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2013

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Articles 3031 - 3060 of 7293

Full-Text Articles in Engineering

Development Of A Pdms Based Micro Total Analysis System For Rapid Biomolecule Detection, Balaji Srinivasan Venkatesh May 2013

Development Of A Pdms Based Micro Total Analysis System For Rapid Biomolecule Detection, Balaji Srinivasan Venkatesh

Graduate Theses and Dissertations

The emerging field of micro total analysis system powered by microfluidics is expected to revolutionize miniaturization and automation for point-of-care-testing systems which require quick, efficient and reproducible results. In the present study, a PDMS based micro total analysis system has been developed for rapid, multi-purpose, impedance based detection of biomolecules. The major components of the micro total analysis system include a micropump, micromixer, magnetic separator and interdigitated electrodes for impedance detection. Three designs of pneumatically actuated PDMS based micropumps were fabricated and tested. Based on the performance test results, one of the micropumps was selected for integration. The experimental results …


Effect Of Deposition From Static Test Fires On Corn And Alfalfa, Scout Mendenhall May 2013

Effect Of Deposition From Static Test Fires On Corn And Alfalfa, Scout Mendenhall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alliant Techsystems, Inc (ATK) manufactures solid rocket motors for the National Aeronautics and Space Administration (NASA) at the Promontory, UT facility. Periodically ATK conducts static test fires, where the rocket is restrained horizontally and fired into a hillside. The plume entrains native soil and is carried by the wind until it cools and settles. Although the area around ATK is sparsely populated, residents of nearby Penrose and Thatcher, UT are concerned with the deposition of the test fire soil (TFS) from the static rocket tests. In 2010, several crop fields nearing harvest were dusted with TFS, prompting the investigation of …


Cognitive Vehicle Platooning In The Era Of Automated Electric Transportation, Pooja Kavathekar May 2013

Cognitive Vehicle Platooning In The Era Of Automated Electric Transportation, Pooja Kavathekar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research focuses on a concept called “cognitive vehicle platooning.” A group of vehicles, either of the same type or different, following one another at highway speeds, coupled together by wireless communication is vehicle platooning. With this technology, passengers can comfortably enjoy their rides without having to drive their cars, as the cars will drive themselves. This automatic car driving is an advanced form of cruise control. These cars will run on dedicated lanes on highways. The leader of the platoon communicates wirelessly to its followers, its position, velocity, and acceleration information. Using this data, the followers will have a …


Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor, Lorin E. Stevens May 2013

Thermo-Piezo-Electro-Mechanical Simulation Of Algan (Aluminum Gallium Nitride) / Gan (Gallium Nitride) High Electron Mobility Transistor, Lorin E. Stevens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to the current public demand of faster, more powerful, and more reliable electronic devices, research is prolific these days in the area of high electron mobility transistor (HEMT) devices. This is because of their usefulness in RF (radio frequency) and microwave power amplifier applications including microwave vacuum tubes, cellular and personal communications services, and widespread broadband access. Although electrical transistor research has been ongoing since its inception in 1947, the transistor itself continues to evolve and improve much in part because of the many driven researchers and scientists throughout the world who are pushing the limits of what modern …


Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson May 2013

Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface water quality in the United States is managed by the U.S. Environmental Protection Agency (EPA) under direction of the Clean Water Act. Designated uses are required for all state waters. Numeric or narrative water quality standards provide measures to determine if each waterbody meets the intended use. Narrative standards typically include vague terminology that is difficult to interpret and this has led EPA to encourage states to develop numeric criteria for nutrients in all its streams, rivers, and lakes. These numeric nutrient criteria are intended to stave off the harmful effects of over-growth of aquatic plants which can result …


Determination Of Ionospheric Current Systems By Measuring The Phase Shift On Amateur Satellite Frequencies, Prajwal M. Kasturi May 2013

Determination Of Ionospheric Current Systems By Measuring The Phase Shift On Amateur Satellite Frequencies, Prajwal M. Kasturi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Linearly polarized electromagnetic waves traveling through cold magnetized plasma experience Faraday rotation. The Appleton Hartree dispersion equation relates the phase shift on any electromagnetic ray to the magnetic field B, ion-electron density Ne and the angle the ray makes with the instantaneous magnetic field. This work uses the dispersion relation to calculate small time scale magnetic perturbations in the ionosphere due to electrojet current systems. The ionosphere is modeled as a collision free cold plasma with synthesized small scale magnetic perturbations. The work presented here simulates test cases, where the satellites transmits three amateur satellite radio band frequencies …


