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Numerical Solution Of Flow Resistance In Outflow Pathway And Intravitreal Drug Delivery In Vitrectomised Eyes, Jyoti Gururaj Kathawate

LSU Master's Theses

In this study, numerical computations of the ocular fluid dynamics in a human eye are presented with a perspective of understanding the mechanisms of increased flow resistance. In the present study, the TM is represented as a multilayered-graded porous structure with specific pore size and void fraction. The flow patterns and pressure distribution in anterior chamber are analyzed to delineate key flow mechanism; the shear stresses on the lens, iris and IW of SC are also examined to locate the maximum values. Inside the human eye, the largest pressure drop occurs across JCT and IW of SC. The highest pressure …

Delineating Hurricane Vulnerable Populations In Orleans Parish, Louisiana, Stephanie Pedro

LSU Master's Theses

Since settlement first began, equality issues between different social classes have been evident in the location of where residents settled in New Orleans. This research seeks to answer the question: What socioeconomic indicators are prevalent in the areas most-at-risk to flooding which could inhabit populations least able to evacuate? I will use Census 2000 block group data from the socioeconomic sample data (SF3) collected in 2000, along with other economic and GIS data from the New Orleans region to statistically represent the distribution of risk by selecting indicators predicted to be in flood zones from a classification tree analysis. Then, …

Two-Dimensional Penalized Signal Regression For Hand Written Digit Recognition, Qing Tang

LSU Master's Theses

Many attempts have been made to achieve successful recognition of handwritten digits. We report our results of using statistical method on handwritten digit recognition. A digitized handwritten numeral can be represented by an image with grayscales. The image includes features that are mapped into two-dimensional space with row and column coordinates. Based on this structure, two-dimensional penalized signal logistic regression (PSR) is applied to the recognition of handwritten digits. The data set is taken from the USPS zip code database that contains 7219 training images and 2007 test images. All the images have been deslanted and normalized into 16 x …

Comparative Study Of Axial Flux Permanent Magnet Brushless Dc Motor Operating With The Winding Connected In Single-Phase And Two-Phase System, Sunil Kumar Challa

LSU Master's Theses

The object of the study is a double-sided axial flux permanent magnet brushless dc (AFPM BLDC) motor with salient pole stator. Its winding can be connected either in single-phase or in two-phase system, which results in different operation of the motor.

The objective of the thesis is to analyze and compare the performances of the AFPM BLDC motor with single-phase winding and two-phase winding. To study the motor operation, a mathematical dynamic model has been proposed for each of the motor with different winding, which became the basis for simulations that were performed using MATLAB/SIMULINK software package.

The calculations were …

Computer-Aided Diagnostic Systems For Digital Mammograms, Nicholas Jabari Lee

LSU Master's Theses

A computer-aided diagnostic (CAD) system that uses a unique shape-based classification scheme, the Ellipse-Closed Curve Fitting (ECCF) algorithm, is developed for digital mammogram image analysis. The system is developed to work as a post-processing extension to a previously developed CAD system that locates and segments mass lesions, or tumors, found in digital mammograms into separate images. The ECCF system is implemented in the MATLAB mathematical scripting language and is thus capable of running on multiple platforms. The ECCF algorithm detects edges in tumor images and casts them into closed curve functions. Parameters for an ellipse of best fit for a …

Swamp Tours In Louisiana Post Hurricane Katrina And Hurricane Rita, Dawn Schaffer

LSU Master's Theses

Hurricanes Katrina and Rita made landfall in southern Louisiana during August and September 2005, respectively. Prior to these storms swamp tours were a popular nature-based tourism experience that entertained visitors while teaching them about local flora, fauna, and culture. The number of swamp tour businesses in the state was slowly increasing. The purpose of this study was to determine how many swamp tours were operating after the hurricanes, what type of damage they sustained, and how they repaired their businesses. Differences between those tours that remained open after the hurricanes and those that closed were also examined. A 3-phase mail …

Modeling The Effects Of Endocrine Disrupting Chemicals On Atlantic Croaker: Understanding Biomarkers And Predicting Population Responses, Cheryl Anne Murphy

