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Numerical And Semi-Analytical Estimation Of Convective Heat Transfer Coefficient For Buildings In An Urban-Like Setting, Anwar Demsis Awol

Electronic Thesis and Dissertation Repository

Urban building arrangements such as packing density, orientation and size are known to influence the microclimate surrounding each building. Studies on the impact of urban microclimatic changes on convective heat transfer coefficient (CHTC) from a stock of buildings, however, have been rare in surveyed literature. The present study focuses on numerical and analytical investigation of CHTC from building-like models with homogeneous set of equal and unequal planar and frontal densities. Consequently, the study discusses the CHTC response in relation to broader changes in the urban surface form. Part of the process involves the development of a simplified one-dimensional semi-analytical CHTC …

Spatial And Temporal Characteristics Of Temperature-Precipitation Covariability Across Canada In A Changing Climate, Harsimrenjit Singh

Electronic Thesis and Dissertation Repository

Changes in the regional characteristics of temperature and precipitation can intensify the occurrence and severity of extreme events such as rain-on-snow induced flooding, droughts and wildfires. Analyzing these climate variables in isolation without considering their interdependencies might result in severe underestimation of their combined effects. In this study, copula functions are used to describe the joint behaviour of temperature and precipitation across Canada over a historical period of 1910-present using observations and further till the end of the 21st century using three large ensembles of regional climate models. Moreover, given the lack of observation data over Canada, gridded datasets are …

High Strain Dynamic Test On Helical Piles: Analytical And Numerical Investigations, Mohammed Fahad Alwalan

Electronic Thesis and Dissertation Repository

Helical piles are currently considered a preferred foundation option in a wide range of engineering projects to provide high compressive and uplift resistance to static and dynamic loads. In view of the large capacity of large diameter helical piles, there is a need to determine their capacity using accurate and economically feasible testing techniques. The capacity of piles is usually determined by conducting a Static Load Test (SLT). However, the SLT can be costly and time consuming, especially for large capacity piles. The High Strain Dynamic Load Test (HSDT) evaluates the pile capacity using dynamic measurements generated through subjecting the …

Application Of Bayesian Networks To Integrity Management Of Energy Pipelines, Wei Xiang

Electronic Thesis and Dissertation Repository

Metal-loss corrosion and third-party damage (TPD) are the leading threats to the integrity of buried oil and natural gas pipelines. This thesis employs Bayesian networks (BNs) and non-parametric Bayesian networks (NPBNs) to deal with four issues with regard to the reliability-based management program of corrosion and TPD. The first study integrates the quantification of measurement errors of the ILI tools, corrosion growth modeling and reliability analysis in a single dynamic Bayesian network (DBN) model, and employs the parameter learning technique to learn the parameters of the DBN model from the ILI-reported and filed-measured corrosion depths. The second study develops the …

Modeling The Effects Of Distribution System Topology On Water Quality, Chun-Ying Chao

McKelvey School of Engineering Theses & Dissertations

Inadequate treatment of drinking water causes the formation of disinfection by-products and the regrowth of harmful microbial species. Various studies have addressed the problem of water quality monitoring, but very few have employed topological analysis, a valuable mathematical tool widely applied in biological, business, and social research. This thesis examines the relationship between the topological properties of water distribution systems and water-quality models. In particular, the research proposes a novel framework for mapping network topological attributes to water-quality models. This research adopts topological metrics to assess the accuracy of the predictions of chlorine concentrations in dead ends. It examines four …

Optimizing On-Street Parking Supply With Analytical Models, Chawalit Tipagornwong

Dissertations and Theses

Commercial vehicles are crucial for the urban economy, but they generate negative impacts as well. This leads to restrictions such as a reduction in the number of loading zones. The result is that commercial drivers spend a significant amount of time searching for available loading zones. To avoid searching for parking, some commercial drivers double park, which causes traffic congestion. Therefore, the number of loading zones should be set properly. Since a curb is allocated between both loading zones and parking spaces, both parking types have to be considered. Many on-street parking management strategies have been implemented, including pricing meter …

Model Block Press Design, Ben Todd Van Hamersveld, Chester Wong, Alexander Wing-Jon Giannousis

