12,136 research outputs found

    Synthesis, characterization of a new carbonylated zirconium metallocene using a dichloro-zirconocene derived from partially alkylated s-indacene

    Get PDF
    Indexación: ScieloThis work describes the synthesis and characterization of new organometallic species, an unprecedented mononuclear zirconium complex bearing a tetraalkylated s-indacene ligand, and secondly, its respective dicarbonyl complex obtained by reduction with Mg/HgCl2. Theoretical calculations of these two compounds were carried out to gain further understanding of these novel molecular systems.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072009000300014&lng=es&nrm=is

    Combining offshore wind and solar photovoltaic energy to stabilize energy supply under climate change scenarios: A case study on the western Iberian Peninsula

    Get PDF
    La expansión de la energía renovable marina es una importante alternativa para la reducción de las emisiones de gases de efecto invernadero. Sin embargo, en Europa, la alta penetración de la energía eólica marina introduce intermitencia y variabilidad de energía en la red eléctrica existente. La energía solar fotovoltaica marina es otra alternativa tecnológica en consideración en los planes de descarbonización. Sin embargo, las futuras variaciones en el viento, la temperatura del aire o la radiación solar debido al cambio climático tendrán un gran impacto en los recursos de energía renovable. En este contexto, este estudio se centra en la evaluación de la energía marina en la costa de la Península Ibérica occidental, una región europea que abarca Portugal y la parte noroccidental de España. Utilizando una amplia fuente de datos de 35 simulaciones de un proyecto de investigación llamado CORDEX, este estudio investiga la complementariedad de las fuentes de energía eólica y solar marina con el objetivo de mejorar la estabilidad del suministro de energía de esta región hasta 2040. Aunque se ha demostrado que el recurso de energía eólica marina es mayor que el recurso fotovoltaico solar a escala anual, ambos recursos renovables mostraron una variabilidad significativa en energía a lo largo de la Península Ibérica occidental. Cuando se combinan ambas fuentes renovables, la estabilidad del recurso energético aumenta considerablemente a lo largo del año. El esquema propuesto de combinación de energía eólica y solar se evalúa mediante un método de clasificación de rendimiento llamado Delphi, teniendo en cuenta la estabilidad, el recurso, el riesgo y los factores económicos. El índice de clasificación total aumenta cuando la estabilidad del recurso se mejora mediante la consideración de la producción híbrida de energía eólica-fotovoltaica solar, especialmente a lo largo de las aguas cercanas a la costa.The expansion of marine renewable power is a major alternative for the reduction of greenhouse gases emissions. In Europe, however, the high penetration of offshore wind brings intermittency and power variability into the existing power grid. Offshore solar photovoltaic power is another technological alternative under consideration in the plans for decarbonization. However, future variations in wind, air temperature or solar radiation due to climate change will have a great impact on both renewable energy resources. In this context, this study focusses on the offshore energy assessment off the coast of Western Iberia, a European region encompassing Portugal and the Northwestern part of Spain. Making use of a vast source of data from 35 simulations of a research project called CORDEX, this study investigates the complementarity of offshore wind and solar energy sources with the aim of improving the energy supply stability of this region up to 2040. Although the offshore wind energy resource has proven to be higher than solar photovoltaic resource at annual scale, both renewable resources showed significant spatiotemporal energy variability throughout the western Iberian Peninsula. When both renewable resources are combined, the stability of the energy resource increased considerably throughout the year. The proposed wind and solar combination scheme is assessed by a performance classification method called Delphi, considering stability, resource, risk, and economic factors. The total index classification increases when resource stability is improved by considering hybrid offshore wind-photovoltaic solar energy production, especially along the nearshore waters.Ministerio de Economía, Industria y Competitividad | Ref. FJCI-2017-32577Agencia Estatal de Investigación | Ref. PID2020-113245RB-I00Fundação para a Ciência e a Tecnologia | Ref. UIDB/50017/2020Fundação para a Ciência e a Tecnologia | Ref. UIDP/50017/2020Xunta de Galicia | Ref. ED431C 2021/4

    Different approaches to analyze the impact of future climate change on the exploitation of wave energy

