philkana

Papers in Biomaterials

No abstract provided.

A Continuous Process For The Glycerolysis Of Soybean Oil , Hossein Noureddini, D W. Harkey, M R. Gutsman

Papers in Biomaterials

A continuous process for the glycerolysis of soybean oil with pure and crude glycerol, the co-product from the transesterification of soybean oil was investigated in a pilot plant. The process was equipped with a motionless and a high-shear mixer. The experimental studies explored the effects of variations in mixing intensity, temperature, reactant flow rates, and reactant stoichiometry on the formation of MG and DC. The developed process resulted in high conversion of TC to MC. The most favorable conditions were 230°C, 40 mL/min total flow, 25 mm of reaction time, 2.5:1 molar ratio of glycerol/soybean oil, and 3600 rpm for …

Ethyl Tert-Butyl Ether And Methyl Tert-Butyl Ether: Status, Review, And Alternative Use Exploring The Environmental Issues Of Mobile, Recalcitrant, Hossein Noureddini

Papers in Biomaterials

Petroleum products leaking from under ground storage tanks have raised concerns regarding the quality of ground water resources, The concerns about the environmental behavior and rate of MTBE as an oxygenated additive prompted this iuvestigation to explore the technical characteristics of MTBE in comparison to ETBF. Evaluation of the existing literature suggests that ETBE has more favorable characteristics than MTBE. Findings in this research suggest that ETBE is a technically sound oxygenated octane enhancer, which can help refiners meet specificatios for cleaner burning gasoline.

Immobilization Of Pseudomonas Cepacia Lipase By Sol-Gel Entrapment And Its Application In The Hydrolysis Of Soybean Oil, Hossein Noureddini, X Gao, S Joshi, P R. Wagner

Papers in Biomaterials

The immobilization of Lipase PS from Pseudomonas cepacia by entrapment within a chemically inert hydrophobic sol-gel support was studied. The gel-entrapped lipase was prepared by the hydrolysis of tetramethoxysilane (TMOS) with methyltrimeth-oxysilane (MTMS), isobutyltrimethoxysilane (iso-BTMS), and n-butyltrimethoxysilane. The immobilized lipase was subsequently used in the hydrolysis of soybean oil to determine its activity, recyclability, and thermostability. The biocatalyst so prepared was equal to or better than the free enzyme in its hydrolytic activity. The catalytic activity of the entrapped lipase strongly depended on the type of precursor that was used in its preparation. The lipase entrapped within TMOS/iso-BTMS showed the …

Studies On The Formation Of Dna-Cationic Lipid Composite Films And Dna Hybridization In The Composites, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Krishna N. Ganesh

Faculty Works

The formation of composite films of double-stranded DNA and cationic lipid molecules (octadecylamine, ODA) and the hybridization of complementary single-stranded DNA molecules in such composite films are demonstrated. The immobilization of DNA is accomplished by simple immersion of a thermally evaporated ODA film in the DNA solution at close to physiological pH. The entrapment of the DNA molecules in the cationic lipid film is dominated by attractive electrostatic interaction between the negatively charged phosphate backbone of the DNA molecules and the protonated amine molecules in the thermally evaporated film and has been quantified using quartz crystal microgravimetry (QCM). Fluorescence studies …

Michaelis–Menten Kinetics For Enzymatic Depolymerization Of A Linear Polyester Synthesized From Z-Protected Glutamic Acid, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

A biodegradable polyester resin was polymerized from N-benzyloxycarbonyl-L-glutamic acid and ethylene glycol. Rhizopus delemar lipase was used as a biocatalyst for the rupture of ester bonds during the hydrolysis studies. Depoly-merization was observed to followa Michaelis–Menten mechanism, with the maximumrate of monomer formation dP/dt_max = 1.12 x 10^-8 mol/s and the rate constant K_m x 2.03 x 10^-4 mol. Subject to initial conditions described by the most probable distribution and Michaelis–Menten–type depolymerization rate expressions, population density distribution dynamics of the polymeric molecules that formed the resin were explicitly described using a deterministic approach.

System And Process For Producing Biodiesel Fuel With Reduced Viscosity And A Cloud Point Below Thirty-Two (32) Degrees Fahrenheit , Hossein Noureddini

Papers in Biomaterials

Triglycerides are reacted in a liquid phase reaction with a homogeneous basic catalyst and alcohol, such as ethanol or methanol. The reaction yields a spatially separated two phase result with an upper located non-polar phase consisting principally of transesterified triglycerides and a lower located phase consisting principally of crude glycerol and residual transesterified triglycerides. The transesterified triglycerides and/or glycerol phase is/are optionally, each separately passed through strong cationic ion exchanger(s) to remove anions, resulting in neutral product(s). The crude glycerol is then flashed to remove alcohol and is reacted with an etherifying agent, such as isobutylene or isoamylene, in the …

Energy Loss And Stiffness Properties Of Dynamic Elastic Response Prosthetic Feet, Mark Geil

Faculty Articles

No abstract provided.