Mechanical Engineering

This project’s goal is to redesign the Center for Vocational Building Technology (CVBT) BP9 earth block press, which makes 1/3 scale compressed earth blocks to build demonstration model homes in Thailand. The full-scale block press, the BP6, provides a sustainable and affordable technique for constructing habitable homes in Thailand. The BP9 serves as a tool to inform the public of the advantages of human-powered earth block presses through demonstration. The BP9 press design has multiple problems: it is too expensive to manufacture, there is too much friction when used, it has several weak points due to users unintentionally applying excessive …

Means And Methods Of Residential Construction And Design In Remote Areas Of Southeast Alaska, Joseph Anthony Masters

Construction Management

Building in the remote locations of Southeast Alaska is currently an unexplored area of construction that has been avoided due to the complications that accompany such projects. Many property owners in the Southeast Alaska region face challenges due to a lack of common practices that would simplify the construction process, particularly those deprived of road access and utility services. These potential residents must rely on sustainable techniques and alternative modes of material transportation, creating an abundance of planning concerns. Additionally, while code restrictions are limited due to the uniqueness of these properties, certain codes regarding the Alaska Department of Natural …

Pilot-Scale Test Of Water Wash Carbon Dioxide Absorption System For Purifying Landfill Gas At Jones Island Wastewater Reclamation Facility, Rebecca Schruender

Theses and Dissertations

Biogas, a product of the digestion of organic material, consists primarily of methane and carbon dioxide. By purifying raw biogas, or removing the carbon dioxide, it can be upgraded to biomethane, which can be used to generate heat and electricity or as a substitute for natural gas. An effective method of biogas purification is the water wash process, which consists of an absorption column in which a stream of biogas runs counter-current to a stream of water. The carbon dioxide dissolves in the water, increasing the methane concentration of the gas. A pilot scale system was operated at Jones Island …

Weigh-In-Motion Auto-Calibration Using Automatic Vehicle Identification, Fu Ren Zhang Zhang Durandal

Graduate Theses and Dissertations

Weigh-in-Motion (WIM) sensors are installed on mainline lanes at highway locations to record vehicle weights, axle spacing, vehicle class, travel speed, vehicle length, and traffic volume. These data elements support effective transportation planning, infrastructure design, and policy development. Therefore, it is important that WIM sensors supply accurate data. After initial installation and calibration, WIM systems may experience measurement drifts in weight and axle detection. Recalibration takes two general forms: (a) On-site calibration involving running trucks of known weight over WIM scales and (b) Auto-calibration methods involving comparisons to assumed reference weights. Auto-calibration can be more cost and time effective than …

Cytotoxicity And Mutagenicity Of Disinfection Byproduct Mixtures Formulated Using Free Chlorine And Monochloramine, Yonas Ghebremedhin

Graduate Theses and Dissertations

Bioassays have been used extensively to assess various toxicity endpoints of drinking water disinfection byproducts (DBPs), but an emphasis on single compounds prevails. In this research, DBP mixtures were assessed using a cytotoxicity test with Chinese Hamster Ovary (CHO) cells and an Ames fluctuation test with Salmonella typhimurium TA-98 and TA-100 with and without S9 rat liver homogenate. Seven whole mixture DBP concentrates were formulated using reconstituted natural organic matter (NOM) extracts from the Upper Mississippi River using scaled disinfectant dosing protocols with free chlorine and monochloramine in the presence and absence of added bromide. DBPs were identified by gas …

Evaluation Of Fracture Principles In Asphalt Concrete Utilizing The Sc(B) Geometry, Airam Marlee Morales Vega

Graduate Theses and Dissertations

Since cracking is one of the principal distresses to be considered in asphalt concrete, multiple fracture tests and geometries have been used to quantify cracking resistance. One of the most popular geometries that have been used in fracture tests is the Semi-Circular bend (SC(B)). However, for this geometry, most of the fracture test methods use different parameters such as thickness, testing temperatures, and loading rates. Thus, the purpose of this research was first to evaluate fracture energy by performing a ruggedness test based on ASTM E1169. Then, to apply fracture mechanics concepts to evaluate three specimen thicknesses (25, 50, and …

