Engineering Commons^™

A Portable Impedance Biosensing System Based On A Laptop With Labview For Rapid Detection Of Avian Influenza Virus, Yixiang Wang

Graduate Theses and Dissertations

Avian Influenza Virus (AIV) H5N1 is a highly pathogenic virus found not only in birds but also in human. Rapid and sensitive detection method is needed to help prevent the spread of AIV H5N1. In this study, a portable impedance biosensing system based on a laptop with LabVIEW software was developed for detection of AIV H5N1. First, a virtual instrument was programmed with LabVIEW software to form a platform for impedance measurement, data processing and control. The audio card of a laptop was used as a function generator while a data acquisition card was used with the signal channels for …

A Highly Adaptive And Cost Effective Second Generation Incubator (Sgi) Towards Educational, Research And Clinical Processes, Yassir H. Al-Sayagh

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Today´s rising demand for more reliable and affordable alternatives to organ transplant has led to a growing market for in vitro tissue culture systems. The main objective of tissue engineering as a whole is to employ human tissue equivalents for commercial use. The state-of-the-art processes for producing these so called tissue models are still very expensive, difficult to produce and time-consuming.

To engineer tissues, in vitro, a three-dimensional support structure commonly termed scaffold is needed. Stem cells are then added to the scaffold. In order for tissue to materialize, the scaffold and the cells must be incubated (cultured) at a …

Effect Of Enhanced Trackbed Support On Railway/Highway At-Grade Crossing Performance, Jerry G. Rose, Brett R. Malloy

Kentucky Transportation Center Research Report

This report documents the long-term performance of 89 railway/highway at-grade crossings in Kentucky and adjacent states that contain asphalt underlayment underneath the ballast. Asphalt underlayment increases load carrying capacity for trains and highway vehicles while enhancing the support structure’s waterproofing and confinement. The asphalt underlayment crossings studied were installed at sites that had historically exhibited poor performance and short service lives. Most of the crossing sites evaluated were 10-15 years old; however, their ages ranged up to 30 years. All of the crossings investigated have shown excellent performance since the installation of asphalt underlayments. No crossing failures, such as excessive …

Performance Of Frp-Retrofitted Concrete Bridge Columns Under Blast Loading, R. Zheng, P. Zohrevand, H. Erdogan, Amir Mirmiran

Civil Engineering Faculty Publications and Presentations

Contrary to military or essential government buildings, most bridges are designed without any consideration for blast resistance. Fiber-reinforced polymers (FRPs) can provide an effective means for strengthening of critical bridges against such loading. This study has focused on the effectiveness of FRP retrofitting in the dynamic response of reinforced concrete bridge columns under blast loading. Using a simplified equivalent I-section with a virtual material lumped at the two flanges; a lightly meshed uniaxial finite element model was developed and successfully validated against previous studies. The proposed model was then used for a thorough parametric study on the blast resistance of …

Identification Of Groundwater Sources For Municipal Wells Using Geochemical Data On The Platte Alluvial Aquifer And Underlying Limestone At The Lincoln Water Well Field Near Ashland Nebraska, Juanita Cruz Torres

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Alluvial aquifer systems where pumping of municipal wells induces recharge from the adjacent river are the primary source of water for many cities. The city of Lincoln, NE has a primary water source in an alluvial aquifer adjacent to the Platte River. The Lincoln Water System manages the stream/aquifer system by using integrated models for a better understanding during periods of high stress such as a drought. The integrated models set the limestone aquifer as an impermeable boundary to understand the alluvial aquifer system without having a secondary water source. The limestone aquifer is permeable and the purpose of this …

A Deep Search Architecture For Capturing Product Ontologies, Tejeshwar Sangameswaran

Graduate Theses and Dissertations

This thesis describes a method to populate very large product ontologies quickly. We discuss a deep search architecture to text-mine online e-commerce market places and build a taxonomy of products and their corresponding descriptions and parent categories. The goal is to automatically construct an open database of products, which are aggregated from different online retailers. The database contains extensive metadata on each object, which can be queried and analyzed. Such a public database currently does not exist; instead the information currently resides siloed within various organizations. In this thesis, we describe the tools, data structures and software architectures that allowed …

Radiation-Induced Effects In Chalcogenide-Based Memory Devices And Films, Kasandra Wolf

Boise State University Theses and Dissertations

Continued scaling of memory devices has produced many issues for the current foremost non-volatile memory—the flash memory—leading to the emergence of a wide variety of alternative memory solutions. Redox Conductive Bridge Memory (RCBM) is one such solution that has shown great promise in recent years. However, the performance of these devices under radiation conditions has not been explored in detail. This work investigates the effects of x-rays and electron bombardment on chalcogenide glasses and RCBM devices based on these materials.

