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Full-Text Articles in Engineering

Construction, Analysis, And Data-Driven Augmentation Of Supersaturated Designs, Alex J. Gutman Sep 2013

Construction, Analysis, And Data-Driven Augmentation Of Supersaturated Designs, Alex J. Gutman

Theses and Dissertations

Screening designs are used in the early stages of industrial and computer experiments to find the most important input factors affecting a system's output. They provide an economical way to remove unimportant factors from further, potentially costly, experimentation. However, when an experiment has a large number of control factors and limited number of available runs, it is infeasible to run a traditional screening design. In these situations, experimenters can use supersaturated designs. A supersaturated design is a fractional factorial design that can screen a set of k factors in n runs, where k is greater than n -1. Unfortunately, they …

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The Influence Of Superhydrophobicity On Laminar Jet Impingement And Turbulent Flow In A Channel With Walls Exhibiting Riblets, Joseph Fletcher Prince Aug 2013

The Influence Of Superhydrophobicity On Laminar Jet Impingement And Turbulent Flow In A Channel With Walls Exhibiting Riblets, Joseph Fletcher Prince

Theses and Dissertations

The object of this work is to explore the influence superhydrophobic (SH) surfaces exert in laminar jet impingement and when they are combined with riblets in turbulent channel flow. A SH surface generates an apparent slip due to the combination of micropatterning and chemical hydrophobicity. Because of surface tension, water does not enter the cavities between the features, increasing the contact angle of a water droplet on the surface and reducing the liquid-solid contact area. An analysis based on the integral momentum approach of Karman and Pohlhausen is presented that predicts jet impingement behavior on SH surfaces. The model is …

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Synthetic Polymeric Carbohydrates Recognized Toxoplasma Gondii Tachyzoites And Induced Early Phagocytosis By Macrophages, Souzan Hussain Eassa Aug 2013

Synthetic Polymeric Carbohydrates Recognized Toxoplasma Gondii Tachyzoites And Induced Early Phagocytosis By Macrophages, Souzan Hussain Eassa

Theses and Dissertations

Toxoplasmosis is a parasitic disease caused by the intracellular protozoan Toxoplasma gondii your words (T. gondii your words) that affects most types of warm-blooded vertebrate cells. Up to one third of the humans population in the world is chronically infected by this parasite. Human and animals at risk for toxoplasmosis include fetuses, newborns, and immunologically impaired patients. To date, there is no vaccine available and no drug has a successful effective against chronic form of toxoplasmosis. Recent Toxoplasma your words diagnostic methods showed high false positive results and cannot detect the parasite in the early infection stage. Early diagnosis of …

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Thermal Transport To Sessile Water Droplets On Heated Superhydrophobic Surfaces Of Varying Cavity Fraction, Robb C. Hays Aug 2013

Thermal Transport To Sessile Water Droplets On Heated Superhydrophobic Surfaces Of Varying Cavity Fraction, Robb C. Hays

Theses and Dissertations

The hydrophobicity of a surface is defined as the degree to which it repels water molecules, and the internal contact angle that the droplet makes with the surface is a measure of the hydrophobicity. Contact angles less than 90° occur on hydrophilic surfaces, while contact angles greater than 90° occur on hydrophobic surfaces. If a surface's contact angle is greater than 120° the surface is commonly defined as superhydrophobic (SH). Superhydrophobicity is accomplished through a combination of microscale surface roughness and water repellant surface chemistry. The roughness creates cavities, or pockets, of vapor underneath the droplet which act to increase …

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Development Of The In Vivo Multicolor Photoacoustic Flow Cytometer, Mustafa Sarimollaoglu Aug 2013

Development Of The In Vivo Multicolor Photoacoustic Flow Cytometer, Mustafa Sarimollaoglu

