| 1. |
- Abdo, A. A., et al.
(författare)
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The second Fermi large area telescope catalog of gamma-ray pulsars
- 2013
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Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 208:2, s. 17-
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Tidskriftsartikel (refereegranskat)abstract
- This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.
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| 2. |
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| 3. |
- Alme, J., et al.
(författare)
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The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events
- 2010
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 622:1, s. 316-367
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Tidskriftsartikel (refereegranskat)abstract
- The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m(3) and is operated in a 0.5T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb-Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate results close to those specified in the TPC Technical Design Report. (C) 2010 CERN for the benefit of the ALICE collaboration. Published by Elsevier B.V. All rights reserved.
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| 4. |
- Korpan, Yaroslav I., et al.
(författare)
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Formaldehyde-sensitive conductometric sensors based on commercial and recombinant formaldehyde dehydrogenase
- 2010
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Ingår i: Microchimica Acta. - : Springer Science and Business Media LLC. - 1436-5073 .- 0026-3672. ; 170:3-4, s. 337-344
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Tidskriftsartikel (refereegranskat)abstract
- Novel formaldehyde-sensitive conductometric biosensors have been developed that are based on commercial bacterial formaldehyde dehydrogenase (FDH) from Pseudomonas putida and recombinant formaldehyde dehydrogenase (rFDH) from the yeast Hansenula polymorpha as the bio-recognition elements. The bio-recognition membranes have mono-layer architecture and consist of enzyme cross-linked with albumin and of the cofactors NAD (for FDH-based sensor) or NAD and glutathione (for rFDH-based sensor). This architecture of the biosensor allows the determination of formaldehyde without adding NAD and glutathione to the analyzed sample at every analysis and conducting measurements on the same transducer without cofactors regeneration since the bio-membrane contains it at high concentration (100 mM for NAD and 20 mM for glutathione). The response is linear in the range from 10 to 200 mM of formaldehyde concentration depending on the enzyme used. The dependence of the biosensor output signals on pH and buffer concentration as well as operational/storage stability and selectivity/specificity of the developed conductometric biosensors have been investigated. The relative standard deviation of the intra-sensor response did not exceed 4% and 10% for rFDH- and FDH-based sensors, respectively. The relative standard deviation of the inter-sensor response constituted 20% for both dehydrogenases used. The biosensors have been validated for formaldehyde detection in some real samples of pharmaceutical (Formidron), disinfectant (Descoton forte) and an industrial product (Formalin). A good correlation does exist between the concentration values measured by the conductometric biosensor developed in this work, an enzymatic method, amperometric biosensors developed earlier, and standard analytical methods of formaldehyde determination.
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