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CARBON AND DEUTERIUM NUCLEAR MAGNETIC RESONANCE IN SOLIDS

Description: In Chapter I we present the results on a study of cross polarization dynamics, between protons and carbon-13 in adamantane, by the direct observation of the dilute, carbon-13, spins. These dynamics are an important consideration in the efficiency of proton enhancement double-resonance techniques and they also provide good experimental models for statistical theories of cross relaxation. In order to test these theories we present a comparison of the experimental and theoretical proton dipolar fluctuation correlation time {tau}{sub c}, which is experimentally 110 {+-} 15 {micro}sec and theoretically 122 {micro}sec for adamantane. These double resonance considerations provide the background for extensions to deuterium and double quantum effects discussed in Chapter II. In Chapter II an approach to high resolution nmr of deuterium in solids is described. The m = 1 {yields} -1 transition is excited by a double quantum process and the decay of coherence Q({tau}) is monitored. Fourier transformation yields a deuterium spectrum devoid of quadrupole splittings and broadening. If the deuterium nuclei are dilute and the protons are spin decoupled, the double-quantum spectrum is a high resolution one and yields information on the deuterium chemical shifts {Delta}{omega}. The relationship Q({tau}) {approx} cos 2{Delta}{omega}{tau} is checked and the technique is applied to a single crystal of oxalic acid dihydrate enriched to {approx} 10% in deuterium. The carboxyl and the water deuterium shifts are indeed resolved and the anisotropy of the carboxyl shielding tensor is estimated to be {Delta}{sigma} = 32 {+-} 3 ppm. A complete theoretical analysis is presented. The extension of cross relaxation techniques, both direct and indirect, to proton-deuterium double resonance is also described. The m = 1 {yields} -1 double quantum transition and the m = {+-} 1 {yields} 0 single quantum transitions may all be polarized and we present the derivation of the Hartmann-Hahn cross polarization ...
Date: July 1, 1976
Creator: Shattuck, Thomas Wayne
Partner: UNT Libraries Government Documents Department

Spectra of $gamma$-rays from capture of 2 eV to 9 x 10$sup 4$ eV neutrons by $sup 181$Ta

Description: Using new experimental techniques, the spectra of $gamma$-rays from the capture of neutrons by $sup 181$Ta were measured at the Livermore 100-MeV linac for neutrons from 2 eV to 9 x 10$sup 4$ eV with a (Ge(Li)-NaI) three-crystal spectrometer. Individual primary $gamma$-ray lines were resolved to 1778-keV excitation in $sup 182$Ta. Neutron resonances were resolved to 200-eV neutron energy. Data analysis techniques and codes were developed to extract positions and intensities of resolved transitions from the large data matrices accumulated in this experiment. Techniques were developed to unfold the unresolved $gamma$- ray spectra using the simple response of the three-crystal spectrometer. The resolved transition data were used to place 110 states with spin and parity assignments in the $sup 182$Ta level diagram below 1780-keV excitation. A set of 1240 E1 transition strengths were analyzed to extract 1.38 +- 0.11 degrees of freedom for the most likely chisquared fit to the distribution of widths. The E1 strength function was extracted for E/sub gamma/ = 4 to 6 MeV and compared with previous results. The $gamma$-ray spectra for E/sub gamma/ = 1.5 to 6.1 MeV were unfolded for neutron energy groups between 20 and 9 x 10$sup 4$ eV. Below 5-MeV $gamma$-ray energy no dependence of the spectral shape on neutron energy was observed. (30 figures, 4 tables) (auth)
Date: April 30, 1976
Creator: Stelts, M.L.
Partner: UNT Libraries Government Documents Department

Use of variational techniques for the estimation of neutron detection efficiency

Description: The neutron detection efficiency is a parameter required in the measurement of reactivity by the modified source technique. The direct solution of the detection efficiency at a perturbed state is costly. To solve for this, a particular variational functional, the Lewins' type variational functional, is presented. The functional is a ratio of two other functionals, each dealing with a reaction rate. The evaluation of this particular functional was done by treating the numerator and the denominator functionals separately. This leads to three flux equations, one for forward flux, and two for adjoint fluxes. The advantages of this formulation over, and the equivalence of this formulation to, the conventional functional presented in the literature are described in detail. The flexibility of the proposed functional is demonstrated by using it to estimate the detection efficiency with four different methods: variational interpolation, conventional variational, variational extrapolation, and multi- reference-state variational. Results are presented for one-dimensional and two- dimensional problems. All results are compared with direct calculations. In all cases, the results show that the variational interpolational method and the multi- reference-state variational method are efficient and practically acceptable.
Date: February 1, 1976
Creator: Lin, S.; Robinson, J.C. & Flanagan, G.F.
Partner: UNT Libraries Government Documents Department

