http://hdl.handle.net/2117/215 Tue, 21 May 2013 11:15:48 GMT 2013-05-21T11:15:48Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/19322 Title: Testing a new submersible drill rig Authors: Romero, F.; Devincenzi, M.J.; Pérez Garcia, N.; Arroyo Alvarez de Toledo, Marcos; Deu, Amadeu Abstract: The paper describes the main features and initial underwater field-testing results of a remotely operated submersible drill rig designed to obtain continuous cores of soil and/or rock up to 6m long in water depths of 200m. The rig mast angle is hydraulically actuated covering 90° of altitude. This enables both a fully horizontal position used for deployment onto, and recovery of the rig from, the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters such as torque, thrust, advance, injection rate and pressure are recorded. The equipment is deployable from a variety of platforms. Thu, 16 May 2013 17:46:05 GMT http://hdl.handle.net/2117/19322 2013-05-16T17:46:05Z Romero, F.; Devincenzi, M.J.; Pérez Garcia, N.; Arroyo Alvarez de Toledo, Marcos; Deu, Amadeu no The paper describes the main features and initial underwater field-testing results of a remotely operated submersible drill rig designed to obtain continuous cores of soil and/or rock up to 6m long in water depths of 200m. The rig mast angle is hydraulically actuated covering 90° of altitude. This enables both a fully horizontal position used for deployment onto, and recovery of the rig from, the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters such as torque, thrust, advance, injection rate and pressure are recorded. The equipment is deployable from a variety of platforms. http://hdl.handle.net/2117/19320 Title: A submersible drill rig for coring soils and rocks Authors: Devincenzi, M.J.; Pérez Garcia, N.; Samoili, K.; Arroyo Alvarez de Toledo, Marcos Abstract: The paper describes the design and initial field-testing of a remotely operated submersible drill rig able to obtain continuous cores of soil and/or rock up to 6 m long. The rig mast angle is hydraulically actuated covering 90 degrees of altitude. This enables both a fully horizontal position used for deployment onto and recovery of the rig from the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133 mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters like torque, thrust, advance, injection rate and pressure are recorded. The equipment is adapted for geotechnical investigation of the renewable energy industry, as well as pipelines, cables and dredging requiring platform or near shore site investigation. The equipment is deployable from a variety of platforms and does not require a fully-fledged drill ship. Thu, 16 May 2013 16:33:30 GMT http://hdl.handle.net/2117/19320 2013-05-16T16:33:30Z Devincenzi, M.J.; Pérez Garcia, N.; Samoili, K.; Arroyo Alvarez de Toledo, Marcos no Drill rigs, Geotechnical investigations, Inclination sensors, Injection rates, Nearshores, Operation parameters, Remotely operated submersibles, Renewable Energy industries, Site investigations, Vertical positions The paper describes the design and initial field-testing of a remotely operated submersible drill rig able to obtain continuous cores of soil and/or rock up to 6 m long. The rig mast angle is hydraulically actuated covering 90 degrees of altitude. This enables both a fully horizontal position used for deployment onto and recovery of the rig from the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133 mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters like torque, thrust, advance, injection rate and pressure are recorded. The equipment is adapted for geotechnical investigation of the renewable energy industry, as well as pipelines, cables and dredging requiring platform or near shore site investigation. The equipment is deployable from a variety of platforms and does not require a fully-fledged drill ship. http://hdl.handle.net/2117/19319 Title: Design control and monitoring of a jet grouted excavation bottom plug Authors: Eramo, N.; Modoni, Giuseppe; Arroyo Alvarez de Toledo, Marcos Abstract: Jet grouting is adopted in different geotechnical conditions to ensure provisional earth retaining and waterproofing functions at the bottom and walls of excavations. Despite careful theoretical models avail-able to predict the mechanical response of these structures, design is often carried out without adequate con-trol, i.e. by assuming ideal effectiveness of ground improvement. On the contrary, adverse effects have been documented by past experiences which can be traced back to erroneous prediction of treatments effects, inac-curate control of the execution or to unexpected responses of the surrounding environment. All these uncertainties, which become particularly critical when excavation is performed in urbanized areas, can be mini-mized by detailed preliminary field