Arquitectura y estructura han ido siempre íntimamente ligadas, pero con la aparición del acero y el hormigón surgieron nuevas necesidades formales o estéticas. El Estilo Internacional se inclinó por separar la retícula estructural de los cerramientos. En cambio, la Escuela de Chicago forjó las bases de una arquitectura optimizada y racional. Frank Lloyd Wright, entre estas dos situaciones, optó por seguir las pautas naturales de los materiales, de forma “orgánica”, recuperando la integración entre los diferentes componentes de la arquitectura. Dentro del recorrido sobre el papel de la estructura en la historia de la arquitectura, parece apropiado detener el análisis en la obra de Frank Lloyd Wright y su particular utilización de la estructura. El Guggenheim Museum es el edificio que recoge muchas de las constantes, por lo que merece la pena estudiarlo analizándolo a través de su estructura. En este sentido, la figura de Jaroslav J. Polivka resulta de particular interés debido a la colaboración mantenida con Wright. De esta relación surgen en ocasiones las claves, no sólo de las soluciones concretas de la estructura, sino de los condicionantes finales dentro del conjunto arquitectónico / Architecture and structure have always been closely related, but the advent of the steel and reinforced concrete created new needs in the formal aspects. The International Style opted to separate the structural framework from the walls. On the other hand, the Chicago School forged the basis of a rational and optimized architecture. Between these two situations, Frank Lloyd Wright chose the approach of following the natural patterns of materials, in ¿organic¿ manner, recovering the interaction between the different elements of the architecture. Into the range about the role of the structure in the history of architecture, it seems appropriate to stop the analysis in the work of Frank Lloyd Wright and his particular use of structure. The Guggenheim Museum is the building that reflects many of the constants, so it is worth analyzing its structure. In this sense, the figure of Jaroslav J. Polivka has a particular interest because of his collaboration with Wright. From this relationship sometimes arise the keys, not just the specific solutions for the structure, but the final conditions within the architectural form. Key words Architecture, structure, Structural typologies, Frank Lloyd Wright, Jaroslav Joseph Polivka, Guggenheim Museum, Organic Architecture, Plates and shells, Cantilevers, Dendriform columns.

Les processus d’interaction solide-liquide régulent les mécanismes qui régissent la disponibilité des oligo-éléments en phase liquide. Dans cet article, ces processus ont été étudiés grâce à l'utilisation des éléments de terres rares (REE), car ils sont d'excellents traceurs des processus géochimiques. Le but de la première partie de ce travail était d'étudier la réactivité des particules volcaniques lors de l'interaction avec l'eau de la mer synthétique. Les résultats montrent que en dehors de la dissolution, qui est le processus principal, un procédé d'adsorption de surface se produit également, probablement sur la surface des cristaux nouvellement formé. La présence supposée de ces minéraux est suggéré par la variation temporelle de l'Y/Ho, des observations SEM et analyse XRD. Enfin, l'ajout des ligand dissous ne pas augmenter le taux de dissolution des particules volcaniques, mais modifiant la distribution de REE en phase liquide. Dans la deuxième partie de ce travail, l'étude des terres rares a été appliquée à un système humain. Ces éléments ont été utilisés, en fait, d'enquêter sur les fluides du poumon (BAL) chez les personnes exposées aux retombées de cendres volcaniques. Le résultat suggère que la co-précipitation du YLn-phosphates se produisent dans les poumons, à la suite de l'inhalation de particules volcaniques. Ce processus est confirmé par des simulations thermodynamiques et cinétiques indiquant que la cristallisation de YLn-phosphates et d'autres phases authigènes apparaît comme la conséquence de la dissolution de la fraction solubles de cendres / The solid-liquid interaction processes regulate the mechanisms governing the availability of trace elements in liquid phase. In this paper, these processes have been studied through the use of the Rare Earth Elements (REE) since they are excellent tracers of geochemical processes. The purpose of the first part of this work was to study the reactivity of volcanic particulates during the interaction with synthetic seawater. The results show that apart from the dissolution, which is the main process, a surface adsorption process also occurs, probably on the surface of newly formed crystals. The supposed presence of these minerals is suggested by the temporal variation of the Y/Ho ratio, by SEM observations and XRD analysis. Finally the addition of ligand species to dissolved media does not increase dissolution rate of volcanic particles but modify the YLn distribution in liquid phase. In the second part of this work, the Rare Earth study was applied to a human system. These elements were used, in fact, to investigate the effects due to the interactions between the inhaled atmospheric particulate matter and the lung fluids (BAL), in people exposed to fallout of volcanic ash. The results suggest that YLn-phosphate co-precipitation occurs in lungs as a consequence of inhalation of volcanic particles and their interactions with lung fluids. This process is confirmed by thermodynamic and kinetic simulations indicating that crystallisation of YLn-phosphates and other authigenic phases occurs as a consequence of the soluble ash fraction dissolution. The combination of YLn fractionation in bronchial fluids can represent a potential tracer of exposure to atmospheric fallout