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Articles 3481 - 3510 of 4850

Full-Text Articles in Engineering

Characterization Of The Initial Flow Rate Of Information During Reverse Engineering, Nicole Anderson Apr 2011

Characterization Of The Initial Flow Rate Of Information During Reverse Engineering, Nicole Anderson

Theses and Dissertations

The future of companies that are founded on the development of new and innovative products is threatened when competitors reverse engineer and imitate the products. If the original developers could predict how long it would take a competitor to reverse engineer a product, it may be possible for them to delay, if not prevent, that competitor's entry into the market. Metrics and measures have been developed that can estimate the time it would take an individual to reverse engineer a product. The main purpose of these metrics and measures is to help designers determine how quickly a competitor could reverse …

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Three-Dimensional Numerical Simulations Of Liquid Laminar Flow Over Superhydrophobic Surfaces With Post Geometries, Abolfazl Amin Apr 2011

Three-Dimensional Numerical Simulations Of Liquid Laminar Flow Over Superhydrophobic Surfaces With Post Geometries, Abolfazl Amin

Theses and Dissertations

Frictional resistance reduction of liquid flow over surfaces has recently become a more important topic of research in the field of fluid dynamics. Scientific and technological progress and continued interest in nano and micro-technology have required new developments and approaches related to reducing frictional resistance, especially in liquid flow through nano and micro-channels. The application of superhydrophobic surfaces could be very effective in achieving the desired flow through such small channels. Superhydrophobic surfaces are created by intentionally creating roughnesses on the surface and applying a uniform hydrophobic coating to the entire surface. Liquid droplet tests have revealed that because of …

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Return On Investment Analysis For Implementing Barriers To Reverse Engineering And Imitation, Darren C. Knight Apr 2011

Return On Investment Analysis For Implementing Barriers To Reverse Engineering And Imitation, Darren C. Knight

Theses and Dissertations

Reverse engineering (extracting information about a product from the product itself) is a competitive strategy for many firms and is often costly to innovators. Recent research has proven metrics for estimating the reverse engineering time and barrier and has shown that products can strategically be made more difficult to reverse engineer, thus protecting the innovator. Reverse engineering, however, is only the first phase of attempting to duplicate a product. Imitating – the process of discovering how to physically reproduce the performance of the reverse engineered product in one or more of its performance areas – is the second and final …

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Experimental Investigation Of Steel Pipe Pile To Concrete Cap Connections, Ryan S. Eastman Apr 2011

Experimental Investigation Of Steel Pipe Pile To Concrete Cap Connections, Ryan S. Eastman

Theses and Dissertations

Piles are often used to resist vertical and lateral loads when shallow foundations are inadequate or uneconomical. A critical part in designing pile foundations is the pile-to-cap connection. When a moment resisting connection is desired, reinforcement is typically used between the pile and the cap. A pile-to-cap connection with sufficient pile embedment depth, however, may provide similar results. One model that is currently used to determine the capacity of a pile-to-cap connection was developed by Marcakis and Mitchell for steel members embedded in concrete. This model considers an embedment mechanism that resists rotation at the connection. Recent testing has shown, …

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Factors Affecting The Strength Of Road Base Stabilized With Cement Slurry Or Dry Cement In Conjunction With Full-Depth Reclamation, Paul A. Dixon Apr 2011

Factors Affecting The Strength Of Road Base Stabilized With Cement Slurry Or Dry Cement In Conjunction With Full-Depth Reclamation, Paul A. Dixon

Theses and Dissertations

Full-depth reclamation (FDR) in conjunction with cement stabilization is an established practice for rehabilitating deteriorating asphalt roads. Conventionally, FDR uses dry cement powder applied with a pneumatic spreader, creating undesirable fugitive cement dust. The cement dust poses a nuisance and, when inhaled, a health threat. Consequently, FDR in conjunction with conventional cement stabilization cannot generally be used in urban areas. To solve the problem of fugitive cement dust, the use of cement slurry, prepared by combining cement powder and water, has been proposed to allow cement stabilization to be utilized in urban areas. However, using cement slurry introduces several factors …

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Nanocomposite High Displacement Strain Gauges For Use In Human-Machine Interfaces: Applications In Hand Pose Determination, Thomas B. Calkins Apr 2011

