Digital Commons Network^™

Accelerating Ray Casting Using Culling Techniques To Optimize K-D Trees, Anh Viet Nguyen

Master's Theses

Ray tracing is a graphical technique that provides realistic simulation of light sources and complex lighting effects within three-dimensional scenes, but it is a time-consuming process that requires a tremendous amount of compute power. In order to reduce the number of calculations required to render an image, many different algorithms and techniques have been developed. One such development is the use of tree-like data structures to partition space for quick traversal when finding intersection points between rays and primitives. Even with this technique, ray-primitive intersection for large datasets is still the bottleneck for ray tracing.

This thesis proposes the use …

The Effect Of A Low-Velocity Impact On The Flexural Strength And Dynamic Response Of Composite Sandwiches With Damage Arrestment Devices, Kodi A. Rider

Master's Theses

Impact strength is one of the most important structural properties for a designer to consider, but is often the most difficult to quantify or measure. A constant concern in the field of composites is the effect of foreign object impact damage because it is often undetectable by visual inspection. An impact can create interlaminar damage that often results in severe reductions in strength and instability of the structure. The main objective of this study is to determine the effectiveness of a damage arrestment device (DAD) on the mechanical behavior of composite sandwiches, following a low-velocity impact. A 7.56-lb_f crosshead …

An Experimental Investigation Of A Goldschmied Propulsor, Joshua Roepke

Master's Theses

A wind tunnel investigation of an axisymmetric bluff body, known as a Goldschmied propulsor, was completed. This model conceptually combines boundary layer control and boundary layer ingestion into a single complementary system that is intended to use energy to reduce the axial force on the body by eliminating separation and increasing the pressure recovery aft of the body’s maximum thickness. The goal of the current project was to design, fabricate, and fully document the performance of a wind tunnel model incorporating the Goldschmied propulsor concept and complete an examination of its aerodynamic performance. The investigation took place at California Polytechnic …

Phase Speciation Of Carbohydrates And Dioxins In Rivers And Coastal Waters In The Northern Gulf Of Mexico, Kusumica Mitra

Master's Theses

Dissolved carbohydrates (d-CHO), including monosaccharide (MCHO) and polysaccharides (PCHO), and particulate carbohydrates (p-CHO) are major components of natural organic matter and play an important role in biogeochemical cycles of carbon and other trace elements in marine environments. This study aimed to examine the abundance and partitioning of CHO between dissolved and particulate phases and their seasonal variations in the Mississippi Sound/Bight and Lake Pontchartrain. Laboratory mixing experiments were also carried out to examine the behaviour of CHO species along a salinity gradient. The phase partitioning of dioxin among three different phases, i.e., colloidal organic matter, particulate organic matter and sediments, …

Determining The Trophic Role Of Gulf Menhaden (Brevoortia Patronus) Using Carbon And Nitrogen Stable Isotopes, Zachary Olsen

Master's Theses

Gulf menhaden (Brevoortia patronus) play multiple roles in the Gulf of Mexico coastal ecosystem as filter feeders and as an important food source for many recreationally and economically important finfish. Gulf menhaden also support a large commercial fishery, and little is known about the impact of fishing on the role of this species as a filter feeder in the food web. This study examines the spatial, temporal and ontogenetic dynamics of food selectivity and trophic role observed in Gulf menhaden. The most important dietary item for juvenile fish was found to be phytoplankton (75.7% dietary composition) while that of subadults …

Photo-Poetics: Photographic Narratives In The New Journalism, John David Hosemann Jr.

Master's Theses

Americans today have come to remember the unrest of the 1960s through the many shocking photographic images that emerged during that time. Images of assassinations, war, murders, and social upheaval have come to characterize this decade as particularly (perhaps perversely) photogenic. Further, these images have revealed the photographic medium as uniquely suited for confirming a violent reality that, at the time, seemed incomprehensible to an increasingly disillusioned public. In this discussion I seek to develop an understanding of photography as a theoretical process that can illuminate how we represent violent subject matter. In doing so, I apply these concepts to …

Panic Behind The Mask: The Spanish Influenza Epidemic Of 1918 In New Orleans, Sarah Theresa Savage

