114 research outputs found

    Techno-economic assessment for the optimization of parabolic trough solar thermal power plants with thermal storage

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    Dentro de la tecnología de receptor central, el campo de colectores cilindro parabólicos es el sistema de generación de electricidad por fuente renovable de mayor implantación a nivel mundial. Además, los avances en diseño y fabricación permiten definir parámetros específicos adaptados a la localización de la planta, requerimientos técnicos y tipo de mercado eléctrico. Avances que proporcionan una importante reducción de los costes de implantación. Partiendo de la elaboración del marco teórico y del establecimiento de un modelo matemático para una central real en operación de 50MWe con almacenamiento térmico mediante doble tanque de sales fundidas, el método de optimización presentado establece propuestas que permiten conocer las proporciones óptimas de dimensionado del campo solar, tipo y sistema de almacenamiento térmico y modo de operación de la planta de generación. Esta Tesis Doctoral tiene como finalidad establecer estrategias encaminadas a maximizar la viabilidad y rendimiento tecno-económico de este tipo de centrales de generación eléctrica. Por tanto, el dimensionado y operación óptimos de planta se presenta como objetivo principal de este trabajo, considerando como variables de decisión, el lugar de implantación, dimensionado del campo solar, almacenamiento de energía térmica y tipo de mercado eléctrico. Los resultados obtenidos se agrupan en seis bloques, dimensionamiento óptimo del campo solar, optimización del sistema de almacenamiento térmico, reducción de los costes de implantación, optimizar la producción de electricidad, y aumentar los beneficios de la venta de energía eléctrica. Se ha desarrollado un sistema de almacenamiento térmico innovador a través de la generación de un bucle de fluido térmico dentro del campo solar denominado “HTF Buffering”. Los valores del coste nivelado de electricidad y del factor de capacidad obtenidos del entorno de simulación, posicionan a “HTF Buffering” como una alternativa tecno-económica viable a los sistemas tradicionales de almacenamiento de energía térmica para este tipo de centrales de generación. Así mismo, La optimización de operación de una planta de 50 MWe con almacenamiento térmico mediante doble tanque de sales fundidas, dentro de mercado eléctrico no regulado, ofrece un aumento respecto a los sistemas de generación estándar, tanto de producción como de beneficio de venta de electricidad. Por su parte, el estudio de una central de 100 MWe con almacenamiento por doble tanque de sales fundidas, considerando mercados regulado y no regulado, ofrece el tamaño de planta y operación de mercado óptimos acorde a cada una de los escenarios de radiación solar estudiados. Así, los resultados presentados en este trabajo aportan respuestas a factores clave para los estudios de viabilidad, procesos de implantación y modo operación de plantas termosolares con tecnología de colectores cilindro parabólicos, son aplicables independientemente del tamaño de la planta de generación, y posibilitan la optimización de costes en los procesos de implantación y operación.Within solar reception technology, parabolic trough is the most implemented renewable energy system for electric energy generation worldwide. Moreover, progress in design and manufacturing let defining specific parameters adapted to the plant location, technical requirements and the electricity market type. Advances that provide an important investment costs reduction. Thus, starting from the state of the art and the implementation of a mathematical model for a real parabolic trough solar thermal power plant of 50MWe with thermal storage, the optimization method presented attempts to establish strategies aimed at maximizing the plant investment viability and techno-economic performance. This Doctoral Thesis focus on the establishment of strategies aimed at maximizing the feasibility and technoeconomic performance of this type of power plants. Thus, optimal plant sizing and operation is presented as the main objective of this work, considering as decision variables, the implementation area, sizing of the solar field, storage of thermal energy and type of electric market. The results obtained are grouped into six blocks, optimal sizing of the solar field, optimization of the thermal storage system, reduction of implementation costs, greater electricity production, and increase the profits of the sale of Electricity.An unpublished thermal storage system has been developed throughout the generation of a thermal fluid loop within the solar field called "HTF Buffering". The values of the levelized cost of electricity and the capacity factor, obtained from the simulation environment, position "HTF Buffering" as a viable techno-economic alternative to traditional thermal energy storage systems for this type of power plants. Likewise, the optimization of the operation of a 50 MWe plant with thermal storage by double tank of molten salt, within unregulated electrical market, offers an increase over standard generation systems in both production and profit from electricity sales. Besides, the study of a 100 MWe plant with storage by double tank of molten salts, considering regulated and unregulated markets, offers the optimization of the plant size as well as the optimal market operation according to each of the solar radiation scenarios studied. The conclusions herein presented provide answers to key factors for feasibility studies, implementation processes, plant managing and operation of parabolic trough solar thermal power plants. They are applicable regardless the size of the power plant as well as enable cost optimization in the implementation and operation processes

    Techno-Economic Assessment of Heat Transfer Fluid Buffering for Thermal Energy Storage in the Solar Field of Parabolic Trough Solar Thermal Power Plants

