Digital Commons Network^™

Modular Composite Sandwich Structures For Thermal And Structural Retrofitting Of Existing Buildings, Marc Al Ghazal

Masters Theses

Around 40% of global energy consumption and 30% of worldwide carbon dioxide (CO2) emissions are attributed to buildings. Most of this consumption is dedicated to ensuring thermal comfort. The goal of this research was to develop and field validate retrofit solutions to improve the energy efficiency of buildings. Exterior cladding panels were designed and tested to ensure adequate thermal and structural performance. Sandwich panels (glass fibers reinforced polymer (GFRP) skins and polymeric foam cores) were fabricated using the vacuum assisted resin transfer molding (VARTM) process. Extruded polystyrene (XPS) and polyurethane (PU) foams were compared as core materials through a series …

Performance Evaluation Of Sediment Basin Designs For Highway Construction Sites In Tennessee, Jeffery Cole Emmett Jr

Masters Theses

Performance of three sediment basin designs were tested; they were: 1) the TDEC standard design with a forebay, 2) the TDOT design with an inlet check dam, and 3) the TDOT standard design that does not include an inlet check dam. An 1/17 of an acre scaled physical model sediment basin, was constructed next to an elevated outdoor open flume used to mix known water volumes and sediment mass routed by gravity-flow into the basin. The measurement for performance was simply the percent sediment mass retained in the basin from the total input per experimental run (percent sediment removal). Three …

Joint Failure Probability Of Dams Based On Probabilistic Flood Hazard Analysis, Matthew G. Montgomery

Masters Theses

Probabilistic risk methods are becoming increasingly accepted as a means of carrying out risk-informed decision making regarding the design and operation of structures such as dams. Probabilistic risk calculations require the quantification of epistemic and aleatory uncertainties not investigated through deterministic methodologies. In this hydrological study, a stochastic sampling methodology is employed to investigate the joint failure probability of three dams in adjacent, similarly sized watersheds within the same Hydrologic Unit Code (HUC) 6 basin. A Probabilistic Flood Hazard Analysis (PFHA) framework is used to simulate the hydrologic loading of a wide range of extreme precipitation events across the combined …

Numerical And Experimental Investigation Of Machinery Isolation Featuring Gap-Type Nonlinear Rotational Inertial Mechanisms For Marine Applications, Alexandra C. Shafer

Masters Theses

Transmitted noise and vibration from equipment and machinery is an ongoing and serious priority onboard marine vessels as noise and vibrations interfere with system operations and can compromise the functionality of the vessel. Vibration isolation systems have been widely studied for civil and mechanical applications because of the damage that can occur from extreme vibrations and excessive motion. Conventional vibration isolation systems often include components such as springs and dampers in the isolation layer, but researchers have begun to incorporate other devices including, linear rotational inertial mechanisms (RIMs), often known as inerters, to enhance traditional vibration isolation systems. The inerter …

Structural Steel Connection Design For Tensile Rupture By Advanced Inelastic Analysis, Kaylalyn H. Truman-Jarrell

Masters Theses

Connections are critical in structural steel buildings for transferring forces from member to member. Connections must be designed for safety and to ensure they serve their intended function. Many resources are available to engineers designing connections with common configurations and loads. But connection designers often encounter configurations and loading conditions for which there is little guidance. In these cases, design by advanced inelastic analysis can be advantageous. IDEA StatiCa is a steel connection design software for design by advanced inelastic analysis. In this software, some limit states are captured in the same manner as standard strength equations, while others are …

Dissolved Organic Carbon And The Potential Role To Stream Acidity In The Great Smoky Mountains National Park, Jason R. Brown

Masters Theses

A substantial societal shift towards environmental awareness has focused research efforts on the impacts of pollution on natural landscapes. Improvements to pollutant regulations and technology have resulted in sizeable reductions of atmospheric deposition of anthropogenic acids, especially nitrates and sulfates, which has altered the role of these ions in the environment. As such, understandings of environmental chemistry dynamics have required regular updating.

