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Fundamental theory of elastic wave scattering by defects in elastic materials: integral equation methods for application to ultrasonic flaw detection (open access)

Fundamental theory of elastic wave scattering by defects in elastic materials: integral equation methods for application to ultrasonic flaw detection

The use of ultrasonic methods in nondestructive testing depends on the interpretation of the scattering of sound waves by flaws. The theory of elastic waves and their scattering in non-uniform media is developed in detail from first principles, and in generality. Both integral equation and differential methods are discussed, with emphasis on the former. General methods for defining scattering cross sections are presented, and conservation theorems are noted. The Born Approximation to the integral equation is presented, and computed results for several experimental situations are discussed. Several corrections to papers in the literature are made, and in particular the exact scattering of a transverse wave by a spherical flaw is compared with the Rayleigh (long wave) limit.
Date: May 1, 1976
Creator: Gubernatis, J.E.; Domany, E.; Krumhansl, J.A. & Huberman, M.
System: The UNT Digital Library
Development of a prototype high temperature amplifier for geothermal well logging. Final report (open access)

Development of a prototype high temperature amplifier for geothermal well logging. Final report

A high temperature amplifier for use in geothermal well logging was developed. This development was based on the use of ceramic vacuum tubes as the active circuit element, since these tubes have the capability to operate in the high ambient temperature environment. The primary goal of this program was to design, build, and deliver a prototype amplifier capable of continuous operation in a 250/sup 0/C environment. A development program designed to meet this goal covered four phases. These phases were (1) development of the basic circuit configuration with conventional, low cost glass envelope vacuum tubes; (2) modification of the circuitry to accommodate the ceramic vacuum tubes; (3) a 1000-hour duration temperature cycle (48 hours at 260/sup 0/C and 2 hours at 20/sup 0/C); and (4) development of a prototype, deliverable amplifier. The following sections discuss the high temperature amplifier development program. Section 2 describes the amplifier performance, including design requirements, circuit design, development program, and the prototype amplifier. Section 3 presents test results from two breadboard models, one with conventional glass tubes and one with ceramic tubes, and the prototype amplifier. Section 4 describes the operation of the prototype amplifier. Circuit equations used for analysis and tube characteristics are contained …
Date: May 1, 1976
Creator: Cannon, W.
System: The UNT Digital Library
Solar-receiver heat-flux capability and structural integrity. Final report (open access)

Solar-receiver heat-flux capability and structural integrity. Final report

An experimental program was conducted to determine the operating characteristics of full length (65 feet) single and multi-tube once-through steam generator test sections subjected to radiant heat flux levels commensurate with commercial solar tower receiver application. Absorbed heat flux levels ranging from 0.15 to 0.71 Btu/in./sup 2/-sec (0.25 to 1.16 MW/m/sup 2/) were achieved in a horizontal facility utilizing graphite radiant heater arrays. Steam exit temperatures ranged from 625 F (two-phase) to 1380 F at pressures of 1000 to 2300 psia. Wall temperature profiles and fluid pressure losses were obtained and compared with an existing computer model.
Date: May 1, 1976
Creator: Tobin, R.D.
System: The UNT Digital Library
Effects of variations of selected repository design parameters for salt and granite host rocks (open access)

Effects of variations of selected repository design parameters for salt and granite host rocks

Perhaps the most important design consideration is the heat generated by the spent fuel assemblies or the high-level waste being placed in the repository. The sensitivity of repository design to this heat is reflected by the definition of temperature and thermochemical criteria. To assure environmental and occupational safety, limits may be placed on such parameters as spent fuel or waste temperature, canister temperature, rock temperature, strength-to-stress ratio of the excavated openings, surface uplift or subsidence, temperature increase in an aquifer, and temperature increase at or near the surface of the earth. Appropriate criteria are chosen to accomplish ready retrievability, to retard canister corrosion, to suppress the rate of nuclide leaching, to control the buoyant forces that drive potential nuclide migration, to assure mine safety, to assure formation stability, and to control the thermal and thermomechanical impact on the environment. Other major concerns in the location and design of a waste repository are the presence and effect of groundwater within the repository host rock and the surrounding strata. Additional groundwater considerations include its effect on canister integrity, its potential as a source of hydrogen, and its effect on the repository operational environment. Two types of retrieval are considered: operational verification and …
Date: May 1, 1976
Creator: unknown
System: The UNT Digital Library
U. S. working draft on repository physical descriptions in a granite formation. [LWR waste: spent fuel or reprocessing wastes] (open access)

U. S. working draft on repository physical descriptions in a granite formation. [LWR waste: spent fuel or reprocessing wastes]

