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Articles 1 - 30 of 138
Full-Text Articles in Engineering
A Dynamic Optimization Framework With Model Predictive Control Elements For Long Term Planning Of Capacity Investments In A District Energy System, Jose Luis Mojica Velazquez
A Dynamic Optimization Framework With Model Predictive Control Elements For Long Term Planning Of Capacity Investments In A District Energy System, Jose Luis Mojica Velazquez
Theses and Dissertations
The capacity expansion of a district heating system is studied with the objective of evaluating the investment decision timing and type of capacity expansion. District energy is an energy generation system that provides energy, such as heat and electricity, generated at central locations and distributed to the surrounding area. The study develops an optimization framework to find the optimal investment schedule over a 30 year horizon with the options of investing in traditional heating sources (boilers) or a next-generation combined heat and power (CHP) plant that can provide heat and electricity. In district energy systems, the investment decision on the …
Water Vapor Movement In Freezing Aggregate Base Materials, Maile Anne Rogers
Water Vapor Movement In Freezing Aggregate Base Materials, Maile Anne Rogers
Theses and Dissertations
The objectives of this research were to 1) measure the extent to which water vapor movement results in water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement in freezing base materials; 3) determine if the corresponding changes in water content are sufficient to cause frost heave during winter; 4) determine if the corresponding changes in water content are sufficient to cause reductions in stiffness during spring; 5) evaluate relationships between selected material properties, freezing conditions, and the occurrence and impact of water vapor movement; and 6) numerically simulate heat and water movement …
Frost Susceptibility Of Base Materials Treated With Asphalt Emulsion, Noelle Anderson
Frost Susceptibility Of Base Materials Treated With Asphalt Emulsion, Noelle Anderson
Theses and Dissertations
The objective of this research was to investigate emulsion-treated base (ETB) frost susceptibility in terms of both freeze-thaw cycling and frost heave. The research performed in this study involved laboratory testing of ETB materials sampled from both the Redwood Road and 7800 South reconstruction projects in northern Utah. The effects of freeze-thaw cycling were evaluated by comparing the stiffness and strength of tested specimens to the same properties of control specimens not subjected to freeze-thaw cycling. Frost heave testing enabled evaluation of the effects of emulsion content and degree of curing on the volumetric stability of ETB materials during sustained …
Developing Guidelines For Including Mobility-Based Performance Specifications In Highway Construction Contracts, Shawn J. Larson
Developing Guidelines For Including Mobility-Based Performance Specifications In Highway Construction Contracts, Shawn J. Larson
Theses and Dissertations
Construction zones can greatly affect the traffic flow on roadways, especially when lane closures are required. Traditionally, the Utah Department of Transportation (UDOT) has used traffic management specifications that only allow lane closures and road work to be done during predetermined hours or specifications that require a certain number of lanes to be open at all times. Recently, mobility-based work-zone traffic flow maintenance has been considered. This method requires continuous monitoring of mobility-based performance data and a mechanism to send alerts to the contractors when the mobility data does not meet the standards set by the specifications. UDOT recently tested …
A Kinetic Study Of Aqueous Calcium Carbonate, Derek Daniel Harris
A Kinetic Study Of Aqueous Calcium Carbonate, Derek Daniel Harris
Theses and Dissertations
Amorphous calcium carbonate (ACC) precipitation is modeled using particle nucleation, growth, and aggregation. The particles are tracked in terms of their radial size and particle density using direct quadrature method of moments (DQMOM). Four separate nucleation models are implemented and are compared to experimental data. In discord with a recent study, it is shown that classical nucleation, coupled with equilibrium chemistry, is in good agreement with experimental data. Novel nucleation mechanisms are presented which fit the experimental data with slightly greater accuracy. Using equilibrium chemistry it is shown that the equilibrium value of ACC is pKeq = 7.74 at 24C, …
