With the advent of the 21st century, technological innovations are transforming the face of education and the school library media center. One of these significant developments is the ability to communicate through the Internet. The purpose of this study is to examine the perceptions of Texas public school library media specialists who are active Internet users about their utilization of the Internet, and how their efforts in implementing and supervising Internet access in their school library media centers impact the Texas public schools that they serve. A survey instrument of Likert items was developed that queried these public school library media specialists for their perceptions of Internet use in their schools. MANOVA was the chosen statistical measure for this study. An initial electronic mail-out to 1,232 Texas public school library media specialists (K-12) with Internet addresses were contacted to participate in this study. After a time frame of one month, 196 Texas school library media specialists e-mailed the researcher, confirming their willingness to be a survey participant. All respondents to this e-mail request participated in this study, and a second U.S. mail-out was sent containing the actual survey instrument. The researcher found that the use of the Internet by school …

Nucleon structure functions measured in neutrino-iron and antineutrino-iron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 GeV. The structure functions F{sub 2} and xF{sub 3} are compared with the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives value of {Lambda}NLO,(4)/MS = 337 {+-} 28 (exp.) MeV, which corresponds to {alpha}{sub S}(M{sub Z}{sup 2}) = 0.119 {+-} 0.002 (exp.) {+-} 0.004 (theory), and with a gluon distribution given by xG(x,Q{sub 0}{sup 2} = 5GeV{sup 2}) = (2.22 {+-} 0.34) {times} (1 {minus} x){sup 4.65{+-}0.68}.

This study sought to create a guideline to assist theological seminaries build a longitudinal database for institutional research. The study used the National Center for Higher Education Management (NCHEMS) data element dictionary as the base document for the study.

Using a sample of 4,500 polarized Z decays to {tau} lepton pairs accumulated with the SLD detector at the SLAC Linear Collider (SLC) in 1993-95, a search has been made for anomalous couplings in the neutral current reaction e{sup +}e{sup {minus}}{yields}{tau}{sup +}{tau}{sup {minus}}. A measurement of the CP violating Weak Electric Dipole Moment (WEDM) and the CP conserving Weak Magnetic Dipole Moment (WMDM) of the {tau} lepton has been performed by considering the transverse spin polarization of {tau} leptons produced at the Z pole. Using a maximum likelihood technique, the observed {tau} decay spectra in the e, {mu}, {pi}, and {rho} decay channels are used to infer the net transverse polarization of the underlying tau leptons, and a fit for the anomalous dipole moments is performed. No evidence for these dipole movements is observed, and limits are placed on both the real and imaginary parts of the WEDM and WMDM.

A conceptual management framework is developed and applied in a science and engineering organization located within a non-profit, public institution. The goal of this research is to select a set of projects whose combined contributions to the organization`s strategic interests satisfy sponsor desires and can be completed within existing time and resource constraints. The development of the rationale for project selection and implementation within the plutonium facility at Los Alamos National Laboratory is studied. This includes the integration of prioritization decision tools, optimization techniques, and advanced planning and scheduling tools. The Nuclear Materials Technology Division is the custodian of the plutonium facility, whose mission is to develop, demonstrate, and deploy technologies necessary to address the nation`s and world`s plutonium problems. This includes management of nuclear weapon stockpile components, stabilization of plutonium residues, clean-up of contaminated soils and facilities, support to non-proliferation and arms control initiatives, and the eventual disposition of surplus plutonium. In this study, projects are evaluated against selection criteria deemed to be of critical program importance. The Analytic Hierarchy Process is used to evaluate and rank the importance of the suite of candidate projects. Because individual projects may be of interest to a number of business sectors and …

This thesis contains the study of highly forbidden resonant second harmonic generation (SHG) in atomic potassium vapor using tunable picosecond pulses. Various output characteristics of vapor SHG have been investigated including the input intensity dependence, potassium vapor density dependence, buffer gas pressure dependence, and spatial profile. Recently, the discovery of new nonlinear optical crystals such as barium borate ({beta}-BaB{sub 2}O{sub 4}, BBO) and lithium borate (LiB{sub 3}O{sub 5}, LBO) has greatly improved the performance of a tunable coherent optical devices based on optical parametric generation and amplification. In the second part of this thesis, a homebuilt picosecond optical parametric generator/amplifier (OPG/OPA) system is described in detail, including its construction details and output characteristics. This laser device has found many useful applications in spectroscopic studies including surface nonlinear optical spectroscopy via sum-frequency generation (SFG). The last part of this thesis reports studies on multiphoton-excited photoluminescence from porous silicon and GaN. Multiphoton excitation and photoluminescence can give numerous complementary information about semiconductors not obtainable with one-photon, above-bandgap excitation.