LSU Doctoral Dissertations

A number of environmental stressors have been shown to interfere with reproductive and behavioral processes of fish by interfering with endocrine function. Most biomarkers of endocrine disturbance tend to be static measurements from dynamic systems making them difficult to evaluate within the context of an individual, or subtle effects that do not relate well to endpoints of ecological significance. I present an approach that uses a series of models, based on Atlantic croaker, to extrapolate laboratory results to indicators of individual and population health. First, I created a physiologically based model that simulates vitellogenesis in a female fish. The model …

An Analysis Of Public Transit Accessibility Using The Distance Constrained P-Median Problem Approach: Bus Stop Consolidation For The Capital Area Transit System Of East Baton Rouge Parish, Louisiana, Sainath Challuri

LSU Master's Theses

Over the past four decades public transit usage has declined in the United States. Transit Planners have suggested that public transit usage should be encouraged because public transit can account for greater travel demand than cars and would reduce pollution, traffic congestion and energy consumption. Easy access to public transit stops is important because research has found that usage of public transit and access are inversely proportional. U.S. transit systems have a relatively high density of stops resulting in high accessibility levels at the cost of increased travel times. In this study access distance to transit stops and bus stop …

The Antikythera Youth In Its Context, Elisabeth Myers

LSU Master's Theses

The bronze statue known as the Antikythera Youth was discovered in numerous fragments by sponge divers in 1900 with the remains of an ancient shipwreck near the small island of Antikythera, south of the Peloponnesus of Greece. The divers, together with the Greek government, recovered the statue and the rest of the ship’s cargo. The statue was then taken to the National Archaeological Museum, where it was assembled and restored. In the 1950s, the statue underwent a second restoration. This thesis examines the condition of the statue after the restorations and the technique by which it was made. It also …

Performance Of Torus-Type Brushless Dc Motor With Winding Connected In Two And Three-Phase System, Dinakar Choppa

LSU Master's Theses

A torus-type permanent magnet brushless DC motor is the object of this thesis. The motor can operate with the winding connected either in two - phase or three - phase system. A comparative study of performance of the motor operating in these two systems is the objective of the thesis. To analyze the motor performance, the dynamic models of the motors operating with two - phase and three - phase motors have been proposed. The simulation of motor operation was carried out using the MATLAB/SIMULINK software package. A study of motors operation in steady state conditions has been done by …

Schottky Field Effect Transistors And Schottky Cmos Circuitry, Reinaldo Vega

Theses

It was the primary goal (and result) of the presented work to empirically demonstrate CMOS operation (i.e., inverter transfer characteristics) using metallic/Schottky source/drain MOSFETs (SFETs - Schottky Field Effect Transistors) fabricated on silicon-on-insulator (SOI) substrates - a first-ever in the history of SFET research. Due to its candidacy for present and future CMOS technology, many different research groups have explored different SFET architectures in an effort to maximize performance. In the presented work, an architecture known as a "bulk switching" SFET was fabricated using an implant-to-silicide (ITS) technique, which facilitates a high degree of Schottky barrier lowering and therefore an …

Red And Black Tides: Quantitative Analysis Of Water-Leaving Radiance And Perceived Color For Phytoplankton, Colored Dissolved Organic Matter, And Suspended Sediments, Heidi M. Dierssen, Raphael M. Kudela, John P. Ryan, Richard C. Zimmerman

OES Faculty Publications

Using field measurements and quantitative modeling, we demonstrate that red coloration of the sea surface is not associated with any particular group of phytoplankton and is strongly dependent on the physiology of the human visual system. Red or brown surface waters can be produced by high concentrations of most types of algae, colored dissolved organic matter, or suspended sediment. Even though light reflected by red tides commonly peaks in the yellow spectral region (570–580 nm), human color perception requires consideration of the entire spectrum of light relative to receptors within the human eye. The color shift from green to red …

The Convergence Of V-Cycle Multigrid Algorithms For Axisymmetric Laplace And Maxwell Equations, Jay Gopalakrishnan, Joseph E. Pasciak