Particle Dynamics And Resistivity Characteristics In Bifurcated Current Sheets, Tushar Andriyas May 2013

Particle Dynamics And Resistivity Characteristics In Bifurcated Current Sheets, Tushar Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Charged particle chaos and its collective effects in different magnetic geometries are investigated in a sequence of various numerical experiments. The fields generated by the particles as a result of interaction with the background electric and magnetic fields is not accounted for in the simulation. An X-line is first used to describe the geometry of the magnetotail prior to magnetic reconnection and a study of the behavior of charged particles is done from a microscopic viewpoint. Another important geometry in the magnetotail prior to substorm onset is Bifurcated Current Sheet. The same analysis is done for this configuration. The existence …


Extracting Atmospheric Profiles From Hyperspectral Data Using Particle Filters, Dustin Rawlings May 2013

Extracting Atmospheric Profiles From Hyperspectral Data Using Particle Filters, Dustin Rawlings

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Removing the effects of the atmosphere from remote sensing data requires accurate knowledge of the physical properties of the atmosphere during the time of measurement. There is a nonlinear relationship that maps atmospheric composition to emitted spectra, but it cannot be easily inverted. Inverting this relationship, however, would allow us to estimate atmospheric parameters by taking hyperspectral measurements of the light emitted from the atmosphere. The particle filter is a method whereby one can estimate a hidden system state based on measurements, without ever having to directly invert the measurement relationship.

Traditionally, particle filters do not perform well in high-dimensional …


Applications Of Bayesian Statistics In Fluvial Bed Load Transport, Mark L. Schmelter May 2013

Applications Of Bayesian Statistics In Fluvial Bed Load Transport, Mark L. Schmelter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The science of fluvial sediment transport studies the processes involved in the movement of river sediments. It is commonly understood that when rivers flood they have a great capacity to move sand, gravel, and even larger cobbles and boulders. This process is not only limited to the big floods that usually attract so much attention, but also the more common river flows play a very important role in forming a river. As engineers and scientists, we like to be able to develop equations and relationships that describe some natural phenomenon—in this case, fluvial sediment transport. While we are able to …


Analysis Of Star Identification Algorithms Due To Uncompensated Spatial Distortion, Steven Paul Brätt May 2013

Analysis Of Star Identification Algorithms Due To Uncompensated Spatial Distortion, Steven Paul Brätt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the evolution of spacecraft systems, we see the growing need for smaller, more affordable, and robust spacecrafts that can be jettisoned with ease and sent to sites to perform a myriad of operations that a larger craft would prohibit, or that can be quickly manipulated from performing one task into another. The developing requirements have led to the creation of Nano-Satellites, or CubeSats. The question then remains, how to navigate the expanse of space with such a minute spacecraft? A solution to this is using the stars themselves as a means of navigation. This can be accomplished by measuring …


Study Of Inkjet Printing As An Ultra-Low-Cost Antenna Prototyping Method And Its Application To Conformal Wraparound Antennas For Sounding Rocket Sub-Payload, Maimaitirebike Maimaiti May 2013

Study Of Inkjet Printing As An Ultra-Low-Cost Antenna Prototyping Method And Its Application To Conformal Wraparound Antennas For Sounding Rocket Sub-Payload, Maimaitirebike Maimaiti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Inkjet printing is a type of computer printing that creates an image by propelling droplets of ink onto paper. It is an attractive patterning technology that has received tremendous interest as a mass fabrication method for a variety of electronic devices due to its manufacturing flexibility and low-cost feature. However, the printing facilities that are being used, especially the inkjet printer, are very expensive. This thesis introduces an extremely cost-friendly inkjet printing method using a printer that costs less than $100. In order to verify its reliability, linearly and circularly polarized planar and conformal microstrip antennas were fabricated using the …


Bahavior And Analysis Of An Integral Abutment Bridge, Conner D. Huffaker May 2013

Bahavior And Analysis Of An Integral Abutment Bridge, Conner D. Huffaker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As a result of abutment spalling on the integral abutment bridge over 400 South Street in Salt Lake City, Utah, the Utah Department of Transportation (UDOT) instigated research measures to better understand the behavior of integral abutment bridges. The bridge was instrumented with survey targets and monitored each month for one year. The monthly surveys were also supplemented by a day-long survey. Measurements of temperature change and span length were obtained and used to show general trends in the movement of the 400 South Street Bridge. A detailed finite-element model was created and results from the model confirmed locations of …


