1,083 research outputs found

    Propuesta de herramientas objetivas de evaluación de asignaturas experimentales de ingeniería química

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    En este trabajo se presenta una metodología de evaluación objetiva aplicada a una asignatura de tipo experimental “Experimentación en Ingeniería Química II” que se imparte en la titulación de Ingeniero Químico de la Universidad de Valladolid. Esta evaluación de tipo formativo se basa en el desarrollo de una serie de cuestionarios o rúbricas de evaluación que permiten valorar de forma objetiva todos los conocimientos, habilidades, destrezas, actitudes, aptitudes, competencias, vínculos y capacidades que deben desarrollar los alumnos. El proceso se completa con la elaboración de una guía de autoevaluación para el profesor que le permitirá, junto con la encuesta docente institucional, realizar un análisis sistemático de su actividad docente.Peer Reviewe

    Thermal equilibrium and statistical thermometers in special relativity

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    There is an intense debate in the recent literature about the correct generalization of Maxwell's velocity distribution in special relativity. The most frequently discussed candidate distributions include the Juettner function as well as modifications thereof. Here, we report results from fully relativistic one-dimensional (1D) molecular dynamics (MD) simulations that resolve the ambiguity. The numerical evidence unequivocally favors the Juettner distribution. Moreover, our simulations illustrate that the concept of 'thermal equilibrium' extends naturally to special relativity only if a many-particle system is spatially confined. They make evident that 'temperature' can be statistically defined and measured in an observer frame independent way.Comment: version accepted for publication (5 pages), part of the introduction modified, new figures, additional reference

    In-Line estimation of the standard colour index of citrus fruits using a computer vision system developed for a mobile platform

