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Articles 34771 - 34800 of 196445

Full-Text Articles in Engineering

Developing Positive Thermal Coefficient (Ptc) Heaters For Solar Electric Cooking, Katarina Ivana Brekalo, Andrew Shepherd Sep 2022

Developing Positive Thermal Coefficient (Ptc) Heaters For Solar Electric Cooking, Katarina Ivana Brekalo, Andrew Shepherd

Physics

Positive Thermal Coefficients, PTCs, are materials that abruptly change in resistance in response to changes in temperature. The purpose of this experiment is to explore the viability of using the switching type ceramic PTC thermistor as a replacement for current resistive heaters. These types of PTCs have a nonlinear change in resistance with increases in temperature. This device will be used as a temperature-controlling heating element intended to power an Insulated Solar Electric Cooker (ISEC). The ISEC is designed to cook meals throughout the day for impacted communities as an alternative cooking method that doesn’t require biofuel as an energy …

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Tunable Filtration Of Particles During Dip-Coating, Connor Copeland Sep 2022

Tunable Filtration Of Particles During Dip-Coating, Connor Copeland

All Theses

When a solid substrate is withdrawn from a liquid bath a thin coating is deposited whose thickness is given by the Landau-Levich-Derjaguin (LLD) law. We perform an experimental study of dip coating of particle suspensions showing that particles of a given size can become entrained in the meniscus by the competition between viscous and surface tension forces. This is called capillary filtration and can be used as a tunable dynamic filter. For single particle suspensions, filtration can be in terms of either clumps or single particles, with the relevant entrainment points depending upon the rheology of the working fluid, either …

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How Will Heat Pumps Affect Electricity Load Profiles For Buildings In Ireland? Empirical Data Used To Model Possible Financial Impacts Facing Consumers, Michael Mcdonald Sep 2022

How Will Heat Pumps Affect Electricity Load Profiles For Buildings In Ireland? Empirical Data Used To Model Possible Financial Impacts Facing Consumers, Michael Mcdonald

Conference papers

The current geopolitical situation is certainly challenging the colossal transition to Zero carbon Economy. In fact, in the coming years, the electricity sector will have to find new innovative ways to meet the ever increasing need for energy without the over reliance on fossil fuels and their country of origin. Over the next decade, oil and gas boilers will not be permitted in new buildings in Ireland, in line with the Irish Building Regulations, Technical Guidance Document L – Conservation of Fuel and Energy 2021. This is a major shift in traditional building services methodology and heat technology. …

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Developing Scaling Laws To Predict Compressive Mechanical Properties And Determine Geometrical Parameters Of Modified Bcc Lattice Structures, Hasanain Abdulhadi, Abdalsalam Fadeel, Tahseen A. Alwattar, Ahsan Mian Sep 2022

Developing Scaling Laws To Predict Compressive Mechanical Properties And Determine Geometrical Parameters Of Modified Bcc Lattice Structures, Hasanain Abdulhadi, Abdalsalam Fadeel, Tahseen A. Alwattar, Ahsan Mian

Mechanical and Materials Engineering Faculty Publications

The objective of this study is to develop generalized empirical closed-form equations to predict the compressive mechanical properties and determine geometrical parameters. To achieve that, 117 models are built and analyzed using ABAQUS/CAE 2016 to provide two types of reliable data: one for lattice mechanical properties based on finite element method and the other for geometrical parameters using the measurements of ABAQUS diagnostic tool. All the models are created by modifying the basic feature of body-centered cubic lattice structure based on a range of strut angles, a set of relative densities, and two design sets. Also, the influence of lattice …

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Studying Routing Issues In Vanets Using Ns-3 And Sumo, Mohammad Mahmoud Abdellatif, Omar E. Aly Sep 2022

Studying Routing Issues In Vanets Using Ns-3 And Sumo, Mohammad Mahmoud Abdellatif, Omar E. Aly