The Contribution Of Magnetospheric Currents To Ground Magnetic Perturbation During Geomagnetic Storms, Swadesh Patra May 2013

The Contribution Of Magnetospheric Currents To Ground Magnetic Perturbation During Geomagnetic Storms, Swadesh Patra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A geomagnetic storm is a disturbance in the earth's space environment in response to a disturbance in the solar wind. The earth's ring current that is a toroidal current flowing roughly in the region also occupied by the Van-Allen radiation belt is energized during a geomagnetic storm. This leads to a decrease in the horizontal component of the geomagnetic field on the earth's surface. The Disturbance Storm Time (Dst) index, which is a measure of the intensity of the ring current, is calculated by taking the average of this decrease in the horizontal intensity across four low latitude …


Using Electromagnetic Induction Sensing To Understand The Dynamics And Interacting Factors Controlling Soil Salinity, Xystus N. Amakor May 2013

Using Electromagnetic Induction Sensing To Understand The Dynamics And Interacting Factors Controlling Soil Salinity, Xystus N. Amakor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

High amounts of salts in soils and a greater tendency of these soils to become even more saline is of great concern in arid and semi-arid western United States. Soils in Cache County, Utah are no exception. Salinization negatively affects the soil, crop, and the quality of groundwater. Thus, the long-term sustainable management of irrigated agricultural lands is threatened.

However, the salinity of these soils are closely monitored and managed to ensure sustainable agricultural productivity. A widely accepted and traditional standard method for estimating soil salinity is by measuring electrical conductivity of saturated paste extracts. Apart from the tedious and …


Development Of The Multiple Use Plug Hybrid For Nanosats (Muphyn) Miniature Thruster, Shannon Dean Eilers May 2013

Development Of The Multiple Use Plug Hybrid For Nanosats (Muphyn) Miniature Thruster, Shannon Dean Eilers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Multiple Use Plug Hybrid for Nanosats (MUPHyN) prototype thruster incorporates solutions to several major challenges that have traditionally limited the deployment of chemical propulsion systems on small spacecraft. The MUPHyN thruster offers several features that are uniquely suited for small satellite applications. These features include 1) a non-explosive ignition system, 2) non-mechanical thrust vectoring using secondary fluid injection on an aerospike nozzle cooled with the oxidizer flow, 3) a non-toxic, chemically-stable combination of liquid and inert solid propellants, 4) a compact form factor enabled by the direct digital manufacture of the inert solid fuel grain. Hybrid rocket motors provide …


Micro-Electro-Mechanical Systems (Mems) Integrated Frequency Reconfigurable Antenna, Abdul Zohur May 2013

Micro-Electro-Mechanical Systems (Mems) Integrated Frequency Reconfigurable Antenna, Abdul Zohur

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis investigates the concept of reconfigurability of an antenna’s properties, such as frequency, radiation pattern, and polarization, for a planar inverted-F antenna (PIFA), by the use of radio frequency micro-electro-mechanical system (RF MEMS) switches. This research work has been conducted at the Micro/Nano Electro Mechanical Systems (µN _eMS) Laboratory at Utah State University. In this thesis, two electrically small frequency reconfigurable antenna designs have been presented with two and three modes of operation with central frequencies of 718 and 4960 MHz and of 857,809 and 4960 MHz, respectively. The maximum frequency tunable ratio achieved in these designs …


The Effects That Non-Recommended Conditions Have On Residential Water Meter Accuracies, Colton F. Smith May 2013

The Effects That Non-Recommended Conditions Have On Residential Water Meter Accuracies, Colton F. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Every year, clean, readily available water becomes more and more scarce. Metering water usage is a way to make users more aware of how much water they use, which in turn will increase the desire to conserve water and to reduce their water bill.

When meters are tested in their new condition, it is normally performed under ideal laboratory conditions at constant flow rates. Then when the meters are installed in the field, they often are installed in or experience non-recommended conditions that are quite different from the ideal laboratory setting. This study investigated several non-recommended conditions that can exist …


Improvement In Computational Fluid Dynamics Through Boundary Verification And Preconditioning, David E. Folkner May 2013

Improvement In Computational Fluid Dynamics Through Boundary Verification And Preconditioning, David E. Folkner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis focuses on improvements to numerical simulation of fluid dynamic problems. A study of computation fluid dynamics is done to improve simulation accuracy and efficiency. Accurate and fast results are the desire of simulation techniques. Two main improvements to current CFD methods are implemented and tested: a new boundary condition verification procedure and a new preconditioning technique.

