Physical Sciences and Mathematics Commons^™

On Torsion-Free Crawley Groups, Brendan Goldsmith, A. L. S. Corner, R. Gobel

Articles

The notion of a Crawley p-group is well known in Abelian group theory. In this present work, a corresponding concept is introduced for torsion-free groups. The principal result, which uses the set-theoretic notions of the diamond and Martin’s axiom, establishes an independence result for N1-free Crawley groups.

Lake Whitefish And Diporeia Spp. In The Great Lakes: An Overview, Thomas F. Nalepa, Lloyd C. Mohr, Bryan A. Henderson, Charles P. Madenjian, Philip J. Schneeberger

United States Department of Commerce: Staff Publications

Because of growing concern in the Great Lakes over declines in abundance and growth of lake whitefish (Coregonus clupeaformis) and declines in abundance of the benthic amphipod Diporeia spp., a workshop was held to examine past and current trends, to explore trophic links, and to discuss the latest research results and needs. The workshop was divided into sessions on the status of populations in each of the lakes, bioenergetics and trophic dynamics, and exploitation and management. Abundance, growth, and condition of whitefish populations in Lakes Superior and Erie are stable and within the range of historical means, but …

Preliminary Investigations For Causes Of The Disappearance Of Diporeia Spp. From Lake Ontario, Ronald Dermott, Mohiuddin Munawar, Robert Bonnell, Silvina Carou, Heather Niblock, Thomas F. Nalepa, Gretchen Messick

United States Department of Commerce: Staff Publications

The amphipod Diporeia spp. comprised 60-80% of the benthos in offshore Lake Ontario and was an important food for fish. In eastern Lake Ontario, Diporeia spp. began disappearing in 1993 just after the arrival of dreissenid mussels. We compared survival of Diporeia spp. and Hyalella azteca in sediments from areas where Diporeia spp. populations had vanished with survival in sediments still inhabited. Survival was also examined in the presence of zebra mussel (Dreissena polymorpha) pseudofeces, filtered water from mussel cultures, and added bacteria. The Microtox® test indicated that sediment pore water was not toxic. Sediments from sites with …

Recovery And Decline Of Lake Whitefish In U.S. Waters Of Eastern Lake Ontario, 1980-2001, Randall W. Owens, Robert O'Gorman, Thomas H. Eckert, Brian F. Lantry, Dawn E. Dittman

United States Department of Commerce: Staff Publications

The lake whitefish (Coregonus clupeaformis) was an important member of the native fish community and a valued commercial species in Lake Ontario. Lake whitefish were common in U.S. waters of the lake until 1965 and very abundant in Canadian waters through the early 1970s, although their numbers declined shortly thereafter. During 1975-1985, lake whitefish stocks remained depressed throughout the lake as a result of the combined effects of degraded water quality, overfishing, and predation. Rainbow smelt (Osmerus mordax) probably preyed on whitefish fry, and sea lamprey (Petromyzon marinus) preyed on adults. During 1985-1987, lake …

Changes In Lake Whitefish Diet In Lake Michigan, 1998-2001, Stephen A. Pothoven

United States Department of Commerce: Staff Publications

Lake whitefish (Coregonus clupeaformis) were collected for diet analysis from Michigan’s waters of Lake Michigan during 1998-2001. When the benthic amphipod Diporeia spp. was available, it was an important item in the diets of small (<430 mm) and large (>430 mm) lake whitefish. In southern Lake Michigan, the most-common prey consumed in the absence of Diporeia spp. included zebra mussels (Dreissena polymorpha), gastropods, chironomids, and Mysis relicta. In northern regions of the lake, alternative prey included chironomids, isopods, Bythotrephes, and fish. Following the decline of Diporeia spp. in southeastern Lake Michigan between 1998 and 2001, their contribution …

The Reflection Of Karst In The Online Mirror: A Survey Within Scientific Databases, 1960-2005, Lee J. Florea, Beth Fratesi, Todd A. Chavez

Todd A. Chavez

The field of cave and karst science is served by a literature that is dispersed across far-flung topical journals, government publications, and club newsletters. As part of an inter-institutional project to globalize karst information (KIP, the Karst Information Portal), the USF Library undertook a structured battery of literature searches to map the domain of karst literature. The study used 4,300 individual searches and four literature databases: GeoRef, BIOSIS, Anthropology Plus, and GPO Access. The searches were based on a list of 632 terms including 321 karst-related keywords culled from three leading encyclopedias and glossaries of cave and karst science. An …

Azip, Audio Compression System: Research On Audio Compression, Comparison Of Psychoacoustic Principles And Genetic Algorithms, Howard Chen

Theses Digitization Project

The purpose of this project is to investigate the differences between psychoacoustic principles and genetic algorithms (GA0). These will be discussed separately. The review will also compare the compression ratio and the quality of the decompressed files decoded by these two methods.

