El 94% dels minerals que s'extrauen a Catalunya es destinen al sector de la construcció

Una tesi doctoral de la UAB ha analitzat, per primera vegada, els impactes mediambientals associats al consum de materials per a la construcció a Catalunya i alerta, entre altres qüestions, que algunes de les principals matèries primeres que s'hi utilitzen, com ara els recursos minerals, podrien arribar aviat al seu límit si continua el ritme de consum actual

Anàlisi dels fluxos de materials de sistemes : avaluació del metabolisme material a diferents escales /

Consultable des del TDXTítol obtingut de la portada digitalitzadaL'anàlisi de les dimensions d'un sistema social o econòmic ja sigui un país, un sector productiu o una empresa, generalment es mesura en unitats monetàries. Com a molt, la sortida dels sistemes productius es quantifica en unitats físiques, ja que aquests són els valors o indicadors que tradicionalment s'han considerat rellevants i útils per a la presa de decisions. La incorporació de criteris ambientals en la presa de decisions és una necessitat marcada pels límits del nostre planeta. Límits condicionats tant per la capacitat finita de subministrament de recursos, com d'assimilació o regeneració dels fluxos emesos com a conseqüència de les activitats antropogèniques. Per poder incorporar aquesta perspectiva ambiental a l'anàlisi dels sistemes, una alternativa és combinar l'anàlisi crematístic tradicional dels sistemes econòmics i productius, amb una anàlisi física. Aquesta anàlisi física ha de permetre quantificar l'entrada de material necessari per generar cada unitat de sortida, tant si tenen valor econòmic com si no, ja que en qualsevol cas, tenen o poden tenir un valor ambiental. En aquest context s'han quantificat les necessitats i el consum de materials de Catalunya entre els anys 1990 i 2004 (capítol 4). Els resultats mostren un clar augment de l'ús de materials en el període analitzat, tant en termes absoluts com per unitat de PIB generat o per capita. Els resultats mostren la forta dependència que Catalunya té de l'exterior per mantenir el ritme de creixement segons el model actual i la gran influència del sector de la construcció en el metabolisme material de tot el país. Per poder determinar, a una escala més reduïda i en més detall, els impactes ambientals associats a les principals fonts de consum de Catalunya, s'ha avaluat el metabolisme del sector de la construcció a Catalunya per l'any 2001 (capítol 5), i s'ha proposat un mètode per a quantificar el metabolisme de les àrees industrials i empreses (capítol 6). Els resultats mostren l'eficiència en l'ús de materials però a aquesta escala es combinen els indicadors de materials amb les necessitats energètiques i el consum d'aigua dels diferents sistemes. Els resultats de l'anàlisi del metabolisme del sector de la construcció (capítol 5) posen en rellevància que el principal problema del sector és l'elevat volum de recursos utilitzats. Aquest gran consum té unes fortes implicacions en l'augment de l'estoc de materials artificialitzats dins del territori català any rere any, però també en unes elevades necessitats energètiques pel transport i processament dels productes utilitzats. Els resultats mostren que la millora en l'eficiència dels processos productius és una mesura insuficient i, que cal combinar-la amb una intervenció que limiti la construcció, si es vol tendir cap a una desmaterialització del país. També mostra la necessitat d'utilitzar l'estoc material present en les construccions existents, com a via per a disminuir la dependència de l'entorn natural propi i extern. Per acabar de completar l'anàlisi del metabolisme del país i les vies de millora en el sector industrial, s'analitza el metabolisme d'una àrea industrial (capítol 6). A través d'un cas d'estudi d'una àrea situada a Santa Perpètua de Mogoda, es proposa una metodologia per quantificar el metabolisme d'àrees industrials. La metodologia és anàloga i comparable a la utilitzada per a tot Catalunya i pel sector de la construcció, i es centra en avaluar els punts dèbils del sistema i quantificar millores a través de la simbiosi industrial entre empreses. De totes les anàlisis realitzades se'n desprenen uns indicadors que, si bé sols no són suficients, combinats amb d'altres eines poden ajudar a quantificar les conseqüències dels nivells d'ús de recursos naturals, posar límits, detectar les oportunitats i els punts dèbils del model econòmic de Catalunya.The Earth' limits require the incorporation of environmental criteria in the decision making. Limits are determined by the restrictions in resources availability and the regenerative capacity of the planet to assimilate the anthropogenic activity. More wide spread analysis to evaluate the dimensions and viability of a socio economic systems, has been done in monetary units, although it is unable to incorporate the limits of the Planet. In order to include the environmental criteria, the monetary analysis should be combined with other tools such as the analysis of the physical dimensions of a socio economic system. This physical quantification allows measuring the material input required per output produced, including its value as a physical resource independently of its monetary value. In this thesis, the material requirement and consumption of Catalunya has been accounted, between 1990 and 2004 (chapter 4). The results show the materialisation of the region in the period analysed, in absolute terms, per GDP and per capita. Catalunya also has a strong dependence on foreign trade to sustain its growth rate and its economic model. The results also confirm the huge influence of the construction sector in the overall metabolism of the region. In order to measure the environmental impacts at a lower level, with more detail, the metabolism of the construction sector, in 2001, has been accounted for (Chapter 5). As well as a method for the quantification for companies and industrial area's metabolism has been proposed (Chapter 6). The results show the efficiency in materials use but, at this level, the derived material indicators are combined with indicators of water and energy requirement. The analysis of the metabolism of construction sector illustrates that the main problem with this sector is the high volume of material used. The high consumption of resources in construction is directly related to the increase of material stock in Catalonia every year but, it also has a strong influence on the freight transport requirements and on the energy profile of the region. The results point out that an improvement in the efficiency in material's manufacturing is not enough for the region's dematerialisation. The increase in efficiency should be combined with the limitation of constructions activities, efforts in design to dematerialize constructions and the necessity to use the existing stock as a future material source. To complete the analysis of the metabolism of the region and the means to improve industrial sector the metabolism of an industrial area has been analysed (Chapter 6). Through a case study of an area located in Santa Perpetua de Mogoda, a methodology to quantify industrial's area metabolism is proposed. The methodology is analogous, consistent and comparable with the methods used for the other levels. The aim is to evaluate system's weak points and to quantify the improvements got through industrial symbiosis criteria. This analysis allows to evaluate a group of indicators which, when combined with other tools, could be useful to quantify the resource rate consumption and its consequences, to limit and to detect opportunities and weaknesses of the Catalan economic model

