14 research outputs found

    Source apportionment of fine PM and sub-micron particle number concentrations at a regional background site in the western Mediterranean: a 2.5 year study

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    The chemical composition and sources of ambient fine particulate matter (PM₁) over a period of 2.5 years for a regional background site in the western Mediterranean are presented in this work. Furthermore, sub-micron particle number concentrations and the sources of these particles are also presented. The mean PM₁ concentration for the measurement period was 8.9 μgm¯³, with organic matter (OM) and sulphate comprising most of the mass (3.2 and 1.5 μgm¯³ respectively). Six sources were identified in PM₁ by Positive Matrix Factorisation (PMF): secondary organic aerosol, secondary nitrate, industrial, traffic + biomass burning, fuel oil combustion and secondary sulphate. Typically anthropogenic sources displayed elevated concentrations during the week with reductions at weekends. Nitrate levels were elevated in winter and negligible in summer, whereas secondary sulphate levels underwent a contrasting seasonal evolution with highest concentrations in summer, similar to the fuel oil combustion source. The SOA source was influenced by episodes of sustained pollution as a result of anticyclonic conditions occurring during winter, giving rise to thermal inversions and the accumulation of pollutants in the mixing layer. Increased levels in summer were owing to higher biogenic emissions and regional recirculation of air masses. The industrial source decreased in August due to decreased emissions during the vacation period. Increases in the traffic + biomass burning source were recorded in January, April and October, which were attributed to the occurrence of the aforementioned pollution episodes and local biomass burning emission sources, which include agriculture and domestic heating systems. Average particle number concentrations (N₉_₈₂₅ nm) from 5/11/2010 to 01/06/2011 and from 15/10/2011 to 18/12/2011 reached 3097 cm¯³. Five emission sources of particle of sub-micron particles were determined by Principal Component Analysis (PCA); industrial + traffic + biomass burning, new particle formation + growth, secondary sulphate + fuel oil combustion, crustal material and secondary nitrate. The new particle formation + growth source dominated the particle number concentration (56% of total particle number concentration), especially for particles 100 nm) and thus did not influence the particle number concentration significantly

    Trends of particulate matter (PM₂.₅) and chemical composition at a regional background site in the Western Mediterranean over the last nine years (2002-2010)

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    The time variability and long term trends of PM₂.₅ (particulate matter of diameter <2.5 μm) at various regional background (RB) sites across Europe are studied and interpreted in this work. Data on mean annual levels of PM₂.₅ measured at Montseny (MSY, North East Spain) and various RB sites in Spain and Europe are evaluated and compared, and subsequently analysed for statistically significant trends. The MSY site registered higher average PM₂.₅ levels than those measured at a selection of other RB sites across Spain, Portugal, Germany and Scandinavia by percentage compared to the mean of all the stations in these countries, but lower than those measured in Switzerland, Italy and Austria. Reductions in PM₂.₅ were observed across all stations in Spain and Europe to varying degrees (7-49%). MSY underwent a statistically significant reduction since measurements began, indicating a year-on-year gradual decrease (−3.7 μgm¯³, calculated from the final year of data compared to the mean). Similar trends were observed in other RB sites across Spain (−1.9 μgm¯³). Reductions recorded in PM₂.₅ across Europe were varied, with many experiencing gradual, year-on-year decreases (−1.8 μgm¯³). These reductions have been attributed to various causes: the introduction and implementation of pollution abatement strategies in EU member states, the effect of the current economic crisis on emissions of PM₂.₅ and the influence of meteorology observed during the winters of 2009 and 2010. In addition, the North Atlantic Oscillation (NAO), a large scale meteorological phenomenon most prevalent during winter, was observed to influence the frequency of Saharan dust intrusions across the Iberian Peninsula. Chemical composition of PM₂.₅ at MSY is characterised by high levels of organic matter (OM) and sulphate, followed by crustal material, nitrate and ammonia. Sea Spray and elemental carbon (EC) comprised a minor part of the total PM₂.₅ mass. Statistical trend analysis was performed on the various chemical components of PM₂.₅ recorded at MSY to determine which components were accountable for the decrease in PM₂.₅ concentration. It is shown that OM underwent the largest decrease over the time period with a statistically significant trend (−1.3 μgm¯³ compared to the mean), followed by sulphate (−0.8 μgm¯³), ammonium (−0.5 μgm¯³) and nitrate (−0.4 μgm¯³). Conversely, sea spray, EC and crustal a material reductions were found to be negligible

