2,213 research outputs found

    Anti-inflammatory activity of

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    The anti-inflammatory activity of the chloroform, methanol and aqueous extracts of Wigandia urens and Acalypha alopecuroides were investigated on carrageenan-induced paw edema at doses of 400 mg/kg. The three extracts of W. urens, and the aqueous extract of A. alopecuroides caused significantinhibition of the edema (58.1±6.5% and 63.5±5.4%, respectively). Indomethacin was used as positive control (8 mg/kg), and inhibited edema by 66.3±5.2%. The methanol extract of W. urens and the aqueous extract of A. alopecuroides, at doses of 200 mg/kg, inhibited pellet implantation-induced granuloma formation by 69.4±6.5 and 70.6±6.6%, respectively. These levels of inhibition are higher than those exhibited by naproxen at doses of 50 mg/kg (46.1±7.1%). Both extracts showed activity on adjuvantinduced arthritis in rats, with the best effect being observed after 96 h (82.2±4.6 and 80.6±7.3%, respectively)

    Force Control Improvement in Collaborative Robots through Theory Analysis and Experimental Endorsement

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    [EN] Due to the elasticity of their joints, collaborative robots are seldom used in applications with force control. Besides, the industrial robot controllers are closed and do not allow the user to access the motor torques and other parameters, hindering the possibility of carrying out a customized control. A good alternative to achieve a custom force control is sending the output of the force regulator to the robot controller through motion commands (inner/outer loop control). There are different types of motion commands (e.g., position or velocity). They may be implemented in different ways (Jacobian inverse vs. Jacobian transpose), but this information is usually not available for the user. This article is dedicated to the analysis of the effect of different inner loops and their combination with several external controllers. Two of the most determinant factors found are the type of the inner loop and the stiffness matrix. The theoretical deductions have been experimentally verified on a collaborative robot UR3, allowing us to choose the best behaviour in a polishing operation according to pre-established criteria.The authors are grateful for the financial support of the Spanish Ministry of Economy and European Union, grant DPI2016-81002-R (AEI/FEDER, UE), to the research work here published. Rodrigo Perez-Ubeda is grateful to the Ph.D. Grant CONICYT PFCHA/DOCTORADO BECAS CHILE/2017-72180157.Pérez-Ubeda, R.; Zotovic Stanisic, R.; Gutiérrez, SC. (2020). Force Control Improvement in Collaborative Robots through Theory Analysis and Experimental Endorsement. Applied Sciences. 10(12):1-24. https://doi.org/10.3390/app10124329S1241012Top Trends Robotics 2020—International Federation of Robotics https://ifr.org/ifr-press-releases/news/top-trends-robotics-2020Gaz, C., Magrini, E., & De Luca, A. (2018). A model-based residual approach for human-robot collaboration during manual polishing operations. Mechatronics, 55, 234-247. doi:10.1016/j.mechatronics.2018.02.014Iglesias, I., Sebastián, M. A., & Ares, J. E. (2015). Overview of the State of Robotic Machining: Current Situation and Future Potential. Procedia Engineering, 132, 911-917. doi:10.1016/j.proeng.2015.12.577Perez-Ubeda, R., Gutierrez, S. C., Zotovic, R., & Lluch-Cerezo, J. (2019). Study of the application of a collaborative robot for machining tasks. Procedia Manufacturing, 41, 867-874. doi:10.1016/j.promfg.2019.10.009Spong, M. W. (1989). On the force control problem for flexible joint manipulators. IEEE Transactions on Automatic Control, 34(1), 107-111. doi:10.1109/9.8661Ren, T., Dong, Y., Wu, D., & Chen, K. (2019). Impedance control of collaborative robots based on joint torque servo with active disturbance rejection. Industrial Robot: the international journal of robotics research and application, 46(4), 518-528. doi:10.1108/ir-06-2018-0130Ajoudani, A., Tsagarakis, N. G., & Bicchi, A. (2017). Choosing Poses for Force and Stiffness Control. IEEE Transactions on Robotics, 33(6), 1483-1490. doi:10.1109/tro.2017.2708087Magrini, E., & De Luca, A. (2016). Hybrid force/velocity control for physical human-robot collaboration tasks. 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS). doi:10.1109/iros.2016.7759151Ahmad, S. (1993). Constrained motion (force/position) control of flexible joint robots. IEEE Transactions on Systems, Man, and Cybernetics, 23(2), 374-381. doi:10.1109/21.229451Calanca, A., & Fiorini, P. (2018). Understanding Environment-Adaptive Force Control of Series Elastic Actuators. IEEE/ASME Transactions on Mechatronics, 23(1), 413-423. doi:10.1109/tmech.2018.2790350Oh, S., & Kong, K. (2017). High-Precision Robust Force Control of a Series Elastic Actuator. IEEE/ASME Transactions on Mechatronics, 22(1), 71-80. doi:10.1109/tmech.2016.2614503Yin, H., Li, S., & Wang, H. (2016). Sliding mode position/force control for motion synchronization of a flexible-joint manipulator system with time delay. 2016 35th Chinese Control Conference (CCC). doi:10.1109/chicc.2016.7554329Ma, Z., Hong, G.-S., Ang, M. H., Poo, A.-N., & Lin, W. (2018). A Force Control Method with Positive Feedback for Industrial Finishing Applications. 2018 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM). doi:10.1109/aim.2018.8452689Huang, L., Ge, S. S., & Lee, T. H. (2006). Position/force control of uncertain constrained flexible joint robots. Mechatronics, 16(2), 111-120. doi:10.1016/j.mechatronics.2005.10.002Chiaverini, S., Siciliano, B., & Villani, L. (1999). A survey of robot interaction control schemes with experimental comparison. IEEE/ASME Transactions on Mechatronics, 4(3), 273-285. doi:10.1109/3516.789685Winkler, A., & Suchy, J. (2016). Explicit and implicit force control of an industrial manipulator — An experimental summary. 2016 21st International Conference on Methods and Models in Automation and Robotics (MMAR). doi:10.1109/mmar.2016.7575081Neranon, P., & Bicker, R. (2016). Force/position control of a robot manipulator for human-robot interaction. Thermal Science, 20(suppl. 2), 537-548. doi:10.2298/tsci151005036nChen, S., Zhang, T., & Zou, Y. (2017). Fuzzy-Sliding Mode Force Control Research on Robotic Machining. Journal of Robotics, 2017, 1-8. doi:10.1155/2017/8128479Lin, H.-I., & Dubey, V. (2018). Design of an Adaptive Force Controlled Robotic Polishing System Using Adaptive Fuzzy-PID. Advances in Intelligent Systems and Computing, 825-836. doi:10.1007/978-3-030-01370-7_64Perez-Vidal, C., Gracia, L., Sanchez-Caballero, S., Solanes, J. E., Saccon, A., & Tornero, J. (2019). Design of a polishing tool for collaborative robotics using minimum viable product approach. International Journal of Computer Integrated Manufacturing, 32(9), 848-857. doi:10.1080/0951192x.2019.1637026Chen, F., Zhao, H., Li, D., Chen, L., Tan, C., & Ding, H. (2019). Contact force control and vibration suppression in robotic polishing with a smart end effector. Robotics and Computer-Integrated Manufacturing, 57, 391-403. doi:10.1016/j.rcim.2018.12.019Mohammad, A. E. K., Hong, J., & Wang, D. (2018). Design of a force-controlled end-effector with low-inertia effect for robotic polishing using macro-mini robot approach. Robotics and Computer-Integrated Manufacturing, 49, 54-65. doi:10.1016/j.rcim.2017.05.011Xiao, C., Wang, Q., Zhou, X., Xu, Z., Lao, X., & Chen, Y. (2019). Hybrid Force/Position Control Strategy for Electromagnetic based Robotic Polishing Systems. 2019 Chinese Control Conference (CCC). doi:10.23919/chicc.2019.8865183Li, J., Zhang, T., Liu, X., Guan, Y., & Wang, D. (2018). A Survey of Robotic Polishing. 2018 IEEE International Conference on Robotics and Biomimetics (ROBIO). doi:10.1109/robio.2018.8664890Zollo, L., Siciliano, B., De Luca, A., Guglielmelli, E., & Dario, P. (2004). Compliance Control for an Anthropomorphic Robot with Elastic Joints: Theory and Experiments. Journal of Dynamic Systems, Measurement, and Control, 127(3), 321-328. doi:10.1115/1.1978911Han, D., Duan, X., Li, M., Cui, T., Ma, A., & Ma, X. (2017). Interaction Control for Manipulator with compliant end-effector based on hybrid position-force control. 2017 IEEE International Conference on Mechatronics and Automation (ICMA). doi:10.1109/icma.2017.8015929Schindlbeck, C., & Haddadin, S. (2015). Unified passivity-based Cartesian force/impedance control for rigid and flexible joint robots via task-energy tanks. 2015 IEEE International Conference on Robotics and Automation (ICRA). doi:10.1109/icra.2015.7139036Zotovic Stanisic, R., & Valera Fernández, Á. (2009). Simultaneous velocity, impact and force control. Robotica, 27(7), 1039-1048. doi:10.1017/s0263574709005451Volpe, R., & Khosla, P. (1993). A theoretical and experimental investigation of explicit force control strategies for manipulators. IEEE Transactions on Automatic Control, 38(11), 1634-1650. doi:10.1109/9.262033Zeng, G., & Hemami, A. (1997). An overview of robot force control. Robotica, 15(5), 473-482. doi:10.1017/s026357479700057xSalisbury, J. (1980). Active stiffness control of a manipulator in cartesian coordinates. 1980 19th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes. doi:10.1109/cdc.1980.272026Chen, S.-F., & Kao, I. (2000). Conservative Congruence Transformation for Joint and Cartesian Stiffness Matrices of Robotic Hands and Fingers. The International Journal of Robotics Research, 19(9), 835-847. doi:10.1177/02783640022067201Institute of Robotics and Mechatronics DLR Light Weight Robot III https://www.dlr.de/rm/en/desktopdefault.aspx/tabid-12464/#gallery/2916

