Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 21421 - 21450 of 196022

Full-Text Articles in Engineering

Reliability Assessment Of 2.5d Heterogenous Integrated Circuits, Cu-Cu Hybrid Bonded Interconnects & Thermo-Mechanical Assessment Of Substrates In Two-Phase Immersion Cooling, Akshay Boovanahally Lakshminarayana Jan 2024

Reliability Assessment Of 2.5d Heterogenous Integrated Circuits, Cu-Cu Hybrid Bonded Interconnects & Thermo-Mechanical Assessment Of Substrates In Two-Phase Immersion Cooling, Akshay Boovanahally Lakshminarayana

Mechanical and Aerospace Engineering Dissertations - Archive

Moore’s law has predicted the growth of semiconductor industry for the last 50 years by providing a template for silicon scaling and homogenous system on chip integration of multiple circuits. Lately, this trend has been declining due to the increased power density and functionality and increasing chip size to accommodate this. Moving forward, heterogeneous integration of chiplets will improve the silicon yield by integrating multiple multi-functional chiplets that are of smaller area onto an interposer or a substrate in 2.5D, 3D or 3.5 D architectures. In this study, computational analysis is done on the impact of design parameters and material …


Towards The Development Of A Unified Synthesis System Framework: Advancement Of Avds Towards A Generic, Multi-Disciplinary, And Multi-Fidelity Aerospace Vehicle Design Environment, Ian Wesley Maynard Jan 2024

Towards The Development Of A Unified Synthesis System Framework: Advancement Of Avds Towards A Generic, Multi-Disciplinary, And Multi-Fidelity Aerospace Vehicle Design Environment, Ian Wesley Maynard

Mechanical and Aerospace Engineering Dissertations - Archive

At the start of any design program for the development of a novel aerospace vehicle, there can be millions of design, mission, and technology trades to be explored. Design software is needed that can modularly adapt itself such that it can be generically applied to a wide variety of aerospace applications. It needs to be automated such that it can ‘stitch’ together and generate synthesis codes using a wide variety of disciplinary methods including geometry, aerodynamics, propulsion, trajectory, weights, stability and control, cost, etc. It should also be able to modularly switch the multi-disciplinary synthesis execution process in the synthesis …


Analysis And Detection Of Cyber Attacks In Multi Vehicle Systems Using Macroscopic Models, Abhishek Kashyap Jan 2024

Analysis And Detection Of Cyber Attacks In Multi Vehicle Systems Using Macroscopic Models, Abhishek Kashyap

Mechanical and Aerospace Engineering Dissertations - Archive

The study of potential cyber-attacks in different domains is an active area of research. Given that systems are becoming more and more interconnected, cyber physical systems that operate infrastructure and/or plants can make these assets more vulnerable and open to different attack vectors. The primary focus of this research is the modeling, analysis and detection of cyber-attacks on platoons of autonomous cars and swarms of UAVs. In this work, we consider scenarios wherein an attacker may hack into a subset of vehicles in a multi-vehicle system and make subtle modifications in their parameters. Due to the interconnected nature of the …


Assessment Of Drainage Characteristics Of Recycled Crushed Concrete Aggregate (Rcca) And Plastic Mix Pavement Base, Amena Begum Jan 2024

Assessment Of Drainage Characteristics Of Recycled Crushed Concrete Aggregate (Rcca) And Plastic Mix Pavement Base, Amena Begum

Civil Engineering Theses - Archive

Recycled Crushed Concrete Aggregate (RCCA) offers a sustainable alternative to natural aggregate in construction, reducing reliance on natural resources and diverting construction and demolition debris from landfills. Similarly, the escalating global plastic waste crisis highlights the need for innovative solutions to address non-biodegradable waste disposal challenges and create opportunities for recycling plastics into value-added applications. This study explores the potential of RCCA mixed with plastic waste, such as HDPE and PP, as a viable substitute for natural aggregates in flexible pavement base layers, with a focus on hydraulic properties and drainage performance to enhance pavement durability.

