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2007

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Articles 4981 - 5010 of 5729

Full-Text Articles in Physical Sciences and Mathematics

Early Flotant Establishment And Growth Dynamics In A Nutrient Amended Wetland In The Lower Mississippi River Delta, Caleb W. Izdepski Jan 2007

Early Flotant Establishment And Growth Dynamics In A Nutrient Amended Wetland In The Lower Mississippi River Delta, Caleb W. Izdepski

LSU Master's Theses

Nutrient dynamics and seasonal marsh growth were examined in a newly formed Panicum virgatum floating marsh at Thibodaux LA. The floating marsh formed in a cleared area of forested wetland receiving secondarily treated effluent. Net Areal Primary Productivity (NAPP), total belowground biomass, NO3, and δ15N ratios varied significantly (P <0.05) along a 75m marsh transect while mean δ13C varied between plant species. The upland end of the transect had the highest NAPP (3876 g m-2y-1), total belowground biomass (4079.0 ± 298.5 g m-2), and mean NO3 (5.4 ± 2.9 mg l-1). The mean floating-marsh …


Effects Of Predator Activity On The Nesting Of American Black Ducks And Other Birds On Barrier Islands In The Mid-Atlantic Coast, Brian Joseph Arquilla Jan 2007

Effects Of Predator Activity On The Nesting Of American Black Ducks And Other Birds On Barrier Islands In The Mid-Atlantic Coast, Brian Joseph Arquilla

LSU Master's Theses

Landscape change throughout North America has resulted in heightened nest predator population and declining avian productivity. Essential to establishing effective management design is an understanding of differential predation pressure among avian groups as group specific responses to predation impact may exist. The objective of this study was to examine the efficacy of predator trapping on the nest success and density of ground nesting avifauna in 2004-2005 in the Virginia Coast Reserve, specifically dabbling ducks, Canada Goose and Willet. Second, we determine the impact of predation on ground nesting birds by relating indices of predator abundance to nest density and nest …


Evaluation Of Harvesting Disturbance And Establishment Practices On Early Height Growth Of Loblolly Pine (Pinus Taeda L.), Shanna Marie Mccarty Jan 2007

Evaluation Of Harvesting Disturbance And Establishment Practices On Early Height Growth Of Loblolly Pine (Pinus Taeda L.), Shanna Marie Mccarty

LSU Master's Theses

Land for forest plantations is declining while demand for forest products is increasing, creating concern over sustainable forest management. Maintenance of site productivity is fundamental to forest sustainability, and an assessment of cumulative height growth is a useful index of productivity. Loblolly pine height data were used from four research plantations installed by the project Cooperative Research in Sustainable Silviculture and Soil Productivity from Texas to Georgia. The sites vary in soil characteristics, management history, nutrient status at time of planting, and age (from 4 to 9 years). Each site is a randomized complete block design with a factorial treatment …


The Ecology Of Blacktail Redhorse Moxostoma Poecilurum In West Fork Thompson Creek, Louisiana, Jesse Adam Bahm Jan 2007

The Ecology Of Blacktail Redhorse Moxostoma Poecilurum In West Fork Thompson Creek, Louisiana, Jesse Adam Bahm

LSU Master's Theses

This study was designed to examine home range sizes and habitat use of blacktail redhorse Moxostoma poecilurum in West Fork Thompson Creek, Louisiana. Blacktail redhorse are a common non-game species found in Louisiana and other southeastern states. Adult blacktail redhorse (N=40; 187-273 mm total length) were implanted with radio transmitters and tracked twice weekly from February to September 2006 and from February to July 2007. To assess blacktail redhorse diet I analyzed 32 stomachs from fish collected by backpack electrofishing. I also conducted mark-recapture surveys of fish sampled monthly from May 2006 until July 2007. To assess homing ability in …


Protocol Development For Pro-Active Emergency Responses By Veterinary Clinics And Hospitals, Laura Marie Basirico Jan 2007

