11 resultados para Petrus Lombardus, Bishop of Paris, 12th century.
em Universidad Politécnica de Madrid
Resumo:
In this paper we report the process of designing and building the EYEFLY 1, a real UAS platform which has just performed its maiden flight. For the development of this aircraft, 30 groups of students from successive years at the Escuela Universitaria de Ingeniería Técnica Aeronáutica (EUITA) of the Universidad Politécnica de Madrid (UPM) carried out their compulsory End of Degree Project as a coordinated Project Based learning activity. Our conclusions clearly indicate that Project Based Learning activities can provide a valid complement to more conventional, theoretically-based, teaching methods. The combination of both approaches will allow us to maintain traditional but well-tested methods for providing our students with a sound knowledge of fundamental engineering disciplines and, at the same time, to introduce our students to exciting and relevant engineering situations and sceneries where social and business skills, such as communication skills, team-working or decision-taking, can be put into practice.
Resumo:
The analysis of how tourists select their holiday destinations along with the factors determining their choices is very important for promoting tourism. In particular, transportation is supposed to have a great influence on the tourists’ decisions. The aim of this paper is to investigate the role of High Speed Rail (HSR) systems with respect to a destination choice. Two key tourist destinations in Europe namely Paris, and Madrid, have been chosen to identify the factors influencing this choice. On the basis of two surveys to obtain information from tourists, it has been found that the presence of architectural sites, the promotion quality of the destination itself, and the cultural and social events have an impact when making a destination choice. However the availability of the HSR systems affects the choice of Paris and Madrid as tourist destinations in a different way. For Paris, TGV is considered a real transport mode alternative among tourists. On the other hand, Madrid is chosen by tourists irrespective of the presence of an efficient HSR network. Data collected from the two surveys have been used for a further quantitative analysis. Regression models have been specified and parameters have been calibrated to identify the factors influencing holidaymakers to revisit Paris and Madrid and visit other tourist places accessible by HSR from these capitals
Resumo:
Análisis de la teoría y práctica de la restauración en Inglaterra en la segunda mitad del siglo XIX, enfocada al trabajo realizado por el arquitecto George Edmund Street, desde el punto de vista de su investigación sobre la historia de la construcción de la arquitectura gótica en Europa.
Resumo:
The competition in markets, the distribution of limited resources based on productivity and performance, and the efficient management of universities are changing the criteria of trust and legitimacy of the educational system in Peru. Universities are perceived more as institutions of the public sector, while the services they offer must rather contribute to the modernization of the emerging society and the knowledge economy. Higher Educations reforms - initiated in the 1980s - have been inspired by the successful university organizations that have managed to change their governance and addressed to transform certain bureaucratic institutions into organizations capable of playing active role in this global competition for resources and best talent. Within this context, Peruvian universities are facing two major challenges: adapting themselves to new global perspectives and being able to develop a better response to society demands, needs and expectations. This article proposes a model of governance system for higher education in Peru that gives a comprehensive solution to these challenges, allowing dealing with the problems of universities for their development and inclusion within the global trends. For this purpose, a holistic and qualitative methodologic approach was developed, considering an integrated method which considered educational reality as a whole, understanding its facts, components and elements that affects its outcomes. It is proposed to define a policy for university education in Peru that permeates society, by changing the planning model from a social reform model to a policy analysis model, where the Peruvian State acts as sole responsible for responding to the demanding society as its legal representative complemented with some external and independent bodies that define the basis of best practice, as it is being done in many university models worldwide.
