Physical Sciences and Mathematics Commons^™

Self-Image Multimedia Technologies For Feedforward Observational Learning, Nkiruka M. A. Uzuegbunam

Theses and Dissertations--Electrical and Computer Engineering

This dissertation investigates the development and use of self-images in augmented reality systems for learning and learning-based activities. This work focuses on self- modeling, a particular form of learning, actively employed in various settings for therapy or teaching. In particular, this work aims to develop novel multimedia systems to support the display and rendering of augmented self-images. It aims to use interactivity (via games) as a means of obtaining imagery for use in creating augmented self-images. Two multimedia systems are developed, discussed and analyzed. The proposed systems are validated in terms of their technical innovation and their clinical efficacy in …

Synthesis And Characterization Of Thermoresponsive Hydrogels Based On N-Isopropylacrylamide Crosslinked With 4,4′-Dihydroxybiphenyl Diacrylate, Shuo Tang, Martha Floy, Rohit Bhandari, Manjula Sunkara, Andrew J. Morris, Thomas D. Dziubla, J. Zach Hilt

Chemical and Materials Engineering Faculty Publications

A novel crosslinker [4,4′-dihydroxybiphenyl diacrylate (44BDA)] was developed, and a series of temperature-responsive hydrogels were synthesized through free radical polymerization of N-isopropylacrylamide (NIPAAm) with 44BDA. The temperature-responsive behavior of the resulting gels was characterized by swelling studies, and the lower critical solution temperature (LCST) of the hydrogels was characterized through differential scanning calorimetry. Increased content of 44BDA led to a decreased swelling ratio and shifted the LCST to lower temperatures. These novel hydrogels also displayed resiliency through multiple swelling–deswelling cycles, and their temperature responsiveness was reversible. The successful synthesis of NIPAAm-based hydrogels crosslinked with 44BDA has led to a …

Load Model Verification, Validation And Calibration Framework By Statistical Analysis On Field Data, Xiangqing Jiao, Yuan Liao, Thai Nguyen

Electrical and Computer Engineering Faculty Publications

Accurate load models are critical for power system analysis and operation. A large amount of research work has been done on load modeling. Most of the existing research focuses on developing load models, while little has been done on developing formal load model verification and validation (V&V) methodologies or procedures. Most of the existing load model validation is based on qualitative rather than quantitative analysis. In addition, not all aspects of model V&V problem have been addressed by the existing approaches. To complement the existing methods, this paper proposes a novel load model verification and validation framework that can systematically …

Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

The UKy-CAER team successfully tested an advanced 0.7 MWe post-combustion CO₂ capture system on a coal-fired power plant using a heat integration process combined with two-stage stripping to enhance the CO₂ absorber performance. One of the unique feature of the UKy-CAER integrated process is a two-stage stripping unit for solvent regeneration. The secondary stripper is empowered by the heat rejection from a conventional steam-heated (primary) stripper. The secondary stripper outlet stream at the commercial scale can be used as boiler secondary combustion air, consequently enriching the flue gas with CO₂, resulting in less energy penalty required …

Ionic Thermoelectric Paper, Fei Jiao, Ali Naderi, Dan Zhao, Joshua Schlueter, Maryam Shahi, Jonas Sundström, Hjalmar Granberg, Jesper Edberg, Ujwala Ail, Joseph W. Brill, Tom Lindström, Magnus Berggren, Xavier Crispin

Physics and Astronomy Faculty Publications

Ionic thermoelectric materials, for example, polyelectrolytes such as polystyrene sulfonate sodium (PSSNa), constitute a new class of materials which are attracting interest because of their large Seebeck coefficient and the possibility that they could be used in ionic thermoelectric SCs (ITESCs) and field effect transistors. However, pure polyelectrolyte membranes are not robust or flexible. In this paper, the preparation of ionic thermoelectric paper using a simple, scalable and cost-effective method is described. After a composite was fabricated with nanofibrillated cellulose (NFC), the resulting NFC–PSSNa paper is flexible and mechanically robust, which is desirable if it is to be used in …

Using A Respiratory Navigator Significantly Reduces Variability When Quantifying Left Ventricular Torsion With Cardiovascular Magnetic Resonance, Sean M. Hamlet, Christopher M. Haggerty, Jonathan D. Suever, Gregory J. Wehner, Kristin N. Andres, David K. Powell, Richard J. Charnigo, Brandon K. Fornwalt

Electrical and Computer Engineering Faculty Publications

Background: Left ventricular (LV) torsion is an important indicator of cardiac function that is limited by high inter-test variability (50% of the mean value). We hypothesized that this high inter-test variability is partly due to inconsistent breath-hold positions during serial image acquisitions, which could be significantly improved by using a respiratory navigator for cardiovascular magnetic resonance (CMR) based quantification of LV torsion.