Protocol Development For Pro-Active Emergency Responses By Veterinary Clinics And Hospitals, Laura Marie Basirico

LSU Master's Theses

The Gulf Coast hurricanes of 2005 necessitated the development of a guidance document concerning emergency preparedness and response for veterinary clinics and hospitals. The aftermaths of the largest natural disasters in United States' history, namely Hurricanes Katrina and Rita, brought to light the need for a protocol designed specifically for veterinarians and veterinary practitioners. Disaster management information was synthesized and modified to be subject-specific for the veterinary community. This synthesis resulted in the creation of the Veterinary Emergency Preparedness and Response (VEPR) manual and website. Two types of data were collected to develop the emergency protocol; interviews with veterinarians and …


Assessment And Analysis Of Quikscat And Coamps Model Vector Wind Products For The Gulf Of Mexico: A Long-Term And Hurricane Perspective, Neha Sharma Jan 2007

Assessment And Analysis Of Quikscat And Coamps Model Vector Wind Products For The Gulf Of Mexico: A Long-Term And Hurricane Perspective, Neha Sharma

LSU Master's Theses

Global weather changes have become a matter of grave concern in hurricane prone areas as intensities of hurricanes are observed to be increasing every year, necessitating improved monitoring capabilities. NASA’s QuikSCAT satellite sensor has provided significant support in analyzing and forecasting winds for the past 8 years. In this study, the performance of QuikSCAT products, including JPL’s latest L2B 12.5km swath winds, was evaluated against buoy-measured winds in the Gulf of Mexico. The long-term study period was 1/2005 – 2/2007. The Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) was also assessed. The regression analyses showed very good results for QuikSCAT products, …


Workshop Report — Crawdad Workshop 2006, Jihwang Yeo, Tristan Henderson, David Kotz Jan 2007

Workshop Report — Crawdad Workshop 2006, Jihwang Yeo, Tristan Henderson, David Kotz

Dartmouth Scholarship

Wireless network researchers are seriously starved for data about how real users, applications, and devices use real networks under real network conditions. CRAWDAD, the Community Resource for Archiving Wireless Data at Dartmouth, is an NSF-funded project that is building a wireless network data archive for the research community. We host wireless data, and provide tools and documents to make it easy to collect and use wireless network data. We hope that this resource will help researchers to identify and evaluate real and interesting problems in mobile and pervasive computing. This report outlines the CRAWDAD project and summarizes the second CRAWDAD …


Bridges And Barriers To Developing And Conducting Interdisciplinary Graduate-Student Team Research, Max Nielsen-Pincus, Wayde Cameron Morse, Jo Ellen Force, J. D. Wulfhorst Jan 2007

Bridges And Barriers To Developing And Conducting Interdisciplinary Graduate-Student Team Research, Max Nielsen-Pincus, Wayde Cameron Morse, Jo Ellen Force, J. D. Wulfhorst

Environmental Science and Management Faculty Publications and Presentations

Understanding complex socio-environmental problems requires specialists from multiple disciplines to integrate research efforts. Programs such as the National Science Foundation’s Integrative Graduate Education and Research Traineeship facilitate integrated research efforts and change the way academic institutions train future leaders and scientists. The University of Idaho and the Tropical Agricultural Research and Higher Education Center in Costa Rica collaborate on a joint research program focusing on biodiversity conservation and sustainable production in fragmented landscapes. We first present a spectrum of integration ranging from disciplinary to transdisciplinary across seven aspects of the research process. We then describe our experiences and lessons learned …


Environmental Factors Affecting The Distribution Of Native And Invasive Aquatic Plants In The Atchafalaya River Basin, Louisiana, U.S.A., Rachel Cathleen Walley Jan 2007

Environmental Factors Affecting The Distribution Of Native And Invasive Aquatic Plants In The Atchafalaya River Basin, Louisiana, U.S.A., Rachel Cathleen Walley

