616 research outputs found

    Helical Magnetic Fields from Sphaleron Decay and Baryogenesis

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    Many models of baryogenesis rely on anomalous particle physics processes to give baryon number violation. By numerically evolving the electroweak equations on a lattice, we show that baryogenesis in these models creates helical cosmic magnetic fields. After a transitory period, electroweak dynamics is found to conserve the Chern-Simons number and the total electromagnetic helicity. We argue that baryogenesis could lead to magnetic fields of nano-Gauss strength today on astrophysical length scales. In addition to being astrophysically relevant, such helical magnetic fields can provide an independent probe of baryogenesis and CP violation in particle physics.Comment: 4 pages, 1 figure. Added references, fixed typo

    Big Data Analytics for Smart Cities: The H2020 CLASS Project

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    Applying big-data technologies to field applications has resulted in several new needs. First, processing data across a compute continuum spanning from cloud to edge to devices, with varying capacity, architecture etc. Second, some computations need to be made predictable (real-time response), thus supporting both data-in-motion processing and larger-scale data-at-rest processing. Last, employing an event-driven programming model that supports mixing different APIs and models, such as Map/Reduce, CEP, sequential code, etc.The research leading to these results has received funding from the European Union’s Horizon 2020 Programme under the CLASS Project (www.class-project.eu), grant agreement No. 780622.Peer ReviewedPostprint (author's final draft

    Modeling light and temperature influence on ammonium removal by Scenedesmus sp. under outdoor conditions

