Identification and quantification of cell gas evolution in rigid polyurethane foams by novel GCMS methodology

Producción CientíficaThis paper presents a new methodology based on gas chromatography-mass spectrometry (GCMS) in order to separate and quantify the gases presented inside the cells of rigid polyurethane (RPU) foams. To demonstrate this novel methodology, the gas composition along more than three years of aging is herein determined for two samples: a reference foam and foam with 1.5 wt% of talc. The GCMS method was applied, on one hand, for the accurate determination of C5H10 and CO2 cell gases used as blowing agents and, on the other hand, for N2 and O2 air gases that diffuse rapidly from the surrounding environment into foam cells. GCMS results showed that CO2 leaves foam after 2.5 month (from 21% to 0.03% for reference foam and from 17% to 0.03% for foam with 1.5% talc). C5H10 deviates during 3.5 months (from 28% up to 39% for reference foam and from 29% up to 36% for foam with talc), then it starts to leave the foam and after 3.5 year its content is 13% for reference and 10% for foam with talc. Air diffuses inside the cells faster for one year (from 51% up to 79% for reference and from 54% up to 81% for foam with talc) and then more slowly for 3.5 years (reaching 86% for reference and 90% for foam with talc). Thus, the fast and simple presented methodology provides valuable information to understand the long-term thermal conductivity of the RPU foams.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (grants MAT2015-69234-R and RTC-2016-5285-5)Junta de Castilla y Leon (grant VA275P18)Agencia austriaca para la promoción de la investigación (grant 850697

Movil-Izate Project: promoting physical activity in school through mobile apps

El objetivo del estudio era dar a conocer una propuesta práctica desarrollada en el contexto educativo para fomentar los niveles de actividad física (AF) extraescolar y, a su vez, analizar el grado de utilidad y satisfacción de los participantes con el programa. Para ello, se contó con un total de 1043 alumnos (M = 14.93; DT = .88) de 3º y 4º de ESO pertenecientes a 22 centros diferentes. La intervención realizada estaba centrada en cuatro pilares fundamentales: 1) un taller con alumnos, encaminado a concienciar a los adolescentes sobre la importancia de crear estilos de vida saludables; 2) un taller práctico en el que se explicaba el funcionamiento de una App móvil destinada al registro de la AF; 3) un concurso cooperativo, con el que se pretendía fomentar la práctica de AF de forma autónoma; y 4) un taller con padres/madres, con el fin de exponerles una serie de estrategias para fomentar en sus hijos/as la práctica de AF extraescolar. Tras la realización del programa, tanto los alumnos como los profesores completaron un cuestionario encaminado a valorar la percepción de la propuesta, comprobándose con ello la idoneidad de este tipo de iniciativas para fomentar la práctica de AF en la población adolescente.The aim of the study was to provide a practical proposal developed in an educational context to promote extracurricular physical activity (PA) and, in turn, analyze the degree of usefulness and participant satisfaction with the program. To this aim, a total of 1043 students (M = 14.93, SD = .88) in secondary 3 and 4 from 22 high schools participated in the study. The intervention was focused on four points: 1) a workshop with students, aiming to educate teens about the importance of adopting healthy lifestyles; 2) a workshop in which the operation of a mobile app designed to record the PA was explained; 3) a cooperative competition, intended to encourage the practice of PA autonomously; and 4) a workshop with fathers/mothers,in order to present a series of strategies to encourage their children to engage in regular PA. After completion of the program, both students and teachers completed a questionnaire aimed at assessing the perception of the proposal, and thus at demonstrating the suitability of these type of initiatives to encourage the practice of PA in the adolescent population.peerReviewe

Optimization, Stability, and Entropy in Endoreversible Heat Engines

[EN]The stability of endoreversible heat engines has been extensively studied in the literature. In this paper, an alternative dynamic equations system was obtained by using restitution forces that bring the system back to the stationary state. The departing point is the assumption that the system has a stationary fixed point, along with a Taylor expansion in the first order of the input/output heat fluxes, without further specifications regarding the properties of the working fluid or the heat device specifications. Specific cases of the Newton and the phenomenological heat transfer laws in a Carnot-like heat engine model were analyzed. It was shown that the evolution of the trajectories toward the stationary state have relevant consequences on the performance of the system. A major role was played by the symmetries/asymmetries of the conductance ratio shc of the heat transfer law associated with the input/output heat exchanges. Accordingly, threemain behaviorswere observed: (1) For small shc values, the thermodynamic trajectories evolved near the endoreversible limit, improving the efficiency and power output values with a decrease in entropy generation; (2) for large shc values, the thermodynamic trajectories evolved either near the Pareto front or near the endoreversible limit, and in both cases, they improved the efficiency and power values with a decrease in entropy generation; (3) for the symmetric case (shc = 1), the trajectories evolved either with increasing entropy generation tending toward the Pareto front or with a decrease in entropy generation tending toward the endoreversible limit. Moreover, it was shown that the total entropy generation can define a time scale for both the operation cycle time and the relaxation characteristic time.Junta de Castilla y León, Project No. SA017P1