Condition Assessment Of Decommissioned Bridge Decks Treated With Waterproofing Membranes And Asphalt Overlays, Eric Scott Sumsion
Condition Assessment Of Decommissioned Bridge Decks Treated With Waterproofing Membranes And Asphalt Overlays, Eric Scott Sumsion
Theses and Dissertations
The objective of this research was to assess the condition of four decommissioned bridge decks treated with waterproofing membranes and asphalt overlays following the completion of their service lives. Large samples were cut from each of the bridge decks immediately prior to demolition and taken to the Brigham Young University Highway Materials Laboratory, where extensive sampling and testing was performed. Methods used to evaluate the condition of the bridge deck samples included visual inspection, hammer sounding, Schmidt rebound hammer testing, resistivity testing, half-cell potential testing, linear polarization testing, cover depth measurement, and chloride concentration measurement. The samples were removed from …
Liquid Core Waveguide Sensors With Single And Multi-Spot Excitation, Lynnell Uilani Wai Yee Zempoaltecatl
Liquid Core Waveguide Sensors With Single And Multi-Spot Excitation, Lynnell Uilani Wai Yee Zempoaltecatl
Theses and Dissertations
Using silicon based microfabrication and materials, a photonic platform, capable of single bioparticle analysis, has been developed. This platform combines liquid and hollow core waveguides on the micron-scale (5 µm x 12 µm) to isolate femtoliter sized sample volumes. Fluorescence excitation and signals in the visible range are directed into and out of the sample volume at an orthogonal angle to maximize signal-to-noise. In order to guide light in a low-index material antiresonant reflecting optical waveguides (ARROWs) were incorporated into the platform. This thesis reveals the development path of these structures over several device generations including innovations in material, geometries, …
Automatic Modulation Recognition For Aeronautical Telemetry, Jacob William Frogget
Automatic Modulation Recognition For Aeronautical Telemetry, Jacob William Frogget
Theses and Dissertations
This these explores automatic modulation recognition as applied to PCM/FM, SOQPSK- TG and ARTM CPM. It found that the likelihood based approach is intractable. The statistical features of the amplitude, phase and frequency are ineffective at distinguishing these modulation types. A method based on the phase changes between symbols is developed and shows that as long as symbol timing is established, this method can effectively distinguish PCM/FM, SOQPSK-TG and ARTM CPM for signal-to-noise ratios above 30 dB. Another method, the Bianchi-Loubaton- Sirven technique, was able to distinguish PCM/FM and SOQPSK-TG but was unable to distinguish ARTM CPM. A happy byproduct …
Delamination Detection In Concrete Using Disposable Impactors For Excitation, Anjali Narendra Patil
Delamination Detection In Concrete Using Disposable Impactors For Excitation, Anjali Narendra Patil
Theses and Dissertations
Delaminations in concrete bridge decks result primarily from corrosion of the reinforcing bars (or rebar). This corrosion leads to volumetric expansion of the rebar. When the rebar expands, concrete cracks, and there is a localized separation of the concrete cover from the underlying concrete. Impact-echo testing is an effective technique to map delaminations on concrete bridge decks. However, mapping speed is limited by necessary retrieval of the impactor for traditional tests. To achieve higher scanning speeds, it is advantageous to use both a non-contact measurement (air-coupled impact-echo) and disposable-impactor excitation. Disposable impactors have the potential advantage of achieving greater deck …
Effect Of Full-Annular Pressure Pulses On Axial Turbine Performance, Mark H. Fernelius
Effect Of Full-Annular Pressure Pulses On Axial Turbine Performance, Mark H. Fernelius
Theses and Dissertations
