Photovoltaic System Regulation Based on a PID Fuzzy Controller to Ensure a Fixed Settling Time

El objetivo principal de controlar los sistemas fotovoltaicos (PV) es asegurar la máxima extracción de potencia disponible. Estos controladores usualmente combinan la acción de un algoritmo de seguimiento del punto de máxima potencia (MPPT) con un regulador de tensión, el cual tiene la función de rechazar las perturbaciones en los terminales del panel. Estos controladores se basan comúnmente en estructuras PI-PID que requieren modelos linealizados alrededor del punto de operación. Pero, debido a perturbaciones generadas por el ambiente y la carga, el punto de operación cambia drásticamente, lo que dificulta obtener el desempeño deseado. Este artículo propone regular el sistema PV utilizando un controlador Fuzzy-PID, el cual se adapta a los cambios de irradiancia solar y oscilaciones en la carga. Esta característica garantiza un tiempo de establecimiento constante, el cual se requiere para definir de forma precisa el periodo del algoritmo MPPT. En el caso de controladores lineales, el periodo del MPPT se fija en el peor caso (periodo más largo), lo cual genera pérdidas de potencia adicionales al disminuir la velocidad del seguimiento del punto de operación óptimo. La solución propuesta en este artículo mejora la eficiencia general del sistema. Finalmente, la solución se valida con simulaciones en Matlab®.The main objective of the controllers in photovoltaic systems (PV) is to ensure the maximum extraction of the available power. Those controllers usually combine the action of a maximum power point tracking algorithm (MPPT) with a voltage regulator, which has the function of rejecting disturbances at the panel terminals. Such controllers are commonly based on PI and PID structures, it requiring linearized models at an operating point. But, due to disturbances generated by the environment and the load, the operating point of the system changes drastically, which hinder to obtain the desired system performance. This paper proposes to regulate the PV system using a Fuzzy PID controller, which adapts to changes in solar irradiance and load oscillations. This characteristic guarantees a constant settling time, which is required to precisely define the period of the MPPT algorithm. In the case of classical linear controllers, the period of the MPPT algorithm is set to the worst case (longest period) which generates additional power losses by slowing down the tracking of the optimal operating point. Therefore, the solution proposed in this paper improves the overall system efficiency. Finally, such a solution is validated through simulations in Matlab®

Static Model of Cement Rotary Kiln

En este trabajo, se presenta un modelo estático de un horno rotatorio de cemento. El modelo del sistema se obtiene a través de series de polinomio. El modelo propuesto se verifica con datos reales de la planta, donde se obtuvieron resultados óptimos. Los resultados esperados son medidos con respecto a la producción de Clinker. El consumo de combustible se mide en relación con el consumo calorífico. Los resultados esperados del enfoque es el incremento de los beneficios de la empresa a través de la reducción en el consumo de combustible.In this paper, a static model of cement rotary kilns is proposed. The system model is obtained through polynomial series. The proposed model is contrasted with data of a real plant, where optimal results are obtained. Expected results are measured with respect to the clinker production and the combustible consumption is measured in relation with the consumption calorific. The expected result of the approach is the increase of the profitability of the factory through the decrease of the consumption of the combustible

Modelo Matemático para un Vehículo Aéreo no Tripulado de Ala Fija, Usando un Estimador de Parámetros “Filtro de Kalman”

En este trabajo se plantea un modelo matemático para un Vehículo Aéreo no Tripulado (UAV) que está desarrollando la Universidad Pontificia Bolivariana (UPB) en el grupo de investigación en automática y diseño (A+D) dentro del macro proyecto “Desarrollo de un vehículo aéreo no tripulado de ala fija para inspección y vigilancia (AURA)”. Para desarrollar el modelo de la aeronave, se siguieron dos pasos: En el primero se obtuvieron las ecuaciones dinámicas que rigen el comportamiento de la aeronave en términos de coeficientes aerodinámicos que dependen de las características de la aeronave en particular. En el segundo paso se encontró el valor de estos parámetros utilizando un filtro extendido de Kalman.On this work a mathematical model is presented for an UAV that is being developed in UPB (Pontifical Bolivarian University)for the Automatics and Design investigation group (A+D), in the project “Design of a fixed wing unmanned flying vehicle for inspection and vigilance (AURA)”. In order to develop the UAV model, two steps were followed: On the first one, the mathematical equations describing aircraft behavior were gotten, in terms of aerodynamical coefficients, depending on particular aircraft characteristics. On the second step, the values of these coefficients were found using an extended Kalman filter

Assessment of a didactic strategy for teaching and learning software modeling using project Zero

El objetivo del presente artículo es presentar el procedimiento de valoración de una estrategia lúdica innovadora, basada en un software informático sobre plataforma de internet, la cual sirve para la enseñanza y aprendizaje del modelado de software en un curso básico de Ingeniería de Software. Esto se fundamenta en la Enseñanza para la Comprensión EpC, la Teoría de la actividad y Teoría de juegos, valorada a través del Proyecto Zero de la Universidad de Harvard, para desarrollar en el estudiante las competencias de modelado utilizando el enfoque orientado a objetos. Definida la necesidad de la utilización de internet para mejorar las estrategias de enseñanza y aprendizaje, el equipo utilizó un esquema para la valoración de juegos serios a través de un experimento controlado utilizando un grupo de control, un grupo experimental y un equipo de expertos.Los resultados obtenidos demuestran que los juegos serios desarrollados en plataforma de internet potencializan de manera más adecuada la representación y comprensión conceptual del tema de interacción entre objetos, específicamente los diagramas de secuencia, en comparación a los juegos de escritorio.The aim of this article is to present the assessment procedure of an innovative game strategy based on computer software internet platform, which is used for teaching and learning the software modeling in a basic course in software engineering. This is based on the Teaching for Understanding EPC, the activity Theory and Game Theory, valued through the Project Zero at Harvard University, to develop in the student the competence of modeling using the object-oriented approach. Defined the need of the using the internet to improve teaching and learning strategies; the team used a scheme for evaluating serious games through a controlled experiment using a control group, an experimental group and a team of experts. The results obtained showed that serious games developed in the Internet platform more adequately potentiate the representation and conceptual understanding of the topic of interaction between objects, specifically the sequence diagrams, compared to desktop games

Design Robust Controller for Rotary Kiln

En este artículo se presenta el diseño de un controlador robusto para un horno rotativo. El controlador diseñado es una combinación de un PID fraccionario y un regulador cuadrático lineal (LQR por su sigla en inglés, Linear Quadratic Regulator), los cuales no se han usado, hasta ahora, para controlar un horno rotatorio, además se evalúan los criterios de robustez (margen de ganancia, margen de fase, robustez de ganancia, sensibilidad y rechazo de ruido de alta frecuencia) aplicados al modelo completo (controlador-planta), obteniendo óptimos resultados en un rango de frecuencia de 0.020 a 90 rad/s, lo cual contribuye con la robustez del sistema.This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR), these are not used to control the kiln until now, in addition robustness criteria are evaluated (gain margin, phase margin, strength gain, rejecting high frequency noise and sensitivity) applied to the entire model (controller-plant), obtaining good results with a frequency range of 0.020 to 90 rad/s, which contributes to the robustness of the system

CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio