91 Matching Results

Search Results

MAGNESIUM TURNOVER IN MAN

Description: Data are reviewed from a number of studies on the metabolism of Mg in man and the role of Mg in biological processes. Results are reported from studies using Mg/sup 28/ as a tracer of Mg metabolism in laboratory animals and in man in health and various disease states. It is postulated that the role of Mg in many vital processes may be explained by the fact that the Mg ion tends to form hydrates and double salts and hence has the capacity for complex formation. (C.H.)
Date: January 1, 1963
Creator: Aikawa, J K
Partner: UNT Libraries Government Documents Department

An Isochronal Differential Microcalorimeter

Description: An isochronal differential-type microcalorimeter has been designed and constructed. As a result of its simple design it is very easy to handle the samples and assemble the calorimeter. Important to the operation of the calorimeter is a program, also working on the differential principle, that provides linear temperature rise of the samples. The calorimeter is used to measure very small energy releases such as those found in precipithtion, stored energy, etc. It is demonstrated that the calorimeter is easily capable of measuring 0.005 cal with a probable error of the order of 1 to 2%. (auth)
Date: August 1, 1963
Creator: Arndt, R.A. & Fujita, F.E.
Partner: UNT Libraries Government Documents Department

Atomic Binding Energies From a Modified Thomas-Fermi-Dirac Theory

Description: A quantum correction of the statistical model of the atom was obtained by modifying March and Plaskett's region of integration in the (n/sub r/,l), or quantum-number, plane. Integrations over the plane lead, in the unmodified case, to the Thomas-Fermi density expression and energy equation. Integrations over the modified region are here shown to produce a modified Thomas-Fermi expression for the electron density, and a correction to the kinetic energy. The latter correction shows a similarity to the Weizsacker correction, but is smaller by a slowly changing factor of the order of 10. A modified Thomas-Fermi-Dirac equation was derived by the standard variational procedure. Numerical solutions of the equation were obtained, yielding atomic binding energies in much better agreement with experimental values than those of the unmodified theory. (auth)
Date: October 1, 1963
Creator: Barnes, J.F. & Cowan, R.D.
Partner: UNT Libraries Government Documents Department

NEUTRON EXPERIMENTS WITH A TANDEM ACCELERATOR

Description: l963. The Wisconsin tandem accelerator is used part of the time for experiments in neutron physics. In these experiments the properties of neutrons from charged-particle reactions as well as the interaction of neutrons with nuclei are studied. Some of the techniques used and some of the results obtained are described. (auth)
Date: January 1, 1963
Creator: Barschall, H H
Partner: UNT Libraries Government Documents Department

Neutron Radiographic Inspection of Heavy Metals and Hydrogenous Materials

Description: The possibility of using thermal-neutron radiography for inspecting heavy metals and hydrogenous materials was examined. The data include exposure curves, contrast sensitivities, and an assessment of the influence of higher energy neutrons and interfering gamma radiation on image quality. It is shown that, in the case of homogeneous materials, neutron radiography presents definite advantages for the inspection of heavier metals such as uranium, bismuth, and lead, and that the images obtained in such inspections are influenced very little by other radiation in the thermal-neutron beam. This is somewhat less true for intermediate metals such as steel and tungsten, although in these cases too, some exposure time advantage can usually be gained. Nevertheless, neutron radiographic inspection of these intermediate materials may be limited to those cases in which some complication, such as radioactivity of the sample, is involved. Thermal-neutron inspection of hydrogenous materials having a thickness greater than about an inch is not recommended and may be useful primarily in special cases such as one in which the light material is in some combination with a heavier, x-ray absorbing material. (auth)
Date: March 11, 1963
Creator: Berger, H. & Kraska, I. R.
Partner: UNT Libraries Government Documents Department

EFFECT OF FLUORIDE IONS ON THE AQUEOUS CORROSION OF ZIRCONIUM ALLOYS

Description: A review was made of the effects of fluoride ions on the corrosion behavior of zirconium alloys in high-temperature water. Corrosion was found to occur as the result of contamination of the water or the zirconium surface. A major source of fluorides is undue delay in rinsing the HF--HNO/sub 3/ pickling solution during surface preparation. The oxide on corrosion-resistant material has been found to contain up to 7600 ppm fluoride from this source. The threshold concentration of fluoride in the oxide film which produces poor corrosion resistance ranges from 8500 to 17,000 ppm. Accelerated corrosion from fluorides in water at 300 to 360 deg C occurs at about 100 ppm, although increased corrosion has been reported at 10 ppm fluoride in water at 300 deg C. Fluorocarbon plastics degrade and contribute fluorides to the hightemperature water or to the alloy surface when in direct contact with zirconium. Chlorides (1 to 10,000 ppm) and iodides (1270 ppm) do not adversely affect the corrosion behavior of zirconium alloys in water at 360 deg C. The mechanism of corrosion is not well understood but apparently is related to the formation of insoluble zirconium oxyfluorides during pickling and during exposure to fluoride- contaminated water. (auth)
Date: January 1, 1963
Creator: Berry, W E
Partner: UNT Libraries Government Documents Department

