613 research outputs found

    Development of Magnetostrictive Transducer Prototype for Blockage Detection on Molten Salt Pipes

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    In solar thermal power plants molten salt is often used to store and transport the energy that is collected during the day. The external pipe temperature is measured to activate an electric heating system if the temperature approaches the melting point. However, salt solidification cannot be completely excluded from the plant management. Once occurred, the location of a salt blockage is very complex due to the high temperature of the pipe. Therefore, when this problem arises, power plants have to stop production with the consequences in time and cost that this entails. Electro-magnetic acoustic transducers can be used as non-destructive testing systems for this application. A method for salt blockage detection is proposed that is applicable in straight sections of pipes by employing torsional guided waves that are generated with magnetostrictive transducers. The present paper deals with the transducer conception and the design of the power supply to activate it. Two alternatives are proposed and compared to determine the improvement in the amplitude/noise ratio. Finally, the experimental results show the performance of the equipment in a small prototype, thus validating the technique presented

    Variability in grape composition and phenology of 'Tempranillo' in zones located at different elevations and with differences in the climatic conditions

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    The objective of this research was to analyse the variability on phenology and berry composition of 'Tempranillo' among different elevations and different climatic conditions. The study was conducted on 'Tempranillo' vineyards located in Rioja DOCa at elevations between 367 and 650 m a.s.l. Phenology and the evolution of berry composition during ripening, related to pH, total acidity, malic acid, total anthocyanins, total polyphenols index, colour intensity and sugar content were analysed for the period 2008-2018 at each elevation. The weather conditions recorded during the period of study were evaluated. The results indicate that, on average, differences between the analysed elevations of up to 21 days existed in the dates in which the maturity was reached, being the differences higher in the years with extreme conditions (very wet or dry and very hot or cool). The comparative analysis among elevations and in years with differences in temperature and in precipitation allowed knowing the differences in the vine response under different climatic conditions. From this analysis some conclusions may be extracted that may be useful for police makers to define new planting areas in which less imbalanced situations may occur under warm conditions

    Interannual and spatial variability of grape composition in the Rioja DOCa show better resilience of cv. graciano than cv. tempranillo under a warming scenario

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    Weather conditions affect vine development and grape composition, although the response may be different depending on the variety and altitude. Under scenarios of climate change, the knowledge of the relationships between grape composition and climate is therefore important to know the suitability of a given cultivar. In this research, the variability of the grape composition of two red varieties with different phenological timings (Vitis vinifera L. cv. Tempranillo and Graciano) cultivated in Rioja DOCa (Spain) and the climatic variables that have a higher effect on the response of each of them were analysed. Grape composition of both cultivars at technical maturity (considered when a probable volumetric alcoholic degree (PVAD) = 13 º was reached) was analysed during the period 2008–2020 in areas located at different elevations and related to the weather conditions recorded in those areas. The results show the effect of temperature and water availability in different periods during the growing cycle on grape composition and the potential benefits of cultivating at a higher elevation, under higher water availability. The anthocyanins were affected by the maximum temperatures recorded in the period before veraison and during ripening (period veraison to technical maturity), decreasing their concentrations with increasing temperatures. In addition, higher water availability gave rise to an increase in acidity. Graciano is shown as a variety more suitable than Tempranillo to be cultivated under warmer conditions

    Projecting changes in phenology and grape composition of 'Tempranillo' and 'Grenache' varieties under climate warming in Rioja DOCa

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    The aim of this research was to predict the changes in vine phenology under future climate change of two red varieties, cultivated under rainfed conditions, and how grape composition can be affected. The research was conducted in Rioja Designation of Origin (DOCa), a viticultural area located in north central Spain, where red varieties represent near 90 % of the cultivated vineyards. The research focuses on 'Tempranillo' and 'Grenache', which represent about 85 % and 10 %, respectively, of cultivated red varieties in the area. The analysis included data related to vineyards located at different elevations and with different climatic conditions, recorded during the period 2008-2018. Phenological dates related to separated flowers (stage H), veraison (stage M) and maturity of the two varieties as well as the grape composition during the ripening period and at maturity were evaluated. The future scenarios were based on the predicted temperature and precipitation changes under two Representative Concentration Pathway (RCP) scenarios –RCP4.5 and RCP8.5-, which were simulated with an ensemble of models. Projections for 2050 and 2070 were made based on the observed phenological dates and the heat accumulation needed to reach each stage along the growing cycle. An advance of all phenological stages was projected, higher for veraison and maturity than for the earlier stages, and without large differences between both varieties but with differences at different elevations. Veraison is expected to be advanced up to 11 days for 2050 and up to 12 days for 2070 under the RCP4.5 scenario, while under the RCP8.5 scenario, the advance by 2070 could be up to 20 days for both varieties. For maturity, the advance could be up to 27 days for 'Tempranillo' and 25 days for 'Grenache', with differences between the cooler and the warmer areas. These changes resulted in a shortening of the periods between phenological stages, giving rise to maturity under warmer conditions. Based on the variability of grape composition observed in the warmer in relation to cooler years, and on the relationship with climate variables, a decrease in acidity as well as a reduction in the content of total anthocyanins is expected for both varieties, which may be higher for 'Grenache' than for 'Tempranillo'

