Corrección de la deriva en sistemas de seguimiento solar a través de control de lazo cerrado

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Los sistemas de seguimiento solar de dos ejes en aplicaciones de concentración solar requieren una mayor precisión en el seguimiento automático de la posición aparente del Sol, esto con el fin de mantener la radiación solar concentrada en una posición fija en el receptor del sistema, ya que una mínima variación se traduce en un desplazamiento (deriva) del spot de concentración de la zona de interés. Este trabajo se centra en la discusión de los métodos implementados para la solución de los problemas de deriva y corrección de los ángulos de elevación y acimut en los dispositivos de seguimiento solar. Para llevar a cabo la evaluación de la corrección de la deriva, se emplearon dos dispositivos de seguimiento solar de dos ejes de movimiento. Un Helióstato de 36 m2 (E3) ubicado en la Plataforma Solar de Hermosillo, Sonora, México. El segundo es un concentrador solar reflectivo de no imagen tipo Fresnel para la caracterización de celdas fotovoltaicas ubicado en el IER-UNAM en Temixco, Morelos, México. El análisis planteado en este documento se basa principalmente en la comparativa de los resultados obtenidos a partir de implementar una estrategia de control de lazo abierto y cerrado. El control de lazo abierto consiste en un código de programación que realiza el cálculo de la posición del Sol mediante algoritmos propuestos por distintos autores, y que permiten enviar señales de comando a los actuadores de los ejes de acimut y elevación en ambos dispositivos de seguimiento. Para la metodología de lazo cerrado se utiliza un sistema óptico de retroalimentación que trata de un dispositivo de visión (CCD) que permite observar la posición del Sol en tiempo real.ABSTRACT: Two axis solar tracking systems require high precision regarding automatic tracking of apparent sun position for solar concentration applications. This, with the aim of maintaining the concentrated solar radiation in a fixed position in the system´s receiver. This is so, because a minimum variation results in a deviation (drift) of the solar image concentrated in the area of interest. This work focuses on a discussion of implemented methods for solving drift problems and a correction of elevation and azimuth angles in solar tracking devices. Two sun tracking devices of two axes movement were used in order to evaluate drift correction. The first one was a 36 m2 heliostat (named E3), located in the Solar Platform in Hermosillo, Sonora, México. The second tracking device was a solar concentrator Fresnel type for characterizing photovoltaic cells (FRESNEL) located at IER-UNAM, Temixco, Morelos, México. The analysis of this document is mainly based on the comparison of obtained results from implementing an open-loop and close-loop control strategy. Open-loop control consists of a program code that calculates the Sun's position using algorithms suggested by different authors, it allows send command signals to elevation and azimuth axis actuators on both tracking devices. Closed-loop methodology uses an optical feedback system, which refers to a vision device (webcam) that allows observing in real time the Sun´s position.info:eu-repo/semantics/publishedVersio

Molecular basis of targeted therapy in T/NKcell lymphoma/leukemia: A comprehensive genomic and immunohistochemical analysis of a panel of 33 cell lines

T and NK-cell lymphoma is a collection of aggressive disorders with unfavorable outcome, in which targeted treatments are still at a preliminary phase. To gain deeper insights into the deregulated mechanisms promoting this disease, we searched a panel of 31 representative T-cell and 2 NK-cell lymphoma/leukemia cell lines for predictive markers of response to targeted therapy. To this end, targeted sequencing was performed alongside the expression of specific biomarkers corresponding to potentially activated survival pathways. The study identified TP53, NOTCH1 and DNMT3A as the most frequently mutated genes. We also found common alterations in JAK/STAT and epigenetic pathways. Immunohistochemical analysis showed nuclear accumulation of MYC (in 85% of the cases), NFKB (62%), p-STAT (44%) and p-MAPK (30%). This panel of cell lines captures the complexity of T/NK-cell lymphoproliferative processes samples, with the partial exception of AITL cases. Integrated mutational and immunohistochemical analysis shows that mutational changes cannot fully explain the activation of key survival pathways and the resulting phenotypes. The combined integration of mutational/expression changes forms a useful tool with which new compounds may be assayed

Response of Strawberry to the Substitution of Blue Light by Green Light in an Indoor Vertical Farming System

Indoor production systems with light emitting diode (LED) lamps are a feasible alternative for increasing strawberry productivity by reducing the incidence of pests and diseases and the damage caused by extreme weather events. Blue (BL) and red (RL) LED light are considered the most important light spectra for photosynthesis and crop yield; however, recent studies have demonstrated that the beneficial effects of green light (GL) have been underestimated. This information would be of particular importance for strawberry production in controlled-environments/vertical farming systems as it may lower input costs and enhance production efficiency and quality and marketability. The present study aimed to define the effect of GL in combination with BL in strawberry. A proportion of 20% GL (20% BL + 60% RL) of total photosynthetic photon flux density was beneficial for plant growth and productivity; however, a 27% GL (12% BL + 61% RL) proportion was detrimental or comparable to that with 6% GL (36% BL + 58% RF). Total dry mass increased 51% when plants were illuminated with 20% GL lamps compared to those with 6% GL; the most impacted plant part was the root as it increased by 155%. The higher yield was observed with GL at 20%, but further increasing GL to 27% resulted in reduced yield. GL at 20% and 27% exhibited higher photosynthesis but reduced transpiration, stomatic conductance, and internal CO2, which in turn increased instantaneous and intrinsic water-use efficiency. Plants with the highest yield (20% GL) exhibited lower total soluble solids in fruits but still the values obtained were acceptable (8.25 °Brix); these fruits contained a high total sugars and phenolics concentration but a reduced antioxidant scavenging capacity. High proportions of GL were associated with a higher leaf and fruit Ca and a higher leaf P and K, which may be due to the increased allocation of biomass to the roots. In conclusion, GL at 20% and BL at 20% resulted in the best growth and yield parameters, enhanced net photosynthesis rate, water-use efficiency and fruit quality attributes. The effects of GL observed in this study may also be important for other high-value horticultural crops suitable for indoor vertical farming