Chiral currents in gold nanotubes

Results are presented for the electron current in gold chiral nanotubes (AuNTs). Starting from the band structure of (4,3) and (5,3) AuNTs, we find that the magnitude of the chiral currents are greater than those found in carbon nanotubes. We also calculate the associated magnetic flux inside the tubes and find this to be higher than the case of carbon nanotubes. Although (4,3) and (5,3) AuNTs carry transverse momenta of similar magnitudes, the low-bias magnetic flux carried by the former is far greater than that carried by the latter. This arises because the low-bias longitudinal current carried by a (4,3) AuNT is significantly smaller than that of a (5,3) AuNT.Comment: 5 pages, 6 figure

High-resolution imaging spectroscopy of two micro-pores and an arch filament system in a small emerging-flux region

Aims. The purpose of this investigation is to characterize the temporal evolution of an emerging flux region, the associated photospheric and chromospheric flow fields, and the properties of the accompanying arch filament system. Methods. This study is based on imaging spectroscopy with the G\"ottingen Fabry-P\'erot Interferometer at the Vacuum Tower Telescope, on 2008 August 7. Cloud model (CM) inversions of line scans in the strong chromospheric absorption H$\alpha$ line yielded CM parameters, which describe the cool plasma contained in the arch filament system. Results. The observations cover the decay and convergence of two micro-pores with diameters of less than one arcsecond and provide decay rates for intensity and area. The photospheric horizontal flow speed is suppressed near the two micro-pores indicating that the magnetic field is sufficiently strong to affect the convective energy transport. The micro-pores are accompanied by an arch filament system, where small-scale loops connect two regions with H$\alpha$ line-core brightenings containing an emerging flux region with opposite polarities. The chromospheric velocity of the cloud material is predominantly directed downwards near the footpoints of the loops with velocities of up to 12 km/s, whereas loop tops show upward motions of about 3 km/s. Conclusions. Micro-pores are the smallest magnetic field concentrations leaving a photometric signature in the photosphere. In the observed case, they are accompanied by a miniature arch filament system indicative of newly emerging flux in the form of $\Omega$-loops. Flux emergence and decay take place on a time-scale of about two days, whereas the photometric decay of the micro-pores is much more rapid (a few hours), which is consistent with the incipient submergence of $\Omega$-loops. The results are representative for the smallest emerging flux regions still recognizable as such.Comment: 15 pages, 16 figures, 3 tables, published in A&

Oscillatory combustion in rockets Semiannual report, 1 Jun. - 30 Nov. 1968

Vaporization of droplets near critical poin

Properties of the inner penumbral boundary and temporal evolution of a decaying sunspot

It was empirically determined that the umbra-penumbra boundaries of stable sunspots are characterized by a constant value of the vertical magnetic field. We analyzed the evolution of the photospheric magnetic field properties of a decaying sunspot belonging to NOAA 11277 between August 28 - September 3, 2011. The observations were acquired with the spectropolarimeter on-board of the Hinode satellite. We aim to proof the validity of the constant vertical magnetic-field boundary between the umbra and penumbra in decaying sunspots. A spectral-line inversion technique was used to infer the magnetic field vector from the full-Stokes profiles. In total, eight maps were inverted and the variation of the magnetic properties in time were quantified using linear or quadratic fits. We found a linear decay of the umbral vertical magnetic field, magnetic flux, and area. The penumbra showed a linear increase of the vertical magnetic field and a sharp decay of the magnetic flux. In addition, the penumbral area quadratically decayed. The vertical component of the magnetic field is weaker on the umbra-penumbra boundary of the studied decaying sunspot compared to stable sunspots. Its value seem to be steadily decreasing during the decay phase. Moreover, at any time of the shown sunspot decay, the inner penumbra boundary does not match with a constant value of the vertical magnetic field, contrary to what was seen in stable sunspots. During the decaying phase of the studied sunspot, the umbra does not have a sufficiently strong vertical component of the magnetic field and is thus unstable and prone to be disintegrated by convection or magnetic diffusion. No constant value of the vertical magnetic field was found for the inner penumbral boundary.Comment: Accepted for publication in Astronomy & Astrophysics, 6 pages, 7 figure

