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309

Jun 21, 2010
06/10

by
Dengler, R. P.; Gladden, H. J.; Hickel, R. O.; Hippensteele, S. A

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Radiation heat transfer characteristics of turbine vane airfoils in water-cooled cascade

Topics: PARALLEL PLATES, SHEAR PROPERTIES, VISCOMETERS, ELASTIC DEFORMATION, VISCOELASTICITY

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390

Jun 1, 2011
06/11

by
Thieme, Lanny G.; Schreiber, Jeffrey G

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The Department of Energy, Lockheed Martin (LM), Stirling Technology Company, and NASA Glenn Research Center (GRC) are developing a high-efficiency Stirling Radioisotope Generator (SRG) for potential NASA Space Science missions. The SRG is being developed for multimission use, including providing spacecraft onboard electric power for NASA deep space missions and power for unmanned Mars rovers. NASA GRC is conducting an in- house supporting technology project to assist in developing the Stirling...

Topics: AXIAL COMPRESSION LOADS, ANISOTROPIC PLATES, SHEAR PROPERTIES, DEFORMATION, BUCKLING, LAMINATES,...

214
214

Jun 15, 2011
06/11

by
Moore, J. M

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The saturnian satellites were imaged by the Voyager spacecraft at sufficient resolutions to reveal landforms that indicate histories of extensional tectonics for several of these bodies. The relationships among landforms on various satellites imply that extensional tectonism is a consequence of several different energy sources. Case histories of several satellites are discussed to illustrate the interaction of various phenomena associated with extensional tectonism.

Topics: CONTINENTS, EARTH CRUST, HEAT TRANSFER, PLANETARY TEMPERATURE, SHEAR PROPERTIES, EARTH MANTLE,...

Using multiple deployments of an 80-element, three-component borehole seismic array stretching from the surface to 2.3 km depth, we examine recordings of chemical explosions to better understand the generation of shear waves by explosive sources. The well is near vertical in the upper 1.5 km and gradually transitions to a dip of 38 degrees at the deepest recording location. The chemical shots are high-velocity chemical shots buried 3-4 m and fired electrically, ranging in size from 5 to 10 lb....

Topics: DTIC Archive, GEOLOGICAL SURVEY RESTON VA, *EXPLOSIONS, CHEMICALS, POSITION(LOCATION), SEISMIC...

Stability of shear flows at high Reynolds number has been one of the cornerstones of hydrodynamic stability. A canonical problem which contains the basic features is that of a shear layer - two streams of different velocity owing past each other with different density. Helmholtz[18] and Kelvin[21] were probably the earliest to consider evolution of disturbances in a stratified vortex sheet. While attempting a more general case Rayleigh[27] approximated the shear layer by piecewise-linear...

Topics: DTIC Archive, WOODS HOLE OCEANOGRAPHIC INSTITUTION MA, *SHEAR PROPERTIES, FLOW, REYNOLDS NUMBER,...

The shear textures that develop in friction stir welds are reviewed and discussed. In all the materials examined, including face centred cubic (fcc), body centred cubic (bcc) and hexagonal close-packed (hcp) materials, friction stir welding produces a predominant shear texture with the close-packed directions aligned with the shear direction (SD) and the close-packed plane normal perpendicular to both the SD and the shear plane normal. This orientation corresponds to the B/BB ideal shear...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *WELDING, *TEXTURE, RECRYSTALLIZATION, REPRINTS,...

This device comprises a flexible sheet member having cross convolutions oriented 45.degree. to the shear vector with spherical reliefs at the convolution junctions. The spherical reliefs are essential to the shear flexibility by interrupting the principal stress lines that act along the ridges of the convolutions. The spherical reliefs provide convolutions in both directions in the plane of the cross-convolution ridges.

Topics: NASA Technical Reports Server (NTRS), ELASTIC SHEETS, FLEXIBILITY, SHEAR PROPERTIES, PATENTS,...

Experimental evidence regarding pressure gradients in Bridgman anvil devices is reviewed and some new experimental data are presented. Although there are many differences in details, all the experimental evidence is found to fit a general pattern. A simple empirical relationship describing the pressure distribution is derived which is consistent with experimental observation. The experimentally determined pressure is used to estimate errors introduced into various types of anvil experiments by...

Topics: DTIC Archive, AIR FORCE CAMBRIDGE RESEARCH LABS HANSCOM AFB MA, *SHEAR PROPERTIES, GEOPHYSICS,...