Methods: We assessed respiratory-related variability in measured LV torsion with two distinct experimental protocols. First, 17 volunteers were recruited for CMR with cine displacement encoding with stimulated echoes (DENSE) in which a respiratory navigator was used to measure …

Autonomous Quadrotor Collision Avoidance And Destination Seeking In A Gps-Denied Environment, Thomas C. Kirven

Theses and Dissertations--Mechanical Engineering

This thesis presents a real-time autonomous guidance and control method for a quadrotor in a GPS-denied environment. The quadrotor autonomously seeks a destination while it avoids obstacles whose shape and position are initially unknown. We implement the obstacle avoidance and destination seeking methods using off-the-shelf sensors, including a vision-sensing camera. The vision-sensing camera detects the positions of points on the surface of obstacles. We use this obstacle position data and a potential-field method to generate velocity commands. We present a backstepping controller that uses the velocity commands to generate the quadrotor's control inputs. In indoor experiments, we demonstrate that the …

Hybrid Parallelization Of The Nasa Gemini Electromagnetic Modeling Tool, Buxton L. Johnson Sr.

Theses and Dissertations--Electrical and Computer Engineering

Understanding, predicting, and controlling electromagnetic field interactions on and between complex RF platforms requires high fidelity computational electromagnetic (CEM) simulation. The primary CEM tool within NASA is GEMINI, an integral equation based method-of-moments (MoM) code for frequency domain electromagnetic modeling. However, GEMINI is currently limited in the size and complexity of problems that can be effectively handled. To extend GEMINI’S CEM capabilities beyond those currently available, primary research is devoted to integrating the MFDlib library developed at the University of Kentucky with GEMINI for efficient filling, factorization, and solution of large electromagnetic problems formulated using integral equation methods. A secondary …

Real-Time Capture And Rendering Of Physical Scene With An Efficiently Calibrated Rgb-D Camera Network, Po-Chang Su

Theses and Dissertations--Electrical and Computer Engineering

From object tracking to 3D reconstruction, RGB-Depth (RGB-D) camera networks play an increasingly important role in many vision and graphics applications. With the recent explosive growth of Augmented Reality (AR) and Virtual Reality (VR) platforms, utilizing camera RGB-D camera networks to capture and render dynamic physical space can enhance immersive experiences for users. To maximize coverage and minimize costs, practical applications often use a small number of RGB-D cameras and sparsely place them around the environment for data capturing. While sparse color camera networks have been studied for decades, the problems of extrinsic calibration of and rendering with sparse RGB-D …

Enhanced Metallic Properties Of Srruo3 Thin Films Via Kinetically Controlled Pulsed Laser Epitaxy, Justin K. Thompson, J. Nichols, S. Lee, S. Ryee, John H. Gruenewald, John G. Connell, Maryam Souri, J. M. Johnson, J. Hwang, M. J. Han, H. N. Lee, D. -W. Kim, Sung S. Ambrose Seo

Physics and Astronomy Faculty Publications

Metal electrodes are a universal element of all electronic devices. Conducting SrRuO₃ (SRO) epitaxial thin films have been extensively used as electrodes in complex-oxide heterostructures due to good lattice mismatches with perovskite substrates. However, when compared to SRO single crystals, SRO thin films have shown reduced conductivity and Curie temperatures (T_C), which can lead to higher Joule heating and energy loss in the devices. Here, we report that high-quality SRO thin films can be synthesized by controlling the plume dynamics and growth rate of pulsed laser epitaxy (PLE) with real-time optical spectroscopic monitoring. The SRO thin …

An Interactive Videogame Designed To Improve Respiratory Navigator Efficiency In Children Undergoing Cardiovascular Magnetic Resonance, Sean M. Hamlet, Christopher M. Haggerty, Jonathan D. Suever, Gregory J. Wehner, Jonathan D. Grabau, Kristin N. Andres, Moriel H. Vandsburger, David K. Powell, Vincent L. Sorrell, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Background: Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient’s breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality.

