Physical Sciences and Mathematics Commons^™

On The Stabilization And Regularization Of Rational Approximation Schemes For Semigroups, Simone Flory

LSU Doctoral Dissertations

In this work we discuss consistency, stability and convergence of rational approximation methods for strongly continuous semigroups on Banach spaces. The Lax-Chernoff theorem shows that in this setting consistency and stability assumptions are necessary to obtain strong uniform convergence of approximation methods. We investigate rational approximation methods for strongly continuous semigroups and their consistency properties, with special emphasis on A-stable methods and Padé-type approximations. In particular, we discuss the stability and convergence properties of these schemes, including the stability of the well-known and widely used Backward-Euler and Crank-Nicolson Schemes. Furthermore, we modify stabilization techniques developed by Hansbo, Larsson, Luskin, Rannacher, …

Artificial Peptides Containing Ca,A- Disubstituted Amino Acids: Synthesis, Conformational Studies, And Application As Β-Strand Mimics, Yanwen Fu

LSU Doctoral Dissertations

Short peptides containing C^α,α-dipropylglycine (Dpg) at alternating sequence positions were synthesized and examined for conformational behavior. Peptide assembly was performed using Fmoc-solid-phase chemistry where the coupling with PyAOP could be significantly enhanced at elevated temperature. Circular dichroism (CD) and NMR conformational studies revealed that incorporation of Dpg residues induced folded structures into peptides. It was observed that Dpg residues adopted helical conformation in a helix-promoting sequence. The resulting helical structure was comprised of consecutive β-turns whose structure was stabilized by salt bridge in aqueous solution. In this study, the preparation of sterically and polyfunctional C^α,α-disubstituted amino …

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 …

Bronx River Restoration: Report And Assessment, Teresa Crimmens

Student Theses 2001-2013

-

Game Ranching: Boon Or Bane?, Bruce Morrison

Nebraska Game and Parks Commission: Staff Research Publications

The title of today' s session is Game Ranching: Boon or Bane? What do we mean by game ranching? For today' s discussions, we will look at the raising of traditional wildlife species, both native and exotic, behind high-wire fences for economic return. Many years ago, this was considered a Texas problem and most state wildlife agencies did not pay much attention to the growing trend of fencing large acreages to hold wildlife captive. It was contrary to the traditional view of game management and many thought that it was just a passing fad. Today, there are thousands of captive …

Neutron Powder Diffraction Studies Of The La0.65Pb0.35Mno3 Perovskite, Camelia Borca, Shireen Adenwalla, Sy-Hwang Liou, Q.L. Xu, J. L. Robertson, Peter A. Dowben

Peter Dowben Publications

The structure of La_0.65Pb_0.35MnO₃ has been studied by neutron powder diffraction. From the temperature dependence of the lattice parameters, we observe that La_0.65Pb_0.35MnO₃ remains single phase in the temperature interval from 25 to 400 K, with a rhombohedral (R3c) structure. The collinear Mn spins suffer a thermally driven reorientation transition close to the Curie temperature, as obtained from powder samples (using neutron diffraction) and from thin films [using ferromagnetic resonance (FMR)]. The reorientation transition may indicate the presence of local Jahn–Teller (JT) lattice distortions, which are prevented from …

First Operational Brdf, Albedo Nadir Reflectance Products From Modis, Crystal B. Schaaf, Feng Gao, Alan H. Strahler, Wolfgang Lucht, Xiaowen Li, Trevor Tsang, Nicholas C. Strugnell, Xiaoyang Zhang, Yufang Jin, Jan-Peter Muller, Philip Lewis, Michael Barnsley, Paul Hobson, Mathias Disney, Gareth Roberts, Michael Dunderdale, Christopher Doll, Robert P. D’Entremont, Baoxin Hu, Shunlin Liang, Jeffrey L. Privette, David P. Roy

United States National Aeronautics and Space Administration: Publications

With the launch of NASA’s Terra satellite and the MODerate Resolution Imaging Spectroradiometer (MODIS), operational Bidirectional Reflectance Distribution Function (BRDF) and albedo products are now being made available to the scientific community. The MODIS BRDF/Albedo algorithm makes use of a semiempirical kernel-driven bidirectional reflectance model and multidate, multispectral data to provide global 1-km gridded and tiled products of the land surface every 16 days. These products include directional hemispherical albedo (black-sky albedo), bihemispherical albedo (white-sky albedo), Nadir BRDF-Adjusted surface Reflectances (NBAR), model parameters describing the BRDF, and extensive quality assurance information. The algorithm has been consistently producing albedo and NBAR …

Water Well And Spring Map Of The Somerset 30 X 60 Minute Quadrangle, Kentucky, Bart Davidson

Map and Chart--KGS

No abstract provided.

