Helium and neon isotopes in São Miguel island basalts, Azores Archipelago: New constraints on the “low 3He” hotspot origin

Lavas from the São Miguel Island, Azores Archipelago, have peculiar isotopic compositions, including radiogenic lead and strontium and un-radiogenic neodymium. The peculiar isotopic trend of São Miguel is evident in the lead-lead diagram where both 207Pb/204Pb and 208Pb/204Pb ratios are high for a given 206Pb/204Pb ratio compared to other oceanic island basalts. This signature is unique among OIBs and is particularly evident in the Nordeste area, the oldest part of São Miguel island (≥1 Ma). Only a few olivine samples from the Nordeste volcanic complex have been analyzed for helium. They show radiogenic helium signatures with 4He/3He up to 174,000 (R/Ra ~4) [Moreira et al., Helium and lead isotope geochemistry in the Azores archipelago, Earth Planet. Sci. Lett. 169: 189–205, 1999]. However, because the Nordeste volcano has an age between 1 and 4 Ma and because these samples have low helium concentrations, these radiogenic helium isotopic ratios must be considered with caution as they can also reflect post eruptive radiogenic production. In this paper we present a detailed study of the helium and neon isotopic ratios obtained from 17 Nordeste samples in order to better constrain the helium isotopic signature of the São Miguel mantle source. By coupling helium and the other isotopic systems, we propose that the São Miguel source contains non-degassed material, enriched in U and Th, that was stored in the mantle for the last ~3 Ga. As suggested by Elliot et al. [Elliott et al., The origin of enriched mantle beneath São Miguel, Azores, Geochim. Cosmochim. Acta 71: 219–240, 2007], underplated magma intruded into oceanic lithosphere and subducted ~3 Ga ago is a possible explanation for the peculiar São Miguel source isotopic signatures

Are women the superheroes of the corporate world?

Are women the superheroes of the corporate world? The increasing number of women directors coupled with the various policies and quotas in favor of boards’ gender diversity have given rise to extensive research on women directorship. This study investigates the impact of boards’ gender diversity on firm performance and firm risk. Relying on 136 FTSE100 companies and 11 years of data, this study finds evidence that gender diversity enhances corporate outcomes. Gender diversity within the executive directors’ team is associated with an increase in corporate performance and a decrease in corporate risk. However, no impact had been identified regarding gender diversity within the non-executive board of directors. The results convey the benefits of women participation in the executive suite and demonstrate the positive impact of boards’ gender diversity on corporate outcomes. As such, this study highlights women leadership potential that is being hindered by gender stereotypes.As mulheres serão os superherois do mundo corporativo? O numero crescente de mulheres em cargos diretivos, e o aumento de politicas e cotas a favor da diversificação do genero no board of directors tem levado ao aumento de estudos sobre a liderança das mulheres. Este estudo investiga o impacto que a diversidade do genero tem na performance da empresa como no risco da mesma. Tendo por base 136 FTSE 100 empresas e 11 anos de dados, este estudo encontra evidencia de que a diversidade do genero melhore os resultados da empresa. A diversidade de genero dentro de directores executivos está associada com um aumento da performance da empresa e uma diminuição no risco da mesma. Contudo nenhum impacto tem sido notado em cargos não executivos. Os resultados demonstram os beneficios da participação de mulheres em cargos executivos e demonstra o impacto positivo que a inserção de mulheres tem no board of directors. Desta forma este estudo evidencia o potencial da liderança de mulheres e por outro lado o esterótipo de generos que afecta esta área

Le travail des sapeurs-pompiers dans la crise : le cas de l'explosion " AZF "

Cet article présente le déroulement les activités de secours effectuées par les sapeurs-pompiers à l'occasion de la catastrophe d'AZF. Partant d'une méthodologie sociologique qui met au centre l'action des hommes et des femmes pour gérer les effets de la crise, nous avons décrit les principales actions de secours. Nous avons choisi de problématiser nos descriptions en inscrivant le travail analysé dans des phases successives : l'alerte, l'organisation d'urgence, le sauvetage, la finalisation et la sécurisation. Cette structuration temporelle des actions professionnelles permet d'une part de décomposer et d'identifier chronologiquement des groupe d'activités obéissant à une finalité commune; elle permet d'autre part d'identifier des problèmes opérationnels que la finalité principale (la gestion des conséquences de la catastrophe) relègue au deuxième rang

Mapping Bateson's Epistemology to Boolean Dynamic System: 1. The Emergence of Dynamic Form & 2. Hierarchies Form.