In the first part of this work, the author describes studies of donors in AlSb and in GaAs at large hydrostatic pressures, two materials in which the conduction band minimum is not parabolic, but has a camel`s back shape. These donors were found to display only one or two absorption lines corresponding to ground to bound excited state transitions. It is shown that due to the non-parabolic dispersion, camel`s back donors may have as few as one bound excited state and that higher excited states are auto-ionized. Thus, it is possible that transitions to these other states may be lost in the continuum. In the second part, calculations of mobilities in GaN and other group III-Nitride based structures were performed. GaN is interesting in that the carriers in nominally undoped material are thought to originate from impurities which have an ionization energy level resonant with the conduction band, rather than located in the forbidden gap. These donors have a short range potential associated with them which can be effective in scattering electrons in certain situations. It was found that effects of these resonant donors can be seen only at high doping levels in III-Nitride materials and in Al{sub x}Ga{sub 1{minus}x}N …

After introducing the subject of conjugated polymers, the thesis has three sections each containing a literature survey, results and discussion, conclusions, and experimental methods on the following: synthesis, characterization of electroluminescent polymers containing conjugated aryl, olefinic, thiophene and acetylenic units and their studies for use in light-emitting diodes; synthesis, characterization and study of conjugated polymers containing silole unit in the main chain; and synthesis, characterization and study of silicon-bridged and butadiene-linked polythiophenes.

Highly dispersed transition metal catalysts are used in numerous commercial processes such as hydrocarbon conversions. For example, the use of Pt supported on acidic alumina or silica-alumina for reforming of naphtha in the production of gasoline is well known. Another use of supported catalysts is in automobile emission control where supported Pt-Rh bimetallic catalysts are used. Supported Ru can be used in Fischer-Tropsch synthesis for the production of higher hydrocarbons from synthesis gas. While many of these catalyst systems have been in commercial operation for several decades there is still a lack of consensus regarding the exact role of the catalyst on a molecular level. In particular, little is known about the mechanisms operating on the catalyst surface at the high pressure and high temperature conditions typically used in commercial operations. This report contains the general introduction and conclusions and an appendix containing the operating instructions for a microcalorimeter. Three chapters have been processed separately. They are: the effect of K on the kinetics and thermodynamics of hydrogen adsorption on Ru/SiO{sub 2}; hydrogen adsorption states on silica supported Ru-Ag and Ru-Cu bimetallic catalysts investigated via microcalorimetry; a comparative study of hydrogen chemisorption on silica supported Ru, Rh, and Pt.

Combined scanning tunneling microscopy (STM) and low energy electron diffraction (LEED) measurements from Gd films grown on W(110) prepared with and without annealing have been used to provide a detailed picture of the growth of such films, permitting a quantitative structural explanation for previously-measured magnetic properties and the identification of a new two-dimensional structure for the first monolayer. The analysis of the film roughness of room-temperature-grown films as a function of coverage and lateral length scale reveals that the growing Gd surface follows scaling laws for a self-affine surface. Annealing these as-deposited films at elevated temperatures is found to drastically alter the morphology of the films, as seen by both STM and LEED. Nanometer-scale islands of relatively well-defined size and shape are observed under certain conditions. Finally, the first monolayer of Gd is observed to form a (7x14) superstructure with pseudo-(7x7) symmetry that is consistent with a minimally-distorted hexagonal two-dimensional Gd(0001) film. Furthermore, a new beamline and photoelectron spectrometer/diffractometer at the Advanced Light Source have been used to obtain full-solid-angle and site-specific photoelectron diffraction (PD) data from interface W atoms just beneath (1x1) Fe and (7x14) Gd monolayers on W(110) by utilizing the core level shift in the W 4f{sub …