Resumo:
As a result of the variscan collision, several allochtonous complexes were emplaced on the Iberian margin in Devonian times, among them the Cabo Ortegal Complex comprising the Moeche ophiolitic sequence. Copper has been won from several mines (Piquitos I & II, Barqueira, Maruxa) from disseminated ores and thin massive sulphide layers in the Moeche Unit, a strongly deformed meta-volcanic sequence comprising mainly quartz-chlorite schists and mylonites, which defines the top of the ophiolite. The ores were metamorphosed and strongly deformed under brittle conditions (for pyrite), but their textures are often apparently post-deformational, due to very common solution-transfer processes; they are composed mostly of pyrite and chalcopyrite, with minor sphalerite, pyrrhotite, etc., and with traces of native gold and PGE. The geology, mineralogy, and geochemistry of the orebodies relate closely to VMS of the Cu-Zn (Cyprus) type. Fluid inclusion studies allowed an estimation of metamorphic conditions at pressures of 2/2’5 kb and T 325/350ºC. New determinations using the chlorite geothermometer yield temperatures around 320 ºC, corresponding to pressures near 2 kb according to the isochores deduced from the fluid inclusion study, although in the Barqueira mine higher temperatures, up to 350 ºC, are found, corresponding to presssures up to 2’5 kb. Pb isotopic compositions of pyrite point to a double source of Pb, i.e. a main mantle and a subordinate crustal source. The values for 87SR/86Sr in pyrite support this interpretation, but some results suggest later mobilization in an open system, corresponding to solution-transfer. Age determinations of pyrite deduced from the Pb isotope uranogenic graph, ≈ 480 Ma, do not fit with the metamorphic ages published for the Moeche Unit, and might point to the age of Pb extraction from the mantle.
Resumo:
Mining in the Iberian Pyrite Belt (IPB), the biggest VMS metallogenetic province known in the world to date, has to face a deep crisis in spite of the huge reserves still known after ≈5 000 years of production. This is due to several factors, as the difficult processing of complex Cu-Pb-Zn-Ag- Au ores, the exhaustion of the oxidation zone orebodies (the richest for gold, in gossan), the scarce demand for sulphuric acid in the world market, and harder environmental regulations. Of these factors, only the first and the last mentioned can be addressed by local ore geologists. A reactivation of mining can therefore only be achieved by an improved and more efficient ore processing, under the constraint of strict environmental controls. Digital image analysis of the ores, coupled to reflected light microscopy, provides a quantified and reliable mineralogical and textural characterization of the ores. The automation of the procedure for the first time furnishes the process engineers with real-time information, to improve the process and to preclude or control pollution; it can be applied to metallurgical tailings as well. This is shown by some examples of the IPB.
Resumo:
3D Modular construction is poorly known and scarcely published in technical literature. In spite of that there are an increasing number of manufacturers offering their products in different countries. This method has largely evolved from early examples such as the American Gold Rush prefabrication in the nineteenth century, the Sears precut homes or Voisin´s prototypes for modular homes, to the end of the first half of the twentieth century. In this period a non negligible number of attempts in 3D modular construction have been carried out, ranging from theoretical proposals to several hundred or thousand units produced. Selected examples of modular architecture will be analyses in order to illustrate its technical evolution, concerning materials, structure, transportation and on site assembly. Success and failure factors of the different systems will be discussed. Conclusions about building criteria shown in them and their applicability in current architecture will be drawn.
Resumo:
The CENTURY soil organic matter model was adapted for the DSSAT (Decision Support System for Agrotechnology Transfer), modular format in order to better simulate the dynamics of soil organic nutrient processes (Gijsman et al., 2002). The CENTURY model divides the soil organic carbon (SOC) into three hypothetical pools: microbial or active material (SOC1), intermediate (SOC2) and the largely inert and stable material (SOC3) (Jones et al., 2003). At the beginning of the simulation, CENTURY model needs a value of SOC3 per soil layer which can be estimated by the model (based on soil texture and management history) or given as an input. Then, the model assigns about 5% and 95% of the remaining SOC to SOC1 and SOC2, respectively. The model performance when simulating SOC and nitrogen (N) dynamics strongly depends on the initialization process. The common methods (e.g. Basso et al., 2011) to initialize SOC pools deal mostly with carbon (C) mineralization processes and less with N. Dynamics of SOM, SOC, and soil organic N are linked in the CENTURY-DSSAT model through the C/N ratio of decomposing material that determines either mineralization or immobilization of N (Gijsman et al., 2002). The aim of this study was to evaluate an alternative method to initialize the SOC pools in the DSSAT-CENTURY model from apparent soil N mineralization (Napmin) field measurements by using automatic inverse calibration (simulated annealing). The results were compared with the ones obtained by the iterative initialization procedure developed by Basso et al., 2011.
