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The Specific Heat of Dysprosium Metal Between 0.4 and 4 K

Description: Submitted to Illinois Inst. of Tech., Chicago. A He/sup 3/ cryostat was built to measure the specific heat of rare earth metals which have a component, at low temperatures, attributable to the electrons in the incomplete 4f shell. The specific heat of dysprosium from 0.4 to 4.2 deg K was measured. Pertinent theories about specific heats are outlined. The apparatus included the cryostat, vacuum and He/sup 3/ systems, calorimeter, carbon thermometer, heater, and magnetic thermometer. The experime… more
Date: August 1, 1962
Creator: Guenther, R. A.
Partner: UNT Libraries Government Documents Department
open access

Response of Shortgrass Plains Vegetation to Chronic and Seasonally Administered Gamma Radiation

Description: In order to determine the effect of radiation on the structure of native shortgrass plains vegetation, an 8750 Ci 137Cs source was installed on the Central Plains Experimental Range near Nunn, Colorado; The experimental area was divided into 6 treatment sectors, a control, 2 sectors for chronic exposure (irradiation initiated April 1969 and continuing as of August 1971), and one each for spring, summer and late fall seasonal semi-acute (30 day), exposures which were administered during April, J… more
Date: August 1, 1971
Creator: Fraley, L. Jr.
Partner: UNT Libraries Government Documents Department
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The Angular Distribution of Fission Fragments From the Fast Neutron-Induced Fission of U-234

Description: Submitted to Univ. of Tennessee, Knoxville. The fast neutron-induced fission cross section of U/sup 234/ was measured from threshold to 4-Mev neutron energy. A maximum of 1.26 barns was found at 850 kev followed by a minimum of 1.10 barns at 8050 kev. The angular ani-sotropy of the fragment distribution was measured for neutron energies from 400 kev to 4 Mev. Extrema in the ratio sigma /sub f//( sigma /sub f(90 deg ) were found at 500, 850, and 1050 kev; the distribution at 500 kev showing a ma… more
Date: August 27, 1962
Creator: Lamphere, R. W.
Partner: UNT Libraries Government Documents Department
open access

Investigations of the R5(SixGe1-x)4 Intermetallic Compounds by X-Ray Resonant Magnetic Scattering

Description: The XRMS experiment on the Gd{sub 5}Ge{sub 4} system has shown that, below the Neel temperature, T{sub N} = 127 K, the magnetic unit cells is the same as the chemical unit cell. From azimuth scans and the Q dependence of the magnetic scattering, all three Gd sites in the structure were determined to be in the same magnetic space group Pnma. The magnetic moments are aligned along the c-axis and the c-components of the magnetic moments at the three different sites are equal. The ferromagnetic sla… more
Date: August 18, 2008
Creator: Tan, Lizhi
Partner: UNT Libraries Government Documents Department
open access

Search for new physics in the Compact Muon Solenoid (CMS) experiment and the response of the CMS calorimeters to particles and jets

Description: A Monte Carlo study of a generic search for new resonances beyond the Standard Model (SM) in the CMS experiment is presented. The resonances are axigluon, coloron, E{sub 6} diquark, excited quark, W{prime}, Z{prime}, and the Randall-Sundrum graviton which decay to dijets. The dijet resonance cross section that the CMS can expect to discover at a 5{sigma} significance or to exclude at 95% confidence level for integrated luminosities of 100 pb{sup -1}, 1 fb{sup -1}, and 10 fb{sup -1} is evaluated… more
Date: August 1, 2008
Creator: Gumus, Kazim Ziya & Tech., /Texas
Partner: UNT Libraries Government Documents Department
open access

Type Ia supernova rate studies from the SDSS-II Supernova Study

Description: The author presents new measurements of the type Ia SN rate from the SDSS-II Supernova Survey. The SDSS-II Supernova Survey was carried out during the Fall months (Sept.-Nov.) of 2005-2007 and discovered {approx} 500 spectroscopically confirmed SNe Ia with densely sampled (once every {approx} 4 days), multi-color light curves. Additionally, the SDSS-II Supernova Survey has discovered several hundred SNe Ia candidates with well-measured light curves, but without spectroscopic confirmation of typ… more
Date: August 1, 2008
Creator: Dilday, Benjamin
Partner: UNT Libraries Government Documents Department
open access

Inductively Coupled Plasma: Fundamental Particle Investigations with Laser Ablation and Applications in Magnetic Sector Mass Spectrometry

