Digital Commons Network^™

An Investigation Of Unsteady Thermal Exchange Processes In Geothermal Heat Exchangers, Ganesh Ravi Shanker

Doctoral Dissertations

“Geothermal heat exchangers, has become one of the highly recognized non conventional heat exchangers as they utilize renewable energy source earth to initiate the thermal energy transfer. However, these heat exchangers suffer from a expensive installation cost due to their conservative design model, thereby facilitating the need to identify and improve the design. In this dissertation, three gaps, which identifies improvement over conservative design were investigated, to assess the heat exchanger performance. In the first approach, borehole thermal and geometrical properties were investigated keeping the outlet leg of the heat exchanger as adiabatic, which neglects the thermal short-circuiting between the …

Modeling For Off-Chip High-Speed Designs, Siqi Bai

Doctoral Dissertations

”Signal integrity (SI) and power integrity (PI) are essential for datacenter application. A typical datacenter rack consists of a switch on the top of the rack, servers, and storage units. Three SI/PI related problems for datacenter application are analyzed in this research.

The first topic is analysis on power via induced Quasi-quarter-wavelength resonance to reduce crosstalk. Using an analytical model and 3D full-wave simulation models, a physical explanation for the unexpected resonance in the differential signal pairs is proposed. Considering the difficulty in changing the pin map of the IC-package, several PCB layouts to eliminate the power via induced quasi-quarter-wavelength …

Advanced Control Techniques For Modern Inertia Based Inverters, Sepehr Saadatman

Doctoral Dissertations

”In this research three artificial intelligent (AI)-based techniques are proposed to regulate the voltage and frequency of a grid-connected inverter. The increase in the penetration of renewable energy sources (RESs) into the power grid has led to the increase in the penetration of fast-responding inertia-less power converters. The increase in the penetration of these power electronics converters changes the nature of the conventional grid, in which the existing kinetic inertia in the rotating parts of the enormous generators plays a vital role. The concept of virtual inertia control scheme is proposed to make the behavior of grid connected inverters more …

Porous Polymer Compositions For The Synthesis Of Monolithic Bimodal Microporous/Macroporous Carbon Compositions Useful For Selective Co2 Sequestration, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed

Patents

The present invention discloses novel porous polymeric compositions comprising random copolymers of amides, imides, ureas, and carbamic-anhydrides, useful for the synthesis of monolithic bimodal microporous/macroporous carbon aerogels. It also discloses methods for producing said microporous/macroporous carbon aerogels by the reaction of a polyisocyanate compound and a polycarboxylic acid compound, followed by pyrolytic carbonization, and by reactive etching with CO2 at elevated temperatures. Also disclosed are methods for using the microporous/macroporous carbon aerogels in the selective capture and sequestration of carbon dioxide.

Open Data From The First And Second Observing Runs Of Advanced Ligo And Advanced Virgo, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software.

Lanchester's Equations And Cyberwarfare, George Markowsky, Linda Markowsky

Computer Science Faculty Research & Creative Works

In his classic book Aircraft in Warfare, F. W. Lanchester discussed different types of warfare and presented equations, called the Lanchester equations, that can be used to model the results of battles between two forces of different sizes or capabilities. This paper introduces the Lanchester equations and provides a theoretical discussion leading to an analysis of the relative value of increasing the effectiveness of military assets vs. increasing the quantity of those assets. In particular, we show that increasing the effectiveness contributes only linearly to the power of a combatant, but increasing the quantity contributes quadratically. This paper also presents …

Multimodal Neuroscience Data Modeling And Inference, Sima Azizi

Doctoral Dissertations

“Mathematical models can be combined with deep learning and machine learning methods to provide new insights in neuroscience. The field of neuroscience is characterized by rich datasets that include fluid biomarkers, EEG signals, and advanced neuroimages. Recent advances in natural language processing have led to the opportunity to gain additional insights from rapidly growing text databases as well as electronic health records. In this research, we focus on applying computational intelligence methods to the analysis of three different complex data sources: blood levels of disease biomarkers, EEG signals from schizophrenic patients, and disease phenotypes encoded in electronic health records. First, …

