Recent tectonic and morphostructural evolution of Byers Peninsula (Antarctica): insight into the development of the South Shetland Islands and Bransfield Basin

Byers Peninsula forms the western extremity of the Livingston Island (Antarctica) in the continental South Shetland Block. This tectonic block is bounded by the South Shetland Trench to the north, the Bransfield back-arc basin to the south, and extends to the South Scotia Ridge on the east. Westwards it is connected to the Antarctic Plate by a broad deformation zone located at the southern end of the Hero Fracture Zone. In Byers Peninsula we analyzed more than 1,200 lineaments, and 359 fault planes from 16 sites, both in sedimentary and intrusive igneous rocks. Statistical analysis of lineaments and mesoscopic fractures, with a length varying between 31 and 1,555 m, shows a NW-SE maximum trend, with two NE-SW and ENE-WSW secondary maximums. Fault orientation analysis shows similar trends suggesting that most of the lineaments correspond to fractures. Due to the absence of striated faults and the lack of kinematic evidence on the regime in most of the analyzed faults we have used the Search Grid paleostress determination method. The results obtained allow us to improve and complete the data on the recent evolution of the South Shetland Block. In this complex geodynamic setting, Byers Peninsula has been subjected to NNW-SSE to NNE-SSW extension related to Bransfield Basin opening and NE-SW and NW-SE local compressions respectively associated to Scotia-Antarctic plate convergence and the South Shetland Trench subduction.La Península Byers se localiza en el extremo occidental de la Isla Livingston (Antártida) que pertenece al bloque continental de las Shetland del Sur. Este bloque tectónico está limitado al norte por la Fosa de las Shetland del Sur, al sur por la cuenca de trasarco de Bransfield, y hacia el este se extiende por la Dorsal Sur de Scotia. Hacia el oeste conecta con la placa Antártica a través de una amplia zona de deformación localizada en la prolongación meridional de la Zona de Fractura Hero. En este trabajo se han analizado conjuntamente más de 1.200 lineamientos, así como 359 planos de fallas en 16 estaciones en rocas sedimentarias e ígneas de la Península Byers. El análisis estadístico de los lineamientos y las fracturas a escala mesoscópica, con una longitud que oscila entre 31 y 1.555 m, muestran una orientación máxima NO-SE, con dos máximos secundarios de dirección NE-SO y ENE-OSO. El análisis de las fracturas muestra orientaciones similares que sugieren que gran parte de estos lineamientos están relacionados con fracturas. La ausencia de indicadores cinemáticos de calidad en la mayor parte de las fracturas sólo nos ha permitido aplicar el método de Redes de Búsqueda para el cálculo de paleoesfuerzos. Los resultados obtenidos son compatibles con los obtenidos en otros sectores del Bloque de las Shetland del Sur. En este complejo contexto geodinámico, la Península Byers ha estado sometida a extensión NNW-SSE/ NNE-SSW ligada a la apertura de la cuenca de Bransfield, así como a compresión local NE-SO y NO-SE asociada respectivamente a la convergencia entre las placas Scotia y Antártica, y a la subducción en la Fosa de las Shetland del Sur

Ríos y ciudades: análisis de los usos del suelo en el espacio fluvial de las áreas urbanas españolas

En el presente artículo se analizan los usos del suelo existentes en las zonas de inundación frecuente de las áreas urbanas españolas. Estos se clasifican en grupos, distinguiendo las coberturas naturales de las antrópicas y, dentro de ellas, los usos compatibles y no compatibles con las inundaciones fluviales. El análisis realizado determina y compara el reparto de usos en el espacio fluvial y en las áreas urbanas, estudiando la ocupación de los ríos según la región biogeográfica a la que pertenecen y su temporalidad de flujo. Los resultados muestran que (1) los ríos en las ciudades son potenciales infraestructuras verdes donde abundan las coberturas naturales, espacios ajardinados, agrícolas y ganaderos; (2) se ha ocupado casi tres cuartas partes del espacio fluvial en las áreas urbanas; y (3) la presión antrópica es mayor en los ríos de la región mediterránea y, sobre todo, en los cursos de caudal intermitente. Este trabajo, pone de manifiesto la falta de una ordenación territorial coherente con los espacios fluviales y puede ser útil para contribuir a una sistematización metodológica que permita ampliar y contrastar el conocimiento de esta línea científica.This article analyses the existing land-uses in the areas of frequent flooding in Spanish urban areas. These are classified into groups, distinguishing between natural and anthropogenic coverages and, within these, uses that are compatible and not compatible with flooding. The analysis carried out decides and compares the distribution of uses within the fluvial space and the urban areas, studying the occupation of the rivers according to the biogeographical region to which they belong and its temporal flow. The results show that (1) rivers in the cities are potentially green infrastructures where there are plenty of natural coverings, garden areas, agriculture and livestock farming; (2) it has taken up almost three quarters of the fluvial space in urban areas; and (3) the anthropic pressure is greater in the rivers of the Mediterranean region, especially, in the intermittent flow courses. This article, highlights the lack of a coherent spatial planning with the fluvial spaces which can be useful to contribute to a methodological systematization, allowing to expand and contrast the knowledge of this scientific line

