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Ensemble Density-Functional Approach To Charge-Spin Textures In Inhomogeneous Quantum Hall Systems, O. Heinonen, J. M. Kinaret, M. D. Johnson

Faculty Bibliography 1990s

We extend our ensemble density-functional approach to quantum Hall systems to include noncollinear spins to study charge-spin textures in inhomogeneous quantum Hall systems. We have studied the edge reconstruction in quantum dots at unit bulk filling factor and at 1/3 bulk filling factor as a function of the stiffness of an external confining potential. For soft enough edges, these systems reconstruct to a state in which the electron spins rotate gently as the edge is approached, with a nontrivial spin-charge texture at the edge of the system.

Nscat High-Resolution Surface Wind Measurements In Typhoon Violet, W. Linwood Jones, Vincent J. Cardone, Willard J. Pierson, Josko Zec, Larry P. Rice, Andrew Cox, Winfield B. Sylvester

Faculty Bibliography 1990s

NASA scatterometer (NSCAT) measurements of the western Pacific Supertyphoon Violet are presented for revolutions 478 and 485 that occurred in September 1996. A tropical cyclone planetary boundary layer numerical, model, which uses conventional meteorological and geostationary cloud data, is used to estimate the winds at 10-m elevation in the cyclone. These model winds are then compared with the winds inferred from the NSCAT backscatter data by means of a novel approach that allows a wind speed to be recovered from each individual backscatter cell. This spatial adaptive (wind vector) retrieval algorithm employs several unique steps. The backscatter values are first …

Synthesis And Current-Voltage Characterization Of Tin Dioxide Varistors, A. S. Kale, S. Seal, S. K. Date, P. N. Santhosh, R. N. Barve

Faculty Bibliography 1990s

An overview of the steady state electrical properties of tin dioxide varistors is presented. The varistors are manufactured in two ways: (1) a ceramic route by mixing and compaction of tin dioxide powder with various dopants and (2) a sol-gel method, where dopants are dispersed in their aqueous solutions. For a quantitative agreement with the experimental data,the electronic defect states in the bulk of the tin dioxide grains and at the grain boundary interfaces are studied. Scanning electron microscope and x-ray diffraction are employed to study the morphological and structural aspects of tin dioxide varistors. The effect of various sintering …

Numerical Modeling Of Thermal Refraction In Liquids In The Transient Regime, Dmitriy I. Kovsh, David J. Hagan, Eric W. Van Stryland

Faculty Bibliography 1990s

We present the results of modeling of nanosecond pulse propagation in optically absorbing liquid media. Acoustic and electromagnetic wave equations must be solved simultaneously to model refractive index changes due to thermal expansion and/or electrostriction, which are highly transient phenomena on a nanosecond time scale. Although we consider situations with cylindrical symmetry and where the paraxial approximation is valid, this is still a computation-intensive problem, as beam propagation through optically thick media must be modeled. We compare the full solution of the acoustic wave equation with the approximation of instantaneous expansion (steady-state solution) and hence determine the regimes of validity …

Partial Photoionization Cross Section And Resonance Structure Of Br, Dong Lin, H. P. Saha

Faculty Bibliography 1990s

The partial photoionization cross sections for the outer p subshell of the ground state of bromine are calculated in all available open channels as determined by LS coupling for photon energies from the P-3 to S-1 thresholds. The electron correlations which an important in this case have been taken into account using the multiconfiguration Hartree-Fock approximation for the hound and the continuum wave functions. The resonance structures between the P-3 and D-1 threshold and between the D-1 and S-1 threshold have been identified. In order to compare with experiment a frame transformation is applied to transform the LS dipole matrix …

Pulse Separation Control For Mode-Locked Far-Infrared P-Ge Lasers, A. V. Muravjov, R. C. Strijbos, C. J. Fredricksen, S. H. Withers, W. Trimble, S. G. Pavlov, V. N. Shastin, R. E. Peale

Faculty Bibliography 1990s

Active mode locking of the far-infrared p-Ge laser giving a train of 200 ps pulses is achieved via gain modulation by applying an rf electric field together with an additional bias at one end of the crystal parallel to the Voigt-configured magnetic field. Harmonic mode locking yields a train of pulse pairs with variable time separation from zero to half the roundtrip period, where pulse separation is electrically controlled by the external bias to the rf field.

