2,656 research outputs found

    Differences into HT and HTO concentrations in air into the Western Mediterranean Basin and Continental Europe and Safety Related Issues.

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    Real time Tritium concentrations in air in two chemical forms, HT and HTO, coming from an ITER-like fusion reactor as source were coupled the European Centre Medium Range Weather Forecast (ECMWF) numerical model with the Lagrangian Atmospheric-particle dispersion model FLEXPART. This tool was analyzed in nominal tritium discharge operational reference and selected incidental conditions affecting the Western Mediterranean Basin during 45 days during summer 2010 together with surface “wind observations” or weather data based in real hourly observations of wind direction and velocity providing a real approximation of the tritium behavior after the release to the atmosphere from a fusion reactor. From comparison with NORMTRI - a code using climatologically sequences as input - over the same area, the real time results have demonstrated an apparent overestimation of the corresponding climatologically sequence of Tritium concentrations in air outputs, at several distances from the reactor. For this purpose two development patterns were established. The first one was following a cyclonic circulation over the Mediterranean Sea and the second one was based on the plume delivered over the Interior of the Iberian Peninsula and Continental Europe by another stabilized circulation corresponding to a High Pressure System. One of the important remaining activities defined then, was the qualification tool. In order to validate the model of ECMWF/FLEXPART we have developed of a new complete data base of tritium concentrations for the months from November 2010 to March 2011 and defined a new set of four patterns of HT transport in air, in each case using real boundary conditions: stationary to the North, stationary to the South, fast and very fast displacement. Finally the differences corresponding to those four early patterns (each one in assessments 1 and 2) has been analyzed in terms of the tuning of safety related issues and taking into account the primary phase o- - f tritium modeling, from its discharge to the atmosphere to the deposition on the ground, will affect to the complete tritium environmental pathway altering the chronic dose by absorption, reemission and ingestion both from elemental tritium, HT and from the oxide of tritium, HT

    Hypertriglyceridemia, Metabolic Syndrome, and Cardiovascular Disease in HIV-Infected Patients: Effects of Antiretroviral Therapy and Adipose Tissue Distribution

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    The use of combination antiretroviral therapy (CART) in HIV-infected patients has resulted in a dramatic decline in AIDS-related mortality. However, mortality due to non-AIDS conditions, particularly cardiovascular disease (CVD) seems to increase in this population. CART has been associated with several metabolic risk factors, including insulin resistance, low HDL-cholesterol, hypertriglyceridemia and postprandial hyperlipidemia. In addition, HIV itself, as well as specific antiretroviral agents, may further increase cardiovascular risk by interfering with endothelial function. As the HIV population is aging, CVD may become an increasingly growing health problem in the future. Therefore, early diagnosis and treatment of cardiovascular risk factors is warranted in this population. This paper reviews the contribution of both, HIV infection and CART, to insulin resistance, postprandial hyperlipidemia and cardiovascular risk in HIV-infected patients. Strategies to reduce cardiovascular risk are also discussed

    Consequences of different meteorological scenarios in the environmental impact assessment of tritium in air

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    The environmental impact of systems managing large (kg) tritium amount represents a public scrutiny issue for the next coming fusion facilities as ITER and DEMO. Furthermore, potentially new dose limits imposed by international regulations (ICRP) shall impact next coming devices designs and the overall costs of fusion technology deployment. Refined environmental tritium dose impact assessment schemes are then overwhelming. Detailed assessments can be procured from the knowledge of the real boundary conditions of the primary tritium discharge phase into atmosphere (low levels) and into soils. Lagrangian dispersion models using real-time meteorological and topographic data provide a strong refinement. Advance simulation tools are being developed in this sense. The tool integrates a numerical model output records from European Centre for Medium range Weather Forecast (ECMWF) with a lagrangian atmospheric dispersion model (FLEXPART). The composite model ECMWF/FLEXTRA results can be coupled with tritium dose secondary phase pathway assessment tools. Nominal tritium discharge operational reference and selected incidental ITER-like plant systems tritium form source terms have been assumed. The realtime daily data and mesh-refined records together with lagrangian dispersion model approach provide accurate results for doses to population by inhalation or ingestion in the secondary phas

    Validation of real time dispersion of Tritium clouds over the Western Mediterranean Basin in different assesments

