Digital Commons Network^™

Third Harmonic Generation Measurement Of Nonlinearities In Sio2-Tio2 Sol-Gel Films, W. E. Torruellas, L. A. Weller-Brophy, R. Zanoni, G. I. Stegeman, Z. Osborne, B. J. J. Zelinski

Faculty Bibliography 1990s

Third-harmonic generation has been used to measure the magnitude and phase of the nonlinear susceptibility chi-(3) (3-omega) of SiO2-TiO2 sol-gel thin films as a function of TiO2 concentration. Nonlinearities 20 times larger than those of fused silica were found, making such films useful for nonlinear optics in glass waveguides.

Enhancement Of Excited-State Population Of Magnesium-Ions Upon Decay Of Autoionizing Resonances, S. B. Whitfield, C. D. Caldwell, M. O. Krause

Faculty Bibliography 1990s

Decay of autoionizing resonances in atoms often leads to preferential production of excited states of the resulting ion. The population of these states can exceed the population of the ground state by more than an order of magnitude. We report measurements of the branching ratios for Mg+ ions resulting from the decay of selected autoionizing levels. These derived either from single excitation of a 2p electron or from two-electron excitations. For excited states of the type 2p5(2P1/2,3/2)3s2ns, n = 4 or 5, production of Mg+ ions having the final configuration 2p6ns is the predominant decay feature. For n > 5, the …

Shake-Modified Resonant Autoionization In Magnesium, S. B. Whitfield, J. Tulkki, T. Aberg

Faculty Bibliography 1990s

Anomalous features in the resonantly excited 2p autoionization spectrum of Mg are attributed to overlapping shake transitions of the excited bound (spectator) electron. Universal features of the shake spectrum are displayed and related to the post-collision interaction.

Temperature And Impact Ionization Effects On Ft Of Advanced Bipolar-Transistors, J. S. Yuan, C. S. Yeh, B. Gadepally

Faculty Bibliography 1990s

Modeling the cutoff frequency (f(T)) of the advanced bipolar transistors at avalanche breakdown has been developed. The analytical equations developed account for temperature and impact ionization effects on f(T) and high-current effects at the collector-base junction. Process sensitivity of the collector charging time at the avalanche breakdown regime has been examined. The experimental data reported in the literature are compared in support of the model. Good agreement between the model prediction and measurement is obtained.

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 Winter Term 1991, Rollins College

Text Materials of Central Florida

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

Geometry Of Quantum Evolution And The Coherent State, Subir K. Bose, Binayak Dutta-Roy

Faculty Bibliography 1990s

The geometric approach to quantum mechanics initiated by Berry's remarkable discovery [Proc. R. Soc. London Ser. A 392, 45 (1984)] of the anholonomy of the phase of the wave function and subsequent developments leading to a recent reformulation of the geometry of quantum evolution by Anandan and Aharonov [Phys. Rev. Lett. 65, 1697 (1990)] is shown to find an explicit and suggestive realization through the coherent-state representation.

Partial Cross-Sections And Photoelectron Angular-Distributions In The Region Of The 4s- 5p And 5s- 6p Resonances In Krypton And Xenon, M. G. Flemming, J. -Z. Wu, C. D. Caldwell, M. O. Krause

Faculty Bibliography 1990s

Using synchrotron radiation and photoelectron spectrometry, we have examined the 4s4p (6)5p resonance region in krypton and the 5s5p (6)6p resonance region in xenon. We have obtained partial and total cross sections, intensity ratios, and photoelectron angular distribution parameters for the energy regions 20.6-21.5 eV in xenon and 24.6-25.3 eV in krypton. We also report Shore parameters for all cross-section data taken. In addition to the anticipated single-electron transition, we clearly resolve features attributable to two-electron transitions in both species. Characteristics of these autoionizing states may differ considerably in the two available exit channels.

The Fabrication Of Metal-Oxide Semiconductor Transistors Using Cerium Dioxide As A Gate Oxide Material, A. G. Frangoul, K. B. Sundaram, P. F. Wahid

Faculty Bibliography 1990s

Cerium dioxide was employed as a gate insulator for an enhancement-type n-channel metal-oxide-semiconductor (MOS) transistor. Cerium was evaporated in a tungsten boat and immediately oxidized for oxide uniformity. The use of CeO2 as a gate oxide in MOS transistor yielded a low positive threshold voltage with negligible interface charge effects. This resulted in the transistor performing as an enhancement type device.

