Corrosión de armaduras en el hormigón armado en ambiente marino aéreo

La presente tesis doctoral surge ante la necesidad de completar el estudio sobre la corrosión en el hormigón armado expuesto al ambiente marino iniciado por D. Miguel Ángel Bermúdez Odriozola en 2007 con la tesis doctoral con título “Corrosión de las armaduras del hormigón armado en ambiente marino: zona de carrera de mareas y zona sumergida”. Una vez realizado el estudio bibliográfico, se ha planteado un estudio experimental en el que se analizan cuatro muelles de distintas edades y localizados en distintos lugares de la geografía española. Uno de ellos contiene adiciones en el hormigón. Una vez inspeccionados, se extraen testigos de cada uno de ellos con el fin de realizar ensayos de caracterización y se analizan sus resultados en paralelo con los coeficientes de difusión. Uno se los objetivos ha sido comprobar el mejor método de ensayo que permita controlar la durabilidad del hormigón en ambiente IIIa. La tesis que se presenta ha demostrado la efectividad del ensayo de penetración de agua para discriminar los hormigones que presentarán un buen comportamiento frente a la difusión de cloruros y por tanto para predecir la vida útil de la estructura. Asimismo, otro objetivo ha sido valorar el uso de adiciones en el hormigón y cómo afectan a la mejora del comportamiento del hormigón expuesto al ambiente marino. Se han obtenido valores del coeficiente de eficacia de cenizas volantes y humo de sílice frente a la difusión de cloruros, muy superiores a los actualmente considerados en términos de resistencia. El ambiente marino aéreo engloba estructuras situadas en primera línea de costa así como aquellas que se sitúan hasta 5km de distancia de la línea del mar. La investigación realizada ha demostrado la necesidad de establecer una nueva subdivisión en este ambiente introduciendo la zona Spray, siguiendo criterios internacionales, que permita diferenciar la zona más desfavorable del mismo que comprende las estructuras ubicadas sobre el nivel del mar tal como los tableros de pantalanes portuarios estudiados. Se han analizado en profundidad los valores del contenido de cloruros en superficie de hormigón en los diferentes tipos de ambiente marino recogidos por la Instrucción EHE- 08 contrastando los requisitos normativos. Como conclusión se han hecho nuevas propuestas normativas que afectan al ambiente sumergido y al ambiente marino aéreo (zona spray). Asimismo se ha realizado un análisis en profundidad de la concentración crítica de cloruros recogida por la Instrucción EHE-08, a partir de los datos obtenidos en estructuras reales. Se ha evaluado el ensayo de resistividad para estimar el valor del coeficiente de difusión de cloruros. Este ensayo ha demostrado su efectividad para discriminar hormigones con adiciones y con muy baja penetración de agua, si bien no resulta sensible para detectar hormigones con elevada permeabilidad. Finalmente en la tesis se ha obtenido un modelo de difusión de cloruros (a/c-D) en ambiente marino aéreo a fin de poder estimar la difusión de cloruros en el hormigón a partir de un requisito normativo como es la relación a/c. This Thesis is focussed to complete the previous study on the corrosion of reinforced concrete exposed to marine environment, carried out by Dr. Miguel Ángel Bermúdez Odrizola in 2007. That Thesis title was “Corrosion of concrete reinforcement located in marine environment: tidal zone and submerged zone”. After the literature review presented in the State of the Art, an experimental programme was carried out. Four docks of different ages and locations have been studied, one of them was a fly ash concrete. The structures were inspected on site and several cores extracted in order to develop characterization tests and obtain diffusion profiles at the laboratory. One of the objectives has been to check the best laboratory test method to control concrete durability when exposed to atmospheric marine environment. This Thesis has proven the effectiveness of the water penetration test to differentiate concretes well behaved against chloride diffusion and also to predict the structure service life. Another objective has been to study the effect of mineral additions in concrete and how they improve the durability of concrete in this environment. Efficiency factors have been obtained for fly ashes and silica fume, much higher than those consider for strength. According to the Spanish Concrete Code EHE 08, the atmospheric marine environment includes structures located at the cost, from the sea line up to 5km inland. The research conducted has shown the need to consider a spray zone which is the most unfavourable area of the atmospheric environment, affecting structures over the sea level as the decks of the wharves here studied. Surface chloride contents of structures in the different marine environments have been deeply analysed, checking the actual standard limits. As a conclusion, new normative values have been proposed for submerged and atmospheric zone (spray zone). A complete analysis of the chloride threshold concentration from the data obtained in real structures has also been performed. It has been evaluated the resistivity test as a tool to estimate the chloride diffusion coefficient. This test has proven effectiveness to discriminate concrete with mineral additions and low water penetration values, while it is not sensitive to detect concretes with high permeability. Finally, a chloride diffusion model (w/c) has been obtained in atmospheric marine environment in order to estimate the chloride diffusion of the concrete knowing a normative requirement as w/c.

