Roberto C. Manteiga, Carolyn Galerstein and Kathleen McNerney, eds: Feminine Concerns in Contemporary Spanish Fiction by Women

Review of: Cecilia Belchi Arévalo y María Martínez del Portal. eds. Estudios sobre José Luis Castillo-Puche, Murcia, Academia Alfonso X El Sabio, 1988, 165 pp

Endohedral terthiophene in zigzag carbon nanotubes: Density functional calculations

The inclusion and encapsulation of terthiophene (T3) molecules inside zigzag single-walled carbon nanotubes (CNTs) is addressed by density functional calculations. We consider the T3 molecule inside five semiconducting CNTs with diameters ranging from 9.6 to 12.7 Ang. Our results show that the T3 inclusion process is exothermic for CNTs with diameters larger than 9.5 Ang. The highest energy gain is found to be of 2 eV, decreasing as the CNT diameter increases. This notable effect of stabilization is attributed to the positively charged CNT inner space, as induced by its curvature, which is able to accommodate the neutral T3 molecule. The band structure of the T3@CNT system shows that T3 preserves its electronic identity inside the CNTs, superimposing their molecular orbitals onto the empty CNT band structure without hybridization. Our results predict that the electronic states added by the T3 molecules would give rise to optical effects and nonradiative relaxation from excited states.Comment: 5 pages, 5 figures, 1 table, accepted in PR

Quasinormal modes and Stability Analysis for 4-dimensional Lifshitz Black Hole

We study the Lifshitz black hole in 4-dimensions with dynamical exponent z=2 and we calculate analytically the quasinormal modes of scalar perturbations. These quasinormal modes allows to study the stability of the Lifshitz black hole and we have obtained that Lifshitz black hole is stable.Comment: 7 pages, 2 figures. arXiv admin note: text overlap with arXiv:1205.058

The relationship of telomere length to baseline corticosterone levels in nestlings of an altricial passerine bird in natural populations.

BackgroundEnvironmental stressors increase the secretion of glucocorticoids that in turn can shorten telomeres via oxidative damage. Modification of telomere length, as a result of adversity faced early in life, can modify an individual's phenotype. Studies in captivity have suggested a relationship between glucocorticoids and telomere length in developing individuals, however less is known about that relationship in natural populations.MethodsIn order to evaluate the effect of early environmental stressors on telomere length in natural populations, we compared baseline corticosterone (CORT) levels and telomere length in nestlings of the same age. We collected blood samples for hormone assay and telomere determination from two geographically distinct populations of the Thorn-tailed Rayadito (Aphrastura spinicauda) that differed in brood size; nestlings body mass and primary productivity. Within each population we used path analysis to evaluate the relationship between brood size, body mass, baseline CORT and telomere length.ResultsWithin each distinct population, path coefficients showed a positive relationship between brood size and baseline CORT and a strong and negative correlation between baseline CORT and telomere length. In general, nestlings that presented higher baseline CORT levels tended to present shorter telomeres. When comparing populations it was the low latitude population that presented higher levels of baseline CORT and shorter telomere length.ConclusionsTaken together our results reveal the importance of the condition experienced early in life in affecting telomere length, and the relevance of integrative studies carried out in natural conditions

Lensing by Kerr Black Holes. II: Analytical Study of Quasi-Equatorial Lensing Observables

In this second paper, we develop an analytical theory of quasi-equatorial lensing by Kerr black holes. In this setting we solve perturbatively our general lens equation with displacement given in Paper I, going beyond weak-deflection Kerr lensing to third order in our expansion parameter epsilon, which is the ratio of the angular gravitational radius to the angular Einstein radius. We obtain new formulas and results for the bending angle, image positions, image magnifications, total unsigned magnification, and centroid, all to third order in epsilon and including the displacement. New results on the time delay between images are also given to second order in epsilon, again including displacement. For all lensing observables we show that the displacement begins to appear only at second order in epsilon. When there is no spin, we obtain new results on the lensing observables for Schwarzschild lensing with displacement.Comment: 23 pages; final published versio

