Engineering Commons^™

Self-Assembled Supramolecular Structures Of Chiral Phospholipids: Structure, Mechanical Properties And Patterning, Nidhi Mahajan

Electronic Theses and Dissertations

Lipid molecule is well known natural building block to form different supramolecular structures with specific shape, size and functionality. In my thesis work, I have used DC8,9PC 1,2-bis(tricosa-10,12-dinoyl)-sn-glycero-3-phosphocholine), a type of chiral lipid to form the vesicles, tubules and ribbons . By using Atomic Force Microscope, I have studied the morphological features of these particular structures. Also, the mechanical properties of lipid tubules have been studied using AFM. Softlithography has been used to pattern the lipid vesicles and tubules into 2-dimensional and 3-dimensional ordered arrays. The structure of self-assembled hollow spherical vesicles was studied using AFM. The applications of soft …

A Dynamic Model Of The Human/Cooling System/Clothing/Environment System, Zhengxiang Pu

Electronic Theses and Dissertations

The human body compensates well for moderate climatic heat stress, but artificial environments often block or overwhelm physiological defense mechanism. Personal protective equipment (PPE) is one of sources of heat stress. It protects individual from chemical, physical, or biological hazards, but the high thermal insulation and low vapor permeability of PPE may also lead to substantial heat stress. Personal cooling is widely used to alleviate heat stress, especially for those situations where ambient environmental cooling is not economically viable or feasible. It is important to predict the physiological responses of a person wearing PPE with personal cooling to make sure …

Differential Radio Link Protocol: An Improvement To Tcp Over Wireless Networks, Jaideep Sarkar

Electronic Theses and Dissertations

New generations of wireless cellular networks, including 3G and 4G technologies, are envisaged to support more mobile users and a variety of wireless multimedia services. With an increasing demand for wireless multimedia services, the performance of TCP becomes a bottleneck as it cannot differentiate between the losses due to the nature of air as a medium and high data load on the network that leads to congestion. This misinterpretation by TCP leads to a reduction in the congestion window size thereby resulting in reduced throughput of the system. To overcome this scenario Radio Link Protocols are used at a lower …

Famtile: An Algorithm For Learning High-Level Tactical Behavior From Observation, Brian Stensrud

Electronic Theses and Dissertations

This research focuses on the learning of a class of behaviors defined as high-level behaviors. High-level behaviors are defined here as behaviors that can be executed using a sequence of identifiable behaviors. Represented by low-level contexts, these behaviors are known a priori to learning and can be modeled separately by a knowledge engineer. The learning task, which is achieved by observing an expert within simulation, then becomes the identification and representation of the low-level context sequence executed by the expert. To learn this sequence, this research proposes FAMTILE - the Fuzzy ARTMAP / Template-Based Interpretation Learning Engine. This algorithm attempts …

Integration Of Real-Time Experiments With Internet Access, Pavan Talakala

Electronic Theses and Dissertations

The revolution of Internet – enabled instrumentation is emerging as a revolution in Measurement and Automation. New standards are being developed for transmitting data and connecting instruments to the Internet. The main purpose of this thesis is to design and develop a system to Integrate various Real – time experiments and be able to monitor and control them over Internet using LabVIEW. LabVIEW is a graphical programming package capable of data acquisition, data analysis, data presentation and real time remote control. In this thesis a Real – time system is developed which integrates several real time experiments and remote control …

Developing An Object-Oriented Approach For Operations Simulation In Speedes, Amit Wasadikar

Electronic Theses and Dissertations

Using simulation techniques, performance of any proposed system can be tested for different scenarios with a generated model. However, it is difficult to rapidly create simulation models that will accurately represent the complexity of the system. In recent years, Object-Oriented Discrete-Event Simulation has emerged as the potential technology to implement rapid simulation schemes. A number of software based on programming languages like C++ and Java are available for carrying out Object Oriented Discrete-Event Simulation. These software packages establish a general framework for simulation in computer programs, but need to be further customized for desired end-use applications. In this thesis, a …