Electrical Engineering

ehicular Ad-hoc Networks VANETs are normally sparse, highly dense, and highly mobile with many different and ever-changing topologies. These characteristics impose a challenge on finding a routing algorithm that fits the requirements of such network. The aim of this work is to study the performance issues of VANETs under different scenarios using realistic mobility models. In this paper, a comparative study is done among Ad-hoc On- Demand Distance Vector (AODV), Optimized Link State Routing (OLSR) and position-based routing protocols, namely Greedy Perimeter stateless routing (GPSR), and Max duration Min angle GPSR (MMGPSR). The comparison is done using key quality of …

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A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas, Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li Sep 2022

A Database Of Teleseismic Shear-Wave Splitting Measurements For The Ordos Block And Adjacent Areas, Lin Liu, Stephen S. Gao, Kelly H. Liu, Tu Xue, Yan Jia, Sanzhong Li

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Ordos block of the north China craton and its surrounding regions are affected by the India-Eurasia collision to the southwest and the subduction of the Pacific beneath the Eurasian plates to the east. To provide the foundation for delineating lithospheric deformation and asthenospheric flow beneath this tectonically diverse region, we have created a database of individual shear-wave splitting (SWS) parameters by applying a uniform set of data processing procedures. After automatic data processing and manual checking, a total of 16,228 pairs of well-defined PKS, SKKS, and SKS splitting parameters (fast orientations and splitting times) are obtained from 1023 broadband …

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Crustal Structure And Subsidence Mechanisms Of The Williston Basin: New Constraints From Receiver Function Imaging, Jianguo Song, Stephen S. Gao, Kelly H. Liu, Muchen Sun, Youqiang Yu, Fansheng Kong, Kevin Mickus Sep 2022

Crustal Structure And Subsidence Mechanisms Of The Williston Basin: New Constraints From Receiver Function Imaging, Jianguo Song, Stephen S. Gao, Kelly H. Liu, Muchen Sun, Youqiang Yu, Fansheng Kong, Kevin Mickus

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Mechanisms responsible for the long-term subsidence of intracontinental basins such as the Williston Basin in North America remain enigmatic, partly due to the thick sedimentary layer commonly found in the basins that prevents reliably imaging the deep crustal and upper mantle structures using some of the most-commonly employed seismic methods such as receiver function analysis. In this study, we used receiver functions recorded by 274 USArray and other stations in the Williston Basin and adjacent areas to investigate the layered structure of the crust in the hydrocarbon-rich intracontinental basin. After the removal of strong reverberations on the receiver functions associated …

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Investigation On Chloride Binding Capacity And Stability Of Friedel's Salt In Graphene Oxide Reinforced Cement Paste, Wu Jian Long, Xuanhan Zhang, Gan Lin Feng, Jing Xie, Feng Xing, Biqin Dong, Jinrui Zhang, Kamal Khayat Sep 2022

Investigation On Chloride Binding Capacity And Stability Of Friedel's Salt In Graphene Oxide Reinforced Cement Paste, Wu Jian Long, Xuanhan Zhang, Gan Lin Feng, Jing Xie, Feng Xing, Biqin Dong, Jinrui Zhang, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Chloride binding capacity is one of the important factors affecting chloride induced rebar corrosion in reinforced concrete structures. Moreover, the stability of Friedel's salt will also affect the chloride binding capacity of cement-based materials. This study investigates the effect of graphene oxide (GO) on the chloride binding capacity of cement paste and stability of Friedel's salt under different pH conditions. Experiments of X-ray diffraction (XRD), Thermogravimetric analyzer (TGA), Scanning electron microscope (SEM) and Energy dispersive spectroscopy (EDS) were performed to analyze the phase assemblage, micro morphology, element ratio and the enhanced mechanisms. Results showed that the 0.2 wt% GO addition …

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Investigation Of Illegal Weigh Station Bypassing, Mallory Brown, Andrew Martin, David Leddy, Jennifer Walton Sep 2022

