939 research outputs found

    Polar coherent states in bilayer graphene under a constant uniform magnetic field

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    Symmetries associated with the Hamiltonian describing bilayer graphene subjected to a constant magnetic field perpendicular to the plane of the bilayer are calculated using polar coordinates. These symmetries are then applied to explain some fundamental properties, such as the spectrum and the integer pseudo-spin character of the eigenfunctions. The probability and current densities of the bilayer Hamiltonian have also been calculated in polar coordinates and shown to be gauge invariant and scalar under generalized rotations. We also define appropriate coherent states of this system as eigenfunctions, with complex eigenvalues, of a suitable chose annihilation operator. In this framework, symmetries are also useful to show the meaning of the complex eigenvalue in terms of expected values. The local current density of these coherent states is shown to exhibit a kind of radial component interference effect, something that has gone unnoticed until now. Some of these results that have just been exposed are graphically illustrated throughout the manuscript

    Performance of Slow-Growing Chickens Fed with Tenebrio molitor Larval Meal as a Full Replacement for Soybean Meal

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    Insect larval meal is an increasingly common protein source in poultry systems. In this study, the effect of replacing soybean meal with Tenebrio molitor larval meal on the performance of slow-growing chickens was assessed. A total of 128 one-day-old chickens (Colorield) were randomly divided into a control group (C) (n = 64), fed with soybean meal, and an experimental group (TM) (n = 64), fed with T. molitor larvae meal. The chicks were slaughtered after 95 days. Three different isoenergetic and isoproteic diets (F1, F2 and F3) were used for each group. The F1 diet resulted in higher body weight gain and higher feed and water intakes in group C, but a lower feed conversion ratio. Contrarily, diets F2 and F3 did not produce differences in the studied parameters between the two groups, except for body weight gain in the case of diet F2, which was highest in group C. Therefore, weight gain and feed and water intakes were significantly higher in group C, but there were no differences in feed conversion ratio or live weight. In conclusion, the total replacement of soybean meal with T. molitor larvae meal resulted in a reduction in feed intake and a consequent reduction in weight. During this period, partial rather than total substitution may be recommended. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    El agregado de Hordeum murinum (poaceae) en “Flora iberica”

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    Hordeum murinum aggregate in “Flora iberica”Palabras clave. Hordeum, Poaceae, corología, taxonomía, Hordeae.Key words. Hordeum, Poaceae, chorology, taxonomy, Hordeae

    Modelo experimental de colocación de catéter intratecal lumbar para anestesia espinal en perros

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    Aunque existe controversia entre Corning y Bier, el primer caso de anestesia espinal se publica en el año 1885, cuando Cornig, accidentalmente, realiza un bloqueo espinal en un perro con cocaína. Desde entonces, la anestesia espinal probablemente ha sido la técnica regional más comúnmente utilizada en la moderna anestesia. Aunque se ha escrito mucho en lo relativo a dicha técnica: aplicaciones, complicaciones..., son pocos los estudios controlados, particularmente en animales donde ha sido posible mantener unas condiciones experimentales estandarizadas. Aún así, han sido descritos métodos experimentales de anestesia espinal 6-11 y epidural12-19 usando la implantación de catéteres en el perro, gato, oveja, rata y humanos. En la gran mayoría de los casos el acceso al espacio subaracnoideo se realiza quirúrgicamente vía occipital (se ha hecho en otras especies como en rata), llegando hasta la cisterna magna, donde puede quedar colocado el catéter, o bien prolongarlo hasta nivel torácico, lumbar. El presente estudio describe un modelo de implantación de catéter intradural en perros, con abordaje lumbar, con técnica quirúrgica previa y con control radioscópico

