The importance of meteorological scales to forecast air pollution scenarios on coastal complex terrain

Some of the meteorological approaches commonly considered in urban air pollution models do not take into account the importance of the smaller scales in the meteorology of complex-terrain coastal sites. The aim of this work is to estimate the impact of using the proper meteorological scales when simulating the behaviour of the pollutant concentrations emitted in the lower layers over coastal complex terrain areas. The availability of experimental measurements of a power plant plume near the Castellón conurbation (on the Spanish Mediterranean coast) has allowed us to use this plume as a tracer of opportunity of the lower atmosphere to check the results of a simulation exercise using the RAMS mesoscale model coupled to the HYPACT particle model. The results obtained show that in a complex-terrain coastal site, because of the strong effect of the meteorological interactions between the different scales on the integral advection and the turbulent dispersion of pollutants, using an inadequate scale to solve the meteorology can result in a very big gap in the simulation of lower-layer pollutant behaviour at urban scales

Transitional dispersive scenarios driven by mesoscale flows on complex terrain under strong dry convective conditions

By experimentation and modelling, this paper analyses the atmospheric dispersion of the SO<sub>2</sub> emissions from a power plant on complex terrain under strong convective conditions, describing the main dispersion features as an ensemble of "stationary dispersive scenarios" and reformulating some "classical" dispersive concepts to deal with the systematically monitored summer dispersive scenarios in inland Spain. The results and discussions presented arise from a statistically representative study of the physical processes associated with the multimodal distribution of pollutants aloft and around a 343-m-tall chimney under strong dry convective conditions in the Iberian Peninsula. This paper analyses the importance of the identification and physical implications of transitional periods for air quality applications. The indetermination of a transversal plume to the preferred transport direction during these transitional periods implies a small (or null) physical significance of the classical definition of horizontal standard deviation of the concentration distribution

Real-Time and Low-Cost Sensing Technique Based on Photonic Bandgap Structures

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.36.002707. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] A technique for the development of low-cost and high-sensitivity photonic biosensing devices is proposed and experimentally demonstrated. In this technique, a photonic bandgap structure is used as transducer, but its readout is performed by simply using a broadband source, an optical filter, and a power meter, without the need of obtaining the transmission spectrum of the structure; thus, a really low-cost system and real-time results are achieved. Experimental results show that it is possible to detect very low refractive index variations, achieving a detection limit below 2 x 10(-6) refractive index units using this low-cost measuring technique. (C) 2011 Optical Society of America[This work was funded by the Spanish Ministerio de Ciencia e Innovacion (MICINN) under contracts TEC2008-06333, JCI-009-5805, and TEC2008-05490. Support by the Universidad Politecnica de Valencia through program PAID-06-09 and the Conselleria d'Educacio through program GV-2010-031 is acknowledged.García Castelló, J.; Toccafondo, V.; Pérez Millán, P.; Sánchez Losilla, N.; Cruz, JL.; Andres, MV.; García-Rupérez, J. (2011). Real-Time and Low-Cost Sensing Technique Based on Photonic Bandgap Structures. Optics Letters. 36(14):2707-2709. https://doi.org/10.1364/OL.36.002707S270727093614Fan, X., White, I. M., Shopova, S. I., Zhu, H., Suter, J. D., & Sun, Y. (2008). Sensitive optical biosensors for unlabeled targets: A review. Analytica Chimica Acta, 620(1-2), 8-26. doi:10.1016/j.aca.2008.05.022Homola, J., Yee, S. S., & Gauglitz, G. (1999). Surface plasmon resonance sensors: review. Sensors and Actuators B: Chemical, 54(1-2), 3-15. doi:10.1016/s0925-4005(98)00321-9Kersey, A. D., Davis, M. A., Patrick, H. J., LeBlanc, M., Koo, K. P., Askins, C. G., … Friebele, E. J. (1997). Fiber grating sensors. Journal of Lightwave Technology, 15(8), 1442-1463. doi:10.1109/50.618377De Vos, K., Bartolozzi, I., Schacht, E., Bienstman, P., & Baets, R. (2007). Silicon-on-Insulator microring resonator for sensitive and label-free biosensing. Optics Express, 15(12), 7610. doi:10.1364/oe.15.007610Iqbal, M., Gleeson, M. A., Spaugh, B., Tybor, F., Gunn, W. G., Hochberg, M., … Gunn, L. C. (2010). Label-Free Biosensor Arrays Based on Silicon Ring Resonators and High-Speed Optical Scanning Instrumentation. IEEE Journal of Selected Topics in Quantum Electronics, 16(3), 654-661. doi:10.1109/jstqe.2009.2032510Xu, D.-X., Vachon, M., Densmore, A., Ma, R., Delâge, A., Janz, S., … Schmid, J. H. (2010). Label-free biosensor array based on silicon-on-insulator ring resonators addressed using a WDM approach. Optics Letters, 35(16), 2771. doi:10.1364/ol.35.002771Skivesen, N., Têtu, A., Kristensen, M., Kjems, J., Frandsen, L. H., & Borel, P. I. (2007). Photonic-crystal waveguide biosensor. Optics Express, 15(6), 3169. doi:10.1364/oe.15.003169Lee, M. R., & Fauchet, P. M. (2007). Nanoscale microcavity sensor for single particle detection. Optics Letters, 32(22), 3284. doi:10.1364/ol.32.003284García-Rupérez, J., Toccafondo, V., Bañuls, M. J., Castelló, J. G., Griol, A., Peransi-Llopis, S., & Maquieira, Á. (2010). Label-free antibody detection using band edge fringes in SOI planar photonic crystal waveguides in the slow-light regime. Optics Express, 18(23), 24276. doi:10.1364/oe.18.024276Toccafondo, V., García-Rupérez, J., Bañuls, M. J., Griol, A., Castelló, J. G., Peransi-Llopis, S., & Maquieira, A. (2010). Single-strand DNA detection using a planar photonic-crystal-waveguide-based sensor. Optics Letters, 35(21), 3673. doi:10.1364/ol.35.003673Luff, B. J., Wilson, R., Schiffrin, D. J., Harris, R. D., & Wilkinson, J. S. (1996). Integrated-optical directional coupler biosensor. Optics Letters, 21(8), 618. doi:10.1364/ol.21.000618Sepúlveda, B., Río, J. S. del, Moreno, M., Blanco, F. J., Mayora, K., Domínguez, C., & Lechuga, L. M. (2006). Optical biosensor microsystems based on the integration of highly sensitive Mach–Zehnder interferometer devices. Journal of Optics A: Pure and Applied Optics, 8(7), S561-S566. doi:10.1088/1464-4258/8/7/s41Densmore, A., Vachon, M., Xu, D.-X., Janz, S., Ma, R., Li, Y.-H., … Schmid, J. H. (2009). Silicon photonic wire biosensor array for multiplexed real-time and label-free molecular detection. Optics Letters, 34(23), 3598. doi:10.1364/ol.34.003598Povinelli, M. L., Johnson, S. G., & Joannopoulos, J. D. (2005). Slow-light, band-edge waveguides for tunable time delays. Optics Express, 13(18), 7145. doi:10.1364/opex.13.007145Garcia, J., Sanchis, P., Martinez, A., & Marti, J. (2008). 1D periodic structures for slow-wave induced non-linearity enhancement. Optics Express, 16(5), 3146. doi:10.1364/oe.16.003146Pérez-Millán, P., Torres-Peiró, S., Cruz, J. L., & Andrés, M. V. (2008). Fabrication of chirped fiber Bragg gratings by simple combination of stretching movements. Optical Fiber Technology, 14(1), 49-53. doi:10.1016/j.yofte.2007.07.00

