3,808 research outputs found

    Discriminant analysis of solar bright points and faculae II. Contrast and morphology analysis

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    Taken at a high spatial resolution of 0.1 arcsec, Bright Points (BPs) are found to coexist with faculae in images and the latter are often resolved as adjacent striations. Understanding the properties of these different features is fundamental to carrying out proxy magnetometry. To shed light on the relationship between BPs and faculae, we studied them separately after the application of a classification method, developed and described in a previous paper) on active region images at various heliocentric angles. In this Paper, we explore different aspects of the photometric properties of BPs and faculae, namely their G-band contrast profiles, their peak contrast in G-band and continuum, as well as morphological parameters. We find that: (1) the width of the contrast profiles of the classified BPs and faculae are consistent with studies of disk center BPs at and limb faculae, which indirectly confirms the validity of our classification, (2) the profiles of limb faculae are limbward skewed on average, while near disk center they exhibit both centerward and limbward skewnesses due to the distribution of orientations of the faculae, (3) the relation between the peak contrasts of BPs and faculae and their apparent area discloses a trend reminiscent of magnetogram studies. The skewness of facular profiles provides a novel constraint for 3D MHD models of faculae. As suggested by the asymmetry and orientation of their contrast profiles, faculae near disk center could be induced by inclined fields, while apparent BPs near the limb seem to be in fact small faculae misidentified. The apparent area of BPs and faculae could be possibly exploited for proxy magnetometry

    Politique fédérale des agglomérations dans les domaines des transports et de l'urbanisation

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    La croissance de la population, de l'économie et des transports individuels motorisés, particulièrement depuis la seconde moitié du 20ème siècle, ont notamment comme corollaire le développement urbanistique hors des frontières de la ville-centre et la formation des agglomérations. Ces zones urbaines sont stratégiques puisqu'elles accueillent une part toujours plus importante de la population et représentent le moteur de l'économie nationale. Toutefois, le développement des agglomérations et de la mobilité individuelle motorisée ne va pas sans poser de nombreux problèmes, dont la résolution nécessite de les aborder à l'échelle de l'agglomération, en coordonnant les transports et l'urbanisation. Notre système politique fédéral se définit notamment par une répartition des compétences dans une multitude de domaines entre les trois niveaux institutionnels de la Confédération, des cantons et des communes. Cette réalité est particulièrement vraie en matière d'aménagement du territoire. Il est à noter que les plus petites unités institutionnelles (les communes) conservent encore aujourd'hui des prérogatives importantes dans ce domaine. Au début des années 2000, la Confédération a développé une politique publique en faveur de ces zones stratégiques. Au moyen du fonds d'infrastructure, la politique fédérale des agglomérations dans les domaines des transports et de l'urbanisation est une politique publique incitative. Le dépôt, par les agglomérations, d'un projet respectant un cahier des charges précis et proposant des mesures de coordination entre les transports et l'urbanisation, permet d'obtenir un cofinancement fédéral du transport d'agglomération. Parmi les projets d'agglomération de première génération présentés à la Confédération, certains ont obtenu le cofinancement, d'autres pas. Le dimensionnement trop généreux des surfaces à bâtir fut notamment un facteur d'échec du projet d'agglomération de Fribourg, alors que la capacité à développer l'urbanisation à l'intérieur de l'agglomération fut un facteur de succès du projet Lausanne-Morges. L'analyse des projets d'agglomération Riviera et Monthey-Aigle, qui sont des projets de deuxième génération, confrontée à des entretiens avec des urbanistes et des responsables politiques, permet d'identifier leurs faiblesses et leurs atouts. Le projet d'agglomération Riviera présente une complémentarité des territoires et un grand potentiel de développement, mais aussi un manque de cohésion des partenaires du projet. Quant au projet Monthey-Aigle, il existe une réelle volonté politique de trouver des solutions aux conflits, mais les possibilités de développer les transports publics sont faibles. Dans le cadre de l'examen fédéral de ces deux projets d'agglomération, les éléments précités pourraient être des facteurs d'échec ou de succès. La politique publique fédérale invite les agglomérations à penser le développement de leurs transports et de leur urbanisation à un niveau global. La prise de hauteur et la coordination politique que cela suppose sont à même d'améliorer le lieu de vie des trois-quarts de la population suisse et de préserver le moteur de l'économie nationale. The growth of population, economy and personal motorised transportation, most particularly since the second half of the 20th century, has, as a consequence, induced an expansion of urban areas outside the borders of cities and encouraged the formation of urban agglomerations. These urban zones are of strategic importance as they attract an increasingly large population and represent a real driver of the national economy. However, the development of these agglomerations and the motorised mobility of their inhabitants cause numerous problems which require solutions to be adopted at the level of the agglomeration involving the interconnection of transport and urbanisation. Our federal political system is characterised by a distribution of responsibilities in many domains among the three institutional levels, namely the Confederation, the cantons and the communes. This is particularly the case of territorial developments. It should be noted that the smallest institutional units, the communes, still hold today important responsibilities in this area. At the beginning of the years 2000, the Confederation has developed a public policy in favour of these strategic zones. Through the establishment of an infrastructure fund, the federal policy in favour of urban agglomerations in the areas of transport and urbanisation aims at providing incentives to agglomerations. The submission by the agglomeration of a project containing a clear description of tasks and measures to integrate transport and urbanisation can result in a cofinancing participation by the Confederation in this project. Among the projects of first generation which had been submitted to the Confederation, some have received the cofinancing, others have not. The too generous dimension of the building areas in the project submitted by the agglomeration of Fribourg was a factor of its failure, while the capacity to develop urbanisation within the agglomeration was a factor of success for the Lausanne-Morges project. The analysis of the projects of the agglomerations Riviera and Monthey-Aigle which are projects of the second generation, as well as the interviews of urbanists and concerned officials have allowed us to identify their strengths and weaknesses. The Riviera project provides a complementary approach and a high potential of territorial developments, but at the same time denotes a lack of cohesion among partners of the project. With respect to the project Monthey-Aigle, there is a real political willingness to resolve conflicts, but the potential for the development of public transports is small. In the consideration by the Confederation of these two projects, the factors mentioned above may bring success or failure. The federal public policy incites the agglomerations to conceive the development of their transportation and urbanisation plans at a global level. The elevation of interests and the political coordination that this requires can improve the place of living of ¾ of the Swiss population and preserve the engine of growth of the national economy