    Behavioural Study of the Force Control Loop Used in a Collaborative Robot for Sanding Materials

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    [EN] The rise of collaborative robots urges the consideration of them for different industrial tasks such as sanding. In this context, the purpose of this article is to demonstrate the feasibility of using collaborative robots in processing operations, such as orbital sanding. For the demonstration, the tools and working conditions have been adjusted to the capacity of the robot. Materials with different characteristics have been selected, such as aluminium, steel, brass, wood, and plastic. An inner/outer control loop strategy has been used, complementing the robot¿s motion control with an outer force control loop. After carrying out an explanatory design of experiments, it was observed that it is possible to perform the operation in all materials, without destabilising the control, with a mean force error of 0.32%. Compared with industrial robots, collaborative ones can perform the same sanding task with similar results. An important outcome is that unlike what might be thought, an increase in the applied force does not guarantee a better finish. In fact, an increase in the feed rate does not produce significant variation in the finish¿less than 0.02 m; therefore, the process is in a ¿saturation state¿ and it is possible to increase the feed rate to increase productivity.Rodrigo Perez-Ubeda is grateful to the Ph.D. Grant CONICYT PFCHA/Doctorado Becas Chile/2017-72180157 and the University of Antofagasta, Chile.Pérez Ubeda, R.; Gutiérrez, SC.; Zotovic Stanisic, R.; Perles, A. (2020). Behavioural Study of the Force Control Loop Used in a Collaborative Robot for Sanding Materials. Materials. 14(1):1-19. https://doi.org/10.3390/ma14010067S11914

    Bounds on the dipole moments of the tau-neutrino via the process e+eννˉγe^{+}e^{-}\rightarrow \nu \bar \nu \gamma in a 331 model

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    We obtain limits on the anomalous magnetic and electric dipole moments of the ντ\nu_{\tau} through the reaction e+eννˉγe^{+}e^{-}\rightarrow \nu \bar \nu \gamma and in the framework of a 331 model. We consider initial-state radiation, and neglect WW and photon exchange diagrams. The results are based on the data reported by the L3 Collaboration at LEP, and compare favorably with the limits obtained in other models, complementing previous studies on the dipole moments.Comment: 13 pages, 4 figures, to be published in The European Physical J C. arXiv admin note: substantial text overlap with arXiv:hep-ph/060527

    Desarrollo ontogénico y cambio socioambiental en la comarca Lozoya- Somosierra (Madrid). 1981-1996.

