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Predicting Electron Insert Output Factors At Nominal And Extended Source To Surface Distance, Ahmet Bulut Jan 2002

Predicting Electron Insert Output Factors At Nominal And Extended Source To Surface Distance, Ahmet Bulut

LSU Master's Theses

Two Varian linear accelerators were used to test the modified sector-integration method. This method can predict the electron insert factor for arbitrary inserts at different source to surface distances (SSD). The effective source distances (SSDeff) and insert factors (IF) for several accelerators are compared. The relationship of IF and SSDeff for machine type, energy, cone size, insert size and SSD is presented. The results were fed into the electron output determination module of an existing monitor unit calculator (MUCalc) which uses the modified sector integration method. Prediction and measurements were compared for various clinical inserts at several …

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The World Wide Web As A Vehicle For Advertising Movies To College Students: An Exploratory Study, Xiaoge Hu Jan 2002

The World Wide Web As A Vehicle For Advertising Movies To College Students: An Exploratory Study, Xiaoge Hu

LSU Master's Theses

The purpose of this study is to explore the World Wide Web as a vehicle for advertising movies to college students. Through a survey of LSU students, this study finds that online promotions as vehicles for advertising movies have great potential. Movie promotion websites are rated the second most effective form of movie advertising after television. The study found that people surf movie promotion websites mainly for movie show times, movie plot and cast information to compare film choices, and movie ticket purchases. The huge amount of data available and the 24/7 access to the internet is an important advantage. …

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Factors Which Influence Faculty Attitudes And Perceptions Of Distance Education In Analytical Subject Areas, Jeffrey G. Sumrall Jan 2002

Factors Which Influence Faculty Attitudes And Perceptions Of Distance Education In Analytical Subject Areas, Jeffrey G. Sumrall

LSU Doctoral Dissertations

This study focuses on current faculty attitudes and perceptions of distance education. A thorough review of literature indicates that faculty members are critical elements of distance education delivery and that certain factors (tenure, departmental incentives, gender, age) influence faculty participation. The main hypothesis being investigated is whether or not the analytical nature of the course is in fact the prime indicator in faculty participation. Faculty members from three randomly chosen SREB member institutions were surveyed. The purpose for choosing SREB member institutions for the population was for generalizing the findings to higher education institutions throughout the Southeastern United States. The …

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Buckling Analysis Of Grid Stiffened Composite Structures, Samuel Kidane Jan 2002

Buckling Analysis Of Grid Stiffened Composite Structures, Samuel Kidane

LSU Master's Theses

Buckling of a stiffened composite cylinder is a very complex phenomenon that involves complex interactions between the skin and the stiffeners. Depending on different configurations of the skin and stiffener, different buckling failure modes and failure loads are observed in stiffened cylinders. In this work failure modes and buckling loads of stiffened composite cylinders under uniaxial loading condition is investigated by using analytical and experimental approaches. In the first Chapter an improved smeared method is developed to model the buckling problem of an isogird stiffened composite cylinder. In this model the stiffness contributions of the stiffeners is computed by analyzing …

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Non-Linear Kinematic Hardening Model For Multiaxial Cyclic Plasticity, Marcio Costa Araujo Jan 2002

Non-Linear Kinematic Hardening Model For Multiaxial Cyclic Plasticity, Marcio Costa Araujo

LSU Master's Theses

A model of kinematic work hardening based on Frederick and Armstrong (1966), Phillips and Weng (1975), Chaboche (1979), and Voyiadjis and Basuroychowdhury (1998) is proposed for metal like behavior materials. In this proposed model, ratcheting is taken into account through the observation of the backstress evolution equation, modified by the addition of a new term, . Experimental observations made by Phillips and Lee (1979) showed that the direction of the movement of the center of the yield surface occurs in between the stress rate tensor and the plastic strain rate tensor directions. The new term, added to Chaboche model (1979), …

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Significance Of Variations Among Ancient Deltaic Deposits In The Arkoma Basin, North-Central Arkansas, Christine Michelle Wright Jan 2002

Significance Of Variations Among Ancient Deltaic Deposits In The Arkoma Basin, North-Central Arkansas, Christine Michelle Wright

