Barcellona: osservazioni sulla letteratura riguardante i modelli di indirizzo dell'urbanistica negli ultimi 20 anni

This article proposes a synthetic examination of the modifications that can be found in the official City of Barcelona publications regarding urban transformations in the city in the last 20 years. The main objective is to understand the relationship between urban planning projects and the books published by the city’s various administrations, as well as correspondent urban and social policies. An attempt is made to analyse what has been the programmatic development in light of similar parameters of comparison based on a hypothesis in which the publications, like the projects, have a double role of synthesis with respect to the past and the construction of a collective imaginary on the city regarding the future

Coordenades cromàtiques

Treball de recerca realitzat per una alumna d’ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l’any 2008. L’objectiu d’aquest treball de recerca és estudiar els diferents sistemes de coordenades de colors en mescles additives i subtractives i les seves aplicacions pràctiques en la transmissió i la reproducció d’imatges en color. Primer de tot es va fer una recerca bibliogràfica sobre les característiques elementals de la llum, sobre els trets més importants de l’anatomia de l’ull humà i sobre la corba CIE i l’estudi de les coordenades cromàtiques i les seves aplicacions. D’altra banda, es va confeccionar una maqueta de l’obtenció de la corba CIE, elaborada en metacrilat. S’han complert els objectius previstos amb una exposició sistemàtica i clara dels diferents tipus de coordenades cromàtiques i les seves aplicacions amb exemples originals de l’autora. Amb les aplicacions de mescles additives, s’ha pogut veure la gran importància que tenen les coordenades per a la transmissió i l’emmagatzemament d’imatges. A més a més les coordenades subtractives són de gran utilitat en les impressions. Finalment s’ha pogut veure que, gràcies a les coordenades, es permet la codificació i la transmissió dels colors.

UBVRI photoelectric photometry of nearby stars. II.

A second set of UBVRI photometry results for nearby stars of Gliese's (1969) catalog and its supplements, including in this case some multiple systems, are presented. Most of the observations were carried out between July 1984 and December 1985 at Calar Alto with the 1.23-m Centro Astronomico Hispano-Aleman telescope and the 1.52-m Observatorio Astronomico Nacional telescope. The number of observations of program and standard stars for the six runs and the final results for 60 stars are presented.

uvbyHbeta photometry of main sequence A type stars.

We present Stroemgren uvby and Hbeta_ photometry for a set of 575 northern main sequence A type stars, most of them belonging to the Hipparcos Input Catalogue, with V from 5mag to 10mag and with known radial velocities. These observations enlarge the catalogue we began to compile some years ago to more than 1500 stars. Our catalogue includes kinematic and astrophysical data for each star. Our future goal is to perform an accurate analysis of the kinematical behaviour of these stars in the solar neighbourhood.

UBVRI-CCD photometry of Cepheus OB3 association

Johnson CCD photometry was performed in the two subgroups of the association Cepheus OB3, for selected fields each containing at least one star with previous UBV photoelectric photometry. Photometry for about 1000 stars down to visual magnitude 21 is provided, although the completeness tests show that the sample is complete down to V=19mag. Individual errors were assigned to the magnitude and colours for each star. Colour-colour and colour-magnitude diagrams are shown. Astrometric positions of the stars are also given. Description of the reduction procedure is fully detailed.

An analysis of the currently available calibrations inStromgren photometry by using open clusters

In recent years, several authors have revised the calibrations used to compute physical parameters (tex2html_wrap_inline498, tex2html_wrap_inline500, log g, [Fe/H]) from intrinsic colours in the tex2html_wrap_inline504 photometric system. For reddened stars, these intrinsic colours can be computed through the standard relations among colour indices for each of the regions defined by Strömgren (1966) on the HR diagram. We present a discussion of the coherence of these calibrations for main-sequence stars. Stars from open clusters are used to carry out this analysis. Assuming that individual reddening values and distances should be similar for all the members of a given open cluster, systematic differences among the calibrations used in each of the photometric regions might arise when comparing mean reddening values and distances for the members of each region. To classify the stars into Strömgren's regions we extended the algorithm presented by Figueras et al. (1991) to a wider range of spectral types and luminosity classes. The observational ZAMS are compared with the theoretical ZAMS from stellar evolutionary models, in the range tex2html_wrap_inline506 K. The discrepancies are also discussed.