Resumo:
The analysis of how tourists select their holiday destinations along with the factors that determine their choices is very important for promoting tourism. In particular, transportation is supposed to have influence on tourists? decissions. The objective of this paper is to investigate more especifically the role of High Speed Rail (HSR) in this choice. Two key tourist destinations in Europe, Paris and Madrid, have been chosen to understand the factors influencing this choice. On the basis of a survey conducted to tourists, we found out that some aspects such as the presence of architectural sites, the quality of promotion of the destination itself, and cultural and social events, have an impact on their choice. However the presence of the HSR system affects the choice of Paris and Madrid as a touristic destination in a different way. For Paris, TGV is considered a real transport mode alternative among tourists who use it quite often. On the other hand, Madrid is chosen by tourists irrespective of the presence of an efficient HSR network. Data collected from the two surveys have been used for a further quantitative analysis. Regression models have been specified and parameters have been calibrated to identify the factors influencing holidaymakers to revisit Paris and Madrid and visit other touristic spots accesible from HSR from these cities.
Resumo:
Quercus pyrenaica es una especie rebrotadora de raíz intensa e históricamente aprovechada en monte bajo para la obtención de leñas, carbón y pastos. Debido al éxodo rural y a la aparición de nuevas fuentes energéticas, este aprovechamiento fue abandonado en la década de 1970. Desde entonces, las bajas producciones de madera y bellota y el puntisecado de los pies evidencian el generalizado estancamiento de estas masas. Uno de los mayores retos actuales de la selvicultura en el ámbito mediterráneo es encontrar usos alternativos para estos montes abandonados, siendo la conversión a monte alto una de las alternativas preferidas. Se han realizado resalveos de conversión, sin embrago, éstos se aplican sin un conocimiento integral de las causas de la degradación. En esta tesis doctoral, estudiamos un hipotético desequilibrio entre la parte radical y la parte aérea (R:S) de las cepas de rebollo como causa subyacente de su decaimiento. En una parcela experimental, aprovechada al menos desde el siglo XII, se realizaron análisis genéticos a priori para elucidar la estructura genética del rodal, y así estudiar la influencia del tamaño clonal en el funcionamiento de las cepas. Las cepas de mayor tamaño presentaron un menor crecimiento diametral de sus pies, así como mayores tasas de respiración radical, estimadas a partir de flujos internos de CO2 a través del xilema (FT) y de los flujos de CO2 del suelo. Estos resultados sugieren que el desequilibrio R:S aumenta con el tamaño clonal, dado que la eliminación periódica de órganos aéreos, al mismo tiempo que las raíces permanecen intactas, da lugar a un gran desarrollo del sistema radical que consume gran parte de los carbohidratos no estructurales (NSC) en respiración de mantenimiento, comprometiendo así el desarrollo de órganos aéreos. Se excavaron y pesaron dos cepas compuestas por cuatro y ocho pies, las cuales mostraron ratios R:S (0.5 y 1, respectivamente) superiores a los registrados en pies de origen sexual. Al igual que en otras especies rebrotadoras de raíz, se observaron altas concentraciones de NSC en las raíces (> 20% en primavera) y una gran proporción de albura en el sistema radical (52%) que alberga una notable reserva de NSC (87 kg en la cepa de mayor tamaño). En el sistema radical de dicha cepa, estimada mediante dataciones radiocarbónicas en 550 años de edad, se contaron 248 uniones radicales. La persistencia de sistemas radicales grandes, viejos, y altamente interconectados sugiere que la gran cantidad de recursos almacenados y consumidos en las raíces compensan un pobre desarrollo aéreo con una alta resiliencia vegetativa. Para un mejor entendimiento de los balances de carbono y del agotamiento de NSC en las cepas de rebollo, se midieron los flujos internos y externos de CO2 en troncos y los flujos de CO2 del suelo, y se estimó la respiración de órganos aéreos (RS) y subterráneos (RR). Estacionalmente, RS y RR reflejaron las dinámicas de flujo de savia y de crecimiento del tronco, y estuvieron determinadas principalmente por los flujos externos de CO2, dada la escasa contribución de FT a RS y RR (< 10% y < 2%, respectivamente). En una escala circadiana, la contribución de FT a RS aumentó hasta un 25% en momentos de alta transpiración. Las bajas concentraciones de CO2 en el xilema ([CO2] hasta un 0.11%) determinaron comparativamente unos bajos FT, probablemente causados por una limitada respiración del xilema y una baja resistencia a la difusión radial del CO2 impuestos por la sequía estival. Los pulsos de [CO2] observados tras las primeras lluvias de otoño apoyan esta idea. A lo largo del periodo vegetativo, el flujo medio de CO2 procedente del suelo (39 mol CO2 day-1) fue el mayor flujo respiratorio, tres y cuatro veces superior a RS (12 mol CO2 day-1) y RR (8-9 mol CO2 day-1), respectivamente. Ratios RR/RS menores que la unidad evidencian un importante peso de la respiración aérea como sumidero de carbono adicional. Finalmente, se ensayó el zanjado de raíces y el anillamiento de troncos como tratamientos