Physical Sciences and Mathematics Commons^™

Magnetic And Transport Properties Of The V2– Vi3 Diluted Magnetic Semiconductor Sb2_Xmnxte3, Jeffrey Dyck, P. Svanda, P. Lostak, J. Horak, W. Chen, C. Uher

Jeffrey Dyck

We have measured electrical and magnetic properties of single crystals of Sb2_xMnxTe3 with x =0 – 0.045 at temperatures of 2 K to 300 K. Hall effect measurements indicate that each manganese atom donates approximately one hole to the valence band. The magnetic susceptibility is paramagnetic down to 2 K, and both Curie–Weiss and Brillouin analyses show that manganese substitutes for Sb and takes the Mn2+ state with S=5/2. Contrary to the case of III–V host matrices, manganese does not stimulate ferromagnetic order in the family of bulk layered V2– VI3 diluted magnetic semiconductors, at least in the range of …

Non-Steady-State Approach #11;To Steady-State Kinetics: #11;Case Study Of H2s Oxidation By Oxygen, Andrey N. Zagoruiko, Vladimir V. Mokrinskii

Andrey N Zagoruiko

Non-steady-state kinetic models may be used for treatment of steady-state kinetic data in case when algebraic elaboration of steady-state kinetic equations is impossible or complicated. The proposed approach includes numerical integration of time-dependent differential equations until achievement of steady-state, resulting in possibility to numerically obtain the rate values for separate reaction stages for given composition of reaction mixture. The obtained non-steady-state model may be then applied in simulation of catalyst pellets and catalyst beds in research and engineering purposes. The case study demonstrates application of such approach for steady-state kinetic description of complicated reaction system of H2S oxidation by oxygen. …

Light Propagation In Variable-Refractive-Index Materials With Liquid-Crystal-Infiltrated Microcavities, Bin Wang, Philip Bos, Charles D. Hoke

Philip J. Bos

A liquid-crystal-infiltrated microcavity structure is proposed as a variable-refractive-index material. It has the advantages over previously considered nanostructured materials of having a larger phase-angle change and lower driving voltage. Two-dimensional liquid-crystal director and finite-difference time-domain optical simulations are used to select liquid crystal material parameters and optimize the dimension of the microcavity structured material.

Constraints From Infrared Space Observatory Data On The Velocity Law And Clumpiness Of Wr 136., R. Ignace, M. F. Quigley, J. P. Cassinelli

Richard Ignace

Observations with the Infrared Space Observatory (ISO) SWS spectrometer are used to constrain the velocity law and wind clumping of the well-studied Wolf-Rayet (WR) star WR 136 (HD 192163) (WN6). Because the free-free continuum opacity in WR winds increases steadily with wavelength in the IR, each point in the continuous spectrum may be regarded as forming in a pseudo-photosphere of larger radius for longer wavelength. Using this idea in combination with an analysis of the Doppler-broadened widths of several \ion{He}{2} recombination lines, we can derive information about the velocity law and clumpiness of the stellar wind of WR 136. Adopting …

Comparison Between Analytical Probabilistic And Computer Simulation Models, Using Current Design Examples, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

Closed form analytical expressions have been developed to solve several basic problems related to the hydrologic design of storm water management facilities. The collection of these analytical expressions is referred to as the Analytical Probabilistic Storm Water Models (APSWM). APSWM can be used as an alternative to the design storm simulation models in the design and analysis of storm water management facilities. In this paper, a comparison is made between APSWM and design storm simulation models as applied to an actual design case. Conventional outputs such as runoff volume, peak discharge, and peak discharge from detention ponds are reviewed and …

Effect Of Parallel Velocity Shear On The Electrostatic Ion-Cyclotron Instability In Flamentary Current Channels, Erick Agrimson, Su-Hyun Kim, Nicola D'Angelo, Robert L. Merlino

Erick Agrimson

No abstract provided.

Ocena Funkcjonowania Instalacji Oczyszczania Gazów Odlotowych Z Procesu Grafityzacji Elektrod Węglowych W Sgl Carbon S.A. W Nowym Sączu, Marian Mazur, Robert Oleniacz, Marek Bogacki, Przemysław Szczygłowski

Robert Oleniacz

The paper presents a general analysis of the suitability of individual elements of the flue-gas treatment system used in SGL Carbon SA in Nowy Sacz (Poland) for the graphitization process carried out in new LWG furnaces (Castner type). The flue-gas treatment system consisted of two installations: catalytic afterburning and flue-gas desulfurization. The analysis of the suitability of various methods of flue-gas treatment was based primarily on the assessment of the effects of their application, including the reduction of concentrations of selected components in post-graphitizing gases. The work also summarizes the results of evaluation of the functioning of the whole flue-gas …

Xmm-Newton Observations Of The Nitrogen-Rich Wolf-Rayet Star Wr 1., R. Ignace, L. M. Oskinova, J. C. Brown