Methods: We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The …

Capture And Recycle Of Industrial Co2 Emissions Using Mircoalgae, Michael H. Wilson, Daniel T. Mohler, John G. Groppo, Thomas E. Grubbs, Stephanie Kesner, E. Molly Frazar, Aubrey Shea, Czarena L. Crofcheck, Mark Crocker

Center for Applied Energy Research Faculty and Staff Publications

A novel cyclic flow photobioreactor (PBR) for the capture and recycle of CO₂ using microalgae was designed and deployed at a coal-fired power plant (Duke Energy’s East Bend Station). The PBR was operated continuously during the period May–September 2015, during which algae productivity of typically 0.1–0.2 g/(L day) was obtained. Maximum CO₂ capture efficiency was achieved during peak sunlight hours, the largest recorded CO₂ emission reduction corresponding to a value of 81 % (using a sparge time of 5 s/min). On average, CO₂ capture efficiency during daylight hours was 44 %. The PBR at East Bend …

Hallmarks Of The Mott-Metal Crossover In The Hole-Doped Pseudospin-1/2 Mott Insulator Sr2Iro4, Yue Cao, Qiang Wang, Justin A. Waugh, Theodore J. Reber, Haoxiang Li, Xiaoqing Zhou, Stephen Parham, S. -R. Park, Nicholas C. Plumb, Eli Rotenberg, Aaron Bostwick, Jonathan D. Denlinger, Tongfei Qi, Michael A. Hermele, Gang Cao, Daniel S. Dessau

Physics and Astronomy Faculty Publications

The physics of doped Mott insulators remains controversial after decades of active research, hindered by the interplay among competing orders and fluctuations. It is thus highly desired to distinguish the intrinsic characters of the Mott-metal crossover from those of other origins. Here we investigate the evolution of electronic structure and dynamics of the hole-doped pseudospin-1/2 Mott insulator Sr₂IrO₄. The effective hole doping is achieved by replacing Ir with Rh atoms, with the chemical potential immediately jumping to or near the top of the lower Hubbard band. The doped iridates exhibit multiple iconic low-energy features previously observed …

Information-Theoretic Secure Outsourced Computation In Distributed Systems, Zhaohong Wang

Theses and Dissertations--Electrical and Computer Engineering

Secure multi-party computation (secure MPC) has been established as the de facto paradigm for protecting privacy in distributed computation. One of the earliest secure MPC primitives is the Shamir's secret sharing (SSS) scheme. SSS has many advantages over other popular secure MPC primitives like garbled circuits (GC) -- it provides information-theoretic security guarantee, requires no complex long-integer operations, and often leads to more efficient protocols. Nonetheless, SSS receives less attention in the signal processing community because SSS requires a larger number of honest participants, making it prone to collusion attacks. In this dissertation, I propose an agent-based computing framework using …

An Organic Mixed Ion-Electron Conductor For Power Electronics, Abdellah Malti, Jesper Edberg, Hjalmar Granberg, Zia Ullah Khan, Jens W. Andreasen, Xianjie Liu, Dan Zhao, Hao Zhang, Yulong Yao, Joseph W. Brill, Isak Engquist, Mats Fahlman, Lars Wågberg, Xavier Crispin, Magnus Berggren

Physics and Astronomy Faculty Publications

A mixed ionic–electronic conductor based on nanofibrillated cellulose composited with poly(3,4-ethylene-dioxythio­phene):­poly(styrene-sulfonate) along with high boiling point solvents is demonstrated in bulky electrochemical devices. The high electronic and ionic conductivities of the resulting nanopaper are exploited in devices which exhibit record values for the charge storage capacitance (1F) in supercapacitors and transconductance (1S) in electrochemical transistors.

Ferromagnetic Resonance Study Of Eightfold Artificial Ferromagnetic Quasicrystals, Vinayak Shantaram Bhat, J. Sklenar, J. Woods, B. Farmer, J. B. Ketterson, Jeffrey Todd Hastings, Lance E. De Long

Physics and Astronomy Faculty Publications

We have performed broadband (10 MHz–18 GHz) and narrowband (9.7 GHz) ferromagnetic resonance (FMR) measurements on permalloy thin films patterned with quasiperiodic Ammann tilings having eightfold rotational symmetry. We observed highly reproducible mode structures in the low-frequency, hysteretic regime in which domain walls and unsaturated magnetization textures exist. A minimum of 10 robust modes were observed in patterned samples, compared to the single uniform mode observed in unpatterned permalloy films. The field dependence and approximate eightfold rotational symmetry of the FMR spectra are in good agreement with micromagnetic simulations that confirm the importance of patterning for controlling static and dynamic …

