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2006

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Articles 5491 - 5520 of 5872

Full-Text Articles in Physical Sciences and Mathematics

In-Use Emission Measurements Of Snowmobiles And Snowcoaches In Yellowstone National Park, Gary A. Bishop, Daniel A. Burgard, Thomas R. Dalton, Donald H. Stedman Jan 2006

In-Use Emission Measurements Of Snowmobiles And Snowcoaches In Yellowstone National Park, Gary A. Bishop, Daniel A. Burgard, Thomas R. Dalton, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.


Self-Assembly And Its Inhibition In Bolaform Amphiphilic Dendrimers, Jirun Sun Jan 2006

Self-Assembly And Its Inhibition In Bolaform Amphiphilic Dendrimers, Jirun Sun

LSU Doctoral Dissertations

Self-assembly is scientifically interesting, technologically important, and sometimes life-threatening. A striking example: Alzheimer’s disease is caused by the self-assembly of the â-amyloid fragment of amyloid precursor protein. Such natural amphiphiles normally are very expensive and complicated to isolate. Synthetic mimics that are much cheaper and easier to prepare can facilitate the development of efficient characterization methods, even as they suggest new materials science applications. Two-directional arborols are synthetic bolaform amphiphilic dendrimers. They dissolve in hot water and form reversible gels at room temperature. Bundles of fibrils, which are made by self-assembly of arborols, are found in the gels. The properties …


Ab Initio Molecular Dynamics Simulations Of Methylaluminoxane (Mao) Synthesis By Hydrolysis Of Trimethylaluminum, Lacramioara Negureanu Jan 2006

Ab Initio Molecular Dynamics Simulations Of Methylaluminoxane (Mao) Synthesis By Hydrolysis Of Trimethylaluminum, Lacramioara Negureanu

LSU Doctoral Dissertations

MAO is the co-catalyst in the metallocene catalytic systems, which are widely used in single site olefin polymerization due to their high stereoselectivity. To date, the precise structure of MAO, the particular compound or compounds catalytically active in MAO, have eluded researchers. MAO, a white amorphous powder, is not a good sample for a direct spectroscopic characterization, and its NMR spectra are broad and almost featureless. Many structural models have been proposed but none are generally accepted. In the first part of this work the MAO formation mechanism was addressed. Molecular dynamics simulations at MP2 configuration interaction theory level have …


Pullbacks Of Crossed Modules And Cat^1- Commutative Algebras, Murat Alp Jan 2006

Pullbacks Of Crossed Modules And Cat^1- Commutative Algebras, Murat Alp

Turkish Journal of Mathematics

In this paper we first review the definitions of crossed module [10], pullback crossed module and cat^1-object in the category of commutative algebras. We then describe a certain pullback of cat^1- commutative algebras.


Population Genetic Structure Of Escolar (Lepidocybium Flavobrunneum) And A Molecular Phylogeny Of The Trichiuroidea, Kirsten Brendtro Jan 2006

Population Genetic Structure Of Escolar (Lepidocybium Flavobrunneum) And A Molecular Phylogeny Of The Trichiuroidea, Kirsten Brendtro

Dissertations, Theses, and Masters Projects

No abstract provided.


Chord Diagrams And Gauss Codes For Graphs, Thomas Fleming, Blake Mellor Jan 2006

Chord Diagrams And Gauss Codes For Graphs, Thomas Fleming, Blake Mellor

Mathematics, Statistics and Data Science Faculty Works

Chord diagrams on circles and their intersection graphs (also known as circle graphs) have been intensively studied, and have many applications to the study of knots and knot invariants, among others. However, chord diagrams on more general graphs have not been studied, and are potentially equally valuable in the study of spatial graphs. We will define chord diagrams for planar embeddings of planar graphs and their intersection graphs, and prove some basic results. Then, as an application, we will introduce Gauss codes for immersions of graphs in the plane and give algorithms to determine whether a particular crossing sequence is …


Intersection Graphs For String Links, Blake Mellor Jan 2006

Intersection Graphs For String Links, Blake Mellor

Mathematics, Statistics and Data Science Faculty Works

We extend the notion of intersection graphs for knots in the theory of finite type invariants to string links. We use our definition to develop weight systems for string links via the adjacency matrix of the intersection graph, and show that these weight systems are related to the weight systems induced by the Conway and Homfly polynomials.


Tree Diagrams For String Links, Blake Mellor Jan 2006

Tree Diagrams For String Links, Blake Mellor

Mathematics, Statistics and Data Science Faculty Works

In previous work, the author defined the intersection graph of a chord diagram associated with string links (as in the theory of finite type invariants). In this paper, we classify the trees which can be obtained as intersection graphs of string link diagrams.


