Physical Sciences and Mathematics Commons^™

Material Damage From Ultrashort Bursts Of Light, Jeremy Gulley

Jeremy R. Gulley

No abstract is currently available.

All-Optical Suppression Of Relativistic Self-Focusing Of Laser Beams In Plasmas, Serguei Y. Kalmykov, Sunghwan A. Yi, Gennady Shvets

Serge Youri Kalmykov

It is demonstrated that a catastrophic relativistic self-focusing (RSF) of a high-power laser pulse can be prevented all-optically by a second, much weaker, copropagating pulse. RSF suppression occurs when the difference frequency of the pulses slightly exceeds the electron plasma frequency. The mutual defocusing is caused by the three-dimensional electron density perturbation driven by the laser beat wave slightly above the plasma resonance. A bi-envelope model describing the early stage of the mutual defocusing is derived and analyzed. Later stages, characterized by the presence of a strong electromagnetic cascade, are investigated numerically. Stable propagation of the laser pulse with weakly …

Magnetic Field Measurements Of O Stars With Fors 1 At The Vlt., S. Hubrig, M. Schöller, R. S. Schnerr, J. F. González, R. Ignace, H. F. Henrichs

Richard Ignace

Context.The presence of magnetic fields in O-type stars has been suspected for a long time. The discovery of these fields would explain a wide range of well documented enigmatic phenomena in massive stars, in particular cyclical wind variability, Hα emission variations, chemical peculiarity, narrow X-ray emission lines, and non-thermal radio/X-ray emission.
Aims.To investigate the incidence of magnetic fields in O stars, we acquired 38 new spectropolarimetric observations with FORS 1 (FOcal Reducer low dispersion Spectrograph) mounted on the 8-m Kueyen telescope of the VLT.
Methods.Spectropolarimetric observations were obtained at different phases for a sample of 13 O …

Precise Measurement Of The Top-Quark Mass From Lepton + Jets Events, V. M. Abazov, Kenneth A. Bloom, D0 Collaboration

Kenneth Bloom Publications

We measure the mass of the top quark using top-quark pair candidate events in the lepton + jets channel from data corresponding to 1 fb^-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider. We use a likelihood technique that reduces the jet energy scale uncertainty by combining an in situ jet energy calibration with the independent constraint on the jet energy scale (JES) from the calibration derived using photon þ jets and dijet samples. We find the mass of the top quark to be 171.5 ± 1.8(stat) + JES) ± 1.1(syst) GeV.

Restoration Of Dredged Canals In Wetlands: A Comparison Of Methods, Joseph Baustian, R. Eugene Turner, Nancy F. Walters, David P. Muth

Faculty Publications

A comparison of two methods for restoring dredged canals to wetlands was examined at the Jean Lafitte National Historical Park and Preserve’s Barataria Preserve Unit near New Orleans, LA. Both northern and southern canals had the remnant dredged spoil material returned to the canal, but the southern canal had additional sediment pumped in from a nearby lake. The water depth in the southern canal shallowed significantly from 1.2 to 0.4 m following backfilling and sediment addition, while the depth of the northern canal (which received no additional sediment) remained unchanged following backfilling. Neither site had complete soil restoration, but the …

Measurement Of The Polarization Of The Ү(1S) And Ү(2S) States In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, D0 Collaboration

Kenneth Bloom Publications

We present a study of the polarization of the Ү(1S) and Ү(2S) states using a 1.3 fb^-1 data sample collected by the D0 experiment in 2002–2006 during run II of the Fermilab Tevatron Collider. We measure the polarization parameter α = (σ_T - 2σ_L), where σ_T and σ_L are the transversely and longitudinally polarized components of the production cross section, as a function of the transverse momentum (p_T^Ү) for the Ү(1S) and Ү(2S). Significant p_T^Ү-dependent longitudinal polarization is observed …

A Review Of Mobile-Based Initiatives Across College, Daniel Okunbor, Retta Guy

Math and Computer Science Faculty Working Papers

The information era in which we currently live is changing the culture of education. The use of information technologies has resulted in new opportunities that are rapidly evolving to include mobile learning. Keegan (2002) characterizes this evolution of distance learning as a shift from d-learning (distance) to e-learning (electronic) to m-learning (mobile) learning.

