Engineering Commons^™

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 …

Multiscale Modeling Of Recrystallization, A. W. Godfrey, E. A. Holm, D. A. Hughes, M. A. Miodownik, Richard Alan Lesar

Richard Alan Lesar

We propose a multi length scale approach to modeling recrystallization which links a dislocation model, a cell growth model and a macroscopic model. Although this methodology and linking framework will be applied to recrystallization, it is also applicable to other types of phase transformations in bulk and layered materials. Critical processes such as the dislocation structure evolution, nucleation, the evolution of crystal orientations into a preferred texture, and grain size evolution all operate at different length scales. In this paper we focus on incorporating experimental measurements of dislocation substructures, misorientation measurements of dislocation boundaries, and dislocation simulations into a mesoscopic …

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 …

Method For Improving Consolidation Of Powder Resin, David A. Pienkowski, Eric A. Grulke, Robert J. Jacob

Biomedical Engineering Faculty Patents

A method for improving consolidation of powder resin is provided. The method broadly includes the steps of: (1) sorting particles of the powder resin according to their diameter; (2) combining the sorted particles having a first diameter D1 with the sorted particles having a second diameter D2 so as to form a particle mixture; (3) applying a vibration to the particle mixture; (4) heating the particle mixture; and (5) delivering the particle mixture through a nozzle or into a mold. The particle diameters D1 and D2 are chosen so that once combined there is optimal close packing of the three-dimensional …

Analysis Of Multi-Lead Qt Dispersion By Means Of An Algorithm Implemented On Labview, Zafer Sahinoglu

Theses

QT dispersion measurement is significant in diagnostic ECG, and several methods are proposed in the literature to implement QT measurement.

This study consists of two parts: The first part was the development of an algorithm to measure both QT interval and QT dispersion. To check the reliability of the algorithm, 25 single channel ECGs were recorded and their QT intervals were computed. On two subjects, three and four lead ECG data were recorded respectively and their QT dispersions were statistically analyzed. Another part of this study dealt with the effect of the electric dipole of the heart on QT dispersion. …

Measurement Of The Baroreceptor Sensitivity Index (Brsi) In The Frequency Domains, Tanvir Raquib

Theses

Time domain analysis for calculating the Baroreceptor Sensitivity Index (BRSI) did not always provide an accurate result. It also had another limitation in that it could not show the influence of the autonomic nervous system for different subjects. The correlation coefficient is a mechanism that was used to either accept or reject the BRSI values in the time domain but the correlation coefficient values changed drastically depending on how many sample points were selected for the calculation.

On the other hand, frequency domain analysis for the BRSI calculation was relatively easier and provided more accurate information compared to the time …

Runoff And Erosion Following Field Application Of Beef Cattle Manure And Compost, John E. Gilley, Bahman Eghball

Biological Systems Engineering: Papers and Publications

Manure or compost from beef cattle feedlots can be excellent sources of nutrients and organic matter when added to soils. This study was conducted to determine the effect of a single application of manure and compost on runoff and erosion under no-till and tillage conditions. Tillage consisted of a single disking operation up and down the slope on a Sharpsburg soil which was cropped to grain sorghum or wheat the previous season. Manure and compost were applied at rates required to meet corn fertility requirements. Additional experimental treatments included the application of inorganic fertilizer and an untreated check. The addition …

Development Of A Practical And Effective Technique To Determine The Complete Level Of Autonomic Neural Activity During Stress, Vikki Hazelwood

Theses

Clinical evidence exists to suggest that an individual's level of stress contributes to the state of many physiological and psychological disorders, The autonomic nervous system, by adjusting parasympathetic and sympathetic activity, is attributed with the control over an individual's level of neural stress. Therefore, it is desired to develop a better and quantitative understanding of the stress! autonomic system mechanism.

Previous work has been done to gain a partial understanding of such activity. The primary objective for this study is to complement and advance the previous work by determining whether there is other physiological data which could reveal more about …

Mathematical Model Of Human Sit-To-Stand And Stand-To-Sit Motion Analysis, Jayeshkumar Gandhi

Theses

In designing a device for an amputee, it is important to find those underlying principles which determine the normal human sit-to-stand task. For this purpose we have developed a mathematical model of human sit-to-stand movement, which it is possible to predict the minimum mechanical energy consumption to move from the sit-to-stand position.

