Advancing towards a Practical Magnesium Ion Battery

A post-lithium battery era is envisaged, and it is urgent to find new and sustainable systems for energy storage. Multivalent metals, such as magnesium, are very promising to replace lithium, but the low mobility of magnesium ion and the lack of suitable electrolytes are serious concerns. This review mainly discusses the advantages and shortcomings of the new rechargeable magnesium batteries, the future directions and the possibility of using solid electrolytes. Special emphasis is put on the diversity of structures, and on the theoretical calculations about voltage and structures. A critical issue is to select the combination of the positive and negative electrode materials to achieve an optimum battery voltage. The theoretical calculations of the structure, intercalation voltage and diffusion path can be very useful for evaluating the materials and for comparison with the experimental results of the magnesium batteries which are not hassle-free

Screening of herbicides in grain legumes: pre-emergence herbicides in faba beans

Ante la escasez de herbicidas autorizados en leguminosas, se realizaron dos ensayos en habas con 10 herbicidas elegidos por estar autorizados en otras leguminosas o en otros países. Ninguno de los productos resultó totalmente eficaz y selectivo. Algunos de los herbicidas de preemergencia autorizados en España en habas para grano resultaron menos eficaces contra las malas hierbas y produjeron mayor fitotoxicidad que otros no autorizados. Así mismo, productos autorizados en Francia resultaron fitotóxicos en nuestras condiciones. Los mejores resultados seguido de ixosaben y aclonifen. Sin embargo será necesario ajustar dosis y buscar otras alternativas, como combinaciones de productos o estrategias de control para mejorar las eficacias y la selectividad, y sobre todo elegir los productos en función de las especies de malas hierbas dominantes en cada finca.Faced with a shortage of herbicides in legumes, two trials were conducted in faba beans to evaluate 10 herbicides elected by being authorized in other legumes or in other countries. None of the product was completely effective and selective. Some of the pre-emergence herbicides authorized in Spain for grain faba beans were less effective against weeds and produced more phytotoxicity than others not authorized. Likewise, products authorized in France turned out quite phytotoxic in our conditions. The best results were obtained with metribuzin by its effective weed control and low phytotoxicity, followed by ixosaben and aclonifen. However it will be necessary to adjust dose, to look for other alternatives, such as combinations of products or control strategies to improve effectiveness and selectivity, and above all choose the products depending on the species of dominant weeds in each farm

ANALYSIS OF THE INFLUENCE OF DIFFERENT TREKKING BOOTS ON CHILDREN’S LOCOMOTOR ABILITY

The use of trekking boots for daily activities has greatly increased among children. This type of footwear can modify the locomotor ability of children due to alterations in ankle, leg and foot movements caused by upper height and sole stiffness, modifications of children’s perception of shoe size caused by a greater size, as well as energy cost due to boot weight, as observed in adults (Jones et al., 1986; Robinson et al., 1986), which can cause balance and performance problems. The influence of three different trekking boots on children’s locomotor ability and performance was studied in tests on children. Two boots differed only in the lacing system (one included an extra velcrum around the ankle) whilst the third was smaller, lighter and more flexible. The children performed performance tests running along an obstacle circuit (Brizuela, et al., 1997) using an electronic system for measuring time and ability tests on a new fixed-goal tasks (FGTT) circuit. This circuit included 13 different tasks on a restricted path which were evaluated on a three point scale from absence of error to grave error; global time and the number of errors were also measured. Results showed a high frequency of errors in many of the tasks in the FGTT circuit, mainly related to equilibrium, precision tasks and kicking obstacles. However, few differences were found within boots. The higher boots had a statistically significant (p=0.027) greater number of total errors, whilst 27.8% (Sommers D) of errors observed on the equilibrium bar were significantly attributed (0.041) to the higher boots without extra velcrum. These results related errors to lower rear foot stability and poor perception of shoe size. No statistically significant differences were found among boots in global time. No statistically significant differences within boots were found in time of circuit performance (if any, it should be lower than 2%). The main influence on children’s motor skills seemed to be the fact of wearing boots, with little influence exercised by boot design. Nevertheless, the differences observed were due to the influence on rear foot stability of boot design and size, and children’s perception of shoe size. REFERENCES: Brizuela, G., Llana, S., Ferrandis, R., García, A. (1997).The Influence of Basketball Shoes with Increased Ankle Support on Shock Attenuation and Performance in Running and Jumping. Journal of Sports Sciences 15, 505-515. Jones, B. H., Knapik, J. J., Daniels, W. L., Toner, M. M. (1986).The Energy Cost of Women Walking and Running in Shoes and Boots. Ergonomics 29, 439-443. Robinson, J. R., Frederick, E. C., Cooper, L. B. (1986). Systematic Ankle Stabilization and the Effect on Performance. Med. and Sci. in Sports and Exer. 18, 625-628

