El laboratori informàtic a l'aula. L'Interactive Physics, fent servir el canó de projecció, una bona eina per ensenyar física

Les simulacions són un recurs informàtic que ajuda en la tasca docent, però ens trobem amb la dificultat que suposa aplicar una tecnologia amb la que no estem familiaritzats. El que proposo és una metodologia per utilitzar les simulacions IP a l'aula convencional, de manera que no impliqui l'ús d'altres espais

DG-XFEM formulation for the unsteady incompressible Navier-Stokes equations

This Thesis proposes a combined formulation of the Discontinuous Galerkin Method (DG) with solenoidal basis functions and the eXtended Finite Element Method (XFEM), in order to solve the incompressible Navier-Stokes equations for unsteady flows around a solid object, providing high orders of accuracy in space and time. This DG-XFEM formulation simplifies the meshing process using structured meshes that also do not need to be updated at every time step if the object moves, reducing the computational cost. In the DG-XFEM formulation a fixed structured mesh is used and its elements are classified in three groups, which receive a different treatment. First, the elements inside the solid object are excluded in the calculations since it is treated as a void. Second, the elements belonging to the fluid are calculated as in the DG solenoidal formulation. Third, for the elements cut by the interface integration is modified using XFEM in order to take into account only the fluid region, considering curved integration cells to accurately compute integrals in high-order elements; straight afterwards it is solved again with the DG solenoidal formulation. In the DG solenoidal formulation incompressible flows are first solved for velocity and only part of the pressure's degrees of freedom (hybrid pressure), reducing the overall size of the system to be solved, while the rest of pressure degrees of freedom (interior pressure) is computed as a postprocessing. A numerical validation of the method is given with the simulation of the classical benchmark test of the flow past a cylinder, showing its good performance in several cases tested.En aquesta Tesina es proposa una formulació combinada de dos mètodes numèrics: ”Discontinuous Galerkin Method” (DG) amb funcions de base solenoïdals i ”eXtended Finite Element Method”(XFEM), per tal de resoldre les equacions de Navier-Stokes per a fluxos no estacionaris al voltant d’un objecte sòlid, proporcionant alts ordres de precisió en l’espai i el temps. Aquesta formulació combinada DG-XFEM simplifica el procés de mallat, utilitzant malles estructurades que a més no necessiten ser actualitzades en cada pas de temps si l’objecte es mou, reduint per tant el cost computacional. En la formulació DG-XFEM s’empra una malla estructurada fixa i els seus elements es classifiquen en tres grups, els quals reben tractaments diferents. Primerament, els elements dins del sòlid són exclosos en els càlculs ja que es tracten com a buits. A continuació, els elements que pertanyen al fluid es calculen igual que en la formulació de DG solenoïdal. Per últim, en els elements tallats per la interfase es modifica la integració fent servir XFEM per tal de tenir en compte només la regió de fluid, considerant cèl·lules d’integració corbes per calcular de forma acurada les integrals en elements d’alt ordre; tot seguit es resol de nou emprant la formulació de DG solenoïdal. En la formulació de DG solenoïdal els fluxos incompressibles es resolen en primer lloc per a les velocitats i només una part dels graus de llibertat de la pressió (pressió híbrida), reduint la grandària global del sistema d’equacions a resoldre, mentre que la resta de graus de llibertat (pressió interior) es calculen com un post-procés. El mètode està validat amb la simulació del clàssic problema de test d’un flux de fluid al voltant d’un cilindre, mostrant el seu bon comportament en vàries simulacions

Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espectroscopía de fluorescencia

Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjustedR2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil.La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R2 -ajustado = 0,91), longitud de onda que coincide con la banda distintiva de pigmentos.Secretaría de Estado de Investigación, Desarrollo e Innovación de España-AGL2015-69320-

Predicción de la frescura del aceite de oliva virgen extra durante el almacenamiento mediante espectroscopía de fluorescencia

Virgin olive oil quality relates to flavor and unique health benefits. Some of these properties are at the most desirable level when the oil is just extracted, since it is not a product that improves with age. On the contrary, the concentrations of many compounds change during its shelf-life. These changes reveal the aging of the oil but do not necessarily mean decay in sensory properties, so in some cases an aged oil from healthy olives may be better qualified than a fresh one from olives affected by fermentation. The aim of this work is to analyze different methodologies proposed for assessing the quality of virgin olive oil with implications in freshness and aging of the oil, and to highlight the possibilities of rapid spectrofluorimetric techniques for assessing oil freshness by checking the evolution of pigments during storage. The observed change in the selected spectral features and mathematical modelling over time was compared with the accepted model for predicting the amount of pyropheophytin a, which is based on isokinetic studies. The best regression was obtained for 655 nm (adjustedR2 = 0.91) wavelength, which matches the distinctive band of pigments. The two mathematical models described in this study highlight the usefulness of pigments in the prediction of the shelf-life of extra virgin olive oil.La calidad del aceite de oliva virgen está relacionada con su flavor y sus beneficios únicos para la salud. Algunas de estas propiedades se encuentran en el nivel más deseable cuando el aceite está recién extraído, ya que no es un producto que mejore con el tiempo. Por el contrario, las concentraciones de muchos compuestos cambian a lo largo de la vida útil. Estos cambios revelan el envejecimiento del aceite, pero no implican necesariamente la alteración de las propiedades sensoriales, por lo que en algunos casos un aceite envejecido procedente de aceitunas sanas puede presentar mejor calidad que uno fresco procedente de aceitunas afectadas por procesos de fermentación. El objetivo de este trabajo es estudiar diferentes metodologías propuestas para evaluar la calidad del aceite de oliva virgen con implicaciones en la frescura y el envejecimiento del aceite, destacando las posibilidades de las rápidas técnicas espectrofluorométricas para evaluar la frescura del aceite verificando la evolución de los pigmentos durante el almacenamiento. El cambio observado en las características espectrales seleccionadas y su modelado matemático a lo largo del tiempo se comparó con el modelo aceptado para predecir la cantidad de pirofeofitina a, que se basa en estudios isocinéticos. Los dos modelos matemáticos descritos en este estudio pusieron de manifiesto la utilidad de los pigmentos en la predicción de la vida útil del aceite de oliva virgen extra. La mejor regresión se obtuvo para 655 nm (R2 -ajustado = 0,91), longitud de onda que coincide con la banda distintiva de pigmentos.Secretaría de Estado de Investigación, Desarrollo e Innovación de España-AGL2015-69320-

