scholarly journals Li and Be Depletion in Stars with Exoplanets?

2011 ◽  
Vol 7 (S282) ◽  
pp. 466-467
Author(s):  
E. Delgado Mena ◽  
G. Israelian ◽  
J. I. González Hernández ◽  
R. Rebolo ◽  
N. C. Santos ◽  
...  

AbstractIt is well known that stars with orbiting giant planets have a higher metallic content than stars without detected planets. In addition, we have found that solar-type stars with planets present an extra Li depletion when compared with field stars. On the other hand, Be needs a greater temperature to be destroyed, so we may find such a relation in cooler stars, whose convective envelopes are deep enough to carry material to layers where Be can be burned. We present Li and Be abundances for an extensive sample of stars with and without detected planets, covering a wide range of effective temperatures (4700-6500 K) with the aim of studying possible differences between the abundances of both groups. The processes that take place in the formation of planetary systems may affect the mixing of material inside their host stars and hence the abundances of light elements.

1989 ◽  
Vol 67 (8) ◽  
pp. 1354-1358 ◽  
Author(s):  
Jacques Paquet ◽  
Paul Brassard

The behaviour of various types of polar dienes towards halogenated ortho quinones has been investigated in a number of representative cases. As compared to the commonly used para analogues, o-quinones provide a wide range of products that indicate a keener response to the nature, number, and position of substituents on both reactants. 3-Halogenated-o-naphthoquinones 1 and 2 react smoothly with a representative vinologous ketene acetal 3, vinylketene acetals 4 and 5, and a monooxygenated diene 6 to provide variously substituted phenanthrenequinones 7–11. Only monooxygenated dienes on the other hand add to o-benzoquinones 14–16 and give convenient syntheses of the corresponding o-naphthoquinones 18–20. Keywords: cycloaddition, o-naphthoquinones, phenanthrenequinones, regiospecificity.


2002 ◽  
Vol 55 (1) ◽  
pp. 1-37 ◽  
Author(s):  
Craig A. Monson

Abstract Reexamination of a wide range of documents surrounding the twenty-second, twenty-fourth, and twenty-fifth sessions of the Council of Trent reveals that delegates strived officially to say as little as possible about music: only that secular or impure elements should be eliminated and that specific issues should be settled locally, by individual bishops and provincial synods. But, beginning with Gustave Reese, several scholars have misleadingly strung together a preliminary canon, stressing textual intelligibility, which was never approved in the general congregations, and the few lines that actually supplanted it, concerned only with the elimination of lasciviousness. On the other hand, a largely unrecognized or misunderstood attack on church polyphony did occur at the less familiar twenty-fifth session, when Gabriele Paleotti may have attempted to suppress elaborate music in female monasteries. Although this attempt was rejected in the general congregations, its restrictions were subsequently revived by local authorities such as Paleotti and Carlo Borromeo in their own dioceses. In the Council's immediate aftermath, reformers such as Paleotti and Borromeo once again focused on the issue of intelligibility, affording it a quasi-official status that seems to have quickly become widely accepted as “iuxta formam concilii.”


Author(s):  
Shweta Singh ◽  
Sureshbabu Popuri ◽  
Qazi Mohammad Junaid ◽  
Sabiah Shahul Hameed ◽  
Jeyakumar Kandasamy

A wide range of N-tosyl α–ketoamides underwent transamidation with various alkyl amines in the absence of catalyst, base, or additives. On the other hand, transamidation in N-Boc α–ketoamides is achieved...


2018 ◽  
Vol 612 ◽  
pp. A108 ◽  
Author(s):  
A.-M. Lagrange ◽  
M. Keppler ◽  
N. Meunier ◽  
J. Lannier ◽  
H. Beust ◽  
...  

Context. The search for extrasolar planets has been limited so far to close orbit (typ. ≤5 au) planets around mature solar-type stars on the one hand, and to planets on wide orbits (≥10 au) around young stars on the other hand. To get a better view of the full giant planet population, we have started a survey to search for giant planets around a sample of carefully selected young stars. Aims. This paper aims at exploring the giant planet population around one of our targets, β Pictoris, over a wide range of separations. With a disk and a planet already known, the β Pictoris system is indeed a very precious system for studies of planetary formation and evolution, as well as of planet–disk interactions. Methods. We analyse more than 2000 HARPS high-resolution spectra taken over 13 years as well as NaCo images recorded between 2003 and 2016. We combine these data to compute the detection probabilities of planets throughout the disk, from a fraction of au to a few dozen au. Results. We exclude the presence of planets more massive than 3 MJup closer than 1 au and further than 10 au, with a 90% probability. 15+ MJup companions are excluded throughout the disk except between 3 and 5 au with a 90% probability. In this region, we exclude companions with masses larger than 18 (resp. 30) MJup with probabilities of 60 (resp. 90) %.