RCBM devices are a form of Resistance Change Memory, which rely on two distinct resistive states to represent the binary …

Utilization Of Aqueous Raft Prepared Copolymers To Improve Anticancer Drug Efficacy, Andrew Christopher Holley

Dissertations

The advent of controlled radical polymerization (CRP) techniques, along with advancements in facile conjugation chemistry, now allow synthetic tailoring of precise, polymeric architectures necessary for drug/gene delivery. Reversible addition- fragmentation chain transfer (RAFT) polymerization and its aqueous counterpart (aRAFT) afford quantitative control over key synthetic parameters including block length, microstructure, and placement of structo-pendent and structo-terminal functionality for conjugation of active agents and targeting moieties. The relevance of water-soluble and amphiphilic (co)polymers synthesized by RAFT for in vitro delivery of therapeutics in biological fluids is an especially attractive feature. In many cases, polymerization, binding, conjugation, …

Kinetic Experimental And Modeling Studies On Iron-Based Catalysts Promoted With Lanthana For The High-Temperature Water-Gas Shift Reaction Characterized With Operando Uv-Visible Spectroscopy And For The Fischer-Tropsch Synthesis, Basseem Bishara Hallac

Theses and Dissertations

The structural and functional roles of lanthana in unsupported iron-based catalysts for the high-temperature water-gas shift reaction and Fischer-Tropsch synthesis were investigated. The performance of the catalysts with varying lanthana contents was based on their activity, selectivity, and stability. With regard to the former reaction, extent of reduction of the iron in Fe2O3/Cr2O3/CuO/La2O3 water-gas shift catalysts is a key parameter that was characterized using UV-visible spectroscopy. Minor addition of lanthana (<0.5 wt%) produces more active and stable catalysts apparently because it stabilizes the iron-chromium spinel, increases the surface area of the reduced catalysts, enhances the reduction of hematite to the magnetite active phase, and facilitates the adsorption of CO on the surface of the catalyst modeled by an adsorptive Langmuir-Hinshelwood mechanism. Statistical 95% confidence contour plots of the adsorption equilibrium constants show that water adsorbs more strongly than CO, which inhibits the reaction rate. A calibration curve that correlates the oxidation state of surface iron domains to normalized absorbance of visible light was successfully generated and applied to the water-gas shift catalysts. UV-visible studies indicated higher extent of reduction for surface Fe domains for the catalysts promoted with 1 wt% of lanthana and showed potential to be a more convenient technique for surface chemistry studies than X-ray absorption near edge spectroscopy (XANES). Lanthana addition to iron-based Fischer-Tropsch catalysts enhances the olefin-to-paraffin ratio, but decreases their activity, stability, and selectivity to liquid hydrocarbons. Adding lanthana at the expense of potassium reduces the water-gas shift selectivity and enhances the activity and stability of the catalysts. Finally, a model that simulates heat and mass transfer limitations on the particle scale for the Fischer-Tropsch reaction applicable at lab-scale suggests optimal operating and design conditions of 256°C, 30 bar, and 80 mirons are recommended for higher selectivity to liquid hydrocarbons. The model considers pressure drop, deactivation, pore diffusion, film heat transfer, and internal heat transfer when solving for the optimal conditions, and maps them as functions of design variables. This model can be up-scaled to provide guidance for optimal design of commercial-size reactors.

Axial Compression Behavior Of Unidirectional Carbon/Epoxy Tubes And Rods Before And After Impact, Ian Michael Oxborrow

Theses and Dissertations

Compression tests were performed on damaged and undamaged rods and tubes made from unidirectional carbon/epoxy composite and lightweight core materials. Tested samples represent local members in an open, three-dimensional, composite lattice structure. Testing was performed in order to establish effective core materials to use in order to increase the buckling length of local IsoTruss® members while maintaining low weight. Members were formed from T700SC-12K-50C carbon fiber with UF6639-100 resin. Core materials consisted of 3/8-inch (0.953 cm) outside diameter Teflon® rods, Teflon® tubes, nylon rods, nylon tubes, Ertalyte® rods, and Duratron® rods. All 3/8-inch (0.953-cm) cores were each surrounded by 50 …

