Number Concentrations and Modal Structure of Indoor/Outdoor Fine Particles in Four European Cities

Indoor/outdoor aerosol size distribution was measured in four European cities (Oslo-Norway, Prague-Czech Republic, Milan-Italy and Athens-Greece) during 2002 in order to examine the differences in the characteristics of the indoor/outdoor modal structure and to evaluate the effect of indoor sources to the aerosol size distributions. All the measurement sites were naturally ventilated and were occupied during the campaigns by permanent residents or for certain time periods by the technical staff responsible for the instrumentation. Outdoor particle number (PN) concentrations presented the higher values in Milan and Athens (median values 1.4 x 10(4) # cm(-3) and 2.9 x 10(4) # cm(-3) respectively) as a result of elevated outdoor emissions and led to correspondingly higher indoor values compared to Oslo and Prague. In absence of indoor activities, the indoor concentrations followed the fluctuations of the outdoor concentrations in all the measurement sites. Indoor activities (cooking, smoking, etc.) resulted in elevated indoor PN concentrations (maximum values ranging between 1.7 x 10(5) # cm(-3) and 3.2 x 10(5) # cm(-3)) and to I/O ratios higher than one. The I/O ratios were size dependant and for periods without indoor activities, they presented the lowest values for particles <50 nm (0.51 +/- 0.15) and the ratios increased with fine particle size (0.79 +/- 0.12 for particles between 100-200 nm). The analysis of the modal structure showed that the indoor aerosol size distribution characteristics differ from the outdoors under the effect of indoor sources. The percentage of unimodal size distributions increased during indoor emissions, compared to periods without indoor sources, along with the number concentration of Aitken mode particles, indicating emissions in specific size ranges according to the type of the indoor source.Peer reviewe

A Novel Role of Peripheral Corticotropin-Releasing Hormone (CRH) on Dermal Fibroblasts

Corticotropin-releasing hormone, or factor, (CRH or CRF) exerts important biological effects in multiple peripheral tissues via paracrine/autocrine actions. The aim of our study was to assess the effects of endogenous CRH in the biology of mouse and human skin fibroblasts, the primary cell type involved in wound healing. We show expression of CRH and its receptors in primary fibroblasts, and we demonstrate the functionality of fibroblast CRH receptors by induction of cAMP. Fibroblasts genetically deficient in Crh (Crh−/−) had higher proliferation and migration rates and compromised production of IL-6 and TGF-β1 compared to the wildtype (Crh+/+) cells. Human primary cultures of foreskin fibroblasts exposed to the CRF1 antagonist antalarmin recapitulated the findings in the Crh−/− cells, exhibiting altered proliferative and migratory behavior and suppressed production of IL-6. In conclusion, our findings show an important role of fibroblast-expressed CRH in the proliferation, migration, and cytokine production of these cells, processes associated with the skin response to injury. Our data suggest that the immunomodulatory effects of CRH may include an important, albeit not explored yet, role in epidermal tissue remodeling and regeneration and maintenance of tissue homeostasis

On the Potential of SDN Enabled Network Deployment in Tactical Environments

Part 3: Workshop on Defense Applications of AI – (DAAI 2021)International audienceModern critical operations and defence applications require highly demanding information and communication systems, making ad hoc networks, which are mainly used nowadays in tactical zones, to be difficult to manage. The evolution of the Software Defined Networking (SDN) technology has brought new perspectives to security and defence applications, making them more reliable, more stable, more secure and more portable. This research paper proposes an SDN topology for secure communications in a tactical environment, overcoming several challenges that a conventional network faces. Moreover, an Artificial Intelligence (AI) methodology, exclusively used in SDN environments is presented, providing Quality of Service (QoS) features to the network, based on which rerouting paths can be calculated. Finally, our routing methodology is illustrated using representative evaluation scenarios

Impact of indoor houshold activities on the size distribution of fine aerosol number concentration and case specific calculated inhaled dose

Μη διαθέσιμη περίληψηNot available summarizationΠαρουσιάστηκε στο: European Aerosol Conferenc

