2,898 research outputs found

    Improvement of the Quality Control Plan in the reception of waste glass. Application in Verallia

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    The objective of the work is the improvement of the current Quality Control Plan in the reception of recycling material (cullet) in a glass factory, to check the conditions of the requirement specifications and, in particular, to reduce the presence of critical contaminants (ceramics, stone, porcelain,…) in the input materia

    Body composition and somatotype in professional men's handball according to playing positions

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    Se realizó un estudio descriptivo transversal en 19 jugadores profesionales del Club Balonmano Valladolid. Las mediciones antropométricas fueron realizadas según el protocolo estándar. Se estimaron la masa grasa y ósea, se calculó el somatotipo y se analizaron las diferencias entre las variables en función de la posición. Como resultados, se obtuvo que los pivotes fueron los jugadores más pesados (con mayor porcentaje de masa grasa); los extremos, los más ligeros y los laterales, junto con los pivotes, los más altos. No se observaron diferencias en el IMC en los grupos. En la somatocarta los centrales y laterales se situaron en la zona central; los extremos y los pivotes en la endomorfa-mesomorfa y los porteros en la ecto-endomorfa. Así se evidenció que las variables antropométricas, los datos de composición corporal y la somatocarta de los deportistas confirman las características morfológicas básicas de los jugadores para la posición para la que son más aptosA cross-sectional descriptive study was accomplished in 19 professional players from Valladolid Handball Club. Anthropometric measurements were performed according to standard protocol. Body fat and bone mass were estimated, and the somatotype was calculated. As results, the line players were significantly the heaviest players; the wings were lightest and the backs, with the line players, the tallest. Nevertheless, no significant differences in BMI were observed. Regarding the body composition, the line players showed the highest values of fat-mass. No differences in BMI were observed in the groups. With respect to the somatochart, the center backs and backs were in the central area; wings and line players showed an endomorph-mesomorph development, and goalkeepers were in the ectoendomorph area. As conclusions, anthropometric variables, body composition data and the somatochart of the athletes evaluated confirm the basic morphological characteristics of the players for the position for which they are best suite

    Spatial behavior of acid mine drainage in a peculiar stream : physical-chemical evolution from the source until the temporarlly receptor in the Iberian Pyrite Belt

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    Publicado em "Proceedings of the Energy and Environment Knowledge Week 2014 (E2KW2014), ISBN 978-84-697-1162-0"The Iberian Pyrite Belt is a vast concentration of massive sulphide, located in the SW of the Iberian Peninsula. Historically, this area has undergone an intense mining activity, which has left a huge amount of mining facilities and unrestored waste dumps. Mineral-water interaction in the waste dumps is responsible for the generation of acid mine drainage (AMD), causing a strong impact in the water systems. The AMD occurs when the sulfide minerals are in the presence of atmospheric oxygen and humidity, suffering oxidation reactions. As a consequence, metals and acidity are mobilized into the receiving watercourses. Such conditions have created a unique scenario in the world by the extreme degradation that characterizes the network of channels and streams in the IPB. In this context, widely described in the scientific literature, the present study aims to monitoring a singular channel affected by AMD (Campanario stream), from its origin (in the waste dump) to its confluence with an unpolluted stream. Such monitoring procedure will allow characterizing the physicochemical evolution and the mineral-water processes that regulate it

    Four abandoned mines, one acid mine drainage affected river and an unsolved issue for a water supply reservoir

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    Publicado em "Proceedings of the Energy and Environment Knowledge Week 2014(E2KW2014)". ISBN 978-84-697-1162-

    3D 360° surface morphometric analysis of pounding stone tools used by Hadza foragers of Tanzania: A new methodological approach for studying percussive stone artefacts

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    Surface morphometry comprises a relevant set of techniques that provide objective tools to identify, map, and understand use wear patterns in stone tools. Thus far, these techniques have been applied mainly to 2D or 2.5D data, but their application to 3D 360° data is promising and still underdeveloped. Here, we apply new 3D techniques to calculate morphometric variables and to analyse surficial features and changes in pounding stone tools used for baobab processing among Hadza foragers of Tanzania. Baobab pounding stones were collected after use by Hadza foragers for processing the plant food and then 3D point clouds were acquired from laser scanners and SfM photogrammetry. Morphometry was conducted directly on 3D point clouds to avoid time-consuming and surface modifications related to more complex 3D data, such as meshing. Several morphometric variables were computed for the complete pieces (360° sphere) providing fast and accurate data to identify the detailed morphometric features of the artefacts. Additionally, stone surface changes due to baobab processing were measured by comparing the stone surface before and after use, thus enabling calculation of spatial abrasion patterns. Data were interpreted using multivariate exploratory statistical analysis. Differences in the effect of processing on surface morphology are likely explained by variations in raw source material and use. Results suggest that the traces produced by baobab processing on stone tools should be detectable in the archaeological record

