22 Matching Results

Search Results

Results: 1 - 22
open access

Efficient biased random bit generation for parallel processing

Description: A lattice gas automaton was implemented on a massively parallel machine (the BBN TC2000) and a vector supercomputer (the CRAY C90). The automaton models Burgers equation {rho}t + {rho}{rho}{sub x} = {nu}{rho}{sub xx} in 1 dimension. The lattice gas evolves by advecting and colliding pseudo-particles on a 1-dimensional, periodic grid. The specific rules for colliding particles are stochastic in nature and require the generation of many billions of random numbers to create the random bits necessa… more
Date: September 28, 1994
Creator: Slone, D.M.
Partner: UNT Libraries Government Documents Department
open access

A Study of Selected Properties and Applications of AlMgB14 and Related Composites: Ultra-Hard Materials

Description: This research presents a study of the hardness, electrical, and thermal properties AlMgB{sub 14} containing Al{sub 2}MgO{sub 4} spinel. This research also investigated how much Al{sub 2}MgO{sub 4} spinel consistently forms with AlMgB{sub 14}, if AlMgB{sub 14} materials can be produced by hot isostatic pressing (HIP), what effects TiC and TiB{sub 2} have on this composite material, and the importance of mechanical alloying. Included also is a study of the variation in hardness measurements and h… more
Date: May 28, 2002
Creator: Lewis, Theron L.
Partner: UNT Libraries Government Documents Department
open access

Magnetic spectroscopy and microscopy of functional materials

Description: Heusler intermetallics Mn{sub 2}Y Ga and X{sub 2}MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suite… more
Date: January 28, 2011
Creator: Jenkins, C.A.
Partner: UNT Libraries Government Documents Department
open access

Multicore Architecture-aware Scientific Applications

Description: Modern high performance systems are becoming increasingly complex and powerful due to advancements in processor and memory architecture. In order to keep up with this increasing complexity, applications have to be augmented with certain capabilities to fully exploit such systems. These may be at the application level, such as static or dynamic adaptations or at the system level, like having strategies in place to override some of the default operating system polices, the main objective being to… more
Date: November 28, 2011
Creator: Srinivasa, Avinash
Partner: UNT Libraries Government Documents Department
open access

Structural and magnetic properties of transition metal substituted BaFe{sub 2}As{sub 2} compounds studied by x-ray and neutron scattering

Description: The purpose of my dissertation is to understand the structural and magnetic properties of the newly discovered FeAs-based superconductors and the interconnection between superconductivity, antiferromagnetism, and structure. X-ray and neutron scattering techniques are powerful tools to directly observe the structure and magnetism in this system. I used both xray and neutron scattering techniques on di#11;erent transition substituted BaFe2As2 compounds in order to investigate the substitution dep… more
Date: August 28, 2012
Creator: Kim, Min Gyu
Partner: UNT Libraries Government Documents Department
open access

Fabrication of metal matrix composite by semi-solid powder processing

Description: Various metal matrix composites (MMCs) are widely used in the automotive, aerospace and electrical industries due to their capability and flexibility in improving the mechanical, thermal and electrical properties of a component. However, current manufacturing technologies may suffer from insufficient process stability and reliability and inadequate economic efficiency and may not be able to satisfy the increasing demands placed on MMCs. Semi-solid powder processing (SPP), a technology that comb… more
Date: November 28, 2012
Creator: Wu, Yufeng
Partner: UNT Libraries Government Documents Department
open access

TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

Description: This study focused on creating a new tristructural isotropic (TRISO) coated particle fuel performance model and demonstrating the integration of this model into an existing system of neutronics and heat transfer codes, creating a user-friendly option for including fuel performance analysis within system design optimization and system-level trade-off studies. The end product enables both a deeper understanding and better overall system performance of nuclear energy systems limited or greatly imp… more
Date: November 28, 2011
Creator: Powers, J J
Partner: UNT Libraries Government Documents Department
open access

Suppressed Charmed B Decay

Description: This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{… more
Date: November 28, 2011
Creator: Snoek, Hella Leonie & /Vrije U., Amsterdam
Partner: UNT Libraries Government Documents Department
open access

THE TRIPLE--REGGE VERTEX.

Description: No Description Available.
Date: April 28, 1970
Creator: Misheloff, M. N.
Partner: UNT Libraries Government Documents Department
open access

Time-varying Reeb Graphs: A Topological Framework Supporting the Analysis of Continuous Time-varying Data

Description: I present time-varying Reeb graphs as a topological framework to support the analysis of continuous time-varying data. Such data is captured in many studies, including computational fluid dynamics, oceanography, medical imaging, and climate modeling, by measuring physical processes over time, or by modeling and simulating them on a computer. Analysis tools are applied to these data sets by scientists and engineers who seek to understand the underlying physical processes. A popular tool for anal… more
Date: November 28, 2006
Creator: Mascarenhas, A
Partner: UNT Libraries Government Documents Department
open access

SQUID magnetometry from nanometer to centimeter length scales

Description: The development of Superconducting QUantum Interference Device (SQUID)-based magnetometer for two applications, in vivo prepolarized, ultra-low field MRI of humans and dispersive readout of SQUIDs for micro- and nano-scale magnetometery, are the focus of this thesis.
Date: June 28, 2010
Creator: Hatridge, Michael J.
Partner: UNT Libraries Government Documents Department
open access

Measurement of Beam Current in the Bevatron by Induced Voltages

Description: The Bevatron uses a system of electrodes through which the internal proton beam passes in order to continuously measure the magnitude and radial position of the beam. The bunched circulating beam induces a periodic voltage on the electrodes. This signal is amplified and displayed on an oscilloscope and also converted to direct current for operation of a recorder. Two types of electrode systems are used. The first is a large hollow box to provide beam magnitude signals for specialized monitoring… more
Date: October 28, 1957
Creator: Lavrischeff, J. T.
Partner: UNT Libraries Government Documents Department
open access

Production of Neutral Photopions as a Function of Atomic Weight

Description: Thesis discussing the relative yield of neutral pions from elements in a reaction "as a function of the quantum-limit energy (the maximum energy of the quanta in the bremsstrahlung beam) of the Berkeley synchrotron." Interpretation of the results leads to values for the mean free path for absorption of the neutral pions in nuclear matter.
Date: May 28, 1956
Creator: Anderson, John David
Partner: UNT Libraries Government Documents Department
open access

Encapsulation of Hazardous Wastes Into Agglomerates

Description: The objective of this study was to investigate the feasibility of using the cementitious properties and agglomeration characteristics of coal conversion byproducts to encapsulate and immobilize hazardous waste materials. The intention was to establish an economical way of co-utilization and co-disposal of wastes. In addition, it may aid in the eradication of air pollution problems associated with the fine-powdery nature of fly ash. Encapsulation into agglomerates is a novel approach of treating… more
Date: January 28, 1992
Creator: Guloy, Aida
Partner: UNT Libraries Government Documents Department
open access

Synthesis of higher alcohols from carbon monoxide and hydrogen in a slurry reactor

Description: Higher, i.e. C{sub 2{sup +}}, alcohols are desired as gasoline additives, feedstocks for producing ethers and as alternative fuels for automobiles. In all cases, the backbone branching of an alcohol improves octane rating, which is essential for good engine performance. These types of branched, higher alcohols are the desired products for a process converting synthesis gas, a CO and H{sub 2} mixture, often generated from coal gasification. Based on this premise, promoted ZnCr oxide catalysts ap… more
Date: August 28, 1992
Creator: McCutchen, M. S.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen