Digital Commons Network^™

Ultrasound Elasticity Measurements As A Predictor For Arteriovenous Fistula Maturation, Anna Sorace

All ETDs from UAB

This research thesis examines the applicability of using ultrasound imaging to quantify arterial elasticity and assess potential of arteriovenous fistula maturation in chronic kidney disease (CKD) patients. Tissue-specific abnormalities have proven useful for identifying disease states within oncology, cardiovascular and musculoskeletal system. Using ultrasound-based imaging to evaluate arterial elasticity is a noninvasive and novel technique. It has the potential to contribute further insight into chronic kidney disease fistula failure and become a noninvasive prognostic indicator. Reliable vascular access is critical for delivery of adequate hemodialysis treatment to CKD patients and to maintain long-term connections for dialysis. An arteriovenous fistula is …

Low Noise And Low Repetition Rate Semiconductor-Based Mode-Locked Lasers, Dimitrios Mandridis

Electronic Theses and Dissertations

The topic of this dissertation is the development of low repetition rate and low noise semiconductor-based laser sources with a focus on linearly chirped pulse laser sources. In the past decade chirped optical pulses have found a plethora of applications such as photonic analogto-digital conversion, optical coherence tomography, laser ranging, etc. This dissertation analyzes the aforementioned applications of linearly chirped pulses and their technical requirements, as well as the performance of previously demonstrated chirped pulse laser sources. Moreover, the focus is shifted to a specific application of the linearly chirped pulses, timestretched photonic analog-to-digital conversion (TS ADC). The challenges of …

Estimation Of Dariy Particulate Matter Emission Rates By Lidar And Inverse Modeling, C. C. Marchant, Kori D. Moore, Michael D. Wojcik, Randy S. Martin, R L. Pfeiffer, K H. Prueger, J L. Hatfield

Civil and Environmental Engineering Faculty Publications

Particulate matter (PM) emissions from agricultural operations are an important issue for air quality and human health and a topic of interest to government regulators. PM emission rates from a dairy in the San Joaquin Valley of California were investigated during June 2008. The facility had 1,885 total animals, including 950 milking cows housed in free-stall pens with an open-lot exercise area, and 935 dry cows, steers, bulls, and heifers housed in open lots. Point sensors, including filter-based aerodynamic mass samplers and optical particle counters (OPC), were deployed at select points around the facility to measure optical and aerodynamic particulate …

Development Of A Technique For Achieving An Optimum Bsfc For Laf Engine, Shreyash S. Ukidave

Dissertations, Master's Theses and Master's Reports - Open

The reserves of gasoline and diesel fuels are ever decreasing, which plays an important role in the technological development of automobiles. Numerous countries, especially the United States, wish to slowly decrease their fuel dependence on other countries by producing in house renewable fuels like biodiesels or ethanol. Therefore, the new automobile engines have to successfully run on a variety of fuels without significant changes to their designs. The current study focuses on assessing the potential of ethanol fuels to improve the performance of 'flex-fuel SI engines,' which literally means 'engines that are flexible in their fuel requirement.'

Another important area …

Local Degradation Of Structural, Mechanical, Electrical And Chemical Properties Of Membrane Electrode Assembly In Polymer Electrolyte Fuel Cell, Nishith Parikh

Dissertations, Master's Theses and Master's Reports - Open

Polymer electrolyte fuel cell (PEMFC) is promising source of clean power in many applications ranging from portable electronics to automotive and land-based power generation. However, widespread commercialization of PEMFC is primarily challenged by degradation. The mechanisms of fuel cell degradation are not well understood. Even though the numbers of installed units around the world continue to increase and dominate the pre-markets, the present lifetime requirements for fuel cells cannot be guarantee, creating the need for a more comprehensive knowledge of material’s ageing mechanism. The objective of this project is to conduct experiments on membrane electrode assembly (MEA) components of PEMFC …

Nanofluid Optical Property Characterization: Towards Efficient Direct Absorption Solar Collectors, R. A. Taylor, P. E. Phelan, Todd Otanicar, R. Adrian, R. Prasher