    DNA delivery via cationic solid lipid nanoparticles (SLNs)

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    In recent years the use of solid lipid nanoparticles (SLNs) as transport systems for the delivery of drugs and biomolecules has become particularly important. The use of cationic SLNs developed by the technique of microemulsion, which are complexed with DNA in order to study their application as non-viral vectors in gene therapy, is reported. The nanoparticles are characterized by scanning electron microscopy and transmission electron microscopy (SEM and TEM), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). Furthermore, the process of lyophilization of the samples and their stability was studied. The nanoparticles obtained presented a particle size of 340 nm with a positive surface charge of 44 mV and the capability of forming lipoplexes with DNA plasmids was stated

    Emociones y psicoterapia: caminos e intersecciones

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    En este libro, dirigido a profesionales y estudiantes del campo de la psicología, se reúnen diversas investigaciones centradas en las emociones desde las dimensiones psicológica, social y cultural y despliega diversas formas de trabajo, regulación, expresión y reconfiguración emocional en aras de un mayor bienestar psicológico. Como parte del alivio psicológico, las emociones son condición que favorece el trabajo psicoterapéutico para generar condiciones de bienestar en las personas y afrontar lo emocional desde la psicoterapia, remite al tema de la pertenencia y la identidad; por tanto, la comprensión del vínculo inquebrantable entre el cuerpo y las emociones resulta fundamental para su gestión.ITESO. A.C

    Elaboración de vídeos explicativos de las prácticas curriculares del alumnado del Máster de Estudios de Género

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    El proyecto está basado en la elaboración de vídeos explicativos por parte de los responsables de los centros de prácticas con los que tenemos convenios con objeto de explicar el funcionamiento del centro, el objetivo de las prácticas a desarrollar y las funciones del alumnado

    Variability of atmospheric aerosols at urban, regional and continental backgrounds in the western mediterranean basin