Theses and Dissertations

Flow cytometry is a powerful tool for analysis of cells in artificial flow. This highly accurate technology, using multicolor fluorescent probes and lasers with different wavelengths, provides fast multiparameter quantification of the biological properties of cells. Invasive extraction of cells from an organism, however, leads to changes in cell properties and low sensitivity, and prevents studying cells in their native environment. Challenges to advances in in vivo flow cytometry include fluorescent probe toxicity, strong background, and number of colors, as well as assessment of small vessels. To overcome these limitations, photoacoustic flow cytometry (PAFC) was introduced. PAFC is based on …

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Particle Morphology And Elemental Composition Of Heavy Fuel Oil Ash At Varying Atomization Pressures, Daniel Abraham Tovar Aug 2013

Particle Morphology And Elemental Composition Of Heavy Fuel Oil Ash At Varying Atomization Pressures, Daniel Abraham Tovar

Theses and Dissertations

Land-based turbine engines are currently used to burn heavy fuel oil (HFO), which is a lower cost fuel. HFO contains inorganic material that forms deposits on turbine blades reducing output and efficiency. Magnesium based additives are used to inhibit vanadium pentoxide deposition and reduce the corrosive nature of the gas and deposits in the hot gas path of the gas turbine. The focus of this study was to determine particle morphology and elemental composition of ash when firing HFO in an atmospheric combustor at various fuel injector atomization pressures. Prior to firing, the HFO was washed with water to remove …

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A New Approach To Harmonic Elimination Based On A Real-Time Comparison Method, Sri Nikhil Gupta Gourisetti Aug 2013

A New Approach To Harmonic Elimination Based On A Real-Time Comparison Method, Sri Nikhil Gupta Gourisetti

Theses and Dissertations

Undesired harmonics are responsible for noise in a transmission channel, power loss in power electronics and in motor control. Selective Harmonic Elimination (SHE) is a well-known method used to eliminate or suppress the unwanted harmonics between the fundamental and the carrier frequency harmonic/component. But SHE bears the disadvantage of its incapability to use in real-time applications. A novel reference-carrier comparative method has been developed which can be used to generate an SPWM signal to apply in real-time systems. A modified carrier signal is designed and tested for different carrier frequencies based on the generated SPWM FFT. The carrier signal may …

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Vision-Based Guidance For Air-To-Air Tracking And Rendezvous Of Unmanned Aircraft Systems, Joseph Walter Nichols Aug 2013

Vision-Based Guidance For Air-To-Air Tracking And Rendezvous Of Unmanned Aircraft Systems, Joseph Walter Nichols

Theses and Dissertations

This dissertation develops the visual pursuit method for air-to-air tracking and rendezvous of unmanned aircraft systems. It also shows the development of vector-field and proportional-integral methods for controlling UAS flight in formation with other aircraft. The visual pursuit method is a nonlinear guidance method that uses vision-based line of sight angles as inputs to the algorithm that produces pitch rate, bank angle and airspeed commands for the autopilot to use in aircraft control. The method is shown to be convergent about the center of the camera image frame and to be stable in the sense of Lyapunov. In the lateral …

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Computational Model Of Pitting Corrosion, Muhammad Ibrahim Israr Bin Aug 2013

Computational Model Of Pitting Corrosion, Muhammad Ibrahim Israr Bin

Theses and Dissertations

Pitting corrosion is a form of highly localized corrosion that can lead to crack and failure of a structure. Study on pitting corrosion is necessary in order to predict and prevent the risk of failure of structure susceptible to corrosion. In this thesis, a combination of Cellular Automata (CA) and Boundary Element Method (BEM) was developed to simulate pitting corrosion growth under certain environment. It is assumed that pitting corrosion can be simplified to electrochemical corrosion cell. The distribution of potential around this corrosion cell can then be simulated by BEM. This distribution potential represents cathodic and anodic reactions around …

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The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter Aug 2013

The Design And Development Of A Perceptual-Based Haptic Display Device, Sohaib Akhter

