http://hdl.handle.net/2117/3968 Sun, 19 May 2013 02:01:43 GMT 2013-05-19T02:01:43Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/14928 Title: Modelling shoreline sand waves: application to the coast of Namibia Authors: Falqués Serra, Albert; Van den Berg, Niels; Ribas Prats, Francesca; Caballeria Suriñach, Miquel Abstract: The SW coast of Africa (Namibia and part of Angola) features very long sandy beaches and a wave climate dominated by energetic swells from the SSW, therefore approaching the coast with a very high obliquity. Satellite images reveal that along that coast there are many shoreline sand waves with wavelengths ranging from 2 to 8 km. A more detailed study, including a Fourier analysis of the shoreline position, confirms a high spectral density concentration at these lengths scales. Also, it becomes apparent that at least some of the sand waves are dynamically active rather than being controlled by the geological setting. A morphodynamic model is used to test the hypothesis that these sand waves could emerge as free morphodynamic instabilities of the coastline due to the obliquity in wave incidence. It is found that the wave period, Tp, is crucial to establish the tendency to stability or instability, instability increasing for decreasing period, whilst there is some discrepancy in the observed periods. Model results for Tp = 7 s clearly show the tendency for the coast to develop free sand waves at 2 km wavelength within a few years, which migrate to the north at rates of 0.6-0.7 km/yr. For Tp = 8 s, instability is weaker and rather sensitive to other factors as the underlying bathymetry. In this case, the coast seems to be nearly at neutral stability so that sand waves originated from other mechanisms can propagate downdrift with little decay. http://hdl.handle.net/2117/14928 Falqués Serra, Albert; Van den Berg, Niels; Ribas Prats, Francesca; Caballeria Suriñach, Miquel no The SW coast of Africa (Namibia and part of Angola) features very long sandy beaches and a wave climate dominated by energetic swells from the SSW, therefore approaching the coast with a very high obliquity. Satellite images reveal that along that coast there are many shoreline sand waves with wavelengths ranging from 2 to 8 km. A more detailed study, including a Fourier analysis of the shoreline position, confirms a high spectral density concentration at these lengths scales. Also, it becomes apparent that at least some of the sand waves are dynamically active rather than being controlled by the geological setting. A morphodynamic model is used to test the hypothesis that these sand waves could emerge as free morphodynamic instabilities of the coastline due to the obliquity in wave incidence. It is found that the wave period, Tp, is crucial to establish the tendency to stability or instability, instability increasing for decreasing period, whilst there is some discrepancy in the observed periods. Model results for Tp = 7 s clearly show the tendency for the coast to develop free sand waves at 2 km wavelength within a few years, which migrate to the north at rates of 0.6-0.7 km/yr. For Tp = 8 s, instability is weaker and rather sensitive to other factors as the underlying bathymetry. In this case, the coast seems to be nearly at neutral stability so that sand waves originated from other mechanisms can propagate downdrift with little decay. http://hdl.handle.net/2117/16259 Title: Rehabilitación energética de edificios escolares en clima mediterráneo: caso de estudio, Barcelona Authors: Bosch González, Montserrat; Rodríguez Cantalapiedra, Inma; Álvarez del Castillo, Javier Abstract: necesidad de reducir el consumo energético se hace cada día más evidente, especialmente en Europa debido a su situación de dependencia energética de países externos a la Unión y también por razones relacionadas con el impacto ambiental y las emisiones asociadas. En este contexto, la rehabilitación energética de edificios es una línea de trabajo prioritaria que actúa sobre el parque edificado, y los edificios públicos deben ser un modelo o ejemplo para impulsar este tipo de actuaciones. Los centros docentes, con un potencial de ahorro muy importante y con unos consumos energéticos asociados básicamente a dos grandes conceptos, la