LectureGregory Bateson (e.g., 2002, p. 85ff; 2000, p. 457-460) construed knowledge to be the propogation of "difference" in a complex network, noting (2000 p. 460) that "the transform of difference travelling in a circuit is an elementary idea." The idea of difference is coded as 0 and 1 in Boolean systems. Kauffman (1993) developed NK Boolean computer simulations as a way explore how the structure of genomes might self-organize into emergent form (see Kauffman, 1995, p. 76 for a simple, concrete example). The N in NK Boolean systems refers to the number (N) of abstract entities called Nodes; in Kauffman's simulations N was very large, as high as 100,000 (1995, p. 83). The K refers to the number of inputs (from other nodes in the network) that each node has. Kauffman states that "While this is surely an idealization, we can extend it to networks of genes and their productrs interacting with one another in enormous webs of regulatory circuitry," (1995, p. 99). This reasoning parallels Bateson's idea of mental process. Indeed Bateson includes genetic activity as a part of mental process, stating that "the phenomena we call thought, evolution, ecology, life, learning and the like occur only in sytems that satisfy these criteria," (2002, p. 86). Mind and nature are, as his book title (Bateson 2002) states, are a necessary unity

Temporalités des cadres et malaise au travail

21p.International audienceThe CERTOP's team achieved a research on executives and high skilled employees in France (in French: cadres) about their working time, their involvement in their professional life and their social temporalities characterizing their everyday life. This research has been financed by the national agency for research and carried out in seven companies and administrations. The approach is based on 100 interviews with a transcribed text corpus of 600,000 words. It is used to identify the existence of a complex ill-being at work. On the one hand, this ill-being appears around three major difficulties: stress, lack of symbolic recognition and social tensions within the company. On the other hand, this discomfort should be analyzed by taking into account the well-being that the high skilled employees still express concerning their activity. Overall the article describes the nuanced portrait of a social category that is characterized by its heterogeneity, but also by a desire to escape temporality constraints and time- urgency in order to find a quality of life that reinvests the private sphere.L'équipe du CERTOP a mené une recherche sur les cadres en France, leur temps de travail, l'implication dans leur vie professionnelle et sur les temporalités sociales qui caractérisent leur quotidien. Cette recherche, financée par l'agence nationale de la recherche (ANR), a été menée dans sept entreprises et administrations. La démarche fondée sur la base de 100 entretiens retranscrits avec un corpus textuel de 600 000 mots permet de montrer et de circonscrire l'existence complexe d'un mal-être au travail. Celui-ci s'exprime d'une part autour de trois difficultés majeures : le stress, l'absence de reconnaissance symbolique de la contribution fournie, les tensions sociales au sein de l'entreprise. D'autre part, ce mal-être doit être analysé en prenant en compte le bien-être que les cadres expriment toujours concernant leur activité. Dans l'ensemble l'article dresse le portrait nuancé d'une catégorie sociale qui se caractérise par son hétérogénéité, mais aussi par une volonté d'échapper aux temporalités contraintes et de l'urgence afin de retrouver une qualité de vie qui réinvestit la vie privée

The Effect of the Growth Condition on the Properties of the New Material Sn3Sb2S6 Thin Films