Nanocomposite High Displacement Strain Gauges For Use In Human-Machine Interfaces: Applications In Hand Pose Determination, Thomas B. Calkins

Theses and Dissertations

Conductive nanocomposites are finding many uses as multi-functional materials. One recent development involves the creation of high displacement strain gauges, which have potential applications in a variety of engineering roles. The piezoresistive nature of the gauges makes possible their strain sensing capability. The intent of this research is to show that specific High Displacement Strain Gauges can successfully be used in one human-machine interface application that will demonstrate their potential for a range of other human-machine interface applications. This will be shown in the development of these sensors to accomplish hand pose determination. The flexible and inexpensive gauges are attached …

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Field Algae Measurements Using Empirical Correlations At Deer Creek Reservoir, Ryan A. Stephens Apr 2011

Field Algae Measurements Using Empirical Correlations At Deer Creek Reservoir, Ryan A. Stephens

Theses and Dissertations

Deer Creek Reservoir in Utah has a history of high algae concentrations. Despite recent nutrient reduction efforts, seasonal algae continue to present problems. Cost effective, accurate, and comprehensive monitoring is important to understand the reservoir processes driving this problem and characterizing the algae spatial and temporal distributions are an important part of this effort. Current laboratory methods for accurately measuring algae are expensive and time consuming and are based on water samples taken in the field and transported to the laboratory. This approach only provides data for relatively few point samples because of the time and expense of sample collection …

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Modeling, Design, And Testing Of An Underwater Microactuation System Using A Standard Mems Foundry Process, Gregory L. Holst Apr 2011

Modeling, Design, And Testing Of An Underwater Microactuation System Using A Standard Mems Foundry Process, Gregory L. Holst

Theses and Dissertations

This work presents the modeling, design, and testing of an underwater microactuation system. It is composed of several thermomechanical in-plane microactuators (TIM) integrated with a ratchet system to provide long displacements and high forces to underwater microelectromechanical systems (MEMS). It is capable of actuating a 200µN load 110µm. It is a two-layer silicon MEMS device fabricated with a MEMS fabrication process, PolyMUMPS. This work also shows the development of an elliptic integral model to analyze the compliant fixed-guided beams in the TIM and gives new insight into the buckling behavior, reaction forces, and displacement of the beams. The derivation, verification, …

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A Multifaceted Sedimentological Analysis On Hobble Creek, Andrew S. Dutson Apr 2011

A Multifaceted Sedimentological Analysis On Hobble Creek, Andrew S. Dutson

Theses and Dissertations

Due to the endangerment of the June sucker (Chasmistes liorus), the lower two miles of Hobble Creek, Utah has been the focus of several restoration efforts. The portion of the creek between Interstate 15 and Utah Lake has been moved into a more "natural" channel and efforts are now being made to expand restoration to the east side of the freeway. This thesis reports on three different parts of a sedimentological analysis performed on Hobble Creek. The first part is a data set that contains information about the particle size distribution on the bed of Hobble Creek between …

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An Analysis Of Analytical Methods To Produce A Varying Angular Output From A Constant Angular Input Using Gearsets, Isaac R. Jones Apr 2011

An Analysis Of Analytical Methods To Produce A Varying Angular Output From A Constant Angular Input Using Gearsets, Isaac R. Jones

Theses and Dissertations

Research in developing a Positively Engaged Continuously Variable Transmission (PECVT) has been underway at Brigham Young University for some time. The inherent problems associated with embodiments of this type of transmission, namely the Non-Integer Tooth Problem (NITP), have been identified. This research is focused on the development of a Positively Engaged Piecewise Continuous Transmission (PEPCT), which is a subset of the PECVT. This document describes the hypothesis and analysis of using non-circular gearsets to overcome the NITP. This proposed solution enables a varying angular output from a constant angular input. In this research two analytical methods were evaluated based on …

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Fluxes Across Double-Diffusive Interfaces: A One-Dimensional-Turbulence Study, Esteban Gonzalez-Juez, Alan R. Kerstein, David O. Lignell Apr 2011

Fluxes Across Double-Diffusive Interfaces: A One-Dimensional-Turbulence Study, Esteban Gonzalez-Juez, Alan R. Kerstein, David O. Lignell

