On the steady streaming flow due to high-frequency vibration in nearly inviscid liquid bridges

The steady streaming flow due to vibration in capillary bridges is considered in the limiting case when both the capillary Reynolds number and the non-dimensional vibration frequency (based on the capillary time) are large. An asymptotic model is obtained that provides the streaming flow in the bulk, outside the thin oscillatory boundary layers near the disks and the interface. Numerical integration of this model shows that several symmetric and non-symmetric streaming flow patterns are obtained for varying values of the vibration parameters. As a by-product, the quantitative response of the liquid bridge to high-frequency axial vibrations of the disks is also obtained

Clasicismo, moralismo y decadencia: el magisterio de Augusto Monti en la formación para la poesía de Cesare Pavese

Este trabajo estudia, desde el punto de vista de la historia literaria, el impacto del pensamiento teórico de Augusto Monti en la poesía temprana de Cesare Pavese. Los conceptos de moralismo, clasicismo y de literatura decadente son de vital importancia, como puede verse en los desacuerdos entre ambos intelectuales, y en la obra teórica de Monti. En segundo lugar, esta influencia se remonta al famoso grupo de Turín -la "confraternità" -, a la que pertenecía el propio Pavese. Esta influencia sobre Pavese fue decisiva en su evolución como un artista decadente del "Novecento", en oposición al mundo imbuido de moralismo y antifacismo, como el de Turín en los años 20 y 30.This paper studies, from the point of view of literary history, the impact of Augusto Monti's thinking on Cesare Pavese's early theory of poetry. The concepts of moralism, classicism and decadent literature are of central importance, as may be seen in the disagreements between both intellectuals, and in Monti's theoretical work. Secondly, this influence is traced to the famous group of Turin —the “confraternità”-, to which Pavese himself belonged. This influence on Pavese was decisive in his evolution as a decadent, “Novecento” artist, as opposed to the world imbued with moralism and antifacism, like that of Turin in the 20's and 30's.notPeerReviewe

Idealismo y formación croceana en la "Cultura poética" de Césare Pavese

Este estudio tiene por objeto delimitar específicamente el encuentro con el artista piemontés Croce, líder intelectual del Idealismo historicista italiano, durante los años de su formación, que coincidieron algo con el cenit del fascismo. También se examina cómo la influencia del padre de la filosofía italiana sobre el joven poeta, así como sus condiciones, tiene que ser más valorado, a el fin de cuestionar abiertamente el retrato injusto que muchas historias de la literatura han ofrecido de este creador famoso por casi todo, excepto por la solución creativa, que ingenió para impulsar el desarrollo de una cultura literaria en un estado de efervescencia (el Decadentismo italiano y la reacción en contra el mismo).This study is intended to specifically delimit the meeting of the Piemontese artist with Croce, intellectual leader of the Italian Historicist Idealism, during the years of his formation, which coincided whith the zenith of Fascism. It is also defended that the influence of the father of Italian philosophy over the young poet, as well as its conditions, have to be emphasised, in order to openly question the unfair portrait that many Histories of Literature have offered of a creator famous for almost everything, except for this creative solution, which he managed to develop departing from a literary culture in a state of ferment (the Italian Decadentism and the reaction against it).notPeerReviewe

Developing Allometric Equations for Teak Plantations Located in the Coastal Region of Ecuador from Terrestrial Laser Scanning Data

Traditional studies aimed at developing allometric models to estimate dry above-ground biomass (AGB) and other tree-level variables, such as tree stem commercial volume (TSCV) or tree stem volume (TSV), usually involves cutting down the trees. Although this method has low uncertainty, it is quite costly and inefficient since it requires a very time-consuming field work. In order to assist in data collection and processing, remote sensing is allowing the application of non-destructive sampling methods such as that based on terrestrial laser scanning (TLS). In this work, TLS-derived point clouds were used to digitally reconstruct the tree stem of a set of teak trees (Tectona grandis Linn. F.) from 58 circular reference plots of 18 m radius belonging to three different plantations located in the Coastal Region of Ecuador. After manually selecting the appropriate trees from the entire sample, semi-automatic data processing was performed to provide measurements of TSCV and TSV, together with estimates of AGB values at tree level. These observed values were used to develop allometric models, based on diameter at breast height (DBH), total tree height (h), or the metric DBH2 × h, by applying a robust regression method to remove likely outliers. Results showed that the developed allometric models performed reasonably well, especially those based on the metric DBH2 × h, providing low bias estimates and relative RMSE values of 21.60% and 16.41% for TSCV and TSV, respectively. Allometric models only based on tree height were derived from replacing DBH by h in the expression DBH2 x h, according to adjusted expressions depending on DBH classes (ranges of DBH). This finding can facilitate the obtaining of variables such as AGB (carbon stock) and commercial volume of wood over teak plantations in the Coastal Region of Ecuador from only knowing the tree height, constituting a promising method to address large-scale teak plantations monitoring from the canopy height models derived from digital aerial stereophotogrammetry

