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Biomedical Engineering and Bioengineering

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Articles 8971 - 9000 of 11460

Full-Text Articles in Engineering

Targeted Nanoparticles For Cancer Therapy: Promises And Challenge, Kytai Truong Nguyen Jan 2011

Targeted Nanoparticles For Cancer Therapy: Promises And Challenge, Kytai Truong Nguyen

Bioengineering Faculty Publications - Archive

No abstract provided.


Investigation Of Microbubble/Droplet Formation In Cross-Flow And Co-Flow Micro Devices, Tom J. John Jan 2011

Investigation Of Microbubble/Droplet Formation In Cross-Flow And Co-Flow Micro Devices, Tom J. John

Doctoral Dissertations

The primary goal of the work presented in this dissertation is to generate microbubbles of a diameter of less than 15μm inside micro channels. In order to achieve this detailed understanding, the facts and limitations behind the generation of microbubbles inside a micro channel are determined from existing literature. The major limitations of the current bubble/droplet generators are found to be the bubble confinement effect, the merging of bubbles, the difficulty in determining bubble diameter and the need for smaller channels to generate smaller bubbles. A device eliminating these drawbacks is conceptualized, and its feasibility is studied using COMSOL® and …


Comparison Of Brain Activity In The Prefrontal Cortex During Digit Span Task Between Student Veterans With Post Traumatic Stress Disorder And Controls Using Functional Near Infrared Spectroscopy, Bejoy Mathai Jan 2011

Comparison Of Brain Activity In The Prefrontal Cortex During Digit Span Task Between Student Veterans With Post Traumatic Stress Disorder And Controls Using Functional Near Infrared Spectroscopy, Bejoy Mathai

Bioengineering Theses - Archive

Near Infrared Spectroscopy (NIRS) is an optical non-invasive imaging technique which makes use of infrared light at particular wavelengths to measure the changes in concentrations of oxygenated blood haemoglobin (HbO) as well as the deoxygenated blood haemoglobin (HbR). Making use of this technique to acquire measurements during different functional activities subcategorises it into the novel and fast developing field of Functional Near Infrared Spectroscopy (fNIRS). In my study I have made use of this novel imaging technique to study the pre-frontal cortex while the subject performs the functional task of digit span task consisting of the forward digit span and …


Composition-Structure-Property Relationships For Experimental Composite Nerve Guidance Conduits, Xiaofang Zhang Jan 2011

Composition-Structure-Property Relationships For Experimental Composite Nerve Guidance Conduits, Xiaofang Zhang

Theses

Many Nerve Guidance Conduits (NGCs) have been approved by the Food and Drug Administration (FDA) as an alternative to nerve autografting for guiding peripheral nerve regeneration. However these materials offer little therapeutic potential for favourable axon growth environment, and difficulty in balancing the mechanical properties and the degradation rate of the implanted material is also a contemporary challenge. This project involved the design of experimental composite NGCs comprising glass particles and Pluronic FI27 in the copolymer (poly(lactic-co-glycolic acid)) and examined the composition-structure-property relationships for such materials. Three glasses (0.5Si-(x) Na-0.2Ca-0.13Zn-(0.17-x) Ce) (0.0.04 > x > 0.14) were produced. Glasses were characterised using …


The Bioactivity And Ion Release Of Titanium-Containing Glass Polyalkenoate Cements For Medical Applications, A. W. Wren, N. M. Cummins, F. R. Laffir, S. P. Hudson, Mark R. Towler Jan 2011

The Bioactivity And Ion Release Of Titanium-Containing Glass Polyalkenoate Cements For Medical Applications, A. W. Wren, N. M. Cummins, F. R. Laffir, S. P. Hudson, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ion release profiles and bioactivity of a series of Ti containing glass polyalkenoate cements. Characterization revealed each material to be amorphous with a Tg in the region of 650-660°C. The network connectivity decreased (1.83-1.35) with the addition of TiO2 which was also evident with analysis by X-ray photoelectron spectroscopy. Ion release from cements were determined using atomic absorption spectroscopy for zinc (Zn2+), calcium (Ca2+), strontium (Sr2+), Silica (Si4+) and titanium (Ti4+). Ions such as Zn2+ (0.1-2.0 mg/l), Ca2+ (2.0-8.3 mg/l,) Sr2+ (0.1-3.9 mg/l), and Si4+ …


Nanosecond Pulse Electrical Fields Used In Conjunction With Multi-Wall Carbon Nanotubes As A Potential Tumor Treatment, Michael W. Stacey, Christopher Osgood, Bhargava Subhash Kalluri, Wei Cao, Hani Elsayed-Ali, Tarek Abdel-Fattah Jan 2011

Nanosecond Pulse Electrical Fields Used In Conjunction With Multi-Wall Carbon Nanotubes As A Potential Tumor Treatment, Michael W. Stacey, Christopher Osgood, Bhargava Subhash Kalluri, Wei Cao, Hani Elsayed-Ali, Tarek Abdel-Fattah

Bioelectrics Publications

The objectives of this communication were to fabricate pure samples of multi-walled carbon nanotubes (MWCNTs) and to determine their toxicity in tumor cell lines. MWCNTs were dispersed in a concentration of the surfactant T80 that was minimally toxic. Cell-type variation in toxicity to MWCNTs was observed but was not significantly different to unexposed controls. Additionally, we investigated the increased cell killing of the pancreatic cancer cell line PANC1 when exposed to ultrashort (nanosecond) pulsed electrical fields (nsPEF) in the presence of MWCNTs as a potential form of cancer therapy. We hypothesized that the unique electronic properties of MWCNTs disrupt cell …


Nanosecond Pulsed Electric Field Induced Cytoskeleton, Nuclear Membrane And Telomere Damage Adversely Impact Cell Survival, Michael W. Stacey, P. Fox, S. Buescher, Juergen F. Kolb Jan 2011

Nanosecond Pulsed Electric Field Induced Cytoskeleton, Nuclear Membrane And Telomere Damage Adversely Impact Cell Survival, Michael W. Stacey, P. Fox, S. Buescher, Juergen F. Kolb

Bioelectrics Publications

We investigated the effects of nanosecond pulsed electric fields (nsPEF) on three human cell lines and demonstrated cell shrinkage, breakdown of the cytoskeleton, nuclear membrane and chromosomal telomere damage. There was a differential response between cell types coinciding with cell survival. Jurkat cells showed cytoskeleton, nuclear membrane and telomere damage that severely impacted cell survival compared to two adherent cell lines. Interestingly, disruption of the actin cytoskeleton in adherent cells prior to nsPEF exposure significantly reduced cell survival. We conclude that nsPEF applications are able to induce damage to the cytoskeleton and nuclear membrane. Telomere sequences, regions that tether and …


Electro-Gene Transfer To Skin Using A Noninvasive Multielectrode Array, Siqi Guo, Amy Donate, Gaurav Basu, Cathryn Lundberg, Loree Heller, Richard Heller Jan 2011

Electro-Gene Transfer To Skin Using A Noninvasive Multielectrode Array, Siqi Guo, Amy Donate, Gaurav Basu, Cathryn Lundberg, Loree Heller, Richard Heller

Bioelectrics Publications

Because of its large surface area and easy access for both delivery and monitoring, the skin is an attractive target for gene therapy for cutaneous diseases, vaccinations and several metabolic disorders. The critical factors for DNA delivery to the skin by electroporation (EP) are effective expression levels and minimal or no tissue damage. Here, we evaluated the non-invasive multielectrode array (MEA) for gene electrotransfer. For these studies we utilized a guinea pig model, which has been shown to have a similar thickness and structure to human skin. Our results demonstrate significantly increased gene expression 2 to 3 logs above injection …


Robotic Testing Of Proximal Tibio-Fibular Joint Kinematics For Measuring Instability Following Total Knee Arthroplasty, Wael K. Barsoum, Ho H. Lee, Trevor G. Murray, Robb Colbrunn, Alison K. Klika, S. Butler, Antonie J. Van Den Bogert Jan 2011

