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Study of Quasielastic 1p-shell proton Knockout in the {sup 16}O (e,e'p) reaction at Q{sup 2}=0.8 (GeV/c){sup 2}

Description: Coincidence cross sections and the structure functions R{sub L+TT},#2; R{sub T} and R{sub LT} have been obtained for the quasielastic #2;#3;{sup 16}O(#7;e,#2; e'p)#8; reaction with the proton knocked out from the #2;1p{sub 1/2}#2;#2;#4; and #2;1p{sub 3/2}#5;#2;#4; states in perpendicular kinematics. The nominal energy transfer #3;{omega} was 439#11; MeV#4; the nominal Q{sup 2}#4; was 0.8 (#7;GeV/#14;c){sup 2}#8;#4; and the kinetic energy of knocked-#15;out proton was 427#3;#16; MeV. The data wa… more
Date: June 1, 1999
Creator: Gao, Juncai
Partner: UNT Libraries Government Documents Department
open access

Genetic algorithms applied to nonlinear and complex domains

Description: The dissertation, titled ''Genetic Algorithms Applied to Nonlinear and Complex Domains'', describes and then applies a new class of powerful search algorithms (GAS) to certain domains. GAS are capable of solving complex and nonlinear problems where many parameters interact to produce a ''final'' result such as the optimization of the laser pulse in the interaction of an atom with an intense laser field. GAS can very efficiently locate the global maximum by searching parameter space in problems … more
Date: June 1, 1999
Creator: Barash, D & Woodin, A E
Partner: UNT Libraries Government Documents Department
open access

Direct observation of resonance effects in laser cluster interactions

Description: Time resolved dynamics of high intensity laser interactions with atomic clusters have been studied with both theoretical analysis and experiment. A short-pulse Ti:sapphire laser system, which could produce 50 mJ of energy in a 50 fs pulse, was built to perform these experiments. The laser used a novel single grating stretcher and was pumped, in part, by a custom Nd:YLF laser system, including 19 mm Nd:YLF amplifiers. It was found that there is an optimal pulse width to maximize absorption for a… more
Date: June 1, 1999
Creator: Zweiback, J
Partner: UNT Libraries Government Documents Department
open access

Stochastic Characterization of Cast Metal Microstructure

Description: The major goal of this work is to provide a means to characterize the final structure of a metal that has solidified from a melt. The thermally controlled solidification of a binary alloy, nucleated at isolated sites, is described by the evolution of a probability distribution function (PDF). The relevant equation required for propagating the PDF is developed with variables for grain size and distance to nearest neighbor. The phenomena of nucleation, growth, and impingement of the grains are di… more
Date: June 1, 1999
Creator: Steinzig, M.
Partner: UNT Libraries Government Documents Department
open access

Three-dimensional numerical modeling of the influence of faults on groundwater flow at Yucca Mountain, Nevada

Description: Numerical simulations of groundwater flow at Yucca Mountain, Nevada are used to investigate how the faulted hydrogeologic structure influences groundwater flow from a proposed high-level nuclear waste repository. Simulations are performed using a 3-D model that has a unique grid block discretization to accurately represent the faulted geologic units, which have variable thicknesses and orientations. Irregular grid blocks enable explicit representation of these features. Each hydrogeologic layer… more
Date: June 1, 1999
Creator: Cohen, Andrew J. B.
Partner: UNT Libraries Government Documents Department
open access

Mechanism of constitution liquid film migration

Description: Liquid film migration (LFM) in liquid phase sintering classically involves a large metastable liquid volume adjacent to solid, and migration occurs at an isolated solid-liquid (S-L) interface. Constitutional liquid film migration (CLFM), discovered in alloy 718, has major characteristics similar to those of LFM, except that the metastable liquid is from the constitutional liquation of precipitates on the grain boundary. The similarity between LFM and CLFM has led to the theory that coherency la… more
Date: June 1, 1999
Partner: UNT Libraries Government Documents Department
open access

A new mechanical characterization method for thin film microactuators and its application to NiTiCi shape memory alloy

Description: In an effort to develop a more full characterization tool of shape memory alloys, a new technique is presented for the mechanical characterization of microactuators and applied to SMA thin films. A test instrument was designed to utilize a spring-loaded transducer in measuring displacements with resolution of 1.5 pm and forces with resolution of 0.2 mN. Employing an out-of-plane loading method for freestanding SMA thin films, strain resolution of 30{mu}{epsilon} and stress resolution of 2.5 MPa… more
Date: June 1, 1999
Creator: Seward, K P
Partner: UNT Libraries Government Documents Department
open access

Scaling supernova hydrodynamics to the laboratory

Description: Supernova (SN) 1987A focused attention on the critical role of hydrodynamic instabilities in the evolution of supernovae. To test the modeling of these instabilities, we are developing laboratory experiments of hydrodynamic mixing under conditions relevant to supernovae. Initial results were reported in J. Kane et al., Astrophys. J.478, L75 (1997) The Nova laser is used to shock two-layer targets, producing Richtmyer-Meshkov (RM) and Rayleigh-Taylor (RT) instabilities at the interfaces between … more
Date: June 1, 1999
Creator: Kane, J.O.
Partner: UNT Libraries Government Documents Department
open access

Genetic algorithms applied to nonlinear and complex domains

Description: The dissertation, titled ''Genetic Algorithms Applied to Nonlinear and Complex Domains'', describes and then applies a new class of powerful search algorithms (GAS) to certain domains. GAS are capable of solving complex and nonlinear problems where many parameters interact to produce a final result such as the optimization of the laser pulse in the interaction of an atom with an intense laser field. GAS can very efficiently locate the global maximum by searching parameter space in problems whic… more
Date: June 1, 1999
Creator: Barash, D & Woodin, A E
Partner: UNT Libraries Government Documents Department
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