trials, accurate controls of the execution of treatments and a prompt monitoring of the surrounding area. The present paper describes this methodology applied to the design and the execution of a massive jet grouting bottom plug forming the base of a large excavation in city environment. The results of preliminary field trials are summarized to directly compare the effectiveness of different injection systems and introduced in statistical design analyses of the jet grouted structure. A detailed investigation of the movements induced at ground level by injections is also reported. To this aim, the evolution of displacements recorded around trial columns and on the area surrounding the excavation is mapped to evaluate the effects of the different adopted injection techniques. Thu, 16 May 2013 16:26:07 GMT http://hdl.handle.net/2117/19319 2013-05-16T16:26:07Z Eramo, N.; Modoni, Giuseppe; Arroyo Alvarez de Toledo, Marcos no Adverse effect, Design control, Earth retaining, Execution control, Field trial, Geotechnical conditions, Ground improvement, Injection systems, Injection techniques, Jet grouting, Mechanical response, Statistical design, Surface movement, Surrounding environment, Theoretical models, Urban areas Jet grouting is adopted in different geotechnical conditions to ensure provisional earth retaining and waterproofing functions at the bottom and walls of excavations. Despite careful theoretical models avail-able to predict the mechanical response of these structures, design is often carried out without adequate con-trol, i.e. by assuming ideal effectiveness of ground improvement. On the contrary, adverse effects have been documented by past experiences which can be traced back to erroneous prediction of treatments effects, inac-curate control of the execution or to unexpected responses of the surrounding environment. All these uncertainties, which become particularly critical when excavation is performed in urbanized areas, can be mini-mized by detailed preliminary field trials, accurate controls of the execution of treatments and a prompt monitoring of the surrounding area. The present paper describes this methodology applied to the design and the execution of a massive jet grouting bottom plug forming the base of a large excavation in city environment. The results of preliminary field trials are summarized to directly compare the effectiveness of different injection systems and introduced in statistical design analyses of the jet grouted structure. A detailed investigation of the movements induced at ground level by injections is also reported. To this aim, the evolution of displacements recorded around trial columns and on the area surrounding the excavation is mapped to evaluate the effects of the different adopted injection techniques. 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/2117/19308 Title: Testing block samples from silty deposits Authors: Pineda Jiménez, Jubert Andrés; Arroyo Alvarez de Toledo, Marcos; Sau Valenzuela, Núria; Gens Solé, Antonio; Pérez, Norma Abstract: The paper describes the results of a comprehensive experimental program aimed to characterize block samples of silty deposits obtained from the deltaic zone of the Llobregat River ( Barcelona).Undisturbed block samples were obtained from a deep excavation taking place on interbedded sandy silts by hand retrieval. A detailed examination of the retrieved blocks, including suction measurements as well as Computed Axial Tomography (CAT) scans was performed before testing. Material characterization was complemented with identification tests carried out on representative samples obtained at different points inside the block. Finally, soil disturbance was evaluated by means of CRS oedometer tests on specimens retrieved at different depths. The spatial variability of suction (water potential) and water content was defined here based on tensiometer measurements. From CAT images the sedimentary nature of the block as well as the position and 3D distribution of heterogeneities could be detected. CRS tests showed a similar stress-strain response from which the evaluation of sample disturbance indicated the very high quality of samples tested. Thu, 16 May 2013 13:41:23 GMT http://hdl.handle.net/2117/19308 2013-05-16T13:41:23Z Pineda Jiménez, Jubert Andrés; Arroyo Alvarez de Toledo, Marcos; Sau Valenzuela, Núria; Gens Solé, Antonio; Pérez, Norma no The paper describes the results of a comprehensive experimental program aimed to characterize block samples of silty deposits obtained from the deltaic zone of the Llobregat River ( Barcelona).Undisturbed block samples were obtained from a deep excavation taking place on interbedded sandy silts by hand retrieval. A detailed examination of the retrieved blocks, including suction measurements as well as Computed Axial Tomography (CAT) scans was performed before