Sulfosalt Sn3Sb2S6 material was synthesised by the horizontal Bridgman method. X-rays diffraction analysis of the powder showed that only homogenous Sn3Sb2S6 phase is present in the ingot. Sn3Sb2S6 thin films were deposited by a single source vacuum thermal evaporation with different thicknesses on glass substrates. The optical and structural properties of the films were studied as a function of thicknesses and temperature substrates. It is interest to note that Sn3Sb2S6 films exhibit polycrystalline structures along (416) preferred plane without heating the substrates. In addition, we note that as the thickness increases from 150 nm to 430 nm the average grain size increases from 190 to 350 °A. The samples have direct bandgap energies of 1.5 - 1.75 eV. Furthermore, we found that the absorption coefficient in all cases reached 104 cm−1. So, Sulfosalt Sn3Sb2S6 thin films could be used as a potential candidate in may technological applications such as photovoltaic solar cell

Les Sapeurs-pompiers, une identité temporelle de métier

Remerciements Il est indispensable de remercier le pôle TONER « Travail, Organisation, Négociation, et Risques » du CERTOP (Centre d'Etude et de Recherche sur Travail, Organisation, Pouvoir) de l'Université de Toulouse-le-Mirail, dirigé par Jens Thoemmes, pour avoir ouvert ses portes et aider à la réalisation de ce travail. Ces remerciements vont en particulier à Jens Thoemmes pour son soutien, son suivi, et sa patience tout au long de ces années, et à Gilbert de Terssac pour sa confiance et son accompagnement éclairé. Un grand merci aux membres du CERTOP, qui ont tous participé à ce parcours de formation et de recherche. Enfin, ce travail n'aurait pas pu être élaboré sans la participation des sapeurs-pompiers de la région Midi-Pyrénées, des salariés de l'usine "AZF", et des entreprises voisines, qui ont accepté de se confier, sans retenue.« Fire brigades, a temporal work identity » Abstract Our thesis has for object the work of fire brigades. This activity is crossed by a significant evolution. On one side, the recent evolution of the profession, with the growth of the interventions of «help to victims» weakens the representation of the "heroic" fireman to transform him into a "social worker". On the other hand, fire brigades maintain their professional commitments and meet the expectations of the population by mobilizing collective values. Our analyses try to show the multiple facets of this emergency work by varying the objects of analysis: negotiation and conflict about working time, interventions during the "AZF"-disaster, observation of the everyday life of fire brigades, computer-aided analysis of their speeches. Our thesis can be quickly summarized. The emergency work of the fire brigade is structured by a temporal identity of profession. The identity of fire brigades builds itself around shared values, which mix subjective representations and history of the profession. The fireman remains a fireman even outside of his professional activities. The formalized organization of the interventions is accompanied with a non-formalized collective organization, dependent on events, but which makes reference in a set of faiths and of commitments directed to the help of the victims. The temporality of this profession constitutes a good indicator of this particular identity: uncommon schedules, the urgency of the interventions, the refusal of the distinction between private life and professional life, a permanent availability. One can't deny those temporalities are social. They break the borders established between the activities, the manners to classify and to measure individuals' efforts. The fire brigade profession questions the usual frame of work analysis. This individuals-“protection” profession is indeed exercised in 85 % by non-professionals. The "volunteers" accentuate the particularity of this professional commitment, on the verge of a classic wage-earner, characterized by association commitment and by an additional professional activity. The temporal identity of profession allows moving the glance on work, his organization and on its economic end. It articulates itself around the self-sacrifice, in welded collectives, with the aim of a public utility of protection, assistance and social solidarity.« Les Sapeurs-pompiers, une identité temporelle de métier » Résumé Notre thèse a pour objet le travail des sapeurs-pompiers. Ce travail est soumis à une évolution notable. D'un côté, l'évolution récente du métier, avec la croissance des interventions de « secours à victimes » affaiblit l'image du pompier « héroïque » pour le transformer en « travailleur social ». D'un autre côté, les pompiers maintiennent leurs engagements professionnels et répondent aux attentes de la population en mobilisant des valeurs collectives. Nos analyses tentent de montrer les multiples facettes de ce travail d'urgence en variant les objets d'analyse : négociation et conflit à propos du temps de travail, interventions lors de la catastrophe "AZF", observation de la vie quotidienne des pompiers, analyse de leurs discours assistée par ordinateur. Notre thèse peut être résumée rapidement. Le travail d'urgence des sapeurs-pompiers est supporté par une identité temporelle de métier. L'identité des pompiers se construit autour de valeurs partagées, de représentations tout autant subjectives qu'imprégnées d'histoire de la profession. Le pompier reste pompier même en dehors de ses activités professionnelles. L'organisation formalisée des interventions est accompagnée d'une organisation collective non-formalisée, tributaire des évènements, mais qui renvoie à un ensemble de croyances et d'engagements orientés vers l'aide des victimes. Les temporalités de cette profession caractérisent bien cette identité particulière : des horaires peu communs, l'urgence des interventions, le refus de la distinction entre vie privée et vie professionnelle, une disponibilité permanente. Ces temporalités sont bien sociales. Elles transgressent les frontières établies entre les activités, les manières de classer et de mesurer l'effort des individus. Le métier de sapeurs-pompiers met en cause les cadres habituels d'analyse du travail. Ce métier de la « protection » des individus est en effet exercé à 85% par des non-professionnels. Les « volontaires » mettent en relief ce type d'engagement professionnel très particulier, à la limite d'un salariat classique, caractérisé par une vie associative et par une activité professionnelle complémentaire. L'identité temporelle de métier permet de déplacer le regard sur le travail, son organisation et sur sa finalité économique. Elle s'articule autour du don de soi, dans des collectifs soudés, en vue d'un service public de protection, du secours et de la solidarité sociale

