343 research outputs found

    Development of a novel fcc structure for an amorphous-nanocrystalline Ti-33Nb-4Mn (at.%) ternary alloy

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    [EN] In this work, a novel amorphous-nanocrystalline titanium-niobium-manganese solid solution ternary alloy with a Ti-33Nb-4Mn (at.%) nominal composition was developed by a High-Energy Mechanical Alloying. Nb and Mn were added to the elemental Ti as a beta-phase (bcc) stabilizer and an amorphization promoter, respectively. The system evolved from the elemental Ti, Nb and Mn raw materials to a body centred cubic (bcc) TiNbMn alloy and, finally, to the formation of an original and stable face centred cubic (fcc) nanocrystalline TiNbMn alloy, not reported until now, at short milling time (20 h). This alloy remains invariant until 120 h. In turn, the partial amorphization of the system occurs and increases until at intermediate milling time (80 h). The production of both original fcc and the amorphous TiNbMn alloy may be beneficial for reducing the Young's modulus and improving the mechanical strength pursued for the Ti alloy. The optimal milling time respect to the amorphization, nanocrystalline size and Fe mount from milling media was 60 h and 80 h (TiNbMn60h and TiNbMn80h), with > 50 wt% of an amorphous phase and a crystalline domain size of approximately 5 nm.This work was supported under postdoctoral grant no. 3150060, which is financed by the FONDECYT fund (Government of Chile).Chicardi, E.; GarcĂ­a-Garrido, C.; SayaguĂŠs, M.; Torres, Y.; AmigĂł, V.; Aguilar, C. (2018). Development of a novel fcc structure for an amorphous-nanocrystalline Ti-33Nb-4Mn (at.%) ternary alloy. Materials Characterization. 135:46-56. https://doi.org/10.1016/j.matchar.2017.11.021S465613

    STANDARDIZED CATCH RATES FOR MEDITERRANEAN SWORDFISH (XIPHIAS GLADIUS LINNAEUS, 1758) FROM THE SPANISH LONGLINE FISHERY. 1988-2018

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    Standardized relative abundance indices for swordfish (Xiphias gladius Linnaeus, 1758) caught by the Spanish surface longline in the western Mediterranean Sea were estimated for the period 1988-2018. Standardized CPUEs in number were estimated through a General Linear Mixed Modeling (GLMM) approach under a negative binomial (NB) error distribution assumption. Standardized CPUEs in biomass were estimated through a General Linear Mixed Modeling (GLMM) approach under a log-normal error distribution assumption. The main factors in the standardization analysis were fishing area and time of the year (quarter). The standardized indices showed notable annual fluctuations without any definite trend for the period under studyEn prens

    STANDARDIZED CATCH RATES OF ALBACORE (THUNNUS ALALUNGA BONNATERRE, 1788) IN THE SPANISH RECREATIONAL FISHERY IN THE WESTERN MEDITERRARREAN IN THE PERIOD 2005-2019

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    Catch and effort data from the Spanish recreational fishery in the Balearic Sea (Western Mediterranean) were analysed to estimate an index of relative abundance for albacore for the years 2005-2019. Standardized catch per unit effort (CPUE) in number were estimated through a General Linear Mixed Modeling (GLMM) approach under a negative binomial (NB) error distribution assumption. Nominal catch rates and a standardized abundance index are presented along with estimates of 95% confidence limits of the predicted means. These indices show an upward trend from the start of the series 2005 peaking in 2013; followed by a decrease until 2015. For the latest four-year period (2016-2019), the index shows a relatively stable trend fluctuating around a level two times lower than the maximum abundance recorded in the time series.En prens