Robotic Testing Of Proximal Tibio-Fibular Joint Kinematics For Measuring Instability Following Total Knee Arthroplasty, Wael K. Barsoum, Ho H. Lee, Trevor G. Murray, Robb Colbrunn, Alison K. Klika, S. Butler, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Pain secondary to instability in total knee arthroplasty (TKA) has been shown to be major cause of early failure. In this study, we focused on the effect of instability in TKA on the proximal tibio-fibular joint (PTFJ). We used a robotics model to compare the biomechanics of the PTFJ in the native knee, an appropriately balanced TKA, and an unbalanced TKA. The tibia (n = 5) was mounted to a six-degree-of-freedom force/torque sensor and the femur was moved by a robotic manipulator. Motion at the PTFJ was recorded with a high-resolution digital camera system. After establishing a neutral position, …


A Multi-Species Analysis Of Biomechanical Responses Of The Head To A Shock Wave, Richard Bolander Jan 2011

A Multi-Species Analysis Of Biomechanical Responses Of The Head To A Shock Wave, Richard Bolander

Wayne State University Dissertations

Shock wave induced brain injury remains a field of research that has great consequences for the rehabilitation of soldiers and civilians that are exposed to an explosion. As such, for the research to be successful in developing strategies to mitigate the effects of these injuries, appropriate research methods need to be developed. Animal models are currently employed to understand the brain's response to a shock wave exposure. Unfortunately no criteria have been established that indicates in what way the mechanical inputs that the cells in an animal's brain are subjected to are similar to a human. The purpose of this …


Supercritical Carbon Dioxide-Processed Resorbable Polymer Nanocomposites For Bone Graft Substitute Applications, Kevin Baker Jan 2011

Supercritical Carbon Dioxide-Processed Resorbable Polymer Nanocomposites For Bone Graft Substitute Applications, Kevin Baker

Wayne State University Dissertations

Numerous clinical situations necessitate the use of bone graft materials to enhance bone formation. While autologous and allogenic materials are considered the gold standards in the setting of fracture healing and spine fusion, their disadvantages, which include donor site morbidity and finite supply have stimulated research and development of novel bone graft substitute materials. Among the most promising candidate materials are resorbable polymers, composed of lactic and/or glycolic acid. While the characteristics of these materials, such as predictable degradation kinetics and biocompatibility, make them an excellent choice for bone graft substitute applications, they lack mechanical strength when synthesized with the …


Computational Simulation Of Skull Fracture Patterns In Pediatric Subjects Using A Porcine Model, Christina Devito Wagner Jan 2011

Computational Simulation Of Skull Fracture Patterns In Pediatric Subjects Using A Porcine Model, Christina Devito Wagner

Wayne State University Dissertations

In cases of suspected child abuse with skeletal trauma, it is often the role of the injury biomechanist, forensic pathologist, clinical radiologist, and forensic anthropologist to determine the mechanism of injury when the child victims cannot speak for themselves. This is a challenging task, especially for the head, as comprehensive biomechanical data on skull fracture in infants and children do not currently exist, and frequently the determination regarding cause of injury is based on anecdotal evidence from the medical literature and unsubstantiated eyewitness accounts. The current process may result in unreliable autopsy interpretation and miscarriages of justice due to a …


Perforation Of Arterial Tissue Using Kilohertz Frequency Ultrasound Delivered Via Wire Waveguides, Mark Wylie, Garrett Mcguinness, Graham Gavin Jan 2011

Perforation Of Arterial Tissue Using Kilohertz Frequency Ultrasound Delivered Via Wire Waveguides, Mark Wylie, Garrett Mcguinness, Graham Gavin

Conference Papers

An emerging technology proposes the use of low frequency-high power ultrasound transmitted via wire waveguides for the disruption and ablation of atherosclerotic lesions, more specifically advanced fibrous or calcified plaques such as chronic total occlusions (CTO). This energy delivery selectively ablates rigid diseased tissue by means of direct mechanical contact, cavitation and other forces generated by the intense dynamic pressure fields generated.