Homogeneous metallicities and radial velocities for Galactic globular clusters. II. New CaT metallicities for 28 distant and reddened globular clusters

Although the globular clusters in the Milky Way have been studied for a long time, a significant fraction of them lack homogeneous metallicity and radial velocity measurements. In an earlier paper we presented the first part of a project to obtain metallicities and radial velocities of Galactic globular clusters from multiobject spectroscopy of their member stars using the ESO Very Large Telescope. In this paper we add metallicities and radial velocities for a new sample of 28 globular clusters, including in particular globular clusters in the MW halo and the Galactic bulge. Together with our previous results, this study brings the number of globular clusters with homogeneous measurements to $\sim 69$ \% of those listed in the W. Harris' catalogue. As in our previous work, we have used the CaII triplet lines to derive metallicities and radial velocities. For most of the clusters in this study, this is the first analysis based on spectroscopy of individual member stars. The metallicities derived from the CaII triplet are then compared to the results of our parallel study based on spectral fitting in the optical region and the implications for different calibrations of the CaII triplet line strengths are discussed. We also comment on some interesting clusters and investigate the presence of an abundance spread in the globular clusters here. A hint of a possible intrinsic spread is found for NGC 6256, which therefore appears to be a good candidate for further study.Comment: 13 pages, 9 figures, accepted for publication in Astronomy and Astrophysic

High resolution spectroscopic analysis of seven giants in the bulge globular cluster NGC 6723

Globular clusters associated with the Galactic bulge are important tracers of stellar populations in the inner Galaxy. High resolution analysis of stars in these clusters allows us to characterize them in terms of kinematics, metallicity, and individual abundances, and to compare these fingerprints with those characterizing field populations. We present iron and element ratios for seven red giant stars in the globular cluster NGC~6723, based on high resolution spectroscopy. High resolution spectra ($R\sim48~000$) of seven K giants belonging to NGC 6723 were obtained with the FEROS spectrograph at the MPG/ESO 2.2m telescope. Photospheric parameters were derived from $\sim130$ FeI and FeII transitions. Abundance ratios were obtained from line-to-line spectrum synthesis calculations on clean selected features. An intermediate metallicity of [Fe/H]$=-0.98\pm0.08$ dex and a heliocentric radial velocity of $v_{hel}=-96.6\pm1.3~km s^{-1}$ were found for NGC 6723. Alpha-element abundances present enhancements of $[O/Fe]=0.29\pm0.18$ dex, $[Mg/Fe]=0.23\pm0.10$ dex, $[Si/Fe]=0.36\pm0.05$ dex, and $[Ca/Fe]=0.30\pm0.07$ dex. Similar overabundance is found for the iron-peak Ti with $[Ti/Fe]=0.24\pm0.09$ dex. Odd-Z elements Na and Al present abundances of $[Na/Fe]=0.00\pm0.21$ dex and $[Al/Fe]=0.31\pm0.21$ dex, respectively. Finally, the s-element Ba is also enhanced by $[Ba/Fe]=0.22\pm0.21$ dex. The enhancement levels of NGC 6723 are comparable to those of other metal-intermediate bulge globular clusters. In turn, these enhancement levels are compatible with the abundance profiles displayed by bulge field stars at that metallicity. This hints at a possible similar chemical evolution with globular clusters and the metal-poor of the bulge going through an early prompt chemical enrichment

SPRAY CONE ANGLES GENERATED BY A DUAL CENTRIFUGAL INJECTOR

A dual pressure swirl injector is characterized by two independent concentric chambers which can provide independent rotational levels to a single liquid or two different liquids. This paper compares theoretical, semi-empirical and experimental results concerning the spray cone angles formed by injection of water, ethanol and biodiesel through a dual pressure swirl injector. Data are obtained for injection of the same liquid through the primary and secondary chambers and for injection of ethanol in the primary chamber and biodiesel through the secondary chamber of the injector. Experimental data are obtained using photographic techniques and are analyzed by an image processing software developed in Matlab language