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On Cratering: A Brief History, Analysis, and Theory of Cratering

Description: Cratering is a subject that has been studied by many investigators for many years for many purposes. These purposes range from experimental studies of physical properties to large scale excavations using explosive charges of kiloton size. In the past ten years considerable effort has been devoted to cratering experiments for the purposes of determining the effects of cratering by nuclear explosions, with recent accent on Plowshare applications. From the large amount of data available for craters in alluvian has been possible to establish very reliable relationships between charge size, depth of bursty crater radii, and crater depths. In addition it has been possible to construct a preliminary theory of the mechanics of explosive crater formation. The available experimental data for nuclear and high explosive craters are reviewed, with particular emphasis on the data for desert alluvium, and the pertinent relationships are derived. A theory of the important cratering mechanisms, which has been evolved on the basis of these data and data from other sources, is outlined. (auth)
Date: August 22, 1961
Creator: Nordyke, M. D.
Partner: UNT Libraries Government Documents Department
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Oscillating Vertical Magnetic Dipole Above a Conducting Half-Space

Description: The electromagnetic field produced by a vertical oscillating magnetic dipole above a plane conducting earth is obtained in integral form. An exact solution in closed form is obtained for the case in which the dipole and the point of observation are both located on the surface of the earth. (auth)
Date: April 1, 1961
Creator: Wesley, J. P.
Partner: UNT Libraries Government Documents Department
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Emission Characteristics of Tantalum, Tungsten, Rhenium, and Iridium in Plasma Diodes

Description: Experimental determinations of the ionic and electronic emission characteristics of Ta, W, Re, and lr cathodes in vapor thermionic converters are compared. It is shown that Ta provides superior thermal ionization qualities at high pressure compared with W, Re, and Lr. High electronic current densities may be obtained from Cs on Re and Cs on Ir at much lower Cs vapor pressures than from Ta or W. An over-all efficiency of 19% was achieved with a Re cathode at 2440 deg K. (auth)
Date: March 15, 1962
Creator: Gust, W. H.
Partner: UNT Libraries Government Documents Department
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Annotated Bibliography of Theories of the Equation of State of Ionized Gases and Strong Electrolyte Solutions

Description: This bibliography lists 297 references on the equation of state of ionized gases and electrolyte solutions, including calculations of closely related quantities such as free energy, partition functions, o smotic pre ssure, activity coefficients, and equilibrium compositions of partially ionized systems. A subject index and a supplementary list of 42 bibliographies on plasma physics and similar topics are included. (auth)
Date: August 1, 1961
Creator: Brush, S. G. & Wensrich, C. J.
Partner: UNT Libraries Government Documents Department
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Noise Considerations in Nuclear Pulse Amplifiers

Description: The effects of certain pulse-shaping networks on the signal-to-noise ratio of a nuclear pulse amplifier were considered. The shaping networks discussed are: equal RC-integrating and RC-differentiating time constant, single- delay-line clipper and RC integrator, and doubledelay-line clipper and RC integrator. The effects of these networks on the signal, when high count rates and overload pulses are present, were also considered. Equations and curves were developed for the energy resolution (signal-tonoise ratio) and resolving time (related to the ability to operate at high counting rates) of the networks. Experimental results are shown for the energy resolution of the types of pulse- shaping networks considered. (auth)
Date: December 20, 1961
Creator: Landis, D. A.
Partner: UNT Libraries Government Documents Department
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Remote Plastic Bag Passout Unit for High-Level Radiochemical Operations

Description: A system is designed for making remote sealed-bag passouts from a multicurie-level chemistry processing enclosure. The polyethylene bags are changed remotely without exposing contaminated surfaces while always maintaining a low leak rate seal. The system employs an interchange box (passout box) attached to the chemistry enclosure. Integrated with the box is a hydraulically operated jack that raises and lowers the bags, and a welder-cutter for sealing them. A single master-slave manipulator teamed with the above units handles all operations. (auth)
Date: August 1, 1961
Creator: Fleischer, E. S.; Parsons, T. C. & Howe, P. W.
Partner: UNT Libraries Government Documents Department
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Effect of Solute Atoms Upon Vacancy Climb of Prismatic Dislocations in Al- 5% Mg Alloy

Description: The climb rate of prismatic dislocations in quenched Al-5% Mg Alloy was studied by bulk annealing and also by high-temperature electron microscopy of thin foils, In bulk and thin-foil specimens, loops and helices were always observed to grow. The activation energy was determined to be 0,95 plus or minus 0.05 ev. The results can be interpreted on the basis of a binding energy between vacancies and magnesium atoms which can be x0.1 to 0.4 ev, depending on their geometrical configuration. (auth)
Date: September 1, 1962
Creator: Eikum, A. & Thomas, G.
Partner: UNT Libraries Government Documents Department
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Ejection of Large Fragments in High-Energy Nuclear Reactions

