Browsing by Author "Predyov I."

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    AIR QUALITY ASSESSMENT BASED ON LIMITED QUANTITY OF MEASURED DATA
    (2022-01-01) Ilieva N.; Predyov I.; Sokolovski E.
    This study is dedicated to the air quality monitoring regarding the allowed exceedances of PM10 daily average concentration limit. It is directed to air quality assessment in the boundary layer of the atmosphere in cases when a limited quantity of measured data is available. Such cases are typical for small and medium-sized settlements. An appropriate test whether the daily average PM10 concentration is not higher than the limit value 50 μg m−3 for at least 90.4 % of the days in the year has been proposed. It can be applied for analysis of data supplied by mobile automatic monitoring stations or indicative measurements using equivalent methods.
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    Sensors applicability for PM2.5 and PM10 air concentration measurements
    (2018-01-01) Ilieva N.; Nikolova Y.; Predyov I.; Kozarev N.
    Comparisons of Private Stations (PS) measurements with Automatic Monitoring Stations (AMS) included in the National Environmental Monitoring System of the Ministry of Environment and Waters in Bulgaria has been made. The chosen PS (a total of four) are located close to AMS. In order to check whether the PS data are reliable and could be used for air quality monitoring, a statistical analysis of the data from the PS and the AMS was performed. The concentrations measured by two methods are quite different, but a good correlation between them has been established. In order to improve the PS measurement accuracy models for correction of the PM10 and PM2.5 concentrations measured using sensors were derived. They are characterized with good accuracy but are only valid for the warm part of the year. It is necessary to derive another set of coefficients for the cold half of the year. Without correction, the PS measurement error is large and their records may be misleading.