Datos para la comparación del micromodelado en dos macizos de granitoides peninsulares

[Resumen] El trabajo es un avance de los estudios de comparación del micromodelado de dos zonas graníticas hercínicas peninsulares, una de ellas, situada en el Pirineo aragonés (macizo de Cauterets) y la otra en la Serra do Gerez (Portugal norte), sujetas ambas en el pasado a modelado glaciar. Mientras en la zona pirenaica los procesos periglaciares son intensos en la actualidad y dán lugar a una activa evolución de vertientes, en la zona galaico portuguesa, si existe periglaciarismo, este se halla enormemente atenuado tanto en intensidad como en duración a lo largo del año. Tanto el tipo de microformas encontradas como la evolución del paleomodelado glaciar en ambas zonas parece indicar que la alteración por vía química ha ejercido una mayor influencia que la alteración por vía física (gelifracción), puesto que en la zona galaico portuguesa han desaparecido casi totalmente las huellas del micromodelado glaciar mientras que en la zona pirenaica se conservan aún en su mayor parte[Resumo] Neste traballo adiántanse algúns dos resultados do estudio de comparación do micromodelado de dúas zonas graníticas do hercínico peninsular, unha delas no Pirineo Aragonés, a outra na Serra do Geres (Portugal norde) e as dúas baixo modelado glaciar no pasado. Na actualidade a zona pirenaica está suxeita á acción dun activo periglaciarismo que leva a unha rápida dinámica de vertentes, namentras que a zona galaico portuguesa, se existe ó periglaciarismo, háxase grandemente amortecido tanto en intensidade como na duración das taes condicións ao langa do ano. Unha maior influencia, na evolución do microreleve, da alteración vía química, semella vir probada, pala cuase total esnaquización das pegadas do modelado glaciar na zonación galaico portuguesa mentras no pirineo aragonés fica unha grande parte delas, senda neste caso a alteración vía física o axente que xoga o papel mais importante na evolución do microreleve Etude polinique d'un sédiment marsh á le marais de Catoira (Pontevedra

La herencia de Pangea

[Abstract] Very old palaeosurfaces have been identified and dated in several parts of the former Gondwana and Laurasia. In Australia the separation from Antarctica was complete by the end of the Eocene so that any surface of earliest Tertiary and certainly of Mesozoic age can be regarded as Gondwanan. Similarly, in the Northern Hemisphere, Laurasia existed from the end ofthe Carboniferous to the Jurassic so that any landscape elements older than]urassic can be regarded as Laurasian.The ages of these ancient surfaces have been determined in various ways and with various degrees ofconfidence, but correlative deposits associated with the widespread Early Cretaceous marine transgression , and the relationship of land surfaces to Cretaceous shorelines and Early Tertiary volcanic extrusions, or regolithic veneers have proved especially useful. Faulting of known age has also_been used though it tends to give dates that are too young ,for the dislocated surfaces. Many exhumed surfaces have been preserved by burial, but epigene-etch features like those ofthe Gawler Ranges, Hamersley Ranges and the Arnhemland Massif (Kakadu) have stood as uplands throughout the Cainozoic with little change. The same is true of the remnants of planation surfaces of the Iberian elements ofthe Hesperian Massif. Epigene-etch surfaces ofMesozoic age are also reported from southern and West Africa, from southern India and from the Guyana Craton ofSouth America. In addition, epigene-etch features, as well as exhumed features ofvarious ages, are, increasingly, being recognised from the Laurasian components of Pangaea, for instance in the Linares-Ubeda region in the south of Iberian Peninsula, so that it is possible to refer to the Pangaean inheritance. These survival can in sorne measure be explained in terms oftheir being uplands, but obviously the conventional models of landscape evolution need to be reconsidered

Detection, quantification, and characterization of polystyrene microplastics and adsorbed bisphenol A contaminant using electroanalytical techniques