iluminación y la climatización, pueden considerarse como un laboratorio de investigación en cuanto a eficiencia energética. A partir de las experiencias adquiridas durante más de 10 años se ha desarrollado una metodología de análisis para la intervención en edificios docentes en Barcelona con los siguientes objetivos: definir los indicadores estratégicos para identificar las oportunidades de ahorro, evaluar las posibles medidas de reducción de consumos a partir de la limitación de la demanda, analizar y dar contenido al papel de cada uno de los actores que intervienen en las estrategias de uso y gestión de los edificios escolares y establecer los criterios que deben considerarse para realizar las futuras intervenciones de rehabilitación energética. El método, como manera de pensar ordenadamente, ha de permitir optimizar los recursos y descubrir les rutas de trabajo que nos conduzcan al objetivo final: reducir el consumo energético del parque edificado http://hdl.handle.net/2117/16259 Bosch González, Montserrat; Rodríguez Cantalapiedra, Inma; Álvarez del Castillo, Javier no necesidad de reducir el consumo energético se hace cada día más evidente, especialmente en Europa debido a su situación de dependencia energética de países externos a la Unión y también por razones relacionadas con el impacto ambiental y las emisiones asociadas. En este contexto, la rehabilitación energética de edificios es una línea de trabajo prioritaria que actúa sobre el parque edificado, y los edificios públicos deben ser un modelo o ejemplo para impulsar este tipo de actuaciones. Los centros docentes, con un potencial de ahorro muy importante y con unos consumos energéticos asociados básicamente a dos grandes conceptos, la iluminación y la climatización, pueden considerarse como un laboratorio de investigación en cuanto a eficiencia energética. A partir de las experiencias adquiridas durante más de 10 años se ha desarrollado una metodología de análisis para la intervención en edificios docentes en Barcelona con los siguientes objetivos: definir los indicadores estratégicos para identificar las oportunidades de ahorro, evaluar las posibles medidas de reducción de consumos a partir de la limitación de la demanda, analizar y dar contenido al papel de cada uno de los actores que intervienen en las estrategias de uso y gestión de los edificios escolares y establecer los criterios que deben considerarse para realizar las futuras intervenciones de rehabilitación energética. El método, como manera de pensar ordenadamente, ha de permitir optimizar los recursos y descubrir les rutas de trabajo que nos conduzcan al objetivo final: reducir el consumo energético del parque edificado http://hdl.handle.net/2117/19318 Title: Percolation experiments in complex fractal media Authors: Redondo Apraiz, José Manuel; Tarquis, Ana Maria; Cherubini, Claudia; Lopez Gonzalez-Nieto, Pilar; Vila, Teresa Thu, 16 May 2013 16:20:33 GMT http://hdl.handle.net/2117/19318 2013-05-16T16:20:33Z Redondo Apraiz, José Manuel; Tarquis, Ana Maria; Cherubini, Claudia; Lopez Gonzalez-Nieto, Pilar; Vila, Teresa no Percolation, Fractal, Karstic http://hdl.handle.net/2117/19317 Title: SAR measurements of coastal features in the NW Mediterranean Authors: Redondo Apraiz, José Manuel; Martínez Benjamín, Juan José; Díez Rilova, Margarita; Lopez Gonzalez-Nieto, Pilar Thu, 16 May 2013 16:15:04 GMT http://hdl.handle.net/2117/19317 2013-05-16T16:15:04Z Redondo Apraiz, José Manuel; Martínez Benjamín, Juan José; Díez Rilova, Margarita; Lopez Gonzalez-Nieto, Pilar no SAR, Coastal Features, Vortex http://hdl.handle.net/2117/19289 Title: White dwarf mergers and the origin of R coronae borealis stars Authors: Lorén Aguilar, Pablo; Longland, Richard Leigh; José Pont, Jordi; García-Berro Montilla, Enrique; Althaus, Leandro G.; Isern-Fontanet, J. Abstract: We present a nucleosynthesis study of the merger of a 0.4 M⊙ helium white dwarf with a 0.8 M⊙ carbon-oxygen white dwarf, coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars. Thu, 16 May 2013 11:56:45 GMT http://hdl.handle.net/2117/19289 2013-05-16T11:56:45Z Lorén Aguilar, Pablo; Longland, Richard Leigh; José Pont, Jordi; García-Berro Montilla, Enrique; Althaus, Leandro G.; Isern-Fontanet, J. no We present a nucleosynthesis study of