Ecological Changes in Lake Risten, Sweden, caused by Anthropogenic Influences - A Theoretical and Practical Study-

The ecological status in lake Risten, Sweden, is important in many ways. The lake is with its size a huge resource for recreation all around the year, since it provides good opportunities for activities like swimming, fishing and camping. Lake Risten is the first big lake in the river system downstream the deposits of the former copper mine in Bersbo, which has been affecting its downstream recipients over many years, although a very successful restoration was accomplished during 1987-1989. The fish from the lake is to a high extent used for consumption, and therefore comprehensive investigations has been necessary to check if the concentrations of metals in the fish are low enough not to make out a risk for human health when consuming it. It has been discovered, from a literature study, that the nutrient status of a lake is crucial for the uptake of metals in fish. Another problem in lake Risten, which has been more recently noticed by the local people, is an early stage of eutrophication. In the whole lake, but especially close to local nutrient sources from agriculture, an increase in under water vegetation and bottom sediment is occurring, which in turn is resulting in a change of habitats affecting the fauna of the lake. One species, which can be seriously affected by such a change, is the crayfish, and the fact is that the crayfish population has decreased over the last years. Whether the eutrophication is the main reason for the decrease or not cannot be stated without further investigations. This thesis is based on a combination of analysis of a thorough literature study and practical work, in form of water sampling for measuring of nutrient values in the inlet- and outlet streams of the lake and measurements of physical parameters of those streams. The report presents the situation in which the lake is found today and its history, but more importantly it presents how its ecological status could be improved in the future by application of suggested solutions. The results from the measurements can not give a totally accurate answer, but it can hopefully give an idea of the situation and tell if further investigations are needed or not

Análisis de los flujos de materiales de una región: Cataluña (1996-2000)

En este trabajo se presentan los resultados del Análisis de Flujos de Materiales entre los años 1996 y 2000 para el caso de Cataluña, una región situada en el noreste de España. Los resultados muestran un crecimiento de los indicadores de entrada de materiales y de consumo muy superior al crecimiento de la población y del Producto Interior Bruto, descartándose la posible tendencia a la desmaterialización absoluta o relativa, y mostrando un fuerte dominio de consumo de recursos no renovables. Asimismo se observa una gran dependencia del exterior, tanto en la entrada de recursos como en las exportaciones. Las importaciones aumentan a lo largo del periodo analizado, compensando la falta de recursos primarios del sistema. Parte de los materiales importados son exportados, mostrando Cataluña cómo una región de tránsito de mercancías, sometida a el Efecto Rótterdam. A la vez una fracción de las importaciones se revende con beneficio para Cataluña siguiendo el comportamiento propio de la zona alta de la curva del Notario.Análisis de flujos de materiales, escala regional, indicadores ambientales, Cataluña (España)