Concatenated non-stationary dispersive scenarios on complex terrain under summer conditions

International audienceThe results and discussions presented in this paper arise from a statistically representative study of the physical processes associated with the multimodal distribution of pollutants aloft and around a 343-m-tall chimney under summer conditions in the Iberian Peninsula. The indetermination of a transversal plume to the preferred transport direction during transitional periods implies a small (or null) physical significance of the classical definition of horizontal standard deviation of the concentration distribution. By experimentation and modelling, this paper analyses the atmospheric dispersion of the SO2 emissions from a power plant on complex terrain, describing the main dispersion features as an ensemble of "stationary dispersive scenarios" and reformulating some "classical" dispersive concepts to deal with the systematically monitored summer dispersive scenarios in inland Spain

A study of dispersion in complex terrain under winter conditions using high-resolution mesoscale and Lagrangian particle models

A mesoscale model (MM5), a dispersive Langrangian particle model (FLEXPART), and intensive meteorological and COrrelation SPECtrometer (COSPEC) measurements from a field campaign are used to examine the advection and turbulent diffusion patterns associated with interactions and forcings between topography, synoptic atmospheric flows and thermally-driven circulations. This study describes the atmospheric dispersion of emissions from a power plant with a 343-m tall chimney, situated on very complex terrain in the North-East of Spain, under winter conditions. During the field campaign, the plume was transported with low transversal dispersion and deformed essentially due to the effect of mechanical turbulence. The main surface impacts appeared at long distances from the emission source (more than 30 km). The results show that the coupled models (MM5 and FLEXPART) are able to predict the plume integral advection from the power plant on very complex terrain. Integral advection and turbulent dispersion are derived from the dispersive Lagrangian model output for three consecutive days so that a direct quantitative comparison has been made between the temporal evolution of the predicted three-dimensional dispersive conditions and the COSPEC measurements. Comparison between experimental and simulated transversal dispersion shows an index of agreement between 80% and 90%, within distance ranges from 6 to 33 km from the stack. Linked to the orographic features, the simulated plume impacts on the ground more than 30 km away from the stack, because of the lee waves simulated by MM5

Response Surface Method to Calculate Energy Savings Associated with Thermal Comfort Improvement in Buildings

In developed countries, a large part of the building stock in 2050 will consist of currently existing buildings. Consequently, in order to achieve the objectives in terms of energy efficiency in the building sector we must consider not only new infrastructures but also the old ones. A reduction in energy consumption for climate control of between 50 and 90% can be achieved by rehabilitation and the implementation of different energy efficiency measures. Currently, these measures to reduce energy consumption and associated CO2 emissions can be modelled using computer tools. However, high precision and detail of thermal behaviour models through simulations can mean a great computational cost for companies, which results in a blockage of servers and workers. In this paper, the Response Surface Methodology (RSM) is presented as an innovative methodology for the simplification of models for calculation of the energy savings associated with thermal comfort improvement in buildings. A single-family house model, located in three different climates, is presented as a case study in order to validate the proposed methodology. Different scenarios were simulated, addressing heating and cooling temperature set points and external wall insulation represented by the transmittance (U-value). Results obtained from energy simulation using Design Builder were contrasted against those estimated from the simplified model extracted from the RSM analysis. The results revealed a deviation lower than 3% when comparing both methods. Therefore, the simplified mathematical prediction models are demonstrated to be suitable for the study of the energy performance of buildings, saving computational time, costs and associated human resources. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Monitoring SO2 emission at the Soufriere Hills Volcano: implications for changes in erruptive conditions

FLWINinfo:eu-repo/semantics/publishe