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Solid-State Compatibilization Of Immiscible Polymer Blends: Cryogenic Milling And Solid-State Shear Pulverization, Marc Frederick Henry 2010 Bucknell University

Solid-State Compatibilization Of Immiscible Polymer Blends: Cryogenic Milling And Solid-State Shear Pulverization, Marc Frederick Henry

Master’s Theses

The blending of common polymers allows for the rapid and facile synthesis of new materials with highly tunable properties at a fraction of the costs of new monomer development and synthesis. Most blends of polymers, however, are completely immiscible and separate into distinct phases with minimal phase interaction, severelydegrading the performance of the material. Cross-phase interactions and property enhancement can be achieved with these blends through reactive processing or compatibilizer addition. A new class of blend compatibilization relies on the mechanochemical reactions between polymer chains via solid-state, high energy processing. Two contrasting mechanochemical processing techniques are explored in this thesis ...


Experimental Studies Of Liquefaction And Densification Of Liquid Oxygen, Jonathan Koert Partridge 2010 University of Central Florida

Experimental Studies Of Liquefaction And Densification Of Liquid Oxygen, Jonathan Koert Partridge

Electronic Theses and Dissertations, 2004-2019

Rocketry employs cryogenic refrigeration to increase the density of propellants, such as oxygen, and stores the propellant as a liquid. In addition to propellant liquefaction, cryogenic refrigeration can also conserve propellant and provide propellant subcooling and densification. Previous studies analyzed vapor conditioning of a cryogenic propellant, which occurred by either a heat exchanger positioned in the vapor or by using the vapor as the working fluid in a refrigeration cycle. This study analyzes the refrigeration effects of a heat exchanger located beneath the vapor-liquid interface of liquid oxygen. This study predicts the mass liquefaction rate and heat transfer coefficient for ...


Live Video Database Management Systems, Rui Peng 2010 University of Central Florida

Live Video Database Management Systems, Rui Peng

Electronic Theses and Dissertations, 2004-2019

With the proliferation of inexpensive cameras and the availability of high-speed wired and wireless networks, networks of distributed cameras are becoming an enabling technology for a broad range of interdisciplinary applications in domains such as public safety and security, manufacturing, transportation, and healthcare. Today’s live video processing systems on networks of distributed cameras, however, are designed for specific classes of applications. To provide a generic query processing platform for applications of distributed camera networks, we designed and implemented a new class of general purpose database management systems, the live video database management system (LVDBMS). We view networked video cameras ...


The Next Generation Botnet Attacks And Defenses, Ping Wang 2010 University of Central Florida

The Next Generation Botnet Attacks And Defenses, Ping Wang

Electronic Theses and Dissertations, 2004-2019

A "botnet" is a network of compromised computers (bots) that are controlled by an attacker (botmasters). Botnets are one of the most serious threats to today’s Internet; they are the root cause of many current Internet attacks, such as email spam, distributed denial of service (DDoS) attacks , click fraud, etc. There have been many researches on how to detect, monitor, and defend against botnets that have appeared and their attack techniques. However, it is equally important for us to investigate possible attack techniques that could be used by the next generation botnets, and develop effective defense techniques accordingly in ...


Quantum Dot Based Mode-Locked Semiconductor Lasers And Applications, Jimyung Kim 2010 University of Central Florida

Quantum Dot Based Mode-Locked Semiconductor Lasers And Applications, Jimyung Kim

Electronic Theses and Dissertations, 2004-2019

In this dissertation, self-assembled InAs/InGaAs quantum dot Fabry-Perot lasers and mode-locked lasers are investigated. The mode-locked lasers investigated include monolithic and curved two-section devices, and colliding pulse mode-locked diode lasers. Ridge waveguide semiconductor lasers have been designed and fabricated by wet etching processes. Electroluminescence of the quantum dot lasers is studied. Cavity length dependent lasing via ground state and/or excited state transitions is observed from quantum dot lasers and the optical gain from both transitions is measured. Stable optical pulse trains via ground and excited state transitions are generated using a grating coupled external cavity with a curved ...


