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Full-Text Articles in Engineering

Designing And Advancing Contrast Agents For Ultrasound-Switchable Fluorescence Imaging, Yang Liu Dec 2021

Designing And Advancing Contrast Agents For Ultrasound-Switchable Fluorescence Imaging, Yang Liu

Bioengineering Dissertations - Archive

Fluorescence imaging is a remarkable tool for molecular targeting and multicolor imaging, but it suffers from poor resolution in centimeters-deep tissues. The recently developed ultrasound-switchable fluorescence (USF) imaging has overcome this challenge and achieved in vivo imaging with the help of the indocyanine green (ICG)-encapsulated poly(N-isopropylacrylamide) (ICG-PNIPAM) contrast agent. As USF imaging advances, there is a great demand to expand the contrast agent bank so that applications can be achieved using different types of contrast agents. Also, there is a need to improve the current ICG-PNIPAM nanogel. This study focused on improving the ICG-PNIPAM nanogel, formulating a novel contrast agent, …

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Assessment Of Stormwater Infrastructure For Mitigating Flooding And Non-Point Source Pollution, Helia Farzaneh Dec 2021

Assessment Of Stormwater Infrastructure For Mitigating Flooding And Non-Point Source Pollution, Helia Farzaneh

Civil Engineering Theses - Archive

Flooding is the top natural hazard impacting coastal and inland communities in Texas. Beyond its destructive impact on rising waters in communities, flooding-induced stormwater negatively affects the quality of large bodies of water. Stormwater runs over land, washes off pollutants, and deposits them into rivers which causes water quality issues in bays and estuaries. In addition, the stormwater increases nutrients, sediments, oxygen-demanding substances, pathogens, and toxins which results in hypoxia in the aquatic system. During the last 5-6 years, severe storm events such as Tropical Storm Beta (September 2020), Tropical Storm Imelda (September 2019), Hurricane Harvey (August 2017) have caused …

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Fire Performance Of Hybrid Fiber Reinforced Self-Consolidating Concrete (Hfrscc) With Glass Pozzolan, Rishabh Kumar Dec 2021

Fire Performance Of Hybrid Fiber Reinforced Self-Consolidating Concrete (Hfrscc) With Glass Pozzolan, Rishabh Kumar

Civil Engineering Theses - Archive

This research focuses on the effects of hybridizing self-consolidating concrete (SCC) using steel (SF) and polypropylene (PP) fibers to study their benefits post-fire exposure. In an attempt to reduce cement’s environmental impacts and to make concrete more sustainable, this research also studies the substitution of cement using glass pozzolan. Limited research has been done in this regard previously, hence this research makes an effort to bridge the enormous knowledge gap. No research has reported tensile, compressive, and flexural strength of SCC with hybrid fibers and glass pozzolan, making this research unique. Based on previous research, the replacement rate of cement …

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Performance Evaluation And Retrofitting Options For An Impact Damaged Non-Composite Steel Girder Bridge, Mohd Mezanur Rahman Dec 2021

Performance Evaluation And Retrofitting Options For An Impact Damaged Non-Composite Steel Girder Bridge, Mohd Mezanur Rahman

Civil Engineering Dissertations - Archive

The Federal Highway Administration (FHWA) has rated about 32% of total bridges in US as structurally deficient or functionally obsolete. One of the most frequently encountered issues for this deficiency is the impact created by cars that exceed the posted clearance for a bridge. Impact damage leads to concrete spalling or cracking, exposed or broken reinforcement/prestressing strands, global and local buckling of the structural member or piercing through the steel girder. For Example, St. Francis Bridge (North Bound) carrying St. Francis Avenue over I-30 east of downtown Dallas was impact damaged by an eighteen-wheeler carrying a heavy-duty wrecker on 29th …

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Theoretical Prediction Of Mechanical Behavior Of Regular And Chiral Honeycombs Based On Loading Of Single Cell., Sai Krishna K. Pinnamaneni Dec 2021

Theoretical Prediction Of Mechanical Behavior Of Regular And Chiral Honeycombs Based On Loading Of Single Cell., Sai Krishna K. Pinnamaneni

