11 resultados para Best-seller
em Universidad Politécnica de Madrid
Resumo:
Uno de los objetivos del Proyecto europeo NURISP (NUclear Reactor Integrated Platform) del 7º Programa Marco es avanzar en la simulación de reactores de agua ligera mediante el acoplamiento de códigos best-estimate que profundicen en la física de núcleo, termohidráulica bifásica y comportamiento del combustible [1]. Uno de estos códigos es COBAYA3, código de difusión 3D en multigrupos pin-by-pin desarrollado en la UPM, que requiere de librerías de secciones eficaces homogeneizadas a nivel de la barrita de combustible.
Resumo:
The challenge to properly feed a world population of 9.2 billion by 2050, that must be achieved on essentially currently cropped area, requires that food production be increased by 70%. This large increase can only be achieved by combinations of greater crop yields and more intensive cropping adapted to local conditions and availability of inputs. Farming systems are dynamic and continuously adapt to changing ecological, environmental and social conditions, while achieving greater production and resource-use efficiency by application of science and technology. This article argues that the solution to feed and green the world in 2050 is to support this evolution more strongly by providing farmers with necessary information, inputs, and recognition. There is no revolutionary alternative. Proposals to transform agriculture to low-input and organic systems would, because of low productiv- ity, exacerbate the challenge if applied in small part, and ensure failure if applied more widely. The challenge is, however, great. Irrigation, necessary to increase cropping intensity in many areas cannot be extended much more widely than at present, and it is uncertain if the current rate of crop yield increase can be maintained. Society needs greater recognition of the food-supply problem and must increase funding and support for agricultural research while it attends to issues of food waste and over consumption that can make valuable reductions to food demand from agriculture
Resumo:
Steam Generator Tube Rupture (SGTR) sequences in Pressurized Water Reactors are known to be one of the most demanding transients for the operating crew. SGTR are a special kind of transient as they could lead to radiological releases without core damage or containment failure, as they can constitute a direct path from the reactor coolant system to the environment. The first methodology used to perform the Deterministic Safety Analysis (DSA) of a SGTR did not credit the operator action for the first 30 min of the transient, assuming that the operating crew was able to stop the primary to secondary leakage within that period of time. However, the different real SGTR accident cases happened in the USA and over the world demonstrated that the operators usually take more than 30 min to stop the leakage in actual sequences. Some methodologies were raised to overcome that fact, considering operator actions from the beginning of the transient, as it is done in Probabilistic Safety Analysis. This paper presents the results of comparing different assumptions regarding the single failure criteria and the operator action taken from the most common methodologies included in the different Deterministic Safety Analysis. One single failure criteria that has not been analysed previously in the literature is proposed and analysed in this paper too. The comparison is done with a PWR Westinghouse three loop model in TRACE code (Almaraz NPP) with best estimate assumptions but including deterministic hypothesis such as single failure criteria or loss of offsite power. The behaviour of the reactor is quite diverse depending on the different assumptions made regarding the operator actions. On the other hand, although there are high conservatisms included in the hypothesis, as the single failure criteria, all the results are quite far from the regulatory limits. In addition, some improvements to the Emergency Operating Procedures to minimize the offsite release from the damaged SG in case of a SGTR are outlined taking into account the offsite dose sensitivity results.
Resumo:
En el siglo pasado la comunidad internacional comenzó un período de reflexión relacionado con los problemas ambientales de nuestro planeta, que ha llegado hasta hoy, situándose en el centro de discusión el problema del cambio limático. El modelo territorial impuesto ha contribuido notablemente al aumento del problema, teniendo como principal exponente el modelo de ordenación territorial y urbana. Gran parte de la transformación está en poder de los municipios, que tienen la responsabilidad de modificar el diseño y gestión de las áreas urbanas, así como del desarrollo y ejecución de políticas públicas para enfrentarnos a estos desafíos. Los programas presentados por los gobiernos nacionales o las agencias de la UE, pueden parecer ajenos o de difícil gestión por los municipios, pero en realidad sus atribuciones son adecuadas para atender a las realidades territoriales y además, de mayor comprensión por los ciudadanos.
