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Articles 751 - 780 of 1335
Full-Text Articles in Civil and Environmental Engineering
Friction Bit Joining Of Dissimilar Combinations Of Advanced High-Strength Steel And Aluminum Alloys, Lile P. Squires
Friction Bit Joining Of Dissimilar Combinations Of Advanced High-Strength Steel And Aluminum Alloys, Lile P. Squires
Theses and Dissertations
Friction bit joining (FBJ) is a new method that enables lightweight metal to be joined to advanced high-strength steels. Weight reduction through the use of advanced high-strength materials is necessary in the automotive industry, as well as other markets, where weight savings are increasingly emphasized in pursuit of fuel efficiency. The purpose of this research is twofold: (1) to understand the influence that process parameters such as bit design, material type and machine commands have on the consistency and strength of friction bit joints in dissimilar metal alloys; and (2) to pioneer machine and bit configurations that would aid commercial, …
Correlation Between Multiple Stress Creep Recovery (Mscr) Results And Polymer Modification Of Binder, Eric Dubois
Correlation Between Multiple Stress Creep Recovery (Mscr) Results And Polymer Modification Of Binder, Eric Dubois
Theses and Dissertations
Nationwide traffic loads are increasing, pushing conventional asphalt to its limit, while in New Jersey matters are made worse by the heavy use of the Northeast Corridor. Polymer modification of asphalt, which can improve both low and high temperature performance, is already available; however, but in many cases traditional Superpave testing is not sensitive enough to quantify the impact of modification, dimensioning its use. Superpave Performance Grade Plus tests, are sensitive to polymer modification but are time intensive and costly, leading the New Jersey Department of Transportation to require styrene-butadiene or styrene-butadiene-styrene to be incorporated in all modified binder to …
Current Bim Practices Of Commercial Mep Contractors, Bryan John Kent
Current Bim Practices Of Commercial Mep Contractors, Bryan John Kent
Theses and Dissertations
Building Information Modeling (BIM) use in the contracting industry has grown significantly in recent years. With this change in the construction industry, consensus has not been reached as to what BIM is, who is using it and what they are using it for. The purpose of this research was to determine current BIM practices of US-based commercial MEP contractors. Executive, middle management, and field personnel were interviewed to determine the current BIM practices in their companies. The majority of companies interviewed were using BIM and most were using it on a significant portion of their projects. The majority of MEP …
Analysis Of Long-Term Utah Temperature Trends Using Hilbert-Haung Transforms, Brent H. Hargis
Analysis Of Long-Term Utah Temperature Trends Using Hilbert-Haung Transforms, Brent H. Hargis
Theses and Dissertations
We analyzed long-term temperature trends in Utah using a relatively new signal processing method called Empirical Mode Decomposition (EMD). We evaluated the available weather records in Utah and selected 52 stations, which had records longer than 60 years, for analysis. We analyzed daily temperature data, both minimum and maximums, using the EMD method that decomposes non-stationary data (data with a trend) into periodic components and the underlying trend. Most decomposition algorithms require stationary data (no trend) with constant periods and temperature data do not meet these constraints. In addition to identifying the long-term trend, we also identified other periodic processes …
Termediator-Ii: Identification Of Interdisciplinary Term Ambiguity Through Hierarchical Cluster Analysis, Owen G. Riley
Termediator-Ii: Identification Of Interdisciplinary Term Ambiguity Through Hierarchical Cluster Analysis, Owen G. Riley
Theses and Dissertations
Technical disciplines are evolving rapidly leading to changes in their associated vocabularies. Confusion in interdisciplinary communication occurs due to this evolving terminology. Two causes of confusion are multiple definitions (overloaded terms) and synonymous terms. The formal names for these two problems are polysemy and synonymy. Termediator-I, a web application built on top of a collection of glossaries, uses definition count as a measure of term confusion. This tool was an attempt to identify confusing cross-disciplinary terms. As more glossaries were added to the collection, this measure became ineffective. This thesis provides a measure of term polysemy. Term polysemy is effectively …
Unattended Remotely Operated Deep-Water Sediment Oxygen Demand Chambers, Drake Theodore Mailes
Unattended Remotely Operated Deep-Water Sediment Oxygen Demand Chambers, Drake Theodore Mailes
Theses and Dissertations
Dissolved oxygen (DO) depletion in a water body is governed by two primary mechanisms: biological oxygen demand (BOD) from the water column, and sediment oxygen demand (SOD) from sediments. SOD is the dominant oxygen sink in many water bodies; measurements show as much as 95% of oxygen consumption as attributable to SOD (Truax, Shindala, & Sartain, 1996). Measuring SOD in surface water impoundments is an essential component in evaluating and an important input for modeling the health of a water body. Traditional SOD measurement methods are difficult in deeper waters, such as in reservoirs or lakes, because traditional SOD measurement …
