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Full-Scale Testing Of 40 Year Old Prestressed Aashto Girders That Have Been Retrofitted In Shear By Externally Applied Carbon Fiber Reinforced Polymer Wraps, David A. Petty 2010 Utah State University

Full-Scale Testing Of 40 Year Old Prestressed Aashto Girders That Have Been Retrofitted In Shear By Externally Applied Carbon Fiber Reinforced Polymer Wraps, David A. Petty

All Graduate Theses and Dissertations

The Utah Department of Transportation (UDOT) is interested in the application of rehabilitation techniques to strengthen their AASTHO prestressed bridge girders for shear. Utah's bridges are exposed to deterioration from rain, snow, and the introduction of salt for ice removable. This requires innovative rehabilitation techniques to address the deteriorations of their highway bridges, especially the ends of bridge girders where water and salt are more common due to construction joints. Carbon Fiber Reinforced Polymers (CFRP) are becoming more prevalent as a tool in highway bridge rehabilitation. This research investigates the application of various CFRP systems that can be used ...


Changes In Hybrid Poplar Endophytic Microbial Diversity In Response To Trichloroethylene Exposure, Jared S. Ervin 2010 Utah State University

Changes In Hybrid Poplar Endophytic Microbial Diversity In Response To Trichloroethylene Exposure, Jared S. Ervin

All Graduate Theses and Dissertations

Remediation of trichloroethylene (TCE) is a major priority for many contaminated sites all over the industrialized world including Hill Air Force Base, UT (HAFB). Phytoremediation as part of a cleanup strategy is an appealing option, and trees at HAFB have been studied to this end. Trees have also been used to delineate groundwater plumes because the passive uptake of organic contaminants by trees generally results in a direct relationship between tree and groundwater TCE concentrations if the trees are using the contaminated groundwater. However, the concentrations of plant-produced TCE metabolites can vary greatly. It was hypothesized that the endophytic microbial ...


Transesterification And Recovery Of Intracellular Lipids Using A Single Step Reactive Extraction, Daniel R. Nelson 2010 Utah State University

Transesterification And Recovery Of Intracellular Lipids Using A Single Step Reactive Extraction, Daniel R. Nelson

All Graduate Theses and Dissertations

A single-step, extractive reaction for extraction of lipids such as biodiesel components, omega-3 fatty acids, or other triglycerides from microbial cells was examined. Conventional methods for lipid extraction use toxic solvents, and require multiple steps and long processing times. When the goal is to produce fatty acid methyl esters or FAMEs, the extracted lipids are subjected to a separate transesterification reaction with simple alcohols in the presence of an acid or base catalyst. A simplified, single-step reactive extraction method can be applied that combines the sequential extraction followed by transesterification using acidified alcohols - a process known as in situ transesterification ...


Decentralized Coordination Of Multiple Autonomous Vehicles, Yongcan Cao 2010 Utah State University

Decentralized Coordination Of Multiple Autonomous Vehicles, Yongcan Cao

All Graduate Theses and Dissertations

This dissertation focuses on the study of decentralized coordination algorithms of multiple autonomous vehicles. Here, the term decentralized coordination is used to refer to the behavior that a group of vehicles reaches the desired group behavior via local interaction. Research is conducted towards designing and analyzing distributed coordination algorithms to achieve desired group behavior in the presence of none, one, and multiple group reference states. Decentralized coordination in the absence of any group reference state is a very active research topic in the systems and controls society. We first focus on studying decentralized coordination problems for both single-integrator kinematics and ...


Guidance And Navigation Linear Covariance Analysis For Lunar Powered Descent, Travis J. Moesser 2010 Utah State University

Guidance And Navigation Linear Covariance Analysis For Lunar Powered Descent, Travis J. Moesser

All Graduate Theses and Dissertations

A linear covariance analysis is conducted to assess closed-loop guidance, navigation, and control system (GN&C) performance of the Altair vehicle during lunar powered descent. Guidance algorithms designed for lunar landing are presented and incorporated into the closed-loop covariance equations. Navigation-based event triggering is also included in the covariance formulation to trigger maneuvers and control dispersions. Several navigation and guidance trade studies are presented demonstrating the influence of triggering and guidance and study parameters on the vehicle GN&C performance.