Cartografía local y sistemas de información geográfica participativos como herramientas de consolidación de la identidad local en la planificación urbana y territorial

Una de las características de la cartografía y SIG Participativos (SIGP) es incluir en sus métodos a la sociedad civil para aportar contenidos cualitativos a la información de sus territorios. Sin embargo no sólo se trata de datos, sino de los efectos que pueden tener estas prácticas sobre el territorio y su sociedad. El acceso a esa información se ve reducida en contraste con el incremento de información difundida a través de servicios de visualización, geoinformación y cartografía on-line. Todo esto hace que sea necesario el análisis del alcance real de las metodologías participativas en el uso de Información Geográfica (IG) y la comparación desde distintos contextos geográficos. También es importante conocer los beneficios e inconvenientes del acceso a la información para el planeamiento; desde la visibilidad de muchos pueblos desapercibidos en zonas rurales y periféricas, hasta la influencia en programas de gobierno sobre la gestión del territorio pasando por el conocimiento local espacial. El análisis se centró en los niveles de participación de la sociedad civil y sus grados de accesibilidad a la información (acceso y uso), dentro del estudio de los SIGP, Participatory Mapping, además se estudió de los TIG (Tecnologías de Información Geográfica), cartografías on-line (geoweb) y plataformas de geovisualización espacial, como recursos de Neocartografía. En este sentido, se realizó un trabajo de campo de cartografía participativa en Bolivia, se evaluaron distintos proyectos SIGP en países del norte y sur (comparativa de contextos en países en desarrollo) y se analizaron los resultados del cruce de las distintas variables.(validación, accesibilidad, verificación de datos, valor en la planificación e identidad) La tesis considera que ambos factores (niveles de participación y grado de accesibilidad) afectan a la (i) validación, verificación y calidad de los datos, la (ii) valor analítico en la planificación, y al (iii) modelo de identidad de un lugar, y que al ser tratados de forma integral, constituyen el valor añadido que los SIGP pueden aportar para lograr una planificación efectiva. Asimismo se comprueba, que la dimensión participativa en los SIGP varía según el contexto, la centralización de sus actores e intereses sectoriales. La información resultante de las prácticas SIGP tiende a estar restringida por la falta de legislaciones y por la ausencia de formatos estándar, que limitan la difusión e intercambio de la información. Todo esto repercute en la efectividad de una planificación estratégica y en la viabilidad de la implementación de cualquier proyecto sobre el territorio, y en consecuencia sobre los niveles de desarrollo de un país. Se confirma la hipótesis de que todos los elementos citados en los SIGP y mapeo participativo actuarán como herramientas válidas para el fortalecimiento y la eficacia en la planificación sólo si están interconectadas y vinculadas entre sí. Se plantea una propuesta metodológica ante las formas convencionales de planificación (nueva ruta del planeamiento; que incluye el intercambio de recursos y determinación participativa local antes de establecer la implementación), con ello, se logra incorporar los beneficios de las metodologías participativas en el manejo de la IG y los SIG (Sistemas de Información Geográfica) como instrumentos estratégicos para el desarrollo de la identidad local y la optimización en los procesos de planeamiento y estudios del territorio. Por último, se fomenta que en futuras líneas de trabajo los mapas de los SIGP y la cartografía participativa puedan llegar a ser instrumentos visuales representativos que transfieran valores identitarios del territorio y de su sociedad, y de esta manera, ayudar a alcanzar un mayor conocimiento, reconocimiento y valoración de los territorios para sus habitantes y sus planificadores. ABSTRACT A feature of participatory mapping and PGIS is to include the participation of the civil society, to provide qualitative information of their territories. However, focus is not only data, but also the effects that such practices