First, mathematical code verification methods are extended to also include boundary conditions that can often drive fluid dynamics problems. A new framework is created to implement a variety of desirable boundaries. With this framework, a robust verification procedure for these boundaries is …


Predicting The Onset Of Cavitation In Nonsymetric Bifurcations, Steven E. Daniels May 2013

Predicting The Onset Of Cavitation In Nonsymetric Bifurcations, Steven E. Daniels

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many existing dams in the United States were built without hydroelectric generating accessories and are now being considered for hydroelectric installations. A bifurcation is regularly used as the method for diverting the water to the new generators. With a bifurcation installed as part of the new piping system, cavitation could become a problem. Although widely used, there are no published data on cavitation characteristics or head loss coefficients for these bifurcations. Dimensional analysis has not been adequate for experimentally quantifying the cavitation potential and full scale testing is prohibitive for many large geometries. Therefore this study utilized Computational Fluid Dynamics …


Safety Aware Platooning Of Automated Electric Transport Vehicles, Spencer Scott Jackson May 2013

Safety Aware Platooning Of Automated Electric Transport Vehicles, Spencer Scott Jackson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Safety is a paramount concern when considering implementation of an automated highway where computers control the vehicles. Even with computer-fast reaction time there is inevitably some delay and if vehicles do not follow at safe distances, emergency braking maneuvers can cause dangerous collisions. This research investigates situations that might make automated vehicles have dangerous collisions and what standards the system design must hold to keep passengers safe.


Experimental Studies Of Vertical Mixing Patterns In Open Channel Flow Generated By Two Delta Wings Side-By-Side, Garrett Vaughan May 2013

Experimental Studies Of Vertical Mixing Patterns In Open Channel Flow Generated By Two Delta Wings Side-By-Side, Garrett Vaughan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Algae-derived biofuels is a hot topic of research interest when it comes to renewable energy applications. Algae can be grown in open systems that are low-cost, easy to maintain, and open to the environment. However, algae does not grow very dense in these systems. Mixing is an important factor in growing algae. If mixing were to be improved in open systems, the algae may be able to grow more dense. Certain studies show that placing a mechanical device such as an airfoil or airplane wing in the water will be able to increase the capability of mixing in the open …


Computational Fluid Dynamics Validation Of Buoyant Turbulent Flow Heat Transfer, Jared M. Iverson May 2013

Computational Fluid Dynamics Validation Of Buoyant Turbulent Flow Heat Transfer, Jared M. Iverson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Computational fluid dynamics (CFD) is commonly used to visualize and understand complicated fluid flow and heat transfer in many industries. It is imperative to validate the CFD computer models in order to avoid costly design choices where experimentation cannot be used to ratify the predictions of computer models. Assessments of CFD computer models in the literature conclude that significant errors occur in computer model predictions of fluid flow influenced by buoyancy forces.

The Experimental Fluid Dynamics Laboratory at Utah State University constructed a wind tunnel with which to perform experiments on buoyancy induced fluid flow. The experiments measured the heat …


A Quantitative Framework For Assessing Vulnerability And Redundancy Of Freight Transportation Networks, Sarawut Jansuwan May 2013

A Quantitative Framework For Assessing Vulnerability And Redundancy Of Freight Transportation Networks, Sarawut Jansuwan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Freight transportation networks are an important component of everyday life in modern society. Disruption to these networks can make peoples’ daily lives extremely difficult as well as seriously cripple economic productivity. This dissertation develops a quantitative framework for assessing vulnerability and redundancy of freight transportation networks. The framework consists of three major contributions: (1) a two- stage approach for estimating a statewide truck origin-destination (O-D) trip table, (2) a decision support tool for assessing vulnerability of freight transportation networks, and (3) a quantitative approach for measuring redundancy of freight transportation networks.

The dissertation first proposes a two-stage approach to estimate …


Variational Asymptotic Method For Unit Cell Homogenization Of Thermomechanical Behavior Of Composite Materials, Chong Teng May 2013

Variational Asymptotic Method For Unit Cell Homogenization Of Thermomechanical Behavior Of Composite Materials, Chong Teng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To seek better material behaviors, the research of material properties has been massively carried out in both industrial and academic fields throughout the twentieth century. Composite materials are known for their abilities of combining constituent materials in or- der to fulfill the desirable overall material performance. One of the advantages of composite materials is the adjustment between stiffness and lightness of materials in order to meet the needs of various engineering designs. Even though the finite element analysis is mature, composites are heterogeneous in nature and can present difficulties at the structural level with the acceptable computational time. A way …


Verification And Validation Of The Spalart-Allmaras Turbulence Model For Strand Grids, Oisin Tong May 2013

Verification And Validation Of The Spalart-Allmaras Turbulence Model For Strand Grids, Oisin Tong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The strand-Cartesian grid approach is a unique method of generating and computing fluid dynamic simulations. The strand-Cartesian approach provides highly desirable qualities of fully-automatic grid generation and high-order accuracy. This thesis focuses on the implementation of the Spalart-Allmaras turbulence model to the strand-Cartesian grid framework. Verification and validation is required to ensure correct implementation of the turbulence model.