Heterogeneous nucleation on rough surfaces: implications to atmospheric aerosols

Summarization: The effect of the surface roughness of solid atmospheric aerosol particles on their heterogeneous nucleation capability has been examined using the concept of “self-affine” rough surfaces. The surface roughness has a great influence on the contact angle between the particle surface and the nucleating liquid droplets. Roughness enhances wetting and the rate of heterogeneous nucleation from the vapor to the liquid phase. The paper furthermore discusses the considerable influence of the surface roughness on the physico-chemical characteristics of atmospheric insoluble aerosol particles.Παρουσιάστηκε στο: Atmospheric Researc

Size distribution, composition and origin of the submicron aerosol in the marine boundary layer during the eastern Mediterranean "SUB-AERO" experiment

Summarization: A period of intensive physical and chemical aerosol characterisation measurements was held over 5 days during July 2000 as part of the European SUB-AERO experiment.. Concurrent measurements were performed at the Finokalia remote coastal site on the island of Crete (Greece) and onboard the R/V “Aegaeon” which cruised in south part of the Aegean Sea northwards of Crete. The objective of the study was to investigate the spatial and temporal variability of microphysical parameters of the submicron aerosol and their dependence on airmass origin and chemical composition. The results reflect the submicron aerosol properties during airmass transport from the north including Europe and the Balkans and are in line with other studies on the aerosol properties of polluted continental air entering the marine boundary layer (MBL). Concentrations of submicron particulate matter (PM) mass were relatively higher at sea (20 μg m−3) compared to the coastal site (16 μg m−3). Concentrations of both organic carbon and sulphate, being the major water soluble component, were also higher at sea than at land. The high concentrations of ammonium and those of the water soluble organics, such as oxalate, can be attributed to emissions from mainland forest fires. The submicron aerosol number size distribution was unimodal with mobility mean diameters (dg) ranging from 98 to 144 μm and standard deviations (σg) from 1.56 to 1.9. Aerosol number concentrations at Finokalia were at least 50% lower especially when R/V Aegaeon sampled polluted air, but the modal parameters of the size distribution were very similar (dg: 111–120, σg: 1.55–1.91). The surface MBL, under these conditions, was an aerosol rich environment where aerosol particles were transported both by the surface wind, advected from higher layers, chemically processed by interactions with gaseous precursors and physically altered by water vapour. The number to volume ratio for the submicrometer aerosol fraction reflected the effect of these mechanisms on the size distribution.Παρουσιάστηκε στο: Atmospheric Environmen

Modal Structure of the Fine Urban Aerosol in four European Cities

The size distribution of the sub micrometer aerosol number concentration in the urban Environment appears to display a statistically significant modal structure (Van Dingenen et al., 2004). This depends on a number of factors such as local atmospheric conditions, density and type of emissions. The development of certain "universal" aerosol number distribution patterns can contribute towards the assessment of human exposure to fine particulate matter or facilitate the characterization of certain emission sources and their impact on air quality. Here, preliminary results from the analysis of measured number size distributions are presented for four European cities.JRC.H.4-Transport and air qualit

Dynamics of Fine Particles and Photo-oxidants in the Eastern Mediterranean (SUB-AERO)

As part of the European project SUB-AERO, comprehensive aerosol and gaseous pollutant measurement campaigns were performed at the Finokalia station (July 2000 and January 2001) on the island of Crete (Greece) in combination with boat measurements in the eastern part of the Mediterranean area. The measurements were performed with the participation of nine European research institutions. The objective of the measurement campaigns was to evaluate and assess the spatial and temporal variability of photochemical pollutants and fine particles. The current overview paper presents the framework and main results of the measurements and modelling studies performed during the project. Extensive measurements of gaseous and atmospheric-aerosol physical, chemical and optical characteristics were performed during the measurement campaigns in conjunction with detailed chemical analyses of the aerosol species. Along with the experimental work mesoscale modelling, using a combination of the UAM-AERO air quality model together with the RAMS prognostic meteorological model, was used to reveal the dynamics of particulate matter and photo-oxidants. Furthermore, regional chemistry transport models were applied to determine the background and initial conditions for the mesoscale modelling. r 2005 Elsevier Ltd. All rights reserved.JRC.H.4-Transport and air qualit