Mechanical Engineering Faculty Works

Suspensions of nanoparticles (i.e., particles with diameters < 100 nm) in liquids, termed nanofluids, show remarkable thermal and optical property changes from the base liquid at low particle loadings. Recent studies also indicate that selected nanofluids may improve the efficiency of direct absorption solar thermal collectors. To determine the effectiveness of nanofluids in solar applications, their ability to convert light energy to thermal energy must be known. That is, their absorption of the solar spectrum must be established. Accordingly, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (0.25 to 2.5 mu m). A simple addition of the base fluid and nanoparticle extinction coefficients is applied as an approximation of the effective nanofluid extinction coefficient. Comparisons with measured extinction coefficients reveal that the approximation works well with water-based nanofluids containing graphite nanoparticles but less well with metallic nanoparticles and/or oil-based fluids. For the materials used in this study, over 95% of incoming sunlight can be absorbed (in a nanofluid thickness >= 10 cm) with extremely low nanoparticle volume fractions - less than 1 x 10(-5), or 10 parts per million. Thus, nanofluids could be used to absorb sunlight with a negligible amount of viscosity and/or density (read: pumping power) increase.

Design And Implementation Of A Voice-Controlled Prosthetic Hand, Musa Hakan Asyali, Mustafa Yilmaz, Mahmut Tokmakçi, Kanber Sedef, Beki̇r Hakan Aksebzeci̇, Rohin Mittal

Turkish Journal of Electrical Engineering and Computer Sciences

Current hand prostheses are mostly driven by electromyography (EMG) signal, and existing experiments have proved that multichannel EMG signal controls are not suitable due to early fatigue problems and high effort requirements to perform even simple activities. Therefore, in this study we present a new voice-controlled active hand prosthesis to perform several basic tasks. We first designed a novel multifingered prosthetic hand with the ability of picking up and releasing objects. The prosthetic hand employs 3 DC motors and gears to transfer motion to the linked iparts of the fingers. We used flexible thin-film resistive force sensors at the fingertips …

Stray Magnetic Field Distributed Around A Pmsm, Ali̇ Ahmed Adam, Kayhan Gülez, Seli̇m Köroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, the low frequency electromagnetic emission from permanent magnet synchronous motors is studied. The main objective is to provide a safety region for humans in the vicinity of these motors, especially as these motors are now being used widely in inhabited areas, where high flux densities are expected. In this study, a new proposed equivalent magnetic circuit is used to estimate the stray fields at the surface of the motor. The analysis showed that the emission of the stray field in the radial direction depends on the permeability of the stator body. Low values of permeability may result …

Imitation Of Basic Hand Preshapes By Fluid Based Method: Fluidics Formation Control, Umut Ti̇lki̇, İsmet Erkmen, Aydan Müşerref Erkmen

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new approach is developed, avoiding the correspondence problem caused by the difference in embodiment between imitator and demonstrator in imitation learning. In our work, the imitator is a fluidic system of dynamics totally different than the imitatee, which is a human performing hand gestures. The fluidic system is composed of fluid particles, which are used for the discretization of the problem domain. In this work, we demonstrate the fluidics formation control so as to imitate by observation basic hand preshaping features. Our fluidic formation control is based on setting suitable parameters of Smoothed Particle Hydrodynamics (SPH), …

Stability Of Affinity Based Layer-By-Layer Polymeric Self-Assemblies For Oral Wound Applications, Sundar Prasanth Authimoolam

Theses and Dissertations--Chemical and Materials Engineering

Oral mucositis is a painful and debilitating chronic inflammatory condition that can result from chemo and/or radiotherapy. While current treatment strategies which provide temporary relief exist, there is still an unmet clinical need for a robust long active barrier strategy which can simultaneously provide protection and release drug to enhance the wound healing response. It is proposed that an affinity based layer-by-layer self-assembled barrier administered as a series of mouth rinses can allow for wound specific drug delivery, providing an effective regenerative therapy.

