538 research outputs found
El sistema de integración centroamericano (SICA) y la Unión Europea (UE) ante el acuerdo de asociación (ADA): una visión desde Europa
Morfología macroscópica de alteración de la piedra del conjunto catedralicio de Granada/España
Los principales factores de alteración que actúan en el conjunto catedralicio de Granada son, uno natural de origen térmico, dadas las bajas temperaturas que se alcanzan en invierno, y las grandes oscilaciones térmicas que se registran durante gran parte del año, y los de origen antropogénico, fundamentalmente los de mal uso de elementos de sujeción metálicos oxidables y los de contaminación atmosférica debida a productos de combustión. De esta forma, los mecanismos de alteración primordiales son los de heladicidad por la expansión producida por la congelación del agua retenida en los poros y microgrietas, sobre todo en los elementos arquitectónicos de mayor superficie de exposición y en su orientación umbría. Los indicadores a que ello conduce son las fisuras y fragmentaciones. Así, muchos elementos de piedra de Santa Pudia de la crestería de la Capilla Real se han perdido y los que quedan se encuentran muy degradados. La piedra de Sierra Elvira de las cornisas, más compacta, también se ve afectada por este mecanismo, iniciado por las microgrietas provocadas por dilataciones diferenciales debidas a oscilaciones térmicas, que facilitaron el acceso al agua. La expansión de hierros al oxidarse ha provocado la fracturación y fisuración de gran número de elementos ornamentales como bolas, pináculos, etc, que han obligado al desmontaje de muchos de ellos por el riesgo de caída, sobre todo en las terrazas superiores del monumento.
Los mecanismos de disolución, ciclos de cristalización y acción química han conducido a la pérdida abundante de materia, tanto en forma de arenizaciones, sobre todo en las zonas de mayor humedad, como de formación de huecos (picados, alveolizaciones, estriados), en aquellas zonas más expuesta al viento. Esto afecta de forma generalizada a las zonas bajas en todo el perímetro del edificio, excepto en gran parte de la fachada principal, así como en todos los antepechos y en las superficies situadas debajo de las cornisas. Estas arenizaciones se ven favorecidas cuando existen placas biológicas o depósitos de inquemados, siendo estos últimos de mayor abundancia en las superficies más cercanas a la Gran Vía y en su orientación hacia ésta. Por último, y sobre todo por su repercusión estética, es necesario mencionar los abundantes depósitos de guano de palomino, cuya mayor presencia se da en la fachada principal.The main factors of deterioration that affect the Cathedral Whole of Granada are one of natural thermic origin due to the low temperatures during the winters and the higher thermic oscillations and those of anthropogenical origin: fundamentally the oxidation of metallic elements and atmospheric pollution due to burnt products. For this reason, the more important deterioration mechanisms arethe freezing ones due to the expansión produced in the v^ater retained inside the pores and microcracks, fundamentally in the architectonic elements with high expositional surface and in their shady orientation; the main indicators produced are fissuring and spalling. In this way, a lot of elements of Santa Pudia stone located in the Royal Chapel crenellations have disappeared and the rest are very deteriorated. The more compact Sierra Elvira stone used on the upper zone of the cornices has also been affected by the freezing mechanism, which starts with the microcracks produced by differential dilatations due to the thermic oscillations which made the water access easy. The iron corrosión and later expansión of the oxidation products has provoked the cracking and fissuring of many ornamental elements like balls, pinnacles, etc, and this situation has obliged their dismantling on the upper zones due to the danger to the public.
The mechanisms of dissotution, crystallization cycles and Chemical action have led to abundant material loosening in the form of grain disgregation overcoats on the higher humidity zones, and formation of hollows (pitting, alveolar erosión, striations) in the zones more exposed to the winds. This situation is generalized in the lower zones of the monument, except on the main fagade, and in the parapets and lower zones of the cornices. The grain disgregations are more important when biological crusts or unburned deposits exist, the latter being of major abundance on the surfaces near the Gran Vía and in its orientation. It is necessary to mention the pigeon dung deposits, very important in the main fagade, with greater stetical repercussion
On the Schrödinger Equation for Time-Dependent Hamiltonians with a Constant Form Domain
We study two seminal approaches, developed by B. Simon and J. Kisynski, to the wellposedness
of the Schrödinger equation with a time-dependent Hamiltonian. In both cases, the
Hamiltonian is assumed to be semibounded from below and to have a constant form domain, but a
possibly non-constant operator domain. The problem is addressed in the abstract setting, without
assuming any specific functional expression for the Hamiltonian. The connection between the two
approaches is the relation between sesquilinear forms and the bounded linear operators representing
them. We provide a characterisation of the continuity and differentiability properties of form-valued
and operator-valued functions, which enables an extensive comparison between the two approaches
and their technical assumptions.A.B. and J.M.P.-P. acknowledge support provided by the “Ministerio de Ciencia e Innovación”
Research Project PID2020-117477GB-I00, by the QUITEMAD Project P2018/TCS-4342 funded
by Madrid Government (Comunidad de Madrid-Spain) and by the Madrid Government (Comunidad
de Madrid-Spain) under the Multiannual Agreement with UC3M in the line of “Research Funds for
Beatriz Galindo Fellowships” (C&QIG-BG-CM-UC3M), and in the context of the V PRICIT (Regional