selvícolas alternativos con el objetivo de aumentar las reservas de NSC en los troncos de las cepas. Los resultados preliminares desaconsejan el zanjado de raíces por el alto coste derivado posiblemente de la cicatrización de las heridas. El anillado de troncos imposibilitó el transporte de NSC a las raíces y aumentó la concentración de almidón por encima de la zona anillada, mientras que sistema radical se mantiene por los pies no anillados de la cepa. Son necesarias más mediciones y datos adicionales para comprobar el mantenimiento de esta respuesta positiva a largo plazo. Para concluir, destacamos la necesidad de estudios multidisciplinares que permitan una comprensión integral de la degradación de los rebollares ibéricos para poder aplicar a posteriori una gestión adecuada en estos montes bajos abandonados. ABSTRACT Quercus pyrenaica is a vigorous root-resprouting species intensively and historically coppiced for firewood, charcoal and woody pastures. Due to the rural exodus and the appearance of new energy sources, coppicing was abandoned towards 1970. Since then, tree overaging has resulted in stand stagnation displayed by slow stem growth, branch dieback, and scarce acorn production. The urgent need to find new alternative uses for abandoned coppices is recognized as one of the biggest challenges which currently faces Mediterranean silviculture; conversion into high forest by thinning is one of the preferred alternatives. For this aim, thinning has been broadly applied and seldom tested, although without a comprehensive understanding of the causes of stand stagnation. In this PhD study, we test the hypothesis of an imbalance between above- and below-ground organs, result of long term coppicing, as the underlying cause of Q. pyrenaica decay. In an experimental plot coppiced since at least the 12th century, genetic analyses were performed a priori to elucidate inconspicuous clonal structure of Q. pyrenaica to evaluate how clonal size affects the functioning of these multi-stemmed trees. Clonal size negatively affected diametric stem growth, whereas root respiration rates, measured by internal fluxes of CO2 through xylem (FT) and soil CO2 efflux, increased with clonal size. These results suggest root-to-shoot (R:S) imbalance intensifying with clonal size: periodic removal of aboveground organs whilst belowground organs remain undisturbed may have led to massive root systems which consume a great proportion of non-structural carbohydrates (NSC) for maintenance respiration, thus constraining aboveground performance. Furthermore, excavation of two multi-stemmed trees, composed by four and eight stems, revealed R:S ratios (0.5 and 1, respectively) greater than those reported for sexually regenerated trees. Moreover, as similarly observed in several root-resprouting species, NSC allocation to roots was favored ([NSC] > 20% in spring): a large proportion of sapwood maintained throughout the root system (52%) stored a remarkable NSC pool of 87 kg in the case of the largest clone. In this root system of the eight-stemmed tree, 248 root connections were counted and, by radiocarbon dating, its age was estimated to be 550-years-old. Persistence of massive, old and highly interconnected root systems suggests that enhanced belowground NSC storage and consumption reflects a trade-off between vegetative resilience and aboveground development. For a better understanding of tree carbon budget and the potential role of carbon starvation in Q. pyrenaica decay, internal and external stem CO2 fluxes and soil CO2 effluxes were monitored to evaluate respiratory costs above- and below-ground. On a seasonal scale, stem and root respiration (RS and RR) mirrored sap flow and stem growth dynamics. Respiration was determined to the greatest extent by external fluxes of CO2 to the atmosphere or soil, since FT accounted for a low proportion of RS and RR (< 10% and < 2%, respectively). On a diel scale, the contribution of FT to RS increased up to 25% at high transpiration rates. Comparatively low FT was determined by the low concentration of xylem CO2 registered ([CO2] as low as 0.11%), likely as a consequence of constrained xylem respiration and reduced resistance to CO2 radial diffusion imposed by summer drought. Xylem [CO2] pulses following first autumn rains support this idea. Averaged over the growing season, soil CO2 efflux was the greatest respiratory flux (39 mol CO2 day-1), three and four times greater than RS (12 mol CO2 day-1) and RR (8-9 mol CO2 day-1), respectively. Ratios of RR/RS below one evidence an additional and important weight of aboveground respiration as a tree carbon sink. Finally, root trenching and stem girdling were tested as complimentary treatments to thinning as a means to improve carbon reserves in stems of clonal trees. Preliminary results discouraged root trenching due to the high cost likely incurred for wound closure. Stem girdling successfully blocked NSC translocation downward, increasing starch concentrations above the girdled zone whilst the root system is fed by non-girdled stems within the clone. Further measurements and ancillary data are necessary to verify that this positive effect hold over time. To conclude, the need of multidisciplinary approaches for an integrative understanding on the functioning of abandoned Q pyrenaica coppices is highlighted for an appropriate management of these stands.