testing. Material characterization was complemented with identification tests carried out on representative samples obtained at different points inside the block. Finally, soil disturbance was evaluated by means of CRS oedometer tests on specimens retrieved at different depths. The spatial variability of suction (water potential) and water content was defined here based on tensiometer measurements. From CAT images the sedimentary nature of the block as well as the position and 3D distribution of heterogeneities could be detected. CRS tests showed a similar stress-strain response from which the evaluation of sample disturbance indicated the very high quality of samples tested. http://hdl.handle.net/2117/19305 Title: Site characterization alternatives for numerical models of a deep excavation Authors: Sau, Núria; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio Abstract: A cut-and-cover railway tunnel site on the outskirts of Barcelona benefited from an extensive site investigation campaign. During the construction of the tunnel, the displacement of the wall as well as the of soil beneath was recorded. A 2D numerical model of the excavation sequence was established. The large amount of site investigation data allowed a systematic comparative approach. Four different soil characterization strategies were mimicked, deliberately ignoring one or another subset of the characterization data. While results from CPTu and SPT were assumed equally available to all the hypothetical designers, the extra information for one of them was only laboratory test results, for another one it was pre-bored PMT data, for the third one it was SBPM and cross-hole tests data and, finally, the last one had DMT, SDMT and cross-hole tests data as complementary information. The simulation results are obtained using the Hardening soil model. Thu, 16 May 2013 13:29:24 GMT http://hdl.handle.net/2117/19305 2013-05-16T13:29:24Z Sau, Núria; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio no Barcelona, Comparative approach, Crosshole tests, Deep excavation, Excavation sequences, Hardening soil models, Laboratory test, Railway tunnels, Site characterization, Site investigations, Soil characterization A cut-and-cover railway tunnel site on the outskirts of Barcelona benefited from an extensive site investigation campaign. During the construction of the tunnel, the displacement of the wall as well as the of soil beneath was recorded. A 2D numerical model of the excavation sequence was established. The large amount of site investigation data allowed a systematic comparative approach. Four different soil characterization strategies were mimicked, deliberately ignoring one or another subset of the characterization data. While results from CPTu and SPT were assumed equally available to all the hypothetical designers, the extra information for one of them was only laboratory test results, for another one it was pre-bored PMT data, for the third one it was SBPM and cross-hole tests data and, finally, the last one had DMT, SDMT and cross-hole tests data as complementary information. The simulation results are obtained using the Hardening soil model. http://hdl.handle.net/2117/19303 Title: 3D DEM simulations of CPT in sand Authors: Butlanska, Joanna; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio Abstract: The paper contains an overview of the results obtained in a research project exploring the ability of 3D DEM models to reproduce cone penetration in sands. The sand whose behaviour is mimicked by the discrete material is Ticino sand, a well known reference material for cone penetration tests. A large series of numerical experiments in a cylindrical virtual calibration chambers was performed in materials of medium and high density. Point resistance is shown to fit well with results from previous physical tests when the various scaling factors affecting the problem are taken into account. The effect of different boundary conditions on the test results is illustrated. The appearance of friction fatigue in the shaft resistance is also revealed by the analysis of the numerical results. The micromechanics of cone penetration is also illustrated, showing that a stationary condition is clearly attained for point/soil contacts and how particle flow is affected by boundary conditions. From the results presented it can be inferred that 3D DEM simulations offer a feasible alternative to extend and/or partially substitute the more expensive physical calibration tests in the development of CPT based correlations, as well as powerful capabilities to explore the micromechanics of the problem. Thu, 16 May 2013 13:18:33 GMT http://hdl.handle.net/2117/19303 2013-05-16T13:18:33Z Butlanska, Joanna; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio no Calibration tests, Cone penetration, Cone penetration tests, DEM