In this work, biotinylated poly(acrylic acid) is used to develop LBL assemblies based upon biotin-streptavidin affinity interactions. …

Quantitative Carré Differential Interference Contrast Microscopy To Assess Phase And Amplitude, Donald D. Duncan, David G. Fischer, Amanda Dayton, Scott A. Prahl

Electrical and Computer Engineering Faculty Publications and Presentations

We present a method of using an unmodified differential interference contrast microscope to acquire quantitative information on scatter and absorption of thin tissue samples. A simple calibration process is discussed that uses a standard optical wedge. Subsequently, we present a phase-stepping procedure for acquiring phase gradient information exclusive of absorption effects. The procedure results in two-dimensional maps of the local angular (polar and azimuthal) ray deviation. We demonstrate the calibration process, discuss details of the phase-stepping algorithm, and present representative results for a porcine skin sample.

The Effects Of Anti-Price Gouging Legislation On Supply Chain Dynamics, Jason Edward Maynard

Master's Theses

The purpose of this thesis is to model the effects of anti-price gouging (APG) legislation on the costs to businesses during the recovery period of a disaster. A system dynamics model of a business’s replenishment procedures is used to simulate the effects of APG legislation on business performance. Economists have published expansive research on the effects of price ceilings on supply and demand, but there is little research evidence on the operational consequences of price ceiling legislation on business costs. APG legislation increases consumer’s forward buying and shortage gaming after a disaster by removing price incentives to be frugal. Forward …

Evaluation Of The Optical And Mechanical Properties Of Cad-Cam Generated Yttria-Stabilized Zirconia Laminate Veneers, Tariq F. Alghazzawi

All ETDs from UAB

The purpose of this investigation was to study three aspects which have been shown to limit clinical applications of yttria-stabilized zirconia (Y-TZP) for dental restorations. Mechanical property and structural changes due to low-temperature degradation (LTD) of Y-TZP led to increased surface roughness and monoclinic phase fractions, with a concomitant decrease in hardness and modulus. Yttria content and flexural strength were unchanged and phase transformation proceeded from the surface into the bulk of the material. The optical properties of Y-TZP, IPS e.max® CAD (IEC), and feldspathic por-celain (FP) laminate veneers showed that the underlying color of try-in pastes (TP) af-fected the …

Fabrication Of Biodegradable Fibers Using Hdpe/Starch Blends. Morphological, Mechanical And Processing, Fayaz J. Ali

All ETDs from UAB

Products developed from polymeric materials have found a myriad of applications that make life better and more convenient. In many cases, however, plastics end up in landfills after their useful lifetime. The inability of most synthetic plastics to degrade in the landfill presents a challenge to continue to expand their applications in order to minimize their environmental impact. Incorporating natural fibers into synthetic polymers has been investigated recently; however, most of the natural fibers do not have the mechanical properties of their inorganic counterparts. Thus, there is a need for high strength fibers that are degradable. The goal of this …

Biometic Self-Assembled Nanomatrix For Bone Tissue Regeneration, Joel Matthew Anderson

All ETDs from UAB

Formation of the native bone extracellular matrix (ECM) provides an attractive template for bone tissue engineering. At the cellular level, structural support and biological complexity of bone ECM are provided within a composite microenvironment that consists of an organic fibrous network reinforced by inorganic hydroxyapatite (HA) nanostructured crystals. To synthetically recreate this biphasic assembly, a bone ECM analogous scaffold comprised of self-assembling peptide amphiphile (PA) nanofibers and interspersed HA nanoparticles was investigated. The PAs have been endowed with biomolecular ligand signaling using synthetically inscribed peptide sequences (i.e. RGDS, DGEA) derived from the native bone ECM and integrated with HA nanoparticles …

Functional Imaging Of Excitable Cells: Retinal Neurons And Pancreatic Islet Beta Cells, Yichao Li

All ETDs from UAB

Stimulus-evoked fast intrinsic optical signals (IOSs) have time courses comparable to electrophysiological kinetics, and thus promise a sub-cellular and sub-second resolution method for functional evaluation of excitable biological tissues. The objective of my thesis research is to validate and characterize IOS imaging of stimulus-evoked activities in the retina and pancreatic islet ß-cells. In order to achieve this objective, three sets of experiments have been conducted. 1) Simultaneous measurement of retinal neurons functioning can enhance our understanding of the visual signal processing. In this stage of my study, I propose to demonstrate IOS imaging of retina slices that allows simultaneous monitoring …