Pulse detonation engines show potential to increase the efficiency of conventional gas turbine engines if used in place of the steady combustor. However, since the interaction of pressure pulses with the turbine is not yet well understood, a rig was built to compare steady flow with pulsing flow. Compressed air is used in place of combustion gases and pressure pulses are created by rotating a ball valve with a motor. This work accomplishes two main objectives that are different from previous research in this area. First, steady flow through an axial turbine is compared with full annular pulsed flow closely …
An Experimental Analysis Of The Weighted Sum Of Spatial Gradients Minimization Quantity In Active Structural Acoustic Control Of Vibrating Plates, Daniel R. Hendricks
An Experimental Analysis Of The Weighted Sum Of Spatial Gradients Minimization Quantity In Active Structural Acoustic Control Of Vibrating Plates, Daniel R. Hendricks
Theses and Dissertations
Active Structural Acoustic Control (ASAC) is a subcategory of the more widely known field of Active Noise control (ANC). ASAC is different from traditional ANC methods because it seeks to attenuate noise by altering the noise producing structure instead of altering the acoustic waves traveling through the air. The greatest challenge currently facing ASAC researchers is that a suitable parameter has not yet been discovered which can be easily implemented as the minimization quantity in the control algorithms. Many parameters have been tried but none effectively attenuate the sound radiation in a way that can be easily implemented. A new …
The Performance Of Risk Management And Innovation In Construction Manager/General Contractor Delivery In Civil Construction Applications, Rebecca M. Owens
The Performance Of Risk Management And Innovation In Construction Manager/General Contractor Delivery In Civil Construction Applications, Rebecca M. Owens
Theses and Dissertations
Project teams that deliver high risk, complex projects in the civil construction industry need tools to enable successful delivery. Construction Manager/General Contractor (CM/GC) is an innovative alternate delivery method, providing one such a tool. CM/GC furnishes public agencies with an attractive option for delivering projects in a less adversarial and more constructive manner by involving the contractor during design. The sophisticated public owner does not have to relinquish control of the details of the design in order to accelerate the schedule or see the benefits of real-time cost estimating data. There are also significant cost and schedule benefits with not …
Active Structural Acoustic Control Of Clamped And Ribbed Plates, William Richard Johnson
Active Structural Acoustic Control Of Clamped And Ribbed Plates, William Richard Johnson
Theses and Dissertations
A control metric, the weighted sum of spatial gradients (WSSG), has been developed for use in active structural acoustic control (ASAC). Previous development of WSSG [1] showed that it was an effective control metric on simply supported plates, while being simpler to measure than other control metrics, such as volume velocity. The purpose of the current work is to demonstrate that the previous research can be generalized to plates with a wider variety of boundary conditions and on less ideal plates. Two classes of plates have been considered: clamped flat plates, and ribbed plates. On clamped flat plates an analytical …
Computational And Experimental Study Of Degeneration, Damage And Failure In Biological Soft Tissues, Gregory Allen Von Forell
Computational And Experimental Study Of Degeneration, Damage And Failure In Biological Soft Tissues, Gregory Allen Von Forell
Theses and Dissertations
The purpose of this work was to analyze the biomechanics of degeneration, damage, and failure in biological soft tissues both experimentally and computationally to provide insight into tendon or ligament tearing, tendo-achilles lengthening and lumbar spine dysfunction. For soft tissue tearing, experimental studies for calculating fracture toughness were performed and determined that tendons and ligaments are able to completely resist tear propagation. For tendo-achilles lengthening, a damage model was developed to mimic the behavior of the lengthening that occurs as a result of the percutaneous triple hemisection technique. The model provided insight for predicting the amount of lengthening that occurs …
