Engineering Commons^™

Characterization Of Internal Wake Generator At Low Reynolds Number With A Linear Cascade Of Low Pressure Turbine Blades, Chase A. Nessler

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Unsteady flow and its effects on the boundary layer of a low pressure turbine blade is complex in nature. The flow encountered in a low pressure turbine contains unstructured free-stream turbulence, as well as structured periodic perturbations caused by upstream vane row wake shedding. Researchers have shown that these conditions strongly influence turbine blade performance and boundary layer separation, especially at low Reynolds numbers. In order to simulate these realistic engine conditions and to study the effects of periodic unsteadiness, a moving bar wake generator has been designed and characterized for use in the Air Force Research Labs low speed …

Sulfur-Tolerant Catalyst For The Solid Oxide Fuel Cell, Bozeman Joe Frank Iii

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JP-8 fuel is easily accessible, transportable, and has hydrogen content essential to solid oxide fuel cell (SOFC) operation. However, this syngas has sulfur content which results in a poisonous hydrogen sulfide that degrades electrochemical activity and causes complete SOFC failure in some cases. The goal is to synthesize and verify a cost-effective, catalyst supported on cerium oxide that either stabilizes ionic conductivity in the presence of hydrogen sulfide and/or is highly sulfur-resistant. After thorough computational analysis, it was concluded that the platinum-copper skin catalyst was the most cost-effective, sulfur-resistant catalyst. Experimental synthesis of copper, platinum, and platinum-copper skin catalysts supported …

Radio Frequency Controlled Stimulation Of Intracellular Gold Or Silver Nanoparticle Conjugates For Use As Potential Sensors Or Modulators Of Biological Function, Richard Craig Murdock

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The objective of this investigation was to further explore the ability of a radio frequency (RF) signal to interact with metal nanoparticles (NPs) for the purposes of remote stimulation or control of cellular processes. Gold and silver NPs have shown the ability to be heated by electromagnetic frequencies, especially for the purpose of deactivating abnormal cells. However, the heating of the NPs in these previous studies was constant and uncontrolled. For this study, our hypothesis was by investigating the RF heating characteristics of NPs and its impact on surface functionalizations, a remotely stimulated control mechanism can be developed at the …

A Novel Synergistic Diagnosis Methodology For Identifying Abnormalities In Wireless Capsule Endoscopy Videos, Alexandros Karargyris

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Wireless Capsule Endoscopy (WCE) is a new technology that allows medical personnel to view the gastrointestinal (GI) mucosa. It is a swallowable miniature capsule device the size of a pill that transmits thousands of screenshots of the digestive tract to a wearable receiver. When the procedure finishes the video is uploaded to a workstation for viewing. Capsule Endoscopy has been established as a tool to identify various gastrointestinal (GI) conditions, such as blood-based abnormalities, polyps, ulcers, Crohn's disease in the small intestine, where the classical endoscopy is not regularly used.

As of 2009 the market is dominated by Given Imaging …

Design And Development Of A Wireless Data Acquisition System For Fall Detection, Anoop Hanchinamane Ramakrishna

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With the mortality rate of the elderly on the rise due to fall related incidents, fall detection has become an important entity in the geriatric health care sector. The study conducted in this thesis involved the design and development of a Wireless Data Acquisition System (WDAS) with Bluetooth capabilities interfaced to pulse width modulated gyroscopic sensors. Each sensor used has a reference output pulse width which changes when rotated about its sensitive axis.Part of the effort involves the design and development of two versions of printed circuit boards for the application. Each board includes a Parallax Propeller micro- controller in …

Uncertainty Quantification Of Residual Stresses Induced By Laser Peening Simulation, Hemanth Amarchinta

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Advanced mechanical surface enhancement techniques have been used successfully to increase the fatigue life of metallic components. These techniques impart deep compressive residual stresses into the component to counter potentially damage-inducing tensile stresses generated under service loading. Laser Peening (LP) is an advanced mechanical surface enhancement technique used predominantly in the aircraft industry. To reduce costs and make the technique available on a large-scale basis for industrial applications, simulation of the LP process is required. Accurate simulation of the LP process is a challenging task, because the process has many parameters such as laser spot size, pressure profile, and material …

