46 research outputs found

    Produced water treatment by advanced oxidation processes

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    Abstract Different Advanced Oxidation Processes (AOPs) such as photocatalysis, Fenton-based processes and ozonation were studied to include one of these technologies within an integrated solution for produced water (PW) polishing. Synthetic PW was prepared adding toluene, xylene, naphthalene, phenol, acetic and malonic acids to a seawater matrix. Despite that in all AOPs studied in this work BTEX and naphthalene were removed, the efficiency (in terms of TOC removal) of each treatment varied largely. Among these techniques, photocatalysis was found to be the less effective for the treatment of PW, as TOC removals lower than 20% were obtained for the best scenario after 4 h treatment. In the contrary, best results were obtained by ozonation combined with H2O2, where all the organic components were removed, including a high percentage of acetic acid, which was not abated by the rest of the AOPs studied. The optimum conditions for ozonation were 4 g h−1 O3 and 1500 mg L−1 H2O2 at pH 10, where after 2 h a 74% of TOC removal was achieved and the acetic acid elimination was 78%. This condition enabled that ozonation process accounted for the lowest electric energy consumption per order of target compound destruction regarding total organic carbon (TOC)

    Synthesis of pillared clays from metallic salts as pigments for thermosolar absorptive coatings

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    [EN] A general procedure for developing stable solar absorptive coatings at both high temperature and a high solar radiation concentration is presented. In order to generally improve thermal efficiency, a coating with high solar absorptance is applied all over the surface of receiver tubes that is subjected to extreme working conditions. Consequently, a durable coating with high absorptivity for sunlight is needed. An alternative paint formulation research and development line to Pyromark-2500, the paint currently used in many commercial solar thermal power plants (CSP) is proposed. Pigment synthesis is developed by intercalating metallic salts into laminar or tubular clay structures. Metallic pxides, which provide paint with its color properties, are obtained by a calcination process. Addition of silane or surfactants during the pigment synthesis is also optimized. Once dried and ground to a precise size, pigments are mixed with a commercial binder and applied to a metallic substrate to study their properties. Thermal stability to high temperature is studied with different tests. The results showed that laminar structure was preferred to intercalate larger amounts of metallic salt into the clay structure, and no significant differences were found when using silane or surfactant modifiers. Although the highest absorptivity value was 85% after 24 h at 600 degrees C, samples presented very good adherence to the metallic substrate. Addition of a small quantity of commercial black pigment to the paint composition could improve the absorptivity and maintain the excellent adhesion shown. Furthermore, montmorillonite clay, modified with a surfactant before adding metallic salt, and without silane, resulted in a black pigment in a powder form. This pillared clay could be used in future paint formulations. (C) 2017 Elsevier Ltd. All rights reserved.The research that has led to these results was funded by Abengoa Solar New Technologies S.A. by a private contract with the Colour and Vision Group of the University of Alicante.Micó Vicent, B.; López-Herraiz, M.; Bello, A.; Martínez, N.; Martinez-Verdu, FM. (2017). Synthesis of pillared clays from metallic salts as pigments for thermosolar absorptive coatings. Solar Energy. 155:314-322. doi:10.1016/j.solener.2017.06.034S31432215

    Probabilistic solution of the homogeneous Riccati differential equation: A case-study by using linearization and transformation techniques

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    [EN] This paper deals with the determination of the first probability density function of the solution stochastic process to the homogeneous Riccati differential equation taking advantage of both linearization and Random Variable Transformation techniques. The study is split in all possible casuistries regarding the deterministic/random character of the involved input parameters. An illustrative example is provided for each one of the considered cases.This work has been partially supported by the Ministerio de Economia y Competitividad grants MTM2013-41765-P and TRA2012-36932.Casabán, MC.; Cortés, J.; Navarro-Quiles, A.; Romero, J.; Roselló, M.; Villanueva Micó, RJ. (2016). Probabilistic solution of the homogeneous Riccati differential equation: A case-study by using linearization and transformation techniques. Journal of Computational and Applied Mathematics. 291:20-35. https://doi.org/10.1016/j.cam.2014.11.028S203529

    Potenciales evocados cerebrales en el contexto de la investigación psicológica: una actualización

