281 research outputs found

    Biomecánica y mecanismo de producción del traumatismo cráneo-encefálico en el peatón atropellado. Evaluación de la normativa actual en la automoción

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    Introducción Los atropellos son una de las principales causas de muerte entre los accidentes de tráfico. Recientemente, ha aumentado el estudio de los atropellos, principalmente debido a la aplicación de la normativa europea y japonesa en protección de peatones. Esta investigación presenta un análisis del traumatismo cráneo-encefálico del peatón atropellado, asociándolo con la estructura del vehículo responsable de la lesión, su mecanismo de daño y comparando el resultado con la normativa existente. Métodos La metodología empleada ha consistido en un estudio epidemiológico descriptivo y transversal, mediante el estudio de datos de peatones atropellados recogidos en la base de datos americana (PCDS) que analiza a un total de 552 peatones atropellados y un total de 4.500 lesiones documentadas. Resultados De acuerdo con este estudio, el capó es el causante del 15,1% de las lesiones de la cabeza del peatón, mientras que el parabrisas es responsable de 41,8% de todas las lesiones. En el caso de los vehículos tipo utilitario la ubicación del impacto de la cabeza se produce por encima de lo que se espera en la regulación actual y, por lo tanto, no se aplican las contramedidas necesarias. De todas las lesiones en la cabeza sufridas por los peatones solo el 20% tiene la aceleración lineal como mecanismo de lesión, el 40% de las lesiones se deben a la aceleración rotacional. Conclusiones En esta investigación se pone de manifiesto la importancia de la aceleración rotacional como mecanismo de daño en la cabeza del peatón atropellado. En la normativa actual solo la aceleración lineal está contemplada en la formulación del principal criterio biomecánico utilizado para predecir el traumatismo cráneo-encefálico.Peer ReviewedPostprint (author's final draft

    Salt tectonics vs. inversion tectonics: The anticlines of the western Maestrazgo revisited (eastern Iberian Chain, Spain)

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    Many works in the last decades underline the role of evaporites, not just as a conditioning factor but as the engine for subsidence and eventually basin inversion. The western Mediterranean alpine ranges are being investigated in this regard because of the presence of discontinuous units of Permian to Triassic evaporites, deposited in the western Tethys basins. This work presents a thorough analysis of two particular structures (Cañada Vellida and Miravete anticlines) in the intraplate Maestrazgo basin (eastern Iberian Chain, Spain) in which evidence to support their reinterpretation as salt-driven structures have been recently reported. Our analysis includes (i) a comprehensive stratigraphic and structural study of the folds along their entire trace, (ii) the compilation of thickness and distribution of evaporite–bearing and supraevaporite units, paying special attention to changes in the thickness of units in relation to anticlines, and (iii) the study of fault patterns, sometimes in relation to the mechanical stratigraphy. All three aspects are also documented and discussed on a regional scale. The new data and interpretations reported here reinforce the extensional origin of the Late Jurassic–Early Cretaceous basins, and the role of regional extensional tectonics as the responsible for the development of first-order syn-sedimentary normal fault zones driving the formation and evolution of sub-basins. These basins were subsequently inverted and deformed, including the formation of complex, box-geometry anticlines that, in their turn, controlled deposition in Cenozoic basins. The review of the arguments that support the alternative of salt tectonics for the origin of such anticlines has allowed us to delve into the sedimentary and tectonic evolution of the inverted extensional basins and to propose a specific model for the development of these faulted anticlines. The role of salt levels and other interlayered detachments in the structuring of sedimentary basins and their inversion is also pondered. The observations in the eastern Iberian Chain reported here have implications to assess ongoing reinterpretations in terms of salt tectonics in other alpine basins and ranges of the western Mediterranean

    Injury pattern in lethal motorbikes-pedestrian collisions, in the area of Barcelona, Spain