Mathematics and Statistics Faculty Publications and Presentations

We investigate some simple finite element discretizations for the axisymmetric Laplace equation and the azimuthal component of the axisymmetric Maxwell equations as well as multigrid algorithms for these discretizations. Our analysis is targeted at simple model problems and our main result is that the standard V-cycle with point smoothing converges at a rate independent of the number of unknowns. This is contrary to suggestions in the existing literature that line relaxations and semicoarsening are needed in multigrid algorithms to overcome difficulties caused by the singularities in the axisymmetric Maxwell problems. Our multigrid analysis proceeds by applying the well known regularity …

Oxygen Demand Trends, Land Cover Change, And Water Quality Management For An Urbanizing Oregon Watershed, Michael Karl Boeder

Dissertations and Theses

In-stream aquatic habitat depends on adequate levels of dissolved oxygen. Human alteration of the landscape has an extensive influence on the biogeochemical processes that drive oxygen cycling in streams. Historic datasets allow researchers to track trends in chemical parameters concomitant with urbanization, while land cover change analysis allows researchers to identify linkages between water quality trends and landscape change.

Using the Seasonal Kendall's test, I examined water quality trends in oxygen demand variables during the mid-1990s to 2003, for twelve sites in the Rock Creek sub-watershed of the Tualatin River, northwest Oregon. Significant trends occurred in each parameter. Dissolved oxygen …

Breeding Waterbird Use Of Rice Fields In Southwestern Louisiana, Sergio Pierluissi

LSU Master's Theses

Rice fields are agricultural wetlands concentrated in several areas in the U.S., including southwestern Louisiana. Rice fields are flooded for much of the year and support thick emergent vegetation, potentially providing high-quality habitat for several species of breeding waterbirds. The objectives of this study were to (1) determine relative nest density, nest success, and habitat associations of breeding waterbirds in southwestern Louisiana rice fields and (2) determine the effectiveness of callback surveys as a monitoring tool. In the summers of 2004 and 2005, marsh bird surveys and nest searches were conducted in Cameron, Jefferson Davis, Vermilion, and Acadia Parishes in …

Effects Of Insectivorous Birds On Tree Growth In The Maurepas Swamp, David M. Fox

LSU Master's Theses

Coastal forests in Louisiana are in decline due to natural and human caused changes in the hydrology of the region. Baldcypress and water tupelo trees have been further stressed by caterpillar herbivory in recent decades. Regeneration of water tupelo is crucial for cavity creation for nesting habitat for secondary cavity nesting bird populations. Insectivorous birds have been shown to decrease insect-caused leaf damage on trees in other ecosystems. Two experiments examining effects of insectivorous birds on tree growth were conducted in degraded areas of the Maurepas Swamp in southeastern Louisiana. In the first experiment, nest boxes were added to study …

A New Method To Determine Radiative Properties Of Rough Solid Surfaces, Raghu Nandan Mutukulla

LSU Master's Theses

The radiative properties of the rough surfaces are important both from fundamental and practical standpoint. Thus, there is a need to determine the effect of roughness on radiative properties of materials accurately, as these properties effect the performance of electronic devices, communication devices, optical sensors, and furnaces, amongst others. The effects of roughness are assessed by measuring the reflection coefficients from the carbon rod surfaces and steel 1086 samples over the range of angles 25 to 75 in the visible range and near infrared region. Different levels of roughness are induced on the surfaces by utilizing different grid size sand-paper …

Fundamentals For Student Success In The Middle Grades, Mike Muir, Vincent A. Anfara Jr., P. Gayle Andrews, Micki M. Caskey, Steven B. Mertens, David Hough

Curriculum and Instruction Faculty Publications and Presentations

Determining how to provide the best education possible for young adolescents begins with the answers to three essential questions: Who are young adolescents? What do we know about them, their abilities, interests and strengths? Based on what we know about young adolescents, what should schools do to provide a quality education for each and every student? And finally, is there evidence that these recommended practices improve student achievement? How do we know programs and practices designed specifically with young adolescents in mind make a difference? To answer these questions, we will first outline some of the developmental characteristics of young …

Thermal Management Of Micro Gas Chromatographs, Chetan Ramesh

LSU Master's Theses

Gas chromatography is an analytical technique for separating and analyzing individual components in a gas mixture. Applications of gas chromatographs (GCs) include chemical analysis, environmental maintenance, green house gases monitoring, and forensic analysis when used in conjunction with mass spectrometry. There has been a tremendous interest in miniaturization of gas chromatograph systems because of significantly reduced size, portability, fast response times, low power consumption and low cost. Isothermal analysis is a chromatographic analysis at one column temperature. In temperature programming, a linear increase of column temperature with time is used during the course of the analysis. Temperature programming facilitates separation …

Effects Of Terraces On Submerged Aquatic Vegetation In Shallow Marsh Ponds In Coastal Southwest Louisiana, Christopher Dean Cannaday

LSU Master's Theses

The wetlands of coastal Louisiana are disappearing at a rate of 65 to 80 km²yr^-1. Most of the loss is the conversion of emergent marsh to shallow marsh ponds. Terracing is one restoration technique that has been used frequently in recent years. Terraces are small intertidal ridges built in shallow marsh ponds to reduce wave action. It is assumed that this will slow erosion of adjacent emergent marsh and increase Submerged Aquatic Vegetation (SAV) production, a key habitat component for many marsh fauna. Yet both relevant previous studies failed to show that terraces increased SAV abundance. …

Verification Of Direct Brachytherapy Dosimetry For A Single Seed Implant, Jabari Robinson

LSU Master's Theses

A new technique using direct post-implant dosimetry, which does not depend explicitly on brachytherapy seed orientation or position, was explored for a prostate and a breast case. This technique, proposed by E Sajo and ML Williams (SW), uses trace amounts of positron emitters placed in the seed capsule and uses the positron emission tomography image in conjunction with a computed tomography image (PET-CT) to compute the therapeutic dose distribution in the patient. The SW technique could reduce errors in the post-implant dose computations associated with seed localization, seed shadowing and medium heterogeneity. Dose point kernels were obtained using Monte Carlo …

Investigation Of The Structure In Electrodeposited Nanostructured Co/Cu Alloys, Multilayers, And Cofe/Cu Multilayered Nanowires, Erick Jamal Lawson

LSU Master's Theses

Since the discovery of giant magnetoresistance (GMR) in electrodeposited nanostructured magnetic multilayers and multilayered nanowires, there has been interest throughout the scientific world in the fabrication and characterization of these materials. Magnetic multilayers in the form of thin films can be used as magnetoresistive sensors in the magnetic data storage industry. Arrays of nanowires have the potential for applications in perpendicular ultra-high density data storage and biosensors. Wire-shaped magnetic multilayered nanowires have been shown to exhibit GMR in the so called “current perpendicular-to plane” configuration (CPP-GMR). GMR of multilayers and multilayered nanowires have been investigated in several systems that include …

Tomotherapy For Post-Mastectomy Radiotherapy (Pmrt): Comparison With Conventional Electron Beam Technique, Michael Sissay Ashenafi

LSU Master's Theses

Purpose: TomoTherapy, capable of delivering intensity-modulated, image-guided radiotherapy with a helical fan-beam, multileaf-collimated beam and detector array mounted on a CT ring, is challenging the treatment techniques commonly used in today's radiotherapy clinic. The present works investigates the potential of using TomoTherapy in lieu of electron beams for treatment of the chest wall in post-mastectomy radiotherapy (PMRT). It is hypothesized that TomoTherapy can plan dose distributions for PMRT patients, that a pre-selected radiation oncologist judges to be equal to or better than that of a conventional plan treated with electron beams. Methods: A patient database of retrospective conventional PMRT treatment …

An Architecture For Adaptive Real Time Communication With Embedded Devices, Amol S. Patwardhan

LSU Master's Theses

The virtual testbed is designed to be a cost-effective rapid development environment as well as a teaching tool for embedded systems. Teaching and development of embedded systems otherwise requires dedicated real time operating systems and costly infrastructure for hardware simulation. Writing control software for embedded systems with such a setup takes prolonged development cycles. Moreover, actual hardware may get damaged while writing the control software. On the contrary, in a virtual testbed environment, a simulator running on the host machine is used instead of the actual hardware, which then interacts with an embedded processor through serial communication. This hardware-in-the-loop setup …