Mechanical and Aerospace Engineering Dissertations - Archive

Cellular solids are both naturally occurring and man-made materials depending on the characteristic length or Stochastic manner, these materials exhibit a low-relative density usually 30% than the constituent solid material. Low-density cellular solids have been demonstrating superior mechanical properties in various applications from marine to aerospace and lightweight sandwich structures, which has intrigued in development of novel structured materials. Cellular solids offer great design flexibility ashowows how for the targeted geometric for the application-based industry. These materials are used in sandwich structures and come in the shape of hexagonal. An additional aspect of determining the properties and behavior is by …

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Evaluation Of Geotechnical Parameters Of Soil Using Electrical Resistivity Imaging, Md Asif Akhtar Dec 2021

Evaluation Of Geotechnical Parameters Of Soil Using Electrical Resistivity Imaging, Md Asif Akhtar

Civil Engineering Dissertations - Archive

Electric resistivity imaging (ERI) is an effective non-destructive and rapid measuring way of obtaining continuous soil subsurface resistivity profiles. An ERI technique can be used to identify moisture variations and soil heterogeneities in an area. Thus, ERI is becoming a popular tool in geotechnical (FHWA, 2015)engineering; however, it only provides qualitative information at the current time. Using qualitative images, it is challenging to extract quantitative geotechnical information, such as the type of soil, moisture content, degree of saturation, and atterberg limit, of the subsurface. Several studies have described the electrical resistance of soil as a function of pore fluid conductivity …

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Design For Older Adults – Functional Limitations And Human Factors Engineering, Megumi Sato Hice Dec 2021

Design For Older Adults – Functional Limitations And Human Factors Engineering, Megumi Sato Hice

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Background: Throughout the aging process, people experience changes in functional ability and such changes can happen in physical and mental functions. As a result, older adults develop limitations in their capabilities to perform daily activities. Although many studies have done to identify functional limitations for elderly, many older adults still face negative consequences in daily living conditions due to their functional declines. One of the possible causes may be a lack of feedback or participations of elderly users in the design process. Other reason could be a lack of consideration to identify the needs for a specific task associated with …

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Multi-Parametric And Multi-Objective Optimization Of Heatsinks For Forced And Natural Convection Based Single-Phase Immersion Cooling Of Server, Tushar Rohidas Wagh Dec 2021

Multi-Parametric And Multi-Objective Optimization Of Heatsinks For Forced And Natural Convection Based Single-Phase Immersion Cooling Of Server, Tushar Rohidas Wagh

Mechanical and Aerospace Engineering Theses - Archive

An increase in utility of internet-based services, cloud computing and greater performance demands due to rising AI and ML applications have led to a steep growth in GPU and CPU thermal design power. Efficient thermal management of these processors has become a bottleneck in performance enhancement and corresponding power densification of these components. Furthermore, increased pressure on data center owners to reduce power demands and move towards green computing has exacerbated the data center cooling challenges. Single-phase immersion cooling allows data center owners to not only dissipate the increasing heat fluxes efficiently but can also potentially improve equipment reliability as …

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Study Of Sac Solder Interconnect Parameters In Microelectronic Semiconductor Packaging And Their Effects On Electromigration Failure Mechanisms, Allison Theresa Osmanson Dec 2021

Study Of Sac Solder Interconnect Parameters In Microelectronic Semiconductor Packaging And Their Effects On Electromigration Failure Mechanisms, Allison Theresa Osmanson

Material Science and Engineering Dissertations - Archive

As the shrinkage of electronic devices becomes more appealing, so do their high capacity and efficiency. This demand for ever-shrinking sizes of electronic devices follows the trend predicted by Moore’s Law. To achieve smaller devices, reduced sizes of solder joints, Cu traces, Cu pads, and other components in packages are implemented with tighter tolerances for geometries and layouts. With each incremental change in dimension or material, new reliability challenges emerge. Electromigration (EM), the directional diffusion of atoms with the flow of electrons, has been an inevitable reliability concern for microelectronic device packaging. It is one common failure mechanism in wafer-level …

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Study On Forming Dna-Mediated Nanoparticle Conjugates: Toward Detection Of Covid-19, Chinmay Nitin Afzulpurkar Dec 2021

Study On Forming Dna-Mediated Nanoparticle Conjugates: Toward Detection Of Covid-19, Chinmay Nitin Afzulpurkar