The first clinical device using this energy delivery was granted FDA approval in 2007 [1] for the ablation of CTOs and most research to date has focused on ablation and disruption of hard, fibrous or calcified tissues [2]. …


On Improving Electrooculogram-Based Computer Mouse Systems: The Accelerometer Trigger, Johnalan Keegan, Edward Burke, James Condron, Eugene Coyle Jan 2011

On Improving Electrooculogram-Based Computer Mouse Systems: The Accelerometer Trigger, Johnalan Keegan, Edward Burke, James Condron, Eugene Coyle

Conference Papers

Eye tracking is a well-established method of computer control for profoundly paralysed people (Anson et al., 2002). Cameras are commonly used to track eye movements (Morimoto et al., 2005) but one alternative is the bioelectrical signal known as the electrooculogram (EOG). There are some EOG mouse control systems that facilitate the use of GUI applications, but certain actions, which are straightforward using a conventional mouse, remain impossible. Unless the eyes are tracking a target, they move in saccades (jumps), making it impossible to voluntarily trace out smooth trajectories with one's gaze, as would be required to draw a smooth curve. …


A Novel Cable-Driven Robotic Training Improves Locomotor Function In Individuals Post-Stroke, Ming Wu, Jill M. Landry, Sheng-Che Yen, Brian D. Schmit, T. George Hornby, Miriam Rafferty Jan 2011

A Novel Cable-Driven Robotic Training Improves Locomotor Function In Individuals Post-Stroke, Ming Wu, Jill M. Landry, Sheng-Che Yen, Brian D. Schmit, T. George Hornby, Miriam Rafferty

Biomedical Engineering Faculty Research and Publications

A novel cable-driven robotic gait training system has been tested to improve the locomotor function in individuals post stroke. Seven subjects with chronic stroke were recruited to participate in this 6 weeks robot-assisted treadmill training paradigm. A controlled assistance force was applied to the paretic leg at the ankle through a cable-driven robotic system. The force was applied from late stance to mid-swing during treadmill training. Body weight support was provided as necessary to prevent knee buckling or toe drag. Subjects were trained 3 times a week for 6 weeks. Overground gait speed, 6 minute walking distance, and balance were …


Effects Of Acute Rho Kinase Inhibition On Chronic Hypoxia-Induced Changes In Proximal And Distal Pulmonary Arterial Structure And Function, Rebecca R. Vanderpool, Ah Ram Kim, Robert C. Molthen, Naomi Chesler Jan 2011

Effects Of Acute Rho Kinase Inhibition On Chronic Hypoxia-Induced Changes In Proximal And Distal Pulmonary Arterial Structure And Function, Rebecca R. Vanderpool, Ah Ram Kim, Robert C. Molthen, Naomi Chesler

Biomedical Engineering Faculty Research and Publications

Hypoxic pulmonary hypertension (HPH) is initially a disease of the small pulmonary arteries. Its severity is usually quantified by pulmonary vascular resistance (PVR). Acute Rho kinase inhibition has been found to reduce PVR toward control values in animal models, suggesting that persistent pulmonary vasoconstriction is the dominant mechanism for increased PVR. However, HPH may also cause proximal arterial changes, which are relevant to right ventricular (RV) afterload. RV afterload can be quantified by pulmonary vascular impedance, which is obtained via spectral analysis of pulsatile pressure-flow relationships. To determine the effects of HPH independent of persistent pulmonary vasoconstriction in proximal and …


Multimodality Imaging Of Abnormal Vascular Perfusion And Morphology In Preclinical 9l Gliosarcoma Model, Moses M. Darpolor, Robert C. Molthen, Kathleen M. Schmainda Jan 2011

Multimodality Imaging Of Abnormal Vascular Perfusion And Morphology In Preclinical 9l Gliosarcoma Model, Moses M. Darpolor, Robert C. Molthen, Kathleen M. Schmainda

Biomedical Engineering Faculty Research and Publications

This study demonstrates that a dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) perfusion parameter may indicate vascular abnormality in a brain tumor model and reflects an effect of dexamethasone treatment. In addition, X-ray computed tomography (CT) measurements of vascular tortuosity and tissue markers of vascular morphology were performed to investigate the underpinnings of tumor response to dexamethasone.