Time variability analyses have been applied to data composed of event times of X-rays emitted from the binary system Cygnus X-1 to search for unique black hole signatures. The X-ray data analyzed was collected at ten microsecond time resolution or better from two instruments, the High Energy Astrophysical Observatory (HEAO) A-1 detector and the Rossi X-ray Timing Explorer (XTE) Proportional Counter Array (PCA). HEAO A-1 and RXTE/PCA collected data from 1977--79 and from 1996 on with energy sensitivity from 1--25 keV and 2--60 keV, respectively. Variability characteristics predicted by various models of an accretion disk around a black hole have been searched for in the data. Drop-offs or quasi-periodic oscillations (QPOs) in the Fourier power spectra are expected from some of these models. The Fourier spectral technique was applied to the HEAO A-1 and RXTE/PCA data with careful consideration given for correcting the Poisson noise floor for instrumental effects. Evidence for a drop-off may be interpreted from the faster fall off in variability at frequencies greater than the observed breaks. Both breaks occur within the range of Keplerian frequencies associated with the inner edge radii of advection-dominated accretion disks predicted for Cyg X-1. The break between 10--20 Hz is also …

Following, a review of experimental techniques, theory, and previous work, the results of local vibrational mode (LVM) spectroscopy on hydrogen-related complexes in several different semiconductors are discussed. Hydrogen is introduced either by annealing in a hydrogen ambient. exposure to a hydrogen plasma, or during growth. The hydrogen passivates donors and acceptors in semiconductors, forming neutral complexes. When deuterium is substituted for hydrogen. the frequency of the LVM decreases by approximately the square root of two. By varying the temperature and pressure of the samples, the microscopic structures of hydrogen-related complexes are determined. For group II acceptor-hydrogen complexes in GaAs, InP, and GaP, hydrogen binds to the host anion in a bond-centered orientation, along the [111] direction, adjacent to the acceptor. The temperature dependent shift of the LVMs are proportional to the lattice thermal energy U(T), a consequence of anharmonic coupling between the LVM and acoustical phonons. In the wide band gap semiconductor ZnSe, epilayers grown by metalorganic chemical vapor phase epitaxy (MOCVD) and doped with As form As-H complexes. The hydrogen assumes a bond-centered orientation, adjacent to a host Zn. In AlSb, the DX centers Se and Te are passivated by hydrogen. The second, third, and fourth harmonics of the …

This dissertation explores in large part the development of a few types of spectroscopic methods in the analysis of water. Methods for the determination of some of the most important properties of water like pH, metal ion content, and chemical oxygen demand are investigated in detail. This report contains a general introduction to the subject and the conclusions. Four chapters and an appendix have been processed separately. They are: chromogenic and fluorogenic crown ether compounds for the selective extraction and determination of Hg(II); selective determination of cadmium in water using a chromogenic crown ether in a mixed micellar solution; reduction of chloride interference in chemical oxygen demand determination without using mercury salts; structural orientation patterns for a series of anthraquinone sulfonates adsorbed at an aminophenol thiolate monolayer chemisorbed at gold; and the role of chemically modified surfaces in the construction of miniaturized analytical instrumentation.

This report contains a general introduction which discusses solid-phase extraction and solid-phase micro-extraction as sample preparation techniques for high-performance liquid chromatography, which is also evaluated in the study. This report also contains the Conclusions section. Four sections have been removed and processed separately: silicalite as a sorbent for solid-phase extraction; a new, high-capacity carboxylic acid functionalized resin for solid-phase extraction; semi-micro solid-phase extraction of organic compounds from aqueous and biological samples; and the high-performance liquid chromatographic determination of drugs and metabolites in human serum and urine using direct injection and a unique molecular sieve.

