3,517 research outputs found

    Diffuse Soil Co2 Flux To Assess The Reliability Of Co2 Storage In The Mazarrón-Gañuelas Tertiary Basin (Spain)

    Get PDF
    Geological storage of CO2 is nowadays internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize its effects on the global climatology. One of the main options is to store the CO2 in deep saline aquifers at more than 800 m depth, because it achieves its supercritical state. Among the most important aspects concerning the performance assessment of a deep CO2 geological repository is the evaluation of the CO2 leakage rate from the chosen storage geological formation. Therefore, it is absolutely necessary to increase the knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths for CO2 and the physico-mechanical resistance of the sealing formation. Furthermore, the quantification of the CO2 leakage rate is essential to evaluate its effects on the environment. One way to achieve this objective is to study of CO2 leakage on natural analogue systems, because they can provide useful information about the natural performance of the CO2, which can be applied to an artificial CO2 geological storage. This work is focused on the retention capacity of the cap-rock by measuring the diffuse soil CO2 flux in a site selected based on: i) the presence of a natural and deep CO2 accumulation; ii) its structural geological characteristics; and iii) the nature of the cap-rocks. This site is located in the so-called Mazarrón-Gañuelas Tertiary Basin, in the Guadalentin Valley, province of Murcia (Spain) Therefore the main objective of this investigation has been to detect the possible leakages of CO2 from a deep saline aquifer to the surface in order to understand the capability of this area as a natural analogue for Carbon Capture and Sequestration (CCS). The results obtained allow to conclude that the geological sealing formation of the basin seems to be appropriate to avoid CO2 leakages from the storage formation

    SemisĂ­ntesis estereoselectiva del 3-b-D-glucĂłsido del sitosterol, principio antihiperglucemiante de Ceutaurea seridis L. var. Maritima Lge.

    Get PDF
    The stereoselective semisynthesis conditions have been established to obtain β-sitosterol 3-β-D-glucoside, which is an antihyperglycemic principe isolated from the aerial part of Centaurea seridis L. var. maritima Lge. The yield was 11,6 per cent, much higher than the one obtained from the vegetal species, which was 0,03 per cent.Se han establecido las condiciones operatorias para la semisíntesis estereoselectiva del 3-β-D-glucósido del β -sitosterol, principio antihiperglucemiante aislado de la sumidad florida de Centaurea serídis L. varo maritima Lge. El rendimiento del proceso fue de 11,6 por ciento, netamente superior al obtenido a partir de la especie vegetal que fue 0,03 por ciento

    SemisĂ­ntesis estereoselectiva del 3-b-D-glucĂłsido del sitosterol, principio antihiperglucemiante de Ceutaurea seridis L. var. Maritima Lge.

    Get PDF
    Se han establecido las condiciones operatorias para la semisíntesis estereoselectiva del 3-β-D-glucósido del β -sitosterol, principio antihiperglucemiante aislado de la sumidad florida de Centaurea serídis L. varo maritima Lge. El rendimiento del proceso fue de 11,6 por ciento, netamente superior al obtenido a partir de la especie vegetal que fue 0,03 por ciento.The stereoselective semisynthesis conditions have been established to obtain β -sitosterol 3-β D-glucoside, which is an antihyperglycemic principe isolated from the aerial part of Centaurea seridis L. var. maritima Lge. The yield was 11,6 per cent, much higher than the one obtained from the vegetal species, which was 0,03 per cent

    Route Towards a Label-free Optical Waveguide Sensing Platform Based on Lossy Mode Resonances