Radiobiological Basis for the Whole Body Radiation Syndrome

Description: Data are presented that show a marked species difference in the degree of damage and in the course of events seen in the bone marrow and peripheral blood after a given dose of radiation. The data taken together indicate strongly, but do not prove, that the picture seen results primarily from damage to the stem cell population. This damage to the stem cells is manifested later in the more mature differentiating cells of the marrow, and in the peripheral blood. The picture seen results both from death of stem cells, and also injury leading to reduced proliferative capacity, with later death of the injured stem cell and all of its progeny. Thus the picture seen is a result of both quantitative and qualitative changes resulting directly from the exposure of the stem cells, and species differences relative to sensitivity and time course of events appear to depend to a large degree on differential sensitivity of the bone marrow stem cell populations to death and injury. (auth)
Date: July 19, 1963
Creator: Bond, V.P. & Fliedner, T.M.
Partner: UNT Libraries Government Documents Department

Wire Chamber-Computer System

Description: No Description Available.
Date: January 1, 1963
Creator: Bounin, J.; Miller, R.; Neumann, M.; Sarma, J. & Sherrard, H.
Partner: UNT Libraries Government Documents Department

AN INFORMATION STORAGE AND RETRIEVAL SYSTEM FOR IRRADIATION EFFECTS IN METALS

Description: An information storage and retrieval system (PIC) was developed, utilizing the IBM 7090 computer, for handling data pertaining to the effects of neutron irradiation on metals. The input includes a reference identification, an appropriate abstract or extract summarizing the article, code identification parameters analogous to those used by the ASM-SLA Literature Classification System, and special codes identifying relevant irradiation and testing parameters. The output contains the same data plus printing out the meaning of all special codes. Presently, the information storage consists of more than two hundred references representing several thousand lines of information. The system is both general and definitive, permitting the selection of a single piece of information or of many references dealing with a general field. It is possible to select material on the basis of one or more of the following factors: material, general or specific; type of literature; general or specific property such as mechanical tests or tensile tests; conditions of irradiation including type and level of flux, integrated flux, irradiation temperature, and reactor environment; test conditions such as temperature and environment; and general variables that might be controlling such as strain rate, specimen geometry, grain size, and fabrication history. It is felt that this system and the data systems will permit the rapid selection of relevant references once an optimum number of such references are available. (P.C.H.)
Date: August 15, 1963
Creator: Bush, S. H.
Partner: UNT Libraries Government Documents Department

ATOM TO ADAM

Description: No Description Available.
Date: November 1, 1963
Creator: Calvin, Melvin & Calvin, G.J.
Partner: UNT Libraries Government Documents Department

Cryogenic targets for electron scattering

Description: Over the past few years we have developed a system which allows several different liquid hydrogen and liquid deuterium targets to be placed in the electron beam of the Stanford Mark III accelerator and which can be operated from a remote position. The geometry of our scattering chamber requires that the motion (of the various targets into position) must be in the vertical direction, but that the overall height of the system be constant. These requirements are met by using an internal retractable bellows arrangement to raise and lower the target cells. As many as five cells can be used in conjunction with a single reservoir system.
Date: June 1, 1963
Creator: Chambers, B.; Hofstadter, R.; Marcum, A. & Yearian, M. R.
Partner: UNT Libraries Government Documents Department

THE ELECTRON THEORY OF SIMPLE METALS AND ALLOYS

Description: The successes and difficulties of the Bloch model of a metal are briefly reviewed, and the Landau quasi-particle theory amd the pseudopotential theory are briefly discussed. These two notions are made the basis for a revised version of the Bloch model that avoids the conceptual difficulties of the original model, while retaining and explaining its appealing features. Well known empirical generalizations concerning the relative importance of conduction-electron density, composition, and structure for the electronic properties are presented, and their implications are reexamined. A theory of the form required by the empirical generalizations is developed. Recent approximate calculations are discussed, and a variety of conclusions are drawn from these relating to the possibility of explanation of the empirical generalizations by the theory. 42 references. (auth)
Date: January 1, 1963
Creator: Cohen, M H
Partner: UNT Libraries Government Documents Department

