Crack arrest through branching at curved weak interfaces: an experimental and numerical study

The phenomenon of arrest of an unstably-growing crack due to a curved weak interface is investigated. The weak interface can produce the deviation of the crack path, trapping the crack at the interface, leading to stable crack growth for certain interface geometries. This idea could be used as a technical solution for a new type of crack arrester, with a negligible impact on the global stiffness, strength and weight of the structure. In order to exploit this concept, an experimental campaign based on photo-elasticity and digital image correlation is carried out, showing the capability of curved weak interfaces to arrest cracks. The experiment is repeated for several geometrical configurations through the modification of the interface curvature radii. The phenomenon of crack deviation and subsequent arrest at the interface is also investigated with the assistance of a computational model based on the finite element method. The computational predictions provide the rationale for the interpretation of the experimental observations, and distinguish between the different behaviour of concave and convex interfaces. Consequently, as is shown in the present study, the curved interface concept fosters new routes for the attainment of structures with enhanced fracture resistance capacities, which are of paramount importance for materials and components used in extreme conditions.Comment: 19 pages, 13 figure

Análisis multivariante de los horizontes orgánico-minerales de los suelos del Parque Natural de Sierra Mágina (Jaén)

Soils are described normally using a great number of properties (variables). This generates a great quantity of data not easily understandable in a direct way. Consequently, multivariate analysis is necessary to support and confirm impressions and interpretations of investigations in field and laboratory. In the present work we quantify, through multivariate analysis, the relative influence of the different factors of soil formation that act on the soil system. We have studied 203 organo-mineral horizons, sampled to a depth between 0 and 25 cm of soils in the Sierra Mágina natural park (Jaén, Spain). The studied soils are from calcareous rocks. Five factors were found to be significant and showed that the organic carbon accumulation, decarbonatation and the argillization/rubefacction, as internal variables, and the hill slope, as external variable, they are those which explain a greater percentage of the natural variability of the soil system

U(2)-like Flavor Symmetries and Approximate Bimaximal Neutrino Mixing

Models involving a U(2) flavor symmetry, or any of a number of its non-Abelian discrete subgroups, can explain the observed hierarchy of charged fermion masses and CKM angles. It is known that a large neutrino mixing angle connecting second and third generation fields may arise via the seesaw mechanism in these models, without a fine tuning of parameters. Here we show that it is possible to obtain approximate bimaximal mixing in a class of models with U(2)-like Yukawa textures. We find a minimal form for Dirac and Majorana neutrino mass matrices that leads to two large mixing angles, and show that our result can quantitatively explain atmospheric neutrino oscillations while accommodating the favored, large angle MSW solution to the solar neutrino problem. We demonstrate that these textures can arise in models by presenting a number of explicit examples.Comment: 20 pages RevTex4, 2 figure

The blaSHV-5 gene is encoded in a compound transposon duplicated in tandem in Enterobacter cloacae

AbstractThe presence of blaSHV-5 is described in a compound transposon, duplicated in tandem and flanked by IS26 copies on a 70-kb conjugative plasmid (pHNM1), in an Enterobacter cloacae strain associated with a nosocomial outbreak that occurred in Mexico

Review of the Commission Decision 2010/477/EU concerning MSFD criteria for assessing Good Environmental Status, Descriptor 7

This report represents the result of the scientific and technical review of Commission Decision 2010/477/EU in relation to Descriptor 7. The review has been carried out by the EC JRC together with experts nominated by EU Member States, and has considered contributions from the GES Working Group in accordance with the roadmap set out in the MSFD implementation strategy (agreed on at the 11th CIS MSCG meeting). The report is one of a series of reports (review manuals) including Descriptor 1, 2, 5, 7, 8, 9, 10 that conclude phase 1 of the review process and, as agreed within the MSFD Common Implementation Strategy, are the basis for review phase 2, towards an eventual revision of the Commission Decision 2010/477/EU. The report presents the state of the technical discussions as of 30 April 2015 (document version 7.0: ComDecRev_D7_V7.0_FINAL.docx), as some discussions are ongoing, it does not contain agreed conclusions on all issues. The document does not represent an official, formal position of any of the Member States and the views expressed in the document are not to be taken as representing the views of the European Commission.JRC.H.1-Water Resource

Maximal Neutrino Mixing from a Minimal Flavor Symmetry

We study a number of models, based on a non-Abelian discrete group, that successfully reproduce the simple and predictive Yukawa textures usually associated with U(2) theories of flavor. These models allow for solutions to the solar and atmospheric neutrino problems that do not require altering successful predictions for the charged fermions or introducing sterile neutrinos. Although Yukawa matrices are hierarchical in the models we consider, the mixing between second- and third-generation neutrinos is naturally large. We first present a quantitative analysis of a minimal model proposed in earlier work, consisting of a global fit to fermion masses and mixing angles, including the most important renormalization group effects. We then propose two new variant models: The first reproduces all important features of the SU(5)xU(2) unified theory with neither SU(5) nor U(2). The second demonstrates that discrete subgroups of SU(2) can be used in constructing viable supersymmetric theories of flavor without scalar universality even though SU(2) by itself cannot.Comment: 34 pages LaTeX, 1 eps figure, minor revisions and references adde

Four-dimensional distribution of the 2010 Eyjafjallajökull volcanic cloud over Europe observed by EARLINET