Stratigraphy And Geochronology Of The Early Miocene Volcanic Units In The Bigadiç Borate Basin, Western Turkey, Fuat Erkül, Cahi̇t Helvaci, Hasan Sözbi̇li̇r

Turkish Journal of Earth Sciences

Western Turkey has undergone an intense deformation which has given rise to two types of basins since the Late Oligocene: NE-trending and E-W-trending basins situated on the basement rocks of the Menderes Massif, the Sakarya Zone, the Lycian nappes and the Bornova Flysch Zone. One of the NE-trending basins, the Bigadiç borate basin, is located in the Bornova Flysch Zone - a 50-90-km-wide zone between the Sakarya Zone and the Menderes Massif. Lower Miocene successions are dominated by lacustrine, fluvial, evaporitic sedimentary rocks and numerous NE-trending volcanic centres which produced considerable amounts of lava and volcaniclastic detritus in the Bigadiç …

Photochemical Generation Of 2-Methoxy-2methylpropylidene And Its Rearrangement Pathways, Stanislav Presolski

Honors Theses

2-methoxy-2-methylpropylidene was photochemically generated from a non-nitrogenous precursor, 1a,9b-Dihydro-IH-cyclopropa[1]phenanthrene-l-etbane 2-methoxy-2-methyl, available in two steps from phenanthrene. Two competing rearrangement pathways were observed for the p-methoxy carbene, 1,2-methyl shift and C-H insertion, which had varying weights depending on the solvent used. Nevertheless, the C-H insertion was always predominant, contrary to the current understanding of B-substituted carbenes, which apparently needs revision. An attempt was also made to measure by LFP the rate constant of rearrangement and lifetime of the stabilized l-chloro-2-methoxy-2-metbylpropylidene.

Why Isn't Globalization As Good For People As Its Marketed Image Suggests It Is?, Filson H. Glanz

The University Dialogue

No abstract provided.

Transfer Of Essential Fatty Acids By Marine Plankton, Adriana J. Veloza

Dissertations, Theses, and Masters Projects

Long chain n-3 polyunsaturated fatty acids (LCn-3 PUFAs) such as EPA and DHA are important biomolecules regulating production in marine ecosystems. This study examined how the interaction at the phytoplankton-zooplankton interface affected the transfer of LCn-3 PUFAs to higher trophic levels. Heterotrophic dinoflagellates contained higher levels of EPA and DHA than their algal prey, suggesting heterotrophic dinoflagellates enhanced the nutritional value of poor quality algae and subsequent transfer to the next trophic level. Formation of EPA and DHA in the dinoflagellates appears to be achieved by the elongation and desaturation of shorter fatty acid chains rather than through de novo …

Designation Of The Southwest National Wildlife Refuge Complex As Wetlands Of International Importance Under Ramsar, Convention On Wetlands Of International Importance, Mitchell Ward Coffman

LSU Master's Theses

The historical loss and continued threat of loss of Louisiana wetlands is a major environmental concern for the United States and the world. In 1971, the Ramsar Convention, an international environmental treaty was ratified to specifically address conservation planning and land use management issues involving wetlands of the world. Ramsar provides an international designation award called, the Wetlands of International Importance List, which formally acknowledges globally important wetland landscapes. Ramsar outlines specific criterion nominated wetland sites must possess for consideration of this listing.

The Southwest Louisiana National Wildlife Refuge Complex is an excellent candidate for nomination to the Ramsar Convention …

Error Estimates For Stabilized Approximation Methods For Semigroups, Sarah Campbell Mcallister

LSU Doctoral Dissertations

In this work we analyze error estimates for rational approximation methods, and their stabilizations, for strongly continuous semigroups. Chapter 1 consists of a brief survey of time discretization methods for semigroups. In Chapter 2, we demonstrate a new method for obtaining convergent approximations in the absence of stability for strongly continuous semigroups with arbitrary initial data. In Section 2.2, we state the stabilization result in more general form and show that this method can be used to improve known error estimates by a magnitude of up to one half for smooth initial data. In Section 2.3, we give concrete examples …

Studies Of Zeolite Entrapped Ruthenium Polypyridine Complexes, Anwar A. Bhuiyan

Journal of the Arkansas Academy of Science

There is an intense interest in designing molecular systems which will absorb visible sunlight, initiate an electron transfer process, and ultimately convert the solar energy to useful chemical energy of fuels such as hydrogen produced from water. The zeolite-entrapped polypyridine complexes of divalent ruthenium hold promise as efficient photocatalysts for net charge separation and such efficiencies are further enhanced by organized incorporation of donor and acceptor components. This paper deals with the synthesis and spectroscopic investigation of zeolite-entrapped ruthenium polypyridine complexes which may be useful in the development of solar energy conversion schemes. The sensitizer molecules, such as Ru(bpy)3 2+ …

