1,112 research outputs found

    On the presence of Trachinus pellegrini (Trachinidae) in the Canary and Cape Verde Islands (north-eastern Atlantic)

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    Présence de Trachinus pellegrini (Trachinidae) aux îles Canaries etCanaries et aux îles du Cap-Vert (Atlantique nord-est). Trachinus pellegrini Cadenat, 1937 est signalée pour la première fois aux îles Canaries, ce qui représente sa limite de répartition la plus septentrionale. Les différences morphologiques entre adultes et juvéniles sont également présentées. La présence de cette espèce aux îles du Cap-Vert est aussi confirmée.Postprin

    Influence of temperature and time on the Eu3+ reaction with synthetic Na-Mica-n (n = 2 and 4)

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    Bentonite is accepted as the best clay material for the engineered barrier of Deep Geological Repositories (DGRs). The performance of clay as the main component of the engineered barrier in the DGR has been intensively studied and the structure of the selected clay mineral play a crucial role. In this sense, a new family of synthetic swelling silicates, Na-Mica-n, with tuned layer charge (n) values between 2.0 and 4.0 per unit cell has recently been synthesized and a general synthetic method has been reported. These swelling high-charge micas could be highly valuable for the decontamination of harmful cations. The ability of these micas to immobilize Eu3+ under subcritical conditions has been probed. The adsorption was in both non-specific sites (cation exchange mechanism) and specific sites (chemical reaction or surface defects adsorption). Moreover, its adsorption capacity, under the same conditions is higher than in saponite and far superior to the bentonites.Junta de Andalucía P12-FQM-567European Union 29178

    Procedimiento para modular las propiedades eléctricas de óxidos con estructura tipo perovskita derivados del niobato de sodio mediante la creación de vacantes catiónicas

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    Procedimiento para modular las propiedades eléctricas de óxidos con estructura tipo perovskita derivados del niobato de sodio mediante la creación de vacantes catiónicas. La presente invención se refiere a un procedimiento para modificar controladamente las propiedades eléctricas del óxido NaNbO3 mediante la creación de vacantes catiónicas en la subred A de la estructura tipo perovskita. La introducción progresiva de vacantes en la subred A al dopar con un ión alcalinotérreo como por ejemplo Sr2+ o con un ión de tierra rara como por ejemplo La3+ permite la estabilización de un material ferroeléctrico, y el cambio continuo de comportamiento ferroeléctrico a ferroeléctrico-relaxor característico de las disoluciones sólidas tipo perovskita sin plomo. La presente invención incluye el procedimiento para la obtención de los óxidos que, en función de sus propiedades, pueden ser usados en dispositivos electrónicos como materiales piezoeléctricos y piroeléctricos en sensores y actuadores.Universidad Complutense de Madrid, Consejo Superior de Investigaciones Científicas (España)A1 Solicitud de patentes con informe sobre el estado de la técnic

    Experimental study on the flow-induced vibrations of a circular cylinder with a rear flexibly hinged splitter plate

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    The flow around a circular cylinder is a canonical configuration that may be encountered in many engineering applications, as for instance, civil engineering, architecture, or marine structures. In particular, when bluff bodies are slender and feature low mass-damping characteristics, they may undergo flow-induced vibrations (FIVs), which may result in severe structural fatigue and damage. Here, we present an experimental study on the effect of flexibly hinged splitter plates in the FIV of a flexibly mounted circular cylinder (of diameter D) subject to an uniform cross-flow of velocity u∞. The dynamic response and forcing of the low mass-damping system is characterized for plates of different lengths Lp and different values of the torsional stiffness of the hinge kp. Reductions of the dynamic response of more than 90% can be generally reached at the upper branch, especially when a plate of length l* = Lp/D = 2 with intermediate degree of torsional stiffness is attached, which is shown to represent the best solution as it mitigates the oscillations of the system (cylinder and plate) for the whole range investigated of reduced velocity U* = u∞/fnD = [3:9; 9:8], where fn is the natural frequency of oscillation. In general, the hinged plates are able to attenuate the vortex-induced vibration system response by increasing shedding frequency, until the ratio f* = f/fn > 1 is reached. At high values of U*, a general transition to galloping-like dynamics, characterized by f* < 1, occurs. The tested hinged plates modify the transition between regimes, which is associated with shifts in the phase difference between the forcing and response, combining features of the dynamics of both flexible and static rigid plates already reported in the literature. The use of hinged plates has been proven to provide with a significant attenuation of the system response and its associated drag, a feature that can be considered of practical relevance in many engineering applications. In addition, the key aspects for designing these elements as the torsional stiffness and plate length have been analyzed here.Junta de Andalucía, Universidad de Jaén, and European Funds under Project No. FEDER-UJA 1262764Project Nos. TED2021-131805B-C21 and TED2021-131805B-C22 financed by the Spanish MCIN/AEI/10.13039/501100011033/and the European Union NextGenerationEU/PRTRGrant No. FJC2020-043093-I funded by MCIN/AEI/10.13039/501100011033 and, as appropriate, by “ESF Investing in your future” or by European Union NextGenerationEU/PRTRSpanish MECD through No. FPU20/0726