A comprehensive experimental program …


Exploring The Impact Of Vented Packaging Configurations On Airflow Patterns And Cooling Consistency For Muskmelons In A Cold Storage Environment, Nur Wafidah Roslan, Namasivayam Navaranjan, Zohrah Sulaiman, Naseem Uddin Jan 2024

Exploring The Impact Of Vented Packaging Configurations On Airflow Patterns And Cooling Consistency For Muskmelons In A Cold Storage Environment, Nur Wafidah Roslan, Namasivayam Navaranjan, Zohrah Sulaiman, Naseem Uddin

ASEAN Journal on Science and Technology for Development

The cooling effect of different vented packaging designs was investigated for packed muskmelons fruits in a commercial cold storage condition. Computational fluid dynamics (CFD) simulation and experiments were used. The airflow pattern, heat transfer and temperature profiles were predicted from simulation and analysed. The CFD results reveal an uneven and low efficient airflow distribution inside a commercially used vented packaging (Box A). This resulted slow cooling of the fruits in Box A. Two newly designed packaging (Box B and Box C) showed better airflow distribution around the fruits and cooled them faster than Box A. The design of Box C …


Smes’ Perspectives On The Benefits And Challenges Of Halal Certificate Application In Brunei Darussalam, Kamariah Ismail, Syahnur Farhana Haji Shahlehi, Vivi Nabilah Shaya Jan 2024

Smes’ Perspectives On The Benefits And Challenges Of Halal Certificate Application In Brunei Darussalam, Kamariah Ismail, Syahnur Farhana Haji Shahlehi, Vivi Nabilah Shaya

ASEAN Journal on Science and Technology for Development

The knowledge and research on SMEs and Halal-related studies in Brunei Darussalam are scant. Guided by the principles of Resource-Based View theory, this qualitative study aims to identify the benefits and challenges of Halal certificate application from the perspectives of Bruneian Halal food SMEs, as they obtain the Brunei’s Halal certificate and label. Based on the purposive and snowball sampling, four semi-structured interviews were conducted with business owners and managers in the Halal food industry. Government officials were also in-terviewed to enhance the findings. Thematic analysis, supplemented by secondary data, was employed for a comprehensive understanding. Four themes emerged, covering …


Factors Affecting The Adoption Of Information Technology In Medium And Small Enterprises: A Case Study In Mekong Delta, Vietnam, Thy-Lieu Nguyen-Thi, Duy-Dong Le, Kieu-Chinh Nguyen-Ly, Trung-Tien Nguyen, Mohamed Saleem Haja Nazmudeen Jan 2024

Factors Affecting The Adoption Of Information Technology In Medium And Small Enterprises: A Case Study In Mekong Delta, Vietnam, Thy-Lieu Nguyen-Thi, Duy-Dong Le, Kieu-Chinh Nguyen-Ly, Trung-Tien Nguyen, Mohamed Saleem Haja Nazmudeen

ASEAN Journal on Science and Technology for Development

This research endeavors to discern the determinants influencing the adoption of information technology in the management practices of small and medium-sized enterprises (SMEs) situ-ated within the Mekong Delta region of Vietnam. Leveraging the Unified Theory of Ac-ceptance and Use of Technology (UTAUT), PLS-SEM, and ANN models, this study ranks the pivotal factors that impact the decision to integrate information technology into SME management. The identified factors, in order of significance, encompass (1) Support from State Agencies, (2) Managerial Qualifications, (3) Competitive Landscape, (4) Enterprise Scale, and (5) Employee Qualifications. The investigation encompasses 496 SMEs across the Mekong Delta and evaluates …


Word Prediction Using Dynamic Skip Connections Along With Arabert And Lstm In Arabic Language, Ahad Almalki, Faris Kateb, Rayan Mosli Jan 2024

Word Prediction Using Dynamic Skip Connections Along With Arabert And Lstm In Arabic Language, Ahad Almalki, Faris Kateb, Rayan Mosli