2019 ◽  
Vol 17 (1) ◽  
pp. 183-194
Author(s):  
Anna Rogacka-Łukasik

ADR (Alternative Dispute Resolution), as a non-judicial resolution of disputes, is a wide range of mechanisms that aim to put an end to a conflict without the need of conducting a trial before the court. On the other hand, the modern form of ADR is ODR (Online Dispute Resolution) – an online dispute resolution system that is the expression of the newest means of communication and technical innovations in order to help in non-judicial dispute resolving. The goal of this publication is to present the ODR platform and, in particular, to describe the process of filing a complaint by the consumer by means of it.


1989 ◽  
Vol 114 ◽  
pp. 144-148
Author(s):  
E. Poulin ◽  
F. Wesemael ◽  
J.B. Holberg ◽  
G. Fontaine

While the observed number of hot, helium-rich degenerates is noticeably larger than that of their hydrogen-rich counterparts, the calibration of their effective temperatures has been comparatively much less trustworthy. The spectroscopic classification scheme introduced three years ago by Wesemael, Green, and Liebert (1985, hereafter WGL), and the crude temperature domains associated with each class remain, to this date, the only comprehensive effort at defining a temperature scale for DO stars. The current uncertainty in this is perhaps best epitomized by two objects, HD149499B and PG1034+001. The former belongs to a binary system which also contains a KO V primary, 2” away. The temperature determined for the degenerate secondary ranges from 85,000±15,000 K (Wray, Parsons, and Henize 1979) to 55,000±5000 K (Sion, Guinan, and Wesemael 1982, hereafter SGW). PG1034+001, on the other hand, is the prototype of the so-called hot DO spectroscopic class; WGL assign an uncertain temperature of 80,000±20,000 K to this object.


2012 ◽  
Vol 8 (S293) ◽  
pp. 152-158 ◽  
Author(s):  
Rudolf Dvorak ◽  
Li-Yong Zhou ◽  
Helmut Baudisch

AbstractWe take as dynamical model for extrasolar planetary systems a central star like our Sun and two giant planets m1 and m2 like Jupiter and Saturn. We change the mass ratio μ=m2/m1 of the two large planets for a wide range of 1/16 < μ < 16. We also change the ratio between the initial semi-major axes (ν=a2/a1) in the range of 1.2 < ν < 3 to model the different architecture of extrasolar planetary systems hosting two giant planets. The results for possible Trojans (Trojan planets) in the equilateral equilibrium points of the inner planet m1 and the outer planet m2 were derived with the aid of numerical integration. It turned out that in many configurations – depending on the mass ratios μ and the semi-major axes ratio ν – giant planets may host Trojans.


Author(s):  
Karin de Boer

This chapter examines Hegel’s lectures on the history of modern philosophy in view of the tension between, on the one hand, his ambition to grasp philosophy’s past in a truly philosophical way and, on the other hand, the necessity to account for the actual particularities of a wide range of philosophical systems. Hegel’s lectures are put in relief by comparing their methodological principles to those put forward by his Kantian predecessor Tennemann. After discussing Hegel’s conception of modern philosophy as a whole, the chapter turns to his reading of Locke, Leibniz, and, in particular, Kant. In this context, it also compares Hegel’s assessment of Kant’s achievements to that of Tennemann. The chapter concludes by considering Hegel’s account of the final moment of the history of philosophy.


2003 ◽  
Vol 208 ◽  
pp. 25-35 ◽  
Author(s):  
Shigeru Ida ◽  
Eiichiro Kokubo ◽  
Junko Kominami

Accretion from many small planetesimals to planets is reviewed. Solid protoplanets accrete through runaway and oligarchic growth until they become isolated. The isolation mass of protoplanets in terrestrial planet region is about 0.1-0.2 Earth mass, which suggests giant impacts among the protoplanets in the final stage of terrestrial planet formation. On the other hand, the isolation mass in Jupiter's and Saturn's orbits is about a few to 5 Earth masses, which may be massive enough to trigger gas accretion onto the cores. The isolation mass in Uranus and Neptune's orbits is as large as their present cores. Extending the above arguments to extrasolar planetary systems that are formed from disks with various initial masses, we also discuss diversity of extrasolar planetary systems.


Africa ◽  
1966 ◽  
Vol 36 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Kenneth Little

Opening ParagraphIn the concluding paragraphs of Part I of this article it was pointed out that in addition to its judicial functions the Poro society possessed some important powers of administration. On the other hand, there was also evidence to suggest that the society carried on this wide range of activities, amounting almost to government of the country, as an instrument of the chiefs.


Sign in / Sign up

Export Citation Format

Share Document