Thermal 3D CFD Simulation with Active Transparent Façade in Buildings

In recent years active façades have acquired greater importance given their capacity to improve the energy efficiency of buildings. One such type is the so-called Active Transparent Façade (ATF). A 3D numerical model based on computational fluid dynamics (CFD) and the Finite Element Method (FEM) has been generated to simulate the thermal performance of buildings equipped with this type of façade. This model is introduced for general application and allows the design parameters to be adapted for this system. The case study of Le Corbusier’s proposal for the City of Refuge in Paris, the clearest example of previous use of an ATF is examined. In addition, a proposal is presented for the energy improvement of Le Corbusier’s original solution. In order to do so, the conditions for the supply of air into the ATF cavity and in the mechanical ventilation system are assessed to guarantee comfort conditions

Thermal 3D CFD Simulation with Active Transparent Façade in Buildings

In recent years active façades have acquired greater importance given their capacity to improve the energy efficiency of buildings. One such type is the so-called Active Transparent Façade (ATF). A 3D numerical model based on computational fluid dynamics (CFD) and the Finite Element Method (FEM) has been generated to simulate the thermal performance of buildings equipped with this type of façade. This model is introduced for general application and allows the design parameters to be adapted for this system. The case study of Le Corbusier’s proposal for the City of Refuge in Paris, the clearest example of previous use of an ATF is examined. In addition, a proposal is presented for the energy improvement of Le Corbusier’s original solution. In order to do so, the conditions for the supply of air into the ATF cavity and in the mechanical ventilation system are assessed to guarantee comfort conditions

Evaluation of CupCarbon Network Simulator for Wireless Sensor Networks

[EN] Wireless sensor networks (WSNs) are a technology in continuous evolution with great future and a huge quantity of applications. The implementation and deployment of a WSN imply important expenses, so it is interesting to simulate the operation of our design before deploying it. In addition, WSNs are limited by a set of parameters such as the low processing capacity, low storing capacity or limited energy. Energy consumption is the most limiting parameter since the network stability and availability depends on the survival of the nodes. To check the correct operation of a network, currently, there are several network simulators and day by day new proposals are launched. This paper presents the evaluation of a new network simulator called CupCarbon. Along the document, we present the main characteristics of this simulator and check its operation by an example. To evaluate the ease of use of this new network simulator, we propose a modified version of Dijkstra algorithm. In addition of considering the cost route to calculate the best route, it considers the remaining energy in nodes as an additional parameter to evaluate the best route. CupCarbon allows implementing our proposal and the results show that our proposal is able to offer a more stable network with an increase of the network lifetime of the 20%. Finally, to extract some conclusions from our experiences, we compare the characteristics and results of CupCarbon with the most common network simulators currently used by researchers. Our conclusions point out that CupCarbon can be used as a complementary tool for those simulators that are not able to monitor the energy consumption in nodes. However, it needs some improvements to reach the level of functionality of the most used simulators. CupCarbon could be an interesting option for academic environments.López-Pavón, C.; Sendra, S.; Valenzuela-Valdés, JF. (2018). Evaluation of CupCarbon Network Simulator for Wireless Sensor Networks. Network Protocols and Algorithms. 10(2):1-27. https://doi.org/10.5296/npa.v10i2.13201S12710

Análisis de los flujos de materiales de una región : Cataluña (1996-2000)

