1,131 research outputs found

    Información y monitoreo: base esencial para el manejo integrado de playas en Latinoamérica

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    El artículo demuestra la importancia de información bien organizada como una base esencial para el manejo integrado de playas. En este contexto se trata de información sobre los varios aspectos de la zona litoral, como física, química, biológica, así como social, económica y cultural. Para obtener tal informacion, hoy en día existen diferentes técnicas in situ y por medios remotos. La aplicación de metodologías y herramientas numéricas para el modelado de procesos hidrodinámicos permite conocer, entender y pronosticar el comportamiento de la costa, con el fin de proponer soluciones que ayuden a un desarrollo sostenible, en equilibrio con el entorno social, cultural y medioambiental. Se presentan ejemplos de tecnologías y metodologías para el monitoreo y la modelación de playas, como una base para su adecuado manejo y desarrollo sostenible.The paper demonstrates the importance of well-organised information as an essential basis for integrated management of beaches. This refers to information about various aspects of the coastal zone: physical, chemical, biological as well as social, economical and cultural. Today different techniques are available to obtain such information, in situ as well as remote. The application of methodologies and numeric tools for the modelling of hydrodynamic processes allows knowing, understanding and predicting the behaviour of the coast, with the aim of proposing solutions that will support sustainable development, in balance with the social, cultural and environmental surroundings. Examples of technologies and methodologies will be presented for the monitoring and modelling of beaches, as a basis for their adequate management and sustainable development

    Partículas superparamagnéticas ultrapequeñas de óxido de hierro para aplicaciones biomédicas

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    Las partículas superparamagnéticas ultrapequeñas de óxido de hierro (USPIO) tienen una enorme utilidad enBiomedicina como agentes de contraste en resonancia magnética de imagen o como sistemas transportadores defármacos, entre otras aplicaciones. La naturaleza del recubrimiento de los núcleos inorgánicos de las partículasUSPIO determina su estabilidad in vitro y su comportamiento in vivo, siendo especialmente importantes sus propiedadesfi sicoquímicas, en concreto el tamaño, la carga superfi cial y la densidad del recubrimiento. Las pequeñasdimensiones de las partículas USPIO hace difícil una caracterización fi sicoquímica completa, la cuál es de sumaimportancia para poder mejorar su estabilidad y comportamiento in vivo. Esta revisión se centra en las técnicasinstrumentales utilizadas en el análisis de los núcleos magnéticos y de sus recubrimientos orgánicos

    Adult social isolation leads to anxiety and spatial memory impairment: Brain activity pattern of COx and c-Fos

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    Social isolation during adulthood is a frequent problem that leads to a large variety of adverse emotional and cognitive effects. However, most of the social isolation rodent procedures begin the separation early post-weaning. This work explores locomotor activity, anxiety-like behaviour, and spatial working memory after twelve weeks of adult social isolation. In order to study the functional contribution of selected brain areas following a working memory task, we assessed neuronal metabolic activity through quantitative cytochrome oxidase histochemistry and c-Fos immunohistochemistry. Behaviourally, we found that isolated animals (IS) showed anxiety-like behaviour and worse working memory than controls, whereas motor functions were preserved. Moreover, IS rats showed lower levels of learning-related c-Fos immunoreactivity, compared to controls, in the medial prefrontal cortex (mPFC), ventral tegmental area (VTA), and nucleus accumbens shell. In addition, the IS group showed lower neuronal metabolic activity in the mPFC, VTA, and CA1 subfield of the hippocampus. These results indicate that twelve weeks of social isolation in adult rats leads to different behavioural and brain alterations, and they highlight the importance of social support, not only in development, but also in adulthood

    Influence of Ceramic Recycled Aggregates on the Properties of Prestressed Precast Concrete Elements

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    This work presents the results of an experimental study performed on the mechanical behavior of concrete manufactured with ceramic recycled aggregates (CRA), from precast ventilation ducts, that once made have been rejected by defective. The ultimate objective is to use these wastes to manufacture prestressed concrete joists used in building floors. The coarse fraction and the fine fraction have been considered. The work has been carried out in three phases: characterization of the material, characterization of concrete with CRA and manufacturing and testing of prestressed joists. With the results obtained it is determined the influence of the ceramic recycled aggregate on the properties analyzed. There are not enough studies about prestressed elements that include the replacement of the aggregate in the fine fraction. In view of the results obtained could both of fine and coarse fraction can be used in these applications