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    -Event-related brain potentials (ERPS) are presented in the context of the psychological research. Firstly, aspects such as how un ERP is obtained, their characteristic features, the way in which they are classified, or their main advantages with respect to another type of measures usually used in Psychology, are presented. Then, two cognitive processes that have been extensively investigated with this technique are briejly reviewed,concretely, attention and language, and the recent research in the study of emotional processes is also commented. The main ERPs that have been used to study these psychological processes are discussed.En este articulo se presenta la técnica de registro de 10s potenciales evocados (PESe)n el contexto de la investigación psicológica. En primer lugar, se abordan aspectos tales como el proceso de obtención de un potencial evocado, sus caracteristicas definitorias, la forma en que se clasifican, sus principales ventajas respecto a otro tipo de medidas  usualmente utilizadas por la psicologia, etc. A continuación se repasan brevemente dos de 10s procesos cognitivos que han generado más investigación con esta técnica, concretamente la atención y el lenguaje, usí como 10s recientes avances que se han desarrollado en el campo de 10s procesos emocionales. Se comentan después 10s principales potenciales evocados que se utilizan para abordar este tip0 de procesos psicológicos

    Optimum Multilayer-Graphene-Montmorillonite Composites From Sugar for Thermosolar Coatings Formulations

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    Solar thermal coatings are designed to achieve the highest incident solar flux into the receiver of a tower solar plant. These materials are subjected to extreme working conditions of temperature and solar concentrated radiation. Much effort is being made to develop a durable and high absorptive coating that can provide an excellent solar to heat conversion efficiency. Complex deposition techniques (PVD, CVD, electrodeposition, etc.) are developed and tested to achieve solar selectivity. High solar absorptance paints are an alternative technique, that is, easy to apply and implement in the field. In paint, pigments are the compound that provides high absorptance values, whose stability impacts the durability of optical properties. The search for new selective solar pigments for solar receivers is a promising route to improve the efficiency of this technology. In this work, novel nanocomposites were synthesized from low-cost organic materials such as table sugar. Promising results were obtained when intercalated and calcined in the laminar structure of montmorillonite, a type of smectite clay. The pigments were tested in a paint format on metallic coupons at different temperatures to obtain absorptivities above 96% of absorptance after 24 h at 700  °C. Further experiments are still needed to obtain optimum conditions to maximize the coating's absorptivity and durability at high temperature.Abengoa Solar S.A

    Molecular characterization of imported and autochthonous dengue in northeastern spain

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    Dengue is the most significant arbovirus worldwide and a public health threat to nonendemic areas in which Aedes vectors are present. Autochthonous dengue transmission has been reported in several European countries in the last decade. Infected travelers from endemic regions arriving to areas colonized by Aedes albopictus in Europe need to be monitored in surveillance and control programs. We aimed to perform molecular characterization of RT-PCR-positive dengue cases detected in Catalonia, northeastern Spain, from 2013 to 2018. The basic demographic information and the geographical regions of importation were also analyzed. One-hundred four dengue cases were studied (103 imported infections and the first autochthonous case in our region). The dengue virus strains detected were serotyped and genotyped using molecular methods, and phylogenetic analyses were conducted. All four dengue serotypes were detected in travelers, including up to 10 different genotypes, reflecting the global circulation of dengue in endemic areas. The primary travel-related case of the 2018 autochthonous transmission was not identified, but the molecular analysis revealed dengue serotype 1, genotype I of Asian origin. Our results highlight the diversity of imported dengue virus strains and the role of molecular epidemiology in supporting arbovirus surveillance programs

    Association Patterns in Saproxylic Insect Networks in Three Iberian Mediterranean Woodlands and Their Resistance to Microhabitat Loss