Description: Particle size effects and elemental fractionation in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) are investigated with nanosecond and femtosecond laser ablation, differential mobility analysis, and magnetic sector ICP-MS. Laser pulse width was found to have a significant influence on the LA particle size distribution and the elemental composition of the aerosol and thus fractionation. Emission from individual particles from solution nebulization, glass, and a pressed… more
Date: August 18, 2008
Creator: Saetveit, Nathan Joe
Partner: UNT Libraries Government Documents Department
open access

QCD fits to neutrino-iron structure functions at NuTeV

Description: This thesis presents a new determination of {Lambda}{sub QCD} from Next-to-Leading Order QCD fits to the Q{sup 2} dependence of neutrino-iron structure functions. This is the first measurement of {Lambda}{sub QCD} which uses a theoretical model that fully accounts for heavy quark production. Compared with previous neutrino measurements, the result has improved understanding of the largest systematic uncertainties on the muon and hadron energy scales. These improvements lead to one of the most p… more
Date: August 1, 2006
Creator: Radescu, Voica A. & U., /Pittsburgh
Partner: UNT Libraries Government Documents Department
open access

Error-Induced Beam Degradation in Fermilab's Accelerators

Description: In Part I, three independent models of Fermilab's Booster synchrotron are presented. All three models are constructed to investigate and explore the effects of unavoidable machine errors on a proton beam under the influence of space-charge effects. The first is a stochastic noise model. Electric current fluctuations arising from power supplies are ubiquitous and unavoidable and are a source of instabilities in accelerators of all types. A new noise module for generating the Ornstein-Uhlenbeck (… more
Date: August 1, 2007
Creator: Yoon, Phil S.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the W boson helicity in top quark decays

Description: A measurement of the fraction, f{sup +}, of right-handed W bosons produced in top quark decays is presented. This analysis is based on a sample corresponding to an integrated luminosity of 370 pb{sup -1}, collected by the D0 detector at the Fermilab Tevatron p{bar p} Collider at {radical}s = 1.96 TeV. The helicity angle, {theta}*, is reconstructed for each lepton. f{sup +} is determined by comparing the cos {theta}* distribution from the data with that for the expected background and signal for… more
Date: August 1, 2007
Creator: Gmyrek, Bryan David
Partner: UNT Libraries Government Documents Department
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Search for Higgs bosons decaying into tau pairs in ppbar collisions at D0

Description: A search for neutral Higgs bosons decaying into tau pairs is presented using data in p{bar p} collisions at {radical}s = 1.96 TeV. One of the tau leptons is identified via its decay into an electron or muon and the other via its decay into a hadronic final state. The data, corresponding to an integrated luminosity of around 1.0 fb{sup -1}, were collected with the D0 detector at the Fermilab Tevatron collider between April 2002 and February 2006. No significant excess of events above the backgro… more
Date: August 1, 2008
Creator: Owen, Mark A.
Partner: UNT Libraries Government Documents Department
open access

Evidence for single top quark production using Bayesian neural networks

Description: We present results of a search for single top quark production in p{bar p} collisions using a dataset of approximately 1 fb{sup -1} collected with the D0 detector. This analysis considers the muon+jets and electron+jets final states and makes use of Bayesian neural networks to separate the expected signals from backgrounds. The observed excess is associated with a p-value of 0.081%, assuming the background-only hypothesis, which corresponds to an excess over background of 3.2 standard deviation… more
Date: August 1, 2007
Creator: Kau, Daekwang
Partner: UNT Libraries Government Documents Department
open access

Design of a boron neutron capture enhanced fast neutron therapy assembly

Description: The use of boron neutron capture to boost tumor dose in fast neutron therapy has been investigated at several fast neutron therapy centers worldwide. This treatment is termed boron neutron capture enhanced fast neutron therapy (BNCEFNT). It is a combination of boron neutron capture therapy (BNCT) and fast neutron therapy (FNT). It is believed that BNCEFNT may be useful in the treatment of some radioresistant brain tumors, such as glioblastoma multiform (GBM). A boron neutron capture enhanced fa… more
Date: August 1, 2006
Creator: Wang, Zhonglu & Tech, /Georgia
Partner: UNT Libraries Government Documents Department
open access

A Measurement of the Top Quark Mass in the Dilepton Decay Channel at CDF II

Description: The top quark, the most recently discovered quark, is the most massive known fundamental fermion. Precision measurements of its mass, a free parameter in the Standard Model of particle physics, can be used to constrain the mass of the Higgs Boson. In addition, deviations in the mass as measured in different channels can provide possible evidence for new physics. We describe a measurement of the top quark mass in the decay channel with two charged leptons, known as the dilepton channel, using da… more
Date: August 1, 2006
Creator: Jayatilaka, Bodhitha A.
Partner: UNT Libraries Government Documents Department
open access