Incorporating Geophysical Data In Slope Stability Modeling For Two Slopes In Arkansas, Vanessa Lebow

Graduate Theses and Dissertations

Slope failures in the United States alone cause millions of dollars in damage to infrastructure, threaten national monuments, create environmental hazards, and take an average of 25-50 lives a year. With the inevitable construction that occurs on slopes, it is imperative that the slopes be properly designed which requires a thorough understanding of slope grade, subsurface soil conditions, soil strength parameters, water table locations, and depth to bedrock across the entire site. The preferred method of data collection would be to use borings and other in-situ methods; however, sometimes due to cost constraints or site accessibility only a very limited …

Evaluation Of Concrete Deck Curing Regimens Using Capillary Pressure Sensing System, Samuel Spann

Graduate Theses and Dissertations

Early-age plastic shrinkage cracking is a common problem with the construction of concrete bridge decks due to the high surface area-to-volume ratio and exposure to potentially detrimental environmental effects. Curing regimens are utilized to mitigate cracking risk during the plastic stage of the concrete; the curing regimens evaluated for this study were wet burlap-polyethylene sheeting, two acrylic curing compounds, and one lithium compound. Capillary pressure in the water filled pores has been shown to correlate to the plastic shrinkage cracking risk of concrete. A new portable system has been developed to measure the capillary pressure that could potentially be used …

Truck Activity Pattern Classification Using Anonymous Mobile Sensor Data, Taslima Akter

Graduate Theses and Dissertations

To construct, operate, and maintain a transportation system that supports the efficient movement of freight, transportation agencies must understand economic drivers of freight flow. This is a challenge since freight movement data available to transportation agencies is typically void of commodity and industry information, factors that tie freight movements to underlying economic conditions. With recent advances in the resolution and availability of big data from Global Positioning Systems (GPS), it may be possible to fill this critical freight data gap. However, there is a need for methodological approaches to enable usage of this data for freight planning and operations.

To …

Study Of Internal Strains Developed In Concrete Decks At Early Ages In Steel Continuous Bridges, Fernando R. Benitez Ortiz

Graduate Theses and Dissertations

The Arkansas Department of Transportation (ARDOT) has identified bridge deck cracking shortly after concrete decks are placed and prior to applying traffic loads. Previous researchers have confirmed improper construction practices and design methods can lead to deck cracking. Currently, many contractors throughout Arkansas are using continuous deck pours. This construction approach may restrict the concrete slab from movement during early age shrinkage, causing tensile stresses to develop. The final stresses at the end of construction must be lower than the concrete tensile strength, if not cracking issues will develop. Eventually, these cracks may enlarge due to service load stresses and …

Reducing Thermal Bridging And Understanding Second-Order Effects In Concrete Sandwich Wall Panels, Taylor J. Sorensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Structural engineers have traditionally detailed structures with structural and fabrication efficiency in mind, but often based on a limited understanding of thermal efficiency. Some connection designs can create significant thermal bridging, leading to unnecessary heat transfer and even premature degradation through condensation. Thermal bridging occurs when heat transfer is given a path through a more conductive material like concrete or steel rather than insulation. Concrete sandwich wall panels (SWP) tend to be highly efficient at preventing heat transfer in the middle of panels, with greatest heat transfer occurring at connections. This project identified thermally efficient details for future SWP construction …

Surface Modification Of Pvdf Membranes For Treating Produced Waters By Direct Contact Membrane Distillation, Zahra Anari

Graduate Theses and Dissertations

Direct contact membrane distillation is a promising unit operation for treating hydraulic fracturing flow back and produced water. However, while a hydrophobic membrane is essential to prevent the passage of water from the feed to the permeate side, fouling by dissolved organic species can compromise membrane performance and result in wetting of the membrane pores. Here four monomers, hydroxyethylmethacrylate, acrylic acid, 1-vinyl-3-allylimidazolium bromide, and 1-vinyl-3-hexylimidazolium bromide have been grafted from the surface of a PVDF membrane. The modified and base membranes were tested in a direct contact membrane distillation system. All membranes were challenged with real produced water. In addition, …