Master's Theses

As part of the most devastating influenza pandemic in modern history, the Spanish Influenza epidemic in New Orleans left the city emotionally and physically crippled as residents struggled to resume daily life after thousands succumbed to a bloody cough and painful death in October 1918. When New Orleans public health officials reacted to the explosion of Spanish Influenza cases on October 10, 1918, the virus had already traveled throughout the population. Unlike previous influenza outbreaks, the 1918 epidemic killed primarily young healthy adults, the backbones of the working force and families. In an attempt to quarantine the ill from the …

Effects Of Compost, Legume Cover Cropping And Vermicompost Extract Foliar Applications On Nutrition And Yield Of Washington Navel Oranges, William Payton Carling

Master's Theses

ABSTRACT

Effects of Compost, Legume Cover Cropping and Vermicompost Extract Foliar Applications on Nutrition and Yield of Washington Navel Oranges

William Payton Carling

An experiment was conducted to test the effects of four treatments on Washington navel orange (Citrus sinensis) trees in regards to nutrient content of the leaves and fruit, soil nutrient content and properties, and fruit yield. The four treatments included: compost (C) and vermicompost extract foliar (VEF) applications, legume cover cropping (LCC) and VEF applications, VEF applications, and a control. The treatments were implemented from February 2010 to April 2011 and sampling occurred in May …

Microcontroller Design Of A Bidirectional Three-Level Pulse Width Modulation Ac/Dc Converter For Vehicle-To-Grid Application, Joshua Jonn O. Aquino

Master's Theses

Bidirectional chargers provide plug-in electric vehicles (EV) the ability to not only transfer energy from the grid to the vehicle, but also transfer energy from the vehicle to the grid (V2G). The V2G mode allows power utility companies to offset peak power consumption thus allowing household consumers and industry corporations to save money on their electricity bills. This paper describes the design choices of bidirectional chargers and provides the implementation details for a Three-Level PWM AC-DC based charger. Although the three-level PWM AC-DC design requires a more complex controller than its counterparts, Matlab Simulink simulations show the design provides lower …

Improved Microalgal Biomass Harvesting Using Optimized Environmental Conditions And Bacterial Bioflocculants, Derek C. Manheim

Master's Theses

ABSTRACT

IMPROVED MICROALGAL BIOMASS HARVESTING USING OPTIMIZED ENVIRONMENTAL CONDITIONS AND BACTERIAL BIOFLOCCULANTS

DEREK CONTE MANHEIM

The cost and energy balance of microalgae biofuel production is sensitive to the algae harvesting method, among many other factors. Bioflocculation and settling of suspended microalgae cultures is a harvesting method with potentially low cost and energy input. However, bioflocculation (the spontaneous flocculation of algal cells without chemical addition) has not been a reliable process with cultures grown in ponds. To provide insights to help improve algae settling, factors affecting the settling of algae were investigated in the laboratory using pure cultures of two common …

A Cold War Episode: Detente And Us Relations With Pakistan During The 1971 South Asia Crisis, Ralph A. Becker

Master's Theses

The Cold War defined a state of conflict between the U.S., China, and the Soviet Union during the nuclear age that followed World War II. During the Cold War the United States practiced a foreign policy that was episodic in nature as the great nations recruited the developing countries of the Third World to carry on their ideological struggles. This policy meant that the U.S. would aggressively intervene during periods of war in developing countries in order to prevent the spread of communism. Yet, after the episode ended, the U.S. would quickly vacate the region and move on to other …

The Modern Sex Doll-Owner: A Descriptive Analysis, Sarah Hatheway Valverde

Master's Theses

Over the last fifteen years, the sex doll industry has grown from producing inexpensive novelty items to creating a multimillion-dollar global industry featuring high- quality, realistic love dolls. These dolls are designed and advertised for sexual stimulation, companionship, artistic representations of human fantasy, and other creative pursuits, such as photography. Made of flesh-like silicone, modern sex dolls sell from $3,500-$10,000.