In-Pile Thermal Conductivity Measurement Methods For Nuclear Fuels, Brandon S. Fox 2010 Utah State University

In-Pile Thermal Conductivity Measurement Methods For Nuclear Fuels, Brandon S. Fox

All Graduate Theses and Dissertations

Measuring nuclear fuel thermal conductivity in-pile can provide much needed data for understanding fuel performance during irradiation and yield thermophysical property data needed for simulation codes and fuel databases. The objective of this research is to develop and compare two in-pile thermal conductivity methods in a laboratory setting using surrogate fuel materials.

A steady-state radial heat flow method was investigated to understand its viability as an in-pile steady-state thermal conductivity technique. By using Joule heating to simulate volumetric heat generation within a surrogate fuel rod, thermal conductivity was measured with two thermocouples at different radial positions within the rod. Examinations ...


Mathematical Modeling Of Light Utilization And The Effects Of Temperature Cycles On Productivity In A Steady-State Algal Photobioreactor, Peter Edwin Zemke 2010 Utah State University

Mathematical Modeling Of Light Utilization And The Effects Of Temperature Cycles On Productivity In A Steady-State Algal Photobioreactor, Peter Edwin Zemke

All Graduate Theses and Dissertations

The work presented here investigated two methods of improving productivity in microalgal photobioreactors: applying temperature cycles intended to maximize photosynthesis and minimize respiration, and development of a mathematical model that predicts improvements in photon utilization using temporal light dilution (flashing).

The experiments conducted on diurnal temperature cycles with Dunaliella tertiolecta in 30-L outdoor photobioreactors showed that a properly chosen temperature cycle can improve mass and energy productivity by 18% over an identical photobioreactor with a constant temperature. However, excessively large temperature cycle amplitudes reduced productivity. A 4-7% increase in energy content was observed in microalgae exposed to temperature cycles. The ...


The Utah Pilot Bridge, Live Load And Dynamic Testing, Modeling And Monitoring For The Long-Term Bridge Performance Program, Steven M. Petroff 2010 Utah State University

The Utah Pilot Bridge, Live Load And Dynamic Testing, Modeling And Monitoring For The Long-Term Bridge Performance Program, Steven M. Petroff

All Graduate Theses and Dissertations

As part of the Federal Highway Administration's Long-Term Bridge Performance Program, Live Load and Dynamic tests were conducted. A long-term monitoring plan was developed and presented for the Utah Pilot Bridge based on Live Load and Dynamic tests. As one of seven pilot bridges, the Utah Pilot Bridge is one of the first bridges used to initiate the LTBP Program. A formal permit approval process, with the Utah Department of Transportation, was followed to gain permission to conduct the tests and install long-term instrumentation. Analysis provided good results for each test completed, with a summary of test results presented ...


Micronetworking: Reliable Communication On 3d Integrated Circuits, Andres A. Contreras 2010 Utah State University

Micronetworking: Reliable Communication On 3d Integrated Circuits, Andres A. Contreras

All Graduate Theses and Dissertations

The potential failure in through-silicon vias (TSVs) still poses a challenge in trying to extend the useful life of a 3D integrated circuit (IC). A model is proposed to mitigate the communication problem in 3D integrated circuits caused by the breaks at the TSVs. We provide the details of a low-complexity network that takes advantages of redundant TSVs to make it possible to re-route around breaks and maintain effective communication between layers. Different configurations for the micronetwork are analyzed and discussed. We also present an evaluation of the micronetwork's performance, which turns out to be quite promising, based on ...


Thermo-Mechanical Reliability Of Micro-Interconnects In Three-Dimensional Integrated Circuits: Modeling And Simulation, Omar Rodriguez 2010 Utah State University

Thermo-Mechanical Reliability Of Micro-Interconnects In Three-Dimensional Integrated Circuits: Modeling And Simulation, Omar Rodriguez

All Graduate Theses and Dissertations

Three-dimensional integrated circuits (3D ICs) have been designed with the purpose of achieving higher communication speed by reducing the interconnect length between integrated circuits, and integrating heterogeneous functions into one single package, among other advantages. As a growing, new technology, researchers are still studying the different parameters that impact the overall lifetime of such packages in order to ensure the customer receives reliable end products. This study focused on the effect of four design parameters on the lifetime of the interconnects and, in particular, solder balls and through-silicon vias (TSVs). These parameters included TSV pitch, TSV diameter, underfill stiffness and ...


