467 research outputs found

    On the potential contribution of rooftop PV to a sustainable electricity mix: the case of Spain

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    This work evaluates the potential contribution of rooftop PV to the future electricity mix. Several sustainable scenarios are considered, each comprising different shares of centralized renewables, rooftop PV and storage. For each generation scenario, the storage capacity that balances the net hourly demand is determined, and the portfolio combination that minimizes the cost of supplying electricity is obtained. The analysis is applied to mainland Spain, using public information and detailed granular models, both in time (hourly resolution) and space (municipal level). For the Spanish case, when the flexibility of hydro and biomass generation is taken into account, the least-cost portfolio involves rather modest storage capacities, in the order of daily rather than seasonal values. This shows that a sustainable, almost emissions-free electricity system for Spain is possible, at a cost that can be even lower than current wholesale market prices.Comment: 7 tables & 11 figures in the main body (24 pages), and 13 pages for the supplementary material, wit

    Subcapsular hepatic hematoma post-endoscopic retrograde cholangiopancreatography: a case report and literature review

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    A 23-year-old female with a history of long-standing obesity, recently was diagnosed with cholelithiasis, along with a 15 day development of jaundice. An ERCP (endoscopic retrograde cholangiopancreatography) was performed, during which resulted an unsuccessful sphincterotomy, this was followed by placing a 7-centimeter, 10 French Amsterdam-type stent, subsequently she experienced sudden abdominal pain, and a CT scan revealed a subcapsular hepatic hematoma, which required surgical management. The objective was to describe a clinical case of subcapsular hepatic hematoma, clinical presentation, and therapeutic conduct. The treatment of subcapsular hepatic hematoma will depend on the patient's hemodynamic stability. However, survival is uncertain due to its rarity, making it crucial to recognize its early signs and symptoms and act promptly.

    El leasing como estrategia de financiamiento en el grupo C&R 11 consultores y constructores S.A.C., Chiclayo 2021

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    El estudio denominado “Leasing como estrategia de financiamiento en el grupo C&R 11 consultores y constructores S.A.C., Chiclayo, 2021”, ha permitido determinar de manera inequívoca, la pertinencia de acceder a este instrumento financiero para lograr una mejora en los procesos constructivos del negocio, incrementar sus ventas, racionalizar de manera adecuada los costos y los gastos operativos, y, por consiguiente, optimizar sus resultados. Asimismo, el estudio tuvo como finalidad evaluar el efecto que tendrá el Leasing en el aspecto financiero de la constructora, y que le permitirá a que cumpla de manera adecuada los objetivos a corto y mediano plazo. Por tales consideraciones, el problema de la investigación quedó formulado de la siguiente manera ¿Cuál será la incidencia del Leasing como estrategia de financiamiento en el grupo C&R 11 consultores y constructores S.A.C., Chiclayo, 2021? Por tanto, se planteó el objetivo de determinar la incidencia del Leasing como estrategia de financiamiento en el grupo C&R 11 consultores y constructores S.A.C. Se justifica el estudio porque permitió identificar y establecer de manera adecuada la incidencia que tiene el Leasing como estrategia de financiamiento en el grupo C&R 11 consultores y constructores S.A.C. La hipótesis señaló que el Leasing si es una eficaz estrategia de financiamiento para el grupo C&R 11 consultores y constructores S.A.C. En tanto la investigación fue del tipo Descriptiva, Correlacional, con un diseño No experimental y que permitieron operacionalizar debidamente las variables de estudio.TesisGestión empresarial y emprendimient

    Robustness of electricity systems with nearly 100% share of renewables: a worst-case study

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    Several research studies have shown that future sustainable electricity systems, mostly based on renewable generation and storage, are feasible with current technologies and costs. However, recent episodes of extreme weather conditions, probably associated with climate change, cast shades of doubt on whether the resulting generation portfolios are sufficiently robust to assure, at all times, a suitable balance between generation and demand, when adverse conditions are faced. To address this issue, this work elaborates a methodology intended to determine a sustainable electricity system that can endure extreme weather conditions, which are likely to occur. First, using hourly production and demand data from the last decade, along with estimates of new uses of electricity, a worst-case scenario is constructed, including the storage capacity and additional photovoltaic power which are needed to serve the demand on an hourly basis. Next, several key parameters which may have a significant influence on the LCOE are considered, and a sensitivity analysis is carried out to determine their real impact, significance and potential trends. The proposed methodology is then applied to the Spanish system. The results show that, under the hypotheses and conditions considered in this paper, it is possible to design a decarbonized electricity system that, taking advantage of existing sustainable assets, satisfies the long-term needs by providing a reliable supply at an average cost significantly lower than current market prices.Comment: 33 pages, 13 figures, 10 table