Introducing The Vuepod: Development And Testing Of A Low-Cost Large-Scale Stereoscopic Immersive System Using 3d Lcd Televisions, Shane Makana Hayden
Introducing The Vuepod: Development And Testing Of A Low-Cost Large-Scale Stereoscopic Immersive System Using 3d Lcd Televisions, Shane Makana Hayden
Theses and Dissertations
3D immersive visualization systems, or CAVEs™, have found wide adoption for use in geosciences, planetary science, medical research, and computer science. However, much of the potential for such systems in practical civil and environmental engineering settings has been severely limited due to 1) extreme costs in both hardware and software; 2) immobility due to calibration and darkroom requirements; and 3) extensive and expensive manpower requirements for both operation and maintenance. This thesis presents the development and testing of a new mobile low-cost immersive stereo visualization system -- the "VuePod" -- that attempts to address these challenges through the use of …
Molecular Modeling Of Dna For A Mechanistic Understanding Of Hybridization, Terry Jacob Schmitt
Molecular Modeling Of Dna For A Mechanistic Understanding Of Hybridization, Terry Jacob Schmitt
Theses and Dissertations
DNA microarrays are a potentially disruptive technology in the medical field, but their use in such settings is limited by poor reliability. Microarrays work on the principle of hybridization and can only be as reliable as this process is robust, yet little is known at the molecular level about how the surface affects the hybridization process. This work uses advanced molecular simulation techniques and an experimentally-parameterized coarse-grain model to determine the mechanism by which hybridization occurs on surfaces and to identify key factors that influence the accuracy of DNA microarrays. Comparing behavior in the bulk and on the surface showed, …
Intercalibration Of Quikscat And Oscat Land Backscatter, John Colin Barrus
Intercalibration Of Quikscat And Oscat Land Backscatter, John Colin Barrus
Theses and Dissertations
The Ku-band SeaWinds-on-QuikSCAT scatterometer (QuikSCAT) operated continuously from 1999 to 2009. Though its primary mission was to estimate global ocean winds, QuikSCAT has proven useful in a variety of geophysical studies using land backscatter measurements. The end of the primary QuikSCAT mission in 2009 has prompted interest for continuing the QuikSCAT land dataset with other scatterometers. The Oceansat-2 scatterometer (OSCAT), launched in 2009, is a viable candidate for continuing the QuikSCAT time series because of the similarities of both sensors in function and design. An important difference in the sensors is that they operate at slightly different incidence angles. Continuing …
Structural Analysis And Optimization Of Skyscrapers Connected With Skybridges And Atria, Amy Jean Taylor Mccall
Structural Analysis And Optimization Of Skyscrapers Connected With Skybridges And Atria, Amy Jean Taylor Mccall
Theses and Dissertations
Skybridges and atria between buildings are becoming more and more popular. Most current skybridge connections are either roller or rigid-connections. This dissertation presents an investigation of the structural analysis and optimization of skyscraper systems with hinge-connected skybridges, and compares the results to skyscraper systems with roller-connected skybridges and to skyscraper systems without skybridges altogether. Also presented is an investigation of the structural analysis and optimization of skyscrapers both with and without atria between the buildings. It was assumed that the atria envelope was constructed with cushions made from lightweight, transparent, and flexible Ethylene Tetrafluoroethylene (ETFE). A simplified skyscraper skybridge model …
Polarization Diversity In The Presence Of Multipath Propagation, Grant Taylor Wagner
Polarization Diversity In The Presence Of Multipath Propagation, Grant Taylor Wagner
Theses and Dissertations
The possibility of polarization diversity using left and right hand circular polarization (LHCP and RHCP) in the presence of multipath propagation is examined. We show that there are differences in the received signal for LHCP and RHCP for a number of realistic scenarios. Because multipath propagation can produce different LHCP and RCHP signals, there exists the possibility for diversity improvement involving the two polarizations.
