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X-Ray Absorption Spectroscopy Applied To Mixed-Metal Iron-Based Fischer-Tropsch Catalysts, Andrew Allen Campos 2010 Louisiana State University and Agricultural and Mechanical College

X-Ray Absorption Spectroscopy Applied To Mixed-Metal Iron-Based Fischer-Tropsch Catalysts, Andrew Allen Campos

LSU Doctoral Dissertations

Synthetic fuels derived from methane, coal or biomass are essential in addressing future transportation fuel demands which are expected to exceed petroleum-derived capacities. The Fischer-Tropsch synthesis (FTS) is the most studied technique for the conversion of coal or biomass-derived syngas into transportation fuels. Fe-based catalysts are typically used for the FTS of biomass and/or coal-derived syngas due to: the relatively low cost of iron, water-gas shift activity, and low methane selectivity at industrial FTS conditions. Fe/Cu/SiO2 Fischer-Tropsch catalysts promoted with Cr, Mn, Mo, W, or Zr were studied in-situ, using Fe K-edge TPR XANES (temperature programmed reduction ...


Electrodeposited Cu-Based Catalysts For Alcohols From Co Hydrogenation And Electrodeposition Of Cuniw/Cuni Multilayered Alloys, Mayank Gupta 2010 Louisiana State University and Agricultural and Mechanical College

Electrodeposited Cu-Based Catalysts For Alcohols From Co Hydrogenation And Electrodeposition Of Cuniw/Cuni Multilayered Alloys, Mayank Gupta

LSU Doctoral Dissertations

Ethanol and higher alcohols can be used as a fuel or fuel additive in gasoline engines as well as a hydrogen carrier. One of the promising methods to synthesize these alcohols is based on thermochemical conversion of CO and H2 (CO hydrogenation). Conventional catalysts used for the conversion CO and H2 (syngas) to ethanol typically give yields less than 20% with the balance resulting mostly in the formation of the thermodynamically favored products CH4 and CO2. New catalysts with compositions designed to kinetically favor the formation of ethanol and higher alcohols are needed. Electrodeposition of nanowires offers a means to ...


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 ...


Dynamic Model Of Ecological Factors Impacting The Gulf Of Mexico Dead Zone, Jimmie Arnold Brumfield II 2010 Louisiana State University and Agricultural and Mechanical College

Dynamic Model Of Ecological Factors Impacting The Gulf Of Mexico Dead Zone, Jimmie Arnold Brumfield Ii

LSU Doctoral Dissertations

The industrial agriculture complex of the Mississippi River Drainage Basin has the positive effect of feeding more individuals with less land via the use of chemical nutrients, pesticides and drainage. The negative effects of the agricultural nutrient load are carried by the Mississippi River to the Gulf of Mexico. After the flood of 1927 the Flood Control Act of 1928 began changing the Mississippi River into a navigation and flood control project. While successful, the river was turned into a channel where nutrient input was discharged into the Gulf of Mexico. Nitrogen compounds discharged from the Mississippi are claimed to ...


Design Techniques To Improve Time Dependent Dielectric Breakdown Based Failure For Cmos Circuits, Emanuel S. Tarog 2010 California Polytechnic State University, San Luis Obispo

Design Techniques To Improve Time Dependent Dielectric Breakdown Based Failure For Cmos Circuits, Emanuel S. Tarog

Master's Theses and Project Reports

This project investigates the failure of various CMOS circuits as a result of Time Dependent Dielectric Breakdown (TDDB) and explores design techniques to increase the mean time to failure (MTTF) of large-scale circuits. Time Dependent Dielectric Breakdown is a phenomenon where the oxide underneath the gate degrades as a result of the electric field in the material. Currently, there are few well documented design techniques that can increase lifetime, but with a tool chain I created called the MTTF Analyzing Program, or MAP, I was able to test circuits under various conditions in order to identify weak links, discover relationships ...


Merlin.Net Automation Of External Reports Verification Process, Gabriel John Wettlaufer 2010 California Polytechnic State University, San Luis Obispo

Merlin.Net Automation Of External Reports Verification Process, Gabriel John Wettlaufer

Master's Theses and Project Reports

Merlin.net Patient Care Network is a St. Jude Medical product that is used for remote patient management. The basic concept of Merlin.net is to allow the physician to view patient device follow-up information as well as general patient and device information on a web application. The Merlin.net system also interfaces with the patient and will send them notification if they miss a follow-up. All device information will be collected automatically while the patient is sleeping. This information is sent through a telephone line to a Merlin.net server to process a report package and display the collected ...