Theses and Dissertations

Graphical information presented as pictures, graphs, maps, and the like are an important media for relaying knowledge and are a fundamental means of education rarely experienced by people who are blind or have a severe visual impairment. This thesis presents the design, development and testing of a multiple finger, haptic matrix dynamic display device capable of relaying graphical information through simulated textures. The design is based on user perception studies that determined which hand constraints provided the best tradeoff between simplicity of design, accuracy and time to answer. The best design was one that incorporated multiple fingers in close proximity …

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Development Of A Sense And Avoid System For Small Unmanned Aircraft Systems, Robert Andrew Klaus Aug 2013

Development Of A Sense And Avoid System For Small Unmanned Aircraft Systems, Robert Andrew Klaus

Theses and Dissertations

Unmanned aircraft systems (UAS) represent the future of modern aviation. Over the past 10 years their use abroad by the military has become commonplace for surveillance and combat. Unfortunately, their use at home has been far more restrictive. Due to safety and regulatory concerns, UAS are prohibited from flying in the National Airspace System without special authorization from the FAA. One main reason for this is the lack of an on-board pilot to "see and avoid" other air traffic and thereby maintain the safety of the skies. Development of a comparable capability, known as "Sense and Avoid" (SAA), has therefore …

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Smart Superhydrophobic Materials, Adetoun Taiwo Aug 2013

Smart Superhydrophobic Materials, Adetoun Taiwo

Theses and Dissertations

Superhydrophobicity refers to surfaces with extremely large water droplet contact angles (usually greater than 150°). This phenomenon requires a hydrophobic material with micro or nano-scale roughness. Superhydrophobic surfaces exist in nature (e.g. the lotus leaf) and can be produced synthetically. This project focuses on the development and characterization of superhydrophobic materials with tunable wettability (i.e. smart superhydrophobic materials). In this study, surfaces were prepared by electrospinning thin, aligned polystyrene fibers onto a piezoelectric unimorph substrate. Results showed electric field induced changes in substrate curvature, which produced corresponding changes in surface wettability. From experiments, an average change in water contact angle …

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Real-Time Visualization Of Finite Element Models Using Surrogate Modeling Methods, Ryan C. Heap Aug 2013

Real-Time Visualization Of Finite Element Models Using Surrogate Modeling Methods, Ryan C. Heap

Theses and Dissertations

Finite element analysis (FEA) software is used to obtain linear and non-linear solutions to one, two, and three-dimensional (3-D) geometric problems that will see a particular load and constraint case when put into service. Parametric FEA models are commonly used in iterative design processes in order to obtain an optimum model given a set of loads, constraints, objectives, and design parameters to vary. In some instances it is desirable for a designer to obtain some intuition about how changes in design parameters can affect the FEA solution of interest, before simply sending the model through the optimization loop. This could …

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A Kalman Filter Based Attitude Heading Reference System Using A Low Cost Inertial Measurement Unit, Matthew Leccadito Jul 2013

A Kalman Filter Based Attitude Heading Reference System Using A Low Cost Inertial Measurement Unit, Matthew Leccadito

Theses and Dissertations

This paper describes, the development of a sensor fusion algorithm-based Kalman lter ar- chitecture, in combination with a low cost Inertial Measurement Unit (IMU) for an Attitude Heading Reference System (AHRS). A low cost IMU takes advantage of the use of MEMS technology enabling cheap, compact, low grade sensors. The use of low cost IMUs is primar- ily targeted towards Unmanned Aerial Vehicle (UAV) applications due to the requirements for small package size, light weight, and low energy consumption. The high dynamics nature of smaller airframes, coupled with the typical vibration induced noise of UAVs require an e cient, reliable, …

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Spatial And Temporal Estimation Of Nanomechanical Properties Via Atomic Force Microscopy, Eric Mccullough Jul 2013

Spatial And Temporal Estimation Of Nanomechanical Properties Via Atomic Force Microscopy, Eric Mccullough

Theses and Dissertations

Engineering the next generation of smart materials will require new methods of surface characterization, analysis and identification that can be performed not only in three dimensional space but also in the temporal dimension. Of particular interest is the understanding of mechanical properties of complex systems at the micro and nanoscales. Current techniques for such measurements are hampered by challenges including their inability to probe systems in complex microenvironments, non-destructively, or at nanometer resolution. This thesis outlines work in the development of techniques to study diverse systems and determine their mechanical properties using the Atomic Force Microscope as the primary tool. …