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    El estudio de los niveles y composición del material particulado atmosférico (PM) medido simultáneamente en diferentes ambientes a escala regional se llevó a cabo en la cuenca del Mediterráneo Occidental con el fin de entender las fuentes y patrones de transformación y transporte de aerosoles en esta zona. Para esto, la medida de niveles y caracterización química de PM10, PM2.5 y PM1 se llevó a cabo en tres estaciones de monitoreo: Montsec (MSC, fondo continental, 1570 msnm), Montseny (MSY, fondo regional, 720 msnm) y Barcelona (BCN, fondo urbano, 68 msnm). Además, se midieron niveles de número de partículas (N) y carbono negro (BC) en BCN. Durante el invierno, la frecuente estabilidad atmosférica induce el estancamiento de masas de aire produciendo importantes episodios de contaminación en BCN. Sin embargo, MSY y, más frecuentemente MSC, quedan aislados de la contaminación regional. En determinados escenarios, el desarrollo de la capa límite y las brisas resultan en el transporte de masas de aire contaminadas a zonas rurales, aumentando notablemente los niveles de PM en función de la altitud y la distancia a las zonas fuente. Durante el verano, la circulación de brisas favorece la dispersión, mezcla y envejecimiento de contaminantes a escala regional y la reducción de las diferencias entre BCN, MSY y MSC. Se midieron niveles similares de algunos componentes (materia orgánica, sulfato) a escala regional. Los niveles de materia mineral aumentan en verano por una resuspensión favorecida y una mayor frecuencia de intrusiones africanas, más significativamente en el MSC, dado su impacto en altura. La mayor contribución al PM10 en BCN se debe principalmente al tráfico (50% del PM10), resultante de las emisiones del tráfico primarias, nitrato y aerosoles secundarios envejecidos. La materia mineral se origina por resuspensión del polvo de carretera por vehículos pero también resuspensión por viento y obras. La contribución regional en BCN (25%) es principalmente materia mineral, nitrato y sulfato amónico. La variabilidad horaria de los diferentes parámetros de medida de aerosoles en BCN (N, BC, PM10, PM2.5 y PM1) está muy marcada por emisiones de tráfico y meteorología (especialmente brisas). Sin embargo, algunos parámetros no se rigen solamente por emisiones directas del tráfico, como PM2.5-10 (resuspensión) y N (emisiones de partículas ultrafinas y procesos de nucleación fotoquímica). La influencia de las emisiones del tráfico en los niveles de partículas finas en BCN se refleja en los niveles anuales de PM1, que aumentan de 2003 a 2007 relacionados con un aumento progresivo del tráfico y la flota diesel en BCN. Sin embargo se observó una tendencia decreciente en las fracciones gruesas en BCN y MSY, que se atribuye a la meteorología y a cambios en emisiones industriales. El estudio simultáneo de diferentes parámetros ha mostrado que el control de PM1 (modos de nucleación y acumulación) y/o BC (procesos de combustión), y PM10, (combustión y aerosoles generados mecánicamente) puede ser una estrategia mejor que la combinación de PM2.5 y PM10 como estándares de medida de calidad del aire. La medida en paralelo de aerosoles en fondos urbano, regional y continental ha sido una estrategia útil para entender la fenomenología de aerosoles en la cuenca del Mediterráneo Occidental. Las emisiones urbanas e industriales tienen un impacto considerable en los niveles y composición de PM en zonas rurales situadas a diferentes alturas, tanto en verano, con una importante recirculación y mezcla de masas de aire a escala regional, como en invierno, con transporte de contaminantes activado por brisas. El gran impacto de la contaminación urbana a escala regional demuestra la importancia de aplicar estrategias de reducción de emisiones de tráfico urbano, a fin de mejorar la calidad del aire no sólo a nivel local, sino también a escala regional.A detailed study of atmospheric particulate matter (PM) levels and composition measured simultaneously in different environments at a regional scale was performed in the Western Mediterranean Basin in order to understand the sources, transformation and transport of tropospheric aerosols in this area. In this direction, the monitoring of PM10, PM2.5 and PM1 levels and chemical characterization was carried out at three monitoring stations: Montsec (MSC, continental background, 1570 m.a.s.l.), Montseny (MSY, regional background, 720 m.a.s.l.) and Barcelona (BCN, urban background, 68 m.a.s.l.). In addition, number concentration (N) and black carbon (BC) levels were monitored at BCN. During winter, the frequent anticyclonic atmospheric stability induces the stagnation of air masses that produce important pollution episodes at BCN. However, atmospheric decoupling leaves MSY and, more frequently MSC, isolated from regional pollution during several days. In specific scenarios, the growth of the boundary layer and development of mountain breezes, activated by solar radiation, result in the transport of polluted air masses accumulated in the valley to the rural sites, increasing markedly PM levels at a different rate depending on the altitude and distance to the source areas. During summer, intense breeze circulations and atmospheric mixing favour the dispersion, recirculation and ageing of pollutants at a regional scale, reducing the differences between the urban and the rural sites. Similar levels of some components (organic matter or sulphate) were measured at a regional scale. Mineral matter levels increase during the summer, because of a favoured dust resuspension and higher frequency of African dust outbreaks, more significantly at MSC given the impact of African dust at higher altitudes. The major contribution to PM10 in BCN was mainly related to road traffic (50% of PM10), resulting from primary traffic emissions, secondary nitrate and aged secondary aerosols. Anthropogenic dust may originate from road dust resuspension by vehicles, but also wind resuspension and construction/demolition works. The regional contribution at the urban site (25%) was mainly mineral dust, ammonium sulphate and nitrate. The hourly variability of aerosol measurement parameters (N, BC, PM10, PM2.5 and PM1) at BCN is very influenced by road traffic emissions and meteorology (especially breezes). However, some parameters are not only governed by traffic exhaust emissions, as PM2.5-10 (dust resuspension processes) and N (direct ultrafine particle emissions but also photochemical nucleation processes). The influence of road traffic emissions on the levels of fine PM at BCN is reflected in PM1 mean annual levels, showing an increasing trend from 2003 to 2007 and correlation with the progressive rise in road traffic flow and diesel fleet in BCN. However a decreasing trend was observed for the coarser fractions at BCN and MSY, attributed to meteorology and changes in industrial emissions. The simultaneous study of different parameters showed that the monitoring of PM1 (nucleation and accumulation modes) and/or BC (combustion processes), and PM10 (combustion and mechanically-generated aerosols) may be a better strategy than the combination of PM2.5 and PM10 measurements as air quality standards. The parallel monitoring of aerosols at urban, regional and continental backgrounds was a useful strategy in order to understand the phenomenology of aerosols in the WMB. Urban and industrial emissions have a considerable impact in PM levels and composition in rural areas at different altitudes, both in summer, with important atmospheric recirculation and mixing of air masses at a regional scale, and winter, with breeze-activated transport of stagnated urban pollutants. The high contribution of urban emissions and the transport of air masses at a regional scale demonstrate the importance of applying emission abatement strategies for urban road traffic, in order to improve air quality not only at a local, but also at a regional scale