    Frequency Analysis of a 64x64 Pixel Retinomorphic System with AER Output to Estimate the Limits to Apply onto Specific Mechanical Environment

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    The rods and cones of a human retina are constantly sensing and transmitting the light in the form of spikes to the cortex of the brain in order to reproduce an image in the brain. Delbruck’s lab has designed and manufactured several generations of spike based image sensors that mimic the human retina. In this paper we present an exhaustive timing analysis of the Address-Event- Representation (AER) output of a 64x64 pixels silicon retinomorphic system. Two different scenarios are presented in order to achieve the maximum frequency of light changes for a pixel sensor and the maximum frequency of requested directions on the output AER. Results obtained are 100 Hz and 1.66 MHz in each case respectively. We have tested the upper spin limit and found it to be approximately 6000rpm (revolutions per minute) and in some cases with high light contrast lost events do not exist.Ministerio de Ciencia e Innovación TEC2009-10639- C04-0

    IT-REHAB : Integral Telerehabilitation System

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    The main functionalities of the physical rehabilitation module of IT-REHAB are briefly described in this paper. IT-REHAB is a telerehabilitation system under development for patients with physical or cognitive rehabilitation needs. It supports wireless biomechanical and physiological data collection and includes advanced functionalities based on a custom-designed Medium Access (MAC) protocol for improved bandwidth utilization and an immersive user interface that incorporates virtual reality elements for a motivating experience. Moreover, it includes affective computing technologies for pain intensity estimation, wearables for easy sensor devices setting up, and real-time communication between patients and therapists

    Análisis del plano sagital en las escoliosis idiopáticas tratadas con instrumentación Cotrel-Dubousset

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    Se analiza la evolución del plano sagital en 50 enfermos con escoliosis idiopática intervenidos mediante artrodesis posterior con instrumentación de Cotrel-Dubousset con un seguimiento medio de 72 meses. Se recogieron los valores evolutivos de cifosis torácica medida entre T5 y T12 y de lordosis lumbar medida entre Ll y L5. Las curvas escolióticas fueron clasificadas según King et al. Los resultados obtenidos mostraron que no existía una variación global significativa de la cifosis torácica tras la cirugía. Sólo en aquellos enfermos que previamente existía una hipocifosis torácica existía una mejoría estadísticamente significativa de la misma con la intervención. Se evidenció una clara tendencia al incremento de la cifosis torácica con el tiempo. La lordosis lumbar se mantuvo, en la mayoría de los casos, dentro de límites fisiológicos. La instrumentación de Cotrel-Dubousset ofrece ventajas evidentes respecto a instrumentaciones previas en lo que respecta a la obtención de una curva más fisiológica en el plano sagital. Permite corregir la hipocifosis torácica severa y mantener la lordosis lumbar dentro de límites normales, incluso en instrumentaciones por debajo de L3.Sagittal plane analysis of 50 patients with idiopathic scoliosis treated with Cotrel- Dubousset instrumentation was performed. Mean follow-up was 72 months. The values of thoracic kyphosis from T5 to T12 and lumbar lordosis from L1 to L5 were retrospectively reviewed. Scoliotic curves were classified according to King et al. The results showed that there was not any significant change in thoracic kyphosis after surgery. Only those patients with preoperative thoracic hypokyphosis achieved a significant realignment. There was an obvious increase of thoracic kyphosis with time. Lumbar lordosis was maintained within normal limits in the mayority of patients. Cotrel-Dubousset instrumentation achieves better sagittal alignment than previous systems. It corrects thoracic hypokyphosis and preserves lumbar lordosis, even when the instrumentation is carried out lower than L3

    Assessing sea grass meadows condition at “El Río” Special Area of Conservation off “La Graciosa e Islotes del Norte de Lanzarote” Marine Reserve

