30 research outputs found

    Molecular dynamics simulations of defect production in graphene by carbon irradiation

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    We present molecular dynamics simulations with empirical potentials to study the type of defects produced when irradiating graphene with low energy carbon ions (100 eV and 200 eV) and different dose rates. Simulations show the formation of very stable structures such as dimers, single chains of carbons and double chains of carbons. These structures are similar to those described in the literature, observed experimentally when irradiating graphene. For high doses or dose rates, the formation of nanopores is observed, similar to previous results by other authors for higher energies of the implanted ions. These simulations show how tunning the different parameters of irradiation conditions can be used to selectively create defects in graphene.This work is supported by the Generalitat Valenciana through grant reference PROMETEO2012/011 and the Spanish government through grant FIS2010-21883

    Controlled rippling of graphene via irradiation and applied strain modify its mechanical properties: a nanoindentation simulation study

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    Ripples, present in free standing graphene, have an important influence in the mechanical behavior of this two-dimensional material. In this work we show through nanoindentation simulations, how out-of-plane displacements can be modified by strain resulting in softening of the membrane under compression and stiffening under tension. Irradiation also induces changes in the mechanical properties of graphene. Interestingly, compressed samples, irradiated at low doses are stiffened by the irradiation while samples under tensile strain do not show significant changes in their mechanical properties. These simulations indicate that vacancies, produced by the energetic ions, cannot be the ones directly responsible for this behavior. However, changes in roughness induced by the momentum transferred from the energetic ions to the membrane, can explain these differences. These results provide an alternative explanation to recent experimental observations of stiffening of graphene under low dose irradiation, as well as paths to tailor the mechanical properties of this material via applied strain and irradiation.This work is supported by the Generalitat Valenciana through grant reference PROMETEO2012/011 and the Spanish government through grant FIS2010-21883. CJR and EMB thanks support from SeCTyP-UNCuyo grant M003, and ANPCyT grant PICT-2014-0696. CJR thanks CONICET and the 310 Group at FCEN-UNCuyo

    A novel ensemble method for electric vehicle power consumption forecasting: Application to the Spanish system

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    The use of electric vehicle across the world has become one of the most challenging issues for environmental policies. The galloping climate change and the expected running out of fossil fuels turns the use of such non-polluting cars into a priority for most developed countries. However, such a use has led to major concerns to power companies, since they must adapt their generation to a new scenario, in which electric vehicles will dramatically modify the curve of generation. In this paper, a novel approach based on ensemble learning is proposed. In particular, ARIMA, GARCH and PSF algorithms' performances are used to forecast the electric vehicle power consumption in Spain. It is worth noting that the studied time series of consumption is non-stationary and adds difficulties to the forecasting process. Thus, an ensemble is proposed by dynamically weighting all algorithms over time. The proposal presented has been implemented for a real case, in particular, at the Spanish Control Centre for the Electric Vehicle. The performance of the approach is assessed by means of WAPE, showing robust and promising results for this research field.Ministerio de Economía y Competitividad Proyectos ENE2016-77650-R, PCIN-2015-04 y TIN2017-88209-C2-R

    Experiències senzilles de física recreativa: flascó de Mariotte, refracció de la llum i tira d’alumini ondulant

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    En aquest treball presentem una sèrie d’experiments senzills i estimulants de física que resulten útils per a reforçar els coneixements propis d’aquesta matèria, consolidar conceptes físics, captar l’atenció dels estudiants i fomentar-ne l’interès per la matèria de física. En aquesta ocasió hem dissenyat i dut a terme experiències de diversos camps de la Física, com ara fluids (flascó de Mariotte), òptica (refracció de la llum) i magnetisme (tira d’alumini ondulant a causa d’un camp magnètic). Amb aquest tipus d’experiments simples volem augmentar la motivació dels estudiants cap a la matèria de física, ja que l’objectiu d’aquestes experiències és tractar d’entendre el fenomen que s’està observant, en comptes d’obtenir i tractar dades. Aquests experiments estan adreçats als estudiants dels primers cursos dels graus de ciències i de les diverses enginyeries. Aquesta manera d’introduir conceptes de física mitjançant experiments sorprenents fa que l’aprenentatge resulte més significatiu, i constitueixen una eina pedagògica de gran ajuda en el procés d’ensenyament-aprenentatge de la física