En este trabajo se presenta una primera estimación del Análisis de Flujos de Materiales entre los años 1996 y 2000 para el caso de Cataluña, una región situada en el noreste de España. Los resultados muestran un crecimiento de los indicadores de entrada de materiales y de consumo muy superior al crecimiento de la población y del Producto Interior Bruto, descartándose la posible tendencia a la desmaterialización absoluta o relativa, y mostrando un fuerte dominio de consumo de recursos no renovables. Asimismo se observa una gran dependencia del extrior, tanto en la entrada de recursos como en las exportaciones. Las importaciones aumentan a lo largo del período analizado, cpmensando la falta de recursos primarios del sistema. Parte de los materiales importados son exportados, mostrando Cataluña como una región de tránsito de mercancías, sometida al Efecto Rótterdam. A la vez una fracción de las importaciones se revende con beneficio para Cataluña siguiendo el comportamiento propio de la zona alta de la curva del Notario.The paper presents the Material Flow Analysis for Catalonia (NE Spain) in the period 1996 - 2000. The results show no symptom of neither weak nor strong dematerialization, otherwise the increase in material inputs and consumption a long the period is higher than population and GDP growth; with dominance of non-renewable resources. There is a high dependence on foreign trade. On one hand, imports has increased a long the period analyzed to compensate the lack of primary resources in the own system. On the other hand, the price of exports is higher than imports, supposing important economic input for Catalonia

Objetos y materiales en la escuela infantil: historias que se recogen, se viven y se inician

En este trabajo intentamos mostrar el aula de educación infantil como un espacio y un tiempo de historias que se recogen, se viven y se inician. El texto es fruto del estudio que hemos realizado en una escuela pública de una población cercana a la ciudad de Valencia. Es una escuela peculiar pues está en un paraje natural, donde el tiempo parece desacelerarse. Durante dos cursos hemos acompañado a las maestras y a las criaturas en dos aulas de 5 y 3 años respectivamente. Nuestra investigación de carácter narrativo explora, desde distintos puntos de vista, los procesos de creación curricular que observábamos en las aulas. En nuestra práctica de observación recogemos hilos con los que enlazar historias que nos muestran cómo el currículum se va creando en la escuela. En este texto exploraremos uno de esos hilos de nuestro estudio: el papel que los materiales tienen en la vida del aula, cómo determinados objetos (libros, elementos naturales, fotografías ) conectan la vida del aula con la vida de las niñas y los niños y sus historias familiares, y cómo cuando las maestras acogen estos materiales y les hacen espacio, aparecen nuevas historias para vivirse desde ellas. In this paper we aim to present the early childhood education classroom as a space and a time of collected, lived, and prompted stories. This text is the result of a study conducted in a state school located in a village near Valencia. It is a singular school, for it is situated in a nature park, where time seems to decelerate. For two school years, we have been alongside teachers and children in two classrooms of ages 5 and 3 respectively. Our investigation - which is of narrative character - explores from diff erent points of view the curriculummaking processes observed in the classrooms. In our observation practice, we gather threads with which to connect stories that show how the curriculum is created within the school. In this paper we will explore one of these threads of our study: the role materials play in the life of the classroom, the way in which certain objects (books, natural elements, photographs ) connect the life of the classroom to the life of the children and their family stories, and how, when teachers embrace these materials and give them a space, new stories to be experienced spring u

Naturaleza, saber y narrativa. A la búsqueda de una relación sensible con el mundo natural y con el saber

La experiencia de investigación que presentamos a continuación nos ha permitido estar juntas en un aula universitaria, una como docente y la otra como observadora; estar en una escuela junto con las maestras, los niños y las niñas; y acercarnos a las aulas universitarias y escolares con una mirada narrativa. En este trabajo mostramos una pequeña parte de esta investigación, una parte que comienza con un itinerario didáctico-natural que organizamos junto con los y las estudiantes de los grados de maestro y maestra en educación infantil y primaria. Lo ocurrido durante este itinerario nos hizo preguntarnos sobre la relación con el mundo (en este caso con el mundo natural) que estábamos promoviendo como docentes y sobre la conexión existente entre nuestra relación con el mundo y nuestra relación con el saber. Las maestras, los niños y las niñas también nos han ayudado a profundizar en estas preguntas. Este trabajo incluye tres relatos de experiencia fruto de esta exploración narrativa en la universidad y en la escuela: la historia del itinerario didáctico-natural y las historias que cuentan cómo las niñas y los niños acumulaban piedras y conchas en la playa y cómo cuidaban y protegían los pinos y los pequeños animales del bosque. Relatos que ponen de relieve la existencia de una conexión entre establecer una relación cuidadosa con el mundo natural y cultivar una relación curiosa y libre con el saber. Asimismo, relatos que nos han hecho conscientes de la importancia de las condiciones que somos capaces de generar como docentes -el tiempo y el espacio que habitamos, los materiales que ofrecemos como mediación- para favorecer, aunque sin garantizar, un tipo de relación con el saber y con el mundo más cuidadosa y libre