ent temperature variation in a thermally orthotropic plate which is subjected to an arbitrary heating rate distribution along one face with all other surfaces being insulated. Dimensionless temperature histories and distributions determined from this solution are presented for the special, but representative, case of a linearly varying heating rate distribution on plates with varying degrees of thermal orthotropy. These results establish quantitatively the value of a material with high planar and low normal thermal conductivities for applications where it is desired to maintain minimum temperatures on the rear or unheated surface of a heat shield when the heated surface is subjected to a very non-uniform heating rate distribution. The applicability of simplifying assumptions in analyzing such a system is discussed. Experimental temperature measurements in a pyrolytic graphite plate heated by an oxyacetylene flame were made to verify the analytical results. Achievement of satisfactory agreement wss found to be dependent upon use of thermal property values differing from those presently available for this material. This is not unusual in that differences in production methods are known to introduce substantial property variations in anisotropic materials such as pyrolytic graphite. (auth)

Mathematical models of the time-dependent behavior of two-phase natural- circulation loops were used to predict the operation and to explain the unusual instability sometimes observed. The initial results obtained for a loop similar to the Univ. of Minnesota loop were used to formulate a more complex and accurate model, and the predicted transient behavior was in close agreement with the experimental results from the Minnesota loop. For a 300psia, high-pressure loop, unstable oscillatory behavior was predicted under certain conditions and stable behavior under others. Closed unstable regions rather than limits were predicted, and the specifications of stability in terms of a single parameter were found to be impossible. The great difference in oscillatory frequencies observed at low and high pressures was found to be due largely to the system geometry. The criterion for the absence of oscillations was found to be similar to one of the criteria for stability of chemical reaction systems. (D.L.C.)

A kinetic model of the primary loop of a multi-pass pressurized water reactor power plant is developed to evaluate, by analog computer techniques, the transient response characteristics under conditions of steam generator load and reactor control rod perturbations. Using the 2-pass 28 Mw(t) SM-2 reactor as a typical plant, transient behavior patterns are illustrated and examined for a variety of load inputs, variations in plant constants, and analog model simplifications. (auth)

In the analysis and evaluation of the role of the elementary school supervisor, the purpose was (1) to investigate relationships which might exist between certain personal and professional background characteristics of elementary school supervisors and the activities in which they engaged, (2) to determine the activities in which elementary school supervisors engaged, (3) to determine emphasis placed upon those activities in which elementary school supervisors engaged, and (4) to evaluate those activities in which elementary school supervisors engaged.

The general purpose of the study was to determine the relationship between college environmental press variables and the attrition characteristics of college freshmen at Southern Methodist University.

The problem of this study was to determine the predictive validity, as measured by multiple R, of two batteries given to beginning college students using various achievement criteria.

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87p. The theory, design techniques, and relative economics are presented for three basically different direct-contact condensation processes involving fluids whose condensed phases are immiscible. In the specific system developed for the study, Aroclor 1248 (Monsanto Chemical Corporation) and steam were used. The processes investigated include the injection, and the induction of steam into a highvelocity stream of Aroclor in the throat section of a Venturi. The bubbling of steam into a low-velocity stream of Aroclor, using a packed tower to artificially increase the surface of contact was also investigated. The induction, injection, pressure drop, and heat-transfer characteristics of a Venturi in direct-contact condensation service were experimentally investigated, and empirical correlations for the performance of the unit are included. The performance of a direct-injection device was also experimentally determined, and correlations obtained. A discussion is included concerning the theoretical development of relations which are used to predict the performance of packed towers in direct-contact condensation service. (auth)

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Thesis submitted to University of Tennessee, Knoxville. Activities in a program to determine the wetting behavior of pure metals such as Au, Ag, Ge, Al, and Cu on solid Be are reported. Results of similar investigations of binary alloys such as Be--Ti, Be-Zr, and Be--Pd are also included. The contact angles of the molten metals on Be as a function of temperature, exposure time, and atmosphere were measured. The solid-liquid interfacial reactions occurring as a function of test temperature and atmosphere were investigated, and the liquid- vapor and internal surface tensions for those systems in which interfacial reactions did not appear to occur were calculated. (J.R.D.)

