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Articles 17191 - 17220 of 40073

Full-Text Articles in Civil and Environmental Engineering

Sustainable Reuse Of Fly Ash To Mitigate Landfill Methane, Sharon Priyadarshini May 2016

Sustainable Reuse Of Fly Ash To Mitigate Landfill Methane, Sharon Priyadarshini

Civil Engineering Theses - Archive

According to US, EIA 2014 coal alone produces nearly 40% of electricity more than another source in US. Out of the 110 million tons of Coal combustion by-products (CCBs) generated per year as a result of coal combustion, 47% is reused whereas 53% is stored on-site or sent to landfills. There are a number of adverse economic and environmental impacts associated with storage and disposal of coal. Methane (CH4) is a powerful greenhouse gas (GHG), contributing 32% of current climate forcing (US EPA, 2015). Landfill gas comprises of 50-55% CH4 and 40-45% CO2. Global warming potential of CH4 is 28 …


Air Dispersion Modeling Of Multiple Natural Gas Well Pads At Different Terrain Conditions And Determination Of Inverse Distance Weighting Function Exponent, Fatemeh Khalaj May 2016

Air Dispersion Modeling Of Multiple Natural Gas Well Pads At Different Terrain Conditions And Determination Of Inverse Distance Weighting Function Exponent, Fatemeh Khalaj

Civil Engineering Theses - Archive

Natural gas production and development has been widely spreading all over the United States. Texas has been leading the nation in natural gas production by holding approximately twenty three percent of the nation’s natural gas reserves. However, natural gas exploration, drilling, production and distribution process have impacts on air quality and human health. The emissions from natural gas processes could be categorized as volatile organic compounds (including Hazardous Air Pollutants), methane, carbon monoxide, nitrogen dioxides, particulate matter and some other minor emitted pollutants, which have the potential of causing serious health problems and also impact air quality from an environmental …


Safety Aspects Of Bicyclists In A Connected Vehicle Environment, Ajaykumar Patil May 2016

Safety Aspects Of Bicyclists In A Connected Vehicle Environment, Ajaykumar Patil

Civil Engineering Theses - Archive

The revival in the number of bicyclists, bike infrastructure investments and bike policies in the U.S. in the last two decades has escalated the importance of bicycling as a mode of transportation. With the proliferating role of the bicycle mode, bike fatalities continue to grow, too. In response to the increase in fatalities and crashes caused by human driven vehicles, the automobile industry and governments seek to develop autonomous vehicles that can address most of the human related crash causes. While increasing safety remains the primary goal of autonomous vehicles (AV) innovation, the difficulty of bicyclist and pedestrian detection using …


Improving Hydrologic Prediction For Large Urban Areas Through Stochastic Analysis Of Scale-Dependent Runoff Response, Advanced Sensing And High-Resolution Modeling, Amir Norouzi May 2016

Improving Hydrologic Prediction For Large Urban Areas Through Stochastic Analysis Of Scale-Dependent Runoff Response, Advanced Sensing And High-Resolution Modeling, Amir Norouzi

Civil Engineering Dissertations - Archive

Due to urbanization and climate change, large urban areas such as the DallasFort Worth Metroplex (DFW) area is vulnerable not only to river flooding but also flash flooding. Due to the nonstationarities involved, projecting how the changes in land cover and climate may modify flood frequency in large urban areas is a challenge. Part I of this work develops a simple spatial stochastic model for rainfall-to-areal runoff in urban areas, evaluates climatological mean and variance of mean areal runoff (MAR) over a range of catchment scales, translates them into runoff frequency as a proxy for flood frequency, and assesses its …


Structural Retrofit Of Reinforced Concrete Circular Columns Using Cfrp, Ahmed Haider Mohiuddin May 2016

Structural Retrofit Of Reinforced Concrete Circular Columns Using Cfrp, Ahmed Haider Mohiuddin