Simulation, Different boundary condition, Discrete material, Feasible alternatives, Friction fatigue, High density, Numerical experiments, Numerical results, Particle flow, Point resistance, Reference material, Scaling factors, Shaft resistance, Stationary conditions, Virtual calibration The paper contains an overview of the results obtained in a research project exploring the ability of 3D DEM models to reproduce cone penetration in sands. The sand whose behaviour is mimicked by the discrete material is Ticino sand, a well known reference material for cone penetration tests. A large series of numerical experiments in a cylindrical virtual calibration chambers was performed in materials of medium and high density. Point resistance is shown to fit well with results from previous physical tests when the various scaling factors affecting the problem are taken into account. The effect of different boundary conditions on the test results is illustrated. The appearance of friction fatigue in the shaft resistance is also revealed by the analysis of the numerical results. The micromechanics of cone penetration is also illustrated, showing that a stationary condition is clearly attained for point/soil contacts and how particle flow is affected by boundary conditions. From the results presented it can be inferred that 3D DEM simulations offer a feasible alternative to extend and/or partially substitute the more expensive physical calibration tests in the development of CPT based correlations, as well as powerful capabilities to explore the micromechanics of the problem. http://hdl.handle.net/2117/19291 Title: Desarrollo de herramientas para la evaluación preliminar de la peligrosidad de corrientes detríticas Authors: Bregoli, Francesco; Bateman Pinzón, Allen; Medina Iglesias, Vicente César de; Hurlimann Ziegler, Marcel Abstract: Con el objetivo de proporcionar recomendaciones para la alerta temprana de fenómenos potencialmente desencadenantes de corrientes detríticas (“Debris Flow”), uno de los temas principales es la identificación preliminar de zonas de riesgo. Esta identificación es sustancialmente diferente de los mapas de riesgo que se suelen realizar por las autoridades de cuenca con el fin de dar una guía para planes de gestión del territorio. En el caso de alerta temprana, una identificación más aproximativa de las zonas de riesgo es suficiente. En esta perspectiva, los dos componentes del riesgo, peligrosidad y vulnerabilidad, se pueden estimar de una manera simplificada. En este trabajo se han desarrollado unas herramientas para la evaluación rápida de peligro por corrientes detríticas. Se han adaptado metodologías existentes y modelos simplificados y se ha llevado a cabo un útil paquete común de metodologías para una rápida evaluación de la peligrosidad. Se modelan tanto la iniciación como la propagación de corrientes detríticas. Uno de los requisitos del proyecto es definir una herramienta utilizable en diferentes contextos donde el nivel de detalle en los datos de entrada puede ser muy variado. Para lograr este objetivo se define un enfoque multinivel. La metodología se aplica en tres cuencas con características diferentes. Thu, 16 May 2013 12:17:48 GMT http://hdl.handle.net/2117/19291 2013-05-16T12:17:48Z Bregoli, Francesco; Bateman Pinzón, Allen; Medina Iglesias, Vicente César de; Hurlimann Ziegler, Marcel no Con el objetivo de proporcionar recomendaciones para la alerta temprana de fenómenos potencialmente desencadenantes de corrientes detríticas (“Debris Flow”), uno de los temas principales es la identificación preliminar de zonas de riesgo. Esta identificación es sustancialmente diferente de los mapas de riesgo que se suelen realizar por las autoridades de cuenca con el fin de dar una guía para planes de gestión del territorio. En el caso de alerta temprana, una identificación más aproximativa de las zonas de riesgo es suficiente. En esta perspectiva, los dos componentes del riesgo, peligrosidad y vulnerabilidad, se pueden estimar de una manera simplificada. En este trabajo se han desarrollado unas herramientas para la evaluación rápida de peligro por corrientes detríticas. Se han adaptado metodologías existentes y modelos simplificados y se ha llevado a cabo un útil paquete común de metodologías para una rápida evaluación de la peligrosidad. Se modelan tanto la iniciación como la propagación de corrientes detríticas. Uno de los requisitos del proyecto es definir una herramienta utilizable en diferentes contextos donde el nivel de detalle en los datos de entrada puede ser muy variado. Para lograr este objetivo se define un enfoque multinivel. La metodología se aplica en tres cuencas con características diferentes. http://hdl.handle.net/2117/19274 Title: Modelling viscoelastic behaviour of carbón nanotube-reinforced thermo-plastics Authors: Otero Gruer, Fermín Enrique; Oller