DSpace Colección :
http://hdl.handle.net/20.500.11765/1577
2024-03-28T13:51:44ZA major star formation region in the receding tip of the stellar galactic bar. II. Supplementary information and evidence that the bar is not the same structure as the triaxial bulge previously reported
http://hdl.handle.net/20.500.11765/14263
Título : A major star formation region in the receding tip of the stellar galactic bar. II. Supplementary information and evidence that the bar is not the same structure as the triaxial bulge previously reported
Autor : López Corredoira, Martín; Garzón, F.; Beckman, J. E.; Mahoney, Terence J.; Hammersley, P. L.; Calbet, Xavier
Resumen : This paper is the second part in a series, the Ðrst part of which presented an outline of the analysis of
60 spectra from a follow-up program to the Two Micron Galactic Survey (TGMS) project in the l\ 27¡,
b \ 0¡ area. In this second part, we present a more detailed explanation of the analysis, a library of the
spectra for more complete information for each of the 60 stars, and further discussions on the implications for the structure of the Galaxy. This region contains a prominent excess in the Ñux distribution
and star counts previously observed in several spectral ranges, notably in the TMGS. We found that
over 50% of the spectra of the stars detected with mag, within a very high conÐdence level, mK \ 5.0
correspond to stars of luminosity class I, and a signiÐcant proportion of the remainder are very late
giants that must also be rapidly evolving. We make the case, using all the available evidence, that we are
observing a region at the nearer end of the Galactic bar, where the Scutum spiral arm breaks away, and
that this is powerful evidence for the presence of the bar. Regions of this type can form because of the
concentrations of shocked gas where a galactic bar meets a spiral arm, as is observed at the ends of the
bars of many face-on external galaxies. Alternative explanations do not give nearly such a satisfactory
account of the observations.1999-01-01T00:00:00ZEffective parameters for surface heat fluxes in heterogeneous terrain
http://hdl.handle.net/20.500.11765/14262
Título : Effective parameters for surface heat fluxes in heterogeneous terrain
Autor : Rodríguez Camino, Ernesto; Avissar, Roni
Resumen : The relations between most land-surface characteristics and surface heat fluxes are typicallynon-linear. Because the ground surface is heterogeneous at all scales, it is important to accountfor these non-linear relations. EVective parameters are often applied for that purpose. Steady-state simulations were used in this paper to thoroughly analyse the eVective parameters impactunder a broad range of atmospheric conditions. The eVect of diVerent types of aggregatingfunctions on the accuracy of various eVective parameters is also examined. The authors foundthat linear averaging of leaf area index and soil water content gives higher latent and lowersensible heat fluxes than the corresponding flux averaging over all surface types existing in onesquare grid. Linear averaging of roughness length under unstable conditions provides higherlatent and lower sensible heat fluxes than flux averaging, whereas under stable conditions giveshigher sensible and lower latent heat fluxes. Non-linear functions result to be more useful thanlinear functions to compute the eVective value of those parameters which aVect the surface heatfluxes independently of the atmospheric stability (e.g., leaf area index and soil water content,and unlike roughness length).1999-01-01T00:00:00ZTurbulent Dufour effect and Onsager-type relations
http://hdl.handle.net/20.500.11765/14261
Título : Turbulent Dufour effect and Onsager-type relations
Autor : Sancho Sánchez, Pedro
Resumen : In this paper we extend the work of Elperin et al. [Phys. Rev. Lett. 80, 69 (1998)] by showing that a turbulent Dufour-type effect is also present in chemically nonreacting gaseous admixtures. This result is used to analyze the possibility of obtaining turbulent analogs of the Onsager relations, a fundamental result for molecular crossed effects in irreversible thermodynamics.1999-01-01T00:00:00ZAplicación de una modelización Lagrangiana a la contaminación atmosférica transfronteriza
http://hdl.handle.net/20.500.11765/14260
Título : Aplicación de una modelización Lagrangiana a la contaminación atmosférica transfronteriza
Autor : Rúa, Antonio; Hernández Martín, E.; Gimeno, Luis
Resumen : In this article a physical modelization of the atmospheric pollution was considered. The objective was to determine the concentrations of pollutants in a receptor station reproducing the way followed by the air mass and simulating the physical and chemical processes involved during this way. To do that we used a Lagrangian model.
To estimate the quality of the model a comparision betweeen the theoretical concentration from the model and the observed concentrations is done. the model uses the air mass trajectories arriving at the receptor station calculated from the Limited Area Model (LAM). These trajectories let us know the air mass position each 6 hours. once the initial moedl had been run, several parameters were modified with the aim of reproducing letter the conditions of The Iberian Peninsula. The considered pollutans wer the SO2 and SO42-and the chosen station was Logroño (Spain).1998-01-01T00:00:00Z