Cellular nanocomposites based on Rigid Polyurethane and Nanoclays: fabrication, characterization and modeling of the mechanical and thermal properties

El presente trabajo explora el efecto de la incorporación de nanoarcillas en la estructura celular, propiedades mecánicas y térmicas de espumas rígidas de poliuretano de una manera distinta a la que se ha venido haciendo en la literatura previa, donde se echaba en falta un mayor detalle en el estudio de aspectos tales como la calidad de la dispersión de las arcillas, su grado de la exfoliación, influencia de éstas en la estructura celular y el modelado de las propiedades. En este trabajo hemos seleccionado un número limitado de formulaciones y un tipo de nanoarcillas con el objetivo de realizar un estudio más detallado. Con los datos obtenidos de la caracterización y mediante el empleo de modelos teóricos, se han identificado los orígenes de los cambios en las propiedades finales, permitiendo estos resultados analizar la influencia de los parámetros que han sido modificados por la aditivación de las nanoarcillas.Departamento de Física de la Materia Condensada, Cristalografía y Minerealogí

Measuring Spatial Dynamics in Metropolitan Areas

This paper introduces a new approach to measuring neighborhood change. Instead of the traditional method of identifying “neighborhoods†a priori and then studying how resident attributes change over time, our approach looks at the neighborhood more intrinsically as a unit that has both a geographic footprint and a socioeconomic composition. Therefore, change is identified when both as- pects of a neighborhood transform from one period to the next. Our approach is based on a spatial clustering algorithm that identifies neighborhoods at two points in time for one city. We also develop indicators of spatial change at both the macro (city) level as well as local (neighborhood) scale. We illustrate these methods in an application to an extensive database of time-consistent census tracts for 359 of the largest metropolitan areas in the US for the period 1990-2000.

La atención centrada en personas mayores en ámbito residencial

El objetivo de este trabajo de fin de grado es describir en profundidad y analizar los beneficios que tiene en los residentes el nuevo modelo de atención centrado en la persona en ámbito residencial a partir de una revisión bibliográfica. En primer lugar se describe al colectivo de personas mayores y la situación demográfica actual de España en relación a ellos. Posteriormente se describe su origen y las experiencias llevadas a cabo en el ámbito internacional y nacional, así como la situación de este nuevo modelo en los servicios gerontológicos de este país. Más adelante se desarrolla exhaustivamente el funcionamiento del modelo con sus características, roles de los/as profesionales e instrumentos para su adecuada aplicación. Y por último se analizan los beneficios, dificultades y riesgos que este nuevo modelo aporta al colectivo, a las familias, y a la organización en su implantación en residencias.Grado en Trabajo Socia

Andalusia in the spanish territorial division of labour. An approach in the light of its socio- economic metabolism