LSU Master's Theses

The Arkoma Basin is one of several foreland basins formed in association with the Ouachita orogeny. The Arkoma Basin has been studied in depth with regard to stratigraphy, depositional environments, structure and its relationship to the Appalachian-Ouachita orogenic event. This study focuses on the variability of the deltaic deposits within the Arkoma Basin and the significance of the variables to both the delta complex and the overall tectonic setting. The specific characteristics to be investigated include variations in paleocurrent directions, bed thicknesses, bed geometries, organic contents, sand/shale ratios, mineral assemblages and fossil assemblages. In the case of the Arkoma deltaic …

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Wastewater Plume Dynamics And Bacteria Transport Within The Marshland Upwelling System, Stephen David Richardson Jan 2002

Wastewater Plume Dynamics And Bacteria Transport Within The Marshland Upwelling System, Stephen David Richardson

LSU Master's Theses

The marshland upwelling system (MUS) serves as an alternative onsite method for the treatment of domestic wastewater derived from coastal communities. Previous studies on the MUS have focused on the efficacy of the system for the removal of fecal pathogens from settled and secondarily-treated wastewater sources. The objectives of this research were to: 1) characterize the extent of wastewater migration within the MUS, 2) evaluate the effectiveness of the MUS in removing fecal bacteria, 3) identify the mechanisms responsible for fecal coliform retention within the subsurface, and 4) describe the transport of fecal coliforms in a sand media based on …

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The Influence Of Imagined Interactions On Verbal Fluency, Charles Choi Jan 2002

The Influence Of Imagined Interactions On Verbal Fluency, Charles Choi

LSU Master's Theses

Imagined interactions (IIs) are a type of social cognition and mental imagery whereby actors imagine an interaction with others for the purposes of planning. Within actual encounters, verbal fluency is a characteristic that contributes to the speaker's credibility. The planning that takes place through imagined dialogues can help a speaker overcome disfluency found in speech. This study shows that improvements in speaking style are also dependent upon the trait of communication apprehension that an individual experiences. Visualization can decrease apprehension levels, thus producing higher verbal fluency. Results from this study indicate planning's influence in the reduction of silent pauses but …

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Fine Aggregate Characterization Using Digital Image Analysis, Tongyan Pan Jan 2002

Fine Aggregate Characterization Using Digital Image Analysis, Tongyan Pan

LSU Master's Theses

A comprehensive literature review shows that performance of hot mix asphalt (HMA) is influenced by properties of aggregate. Current situation is that only limited efforts were dedicated to aggregate tests and criteria on aggregate, compared to researches on new binder tests, especially to that of fine aggregate. Superpave (Superior Performing Asphalt Pavement) tests/criteria on aggregate need to reflect those properties that influence performance. Representatives of the aggregate industry and the Superpave Mixture/Aggregate ETG (Expert Task Group) have reached the consensus for the need to improve aggregate tests and criteria as one of the most needed aspects left to complete in …

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Parametric And Sensitivity Analysis Of A Vibratory Automobile Model, Kanika Nicole Vessel Jan 2002

Parametric And Sensitivity Analysis Of A Vibratory Automobile Model, Kanika Nicole Vessel

LSU Master's Theses

Vibration response is an important aspect of any engineering problem. This thesis deals with developing a method to obtain the vibration, parametric and sensitivity of an automobile analyzed as a 2-DOF rigid body system with damping. The focus of the vibration analysis is to obtain the poles, eigenvectors, and natural frequencies of the system. The parametric analysis gave information on how the natural frequency is affected when one of the parameters is perturbed. Information about how much the system is affected by the change in one parameter is what is obtained from the sensitivity analysis. The theoretical solution contained in …

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A Comparison Of Storm Hydrographs From Small Urban Watersheds With Different Land Use Patterns In Baton Rouge, Josey Wade Walker Jan 2002

A Comparison Of Storm Hydrographs From Small Urban Watersheds With Different Land Use Patterns In Baton Rouge, Josey Wade Walker