Mobile, wireless, and handheld technologies are being used to re-enact approaches and solutions to teaching and learning used in traditional and web-based formats. The goal of mobile learning is to provide opportunities for students to interact through computer-supported learning environments from mobile terminals with low speed wireless …

2008 Scholars And Artists Bibliography, Rajshehkar G. Javalgi Dr., Michael Schwartz Library, Cleveland State University, Friends Of The Michael Schwartz Library

Scholars and Artists Bibliographies

This bibliography was created for the annual Friends of the Michael Schwartz Library Scholars and Artists Reception, recognizing scholarly and creative achievements of Cleveland State University faculty, staff and emeriti. Dr. Rajshekhar Javalgi was the guest speaker.

Plurality Of Principal Angles For A Given Pseudo-Brewster Angle When Polarized Light Is Reflected At A Dielectric-Conductor Interface, R. M.A. Azzam, A. Alsamman

Electrical Engineering Faculty Publications

The pseudo-Brewster angle ϕpB of minimum reflectance for p-polarized light and the principal angle ϕ¯ at which incident linearly polarized light of the proper azimuth is reflected circularly polarized are considered as functions of the complex relative dielectric function ε of a dielectric–conductor interface over the entire complex ε plane. In particular, the spread of ϕ¯for a given ϕpB is determined, and the maximum difference (ϕ¯−ϕpB)max is obtained as a function of ϕpB . The maximum difference (ϕ¯−ϕpB)max approaches 45° and 0 in the limit as ϕpB→0 and 90°, respectively. ForϕpB<22.666° , multiple principal angles ϕ¯i , i=1,2,3 , appear for each ε in a subdomain of fractional optical constants. …

Halothiobacillus Neapolitanus Carboxysomes Sequester Heterologous And Chimeric Rubisco Species, Balaraj B. Menon, Zhicheng Dou, Sabine Heinhorst, Jessup M. Shively, Gordon C. Cannon

Faculty Publications

Background: The carboxysome is a bacterial microcompartment that consists of a polyhedral protein shell filled with ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), the enzyme that catalyzes the first step of CO(2) fixation via the Calvin-Benson-Bassham cycle. Methodology/Principal Findings: To analyze the role of RubisCO in carboxysome biogenesis in vivo we have created a series of Halothiobacillus neapolitanus RubisCO mutants. We identified the large subunit of the enzyme as an important determinant for its sequestration into alpha-carboxysomes and found that the carboxysomes of H. neapolitanus readily incorporate chimeric and heterologous RubisCO species. Intriguingly, a mutant lacking carboxysomal RubisCO assembles empty carboxysome shells of …

Temperature Dependence Investigation Of Dissipation Processes In Strongly Anisotropic High-Temperature Superconductors Of Bi-Pb-Sr-Ca-Cu-O System Synthesized Using Solar Energy, J Chigvinadze, Juana Acrivos, S. Ashimov, D. Gulamova, T. Machaidze, D Uskenbaev

Faculty Publications, Chemistry

The investigation of temperature dependence of damping and period of vibrations of HTSC superconductive cylinder of Bi-Pb-Sr-Ca-Cu-O system suspended by a thin elastic thread and performing axial-torsional vibrations in a magnetic field at temperatures above the critical one for the main phase Tc=107 K were carried out. It was observed some "chaos" temperature region in the temperature interval 107-138 K, where it is seen separate ripples of dissipation and oscillation frequency. It is assumed that the "chaos" region could point to a possibility of existence of other magnetic and more high-temperature phases as single islands in a normal materials matrix.

Dry Valleys Late Holocene Climate Variability, Karl J. Kreutz, Paul Andrew Mayewski

University of Maine Office of Research Administration: Grant Reports

This award supports a project to collect and develop high-resolution ice core records from the Dry Valleys region of Antarctica, and provide interpretations of interannual to decadal-scale climate variability during the last 2000 years (late Holocene). The project will test hypotheses related to ocean/atmosphere teleconnections (e.g., El Nino Southern Oscillation, Antarctic Oscillation) that may be responsible for major late Holocene climate events such as the Little Ice Age in the Southern Hemisphere. Conceptual and quantitative models of these processes in the Dry Valleys during the late Holocene are critical for understanding recent climate changes, and represent the main scientific merit …

Calibrating Parametric Subject-Specific Risk Estimation, Tianxi Cai, Lu Tian, Hajime Uno, Scott D. Solomon, L. J. Wei

Harvard University Biostatistics Working Paper Series

No abstract provided.