Effect Of Phosphorus On Cleavage Fracture In Κ-Carbide, N. I. Medvedeva, Ryan A. Howell, David C. Van Aken, Julia E. Medvedeva 2010 Missouri University of Science and Technology

Effect Of Phosphorus On Cleavage Fracture In Κ-Carbide, N. I. Medvedeva, Ryan A. Howell, David C. Van Aken, Julia E. Medvedeva

Materials Science and Engineering Faculty Research & Creative Works

To understand the origin of cleavage fracture which dominates in Fe(Mn)-Al-C alloys at a high phosphorus concentration, we performed first-principles study of the phosphorus effect on ideal cleavage energy and critical stress in κ-carbide, Fe3 AlC, a precipitate in the austenitic alloys. We find that phosphorus has higher solubility in Fe3 AlC than in γ-Fe and sharply reduces the cleavage characteristics of κ-carbide. We show that strong anisotropy of the Fe-P bonds in Fe3 (Al,P) C under tensile stress, leads to the appearance of large structural voids and may facilitate crack nucleation.


Task Analysis, Modeling, And Automatic Identification Of Elemental Tasks In Robot-Assisted Laparoscopic Surgery, Lavie Pinchas Golenberg 2010 Wayne State University

Task Analysis, Modeling, And Automatic Identification Of Elemental Tasks In Robot-Assisted Laparoscopic Surgery, Lavie Pinchas Golenberg

Wayne State University Dissertations

Robotic microsurgery provides many advantages for surgical operations, including tremor filtration, an increase in dexterity, and smaller incisions. There is a growing need for a task analyses on robotic laparoscopic operations to understand better the tasks involved in robotic microsurgery cases. A few research groups have conducted task observations to help systems automatically identify surgeon skill based on task execution. Their gesture analyses, however, lacked depth and their class libraries were composed of ambiguous groupings of gestures that did not share contextual similarities.

A Hierarchical Task Analysis was performed on a four-throw suturing task using a robotic microsurgical platform. Three ...


Quantification Of Vascular Parametric Indices Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging, Areen Khaled Al.bashir 2010 Wayne State University

Quantification Of Vascular Parametric Indices Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging, Areen Khaled Al.Bashir

Wayne State University Dissertations

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a non-invasive method used to evaluate the biological activity in early clinical trials of novel drugs targeting the tumor vasculature using gadolinium-DTPA (Gd) as a contrast agent. However, it has some limitations, such as reproducibility, data acquisition times, the presence of noise, extracting contrast concentration, estimating T1 relaxation and estimating pharmacokinetic parameters.

In this work, a new approach to used fixed T1(0) which provides more reproducible DCE results has been introduced. Using this new algorithm to quantify the vascular changes in DCE-MRI, a pre-clinical renal cell carcinoma (RCC) tumor model was used ...


Examination Of Factors Affecting The Frequency, Response Time, And Clearance Time Of Incidents On Freeways, Indrajit Ghosh 2010 Wayne State University

Examination Of Factors Affecting The Frequency, Response Time, And Clearance Time Of Incidents On Freeways, Indrajit Ghosh

Wayne State University Dissertations

Traffic incidents are the primary cause of non-recurrent congestion in urban areas, resulting in reductions in roadway capacity and significant safety hazards to other motorists, as well as first responders. Many communities have initiated incident management programs that detect and respond to incidents and restore freeways to full capacity by clearing the incident scene as soon as possible. In the Detroit metro area, the Michigan Department of Transportation (MDOT) operates a Freeway Courtesy Patrol (FCP) program as part of its larger freeway incident management program from the Michigan Intelligent Transportation Systems (MITS) Center in downtown Detroit. The MITS Center maintains ...