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    Introduction: There are several studies about M1 type vehicle-pedestrian collision injury pattern, and based on them, there has been several changes in automobiles for pedestrian protection. However, the lack of sufficient studies about injury pattern in motorbikes-pedestrian collisions leads to a lack of optimization design of these vehicles. The objective of this research is to study the injury pattern of pedestrians involved in collisions with motorized two-wheeled vehicles. Methods: A retrospective descriptive study of pedestrian’s deaths after collisions with motorcycles in an urban area, like Barcelona was performed. The cases were collected from the Forensic Pathology Service database of the Institute of Legal Medicine of Catalonia. The selected cases were categorized as pedestrian-motorcycle collision, between January 1st 2006 and December 31th 2014. Data were collected from the autopsy, medical, and police report. The collected information was then analyzed using Microsoft Excel statistical functions. Results: Traumatic Brain Injury is the main cause of death in pedestrian hit by motorized two-wheeled vehicles (62.85%). The most frequent injury was the subarachnoid hemorrhage, in 71.4% of cases, followed by cerebral contusions and skull base fractures (65.7%). By contrast, pelvic fractures and tibia fractures only appeared in 28.6%. Conclusions: The study characterizes the injury pattern of pedestrians involved in a collision with motorized two-wheeled vehicles in an urban area, like Barcelona, which has been found to be different from other vehicle-pedestrian collisions, with a higher incidence of brain injuries and minor frequency of lower extremities fractures in pelvis, tibia and fibula.Peer ReviewedPostprint (published version

    Effect of Deficit Irrigation on the Productive Response of Drip-irrigated Onion (Allium cepa L.) in Mediterranean Conditions

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    [EN] Water is an essential resource for food production, and agriculture consumes close to 69% of total freshwater use. Water shortage is becoming critical in arid and semiarid areas worldwide; therefore, it is vital to use water efficiently. The objective of this research was to evaluate the response of onion growth, plant water status, bulb yield, irrigation water use efficiency and bulb quality using three continued deficit strategies, applying 100, 75, and 50% of the irrigation water requirements during three seasons. The yield response factor was 0.71, indicating that in the analysed conditions the crop was tolerant to a water deficit. Compared to full irrigation, deficit irrigation with 75% of the irrigation water requirements resulted in a low yield and profit reduction for the growers (10.3% and 10.9%, respectively), but also important water savings (26.6%), improving both the irrigation water use efficiency and water use efficiency. However, onion exposure to severe water deficits at 50% of the irrigation water requirements drastically reduced plant growth and bulb yield and growers' profits, although it did increase their soluble solid content. Irrigating at 75% of the irrigation water requirements could be an actionable strategy for onion production under water-limited conditions.Abdelkhalik, A.; Pascual-Seva, N.; Nájera, I.; Domene, MA.; Baixauli Soria, C.; Pascual España, B. (2019). Effect of Deficit Irrigation on the Productive Response of Drip-irrigated Onion (Allium cepa L.) in Mediterranean Conditions. Horticulture Journal. 88(4):488-498. https://doi.org/10.2503/hortj.UTD-081S48849888

    Coordinated Control Of Mobile Robots Based On Artificial Vision

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    This work presents a control strategy for coordination of multiple robots based on artificial vision to measure the relative posture between them, in order to reach and maintain a specified formation. Given a leader robot that moves about an unknown trajectory with unknown velocity, a controller is designed to maintain the robots following the leader at a certain distance behind, by using visual information about the position of the leader robot. The control system is proved to be asymptotically stable at the equilibrium point, which corresponds to the accomplishment of the navigation objective. Experimental results with two robots, a leader and a follower, are included to show the performance of the vision-based control system

    Ceratium furcoides (Levander) Langhans in reservoirs at the Ebro watershed, Spain and Sao Paulo state, Brazil

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    This study compares the morphological characteristics of the dinoflagellate Ceratium furcoides from three Ebro basin reservoirs (Spain) and from six reservoirs at São Paulo state (Brazil) with the aim to identify the distinct morphotypes of Ceratium furcoides in Spain and Brazil. We studied the physical and chemical variables to determine the trophic state of each reservoir. Unlike Ceratium hirundinella, Ceratium furcoides is not a frequent species within the plankton community at Ebro Basin reservoirs, however, this species has been responsible of one monospecific bloom at El Val reservoir. Nevertheless, both Ceratium species are considered invasive in South America. Ceratium furcoides has displaced C. hirundinella at São Paulo state reservoirs, reaching high densities, to the extent of forming monospecific blooms. Morphometric analysis was performed by optic and electronic microscopy (DIC and SEM respectively). The analysis shows significant differences in: i) total cell length, ii) horns length and iii) presence or absence of a fourth horn. While the microscopic study allows differentiating morphotypes according to the reservoir typology, a deeper study using molecular genetic techniques on the different populations of C. furcoides would allow to know better the relationship between the dinoflagellate dynamics and the reservoirs trophic states