A catalogue of American Victorian chairs and sofas at Dallas Old City Park restoration village, January 1, 1975

Description: This catalogue was done to help justify the historical significance of the furnishing collections destined for use in the restoration of Old City Park. Organized according to substyles, the catalogue contains data collected on each entry and is illustrated by color slides. A brief account of the American Victorian Period precedes these entries.
Date: May 1976
Creator: Burgess, Sue Irene
Partner: UNT Libraries

Iterative solution of the diffusion and P$sub 1$ finite element equations

Description: A method for obtaining solutions to the time-independent Boltzmann neutron transport equation on triangular grids with nonorthogonal boundaries and anisotropic scattering is developed. A functional is obtained from the canonical form of the multigroup transport equation. The angular variable is then removed by expanding the functional in spherical harmonics, retaining only the first two moments and limiting the anisotropic scattering to be linear. The finite element method is then implemented by using quadratic Lagrange-type interpolating polynomials to span the spatial domain. The resultant set of coupled linear equations is then solved iteratively. The applicability of convergence acceleration techniques developed for the finite difference method is tested and implemented where appropriate. Finally, a number of numerical experiments are performed to evaluate the performance of the proposed method. The results are compared to results obtained by various established methods. In all cases, agreement is excellent. 16 figures, 7 tables. (auth)
Date: February 1, 1976
Creator: Tomlinson, E.T.; Robinson, J.C. & Vondy, D.R.
Partner: UNT Libraries Government Documents Department

Édouard Batiste's Symphonie militaire (1845): edition and commentary

Description: Symphonie Militaire is a three movement work for twelve solo wind instruments composed by Édouard Batiste (1820-1876), a professor at the Paris Conservatoire and organist. The composition is scored for flute, two oboes, two B-flat clarinets, two bassoons, E-flat trumpet with valves, two F-horns with valves, trombone, and B-flat ophicleide.
Date: May 1976
Creator: Smialek, William
Partner: UNT Libraries

A distributed logic memory with two-dimensional access, as applied to a highly parallel processor

Description: Although more sophisticated designs of associative memories are not yet economically practical, with the dynamic advances in integrated circuitry currently taking place, the day appears not long off for an economical sophisticated associative memory to become a reality. This describes a general outline of a sophisticated DLM, but it also describes the actual logic involved in a building a working model. The design process involves formulating a set of commands sufficient to perform the desired algorithms, developing the logic necessary to implement these commands, and finally constructing a working model to test the logic.
Date: May 1976
Creator: Redwine, William V.
Partner: UNT Libraries

Lateral eye movement as a function of cognitive mode in a Spanish bilingual population

Description: Reflective eye movementa as a function of cognitive nodes were studied in English speaking and Spanish bilingual populations (N=20). A total of 40 questions were asked with the initial, lateral eye movement recorded. Questions consisted of 20 verbal-mathematical type intended to elicit right-eye movement and 20 spatial questions intended to elicit left-eye movement. A significant difference in responses was found dependent on the type of questions asked (F=114.3421,p<.001). No significant differences were obtained between the two groups.
Date: May 1976
Creator: Endrizzi, Ernest
Partner: UNT Libraries

Institutionalized versus non-institutionalized mildly retarded populations: determination and comparison, based on Rotter's personal control theory, and a test of interpersonal distance

Description: The problem with which this study was concerned was that of evaluating and comparing of locus of control scores and interpersonal distance among the institutionalized and non-institutionalized mildly retarded populations. The hypothetical assumptions specifically stated that the institutionalized retardates will be more externally oriented, will show a greater interpersonal distance towards stimuli with no specific expectancies
Date: May 1976
Creator: Moazami, Manoutchehr
Partner: UNT Libraries