Enthesis Strength, Toughness And Stiffness: An Image-Based Model Comparing Tendon Insertions With Varying Bony Attachment Geometries, Mikhail Golman, Victor Birman, Stavros Thomopoulos, Guy M. Genin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Tendons of the body differ dramatically in their function, mechanics and range of motion, but all connect to bone via an enthesis. Effective force transfer at the enthesis enables joint stability and mobility, with strength and stiffness arising from a fibrous architecture. However, how enthesis toughness arises across tendons with diverse loading orientations remains unclear. To study this, we performed simultaneous imaging of the bone and tendon in entheses that represent the range of tendon-to-bone insertions and extended a mathematical model to account for variations in insertion and bone geometry. We tested the hypothesis that toughness, across a range of …

Modeling Rack Force For Steering Maneuvers In A Stationary Vehicle, Nilay Kant, Raunav Chitkara, Prerit Pramod

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A steering system converts circular motion of the steering wheel into yaw motion of the road-wheels. In absence of a steering assist mechanism, the driver torque overcomes the tire-road friction forces, which is transmitted to the steering rack through tie rods attached to the road-wheels. The net force acting on the rack is then transmitted to the steering wheel through mechanical linkages which results in natural haptic feedback, commonly referred to as the steering feel. In an electric/hydraulic power steering, an electro-mechanical actuator applies assist force, which reduces the torque required by the driver. In order to maintain stability of …

Novel Adaptive Sampling Algorithm For Pod-Based Non-Intrusive Reduced Order Model, Jiachen Wang, Xiaosong Du, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The proper orthogonal decomposition (POD) based reduced-order model (ROM) has been an effective tool for flow field prediction in the engineering industry. The sample selection in the design space for POD basis construction affects the ROM performance sensitively. Adaptive sampling can significantly reduce the number of samples to achieve the required model accuracy. In this work, we propose a novel adaptive sampling algorithm, called conjunction sampling strategy, which is based on proven strategies. The conjunction sampling strategy is demonstrated on airfoil flow field prediction within the transonic regime. We demonstrate the performance of the proposed strategy by running 10 trials …

Design And Development Of A Variable Resistance Hand Exerciser Using A Compliant Mechanism, Jyothi Komatireddy

Masters Theses

"Rehabilitation exercise plays a vital role in recovering from an injury or illness condition by improving flexibility and restoring muscle strength. If not done correctly, exercising can cause more damage to the health condition than in healing. Understanding the muscle’s resistance level while performing an exercise helps design the exercising equipment not to overstrain the muscle during operation. This research presents a methodology to develop a variable-resistance hand exerciser by using a compliant cam-follower mechanism. The proposed design comprised a compliant follower and a rigid cam. The rigid cam is synthesized using the human hand force-deflection profile as an input …

Relationships Among Mineralogy, Geochemistry, And Oil And Gas Production In The Tuscaloosa Marine Shale, Hayley Roxana Beitel

Masters Theses

"The Tuscaloosa Marine Shale (TMS) is an unconventional shale reservoir located in southeast Louisiana and southwest Mississippi. Limited mineralogical and geochemical data for the TMS have been published. The data that do exist indicate that the formation is heterogeneous. Consequently, previous investigators and oil and gas companies have not managed to effectively link mineralogical and chemical changes to oil and gas production in the TMS. These linkages are critical to establish for future exploration efforts. In this study, we attempt to establish these relationships by gathering all existing mineralogical and chemical data in the TMS, including newly acquired data from …

Predator Scent And Presence Alter Mammal Assemblages In The Missouri Ozarks, Usa, Cara Jean Yocom-Russell