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    The assessment of the relationship between species diversity, species interactions and environmental characteristics is indispensable for understanding network architecture and ecological distribution in complex networks. Saproxylic insect communities inhabiting tree hollow microhabitats within Mediterranean woodlands are highly dependent on woodland configuration and on microhabitat supply they harbor, so can be studied under the network analysis perspective. We assessed the differences in interacting patterns according to woodland site, and analysed the importance of functional species in modelling network architecture. We then evaluated their implications for saproxylic assemblages’ persistence, through simulations of three possible scenarios of loss of tree hollow microhabitat. Tree hollow-saproxylic insect networks per woodland site presented a significant nested pattern. Those woodlands with higher complexity of tree individuals and tree hollow microhabitats also housed higher species/interactions diversity and complexity of saproxylic networks, and exhibited a higher degree of nestedness, suggesting that a higher woodland complexity positively influences saproxylic diversity and interaction complexity, thus determining higher degree of nestedness. Moreover, the number of insects acting as key interconnectors (nodes falling into the core region, using core/periphery tests) was similar among woodland sites, but the species identity varied on each. Such differences in insect core composition among woodland sites suggest the functional role they depict at woodland scale. Tree hollows acting as core corresponded with large tree hollows near the ground and simultaneously housing various breeding microsites, whereas core insects were species mediating relevant ecological interactions within saproxylic communities, e.g. predation, competitive or facilitation interactions. Differences in network patterns and tree hollow characteristics among woodland sites clearly defined different sensitivity to microhabitat loss, and higher saproxylic diversity and woodland complexity showed positive relation with robustness. These results highlight that woodland complexity goes hand in hand with biotic and ecological complexity of saproxylic networks, and together exhibited positive effects on network robustness.The research Projects I+D CGL2011-23658 y CGL2012-31669 of the Spanish Minister of Science provided economic support

    One-year longitudinal association between changes in dietary choline or betaine intake and cardiometabolic variables in the PREvención con DIeta MEDiterránea-Plus (PREDIMED-Plus) trial

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    Choline and betaine intakes have been related to cardiovascular health. We aimed to explore the relation between 1-y changes in dietary intake of choline or betaine and 1-y changes in cardiometabolic and renal function traits within the frame of the PREDIMED (PREvención con DIeta MEDiterránea)-Plus trial. We used baseline and 1-y follow-up data from 5613 participants (48.2% female and 51.8% male; mean ± SD age: 65.01 ± 4.91 y) to assess cardiometabolic traits, and 3367 participants to assess renal function, of the Spanish PREDIMED-Plus trial. Participants met ≥3 criteria of metabolic syndrome and had overweight or obesity [BMI (in kg/m 2) ≥27 and ≤40]. These criteria were similar to those of the PREDIMED parent study. Dietary intakes of choline and betaine were estimated from the FFQ. The greatest 1-y increase in dietary choline or betaine intake (quartile 4) was associated with improved serum glucose concentrations (−3.39 and −2.72 mg/dL for choline and betaine, respectively) and HbA1c levels (−0.10% for quartile 4 of either choline or betaine intake increase). Other significant changes associated with the greatest increase in choline or betaine intake were reduced body weight (−2.93 and −2.78 kg, respectively), BMI (−1.05 and −0.99, respectively), waist circumference (−3.37 and −3.26 cm, respectively), total cholesterol (−4.74 and −4.52 mg/dL, respectively), and LDL cholesterol (−4.30 and −4.16 mg/dL, respectively). Urine creatinine was reduced in quartile 4 of 1-y increase in choline or betaine intake (−5.42 and −5.74 mg/dL, respectively). Increases in dietary choline or betaine intakes were longitudinally related to improvements in cardiometabolic parameters. Markers of renal function were also slightly improved, and they require further investigation. This trial was registered at as ISRCTN89898870

    Morbid liver manifestations are intrinsically bound to metabolic syndrome and nutrient intake based on a machine-learning cluster analysis

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    Metabolic syndrome (MetS) is one of the most important medical problems around the world. Identification of patient ' s singular characteristic could help to reduce the clinical impact and facilitate individualized management. This study aimed to categorize MetS patients using phenotypical and clinical variables habitually collected during health check-ups of individuals considered to have high cardiovascular risk. The selected markers to categorize MetS participants included anthropometric variables as well as clinical data, biochemical parameters and prescribed pharmacological treatment. An exploratory factor analysis was carried out with a subsequent hierarchical cluster analysis using the z-scores from factor analysis. The first step identified three different factors. The first was determined by hypercholesterolemia and associated treatments, the second factor exhibited glycemic disorders and accompanying treatments and the third factor was characterized by hepatic enzymes. Subsequently four clusters of patients were identified, where cluster 1 was characterized by glucose disorders and treatments, cluster 2 presented mild MetS, cluster 3 presented exacerbated levels of hepatic enzymes and cluster 4 highlighted cholesterol and its associated treatments Interestingly, the liver status related cluster was characterized by higher protein consumption and cluster 4 with low polyunsaturated fatty acid intake. This research emphasized the potential clinical relevance of hepatic impairments in addition to MetS traditional characterization for precision and personalized management of MetS patients
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