    CEEX Exponentiation in QED

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    The aim is to summarize briefly on: (a) Main features of YFS Cohenetn Exclusive EXponentiation in QED, (b) Examples of recent results relevant for LEP/LC physics program.Comment: ICHEP 2002 tal

    Surprises from Quarkonium Decay into Photons

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    The perturbative QCD approach to quarkonium decay into a photon and hadrons is reconsidered. It is shown that a consistent treatment within perturbative QCD calls for the introduction of a fragmentation contribution which has been neglected so far. The ensuing phenomenological implications are discussed, and, in particular, the possibility of measuring the gluon fragmentation function of the photon is addressed. *To appear in the proceedings of the workshop QCD94, Montpellier, July '94.Comment: 4 pages + 3 figures, uuencoded postscript, Cambridge preprint Cavendish-HEP-94/0

    A psychometric analysis of the Caring Assessment Tool version V

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    Aim The aim of this study was to examine the factor structure and construct validity of the Caring Assessment Tool version V (CAT‐V) for patients in Australian hospitals. Design Secondary analysis of CAT‐V surveys from the Australian Nursing Outcomes Collaborative (AUSNOC) data set was used. The CAT was originally developed in the United States of America. Methods The 27‐item CAT‐V was administered to patients prior to discharge from eight wards in three Australian hospitals in 2016. The psychometric properties of the CAT were evaluated using item analysis and exploratory factor analyses. Results Item analysis of surveys from 476 participants showed high levels of perceived caring behaviours and actions. Exploratory factor analysis revealed a two‐factor structure consisting of: Nurse-patient communication; and Feeling cared for. The CAT‐V is a reliable and valid instrument for measuring patients\u27 perceptions of the attitudes and actions of nurses in Australia