The use of human simulacra for sexual stimulation is an enduring practice. However, the psychological community has said little on the subject. Early sexologists briefly reference Agalmatophilia or Statuphilia, a rare sexual attachment to statues. Today, the sex doll …

Aloe Striata Plant Defense Compounds Produced In Response To Jasmonic Acid, Salicylic Acid, And Eriophyid Mite Salivary Extract Elicitor Compounds, Fritz Light

Master's Theses

Aloe mites are herbivores of the genus Aloe (ALOACEAE) and are associated with hyperplastic growth in various aloe species, but the biochemistry of this interaction is poorly understood. In an effort to characterize plant defense responses to herbivory in the genus Aloe, a salivary extract was isolated from aloe mites (Aceria aloinis Keifer) and its bioactivity was tested using a hypocotyl elongation assay. Subsequently, Aloe striata plants were treated with jasmonic acid (JA), salicylic acid (SA), and the mite salivary extract. Using water and methanol, compounds of different polarity were extracted from aloe tissues that had been frozen …

A Comparative Analysis Of Low Cost Localization Methods For A Mario Kart Game Application, Anuranga Sajith Gunaratne

Master's Theses

In vehicle navigation systems, it is important to have accurate estimates of vehicle positioning. The process of determining positioning is called localization. There are two methods for localization, absolute positioning and relative positioning [1]. An absolute positioning system, such as Global Positioning System (GPS), determines the localization by using external distance and heading measures. Relative localization determines the position of an object based on its previously known location and through sensors that determine speed and heading. Examples of relative positioning sensors include wheel encoders, inertial sensors and accelerometers.

The objective of this thesis is to analyze different methods to perform …

Engineering Performance Of Polymer Amended Soils, Gary E. Welling

Master's Theses

A laboratory test program was undertaken to evaluate a series of engineering properties over a range of soil types; amendment types and addition rates; and moisture contents to enhance understanding of the engineering significance of polymer amendment. Four soils were manufactured and tested with varying ranges of fines and plasticity. A proprietary elastic copolymer was tested at addition rates of 0.5% to 2.5% (dry weight basis). Cement was tested at addition rates of 1% to 4%. Lime was tested at an 8% addition rate. Water addition rates ranged from 4% dry of optimum to 4% wet of optimum. Engineering properties …

Scale Model Shake Table Testing Of Shallow Embedded Foundations In Soft Clay, Steven Kuo

Master's Theses

This research involves shake table testing of 1g scale models that mimic the coupled seismic response of a structure on a shallow mat foundation and foundation soil (known as soil-foundation-structural-interaction or SFSI). In previous research, SFSI effects have been quantified through analytical models, numerical analyses, and limited field data. This research works towards increasing the amount of empirical data through scale model shake table testing. A suite of earthquake time histories is considered in evaluating a nominal 10^th scale soil-structure model using a flexible wall barrel on a 1-D shake table. San Francisco Young Bay Mud (YBM) is used …

Touchspice Vs. Reactive-Spice: A Human-Computer Interaction Perspective, Joshua Martin O'Hara

Master's Theses

Traditional SPICE simulation tools and applications of circuit theory lack real-time interaction and feedback. The goal of this thesis was to create an interactive physical environment to allow the manipulation and simulation of discrete electrical components in near-real-time while optimizing and streamlining the human-computer interaction (HCI) elements to make the user experience as positive and transparent as possible. This type of HCI and near-real-time simulation feedback would allow for the instant realization of how the parameters of each discrete component or hardware module affect the overall simulation and response of the circuit.

The scope of this thesis is to research, …

The Relationship Between Parent Nutrition Knowledge Level And Child Weight Status, Jameshyia Shandria Ballard

Master's Theses

The purpose of this study was to determine if nutrition knowledge of parents was related to the weight status of preschool-aged children. Objectives of this study included determining if relationships existed between parent knowledge of the 2010 Dietary Guidelines and child weight status, between parent knowledge of serving sizes and child weight status, and between overall parent nutrition knowledge and child weight status.