LSU Master's Theses

Over the last century, the aquatic macrophyte community of the Atchafalaya River Basin (ARB) has become increasingly dominated by invasive species. I used digital photography and GIS software to determine ARB macrophyte community composition by measuring percent cover of each plant species within five 0.25-m2 quadrats sampled from 108 sites in 2005 and 103 sites in 2006. Macrophyte community data and measurements of soil and water physicochemistry at each site were used to investigate environmental associations of the macrophytes inhabiting bayou, lake, excavated canal, and swamp habitats. Analyses indicated substantial differences in physicochemical conditions among habitats, but none of the …


Evaluation Of Anuran Richness In Restored Wetlands Of Central Louisiana, Sarah Jane Barlow Jan 2007

Evaluation Of Anuran Richness In Restored Wetlands Of Central Louisiana, Sarah Jane Barlow

LSU Master's Theses

Bottomland hardwood forests and associated fauna, including frogs, are disappearing. The 1990 Farm Bill created a wetland restoration program on private lands called the Wetland Reserve Program (WRP) that has the potential to reverse the declines in species associated with bottomland hardwood forests. As of September 2005, nearly 85,000 ha had been enrolled in Louisiana, but the structure and value of these wetlands to frogs is not known. I evaluated 22 restored and 8 reference wetlands from January through May in 2004 and 2005 to determine the effects of local and landscape scale habitat characteristics on frog species richness and …


Oregon Spartina Response Plan, Mary Pfauth, Mark Sytsma, Dennis Isaacson Jan 2007

Oregon Spartina Response Plan, Mary Pfauth, Mark Sytsma, Dennis Isaacson

Center for Lakes and Reservoirs Publications and Presentations

Four introduced, invasive species of Spartina (cordgrass) have been present in estuarine areas of the U.S. west coast for over a century. These Spartina species are ecological engineers- they cause severe alternations in the hydrology and food webs of invaded estuaries that are detrimental to native wildlife and commercial and recreational uses. Oregon has been relatively free of these weeds, with only two known infestations. One infestation was eradicated by Oregon Department of Agriculture and the other is currently under eradication by The Nature Conservancy.


Phenomenographic Study Of Students’ Problem Solving Approaches In Physics, Laura Walsh, Robert Howard, Brian Bowe Jan 2007

Phenomenographic Study Of Students’ Problem Solving Approaches In Physics, Laura Walsh, Robert Howard, Brian Bowe

Articles

This paper describes ongoing research investigating student approaches to quantitative and qualitative problem solving in physics. This empirical study was conducted using a phenomenographic approach to analyze data from individual semistructured problem solving interviews with 22 introductory college physics students. The main result of the study is a hierarchical set of categories that describe the students’ problem solving approaches in the context of introductory physics.


Rate And Equilibrium Constants For Reactions Of Coordinated Cyclohexadienyl Cations, Martin Galvin Jan 2007

Rate And Equilibrium Constants For Reactions Of Coordinated Cyclohexadienyl Cations, Martin Galvin

Doctoral

In this work, the nucleophilic reactions of ironcarbonyl coordinated cyclohexadienyl cations with water and hydroxide to produce the corresponding coordinated arene hydrate analogues was examined. These nucleophilic reactions are a key step in a synthetic route to convert arene cis-dihydrodiols to their trans-isomers via their tricarbonyliron coordinated complexes. The arene trans-dihydrodiols produced have significant potential to be used as chiral buildings blocks in synthetic chemistry and have the advantage that they are more stable then their cis-analogues The first cation studied was (п5-cyclohexadienyl)dicarbonyl-triphenylphosphineiron. An equilibrium constant, pKr, for formation of the coordinated arene hydrate (п4-exo-5-hydroxy-1,3-cyclohexadience)dicarbonyltriphenylphosphine-iron, from this coordinated cation was …


“Garbage On The Green”- A Waste Audit Event At The University Of North Florida, March 8, 2007, Stacy Wheeler Jan 2007

“Garbage On The Green”- A Waste Audit Event At The University Of North Florida, March 8, 2007, Stacy Wheeler

Garbage on the Green Reports

Approximately 135 undergraduate students participated in a waste characterization study at the University of North Florida (UNF) on March 8, 2007 that was titled Garbage on the Green. The purpose of the study was to identify and quantify the types and sources of materials in UNF’s solid waste stream. Findings from the study were used to generate new strategies for improving campus waste management and recycling programs. The study was funded by the Environmental Center and supported by the university administration, the city of Jacksonville, and a diverse group of regional public and private organizations.