Investigation Of Illegal Weigh Station Bypassing, Mallory Brown, Andrew Martin, David Leddy, Jennifer Walton

Kentucky Transportation Center Research Report

This study recommends best practices to curb illegal weigh station bypassing by commercial motor vehicles (CMVs). Analysis of historical data collected by Kentucky State Police – Commercial Vehicle Enforcement (KSP-CVE) for 2017-2021 revealed that CMV drivers were charged with illegally bypassing weigh stations 2,616 times. Drivers were charged with an average of two other violations when cited for illegal bypassing — most often violations related to credentialing, vehicle safety, or driver safety. Site visits to three permanent weigh stations in Kentucky revealed that CMVs regularly bypass weigh stations illegally, including those authorized to use preclearance systems (Drivewyze and PrePass). A …

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Renewable And Recyclable Polymeric Materials For Food Packaging: A New Open Special Issue In Materials, Shima Jafarzadeh, Masoumeh Zargar, Mehrdad Forough Sep 2022

Renewable And Recyclable Polymeric Materials For Food Packaging: A New Open Special Issue In Materials, Shima Jafarzadeh, Masoumeh Zargar, Mehrdad Forough

Research outputs 2022 to 2026

“Renewable and Recyclable Polymeric Materials for Food Packaging” is a new open Special Issue of Materials that will publish original and review papers on new scientific and applied research, and the articles it contains will make a contribution to the discovery and understanding of biodegradable and recyclable materials, their functional properties, characterization and applications.

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A Heuristic Approach To Predict The Tensile Strength Of A Non-Persistent Jointed Brazilian Disc Under Diametral Loading, Mostafa Asadizadeh, Nima Babanouri, Taghi Sherizadeh Sep 2022

A Heuristic Approach To Predict The Tensile Strength Of A Non-Persistent Jointed Brazilian Disc Under Diametral Loading, Mostafa Asadizadeh, Nima Babanouri, Taghi Sherizadeh

Mining Engineering Faculty Research & Creative Works

The mechanical response of rock bridges plays a key role in the stability of concrete and rock structures. In particular, the tensile failure of non-persistent discontinuities can result in their coalescence and the failure of rock or concrete engineering structures. The effect of non-persistent joint parameters on rock structures' failure under tensile mode has not been investigated by many researchers yet. Many non-persistent jointed Brazilian concrete discs are tested under diametral loading in this work, to study the influence of joint spacing, joint continuity factor, loading direction with regard to joint angle, and bridge angle on their tensile behavior. Heuristic …

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Wettability Alteration Process At Pore-Scale During Engineered Waterflooding Using Computational Fluid Dynamics, Yongqiang Chen, Ping Chang, Guang Xu, Quan Xie Sep 2022

Wettability Alteration Process At Pore-Scale During Engineered Waterflooding Using Computational Fluid Dynamics, Yongqiang Chen, Ping Chang, Guang Xu, Quan Xie

Mining Engineering Faculty Research & Creative Works

Engineered waterflooding modifies chemistry of injected brine to efficiently and environmentally friendly enhance oil recovery. The common practice of engineered waterflooding includes low salinity waterflooding (LSW) and carbonated waterflooding. Among these oil recovery methods, wettability alteration has been perceived as a critical physicochemical process for additional oil recovery. While extensive work has been conducted to characterize the wettability alteration, the existing theory cannot explain the conflict oil recovery between secondary mode (injecting engineered water at the very beginning of flooding) and tertiary mode (injecting engineered water after conventional waterflooding), where secondary engineered waterflooding always gives a greater incremental oil recovery …

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Products Pricing And Return Strategies For The Dual Channel Retailers, Jian Liu, Xinyue Sun, Yanyan Liu Sep 2022

Products Pricing And Return Strategies For The Dual Channel Retailers, Jian Liu, Xinyue Sun, Yanyan Liu