The long-range goal of our studies is to understand the processes that cause mixing in the ocean. Of particular interest is the turbulence caused by internal wave breaking. Our recent work has revealed strong relationships between finescale shear levels and the intensity of turbulent mixing, and marked spatial variability in the intensity characteristics of the internal wave field. In particular, we have found enhanced finestructure and microstructure adjacent to rough bathymetric structures....

Topics: DTIC Archive, WOODS HOLE OCEANOGRAPHIC INSTITUTION MA, *INTERNAL WAVES, *LITTORAL ZONES,...

A composite element is presented which includes the effects of warping and offset shear centers. It is shown to be mathematically consistent with thin walled open beam theory and can be incorporated into any structural analysis program by use of NASTRAN'S standard elements. A numerical example analyzing the vibration of a channel beam is presented, and, by using the composite element, the numerical results agreed well with theoretical data.

Topics: NASA Technical Reports Server (NTRS), BEAMS (SUPPORTS), SHEAR PROPERTIES, WARPAGE, STRUCTURAL...

Shear coaxial injectors are a common injector type for liquid-rocket-propulsion applications and can be found in many oxygen/hydrogen engines. These injectors rely on the shear between an outer lower-density, high-velocity annulus and a higher-density, low-velocity inner jet to atomize and mix the propellants. Because of the dense-jet core, the optical densities of these sprays are high, particularly near the injector where primary atomization and flame holding take place. The large optical...

Topics: DTIC Archive, AIR FORCE RESEARCH LAB EDWARDS AFB CA, *INJECTORS, *RADIOGRAPHY, ENGINES, SHEAR...

This memorandum report examines the possibility of shear stabilization of a cylindrically symmetric mirror plasma. (Author)

Topics: DTIC Archive, Manheimer,W M, NAVAL RESEARCH LAB WASHINGTON DC, *PLASMAS(PHYSICS), SHEAR PROPERTIES,...

239
239

Jun 15, 2011
06/11

by
Nikishin, A. M.; Milanovsky, E. E

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During the process of continental rifting on Earth, the lower ductile crust stretches, forming a neck, while the upper brittle crust is broken in blocks by faults, and the blocks sink down the thinned lower crust; if the stretching continues, the neck may break and a newly originated oceanic crust is formed at this place. The rift system structure depends on the depth of the boundary surface between the brittle crust and the ductile crust, the litospheric thickness, the tension value, etc.. The...

Topics: BRITTLENESS, MOUNTAINS, COLORADO RIVER (NORTH AMERICA), EARTH CRUST, GEOLOGICAL FAULTS,...

Topics: DTIC Archive, CORPS OF ENGINEERS WASHINGTON DC, *EARTH DAMS, *ROCKFILL DAMS, SHEAR PROPERTIES,...

The Analysis of in situ and satellite data with model output to investigate the stratification and shear of the Philippine seas at sub-meso to meso-scales to regional scales, so as to understand their relationship to the larger scale ocean and monsoon forcing. This work contributes to the Characterization and Modeling of Archipelago Strait Dynamics DRI [PhilEx] goal: to enhance our understanding of the oceanographic processes and features arising in and around straits, and improve our...

Topics: DTIC Archive, LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY, *STRAITS, ARCHIPELAGOES, PHILIPPINES,...

This report describes the work carried out under grant number N00014-10-1-0910 Distorted Turbulent Flow in a Shear Layer at Florida Atlantic University. The project was in collaboration with Dr. William Devenport of Virginia Tech, who has carried out wind tunnel measurements on the rotor system described in this report as part of a companion project. The overall objective of this study is to measure and predict the sound radiation from a rotor operating near a wall in a wind tunnel. Results are...

Topics: DTIC Archive, FLORIDA ATLANTIC UNIV BOCA RATON, *TURBULENT FLOW, NOISE, ROTORS, SHEAR PROPERTIES,...

Our work focuses on understanding the frequency and depth dependence of compressional wave attenuation and developing new inversion schemes for shear wave properties. Our initial investigations have indicated that water-borne acoustic arrival properties such as their Airy Phase are sensitive to sediment shear properties. Our major emphasis this year has been to develop and test inversion schemes for simultaneous estimation of compressional and shear properties.