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s11947-012-1015-2A key aspect for the consumer when it comes to deciding on a particular product is the colour. In order to make fruit available to consumers as early as possible, the collection of oranges and mandarins begins before they ripen fully and reach their typical orange colour. As a result, they are therefore subjected to certain degreening treatments, depending on their standard colour citrus index at harvest. Recently, a mobile platform that incorporates a computer vision system capable of pre-sorting the fruit while it is being harvested has been developed as an aid in the harvesting task. However, due to the restrictions of working in the field, the computer vision system developed for this machine is limited in its technology and processing capacity compared to conventional systems. This work shows the optimised algorithms for estimating the colour of citrus in-line that were developed for this mobile platform and its performance is evaluated against that of a spectrophotometer used as a reference in the analysis of colour in food. The results obtained prove that our analysis system predicts the colour index of citrus with a good reliability (R2 = 0.925) working in real time. Findings also show that it is effective for classifying harvested fruits in the field according to their colour. © 2012 Springer Science+Business Media New York.This work was partially funded by the INIA through research project RTA2009-00118-C02-01 with the support of European FEDER funds, and by the project PAID-05-11-2745, Vicerectorat d'Investigacio, Universitat Politecnica de Valencia.Vidal, A.; Talens Oliag, P.; Prats-Montalbán, JM.; Cubero García, S.; Albert Gil, FE.; Blasco Ivars, J. (2013). In-Line estimation of the standard colour index of citrus fruits using a computer vision system developed for a mobile platform. Food and Bioprocess Technology. 6(12):3412-3419. https://doi.org/10.1007/s11947-012-1015-2S34123419612Arzate-Vázquez, I., Chanona-Pérez, J. J., Perea-Flores, M. J., Calderón-Domínguez, G., Moreno-Armendáriz, M. A., Calvo, H., Godoy-Calderón, S., Quevedo, R., & Gutiérrez-López, G. (2011). Image processing applied to classification of avocado variety Hass (Persea americana Mill.) during the ripening process. Food and Bioprocess Technology, 4(7), 1307–1313.Blasco, J., Aleixos, N., Cubero, S., Gómez-Sanchis, J., & Moltó, E. (2009). Automatic sorting of satsuma (Citrus unshiu) segments using computer vision and morphological features. Computers and Electronics in Agriculture, 66, 1–8.Campbell, B. L., Nelson, R. G., Ebel, C. E., Dozier, W. A., Adrian, J. L., & Hockema, B. R. (2004). Fruit quality characteristics that affect consumer preferences for satsuma mandarins. HortScience, 39(7), 1664–1669.Cavazza, A., Corradini, C., Rinaldi, M., Salvadeo, P., Borromei, C., & Massini, R. (2012). Evaluation of pasta thermal treatment by determination of carbohydrates, furosine, and color indices. Food and Bioprocess Technology. doi: 10.1007/s11947-012-0906-6 . In-press.Cubero, S., Aleixos, N., Moltó, E., Gómez-Sanchis, J., & Blasco, J. (2011). Advances in machine vision applications for automatic inspection and quality evaluation of fruits and vegetables. Food and Bioprocess Technology, 4(4), 487–504.Cubero, S., Moltó, E., Gutiérrez, A., Aleixos, N., García-Navarrete, O. L., Juste, F., & Blasco, J. (2010). Real-time inspection of fruit on a mobile harvesting platform in field conditions using computer vision. Progress in Agricultural Engineering Science, 6, 1–16.Díaz, R., Faus, G., Blasco, M., Blasco, J., & Moltó, E. (2000). The application of a fast algorithm for the classification of olives by machine vision. Food Research International, 33, 305–309.DOGV (2006) Diari Oficial de la Comunitat Valenciana, 5346, 30321-30328.Gardner, J. L. (2007). Comparison of calibration methods for tristimulus colorimeters. Journal of Research of the National Institute of Standards and Technology, 112, 129–138.Hashim, N., Janius, R. B., Baranyai, L., Rahman, R. A., Osman, A., & Zude, M. (2011). Kinetic model for colour changes in bananas during the appearance of chilling injury symptoms. Food and Bioprocess Technology, 5(8), 2952–2963.HunterLab (2008): Applications note, 8(9), http://www.hunterlab.com/appnotes/an08_96a.pdf . Accessed September 2012.Hutchings, J. B., Luo, R., & Ji, W. (2002). Calibrated colour imaging analysis of food. In D. MacDougall (Ed.), Colour in Food (pp. 352–366). Cambridge: Woodhead Publishing.Jiménez-Cuesta MJ, Cuquerella J & Martínez-Jávega JM (1981) Determination of a color index for citrus fruit degreening. In Proc. of the International Society of Citriculture, Vol. 2, 750-753Kang, S. P., East, A. R., & Trujillo, F. J. (2008). Colour vision system evaluation of bicolour fruit: A case study with ‘B74’ mango. Postharvest Biology and Technology, 49, 77–85.Lang, C., & Hübert, T. (2011). A colour ripeness indicator for apples. Food and Bioprocess Technology, 5(8), 3244–3249.López-Camelo, A. F., & Gómez, P. A. (2004). Comparison of color indexes for tomato ripening. Horticultura Brasileira, 22(3), 534–537. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362004000300006 .López-García, F., Andreu-García, A., Blasco, J., Aleixos, N., & Valiente, J. M. (2010). Automatic detection of skin defects in citrus fruits using a multivariate image analysis approach. Computers and Electronics in Agriculture, 71, 189–197.Lorente, D., Aleixos, N., Gómez-Sanchis, J., Cubero, S., García-Navarrete, O. L., & Blasco, J. (2012). Recent advances and applications of hyperspectral imaging for fruit and vegetable quality assessment. Food and Bioprocess Technology, 5(4), 1121–1142.Mendoza, F., Dejmek, P., & Aguilera, J. M. (2006). Calibrated color measurements of agricultural foods using image analysis. Postharvest Biology and Technology, 41, 285–295.Montgomery, D. C. (2005). Design and analysis of experiments, 6th ed. Tempe: Wiley.Noboru, O., & Robertson, A. R. (2005). Colorimetry. West Sussex: Wiley.Pathare, P. B., Opara, U. L., & Al-Said, F. A. (2012). Colour measurement and analysis in fresh and processed foods: a review. Food and Bioprocess Technology. doi: 10.1007/s11947-012-0867-9 . In-press.Quevedo, R. A., Aguilera, J. M., & Pedreschi, F. (2010). Colour of salmon fillets by computer vision and sensory panel. Food and Bioprocess Technology, 3, 637–643.Sahin, S., & Sumnu, S. G. (2006). Physical properties of foods. New York: Springer.Quevedo, R., Valencia, E., Alvarado, F., Ronceros, B., & Bastias, J. M. (2011). Comparison of whiteness index vs. fractal Fourier in the determination of bloom chocolate using image analysis. Food and Bioprocess Technology. doi: 10.1007/s11947-011-0729-x . In-press.Smith, T., & Guild, J. (1931). The C.I.E. colorimetric standards and their use. Transactions of the Optical Society, 33(3), 73–134.Yam, K. L., & Papadakis, S. E. (2004). A simple digital imaging method for measuring and analyzing color of food surfaces. Journal of Food Engineering, 61, 137–142

