La contaminación por metales pesados en las Rías Baixas gallegas: nuevos valores de fondo para la Ría de Vigo (NO de España).

La valoración de la contaminación de un área dada depende en gran medida de la determinación precisa de los denominados valores de fondo o naturales. Numerosos autores han aportado valores de fondo para las Rías basándose en distintos análisis estadísticos y de muestras superficiales. En este trabajo se revisan y proponen nuevos valores de fondo basándose en los valores de concentración de metales pesados determinados mediante espectrometría de absorción atómica y fluorescencia de rayos X de un testigo profundo recogido en una zona muy contaminada de la Ría de Vigo. Se confirman los valores de fondo previos para Fe, Al, Mn, Ti, Ni, Co y Zn. Se proponen unos valores nuevos para Cu, Cr y Pb de 20, 55 y 25 µg g­1, respectivamente. Se revisan y discuten los métodos para minimizar el efecto tamaño de grano, comparando la normalización por Al y por Rb. En este sentido, se enfatiza la acción diluyente de los carbonatos en los sedimentos que puede llegar a enmascarar dicho efecto. Con los nuevos valores de fondo aportados se reinterpreta el estado de contaminación de la Ría de Vigo, que muestra valores moderados para Cu, Zn y Cr, pero considerables para Pb, especialmente en la ensenada de San Simón. El 121 B. Rubio et al. La contaminación por metales pesados en las Rías Baixas gallegas... cálculo de un índice de contaminación metálica (ICM) permite delimitar las áreas contaminadas y grado de afectación por estos metales. La ensenada de San Simón y las proximidades a la zona portuaria de Vigo son las partes más afectadas, en respuesta a la influencia industrial.Pollution assessment in a given area depends mostly on the accurate determination of the so-called background values. Several authors have reported different background values for the Rías based on different statististical analyses but using only surface samples. New background values are proposed based on the metal concentrations determined by different techniques (atomic absorption spectrometry ­AAS- and X-ray fluorescence ­XRF-) for a long gravity core collected in a very highly polluted area in the Ría de Vigo. The validity of some previous background values is confirmed for Fe, Al, Mn, Ti, Ni, Co and Zn. New background values are proposed for Cu, Cr and Pb, 20, 55 and 25 µg g­1, respectively. We revise the methods to minimize grain size effect, comparing the normalization with Al and Rb. In this sense, the diluting effect of the carbonates, masking the grain size effect, is emphasized. The contamination status for the Ría de Vigo is reinterpreted with the new background values. Moderate pollution for Cu, Zn and Cr was found. For Pb pollution was substantial in general terms, being very high in the bay of San Simón. The calculation of a metal pollution index allowed us to delimite the areas and pollution grades caused by these metals. The bay of San Simón and the surroundings of Vigo harbour were the most affected areas, showing the industrial influence

The Effect of Proton Radiation Damage to the RNA Enzyme RNASE-P

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

A taxonomy for key performance indicators management

In recent years, research on Key Performance Indicators (KPIs) management has grown exponentially, giving rise to a multitude of heterogeneous approaches addressing any aspect concerning it. In this paper, we plot the landscape of published works related with KPIs management, organizing and synthesizing them by means of a unified taxonomy that encompasses the aspects considered by other proposals, and it captures the overall characteristics of KPIs. Since most of the literature centers on the definition of KPIs, we mainly focus on such an aspect of KPIs management. Our work is intended to provide remarkable benefits such as enhancing the understanding of KPIs management, or helping users decide about the most suitable solution for their requirements

Synthesis of layered titanosilicate JDF-L1 for fabrication of composite polyamide 6 film

In clay polymer nanocomposite technology, nowadays there is concern about the safety and environmental effects of the nanometric materials. In this work, sheets of layered titanosilicate JDF-L1 were synthesized with a size of 5.3 µmand thickness of 115 nm and used to fabricate composite polyamide 6 (PA6) films. The JDF-L1 synthesis was scaled in one pot and the rosette-like particles obtained were disaggregated using a simple process with NaOH solution. The composite with 2 wt.% of disaggregated JDF-L1, characterized by X-ray diffraction and electron microscopy, showed parallel orientation (with respect to the film itself) and good dispersion of the sheets. The composite had a similar barrier effect as the PA6 and its mechanical properties did not deteriorate. This opens up the use of this composite as a packing material providing other properties, such as a biocidal effect and synergy effect in combination with other additives

Influence of the surface viscous stress on the pinch-off of free surfaces loaded with nearly-inviscid surfactants

We analyze the breakup of a pendant water droplet loaded with SDS. The free surface minimum radius measured in the experiments is compared with that obtained from a numerical solution of the Navier–Stokes equations for diferent values of the shear and dilatational surface viscosities. This comparison shows the small but measurable efect of the surface viscous stresses for sufciently small spatiotemporal distances from the breakup point, and allows to establish upper bounds for the values of the shear and dilatational viscosities. We study numerically the distribution of Marangoni and viscous stresses over the free surface as a function of the time to the pinching, and describe how surface viscous stresses grow in the pinching region as the free surface approaches its breakup. When Marangoni and surface viscous stresses are taken into account, the surfactant is not swept away from the thread neck in the time interval analyzed. Surface viscous stresses eventually balance the driving capillary pressure in in the pinching region for small enough values of the time to pinching. Based on this result, we propose a scaling law to account for the efect of the surface viscosities on the last stage of temporal evolution of the neck radius.Ministerio de Economía y Competitividad DPI2016-78887Junta de Extremadura GR1817

A Postprocessing methodology for direct normal irradiance forecasting using cloud information and aerosol load forecasts

A method for direct normal irradiance (DNI) forecasting for specific sites is proposed. It is based on the combination of a numerical weather prediction (NWP) model, which provides cloud information, with radiative transfer simulations fed with external aerosol forecasts. The NWP model used is the ECMWF Integrated Forecast System, and the radiative transfer information has been obtained from the Library of Radiative Transfer (libRadtran). Two types of aerosol forecasts have been tested: the global Monitoring Atmospheric Composition and Climate (MACC) model, which predicts five major components of aerosols, and the Dust Regional Atmospheric Model (BSC-DREAM8b) added to a fixed background calculated as the 20th percentile of the monthly mean of AERONET 2.0 observations from a different year. The methodology employed is valid for all meteorological situations, providing a stable and continuous DNI curve. The performance of the combined method has been evaluated against DNI observations and compared with the pure ECMWF forecasts at eight locations in the southern half of mainland Spain and the Canary Islands, which received high loadings of African dust for 2013 and 2014. Results for 1-day forecasts are presented. Although clouds play a major role, aerosols have a significant effect, but at shorter time scales. The combination of ECMWF and MACC forecasts gives the best global results, improving the DNI forecasts in events with high aerosol content. The regional BSC-DREAM8b yields good results for some extremely high dust conditions, although more reliable predictions, valid for any aerosol conditions, are provided by the MACC model

High-trhoughput screening of cytochrome C novel partners chlamydomonas ReindhartII

Comunicaciones a congreso

Produzione, mercato e consumi della cerasicoltura spagnola

La crisi di sovrapproduzione di alcune specie tradizionali sta favorendo la crescita del ciliegio, che mostra un costante incremento delle superfici, favorito dal rinnovamento varietale, dall’aumento dei consumi, dal miglioramento delle tecnologie di produzione e dalla precocità di maturazione. Tutti fattori che garantiscono alla Spagna elevata competitività nelle esportazioni verso i Paesi dell’Ue.Colaboración en el blog: Rivista di frutticoltura e di ortofloricoltura. Disponible: http://www.rivistafrutticoltura.it