    Fluid structural analysis of urine flow in a stented ureter

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    Many urologists are currently studying new designs of ureteral stents to improve the quality of their operations and the subsequent recovery of the patient. In order to help during this design process, many computational models have been developed to simulate the behaviour of different biological tissues and provide a realistic computational environment to evaluate the stents. However, due to the high complexity of the involved tissues, they usually introduce simplifications to make these models less computationally demanding. In this study, the interaction between urine flow and a double-J stented ureter with a simplified geometry has been analysed.The Fluid-Structure Interaction (FSI) of urine and the ureteral wall was studied using three models for the solid domain: Mooney-Rivlin, Yeoh, and Ogden. The ureter was assumed to be quasi-incompressible and isotropic. Data obtained in previous studies fromex vivo and in vivo mechanical characterization of different ureters were used to fit thementioned models.The results show that the interaction between the stented ureter and urine is negligible. Therefore, we can conclude that this type of models does not need to include the FSI and could be solved quite accurately assuming that the ureter is a rigid body and, thus, using the more simple Computational Fluid Dynamics (CFD) approach

    Control adaptable PID e identificación neuronal de un Vehículo Aéreo Autónomo (UAV) cuatrirotor usando filtro de Kalman extendido

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    En este artículo se presenta un nuevo algoritmo de seguimiento de trayectorias para un vehículo aéreo de cuatro rotores (cuatrirotor). El controlador PID propuesto se desarrolla siguiendo una técnica neuronal adaptable y su estabilidad es verificada por la teoría de Lyapunov aplicada en tiempo discreto. Además, se presenta la identificación neuronal del Vehículo aéreo autónomo (UAV, Unmanned Aerial Vehicles) de modelo dinámico, además es utilizado un filtro de Kalman extendido (EKF Extended Kalman Filter) para poder filtrar las señales del vehículo aéreo que están contaminadas por ruidos de medición y que pueden afectar a las señales intervinientes en la identificación. A continuación, los errores de salida son retropropagados a través de la red neuronal que fue identificada para ajustar las ganancias PID para reducir los errores de control. Finalmente, los resultados experimentales se presentan utilizando un vehículo aéreo cuatrirotor, y además se realizó una comparación de la propuesta presentada con un controlador PID clásico de ganancia fija.Publicado en: Mecánica Computacional vol. XXXV no 29Facultad de Ingenierí

    The association of CAPN1 316 marker genotypes with growth and meat quality traits of steers finished on pasture

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    The objective of this paper was to determine the association of a SNP in the μ-calpain gene at position 316 with growth and quality of meat traits of steers grown on pasture. Fifty-nine Brangus and 20 Angus steers were genotyped for CAPN1 316. Warner Bratzler shear force was measured in l. lumborum samples after a 7-day aging period. A multivariate analysis of variance was performed, including shear force (WBSF), final weight (FW), average daily gain (ADG), backfat thickness (BFT), average monthly fat thickness gain (AMFTG), rib-eye area (REA), and beef rib-eye depth (RED) as dependent variables. The CAPN1 316 genotype was statistically significant. Univariate analyses were done with these variables. The marker genotype was statistically significant (p < 0.05) for WBSF (kg: CC: 4.41 ± 0.57; CG: 5.58 ± 0.20; GG: 6.29 ± 0.18), FW (kg: CC: 360.23 ± 14.71; CG: 381.34 ± 5.26; GG: 399.23 ± 4.68), and ADG (kg/d: CC: 0.675 ± 0.046; CG: 0.705 ± 0.016; GG: 0.765 ± 0.014) Shear force, final weight and average daily gain were significantly different according to the CAPN1 316 marker genotypes. The marker genotype was statistically significant in the multivariate analysis (p = 0.001). The first characteristic root explained 89% of the differences among genotypes. WBSF, FW and ADG were the most important traits in the first vector, indicating that animals with the marker genotype for lowest WBSF also have the lowest FW and ADG
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