In-Situ Measurement And Characterization Of Cloud Particles Using Digital In-Line Holography, Jacob P. Fugal Jan 2007

In-Situ Measurement And Characterization Of Cloud Particles Using Digital In-Line Holography, Jacob P. Fugal

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

Satellite measurement validations, climate models, atmospheric radiative transfer models and cloud models, all depend on accurate measurements of cloud particle size distributions, number densities, spatial distributions, and other parameters relevant to cloud microphysical processes. And many airborne instruments designed to measure size distributions and concentrations of cloud particles have large uncertainties in measuring number densities and size distributions of small ice crystals. HOLODEC (Holographic Detector for Clouds) is a new instrument that does not have many of these uncertainties and makes possible measurements that other probes have never made. The advantages of HOLODEC are inherent to the holographic method.

In …


Sub Space: Enhancing The Spatial Awareness Of Trainee Submariners Using 3d Simulation Environments, Michael Garrett Jan 2007

Sub Space: Enhancing The Spatial Awareness Of Trainee Submariners Using 3d Simulation Environments, Michael Garrett

Theses : Honours

Rapid advancements in computer technology have facilitated the development of practical and economically feasible three dimensional (3D) computer-generated simulation environments that have been utilized for training in a number of different fields. In particular, this development has been heavily influenced by innovations within the gaming industry, where First Person Shooter (FPS) games are often considered to be on the cutting edge of gaming technology in terms of visual fidelity and performance. 3D simulation environments built upon FPS gaming technologies can be used to realistically represent real world places, while also providing a dynamic and responsive experiential based learning environment for …


Observation Of Microslip Dynamics At High-Speed Microcontacts, Brian Borovsky, Adam M. Booth, Erin Manlove Jan 2007

Observation Of Microslip Dynamics At High-Speed Microcontacts, Brian Borovsky, Adam M. Booth, Erin Manlove

Geology Faculty Publications and Presentations

The high-speed tribological properties of microscale contacts are studied using an indenter probe and quartz crystal microbalance. Elastic and dissipative shear forces are monitored as a function of contact radius for sapphire/gold interfaces with an adsorbed octadecanethiol monolayer. We observe shear force transitions understood as taking the interface from slipping to stuck conditions. We relate this behavior to the presence of interfacial microslip. Dynamic modeling shows that our observations are consistent with an interface that, when sliding, experiences full slip during half of each cycle. We discuss the implications for this technique as a sensitive probe of sliding friction.


Distributed Resource Participation In Local Balancing Energy Markets, Judith Cardell Jan 2007

Distributed Resource Participation In Local Balancing Energy Markets, Judith Cardell

Engineering: Faculty Publications

In response to the new and potentially conflicting economic and technical demands of independent, distributed resources, the power system requires a new means for coordinating system and market operations. Price signals are one mechanism available to coordinate the operation of a power system in the emerging competitive markets. This paper discusses the integration of distributed resources into the operations of the power system by means of organizing the resources into microgrids and allowing them to participate in local electricity markets through responding to price signals. The simulations of price signals proposed in this paper successively expand upon the current open …


Effects Of Dissipation On A Quantum Critical Point With Disorder, Jose A. Hoyos, Chetan Kotabage, Thomas Vojta Jan 2007

Effects Of Dissipation On A Quantum Critical Point With Disorder, Jose A. Hoyos, Chetan Kotabage, Thomas Vojta

Physics Faculty Research & Creative Works

We study the effects of dissipation on a disordered quantum phase transition with O(N) order-parameter symmetry by applying a strong-disorder renormalization group to the Landau-Ginzburg-Wilson field theory of the problem. We find that Ohmic dissipation results in a nonperturbative infinite-randomness critical point with unconventional activated dynamical scaling while super-Ohmic damping leads to conventional behavior. We discuss applications to the superconductor-metal transition in nanowires and to the Hertz theory of the itinerant antiferromagnetic transition.