Hard-Switching And Soft-Switching Two-Switch Flyback Pwm Dc-Dc Converters And Winding Loss Due To Harmonics In High-Frequency Transformers, Dakshina S. Murthy Bellur

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The flyback pulse-width modulated (PWM) DC-DC power converter is a very important circuit in switching mode power supply (SMPS) converters for low power applications. The main drawback of the conventional single-switch flyback converter is the high turn-off voltage stress suffered by the switch. The high voltage transients are caused by the resonant behavior of the transformer leakage inductance and the transistor output capacitance, resulting in ringing superimposed on the steady-state switch voltage level. This requires a transistor with higher voltage rating. However, a transistor with higher voltage rating has higher on-resistance causing higher conduction loss. The high voltage ringing also …

High-Power Energy Scavenging For Portable Devices, Simon J. Tritschler

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Portable electronic devices and crafts such as unmanned aerial vehicles (UAV's) may benefit greatly from the ability to extract power from overhead distribution power lines on a temporary basis to power electronics or charge on-board batteries. However, most of the current literature on the subject of energy scavenging is focused on micropower and other small-scale applications. Several high-power energy scavenging methods are investigated here with an emphasis on relating physical sensor dimensions with output power. A novel power scavenging mechanism is introduced that shows excellent correlation between theoretical and experimental performance. In addition, a universal power supply is proposed which …

Algorithmic Techniques Employed In The Quantification And Characterization Of Nuclear Magnetic Resonance Spectroscopic Data, Paul Edward Anderson

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Nuclear magnetic resonance (NMR) based metabolomics is a developing research field with broad applicability, including the identification of biomarkers associated with pathophysiologic changes, sample classification based on the mechanism of toxicity, and clinical diagnosis. Intrinsic to these applications is the need for statistical and computational techniques to facilitate the associated data analysis. Further, a typical 1H NMR spectrum of pure proteins, biofluids, or tissue may contain thousands of resonances (i.e., peaks), thus, a pure visual inspection is insufficient to fully utilize the spectral information.

Common practice within the NMR-based metabolomics community is to evaluate and validate novel algorithms on empirical …

Semantic Provenance: Modeling, Querying, And Application In Scientific Discovery, Satya Sanket Sahoo

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Provenance metadata, describing the history or lineage of an entity, is essential for ensuring data quality, correctness of process execution, and computing trust values. Traditionally, provenance management issues have been dealt with in the context of workflow or relational database systems. However, existing provenance systems are inadequate to address the requirements of an emerging set of applications in the new eScience or Cyberinfrastructure paradigm and the Semantic Web. Provenance in these applications incorporates complex domain semantics on a large scale with a variety of uses, including accurate interpretation by software agents, trustworthy data integration, reproducibility, attribution for commercial or legal …

B S News January/February

Building Services Engineering

No abstract provided.

Development Of An Unsteady Aeroelastic Solver For The Analysis Of Modern Turbomachinery Designs, Timothy James Leger

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Developers of aircraft gas turbine engines continually strive for greater efficiency and higher thrust-to-weight ratio designs. To meet these goals, advanced designs generally feature thin, low aspect airfoils, which offer increased performance but are highly susceptible to flow-induced vibrations. As a result, High Cycle Fatigue (HCF) has become a universal problem throughout the gas turbine industry and unsteady aeroelastic computational models are needed to predict and prevent these problems in modern turbomachinery designs. This research presents the development of a 3D unsteady aeroelastic solver for turbomachinery applications. To accomplish this, a well established turbomachinery Computational Fluid Dynamics (CFD) code called …

Fusion Of Video And Doppler Radar For Traffic Surveillance, Arunesh Roy

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Current Continuous Wave (CW) Doppler radar speed measurement systems lack the ability to distinguish multiple targets. Most systems can only identify the strongest (closest) target or the fastest target.