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    [EN] The ammonium removal rate of the microalga Scenedesmus sp. was studied under outdoor conditions. Microalgae were grown in a 500 L flat-plate photobioreactor and fed with the effluent of a submerged anaerobic membrane bioreactor. Temperature ranged between 9.5 WC and 32.5 WC and maximum light intensity was 1,860 μmol·m2·s1. A maximum specific ammonium removal rate of 3.71 mg NH4 þ-N·g TSS1·h1 was measured (at 22.6 WC and with a light intensity of 1,734 μmol·m2·s1). A mathematical model considering the influence of ammonium concentration, light and temperature was validated. The model successfully reproduced the observed values of ammonium removal rate obtained and it is thus presented as a useful tool for plant operation.This research work has been supported by the Spanish Ministry of Education, Culture and Sports (CTM2011-28595-C02-01/02) jointly with the European Regional Development Fund (ERDF) and Generalitat Valenciana (ACOMP2013/203), which are gratefully acknowledged. This research was also supported by the Spanish Ministry of Education, Culture and Sport via a pre-doctoral FPU fellowship to the first author (AP2009-4903). The authors also gratefully acknowledge the support from the water management entities of the Generalitat Valenciana (EPSAR).Ruiz Martinez, A.; Serralta Sevilla, J.; Seco Torrecillas, A.; Ferrer, J. (2016). Modeling light and temperature influence on ammonium removal by Scenedesmus sp. under outdoor conditions. Water Science & Technology. 74(8):1964-1970. https://doi.org/10.2166/wst.2016.383S19641970748Ã…kerström, A. M., Mortensen, L. M., Rusten, B., & Gislerød, H. R. (2014). Biomass production and nutrient removal by Chlorella sp. as affected by sludge liquor concentration. Journal of Environmental Management, 144, 118-124. doi:10.1016/j.jenvman.2014.05.015Bernard, O., & Rémond, B. (2012). Validation of a simple model accounting for light and temperature effect on microalgal growth. Bioresource Technology, 123, 520-527. doi:10.1016/j.biortech.2012.07.022Brennan, L., & Owende, P. (2010). Biofuels from microalgae—A review of technologies for production, processing, and extractions of biofuels and co-products. Renewable and Sustainable Energy Reviews, 14(2), 557-577. doi:10.1016/j.rser.2009.10.009Broekhuizen, N., Park, J. B. K., McBride, G. B., & Craggs, R. J. (2012). Modification, calibration and verification of the IWA River Water Quality Model to simulate a pilot-scale high rate algal pond. Water Research, 46(9), 2911-2926. doi:10.1016/j.watres.2012.03.011Giménez, J. B., Robles, A., Carretero, L., Durán, F., Ruano, M. V., Gatti, M. N., … Seco, A. (2011). Experimental study of the anaerobic urban wastewater treatment in a submerged hollow-fibre membrane bioreactor at pilot scale. Bioresource Technology, 102(19), 8799-8806. doi:10.1016/j.biortech.2011.07.014Kurano, N., & Miyachi, S. (2005). Selection of microalgal growth model for describing specific growth rate-light response using extended information criterion. Journal of Bioscience and Bioengineering, 100(4), 403-408. doi:10.1263/jbb.100.403McGinn, P. J., Dickinson, K. E., Park, K. C., Whitney, C. G., MacQuarrie, S. P., Black, F. J., … O’Leary, S. J. B. (2012). Assessment of the bioenergy and bioremediation potentials of the microalga Scenedesmus sp. AMDD cultivated in municipal wastewater effluent in batch and continuous mode. Algal Research, 1(2), 155-165. doi:10.1016/j.algal.2012.05.001Reynolds, C. S. (2006). The Ecology of Phytoplankton. doi:10.1017/cbo9780511542145Rouzic, B. L., & Bertru, G. (1997). Phytoplankton community growth in enrichment bioassays: Possible role of the nutrient intracellular pools. Acta Oecologica, 18(2), 121-133. doi:10.1016/s1146-609x(97)80069-0Ruiz-Martinez, A., Serralta, J., Pachés, M., Seco, A., & Ferrer, J. (2014). Mixed microalgae culture for ammonium removal in the absence of phosphorus: Effect of phosphorus supplementation and process modeling. Process Biochemistry, 49(12), 2249-2257. doi:10.1016/j.procbio.2014.09.002Ruiz-Martínez, A., Serralta, J., Romero, I., Seco, A., & Ferrer, J. (2015). Effect of intracellular P content on phosphate removal in Scenedesmus sp. Experimental study and kinetic expression. Bioresource Technology, 175, 325-332. doi:10.1016/j.biortech.2014.10.081Ruiz-Martínez, A., Serralta, J., Seco, A., & Ferrer, J. (2015). Effect of temperature on ammonium removal in Scenedesmus sp. Bioresource Technology, 191, 346-349. doi:10.1016/j.biortech.2015.05.070Singh, G., & Thomas, P. B. (2012). Nutrient removal from membrane bioreactor permeate using microalgae and in a microalgae membrane photoreactor. Bioresource Technology, 117, 80-85. doi:10.1016/j.biortech.2012.03.125Wang, B., & Lan, C. Q. (2011). Biomass production and nitrogen and phosphorus removal by the green alga Neochloris oleoabundans in simulated wastewater and secondary municipal wastewater effluent. Bioresource Technology, 102(10), 5639-5644. doi:10.1016/j.biortech.2011.02.054Wang, L., Min, M., Li, Y., Chen, P., Chen, Y., Liu, Y., … Ruan, R. (2009). Cultivation of Green Algae Chlorella sp. in Different Wastewaters from Municipal Wastewater Treatment Plant. Applied Biochemistry and Biotechnology, 162(4), 1174-1186. doi:10.1007/s12010-009-8866-7Wu, Y.-H., Li, X., Yu, Y., Hu, H.-Y., Zhang, T.-Y., & Li, F.-M. (2013). An integrated microalgal growth model and its application to optimize the biomass production of Scenedesmus sp. LX1 in open pond under the nutrient level of domestic secondary effluent. Bioresource Technology, 144, 445-451. doi:10.1016/j.biortech.2013.06.065Wu, Y.-H., Hu, H.-Y., Yu, Y., Zhang, T.-Y., Zhu, S.-F., Zhuang, L.-L., … Lu, Y. (2014). Microalgal species for sustainable biomass/lipid production using wastewater as resource: A review. Renewable and Sustainable Energy Reviews, 33, 675-688. doi:10.1016/j.rser.2014.02.026Xin, L., Hong-ying, H., & Yu-ping, Z. (2011). Growth and lipid accumulation properties of a freshwater microalga Scenedesmus sp. under different cultivation temperature. Bioresource Technology, 102(3), 3098-3102. doi:10.1016/j.biortech.2010.10.05

    Effect of intracellular P content on phosphate removal in Scenedesmus sp. Experimental study and kinetic expression