Material Science and Engineering Theses - Archive

The objective of this thesis is to establish a rapid, robust, and reproducible procedure to controllably assemble DNA-functionalized Au nanoparticles (AuNPs) into satellite-shaped nanostructures using sequence-specific DNA hybridization. A target DNA strand with COVID-19 sequence (t-DNA) is used as a bridge to connect a capture DNA functionalized on a 50nm gold nanoparticle (C-AuNP) and a probe DNA functionalized on a 30nm nanoparticle (P-AuNP), creating C-AuNP/t-DNA/P-AuNP conjugates. The C-DNA is complementary to a portion of t-DNA, and P-DNA is complementary to the other portion of t-DNA. The parameters that affect the conjugate formation, including hybridization buffer strength, hybridization temperature, and DNA …

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Change In Sedimentation Regime Due To Bridge Construction Activities: A Field Study At Fm 2478 Bridge Over Wilson Creek, Mckinney, Texas, Subhas Kandel Dec 2021

Change In Sedimentation Regime Due To Bridge Construction Activities: A Field Study At Fm 2478 Bridge Over Wilson Creek, Mckinney, Texas, Subhas Kandel

Civil Engineering Theses - Archive

Bridge construction activities can cause soil disturbances that introduce sediments into a receiving stream and potentially impact its quality and the ecosystem. The impacts of bridge construction activities are studied in two ways: overland erosion and in-stream sediment concentration. For this research, the overland erosion of Wilson Creek in McKinney, Texas was monitored from four erosion plots constructed on its banks, near the bridge construction activities zone. The instream water quality was examined during the construction period by measuring the Total Suspended Solids (TSS) and the turbidity of water samples, and the sediment and water samples were collected and analyzed …

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Carbon Footprint Assessment And Emissions Reduction Strategies For The University Of Texas At Arlington, Dravid Sabarish Villavan Kothai Dec 2021

Carbon Footprint Assessment And Emissions Reduction Strategies For The University Of Texas At Arlington, Dravid Sabarish Villavan Kothai

Civil Engineering Theses - Archive

In the past decade, many universities have started to ascertain their emissions and benchmark their progress towards sustainability and climate control. The University of Texas at Arlington (UTA) is no exception in working toward the goal of carbon neutrality. While UTA continues to grow and transform, its goal is to simultaneously reduce energy intensity and greenhouse gas (GHG) emissions. To this end, the Office of Sustainability is maintaining a carbon inventory for each year to track GHG emissions and provide information to guide reduction strategies. The primary objectives of this research were: 1. To update UTA’s greenhouse gas emissions inventory …

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One Step At A Time: Improving The Fidelity Of Geospatial Agent-Based Models Using Empirical Data, Amy A. Marusak Dec 2021

One Step At A Time: Improving The Fidelity Of Geospatial Agent-Based Models Using Empirical Data, Amy A. Marusak

Industrial, Manufacturing, and Systems Theses - Archive

Agent-based modeling is frequently used to produce geospatial models of transportation systems. However, reducing the computational requirements of these models can require a degree of abstraction that can compromise the fidelity of the modeled environment. The purpose of the agent-based model presented in this thesis is to explore the potential of a volunteer-based crowd-shipping system for rescuing surplus meals from restaurants and delivering them to homeless shelters in Arlington, Texas. Each iteration of the model’s development has sought to improve model realism by incorporating empirical data to strengthen underlying assumptions. This thesis describes the most recent iteration, in which a …

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Constraint Optimal Selection Techniques (Costs) For A Class Of Linear Programming Problems, Tai-Kuan Sung Dec 2021

Constraint Optimal Selection Techniques (Costs) For A Class Of Linear Programming Problems, Tai-Kuan Sung

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

This dissertation describes two classes of Constraint Optimal Selection Techniques (COSTs). An algorithm of each type is developed for solving nonnegative linear programming problems. In addition, geometric interpretations of these new algorithms are given, computational results for some large-scale problems are provided, and directions for future research are discussed.