Mass-Loss And Magnetospheres: X-Rays From Hot Stars And Young Stellar Objects, M. Gagné, David H. Cohen, S. P. Owocki, A. Ud-Doula

Physics & Astronomy Faculty Works

High-resolution X-ray spectra of high-mass stars and low-mass T-Tauri stars obtained during the first year of the Chandra mission are providing important clues about the mechanisms which produce X-rays on very young stars. For zeta Puppis (O4 If) and zeta Ori (O9.5 I), the broad, blue-shifted line profiles, line ratios, and derived temperature distribution suggest that the X-rays are produced throughout the wind via instability-driven wind shocks. For some less luminous OB stars, like theta^1 Ori C (O7 V) and tau Sco (B0 V), the line profiles are symmetric and narrower. The presence of time-variable emission and very high-temperature lines …

Theoretical Investigation Of The Ground And Excited States Of Coumarin 151 And Coumarin 120, Robert J. Cave, Kieron Burke, Edward W. Castner Jr.

All HMC Faculty Publications and Research

We present calculations of various properties of the ground and excited states of Coumarins 151 and 120. These and related coumarins are important in investigating ultrafast solvation processes in liquids and complex solutions as well as being important acceptors in model electron-transfer systems. We calculate the following:  (1) the electronic excitation energies to several low-lying singlet states, (2) ground and excited-state dipole moments, (3) solvation effects on excitation energies, and (4) the properties of single Coumarin 151-water complexes. We test our Time-Dependent Density Functional Theory (TDDFT) calculations against CASSCF, CASPT2 (both single and multistate versions), CIS, and ZINDO. Using TDDFT, …

Multistate Effects In Calculations Of The Electronic Coupling Element For Electron Transfer Using The Generalized Mulliken−Hush Method, Michael Rust '01, Jason Lappe '00, Robert J. Cave

All HMC Faculty Publications and Research

A simple diagnostic is developed for the purpose of determining when a third state must be considered to calculate the electronic coupling element for a given pair of diabatic states within the context of the generalized Mulliken−Hush approach (Chem. Phys. Lett. 1996, 275, 15−19). The diagnostic is formulated on the basis of Löwdin partitioning theory. In addition, an effective 2-state GMH expression is derived for the coupling as it is modified by the presence of the third state. Results are presented for (i) a model system involving charge transfer from ethylene to methaniminium cation, (ii) a …

Structural Transition In (C60)N Clusters, W. Branz, N. Malinowski, Axel Enders, T. P. Martin

Axel Enders Publications

The structure of (C₆₀) _n clusters (n = 1– 150) was investigated by heating them to definite temperatures in a helium bath (heating cell) with subsequent characterization in a time-of-flight mass spectrometer. The intensity anomalies in the resulting mass spectra reflect particularly stable configurations that resisted evaporation. However, the set of enhanced peaks (magic numbers) turned out to be temperature dependent. Clusters heated to a moderate temperature of 490 K yielded mass spectra indicating the presence of icosahedral structures that can be characterized by a set of unusually strong peaks, namely n = 13, 19, 23, 26, …

Adsorbate And Thermally Induced Spin Reorientation Transition In Low-Temperature-Grown Fe/Cu(001), D. Peterka, Axel Enders, G. Haas, K. Kern

Axel Enders Publications

Adsorbate and thermally induced changes of the spin reorientation transition in Fe wedges grown at 140 K on Cu(001) substrates are investigated by the magneto-optical Kerr effect and Kerr microscopy. The adsorption of oxygen causes a complete reorientation of the easy axis of magnetization into the film plane. In contrast to that carbon monoxide decreases the critical thickness for the reorientation transition of the film by 0.7 monolayer down to 3.6 monolayers, while films thinner than 3.6 monolayers remain magnetized perpendicularly. These adsorbate-induced changes can be ascribed to a change in the surface magnetic anisotropy. Also annealing of the films …

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Effects Of Field Size And Landscape Composition On Grassland Birds In South-Central Iowa, David Joseph Horn, Rolf R. Koford, Malinda L. Braland

Journal of the Iowa Academy of Science: JIAS

Many species of grassland birds have been shown to avoid smaller fields. The avoidance of smaller fields, however, has not been consistently reported; avoidance may occur in one study, but not in another. To examine one possible reason for these inconsistencies, we examined how landscape composition influenced the relations between occurrence or abundance and field size. The study took place during the 1998 breeding season on 44 Conservation Reserve Program (CRP) fields located in Adair, Ringgold, and Union counties. The relations between occurrence, abundance, and field size were not influenced by landscape composition for any species.

