Niobium foils of moderate purity were examined for the morphology of dislocations or defect clusters in the deformed or neutron-irradiated state by transmission electron microscopy. New evidence has been found for the dissociation of screw dislocations into partials on the (211) slip plane according to the Crussard mechanism: (a/2) (111) ..-->.. (a/3) (111) + (a/6) (111).

Dissertation discussing the results of experiments to study the behavior of superconductors under light illumination.

The problem was to identify the differences in attitudes toward physical activity of students and faculty within a health, physical education, and recreation professional preparation program.

This investigation was concerned with the effects of electromyographic biofeedback on the muscular tension of patients diagnosed in a particular personality state. These personality traits were manic, agitated, depressed, and a comparison group.

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 …

Favorable judgment of a work of art, or of a man, usually means that the work of art, or a record of the man, will be preserved for future generations to judge for themselves. An unfavorable judgment may result in a richly deserved obscurity or an irreplaceable loss, unless favorable circumstances combine to preserve the evidence for a more perspicacious generation. One can be forgiven if he distrusts history's judgment; mistakes which have been corrected are legion (the case of J. S. Bach comes most vividly to mind) and skepticism is warranted unless or until the facts are available for confirmation. It is difficult to explain the paucity of information about Jacques-Christophe Naudot, Not that he is another J. S. Bach; neither Fleury, who made the first serious effort to revive interest in his music in the early 1920's, nor Ruf, who has done much in this regard recently, nor this writer makes any such claim. He does not, however, deserve the obscurity that has been his lot. If his music is not always profound, it nevertheless has both intrinsic and historical value, and some of his works reveal considerable contrapuntal skill. It may be that Naudot stood in the …

The magnetic properties of quenched and annealed powder specimens of MnPt were investigated using x-ray diffraction, magnetization measurements and neutron diffraction techniques. Thin films of MnPt were prepared by rf sputtering techniques and the films were investigated by x-ray diffraction and magnetization measurements. The powder specimens of MnPt were found to be typically antiferromagnetic in an L1/sub 0/ structure with Mn atoms occupying the (001) planes. The Mn moments were antiparallel to their nearest neighbors in the (001) planes. The atomic moment of Mn is (4.1 +- .2) ..mu../sub B/ for the annealed specimens and (3.9 +- .2) ..mu../sub B/ for the quenched specimens. Neutron data failed to determine whether or not Pt carries a moment. Assuming a moment associated with the Pt atoms, the maximum value is 0.2 ..mu../sub B/ per atom. The quenched specimens contained small ferromagnetic regions probably with a composition of 18-32 at. percent Mn. The sputtered films of MnPt were highly disordered in all but one specimen, which was amorphous. The films were ferromagnetic with the deduced Mn moment of (3.0 +- .3) ..mu../sub B/ per atom, which may not represent the true value because the films were not entirely ferromagnetic.

A detailed interpretation is presented of E-field ratio telluric, bipole-dipole resistivity mapping, and dipole-dipole resistivity data obtained in the course of geophysical exploration of the Leach Hot Springs area of Grass Valley, Nevada. Several areas are singled out as being worthy of further investigation of their geothermal potential. Comparison of the three electrical exploration techniques indicates that: the bipole-dipole resistivity mapping method is the least useful; the dipole-dipole resistivity method can be very useful, but is, for practical purposes, exceptionally expensive and difficult to interpret; the E-field ratio telluric method can be a highly successful reconnaissance technique for delineating structures and relating the resistivities of different regions within the survey area.

Four sialon-type materials using volcanic ash as a raw material were characterized and some of their properties were determined. The M3 and M4 materials were identified as ..beta../sup 1/--Si/sub 3/N/sub 4/ sialons; their principal constituent is silicon. The M2 material was identified as a 15R-A1N polytype sialon whose principal constituent is aluminum. The M1 material is a mixture of the two types. An overview of results showing the general structural formulae and the relative order of the materials with respect to various properties as determined by the investigation is presented. It is concluded that of the materials tested, the M2 material shows the most promise as a candidate for meeting some of the current needs for high-temperature materials. It is also concluded that more research is needed in order to explain the low resistance of these materials to thermal shock since their coefficients of thermal expansion are relatively low.

The polarized absorption spectra for K/sub 2/PtBr/sub 4/ . 2H/sub 2/O, (N(C/sub 2/H/sub 5/)/sub 4/)/sub 2/PtBr/sub 6/, and Mo/sub 2/(O/sub 2/CCH/sub 2/NH/sub 3/)/sub 4/(SO/sub 4/)/sub 2/ . 4H/sub 2/O have been recorded at 300 and 15/sup 0/K. In K/sub 2/PtBr/sub 4/ . 2H/sub 2/O the bands at 24,000 and 27,000 cm/sup -1/ in both a- and b-polarizations appear to be vibronically induced. The energy spacing of the vibrational structure was noted to be somewhat higher at 180 cm/sup -1/ than for the analogous structure of K/sub 2/PtBr/sub 4/. The presence of a Pt/sub 2/Br/sub 6//sup 2 -/ impurity gave rise to red sections, which evidently were due to the electron transfer, Pt(IV)/reverse arrow/Pt(II), occurring in c-polarization. Very weak spin-forbidden bands were observable in all three polarizations below 23,500 cm/sup -1/. In the crystal spectra of (N(C/sub 2/H/sub 5/)/sub 4/)/sub 2/Pt/sub 2/Br/sub 6/ the transitions were defined with respect to the three molecular axes of the Pt/sub 2/Br/sub 6//sup 2 -/ ion. Excited states were assigned under the D/sub 2//sub h/ point group symmetry of the ion. The delocalization of the d electrons gave rise to strongly enhanced intensities for both spin-forbidden and spin-allowed d/reverse arrow/d transitions. The M/reverse arrow/L charge-transfer …

