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Boundary element analysis of time-dependent inelastic deformation of cracked plates loaded in anti-plane shear
A boundary element analysis, for determining stresses in planar cracked bodies undergoing Mode I or Mode II inelastic deformation, has been recently published by the present authors. One primary advantage of this formulation is that the effect of the crack is incorporated in the kernels of the integral equations. Thus, traction free conditions on the crack boundary are satisfied without discretization of this boundary in a numerical calculation procedure. The inelastic deformation of cracked plates loaded in anti-plane shear (Mode III) is studied in this paper. Modified kernels are used so that the only unknowns in the integral equations are source strengths on the outer boundary of the plate. It is proved that this formulation guarantees traction free cracks as well as single valued displacements on the crack boundary. Numerical results for stresses are presented for various loading histories with the plate material described by an elastic-nonlinear power law creep constitutive model and a stationary crack modelled as a very thin ellipse.
Date:
July 1, 1980
Creator:
Mukherjee, S. & Morjaria, M.
Object Type:
Report
System:
The UNT Digital Library
THE EXPERIMENTAL DESIGN FOR BeO IRAADIATION EXPERIMENTS ORNL 41-8 AND ORNL 41-9
The experimental plan for irradiating BeO pellets in Experiments ORNL 41- 8 and ORNL 41-9 was chosen in accordance with the principles of experimental design. The design is known by statisticians as a 2/sup 5/ factorial experiment confound'' in six replications. Five variables---size, density, grain size, temperature and time--are controlled at two levels to form the basic 2i factorial experiment. The sixth variable, neutron flux, is introduced by confounding on higher-order interactions. An explanation is presented in nontechnical language the means by which the aims of the experimenters and the physical conditions affecting the experiment were utilized in constructing the experimental design. (auth)
Date:
July 18, 1962
Creator:
Gardiner, D.A.
Object Type:
Report
System:
The UNT Digital Library
Two-dimensional nuclear magnetic resonance studies of molecular structure in liquids and liquid crystals
Magnetic couplings between protons, such as through-space dipole couplings, and scalar J-couplings depend sensitively on the structure of the molecule. Two dimensional nuclear magnetic resonance experiments provide a powerful tool for measuring these couplings, correlating them to specific pairs of protons within the molecule, and calculating the structure. This work discusses the development of NMR methods for examining two such classes of problems -- determination of the secondary structure of flexible molecules in anisotropic solutions, and primary structure of large biomolecules in aqueous solutions. 201 refs., 84 figs., 19 tabs.
Date:
July 1, 1991
Creator:
Rucker, S.P.
Object Type:
Report
System:
The UNT Digital Library
Experiment in multiple-criteria energy policy analysis. [Using HOPE (holistic preference evaluation)]
An international panel of energy analysts participated in an experiment to use HOPE (holistic preference evaluation): an interactive parametric linear-programming method for multiple-criteria optimization. The criteria of cost, environmental effect, crude oil, and nuclear fuel were considered according to BESOM: an energy model for the US in the year 2000.
Date:
July 1, 1980
Creator:
Ho, J K
Object Type:
Article
System:
The UNT Digital Library
Fundamental Studies of Erosion for Coal Gasification Systems. Annual Progress Report, 1 November 1979-30 June 1980
The effort in this program is divided between modelling the particle impact event using numerical methods and computer calculations and actual measurement of erosion rates. While the results obtained from each of these activities must be combined to provide an improved understanding of particulate erosion of ductile materials, it is convenient to describe separately the progress in each activity area. The first step in the application of the finite element method to any problem is the dissolution of the continuum into small elements. The intent of this procedure is to use as few total elements as possible and to make the elements small where gradients are large and vice versa. The exact solution for the contact of a rigid cylinder with an elastic surface is available from Hertz. This solution has been compared with the computer results obtained from finite element maps containing 148, 273, and 474 elements. The correlation between the computer results and elastic solution is not good for the map with the fewest elements, but improves as the number of elements increases. Convergence to this exact solution has been examined as a function of the number of map elements as a means of improving the efficiency of …
Date:
July 27, 1980
Creator:
Follansbee, P. S.; Sinclair, G. B. & Williams, J. C.
