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A Preliminary Study of the Systemic Problems Underlying U.S.-East European Trade Relations (open access)

A Preliminary Study of the Systemic Problems Underlying U.S.-East European Trade Relations

This study hypothesizes that the major barriers to expanded trade between the U.S. and Eastern Europe are systemic in nature. Using this approach, each political/ economic system is examined in an attempt to define the obstacles to foreign trade expansion, to describe the most important systemic and political factors at work, and to demonstrate how they have determined and will continue to shape the economic relationships between the U.S. and the countries of Eastern Europe. A final synthesis presents the two systems in a unified picture of the economic environment and concludes that significant trade expansion is unlikely in the near future due to basic systemic incompatibilities which impede the resolution of key foreign trade problems.
Date: March 1981
Creator: Abbott, Karen L.
System: The UNT Digital Library
Laser Ion Acceleration from the Interaction of Ultra-Intense laser Pulse with thi foils (open access)

Laser Ion Acceleration from the Interaction of Ultra-Intense laser Pulse with thi foils

The discovery that ultra-intense laser pulses (I > 10{sup 18} W/cm{sup 2}) can produce short pulse, high energy proton beams has renewed interest in the fundamental mechanisms that govern particle acceleration from laser-solid interactions. Experiments have shown that protons present as hydrocarbon contaminants on laser targets can be accelerated up to energies > 50 MeV. Different theoretical models that explain the observed results have been proposed. One model describes a front-surface acceleration mechanism based on the ponderomotive potential of the laser pulse. At high intensities (I > 10{sup 18} W/cm{sup 2}), the quiver energy of an electron oscillating in the electric field of the laser pulse exceeds the electron rest mass, requiring the consideration of relativistic effects. The relativistically correct ponderomotive potential is given by U{sub p} = ([1 + I{lambda}{sup 2}/1.3 x 10{sup 18}]{sup 1/2} - 1) m{sub o}c{sup 2}, where I{lambda}{sup 2} is the irradiance in W{micro}m{sup 2}/cm{sup 2} and m{sub o}c{sup 2} is the electron rest mass.At laser irradiance of I{lambda}{sup 2} {approx} 10{sup 20} W{micro}m{sup 2}/cm{sup 2}, the ponderomotive potential can be of order several MeV. A few recent experiments--discussed in Chapter 3 of this thesis--consider this ponderomotive potential sufficiently strong to accelerate protons from the …
Date: March 12, 2004
Creator: Allen, M
System: The UNT Digital Library
Testing CPT conservation using the NuMI neutrino beam with the MINOS experiment (open access)

Testing CPT conservation using the NuMI neutrino beam with the MINOS experiment

The MINOS experiment was designed to measure neutrino oscillation parameters with muon neutrinos. It achieves this by measuring the neutrino energy spectrum and flavor composition of the man-made NuMI neutrino beam 1km after the beam is formed and again after 735 km. By comparing the two spectra it is possible to measure the oscillation parameters. The NuMI beam is made up of 7.0%$\bar{v}$<sub>μ</sub>, which can be separated from the v<sub>μ</sub> because the MINOS detectors are magnetized. This makes it possible to study $\bar{v}$<sub>μ</sub> oscillations separately from those of muon neutrinos, and thereby test CPT invariance in the neutrino sector by determining the $\bar{v}$<sub>μ</sub> oscillation parameters and comparing them with those for v<sub>μ</sub>, although any unknown physics of the antineutrino would appear as a difference in oscillation parameters. Such a test has not been performed with beam $\bar{v}$<sub>μ</sub> before. It is also possible to produce an almost pure $\bar{v}$<sub>μ</sub> beam by reversing the current through the magnetic focusing horns of the NuMI beamline, thereby focusing negatively, instead of positively charged particles. This thesis describes the analysis of the 7% $\bar{v}$<sub>μ</sub> component of the forward horn current NuMI beam. The $\bar{v}$<sub>μ</sub> of a data sample of 3.2 x 10{sup 20} protons on …
Date: March 1, 2010
Creator: Auty, David John
System: The UNT Digital Library
Nucleation and dynamics of vortices in type-II superconductors (open access)