We report the development of the composite superconducting transition edge bolometer. The temperature sensitive element is an aluminum strip evaporated onto the sapphire substrate. A bismuth film evaporated on the reverse side of the substrate is used to absorb the submillimeter radiation. The noise limitation of the bolometer is calculated. The fabrication and measured performance are described. The best electrical NEP (noise-equivalent-power) obtained is (1.7 {+-} 0.1) x 10{sup -15} WHz{sup -1/2} at 2 Hz at an operating temperature of 1.27 K. This NEP is within a factor of 2 of the thermal noise limit. The effective absorptivity of the bismuth film is measured to be 0.47 {+-} 0.05, and the corresponding detectivity D* is calculated to be (1.1 {+-} 0.1) x 10{sup 14} cm w{sup -1}Hz{sup 1/2}. Suggestions are made for further improvements in sensitivity. The current-dependent noise in thin metal films at the superconducting transition has been further investigated. The measured noise power spectrum of the tin film on sapphire substrate at the superconducting transition is compared with the cosine transforms of the decay curves obtained from step-function and {delta}-function thermal perturbations. The nature of the noise driving term is found to be a random current flowing inside …

A special hydriding system was designed and constructed to satisfy conditions for hydriding niobium. This system controlled the temperature and hydrogen atmosphere surrounding the niobium while ultrasonic measurements were recorded. Ultrasonic wave velocities were determined by measurement of the times for ultrasonic pulses to transit and then echo through known dimensions of test specimens. The method which was employed is commonly known as the pulse-echo-overlap method. This study confirmed the general trends of earlier investigations. In this study C' continued to decrease and C/sub 44/ continued to increase up to 4.69 atomic percent hydrogen which is the maximum concentration which has yet been examined. In the case of the niobium-hydrogen system the Snoek effect may well be a contributory factor to the decrease of C' with increasing hydrogen concentration. However, crystallographic considerations preclude this effect from contributing a concentration dependence to C/sub 44/ or B. The observation of the present work implies that other factors must also be contributing to the overall behavior.

The potential for contamination of groundwater by organic pollutants leached from in-situ spent shale was studied in a series of laboratory leaching experiments. Both batch-mode and continuous-flow column experiments were conducted to study the leaching phenomenon. Experimental variables included retorting characteristics of spent shale, leaching time, initial quality of leach water, temperature of leach water, and particle size of spent shale. Several unique samples of spent shale were examined during the eaching experiments, including spent shale samples produced during combustion retorting, inert gas retorting, and combustion retorting employing recycle gas. The solid-phase organic carbon content of spent shale samples ranged from 0.2 to 3.9 percent by weight. Leachate derived from the batch-mode experiments was analyzed for organic carbon, organic nitrogen, phenols, and acid/base/netral fractions. The highest levels of organic carbon were detected in leachate derived from spent shale produced during either inert gas retorting or combstion retorting using recycle gas. The highest levels of phenols were observed in leachate obtained from spent shale produced during inert gas retorting; significant levels of organic nitrogen were also detected in various leachate samples. The most predominant organic fraction measured in leachate samples was the neutral fraction associated with spent shale produced during inert …

Results are reported from an investigation of correlations between molecular structural parameters of selected organophosphorus insecticides and their corresponding toxic effectiveness. The crystal and molecular structures of azinphos-methyl, emidithion, and tetrachlorvinphos were determined via three-dimensional x-ray analysis. Acetylcholinesterase (AChE) in nerve cells was identified as the target for organophosphorus insecticides.

This paper contains a detailed interpretation of E-field ratio telluric, bipole-dipole resistivity mapping, and dipole-dipole resistivity data obtained in the course of geophysical exploration of the Leach Hot Springs area of Grass Valley, Nevada. Several areas are singled out as being worthy of further investigation of their geothermal potential. Comparison of the three electrical exploration techniques indicates that: the bipole-dipole resistivity mapping method is the least useful; the dipole-dipole resistivity method can be very useful, but is, for practical purposes, exceptionally expensive and difficult to interpret; the E-field ratio telluric method can be a highly successful reconnaissance technique for delineating structures and relating the resistivities of different regions within the survey area.

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This paper is a two-dimensional numerical model study and comparison of the polar dipole-dipole and Schlumberger resistivity arrays. A catalog of dipole-dipole and Schlumberger apparent resistivity pseudo-sections is presented. It is concluded that: for the Schlumberger array, data can be accurately interpreted only if the resistivity structure is horizontally layered, and conductive bodies having a depth of burial greater than their width are not observed; for the dipole-dipole array, complex anomaly patterns unrelated in appearance to the causative structure result from simple models, hence, a familiarity with model results is essential to interpretation of these data.

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