3,188 research outputs found
Moonlab - Preliminary design of a manned lunar laboratory A Stanford/Ames summer faculty workshop study, 24 Jun. - 6 Sep. 1968
Detailed preliminary design study of semipermanent manned lunar laboratory Moonla
Photonic excess noise and wave localization
This is a theory for the effect of localization on the super-Poissonian noise
of radiation propagating through an absorbing disordered waveguide.
Localization suppresses both the mean photon current I and the noise power P,
but the Fano factor P/I is found to remain unaffected. For strong absorption
the Fano factor has the universal value 1+3f/2 (with f the Bose-Einstein
function), regardless of whether the waveguide is long or short compared to the
localization length.Comment: 3 pages including 3 figure
Nitrous oxide emissions from the Arabian Sea: A synthesis
We computed high-resolution (1º latitude x 1º longitude) seasonal and annual nitrous oxide (N2O) concentration fields for the Arabian Sea surface layer using a database containing more than 2400 values measured between December 1977 and July 1997. N2O concentrations are highest during the southwest (SW) monsoon along the southern Indian continental shelf. Annual emissions range from 0.33 to 0.70 Tg N2O and are dominated by fluxes from coastal regions during the SW and northeast monsoons. Our revised estimate for the annual N2O flux from the Arabian Sea is much more tightly constrained than the previous consensus derived using averaged in-situ data from a smaller number of studies. However, the tendency to focus on measurements in locally restricted features in combination with insufficient seasonal data coverage leads to considerable uncertainties of the concentration fields and thus in the flux estimates, especially in the coastal zones of the northern and eastern Arabian Sea. The overall mean relative error of the annual N2O emissions from the Arabian Sea was estimated to be at least 65%
A new microscopic nucleon-nucleon interaction derived from relativistic mean field theory
A new microscopic nucleon-nucleon (NN) interaction has been derived for the
first time from the popular relativistic mean field theory (RMFT) Lagrangian.
The NN interaction so obtained remarkably relate to the inbuilt fundamental
parameters of RMFT. Furthermore, by folding it with the RMFT-densities of
cluster and daughter nuclei to obtain the optical potential, it's application
is also examined to study the exotic cluster radioactive decays, and results
obtained found comparable with the successfully used M3Y phenomenological
effective NN interactions. The presently derived NN-interaction can also be
used to calculate a number of other nuclear observables.Comment: 4 Pages 2 Figure
Structure effects in the region of superheavy elements via the -decay chain of 118
The -decay chain of 118, first proposed in the Berkeley cold
fusion experiment Pb(Kr,1n) and now retracted, is calculated by
using the preformed cluster model (PCM) of one of us (RKG). Also, the possible
branchings of -particles to heavier cluster decays of all the parents
in this chain are calculated for the first time. The calculated Q-values,
penetrabilities and preformation factors for -decays suggest that the
114 nucleus with Z=114, N=171 is a magic nucleus, either due to the
magicity of Z=114, or of N=172 or of both. The N=172 is proposed to be a magic
number in certain relativistic mean-field calculations, but with Z=120. The
calculated cluster decays point to new interesting possibilities of C
decay of the 112 parent, giving rise to a (reasonably) deformed Z=106,
N=161, 106 daughter (N=162 being now established as the deformed magic
shell) or to a doubly magic Ca cluster emitted from any of the parent
nucleus in the -decay chain. Apparently, these are exciting new
directions for future experiments
Propagation of squeezed radiation through amplifying or absorbing random media
We analyse how nonclassical features of squeezed radiation (in particular the
sub-Poissonian noise) are degraded when it is transmitted through an amplifying
or absorbing medium with randomly located scattering centra. Both the cases of
direct photodetection and of homodyne detection are considered. Explicit
results are obtained for the dependence of the Fano factor (the ratio of the
noise power and the mean current) on the degree of squeezing of the incident
state, on the length and the mean free path of the medium, the temperature, and
on the absorption or amplification rate.Comment: 8 pages, 4 figure
Nitrous oxide emissions from the Arabian Sea: A synthesis
We computed high-resolution (1º latitude x 1º longitude) seasonal and annual nitrous oxide (N<sub>2</sub>O) concentration fields for the Arabian Sea surface layer using a database containing more than 2400 values measured between December 1977 and July 1997. N<sub>2</sub>O concentrations are highest during the southwest (SW) monsoon along the southern Indian continental shelf. Annual emissions range from 0.33 to 0.70 Tg N<sub>2</sub>O and are dominated by fluxes from coastal regions during the SW and northeast monsoons. Our revised estimate for the annual N<sub>2</sub>O flux from the Arabian Sea is much more tightly constrained than the previous consensus derived using averaged in-situ data from a smaller number of studies. However, the tendency to focus on measurements in locally restricted features in combination with insufficient seasonal data coverage leads to considerable uncertainties of the concentration fields and thus in the flux estimates, especially in the coastal zones of the northern and eastern Arabian Sea. The overall mean relative error of the annual N<sub>2</sub>O emissions from the Arabian Sea was estimated to be at least 65%
Ground state properties and bubble structure of superheavy nuclei
We calculate the ground state properties of recently synthesized superheavy
nuclei starting from =105-120. The nonrelativistic and relativistic mean
field formalisms is used to evaluate the binding energy, charge radius,
quadrupole deformation parameter and the density distribution of nucleons. We
analyzed the stability of the nuclei based on the binding energy and neutron to
proton ratio. We also studied the bubble structure of the nucleus which reveals
about the special features of the superheavy nucleus
Theory for the photon statistics of random lasers
A theory for the photon statistics of a random laser is presented. Noise is
described by Langevin operators, where both fluctuations of the electromagnetic
field and of the medium are included. The theory is valid for all lasers with
small outcoupling when the laser cavity is large compared to the wavelength of
the radiation. The theory is applied to a chaotic laser cavity with a small
opening. It is known that a large number of modes can be above threshold
simultaneously in such a cavity. It is shown the amount of fluctuations is
increased compared to the Poissonian value by an amount that depends on that
number
SU(N)-symmetric quasi-probability distribution functions
We present a set of N-dimensional functions, based on generalized
SU(N)-symmetric coherent states, that represent finite-dimensional Wigner
functions, Q-functions, and P-functions. We then show the fundamental
properties of these functions and discuss their usefulness for analyzing
N-dimensional pure and mixed quantum states.Comment: 16 pages, 2 figures. Updated text to reflect referee comment
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