19,146 research outputs found
Research and development in CdS photovoltaic film cells Third quarterly progress report, 1 Dec. 1962 - 28 Feb. 1963
Large cadmium sulfide thin film photovoltaic cell
Development of cadmium sulfide photovoltaic film cells Final report
Controlled carrier concentrations and improved cell conversion efficiencies in cadmium sulfide photovoltaic film cel
Astrometric orbits of SB9 stars
Hipparcos Intermediate Astrometric Data (IAD) have been used to derive
astrometric orbital elements for spectroscopic binaries from the newly released
Ninth Catalogue of Spectroscopic Binary Orbits (SB9). Among the 1374 binaries
from SB9 which have an HIP entry, 282 have detectable orbital astrometric
motion (at the 5% significance level). Among those, only 70 have astrometric
orbital elements that are reliably determined (according to specific
statistical tests discussed in the paper), and for the first time for 20
systems, representing a 10% increase relative to the 235 DMSA/O systems already
present in the Hipparcos Double and Multiple Systems Annex.
The detection of the astrometric orbital motion when the Hipparcos IAD are
supplemented by the spectroscopic orbital elements is close to 100% for
binaries with only one visible component, provided that the period is in the 50
- 1000 d range and the parallax is larger than 5 mas. This result is an
interesting testbed to guide the choice of algorithms and statistical tests to
be used in the search for astrometric binaries during the forthcoming ESA Gaia
mission.
Finally, orbital inclinations provided by the present analysis have been used
to derive several astrophysical quantities. For instance, 29 among the 70
systems with reliable astrometric orbital elements involve main sequence stars
for which the companion mass could be derived. Some interesting conclusions may
be drawn from this new set of stellar masses, like the enigmatic nature of the
companion to the Hyades F dwarf HIP 20935. This system has a mass ratio of 0.98
but the companion remains elusive.Comment: Astronomy & Astrophysics, in press (16 pages, 12 figures); also
available at http://www.astro.ulb.ac.be/Html/ps.html#Astrometr
Research and development in cds photovoltaic film cells third quarterly report, nov. 19, 1964 - feb. 19, 1965
Cadmium sulfide photovoltaic film cell
Research and development in CdS photovoltaic cells Third quarterly report, 29 Dec. 1965 - 29 Mar. 1966
Barrier formation studies of copper sulfide and cadmium sulfide in photovoltaic cell
Research and development in cds photovoltaic film cells final report
Fabrication of lightweight, flexible, high efficiency, low cost, thin film, cadmium sulfide solar cells to operate for long periods in space without appreciable degradatio
Two-sample Bayesian Nonparametric Hypothesis Testing
In this article we describe Bayesian nonparametric procedures for two-sample
hypothesis testing. Namely, given two sets of samples
\stackrel{\scriptscriptstyle{iid}}{\s
im} and \stackrel{\scriptscriptstyle{iid}}{\sim},
with unknown, we wish to
evaluate the evidence for the null hypothesis
versus the
alternative . Our
method is based upon a nonparametric P\'{o}lya tree prior centered either
subjectively or using an empirical procedure. We show that the P\'{o}lya tree
prior leads to an analytic expression for the marginal likelihood under the two
hypotheses and hence an explicit measure of the probability of the null
.Comment: Published at http://dx.doi.org/10.1214/14-BA914 in the Bayesian
Analysis (http://projecteuclid.org/euclid.ba) by the International Society of
Bayesian Analysis (http://bayesian.org/
Collective Excitations of a Two-Component Bose Condensate at Finite Temperature
We compare the collective modes for Bose-condensed systems with two
degenerate components with and without spontaneous intercomponent coherence at
finite temperature using the time-dependent Hartree-Fock approximation. We show
that the interaction between the condensate and non-condensate in these two
cases results in qualitatively different collective excitation spectra. We show
that at zero temperature the single-particle excitations of the incoherent Bose
condensate can be probed by intercomponent excitations.Comment: 4 pages, 3 figures, Submitted to PR
Spectral weight redistribution in strongly correlated bosons in optical lattices
We calculate the single-particle spectral function for the one-band
Bose-Hubbard model within the random phase approximation (RPA). In the strongly
correlated superfluid, in addition to the gapless phonon excitations, we find
extra gapped modes which become particularly relevant near the superfluid-Mott
quantum phase transition (QPT). The strength in one of the gapped modes, a
precursor of the Mott phase, grows as the QPT is approached and evolves into a
hole (particle) excitation in the Mott insulator depending on whether the
chemical potential is above (below) the tip of the lobe. The sound velocity of
the Goldstone modes remains finite when the transition is approached at a
constant density, otherwise, it vanishes at the transition. It agrees well with
Bogoliubov theory except close to the transition. We also calculate the spatial
correlations for bosons in an inhomogeneous trapping potential creating
alternating shells of Mott insulator and superfluid. Finally, we discuss the
capability of the RPA approximation to correctly account for quantum
fluctuations in the vicinity of the QPT.Comment: 14 pages, 12 figure
Cell surface localization of tissue transglutaminase is dependent on a fibronectin-binding site in its N-terminal beta-sandwich domain
Increasing evidence indicates that tissue transglutaminase (tTG) plays a role in the assembly and remodeling of extracellular matrices and promotes cell adhesion. Using an inducible system we have previously shown that tTG associates with the extracellular matrix deposited by stably transfected 3T3 fibroblasts overexpressing the enzyme. We now show by confocal microscopy that tTG colocalizes with pericellular fibronectin in these cells, and by immunogold electron microscopy that the two proteins are found in clusters at the cell surface. Expression vectors encoding the full-length tTG or a N-terminal truncated tTG lacking the proposed fibronectin-binding site (fused to the bacterial reporter enzyme β-galactosidase) were generated to characterize the role of fibronectin in sequestration of tTG in the pericellular matrix. Enzyme-linked immunosorbent assay style procedures using extracts of transiently transfected COS-7 cells and immobilized fibronectin showed that the truncation abolished fibronectin binding. Similarly, the association of tTG with the pericellular matrix of cells in suspension or with the extracellular matrix deposited by cell monolayers was prevented by the truncation. These results demonstrate that tTG binds to the pericellular fibronectin coat of cells via its N-terminal β-sandwich domain and that this interaction is crucial for cell surface association of tTG
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