System Design And Optimization Of Optical Coherence Tomography, Avni Ceyhun Akcay

Electronic Theses and Dissertations

Optical coherence imaging, including tomography (OCT) and microscopy (OCM), has been a growing research field in biomedical optical imaging in the last decade. In this imaging modality, a broadband light source, thus of short temporal coherence length, is used to perform imaging via interferometry. A challenge in optical coherence imaging, as in any imaging system towards biomedical diagnosis, is the quantification of image quality and optimization of the system components, both a primary focus of this research. We concentrated our efforts on the optimization of the imaging system from two main standpoints: axial point spread function (PSF) and practical steps …

Interferometry-Based Free Space Communication And Information Processing, Muzamil Arshad Arain

Electronic Theses and Dissertations

This dissertation studies, analyzes, and experimentally demonstrates the innovative use of interference phenomenon in the field of opto-electronic information processing and optical communications. A number of optical systems using interferometric techniques both in the optical and the electronic domains has been demonstrated in the filed of signal transmission and processing, optical metrology, defense, and physical sensors. Specifically it has been shown that the interference of waves in the form of holography can be exploited to realize a novel optical scanner called Code Multiplexed Optical Scanner (C-MOS). The C-MOS features large aperture, wide scan angles, 3-D beam control, no moving parts, …

Explanations In Contextual Graphs: A Solution To Accountability In Knowledge Based Systems, Brian W. Sherwell

Electronic Theses and Dissertations

In order for intelligent systems to be a viable and utilized tool, a user must be able to understand how the system comes to a decision. Without understanding how the system arrived at an answer, a user will be less likely to trust its decision. One way to increase a user's understanding of how the system functions is by employing explanations to account for the output produced. There have been attempts to explain intelligent systems over the past three decades. However, each attempt has had shortcomings that separated the logic used to produce the output and that used to produce …

Network Intrusion Detection: Monitoring, Simulation And Visualization, Mian Zhou

Electronic Theses and Dissertations

This dissertation presents our work on network intrusion detection and intrusion sim- ulation. The work in intrusion detection consists of two different network anomaly-based approaches. The work in intrusion simulation introduces a model using explicit traffic gen- eration for the packet level traffic simulation. The process of anomaly detection is to first build profiles for the normal network activity and then mark any events or activities that deviate from the normal profiles as suspicious. Based on the different schemes of creating the normal activity profiles, we introduce two approaches for intrusion detection. The first one is a frequency-based approach which …

Modeling Satellite Formations In The Presence Of Perturbations, Robert Cannaday

Electronic Theses and Dissertations

The potential benefits of autonomous satellite formation flying in such areas as high- resolution remote sensing, and sparse aperture radar, has stimulated interest in modeling the satellite environment for feasibility and simulation studies to help explore and define the technical challenges that must be solved in order to achieve successful autonomous satellite formations. The purpose of this paper is to develop and describe a numerical simulation of the orbital environment including central force field perturbations and atmospheric drag effects which will be a useful analytical tool for investigating issues relating to maintaining satellite formations in low-earth-orbit. Many of the studies …

Evaluating Ramp Metering And Variable Speed Limits To Reduce Crash Potential On Congested Freeways Using Micro-Simulation, Albinder Dhindsa

Electronic Theses and Dissertations

Recent research at UCF into defining surrogate measures for identifying crash prone conditions on freeways has led to the introduction of several statistical models which can flag such conditions with a good degree of accuracy. Outputs from these models have the potential to be used as real-time safety measures on freeways. They may also act as the basis for the evaluation of several intervention strategies that might help in the mitigation of risk of crashes. Ramp Metering and Variable Speed Limits are two approaches which have the potential of becoming effective implementation strategies for improving the safety conditions on congested …