Civil Engineering Theses - Archive

Fiber reinforced polymer (FRP) composites have developed numerous applications in the field of Civil Engineering, mostly because of their beneficial properties like high strength-to=weight ratio and high corrosion resistance. This study presents an easy and expedient finite element (FE) able to accurately estimate the axial load carrying capacity of reinforced concrete (RC) circular columns confined with externally bonded carbon fiber reinforced polymer (CFRP) sheets. The element is able to model collapse due to concrete crushing. The FE generated in this study is used the load carrying capacity of CFRP confined RC columns subjected to concentric loading. Constitutive models for materials …


Analysis And Modeling Of Pedestrian Walking Behaviors Involving Individuals With Disabilities, Mohammad Sadra Sharifi May 2016

Analysis And Modeling Of Pedestrian Walking Behaviors Involving Individuals With Disabilities, Mohammad Sadra Sharifi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Walking facilities like walkways and stairs are important infrastructures which must be designed to effectively accommodate the behavior of pedestrians. Heterogeneity in pedestrian composition is one important factor generally overlooked in walking facility design guidelines and handbooks. While individuals with disabilities constitute a significant portion of the population in the United States, they are often overlooked due to lack of available data. To remedy this, large scale controlled walking experiments were performed at Utah State University (USU) to study the walking behavior of various types of individuals with disabilities (including vision and mobility impairments) in different walking environments. These environments …


Laboratory Modeling Of Piping Initiation Behavior Through Constricted Outlet, Ibrahim Ahmed Abdelmotelb Ibrahim May 2016

Laboratory Modeling Of Piping Initiation Behavior Through Constricted Outlet, Ibrahim Ahmed Abdelmotelb Ibrahim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Backward erosion piping is a type of internal erosion. It occurs beneath water structures as a result of seepage force. It needs two conditions to take place; 1) sufficient hydraulic head to drive the seepage force, and 2) cohesive layer overlies the sand layer and this will lead to concentration of flow. Many researches were done in the past in an attempt to predict the critical gradient. But it was just taking into account the buoyant unit weight which found in recent research that piping can occur at much lower values than was predicted. And other researches were too conservative …


Partially Closed Valve Effects On Electromagnetic Flow Meter Accuracy, Jordan Clark Jarrett May 2016

Partially Closed Valve Effects On Electromagnetic Flow Meter Accuracy, Jordan Clark Jarrett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As the need to manage water resources increases, the ability to accurately measure use becomes crucial. In industry, measurement inaccuracies can cost either the
supplier or consumer large amounts of money or even result in a depleted resource. Generally, flow meters need a flow profile to be fully developed so to optimize
measurement accuracy.

In order to produce accurate measurements, most flow meters require a straight section of pipe immediately upstream of the meter. The straight pipe helps to develop the flow profile and produces flow conditions that are as ideal as possible. In many field installations, space restrictions lead …


An Analysis Of Airborne Data Collection Methods For Updating Highway Feature Inventory, Yi He May 2016

An Analysis Of Airborne Data Collection Methods For Updating Highway Feature Inventory, Yi He

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Highway inventory plays an important role in highway management. Governments and agencies have been employing different kinds of methodologies for highway inventory. Existing methodologies include field inventory, photo/video log, integrated global positioning system (GPS)/ global information system (GIS) mapping, aerial/satellite photography, terrestrial light detection and ranging (LiDAR), mobile LiDAR, and airborne LiDAR. Each has advantages and disadvantages as well as limitations in collecting road inventory data. This paper mainly focused on the application of airborne data collection method.

Four highway sections in Utah were mapped in this experiment: one section on Interstate 84 (I-84), two sections on Interstate 15 (I-15 …


Quantifying The Removal Of Trichloroethylene Via Phytoremediation At Hill Air Force Base, Utah Operational Unit 2 Using Recent And Historical Data, J. Oliver Diamond May 2016