Architectural Support For Improving Computer Security, Jingfei Kong 2010 University of Central Florida

Architectural Support For Improving Computer Security, Jingfei Kong

Electronic Theses and Dissertations, 2004-2019

Computer security and privacy are becoming extremely important nowadays. The task of protecting computer systems from malicious attacks and potential subsequent catastrophic losses is, however, challenged by the ever increasing complexity and size of modern hardware and software design. We propose several methods to improve computer security and privacy from architectural point of view. They provide strong protection as well as performance efficiency. In our first approach, we propose a new dynamic information flow method to protect systems from popular software attacks such as buffer overflow and format string attacks. In our second approach, we propose to deploy encryption schemes ...


Digital Pulse Width Modulator Techniques For Dc - Dc Converters, Majd Batarseh 2010 University of Central Florida

Digital Pulse Width Modulator Techniques For Dc - Dc Converters, Majd Batarseh

Electronic Theses and Dissertations, 2004-2019

Recent research activities focused on improving the steady-state as well as the dynamic behavior of DC-DC converters for proper system performance, by proposing different design methods and control approaches with growing tendency to using digital implementation over analog practices. Because of the rapid advancement in semiconductors and microprocessor industry, digital control grew in popularity among PWM converters and is taking over analog techniques due to availability of fast speed microprocessors, flexibility and immunity to noise and environmental variations. Furthermore, increased interest in Field Programmable Gate Arrays (FPGA) makes it a convenient design platform for digitally controlled converters. The objective of ...


A Study Of The Strength Of Pervious Pavement Systems, Ikenna Uju 2010 University of Central Florida

A Study Of The Strength Of Pervious Pavement Systems, Ikenna Uju

Electronic Theses and Dissertations, 2004-2019

This thesis presents a study on the strength properties of the different pervious pavement systems installed at the Stormwater Management Academy field laboratory at University of Central Florida (UCF), Orlando. The strength tests were performed both in the laboratory and in the field. Laboratory testing was conducted to determine the compressive strength and flexural strength of the various pavement surfaces. Evaluation of field pavement performance was performed by comparing the deflection basins using the Falling Weight Deflectometer test on pervious concrete and porous asphalt with conventional impervious concrete and asphalt pavements of similar layer profile and thickness, respectively. From literature ...


Fabrication Of Integrated Optofluidic Circuits In Chalcogenide Glass Using Femtosecond Laser Direct Writing, Troy P. Anderson 2010 University of Central Florida

Fabrication Of Integrated Optofluidic Circuits In Chalcogenide Glass Using Femtosecond Laser Direct Writing, Troy P. Anderson

Electronic Theses and Dissertations, 2004-2019

Femtosecond laser direct writing (FLDW) is a versatile process that uses focused femtosecond pulses to modify the physical structure of a material, which can result in a shift of optical properties such as the linear and nonlinear refractive index. If the photon energy of the femtosecond pulses lies below the material bandgap, nonlinear absorption rather than linear absorption becomes the dominant mechanism of energy transfer to the material. In this manner, a focused femtosecond pulse train can be used to fabricate functional features such as optical waveguides, diffractive optical elements, or micro-fluidic elements within the volume of a transparent medium ...


Study Of The Interactions Of Proteins, Cells And Tissue With Biomaterials, Abhijeet Bhalkikar 2010 University of Central Florida

Study Of The Interactions Of Proteins, Cells And Tissue With Biomaterials, Abhijeet Bhalkikar

Electronic Theses and Dissertations, 2004-2019

Bioengineering is the application of engineering principles to address challenges in the fields of biology and medicine. Biomaterials play a major role in bioengineering. This work employs a three level approach to study the various interactions of biomaterials with proteins, cells and tissue in vitro. In the first study, we qualitatively and quantitatively analyzed the process of protein adsorption of two enzymes to two different surface chemistries, which are commonly used in the field. In the second study, we attempted to engineer a tissue construct to build a biocompatible interface between a titanium substrate and human skin. In the third ...