Quantification And Prediction Of Stream Dryness In The Interior Highlands, Justin M. Homan, Nicholas M. Girondo, Charles J. Gagen

Journal of the Arkansas Academy of Science

Although ecological studies have noted streams drying in the Interior Highlands, published measurements of streambed dryness are lacking. Clearly, stream drying has the potential to affect benthic macroinvertebrate and fish communities. In 2003, we initiated an assessment of streambed dryness for three streams in the Ouachita Mountains representative of the Central Hills, Ridges, and Valleys. In the following summer, we applied the approach to 15 similar size watersheds in three distinct ecoregions of the Interior Highlands: Ouachita Mountains-Athens Plateau, Ozark Highlands-Springfield Plateau, and Lower Boston Mountains. Repeated dryness measurements were recorded in each stream and correlated to nearby USGS stream …

Identifying The Factors Distinguishing Timber Sales On Industrial And Non-Industrial Private Forest Lands In Arkansas, Sayeed R. Mehmood, Prabudhda Dahal

Journal of the Arkansas Academy of Science

Although forests provide a wide variety of products and services, timber still continues to be the most valued forest product in the marketplace. More than two-third of the nation's forests are under private control, some are owned by industries (about 10%) while a much larger portion (about 59%) is owned by individuals. This study investigates the differences between timber sales offered by industrial and non-industrial ownerships. A test of means revealed that there is a significant difference between per hectare bid for these 2 types of sales. A logistic regression model was then estimated to identify important factors characterizing this …

Modification Of Ct Quality Assurance Phantom For Pet/Ct Alignment And Pet Resolution, Prashanth K. Nookala

LSU Master's Theses

Radiotherapy treatment planning utilizing PET and CT is rapidly gaining acceptance in oncology. A limiting factor of the dual modality is the PET/CT alignment. A small error in PET/CT alignment may result in giving large doses of radiation to healthy tissues as a result of poor treatment planning. For this purpose, regular quality assurance testing of PET/CT must be performed. Separate QA procedures and phantoms have been developed for the two different modalities. In particular, many existing phantoms cannot be used for both modalities, which is a requirement for evaluating PET/CT alignment. Our goal is to evaluate several existing phantom …

A Review Of Phytoplankton Composition Within Chesapeake Bay And Its Tidal Estuaries, Harold G. Marshall, Lubomira Burchardt, Richard Lacouture

Biological Sciences Faculty Publications

Based on a continuous 20-year data base ofmonthly sampling in Chesapeake Bay and tidal regions of its major tributaries, 1454 phytoplankton taxa have been identified in these waters. They represent a diverse assemblage of species with a dominant diatom flora throughout the year, in addition to large seasonal representation by chlorophytes, cyanobacteria, cryptophytes and dinoflagellates. Included among this flora were 34 potential harmful or toxin producing species. The phytoplankton compositions associated with the seasonal successional patterns are discussed, in addition to characterizing the dominant floral relationships, with comparison to early composition records within the Bay. Several of the present day …

Simplex Codes Over The Ring \Sum_{N=0}^Su^N F_2, Mohammed M. Al-Ashker

Turkish Journal of Mathematics

In this paper, we introduce simplex linear codes over the ring \sum_{n=0}^{n=s}u^n F_2 of types \alpha and \beta, where u^{s+1}=0. And we determine their properties. These codes are an extension and generalization of simplex codes over the ring Z_{2^s}.

Maximal Oscillatory Singular Integrals With Kernels In L Log L(S^{N-1}), Ahmad Al-Salman

Turkish Journal of Mathematics

In this paper, we study the L^p mapping properties of a certain class of maximal oscillatory singular integral operators. We establish the L^p boundedness of our operators provided that their kernels belong to the natural space L log ^+L(S^{n-1}). Our result substantially improves a previously known result. Moreover, the approach developed in this paper can be applied to handle more general maximal oscillatory singular integral operators.

On Rough Singular Integrals Along Surfaces On Product Domains, Ahmad Al-Salman, Ali A. Al-Jarrah

Turkish Journal of Mathematics

In this paper, we study a class of singular integrals along surfaces on product domains with kernels in L(log L)^2(S^{n-1} \times S^{m-1}). We formulate a general theorem concerning the L^p boundedness of these operators. As a consequence of this theorem we establish L^p estimates of several classes of operators whose L^p boundedness in the one parameter setting is known. The condition L(log L)^2(B^{n-1} \times S^{m-1}) is known to be an optimal size condition

On Linear The Homeomorphism Between Function Spaces C_P(X) And C_{P,A}(X) \Times C_P (A), Sabri̇ Bi̇rli̇k

Turkish Journal of Mathematics

In this paper, we investigate a linear homeomorphism between function spaces C_p(X) and C_{p,A}(X) \times C_p(A) , where X is a normal space and A is a neighborhood retraction of X.