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Distributed Estimation And Inverse Reinforcement Learning For Multi-Agent Systems, Bosen Lian Dec 2021

Distributed Estimation And Inverse Reinforcement Learning For Multi-Agent Systems, Bosen Lian

Electrical Engineering Dissertations - Archive

Consensus-based distributed Kalman filters for estimation with multiple targets have attracted considerable attention. Most of the existing Kalman filters use the average consensus approach, which tends to have a low convergence speed. They also rarely consider the impacts of limited sensing range and target mobility on the information flow topology. The robustness properties, i.e., gain margins and phase margins of distributed Kalman filtering algorithms are still open problems. In the interactions of controlled dynamical agents, it is often assumed that the agents are "rational" in the sense of attempting to act in such a way as to optimize some prescribed …

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Fast And Parallelizable Numerical Algorithms For Large Scale Conic Optimization Problems, Muhammad Adil Dec 2021

Fast And Parallelizable Numerical Algorithms For Large Scale Conic Optimization Problems, Muhammad Adil

Electrical Engineering Dissertations - Archive

Many real world problems from various application areas such as engineering, finance and operation research can be cast as optimization problems. Generally, the goal is to optimize an objective function under a set of constraints. Traditionally, convex optimization problems are solved by an interior point method (IPM). Interior point methods proved to achieve high accuracy for moderate size problems. However, the computation cost of iterations of these iterative algorithms grows non-linearly with the dimension of the problem. Although interior-point methods are robust and theoretically sound, they do not scale well for very large conic optimization programs. Computational cost, memory issues, …

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Decision Tool For Prioritizing Bridge Repair Or Replacement, Nyoka Amy Florius Dec 2021

Decision Tool For Prioritizing Bridge Repair Or Replacement, Nyoka Amy Florius

Civil Engineering Dissertations - Archive

Bridges are typically damaged/deteriorated due to various factors that require close evaluation to make informed decisions about repair/replacement. There are several aspects of study to evaluate bridges for repair/replacement, such as age, structural adequacy, and frequent usage. Further, bridges which are in poor condition must be identified to mitigate their damage/deterioration and as a result, maintain a safe environment for users. Therefore, to assess the need for funding, state Departments of Transportation are required to evaluate bridges by considering several factors, while prioritizing safety. In Texas, the Highway Bridge Program is responsible for funding bridges which are listed for repair/replacement. …

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Improving Probabilistic Quantitative Precipitation Forecasting Using Machine Learning And Statistical Postprocessing Methods, Mohammadvaghef Ghazvinian Dec 2021

Improving Probabilistic Quantitative Precipitation Forecasting Using Machine Learning And Statistical Postprocessing Methods, Mohammadvaghef Ghazvinian

Civil Engineering Dissertations - Archive

The objective of this research is to address the limitations inherent in conventional statistical postprocessing schemes to generate probabilistic quantitative precipitation forecasts (PQPFs) and improve postprocessed PQPFs quality through introducing new robust statistical models and machine learning frameworks. This dissertation comprises three main elements. First, a new, two-part scheme for creating PQPFs from single-valued quantitative precipitation forecasts is introduced. This scheme, herein referred to as the Mixed-type Non-Homogenous Regression (MNHR), combines the use of logistic regression for estimating rainfall intermittency, and non-homogeneous regression for estimation of additional parameters of the conditional distribution. The performance of MNHR is evaluated relative to …

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Accelerated Performance Degradation Of Single-Phase Cold Plates For Direct-To-Chip Liquid Cooled Data Centers, Lochan Sai Reddy Chinthaparthy Dec 2021

Accelerated Performance Degradation Of Single-Phase Cold Plates For Direct-To-Chip Liquid Cooled Data Centers, Lochan Sai Reddy Chinthaparthy

Mechanical and Aerospace Engineering Theses - Archive

Expanding demands for cloud-based computing and storage, the Internet of Things, and AI-based applications have escalated thermal loads in high-density data centers which necessitated the utilization of more efficient cooling technologies. Direct-to-chip liquid cooling using cold plates has proven to be one of the most efficient methods to dissipate the high heat fluxes of modern high-power CPUs and GPUs. While the published literature has well-documented research on the thermal aspects of direct liquid cooling, a detailed account of reliability degradation is missing. The present investigation provides an in-depth analysis of the reliability degradation of copper cold plates used in high-power …

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Autonomous Guidance Of Unmanned Combat Air Vehicles In Basic Fighter Maneuvering, Jeffery G. Dean Dec 2021

Autonomous Guidance Of Unmanned Combat Air Vehicles In Basic Fighter Maneuvering, Jeffery G. Dean