Through the National Park Service Vital Signs monitoring program, increases in precipitation pH observed in Great Smoky Mountains National Park (GRSM) has been attributed to the reduction of inorganic acid concentrations. Unfortunately, these improvements have not been uniformly …

Design And Experimental Evaluation Of A Small-Scale Buckling Restrained Brace Analog, Lindsay K. Helferich

Masters Theses

In the event of an earthquake, structures experience large lateral loads that can lead to weak story mechanisms and result in premature building collapse. Strongback braced frames (SBF) are a type of seismic force resisting system that aim to evenly distribute horizontal loads up the height of the building to mitigate this failure mechanism. Previous research shows that SBFs are a promising way to better design for seismic demands, but these systems have not been fully explored to best exploit the design space. This work is a part of a project that aims to provide both numeric and experimental verification …

Effect Of Radiation On Bond Behavior Between Concrete And Steel Bar: Development Of Experimental Protocol, Mohammed Abdelrahman

Masters Theses

There is a need to assess the effect of radiation on the behavior of bond strength between steel reinforcement and concrete. However, there is geometrical constraints in the cylindrical capsule which limit the size of concrete samples. Thus, developing a protocol to produce pullout sample and a test setup is needed.

A protocol for fabricating high-precision concrete samples with embedded \#2 steel bar has been developed based on the results of an experimental program. A pullout system has also been developed to investigate the bond activity of concrete and steel. This research looks at two different aggregate sizes 3/8 inch …

Terrestrial Laser Scanning Technology For Measuring Streambank Retreat Along East Fork Poplar Creek And Calculating The Effect On Mercury Release., José L. Martínez Collado

Masters Theses

Mercury (Hg) is a globally distributed inorganic pollutants of human concern. The high toxicity is mainly related to the capacity of Hg species to accumulate and biomagnify along aquatic food webs. Along East Fork Poplar Creek (EFPC), erosion represents the principal mercury input into the local waters, eventually reaching humans through the food chain. This research project aimed to monitor streambank erosion along a mercury-contaminated creek using Light Detention and Ranging (Lidar) technology and erosion pins. A Terrestrial Laser Scanner (TLS) was used to generate high-resolution point clouds from August 2020 to January 2021 across nine streambank locations to detect …

Using Survey Data To Understand Ridesourcing In Tennessee: Who, Where, When, And Why?, Cassidy Kilmer Crossland

Masters Theses

With companies like Uber and Lyft leading the way, ridesourcing has grown and continues to grow in popularity in the United States since its introduction just over ten years ago. While research on this new transportation mode has largely focused on national level trends and studies of large metropolitan areas, little has been written about its impacts in smaller and mid-sized cities and states. This paper aims to understand the socioeconomic characteristics and travel behavior trends of those using ridesourcing in less studied regions, using Tennessee as a case study. This thesis has three parts: a literature review of past …

Quantifying Tree Canopy Contributions To Stormwater Runoff Reductions In Urban Watersheds Of The Southeastern United States, Matthew C. Howard

Masters Theses

Urban stormwater is a major contributor to surface water degradation in the United States, prompting cities to invest in ways to naturally capture, store, and slowly release runoff through “Green Infrastructure” (GI). One often overlooked potential contributors to stormwater management are urban trees, an integral part of a given city’s GI. Interception is of particular interest and describes a tree’s ability to capture and store rainfall, reducing the volume of stormwater that can degrade urban streams during storm events. While rainfall interception for full canopy, forested environments is well studied, limited research is available that characterizes the interception of open-grown …

Bioretention Cell Performance Under Shifting Precipitation Patterns Across The Contiguous United States, Matthew Weathers

Masters Theses

As climate change produces shifts in precipitation patterns, communities will need to understand how the performance of green stormwater infrastructure (GSI) may be impacted. Bioretention cells are one of the most commonly implemented forms of GSI for their ability to reduce peak discharge and filter pollutants and are a vulnerable component of stormwater infrastructure. Projections in future climate indicate that bioretention cells may be at risk of losing their existing function due to deviations in precipitation frequency and intensity. General circulation models (GCMs) downscaled to regional climate models (RCMs) can provide climate change projections at a high spatial resolution but …