    Active disturbance rejection control: a guide for design and application

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    [EN] This tutorial addresses the design of controllers by active disturbance rejection control (ADRC). First, the main blocks in the ADRC loop are described. Next, the formulation of the control problem under the disturbance rejection framework is discussed, as well as the tuning of the gains set which are part of the main loop and a guide on designing of the active disturbance rejection controller is presented. This tutorial aims to offer an introduction to readers about the ADRC and a review of the most significant publications that have contributed to development and advance in the research related to the area. To illustrate the design procedure, two examples are included: thermal control and the multivariable control of a chemical process.[ES] Este tutorial aborda el diseño de controladores lineales por rechazo activo de perturbaciones (ADRC). Se inicia con la descripción de los bloques que componen el lazo ADRC. Seguidamente, se discute la formulación del problema de control en el marco del rechazo de perturbaciones, la sintonización del conjunto de ganancias que hacen parte del lazo y se presenta una guía general para el diseño del controlador lineal por rechazo activo de perturbaciones. Con este tutorial se pretende ofrecer una introducción a los lectores sobre el ADRC y una reseña de los trabajos que indican las tendencias de investigación en el área. Para ilustrar el procedimiento de diseño, se incluyen dos ejemplos: el control de un proceso térmico y el control multivariable de un proceso químico.Martínez, B.; Sanchis, J.; García-Nieto, S.; Martínez, M. (2021). Control por rechazo activo de perturbaciones: guía de diseño y aplicación. Revista Iberoamericana de Automática e Informática industrial. 18(3):201-217. https://doi.org/10.4995/riai.2020.14058OJS201217183Ahi, B., Haeri, M., 2018. Linear active disturbance rejection control from the practical aspects. IEEE/ASME Transactions on Mechatronics 23 (6), 2909-2919. https://doi.org/10.1109/tmech.2018.2871880Ahmad, S., Ali, A., 2019. Active disturbance rejection control of DC-DC boost converter: a review with modifications for improved performance. IET Power Electronics 12 (8), 2095-2107. https://doi.org/10.1049/iet-pel.2018.5767Albertos, P., Garcia, P., Gao, Z., Liu, T., 2014. Disturbance rejection in process control. In: Proceeding of the 11th World Congress on Intelligent Control and Automation. IEEE. https://doi.org/10.1109/wcica.2014.7053408Baquero-Suarez, M., Cortes-Romero, J., Arcos-Legarda, J., Coral-Enriquez, H., 2018. Estabilización automática de una bicicleta sin conductor mediante el enfoque de control por rechazo activo de perturbaciones. Revista Iberoamericana de Automática e Informática industrial 15 (1), 86-100. https://doi.org/10.4995/riai.2017.8832Castillo, A., García, P., Sanz, R., Albertos, P., 2018. Enhanced extended state observer-based control for systems with mismatched uncertainties and disturbances. ISA Transactions 73, 1-10. https://doi.org/10.1016/j.isatra.2017.12.005Chen, W.-H., Yang, J., Guo, L., Li, S., 2016. Disturbance-observer-based control and related methods-an overview. IEEE Transactions on Industrial Electronics 63 (2), 1083-1095. https://doi.org/10.1109/tie.2015.2478397Cheng, Y., Chen, Z., Sun, M., Sun, Q., Aug. 2019. Active disturbance rejection generalized predictive control for a high purity distillation column process with time delay. The Canadian Journal of Chemical Engineering 97 (11), 2941-2951. https://doi.org/10.1002/cjce.23513Chu, Z.,Wu, C., Sepehri, N., 2019. Active disturbance rejection control applied to high-order systems with parametric uncertainties. International Journal of Control, Automation and Systems 17 (6), 1483-1493. https://doi.org/10.1007/s12555-018-0509-8Feng, H., Guo, B.-Z., 2017. Active disturbance rejection control: Old and new results. Annual Reviews in Control 44, 238-248. https://doi.org/10.1016/j.arcontrol.2017.05.003Fu, C., Tan, W., 2016. Tuning of linear ADRC with known plant information. ISA Transactions 65, 384-393. https://doi.org/10.1016/j.isatra.2016.06.016Gao, Z., 2003. Scaling and bandwidth-parameterization based controller tuning. In: Proceedings of the 2003 American Control Conference, 2003. IEEE. https://doi.org/10.1109/acc.2003.1242516Gao, Z., 2014. On the centrality of disturbance rejection in automatic control. ISA Transactions 53 (4), 850-857. https://doi.org/10.1016/j.isatra.2013.09.012Guerrero-Ramírez, E. O., Martínez-Barbosa, A., Ramírez, E.-G., Linares-Flores, J., Sira-Ramírez, H., 2018. Control del convertidor CD/CD reductor-paralelo implementado en FPGA. Revista Iberoamericana de Automática e Informática industrial 15 (3), 309-316. https://doi.org/10.4995/riai.2018.8925Guo, B.-Z., Zhao, Z.-L., 2016. Active Disturbance Rejection Control for Nonlinear Systems. John Wiley & Sons Singapore Pte. Ltd. https://doi.org/10.1002/9781119239932Han, J., 2009. From PID to active disturbance rejection control. IEEE Transactions on Industrial Electronics 56 (3), 900-906. https://doi.org/10.1109/tie.2008.2011621He, T., Wu, Z., Li, D., Wang, J., 2020. A tuning method of active disturbance rejection control for a class of high-order processes. IEEE Transactions on Industrial Electronics 67 (4), 3191-3201. https://doi.org/10.1109/tie.2019.2908592Herbst, G., 2013. A simulative study on active disturbance rejection control (ADRC) as a control tool for practitioners. Electronics 2 (4), 246-279. https://doi.org/10.3390/electronics2030246Herbst, G., 2016. Practical active disturbance rejection control: Bumpless transfer, rate limitation, and incremental algorithm. IEEE Transactions on Industrial Electronics 63 (3), 1754-1762. https://doi.org/10.1109/tie.2015.2499168Huang, C., Du, B., 2016. Dierentially flatness active disturbance rejection control approach via algebraic parameter identification to double tank problem. In: 2016 35th Chinese Control Conference (CCC). IEEE. https://doi.org/10.1109/chicc.2016.7553678Huang, Y., Xue, W., 2014. Active disturbance rejection control: Methodology and theoretical analysis. ISA Transactions 53 (4), 963-976. https://doi.org/10.1016/j.isatra.2014.03.003Huilcapi, V., Herrero, J. M., Blasco, X., Martínez-Iranzo, M., 2017. Non-linear identification of a peltier cell model using evolutionary multi-objective optimization. IFAC-PapersOnLine 50 (1), 4448-4453. https://doi.org/10.1016/j.ifacol.2017.08.372Inoue, S., Ishida, Y., 2016. Design of a model-following controller using a decoupling active disturbance rejection control method. Journal of Electrical & Electronic Systems 05 (01). https://doi.org/10.4172/2332-0796.1000174Li, D., Chen, X., Zhang, J., Jin, Q., 2020. On parameter stability region of LADRC for time-delay analysis with a coupled tank application. Processes 8 (2), 223. https://doi.org/10.3390/pr8020223Li, J., Qi, X. H., Wan, H., Xia, Y. Q., 2017a. Active disturbance rejection control: theoretical results summary and future researches. Kongzhi Lilun Yu Yingyong/Control Theory and Applications 34, 281-295. https://doi.org/10.7641/CTA.2017.60363Li, J., Xia, Y., Qi, X., Gao, Z., 2017b. On the necessity, scheme, and basis of the linear-nonlinear switching in active disturbance rejection control. IEEE Transactions on Industrial Electronics 64 (2), 1425-1435. https://doi.org/10.1109/tie.2016.2611573Li, S., Yang, J., Chen,W.