Search results for "Medium"
showing 10 items of 3746 documents
XMM Optical Monitor Survey of TMC
2007
The Optical Monitor (OM) on-board XMM-Newton obtained optical/ultraviolet data for the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST), simultaneously with the X-ray detectors. With the XEST OM data, we study the optical and ultraviolet properties of TMC members, and to perform correlative studies between the X-ray and OM light curves. In particular, we aim to determine whether accretion plays a significant role in the optical/ultraviolet and X-ray emissions. The Neupert effect in stellar flares is also investigated. Coordinates, average count rates and magnitudes were extracted from OM images, together with light curves with low time resolution (a few kiloseconds). For a fe…
MOJAVE. XIII. New 15GHz observations on 1994-2013
2017
We present 1625 new 15GHz (2cm) VLBA images of 295 jets associated with active galactic nuclei (AGNs) from the MOJAVE and 2cm VLBA surveys, spanning observations between 1994 August 31 and 2013 August 20. For 274 AGNs with at least 5 VLBA epochs, we have analyzed the kinematics of 961 individual bright features in their parsec-scale jets. A total of 122 of these jets have not been previously analyzed by the MOJAVE program. In the case of 451 jet features that had at least 10 epochs, we also examined their kinematics for possible accelerations. At least half of the well-sampled features have non-radial and/or accelerating trajectories, indicating that non-ballistic motion is common in AGN je…
Radio-optical scrutiny of compact AGN
2010
We study the correlations between the VLBA (Very Long Baseline Array) radio emission at 15GHz, extended emission at 151MHz, and optical nuclear emission at 5100{AA} for a complete sample of 135 compact jets. We use the partial Kendall's tau correlation analysis to check the link between radio properties of parsec-scale jets and optical nuclear luminosities of host active galactic nuclei (AGN). Cone search capability for table J/A+A/520/A62/table3 (Optical and radio parameters of 135 AGN)
Micro-Raman study of red decorations in French faiences of the 18th and 19th centuries
2006
Obtaining the red color was a technical and economic challenge for the French faience manufactories in the 18th and 19th centuries. The tendency of the red hematite to turn into drab brown during the firing process explains the difficulty in obtaining this color. Red decorations in shards coming from the four production centers of faience manufacturing during this period—Rouen (northwest), Nevers (central), Thiviers (southwest) and Argonne (northeast)—have been studied by means of micro-Raman spectroscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Among them, Thiviers appears to be the leader thanks to a particular reddish sandstone called ‘Gres de T…
Dynamics of Metal Centers Monitored by Nuclear Inelastic Scattering
2005
Nuclear inelastic scattering of synchrotron radiation has been used now since 10 years as a tool for vibrational spectroscopy. This method has turned out especially useful in case of large molecules that contain a M\"ossbauer active metal center. Recent applications to iron-sulfur proteins, to iron(II) spin crossover complexes and to tin-DNA complexes are discussed. Special emphasis is given to the combination of nuclear inelastic scattering and density functional calculations.
Sensitivity of jet quenching to enhancement of the medium opacity near TC
2014
[Introduction] One of the main goals of the study of high transverse momentum ( P T ) observables in the context of ultrarelativistic heavy-ion collisions is the determination of properties of QCD matter. In particular, the transport coefficients ˆ q and ˆ e characterizing the interaction of the medium with a high p T parton are accessible via hard probes. However, a precision extraction of their temperature dependence from current data faces the problem that neither the space-time geometry of the evolving matter nor the link between thermodynamics and transport coefficients is unambiguously known. Thus, various conjectured scenarios exist for how thermodynamics and transport coefficients b…
Rapid self-healing and anion selectivity in metallosupramolecular gels assisted by fluorine-fluorine interactions.
2017
Simple ML2 [M = Fe(II), Co(II), Ni(II)] complexes obtained from a perfluoroalkylamide derivative of 4-aminophenyl-2,2′,6,2′-terpyridine spontaneously, yet anion selectively, self-assemble into gels, which manifest an unprecedented rapid gel strength recovery, viz. self-healing, and thermal rearrangement in aqueous dimethyl sulfoxide. The key factor for gelation and rheological properties emerges from the fluorine–fluorine interactions between the perfluorinated chains, as the corresponding hydrocarbon derivative did not form metallogels. The perfluoro-terpyridine ligand alone formed single crystals, while its Fe(II), Co(II) or Ni(II) complexes underwent rapid gelation leading to highly enta…
Transnationalisation and Nordic higher education - Tensions and possibilities in educational policy
2014
The recent developments in Nordic higher education policy are closely linked with global tendencies, which are in turn reacted to at national and local levels. The financial crisis, massification of higher education, and the attachment to transnational, mainly European policies have set the background for new tendencies in education governance. New governance patterns are the outcome of transnational pressures, which are domesticated at the national level. Thus, these transnational tendencies are (re‐)constructed for different transnational, national and local purposes. This thematic issue analyses how the Nordic countries have reacted to these tendencies, tensions and possibilities. nonPee…
English is ‘the language everybody shares’ but it is ‘my native language’ : language ideologies and interpersonal relationships among students in int…
2023
Tässä artikkelissa tarkastellaan eri kieli-ideologioiden—eli arkisten kieltä ja sen puhujia koskevien uskomusten—rooleja opiskelijoiden identiteetin rakentamisessa ja neuvotteluissa kansainvälistyvän korkeakoulutuksen kontekstissa. Englanninkielisten opiskelijoiden lisääntyvän monimuotoisuuden myötä kieli-ideologioita on tutkittu mahdollisena opiskelijoiden välisen epätasa-arvon rakentajana. Analysoin kahta fokusryhmäkeskustelua, joiden osallistujat ovat erään suomalaisen yliopiston kansainvälisten englanninkielisten maisteriohjelmien opiskelijoita. Tutkin opiskelijoiden puhetta kriittisen diskursiivisen psykologian avulla tarkoituksenani ymmärtää mahdollisia yhtymäkohtia kieli-ideologioide…
All polarization-maintaining assively mode-locked yb-doped fiber laser : pulse compression using an anomalous polarization-maintaining photonic cryst…
2019
We report the generation of short pulses at 1 μm using an all-polarization-maintaining (PM) fiber configuration. The pulses are provided by an all normal-dispersion Fabry-Perot Yb-doped cavity and are compressed with an anomalous polarization-maintaining photonic crystal fiber (PM PCF). Opposed to standard configurations; here the filtering action is solely performed by the finite bandwidth of the gain medium. The laser generates 8 ps width sech 2 profile pulses at 1046.8 nm with a −10 dB bandwidth of 5.9 nm. After compression using the PM PCF, pulses with an FWHM of 3 ps were obtained, limited by the actual value of the available anomalous dispersion. We also report the changes in the outp…