Experimental Investigation Of Utilizing Steel Fiber As Concrete Reinforcement In Bridge Decks, Samed Al Khafaji

Civil Engineering Theses

Research on utilizing steel fiber vs concrete reinforcement in bridge deck to replace more traditional reinforcing bars is sparse, therefore a research into this topic is interesting to identity opportunities for speeding up of construction by avoiding laying and tying reinforcement and verifying clear cover to reinforcing bars which is one of the most time-consuming processes involved in construction. This study investigates the efforts of steel fiber on the bridge deck from the strength and economical implementation. Four concrete mix design with vary steel fiber dosages of 0.0%, 0.5%, 1.0%, and 1.5% used in this study. The physical properties of …

Physical Characterization And Evaluation Of Energy Potential For Mined Waste From Irving Landfill, Vijay Kakara

Civil Engineering Theses

Historically landfills have been seen as the ultimate solution for storing waste at minimum cost. But, now it is a well-known fact that these deposits have numerous implications such as long term methane emissions, local pollution and many space-related issues etc. In most parts of the world, however, landfilling is the most common method to dispose waste. Even developed countries with recycling and waste treatment facilities have been no exception in landfilling. Therefore over the years, several old and operating landfills have been accumulated with an enormous amount of obsolete materials and products. To address such issues related to waste …

Effect Of Sewage Sludge And Wastewater Recirculation On The Degradation Of Municipal Solid Waste In Bioreactors, Afroza Ayub

Civil Engineering Theses

Municipal Solid Waste (MSW) management is the major environmental and economical concern for the world. Among all the MSW management alternatives, sustainable Bioreactor has potential to solve environmental and economic concerns related to organic waste. This potential of Sustainable Bioreactor can be enhanced by accelerated decomposition of waste. Accelerated decomposition of organic fraction of MSW can be achieved by the addition of nitrogen rich, macro and micro nutrients such as sludge and manures. Several studies have been conducted by using sludge as inoculum for degrading organic fraction of MSW in the anaerobic digester. However, this study is to compare the …

Seismic Response And Deformation Analyses Of Earthen Dams, Leila Mosadegh

Civil Engineering Dissertations

Assessment of the response of earthen structures, such as dams and levees, during earthquake events, is crucially important to geotechnical engineers. It is imperative to perform seismic response analysis to assess the stability and serviceability of these structures during probable seismic events. Before performing a seismic response analysis, an engineer or a researcher needs to select between two-dimensional (2D) plane strain analysis and a computationally intensive three dimensional (3D) analysis of an infrastructure. The 3D analysis should closely capture the behavior of infrastructure seismic response than a simplistic 2D analysis. Furthermore, a dilemma remains regarding the choice of a suitable …

Driveability Of Recycled Plastic Pin (Rpp) In North Texas, Arif Mohammad Aziz

Civil Engineering Theses

The Recycled Plastic Pins (RPP) have been extensively used as an alternative to the conventional slope stabilization methods in stabilizing shallows slope failure in Texas, Missouri, Kansas, and Idaho in the United States. The RPP provides additional resistance along the potential slip surface when it is driven into the slope and increases the factor of safety. RPPs are fabricated from recycled plastics and waste materials (i.e. polymers, sawdust, and fly ash), and is nondegradable in nature. It is found to be very useful and beneficial engineering materials for civil engineering infrastructure projects. The cost-effectiveness of using any engineering material largely …

Evaluation Of Fire-Affected Concrete Structures By Non-Destructive Testing Methods, Upal Mohammad Towfiqul Quadir

Civil Engineering Dissertations

Fire hazard on concrete structures has been a significant concern around the world. After a fire hazard, the crucial part is the evaluation of the fire-affected concrete for strengthening or demolition. For evaluation of a fire-affected concrete structure, Non-destructive Testing (NDT) methods would certainly be a more viable option than the destructive testing methods. Until now, no specific code was developed for quantifiable evaluation of fire-affected concrete with NDT. To develop the method for Non-destructive Evaluation (NDE) of fire-affected concrete, 8 small-sized (4 in x 4 in x 15 in) and 32 medium-sized (8 in x 8 in x 36 …