Effects Of Wrist Tendon Vibration On Targeted Upper-Arm Movements In Poststroke Hemiparesis, Megan O. Conrad, Robert A. Scheidt, Brian D. Schmit Jan 2011

Effects Of Wrist Tendon Vibration On Targeted Upper-Arm Movements In Poststroke Hemiparesis, Megan O. Conrad, Robert A. Scheidt, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Background. Impaired motor control of the upper extremity after stroke may be related to lost sensory, motor, and integrative functions of the brain. Artificial activation of sensory afferents might improve control of movement by adding excitatory drive to sensorimotor control structures. The authors evaluated the effect of wrist tendon vibration (TV) on paretic upper-arm stability during point-to-point planar movements. Methods. TV (70 Hz) was applied to the forearm wrist musculature of 10 hemiparetic stroke patients as they made center-out planar arm movements. End-point stability, muscle activity, and grip pressure were compared as patients stabilized at the target position …


Reorganization Of Finger Coordination Patterns During Adaptation To Rotation And Scaling Of A Newly Learned Sensorimotor Transformation, Xiaolin Liu, Kristine M. Mosier, Ferdinando A. Mussa-Ivaldi, Maura Casadio, Robert A. Scheidt Jan 2011

Reorganization Of Finger Coordination Patterns During Adaptation To Rotation And Scaling Of A Newly Learned Sensorimotor Transformation, Xiaolin Liu, Kristine M. Mosier, Ferdinando A. Mussa-Ivaldi, Maura Casadio, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

We examined how people organize redundant kinematic control variables (finger joint configurations) while learning to make goal-directed movements of a virtual object (a cursor) within a low-dimensional task space (a computer screen). Subjects participated in three experiments performed on separate days. Learning progressed rapidly on day 1, resulting in reduced target capture error and increased cursor trajectory linearity. On days 2 and 3, one group of subjects adapted to a rotation of the nominal map, imposed either stepwise or randomly over trials. Another group experienced a scaling distortion. We report two findings. First, adaptation rates and memory-dependent motor command updating …


A Database For Estimating Scanner-Specific Ct Dose, Taly Gilat-Schmidt Jan 2011

A Database For Estimating Scanner-Specific Ct Dose, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose: To develop a database for estimating scanner-specific organ dose in a voxelized patient model for any spectral shape and angular tube current modulation setting. The database enables the estimation of organ dose for both existing and novel acquisition techniques without requiring Monte Carlo simulations.

Methods: The transport of monoenergetic photons through three phantoms was simulated with the PENELOPE Monte Carlo radiation transport routines at 5 – 150 keV in 1 keV increments at 1000 projections in 0.36 degree increments. The source-to-detector distance for each simulation was 100 cm, with a source-to-isocenter distance of 50 cm. The lateral and axial …


Quantifying Mitochondrial And Plasma Membrane Potentials In Intact Pulmonary Arterial Endothelial Cells Based On Extracellular Disposition Of Rhodamine Dyes, Zhuohui Gan, Said H. Audi, Robert D. Bongard, Kathryn M. Gauthier, Marilyn P. Merker Jan 2011

Quantifying Mitochondrial And Plasma Membrane Potentials In Intact Pulmonary Arterial Endothelial Cells Based On Extracellular Disposition Of Rhodamine Dyes, Zhuohui Gan, Said H. Audi, Robert D. Bongard, Kathryn M. Gauthier, Marilyn P. Merker

Biomedical Engineering Faculty Research and Publications

Our goal was to quantify mitochondrial and plasma potential (Δψm and Δψp) based on the disposition of rhodamine 123 (R123) or tetramethylrhodamine ethyl ester (TMRE) in the medium surrounding pulmonary endothelial cells. Dyes were added to the medium, and their concentrations in extracellular medium ([Re]) were measured over time. R123 [Re] fell from 10 nM to 6.6 ± 0.1 (SE) nM over 120 min. TMRE [Re] fell from 20 nM to a steady state of 4.9 ± 0.4 nM after ∼30 min. Protonophore or high K+ concentration ([K+]), …