Grasshopper Sparrow, Ammodramus savannarum, …

Factors Influencing The Occurrence Of Birds That Use Feeders In Iowa, David Joseph Horn, Steve E. Fairbairn, Richard J. Hollis

Journal of the Iowa Academy of Science: JIAS

Since its inception in 1984, data from the annual Iowa "Winter Bird Feeder Survey" have provided valuable information about birds that use feeders in Iowa such as spatial and temporal population trends. Using data from the 1988 and 1994 Surveys, we examined how the occurrence of bird species that use feeders was influenced by geographic location, the habitat surrounding a house, and the types of seeds offered at a house. Of the 23 species examined, the occurrence of 8 species was influenced by latitude, 22 species were influenced by the habitat surrounding the house, and 22 species were influenced by …

Inheritance Of Gray Leaf Spot Resistance In Corn, J. M. D. Crowley, A. R. Hallauer, C. A. Martinson

Journal of the Iowa Academy of Science: JIAS

Gray leaf spot disease, caused by Cercospora zeae-maydis Tehon and Daniels, has become a significant disease in Iowa corn (Zea mays L.) production. Incidence of gray leaf spot has increased with the increased use of conservation tillage practices. The inheritance of resistance to gray leaf spot was studied via use of generation mean analyses for five crosses and via use of 100 S₁ progenies developed from an F₂ population. Experiments were conducted at two locations that included either natural or artificial inoculation with C. zeae-maydis spores. Additive and dominance effects were significant in nearly all instances. Heritability for …

Fungi And Diseases Associated With Cultivated Switchgrass In Iowa, C. E. Gravert, G. P. Munkvold

Journal of the Iowa Academy of Science: JIAS

Switchgrass (Panicum virgatum L.) is a native perennial prairie grass that is now cultivated as a forage crop and a biomass crop for renewable energy. Biomass yields of switchgrass in southern Iowa have recently dropped significantly in some fields and the reduction has been attributed to disease. A disease survey was conducted in 1999 to assess the prevalence of major diseases in Chariton Valley switchgrass production. There were disease symptoms present on switchgrass plants in each field and thirteen fungal species were identified from leaf, stem, and root samples. Two pathogenic fungi, Tilletia maclaganii and Colletotrichum graminicola, were present in …

Book Review - Prairie Birds: Fragile Splendor In The Great Plains, Neil P. Bernstein

Journal of the Iowa Academy of Science: JIAS

Paul A. Johnsguard has established himself as one of the most prolific natural history writers in the recent past. Indeed, before I could finish reading Prairie Birds, the University of Kansas Press sent me The Nature of Nebraska, also by Johnsguard. These works follow closely after This Fragile Land, A Natural History of the Nebraska Sandhills (1995), which I favorably reviewed a few years ago, also about the Great Plains. It goes without saying, that there is a fair amount of overlap in these works, both in the subject matter and the illustrations. Rather than criticize the overlap among these …

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

The Unionid Mussels Of The Upper Iowa And Turkey River Watersheds, Jim Eckblad, Brett Ostby, Karis Tenneson

Journal of the Iowa Academy of Science: JIAS

The Iowa driftless region occupies an area of about 9,000 km² in the northeastern corner of Iowa and is drained by relatively old entrenched meandering streams. The Upper Iowa River and Turkey River are the largest of these streams. During the period from June, 1999 to October, 2000, a total of 193 sites were surveyed for mussels from the Upper Iowa River, the Turkey River, and their main tributaries. Surveys were conducted by hand using a 10 m bank-to-bank search at each site. Data analysis was facilitated using ArcView GIS. The presence of mussels was recorded at 75% of …

Index For The Journal Of The Iowa Academy Of Science Volume 109

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Insights Into The Mechanism For Orogen-Related Carbonate Remagnetization From Growth Of Authigenic Fe-Oxide: A Scanning Electron Microscopy And Rock Magnetic Study Of Devonian Carbonates From Northern Spain, Arlo Brandon Weil, Rob Van Der Woo