This report presents a physical description of a reference deep-geologic repository located in a granite host rock at a depth of about 1500 meters. Two reference repository designs are described in this report. One is designed to accept wastes from a lightwater reactor (LWR) strategy in which no reprocessing occurs, and the spent fuel itself is considered a waste form. The second is designed to accept wastes from an LWR strategy with reprocessing in which uranium and plutonium are recycled.
Date: May 1, 1976
Creator: unknown
System: The UNT Digital Library
Deformation of liquid droplets and gas bubbles in electric fields. Research report No. 1 (open access)

Deformation of liquid droplets and gas bubbles in electric fields. Research report No. 1

The behavior of dielectric droplets and gas bubbles in electrostatic levitation, positioning, and control devices for laser-fusion target applications is studied. Because of the exacting tolerance requirements for the sphericity of laser fusion targets, there is concern over the electric field induced elongation effect which may exist in some or all of these schemes. These proposed tolerances suggest upper limits on the axis ratio ..gamma..: ..gamma.. - 1 < 10/sup -3/, which may severely limit the maximum allowable electric field in certain electrostatic levitation schemes. Calculations of the deformation of bubbles in cryogenic hydrogen were undertaken by Bliss, but only for large deformations up to ..gamma.. approximately 2. These calculations are extended down to very small deformations, that is: 10/sup -4/ < ..gamma.. - 1 < 10/sup -1/, for droplets of cryogenic liquid hydrogen (n - H/sub 2/) and bubbles in liquid hydrogen at its triple point. Also, the effect of pressure on the deformation has been explored. Further, approximate explicit analytic expressions for ..gamma..(E) have been obtained for the limit of small deformations.
Date: May 1, 1976
Creator: Jones, T. B. & McCarthy, M. J.
System: The UNT Digital Library
Stability of trapped-particle modes in lower-hybrid pump (open access)

Stability of trapped-particle modes in lower-hybrid pump

The stability of dissipative trapped-particle modes in the presence of a self-consistent lower-hybrid pump is analyzed theoretically. The pump can either be a single coherent wave or a spectrum of turbulent waves. Corresponding dispersion relations modified by the pump are derived and conditions for excitation and suppression of the modes are also discussed.
Date: May 1, 1976
Creator: Chen, L.; Kaw, P. K. & Tang, W. M.
System: The UNT Digital Library
Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan (open access)

Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan

The report is a synoptic review of data collected over the past twenty years on the chemistry of Lake Michigan. Changes in water quality and sediment chemistry, attributable to cultural and natural influences, are considered in relation to interacting processes and factors controlling the distribution and concentration of chemical substances within the Lake. Temperature, light, and mixing processes are among the important natural influences that affect nutrient cycling, dispersal of pollutants, and fate of materials entering the Lake. Characterization of inshore-offshore and longitudinal differences in chemical concentrations and sediment chemistry for the main body of the Lake is supplemented by discussion of specific areas such as Green Bay and Grand Traverse Bay. Residues, specific conductance, dissolved oxygen, major and trace nutrients, and contaminants are described in the following context: biological essentiality and/or toxicity, sources to the Lake, concentrations in the water column and sediments, chemical forms, seasonal variations and variation with depth. A summary of existing water quality standards, statutes, and criteria applicable to Lake Michigan is appended.
Date: May 1, 1976
Creator: Torrey, M S
System: The UNT Digital Library
Piezo electric polaron and polaron pinning in n-CdS (open access)

Piezo electric polaron and polaron pinning in n-CdS

The cyclotron resonance of the piezoelectric polaron in n-CdS has been investigated using far infrared spectroscopy at magnetic fields to 90 kOe. Both lamellar grating and Michelson Fourier transform spectrometers were used with a 0.3/sup 0/K Ge bolometer to study the photon energy region from 10 cm/sup -1/ to 60 cm/sup -1/. The theory of Miyake predicts that the frequency of the polaron's cyclotron resonance is shifted from the bare hand electron resonance frequency according to the expression: ..delta omega../sup p//sub c// ..cap omega../sub c/ varies as H/sup -1/ T/sup /sup 2///sup 3//. The magnetic field dependence of the present cyclotron resonance confirms this expression; the cyclotron mass isiezoelectric polaron effects. The bare band mass in n-CdS has also been determined by taking into account the Froehlich polaron interaction in addition to the piezoelectric polaron effects. For H parallel to the c-axis this cyclotron mass is 0.155 +- 0.005 m. The polaron pinning due to the 43 cm/sup -1/ optically inactive phonon has been observed.
Date: May 1, 1976
Creator: Nagasaka, K.
System: The UNT Digital Library
Correlation of radionuclide leachabilities with microstructures of glasses containing Savannah River Plant waste (open access)

Correlation of radionuclide leachabilities with microstructures of glasses containing Savannah River Plant waste

Leachabilities of cesium and strontium from the glass matrices were correlated with the microstructures of glasses containing waste sludge from two SRP waste tanks. All sludge components, except mercury which volatilized, were completely soluble in the melt, but small amounts of crystalline iron oxide precipitated during cooling. These precipitates were less leachable than the glass matrix. Even though the compositions of the two sludges that were tested were similar, glass containing one of the sludges devitrified during heating at 600/sup 0/C; glass containing the other sludge did not devitrify. Leachability of the devitrified glass was as much as 100 times greater than that of nondevitrified glass, but still very low, less than 10/sup -6/ g/(cm/sup 2/)(day).
Date: May 1, 1976
Creator: Kelley, J. A. & Rankin, W. N.
System: The UNT Digital Library
Alternatives for Managing Wastes From Reactors and Post-Fission Operations in the LWR Fuel Cycle: Volume 2. Alternatives for Waste Treatment (open access)

Alternatives for Managing Wastes From Reactors and Post-Fission Operations in the LWR Fuel Cycle: Volume 2. Alternatives for Waste Treatment

Volume II of the five-volume report is devoted to the description of alternatives for waste treatment. The discussion is presented under the following section titles: fuel reprocessing modifications; high-level liquid waste solidification; treatment and immobilization of chop-leach fuel bundle residues; treatment of noncombustible solid wastes; treatment of combustible wastes; treatment of non-high-level liquid wastes; recovery of transuranics from non-high-level wastes; immobilization of miscellaneous non-high-level wastes; volatile radioisotope recovery and off-gas treatment; immobilization of volatile radioisotopes; retired facilities (decontamination and decommissioning); and, modification and use of selected fuel reprocessing wastes. (JGB)
Date: May 1, 1976
Creator: unknown
System: The UNT Digital Library
Thorium utilization program progress report for January 1, 1974--June 30, 1975. [Reprocessing; refabrication; recycle fuel irradiations] (open access)

Thorium utilization program progress report for January 1, 1974--June 30, 1975. [Reprocessing; refabrication; recycle fuel irradiations]

Work was carried out on the following: HTGR reprocessing development and pilot plant, refabrication development and pilot plant, recycle fuel irradiations, engineering and economic studies, and conceptual design of a commercial recycle plant. (DLC)
Date: May 1, 1976
Creator: Lotts, A. L. & Kasten, P. R.
System: The UNT Digital Library
HEXEREI: a multi-channel heat conduction convection code for use in transient thermal hydraulic analysis of high-temperature, gas-cooled reactors. Interim report (open access)

HEXEREI: a multi-channel heat conduction convection code for use in transient thermal hydraulic analysis of high-temperature, gas-cooled reactors. Interim report

A description is given of the development and verification of a generalized coupled conduction-convection, multichannel heat transfer computer program to analyze specific safety questions involving high temperature gas-cooled reactors (HTGR). The HEXEREI code was designed to provide steady-state and transient heat transfer analysis of the HTGR active core using a basic hexagonal mesh and multichannel coolant flow. In addition, the core auxiliary cooling systems were included in the code to provide more complete analysis of the reactor system during accidents involving reactor trip and cooling down on the auxiliary systems. Included are brief descriptions of the components of the HEXEREI code and sample HEXEREI analyses compared with analytical solutions and other heat transfer codes.
Date: May 1, 1976
Creator: Giles, G. E.; DeVault, R. M.; Turner, W. D. & Becker, B. R.
System: The UNT Digital Library
Operational safety system reliability. Progress report, November 15, 1975--May 14, 1976. [LMFBR] (open access)

Operational safety system reliability. Progress report, November 15, 1975--May 14, 1976. [LMFBR]

The report describes the objectives and present status of a study concerning the operational reliability of nuclear power plants. The purpose of the study is to develop utilitarian models for use with the Liquid-Metal-Cooled Fast Breeder Reactor; initial testing of the formalism can be carried out with LWR operational data. Methods are being directed towards (1) day-to-day operation of the nuclear plant protection system and (2) to better understand the protection system sensor characteristics in order to anticipate off-normal conditions. The initial models now underway are based on moment-matching, confidence bounding, and convolution methods in the case of the protection system reliability, and for the sensor response function, a convolution of component reliability probability distributions and noise signatures.
Date: May 1, 1976
Creator: Hockenbury, R. W. & Yeater, M. L.
System: The UNT Digital Library
Density and shape factor of sodium aerosol. Progress report, January 1, 1976--March 31, 1976. [LMFBR type reactors] (open access)