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    Cymodosea nodosa meadows, known as ‘sebadales’ or ‘manchones’ at Canary Islands, represent EUNIS habitat type code A5.5311, called Macaronesian Cymodocea beds. As it’s described at European Union Habitats Directive (92/43/CEE) Annex 1, sea grass meadows belong to 1110 Sandbanks which are slightly covered by seawater all the time, within Natura 2000 Network. Several ‘sebadales’ throughout the archipelago are included in this Network as Special Areas of Conservation. Cymodosea nodosa is regionally included within the Canary Islands Protected Species List (Ley 4/2010), as a species ‘of interest to ecosystems of Canary Islands”, is usually found at a narrow depth range (10 to 20 m of depth) and, on the whole, best structured meadows are settled at sheltered bays, away from wave and current beating, flimsier at exposed areas. Deeper meadows are also sparser, being C. nodosa replaced by green algae Caulerpa prolifera and Caulerpa racemosa, although mixed algae-sea grass meadows are often found at different depths. The project Assessment of marine flora (‘sebadal’, ma¨erl, ‘mujo’) of ‘La Graciosa e Islotes del Norte de Lanzarote’ Marine Reserve, funded by ‘Viceconsejer´ıa de Pesca y Aguas de la Consejer´ıa de Agricultura, Ganader´ıa, Pesca y Aguas’, Canary Islands Government, has had the aim of assessing sea grass meadows condition and distribution at ‘El R´ıo’ Natura 2000 Network Special Area of Conservation, the channel between La Graciosa and Lanzarote. ‘LA GRACIOSA 1311’ cruise was performed within the framework of the project. First of all previous information on sea grass shallow distribution (up to a depth of 20 m) in the study area was reviewed. Afterwards, a tugged underwater video camera was used onboard of the Marine Reserve Surveillance Vessel to update cartographic info performing a grid of sampling stations, covering previously known distribution limits and verifying current presence/absence data and density. Furthermore, population parameters were obtained in order to assess ‘sebadal’ condition. Fixed stations were selected in regards to this process, and methodology applied on them was as follows: five radial arranged transects were performed, identifying fragmentation (it estimates meadow continuity regarding observed cover), density (mean value of several shoots number counts with 20 x 20 cm grids placed every 2 m), height (mean value in cm of 10 independent samples by transect) and fish and macroinvertebrate species richness for each transect. Graphic picture of sea grass density was made depending on two levels: low density level transects ( 10 shoots/grid ( 50 shoots/m2) and medium density level transects ( 10 shoots/grid ( 50 shoots/m2). Main study result is an estimate for the study region (‘El R´ıo’) and time of year of Cymodocea nodosa population total distribution cover which comes to 1.640.076 m2, including a higher density ‘sebadal’ of 178.256 m2

    Pyrolysis-compound-specific hydrogen isotope analysis (δ2H Py-CSIA) of Mediterranean olive oils

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    The analysis of the hydrogen stable isotope composition (δ2H) of organic compounds provides information about its geographical origin. In this work, δ2H composition of specific compounds released by direct analytical pyrolysis (Py-CSIA) of extra virgin olive oils EVOOs was studied avoiding the use of any chemical and/or physical treatments, derivatization or previous separation steps. A collection of EVOOs from Mediterranean countries (Portugal, Spain, France, Tunisia and Turkey) was used for authentication of the olive oil samples. The δ2H value for 9 pyrolysis compounds present in all EVOOs, ranged between −112 and −267 mUr. These compounds were selected as possible surrogate descriptors linked to the olive oil geographic origin. Principal Component Analysis showed that δ2H was highly correlated with geographical longitude and annual temperature. Multiple Linear Regression analysis revealed that δ2H value of pyrolysis compounds can significantly (P < 0.05) predicts longitude, mean annual temperature and distance to the sea. The results suggest that the methodology used has a high potential to assess EVOOs geographic origin. This is the first report that evaluates δ2H directly from the pyrolysis products of olive oil using Py-CSIA. The approach used represents an innovative, fast, reproducible and reliable authentication technique

    Physical education and school bullying: a systematic review

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    Objectives: To evaluate the associations of physical education (PE) with school violence and bullying. Design: Systematic review. Method: Using a systematic search in Medline, PsycINFO, SPORTDiscus, Web of Science, and Scopus, relevant studies with a quantitative and qualitative design were identified that met previously established eligibility criteria. Quality was assessed (bias risk analysis) and data were extracted from a previously elaborated template. Results: The systematic review finally included 16 studies, of which 10 had a quantitative design (n = 12795), 5 a qualitative design (n = 79) and 1 a mixed design (n = 86). The high heterogeneity presented by the measures used in the included studies hindered the comparison of the outcomes and prevented meta-analysis of the data. Although there is insufficient evidence about the positive impact of PE on bullying prevention, the results of this review indicate that some aspects of PE programs could improve students’ skills to cope with these situations. Conclusions: The results of this review suggest the importance of PE in the prevention of bullying. Secondly, it is emphasized that bullying situations have a negative impact on students’ enjoyment of PE, leading to detrimental consequences for their physical and psychological health. Thirdly, the figure of the PE teacher as a key element to prevent and/or encourage bullying was obvious
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