Rascal: From Algebraic Specification to Meta-Programming

Algebraic specification has a long tradition in bridging the gap between specification and programming by making specifications executable. Building on extensive experience in designing, implementing and using specification formalisms that are based on algebraic specification and term rewriting (namely Asf and Asf+Sdf), we are now focusing on using the best concepts from algebraic specification and integrating these into a new programming language: Rascal. This language is easy to learn by non-experts but is also scalable to very large meta-programming applications. We explain the algebraic roots of Rascal and its main application areas: software analysis, software transformation, and design and implementation of domain-specific languages. Some example applications in the domain of Model-Driven Engineering (MDE) are described to illustrate this.Comment: In Proceedings AMMSE 2011, arXiv:1106.596

Authentication of tequilas using pattern recognition and supervised classification

[Abstract] Sales of reputed, Mexican tequila grown substantially in last years and, therefore, counterfeiting is increasing steadily. Hence, methodologies intended to characterize and authenticate commercial beverages are a real need. They require a combination of analytical characterization and chemometric tools. This work reports concisely on the former and focus on the chemometric tools employed so far in connection with them. Further, a practical case study presents the classification capabilities of nine supervised classification methods to differentiate white, rested, aged and extra-aged tequilas. The largest set of certified tequilas employed so far was considered. In general, non linear methods performed best than linear ones (accuracy higher than 94% in both training and validation). The case study demonstrates that it is possible to develop fast, cheap, easy to implement and reliable analytical methodologies to authenticate and classify samples of tequilas.Xunta de Galicia; GRC2013-047Ministerio de Industria, Energía y Competitividad; FJCI-2015-2607

What is an urban river? A methodological approach for its delimitation in Spain

A pesar de que las publicaciones en torno a ríos urbanos son abundantes, no hay investigaciones que se centren en su definición y, por esa misma razón, tampoco procedimientos oficiales para delimitarlos. El presente trabajo tiene como objetivos (1) definir qué es un río urbano y (2) delimitar los tramos fluviales urbanos para el territorio español. Las principales motivaciones para realizar este estudio son de diversa índole. En primer lugar, el interés científico-geográfico que entraña analizar una cuestión compleja como esta; en segundo lugar, la evidencia de que existen conflictos entre ayuntamientos y administraciones hidráulicas por la asunción de competencias y; por último, la idea, cada vez más extendida entre la comunidad científica, de promover una gestión diferenciada del espacio fluvial urbano y rural. A través del análisis del escenario de planificación y gestión de los cursos de agua en las zonas urbanas y la reflexión en torno al concepto “río urbano”, se concluye que un tramo de un río debe considerarse como urbano cuando se encuentren usos urbanos en su Dominio Público Hidráulico o sus Zonas de Protección y/o cuando dicho tramo se encuentre inmerso en una matriz urbana. En base a esta definición, se elabora una metodología de delimitación a escala nacional que indica que un 6 % de la red fluvial del territorio español tiene carácter urbano

Numerical sedimentation particle-size analysis using the Discrete Element Method

Sedimentation tests are widely used to determine the particle size distribution of a granular sample. In this work, the Discrete Element Method interacts with the simulation of flow using the well known one-way- coupling method, a computationally affordable approach for the time-consuming numerical simulation of the hydrometer, buoyancy and pipette sedimentation tests. These tests are used in the laboratory to determine the particle-size distribution of fine-grained aggregates. Five samples with different particle-size distributions are modeled by about six million rigid spheres pro- jected on two-dimensions, with diameters ranging from 2.5 × 10−6 m to 70 × 10−6 m, forming a water sus- pension in a sedimentation cylinder. DEM simulates the particle s movement considering laminar flow in- teractions of buoyant, drag and lubrication forces. The simulation provides the temporal/spatial distributions of densities and concentrations of the suspension. The numerical simulations cannot replace the laboratory tests since they need the final granulometry as initial data, but, as the results show, these simulations can identify the strong and weak points of each method and eventually recommend useful variations and draw conclusions on their validity, aspects very difficult to achieve in the laboratory.R. Bravo and J.L. Perez-Aparicio were partially supported by the project MICIIN #BIA-2012-32918. The second researcher used the grant GV BEST/2014/232 for the completion of this work. J. Jaime Gomez-Hernandez acknowledges the financial aid from project MINECO CGL2011-23295.Bravo, R.; Pérez Aparicio, JL.; Gómez Hernández, JJ. (2015). Numerical sedimentation particle-size analysis using the Discrete Element Method. Advances in Water Resources. 86:58-72. https://doi.org/10.1016/j.advwatres.2015.09.024S58728