Co2 Recycling Using Microalgae For The Production Of Fuels, Michael H. Wilson, John Groppo, Andrew Placido, S. Graham, S. A. Morton Iii, Eduardo Santillan-Jimenez, Aubrey Shea, Mark Crocker, Czarena Crofcheck, Rodney Andrews

Center for Applied Energy Research Faculty and Staff Publications

CO₂ capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energy’s East Bend Station, Kentucky). Using an in-house designed closed loop, vertical tube photobioreactor, Scenedesmus acutus was cultured using flue gas as the CO₂ source. Algae productivity of 39 g/(m² day) in June–July was achieved at significant scale (18,000 L), while average daily productivity slightly in excess of 10 g/(m² day) was demonstrated in the month of December. A protocol for low-cost algae harvesting and dewatering was developed, and the conversion of algal lipids—extracted from the harvested biomass—to diesel-range hydrocarbons via catalytic …

Reference Compensation For Localized Surface-Plasmon Resonance Sensors, Neha Nehru

Theses and Dissertations--Electrical and Computer Engineering

Noble metal nanoparticles supporting localized surface plasmon resonances (LSPR) have been extensively investigated for label free detection of various biological and chemical interactions. When compared to other optical sensing techniques, LSPR sensors offer label-free detection of biomolecular interactions in localized sensing volume solutions. However, these sensors also suffer from a major disadvantage – LSPR sensors remain highly susceptible to interference because they respond to both solution refractive index change and non-specific binding as well as specific binding of the target analyte. These interactions can severely compromise the measurement of the target analyte in a complex unknown media and hence limit …

Modification Of Plasmonic Nano Structures' Absorption And Scattering Under Evanescent Wave Illumination Above Optical Waveguides Or With The Presence Of Different Material Nano Scale Atomic Force Microscope Tips, Gazi Mostafa Huda

Theses and Dissertations--Electrical and Computer Engineering

The interaction of an evanescent wave and plasmonic nanostructures are simulated in Finite Element Method. Specifically, the optical absorption cross section (C_abs) of a silver nanoparticle (AgNP) and a gold nanoparticle (AuNP) in the presence of metallic (gold) and dielectric (silicon) atomic force microscope (AFM) probes are numerically calculated in COMSOL. The system was illuminated by a transverse magnetic polarized, total internally reflected (TIR) waves or propagating surface plasmon (SP) wave. Both material nanoscale probes localize and enhance the field between the apex of the tip and the particle. Based on the absorption cross section equation the author …

Controlled Magnetic Reversal In Permalloy Films Patterned Into Artificial Quasicrystals, Vinayak Shantaram Bhat, J. Sklenar, B. Farmer, J. Woods, Jeffrey Todd Hastings, S. J. Lee, J. B. Ketterson, Lance E. De Long

Physics and Astronomy Faculty Publications

We have patterned novel Permalloy thin films with quasicrystalline Penrose P2 tilings and measured their dc magnetization and ferromagnetic resonance absorption. Reproducible anomalies in the hysteretic, low-field data signal a series of abrupt transitions between ordered magnetization textures, culminating in a smooth evolution into a saturated state. Micromagnetic simulations compare well to experimental dc hysteresis loops and ferromagnetic resonance spectra and indicate that systematic control of magnetic reversal and domain wall motion can be achieved via tiling design, offering a new paradigm of magnonic quasicrystals.

Influence Of Media Composition On The Growth Rate Of Chlorella Vulgaris And Scenedesmus Acutus Utilized For Co2 Mitigation, Czarena L. Crofcheck, Xinyi E, Aubrey Shea, Michael D. Montross, Mark Crocker, Rodney Andrews

Biosystems and Agricultural Engineering Faculty Publications

Atmospheric carbon dioxide levels have increased since the industrial revolution due to increasing combustion of fossil fuels. One possible CO₂ mitigation strategy is the use of microalgae for mitigation of CO₂. This paper focuses on the influence of media composition on the growth rate of two microalgae strains, Chlorella vulgaris and Scenedesmus actus. A KNO₃ based medium was found to work better for Chlorella, while a urea based equivalent worked better for Scenedesmus. The urea based media investigated here resulted in growth similar to that found with previously reported KNO₃ based media. …

Active Optimal Control Strategies For Increasing The Efficiency Of Photovoltaic Cells, Sharif Aljoaba

