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A Study On Early Age Properties Of Concrete For Precast And 3d Printing, Debalina Ghosh

Doctoral Dissertations

Concrete is the second-most consumed material, leading the global Portland cement production of 4.1 billion tons in 2020 and 5-8% of global Carbon dioxide (CO₂) emission annually. As with any other material and practice, the construction industry is also ever-changing to meet market demand, evolving technology, and resource limitation. In the case of concrete construction, one of the main concerns is the lack of automation. In the last few decades, some new construction methods have risen to address this concern. Some of these economic and successful practices are precast construction, self-compacting concrete (SCC), and 3D printing of concrete(3DPC). …

Evaluating Impacts Of Shared E-Scooters From The Lens Of Sustainable Transportation, Nitesh Shah

Doctoral Dissertations

As the popularity of shared micromobility is increasing worldwide, city governments are struggling to regulate and manage these innovative travel technologies that have several benefits, including increasing accessibility, reducing emissions, and providing affordable travel options. This dissertation evaluates the impacts of shared micromobility from the perspective of sustainable transportation to provide recommendations to decision-makers, planners, and engineers for improving these emerging travel technologies.

The dissertation focuses on four core aspects of shared micromobility as follows: 1) Safety: I evaluated police crash reports of motor vehicle involving e-scooter and bicycle crashes using the most recent PBCAT crash typology to provide a …

Fundamental Investigation Of Interaction Between Moisture And Asphalt-Aggregate Systems, Rui Xiao

Doctoral Dissertations

Moisture-induced damage is one of the most common forms of flexible pavement distress which directly causes or exacerbates pavement failure. The intrusion of moisture into the asphalt pavements reduces the overall mechanical properties of the locking structures and gives rise to one or more of the visible forms of distress such as raveling, stripping, permanent deformation and fatigue cracking. This doctoral study is aimed at understanding the detrimental action of water on the asphalt-aggregate systems and the damage mechanism by multi-technique investigation. A thermodynamics framework was considered to characterize the properties of asphalt mix ingredients as well as the engineering …

Emerging Trends In Bus Ridership In The United States, Abubakr Ziedan

Doctoral Dissertations

Public transit ridership in the United States was declining even before the COVID-19 pandemic. Many different factors affect transit ridership levels, and the recent declines in ridership across the country make it critical to assess which factors are causing declines and which may help to increase ridership. Therefore, this dissertation seeks to quantify the impact of three emerging factors on bus ridership: shared electric scooters (e-scooters), new fare payment technologies and policies, and the COVID-19 pandemic.

This dissertation analyzed the impacts of shared e-scooters on bus ridership. This was investigated at the route level in Louisville, KY, and Nashville, TN, …

A Study Of Readiness For Transportation Electrification And Automation Focusing On Safety And Future Adoption, Steve Lee

Doctoral Dissertations

Transportation electrification and automation are growing societal trends and considered promising pathways to enhance the safety, mobility, efficiency, and sustainability of the surface transportation system. At this early stage of transportation electrification and automation, one of the most critical issues is whether and to what extent people are willing to adopt electric vehicle (EV) and automated vehicle (AV) technologies in the future. Another critical issue, especially concerning transportation automation, is how to thoroughly ensure the safety of automated driving performance to resolve safety concerns about AVs, which is one of the key challenges to AV adoption. In this regard, the …

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 …

Abiotic And Biotic Degradation Of Bisphenols, Yanchen Sun

Doctoral Dissertations

Bisphenol A (BPA), as well as its substitutes bisphenol S (BPS) and bisphenol AF (BPAF), are high production volume chemicals and potential endocrine disruptors. The oxidized manganese (Mn) species, soluble Mn(III) and solid Mn(IV) (i.e., MnO₂), are typically generated in Mn-cycling driven by Mn-oxidizing bacteria and Mn-reducing bacteria. MnO₂ is a strong oxidant capable of oxidizing a variety of organic contaminants including bisphenols. Soluble Mn(III) commonly occurs near oxic-anoxic interfaces and is an important environmental oxidant. Mn(III) is also associated with both biogenic and synthesized MnO₂. However, the effect of Mn(III) on the degradation of …

