Contribution of a pumped-storage hydropower plant to reduce the scheduling costs of an isolated power system with high wind power penetration

AbstractThe paper aims at demonstrating that the consideration of constant start-up costs and ramps of the thermal generating units for assessing the contribution of pumped-hydro energy storage to reduce the scheduling costs of hydrothermal power systems with high wind penetration, may yield unrealistic results. For this purpose, an isolated power system is used as a case study. The contribution of a pumped-storage hydropower plant to reduce the system scheduling costs is assessed in the paper by using a hydrothermal weekly unit commitment model. The model considers different start-up costs and ramps of the thermal generating units as a function of the start-up type. The effects of including pumped hydro energy storage in the system on the integration of wind energy, and on the start-ups and capacity factors of the thermal generating units are also evaluated. The results of the paper demonstrate that the consideration of constant start-up costs and ramps of the thermal generating units yields unrealistic results, and that the pumped-storage hydropower plant may help reduce the system scheduling costs by 2.5–11% and integrate wind power and may allow dispensing with some inflexible thermal generating units

Corrección de consolidación viciosa diafisaria de fémur: osteotomía en caparazón. A propósito de dos casos.

La adecuada alineación del miembro inferior es esencial para el adecuado reparto de cargas que permita una deambulación sin alteraciones. Por lo que a la hora del tratamiento de fracturas de huesos largos del miembro inferior, fundamentalmente fémur y tibia, habrá que evitar cualquier deformidad angular que a medio plazo provoque fenómenos degenerativos en las articulaciones adyacentes. Se presentan dos casos clínicos complejos, en los que se corrigieron sendas consolidaciones viciosas de fracturas diafisarias de fémur satisfactoriamente, mediante osteotomía tipo caparazón o clamshellThe lower limb alignment is essential to share correctly the bearing weight of the body to allow a suitable gait. We should take it into account when treating femoral and tibial diaphyseal fractures, in order to avoid angular deformities which could lead to degenerative changes in adjacent joints. We report two complex cases, with femoral shaft malunions corrected satisfactorily by using a clamshell osteotom

Las Especies sudamericanas del género "Neralsia" Cameron, 1883 (Hymenoptera: Cynipoidea: Figitidae: Figitinae): estudio del material tipo

Les espècies sud-americanes del gènere Neralsia Cameron, 1883 (Hymenoptera: Cynipoidea: Figitidae: Figitinae): estudi del material tipus Neralsia Cameron, 1883, és un gènere de distribució americana present tant a la regió neàrtica com neotropical. Aquest treball és la primera contribució taxonòmica que fem del gènere. Fa referència a l'estudi de les 12 espècies descrites de Neralsia a Sud-amèrica. Neralsia fiebrigi Hedicke, 1914, N. ciliatinervis (Kieffer, 1910) i N. acuminata (Dettmer, 1932) han de ser considerades com incertae sedis. S'estableix la sinonímia entre N. splendens (Borgmeier, 1935) i N. fossulata (Kieffer, 1909). Es transfereix Xyalophora albipennis Kieffer, 1909, al gènere Neralsia, N. albipennis (Kieffer, 1909) n. comb. Per tot això, es consideren vàlides vuit espècies: N. albipennis (Kieffer, 1909), N. bogotensis (Kieffer, 1909), N. claripennis (Dettmer, 1932), N. fossulata (Kieffer, 1909), N. flavidipennis (Kieffer, 1909), N. pilosa (Borgmeier, 1935), N. striaticeps (Kieffer, 1909) i N. suffecta (Dettmer, 1932). Es redescriuen aquestes espècies ja que les descripcions dels autors anteriors presenten, en general, deficiències diagnòstiques.Neralsia Cameron, 1883, es un género de distribución americana presente tanto en la región neártica como neotropical. Este trabajo es la primera contribución taxonómica que realizamos del género. Se refiere al estudio de las 12 especies descritas de Neralsia en Sudamérica. Neralsia fiebrigi Hedicke, 1914, N. ciliatinervis (Kieffer, 1910) y N. acuminata (Dettmer, 1932) han de ser consideradas como incertae sedis. Se establece la sinonimia entre N. splendens (Borgmeier, 1935) y N. fossulata (Kieffer, 1909). Se transfiere Xyalophora albipennis Kieffer, 1909, al género Neralsia, N. albipennis (Kieffer, 1909) n. comb. Por todo ello, se consideran válidas ocho especies: N. albipennis (Kieffer, 1909), N. bogotensis (Kieffer, 1909), N. claripennis (Dettmer, 1932), N. fossulata (Kieffer, 1909), N. flavidipennis (Kieffer, 1909), N. pilosa (Borgmeier, 1935), N. striaticeps (Kieffer, 1909) y N. suffecta (Dettmer, 1932). Se redescriben dichas especies puesto que las descripciones de los autores anteriores presentan, por lo general, deficiencias diagnósticas.The South American species of the genus Neralsia Cameron, 1883 (Hymenoptera: Cynipoidea: Figitidae: Figitinae): a study of the type material The genus Neralsia Cameron, 1883, has an American distribution and it is present in both Neotropical and Nearctic regions. The present work is our first contribution to the taxonomy of this genus and deals with the 12 species of Neralsia described from South America. Of these, Neralsia fiebrigi Hedicke, 1914, Neralsia ciliatinervis (Kieffer, 1910) and Neralsia acuminata (Dettmer, 1932) have to be considered «incertae sedis». The synonymy of Neralsia splendens (Borgmeier, 1935) and N. fossulata (Kieffer, 1909) is established. The species Xyalophora albipennis Kieffer, 1909, is transferred to Neralsia as N. albipennis (Kieffer, 1909) n. comb. In conclusion, 8 of the 12 previously known species are considered valid: N. albipennis (Kieffer, 1909), N. bogotensis (Kieffer, 1909), N. claripennis (Dettmer, 1932), N. fossulata (Kieffer, 1909), N. flavidipennis (Kieffer, 1909), N. pilosa (Borgmeier, 1935), N. striaticeps (Kieffer, 1909) and N. suffecta (Dettmer, 1932). These species are redescribed here because the original descriptions generally have diagnostic deficiencies