Quantifying The Removal Of Trichloroethylene Via Phytoremediation At Hill Air Force Base, Utah Operational Unit 2 Using Recent And Historical Data, J. Oliver Diamond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Trichloroethylene (TCE) is a carcinogenic, chlorinated volatile organic compound that was commonly used as a degreasing solvent for aircraft maintenance at many US Air Force bases. Past improper disposal of TCE has resulted in contaminated groundwater plumes surrounding many of these facilities. Phytoremediation, defined as the use of plants and their associated microorganisms to stabilize or remove contamination, has been implemented as part of a TCE groundwater cleanup effort at Travis Air Force base near Sacramento, CA and is being considered as a remediation option at other bases. Volatilization of TCE from leaves and the surface of the soil near …


Developing A Method For Quantifying Nitrogen Transformation Rates Using In Situ Benthic Chambers Dosed With Isotopically Labeled Nitrate, Chelsea A. Stewardson May 2016

Developing A Method For Quantifying Nitrogen Transformation Rates Using In Situ Benthic Chambers Dosed With Isotopically Labeled Nitrate, Chelsea A. Stewardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen, a nutrient required for biological growth, is a common water quality parameter of concern as too much nitrogen can cause a strain on aquatic environments and even death of plants and animals. One way high levels of nitrogen are introduced into aquatic systems is by anthropogenic sources such as effluent from water reclamation facilities. A method was designed to observe the fate of nitrogen and measure the rates of its transformation into different nitrogen species within a stream receiving the effluent from the Silver Creek Water Reclamation Facility in Park City, Utah.

Sealed chambers were designed and installed along …


Developing More Efficient Mechanically Stabilized Earth (Mse) Wall Reinforcements, Matthew J. Rahmeyer May 2016

Developing More Efficient Mechanically Stabilized Earth (Mse) Wall Reinforcements, Matthew J. Rahmeyer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The most common shape for metallic reinforcement in Mechanically Stabilized Earth (MSE) walls is a rectangular strip. The amount of force required to pull the reinforcement out of the wall versus how much steel is required is well balanced.

This study shows that a metal round bar can be altered, either by bending into various geometries or welding into crossbars, and provide similar and sometimes higher resistance to pullout than the rectangular strip. This was achieved while reducing the weight per foot of reinforcement of steel required and providing cost saving benefits.


Framework Of Performance-Based Contracting For Chip Seal And Striping Maintenance Activities, Kishor Shrestha May 2016

Framework Of Performance-Based Contracting For Chip Seal And Striping Maintenance Activities, Kishor Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the United States, there are more than four million miles of road network and new roads are being constructed every year. Most of the road networks were constructed more than two decades ago. Therefore, the age of the majority of the pavement inventory has exceeded original design life. This results in increased work load for the maintenance division of the state Departments of Transportation (DOTs). To maintain the road system, state DOTs use In-House or outsource maintenance works to private contractors using Method Based Contracting (MBC), or Performance Based Contracting (PBC), or any combination of these three. Literature reviews …


Sustainability Assessment Of Recycled Asphalt Mixtures In Texas, Reza Saeedzadeh May 2016

Sustainability Assessment Of Recycled Asphalt Mixtures In Texas, Reza Saeedzadeh

Civil Engineering Dissertations - Archive

The pavement practitioners use more recycled materials in asphalt mixtures in order to compensate for the high price of petroleum products and save the limited resources of virgin materials. Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) have been in wide use in asphalt mixtures for several decades. Public perception on the utilization of recycled materials is that the mixtures become more cost effective and more environmental friendly. This is true when the initial stage of construction of pavements is assessed. However, a mixture that costs less and/or burdens the environment less at the beginning may require more frequent …


Simulation Of Conservation Practice Effects On Water Quality Under Current And Future Climate Scenarios, Carlington W. Wallace May 2016

Simulation Of Conservation Practice Effects On Water Quality Under Current And Future Climate Scenarios, Carlington W. Wallace

Open Access Dissertations

Analysis of the effects of implementing different conservation practices, as well as increased levels of conservation practices under existing and projected future climate, will determine if current conservation practice recommendations will be sufficient to maintain soil and water resources. The Soil and Water Assessment Tool (SWAT) was used to study four watersheds of different sizes (CCW = 680 km2, F34 = 183 km2, AXL = 42 km 2 and ALG = 20 km2) located in Northeastern Indiana. The overarching goal of this study was to evaluate the effect of various agricultural practices on runoff and agricultural chemical losses under current …