Density and shape factor of sodium aerosol. Progress report, January 1, 1976--March 31, 1976. [LMFBR type reactors]

Several approaches for characterizing the physical and aerodynamic properties of irregularly shaped aerosol particles are reviewed. Measurements of density modification factor, dynamic shape factor, and particle density using an aerosol centrifuge and a scanning electron microscope are described. Calibration procedures for this characterization method are described and preliminary results reported.
Date: May 1, 1976
Creator: Hinds, W. & First, M. W.
System: The UNT Digital Library
Special problems in nuclear instrumentation. Progress report, September 1, 1975--August 31, 1976 (open access)

Special problems in nuclear instrumentation. Progress report, September 1, 1975--August 31, 1976

Five different mixtures of polypropylene, nylon-11, and carbon black were prepared and several specimens were molded of each. The object of this program is to determine the compatability of these components and their suitability for applications in radiation dosimetry. Significant advances were made in the fabrication of small ionization chambers. A new air-equivalent chamber was designed which incorporates essentially all of these advances. Seven cables which are in use for carrying the currents generated in ionization chambers have been studied with reference to this use.
Date: May 1, 1976
Creator: Spokas, J. J.
System: The UNT Digital Library
Mathematical model of a phantom developed for use in calculations of radiation dose to the body and major internal organs of a Japanese adult (open access)

Mathematical model of a phantom developed for use in calculations of radiation dose to the body and major internal organs of a Japanese adult

A mathematical model of a phantom simulating the body and major internal organs of a Japanese adult has been developed for use in computer calculations of radiation dose. The total body height of the mathematical phantom is 162 cm, and the total body mass is 55 kg based on densities of 0.3, 1.4, and 1.0 g/cm/sup 3/ for the lung, skeleton, and bulk tissues of the body, respectively.
Date: May 1, 1976
Creator: Kerr, G. D.; Hwang, J. M. & Jones, R. M.
System: The UNT Digital Library
Characteristics of American coals in relation to their conversion into clean energy fuels. Quarterly technical progress report, January--March 1976. [2 appendices; 19 refs. Dryflo separation tests data] (open access)

Characteristics of American coals in relation to their conversion into clean energy fuels. Quarterly technical progress report, January--March 1976. [2 appendices; 19 refs. Dryflo separation tests data]

Responses to the questionnaire, which was distributed to determine the extent to which the nation&#x27;s coal seams have been sampled and characterized, are being received. Early comparisons indicate a mathematical relationship between average random reflectance (Rapid Scan) and the mean-maximum reflectance as obtained by standard reflectance analysis. Results obtained so far show support of a diffusion dominance mechanism in the oxidation region of a combustion pot and a chemical kinetic mechanism in the gasification region. Values of reaction rates in coke beds have been calculated from experiments with a fixed bed shaft gasifier. Devolatilization of a North Dakota lignite in a laminar flow reactor and subsequent treatment of the resulting char has shown that weight loss is strongly dependent upon the isothermal decomposition time. Although gasification rates increase with increase in partial pressure of oxygen, the mechanism for gasification of a given char is independent of partial pressure of oxygen. Study of the reactivity of ion-exchanged lignite chars to steam shows that increased heat treatment decreases reactivity and ion exchange increases reactivity. Use of the DSC technique to study the thermal effects involved during chemisorption of oxygen on Saran carbon has yielded information on the activation energy (EA) of the …
Date: May 1, 1976
Creator: Spackman, W.; Davis, A.; Walker, P. L.; Lovell, H. L.; Essenhigh, R. H.; Vastola, F. J. et al.
System: The UNT Digital Library
Equation of state for the detonation products of hexanitrostilbene at various charge densities (open access)

Equation of state for the detonation products of hexanitrostilbene at various charge densities

An extensive description of the detonation behavior for the unique and useful high explosive hexanitrostilbene (HNS) is presented. To accomplish this the necessary experimental results measured by detonation of the pure material at charge densities of 1.00, 1.20, 1.40, 1.60, and 1.65 (g/cm/sup 3/ = Mg/m/sup 3/) were compiled and evaluated. Estimates of the equation of state of the detonation products were made for each charge density. To confirm these estimates two-dimensional hydrodynamic (HEMP code) calculations to simulate the cylinder test experiments for two charge densities of 1.2 and 1.6 Mg/m/sup 3/ were carried out. Detailed comparisons of the calculational and experimental results were made for these two tests. Interpolation and extrapolation of the equation of state parameters provided final estimates for the other charge densities. The results are summarized in five sets of Chapman-Jouguet parameters and JWL equation of state coefficients.
Date: May 1, 1976
Creator: Lee, E. L.; Walton, J. R. & Kramer, P. E.
System: The UNT Digital Library
Joining uranium to steel (open access)