    Identification Of Mitotically Competent SOX2+ Cells In White Matter Of Normal Human Adult Brain

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    SOX2 expression is linked to the undifferentiated state of stem cells in mammalian neurogenic niches. While its expression has been reported in the adult human subventricular zone (SVZ), to date it has not been detected in adult human white matter. Here we describe a population of SOX2+ cells from the white matter of the adult human temporal lobe, which proliferate and express glial markers in vitro

    High-level expression of Pinus sylvestris glutamine synthetase in Escherichia coli Production of polyclonal antibodies against the recombinant protein and expression studies in pine seedlings

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    AbstractIn a previous work we reported the molecular characterization of a glutamine synthetase (GS; EC 6.3.1.2.) complementary DNA from a woody plant (Cantón et al. (1993) Plant Mol. Biol. 22, 819–828). The isolated cDNA (pGSP114) encoding a Scots pine (Pinus sylvestris) cytosolic subunit, has been subcloned into the expression vector pET3c to overproduce the GS polypeptide in Escherichia coli cells. The recombinant GS protein showed the same molecular size as a native Scots pine GS subunit. Antibodies against the pET3c-GSP114 encoded protein were raised in rabbits by injecting purified preparations and specificity was determined by immunoprecipitation of GS activity present in pine crude extracts. In spite of the antibodies were able to recognize both cytosolic and chloroplastic GS in tomato plants, they were unable to immunodetect chloroplastic GS in green cotyledons of pine seedlings and cytosolic GS was the unique recognized polypeptide. Unlike to that found in other plant species, cytosolic GS was strongly expressed in green tissues as determined by protein and Northern analysis. Our results suggest a key role for cytosolic GS in photosynthetic tissues of conifers

    Proyecto Colciencias UTP - Precisión en la extracción de tumores cerebrales

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    Video sobre la aplicación creada en el proyecto, busca dar a conocer la aplicación, así como sus ventajas en el tema tratado. contiene las ideas principales de su funcionamiento, y la validación médica plica.Minciencia

    Unveiling the effect of interacting forecasted abiotic factors on growth and aflatoxin B1 production kinetics by Aspergillus flavus

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    © 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/.The aim was to decipher the temporal impact of key interacting climate change (CC) abiotic factors of temperature (30 vs 37 °C), water activity (aw; 0.985 vs 0.930) and CO2 exposure (400 vs 1000 ppm) on (a) growth of Aspergillus flavus and effects on (b) gene expression of a structural (aflD) and key regulatory gene (aflR) involved in aflatoxin B1 (AFB1) biosynthesis and (c) AFB1 production on a yeast extract sucrose medium over a period of 10 days. A. flavus grew and produced AFB1 very early with toxin detected after only 48 h. Both growth and toxin production were significantly impacted by the interacting abiotic factors. The relative expression of the aflD gene was significantly influenced by temperature; aflR gene expression was mainly modulated by time. However, no clear relationship was observed for both genes with AFB1 production over the experimental time frame. The optimum temperature for AFB1 production was 30 °C. Maximum AFB1 production occurred between days 4–8. Exposure to higher CO2 conditions simulating forecasted CC conditions resulted in the amount of AFB1 produced in elevated temperature (37 °C) being higher than with the optimum temperature (30 °C) showing a potential for increased risk for human/animal health due to higher accumulation of this toxin.Peer reviewedFinal Accepted Versio

    Investigation of EBT3 radiochromic film’s response to humidity

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    Purpose: The aim of this work is to investigate the effects of immersing EBT3 radiochromic film in water and to evaluate its contribution to the total uncertainty in dose determination. Materials and methods: We used 3 cm 9 3 cm EBT3 radiochromic films irradiated in the range of 0–70 Gy to study the impact of water immersion on the change in net optical density. These films were placed in a water container for a period of 24 h. The net optical density was measured before (0 h) and after of the immersion in water (1, 3, 6, 12, 18, and 24 h). The absorbance spectrum of the EBT3 radiochromic film was measured at 0 h and 24 h after immersion in water. The uncertainty in dose determination due to the effects of keeping the EBT3 radiochromic film submerged in water at 0, 1, and 24 h were recorded in the red, green, and blue channels. Results: We observed an increase in the net optical density as an effect on the film due to its immersion in water. The penetration of the water at the edges of the radiochromic film was observed to be a function of time during which the film remained in the water. On the other hand, the penetration of water at the edges of the film was found to be independent of irradiation dose. Conclusions: EBT3 radiochromic film is found more resistant to water penetration through the edges than its predecessors. However, there is evidence that suggest that liquid water damage the Nylon cover layer of the film by changing its optical properties. Therefore, it is recommended to build a new calibration curve for radiochromic films for a specific situation involving dose measurements in liquid water.UAEMex INN
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