A FIXED-GOAL TASKS (FGTT) CIRCUIT: A NEW TECHNIQUE TO ASSESS FOOTWEAR INFLUENCE ON CHILDREN’S LOCOMOTOR ABILITY

Footwear does not influence children’s locomotor ability in just a single way. It is the result of a complex interaction of design, mechanical properties, fitting, etc. As a result, subjective techniques are better suited for its study. Some investigators have used these techniques to study motor skills in children (Pryde et al., 1997), but few works have focused on the assessment of children’s footwear (Gould, 1985). This work presents a new technique for the analysis of footwear influences on children’s locomotor ability. An obstacle walking circuit was designed in which 13 fixed-goal tasks (FGTT) were included. Each task was designed for compromising either a single or complex movement or motor skill of children. Obstacles of increasing complexity were placed along the circuit on a restricted path with visual clues. Seven children (mean age = 8.4) participated in an experiment with three different pairs of hiking boots. The time required to complete the circuit was recorded for each trial. A three point scale was used to visually quantify the performance in each task: (0) absence of error, (1) slight error and (2) grave error. The total number of errors was also computed. Descriptive statistics of errors were gathered. The influence of shoes on global time and errors was analyzed. Factor analysis of Principal Components was used to identify the association among the most frequent errors. The relationship of error groups with time and boots, as well as the accommodation of children to walking conditions were also analyzed. A high frequency of errors in many of the tasks was observed. However, little differences in time and errors were observed with the same shoes, so the circuit really demonstrated to compromise children’s ability. Quick accommodation of the children was observed. The first trial was the slowest, and the frequency of errors in the tasks decreased from 13.0 % to 3.8% when performed four more times. Factor Analysis resulted in five error groups which were related to 1) bad perception of whole shoe size and 2) of shoe point, 3) the influence in medial-lateral movements, 4) a complex movement of the lower leg and the foot followed by precise positioning and 5) stepping over the first high obstacle in the circuit. No significant relationship of error groups with time and type of boot was found.This technique yielded interesting relationships of performance in fixed-goal tasks with aspects of footwear influence on children’s motor skills which would allow the assessment of children’s footwear design. The small differences among boots found in this experiment could be due to the fact that the tested boots were very similar. REFERENCES: Gould, N. (1985). Shoes Versus Sneakers in Toddler Ambulation. Foot Ankle 6, 105-107. Pryde, K. M.; Roy, E. A.; Patla, A. E. (1997). Age-related trends in locomotor ability and obstacle avoidance. Human Movement Science, 16, 507-516

Magnesium Deintercalation From the Spinel-Type MgMn2-yFeyO4 (0.4≤y≤2.0) by Acid-Treatment and Electrochemistry

Rechargeable magnesium batteries attract lots of attention because of their high safety and low cost compared to lithium batteries, and it is needed to develop more efficient electrode materials. Although MgMn2O4 is a promising material for the positive electrode in Mg rechargeable batteries, it usually exhibits poor cyclability. To improve the electrochemical behavior, we have prepared nanoparticles of MgMn2-yFeyO4. The XRD results have confirmed that when Mn3+ (Jahn-Teller ion) ions are replaced by Fe3+ (non-Jahn-Teller ion), the resulting MgMn2-yFeyO4 is a cubic phase. The structure and theoretical voltage are theoretically calculated by using the DFT method. The obtained samples have been chemically treated in acid solution for partial demagnesiation, and it is observed that the presence of iron inhibits the deinsertion of Mg through disproportionation and favors the exchange reaction. The electrochemical behavior in non-aqueous magnesium cells has been explored