Estudio en CFX de la distribución de temperatura en el tanque de calandria de la Central Nuclear Embalse

En este trabajo se presentan los cálculos de las distribuciones de temperatura y velocidad del fluido en el recipiente del moderador (calandria de ahora en más) de un reactor tipo CANDU-6, mediante simulaciones en estado estacionario con el software ANSYS CFX 15.0, versión académica. El recipiente de la calandria contiene 380 tubos de calandria que, a su vez, incluyen los tubos de presión y el combustible. Adicionalmente, dentro de la calandria se encuentran los internos del reactor que, para esta etapa de cálculo, no fueron tenidos en cuenta. La geometría se representó a partir de los planos correspondientes al recipiente del moderador y el de sus internos, y como condiciones decontorno se establecieron el caudal de entrada, la presión de salida, y la potencia por moderación y por conducción distribuida radial y axialmente. Finalmente, los resultados obtenidos permitieron demostrar que el modelo en CFX del tanque de calandria posibilitó identificar y representar patrones de flujo determinados experimentalmente y por otros modelos en fluidodinámica computacional (CFD por sus siglas en ingles). Además se determinó que para las condiciones de operación del reactor CANDU-6 el patrón de flujo que domina la distribución de flujo dentro del tanque de calandria es de tipo flujo mixto caracterizado por corrientes de flujo dominadas por fuerzas de momento y por fuerzas boyantes.Publicado en: Mecánica Computacional vol. XXXV no.31Facultad de Ingenierí

Effect of water composition on catalytic reduction of nitrate

This work studies catalytic reduction of nitrate with bimetallic catalysts supported on γ-alumina (Pd-Sn/Al2O3 and Pd-In/Al2O3). Pd-Sn/Al2O3 yielded higher NO3− conversion and selectivity towards N2 than Pd-In/Al2O3 in synthetic water (deionized water with 100 mg/L NO3−). The Pd-Sn/Al2O3 catalyst showed highly stable behaviour, without signs of deactivation upon ten consecutive runs of 6 h each, where almost equal low selectivity to NH4+ (absence of NO2−) was maintained at high nearly constant nitrate conversion (≈ 90%). The presence of anions (Cl−, SO42− and HCO3−) in the reaction medium decreased NO3− conversion and the selectivity towards N2. Chloride showed a moderately negative effect at relatively low concentration. The effect of SO42− and HCO3− was more pronounced, being the second the most detrimental to the catalytic activity. The selectivity towards N2 was also negatively affected by the presence of those anions following the sequence HCO3− > SO42− > Cl−. However, the joint presence of Cl− or SO42− with HCO3− reduced the negative effect of the latter. The Pd-Sn/Al2O3 catalyst also showed high activity in NO3− reduction from drinking waters of weak mineralization, with a slightly increase of the selectivity towards NH4+ with respect to the obtained in deionized water with NO3− as the only anionThe authors wish to thank for the financial support the Spanish MINECO ( PID2019-108445RB-I00 ) and Comunidad de Madrid ( BIOTRES-CM , S2018/EMT-4344 ). I. Sanchis also thanks Comunidad de Madrid for award of a research grant ( PEJD-265 2017-PRE/AMB-4616

