Interacting dark sector with variable vacuum energy

We examine a cosmological scenario where dark matter is coupled to a variable vacuum energy while baryons and photons are two decoupled components for a spatially flat Friedmann-Robertson-Walker spacetime. We apply the $\chi^{2}$ method to the updated observational Hubble data for constraining the cosmological parameters and analyze the amount of dark energy in the radiation era. We show that our model fulfills the severe bound of $\Omega_{x}(z\simeq 1100)<0.009$ at the $2\sigma$ level, so it is consistent with the recent analysis that includes cosmic microwave background anisotropy measurements from the Planck survey, the Atacama Cosmology Telescope, and the South Pole Telescope along with the future constraints achievable by the Euclid and CMBPol experiments, and fulfills the stringent bound $\Omega_{x}(z\simeq 10^{10})<0.04$ at the $2\sigma$ level in the big-bang nucleosynthesis epoch.Comment: 5 pages,3 figures, 2 tables. (http://prd.aps.org/abstract/PRD/v88/i8/e087301

Local and average fields inside surface-disordered waveguides: Resonances in the one-dimensional Anderson localization regime

We investigate the one-dimensional propagation of waves in the Anderson localization regime, for a single-mode, surface disordered waveguide. We make use of both an analytical formulation and rigorous numerical simulation calculations. The occurrence of anomalously large transmission coefficients for given realizations and/or frequencies is studied, revealing huge field intensity concentration inside the disordered waveguide. The analytically predicted s-like dependence of the average intensity, being in good agreement with the numerical results for moderately long systems, fails to explain the intensity distribution observed deep in the localized regime. The average contribution to the field intensity from the resonances that are above a threshold transmission coefficient $T_{c}$ is a broad distribution with a large maximum at/near mid-waveguide, depending universally (for given $T_{c}$) on the ratio of the length of the disorder segment to the localization length, $L/\xi$. The same universality is observed in the spatial distribution of the intensity inside typical (non-resonant with respect to the transmission coefficient) realizations, presenting a s-like shape similar to that of the total average intensity for $T_{c}$ close to 1, which decays faster the lower is $T_{c}$. Evidence is given of the self-averaging nature of the random quantity $\log[I(x)]/x\simeq -1/\xi$. Higher-order moments of the intensity are also shown.Comment: 9 pages, 9 figure

Interaction Effects on the Magneto-optical Response of Magnetoplasmonic Dimers

The effect that dipole-dipole interactions have on the magneto-optical (MO) properties of magnetoplasmonic dimers is theoretically studied. The specific plasmonic versus magnetoplasmonic nature of the dimer's metallic components and their specific location within the dimer plays a crucial role on the determination of these properties. We find that it is possible to generate an induced MO activity in a purely plasmonic component, even larger than that of the MO one, therefore dominating the overall MO spectral dependence of the system. Adequate stacking of these components may allow obtaining, for specific spectral regions, larger MO activities in systems with reduced amount of MO metal and therefore with lower optical losses. Theoretical results are contrasted and confirmed with experiments for selected structures

Life-cycle assessment of the thermal and catalytic pyrolysis over sepiolite of face masks

Since the start of the global COVID-19 pandemic, extensive quantities of face masks have been used and discarded. Most of these masks end up in landfills, causing a high environmental impact and no benefits. However, there are alternative ways to deal with this waste in a more sustainable way. For example, valorisation of face masks through pyrolysis has received special attention because it offers efficient application to produce a liquid oil that can be used as a diesel substitute and a solid char that can be used as an activated carbon substitute after activation. In this context, this study applies the Life-Cycle Assessment methodology to quantify and analyse the environmental impacts of different treatment scenarios based on the pyrolysis of surgical masks and FFP2 masks. It also compares their environmental performance with the conventional practice of landfilling. The scenarios studied include both thermal and catalytic pyrolysis by using sepiolite, a low-cost material abundant in Spain. Data on the pyrolysis process were obtained from laboratory experiments. It was found that the use of the produced oil as a diesel substitute very significantly reduces the environmental impact in all pyrolysis scenarios. Consequently, the pyrolysis of face masks can reduce the environmental impact caused by the treatment of this waste material. Furthermore, the thermal pyrolysis performs environmentally better than the catalytic pyrolysis. In all scenarios, freshwater ecotoxicity and marine ecotoxicity are the environmental impact categories that cause the highest environmental impact overall

Mitochondria and chromaffin cell function

Producción CientíficaChromaffin cells are an excellent model for stimulus– secretion coupling. Ca2+ entry through plasma membrane voltage-operated Ca2+ channels (VOCC) is the trigger for secretion, but the intracellular organelles contribute subtle nuances to the Ca2+ signal. The endoplasmic reticulum amplifies the cytosolic Ca2+ ([Ca2+]C) signal by Ca2+- induced Ca2+ release (CICR) and helps generation of microdomains with high [Ca2+]C (HCMD) at the subplasmalemmal region. These HCMD induce exocytosis of the docked secretory vesicles. Mitochondria close to VOCC take up large amounts of Ca2+ from HCMD and stop progression of the Ca2+ wave towards the cell core. On the other hand, the increase of [Ca2+] at the mitochondrial matrix stimulates respiration and tunes energy production to the increased needs of the exocytic activity. At the end of stimulation, [Ca2+]C decreases rapidly and mitochondria release the Ca2+ accumulated in the matrix through the Na+/Ca2+ exchanger. VOCC, CICR sites and nearby mitochondria form functional triads that co-localize at the subplasmalemmal area, where secretory vesicles wait ready for exocytosis. These triads optimize stimulus–secretion coupling while avoiding propagation of the Ca2+ signal to the cell core. Perturbation of their functioning in neurons may contribute to the genesis of excitotoxicity, ageing mental retardation and/or neurodegenerative disorders