    Incremental SVM of controlled full-bridge rectifiers to allow IEC 61000-3-2 enforcement in power grid connection of modern elevator systems

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    The purpose of this paper is the study of different power converters and control techniques to allow power grid connection of modern vertical operation systems, verifying IEC 61000-3-2. We focus on the harmonic current analysis produced by the industrial standard AC/DC/3-phase AC machines system. Different AC/DC converters and control techniques have been compared to determine the one that minimizes low frequency harmonic current production. An incremental space vector modulator to regulate power grid current flow in electrical reference frame with a full-bridge controlled rectifier has been proven as the best power grid connection system. A general purpose test rig has been designed to evaluate the different power grid interface policies. Experimental results have been provided to show the effectiveness of the method

    Gz mediates the long-lasting desensitization of brain CB1 receptors and is essential for cross-tolerance with morphine

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    Abstract Background Although the systemic administration of cannabinoids produces antinociception, their chronic use leads to analgesic tolerance as well as cross-tolerance to morphine. These effects are mediated by cannabinoids binding to peripheral, spinal and supraspinal CB1 and CB2 receptors, making it difficult to determine the relevance of each receptor type to these phenomena. However, in the brain, the CB1 receptors (CB1Rs) are expressed at high levels in neurons, whereas the expression of CB2Rs is marginal. Thus, CB1Rs mediate the effects of smoked cannabis and are also implicated in emotional behaviors. We have analyzed the production of supraspinal analgesia and the development of tolerance at CB1Rs by the direct injection of a series of cannabinoids into the brain. The influence of the activation of CB1Rs on supraspinal analgesia evoked by morphine was also evaluated. Results Intracerebroventricular (icv) administration of cannabinoid receptor agonists, WIN55,212-2, ACEA or methanandamide, generated a dose-dependent analgesia. Notably, a single administration of these compounds brought about profound analgesic tolerance that lasted for more than 14 days. This decrease in the effect of cannabinoid receptor agonists was not mediated by depletion of CB1Rs or the loss of regulated G proteins, but, nevertheless, it was accompanied by reduced morphine analgesia. On the other hand, acute morphine administration produced tolerance that lasted only 3 days and did not affect the CB1R. We found that both neural mu-opioid receptors (MORs) and CB1Rs interact with the HINT1-RGSZ module, thereby regulating pertussis toxin-insensitive Gz proteins. In mice with reduced levels of these Gz proteins, the CB1R agonists produced no such desensitization or morphine cross-tolerance. On the other hand, experimental enhancement of Gz signaling enabled an acute icv administration of morphine to produce a long-lasting tolerance at MORs that persisted for more than 2 weeks, and it also impaired the analgesic effects of cannabinoids. Conclusion In the brain, cannabinoids can produce analgesic tolerance that is not associated with the loss of surface CB1Rs or their uncoupling from regulated transduction. Neural specific Gz proteins are essential mediators of the analgesic effects of supraspinal CB1R agonists and morphine. These Gz proteins are also responsible for the long-term analgesic tolerance produced by single doses of these agonists, as well as for the cross-tolerance between CB1Rs and MORs.</p

    Experimental assessment of anomalous low-frequency noise increase at the onset of Gunn oscillations in InGaAs planar diodes

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    In this work, the presence of anomalous low-frequency fluctuations during the initiation of higher frequency oscillations in InGaAs-based Gunn planar diodes has been evidenced and investigated. Accurate measurements showing the evolution of the power spectral density of the device with respect to the applied voltage have been carried out. Such spectra have been obtained in the wide frequency range between 10MHz and 43.5 GHz, simultaneously covering both the low-frequency noise and the fundamental oscillation peak at some tens of GHz. This provides valuable information to better understand how these fluctuations appear and how these are distributed in frequency. For much higher frequency operation, such understanding can be utilized as a simple tool to predict the presence of Gunn oscillations without requiring a direct detection
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