    Deep Learning-Based Generation of Synthetic CT from MR Images for Craniosynostosis Planning

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    Craniosynostosis is a rare congenital defect caused by the premature fusion of one or more cranial sutures. This untimely cranial ossification hinders correct brain development. Its clinical diagnosis and treatment planning usually rely on Computed Tomography (CT), a potentially harmful imaging technique for young infants. It is with the intent of avoiding the use of ionizing radiation in this clinical pipeline that this work studies how feasible it is to resort to alternative non-detrimental imaging techniques such as Magnetic Resonance Imaging (MRI). We evaluate the performance of neural network generators trained on Generative Adversarial Networks in the MRI-to-CT translation task. We train nine generative models on 25 paired MR-CT medical scans, and validate and test their performance on 8 and 4 paired images, respectively. The results are promising both from qualitative and quantitative standpoints, particularly those of the models trained directly on 3D data. Results demonstrate that it is feasible to generate reliable and accurate synthetic CT scans from MR images with the proposed framework, opening up the possibility of harnessing the benefits of non-ionizing techniques to drive craniosynostosis diagnosis and treatment planning.CERMEP database has © Copyright CERMEP – Imagerie du vivant, www.cermep.fr and Hospices Civils de Lyon. All rights reserved. Research supported by projects PI122/00601 and AC20/00102 (Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III, Asociación Española Contra el Cáncer and European Regional Development Fund “Una manera de hacer Europa”), project PerPlanRT (under the frame of ERA PerMed), TED2021- 129392B-I00 and TED2021-132200B-I00 (MCIN/AEI/10.13039/501100011033 and European Union “NextGenerationEU”/PRTR)

    Single to Double Hump Transition in the Equilibrium Distribution Function of Relativistic Particles

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    We unveil a transition from single peaked to bimodal velocity distribution in a relativistic fluid under increasing temperature, in contrast with a non-relativistic gas, where only a monotonic broadening of the bell-shaped distribution is observed. Such transition results from the interplay between the raise in thermal energy and the constraint of maximum velocity imposed by the speed of light. We study the Bose-Einstein, the Fermi-Dirac, and the Maxwell-J\"uttner distributions, all exhibiting the same qualitative behavior. We characterize the nature of the transition in the framework of critical phenomena and show that it is either continuous or discontinuous, depending on the group velocity. We analyze the transition in one, two, and three dimensions, with special emphasis on two-dimensions, for which a possible experiment in graphene, based on the measurement of the Johnson-Nyquist noise, is proposed.Comment: 5 pages, 5 figure

    Tunable plasmonic resonance of gallium nanoparticles by thermal oxidation at low temperatures