themselves may have on the territory and their society. Access to this information is reduced in contrast to the increase of information disseminated through visualization services, geoinformation, and online cartography. Thus, the analysis of the real scope of participatory methodologies in the use of Geographic Information (GI) is necessary, including the comparison of different geographical contexts. It is also important to know the benefits and disadvantages of access to information needed for planning in different contexts, ranging from unnoticed rural areas and suburbs to influence on government programs on land management through local spatial knowledge. The analysis focused on the participation levels of civil society and the degrees of accessibility of the information (access and use) within the study of Participatory GIS (PGIS). In addition, this work studies GIT (Geographic Information Technologies), online cartographies (Geoweb) and platforms of spatial geovisualization, as resources of Neocartography. A participatory cartographic fieldwork was carried out in Bolivia. Several PGIS projects were evaluated in Northern and Southern countries (comparatively with the context of developing countries), and the results were analyzed for each these different variables. (validation, accessibility, verification,value, identity). The thesis considers that both factors (participation levels and degree of accessibility) affect the (i) validation, verification and quality of the data, (ii) analytical value for planning, and (iii) the identity of a place. The integrated management of all the above cited criteria constitutes an added value that PGISs can contribute to reach an effective planning. Also, it confirms the participatory dimension of PGISs varies according to the context, the centralization of its actors, and to sectorial interests. The resulting information from PGIS practices tends to be restricted by the lack of legislation and by the absence of standard formats, which limits in turn the diffusion and exchange of the information. All of this has repercussions in the effectiveness of a strategic planning and in the viability of the implementation of projects about the territory, and consequentially in the land development levels. The hypothesis is confirmed since all the described elements in PGISs and participatory mapping will act as valid tools in strengthening and improving the effectivity in planning only if they are interconnected and linked amongst themselves. This work, therefore, suggests a methodological proposal when faced with the conventional ways of planning: a new planning route which includes the resources exchange and local participatory determination before any plan is established -. With this, the benefits of participatory methodologies in the management of GI and GIS (Geographic Information Systems) is incorporated as a strategic instrument for development of local identity and optimization in planning processes and territory studies. Finally, the study outlines future work on PGIS maps and Participatory Mapping, such that these could eventually evolve into visual representative instruments that transfer identity values of the territory and its society. In this way, they would contribute to attain a better knowledge, recognition, and appraisement of the territories for their inhabitants and planners.

Real-time visualization of intracellular hydrodynamics in single living cells

Intracellular water concentrations in single living cells were visualized by nonlinear coherent anti-Stokes Raman scattering (CARS) microscopy. In combination with isotopic exchange measurements, CARS microscopy allowed the real-time observation of transient intracellular hydrodynamics at a high spatial resolution. Studies of the hydrodynamics in the microorganism Dictyostelium discoideum indicated the presence of a microscopic region near the plasma membrane where the mobility of water molecules is severely restricted. Modeling the transient hydrodynamics eventuated in the determination of cell-specific cytosolic diffusion and plasma membrane permeability constants. Our experiments demonstrate that CARS microscopy offers an invaluable tool for probing single-cell water dynamics.