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    The present work determines the effect of phosphorus content on phosphate uptake rate in a mixed culture of Chlorophyceae in which the genus Scenedesmus dominates. Phosphate uptake rate was determined in eighteen laboratory batch experiments, with samples taken from a progressively more P-starved culture in which a minimum P content of 0.11% (w/w) was achieved. The results obtained showed that the higher the internal biomass P content, the lower the phosphate removal rate. The highest specific phosphate removal rate was 6.5 mgPO4 P gTSS -1 h -1 . Microalgae with a P content around 1% (w/w) attained 10% of this highest removal rate, whereas those with a P content of 0.6% (w/w) presented 50% of the maximum removal rate. Different kinetic expressions were used to reproduce the experimental data. Best simulation results for the phosphate uptake process were obtained combining Steele equation and Hill function to represent the effect of light and intracellular phosphorus content, respectively.This research work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO, CTM2011-28595-C02-01/02) jointly with the European Regional Development Fund (ERDF) which are gratefully acknowledged.Ruiz Martínez, A.; Serralta Sevilla, J.; Romero Gil, I.; Seco Torrecillas, A.; Ferrer, J. (2015). Effect of intracellular P content on phosphate removal in Scenedesmus sp. Experimental study and kinetic expression. Bioresource Technology. 175:325-332. https://doi.org/10.1016/j.biortech.2014.10.08132533217

    Edaphic characterization and distribution of 137Cs of representative soil profiles on mountainous Mediterranean agroecosystems

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    19 Pags.- 3 Tabls.- 5 Figs.[ES] Caracterizar los suelos y conocer sus propiedades fisicoquímicas es fundamental para interpretar los datos de 137Cs y evaluar las implicaciones que el tipo y uso de suelo, agrario, ganadero o forestal, tienen sobre el comportamiento del radioisótopo en el suelo. En este trabajo se han caracterizado suelos representativos de agrosistemas mediterráneos de montaña mediante la apertura de calicatas, el estudio detallado de sus propiedades fisicoquímicas, y el análisis por difracción de rayos X de perfiles de suelo. Asimismo, para evaluar la repercusión del uso del suelo sobre el contenido y distribución del radioisótopo, sus implicaciones sobre los procesos de pérdida de suelo, y la posible transferencia del 137Cs a las plantas, se han muestreado 13 perfiles seccionados de suelos agrícolas y forestales en Calcisoles, Leptosoles, Regosoles, Gypsisoles y Gleysoles. Se observó un amplio rango de variación tanto de las principales propiedades fisicoquímicas de suelo como del contenido de 137Cs, que se relacionó directa y significativamente con la materia orgánica. Los valores de 137Cs más altos se registraron en Leptosoles no cultivados en suelos forestales, en los que se observó una distribución del radioisótopo exponencialmente decreciente con la profundidad, mientras que los Gypsisoles y Regosoles cultivados registraron las concentraciones más bajas, con perfiles homogéneos en profundidad por efecto del laboreo. Los resultados de esta investigación evidencian el efecto del uso y tipo de suelo en la concentración de la actividad del radioisótopo, y son de interés para la correcta aplicación del 137Cs como técnica para cuantificar la pérdida de suelo en agrosistemas mediterráneos.[EN] An accurate characterization of soils and good knowledge of the soil physicochemical properties is the key to understanding 137Cs data and assesses the effect of soil type and different land uses on the behavior of the radionuclide 137Cs in the soils. In this research, representative soils of mountainous Mediterranean agroecosystems have been characterized through the study of soil pits, a detailed determination of physicochemical soil properties and the analysis by X-ray diffraction of soil profiles. Furthermore, to assess the impact of Iand use on the content and distribution of 137Cs, its implications on the soil Ioss processes, and the 137Cs transfer to plants, 13 sectioned soil profiles in agricultural and forestry soils, in Calcisois, Leptosois, Regosois, Gypsisols and Gleysois, have been sampled. The physicochemical soil properties varied widely and also the content of 137Cs, which was significantly positively correlated with organic matter. The highest values of 137Cs were found in uncultivated Leptosols under forest soils, with the highest concentration in the topsoil and a sharp decay with depth, while the lowest values of 137Cs were found in cultivated Gypsisols and Regosols, in which the radionuclide was distributed homogeneously throughout the soil profile by tillage effect. Information gained with this research demonstrated the effect of soil type and land use in the content of 137Cs on the soil, and is of interest for the correct application of the 137Cs technique to quantify soil loss in Mediterranean agroecosystems.Trabajo financiado por el proyecto de la CICYT, EROMED (CGL2O1 1 -25486/BTE).Peer reviewe

    Reduction of CO2-emissions in ceramic tiles manufacture by combining energy-saving measures

