Análisis de un receptor solar térmico de gas

El objetivo de este documento es realizar un modelo matemático de un receptor solar de concentración. Para ello, primero se ha realizado un estudio de las diferentes tecnologías de captación solar. Se ha hecho un análisis desde el punto de vista teórico de cada una de dichas tecnologías. Por otro lado, se ha seleccionado un tipo de receptor solar, y se ha estudiado más a fondo. Se ha realizado un modelo matemático de este receptor y se ha simulado en una herramienta informática. Por último, se ha comprobado, gracias a dicha herramienta informática, que el modelo que se ha realizado está bien planteado y que cuando se varían parámetros importantes, el sistema responde como debiera en la realidad.The aim of this document is to perform a mathematical model of a specific concentrating solar receiver. First, a study of different solar collectors has been carried out. Those technologies have been analysed in a theoretical way. On the other hand, a specific type of receiver has been selected and studied more thoroughly. This receiver has been mathematical modeled and simulated in a software tool. Finnaly, it has been checked, thaks to a software tool, that the model is well designed. With that software, some parameters were changed and it can be checked that the model respod as it should in reality.Universidad de Sevilla. Máster en Sistemas de Energía Térmic

Flexure Strength and Fracture Propagation in Zirconia Ceramic Composites with Exfoliated Graphene Nanoplatelets

In this work, the flexure strength and fracture propagation mechanisms in yttria tetragonal zirconia (3YTZP) dense composites with 1 and 5 vol.% exfoliated graphene nanoplatelets (e-GNP) were assessed. The composite powders were processed by dry planetary ball milling to exfoliate the as-received GNP, and then densified by spark plasma sintering (SPS). The hardness and Young’s modulus were measured by Vickers indentation and the impulse-echo technique, respectively. Flexural strength and modulus were estimated by four-point bending tests. Finally, cracks originated by Vickers indentations were analyzed by scanning electron microscopy (SEM). The Raman spectra and SEM observations showed a reduction in the number of graphene layers and most remarkably in the lateral size of the e-GNP, achieving a very homogeneous distribution in the ceramic matrix. The hardness, elastic modulus, and flexural strength of the 3YTZP matrix did not vary significantly with the addition of 1 vol.% e-GNP, but they decreased when the content increased to 5 vol.%. The addition of e-GNP to 3YTZP increased its reliability under bending, and the small lateral size of the e-GNP produced isotropic fracture propagation. However, the energy dissipation mechanisms conventionally attributed to the larger GNP such as fracture deflection or blocking were limited.Ministerio de Economía y Competitividad MAT 2015-67889-PMinisterio de Ciencia, Innovación y Universidades PGC 2018–101377–B-10

Analysis of the mudejar polychrome decoration of the Patio de las Doncellas. Interventions carried out throughout its history

Este trabajo se centra en el estudio de la policromía del Patio de las Doncellas en el Palacio de Pedro I (1356-1366), conjunto situado en el Real Alcázar de Sevilla. La decoración de este espacio ha tenido en su historia numerosas intervenciones, adaptándose a las modas y gustos de sus habitantes, lo que ha provocado un aspecto de las superficies actuales que difiere del original. Con el objetivo de identificar las diferentes policromías y de situarlas cronológicamente, a partir del análisis documental, trabajo de campo y estudio analítico, se ha llevado a cabo una investigación exhaustiva de las yeserías y el alfarje.Este trabalho centra-se no estudo da policromia do Patio de las Doncellas no Palácio de Pedro I (1356-1366), um complexo situado no Real Alcázar de Sevilha. A decoração deste espaço sofreu numerosas intervenções ao longo da sua história, adaptando-se à moda e aos gostos dos seus habitantes, o que levou a um aspecto actual das superfícies que difere do aspecto original. Com o objectivo de identificar as diferentes policromias e situá-las cronologicamente, foi realizada uma investigação exaustiva do reboco e do alfarje, com base na análise documental, trabalho de campo e estudo analítico.This work focuses on the study of the polychrome decoration of the Patio de las Doncellas in the Palace of Pedro I (1356-1366), part of the Real Alcázar de Sevilla ensemble. The decoration of this space has undergone many interventions throughout its history to adapt to the fashions of the time. Therefore, the current surfaces seen nowadays look nothing alike their original appearance. With the aim of identifying the different polychromies and chronologically dating them, an exhaustive research on the plasterwork and wooden decoration (carved-alfarje and not carved-freeze) has been carried out based on documentary research, fieldwork and analytical studies.Ministerio de Economía y Competitividad (FEDER) (HAR2015-66139-P)Ministerio de Innovación y Ciencia (HAR 2011-27598)(PID2019-105706GB-100