Resumo:
Uno de los capítulos más interesantes del gótico europeo lo constituyen las bóvedas sexpartitas, sin lugar a dudas una de las bóvedas más singulares jamás creadas dentro de este estilo. Las primeras bóvedas góticas, en cruce de ojivas y de planta cuadrada, limitaban su uso a espacios relativamente pequeños, pero ante la necesidad de cubrir espacios de considerables dimensiones, apareció una nueva bóveda de características muy peculiares; la sexpartita. Esta bóveda en cruce de ojivas está reforzada por el centro con un arco paralelo a los arcos fajones que la divide por la mitad y que fragmenta el arco formero en dos, creando una pareja de ventanales en cada lado. La sencilla superficie en bóveda de arista, en el origen de las bóvedas de crucería, se complica extraordinariamente creando una volumetría de gran complejidad con seis cuarteles de plementería y con seis apoyos de distinto tamaño, cuatros esquineros y dos centrales más pequeños. Las dificultades que implica la construcción de este tipo de bóvedas explican quizás su abandono prematuro y la vuelta a la bóveda de crucería simple, ahora de tramos rectangulares. No obstante, a pesar de su corta existencia, la bóveda sexpartita fue la gran protagonista de los inicios del gótico y con ella se llevaron a cabo importantes abovedamientos, desde Inglaterra hasta Rumanía. La disciplina de la Historia de la Construcción se vio extraordinariamente favorecida por los estudios realizados en el siglo XIX, sin embargo su investigación se abandona durante el siglo XX para ser recuperada recientemente. Viollet-le-Duc, a finales del s. XIX, hace una sucinta explicación de este tipo de bóvedas. También Auguste Choisy, más tarde, dedica unas páginas a la bóveda sexpartita francesa; desde entonces, este tema, ha merecido escasísimas referencias en los estudios posteriores. Esta investigación se enmarca en este contexto y pretende poner de manifiesto los conocimientos geométricos y constructivos que hicieron posible la realización de las bóvedas sexpartitas europeas. Para ello se ha llevado a cabo la investigación de las principales bóvedas en Europa occidental; Francia, España, Inglaterra, Alemania, Suiza e Italia. Su estudio comparativo nos ha permitido poner de manifiesto sus características constructivas comunes y aquellos aspectos propios de cada país, así como algunos de los canales de comunicación que permitieron la expansión de esta arquitectura. Las nuevas tecnologías de medición, el escáner láser, la estación total, la fotogrametría, etc., han supuesto una revolución para la documentación y restauración del Patrimonio y un salto cualitativo formidable para el análisis de las bóvedas góticas, permitiendo estudios de la arquitectura histórica hasta ahora inabordables. Para realizar el análisis de las bóvedas sexpartitas europeas se ha llevado a cabo un levantamiento exhaustivo de las mismas, lo que ha permitido definir su despiece, obteniendo la forma de la talla de cada uno de los elementos constructivos que la componen; jarjas, dovelas, claves y plementería. La obtención de estos datos nos ha permitido abordar un profundo estudio de su estereotomía y construcción, aportando datos inéditos hasta el momento. Por otro lado se ha llevado a cabo la detección y catalogación de las principales bóvedas sexpartitas que aún se conservan en Europa. Los estudios realizados nos permiten afirmar que la bóveda sexpartita surge en Francia en la segunda mitad del siglo XII, utilizándose en las principales catedrales francesas, como Notre Dame de Paris, Bourges o Laon. A comienzos del siglo XIII cae en desuso en Francia y comienza su expansión por el resto de Europa, donde se abandona medio siglo después, desapareciendo definitivamente del gótico europeo. Mientras que los ejemplos que datan del siglo XII muestran soluciones escasamente desarrolladas y propias del románico, las bóvedas construidas en el siglo XIII muestran soluciones enormemente complejas, con grandes jarjamentos e inteligentes estrategias constructivas y geométricas que permiten la simplificación de sus estructuras auxiliares y una mayor libertad en su diseño. Estas bóvedas son el reflejo del