Biaxial Behavior And Design Of Steel-Concrete Composite Columns, Amirfarzad Behnam

Masters Theses

Steel-concrete composite columns are efficient structural members that possess significant strength, stiffness, and ductility. Accurate methods of assessing the strength of these members are necessary to realize their benefits. Several design codes rely on the plastic stress distribution method (PSD) for computing the cross-sectional strength of composite columns subjected to axial compression and flexural bending. However, there has been limited validation of this method over the wide range of material and geometric properties and loading conditions to which it is permitted to be applied. The first part of this thesis presents a study of the behavior of short composite columns …

Lagrangian Bedload Movement Prediction Using The Virtual Velocity Approach, Theodoros Kyriakopoulos

Masters Theses

The advances in particle tracking codes in the recent years has made possible to track the intermittent movement of a large number of sediment particles with precision and in an automated way. The present study used this technique to study the velocity of the particle while it is in motion, the length it travels once it gets mobilized until it deposits, and the time it rests once deposited until it gets mobilized again. New modeling equations were developed to predict these quantities for a wide range of flow conditions and sediment sizes. These equations were combined to predict the virtual …

Improving Stream Bank Erosion Estimates By Adjusting The Applied Shear Stress For Different Bank Characteristics, Justin Condon

Masters Theses

Stream bank erosion rates are commonly modeled using the excess shear stress equation ε_r = k_d(τ-τ_c)^a, where the exponent a is assumed to be unity. The coefficient of erodibility k_d, and the critical shear stress τ_c [Tau _c] are properties of the bank soil and the applied shear stress τ [Tau] is a function of the channel geometry and discharge. This equation appears to overstimate bank erosion likely due to effects of channel morphology and bank vegetation, among other factors. The objective of this study was to determine whether …

High-Resolution Timeseries Analysis Of Dynamic Geochemistry: A 27-Well Survey Of Contaminated Groundwater Downstream Of The Former S-3 Ponds, Oak Ridge, Tennessee, Emma Dixon

Masters Theses

Spatiotemporal variability of geochemistry of contaminated groundwater has large implications on overall water quality and ability to respond to remedial applications. Gaining knowledge of how geochemistry changes over time in an area can help establish response trends to changing external conditions like weather and level of contamination. In this study, a spatiotemporal survey was performed on 27 wells at the Y-12 Complex in Oak Ridge, Tennessee. This was completed to measure diurnal fluxes in geochemistry from seasonal changes and extreme weather conditions in three areas of historically different contamination levels from a single point contamination source. Measurements were gathered over …

Modeling Root Causes Of Construction Site Fatalities Using Social Network Analysis, Seifeldeen Omar Eteifa

Masters Theses

In spite of the continuing decrease in accident rates in the US Construction industry, accidents are one of the key factors constraining construction industry in terms of cost and time. Fatality rates in the US are more than other developed countries. Research into accident causation included accident occurrence mechanisms, different levels and types of accident causes as and best practices for accident prevention. These efforts, however, did not focus particularly on fatal accidents and did not prioritize the relationships amongst root causes for accidents. Accordingly, this research’s goal is to quantitatively analyze relationships between fatal accident root causes as well …

In Service Performance Evaluation Of Erosion Prevention Sediment Control Devices, Ali Riza Hangul

Masters Theses

The Erosion Prevention and Sediment Control (EPSC) market continuously expands with the addition of new products based on research and development. While some products may require special equipment for installation, others are installation ready. There have not been any investigations conducted on installation complications and cost to gain feedback from construction field personnel with regard to which practices are performing better and/or are preferred. The objective of this thesis is to further evaluate the current practices from performance and cost perspectives, in order to improve the plans development efficiency for the Tennessee Department of Transportation’ Roadway Design, Environmental, and Operations …

Using Naturalistic Data For Bicycle Safety Analysis: An Application Of Cyclephilly Data To Assess Wrong-Way Riding, Nirbesh Dhakal

