Multispectral Thermal Imagery and Its Application to the Geologic Mapping of the Koobi Fora Formation, Northwestern Kenya (open access)

Multispectral Thermal Imagery and Its Application to the Geologic Mapping of the Koobi Fora Formation, Northwestern Kenya

None
Date: February 15, 2006
Creator: Green, Mary K.
System: The UNT Digital Library
A Study of Muon Ionization Cooling at MICE (open access)

A Study of Muon Ionization Cooling at MICE

A Neutrino Factory based on a high-energy muon storage-ring is proposed to study neutrino oscillation with high precision. An emittance reduction of muon beam by ionization cooling, which has never been demonstrated in practice, is one of the critical issues for Neutrino Factory. The international Muon Ionisation Cooling Experiment (MICE) is the first experiment to verify an effect of the ionization cooling with muons. MICE will measure a change in transverse emittance of approximately 10% with a precision of ±0.1%. In order to meet the requirements, muon trackers based on 350 μm diameter scintillating fibers have been proposed. The construction of such trackers is a very challenging task and some innovative techniques are needed to realize, since there have been no trackers made with such a small diameter of scintillating fibers in the world. Upstream and downstream SciFi trackers have been successfully constructed with the international collaboration of UK, US and Japan by 2008. Both of the trackers have been tested with cosmic-rays at the RAL by 2009, at which high tracking efficiencies more than 90% are measured for both trackers. It is also confirmed that by collecting the misalignments found in both of the trackers, the requirements for the …
Date: February 1, 2010
Creator: Sakamoto, Hideyuki
System: The UNT Digital Library
Development of the OSO-6 high-energy neutron detector and correlation of measured solar neutron fluxes to solar flares (open access)

Development of the OSO-6 high-energy neutron detector and correlation of measured solar neutron fluxes to solar flares

Thesis. The development of a directional high energy (20 to 160 MeV) neutron detector which was flown to satellite altitudes (500 km; circular equatorial orbit) in the NASA Orbiting Solar Observatory (OSO-6) in August 1969 is described. Both the angle of incidence and the energy of the neutron are determined by a proton-recoil telescope (Pilot B scintillation plastic) which provides the source for proton-recoils and defines the dE/dX versus E method for particle identification and energy determination. The telescope is embedded in a scintillation plastic guard counter envelope which eliminates the unwanted charged particle background as well as recoil protons (electrons) whose energies and direction do not satisfy neutron (gamma-ray) detection requirements, respectively. Results from a Monte Carlo calculation indicate that the overall average efficiency within an average angular acceptance of about 29 deg (FWHM) is approximately (2.25 plus or minus 0.113) x 10/sup -4/. The inflight calibration procedure, the main frame data bit error analysis, and the method for determining the orientation of the detector axis in the spacecraft spin plane are described. Results indicate a discrepancy in the measured (0.461 x 10/sup -2/ plus or minus 0.254 x 10/sup -2/ n/cm/sup 2/sec) and theoretical (2 to 70 n/cm/ …
Date: February 1, 1974
Creator: Young, F.
System: The UNT Digital Library
Scintillation response of lithium fluoride (open access)

Scintillation response of lithium fluoride

Thesis. Lithium fluoride crystals, with TlF added to the charge, were prepared by the Bridgman- Stockbarger method. The scintillation response to photon energies between 25 and 1250 keV for these crystals and a commercially prepared LiF (Ti) crystal was studied. The response of the LiF (Ti) crystal was compared to the response of an NE109 scintillator at 1250 keV. The dose response of the LiF (Ti) crystal was evaluated over the energy range 25 to 1250 keV. The absorption and emission spectra of the LiF (Ti) crystal are discussed. A historical review precedes the discussion. (auth)
Date: February 11, 1974
Creator: Kloepping, R.J.
System: The UNT Digital Library
Aerosol trace element analysis using neutron activation and x-ray fluorescence (open access)