Resumo:
A membrane system is a massive parallel system, which is inspired by the living cells when processing information. As a part of unconventional computing, membrane systems are proven to be effective in solving complex problems. A new factor is introduced. This factor can decide whether a technique is worthwhile being used or not. The use of this factor provides the best chances for selecting the strategy for the rules application phase. Referring to the “best” is in reference to the one that reduces execution time within the membrane system. A pre-analysis of the membrane system determines the P-factor, which in return advises the optimal strategy to use. In particular, this paper compares the use of two strategies based on the P-factor and provides results upon the application of them. The paper concludes that the P-factor is an effective indicator for choosing the right strategy to implement the rules application phase in membrane systems.
Resumo:
In Chile, during the last three decades there has been a strong decentralization process whose main objective has been to improve the management of schools through the transfer of responsibilities and resources of education and thus improve the outcome of learning, reducing equity gaps between schools and territories. This is how, there has been an evolution of school principals¿ professional profile from an administrative to a management approach, in which principals have become project managers of educational projects. From a competence model for school leaders, based on IPMA guidelines, the present article presents an analysis of best practices for school management, allowing to generate a link between competencies and school management, from the perspective of project management. Results showed that the different competence elements, have relative weights according to the different practice fields, and that this analysis can be considered as a strategic element in educational project planning and development.
Resumo:
In Chile, during the last three decades there has been a strong decentralization process whose main objective has been to improve the management of schools through the transfer of responsibilities and resources of education and thus improve the outcome of learning, reducing equity gaps between schools and territories. This is how, there has been an evolution of school principals¿ professional profile from an administrative to a management approach, in which principals have become project managers of educational projects. From a competence model for school leaders, based on IPMA guidelines, the present article presents an analysis of best practices for school management, allowing to generate a link between competencies and school management, from the perspective of project management. Results showed that the different competence elements, have relative weights according to the different practice fields, and that this analysis can be considered as a strategic element in educational project planning and development.
Resumo:
The simulation of design basis accidents in a containment building is usually conducted with a lumped parameter model. The codes normally used by Westinghouse Electric Company (WEC) for that license analysis are WGOTHIC or COCO, which are suitable to provide an adequate estimation of the overall peak temperature and pressure of the containment. However, for the detailed study of the thermal-hydraulic behavior in every room and compartment of the containment building, it could be more convenient to model the containment with a more detailed 3D representation of the geometry of the whole building. The main objective of this project is to obtain a standard PWR Westinghouse as well as an AP1000® containment model for a CFD code to analyze the thermal-hydraulic detailed behavior during a design basis accident. In this paper the development and testing of both containment models is presented.
Resumo:
The objective of the project is the evaluation of the code STAR-CCM +, as well as the establishment of guidelines and standardized procedures for the discretization of the area of study and the selection of physical models suitable for the simulation of BWR fuel. For this purpose several of BFBT experiments have simulated provide a data base for the development of experiments for measuring distribution of fractions of holes to changes in power in order to find the most appropriate models for the simulation of the problem.
Resumo:
The W3C Best Practises for Multilingual Linked Open Data community group was born one year ago during the last MLW workshop in Rome. Nowadays, it continues leading the effort of a numerous community towards acquiring a shared view of the issues caused by multilingualism on the Web of Data and their possible solutions. Despite our initial optimism, we found the task of identifying best practises for ML-LOD a difficult one, requiring a deep understanding of the Web of Data in its multilingual dimension and in its practical problems. In this talk we will review the progresses of the group so far, mainly in the identification and analysis of topics, use cases, and design patterns, as well as the future challenges.
Resumo:
El espejismo de un problema arquitectónico: sobre la exposición «Buildings for Best Products» en el MOMA de Nueva York