Electrical and Computer Engineering Faculty Research & Creative Works

This paper analyzed how different return strategies and return rates affect dual-channel retailers' profits and channel pricings. Return can stimulate sales; however, the return has presented significant challenges to retailers. The return has long been studied to maximize profit and pricing; however, the different return strategies for dual-channel retailers affect channel both. This paper aimed to study whether or not dual-channel retailers should allow customers to return items in two channels and whether or not the retailer should contract with the manufacturers and pay extra fees to return products. This study indicated when the retailer should allow customers' returns to …

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Effects Of Drying Temperature On Preparation Of Pectin Polysaccharide Thin Film For Resistive Switching Memory, Poh Liang Yap, Kuan Yew Cheong, Hooi Ling Lee, Feng Zhao Sep 2022

Effects Of Drying Temperature On Preparation Of Pectin Polysaccharide Thin Film For Resistive Switching Memory, Poh Liang Yap, Kuan Yew Cheong, Hooi Ling Lee, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

Commercially purchased pectin powder was formulated and processed into a thin film with different drying temperatures (60 °C–180 °C) and subsequently, sandwiched between Ag and ITO as top and bottom electrodes, respectively, for resistive switching memory study. Chemical functional groups, surface roughness, elemental chemical composition, and cross-sectional morphology of the dried pectin thin film were investigated via Fourier transform infrared spectroscopy, atomic force microscopy, and high-resolution transmission electron microscopy-energy dispersive X-ray spectroscopy. The higher the drying temperature, the rougher the surface with less residual moisture and more defect sites within the thin film was observed. Current–voltage measurements together with the …

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Estimating Flashpoints Of Fuels And Chemical Compounds Using Hybrid Machine-Learning Techniques, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi, Abdoulmohammad Gholamzadeh Chofreh, Feybi Ariani Goni, Jiří Jaromír Klemeš Sep 2022

Estimating Flashpoints Of Fuels And Chemical Compounds Using Hybrid Machine-Learning Techniques, Farid Amirkhani, Amir Dashti, Hossein Abedsoltan, Amir H. Mohammadi, Abdoulmohammad Gholamzadeh Chofreh, Feybi Ariani Goni, Jiří Jaromír Klemeš

Chemical and Biochemical Engineering Faculty Research & Creative Works

Flashpoint of organic materials is a crucial physical property in industrial applications and laboratory experiments, which provides information on safety standards and needed precautions in handling various organic materials. Proposed methods to determine the flashpoint of an organic material suffer from dependency on other physical properties of the chemical or demand complicated calculations which are time-consuming. In this work, a direct system model is proposed to anticipate the flashpoints of organic materials for a wide range of chemical compounds. The following models of genetic algorithm-adaptive neuro-fuzzy inference system, the least-squares version of the support vector machine, particle swarm optimization-adaptive neuro-fuzzy …

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Metallization Of Polymers And Composites: State-Of-The-Art Approaches, Ruslan Melentiev, Arief Yudhanto, Ran Tao, Todor Vuchkov, Gilles Lubineau Sep 2022

Metallization Of Polymers And Composites: State-Of-The-Art Approaches, Ruslan Melentiev, Arief Yudhanto, Ran Tao, Todor Vuchkov, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Polymers and their composites are widely used for designing structures in aerospace, automotive, electronic, sport industries due to their lightweight, cost, and processing advantages. However, the surface of polymeric materials typically exhibits intrinsic deficiencies, limiting their durability and functionalities, e.g., low wear resistance, low thermal and electrical conductivity, low adhesion, low bioactivity, low reflectiveness, and weak photochemical resistance. Polymer metallization is an emerging concept that addresses these deficiencies by forming a metallic skin on polymeric surfaces. Herein, the working principles, recent advances, challenges, functional capabilities, and applications of the state-of-the-art polymer metallization methods in the fields of additive manufacturing, coating …