An Inverse Algorithm To Estimate Thermal Contact Resistance, Jennifer Gill

Electronic Theses and Dissertations

Thermal systems often feature composite regions that are mechanically mated. In general, there exists a significant temperature drop across the interface between such regions which may be composed of similar or different materials. The parameter characterizing this temperature drop is the thermal contact resistance, which is defined as the ratio of the temperature drop to the heat flux normal to the interface. The thermal contact resistance is due to roughness effects between mating surfaces which cause certain regions of the mating surfaces to loose contact thereby creating gaps. In these gap regions, the principal modes of heat transfer are conduction …

Optical Wave Propagation In Discrete Waveguide Arrays, Jared Hudock

Electronic Theses and Dissertations

The propagation dynamics of light in optical waveguide arrays is characteristic of that encountered in discrete systems. As a result, it is possible to engineer the diffraction properties of such structures, which leads to the ability to control the flow of light in ways that are impossible in continuous media. In this work, a detailed theoretical investigation of both linear and nonlinear optical wave propagation in one- and two-dimensional waveguide lattices is presented. The ability to completely overcome the effects of discrete diffraction through the mutual trapping of two orthogonally polarized coherent beams interacting in Kerr nonlinear arrays of birefringent …

Micromachined Electrochemical Sensors For Hydrogen Peroxide And Chlorine Detection, Anjum Mehta

Electronic Theses and Dissertations

Hydrogen peroxide and chlorine detection is critical for many biological and environmental applications. Hydrogen peroxide plays important roles in a variety of fields including plant physiology, medical, environmental and biochemical applications. Its role in plant defense and signal transduction, diseases such as Parkinson's and Alzhemier's, industrial processes such as disinfection and wastewater treatment and biochemical enzymatic reactions is critical. Given the gamut of areas that hydrogen peroxide is a key component of; its detection assumes great importance. Similarly chlorine has long been used as a disinfectant for making drinking water safe, but excessive chlorination is an environmental and health hazard …

Structural Evolution In Mechanically Alloyed Fe-Based Powder Systems, Umesh Patil

Electronic Theses and Dissertations

A systematic study of iron-based binary and multi-component alloys was undertaken to study the structural evolution in these powders as a function of milling time during mechanical alloying. Blended elemental powders of Fe100-XBX (where x = 5, 10, 17, 20, 22, 25, 37.5 and 50 at. %) and a bulk metallic glass (BMG) composition (Fe60Co8Zr10Mo5W2B15) were subjected to mechanical alloying in a SPEX 8000 mixer mill. X-ray diffraction technique was employed to study the phase evolution, crystallite size, lattice strain and also to determine the crystal structure(s) of the phases. Depending on the milling time, formation of supersaturated solid solutions, …

High Gain / Broadband Oxide Glasses For Next Generation Raman Amplifiers, Clara Rivero

Electronic Theses and Dissertations

Interest in Raman amplification has undergone a revival due to the rapidly increasing bandwidth requirements for communications transmission, both for long haul and local area networks, and recent developments in the telecom fiber industry and diode laser technology. In contrast to rare earth doped fiber amplifiers, for which the range of wavelengths is fixed and limited, Raman gain bandwidths are larger and the operating wavelength is fixed only by the pump wavelength and the bandwidth of the Raman active medium. In this context, glasses are the material of choice for this application due to their relatively broad spectral response, and …

Coherence Properties Of Optical Near-Fields, Adela Apostol

Electronic Theses and Dissertations

Next generation photonics-based technologies will ultimately rely on novel materials and devices. For this purpose, phenomena at subwavelength scales are being studied to advance both fundamental knowledge and experimental capabilities. In this dissertation, concepts specific to near-field optics and experimental capabilities specific to near-field microscopy are used to investigate various aspects of the statistical properties of random electromagnetic fields in the vicinity of optically inhomogeneous media which emit or scatter radiation. The properties of such fields are being characterized within the frame of the coherence theory. While successful in describing the far-field properties of optical fields, the fundamental results of …