Geology Faculty Research and Scholarship

A rock magnetic and SEM study of Devonian carbonates from the Cantabria-Asturias Region, northern Spain, was undertaken to further our understanding of the pervasive remagnetization of carbonate rocks during the Late Paleozoic, and the mechanism by which these remagnetizations occur. These rocks contain three ancient Late Paleozoic magnetizations. The rock magnetic properties of mineral extracts were compared with those of whole rock chips and "nonmagnetic'' residue to deduce magnetic carrier(s) and grain sizes. Hysteresis measurements for rock chips show "typical'' wasp-waisted loops, whereas extract shows typical pseudosingle-domain-like (PSD) unrestricted loops. Within all sites, there is a noticeable contribution of superparamagnetic …

Dynamics Of A Granular Particle On A Rough Surface With A Staircase Profile, J. J. P. Veerman, F. V. Cunha Jr., G. L. Vasconcelos

Mathematics and Statistics Faculty Publications and Presentations

A simple model is presented for the motion of a grain down a rough inclined surface with a staircase profile. The model is an extension of an earlier model of ours where we now allow for bouncing, i.e., we consider a non-vanishing normal coefficient of restitution. It is shown that in parameter space there are three regions of interest: (i) a region of smaller inclinations where the orbits are always bounded (and we argue that the particle always stops); (ii) a transition region where halting, periodic and unbounded orbits co-exist; and (iii) a region of large inclinations where no halting …

Revised Bedrock Geology Of War Eagle Quadrangle, Benton County, Arkansas, Robert A. Sullivan, Stephen K. Boss

Journal of the Arkansas Academy of Science

A digital geologic map of War Eagle quadrangle (WEQ) was produced at the 1:24000 scale using the geographic information system (GIS) software ArcView® by digitizing geological contacts onto the United States Geological Survey (USGS) digital raster graphic (DRG). The geology of WEQ consists of sedimentary rocks of Ordovician (Cotter, Powell, and Everton Formations), Devonian (Clifty Formation and Chattanooga Shale), and Mississippian (St. Joe-Boone, Batesville, and Fayetteville Formations) systems. Impoundment of Beaver Lake in 1966 inundated most Ordovician rocks cropping out in WEQ, but all three formations were present in isolated outcrops along the present shoreline of the lake. The St. …

Beach Crawl Width As A Predictive Indicator Of Carapace Length In Loggerhead Sea Turtles (Caretta Caretta)., Dawn M. Miller

HCNSO Student Theses and Dissertations

Carapace lengths and widths of nesting loggerhead sea turtles (Caretta caretta) were measured at Pompano Beach and Fort Lauderdale, Florida to determine if plastron and/or track crawl widths were predictive of carapace size. Straight and curved carapace measurements were taken.

Plastron and track crawl width were measured at four points on each crawl: 1) emerging at the tide line; 2) mid-way to the nest; 3) mid-way returning to the surf; and 4) at the tide line returning to the surf. All four measurements were significantly different from each other (P < 0.005) along each crawl. Crawl width was the most variable factor in all comparisons.

Maximum straight carapace length correlated with emergent track …

A Comparison Of Aeration Methods And Diets For Larval Culture Of The Edible Sea Urchin, Tripneustes Ventricosus (Echinodermata: Echinoidea), Ray Wolcott

HCNSO Student Theses and Dissertations

Tripneustes ventricosus (Lamarck 1816), a major near-shore herbivore in the Atlantic and Caribbean, has been harvested for human consumption in the Caribbean for centuries (Lawrence 2001a, b), occasionally at rates that exceed sustainability (Smith & Berkes 1991), and is among the species having economic importance (Lawrence & Bazhin 1998). Tripneustes ventricosus has recently been observed on the forereef controlling macroalgal growth in the absence of Diadema antillarum (Woodley 1999, Aronson & Precht 2000, Haley & Solandt 2001).

Large-scale culturing has the potential to produce T. ventricosus in sufficient numbers to be used for: bioremediation of coral reef degradation, restocking of …

Coral Recruitment To Various Artificial Substrata, Miami Beach, Fl, Nicholas C. Straccione

HCNSO Student Theses and Dissertations

The City of Miami has placed 12 artificial reefs approximately 100m offshore in two parallel transects. The reason for this deployment was to tum a barren seabed into a productive environment for aquatic organisms. The reefs were placed close to the shoreline to allow easy access for snorkellers, divers, and fisherman. Three different types of reef materials were used in constructing the artificial reefs: boulders composed of limestone, concrete shaped as tetrahedrons, and concrete mixed with tire aggregate shaped as tetrahedrons. This study consisted of two separate assessments: I) a survey from two of each of the different reef types …