Developments In Lfm-Cw Sar For Uav Operation, Craig Lee Stringham

Theses and Dissertations

Opportunities to use synthetic aperture radar (SAR) in scientific studies and military operations are expanding with the development of small SAR systems that can be operated on small unmanned air vehicles (UAV)s. While the nimble nature of small UAVs make them an attractive platform for many reasons, small UAVs are also more prone to deviate from a linear course due autopilot errors and external forces such as turbulence and wind. Thus, motion compensation and improved processing algorithms are required to properly focus the SAR images. The work of this dissertation overcomes some of the challenges and addresses some of the …

Influence Of Pile Shape On Resistance To Lateral Loading, Guillermo Bustamante

Theses and Dissertations

The lateral resistance of pile foundations has typically been based on the resistance of circular pipe piles. In addition, most instrumented lateral load tests and cases history have involved circular piles. However, piles used in engineering practice may also be non-circular cross-section piles such as square and H piles. Some researchers have theorized that the lateral resistance of square piles will be higher than that of circular piles (Reese and Van Impe, 2001; Briaud et al, 1983; Smith, 1987) for various reasons, but there is not test data to support this claims. To provide basic comparative performance data, lateral load …

Shear-Dominated Bending Behavior Of Carbon/Epoxy Composite Lattice Isobeam Structures, Kirsten Bramall Hinds

Theses and Dissertations

Composite lattice structures known as the IsoBeam™ made with unidirectional carbon/epoxy were manufactured and tested in shear-dominated bending. The manufacturing process consisted of placing tows of carbon fiber pre-impregnated with epoxy resin onto a pin-type mandrel to create members with interwoven joints. The members were consolidated with a half spiral aramid sleeve. The IsoBeam structure consists of two main types of members: longitudinal and diagonal members measuring nominally 0.4 in. (10.2 mm) and 0.2 in. (5.1 mm) in diameter, respectively. The hand-manufactured specimens measured nominally 6 in. (152.4 mm) high by 3 in. (76.2 mm) wide by 2 ft (0.61 …

Evaluation Of Current Empirical Methods For Predicting Lateral Spread-Induced Ground Deformations For Large Magnitude Earthquakes Using Maule Chile 2010 Case Histories, Ginger Emily Tryon

Theses and Dissertations

Improving seismic hazard analysis is an important part of building safer structures and protecting lives. Since large magnitude earthquakes are rarer than other earthquakes, it is harder to model seismic hazards such as lateral spread displacements for these events. Engineers are often required to extrapolate current lateral spreading models when designing utilities, bridges, and piers to withstand the ground displacements caused by earthquakes with magnitudes larger than 8.0. This study uses three case histories from the Maule Chile 2010 earthquake (Mw =8.8) to develop recommendations on which models are most accurate for large earthquake events and how to improve the …

Investigating The Relationship Between High Temperature Flow Stress And Friction Stir Weldability In Hsla Steels, David Jordan Walser

Theses and Dissertations

The feed rate at which a defect free friction stir weld can be run (friction stir weldability) on an HSLA steel plate can vary widely between heats that meet the same specified physical properties. Consequently, every time a new heat of HSLA steel is obtained, exploratory welds must be run to determine the proper feed rate for that plate. Previous research suggests that the varying levels of alloying elements related to high temperature physical properties between the different heats causes the observed change in friction stir weldability. Because of this, it was hypothesized that the high temperature physical properties of …

Latin American Data Drought: An Assessment Of Available River Observation Data In Select Latin American Countries And Development Of A Web-Based Application For A Hydrometerological Database System In Spanish, Stephen Joseph Bolster

Theses and Dissertations

The demand and collection of hydrometeorological data is growing to support hydrologic and hydraulic analyses, and other studies. These data can amount to extensive information that requires sound data management to enable efficient storage, access, and use. While much of the globe is using technology to efficiently collect and store hydrometeorological data, other parts, such as developing countries, are unable to do so. This thesis presents an assessment of available river observations data in Latin American countries in Central America and the Caribbean. The assessment analyzes 1) access to available data, 2) spatial density of data, and 3) the temporal …

Tincr: Integrating Custom Cad Tool Frameworks With The Xilinx Vivado Design Suite, Brad S. White

Theses and Dissertations

The field programmable gate array (FPGA) is appealing as a computational platform because of its ability to be repurposed for a number of different applications and its relatively low design cost. Traditionally, FPGA vendors provide a set of electronic design automation (EDA) tools to assist customers with the implementation of their designs. These tools are necessarily general purpose, and the resulting tool flow does not provide the user much in the way of customization. Frameworks such as RapidSmith and Torc allow for the creation of custom CAD tools that are able to target actual Xilinx FPGA devices. However, they are …

Design And Implementation Of An Inverse Modeling Framework Using The Method Of Anchored Distributions, Carlos Andres Osorio Murillo

