UNT Libraries Government Documents Department - 31 Matching Results

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Communication: From Molecules to Mars

Description: An analysis is made of the energetic, molecular, macromolecular and organizational steps which appear to be essential for the development of a living cell from a nonliving origin. Accepting the current view of the primitive atmosphere of the earth, experimental demonstration for the formation of the fundamental molecules of living organisms (amino acids, fatty acids, purines and pyrimidines) under the influence of available energy sources (ultraviolet light, ionizing radiation and electric disc… more
Date: August 1, 1962
Creator: Calvin, Melvin
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Development and Evaluation of Large Volume Scintillation Detectors and Their Application to Radioisotope Process Control

Description: Large-volume scintillation detectors are being developed for radioisotope control of unit processes. In the development work, mirror-finished aluminum foil reflectors were better than diffuse reflectors, argon flushing to remove dissolved oxygen from liquid scintillators improves the pulse amplitude, and liquid scintillators are superior to plastics. Dimethyl POPOP was found to be an excellent primary solute; optimum concentration is 2.5 g/l in toluene with argon flushing and no secondary solut… more
Date: January 1, 1962
Creator: Perry, J. K.
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The Effect of Ionizing Radiation on the Optical and Electrical Properties of the Alkali Halides

Description: Various mechanisms for the formation of point defects in ionic crystals are considered. Their probable importance as a function of the energy of the ionizing radiation and the temperature at which the irradiation takes place is discussed. Complex centers formed from aggregates of simple point defects are reviewed and their occurrence considered in terms of the expected spatial distribution of the point defects. The effect of high energy x rays and protons on the ionic conductivity is discussed … more
Date: January 1, 1962
Creator: Royce, B S.H.
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Electrical and Magnetic Properties of Holmium Single Crystals

Description: Magnetic moment measurements are made on holmium single crystals (hcp) from 1.3 to 300 deg K in magnetic fields from 250 to 18,000 Oe, with the field applied along the c axis, the a axis, and a (1010) direction. The STA1010! direction is the direction of easy magnetization with an extrapolated effective moment per atom at saturation of 10.34 Bohr magnetons. Basal plane measurements show antiferromagnetism below the Neel temperature of 132 deg K with basal plane anisotropy occurring below 80 deg… more
Date: September 15, 1962
Creator: Strandburg, D. L.; Legvold, S. & Spedding, F. H.
open access

EPSILON HYPERONS IN THE REACTION K- + P -->+ K+

Description: No Description Available.
Date: June 5, 1962
Creator: Alvarez, Luis W.; Berge, J. Peter; Kalbfleisch, George R.; Button-Shafer, Janice; Solmitz, Frank T.; Stevenson, M. Lynn et al.
open access

FACTORS IN RADIOGRAPHY AT ENERGIES BELOW 400 kvp

Description: From 1963 American Society of Metals/Metals and Materials Show, Cleveland, Oct. 1963. 23rd National Convention of the Society for Nondestructive Testing. The factors which affect the attainment of optimum results in radiography are radiation source, specimen, filmscreen combination, film processing, and their mutual relationships. A general review is presented of radiographic practice and the effects of variations in the factors, at energies below 400 kvp, on radiographic contrast and sensitivi… more
Date: January 1, 1962
Creator: McClung, R W
open access

HELIUM THREE

Description: A review is given of the present state of knowledge concerning the condensed phases of He{sup 3}. Attention is confined to the pure substance, and emphasis is placed upon the theoretical understanding of the material.
Date: September 11, 1962
Creator: Sessler, Andrew M.
open access

A High-Speed Readout for Multi-Channel Pulse-Height Analyzers

Description: From American Nuclear Society Meeting, New York, Nov. 1963. In computer-coupled automated activation analysis such as in the Mark II system, conventional methods of data readout impose a serious restriction on the minimum handling time per sample. A data coupler for operating between the data accumulation system and the computer tape unit was developed which contributes nothing to the handling time per sample, does not distort the data, and prepares the data for direct computer entry. In additi… more
Date: January 1, 1962
Creator: Wilkins, W. W.; Fite, L. E. & Wainerdi, R. E.
open access

THE IMPURITY OF SCIENCE

Description: Science is impure in two ways. There is not a 'pure' science. By this I mean that physics impinges on astronomy, on the one hand, and chemistry on biology on the other. And not only does each support its neighbors but derives sustenance from them. The same can be said of chemistry. Biology is, perhaps, the example par excellence today of an 'impure' science. Beyond this, there is no 'pure' science itself divorced from human values. The importance of science to the humanities and the humanities … more
Date: April 19, 1962
Creator: Calvin, Melvin
open access

Intermediate Phases in Binary Systems of Technetium-99 With Several Transition Elements

Description: An exploratory survey was made of the intermediate phases formed when Tc/ sup 99/ is alloyed with the Sc, Ti, V, Cr, Mn, and Fe-group elements. A total of nineteen intermediate phases were identified and found to be isomorphous with the Cr/sub 3/O-type, CsCl-type, MgZn/sub 2/-type, gamma -phase, or sigma -phase structure. The alloying characteristics of Tc are rationalized in terms of periodic table relationships. (auth)
Date: December 1, 1962
Creator: Darby, J. B., Jr.; Lam, D. J.; Norton, L. J. & Downey, J. W.
open access

