Experimental validation of opto-thermo-elastic modeling in OOFELIE Multiphysics

The objective of this work is to demonstrate the correlation between a simple laboratory test bench case and the predictions of the Oofelie MultiPhysics software in order to deduce modelling guidelines and improvements. For that purpose two optical systems have been analysed. The first one is a spherical lens fixed in an aluminium barrel, which is the simplest structure found in an optomechanical system. In this study, material characteristics are assumed to be well known: BK7 and aluminium have been retained. Temperature variations between 0 and +60°C from ambient have been applied to the samples. The second system is a YAG laser bar heated by means of a dedicated oven. For the two test benches thermo-elastic distortions have been measured using a Fizeau interferometer. This sensor measures wavefront error in the range of 20 nm to 1 μm without physical contact with the optomechanical system. For the YAG bar birefringence and polarization measurements have also been performed using a polarimetric bench. The tests results have been compared to the predictions obtained by Oofelie MultiPhysics which is a multiphysics toolkit treating coupled problems of optics, mechanics, thermal physics, electricity, electromagnetism, acoustics and hydrodynamics. From this comparison modelling guidelines have been issued with the aim of improving the accuracy of computed thermo-elastic distortions and their impact on the optical performances

Evidence for weathering and volcanism during the PETM from Arctic Ocean and Peri-Tethys osmium isotope records

Sudden global warming during the Paleocene–Eocene Thermal Maximum (PETM, 55.9 Ma) occurred because of the rapid release of several thousand gigatonnes of isotopically light carbon into the oceans and atmosphere; however, the cause of this release is not well understood. Some studies have linked carbon injection to volcanic activity associated with the North Atlantic Igneous Province (NAIP), while others have emphasised carbon cycle feedbacks associated with orbital forcing. This study presents the osmium isotope compositions of mudrocks that were deposited during the PETM at four locations (one from the Arctic Ocean, and three from the Peri-Tethys). The Os-isotope records all exhibit a shift of similar magnitude towards relatively radiogenic values across the PETM. This observation confirms that there was a transient, global increase in the flux of radiogenic Os from the weathering of continental rocks in response to elevated temperatures at that time. The tectonic effects of NAIP volcanic emplacement near the onset of the PETM is recorded by anomalously radiogenic Os-isotope compositions of PETM-age Arctic Ocean samples, which indicate an interval of hydrographic restriction that can be linked tectonic uplift due to hotspot volcanism in the North Atlantic seaway. The Peri-Tethys data also document a transient, higher flux of unradiogenic osmium into the ocean near the beginning of the PETM, most likely from the weathering of young mafic rocks associated with the NAIP. These observations support the hypothesis that volcanism played a major role in triggering the cascade of environmental changes during the PETM, and highlight the influence of paleogeography on the Os isotope characteristics of marine water masses

PROLACTINE ET SYNDROME PREMENSTRUEL

The definition of the premenstrual syndrome (PMS) is still controversial and its incidence is thus diversely appreciated. Its various physical and psychic symptoms are strongly influenced by the social and cultural background. For this reason, the beneficial effect of placebo is reported to be very high, at least for a short period. In spite of attractive endocrinological arguments and of the seemingly good results obtained with bromocriptine in the treatment of premenstrual breast complaints, the role of prolactin and of its modifications in the aetiology of PMS is still hypothetical.SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

Mise en oeuvre d'une meilleure technique disponible (II)

info:eu-repo/semantics/publishe

Mise en oeuvre d'une meilleure technique disponible (I)

info:eu-repo/semantics/publishe

Le comportement suicidaire: facteurs de risque psychosociaux et psychiatriques.

peer reviewe

Recycling by electrodialysis: From lab to industrial applications

The purpose of this paper is to describe an experimental method developed to study the use of electrodialysis (ED) as a recycling process introduced within some operations in the surface treatment industry. The case study is acid picking before electroplating. The first step is the study and selection of ion-exchange membrane couples. The second step is the development of tools to promote the use of ED applied to industry. Tracer methods and surface treatment models are described.SCOPUS: ar.jinfo:eu-repo/semantics/publishe