Nucleation and dynamics of vortices in type-II superconductors

The one- and two-dimensional Ginzburg-Landau equations are numerically integrated in a slab geometry, which is appropriate for comparison to experimental work done on films. When two-dimensional variations become energetically favorable, a vortex is found to nucleate and move to the center of the film with the Gibbs free energy decreasing during the process. An important process by which the energy is lowered during this nucleation procedure is found to be the savings in condensation energy arising from the shrinking size of the vortex core as it moves to the center of the film. The solutions of the Ginzburg-Landau equations are used to explain anomalies observed experimentally in the tunneling characteristics of thin films of PbIn. Excellent agreement between theory and experiment is found with the Ginzburg-Landau equations correctly predicting the field at which flux would first enter the films. We then use the Clem model of an isolated vortex to model vortex nucleation and dynamics under the influence of a transport current. The entry fields predicted by the model are found to be off by almost a factor of two but have the advantage of requiring simple computer programs for their solution, while the Ginzburg-Landau solutions require substantially more numerical …
Date: March 1, 1977
Creator: Balley, R. E.
System: The UNT Digital Library
Development of vertexing and lifetime triggers and a study of B(s) mixing using hadronic decays at D0 (open access)

Development of vertexing and lifetime triggers and a study of B(s) mixing using hadronic decays at D0

The D0 detector underwent a major upgrade to maximize its ability to fully exploit Run II at the Fermilab Tevatron, the world's highest energy collider. The upgrade included a completely new central tracking system with an outer scintillating fiber tracker and an inner silicon vertex detector all within a 2T superconducting solenoid. This thesis describes the development of high level trigger algorithms including vertexing, impact parameter significance and invariant mass, that utilize tracks from these detectors. One of the main physics goals of Run II is the observation of B{sub s} oscillations. This measurement, which cannot be performed at the B factories, will significantly constrain the ''unitarity triangle'' associated with Cp violation and so probe the Standard Model of particle physics. Furthermore this is an interesting measurement as the study of mixing in meson systems has a long history for revealing new physics. The second part of this thesis presents a study of the hadronic decay B{sub s} {yields} D{sub s}{pi}. This important mode provides the best proper time resolution for B{sub s} mixing and is reconstructed for the first time at D0. Projections on the sensitivity to B{sub s} oscillations are then presented.
Date: March 1, 2005
Creator: Barnes, Christopher P.
System: The UNT Digital Library
Toward a New Generation of Student Outcome Measures: Connecticut's Common Core of Learning Assessment (open access)

Toward a New Generation of Student Outcome Measures: Connecticut's Common Core of Learning Assessment

A report, "Toward a New Generation of Student Outcome Measures: Connecticut's Common Core of Learning Assessment" by Joan Boykoff Baron, Pascal D. Forgione, Jr. Douglas A. Rindone, Hanna Kruglanksi and Bruce Davey. Connecticut State, Department of Education, Division of Research, Evaluation and Assessment. 165 Capitol Avenue - Room 340. Hartford, Connecticut. Presented at American Education Association Annual Meeting, San Francisco, California. Part of Symposium 28.01 Beyond Effective Schools: Quality Indicators for Evaluation Schools and Districts. The Connecticut State Department of Education (CSDE) has begun a multi-year assessment of the extent to which students in Connecticut display the knowledge and traits described in the Common Core of Learning (CCL). Science and mathematics were the two chosen subjects to be assessed under CCL.
Date: March 29, 1989
Creator: Baron, Joan Boykoff; Forgione, Pascal D., Jr.; Rindone, Douglas A.; Kruglanksi, Hannah & Davey, Bruce
System: The UNT Digital Library
Measurement of the D_s Decay Constant f_Ds and Observation of New Charm Resonances Decaying to D^(*)\pi (open access)

Measurement of the D_s Decay Constant f_Ds and Observation of New Charm Resonances Decaying to D^(*)\pi