-H., Chen, X., 2012. Generalized extended state observer based control for systems with mismatched uncertainties. IEEE Transactions on Industrial Electronics 59 (12), 4792-4802. https://doi.org/10.1109/tie.2011.2182011Liang, Q., Wang, C. B., Pan, J. W., Wei, Y. H., Wang, Y., 2015. Parameter identification of b0 and parameter tuning law in linear active disturbance rejection control. Kongzhi yu Juece/Control and Decision 30, 1691-1695. https://doi.org/10.13195/j.kzyjc.2014.0943Luyben, W. L., 1990. Process Modeling, Simulation, and Control for Chemical Engineers. McGraw-Hill.Madonski, R., Gao, Z., Lakomy, K., 2015. Towards a turnkey solution of industrial control under the active disturbance rejection paradigm. In: 2015 54th Annual Conference of the Society of Instrument and Control Engineers of Japan (SICE). IEEE. https://doi.org/10.1109/sice.2015.7285478Madonski, R., Piosik, A., Herman, P., 2013. High-gain disturbance observer tuning seen as a multicriteria optimization problem. In: 21st Mediterranean Conference on Control and Automation. IEEE. https://doi.org/10.1109/med.2013.6608905Madonski, R., Shao, S., Zhang, H., Gao, Z., Yang, J., Li, S., 2019. General error-based active disturbance rejection control for swift industrial implementations. Control Engineering Practice 84, 218-229. https://doi.org/10.1016/j.conengprac.2018.11.021Marlin, T., 2000. Process Control: Designing Processes and Control Systems for Dynamic Performance. McGraw-Hill.Martínez, B. V., Jul 2020. Active Disturbance Rejection Control-implementation examples. Version 1.0.0. url: https://www.mathworks.com/matlabcentral/fileexchange/78459.Maxim, A., Copot, D., Copot, C., Ionescu, C. M., 2019. The 5w's for control as part of industry 4.0: Why, what, where, who, and when-a PID and MPC control perspective. Inventions 4 (1), 10. https://doi.org/10.3390/inventions4010010Nowicki, M., Madonski, R., Kozlowski, K., 2015. First look at conditions on applicability of ADRC. In: 2015 10th International Workshop on Robot Motion and Control (RoMoCo). IEEE. https://doi.org/10.1109/romoco.2015.7219750Parvathy, R., Daniel, A. E., 2013. A survey on active disturbance rejection control. In: 2013 International Mutli-Conference on Automation, Computing, Communication, Control and Compressed Sensing (iMac4s). IEEE. https://doi.org/10.1109/imac4s.2013.6526432Pérez-Polo, M., Albertos, P., 2007. Nonisothermal stirred-tank reactor with irreversible exothermic reaction a ! b: 2. nonlinear phenomena. In: Selected Topics in Dynamics and Control of Chemical and Biological Processes. Springer Berlin Heidelberg, pp. 243-279. https://doi.org/10.1007/978-3-540-73187_8Reynoso, G., Blasco, X., Sanchis, J., Herrero, J. M., 2017. Controller Tuning with Evolutionary Multiobjective Optimization. Springer International Publishing. https://doi.org/10.1007/978-3-319-41301-3Sanz, R., Garcia, P., Albertos, P., 2015. Active disturbance rejection by state feedback: Experimental validation in a 3-dof quadrotor platform. In: 2015 54th Annual Conference of the Society of Instrument and Control Engineers of Japan (SICE). pp. 794-799. https://doi.org/10.1109/SICE.2015.7285349Sira-Ramírez, H., 2018. From flatness, GPI observers, GPI control and flat filters to observer-based ADRC. Control Theory and Technology 16 (4), 249-260. https://doi.org/10.1007/s11768-018-8134-xSun, L., Li, D., Gao, Z., Yang, Z., Zhao, S., 2016. Combined feedforward and model-assisted active disturbance rejection control for non-minimum phase system. ISA Transactions 64, 24-33. https://doi.org/10.1016/j.isatra.2016.04.020Sun, L., Zhang, Y., Li, D., Lee, K. Y., 2019. Tuning of active disturbance rejection control with application to power plant furnace regulation. Control Engineering Practice 92, 104122. https://doi.org/10.1016/j.conengprac.2019.104122Tan,W., Fu, C., 2016. Linear active disturbance-rejection control: Analysis and tuning via imc. IEEE Transactions on Industrial Electronics 63 (4), 2350-2359.Teppa-Garran, P., Garcia, G., 2014. ADRC tuning employing the LQR approach for decoupling uncertain MIMO systems. Information Technology And Control 43 (2). https://doi.org/10.5755/j01.itc.43.2.4059Wu, X., Chen, Z., Zhao, Y., Sun, L., Sun, M., 2018. A comprehensive decoupling control strategy for a gas flow facility based on active disturbance rejection generalized predictive control. The Canadian Journal of Chemical Engineering 97 (3), 762-776. https://doi.org/10.1002/cjce.23215Xue,W., Huang, Y., 2015. Performance analysis of active disturbance rejection tracking control for a class of uncertain LTI systems. ISA Transactions 58, 133-154. https://doi.org/10.1016/j.isatra.2015.05.001Xue, W., Huang, Y., Gao, Z., 2016. On ADRC for non-minimum phase systems: canonical form selection and stability conditions. Control Theory and Technology 14 (3), 199-208. https://doi.org/10.1007/s11768-016-6041-6Zhang, B., Tan, W., Li, J., 2019. Tuning of linear active disturbance rejection controller with robustness specification. ISA Transactions 85, 237-246. https://doi.org/10.1016/j.isatra.2018.10.018Zhao, C., Li, D., 2014. Control design for the SISO system with the unknown order and the unknown relative degree. ISA Transactions 53 (4), 858-872. https://doi.org/10.1016/j.isatra.2013.10.001Zhao, C., Li, D., Cui, J., Tian, L., 2018. Decentralized low-order ADRC design for MIMO system with unknown order and relative degree. Personal and Ubiquitous Computing 22 (5-6), 987-1004. https://doi.org/10.1007/s00779-018-1158-xZhao, S., Gao, Z., 2010. Active disturbance rejection control for non-minimum phase systems. In: Proceedings of the 29th Chinese Control Conference. pp. 6066-6070.Zhao, S., Gao, Z., 2014. Modified active disturbance rejection control for time delay systems. ISA Transactions 53 (4), 882-888. https://doi.org/10.1016/j.isatra.2013.09.013Zhao, S., Xue, W., Gao, Z., 2013. Achieving minimum settling time subject to undershoot constraint in systems with one or two real right half plane zeros. Journal of Dynamic Systems, Measurement, and Control 135 (3). https://doi.org/10.1115/1.4023211Zheng, Q., Chen, Z., Gao, Z., 2009. A practical approach to disturbance decoupling control. Control Engineering Practice 17 (9), 1016-1025. https://doi.org/10.1016/j.conengprac.2009.03.005Zheng, Q., Gao, L. Q., Gao, Z., 2012. On validation of extended state observer through analysis and experimentation. Journal of Dynamic Systems, Measurement, and Control 134 (2). https://doi.org/10.1115/1.4005364Zheng, Q., Gao, Z., 2010. On practical applications of active disturbance rejection control. In: Proceedings of the 29th Chinese Control Conference. pp. 6095-6100.Zheng, Q., Gao, Z., 2016. Active disturbance rejection control: between the formulation in time and the understanding in frequency. Control Theory and echnology 14 (3), 250-259. https://doi.org/10.1007/s11768-016-6059-9Zheng, Q., Gao, Z., 2018. Active disturbance rejection control: some recent experimental and industrial case studies. 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    GPS, LiDAR and VNIR data to monitor the spatial behavior of grazing sheep