Intrinsic Linking And Knotting Of Graphs In Arbitrary 3–Manifolds, Erica Flapan, Hugh Howards, Don Lawrence, Blake Mellor Jan 2006

Intrinsic Linking And Knotting Of Graphs In Arbitrary 3–Manifolds, Erica Flapan, Hugh Howards, Don Lawrence, Blake Mellor

Mathematics, Statistics and Data Science Faculty Works

We prove that a graph is intrinsically linked in an arbitrary 3–manifold MM if and only if it is intrinsically linked in S3. Also, assuming the Poincaré Conjecture, we prove that a graph is intrinsically knotted in M if and only if it is intrinsically knotted in S3.


Linked Exact Triples Of Triangulated Categories And A Calculus Of T-Structures, Michael Berg Jan 2006

Linked Exact Triples Of Triangulated Categories And A Calculus Of T-Structures, Michael Berg

Mathematics, Statistics and Data Science Faculty Works

We introduce a new formalism of exact triples of triangulated categories arranged in certain types of diagrams. We prove that these arrangements are well-behaved relative to the process of gluing and ungluing t-structures defined on the indicated categories and we connect our con. structs to· a problem (from number theory) involving derived categories. We also briefly address a possible connection with a result of R. Thomason.


The Influence Of Predation On The Nesting Ecology Of Diamondback Terrapins (Malaclemys Terrapin) In The Lower Chesapeake Bay, Victoria Ann Ruzicka Jan 2006

The Influence Of Predation On The Nesting Ecology Of Diamondback Terrapins (Malaclemys Terrapin) In The Lower Chesapeake Bay, Victoria Ann Ruzicka

Dissertations, Theses, and Masters Projects

No abstract provided.


Maldi-Tof Baseline Drift Removal Using Stochastic Bernstein Approximation, Joseph Kolibal, Daniel Howard Jan 2006

Maldi-Tof Baseline Drift Removal Using Stochastic Bernstein Approximation, Joseph Kolibal, Daniel Howard

Faculty Publications

Stochastic Bernstein (SB) approximation can tackle the problem of baseline drift correction of instrumentation data. This is demonstrated for spectral data: matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) data. Two SB schemes for removing the baseline drift are presented: iterative and direct. Following an explanation of the origin of the MALDI-TOF baseline drift that sheds light on the inherent difficulty of its removal by chemical means, SB baseline drift removal is illustrated for both proteomics and genomics MALDI-TOF data sets. SB is an elegant signal processing method to obtain a numerically straightforward baseline shift removal method as it includes a …


Winter 2006 Nova Southeastern University Farquhar College Of Arts And Sciences Student Catalog, Nova Southeastern University Jan 2006

Winter 2006 Nova Southeastern University Farquhar College Of Arts And Sciences Student Catalog, Nova Southeastern University

Undergraduate Programs Course Catalogs

No abstract provided.


Sea Turtle Conservation Program, Broward County, Fl 2006 Report, Curtis M. Burney, Stefanie Ouellette Jan 2006

Sea Turtle Conservation Program, Broward County, Fl 2006 Report, Curtis M. Burney, Stefanie Ouellette

Marine & Environmental Sciences Faculty Reports

Since 1978, the Broward County Environmental Protection Department (BCEPD) has provided for the conservation of endangered and threatened sea turtle species within its area of responsibility. Broward County is within the normal nesting areas of three species of sea turtles: the loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas) and the leatherback sea turtle (Dermochelys coriacea). The loggerhead is listed as a threatened species, while the green and leatherback are listed as endangered under the U.S. Endangered Species Act, 1973, and Chapter 370, F.S.

Since these statutes strictly forbid any disturbance …


Approaching The Singularity In Gowdy Universes, Bartlett Douglas Edmonds Jr. Jan 2006

Approaching The Singularity In Gowdy Universes, Bartlett Douglas Edmonds Jr.