Mechanical and Aerospace Engineering Dissertations - Archive

Basic fighter maneuvering, or BFM, is the dynamic engagement of two or more aircraft in close-range air combat. The relatively recent introduction of advanced unmanned combat air vehicles (UCAVs) has opened the possibility for automated systems to be players in this arena of air-to-air combat, which has thus far been limited to manned aircraft. In order to design an unmanned system that could fight and win a BFM engagement, the system must include an advanced system for guidance. This dissertation leverages techniques from gain scheduling and incorporates adjustable aimpoint guidance, in order to address the capability for UCAVs to execute …

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Identification Of Resilience Dimensions And Development Of A Decision-Making System To Measure The Resilience Level Of Highway Networks, Thahomina Jahan Nipa Dec 2021

Identification Of Resilience Dimensions And Development Of A Decision-Making System To Measure The Resilience Level Of Highway Networks, Thahomina Jahan Nipa

Civil Engineering Dissertations - Archive

Local as well as national economy and safety depend on the network characteristics of the transportation infrastructures. Destruction of transportation infrastructures causes the direct cost of the reconstruction as well as indirect cost due to loss of mobility. In addition, emergency response and recovery cannot be rendered if access to the affected community is hampered due to a damaged transportation network. Hence, researchers as well national and international organizations are focusing more on a resilience-based approach instead of a traditional recovery-based approach for the transportation infrastructures recently. As a result, there exist a high number of research articles that developed …

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Optimization Of Concrete Pavement Design To Truck Platoon Loading, Mohsen Talebsafa Dec 2021

Optimization Of Concrete Pavement Design To Truck Platoon Loading, Mohsen Talebsafa

Civil Engineering Dissertations - Archive

Transportation is the major contributor toward economic growth and development. In the United States, more than 90% of commodities are transported through the roadway system. Due to the high demand for transportation of goods, there is a high demand in the road freight industry for innovative solutions, and new technologies to improve the sustainability and efficiency of transportation. Truck platooning is one of the most recent technologies with great potential to make road freight safer, cleaner, and more efficient. This technology uses connectivity technologies and automated driving systems to interconnect two or more trucks in a convoy. These automation technologies …

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Evaluation Of Surface Asphalt Mixes Containing Recycled Asphalt Materials In North-East Texas Using Accelerated Pavement Testing, Ana Maria Coca Dec 2021

Evaluation Of Surface Asphalt Mixes Containing Recycled Asphalt Materials In North-East Texas Using Accelerated Pavement Testing, Ana Maria Coca

Civil Engineering Dissertations - Archive

Reclaimed asphalt pavement (RAP) and Reclaimed Asphalt Shingles (RAS) has proved to be an effective alternative to virgin materials in HMA production. Despite that recycling asphalt creates a cycle that optimizes the use of natural resources and sustains the pavement industry, State transportation departments have limited the maximum amount of RAP used in surface layers because of the variability concerns and lack of guidance provided. Even though at the moment, the United Stated recycles more RAP than Europe does in terms of percentage of the total RAP extracted from old pavements, it still lags Japan and other countries. A special …

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Reuse Of Recycled Plastic For Plastic Road Design, Tahsina Islam Dec 2021

Reuse Of Recycled Plastic For Plastic Road Design, Tahsina Islam

Civil Engineering Dissertations - Archive

The ever-increasing volume of traffic and the volatility of daily and seasonal temperatures that are being experienced globally make it essential that the quality and durability of roads are improved. Modifiers can improve the engineering properties of the asphalt mix in these situations. Perhaps plastics are the most promising of all types of modifiers. Since the disposal of plastic waste is a major concern for the environment, recycling of these waste materials is highly desired. The recycling and reuse of plastic waste is a prime example of sustainable waste management. It reduces the buildup of waste in landfills, thereby reducing …

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Effects Of Aging On Mouse Rotator Cuff Tendon Biomechanics, Chinmay Sagar Patwardhan Dec 2021

Effects Of Aging On Mouse Rotator Cuff Tendon Biomechanics, Chinmay Sagar Patwardhan

Bioengineering Theses - Archive

Rotator cuff tendon injuries and tear are caused by overuse, falling, or other accidents, and are often associated with old age. The severe injuries and tear can be debilitating and require nonsurgical treatment for partial tear and arthroscopic surgery for complete tear. The frequent location of injuries and tear are at the enthesis region, the interface where the tendon tissue gradually hardens and merges into the bone. Although aging has been identified as an important factor for rotator cuff tendon injuries and tear, how the mechanical properties of the bone-tendon complex evolve along with age is still a knowledge gap. …