Queen's Domination Using Border Squares And (A,B)-Restricted Domination, Anne Sinko, Peter J. Slater

Mathematics Faculty Publications

In this paper we introduce a variant on the long studied, highly entertaining, and very difficult problem of determining the domination number of the queen's chessboard graph, that is, determining how few queens are needed to protect all of the squares of a k by k chessboard. Motivated by the problem of minimum redundance domination, we consider the problem of determining how few queens restricted to squares on the border can be used to protect the entire chessboard. We give exact values of "border-queens" required for the k by k chessboard when 1≤k≤13. For the general case, we …

Contributions To Random Energy Models., Nabin Kumar Jana Dr.

Doctoral Theses

In this introductory chapter, we begin with a brief description of spin glasses in section 1. We are not physicists. The purpose of this section is to trace the history of the models. Section 2 gives a brief summary of the thesis and section 3 recalls certain known facts which will be used later in the thesis.Origin of the problem The models considered in this thesis have their origin in spin glass theory. Roughly, spin glass is a glassy state in a spin system or a disordered material exhibiting high magnetic frustration. The origin of this behavior can be either …

Usu’S Rayleigh-Scatter Lidar, Vincent B. Wickwar

Presentations

No abstract provided.

Controlling The Transmitted Field Into A Cylindrical Cloak's Hidden Region, Jeffrey S. Mcguirk, Peter J. Collins

Faculty Publications

Constitutive parameters for simplified cylindrical cloaks have been developed such that ε_zµ_θ and ε_zµ_r match those of the ideal cylindrical cloak. Although they are not perfect, simplified cylindrical cloaks have been shown to inherit many of the power-bending properties of the ideal cloak. However, energy is transmitted into simplified cloaks' hidden regions. Here, we develop a constraint equation that can be used to determine how closely field behavior within the simplified cylindrical cloak matches that of the ideal cloak. The deviation from this controlling equation can be reduced by controlling the cloak's parameter value, …

Extreme-Ultraviolet Polarimeter Utilizing Laser-Generated High-Order Harmonics, Nicole Brimhall, Matthew Turner, Nicholas Herrick, David D. Allred, R. Steven Turley, Michael Ware, Justin Peatross

Faculty Publications

We describe an extreme-ultraviolet (EUV) polarimeter that employs laser-generated high-order harmonics as the light source. The polarimeter is designed to characterize materials and thin films for use with EUV light. Laser high harmonics are highly directional with easily rotatable linear polarization, not typically available with other EUV sources. The harmonics have good wavelength coverage, potentially spanning the entire EUV from a few to a hundred nanometers. Our instrument is configured to measure reflectances from 14 to 30 nm and has ~180 spectral resolution (lambda/delta lambda). The reflection from a sample surface can be measured over a continuous range of incident …

Synthesis, Characterization And Reactivity Of Some Selected Organosulfur Oxo-Acids, Adenike Otoikhian

Dissertations and Theses

The two major metabolites after S-Oxygenation of dimethylthiourea (N, N'-dimethylaminoiminomethanesulfinic acid (DMAIMSA) and N, N'-dimethylamino iminomethanesulfonic acid (DMAIMSOA)) were synthesized. Structural analysis by X-ray crystallography shows that DMAIMSA and DMAIMSOA exist as zwitterionic species in their solid form, with a positive charge delocalized around an sp²-hybridized carbon center flanked by two nitrogen atoms.

Kinetics and mechanistic studies on the oxidation of DMAIMSA and DMAIMSOA by acidified iodate/iodine and bromate/bromine were studied. The results reveal that DMAIMSA, unlike DMAIMSOA, is highly reactive. DMAIMSOA is very inert and unreactive in low pH environments. The difference in reactivity is attributed to …

Exploration Of A Physical Picture For The Qcd Scalar Channel, Joseph Schechter, Amir H. Fariborz, Renata Jora

Physics - All Scholarship

A generalized linear sigma model is employed to study the quark structure of low lying scalar as well as pseudoscalar states. The model allows the possible mixing of quark anti-quark states with others made of two quarks and two antiquarks but no a priori assumption is made about the quark contents of the predicted physical states. Effects of SU(3) symmetry breaking are included. The lighter conventional pseudoscalars turn out to be primarily of two quark type whereas the lighter scalars have very large four quark admixtures.