Single-molecule spectroscopy of the β2 adrenergic receptor: Observation of conformational substates in a membrane protein

Single-molecule studies of the conformations of the intact β2 adrenergic receptor were performed in solution. Photon bursts from the fluorescently tagged adrenergic receptor in a micelle were recorded. A photon-burst algorithm and a Poisson time filter were implemented to characterize single molecules diffusing across the probe volume of a confocal microscope. The effects of molecular diffusion and photon number fluctuations were deconvoluted by assuming that Poisson distributions characterize the molecular occupation and photon numbers. Photon-burst size histograms were constructed, from which the source intensity distributions were extracted. Different conformations of the β2 adrenergic receptor cause quenching of the bound fluorophore to different extents and hence produce different photon-burst sizes. An analysis of the photon-burst histograms shows that there are at least two distinct substates for the native adrenergic membrane receptor. This behavior is in contrast to one peak observed for the dye molecule, rhodamine 6G. We test the reliability and robustness of the substate number determination by investigating the application of different binning criteria. Conformational changes associated with agonist binding result in a marked change in the distribution of photon-burst sizes. These studies provide insight into the conformational heterogeneity of G protein-coupled receptors in the presence and absence of a bound agonist.

QSAR e dinâmica molecular no estudo de sistemas biomoleculares: predição da atividade biológica de antagonistas do receptor sigma-1 e simulações de bicamadas lipídicas

Diferentes abordagens teóricas têm sido utilizadas em estudos de sistemas biomoleculares com o objetivo de contribuir com o tratamento de diversas doenças. Para a dor neuropática, por exemplo, o estudo de compostos que interagem com o receptor sigma-1 (Sig-1R) pode elucidar os principais fatores associados à atividade biológica dos mesmos. Nesse propósito, estudos de Relações Quantitativas Estrutura-Atividade (QSAR) utilizando os métodos de regressão por Mínimos Quadrados Parciais (PLS) e Rede Neural Artificial (ANN) foram aplicados a 64 antagonistas do Sig-1R pertencentes à classe de 1-arilpirazóis. Modelos PLS e ANN foram utilizados com o objetivo de descrever comportamentos lineares e não lineares, respectivamente, entre um conjunto de descritores e a atividade biológica dos compostos selecionados. O modelo PLS foi obtido com 51 compostos no conjunto treinamento e 13 compostos no conjunto teste (r² = 0,768, q² = 0,684 e r²teste = 0,785). Testes de leave-N-out, randomização da atividade biológica e detecção de outliers confirmaram a robustez e estabilidade dos modelos e mostraram que os mesmos não foram obtidos por correlações ao acaso. Modelos também foram gerados a partir da Rede Neural Artificial Perceptron de Multicamadas (MLP-ANN), sendo que a arquitetura 6-12-1, treinada com as funções de transferência tansig-tansig, apresentou a melhor resposta para a predição da atividade biológica dos compostos (r²treinamento = 0,891, r²validação = 0,852 e r²teste = 0,793). Outra abordagem foi utilizada para simular o ambiente de membranas sinápticas utilizando bicamadas lipídicas compostas por POPC, DOPE, POPS e colesterol. Os estudos de dinâmica molecular desenvolvidos mostraram que altas concentrações de colesterol induzem redução da área por lipídeo e difusão lateral e aumento na espessura da membrana e nos valores de parâmetro de ordem causados pelo ordenamento das cadeias acil dos fosfolipídeos. As bicamadas lipídicas obtidas podem ser usadas para simular interações entre lipídeos e pequenas moléculas ou proteínas contribuindo para as pesquisas associadas a doenças como Alzheimer e Parkinson. As abordagens usadas nessa tese são essenciais para o desenvolvimento de novas pesquisas em Química Medicinal Computacional.

