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Spectroscopy of transition metal species in rare gas matrices. I. Vanadium metal. II. Sulfides. III. Carbonyl complexes. IV. Dinitrogen complexes. V. Homonuclear diatomic compounds
None
Date:
October 1, 1975
Creator:
DeVore, T. C.
System:
The UNT Digital Library
Formal analysis of name accessing in programming languages. [R]
None
Date:
October 1, 1975
Creator:
Smith, C. L.
System:
The UNT Digital Library
Temperature dependence of resistivity of thin film samples of chalcogenide glasses
None
Date:
October 1, 1975
Creator:
Kulkarni, A. K.
System:
The UNT Digital Library
Magnetic excitations above the critical temperature
None
Date:
October 1, 1975
Creator:
Swanson, P. A.
System:
The UNT Digital Library
CARBON-13 NMR STUDIES OF LIQUID CRYSTALS
High resolution, proton decoupled {sup 13}C nmr are observed for a series of neat nematic liquid crystals, the p-alkoxyazoxybenzenes, and a smectic-A liquid crystal, diethylazoxydibenzoate in a magnetic field of 23 kG. The (uniaxial) order parameters S = <P{sub 2}(cos{theta})> are found to be about 0.4 and 0.9 for the nematic and smectic-A phase respectively at the clearing points. The order parameter increases with decreasing temperature in the nematic phase but is constant, or nearly so, with temperature in the smectic-A phase. In the nematic series studied, the ordering exhibits an even-odd alternation along the series and qualitative agreement with a recent theory due to Marcelja is found. In both phases, the spectra show that the molecule rotates rapidly about its long axis. Tentative conclusions about molecular conformational motion and {sup 14}N spin relaxation are presented for both nematic and smectic-A phases. In the smectic-A phase, the sample is rotated about an axis perpendicular to H{sub 0} and the resulting spectra are discussed. The theory of observed chemical shifts in liquid crystals is treated in an appendix. Equations are derived which relate the nmr spectra of liquid-crystals to the order parameters. A model for the smectic-C phase due to Luz …
Date:
June 1, 1975
Creator:
Allison, Stuart
System:
The UNT Digital Library
Synthesis and characterization of metal--metal bonded dimers of tantalum and tungsten
A search for innovative synthetic routes to new metal-metal bonded metal-halide clusters resulted in isolation of two completely independent dimeric species. The syntheses and characterizations of Ta/sub 2/X/sub 6/(SC/sub 4/H/sub 8/)/sub 3/ (X = Cl, Br) and ((n-C/sub 3/H/sub 7/)/sub 4/N)/sub 2/(W/sub 2/Br/sub 9/) followed entirely different experimental routes, yet occasionally similar properties linked the two projects. (auth)
Date:
December 1, 1975
Creator:
Templeton, J. L.
System:
The UNT Digital Library
Simulation and control synthesis for a pulse column separation system for plutonium--uranium recovery
None
Date:
May 1, 1975
Creator:
McCutcheon, E. B.
System:
The UNT Digital Library
Molecular beam kinetics
The design of a crossed molecular beam ''supermachine'' for neutral-- neutral collisions is discussed. The universal electron bombardment ionizer, mass filter, and ion detection system of the detector, the supersonic nozzle sources, the differential pumping arrangement for the sources and detector, the time-of-flight detection of scattered products, and the overall configuration of the apparatus are described. The elastic scattering of two systems, CH$sub 4$ + Ar and NH$sub 3$ + Ar, has been measured using the supermachine with two supersonic nozzle sources. The rainbow structure and the interference oscillations are seen in each system. The best fit to the data was found using a Morse--Spline--Van der Waals (MSV) potential. The three potential parameters epsilon, r/sub m/, and $beta$ were found to be 2.20(+-0.04) x 10$sup -14$ ergs, 3.82(+-0.04)A, and 7.05 +- 0.20 for CH$sub 4$ + Ar, and 2.21(+-0.04) x 10$sup - 14$ ergs 3.93 (+-0.05)A, and 8.45 +- 0.30 for NH$sub 3$ + Ar. A new phenomenon in crossed molecular beams of condensation of a molecule on a cluster to form a complex was observed. A bromine molecule condensed on clusters of chlorine (Cl$sub 2$)/sub chi/ and ammonia (NH$sub 3$)/sub chi/. The value of chi for measurements in these …
Date:
November 1, 1975
Creator:
Behrens, R. Jr.