Data were obtained from 101 parents enrolled in a Head Start program in southern Mississippi. Weight status was obtained from 101 three to five year old children. Parent data was collected via survey, developed by the principal …

A Bloody Yesteryear And A Brighter Tomorrow: Late Cold War Anti-Heroes In The 1980s Graphic Novels Of Alan Moore And Frank Miller, Jeremy Andrew Defatta

Master's Theses

The 1980s—the last decade of the Cold War between the West and the Soviet Union—was a time of great change in the medium of graphic literature. Among the writers who changed superhero comic books through such strategies as the adoption of the anti-hero concept were Alan Moore and Frank Miller. In Watchmen and V for Vendetta, Alan Moore presents his super anti-heroes as intellectuals whose missions are the transformation and disruption of a national status quo in order to foster a brighter future. In Batman: The Dark Knight Returns and Daredevil: Born Again, Frank Miller presents his reinvented …

Bacterioplankton Production In The Western Mississippi Sound And The Role Of Photosynthetic Extracellular Release As A Driver Of Bacterial Production, Amy Michele Glover

Master's Theses

Bacterioplankton growth and metabolic activities are a vital component in structuring marine and estuarine ecosystems. In this study, bacterial production (BP) was investigated at two separate stations in the western Mississippi Sound (MS). One was an inshore site outside of the Bay of St. Louis and the other site was located in the transition zone (offshore) between the MS and Mississippi Bight, just south of Cat Island. Bacterial production (BP) was analyzed using the addition of ¹⁴C leucine to natural water samples. In addition, samples were augmented with algal exudates in order to investigate BP based on uptake of …

Anode Material Testing For Marine Sediment Microbial Fuel Cells, Andrew John Quaid

Master's Theses

Research on the power production of the microbial fuel cell has increased in the past decade. The sediment microbial fuel cell is a type of fuel cell that uses the environment of submerged sediments to provide a natural voltage difference. The fuel cell is comprised of an anode buried in the sediment and a cathode that is held in the overlying water column. The process of electron transfer to the anode is catalyzed by anaerobic bacteria in the sediment. The anaerobic bacteria have that are able to catalyze the electron transfer have been termed exoelectrogenic. The increase in scientific research …

Opportunistic Random Media Access In Wlans, Chong Tang

Master's Theses

This thesis proposes a new medium access protocol for IEEE 802.11 wireless local area networks, which is called opp01tunistic medium access. The protocol changes the media access opportunities of nodes by adjusting the contention window dynamically according to the different bit rates. Thereby, the protocol can reduce collision and improve throughput significantly. The n·aditional IEEE 802.11 standards access channel with binary exponential back-off algorithm and all nodes choose the back-off interval from the same initial range. The new protocol in this thesis divides nodes as well as contention windows in proportion to data rate. It offers three methods to group …

Single Liquid-Liquid Extraction Of Delta-9-Tetrahydrocannabinol And 11-Nor-Carboxy-Delta-9-Tetrahydrocannabinol At An Acidic Ph, Meghan Ann Tanner

Master's Theses

Because of the high occurrence of marijuana usage in the workplace and in driving under the influence cases, it is important to test for both delta-9-THC and delta-9-THCA in order to determine current and recent usage. The laboratory preparation and analysis of delta-9-THC and delta-9-THCA in urine should be as cost and time efficient as possible. Current extraction of delta-9-THC and delta-9-THCA from urine requires two separate techniques for each. Because delta-9-THC is nonacidic, while delta-9-THCA is acidic, the extractions involve two separate pH levels, while GC/MS analysis requires two separate methods. This separation requires a great deal of time …

Immunostimulatory And Cellular Toxic Effects Of Single-Stranded Rna On Cancer Cells, Chengwen Teng

Master's Theses

Whether 5'-triphosphate-single-stranded-RNA (5 '-ppp-ssRNA) is immunostimulatory was controversial in the literature. In order to clarify the immunostimulatory effect of 5'-ppp-ssRNA, we synthesized ssRNAs and tested the IFNp (interferon-beta) level and cellular toxicity of ssRNAs in SKOV3 cells. In this work, we confirmed that 5'-ppp-ssRNA (~ 60nt) was immunostimulatory and toxic in SKOV3 cells. 5'-ppp-ssRNA (~ 60nt) led to IFN-P induction and apoptosis in SKOV3 cells. Longer 5' ppp- ssRNA tended to have a higher immunostimulatory effect and cellular toxicity than shorter 5'-ppp-ssRNA. 5'-ppp-ssRNA was more immunostimulatory and toxic than 5'- 0H-ssRNA. If the incubation time of ssRNAs increased, the toxicity …

