124 research outputs found

    Nota sobre la cronología de los fenómenos ígneos en el extremo oriental de la zona sudportuguesa

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    [Resumen] La sucesión magmática se inicia con el vulcanismo preorogénico de la Faja Piritífera, que en el área aquí considerada parece ser de edad Viseense inferiorViseense superior frente a la Tournaisiense-Viseense inferior generalmente admitida. Durante y después de la primera fase de plegamiento (Westfaliense medio) intruyeron gabros, dioritas y granito con moscovita. Tras las fases de plegamiento pero antes de la fracturación tardihercínica se emplazaron los siguientes tipos de rocas ígneas: granito y granodiorita de textura normal, granito y granodiorita de cuarzo globuloso, el granito con granate de El Berrocal, pequeñas masas de tonalitas de grano fino, y abundantes p6rfidos graníticos (Westfaliense D). En el período de fracturación tardía (Estefaniense inferior o medio) intruyeron abundantes diques básicos y algunas aplitas, así como pequeños cuerpos de granodiorita y tonalita de grano fino. Finalmente, extruyeron los basaltos olivínicos de la cuenca del Viar (Estefaniense superior o Autuniense) .[Abstract] The magmatic succesion begins with the geosynclinal volcanism of the Pyrite Belt (Lower to Upper Visean and not Tournaisian-Lower Visean as is established in other localities). During and after the first folding phase, gabbros, diorites and muscovite granite were intruded (Middle Wetphalian). After the phases of folding but before the tardihercynian faulting, there was the following intrusions: granite and granodiorite with normal texture, granite and granodiorite with globular quartz, the body of garnet bearing granite of "El Berrocal", fine grained tonalites, and a number of varied granitic porphyries (Westphalian D). At the time of faulting (Lower or Midle Stephanian) the magmatic activity was represented by abundant basic dikes, aplitic granite and fine grained granodiorite and tonalite. The last igneous rocks in the region are the olivine basalt of the Viar basin (Upper Stephanian or Autunian

    La Orogenia Cadomiense y el rifting del Paleozoico Inferior en el Sudoeste de Iberia

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    La intensidad y la duración de la Orogenia Cadomiense en el sudoeste de Iberia han sido temas controvertidos. El magmatismo calcoalcalino del Vendiense superior, que se encuentra ampliamente representado en la Zona de Ossa Morena, es el efecto orogénico cadomiense más significativo. Además, en las rocas del Proterozoico superior que afloran en Peraleda del Zaucejo (sur de la Zona Centroibérica) se ha establecido firmemente la existencia de foliación y metamorfismos tardiprecámbricos. En la Zona de Ossa Morena, sin embargo, la deformación penetrativa de las rocas precámbricas parece corresponder casi exclusivamente a pliegues y cabalgamientos de edad varisca. En conjunto, la intensidad de la orogenia cadomiense en el sudoeste de Iberia es, como en el resto del Macizo Ibérico, moderada. Los datos geocronológicos existentes aparentan la existencia de un magmatismo initerrumpido desde el Proterozoico superior hasta el Ordovícico; sin embargo, se sugiere que tal continuidad no es real. Del análisis de los datos estratigráficos se deduce que la orogenia cadomiense se habría desarrollado exclusivamente en el Proterozoico terminal, siendo el Cámbrico inferior un período de transición entre el ciclo orogénico cadomiense y el ciclo varisco. Desde el Cámbrico Inferior alto, se desarrolló en la Zona de Ossa Morena el rifting pre-varisco, cuyo reflejo estratigráfico es la sustitución de carbonatos de plataforma (Cámbrico Inferior) por sedimentos terrígenos y rocas volcánicas. Localmente, el rifting pre-varisco originó una fábrica milonítica y un metamorfismo de grado medio-alto, como el que se observa en Valuengo y en Monesterio. Como consecuencia del rifting cambro-ordovícico, la Zona de Ossa-Moreno debió de ser en el Silúrico un fragmento aislado de corteza continental

    Seismic imaging and modelling of the lithosphere of SW-Iberia.

