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1.
Measuring the spatial variability of black carbon in Athens during wintertime
Georgios Grivas, Iasonas Stavroulas, Eleni Liakakou, Dimitris G. Kaskaoutis, Aikaterini Bougiatioti, D. Paraskevopoulou, Evangelos Gerasopoulos, Nikolaos Mihalopoulos, 2019, original scientific article

Abstract: A first assessment of the spatial variability of ambient black carbon (BC) concentrations in the Greater Area of Athens (GAA) was carried out during an intensive wintertime campaign, when ambient levels are exacerbated by increased biomass burning for residential heating. Short-term daytime BC measurements were conducted at 50 sites (traffic and urban/suburban/regional background) and on-road along 12 routes. Daytime measurements were adjusted based on BC concentrations continuously monitored at a reference site. Indicative nighttime BC ambient concentrations were also measured at several residences across the area. Daytime BC concentrations recorded an average of 2.3 μg m-3 with considerable between-site variability. Concentrations at traffic sites were significantly higher (43% on average), compared with the rest of the sites. Varying levels were observed between background site subtypes, with concentrations at urban background sites (located near the center of Athens and the port of Piraeus) being 34% and 114% higher, on average, than at suburban and regional background sites, respectively. The traffic intensity at the nearest road and the population and built density in the surrounding area of sites were recognized as important factors controlling BC levels. On-road concentration measurements (5.4 μg m-3 on average) enabled the identification of hot-spots in the road network, with peak levels encountered along motorways (13.5 μg m-3 on average). Nighttime measurements demonstrated that wintertime BC pollution, enhanced by residential biomass burning for heating, affects the entire Athens basin. The reference site in central Athens was found to be representative of the temporal variability for daytime and nighttime BC concentrations at background locations.
Keywords: mobile measurements, microaethalometer, Athens, mapping, traffic, biomass burning
Published in RUNG: 10.05.2024; Views: 705; Downloads: 8
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2.
Integrating in situ measurements and city scale modelling to assess the COVID–19 lockdown effects on emissions and air quality in Athens, Greece
Georgios Grivas, Eleni Athanasopoulou, Anastasia Kakouri, Jennifer Bailey, Eleni Liakakou, Iasonas Stavroulas, Panayiotis Kalkavouras, Aikaterini Bougiatioti, Dimitris G. Kaskaoutis, Michel Ramonet, 2020, original scientific article

Abstract: The lockdown measures implemented worldwide to slow the spread of the COVID–19 pandemic have allowed for a unique real-world experiment, regarding the impacts of drastic emission cutbacks on urban air quality. In this study we assess the effects of a 7-week (23 March–10 May 2020) lockdown in the Greater Area of Athens, coupling in situ observations with estimations from a meteorology-atmospheric chemistry model. Measurements in central Athens during the lockdown were compared with levels during the pre- and post-lockdown 3-week periods and with respective levels in the four previous years. We examined regulatory pollutants as well as CO2, black carbon (BC) and source-specific BC components. Models were run for pre-lockdown and lockdown periods, under baseline and reduced-emissions scenarios. The in-situ results indicate mean concentration reductions of 30–35% for traffic-related pollutants in Athens (NO2, CO, BC from fossil fuel combustion), compared to the pre-lockdown period. A large reduction (53%) was observed also for the urban CO2 enhancement while the reduction for PM2.5 was subtler (18%). Significant reductions were also observed when comparing the 2020 lockdown period with past years. However, levels rebounded immediately following the lift of the general lockdown. The decrease in measured NO2 concentrations was reproduced by the implementation of the city scale model, under a realistic reduced-emissions scenario for the lockdown period, anchored at a 46% decline of road transport activity. The model permitted the assessment of air quality improvements on a spatial scale, indicating that NO2 mean concentration reductions in areas of the Athens basin reached up to 50%. The findings suggest a potential for local traffic management strategies to reduce ambient exposure and to minimize exceedances of air quality standards for primary pollutants.
Keywords: pandemic, urban air pollution, traffic, chemical transport model, TAPM, mapping
Published in RUNG: 10.05.2024; Views: 978; Downloads: 4
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3.
WEAK CLOSURE OPERATIONS WITH SPECIAL TYPES IN LOWER BCK-SEMILATTICES
Hashem Bordbar, Young Bae Jun, 2017, original scientific article

Abstract: The notions of (strong) quasi prime mapping on the set of all ideals, t- type weak closure operation, and tender (resp., naive, sheer, feeble tender) weak closure operation are introduced, and their relations and properties are investigated. Conditions for a weak closure operation to be of t-type are provided. Given a weak closure operation, conditions for the new weak closure operation to be of t-type and to be a naive (sheer, feeble tender) weak closure operation are considered. We show that the new weak closure operation is the smallest tender weak closure operation containing the given weak closure operation.
Keywords: (strong) quasi prime mapping, t-type weak closure operation, naive (sheer, tender, feeble tender) weak closure operation.
Published in RUNG: 02.12.2019; Views: 3522; Downloads: 0
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4.
5.
Evaluation of policy and technical factors for the protection of karst aquifers
Katarina Kosič Ficco, 2019, doctoral dissertation

Abstract: Karst aquifer protection remains inchoate. National and international legally-binding mechanisms rarely consider implementation of karst-specific measures for their evaluation and protection. Although developing suitable protection measures for karst aquifers is challenging because their variable character hampers implementation of generalized methods, it is not impossible. As presented in this dissertation, consideration of scientific aspects and inclusion of karst-specific evaluation methods is of great importance. However, the additional inclusion of socio-political aspects is also crucial for advances in karst aquifer protection. Analyses of current European Union and United States of America policies performed in this study have shown that they can provide valuable input regarding the topic. It is also clear that accounting for the interests of affected entities, such as policy-makers, stakeholders and the public, is critical. Satisfying their needs, and assuring their understanding of karst aquifers, can ease and improve implementations of adopted measures. By recognizing these aspects, an interdisciplinary framework for karst aquifer protection was developed, and is presented in this study. The so-called K-framework, developed as a checklist, assures implementation of necessary steps for comprehensive karst aquifer evaluation and management. It further defines how each entity can contribute to the process by providing their knowledge, and allocates responsibilities of each sphere. An important attribute of the proposed framework is that it can be used on varying karst terrains and for various impacts that might threaten karst aquifers. Additionally, it is cost- and time-efficient, while still considering important aspects of karst and insuring the inclusion of important affected parties.
Keywords: aquifer, groundwater, karst, protection, environmental legislation, confined animal feeding operation, vulnerability mapping
Published in RUNG: 17.06.2019; Views: 4488; Downloads: 147
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6.
Drifting through Cityscapes : Mapping the Local
Szabolcz Kisspal, Allan Siegel, Eszter Lazar, Olivera Batajić Sretenović, Danica Bojić, 2018, professional monograph

Keywords: local, city, urban, mapping, intermedia
Published in RUNG: 06.06.2018; Views: 4278; Downloads: 37
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