3,645 research outputs found

    Computer program determines vibration in three-dimensional space of hydraulic lines excited by forced displacements

    Get PDF
    Computer program determines the forced vibration in three dimensional space of a multiple degree of freedom beam type structural system. Provision is made for the longitudinal axis of the analytical model to change orientation at any point along its length. This program is used by industries in which structural design dynamic analyses are performed

    Calibration of a gamma-ray telescope using tagged position annihilation photons

    Get PDF
    Measurements of detection efficiency, angular resolution, and energy resolution properties of a gamma ray telescope used to study celestial gamma rays from balloon flight altitudes are described. Nearly monochromatic photons produced at the National Bureau of Standards tagged photon facility were used for the calibration. Details of the photon beam configuration and properties and results of the measurements made at photon energies of 15.1 and 31.1 MeV are presented. Finally, the data are compared with a Monte Carlo analysis of the instrument properties

    Propellant dynamic problems in space shuttle vehicles, part 2 Final report

    Get PDF
    Liquid propellant dynamic problems in space shuttle vehicle

    Development of carbon slurry fuels for transportation (hybrid fuels, phase 2)

    Get PDF
    Slurry fuels of various forms of solids in diesel fuel are developed and evaluated for their relative potential as fuel for diesel engines. Thirteen test fuels with different solids concentrations are formulated using eight different materials. A variety of properties are examined including ash content, sulfur content, particle size distribution, and rheological properties. Attempts are made to determine the effects of these variations on these fuel properties on injection, atomization, and combustion processes. The slurries are also tested in a single cylinder CLR engine in both direct injection and prechamber configurations. The data includes the normal performance parameters as well as heat release rates and emissions. The slurries perform very much like the baseline fuel. The combustion data indicate that a large fraction (90 percent or more) of the solids are burning in the engine. It appears that the prechamber engine configuration is more tolerant of the slurries than the direct injection configuration

    On Foreign Language Laboratories

    Get PDF

    Data on Burned District at Salem, Mass.

    Get PDF
    Nature of Buildings Burned - Materials of Original Construction - Assessed Valuation on Land and Buildings - also Insurance on Buildings and Contents, where obtainable. Arranged according to Name of Owners, Street Location and Classes of Buildings. 20 pages.https://digitalcommons.salemstate.edu/fire_documents/1001/thumbnail.jp

    Skeletal Extension, Density and Calcification of the Reef Coral, Montastrea Annularis: St. Croix, U.S. Virgin Islands

    Get PDF
    Parameters of the annual and subannual skeletal growth of 61 Montastrea annularis corals, collected at a variety of shallow depth sites on reefs of St. Croix, U.S. Virgin Islands, are determined by X-radiography and scanning densitometry for each year in the 10-year period, 1970–1979. Extension (linear growth) of the coral skeleton is correlated negatively with bulk density (mass per unit volume) and positively with calcification (mass addition). Density and mass are slightly positively correlated. No one parameter, however, is a perfect predictor of another. At least two parameters, from which the third can be calculated, are required for complete description of coral growth. The variations of parameters of subannual density bands in this study do not convey information additional to those of annual bands.When compared to a pristine site in St. Croix, coral from Round Reef within Christiansted Harbor (a location of past dredging and sewage pollution) have equivalent (and high) extension but significantly lower density and calcification. On the south coast, corals from a location of major dredging activity in the past have relatively low extension and calcification. These growth anomalies are probably pollution related. Collections of corals from one south coast site may have been biased by hurricane effects to nonrepresentative samples

    From splashing to bouncing: the influence of viscosity on the impact of suspension droplets on a solid surface

    Full text link
    We experimentally investigated the splashing of dense suspension droplets impacting a solid surface, extending prior work to the regime where the viscosity of the suspending liquid becomes a significant parameter. The overall behavior can be described by a combination of two trends. The first one is that the splashing becomes favored when the kinetic energy of individual particles at the surface of a droplet overcomes the confinement produced by surface tension. This is expressed by a particle-based Weber number WepWe_p. The second is that splashing is suppressed by increasing the viscosity of the solvent. This is expressed by the Stokes number StSt, which influences the effective coefficient of restitution of colliding particles. We developed a phase diagram where the splashing onset is delineated as a function of both WepWe_p and StSt. A surprising result occurs at very small Stokes number, where not only splashing is suppressed but also plastic deformation of the droplet. This leads to a situation where droplets can bounce back after impact, an observation we are able to reproduce using discrete particle numerical simulations that take into account viscous interaction between particles and elastic energy
    • …
    corecore