    Source apportionment of fine PM and sub-micron particle number concentrations at a regional background site in the western Mediterranean: a 2.5 year study

    No full text
    The chemical composition and sources of ambient fine particulate matter (PM₁) over a period of 2.5 years for a regional background site in the western Mediterranean are presented in this work. Furthermore, sub-micron particle number concentrations and the sources of these particles are also presented. The mean PM₁ concentration for the measurement period was 8.9 μgm¯³, with organic matter (OM) and sulphate comprising most of the mass (3.2 and 1.5 μgm¯³ respectively). Six sources were identified in PM₁ by Positive Matrix Factorisation (PMF): secondary organic aerosol, secondary nitrate, industrial, traffic + biomass burning, fuel oil combustion and secondary sulphate. Typically anthropogenic sources displayed elevated concentrations during the week with reductions at weekends. Nitrate levels were elevated in winter and negligible in summer, whereas secondary sulphate levels underwent a contrasting seasonal evolution with highest concentrations in summer, similar to the fuel oil combustion source. The SOA source was influenced by episodes of sustained pollution as a result of anticyclonic conditions occurring during winter, giving rise to thermal inversions and the accumulation of pollutants in the mixing layer. Increased levels in summer were owing to higher biogenic emissions and regional recirculation of air masses. The industrial source decreased in August due to decreased emissions during the vacation period. Increases in the traffic + biomass burning source were recorded in January, April and October, which were attributed to the occurrence of the aforementioned pollution episodes and local biomass burning emission sources, which include agriculture and domestic heating systems. Average particle number concentrations (N₉_₈₂₅ nm) from 5/11/2010 to 01/06/2011 and from 15/10/2011 to 18/12/2011 reached 3097 cm¯³. Five emission sources of particle of sub-micron particles were determined by Principal Component Analysis (PCA); industrial + traffic + biomass burning, new particle formation + growth, secondary sulphate + fuel oil combustion, crustal material and secondary nitrate. The new particle formation + growth source dominated the particle number concentration (56% of total particle number concentration), especially for particles 100 nm) and thus did not influence the particle number concentration significantly

    Trends of particulate matter (PM₂.₅) and chemical composition at a regional background site in the Western Mediterranean over the last nine years (2002-2010)

    No full text
    The time variability and long term trends of PM₂.₅ (particulate matter of diameter <2.5 μm) at various regional background (RB) sites across Europe are studied and interpreted in this work. Data on mean annual levels of PM₂.₅ measured at Montseny (MSY, North East Spain) and various RB sites in Spain and Europe are evaluated and compared, and subsequently analysed for statistically significant trends. The MSY site registered higher average PM₂.₅ levels than those measured at a selection of other RB sites across Spain, Portugal, Germany and Scandinavia by percentage compared to the mean of all the stations in these countries, but lower than those measured in Switzerland, Italy and Austria. Reductions in PM₂.₅ were observed across all stations in Spain and Europe to varying degrees (7-49%). MSY underwent a statistically significant reduction since measurements began, indicating a year-on-year gradual decrease (−3.7 μgm¯³, calculated from the final year of data compared to the mean). Similar trends were observed in other RB sites across Spain (−1.9 μgm¯³). Reductions recorded in PM₂.₅ across Europe were varied, with many experiencing gradual, year-on-year decreases (−1.8 μgm¯³). These reductions have been attributed to various causes: the introduction and implementation of pollution abatement strategies in EU member states, the effect of the current economic crisis on emissions of PM₂.₅ and the influence of meteorology observed during the winters of 2009 and 2010. In addition, the North Atlantic Oscillation (NAO), a large scale meteorological phenomenon most prevalent during winter, was observed to influence the frequency of Saharan dust intrusions across the Iberian Peninsula. Chemical composition of PM₂.₅ at MSY is characterised by high levels of organic matter (OM) and sulphate, followed by crustal material, nitrate and ammonia. Sea Spray and elemental carbon (EC) comprised a minor part of the total PM₂.₅ mass. Statistical trend analysis was performed on the various chemical components of PM₂.₅ recorded at MSY to determine which components were accountable for the decrease in PM₂.₅ concentration. It is shown that OM underwent the largest decrease over the time period with a statistically significant trend (−1.3 μgm¯³ compared to the mean), followed by sulphate (−0.8 μgm¯³), ammonium (−0.5 μgm¯³) and nitrate (−0.4 μgm¯³). Conversely, sea spray, EC and crustal a material reductions were found to be negligible
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