Effects of Drill Mud and Drive Torque Sinusoidal Excitation on Drillstrings Lateral and Torsional StickSlip Vibrations

Oil and gas drilling companies spend around 20$ billion annually from which 15% is attributed to material and productive time losses. The most prevalent drilling problems are caused by the Bottom-Hole-Assembly failure which includes drill string and drill bit damage or fatigue failure. During normal operation, to achieve penetration that cannot be met by the drilling motor power section, the bit torque generates an increased reactive torque that acts in the opposite direction of the driving rotation. This sudden increase in reactive torque is transmitted through the drill string as torsional 'stick-slip' vibration, which is often regarded as one of the most damaging modes of vibration. Due to cyclical rotation acceleration and deceleration of the bit, Bottom-Hole-Assembly, or drill string, this phenomenon produces accumulation and release of energy stored as several turns of twist in the rotor. While downhole vibrations are difficult to prevent and cannot be totally eradicated, implementing of corrective methods may be highly efficient for drilling optimization. In the present work, the effect of drill mud on drilling dynamics is studied, then, a sinusoidal excitation is added to the drive torque and resulting impact on downhole equipment is presented. A laboratory scale arrangement consisting of a flexible rotor and a stator is used, and attention is paid to whirling and stick-slip motions of the drill string. The results are provided in the form of responses in the time and frequency domains. A non-linear coupled dynamic model of a rotor enclosed within a stator and subjected to non- linear mud film force is developed. Comparisons with simulations data are also included. The work is one of the first studies carried out on the influence of adding a sinusoidal excitation to the driving torque with the use of drill mud on drill-string whirling motions in a laboratory environment.qscienc

Approach for Integrating Indirect Evaporative Cooling System into Contemporary Architecture

Nowadays, the knowledge of building ecology focuses on energy efficiency and how to integrate environmental and climatic parameters into HVAC and thus enhances space qualities such as comfort ability. The aim of this paper is to demonstrate the rule of Indirect Evaporative Cooling systems in sustainability of contemporary architecture in hotarid and hot-humid climate. An approach for integrating a novel Sub-Wet Bulb Temperature Evaporative cooler into contemporary architecture is presented. The system uses porous clay materials, as wet media, embedded with heat pipes heat exchangers, the supply air and working air flows were staged in separate ducts and in counter flow direction. Modelling and experimental results show that supply air would be cooled to below wet bulb temperature achieving a considerable cooling capacity and effectiveness. This performance would make the system a potential alternative to conventional mechanical air conditioning systems in buildings.Qatar National Research , NPRP grant No. 4 -407 -2 -15