Asymmetries of the Stokes V profiles observed by HINODE SOT/SP in the quiet Sun

We present the first classification of SOT/SP circular polarization measurements with the aim of highlighting exhaustively the whole variety of Stokes V shapes emerging from the quiet Sun. k-means is used to classify HINODE SOT/SP Stokes V profiles observed in the quiet Sun network and internetwork (IN). We analyze a 302 x 162 square arcsec field-of-view (FOV) which can be considered a complete sample of quiet Sun measurements performed at at the disk center with 0.32 arcsec angular resolution and 0.001 polarimetric sensitivity. Such a classification allows us to divide the whole dataset in classes, with each class represented by a cluster profile, i.e., the average of the profiles in the class. The set of 35 cluster profiles derived from the analysis completely characterizes SOT/SP quiet Sun measurements. The separation between network and IN profile shapes is evident - classes in the network are not present in the IN, and vice versa. Asymmetric profiles are approximatively 93 % of the total number of profiles. Among these, approximatively 34 % of the profiles are strongly asymmetric profiles, and they can be divided in three families: blue-lobe, red-lobe, and Q-like profiles. The blue-lobe profiles tend to be associated with upflows (granules), whereas the red-lobe and Q-like ones appear in downflows (intergranular lanes). Such profiles need to be interpreted considering model atmospheres different from a uniformly magnetized Milne-Eddington (ME) atmosphere, i.e., characterized by gradients and/or discontinuities in the magnetic field and velocity along the line-of-sight (LOS).Comment: 11 pages, 4 figures, accepted for publication in Astronomy and Astrophysic

Interpretation of HINODE SOT/SP asymmetric Stokes profiles observed in quiet Sun network and internetwork

We present the first interpretation of the Stokes profile asymmetries measured in the FeI 630 nm lines by SOT/SP, in both quiet Sun internetwork (IN) and network regions. The inversion is carried out under the hypothesis of MISMA, where the unresolved structure is assumed to be optically thin. We analyze a 29.52"x31.70" subfield carefully selected to be representative of the properties of a 302"x162" quiet Sun field-of-view at disk center. The inversion code is able to reproduce the observed asymmetries in a very satisfactory way. The inversion code interprets 25% of inverted profiles as emerging from pixels in which both positive and negative polarities coexist. kG field strengths are found at the base of the photosphere in both network and IN; in the case of the latter, both kG fields and hG fields are admixed. When considering the magnetic properties at the mid photosphere most kG fields are gone, and the statistics is dominated by hG fields. We constrain the magnetic field of only 4.5% of the analyzed photosphere (and this percentage reduces to 1.3% when referred to all pixels, including those with low polarization not analyzed). The rest of the plasma is consistent with the presence of weak fields not contributing to the detected polarization signals. The average flux densities derived in the full subfield and in IN regions are higher than the ones derived from the same dataset by Milne-Eddington inversion. The existence of large asymmetries in SOT/SP polarization profiles is uncovered. These are not negligible in quiet Sun data. The MISMA inversion code reproduces them in a satisfactory way, and provides a statistical description of the magnetized IN and network which partly differs and complements the results obtained so far. From this it follows the importance of having a complete interpretation of the line profile shapes.Comment: 11 pages, 9 figures, 1 table - Accepted for publication on A&

Focus on some aspects of market price trends for tungsten

The contribution deals with prices of tungsten concentrate and ammonium paratungstate (APT) where the latter represents the most common form of tungsten for trading purposes. Taking examples of US and China tungsten markets, this paper demonstrates that the tungsten market price is influenced by many other factors than only those of supply and demand. As based on the past pricing trends for tungsten ore concentrates and also ammonium paratungstate (APT), a two year's tungsten price forecast has been developed. The data published by the Metal Bulletin between January 2002 and June 2015 served the purpose of our future trend forecasting. The forecast took advantage of the programme, @RISK by Palisade Corporation, Ithaca, New York (Industrial Edition, Excel Version 6.3.1). The forecast outcomes acquired by GARCH (Generalized Auto-Regressive Conditional Heteroskedastic Model) implied a modification of the original time series of the APT prices, i.e. exclusion of relatively stable prices of the initial period, and the immediate phase of their temporary growth. In the next step, the forecast for APT prices was obtained by means of applying the model MA (Moving Average Model). The outcome corroborates the theory of the growth and drop pricing cycles, which mechanism also applies to tungsten ore concentrate markets.Web of Science22213512

La indianería catalana: ¿mito o realidad?

En los estudios sobre la industrialización europea, y más concretamente en los dedicados al sector textil algodonero, la manufactura de indianas del siglo XVIII ha ocupado normalmente un capitulo destacado. Vista en unos casos como origen de la industria algodonera moderna y en otros como fase importante de su proceso de desarrollo, ha merecido una cierta atención por parte de los investigadores. Ello ha dado lugar a una historiografia que si en términos generales se puede considerar discreta, tanto por su cantidad como por su calidad, en algunos paises, como Inglaterra, Francia o Suiza, ha alcanzado niveles notables

La Guerra Civil española en la obra de Claude Simón

La participación del Premio Nobel de Literatura Claude Simón en la contienda civil española dejó grabadas en su memoria determinadas secuencias que reproduce en varias de sus novelas. La materia de España no le interesa desde el punto de vista político o social sino desde el punto de vista humano por constituir para él la vivencia de una de las constantes universales que componen el ciclo vital.Claude Simón, who was awarded the Nobel Prize for Literature in 1986, took part in the Spanish Civil War, a fact which impressed in his memory a number of sequences that he reproduced in some of his novéis. The 'matter of Spain' does not concern him politically or socially but from a human point of view: for him it is the experience of a universal component constantly present in our life cycle.La participation du Prix Nobel de Littérature Claude Simón á la confrontation civile espagnole a fait que des sequences déterminées se soient gravees dans sa mémoire, des sequences qu'il a reproduites dans certains romans. La matiére d'Espagne ne l'intéresse pas des un point de vue politique ou social mais humain puisqu'elle qu'elle constitue pour lui la perception d'une des constantes universelles qui composent le cycle vital

De la Compañía de Hilados a la Comisión de Fábricas. El asociacionismo empresarial en Cataluña durante la crisis del Antiguo Régimen (1772-1820)

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