The potential applications of electroanalytical techniques for the quantification and size characterization of nonelectroactive polystyrene microplastics is reported, in addition to characterizing the kinetics of adsorption of bisphenol A on these polystyrene microparticles. The individual adsorption events of very diluted polystyrene microparticles dispersions on glassy-carbon microelectrodes produce the blocking of the charge transfer of a mediator (ferrocene-methanol) thus decreasing the current of the recorded chronoamperogram in a stepwise manner. The magnitude of the current steps are in the order of pA values and can be related to the diameter of the plastic microparticles in the size range 0.1 to 10 µm. The frequency of the current steps in the domain time used (120 s) allows to quantify the number concentration of these microparticles in the range 0.005 to 0.500 pM. Electrochemical impedance spectroscopy confirms the adsorption of the polystyrene microplastics on carbon microelectrodes (and to a lesser extent on platinum microelectrodes) under the same experimental conditions as above. On the other hand, the adsorbed microplastics become concentrators of other pollutants found in the environment. The sensitive differential-pulse voltammetry determination of bisphenol A (linear range 0.80–15.00 µM; detection limit 0.24 µM) was used together with a simple separation procedure for studying the adsorption of bisphenol A on polystyrene microparticles. The adsorption capacity (mg of bisphenol A retained per g of the polystyrene microplastics) decreased from approximately 5.7 to 0.8 mg g−1 with increasing dosages of polystyrene microparticles from 0.2 to 1.6 g l−1. The adsorption isotherms were modeled resulting in a monolayer of bisphenol A adsorbed on the microplastics (i.e., best fitted to a Langmuir model)

Gradual Drift Detection in Process Models Using Conformance Metrics

Changes, planned or unexpected, are common during the execution of real-life processes. Detecting these changes is a must for optimizing the performance of organizations running such processes. Most of the algorithms present in the state-of-the-art focus on the detection of sudden changes, leaving aside other types of changes. In this paper, we will focus on the automatic detection of gradual drifts, a special type of change, in which the cases of two models overlap during a period of time. The proposed algorithm relies on conformance checking metrics to carry out the automatic detection of the changes, performing also a fully automatic classification of these changes into sudden or gradual. The approach has been validated with a synthetic dataset consisting of 120 logs with different distributions of changes, getting better results in terms of detection and classification accuracy, delay and change region overlapping than the main state-of-the-art algorithms

Evaluación de la meteorización de rocas graníticas en edificios históricos urbanos por medio de indices geoquímicos

Weathering involves important processes that alter the original structure, texture and chemical components of rocks and minerals. Bulk changes produced by weathering in granitic rocks have been studied by several methods, including chemical weathering indices. They are based on the assumption that some ions are more easily leached from minerals in relation to others. Such methods have also been briefly tested on building stone but not in urban environments, where fast stone weathering rates are typically observed, mainly due to interaction of minerals with several pollutants and where other specific processes, such as salt weathering, can occur. The aim of this work is to discuss the use of weathering indices in the study of weathering rates on granitic stones applied in four historical buildings of an urban area. Results suggest that some factors can cause scatter of results in the relation indices vs. exposition age in the built environment, namely previous weathering degree in rock massifs and the quarry, different orientation of façades and different exposure to urban pollutants. Indices that consider some highly mobile cations that are present in other building materials (namely Ca that is related to leaching from mortar joints) should be avoided due to the uptake of such elements by the stone pores or used to assess this some types of weathering. Moreover, the use of some indices shows more reliable results.La meteorización implica importantes procesos que alteran la estructura, textura y componentes quimicos originales de las rocas y minerales. Los cambios producidos por la meteorización en rocas graniticas han sido estudiados por varios métodos, incluyendo los índices de meteorización química. Éstos se basan en la suposición de que algunos iones son lavados de los minerales más fácilmente que otros. Tales métodos también se han probado, aunque en pocos casos, en rocas de edificios, pero no de ambientes urbanos, en donde se han observado tipicamente elevadas tasas de meteorización, principalmente por la interacción de los minerales con varios compuestos contaminantes y en dónde otros procesos específicos, tales como la erosión por sales, pueden producirse. El objetivo de este trabajo es discutir el uso de indices de meteorización en el estudio de las tasas de meteorización de rocas usadas en cuatro edificios históricos de un área urbana. Los resultados sugieren que algunos factores pueden causar la dispersión de los resultados obtenidos a través de los indices en relación al tiempo de exposición en el ambiente construido, principalmente por el grado de meteorización previo de la roca en los macizos rocosos y en la cantera, la orientación de las fachadas y la diferente exposición a compuestos contaminantes. Los índices que consideran algunos cationes altamente móviles que están presentes en otros materiales de construcción (principalmente el Ca que se relaciona con la meteorización de morteros en las juntas) deben ser evitados debido a que penetran en los poros de las rocas de edificios o deben ser usados para evaluar algunos tipos de meteorización. Por otra parte, el uso de algunos índices muestra resultados más fiables.Este trabalho insere-se nas atividades do Projeto Lab2PT- Laboratório de Paisagens, Património e Território - AUR/04509 que tem o apoio financeiro da FCT/MCTES através de fundos nacionais (PIDDAC) e o cofinanciamento do Fundo Europeu de Desenvolvimento Regional (FEDER), refª POCI-01-0145-FEDER-007528, no âmbito do novo acordo de parceria PT2020 através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI).info:eu-repo/semantics/publishedVersio