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    This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after the 12 month embargo period provided that all the terms of the licence are adhered toThe effect of the oxidation of gallium nanoparticles (Ga NPs) on their plasmonic properties is investigated. Discrete dipole approximation has been used to study the wavelength of the out-of-plane localized surface plasmon resonance in hemispherical Ga NPs, deposited on silicon substrates, with oxide shell (Ga2O3) of different thickness. Thermal oxidation treatments, varying temperature and time, were carried out in order to increase experimentally the Ga2O3 shell thickness in the NPs. The optical, structural and chemical properties of the oxidized NPs have been studied by spectroscopic ellipsometry, scanning electron microscopy, grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy. A clear redshift of the peak wavelength is observed, barely affecting the intensity of the plasmon resonance. A controllable increase of the Ga2O3 thickness as a consequence of the thermal annealing is achieved. In addition, simulations together with ellipsometry results have been used to determine the oxidation rate, whose kinetics is governed by a logarithmic dependence. These results support the tunable properties of the plasmon resonance wavelength in Ga NPs by thermal oxidation at low temperatures without significant reduction of the plasmon resonance intensityThis research is supported by the MINECO (CTQ2014-53334-C2-2-R and MAT2016-80394-R) and Comunidad de Madrid (NANOAVANSENS ref. S2013/MIT-3029) projects. ARC acknowledges Ramón y Cajal program (under contract number RYC-2015-18047). FN acknowledges support from Marie Sklodowska-Curie grant agreement No 641899 from the European Union’s Horizon 2020 research and innovation programm

    Relativistic Klein-Gordon charge effects by information-theoretic measures

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    The charge spreading of ground and excited states of Klein-Gordon particles moving in a Coulomb potential is quantitatively analyzed by means of the ordinary moments and the Heisenberg measure as well as by use of the most relevant information-theoretic measures of global (Shannon entropic power) and local (Fisher's information) types. The dependence of these complementary quantities on the nuclear charge Z and the quantum numbers characterizing the physical states is carefully discussed. The comparison of the relativistic Klein-Gordon and non-relativistic Schrodinger values is made. The non-relativistic limits at large principal quantum number n and for small values of Z are also reached.Comment: Accepted in New Journal of Physic

    Analysis of breakfast in a population of school of 3rd cycle Primary, a resource training in Health Education

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    El desayuno es básico en el óptimo desarrollo en las etapas infantil y adolescente, asociándose a un mayor rendimiento físico e intelectual. A pesar de la gran importancia de un desayuno saludable, la falta de tiempo y los nuevos estilos de vida han afectado principalmente al hábito del desayuno completo, con una tendencia mayoritaria a realizar desayunos muy ligeros e incluso a llegar a eliminarlos. Nuestro objetivo fue iniciar el análisis del desayuno en una población escolar, alumnos de 3er Ciclo de Primaria de la Provincia de Badajoz. Para ello se recogió la información del Desayuno mediante Cuestionario-Recordatorio y análisis nutricional mediante Programa DIAL Los resultados iniciales indican que, en el ámbito urbano tan solo el 23,25 % de los escolares tomaron un desayuno saludable, dicho porcentaje se incrementa ligeramente para el ámbito rural, siendo de 39,13%. En conclusión se debe promocionar, en dicha población escolar, un proceso de enseñanza- aprendizaje significativo, de intervención educativa del Desayuno SaludableBreakfast is basic in the optimal development in the child and adolescent stages and is associated with increased physical and intellectual performance. Despite the great importance of a healthy breakfast, lack of time and changing lifestyles have affected mainly full breakfast habit, with a majority tendency to make very light breakfast and even get to remove them Our goal was to begin the analysis of the breakfast in a population Elementary school students in the province of Badajoz This information was collected by Questionnaire-Reminder Breakfast. And nutritional analysis by DIAL Program The results, initials, indicate that in urban areas as only 23.25% of the students took a healthy breakfast. And this percentage slightly increases for rural areas, being 39.13%. In conclusion it should be promoted in this school population, a process of teaching and learning meaningful educational intervention Healthy Breakfast- Diputación de Badajoz - Gobierno de Extremadura - Fondos FEDER - Universidad de ExtremadurapeerReviewe
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