LSU Master's Theses

Statistics gathered by FEMA indicate that nine of ten federal disasters are related to flooding. Research has demonstrated that increases in flooding can be contributed to urbanization or the construction of new residential and commercial developments (Anderson, 1970; Arnold & Gibbons, 1996; Putnam, 1972). New development has two main problems associated with it. First is the increase in impervious surfaces due to new parking lots, buildings, and streets (Booth & Leavitt, 1999; Seaburn, 1969). Second is the elimination of natural vegetation, which reduces evapotranspiration and lowers the soil’s ability to absorb precipitation (Hewlett, 1982). This study first demonstrates the relationship …

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Development Of A Magnetite Tracer Protocol For Seasonal Measurement Of Bed Sediment Biodiffusion Coefficients, Paul D. Libbers Jan 2002

Development Of A Magnetite Tracer Protocol For Seasonal Measurement Of Bed Sediment Biodiffusion Coefficients, Paul D. Libbers

LSU Master's Theses

This thesis describes the development of a particle tracer technique for making short-term, in situ measurements of aquatic bed sediment biodiffusion coefficients. The bioturbation process in the upper sediment layers of streams, lakes, estuaries, and the marine environment moves particles and porewater. When present, organic chemicals, metals, colloids, etc., are transported across these layers and exchanges may occur at the sediment-water interface. Fickian biodiffusion coefficients that characterize such particle movements, Db (cm2/yr), are used for assessing chemical diagenesis rates and contaminant fluxes and are specific to each site. Chemical Fate and Transport (CFaT) models, developed for tracking contaminants in aquatic …

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Distributary Mouth Bar Formation And Channel Bifurcation In The Wax Lake Delta, Atchafalaya Bay, Louisiana, Anton J. Dumars Jan 2002

Distributary Mouth Bar Formation And Channel Bifurcation In The Wax Lake Delta, Atchafalaya Bay, Louisiana, Anton J. Dumars

LSU Master's Theses

The Mississippi River has undergone at least seven cyclic avulsions during the Holocene epoch. The latest avulsion, down the Atchafalaya River into the Gulf of Mexico, has produced two bayhead deltas prograding into Atchafalaya Bay. The Wax Lake Delta, typical of other Mississippi sub-deltas, has a natural anastomosing channel pattern. In contrast, the Atchafalaya Delta, situated in the eastern side of the Bay, has experienced sporadic and limited growth due to the dredging of a navigation channel below natural depth. Channel bifurcation, and sediment transport processes and responses, were investigated in the Wax Lake Delta, using channel flow velocities, suspended …

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The Synthesis Of New Biotin Derivatives And Their Bioactivity, Latisha Chanette Johnson Jan 2002

The Synthesis Of New Biotin Derivatives And Their Bioactivity, Latisha Chanette Johnson

LSU Master's Theses

Biotin is an essential growth factor found in all living cells. It functions as a cofactor for a group of coenzymes that catalyze transcarboxylation, decarboxylation, and carboxylation reactions. Acetyl CoA carboxylase catalyzes the first committed and regulated step in fatty acid synthesis in which malonyl CoA is the product. The biotin-dependent enzyme is found in all animals, plants, and bacteria. We studied the kinetic and structural aspects of acetyl CoA carboxylase, and in 1999 we reported the bioactivity and total synthesis of a unique first generation biotin-derived inhibitor of acetyl CoA carboxylase, 1(BP1). Kinetic studies on the activity of E. …

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Offline And Online Variants Of The Traveling Salesman Problem, John Ebenezer Augustine Jan 2002

Offline And Online Variants Of The Traveling Salesman Problem, John Ebenezer Augustine

LSU Master's Theses

In this thesis, we study several well-motivated variants of the Traveling Salesman Problem (TSP). First, we consider makespan minimization for vehicle scheduling problems on trees with release and handling times. 2-approximation algorithms were known for several variants of the single vehicle problem on a path. A 3/2-approximation algorithm was known for the single vehicle problem on a path where there is a fixed starting point and the vehicle must return to the starting point upon completion. Karuno, Nagamochi and Ibaraki give a 2-approximation algorithm for the single vehicle problem on trees. We develop a Polynomial Time Approximation Scheme (PTAS) for …