Strength Of Masonry Grout Made With Expanded Shale, Allison Tanner
Strength Of Masonry Grout Made With Expanded Shale, Allison Tanner
Theses and Dissertations
Light-weight aggregate has been used successfully for structural and non-structural applications, and its most common use has been in light-weight concrete. Limited research has been done on light-weight grout though and there are no standards in place. The research performed in this study is intended to increase the knowledge of light-weight grout specifically made with expanded shale aggregate. The research presented herein is a pilot study and consists of preliminary aggregate and grout testing that resulted in the mix design of six grout types: three fine grout designs and three coarse grout designs. Conventional normal-weight aggregate was employed in the …
Sensitivity Of Electrochemical Impedance Spectroscopy Measurements To Concrete Bridge Deck Properties, Hillary Mckenna Argyle
Sensitivity Of Electrochemical Impedance Spectroscopy Measurements To Concrete Bridge Deck Properties, Hillary Mckenna Argyle
Theses and Dissertations
Numerous methods have been developed to measure corrosion potential relating to chloride infiltration in concrete, including an emerging application of electrochemical impedance spectroscopy (EIS). EIS involves measurements of electrical impedance to evaluate the corrosion potential of steel reinforcement in concrete. With EIS, current is injected vertically into the concrete bridge deck between the surface and the embedded reinforcing steel, usually the top mat, to evaluate the degree to which the reinforcing steel is protected from chloride infiltration by the entire bridge deck system. The objectives of this research were to 1) investigate the sensitivity of EIS measurements obtained at various …
Public Safety At Low-Head Dams: Fatality Database And Physical Model Of Staggered Deflector Retrofit Alternative, Edward William Kern
Public Safety At Low-Head Dams: Fatality Database And Physical Model Of Staggered Deflector Retrofit Alternative, Edward William Kern
Theses and Dissertations
Low-head dams can cause dangerous currents near the downstream face of the structure. Fatalities at low-head dams are poorly documented. This thesis introduces a website with an interactive map and database of fatalities at low-head dams in the United States. The purpose of the web site is to generate interest among the general public to increase support to remediate dangerous structures and to serve as a tool for public education. The user interface allows the general public to browse fatal incidents by geographic location and to read incident circumstances. The site allows submission of public contributions including all metadata needed …
Determining Dispersion Coefficients In Sewer Networks, Joshua G. Wagstaff
Determining Dispersion Coefficients In Sewer Networks, Joshua G. Wagstaff
Theses and Dissertations
This work determines a suitable value for a dispersion coefficient to be used in the One-Dimensional Advection-Dispersion equation to model dispersion within sewer collection systems. Dispersion coefficients for sewer systems have only recently begun to be studied, and there is not yet an established value that is commonly accepted. The work described in this paper aimed, through observational study, to find a suitable value to be used. Salt tracers were placed in two separate reaches of sewer line. The first line studied was a straight, linear reach of sewer that included three manholes. The tracer was placed in the first …
Multi-Rotor--Aided Three-Dimensional 802.11 Wireless Heat Mapping, Scott James Pack
Multi-Rotor--Aided Three-Dimensional 802.11 Wireless Heat Mapping, Scott James Pack
Theses and Dissertations
Traditional wireless site surveys produce a heat-map of link strength or quality over a target area, usually on the ground plane. In recent years research has gone into using aerial drones in network attack and surveillance, making three dimensional awareness of wireless coverage areas of interest. A multi-rotor drone and data collection module were built and tested as part of this research. Site assessments were conducted both in open space and near structures. Collected data was interpolated across the target area, and visualized as points and contours. These visualizations were exported to a Keyhole Markup Language (KML) for visualization in …
Development Of A Chloride Concentration Sampling Protocol For Concrete Bridge Decks, Sharlan Renae Montgomery
Development Of A Chloride Concentration Sampling Protocol For Concrete Bridge Decks, Sharlan Renae Montgomery
Theses and Dissertations
As the primary cause of concrete bridge deck deterioration in the United States is corrosion of the steel reinforcement as a result of the application of chloride-based deicing salts, chloride concentration testing is among the most common techniques for evaluating the condition of a concrete bridge deck. The objectives of this research were to 1) compare concrete drilling and powder collection techniques to develop a sampling protocol for accurately measuring chloride concentrations and 2) determine the number of chloride concentration test locations necessary for adequately characterizing the chloride concentration of a given bridge deck. Laboratory experiments on concrete drilling and …
