2,394 research outputs found
The Fermi Large Area Telescope
The Large Area Telescope, the primary instrument on the Fermi Gamma-ray Space
Telescope, is an imaging, wide field-of-view gamma-ray telescope. After many
improvements to the data acquisition and event analysis procedures, it now
covers the broad energy range from MeV to TeV. After more
than 13 years of operation since its launch in June 11, 2008, it has provided
the best-resolved and deepest portrait of the gamma-ray sky. In this chapter we
review the design of the instrument, the data acquisition system, calibration,
and performance.Comment: 30 pages, 11 figures; Invited chapter for Handbook of X-ray and
Gamma-ray Astrophysics (Eds. C. Bambi and A. Santangelo, Springer Singapore,
expected in 2022
Perlindungan Hukum Bagi Penumpang Pesawat Udara Menurut Undang-undang No. 1 Tahun 2009 Tentang Penerbangan
Penelitian ini dilakukan dengan tujuan untuk mengetahui bagaimana pengaturan hukum terhadap penumpang pesawat udara dan bagaimana upaya perlindungan hukum saat mengalami kerugian pada kegiatan transportasi udara. Dengan menggunakan metode penelitian yuridis normatif dsimpulkan: 1. Dalam sistem hukum di Indonesia sudah terdapat beberapa peraturan di bidang transportasi udara di Indonesia, yaitu Undang-Undang No. 1 Tahun 2009 tentang Penerbangan, Peraturan Menteri Perhubungan No. PM 89 Tahun 2015 tentang Penanganan Keterlambatan Penerbangan (Delay Management) pada Badan Usaha Angkutan Udara Niaga Berjadwal di Indonesia, dan Peraturan Menteri Perhubungan No. 77 Tahun 2011 tentang Tanggung Jawab Pengangkut Angkutan Udara. Adapun dalam kegiatan transportasi udara perlu adanya perjanjian pengangkutan. Dengan adanya perjanjian pengangkutan, hak dan kewajiban para pihak yang terlibat di dalamnya dapat terjamin. 2. Dalam upaya perlindungan hukum saat mengalami kerugian pada kegiatan transportasi udara khususnya transportasi udara niaga, harus kita ketahui dulu bentuk-bentuk kerugian yang dapat dialami dalam kegiatan penerbangan yaitu keterlambatan, kehilangan dan kecelakaan baik yang menyebabkan luka-luka sampai kematian. Dengan meninjau bentuk-bentuk kerugian tersebut, maka ada beberapa aspek yang perlu diperhatikan sehubungan dengan pencegahan dan perlindungan konsumen bahkan semua pihak yang terlibat dalam transportasi udara, yaitu aspek keselamatan penerbangan, aspek kemanan penerbangan, aspek Kenyamanan selama penerbangan, aspek pelayanan, aspek penentuan tarif atau ongkos penerbangan, aspek perjanjian angkutan udara, aspek pengajuan klaim dan aspek perlindungan melalui asuransi.
Kata kunci: Perlindungan hukum, penumpang, pesawat udar
Polyenes and vision
AbstractPolyenes are important for vision in all sighted species. The visual pigments (the rhodopsins) all use 11-cis-retinal as the chromophore; some possible reasons for the importance of this isomer are now emerging. New results on the involvement of xanthophils in the maintenance of the retina are also discussed
Strong Quasiparticle Trapping In A 6x6 Array Of Vanadium-Aluminum Superconducting Tunnel Junctions
A 6x6 array of symmetrical V/Al/AlOx/Al/V Superconducting Tunnel Junctions
(STJs) was fabricated. The base electrode is a high quality epitaxial film with
a residual resistance ratio (RRR) of ~30. The top film is polycrystalline with
an RRR of ~10. The leakage currents of the 25x25 mm^2 junctions are of the
order of 0.5 pA/mm^2 at a bias voltage of 100 mV, which corresponds to a
dynamical resistance of ~ 3 10^5 ohms. When the array was illuminated by 6 keV
X-ray photons from a 55Fe radioactive source the single photon charge output
was found to be low and strongly dependent on the temperature of the devices.
This temperature dependence at X-ray energies can be explained by the existence
of a very large number of quasiparticle (QP) traps in the Vanadium. QPs are
confined in these traps, having a lower energy gap than the surrounding
material, and are therefore not available for tunneling. The number of traps
can be derived from the energy dependence of the responsivity of the devices
(charge output per electron volt of photon input energy).Comment: 4 pages. presented at Low Temperature Detectors-
First results of a cryogenic optical photon counting imaging spectrometer using a DROID array
Context. In this paper we present the first system test in which we
demonstrate the concept of using an array of Distributed Read Out Imaging
Devices (DROIDs) for optical photon detection. Aims. After the successful S-Cam
3 detector the next step in the development of a cryogenic optical photon
counting imaging spectrometer under the S-Cam project is to increase the field
of view using DROIDs. With this modification the field of view of the camera
has been increased by a factor of 5 in area, while keeping the number of
readout channels the same. Methods. The test has been performed using the
flexible S-Cam 3 system and exchanging the 10x12 Superconducting Tunnel
Junction array for a 3x20 DROID array. The extra data reduction needed with
DROIDs is performed offline. Results. We show that, although the responsivity
(number of tunnelled quasiparticles per unit of absorbed photon energy, e- /eV)
of the current array is too low for direct astronomical applications, the
imaging quality is already good enough for pattern detection, and will improve
further with increasing responsivity. Conclusions. The obtained knowledge can
be used to optimise the system for the use of DROIDs.Comment: 7 pages, 9 figures, accepted for publicaiton in A&
E-ASTROGAM: A space mission for MeV-GeV gamma-ray astrophysics
e-ASTROGAM is an observatory space mission dedicated to the study of the gamma radiation in the range from 0.3 MeV to 3 GeV. The detector is composed by a Silicon tracker, a calorimeter, and an anticoincidence system. The mission is based on an advanced space-proven detector technology, with unprecedented sensitivity, angular and energy resolution, combined with polarimetric capability. Thanks to its performance in the MeV-GeV domain, substantially improving its predecessors, eASTROGAM will open a new window on the non-thermal Universe. In particular it will determine the origin of key isotopes fundamental for the understanding of supernova explosions and the chemical evolution of our Galaxy. It will also shed light on the processes behind the acceleration of cosmic rays in our Galaxy
Sheep α-globin gene sequences: Implications for their concerted evolution and for the down-regulation of the 3' genes
In sheep as in man and most other mammals, there are two α-globin genes (Iα and IIα), which are expressed at different levels, the upstream gene being the most efficient. In α-globin gene triplication and quadruplication, this trend is confirmed, i.e., the α-chain output of the downstream genes progressively decreases. In this study, we have determined the complete sequence of the cDNAs and of both the introns in a triple-α haplotype in which each gene could be recognized for the presence of distinct alleles. The sequence analysis reveals that the bodies of the three α-globin genes are essentially identical (99.9% homology) and moreover indicates that the down-regulation of additional α-globin genes in sheep is not the effect of sequence variation from the Cap to the Poly(A) addition sites. This striking similarity among α-genes is higher than that seen in other mammals and is probably sustained by particularly efficient mechanisms of gene conversion and cross-over fixation
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