Sport as an attempt to socialize youth and women during the Franco regime

En este trabajo se analiza si los diferentes gobiernos que se fueron sucediendo durante las dos primeras décadas del franquismo (1939-1959) utilizaron la actividad físico-deportiva, especialmente entre la juventud y la mujer, para transmitir mejor los mensajes del modelo de sociedad que proponían y conseguir así un mayor número de afines al nacionalsindicalismo. Mediante la revisión documental de fuentes primarias y secundarias se puede concluir que la actividad físico-deportiva no influyó mayoritariamente en las actitudes de sus practicantes, aunque sí que condicionó las posibilidades de practicarlo. El adoctrinamiento y el encuadramiento a través de esta actividad tuvo un escaso éxito, fueron pocos los que acogieron la ideología nacionalsindicalista por practicar actividad física.This paper studies how successive Governments over the first two decades of Francoism (1939-1959) made use of sport and physical activity, especially among youth and women, to best convey the messages of the model of society they sought to achieve and so to increase the number of adherents to the National-Syndicalist system. After detailed analysis of primary and secondary sources, it can be concluded that sport and physical activity did not influence attitudes in most sports people, instead it limited the chances of practising sport. Indoctrination and recruiting through physical activity had a slim success: few were those who embraced the National-Syndicalist ideology by engaging in physical activit

Physical activity and youth in the Franco dictatorship (1937-1961)

El presente artículo analiza las competencias que en materia de actividad física tuvieron diferentes organismos políticos franquistas con respecto a la juventud, especialmente la Delegación Nacional del Frente de Juventudes y la Delegación Nacional de Deportes. Mediante la revisión de la documentación oficial de la época y la aportación de estudios ya realizados sobre la temática, se descubren los puntos de unión y de fricción que existieron entre ambas instituciones. Mientras que ambas Delegaciones priorizaron la actividad físico-deportiva como instrumento para el adoctrinamiento y la adhesión al régimen, sin embargo, fue el Frente de Juventudes el que más lo intentó. Sus instructores e instructoras se filtraron en el sistema educativo y promovieron las actividades extraescolares, especialmente los Juegos Escolares y las actividades de aire libre, aunque realizadas con un marcado sesgo de género y de selección de los más aptos durante las dos primeras décadas del franquismo.This article analyzes the competences that different nationalist political organisations had in the field of physical activity had with regard to youth, particularly the “Delegación Nacional del Frente de Juventudes” and the “Delegación Nacional de Deportes”. Through the revision of the official documentation of the era and the contribution of studies already carried out on the subject, we try to show some common aspects and friction points that existed between the two institutions. While both delegations prioritized sport and physical activity as a tool for the indoctrination and adherence to the regime, however, the “Frente de Juventudes” tried it harder. Their instructors infiltrated into the educational system and promoted after-school activities, especially school games and outdoor activities, which both attracted attention among schoolchildren during the first two decades of Franco Era

La educación física femenina y el ideal de mujer en la etapa franquista

El presente trabajo trata de exponer la situación que la mujer tuvo durante el franquismo y reflexionar sobre los conceptos y valores que se la asignaban desde diferentes campos ( político, laboral, cultural, religioso¿), que la condicionaron en su devenir a lo largo de esos años (1939-1975). La creación de Sección Femenina (S.F.) fomentó, en muchas ocasiones, un ideal de mujer a través de su objetivo fundamental: formarla integralmente; en otras ocasiones luchó por hacer caer convencionalismos asentados en la población, como los relacionados al campo de la Educación Física (E.F.) y el deporte; con la intención de que se conociera esta disciplina entre toda la población. De esta manera se creó un modelo exclusivo para este sexo (Educación Física Femenina- E.F.F.-), condicionado por supuestos científico-médicos y religiosos

Oscillatory combustion in rockets Third semiannual report, Jun. 1 - Nov. 30, 1965

Rocket engine oscillatory combustion studie