Masters Theses

"Species that are vulnerable to predation exhibit a host of behavioral and physiological adaptations toward the avoidance of this outcome: Heightened awareness of surroundings through visual, olfactory, and auditory senses are common ways in which these species avoid detection by predators. While links between direct predator-prey relationships are well established, less is known about how predators can shape overall community structure or the populations of secondary or less frequently consumed prey items. As humans expand into rural areas, the frequency of wildlife conflicts rises. In response, humans look to prevent these events with a variety of methods. One such method …

A Simple Background Elimination Method For Miniaturized Fiber-Optic Raman Probe, Bohong Zhang

Masters Theses

"Raman scattering is called a photonic - molecular interaction based on the kinetic model of the analytic. Due to the uniqueness of the Raman scattering technique, it can provide a unique fingerprint signal for molecular recognition. However, a serious challenge often encountered in Raman measurement comes from the requirements of fast, real-time remote sensing, background fluorescence suppression, and micro-environmental detection.

A new Miniaturized Fiber-Optic Raman Probe (MFORP) for Raman spectroscopy, used especially for eliminating background fluorescence and enhancing sampling, is presented. Its main purpose is to provide an overview of excellent research on the detection of very small substances and …

Multiple Generations Of Phlogopite In An Alnöite Diatreme: Insights Into The Petrogenesis Of The Avon Alkaline Igneous Province, Missouri, Nathan Gregory Limbaugh

Masters Theses

“Alkaline Ultramafic Carbonatite (AUC) complexes, although rare, are valued for diamonds and REEs, and as windows into subcontinental and mantle processes as recorded by rock fabrics, mineral spatial relationships, and mineral compositions. We report specifically on olivine and phlogopite petrographic relationships and compositions from the Devonian alnoite diatreme-facies of the Avon Alkaline Igneous Province, Missouri. The diatreme alnoite is a mixture of domains of olivine magmaclasts (OM) set in a crystal-rich melilite matrix. OM are highly fractured, serpentinized olivine pseudomorphs with variable amounts of pristine olivine fragments. Larger olivine domains typically exhibit clear crystal faces and irregular “channels” indicative of …

Early Wildfire Detection By Air Quality Sensors On Unmanned Aerial Vehicles: Optimization And Feasibility, Doaa Rjoub

Masters Theses

“Millions of acres of forests are destroyed by wildfires every year, causing ecological, environmental, and economical losses. The recent wildfires in Australia and the Western U.S. smothered multiple states with more than fifty million acres charred by the blazes. The warmer and drier climate makes scientists expect increases in the severity and frequency of wildfires and the associated risks in the future. These inescapable crises highlight the urgent need for early detection and prevention of wildfires. This work proposed an energy management framework that integrated unmanned aerial vehicle (UAV) with air quality sensors for early wildfire detection and forest monitoring. …

Bond Graph Modeling Of Critical Infrastructures For Cyber-Physical Security Implementation, Michele Jane White

Masters Theses

“In developed societies, there exists infrastructure vital to everyday life. This includes water and power systems. Technology is quickly evolving and being implemented on these utilities. This technology can range from smart metering in neighborhoods to volume sensors in local waste water treatment facilities. When networking, sensing, monitoring, or control devices are integrated with infrastructure it is considered a cyber physical system, or CPS. When information about an important physical system is connected to the virtual world, it is opened up to security risks. Cyber security can be provided to the CPS by monitoring the physical state of the system …

Computer Gamification: Addressing Symptoms Of Inattentive Adhd In Children, Shavonne Victoria Halterman

Masters Theses

“Computer gamification has the potential to help meet the educational needs of children with Inattentive Attention Deficit/Hyperactivity disorder (ADHD). The elements of computer gamification are mapped to distinct kinds of interventions for Inattentive ADHD and show certain types of computer gamified learning are better than others for those who experience Inattentive ADHD”--Abstract, page iii.