ASEAN Journal on Science and Technology for Development

Natural Language Generation (NLG) plays a crucial role in modern digital tools, including chatbots, virtual support, content suggestions, and tailored marketing, making bots more responsive and reducing the need for human staff. While there's much research on NLG for languages like English, languages like Arabic, Urdu, and Chinese still face challenges. This study examines Arabic NLG's unique aspects, dialects, and word variations. With around 420 million Arabic speakers globally, it's crucial to advance NLG for this language. We compared three models: Long Short-Term Memory (LSTM), a mix of Bidirectional Encoder Representations from Transformers (BERT) and LSTM, and a version that …


Sustainability Innovation, Firm Competitiveness, Export Performance, And Sales Growth: A System Dynamics Approach, Budi Harsanto, Joval Ifghaniyafi Farras, Egi Arvian Firmansyah Jan 2024

Sustainability Innovation, Firm Competitiveness, Export Performance, And Sales Growth: A System Dynamics Approach, Budi Harsanto, Joval Ifghaniyafi Farras, Egi Arvian Firmansyah

ASEAN Journal on Science and Technology for Development

In recent times, the interplay between sustainability innovation, firm competitiveness, export performance, and sales growth has garnered significant attention. Research on sustainable innovation's effects on firm competitiveness, export performance, and sales growth remains limited, especially concerning specific contexts like Halal Micro, Small, and Medium Enterprises (MSMEs). The study proposes to bridge this gap by developing a System Dynamics model that considers firm competitiveness, sales growth, export performance, and sustainable innovation. This research uses the system dynamic method which is carried out in four stages. The first stage, analyzing the system mechanism for sustainable innovation, the second stage, building correlations between …


Thriving In Turbulent Times: The Dynamic Link Between Economic Condition And Fintech Business Lending Success, Nur ‘Asyiqin Ramdhan, Imbarine Bujang, Amirul Afif Muhamat, Ninuk Dewi Kesumaningrum Jan 2024

Thriving In Turbulent Times: The Dynamic Link Between Economic Condition And Fintech Business Lending Success, Nur ‘Asyiqin Ramdhan, Imbarine Bujang, Amirul Afif Muhamat, Ninuk Dewi Kesumaningrum

ASEAN Journal on Science and Technology for Development

This study aimed to understand how FinTech business lending was affected by the pandemic crisis, which caused small businesses to struggle with limited access to funds. During this crisis, demand for alternative financing, like peer-to-peer (P2P) lending, surged. However, P2P lending faces challenges related to information imbalances, especially during crises, when transparency and economic conditions impact investor decisions in Malaysia. We examined factors like platform interest rates, loan duration, investment size, bank lending rates (BLR), inflation, and the crisis using ARDL analysis. Our long-term analysis revealed a significant positive relationship between investment size and P2P lending, while economic conditions had …


Enhancing Phishing Attack Detection Using Explainable Ai: Trends And Innovations, Bhagyashree D. Shendkar, Pankaj R. Chandre, Sulochana Sagar Madachane, Nikita Kulkarni, Sayalee Deshmukh Jan 2024

Enhancing Phishing Attack Detection Using Explainable Ai: Trends And Innovations, Bhagyashree D. Shendkar, Pankaj R. Chandre, Sulochana Sagar Madachane, Nikita Kulkarni, Sayalee Deshmukh

ASEAN Journal on Science and Technology for Development

In the context of escalating cyber threats, phishing attacks continue to pose significant challenges to cybersecurity measures, exploiting human vulnerabilities to gain unauthorized access to sensitive information. Innovative solutions are required because traditional detection methods frequently fail to identify and mitigate these assaults successfully. To improve phishing attack detection, this study makes use of Explainable Artificial Intelligence (AI) tools, which provide decision-making processes with transparency and prediction accuracy. The paper begins by outlining the pervasive nature of phishing attacks in today's digital landscape, emphasizing their detrimental impact on individuals, organizations, and society at large. It then discusses the limitations of …


Characterization Of Adhesive Strength In Metal-Polymer Bonds, Oreoluwa Adeseyoju Jan 2024

Characterization Of Adhesive Strength In Metal-Polymer Bonds, Oreoluwa Adeseyoju

Open Access Master's Theses

Classified information has been deleted.