Description: Several features of the production of Na/sup 24/ and Mg/sup 28/ fragments produced in the interaction of protons and He ions with Cu, Ag, Au, and U were investigated. Formation cross sections were determined for He ions of different energies between 320 and 880 Mev and for protons of 700 Mev. Thick- target recoil experiments were performed at bombarding energies of 0.7 and 3 Bev for protons, and 880 Mev for He ions. Also given are some recoil measurements of Na/sup 24/ from Al. Analysis of data obtained with target materials heavier than Al showed that for the bombarding energies used, Na/sup 24/ and Mg/sup 28/ are probably produced by the cleavage of the target nucleus into two heavy fragmerts. One of these fragments has a mass approximately equal to the mass Na 4 or Mg/6 and the other contains most of the remaining mass of the target nucleus. However, Na/sup 24/ and Mg/sup 28/ are very probably not slowly evaporated particles nor products of a slow fission process. The experimental information covering fragmentation from photographic emulsion studies and radiochemical studies is discussed. The various mechanisms proposed are considered and a new one suggested. According to this new mechanism Na/sup 24/ Mg/sup 28/ and the more energetic fragments observed in nuclear emulsions are ejected promptiy from the parent nucleus by very complex nucleon-nucleon cascades and by collective effects. (auth)
Date: September 1, 1961
Creator: Crespo, V. P.
Partner: UNT Libraries Government Documents Department
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Preliminary Results of High-Temperature Bare U$sup 235$-C Critical Assembly Measurements

Description: The influence of temperature on the critical buckling or bare graphite assemblies with various carbon-to-uranium235 molar ratios has been measured. A range from l185: 1 to 2l,690: 1 was covered, for 45 to 1205'F. Preliminary results indicate that the fractional rate of change of critical buckling with core temperature varies monotonically with C/U2as ratio by a factor of five over the factor-of-eighteen range in gross C/U2as ratio. This quantity appears to approach asymptotically a value near 2%/l00"F at very high C/U2ss ratios. (auth)
Date: June 1, 1961
Creator: Finke, R. G.
Partner: UNT Libraries Government Documents Department
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Force Multiplier for Use With Master Slaves

Description: A force multiplier was designed. This piece of equipment was made to increase the gripping force presently available in the Model 8 master slave. The force multiplier described incorporates a clamp which can be quickly attached to and detached from the master slave hand. (auth)
Date: June 1, 1961
Creator: Miles, L. E.; Parsons, T. C. & Howe, P. W.
Partner: UNT Libraries Government Documents Department
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Kinetic Studies of the Reactions Occurring Between Tungsten and Gases at Low Pressure and High Temperatures

Description: Oxygen, nitrogen, and nitric oxide gases were passed through a system consisting of a tungsten filament, an ion gauge, and a mass spectrometer. The ion gauge recorded total pressures and the spectrometer recorded partlal pressures of O/sub 2/, N/sub 2/, NO, CO, COa, and H/sub 2/O. From the way these pressures changed with filamert temperature, the rates of conversion of O/sub 2/ to volatile tungsten oxides and O, and of NO to volatile tungsten oxides N/sub 2/ , O/sub 2/, and O were computed. The time rate of resistance change in the filament was used to compute the rate of conversion of tungsten to tungsten oxides. The filament temperatures ranged from 1950 through 2600 deg K and gas pressures ranged from 10/sup -8/ to 10/sup -6/ atm. For the tungsten-oxygen reaction, the rates of tungsten and oxygen loss were found to depend upon oxygen atom concentration on the surface. The rate of oxide power, depending upon the concentration of oxygen atoms on the surface. The reaction rate at constant oxygen pressure decreases with increasing temperature. For calculational purposes, the tungsten oxygen gas moleeules were assumed to be WO/sub 3/ only, though WO/sub 2/ and WO are other possible products. The apparent activation energy for the formation of WO/sub 3/ decreases from 14to -20 kcal./mole as the concentratlon of oxygen atoms decreases, because of the competing processes of oxygen molecule desorption from the surface. The rate of reaction of nitrogen with tungsten was found to be less than could be measured under the conditions of this study. The rate of decomposition of nitric oxide was found to depend upon the number of adsorption sites available on the surface, and the rate is controlled by the adsorption of a molecule on a site. The over-all rate decreased with increasing pressure and had …
Date: April 1, 1962
Creator: Anderson, H. U.
Partner: UNT Libraries Government Documents Department
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Synthesis of Wave-Forming Networks

Description: Passive networks whose specified wave forms are given as a function of time are discussed. The wave forms may be periodic or a single pulse. Suggestions and techniques are presented which should enable a circuit designer with a basic knowledge of network synthesis procedures to obtain wave-forming networks for a wide variety of cases. (auth)
Date: August 1, 1961
Creator: LaPatra, J. W.
Partner: UNT Libraries Government Documents Department
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