12,390 research outputs found
Wetland restoration and nitrate reduction: the example of the periurban wetland of Vitoria-Gasteiz (Basque Country, North Spain)
Changes in land use and agricultural intensification caused wetlands on the quaternary aquifer of Vitoria-Gasteiz (Basque Country) to disappear some years ago and nitrate concentration in groundwaters increased very quickly. The Basque Government recently declared the East Sector of this aquifer a Vulnerable Zone according to the 91/676/CEE European Directive. Recently, the wetlands have been restored through the closure of the main drainage ditches, the consequent elevation of the water table and the abondonment of agricultural practices near the wetlands. This is the case of the Zurbano wetland. Restoration has allowed the recovery of its biogeochemical function, which has reduced nitrate concentrations in waters. Nitrate concentrations which exceed 50 mg l–1 in groundwaters entering into the wetland are less than 10 mg l–1 at the outlet. Conditions in the wetland are conducive to the loss of nitrates: organic matter rich wetted soils, clay presence allowing a local semiconfined flow and very low hydraulic gradient. Water quality monitoring at several points around the wetland showed the processes involved in nitrate loss, although some aspects still remain unresolved. However, during storm events, the wetland effectively reduces the nitrate concentration entering the Alegria River, the most important river on the quaternary aquifer
Affine semigroups having a unique Betti element
We characterize affine semigroups having one Betti element and we compute
some relevant non-unique factorization invariants for these semigroups. As an
example, we particularize our description to numerical semigroups.Comment: 8 pages, 1 figure. To appear in Journal of Algebra and its
Application
Efecto de la impregnación al vacío sobre los cambios físicos durante la elaboración de aceitunas de mesa
Among the benefits which vacuum impregnation (VI) may provide to fruits and vegetables, this study focused on weight and texture changes during the processing of table olives. VI applied to Manzanilla olives led to around 10% weight gain, which was maintained after their packing as black olives. However, this weight gain was only around 4 % for Hojiblanca olives. Likewise, the use of calcium chloride was recommended to maintain the firmness of the olives, in particular those of the softer Manzanilla cultivar. With regard to the Spanish-style, the Hojiblanca cultivar achieved around 4% weight gain during processing but the use of VI for Manzanilla olives was ruled out due to softening of the fruit. In addition. the black and green color of olives and their flavor were not modified by the application of VI. This technology could be very useful to reduce weight loss during table olive processing.Entre los beneficios que la aplicación de la impregnación al vacío puede originar en frutas y verduras, este estudio se ha centrado sobre los cambios en la textura y el peso de las aceitunas de mesa durante su procesamiento. La impregnación al vacío de aceitunas Manzanilla dio lugar a un aumento cercano al 10 % de peso y ello se mantuvo después de su envasado como aceitunas negras, mientras que esta ganancia fue de sólo el 4& para aceitunas Hojiblanca. Asimismo, se vio necesario el empleo de cloruro cálcico para el mantenimiento de la textura de los frutos, en particular para aquellos de la variedad Manzanilla. Con respecto al procesamiento como verdes estilo español, la variedad Hojiblanca consiguió un aumento del 4% en peso debido al empleo de impregnación al vacío y este tratamiento se descartó para la Manzanilla debido al ablandamiento de la aceituna. Además, se debe indicar que el color verde y negro de las aceitunas no se vio afectado por el hecho de emplear impregnación al vacío. Esta tecnología podría ser muy útil para reducir las pérdidas de peso que se producen durante la elaboración de aceitunas de mesa
Learning technologies and EFL teamwork
In this article, we discuss how technology-based learning methodologies developed in primary and secondary education can offer useful approaches to higher education instruction. For example, young and adult Spanish speakers are often used to participating in discussions and debates in their English as a Foreign Language (EFL) courses. This paper highlights how this model can help support a wider collaborative, ubiquitous learning environment that supports in-class and out-of-class interactions that allow 21st century second-language learners to work with other peers in building (digital) knowledge and forming stronger arguments in English. This article emphasizes that mastering communication skills, cooperation, and collaboration through a combination of learning technologies are themselves necessary 21st century skills in today’s citizens. These capabilities can help to establish a continuous lifelong learning orientation when dealing with education at different stages of life. We will conclude that higher education assessment strategies need to be transformed in order to appreciate these collaborative, digital and EFL students’ outcomes
THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy
This is the first of a series of papers presenting the THROES (A caTalogue of
HeRschel Observations of Evolved Stars) project, intended to provide a
comprehensive overview of the spectroscopic results obtained in the
far-infrared (55-670 microns) with the Her- schel space observatory on
low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the
catalogue of interactively reprocessed PACS (Photoconductor Array Camera and
Spectrometer) spectra covering the 55-200 microns range for 114 stars in this
category for which PACS range spectroscopic data is available in the Herschel
Science Archive (HSA). Our sample includes objects spanning a range of
evolutionary stages, from the asymptotic giant branch to the planetary nebula
phase, displaying a wide variety of chemical and physical properties. The
THROES/PACS catalogue is accessible via a dedicated web-based inter- face
(https://throes.cab.inta-csic.es/) and includes not only the science-ready
Herschel spectroscopic data for each source, but also complementary photometric
and spectroscopic data from other infrared observatories, namely IRAS (Infrared
Astronomical Satellite), ISO (Infrared Space Observatory) or AKARI, at
overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset
that can be used by the scientific community in the future to deepen our
knowledge and understanding of these latest stages of the evolution of
low-to-intermediate mass stars.Comment: 38 page
A priori mixing of mesons and the |Delta I|=1/2 rule in K\to\pi\pi
We consider the hypothesis of a priori mixings in the mass eigenstates of
mesons to obtain the |Delta I|=1/2 rule in K\to\pi\pi. The Hamiltonian
responsible for the transition is the strong interacting one. The experimental
data are described using the isospin symmetry relations between the strong
coupling constants
Diseño y realización de un programa de prácticas sobre comportamiento, adecuado al tema de etología
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