Object Type:
Report
System:
The UNT Digital Library
Nonlinear spectroscopic studies of interfacial molecular ordering
The second order nonlinear optical processes of second harmonic generation and sum frequency generation are powerful new probes of surfaces. They possess unusual surface sensitivity due to the symmetry properties of the nonlinear susceptibility. In particular, infrared-visible sum frequency generation (SFG) can obtain the vibrational spectrum of sub-monolayer coverages of molecules. In this thesis, we explore the unique information that can be obtained from SFG. We take advantage of the sensitivity of SFG to the conformation of alkane chains to study the interaction between adsorbed liquid crystal molecules and surfactant treated surfaces. The sign of the SFG susceptibility depends on the sign of the molecular polarizability and the orientation, up or down, of the molecule. We experimentally determine the sign of the susceptibility and use it to determine the absolute orientation to obtain the sign of the molecular polarizability and show that this quantity contains important information about the dynamics of molecular charge distributions. Finally, we study the vibrational spectra and the molecular orientation at the pure liquid/vapor interface of methanol and water and present the most detailed evidence yet obtained for the structure of the pure water surface. 32 refs., 4 figs., 2 tabs.
Date:
July 1, 1991
Creator:
Superfine, R.
Object Type:
Report
System:
The UNT Digital Library
Preliminary design data package. Appendix C
The design requirements, design philosophy, method and assumptions, and preliminary computer-aided design of the Near-Term Hybrid Vehicle including its electric and heat power units, control equipment, transmission system, body, and overall vehicle characteristics are presented. (LCL)
Date:
July 25, 1979
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Tests of Bearing Materials for the Experimental Through-Tubes in the Egcr
The four experimental through-tubes provided in the Experimental Gas Cooled Reactor will extend directly through the core of the reactor and penetrate both the upper and lower pressure vessel heads. Each tube is anchored in an upper head nozzle and the bottom end is allowed to slide in a lower head nozzle. This lower nozzle is basically a T'' section that provides bottom access to the through-tube and a side access for the piping which connects the throughtube to the experimenter's cell. Due to differential thermal expansion of the through- tubes relative to the reactor pressure vessel, vertical movement of the through- tube within the T'' section will be experienced. At the same time a horizontal thrust applied to each tube by thermal expansion of the piping to the experimental cell will result in metalto-metal contact between each tube and the lower T'' section. Tests were conducted on three types of bearing material proposed for use on the through-tubes and T'' sections to minimize galling which can be expected to occur. Stellite No. 12 has been demonstrated to be an adequate bearing material for the intended application. (auth)
Date:
July 16, 1962
Creator:
MacPherson, R. E. & Smith, A. M.
Object Type:
Report
System:
The UNT Digital Library
Kilowatt Isotope Power System: component test procedure for the ground demonstration system jet condenser focusing. 77-KIPS-59
This test procedure (No. 404) provides a detailed description of the verification methods which shall be used in the development program to be conducted on the Kilowatt Isotope Power System (KIPS) Jet Condenser to fulfill the requirements of the Ground Demonstration Test Plan, Section 6.4.
Date:
July 15, 1977
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Solar photovoltaic applications seminar: design, installation and operation of small, stand-alone photovoltaic power systems
This seminar material was developed primarily to provide solar photovoltaic (PV) applied engineering technology to the Federal community. An introduction to photoconductivity, semiconductors, and solar photovoltaic cells is included along with a demonstration of specific applications and application identification. The seminar details general systems design and incorporates most known information from industry, academia, and Government concerning small solar cell power system design engineering, presented in a practical and applied manner. Solar PV power system applications involve classical direct electrical energy conversion and electric power system analysis and synthesis. Presentations and examples involve a variety of disciplines including structural analysis, electric power and load analysis, reliability, sizing and optimization; and, installation, operation and maintenance. Four specific system designs are demonstrated: water pumping, domestic uses, navigational and aircraft aids, and telecommunications. All of the applications discussed are for small power requirement (under 2 kilowatts), stand-alone systems to be used in remote locations. Also presented are practical lessons gained from currently installed and operating systems, problems at sites and their resolution, a logical progression through each major phase of system acquisition, as well as thorough design reviews for each application.
Date:
July 1, 1980
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
N and. delta. resonances: an experimental review
Experimental progress in N and ..delta.. resonances since the Oxford baryon conference is reviewed. The review concentrates on hadronic channels, and on developments of the last one or two years. The topics reviewed include the antiproton lifetime; the ..delta../sup + +/ magnetic moment; measurements of ..pi..N elastic and charge-exchange scattering in the ..delta.. region, the eta n threshold region, and the high-mass region; partial wave analyses of ..pi..N ..-->.. ..pi..N; measurements of two-body inelastic ..pi..N scattering; and isobar analyses of ..pi..N ..-->.. ..pi pi..N. 75 references, 3 figures, 4 tables.
Date:
July 1, 1980
Creator:
Kelly, R.L.
