55,154 research outputs found
Aerospace vehicle
A dual structure aerospace vehicle is described which has an aeroshell structure and an internally disposed separable and reusable integral tank/thrust structure. The tank/thrust structure is inuslated for cryogenic fuels and the cavity within aeroshell is insulated from the tank/thrust structure. An internal support ring within the cavity serves as an attachment for lugs on the tank/thrust structure via double hinges. The aft end of tank/thrust structure is provided with rocket engines and exit nozzles with a trunnion supporting the tank/thrust structure within the aeroshell
Feynman-Jackson integrals
We introduce perturbative Feynman integrals in the context of q-calculus
generalizing the Gaussian q-integrals introduced by Diaz and Teruel. We provide
analytic as well as combinatorial interpretations for the Feynman-Jackson
integrals.Comment: Final versio
Daze fasteners
A daze fastener system for connecting two or more structural elements wherein the structural elements and fastener parts have substantially different coefficient of thermal expansion physical property characteristics is employed in this invention. By providing frusto-conical abutting surfaces between the structural elements and fastener parts any differences in thermal expansion/contraction between the parts is translated to sliding motion and avoids deleterious thermal stresses in the connection. An essential feature for isotropic homogeneous material connections is that at least two sets of mating surfaces are required wherein each set of mating surfaces have line element extensions that pass through a common point
Theoretical photodetachment cross section for the negative atomic oxygen ion
Theoretical photodetachment cross section for negative atomic oxygen io
Dynamics of immersed molecules in superfluids
The dynamics of a molecule immersed in a superfluid medium are considered.
Results are derived using a classical hydrodynamic approach followed by
canonical quantization. The classical model, a rigid body immersed in
incompressible fluid, permits a thorough analysis; its effective Hamiltonian
generalizes the usual rigid-rotor Hamiltonian. In contrast to the free rigid
rotor, the immersed body is shown to have chaotic dynamics. Quantization of the
classical model leads to new and experimentally verifiable features. It is
shown, for instance, that chiral molecules can behave as "quantum propellers":
the rotational-translational coupling induced by the superfluid leads to a
nonzero linear momentum in the ground state. Hydrogen peroxide is a strong
candidate for experimental detection of this effect. The signature is a
characteristic splitting of rotational absorption lines. The 1_{01} --> 1_{10}
line in hydrogen peroxide, for example, is predicted to split into three lines
separated by as much as 0.01 cm^{-1}, which is about the experimental
linewidth.Comment: 10 pages, 3 figure
Generalized virial theorem in Palatini gravity
We use the collision-free Boltzmann equation in Palatini
gravity to derive the virial theorem within the context of the Palatini
approach. It is shown that the virial mass is proportional to certain
geometrical terms appearing in the Einstein field equations which contribute to
gravitational energy and that such geometric mass can be attributed to the
virial mass discrepancy in cluster of galaxies. We then derive the velocity
dispersion relation for clusters followed by the metric tensor components
inside the cluster as well as the lagrangian in terms of the
observational parameters. Since these quantities may also be obtained
experimentally, the virial theorem is a convenient tool to
test the viability of theories in different models. Finally,
we discuss the limitations of our approach in the light of the cosmological
averaging used and questions that have been raised in the literature against
such averaging procedures in the context of the present work.Comment: 16 pages, to appear in PR
Investigation of Light Scattering in Highly Reflecting Pigmented Coatings Quarterly Report, Feb. 1 - May 1, 1966
Monte Carlo method applied to pigment particle clusters, and relevance of Mie scattering function to reflected ligh
The alloy with a memory, 55-Nitinol: Its physical metallurgy, properties, and applications
A series of nickel titanium alloys (55-Nitinol), which are unique in that they possess a shape memory, are described. Components made of these materials that are altered in their shapes by deformation under proper conditions return to predetermined shapes when they are heated to the proper temperature range. The shape memory, together with the force exerted and the ability of the material to do mechanical work as it returns to its predetermined shape, suggest a wide variety of industrial applications for the alloy. Also included are discussions of the physical metallurgy and the mechanical, physical, and chemical properties of 55-Nitinol; procedures for melting and processing the material into useful shapes; and a summary of applications
Resonance energy transfer from a fluorescent dye molecule to plasmon and electron-hole excitations of a metal nanoparticle
We study the distance dependence of the rate of electronic excitation energy
transfer from a dye molecule to a metal nanoparticle. Using the spherical
jellium model, we evaluate the rates corresponding to the excitation of l = 1,
2, and 3 modes of the nanoparticle. Our calculation takes into account both the
electron-hole pair and the plasmon excitations of the nanoparticle. The rate
follows conventional R^-6 dependence at large distances while small deviations
from this behavior are observed at shorter distances. Within the framework of
the jellium model, it is not possible to attribute the experimentally observed
d^-4 dependence of the rate to energy transfer to plasmons or e-h pair
excitations.Comment: 4 figure
Investigation of light scattering in highly reflecting pigmented coatings Quarterly report, Nov. 1, 1965 - Feb. 1, 1966
Monte Carlo treatment to find light scattering parameters of metal filled, reflecting pigmented coating
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