Theses and Dissertations

Estimation of spatial random fields (SRFs) such as transmissivity or porosity is required for predicting groundwater flow and subsurface contaminant movement. Similarly, distributed parameter fields such as terrain roughness and evapotranspiration coefficients are required by other areas of environmental and earth sciences modeling. This dissertation presents an inverse modeling framework for characterizing SRFs called MAD#, which is an end-user software implementation of the Bayesian inverse modeling technique Method of Anchored Distributions (MAD). The MAD# framework allows modelers to “wrap” existing simulation modeling tools using an extensible driver architecture that exposes model parameters to the inversion engine. A compelling aspect of …

Orientations Of Low-Energy Domain Walls In Perovskites With Oxygen Octahedral Tilts, Fei Xue, Yijia Gu, Linyun Liang, Yi Wang, Long-Qing Chen

Materials Science and Engineering Faculty Research & Creative Works

Many applications of ferroic materials, such as data storage and spintronics, are achieved through the control and manipulation of their domain wall (DW) orientations and configurations. Here we propose a rotational compatibility condition to identify low-energy DWs in perovskites with oxygen octahedral tilt instability. It is derived from the strong DW energy anisotropy arising from the rigidity and corner-sharing feature of the octahedral network. We analyze quantitatively the DWs in SrTiO₃ and explain successfully the unusual ferroelectric DW width and energy in BiFeO₃.

Secure Degrees Of Freedom For The Mimo Wiretap Channel With A Multiantenna Cooperative Jammer, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

A multiple antenna Gaussian wiretap channel with a multiantenna cooperative jammer (CJ) is considered and the secure degrees of freedom (s.d.o.f.), with N antennas at the sender, receiver, and eavesdropper, is derived for all possible values of the number of antennas at the cooperative jammer, K. In particular, the upper and lower bounds for the s.d.o.f. are provided for different ranges of K and shown to coincide. Gaussian signaling both for transmission and jamming is shown to be sufficient to achieve the s.d.o.f. of the channel, when the s.d.o.f. is integer valued. By contrast, when the channel has a non-integer …

Traffic Safety Primer For Local Agencies, Indiana Ltap, Michigan Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

The purpose of this booklet is to empower local agency personnel to make informed decisions that can improve roadway safety in your community. By identifying and addressing potential roadway hazards, you can reduce the likelihood of a future traffic crash for your community and your family. Adapted by permission from the Michigan LTAP’s 2008 Publication What Elected Officials Need to Know About Traffic Safety (And What YOUR Constituents Expect YOU to Know!)

Fabrication And Characterization Of Antioxidant Loaded Liposomes., Brian Gettler

Electronic Theses and Dissertations

Radiation exposure is both a major obstacle in space exploration and an occupational hazard for various careers causing DNA damage and ROS. In order to reduce the effects of radiation, the primary and most explored approach has been focused around mitigation in terms of exposure duration, exposure intensity, and shielding usage. In some situations none of these reduction strategies were viable and so the use of antioxidants is being explored as an alternate strategy for therapeutic purposes. One such antioxidant is curcumin, otherwise known as diferuloylmethane, is a component of turmeric with both antioxidant properties and anti-inflammatory properties. Another antioxidant …

Fabrication Of A Thin Silver Nanowire Composite Film And Investigation Of A Patterning Technique., Richard S. Korte 1991-

Electronic Theses and Dissertations

Electrically conductive polymers encompass an exciting field of research for applications in dye-sensitized solar cells (DSSC’s). DSSC’s possess several advantages over other types of solar cells. They offer the potential for high quantum efficiency, solar conversion efficiency approaching that of traditional silicon panels, rapid charge transfer kinetics for photo-excited electrons, mechanical flexibility, and cost efficient manufacturing processes. However, key drawbacks to their large scale production and performance lifetime lie in their reliance on costly indium tin oxide (ITO), fluorinated tin oxide (FTO), and platinum for electrode materials, and the mechanical fragility inherent to a liquid electrolyte layer component. Much of …

Estimating Field At-Rest Lateral Stress Coefficient And Liquefaction Resistance Of Aged Sands, Md Hossian

All Dissertations

Published results of laboratory tests to evaluate the influence of the at-rest lateral stress coefficient (K0) and the overconsoildation ratio (OCR) on liquefaction resistance of sands are reviewed in this dissertation. It is found that significant increase in liquefaction resistance can occur with high K0 and/or high OCR. A unique relationship between liquefaction resistance of isotropic and anisotropic normally consolidated sands exists based on the published laboratory data. Relationships between liquefaction resistance of overconsolidated sands and normally consolidated sands also have been shown in previous laboratory studies. Based on the previous studies, expressions for K0 and OCR correction factors (KK0 …