Aerosol trace element analysis using neutron activation and x-ray fluorescence

None
Date: February 1, 1974
Creator: Roberts, N.J.
System: The UNT Digital Library
Thermodynamic study of phase stability in the thorium--copper equilibrium system (open access)

Thermodynamic study of phase stability in the thorium--copper equilibrium system

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Date: February 1, 1975
Creator: Bailey, D. M.
System: The UNT Digital Library
Fracture toughness of thin beryllium sheet (open access)

Fracture toughness of thin beryllium sheet

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Date: February 28, 1974
Creator: Tardiff, G.E. Jr.
System: The UNT Digital Library
A Proposal for Determining the Electro-Magnetic Form Factor of the Pion (open access)

A Proposal for Determining the Electro-Magnetic Form Factor of the Pion

The possibility of measuring the electromagnetic form factor of the pion by extrapolation of the cross section for e/sup -/ + p 1100 deg C are n + The effects of /sup +/ + e/sup -/ was investigated. The method is based on the existence of a pole in the electropionproduction scattering amplitude as a function of the invariant momentum-transfer of the nucleon. The residue of this pole is the pion form factor multiplied by a known coefficient. Since the pole lies slightly outside the physical region of the invariant momentum transfer, an extrapolation of the experimental data is required. An approximate calculation of the electropion-production cross section was made in order to estimate the experimental accuracy necessary for a significant extrapolation. Accuracy is required which is an order of magnitude better than that achieved at present in similar experiments. (auth)
Date: February 1, 1959
Creator: Frazer, William Robert
System: The UNT Digital Library
Superconductivity and the Kondo effect in quench-condensed films containing cerium (open access)

Superconductivity and the Kondo effect in quench-condensed films containing cerium

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Date: February 1, 1975
Creator: Delfs, R.J.
System: The UNT Digital Library
An Analytic Tool to Investigate the Effect of Binder on the Sensitivity of HMX-Based Plastic Bonded Explosives in the Skid Test (open access)

An Analytic Tool to Investigate the Effect of Binder on the Sensitivity of HMX-Based Plastic Bonded Explosives in the Skid Test

This project will develop an analytical tool to calculate performance of HMX based PBXs in the skid test. The skid-test is used as a means to measure sensitivity for large charges in handling situations. Each series of skid tests requires dozens of drops of large billets. It is proposed that the reaction (or lack of one) of PBXs in the skid test is governed by the mechanical properties of the binder. If true, one might be able to develop an analytical tool to estimate skid test behavior for new PBX formulations. Others over the past 50 years have tried to develop similar models. This project will research and summarize the works of others and couple the work of 3 into an analytical tool that can be run on a PC to calculate drop height of HMX based PBXs. Detonation due to dropping a billet is argued to be a dynamic thermal event. To avoid detonation, the heat created due to friction at impact, must be conducted into the charge or the target faster than the chemical kinetics can create additional energy. The methodology will involve numerically solving the Frank-Kamenetskii equation in one dimension. The analytical problem needs to be bounded …
Date: February 1, 2005
Creator: Hayden, D. W.
System: The UNT Digital Library
Three-body Forces in Photoreactions on 3He (open access)

Three-body Forces in Photoreactions on 3He

We have measured the three-body photobreakup of {sup 3}He with the tagged photon beam and the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility, in the photon energy range between 0.35 GeV and 1.55 GeV. This measurement constitutes a wide-ranging survey of two- and three-body processes in the gamma{sup 3}He {yields} ppn reaction channel, thanks to the high statistics and large kinematic coverage obtained with the CLAS. Total and partially integrated differential cross sections for the full ppn data set and for selected kinematics were extracted and are compared to theoretical predictions of Laget (up to 1.0 GeV). At low photon energies, the calculations are generally in fair agreement with the data. The comparison shows evidence of strong contributions of three-body absorption mechanisms, especially in the star kinematics, a symmetric configuration of the three final-state nucleons. Mostly the effects of two-body absorption mechanisms are se en, as expected, in the pp-pair-breakup kinematics, where the neutron does not participate in the reaction. The quasi-two-body breakup shows angular distributions consistent with preliminary gamma{sup 3}He --> pd results, extracted from our experiment. The ratio of cross sections for the star configuration and for the two-body kinematics, shows …
Date: February 1, 2003
Creator: Niccolai, Silvia
System: The UNT Digital Library
Principles and techniques for designing precision machines (open access)