Analysis Of Performance Deterioration During Prolonged Wakefulness, Aaron J. King Jan 2024

Analysis Of Performance Deterioration During Prolonged Wakefulness, Aaron J. King

Open Access Master's Theses

In a variety of professions, personnel are asked to work extended shifts, straining themselves both physically and mentally. The strain in combination with the prolonged wakefulness can lead to mistakes on the job. This can be problematic for industries where mistakes are associated with high-risk consequences. A few professions that typically work in shifts include nurses, truck drivers, and oil-rig workers to name a few. Pertinent to this study is the performance of operators performing pilot related activities such as driving or monitoring; this is specifically interesting where the risk for failure can result in fatality or serious injury, such …


Investigating The Thermal Multibody Effects In Spherical Inclusions Of A Porous Matrix For Lithium-Ion Batteries, Nicholas Scholz Jan 2024

Investigating The Thermal Multibody Effects In Spherical Inclusions Of A Porous Matrix For Lithium-Ion Batteries, Nicholas Scholz

Open Access Master's Theses

As technology improves, there is a need for better and more efficient energy storage and lithium-ion batteries have emerged as the primary energy storage device. They have positive electrochemical properties, are easily accessible, and rechargeable. However, lithium-ion batteries have been known to fail, leading to research into the failure mechanisms. As some of these failure mechanisms, such as thermal runaway, depend on thermal interactions, this paper aims to investigates thermal multibody effects of spherical inclusions in a porous matrix to gain insight into thermal effects of a realistic lithium-ion battery microstructure. Analytical solutions to this problem, such as Maxwell’s thermal …


Developing An Immunomodulatory Strategy Using Biophysical Cues To Modulate Macrophage Phenotype For Fracture Healing And Bone Regeneration, Harshini Suresh Kumar Jan 2024

Developing An Immunomodulatory Strategy Using Biophysical Cues To Modulate Macrophage Phenotype For Fracture Healing And Bone Regeneration, Harshini Suresh Kumar

Theses and Dissertations--Biomedical Engineering

Chronic inflammation is a major cause of the pathogenesis of musculoskeletal diseases such as fragility, fracture, and nonunion. Studies have shown that modulating the immune phenotype of macrophages from proinflammatory to pro-healing can heal recalcitrant bone defects. Current therapeutic strategies predominantly apply biochemical cues, which often lack target specificity, and controlling their release kinetics in vivo is challenging spatially and temporally. We have developed a magnetic iron-oxide nanocomplexes (MNC)-based therapy for resolving chronic inflammation in the context of promoting fracture healing. Here, we show that MNC internalized macrophages, when coupled with an external magnetic field, can exert an intracellular magnetic …


Relating Temperature, Sleep, And Pathology In Mouse Models Of Alzheimer's Disease, Jun Wang Jan 2024

Relating Temperature, Sleep, And Pathology In Mouse Models Of Alzheimer's Disease, Jun Wang

Theses and Dissertations--Biomedical Engineering

It is well established that sleep plays an important role in Alzheimer’s disease (AD) pathology. There is growing evidence that sleep issues may accelerate AD pathology by interrupting the physiological clearance of amyloid‐β (Aβ) from the brain, which mainly occurs in normal sleep. As the over-accumulation of amyloid‐β (Aβ) is believed to lead the cascade effect that eventually causes neurodegeneration in AD patients, development of therapeutic strategies for improving sleep quality may help slow disease progression. It is well documented that the composition and dynamics of sleep are sensitive to changes in ambient temperature. We therefore developed a sleep enhancement …


Development Of Iron Oxide Nanozyme For Cancer Therapy, Zhongchao Yi Jan 2024

Development Of Iron Oxide Nanozyme For Cancer Therapy, Zhongchao Yi

Theses and Dissertations--Biomedical Engineering

Cancer therapies that leverage reactive oxygen species (ROS) have shown potential for cancer inhibition due to their ability to induce oxidative stress in tumor cells. Iron oxide nanoparticles (IONPs) have garnered significant attention as a promising platform for ROS-dependent disease treatment, owing to their remarkable biocompatibility and Fenton catalytic activity. However, the low catalytic activity of IONPs has been a major hurdle in their clinical translation. To overcome this challenge, IONPs of different compositions are examined for their Fenton reaction under pharmacologically relevant conditions in this work. The results show that wüstite (Fe1-xO) nanoparticles exhibit higher catalytic activity …