Liquid Crystal Materials And Tunable Devices For Optical Communications, Fang Du

Electronic Theses and Dissertations

In this dissertation, liquid crystal materials and devices are investigated in meeting the challenges for photonics and communications applications. The first part deals with polymer-stabilized liquid crystal (PSLC) materials and devices. Three polymer-stabilized liquid crystal systems are developed for optical communications. The second part reports the experimental investigation of a novel liquid-crystal-infiltrated photonic crystal fiber (PCF) and explores its applications in fiber-optic communications. The curing temperature is found to have significant effects on the PSLC performance. The electro-optic properties of nematic polymer network liquid crystal (PNLC) at different curing temperatures are investigated experimentally. At high curing temperature, a high contrast, …

Effect Of Microstructure And Alloying Elements On The Resistance Of Fastener Grade Steels To Hydrogen Assisted Cracking , Nicholas E. Nanninga

Dissertations, Master's Theses and Master's Reports - Open

Fastener grade steels with varying alloy contents and heat treatments were employed to measure changes in resistance to hydrogen assisted cracking. The testing procedure compared notched tension specimens fractured in air to threshold stress values obtained during hydrogen charging, utilizing a rising step load procedure. Bainitic structures improved resistance by 10-20% compared to tempered martensite structures. Dual phase steels with a tempered martensite matrix and 20% ferrite were more susceptible and notch sensitive. High strength, fully pearlitic structures showed an improvement in resistance. Carbon content, per se, had no effect on the resistance of steel to hydrogen assisted cracking. Chromium …

Control Algorithms For Large Scale Adaptive Optics, Piotr Piatrou

Dissertations, Master's Theses and Master's Reports - Open

In this dissertation, the problem of creating effective large scale Adaptive Optics (AO) systems control algorithms for the new generation of giant optical telescopes is addressed. The effectiveness of AO control algorithms is evaluated in several respects, such as computational complexity, compensation error rejection and robustness, i.e. reasonable insensitivity to the system imperfections. The results of this research are summarized as follows:

1. Robustness study of Sparse Minimum Variance Pseudo Open Loop Controller (POLC) for multi-conjugate adaptive optics (MCAO). The AO system model that accounts for various system errors has been developed and applied to check the stability and performance …

Corrugated Wood Composite Panels For Structural Decking, Wei Chiang Pang

Dissertations, Master's Theses and Master's Reports - Open

High flexural strength and stiffness can be achieved by forming a thin panel into a wave shape perpendicular to the bending direction. The use of corrugated shapes to gain flexural strength and stiffness is common in metal and reinforced plastic products. However, there is no commercial production of corrugated wood composite panels. This research focuses on the application of corrugated shapes to wood strand composite panels.

Beam theory, classical plate theory and finite element models were used to analyze the bending behavior of corrugated panels. The most promising shallow corrugated panel configuration was identified based on structural performance and compatibility …

Beneficial Reuse And Sustainability: The Fate Of Organic Compounds In The Land-Applied Waste, M. R. Overcash, Ronald C. Sims, J. L. Sims, K. C. Nieman

Biological Engineering Faculty Publications

Land application systems, also referred to as beneficial reuse systems, are engineered systems that have defined and permitted application areas based on site and waste characteristics to determine the land area size requirement. These terrestrial systems have orders of magnitude greater microbial capability and residence time to achieve decomposition and assimilation compared with aquatic systems. In this paper we focus on current information and information needs related to terrestrial fate pathways in land treatment systems. Attention is given to conventional organic chemicals as well as new estrogenic and pharmaceutical chemicals of commerce. Specific terrestrial fate pathways addressed include: decomposition, bound …

Establishing An Entertainment Engineering Curriculum, Robert F. Boehm, Joe Aldridge, Brackley Frayer

Electrical & Computer Engineering Faculty Research

A new, multidisciplinary program in Entertainment Engineering and Design is being established at the University of Nevada Las Vegas. The name of the program could be defined in a number of ways because few programs of this type exist and the field is so broad. Our emphasis is on the application of technology to enhance the entertainment value of live shows and rides. Steps being taken to establish this program are outlined, starting with an undergraduate minor and moving to an undergraduate major. The role of entertainment-based businesses in the development of this new program is also described.