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    Currently, operating parabolic trough (PT) solar thermal power plants, either solar-only or with thermal storage block, use the solar field as a heat transfer fluid (HTF) thermal storage system to provide extra thermal capacity when it is needed. This is done by circulating heat transfer fluid into the solar field piping in order to create a heat fluid buffer. In the same way, by oversizing the solar field, it can work as an alternative thermal energy storage (TES) system to the traditionally applied methods. This paper presents a solar field TES model for a standard solar field from a 50-MWe solar power plant. An oversized solar model is analyzed to increase the capacity storage system (HTF buffering). A mathematical model has been developed and different simulations have been carried out over a cycle of one year with six different solar multiples considered to represent the different oversized solar field configurations. Annual electricity generation and levelized cost of energy (LCOE) are calculated to find the solar multiple (SM) which makes the highest solar field thermal storage capacity possible within the minimum LCOE

    Optimization of 100 MWe Parabolic-Trough Solar-Thermal Power Plants Under Regulated and Deregulated Electricity Market Conditions

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    Parabolic-trough solar-thermal power-plant investments are subordinate to radiation availability, thermal-energy storage capacity, and dynamic behavior. Their integration into electricity markets is made by minimizing grid-connection costs, thus improving energy-availability and economic-efficiency levels. In this context, this work analyzes the sizing-investment adequacy of a 100 MWe parabolic-trough solar-thermal power plant regarding solar resources and thermal energy into power-block availability for both regulated and deregulated electricity markets. For this proposal, the design of a mathematical model for the optimal operation of parabolic-trough power plants with thermal storage by two tanks of molten salt is described. Model calibration is made by using a currently operated plant. Solar-resource availability is studied in three different radiation scenarios. The levelized cost of electricity and production profit relating to the investment cost are used to analyze plant sustainability. Thus, the levelized cost of electricity shows the best plant configuration for each radiation scenario within a regulated market. For deregulated markets, the optimal plant configuration tends to enhance the solar multiple and thermal-storage capacity thanks to an increment on selling profit. The gross average annual benefit for electricity generation of deregulated against regulated markets exceeds 21% in all radiation areas under study

    Evolución paleoambiental de la mitad sur de la Península Ibérica. Aplicación a la evaluación del comportamiento de los repositorios de residuos radiactivos

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    Esta publicación refleja los resultados obtenidos de la realización de los proyectos "EQUIP: Evidency from Quaternary Infills Palaeohydrogeology" (F 14W/ CT96/0031), financiado por la UE, "Evolución Paleoclimática de [a Mitad Sur de [a Península Ibérica" financiado por ENRESA y "Paleoclima" financiado por el Consejo de Seguridad Nuclear y ENRESA. La cuenca de Guadix-Baza, sector oriental, es una de las escasas zonas europeas donde se ha conservado un registro razonablemente completo del Pleistoceno. La cuenca de Guadix Baza, en régimen continental desde el Plioceno, funcionó bajo un régimen centrípeto, con abanicos aluviales en los bordes y una zona compleja lacustre en mosaico en su centro. Se ha podido establecer la existencia de una amplia variedad de facies aluviales y fluviales y sus interrelaciones. La sedimentación en el margen lacustre estaba constituida por arenas bioclásticas y lutitas con fósiles, mientras que en zonas más centrales predominaron lutitas yesíferas, lutitas con yeso intrasedimentario, arenas yesíferas yesos y, ocasionalmente, carbonatos que durante un período concreto depositaron los materiales que configuran el "Nivel Calcáreo de Orce", calizas y dolomías con cantidades variables de yeso y terrígenos cerca de los bordes. El trabajo de campo permitió el establecimiento de una serie estratigráfica tipo compuesta, que refleja los principales acontecimiento paleoambientales que tuvieron lugar durante el Pleistoceno. Con el fin de evitar la yesificación de la calcita y aragonito, propia del ambiente lacustre, la serie tipo de ha establecido en el registro del margen lacustre. Con ayuda del análisis paleomagnético y el análisis de la racemización de aminoácidos en conchas de moluscos y ostrácodos se ha establecido la cronología numérica de la sección estratigráfica tipo que cubre desde el límite Plioceno-Pleistoceno hasta unos 250 ka BP, cuando la erosión de la cabecera del río Fardes alcanza la cuenca abriéndola hacia el valle del Guadalquivir y cesando [a sedimentación lacustre. También se ha datado un depósito de terraza fluvial. Se han obtenido datos paleoambientales "instantáneos" mediante el estudio palinológico, el análisis paleobotánico de material silicificado (madera opalizada) o carbonizado (análisis paleoantracológico), el análisis geoquímico orgánico de algunos niveles especialmente favorables. La geoquímica orgánica de biomarcadores de algunos niveles concretos proporcionó datos sobre su origen (plantas terrestres o acuáticas) y confirmó que un conspicuo nivel carbonoso tuvo su origen en un incendio forestal. El análisis paleobiológico basado en la distribución de especies de ostrácodos, gasterópodos y pelecípodos ha permitido una primera aproximación paleoambiental, pese al evidente sesgo introducido por la presencia de fuentes salinas y materiales yesíferos en el área fuente de los abanicos aluviales del límite oriental de la cuenca. Esta interpretación se ha depurado mediante el estudio geoquímico inorgánico, isótopos estables y elementos traza de las conchas calcíticas de ostrácodos. Ello ha permitido el establecimiento de una alternancia de períodos "fríos y húmedos" y "cálidos y áridos" que permiten reconocer de las clases climáticas "mediterráneo seco" y "mediterráneo húmedo" sensu Horowitz (1989), que tienen sus correlatos en el registro paleoclimático de los grandes lagos del rift del Mar Muerto, el Mar Caspio y lagos pluviales de Norte América. La correlación de los datos isotópicos con las paleosalinidades deducidas del estudio de las inclusiones fluidas en yeso intrasedimentario ha permitido corroborar estas interpretaciones. Esto plantea un nuevo enfoque en el análisis del comportamiento de los repositorios de residuos radiactivos de alta