This dissertation is related to a fusion algorithm for a VIdeo-Doppler-radAR (Vidar) traffic surveillance system. The Vidar systems uses a robust matching algorithm which iteratively matches the information from a video camera and multiple Doppler radars corresponding to the same moving vehicle, and a stochastic algorithm which fuses the matched information from the video camera and Doppler radars to derive the vehicle velocity and angle information.

We use two heterogeneous sensors …

Fault Diagnosis Of Vehicular Electric Power Generation And Storage, Hithesh Sanjiva Uliyar

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Automotive vehicles are becoming increasingly dependent on electric power, and this trend will accelerate. The health of the vehicular electric power generation and storage (EPGS) system is crucial to enhance vehicle safety, fuel economy, and customer satisfaction.

In this research, a state-of-health (SOH) monitoring method is developed for automotive EPGS system, focusing on alternator related faults. Parity relations, characterizing the correlation among EPGS system signals under normal operating conditions, are generated using principal/minor component analysis techniques. Based on a design of structured residuals, the faults under consideration, including shorted diodes, belt slippage, and regulator fault, are successfully detected and isolated. …

Characterization And Improvement Of A Cone-Beam Ct Scanner For Quantitative Imaging, Jimish Dilip Joshi

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Computed tomography (CT) has various applications in different fields. In our case, the cone-beam CT scanner is used in the industrial field for qualitative and quantitative assessment of Procter and Gamble products. The Flash CT scanner, on which we do our research, has a microfocus x-ray tube, a detector size of 30 cm x 40 cm and a rotating stage for the object to be imaged. The x-ray tube can be operated up to 225 kV. Non-linearities in the response of the detector, scatter and beam hardening may cause false interpretations of the image values. To allow appropriate assessment of …

Domain-Specific Core Self-Evaluations And Stressors As Predictors Of Strains, Michael Raymond Hoepf

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The current study examines the use of a frame-of-reference (FOR) in the evaluation of core self-evaluations, stressors and strains. The study investigates the prediction that using a FOR that matches predictors and outcomes will result in a stronger relationship between the constructs being measured, specifically CSE, stressors, and strains. In addition, the study examines the extent to which following this procedure will add incremental validity after non-contextualized predictors are controlled. The hypotheses in this study were generally supported, although the hypotheses related to the school domain were not supported as strongly as those related to general and work domain. The …

Structural Health Monitoring Of A Thermal Protection System For Fastener Failure With A Validated Model, Randy Joseph Tobe

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Air vehicles flying at hypersonic speeds encounter extreme thermal, aerodynamic and acoustic loads. To maintain the structural integrity of the flight vehicle, a thermal protection system shields the main structure from these loads. Therefore, maintaining the health of the thermal protection system is critical for a successful mission and vehicle safety. One of the more common types of failure in a mechanically attached thermal protection system is fastener failure. Since reducing vehicle turnaround between flights is desired, creating an automated system to perform structural health monitoring on the fastener health of the thermal protection system is needed. This can be …

Design Of Ultra High Speed Flash Adc, Low Power Folding And Interpolating Adc In Cmos 90nm Technology, Vinayashree Hiremath

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In recent years, signal processing has gained ample significance making high speed and low voltage analog-to-digital converters (ADC) inevitable in numerous applications. Two such ADCs designed in CMOS 90nm technology are presented in this thesis.

In flash ADC, thermometer to binary encoder often becomes bottleneck in achieving high speed. An encoder deploying new CMOS logic, with fewer transistors through the use of pseudo-dynamic circuits is described. This 4 bit flash ADC operates at 5GHz with an average power dissipation of 1.3mW.

Folding and interpolation significantly reduces the number of comparators used in flash architecture. A 6 bit 400MSPS low power …

Multi-User Signal Classification Via Cyclic Spectral Analysis, Brent Edward Guenther

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This research develops and evaluates several different methods for multi-user signal classification via cyclic spectral analysis. The first method uses the spectral correlation function (SCF) through temporal smoothing with the use of higher order cyclic statistics (HOCS) to allow for modulation classification. The second method uses the cyclic temporal cumulant function (CTCF) and the spectral coherence function (SOF) through frequency smoothing. Using a feature-based pattern recognition technique with the SOF can not only determine the number of signals present in the received signal, but can also give signal parameter estimation and group classification performance. The last method conducts further modulation …

Cellular Effects Of Replicating A Polypurine-Polypyrimidine Sequence And The Interactions Of Due-B With Replication Proteins, Shere Lynne Myers

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This work investigates two questions regarding DNA replication. The first aim examines the interactions of DUE-B with replication proteins and the second explores the cellular effects of replicating a polypurine polypyrimidine sequence in human cells.

