| 1. |
- Acharya, B. S., et al.
(författare)
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Introducing the CTA concept
- 2013
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Ingår i: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 43, s. 3-18
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The Cherenkov Telescope Array (CTA) is a new observatory for very high-energy (VHE) gamma rays. CTA has ambitions science goals, for which it is necessary to achieve full-sky coverage, to improve the sensitivity by about an order of magnitude, to span about four decades of energy, from a few tens of GeV to above 100 TeV with enhanced angular and energy resolutions over existing VHE gamma-ray observatories. An international collaboration has formed with more than 1000 members from 27 countries in Europe, Asia, Africa and North and South America. In 2010 the CTA Consortium completed a Design Study and started a three-year Preparatory Phase which leads to production readiness of CTA in 2014. In this paper we introduce the science goals and the concept of CTA, and provide an overview of the project. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Actis, M., et al.
(författare)
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Design concepts for the Cherenkov Telescope Array CTA : an advanced facility for ground-based high-energy gamma-ray astronomy
- 2011
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Ingår i: Experimental astronomy. - : Springer. - 0922-6435 .- 1572-9508. ; 32:3, s. 193-316
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Tidskriftsartikel (refereegranskat)abstract
- Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.
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| 3. |
- Albrecht, Matthias, et al.
(författare)
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The effectiveness of flower strips and hedgerows on pest control, pollination services and crop yield : a quantitative synthesis
- 2020
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 23:10, s. 1488-1498
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Tidskriftsartikel (refereegranskat)abstract
- Floral plantings are promoted to foster ecological intensification of agriculture through provisioning of ecosystem services. However, a comprehensive assessment of the effectiveness of different floral plantings, their characteristics and consequences for crop yield is lacking. Here we quantified the impacts of flower strips and hedgerows on pest control (18 studies) and pollination services (17 studies) in adjacent crops in North America, Europe and New Zealand. Flower strips, but not hedgerows, enhanced pest control services in adjacent fields by 16% on average. However, effects on crop pollination and yield were more variable. Our synthesis identifies several important drivers of variability in effectiveness of plantings: pollination services declined exponentially with distance from plantings, and perennial and older flower strips with higher flowering plant diversity enhanced pollination more effectively. These findings provide promising pathways to optimise floral plantings to more effectively contribute to ecosystem service delivery and ecological intensification of agriculture in the future.
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| 4. |
- Börjesson, Karl, 1982, et al.
(författare)
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Exploring the Potential of Fulvalene Dimetals as Platforms for Molecular Solar Thermal Energy Storage: Computations, Syntheses, Structures, Kinetics, and Catalysis
- 2014
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Ingår i: Chemistry - A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 20:47, s. 15587-15604
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Tidskriftsartikel (refereegranskat)abstract
- A study of the scope and limitations of varying the ligand framework around the dinuclear core of FvRu(2) in its function as a molecular solar thermal energy storage framework is presented. It includes DFT calculations probing the effect of substituents, other metals, and CO exchange for other ligands on Delta H-storage. Experimentally, the system is shown to be robust in as much as it tolerates a number of variations, except for the identity of the metal and certain substitution patterns. Failures include 1,1',3,3'-tetra-tert-butyl (4), 1,2,2',3'-tetraphenyl (9), diiron (28), diosmium (24), mixed iron-ruthenium (27), dimolybdenum (29), and di-tungsten (30) derivatives. An extensive screen of potential catalysts for the thermal reversal identified AgNO3-SiO2 as a good candidate, although catalyst decomposition remains a challenge.
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| 5. |
- Moth-Poulsen, Kasper, 1978, et al.
(författare)
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Molecular solar thermal (MOST) energy storage and release system
- 2012
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Ingår i: Energy and Environmental Sciences. - : Royal Society of Chemistry (RSC). - 1754-5692 .- 1754-5706. ; 5:9, s. 8534-8537
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Tidskriftsartikel (refereegranskat)abstract
- A device for solar energy storage and release based on a reversible chemical reaction is demonstrated. A highly soluble derivative of a (fulvalene) diruthenium (FvRu(2)) system is synthesized, capable of storing solar energy (110 J g(-1)) in the form of chemical bonds and then releasing it "on demand", when excited thermally or catalytically. A microfluidic device is designed and constructed for both the photo-harvesting and the heat-utilization steps, allowing for the recycling of material.
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| 6. |
- Appelt, W. H., et al.
(författare)
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Lattice dynamics of palladium in the presence of electronic correlations
- 2020
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Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 101:7
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Tidskriftsartikel (refereegranskat)abstract
- We compute the phonon dispersion, density of states, and the Gruneisen parameters of bulk palladium in the combined density functional theory (DFT) and dynamical mean-field theory. We find good agreement with experimental results for ground-state properties (equilibrium lattice parameter and bulk modulus) and the experimentally measured phonon spectra. We demonstrate that at temperatures T less than or similar to( )20 K the phonon frequency in the vicinity of the Kohn anomaly, omega(T1)(q(K)), strongly decreases. This is in contrast to DFT where this frequency remains essentially constant in the whole temperature range. Apparently, correlation effects reduce the restoring force of the ionic displacements at low temperatures, leading to a mode softening.
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| 7. |
- Oestlin, A., et al.
(författare)
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Ab initio typical medium theory of substitutional disorder
- 2020
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Ingår i: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 101:1
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Tidskriftsartikel (refereegranskat)abstract
- By merging single-site typical medium theory with density-functional theory, we introduce a self-consistent framework for electronic-structure calculations of materials with substitutional disorder which takes into account Anderson localization. The scheme and details of the implementation are presented and applied to the hypothetical alloy LicBe1-c, and the results are compared with those obtained with the coherent potential approximation. Furthermore, we demonstrate that Anderson localization suppresses ferromagnetic order for a very low concentration of (i) carbon impurities substituting oxygen in MgO1-cCc and (ii) manganese impurities substituting magnesium in Mg1-cMncO for the low-spin magnetic configuration.
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