278 research outputs found

    Flue gas adsorption by single-wall carbon nanotubes: A Monte Carlo study

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    Adsorption of flue gases by single-wall carbon nanotubes (SWCNT) has been studied by means of Monte Carlo simulations. The flue gas is modeled as a ternary mixture of N2, CO2, and O2, emulating realistic compositions of the emissions from power plants. The adsorbed flue gas is in equilibrium with a bulk gas characterized by temperature T , pressure p, and mixture composition. We have consid- ered different SWCNTs with different chiralities and diameters in a range between 7 and 20 Å. Our results show that the CO2 adsorption properties depend mainly on the bulk flue gas thermodynamic conditions and the SWCNT diameter. Narrow SWCNTs with diameter around 7 Å show high CO2 adsorption capacity and selectivity, but they decrease abruptly as the SWCNT diameter is increased. For wide SWCNT, CO2 adsorption capacity and selectivity, much smaller in value than for the narrow case, decrease mildly with the SWCNT diameter. In the intermediate range of SWCNT diameters, the CO2 adsorption properties may show a peculiar behavior, which depend strongly on the bulk flue gas conditions. Thus, for high bulk CO2 concentrations and low temperatures, the CO2 adsorption capacity remains high in a wide range of SWCNT diameters, although the corresponding selectivity is moderate. We correlate these findings with the microscopic structure of the adsorbed gas inside the SWCNTs.Ministerio de Economía y Competitividad MAT2013-42934-R y FIS2012-3245

    Histopathological evaluation of the subtotal laryngectomy specimen

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    AbstractBackgroundThe goal of conservative surgical treatment of laryngeal cancer is to obtain oncological control with preservation of laryngeal function. The concept of laryngeal function preservation should be understood as the preservation of the patient's ability to breathe normally with neither tracheostomy nor aspiration, and maintaining intelligible speech. This can be achieved by a balance between two fundamental aspects, proper patient selection (based on tumour extension and preoperative laryngeal function), and an adequate histopathological analysis of the surgical specimen. Supracricoid subtotal laryngectomy is the voice conservative surgical technique that offers the best possibility of control in patients with locally advanced laryngeal cancer. The proper histopathological analysis allows staging and selecting patients for adjuvant therapy, avoiding unnecessary ones as well as designing monitoring and surveillance programs based on risk factors.ObjectiveTo highlight key points in the histopathological evaluation of the surgical specimen of a subtotal laryngectomy.ConclusionThe proper communication between the surgeon and pathologist, offering complete information on preoperative clinical evaluation and the knowledge of the key points in the evaluation of the surgical specimen (sites of tumour leakage and surgical resection margins) are fundamental parameters to achieve a proper histopathological evaluation of the surgical specimen

    MODELOS DE DISPERSIÓN DE CONTAMINANTES ATMOSFÉRICOS: REVISIÓN SISTEMÁTICA

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    La presente revisión sistemática está sustentada en la declaración PRISMA. Se consideró estudios de los últimos 10 años, en los que se enfoca la utilidad de los modelos matemáticos para estudiar y predecir el comportamiento de la dispersión de los contaminantes atmosféricos. Se utilizaron las siguientes bases de datos; ScienceDirect, Dialnet, SciElo, ScienceResearch, PubMed y Redalyc, obteniendo un total de 4544 registros, descartándose 61 de estos por duplicidad, considerando finalmente 4483 registros, se excluyeron 3429, posteriormente, de los 1054 artículos elegidos, se excluyeron 991 por no estar relacionados con modelos de dispersión. Finalmente, se incluyeron 63 artículos originales para su análisis y elaboración de la revisión sistemática. La selección del modelo depende del tiempo, escenario, fuente de emisión y estabilidad atmosférica.  La importancia que tiene el control de la contaminación nos lleva a la utilización de modelos que nos permitan pronosticar la concentración en la dispersión de contaminantes atmosféricos, estos pueden ser teóricos o semi teóricos, y en la medida, que en el modelo se incluyan los parámetros adecuados de tal manera que se logre aproximar a la realidad, los resultados, mostrados, serán muy confiables, pero ello conlleva a un modelo muy complejo. Los modelos más utilizados son: gaussianos y los modelos lagrangianos

    Psychometric Properties of the Affective Dimension of the Generic Macro-Competence Assessment Scale: Analysis Using Rasch Model

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    The study of the affective dimension of transversal competences is essential for the development of responsible behaviors and maintaining attitudes committed to sustainable development. The importance attributed to each of these factors can predict behavior implementation and awareness of values for sustainable development that reflect the acquisition and internalization of sustainabilityrelated generic competences. This study aimed to determine the psychometric properties of the affective dimension of the Generic Macro-Competence Assessment (AGMA) scale by applying Rasch measurement model to a sample of Spanish university students, comprising 387 Spanish university students (74.9% women; mean age = 21.24; WD = 3.54; range: 17–34). Results demonstrated a lack of adjustment to the Rasch model due to item 1, and all items showed disordered response category thresholds. The remaining nine-item scale achieved all requirements of the model (χ2 = 61.46; p = 0.052), including unidimensionality. Thus, the scale’s psychometric properties indicate an easyto-apply instrument for screening these factors for coping strategies in undergraduate and graduate Spanish students. The results can help in justifying the design of interdisciplinary intervention programs, in which affective factors are essential for sustainable development education.Educational Innovation Project titled “New proposals for the integration of competences through transversal training evaluation and ICT” (PIE19-159, Call 2019–2021, UMA