Gestión estratégica de las posadas

This article examines the inns in the hospitality sector because in Venezuela this concept has been very successful in the last years, so it plays a very important role. This study is enmarked within the new parameters of theeconomic field, this situation has derived of the intense competence and the need of offer diversification, and the purpose to enhance the market position of the destination an cut down alterations of the ecosystem and in the population, where the human dimension of hospitality plays a leading role to ensure the success on this proposal. The strategic aspects of inns' management were established. These aspects were viewed in two ways: from the point of view of a sustainable development which promte a horizontal integration or a chain of services in the destination, and it 's action as a business unit.Este artículo presenta la gestión de las posadas en el sector de la hospitalidad, debido a que dicha modalidad ha tenido un gran auge en los últimos afios en Venezuela, Considera los parámetros del actual escenario económico, derivado de la intensa competencia y de la necesidad de diversificar la oferta, con el fio de potenciar el posicionamiento de los destinos y disminuir alteraciones en los ecosistemas y en la población, donde la dimensión humana de la hospitalidad prevalezca y asegure el éxito en la ejecución de este planteamiento, Al considerar los lineamientos de una estrategia de gestión de las posadas, éstos se ubicaron en dos vertientes: en una integración horizontal o cadena de servicios y en su acción como unidad de negocio

PID Tuning: Analytical approach based on the weighted Sensitivity problem

[EN] The PID controller is the most common option in the realm of control applications and is dominant in the process control industry. Among the related analytical methods, Internal Model Control (IMC) has gained remarkable industrial acceptance due to its robust nature and good set-point responses. However, the traditional application of IMC results in poor load disturbance rejection for lag-dominant and integrating plants. This work presents an IMC-like design method which avoids this common pitfall and is devised to work well for plants of modest complexity, for which analytical PID tuning is plausible. For simplicity, the design only focuses on the closed-loop sensitivity function. The approach provides model-based tuning of single-loop PID controllers in terms of the robustness/performance and servo/regulator trade-offs. Although the robustness/performance compromise is commonly considered, it is not so common to also take into account, for example, the conflict between input and output disturbances, referred also as the servo/regulator trade-off. As interested in providing a unified tuning approach, it is shown how the proposed methodology allows to deal with different process dynamics in a unified way.[ES] El controlador PID es la opción más común en el ámbito de las aplicaciones de control, siendo la opción predominante en el control de procesos industriales. Entre los métodos analíticos más usuales utilizados para su diseño, el Control por Modelo Interno (IMC) ha ganado una notable aceptación industrial debido a su naturaleza robusta y buenas respuestas ante cambios de consigna. Sin embargo, la aplicación tradicional del IMC da como resultado un bajo rendimiento para el rechazo de perturbaciones en carga para plantas integradoras y/o con largas constantes de tiempo. Este trabajo presenta un método de diseño, basado en IMC, que evita esta deficiencia y está diseñado para funcionar bien en plantas de complejidad moderada para las cuales, por otro lado, el ajuste analítico de un controlador PID es plausible. Por simplicidad, el diseño solo se centra en la función de sensibilidad en lazo cerrado. El enfoque proporciona un ajuste basado en modelo en términos de los compromisos robustez/rendimiento y de servo/regulación. Aunque comúnmente se