Topics: DTIC Archive, RHODE ISLAND UNIV NARRAGANSETT DEPT OF OCEAN ENGINEERING, *ACOUSTIC PROPERTIES,...

YVETTE is a free-fall instrument package which measures temperature, conductivity, pressure, and horizontal velocity in the upper ocean. From the direct measurements, the density, rho, and gradient (or differenced) quantities such as Brunt-Vaisala frequency, N=-(g/rho) (partial derivative rho/partial derivative z), and the square of the vertical shear, S squared=(partial derivative u/partial derivative z) squared +(partial derivative v/partial derivative z) squared, can be calculated. Data from...

Topics: DTIC Archive, Newman,F C, SCIENCE APPLICATIONS INC MCLEAN VA, *Oceanographic data, Shear...

Ultra-intense laser-matter interaction experiments (greater than 10(18) W/cm(2)) with dense targets are highly sensitive to the effect of laser noise (in the form of pre-pulses) preceding the main ultra-intense pulse. These system-dependent pre-pulses in the nanosecond and/or picosecond regimes are often intense enough to modify the target significantly by ionizing and forming a plasma layer in front of the target before the arrival of the main pulse. Time resolved interferometry offers a...

Topics: DTIC Archive, MICHIGAN UNIV ANN ARBOR, *INTERFEROMETRY, *PLASMA DIAGNOSTICS, *SHEAR PROPERTIES,...

The new version of TM5-1300 has made significant revisions to the design provisions for shear reinforcing in blast resistant concrete structures. These changes allow more flexibility in the use of stirrups in lieu of lacing for limited deflection applications. This paper discusses these new provisions and compares them with previous requirements. A commentary on the significance of these changes is also included.

Topics: DTIC Archive, CORPS OF ENGINEERS HUNTSVILLE AL, *REINFORCED CONCRETE, *BLAST, *SHEAR PROPERTIES,...

Work carried out under this grant has involved the study of the following problems: (1) Flow on non-Newtonian fluids of the rate type between two parallel plates rotating with different angular speeds about a common axis. (2) Flow of non-Newtonian fluids of the integral type between parallel plates rotating about distinct axes. (3) Flow of non-Newtonian fluids due to torsional and longitudinal oscillations. (4) Flow of non-Newtonian fluids in pipes of varying cross-sections. (5) Flow of shear...

Topics: DTIC Archive, Rajagopal, Docotr, PITTSBURGH UNIV PA, *VELOCITY, *AXES, *FLOW, SHEAR PROPERTIES,...

The Regional Arctic System Model (RASM) is used to investigate the process and frequency of extreme sea ice shear deformation events resulting in pycnocline upwelling due to Ekman pumping as described in McPhee et al. (2005). RASM is a fully coupled land, atmosphere, sea ice, and ocean model with high spatial and temporal resolution. Time series analysis of the upper ocean temperature structure, basal melt rate, total deformation rate, and ice-ocean stress curl yield the identification of...

Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *DEFORMATION, *OCEANOGRAPHIC DATA, *SEA ICE,...

Traditional concrete blast resistant structures are poured-in-place construction. Modem conventional buildings are often pre-cast construction due to economy of time and in some cases labor costs. The questions is, can pre-cast construction be appropriate for blast resistant facilities? The answer is yes, particularly in far range design. Buildings located at barricaded intraline distance out to inhabited building distance are all candidates for pre-cast concrete construction. These distances...

Topics: DTIC Archive, DEPARTMENT OF DEFENSE EXPLOSIVES SAFETY BOARD ALEXANDRIA VA, *BLAST, *PRECAST...

The project funded under U.S. ARO grant DAAG055-97-1-0265 was directed toward the development and use of fluorescent diagnostics in the understanding of the heating and evaporation of droplets and sprays, the role of shear in atomization processes, and the application of fluorescent diagnostics to various aerodynamic problems. At the University of Texas at Dallas (UTD), the following fluorescent diagnostic projects were undertaken: (1) real time measurements of shear (possibly in fuel spray...

Topics: DTIC Archive, Melton, Lynn A, TEXAS UNIV AT DALLAS RICHARDSON, *FLUORESCENCE, *FUEL SPRAYS, SHEAR...

The reflection of straight-crested flexural waves at the edge of a semi-infinite plate was studied in terms of a 2-dimensional plate theory. The analysis indicated that, in general, a flexural wave propagated toward the edge at an arbitrary angle of incidence produces 3 reflected waves: a slow and fast flexural wave and a shear wave. Special cases involving normal, oblique, and grazing incidences are investigated.