    Equity, diversity, and inclusion at the Global Alliance for Genomics and Health

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    A lack of diversity in genomics for health continues to hinder equitable leadership and access to precision medicine approaches for underrepresented populations. To avoid perpetuating biases within the genomics workforce and genomic data collection practices, equity, diversity, and inclusion (EDI) must be addressed. This paper documents the journey taken by the Global Alliance for Genomics and Health (a genomics-based standard-setting and policy-framing organization) to create a more equitable, diverse, and inclusive environment for its standards and members. Initial steps include the creation of two groups: the Equity, Diversity, and Inclusion Advisory Group and the Regulatory and Ethics Diversity Group. Following a framework that we call "Reflected in our Teams, Reflected in our Standards," both groups address EDI at different stages in their policy development process. [Abstract copyright: © 2023 The Author(s).

    High Smac/DIABLO expression is associated with early local recurrence of cervical cancer

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    <p>Abstract</p> <p>Background</p> <p>In a recent pilot report, we showed that Smac/DIABLO mRNA is expressed <it>de novo </it>in a subset of cervical cancer patients. We have now expanded this study and analyzed Smac/DIABLO expression in the primary lesions in 109 cervical cancer patients.</p> <p>Methods</p> <p>We used immunohistochemistry of formalin-fixed, paraffin-embedded tissue sections to analyze Smac/DIABLO expression in the 109 primary lesions. Seventy-eight samples corresponded to epidermoid cervical cancer and 31 to cervical adenocarcinoma. The median follow up was 46.86 months (range 10–186).</p> <p>Results</p> <p>Smac/DIABLO was expressed in more adenocarcinoma samples than squamous tumours (71% vs 50%; p = 0.037). Among the pathological variables, a positive correlation was found between Smac/DIABLO immunoreactivity and microvascular density, a marker for angiogenesis (p = 0.04). Most importantly, Smac/DIABLO immunoreactivity was associated with a higher rate of local recurrence in squamous cell carcinoma (p = 0.002, log rank test). No association was found between Smac/DIABLO and survival rates.</p> <p>Conclusion</p> <p>Smac/DIABLO expression is a potential marker for local recurrence in cervical squamous cell carcinoma patients.</p

    Inter-Rater Variability in the Evaluation of Lung Ultrasound in Videos Acquired from COVID-19 Patients

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    12 páginas, 7 figuras, 1 tablaLung ultrasound (LUS) allows for the detection of a series of manifestations of COVID-19, such as B-lines and consolidations. The objective of this work was to study the inter-rater reliability (IRR) when detecting signs associated with COVID-19 in the LUS, as well as the performance of the test in a longitudinal or transverse orientation. Thirty-three physicians with advanced experience in LUS independently evaluated ultrasound videos previously acquired using the ULTRACOV system on 20 patients with confirmed COVID-19. For each patient, 24 videos of 3 s were acquired (using 12 positions with the probe in longitudinal and transverse orientations). The physicians had no information about the patients or other previous evaluations. The score assigned to each acquisition followed the convention applied in previous studies. A substantial IRR was found in the cases of normal LUS (κ = 0.74), with only a fair IRR for the presence of individual B-lines (κ = 0.36) and for confluent B-lines occupying 50% (κ = 0.50). No statistically significant differences between the longitudinal and transverse scans were found. The IRR for LUS of COVID-19 patients may benefit from more standardized clinical protocols.This research was partially funded by CDTI (Spanish acronym: Centre for Industrial Tech- nological Development), funding number COI-20201153. Partially supported by the Google Cloud Research Credits program with the funding number GCP19980904, by the project RTI2018-099118- A-I00 founded by MCIU/AEI/FEDER UE and by the European Commission–NextGenerationEU, through CSIC’s Global Health Platform (PTI Salud Global)

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
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