    Determination of the stability of Kollicoat MAE 30D by means of differential scanning calorimetry

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    Se estudia la estabilidad de Kollicoat MAE 30D mediante determinaciones calorimétricas y microscópicas. Se estudianlos efectos que producen pH, temperatura y agitación sobre las propiedades fi sicoquímicas de las partículas deeste latex comercial. Se comprueba que el factor que mas infl uencia ejerce es el pH, siendo máxima la estabilidad apH ácidos, y modifi cándose con un decrecimiento de la misma, a partir de pH 6. Se determina la forma y tamañode partícula mediante medidas microfotográfi cas de SEM, realizando el recuento de 200 partículas de una muestradel latex previamente desecado. Se comprueba que la dispersión acuosa de Kollicoat MAE 30 D a su pH natural(2.5), da lugar a una población de partículas con un diámetro medio de 1.56 nm.The stability of Kollicoat MAE 30 D was studied with differential scanning calorimetric, and scanning electronmicroscopy. We investigated the effects of pH, temperature and shaking on physicochemical properties of the latexparticles. Stability of the polymer as most strongly affected by pH; hence, we conclude that the stability of this latexreaches a maximum at acid pH values, where as stability is lost to pH 6.The particle shape and the mean diameter were determined by means of SEM microphotographs on 200 particles in asample of dry latex. The aqueous Kollicoat MAE 30 D dispersion, at its natural pH (2.5), presented one population ofparticles with a mean diameter of 1.56 nm

    Biogeographical characterization of Trichodoridae in the Iberian Peninsula

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    The existence of two faunistic groups has been found on analysis of the distribution patterns of the 18 species from the family Trichodoridae that have been found in representative crops and environments of the Iberian Peninsula. The first one represented by the autochthonous species, Paratrichodorus hispanus, Trichodorus azorensis, T. beirensis, T. giennensis and T. lusitanicus, is present in uncultivated and cultivated areas; T. azorensis, T. beirensis and T. giennensis have been found very localised, while P. hispanus is widespread in Spain and Northern Portugal and T. lusitanicus is common mainly in southern but also found in central Portugal. The second one is defined by the plant parasitic and virus vector species, P. minor, P. pachydermus, P. teres, T. primitivus, T. sparsus and T. viruliferus, in which P. anemones and T. similis could also be included, in spite of their very localised presence. Paratrichodorus anemones, P. pachydermus, T. similis and T. viruliferus could be regarded as characteristic species from temperate environments, while P. minor, the most widespread species in subtropical crops, has also been found in the Canary and Madeira Islands. On the other hand, P. teres, T. giennensis, T. similis, T. sparsus and T. viruliferus have only been found in Spain, while P. acutus, P. allius, P. nanus, P. porosus, T. azorensis and T. orientalis appeared very localised only in Portugal, P. acutus, P. porosus and T. azorensis appearing only in the Azores and Madeira Archipelagos. Climatic, vegetation and soil type influence are discussed.Fundação para a Ciência e a Tecnologia (FCT)CBMA, U

    Teaching innovation project: Formative and shared assessment in education. Results of knowledge transfer between university and school

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    En este trabajo presentamos el desarrollo del Proyecto de Innovación Docente (PID) “La evaluación Formativa y compartida en educación. Transferencia de conocimiento entre Universidad y Escuela”, desarrollado en la Universidad de Valladolid. Hemos desarrollado un estudio de caso analizando la doble vía de transferencia de conocimiento: de la universidad a la escuela y de la escuela a la universidad. Para ello se han organizado dos líneas de intervención: (a) desarrollo de Proyectos de Aprendizaje Tutorados, periodos de Prácticum, Trabajos Fin de Grado, Trabajos Fin de Máster y Tesis Doctorales; (b) desarrollo un seminario internivelar sobre Evaluación Formativa y Compartida, como actividad de formación permanente para el profesorado de todas las etapas educativas, desde educación infantil hasta la universidad. Hemos obtenido como resultados ventajas, inconvenientes y propuestas de mejora para cursos posteriores desde el punto de vista del aprendizaje del alumno, la docencia del maestro y el propio proceso de enseñanza y aprendizajeIn this work we present the development of the Teaching Innovation Project (TIP) "The Formative and shared assessment in education. Transfer of knowledge between University and School ", developed at the University of Valladolid, specifically in the Faculty of Education of Segovia. We have developed a case study analyzing the double way of knowledge transfer: from the university to the school and from the school to the university. To this end, two lines of intervention have been organized: (a) the development of Tutored Learning Projects, internship periods, Final Degree Projects, Master's Thesis and Doctoral Theses; (b) the development of an inter-classroom seminar on Formative and Shared Evaluation, as a permanent training activity for teachers in all stages of education, from early childhood education to university. We have obtained as a result advantages, disadvantages and proposals for improvement for later courses from the point of view of student learning, teacher teaching and the teaching and learning process itsel