Unified Role Assignment Framework For Wireless Sensor Networks, Manish Mahendra Kumar Kochhal 2010 Wayne State University

Unified Role Assignment Framework For Wireless Sensor Networks, Manish Mahendra Kumar Kochhal

Wayne State University Dissertations

Wireless sensor networks are made possible by the continuing improvements in embedded sensor, VLSI, and wireless radio technologies. Currently, one of the important challenges in sensor networks is the design of a systematic network management framework that allows localized and collaborative resource control uniformly across all application services such as sensing, monitoring, tracking, data aggregation, and routing.

The research in wireless sensor networks is currently oriented toward a cross-layer network abstraction that supports appropriate fine or course grained resource controls for energy efficiency. In that regard, we have designed a unified role-based service paradigm for wireless sensor networks. We pursue ...


Flexible Pavement Rut Depth Modeling For Different Climate Zones, Asmaiel Kodan Naiel 2010 Wayne State University

Flexible Pavement Rut Depth Modeling For Different Climate Zones, Asmaiel Kodan Naiel

Wayne State University Dissertations

Pavement rutting is one of the most important types of pavement distress that affect road safety and ride quality. Therefore, the primary objective of this study was to develop pavement rutting empirical models for different climate zones to predict pavement rutting on granular base based on LTPP data. Flexible pavements with granular base course were considered for this study. These models lead to better understanding of rutting phenomena and the factors that may have affect in pavement rutting. In addition, these models will help state and local transportation agencies make accurate decisions for maintenance, rehabilitation and reconstruction of pavement.

To ...


The Fourier Spectrum Element Method For Vibration And Power Flow Analysis Of Complex Dynamic Systems, Hongan Xu 2010 Wayne State University

The Fourier Spectrum Element Method For Vibration And Power Flow Analysis Of Complex Dynamic Systems, Hongan Xu

Wayne State University Dissertations

A general numerical method, the so-called Fourier-Space Element Method (FSEM), is proposed for the vibration and power flow analyses of complex built-up structures. In a FSEM model, a complex structure is considered as a number of interconnected basic structural elements such as beams and plates. The essence of this method is to invariably express each of displacement functions as an improved Fourier series which consists of a standard Fourier cosine series plus several supplementary series/functions used to ensure and improve the uniform convergence of the series representation. Thus, the series expansions of the displacement functions and their relevant derivatives ...


Filter Scheduling Function Model In Internet Server: Resource Configuration, Performance Evaluation And Optimal Scheduling, Minghua Xu 2010 Wayne State University

Filter Scheduling Function Model In Internet Server: Resource Configuration, Performance Evaluation And Optimal Scheduling, Minghua Xu

Wayne State University Dissertations

ABSTRACT

FILTER SCHEDULING FUNCTION MODEL IN INTERNET SERVER:

RESOURCE CONFIGURATION, PERFORMANCE EVALUATION AND

OPTIMAL SCHEDULING

by

MINGHUA XU

August 2010

Advisor: Dr. Cheng-Zhong Xu

Major: Computer Engineering

Degree: Doctor of Philosophy

Internet traffic often exhibits a structure with rich high-order statistical properties like selfsimilarity

and long-range dependency (LRD). This greatly complicates the problem of

server performance modeling and optimization. On the other hand, popularity of Internet

has created numerous client-server or peer-to-peer applications, with most of them,

such as online payment, purchasing, trading, searching, publishing and media streaming,

being timing sensitive and/or financially critical. The scheduling policy in Internet ...


Molecular Modeling Of Energetic Materials And Chemical Warfare Agents, Nandhini Sokkalingam 2010 Wayne State University

Molecular Modeling Of Energetic Materials And Chemical Warfare Agents, Nandhini Sokkalingam

Wayne State University Dissertations

Contamination of military sites by energetic materials and chemical warfare agents is a growing problem. To avoid health hazards associated with these compounds, it is necessary to decontaminate or remediate the contaminated sites. Effective decontamination requires knowledge of environmental fate of contaminants and the appropriate remediation methodologies. While the fate of chemical warfare agents are well studied, the impact of certain energetic materials in the environment is relatively unknown. So the current focus is determining environmental fate of Insensitive Munitions (IM) which are energetic materials that have low shock sensitivity and high thermal stability and developing detection schemes for identifying ...


Imaging The Vasculature With Susceptibility Weighted Imaging: Applications And Analysis, Samuel Barnes 2010 Wayne State University

Imaging The Vasculature With Susceptibility Weighted Imaging: Applications And Analysis, Samuel Barnes

Wayne State University Dissertations

Modern magnetic resonance imaging sequences allow detailed non-invasive imaging of both the arteries and veins. This work is divided into four sections that examine different applications and analysis of these sequences.