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Improved Additive Manufacturing Of Silicon Carbide Parts Via Pressureless Electric Field-Assisted Sintering, Adam Bratten, Ruoyu Chen, Joshua Rittenhouse, Ming-Chuan Leu, Haiming Wen Sep 2022

Improved Additive Manufacturing Of Silicon Carbide Parts Via Pressureless Electric Field-Assisted Sintering, Adam Bratten, Ruoyu Chen, Joshua Rittenhouse, Ming-Chuan Leu, Haiming Wen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

High solids loading silicon carbide (SiC)-based aqueous slurries containing only.5 wt. % organic additives were utilized to create specimens of various geometries via an extrusion-based additive manufacturing (AM) technique. Pressure less electric field-assisted sintering was performed to densify each specimen without deformation. The combination of these techniques produced parts with >98% relative density despite containing only 5 wt.% oxide sintering additives. After sintering, specimens contained only the α-SiC and yttrium aluminum perovskite phases. This suggests the evolution of a nonequilibrium yttrium aluminate phase, as well as transformation from β-SiC to α-SiC. The fabrication method presented in this work has advantages …

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Removing Soluble Phosphorus From Tertiary Municipal Wastewater Using Phosphorus- Deprived, Filamentous Microalgae, Aloysia Ahern Sep 2022

Removing Soluble Phosphorus From Tertiary Municipal Wastewater Using Phosphorus- Deprived, Filamentous Microalgae, Aloysia Ahern

Master's Theses

Harmful algal blooms (HABs) can be detrimental to ecosystems, human health, and economies. The low levels of phosphorus remaining in the effluent of municipal wastewater treatment plants can contribute to HAB formation. To achieve more complete phosphorus removal, an effluent treatment method has been proposed that uses phosphorus-deprived, filamentous microalgae to quickly assimilate soluble phosphorus to low concentrations. This study investigated two parameters that influence the feasibility of such a system: (1) the biomass growth productivity of algal cultures during the phosphorus deprivation period and (2) the correlation between the duration of this period and the phosphorus uptake rate by …

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2022 Safety Belt Usage Survey In Kentucky, Erin Lammers-Staats, Derek S. Young, Eric Green, Kenneth R. Agent Sep 2022

2022 Safety Belt Usage Survey In Kentucky, Erin Lammers-Staats, Derek S. Young, Eric Green, Kenneth R. Agent

Kentucky Transportation Center Research Report

Each year Kentucky Transportation Center researchers conduct a safety belt usage survey to estimate Kentucky’s statewide safety belt usage rate. In 2022, the safety belt usage rate in Kentucky was 86.72 percent, which represents a 3.06 decline over 2021. Safety belt usage peaked in 2018 at 89.99 percent. Declines in safety belt usage rate over the past couple years may be attributable in part to changes in driver behaviors and traffic dynamics following the COVID-19 pandemic. If Kentucky wants to increase safety belt usage rates, the state may need ramp up enforcement of safety belt laws or bolster educational outreach …

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Development Of Method To Characterize Adhesion Of Electrically Conductive Adhesive For Flexible Electronics, Joshua Corbin Sep 2022

Development Of Method To Characterize Adhesion Of Electrically Conductive Adhesive For Flexible Electronics, Joshua Corbin

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

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Turning Of Carbon Fiber Reinforced Polymer (Cfrp) Composites: Process Modeling And Optimization Using Taguchi Analysis And Multi-Objective Genetic Algorithm, S. M. Abdur Rob, Anil K. Srivastava Sep 2022

Turning Of Carbon Fiber Reinforced Polymer (Cfrp) Composites: Process Modeling And Optimization Using Taguchi Analysis And Multi-Objective Genetic Algorithm, S. M. Abdur Rob, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications

Carbon Fiber Reinforced Polymer (CFRP) composites have been widely used in aerospace, automotive, nuclear, and biomedical industries due to their high strength-to-weight ratio, corrosion resistance, durability, and excellent thermo-mechanical properties in non-oxidative atmospheres. Machining of CFRP composites has always been a challenge for manufacturers. In this research, a comparative study was performed between the optimal machining parameters of coated and uncoated carbide inserts obtained from the Multi-Objective Genetic Algorithm during turning of CFRP composites. It was found that coated carbide inserts provide lower tool wear and surface roughness, but higher cutting forces compared to those of uncoated carbide inserts …

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Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda Sep 2022

Automated Posture Positioning For High Precision 3d Scanning Of A Freeform Design Using Bayesian Optimization, Zhaohui Geng, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications

Three-dimensional scanning is widely used for the dimension measurements of physical objects with freeform designs. The output point cloud is flexible enough to provide a detailed geometric description for these objects. However, geometric accuracy and precision are still debatable for this scanning process. Uncertainties are ubiquitous in geometric measurement due to many physical factors. One potential factor is the object’s posture in the scanning region. The posture of target positioning on the scanning platform could influence the normal of the scanning points, which could further affect the measurement variances. This paper first investigates the geometric and spatial factors that could …

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Minimax Registration For Point Cloud Alignment, Zhaohui Geng, Mauro Garcia, Bopaya Bidanda Sep 2022

Minimax Registration For Point Cloud Alignment, Zhaohui Geng, Mauro Garcia, Bopaya Bidanda

Manufacturing & Industrial Engineering Faculty Publications

The alignment, or rigid registration, of three-dimensional (3D) point clouds plays an important role in many applications, such as robotics and computer vision. Recently, with the improvement in high precision and automated 3D scanners, the registration algorithm has become critical in a manufacturing setting for tolerance analysis, quality inspection, or reverse engineering purposes. Most of the currently developed registration algorithms focus on aligning the point clouds by minimizing the average squared deviations. However, in manufacturing practices, especially those involving the assembly of multiple parts, an envelope principle is widely used, which is based on minimax criteria. Our present work …

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Finite Fatigue Life Prediction Of Additively Manufactured Aircraft Engine Turbine Blade With Respect To Internal Defect Size And Location, Daniel G. Miller Sep 2022

Finite Fatigue Life Prediction Of Additively Manufactured Aircraft Engine Turbine Blade With Respect To Internal Defect Size And Location, Daniel G. Miller

Theses and Dissertations

Current fatigue life modeling techniques with respect to defects emphasize the dependence on the defect size with respect to fatigue life, but does not account for the effects of where a defect might be located. This research outlines a process to include defect location into the model analysis for a more precise prediction of the number of cycles to failure and where the finial failure could occur within a component. The focus is on a turbine blade structure using IN718 subjected to a pure vibratory load. The basic model predicts component life using a stress map from the frequency analysis …

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Mechanical Properties And Tension-Tension Fatigue Behavior Of A Novel Additively Manufactured Polymer Matrix Composite At Room And Elevated Temperature, Grayson M. Harber Sep 2022

Mechanical Properties And Tension-Tension Fatigue Behavior Of A Novel Additively Manufactured Polymer Matrix Composite At Room And Elevated Temperature, Grayson M. Harber

Theses and Dissertations

The tension-tension fatigue behavior of a novel additively manufactured AM carbon fiber reinforced polymer matrix composite was studied. This novel material system consists of T1100 carbon fibers, and a UV photocured resin developed by Continuous Composites and Sartomer. Tensile properties and tension-tension fatigue were investigated for the 090 fiber orientation as well as for the ±45 fiber orientation. Specimens with 0/90 fiber orientation were tested at ambient laboratory temperature 23 °C and at elevated temperature 150 °C, while the specimens with the ±45 fiber orientation were tested only at ambient laboratory temperature. Tension-tension fatigue testing was carried out with a …

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Retention Prediction And Policy Optimization For United States Air Force Personnel Management, Joseph C. Hoecherl Sep 2022

Retention Prediction And Policy Optimization For United States Air Force Personnel Management, Joseph C. Hoecherl

