5,764 research outputs found
Silicon solar cell development for low temperature and low illumination intensity operation, volume 1 Analysis report, 30 Jun. 1969 - 30 Apr. 1970
Operational performance of solar cell at low temperatures and under low illumination intensit
Probabilistic Linear Solvers: A Unifying View
Several recent works have developed a new, probabilistic interpretation for
numerical algorithms solving linear systems in which the solution is inferred
in a Bayesian framework, either directly or by inferring the unknown action of
the matrix inverse. These approaches have typically focused on replicating the
behavior of the conjugate gradient method as a prototypical iterative method.
In this work surprisingly general conditions for equivalence of these disparate
methods are presented. We also describe connections between probabilistic
linear solvers and projection methods for linear systems, providing a
probabilistic interpretation of a far more general class of iterative methods.
In particular, this provides such an interpretation of the generalised minimum
residual method. A probabilistic view of preconditioning is also introduced.
These developments unify the literature on probabilistic linear solvers, and
provide foundational connections to the literature on iterative solvers for
linear systems
Solar cell cover glass development Final report
High vacuum ion beam sputtering of integral coverslips for solar cell utilizatio
Low cost silicon solar cell array
The technological options available for producing low cost silicon solar cell arrays were examined. A project value of approximately 2/watt is projected, based on mass production capacity demand. Recommendations are included for the most promising cost reduction options
The (gamma^*-q\bar q)-Reggeon Vertex in Next-to-Leading Order QCD
As a first step towards the computation of the NLO corrections to the photon
impact factor in the scattering
process, we calculate the one loop corrections to the coupling of the reggeized
gluon to the vertex. We list the results for the Feynman
diagrams which contribute: all loop integrations are carried out, and the
results are presented in the helicity basis of photon, quark, and antiquark.Comment: 26 pages LaTeX, 3 figures, typos fixe
Identification of further Craterostigma plantagineum cdt mutants affected in abscisic acid mediated desiccation tolerance
The resurrection plant (Craterostigma plantagineum) is desiccation tolerant. However, callus derived from this plant, when propagated in vitro, requires exogenously applied abscisic acid (ABA) in order to survive desiccation. Treatment of callus tissue with ABA induces most of the genes that are induced by dehydration in the whole plant. This property has been exploited for the isolation of mutants that show dominant phenotypes resulting from the ectopic expression of endogenous genes induced by the insertion of a foreign promoter. Here we describe new T-DNA tagged Craterostigma desiccation-tolerant (cdt) mutants with different molecular and physiological characteristics, suggesting that different pathways of desiccation tolerance are affected. One of the mutants, cdt-2, constitutively expresses known osmoprotective Lea genes in callus and leaf tissue. Further analysis of this mutant revealed that the tagged locus is similar to a previously characterised gene, CDT-1, which codes for a signalling molecule that confers desiccation tolerance. The nature of the T-DNA insertion provides insight into the mechanism by which the CDT-1/2 gene family functions in ABA signal transduction
Heritability of daytime cortisol levels in children
INTRODUCTION Cortisol is a steroid hormone secreted by the outer cortex of the adrenal gland. Its secretion is stimulated by ACTH (adrenocorticotrophic hormone), produced in the pituitary in response to corticotropin-releasing hormone (CRH), a product from neurons in the paraventricular nucleus of the hypothalamus.After its release, the major part of cortisol binds to the plasma proteins corticosteroid binding globulin (CBG, or transcortin) and albumin, which prevents the hormone from penetrating the membranes of their target cells. About 3--5% of the total cortisol is the unbound, biologically active fraction. This active fraction has permissive, suppressive, stimulatory, and preparative action effects in the realms of cardiovascular function, fluid volume and hemorrhage, immunity and inflammation, metabolism, neurobiology, and reproductive physiology (Sapolsky, Romero, and Munck, 2000). Although cortisol is mainly known for its pivotal role in generating an adequate response to phy
Velocity-selective direct frequency-comb spectroscopy of atomic vapors
We present an experimental and theoretical investigation of two-photon direct
frequency-comb spectroscopy performed through velocity-selective excitation. In
particular, we explore the effect of repetition rate on the
two-photon transitions
excited in a rubidium atomic vapor cell. The transitions occur via step-wise
excitation through the states by use of the direct
output of an optical frequency comb. Experiments were performed with two
different frequency combs, one with a repetition rate of MHz and
one with a repetition rate of MHz. The experimental spectra are
compared to each other and to a theoretical model.Comment: 10 pages, 7 figure
Surgery groups of the fundamental groups of hyperplane arrangement complements
Using a recent result of Bartels and Lueck (arXiv:0901.0442) we deduce that
the Farrell-Jones Fibered Isomorphism conjecture in L-theory is true for any
group which contains a finite index strongly poly-free normal subgroup, in
particular, for the Artin full braid groups. As a consequence we explicitly
compute the surgery groups of the Artin pure braid groups. This is obtained as
a corollary to a computation of the surgery groups of a more general class of
groups, namely for the fundamental group of the complement of any fiber-type
hyperplane arrangement in the complex n-space.Comment: 11 pages, AMSLATEX file, revised following referee's comments and
suggestions, to appear in Archiv der Mathemati
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