Impact Of Augmented Documentation Workflows On Transportation Agency Asphalt Paving Operations: A Qualitative And Quantitative Study, Josh Withrow Jan 2024

Impact Of Augmented Documentation Workflows On Transportation Agency Asphalt Paving Operations: A Qualitative And Quantitative Study, Josh Withrow

Theses and Dissertations--Civil Engineering

e-Ticketing was an intriguing technology to many state transportation agencies (STAs) pre-COVID-19 pandemic but gained significant attention upon arrival of the pandemic due to the contactless nature of the technology. Research completed prior to the pandemic into e-ticketing for asphalt paving primarily identified qualitative benefits and concerns. However, minimal academic literature exists in the post-pandemic era discussing the additional e-ticketing benefits not previously captured which resulted in increased implementation by STAs. This research seeks to address this gap by gathering information from state members of the American Association of State Highway and Transportation Officials Committee on Construction (AASHTO COC), employees …


Estimation Of Mechanical Behavior Of Unsaturated Soils From A Soil-Water Characteristic Curve, Lucas Acheampong Jan 2024

Estimation Of Mechanical Behavior Of Unsaturated Soils From A Soil-Water Characteristic Curve, Lucas Acheampong

Theses and Dissertations--Civil Engineering

The small-strain shear modulus and shear strength are two crucial mechanical behaviors used in the design of geotechnical structures and in the analyses of earth materials subjected to static and dynamic loadings. Traditional testing methods for these parameters are expensive and time-consuming. This research aimed to address these challenges by developing a model based on the inverse relationship between mechanical behavior of unsaturated soils and the soil-water characteristic curve (SWCC). The proposed model integrates a scaling function to align the SWCC with the mechanical property curve. Empirical relationships were established for the scaling function, specifically aligning with the air-entry value …


Geophysical Method Used For The Determination And Prediction Of Soil Strength And Stiffness Parameters, Dabo Adama Jan 2024

Geophysical Method Used For The Determination And Prediction Of Soil Strength And Stiffness Parameters, Dabo Adama

Theses and Dissertations--Civil Engineering

This paper presents the results of an effort to use geophysical measurements such as seismic wave velocities and electrical resistivities to calculate airfield design parameters. The study converts all geophysical measurements to equivalent California Bearing Ratio (CBR) values, comparing CBR values estimated from DCP penetration resistance with CBR values estimated from shear wave velocity and electrical resistivity values. Relationships linking the geophysical measurements to CBR estimates were established using laboratory data and applied to field in-situ measurements. The elastic modulus (E) is the stiffness parameter involved in predicting soil strength and stiffness. This research aims to relate electrical conductivity and …


Analysis And Improvement Of The Kentucky Transportation Cabinet’S Serious Injury And Fatality Program, Arun Subedi Jan 2024

Analysis And Improvement Of The Kentucky Transportation Cabinet’S Serious Injury And Fatality Program, Arun Subedi

Theses and Dissertations--Civil Engineering

Serious Injuries and Fatalities (SIFs) within construction and maintenance industries indicate severe vulnerabilities within workplace safety, and their prevention requires the highest priority. SIFs usually occur due to systemic failures, and proactive steps must be taken to identify and neutralize high-risk scenarios. Kentucky Transportation Cabinet (KYTC) has recently implemented a safety management system called BOOTS, for improving incident reporting and analysis along with SIFs. This study identifies gaps in KYTC's SIF reporting framework and provides analysis on recurring incident trends utilizing the incidents already reported in the system. While current practice in KYTC relies on event-based decision tree when classifying …


Digital Innovation Roadmap For Construction Industry: Bridging The Gap For Future, Nisa Zahin Jan 2024