To the best of author's knowledge, this thesis represents the first time that the periodic motion of stand-to-sit and sit-to-stand movements have been mathematically modeled by a simple mechanical system. A complex model, such as the one used by Seireg and Arvikar (1973) [1] that contained 31 muscles …

Quantitative Estimation Of Heparin Content On Biological Pericadium Tissue Using In Vitro Anti-Factor Xa Assay, Jean-Claude Simeon

Theses

Shelhigh Inc. (Millburn, NJ) has developed a new heparin binding technique to biological tissues. The technique seems to bind heparin to tissues in a more permanent fashion. Shelhigh's heparinized biological tissues are intended for use in long term implants. This investigation was undertaken to assess whether heparin leaching is prevalent when tissues are quarantine for long shelflife at room temperature, whether tissues maintained thromboresistance properties when in contact with plasma and to estimate heparin content of the tissues.

The study used anti-factor Xa assaying methods: clotting time and chromogenic factor Xa sensitive substrate in order to fulfill the aforementioned objectives. …

Quantification Of Mitral Regurgitation With Mr Phase-Velocity Mapping Using A Control Volume Method, George P. Chatzimavroudis, John N. Oshinski, Roderic I. Pettigrew, Peter G. Walker, Robert H. Franch, Ajit P. Yoganathan

Chemical & Biomedical Engineering Faculty Publications

Reliable diagnosis and quantification of mitral regurgitation are important for patient management and for optimizing the time for surgery. Previous methods have often provided suboptimal results. The aim of this in vitro study was to evaluate MR phase-velocity mapping in quantifying the mitral regurgitant volume (MRV) using a control volume (CV) method. A number of contiguous slices were acquired with all three velocity components measured. A CV was then selected, encompassing the regurgitant orifice. Mass conservation dictates that the net inflow into the CV should be equal to the regurgitant flow. Results showed that a CV, the boundary voxels of …

Local Mechanical Spectroscopy With Nanometer-Scale Lateral Resolution, Nancy Burnham, F Oulevey, G Gremaud, A Semoroz, Aj Kulik, E Dupas, D Gourdon

Nancy A. Burnham

A new technique has been developed to probe the viscoelastic and anelastic properties of submicron phases of inhomogeneous materials. The measurement gives information related to the internal friction and to the variations of the dynamic modulus of nanometer-sized volumes. It is then the nanoscale equivalent to mechanical spectroscopy, a well-known macroscopic technique for materials studies, also sometimes called dynamic mechanical (thermal) analysis. The technique is based on a scanning force microscope, using the principle of scanning local-acceleration microscopy (SLAM), and allows the sample temperature to be changed. It is called variable-temperature SLAM, abbreviated T-SLAM. According to a recent proposition to …

Multidirectional Ecg Coherent Optimal Timing Of Defibrillation Shocks, Abhijit R. Patwardhan, Fabio M. Leonelli

Biomedical Engineering Faculty Patents

A method for of delivering a defibrillation shock to a heart at an optimal time to stop ventricular fibrillation which involves obtaining an electrocardiogram of a heart in at least two directions, determining a time-coherency of the electrocardiogram based upon each of the at least two directions, and computing a tracking function from the time-coherency. An optimal time to apply a defibrillation shock to the heart is determined by locating a local maximum on the tracking function. The method utilizes spacia characteristics of the ventricular fibrillation. The method can be incorporated into implantable cardioverter defibrillators utilizing existing hardware technology.

Friction Anisotropy And Asymmetry Of A Compliant Monolayer Induced By A Small Molecular Tilt, Nancy Burnham, M Liley, D. Gourdon, Dimitrios Stamou, U Meseth, T Fischer, C Lautz, H Stahlberg, H Vogel, C Duschl

Nancy A. Burnham

Lateral force microscopy in the wearless regime was used to study the friction behavior of a lipid monolayer on mica. In the monolayer, condensed domains with long-range orientational order of the lipid molecules were present. The domains revealed unexpectedly strong friction anisotropies and non-negligible friction asymmetries. The angular dependency of these effects correlated well with the tilt direction of the alkyl chains of the monolayer, as determined by electron diffraction and Brewster angle microscopy. The molecular tilt causing these frictional effects was less than 15 degrees, demonstrating that even small molecular tilts can make a major contribution to friction.