The absolute branching fractions for the decays D{sub s}{sup -} {yields} {ell}{sup -}{bar {nu}}{sub {ell}} ({ell} = e, {mu}, or {tau}) are measured using a data sample corresponding to an integrated luminosity of 521 fb{sup -1} collected at center of mass energies near 10.58 GeV with the BABAR detector at the PEPII e{sup +}e{sup -} collider at SLAC. The number of D{sub s}{sup -} mesons is determined by reconstructing the recoiling system DKX{gamma} in events of the type e{sup +}e{sup -} {yields} DKXD*{sub s}{sup -}, where D*{sub s}{sup -} {yields} D{sub s}{sup -} {gamma} and X represents additional pions from fragmentation. The D{sub s}{sup -} {yields} {ell}{sup -}{nu}{sub {ell}} events are detected by full or partial reconstruction of the recoiling system DKX{gamma}{ell}. The following results are obtained: {Beta}(D{sub s}{sup -} {yields} {mu}{sup -}{nu}) = (6.02 {+-} 0.38 {+-} 0.34) x 10{sup -3}, {Beta}(D{sub s}{sup -} {yields} {tau}{sup -}{nu}) = (5.00 {+-} 0.35 {+-} 0.49) x 10{sup -2}, and B(D{sub s}{sup -} {yields} e{sup -}{nu}) &lt; 2.8 x 10{sup -4} at 90% C.L., where the first uncertainty is statistical and the second is systematic. The branching fraction measurements are combined to determine the D{sub s}{sup -} decay constant f{sub D{sub s}} …
Date: March 15, 2012
Creator: Benitez, Jose
System: The UNT Digital Library
Neutrino and antineutrino inclusive charged-current cross section measurement with the MINOS near detector (open access)

Neutrino and antineutrino inclusive charged-current cross section measurement with the MINOS near detector

This thesis presents the measurement of energy dependence of the neutrino-nucleon inclusive charged current cross section on an isoscalar target in the range 3-50 GeV for neutrinos and 5-50 GeV energy range for antineutrinos. The data set was collected with the MINOS Near Detector using the wide band NuMI beam at Fermilab. The size of the charged current sample is 1.94 x 10{sup 6} neutrino events and 1.60 x 10{sup 5} antineutrino events. The flux has been extracted using a low hadronic energy sub-sample of the charged current events. The energy dependence of the cross section is obtained by dividing the charged current sample with the extracted flux. The neutrino and antineutrino cross section exhibits a linear dependence on energy at high energy but shows deviations from linear behavior at low energy. We also present a measurement of the ratio of antineutrino to neutrino inclusive cross section.
Date: March 1, 2009
Creator: Bhattacharya, Debdatta & U., /Pittsburgh
System: The UNT Digital Library
Velocity measurements of low Reynolds number tube flow using fiber-optic technology (open access)

Velocity measurements of low Reynolds number tube flow using fiber-optic technology

In 1988 Nielsen started work to measure the spatial variability of the mass flux vector being transported in a porous medium. To measure the spatial variability of the mass flux vector, the spatial variability of its components(velocity, concentration) must be measured. Nielsen was successful in measuring the pore level concentration at many different pores and in verifying the assumption that a nonuniform concentration field exists within the mixing zone between two miscible fluids. However, Nielsen was unable to conduct the necessary pore level velocity measurements needed. Nielsen`s work is being continued and a probe is being developed that will measure both velocity and concentration components at pore level. The probe is essentially the same probe used to make the pore level concentration measurements with added capabilities needed to make the velocity measurements. This probe has several design variables, dealing primarily with the velocity component, that need further investigation. The research presented in this thesis investigates these parameters by performing experiments in a capillary tube. The tube is a controlled system where the velocity of the fluid can be determined from the volumetric flow rate using Poiseuille`s solution for viscous flow. Also, a statistically based relationship between the velocity measured with …
Date: March 1, 1993
Creator: Bianchi, J. C.
System: The UNT Digital Library
The Meson Mass Ratio and Energy Balance in Pi-Mu Decay (open access)

The Meson Mass Ratio and Energy Balance in Pi-Mu Decay

None
Date: March 1, 1954
Creator: Birnbaum, W.
System: The UNT Digital Library
Study of the Delta (1232) Using Double Polarization Asymmetries (open access)