Las TIC al servicio del conocimiento avanzado multilingüe: la Biblioteca Digital Plurilingüe del Mediterráneo-IVITRA

Este estudio analiza la importancia de las TIC al servicio de las bibliotecas en general y, en concreto, el potencial de las bibliotecas digitales. En este trabajo se reflexiona sobre la importancia de las bibliotecas digitales no sólo como repositorios de contenidos, sino también como centros de creación de conocimiento. Se reflexiona sobre la importancia de la constitución de bibliotecas digitales especializadas en áreas culturales relacionadas y sobre el hecho de que sean multilingües, a fin de preservar los contenidos en sus lenguas originales, al tiempo que debe trabajarse con la traducción multilingüe (de y a muchas lenguas) como herramienta fundamental para la mejora de la difusión y conocimiento del patrimonio que se contiene en tales bibliotecas. En este sentido se explican las características de la Biblioteca Digital Plurilingüe del Mediterráneo-IVITRA.

The Arab Spring: A Litmus Test for the EU’s Women’s Rights Policy in the Euro-Mediterranean Area? Bruges Regional Integration & Global Governance Paper 1/2013

The promotion of women’s rights is described as a priority within the external action of the European Union (EU). As a result of the Arab Spring uprisings which have been ongoing since 2011, democracy and human rights have been pushed to the forefront of European policy towards the Euro-Mediterranean region. The EU could capitalise on these transformations to help positively reshape gender relations or it could fail to adapt. Thus, the Arab Spring can be seen to serve as a litmus test for the EU’s women’s rights policy. This paper examines how and to what extent the EU diffuses women’s rights in this region, by using Ian Manners’ ‘Normative Power Europe’ as the conceptual framework. It argues that while the EU tries to behave as a normative force for women’s empowerment by way of ‘informational diffusion’, ‘transference’ ‘procedural diffusion’ and ‘overt diffusion’; its efforts could, and should, be strengthened. There are reservations over the EU’s credibility, choice of engagement and its commitment in the face of security and ideological concerns. Moreover, it seems that the EU focuses more intently on women’s political rights than on their social and economic freedoms.

Analysing the Contribution of Business Services to European Economic Growth. Bruges European Economic Research (BEER) Papers 9/February 2007

The sector business services contributes directly and indirectly to aggregate economic growth in Europe. The direct contribution comes from the sector’s own dynamism. Though the business-services industry appears to be characterised by strong cyclical volatility, there was also a strong structural growth. Business services actually generated more than half of total net employment growth in the European Union since the second half of the 1990s. Apart from this direct growth contribution, the sector also contributed in an indirect way to economic growth by generating knowledge and productivity spill-overs for other industries. The knowledge role of business services is reflected in its employment characteristics. The business-services industry created spill-overs in three ways: original innovations, knowledge diffusion, and the reduction of human capital indivisibilities at firm level. The share of knowledge-intensive business services in the intermediate inputs of the total economy has risen sharply in the last decade. Firm-level scale diseconomies with regard to knowledge and skill inputs are reduced by external deliveries of such inputs, thereby exploiting positive external scale economies. The process goes along with an increasingly complex social division of labour between economic sectors. The European business-services industry itself is characterised by a relatively weak productivity growth. Does this contribute to growth stagnation tendencies à la the socalled “Baumol disease”? The paper argues that there is no reason to expect this as long as the productivity and growth spill-overs from business services to other sectors are large enough. Finally, the paper concludes by suggesting several policy elements that could boost the role of business services in European economic growth. This might to achieve some of the ambitious Lisbon goals with respect to employment, productivity and innovation.

Environmental status of the Lake Michigan region /

Vols. 7, 9 and 15, issued in 1974, prepared for the U. S. Atomic Energy Commission; vols. issued 1975- prepared for the U. S. Energy Research and Development Administration.

A unique behavior of sub-critical hydrocarbon permeability in activated carbon at low pressures

In our study on sub-critical hydrocarbon permeation in activated carbon, a minimum in the total permeability (B-T) at low pressure has been observed for only long-chain hydrocarbons such as n-hexane and n-heptane. Such an observation suggests that the minimum appearance depends on the properties of permeating vapors as well as the porous medium. In this paper a permeation model is presented to explain the minimum behavior with the allowance of the collision-reflection factor in the Knudsen diffusivity to be a function of surface loading. Surface diffusion was found to be very significant compared to other transport mechanisms such as Knudsen diffusion and gaseous viscous flow at low pressures. Since the gaseous viscous flow contributes negligibly to the B, at low pressures, the minimum appearance in the B, is mainly attributed to the interplay between Knudsen diffusion and surface diffusion. Also, the molecular structure of adsorbates plays an important role in the minimum appearance.