Additive manufacturing of mode converters in Ku and Q bands by selective laser sintering: experience and results

In recent years, Additive Manufacturing (AM) has turned out as a disruptive technology [1]. Fast production, rapid prototyping or adaptability, are essential concepts in sectors such as automotive, aerospace, biotech, etc. [2], [3]. In microwave engineering, the main advantages of AM are the possibility to produce customized items and the complexity of the implemented geometries compared with other technologies such as Computer Numerical Control (CNC) machining, injection moulding, casting or Electrical Discharge Machining (EDM). Nowadays, AM technologies are focused on the development of the next generation of microwave and millimetrewave devices. Regarding high-frequency circuits, and more specifically in the case of waveguide technology devices, the impact has been very relevant [4]. The initial efforts have been focused on filters, couplers, feed components and antennas. However, in this work the experience and results with other sort of devices, i.e., the mode converters, will be exposed. These broadband devices without resonant behaviour and strong electromagnetic fields are especially well-suited to cope with the two main problems of AM, i.e., the manufacturing accuracy and the surface roughness. Two different mode converters have been designed and manufactured by means of Selective Laser Sintering technology using aluminium alloy powder. The first one is a TE10 rectangular mode to TM01 circular mode converter in Ku-band and the second one is a TE10 rectangular mode to TE01 circular mode flared-type converter in Q-band. The experimental results obtained in both cases will be presented in detail. In addition, the issues related to the orientation of the parts inside the building chamber and other undesirable effects such as spikes due to manufacturing asymmetries, will be shared with the scientific community

Frustración de las necesidades psicológicas, motivación y burnout en entrenadores : incidencia de la formación

El objetivo del estudio era analizar la incidencia de la formación (federativa y académica general) de los entrenadores sobre variables psicológicas motivacionales (frustración de las necesidades psicológicas básicas (NPB), autodeterminación), eficacia profesional y agotamiento emocional. Para ello, participaron 147 entrenadores de 26 deportes diferentes en categorías de iniciación. Los resultados demostraron que los entrenadores con titulación deportiva intermedia tenían una motivación más intrínseca que los no cualificados, mientras que los entrenadores con mayor titulación se sentían más eficaces y más agotados. Asimismo, los entrenadores con mayor titulación académica general obtuvieron menores niveles de frustración en las NPB de competencia y relaciones sociales. Por tanto, la cualificación de los entrenadores determina los niveles de frustración de las NPB, el grado de motivación y dos dimensiones del burnout, la eficacia profesional y el agotamiento emocional.The aim of this study was to examine coaches' training (federative and general academic) incidence on motivational psychological variables (frustration of the basic psychological needs (BPN), self determination, professional efficacy and emotional burnout). Thus, 147 coaches belonged to 26 different sports in training categories participated in the study. Results showed that coaches with medium sport qualification had a greater intrinsic motivation than those who were not qualified, whereas coaches with higher qualification showed more efficacy and burnout. Moreover, coaches with greater general academic degree had low levels of frustration in the BPN of competence and relatedness. Therefore, coaches' qualification determine their frustration of the BPN, level of motivation and two burnout dimensions, professional efficacy and emotional burnout.O objectivo deste estudo foi analisar a incidência da formação de treinadores (federativa e académica geral) nas variáveis psicológicas motivacionais (frustração das necessidades psicológicas básicas (NPB), autodeterminação, eficácia profissional e burnout emocional). Assim, participaram no estudo 147 treinadores dos escalões de formação de 26 modalidades desportivas diferentes. Os resultados mostraram que os treinadores com qualificação desportiva média tinham maior motivação intrínseca do que aqueles que não eram qualificados, enquanto os treinadores com maior qualificação apresentaram maior eficácia e burnout. Adicionalmente, treinadores com maior grau académico geral tinham baixos níveis de frustração das NPB de competência e relação. Como tal, a qualificação dos treinadores determina a frustração das suas NPB, o nível de motivação e duas dimensões de burnout, eficácia profissional e burnout emocional

Detección y desarrollo del talento deportivo: el estado del arte

Son muchos los deportistas jóvenes que presentan el potencial para poder obtener rendimientos elevados. Sin embargo, son muy pocos los que alcanzan un nivel internacional. Conseguir la excelencia en el deporte requiere grandes esfuerzos, recursos y tiempo. Cualquier pequeño avance, cualquier mínimo detalle que ayude a mejorar dicho proceso, que aumente las opciones de éxito de los distintos programas formativos, será excepcionalmente valorado por los entrenadores, deportistas y gestores. ¿Qué es lo que permite o provoca que un deportista si alcance los resultados esperados y otros no? ¿Qué factores favorecen el desarrollo del deportista? ¿Cómo diseñar el proceso de detección y desarrollo del talento?. La presente conferencia tiene como objetivo presentar el estado del arte en la detección y desarrollo del talento, ofreciendo al lector una visión general de cuales han sido las principales formas de afrontar este proceso, al mismo tiempo que se detallan los principales conceptos y factores que, hoy en día, se conocen como favorecedores o limitantes del desarrollo deportivo. Por ello, se ha dividido fundamentalmente en dos partes. La primera de ellas, hace referencia a las investigaciones realizadas en este ámbito, tanto desde el punto de vista cuantitativo como cualitativo. Se presentan las principales conclusiones de ambas líneas de investigación, de tal manera, que el lector pueda tener una idea general de cómo es el proceso formativo del deportista. La segunda parte de la conferencia presenta, dada las limitaciones existentes en las investigaciones realizadas hasta la fecha, nuevas alternativas al proceso de identificación y desarrollo del talento