Martínez, Sergio Horacio; Martínez García, Javier; Salomón, Ramón Omar Abstract: Carbon nanotubes (CNTs), since their discovery by Lijima (S. Lijima, Nature, 354:56-58 (1991)), are considered a new generation of reinforcement. Their "nano" size structure makes them potentially free of defects, which provides them with excellent physical properties. There are two main nanotube types: single wall nanotubes (SWCNTs), which are made of a single wall tube; and multiwall nanotubes (MWCNTs), which consist in several concentric walls, one inside the other. A key factor for the reinforcement efficiency in a composite it is the interface bonding between the CNTs and the matrix. This work presents a new constitutive model to predict the mechanical performance of composites made of a thermo-plastic matrix reinforced with CNTs. The model takes into account explicitly the mechanical contribution of the interface between the matrix and the CNTs (F. Otero et. al., Comp Structures, 94:2920-2930 (2012)). The constitutive model is based in the mixing theory, which obtains the composite performance from the response of each constituent component, each one simulated with its own constitutive law. The model has been implemented into an in-house FEM code: PLCd. As an application example, this code is used to predict the mechanical properties of a straight beam with different material configurations. In this case, a viscoelastic constitutive model is proposed for the polymeric matrix. The viscous response within the elastic range of the materials is studied. This response shows a high capacity of energy dissipation in composites reinforced with MWCNTs. Thu, 16 May 2013 08:54:11 GMT http://hdl.handle.net/2117/19274 2013-05-16T08:54:11Z Otero Gruer, Fermín Enrique; Oller Martínez, Sergio Horacio; Martínez García, Javier; Salomón, Ramón Omar no Carbon nanotubes (CNTs), since their discovery by Lijima (S. Lijima, Nature, 354:56-58 (1991)), are considered a new generation of reinforcement. Their "nano" size structure makes them potentially free of defects, which provides them with excellent physical properties. There are two main nanotube types: single wall nanotubes (SWCNTs), which are made of a single wall tube; and multiwall nanotubes (MWCNTs), which consist in several concentric walls, one inside the other. A key factor for the reinforcement efficiency in a composite it is the interface bonding between the CNTs and the matrix. This work presents a new constitutive model to predict the mechanical performance of composites made of a thermo-plastic matrix reinforced with CNTs. The model takes into account explicitly the mechanical contribution of the interface between the matrix and the CNTs (F. Otero et. al., Comp Structures, 94:2920-2930 (2012)). The constitutive model is based in the mixing theory, which obtains the composite performance from the response of each constituent component, each one simulated with its own constitutive law. The model has been implemented into an in-house FEM code: PLCd. As an application example, this code is used to predict the mechanical properties of a straight beam with different material configurations. In this case, a viscoelastic constitutive model is proposed for the polymeric matrix. The viscous response within the elastic range of the materials is studied. This response shows a high capacity of energy dissipation in composites reinforced with MWCNTs. http://hdl.handle.net/2117/19251 Title: The particle finite element method (PFEM): an effective numerical technique for solving marine, naval and harbour engineering problems Authors: Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Celigueta Jordana, Miguel Ángel; Suárez Arroyo, Benjamín Abstract: We present some developments in the Particle Finite Element Method (PFEM) for the solution of complex coupled problems in marine, naval and harbour engineering involving fluid-soil-structure interaction (FSSI). The PFEM uses an updated Lagrangian description to model the motion of nodes (particles) in a continuum domain containing fluid, soil/rock and structures subdomains. A mesh connects the nodes defining the discretized domain where the governing equations for each of the constituent materials are solved with the FEM. The stabilization for dealing with an incompressibility material is introduced via the finite calculus (FIC) method. An incremental iterative scheme for solving the non linear transient FSSI problem is described. The procedure to model frictional contact conditions and material erosion at fluid-solid and solid-solid interfaces is described. We present examples of application of the PFEM to solve FSSI problems in marine, naval and harbour engineering such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the sinking of ships and the collision of a ship with ice blocks. Wed, 15 May 2013 13:36:16 