An analysis of country medal shares in individual sports at the Olympics

Research question: Several studies report modelling relating countries’ medal shares at the Olympics to population and per capita income (host status and political system are typically included as controls). This paper uses a similar model but disaggregates to the level of the individual sport to ask questions such as whether some sports have a less steep relationship with income levels than others and whether hosting effects are more pronounced in some sports than others. Research methods: Employing a random effects tobit model, data on medal shares are modelled across 15 sports at six editions of the Games (1992–2012). Marginal effects, calculated for the case of cycling, illustrate how far many poor countries are from reasonable expectation of achieving medals. Results and findings: Income is influential on outcomes in all sports, its effects most pronounced in sports with substantial requirements for specific capital equipment; the distribution of medals is less unequal in sports practised in multi-sports venues. Gains from hosting vary in magnitude, performance tending to be elevated most in sports with outcomes strongly influenced by judges. Implications: For poorer countries, the paper identifies a small group of sports on which it would be most realistic to focus resources. For Games organisers, who must decide which sports to include, it provides information relevant to the goal of spreading success more evenly across countries. For example, proposals to exclude wrestling are shown to have been potentially harmful to medal prospects of poorer countries

Kajian Implementasi

The complexity of the construction work, the risk of workplace accidents become higher, so the Health and Safety Work Management System (SMK3) important to be implemented in the construction company. Therefore, it is necessary to know how far the extent of implementation SMK3 especially in construction services company in Kupang City. This study used the questionnaire. The result of questionnaires data collection is processed using the Normalization de Boer formula and analyzed with concept of Traffic Light System. The survey results revealed that the percentage of SMK3 implementation in construction services company in Kota Kupang is 62.38% (yellow category) and the accident rate is on the green category. This explained that SMK3 implementations are at level 2 (safe enough). Based on the type of company, BUMN enterprises have SMK3 implementation of 87.10% and domestic private firms by 56.06%. SMK3 implementation for 5-10 year-old company at 47.85%, 10-20 years-old company at 54.18%, and the company aged > 20 years at 79.74%. The provisions of SMK3 largely have been done by construction companies. The ten provisions have been done mostly are applied of the K3 set policy, identify the hazards that will occur, to provide funds for the implementation of K3, control determines the risk of accidents, regulations made under the laws of K3, P3K facilities in sufficient quantity, create goals and objectives to be achieved, all parties involved in construction services companies should play a role in maintaining and controlling the implementation of the K3, the division of duties and responsibilities are clear and the implementation of controls to manage risks K3

Urban toponymy as a tool for interpreting the physical environment. A case study: Barcelona's mediaeval old town

Barcelona's mediaeval old town, today known as Ciutat Vella, is predominantly flat in appearance. However, a more detailed inspection reveals it to stand on a physical base of very uneven altitude, with numerous changes of gradient between high- and low-lying areas. In fact, the original core of the city, on which the Roman settlement of Barcino was built, is a small hill (Mons Taber) that rises above the rest of the old town. There are many urban toponyms in Ciutat Vella that indicate that the streets 'descend' from the top of the hill in all directions (from what would have been the Roman core down into the mediaeval quarters), and which usually receive the name baixada (Baixada de la Presó, Baixada de Santa Anna, etc.). Although this is the most significant of the toponyms, it is not the only one. Other names serve as 'indicators of the landscape': Pla de la Boqueria and Pla de Palau refer to flat urban spaces; Jonqueres and les Arenes, to low-lying depressions; and la Rambla, to the ancient hydrographic network. A toponym indicating a rise in altitude or a depression, as irrelevant as it may seem today, may historically have been significant, as it would have indicated whether the land was susceptible to flooding and, therefore, whether or not it was suitable for given activities. This study combines the qualitative approach characteristic of classical toponymic analyses with quantitative methodologies (specifically, LIDAR technology applied to Barcelona's physical environment), which we have employed before in other Mediterranean cities, such as Valencia. Keywords: urban toponymy, Barcelona, mediaeval town, landscape indicators