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    [EN]Data from a closely spaced wide-angle transect has been used to study the middle-to-lower crust and the Moho in SW-Iberia. A low-fold wide-angle stack image reveals a highly heterogeneous seismic signature at lower-crustal levels changing laterally along the profile. The lower crust features an irregular distribution of the reflectivity that can be explained by a heterogeneous distribution of physical properties. The Moho discontinuity also features a high variability in its seismic character that correlates with the different tectonic terranes in the area. A 2D finite difference code was used for solving the elastic wave equation and to provide synthetic wide-angle shots. Relatively simple layer cake model derived from conventional refraction interpretation generates the main events of the shot records. However, these models cannot account for the lateral variability of the seismic signature. In order to obtain more realistic simulations, the velocity model was modified introducing stochastic lensing at different levels within the crust. The Moho was modelled as a 3 km thick layered structure. The resulting average velocity models include a high velocity layer at mid-crustal depth, a highly reflective lower crust and a relatively thin horizontal Moho. This heterogeneous model can be achieved by lensing within the crust, a layered mafic intrusion and a strongly laminated lower crust and Moho

    Evaluation of the Components Released by Wine Yeast Strains on Protein Haze Formation in White Wine

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    Cultures of 23 indigenous yeast strains (22 Saccharomyces cerevisiae and a non-Saccharomyces, Torulaspora delbrueckii), isolated from fermentation tanks at wineries in Castilla-La Mancha (Spain), and were performed under winemaking conditions using a synthetic must. Polysaccharide analysis and turbidity assays were conducted so as to observe the capacity of the released mannoproteins against protein haze formation in white wine, and 3 strains (2 Saccharomyces cerevisiae and T. delbrueckii) were chosen for further experiments. The action of a commercial b-glucanolytic enzyme preparation (Lallzyme BETA®), and a β-(1→3)-glucanase preparation from Trichoderma harzianum Rifai were evaluated to release polysaccharides from the different yeast strains’ cell walls. Protection against protein haze formation was strain dependent, and only two strains (Sc2 and Sc4) presented >50% stabilization in comparison to controls. Addition of β-glucanases did not increase the concentrations of polysaccharides in the fermentation musts; however, a significant increase of polymeric mannose (mannoproteins) was detected using an enzymatic assay following total acid hydrolysis of the soluble polysaccharides. Enzymatic treatment presented positive effects and decreased protein haze formation in white wine. DOI http://dx.doi.org/10.17807/orbital.v8i6.86

    Successful management of peri-implantitis around short and ultrashort single-crown implants: a case series with a 3-year follow-up

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    Introduction and Aim. In case of peri-implantitis, resective surgery is contraindicated for short and ultrashort implants, limiting the treatment options to regenerative surgery or to implant removal. 'is retrospective case series presents the clinical and radiographic outcomes of a surgical regenerative procedure to treat peri-implantitis around short and ultrashort implants. Materials and Methods. The study is a retrospective evaluation of patients suffering from peri-implantitis and those who underwent access flap surgery, concomitant chemical and mechanical decontamination of implant surface, and bone grafting using a self-hardening mixture of bone substitutes and biphasic calcium sulfate. No membranes were applied to cover the grafting material, and primary tension-free closure was achieved. The retrospective protocol was reviewed and approved by the Ethics Committee for Clinical Sperimentation (CESC) of Verona and Rovigo, Italy (based in the University of Verona) (Prog. 1863CESC. Date of approval: 2018-07-04). Results. 15 patients (17 implants) have been diagnosed with peri-implantitis after a mean follow-up of 24 months after loading. Implant length was between 5 and 8 mm. 8 patients (10 implants) had a history of periodontitis. At baseline, the mean PD (probing pocket dept) at the deepest site was 8.12 mm, with an average mBI (modified bleeding index) of 2.35 and a mean BD (bone defect depth) of 3.04 mm. At the 3-year follow-up, the CSR was 100%, the mean mBI was 0.88 (average reduction: - 1.47), the mean PD was 3.35 mm (mean PD reduction: 4.77 mm), and the mean bone defect was reduced by 1.74 mm, with a mean bone fill of 55%. Conclusions. The results of the present case series suggest that if accurate surface decontamination is achieved, high survival rate and good clinical and radiographic results can be obtained after 3 years. However, only the histological examination could confirm the growth of new bone in direct contact with the implant surface or if the grafted material only fills the space left by the peri-implant defect