Novel Bioplastics and biocomposites from Vegetable Oils

Description: Polymeric materials have been prevalent in our everyday lives for quite a long time. Most of today's polymeric materials are derived from nonrenewable petroleum-based feedstocks. Instabilities in the regions where petroleum is drilled, along with an increased demand in petroleum, have driven the price of crude oil to record high prices. This, in effect, increases the price of petroleum-based polymeric materials, which has caused a heightened awareness of renewable alternatives for polymeric fee… more
Date: August 18, 2008
Creator: Henna, Phillip H.
Partner: UNT Libraries Government Documents Department
open access

Synthesis and Characterization of Smart Block Copolymers for Biomineralization and Biomedical Applications

Description: Self-assembly is a powerful tool in forming structures with nanoscale dimensions. Self-assembly of macromolecules provides an efficient and rapid pathway for the formation of structures from the nanometer to micrometer range that are difficult, if not impossible to obtain by conventional lithographic techniques [1]. Depending on the morphologies obtained (size, shape, periodicity, etc.) these self-assembled systems have already been applied or shown to be useful for a number of applications in … more
Date: August 18, 2008
Creator: Kanapathipillai, Mathumai
Partner: UNT Libraries Government Documents Department
open access

Study of the Rare Decay K(L) ---> pi0 gamma gamma at KTeV

Description: The authors study on the rare decay K{sub L} {yields} {pi}{sup 0}{gamma}{gamma}, measure a{sub V}, and branching ratio by analyzing 96, 97 and 99 data. The measurements were taken by KTeV at Fermi National Accelerator Laboratory. After all cuts, they have 1982 K{sub L} {yields} {pi}{sup 0}{gamma}{gamma} candidate. The background level is estimated as 30%. K{sub L} {yields} {pi}{sup 0}{gamma}{gamma} branching ratio is measured as (1.29 {+-} 0.03(stat) {+-} 0.04(sys)) x 10{sup -6}. By using D'Amb… more
Date: August 1, 2007
Creator: Wang, Jianbo
Partner: UNT Libraries Government Documents Department
open access

Effects of Substrate and Co-Culture on Neural Progenitor Cell Differentiation

Description: In recent years the study of stem and progenitor cells has moved to the forefront of research. Since the isolation of human hematopoietic stem cells in 1988 and the subsequent discovery of a self renewing population of multipotent cells in many tissues, many researchers have envisioned a better understanding of development and potential clinical usage in intractable diseases. Both these goals, however, depend on a solid understanding of the intracellular and extracellular forces that cause stem… more
Date: August 18, 2008
Creator: Jones, Erin Boote
Partner: UNT Libraries Government Documents Department
open access

Determination of NAD+ and NADH level in a Single Cell Under H2O2 Stress by Capillary Electrophoresis

Description: A capillary electrophoresis (CE) method is developed to determine both NAD{sup +} and NADH levels in a single cell, based on an enzymatic cycling reaction. The detection limit can reach down to 0.2 amol NAD{sup +} and 1 amol NADH on a home-made CE-LIF setup. The method showed good reproducibility and specificity. After an intact cell was injected into the inlet of a capillary and lysed using a Tesla coil, intracellular NAD{sup +} and NADH were separated, incubated with the cycling buffer, and q… more
Date: August 18, 2008
Creator: Xi, Wenjun
Partner: UNT Libraries Government Documents Department
open access

Diagnostics of the Fermilab Tevatron using an AC dipole

Description: The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for th… more
Date: August 1, 2008
Creator: Miyamoto, Ryoichi
Partner: UNT Libraries Government Documents Department
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Structural and Electronic Investigations of Complex Intermetallic Compounds

Description: In solid state chemistry, numerous investigations have been attempted to address the relationships between chemical structure and physical properties. Such questions include: (1) How can we understand the driving forces of the atomic arrangements in complex solids that exhibit interesting chemical and physical properties? (2) How do different elements distribute themselves in a solid-state structure? (3) Can we develop a chemical understanding to predict the effects of valence electron concentr… more
Date: August 18, 2008
Creator: Ko, Hyunjin
Partner: UNT Libraries Government Documents Department
open access

Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

Description: The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline sol… more
Date: August 18, 2008
Creator: Chen, Qian
Partner: UNT Libraries Government Documents Department
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