National Repository of Grey Literature 112 records found  beginprevious36 - 45nextend  jump to record: Search took 0.00 seconds. 
Assessment of odour annoyance in Štětí
Mikšovská, Petra ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
This thesis solves the odour issue in the ambient air. Due to the rising of a standard of living, people are no longer tolerant to excessive odours in the environment. Subject of the research is a perception of odour by inhabitants of the town Štětí. Štětí belongs to areas facing odour annoyance of its inhabitants, where the main source is a paper mill Mondi Štětí a.s. The goal of this thesis is to find out if the inhabitants of the town percieve the odour annoyance coming from the paper mill as problematic and explore their opinion of the odour situation in the area with respect to a near past, wish to the future and frequency of annoyance. Next goal is to find out if there exist a relation between immission concentrations of odours typical for a paper mill industry (sulfane, TRS) and subjective assessment of odour intensity by enquired inhabitants, and also what effect have different factors affecting odour perception (age, sex, pregnancy, smoking, personal and family relationship to the paper mill and adaptation to odours) on this relation. Method chosen to get the answers is a repetitive questioning of the inhabitants. In years 2010-2011 there were 16 events on which were made personal interviews with the inhabitants of Štětí near the immission measuring stations in Štětí. Totally 538 people...
Atmospheric aerosol vertical distribution in boudary layer
Dočekalová, Veronika ; Hovorka, Jan (advisor) ; Jančík, Petr (referee)
Particulate matter (PM) air pollution is one of the most important topics in the field of environmental protection, and coal strip mining is a significant source of coarse atmospheric aerosol. In order to implement appropriate regulations to improve air quality, we need to identify the major sources of pollution. PM is usually measured in a ground-based manner and its dispersion is only modelled. Therefore, the objective of this study was to measure concentrations of coarse aerosol in the atmospheric boundary layer above the area of the coal strip mine through experimental airborne measurements and to estimate pollution contribution of mining to the surroundings. Measurements were carried out from November 11 to November 26, 2012, at Vršany coal mine, Czech Republic. An electrically powered airship was used with a specially designed gondola carrying aerosol monitors DustTrak DRX and P-Trak. Temperature and relative humidity data were also recorded. Repeated flights were performed at several heights above mine edge level. PM1-10 and GPS data were recorded every second. Average airship velocity ranged from 6 to 7 ms-1 . Flight measurements were also compared to ground-based measurements of PM10 and meteorological data. Weather during our measurements was characterised by low temperatures, high relative...
Estimating infiltration of quasi-ultrafine aerosol by the absorbance method: Air quality in schools
Stehlíková, Pavla ; Braniš, Martin (advisor) ; Hovorka, Jan (referee)
Estimating infiltration of quasi-ultrafine black carbon particles by an absorbance method: air quality in Pavla Stehlíková Abstract This diploma thesis focused on the estimating quasi-ultrafine particles amount in school gyms continue previous study researched air quality in schools. The size-segregated mass concentration of particulate matter was measured in three elementary school gyms in central part of Prague, on periphery of Prague and in a small settlement Černošice during twenty campaigns, from 2005 to 2009. The mass concentration of particulate matter were measured by 5-staged Sioutas impactor. For this thesis we have selected samples on filters with particle size <0,25µm. To evaluate carbonaceous particles amount we used reflectance. Reflectance was transformed into an absorption coefficient (m- 1 .10-5 ). The average levels of absorptions coeficients were higher outdoors (14,66 ± 8,93 m- 1 .10-5 ) than indoors (13,64 ± 8,08 m-1 .10-5 ). The correlations between absorption coeffitients outdoors and indoors were significant for all schools (Spearman's correlation coefficient at intervals 0,834-0,957, regression slope 0,759-1,007), suggesting a high outdoor-to-indoor penetration rate. The weak correlation between absorption coefficients and number of exercising pupils (correlation coefficient 0,059)...
PM10 hot-spot identification and characterisation in Prague 7 city district
Nechvátalová, Karolína ; Hovorka, Jan (advisor) ; Kozáková, Jana (referee)
Many cities suffer from poor air quality as they concentrate a large number of anthropogenic sources of air pollution, especially aerosol particles with an aerodynamic diameter of less than 10 m, PM10. Due to high urbanization, more than 50 % of the world population is exposed to urban PM10. Exposure to elevated PM10 can cause respiratory and cardiovascular diseases or premature deaths. Therefore, the Prague 7 city district concluded an agreement with the Laboratory for Air Quality Studies (Charles University, Faculty of Science) to perform detailed spatial and temporal PM10 concentrations survey on its territory. For this purpose, mobile measurements of PM10 were performed in Prague 7. The study area was divided into 6 smaller localities. One fixed route (3,4-4,5 km) was determined at each locality. In the period from December 2019 to May 2020, a total of 174 errands were performed during 10 days, regularly at 8:00, 12:00 and 17:00. The team members conducted prescribed walks with DustTrak and Garmin GPS devices, which detected every second the PM10 mass concentrations and the exact location for a purpose to synchronize the PM10 data with the detection site. Meteorological conditions were recorded by a professional meteorological station. During most of the observed days, PM10 concentrations in...
