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Surface ozone influence on native vegetation: results based on ozone visible symptoms and stomatal flux
Matoušková, Leona ; Hůnová, Iva (advisor) ; Albrechtová, Jana (referee) ; Hovorka, Jan (referee)
Regarding the vegetation, the most affected areas by high levels of surface ozone (O3) are the mountain ridges. Our study has been carried out in the Jizerske hory Mts. High O3 levels together with the convenient environmental conditions for stomatal conductance could be a threat for the health of recovering ecosystems in this area. The aims of this study was both to assess the influence of O3 on vegetation in the Czech mountains and to provide recommendations and outlooks for possible future using of relatively new methods (visible symptoms and stomatal O3 flux modelling) used for O3 impact assessment on native vegetation in the field; that means physiologically relevant methods for the determination of O3 influence. During 2006 and 2007, O3-like visible symptoms were assessed on the leaves of seven species at four sites. Symptoms on only two species (Fagus sylvatica L. and Rubus idaeus L.) have been determined as O3-induced. To our knowledge, it is the first study in the Czech Republic in which the O3-like symptoms on native plants have been verified by the Ozone Validation Centre for Central Europe. Our results based on O3-induced symptoms indicate that ambient O3 is likely to have a much lower impact than expected, considering the measured O3 concentrations (measured with passive samplers) and...
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Environmental tobacco smoke in bars and restaurants
Tesař, Tomáš ; Braniš, Martin (advisor) ; Hovorka, Jan (referee)
Tobacco smoking has been proved to be harmful to human health and is a known cause of many diseases. It has been shown that not only active smoking can cause health inconveniences - even an exposure to the environmental tobacco smoke (so called secondhand - SHS - or passive smoking) is a serious threat to human health, in some aspects nearly as severe as active smoking. Being aware of these risks, many countries have recently amended their policies which more or less restrict smoking in public places, especially workplaces and hospitality venues. In the Czech Republic, the smoke-free policy belongs to the less strict related to other countries, because it does not restrict smoking at all public places - restaurant and bar owners can choose whether their venue is smoke-free or not and their duty is only to label their venue both outside and inside. The law also enables the option of setting smoking and non-smoking spaces within the restaurant or bar. In a representative sample (over 100) of smoking and non-smoking sections of these restaurants and bars the concentrations of PM2.5, a marker of SHS concentrations, were measured with a photometer. The venues were divided into 3 groups according to the extent of separation of the sections. Parallel to the measurements, the gender composition and smoking...
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Concentrations of indoor submicrometer and supermicrometer particulate matter in a primary school in Prague
Štolcpartová, Jitka ; Braniš, Martin (advisor) ; Hovorka, Jan (referee)
Children are a susceptible group to environment pollution. The environment, in which they spend the most time, is the home, the second is the school. Therefore, the indoor environment of a school affects their health, wellbeing and even school results. The present work investigated concentrations of air pollutant, aerosol particles, in the specialized classrooms (computer lab, arts and biology/chemistry) in an elementary school, Prague. Direct reading instruments measuring mass concentration of four aerosol fractions and number concentration of submicrometer particles were used for measurement. Measurements were carried out for four weekdays in each month from November 2011 to July 2012. It was found that mass concentrations of submicrometer particles were dependent on outdoor concentrations, in contrast to supermicrometer particles which were affected mainly by physical activities of students and outdoor concentration had a minimal effect. Increased number concentrations of submicrometer particles were observed only during children presence, concentrations were probably induced by student activities during lessons. Seasons also influenced mass concentrations, when the highest indoor and outdoor concentrations were recorded in a spring/autumn season. Classroom location affected submicrometer...
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PAH bond to nanoparticles of atmospheric aerosol: substrate specifity.
