National Repository of Grey Literature 86 records found  beginprevious42 - 51nextend  jump to record: Search took 0.01 seconds. 
Response of aerosol concentrations to the daily atmospheric boundary layer variability at the national atmospheric observatory Košetice
Holubová Šmejkalová, Adéla ; Zíková, Naděžda ; Ždímal, Vladimír ; Komínková, Kateřina ; Holoubek, Ivan
The atmospheric boundary layer (ABL) is the part of the troposphere directly influenced by the properties of the Earth’s surface. The ABL thickness reaches from hundreds of meters to a few kilometres. The daily cycle of the ABL height is primarily result of interaction between incoming solar radiation and Earth’s surface heat fluxes because a turbulent motion is dominant in this layer. Air pollutants are generally emitted from surface and their measured concentrations are also influenced by dilution of the atmosphere, or ABL thickness. This study is focused on the linkage between the diurnal ABL height evolution and aerosol particle number concentrations.
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Plný tet: SKMBT_C22018110212451 - Download fulltextPDF
Changes in Sub-micron Number Size Distributions at Czech Rural and Urban Background Stations in the Last Ten Years.
Zíková, Naděžda ; Ondráček, Jakub ; Wagner, Zdeněk ; Ždímal, Vladimír
In this work, not only total concentrations are evaluated, but also particle number size distributions (PNSD) are compared in the last decade at the two stations, and possible explanations for the change in concentrations and PNSD changes are looked for. Additionally, also the change in the frequency and strength of the NPF events is evaluated.\n
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Comparison of Atmospheric Aerosol Volatility at a Rural Site in Central Europe.
Kubelová, Lucie ; Vodička, Petr ; Makeš, Otakar ; Zíková, Naděžda ; Ondráček, Jakub ; Schwarz, Jaroslav ; Ždímal, Vladimír
Volatility is an important characteristic of atmospheric aerosols as it affects their origin, lifetime and removal. Accurate description of aerosol volatilities is important for models calculating condensation of semi-volatile species and it also enables better identification of aerosol sources (Wu et al., 2009). However, our understanding of volatilities of organic atmospheric aerosols and the related processes is still rather poor (Han et al., 2016.
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Plný tet: SKMBT_C22017103113060 - Download fulltextPDF
Transformation of Aerosol Particles during Transport from Outdoor to Indoor Environment.
Ondráček, Jakub ; Talbot, Nicholas ; Kubelová, Lucie ; Makeš, Otakar ; Cusack, Michael ; Schwarz, Jaroslav ; Vodička, Petr ; Zíková, Naděžda ; Ždímal, Vladimír
One summer (2014) and one winter (2015) campaign (both lasting three weeks) were conducted to assess the indoor/outdoor physical and chemical properties of aerosol in an unoccupied apartment. The main purpose of these campaigns was to observe the changes in aerosol particles before and after their transport from outdoors to indoors. The most important parameter – the I/O ratio was obtained from indoor/outdoor measurements of aerosol number size distribution as well as chemical composition. The I/O ratios can reveal the changes in particle size and physicochemical characteristics indoors in relation to the size distribution and chemical composition outdoors, and physical parameters such as wind speed, temperature, and RH.
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New low-cost polutant sensor evaluation
Sinkulová, Michaela ; Zíková, Naděžda (advisor) ; Hovorka, Jan (referee)
This bachelor thesis deals with the introduction and subsequent comparison of low-cost sensors measuring air pollutants, which were used in the Citi-sense project in Ostrava. The results of the measurements carried out in the period from 1st June 2015 to 7th September 2015, are compared with reference data measured by the Czech hydrometeorological institute during the same period. The data are analyzed to provide the basis for further research into low-cost devices monitoring air pollution. Basic parameters such as average values, correlation coefficient, slope of linear regression, reproducibility of results, RMSE, and weekly and daily cycle are calculated for all measured pollutants (O3, CO, NOx, NO2, NO, PM10). The results are graphically illustrated and commented. The thesis also discusses the concordance of concentrations measured by the sensors with the data from the reference instruments, and the use of these new sensors in air quality monitoring in the future. Key words: Low-cost sensors, pollutants, air pollution monitoring methods
Aerosol light scattering measurements
Novotná, Nikola ; Zíková, Naděžda (advisor) ; Klán, Miroslav (referee)
This master thesis analyses light scattering on atmospheric aerosols, which has been measured at Košetice observatory in Pelhřimov region since 2012. In the thesis, data are processed for period from 1. 1. 2014 to 31. 12. 2015 which provide representative values of scattering and backscattering light measurement. Angstroem exponent was calculated based on which data corrections were performed. Data were processed using hour steps and compared with meteorological and emissions concentrations data. Correlations were calculated and regressions models estimated in order to verify correctness of measurement and to explore impact of meteorological conditions and emissions concentrations PM2,5 and PM10 on scattering coefficients. Performed analyses imply, that light scattering is higher for higher concentrations of PM2,5 and PM10 and for higher relative air humidity and lower for higher outdoor temperature, total precipitations, and wind speed. In addition, it was showed that light scattering is influenced by wind direction, which determines compositions of aerosols in the sample. Key words: atmospheric aerosol, light scattering, time series evaluation
Aerosol light extinction measurements
Múčková, Nikola ; Zíková, Naděžda (advisor) ; Holubová Šmejkalová, Adéla (referee)
This bachelor thesis deals with the basic processing of measured light extinction data, which was measured at seven wavelengths using the aethalometer (AE-31, Magee). Since 2012, the device has been located at the Košetice meteorological station in the Czech Republic, where the measurement has been ongoing and is currently continuing. The measured data from 2013 to 2015 were processed to provide a basis for further research in meteorology and climatology. Basic parameters such as extinction coefficient and other derived characteristics (Angstroem absorption coefficient, Delta-C) are calculated. From the final data the total average values and time dependencies are determined as daily, weekly and yearly cycles. All dependencies are graphically visualized and commented on. During the data processing, it was also found that during period 2013 - 2015 there was a decrease in the average of the concentration of black carbon and that it was the highest in the winter months. Keywords: atmospheric aerosol, light extinction, time series evaluation
New low-cost polutant sensor evaluation
Sinkulová, Michaela ; Zíková, Naděžda (advisor) ; Hovorka, Jan (referee)
This bachelor thesis deals with the introduction and subsequent comparison of low-cost sensors measuring air pollutants, which were used in the Citi-sense project in Ostrava. The results of the measurements carried out in the period from 1st June 2015 to 7th September 2015, are compared with data measured by the Czech hydrometeorological Institute during the same period of time. The data are designed to provide the basis for further research into low-cost devices monitoring air pollution. Basic parameters such as average values, correlation coefficient, slope of linear regression, weekly and daily cycle are calculated. The results are graphically illustrated and commented. The thesis also discusses the concordance of individual concentrations and use of these new sensors in air quality monitoring in the future. Key words: Low-cost sensors, pollutants, air pollution monitoring methods
Pollen charakterisation in size segregated aerosol
Kolpakova, Anna ; Hovorka, Jan (advisor) ; Zíková, Naděžda (referee)
This bachelor thesis, in literature review, deals with bioaerosol issue, describes meaning of pollen, ways of pollen spreading and its influence on human health, summarize methods of pollen sampling from the air and common ways of pollen grains identification. In the experimental part, the use of the first stage of a High Volumetric Cascade Impactor (Hi-Vol) BGI-900 for bioaerosol sampling and subsequent SEM analysis was proved. Method of pollen separation from the impaction substrate, polyurethane foam, into homogeneous deposit on Nylon filter was optimized. Representative portion of the deposit was analyzed by SEM. There were taken 485 SEM pictures from 12 samples in 3 localities in the ČR. Pollen grains were identified in 295 SEM and determined into 9 genus and 4 families and grain deformities were quantified to be 24, 18, 50% for Prague, Brezno and Láz localities. Number of pollen increased with total aerosol mass in Prague locality only. Thre aleo identified insect secrction products borochomomes in the samples. Key words: pollen, pollen grain, bioaerosol, cascade impactor, SEM.
Microclimate in classrooms and lecture halls throughout the year and its impact on health and focus of students
Malinda, Martin ; Zíková, Naděžda (advisor) ; Mašková, Ludmila (referee)
There is a growing evidence that thermal comfort, light levels and carbon dioxide concentration can have significant impact on alertness and performance. We have documented microclimate (temperature, relative humidity, light intensity level and CO2 concentration) in 7 different lecture rooms throughout the year. We have not measured any extreme conditions but on significant amount of lectures the microclimate conditions were not optimal. Out of 68 measured lectures 2 had median temperature below 19 řC and 13 lectures over 24 řC, i.e. out of the recommended values. On the cold lectures, students were observed to wear jackets and on the hot ones students were frequently opening windows which also suggest that the thermal conditions were suboptimal.. CO2 concentrations were suboptimal mostly in winter, when 26 out of 39 lectures had median CO2 levels above 1000 ppm which is, according to ASHRAE (American Society of Heating Refrigerating and Air-conditioning Engineers), an indicator for inadequate ventilation. Median CO2 level for all lectures from both semesters was 1060 ppm. Even though window opening effectively lowers CO2 concentrations, we found it to be as mostly a reactive behavior. It is very likely that if it would be done proactively, especially CO2 levels could be kept significantly lower. Light...

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