Rotational Instability of a Long Liquid Column

A liquid column is. apart from its intrinsic interest from the basic science point of view, a good mechanical model of a crystal growth process known as the floating zone technique. In this technique, rotation of the supporting rods is used to uniformize the usually non-axisymmetric temperature field otherwise produced by the directional heating. The theory of the influence of solid rotation on the stability limit is already available and early experimental results showed the existence of two different kinds of unstable shapes (in absence of other perturbations): the amphora mode and the C-mode. The existence of the amphora mode was realized in SL-D1 experiments but C-mode breakages could not be obtained, probably due to unexpected existence of body forces that always excited the amphora mode breakage. As none of these modes can be realistically simulated on Earth, an experiment in microgravity conditions (TEXUS-23) was performed in order to obtain C-mode deformations (not achieved up to now in a reproducible way). However, experiments on Earth using the Plateau Tank Technique have been performed in order to obtain more insight in the problem and to prepare experiments aboard sounding rockets. Results of the experiment aboard TEXUS-23 show a reasonably good agreement with the theoretical predictions

Exergy optimization in a steady moving bed heat exchanger

Proceedings of: Interdisciplinary Transport Phenomena V: Fluid, Thermal, Biological, Materials and Space Sciences (ITP 2007), 14-19 of October, 2007, Bansko, Bulgaria (Oral paper nº 70)This work provides an exergy analysis of a moving bed heat exchanger to obtain for a range of incoming fluid flow rates the operational optimum and the incidence on it of the relevant parameters such as the dimensions of the exchanger, the particle diameter and the flow rate of the fluid. The MBHE proposed can be analyzed as a cross flow heat exchanger where one of the phases is a moving granular medium. In the present work the exergy analysis of the MBHE is carried out over operation data of the exchanger obtained in two ways: a numerical simulation of the steady state problem and the analytical solution of the simplified (avoiding conduction terms) equations. The numerical simulation is carried over the two steady energy equations (fluid and solid), involving for the solid the convection heat transfer to the fluid and the diffusion term in both directions, and for the fluid only the convection heat transfer to the solid. The analytical solution is the wellknown solution of the simplified problem neglecting conduction effects.Publicad

Thermal analysis and optimization of a heat regenerator composed of two coupled moving bed heat exchangers

This work presents a study to optimize the performance of a heat regenerator composed by two coupled moving bed heat exchangers (MBHE). A MBHE is used to recover heat, from a hot gas stream, and the other one is used to preheat an air stream. A direct application might be a gasifier. The heat exchangers performance was studied in two cases, considering or not the conduction heat transfer in the solid phase. When the solid conduction is taken into account, a numerical solution is obtained, while an analytical solution is possible when the conduction terms are neglected. In both cases, the optimum values of bed length (in the air flow direction) and particle diameter were obtained from an exergy point of view. Finally, an energy optimization of the heat regenerator was carried out, obtaining the optimal heat regenerator dimensions as a function of gas velocity and gas flow rate.Publicad

11-M: Apuntes sobre el fracaso de la desinformación o de cómo prevalece la información sobre la convicción

La atribución de la autoría de los atentados del 11-M en Madrid es un ejemplo irrefutable de que no habrá desinformación si los periodistas hacen su trabajo con rigor y contrastan las fuentes, aunque sean del mismo presidente del Gobierno.information is never misleading if journalists do their job correctly and contrast theirs sources, even if one of them is the Prime Minister himself

Graham, Stephen. Cities under siege. The new military urbanism. (Londres: Editorial verso, 2010)

Es reseña de: Graham, Stephen. Cities under siege. The new military urbanism. (Londres: Editorial verso, 2010