© Author(s) 2013. This work is distributed under the Creative Commons Attribution 3.0 License.The eruption of the Icelandic volcano Eyjafjallaj ökull in April-May 2010 represents a "natural experiment" to study the impact of volcanic emissions on a continental scale. For the first time, quantitative data about the presence, altitude, and layering of the volcanic cloud, in conjunction with optical information, are available for most parts of Europe derived from the observations by the European Aerosol Research Lidar NETwork (EARLINET). Based on multi-wavelength Raman lidar systems, EARLINET is the only instrument worldwide that is able to provide dense time series of high-quality optical data to be used for aerosol typing and for the retrieval of particle microphysical properties as a function of altitude. In this work we show the four-dimensional (4-D) distribution of the Eyjafjallajökull volcanic cloud in the troposphere over Europe as observed by EARLINET during the entire volcanic event (15 April-26 May 2010). All optical properties directly measured (backscatter, extinction, and particle linear depolarization ratio) are stored in the EARLINET database available at www.earlinet.org. A specific relational database providing the volcanic mask over Europe, realized ad hoc for this specific event, has been developed and is available on request at www.earlinet.org. During the first days after the eruption, volcanic particles were detected over Central Europe within a wide range of altitudes, from the upper troposphere down to the local planetary boundary layer (PBL). After 19 April 2010, volcanic particles were detected over southern and south-eastern Europe. During the first half of May (5-15 May), material emitted by the Eyjafjallajökull volcano was detected over Spain and Portugal and then over the Mediterranean and the Balkans. The last observations of the event were recorded until 25 May in Central Europe and in the Eastern Mediterranean area. The 4-D distribution of volcanic aerosol layering and optical properties on European scale reported here provides an unprecedented data set for evaluating satellite data and aerosol dispersion models for this kind of volcanic events.Peer reviewe

CULTIVO DE CEPAS DE LEVADURAS DE SUELO TRUMAO EN «VINAZA»

30 cepas de levaduras aisladas desde un suelo trumao (Hapludans) usado como pradera en rotación, se cultivaron individualmente (100 µl = a 102 ufc de levaduras/mL) en matraces con 50 mL de «vinaza», estos fueron incubados en un agitador orbital a 150 rpm, 23 °C por 5 días, luego de la incubación el contenido de cada matraz se centrifugo a 3.500 rpm por 20 min., a los pellet obtenidos se les determino: el peso seco (PS); fosforo total (FT) por digestión ácida y posterior lectura a 400 nm; proteínas totales (PT) por colorimetría Biuret a 595 nm y lípidos totales (LT) mediante el método colorimétrico de la sulfo-fosfo vainillina a 520 nm. Las 30 cepas de levaduras crecieron en la vinaza. El mayor PS lo registro la cepa 25 (331 g de levadura L-1 de «vinaza»). FT lo registro la cepa 28 (4,8 mg g-1 de levadura seca). PT lo registro la cepa 24 (25,90 mg g-1 de levadura seca) y LT lo registro la cepa 18 (287,4 mg g-1 de levadura seca)

The Interplay Between GUT and Flavour Symmetries in a Pati-Salam x S4 Model

Both Grand Unified symmetries and discrete flavour symmetries are appealing ways to describe apparent structures in the gauge and flavour sectors of the Standard Model. Both symmetries put constraints on the high energy behaviour of the theory. This can give rise to unexpected interplay when building models that possess both symmetries. We investigate on the possibility to combine a Pati-Salam model with the discrete flavour symmetry $S_4$ that gives rise to quark-lepton complementarity. Under appropriate assumptions at the GUT scale, the model reproduces fermion masses and mixings both in the quark and in the lepton sectors. We show that in particular the Higgs sector and the running Yukawa couplings are strongly affected by the combined constraints of the Grand Unified and family symmetries. This in turn reduces the phenomenologically viable parameter space, with high energy mass scales confined to a small region and some parameters in the neutrino sector slightly unnatural. In the allowed regions, we can reproduce the quark masses and the CKM matrix. In the lepton sector, we reproduce the charged lepton masses, including bottom-tau unification and the Georgi-Jarlskog relation as well as the two known angles of the PMNS matrix. The neutrino mass spectrum can present a normal or an inverse hierarchy, and only allowing the neutrino parameters to spread into a range of values between $\lambda^{-2}$ and $\lambda^2$, with $\lambda\simeq0.2$. Finally, our model suggests that the reactor mixing angle is close to its current experimental bound.Comment: 62 pages, 4 figures; references added, version accepted for publication in JHE

Situación nutricional de pacientes adultos que concurren a los centros de salud del Gran San Juan.

Se realizó un diagnóstico de la situación alimentario-nutricional de la población adulta que asiste a los 21 centros sanitarios pertenecientes al Gran San Juan, incluyéndose pacientes de 19 a 69 años de edad. El objetivo del trabajo ha sido valorar el estado nutricional de la población adulta, analizar los hábitos alimentarios, determinar la prevalencia de obesidad abdominal, identificar la frecuencia y  tipo de actividad física, determinar el consumo de tabaco, formular una base de datos apropiada para articular entre Ministerios y otros sectores de la salud a fin de determinar estrategias de educación alimentario-nutricional que tiendan a disminuir el desarrollo de enfermedades asociadas a trastornos nutricionales, para mejorar la calidad de vida de la población