the merger of a 0.4 M⊙ helium white dwarf with a 0.8 M⊙ carbon-oxygen white dwarf, coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars. http://hdl.handle.net/2117/18967 Title: The evolution and C, N and O yields of intermediate-mass Z = 10-5 stars in isolation and in close binary systems Authors: Gil Pons, Pilar; Doherty, Carolyn L.; Suda, T.; Campbell, Simon; Lau, H.; Mansouri Guilani, Shervin; Lattanzio, John Abstract: We have computed the evolution of Z = 10−5 stars of masses between 4 and 9 M , from their main sequence till the late TP-(S)AGB phase.We use a recent version of the Mount Stromlo Stellar Evolution code, in which molecular opacities include the effects of variable C/O abundances ratio, [1]. By computing hundreds (or thousands) of thermal pulses, we have been able either to remove the bulk of the stellar envelopes or to obtain stellar cores very close to MCh. Using [2] prescription for the mass loss rates the computed stars lose their envelopes before their cores reach MCh. This would forbid the occurrence of SN 1.5 for Z = 10−5 stars. Nevertheless the results by [3] suggest that the former prescription might overestimate the mass-loss rates. Therefore we have decreased the rates by [2]. For all the cases we present, even a decrease of one order of magnitude let the stellar cores reach MCh before the envelope is lost. Therefore the occurrence of SN1.5 at Z = 10 −5 and their potential contribution to the chemical evolution of the Universe should not be discarded. We consider the combined effects of the deep/corrosive 2 nd dredge-up and Roche Lobe Overflow (RLOF) during the E-AGB to help to constrain the contribution of massive Z = 10 −5 AGB stars to the CEMPs problem. Our results have implications for the chemical evolution of the Universe and might provide another piece for the puzzle of the CEMPs problem. Tue, 23 Apr 2013 14:39:01 GMT http://hdl.handle.net/2117/18967 2013-04-23T14:39:01Z Gil Pons, Pilar; Doherty, Carolyn L.; Suda, T.; Campbell, Simon; Lau, H.; Mansouri Guilani, Shervin; Lattanzio, John no We have computed the evolution of Z = 10−5 stars of masses between 4 and 9 M , from their main sequence till the late TP-(S)AGB phase.We use a recent version of the Mount Stromlo Stellar Evolution code, in which molecular opacities include the effects of variable C/O abundances ratio, [1]. By computing hundreds (or thousands) of thermal pulses, we have been able either to remove the bulk of the stellar envelopes or to obtain stellar cores very close to MCh. Using [2] prescription for the mass loss rates the computed stars lose their envelopes before their cores reach MCh. This would forbid the occurrence of SN 1.5 for Z = 10−5 stars. Nevertheless the results by [3] suggest that the former prescription might overestimate the mass-loss rates. Therefore we have decreased the rates by [2]. For all the cases we present, even a decrease of one order of magnitude let the stellar cores reach MCh before the envelope is lost. Therefore the occurrence of SN1.5 at Z = 10 −5 and their potential contribution to the chemical evolution of the Universe should not be discarded. We consider the combined effects of the deep/corrosive 2 nd dredge-up and Roche Lobe Overflow (RLOF) during the E-AGB to help to constrain the contribution of massive Z = 10 −5 AGB stars to the CEMPs problem. Our results have implications for the chemical evolution of the Universe and might provide another piece for the puzzle of the CEMPs problem. http://hdl.handle.net/2117/18917 Title: Frontogenesis in the meso-a and meso-ß scales in the Mediterranean basin: From cloud arch to cloud cells. Authors: Mazón Bueso, Jordi; Pino González, David Mon, 22 Apr 2013 12:01:45 GMT http://hdl.handle.net/2117/18917 2013-04-22T12:01:45Z Mazón Bueso, Jordi; Pino González, David no http://hdl.handle.net/2117/18916 Title: Nocturnal offshore precipitation near the coastline in the Mediterranean basin Authors: Mazón Bueso, Jordi; Pino González, David Mon, 22 Apr 2013 11:48:29 GMT http://hdl.handle.net/2117/18916 2013-04-22T11:48:29Z Mazón Bueso, Jordi; Pino González, David no http://hdl.handle.net/2117/18790 Title: The role of large sea-land temperature, the coastline shape and the SST in Authors: Mazón Bueso, Jordi; Pino González, David