Topics: DTIC Archive, Kane, T. R., COLUMBIA UNIV NEW YORK, *FLEXURAL PROPERTIES, *ELASTIC WAVES, SHEAR...

The influence of shear rate on cell cultures was determined. Cells were cultured on a flat substrate in a specially designed flow chamber in which shear rate is known and controlled.

Topics: NASA Technical Reports Server (NTRS), CELLS (BIOLOGY), CULTURE TECHNIQUES, FLUID MECHANICS, FLOW...

A method is presented for computing stresses in the vicinity of a long cylindrical cavity in an infinite, elastic, isotropic, homogeneous medium when the cavity is enveloped by a plane stress wave traveling in a direction perpendicular to its axis. Hoop stresses around the cavity bound ary were computed for the passage of a wave of dilation and a wave of pure shear; the stresses in the medium away from the boundary were com puted for a wave of dilation. Initially the stress behind the incident...

Topics: DTIC Archive, Paul, Stanley L, ILLINOIS UNIV AT URBANA, *SHOCK WAVES, SHEAR PROPERTIES, CAVITIES,...

Walls in light-frame construction resist in-plane shear forces, known as racking forces, by the interaction of the sheathing diaphragm and wood frame through the fasteners. Wall performance tests provide racking strength for a particular sheathing, fastener and wood frame configuration. Small-scale shear wall length (aspect ratio) on racking resistance, (2) additive nature of single-sided walls to determine racking resistance of double-sided walls, and (3) relative racking resistance of...

Topics: DTIC Archive, Patton-Mallory,M, FOREST PRODUCTS LAB MADISON WI, *SHEAR PROPERTIES, *WALLS,...

This paper documents recent and past developments with respect to the seven-hole pressure probe. Included are discussions on probe design, construction, calibration, and measurement capabilities. The effects on probe measurements in shear flows, as well as methods of correction, are also included. Finally, research applications in the measurement of unknown flowfields are presented. As shown, the seven-hole pressure probe is a valuable and highly accurate device for qualitatively or...

Topics: DTIC Archive, Reed,L, AIR FORCE ACADEMY CO DEPT OF AERONAUTICS, *PROBES, *PRESSURE MEASUREMENT,...

The interfacial conditions for a cylindrical vortex sheet or a cylindrical fluid layer obtained earlier are examined further for the case of incompressible fluids. Only temporal perturbations are considered. Unlike the single role of destabilization played by the velocity in two-dimensional stratified flows or axisymmetric jet flows, the rotating velocity in vortex motions plays a dual role in flow stability. The radial velocity gradient generates tangential shear and the fluid rotation creates...

Topics: DTIC Archive, Fung,Y T, NAVAL RESEARCH LAB WASHINGTON DC, *VORTICES, SHEAR PROPERTIES, STABILITY,...

Results from a program which studied the processes used in the manufacture of fiberglass roving and preimpregnated roving made from it are presented. The program was composed of two independent phases. Phase I was a critical analysis of the various steps involved in the manufacture of glass roving from the point of drawing glass filaments to packaging and shipment of the product. The purpose was to establish optimum procedures which would lead to a retention of a greater proportion of the...

Topics: DTIC Archive, AEROJET-GENERAL CORP AZUSA CA, *SHEAR PROPERTIES, EXPERIMENTAL DATA, MATERIALS,...

An approach for synthesizing buckling results and behavior for thin balanced and unbalanced symmetric laminates that are subjected to uniform axial compression loads and elastically restrained against inplane expansion, contraction, and shear deformation is presented. This approach uses a nondimensional analysis for infinitely long, flexurally anisotropic plates (coupling between bending and twisting) that are subjected to combined mechanical loads and is based on nondimensional parameters. In...

Topics: NASA Technical Reports Server (NTRS), AXIAL COMPRESSION LOADS, ANISOTROPIC PLATES, SHEAR...

The major goal of this research is to understand charged biomolecules in a biofluid flowing through a micro- or nanochannel interact with a charged surface in the presence of an applied electric field parallel to the wall. In the third and final year of this work, the experimental effort at Georgia Tech has focused on studying the dynamics of colloidal particles, as a model of large charged biomolecules, in combined electroosmotic and Poiseuille flow through microchannels, i.e., in the presence...