Terminal restriction fragment length polimorphism (T-RFLP) : una herramienta útil para valorar la dinámica y la diversidad de la población microbiana en aves y cerdos

El ecosistema intestinal es un medio complejo y dinámico que puede verse afectado puntualmente por numerosos factores propios del individuo pero también por numerosos factores ambientales o externos (como puede ser la dieta). La necesidad de conocer de una forma rápida y reproducible cómo es la dinámica de la población bacteriana, así como su estructura está siendo posible gracias al desarrollo de técnicas moleculares aplicadas como DGGE (Denaturing Gradient Gel Electrophoresis)1, TGGE (Temperatura Gradient Gel Electrophoresis)2, SSCP (Single Strand Conformation Polimorphism)3 y T-RFLP (Terminal Restriction Fragment Length Polimorphism)4. Estas técnicas moleculares aprovechan la característica de universalidad del gen que codifica para el 16S ARNr, presente en prácticamente la totalidad de las especies bacterianas. La presencia de secuencias altamente conservadas hace posible el diseño de primers o cebadores que permitan la amplificación mediante PCR del total de la población bacteriana de la muestra. Son las regiones variables (polimórficas) del gen que codifica el 16S ARNr las que se aprovechan para la diferenciación. En el T-RFLP, estas diferencias entre especies o géneros bacterianos se ponen de manifiesto tras la digestión con endonucleasas de restricción del producto de PCR marcado. Únicamente el fragmento del extremo terminal será visible por electroforesis capilar gracias al mareaje fluorescente de uno de los cebadores. El perfil que se genera (electroferograma) nos permite obtener información del número de fragmentos (riqueza), de su tamaño en pares de bases (bp) (para una posible inferencia de la especie bacteriana presente) y de su altura (lo que puede orientar sobre la importancia de un determinado grupo bacteriano dentro de una muestra), siempre sin olvidar las desviaciones inherentes propias de la PCR. Es posible también calcular la frecuencia de detección de un determinado pico (especie) respecto al total de muestras así como construir con ayuda de programas informáticos matrices de similitud o dendogramas. Empleando herramientas disponibles en la red como: TAP-tRFLP del software Ribosomal Database Project II o ISPaR del software MiCA (Microbial Community Analysis) es posible hacer una asignación teórica de la especie o género bacteriano a cada uno de los picos en base a las secuencias depositadas por otros autores. Sin embargo un mismo pico puede tener su origen en distintas especies. Disponer alternativamente de secuencias propias obtenidas tras la clonación del 16S ARN de muestras de nuestros animales nos permite hacer una asignación teórica más firme, considerando únicamente aquellas especies mayoritarias encontradas

Impact of the historical introduction of exotic fishes on the chironomid community of Lake Azul (Azores Islands)

Little is known about the effect of top predator introduction in historically fishless communities, especially on remote islands. This issue is important because it might strongly affect climate reconstructions derived from biota assemblages such as chironomids. Head capsule larval remains of chironomids have been studied in a 660 years lacustrine sedimentary sequence from Lake Azul (Sao Miguel Island, Azores archipelago) to assess the extent and timescale of the effect of the predator introduction occurring in this historically fishless lake. Analysis of similarity showed that the chironomid assemblage was statistically different before and after predator introduction (R = 0.78; p < 0.001). Abundance of chironomids was about 40% greater in the fishless lake period compared to the period in the presence of predator. Results show major change in chironomid assemblage coinciding with the first time of goldfish introduction (around 1790 CE), followed by carp (1890 CE) and pike (1979 CE) introductions. The composition of feeding group guilds changed following a pattern characterized by a decrease in abundance of detritivorous and predaceous taxa and an increase in abundance of grazing chironomid taxa. This study suggests that predator introduction was the most important factor affecting the chironomid assemblages in this natural, Azorean fishless lake, but predators did not affect all chironomid species. Other external forcings like major climate oscillations, anthropogenic activities in the catchment basin, and volcanic eruptions seem to play an additional role. The latest stage of the warm and arid Medieval Climate Anomaly (1000-1300 CE) favoured the occurrence of some warm-adapted chironomid taxa, which were absent through the Little Ice Age (ca. 1450-1850 CE) cool period