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    Traditional knowledge about the behavior of grazing livestock is about to disappear. Shepherds well know that sheep behavior follows non-random patterns. As a novel alternative to seeking behavioral patterns, this study quantified the grazing activities of two sheep flocks of Churra breed (both in the same area but separated by 10 years) based on Global Position System (GPS) monitoring and remote monitoring sensing techniques. In the first monitoring period (2009-10), geolocations were recorded every 5 min (4, 240 records), while in the second one (2018-20), records were taken every 30 min (7, 636 records). The data were clustered based on the day/night and the activity (resting, moving, or grazing). An airborne LiDAR dataset was used to study the slope, aspect, and vegetation height. Four visible-infrared orthophotographs were mosaicked and classified to obtain the land use/land cover (LU/LC) map. Then, GPS locations were overlain on the terrain features, and a Chi-square test evaluated the relationships between locations and terrain features. Three spatial statistics (directional distribution, Kernel density, and Hot Spot analysis) were also calculated. Results in both monitoring periods suggested that the spatial distribution of free-grazing ewes was non-random. The flocks showed strong preferences for grazing areas with gentle north-facing slopes, where the herbaceous layer formed by pasture predominates. The geostatistical analyses of the sheep locations corroborated those preferences. Geotechnologies have emerged as a potent tool to demonstrate the influence of environmental and terrain attributes on the non-random spatial behavior of grazing sheep. © 2022 Malque Publishing. All rights reserved

