Evaluación de los suelos de la comarca del Aljarafe

58 páginas, 6 cuadros, 27 referencias.-- 1 mapa de suelos.-- Memoria final presentada al XXIV Curso Internacional de Edafología y Biología Vegetal, patrocinado por UNESCO-AECI y CSIC que desde 1963 hasta 2009 se ha impartido en el Centro de Edafología y Biología Aplicada del Cuarto (CEBAC), que desde 1987 pasó a denominarse Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC).-- Existe un ejemplar de la publicación en la Biblioteca del Instituto de Recursos Naturales y Agrobiología de Sevilla-CSIC, para su consulta.Director del trabajo: Mudarra Gómez, José LuisEste trabajo se refiere a la caracterización, cartografía y evaluación de los suelos de la comarca de El Aljarafe (Sevilla). La fase de caracterización y cartografía fue realizada en los años 1983 y 1984 por la Unidad Estructural de Investigación de Cartografía y Evaluación de Suelos del Centro de Edafología y Biología Aplicada del Cuarto, que dirige el Dr. D. José Luis Mudarra Gómez, con la colaboración del Ayudante de Investigación D. Antonio Rosales Sánchez y los alumnos del XX y XXI Curso Internacional de Edafología.El presente informe corresponde a la continuación de un trabajo que se ha venido realizando desde años anteriores y dentro del programa de investigación denominado "Estudio de las condiciones de fertilidad de los suelos españoles de mayor interés agrícola" del Consejo Superior de Investigaciones Científicas. Proyecto 2252.01.Peer reviewe

Analysis of the quark sector in the 2HDM-III with a four-zero Yukawa texture using the most recent data on the CKM matrix

In this letter we analyse, in the context of the general 2-Higgs Doublet Model, the structure of the Yukawa matrices, $\widetilde{ \bf Y}_{ _{1,2} }^{q}$, by assuming a four-zero texture ansatz for their definition. In this framework, we obtain compact expressions for $\widetilde{ \bf Y}_{ _{1,2} }^{q}$, which are reduced to the Cheng and Sher ansatz with the difference that they are obtained naturally as a direct consequence of the invariants of the fermion mass matrices. Furthermore, in order to avoid large flavour violating effects coming from charged Higgs exchange, we consider the main flavour constraints on the off-diagonal terms of Yukawa texture {{$\left( \widetilde{\chi}_{j}^q \right)_{kl}$}} ($k\neq l$). We perform a $\chi^2$-fit based on current experimental data on the quark masses and the Cabibbo-Kobayashi-Maskawa mixing matrix ${ \bf V}_{\rm CKM }$. Hence, we obtain the allowed ranges for the parameters $\widetilde{ \bf Y}_{ _{1,2} }^{q}$ at 1$\sigma$ for several values of $\tan \beta$. The results are in complete agreement with the bounds obtained taking into account constraints on Flavour Changing Neutral Currents reported in the literature.Comment: 12 pages, 1 figure. Version accepted in Phys. Lett.

Ultrafast spin polarization control of Dirac fermions in topological insulators

Three-dimensional topological insulators (TIs) are characterized by spin-polarized Dirac-cone surface states that are protected from backscattering by time-reversal symmetry. Control of the spin polarization of topological surface states (TSSs) using femtosecond light pulses opens novel perspectives for the generation and manipulation of dissipationless surface spin currents on ultrafast timescales. Using time-, spin-, and angle-resolved spectroscopy, we directly monitor for the first time the ultrafast response of the spin polarization of photoexcited TSSs to circularly-polarized femtosecond pulses of infrared light. We achieve all-optical switching of the transient out-of-plane spin polarization, which relaxes in about 1.2 ps. Our observations establish the feasibility of ultrafast optical control of spin-polarized Dirac fermions in TIs and pave the way for novel optospintronic applications at ultimate speeds.Comment: 9 pages, 4 figure

Quantum tomography via equidistant states

We study the possibility of performing quantum state tomography via equidistant states. This class of states allows us to propose a non-symmetric informationally complete POVM based tomographic scheme. The scheme is defined for odd dimensions and involves an inversion which can be analytically carried out by Fourier transform

Limb imaging of the Venus O2 visible nightglow with the Venus Monitoring Camera

We investigated the Venus O2 visible nightglow with imagery from the Venus Monitoring Camera on Venus Express. Drawing from data collected between April 2007 and January 2011, we study the global distribution of this emission, discovered in the late 70s by the Venera 9 and 10 missions. The inferred limb-viewing intensities are on the order of 150 kiloRayleighs at the lower latitudes and seem to drop somewhat towards the poles. The emission is generally stable, although there are episodes when the intensities rise up to 500 kR. We compare a set of Venus Monitoring Camera observations with coincident measurements of the O2 nightglow at 1.27 {\mu}m made with the Visible and Infrared Thermal Imaging Spectrometer, also on Venus Express. From the evidence gathered in this and past works, we suggest a direct correlation between the instantaneous emissions from the two O2 nightglow systems. Possible implications regarding the uncertain origin of the atomic oxygen green line at 557.7 nm are noted.Comment: 7 pages, 3 figure