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COMPUTER SIMULATION OP FRANK LOOP CONTRAST IN FIELD IONIMAGES

Description: A computer model for simulation of the image contrast caused by Frank dislocation loops in field ion tips of fcc materials is presented. The model is based on the shell model for ion image simulation, whereas the displacement field of Frank loops is computed from the exact displacement equation for a closed dislocation loop in an isotropically elastic continuum. A method for taking surface effects into account by superposition of the displacement field of an image loop is introduced. The result… more
Date: September 1, 1973
Creator: Stolt, Kaj Gunnar
Partner: UNT Libraries Government Documents Department
open access

Analysis and Development of FACE Automatic Apparatus for Rapid Identification of Transuranium Isotopes

Description: A description of and operating manual for the FACE Automatic Apparatus has been written along with a documentation of the FACE machine operating program, to provide a user manual for the FACE Automatic Apparatus. In addition, FACE machine performance was investigated to improve transuranium throughput. Analysis of the causes of transuranium isotope loss was undertaken both chemical and radioactive. To lower radioactive loss, the dynamics of the most time consuming step of the FACE machine, the … more
Date: September 1, 1978
Creator: Sebesta, E.H.
Partner: UNT Libraries Government Documents Department
open access

Structure and elevated temperature properties of ferritic alloys strengthened by intermetallic compounds

Description: Thesis. An investigation was conducted to develop high-temperature 1Ta-- 6Cr, 1Ta--7Cr, and 1Ta-7Cr--0.5 Mo alloys using a dispersion of the Laves phase in a noncarbon-containing, body-centeredcubic iron matrix. An understanding and application of basic principles of materials science and the use of large amounts of information available in the literature were instrumental in the development of Fe-- Ta-- Cr alloys of the investigation. The phase transformations that occurred in the alloys, and … more
Date: September 1, 1973
Creator: Bhandarkar, M.D.
Partner: UNT Libraries Government Documents Department
open access

Climb of Dislocations in Magnesium Oxide Single Crystals

Description: The wave like pattern, observed in dislocation dipoles of uniform spacing during annealing, which starts from the ends of the dipole and gets damped toward the centre, has been attributed to controlled vacancy migration. A theory has been set-up to give activation energy for the process, 60,700 + 2,000 cal/mole. This value has been compared with an independent study of pipe diffusion, in which a prismatic loop inside the foil is connect to both surfaces of the foil by screw dislocation.
Date: September 1, 1970
Creator: Narayan, Jagdish
Partner: UNT Libraries Government Documents Department
open access

Application of generalized classical trajectories in nuclear physics

Description: A new semi-classical method, the so-called uniform semiclassical approximation, is described briefly and then applied to two nuclear physics problems. The basic features of this method are that the dynamics of the problem is treated completely classically (that is, one solves classical equations of motion), but the quantum mechanical superposition principle is retained by evaluating a phase along the classical trajectory and adding probability amplitudes for indistinguishable processes rather t… more
Date: September 1, 1975
Creator: Leser, H.M.
Partner: UNT Libraries Government Documents Department
open access

Numerical investigation of the pulsed NF3 + H2 chemical laser using a model which includes rotational relaxation and semi-classical laser equations

Description: Waveforms and population distributions have been calculated by a numerical model and compared with experiment for an electric-discharge-initiated, pulsed NF$sub 3$ + H$sub 2$ chemical laser. The model treats each vibrational- rotational state separately, allowing rotational relaxation between adjacent states as well as vibrational relaxation and lasing according to P-branch selection rules. Calculated waveforms agree with experiment and show several features not seen when rotational equilibrium… more
Date: September 1, 1975
Creator: Creighton, J.R.
Partner: UNT Libraries Government Documents Department
open access

Quantum electrodynamics with the spear magnetic detector

Description: One makes a study of quantum electrodynamic processes which are present at the SPEAR colliding beam magnetic detector. We begin by describing the experiment performed by the SLAC-LBL collaboration and the results concerning the strong interaction. Then the interactions e$sup +$e$sup -$ $Yields$ e$sup +$e$sup -$ and e$sup +$e$sup -$ $Yields$ $mu$$sup +$$mu$$sup -$ are considered along with their third-order radiative corrections. These events, previously used to determine new limits for cutoff p… more
Date: September 1, 1975
Creator: Zipse, J. E.
Partner: UNT Libraries Government Documents Department
open access

Far infrared spectroscopy of solids. I. Impurity states in Al$sub 2$O$sub 3$. II. Electron-hole droplets in Ge

Description: Far infrared Fourier transform spectroscopy was used to study the low lying vibronic states of Mn$sup 3+$ in Al$sub 2$O$sub 3$ and the plasma absorption of electron-hole droplets in Ge. The transmission of Mn-doped samples of Al$sub 2$O$sub 3$ was measured in the frequency range from 3 to 30 cm$sup -1$ in applied magnetic fields up to 50 kG. Absorption lines were observed due to both ground and excited state transitions. Polarization measurements established that these absorption lines were due… more
Date: September 12, 1975
Creator: Aurbauch, R.L.
Partner: UNT Libraries Government Documents Department
open access

Determination of the K/sub L/$sup 0$ $Yields$ $pi$$sup -$$mu$$sup +$$nu$/ sub $mu$/ form factor xi(q$sup 2$) by muon polarization measurements

Description: The polarization of the muon in the decay K$sup 0$/sub L/ $Yields$ $pi$$sup -$$mu$$sup +$$nu$/sub $mu$/ was measured as a function of q$sup 2$, the four-momentum transferred to the lepton pair. The kinematic information was used to compute the polarization expected on the basis of various assumed values of the form factor xi(q$sup 2$). By comparing the interpolated curve of the polarization as a function of xi(q$sup 2$) to the experimentally measured polarization, one has determined xi(q$sup 2$… more
Date: September 1, 1975
Creator: Shen, G.
Partner: UNT Libraries Government Documents Department
open access

Vibrational inelasticity in H$sub 2$ collisions with He and Li$sup +$

Description: The partially averaged version of classical S-matrix theory was applied to three-dimensional collisions of H$sub 2$ with He and Li$sup +$. For H$sub 2$- Li$sup +$, cross-sections for the de-excitation of H$sub 2$ from (n$sub 1$,j$sub 1$) = (1,0) to the ground vibrational manifold were computed at a total energy of 1.2 eV and compared to previously done coupled channel calculations of Schaefer and Lester. The agreement is very good. For H$sub 2$-He, the Kutzelnigg- Tsapline interaction potential… more
Date: September 1, 1975
Creator: Raczkowski, A.W.
Partner: UNT Libraries Government Documents Department
open access

Process development studies for the production of. beta. -glucosidase from Aspergillus phoenicis

Description: This work is concerned with the production of ..beta..-glucosidase from Aspergillus phoenicis for use in the enzymatic hydrolysis of cellulose. Kinetic growth data indicate that two distinct periods of growth exist. The observed growth kinetics result from a biochemical differentiation of the filament which is independent of the substrate concentration. The optimum temperature for cell mass and ..beta..-glucosidase production was found to be 30/sup 0/C. The optimum pH for ..beta..-glucosidase p… more
Date: September 1, 1978
Creator: Howell, M. J. & Wilke, C. R.
Partner: UNT Libraries Government Documents Department
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