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Elastic-wave radiation from spherical sources

Description: The radiation of spherical compressional waves from a spherical cavity in an ideal elastic solid is treated. The equations for the radiation source and field are written in terms of the reduced-displacement potential. The source equation is studied in terms of characteristic frequencies, corresponding periods and wavelengths, and damping. The field equations for the stresses, strains, radial displacement, etc., are reviewed with regard to the transitions between the near and far fields. The nat… more
Date: December 7, 1979
Creator: Rodean, H.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Lower hybrid heating associated with mode conversion on the Wisconsin octupole

Description: This thesis addresses the following key issues in the lower hybrid frequency range: 1. What are the importent physics aspects of wave propagation and heating in an experimental situation. 2. How effective is plasma heating in the complex magnetic field configuration of the octupole. Experimental work is accomplished by launching 1-10ms pulses of up to 40kW of radio frequency power at 140MHz corresponding to the hot plasma lower hybrid resonance in the octupole. A diploe antenna which is moveabl… more
Date: August 1, 1979
Creator: Owens, T. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wave propagation in viscoelastic media

Description: The mathematical formulations of the wave propagation problem in a linear viscoelastic solid are reviewed from the point of view of constitutive equations and the theory of linear physical systems. Various general results from the theory of propagating singular surfaces and from the mathematical theory of hyperbolic equations are applied to the analysis of the wave propagation process. The impulse responses of three viscoelastic media are analyzed by use of asymptotic methods. The three materia… more
Date: July 18, 1979
Creator: Chin, R.C.Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Spherical wave propagation in elastic media and its application to energy coupling for tamped and decoupled explosions

Description: The effects of variation in source and medium properties upon near- and far-field spectra for elastic waves are examined theoretically by considering spherical wave propagation in unbounded elastic media. This type of analysis, although idealized, provides insight into the relative effects of the various source and medium parameters on both tamped and decoupled explosions. It also provides a basis for interpreting both field and laboratory experimental data obtained during spherical wave propag… more
Date: January 26, 1979
Creator: Larson, D.B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Xenon shock waves driven by high magnetic fields

Description: Magnetic fields in the range 0.2 to 2.0 MG produce shocks in 0.1 to 1.0 atmosphere xenon gas which have shock mach numbers as high as 100. Using pulsed x-ray and other diagnostics, the studies of velocity, compression, and luminosity are in good agreement with a simple snowplow theory. In some of the experiments, ultraviolet radiation from the shocked xenon produces luminous precursors and interactions with the metal walls of the shock tube. The addition of an ultraviolet absorbing organic impu… more
Date: May 1, 1979
Creator: Shearer, J.W.; Beasley, J.W.; Reyenga, A. & Steinberg, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ray and wave optics of integrable and stochastic systems

Description: The generalization of WKB methods to more than one dimension is discussed in terms of the integrability or non-integrability of the geometrical optics (ray Hamiltonian) system derived in the short-wave approximation. In the two-dimensional case the ray trajectories are either regular or stochastic, and the qualitative differences between these types of motion are manifested in the characteristics of the spectra and eigenfunctions. These are examined for a model system which may be integrable or… more
Date: July 1, 1979
Creator: McDonald, S. W. & Kaufman, A. N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of ventilation systems subjected to explosive transients: initial analysis and proposed approach. [Deflagration; detonation; transition from deflagration to detonation]

Description: This report describes an initial study of explosive pressure transients and their propagation through ventilation systems. The objective of this study is to organize the required calculations into a computer code that is highly user-oriented and will predict explosive-induced gas dynamics within a ventilation system. The explosive process is subdivided into three regimes - deflagration, detonation, and transition from deflagration to detonation. Equations describing each process and suggested p… more
Date: August 1, 1979
Creator: Gregory, W. S.; Smith, P. R.; Bolstad, J. W. & Duerre, K. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Self-consistent kinetic theory of stochasticity