Improved Interface State Density-Function In Metal-Semiconductor Junctions By Deep-Level Transient Spectroscopy, N. C. Halder, H. W. Kim, K. M. D'Souza, D. E. Barnes, S. E. Hartson, R. Mohapatra

Faculty Bibliography 1990s

Deep-level transient spectroscopy (DLTS) measurements have been made to obtain the activation energy and capture cross section in Schottky diodes. Previous theories for interface state density (ISD) functions, which are derived for metal-semiconductor junctions, made approximations that were inappropriate. This paper derives improvements to the previous analysis and calculates ISD using the measured DLTS data. As for examples, Schottky diodes of Si, GaAs, and Al(x)Ga(1-x)As have been investigated with both methods. It has been found that the previously used method overestimated both the peak maximum position and peak height of the ISD.

Modeling Of Cross-Well Carrier Transport In A Multiple Quantum-Well Modulator, D. C. Hutchings, C. B. Park, A. Miller

Faculty Bibliography 1990s

A self-consistent time and spatially resolved model is developed to explain the nature of cross-well transport in multiple quantum well devices. It is this cross-well transport that sets fundamental limits on the speed of such devices. This model is solved numerically to obtain a fit to experimental excite-probe data. A good fit to rise times is obtained with resonant tunneling features predicted and observed. It is also predicted that as the transient features in the transmission data relax, many carriers are still bound in the quantum wells.

130 Ps Recovery Of All-Optical Switching In A Gaas Multiquantum Well Directional Coupler, P. Li Kam Wa, A. Miller, J. S. Roberts, P. N. Robson

Faculty Bibliography 1990s

A significantly improved recovery time of 130 ps has been achieved in an all-optical zero-gap directional coupler containing multiple quantum wells. The mechanism for the all-optical switching is due to free-carrier induced refractive nonlinearities at near-band-gap resonant frequencies. The large reduction in the switch recovery time was obtained by the application of an external dc bias which sweeps out the carriers from the quantum wells. From our experimental results on the laser pulse width limited switch-up time of 2 ps, we deduce that the contribution of self-electro-optic effect nonlinearity is negligible in this case.

Reply To "Comments On 'Effects Of Using The More Accurate Intrinsic Concentration On Bipolar-Transistor Modeling' ", J. J. Liou

Faculty Bibliography 1990s

This reply addresses the issues raised by Rode and Rosenbaum regarding the bipolar junction transistor model developed in the subject paper [J. Appl. Phys. 68, 5911 (1990)]. The error associated with Eq. (4) in the subject paper is discussed and corrected, the value of the space-charge-region recombination time used is specified, and the results are recalculated. It is shown that the error in Eq. (4) does not alter notably the trends of the current gain calculated using the two different intrinsic concentrations.

Soft X-Ray Projection Lithography Using A 1-1 Ring Field Optical-System, A. A. Macdowell, J. E. Bjorkholm, J. Bokor, L. Eichner, R. R. Freeman, W. M. Mansfield, J. Pastalan, L. H. Szeto, D. M. Tennant, O. R. Wood Ii, T. E. Jewell, W. K. Waskiewicz, D. L. White, D. L. Windt, W. T. Silfvast, F. Zernike

Faculty Bibliography 1990s

An iridium-coated Offner 1:1 ring field camera has been used to carry out projection lithography using 42 nm light from an undulator in the vacuum ultra violet storage ring at Brookhaven National Laboratory. Near-diffraction-limited resolution has been obtained showing features as small as 0.2-mu-m within a 2 mm x 0.25 mm image field. Images of both transmission and reflection masks have been obtained. The impact of source coherence on imagery has been investigated. Hydrocarbon contamination problems experienced in this photon energy range have been investigated and possible solutions are suggested.

Painleve Analysis And Lie Group Symmetries Of The Regularized Long-Wave Equation, David K. Rollins

Faculty Bibliography 1990s

The Painleve formulation is given for the regularized long-wave equation, which has been used to describe shallow water waves and drift waves in a plasma. The Lie group symmetries of the equation is then studied and it is shown that the only symmetries are due to the three conserved quantities.