considera el compromiso robustez/rendimiento, no es tan común tener en cuenta también, por ejemplo, el conflicto entre las perturbaciones de entrada y salida, también conocido como el compromiso servo/regulación. Con el objetivo de proporcionar un enfoque de ajuste unificado, se muestra como la metodología propuesta permite tratar diferentes dinámicas de proceso de manera unificada.Los autores desean agradecer al Ministerio de Economía y Competitividad bajo las subvenciones DPI-2016-77271-R y PID2019-105434RB-C33 por la ayuda que han supuesto en la elaboración de los trabajos que han conducido a los desarrollos aquí presentados.Vilanova, R.; Alcántara, S.; Pedret, C. (2021). Sintonía de controladores PID: un enfoque analítico basado en el moldeo de la función de sensibilidad. Revista Iberoamericana de Automática e Informática industrial. 18(4):313-326. https://doi.org/10.4995/riai.2021.15422OJS313326184Alcántara, S., Vilanova, R., Pedret, C., 2013. PID control in terms of robustness/performance and servo/regulator trade-offs: A unifying approach to balanced autotuning. Journal of Process Control 23 (4), 527 - 542. https://doi.org/10.1016/j.jprocont.2013.01.003Alcántara, S., Pedret, C., Vilanova, R., 2010. On the model matching approach to PID design: Analytical perspective for robust Servo/Regulator tradeoff tuning. Journal of Process Control 20 (5), 596 - 608. https://doi.org/10.1016/j.jprocont.2010.02.011Alcántara, S., Pedret, C., Vilanova, R., Skogestad, S., 2011a. Generalized Internal Model Control for balancing input/output disturbance response. Industrial & Engineering Chemistry Research 50 (19), 11170-11180. https://doi.org/10.1021/ie200717zAlcántara, S., Vilanova, R., Pedret, C., 2020. PID Tuning: A Modern Approach via the Weighted Sensitivity Problem (1st ed.). CRC Press. https://doi.org/10.1201/9780429325335-1Alcántara, S., Vilanova, R., Pedret, C., Skogestad, S., 2012. A look into robustness/performance and servo/regulation issues in PI tuning. In: Proc. of the IFAC Conf. on Advances in PID Control PID'12. https://doi.org/10.3182/20120328-3-IT-3014.00031Alcántara, S., Zhang, W., Pedret, C., Vilanova, R., Skogestad, S., 2011b. IMC-like analytical H-inf design with S/SP mixed sensitivity consideration: Utility in PID tuning guidance. Journal of Process Control 21 (6), 976 - 985. https://doi.org/10.1016/j.jprocont.2011.04.007Alfaro, V. M., Vilanova, R., 2013a. Performance and Robustness Considerations for Tuning of Proportional Integral/Proportional Integral Derivative Controllers with Two Input Filters. Industrial & Engineering Chemistry Research 52, 18287-18302. https://doi.org/10.1021/ie4012694Alfaro, V. M., Vilanova, R., 2013b. Robust tuning of 2DoF five-parameters PID controllers for inverse response controlled processes. Journal of Process Control 23, 453-462. https://doi.org/10.1016/j.jprocont.2013.01.005Alfaro, V. M., Vilanova, R., September 2013c. Simple robust tuning of 2DoF PID controllers from a performance/robustness trade-off analysis. Asian Journal of Control 15 (5), 1-14. https://doi.org/10.1002/asjc.653Alfaro, V. M., Vilanova, R., 2016. Model-Reference Robust Tuning of PID Controllers. Springer International Publishing AG, Gewerbestrasse 11, 6330 Cham, Switzerland, ISBN 978-3-319-28213-8.Alfaro, V. M., Vilanova, R., Méndez, R., Lafuente, J., 2010. Performance/Robustness Tradeoff Analysis of PI/PID Servo and Regulatory Control Systems. In: Proc. of the IEEE International Conference on Industrial Technology. https://doi.org/10.1109/ICIT.2010.5472662Arrieta, O., Vilanova, R., 2012. Simple servo/regulation proportional-integralderivative (pid) tuning rules for arbitrary ms-based robustness achievement. Industrial & Engineering Chemistry Research 51 (6), 2666-2674. https://doi.org/10.1021/ie201655cArrieta, O., Vilanova, R., Rojas, J. D., Meneses, M., 2016. Improved pid controller tuning rules for performance degradation/robustness increase trade-off. Electrical Engineering 98 (3), 