Comparative Studies On Oxygen Mass Transfer For The Design And Development Of A Single-Use Fermentor, Kristan L. Sorenson 2010 Utah State University

Comparative Studies On Oxygen Mass Transfer For The Design And Development Of A Single-Use Fermentor, Kristan L. Sorenson

All Graduate Theses and Dissertations

Accurate experimental oxygen mass transfer coefficient, a measure of how quickly oxygen travels from a gas bubble to the bulk liquid, is important for comparing performance and for evaluating the oxygen transfer capability of a fermentor. Delays in probe response and changing gas volumes upon start-up of gassing affect the accuracy of oxygen transfer measurements. To mitigate these inaccuracies, a standard correction procedure for oxygen mass transfer data was established for highly oxygenated, well-mixed fermentation systems. Probe response time correction was generated by applying a second-order response model to dissolved oxygen probes and shown to be effective within 4%. By ...


A Study Of Cause And Effect Relationships Of Snowmelt-Induced Movement For The Skunk Hollow Landslide, Brent P. Randall 2010 Utah State University

A Study Of Cause And Effect Relationships Of Snowmelt-Induced Movement For The Skunk Hollow Landslide, Brent P. Randall

All Graduate Theses and Dissertations

The Skunk Hollow Landslide (located 1 mile north of Mantua, UT along US-89) was instrumented with an automated monitoring system to aid in the determination of the triggering mechanism of slow moving landslides. Data was transmitted wirelessly through telecommunications to allow year-round, real-time monitoring of the site. Measurements were recorded and analyzed for the first season of landslide movement (fall 2009 to spring 2010) to better understand the correlations between snowmelt and movement initiation. Based on the first year of data, it appears that the Skunk Hollow Landslide is controlled by water infiltrating into the slide mass through cracks and ...


Integrated Solar Panel Antennas For Cube Satellites, Mahmoud N. Mahmoud 2010 Utah State University

Integrated Solar Panel Antennas For Cube Satellites, Mahmoud N. Mahmoud

All Graduate Theses and Dissertations

This thesis work presents an innovative solution for small satellite antennas by integrating slot antennas and solar cells on the same panel to save small satellite surface real estate and to replace deployed wire antennas for certain operational frequencies. The two main advantages of the proposed antenna are: 1) the antenna does not require an expensive deployment mechanism that is required by dipole antennas; 2) the antenna does not occupy as much valuable surface real estate as patch antennas. The antenna design is based on using the spacing between the solar cells to etch slots in these spaces to create ...


An Exploration Of Formal Methods And Tools Applied To A Small Satellite Software System, Russell J. Grover 2010 Utah State University

An Exploration Of Formal Methods And Tools Applied To A Small Satellite Software System, Russell J. Grover

All Graduate Theses and Dissertations

Formal system modeling has been a topic of interest in the research community for many years. Modeling a system helps engineers understand it better and enables them to check different aspects of it to ensure that there is no undesired or unexpected behavior and that it does what it was designed to do. This thesis takes two existing tools that were created to aid in the designing of spacecraft systems and creates a layer to connect them together and allow them to be used jointly. The first tool is a library of formal descriptions used to specify spacecraft behavior in ...


Micro Electro Mechanical Systems Integrated Frequency Reconfigurable Antennas For Public Safety Applications, Hema Swaroop Mopidevi 2010 Utah State University

Micro Electro Mechanical Systems Integrated Frequency Reconfigurable Antennas For Public Safety Applications, Hema Swaroop Mopidevi

All Graduate Theses and Dissertations

This thesis work builds on the concept of reconfiguring the antenna properties (frequency, polarization, radiation pattern) using Radio Frequency (RF) Micro Electro Mechanical Systems (MEMS). This is a part of the overall research performed at the RF Micro/Nano Electro Mechanical Systems (uNeMS) Laboratory at Utah State University, which includes design, microfabrication, test, and characterization of uNeMS integrated cognitive wireless communication systems (Appendix A).

In the first step, a compact and broadband Planar Inverted F Antenna (PIFA) is designed with a goal to accommodate reconfigurability at a later stage. Then, a Frequency Reconfigurable Antenna (FRA) is designed using MEMS switches ...