Theses and Dissertations--Electrical and Computer Engineering

Energy consumption has increased drastically during the last century. Currently, the worldwide energy consumption is about 17.4 TW and is predicted to reach 25 TW by 2035. Solar energy has emerged as one of the potential renewable energy sources. Since its first physical recognition in 1887 by Adams and Day till nowadays, research in solar energy is continuously developing. This has lead to many achievements and milestones that introduced it as one of the most reliable and sustainable energy sources. Recently, the International Energy Agency declared that solar energy is predicted to be one of the major electricity production energy …

Resource Allocation And Efficient Routing In Wireless Networks, Jianjun Yang

University of Kentucky Doctoral Dissertations

In wireless networks, devices (nodes) are connected by wireless links. An important issue is to set up high quality (high bandwidth) and efficient routing paths when one node wants to send packets to other nodes. Resource allocation is the foundation to guarantee high quality connections. In addition, it is critical to handle void areas in order to set up detour-free paths. Moreover, fast message broadcasting is essential in mobile wireless networks. Thus, my research includes dynamic channel allocation in wireless mesh networks, geographic routing in Ad Hoc networks, and message broadcasting in vehicular networks.

The quality of connections in a …

Near-Field Radiative Transfer: Thermal Radiation, Thermophotovoltaic Power Generation And Optical Characterization, Mathieu Francoeur

University of Kentucky Doctoral Dissertations

This dissertation focuses on near-field radiative transfer, which can be defined as the discipline concerned with energy transfer via electromagnetic waves at sub-wavelength distances. Three specific subjects related to this discipline are investigated, namely nearfield thermal radiation, nanoscale-gap thermophotovoltaic (nano-TPV) power generation and optical characterization. An algorithm for the solution of near-field thermal radiation problems in one-dimensional layered media is developed, and several tests are performed showing the accuracy, consistency and versatility of the procedure. The possibility of tuning near-field radiative heat transfer via thin films supporting surface phononpolaritons (SPhPs) in the infrared is afterwards investigated via the computation of …

Field Calibration Of A Transient Model For Broiler Misting, Richard S. Gates, Douglas G. Overhults, Robert W. Bottcher, Shu Hui Zhang

Biosystems and Agricultural Engineering Faculty Publications

A transient model to predict temperature within a tunnel ventilated broiler house during misting is developed. The model is calibrated with field data to obtain steady-state constants; transient predictions are compared to measured temperatures during cyclic misting for two different size birds. Measured temperatures during cyclic misting are shown to swing between steady-state asymptotes predicted from the model. Transient response of the model was faster than measured temperature data, in part due to temperature sensor dynamic response. The model predicts the length-wise temperature profile within the building during misting, and can be used to investigate alternate misting strategies and designs. …

Mechanical Backup Systems For Electronic Environmental Controllers, Richard S. Gates, Douglas G. Overhults, Larry W. Turner

Biosystems and Agricultural Engineering Faculty Publications

A series of mechanical backup systems for electronic environmental controllers is presented for a typical finishing swine barn and a typical tunnel ventilated broiler house. The systems consist of mechanical thermostats and timers used in parallel with the electronic controller, designed to ensure animal survival in the event of controller or related hardware failure. For swine housing, three distinct mechanical backup functions are identified; for broiler housing, four distinct mechanical backup functions are identified. Schematic diagrams of the mechanical backup functions are provided and their implementation is described.

A Survey Of Electronic Environmental Controllers, Richard S. Gates, Douglas G. Overhults, Larry W. Turner

Biosystems and Agricultural Engineering Faculty Publications

Sixteen commercially available electronic environmental controllers were evaluated. The units were classified according to enclosure type, analog versus microprocessor based control, power supply, sensors, alarms, control relays and triac output, interval timers, outside temperature feedback, and retail price. An assessment of these controllers indicated several critical limitations in the application of this technology.

The use of integrated controllers for animal production has the potential for substantial improvements in production efficiencies. If the limitations observed in the present controller technology, as represented by this sample, are addressed, industry acceptance of the technology can be accelerated. A uniform standard to address this …

Transient Overvoltage Testing Of Environmental Controllers, Richard S. Gates, Larry W. Turner, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

The integrated electronic control system will provide a new method for the day-to-day management of environmental control of animal production systems. No standards are currently accepted for transient overvoltage protection of these controllers. To assess the adequacy of existing designs, a test circuit was designed and used for a transient open circuit over-voltage waveform (ANSI/IEEE C62.41-1980) of 16 environmental control units: a maximum spike of 770 V was applied to the power supplies, and a spike up to 100 V was applied to temperature sensor lines. For these relatively mild tests, no failures were noted due to power supply transients, …