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

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 wherein at least one of the components is made of polymer or other material with similar physical properties. 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 …

Biodiesel Fuel From Animal Fat. Ancillary Studies On Transesterification Of Beef Tallow, Fangrui Ma, L. Davis Clements, Milford Hanna

Nebraska Center for Biotechnology: Faculty and Staff Publications

Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 °C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 °C. For the distribution of methanol between beef tallow methyl esters (BTME) and glycerol, the percentage of total methanol in the glycerol phase was higher than that in the fatty acid methyl ester (FAME) phase in a simulated system at room temperature. At 65-80 °C, however, the percentage of total methanol in FAME (60% (w/w)) was higher …

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.

Tissue Engineering: At The Interface Between Engineering, Biology And Medicine, Brenda Ogle, Priti Gairola, Jodi Balik, Daniel L. Mooradian

Journal of the Minnesota Academy of Science

No abstract provided.

Multiresolution Detection Of Spiculated Lesions In Digital Mammograms, Sheng Liu, Charles F. Babbs, Edward Delp

Weldon School of Biomedical Engineering Faculty Publications

In this paper we present a novel multiresolution scheme for the detection of spiculated lesions in digital mammograms. First, a multiresolution representation of the original mammogram is obtained using a linear phase nonseparable 2-D wavelet transform. A set of features is then extracted at each resolution in the wavelet pyramid for every pixel. This approach addresses the difficulty of predetermining the neighborhood size for feature extraction to characterize objects that may appear in different sizes. Detection is performed from the coarsest resolution to the finest resolution using a binary tree classifier. This top-down approach requires less computation by starting with …

Controlled Environment Potentiostat To Study Solid-Aqueous Systems, R A. Petrie, P. R. Grossl, Ronald C. Sims

Biological Engineering Faculty Publications

We designed a redox apparatus that controls electropotenial (Eh), pH, and temperature. The apparatus is fully automated and can be assembled from equipment found in most soil analytical laboratories. The reactor can maintain environmental conditions used to evaluate the chemical fate of contaminants under natural conditions (natural attenuation) or adjust them to a new steady state to evaluate the effect of engineered remediation on a subsurface system. It can operate within a wide range of redox potential values (−400 to 400 mV) and at any pH value. The stability and accuracy of the instrument was tested by performing Eh-pH titrations …

Relationships Among Grain Sorghum Quality Factors, Roberto A. Buffo, Curtis L. Weller, Anne M. Parkhurst

Biological Systems Engineering: Papers and Publications

Correlations among grain sorghum quality factors (proximate composition, physical properties, and water absorption properties) were evaluated. Samples of 46 commercial hybrids (24 and 22 from crop years 1993 and 1994) were analyzed for starch, protein, crude free fat, test weight, absolute density, 1,000 kernel weight, percent kernel abraded, water absorption index, initial water absorption rate, and moisture saturation point. Test weight, absolute density, and percent kernel abraded were positively correlated among themselves (r > 0.5). Protein was negatively correlated with both test weight and absolute density (r < -0.5), while moisture saturation point showed negative correlations with test weight, absolute density, 1,000 kernel weight, and percent kernel abraded (r < -0.4). Principal component factor analysis through the covariance matrix explained 95% of the total variation of quality factors among hybrids (two factors), and, through the correlation matrix, 85% of the total variation (five factors). Water absorption rate decreased with increasing starch content of grain sorghum kernels as water absorption rate increased and amount of water for saturation decreased with softening of kernels.