Mathematical code verification is used to ensure correct implementation of new algorithms within the code framework. The Spalart-Allmaras model is verified with the Method of Manufactured Solutions (MMS). MMS shows second-order convergence, which implies that the new algorithms are correctly implemented.

Validation …


Improving Surrogate Monitoring Techniques For Suspended Sediment, Brant R. Whiting May 2013

Improving Surrogate Monitoring Techniques For Suspended Sediment, Brant R. Whiting

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The quality of water of our nation’s rivers and streams is important to many vital uses including drinking water treatment, recreation, and the natural environment. Water quality can be severely impacted by the quantity and type of suspended sediment found therein. Because suspended sediment can be associated with many other contaminants that degrade water quality, it is noted as the most common impairment to water quality in the United States. Suspended sediment can cause significant ecological impacts to the chemical and biological characteristics of surface waters. The ability to accurately quantify suspended sediment concentrations at the appropriate time(s) and location(s) …


Platooning Safety And Capacity In Automated Electric Transportation, James Fishelson May 2013

Platooning Safety And Capacity In Automated Electric Transportation, James Fishelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Automated Electric Transportation (AET) proposes a system of automated platooning vehicles electrically powered by the roadway via wireless inductive power transfer. This has the potential to provide roadway transportation that is less congested, more flexible, cleaner, safer, and faster than the current system. The focus of this research is to show how platooning can be accomplished in a safe manner and what capacities such an automated platooning system can achieve. To accomplish this, first two collision models are developed to show the performance of automated platoons during an emergency braking scenario: a stochastic model coded in Matlab/Simulink and a deterministic …


Most Progress Made Algorithm: Combating Synchronization Induced Performance Loss On Salvaged Chip Multi-Processors, Jacob J. Dutson May 2013

Most Progress Made Algorithm: Combating Synchronization Induced Performance Loss On Salvaged Chip Multi-Processors, Jacob J. Dutson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most modern personal computers come with processors which contain multiple cores. Often, one or more of these cores is damaged during manufacturing. These faults are increasing as manufacturers try to make processors run faster. Many processor designs allow a damaged core to continue working after manufacturing, but these salvaged cores run slower than a fully functional core.

In an attempt to make software run as fast as possible for its users, software designers write applications that are split into multiple parts called threads. These threads can be run on separate cores at the same time and get more work done …


Spin Stability Of Sounding Rocket Secondary Payloads Following High Velocity Ejections, Weston Mcclain Nelson May 2013

Spin Stability Of Sounding Rocket Secondary Payloads Following High Velocity Ejections, Weston Mcclain Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Auroral Spatial Structures Probe (ASSP) mission is a sounding rocket mission studying the effects of solar energy on space weather. ASSP requires the high speed ejection (up to 50 m/s) of 6 secondary payloads to gather the required data. The scientific instruments on the secondary payloads require that the payloads are stable in flight with coning angles of less than 5º, where the coning angle is the amount the payload is allowed to “wobble” about its spin axis. The secondary payloads are also required to have their spin axes aligned with 25º of the local magnetic field lines. Current …


Modeling Overlapping And Heterogeneous Perception Variance In Stochastic User Equilibrium Problem With Weibit Route Choice Model, Songyot Kitthamkesorn May 2013

Modeling Overlapping And Heterogeneous Perception Variance In Stochastic User Equilibrium Problem With Weibit Route Choice Model, Songyot Kitthamkesorn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Traffic assignment problem is an important component of the transportation planning model. State-of-the-practice traffic assignment models adopt the equilibrium principle to equilibrate the travel demand with the travel supply (e.g., highway and transit networks) under congestion. These models give the transportation network performance measures to compare among transportation alternatives for supporting the decision-making processes. The deterministic user equilibrium (DUE) principle is perhaps the most widely used in the traffic assignment problem. In this principle, all travelers are assumed to minimize their individual travel cost, such that only the lowest-cost route is used at equilibrium. However, this perfect knowledge assumption is …