Mon, 15 Apr 2013 11:35:30 GMT http://hdl.handle.net/2117/18790 2013-04-15T11:35:30Z Mazón Bueso, Jordi; Pino González, David no http://hdl.handle.net/2117/18789 Title: Study of a system to generate electricity on the Moon's surface during the lunar night Authors: Torroba, Oscar; Climent, Blai; González Cinca, Ricardo; Ramachandran, Narayanan; Griffin, Michael D. Abstract: One of the biggest challenges of the exploration of the Moon is the survival of the crew and the lunar assets during the lunar night. The environmental conditions on the lunar surface and its cycle, with long periods of darkness, make any long mission in need of specific amounts of heat and electricity to be successful. We have analyzed two different systems to produce heat and electricity on the Moon’s surface. The first system consists of the Thermal Wadis, sources of thermal power that can be used to supply heat to protect the exploration systems from the extreme cold during periods of darkness. Previous results showed that Wadis can supply enough heat to keep lunar devices such as rovers above their minimum operating temperature (approximately 243 K). The second system studied here is the Thermal Energy Storage (TES), which is able to run a heat engine during the lunar night to produce electricity. When the Sun is shining on the Moon’s surface, the system can run the engine directly using the solar power and simultaneously heat a thermal mass. This thermal mass is used as a high temperature source to run the heat engine during the night. We present analytical and numerical calculations for the determination of an appropriate thermal mass for the TES system. Mon, 15 Apr 2013 11:04:41 GMT http://hdl.handle.net/2117/18789 2013-04-15T11:04:41Z Torroba, Oscar; Climent, Blai; González Cinca, Ricardo; Ramachandran, Narayanan; Griffin, Michael D. no One of the biggest challenges of the exploration of the Moon is the survival of the crew and the lunar assets during the lunar night. The environmental conditions on the lunar surface and its cycle, with long periods of darkness, make any long mission in need of specific amounts of heat and electricity to be successful. We have analyzed two different systems to produce heat and electricity on the Moon’s surface. The first system consists of the Thermal Wadis, sources of thermal power that can be used to supply heat to protect the exploration systems from the extreme cold during periods of darkness. Previous results showed that Wadis can supply enough heat to keep lunar devices such as rovers above their minimum operating temperature (approximately 243 K). The second system studied here is the Thermal Energy Storage (TES), which is able to run a heat engine during the lunar night to produce electricity. When the Sun is shining on the Moon’s surface, the system can run the engine directly using the solar power and simultaneously heat a thermal mass. This thermal mass is used as a high temperature source to run the heat engine during the night. We present analytical and numerical calculations for the determination of an appropriate thermal mass for the TES system. http://hdl.handle.net/2117/18593 Title: Variación anual e internacional del manto nivoso en el Port del Compte-Serra del Cadí a partir de imágenes MODIS. Authors: Herms, I.; Jorge Sánchez, Juan Abstract: El estudio de la dinámica espacial y temporal de la cubierta de nieve permi e comprender el funcionamiento del sistema hidrológico y plantear tendencias climáticasque afectan al balance hídrico. Mediante imágenes de satélite de diferente resolución ya se han llevado a cabo estimaciones de dicha cubierta en el pirineo catalán por diversos autores comprobándose su aplicabilidad..En este trabajo se muestran los resultados de la aplicación de una metodología basada en los productos MOD10A2, derivados del procesamiento de las imágenes del sensor MODIS (accesibles en la web del NSIDC de la NASA), para la obtención de la cubierta nivosa en un sector del Pirineo oriental catalán, a diferentes cotas de altitud y a lo largo del período 2002-2007. Los resultados, aunque se disponga de pocos años de análisis, muestran una tendencia climática hacia la disminución progresiva en la extensión de la cubierta de nieve, especialmente a partir de la