Design Of Tapered Augers For Uniform Unloading Particulate Material From Rectangular Cross-Section Containers, M. S. Burr, Michael F. Kocher, David D. Jones

Biological Systems Engineering: Papers and Publications

The design equation for an auger to provide uniform unloading of particulate material from a container with a rectangular cross-section (Jones and Kocher, 1995) was revised to account for the minimum flighting height that could effectively unload particles with a known average smallest diameter. A minimum flighting height that was about 64% of the average smallest diameter of the particles was experimentally determined to obtain mean slopes of the top surface of the material not significantly different from zero for screened soybeans. A linear taper that best fit the square root curve for the inside diameter of the auger was …

Production Of Ethers Of Glycerol From Crude Glycerol - The By-Product Of Biodlesel 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 byproduct of the trans-esterification process. While there are existing markets for glycerol, a significant increase in availability of glycerol, re-sulting 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 …

Sensory Changes In Adults With Unilateral Transtibial Amputation, Judith B. Kosasih, Barbara Silver-Thorn

Biomedical Engineering Faculty Research and Publications

The purpose of this study was to describe the sensory changes in adults with unilateral transtibial amputation

(TTA), as any loss of sensation may have significant impact on the successful use of a prosthesis. Sensory modalities of light touch, deep pressure, vibration, and superficial pain (pinprick) were examined on the residual and contralateral limbs of 16 veterans with TTA. Six subjects demonstrated normal sensation on the contralateral limb and impaired sensation of superficial pain, vibration, and/or light touch on the residual limb. Superficial pain was the most frequently impaired sensation, and vibration and superficial pain sensation appeared to be age-dependent, …

Cryptococcus Neoformans Chemotyping By Quantitative Analysis Of H-1 Nuclear Magnetic Resonance Spectra Of Glucuronoxylomannans With A Computer-Simulated Artificial Neural Network, Robert Cherniak, Homayoun Valafar, Laura C. Morris, Faramarz Valafar

Faculty Publications

The complete assignment of the proton chemical shifts obtained by nuclear magnetic resonance (NMR) spectroscopy of de-O-acetylated glucuronoxylomannans (GXMs) from Cryptococcus neoformanspermitted the high-resolution determination of the total structure of any GXM. Six structural motifs based on an α-(1→3)-mannotriose substituted with variable quantities of 2-O-β- and 4-O-β-xylopyranosyl and 2-O-β-glucopyranosyluronic acid were identified. The chemical shifts of only the anomeric protons of the mannosyl residues served as structure reporter groups (SRG) for the identification and quantitation of the six triads present in any GXM. The assigned protons for the mannosyl residues resonated at clearly …

Opto-Electronic Sensor System For Rapid Evaluation Of Planter Seed Spacing Uniformity, Michael F. Kocher, Yubin Lan, Changhe Chen, John A. Smith

Biological Systems Engineering: Papers and Publications

An opto-electronic seed spacing evaluation system that measured time intervals between seeds and detected front-to-back location of seed drop events relative to the planter was used to rapidly determine planter seed spacing uniformity in the laboratory. The seed detection sensor for the opto-electronic system consisted of a rectangular photogate with 24 phototransistors receiving light beams from 24 LEDs opposite to them. The system also included circuitry to interface the photogate with a digital I/O board in a personal computer. The opto-electronic system was tested with three planter configurations. During the tests, the photogate was positioned beneath the seed drop tube …

Gamma-Ray Imaging Detector For Small Animal Research, Andrew Gerard Weisenberger

Dissertations, Theses, and Masters Projects

A novel radiation imaging technology for in vivo molecular imaging in small mammals is described. The goal of this project is to develop a new type of imaging detector system suitable for real-time in vivo probe imaging studies in small animals. This technology takes advantage of the gamma-ray and x-ray emission properties of the radioisotope iodine 125 (125I) which is employed as the label for molecular probes. The radioisotope 125I is a gamma-ray emitting radioisotope that can be commercially obtained already attached to biomedically interesting molecules to be used as tracers for biomedical and molecular biology research.;The isotope 125I decays …

Approximate Analytical Solution For Seepage Flow With Fractional Derivatives In Porous Media, Ji-Huan He

Ji-Huan He

In this paper, a new and more exact model for seepage flow in porous media with fractional derivatives has been proposed, which has modified the well-known Darcy law and overcome the continuity assumption of seepage flow. A new kind of analytical method of nonlinear problem called the variational iteration method is described and used to give approximate solutions of the problem. The results show that the proposed iteration method, requiring no linearization or small perturbation, is very effective and convenient.

Characterization Of Biological Systems Via Relaxometric And Diffusimetric Nmr, Sam S. Han

Sam Han

Biological systems are characterized using various relaxometric and diffusimetric nuclear magnetic resonance techniques.