    Revista de Vertebrados de la EstaciĂłn BiolĂłgica de DoĂąana

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    Pågina 298 con error de impresiónEstudio cariológico en dos especies de Serrånidos del Mediterråneo (Peces: PerciformesRelaciones morfomÊtricas de Atherina boyeri Risso (Pisces: Atherinidae) de la laguna de Zoùar (Córdoba, Espaùa)Contribución al conocimiento de la biometríay osteología de Barbus barbus bocagei, Steindachner, 1866 (Pisces: CyprinidaeLa actividad de la salamandra, Salamandra salamandra (L.), en Galicia.Estudios sobre el sapo corredor (Bufo calamita) en el Sur de Espaùa.1. BiometríaEstudios sobre el sapo corredor (Bufo calamita) en el Sur de Espaùa. II. AlimentaciónBiología de la reproducción de Rana iberica Boulenger 1879 en zonas simpåtridas con Rana temporaria Linneo, 1758Nuevos datos sobre la distribución geogråfica de Lacerta monticola cantabrica Mertens, 1929. (Sauria, lacertidae).Datos sobre Lacerta monticola Boulenger, 1905 (Saurio: lacertidae)en el oeste del Sistema Central.Nueva especie de Anolis (lacertilia, Iguanidae) para CubaEtograma cuantificado del cortejo en Falco naumannOntogÊnesis del comportamiento predador en Falco naumanniContaminación xenobiótica del Parque Nacional de Doùana. 1. Residuos de insecticidas organoclorados, bifenilos policlorados y mercurio en anseriformes y gruiformesReproducción del críalo (Clamator glandarius) en Sierra Morena CentraNidificación de Picus viridis en taludes de arcilla en Ramblas de Guadix (Granada)Comportamiento del calamón Porphyrio porphyrio (Linnaeus, 1758) en Doùana, Marismas del GuadalquiviBiología y ecología de la malvasía (Oxyura leucocephala) en Andalucía.On the differential diet of Carnivora in islands:a method for analysing it and a particular case.Notas sobre la distribución pasada y actual del meloncillo Herpestes ichneumon (L.) en la Península IbÊricaEstructuración de las interacciones en una camada de lobos (Canís lupus)Nuevos datos sobre la distribución del Cottus gobio L. (pisces, cottidae) en EspaùaSobre la alimentación de Callopistes maculatus (Reptilia,teiidaeObservación de Lacerta lepida depredando un nido de Alectoris rufaNueva cita del galåpago leproso Mauremys leprosa (Scheigger, 1812) en los pirineosPrimera cita de Psammodromus hispanicus (Fitzinger) para GaliciaSobre la presencia de Gallotia (=Lacerta) atlantica (Peters y Doria, 1882) en Gran CanariaNota sobre las Lacerta monticola Boulenger, 1905 de las zonas del norte de GaliciaPrimeras notas herpetológicas de la provincia de Soria.Datos sobre selección de håbitat y ecología alimenticia del porrón pardo (Aythya nyroca)Probable nueva årea de cría del pechiazul (Luscinia svecica cyanecula) en el sistema central. PerisPredación de Falco peregrinus y Falco subbuteo sobre quirópterosResultados de la producción de Oxyura leucocephala en el aùo 1981 en las lagunas de Zóùar y el rincónAnålisis de la dieta de Tyto alba en un medio årido antropógeno de los alrededores de Almería¿Son Eudocimus ruber y E. albus distintas especies?EL Estornino pinto (Sturnus vulgaris) en Canarias: nueva especie nidifiante en el archipiÊlagoDatos sobre la alimentación otoùal del cårabo (Strix aluco) en la sierra de CådizObservación primaveral de rapaces y otras aves en el påramo del estado de MÊrida (Venezuela).MurciÊlago hematófago (Desmodus rotundus) parasitando a un chigßire (Hidrochoerus hydrochaeris)Observaciones sobre la reproducción del zacatuche o teporinho Romerolagus diazi (Mammalia: lagomorpha)Estudio electroforÊtico de hemoglobinas y esterasas sanguíneas en Rhinolophus ferrumequinum (Chiroptera: rhinolophidae) y de hemoglobinas en Tadaria taeniotis (chiroptera: molossidae)Peer reviewe

    Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes.

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    8 pĂĄginas, 4 tablas, 8 figuras.The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and managementFinancial support from the Spanish Ministry of the Environment (MMA, project 05/99) and the Junta de AndalucĂ­a (research group 4086)enabled us to carry out the present work.Peer reviewe

    Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes.

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    8 pĂĄginas, 4 tablas, 8 figuras.The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and managementFinancial support from the Spanish Ministry of the Environment (MMA, project 05/99) and the Junta de AndalucĂ­a (research group 4086)enabled us to carry out the present work.Peer reviewe

    The exposure of the hybrid detector of the Pierre Auger Observatory

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    The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The "hybrid" detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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