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Discrete Mathematics Topics In The Secondary School Curriculum, Aimee Beth Boyd Jan 2002

Discrete Mathematics Topics In The Secondary School Curriculum, Aimee Beth Boyd

LSU Master's Theses

This thesis discusses two topics of discrete mathematics in a manner suitable for presentation at a secondary-school level. The introduction outlines the benefits of including discrete mathematics in the secondary-school curriculum. The two chapters which follow include detailed treatment of the two selected topics: the Traveling Salesman Problem and RSA encryption. The discussion of the Traveling Salesman Problem consists of introduction to the problem through several real-life scenarios, followed by a discussion of various methods for solving the problem. We discuss exact and approximate algorithms together with their computational complexity and practical limitations. The discussion of RSA encryption begins with …

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Discrimination Of Cardiac Health And Disease By Assessment Of Heart Rate Variability: Wavelet Vs. Fast Fourier Transformation, Jusonda Leray Derouen Jan 2002

Discrimination Of Cardiac Health And Disease By Assessment Of Heart Rate Variability: Wavelet Vs. Fast Fourier Transformation, Jusonda Leray Derouen

LSU Master's Theses

The autonomic nervous system (ANS) modulation of the heart is of clinical importance because of its relevance to risk of life threatening arrhythmic events. Decomposition of heart rate variability (HRV) has been used to quantify ANS control of the heart. The traditional method for frequency analysis has involved the use of fast Fourier transformation (FFT). However, heart rate data typically violate assumptions of the FFT. Therefore, the assessment of HRV may benefit from other, potentially more suitable, mathematical approaches. For example, the discrete wavelet transformation (DWT) appears to have promise with respect to its ability to discriminate between healthy and …

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Louisiana Mass Media Perceptions Of The Lsu Agcenter's Communications Effort, Robert James Soileau Jan 2002

Louisiana Mass Media Perceptions Of The Lsu Agcenter's Communications Effort, Robert James Soileau

LSU Master's Theses

LSU AgCenter Communications sends news stories and materials to all three major mass media for news - newspaper, radio and television - in the state of Louisiana. These news releases are designed to educate and inform the general public about LSU AgCenter programs and research through the Louisiana Cooperative Extension Service and the Louisiana Agricultural Experiment Station. LSU AgCenter Communications wanted to know the effectiveness of its news effort in terms of usage by the media, and what was the media’s perception of the LSU AgCenter and the topics covered by communications. Three researcher-designed surveys were developed, one for each …

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The Importance Of Zooplankton In The Diets Of Blue Runner (Caranx Crysos) Near Offshore Petroleum Platforms In The Northern Gulf Of Mexico, Sean Francis Keenan Jan 2002

The Importance Of Zooplankton In The Diets Of Blue Runner (Caranx Crysos) Near Offshore Petroleum Platforms In The Northern Gulf Of Mexico, Sean Francis Keenan

LSU Master's Theses

Blue runner (Caranx crysos), common around offshore petroleum platforms in the Gulf of Mexico, were found to forage extensively on meso- and macro-zooplankton during the summer months. Larval decapods and stomatopods, hyperiid amphipods, pteropods, and larval and juvenile fishes were common components of their diet. Feeding periodicity results suggest that blue runner around platforms were capable of feeding throughout the night at the same intensity as the day. Size selectivity indicated that larger prey, such as fish were consumed during the night and smaller decapod crustaceans were consumed during the day. Blue runner collected from open waters away from platforms …

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Sedimentation Rates And Metal Retention In An Urban Louisiana Swamp, Renee Lynn Sanders Jan 2002

Sedimentation Rates And Metal Retention In An Urban Louisiana Swamp, Renee Lynn Sanders

LSU Master's Theses

Naturally vegetated areas converted to urban uses increases impervious surfaces in a watershed with corresponding increases in nutrient, sediment, and metal loadings to downstream ecosystems. Wetlands mitigate detrimental impacts by transforming or retaining pollutants. Current and historic sedimentation and metal retention rates were measured in an urban, depressional wetland in Baton Rouge, Louisiana to evaluate landscape position and watershed development on these processes. Sedimentation disks, feldspar marker horizons, and Cs137 analyses were used in three distinct landscape positions. Inflow channels had the highest elevation and water velocity while the interior was located in the lowest elevations with the longest hydroperiod. …