Design Considerations For A Water Treatment System Utilizing Ultra-Violet Light Emitting Diodes, Michael J. Spencer
Design Considerations For A Water Treatment System Utilizing Ultra-Violet Light Emitting Diodes, Michael J. Spencer
Theses and Dissertations
UV LED technology is in its infancy and research as it applies to UV water treatment is required to advance knowledge for practical application. This thesis focused on two subjects. First, the design, fabrication, and operation of a water treatment reaction system utilizing Ultra-Violet (UV) Light Emitting Diodes (LEDs). Second, the measurement of UV LED output angle in water which is necessary to support future reactor designs. Several characteristics of the LED-water interface were revealed which impacted the effectiveness of the vessel including; UV dose requirements, LED wavelength, photon dispersion geometry, LED placement, optical efficiency, vessel material, and electronic control …
Ultraviolet Light Emitting Diode Use In Advanced Oxidation Processes, Kelsey L. Duckworth
Ultraviolet Light Emitting Diode Use In Advanced Oxidation Processes, Kelsey L. Duckworth
Theses and Dissertations
Cleanup from a hazardous chemical release can result in large volumes of water containing hazardous materials, such as organophosphates. Unfortunately, this water cannot be treated in a municipal wastewater treatment plant without adversely affecting the performance of the plant. A known method for pretreating this water to prepare it for processing in a traditional treatment plant includes the addition of hydrogen peroxide, followed by ultraviolet (UV) light exposure to form reactive hydroxyl radicals which oxidize the chemical. Light emitting diodes (LEDs) are explored as a UV source as they are durable; compact; can be powered by low voltage, direct current …
Environmentally Friendly And Sustainable Stream Stability In The Vicinity Of Bridges, Evan David Cope
Environmentally Friendly And Sustainable Stream Stability In The Vicinity Of Bridges, Evan David Cope
Theses and Dissertations
This report was sponsored by the Utah Department of Transportation (UDOT) to determine if stream restoration structures could be used as scour countermeasures near state highways and bridges. Scour countermeasures that are effective in preventing erosion exist but that are not so friendly for aquatic organisms. UDOT is interested in finding a countermeasure that is both effective in preventing erosion while not harming aquatic organisms. Stream restoration structures are friendly for aquatic organisms but are prone to failure when flows exceed the design levels. David Rosgen has developed restoration structures that are friendly for aquatic organisms and that have provided …
Development And Regional Application Of Sub-Seasonal Remote- Sensing Chlorophyll Detection Models, Carly Adeline Hyatt
Development And Regional Application Of Sub-Seasonal Remote- Sensing Chlorophyll Detection Models, Carly Adeline Hyatt
Theses and Dissertations
Remote sensing has been used as an effective chlorophyll-a detection method in inland lakes and reservoirs. Concentration estimates of chlorophyll-a approximate the amounts of algae and phytoplankton in a body of water, can indicate the existence of large blooms and high nutrient loading, and can be used as an indicator of water quality. These biomasses pose potential threats to the quality of the water and the local environment by depleting oxygen, influencing the taste of the drinking water and detrimentally affecting aesthetics and recreation. Deer Creek Reservoir exhibited eutrophic tendencies in the early 1990's, caused by phosphorus pollution. This was …
Impact Of Structure, Material Properties, Temperature Curling, And Trafficking On Load Transfer Efficiency, Charles Cunliffe
Impact Of Structure, Material Properties, Temperature Curling, And Trafficking On Load Transfer Efficiency, Charles Cunliffe
Theses and Dissertations
This study examines the impact of structure, material properties, temperature gradient and trafficking on load transfer efficiency of rigid airfield pavements. The current FAA mechanistic design procedure for rigid pavements assumes constant stress-based load transfer efficiency (LTE (S)) of 25% at the joints. The design procedure assumes the material properties remain constant throughout the life of the pavement. Furthermore, the design procedure does not directly consider the effect that temperature induced slab curling can have on joint LTE (S). Analysis is conducted from full scale accelerated pavement test data from the National Airport Pavement Test Facility (NAPTF) operated by the …
Understanding Hydrothermal Carbonization Of Mixed Feedstocks For Waste Conversion, Xiaowei Lu
Understanding Hydrothermal Carbonization Of Mixed Feedstocks For Waste Conversion, Xiaowei Lu
Theses and Dissertations
Hydrothermal carbonization (HTC) is an environmentally beneficial means to convert waste materials to value-added solid and liquid products with minimal greenhouse gas emission. Research is lacking on understanding the influence of critical process conditions on product formation and environmental implication associated with HTC of waste streams. This work was conducted to determine how reaction conditions and heterogeneous compound mixtures (representative of municipal wastes) influence hydrothermal carbonization processes. The specific experiments include: (1) determine how carbonization product properties are manipulated by controlling feedstock composition, process conditions, and catalyst addition; (2) determine if carbonization of heterogeneous mixtures follows similar pathways as that …