Image-Based Nanocrystallography With Online Database Support, Peter Moeck, Ján Zahornadsky, Boris Dusek

Physics Faculty Publications and Presentations

The crystallographic phase and morphology of many materials change with the crystal size so that new needs arise to determine the crystallography of nanocrystals. Direct space high-resolution phase-contrast transmission electron microscopy (HRTEM) and atomic resolution scanning TEM (STEM) when combined with tools for image-based nanocrystallography in two (2D) and three (3D) dimensions possess the capacity to meet these needs. After a concise discussion of lattice-fringe visibility spheres and maps, this paper discusses lattice-fringe fingerprinting in 2D and tilt protocol applications. On-line database developments at Portland State University (PSU) that support image-based nanocrystallography are also mentioned.

Lattice Fringe Fingerprinting In Two Dimensions With Database Support, Peter Moeck, B. Seipel, R. Bjorge, P. Fraundorf

Physics Faculty Publications and Presentations

A brief introduction to lattice fringe fingerprinting in two dimensions (2D) with database support is given. The method is employed for the identification of the crystal phase of a small ensemble of nanocrystals. The enhanced viability of this method in aberration-corrected transmission electron microscopes (TEMs) and scanning TEMs (STEMs) is also illustrated.

A New Color-Magnitude Diagram For Palomar 11, Matthew S. Lewis, W. M. Liu, N. E. Q. Paust, Brian Chaboyer

Dartmouth Scholarship

We present new photometry for the Galactic thick-disk globular cluster Palomar 11 extending well past the main-sequence turnoff in the V and I bands. This photometry shows noticeable, but depleted, red giant and subgiant branches. The difference in magnitude between the red horizontal branch (red clump) and the subgiant branch is used to determine that Palomar 11 has an age of 10.4 ± 0.5 Gyr. The red clump is used to derive a distance d_⊙ = 14.3 ± 0.4 kpc and a mean cluster reddening of E(V - I) = 0.40 ± 0.03. There is differential …

Ubvi Ccd Photometry Of The Old Open Cluster Berkeley 17, Zosia A. C. Krusberg, Brian Chaboyer

Dartmouth Scholarship

Photometric UBVI CCD photometry is presented for NGC 188 and Berkeley 17. Color-magnitude diagrams (CMDs) are constructed and reach well past the main-sequence turnoff for both clusters. Cluster ages are determined by means of isochrone fitting to the cluster CMDs. These fits are constrained to agree with spectroscopic metallicity and reddening estimates. Cluster ages are determined to be 7.0 ± 0.5 Gyr for NGC 188 and 10.0 ± 1.0 Gyr for Berkeley 17, where the errors refer to uncertainties in the relative age determinations. These ages are compared to the ages of relatively metal-rich inner halo/thick-disk globular clusters and other …

Periodic Atlas Of The Metroscape: The Geography Of Water, Vivek Shandas, Alton Straub, Yongxia Kou

Institute for Sustainable Solutions Publications and Presentations

Describes the geography of water in the Portland, Oregon metropolitan area: groundwater, rivers, irrigation, water supply, and sewer lines.

Mathematical Model Of Arsenic Adsorption In A Modified Zeolite / Microfiltration System, Miles B. Beamguard

USF Tampa Graduate Theses and Dissertations

Carcinogenic health concerns over arsenic in drinking water caused the USEPA to reduce the maximum contaminant level (MCL) from 50 to 10 ppb, effective on January 23, 2006. This has forced many smaller utilities into expensive treatment or discontinuation of water distribution. Researchers throughout the world are working to develop an inexpensive method for arsenic removal to meet this MCL. Aluminum silicates, or zeolites, are naturally occurring ionic sorbents. Modification of a zeolite may enhance adsorption capacities and ion selectivity. This research investigates the arsenic adsorption capacities of a modified Chabazite. This adsorption, coupled with a hollow fiber, microfiltration membrane …