Removal Of Endocrine Disrupting Compounds From Secondary Municipal Wastewater, Dustin R. Resz May 2016

Removal Of Endocrine Disrupting Compounds From Secondary Municipal Wastewater, Dustin R. Resz

Chemical Engineering Undergraduate Honors Theses

Approximately 1.2 billion people around the world live in areas of physical water scarcity. This could increase to half of the world’s population by 2030 and could displace 24 to 700 million people unless steps are taken to ensure adequate water supply.1 Water scarcity is an escalating issue within the United States, specifically in Western inland states with arid climates. This scarcity is encouraging communities to investigate tertiary level municipal wastewater treatment, allowing for reuse of wastewater. Unfortunately, wastewater contains numerous contaminants that are not regulated by the Environmental Protection Agency (EPA) under the Safe Drinking Water Act (SDWA). Many …


The Influence Of Sediment Characteristics On The Fate Of Steroidogenic Compounds In Aquatic Systems And The Effects On Progesterone Bioavailability In A Target Organism, Jodi L. Sangster May 2016

The Influence Of Sediment Characteristics On The Fate Of Steroidogenic Compounds In Aquatic Systems And The Effects On Progesterone Bioavailability In A Target Organism, Jodi L. Sangster

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

There is growing concern about the biologic effects stemming from steroids in impacted waterways. In aquatic systems, interaction between steroids and sediment influence both contaminant fate as well as subsequent bioavailability to aquatic organisms. The focus of this dissertation research was to gain a better understanding of steroid behavior in aquatic systems based on the physiochemical properties of sediment and to use this knowledge to better understand the biological effects stemming from sediment-associated progesterone exposure. Two natural aquatic sediments, a sand and a silty loam, were selected to represent marked differences in sediments properties. Initially, sorption of 17β-estradiol, estrone, progesterone, …


Microbial Degradation Of Sulfonamide Antibiotics, Rachel Levine May 2016

Microbial Degradation Of Sulfonamide Antibiotics, Rachel Levine

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Certain microbes can transform antibiotics in the environment. However, little is known about the identity of these microbes and their antibiotic biotransformation processes. The objectives of this study were to (1) isolate bacterial strains capable of transforming antibiotics, (2) determine the biotransformation kinetics of antibiotics, (3) characterize the effects of background carbons on the biotransformation kinetics, and (4) identify biotransformation products under various environmental conditions. Sulfadiazine (SDZ) was used as the model antibiotic in this study due to its frequent occurrence in livestock wastes. Surface soil from a cattle feedlot was collected to enrich potential SDZ degrading bacteria. A mixed …


Volume-Change Restraining Effects In Continuous Precast/Prestressed Bridge Girders, Athul Alex May 2016

Volume-Change Restraining Effects In Continuous Precast/Prestressed Bridge Girders, Athul Alex

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

A variety of design and construction practices are feasible when building precast concrete continuous bridges with long spans. Precast, prestressed concrete continuous bridges have been implemented by countries around the world. Although these bridges have been in service for many years, there has been limited verification of the ability of connection to provide the predicted continuity. Subsequently many states in the United States design the girders as simple spans for both dead and live loads without considering any moments developed by the connection. The effect of thermal expansion and contraction is hardly considered in the analysis, even though it is …


The Role Of The Structural Engineer In The Contemporary Design Process, Amanda Yeager May 2016

The Role Of The Structural Engineer In The Contemporary Design Process, Amanda Yeager

Renée Crown University Honors Thesis Projects - All

This capstone is a critical look at the contemporary design process, particularly design competitions, and the role of the structural engineer in that process. Often, the design process for competitions is architect-led with the technical experts entering the process after the major design decisions have been made. As a result, structural requirements and other technical considerations are too often left out of the conceptual design proposals, leading to extensive design changes and costly structural issues to resolve before the structure can be realized. To investigate this issue, a structural analysis of an ambitious winning pedestrian bridge design was conducted. The …