    Stomatal control and hydraulic conductivity in 'Manzanilla' olive trees under different water regimes

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    Ministry of Education and Science (España) No.AGL2006-04666/AGREU, research project ref. STREP 02312

    Influence of the soil water content and distribution on both the hydraulic and transpiration performance of 'Manzanilla' olive trees

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    8 páginas, 4 figuras, 20 referencias.-- VI International Symposium on Irrigation of Horticultural Crops, celebrado del 2-6 de noviembre de 2006 en Viña del Mar, Chile.-- [email protected] work was made with mature 'Manzanilla' olive trees in an orchard of a semi-arid area in southern Spain. Three water treatments were considered: Rainfed, in which the trees had rainfall as the only source of water supply; FAO, in which the trees were under localized irrigation to replace the crop water demand, with some roots left in drying soil; Pond, in which the whole rootzones of the trees were maintained under non-limiting soil water conditions for the whole dry season. Our aim was to obtain information on the mechanisms behind the reduction of transpiration (Ep) in the FAO trees, as compared to the Pond trees. Our results show a near-isohydric behaviour of the FAO trees, i.e. those trees under localized irrigation in which some roots are left in drying showed lower stomatal conductance than the Pond trees in which all roots were in wetted soil. This helped the FAO trees to maintain similar leaf water potentials than the Pond trees. In addition, the FAO trees maintained a constant difference between the water potential of the canopy and that in the soil. This has been described as an isohydrodynamic behaviour, and it is thought to be an improvement over a typically anisohydric behaviour. These mechanisms were behind the similar values of tree hydraulic conductance (K p) found in the FAO and Pond treatments. The Rainfed trees showed lower Kp values because of the low Ep values of those trees, due to the low soil water availability in that treatment. Our results show, however, that the Rainfed trees were able to maintain similar values of Kp all throughout the dry season, which shows that the hydraulic efficiency of the xylem of those trees was little affected by embolism, despite of the high demanding conditions in the area.This work has been funded by the Spanish Ministry of Education and Science, research project No.AGL2006-04666/AGR, and by the EU, research project ref. STREP 023120.Peer Reviewe

    Exploring the Antioxidant, Neuroprotective, and Anti-Inflammatory Potential of Olive Leaf Extracts from Spain, Portugal, Greece, and Italy

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    The leaves of the olive tree (Olea europaea L.) are one of the major solid wastes from the olive industry. Globally, the European Union is the largest producer of olive by-products, with Spain, Italy, Greece, and Portugal accounting for almost the entire production. Many questions remain to be solved concerning olive leaves (OL), including those related to possible differences in composition and/or biological activities depending on their geographical origin. In the present work, OL from Spain, Italy, Greece, and Portugal have been characterized according to their phytochemical profile, antioxidant capacity, neuroprotective activity, and anti-inflammatory effects. The Spanish and Italian OL samples presented the highest antioxidant and neuroprotective activities, while the Greek OL showed the lowest. These results were strongly associated with the content of oleoside methyl ester and p-hydroxybenzoic acid for the Spanish and Italian samples, respectively, whereas the content of decarboxymethyl elenolic acid dialdehyde form (hydrated) was negatively associated with the mentioned biological activities of the Greek samples. No country-related effect was observed in the anti-inflammatory activity of OL. Comprehensively, this work could provide a useful tool for manufacturers and R&D departments in making environmentally friendly decisions on how OL can be used to generate nutraceutical products based on the composition and origin of this by-productPRIMA EU programSUSTAINOLIVE grant n 1811PID2019-106778RB-I00, funded by MCIN/AEI/10.13039/501100011033 FEDER “Una Manera de Hacer Europ

    Influence of the soil water content and distribution on both the hydraulic and transpiration performance of 'Manzanilla' olive trees

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    VI International Symposium on Irrigation of Horticultural Crops, celebrado del 2-6 de noviembre de 2006 en Viña del Mar, Chile ISBN-978-90-66057-13-5This work was made with mature 'Manzanilla' olive trees in an orchard of a semi-arid area in southern Spain. Three water treatments were considered: Rainfed, in which the trees had rainfall as the only source of water supply; FAO, in which the trees were under localized irrigation to replace the crop water demand, with some roots left in drying soil; Pond, in which the whole rootzones of the trees were maintained under non-limiting soil water conditions for the whole dry season. Our aim was to obtain information on the mechanisms behind the reduction of transpiration (Ep) in the FAO trees, as compared to the Pond trees. Our results show a near-isohydric behaviour of the FAO trees, i.e. those trees under localized irrigation in which some roots are left in drying showed lower stomatal conductance than the Pond trees in which all roots were in wetted soil. This helped the FAO trees to maintain similar leaf water potentials than the Pond trees. In addition, the FAO trees maintained a constant difference between the water potential of the canopy and that in the soil. This has been described as an isohydrodynamic behaviour, and it is thought to be an improvement over a typically anisohydric behaviour. These mechanisms were behind the similar values of tree hydraulic conductance (K p) found in the FAO and Pond treatments. The Rainfed trees showed lower Kp values because of the low Ep values of those trees, due to the low soil water availability in that treatment. Our results show, however, that the Rainfed trees were able to maintain similar values of Kp all throughout the dry season, which shows that the hydraulic efficiency of the xylem of those trees was little affected by embolism, despite of the high demanding conditions in the area.Ministry of Education and Science (Spain) AGL2006-04666/AGRUnión Europea STREP 327 02312
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