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Dependence of activated aerosol on horizontal hydrometeor type.
Zíková, Naděžda ; Pokorná, Petra ; Pešice, Petr ; Sedlák, Pavel ; Ždímal, Vladimír
Atmospheric aerosol (AA) affects not only cloud formation, but also other cloud properties such as droplet size distribution, chemical composition, etc. The interaction between AA and cloud does not have to be investigated only by aerial measurements, but the same processes can be observed in fog and low clouds. An example of a station suitable for such research is Milešovka station, where the fog (or low clouds) is 55% of the time. Here, measurements were made to describe the effect of fog on the number size distributions of AA and activated nucleation nuclei.
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Study of Wet Deposition of Atmospheric Aerosol using Horizontal Hydrometeors.
Zíková, Naděžda ; Pokorná, Petra ; Pešice, Petr ; Sedlák, Pavel ; Ždímal, Vladimír
Processes between atmospheric aerosol (AA) and clouds, source of large uncertainty in weather and climate changes estimations, were described on fogs at Milešovka, meteorological observatory of the Institute of Atmospheric Physics. For the description of the AA properties, online measurement of outdoor particle number size distribution (PNSD) in the size range 10 nm – 20 μm was conducted using SMPS and APS spectrometers. The sampling system consisted of a heated whole air inlet, and PM2.5 sampling head, being switched by an automatic valve. From the difference between PNSD sampled by whole air inlet and by PM2.5 inlet, PNSD of activated particles (aPNSD) was calculated. The aPNSDs differ with hydrometeor type and depend on air mass history, with a stronger influence on freezing fog AA.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22019110512030 - PDF
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Cloud Processing of Atmospheric Aerosol Spectra.
Zíková, Naděžda ; Pokorná, Petra ; Pešice, Petr ; Sedlák, Pavel ; Ždímal, Vladimír
Atmospheric aerosol (AA), and its influence on the cloud formation, lifetime and other properties, remains the most uncertain (with low confidence level) element in the IPCC radiative forcing estimations (Stocker et al., 2013). The AA, however, is influenced by the cloud processing as well (Collett et al., 2008., Zíková and Ždímal, 2016). Cloud processing of AA (and vice versa) can be described on fogs, or on low clouds present at a suitable station. An example of such a station is Milešovka, where fog is present for almost 55 % of the time (Fišák et al., 2009), giving a great opportunity to explore the changes in the particle size distributions due to the cloud processing.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22018110212450 - PDF
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Climatology of temperature lapse rate in the lower and middle troposphere
Venclová, Markéta ; Huth, Radan (advisor) ; Sedlák, Pavel (referee)
Klimatologie vertikálního teplotního gradientu ve spodní a střední troposféře Climatology of temperature lapse rate in the lower and middle troposphere Abstract The main objective of this thesis is synoptic-climatological analysis of the temperature lapse rate (γ) in the lower and middle troposphere above the boundary layer at mid-latitudes of the northern hemisphere. The main part of the background research summarizes current knowledge about the mechanism of air temperature change with altitude, the effect of water vapour on γ, and stability conditions in the atmosphere. Radiation and net radiation are discussed to be one of the key factors influencing the behaviour of γ. The following chapter is summarizing findings about temporal and spatial variability of γ. The analysis of γ calculated from 850 and 300 hPa radiosounding data from Praha-Libuš is the core of this thesis. Results were used to describe annual variation of γ. Daily variation was not observed at this altitude. Further, the relationship of γ with air flow direction and Hess-Brezowsky synoptic types was analysed. The results show that the air flow direction and the synoptic situations together with the radiation and the humidity of atmosphere influence the value of γ. Based on the analogous analysis of γ in Poprad-Gánovce were results from...
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What is a connection between atmospheric aerosols, meteorological parameters and gaseous pollutants?
Slezáčková Zíková, Naděžda ; Ždímal, Vladimír (advisor) ; Hovorka, Jan (referee) ; Sedlák, Pavel (referee)
Title: What is the connection between atmospheric aerosols, meteorological pa- rameters and gaseous pollutants? Author: RNDr. Naděžda Slezáčková Zíková Department: Department of Meteorology and Environment Protection Supervisor: Ing. Vladimír Ždímal, Dr. Laboratory of Aerosol Chemistry and Physics, Institute of Chemical Process Fun- damentals, Czech Academy of Sciences, v.v.i. Abstract: Five years of atmospheric aerosol (AA) measurements at rural back- ground station Košetice were compared with meteorological records and gaseous pollutants concentrations. The sampling and data analysis of AA data is de- scribed, and the statistical evaluation is done. The variability in the AA con- centrations is significant; the long-term measurements of AA, over the period at least several years, and the differentiation according to the season of the year are thus necessary. The clearly expressed annual cycle of AA concentrations is mainly influenced by two phenomena. From April to September, the total AA concentration cycle is driven mainly by the new particles formation events, from October to March, the concentrations are strongly influenced by particles coming from long-range transport and/or from the regional pollution. The relationship between AA and meteorological parameters, however, is not only season...