GMT http://hdl.handle.net/2117/19251 2013-05-15T13:36:16Z Oñate Ibáñez de Navarra, Eugenio; Idelsohn Barg, Sergio Rodolfo; Celigueta Jordana, Miguel Ángel; Suárez Arroyo, Benjamín no We present some developments in the Particle Finite Element Method (PFEM) for the solution of complex coupled problems in marine, naval and harbour engineering involving fluid-soil-structure interaction (FSSI). The PFEM uses an updated Lagrangian description to model the motion of nodes (particles) in a continuum domain containing fluid, soil/rock and structures subdomains. A mesh connects the nodes defining the discretized domain where the governing equations for each of the constituent materials are solved with the FEM. The stabilization for dealing with an incompressibility material is introduced via the finite calculus (FIC) method. An incremental iterative scheme for solving the non linear transient FSSI problem is described. The procedure to model frictional contact conditions and material erosion at fluid-solid and solid-solid interfaces is described. We present examples of application of the PFEM to solve FSSI problems in marine, naval and harbour engineering such as the motion of rocks by water streams, the stability of breakwaters and constructions under sea waves, the sinking of ships and the collision of a ship with ice blocks. http://hdl.handle.net/2117/19197 Title: Reactions of fly ash with calcium aluminate cement and calcium sulphate Authors: Fernández Carrasco, Lucía; Vázquez Ramonich, Enric Abstract: The hydration processes in the ternary system fly ash/calcium aluminate cement/calcium sulphate (FA/CAC/C$) at 20 °C were investigated; six compositions from the ternary system FA/CAC/C$ were selected for this study. The nature of the reaction products in these pastes were analysed by X-ray diffraction (XRD) and infrared spectroscopy (FTIR). At four days reaction time, the main hydration reaction product in these pastes was ettringite and the samples with major initial CAC presented minor ettringite but calcium aluminates hydrates. The amount of ettringite developed in the systems has no direct relation with the initial components. Tue, 14 May 2013 10:28:31 GMT http://hdl.handle.net/2117/19197 2013-05-14T10:28:31Z Fernández Carrasco, Lucía; Vázquez Ramonich, Enric no The hydration processes in the ternary system fly ash/calcium aluminate cement/calcium sulphate (FA/CAC/C$) at 20 °C were investigated; six compositions from the ternary system FA/CAC/C$ were selected for this study. The nature of the reaction products in these pastes were analysed by X-ray diffraction (XRD) and infrared spectroscopy (FTIR). At four days reaction time, the main hydration reaction product in these pastes was ettringite and the samples with major initial CAC presented minor ettringite but calcium aluminates hydrates. The amount of ettringite developed in the systems has no direct relation with the initial components. http://hdl.handle.net/2117/19189 Title: Supercritical Carbonation of Calcium Aluminate Cement Authors: Fernández Carrasco, Lucía; Miravitlles, C; Rius, J. Abstract: The microstructural changes occurring during supercritical carbonation (scCO2) of calcium aluminate cement (CAC) and changes to its strength have been investigated. Cylindrical specimens of CAC cured at different temperatures were prepared and then subjected to scCO2. It is shown that CAC carbonation in supercritical conditions is accelerated with a positive effect on the compressive strength. Due to the scCO2 treatment, both conversion and alkaline hydrolysis are avoided. The best behaviour of the studied specimens was attained for samples cured at 25 °C. The residual compounds after the scCO2 process, i.e. monocalcium aluminate, calcium carbonate and aluminium hydroxide are durable in normal ambient conditions. Complete carbonation of CAC is particularly important for the reinforcement of CAC with polymer fibres to improve its mechanical strength. Tue, 14 May 2013 07:52:00 GMT http://hdl.handle.net/2117/19189 2013-05-14T07:52:00Z Fernández Carrasco, Lucía; Miravitlles, C; Rius, J. no The microstructural changes occurring during supercritical carbonation (scCO2) of calcium aluminate cement (CAC) and changes to its strength have been investigated. Cylindrical specimens of CAC cured at different temperatures were prepared and then subjected to scCO2. It is shown that CAC carbonation in supercritical conditions is accelerated with a positive effect on the compressive strength. Due to the scCO2 treatment, both conversion and alkaline hydrolysis are avoided. The best behaviour of the studied specimens was attained for samples cured at 25 °C. The residual compounds after the scCO2 process, i.e. monocalcium aluminate, calcium carbonate and aluminium hydroxide are durable in normal ambient conditions. Complete carbonation of CAC is