956,600 research outputs found
Strengths of the resonances at 436, 479, 639, 661, and 1279 keV in the Ne(p,)Na reaction
The Ne(p,)Na reaction is included in the neon-sodium
cycle of hydrogen burning. A number of narrow resonances in the Gamow window
dominates the thermonuclear reaction rate. Several resonance strengths are only
poorly known. As a result, the Ne(p,)Na thermonuclear
reaction rate is the most uncertain rate of the cycle. Here, a new experimental
study of the strengths of the resonances at 436, 479, 639, 661, and 1279 keV
proton beam energy is reported. The data have been obtained using a tantalum
target implanted with Ne. The strengths of the resonances
at 436, 639, and 661 keV have been determined with a relative approach, using
the 479 and 1279 keV resonances for normalization. Subsequently, the ratio of
resonance strengths of the 479 and 1279 keV resonances was determined,
improving the precision of these two standards. The new data are consistent
with, but more precise than, the literature with the exception of the resonance
at 661 keV, which is found to be less intense by one order of magnitude. In
addition, improved branching ratios have been determined for the gamma decay of
the resonances at 436, 479, and 639 keV.Comment: Final version, now using the Kelly et al. (2015) data [15] for
normalization; 10 pages, 7 figures, 3 table
Lluís Font, Pere (2016). Cristianisme i modernitat: Per una inculturació moderna del cristianisme
Lluís Font, Pere (2016)Cristianisme i modernitat: Per una inculturació moderna del cristianismeBarcelona: Fundació Joan Maragall / Editorial Cruïlla, 347 p.ISBN 978-84-661-4028-7Lluís Font, Pere (2016)Cristianisme i modernitat: Per una inculturació moderna del cristianismeBarcelona: Fundació Joan Maragall / Editorial Cruïlla, 347 p.ISBN 978-84-661-4028-7Lluís Font, Pere (2016)Cristianisme i modernitat: Per una inculturació moderna del cristianismeBarcelona: Fundació Joan Maragall / Editorial Cruïlla, 347 p.ISBN 978-84-661-4028-
Discovery and Precise Characterization by the MEarth Project of LP 661-13, an Eclipsing Binary Consisting of Two Fully Convective Low-mass Stars
We report the detection of stellar eclipses in the LP 661-13 system. We
present the discovery and characterization of this system, including high
resolution spectroscopic radial velocities and a photometric solution spanning
two observing seasons. LP 661-13 is a low mass binary system with an orbital
period of days at a distance of parsecs. LP 661-13A is a star while LP
661-13B is a star. The radius of each component
is and ,
respectively. We detect out of eclipse modulations at a period slightly shorter
than the orbital period, implying that at least one of the components is not
rotating synchronously. We find that each component is slightly inflated
compared to stellar models, and that this cannot be reconciled through age or
metallicity effects. As a nearby eclipsing binary system where both components
are near or below the full-convection limit, LP 661-13 will be a valuable test
of models for the structure of cool dwarf stars.Comment: 24 pages, 8 tables, 6 figures. Submitted to ApJ, comments welcom
Model-based engineering of widgets, user applications and servers compliant with ARINC 661 specification
International audienceThe purpose of ARINC 661 specification [1] is to define interfaces to a Cockpit Display System (CDS) used in any types of aircraft installations. ARINC 661 provides precise information for communication protocol between application (called User Applications) and user interface components (called widgets) as well as precise information about the widgets themselves. However, in ARINC 661, no information is given about the behaviour of these widgets and about the behaviour of an application made up of a set of such widgets. This paper presents the results of the application of a formal description technique to the various elements of ARINC 661 specification within an industrial project. This formal description technique called Interactive Cooperative Objects defines in a precise and non-ambiguous way all the elements of ARINC 661 specification. The application of the formal description techniques is shown on an interactive application called MPIA (Multi Purpose Interactive Application). Within this application, we present how ICO are used for describing interactive widgets, User Applications and User Interface servers (in charge of interaction techniques). The emphasis is put on the model-based management of the feel of the applications allowing rapid prototyping of the external presentation and the interaction techniques. Lastly, we present the CASE (Computer Aided Software Engineering) tool supporting the formal description technique and its new extensions in order to deal with large scale applications as the ones targeted at by ARINC 661 specification
Near-infrared Detection of WD 0806-661 B with the Hubble Space Telescope
WD 0806-661 B is one of the coldest known brown dwarfs (T=300-345 K) based on
previous mid-infrared photometry from the Spitzer Space Telescope. In addition,
it is a benchmark for testing theoretical models of brown dwarfs because its
age and distance are well-constrained via its primary star (2+/-0.5 Gyr,
19.2+/-0.6 pc). We present the first near-infrared detection of this object,
which has been achieved through F110W imaging (~Y+J) with the Wide Field Camera
3 on board the Hubble Space Telescope. We measure a Vega magnitude of
m110=25.70+/-0.08, which implies J~25.0. When combined with the Spitzer
photometry, our estimate of J helps to better define the empirical sequence of
the coldest brown dwarfs in M4.5 versus J-[4.5]. The positions of WD 0806-661 B
and other Y dwarfs in that diagram are best matched by the cloudy models of
Burrows et al. and the cloudless models of Saumon et al., both of which employ
chemical equilibrium. The calculations by Morley et al. for 50% cloud coverage
differ only modestly from the data. Spectroscopy would enable a more stringent
test of the models, but based on our F110W measurement, such observations are
currently possible only with Hubble, and would require at least ~10 orbits to
reach a signal-to-noise ratio of ~5
Five-Qubit Contextuality, Noise-Like Distribution of Distances Between Maximal Bases and Finite Geometry
Employing five commuting sets of five-qubit observables, we propose specific
160-661 and 160-21 state proofs of the Bell-Kochen-Specker theorem that are
also proofs of Bell's theorem. A histogram of the 'Hilbert-Schmidt' distances
between the corresponding maximal bases shows in both cases a noise-like
behaviour. The five commuting sets are also ascribed a finite-geometrical
meaning in terms of the structure of symplectic polar space W(9,2).Comment: 10 pages, 2 figure
Jumping performance in the highly aquatic frog, Xenopus tropicalis : sex-specific relationships between morphology and performance
Frogs are characterized by a morphology that has been suggested to be related to their unique jumping specialization. Yet, the functional demands associated with jumping and swimming may not be that different as suggested by studies with semi-aquatic frogs. Here, we explore whether features previously identified as indicative of good burst swimming performance also predict jumping performance in a highly aquatic frog, Xenopus tropicalis. Moreover, we test whether the morphological determinants of jumping performance are similar in the two sexes and whether jumping performance differs in the two sexes. Finally we test whether jumping capacity is positively associated with burst swimming and terrestrial endurance capacity in both sexes. Our results show sex-specific differences in jumping performance when correcting for differences in body size. Moreover, the features determining jumping performance are different in the two sexes. Finally, the relationships between different performance traits are sex-dependent as well with females, but not males, showing a trade-off between peak jumping force and the time jumped to exhaustion. This suggests that different selective pressures operate on the two sexes, with females being subjected to constraints on locomotion due to their greater body mass and investment in reproductive capacity. In contrast, males appear to invest more in locomotor capacity giving them higher performance for a given body size compared to females
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