Theses and Dissertations

It has been shown that the cosmic censorship conjecture holds for polarized Gowdy spacetimes. In the more general, unpolarized case, however, the question remains open. It is known that cylindrically symmetric dust can collapse to form a naked singularity. Since Gowdy universes comprise gravitational waves that are locally cylindrically symmetric, perhaps these waves can collapse onto a symmetry axis and create a naked singularity. It is known that in the case of cylindrical symmetry, event horizons will not form under gravitational collapse, so the formation of a singularity on the symmetry axis would be a violation of the cosmic censorship …


Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne Jan 2006

Silicon Oxide Nanoparticles Reveal The Origin Of Silicate Grains In Circumstellar Environments, Peneé Armaize Clayborne

Theses and Dissertations

The processes leading to the widespread presence of crystalline silicates throughout the galaxy and the origin of silicon nanoparticles thought to be responsible for the observed extended red emission in diffuse galactic background are still far from being understood. One of the most abundant oxygen bearing species in molecular astronomical regions is SiO. It has been conjectured that silicate formation probably proceeds via the agglomeration of these molecular species; however there are no studies to reveal the microscopic mechanism. We have used a synergistic approach combining experiments in molecular beams and first principles theoretical calculation to demonstrate that the passage …


Soft-Gluon Corrections In Hard-Scattering Processes Through Nnnlo, Nikolaos Kidonakis Jan 2006

Soft-Gluon Corrections In Hard-Scattering Processes Through Nnnlo, Nikolaos Kidonakis

Faculty Articles

I discuss soft-gluon corrections in hard-scattering processes and their resummation. I present master formulas for the expansion of the resummed cross section through NNNLO and discuss the significance of these corrections in a number of processes.


The Strength And Structure Of The Galactic Center Magnetic Field, Ted La Rosa, Steven N. Shore, T. Joseph W. Lazio, Namir E. Kassim Jan 2006

The Strength And Structure Of The Galactic Center Magnetic Field, Ted La Rosa, Steven N. Shore, T. Joseph W. Lazio, Namir E. Kassim

Faculty Articles

This paper summarizes recently obtained, strong evidence for a weak global field in the Galactic center (GC): the existence of a large-scale region of diffuse, low-frequency, nonthermal emission coincident with the central molecular zone. The overall energetics of this emission, considered along with constraints on GC cosmic ray energy density and diffusion, indicate clearly that the magnetic field pervading this region is ∼ 10 μG. For completeness, additional points on the orientation of the GC nonthermal filaments, rotation measures of extragalactic sources seen through the GC, and comparison with other normal spiral galaxies are also reviewed.


Dry Creek Long Term Watershed Study: Buffer Zone Performance As Viable Amphibian Habitat, Brooke L. Talley, Thomas Crisman Jan 2006

Dry Creek Long Term Watershed Study: Buffer Zone Performance As Viable Amphibian Habitat, Brooke L. Talley, Thomas Crisman

School of Geosciences Faculty and Staff Publications

As bioindicators, amphibians typically require both terrestrial and aquatic habitats to complete their life cycles. Pre- timber-harvest monitoring (December 2002 through September 2003) of salamander and frog (Hylidae) populations was conducted in four watersheds of Decatur County, GA. Post- timber-harvest monitoring (December 2003 through September 2004) continued in the same watersheds (two reference and two treatment watersheds). Coverboards were used to monitor adult salamanders, larval salamanders were surveyed with dipnet sweeps, and frogs were monitored with vertical PVC pipes. Six salamander species (Desmognathus apalachicolae, Eurycea cirrigera, E. guttolineata, Notophthalmus viridescens, Plethodon grobmani, and Pseudotriton ruber) and five frog species (Hyla …


Flux Of Organic Carbon In A Riverine Mangrove Wetland In The Florida Coastal Everglades, Melissa M. Romigh, Stephen E. Davis Iii, Victor H. Rivera-Monroy, Robert R. Twilley Jan 2006

Flux Of Organic Carbon In A Riverine Mangrove Wetland In The Florida Coastal Everglades, Melissa M. Romigh, Stephen E. Davis Iii, Victor H. Rivera-Monroy, Robert R. Twilley

FCE LTER Journal Articles

Short-term (daily) and seasonal variations in concentration and flux of dissolved organic carbon (DOC) were examined over 15 tidal cycles in a riverine mangrove wetland along Shark River, Florida in 2003. Due to the influence of seasonal rainfall and wind patterns on Shark River’s hydrology, samplings were made to include wet, dry and transitional (Norte) seasons. We used a flume extending from a tidal creek to a basin forest to measure vertical (vegetated soil/water column) and horizontal (mangrove forest/tidal creek) flux of DOC. We found significant (p < 0.05) variations in surface water temperature, salinity, conductivity, pH and mean concentration of DOC with season. Water temperature and salinity followed seasonal patterns of air temperature and rainfall, while mean DOC concentration was highest during the dry season (May), followed by the wet (October) and ‘Norte’ (December) seasons. This pattern of DOC concentration may be due to a combination of litter production and inundation pattern of the wetland. In contrast to daily (between tides) variation in DOC flux between the mangrove forest and tidal creek, daily variations of mean water quality were not significant. However, within-tide variation of DOC flux, dissolved oxygen content and salinity was observed. This indicated that the length of inundation and water source (freshwater vs. saltwater) variation across tidal cycles influenced water quality and DOC flux in the water column. Net DOC export was measured in October and December, suggesting the mangrove forest was a source of DOC to the adjacent tidal creek during these periods. Net annual export of DOC from the fringe mangrove to both the tidal creek and basin mangrove forest was 56 g C m−2 year−1. The seasonal pattern in our flux results indicates …