Calcium Turnover Studies in Man

Description: Methods for determination of calcium turnover in man with radioisotopes are presented and the clinical use of various techniques is evaluated. In the discussion of kinetic analyses, some important observations were made. The accretion rate calculation can be made independent of the number of compartments in the exchangeable calcium pool, and thus is not distorted by approximate estimations of this pool. However, if the exchangeable calcium pool is calculated with the isotope dilution technique, and the accretion rate obtained from this value by the total turnover equation, then an error is introduced into the value of the accretion rate. It was also pointed out that the multicompartment treatment is more appropriate than the customary single compartment analysis and utilizes all available information. Since the pool size has been of little clinical use so far, it was suggested that multicompantment analyses be used in the future. At present, no accepted model exists which can account for all data obtained in tracer studies and in particular for the last part of the serum disappearance curve. Preliminary results of long term studies of the retention in bones of strontium-85 was presented. These show that there is measurable turnover of tracer deposited in bone even several months after injection. (auth)
Date: January 1, 1963
Creator: Corey, K. R.; Weber, D.; Merlino, M.; Greebberg, D.; Kenny, P. & Laughlin, J. S.
Partner: UNT Libraries Government Documents Department

PROPERTIES OF RADIOACTIVE Re$sup 18$$sup 9$

Description: The isotope Re/sup 189/ was produced by fsst neutron irradiation of osmium and by the ( alpha ,p) reaction on tungsten. The rhenium was separated chemically from the target material, and beta, gamma, and internal conversion spectra were measured. The mass assignment is confirmed by the observation of eleven electromagnetic transitions in the Os/sup 189/ daughter, including the 30.8-kev isomeric transition (8 hr), all of which were known from the decay of Ir/ sup 189/. Re/sup 189/ has a half-life of 23.4 plus or minus 1.0 hr and emits betaray groups with end-point energies 1000, 780, and 725 kev, and probably others. Results of coincidence measurements lead to some new information about the level scheme of Os/sup 189/ Evidence was found for strong rotation-particle coupling between low-lying K =1/2 and K = 3/2 bands in Os/sup 189/. 40 references. (auth)
Date: March 29, 1963
Creator: Crasemann, B.; Emery, G. T.; Kane, W. R. & Perlman, M. L.
Partner: UNT Libraries Government Documents Department

LYMPHOCYTE PRODUCTION MEASURED BY EXTRACORPOREAL IRRADIATION, CANNULATION AND LABELING TECHNIQUES

Description: The labeling of newly-formed lymph cells with tritiated thymidine, lymphatic duct cannulation, and the peripheral destruction of lymphocytes by extracorporeal irradiation of the blood were used to estimate the mass of prestored lymphocytes and the relative degree of recirculation of 1ymphocytes from blood to lymph and back again. Topics discussed include the effects of extiacorporeal irradiation on the histologic picture of the lymphoreticular tissue, the influence of extracorporeal irradiation upon the thoracic duct output, and preliminary observations on labeling of lymphocytes by tritiated thymidine at the completion of extracorporeal irradiation. Data indicate that the mass of preformed small lymphocytes may be as large as 40 times that present in peripheral blood, that the blood feeds lymphocytes primarily into the lymph, and presents strong evidence for lymphocyte recycling. (C.H.)
Date: January 1, 1963
Creator: Cronkite, E.P.; Jansen, C.R.; Cottier, H.; Rai, K. & Sipe, C.R.
Partner: UNT Libraries Government Documents Department

Superconductivity and future accelerators

Description: For 50 years particle accelerators employing accelerating cavities and deflecting magnets have been developed at a prodigious rate. New accelerator concepts and hardware ensembles have yielded great improvements in performance and GeV/$. The great idea for collective acceleration resulting from intense auxiliary charged-particle beams or laser light may or may not be just around the corner. In its absence, superconductivity (SC) applied both to rf cavities and to magnets opened up the potential for very large accelerators without excessive energy consumption and with other economies, even with the cw operation desirable for colliding beams. HEP has aggressively pioneered this new technology: the Fermilab single ring 1 TeV accelerator - 2 TeV collider is near the testing stage. Brookhaven National Laboratory's high luminosity pp 2 ring 800 GeV CBA collider is well into construction. Other types of superconducting projects are in the planning stage with much background R and D accomplished. The next generation of hadron colliders under discussion involves perhaps a 20 TeV ring (or rings) with 40 TeV CM energy. This is a very large machine: even if the highest practical field B approx. 10T is used, the radius is 10x that of the Fermilab accelerator. An extreme effort to get maximum GeV/$ may be crucial even for serious consideration of funding.
Date: January 1, 1963
Creator: Danby, G.T. & Jackson, J.W.
Partner: UNT Libraries Government Documents Department

Adsorption of Activated Nitrogen

Description: No Description Available.
Date: August 3, 1963
Creator: Donaldson, E E; Winters, H F & Horne, D E
Partner: UNT Libraries Government Documents Department

MEAN SQUARE VOLTAGE FLUCTUATION MEASUREMENTS WITH NEUTRON-SENSITIVE ION CHAMBERS

Description: The mean square fluctuation voltage in neutron sensitiv ion chambers was measured rather than the d-c current to improve gamma discrimination and eliminate d-c cable leakage interference currents. The circuitry and chambe are described, and performance in the mean square volta mode is compared with that in the d-c current mode. (D.C.W.)
Date: November 1, 1963
Creator: DuBridge, R A
Partner: UNT Libraries Government Documents Department