cota 2000 msnm; se mantiene la duración de suelo cubierto por nieve entre los meses de octubre y mayo, con un 50% de la superficie cubierta por encima de la cota 1000 y produciéndose en todas las temporadas,el inicio de las grandes nevadas entre la segunda y la tercera semana de noviembre. Cabe resaltar que se ha procurado trabajar siempre con software libre (sobretodo con gvSIG). Thu, 04 Apr 2013 07:22:25 GMT http://hdl.handle.net/2117/18593 2013-04-04T07:22:25Z Herms, I.; Jorge Sánchez, Juan no El estudio de la dinámica espacial y temporal de la cubierta de nieve permi e comprender el funcionamiento del sistema hidrológico y plantear tendencias climáticasque afectan al balance hídrico. Mediante imágenes de satélite de diferente resolución ya se han llevado a cabo estimaciones de dicha cubierta en el pirineo catalán por diversos autores comprobándose su aplicabilidad..En este trabajo se muestran los resultados de la aplicación de una metodología basada en los productos MOD10A2, derivados del procesamiento de las imágenes del sensor MODIS (accesibles en la web del NSIDC de la NASA), para la obtención de la cubierta nivosa en un sector del Pirineo oriental catalán, a diferentes cotas de altitud y a lo largo del período 2002-2007. Los resultados, aunque se disponga de pocos años de análisis, muestran una tendencia climática hacia la disminución progresiva en la extensión de la cubierta de nieve, especialmente a partir de la cota 2000 msnm; se mantiene la duración de suelo cubierto por nieve entre los meses de octubre y mayo, con un 50% de la superficie cubierta por encima de la cota 1000 y produciéndose en todas las temporadas,el inicio de las grandes nevadas entre la segunda y la tercera semana de noviembre. Cabe resaltar que se ha procurado trabajar siempre con software libre (sobretodo con gvSIG). http://hdl.handle.net/2117/18554 Title: Flash heat events: the case of 27th August 2010 in northeast of Iberian Authors: Mazón Bueso, Jordi; Pino González, David Wed, 03 Apr 2013 09:34:09 GMT http://hdl.handle.net/2117/18554 2013-04-03T09:34:09Z Mazón Bueso, Jordi; Pino González, David no http://hdl.handle.net/2117/18552 Title: Uncertainties in the CO2 budget associated to the diurnal variability of the boundary layer dynamics Authors: Pino González, David; Kaikkonen, Jukka-Pekka; Vilà-Guerau de Arellano, Jordi Wed, 03 Apr 2013 09:05:04 GMT http://hdl.handle.net/2117/18552 2013-04-03T09:05:04Z Pino González, David; Kaikkonen, Jukka-Pekka; Vilà-Guerau de Arellano, Jordi no http://hdl.handle.net/2117/18494 Title: Simplified Femto-satellite Operations for Disaster Management Missions Authors: Tristancho Martínez, Joshua; Gutierrez Cabello, Jorge Luis Abstract: The reduction in size of satellites is reaching at the range of femto-satellites, i.e. satellites less than 100 grams in mass. One of the key points to achieve such a reduc tion is to simplify the design of the satellite, bu t also to simplify their mission operation. In the present work, a sim plified method for responsive femto-satellite opera tions is presented which is able to deal with the main types of disaster management tasks. Then, a mission is e asy to program using a few default functionalities in everyone of a cooperative satellite swarm giving a list of coor dinates. The protocol is able to update the list for adaptive mi ssions which are based on coordinates. This feature would allow an easy control for the first responders when they are in the field in the beginning of an emergency. The se satellites could send real-time pictures to the first responde rs agents, without the need of a complex ground sta tion infrastructure, until the help arrives Fri, 22 Mar 2013 12:53:17 GMT http://hdl.handle.net/2117/18494 2013-03-22T12:53:17Z Tristancho Martínez, Joshua; Gutierrez Cabello, Jorge Luis no The reduction in size of satellites is reaching at the range of femto-satellites, i.e. satellites less than 100 grams in mass. One of the key points to achieve such a reduc tion is to simplify the design of the satellite, bu t also to simplify their mission operation. In the present work, a sim plified method for responsive femto-satellite opera tions is presented which is able to deal with the main types of disaster management tasks. Then, a mission is