Description: It is argued that renormalized kinetic theory is the appropriate tool with which to study macroscopic properties of stochastic systems. Functional techniques are described which afford a self-consistent description of nonlinear excitation, propagation, and dielectric response of fluctuations in the stochastic regime.
Date: August 1, 1979
Creator: Krommes, John A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-energy air shock study in steel and grout pipes

Description: Voitenko compressors are used to generate 43 mm/..mu..s air shocks in both a steel and a grout outlet pipe containing ambient atmospheric air. Fiber-optic ports provide diaphragm burst times, time-of-arrival (TOA) data, and velocities for the shock front along the 20-mm-ID exit pipes. Pressure profiles are obtained at higher enthalpy shock propagation than ever before and at many locations along the exit pipes. Numerous other electronic sensors and postshot observations are described, as well a… more
Date: October 5, 1979
Creator: Glenn, H. D.; Kratz, H. R.; Keough, D. D.; Duganne, D. A.; Ruffner, D. J.; Swift, R. P. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Discontinuity effects on radial cavity transmission lines

Description: Pulse propagation in radial cavity transmission lines such as those found on a radial line accelerator is considered. Specifically, the effects of discontinuities along the line are examined in detail. It is found that previous analyses of such effects have been incorrect, and here two alternate solution techniques are presented. Depending upon the parameters of such a radial line, the discontinuity effects considered here may or may not be significant; however, if they are significant, it is r… more
Date: April 1, 1979
Creator: Seidel, D.B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Reflection and transmission of fluid transients at an elbow

Description: A fundamental problem in the analysis of fluid-filled pipeline systems containing various types of joints and fittings (such as tees, elbows, U-joints and omega-bends) arises when the effects of such structural parts on the propagation of pressure transients through the system are considered. Often, all that is desired is a simple characterization of these discontinuities in terms of reflection and transmission pressure coefficients that can be incorporated into one-dimensional pressure transie… more
Date: January 1, 1979
Creator: Valentin, R.A.; Phillips, J.W. & Walker, J.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Phonon scattering in metallic glasses

Description: The purpose of this article is to review some recent theoretical and experimental developments in the study of metallic glasses at temperatures near or below 1K. In this temperature regime, it appears that practically all glasses, whether metallic or insulating, behave in a similar fashion. The fact that such similarities occur, despite substantial structural differences between metallic and insulating glasses, constitutes a major theoretical challenge. This challenge, however, is not directly … more
Date: January 1, 1979
Creator: Black, J.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Method of optimal truncation: a new t-matrix approach to elastic wave scattering

Description: A family of matrix theories of elastic wave scattering is derived, and one, which is in a certain sense optimal, is developed. Called the method of optimal truncation (MOOT), it results from a minimum principle and can be shown to yield a convergent sequence of approximations. Numerical results for scattering cross-sections for longitudinal incident waves with ka less than or equal to 10 from fixed rigid obstacles and voids with axial symmetry are obtained using MOOT, and are compared with resu… more
Date: January 1, 1979
Creator: Visscher, W.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Seismic monitoring: a unified system for research and verifications

Description: A system for characterizing either a seismic source or geologic media from observational data was developed. This resulted from an examination of the forward and inverse problems of seismology. The system integrates many seismic monitoring research efforts into a single computational capability. Its main advantage is that it unifies computational and research efforts in seismic monitoring. 173 references, 9 figures, 3 tables.
Date: February 6, 1979
Creator: Thigpen, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ICRF heating and wave generation in the ATC tokamak. Part 1: wave generation, propagation and absorption

Description: Experimental results and their theoretical interpretations of rf heating experiments in the ion cyclotron range of frequencies are presented. The presentation is in two parts, with this part describing the experimental facilities and characteristics of fast compressional Alfven waves in the tokamak, and a subsequent paper which will deal with the pricipal heating results. It is shown that a simple coupling structure which consists essentially of a semi-circular metal strip and a pair of bumper … more
Date: April 1, 1979
Creator: Takahashi, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Average structure of the upper earth mantle and crust between Albuquerque and the Nevada Test Site