Cooperative Target Tracking Enhanced With The Sequence Memoizer, Everett A. Bryan
Cooperative Target Tracking Enhanced With The Sequence Memoizer, Everett A. Bryan
Theses and Dissertations
Target tracking is an important part of video surveillance from a UAV. Tracking a target in an urban environment can be difficult because of the number of occlusions present in the environment. If multiple UAVs are used to track a target and the target behavior is learned autonomously by the UAV then the task may become easier. This thesis explores the hypothesis that an existing cooperative control algorithm can be enhanced by a language modeling algorithm to improve over time the target tracking performance of one or more ground targets in a dense urban environment. Observations of target behavior are …
Methods And Metrics For Human Interaction With Bio-Inspired Robot Swarms, Sean C. Kerman
Methods And Metrics For Human Interaction With Bio-Inspired Robot Swarms, Sean C. Kerman
Theses and Dissertations
In this thesis we propose methods and metrics for human interaction with bio-inspired robot teams. We refine the concept of a stakeholder and demonstrate how a human can use stakeholders to lead a swarm as well as switch the swarm between different collective behaviors. We extend the human interaction metrics of interaction time and interaction effort presented in [1] to swarm systems and introduce the concept of interaction effort. These metrics allow us to understand how well the system performs under human influence. We employ systems theory to estimate these metrics, which is useful because this can be done without …
The Effects Of Wrist Orthoses On The Stiffness Of Wrist Rotations, Daniel Brad Seegmiller
The Effects Of Wrist Orthoses On The Stiffness Of Wrist Rotations, Daniel Brad Seegmiller
Theses and Dissertations
Wrist orthoses are the most common upper limb orthoses, being used by thousands of individuals each year to stabilize, immobilize, or support the wrist joint. Wrist orthoses achieve their function by altering the stiffness of the wrist joint (Figure 1-1). However, there is no quantitative understanding of how wrist orthoses affect wrist stiffness, and consequently, wrist orthosis development often relies on feel, intuition, or empirical heuristics rather than a methodical, quantitative approach. Because wrist movement control is dominated by wrist joint stiffness (Charles and Hogan 2011) a quantitative understanding of how wrist orthoses alter the stiffness of the wrist is …
Second-Order Perturbation Analysis Of The St. Venant Equations In Relation To Bed-Load Transport And Equilibrium Scour Hole Development, Frans Joseph Lambrechtsen
Second-Order Perturbation Analysis Of The St. Venant Equations In Relation To Bed-Load Transport And Equilibrium Scour Hole Development, Frans Joseph Lambrechtsen
Theses and Dissertations
This analysis is an expansion of research done by Rollin Hotchkiss during his Ph.D work. The research uses fluid flow, sediment transport, and perturbation theory to predict where scour will occur in a variable-width channel. The resulting equations also determine equilibrium scour depth based upon the stream bed elevation derived from a dimensionless bed slope equation. Hotchkiss perturbed the width of the channel using a second order Taylor Series perturbation but neglected second order terms. The present work follows the same procedures as Hotchkiss but maintains the second order terms. The primary purpose is to examine how the additional terms …
Burnout, No, Flame Temperature, And Radiant Intensity From Oxygen-Enriched Combustion Of A Hardwood Biomass, Joshua David Thornock
Burnout, No, Flame Temperature, And Radiant Intensity From Oxygen-Enriched Combustion Of A Hardwood Biomass, Joshua David Thornock
Theses and Dissertations
Increasing concern for energy sustainability has created motivation for the combustion of renewable, CO2 neutral fuels. Biomass co-firing with coal provides a means of utilizing the scaled efficiencies of coal with the lower supply availability of biomass. One of the challenges of co-firing is the burnout of biomass particles which are typically larger than coal but must be oxidized in the same residence time. Larger biomass particles also can increase the length of the radiative region and alter heat flux profiles. As a result, oxygen injection is being investigated as a means of improving biomass combustion performance.An Air Liquide designed …
Deicer Usage On Concrete And Asphalt Pavements In Utah, Chase David Thomas
Deicer Usage On Concrete And Asphalt Pavements In Utah, Chase David Thomas
Theses and Dissertations
The objectives of this research were to 1) compile winter maintenance data for the Utah Department of Transportation (UDOT) to directly compare concrete and asphalt pavements with regards to deicer usage and 2) determine if there is a statistical difference in deicer usage on concrete and asphalt pavements. To this end, three data sources were consulted for this research: Material Maintenance Quality Assurance (MMQA) database, UDOT road database, and Google Maps. The final compiled data set prepared for analysis in this research contained deicer quantities by deicer type, pavement surface areas by pavement material type, traffic, longitude, latitude, and elevation …