Relationship between sport level competition and serving skill in female beach volleyball

El objetivo principal de este estudio fue analizar el saque empleado por las jugadoras de vóley playa femenino, para determinar si existen diferencias en función del nivel de juego. Se analizaron 1.100 acciones de saque. Las variables del saque estudiadas fueron: tipo, profundidad de golpeo, lateralidad, trayectoria, destino, y técnica de golpeo. Se realizó un estudio de confiabilidad, para determinar el grado de concordancia inter e intraobservadores, llegando a alcanzar una concordancia entre los observadores >0,80. Los resultados del análisis correlacional mostraron una diferencia en el patrón de saque utilizado tras el cruce de variables criterio estudiadas, mostrando el test de Chi-cuadrado de Pearson significación en el cruce (p .80. The results obtained by the correlation analysis showed a difference in the pattern of the service employed after crossing the studied criterion variables. Pearson’s Chi-square test showed a significance (p <.05). The serve pattern identified for international competitive level couples showed a greater difficulty on the execution and precision of the service, becoming the first element of attack; while for the national competitive level ones, the technical difficulty in execution and precision was lowe

Automatic vacant parking places management system using multicamera vehicle detection

This paper presents a multicamera system for vehicles detection and their corresponding mapping into the parking spots of a parking lot. Approaches from the state-of-the-art, which work properly in controlled scenarios, have been validated using small amount of sequences and without more challenging realistic conditions (illumniation changes, different weather). On the other hand, most of them are not complete systems, but provide only parts of them, usually detectors. The proposed system has been designed for realistic scenarios considering different cases of occlussion, ilumination changes and different climatic conditions; a real scenario (the International Pittsburgh Airport parking lot) has been targeted with the condition that existing parking security cameras can be used, avoiding the deployment of new cameras or other sensors infrastructures. For design and validation, a new multicamera dataset has been recorded. The system is based on existing object detectors (the results of two of them are shown) and different proposed postprocessing stages. The results clearly show that the proposed system works correctly in challenging scenarios including almost total occlusions, illumination changes and different weather conditionsThis work has been partially supported by the Spanish Government FPU grant programme (Ministerio de Educación, Cultura y Deporte) and by the Spanish government under the project TEC2014-53176-R (HAVideo

Reversible Graphene decoupling by NaCl photo-dissociation

We describe the reversible intercalation of Na under graphene on Ir(111) by photo-dissociation of a previously adsorbed NaCl overlayer. After room temperature evaporation, NaCl adsorbs on top of graphene forming a bilayer. With a combination of electron diffraction and photoemission techniques we demonstrate that the NaCl overlayer dissociates upon a short exposure to an X-ray beam. As a result, chlorine desorbs while sodium intercalates under the graphene, inducing an electronic decoupling from the underlying metal. Low energy electron diffraction shows the disappearance of the moir\'e pattern when Na intercalates between graphene and iridium. Analysis of the Na 2p core-level by X-ray photoelectron spectroscopy shows a chemical change from NaCl to metallic buried Na at the graphene/Ir interface. The intercalation-decoupling process leads to a n-doped graphene due to the charge transfer from the Na, as revealed by constant energy angle resolved X-ray photoemission maps. Moreover, the process is reversible by a mild annealing of the samples without damaging the graphene

Potential of (2E,7E)-Nonadienedioates in Asymmetric Synthesis: Construction of Homopipecolic Acid and an Aminoester Building Block for Peptide Nucleic Acids

[ES]Se describe la adición asimétrica de Michael de (R)-N-bencil-N-alfa- metilbencilamiduro de litio al diester ortogonalmente sustituido (2E,7E)-nonadienedioato de hidrogeno y metilo para obtener un aducto de monoadición que por posterior manipulación del doble enlace remanente conduce a una síntesis eficaz de ácido (R)-homopipecolico y monomeros utiles en la sintesis de ácidos péptido nucleicos.MICINN (EUI2008-00173), MEC (CTQ2009-11172/BQU), FSE and Junta de Castilla y León (Spain): (SA001A09) y Grupo de Excelencia GR-17

On the correlation between the X-ray absorption chemical shift and the formal valence state in mixed-valence manganites

7 páginas, 7 figuras.Here the correlation between the chemical shift in X-ray absorption spectroscopy, the geometrical structure and the formal valence state of the Mn atom in mixed-valence manganites are discussed. It is shown that this empirical correlation can be reliably used to determine the formal valence of Mn, using either X-ray absorption spectroscopy or resonant X-ray scattering techniques. The difficulties in obtaining a reliable comparison between experimental XANES spectra and theoretical simulations on an absolute energy scale are revealed. It is concluded that the contributions from the electronic occupation and the local structure to the XANES spectra cannot be separated either experimentally or theoretically. In this way the geometrical and electronic structure of the Mn atom in mixed-valence manganites cannot be described as a bimodal distribution of the formal integer Mn3+ and Mn4+ valence states corresponding to the undoped references.This work was supported by the Spanish MICINN FIS2008- 03951 project and Diputación General de Aragón (DGACAMRADS). VC thanks the FPU research grant from MICINN.Peer reviewe