    Evidence of convective rolls in a sunspot penumbra

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    aims: We study the recently discovered twisting motion of bright penumbral filaments with the aim of constraining their geometry and the associated magnetic field. methods: A large sunspot located 40\degr from disk center was observed at high resolution with the 1-m Swedish Solar Telescope. Inversions of multi-wavelength polarimetric data and speckle reconstructed time series of continuum images were used to determine proper motions, as well as the velocity and magnetic structure in penumbral filaments. results: The continuum movie reveals apparent lateral motions of bright and dark structures inside bright filaments oriented parallel to the limb, confirming recent Hinode results. In these filaments we measure upflows of 1.1km/s\approx 1.1 \mathrm{km/s} on their limbward side and weak downflows on their centerward side. The magnetic field in them is significantly weaker and more horizontal than in the adjacent dark filaments. conclusions: The data indicate the presence of vigorous convective rolls in filaments with a nearly horizontal magnetic field. These are separated by filaments harbouring stronger, more vertical fields. Because of reduced gas pressure, we see deeper into the latter. When observed near the limb, the disk-centerward side of the horizontal-field filaments appear bright due to the \textit{hot wall} effect known from faculae. We estimate that the convective rolls transport most of the energy needed to explain the penumbral radiative flux.Comment: 4 pages, 4 figures, letter to Astronomy & Astrophysic

    The continuum intensity as a function of magnetic field I. Active region and quiet Sun magnetic elements

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    Small-scale magnetic fields are major contributors to the solar irradiance variations. Hence, the continuum intensity contrast of magnetic elements in the quiet Sun (QS) network and in active region (AR) plage is an essential quantity that needs to be measured reliably. By using Hinode/SP disk center data at a constant, high spatial resolution, we aim at updating results of earlier ground-based studies of contrast vs. magnetogram signal, and to look for systematic differences between AR plages and QS network. The field strength, filling factor and inclination of the field was retrieved by Milne-Eddington inversion (VFISV). As in earlier studies, we performed a pixel-by-pixel study of 630.2 nm continuum contrast vs. apparent (i.e. averaged over a pixel) longitudinal magnetic field over large fields of view in ARs and in the QS. The contrast of magnetic elements reaches larger values in the QS (on average 3.7%) than in ARs (1.3%). This could not be attributed to any systematic difference in the chosen contrast references. At Hinode's spatial resolution, the relationship between contrast and apparent longitudinal field strength exhibits a peak at around 700 G in both the QS and ARs, whereas earlier lower resolution studies only found a peak in the QS and a monotonous decrease in ARs. We attribute this discrepancy both to our careful removal of the pores and their close surroundings affected by the telescope diffraction, as well as to the enhanced spatial resolution and very low scattered light of the Hinode Solar Optical Telescope. According to our inversions, the magnetic elements producing the peak of the contrast curves have similar properties (field strength, inclination, filling factor) in ARs and in the QS, so that the larger brightness of magnetic elements in the QS remains unexplained.Comment: 8 figures, 14 page

    Two-Fermion Production in Electron-Positron Collisions

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    This report summarizes the results of the two-fermion working group of the LEP2-MC workshop, held at CERN from 1999 to 2000. Recent developments in the theoretical calculations of the two fermion production process in the electron-positron collision at LEP2 center of the mass energies are reported. The Bhabha process and the production of muon, tau, neutrino and quark pairs is covered. On the basis of comparison of various calculations, theoretical uncertainties are estimated and compared with those needed for the final LEP2 data analysis. The subjects for the further studies are identified.Comment: 2-fermion working group report of the LEP2 Monte Carlo Workshop 1999/2000, 113 pages, 24 figures, 35 table

    Report on Running Channels in iseg 32-Ch HV Power Supplies

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    We report a study and solution of the so-called "running channel" (RC) phenomenon observed in the iseg 32-channel HV power supplies for the ATLAS Liquid Argon Calorimetry
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