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Vertical temperature profile in atmospheric boundary layer
Gvoždíková, Blanka ; Pešice, Petr (advisor) ; Sedlák, Pavel (referee)
Submitted bachelor thesis discusses the issue of the atmospheric boundary layer. First of all, it addresses the boundary layer's thermal characteristics which are very variable near the Earth's surface. For this purpose we have chosen the observatory in Kopisty near Most where a tower meteorological measurement is performed. In addition the air temperature measurements from Milešovka observatory were included to a dataset, too. It is assumed that this mountain weather station due to its position can represent conditions of the free atmosphere. But if we compare some thermal characteristics of the air at different height levels, we'll figure out that the air temperature measurements at Milešovka are highly influenced by radiation balance of the Earth's surface. Despite this fact, the analysis of air layer between Kopisty and Milešovka gives an idea of a continuous-time behavior of air temperature characteristics. This bachelor thesis describes in detail the air temperature variations and the temperature lapse rate variations in several height levels, the variability of thermal stratification or the incidence and extent of air temperature inversions.
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Atmospheric greenhouse gases - new type of measurements in the Czech Republic
Čermáková, Lenka ; Sedlák, Pavel (advisor) ; Zíková, Naděžda (referee)
The current condition, development and functioning of ecosystems is greatly influenced by the ongoing global change, which is probably caused by the increased concentrations of greenhouse gases in the atmosphere originating from human activity. Ecosystems are able to some extent cope with the consequences of global change on their own, and therefore ensure their future preservation. To understand the forces driving global change, we need detailed quality data from long-term observation. Quantification of substance and energy flows in different ecosystems and ecosystem valuation ability to bind air carbon allows us to model their development, both in current conditions and under conditions of global change. This thesis presents the current research methods of atmospheric boundary layer flows, while highlighting their advantages and pointing out their drawbacks. It also enables a better understanding of new methods of observation through the tall towers. The thesis presents some of the existing tall towers and describes their ways and methods of measurement. A part of the thesis is devoted to a tall tower which is planned to be built in the Czech Republic between municipalities Košetice and Křešín u Pacova. It provides an overview of methods, instrumental and technical equipment and facilities of the new tall...
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Relation among cloudiness, meteorological conditions, and orography in the region of Krušné hory Mts.
Rajtmajer, Jakub ; Müller, Miloslav (advisor) ; Sedlák, Pavel (referee)
The work deals with relation of cloudiness and orography with regards to meteorological conditions. The Flow over mountains affects the clouds according to the atmospheric stratification and velocity of flow in addition to the shape and the size of the obstacle. The next influence is the intensification of radiation. During daytime it affects cumulus clouds, during nighttime mainly fog and low clouds. Datasets of cloud cover from meteorological stations with different altitude and location considering the position of mountain ridge are used to evaluate cloudiness of Krušné hory region. These are Gera- Leumnitz, Fichtelberg, Kopisty, Milešovka. Annual cycle of cloudiness is characterized by two minims, first at the end of April, second at the beginning of September. The most uniform distribution of cloud cover during the year appears at the station with highest altitude - Fichtelberg. The influence of orography discussed in theoretical part occurred mostly in interaction of radiation, geomorphology and anthropogenic activities in Mostecká pánev region because meteorological station Kopisty dominates in cloud cover from November to January, from March to September it has the lowest cloud cover. key words: cloudiness, orography, Krušné hory, stability of stratification, flow, radiation
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Design of multi-functional machining centre
Sedlák, Pavel ; Holub, Michal (referee) ; Blecha, Petr (advisor)
This master thesis deals with the construction of multi-functional machining centre. The theoretical part describes the history of lathes, trends in production of lathes and individual machine parts. The practical part is the structural design of the spindle with positioning in the C axis, the second spindle (including drive in Z axis) and the turret (including drive in the X and Z axis). A 3-D model of the entire lathe assembly modeled in Autodesk Inventor 2010 is also included.
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Steam turbine
Sedlák, Pavel ; Novotný, Zdeněk (referee) ; Fiedler, Jan (advisor)
The diploma thesis concentrates on a project of condensing steam turbine with uncontrolled extraction. These topics are analyzed in more detail: design of thermal diagram, thermodynamic calculation and turbine design concepts. First two topics are solved in the calculation section of the thesis. In the construction part are processed a third topic.
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