Microscopic-Macroscopic Simulations Of Rigid-Rod Polymer Hydrodynamics: Heterogeneity And Rheochaos, M. Gregory Forest, Ruhai Zhou, Qi Wang Jan 2007

Microscopic-Macroscopic Simulations Of Rigid-Rod Polymer Hydrodynamics: Heterogeneity And Rheochaos, M. Gregory Forest, Ruhai Zhou, Qi Wang

Mathematics & Statistics Faculty Publications

Rheochaos is a remarkable phenomenon of nematic (rigid-rod) polymers in steady shear, with sustained chaotic fluctuations of the orientational distribution of the rod ensemble. For monodomain dynamics, imposing spatial homogeneity and linear shear, rheochaos is a hallmark prediction of the Doi-Hess theory [M. Doi, J. Polym. Sci. Polym. Phys. Ed., 19 (1981), pp. 229-243; M. Doi and S. F. Edwards, The Theory of Polymer Dynamics, Oxford University Press, London, New York, 1986; S. Hess, Z. Naturforsch., 31 (1976), pp. 1034-1037. The model behavior is robust, captured by second-moment tensor approximations G. Rienäcker, M. Kröger, and S. Hess, Phys. Rev. …


Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske Jan 2007

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

This project focuses on the chemical bonding and interface formation of metal fission products with the coating materials used in tri-isotropic (TRISO) fuel particles for gas-cooled reactors. By combining surface- and bulk-sensitive spectroscopic methods, intermediate chemical phases at the interface, intermixing/ diffusion behavior, and the electronic interface structure as a function of material (metal and coating materials) and temperature are examined.

In the past year, emphasis was placed on a detailed analysis and description of the Cs/SiC interface formation process.


Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments Project, Denis Beller Jan 2007

Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments Project, Denis Beller

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct accelerator driven experiments, which will help demonstrate in the U.S. the ability to design, compute, and conduct ADSS experiments and to predict and measure source importance, coupling efficiency, sub-critical reactor kinetics and source-driven transients. In addition, databases will be created for both steady state and transient ADSS experiments for the nuclear community to develop and test new computational codes and methods, and the importance of a driving neutron source in various regions of different subcritical assemblies will be mapped. Experiments will be conducted and compared to calculations …


Criticality Studies For Urex Processes, Denis Beller Jan 2007

Criticality Studies For Urex Processes, Denis Beller

Separations Campaign (TRP)

The completion of criticality experiments for mixtures of transuranic actinides (TRU–includes Np, Pu, Am, and Cm) that will be created during the separation of used nuclear fuel may be a requirement in order to construct prototype plants for the Global Nuclear Energy Partnership. In this program and the Advanced Fuel Cycle Research and Development (AFC R&D) program that supports it, economic and environmental methods are being developed to reduce the impact of waste from commercial nuclear fuel cycles.

Recycling of used fuel by chemically separating it into U, fission products, and TRU would be the first step in this new …


Journal Of Mathematics And Science: Collaborative Explorations Jan 2007

Journal Of Mathematics And Science: Collaborative Explorations

Journal of Mathematics and Science: Collaborative Explorations

No abstract provided.