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The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov Jul 2013

The Effect Of Concurrent Cognitive-Visuomotor Multitasking And Task Difficulty On Dynamic Functional Connectivity In The Brain, Plamen Nikolov

Theses and Dissertations

This thesis investigated the effect of visuomotor and working memory 1) task difficulty and 2) multitasking on dynamic functional connectivity in the brain. Studies have only recently begun to investigate functional connectivity within the scope of concurrent dual task or varying task difficulty conditions (Cocchi, Zalesky, et al. 2011; Rietschel et al. 2012). A series of EEG recordings were conducted during execution of visuomotor or working memory tasks within a novel paradigm using BCI2VR custom MATLAB toolbox. Functional connectivity was correlated with task-related coherence (TRCoh) analysis between two task conditions involving either variation in task difficulty or concurrent execution during …

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Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu Jul 2013

Semi-Interpenetrating Network Gelatin Fiber Sca Old For Oral Mucosal Delivery Of Insulin, Leyuan Xu

Theses and Dissertations

Common therapy for diabetes mellitus is subcutaneous administration of insulin that is subject to serious disadvantages, such as patient noncompliance and occasional hypoglycemia. Hence, oral administration of insulin could be more convenient and serve as a desired route. However, oral administration of insulin is severely limited by the low bioavailability of insulin through the gastrointestinal tract. In this study, a semi-interpenetrating network gelatin fiber scaffold (sIPN GF) was fabricated for oral mucosal delivery of insulin as an alternative route. This sIPN GF was engineered from an electrospun gelatin fiber scaffold (GF), which was further crosslinked with polyethylene glycol diacrylate (PEG-DA) …

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Multifunctional Orthogonally-Frequency-Coded Saw Strain Sensor, William Wilson Jul 2013

Multifunctional Orthogonally-Frequency-Coded Saw Strain Sensor, William Wilson

Theses and Dissertations

A multifunctional strain sensor based on Surface Acoustic Wave (SAW) Orthogonal Frequency Coding (OFC) technology on a Langasite substrate has been investigated. Second order transmission matrix models have been developed and verified. A new parameterizable library of SAW components was created to automate the layout process. Using these new tools, a SAW strain sensor with OFC reflectors was designed, fabricated and tested. The Langasite coefficients of velocity for strain (γS = 1.699) and Temperature (γT = 2.562) were experimentally determined. The strain and temperature characterization of this strain sensor, along with the coefficients of velocity, have been used to demonstrate …

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Internal Curing Of Concrete Bridge Decks In Utah: Mountain View Corridor Project, Joseph Michael Yaede Jul 2013

Internal Curing Of Concrete Bridge Decks In Utah: Mountain View Corridor Project, Joseph Michael Yaede

Theses and Dissertations

The objectives of this research were to 1) monitor in-situ moisture and diffusivity for both conventional concrete and concrete containing pre-wetted lightweight fine aggregate (LWFA), 2) compare deck performance in terms of early-age cracking, compressive strength, and chloride ingress, and 3) compare concrete properties in terms of compressive strength, chloride permeability, elastic modulus, and water content in the laboratory using cylinders cast in the field at the time of deck construction. The research involved field and laboratory evaluations of four newly constructed bridge decks located in northern Utah, two constructed using conventional concrete and two constructed using pre-wetted LWFA to …

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The Effect Of Cooling Rate Of Friction Stir Welded High Strength Low Alloy Steel, Scott Anthony Rose Jul 2013

The Effect Of Cooling Rate Of Friction Stir Welded High Strength Low Alloy Steel, Scott Anthony Rose