Study of the Delta (1232) Using Double Polarization Asymmetries

An extensive experimental program to measure the spin structure of the nucleus is underway in Hall B at Jefferson Lab using a polarized electron beam incident on a polarized target. Spin degrees of freedom offer the possibility to test, in an independent way, existing models of resonance electro-production. The present analysis selects the Delta{sup +} (1232) in the exclusive channel {rvec p}({rvec e}, e'p)pi{sup 0} from data of the EG1 run period, taken in the Fall of 1998, to extract single and double asymmetries in a Q{sup 2} range from 0.5 to 1.5 GeV{sup 2}/c{sup 2}. Results of the asymmetries are presented as a function of momentum transfer Q{sup 2}. A comparison with the Effective Lagrangian Model by R. Davidson and N. Mukhopadhyay, the unitary isobar model MAID, and the dynamic model by Sato and Lee was performed. The data were found to be generally in good agreement with the models and a x{sup 2} comparison preferred the Sato-Lee model, which is tailored for the Delta (1232) photo- and electro-production. The present results are the first measurement of asymmetries for the exclusive reaction {rvec p}({rvec e}, e'p)pi{sup 0} and will provide new constraints for the models.
Date: March 1, 2002
Creator: Biselli, Angela
System: The UNT Digital Library
AN APPLICATION OF CRITICAL PATH SCHEDULING TO DESIGN ENGINEERING (SANS COMPUTER) (thesis) (open access)

AN APPLICATION OF CRITICAL PATH SCHEDULING TO DESIGN ENGINEERING (SANS COMPUTER) (thesis)

None
Date: March 1, 1965
Creator: Boyd, J.H. Jr.
System: The UNT Digital Library
Development of aerogel-lined targets for inertial confinement fusion experiments (open access)

Development of aerogel-lined targets for inertial confinement fusion experiments

None
Date: March 5, 2013
Creator: Braun, Tom
System: The UNT Digital Library
Layered Double Hydroxides And the Origins of Life on Earth (open access)

Layered Double Hydroxides And the Origins of Life on Earth

Thesis written by a student in the UNT Honors College discussing the origins of life on Earth and how layered double hydroxides were involved.
Date: March 13, 2001
Creator: Brister, Brian
System: The UNT Digital Library
Probabilistic Simulation of Subsurface Fluid Flow: A Study Using a Numerical Scheme (open access)

Probabilistic Simulation of Subsurface Fluid Flow: A Study Using a Numerical Scheme

There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and …
Date: March 1, 1980
Creator: Buscheck, Timothy Eric
System: The UNT Digital Library
CHARGE-EXCHANGE SCATTERING OF NEGATIVE PIONS BY HYDROGEN AT 230,260, 290, 317 AND 371 MeV (open access)

CHARGE-EXCHANGE SCATTERING OF NEGATIVE PIONS BY HYDROGEN AT 230,260, 290, 317 AND 371 MeV

The differential cross section for charge-exchange scattering of negative pions by hydrogen has been observed at 230, 260, 290, 317, and 371 Mev. The reaction was observed by detecting one gamma ray from the {pi}{sup 0} decay with a scintillation-counter telescope.
Date: March 18, 1960
Creator: Caris, John C
System: The UNT Digital Library
Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector (open access)

Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector

We present the search for the lepton flavour violating decay {tau} {yields} lK{sup 0}{sub s} with the BaBar experiment data. This process and many other lepton flavour violating {tau} decays, like {tau} {yields} {mu}{gamma} and {tau} {yields} lll, are one of the most promising channel to search for evidence of new physics. According to the Standard Model and the neutrino mixing parameters, branching fractions are estimated well below 10{sup -14}, but many models of new physics allow for branching fractions values close to the present experimental sensitivity. This analysis is based on a data sample of 469fb{sup -1} collected by BABAR detector at the PEP-II storage ring from 1999 to 2007, equivalent to 431 millions of {tau} pairs. the BABAR experiment, initially designed for studying CP violation in B mesons, has demonstrated to be one of the most suitable environments for studying {tau} decays. The tracking system, the calorimeter and the particle identification of BABAR, together with the knowledge of the {tau} initial energy, allow an extremely powerful rejection of background events that, for this analysis, is better than 10{sup -9}. Being {tau} {yields} lK{sup 0}{sub s} a decay mode without neutrinos, the signal {tau} decay can be fully reconstructed. …
Date: March 20, 2009
Creator: Cenci, Riccardo
System: The UNT Digital Library
Study of the reaction $pi$$sup -$p $Yields$ eta n in the region of the N*(1688) (open access)

Study of the reaction $pi$$sup -$p $Yields$ eta n in the region of the N*(1688)

None
Date: March 25, 1975
Creator: Chaffee, R.B.
System: The UNT Digital Library
Lasershot peening--a means to strengthen metals (open access)

