66 research outputs found

    A macroeconomics-inspired interpretation of the terrestrial water cycle

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    This article develops an approach that applies macroeconomic concepts to the interpretation of complex, water related natural processes. By translating and reinterpreting these processes into a language that is more accessible to a broader audience otherwise unaccustomed to its terms will likely help sharpen our understanding of the terrestrial water cycle. For economists, we describe climate-forming natural processes in a manner consistent with the fundamentals of the mainstream approach. For noneconomists, parallels from economically determined, relatively short-term observations can be applied conceptually to identify dynamics which occur over much longer and therefore more elusive natural occurrences, in particular considering the role of forests and how persistent land conversion over a millennium has shaped the earth's surface and impacted climate stability. The set of “supporting ecosystem services” highlighted in the Millennium Ecosystem Assessment (MEA) coincides with the ground phase of the terrestrial water cycle, taking the concept beyond the ecosystem service perspective and identifying it as a planetary service. Ecosystem and planetary services differ in the same way that microeconomic and macroeconomic perspectives do. The water cycle intensity of a geographical area may well be related to a rainfall multiplier that measures the ability of continental ecosystems to increase the amount of water moving across terrestrial surfaces and descending as rainfall through transpiration and deposition, and re-transpiration and re-deposition of the water content in the air that originally arrives from the oceans. Building upon the MEA's association of human wellbeing with ecosystem features, the rainfall multiplier serves as a physical indicator and measure of the natural basis of wellbeing creation

    VHMPID: a new detector for the ALICE experiment at LHC

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    This article presents the basic idea of VHMPID, an upgrade detector for the ALICE experiment at LHC, CERN. The main goal of this detector is to extend the particle identification capabilities of ALICE to give more insight into the evolution of the hot and dense matter created in Pb-Pb collisions. Starting from the physics motivations and working principles the challenges and current status of development is detailed.Comment: 4 pages, 6 figures. To be published in EPJ Web of Conference

    Cryptocapsinepoxide-type Carotenoids from Red Mamey, Pouteria sapota

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    Three new carotenoids, cryptocapsin-5,6-epoxide, 3ʹ-deoxycapsanthin-5,6-epoxide, and cryptocapsin-5,8-epoxides, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Cryptocapsin-5,6-epoxide was prepared by partial synthesis via epoxidation of cryptocapsin and the (5R,6S)- and (5S,6R)-stereoisomers were identified by HPLC-ECD analysis. Spectroscopic data of the natural (anti) and semisynthetic (syn) derivatives obtained by acid-catalyzed rearrangement of cryptocapsin-5,8-epoxide stereoisomers were compared for structural elucidation. Chiral HPLC separation of natural and semisynthetic samples of cryptocapsin-5,8-epoxides was performed and HPLC-ECD analysis allowed configurational assignment of the separated stereoisomers

    Status of the mid-IR ELT imager and spectrograph (METIS)

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    The Mid-Infrared ELT Imager and Spectrograph (METIS) is one of three first light instruments on the ELT. It will provide high-contrast imaging and medium resolution, slit-spectroscopy from 3 - 19um, as well as high resolution (R ∼ 100,000) integral field spectroscopy from 2.9-5.3μm. All modes observe at the diffraction limit of the ELT, by means of adaptive optics, yielding angular resolutions of a few tens of milliarcseconds. The range of METIS science is broad, from Solar System objects to active galactic nuclei (AGN). We will present an update on the main science drivers for METIS: circum-stellar disks and exoplanets. The METIS project is now in full steam, approaching its preliminary design review (PDR) in 2018. In this paper we will present the current status of its optical, mechanical and thermal design as well as operational aspects. We will also discuss the challenges of building an instrument for the ELT, and the required technologies. © 2018 SPIE

    Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE

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    Stars and planetary system

    Final optical design for the WEAVE two-degree prime focus corrector: Proceedings Volume 9147, Ground-based and Airborne Instrumentation for Astronomy V; 914773 (2014)

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    WEAVE is the next-generation wide-field optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. We present the final optical design for the two-degree Prime Focus Corrector (PFC) for the WHT optimised for WEAVE. The nominal optical design provides a polychromatic PSF that does not exceed 0.6 arcsec (80% encircled energy diameter) over a wavelength range from 370 to 1000 nm covering a two-degree field-of-view (FOV) for zenith angles up to 65 degrees. We describe the optical issues that had to be addressed prior to the Final Design Review (FDR) and present the trade-offs that were necessary between manufacturability and performance. We detail the results of an in-depth Monte Carlo simulation that contains all the manufacturing, alignment and stability issues that affect the PSF error budget of the Prime Focus Corrector. As a result of multiple iterations regarding the different tolerances of the system, the polychromatic PSF (80% encircled energy diameter) including all errors stays below the required 1 arcsec
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