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A State-Of-The-Practice Review Of Hurricane Evacuation Plans And Policies, Elba Alicia Urbina Jan 2002

A State-Of-The-Practice Review Of Hurricane Evacuation Plans And Policies, Elba Alicia Urbina

LSU Master's Theses

The events of recent hurricane seasons have made evacuation one of the leading emergency management issues. In 1998 and 1999, Hurricanes Georges and Floyd precipitated the two largest evacuations in U.S. history and perhaps, its two largest traffic jams. In response to the problems experienced during these events, many State Department’s of Transportation (DOT) have begun to take a more active role in the planning, management, and operation of hurricane evacuations. Since the involvement of transportation professionals in the evacuation field has been a fairly recent development; many of the newest practices and policies have only been used once, if …

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Denitrification Potential Of Sediment From A Future Mississippi River Diversion Site In Louisiana, Roy Ryuta Iwai Jan 2002

Denitrification Potential Of Sediment From A Future Mississippi River Diversion Site In Louisiana, Roy Ryuta Iwai

LSU Master's Theses

Denitrification potential was determined in surface sediment from Lake Cataouatche, the receiving basin for a future Mississippi River diversion located in the northern portion of the Barataria Basin estuary. Nitrate removal and denitrification was measured in the laboratory using static sediment microcosms flooded with lake water. Dissolved potassium nitrate (KNO3) was added to the microcosms to achieve: 1) an initial nitrate concentration similar to the mean Mississippi River concentration (~1.4 mg NO3-N l-1), and, 2) a high initial nitrate concentration to elicit a denitrification potential (~50 mg NO3-N l-1). Denitrification …

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Treatment Of Organic And Inorganic Pollutants In Municipal Wastewater By Agricultural By-Product Based Granular Activated Carbons (Gac), Rishipal Rastrapal Bansode Jan 2002

Treatment Of Organic And Inorganic Pollutants In Municipal Wastewater By Agricultural By-Product Based Granular Activated Carbons (Gac), Rishipal Rastrapal Bansode

LSU Master's Theses

The objective of this investigation was to evaluate pecan and almond shell-based granular activated carbon's viability to effectively remove organic and inorganic pollutants in municipal wastewater compared to commercial carbons, Filtrasorb 200 (bituminous coal-based), and GRC-20, 206C AW (coconut shell-based). The solution to the objective was approached under three distinct phases, namely (I) physical and chemical characterization of the pecan and almond shell-based experimental and bituminous coal and coconut shell-based commercial granular activated carbons; (II) treatment of organic contaminants in municipal wastewater by experimental and commercial GACs; (III) treatment of inorganic contaminants in municipal wastewater by experimental and commercial GACs. …

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Development Of Trip Generation Models Of Hurricane Evacuation, Bing Mei Jan 2002

Development Of Trip Generation Models Of Hurricane Evacuation, Bing Mei

LSU Master's Theses

In this study, alternative trip generation models for hurricane evacuation movement were developed using logistic regression and neural networks. The southwest Louisiana post-Andrew survey data were used for model estimation, validation, and comparison. The performance of the alternative models was compared with each other as well as against that of an existing evacuation model, the PBS&J model, developed for the same area. The results showed that the models developed in this study displayed similar performance. It was also found that the models developed in this study performed better than the existing PBS&J model in predicting household evacuation trip generation for …

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Validation Of Annagnps At The Field And Farm-Scale Using An Integrated Agnps/Gis System, Glenn M. Suir Jan 2002

Validation Of Annagnps At The Field And Farm-Scale Using An Integrated Agnps/Gis System, Glenn M. Suir

