Recent developments in modeling of the stress derivative of magnetization in ferromagnetic materials

The effect of changing stress on the magnetization of ferromagnetic materials leads to behavior in which the magnetization may increase, or decrease, when exposed to the same stress under the same external conditions. A simple empirical law seems to govern the behavior when the magnetization begins from a major hysteresis loop. The application of the law of approach, in which the derivative of the magnetization with respect to the elastic energy supplied dM/dW is proportional to the magnetization displacement M an−M, is discussed

New young planetary nebulae in IPHAS

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory. DOI: 10.1051/0004-6361/200811575Aims. We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. The IPHAS catalogue of H-emitting stars provides a useful basis for this study since all sources present in this catalogue must be of small angular diameter. Methods. The PN candidates are selected based on their location in two colour-colour diagrams: IPHAS (r' - H) vs. (r' - i'), and 2MASS (J - H) vs. (H - ). Spectroscopic follow-up was carried out on a sample of candidates to confirm their nature. Results. We present a total of 83 PN candidates. We were able to obtain spectra or find the classification from the literature for 35 candidates. Five of these objects are likely to be new PNe, including one large bipolar PN discovered serendipitously close to an emission-line star. PN distances deduced from extinction-distance relations based on IPHAS field-star photometry are presented for the first time. These yield distance estimates for our objects in the range 2 kpc and 6 kpc. From the data in hand, we conclude that four of the discovered objects are probably young PNe.Peer reviewe

Contributions au colloque La conciliation dans le ressort de la cour d'appel de Toulouse, Acte 2

Ce document contient une partie des contributions au colloque "La conciliation dans le ressort de la cour d'appel de Toulouse, Acte 2" organisé par la cour d'appel de Toulouse et l'Institut de Droit Privé de l'Université Toulouse 1 Capitole : - Plaquette de présentation du colloque - Propos introductifs de M. Defix - Table ronde "la tentative de conciliation obligatoire préalable à la saisine du juge", interventions de Mme Leclercq et Mr Brugel - Table ronde "la tentative de conciliation obligatoire devant le juge", interventions de Mme Bruggeman et Me Capéla - Table ronde "la conciliation devant le conseil de prud'hommes", interventions de Mme Dupouey-Dehan et Mr Made

Contributions au colloque La conciliation dans le ressort de la cour d'appel de Toulouse, Acte 2

Ce document contient une partie des contributions au colloque "La conciliation dans le ressort de la cour d'appel de Toulouse, Acte 2" organisé par la cour d'appel de Toulouse et l'Institut de Droit Privé de l'Université Toulouse 1 Capitole : - Plaquette de présentation du colloque - Propos introductifs de M. Defix - Table ronde "la tentative de conciliation obligatoire préalable à la saisine du juge", interventions de Mme Leclercq et Mr Brugel - Table ronde "la tentative de conciliation obligatoire devant le juge", interventions de Mme Bruggeman et Me Capéla - Table ronde "la conciliation devant le conseil de prud'hommes", interventions de Mme Dupouey-Dehan et Mr Made

Recipes for stellar jets: results of combined optical/infrared diagnostics

We examine the conditions of the plasma along a sample of 'classical' Herbig-Haro jets located in the Orion and Vela star forming regions, through combined optical-infrared spectral diagnostics. Our sample includes HH 111, HH 34, HH 83, HH 73, HH 24 C/E, HH 24 J, observed at moderate spatial/spectral resolution. The obtained spectra cover a wide wavelength range from 0.6-2.5 um, including many transitions from regions of different excitation conditions. This allows us to probe the density and temperature stratification which characterises the cooling zones behind the shock fronts along the jet. The derived physical parameters (such as the extinction, the electron density and temperature, the ionisation fraction, and the total density) are used to estimate the depletion onto dust grains of Calcium and Iron with respect to solar abundances. This turns out to be between 70% and 0% for Ca and ~90% for Fe, suggesting that the weak shocks present in the beams are not capable of completely destroying the dust grains. We then derive the mass flux rates (Mdot_jet is on average 5 10^-8 M_solar yr^-1) and the associated linear momentum fluxes. The latter are higher than, or of the same order as, those measured in the coaxial molecular flows, suggesting that the flows are jet driven. Finally, we discuss differences between jets in our sample.Comment: 19 pages, 15 figures, accepted by A&

Interprétation des effets irréversibles des contraintes au moyen d'un modèle d'hystérésis dans l'espace

A three-dimensional model of magnetic hysteresis, due to L. Néel, together with the notion of a fictitious magnetic field equivalent to a strain (W. F. Brown) gives a satisfactory interpretation of the action of mechanical strains on the magnetisation. This model is used to calculate, in the Rayleigh region, the effects produced by the application of, and by the suppression of, magnetic fields and strains.Un modèle tridimensionnel de l'hystérésis magnétique, dû à L. Néel, associé à la notion de champ fictif équivalent à une contrainte (W. F. Brown), permet d'interpréter de façon satisfaisante l'action des tensions mécaniques sur l'aimantation. Ce modèle est utilisé pour calculer, dans le domaine de Rayleigh, les effets consécutifs à l'application et à la suppression de champs et de contraintes