Effects Of Hurricane Disturbance On The Stopover Ecology Of Intercontinental Landbird Migrants In Coastal Louisiana, Emily Johanna Lain

Master's Theses

Few studies have considered the impact of weather events on migratory birds during stopover, and essentially none on how hurricanes affect their stopover biology during spring passage. About two thirds of eastern North American forest breeding bird species migrate twice annually between temperate breeding areas and subtropical and tropical wintering grounds, and movement in relation to the Gulf of Mexico (GOM) is a conspicuous and important part of that migration system. During inclement weather or winds inconsistent with travel direction, migratory birds oft.en/a/lout and concentrate by the thousands in forest patches that occur along the northern coast of the GOM. …

The Effect Of Poss Modified Montmorillonite On Elastomer Nanocomposites, Elana Celeste Lewis

Master's Theses

The goal of this thesis was to define the structural factors that determine performance in clay/rubber nanocomposites when polyhedral oligomeric silsesquioxane (POSS) is used as a dispersant. POSS has been shown previously to enhance clay, metal oxides, and carbon nanotube dispersion in thermoplastics matrices, but their performance in rubber systems has not yet been explored. There is little fundamental understanding of how POSS interacts with clay and how these modified fillers react with rubber matrices. This thesis aims to develop a greater understanding of the mechanisms of POSS-clay modification through the examination of two different POSS-clay systems and their effect …

Designing And Developing An Alternative Implementation Of The Digital Bathymetric Database, Variable Resolution (Dbdb-V), Donald Lester Brandon Jr.

Master's Theses

This documentation describes a project to design and develop an alternative implementation of the Digital Bathymetric Database Variable Resolution (DBDB-V) that will allow efficient ingestion into Geospatial Information System (GIS). DBDB-V is a well-known storage facility for wide-reaching bathymetry. It is created, maintained, and extensively used by the U.S. Navy, and it is seen in many applications within the public sector. Environmental Systems Research Institute (ESRI) develops a popular suite of GIS applications called ArcGIS Desktop that is used worldwide and offered to U.S. Navy programs though the Commercial Joint Mapping Toolkit (CJMTK). …

Analysis Methods And Characterization Of The Electrical Properties Of Nanostructured Particle-Containing Polymer Thin Films, Steven Lee Bunkley

Master's Theses

Polymeric thin film materials exhibit extreme electrical properties that can be difficult to measure in a repeatable fashion. The primary goal of this research was to establish a reliable method for categorizing the electrical properties of elastomeric thin film polymeric materials, including surface and bulk conductivity and current versus voltage material response. Since the electrical response will be affected by environmental conditions such as temperature and humidity, a controlled environmental chamber must be designed which will readily accommodate the necessary equipment, computer monitoring of the environment, and the facile handing of polymeric thin-films. Without such an environment, the electrical properties …

Zifazah: A Scientific Visualization Language For Tensor Field Visualizations, Haipeng Cai

Master's Theses

This thesis presents the design and prototype implementation of a scientific visualization language called Zifazah for composing and exploring 3D visualizations of diffusion tensor magnetic resonance imaging (DT-MRI or DTI) data. Unlike existing tools allowing flexible customization of data visualizations that are programmer-oriented, Zifazah focuses on domain scientists as end users in order to enable them to freely compose visualizations of their scientific data set. Verbal descriptions of end users about how they would build and explore DTI visualizations are analyzed to collect syntax, semantics, and control structures of the language. Zifazah makes use of the initial set of lexical …

Evaluating Macrobenthic Indicators Of Organic Enrichment And Hypoxia Within The Coastal Mississippi Hypoxic Zone, Daneen P. Menke

Master's Theses

Macrobenthic communities offer effective indicators of biotic integrity, but their use for distinguishing anthropogenic from natural stress is tricky because coastal taxa are eurytolerant. Effective coastal management calls for benthic indicators that respond to specific stressors, apply across different habitats, and reflect ecosystem function. Macrobenthic process metrics based on body-size descriptors should reflect ecosystem function and be useful for assessing the effects of eutrophication. Functional trait analysis should reflect the functional diversity of the community. Coastal Mississippi experienced widespread and sustained hypoxia throughout summer 2008. Site 6 located on the 10-m isobath in the center of the 2008 hypoxic zone …