Faculty Publications

This work is a parametric study of the fluxes of heat and salt across unsheared and sheared double-diffusive interfaces using one-dimensional-turbulence (ODT) simulations. It is motivated by the need to understand how these fluxes scale with parameters related to the fluid molecular properties and background shear. Comparisons are made throughout with previous models and available measurements. In unsheared interfaces, ODT simulations show that the dimensionless heat flux Nu scales with the stability parameter Rρ, Rayleigh number Ra and Prandtl number Pr as Nu ~ (Ra/Rρ)0.37±0.03 when Pr varies from 3 to 100 and as Nu ~ (Ra/Rρ)0.31Pr0.22±0.04 when Pr varies …

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Strain Monitoring Of Carbon Fiber Composite With Embedded Nickel Nano-Composite Strain Gage, Timothy Michael Johnson Apr 2011

Strain Monitoring Of Carbon Fiber Composite With Embedded Nickel Nano-Composite Strain Gage, Timothy Michael Johnson

Theses and Dissertations

Carbon fiber reinforced plastic (CFRP) composites have extensive value in the aerospace, defense, sporting goods, and high performance automobile industries. These composites have huge benefits including high strength to weight ratios and the ability to tailor their properties. A significant issue with carbon fiber composites is the potential for catastrophic fatigue failure. To better understand this fatigue, there is first a huge push to measure strain accurately and in-situ to monitor carbon fiber composites. In this paper, piezoresistive nickel nanostrand (NiNs) nanocomposites were embedded in between layers of carbon fiber composite for real time, in situ strain monitoring. Several different …

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The Composition And Distribution Of Coal-Ash Deposits Under Reducing And Oxidizing Conditions From A Suite Of Eight Coals, David R. Brunner Apr 2011

The Composition And Distribution Of Coal-Ash Deposits Under Reducing And Oxidizing Conditions From A Suite Of Eight Coals, David R. Brunner

Theses and Dissertations

Eighteen elements, including: carbon, oxygen, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, chlorine, potassium, calcium, titanium, chromium, manganese, iron, nickel, strontium, and barium were measured using a scanning electron microscope with energy dispersive spectroscopy from deposits. The deposits were collected by burning eight different coals in a 160 kWth, staged, down-fired, swirl-stabilized combustor. Both up-stream and down-stream deposits from an oxidizing region (equivalence ratio 0.86) and reducing region (equivalence ratio 1.15) were collected. Within the deposits, the particle size and morphology were studied. The average particle cross-sectional area from the up-stream deposits ranged from 10 - 75 µm2 and had a …

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Multi-Resolution Obstacle Mapping With Rapidly-Exploring Random Tree Path Planning For Unmanned Air Vehicles, Brett Wayne Millar Apr 2011

Multi-Resolution Obstacle Mapping With Rapidly-Exploring Random Tree Path Planning For Unmanned Air Vehicles, Brett Wayne Millar

Theses and Dissertations

Unmanned air vehicles (UAVs) have become an important area of research. UAVs are used in many environments which may have previously unknown obstacles or sources of danger. This research addresses the problem of obstacle mapping and path planning while the UAV is in flight. Online obstacle mapping is achieved through the use of a multi-resolution map. As sensor information is received, a quadtree is built up to hold the information based upon the uncertainty associated with the measurement. Once a quadtree map of obstacles is built up, we desire online path re-planning to occur as quickly as possible. We introduce …

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Fm Demodulators In Software-Defined Radio Using Fpgas With Rapid Prototyping, Marc Anthony Padilla Mar 2011

Fm Demodulators In Software-Defined Radio Using Fpgas With Rapid Prototyping, Marc Anthony Padilla

Theses and Dissertations

With the advent of software-defined radio, many radio applications have and are currently being designed for FPGAs, due to their high performance and reconfigurability. Invariably, "legacy" waveforms, such as FM, will need to be supported in such systems. A challenge that comes with programming FPGAs is the increased design and implementation time over conventional software programming. In this thesis, three FM demodulator techniques are implemented and compared in an FPGA. Two techniques are found to have similar SNR performance while having very different FPGA implementation characteristics. Library based design is explored for demodulators to increase FPGA design productivity. A block …

