775 research outputs found
Application of the acousto-optic effect to pressure measurements in ultrasound fields in water using a laser vibrometer
Degradation of LaMnO{3-y} surface layer in LaMnO{3-y}/ metal interface
We report electrical measurements showing the degradation processes of
LaMnO (LaMnO) in LaMnO/normal metal interface in both point contact and
planar-type junctions. Immediately after the preparation of the interface, the
degradation process was followed by measuring the evolution of the junction
resistance versus time. This process is characterized by the appearance of a
second maximum in the resistance vs. temperature (R-T) dependence at
temperatures lower than the Curie temperature T, at which the
metal-insulator transition occurs in the bulk. These effects are explained in
terms of the formation of a depleted interface layer in LaMnO caused by an
out-diffusion of oxygen from the manganite surface to the normal metal. This
assumption is confirmed by XPS measurement. Similar results on LaSrMnO
interfaces are also obtained.Comment: 4 pages, 3 figures, accepted for publication in Appl. Phys.
Lett.(2002
Contribution of orbital forcing and Deccan volcanism to global climatic and biotic changes across the Cretaceous-Paleogene boundary at Zumaia, Spain
Untangling the timing of the environmental effects of Deccan volcanism with respect to the Chicxulub impact is instrumental to fully assessing the contributions of both to climate change over the Cretaceous-Paleogene boundary (KPB) interval. Despite recent improvements in radiometric age calibrations, the accuracy of age constraints and correlations is insufficient to resolve the exact mechanisms leading to environmental and climate change in the 1 m.y. across the KPB. We present new high-resolution planktic foraminiferal, geochemical, and geophysical data from the Zumaia section (Spain), calibrated to an updated orbitally tuned age model. We provide a revised chronology for the major carbon isotope excursions (CIEs) and planktic foraminiferal events and test temporal relationships with different models of the eruptive phases of the Deccan Traps. Our data show that the major CIEs near the KPB, i.e., the late Maastrichtian warming event (66.25–66.10 Ma) and the Dan-C2 event (65.8–65.7 Ma), are synchronous with the last and the first 405 k.y. eccentricity maximum of the Maastrichtian and the Danian, respectively, and that the minor Lower C29n event (65.48–65.41 Ma) is well constrained to a short eccentricity maximum. Conversely, we obtained evidence of abrupt environmental change likely related to Deccan volcanism at ca. 65.9 Ma, based on a bloom of opportunistic triserial guembelitriids (Chiloguembelitria). The orbital, isotopic, and paleobiological temporal relationships with Deccan volcanism established here provide new insights into the role of Deccan volcanism in climate and environmental change in the 1 m.y. across the KPB. © 2021. The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license
Biostratigraphic study with planktic foraminifera of the Santonian-Campanian in the Deba-Zumaia section (Gipuzkoa): New biozonation with heterohelicids
A biostratigraphic study with Santonian and Campanian planktic foraminifera was carried out in the turbiditic facies of the coastline between Deba and Zumaia (Gipuzkoa), which comprises the Itziar and Aguinaga formations. Due to the low abundance of planktic foraminifera, particularly in globotruncanids, the biostratigraphic study was based on species belonging to the group of heterohelicids. We have identified 7 biozones, one of which (Sigalia rugocostata Zone) has been defined in this work. The position of the Santonian/Campanian boundary has been recognized for the first time in the Basque Coast Geopark through the use of this new biozonation with heterohelicidsSe ha realizado un estudio bioestratigráfico con foraminÃferos planctónicos del Santoniense y Campaniense en las facies turbidÃticas del tramo litoral entre Deba y Zumaia (Guipúzcoa), el cual comprende las formaciones Itziar y Aguinaga. Debido a la escasez de foraminÃferos planctónicos del grupo de globotruncánidos, el estudio bioestratigráfico se ha basado en especies pertenecientes al grupo de los heterohelÃcidos. Se han identificado 7 biozonas, una de las cuales (Zona de Sigalia rugocostata) ha sido definida en este trabajo. Esta nueva biozonación ha permitido reconocer por primera vez la posición del lÃmite Santoniense/Campaniense en el Geoparque de la Costa Vasc
DEM-based modelling framework for spray-dried powders in ceramic tiles industry : part I : calibration procedure
DEM-based modelling framework for spray-dried powders in ceramic tiles industry : part II : solver implementation
Respiring mitochondria determine the pattern of activation and inactivation of the store-operated Ca2+ current ICRAC
Temperature-Dependent Dynamic on Resistance in Gamma-Irradiated AlGaN/GaN Power HEMTs
Dynamic RON is a key parameter in terms of device reliability and the efficiency of power-switching converters. In this study, commercial off-the-shelf GaN-on-Si power high-electron-mobility transistors (HEMTs) were irradiated using different regimes of accumulative gamma rays with a 60Co source of photon energy (1.33 MeV), while a base temperature of 53 °C and 133 °C during the irradiation test was applied. This test campaign had the objective of investigating how the combination of gamma irradiation and temperature affects dynamic on-resistance (RON) behaviour. The results indicated that gate voltage bias stress affected the degradation of dynamic on-resistance when irradiation was applied, and that temperature was an accelerating factor in dynamic on-resistance degradation. Finally, we obtained a partial reduction in dynamic RON when a total ionising dose of around 140 krad(SiO2) was applied and the base temperature during the irradiation test was not high
Rotura bilateral de tendón cuadricipital asociado a tratamiento con atorvastatina.
La rotura del tendón del cuádriceps es una lesión relativamente poco frecuente. Puede asociarse a
enfermedades sistémicas, trasplante renal, tratamientos crónicos u ocurrir de forma espontánea. Presentamos un
caso de rotura bilateral de cuádriceps asociada a tratamiento crónico con atorvastatina.Quadriceps tendon rupture is a relatively rare lesion. It has been associated with chronic systemic
diseases, renal transplantation or it may occur spontaneously. We present a case of bilateral quadriceps tendon
rupture associated with chronic atorvastatin treatment
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