Applications Of Geometric Probability Techniques To The Probability Distribution Of Distances In A Layered Sphere, Duane Smalley Jan 2006

Applications Of Geometric Probability Techniques To The Probability Distribution Of Distances In A Layered Sphere, Duane Smalley

Theses & Honors Papers

Many of the most fundamental forces in nature are dependent of the relative distance between points. The applications of geometric probability techniques to the probability distribution of distances in a layered sphere was studied. Through the use of geometric probability techniques an analysis of a two layered sphere was performed. Using Overhauser’s method, the probability density function was determined for a layered sphere. The research compares the derived probability density function to a Monte Carlo simulation and found that the derived function agrees with the simulation. The program used to create the Monte Carlo simulation was modified from a program …


Structural And Forecasting Softwood Lumber Models With A Time Series Approach, Nianfu Song Jan 2006

Structural And Forecasting Softwood Lumber Models With A Time Series Approach, Nianfu Song

LSU Doctoral Dissertations

The development of cointegration theories and the presence of nonstationarity in time series raised serious concerns about possible spurious estimations in forest products models. Based on the results of Hsiao (1997a, 1997b), all the virtues of two-stage least square (2SLS) hold if there are sufficient cointegration relations. Stationary null and nonstationary null unit root tests and monthly seasonal unit root tests were applied to the time series used in this dissertation. Cointegration tests with exogenous variables were performed to justify the 2SLS. A regional error correction model (ECM) with four regional lumber supply and demand equations and a U.S.-Canada supply …


Synthesis And Anticancer Evaluation Of Some New Unsymmetrical 3,5-Diaryl-4h-1,2,4-Triazole Derivatives, Olcay Beki̇rcan, Bahi̇tti̇n Kahveci̇, Murat Küçük Jan 2006

Synthesis And Anticancer Evaluation Of Some New Unsymmetrical 3,5-Diaryl-4h-1,2,4-Triazole Derivatives, Olcay Beki̇rcan, Bahi̇tti̇n Kahveci̇, Murat Küçük

Turkish Journal of Chemistry

A series of 4-arylidenamino-4H-1,2,4-triazole derivatives (3-11) were synthesized from the treatment of 4-amino-4H-1,2,4-triazoles (2) with certain aldehydes. Compounds 3-11 were reduced with NaBH_4 to afford the corresponding 4-arylmethylenamino-4H-1,2,4-triazoles (12-20). Compounds 1-10 and 12-19 were characterized by elemental analyses and ^1H NMR, ^{13}C NMR, IR and UV spectral data. Compounds 11 and 20 were characterized by ^1H NMR, ^{13}C NMR, IR and mass spectral data. Compounds 14, 16, 17, and 18 were tested for anticancer activities. Compound 17, chosen for its higher anticancer activity in the preliminary tests with the cancer cell lines of MCF7, NCI-H460, and SF-268, exhibited remarkable anticancer …


The Synthesis Of 4-Phenoxyphenylglyoxime And 4,4'-Oxybis(Phenylglyoxime) And Their Complexes With Cu(Ii), Ni(Ii) And Co(Ii), Ahmet Coşkun Jan 2006

The Synthesis Of 4-Phenoxyphenylglyoxime And 4,4'-Oxybis(Phenylglyoxime) And Their Complexes With Cu(Ii), Ni(Ii) And Co(Ii), Ahmet Coşkun

Turkish Journal of Chemistry

4-Acetyldiphenyl ether and 4,4'-diacetyldiphenyl ether were synthesized from diphenyl ether and acetyl chloride in the presence of AlCl_3 used as catalyst. Subsequently, their keto oxime and glyoxime derivatives were prepared. The metal complexes of the glyoximes such as Cu(II), Ni(II) and Co(II) were also prepared. The structures of these ligands and their complexes were identified by FT-IR, ^1H NMR and ^{13}C NMR spectral data, elemental analysis and magnetic measurements.