desarrollo de la estereotomía gótica en sus comienzos por lo que su estudio nos ha permitido conocer el desarrollo y la evolución del gótico primitivo en Europa. ABSTRACT One of the most interesting chapters of European Gothic is the sexpartite vault, without doubt one of the most remarkable vaults ever created within this style. The first Gothic vaults, with crossed ribs on a square base, were restricted to relatively small areas, but a new vault, with very particular characteristics emerged to address the need to cover spaces of considerable size; the sexpartite vault. This cross-ribbed vault is reinforced in the centre by an arch that runs parallel to the transverse arches, divides the vault in half and splits the wall arch in two, creating a pair of windows, one on each side. The simple groin vault surface, the source of ribbed vaults, was greatly complicated creating a highly complex volume with six sections of severies and with six supports of different sizes, four on the corners and two smaller central ones. The construction difficulties involved in building this type of vault may explain its premature abandonment and a return to the simple cross-ribbed vault, now in rectangular sections. However, despite its brief existence, the sexpartite vault was the great protagonist of the beginnings of Gothic architecture and important vaulting was built using this system from England to Romania. Studies undertaken in the 19th century helped the History of Construction as a discipline tremendously. Research was abandoned during the twentieth century however, and has only recently been taken up again. Towards the end of the 19th century, Viollet-le-Duc gave a brief description of this type of vault. Later, Auguste de Choisy also devoted some pages to the French sexpartite vault; since then, later studies have made very few references to it. Against this background, this research now attempts to bring to light the knowledge of geometry and construction that made the construction of the European sexpartite vault possible. To this end, the main vaults in Western Europe - France, Spain, England, Germany, Switzerland and Italy, have been studied. By making a comparative study we have been able to reveal the common construction features and those that are specific to each country, as well as some of the channels of communication that enabled this architecture to spread. New measuring technologies, the laser scanner, total station, photogrammetry, etc., have given rise to a revolution in heritage documentation and restoration, as well as facilitating a huge qualitative leap for the analysis of Gothic vaults, enabling studies of historical architecture that until now were inaccessible. A comprehensive survey was carried out to be able to analyse European sexpartite vaults. We could thus create an exploded view, which enabled us to obtain the form of each of the elements; tas-de-charges, voussoirs, keystones and severies. The data gathered provided previously unknown facts that enabled us to make an in-depth study of stereotomy and construction. Furthermore, the main sexpartite vaults still preserved in Europe have been identified and categorised. The studies undertaken allowed us to affirm that the sexpartite vault appeared in France in the second half of the twelfth century, being used in the main French cathedrals, such as Notre Dame de Paris, Bourges or Laon. At the beginning of the thirteenth century it fell into disuse in France and began to expand throughout the rest of Europe, where it was abandoned half a century later, disappearing from European Gothic for good. While the examples dating back to the 12th century display poorly developed solutions more characteristic of the Romanesque, the vaults built in the 13th century reveal enormously complex solutions, with large tas-de-charges and intelligent construction and geometric strategies that allowed auxiliary support structures to be simplified, and gave more freedom to design. These vaults reflect the beginnings of Gothic stereotomy and by studying them we have been able to learn more about the development and evolution of Early Gothic architecture in Europe.