Exploring The Potential Of Inkjet Printing For The Fabrication Of Tissue Test Systems, Vidya Seshadri Jan 2011

Exploring The Potential Of Inkjet Printing For The Fabrication Of Tissue Test Systems, Vidya Seshadri

All Theses

Animal models and two-dimensional assays involved in drug testing, vaccine development and basic scientific discovery are not an accurate representation of the human body; hence there is a need to develop new bench top methodologies which are better suited to yield information about in vivo behavior. There is a paucity of reliable in vitro-derived information regarding the reasons for the cause and progression of diseases. These concerns have lead to the development of three-dimensional systems which can facilitate improved understanding of disease etiology and also can bridge the path to the clinic.
The long term goal, beyond the scope of …


A Microfluidic Device For Impedance Spectroscopy, Ahmet Can Sabuncu Jan 2011

A Microfluidic Device For Impedance Spectroscopy, Ahmet Can Sabuncu

Mechanical & Aerospace Engineering Theses & Dissertations

Recently, microfluidics has become a versatile tool to investigate cellular biology and to build novel biomedical devices. Dielectric spectroscopy, on the other hand, allows non-invasive probing of biological cells. Information on the cell membrane, cytoplasm, and nucleus can be obtained by dielectric spectroscopy provided that appropriate tools are used in specific frequency ranges. This dissertation includes fabrication, characterization, and testing of a simple microfluidic device to measure cell dielectric properties. The dielectric measurements are performed on human T-cell leukemia (Jurkat), mouse melanoma (B16), mouse hepatoma (Hepa), and human costal chondrocyte cells. Dielectric measurements consist of measuring the complex impedance of …


The Feasibility Of Using Bifidobacteria Bifidum (Atcc 700541) For The Production Of Prebiotic Oligosaccharides, Candice Marie Luehrs Jan 2011

The Feasibility Of Using Bifidobacteria Bifidum (Atcc 700541) For The Production Of Prebiotic Oligosaccharides, Candice Marie Luehrs

Masters Theses

"Galactooligosaccharides (GOS) are prebiotics that are being used to influence intestinal microbiota towards health promoting, beneficial bacteria like bifidobacteria. Natural sources of GOS are not found in suitable levels to achieve the desired health effects so economically viable commercial production methods are important. Enzymatic conversion of lactose to GOS through transgalactosylation is a preferred method since the starting material is inexpensive and readily available. Enzymes used in batch production are purified from fungal or bacterial sources or remain in whole cells cultured for GOS production. Purified or unbound enzymes are single use whereas enzymes retained within whole cells can potentially …


Analysis Of The Performance Of Peanut Fame In A Single Cylinder Idi Engine And Investigations Of Neat Methyl Ester Influence On Fuel Quality, Jeffery Lewis Jan 2011

Analysis Of The Performance Of Peanut Fame In A Single Cylinder Idi Engine And Investigations Of Neat Methyl Ester Influence On Fuel Quality, Jeffery Lewis

College of Graduate Studies: Theses & Dissertations

Author's abstract: To meet evolving standards set forth by the U.S. EPA and U.S. Energy Policy it is necessary to consider a variety of feedstock for biofuels synthesis and to understand the role individual fatty acids contribute to the overall performance. It is the belief of the authors that excess peanut production would provide an excellent source for high quality biodiesel feedstock, and the complete property and combustion analysis of the fatty acid components will provide insight for future biofuel developments. The preliminary investigations of the project focused on the combustion performance and thermal efficiency of peanut FAME and its …