Object Type:
Article
System:
The UNT Digital Library
Steady-state and transient radionuclide transport through penetrations in nuclear waste containers
The transport of radionuclides through penetrations in wastes containers is analyzed. Penetrations may result from corrosion or cracks and may occur in the original container material, in degraded or corroded material, or in deposits of corrosion products. In this report we do not consider how these penetrations occur or the characteristics of expected penetrations in waste containers. We are concerned here only with the analytical formulation and solutions of equations to predict rates of mass transfer through penetrations of specified size and geometry. Expressions for the diffusive mass transfer rates through apertures are presented in Chapter 2, and numerical illustrations are presented in Chapter 3. The calculations show that mass transfer through small penetrations in thin-wall containers can be great enough that the penetrated container is no longer an effective barrier for radionuclide release. Use of this theory to calculate mass transfer through thick-wall containers is the subject of a later report. 3 refs., 9 figs.
Date:
July 1, 1986
Creator:
Chambre, P. L.; Lee, W. W. L.; Kim, C. L. & Pigford, T. H.
Object Type:
Report
System:
The UNT Digital Library
H4LM Graphite
A commercial graphite useful in nuclear reactor construction is described. A survey of all currently available sources on chemical and physical properties was made and the information listed. Some data on cost and available sizes are also included. (auth)
Date:
July 5, 1962
Creator:
Merryman, R. G.; Wagner, P. & MacMillan, D. P.
Object Type:
Report
System:
The UNT Digital Library
Bounce-averaged Fokker-Planck code for stellarator transport
A computer code for solving the bounce-averaged Fokker-Planck equation appropriate to stellarator transport has been developed, and its first applications made. The code is much faster than the bounce-averaged Monte-Carlo codes, which up to now have provided the most efficient numerical means for studying stellarator transport. Moreover, because the connection to analytic kinetic theory of the Fokker-Planck approach is more direct than for the Monte-Carlo approach, a comparison of theory and numerical experiment is now possible at a considerably more detailed level than previously.
Date:
July 1, 1985
Creator:
Mynick, H.E. & Hitchon, W.N.G.
Object Type:
Report
System:
The UNT Digital Library
THE PHYSICS DESIGN OF THE EBR-II
The physics design problems of the EBR-II are summarized. These include analysis of the EBR-II engineering design as well as applicable zero-power critical experiments. Pertinent reactor safety problems are reviewed. Safety considerations bearing on normal plant operation and manipulations within the reactor are emphasized. The implication of controlled in-pile meltdown experiments is considered. Irradiation damage and metallurgical phase phenomena are summarized and related to reactivity. The nuclear performance of the system is considered in terms of actual plant operation. The predicted shift of both power and reactivity from core to radial reflector is described. (auth)
Date:
July 1, 1961
Creator:
Loewenstein, W.B.
Object Type:
Report
System:
The UNT Digital Library
CGVIEW: A program to generate isometric and perspective views of combinatorial geometries
The prototype of a graphical debugger for combinatorial geometry (CG) is described. The prototype debugger consists of two parts: a FORTRAN-based view'' generator and a Microsoft Windows application for displaying the geometry. This document describes the code CGVIEW, which comprises the first part of the system. User-specified options permit the selection of an arbitrary viewpoint in space and the generation of either an isometric or perspective view. Additionally, any combination of zones, materials, or regions can be flagged as invisible to facilitate the inspection of internal details of the geometry. In the same manner, an arbitrary body can be cut away from the geometry to facilitate inspection and debugging. Examples illustrating the various options are described.
Date:
July 1, 1992
Creator:
Burns, T.J.
Object Type:
Report
System:
The UNT Digital Library
Analysis of sawtooth relaxation oscillations in tokamaks
Sawtooth relaxation oscillations are analyzed using the Kadomtsev's disruption model and a thermal relaxation model. The sawtooth period is found to be very sensitive to the thermal conduction loss. Qualitative agreement between these calculations and the sawtooth period observed in several tokamaks is demonstrated.
Date:
July 1, 1982
Creator:
Yamazaki, K.; McGuire, K. & Okabayashi, M.
Object Type:
Report
System:
The UNT Digital Library
Hyper filter-fluorescer spectrometer for x rays above 120 keV
An apparatus utilizing filter-fluorescer combinations is provided to measure short bursts of high fluence x-rays above 120 keV energy, where there are no practical absorption edges available for conventional filter-fluorescer techniques. The absorption edge of the prefilter is chosen to be less than that of the fluorescer, i.e., E/sub PRF/ < E/sub F/, contrary to the prior art technique E/sub PRF/ > E/sub F/. In this way, the response function is virtually zero between E/sub PRF/ and E/sub F/ and well defined and enhanced in an energy band of less than 1000 keV above the 120 keV energy.
Date:
July 7, 1981
Creator:
Wang, C. L.