Tracking The Rain: Can We Use Remote In Situ Sensors To Evaluate The Effectiveness Of Green Infrastructure?, Ethan Schafer May 2016

Tracking The Rain: Can We Use Remote In Situ Sensors To Evaluate The Effectiveness Of Green Infrastructure?, Ethan Schafer

Renée Crown University Honors Thesis Projects - All

For decades Onondaga County and the City of Syracuse, New York, have struggled with water quality issues involving combined sewer overflows. These combined sewer overflows and the lack of an appropriate system to mitigate storm water runoff have continually contributed to the degradation of Onondaga Lake and the streams draining into it. To combat the issues presented by combined sewer overflows, Onondaga County implemented the storm water reduction program known as "Save the Rain". The Save the Rain program aims to utilize various forms of green infrastructure to reduce storm water flows into the combined sewer system. Examples of green …


Century-Long Variability And Trends In Daily Precipitation Characteristics At Three Finnish Stations, Masoud Irannezhad, Hannu Marttila, Chen De-Liang, Bjørn Kløve May 2016

Century-Long Variability And Trends In Daily Precipitation Characteristics At Three Finnish Stations, Masoud Irannezhad, Hannu Marttila, Chen De-Liang, Bjørn Kløve

Civil and Environmental Engineering Faculty Publications and Presentations

Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908-2008 from 3 meteorological stations in the south (Kaisaniemi), center (Kajaani) and north (Sodankylä). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation (0 mm < daily precipitation ≤ long-term 50th percentile of daily precipitation more than 0 mm) significantly (p


Emerging Investigators Series: Virus Mitigation By Coagulation: Recent Discoveries And Future Directions, Joe Heffron, Brooke K. Mayer May 2016

Emerging Investigators Series: Virus Mitigation By Coagulation: Recent Discoveries And Future Directions, Joe Heffron, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

Waterborne viruses are widespread and persistent in the environment. Coagulation is an effective process for mitigating viruses in drinking water. This review examines recent studies of virus mitigation by coagulation processes in the context of the latest scientific advances. Virus sorption is impacted by electrostatic forces, as well as the hydrophobic effect, steric hindrance, hydrodynamics and interactions with the water matrix. Organic matter in the water may hinder or enhance sorption, depending on virus structure and environmental factors. In addition to physical separation in flocs, coagulation processes have been shown to inactivate viruses. This review evaluates reports of virus inactivation …


Design And Resistance Factor Calibration Of Pipe Piles In California, Yujie Hu May 2016

Design And Resistance Factor Calibration Of Pipe Piles In California, Yujie Hu

Civil Engineering Theses - Archive

Steel pipe piles, either open ended or close ended, are widely used in the state of California as bridge foundations due to high load bearing capacity, light weight, and outstanding workability. The design methods currently used by Caltrans were developed based on limited field data and are lack of field validations of the recent development of steel pipe piles. In this thesis study, 45 high quality steel pipe pile load tests performed in various soil conditions were collected from Caltrans’ load test data to evaluate available design methods and calibrate the resistance factors of selected design methods. A total of …


Potential Application Of Ultra-High Performance Fiber-Reinforced Concrete With Wet-Mix Shotcrete System In Tunneling, Jean Gamarra May 2016

Potential Application Of Ultra-High Performance Fiber-Reinforced Concrete With Wet-Mix Shotcrete System In Tunneling, Jean Gamarra

Civil Engineering Theses - Archive

In the tunneling industry, shotcrete has been used for several decades. The use of shotcrete or wet-mix spray-on methods allows the application of this method in complex underground profiles and shapes. The need for time efficient spraying methods and constructability for lining coverage opens the door for technologies like steel and synthetic fiber reinforced shotcrete to achieve a uniform and a good quality product. An important advantage of the application of fiber reinforced concrete in shotcrete systems for tunneling is that almost no steel fixing is required. This leads to several other advantages including safer working conditions during excavation, less …