Lasershot peening--a means to strengthen metals

Lasershot peening is an emerging modern process that impresses a compressive stress into the surfaces of metals, improving their operational lifetime. Almost everyone is familiar with taking a strip of metal or a wire and bending it multiple times until it breaks. In this situation, when the metal is bent, the surface of outer radius is stretched into a tensile state. Under tension, any flaw or micro-crack will grow in size with each bending of the metal until the crack grows through the entire strip, breaking it into two pieces. Flexure of metal components occurs in most applications. The teeth of a transmission gear flex as they deliver torque in a vehicle. Springs and valves flex every time they transfer loads. If fatigue failure from flexing occurs in the tooth of a transmission gear of light or heavy vehicles, in a fan blade of a diesel engine, in shock-absorbers or safety-related supporting structures, significant loss of assets and potentially loss of human life occurs. Lasershot peening, better than any other technique, has the potential to extend the fatigue lifetime of metal components. In the process, the laser generates a high intensity shock wave at the surface of the metal, straining …
Date: March 1, 2000
Creator: Chen, H. L.
System: The UNT Digital Library
Signal and noise analysis of a-Si:H radiation detector-amplifier system (open access)

Signal and noise analysis of a-Si:H radiation detector-amplifier system

Hydrogenated amorphous silicon (a-Si:H) has potential advantages in making radiation detectors for many applications because of its deposition capability on a large-area substrate and its high radiation resistance. Position-sensitive radiation detectors can be made out of a 1d strip or a 2-d pixel array of a Si:H pin diodes. In addition, signal processing electronics can be made by thin-film transistors on the same substrate. The calculated radiation signal, based on a simple charge collection model agreed well with results from various wave length light sources and 1 MeV beta particles on sample diodes. The total noise of the detection system was analyzed into (a) shot noise and (b) 1/f noise from a detector diode, and (c) thermal noise and (d) 1/f noise from the frontend TFT of a charge-sensitive preamplifier. the effective noise charge calculated by convoluting these noise power spectra with the transfer function of a CR-RC shaping amplifier showed a good agreement with the direct measurements of noise charge. The derived equations of signal and noise charge can be used to design an a-Si:H pixel detector amplifier system optimally. Signals from a pixel can be readout using switching TFTs, or diodes. Prototype tests of a double-diode readout scheme …
Date: March 1, 1992
Creator: Cho, Gyuseong
System: The UNT Digital Library
Parity non-conserving nuclear force (open access)

Parity non-conserving nuclear force

None
Date: March 1, 1974
Creator: Chou, T.S.
System: The UNT Digital Library
Development of a Text Formatted Under VAX/VMS Operating System (open access)

Development of a Text Formatted Under VAX/VMS Operating System

No matter how extended the use of the computer is, the printed document is still the primary medium for the presentation information, and will continue to be for some time. The use of computing facilities for preparation and production of the document is becoming as prevalent as their use for numeric computation. Commercially, document preparation systems are now a standard facility at research institution, and they have become quite common on each computer program. A conventional document preparation system usually contains two parts: a text editor used to create, enter, update, and maintain the text and control words that comprise the document in its "input" form, and a text formatter used to process that input and produce the final document.
Date: March 1984
Creator: Chow, Perng
System: The UNT Digital Library
Reconciliation (open access)

Reconciliation

The content of my work focused on examining the relationship between certain elements of nature and of human beings and was also based on the question of what true life is. The woodcut process - combined with the other printing techniques such as intaglio, collagraph, and monotype - was adopted as a potentially successful medium for conveying the content of the work. Overlay printing techniques and repeated textures were utilized as well.
Date: March 1996
Creator: Chung, Miok
System: The UNT Digital Library
Expulsion of Carriers from the Double-Barrier Quantum Well and Investigation of Its Spectral and Transport Consequences (open access)

Expulsion of Carriers from the Double-Barrier Quantum Well and Investigation of Its Spectral and Transport Consequences

In this work I investigate the expulsion of carriers from nanostructures using the double-barrier quantum well (DBQW) as an example and discuss manifestations of this effect in the spectrum of the DBQW in absence of bias, and in the tunneling current in presence of bias. Assuming equality of the Fermi energy in all regions of the considered system, I compute the relative density of carriers localized in the DBQW and conclude that a fraction of carriers is expelled from this nanostructure.
Date: March 1992
Creator: Chyla, Wojciech Tadeusz
System: The UNT Digital Library