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Evaluation Of Portable Devices For Monitoring Microcracking Of Cement-Treated Base Layers, Charles A. Hope Mar 2011

Evaluation Of Portable Devices For Monitoring Microcracking Of Cement-Treated Base Layers, Charles A. Hope

Theses and Dissertations

A relatively new method used to reduce the amount of cement-treated base (CTB) shrinkage cracking is microcracking of the CTB shortly after construction. Three portable instruments used in this study for monitoring the microcracking process include the heavy Clegg impact soil tester (CIST), portable falling-weight deflectometer (PFWD), and soil stiffness gauge (SSG). The specific objectives of this research were 1) to evaluate the sensitivity of each of the three portable instruments to microcracking, and 2) to compare measurements of CTB stiffness reduction obtained using the three devices. The test locations included in this study were Redwood Drive and Dale Avenue …

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Fiber Optic Sensor Interrogation Advancements For Research And Industrial Use, Wesley Mont Kunzler Mar 2011

Fiber Optic Sensor Interrogation Advancements For Research And Industrial Use, Wesley Mont Kunzler

Theses and Dissertations

Spectrally-based fiber optic sensors are a rapidly maturing technology capable of sensing several environmental parameters in environments that are unfitting to electrical sensors. However, the sensor interrogation systems for this type of sensors are not yet fit to replace conventional sensor systems. They lack the speed, compact size, and usability necessary to move into mainstream test and measurement. The Fiber Sensor Integrated Monitor (FSIM) technology leverages rapid optical components and parallel hardware architecture to move these sensors across the research threshold into greater mainstream use. By dramatically increasing speed, shrinking size, and targeting an interface that can be used in …

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Development Of Single-Chip Silicon Photonic Microcantilever Arrays For Sensing Applications, Weisheng Hu Mar 2011

Development Of Single-Chip Silicon Photonic Microcantilever Arrays For Sensing Applications, Weisheng Hu

Theses and Dissertations

Microcantilever arrays have been shown to be promising label-free nanomechanical sensing devices with high sensitivity. Two factors that affect the usefulness of microcantilevers in sensing scenarios are the sensitivity of the transduction method for measuring changes in microcantilever properties and the ability to create large compact arrays of microcantilevers. In this dissertation, we demonstrate that microcantilevers with an in-plane photonic transduction method are attractive because they maintain the sensitivity of the traditional laser beam reflection method while being scalable to simultaneous readout of large microcantilever arrays. First I demonstrate the integration of a compact waveguide splitter network with in-plane photonic …

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Calibration Of The Highway Safety Manual Safety Performance Function And Development Of Jurisdiction-Specific Models For Rural Two-Lane Two-Way Roads In Utah, Bradford Keith Brimley Mar 2011

Calibration Of The Highway Safety Manual Safety Performance Function And Development Of Jurisdiction-Specific Models For Rural Two-Lane Two-Way Roads In Utah, Bradford Keith Brimley

Theses and Dissertations

This thesis documents the results of the calibration of the Highway Safety Manual (HSM) safety performance function (SPF) for rural two-lane two-way roadway segments in Utah and the development of new SPFs using negative binomial and hierarchical Bayesian modeling techniques. SPFs estimate the safety of a roadway entity, such as a segment or intersection, in terms of number of crashes. The new SPFs were developed for comparison to the calibrated HSM SPF. This research was performed for the Utah Department of Transportation (UDOT).The study area was the state of Utah. Crash data from 2005-2007 on 157 selected study segments provided …

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Strength And Deformation Characteristics Of A Cement-Treated Reclaimed Pavement With A Chip Seal, Bryan T. Wilson Mar 2011

Strength And Deformation Characteristics Of A Cement-Treated Reclaimed Pavement With A Chip Seal, Bryan T. Wilson

Theses and Dissertations

The objective of this research was to analyze the strength and deformation characteristics of a cement-treated base (CTB) constructed using full-depth reclamation, microcracked, and then surfaced with a single chip seal. In this field study, strength characteristics of the CTB layer were determined at the time of construction, and then both strength and deformation characteristics were evaluated after 9 months of low-volume, heavy truck traffic. After 9 months, observed distresses included transverse cracking, rutting, and chip seal joint failure. The loss of the chip seal was caused by poor chip seal construction practices and not a deficiency in the CTB …