Research And Development Of A Laser Hot Wire Deposition Process, Christopher Croft

Masters Theses

“Laser hot wire directed energy deposition (DED) is an increasingly popular method for improving deposition rates and overall reduction of build times in DED processing. While there is clear benefit, it is important to fully understand the impact of preheating the wire. This work focuses on developing a model that describes bead geometry output using all factors including the wire preheat. The model was fit with over 150 data points that explored a large range of each factor. The resulting model was then leveraged to evaluate a process control variable. The technique chosen used feedback from the hot wire system …

A Compact Wavelength Meter Using A Multimode Fiber, Ogbole Collins Inalegwu

Masters Theses

“Wavelength meters are very important for precision measurements of both pulses and continuous-wave optical sources. Conventional wavelength meters employ gratings, prisms, interferometers, and other wavelength-sensitive materials in their design. Here, we report a simple and compact wavelength meter based on a section of multimode fiber and a camera. The concept is to correlate the multimodal interference pattern (i.e., speckle pattern) at the end-face of a multimode fiber with the wavelength of the input lightsource. Through a series of experiments, specklegrams from the end face of a multimode fiber as captured by a charge-coupled device (CCD) camera were recorded; the images …

Analysis And Design Of Dc-Link Capacitor In Cascaded H-Bridge Multilevel Active Front-End Converter, Muhammad Shehroz Malik

Masters Theses

Medium-voltage grid-tied systems often use a cascaded H-bridge multi-level active front-end. In this converter, dc link bus capacitors play an important role in stabilizing the converter and enabling both active and reactive power injections. The present work provides analytical expressions for the capacitor current, which are essential for optimizing system design (especially capacitor size vs. lifetime). Then, the expression is incorporated into the grid connected bidirectional power system model. Consequently, this work contributes to the guiding principles to choose accurate dc link capacitor ratings against grid-side power delivery requirements.

DC-link capacitors come with an expiration date which is dependent on …

Physics-Based Modeling Of Lithium-Ion Batteries For Control And Estimation Applications, Brody J. C. Riemann

Masters Theses

“Lithium-ion batteries are extensively used in many application areas like consumer electronics, electric vehicles, and microgrids. As the world moves towards further electrification of vehicles and more widespread use of renewable energy sources, the need for large-scale battery storage systems will grow. To effectively replace conventional methods, batteries will need to be charged quickly while accounting for degradation to maximize lifetime. Further, larger batteries require more detailed safety monitoring, which is implemented using a battery management system (BMS). A BMS is responsible for state of charge (SOC) estimation, state of health (SOH) estimation, cell balancing, regulating voltage and current according …

Topological Biclustering Artmap, Raghu Yelugam

Masters Theses

”Detection of gene mutations is central for assessing genetic factors affecting disease predisposition, genetic causes of a particular disease, and gene-targeted treatment. DNA microarray methods are widely used to detect mutations by contrasting the expression levels of thousands of genes together under varying experimental conditions. The experimental conditions could be diseased cell states compared with the normal cell states. Biclustering, a robust exploratory data analysis tool, can be applied to microarray data to detect subsets of genes that co-express highly only for a subset of experimental conditions. Such detection is crucial for gaining insights into gene regulatory networks, differential gene …

Neural Network Supervised And Reinforcement Learning For Neurological, Diagnostic, And Modeling Problems, Donald Wunsch Iii

Masters Theses

“As the medical world becomes increasingly intertwined with the tech sphere, machine learning on medical datasets and mathematical models becomes an attractive application. This research looks at the predictive capabilities of neural networks and other machine learning algorithms, and assesses the validity of several feature selection strategies to reduce the negative effects of high dataset dimensionality. Our results indicate that several feature selection methods can maintain high validation and test accuracy on classification tasks, with neural networks performing best, for both single class and multi-class classification applications. This research also evaluates a proof-of-concept application of a deep-Q-learning network (DQN) to …

A Systematic Analysis Of Eye-Tracking Metrics For Sleepiness, Debasis Roy

Masters Theses

”Sleepiness or sleep deprivation is a serious hazard that can be life-threatening in carrying out certain tasks (e.g., when driving or executing attention-critical tasks). Eye movement can provide cues on sleepiness. Hence, eye-tracking metrics have the potential to detect sleepiness.

