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Modeling of gas migration through low-permeability clay rock using information on pressure and deformation from fast air injection tests

  • Senger, Rainer
  • Romero Morales, Enrique Edgar
  • Marschall, Paul
The characterization of gas migration through low-permeability clay formations has been a focus of R&D programs for radioactive waste disposal, which is also of great importance for shale gas exploration, cap-rock behavior of hydrocarbon reservoirs, and (Formula presented.) sequestration. Laboratory tests have been performed on Opalinus Clay, a Mesozoic claystone that is being investigated in Switzerland as a potential host rock for the storage of nuclear waste. The laboratory program included specific water and air injections tests, as well as oedometer and isotropic compression tests. Undisturbed core samples have been retrieved from a shallow borehole in the Mont Terri Underground Research Laboratory (URL) and from a deep borehole in northern Switzerland. For the shallow cores from Mont Terri URL, largely linear-elastic deformations associated with the gas injection test could be inferred and the change in void ratio was accounted for by the pore compressibility. The corresponding change in permeability was obtained from the results of the water tests, indicating a log-linear relation between permeability and porosity. The derived porosity change and the corresponding change in permeability were implemented in the standard TOUGH2 code, which reproduced the measured gas test results using fitted water retention data derived from laboratory measurements. Similar air injection tests performed on Opalinus Clay cores from the borehole at greater depth showed overall similar behavior, but at lower porosities, lower permeability values, and lower compressibility. These cases indicated nonlinear behavior which was implemented using an effective stress-dependent porosity change and the associated change in permeability. In addition, the anisotropy associated with the bedding planes of the clay formation was considered by assuming different properties for “soft” and “hard” layers to account for storage capacity for the injected gas prior to gas breakthrough. The computed change in the overall porosity could be compared to the measured axial deformation during the gas injection test and was used for calibration of the parameters describing the relationship between the effective stress and porosity, as well as the corresponding change in permeability and capillary pressure., Peer Reviewed
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Ground-level ozone concentration over Spain: an application of Kalman Filter post-processing to reduce model uncertainties

  • Sicardi, Valentina
  • Ortiz, Joana
  • Rincón, Ángel
  • Jorba Casellas, Oriol
  • Pay Pérez, M. Teresa
  • Gassó Domingo, Santiago
  • Baldasano Recio, José María
The CALIOPE air quality modelling system, namely WRF-ARW/HERMESEMEP/ CMAQ/BSC-DREAM8b, has been used to perform the simulation of ground level O3 concentration for the year 2004, over the Iberian Peninsula. We use this system to study 5 the daily ground-level O3 maximum. We investigate the use of a post-processing such as the Kalman Filter bias-adjustment technique to improve the simulated O3 maximum. The Kalman Filter bias-adjustment technique is a recursive algorithm to optimally estimate bias-adjustment terms from previous measurements and model results. The bias-adjustment technique is found to improve the simulated O3 maximum for the en10 tire year and the whole domain. The corrected simulation presents improvements in statistical indicators such as correlation, root mean square error, mean bias, standard deviation, and gross error. After the post-processing the exceedances of O3 concentration limits, as established by the European Directive 2008/50/CE, are better reproduced and the uncertainty of the modelling system is reduced from 20% to 7.5%. Such un15 certainty in the model results is under the established EU limit of the 50%. Significant improvements in the O3 average daily cycle and in its amplitude are also observed after the post-processing. The systematic improvements in the O3 maximum simulations suggest that the Kalman Filter post-processing method is a suitable technique to reproduce accurate estimate of ground-level O3 concentration., Peer Reviewed
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Injection molding optimization in order to improve the dispersion of the nanoclays