particularly important for the reinforcement of CAC with polymer fibres to improve its mechanical strength. http://hdl.handle.net/2117/19180 Title: Blending of radar and gauge rainfall measurements: a preliminary analysis of the impact of radar errors Authors: Sempere Torres, Daniel; Berenguer Ferrer, Marc; Velasco Forero, Carles Abstract: Several methodologies have been proposed to combine radar and raingauge measurements with the aim of generating improved quantitative precipitation estimates (QPEs). These methods are based on interpolating point raingauge measurements (implicitly assumed to be “the truth”) and benefiting from the structure of the rainfall field as depicted by the radar. The use of a non-parametric approach based on radar measurements has been recently demonstrated, showing the benefits in the interpolation of raingauge measurements under the hypotheses of the Kriging approach. Several experiments have been carried out over a large number of cases and a variety of regions, Kriging with an external drift (i.e. the radar description of the rainfall field) being the approach showing more robust and (overall) better performance. Here, the impact of the discrepancies between two almost-collocated radars on the blended QPE fields was investigated. Mon, 13 May 2013 13:09:06 GMT http://hdl.handle.net/2117/19180 2013-05-13T13:09:06Z Sempere Torres, Daniel; Berenguer Ferrer, Marc; Velasco Forero, Carles no QPE, radar-raingauge blending, spatial variability of rainfall, radar errors, radar calibration Several methodologies have been proposed to combine radar and raingauge measurements with the aim of generating improved quantitative precipitation estimates (QPEs). These methods are based on interpolating point raingauge measurements (implicitly assumed to be “the truth”) and benefiting from the structure of the rainfall field as depicted by the radar. The use of a non-parametric approach based on radar measurements has been recently demonstrated, showing the benefits in the interpolation of raingauge measurements under the hypotheses of the Kriging approach. Several experiments have been carried out over a large number of cases and a variety of regions, Kriging with an external drift (i.e. the radar description of the rainfall field) being the approach showing more robust and (overall) better performance. Here, the impact of the discrepancies between two almost-collocated radars on the blended QPE fields was investigated. http://hdl.handle.net/2117/19178 Title: Proyecto y construccion del cierre del ábside de la Sagrada Familia Authors: Buxadé, Carles; Gómez Serrano, José; Espel, Ramon; Grima, Rosa; Buxadé, Agata; Ferrando, Ramon; Aguado de Cea, Antonio Mon, 13 May 2013 11:08:52 GMT http://hdl.handle.net/2117/19178 2013-05-13T11:08:52Z Buxadé, Carles; Gómez Serrano, José; Espel, Ramon; Grima, Rosa; Buxadé, Agata; Ferrando, Ramon; Aguado de Cea, Antonio no Sagrada Familia, Gaudí, construcción, ábside, estructura y materiales http://hdl.handle.net/2117/19168 Title: Spectral properties of the connectivity matrix and the SIS-epidemic threshold for mid-size metapopulations Authors: Juher Barrot, David; Mañosa Fernández, Víctor Abstract: We consider the spread of an infectious disease on a heterogeneous metapopulation defined by any (correlated or uncorrelated) network. The infection evolves under transmission, recovering and migration mechanisms. We study some spectral properties of a connectivity matrix arising from the continuous-time equations of the model. In particular we show that the classical sufficient condition of instability for the disease-free equilibrium, well known for the particular case of uncorrelated networks, works also for the general case. We give also an alternative condition that yields a more accurate estimation of the epidemic threshold for correlated (either assortative or dissortative) networks Description: Preprint version of the paper Mon, 13 May 2013 08:19:06 GMT http://hdl.handle.net/2117/19168 2013-05-13T08:19:06Z Juher Barrot, David; Mañosa Fernández, Víctor no SIS epidemics, Complex networks, Spectral properties, Connectivity matrix, Disease-free equilibrium. We consider the spread of an infectious disease on a heterogeneous metapopulation defined by any (correlated or uncorrelated) network. The infection evolves under transmission, recovering and migration mechanisms. We study some spectral properties of a connectivity matrix arising from the continuous-time equations of the model. In particular we show that the classical sufficient condition of instability for the disease-free equilibrium, well known for the particular case of uncorrelated networks, works also for the general case. We give also an alternative condition that yields a more accurate estimation of the epidemic threshold for correlated (either assortative or dissortative) networks