Broad Band P-Ge Optical Amplifier Of Terahertz Radiation, A. V. Muravjov, S. H. Withers, S. G. Pavlov, V. N. Shastin, R. E. Peale

Faculty Bibliography 1990s

A solid state broad band amplifier of terahertz radiation (1.5-4 THz), based on intersubband transitions of hot holes in p-Ge is demonstrated. The gain is investigated as a function of applied magnetic and electric fields by transmission measurements using a laser system with two p-Ge active crystals, when one operates as an oscillator and one as an amplifier. A peak gain higher than usually reported for p-Ge lasers has been achieved using time separated excitation of the oscillator and amplifier. Distinct differences in gain dependence on applied fields are noted between low- and high-frequency modes of p-Ge laser operation.

Review: Esau's Tears: Modern Anti-Semitism And The Rise Of The Jews, Bruce F. Pauley

Faculty Bibliography 1990s

No abstract provided.

Statistical Estimation Of Locations Of Lightning Events, Marianna Pensky, John R. Cannon

Faculty Bibliography 1990s

In this paper, a statistical approach to the retrieval of lightning locations is proposed for the first time. This novel approach views the errors of the time measurements as random variables rather than unknown numbers. The unknown location (x, y, z) as well as the standard deviation a of the errors are treated as unknown parameters of a statistical model and are estimated using the maximum likelihood estimation (MLE) technique. On the basis of Monte Carlo simulations these statistical estimators are compared with the least squares estimators (LSE), as well as the solutions of the system of linear equations proposed …

Visible Light Emission From Dyes Excited By Simultaneous Absorption Of Two Different Frequency Beams Of Light, Alexandra Rapaport, Karine Ayrault, Eyitope St. Matthew-Daniel, Michael Bass

Faculty Bibliography 1990s

Emission of visible light by dyes in both liquid and polymer hosts is reported when excited by simultaneous absorption of infrared light from two different wavelength sources. By moving the intersection point of these two beams about within the volume of the dye-doped medium, one can create a true, real-time, three-dimensional display.

Processing And Characterization Of Nanometer Sized Copper Sulfide Particles, S. Seal, L. Bracho, S. Shukla, J. Morgiel

Faculty Bibliography 1990s

Nanomaterials have attracted considerable, attention in modern-day technology. In this article, sulfide nanoparticles of industrial interest are formed by the sol-gel process using metal chloride precursors dissolved in a mixture of silica gel and organic cellulose network followed by a chemical reaction with hydrogen sulfide gas. Particles are then heated in a vacuum oven. While scanning and transmission electron microscopy are used to study their morphology and structure in the nanometer scale, x-ray photoelectron spectroscopy is employed to understand the bonding chemistry and the stoichiometry of the sulfide particles as a function of H2S exposure and heat treatment. The results …

Role Of Surface Chemistry On The Nature Of Passive Oxide Film Growth On Fe-Cr (Low And High) Steels At High Temperatures, S. Seal, R. Nardelli, A. Kale, V. Desai, E. Armacanqui

Faculty Bibliography 1990s

High temperature materials degradation or protection of Fe-Cr alloys are often related to the nature of their oxide scale formation. Breakdown of passive oxide films lead to localized corrosion. Various alloying elements are often incorporated in these alloys to prevent high temperature oxidation. The addition of selected alloying elements is cumbersome and not always cost effective. In this article, we investigate the role of rare earth oxide coatings on high temperature corrosion prevention of both low and high Cr steel. An in situ high temperature oxidation setup has been built to study the oxidation kinetics of both coated and uncoated …

Magnetohydrodynamic Boundary Layer On A Flat Plate: Further Analytic Results, Bhimsen K. Shivamoggi, David K. Rollins

Faculty Bibliography 1990s

Further analytic results are deduced with the magnetohydrodynamic boundary layer equations for a flat plate. The asymptotic behavior of the solutions is deduced using the scaling group method. Then, an analytic perturbative procedure is used to determine an approximate solution that exhibits this asymptotic behavior.