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    This work aims to describe and to analyse the effects of socio-environmental changes on bioanthropological characteristics in the Lozoya-Somosierra area (Madrid) during 15 years. Several statistical techniques were carried out on the cense, interviews and mesure data of a schoolchildren sample. Results show a favorable effect of socio-economic improve, population hetero * Sección de Antropología. Facultad de Ciencias Biológicas. Universidad Complutense de Madrid. 223 M. D. Marrodán, et al. Desarrollo ontogénico y cambio socioambiental... genicity and nutritional and sanitary accesibility over the growth and maduration of children. These results are similar in other studies and they are in the same sense that the general idea about the human biological susceptibibility of the environment. RÉSUMÉ Le présent travail a pour objetif l'analyse de l'influence des changements socioenvironnementals qui ont eu place sur les charactéristiques bioantropologiques dans la région de Lozoya-Somosierra (Madrid) pendant 15 années. Les donnés, lesquels sont venues des registres censés, des enquêtes et des mesures sur un échantillon représentatif de la population scolaire, ont été analysées avec plusieurs techniques statistiques. Les résultats montre que les changements pour le progrès socioéconomique, la variabilité génétique et la accessibilité aux ressources nutritionnelles et sanitation, ont été un effet positif sur la croissance et la maduration de la population infantile. Ces resultats sont pareil avec d'autres études et avec la réflexion généralisée de la subceptibilité biologique humaine en face a l'environnement immédiat. 1.Este estudio describe y analiza las consecuencias bioantropológicas del cambio socioambiental acontecido en la comarca Lozoya-Somosierra (Madrid) durante 15 años. Los datos, procedentes de registros censales, encuestas y medición de una muestra representativa de la población escolar, se han analizado matemáticamente, empleando diferentes técnicas estadísticas. Los resultados indican que el cambio socioambiental que ha tenido lugar en la comarca entre los años 1981 y 1996, en el sentido de la mejora socioeconómica, la heterogenicidad poblacional y la accesibilidad a los recursos nutricionales y sanitarios, ha supuesto una repercusión positiva en el crecimiento y maduración de la población infantil. Son resultados en consonancia con otros estudios y con la reflexión generalizada de la susceptibilidad biológica humana frente a su entorno inmediato

    Accessing RDF(S) data resources in service-based Grid infrastructures

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    We describe the results of the RDF(S) activity within the Open Grid Forum (http://www.ogf.org) (OGF) Database Access and Integration Services (DAIS) Working Group (http://forge.gridforum.org/projects/dais-wg) whose objective is to develop standard service-based grid access mechanisms for data expressed in RDF and RDF Schema. We produce two specifications, focused on the provision of SPARQL querying capabilities for accessing RDF data and a set of RDF Schema ontology handling primitives for creating, retrieving, updating, and deleting RDF data. In this paper we present a set of use cases that justify this work and an overview of these specifications, which will enter in editorial process at OGF25. We conclude by outlining the future work that will be made in the context of this standardization process

    Limits on the Electromagnetic and Weak Dipole Moments of the Tau-Lepton in E_6 Superstring Models

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    We obtain limits on the electromagnetic and weak dipole moments of the tau-lepton in the framework of a Left-Right symmetric model (LRSM) and a class of E6E_6 inspired models with an additional neutral vector boson ZθZ_\theta. Using as an input the data obtained by the L3 and OPAL Collaborations for the reaction e+eτ+τγe^+e^-\to \tau^+\tau^-\gamma, we get a stringent limit on the LRSM mixing angle ϕ\phi, 1.66×103<ϕ<1.22×103-1.66\times 10^{-3}< \phi<1.22\times 10^{-3}, which in turn induces bounds on the tau weak dipole moments which are consistent with the bounds obtained recently by the DELPHI and ALEPH Collaborations from the reaction e+eτ+τe^+e^-\to \tau^+\tau^-. We also get similar bounds for the weak dipole moments of the tau lepton in the framework of E6E_6 superstring models.Comment: 18 pages, 5 figure

    Chilean sport sciences scientific production indexed in the Web of Science (1981-2016)