Description: Models of Earth structures were constructed by inverting seismic data obtained from nuclear events with a 1600-m-long laser strain meter. With these models the general structure of the earth's upper mantle and crust between Albuquerque and the Nevada Test Site was determined. 3 figures, 3 tables.
Date: August 1, 1979
Creator: Garbin, H.D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hydromagnetic waves in high. beta. plasmas

Description: The wave propagation and damping properties in a collisionless thermal plasma for which ..beta.., the ratio of the plasma pressure to the magnetic pressure, is much greater than unity are determined. We achieve this by solving the full collisionless dispersion relation as an expansion in 1/..beta... To do this we develop a set of iteration methods which converge to this solution. We illustrate these results with two applications, the trapping of cosmic rays in supernovae remnants and the collis… more
Date: February 1, 1979
Creator: Foote, E.A. & Kulsrud, R.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Optimum frequencies for regional detection of cavity-decoupled explosions

Description: The natures of compressional (P) waves that originate in the crust, propagate in the crust and upper mantle, and are observed as Pg, Pn, and anti P waves at regional distances are examined. The discussion includes the observed variations of amplitude with epicentral distance for these waves as well as an estimate of values for the specific dissipation function Q/sub ..cap alpha../ in different regions. Studies were made on theoretical source and propagation functions for direct, reflected, and … more
Date: March 21, 1979
Creator: Rodean, H.C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wave propagation in a dc superconducting cable. Part I: analysis

Description: A dc superconducting cable design consisting of four concentric metallic cylinders, of which two carry the load current and two comprise the cryogenic enclosure was studied. When a transient voltage is impressed across such a cable, the major dielectric may not be fully stressed to its design value, and unwanted voltage stresses may develop across other parts of the cable. The surge-voltage propagation characteristics of a four-conductor dc superconducting cable for a step-function input voltag… more
Date: January 1, 1979
Creator: Chowdhuri, P. & Mahaffy, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Technical manual: operation and equipment instructions for in situ impulse test

Description: This manual describes the test equipment and procedures for a new field test which determines the shear modulus of a soil deposit at strain levels equivalent to those experienced during actual earthquakes. Results from this test are typically used as input parameters to response analyses for evaluating local soil effects during earthquake shaking. The test employs a cross-hole wave propagation procedure with velocity transducers located in closely spaced adjacent borings. Clear, consistent, and… more
Date: November 1, 1979
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Computer modeling of inelastic wave propagation in porous rock

Description: Computer modeling of wave propagation in porous rock has several important applications. Among them are prediction of fragmentation and permeability changes to be caused by chemical explosions used for in situ resource recovery, and the understanding of nuclear explosion effects such as seismic wave generation, containment, and site hardness. Of interest in all these applications are the distance from the source to which inelastic effects persist and the amount of porosity change within the ine… more
Date: January 3, 1979
Creator: Cheney, J. A. (Univ. of California, Davis); Schatz, J. F. & Snell, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Transverse resonances of periodically widened cyclindrical tubes with circular cross section

Description: The transverse resonances of the electromagnetic field in periodic cylindrical cavities connected by concentric side tubes are calculated for arbitrary azimuthal mode numbers by expansion of the Hertz potentials in subregions bounded by coordinate surfaces. The expansion coefficients are determined by matching of the tangential field components across the common surfaces of the subregions. Resonances are characterized by the existence of solutions of the homogeneous wave equation in the absence… more
Date: September 1, 1979
Creator: Zotter, B. & Bane, K.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Anisotropic constitutive equation for use in finite difference wave propagation calculations. [Incorporation into TOODY code]

Description: An anisotropic constitutive relation was incorporated into the Lagrangian finite-difference wavecode TOODY. The details of the implementation of the constitutive relation in the wavecode and an example of its use are discussed. 4 figures, 1 table.
Date: May 1, 1979
Creator: Swegle, J.W. & Hicks, D.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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