Unique Properties Of Quadratic Solitons, G. I. Stegeman, R. Fuerst, R. Malendevich, R. Schiek, Y. Baek, I. Bauman, W. Sohler, G. Leo, G. Assanto, Ch. Bosshard, P. Günter

Faculty Bibliography 1990s

Quadratic spatial solitons exist in media with second order nonlinearities near the phase-matching condition for frequency mixing processes involving two or three waves of different frequency. Discussed here are a number of properties of these special solitons which are different from those of other spatial solitons which rely on optically induced index changes for guiding. First, the self-guiding properties of quadratic solitons are shown to have completely different origins than solitons which rely on index changes. Second, it is shown that there exists a large variety of quadratic solitons which contain two or three distinct spectral components with relative amplitudes …

Studies On Passivation Behavior Of Tungsten In Application To Chemical Mechanical Polishing, D. Tamboli, S. Seal, V. Desai, A. Maury

Faculty Bibliography 1990s

Chemical mechanical polishing (CMP) is considered to be the enabling technology for meeting the planarization requirements in < 0.35 mu m feature sized multilevel semiconductor device fabrication. CMP of tungsten is done in order to planarize and remove excess tungsten in the process to form inter-level contacts. Considerable importance is given to the role played by the passive oxide film formation on the surface during tungsten CMP. In this study, x-ray photoelectron spectroscopy (ICPS) is used to understand the oxide growth mechanism in tungsten. Tungsten wafers are polarized to different anodic potentials in static pH 4 solutions of KIO3 and H2O2, two commonly used oxidizers in CMP. XPS measurements are employed to probe the chemical and stoichiometric changes in the surface oxide films treated under these conditions. These results are then compared with the electrochemical polarization results.

Invariant Painleve Analysis And Coherent Structures Of Two Families Of Reaction-Diffusion Equations, Ugur Tanriver, S. Roy Choudhury

Faculty Bibliography 1990s

Exact closed-form coherent structures (pulses/fronts/domain walls) having the form of complicated traveling waves are constructed for two families of reaction-diffusion equations by the use of invariant Painleveacute analysis. These analytical solutions, which are derived directly from the underlying PDE's, are investigated in the light of restrictions imposed by the ODE that any traveling wave reduction of the corresponding PDE must satisfy. In particular, it is shown that the coherent structures (a) asymptotically satisfy the ODE governing traveling wave reductions, and (b) are accessible to the PDE from compact support initial conditions. The solutions are compared with each other, and with …

Quasi-Analytical Solutions For Apsidal Motion In The Three-Body Problem: Sun - Minor Planet - Jupiter, Wan Xian Wang, N. Y. Misconi

Faculty Bibliography 1990s

This paper deals with the effect of a third body on the apsidal motion of two bodies. The specific case involves a third body-planet Jupiter and the apsidal line motion of a minor planet that orbits the Sun and has its apsidal line go through the major axis of an ellipse. The third body (Jupiter) which satisfies the Langrangian solution will affect the apsidal line motion and therefore affects the ascending and descending motions of the minor planet. In this case no analytical solutions can be obtained, and therefore specific assumptions are made along with numerical solutions. For convenience, we …

Histogram Specification Of 24-Bit Color Images In The Color Difference (C-Y) Color Space, A. R. Weeks, L. J. Sartor, H. R. Myler

Faculty Bibliography 1990s

Histogram equalization and specification have been widely used to enhance information in a gray scale image, with histogram specification having the advantage of allowing the output histogram to be specified as compared to histogram equalization, which attempts to produce an output histogram that is uniform Unfortunately, expanding histogram techniques to color images is not very straightforward Since humans are sensitive to chromatic changes, care must be taken to ensure that incorrect colors are not produced. Additionally expanding the one-dimensional histogram used in gray level histogram techniques to a joint histogram (usually of three variables representing the primary colors of red, …

Nscat Normalized Radar Backscattering Coefficient Biases Using Homogenous Land Targets, Josko Zec, David G. Long, W. Linwood Jones

Faculty Bibliography 1990s

The NASA scatterometer (NSCAT) is a spaceborne radar sensor designed to measure the normalized radar backscattering coefficient sigma(o) of the Earth's surface. Over the ocean, backscatter measurements are used to infer surface wind vectors. Wind retrieval is based on a statistical relationship between short-ocean wave roughness (that causes the backscatter) and the surface wind speed and direction. For NSCAT geometry, multiple antennas are used to provide backscatter measurements at several azimuth directions to resolve wind direction ambiguities. To achieve the desired wind vector accuracy, these antenna beams must be calibrated within a few tenths of a decibel. A simple relative-calibration …

Nitrogen Incorporation And Trace Element Analysis Of Nanocrystalline Diamond Thin Films By Secondary Ion Mass Spectrometry, D. Zhou, F. A. Stevie, L. Chow, J. Mckinley, H. Gnaser, V. H. Desai

Faculty Bibliography 1990s

Nitrogen has been successfully incorporated into nanocrystalline diamond films produced by a CH4/N-2 microwave plasma-enhanced chemical vapor deposition method. High mass resolution secondary ion mass spectrometry (SIMS) characterization shows that the density of the incorporated nitrogen, monitored via CN-, can be as high as 10(21) atoms/cm(3) depending on the ratio of CH4 to N-2 in the reactant gas and on the substrate temperature used for the film preparation. SIMS depth profiles demonstrate that the incorporated nitrogen is uniform within the diamond films (about 1.5 mu m thick) except at the surfaces and at the interface between film and substrate. Furthermore, …

Crummer Graduate School, Rollins College

Text Materials of Central Florida

Rollins College catalogue with list of faculty and students and courses by department.

Rollins College Brevard Campus, Rollins College

Text Materials of Central Florida

Rollins College catalogue with list of faculty and students and courses by department.

Finding A Voice: Poetry And Performance With First Graders, Lisa Lenz Bianchi

Doctoral Dissertations

This is a qualitative research study of a ten week immersion unit in the reading, writing, and performance of poetry conducted in a first grade classroom in Closter, New Jersey during the winter of 1995. The three girls selected as case studies show the ways in which remarkably different children expand their repertoires of ways with words as speakers, readers, and writers. Danielle, a performative speaker, learns to make her tacit knowledge about performance part of her explicit frames of reference. This shift enables her to serve as a coach for peers who are less adept at crafting performative texts. …

At The Heart Of It: Middle School Writers Use Talk And Multimedia Journals To Forge A Literate Classroom Community, Julie A. Pantano

Doctoral Dissertations

In this research study, I investigated how middle school writers use talk and multi-media journals to forge a literate classroom community. Talk and multi-media journals helped middle school writers to construct and maintain a safe, caring, supportive, and respectful learning environment where transformative literacy and learning experiences could take place.

Classroom talk played a vital role in improving students' relationships in this literate classroom community and engaging them in meaningful ways with their multi-media journals. During the research study, explicit instruction in the social aspects of talk emerged as important as explicit instruction in language arts content.

The multi-media approach …

Queering/Querying Identities: The Roles Of Integrity And Belonging In Becoming Ourselves, Cari Ann Elizabeth Moorhead

Doctoral Dissertations

This dissertation presents a picture of the complexities and contradictions in the daily lives of people in the Seacoast area of New Hampshire who identify as, or are identified as, lesbian, gay, bisexual, transgender, queer, questioning and allied people (LGBTQQA). The focus of this study is the "Create Our Destiny" conference, a social change project. Philosophically, I viewed this project through a Postmodern feminist lens, and methodologically I used a grounded theory approach.