DUE-B siRNA decreases the chromatin binding of essential replication proteins Cdc45, PCNA and RPA. DUE-B also co-immunoprecipitates with Cdc45 and TopBP1. In vitro kinase assays suggest that the checkpoint protein ATR may phosphorylate DUE-B. These experiments lend further evidence that DUE-B plays an important role in the initiation of eukaryotic DNA replication.

To investigate the effects of replicating a polypurine-polypyrimidine sequence prone to secondary structure …

Visualization Of Complex Unsteady 3d Flow: Flowing Seed Points And Dynamically Evolving Seed Curves With Applications To Vortex Visualization In Cfd Simulations Of Ultra Low Reynolds Number Insect Flight, Christopher M. Koehler

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Three dimensional integration-based geometric visualization is a very powerful tool for analyzing flow phenomena in time dependent vector fields. Streamlines in particular have many perceptual benefits due to their ability to provide a snapshot of the vectors near key features of complex 3D flows at any instant in time. However, streamlines do not lend themselves well to animation. Subtle changes in the vector field at each time step lead to increasingly large changes between streamlines with the same seed point the longer they are integrated. Path lines, which show particle trajectories over time suffer from similar problems when attempting to …

Fabrication And Analysis Of Compositionally Graded Functional Layers For Solid Oxide Fuel Cells, Jared Ray Mccoppin

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Solid Oxide Fuel Cell (SOFC) structures must be optimized for high performance, increased life, and low cost. Fabrication methods are an area of research interest in bringing down the total cost of SOFCs, and can also impact cell life and performance. Graded functional layers have been shown to enhance cell performance, but current fabrication methods require multiple fabrication steps. This thesis describes a novel fabrication method capable of compositional gradation of functional layers for SOFCs. Using colloidal spray deposition technology, a controlled co-deposition strategy was utilized to fabricate SOFC's with compositionally graded cathode and anode functional layers (CGCFL/CGAFL). In this …

A Human-Computer Integrated Approach Towards Content Based Image Retrieval, Phani Nandan Kidambi

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Digital photography technologies permit quick and easy uploading of any image to the web. Millions of images being are uploaded on the World Wide Web every day by a wide range of users. Most of the uploaded images are not readily accessible as they are not organized so as to allow efficient searching, retrieval, and ultimately browsing. Currently major commercial search engines utilize a process known as Annotation Based Image Retrieval (ABIR) to execute search requests focused on retrieving an image. Even though the information sought is an image, the ABIR technique primarily relies on textual information associated with an …

Design Of Hf Forward Transformer Including Harmonic Eddy Current Losses, Dhivya Ammanambakkam Nagarajan

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Pulse Width Modulated (PWM) Forward DC-DC converter is a buck-derived isolated power converter which is used extensively in low power to medium power applications. Satisfactory operation of the transformer utilized in forward converter plays a crucial role in the overall operation of the forward converter. Hence detailed analysis pertaining to design of forward transformer is important. The forward transformer is unique as the magnetizing inductance is not required to store magnetic energy. Additionally, the forward transformer has a tertiary winding, which is required to reset the core and to prevent core saturation. This adds to the complexity of design and …

Unconventional Uses Of Cantilevers For Chemical Sensing In Gas And Liquid Environments, Isabelle Dufour, Fabien Josse, Stephen M. Heinrich, C. Lucat, C. Ayela, F. Ménil, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Microcantilevers used as (bio)chemical sensors are usually coated with a chemically sensitive layer. The coated devices operate either in a static bending regime or in a dynamic flexural mode. While the coated devices operate generally well in both the static and dynamic mode, they do suffer from certain shortcomings depending on the medium of operation and the application, including lack of selectivity and of reversibility of the sensitive coating and a reduced quality factor due to the surrounding medium. In particular, the performance of microcantilevers excited in their standard out-of-plane dynamic mode drastically decreases in viscous liquid media. Moreover, the …

