112 research outputs found
Community Structure Characterization
This entry discusses the problem of describing some communities identified in
a complex network of interest, in a way allowing to interpret them. We suppose
the community structure has already been detected through one of the many
methods proposed in the literature. The question is then to know how to extract
valuable information from this first result, in order to allow human
interpretation. This requires subsequent processing, which we describe in the
rest of this entry
Análisis de las diferencias entre el resultado contable y la base imponible del Impuesto sobre Sociedades en las Entidades sin Finalidad Lucrativa
La publicación de la Ley 30/1994, de 24 de noviembre, de fundaciones y de incentivos fiscales a la participación privada en actividades de interés general, supuso una actualización de la legislación sobre fundaciones al mismo tiempo que ofrecÃa una regulación sistemática, ordenada y precisa en contraposición a la dispersión de normas que existÃa hasta la fecha. Dentro del TÃtulo II de la Ley, el CapÃtulo I «Régimen tributario de las entidades sin fines lucrativos» regula el régimen fiscal de las entidades sin finalidad lucrativa que cumplan con los requisitos exigidos en dicho CapÃtulo. Sin embargo, las entidades que no cumplan con estos requisitos no se pueden acoger a este régimen tributario más favorable, y les es aplicable la Ley 43/1995 en sus artÃculos 133-135.
El objetivo principal de este trabajo es analizar las diferencias de carácter permanente que existen entre el resultado contable y la base imponible del Impuesto sobre Sociedades en las entidades sin finalidad lucrativa. Las diferencias de carácter temporal que puedan surgir quedan fuera del alcance de este estudio, si bien hay que indicar que son las mismas que para el resto de entidades y su tratamiento contable es similar.
Para ello, en primer lugar, partiremos de la definición de la base imponible del Impuesto sobre Sociedades que establece la Ley 30/1994 para analizar sus componentes y sus diferencias con la que se establece en los artÃculos 133-135 de la Ley 43/1995, asà como el tratamiento contable de estas magnitudes contenido en el Real Decreto 776/1998, de 30 de abril, por el que se aprueban las normas de adaptación del Plan General de Contabilidad a las entidades sin fines lucrativos y las normas de información presupuestaria de estas entidades. En la última parte se analizan las particularidades sobre la cuota lÃquida, la cuota reducida y la cuota diferencial
Robust Poisson Surface Reconstruction
Abstract. We propose a method to reconstruct surfaces from oriented point clouds with non-uniform sampling and noise by formulating the problem as a convex minimization that reconstructs the indicator func-tion of the surface’s interior. Compared to previous models, our recon-struction is robust to noise and outliers because it substitutes the least-squares fidelity term by a robust Huber penalty; this allows to recover sharp corners and avoids the shrinking bias of least squares. We choose an implicit parametrization to reconstruct surfaces of unknown topology and close large gaps in the point cloud. For an efficient representation, we approximate the implicit function by a hierarchy of locally supported basis elements adapted to the geometry of the surface. Unlike ad-hoc bases over an octree, our hierarchical B-splines from isogeometric analysis locally adapt the mesh and degree of the splines during reconstruction. The hi-erarchical structure of the basis speeds-up the minimization and efficiently represents clustered data. We also advocate for convex optimization, in-stead isogeometric finite-element techniques, to efficiently solve the min-imization and allow for non-differentiable functionals. Experiments show state-of-the-art performance within a more flexible framework.
Anaerobic digestion of screenings for biogas recovery
Screenings comprise untreatable solid materials that have found their way into the sewer. They are removed during preliminary treatment at the inlet work of any wastewater treatment process using a unit operation termed as a screen and at present are disposed of to landfill. These materials, if not removed, will damage mechanical equipment due to its heterogeneity and reduce overall treatment process, reliability and effectiveness. That is why this material is retained and prevented from entering the treatment system before finally being disposed of. The amount of biodegradable organic matter in screenings often exceeds the upper limit and emits a significant amount of greenhouse gases during biodegradation on landfill. Nutrient release can cause a serious problem of eutrophication phenomena in receiving waters and a deterioration of water quality. Disposal of screenings on landfill also can cause odour problem due to putrescible nature of some of the solid material. In view of the high organic content of screenings, anaerobic digestion method may not only offer the potential for energy recovery but also nutrient. In this study, the anaerobic digestion was performed for 30,days, at controlled pH and temperature, using different dry solids concentrations of screenings to study the potential of biogas recovery in the form of methane. It was found screenings have physical characteristics of 30% total solids and 93% volatile solids, suggesting screenings are a type of waste with high dry solids and organic contents. Consistent pH around pH 6.22 indicates anaerobic digestion of screenings needs minimum pH correction. The biomethane potential tests demonstrated screenings were amenable to anaerobic digestion with methane yield of 355,m3/kg VS, which is comparable to the previous results. This study shows that anaerobic digestion is not only beneficial for waste treatment but also to turn waste into useful resources
No iron fertilization in the equatorial Pacific Ocean during the last ice age
The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron1. Greater atmospheric dust deposition2 could have fertilized the equatorial Pacific with iron during the last ice age—the Last Glacial Period (LGP) but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the 232Th proxy), phytoplankton productivity (using opal, 231Pa/230Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ15N) from six cores in the central equatorial Pacific for the Holocene (0–10,000 years ago) and the LGP (17,000–27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region7,8. Thus, ice-age iron fertilization in the Subantarctic Zone would have ultimately worked to lower, not raise, equatorial Pacific productivity
Odor from anaerobic digestion of swine slurry: influence of pH, temperature and organic loading
Biomethane potential of industrial paper wastes and investigation of the methanogenic communities involved
Microorganism-regulated mechanisms of temperature effects on the performance of anaerobic digestion
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