Theses and Dissertations

The friction stir welding of steel has produced a hard zone in several different alloys. Despite its detrimental effects on weld toughness, the reasons behind neither its formation nor a method of reducing its size or effects have been explored. Recent advances in process control allow for direct heat input control, which combined with the use of backing plates of different thermal conductivity allows for an expansion of the process window. These control methods also affect the HAZ cooling rate by providing greater range (a 60% increase compared to a fixed backing plate) and control (five welds within 16 °C/s). …

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Popup Height And The Dynamics Of Rising Buoyant Spheres, Randy H. Munns Jul 2013

Popup Height And The Dynamics Of Rising Buoyant Spheres, Randy H. Munns

Theses and Dissertations

In this paper the popup height of rising buoyant spheres is studied over a range of distinct release depths along with the accompanying velocities and accelerations near the free surface. In the past, regimes of motion due to vortex induced vibrations have been classified based on trajectories below the free surface. This study focuses on the popup height, velocity and acceleration at free surface exit, and vortex shedding in order to further define regimes of motion experienced by a rising buoyant sphere. Varying the release depth below the free surface reveals varying exit angles, velocities, accelerations, and popup heights at …

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A Comparative Analysis Of Energy Modelingmethods For Commercial Buildings, Spencer Mark Salmon Jul 2013

A Comparative Analysis Of Energy Modelingmethods For Commercial Buildings, Spencer Mark Salmon

Theses and Dissertations

This thesis researched the accuracy of measured energy data in comparison to estimated hand calculation data and estimated building energy performance simulation data. In the facility management industry, there is minimal evidence that building energy performance software is being used as a benchmark against measured energy usage within a building. Research was conducted to find examples of measured energy data compared to simulated data. The study examined the accuracy of a simulation software and hand calculations to measured energy data. Data suggests that comparisons may be made between building energy performance simulated data and measured data, though comparisons are solely …

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Improvements In Diffusion Weighted Imaging Through A Composite Body And Insert Gradient Coil System, Peter Austin Jepsen Jul 2013

Improvements In Diffusion Weighted Imaging Through A Composite Body And Insert Gradient Coil System, Peter Austin Jepsen

Theses and Dissertations

Diffusion Magnetic Resonance Imaging (DMRI) is a class of Magnetic Resonance Imaging (MRI) techniques with broad medical applications ranging from characterization of tumors and brain damage to potential prediction of stroke. Gradient coil and signal-to- noise ratio (SNR) constraints limit spatial resolution, accuracy, and scan time in DMRI. Achieving high b-values (measures of a scan's sensitivity to diffusion) often require scans with long diffusion gradient pulses, leading to significant magnetic resonance (MR) signal decay before the signal can be sampled. This signal loss reduces the accuracy of diffusion parameter estimation. The ability to sample the MR signal sooner while maintaining …

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Gesture Analysis For Human-Computer Interface Using Profile-Matching Stereo Vision, Yung Ping Chang Jul 2013

Gesture Analysis For Human-Computer Interface Using Profile-Matching Stereo Vision, Yung Ping Chang

Theses and Dissertations

This thesis presents a novel profile shape matching stereo vision algorithm. This algorithm is able to obtain 3D information in real time from a pair of stereo images. This algorithm produces the 3D information by matching the profile intensity shapes on the same row of the two images from a stereo image pair. The advantage of this profile shape matching algorithm is that the detection of correspondences relies on intensity profile shape not on intensity values, which subject to lighting variations. The user can choose an interval of disparity, and then an object in a desired distance range can be …

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Variable Fidelity Optimization With Hardware-In-The-Loop For Flapping Flight, Michael Luke Duffield Jul 2013

Variable Fidelity Optimization With Hardware-In-The-Loop For Flapping Flight, Michael Luke Duffield

Theses and Dissertations

Hardware-in-the-loop (HIL) modeling is a powerful way of modeling complicated systems. However, some hardware is expensive to use in terms of time or mechanical wear. In cases like these, optimizing using the hardware can be prohibitively expensive because of the number of calls to the hardware that are needed. Variable fidelity optimization can help overcome these problems. Variable fidelity optimization uses less expensive surrogates to optimize an expensive system while calling it fewer times. The surrogates are usually created from performing a design of experiments on the expensive model and fitting a surface to the results. However, some systems are …