    Recent results on the construction of a new correlator for neutrons and charged particles and for FARCOS

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    With the advent of new facilities for radioactive ion beams it is necessary to develop neutron detection systems integrated with charged-particle ones. The integration of the neutron signal, especially in the case of neutron-rich beams, becomes a mandatory requirement in order to study the property of the nuclear matter in extreme conditions. For this reason, new detectors using new materials have to be built. NArCoS (Neutron ARray for COrrelation Studies) is a project aimed at the design of a new detector based on stack of plastic scintillators, featuring both good energy and angular resolution sensitive both to neutrons and charged particles within the same detection cell. We present in this work new results on the Pulse Shape Discrimination (PSD) capabilities of two very compact detection systems: the 3 x 3 x 3 cm(3) EJ 276+SiPM and the 3 x 3 x 3 cm(3) EJ 276G +SiPM (the latter green shifted version). In addition, we compare new results about the energy calibration and resolution of the FARCOS correlator in the CHIFAR experiment performed at LNS

    Comparación del Neoproterozoico/Paleozoico inferior de Marruecos y del SO de Iberia. Interpretaciones geodinámicas

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    El Neoproterozoico del sudoeste de Iberia (Serie Negra y Formación Malcocinado) es contemporáneo de un magmatismo calcoalcalino (Precámbrico PIII del Anti-Atlas de Marruecos) que sella la Orogenia Cadomiense. El Cámbrico inferior y medio está representado, tanto en Iberia como en Marruecos, por secuencias detríticas y vulcanosedimentarias formadas en un contexto de rifting. Sin embargo, la evolución de estas dos regiones se diferenció a partir del Cámbrico superior: en el sudoeste de Iberia, la actividad extensional continuó durante el Ordovícico, desarrollándose dominios oceánicos; en Marruecos, dominó durante el resto del Paleozoico inferior un régimen de plataforma débilmente extensiona

    La estructura sísmica de la corteza de la Zona de Ossa Morena y su interpretación geológica

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    El experimento de sísmica de reflexión profunda IBERSEIS ha proporcionado una imagen de la corteza del Orógeno Varisco en el sudoeste de Iberia. Este artículo se centra en la descripción de la corteza de la Zona de Ossa Morena (OMZ), que está claramente dividida en una corteza superior, con reflectividad de buzamiento al NE, y una corteza inferior de pobre reflectividad. Las estructuras geológicas cartografiadas en superficie se correlacionan bien con la reflectividad de la corteza superior, y en la imagen sísmica se ven enraizar en la corteza media. Ésta está constituida por un cuerpo muy reflectivo, interpretado como una gran intrusión de rocas básicas. La imagen de las suturas que limitan la OMZ muestra el carácter fuertemente transpresivo de la colisión orogénica varisca registrada en el sudoeste de Iberia. La Moho actual es plana y, en consecuencia, no se observa la raíz del orógeno

    Steel cathodic protection afforded by zinc, aluminium and zinc/aluminium alloy coatings in the atmosphere

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    Zinc has traditionally been the metallic material most widely used to protect steel against atmospheric corrosion due to its ability to afford cathodic protection to steel in all types of natural atmospheres. In recent decades, aluminium and zinc/aluminium alloy coatings have been used instead of zinc in certain atmospheric applications. Although these coatings present some advantages over zinc, they are not able to cathodically protect steel substrates in all types of natural atmospheres. The present paper assesses the cathodic protection afforded by Al (flame spraying), Al/13 Si (hot dipping), 55Al/Zn (hot dipping), Zn/15Al (flame spraying), Zn/5Al (hot dipping), Zn (hot dipping), Zn (discontinuous hot dipping) and Zn (electroplating). Aluminium and aluminium-rich alloy coatings (55%Al/Zn) provide cathodic protection to the steel substrate only in atmospheres that are highly contaminated with chloride ions (>100 mg Cl- m-2 day-1) where these coatings become active. © 2004 Elsevier B.V. All rights reserved.Peer Reviewe
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