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    Real time Tritium concentrations in air coming from an ITER-like reactor as source were coupled the European Centre Medium Range Weather Forecast (ECMWF) numerical model with the lagrangian atmospheric dispersion model FLEXPART. This tool ECMWF/FLEXPART was analyzed in normal operating conditions in the Western Mediterranean Basin during 45 days at summer 2010. From comparison with NORMTRI plumes over Western Mediterranean Basin the real time results have demonstrated an overestimation of the corresponding climatologically sequence Tritium concentrations in air outputs, at several distances from the reactor. For these purpose two clouds development patterns were established. The first one was following a cyclonic circulation over the Mediterranean Sea and the second one was based in the cloud delivered over the Interior of the Iberian Peninsula by another stabilized circulation corresponding to a High. One of the important remaining activities defined then, was the tool qualification. The aim of this paper is to present the ECMWF/FLEXPART products confronted with Tritium concentration in air data. For this purpose a database to develop and validate ECMWF/FLEXPART tritium in both assessments has been selected from a NORMTRI run. Similarities and differences, underestimation and overestimation with NORMTRI will allowfor refinement in some features of ECMWF/FLEXPAR

    Equilibrium constants of triethanolamine in major seawater salts

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    Acid–base equilibrium constants of triethanolamine (TEA) have been determined by potentiometric titrations with a glass electrode, at 25 °C. Ionic strength was kept constant with only one electrolyte (using one of these salts: NaCl, KCl, MgCl2 or CaCl2), with binary mixtures of MgCl2 and CaCl2, and finally, in a solution with a composition approximately similar to that of natural seawater without sulfate. Equilibrium constants have been expressed in function of ionic strength by means of Pitzer equations and interaction parameters proposed in this theory have been obtained. It has been found that acid–base behaviour of TEA depends greatly on the salt used: basicity of TEA is decreased by CaCl2, while it is increased by the other electrolytes used in this work

    Effects of heavy Majorana neutrinos on lepton flavor violating processes

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    The observation of lepton flavor violating processes at colliders could be a clear signal of a non-minimal neutrino sector. We define a 5-parameter model with a pair of TeV fermion singlets and arbitrary mixings with the three active neutrino flavors. Then we analyze several flavor violating transitions (ℓ→ℓ′γ,ℓ′ℓ′′ℓ¯′′′ or μ−e conversions in nuclei) and Z→ℓ¯ℓ′ decays induced by the presence of heavy neutrinos. In particular, we calculate all the one-loop contributions to these processes and present their analytic expressions. We focus on the genuine effects of the heavy Majorana masses, comparing the results in that case with the ones obtained when the two heavy neutrinos define a Dirac field. Finally, we use our results to update the bounds on the heavy-light mixings in the neutrino sector.This work was supported in part by the Spanish Ministry of Science, Innovation and Universities, under Grant No. FPA2016-78220-C3-1,2,3- P (fondos FEDER), and Junta de Andalucía, Grants No. FQM 101 and No. SOMM17/6104/UGR. G. H. T. wants to acknowledge financial support from Conacyt through the program “Estancia Postdoctoral en el Extranjero.” The work of P. R. has been partially funded by Conacyt through the Project No. 250628 (Ciencia Básica) and Fondo SEP-Cinvestav 2018 (Project No. 142)

    European Registry on Helicobacter pylori Management: Effectiveness of First and Second-Line Treatment in Spain

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    The management of Helicobacter pylori infection has to rely on previous local effectiveness due to the geographical variability of antibiotic resistance. The aim of this study was to evaluate the effectiveness of first and second-line H. pylori treatment in Spain, where the empirical prescription is recommended. A multicentre prospective non-interventional registry of the clinical practice of European gastroenterologists concerning H. pylori infection (Hp-EuReg) was developed, including patients from 2013 until June 2019. Effectiveness was evaluated descriptively and through a multivariate analysis concerning age, gender, presence of ulcer, proton-pump inhibitor (PPI) dose, therapy duration and compliance. Overall, 53 Spanish hospitals were included, and 10,267 patients received a first-line therapy. The best results were obtained with the 10-day bismuth single-capsule therapy (95% cure rate by intention-to-treat) and with both the 14-day bismuth-clarithromycin quadruple (PPI-bismuth-clarithromycin-amoxicillin, 91%) and the 14-day non-bismuth quadruple concomitant (PPI-clarithromycin-amoxicillin-metronidazole, 92%) therapies. Second-line therapies were prescribed to 2448 patients, with most-effective therapies being the triple quinolone (PPI-amoxicillin-levofloxacin/moxifloxacin) and the bismuth-levofloxacin quadruple schemes (PPI-bismuth-levofloxacin-amoxicillin) prescribed for 14 days (92%, 89% and 90% effectiveness, respectively), and the bismuth single-capsule (10 days, 88.5%). Compliance, longer duration and higher acid inhibition were associated with higher effectiveness. “Optimized” H. pylori therapies achieve over 90% success in Spain

    Experimental study of a double-diffusive system: application to solar ponds

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    A salt gradient solar pond is an artificial device used to collect and store solar thermal energy. A non-convective zone, in the middle of the solar pond, reduces thermal losses and allows a significant rise of temperature in the saltier lower zone where the solar thermal energy is stored. The non-convective zone, also named gradient zone, is characterized by a salinity gradient that increase the density with depth promoting the stability of this layer. The absorption of solar radiation in the pond creates a destabilizing temperature gradient in the non-convective zone that contradicts the density gradient. The different molecular diffusivities of heat and salt and the opposing effects on the vertical density distribution of the two gradients can lead to double-diffusive convection phenomena. In this context, a double-diffusive system has been studied experimentally in laboratory by heating a stratified salt layer from below. The instabilities caused by the destabilizing temperature gradients lead to the formation of convective zones separated from purely diffusive zone by thin interfaces. The main goals of this work are the study of the evolution of the double-diffusive layer and the analysis of the behaviour of the diffusive interface near conditions for which instabilities appear

    Archaeometalurgical analysis and archaeological contextualization of a bronze spearhead from Gralheira (Muro Mountain Range, Baltar, Paredes, North Portugal).

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    Este trabalho visa dar a conhecer o contexto de achado e a composição química de uma ponta de lança de alvado curto e de folha ligeiramente losângica com nervura central, inserível no Bronze Final e inédita. Esta foi encontrada na serra do Muro, freguesia de Baltar, concelho de Paredes, distrito do Porto. A serra do Muro corresponde a um monte com uma implantação orográfica dominante na região sobre os vales dos rios Ferreira e Sousa, este afluente da margem norte da bacia do Douro, em área rica em recursos primários e secundários de estanho. No topo deste acidente geomorfológico foi edificado um povoado proto-histórico que figura na literatura arqueológica especialmente pelo grande perímetro e espessura das suas muralhas pétreas. Apesar da proximidade destes dois contextos arqueológicos não há qualquer indicação precisa de que estejam vinculados, podendo esta peça constituir um depósito. Não sendo muito frequente o achado de pontas de lança no NO português, conhecem-se todavia alguns contextos, todos eles correspondentes a depósitos. É o caso da ponta de lança de Badim, de morfologia similar, que apareceu enterrada na base do monte cónico de Nossa Senhora da Graça, em Monção, e desvinculada do castro aí existente, localizado, aliás, em vertente oposta. Outros achados similares associados a montes são os do Outeiro do Rego, em Lama Chã, Montalegre, e o da Quinta do Telhado, no Monte da Penha, em Guimarães, ambos associados a afloramentos. Apesar das diversas pontas de lança conhecidas no NW português, apenas as duas de Vale Travesso, em Montalegre, foram alvo de análise de composição química (BOTTAINI 2012: 49-52), pelo que os resultados das análises arqueometalúrgicas obtidas por espectrometria de fluorescência de raios X da ponta de lança do Muro, contribuirão, certamente, para o conhecimento da metalurgia do Bronze Final do NO.$ is work was carried out under the project: Natural spaces, architectures, rock art and depositions from the Late Prehistory of the Western front of Cen-tral and Northern Portugal: from actions to meanings - ENARDAS (reference PTDC/HIS-ARQ/112983/2009), su-pported by FCT, COMPETE and FEDER and Bronze Age Hoards of the Western Atlantic facade of Iberia between the Vouga and Ulla Rivers: Contexts and In-terpretationsinfo:eu-repo/semantics/acceptedVersio
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