Masters Theses

This study focuses on wrong-way riding and associated route-choice determinants of wrong-way riding. I present this application as a case study of the many types of analysis that are possible with emerging naturalistic datasets that are not limited to conventional methods (e.g., vehicle counters). I used a dataset generated from a smartphone application, CyclePhilly, that measures rider location second-by-second in Philadelphia. The dataset covers 12,202 trips by 300 unique CyclePhilly users collected from May 2014 through April 2016. The data also includes information on socio-economics of the rider, as well as cycling experience. I merged this dataset with complementary network …

Enhancing License Plate Matching Algorithm: A New Evaluation Measurement And Threshold Determination, Brandon Cole Whetsel

Masters Theses

The process of license plate matching has continued to improve over the last decade, moving from manually intensive to automated. The text-mining technique of edit distance has been crucial to this improvement. Edit distance is not without limitations, such as determining a threshold, intuitiveness of the measurement, and character length issues.

This paper proposes an alternative evaluation method for determining plate matches. The method utilizes conditional probability rules to calculate the likelihood that two plates are a match. The alternative method is not a replacement for the traditional edit distance calculation, but rather an additional tool for practitioners. Depending on …

Fracture Behavior Of Single Mason Sand Particles Under Uniaxial Compression, Thuy Thanh Trieu

Masters Theses

Tensile strength of granular materials under one-dimensional (1D) compression is often examined because granular materials fracture in many applications where the soil mass experience high compression stresses. Through methods such as 1D compression, three-dimensional (3-D) imaging, and discrete element modeling, researchers had determined that the Weibull distribution is a good model to represent the tensile strengths of granular material and the fracturing strength of granular materials is dependent on mineralogy, morphology, grain-size, loading rate, gradation, coordination number, and moisture content. Uniaxial compression experiments were performed on Mason sand particles retained between US sieve #10 (2 mm) and #20 (0.84 mm) …

A Bug’S Life: Integration Of Anaerobic Digestion And Bioelectrochemical Systems For Enhanced Energy Recovery From Wastewater Solids And Other Waste Substrates, Jeff Ryan Beegle

Masters Theses

Organic waste streams, like domestic wastewater and municipal solid waste, have the potential to be used as feedstocks for biotechnology processes to produce high value products and energy. This thesis investigated the technological, economical, and environmental potential for integrated anaerobic digestion (AD) and bioelectrochemical system (BES) platforms as they were theoretically and physically evaluated for energy recovery from domestic wastewater. The first chapter of this thesis compared the theoretical energy efficiencies of converting waste directly into electricity, using AD and BES alone and in various combinations. This chapter reviewed the experimentally demonstrated energy efficiencies reported in the literature with comparisons …

Particle Morphology And Its Influence On Friction And Dilatancy Of Sands, Karen Carmen Lee

Masters Theses

Particle morphology outlines the general analytical method used to describe soil particles’ structure and shape. The characteristics defining this term include sphericity, roundness, and surface texture. Particle morphology has a significant influence on sand behavior and consequently affects dilatancy and friction. Understanding the relationship between shear strength parameters and particle morphology answers fundamental questions about the mechanics of granular materials in general and has the potential to enhance the development of advanced constitutive models that describe granular materials’ behavior.

Many researchers have reported measurements for sphericity, roundness, and surface texture using both two-dimensional (2D) and three-dimensional (3D) images to analyze …

Evaluation Of The Hot Mix Asphalt Compactability Utilizing The Impact Compaction Method, Pawel Andrzej Polaczyk

Masters Theses

This study investigates possibility of utilizing an accelerometer to evaluate compactability of Hot Mix Asphalt compacted with an impact hammer. For over 50 years Marshall Asphalt Mix Design has been the principal choice for asphalt mix designers around the world. Although the United States has almost entirely moved to Superpave Mix Design, the rest of the world nations still choose the Marshall Method. The investigation was conducted with the accelerometer placed on the falling mass of the Marshall Hammer and acceleration data was stored and analyzed. Data obtained from the accelerometer was filtered and the asphalt mix response after each …