The Effects of an Infant Formula Enriched with Milk Fat Globule Membrane, Long-Chain Polyunsaturated Fatty Acids and Synbiotics on Child Behavior up to 2.5 Years Old: The COGNIS Study

Although early life nutrition influences brain development and mental health, the long-term e ects of supplemented infant formula on children´s behavior remain unclear. We analyzed the e ects of a bioactive nutrients-enriched-infant formula on children’s behavior up to 2.5 years, compared to a standard infant formula or breastfeeding. Current analysis involved 70 children who were fed a standard infant formula (SF, n = 29) or a bioactive compounds enriched-infant formula (EF, n = 41), during their first 18 months of life, and 33 breastfed (BF) children (reference group) participating in the COGNIS study. Behavioral problems were evaluated using the Child Behavior Checklist at 18 months and 2.5 years. Di erent statistical analyses were performed using SPSS. EF children aged 2.5 years presented fewer pathological a ective problems than SF children. Besides, SF children were classified more frequently as bordering on internalizing problems than BF children. Rates of externalizing problems were increased in SF infants compared to EF and BF infants. Higher maternal IQ was found to have beneficial e ects on internalizing and total problem rate in their o spring at 18 months of life; finally, higher maternal educational level was related with fewer ADHD problems in children at 18 months, as well as internalizing, externalizing, total and anxiety problems in children aged 2.5 years. Our analysis suggests that enriched infant formula fed infants seem to show fewer behavioral problems up to 2.5 years compared to a standard infant formula-fed infants. In addition to type of early feeding, maternal IQ and educational level seem to play a key role on children behavioral development.Ordesa LaboratoriesS.L. Contract University of Granada General Foundation 3349SMARTFOODS (CIEN) Contract University of Granada General Foundation 4003Spanish Ministry of Economy, Industry and CompetitivenessHORIZON 2020 EU DynaHEALTH Project 633595Fundación Carolina, Madrid, SpainCatedra ORDESA-University of Granada, Spain as part of Special Issue "Early Nutrition and Re-programming of Health and Disease

Metoprolol in Critically Ill Patients With COVID-19.

Severe coronavirus disease-2019 (COVID-19) can progress to an acute respiratory distress syndrome (ARDS), which involves alveolar infiltration by activated neutrophils. The beta-blocker metoprolol has been shown to ameliorate exacerbated inflammation in the myocardial infarction setting. The purpose of this study was to evaluate the effects of metoprolol on alveolar inflammation and on respiratory function in patients with COVID-19-associated ARDS. A total of 20 COVID-19 patients with ARDS on invasive mechanical ventilation were randomized to metoprolol (15 mg daily for 3 days) or control (no treatment). All patients underwent bronchoalveolar lavage (BAL) before and after metoprolol/control. The safety of metoprolol administration was evaluated by invasive hemodynamic and electrocardiogram monitoring and echocardiography. Metoprolol administration was without side effects. At baseline, neutrophil content in BAL did not differ between groups. Conversely, patients randomized to metoprolol had significantly fewer neutrophils in BAL on day 4 (median: 14.3 neutrophils/µl [Q1, Q3: 4.63, 265 neutrophils/µl] vs median: 397 neutrophils/µl [Q1, Q3: 222, 1,346 neutrophils/µl] in the metoprolol and control groups, respectively; P = 0.016). Metoprolol also reduced neutrophil extracellular traps content and other markers of lung inflammation. Oxygenation (PaO2:FiO2) significantly improved after 3 days of metoprolol treatment (median: 130 [Q1, Q3: 110, 162] vs median: 267 [Q1, Q3: 199, 298] at baseline and day 4, respectively; P = 0.003), whereas it remained unchanged in control subjects. Metoprolol-treated patients spent fewer days on invasive mechanical ventilation than those in the control group (15.5 ± 7.6 vs 21.9 ± 12.6 days; P = 0.17). In this pilot trial, intravenous metoprolol administration to patients with COVID-19-associated ARDS was safe, reduced exacerbated lung inflammation, and improved oxygenation. Repurposing metoprolol for COVID-19-associated ARDS appears to be a safe and inexpensive strategy that can alleviate the burden of the COVID-19 pandemic.Mr Clemente-Moragón is supported by a fellowship from the Ministerio de Ciencia e Innovación (FPU2017/01932). The CNIC is supported by the ISCIII, the Ministerio de Ciencia e Innovación, and the Pro CNIC Foundation. Dr Ibáñez is supported by the European Commission (ERC-CoG grant No 819775) and by the Spanish Ministry of Science and Innovation (MCN; “RETOS 2019” grant No PID2019- 107332RB-I00). Dr Oliver is supported by funds from the Comunidad de Madrid Programa de Atracción de Talento (2017-T1/BMD-5185). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S