En las páginas que siguen trataremos de aproximarnos al lugar que ocupa Andalucía dentro de la división territorial del trabajo en España utilizando la metodología de la Contabilidad de Flujos Materiales (CFM), con la que se trata de ir más allá de los valores monetarios, haciendo un seguimiento de los flujos físicos involucrados en los procesos económicos en términos de metabolismo social. Para ello utilizamos en la primera parte los datos regionales sobre extracción de materiales y energía, para seguir, en una segunda parte, con la consideración de los flujos físicos comerciales;finalmente, (tercera parte), se atiende a la localización regional de las diferentes ramas de actividad dentro de la economía española para así presentar un dibujo más completo del reparto espacial de funciones y su alcance social y ecológico.Reduced to the isolated universe of monetary value, the conventional economic approach circumscribes the economic dynamics affecting territories, such as the relationships between them, to a set of flows solely expressed in monetary terms. This one-dimensional view disconnects the economic system from the social, physical and territorial world in such a way that the social and economic costs essential for the maintenance and enrichment of life in those territories are ignored. This way of viewing economics generates a conflict between the economy and the territory and this conflict is at the root of ecological degradation which reaches different degrees and has different implications depending on the economic activities occurring in those territories and depending on the role they play within the system and the relationships between them. The territorial division of work, which has been intensified by globalization, has accentuated the polarization between territories devoted to activities located in the later stages of the manufacture and marketing of goods and services, to be found at the apex of the hierarchy of tasks within the division of work (central territories) and territories which supply primary products and which perform the first stages of extraction and processing of natural resources (peripheral territories). Behind the veil of the monetary worldview held by the conventional economy, therefore, lie hidden the relationships of power and the spatial division of work as mechanisms for domination and for the appropriation of the wealth of some territories by others. This paper studies the place occupied by Andalusia in the territorial division of work in Spain using Material Flow Accounting (MFA) methodology. The aim is to look beyond monetary value, monitoring the physical flows involved in the economic processes in terms of social metabolism. To do so, in a step-by-step approach, the first section uses regional data on the extraction of materials and energy, followed in the second section by an examination of physical commercial flows. Finally, in section three, the regional localization of different branches of activity within the Spanish economy is considered. Section 1 compares the capacity for the appropriation of monetary value (GDP) of each Autonomous Community with the endogenous resources generated by each one, represented by the domestic extraction of materials. This reveals a regional grouping in which we can clearly distinguish a set of regions which, with relatively low domestic extraction of resources, appropriate a significant proportion of the monetary value generated by the Spanish economy. Among them, the territories which have traditionally been central to the Spanish economy (Madrid, Catalonia and the Basque Country), (9.3% of the territory), enjoyed 42.6% of the added value in the Spanish economy, which is more than double the figure for their domestic extraction (20.2% of the Spanish total). They are, basically, the regions which use the rest of the territory to supply their production and consumption patterns. On the other hand, there are the majority of the Spanish regions, where 67.9% of the domestic extraction of resources takes place and where 41.3% of added value is enjoyed. In this case, more than half of the extraction (50.2%) is located in five regions: Murcia, Galicia, Castilla La Mancha, Castilla León and Andalusia. The latter is the region with the greatest difference between the GDP obtained and the use of endogenous natural resources. The study of external trade flows offers a clearer profile of Andalusia’s specialization within the Spanish economy as it allows us more clearly to determine what is demanded of the Andalusian economy from outside and, at the same time, makes it possible to incorporate the manufacturing process of products and to calibrate the weighting of different sectors of production within the complex of interregional relationships.With respect to exports, there is considerable concentration in two sectors: Energy products and Food products. These two sectors represented well over half (58.2%) of the products exported from Andalusia to the other Autonomous Communities over the 15 years studied. The first item, Energy products, is related to the relocation to Andalusia in the 1960s of certain industrial activities (oil refining, basic chemical industry, paper mills, initial processing and production of metals) which covers the first stages of production processes whose later, more complex phases, where greater added value is generated, take place outside Andalusia. The ecological degradation associated with this relocation of industrial activities has caused environmental damage in Andalusia which is proportionally much greater than that seen in the industrialized regions. The second item of Andalusian exports, food products, represented 26.0% of total Andalusian exports for the period 1996-2010. Most are agricultural products or the results of the initial processing of foodstuffs, which is simply a prolongation of agricultural activity (fruit, vegetables and oil). In this regard, it is interesting to note that these exports represent a growing proportion of the biomass extracted in Andalusia, and so it can be said that the natural heritage of Andalusia is, increasingly, being used to satisfy the food requirements of other territories which receive primary products from Andalusia with a very low level of processing, and which are distanced from the more dynamic nucleus of the agri-food system. In contrast, it should be noted that the high volume of food products exported to the rest of Spain is accompanied by a similar tonnage of imports from those other regions. These are mainly processed products. Here, a growing gap is to be found between domestic extraction and the internal demand for foodstuffs, which accentuates the food dependency of Andalusia and, at the same time, translates into a sharp disconnection between food production and consumption. The third section looks in greater detail at specialization in the tasks performed in the different territories by looking at the regional localization of economic activities. This gives us a more complete picture of the spatial distribution of those tasks as it uses a more detailed breakdown of the different processing activities and includes services. Here, again, it can be observed that, as it has traditionally been, Andalusia is still an extractive economy, a supplier of primary products. With a system of intensive agriculture on a model in which extraction is forced through the introduction into the system of increasing volumes of materials and energy and the intensity of extraction is increased through the progressive use of intermediate inputs, which are mainly non-renewable, and which, in turn, involve extractive processes in the same and/or other spaces, with the consequent deterioration and progressive degradation of the environment in which this agriculture is practiced, and to which is added to the import of sustainability from other territories. The devotion to extractive industry in the Andalusian economy differentiates and distances it from the “central” economies, as can be seen in a comparison with Catalonia, deepening an unequal exchange between Andalusia and other territories which is masked by the conventional conception of the economy and is related to the fact that, in monetary terms, the contribution of nature has no cost, and to the role of Power relationships within the system. In this paper, Andalusia is seen to be a territory specializing in activities which generate social and ecological damage which remains hidden by the focus of the conventional economy. An area for the appropriation of wealth at low cost by the central territories, from where not only their own spheres of activity are controlled and managed, but also, to a large extent, those of outside and “peripheral” territories such as Andalusia, for which economic growth means the exacerbation of their situation of dependency and marginalization. This domination is not only material. It is also an ideological domination which results in the very situation of domination being interpreted in terms of models and instruments operating in favor of the dominant interests. For Andalusia, this is a path of divergence, not convergence, a path which leads to the loss of control over the management of its resources and the separation of the Andalusian economy from what should be its priority objective: the maintenance and enrichment (sustainability) of social and natural life