Classification Of Microarray Data To Predict Toxic Exposure, Tarek A. Seleem Jan 2007

Classification Of Microarray Data To Predict Toxic Exposure, Tarek A. Seleem

Browse all Theses and Dissertations

This thesis presents a software system for the analysis of microarray data. Microarrays are a relatively new technology that can be used to examine the state of the genome of an organism at some instant in time. The challenge is the amount of natural variation in biological systems limits our ability to identify specific genes that may be sensitive to changes in an organism's physiology or its environment. The analysis software consists of three modules. The first module filters microarray data to reduce the complexity of the problem. The second module selects subsets of genes for evaluation using a genetic …


Biogeochemical Processes And Seasonal Effects In Flow-Through Mesocosm Reactors Simulating Constructed Wetlands, Sarah J. Tritschler Jan 2007

Biogeochemical Processes And Seasonal Effects In Flow-Through Mesocosm Reactors Simulating Constructed Wetlands, Sarah J. Tritschler

Browse all Theses and Dissertations

Due to their distinctive environments, constructed wetlands are utilized to remediate groundwater that has been contaminated with chlorinated ethenes (i.e. perchloroethene) and other such contaminants. This research focuses on vertical flow mesocosm reactors housed in a greenhouse at Wright State University, which simulate a constructed wetland on Wright-Patterson Air Force Base. These reactors were studied to investigate the effects of vegetation and seasonal changes on the redox parameters present. Water samples were collected from six different reactors from late September/early October 2006 until August 2007. The reactors were sampled three days in a row and this sampling was done once …


Investigation Of The Reflective Properties Of A Left-Handed Metamaterial, Amanda Durham Jan 2007

Investigation Of The Reflective Properties Of A Left-Handed Metamaterial, Amanda Durham

Browse all Theses and Dissertations

The purpose of this project is to investigate the reflective properties of a left-handed metamaterial (LHM) through the use of a finite element analysis software called FEMLAB. In the 1960's, V. Veselago theorized that a material with negative permeability and negative permittivity has a negative index of refraction. In 2000, such a metamaterial was built and demonstrated at microwave frequencies. Previous work had focused on the transmission properties of the metamaterial. In our work, the reflected wave was examined for a LHM subject to an incident transverse electric wave. The different generalizations, first proposed by Veselago, of the Fresnel and …


The Electroanalytical Performance Of Sonogel Carbon Titanium (Iv) Oxide Electrodes Versus Conducting Polymer Electrodes In The Electrochemical Detection Of Biological Molecules, Jelynn A. Stinson Jan 2007

The Electroanalytical Performance Of Sonogel Carbon Titanium (Iv) Oxide Electrodes Versus Conducting Polymer Electrodes In The Electrochemical Detection Of Biological Molecules, Jelynn A. Stinson

Browse all Theses and Dissertations

The electrochemical performance of a newly developed sonogel carbon titanium (IV) oxide (SGC/TiO2 ) electrode against poly(3-methylthiophene) (P3MT) and poly(2,2'-bithiophene) (PBTP) modified electrodes in the electrochemical detection of biological molecules is reported. The stability of the Titanium (IV) Oxide coating on the sonogel carbon electrode was shown to be greater than the P3MT coating on the conventional size glassy carbon electrode. After 10 consecutive scans, there was a 21% loss of the initial signal at the P3MT modified electrode and a 5% loss of the initial signal at the SGC/TiO2 electrode. The influence of NAD+ on NADH response was tested. …


Laser Initiated Chain Reactions: The Kinetics Of The Chlorine/Cyclohexane/Oxygen Chain System, Robert Alan Forlines Jan 2007

Laser Initiated Chain Reactions: The Kinetics Of The Chlorine/Cyclohexane/Oxygen Chain System, Robert Alan Forlines

Browse all Theses and Dissertations

The combination of laser photolysis with infrared chemiluminescence detection has proven an effective technique for determining the propagation rate coefficients of halogen + RH chain reactions. This thesis will extend the technique to cyclic alkanes by determining the propagation rate coefficients of the Cl2/ cyclohexane chain system as well as the rate coefficient for the primary chain termination mechanism, R + O2 → RO2. The following reaction scheme is supported by the kinetic analysis: Cl2 → 2Cl Laser Photolysis Cl + RH → HCl(v) + R First Propagation Step (k1) R + …


On The Cover Jan 2007

On The Cover

Sci-Tech News

No abstract provided.