  • Pascual Cuenca, Enric
Injection molding is the most commonly manufacturing process used for the fabrication of plastic parts. Different products can be manufactured using injection molding which vary greatly in their size, complexity and application. Automotive industry is the most important sector that uses this technology. A wide variety of additives are used to modify the raw polymers and achieve new properties. Nanoadditives and nanoclays specifically, are used to improve various physical properties, such as reinforcement, synergistic flame retardant and barrier. This work is focused on the study the different parameters in the injection molding process in order to optimize the process using a specific grade of polypropylene and a specific grade of nanoclay. The main goal of the project is to improve the flexural modulus of the studied part using a lineal model taking into account the behavior the selected parameters.
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Evaluación de tecnologías

  • Barceló Garcia, Miquel
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Tools to measure the technological capabilities of the aerospace industry

  • Castillón-Barraza, Acela
  • González-Angeles, Alvaro
  • Lara-Chavez, Fernando
  • Mendoza-Muñoz, Ismael
Purpose: The following article describes steps along with a mathematical model to determine the technological capability of the aerospace industry of Mexicali in the area of design (ICTD) and manufacturing (ICTM). Design/methodology/approach: This model was performed by weighted variables using factor analysis to identify technological capacities of Small and medium-sized enterprises (SMEs) and compare them with those that must be accomplish to become suppliers for transnational industry (TNCs). Findings: The results suggest that SMEs must realize a comparative table QFD of their current capabilities and the requirements established by transnational corporations, to create a strategic plan that includes; certifications (AS 9000, NAP CAP, Belts, ISO, Six Sigma), software acquisition and updated equipment necessary for reducing the technological gap. Additionally, it is recommended the integration of clusters of enterprises SMEs for the strengthening of technological capacities. Originality/value: Up to we know, there is not similar model for measuring technological capabilities of aerospace industry., Peer Reviewed
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Motion planning and control of unmanned aerial vehicles, Planificación del movimiento y control de vehículos aéreos no tripulados, Planificació del moviment i control de vehicles aeris no tripulat

  • Carbó Cubero, Paula
The emerging autonomous industry has recently allowed the fast and low cost production of unmanned aerial vehicles (UAVs). The autonomy of these robots could have plenty of applications in today's society.The first challenge, therefore, is making autonomous vehicles move around safely in dynamic environments and optimising the path they should follow. This project focuses precisely in understanding all the parts that have to come together in order to achieve this purpose. This is done by making a mathematical model for the UAV, a study of the sensors needed to estimate the UAV?s state, then designing a controller for the trajectory tracking and using an artificial potential field function for the navigation control. Computer simulations are performed to test the theoretical findings and evaluate the proposed methods. The last part of this thesis is an empirical study on how this project could be brought to real life, by means of implementing together all the parts studied separately in an UAV., La emergente industria autónoma ha permitido recientemente la producción rápida y de bajo coste de vehículos aéreos no tripulados (UAV). La autonomía de estos robots podría tener muchas aplicaciones en la sociedad actual. El primer desafío, por lo tanto, es conseguir que los vehículos autónomos se muevan de forma segura en entornos dinámicos, optimizando el camino que deberían seguir. Este proyecto se enfoca precisamente en comprender todas las partes que deben unirse para lograr este propósito. Esto se hace mediante un modelo matemático para el UAV, un estudio de los sensores necesarios para estimar el estado del UAV, luego diseñando un controlador para el seguimiento de trayectoria y trabajando con una función de campo potencial artificial para el control de la navegación. Simulaciones permiten probar los hallazgos teóricos y evaluar los métodos propuestos. La última parte de esta tesis es un estudio empírico sobre cómo este proyecto podría llevarse a la vida real, mediante la implementación conjunta de todas las partes estudiadas por separado en un UAV., L'emergent indústria autònoma ha permès recentment la producció ràpida i de baix cost de vehicles aeris no tripulats (UAV). L'autonomia d'aquests robots podria tenir una gran varietat d'aplicacions en la societat actual. El primer repte, per tant, és que els vehicles autònoms es moguin amb seguretat en entorns dinàmics i que optimitzin el camí que han de seguir. Aquest projecte se centra precisament en entendre totes les parts que s'han de reunir per aconseguir aquest objectiu. Això es fa elaborant un model matemàtic per al UAV, un estudi dels sensors necessaris per estimar l'estat del UAV, dissenyant un controlador per al seguiment de trajectòria i utilitzant una funció de camp potencial artificial per al control de la navegació. Les simulacions permeten provar les troballes teòriques i avaluar els mètodes proposats. L'última part d'aquesta tesi és un estudi empíric sobre com aquest projecte es podria portar a la vida real, mitjançant la implementació conjunta de totes les parts estudiades per separat en un UAV.
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Análisis del impacto medioambiental del transporte marítimo en aguas polares e implicaciones del código internacional para los buques que operan en aguas polares (código polar)