Joining uranium to steel

A method has been devised which will allow the joining of uranium to steel by fusion welding through the use of an intermediate material. Uranium-0.5 titanium was joined to AISI 304L stainless steel by using a vanadium insert. Also, a method is now available for selecting possible filler metals when two entirely dissimilar metals need to be joined. This method allows a quantitative ranking to be made of the possible filler metals and thus the most likely candidate can be selected.
Date: May 1, 1976
Creator: Perkins, M. A.
System: The UNT Digital Library
Linear triangle finite element formulation for multigroup neutron transport analysis with anisotropic scattering (open access)

Linear triangle finite element formulation for multigroup neutron transport analysis with anisotropic scattering

The discrete ordinates method is the most powerful and generally used deterministic method to obtain approximate solutions of the Boltzmann transport equation. A finite element formulation, utilizing a canonical form of the transport equation, is here developed to obtain both integral and pointwise solutions to neutron transport problems. The formulation is based on the use of linear triangles. A general treatment of anisotropic scattering is included by employing discrete ordinates-like approximations. In addition, multigroup source outer iteration techniques are employed to perform group-dependent calculations. The ability of the formulation to reduce substantially ray effects and its ability to perform streaming calculations are demonstrated by analyzing a series of test problems. The anisotropic scattering and multigroup treatments used in the development of the formulation are verified by a number of one-dimensional comparisons. These comparisons also demonstrate the relative accuracy of the formulation in predicting integral parameters. The applicability of the formulation to nonorthogonal planar geometries is demonstrated by analyzing a hexagonal-type lattice. A small, high-leakage reactor model is analyzed to investigate the effects of varying both the spatial mesh and order of angular quadrature. This analysis reveals that these effects are more pronounced in the present formulation than in other conventional …
Date: May 1, 1976
Creator: Lillie, R. A. & Robinson, J. C.
System: The UNT Digital Library
Finite Deformation Analysis of Crack Tip Opening in Elastic-Plastic Materials and Implications for Fracture Initiation (open access)

Finite Deformation Analysis of Crack Tip Opening in Elastic-Plastic Materials and Implications for Fracture Initiation

Analyses of the stress and strain fields around smoothly blunting crack tips in both non-hardening and hardening elastic-plastic materials, under contained plane strain yielding and subject to mode I opening loads, have been carried out by a finite element method suitably formulated to admit large geometry changes. The results include the crack tip shape and near-tip deformation field, and the crack tip opening displacement has been related to a parameter of the applied load, the J-integral. The hydrostatic stresses near the crack tip are limited due to the lack of constraint on the blunted tip, limiting achievable stress levels except in a very small region around the crack tip in power law hardening materials. The J-integral is found to be path independent except very close to the crack tip in the region affected by the blunted tip. Models for fracture are discussed in the light of these results including one based on the growth of voids. The rate of void growth near the tip in hardening materials seems to be little different from the rate in non-hardening materials when measured in terms of crack tip opening displacement, which leads to a prediction of higher toughness in hardening materials. It is …
Date: May 1, 1976
Creator: McMeeking, R. M.
System: The UNT Digital Library
Analysis of evidence for an irreproducible martensite-like behavior in actinide metals and alloys below room temperature. [Review] (open access)

Analysis of evidence for an irreproducible martensite-like behavior in actinide metals and alloys below room temperature. [Review]

Evidence is presented which suggests that a low-temperature, martensite-like behavior may be quite general in actinide metals and their alloys and compounds. There may be no metastable martensitic embryos in an ..cap alpha..-phase structure of high-purity U, Np, and Pu formed by a diffusion-controlled ..beta.. ..-->.. ..cap alpha.. transformation, and thus no evidence for low-temperature phases. The effect of impurity content on observed low-temperature physical properties of these actinides is noted. It is proposed that impurities may be playing several roles. They may permit an electron redistribution in dilute alloys dependent upon the length of holding time. Experimentally determined values for the electronic contribution to heat capacity and the density of states of U, Np, and Pu should thus vary over a considerable range, as has been observed. Variations in interstitial ordering of impurity atoms with processing may yield stacking variants of each basic close-packed actinide metal structure and thus determine the number and structure of low-temperature phase. 46 references.
Date: May 1, 1976
Creator: Sandenaw, T. A.
System: The UNT Digital Library