Low Speed Water Tunnel Testing, John J. Taylor

Theses and Dissertations - UTB/UTPA

Water tunnels are ideal for studying flow patterns for hydrodynamic effects. The functionality of the University of Texas-Pan American water tunnel was limited by not being able to measure forces and moments corresponding to flow patterns. This report delivers an experimental set-up for calibrating the velocity of the water and development of a load measuring system to relate simultaneous visual investigation. An in-depth parts breakdown of the SST-model pump and the dye injection system for flow visualization will be reviewed. Few balances have been made for water tunnels due to small and difficult to measure flow-induced forces. The motive is …

A 129nw Neural Amplifier And Gm-C Filter For Eeg Using Gm/Id Methodology, Samuel A. Gallegos

Theses and Dissertations - UTB/UTPA

This Thesis presents a low-power analog front-end amplifier and Gm-C filter for biomedical sensing applications, specifically for Electroencephalogram (EEG) use. The proposed neural amplifier uses a supply voltage of 1.8V, it has a mid-band gain of 40.75dB, and consumes a total current of 71.82nA, for a total dissipated power of 129.276nW. Also presented is the design of a 3rd order Butterworth Low Pass Gm-C Filter which makes use of 14.7nS transconductors; the proposed filter has a pass band suitable for EEG recording use (1-100Hz). The amplifier and filter utilize current sources without bias resistances which provide 56nA and (1.154nA x …

Applications Of Magnetostrictive Materials In The Real-Time Monitoring Of Vehicle Suspension Components, Raul Estrada

Theses and Dissertations - UTB/UTPA

The purpose of this project is to explore applications of magnetostrictive materials for real-time monitoring of railroad suspension components, in particular bearings. Monitoring of such components typically requires the tracking of temperature vibration and load. In addition, real-time, long-term monitoring can be greatly facilitated through the use of wireless, self-powered sensors. Magnetostrictive materials, such as Terfenol-D, have the potential to address both requirements. Currently, piezoelectrics are used for many load and energy harvesting applications; however, they are fragile and are difficult to use for static load measurements. Magnetostrictive metals are tougher, and their property of variable permeability when stressed can …

Effects Of Vapor Grown Carbon Nanofibers On Electrical And Mechanical Properties Of A Thermoplastic Elastomer, Daniel Thomas Basaldua

Theses and Dissertations - UTB/UTPA

Carbon nanofiber (CNF) reinforced composites are exceptional materials that exhibit superior properties compared to conventional composites. This paper presents the development of a vapor grown carbon nanofiber (VGCNF) thermoplastic polyurethane (TPU) composite by a melt mixing process. Dispersion and distribution of CNFs inside the TPU matrix were examined through scanning electron microscopy to determine homogeneity. The composite material underwent durometer, thermal gravimetric analysis, differential scanning calorimetry, heat transfer, hysteresis, dynamic modulus, creep, tensile, abrasion, and electrical conductivity testing to characterize its properties and predict behavior. The motivation for this research is to develop an elastomer pad that is an electrically …

Fatigue Damage Prognosis Of Internal Delamination In Composite Plates Under Cyclic Compression Loadings Using Affine Arithmetic As Uncertainty Propagation Tool, Audrey J-M Gbaguidi

Doctoral Dissertations and Master's Theses

Structural health monitoring (SHM) has become indispensable for reducing maintenance costs and increasing the in-service capacity of a structure. The increased use of lightweight composite materials in aircraft structures drastically increased the effects of fatigue induced damage on their critical structural components and thus the necessity to predict the remaining life of those components. Damage prognosis, one of the least investigated fields in SHM, uses the current damage state of the system to forecast its future performance by estimating the expected loading environments. A successful damage prediction model requires the integration of technologies in areas like measurements, materials science, mechanics …

Indium Telluride Cylinder Fiber Laser, Abhinay Sandupatla

Theses - ALL

A new type of fiber laser is described here. The laser consists of a 25 mm long fiber with an approximately 15 nm thick In2Te3 semiconductor layer at the glass core glass cladding boundary. The laser mirrors consist of a thick vacuum deposited aluminum layer at one end and a thin semitransparent aluminum layer deposited at the other end of the fiber. The laser is pumped from the side with either light from a Halogen Tungsten incandescent lamp or a blue, power LED. Since both, the gain of the In2Te3 semi-conductor and aluminum mirrors have a wide bandwidth the output …