High-Density And High-Efficiency Soft Switching Modular Bi-Directional Dc-Dc Converter For Hybrid Electric Vehicles, John Elmes 2010 University of Central Florida

High-Density And High-Efficiency Soft Switching Modular Bi-Directional Dc-Dc Converter For Hybrid Electric Vehicles, John Elmes

Electronic Theses and Dissertations, 2004-2019

This dissertation1 presents the design of a high-density and high-efficiency soft-switching bi-directional DC-DC converter for hybrid-electric vehicles. The converter operates in a new bidirectional interleaved variable-frequency quasi-square-wave (QSW) mode, which enables high efficiency, high switching frequency, and high power-density. The converter presented utilizes a new variable frequency interleaving approach which allows for each module to operate in an interleaved position while allowing for tolerance in inductance and snubber capacitor values. The variable frequency interleaved soft-switching operation paired with a high-density nanocrystalline inductor and high-density system structure results in a very high performance converter, well exceeding that of the current technology ...


Toward A Real-Time Celestial Body Information System, Brian Mitchell Guise 2010 University of Central Florida

Toward A Real-Time Celestial Body Information System, Brian Mitchell Guise

Electronic Theses and Dissertations, 2004-2019

The National Aeronautics and Space Administration maintains a challenging schedule of planned and on-going space exploration missions that extend to the outer reaches of our galaxy. New missions represent a huge investment, in terms of actual costs for equipment and support infrastructure, and personnel training. The success of a mission is critical considering both the monetary investment, and for manned missions, the lives which are put at risk. Tragedies involving Challenger, Columbia, Apollo 7, and the near tragedy of Apollo 13 exemplify that space exploration is a dangerous endeavor, posing extreme environmental conditions on both equipment and personnel. NASA, the ...


A Fpga-Based Architecture For Led Backlight Driving, Zhaoshi Zheng 2010 University of Central Florida

A Fpga-Based Architecture For Led Backlight Driving, Zhaoshi Zheng

Electronic Theses and Dissertations, 2004-2019

In recent years, Light-emitting Diodes (LEDs) have become a promising candidate for backlighting Liquid Crystal Displays [1] (LCDs). Compared with traditional Cold Cathode Fluorescent Lamps (CCFLs) technology, LEDs offer not only better visual quality, but also improved power efficiency. However, to fully utilized LEDs' capability requires dynamic independent control of individual LEDs, which remains as a challenging topic. A FPGA-based hardware system for LED backlight control is proposed in this work. We successfully achieve dynamic adjustment of any individual LED's intensity in each of the three color channels (Red, Green and Blue), in response to a real time incoming ...


Reactive Control Of Autonomous Dynamical Systems, Jiangmin Chunyu 2010 University of Central Florida

Reactive Control Of Autonomous Dynamical Systems, Jiangmin Chunyu

Electronic Theses and Dissertations, 2004-2019

This thesis mainly consists of five independent papers concerning the reactive control design of autonomous mobile robots in the context of target tracking and cooperative formation keeping with obstacle avoidance in the static/dynamic environment. Technical contents of this thesis are divided into three parts. The first part consists of the first two papers, which consider the target-tracking and obstacle avoidance in the static environment. Especially, in the static environment, a fundamental issue of reactive control design is the local minima problem(LMP) inherent in the potential field methods(PFMs). Through introducing a state-dependent planned goal, the first paper proposes ...


Learning From Geometry In Learning For Tactical And Strategic Decision Domains, Jason Gauci 2010 University of Central Florida

Learning From Geometry In Learning For Tactical And Strategic Decision Domains, Jason Gauci

Electronic Theses and Dissertations, 2004-2019

Artificial neural networks (ANNs) are an abstraction of the low-level architecture of biological brains that are often applied in general problem solving and function approximation. Neuroevolution (NE), i.e. the evolution of ANNs, has proven effective at solving problems in a variety of domains. Information from the domain is input to the ANN, which outputs its desired actions. This dissertation presents a new NE algorithm called Hypercube-based NeuroEvolution of Augmenting Topologies (HyperNEAT), based on a novel indirect encoding of ANNs. The key insight in HyperNEAT is to make the algorithm aware of the geometry in which the ANNs are embedded ...


On The Benefits Of In-Flight System Identification For Autonomous Airdrop Systems, Michael Ward, Mark Costello, Nathan Slegers 2010 Georgia Institute of Technology - Main Campus

On The Benefits Of In-Flight System Identification For Autonomous Airdrop Systems, Michael Ward, Mark Costello, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

A unique feature of airdrop systems is the inherent and large variability in flight dynamic characteristics. The same physical article dropped on two different occasions will exhibit significantly different dynamic response. The problem only becomes worse for different test articles. Control systems for autonomous airdrop systems explicitly or implicitly assume knowledge of the flight dynamic characteristics in some way, shape, or form. A question facing autonomous airdrop designers is whether to use precomputed dynamic characteristics inside the control law, or to compute the needed flight dynamic characteristics in-flight and subsequently employ them in the control law. This paper establishes conditions ...