Proton--proton interactions at 200 and 300 GeV/c

Description: The reactions pp $Yields$ pp $pi$$sup +$pi$sup -$ and pp $Yields$ pp$pi$$sup +$$pi$$sup -$$pi$$sup +$$pi$$sup -$ at 200 and 300 GeV/c were investigated using the Fermilab 30-inch hydrogen bubble chamber and downstream wide-gap spark chambers. This analysis is based upon approximately 9500 4- pronged and 6-pronged events. The cross sections were consistent with pomeron dominance for these reactions. The final state pp $pi$$sup +$$pi$$sup -$ is dominated by single diffractive dissociation, whose features are quite similar to those observed at low energy. A strong signal for double excitation was seen in the pp $pi$$sup +$$pi$$sup -$$pi$$sup +$$pi$$sup -$ final state and pomeron factorization was found to be satisfied. In the pp $pi$$sup +$$pi$$sup -$ final state, 66 events passed the criterion of double pomeron exchange defined by D. M. Chew. However, these events were found to be severely contaminated by diffractive events. The two-particle exclusive azimuthal correlations agreed well with the prediction of a photostatistical model. (auth)
Date: January 1, 1976
Creator: Ogino, F.
Partner: UNT Libraries Government Documents Department

Electromagnetic form factors of hadrons

Description: A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, $omega$, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated. (auth)
Date: January 1, 1976
Creator: Zidell, V.S.
Partner: UNT Libraries Government Documents Department

Gamma-ray decay schemes for $sup 93$Kr, $sup 93$Rb, and $sup 93$Sr

Description: A study of the gamma-ray de-excitation following the beta decays of $sup 93$Kr, $sup 93$Rb, and $sup 93$Sr using the TRISTAN on-line separator facility is reported. Gamma-ray singles and gamma-gamma coincidence measurements were made using Ge(Li) detectors. Of the 162 gamma rays observed in the decay of $sup 93$Sr, 143, representing more than 99 percent of the total gamma-ray intensity observed, were placed in a level scheme containing 36 levels. For the decay of $sup 93$Rb, 243 gamma rays were observed, of which 231 are placed in a level scheme consisting of 74 levels. This again represents a placement of over 99 percent of the total gamma-ray intensity measured. In the case of the $sup 93$Kr decay approximately 98.5 percent of the observed gamma-ray intensity has been accounted for by the proposed level scheme. This results from the placement of 203 of the 217 gamma rays assigned to this decay in a level scheme comprising 56 levels. Beta-branching for these decays were determined from transition intensity balances. Spin and parity assignments were proposed, whenever possible, on the basis of gamma-ray transition probabilities and deduced log ft values. A comparison is made with the available reaction data for the $sup 93$Y level scheme. In all cases an attempt has been made to explain some of the levels in terms of the nuclear shell model and decay systematics. 18 figures, 20 tables, 68 references. (auth)
Date: January 1, 1976
Creator: Bischof, C.J.
Partner: UNT Libraries Government Documents Department

High temperature vaporization and thermodynamic study of the scandium-- sulfur system

Description: Results of studies on the stoichiometry, structure, vaporization behavior, and thermodynamic properties of the Sc--S system are reported. The thermodynamic results for the stability of ScS(s) are compared with reported results for other transition-metal and rare-earth monosulfides. Various models are discussed in regard to their ability to describe the bonding in these refractory solids. (JRD)
Date: January 1, 1976
Creator: Tuenge, R.T.
Partner: UNT Libraries Government Documents Department

Self-diffusion of Co$sup 60$ in crystals of Co$nu$sub 1-x/O

Description: Tracer self-diffusion coefficients were measured as functions of temperature and deviations from stoichiometry. The arc-transfer technique of crystal growth was found to produce crystal of Co/sub 1-x/O of essentially the same purity as the starting Co rod, and the quality was comparable to commercially available crystals grown by Verneuil process. Measurements at x = 0.005 in Co/sub 1-x/O showed the Co tracer self-diffusion coefficient to be D = 3.88 x 10$sup -4$ exp (--31600 +- 2400/RT) cm$sup 2$/s between 1037 and 1350$sup 0$C. This activation energy is in agreement with measurements made in air, if proper compensation is made for the effect of variation in stoichiometry. Measurements on crystals having deviations between 0.002 and 0.008 at 1150$sup 0$C showed the diffusion coefficient to depend on p/sub O$sub 2$/ as D = 9.74 x 10$sup -9$ p/sub O$sub 2$//sup 1/(3.59)/ cm$sup 2$/s, where p/sub O$sub 2$/ varied between 10$sup -2$.$sup 5$ and 10$sup -0$.$sup 25$ atm. Comparison with thermogravimetric and electrical conductivity measurements confirms that the defects responsible for Co diffusion in the range of temperature and p/sub O$sub 2$/ of this investigation are singly ionized cobalt vacancies. The Co tracer self-diffusion coefficients in single crystals are nearly identical to those in polycrystalline Co/sub 1-x/O. 53 references, 29 fig, 6 tables (DLC)
Date: January 1, 1976
Creator: Rahman, S. F.
Partner: UNT Libraries Government Documents Department