Highly Anisotropic Organometal Halide Perovskite Nanowalls Grown by Glancing-Angle Deposition

Polarizers are ubiquitous components in current optoelectronic devices as displays or photographic cameras. Yet, control over light polarization is an unsolved challenge, since the main drawback of the existing display technologies is the significant optical losses. In such a context, organometal halide perovskites (OMHP) can play a decisive role given their flexible synthesis with tunable optical properties such as bandgap and photoluminescence, and excellent light emission with a low non-radiative recombination rate. Therefore, along with their outstanding electrical properties have elevated hybrid perovskites as the material of choice in photovoltaics and optoelectronics. Among the different OMHP nanostructures, nanowires and nanorods have lately arisen as key players in the control of light polarization for lighting or detector applications. Herein, the fabrication of highly aligned and anisotropic methylammonium lead iodide perovskite nanowalls by glancing-angle deposition, which is compatible with most substrates, is presented. Their high alignment degree provides the samples with anisotropic optical properties such as light absorption and photoluminescence. Furthermore, their implementation in photovoltaic devices provides them with a polarization-sensitive response. This facile vacuum-based approach embodies a milestone in the development of last-generation polarization-sensitive perovskite-based optoelectronic devices such as lighting appliances or self-powered photodetectors

Application of edible nanolaminate coatings with antimicrobial extract of Flourensia cernua to extend the shelf-life of tomato (Solanum lycopersicum L.) fruit

Supplementarymaterialrelatedtothisarticlecanbefound,inthe online version, at doi:https://doi.org/10.1016/j.postharvbio.2018.12. 008.Edible coatings have potential to reduce postharvest losses of fruit such as tomato. In this study, the effects of nanolaminate coatings incorporated with extracts of Flourensia cernua, an endemic plant of the arid and semi-arid regions of Mexico, has been investigated. Ethanol extracts of F. cernua (FcE) were prepared and incorporated into polyelectrolyte solutions of alginate and chitosan. The nanolaminates were characterized by determining the zeta potential, contact angle and water vapor and oxygen permeabilities. Shelf-life analyses (20°C for 15 d) were carried out with uncoated fruit (UCF), nanolaminate coating (NL) and nanolaminate coating with FcE (NL+FcE). Physicochemical analyses, gas exchange rates of O2 and CO2 and ethylene production, as well as microbiological analyses of treated fruit were measured. Zeta potential and contact angle measurements confirmed the successful assembly of successive nanolayers of alginate and chitosan, as well as those with F. cernua. The nanolaminate coatings resulted in decreased permeabilities to water and O2. The best treatment of NL+FcE, extended the shelf-life of fruit by reducing weight loss and microbial growth, reducing gas exchange and ethylene production, and maintaining firmness and color. The NL+FcE treatment are an alternative to extend the shelf-life of tomato fruit.Author E. de J. Salas-Méndez thanks Mexican Science and Technology Council (CONACYT, Mexico) for PhD fellowship support. Authors want to thank PhD Zlatina Genisheva for the proof reading of the manuscript and suggestions to the same; also, to:MaríaGuadalupe Moreno Esquivel, Edith E. Chaires Colunga, Olga L. Solís Hernández and M. Leticia Rodríguez González of the Phytochemistry Laboratory from Universidad Autónoma Agraria Antonio Narro, for their assistance in obtaining extracts and chemical composition.info:eu-repo/semantics/publishedVersio