51,873 research outputs found
One- and Two-Nucleon Structure form Green's Function Theory
We review some applications of self-consistent Green's function theory to
studies of one- and two-nucleon structure in finite nuclei.
Large-scale microscopic calculations that employ realistic nuclear forces are
now possible. Effects of long-range correlations are seen to play a dominant
role in determining the quenching of absolute spectroscopic factors. They also
enhance considerably (e,e'pn) cross sections in superparallel kinematics, in
agreement with observations.Comment: Proceedings of the International Symposium on "Forefronts of
Researches in Exotic Nuclear Structures" (Niigata2010)
Role of Insects and Diseases in a Jack Pine Provenance Study
Two jack pine plantations were established at the Cloquet Forestry Center, Cloquet, Minnesota, in 1942 and 1943, using trees originating from 22 sites in the United States and 10 in Canada. From 1945 to 1953 the incidence of attack by insects and diseases was recorded individually for all trees, and in 1980-1981 the diameter and form of both living and dead trees were recorded. There were differences in the incidence of attack by the pests and in tree response to early injury among the various seed sources. In 1980 and in 1981 there were differences in tree form resulting from insect and both living and dead pest-free trees had the best form. The diameter increases from 1955 to 1980-1981 were almost identical for all categories with the exception of the dead pest-free trees which had the smallest diameters
Plasma Diagnostics by Antenna Impedance Measurements
The impedance of an electrically short antenna immersed in a plasma provides an excellent in situ diagnostic tool for electron density and other plasma parameters. By electrically short we mean that the wavelength of the free-space electromagnetic wave that would be excited at the driving frequency is much longer than the physical size of the antenna. Probes using this impedance technique have had a long history with sounding rockets and satellites, stretching back to the early 1960s. This active technique could provide information on composition and temperature of plasmas for comet or planetary missions. Advantages of the impedance probe technique are discussed and two classes of instruments built and flown by SDL-USU for determining electron density (the capacitance and plasma frequency probes) are described
Effects of Demographics and Attitudes on WTP for Fuel Import Reductions through Ethanol Purchases
imported fuel, willingness to pay, Marketing,
Static feed water electrolysis module
An advanced static feed water electrolysis module (SFWEM) and associated instrumentation for generating breathable O2 was developed. The system also generates a H2 byproduct for use in an air revitalization system for O2 recovery from metabolic CO2. Special attention was given to: (1) eliminating water feed compartment degassing, (2) eliminating need for zero gravity condenser/separators, (3) increasing current density capability, and (4) providing a self contained module so that operation is independent of laboratory instrumentation and complicated startup/shutdown procedures
Conceptual mechanization studies for a horizon definition spacecraft structures and thermal subsystem
Conceptual mechanization for horizon definition spacecraft structures and thermal subsystem - spin-stabilized, hexagonal cylinder for launch of two-stage Improved Delta /DSV-3N
Measurements and Monte-Carlo simulations of the particle self-shielding effect of B4C grains in neutron shielding concrete
A combined measurement and Monte-Carlo simulation study was carried out in
order to characterize the particle self-shielding effect of B4C grains in
neutron shielding concrete. Several batches of a specialized neutron shielding
concrete, with varying B4C grain sizes, were exposed to a 2 {\AA} neutron beam
at the R2D2 test beamline at the Institute for Energy Technology located in
Kjeller, Norway. The direct and scattered neutrons were detected with a neutron
detector placed behind the concrete blocks and the results were compared to
Geant4 simulations. The particle self-shielding effect was included in the
Geant4 simulations by calculating effective neutron cross-sections during the
Monte-Carlo simulation process. It is shown that this method well reproduces
the measured results. Our results show that shielding calculations for
low-energy neutrons using such materials would lead to an underestimate of the
shielding required for a certain design scenario if the particle self-shielding
effect is not included in the calculations.Comment: This manuscript version is made available under the CC-BY-NC-ND 4.0
license http://creativecommons.org/licenses/by-nc-nd/4.0
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