LSU Master's Theses

Non-Point Source (NPS) pollution models are effective watershed-scale predictors of NPS loadings and useful evaluators of agricultural Best Management Practices (BMPs) and water quality Total Maximum Daily Loads (TMDLs). The work reported in this thesis examined two applications of the AGricultural Non-Point-Source (AGNPS) pollution model: 1) predicting surface runoff, nutrient loading, and sediment yield predictions for an artificially delineated farm-scale watershed; and 2) evaluating relative benefits of different BMPs on reducing sediment accumulation in a lake surrounded by agricultural land. A procedure using identification, extraction, and processing of critical area data using an ArcView Geographic Information System (GIS) was used …

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Characterization Of An In Vivo Diode Dosimetry System For Clinical Use, Kai Huang Jan 2002

Characterization Of An In Vivo Diode Dosimetry System For Clinical Use, Kai Huang

LSU Master's Theses

An in vivo dosimetry system that uses p-type semiconductor diodes with buildup caps was characterized for clinical use. The dose per pulse dependence was investigated. This was done by altering the SSD, field size and wedge for photons, and by altering SSD and cone size for electrons. The off-axis correction and effect of changing repetition rate were also investigated. A model was made to fit the measured diode correction factors.

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Agroeconomic Effect Of Soil Solarization On Fall-Planted Lettuce, Julio Eduardo Hasing Jan 2002

Agroeconomic Effect Of Soil Solarization On Fall-Planted Lettuce, Julio Eduardo Hasing

LSU Master's Theses

The effects of summer soil solarization on the production and economics of four lettuce cultivars were evaluated in two plantings conducted during the fall growing season of 2001, to determine the feasibility of integrating strip-solarization in plasticulture cropping systems. Soil was solarized for 53 and 34 days for the first and second plantings, respectively, using transparent (T4, T5) and black films (T6) that were kept in place as plastic mulches in raised beds through the fall season. Soil temperatures were recorded at 5 and 10-cm depths at 1-hour intervals during the solarization period. Mulch on T5 was painted black before …

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Techniques And Algorithms For Immersive And Interactive Visualization Of Large Datasets, Ashish Sharma Jan 2002

Techniques And Algorithms For Immersive And Interactive Visualization Of Large Datasets, Ashish Sharma

LSU Master's Theses

Advances in computing power have made it possible for scientists to perform atomistic simulations of material systems that range in size, from a few hundred thousand atoms to one billion atoms. An immersive and interactive walkthrough of such datasets is an ideal method for exploring and understanding the complex material processes in these simulations. However rendering such large datasets at interactive frame rates is a major challenge. A scalable visualization platform is developed that is scalable and allows interactive exploration in an immersive, virtual environment. The system uses an octree based data management system that forms the core of the …

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A New Approach To Evaluate Fracture Strength Of Uv-Liga Fabricated Nickel Specimens, Catherine Oropeza Jan 2002

A New Approach To Evaluate Fracture Strength Of Uv-Liga Fabricated Nickel Specimens, Catherine Oropeza

LSU Master's Theses

One of the major difficulties faced by MEMS researchers today is the lack of data regarding properties of electroplated metals or alloys at micro-levels as those produced by the LIGA and LIGA related process. These mechanical properties are not well known and they cannot be extrapolated from macro-scale data without experimental verification. This lack of technical information about microscale physical properties has affected the consistency and reliability of batch-fabricated components and leads to very low rates of successful fabrication. Therefore, this material issue is of vital importance to the development of LIGA technology and to its industrial applications. This thesis …

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Analytical Model To Control Off - Bottom Blowouts Utilizing The Concept Of Simultaneous Dynamic Seal And Bullheading, Victor Gerardo Vallejo-Arrieta Jan 2002

Analytical Model To Control Off - Bottom Blowouts Utilizing The Concept Of Simultaneous Dynamic Seal And Bullheading, Victor Gerardo Vallejo-Arrieta

LSU Doctoral Dissertations

The current methods for off - bottom control of blowouts involve pumping kill fluid into the well through an injection string. These are the dynamic kill and the momentum kill. The dynamic kill, which is based on the steady state system analysis approach, and the momentum kill, that is loosely based on the Newton's Second Law of Motion, have been used extensively in off-bottom control of actual blowouts. A comprehensive study of these two concepts was performed. The review included an analytical analysis of the published design techniques for both of these methods. The application of these techniques to several …

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