Gabor first proposed holography in 1948 as a means to experimentally record the amplitude and phase of scattered wavefronts, relative to a direct unscattered wave, and to use such a {open_quotes}hologram{close_quotes} to directly image atomic structure. But imaging at atomic resolution has not yet been possible in the way he proposed. Much more recently, Szoeke in 1986 noted that photoexcited atoms can emit photoelectron of fluorescent x-ray wavefronts that are scattered by neighboring atoms, thus yielding the direct and scattered wavefronts as detected in the far field that can then be interpreted as holographic in nature. By now, several algorithms for directly reconstructing three-dimensional atomic images from electron holograms have been proposed (e.g. by Barton) and successfully tested against experiment and theory. Very recently, Tegze and Faigel, and Grog et al. have recorded experimental x-ray fluorescence holograms, and these are found to yield atomic images that are more free of the kinds of aberrations caused by the non-ideal emission or scattering of electrons. The basic principles of these holographic atomic imaging methods are reviewed, including illustrative applications of the reconstruction algorithms to both theoretical and experimental electron and x-ray holograms. The author also discusses the prospects and limitations of these …

Experimental and numerical studies of the Inverse Free Electron Laser using a GW-level 10.6 {mu}m CO{sub 2} laser have been carried out at Brookhaven`s Accelerator Test Facility. An energy gain of 2.5 % ({Delta}E/E) on a 40 MeV electron beam has been observed E which compares well with theory. The effects on IFEL acceleration with respect to the variation of the laser electric field, the input electron beam energy, and the wiggler magnetic field strength were studied, and show the importance of matching the resonance condition in the IFEL. The numerical simulations were performed under various conditions and the importance of the electron bunching in the IFEL is shown. The numerical interpretation of our IFEL experimental results was examined. Although good numerical agreement with the experimental results was obtained, there is a discrepancy between the level of the laser power measured in the experiment and used in the simulation, possibly due to the non-Gaussian profile of the input high power laser beam. The electron energy distribution was studied numerically and a smoothing of the energy spectrum by the space charge effect at the location of the spectrometer was found, compared with the spectrum at the exit of the wiggler. The …

High-power, pulsed, coherent, far-infrared (FIR) radiation has many scientific applications, such as pump-probe studies of surfaces, liquids, and solids, studies of high-T{sub c} superconductors, biophysics, plasma diagnostics, and excitation of Rydberg atoms. Few sources of such FIR radiation currently exist. Superradiant undulator radiation produced at the SUNSHINE (Stanford UNiversity SHort INtense Electron-source) is such a FIR source. First proposed in the mm-wave spectral range by Motz, superradiant undulator radiation has been realized in the 45 {micro}m to 300 {micro}m spectral range by using sub-picosecond electron bunches produced by the SUNSHINE facility. The experimental setup and measurements of this FIR radiation are reported in this thesis. In addition, to being a useful FIR source, the superradiant undulator radiation produced at SUNSHINE is an object of research in itself. Measured superlinear growth of the radiated energy along the undulator demonstrates the self-amplification of radiation by the electron bunch. This superlinear growth is seen at 47 {micro}m to 70 {micro}m wavelengths. These wavelengths are an order of magnitude shorter than in previous self-amplification demonstrations.

In the first part of this dissertation, the variation of mean emitter depths with direction for core photoelectron emission from single crystals, including the effects of both isotropic inelastic scattering and single and multiple elastic scattering was theoretically studied. The mean emitter depth was found to vary by as much as ±30% with direction. In the second part of this dissertation, x-ray photoelectron diffraction (XPD) was used to study the structure and growth mechanisms of Cu films grown on a clean and an oxygen-precovered Ru(OOO1) surface. Experimental Cu 2p3/2 (E_kin = 556 eV) and Ru 3d (E_kin = 1205 eV) intensities were measured for Cu coverages from submonolayer up to several monolayer (ML) on the clean Ru(OOO1) surface. In addition, the O 1s (E_kin = 958 eV) intensity was measured for Cu grown on oxygen precovered Ru(OOO1). These XPD intensities have been analyzed using single scattering cluster (SSC) and multiple scattering cluster (MSC) models. The first Cu layer has been found to grow pseudomorphically on the Ru(OOO1) surface in agreement with prior studies of the Cu/Ru(OOO 1) system. Thus, the initial growth is layer-by-layer. For higher coverages, XPD shows that the short-range structure of the Cu films is fcc Cu(l …