Atmospheric deposition of nitrogen - application of stable isotopes
Hanzlová, Barbora ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Human impact on particular parts of ecosystems has become a highly discussed topic. Due to different isotopic values of nitrogen, it is possible to evaluate the extent to which human influences the natural nitrogen cycle, using isotope measurements. Stable isotope measurement has been used in various scientific disciplines around the world. This thesis summarizes the findings about atmospheric deposition and the subsequent use of stable nitrogen isotopes. The objective of this work was to gather the information about the use of stable isotopes in the study of the atmospheric deposition and how to make better use of the information obtained from the measurements. Based on the literature review, it has been found that, unlike other countries, nitrate substances such as NH3 and HNO3 are not measured in the Czech Republic, which distorts the data on the nitrogen produced. The use of stable isotopes is a convenient method of measuring both not yet quantified substances as well as already measured substances contributing to atmospheric deposition. The stable isotope measurement method represents an improvement for the overall estimation of atmospheric deposition to provide more realistic values compared to the current approach. Key words: atmospheric deposition, nitrogen, stable isotopes
Dynamics of vertical and horizontal profiles of atmospheric aerosol in planetary boundary layer
Esterlová, Jana ; Hovorka, Jan (advisor) ; Jančík, Petr (referee)
The boundary layer of the atmosphere is a layer of air with thickness about 1 km above the ground. Open-cast mining is one of activities that polutes the air in this layer. It generates particulate matter (PM) mostly in size of aerodynamic diameter 1 - 10 µm - coarse patricles. The companies that does the mining pays for their emissions due to the law. However, these emissions are not experimentraly measured, they are calculated from given equation consisting of factors like the size of mining area, etc. Some papers have shown significantly higher concentrations of Coarse particles (or PM10) in surroundings of the mine. Other papers have found out that the origin of these high concentrations didn't come from the mining activities but is caused due to the activities at the place of measuring or nearby. There aren't many papers that measure the PM concentrations in the air in the mining area. This thesis shows the results of airship measurements in the air layers of the open-cast mine and above them. The experimentral site was brown coal mine Bílina in the North of The Czech Republic in important mining area. The measurements took place in December 2017. For measuring the number and mass concentrations was used APS - Aerodynamic Particle Sizes Spektrometr by TSI which sorts out the data into...
Charakterisation of fungal aerosol in size segregated aerosol
Shamratova, Kseniia ; Hovorka, Jan (advisor) ; Kozáková, Jana (referee)
This bachelor thesis deals with the issue of bioaerosol, properties of airborne fungal spores, describes their significance, concentration, methods of spreading and influence on human health. This work provides information about sampling and detection methods of bioaeerosol. Was proved the suitability of using of the first step of the high volume cascade impactor (Hi-Vol) BGI-900 to collect biaerosol samples for subsequent scanning electron microscope (SEM) analysis. Using the optimized method, bioaerosol samples were isolated from the polyurethane foam, which is the impact substrate of the impactor. Bioaerosol samples were taken from 3 locations in the Czech Republic: Prague, Březno, Láz. During the SEM analysis of 15 bioaerosol samples, 605 SEM images were taken, on 340 of them were identified fungal spores. The smallest number of spores were found in Prague. Approximately the same amount of fungal spores was found in Březno and Láz. Fungal spores were identified into 9 genus, 1 family, and 1 species. The percentage of deformed spores in Prague was 48%, in Březno 23%, in Láz 25%. The greatest variability of spores was at the Březno and Láz localities. The most common fungal genus was the Cladosporium genus. No positive or negative correlation was observed between the number of fungi and the...
Spatio-temporal PM2.5 variability in village during winter.
Štědrá, Karolína ; Hovorka, Jan (advisor) ; Bendl, Jan (referee)
This thesis evaluates the spatial variability of PM2.5 concentrations during two winter months in the small village Lbín close to Teplice at the turn of the year 2017/2018. The PM2.5 concentrations were monitored through a dedicated monitoring network using a total of eight DustTrak laser nephelometers (Model 8520). Six DustTraks were located directly in the village in the valley, one of them was located on the hill above the valley and the last one was located approximately in the half of the hill. Using a network measurements, we tried to determine that the household heatings are the main sources of air pollution in the village. The basic meteorological parameters - wind speed and direction, temperature and air humidity were monitored together with PM2.5 concentrations. It was observed statistically significant difference between the measuring stations, which points to the unevenly distribution of pollution sources. The particle concentrations typically reach peak values in the morning and in the evening. The maximum peak values were 2607 μg·m-3 in December and 4347 μg·m-3 in January. The lowest maximum values were 223 μg·m-3 and 177 μg·m-3 for devices located above the village. An important factor contributing to the current situation was wind speed. If the wind speed was higher than 1,29 m·s-1...

National Repository of Grey Literature : 112 records found   beginprevious36 - 45nextend  jump to record:
See also: similar author names
10 HOVORKA, Jan
4 HOVORKA, Jaroslav
9 Hovorka, Jakub
2 Hovorka, Jan,
4 Hovorka, Jaroslav
2 Hovorka, Josef
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