    Complications of Macular Peeling

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    Macular peeling refers to the surgical technique for the removal of preretinal tissue or the internal limiting membrane (ILM) in the macula for several retinal disorders, ranging from epiretinal membranes (primary or secondary to diabetic retinopathy, retinal detachment…) to full-thickness macular holes, macular edema, foveal retinoschisis, and others. The technique has evolved in the last two decades, and the different instrumentations and adjuncts have progressively advanced turning into a safer, easier, and more useful tool for the vitreoretinal surgeon. Here, we describe the main milestones of macular peeling, drawing attention to its associated complications

    Establishing normative foot posture index values for the paediatric population: a cross-sectional study

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    Antecedentes: el índice de postura del pie (FPI) es una herramienta de observación diseñada para medir la posición del pie. Su fiabilidad está bien establecida y proporciona valores de referencia normativos para la población en general. Sin embargo, esto no es así para la población pediátrica. El objetivo de este estudio es determinar los valores de referencia de FPI en la infancia, teniendo en cuenta la edad y el sexo. Métodos: este estudio transversal incluyó a 1.762 escolares (863 niños y 899 niñas) de 6 a 11 años, de Málaga, Granada y Plasencia (España). En todos los casos, dos podólogos experimentados obtuvieron las mediciones de FPI en ambos pies. Luego se realizó un análisis descriptivo y se determinaron los percentiles de las variables, con un nivel de significancia de P <0.05. Resultados: Los resultados del FPI consolidado para la población de muestra arrojaron valores medios de 3.74 (SD 2.93) puntos para el pie derecho y 3.83 (SD 2.92) para el izquierdo. El percentil 50 fue de 4 puntos para ambos sexos y para ambos pies, a excepción del pie derecho entre las chicas, que fue ligeramente inferior, en 3 puntos. El percentil 85, que se considera que representa el límite entre el pie normal y el pronado entre los niños, fue de 6 puntos, uniformemente entre los sujetos. Conclusiones: como valor normativo de FPI para la población pediátrica, recomendamos el percentil 50, es decir, 4 puntos, para niños, de ambos sexos, con edades comprendidas entre los 6 años. Este valor disminuye progresivamente con la edad, hasta 3 puntos FPI para niños de 11 años. El percentil 85 para el pie pronated y el percentil 4 para el pie supinado se puede considerar el límite patológico.Background: The Foot Posture Index (FPI) is an observational tool designed to measure the position of the foot. Its reliability is well established, and it provides normative reference values for the general population. However, this is not so for the paediatric population. The aim of this study is to determine FPI reference values in childhood, taking into account age and gender. Methods: This cross-sectional study included 1,762 school children (863 boys and 899 girls) aged 6–11 years, from Málaga, Granada and Plasencia (Spain). In every case, FPI measurements were obtained for both feet by two experienced podiatrists. A descriptive analysis was then conducted and the percentiles of the variables determined, with a significance level of P < 0.05. Results: The consolidated FPI results for the sample population produced mean values of 3.74 (SD 2.93) points for the right foot and 3.83 (SD 2.92) for the left. The 50th percentile was 4 points for both genders and for both feet, except for the right foot among the girls, which was slightly lower, at 3 points. The 85th percentile, which is considered to represent the boundary between the normal and the pronated foot among children, was 6 points, uniformly among the subjects. Conclusions: As a normative FPI value for the paediatric population, we recommend the 50th percentile, i.e. 4 points, for children, of both genders, aged 6 years. This value progressively falls with age, to 3 FPI points for children aged 11 years. The 85th percentile for the pronated foot and the 4th percentile for the supinated foot can be considered the pathological boundary.peerReviewe

    Progreso en la práctica del ajuste gaussiano de una red local: método de Triangulateración

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    Jiménez Martínez, MJ.; Marqués Mateu, Á.; Paredes Asencio, JM.; Villar Cano, M. (2011). Progreso en la práctica del ajuste gaussiano de una red local: método de Triangulateración. RACV Digital. 1-131. http://hdl.handle.net/10251/47995S113

    Experiències senzilles de física recreativa: Conservació del moment lineal, efecte Coandă i emissió atòmica

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    La realització pràctica d’experiments és fonamental en qualsevol disciplina científica. Per això, en aquest treball exposem una sèrie d’experiències de física senzilles i sorprenents que ens permetran reforçar diversos conceptes físics d’una manera amena, utilitzant materials molt assequibles i barats. Amb la realització d’aquests experiments volem estimular la curiositat de l’alumnat i el plaer per la investigació i el descobriment de nous fenòmens físics. Aquestes experiències estan adreçades tant a estudiants d’educació secundària i batxillerat com a alumnes dels primers cursos d’universitat. Hem dissenyat i dut a terme experiències de diversos camps de la física, entre els quals hi ha algunes pràctiques per a posar de manifest la conservació del moment lineal, o l’efecte Coandă en fluids en moviment, i també experiments de física atòmica relacionats amb l’emissió atòmica en l’espectre visible, que posen de manifest la quantització de l’energia dels nivells atòmics. Amb aquestes experiències volem motivar els alumnes en l’estudi i l’interès per la física des d’una perspectiva diferent de l’habitual