Use Of In-Situ Tests To Identify Soil Behavior Type And Liquefaction Susceptibility Of Sccp Soils, Rajshekhar Sarkar
Use Of In-Situ Tests To Identify Soil Behavior Type And Liquefaction Susceptibility Of Sccp Soils, Rajshekhar Sarkar
Theses and Dissertations
For many years, the Cone Penetrometer Test (CPT), Flat Plate Dilatometer Test (DMT) and Standard Penetration Test (SPT) have been used as in-situ tools to assess the liquefaction potential of soils. Given the importance of evaluating liquefaction potential in the South Carolina Coastal Plain (SCCP), research was conducted to study the soil behavior of soils prone to liquefaction, develop site specific correlations between SPT, DMT and CPT testing parameters and evaluate the liquefaction susceptibility of the soils in the SCCP. The SCCP sites studied in this thesis are Sampit (SAM), Gapway (GAP), Hollywood (HWD), Four Hole Swamp (FHS) and Fort …
Bio-Inspired And Low-Content Polymer Cement Mortar For Structural Rehabilitation, Nima Zohhadi
Bio-Inspired And Low-Content Polymer Cement Mortar For Structural Rehabilitation, Nima Zohhadi
Theses and Dissertations
Use of polymers as partial replacement for Portland cement in cement mortar and concrete can diminish several drawbacks of these composites such as low tensile strength and strain capacity, high permeability and low adhesion. Main reasons for the use of polymers are to improve damage tolerance, adhesion, and resistance to water permeation. Various polymers with a wide range of physical and mechanical properties have been used in fabrication of cementitious composites. Typical polymer content for such composites is 5% to 20% (by the weight of cement) for both mortar and concrete. There are also drawbacks associated with the use of …
High Throughput Multi-Solution Genetic Algorithm (Htmga) For Identification Of Alternate Solutions In A Structural Model Updating Context, Muslum Kilinc
Theses and Dissertations
Model updating techniques seek to improve numerical models of existing structure by integrating experimental data from the structure. Many techniques use an error function that describes the differences between the numerical model and the experimental data. For example, if dynamic data is available, the error between experimental and numerical modal parameters can be used. Optimization techniques are used to identify the structural parameters that minimize this function. Most model updating techniques are interested in finding the global minima of the error function. However, one could argue that due to a number of factors, such as modeling errors and low sensor …
A Cost/Benefit Evaluation Of Incentives Paid For Asphalt Concrete Hot Mix (Achm) Properties, Christopher T. Mckenney
A Cost/Benefit Evaluation Of Incentives Paid For Asphalt Concrete Hot Mix (Achm) Properties, Christopher T. Mckenney
Theses and Dissertations
The purpose of this study was establishing if projects receiving incentive payments for Asphalt Concrete Hot Mix (ACHM) properties were providing a better quality and longer pavement life cycle. Reviewing governmental agencies' and states' Department of Transportation (DOT) standards, through literary review, indicated other possible guidelines and recommendations. Results were formulated by employing a specific methodology, allowing for data validation through an ordered series of groupings and project pairings. Arkansas Highway and Transportation Department (AHTD) databases furnished essential pavement data to accomplish this task. Derived from methodology, data analysis supported the comparison analysis of selected construction projects. Documented conclusions validated …
Network Interdependency Modeling For Risk Assessment On Built Infrastructure Systems, Vhance V. Valencia
Network Interdependency Modeling For Risk Assessment On Built Infrastructure Systems, Vhance V. Valencia
Theses and Dissertations
As modern infrastructures become more interconnected, the decision-making process becomes more difficult because of the increased complexity resulting from infrastructure interdependencies. Simulation and network modeling provide a way to understand system behavior as a result of interdependencies. One area within the asset management literature that is not well covered is infrastructure system decay and risks associated with that decay. This research presents an enhanced version of Haimes' input-output inoperability model (IIM) in the analysis of built infrastructure systems. Previous applications of the IIM characterized infrastructure at the national level utilizing large economic databases. This study develops a three-phased approach that …
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 …
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 …
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 …
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 …
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 …
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 …
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 …