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    Ceramic tile manufacture requires a great quantity of energy, mainly in the form of heat. The heat is principally used in the kilns and dryers, and it is obtained by natural gas combustion. The increasing cost of natural gas, as well as the application of a new gas tax, the new legislation in regard to emissions trading, and the difficult current economic situation have driven the ceramic tile sector to implement energy-saving actions in the production process with the twofold aim of reducing energy costs and abating carbon dioxide emissions. One such course of action is the European project REDUCER, funded by the European Commission and led by Azulev S.A.U., in which the Instituto de Tecnología Cerámica (ITC) also participates. This project seeks to implement energy-saving actions in company kilns and dryers in order to lower natural gas consumption and reduce carbon dioxide emissions in the tile manufacturing process. One of the saving actions envisaged is the installation of a system of waste heat recovery from one of the company kilns to the tile body dryers. This new waste heat recovery system is to be added to and will complement the already existing system at the company, thus achieving maximum heat recovery from the kiln stacks. The recovered heat will go entirely to the green tile body dryers, thus reducing natural gas consumption in the dryers. The designed installation seeks to recover 600 kW heat from the stacks of one of the kilns, entailing a natural gas saving of more than 120 k€/year and suppressing the emission into the atmosphere of 720 tons of CO2/year, savings that are to be added to those attained with other energy-saving measures. This paper describes the energy-saving actions implemented at the company, as well as the resulting energy savings

    Carbon nanotube film electrodes with acrylic additives: Blocking electrochemical charge transfer reactions

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    Carbon nanotubes (CNTs) processed into conductive films by liquid phase deposition technologies reveal increasing interest as electrode components in electrochemical device platforms for sensing and energy storage applications. In this work we show that the addition of acrylic latex to water-based CNT inks not only favors the fabrication of stable and robust flexible electrodes on plastic substrates but, moreover, sensitively enables the control of their electrical and electrochemical transport properties. Importantly, within a given concentration range, the acrylic additive in the films, being used as working electrodes, effectively blocks undesired faradaic transfer reactions across the electrode–electrolyte interface while maintaining their capacitance response as probed in a three-electrode electrochemical device configuration. Our results suggest a valuable strategy to enhance the chemical stability of CNT film electrodes and to suppress non-specific parasitic electrochemical reactions of relevance to electroanalytical and energy storage applications

    Magnetic-responsive hydrogels for cartilage tissue engineering

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    Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013)The use of magnetic nanoparticles (MNPs) has been explored as an alternative approach to overcome current limitations of regenerative medicine strategies. Cell engineering approaches where MNPs are incorporated within three-dimensional constructs, such as scaffolds or hydrogels may constitute a novel and attractive approach towards the development of a magnetically-responsive system. These systems would enable remote controlled actions over tissue engineered constructs in vitro and in vivo. Moreover, growing evidence suggests that the application of a magnetic field may enhance biological performance over commonly used static culture conditions providing stimulation for cell proliferation, migration and differentiation. In this work we analyze the role of magnetic stimulation on the behavior of human adipose derived stem cells (hASCs) laden in k-carrageenan hydrogels aiming at cartilage tissue engineering approaches. Thermo-responsive natural-based κ-carrageenan hydrogels were used as 3D templates since previous studies(1) report the adequate environment provided by these materials to support the viability and chondrogenic differentiation of several types of cells

    Comentario a ¿Son necesarios los electrocardiogramas en el preoperatorio y para quién?

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    Comentarios a MJ Bonet ¿Son necesarios los electrocardiogramas en el preoperatorio y para quién? Rev electron AnestesiaR 2009; Volumen 1 (8):34

    Ultralow background periods in CAST Micromegas detectors and tests in the Canfranc underground laboratory

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    Yıldız, Süleyman Cenk (Dogus Author)Micromegas detectors have shown a low and stable background level in the CAST experiment due to their low radioactive materials, good energy resolution and spatial resolution. Since 2008, four ultralow background periods have been observed with the new microbulk detectors. During these periods, the background level reduced one order of magnitude, reaching a value around 10-7 s-1 keV-1 cm-2 between 2 and 7 keV. In all cases, the intensity of the three fluorescence lines (at 3, 6 and 8 keV) presented at the background spectrum reduced but the relative ratio remained stable. To clarify the origin of these periods and might determine the ultimate background level of these readouts, a CAST-like detector has been installed at the Canfranc Underground Laboratory. The actual level is compatible with the one measured in CAST. A new Micromegas detectors is being developped for working in CAST experiment during 2011, based on the conclusions of this work
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