44,349 research outputs found
Class Day Address Transcript, 1963: Excellence - What is it?
Transcript of Dr. E. Gardner Jacob\u27s 1963 class day address at Bryant. This year marked Bryant\u27s Centennial Commencement
Phenomenology of - Oscillations Revisited
We revisit the phenomenology of - oscillations in the presence
of external magnetic fields, highlighting the role of spin. We show, contrary
to long-held belief, that the - transition rate need not be
suppressed, opening new opportunities for its empirical study.Comment: 15 pages, REVTeX; revised and rewritten to focus on SM spin-dependent
effects, conclusions persis
Effects of Ionizing Radiation on Solid Rocket Motor Components
Problems which the solid propellant rocket engineer will encounter in designing for long-term storage in a radiation environment are discussed. A summary of present knowledge of the radiation environment is given. Mechanisms of radiation degradation and its effects on tensile properties of propellant binders are discussed qualitatively. Data from a program of irradiation of several propellants is presented. Properties of two of the propellants were changed significantly by doses of the order of 4 x 10(exp 6) rads
Forming blocks speed production of strain gage grids
A tool is designed which facilitates the forming of wire grids used in manufacturing strain gage grids. Flattening the grid wire by a cold working process produces a stabilized grid which can be readily handled for storage or shipment
Loads and aeroelasticity division research and technology accomplishments for FY 1985 and plans for FY 1986
The Langley Research Center Loads and Aeroelasticity Division's research accomplishments for FY85 and research plans for FY86 are presented. The rk under each branch (technical area) will be described in terms of highlights of accomplishments during the past year and highlights of plans for the current year as they relate to five year plans for each technical area. This information will be useful in program coordination with other government organizations and industry in areas of mutual interest
The effect of the Solar motion on the flux of long-period comets
The long-term dynamics of Oort cloud comets are studied under the influence
of both the radial and the vertical components of the Galactic tidal field.
Sporadic dynamical perturbation processes are ignored, such as passing stars,
since we aim to study the influence of just the axisymmetric Galactic tidal
field on the cometary motion and how it changes in time. We use a model of the
Galaxy with a disc, bulge and dark halo, and a local disc density, and disc
scale length constrained to fit the best available observational constraints.
By integrating a few million of cometary orbits over 1 Gyr, we calculate the
time variable flux of Oort cloud comets that enter the inner Solar System, for
the cases of a constant Galactic tidal field, and a realistically varying tidal
field which is a function of the Sun's orbit. The applied method calculates the
evolution of the comets by using first-order averaged mean elements. We find
that the periodicity in the cometary flux is complicated and quasi-periodic.
The amplitude of the variations in the flux are of order 30%. The radial motion
of the Sun is the chief cause of this behaviour, and should be taken into
account when the Galactic influence on the Oort cloud comets is studied.Comment: 8 pages, 9 figures, 3 tables, Accepted MNRA
A characterization of Blaschke addition
A characterization of Blaschke addition as a map between origin-symmetric
convex bodies is established. This results from a new characterization of
Minkowski addition as a map between origin-symmetric zonoids, combined with the
use of L\'{e}vy-Prokhorov metrics. A full set of examples is provided that show
the results are in a sense the best possible
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