Probabilistic Models For Short Term Traffic Conditions Prediction, Yan Qi 2010 Louisiana State University and Agricultural and Mechanical College

Probabilistic Models For Short Term Traffic Conditions Prediction, Yan Qi

LSU Doctoral Dissertations

Accurate short-term prediction of traffic condition on freeways and major arterials has become increasingly important because of its vital role in traffic management functions and various trip decisions. Given the dynamic nature of freeway traffic, this study proposed two stochastic model approaches, Hidden Markov Model (HMM) and One-Step Stochastic Model, for short-term traffic prediction during peak periods. The data used in the study are real-time traffic monitoring data gathered over 6 years on a 40-mile segment of Interstate-4 in Orlando, Florida. Both approaches are based on the traffic state transition probabilities. The HMM approach defines traffic states in a two ...


The Effect Of Anisotropic Surface Energy On The Stability Of Micro And Nano Wires, Ping Du 2010 Louisiana State University and Agricultural and Mechanical College

The Effect Of Anisotropic Surface Energy On The Stability Of Micro And Nano Wires, Ping Du

LSU Doctoral Dissertations

A liquid thread of radius R will break up into drops if the axial wavelength of the surface perturbation L > 2πR. If L < 2πR, the thread is stable and will remain intact. This is Rayleigh’s stability criterion based on a continuum model. We use molecular dynamics to simulate the evolution of Lennard-Jones liquid threads with equilibrium radius R = 2.3-6.6, where R has been non-dimensionalized by the distance at which the Lennard-Jones potential equals zero. We find that if R is fixed, the wavelength L is bounded by Lmin and Lmax. For L > Lmax the thread always breaks up and stays as drops, and for L < Lmin the thread remains intact. However, for Lmin < L < Lmax, the thread oscillates continuously among several shapes. The appearance of various shapes can be explained by the energy fluctuation of the system.

We also simulate the evolution of Lennard-Jones nanowires with equilibrium radius R = 1.57, 2.58, 3.59, and 4.60 by molecular dynamics. The ...


Fabrication, Characterization, Modeling And Testing Of A Nanostructured Bulk Thermoelectric Cooler, Dinesh Pinisetty 2010 Louisiana State University and Agricultural and Mechanical College

Fabrication, Characterization, Modeling And Testing Of A Nanostructured Bulk Thermoelectric Cooler, Dinesh Pinisetty

LSU Doctoral Dissertations

New generation micro/nano devices are emerging to monitor, control and act on living systems. Particularly, in the field of cryobiology, there is a need to monitor and control temperature at the cellular level. An important step towards achieving this aim is to fabricate a novel bulk nanostructured thermoelectric cooler (TEC). As a first step towards achieving efficient localized control of temperature in biological systems, Bismuth-telluride (Bi2Te3) and Antimony-Telluride (Sb2Te3) arrays of nanowires and nanotubes were fabricated, characterized and modeled. A thermal conductivity model originally developed by Dames and Chen for superlattice nanowires was extended to nanotubes. Based on this ...


Integrating Bioprocesses Into Industrial Complexes For Sustainable Development, Debalina Sengupta 2010 Louisiana State University and Agricultural and Mechanical College

Integrating Bioprocesses Into Industrial Complexes For Sustainable Development, Debalina Sengupta

LSU Doctoral Dissertations

The objective of this research is to propose, develop and demonstrate a methodology for the optimal integration of bioprocesses in an existing chemical production complex. Chemical complex optimization is determining the optimal configuration of chemical plants in a superstructure of possible plants based on economic, environmental and sustainable criteria objective function (triple bottomline) and solves a mixed integer non linear programming problem. This research demonstrated the transition of production of chemicals from non-renewable to renewable feedstock. A conceptual design of biochemical processes was converted to five industrial scale designs in Aspen HYSYS® process simulator. Fourteen input-output block models were created ...


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