Richard Ignace

We present XMM-Newton results for the X-ray spectrum from the N-richWolf-Rayet (WR) star WR1. The EPIC instrument was used to obtain a medium-resolution spectrum. The following features characterize this spectrum: ( a) significant emission "bumps" appear that are coincident with the wavelengths of typical strong lines, such as MgXI, SiXIII, and SXV; (b) little emission is detected above 4 keV, in contrast to recent reports of a hard component in the stars WR 6 and WR 110 which are of similar subtype; and ( c) evidence for sulfur K-edge absorption at about 2.6 keV, which could only arise from absorption …

Breakdown Ofwave Diffusion In 2d Due To Loops, Matt M. Haney, Roel Snieder

Matthew M. Haney

The validity of the diffusion approximation for the intensity of multiply scattered waves is tested with numerical simulations in a strongly scattering 2D medium of finite extent. We show that the diffusion equation underestimates the intensity and attribute this to both the neglect of recurrent scattering paths and interference within diffusion theory. We present a theory to quantify this discrepancy based on counting all possible scattering paths between point scatterers. Interference phenomena, due to loop paths, are incorporated in a way similar to coherent backscattering.

Network Security Risk Assessment Modeling Tools For Critical Infrastructure Assessment, George H. Baker, Samuel Redwine, Joseph Blandino

George H Baker

The James Madison University (JMU) CIPP research team is developing Network Security Risk Assessment Modeling (NSRAM) tools that will enable the assessment of both cyber and physical infrastructure security risks. The effort is driven by the need to predict and compute the probability of adverse effects stemming from system attacks and malfunctions, to understand their consequences, and to improve existing systems to minimize these consequences.

The tools are targeted at systems supporting critical infrastructures varying from individual systems to organization-wide systems, to systems covering entire geographical regions. Early work emphasizes computing systems, but systems sharing the network nature of computing …

A Study Of Evolutionary Acceleration, Sanza Kazadi, Sparta Cheung, Cristal Ogletree, Shirley Kim, Catherine Lee, Andrew Min

Sanza Kazadi

Progressing Towards Governance For Sustainability At Parkfield School: Making Connections Through Dialogical Design, Sandra Wooltorton, Alan Kidd

Sandra Wooltorton

No abstract provided.

A Model For Shear Stress Sensing And Transmission In Vascular Endothelial Cells, Borbala Mazzag, John S. Tamaresis, Abdul Barakat

Borbala Mazzag

Femtosecond Phase-Coherent Two-Dimensional Spectroscopy, Peifang Tian, Dorine Keusters, Yoshifumi Suzaki, Warren S. Warren

Peifang Tian

Femtosecond phase-coherent two-dimensional (2D) spectroscopy has been experimentally demonstrated as the direct optical analog of 2D nuclear magnetic resonance. An acousto-optic pulse shaper created a collinear three-pulse sequence with well-controlled and variable interpulse delays and phases, which interacted with a model atomic system of rubidium vapor. The desired nonlinear polarization was selected by phase cycling (coadding experimental results obtained with different interpulse phases). This method may enhance our ability to probe the femtosecond structural dynamics of macromolecules.

Investigations Of Nonstandard, Mickens-Type, Finite-Difference Schemes For Singular Boundary Value Problems In Cylindrical Or Spherical Coordinates, Ron Buckmire

Ron Buckmire

No abstract provided.

The Zeeman Effect In The Sobolev Approximation: Applications To Spherical Stellar Winds., R. Ignace, K. G. Gayley

Richard Ignace

Modern spectropolarimeters are capable of detecting subkilogauss field strengths using the Zeeman effect in line profiles from the static photosphere, but supersonic Doppler broadening makes it more difficult to detect the Zeeman effect in the wind lines of hot stars. Nevertheless, the recent advances in observational capability motivate an assessment of the potential for detecting the magnetic fields threading such winds. We incorporate the weak-field longitudinal Zeeman effect in the Sobolev approximation to yield integral expressions for the flux of circularly polarized emission. To illustrate the results, two specific wind flows are considered: (i) spherical constant expansion with v(r) = …

The Conspicuous Absence Of X-Ray Emission From Carbon-Enriched Wolf-Rayet Stars., L. M. Oskinova, R. Ignace, W.-R. Hamann, A. M. T. Pollock, J. C. Brown

Richard Ignace

The carbon-rich WC5 star WR 114 was not detected during a 15.9 ksec XMM-Newton observation, implying an upper limit to the X-ray luminosity of L-X less than or similar to 2.5 x 10(30) erg s(-1) and to the X-ray to bolometric luminosity ratio of L-X/L(bo)l less than or similar to 4 x 10(-9). This confirms indications from earlier less sensitive measurements that there has been no convincing X-ray detection of any single WC star. This lack of detections is reinforced by XMM-Newton and Chandra observations of WC stars. Thus the conclusion has to be drawn that the stars with radiatively-driven …

Three-Dimensional Quantitative Structure−Property Relationship (3d-Qspr) Models For Prediction Of Thermodynamic Properties Of Polychlorinated Biphenyls (Pcbs): Enthalpies Of Fusion And Their Application To Estimates Of Enthalpies Of Sublimation And Aqueous Solubilities, Swati Puri, James S. Chickos, William J. Welsh

James Chickos

No abstract provided.