Cationic Surfactant Mediated Hybridization And Hydrophobization Of Dna Molecules At The Liquid/Liquid Interface And Their Phase Transfer, Murali Sastry, Ashavani Kumar, Mrunalini Pattarkine, Vidya Ramakrishnan, Krishna N. Ganesh

Faculty Works

Hybridization of complementary oligonucleotides mediated by a cationic surfactant at the water/hexane interface leads to hydrophobic, double-helical DNA which may be readily phase transferred to the organic phase and cast into thin films on solid substrates.

Focal Osteolysis At The Junctions Of A Modular Stainless-Steel Femoral Intramedullary Nail, Darron M. Jones, Lawrence Marsh, James V. Nepola, Joshua J. Jacobs, Anastasia K. Skipor, Robert M. Urban, Jeremy L. Gilbert, Josheph A. Buckwater

Biomedical and Chemical Engineering - All Scholarship

Background:

During routine follow-up of patients treated with a three-piece stainless-steel modular femoral nail, osteolysis and periosteal reaction around the modular junctions of some of the nails were noted on radiographs. The purpose of this study was to evaluate the prevalence, etiology, and clinical relevance of these radiographic findings.

Methods:

Forty-four femoral fractures or nonunions in forty-two patients were treated with a modular stainless-steel femoral intramedullary nail. Seventeen nails were excluded, leaving twenty-seven intramedullary nails in twenty-seven patients for this study. All patients had had a femoral diaphyseal fracture; nineteen had had an acute fracture and eight, a nonunion. These …

Effects Of Compression Processing Parameters And Antioxidants On Molecular Degradation Of Biodegradable Poly-L-Lactide (Plla), Thomas J. Hannan Jr.

Masters Theses

The purpose of this research was to find a combination of poly (L-lactic acid), also known as poly-L-lactide or (PLLA) and antioxidants that would, together, produce a product whose degradation rate would be advantageous for use in biodegradable medical implants. Intrinsic viscosity tests were conducted on compression molded samples of PLLA that were molded at various processing parameters in order to find optimal parameters. The optimal processing parameters were found to be time 10 minutes, temperature 220°C, and pressure 1000 psi.

The molecular weight of PLLA sample was taken while pressure, time, and temperature were varied. As pressure increased, no …

Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh

Faculty Works

The hybridization of DNA by sequential electrostatic and hydrogen-bonding immobilization of single-stranded complementary oligonucleotides at the air-water interface with cationic Langmuir monolayers is demonstrated. The complexation of the single-stranded DNA molecules with octadecylamine (ODA) Langmuir monolayers was followed in time by monitoring the pressure-area isotherms. A large (and slow) expansion of the ODA monolayer was observed during each stage of complexation in the following sequence: primary single-stranded DNA followed by complementary single-stranded DNA followed by the intercalator, ethidium bromide. Langmuir-Blodgett (LB) films of the ODA-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), Fourier transform infrared …

Z-Protected Glutamic Acid-Based Biodegradable Thermoplastic And Thermosetting Polyesters: Synthesis And Characterization, R. M. Tadros, Hossein Noureddini, Delmar C. Timm

Papers in Biomaterials

Biodegradable polymers were formed from N-benzyloxycarbonyl-L-glutamic acid with the comonomers ethylene glycol, diglycidyl ether of 1,4-butanediol, and diglycidyl ether of bisphenol A. The three polymers were a linear and a cross-linked heterochain polyester and a cross-linked polyester that contained aromatic units within its network chains. The thermoplastic resin and the soluble fractions for the thermosetting resins were characterized by gel permeation chromatography. Conversions for carboxylic acid were determined by titrations. A quality, 22,000 molecular weight thermoplastic resin was formed. The two thermosets were cured past their gel points. Gelation analysis revealed that the relative rate constants for the sequential oxirane/acid …

Genetic Engineering Of Wood Color In Plants, Vincent Lee C. Chiang, Chung-Jui Tsai, Gopi K. Podila

Michigan Tech Patents

The invention relates to genetically engineering the wood color of woody plants by incorporation of the lignin pathway gene O-methyltransferase into the genome of the plants.