233-243. https://doi.org/10.1007/s00202-016-0361-xArrieta, O., Visioli, A., Vilanova, R., 2010. PID autotuning for weighted servo/regulation control operation. Journal of Process Control 20 (4), 472 -480. https://doi.org/10.1016/j.jprocont.2010.01.002Astrom, K., Hagglund, T., 2004. Revisiting the Ziegler-Nichols step response method for PID control. J. Process Control 14, 635-650. https://doi.org/10.1016/j.jprocont.2004.01.002Astrom, K., Hagglund, T., 2005. Advanced PID control. ISA - The Instrumentation, Systems, and Automation Society.Chien, I. L., Fruehauf, P. S., 1990. Consider IMC tuning to improve controller performance. Chemical Engineering Progress 86 (10), 33 - 41.Dehghani, A., Lanzon, A., Anderson, B., 2006. H1 design to generalize internalmodel control. Automatica 42 (11), 1959 - 1968.Grimholt, C., Skogestad, S., 2012. Optimal PI Control and Verifcation of the SIMC Tuning Rule. In: Proc. of the IFAC Conf. on Advances in PID Control PID'12. https://doi.org/10.3182/20120328-3-IT-3014.00003Horn, I. G., Arulandu, J. R., Gombas, C. J., VanAntwerp, J. G., Braatz, R. D., 1996. Improved Filter Design in Internal Model Control. Industrial & Engineering Chemistry Research 35 (10), 3437 - 3441. https://doi.org/10.1021/ie9602872Huba, M., 2012. Setpoint Versus Disturbance Responses of the IPDT Plant. In: Proc. of the IFAC Conf. on Advances in PID Control PID'12. https://doi.org/10.3182/20120328-3-IT-3014.00070J.Shi, W.S.Lee, 2004. Set Point Response and Disturbance Rejection Tradeoff for Second-Order Plus Dead Time Processes. In: Asian Control Conference.Kristiansson, B., Lennartson, B., 1998. Optimal PID controllers for unstable and resonant plants. In: Proc. of the IEEE Conference on Decision and Control. pp. 4380-4381.Kurokawa, R., Sato, T., Vilanova, R., Konishi, Y., 2019. Discrete-time firstorder plus dead-time model-reference trade-off pid control design. Applied Sciences 9 (16). https://doi.org/10.3390/app9163220Kurokawa, R., Sato, T., Vilanova, R., Konishi, Y., 2020. Design of optimal pid control with a sensitivity function for resonance phenomenon-involved second-order plus dead-time system. Journal of the Franklin Institute 357 (7), 4187-4211. https://doi.org/10.1016/j.jfranklin.2020.03.015Leva, A., Maggio, M., 2012. Model-Based PI(D) Autotuning. In: PID Control in the Third Millennium. Lessons Learned and New Approaches. Springer. https://doi.org/10.1007/978-1-4471-2425-2_2Mercader, P., Astrom, K. J., Baños, A., Hagglund, T., 2017a. Robust pid design based on qft and convex?concave optimization. IEEE Transactions on Control Systems Technology 25 (2), 441-452. https://doi.org/10.1109/TCST.2016.2562581Mercader, P., Baños, A., 2017. A pi tuning rule for integrating plus dead time processes with parametric uncertainty. ISA Transactions 67, 246-255. https://doi.org/10.1016/j.isatra.2017.01.025Mercader, P., Baños, A., Vilanova, R., 2017b. Robust proportional-integral-derivative design for processes with interval parametric uncertainty. IET Control Theory & Applications 11 (7), 016-1023. https://doi.org/10.1049/iet-cta.2016.1239Mercader, P., Soltesz, K., Baños, A., 2017c. Robust pid design by chance-constrained optimization. Journal of the Franklin Institute 354 (18), 8217-8231. https://doi.org/10.1016/j.jfranklin.2017.10.017Meza, G. R., Ferragud, X. B., Saez, J. S., Dur, J. M. H., 2016. Controller Tuning with Evolutionary Multiobjective Optimization: A Holistic Multiobjective Optimization Design Procedure, 1st Edition. Springer Publishing Company, Incorporated.Middleton, R. H., Graebe, S. F., 1999. Slow stable open-loop poles: to cancel or not to cancel. Automatica 35 (5), 877-886. https://doi.org/10.1016/S0005-1098(98)00220-9Morari, M., Zafiriou, E., 1989. Robust Process Control. Prentice-Hall International.Panagopoulos, H., Astrom, K. J., 2000. PID control design and H1 loop shaping. International Journal of Robust and Nonlinear Control 10 (15), 1249-1261. https://doi.org/10.1002/1099-1239(20001230)10:153.0.CO;2-7Pedret, C., Vilanova, R., Moreno, R., Serra, I., 