Thermodynamic optimization subsumed in stability phenomena

[EN]In the present paper the possibility of an energetic self-optimization as a consequence of thermodynamic stability is addressed. This feature is analyzed in a low dissipation refrigerator working in an optimized trade-off regime (the so-called Omega function). The relaxation after a perturbation around the stable point indicates that stability is linked to trajectories in which the thermodynamic performance is improved. Furthermore, a limited control over the system is analyzed through consecutive external random perturbations. The statistics over many cycles corroborates the preference for a better thermodynamic performance. Endoreversible and irreversible behaviors play a relevant role in the relaxation trajectories (as well as in the statistical performance of many cycles experiencing random perturbations). A multi-objective optimization reveals that the well-known endoreversible limit works as an attractor of the system evolution coinciding with the Pareto front, which represents the best energetic compromise among efficiency, entropy generation, cooling power, input power and the Omega function. Meanwhile, near the stable state, performance and stability are dominated by an irreversible behavior

Parotid gland solitary fibrous tumor with mandibular bone destruction and aggressive behavior

Introduction: Solitary fibrous tumor is associated with serosal surfaces. Location in the salivary glands is extremely unusual. Extrathoracic tumors have an excellent prognosis associated with their benign clinical behavior. We report an aggressive and recurrent case of this tumor. We review the clinical presentation, inmunohistochemical profiles and therapeutic approaches. Case Report: A 73-years-old woman presented a mass in her right parotid gland. She had a past history of right superficial parotidectomy due to a neurilemoma. FNAB and magnetic resonance were non-specific. After a tumor resection, microscopic findings were spindled tumor cells with reactivity to CD34, bcl-2 and CD99 and the tumor was diagnosed as Solitary Fibrous Tumor. The patient suffered two recurrences and the tumor had a histological aggressive behavior and a destruction of the cortical bone of the mandible adjacent to the mass. A marginal mandi - bulectomy with an alveolar inferior nerve lateralization was performed. Conclusions: Solitary fibrous tumor is a very rare tumor. Usually, they are benign, but occasionally they can be aggressive. Complete resection is the most important prognostic factor and no evidence supports the efficacy of any therapy different to surgery. Due to the unknown prognosis and to the small number of cases reported, a long-term follow-up is guaranteed

Influence of bicarbonate, other anions and carbon dioxide in the activity of Pd-Cu catalysts for nitrate reduction in drinking water

Synthetic and commercial drinking waters with different composition were studied as reaction media to study the influence of salts in NO3- catalytic reduction using a Pd-Cu catalyst supported on a carbon black. As a general trend, a decrease in NO3- conversion and an increase in NH4+ selectivity were observed for high HCO3- concentration media in mixed salts waters. Literature has commonly ascribed HCO3- effect to competitive adsorption with NO3-. However, in the current work, the mechanism for effect HCO3- is reconsidered basis on HCO2- formation during NO3- catalytic reduction, here reported for the first time. HCO2- formation indicates that hydrogenation of HCO3- occurs in addition to adsorption. Likewise, decomposition of HCO2- on the catalysts surface releases hydrogen leading to increased spill-over and relevant hydrogenation of NO3- to NH4+. The presence of SO42-, Cl- reduces NH4+ selectivity due to competition for active sites and lower HCO2- generation. Furthermore, it was observed that the use of CO2 as buffer also contribute to the hydrogenation of NO3- to NH4+ through HCO2- routeThe authors greatly appreciate the support from Spanish Agencia Estatal de Investigacion ´ RTI2018-098431-B-I00 (MCIU/AEI/FEDER, UE). Dydia Tanisha Gonzalez ´ thanks the Regional Government of Madrid a research grant (PEJ-2020-AI/AMB-17551

Trabajo Fin de Máster

El Trabajo Fin de Máster constituye una memoria integradora de todos los saberes y competencias que se han obtenido cursando las diferentes asignaturas y realizando los dos periodos de prácticas. El objetivo de este trabajo es realizar una reflexión de la profesión docente a partir de la explicación del modo en que han contribuido a la adquisición de las mencionadas competencias tanto las materias cursadas como la experiencia de prácticas en el centro de enseñanza. Para profundizar en las importantes aportaciones profesionales que nos ha otorgado el máster la reflexión también incluye el comentario crítico de los dos proyectos que, a mi juicio, han tenido mayor repercusión en mi formación como docente. Se completa con algunas propuestas de mejora en el campo docente y educativo que a lo largo de estos meses he ido detectando