Cannabinoid CB₂ Receptor Modulation by the Transcription Factor NRF2 is Specific in Microglial Cells

Nuclear factor erythroid 2-related factor 2 (NRF2) is a pleiotropic transcription factor that has neuroprotective and anti-inflammatory effects, regulating more than 250 genes. As NRF2, cannabinoid receptor type 2 (CB2) is also implicated in the preservation of neurons against glia-driven inflammation. To this concern, little is known about the regulation pathways implicated in CB2 receptor expression. In this study, we analyze whether NRF2 could modulate the transcription of CB2 in neuronal and microglial cells. Bioinformatics analysis revealed an antioxidant response element in the promoter sequence of the CB2 receptor gene. Further analysis by chemical and genetic manipulations of this transcription factor demonstrated that NRF2 is not able to modulate the expression of CB2 in neurons. On the other hand, at the level of microglia, the expression of CB2 is NRF2-dependent. These results are related to the differential levels of expression of both genes regarding the brain cell type. Since modulation of CB2 receptor signaling may represent a promising therapeutic target with minimal psychotropic effects that can be used to modulate endocannabinoid-based therapeutic approaches and to reduce neurodegeneration, our findings will contribute to disclose the potential of CB2 as a novel target for treating different pathologies.This work was supported by the Spanish Ministry of Economy and Competitiveness (Grants Refs. SAF2016-76520-R to ILB and BFU2016-75973-R to MDG)

Germination ecology of the perennial Centaurium somedanum, a specialist species of mountain springs

To improve understanding of how a rare endemic species of Centaurium adapts to a specialized ecological niche, we studied the germination ecology of the mountain spring specialist, C. somedanum, a perennial species restricted to an unusual habitat for this genus. We conducted laboratory experiments with fresh seeds collected from two populations for three consecutive years, to investigate: (1) the effect of temperature and light ongermination; (2) the existence of seed dormancy; and (3) inter-population and inter-annual variation in germinability. Germination occurred only in the light and at relatively low temperatures (15?228C) with no differences between constant and alternating regimes, and a significant decrease at high temperatures (258C and 308C). We found non-deep simple morphophysiological dormancy and variation in seed germinability depending on the year of seed collection. C. somedanum diverged from the common germination characteristics of the genus in: (1) its germination at lower temperatures, which contrasts with what is generally expected in wetland species but could be adaptive in the spring habitat; and (2) its morphophysiological dormancy, which we report here for the first time in the genus and which could be an adaptation to its mountain habitat

Carbon based electrodes for the voltammetric determination of capsaicin in spicy samples

A voltammetric sensor based on the modification of a screen-printed carbon electrode with reduced graphene oxide (rGO-SPCE) is presented for the cyclic voltammetric determination of capsaicin in a wide range of concentrations. Special attention was given to factors affecting sensitivity and repeatability in order to overcome common reported issues related to the voltammetric determination of capsaicin. Fouling associated to the adsorption of capsaicin was minimized using a simple and effective washing step, allowing sensors to be reused for at least 10 measurements with a repeatable signal. The developed rGO-SPCE presented two well-defined linear ranges (from 1.1 to 25.0 and from 25.0 to 150.3 µmol L−1) and provided an increased sensitivity as compared to the unmodified electrode as well as to other modified electrodes based on carbon nanomaterials commercially available. Furthermore, a low limit of detection of 0.3 µmol L−1 was achieved and the accuracy of the method was demonstrated for the determination of capsaicin in chilli pepper, paprika samples and Tabasco sauce, obtaining comparable results to those achieved by liquid chromatography with UV-vis detection