New insights into microwave pyrolysis of biomass: preparation of carbon-based products from pecan nutshells and their application in wastewater treatment

Microwave pyrolysis of pecan nutshell (Carya illinoinensis) biomass was used to produce carbon-based solid products with potential application in contaminated water treatment. A range of analytical techniques were applied to characterize the intermediate products of microwave pyrolysis in order to monitor the physio-chemical effects of the interacting energy on the biomass. The performance of the carbon-based products was tested through evaluation of lead ion removal capacity from solution. Further analyses demonstrated that ion-exchange by calcium ions on the material surface was the main mechanism involved in lead removal. Calcium compound development was directly correlated to the interaction of the electromagnetic waves with the biomass. Through monitoring the physio-chemical effects of biomass-microwave interactions during microwave pyrolysis, we have shown for the first time that the intermediate products differ from those of conventional pyrolysis. We hypothesise that selective heating leads to the (hemi)cellulosic and lignin degradation processes occurring simultaneously, whereas they are largely sequential in conventional pyrolysis. This work provides optimization parameters essential for the large scale design of microwave processes for this application as well as an understanding of how the operating parameters impact on functionality of the resulting carbon-based materials

A recovery-explicit error estimator in energy norm for linear elasticity

[EN] Significant research effort has been devoted to produce one-sided error estimates for Finite Element Analyses, in particular to provide upper bounds of the actual error. Typically, this has been achieved using residual-type estimates. One of the most popular and simpler (in terms of implementation) techniques used in commercial codes is the recovery-based error estimator. This technique produces accurate estimations of the exact error but is not designed to naturally produce upper bounds of the error in energy norm. Some attempts to remedy this situation provide bounds depending on unknown constants. Here, a new step towards obtaining error bounds from the recovery-based estimates is proposed. The idea is (1) to use a locally equilibrated recovery technique to obtain an accurate estimation of the exact error, (2) to add an explicit-type error bound of the lack of equilibrium of the recovered stresses in order to guarantee a bound of the actual error and (3) to efficiently and accurately evaluate the constants appearing in the bounding expressions, thus providing asymptotic bounds. The numerical tests with h-adaptive refinement process show that the bounding property holds even for coarse meshes, providing upper bounds in practical applications.The authors also thank the support of the Framework Programme 7 Initial Training Network Funding under grant number 289361 "Integrating Numerical Simulation and Geometric Design Technology".Nadal Soriano, E.; Díez, P.; Ródenas, J.; Tur Valiente, M.; Fuenmayor Fernández, FJ. (2015). A recovery-explicit error estimator in energy norm for linear elasticity. Computer Methods in Applied Mechanics and Engineering. 287:172-190. https://doi.org/10.1016/j.cma.2015.01.013S17219028

Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum

We report a first measurement for ultra-high energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the `ankle' at $\lg(E/{\rm eV})=18.5-19.0$ differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass $A > 4$. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report Numbe

Microorganisms and spatial distribution of the sinkholes of the Yucatan Peninsula, underestimated biotechnological potential?

Investigación basada en el potencial bio-tecnológico de las micro-especies que habitan los cenotes de la Península de YucatánAbstract Objective: To detect the spatial distribution of the sinkholes of the Peninsula of Yucatan (SPY) and identify those cenotes where microorganisms have been registered. Methods: The geographic coordinates of the SPYs were obtained from various databases, as well as from scientific publications relating to the terminology ‘sinkholes’, ‘karst systems’ and ‘cenotes’. All coordinates were transformed into the Universal Transverse Mercator reference system (UTM) with datum WGS84. An infrared composite image was created with 432 RGB bands from the Landsat 8 satellite. The points with the location of the cenotes were imported into the Software TerrSet. Results: Total 1026 coordinates of sinkholes were recorded in the Yucatan Peninsula. In 18 sinkholes (<2%), microorganisms have been recovered and identified in various taxonomic levels, and only 6 sinkholes (<0.6%) has their biotechnological potential been evaluated. Conclusions: The microorganisms that inhabit the sinkholes of the Yucatan Peninsula are a reservoir with practically unexplored biotechnological potential.CONACY