System:
The UNT Digital Library
Extraction of metal ions with N, N-disubstituted amides
None
Date:
July 1, 1975
Creator:
Orf, G.M.
System:
The UNT Digital Library
Peripheral nucleon--antinucleon production by 13 GeV/c pions
None
Date:
April 30, 1975
Creator:
Dulude, R. S. & Gaidos, J. A.
System:
The UNT Digital Library
Thermodynamic study of phase stability in the thorium--copper equilibrium system
None
Date:
February 1, 1975
Creator:
Bailey, D. M.
System:
The UNT Digital Library
Superconductivity and the Kondo effect in quench-condensed films containing cerium
None
Date:
February 1, 1975
Creator:
Delfs, R.J.
System:
The UNT Digital Library
Radiochemical studies of some low- and medium-energy nuclear reactions produced by accelerated tritons, deuterons, and protons
None
Date:
January 1, 1975
Creator:
Casella, V.R.
System:
The UNT Digital Library
Pi-meson absorption on the deuteron
None
Date:
January 1, 1975
Creator:
Goplen, B.
System:
The UNT Digital Library
High temperature deformation behavior of cemented carbide cutting tools
None
Date:
January 1, 1975
Creator:
Baldoni, J.G. II
System:
The UNT Digital Library
Effect of hydrogen on the creep properties of vanadium, niobium, and molybdenum
None
Date:
February 1, 1975
Creator:
Mather, J.C.
System:
The UNT Digital Library
Study of the reaction $pi$$sup -$p $Yields$ eta n in the region of the N*(1688)
None
Date:
March 25, 1975
Creator:
Chaffee, R.B.
System:
The UNT Digital Library
Quantities of actinides in nuclear reactor fuel cycles
None
Date:
April 1, 1975
Creator:
Ang, K.P.
System:
The UNT Digital Library
Single atom imaging in high resolution electron microscopy
None
Date:
1975~
Creator:
Chiu, W.
System:
The UNT Digital Library
Multiconfiguration self-consistent field method for many-electron systems and its application to the dissociation of ethylene
None
Date:
October 1, 1975
Creator:
Cheung, L. M.
System:
The UNT Digital Library
Electroreflectance of single crystal metals
None
Date:
December 1, 1975
Creator:
Furtak, T. E.
System:
The UNT Digital Library
Isotope Separation by Laser Deflection of an Atomic Beam
None
Date:
February 1, 1975
Creator:
Bernhardt, A. F.
System:
The UNT Digital Library
Cooling of interstellar formaldehyde by collision with helium: an accurate quantum mechanical calculation
In order to test a collisional pumping model as a mechanism for cooling the 6 cm and 2 cm doublets of interstellar formaldehyde, a quantum mechanical scattering calculation is performed. To obtain the intermolecular interaction between H$sub 2$CO($sup 1$A$sub 1$) and He($sup 1$S) two calculations are performed, a Hartree-Fock (HF) potential surface and a configuration interaction (CI) surface. A basis set of better than ''triple zeta plus polarization'' quality is used to compute the HF portion of the potential energy surface. This portion is highly anisotropic and has a slight attraction arising from induction effects at intermolecular separations around 9 a.u. The HF surface is modified through a series of CI calculations. Correlation is found to have little effect in the strongly anisotropic repulsive region of the interaction potential but dominates the well and long-range regions. The maximum well depth is attained for in-plane approaches of He and lies in the range 35-40$sup 0$K for arbitrary theta at center of mass separation of 7.5 a.u. The entire surface is fit to a spherical harmonic expansion to facilitate scattering applications. (auth)
Date:
August 1, 1975
Creator:
Garrison, B. J.
System:
The UNT Digital Library
Single particle inclusive spectra resulting from the collision of relativistic protons, deuterons, alpha particles, and carbon ions with nuclei
None
Date:
May 1, 1975
Creator:
Papp, J.
System:
The UNT Digital Library