Accurate Abinitio Calculations On Elastic-Scattering Of Low-Energy Electrons By Argon Atoms, H. P. Saha

Faculty Bibliography 1990s

The multiconfiguration Hartree-Fock method has been applied to study low-energy scattering of electrons from argon atoms. The polarization of the argon atoms due to the scattered electron and the electron-correlation effects that are very important in the calculation are taken into account in the ab initio way more accurately through the configuration-interaction procedure. Phase shifts for various partial waves calculated in this approximation have been used to calculate elastic differential, total elastic, and momentum-transfer cross sections. The present results are compared with the experimental and other theoretical results. It is found that the present results are in very good agreement …

Multiconfiguration Hartree-Fock Calculation Of The Photoionization Of The Excited N 2p(2)3p 2s State, H. P. Saha

Faculty Bibliography 1990s

The partial photoionization cross sections and asymmetry parameter of the excited state 2p(2)3p2S of nitrogen have been calculated using the multiconfiguration Hartree-Fock method for continuum wave functions. The effects of electron correlation on the excited initial state, the ionic core state, and the final continuum state have been taken into account in an ab initio manner through the configuration-interaction procedure. It is found that the correlations do not change the result significantly from that obtained with Hartree-Slater and Hartree-Fock calculations. The present result of the asymmetry parameter is seen to be in excellent agreement with the experimental measurement of Pratt, …

Precipitation, Inter-Event Dry Periods, And Reuse Design Curves For Selected Areas Of Florida, Martin Wanielista

BMP Trains Research and Publications

No abstract provided.

Error Control Coding For Meteor Burst Communications, Thomas J. Frederick

Retrospective Theses and Dissertations

The phenomenon of meteor burst communications is described and its mathematical model is presented. Protocols for meteors burst systems are outlined and examples are given of current use. Recent research in the area of coding performance in meteor burst systems is pointed out. The performance of several error control coding schemes for a meteor burst channel, including two new adaptive algorithms, are evaluated via analysis and simulation. These coding strategies are compared using the probability of successful transmission of a fixed size packet through a single burst as a performance measure. The coding methods are compared via simulation for several …

Itasq : An Ada-Based Interactive Tool For Assessing Software Quality, Ruby Marie Heintze

Retrospective Theses and Dissertations

The goal of producing high quality computer programs brings with it the need for a set of quantitative measures that software engineers can use to measure various aspects of software quality. These quantitative measures, known as software metrics, can measure different aspects of program quality. For example, McCabe's Complexity Metric measures the decision structure of a computer program; Halstead's Software Science measures program "impurities II such as unfactored expressions and unnecessary replacements; and Vitro•s Module Coupling Metric measures data transfer characteristics between modules. Using only one of these metrics would not provide a well rounded measure of overall software quality. …

Immunochemical Characterization Of The Antigenic And Allergenic Components Of The Plant Pollens Of Paspalum Notatum. Callistemon Citrinis And Melaleuca Leucadendron, Saeed S. Hosseiny

Retrospective Theses and Dissertations

Antigenic as well as allergenic cross-reactivity was observed among the pollen extracts of Paspalum notatum, bahia (BA); Callistemon citrinis, bottlebrush (BO); and Melaleuca leucadendron, melaleuca (ME). lmmunoblot analysis of SOS-PAGE separated proteins revealed multiple antigenic components in the extracts of all three allergens which cross-reacted with rabbit antisera made to each pollen extract (anti-BA, anti-BO and anti-ME). A unique antigenic component of 15 kD molecular size reacting only to rabbit anti-BA antisera was detected in the bahia extract. Allergenic cross-reactivity among these pollens was strongly suggested by results obtained with skin testing of allergic individuals. A clinical study of 55 …

Newspaper Endorsements : How Editorial Writers View Their Influence, Lisa Ferguson Lochridge

Retrospective Theses and Dissertations

No abstract provided.

Anxiety Levels, Problem Solving Abilities And Social Support In Military Spouses Experiencing Spousal Separation Prior To A Military Confrontation, Elizabeth C. Smith

Retrospective Theses and Dissertations

The effects of spousal separation on military dependents were investigated. Thirty-four female spouses of active duty United States Air Force personnel responded to a mail-out questionnaire following deployment of troops to the Persian Gulf, yet prior to the beginning of the Desert Storm military confrontation. The study examined the state anxiety levels (Spielberger state-Trait Anxiety Inventory), the problem solving abilities (Problem Solving Inventory), and the social support levels (Provision of Social Relations scale) of the subjects. The results of this investigation revealed that the subjects without children perceived themselves to be stronger problem solvers than those subjects with children, that …