Experimental determinations of the longitudinal dispersion coefficient and the Peclet number were made for three binary gas systems. The experimental technique involved measuring the dispersion of a step function input to a column packed with glass beads. The diffusional model was employed to obtain the differential equation describing longitudinal dispersion in a packed column. This equation was solved with suitable boundary conditions, and the solution was used in the analysis of the experimental dispersion data. The experimental results show a variation in the Peclet number from 0.1 to 0.6, and in the eddy dispersion coefficient from 0.03 to 1.0 cm/sup 2//sec for the Reynolds number range from 0.03 to 1.0. (auth)

By means of the Mandelstam representation, expressions are obtained for the two-pion-exchange contributions to the higher partial waves of N-N scattering. A set of ten invariant amplitudes is selected, of which each member obeys the Mandelstam representation. Dispersion relations are written for the amplitudes in which the discontinuities are absorptive parts for N-bar-N scattering. By means of the unitarity condition the absorptive parts are expressed as a partial- wave expansion in terms of the pi pi - NN partialwave amplitudes of Frazer and Fulco, except for the contributions of the pole in the pi -N system which are treated exactly in order to ensure better convergence of the partial-wave expansion. The N-N transition amplitudes in the angular-momentum representation are expressed in terms of the invariant amplitudes. (auth)

Carrier recombination and annealing of radioinduced recombination centers were investigated for both n- and ptype Ge. The experimental results are explained by a model in which recombination occurs at 0.36 ev above the valence band in gamma -irradiated, n-type Ge; the position of this level is shifted slightly downward for neutron-irradiated Ge. Trapping levels occur in As-doped Ge (at 0.17 ev above the valence band) which are not present in Sb-doped Ge. For p-type Ge, an energy level present in unirradiated Ge acts as a trapping center. A value for the electron capture cross section of n-type Ge is derived: 7 x 10/ sup -//sup 1//sup 9/ cm/sup 2/. The annealing properties of Sb- and As-doped Ge are very different. A model for the annealing results is given in which irradiation produces three major types of defects: interstitials, vacancies, and vacancy-interstitial pairs. The properties of each defect type are described. Association of vacancies with doping atoms is discussed. (D.L.C.)

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A mass-spectrometric investigation was performed on sulfur vapor in equilibrium with the condensed phase at 120 to 210 gas-cooled C. It was found that, in this temperature range, equilibrium sulfur vapor contains appreciable quantities of S/sub 8/, S/sub 7/, S/sub 6/, and S/sub 5/ only. The sulfur vapor emanated as a small well-collimated molecular beam from a specially constructed source into an ionization chamber which was designed to exclude from analysis any sulfur vapor that had impinged on the walls or the hot electron filament. Essential identical ionization potentials were determined for S/sub 8/ , S/sub 7/, S/sub 6/, and S/sub 5/ of 9.8 0.4 ev. The heat of vaporizati on of S/sub 7/ was calculated to be approximately 2.5 kcal greater than that of S/ sub 8/. Upper limits for S/sub 8/ and S/sub 7/ composition in S vapor at 120 gas- cooled C were determined to be 86% and 14%, respectively. It is proposed thst S/sub 8/ is the vaporizing species, that S/sub 7/, S/sub 6/, and S/sub 5/ result from dissociation of S/sub 8/. and that all four molecules have a ring configuration. (auth)

S>Studies of the separation process known as zone melting were enclosed in 5 to 10 mm glass tubes and pulled through a stationary heater, which generated a liquid zone. The separation increased as the zone travel rate decreased, as the size of the tube increased, and as the difference in liquid density between the belk solid and the freezing interface increased. It was also found that, for vertical tubes, the separation was much greater when the fluid of lower density Between the buld zone and the freezing interface) was on the bottom the When it was on the top. Insertion of an axial thbe or rod of metal or glass into the zone also increased the separation. A correlation was developed which enables estimation of the separation for various - sithations in zone melting, Equations and principles were developed which enable estimation of the thermal requirements for zone melting and a theoretical study of pure diffusional mass transfer in some melting was also made. A general expression for concentration profiles was derived for materials with a constant distribution coefficient and a method for the rapid estimation of these concentration profiles was developed, Numerical results for eutectic-forming systems were obtained, and …

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