    Cough reflex testing with inhaled capsaicin in the study of chronic cough

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    AbstractObjectives: To assess the utility of capsaicin test in the differential diagnosis of non-productive causes of chronic cough and to examine the effects of treatment on this reflex. Participants: 86 healthy volunteers and 101 patients with chronic cough: asthma (n: 54), gastroesophageal reflux (n: 35) and post-nasal drip syndrome (n: 12). Design: Prospective intervention trial. Spirometry, bronchoprovocation test with histamine (PC20), and cough challenge with ascending concentrations of capsaicin (0.49–500 μM) were initially performed in all subjects. Patients were treated for 3 months according to the origin of the cough. Concentrations that elicited two (C2) and five or more coughs (C5) were determined before and after treatment.Results: In healthy subjects, cough sensitivity to capsaicin was not influenced by gender or smoking status; however, women with chronic cough were more sensitive to cough challenge than men. C2 and C5 were significantly lower in patients with asthma or gastroesophageal reflux than in post-nasal drip syndrome. No significant correlation was observed between the capsaicin cough threshold and PC20. Cough sensitivity did not improve significantly in most patients with asthma or gastroesophageal reflux despite adequate medical treatment during 3 months. Discriminative value of capsaicin test to differentiate healthy subjects from patients with asthma or reflux was poor. Conclusions: Cough sensitivity to inhaled capsaicin is a safe and reproducible tool in the study of chronic cough. However, its usefulness for the management and differential diagnosis is limited
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