Municipal Composting And Organic Waste Diversion: The Case Of Fayetteville, Arkansas, Michael E. Hoppe May 2016

Municipal Composting And Organic Waste Diversion: The Case Of Fayetteville, Arkansas, Michael E. Hoppe

Biological and Agricultural Engineering Undergraduate Honors Theses

It is estimated that 40% of food is wasted in the United States; representing $165 billion in wasted resources. A vast majority of that wasted food is ultimately placed in landfills where it decomposes and releases harmful greenhouse gases (GHGs). In fact, food waste alone is responsible for 23% of annual methane emissions for the US. This has a huge impact on global climate change due to the potency of methane as a greenhouse gas. Currently only 5% of the food waste produced is recovered across the nation. Source reduction would be the best solution to reducing this food waste, …


Strengthening Of Lightweight Reinforced Concrete Beams Using Carbon Fiber Reinforced Polymers (Cfrp), Tariq Al Jaafreh May 2016

Strengthening Of Lightweight Reinforced Concrete Beams Using Carbon Fiber Reinforced Polymers (Cfrp), Tariq Al Jaafreh

Civil Engineering Dissertations - Archive

This research aimed to investigate the effect of utilizing “Fiber Reinforced Polymer” (FRP) on the light weight concrete beams. The main hypothesis is that such utilization of the FRP will lead to strengthened lightweight beams. The research that has been done on this relationship is somewhat broad in the scope and have mostly focused on the normal-weight concrete. However, only few studies that have considered the light weight concrete. Eight Beams were tested in this research under four point bending test. Two beams were taken as a control beams without any external bonding of Carbon Fiber Reinforced polymer. Another two …


Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones May 2016

Finite Element Modeling Of Shallowly Embedded Connections To Characterize Rotational Stiffness, Trevor Alexander Jones

Theses and Dissertations

Finite element models were created in Abaqus 6.14 to characterize the rotational stiffness of shallowly embedded column-foundation connections. Scripts were programmed to automate the model generation process and allow study of multiple independent variables, including embedment length, column size, baseplate geometry, concrete modulus, column orientation, cantilever height, and applied axial load. Three different connection types were investigated: a tied or one part model; a contact-based model; and a cohesive-zone based model. Cohesive-zone modeling was found to give the most accurate results. Agreement with previous experimental data was obtained to within 27%. Baseplate geometry was found to affect connection stiffness significantly, …


Comparison Of Construction Methods For Building An Underground Freight Transportation In Texas, Niloofar Rezaei May 2016

Comparison Of Construction Methods For Building An Underground Freight Transportation In Texas, Niloofar Rezaei

Civil Engineering Theses - Archive

Freight transportation by trucks constitutes approximately 80% of total freight transportation in Texas and it is expected to approximately double by the year 2040. Social and environmental costs are adverse impacts of moving freights by trucks. Underground Freight Transportation (UFT) significantly reduces these negative impacts and is more sustainable method of freight transportation. UFT includes close-fitting vehicles carrying freight through underground pipelines or tunnels between terminals. The main objective of this research is to compare two construction methods: (1) tunneling using tunnel boring machine (TBM) and (2) tunneling using open-cut. To conduct this research, a comprehensive literature search on various …


Enhancing Productivity By Using Building Information Modeling Applications In Pipeline Construction Projects, Harsha Vardhan Reddy Guduru Penusila May 2016

Enhancing Productivity By Using Building Information Modeling Applications In Pipeline Construction Projects, Harsha Vardhan Reddy Guduru Penusila

Civil Engineering Theses - Archive

Building Information Modeling (BIM) is a technology and associated set of processes to produce, communicate, and analyze building models. BIM is a new concept within the construction industry. The objective of this thesis is to utilize BIM in pipeline construction projects as one of the pioneering steps to reduce rework and delays due to unforeseen conditions. This thesis presents evaluation and recommendations to help pipeline construction industry’s transition from traditional two-dimensional drawings to a BIM management process aiding owners and contractors to develop and implement a basic form of BIM technique to manage their projects. This thesis uses two pipeline …