Programme of Research and Technological Innovation). A.B. acknowledges financial support by
“Universidad Carlos III de Madrid” through Ph.D. Program Grant PIPF UC3M 01-1819 and through
its mobility grant in 2020. D.L. was partially supported by “Istituto Nazionale di Fisica Nucleare”
(INFN) through the project “QUANTUM” and the Italian National Group of Mathematical Physics
(GNFM-INdAM)
Upper Miocene deposits at the southern margin of the Guadalquivir Foreland Basin (central Betic Cordillera, S. Spain). Implications for the closure timing of the Atlantic-Mediterranean connections
Acknowledgments
We acknowledge the comments and suggestions made by two re- viewers, which have improved the quality of the paper. We thank Jodi Eckart for her help correcting the English text. Dr Sánchez-Almazo helped with the SEM analyses and photographs of foraminifers. This paper has been supported by the research project PGC2018–099391-B- 100 of the Spanish Ministerio de Ciencia, Innovación y Competitividad, and the research group RMN190 of the Junta de Andalucía.Mixed siliciclastic-carbonate deposits accumulated in several satellite sub-basins at the southern margin of the Guadalquivir Basin, the foreland basin of the Betic Cordillera (S. Spain). The prevailing coarse-grained sediments and deposition in shallow-water settings make it difficult to establish the precise age of the complete successions. For this reason, in previous studies, these deposits were attributed to the late Tortonian, although a Messinian age was not totally ruled out. The age of the upper Miocene deposits in the central part of the Guadalquivir Basin is here re-evaluated based on the analysis of several sections distributed in different areas: Antequera, Iznájar-Cuevas de San Marcos, Teba, and Bobadilla Estación. According to planktonic foraminifer and nannoplankton assemblages, the marine sedimentary infill of this sector of the southern margin of the Guadalquivir Basin is late Tortonian-early Messinian (late Miocene) in age. The occurrence of marine deposits characterized by the dominance of Globorotalia miotumida group, dextrally-coiled G. scitula, and the presence of G. margaritae, Globigerina multiloba, Discoaster quinqueramus, Amaurolithus primus, A. amplificus, and Reticulofenestra rotaria at the northern end of the Guadalhorce Corridor, the last active gateway in the Betic Cordillera connecting the Atlantic and the Mediterranean, indicates that it remained open until the early Messinian.Research project PGC2018–099391-B- 100 of the Spanish Ministerio de Ciencia, Innovación y CompetitividadResearch group RMN190 of the Junta de Andalucí
Mixed carbonate-siliciclastic contourite drift deposits associated with the entrance of an Atlantic-Mediterranean corridor (late Miocene, southwest Spain)
Carbonate contourite drifts are poorly documented in the onshore record because of the difficulty of implementing
diagnostic criteria for their recognition. Accordingly, little is known about the relative position of carbonate
drifts with respect to ancient carbonate platforms, seaways and shallow passages within the context of
palaeoceanography. This study presents a fossil example of mixed carbonate-siliciclastic drift cropping out in a
quarry in Osuna (Sevilla province, southern Spain) at the northern end of the Guadalhorce Corridor, a Miocene
strait connecting the Mediterranean Sea and the Atlantic Ocean in the Betic Cordillera. Based on the facies and
sedimentary structures, the studied succession is divided into three units: 1) the lower unit, Unit 1, is a 33-m
thick succession of large carbonate bodieswithmega cross-stratification pointing to the southeast and secondarily
to the northwest interpreted as a contourite drift; 2) the intermediate Unit 2 is a 0.5–2-m thick terrigenous
conglomerate body eroding the top of Unit 1; and 3) the uppermost Unit 3 consists of a 6-m thick siliciclasticdominated
succession with herringbone cross-stratification and a dominant direction of the structures to the
northwest interpreted as tidal deposits. The large-scale sediment bodies with mega cross-beds, the presence of
reactivation surfaces with grain-size changes, and the unidirectionality of the structures were diagnostic for
the recognition of Unit 1 as drift deposits. The dominant sedimentary structures pointing to the southeast in
the drift were generated by Atlantic inflow into the Mediterranean. This challenges the classical “siphon”
model for the Atlantic-Mediterranean water-mass circulation pattern for this age. The conglomerates of Unit 2
evidence regional uplift of the southernmargin of the Guadalquivir Basin that promoted a change in the depositional
mode from a bottom-current dominated (Unit 1) to a tide-dominated environment (Unit 3) after the closure
of the Guadalhorce Corridor in the Messinian.Juan de la Cierva Project (Ministerio de Ciencia, Innovacion y Universidades) JC2019042375-I
project SECAMARA PGC2018099391-B-100Junta de Andalucia
European Commission RNM-19
Polonia y España ante los retos de la cooperación en la Europa unida del siglo XXI: Introducción histórica
España ante la culminación de la ampliación de la Unión Europea al comenzar el siglo XXI: los casos de Bulgaria, Rumanía, Croacia y Turquía
Los exiliados del Este: El Movimiento Europeo y el proceso comunitario a comienzos de los años cincuenta
This article is aimed at providing an analysis of the position adopted in the
early nineteen fifties by those members of the European movement who had
been exiled from their native countries in the Eastern side of the Continent,
namely, their position as to the beginning of the integration process and the unification
of Germany. By examining the European Movement documentation preserved
in the European Comunity Archives of Florence, a comparison can be
established between the European Movement’s political discourse ans that of the
Eastern exiled members, thus allowing for an assessement of their concomitants
ans differences at the outbreak of the Cold War
- …