    Variability cognitive profile in children and adults with Down syndrome. A neuropsychological study

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    Introducción: El síndrome de Down (SD) es una alteración cromosómica que presenta un fenotipo cognitivo y conductual específico y de una gran complejidad. Objetivos: estudiar el grado de variabilidad del perfil cognitvo a través de pruebas de diagnóstico neuropsicológico en dos edades claramente diferenciadas del desarrollo: edad escolar y edad aulta. Participantes y métodos: Se estudiaron 105 sujetos de edad infantil y adulta, 43 con SD y 62 sin SD. Se valoraron variables neuropsicológicas. Se realizó estudio comparativo de las diferentes variables neuropsicológicas entre los grupos SD y comparación, y entre los grupos infantiles y adultos. Resultados: Los grupos SD infantil y adulto presentaron un rendimiento neuropsicológico significativamente (p<0.05) más bajo que los grupos control. El 84% de las variables neuropsicológicas estudiadas en el grupo SD infantil mostraron un significativo grado de variabilidad (p<0.05), en el grupo SD adulto apareció un 44% de las variables estudiadas con un significativo grado de variabilidad. Conclusiones: El rendimiento neuropsicológico es deficitario en todas las áreas cognitivas estudiadas con diferente grado de representación según la función cognitiva, y con un alto grado de variabilidad cognitiva, especialmente en la edad infantil.Introduction: Down syndrome (DS) is a chromosomal disorder that has a specific and highly complex cognitive and behavioral phenotype. Objectives: To study the degree of variability cognitvo profile through neuropsychological diagnostic tests into two distinct developmental ages : aulta school age and older. Participants and Methods: 105 subjects aged child and adult, 43 with and 62 without SD SD were studied. Neuropsychological variables were assessed. Comparative study of different neuropsychological variables between SD and comparison groups was performed, and between groups of children and adults. Results: Children and adult SD neuropsychological performance groups had significantly (p < 0.05) lower than the control groups. 84% of the neuropsy- chological variables studied in child SD group showed a significant degree of variability (p < 0.05 ) in the SD group showed adult 44% of the studied variables with a significant degree of variability. Conclusions: The neuropsychological performance in all cognitive deficit in study areas with different levels of representation according to cognitive function, and with a high degree of cognitive variability, especially in childhood.peerReviewe

    Effect of various extraction systems on the antioxidant activity kinetic and color of extracts from purple corn

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    The purpose of this study was to investigate the effect of extraction systems on the anthocyanin index, antioxidant kinetics (DPPH-radical scavenging capacity) and color of purple corn (Zea mays) seeds. The factors studied were: extraction system (methanol, 100%, 80%, 60%, 40, 20% v/v) using hydrochloric acid as a means of acidifying. Tristimulus colorimetry was applied to evaluate quantitatively and qualitatively the process. The estimated effect and ANOVA parameters were calculated. The anthocyanins index in different extraction systems was between 1.09 to 2.87 mg/g. The highest anthocyanin index was obtained at an extraction system of 100% methanol. To determine their radical scavenging capacity, the second-order rate constant for the oxidation of these extraction systems measured by the DPPH (1,1-diphenyl-2-picrylhydrazyl radical) method, ranged from 1.19x10-2 to 1.27x10-2 (mg/mL)-1(s-1). The greatest second-order rate constant was obtained at an extraction system of 60% methanol. Regarding the simple regressions analysis the anthocyanin index showed a better relationship with CIELAB parameters: (L*; r =-0.928, p < 0.05), (a*; r = 0.982, p < 0.01), (b*; r = 0.927, p < 0.05), (C*ab; r = 0.9793, p < 0.01) and (hab; r = -0.936, p < 0.05). However, the correlation existing between color parameters and the second-order rate constant did not show a good relationship. When multiple linear regression analysis were applied considering the angular coordinates (L*, C*ab, hab) as independent variable values, a R2 nearing 1 was obtained for anthocyanins index. While a value of R2 = 0.63 was obtained for the second-order rate constant

    Energía y confort. La evolución histórica de la fachada en la arquitectura occidental