Investigating The Blending Mechanism And Strength Development Of 100% Hot In-Place Recycled Asphalt Mixtures, Yuetan Ma

Doctoral Dissertations

The current tendency in the asphalt paving industry is to increase the utilization of recycled asphalt pavement (RAP). Hot in-place recycling (HIR) is a promising approach to consume 100% RAP from the existing pavement for pavement surface rehabilitation in the field. However, some concerns remained regarding the utilization of HIR techniques in pavement rehabilitation: 1. Whether it is cost-effective to apply the in-place recycling techniques to pavement rehabilitation compared to the conventional HMA surface milling & filling? 2. How to improve the performance of the asphalt mixtures with HIR technique? 3. How much RAP binder can be available for coating …

Deep Learning-Based Robotic Perception For Adaptive Facility Disinfection, Da Hu

Doctoral Dissertations

Hospitals, schools, airports, and other environments built for mass gatherings can become hot spots for microbial pathogen colonization, transmission, and exposure, greatly accelerating the spread of infectious diseases across communities, cities, nations, and the world. Outbreaks of infectious diseases impose huge burdens on our society. Mitigating the spread of infectious pathogens within mass-gathering facilities requires routine cleaning and disinfection, which are primarily performed by cleaning staff under current practice. However, manual disinfection is limited in terms of both effectiveness and efficiency, as it is labor-intensive, time-consuming, and health-undermining. While existing studies have developed a variety of robotic systems for disinfecting …

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 …

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 …

Using Heuristic Methods And Machine Learning To Enhance The Positional Accuracy Of Historical Geospatial Datasets, Pankaj Mani Dahal

Doctoral Dissertations

The recent availability of multiple geospatial datasets can be attributed to advancements in location-based technologies. The merging of various datasets, commonly known as conflation, is essential to strengthening the content of existing datasets by integrating information from various sources. However, complexities arise when these merged datasets contain distinct representations of the same real-world entities with differing accuracy, projections, data structure, and consideration of details. Although conflation has been an interest to researchers for a long time, the existing methods do not cater to the specific needs of some datasets. For example, historical datasets have lower resolution with richer attribute information, …

Environmental Design And Optimization Of Modular Hydropower Plants, Colin Sasthav

Doctoral Dissertations

This research aimed to understand the pathways to cost-effective and sustainable low-head hydropower. Designing viable hydropower projects requires optimization across many economic, environmental, and social outcomes. However, existing run-of-river hydropower design models often focus on economic performance and customizing technologies for high-head diversion schemes. Standard modular hydropower is a new design approach that uses standardized rather than custom-designed technologies to achieve economies of scale. Oak Ridge National Laboratory established a conceptual outline for module classes based on functions, such as generation modules and fish passage modules, but further research was needed to identify how modules should be selected and operated …

Analyzing Appropriate Policy Factors To Stimulate Zero Emission Vehicle (Zev) Population Growth In California To Achieve The State’S Overall Climate And Environmental Goals, Toks A. Omishakin

Doctoral Dissertations

The objective of this dissertation research is to assess critical policy factors that will need to be adjusted to stimulate significant increases in the adoption of Zero-Emission Vehicles (ZEV) in California to support the state's aggressive climate and environmental goals. Currently, California in comparison to the other 49 states has the United States' worst Greenhouse Gas Emissions (GHG) coming from its transportation sector. Also, within the state, transportation is ahead of all other economic sectors, including agriculture, electricity generation, and even industrial pollution in creating poor air quality. California in recent years has set aggressive targets to both decreases GHG’s …

University Of Tennessee Outdoor Cultural And Recreational Center, Meredith King

Chancellor’s Honors Program Projects

No abstract provided.

University Of Tennessee Outdoor Cultural And Recreational Center, Meredith King

Chancellor’s Honors Program Projects

No abstract provided.

Hydropower System Design In Nazarét, Panama, Claudia M. Bible, Matthew J. Tolson, Andrew Houser, Aj Condra, Nathan Smith

Chancellor’s Honors Program Projects

No abstract provided.