The variation of tidal dissipation in the convective envelope of low-mass stars along their evolution

Since 1995, more than 1500 exoplanets have been discovered around a large diversity of host stars (from M- to A-type stars). Tidal dissipation in stellar convective envelopes is a key actor that shapes the orbital architecture of short-period systems. Our objective is to understand and evaluate how tidal dissipation in the convective envelope of low-mass stars (from M to F types) depends on their mass, evolutionary stage and rotation. Using a simplified two-layer assumption, we compute analytically the frequency-averaged tidal dissipation in their convective envelope. This dissipation is due to the conversion into heat of the kinetic energy of tidal non wave-like/equilibrium flow and inertial waves because of the viscous friction applied by turbulent convection. Using grids of stellar models allows us to study the variation of the dissipation as a function of stellar mass and age on the Pre-Main-Sequence and on the Main-Sequence for stars with masses spanning from $0.4$ to $1.4M_{\odot}$. As shown by observations, tidal dissipation in stars varies over several orders of magnitude as a function of stellar mass, age and rotation. During their Pre-Main-Sequence, all low-mass stars have an increase of the frequency-averaged tidal dissipation for a fixed angular velocity in their convective envelope until they reach a critical aspect and mass ratios. Next, the dissipation evolves on the Main Sequence to an asymptotic value that becomes maximum for $0.6M_{\odot}$ K-type stars and that decreases by several orders of magnitude with increasing stellar mass. Finally, the rotational evolution of low-mass stars strengthens the importance of tidal dissipation during the Pre-Main-Sequence for star-planet and multiple star systems.Comment: 5 pages, 4 figures, accepted for publication as a Letter in Astronomy & Astrophysic

Study of the dEE/dxx resolution of a GEM Readout Chamber prototype for the upgrade of the ALICE TPC

The ALICE Collaboration is planning a major upgrade of its central barrel detectors to be able to cope with the increased LHC luminosity beyond 2020. For the TPC, this implies a replacement of the currently used gated MWPCs (Multi-Wire Proportional Chamber) by GEM (Gas Electron Multiplier) based readout chambers. In order to prove, that the present particle identification capabilities via measurement of the specific energy loss are retained after the upgrade, a prototype of the ALICE IROC (Inner Readout Chamber) has been evaluated in a test beam campaign at the CERN PS. The d$E$/d$x$ resolution of the prototype has been proven to be fully compatible with the current MWPCs.Comment: 4 pages, 5 figures, Proceedings of "4th Conference on Micro-Pattern Gaseous Detectors

Corporate social responsibility in the UK, the Netherlands and Germany: theory and forerunners

The results in this paper should help connect theoretical concepts with CSR practices in the current business world. This paper will present the findings of a survey sent to businesses in the UK, the Netherlands, and Germany. The empirical data indicate some interesting tendencies. CSR as perceived within the business community is strongly related to environmental management and has a longer history than might have been expected. External factors, such as legal requirements, general external pressure (NGOs, globalization), and media coverage and campaigning have triggered changes in the business world in favor of CSR, but when CSR policies and schemes are initially under discussion, internal forces, such as the board of directors and the middle management, take over and lead the process. Furthermore, the results of the questionnaire show that external forces, such as government, NGOs, and communities, are not relevant with respect to driving CSR development forward

New Horizons in Psychiatry

Psychiatrists have long held that there should be more psychiatry in general medicine, and the nonpsychiatric physicians have said that there should be much more medicine in psychiatry. Both groups have been perfectly correct and are being told by the consuming population that there must be more sociology in each of them. The future psychiatrist must and will work with his colleagues in medicine, not to achieve a utopia, but at least to approach this desirable situation in some degree

The New England Narrative

Though equally successful, noteworthy, inspiring, and crucial as the contributions to American Independence made by New England women patriots, the contributions made by North Carolinian women patriots are excluded from the history of America’s founding as a direct result of sectional nationalism