Design And Performance Analysis Of Genetic Algorithms For Topology Control Problems, Cem Safak Sahin

Dissertations, Theses, and Capstone Projects

In this dissertation, we present a bio-inspired decentralized topology control mechanism, called force-based genetic algorithm (FGA), where a genetic algorithm (GA) is run by each autonomous mobile node to achieve a uniform spread of mobile nodes and to provide a fully connected network over an unknown area. We present a formal analysis of FGA in terms of convergence speed, uniformity at area coverage, and Lyapunov stability theorem.

This dissertation emphasizes the use of mobile nodes to achieve a uniform distribution over an unknown terrain without a priori information and a central control unit. In contrast, each mobile node running our …

Performance Of Reinforced Concrete Columns Strengthened With Fiber Reinforced Polymers Under Various Loading Conditions, Mohamed Gamal Mohamed El Sayed

Theses

Strengthening of reinforced concrete (RC) structures with Carbon Fiber Reinforced Polymer (CFRP) composites has been a popular subject that attracted considerable attention from researchers for the last two decades. The high specific strength, stiffness, environmental resistance, and ease of application make CFRP composites highly desirable for strengthening and rehabilitation of RC structural components.

For concentrically loaded RC members with a circular cross-section, the lateral CFRP-confinement of concrete results in a substantial increase in load capacity and ductility. CFRP-confinement is less effective for RC compression members with square and rectangular cross-sections due to stress concentration at the corners and lack of …

Fabrication Of Polymeric Hollow Fiber Membrane For The Production Of Safe Drinking Water, Latifa Obeid Hamad Al-Nuaimi

Theses

Production of safe drinking water by using micro-filtration and ultra-filtration technologies has become more interesting. Water purification or filtration by using membrane began attracting much attention worldwide, because of its good characteristics such as: high efficiency in removing solid particles, viruses and germs and their low cost. This new technology is useful in industrial water treatment. The current studies in this field of polymer membrane manufacturing try to improve the characteristics, water flow rater and remove unwanted particles from water.

The recent project’s aim is to manufacture cellulose acetate hollow fibers. They were prepared by the Non Solvent Induced Phase …

Introducing Communication In Dis-Pomdps With Locality Of Interaction, Makoto Tasaki, Yuichi Yabu, Yuki Iwanari, Makoto Yokoo, Janusz Marecki, Pradeep Reddy Varakantham, Milind Tambe

Research Collection School Of Computing and Information Systems

The Networked Distributed POMDPs (ND-POMDPs) can model multiagent systems in uncertain domains and has begun to scale-up the number of agents. However, prior work in ND-POMDPs has failed to address communication. Without communication, the size of a local policy at each agent within the ND-POMDPs grows exponentially in the time horizon. To overcome this problem, we extend existing algorithms so that agents periodically communicate their observation and action histories with each other. After communication, agents can start from new synchronized belief state. Thus, we can avoid the exponential growth in the size of local policies at agents. Furthermore, we introduce …

Catalytic Oxidative Desulfurization Of A Model Diesel, Dongxing Liu

LSU Major Papers

An analysis of heterogeneous oxidation catalysts was performed to determine the activities and optimal operating conditions for the multiphase oxidative desulfurization (ODS) reactions, using a model diesel. Catalysts studied included well-characterized Pd on Al2O3 and activated carbon supports, and carbon-supported Mo2C and W2C, which were prepared by temperature programmed reaction. Several other typical oxidation catalysts were also examined. The model diesel consisted of ~1 wt% sulfur compounds (thiophene and dibenzothiophene) with appropriate amounts of aliphatic, alkylaromatic and N-heterocyclic compounds to simulate a raw number 2 diesel. With oxygen as the oxidant in ODS reactions of this model diesel (70-90ºC, 0.8-1.8 …