Digital Innovation Roadmap For Construction Industry: Bridging The Gap For Future, Nisa Zahin

Theses and Dissertations--Civil Engineering

Digitalization has considerable value in the digital transformation of the construction business. It means the use of digital technologies to create revenue, improve business, increase profit and sustainability, and create an environment for digital business whereby digital information is at the core. As such, digital transformation requires skills that involve extracting and exchanging data and analyzing and converting that data into actionable information. In addition to technological solutions, a paramount need is to ensure that the people using these solutions and the processes used to integrate, coordinate between teams, and continuously improve the use of technology are in place. Therefore, …


The Characterization And Nanomechanical Properties Of Microstructurally Complex Systems, Kerry Ann Baker Jan 2024

The Characterization And Nanomechanical Properties Of Microstructurally Complex Systems, Kerry Ann Baker

Theses and Dissertations--Chemical and Materials Engineering

Since the dawn of civilization, the use of metals has played an integral role in the evolution of human society. Over the years, and with the introduction of new engineering and science, we have learned how to combine metals to create new metallic systems. We have expanded our understanding of dealloying and chemical reactions, and, in doing so, we created nanoporous metals. Our use of metals has evolved from basic alloys such as bronze and steel to more complex alloys such as multi-principal element alloys. Nanoporous gold is an advanced metallic system that can be created through the dealloying process. …


Advancing Combinatorial Screening Of Refractory High Entropy Alloys Through Intrinsic Ductility Assessment Via Thin Film Fragmentation Testing, Taohid Bin Nur Tuhser Jan 2024

Advancing Combinatorial Screening Of Refractory High Entropy Alloys Through Intrinsic Ductility Assessment Via Thin Film Fragmentation Testing, Taohid Bin Nur Tuhser

Theses and Dissertations--Chemical and Materials Engineering

High Entropy Alloys (HEAs), also known as Multiprincipal Element Alloys (MPEAs), represent a paradigm shift in alloy design. Unlike traditional practices that limit compositions to the edges of phase diagrams, HEAs exploit equiatomic mixing of five or more elements at the center of phase diagrams to maximize configurational entropy. This unconventional approach exponentially expands the spectrum of potential alloy compositions, rendering conventional experimental methods inadequate for exploring this extensive compositional space.

In response to these challenges, the scientific community has shown a growing interest in high-throughput techniques, encompassing both computational and experimental domains. Particularly, Refractory High Entropy Alloys (RHEAs) have …


Microstructural Investigation Of The Influence Of Geometry On The Mechanical Reliability Of Additively Manufactured Metals, Tracy Connor Varney Jan 2024

Microstructural Investigation Of The Influence Of Geometry On The Mechanical Reliability Of Additively Manufactured Metals, Tracy Connor Varney

Theses and Dissertations--Chemical and Materials Engineering

The adoption of additive manufacturing across a wide range of fields is ever-increasing, allowing for solutions that were previously impossible to achieve. This dissertation demonstrates the wide range of macro- and micro- characterization techniques used to investigate several precipitation strengthened AM alloy systems. While AM allows for nearly unlimited design freedom, this brings along its own issues as the interplay between scan strategy and part geometry is less well known. In this work, a novel thin-wall dogbone geometry was utilized to study one type of complex geometry observed in a large portion of AM focused designs. The mechanical behavior of …


Language Models For Rare Disease Information Extraction: Empirical Insights And Model Comparisons, Shashank Gupta Jan 2024

Language Models For Rare Disease Information Extraction: Empirical Insights And Model Comparisons, Shashank Gupta

Theses and Dissertations--Computer Science

End-to-end relation extraction (E2ERE) is a crucial task in natural language processing (NLP) that involves identifying and classifying semantic relationships between entities in text. This thesis compares three paradigms for end-to-end relation extraction (E2ERE) in biomedicine, focusing on rare diseases with discontinuous and nested entities. We evaluate Named Entity Recognition (NER) to Relation Extraction (RE) pipelines, sequence-to-sequence models, and generative pre-trained transformer (GPT) models using the RareDis information extraction dataset. Our findings indicate that pipeline models are the most effective, followed closely by sequence-to-sequence models. GPT models, despite having eight times as many parameters, perform worse than sequence-to-sequence models and …