    Ajuste Gaussiano de redes por el método de incrementos de coordenadas

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    [EN] We want to introduce a new way of performing the Gauss Markov adjustment of a micro geodetic net with ‘Coordinate increases’. It could be applied to angular and distance measurements, also to GNSS observations. We find it is effective and efficient for the prediction, analysis and interpretation of the results. We demonstrate the importance of the similarity of all measurement weights used in the adjustment. It is also clear that is a good way to avoid dealing with the a priori covariance between measurements. In order to assure the validity of the obtained values we propose checking them using both methods: ‘Coordinate increases’ and ‘Homogeneous triangulateration’ (published in www.racv.es/racv digital)[ES] El método de incrementos de coordenadas es un ajuste Gauss Markov sobre redes microgeodésicas. El método se aplica a observables angulares, distanciométricos y GNSS, por separado o de manera conjunta. El método propone un protocolo de actuación y de predicción análisis e interpretación de los resultados eficaz. Demostramos que es importante que los observables que formen parte del ajuste mínimo cuadrático tengan pesos similares. El método resuelve el problema de las covarianzas a priori entre observables, como sucede habitualmente con los observables GNSS. Proponemos la aplicación del método de triangulateración homogénea (publicado en www.racv.es/racv digital) y del método de incrementos de coordenadas sobre una misma red para verificar la validez de los resultados obtenidos.Jiménez Martínez, MJ.; Quesada Olmo, MN.; Villar Cano, M.; Paredes Asencio, JM.; Marqués Mateu, Á. (2011). Ajuste Gaussiano de redes por el método de incrementos de coordenadas. RACV Digital. 1-205. http://hdl.handle.net/10251/47993S120

    Fruit and Vegetable Consumption is Inversely Associated with Plasma Saturated Fatty Acids at Baseline in Predimed Plus Trial