Effect Of Chicken Manure On Methane Production From Msw In Lab Scale Anaerobic Reactors, Md Tauhidul Islam

Civil Engineering Theses

One of the major problems of urbanization is the production of a huge amount of Municipal Solid Waste. The cities and metropolitan areas are generating more and more solid waste and these wastes are filling up the landfill rapidly. Creating new landfills after a few years is not a solution as there is not much space in urban areas. Moreover, making the landfills far away from cities is not economically viable as longer hauling distance increases the cost. In this scenario, Bioreactor landfill is a viable solution to this problem. Bioreactor landfills can save a lot of space and it …

Development Of A Flexible Pavement Design Protocol For The Uae Based On The Mechanistic-Empirical Pavement Design Guide, Ammar Hassan Alalkim Alzaabi

Civil Engineering Dissertations

The Ministry of Infrastructure Development in the UAE has used the AASHTO 1993 Pavement Design Guide for the design of new flexible pavement structures for many years. An improved pavement design method, called the Mechanistic-Empirical Pavement Design Guide (MEPDG) was developed by AASHTO in their effort to update the empirical method used in 1993 Guide. The project was initiated by the National Cooperative Highway Research Program (NCHRP) 1-37A project. It is based on mechanistic-empirical analysis of the pavement structure to predict the performance of the pavements subject to pavement structure and materials, traffic and environmental conditions. The development allowed for …

Enhancements Of Shear Tests For Asphalt Concrete, Yazeed Suleiman Jweihan

Civil Engineering Dissertations

The measurement of the fundamental shear properties of asphalt mixes is imperative to the improvement of modelling of rutting development in asphalt concrete. The Duplicate Shear Tester (DST) is a recent device developed at the University of Texas at Arlington as a replacement to the Superpave Shear Tester (SST). It measures the average shear properties of two asphalt concrete specimens at the same time. It has ability to perform the two common SST tests: the FSCH and RSCH in according to the standard test method AASHTO T-320. Although the DST has successfully satisfied the objectives of being a reliable, inexpensive …

Impacts Of Construction Material Delay In Iraq, Omar Raad Abdullah

Civil Engineering Theses

The construction industry is considered one of the most important industries in Iraq. It is well known that most construction projects in this country can experience missed deadlines and cost overruns or both. The main objectives of this study are to evaluate the impact of construction material shortages and to determine the most important problems causing these shortages in Iraq. Above objectives are achieved through a literature review and a survey, which include a questionnaire used to assess the perceptions of the main participants involved in the construction of different types of projects, such as infrastructure, residential, highways and medical …

Synthesis Of Metakaolin-Based Geopolymer And Its Performance As Sole Stabilizer Of Expansive Soils, Rinu Ann Samuel

Civil Engineering Dissertations

Expansive soils have been stabilized using conventional soil stabilizers such as lime and cement for many decades. These conventional stabilizers form cementitious productions that enhance the strength properties and reduce the swelling and shrinkage potential of expansive soils. However, the energy-intensive production operations of conventional soil stabilizers release substantial amounts of harmful greenhouse gases into the atmosphere. In addition, conventional soil stabilizers are also prone to durability issues, which make them somewhat ineffective as long-term solutions. Furthermore, the use of calcium-based stabilizers cause excessive swelling and shrinkage in sulfate-bearing subgrade soils due to the formation of highly expansive minerals like …

Evaluation Of The Structural Performance Of Bridge Mse Retaining Walls, Zaid Sm Momani

Civil Engineering Dissertations

Mechanically Stabilized Earth (MSE) walls have been used extensively since the first MSE wall constructed in California in the early 70’s. MSE walls proved that they are reliable, cost-effective, aesthetically pleasing, and easily constructible. However, the design criteria of an MSE wall does not always incorporate the comprehensive behavior. A reasonable number of MSE walls do not perform as expected; a few experienced catastrophic failure. The current study was inspired by multiple MSE walls showing excessive movement of the precast panels in Fort Worth and Hurst, Texas. Three most critical MSE walls were selected for this study. The main focus …