Search results for "Environment"
showing 10 items of 28487 documents
Spectral properties of X-ray bright variable sources in the Taurus Molecular Cloud
2006
We analyze 19 bright variable X-ray sources detected in the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST), in order to characterize the variations with time of their coronal properties and to derive informations on the X-ray emitting structures. We performed time-resolved spectroscopy of the EPIC PN and MOS spectra of the XEST sources, using a model with one or two thermal components, and we used the time evolution of the temperatures and emission measures during the decay phase of flares to derive the size of the flaring loops. The light curves of the selected sources show different types of variability: flares, long-lasting decay or rise through the whole observation, sl…
Stochastic gravito-inertial modes discovered by CoRoT in the hot Be star HD 51452
2012
International audience; Context. Be stars are rapidly rotating stars with a circumstellar decretion disk. They usually undergo pressure and/or gravity pulsation modes excited by the κ-mechanism, i.e. an effect of the opacity of iron-peak elements in the envelope of the star. In the Milky Way, p-modes are observed in stars that are hotter than or equal to the B3 spectral type, while g-modes are observed at the B2 spectral type and cooler. Aims. We observed a B0IVe star, HD 51452, with the high-precision, high-cadence photometric CoRoT satellite and high-resolution, ground-based HARPS and SOPHIE spectrographs to study its pulsations in great detail. We also used the lower resolution spectra a…
Chemical Cartography with APOGEE: Multi-element Abundance Ratios
2019
We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars measured by the SDSS/APOGEE survey (O, Na, Mg, Al, Si, P, S, K, Ca, V, Cr, Mn, Fe, Co, Ni). Adopting Mg rather than Fe as our reference element, and separating stars into two populations based on [Fe/Mg], we find that the median trends of [X/Mg] vs. [Mg/H] in each population are nearly independent of location in the Galaxy. The full multi-element cartography can be summarized by combining these nearly universal median sequences with our measured metallicity distribution functions and the relative proportions of the lo…
The Gaia-ESO Survey: impact of extra mixing on C and N abundances of giant stars
2018
The GES survey using FLAMES at the VLT has obtained high-resolution UVES spectra for a large number of giant stars, allowing a determination of the abundances of the key chemical elements C and N at their surface. The surface abundances of these chemical species are well-known to change in stars during their evolution on the red giant branch after the first dredge-up episod, as a result of extra-mixing phenomena. We investigate the effects of thermohaline mixing on C and N abundances using the first comparison between the GES [C/N] determinations with simulations of the observed fields using a model of stellar population synthesis. We explore the effects of thermohaline mixing on the chemic…
IEL.21-22-Unit 3. The application of International Environmental Law
2022
International Environmental Law. Unit 3. The Application of International Environmental Law. Powerpoint of the Academic course 2021-2022. 15. UNIT 3.-THE APPLICATION OF INTERNATIONAL ENVIRONMENTAL LAW. 1. General aspects: control procedures and bodies - 2. International liability in international environmental law: (a) general aspects; (b) liability for unlawful acts and international environmental crime; (c) liability of States for environmental damage resulting from acts not prohibited by international law - 3. Peaceful settlement of international disputes concerning the protection of the environment.
Using uncertain preferential information from stakeholders to assess the acceptability of alternative forest management plans
2017
In forest management planning, participatory planning processes are often encouraged as a means to acquire relevant information and to enhance the stakeholders' acceptability of alternative plans. This requires the aggregation of the stakeholders' preferences that can be done in a wide variety of manners. The aggregation process strives to reduce the information into a single set of preferences that simplifies the information and allows for the use of discrete decision support tools. Depending on how the preferences are aggregated, a wide range of plan rankings can emerge. Although this range of ranking complicates the issue of plan selection, it does highlight the uncertainty involved in a…
Regulating role of lumbricid macrofauna in Atrazine biodegradation in temperate cropped soil.
2004
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Interactions biotiques entre macrofaune lombricienne et les communautés microbiennes, indigènes et bioaugmentées, dégradant l'atrazine en sol tempéré.
2004
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Biodégradation de l'atrazine en sols tempérés : rôle régulateur d'un modèle d'interaction biotique macrofaune/bactérie.
2004
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Effects of integrating a bioethanol production process to a kraft pulp mill
2010
Abstract The integration of an ethanol production process based on prehydrolysis of softwood chips to a kraft pulp mill is discussed. A simulation model of this biorefinery has been created with WinGEMS simulation software to calculate the mass and energy balances of the biorefinery and to examine the effects of the integration on the operation of the pulp mill. Integrating the prehydrolysis process to the modeled pulp mill producing 1000 Adt/day of pine pulp would increase the wood consumption by 16%. With the increased wood consumption, 40 t/day of ethanol could be produced, and the excess power production could be increased by 460 MWh/day. The integration of the ethanol production proces…