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Increasing Design Productivity For Fpgas Through Ip Reuse And Meta-Data Encapsulation, Adam T. Arnesen Mar 2011

Increasing Design Productivity For Fpgas Through Ip Reuse And Meta-Data Encapsulation, Adam T. Arnesen

Theses and Dissertations

As Moore's law continues to progress, it is becoming increasingly difficult for hardware designers to fully utilize the increasing number of transistors available semiconductor devices including FPGAs. This design productivity gap must be addressed to allow designs to take full advantage of the increased logic density that results from rising transistor density. The reuse of previously developed and verified intellectual property (IP) is one approach that has claimed to narrow the design productivity gap. Reuse, however, has proved difficult to realize in practice because of the complexity of IP and the reluctance of designers to reuse IP that they do …

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Chemical Potential Perturbation: A Method To Predict Chemical Potentials In Periodic Molecular Simulations, Stan G. Moore, Dean R. Wheeler Mar 2011

Chemical Potential Perturbation: A Method To Predict Chemical Potentials In Periodic Molecular Simulations, Stan G. Moore, Dean R. Wheeler

Faculty Publications

A new method, called chemical potential perturbation (CPP), has been developed to predict the chemical potential as a function of density in periodic molecular simulations. The CPP method applies a spatially varying external force field to the simulation, causing the density to depend upon position in the simulation cell. Following equilibration the homogeneous (uniform or bulk) chemical potential as a function of density can be determined relative to some reference state after correcting for the effects of the inhomogeneity of the system. We compare three different methods of approximating this correction. The first method uses the van der Waals density …

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Automatic All-Hex Topology Operations Using Edge Valence Prediction With Application To Localized Coarsening, Timothy Ira Miller Mar 2011

Automatic All-Hex Topology Operations Using Edge Valence Prediction With Application To Localized Coarsening, Timothy Ira Miller

Theses and Dissertations

In this work, we propose using edge valence as a quality predictor when used as a driver for adapting all hexahedral meshes. Edge valence, for hexahedra, is defined as the number of faces attached to an edge. It has shown to be a more reliable quality predictor than node valence for hexahedral meshes. An edge valence of 3, 4, or 5 within the volume of a hexahedral mesh has provided at least a positive scaled Jacobian for all observed meshes, without the presence of over constraining geometry. It is often desirable to adapt an existing mesh through sheet operations such …

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Analysis Of Selected Factors Affecting Concrete Cover Measurements On Bridge Decks, Jeffrey Ryan Hoki Mar 2011

Analysis Of Selected Factors Affecting Concrete Cover Measurements On Bridge Decks, Jeffrey Ryan Hoki

Theses and Dissertations

The objective of this research was to quantify the effects of selected parameters on the accuracy of concrete cover measurements on bridge decks. This research involved three full-factorial laboratory experiments each designed to investigate one of three primary variables. These primary variables included distance to a parallel adjacent bar, distance to a reinforcement intersection, and incorrect bar size input for the cover meter. Each experiment also involved four secondary variables known to affect cover readings. These secondary variables included actual cover depth, meter brand, antenna type, and bar size. Statistical analyses were performed to determine the significance of each factor. …

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Temporal And Spatial Variability In Base Materials Treated With Asphalt Emulsion, Tyler James Quick Mar 2011

Temporal And Spatial Variability In Base Materials Treated With Asphalt Emulsion, Tyler James Quick

Theses and Dissertations

The first objective of this research was to investigate temporal trends in the mechanical properties of base materials stabilized with asphalt emulsion and to assess the rate at which emulsion-treated base (ETB) design properties are achieved. The second objective of this research was to identify construction and environmental factors most correlated to specific mechanical properties of ETB layers and to determine which construction factors exhibit the greatest variability. Additional statistical analysis was performed to determine if significant differences existed between different test sections on a given project. In this research, three experimental sections were established along a pavement reconstruction project …

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A Gis-Based Data Model And Tools For Analysis And Visualization Of Levee Breaching Using The Gssha Model, Hoang Luu Tran Mar 2011