On Space Of Parabolic Potentials Associated With The Singular Heat Operator, Si̇nem Sezer, İlham A. Ali̇ev

Turkish Journal of Mathematics

Anisotropic spaces L_{p,\gamma}^{\alpha} of parabolic Bessel potentials, associated with the singular heat operator I-\Delta_{\gamma}+ \frac{\partial}{\partial t}, where \Delta_{\gamma} = \sum\limits_{k=1}^n \frac{\partial ^{2}}{\partial x_{k}^{2}} + \frac{2\gamma }{x_n}. \frac{\partial}{\partial x_n}, are introduced, and making use of special wavelet-type transform, a characterization of these spaces is obtained.

Design, Simulation And Tests Of A Low-Cost Microstrip Patch Antenna Arrays For The Wireless Communication, Gonca Çakir, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Typical low-cost, low-weight microstrip base station antenna arrays with beam-scanning capabilities are taken into account. In downtowns of large cities like New York, Chicago, and in historical cities like Istanbul, where high buildings are separated by narrow but densely occupied streets, antenna arrays with approximately 20°-35° beam-widths are required to complete the cellular communication coverage. To meet this requirement, new antenna arrays are designed with 35° beam-widths and 60° electronic scanning capabilities. Their characteristics are investigated both numerically and experimentally. An FDTD-based antenna simulation package (M-PATCH) is prepared, tested on canonical structures and against the literature first, for verification and …

Regional Stratigraphy Of The Newcastle Formation (Lower Cretaceous) In Eastern Montana And Western North Dakota, Adam J. Ulishney

Theses and Dissertations

The Newcastle Formation (Lower Cretaceous) consists of sandstone with interbedded shale, siltstone, and mudstone facies. This work shows that the regional stratigraphy of the unit is detailed enough for the interpretation of its depositional history and environments in eastern Montana. This work also illustrates the possible lowstand position of the Western Interior Seaway along with probable source areas providing sediments into the study area.

A total of 3446 geophysical wireline logs were used to determine formation tops of the Greenhorn, Mowry, Newcastle, Skull Creek, and Inyan Kara Formations. The log character of the Newcastle Formation was also described for all …

Optical Wave Propagation In Discrete Waveguide Arrays, Jared Hudock

Electronic Theses and Dissertations

The propagation dynamics of light in optical waveguide arrays is characteristic of that encountered in discrete systems. As a result, it is possible to engineer the diffraction properties of such structures, which leads to the ability to control the flow of light in ways that are impossible in continuous media. In this work, a detailed theoretical investigation of both linear and nonlinear optical wave propagation in one- and two-dimensional waveguide lattices is presented. The ability to completely overcome the effects of discrete diffraction through the mutual trapping of two orthogonally polarized coherent beams interacting in Kerr nonlinear arrays of birefringent …

Utk Geography Newsletter 5 (2005), Department Of Geography

UTK Geography Newsletter

No abstract provided.

Symmetrically Generated Groups, Benny Nguyen

Theses Digitization Project

This thesis constructs several groups entirely by hand via their symmetric presentations. In particular, the technique of double coset enumeration is used to manually construct J₃ : 2, the automorphism group of the Janko group J₃, and represent every element of the group as a permutation of PSL₂ (16) : 4, on 120 letters, followed by a word of length at most 3.

The Backward Shift On HP, William T. Ross

Department of Math & Statistics Faculty Publications

In this semi-expository paper, we examine the backward shift operator

Bf := (f-f(0)/z

on the classical Hardy space H^p. Through there are many aspects of this operator worthy of study [20], we will focus on the description of its invariant subspaces by which we mean the closed linear manifolds Ɛ ⊂ H^p for which BƐ ⊂ Ɛ. When 1 < p < ∞, a seminal paper of Douglas, Shapiro, and Shields [8] describes these invariant subspaces by using the important concept of a pseudocontinuation developed earlier by Shapiro [26]. When p = 1, the description is the same [1] except that in the proof, one must be mindful of some technical considerations involving the functions of bounded mean oscillation.

Estimating Load-Sharing Properties In A Dynamic Reliability System, Paul H. Kvam, Edsel A. Peña

Department of Math & Statistics Faculty Publications

An estimator for the load-share parameters in an equal load-share model is derived based on observing k-component parallel systems of identical components that have a continuous distribution function F (˙) and failure rate r (˙). In an equal load-share model, after the first of k components fails, failure rates for the remaining components change from r (t) to γ1r (t), then to γ2r (t) after the next failure, and so on. On the basis of observations on n independent and identical systems, a semiparametric estimator of the component baseline …