Topics: DTIC Archive, OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS, *BIOMOLECULES, *CHANNELS,...

Improvised Explosive Devices (IEDs) have evolved over the years to become one of the main causes of casualties and fatalities in recent conflicts. One area of research focuses on the improvement of blast attenuation using Shear Thickening Fluid (STF). The STF is a dilatant material, which displays non-Newtonian characteristics in its unique ability to transit from a low viscosity fluid to a high viscosity fluid. Although empirical research and computational models using the non-Newtonian flow...

Topics: DTIC Archive, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *IMPROVISED EXPLOSIVE DEVICES, BLAST,...

Topics: DTIC Archive, Tobolsky, A V, TEXTILE RESEARCH INST PRINCETON NJ, *SHEAR MODULUS, *POLYETHYLENE,...

Traction measurements under starved elastohydrodynamic conditions were obtained for a point contact geometry. Simultaneous measurements of the film thickness and the locations of the inlet lubricant boundary were made optically. The thickness of a starved film for combination rolling and sliding conditions varies with the location of the inlet boundary in the same way found previously for pure rolling. A starved film was observed to possess greater traction than a flooded film for the same...

Topics: NASA Technical Reports Server (NTRS), ELASTOHYDRODYNAMICS, FILM THICKNESS, FRICTION MEASUREMENT,...

The viscoplastic flow of a long thick-walled tube with subjected to internal pressure and has its ends restrained from motion in the axial direction is investigated. The material of the tube is rigid-viscoplastic and incompressible. The pressure required to produce a specified expansion of the tube is calculated for two examples. In the former the effect of different viscosity coefficients is observed. In the latter example a comparison is made of the effects of perfect plasticity, viscosity...

Topics: DTIC Archive, Appleby, Edmund J, ILLINOIS INST OF TECH CHICAGO, *COMPRESSION, *VISCOELASTICITY,...

The formulation of a fully compatible general quadrilateral plate bending element is described. The element is assembled from four partially constrained linear curvature compatible triangles, arranged so that no mid-side nodes occur on the external edges of the quadrilateral; thus, the resulting element has only 12 degrees of freedom. Also described is a simple shear distortion mechanism which may be incorporated into the element without changing its basic structure. Results are presented for...

Topics: DTIC Archive, Clough, Ray W, CALIFORNIA UNIV BERKELEY, *BENDING, *PLATES, *QUADRATIC EQUATIONS,...

Two well known thin shell theories are used to evaluate and compare shears and moments at the juncture of two pressurized cylindrical shells. For highly pressurized cylinders with large radius-thickness ratios the numerical results indicate that nonlinear coupling effects of pressure significantly influence computed values of discontinuity shears and moments.

Topics: DTIC Archive, Wilson, Paul E, GENERAL DYNAMICS/ASTRONAUTICS SAN DIEGOCA, *STRUCTURAL ANALYSIS,...

The shear field measured by the W1 mooring during JASIN 1978 was analyzed, using deterministic statistical approaches. A significant fraction of the shear variance was at the semidiurnal tidal frequency. In order to determine whether the shear was associated with internal wave trains propagating from single or multiple sources, the eccentricity of the shear ellipse was analyzed. During seven periods of intense shear, the minor-to-major axis ratio was consistent with the theoretically predicted...

Topics: DTIC Archive, Rubenstein,D M, SCIENCE APPLICATIONS INC MCLEAN VA, *Ocean currents, Shear...

Marine cables often comprise an integral part of a larger structural system, such as an offshore drilling platform. They are also used to support marker buoys, as well as anchored or towed instrument arrays. Consequently, the resonant flow-induced oscillations of these cables, caused by vortex shedding, are extremely undesirable because of the associated damaging phenomena. The present study, which employs hot wire anemometry as the principal investigative tool, was undertaken to examine the...

Topics: DTIC Archive, Peltzer, R. D., NAVAL RESEARCH LAB WASHINGTON DC, *SHEAR PROPERTIES, *VORTEX...

An equation for the shear modulus for nonisotropic, open-celled foams in the plane transverse to the elongation (rise) direction is derived using an elongated Kelvin foam model with the most general geometric description. The shear modulus was found to be a function of the unit cell dimensions, the solid material properties, and the cell edge cross-section properties. The shear modulus equation reduces to the relation derived by others for isotropic foams when the unit cell is equiaxed.