Fatigue Life Analysis Of T-38 Aileron Lever Using A Continuum Damage Approach, James D. Gyllenskog 2010 Utah State University

Fatigue Life Analysis Of T-38 Aileron Lever Using A Continuum Damage Approach, James D. Gyllenskog

All Graduate Theses and Dissertations

In a recent investigation conducted by the United States Air Force, the mechanical failure of the aileron lever, manufactured from 2014-T6 aluminum, caused the fatal mishap of a T-38 trainer aircraft. In general the locations of cracks are unknown and must be determined by simulation. In this study we propose to use a continuum damage modeling approach to determine the degradation and damage in a material as the number of cycles of loading increases. This approach successfully predicts the location of crack initiation, propagation path, and propagation rate. A stress-based model in conjunction with the successive initiation technique is utilized ...


The Hypericum Perforatum Herb As An Antimycobacterial Agent And Its Implications As An Additional Tuberculosis Medication, Trent W. Mortensen 2010 Utah State University

The Hypericum Perforatum Herb As An Antimycobacterial Agent And Its Implications As An Additional Tuberculosis Medication, Trent W. Mortensen

All Graduate Theses and Dissertations

An immediate demand exists for new tuberculosis (TB) antibiotics due to the ever-increasing spread of drug-resistant strains. The drug-development process goes through four phases, the first (Phase 0) of which is to demonstrate and investigate drug effectiveness and toxicity. This research investigated the effectiveness of the Hypericum perforatum herb (commonly St. John's wort (SJW)) in its growth inhibition of mycobacteria and its viability effect on human lung cells. Organic-solvent SJW extracts were effective at inhibiting every nonpathogenic genetically sequenced Mycobacterium isolate currently available (six isolates) in preliminary studies. Quantitative studies of five Mycobacterium isolates showed an order of concentration ...


Effects Of Submergence In Montana Flumes, Ryan P. Willeitner 2010 Utah State University

Effects Of Submergence In Montana Flumes, Ryan P. Willeitner

All Graduate Theses and Dissertations

As part of a continued research project for the Utah Water Research Laboratory and the State of Utah, a study of flow measurement devices is being conducted throughout the state. Initially the project included only measurement devices associated with high-risk dams, but has since been broadened to any measurement structure of interest for water users in the state. The physical dimensions, relative elevations, and flow accuracy were documented for each included device.

After visiting sixteen sites, it was found that fourteen of the measuring devices had incorrect geometries. Of these fourteen, thirteen of them were originally Parshall flumes. A large ...


Nutrient Utilization From Anaerobic Digester Effluent Through Algae Cultivation, Shantanu Wahal 2010 Utah State University

Nutrient Utilization From Anaerobic Digester Effluent Through Algae Cultivation, Shantanu Wahal

All Graduate Theses and Dissertations

Nutrients present in digested animal waste can be utilized for algae cultivation under suitable conditions. Algal growth, however, depends on the chemical forms and speciation of these nutrients. In this study a chemical equilibrium model was first used to describe nutrient speciation and predict conditions that enhance the solubility of nutrients in anaerobic digester effluent. Dilution with water and separation of large particulates greatly improved nutrient availability and light penetration - conditions favorable for algal cultivation. Algae growth was tested using three strains - Scenedesmus dimorphous (UTEX # 417), Chlorella vulgaris (UTEX# 265), and an algal isolate (designated as LLAI and later identified ...


Analog Front-End Design Using The Gm/Id Method For A Pulse-Based Plasma Impedance Probe System, Arun J. Rao 2010 Utah State University

Analog Front-End Design Using The Gm/Id Method For A Pulse-Based Plasma Impedance Probe System, Arun J. Rao

All Graduate Theses and Dissertations

The Plasma Impedance Probe (PIP) is an electronic instrument that measures the impedance of a dipole antenna immersed in a plasma environment. Measurements made by the PIP provide valuable information regarding the plasma environment. Knowledge of ionospheric plasma density and density disturbances is required to understand radio frequency communication with satellites. The impedance curve provides us with significant plasma characteristics such as the electron-neutral collision frequency and plasma electron density.

The work proposed here is a transistor-level implementation of the analog front-end, the non-inverting amplifier that is used to drive the antenna. The antenna immersed in plasma is excited with ...


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