This dissertation is divided into three sections. Within section one, I present more detailed descriptions of my philosophical and methodological approaches, a description of the geographical and …

Memoirs, Movements, And Meaning: Teacher/Student Research In Freshman Composition, Carol Ann Hawkins

Doctoral Dissertations

The author interprets her memoirs as a reader and writer to describe how the movement from I to We, a process of "repositioning," shifted her perceptions from "hating school" to wanting to teach. She begins by tracing her roots as a "white," working-class woman from Cleveland (1952--1970) and ends by disclosing "what worked and what didn't work" when teaching freshman composition at the University of New Hampshire (1994--1997). She draws on feminist, ethnographic, rhetorical, and critical theory to compose "thick descriptions" of her reading, writing, and teaching life. She juxtaposes her struggles with Others', like Min-Zhan Lu, to identify, interpret, …

Domestic Visions And Shifting Identities: The Urban Novel And The Rise Of A Consumer Culture In America, 1852-1925, Nancy Helen Von Rosk

Doctoral Dissertations

Domestic Visions reexamines the tradition of the urban novel in America by reading the works of Nathaniel Hawthorne, Henry James, William Dean Howells, Theodore Dreiser, Paul Laurence Dunbar, Edith Wharton, Abraham Cahan and Anzia Yezierska within the historical and cultural contexts of an evolving urban consumer culture. Bringing together not only a wide range of canonical and non-canonical texts, but also an analysis of America's shifting domestic ideals over the last half of the nineteenth and early twentieth centuries, this study traces the impact of a new spectacular urban public culture on both the private realm and those who are …

Thinking Through Performance: Children Make Sense Of Characters And Social Relationships Through A Gesture-Based Theatre Convention (Tableau), Georgia Patricia Wilson

Doctoral Dissertations

This inquiry considers a gesture-based theatre convention called tableau as used by first and second graders during language arts instruction. I argue that tableau acts as a medium of thinking, used to make sense of literary text and of social relationships. Tableau is largely non-language-based; it augments instructional practices that are primarily language-based. Tableau reveals sophisticated understandings children cannot yet put into language. As such, tableau offers educators a means to cast children as capable analysts of literature.

Qualitatively oriented, this inquiry uses instrumental case study methods of observation and data analysis coupled with a concurrent conceptual study of the …

Motherwork, Artwork: The Mother/Artist In Fiction By Parton, Phelps, Chopin, Woolf, Drabble, And Walker, Nancy Hoyt Lecourt

Doctoral Dissertations

This study asks the question, What happens to a practicing (fictional) mother who also tries to be a practicing artist? How do literary texts represent such people? How do they represent the relationship between material and artistic work? The primary works studied are Sarah Parton's Ruth Hall, (1855), Elizabeth Stuart Phelps' The Story of Avis (1877), Kate Chopin's The Awakening (1899), Virginia Woolf's To the Lighthouse (1927), and Margaret Drabble's The Millstone (1965). The conclusion focuses on Alice Walker's short story, "Everyday Use."

Mother-artists finds themselves on the "wrong" side of the nature/culture binary, where ideologies about "true womanhood" and …

Confronting The War Machine: Draft Resistance During The Vietnam War, Michael Stewart Foley

Doctoral Dissertations

This dissertation recovers the history of the draft resistance movement in Boston during the Vietnam War. It is a blend of social, political, and cultural history that seeks not merely to assert the importance of draft resistance to our understanding of the antiwar movement and the Vietnam War era, but also to capture the experience of draft resisters and their supporters.

It is an actor-oriented history. The sources used include the personal private manuscript collections of participants, court records, underground newspapers, a 1997 survey administered to 310 former resisters and draft resistance activists (185 responded), and interviews with more than …