Bendl, Jan ; Hovorka, Jan (advisor) ; Cajthaml, Tomáš (referee)
Polycyclic aromatic hydrocarbons (PAHs) are reviewed including their chemical and chemical- physical features, their impact on health and the environment. Different behaviour of PAHs is mentioned. The detailed instruction for the measurement using high-volume cascade impactor BGI 900 (Hi-Vol) is described. Cleaning, equilibration, weighting, protection against contamination of the substrates and technique of the measurement were introduced. The experiment was done: under the last teflon back-up filter the extra PUF substrate was placed, where after the air exposition the significant amounts of gaseous phase of phenanthrene, anthracene, fluoranthene, pyrene and benzo(a)anthracene were captured. The extent of the volatile PAHs capture correlated positively with the vapour pressure (ranging from 10-4 to 10-1 Pa.). The other measured PAHs (coronene, benzo(ghi)perylene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene and indeno(1,2,3-cd)pyrene) with vapour pressure from 10-5 to 10-10 Pa were not captured. The experiment found out that polyurethane (PUF) substrates captured in noticeable amount the volatile phase of PAHs and therefore the correction for the capture of gaseous phase in the particle size fractions of PAHs was calculated. The deduction for the...
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Role of aerosol in climate change
Švátora, Milan ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
Atmospheric aerosol is a suspension of liquid or solid particles or their mixture in the atmosphere. Tropospheric aerosols can get into the air from its natural sources or from anthropogenic sources. Release of carbon dioxide from burning fossil fuels and organic and elemental carbon from biomass burning are the major anthropogenic sources of aerosols. Primary aerosols have a direct source of emissions (dust from quarries or from land, sea salt particles in the waves, volcanic ash during volcanic eruptions). Secondary aerosols are formed by chemical reactions of substances in the atmosphere, which converts the gas particles - so- called conversion of gases to particles (formation of nitrates by oxidation of nitrogen oxides and sulfates from sulfur dioxide). Atmospheric aerosol is an important component of the atmosphere and contributes to significant atmospheric events, such as precipitation formation and precipation fall, radiation balance of Earth. Aerosols can affect the radiation balance of the Earth in two ways. First, through absorption and scattering of shortwave and long wave radiation - so-called direct effect. Or serve as condensation nuclei on which water is condenses. Aerosols can affect formation, quantity, length of existence and radiation properties of clouds - so-called indirect effect. In...
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Energy saving buildings
Raška, David ; Přibil, Rudolf (advisor) ; Hovorka, Jan (referee)
Práce se zabývá problematikou nízkoenergetických a pasivních domů, včetně předložení důvodů pro jejich výstavbu. Poukazuje na jejich vlastnosti a sledované parametry pro splnění požadovaných hodnot. Dále pojednává o nejdůležitějších podmínkách pro výběr polohy energeticky efektivních staveb a o doporučeném zónování místností dle světových stran v závislosti na slunečním záření. Uvádí možnosti složení konstrukčních částí a nejčastěji používané výtopné systémy pro energeticky efektivní stavby, které jsou svým provozem šetrnější k životnímu prostředí. Cílem je předložit ucelenou informaci o daném tématu tak, aby bylo možno vyvozovat závěry podporující praktické využití těchto staveb, a to především z hlediska potenciálu značných energetických úspor. Práce rovněž vypovídá o vývoji výstavby energeticky úsporných budov v České republice. Abstract: This work is concerned with questions of energy saving buildings, including introduction of reasons for their building-up. It refers about their characteristics and evaluated parameters for meeting it's requirements. Further it deals with the most important conditions for choosing of location for energy saving buildings and about recommended zoning of rooms according to cardinal points depending on solar radiation. Indicates the posibilities of composition...
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Trends of ambient ozone in the Northern hemisphere
Bučková, Nicole ; Hůnová, Iva (advisor) ; Hovorka, Jan (referee)
The development of ground-level ozone concentrations is currently hotly debated topic. Ozone itself is highly toxic and has strong oxidizing effects. Ozone has negative impact on human health, but also on vegetation. In addition ozone is one of the most important greenhouse gases causing the greenhouse effect. The Council of Europe decided to limit its increasing tendency by the release of Directive 2002/3/EC. Limits that are set in this Directive are binding for all Member States without exception and breach of these limits is enforceable by law. However as a result of increased anthropogenic activities, particularly increased consumption of fossil fuels and the development of industrialization, those limits are very often breached. Especially in summer when is solar radiation is most intense. This suggests that the highest ozone concentrations are in southern Europe. North Europe has problems with intercontinental transport of ozone. Concentration of ozone is dependent on many factors - the weather conditions, the geography but also the impact from human activity. This paper describes the development of ground-level ozone concentrations in various regions in Europe and North America. In writing this work, I come out mainly from foreign studies that address this topic. Keywords: ozone,...