2002. A refinement procedure for PID controller tuning. Computers & Chemical Engineering 26 (6), 903- 908. https://doi.org/10.1016/S0098-1354(02)00011-XRivera, D. E., Morari, M., Skogestad, S., 1986. Internal model control: PID controller design. Industrial & Engineering Chemistry Process Design and Development 25 (1), 252 - 265. https://doi.org/10.1021/i200032a041Rodriguez, C., September 2020. Revisiting the simplified imc tuning rules for low-order controllers: Novel 2dof feedback controller. IET Control Theory & Applications 14, 1700-1710(10). https://doi.org/10.1049/iet-cta.2019.0821Ruscio, D. D., 2010. On Tuning PI Controllers for Integrating Plus Time Delay Systems. Modeling, Identification and Control 31 (4), 145 - 164. https://doi.org/10.4173/mic.2010.4.3Samad, T., Feb 2017. A survey on industry impact and challenges thereof [technical activities]. CSM 37 (1), 17-18. https://doi.org/10.1109/MCS.2016.2621438Sanchez, H. S., Padula, F., Visioli, A., Vilanova, R., 2017a. Tuning rules for robust fopid controllers based on multi-objective optimization with fopdt models. ISA Transactions 66, 344-361. https://doi.org/10.1016/j.isatra.2016.09.021Sanchez, H. S., Visioli, A., Vilanova, R., 2017b. Optimal nash tuning rules for robust pid controllers. Journal of the Franklin Institute 354 (10), 3945-3970.https://doi.org/10.1016/j.jfranklin.2017.03.012Sato, T., Hayashi, I., Horibe, Y., Vilanova, R., Konishi, Y., 2019. Optimal robust pid control for first- and second-order plus dead-time processes. Applied Sciences 9 (9). https://doi.org/10.3390/app9091934Sato, T., Tajika, H., Vilanova, R., Konishi, Y., 2018. Adaptive pid control system with assigned robust stability. IEEJ Transactions on Electrical and Electronic Engineering 13 (8), 1169-1181. https://doi.org/10.1002/tee.22680Shamsuzzoha, M., Lee, M., 2007. IMC-PID Controller Design for Improved Disturbance Rejection of Time-Delayed Processes. Industrial & Engineering Chemistry Research 46 (7), 2077 - 2091. https://doi.org/10.1021/ie0612360Shamsuzzohaa, M., Skogestad, S., 2010. The setpoint overshoot method: A simple and fast closed-loop approach for PID tuning. Journal of Process Control 20 (10), 1220 - 1234. https://doi.org/10.1016/j.jprocont.2010.08.003Skogestad, S., 2003. Simple analytic rules for model reduction and PID controller tuning. J. Process Control 13, 291-309. https://doi.org/10.1016/S0959-1524(02)00062-8Skogestad, S., Grimholt, C., 2012. PID Tuning for Smooth Control. In: PID Control in the Third Millennium. Lessons Learned and New Approaches. Springer.Skogestad, S., Postlethwaite, I., 2005. Multivariable Feedback Control. Wiley.Smuts, J. F., 2011. Process Control for Practitioners: How to Tune PID Controllers and Optimize Control Loops. OptiControls.Vilanova, R., 2008. IMC based Robust PID design: Tuning guidelines and automàtic tuning. Journal of Process Control 18, 61-70. https://doi.org/10.1016/j.jprocont.2007.05.004Vilanova, R., Arrieta, O., 2007. PID design for improved disturbance attenuation: min max Sensitivity matching approach. IAENG International Journal of Applied Mathematics 37 (1).Vilanova, R., Arrieta, O., Ponsa, P., 2018. Robust pi/pid controllers for load disturbance based on direct synthesis. ISA Transactions 81, 177-196. https://doi.org/10.1016/j.isatra.2018.07.040Vilanova, R., Visioli, A., 2012. PID Control in the Third Millenium - Lessons Learned and New Approaches. Springer-Verlag London Limited. https://doi.org/10.1007/978-1-4471-2425-2Visioli, A., 2001. Optimal tuning of PID controllers for integral and unstable processes. IEE Proceedings. Part D 148 (2), 180 - 184. https://doi.org/10.1049/ip-cta:20010197Zhuang, M., Atherton, D. P., 1993. Automatic tuning of optimum PID controllers. IEE Proc. Part D 140 (3), 216-224. https://doi.org/10.1049/ip-d.1993.0030Ziegler, J. G., Nichols, N. B., 1942. Optimum settings for automatic controllers. Trans. Am. Soc. Mech. Eng. 64, 759-768