Topics: NASA Technical Reports Server (NTRS), FOAMS, MODULUS OF ELASTICITY, ELONGATION, SHEAR PROPERTIES,...

The contract is in support of research on the structure and stability of reacting compressible mixing layers. The research performed under this contract has resulted in our learning a great deal about the structure and stability of reacting compressible mixing layers.

Topics: DTIC Archive, Grosch, Chester, OLD DOMINION UNIV RESEARCH FOUNDATION NORFOLK VA, *STABILITY,...

The long-term goal of this project is to quantify the role of turbulence and fine scale vertical shear and buoyancy on the formation, evolution, and breakdown of thin phytoplankton layers. Particular attention is given to understanding the relationship of the space and time statistics of the physical fields to that of the phytoplankton thin layers

Topics: DTIC Archive, MASSACHUSETTS UNIV DARTMOUTH SCHOOL FOR MARINE SCIENCE AND TECHNOLOGY, *TURBULENCE,...

Characteristics of turbulence in the lower and middle troposphere over Owens Valley have been examined using aircraft in situ measurements obtained from the Terrain-Induced Rotor Experiment. The two events analyzed in this study are characterized by a deep turbulent layer from the valley floor up to the midtroposphere associated with the interaction between trapped waves and an elevated shear layer. Kelvin-Helmholtz (KH) instability develops above the mountaintop level and often along the wave...

Topics: DTIC Archive, NAVAL RESEARCH LAB MONTEREY CA, *SHEAR PROPERTIES, *TURBULENCE, *LAYERS, GRAVITY...

The effect of fuselage-induced upwash on the flapwise motion of a hinged rotor blade is considered. The typical upwash field is simulated through the flow produced by a moving point source. The resulting blade response is then approximated by its rigid flapping and first bending mode. The perturbation blade pitch variation required to alleviate its response to the upwash in the sense of either reducing the increased hub shear or minimization of the blade overall time averaged deflection, is...

Topics: NASA Technical Reports Server (NTRS), DEFLECTION, FLAPPING HINGES, ROTOR AERODYNAMICS, ROTORS,...

Annealed, 0.031 in. and 0.050 in. thick, mill annealed (2250 F, water quench), L-605 (Haynes Alloy No. 25, Haynes Stellite Co.) was cleaned by the methods given and then spot welded. The 0.031 in. thick sheet was welded according to the schedule given, and the 0.050 in. thick according to the schedule. The results from tests with spot welds in mill-annealed and re-annealed (1975 F, 30 minutes, rapid air cool) conditions are shown. These data show that spot weld strengths optimize when...

Topics: DTIC Archive, Alesch, C W, GENERAL DYNAMICS SAN DIEGO CA CONVAIR DIV, *WELDS, *COBALT ALLOYS, SHEAR...

241
241

Jul 12, 2010
07/10

by
Hutchings, J. B

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The considerable contributions of IUE to understanding the composition, stellar evolution, interstellar medium, and extinction of the Magellanic Clouds are discussed and compared with those for the galaxy. Future directions for UV work are suggested.

Topics: GRAPHITE-EPOXY COMPOSITES, SHEAR PROPERTIES, STRESS-STRAIN RELATIONSHIPS, ANGLES (GEOMETRY),...

Research performed under this AFOSR contract addressed two aspects of gravity wave excitation by unstable shear layers in the atmosphere; the non-linear excitation of radiating gravity waves and the response of the mean velocity profile to gravity wave growth and decay. Gravity excitation via the nonlinear interaction of two smaller-scale Kelvin-Helmholtz (KH) instabilities was found to be significantly faster than that predicted by linear stability analysis, accounting for the geophysical...

Topics: DTIC Archive, Fritts,David C, PHYSICAL DYNAMICS INC TORRANCE CALIF, *GRAVITY WAVES, SHEAR...

Efficient and accurate elements for the large displacement, transient analysis of shells have been developed. The essential feature of these elements is the use of minimal quadrature, which consists of 1 point quadrature in the 4-node quadrilateral or the 3-node triangle, and 2x2 quadrature in the 9-node element. Since these minimal quadrature elements possess spurious singular modes, their use requires effective control of these modes. A control procedure has been developed which satisfies...

Topics: DTIC Archive, Belytschko,Ted, NORTHWESTERN UNIV EVANSTON IL DEPT OF CIVIL ENGINEERING, *STRUCTURAL...