Optoelectrical Properties And Photostability Of Cspbbr3 Quantum Dots: Effects Of Dopants And Ligands, Md Shad Bin Salam Jan 2024

Optoelectrical Properties And Photostability Of Cspbbr3 Quantum Dots: Effects Of Dopants And Ligands, Md Shad Bin Salam

Theses and Dissertations--Chemical and Materials Engineering

Metal halide perovskite QDs have a great potential for displays and lighting because of their exceptional optoelectronic characteristics associated with quantum confinement effect. However, the stability in the environment during the applications of halide perovskite QDs remains a significant challenge, impeding their practicality and lowering their commercial scalability. High-temperature methods are well-established for producing doped perovskite QDs, the influence of room-temperature synthesis on thermal, size-dependent optical properties, and long-term stability remains inadequately understood. Also, there is a demand for strategies to increase the absorption of light, reduce trap states, and modify the energy levels of perovskite QDs.

In this study, …


Thermal Alteration Of The Mineralogy Of Calcium Sulfoaluminate Cements: Implications For The Performance Of Rapid Repair Materials, Jillian Cavellier Jan 2024

Thermal Alteration Of The Mineralogy Of Calcium Sulfoaluminate Cements: Implications For The Performance Of Rapid Repair Materials, Jillian Cavellier

Theses and Dissertations--Earth and Environmental Sciences

Calcium sulfoaluminate (CSA) was developed in part to lessen the environmental impact of cementitious materials compared to traditional Portland cements. CSA was first put into production in the 1970s and has been undergoing various performance testing to investigate its durability. Yet to be evaluated is CSA’s response to a rapid, high temperature event. In this study, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectrometry and scanning electron microscope imaging were used to analyze alterations in the mineralogy due to such an event. As found in previous studies, after ~125°C, ettringite has been completely dehydrated. Ettringite decomposes into bassanite and calcium …


Visualizing And Automating Past, Real-Time, And Forecast Dynamic Hazard Maps For Shallow Colluvial Landslides In Eastern Kentucky, Nathaniel O'Leary Jan 2024

Visualizing And Automating Past, Real-Time, And Forecast Dynamic Hazard Maps For Shallow Colluvial Landslides In Eastern Kentucky, Nathaniel O'Leary

Theses and Dissertations--Earth and Environmental Sciences

Landslide hazards are a persistent threat to communities and infrastructure in Eastern Kentucky, where steep slopes, shallow colluvial soils, and variable hydrological conditions make slope failures frequent. This thesis presents an integrated approach to landslide hazard mapping (LHM) through the development of dynamic, spatiotemporal LHMs for shallow colluvial landslides. Two studies within this work investigate and refine the use of the Lu and Godt (2008) factor of safety (FS) equation to improve landslide predictions. The first study establishes a novel LHM workflow using Hydrus-1D to simulate soil moisture infiltration and fluctuations from precipitation and evapotranspiration (ET) data. This study also …


Advancements In Elliptic Mesh Redistribution And Automated Overset Grid Generation For Computational Fluid Dynamics, Chase Ashby Jan 2024

Advancements In Elliptic Mesh Redistribution And Automated Overset Grid Generation For Computational Fluid Dynamics, Chase Ashby

Theses and Dissertations--Mathematics

Automated and robust structured curvilinear overset grid generation remains a significant challenge for the application of computational fluid dynamics. This thesis intro- duces a specialized anisotropic Mach cone aligned adaptation algorithm for low-boom simulations and an automated procedure for generating structured curvilinear overset grids for immersed boundary simulations. Results demonstrate that anisotropic mesh adaptation can reduce computational resource usage by over 50% while maintaining sonic boom prediction accuracy across the entire sonic boom domain compared to user-constructed Mach cone aligned grids. The proposed immersed overset grid gen- eration procedure eliminates the need for complex surface generation algorithms, producing grids suitable …