Liquid-Phase Catalytic Oxidation Of Unsaturated Fatty Acids , Hossein Noureddini, M Kanabur

Papers in Biomaterials

Liquid-phase catalytic oxidation of oleic acid with hydrogen peroxide in the presence of various transition metal/metal oxide catalysts was studied in a batch autoclave reactor. Azelaic and pelargonic acids are the major reaction products. Tungsten and tantalum and their oxides in supported and unsupported forms were used as catalysts. Alumina pellets and Kieselguhr powder were used as supports for the catalysts. Tungsten, tantalum, molybdenum, zirconium, and niobium were also examined as catalysts. Tertiary butanol was used as solvent. Experimental results concluded that tungsten and tungstic oxide are more suitable catalysts in terms of their activity and selectivity. The rate of …

A Continuous Process For The Conversion Of Vegetable Oils Into Methyl Esters Of Fatty Acids, Hossein Noureddini, D Harkey, V Medikonduru

Papers in Biomaterials

A continuous process for the transesterification of triglycerides to methyl esters was investigated in a pilot plant. The process was equipped with a motionless and a high-shear mixer. The experimental studies explored variations in the mixing intensity, stoichiometry, and catalyst concentration on the overall conversion. The combined as well as individual effect of mixers was examined. The developed process resulted in high conversions of vegetable oils into methyl esters. Conversion of triglycerides to methyl esters in excess of 98% was achieved. Larger excess amounts of alcohol favored higher conversions. The motionless and high-shear mixers each provided adequate mixing for the …

Enzymatic Glycerolysis Of Soybean Oil , Hossein Noureddini, S E. Harmeier

Papers in Biomaterials

Enzymatic glycerolysis of soybean oil was studied. Of the nine lipases that were tested in the initial screening, Pseudomonas sp. resulted in the highest yield of monoglycerides. Lipase from Pseudomonas sp. was further studied for the influence of temperature, thermal stability, enzyme/oil ratio, and glycerol/oil ratio. A full factorial optimization approach was performed. The following conditions were tested over the specified ranges: temperature (30?70°C), thermal stability (30?70°C), enzyme/oil ratio (0.05?0.2 g enzyme/10 g oil), glycerol/oil ratio (1:1?3:1 glycerol/oil molar ratio) and 1 h reaction time. The stability of the enzyme at the reaction temperature was also incorporated as a separate …

Current Concepts Review - Corrosion Of Metal Orthopaedic Implants, Joshua J. Jacobs, Jeremy L. Gilbert, Robert M. Urban

Biomedical and Chemical Engineering - All Scholarship

No abstract provided.

Production Of Ethers Of Gycerol From Crude Glycerol: The By-Product Of Biodiesel Production, Hossein Noureddini, W. R. Dailey, B. A. Hunt

Papers in Biomaterials

Methyl esters of fatty acids (also known as biodiesel), made from the transesterification of vegetable oils and animal fats with methanol, have shown a lot of promise as alternative diesel fuels. Glycerol is the inevitable by-product of the transesterification process. While there are existing markets for glycerol, a significant increase in availability of glycerol, resulting from the expanded use of vegetable oils and animal fats, would destabilize the glycerol market. Direct addition of glycerol to the fuel is not possible, however, derivatives of glycerol such as ethers have potential for use as additives with biodiesel, diesel or biodiesel-diesel blends. In …

Process For Producing Biodiesel Fuel With Reduced Viscosity And A Cloud Point Below Thirty-Two (32) Degrees Fahrenheit , Hossein Noureddini

Papers in Biomaterials

Triglycerides are reacted in a liquid phase reaction with methanol and a homogeneous basic catalyst. The reaction yields a spatially separated two phase result with an upper located non-polar phase consisting principally of non-polar methyl esters and a lower located phase consisting principally of glycerol and residual methyl esters. The glycerol phase is passed through a strong cationic ion exchanger to remove anions, resulting in a neutral product which is flashed to remove methanol and which is reacted with isobutylene in the presence of a strong acid catalyst to produce glycerol ethers. The glycerol ethers are then added back to …

Glycerolysis Of Fats And Methyl Esters., Hossein Noureddini, V Medikonduru

Papers in Biomaterials

The glycerolysis of methyl esters and triglycerides with crude glycerol. a coproduct from the transesterification of triglycerides, was studied. Three procedures were followed ior this conversion. The first procedure was a one-step glycerolysis with methyl esters. The second procedure was a two-step process. This proced~~irnev olved an initial partial glycerolysis with methyl esters, followed by fat glycerolysis. The third procedure u,as a simultaneous glycerolysis n,ith methyl esters and triglycerides. In the glycerolysis with methyl esters, the removal of methanol is vital to the production of mono- and diglycerides. Methanol was removed either by drawing vacuum on the reactor or by …

Kinetics Of Transesterification Of Soybean Oil, Hossein Noureddini, D Zhu

Papers in Biomaterials

Transesterification of soybean oil with methanol was investigated. Three stepwise and reversible reacttons are believed to occur. The effect of variations in mixing intensity (Reynolds number = 3,100 to 12,400) and temperature (30 to 70'CJ on the rate oireaction were studied while the molar ratio of alcohol to triglycerol (6:l) and the concentration of catalyst (0.20 wt% based on soybean oil) were held constant. The variations in mixing intensity appear to effect the reaction parallel to the variations in temperature. A reaction mechanism consisting of an initial mass transfer-controlled region followed by a kinetically controlled region is proposed. The experimental …