    Get PDF
    According to recent market studies of the North American company Allied Market Research, the field of photonic sensors is an emerging strategic field for the following years and it is expected to garner $18 billion by 2021. The integration of micro and nanofabrication technologies in the field of sensors has allowed the development of new technological concepts such as lab-on-a-chip, which have achieved extraordinary advances in terms of detection and applicability, for example in the field of biosensors. This continuous development has allowed that equipment consisting of many complex devices that occupied a whole room a few years ago, at present it is possible to handle them in the palm of the hand; that formerly long duration processes are carried out in a matter of milliseconds and that a technology previously dedicated solely to military or scientific uses is available to the vast majority of consumers. The adequate combination of micro and nanostructured coatings with optical fiber sensors has permitted us to develop novel sensing technologies, such as the first experimental demonstration of lossy mode resonances (LMRs) for sensing applications, with more than one hundred citations and related publications in high rank journals and top conferences. In fact, fiber optic LMR-based devices have been proven as devices with one of the highest sensitivity for refractometric applications. Refractive index sensitivity is an indirect and simple indicator of how sensitive the device is to chemical and biological species, topic where this proposal is focused. Consequently, the utilization of these devices for chemical and biosensing applications is a clear opportunity that could open novel and interesting research lines and applications as well as simplify current analytical methodologies. As a result, on the basis of our previous experience with LMR based sensors to attain very high sensitivities, the objective of this paper is presenting the route for the development of label-free optical waveguide sensing platform based on LMRs that enable to explore the limits of this technology for bio-chemosensing applications

    Tunable Sensitivity in Long Period Fiber Gratings During Mode Transition With Low Refractive Index Intermediate Layer

    Get PDF
    Double-clad fibers where the second cladding has a lower refractive index than the first cladding, prove to be ideal structures for potentiating and tuning the sensitivity in long-period fiber gratings (LPFGs) operating in mode transition. When a thin film is deposited on the optical fiber, the second cladding performs acts as a barrier that initially prevents the transition to guidance in the thin film of one of the modes guided in the first cladding. Finally, the transition to guidance occurs with a sensitivity increase, in analogy to the tunnel effect observed in semiconductors. This improvement has been demonstrated both as a function of the thin film thickness and the surrounding medium refractive index, with enhancement factors of 4 and 2, respectively. This idea reinforces the performance of LPFGs, adding a new degree of freedom to the mode transition and the dispersion turning point phenom- ena. Moreover, the control of the variation of the effective index of cladding modes could be applied in other structures, such as tilted-fiber gratings or evanescent wave sensors

    The active living gender's gap challenge: 2013-2017 Eurobarometers physical inactivity data show constant higher prevalence in women with no progress towards global reduction goals

    Get PDF
    BACKGROUND: The World Health Organization (WHO) considers physical inactivity (PIA) as a critical noncommunicable factor for disease and mortality, affecting more women than men. In 2013, the WHO set a 10% reduction of the PIA prevalence, with the goal to be reached by 2025. Changes in the 2013-2017 period of physical inactivity prevalence in the 28 European Union (EU) countries were evaluated to track the progress in achieving WHO 2025 target. METHODS: In 2013 and 2017 EU Special Eurobarometers, the physical activity levels reported by the International Physical Activity Questionnaire of 53,607 adults were analyzed. Data were considered as a whole sample and country-by-country. A χ2 test was used to analyze the physical inactivity prevalence (%) between countries, analyzing women and men together and separately. Additionally, PIA prevalence was analyzed between years (2013-2017) for the overall EU sample and within-country using a Z-Score for two population proportions. RESULTS: The PIA prevalence increased between 2013 and 2017 for the overall EU sample (p <  0.001), and for women (p = 0.04) and men (p < 0.001) separately. Data showed a higher PIA prevalence in women versus men during both years (p <  0.001). When separately considering changes in PIA by gender, only Belgium's women and Luxembourg's men showed a reduction in PIA prevalence. Increases in PIA prevalence over time were observed in women from Austria, Croatia, Germany, Lithuania, Malta, Portugal, Romania, and Slovakia and in men from Bulgaria, Croatia, Czechia, Germany, Italy, Lithuania, Portugal, Romania, Slovakia, and Spain. CONCLUSIONS: PIA prevalence showed an overall increase across the EU and for both women and men between 2013 and 2017, with higher rates of PIA reported for women versus men during both years. PIA prevalence was reduced in only Belgium's women and Luxembourg's men. Our data indicate a limited gender-sensible approach while tacking PIA prevalence with no progress reaching global voluntary reductions of PIA for 2025
    • …
    corecore