Impact Of Transportation Infrastructure On Stream Water Quality: Contribution From Stormwater Runoff, Andrew James Steinman

Masters Theses

Stormwater runoff is a vital concern to the health of natural waterbodies and ecosystems within urban watersheds. While there is already ample research dedicated to understanding water quality from urban roadways, few of those studies have focused on measuring the dynamics of how stream water quality during storm conditions changes due to increased pollutant load from major urban roadways. With the goal to develop effective water resource management strategies for an impaired tributary watershed, water quality was monitored at four locations within a subwatershed to determine what impact pavement runoff of a major interstate has on the impaired receiving stream. …

Leading Safety Indicators In The Construction Industry: The Case Of Tennessee, Noor Suheil Akroush

Masters Theses

The construction industry has historically suffered from high frequency and severity of accidents, making safety a major concern for all associated stakeholders. To improve safety performance, leading safety indicators have emerged as a more effective alternative to the traditional lagging indicators measured after the occurrence of an incident or accident. These are ex ante assessment of construction behaviors and processes to proactively predict safety breaches.

Prior research has defined and assessed leading safety indicators, but has not yet sufficiently understood their actual current application either at the local and/or regional levels. To this end, this research aims to study, define, …

Exploring The Influence Of Urban Watershed Characteristics And Antecedent Climate On In-Stream Pollutant Dynamics, Laurel Elizabeth Christian

Masters Theses

Understanding pollutant fate and transport in urban watersheds is a challenging endeavor, as heterogeneity of land use, precipitation patterns, and pollutant loadings add complexity to the system. As a result, many currently utilized water quality models exhibit poor performance. One main challenge in urban system modeling is the lack of quality data sets for model development, calibration, and testing, resulting in the need for high quality data collection. Although recent studies have begun to investigate pollutant transport in urban watersheds to aid these models, these studies have focused primarily on the end-of-pipe as the point of interest (i.e. prior to …

Long-Term Health Risk Of Climate Change Associated Surface Pm2.5 Concentration Variation: Multiple Accmip Model Data Under Different Emission Scenarios (Rcp26, 45, 60, 85) And Population Scenarios (Ssp1, Ssp2, Ssp3), Xiufen Zhu

Masters Theses

In this study, multiple models from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) are utilized to derive the global burden of disease of chronic obstructive pulmonary disease (COPD), lung cancer (LNC), and lower respiratory infection (LRI) derived from surface PM_2.5 elevation. Various Representative Concentration Pathways and Shared Socio-economic Pathways scenarios are compared as well as various models to deduct the impact from various scenarios. The time series variation and seasonal variation are also illustrated in this study. Multi-model ensemble was conducted to reduce the deviation in model projection output.

Projection shows increase in the population normalized relative risk …

Bridge Deck Research At The University Of Tennessee: A Summary Thesis, Lindsey Brooke Phelps

Masters Theses

Currently, there has been no compilation of all the research the University of Tennessee has completed on chloride ion penetration in concrete bridge decks. The following thesis is a brief summary of the work that has been completed under Dr. Edwin Burdette’s direction over the last six years along with some additional literature review. The testing consisted of Surface Resistivity and Rapid Chloride Ion Penetration testing. This testing showed that there is, in fact a correlation between the two test methods, though SR testing is much easier to conduct. Considerable testing was completed on bridge decks throughout the state of …

The Use Of Sodium Persulfate In Hydraulic Fracturing Fluids: A Degradation Study Based On Furfural, Katherine Elizabeth Manz

Masters Theses

Hydraulic fracturing has allowed natural gas to become a viable energy source via extraction of unconventional shale reserves, but this process requires an enormous amount of water. To ensure a productive fracture, a proprietary blend of chemical additives is added to the water. In this research, a hydraulic fracturing chemical additive – an enzyme breaking agent – is analyzed for organic components using gas chromatography mass spectrometry. The chemical changes that occur over the course of a fracture are also investigated using one model chemical found in the additive, furfural, in order to help assess the environmental risk that hydraulic …