Recovery of neodymium (III) from aqueous phase by chitosan-manganese-ferrite magnetic beads

Neodymium is a key rare-earth element applied to modern devices. The purpose of this study is the development of a hybrid biomaterial based on chitosan (CS) and manganese ferrite (MF) for the recovery of Nd(III) ions from the aqueous phase. The preparation of the beads was performed in two stages; first, MF particles were obtained by the assessment of three temperatures during the co-precipitation synthesis, and the best nano-MF crystallites were incorporated into CS to obtain the hybrid composite material (CS-MF). The materials were characterized by FTIR, XRD, magnetization measurements, and SEM-EDX. The adsorption experiments included pH study, equilibrium study, kinetics study, and sorption–desorption reusability tests. The results showed that for MF synthesis, 60 °C is an appropriate temperature to obtain MF crystals of ~30 nm with suitable magnetic properties. The final magnetic CS-MF beads perform maximum adsorption at pH 4 with a maximum adsorption capacity of 44.29 mg/g. Moreover, the material can be used for up to four adsorption–desorption cycles. The incorporation of MF improves the sorption capacity of the neat chitosan. Additionally, the magnetic properties enable its easy separation from aqueous solutions for further use. The material obtained represents an enhanced magnetic hybrid adsorbent that can be applied to recover Nd(III) from aqueous solutionsPeer ReviewedPostprint (published version

Road Sign Analysis Using Multisensory Data

This paper deals with the problem of estimating the following road sign parameters: height, dimensions, visibility distance and partial occlusions. This work belongs to a framework whose main applications involve road sign maintenance, driver assistance, and inventory systems. From this paper we suggest a multisensory system composed from two cameras, a GPS receiver, and a distance measurement device,all of them installed in a car. The process consists of several steps which include road sign detection, recognition and tracking , and road signs parameters estimation. From some trigonometric properties, and a camera model, the information provided by the tracking subsystem and the distance measurement sensors, we estimate the road signs parameters.Results show that the described calculation methodology offers a correct estimation for all types of traffic signs

Road Sign Analysis Using Multisensory Data

This paper deals with the problem of estimating the following road sign parameters: height, dimensions, visibility distance and partial occlusions. This work belongs to a framework whose main applications involve road sign maintenance, driver assistance, and inventory systems. From this paper we suggest a multisensory system composed from two cameras, a GPS receiver, and a distance measurement device,all of them installed in a car. The process consists of several steps which include road sign detection, recognition and tracking , and road signs parameters estimation. From some trigonometric properties, and a camera model, the information provided by the tracking subsystem and the distance measurement sensors, we estimate the road signs parameters.Results show that the described calculation methodology offers a correct estimation for all types of traffic signs