Principles and techniques for designing precision machines

This thesis is written to advance the reader's knowledge of precision-engineering principles and their application to designing machines that achieve both sufficient precision and minimum cost. It provides the concepts and tools necessary for the engineer to create new precision machine designs. Four case studies demonstrate the principles and showcase approaches and solutions to specific problems that generally have wider applications. These come from projects at the Lawrence Livermore National Laboratory in which the author participated: the Large Optics Diamond Turning Machine, Accuracy Enhancement of High- Productivity Machine Tools, the National Ignition Facility, and Extreme Ultraviolet Lithography. Although broad in scope, the topics go into sufficient depth to be useful to practicing precision engineers and often fulfill more academic ambitions. The thesis begins with a chapter that presents significant principles and fundamental knowledge from the Precision Engineering literature. Following this is a chapter that presents engineering design techniques that are general and not specific to precision machines. All subsequent chapters cover specific aspects of precision machine design. The first of these is Structural Design, guidelines and analysis techniques for achieving independently stiff machine structures. The next chapter addresses dynamic stiffness by presenting several techniques for Deterministic Damping, damping designs that …
Date: February 1, 1999
Creator: Hale, L C
System: The UNT Digital Library
Structural Analysis of Shipping Casks, Vol. 9. Energy Absorption Capabilities of Plastically Deformed Struts Under Specified Impact Loading Conditions (open access)

Structural Analysis of Shipping Casks, Vol. 9. Energy Absorption Capabilities of Plastically Deformed Struts Under Specified Impact Loading Conditions

The purpose of this investigation was to determine the energy absorption characteristics of plastically deformed inclined struts under impact loading. This information is needed to provide a usable method by which designers and analysts of shipping casks for radioactive or fissile materials can determine the energy absorption capabilities of external longitudinal fins on cylindrical casks under specified impact conditions. A survey of technical literature related to experimental determination of the dynamic plastic behavior of struts revealed no information directly applicable to the immediate problem, especially in the impact velocity ranges desired, and an experimental program was conducted to obtain the needed data. Mild-steel struts with rectangular cross sections were impacted by free-falling weights dropped from known heights. These struts or fin specimens were inclined at five different angles to simulate different angles of impact that fins on a shipping cask could experience under certain accident conditions. The resisting force of the deforming strut was measured and recorded as a function of time by using load cells instrumented with resistance strain gage bridges, signal conditioning equipment, an oscilloscope, and a Polaroid camera. The acceleration of the impacting weight was measured and recorded as a function of time during the latter portion …
Date: February 19, 2001
Creator: Davis, F. C.
System: The UNT Digital Library
The Effects Of Structural Setting On The Azimuthal Velocities Of Blast Induced Ground Motion In Perlite (open access)

The Effects Of Structural Setting On The Azimuthal Velocities Of Blast Induced Ground Motion In Perlite

A series of small scale explosive tests were performed during the spring of 1994 at a perlite mine located near Socorro, NM. The tests were designed to investigate the azimuthal or directional relationship between small scale geologic structures such as joints and the propagation of explosively induced ground motion. Three shots were initiated within a single borehole located at ground zero (gz) at depths varying from the deepest at 83 m (272 ft) to the shallowest at 10 m (32 ft). The intermediate shot was initiated at a depth of 63 m (208 ft). An array of three component velocity and acceleration transducers were placed in two concentric rings entirely surrounding the single shot hole at 150 and 300 azimuths as measured from ground zero. Data from the transducers was then used to determine the average propagation velocity of the blast vibration through the rock mass at the various azimuths. The rock mass was mapped to determine the prominent joint orientations (strike and dip) and the average propagation velocities were correlated with this geologic information. The data from these experiments shows that there is a correlation between the orientation of prominent joints and the average velocity of ground motion. It …
Date: February 1, 1995
Creator: Beattie, Susan G.
System: The UNT Digital Library
Polarized crystal absorption spectra for dibromo(ethylenediamine)platinum(II) (open access)

