8,466 research outputs found

    Improved relay optical element for spectroradiometer using cryogenically cooled detector

    Get PDF
    By coating half of one element in the relay optical system of a spectroradiometer with a very high emissivity paint, the effect of the reflected radiation from the back of the filter wheel is eliminated optically. This causes the detector to view a constant level of radiation, regardless of how the reflectivity of the back of the filter wheel changes

    Observations of Outflowing UV Absorbers in NGC 4051 with the Cosmic Origins Spectrograph

    Full text link
    We present new Hubble Space Telescope (HST)/Cosmic Origins Spectrograph observations of the Narrow-Line Seyfert 1 galaxy NGC 4051. These data were obtained as part of a coordinated observing program including X-ray observations with the Chandra/High Energy Transmission Grating (HETG) Spectrometer and Suzaku. We detected nine kinematic components of UV absorption, which were previously identified using the HST/Space Telescope Imaging Spectrograph. None of the absorption components showed evidence for changes in column density or profile within the \sim 10 yr between the STIS and COS observations, which we interpret as evidence of 1) saturation, for the stronger components, or 2) very low densities, i.e., n_H < 1 cm^-3, for the weaker components. After applying a +200 km s^-1 offset to the HETG spectrum, we found that the radial velocities of the UV absorbers lay within the O VII profile. Based on photoionization models, we suggest that, while UV components 2, 5 and 7 produce significant O VII absorption, the bulk of the X-ray absorption detected in the HETG analysis occurs in more highly ionized gas. Moreover, the mass loss rate is dominated by high ionization gas which lacks a significant UV footprint.Comment: 41 pages, 10 Figures; accepted for publication in the Astrophysical Journa

    Whose forests, whose voices? Mining and community- based nature conservation in southeastern Madagascar

    Get PDF
    This paper explores local experiences of private - sector led community - based nature conservation near Fort Dauphin, southeastern Madagascar through the analysis of a conservation zone managed in partnership between the Rio Tinto mining corporation, local government and local communities. The article assesses how new forms of social inclusion and exclusion are generated through changes in land and resource access. The main findings are as follows: the community - based conservation programs near the Fort Dauphin mine were effective at mobilising local people but inadvertently favored certain members of society over others, as they involved a legitimization of resource access by established landowners. This granting of resource rights to some local users entailed the exclusion of already marginalised groups of landless migrants. Without land to cultivate, these migrants were more directly dependent on forest resources for their survival. Their livelihoods were based on selling forest products such as timber and handicrafts, in addition to working the land of others. This rendered their social status and ability to participate in development programs limited. Non - resident or recently settled resource users&#8217; voices had thereby not been adequately included in the conservation plans from the outset. Consequently, local landless migrants continued to break conservation rules, as they had no influence over the resource management process or realistic livelihoods alternatives. These circumstances reduced both the livelihood options of the poorest people near the mining site and the prospect of achieving equitable and sustainable natural resource management.R&#201;SUM&#201;Nous proposons ici d&#8217;analyser des exp&#233;riences locales intervenant lors du changement d&#8217;acc&#232;s aux ressources naturelles dans le cadre d&#8217;un projet d&#8217;extraction mini&#232;re et de conservation de la nature men&#233; en partenariat entre une compagnie mini&#232;re, le gouvernement local et les communaut&#233;s riveraines d&#8217;un site minier pr&#232;s de Fort Dauphin, dans le Sud - est de Madagascar. Les informations ont &#233;t&#233; recueillies lors d&#8217;une ann&#233;e de recherches ethnographiques financ&#233;es par le Conseil de Recherche Norv&#233;gien, aux alentours de la zone mini&#232;re et de son site de conservation. Les changements d&#8217;acc&#232;s &#224; la terre et aux ressources naturelles induisent de nouveaux types d&#8217;inclusion et d&#8217;exclusion sociaux que nous avons &#233;tudi&#233;s ici. Nous montrons que les programmes communautaires de conservation de la nature et de d&#233;veloppement local &#233;tablis aupr&#232;s du site minier ont permis de mobiliser les villageois riverains, mais ont par m&#233;garde cr&#233;&#233; des disparit&#233;s entre certains membres de la soci&#233;t&#233; locale. Nous avons ainsi not&#233; une augmentationde la diff&#233;rentiation sociale des propri&#233;taires terriens traditionnels qui pouvaient revendiquer la l&#233;gitimation des acc&#232;s aux ressources naturelles. Cette l&#233;gitimation se d&#233;roulait au cours d&#8217;une approche participative de cogestion environnementale, qui supposait un rang social &#233;lev&#233; des participants mais aussi leur disponibilit&#233; pour pouvoir participer &#224; ces programmes communautaires. Certains groupes extr&#234;mement vuln&#233;rables comme les migrants sans terres ont ainsi &#233;t&#233; involontairement exclus &#224; cause de cet octroi du droit d&#8217;acc&#232;s aux ressources naturelles en faveur de certains groupes d&#8217;utilisateurs. En outre, sans terre &#224; cultiver, ces migrants d&#233;pendaient encore davantage des ressources foresti&#232;res pour assurer leur survie quotidienne. Leurs moyens de subsistance se limitaient &#224; la vente de produits forestiers tels que le bois d&#8217;oeuvre ou encore les roseaux pour l&#8217;artisanat. Une autre strat&#233;gie de survie importante pour les migrants sans terre &#233;tait d&#8217;assurer la culture des terrains des propri&#233;taires existants, permettant ainsi ces derniers &#224; participer plus activement aux nouveaux programmes de gestion et d&#233;veloppement local. En outre, les personnes les plus marginalis&#233;es r&#233;sidaient souvent &#224; l&#8217;ext&#233;rieur des communes qui h&#233;bergeaient la zone de conservation et d&#8217;extraction mini&#232;re, dans la mesure o&#249; il n&#8217;y avait plus de terre disponible dans ces communes. Le programme de conservation communautaire men&#233; par la corporation mini&#232;re &#233;tait bas&#233; sur la mise en relation du droit aux ressources naturelles et de la r&#233;sidence dans la commune h&#233;bergeant ces ressources. Or les personnes r&#233;sidant hors de ces communes ou les personnes r&#233;cemment install&#233;es et de statut social bas, &#233;taient ainsi exclues dans la planification et la mise en oeuvre de la gestion communautaire des ressources locales. Par cons&#233;quent, les migrants sans terre ne respectaient pas les lois de conservation communautaire, car ils n&#8217;ont pas pu influencer la proc&#233;dure d&#8217;&#233;tablissement des r&#232;gles de gestion conjointes, ni acc&#233;der aux programmes d&#8217;activit&#233;s g&#233;n&#233;ratrices de revenus alternatifs. Ces circonstances ont ainsi fait ressortir les limites de l&#8217;approche de conservation communautaire destin&#233;e &#224; att&#233;nuer les impacts environnementaux du projet minier et &#224; r&#233;soudre les conflits sociaux y aff&#233;rents

    Analysis of a class of integro -differential equations describing age dynamics of a natural forest

    Get PDF

    Corporate Law

    Get PDF

    Crew interface definition study, phase 1

    Get PDF
    The timeline analysis of the Shuttle orbiter missions which was conducted in the Phase I Crew Interface Definition Study and the requirements for the man-in-the-loop simulation study are presented. Mission definitions and objectives are presented as they relate to various Shuttle Orbiter missions. The requirements for crew participation and the information required by the crew are discussed, and finally the rationale behind the display concept and calling procedures is given. The simulation objectives, the simulation mechanization, including a detailed presentation of the display and control concept, the simulator test plan and the results are discussed
    corecore