Permeability of subcritical hydrocarbons in activated carbon

A new diffusion and flow model is presented to describe the behavior of hydrocarbon vapors in activated carbon. The micro/mesopore size distribution (PSD) is obtained according to Do's method which consists of two sequential processes of pore layering and pore filling. This model uses the micro/meso PSD obtained from each adsorbate equilibrium isotherm, which reflects the dynamics behavior of adsorbing molecules through the solid. The initial rise in total permeability is mainly attributed to adsorbed-phase diffusion (that is, surface diffusion), whereas the decrease over reduced pressure of about 0.9 is attributed to the reduction of pore space available for gas phase diffusion and flow. A functional form of surface diffusivity is proposed and validated with experimental data. This model predicts well the permeability of condensable hydrocarbon vapors in activated carbon. (C) 2005 American Institute of Chemical Engineers.

Identification of three gene candidates for multicellular resistance in colon carcinoma

Solid tumours display elevated resistance to chemo- and radiotherapies compared to individual tumour derived cells. This so-called multicellular resistance (MCR) phenomenon can only be partly explained by reduced diffusion and altered cell cycle status; even fast growing cells on the surface of solid tumours display MCR. Multicellular spheroids (MCS) recapture this phenomenon ex vivo and here we compare gene expression in exponentially growing MCS with gene expression in monolayer culture. Using an 18,664 gene microarray, we identified 42 differentially expressed genes and three of these genes can be linked to potential mechanisms of MCR. A group of interferon response genes were also up-regulated in MCS, as were a number of genes that that are indicative of greater differentiation in three-dimensional cultures.

Mechanistic modelling of pilling. Part I: Detailing of mechanisms

Mechanistic models of pilling are discussed in general terms, and a framework for pilling simulations is thereby created. A fundamental flaw in earlier models of pilling is revealed. A more comprehensive model of fibre diffusion and withdrawal from the fabric is proposed, and this is solved in general terms to find the rate of fuzz growth. Fuzz wear-off and entanglement into pills are discussed. Fibre fatigue is introduced, and it is demonstrated that this potentially increases the rate of withdrawal of anchor fibres.

A mathematical model of integrin-mediated haptotactic cell migration

Haptotactic cell migration, a directed response to gradients of cell—extracellular matrix adhesion, is an important process in a number of biological phenomena such as wound healing and tumour cell invasion. Previously, mathematical models of haptotaxis have been developed on the premise that cells migrate in response to gradients in the density of the extracellular matrix. In this paper, we develop a novel mathematical model of haptotaxis which includes the adhesion receptors known as integrins and a description of their functional activation, local recruitment and protrusion as part of lamellipodia. Through the inclusion of integrins, the modelled cell matter is able to respond to a true gradient of cell–matrix adhesion, represented by functionally active integrins. We also show that previous matrix-mediated models are in fact a subset of the novel integrin-mediated models, characterised by specific choices of diffusion and haptotaxis coefficients in their model equations. Numerical solutions suggest the existence of travelling waves of cell migration that are confirmed via a phase plane analysis of a simplified model.

Global perspectives in Korean intercountry adoption

Policy and social work practice currently lack a theoretical framework that adequately explains the emergence, diffusion, and continuance of the intercountry adoption (ICA) phenomenon. Using South Korea as a case study and the application of actor network theory to the ICA phenomenon, this paper introduces a theoretical approach that allows an examination of the complex interrelationships between the global and local influences of a country's engagement in ICA. This theoretical approach provides a different way of understanding the phenomenon, which, in turn, can better inform policies and practice that affect children and families across the globe.