A New Class Of Entropy Estimators For Multi-Dimensional Densities, Erik G. Learned-Miller

Erik G Learned-Miller

We present a new class of estimators for approximating the entropy of multi-dimensional probability densities based on a sample of the density. These estimators extend the classic "m-spacing" estimators of Vasicek (1976) and others for estimating entropies of one-dimensional probability densities. Unlike plug-in estimators of entropy, which first estimate a probability density and then compute its entropy. our estimators avoid the difficult intermediate step of density estimation. For fixed dimension. the estimators an polynomial in the sample size. Similarities to consistent and asymptotically efficient one-dimensional estimators of entropy suggest that our estimators may sham these properties.

Development Of A Regression Model For Estimating The Effects Of Assumption Violations On Type I Error Rates In The Student's T Test: Implications For Practitioners, John Fraas, Isadore Newman, Rosalie J. Hall

John W. Fraas

No abstract provided.

Microlensing Of Circumstellar Envelopes Ii. Emission Lines From Radial And Azimuthal Flow During Fold Caustic Crossings., H. M. Bryce, R. Ignace, M. A. Hendry

Richard Ignace

This paper examines the line profile evolution due to bulk motion in circumstellar envelopes during microlensing fold caustic crossing events. These events have recently been shown to be a sensitive probe of stellar surface brightness profiles, thus providing a means - through both photometric and spectroscopic observations - to constrain and test stellar atmosphere models. Here it is demonstrated, through the examination of simplified line profiles, that spectroscopic studies of fold caustic crossings could also prove to be a powerful diagnostic of bulk motion in circumstellar envelopes.

Raman Spectroscopy Of Rhombohedral P4o10, Sean J. Gilliam, Scott Kirkby, Clifton N. Merrow, Daniel Zeroka, Ajit Banerjee, James O. Jensen

Scott J. Kirkby

Enabling Predictable Assembly, Scott A. Hissam, Gabriel A. Moreno, Judith Stafford, Kurt C. Wallnau

Gabriel A. Moreno

Demands for increased functionality, better quality, and faster time-to-market in software products continue to increase. Component-based development is the software industry’s response to these demands. The industry has developed technologies such as EJB and CORBA to assemble components that are created in isolation. Component technologies available today allow designers to plug components together, but do little to allow the developer to reason about how well they will play together. Predictable assembly focuses on issues related to assembling component-based systems that predictably meet their quality attribute requirements. This paper introduces prediction-enabled component technology (PECT) as a means of packaging predictable assembly …

Benefits Of A Comprehensive Undergraduate Teaching Assistant Program, Christopher Goff, Brigitte Lahme

Christopher Goff

Ordinary Least Squares Regression, Discriminant Analysis,And Logisitic Regression: Questions Researchers And Practioners Should Address When Selecting An Analytic Technique, John Fraas, Isadore Newman

John W. Fraas

No abstract provided.

Evolution Of Microstructure And Phase In Amorphous, Protocrystalline, And Microcrystalline Silicon Studied By Real Time Spectroscopic Ellipsometry, R. W. Collins, A. S. Ferlauto, G. M. Ferreira, Chi Chen, Joohyun Koh, R. J. Koval, Joshua M. Pearce, C. R. Wronski

Joshua M. Pearce

Heat Capacities Of Thiane Sulfones And Thiane Sulfoxide: Refining Of Cp Group Values For Organosulfur Compounds And Their Oxides, Marı́A Victoria Roux, Manuel Temprado, Pilar Jiménez, Ramón Guzmán-Mejı́A, Eusebio Juaristi, James S. Chickos

James Chickos

No abstract provided.

Enthalpies Of Vaporization Of Organic And Organometallic Compounds, 1880-2002, James S. Chickos, William E. Acree

James Chickos

No abstract provided.

Classifying Instantaneous Cognitive States From Fmri Data, Tom Mitchell, Rebecca Hutchinson, Marcel Just, Radu Niculescu, Francisco Pereira, Xuerui Wang

Marcel Adam Just

No abstract provided.

On Abel-Gontscharoff-Gould's Polynomials, Tian-Xiao He, Leetsch Hsu, Peter Shiue

Tian-Xiao He

In this paper a connective study of Gould’s annihilation coefficients and Abel-Gontscharoff polynomials is presented. It is shown that Gould’s annihilation coefficients and Abel-Gontscharoff polynomials are actually equivalent to each other under certain linear substitutions for the variables. Moreover, a pair of related expansion formulas involving Gontscharoff’s remainder and a new form of it are demonstrated, and also illustrated with several examples.