Laboratory-Scale Demonstration of the Fused Salt Volatility Process

Description: The feasibility of processing enriched irradiated zirconium--uranium alloy fuel by the fused salt-fluoride volatility procedure has been demonstrated in laboratory tests with fuel having a burnup of over 10%. Uranium recoveries were greater than 99% and decontamination factors for radioactive fission products were 10/sup 6/ to 10/sup 6/. The UF/sub 6/ product contained significant quantities of nonradioactive impurities; additional work in this area is needed. (auth)
Date: August 1, 1962
Creator: Cathers, G. I.; Jolley, R. L. & Moncrief, E. C.
open access

NEUTRON RADIOGRAPHY: A 1962 PROGRESS REPORT

Description: The possibility of improved detection discrimination between selected materials; the high absorption of several 1ight materials such as hydrogen, lithium, and boron; and the relatively low absorption of many heavy materials are some characteristics which make neutron radiographic inspection attractive as a complementary technique to xradiography. A study of neutron radiography is reported in which the emphasis has been placed upon determining many of the characteristics of various techniques fo… more
Date: August 17, 1962
Creator: Berger, Harold
open access

New Hot Laboratory Facilities at Los Alamos

Description: New Hot Laboratory Facilities which support three major research programs directed by the Los Alamos Scientific Laboratory of the University of California are described. For the Nuclear Rocket Propulsion Program, a hot cell addition to the Radio Chemistry Building at Los Alamos will be completed early in 1963, and construction is expected to start soon on the hot cell addition to the Maintenance, Assembly and Disassembly Building at the Nuclear Rocket Development Station in Nevada. Integral hot… more
Date: January 1, 1962
Creator: Wherritt, Charles R.; Franke, Paul R.; Field, R. E. & Lyle, A. R.
open access

PERTURBATION THEORY OF MANY-BOSON SYSTEMS

Description: A noncanonical transformation of the boson creation and annihilation operators is performed in order to obtain a Hamiltonian which can be treated by the standard methods of field-theoretic perturbation theory. The standard results of Belyaev (with a slight modification) are rederived by this technique. (auth)
Date: December 15, 1962
Creator: Kromminga, A.J. & Bolsterli, M.
open access

PERTURBATION-THEORY RULES FOR COMPUTING THE SELF-ENERGY OPERATOR IN QUANTUM STATISTICAL MECHANICS

Description: Highly convenient rules are given for the general term in the time-independent perturbation-theory expansion for the self-energy operator of quantum statistical mechanics. The rules are derived by starting from the usual formalism involving time-dependent Green's functions. The well-known formulas for thermodynamic quantities in terms of the self-energy operator are included for completeness.
Date: December 17, 1962
Creator: Baym, Gordon & Sessler, Andrew M.
open access

A PULSED EDDY CURRENT TEST SYSTEM USING REFLECTED FIELDS

Description: An eddy current test system is described in which the test information is detected as a series of fields reflected from the metal surface and interior. Pulsed electromagnetic fields are caused to impinge upon the test specimen. These fields are restricted to a small cross sectional area over a path in space long enough to be useful for test purposes by devices called mask-apenture assemblies. This approach provides a number of advantages over conventional eddy current methods of comparable capa… more
Date: June 11, 1962
Creator: Renken, C. J.
open access

REACTIVE COLLISIONS IN CROSSED MOLECULAR BEAMS

Description: The distribution of velocity vectors of reaction products is discussed with emphasis on the restrictions imposed by the conservation laws. The recoil velocity that carries the products away from the center of mass shows how the energy of reaction is divided between internal excitation and translation. Similarly, the angular distributions, as viewed from the center of mass, reflect the partitioning of the total angular momentum between angular momenta of individual molecules and orbital angular … more
Date: January 1, 1962
Creator: Herschbach, D.R.
open access

Recent Developments in Multichannel Pulse-Height Analysis

Description: The state of the pulse-height analyzing art is reviewed with particular emphasis on the developments of the past two years. The discussion includes consideration of multidimensional instruments, calibration-stabilizing techniques, and some of the auxiliary features that are becoming increasingly available on commercial instruments. Possible future developments with respect to resolving time and memory organization is discussed briefly. (auth)
Date: June 1, 1962
Creator: Chase, R.L.
open access

SCATTERING OF A VELOCITY SELECTED POTASSIUM BEAM BY NEON, ARGON, AND XENON GASES AT DIFFERENT TEMPERATURES

Description: A thermal K beam was velocity selected, and scattered by Ne, Ar, and Xe gases. The dependence of the total cross section on relative velocity is approximately v/sup -0.4/ for K--Ar and K--Xe, and v/sup 0.8/ for K--Ne. The average relative velocity ranges were 400 to 1430 m/sec for Ne, 480 to 1350 m/sec for Ar, and 380 to 1320 m/sec for Xe. The dependence of the cross section on relative velocity was obtained by removing the cross section from the collision frequency integral. For the v/sup -0.4… more
Date: January 1, 1962
Creator: Brown, Jr, H H; Lulla, K & Bederson, B
open access

Secondary Isotope Effects in Molecular Structure

Description: A study was made to determine whether secondary iso tope effects also occur in molecular structure. Electron diffraction studies were carried out on ethane and deuteroethane. In C/sub 2/H/sub 6/ the mean C-C and C-H bond lengths found agreed very closely with values determined for other paraffin hydrocarbons, and the C--H bond showed a normal primary isotope effect (~ 0.005 A) similar to that found in methane when H is replaced by O. The output of the leastsquares analysis suggested that the me… more
Date: June 15, 1962
Creator: Bartell, L. S.
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