Theses and Dissertations

Effective personnel management policies in the United States Air Force (USAF) require methods to predict the number of personnel who will remain in the USAF as well as to replenish personnel with different skillsets over time as they depart. To improve retention predictions, we develop and test traditional random forest models and feedforward neural networks as well as partially autoregressive forms of both, outperforming the benchmark on a test dataset by 62.8% and 34.8% for the neural network and the partially autoregressive neural network, respectively. We formulate the workforce replenishment problem as a Markov decision process for active duty enlisted …

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High Power Microwave Operational Exposure Detection Using Thermoacoustic Wave Generation In Lossy Dielectric Polymers, James J. Frey Sep 2022

High Power Microwave Operational Exposure Detection Using Thermoacoustic Wave Generation In Lossy Dielectric Polymers, James J. Frey

Theses and Dissertations

A feasibility analysis for the use of microwave-induced thermoacoustic (TA) wave generation in lossy dielectric media to detect pulsed high power microwave directed energy weapons in force health protection applications was conducted based on a series of empirical and computational investigations. A potential target volume material, carbon-loaded polytetrafluoroethylene, was identified for further study based on anticipated complex dielectric properties, with laboratory measurements of select electromagnetic (EM), thermal, and elastic material properties of relevance to the TA effect conducted to determine parameter values. A planar geometry TA-based signal chain model using thin film piezoelectric sensors was developed for both finite element …

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Value Focused Thinking Analysis Of C-Band Australia Radar Operations, Samuel Ray Grothman Sep 2022

Value Focused Thinking Analysis Of C-Band Australia Radar Operations, Samuel Ray Grothman

Theses and Dissertations

The radars used for Space Domain Awareness (SDA) are inherently all-weather, day/night sensors capable of around the clock operations. Despite this fact, some radars are operated for fewer than their maximum operating capabilities. The decision-making process for selecting the operating hours of a sensor has historically been based on only a few factors or just one. This research uses the techniques in Value Focused Thinking to develop an evaluation process to score possible alternatives and find the alternative with the most value for the decision maker. By investigating the value that is added by operating an SDA radar, it is …

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Enabling Rapid Chemical Analysis Of Plutonium Alloys Via Machine Learning-Enhanced Atomic Spectroscopy Techniques, Ashwin P. Rao Sep 2022

Enabling Rapid Chemical Analysis Of Plutonium Alloys Via Machine Learning-Enhanced Atomic Spectroscopy Techniques, Ashwin P. Rao

Theses and Dissertations

Analytical atomic spectroscopy methods have the potential to provide solutions for rapid, high fidelity chemical analysis of plutonium alloys. Implementing these methods with advanced analytical techniques can help reduce the chemical analysis time needed for plutonium pit production, directly enabling the 80 pit-per-year by 2030 manufacturing goal outlined in the 2018 Nuclear Posture Review. Two commercial, handheld elemental analyzers were validated for potential in situ analysis of Pu. A handheld XRF device was able to detect gallium in a Pu surrogate matrix with a detection limit of 0.002 wt% and a mean error of 8%. A handheld LIBS device was …

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Analyzing Microarchitectural Residue In Various Privilege Strata To Identify Computing Tasks, Tor J. Langehaug Sep 2022

Analyzing Microarchitectural Residue In Various Privilege Strata To Identify Computing Tasks, Tor J. Langehaug

Theses and Dissertations

Modern multi-tasking computer systems run numerous applications simultaneously. These applications must share hardware resources including the Central Processing Unit (CPU) and memory while maximizing each application’s performance. Tasks executing in this shared environment leave residue which should not reveal information. This dissertation applies machine learning and statistical analysis to evaluate task residue as footprints which can be correlated to identify tasks. The concept of privilege strata, drawn from an analogy with physical geology, organizes the investigation into the User, Operating System, and Hardware privilege strata. In the User Stratum, an adversary perspective is taken to build an interrogator program that …

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