Microburst detection with the WRF model: effective resolution and forecasting indices

Microbursts are meteorological phenomena in the lower troposphere which can produce damaging surface winds and pose a severe risk to aircraft flying close to the ground. As these events usually span less than 4 km and 15 min, the spatiotemporal resolution is a challenge for numerical simulations. Although research of microburst using operative mesoscale models is scarce, the Weather Research and Forecasting (WRF) model has been used in the diagnosis of this phenomenon. In this paper, such model is used to simulate several microburst conducive days using two different boundary conditions. The energy spectra of the simulations are computed to evaluate the effective resolution of the model. The results are in line with previous studies and produce no notable differences among the boundary conditions. Nonetheless, the energy spectra show an overenergetic troposphere at microscale resolutions, rendering the effective resolution inadequate for microburst forecasting using the simulated physics variables. Thus, mesoscale indices are analyzed as a prognostic tool. The wind index, the wet microburst severity index and the microburst windspeed potential index do not show high forecasting performances, even though improving the results of climatology. Also, notable differences among the boundary conditions can be seen. The most consistent results are achieved by the wet microburst severity index

Rigid polyurethane foams with infused nanoclays: Relationship between cellular structure and thermal conductivity

Producción CientíficaA water blown rigid polyurethane (PU) formulation has been used to manufacture cellular nanocomposites containing different concentrations of montmorillonite nanoclays. The PU foams have been produced using a low shear mixing technique for dispersing the nanoclays and by reactive foaming to generate the cellular structure. A detailed characterization of the cellular structure has been performed. The effect of the nanoparticles on the reaction kinetics and the state of intercalation of the nanoparticles in the foams has been analyzed. The thermal conductivity and extinction coefficient of the different materials has been measured and the results obtained have been correlated with the materials structure. A strong reduction of cell size and modifications on cell size distribution, anisotropy ratio and fraction of material in the struts has been detected when the clays are added. In addition, a reduction of the thermal conductivity has been observed. Different theoretical models have been employed to explain thermal conductivity changes in terms of structural features. It has been found that, in addition to the modifications in the cellular structure, changes in the extinction coefficient and thermal conductivity of the matrix polymer play an important role on the final values of the thermal conductivity for these materials.We would like to acknowledge to Mr. Vela and Mr. Ferrer, from BASF Española S.L., for supplying the PU formulation employed in this research. The authors are grateful to the Spanish Ministry of Science and Education which supported this work with a FPU Grant Ref-AP-2008-03602 given to Mr. Estravís. In addition, Financial assistance from the Spanish Ministry of Science and Innovation, FEDER program (MAT 2012 – 34901 and MAT2015-69234-R), the Junta de Castile and Leon (VA035U13) and the EU Commission (FP7 program, EC project NanCore number 214148) is acknowledged

Incertidumbre en la predicción del viento mediante un sistema de predicción por conjuntos: cuantificación y análisis

Ponencia presentada en: XXXV Jornadas Científicas de la AME y el XIX Encuentro Hispano Luso de Meteorología celebrado en León, del 5 al 7 de marzo de 2018.A partir de un sistema de predicción por conjuntos generado con un modelo meteorológico mesoescalar, y mediante un índice basado en la dispersión de los miembros del conjunto, se evalúa la incertidumbre asociada en la predicción de la velocidad del viento a corto plazo en terreno complejo. Se analizan los resultados diferenciando entre distintos casos, según la dirección del viento y si se rebasa un determinado umbral de velocidad del mismo, así como considerando distintas posibilidades de condiciones de estabilidad atmosférica. Así mismo, se separa la contribución a la incertidumbre correspondiente a las parametrizaciones físicas del modelo, por una parte, y a las condiciones iniciales y de contorno por otra. En la mayor parte de los casos la contribución de las condiciones iniciales y de contorno es menor, pero debe ser especialmente tenida en cuenta de determinadas áreas y circunstancias meteorológicas