Three-Photon Absorption Process In Organic Dyes Enhanced By Surface Plasmon Resonance, Ion Cohanoschi Jan 2006

Three-Photon Absorption Process In Organic Dyes Enhanced By Surface Plasmon Resonance, Ion Cohanoschi

Electronic Theses and Dissertations

Multi-photon absorption processes have received significant attention from the scientific community during the last decade, mainly because of their potential applications in optical limiting, data storage and biomedical fields. Perhaps, one of the most investigated processes studied so far has been two-photon absorption (2PA). These investigations have resulted in successful applications in all the fields mentioned above. However, 2PA present some limitations in the biomedical field when pumping at typical 2PA wavelengths. In order to overcome these limitations, three-photon absorption (3PA) process has been proposed. However, 3PA in organic molecules has a disadvantage, typical values of σ3' are small (10-81 …


On The Use Of Variable Coherence In Inverse Scattering Problems, Erwan Baleine Jan 2006

On The Use Of Variable Coherence In Inverse Scattering Problems, Erwan Baleine

Electronic Theses and Dissertations

Even though most of the properties of optical fields, such as wavelength, polarization, wavefront curvature or angular spectrum, have been commonly manipulated in a variety of remote sensing procedures, controlling the degree of coherence of light did not find wide applications until recently. Since the emergence of optical coherence tomography, a growing number of scattering techniques have relied on temporal coherence gating which provides efficient target selectivity in a way achieved only by bulky short pulse measurements. The spatial counterpart of temporal coherence, however, has barely been exploited in sensing applications. This dissertation examines, in different scattering regimes, a variety …


Design And Optimization Of Nano-Optical Elements By Coupling Fabrication To Optical Behavior, Raymond Rumpf Jan 2006

Design And Optimization Of Nano-Optical Elements By Coupling Fabrication To Optical Behavior, Raymond Rumpf

Electronic Theses and Dissertations

Photonic crystals and nanophotonics have received a great deal of attention over the last decade, largely due to improved numerical modeling and advances in fabrication technologies. To this day, fabrication and optical behavior remain decoupled during the design phase and numerous assumptions are made about "perfect" geometry. As research moves from theory to real devices, predicting device behavior based on realistic geometry becomes critical. In this dissertation, a set of numerical tools was developed to model micro and nano fabrication processes. They were combined with equally capable tools to model optical performance of the simulated structures. Using these tools, it …


A Sparse Program Dependence Graph For Object Oriented Programming Languages, Keith Garfield Jan 2006

A Sparse Program Dependence Graph For Object Oriented Programming Languages, Keith Garfield

Electronic Theses and Dissertations

The Program Dependence Graph (PDG) has achieved widespread acceptance as a useful tool for software engineering, program analysis, and automated compiler optimizations. This thesis presents the Sparse Object Oriented Program Dependence Graph (SOOPDG), a formalism that contains elements of traditional PDG's adapted to compactly represent programs written in object-oriented languages such as Java. This formalism is called sparse because, in contrast to other OO and Java-specific adaptations of PDG's, it introduces few node types and no new edge types beyond those used in traditional dependence-based representations. This results in correct program representations using smaller graph structures and simpler semantics when …


Polarimetry Of Random Fields, Jeremy Ellis Jan 2006

Polarimetry Of Random Fields, Jeremy Ellis

Electronic Theses and Dissertations

On temporal, spatial and spectral scales which are small enough, all fields are fully polarized. In the optical regime, however, instantaneous fields can rarely be examined, and, instead, only average quantities are accessible. The study of polarimetry is concerned with both the description of electromagnetic fields and the characterization of media a field has interacted with. The polarimetric information is conventionally presented in terms of second order field correlations which are averaged over the ensemble of field realizations. Motivated by the deficiencies of classical polarimetry in dealing with specific practical situations, this dissertation expands the traditional polarimetric approaches to include …


Fast Response Liquid Crystal Devices, Yung-Hsun Wu Jan 2006

Fast Response Liquid Crystal Devices, Yung-Hsun Wu

Electronic Theses and Dissertations

Liquid crystal (LC) has been widely used for displays, spatial light modulators, variable optical attenuators (VOAs) and other tunable photonic devices. The response time of these devices is mainly determined by the employed liquid crystal material. How to obtain fast response for the LC devices is a fundamentally important and technically challenging task. In this dissertation, we investigate several methods to improve liquid crystal response time, for examples, using dual-frequency liquid crystals, polymer stabilized liquid crystals, and sheared polymer network liquid crystals. We discover a new class of material, denoted as sheared polymer network liquid crystal (SPNLC) which exhibits a …