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    I.D.-L. is supported by the [FI_B 00256] from the FI-AGAUR Research Fellowship Program, Generalitat de Catalunya and M.M.-M is supported by the FPU17/00513 grant. a.-H. is supported by the [CD17/00122] grant and S.K.N. is supported by a Canadian Institutes of Health Research (CIHR) Fellowship. We also thank all the volunteers for their participation in and the personnel for their contribution to the PREDIMED-Plus trial. This research was funded by CiCYT [AGL2016-75329-R] and CIBEROBN from the Instituto de Salud Carlos III, ISCIII from the Ministerio de Ciencia, Innovacion y Universidades, (AEI/FEDER, UE), Generalitat de Catalunya (GC) [2017SGR196]. The PREDIMED-Plus trial was supported by the official Spanish Institutions for funding scientific biomedical research, CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn) and Instituto de Salud Carlos III (ISCIII), through the Fondo de Investigacion para la Salud (FIS), which is co-funded by the European Regional Development Fund (four coordinated Fondo de Investigaciones Sanitarias projects lead by J.S.-S. and J.V., including the following projects: PI13/00673, PI13/00492, PI13/00272, PI13/01123, PI13/00462, PI13/00233, PI13/02184, PI13/00728, PI13/01090, PI13/01056, PI14/01722, PI14/00636, PI14/00618, PI14/00696, PI14/01206, PI14/01919, PI14/00853, PI14/01374, PI14/00972, PI14/00728, PI14/01471, PI16/00473, PI16/00662, PI16/01873, PI16/01094, PI16/00501, PI16/00533, PI16/00381, PI16/00366, PI16/01522, PI16/01120, PI17/00764, PI17/01183, PI17/00855, PI17/01347, PI17/00525, PI17/01827, PI17/00532, PI17/00215, PI17/01441, PI17/00508, PI17/01732, PI17/00926 and PI19/00781), the Especial Action Project entitled Implementacion y evaluacion de una intervencion intensiva sobre la actividad fisica Cohorte PREDIMED-Plus grant to J.S.-S., European Research Council (Advanced Research Grant 2014-2019, 340918) to M.a.M.-G., the Recercaixa grant to J.S.-S. (2013ACUP00194), grants from the Consejeria de Salud de la Junta de Andalucia (PI0458/2013, PS0358/2016, and PI0137/2018), a grant from the Generalitat Valenciana (PROMETEO/2017/017), a SEMERGEN grant, Fundacio la Marato de TV3 (PI044003), 2017 SGR 1717 from Generalitat de Catalunya, a CICYT grant provided by the Ministerio de Ciencia, Innovacion y Universidades (AGL2016-75329-R), and funds from the European Regional Development Fund (CB06/03 and CB12/03). Food companies Hojiblanca (Lucena, Spain) and Patrimonio Comunal Olivarero (Madrid, Spain) donated extra virgin olive oil, and the Almond Board of California (Modesto, CA, USA), American Pistachio Growers (Fresno, CA, USA), and Paramount Farms (Wonderful Company, LLC, Los Angeles, CA, USA) donated nuts. J.K. was supported by the "FOLIUM" program within the FUTURMed project entitled Talent for the medicine within the future from the Fundacio Institut d'Investigacio Sanitaria Illes Balears. This call was co-financed at 50% with charge to the Operational Program FSE 2014-2020 of the Balearic Islands. This work is partially supported by ICREA under the ICREA Academia programme to J.S.-S.Scope: Plasma fatty acids (FAs) are associated with the development of cardiovascular diseases and metabolic syndrome. The aim of our study is to assess the relationship between fruit and vegetable (F&V) consumption and plasma FAs and their subtypes. Methods and Results: Plasma FAs are assessed in a cross-sectional analysis of a subsample of 240 subjects from the PREDIMED-Plus study. Participants are categorized into four groups of fruit, vegetable, and fat intake according to the food frequency questionnaire. Plasma FA analysis is performed using gas chromatography. Associations between FAs and F&V consumption are adjusted for age, sex, physical activity, bodymass index (BMI), total energy intake, and alcohol consumption. Plasma saturated FAs are lower in groups with high F&V consumption (-1.20 mg cL−1 [95% CI: [-2.22, - 0.18], p-value = 0.021), especially when fat intake is high (-1.74 mg cL−1 [95% CI: [-3.41, -0.06], p-value = 0.042). Total FAs and n-6 polyunsaturated FAs tend to be lower in high consumers of F&V only in the high-fat intake groups. Conclusions: F&V consumption is associated with lower plasma saturated FAs when fat intake is high. These findings suggest that F&V consumption may have different associations with plasma FAs depending on their subtype and on the extent of fat intake.Generalitat de Catalunya FI_B 00256Canadian Institutes of Health Research (CIHR)Consejo Interinstitucional de Ciencia y Tecnologia (CICYT)European Commission AGL2016-75329-RCIBEROBN from the Instituto de Salud Carlos III ISCIII from the Ministerio de Ciencia, Innovacion y Universidades, (AEI/FEDER, UE)Generalitat de Catalunya 2017SGR196CIBER Fisiopatologia de la Obesidad y Nutricion (CIBERobn)Instituto de Salud Carlos III (ISCIII), through the Fondo de Investigacion para la Salud (FIS)European Commission PI13/00673 PI13/00492 PI13/00272 PI13/01123 PI13/00462 PI13/00233 PI13/02184 PI13/00728 PI13/01090 PI13/01056 PI14/01722 PI14/00636 PI14/00618 PI14/00696 PI14/01206 PI14/01919 PI14/00853 PI14/01374Especial Action Project entitled Implementacion y evaluacion de una intervencion intensiva sobre la actividad fisica Cohorte PREDIMED-Plus grantEuropean Research Council (ERC) European Commission 340918Recercaixa grant 2013ACUP00194Junta de Andalucia PI0458/2013 PS0358/2016 PI0137/2018Generalitat Valenciana European Commission PROMETEO/2017/017SEMERGEN grant, Fundacio la Marato de TV3 PI044003Generalitat de Catalunya 2017 SGR 1717Ministerio de Ciencia, Innovacion y Universidades AGL2016-75329-R"FOLIUM" program within the FUTURMed project within Fundacio Institut d'Investigacio Sanitaria Illes BalearsICREA under the ICREA Academia programmeThe European Regional Development Fund PI17/01347 PI17/00525 PI17/01827 PI17/00532 PI17/00215 PI17/01441 PI17/00508 PI17/01732 PI17/00926 PI19/00781 CB06/03 CB12/03European Commission PI14/00972 PI14/00728 PI14/01471 PI16/00473 PI16/00662 PI16/01873 PI16/01094 PI16/00501 PI16/00533 PI16/00381 PI16/00366 PI16/01522 PI16/01120 PI17/00764 PI17/01183 PI17/00855 FPU17/00513 CD17/0012
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