In this research, we used a systematic analysis approach to identify eye-tracking metrics for sleepiness. We used several databases to identify independent experimental studies that have used eye-tracking metrics to assess sleepiness. We identified 25 studies that included 674 participants where the participants’ data were captured both in an alert state and in a sleep-deprived state. In the analysis, we …

A Meta-Analysis: Gamification In Education, Yalin Wang

Masters Theses

“Gamification has been used in a variety of contexts including education. In order to understand the effects of gamification in education, a meta-analysis was conducted. A bottom-up approach was used to analyze the effects of game design elements on learning outcomes found in the literature search. The result suggests that gamification can enhance student learning outcomes. Elements such as points, leaderboards, competitions, progress bars, feedback, and collaboration have medium to large effect sizes. Gamification also has larger effects on young children in elementary education than learners at other education levels. The study offers suggestions and guidelines for educators on the …

Laser-Induced Electron Diffraction Of The Ultrafast Umbrella Motion In Ammonia, B. Belsa, K. Amini, X. Liu, A. Sanchez, J. Steinmetzer, Anh-Thu Le, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Visualizing molecular transformations in real-time requires a structural retrieval method with Ångström spatial and femtosecond temporal atomic resolution. Imaging of hydrogen-containing molecules additionally requires an imaging method sensitive to the atomic positions of hydrogen nuclei, with most methods possessing relatively low sensitivity to hydrogen scattering. Laser-induced electron diffraction (LIED) is a table-top technique that can image ultrafast structural changes of gas-phase polyatomic molecules with sub-Ångström and femtosecond spatiotemporal resolution together with relatively high sensitivity to hydrogen scattering. Here, we image the umbrella motion of an isolated ammonia molecule (NH3) following its strong-field ionization. Upon ionization of a neutral ammonia molecule, …

A Kinetic Evaluation For Phenothiazine Base Copolymers, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

In here, the non-isothermal decomposition kinetics of co-polymers-based phenothiazine was present-ed. For this, firstly, 3, 7-di-2-thienyl-10H-phenothiazine (TF) was prepared via an optimized Suzu-ki–Miyaura cross-coupling reaction. After monomer (TF) characterization, the copolymerization re-actions with EDOT and thiophene were performed by the electrochemical technique. The molecular masses of the co-polymers were found by gel permeation chromatography (GPC) analysis. Thermal characterizations of the resulting polymers were conducted by thermogravimetric analyses. The thermal decomposition kinetics of the resulting polymers was also performed. For this, the kinetic methods (Tang, FWO, KAS, Kissinger, and Friedman) based on the multiple heating rates were used. Several kinetic parameters …

Highly Porous Ceramic And Metal Aerogels From Xerogel Powder Precursors, And Methods For Thier Production And Use, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed, Parwani Rewatkar, Tahereh Taghvaee

Patents

The present invention discloses novel methods for producing highly porous ceramic and/or metal aerogel monolithic objects that are hard, sturdy, and resistant to high temperatures. These methods comprise preparing nanoparticulate oxides of metals and/or metalloids via a step of vigorous stirring to prevent gelation, preparing polymer-modified xerogel powder compositions by reacting said nanoparticulate oxides with one or more polyfunctional monomers, compressing said polymer-modified xerogel powder compositions into shaped compacts, and carbothermal conversion of the shaped xerogel compacts via pyrolysis to provide the highly porous ceramic and/or metal aerogel monolithic objects that have the same shapes as their corresponding xerogel compact …

Metal Foils With Ordered Crystal Structure And Method For Producing Metal Foils, Jay A. Switzer

Patents

A method for producing a metal foil comprising depositing metal onto an oxidizable substrate to form a metal film on the substrate; oxidizing the substrate at an interface between the metal film and the substrate; and removing the metal film from the substrate to yield a metal foil. A method for forming a thin metal film comprising pre-polarizing a single-crystal Si substrate by application of a potential which is negative of a potential at which Si oxidizes, which pre-polarization occurs in the presence of metal ions to form metal growth nucleation sites on the substrate, followed by application of a …