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Resuspension chamber as a tool for determination of resuspendable fraction of soil and street dust
Civiš, Martin ; Hovorka, Jan (advisor) ; Ždímal, Vladimír (referee) ; Střižík, Michal (referee)
A purpose-built cylindrical resuspension chamber (V=0.437 m3 , S=0.35 m2 , S/V=8.38) was used for the dispersion of samples of soil and various kinds of dust. The samples were studied from the point of view of the number and mass distribution of aerosol particles which could affect the concentration of atmospheric aerosol. The samples were taken from lignite, power plant flue ash and from overburden soil in the North Bohemian surface mine Nastup. The individual samples were pneumatically dispersed inside the chamber under defined temperature-humidity conditions (20řC and relative humidity (RH) 50 %). An APS (Aerodynamic Particle Sizer) processing provided us with average size distributions of particle mass and number. Lignite and flue ash probably have the greatest potential impact on the concentration of atmospheric aerosol in the studied locality. The amount of the resuspended mass of the samples varied between 0.001 % (overburden soil) and 0.32 % (mine road). The lignite and flue ash samples were then analyzed by gravimetric methods using the HI (Harvard Impactor) and the SCI (Sioutas Cascade Impactor). The flue ash contained higher amounts of fine particles than the lignite. Subsequent chemical analysis by electron microscope of the filters with deposits of power plant flue ash showed that the PM2.5...
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Family in modern American drama
Hovorka, Jan ; Wallace, Clare (advisor) ; Ulmanová, Hana (referee)
This work analyses the American family in context of society and its demands. It focuses on the cannonical works of the Modern American drama, namely plays of Tennessee Williams, Arthur Miller, Edward Albee, Sam Shepard and David Mamet. The playwrights are analysed in two distinctive groups according to similar themes they share. Tennessee Williams and Arthur Miller depict the family under increasing pressure from the outside as well from the inside. The unit disintegrates, members of the family escape and thus the unit loses its funtions. The pressure is imposed by the tenets of the American mythology that governs the society, which, in turn, influences the family. The common theme of the first group of playwrights is the feeling of loss. This comprises of two dimensions - spatial and tempoval. The second group of playwrights share the same theme of loss with its spatial and temporal implications. They are characteristic by their distinctive use of language that depicts the prevalent sense of doom, apocalypse, futility and sterility. The search for identity is also implied by the restlessness of characters. The detrimental effect of harsh business environment on the family is explored with regards to masculinity. The work shows the family in the context of the 1950s, an era when the family was elevated to...
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Elemental carbon in highly time and size resolved atmosheric aerosol by image analysis
Voldánová, Zdeňka ; Hovorka, Jan (advisor) ; Schwarz, Jaroslav (referee)
In this study a new optical method for highly time and size resolved atmospheric elemental carbon has been described. For this purpose has been used image analysis of 3 DRUM strips with three size fractions deposited (2,5-1,15 µm; 1,15-0,34 µm; 0,34-0,1 µm). Strips were scanned by Fotoscanner HP ScanJet 8200 with optical resolution of 600 dpi. For the analysis of images Matlab program was used, in which the images are transformed to a matrix of grayscale values. The output of this program are time series of grayscale values for each transformed image. Because the time series consist of data in 5 minute intervals, for comparing with hourly PM2,5 EC data obtained from the Sunset EC/OC analyzer, it was necessary to have hourly time series. The precise method of this new approach to determine concentration of atmospheric BC is described in this thesis. In addition, it contains description of the procedures connected with calibrations and controls of sectional outputs. Using linear regression, the daily averages for black carbon are compared with daily EC data. Similarly, hour averages are compared by linear regression also. The analysis performed proved very good relation between daily EC and daily BC described by formula (EC ~ 1.0399 + 0,0117*BC). In respect to hourly averages, a very different...
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