Physical Sciences and Mathematics Commons^™

Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar

Graduate Theses and Dissertations

Energy security through increased biofuel production is one of the components of the Energy Independence and Security Act (EISA) 2007. As per EISA 2007 mandate, appropriate independent research institutes are required to assess concerns to natural biodiversity due to biofuel production and report it to the Congress through the Environment Protection Agency (EPA). Planners, researchers, and agencies concerned with environmental regulations, ideally, would like to have location-specific information about the impacts for developing appropriate management interventions. This study examines long-term impacts on water quality in response to targeted (i.e. marginal lands) production of biofuel crops by setting up two SWAT …

The Effects Of Strain And Vacancies On The Electric And Vibrational Properties Of Ferroelectric Batio3 From First-Principles, Aldo Serge Michael Raeliarijaona

Graduate Theses and Dissertations

The studies of ferroelectricity (FE) are of technological significance because of the multitude of applicable properties that ferroelectric materials exhibit. The mastery, and control of these properties necessitate the knowledge of the fundamental physics governing these insulating materials.

In this dissertation I present the results of first-principles investigations of the behavior of the fundamental ferroelectric properties under strain, and in the presence of vacancies. In the first part I introduce the important FE properties, their common behavior, and their numerous valuable applications. Following this background on FEs, a review of theoretical methods is presented with topics such as: Density Functional …

Experimental Verification And Integration Of A Next Generation Smart Power Management System, Tavis Clemmer

Graduate Theses and Dissertations

With the increase in energy demand by the residential community in this country and the diminishing fossil fuel resources being used for electric energy production there is a need for a system to efficiently manage power within a residence. The Smart Green Power Node (SGPN) is a next generation energy management system that automates on-site energy production, storage, consumption, and grid usage to yield the most savings for both the utility and the consumer. Such a system automatically manages on-site distributed generation sources such as a PhotoVoltaic (PV) input and battery storage to curtail grid energy usage when the price …

Top-Down Aluminum Induced Crystallization For Photovoltaics, Seth Daniel Shumate

Graduate Theses and Dissertations

Passivating silicon solar cell surfaces is critical to fabricating very high efficiency and low cost photovoltaic devices. The sun-facing surface of the solar cell, known as the emitter, is particularly important when designing a solar cell. This work focused first on an alternative method of forming the emitter of silicon solar cells, and secondly on a method for improving the surface passivation of both these non-traditional and standard n-type solar cells.

Top-down aluminum induced crystallization (TAIC) was used for forming a polycrystalline silicon layer from amorphous silicon using aluminum to catalyze the crystallization at much lower temperatures than otherwise possible. …

Enhancement Of The Performance Of Gaas Based Solar Cells By Using Plasmonic, Anti-Reflection Coating And Hydrophobic Effects, Yahia Fayiz Makableh

Graduate Theses and Dissertations

Investigation of renewable energy resources is gaining huge momentum in recent years due to the limited fossil fuels, and their detriment impact on the environment. Solar energy is promising to meet the increased energy demand. In order to achieve this goal, solar energy has to be harvested efficiently at low cost. Therefore, higher efficiency solar cells are the primary focus of research worldwide. Photovoltaics based on InAs/GaAs intermediate band solar cells and their device performance enhancements are investigated in this dissertation. The device enhancement is carried out by surface modification methods. The dissertation work is inspired by the need of …

Enabling Runtime Self-Coordination Of Reconfigurable Embedded Smart Cameras In Distributed Networks, Franck Ulrich Yonga Yonga

Graduate Theses and Dissertations

Smart camera networks are real-time distributed embedded systems able to perform computer vision using multiple cameras. This new approach is a confluence of four major disciplines (computer vision, image sensors, embedded computing and sensor networks) and has been subject of intensive work in the past decades. The recent advances in computer vision and network communication, and the rapid growing in the field of high-performance computing, especially using reconfigurable devices, have enabled the design of more robust smart camera systems. Despite these advancements, the effectiveness of current networked vision systems (compared to their operating costs) is still disappointing; the main reason …

Design And Verification Environment For High-Performance Video-Based Embedded Systems, Michael Mefenza Nentedem

Graduate Theses and Dissertations

In this dissertation, a method and a tool to enable design and verification of computation demanding embedded vision-based systems is presented. Starting with an executable specification in OpenCV, we provide subsequent refinements and verification down to a system-on-chip prototype into an FPGA-Based smart camera. At each level of abstraction, properties of image processing applications are used along with structure composition to provide a generic architecture that can be automatically verified and mapped to the lower abstraction level. The result is a framework that encapsulates the computer vision library OpenCV at the highest level, integrates Accelera's System-C/TLM with UVM and QEMU-OS …

A New Design Method For Vanadium Redox Batteries In Renewable Energy Systems, Casey Gibson, Karla G. Morrissey Unversity Of Arkansas, Fayetteville

Inquiry: The University of Arkansas Undergraduate Research Journal

This study investigated the behavior of vanadium redox flow batteries (VRFBs), which are batteries capable of easily switching between charging and discharging modes, making them a suitable option for storing intermittent sources of alternative energies (solar, wind, etc). Since different sizes of the battery provide varying voltages, optimal parameters for a particular home are key for implementation. These parameters, specifically the cell and tank volumes of the battery that are capable of providing consistent on-load voltage, were determined using data from a 13 kW solar array and a medium-sized house. Charge/discharge current values were used to run a mathematical model …