Efficient Gene Delivery Vectors By Tuning The Surface Charge Density Of Amino Acid-Functionalized Gold Nanoparticles, Ps Ghosh, Ck Kim, G Han, Ns Forbes, Vm Rotello

Vincent Rotello

Gold colloids functionalized with amino acids provide a scaffold for effective DNA binding with subsequent condensation. Particles with lysine and lysine dendron functionality formed particularly compact complexes and provided highly efficient gene delivery without any observed cytotoxicity. Nanoparticles functionalized with first generation lysine dendrons (NP-LysG1) were approximately 28-fold superior to polylysine in reporter gene expression. These amino acid-based nanoparticles were responsive to intracellular glutathione levels, providing a tool for controlled release and concomitant expression of DNA.

Observation Of Zz Production In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, D0 Collaboration

Kenneth Bloom Publications

We present an observation for ZZ → ℓ⁺ ℓ^-ℓ‘⁺ℓ‘^- (ℓ, ℓ‘ = e or μ ) production in pp collisions at a center-of-mass energy of √s = 1.96 TeV. Using 1.7 fb^-1 of data collected by the D0 experiment at the Fermilab Tevatron Collider, we observe three candidate events with an expected background of 0.14^+0.03 _-0.02 events. The significance of this observation is 5.3 standard deviations. The combination of D0 results in this channel, as well as in ZZ → ℓ⁺ ℓ^-vv, yields a significance of 5.7 …

Observation Of Zz Production In Pp Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, D0 Collaboration

Kenneth Bloom Publications

We present an observation for ZZ → ℓ⁺ ℓ^-ℓ‘⁺ℓ‘^- (ℓ, ℓ‘ = e or μ ) production in pp collisions at a center-of-mass energy of √s = 1.96 TeV. Using 1.7 fb^-1 of data collected by the D0 experiment at the Fermilab Tevatron Collider, we observe three candidate events with an expected background of 0.14^+0.03 _-0.02 events. The significance of this observation is 5.3 standard deviations. The combination of D0 results in this channel, as well as in ZZ → ℓ⁺ ℓ^-vv, yields a significance of 5.7 …

The University As Your Partner: Adding Value To Conservation Initiatives, Margaret N. Rees, Public Lands Institute

Presentations (PLI)

The Public Lands Institute is dedicated to strengthening the national fabric that is essential for the protection, conservation, multiple use, and management of public lands

One With The Cosmos: A Short Tour Out Your Backdoor, Shane L. Larson

Public Talks

No abstract provided.

Forage Spokesman Information, Clayton Geralds, Brady Jarvis

Kentucky Grazing Conference

No abstract provided.

Supplementing Cattle On Pasture: When, What And How Much?, Roy Burris

Kentucky Grazing Conference

The biggest advantage of maintaining cattle in the southeast is our ability to grow forages. It is generally an economic advantage to make maximum use of our forage and then supplement only when needed to meet our production goals. Judicious use of extra nutrition to grazing cattle can allow us to meet an objective which was best stated by Hoveland in 1986:

“Our objective is to maintain pasture at the highest quality that the environment will allow and efficiently convert as much of the pasture as possible into saleable animal product.”

Fencing And Watering Systems: Simpler Is Better, Ralph Quillin

Kentucky Grazing Conference

Sustainability and Grazing Management have taken on a new importance in the Americana farm community. The key components of the sustainable approach, profitability, agronomic, social and ecological responsibility and quality of life are becoming obtainable goals for this and future farming generations.

Practical Grazing Management And Feed Strategies To Alleviate Fescue Toxicosis, Glen Aiken

Kentucky Grazing Conference

Tall fescue grown in Kentucky is productive and persistent and that is why the state has 5 million acres of the stuff! Fescue has tolerances to drought, low fertility, and overgrazing that are attributed to a fungal endophyte which infects most tall fescue plants. Unfortunately, these advantages of tall fescue that livestock producers appreciate are offset by reduced calving percentages and calf weight gains caused by consumption of ergot alkaloids produced by the endophyte. Ergot alkaloids affect the physiology of cattle to cause elevation in body temperature, reduced sweating, retention of winter hair coats and uncontrollable growth of summer hair …

Herbicide Options For Pasture Weed Control, Jonathan D. Green

Kentucky Grazing Conference

Weeds have become more evident and problematic in grazed pastures as forage and livestock production systems have intensified. As animals consume the more desirable and palatable plant species in pastures, weedy plants become more abundant. In particular, animals tend to avoid grazing plants which contain thorns, prickly spines, or are unpalatable making some pastures less productive. In fact, many of the more problematic plants observed in Kentucky’s grazed pastures possess these characteristics including thistles, spiny amaranth (spiny pigweed), horsenettle, common cocklebur, tall ironweed, and buttercups.