Susceptibility weighted imaging (SWI) typically generates excellent negative venous contrast. Techniques to generate positive arterial contrast in SWI images without degrading the venous contrast with a single echo are examined. By using high isotropic resolution and high readout bandwidth flow losses can be minimized (generating good arterial contrast) even at the long echo times required for good venous contrast. A downsampling filter is then used to restore lost venous ...


Accelerated Lattice Boltzmann Method For Colloidal Suspensions Rheology And Interface Morphology, Hassan Farhat 2010 Wayne State University

Accelerated Lattice Boltzmann Method For Colloidal Suspensions Rheology And Interface Morphology, Hassan Farhat

Wayne State University Dissertations

ABSTRACT

ACCELERATED LATTICE BOLTZMANN MODEL FOR COLLOIDAL SUSPENSIONS RHEOLOGY AND INTERFACE MORPHOLOGY

by

HASSAN FARHAT

July 2010

Advisor: Dr. Singh Trilochan

Co-Advisor: Dr. Joon Sang Lee

Major: Mechanical Engineering

Degree: Doctor of Philosophy

Colloids are ubiquitous in the food, medical, cosmetic, polymer, water purification and pharmaceutical industries. Colloids thermal, mechanical and storage properties are highly dependent on their interface morphology and their rheological behavior.

Numerical methods provide a cheap and reliable virtual laboratory for the study of colloids. However efficiency is a major concern to address when using numerical methods for practical applications.

This work introduces the main building-blocks for ...


Robust Observers And Controllers For Marine Surface Vessels Undergoing Maneuvering And Course-Keeping Tasks, Nassim Khaled 2010 Wayne State University

Robust Observers And Controllers For Marine Surface Vessels Undergoing Maneuvering And Course-Keeping Tasks, Nassim Khaled

Wayne State University Dissertations

The dynamic behavior of marine surface vessels is highly nonlinear. Moreover, it is significantly influenced by environmental disturbances induced by winds, random sea waves and currents. To yield a desired response of the ship, the guidance and control system of the ship should be robust to both modeling imprecision and significant environmental disturbances.

The focus of the current work is threefold. First, a six degree-of-freedom nonlinear model for a marine surface vessel is developed. It accounts for the coriolis and centripetal acceleration terms, added mass and wave damping terms, wave excitation forces, so-called "memory" effect terms, nonlinear restoring forces, wind ...


Single Channel Vocal Separation Using Median Filtering And Factorisation Techniques, Derry Fitzgerald, Mikel Gainza 2010 Technological University Dublin

Single Channel Vocal Separation Using Median Filtering And Factorisation Techniques, Derry Fitzgerald, Mikel Gainza

Articles

This paper deals with the problem of the extraction of vocals from single channel audio signals containing both vocals and other instruments, including both pitched instruments and percussion instruments. A novel median filtering-based approach for the extraction of vocal tracks is described, which is simple and efficient to implement. Further improvements in separation quality are then obtained by the application of tensor factorisation techniques to further extract residual instruments from the vocal mix. Finally, a novel use of non-negative partial matrix cofactorisation is demonstrated as a means of further improving separation quality. Here the original single channel mixture is partially ...


Evaluating Sensorineural Hearing Loss With An Auditory Nerve Model Using A Mean Structural Similarity Measure, Andrew Hines, Naomi Harte 2010 Technological University Dublin

Evaluating Sensorineural Hearing Loss With An Auditory Nerve Model Using A Mean Structural Similarity Measure, Andrew Hines, Naomi Harte

Conference papers

Hearing loss research has traditionally been based on perceptual criteria, speech intelligibility and threshold levels. The development of computational models of the auditory-periphery has allowed experimentation via simulation to provide quantitative, repeatable results at a more granular level than would be practical with clinical research on human subjects. This work seeks to create an objective measure to automate this inspection process and ranks hearing losses based on auditory-nerve discharge patterns. A systematic way of assessing phonemic degradation using the outputs of an auditory nerve model for a range of sensorineural hearing losses would aid in rapid prototyping development of speech-processing ...


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