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Modeling And Optimization Of Space Use And Transportation For A 3d Walkable City, Bradley R. Mecham Jul 2013

Modeling And Optimization Of Space Use And Transportation For A 3d Walkable City, Bradley R. Mecham

Theses and Dissertations

This thesis presents an investigation of a new three-dimensional urban form where walking distances are less than a half-mile and congestion is minimal. The car-free urban form investigated herein is a city composed of skyscrapers massively interconnected with skybridges at multiple levels. The investigation consists of optimizing space use arrangement, skybridge presence or absence, and elevator number to simultaneously minimize total travel time, skybridge light blockage, and elevator energy usage in the city. These objectives are evaluated using three objective functions, the most significant of which involves a three-dimensional, pedestrian-only, three-step version of the traditional four-step planning model. Optimal and …

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The Sustainability Of Lean Manufacturing As A Competitive Advantage, Louis G. Jones Jul 2013

The Sustainability Of Lean Manufacturing As A Competitive Advantage, Louis G. Jones

Theses and Dissertations

Since the early 1990s lean manufacturing has been employed by companies looking to reduce costs, increase efficiencies and improve quality. Academic studies of the financial benefits of lean manufacturing are mixed in their results, where some show benefit and others do not. The objective of the current work was to confirm a financial benefit of lean manufacturing, while also establishing whether such a financial advantage was sustainable. Financial data was collected for a large number of companies in the manufacturing sector, over the period from 1990 to 2010. The data were used to show correlation between inventory turns and return …

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Large-Scale Testing Of Passive Force Behavior For Skewed Abutments With High Width-Height Ratios, Katie Noel Palmer Jul 2013

Large-Scale Testing Of Passive Force Behavior For Skewed Abutments With High Width-Height Ratios, Katie Noel Palmer

Theses and Dissertations

The effects of seismic forces and thermal expansion on bridge performance necessitate an accurate understanding of the relationship between passive force and backwall deflection. In past case studies, skewed bridges exhibited significantly more damage than non-skewed bridges. These findings prompted studies involving numerical modeling, lab-scale tests, and large-scale tests that each showed a dramatic reduction in passive force with increased skew. Using these results, a correlation was developed between peak passive force and backwall skew angle. The majority of these tests had length to height ratios of 2.0; however, for several abutments in the field, the length to height ratio …

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An Analysis Of The Provo River Decree And Its Current Application To Provo Area Water Rights, Karsten Eugene Busby Jul 2013

An Analysis Of The Provo River Decree And Its Current Application To Provo Area Water Rights, Karsten Eugene Busby

Theses and Dissertations

Water scarcity in the west has created a long history of conflict. When Utah was settled, laws were instituted (both officially and otherwise) that allowed water users to use streams and springs in efficient ways without causing harm to other users. The Provo River Decree is a physical example of local water law that has been in place for almost a hundred years. While many changes have arisen in its area of jurisdiction, it is still drawn upon to determine water rights. Ambiguity, rigidity, and overall changes to use patterns have limited the application of the decree to present situations. …

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The Water Entry Of Slender Axisymmetric Bodies: Forces, Trajectories And Acoustics, Kyle Gordon Bodily Jul 2013

The Water Entry Of Slender Axisymmetric Bodies: Forces, Trajectories And Acoustics, Kyle Gordon Bodily

Theses and Dissertations

Free surface water entry of various objects has been studied using high-speed images and image processing techniques for decades. This thesis studies the forces, velocities, and trajectories of slender axisymmetric projectiles using an embedded inertial measurement unit (IMU). Three nose shapes (cone, ogive, and flat) were used in the study. Additionally, the projectiles were tested at vertical and oblique impact angles with different surface conditions. One-half of each projectile was coated down the centerline with a hydrophobic spray, creating a half hydrophobic, half hydrophilic case. The trajectory of this half-and-half case impacting vertically was compared to the trajectory of symmetrically …

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