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A Systematic Stakeholder-Driven Framework For Empirical Characterization And Parameterization Of Human Agents For Agent-Based Modeling Of Older Adults' Transportation, Nilufer Oran Gibson Dec 2021

A Systematic Stakeholder-Driven Framework For Empirical Characterization And Parameterization Of Human Agents For Agent-Based Modeling Of Older Adults' Transportation, Nilufer Oran Gibson

Industrial, Manufacturing, and Systems Engineering Dissertations - Archive

Standard of living for health and well-being of oneself and of one’s family is a human right. Vulnerable populations are incapable of maintaining an adequate standard of living due to several reasons, such as financial constraints, racial profiling, health conditions, aging, and the combination of these reasons. To alleviate their vulnerability, the most basic needs of the vulnerable populations must be met. Transportation is the essential link to the resources to address the basic needs of the vulnerable populations. Transportation solutions tailored for vulnerable populations to meet their basic needs have multiple dimensions that require the involvement of all government …

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Replication Data For: Evaluation Of Model Concepts To Describe Water Transport In Shallow Subsurface Soil And Across The Soil–Air Interface, Zhen Li, Kathleen Smits Oct 2021

Replication Data For: Evaluation Of Model Concepts To Describe Water Transport In Shallow Subsurface Soil And Across The Soil–Air Interface, Zhen Li, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

Soil water evaporation plays a critical role in mass and energy exchanges across the land–atmosphere interface. Although much is known about this process, there is no agreement on the best modeling approaches to determine soil water evaporation due to the complexity of the numerical modeling scenarios and lack of experimental data available to validate such models. Existing studies show numerical and experimental discrepancies in the evaporation behavior and soil water distribution in soils at various scales, driving us to revisit the key process representation in subsurface soil. Therefore, the goal of this work is to test different mathematical formulations used …

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Replication Data For: The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Kathleen Smits Oct 2021

Replication Data For: The Effect Of The Top Soil Layer On Moisture And Evaporation Dynamics, Zhen Li, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

Understanding the effect of the top soil layer on surface evaporation and water distribution is critical to modeling hydrological systems. However, the dependency of near-surface soil moisture and fluxes on layering characteristics remains unclear. To address this uncertainty, we investigate how the arrangement of soil horizons affects the evaporation and soil moisture, specifically, the near-surface soil moisture, through the combination of numerical simulations and evaporation experiments. The characteristics of fluxes and moisture from different soil profiles are then used to understand the soil layering conditions. Results show that the top soil layer can significantly affect the evolution of soil moisture …

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Replication Data For: Effect Of Subsurface Soil Moisture Variability And Atmospheric Conditions On Methane Gas Migration In Shallow Subsurface, C. T.K.K. Deepagoda, Kathleen Smits Oct 2021

Replication Data For: Effect Of Subsurface Soil Moisture Variability And Atmospheric Conditions On Methane Gas Migration In Shallow Subsurface, C. T.K.K. Deepagoda, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

A major concern resulting from the increased use and production of natural gas has been how to mitigate fugitive greenhouse gas emissions (predominantly methane) from natural gas infrastructure (e.g., leaky shallow pipelines). Subsurface migration and atmospheric loading of methane from pipeline leakage is controlled by source configurations and subsurface soil conditions (e.g., soil heterogeneity and soil moisture) and are further affected by atmospheric conditions (e.g., wind and temperature). However, the transport and attenuation of methane under varying subsurface and atmospheric conditions are poorly understood, making it difficult to estimate leakage fluxes from methane concentration measurements at and above the soil …

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Stiffness Degradation In Fatigue Life Of Composites Using Dielectric State Variables, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Minhazur Rahman, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider Oct 2021

Stiffness Degradation In Fatigue Life Of Composites Using Dielectric State Variables, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Minhazur Rahman, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

Composite materials are widely used in aerospace and automotive structures for decades and over the years the community has gained a better understanding of the damage and failure modes of composites under fatigue. In this article, a dielectric characterization methodology for in-situ monitoring of composites under fatigue environments is proposed. A novel method of measuring the dielectric state variables in Broadband Dielectric Spectroscopy (BbDS) using Extremely Conductive Silver Epoxy Adhesive (ECSEA) paste is presented. These dielectric state variables serve to identify the precursor of the beginning of the end of life of the composite material under fatigue loading. The reliability …

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