Photometric Bgr survey of the distant clusters of galaxies CL 1613+3104 and CL 1600+4109

We present a set of photometric data concerning two distant clusters of galaxies: Cl 1613+3104 (z=0.415) and Cl 1600+4109 (z=0.540). The photometric survey extends to a field of about 4' x 3'. It was performed in 3 filters: Johnson B, and Thuan-Gunn g and r. The sample includes 679 objects in the field of Cl 1613+3104 and 334 objects in Cl 1600+4109.

CP2 stars as viewed by the uvby Hbeta system

A new statistical parallax method using the Maximum Likelihood principle is presented, allowing the simultaneous determination of a luminosity calibration, kinematic characteristics and spatial distribution of a given sample. This method has been developed for the exploitation of the Hipparcos data and presents several improvements with respect to the previous ones: the effects of the selection of the sample, the observational errors, the galactic rotation and the interstellar absorption are taken into account as an intrinsic part of the formulation (as opposed to external corrections). Furthermore, the method is able to identify and characterize physically distinct groups in inhomogeneous samples, thus avoiding biases due to unidentified components. Moreover, the implementation used by the authors is based on the extensive use of numerical methods, so avoiding the need for simplification of the equations and thus the bias they could introduce. Several examples of application using simulated samples are presented, to be followed by applications to real samples in forthcoming articles.

Secondary UBVRI-CCD standard stars in the neighbourhood of Landolt standard stars

A list of 681 UBVRI secondary standard stars for CCD photometry is presented. Visual magnitude ranges from 9.7 to 19.4, and the B-V colour index varies from 1.15 to 1.97. The stars are grouped into 11 different fields, each of them is generally observable in a single CCD frame. The stars are located near Landolt UBVRI equatorial standards, accessible to telescopes in both hemispheres, and mainly within the 5 - 8 hours range of right ascension. Photometry, equatorial coordinates and finding charts are provided.

UBVRI photoelectric photometry of nearby stars

In order to complete the photometric data of the Gliese (1969) 'Catalog of Nearby Stars', and in addition use these data for the Hipparcos space astrometry mission, program stars have been selected from the catalog and its supplements on the basis of their having an incomplete set of UBVRI photometric data of magnitude lower than 13. The program developed rejects determinations of any magnitude or color index having a residual greater than 2(sigma-prime), where sigma-prime is the standard deviation for the determinations of unit weight.

UBVRI photoelectric photometry of high proper motion stars

UBVRI photoelectric photometry is presented for 269 late spectral type, high proper motion stars belonging to the 'Lowell Proper Motion Survey' and included in the present version of the Hipparcos Input Catalogue. The observations and data reduction are described. The external errors obtained by comparison of the results with those obtained in other studies are presented.

UBVRI photometry of G, K, M Hipparcos stars

UBVRI data are presented for a set of 229 late-type stars, most of them being high proper motion stars. All these data are part of the Input Catalog planned observations for the Hipparcos mission.

UVBY-Beta Photometry for 67 Stars in the Region of Alpha-Persei

UVBY-Beta photometric data are presented for 67 stars in the region of alpha-Persei and their relationship to the cluster is analyzed. These data allowed us to confirm at least 16 new members of the alpha-Persei open cluster.

Photometric and Spectroscopic Observations of the Cluster of Galaxies Abell 2390

Spectroscopic and photometric observations in a 6 arcmin x 6 arcmin field centered on the rich cluster of galaxies Abell 2390 are presented. The photometry concerns 700 objects and the spectroscopy 72 objects. The redshift survey shows that the mean redshift of the cluster is 0.232. An original method for automatic determination of the spectral type of galaxies is presented.