Proteins In High Electric Fields, David Michael Landry
Proteins In High Electric Fields, David Michael Landry
Theses and Dissertations
Being able to control protein function directly and in real time is attractive. In this thesis, I discuss controlling protein activity using alternating current electric fields on the order of 1 MV/m. Since protein structures result in localized and/or protein-wide charge gradients, it is expected that a sufficiently high electric field applied across a protein should result in structural distortions which can temporarily alter or halt protein function. The field is set to oscillate above the influences of the electrochemical double layer effects (1 kHz) and below the level needed for hydrodynamic rotation of proteins (10 MHz). A device is …
An Investigation Of The Asit Problem-Solving Method On Middle School Technology Education Student's Ability To Produce Creative Solutions, Jared Aaron Merrill
An Investigation Of The Asit Problem-Solving Method On Middle School Technology Education Student's Ability To Produce Creative Solutions, Jared Aaron Merrill
Theses and Dissertations
This study compared two groups of students being instructed in various methods of problem solving over a two-week period. The control group was instructed using the standard Career and Technology Education (CTE) Introduction curriculum on using brainstorming to solve problems. The treatment group was instructed using a structured problem solving method developed to help focus problem solving on finding a solution that satisfies the conditions. Students were selected from 7th grade students at a suburban middle school in Utah. The independent variable in this study was the type of problem solving instruction received. The dependent variables of interest were the …
Water Fat Separation With Multiple-Acquisition Balanced Steady-State Free Precession Mri, Michael A. Mendoza
Water Fat Separation With Multiple-Acquisition Balanced Steady-State Free Precession Mri, Michael A. Mendoza
Theses and Dissertations
Magnetic resonance imaging (MRI) is an important medical imaging technique for visualizing soft tissue structures in the body. It has the advantages of being noninvasive and, unlike x-ray, does not rely on ionizing radiation for imaging. In traditional hydrogen-based MRI, the strongest measured signals are generated from the hydrogen nuclei contained in water and fat molecules.Reliable and uniform water fat separation can be used to improve medical diagnosis. In many applications the water component is the primary signal of interest, while the fat component represents a signal which can obscure the underlying pathology or other features of interest. In other …
Characterization And Processing Evaluation Of Starch/High-Density Polyethylene Materials In Extrusion Blow Molding, Bradley Dale Bacigalupi
Characterization And Processing Evaluation Of Starch/High-Density Polyethylene Materials In Extrusion Blow Molding, Bradley Dale Bacigalupi
Theses and Dissertations
The growing negative impacts of non-biodegradable plastics derived from non-renewable materials have created increasing interest throughout the world for new materials that are both biodegradable and renewable, that can be combined with or replace traditional plastics. Plant-based thermoplastic starch (TPS), a promising alternative material to traditional petroleum based resin, is both biodegradable and renewable and has great potential for use in plastic manufacturing processes. Two major obstacles that prevent more widespread use of TPS include; TPS base material, which is typically manufactured in a flake or powder, is incompatible with standard plastics production equipment that require pelletized resin, the second …
Interface Design And Synthesis For Structural Hybrid Microarchitectural Simulators, Zhuo Ruan
Interface Design And Synthesis For Structural Hybrid Microarchitectural Simulators, Zhuo Ruan
Theses and Dissertations
Computer architects have discovered the potential of using FPGAs to accelerate software microarchitectural simulators. One type of FPGA-accelerated microarchitectural simulator, namedthe hybrid structural microarchitectural simulator, is very promising. This is because a hybrid structural microarchitectural simulator combines structural software and hardware, and this particular organization provides both modeling flexibility and fast simulation speed. The performance of a hybrid simulator is significantly affected by how the interface between software and hardware is constructed. The work of this thesis creates an infrastructure, named Simulator Partitioning Research Infrastructure (SPRI), to implement the synthesis of hybrid structural microarchitectural simulators which includes simulator partitioning, simulator-to-hardware …