Object Type:
Patent
System:
The UNT Digital Library
Form-stable crystalline polymer pellets for thermal energy storage. Phase 1
The objective of this project was to develop a form-stable, crystalline polymer pellet TES bed material, useful in the 120 to 140/sup 0/C temperature range suitable for solar absorption air conditioning applications. This objective was achieved with a Si-O-Si crosslinked HDPE pellet material, demonstrated to have a high heat of fusion value (46 cal/g, approximately 98% of the HDPE's heat of fusion value prior to crosslinking). Further, on melt/freeze cycling of these TES pellets through 400 cycles in ethylene glycol, they retained nearly 100% of their initial heat of fusion value, and had excellent form-stability characteristics, with little or no inter-particle adhesion. Appropriate testing of this TES pellet material, from analytical (DSC) to a one gallon lab-scale TES unit, and finally to a 60 gallon prototype TES demonstration unit, consistently verified these results. C-C crosslinked PE products, which were slightly inferior to the Si-O-Si crosslinked PE in terms of good heat of fusion and form-stability properties, were also developed and are potential alternatives to the prime PE TES product.
Date:
July 1, 1977
Creator:
Botham, R.A.; Jenkins, G.H.; Ball, G.L. III & Salyer, I.O.
Object Type:
Report
System:
The UNT Digital Library
GAS-COOLED REACTOR PROGRAM QUARTERLY PROGRESS REPORT FOR PERIOD ENDING MARCH 31, 1962
Progress on the gas-cooled reactor program is reported. Separate abstracts were prepared for each of the 14 sections. (M.C.G.)
Date:
July 16, 1962
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
Situational simulations in interactive video
The Westinghouse Hanford Company Advanced Training Technologies section is using situational simulations in several Interactive Video training courses. Two applications of situational simulations will be discussed. In the first, used in the Hanford General Employee Training course, the student evaluates employee's actions in simulations of possible workplace situations. In the second, used in the Criticality Safety course, students must follow well-defined procedures to complete tasks. Design and incorporation of situational simulations will be discussed. 3 refs.
Date:
July 1, 1991
Creator:
Smith, L.J.
Object Type:
Article
System:
The UNT Digital Library
Establishment and maintenance of a coal sample bank and data base
In this Project Status Report for 7/9/89--10/8/89, results of a comparative study of coal sample deterioration in several container types were presented. In April 1990, one year after the initial analyses, the set of analyses was repeated on the most important container types. The new results are included in Table 2. During the current reporting period a total of 42 data printouts were distributed. In addition, 7 special data requests were fulfilled by either search/sort and printout or creation of a data disk, resulting in distribution of limited information on 2083 samples. Several preliminary requests for Sample Bank and Data Base information and price quotations have also been handled.
Date:
July 11, 1990
Creator:
Davis, A.
Object Type:
Report
System:
The UNT Digital Library
Synchrotron x-ray study of physisorbed films of mixtures of Ar and Xe on graphite
Mixtures of Ar and Xe have been studied in most of the submonolayer region of the phase diagram (T,chi,rho), T = temperature, chi = chemical composition, rho = fraction of a monolayer. The basic feature is a large tendency to form ..sqrt.. 3 x ..sqrt.. 3 commensurate alloys (Kr-like structures), but none of the commensurate nor of the incommensurate structures form a chemically ordered alloy at 11 K. Thus the 2D solid can be thought of as a solid consisting of particles of an average size. This allows the study of commensurate-incommensurate phase transition driven by average particle size. The transition is indeed a sharp first order transition taking place through coexisting phases (tau/sub A/ = 1.64 A/sup -1/ and tau/sub B/ = 1.703 A/sup -1/), as was the case for the low temperature pure Kr-system. Another interesting feature is the existence of well correlated liquid-like structures which preserve their correlation over a temperature range of 5 Kelvin or more. This unusual behavior is for chemical compositions where there is coexistence of a commensurate and an incommensurate solid at high temperature.
Date:
July 1, 1982
Creator:
Bohr, J.; Nielsen, M.; McTague, J. P.; Als-Nielsen, J. & Kjaer, K.
Object Type:
Article
System:
The UNT Digital Library
Structural study of multilayered vanadium/nickel superlattices
We have studied the microstructure of V/Ni metallic superlattice, using x-ray and neutron diffraction. We find a sharp and broad rocking curves around the first-order Bragg peak, and attribute them to a columnar structure which gives rise to two modulation structures; one the ordinary layered structure within the columns and the other the averaged modulation structure which produces the sharp rocking peak.
Date:
July 1, 1985
Creator:
Homma, H.; Lepetre, Y.; Murduck, J.M.; Schuller, I.K. & Majkrzak, C.F.
Object Type:
Article
System:
The UNT Digital Library