Do Maps Guide The Way To Npd Success? Theoretical And Practical Aspects Of Knowledge Mapping In Product Development, Antonie J, Jetter

Engineering and Technology Management Faculty Publications and Presentations

New product development success largely depends on the ability to combine newly acquired information on customer demands and technological options with knowledge that exists within the company. Project organization and high employee turnover, however, make it difficult to be informed about what knowledge is available within the company and to access it successfully. Knowledge maps, a popular concept in present knowledge management, offer a possible solution by ?guiding the way to knowledge?. Their purpose, structure and content varies greatly, as does their ability to capture different aspects of knowledge. This paper investigates the theoretical basis of different types of knowledge …

Physically Based Multiscale-Viscoplastic Model For Metals And Steel Alloys: Theory And Computation, Farid H. Abed

LSU Doctoral Dissertations

The main requirement of large deformation problems such as high-speed machining, impact, and various primarily metal forming, is to develop constitutive relations which are widely applicable and capable of accounting for complex paths of deformation. Achieving such desirable goals for material like metals and steel alloys involves a comprehensive study of their microstructures and experimental observations under different loading conditions. In general, metal structures display a strong rate- and temperature-dependence when deformed non-uniformly into the inelastic range. This effect has important implications for an increasing number of applications in structural and engineering mechanics. The mechanical behavior of these applications cannot …

Low Dielectric Constant Fluorocarbon Films Containing Silicon By Plasma Enhanced Chemical Vapor Deposition, Yoonyoung Jin

LSU Doctoral Dissertations

Use of low relative dielectric constant (low-k) material as an interlayer dielectric is among important approaches to reduce the RC time delay in high performance ultra-large-scale integrated circuits. Copper metallization is another approach besides the use of low-k material, in reducing the RC delay time, because of its well-known characteristics of low resistivity and high electromigration resistance. Fluorocarbon films containing silicon (SiCF) have been developed in this work for low-k interlayer dielectric applications below 50 nm linewidth technology. The films were prepared by plasma enhanced chemical vapor deposition (PECVD) using gas precursors of tetrafluoromethane as the source of active species …

Chemical Vapor Deposition Of Thin Films For Ulsi Interconnect Metallization, Lidong Wang

LSU Doctoral Dissertations

We have studied the kinetics of copper chemical vapor deposition (CVD) for interconnect metallization using solution delivery of Cu(hfac)2 (Cu(II) hexafluoroacetyl-acetonate) dissolved in isopropanol. We observe a growth rate of 17.7 „b 1.5 nm/min at reference conditions of 300„aC substrate temperature, 0.025 Torr Cu(hfac)2 partial pressure, 1.6 Torr isopropanol (reducing agent), and 80 Torr H2 (carrier gas). The film resistivity approaches the bulk value of copper for film thickness greater than 100 nm. Reaction order experiments show first-order kinetics with respect to Cu(hfac)2 partial pressure and zero-order with respect to isopropanol. A series reaction mechanism including three kinetically significant steps …

Weak Factorizations, Fractions And Homotopies, Alexander Kurz, Jiří Rosický

Engineering Faculty Articles and Research

We show that the homotopy category can be assigned to any category equipped with a weak factorization system. A classical example of this construction is the stable category of modules. We discuss a connection with the open map approach to bisimulations proposed by Joyal, Nielsen and Winskel.

Incorporating The Impact Of Engineering Solutions On Society Into Technical Engineering Courses, Nicole Dejong-Okamoto, Jinny Rhee, Nikos J. Mourtos

Faculty Publications

In the era of market and workforce globalisation, engineers need a solid understanding of the impact that their products have locally, as well as globally. This is why the US Accreditation Board for Engineering and Technology (ABET) recently put a new spin on this requirement in engineering education. Specifically, outcome 3h of Engineering Criteria 2000 states that engineering graduates must have the broad education to understand the impact of engineering solutions in a global/ societal context. This outcome may be one of the most difficult to achieve, since it requires not only a strong technical understanding, but also an informed …