A Gis-Based Data Model And Tools For Analysis And Visualization Of Levee Breaching Using The Gssha Model, Hoang Luu Tran

Theses and Dissertations

Levee breaching is the most frequent and dangerous form of levee failure. A levee breach occurs when floodwater breaks through part of the levee creating an opening for water to flood the protected area. According to National Committee on Levee Safety (NCLS), a reasonable upper limit for damage resulting from levee breaching is around $10 billion per year during 1998 and 2007. This number excludes hurricanes Katrina and Rita in 2005 which resulted in economic damages estimated to be more than $200 billion dollar and a loss of more than 1800 lives. In response to these catastrophic failures, the U.S. …

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A Study Of The Cause Of Failure Of Rotationally Molded, High-Density Polyethylene, Sodium Hypochlorite Storage Tanks, Dixon Harold Abell Mar 2011

A Study Of The Cause Of Failure Of Rotationally Molded, High-Density Polyethylene, Sodium Hypochlorite Storage Tanks, Dixon Harold Abell

Theses and Dissertations

The topic of chemical oxidative degradation in rotational molded polyethylene (high-density cross-linked) chemical (sodium hypochlorite) storage tanks is an industry problem that ranks at the top of current business issues for manufacturers of chemical storage tanks. The degradation of these tanks not only compromises the physical and mechanical properties of the tank material, but reduces the life expectancy of the tank, eventually resulting in catastrophic tank failure. Premature tank failure comes at a hefty cost. The reputation of the manufacturer is questioned often resulting in immediate loss of customer satisfaction and future business. The leaking of the chemical from the …

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Pyrolysis Kinetics And Chemical Structure Considerations Of A Green River Oil Shale And Its Derivatives, James L. Hillier Mar 2011

Pyrolysis Kinetics And Chemical Structure Considerations Of A Green River Oil Shale And Its Derivatives, James L. Hillier

Theses and Dissertations

This work had the objective of determining both the kinetic parameters for the pyrolysis of oil shale and kerogen as well as using analytical techniques coupled with pyrolysis to shed light on the structure of a specific Green River oil shale. Because of the problems with linearized methods and disagreement among literature values and methods, a new method was developed tofit kinetic parameters to non linearized data. The method was demonstrated to determine the "correct" answer for mathematically generated data within a few percent error and was shown to have a lower sum squared error than the linearized methods. The …

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A Proteolytic Process To Simulate The Mechanics Of Disc Dengeration In Bovine Cadaveric Tissue, Timothy A. Bishop Mar 2011

A Proteolytic Process To Simulate The Mechanics Of Disc Dengeration In Bovine Cadaveric Tissue, Timothy A. Bishop

Theses and Dissertations

Purpose. The present work hypothesized that proteolytic dissolution of intervertebral discs could induce biomechanical change comparable to the change observed in natural disc degeneration. A method to do such could be utilized for in vitro research where intersample differences in geometry and chemical makeup render it difficult to compare and aggregate results into generalized conclusions.
Methods. Forty-one bovine coccygeal intervertebral discs were isolated with individual functional spinal units. Samples were loaded in three modes: compression/tension, flexion/extension, and axial rotation. The anulus fibrosus of each disc was injected with 200µl trypsin or fetal bovine serum (control) and incubated for an allotted …

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Developing Methods To Assess The Potential Effects Of Global Climate Change On Deer Creek Reservoir Using Water Quality Modeling, Reed Earl Chilton Mar 2011

Developing Methods To Assess The Potential Effects Of Global Climate Change On Deer Creek Reservoir Using Water Quality Modeling, Reed Earl Chilton

Theses and Dissertations

To evaluate the potential impacts of future climate change on a temperate reservoir, I used a calibrated water quality and hydrodynamic model validated using three years of data (2007-2009) from Deer Creek Reservoir (Utah). I evaluated the changes due to altered air temperatures, inflow rates, and nutrient loads that might occur under Global Climate Change (GCC). I developed methods to study GCC on reservoirs. I produced Average Water Temperature Plots, Stratification Plots, and Total Concentration Plots. Average Water Temperature Plots show the sensitivity of the water temperature to various parameters. Stratification Plots quantify stratification length and strength as well as …

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