e asy to program using a few default functionalities in everyone of a cooperative satellite swarm giving a list of coor dinates. The protocol is able to update the list for adaptive mi ssions which are based on coordinates. This feature would allow an easy control for the first responders when they are in the field in the beginning of an emergency. The se satellites could send real-time pictures to the first responde rs agents, without the need of a complex ground sta tion infrastructure, until the help arrives http://hdl.handle.net/2117/18480 Title: Plasmaspheric Electron Content contribution inferred from ground and radio occultation derived Total Electron Content Authors: Aragón Ángel, María Ángeles; Sanz Subirana, Jaume; Juan Zornoza, José Miguel; Hernández Pajares, Manuel; Altadill, D. Abstract: The FORMOSAT-3/COSMIC satellite constellation has become an important source of remote sensing data globally distributed for the sounding of the atmosphere of the Earth and, in particular, the ionosphere. In this study, electron density profiles derived using the Improved Abel transform inversion in Radio Occultation (RO) scenarios are used as input data to derive some features regarding the topside and outside ionospheric contribution, hence, the plasmasphere in great extend, by means of the analysis of the integral values of the shape functions corresponding to each density profile. The novelty presented in this paper, with respect to previous works, is the use of experimental data from the FORMOSAT-3/COSMIC RO-derived electron densities to infer global characterizations and distribution of the Total Electron Content (TEC) into its main components: ionospheric TEC and plasmaspheric TEC, both contributing to TEC. The results show agreement with earlier modeled and observational data from previous local studies of the plasmaspheric contribution. The main conclusion of this research is that the plasmasphere contributes significantly to TEC and the ratio between plasmaspheric TEC and TEC has been climatologically analyzed for the whole year 2007 confirming that the major relative impact of the plasmasphere is during night time. The added value of this study is that the results obtained are globally distributed and can help to infer a proxy for the plasmaspheric contribution at any location over the globe thanks to the FORMOSAT-3/COSMIC coverage. Fri, 22 Mar 2013 10:59:58 GMT http://hdl.handle.net/2117/18480 2013-03-22T10:59:58Z Aragón Ángel, María Ángeles; Sanz Subirana, Jaume; Juan Zornoza, José Miguel; Hernández Pajares, Manuel; Altadill, D. no Abel transform, electron density, FORMOSAT-3/COSMIC, GPS, Ionosphere, Plasmasphere, radio occultation, Separability, TEC The FORMOSAT-3/COSMIC satellite constellation has become an important source of remote sensing data globally distributed for the sounding of the atmosphere of the Earth and, in particular, the ionosphere. In this study, electron density profiles derived using the Improved Abel transform inversion in Radio Occultation (RO) scenarios are used as input data to derive some features regarding the topside and outside ionospheric contribution, hence, the plasmasphere in great extend, by means of the analysis of the integral values of the shape functions corresponding to each density profile. The novelty presented in this paper, with respect to previous works, is the use of experimental data from the FORMOSAT-3/COSMIC RO-derived electron densities to infer global characterizations and distribution of the Total Electron Content (TEC) into its main components: ionospheric TEC and plasmaspheric TEC, both contributing to TEC. The results show agreement with earlier modeled and observational data from previous local studies of the plasmaspheric contribution. The main conclusion of this research is that the plasmasphere contributes significantly to TEC and the ratio between plasmaspheric TEC and TEC has been climatologically analyzed for the whole year 2007 confirming that the major relative impact of the plasmasphere is during night time. The added value of this study is that the results obtained are globally distributed and can help to infer a proxy for the plasmaspheric contribution at any location over the globe thanks to the FORMOSAT-3/COSMIC coverage.