Polarized crystal absorption spectra for dibromo(ethylenediamine)platinum(II)

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Date: February 1, 1973
Creator: Kroening, R. F.
System: The UNT Digital Library
Diffusion of lanthanum in molten uranium (open access)

Diffusion of lanthanum in molten uranium

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Date: February 1, 1973
Creator: Hovingh, J.
System: The UNT Digital Library
Delayed neutron emission from mass-separated fission products (open access)

Delayed neutron emission from mass-separated fission products

Thesis. Delayed neutron characteristics of six fission product nuclides were determined using a mass separator operated on-line with a nuclear reactor. Beta-decay half-lives were- measured using neutron multiscaling techniques for the precursors /sup 88/Br, /sup 89/Br, /sup 98/Kr, /sup 93/Kr, /sup 137/I, and / sup 138/I. The observed half-lives were 16.52 plus or minus .17 seconds, respectively.. Energy spectra were measured for delayed neutrons emitted in the beta-decays of /sup 17/N, /sup 137/I, /sup 93/Kr , and /sup 93/Rb. The spectra of neutron emissions in the mass 93 parentdaughter decay chain were observed using a moving tape collector to effect isobaric separation. Two different types of /sup 3/He- filled neutron spectrometer were used to determine the spectra; a proportional counter with risetime discrimination electronics, and a high resolution ionization chamber. The measured delayed, neutron spectra using both detector types are presented, and the results compared, where possible, with other reported measurements. (auth)
Date: February 1, 1974
Creator: Norman, J.H.
System: The UNT Digital Library
Effect of hydrogen on the creep properties of vanadium, niobium, and molybdenum (open access)

Effect of hydrogen on the creep properties of vanadium, niobium, and molybdenum

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Date: February 1, 1975
Creator: Mather, J.C.
System: The UNT Digital Library
Static and dynamic properties of systems with multipole interactions and internal dynamic structure (open access)

Static and dynamic properties of systems with multipole interactions and internal dynamic structure

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Date: February 1, 1973
Creator: Mandell, M.J.
System: The UNT Digital Library
Critical field curves for the ThU alloy system. (open access)

Critical field curves for the ThU alloy system.

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Date: February 1, 1973
Creator: Watson, H L
System: The UNT Digital Library
The Effect of Pressure on Boiling Density in Multiple Rectangular Channels (open access)

The Effect of Pressure on Boiling Density in Multiple Rectangular Channels

None
Date: February 1, 1956
Creator: Marchaterre, J. F.
System: The UNT Digital Library
The neutron electric form factor to Q² = 1.45 (GeV/c)² (open access)

The neutron electric form factor to Q² = 1.45 (GeV/c)²

The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the …
Date: February 1, 2004
Creator: Plaster, Bradley
System: The UNT Digital Library
Search for the Standard Model Higgs Boson in the $WH \to \ell \nu b\bar{b}$ Channel in 1.96-TeV Proton-Antiproton Collisions (open access)

Search for the Standard Model Higgs Boson in the $WH \to \ell \nu b\bar{b}$ Channel in 1.96-TeV Proton-Antiproton Collisions

We have searched for the Standard Model Higgs boson in the WH → lvbb channel in 1.96 TeV pp collisions at CDF. This search is based on the data collected by March 2009, corresponding to an integrated luminosity of 4.3 fb<sup>-1</sup>. The W H channel is one of the most promising channels for the Higgs boson search at Tevatron in the low Higgs boson mass region.
Date: February 1, 2010
Creator: Nagai, Yoshikazu
System: The UNT Digital Library
Growth of single crystals of hexagonal nickel sulfide (open access)

Growth of single crystals of hexagonal nickel sulfide

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Date: February 1, 1973
Creator: Trumpy, F.D.
System: The UNT Digital Library