    Generation of H₂ on Board Lng Vessels for Consumption in the Propulsion System

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    [Abstract] At present, LNG vessels without reliquefaction plants consume the BOG (boil-off gas) in their engines and the excess is burned in the gas combustion unit without recovering any of its energy content. Excess BOG energy could be captured to produce H₂, a fuel with high energy density and zero emissions, through the installation of a reforming plant. Such H₂ production would, in turn, require on-board storage for its subsequent consumption in the propulsion plant when navigating in areas with stringent anti-pollution regulations, thus reducing CO₂ and SOₓ emissions. This paper presents a review of the different H₂ storage systems and the methods of burning it in propulsion engines, to demonstrate the energetic viability thereof on board LNG vessels. Following the analysis, it is identified that a pressurised and cooled H₂ storage system is the best suited to an LNG vessel due to its simplicity and the fact that it does not pose a safety hazard. There are a number of methods for consuming the H₂ generated in the DF engines that comprise the propulsión plant, but the use of a mixture of 70% CH₄-30% H₂ is the most suitable as it does not require any modifications to the injection system. Installation of an on-board reforming plant and H₂ storage system generates sufficient H₂ to allow for almost 3 days’ autonomy with a mixture of 70%CH₄-30%H₂. This reduces the engine consumption of CH₄ by 11.38%,thus demonstrating that the system is not only energy-efficient, but lends greater versatility to the vessel

    Summer diet of cattle grazing in lenga forests (Nothofagus pumilio) and flood meadows of Chubut, Argentina

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    Se determinó la composición de la dieta de verano de bovinos pastoreando en sistemas formados por bosques de Nothofagus pumilio (lenga) y mallines, del noroeste del Chubut. Se estimó la disponibilidad forrajera de los mallines y del sotobosque mediante cortes de biomasa aérea, y se determinó la composición dietaria mediante análisis microhistológico de heces. La dieta está integrada principalmente por especies de gramíneas y graminoides, que disminuyeron su frecuencia al final del verano, mientras que los renovales de lenga y otras especies leñosas la aumentaron. El ganado selecciona gramíneas en ambos períodos, y al final del verano también los renovales de lenga. La ganadería constituye una importante y creciente forma de subsistencia para los pobladores rurales del noroeste del Chubut. Este trabajo aporta elementos para avanzar en la búsqueda de herramientas que permitan la sustentabilidad de los bosques de lenga.Summer diet composition of cattle grazing in systems formed by Nothofagus pumilio forests (lenga) and flood meadows, in Northwest of Chubut, was determined. Forage availability in flood meadows and understory were estimated by cutting aboveground biomass. Cattle diet composition was assessed using faeces microhistological analysis. Diet consisted mainly of Poaceae and Cyperaceae species, which decreased in frequency at the end of summer grazing, on the other hand, frequency of woody species including lenga saplings, increased at the same period. Cattle selected grass species in both periods, and also lenga saplings in the end of summer. Livestock is an important economic activity for the inhabitants of the region. This paper provides information that can be for the elaboration of guideline for sustainable coexistence of forest and cattle.Fil: Quinteros, Claudia P.. Centro de Investigación y Extensión Forestal Andino Patagónico (Chubut, Argentina)Fil: Feijóo, Sandra M.. Universidad Nacional de la Patagonia San Juan Bosco. Facultad de Ciencias Naturales. Departamento de BiologíaFil: Arias, Nadia S.. Universidad Nacional de la Patagonia San Juan Bosco. Facultad de Ciencias Naturales. Departamento de BiologíaFil: López Bernal, Pablo M.. Centro de Investigación y Extensión Forestal Andino Patagónico (Chubut, Argentina)Fil: Bava, José O.. Centro de Investigación y Extensión Forestal Andino Patagónico (Chubut, Argentina
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