Locating And Extracting Acoustic And Neural Signals, Na Zhu Jan 2011

Locating And Extracting Acoustic And Neural Signals, Na Zhu

Wayne State University Dissertations

This dissertation presents innovate methodologies for locating, extracting, and separating multiple incoherent sound sources in three-dimensional (3D) space; and applications of the time reversal (TR) algorithm to pinpoint the hyper active neural activities inside the brain auditory structure that are correlated to the tinnitus pathology. Specifically, an acoustic modeling based method is developed for locating arbitrary and incoherent sound sources in 3D space in real time by using a minimal number of microphones, and the Point Source Separation (PSS) method is developed for extracting target signals from directly measured mixed signals. Combining these two approaches leads to a novel technology …


Issues On Clean Diesel Combustion Technology Using Supercritical Fluids: Thermophysical Properties And Thermal Stability Of Diesel Fuel, Ronghong Lin Jan 2011

Issues On Clean Diesel Combustion Technology Using Supercritical Fluids: Thermophysical Properties And Thermal Stability Of Diesel Fuel, Ronghong Lin

Biomedical and Chemical Engineering - Dissertations

The clean diesel combustion technology using supercritical fluids is aimed to both improve fuel economy and reduce harmful emissions. This novel process involves preparation, injection and combustion of supercritical fuel/diluents mixtures. Design and development of this new process require a deep understanding of fuel properties. The current study has attempted to address three fuel property related issues: fuel surrogates, diffusivity and thermal stability.

Fuel surrogates are often used in engine research to mimic real fuel properties. In this work, ten diesel fuel surrogates were investigated, and the ability of these surrogates to predict diesel fuel properties was evaluated. It was …


Evaluation Of A Stream‐Aquifer Analysis Test For Deriving Reach‐Scale Streambed Conductance, Garey A. Fox, Derek M. Heeren, Michael A. Kizer Jan 2011

Evaluation Of A Stream‐Aquifer Analysis Test For Deriving Reach‐Scale Streambed Conductance, Garey A. Fox, Derek M. Heeren, Michael A. Kizer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Extracting groundwater from pumping wells located adjacent to streams can reduce streamflow, a result that is known as alluvial well depletion. Numerous analytical solutions have been developed for alluvial well depletion that vary in their mathematical complexity. Predicted drawdown by the analytical solutions can be matched to observed drawdown from a stream–aquifer analysis (SAA) test (i.e., a pumping test adjacent to a stream) to simultaneously estimate aquifer and streambed hydrologic parameters. However, only a few SAA tests have been documented in the literature and compared to field–measured streambed parameters. Therefore, the objective of this research was to perform an SAA …


Correlation Between Alternans Of Early And Late Phases Of Ventricular Action Potential, Sonam Chourasia Jan 2011

Correlation Between Alternans Of Early And Late Phases Of Ventricular Action Potential, Sonam Chourasia

Theses and Dissertations--Biomedical Engineering

Several studies suggest that action potential duration (APD) alternans play an important role in initiation of arrhythmias, while less is known about the alternans of early phases of action potential (AP) and phase relation between the two. Transmembrane potentials recorded from swine and canine ventricles were analyzed to determine the correlation and phase relation between alternans of early and late phases of an AP. In both species, for activation intervals ≤ 400 ms, action potential amplitude (APA) alternans occurred≥ 50% of times when APD alternans occurred and vice versa, both were mostly in phase. Also, alternans of APA and APD …


Direct Forcing And Heating Immersed Boundary- Lattice Boltzmann Method For Arterial Wall Thermography, Oluyinka Olugbenga Bamiro Jan 2011

Direct Forcing And Heating Immersed Boundary- Lattice Boltzmann Method For Arterial Wall Thermography, Oluyinka Olugbenga Bamiro

Dissertations

Vulnerable atherosclerotic plaques have high probability of rupture and are characterized by non-homogenous temperature along the arterial wall. The nonhomogeneous temperature is attributed to the accumulation of heat releasing inflammatory cells in the arterial wall. Rupture of the vulnerable plaque can lead to acute coronary syndrome and sudden cardiac death. Arterial wall thermography (AWT) can be applied to detect the presence of temperature hot spots along the arterial wall by using temperature measurement devices and provide an early detection of a vulnerable atherosclerotic plaque. AWT, however, is invasive in nature.

Computational fluid and heat transport models provide a more efficient …