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    9 p.Objetivo: realizar un análisis bibliométrico de la producción científica chilena de Ciencias del deporte indexada en la Web of Science hasta 2016. Métodos: se analizaron los artículos y revisiones de Ciencias del deporte de Chile incluidos en los índices de la Colección principal de Web of Science hasta 2016. Los datos se recopilaron y filtraron en el programa Endnote X6 y luego se exportaron a Excel 2013, Bibexcel e Histcite para su análisis. La bibliometría se centró en la productividad, los sujetos y los patrones de colaboración. Resultados: Se encontraron un total de 152 documentos publicados desde 1981 hasta 2016. Las ciencias de la vida fueron el área de investigación principal (104), mientras que la fisiología (36) y la teoría del entrenamiento deportivo (30) fueron los sujetos más representados. La media de autores por artículo fue de 5,26 y el porcentaje de colaboración estuvo principalmente entre el 94% y el 100%. Ramírez-Campillo fue el autor más prolífico (24) y Caniuqueo logró el mayor índice de colaboración (10.83). Se descubrieron dos redes, con 20 y 10 académicos respectivamente y que representan 19 instituciones diferentes. Un grupo de 53 revistas diferentes ha difundido publicaciones de Ciencias del Deporte de Chile, pero 12 de ellas recolectaron el 60.53% de la producción total. Conclusión: la producción científica chilena de Ciencias del Deporte indexada en la Web of Science muestra el desarrollo progresivo y el fortalecimiento de este campo del conocimiento, claramente orientado a las Ciencias de la Vida, el trabajo en equipo y la colaboración internacional. También se debe destacar el establecimiento de una red que incluye académicos de Australia, Brasil, Canadá, Chile y España, que está impulsando la investigación de Ciencias del Deporte en este paísS

    Antispasmodic effects and action mechanism of essential oil of Chrysactinia mexicana A. Gray on rabbit ileum

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    The Chrysactinia mexicana A. Gray (C. mexicana) plant is used in folk medicine to treat fever and rheumatism; it is used as a diuretic, antispasmodic; and it is used for its aphrodisiac properties. This study investigates the effects of the essential oil of C. mexicana (EOCM) on the contractility of rabbit ileum and the mechanisms of action involved. Muscle contractility studies in vitro in an organ bath to evaluate the response to EOCM were performed in the rabbit ileum. EOCM (1–100 µg·mL-1) reduced the amplitude and area under the curve of spontaneous contractions of the ileum. The contractions induced by carbachol 1 µM, potassium chloride (KCl) 60 mM or Bay K8644 1 µM were reduced by EOCM (30 µg·mL-1). Apamin 1 µM and charybdotoxin 0.01 µM decreased the inhibition induced by EOCM. The d-cAMP 1 µM decreased the inhibition induced by EOCM. l-NNA 10 µM, Rp-8-Br-PET-cGMPS 1 µM, d, l-propargylglycine 2 mM, or aminooxyacetic acid hemihydrochloride 2 mM did not modify the EOCM effect. In conclusion, EOCM induces an antispasmodic effect and could be used in the treatment of intestinal spasms or diarrhea processes. This effect would be mediated by Ca2+, Ca2+-activated K+ channels and cAMP

    Prevalence of Resistant Strains of Rhipicephalus microplus to Acaricides in Cattle Ranch in the Tropical Region of Tecpan of Galeana, Guerrero, Mexico

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    Tick and tick borne diseases cause many problems to the cattle industry worldwide. The prevalence of resistant strains of Rhipicephalus microplus to different acaricides on cattle farms in the tropical region of Tecpan of Galeana, Guerrero, Mexico, and risk factors related to prevalence of resistant strains of R. microplus. Sixty one ranches infested were sampled; in each ranch were collected 30-50 fully-engorged female R. microplus ticks, of 10 cattle randomly selected, and evaluated in their progeny resistance to acaricides, using the larval packet test. The prevalence of resistant strains was total pyrethroids and amitraz. In organophosphorus 31.1, 48.3 and 82.2% of strains were resistant to clorpyriphos, coumaphos and diazinon, respectively. Risk factors favored (P<0.05) the development of resistant strains of acaricides. We concluded that the resistance of R. microplus to acaricides used to control a problem, and risk factors (livestock management) have accelerated the development of resistance
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