| 1. |
- 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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| 2. |
- Murray, Alison E., et al.
(författare)
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Roadmap for naming uncultivated Archaea and Bacteria
- 2020
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Ingår i: Nature Microbiology. - : NATURE PUBLISHING GROUP. - 2058-5276. ; 5:8, s. 987-994
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Tidskriftsartikel (refereegranskat)abstract
- The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as 'type material', thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity. In this Consensus Statement, the authors discuss the issue of naming uncultivated prokaryotic microorganisms, which currently do not have a formal nomenclature system due to a lack of type material or cultured representatives, and propose two recommendations including the recognition of DNA sequences as type material.
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| 3. |
- Palacz, M, et al.
(författare)
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In beam gamma-ray spectroscopy of very neutron deficient odd-cadmium isotopes
- 1997
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Ingår i: Acta Physica Polonica B. - : ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS. - 0587-4254 .- 1509-5770. ; 28:1-2, s. 309-313
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in the very neutron deficient odd cadmium isotopes Cd-99, Cd-101 and Cd-103 are discussed in terms of the nuclear shell model. Systematics of excited states in Cd99-109 is presented.
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| 4. |
- Persson, J, et al.
(författare)
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New spectroscopic data on Cd-102
- 1996
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Ingår i: Acta Physica Polonica B. - : POLISH ACAD SCIENCES INST PHYSICS. - 0587-4254 .- 1509-5770. ; 27:1-2, s. 171-178
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Tidskriftsartikel (refereegranskat)abstract
- Gamma ray spectroscopy of neutron deficient nuclei close to the doubly magic nucleus Sn-100 has been performed using a heavy-ion reaction and the NORDBALL Ge-detector array. Evaporation residues were identified by means of charged particle and neutron detection. Transitions in 31 different evaporation residues were identified. New results on Cd-102 are presented.
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| 5. |
- Gorska, M, et al.
(författare)
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Cd-98(48)50 : The two-proton-hole spectrum in Sn-100(50)50
- 1997
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 79:13, s. 2415-2418
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in Cd-98, two proton holes from Sn-100, were identified and studied for the first time, using in-beam spectroscopy with highly selective ancillary detectors. The structure of the (pi g(9/2))(-2) two-proton-hole spectrum below a T-1/2 = 0.48(16) mu s isomer is deduced and compared to shell-model predictions. A tentative I-pi = (8(+)) assignment, as suggested by systematics, yields a strongly reduced B(E2,8(+) --> 6(+)) = 0.44((+20)(-10)) W.u., corresponding to an effective proton charge of e(pi) = 0.85((+20)(-10))e, which is at variance with existing theoretical predictions.
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| 6. |
- Gorska, M, et al.
(författare)
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Spectroscopy of the T-z=1 nuclei close to Sn-100
- 1997
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 28:1-2, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- The two nuclei Cd-98 and Sn-102, closest neighbours of Sn-100, have been studied with a recoil catcher setup, following the reactions: Ni-58(Ti-46, alpha 2n)Cd-98 and Ni-58(Cr-50, alpha 2n)Sn-102. Long lived isomeric states were measured in Cd-98 I-pi = (8+), t(1/2) = 0.48(8) mu s and in Sn-102 I-pi = (6(+)) with t(1/2) = 1.0(6) mu s. The proposed experimental level schemes of the isomeric decay are presented and compared to the shell model predictions.
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| 7. |
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| 8. |
- Hawkes, N. C., et al.
(författare)
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Observation of zero current density in the core of JET discharges with lower hybrid heating and current drive
- 2001
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 8711:11, s. art. no.-115001
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Tidskriftsartikel (refereegranskat)abstract
- Simultaneous current ramping and application of lower hybrid heating and current drive (LHCD) have produced a region with zero current density within measurement errors in the core (r/a less than or equal to 0.2) of JET tokamak optimized shear discharges. The reduction of core current density is consistent with a simple physical explanation and numerical simulations of radial current diffusion including the effects of LHCD. However, the core current density is clamped at zero, indicating the existence of a physical mechanism which prevents it from becoming negative.
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| 9. |
- Hawkes, N. C., et al.
(författare)
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The formation and evolution of extreme shear reversal in JET and its influence on local thermal transport
- 2002
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 0741-3335 .- 1361-6587. ; 44:7, s. 1105-1125
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Tidskriftsartikel (refereegranskat)abstract
- In JET discharges where lower hybrid heating and current drive (LHCD) is applied early during the current ramp, a region of the plasma with zero current density is formed near the axis. At the boundary of this region the current density is large and B-theta increases rapidly over a small distance. In the central region the safety factor, q, is effectively infinite, but this falls steeply in the boundary region. Outside the boundary region q reaches a minimum, where the magnetic shears equivalent to r/q (dq/dr) becomes zero. The formation of this region of zero current is dependent on both the heating and the current drive effects of the LHCD. When LHCD is switched off the current profile begins to relax towards the resistive peaked current distribution of fully inductive tokamak operation. If LHCD is not used in the current rise then these current profiles are not established. Although the physical mechanism exists to drive the central plasma current below zero, in most cases it appears to be prevented from going negative. At least one MHD mechanism has been identified which could be responsible for this. The presence of the zero central current is closely linked to the periodic relaxation events seen in these discharges. In these discharges, internal transport barriers have been observed with additional heating powers substantially below the values required to obtain barriers in monotonic q profile cases.
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| 10. |
- LAGERKVIST, CI, et al.
(författare)
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PHYSICAL STUDIES OF ASTEROIDS .29. PHOTOMETRY AND ANALYSIS OF 27 ASTEROIDS
- 1995
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Ingår i: ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES. - : EDITIONS PHYSIQUE. - 0365-0138. ; 113:1, s. 115-129
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Tidskriftsartikel (refereegranskat)abstract
- In this paper photometry and analysis of 27 asteroids are presented. For the asteroids 21 Lutetia, 23 Thalia, 250 Bettina and 135 Hertha spin vector determinations were made. For asteroid 99 Dike we derived a rotation period of 10.35 hours and for 1280 Ba
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