    Get PDF
    The increment of the share of renewable energies in the global mix implies that all renewable energies must be exploited. In this sense, it is necessary to make significant research and investment effort in the particular case of wave energy to reach the degree of maturity of other marine energies in the near future. Apart from the inherent factors that hinder the development of wave energy, such as the non-existence of a market-leading type of capturing device, uncertainties about the available future resource also hamper its growth. In this article, a review of the procedures followed in the literature to deal with the future wave energy resources and their subsequent exploitation is described. These procedures include the evaluation of the best future atmospheric models to drive wave models, the different downscaling techniques to evaluate the resource in large regions with high spatial resolution, and the analysis of the variability of the future energy resource and its future exploitability in a certain region taking into account different types of devices. Additionally, the current state of the art of previous studies dealing with future wave energy resources for different locations worldwide is described. Despite the difficulties involved in studying future wave energy resources, the high technological readiness level of the offshore wind industry, the creation of power generation farms with combined technologies, and the growth of marine aquaculture in the coming years could generate synergies that provide the definitive impulse to achieve the necessary technological development.Agencia Estatal de Investigación | Ref. PID2020‐113245RB‐I00Agencia Estatal de Investigación | Ref. TED2021-129479A-I00Xunta de Galicia | Ref. ED431C 2021/44Agencia Estatal de Investigación | Ref. IJC2020-043745-IAgencia Estatal de Investigación | Ref. PRE2021-097580European Cooperation in Science and TechnologyUniversidade de Vigo/CISU

    Use of archival versus newly collected tumor samples for assessing PD-L1 expression and overall survival : an updated analysis of KEYNOTE-010 trial

    No full text
    Background: In KEYNOTE-010, pembrolizumab versus docetaxel improved overall survival (OS) in patients with programmed death-1 protein (PD)-L1-positive advanced non-small-cell lung cancer (NSCLC). A prespecified exploratory analysis compared outcomes in patients based on PD-L1 expression in archival versus newly collected tumor samples using recently updated survival data. Patients and methods: PD-L1 was assessed centrally by immunohistochemistry (22C3 antibody) in archival or newly collected tumor samples. Patients received pembrolizumab 2 or 10 mg/kg Q3W or docetaxel 75 mg/m2 Q3W for 24 months or until progression/intolerable toxicity/other reason. Response was assessed by RECIST v1.1 every 9 weeks, survival every 2 months. Primary end points were OS and progression-free survival (PFS) in tumor proportion score (TPS) 50% and 1%; pembrolizumab doses were pooled in this analysis. Results: At date cut-off of 24 March 2017, median follow-up was 31 months (range 23-41) representing 18 additional months of follow-up from the primary analysis. Pembrolizumab versus docetaxel continued to improve OS in patients with previously treated, PD-L1-expressing advanced NSCLC; hazard ratio (HR) was 0.66 [95% confidence interval (CI): 0.57, 0.77]. Of 1033 patients analyzed, 455(44%) were enrolled based on archival samples and 578 (56%) on newly collected tumor samples. Approximately 40% of archival samples and 45% of newly collected tumor samples were PD-L1 TPS 50%. For TPS 50%, the OS HRs were 0.64 (95% CI: 0.45, 0.91) and 0.40 (95% CI: 0.28, 0.56) for archival and newly collected samples, respectively. In patients with TPS 1%, OS HRs were 0.74 (95% CI: 0.59, 0.93) and 0.59 (95% CI: 0.48, 0.73) for archival and newly collected samples, respectively. In TPS 50%, PFS HRs were similar across archival [0.63 (95% CI: 0.45, 0.89)] and newly collected samples [0.53 (95% CI: 0.38, 0.72)]. In patients with TPS 1%, PFS HRs were similar across archival [0.82 (95% CI: 0.66, 1.02)] and newly collected samples [0.83 (95% CI: 0.68, 1.02)]. Conclusion: Pembrolizumab continued to improve OS over docetaxel in intention to treat population and in subsets of patients with newly collected and archival samples

    The Large Aperture GRB Observatory

    Full text link
    The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at high altitude offer a unique possibility of detecting low gamma fluxes in the 10 GeV - 1 TeV range. The status of the Observatory and data collected from 2007 to date will be presented.Comment: 4 pages, proceeding of 31st ICRC 200
    corecore