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    [EN] The envelope is considered to be the boundary between the outside and the inside of a building. The aim of this study is to analyze both the process that led the concept of the façade to evolve in Western architecture and the repercussions of such evolution, focusing on energy consumption and comfort. The entire evolution of the façade has been closely related to the evolution of materials and construction technologies. The comfort and energy characteristics of architecture have always been determined by the materials and construction technologies employed in façades. Architecture has improved in technical aspects, especially in terms of lighting and thermal comfort. Nevertheless, thermal comfort is usually linked to energy consumption, which is the parameter that has increased the most in this development, with the only exception being sustainable architecture.[ES] La envolvente se considera el límite entre el exterior y el interior de un edificio. El objetivo de este estudio es analizar el proceso que llevó a la evolución del concepto de fachada en la arquitectura occidental y las repercusiones de dicha evolución, centrándose en el consumo energético y el confort. Toda la evolución de la fachada ha estado estrechamente relacionada con la evolución de los materiales y las tecnologías de la construcción. El confort y las características energéticas de la arquitectura siempre han estado determinados por los materiales y tecnologías de construcción empleadas en las fachadas. La arquitectura ha mejorado en aspectos técnicos, especialmente en términos de iluminación y confort térmico. Sin embargo, el confort térmico suele estar ligado al consumo de energía, que es el parámetro que más ha aumentado en esta evolución, con la única excepción de la arquitectura sostenible.Sánchez-Ramos, I.; Raposo Grau, JF.; Meseguer-Garrido, F.; Mediavilla-Martín, D. (2022). Energy and comfort. The historical evolution of the façade in Western Architecture. VLC arquitectura. Research Journal. 9(2):179-200. https://doi.org/10.4995/vlc.2022.165421792009

    Resultados a largo plazo del tratamiento de las fracturas de rótula mediante hemipatelectomia

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    Han sido revisadas retrospectivamente 48 fracturas de rótula tratadas mediante hemipatelectomía, con un seguimiento medio de 14,6 años. Para la valoración se han seguido criterios clínicos, radiológicos, subjetivos y de potencia del aparato extensor. El rango de movilidad de la extremidad intervenida es del 89%, la potencia del aparato extensor de 83% y la medición de la circunferencia del muslo del 97%, tomando como referencia la extremidad no intervenida. Encontramos un 45% de resultados excelentes, 39,58% de buenos resultados, 10,41% de resultados regulares y 4,16% de malos resultados. Existe una relación estadísticamente significativa entre el tipo de fractura, la edad de los pacientes, la existencia de patología previa en la rodilla, las lesiones asociadas a la fractura rotuliana por el traumatismo y el resultado final obtenido. A la vista de estos resultados podemos concluir que la hemipatelectomía es una técnica eficaz y segura para el tratamiento de algunos tipos de fracturas de rótula.A retrospective stydy was made of 48 patellar fractures who were threated with a hemipatellectomy. The mean time of follow-up was 14,6 years. The results were assessed with use of clinical, radiological, subjective and isokinetic quadriceps strength-testing criteria. The mean active range of motion was 89%, the strength of quadriceps was 83% and the circumference of the thigh was 97% of these measurements in the contralateral extremity. The over-all results was rated as excellent in 45,83%, dood in 39,58%, fair in 10,41% and poor in 4,16%. There was a significant statistical correlation between the type of fracture, the previous patology in the knee, the associated lesions caused by trauma and the outcome. The results of this study indicate that hemipatellectomy can be an effective and secure treatment for selected patellar fractures

    Emergence of glassy features in halomethane crystals

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    Both structural glasses and disordered crystals are known to exhibit anomalous thermal, vibrational, and acoustic properties at low temperatures or low energies, what is still a matter of lively debate. To shed light on this issue, we studied the halomethane family CBrnCl4-n (n = 0, 1, 2) at low temperature where, despite being perfectly translationally ordered stable monoclinic crystals, glassy dynamical features had been reported from experiments and molecular dynamics simulations. For n = 1, 2 dynamic disorder originates by the random occupancy of the same lattice sites by either Cl or Br atoms, but not for the ideal reference case of CCl4. Measurements of the low-temperature specific heat (Cp) for all these materials are here reported, which provide evidence of the presence of a broad peak in Debye-reduced Cp(T )/T 3 and in the reduced density of states (g(¿)/¿2) determined by means of neutron spectroscopy, as well as a linear term in Cp usually ascribed in glasses to two-level systems in addition to the cubic term expected for a fully ordered crystal. Being CCl4 a fully ordered crystal, we also performed density functional theory (DFT) calculations, which provide unprecedented detailed information about the microscopic nature of vibrations responsible for that broad peak, much alike the “’boson peak” of glasses, finding it to essentially arise from a piling up (at around 3–4 meV) of low-energy optical modes together with acoustic modes near the Brillouin-zone limits.Peer ReviewedPostprint (published version
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