Surface Acoustic Wave Resonator Parameter Extraction And Oscillator Design, Mark Stephen Cavin

Retrospective Theses and Dissertations

Surface Acoustic Wave (SAW) resonators are frequently used in UHF oscillator designs. SAW resonators are available in the 100 MHz - 1 GHz frequency range which eliminates the need for frequency multiplication necessary with Bulk Acoustic Wave (BAW) devices. As operating frequencies increase, circuit parasitics play a larger role in device performance. One important source of parasitics is the device package and associated interconnects. To model a SAW resonator effectively, these parasitics need to be taken into account Resonator device models and their associated S-parameters can then be used in the design of oscillators. This thesis will discuss the design …

A Stratified Air Model For Simulation Of Attic Thermal Performance, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An improved computer simulation model for attics has been developed. The model accounts for detailed radiation, buoyancy and wind driven air flows and thermal stratification within the attic airspace. Through comparison with measured data, the paper examines the relative importance of the various modeling parameters and assumptions upon simulation accuracy. Stratification of the attic air was found to be a critical modeling characteristic which is typically ignored in building energy simulations. Both model and measurement results shows that air stratification increases significantly when low-emittance surfaces are included.

Impacts Of Duct Leakage On Infiltration Rates, Space Conditioning Energy Use, And Peak Electrical Demand In Florida Homes, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Testing for duct leakage was done in 91 homes. Tracer gas tests found that infiltration rates were four times greater when the air handler was operating than when it was off. Return leaks were found to average 10.0% of air handler total flow. House airtightness, in 63 of these homes, determined by blower door testing, averaged 12.38 air changes per hour at 50 Pascals (ACH50). When the duct registers were sealed, ACH50 decreased to 10.93, indicating that 11.7% of the house leaks were in the duct system.

Duct repairs were made on 25 homes. Blower door tests found 12.30 air …

From Outrageous Malevolence To Creative Humbuggery: The Problem Of "Fairness" In The Tenure Decision, Robert J. Doolittle

Association for Communication Administration Bulletin

This article interrogates fairness in tenure deliberations within American higher education, portraying the process as a rhetorical contract between institutions and their publics. Through conceptual analysis it contrasts two disruptive forces. Outrageous malice describes politically motivated denials rooted in enrollment rivalry, personal vendetta, and malicious committee orientation. Creative humbuggery denotes rule bending in service of rapid hiring or favoritism, eroding objective standards while claiming noble intent. The discussion details institutional obligations to establish transparent criteria, communicate expectations, and apply evaluations consistently, then diagnoses how secrecy, inconsistent documentation, and ad hoc negotiations undermine credibility. Concluding recommendations advocate early clarification of standards, …

An Intradisciplinary Perspective, Multiple Methods Of Inquiry And Faculty Development - A Point Of View, John J. Makay, Mary Mohan

Association for Communication Administration Bulletin

This article argues that effective faculty development in communication education requires an intradisciplinary perspective and mastery of multiple methods of inquiry. It critiques the trend toward interdisciplinary identity, urging scholars to center research within communication contexts while employing quantitative and qualitative approaches in concert. A model of intradisciplinary multi method inquiry is presented. The discussion considers technological change, shifting disciplinary boundaries, and the formation of scholarly teams as catalysts for continuous professional growth. By advocating literacy in diverse research traditions and collaborative inquiry, this article outlines a path that strengthens communication scholarship, enhances curricular relevance, and prepares faculty for emerging …

The Wichita Symposium, Philip Gaunt

Association for Communication Administration Bulletin

This article presents information on the topic "Beyond Agendas: New Directions in Communication Research" discussed at the Wichita symposium.

Seeing Our Discipline Through New Lens: Speech Communication In A Professional College, Angela Laird Brenton, John Gray

Association for Communication Administration Bulletin

This article examines how a speech communication department situated itself within a professional college and the pedagogical institutional and disciplinary implications of that relocation. Drawing on reflective analysis of a three year transition at a large public university the discussion foregrounds organizational communication theory curriculum design applied scholarship and accreditation discourse. The move fostered richer internships expanded joint degree pathways strengthened human resource development networks and prompted rigorous outcomes assessment. Faculty benefited through consulting interdisciplinary grant activity and improved salary parity while the department refined its professional identity and increased enrolment. Persistent tensions remain between liberal arts general education mandates …