Delayed-Bang Approach Towards More Sustainable Critical Infrastructure Risk Management, C. Ariel Pinto, Michael K. Mcshane, Abhishek S. Pathak

Finance Faculty Publications

This article describes the Delayed Bang Approach for determining the value of risk management alternatives in critical infrastructure security. The discussion includes (1) the need for sustainable risk management (2) the importance of time valuation in evaluating competing loss prevention and loss reduction alternatives, (3) the convergence of deterministic engineering economics, survivability analysis, and probabilistic analysis, and (4) hypothetical examples of the Delayed-Bang Approach and significance towards more sustainable risk management.

Energy Deposition In The Breast During Ct Scanning: Quantification And Implications For Dose Reduction, Franco Rupcich, Iacovos Kyprianou, Andreu Badal, Taly Gilat Schmidt

Biomedical Engineering Faculty Research and Publications

Studies suggest that dose to the breast leads to a higher lifetime attributable cancer incidence risk from a chest CT scan for women compared to men. Numerous methods have been proposed for reducing dose to the breast during CT scanning, including bismuth shielding, tube current modulation, partial-angular scanning, and reduced kVp. These methods differ in how they alter the spectrum and fluence across projection angle. This study used Monte Carlo CT simulations of a voxelized female phantom to investigate the energy (dose) deposition in the breast as a function of both photon energy and projection angle. The resulting dose deposition …

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 …

Visual And Proprioceptive Contributions To Compensatory And Pursuit Tracking Movements In Humans, Megan L. Heenan, Robert A. Scheidt, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

An ongoing debate in the field of motor control considers how the brain uses sensory information to guide the formation of motor commands to regulate movement accuracy. Recent research has shown that the brain may use visual and proprioceptive information differently for stabilization of limb posture (compensatory movements) and for controlling goal-directed limb trajectory (pursuit movements). Using a series of five experiments and linear systems identification techniques, we modeled and estimated the sensorimotor control parameters that characterize the human motor response to kinematic performance errors during continuous compensatory and pursuit tracking tasks. Our findings further support the idea that pursuit …

A Quantitative And Standardized Robotic Method For The Evaluation Of Arm Proprioception After Stroke, Lucia Simo, Claude Ghez, Lior Botzer, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Stroke often results in both motor and sensory deficits, which may interact in the manifested functional impairment. Proprioception is known to play important roles in the planning and control of limb posture and movement; however, the impact of proprioceptive deficits on motor function has been difficult to elucidate due in part to the qualitative nature of available clinical tests. We present a quantitative and standardized method for evaluating proprioception in tasks directly relevant to those used to assess motor function. Using a robotic manipulandum that exerted controlled displacements of the hand, stroke participants were evaluated, and compared with a control …

2d Gaussian Object Motion Detection, Miguel Angel Chaidez

Open Access Theses & Dissertations

Dr. John Moya, and associated research assistants, have previously created an image-change recognition algorithm (JESSE) to mark changes within an image. The focus of this thesis is to present a physical application and modification of this algorithm in order to detect a surgeon's hand and verify chip placement on a printed circuit board.

There are different techniques in implementing visual recognition and motion detection with smart systems but the high cost and complicated calibration of these systems make them impractical. The goal was to create a system that is simple, inexpensive and applicable to multiple applications that will allow the …

Development Of A New Evolutionary Algorithm Based On Adaptive Echolocation Applied To A Multi Objective Version Of The Redundancy Allocation Problem, Karla Rocio Gutierrez

Open Access Theses & Dissertations

The intention of this research is to develop a new algorithm that it is mainly focus in the principle of echolocation or also called biosonar. This principle is active in many animals such as: birds, shrews, dolphins and bats, these last ones are going to be a fundamental part of our study. These animals use it as radar in order to find food, obstacles or just to locate objects.

