1,171 research outputs found
Utilizing ERTS imagery to detect plant diseases and nutrient deficiencies, soil types and soil moisture levels
The author has identified the following significant results. ERTS-1 imagery may be used to delineate soil associations. It does have the capacity to divide soils into groups such that their land use and management would be similar. It offers definite potential for making grass flood-plain, wetland, river shoreline, and land use change surveys. Production of volume strata and forest type from the two usable bands of ERTS-1 imagery were of questionable value. No imagery was received for evaluation during the time of year when maine dwarf mosaic virus and southern corn leaf blight were active
Utilizing ERTS imagery to detect plant diseases and nutrient deficiencies, soil types and soil moisture levels
There are no author-identified significant results in this report
Spin susceptibility and fluctuation corrections in the BCS-BEC crossover regime of an ultracold Fermi gas
We investigate magnetic properties and effects of pairing fluctuations in the
BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover
regime of an ultracold Fermi gas. Recently, Liu and Hu, and Parish, pointed out
that the strong-coupling theory developed by Nozi\`eres and Schmitt-Rink (NSR),
which has been extensively used to successfully clarify various physical
properties of cold Fermi gases, unphysically gives negative spin susceptibility
in the BCS-BEC crossover region. The same problem is found to also exist in the
ordinary non-self-consistent T-matrix approximation. In this paper, we clarify
that this serious problem comes from incomplete treatment in term of pseudogap
phenomena originating from strong pairing fluctuations, as well as effects of
spin fluctuations on the spin susceptibility. Including these two key issues,
we construct an extended T-matrix theory which can overcome this problem. The
resulting positive spin susceptibility agrees well with the recent experiment
on a 6Li Fermi gas done by Sanner and co-workers. We also apply our theory to a
polarized Fermi gas to examine the superfluid phase transition temperature Tc,
as a function of the polarization rate. Since the spin susceptibility is an
important physical quantity, especially in singlet Fermi superfluids, our
results would be useful in considering how singlet pairs appear above and below
Tc in the BCS-BEC crossover regime of cold Fermi gases.Comment: 21 pages, 9 figure
A microscopic model for Josephson currents
A microscopic model of a Josephson junction between two superconducting
plates is proposed and analysed. For this model, the nonequilibrium steady
state of the total system is explicitly constructed and its properties are
analysed. In particular, the Josephson current is rigorously computed as a
function of the phase difference of the two plates and the typical properties
of the Josephson current are recovered
A Bisognano-Wichmann-like Theorem in a Certain Case of a Non Bifurcate Event Horizon related to an Extreme Reissner-Nordstr\"om Black Hole
Thermal Wightman functions of a massless scalar field are studied within the
framework of a ``near horizon'' static background model of an extremal R-N
black hole. This model is built up by using global Carter-like coordinates over
an infinite set of Bertotti-Robinson submanifolds glued together. The
analytical extendibility beyond the horizon is imposed as constraints on
(thermal) Wightman's functions defined on a Bertotti-Robinson sub manifold. It
turns out that only the Bertotti-Robinson vacuum state, i.e. , satisfies
the above requirement. Furthermore the extension of this state onto the whole
manifold is proved to coincide exactly with the vacuum state in the global
Carter-like coordinates. Hence a theorem similar to Bisognano-Wichmann theorem
for the Minkowski space-time in terms of Wightman functions holds with
vanishing ``Unruh-Rindler temperature''. Furtermore, the Carter-like vacuum
restricted to a Bertotti-Robinson region, resulting a pure state there, has
vanishing entropy despite of the presence of event horizons. Some comments on
the real extreme R-N black hole are given
Experiments on a videotape atom chip: fragmentation and transport studies
This paper reports on experiments with ultra-cold rubidium atoms confined in
microscopic magnetic traps created using a piece of periodically-magnetized
videotape mounted on an atom chip. The roughness of the confining potential is
studied with atomic clouds at temperatures of a few microKelvin and at
distances between 30 and 80 microns from the videotape-chip surface. The
inhomogeneities in the magnetic field created by the magnetized videotape close
to the central region of the chip are characterized in this way. In addition,
we demonstrate a novel transport mechanism whereby we convey cold atoms
confined in arrays of videotape magnetic micro-traps over distances as large as
~ 1 cm parallel to the chip surface. This conveying mechanism enables us to
survey the surface of the chip and observe potential-roughness effects across
different regions.Comment: 29 pages, 22 figures
Unique aliphatic amidase from a psychrotrophic and haloalkaliphilic nesterenkonia isolate
Nesterenkonia strain AN1 was isolated from a screening program for nitrile- and amide-hydrolyzing microorganisms in Antarctic desert soil samples. Strain AN1 showed significant 16S rRNA sequence identity to known members of the genus. Like known Nesterenkonia species, strain AN1 was obligately alkaliphilic (optimum environmental pH, 9 to 10) and halotolerant (optimum environmental Na+ content, 0 to 15% [wt/vol]) but was also shown to be an obligate psychrophile with optimum growth at approximately 21°C
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