  • Tortras De La Cruz, Pau
Debido al cambio climático, cada vez más es una realidad el uso de las rutas polares para el tránsito de buques. El deshielo está abriendo nuevas posibilidades en el Ártico y los buques han empezado a navegar por estas rutas como alternativa a la Ruta Marítima del Sur, que pasa por el Canal de Suez. El tiempo y el combustible que se ahorran los buques son los principales motivos. Este trabajo analiza las rutas árticas en los siguientes aspectos: ventajas e inconvenientes, legislación que actualmente las regula (Código Polar) y su viabilidad actual y futura. Todo esto con el fin de ver el impacto medioambiental del transporte marítimo sobre estas rutas y determinar si están preparadas para soportar un gran número de tránsitos marítimos. El conocimiento de la realidad de estas rutas y los peligros que conlleva su uso marino para el tránsito de buques, nos permitirá determinar las acciones a realizar para disponer de unas vías de navegación seguras para la tripulación, pasajeros y el medio ambiente. Es decir, si tienen la suficiente infraestructura para una navegación segura, puertos de aprovisionamiento y/o de refugio, instalaciones de recepción de aguas residuales, equipos de rescate con respuestas de tiempo pequeñas, así como una ley para prevenir la contaminación.
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Economic evaluation of Nearly Zero Energy Cities

  • Villa Arrieta, Manuel Ricardo
  • Sumper, Andreas
As a contribution to the study of the urban energy transition, this paper proposes a novel model of energy-economic evaluation of the cities self-sufficiency and presents its application in the form of a case study. The objective of this study was to analyse the scope of the investment in the photovoltaic self-consumption of buildings in order to promote the creation of Prosumers communities within the cities. The operation of this model is based on the scalability of the Nearly Zero Energy concept from buildings to cities and seeks to evaluate Nearly Zero Energy Cities (nZEC): cities made up of Nearly Zero Energy Buildings (nZEB) and other installations of distributed generation to cover their energy demand by use of local renewable resources to the detriment of external resources. By using public data, we apply this model with the aim of economically evaluating the investment of six packages of energy rehabilitation and photovoltaic self-consumption in 17% of the residential buildings (37,800) in the city of Barcelona. To do this, we simulated 37¿years of electricity distribution among Consumers, Producers and a hypothetical peer-to-peer community of Prosumers during the period 2014–2050 in hourly time intervals. The results indicated that the photovoltaic self-consumption and the local markets of Prosumers help to reduce primary energy consumption, the energy costs, and the CO2 emissions.
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Automatic microarchitectural pipelining

  • Galcerán Oms, Marc
  • Cortadella, Jordi
  • Bufistov, Dmitry
  • Kishinevsky, Michael
This paper presents a method for automatic microarchitectural pipelining of systems with loops. The original specification is pipelined by performing provably-correct transformations including conversion to a synchronous elastic form, early evaluation, inserting empty buffers, anti-tokens, and retiming. The design exploration is done by solving an optimization problem followed by simulation of solutions. The method is explained on a DLX microprocessor example. The impact of different microarchitectural parameters on the performance is analyzed., Peer Reviewed
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