These animals use ultrasound beams with a certain degree of angle and multiple receivers; such as the two ears that are located slightly apart, so at the time of the returning …

Solving The Partial Differential Equation Of Vibrations With Interval Parameters Using The Interval Finite Difference Method, Brenda G. Medina

Open Access Theses & Dissertations

Accuracy and efficiency are among the main factors that drive today's innovative disciplines. As technology rapidly advances, efficiency takes on new meanings but what about accuracy? How accurate is accurate? Human error, uncertainties in measurement, and rounding errors are just some causes of inaccuracy. Interval Computations is an area that allows for such issues to be taken into account; for each measurement attained (for example), an interval can be built by considering the error associated with the measurement, and such an interval can be utilized in the mathematical computations of interest.

We consider the partial differential equation (PDE) of vibrations …

Analysis Of Indoor And Outdoor Particulate Matter At Various Residences In The El Paso Region, Joseph Christopher Pinon

Open Access Theses & Dissertations

This thesis is a presentation of particulate matter data collected from February 2007 to June 2008. Personal environment monitors (PEM), which measured 7-day PM2.5 concentrations, had been deployed at 14 homes during the 2007 year and deployed in 16 different homes during the 2008 sampling year. Within each sampling year, sampling occurred for two one-week (7-day) periods during each season. In addition to PEM sampling, a tapered element oscillating microbalance (TEOM) continuous sampler had been deployed in both indoors and outdoors at one pre-selected household per week. Gravimetric, chemical, and black carbon analysis had been performed on the PEM PM2.5 …

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 …

Novel Photovoltaic Device For Targeted Drug Delivery, Sunny S. Ambure

Open Access Theses & Dissertations

Despite decades of research, progress in targeted drug delivery is relatively slow, hampered, in part, by the lack of appropriate mechanisms to deliver anticancer drugs selectively to tumor tissues. Systemic or oral administration can cause severe toxicity, which limits the therapeutic potential of anticancer drugs [1]. Therefore, the most important goal of drug delivery is to minimize the exposure of normal tissues to these drugs while maintaining their therapeutic concentration in tumors.

A photovoltaic cell (PV) is a system that converts lights into electricity as well as induces charge transfer by photovoltaic effect. Motivated by such unique property, we have …

Analysis Of Endocrine Disrupting Compounds In Wastewater Treatment Plants: A Perspective Of Trans-Boundary Waterborne Pollution, Roberto De La Torre

Open Access Theses & Dissertations

Recent decades have brought an increasing concern of potential adverse human and ecological health effects resulting from Endocrine Disruptor Compounds (EDCs). In particular from new emerging compounds such as natural estrogens (e.g., 17©¬-estradiol, estrone), synthetic estrogens (e.g., 17Â¥á-ethynylestradiol), bisphenol A (BPA), nonylphenol ethoxylates (NPEOS), and nonylphenol (NP). These chemicals which are also known as organic wastewater contaminants are released directly to the environment after passing through wastewater treatment plants (WWTPs), which often are not designed to remove them from the effluent. The occurrence of the aforementioned compounds in surface water is becoming of increasing concern worldwide, and has led to …

Mixed-Signal Distributed Feature Extraction For Classification Of Wide-Band Acoustic Signals On Sensor Networks, Humberto Santacruz

Open Access Theses & Dissertations

This thesis proposes a distributed/collaborative scheme for the classification of wide-band acoustic events within the context wireless sensor networks (WSNs). The proposed method is characterized by a mixed-signal processing scheme for the extraction of feature vectors which reduces the processing, memory allocation, and power requirements of the sensor nodes. The mixed-signal scheme assumes that nodes have an analog frontend consisting of a microphone, a bandpass filter, a squaring element and an integrator. This chain of components produces an estimate of the energy over the frequency subband extracted by the filter. The WSN has the ability to form a distributed filter …

An Evolutionary Approach Based On Viral Replication For Solving Combinatorial Optimization Problems, Claudia Evangelina Valles Sosa

Open Access Theses & Dissertations

A new multi-objective evolutionary algorithm that mimics the way viruses replicate is presented. The purpose of viral replication is to allow the reproduction and survival of its kind. The algorithm is able to produce a large number of solutions to be evaluated by imitating the way viral replication and the infection process work. The well-known multi-objective redundancy allocation problem is used to show the performance of this new viral-based evolutionary approach. The algorithm considers the maximization of system reliability, the minimization of system cost, and the minimization of system weight to be optimized simultaneously. The solution to the multi-objective optimization …