The effect of meteorology and aerosol size distribution on light scattering properties at a rural background site in Central Europe
Suchánková, Lenka
2023 - English The aim of this study is to characterize the light scattering properties of aerosols at the rural background site National Atmospheric\nObservatory Košetice (NAOK; 49°34’20.787”N, 15°4’48.155”E) in Central Europe, namely the coefficients of total light scattering (σsp) and backscattering (σbsp), the Ångström exponent (SAE), the backscattering ratio (b), and the asymmetry factor (g), with special attention to the influence of meteorology and aerosol size distribution on these properties. We measured σ𝑠𝑝 and σ𝑏𝑠𝑝 at three wavelengths (450, 550, and 700 nm) using the Integrating Nephelometer TSI 3563 (PM10 inlet). The measurements were performed from August 16, 2012 to December 31, 2019. Keywords: properties aerosols; backscattering; measurements Available in a digital repository NRGL The effect of meteorology and aerosol size distribution on light scattering properties at a rural background site in Central Europe

The aim of this study is to characterize the light scattering properties of aerosols at the rural background site National Atmospheric\nObservatory Košetice (NAOK; 49°34’20.787”N, 15°4’48.155”E) in ...

Suchánková, Lenka
Ústav chemických procesů, 2023

N-alkylation of a lysergic acid derivative under PTC conditions in a continuous arrangement using sonication
Jaklová, Natalie
2023 - English This contribution focuses on the application of sonication to the synthesis of a methyl ester of the 1-methyl-10α-methoxydihydrolysergic acid (MeLUME). Keywords: sonication; synthesis; methyl ester Available in a digital repository NRGL N-alkylation of a lysergic acid derivative under PTC conditions in a continuous arrangement using sonication

This contribution focuses on the application of sonication to the synthesis of a methyl ester of the 1-methyl-10α-methoxydihydrolysergic acid (MeLUME).

Jaklová, Natalie
Ústav chemických procesů, 2023

PROCESSING OF THE DATA MEASURED WITH CLOUD CONDENSATION NUCLEI COUNTER IN YEAR 2020 FOR SUBMISSION TO EBAS DATABASE
Moravec, Pavel; Jindra, Tomáš; Wagner, Zdeněk; Ždímal, Vladimír
2023 - English Aerosol particles in the atmosphere that allow water vapor to condense and form cloud droplets are called Cloud Condensation Nuclei (CCN). Elevated concentrations of CCN tend to increase the concentration and decrease the size of cloud droplets. This can lead to suppression of precipitation in shallow and short-lived clouds and to greater convective overturning and more precipitation in deep convective clouds, Rose et al.(2010). The response of cloud properties and precipitation processes to increasing anthropogenic aerosol concentrations represents one of the largest uncertainties in the current understanding of climate change. One of the fundamental challenges is to determine the ability of aerosol particles to act as CCN under relevant atmospheric conditions. Knowledge of the spatial and temporal distribution in the atmosphere is essential to incorporate the effects of CCN into meteorological models of all scales, Huang et al. (2007). Long-term CCN measurements are performed at aerosol monitoring sites such as those forming ACTRIS (Aerosols, Clouds, and Trace Gases Research Infrastructure) network. Measured data are then submitted to the EBAS database, where they are available for the other ACTRIS researchers. In this paper, we present our experience with the processing of the data measured with CCNC for submission to the EBAS database. The data prepared for submission to EBAS from year 2020 are also presented. Keywords: atmospheric aerosols; CCNC; cloud condensation nuclei concentrations Available in a digital repository NRGL PROCESSING OF THE DATA MEASURED WITH CLOUD CONDENSATION NUCLEI COUNTER IN YEAR 2020 FOR SUBMISSION TO EBAS DATABASE

Aerosol particles in the atmosphere that allow water vapor to condense and form cloud droplets are called Cloud Condensation Nuclei (CCN). Elevated concentrations of CCN tend to increase the ...

Moravec, Pavel; Jindra, Tomáš; Wagner, Zdeněk; Ždímal, Vladimír
Ústav chemických procesů, 2023

DRONE-BASED VERTICAL MEASUREMENTS OF BLACK CARBON AEROSOLS AT A RURAL BACKGROUND AND AN URBAN SITE
Julaha, Kajal; Zíková, Naděžda; Ždímal, Vladimír
2023 - English Black Carbon (BC) aerosols are primary particles emitted into the atmosphere as a by-product of incomplete combustion processes. BC absorbs solar radiation and altersthe radiation budget of the Earth(Bond et al., 2013). The radiative properties of BC heavily depend on its vertical profiles(Haywood and Ramaswamy, 1998). For example, BC in the free troposphere can enhance its radiative forcing by trapping energy emitted from lower cloud layers. \nThe modeling-based studies on BC vertical distribution are particularly poor (Chen et al., 2022), creating a need to measure the vertical distribution of BC on a regional scale,from areas characterized by anthropogenic emissions from the ground to those characterized by long-range transport(Ramana et al., 2010). Among all the other methods, drones have recently gained popularity because of their high-cost efficiency, flexibility, and mobility. Besides comparing BC aerosol vertical distribution at an urban and a regional background site, this study also calibrates drone measurements using a 230-meter tower. Keywords: vertical profile; drone; rural background Available in a digital repository NRGL DRONE-BASED VERTICAL MEASUREMENTS OF BLACK CARBON AEROSOLS AT A RURAL BACKGROUND AND AN URBAN SITE

Black Carbon (BC) aerosols are primary particles emitted into the atmosphere as a by-product of incomplete combustion processes. BC absorbs solar radiation and altersthe radiation budget of the ...

Julaha, Kajal; Zíková, Naděžda; Ždímal, Vladimír
Ústav chemických procesů, 2023

Summary of the Liquid-Gas Ejector Hydraulic Behavior - Theory and Practice
Gebouský, Ondřej; Haidl, Jan
2023 - English Liquid-gas ejectors (LGEs) are fascinating devices that use the kinetic energy of the liquid jet to entrain and eventually compress the gas. LGEs find applications in both industry and everyday life, e.g., as sprayers. However, a complex and reliable method for LGE design was not available in the open literature until recently. This contribution follows up on our recent works about the hydraulic behavior of LGE with undisturbed and destabilized liquid jets. This paper aims to summarize the device’s complicated hydraulics and characterize its optimal design for three industrially relevant applications - (a) LGE as the vacuum pump, (b) LGE as the gas purification equipment, and (c) LGE as the gas distributor for bioreactors. Keywords: liquid-gas ejector; jet pump; design method Available in digital repository of the ASCR Summary of the Liquid-Gas Ejector Hydraulic Behavior - Theory and Practice

Liquid-gas ejectors (LGEs) are fascinating devices that use the kinetic energy of the liquid jet to entrain and eventually compress the gas. LGEs find applications in both industry and everyday life, ...

Gebouský, Ondřej; Haidl, Jan
Ústav pro hydrodynamiku, 2023

Laboratoř dálkového průzkumu – možnosti využití DPZ
Polák, Mojmír
2023 - Czech Keywords: hyperspektrální data; azbestové střechy; hyperspectral data; asbestos roofs; Linear Spectral Unmixing Available in a digital repository NRGL Laboratoř dálkového průzkumu – možnosti využití DPZ

Polák, Mojmír
CENIA, 2023

Přístroje pro měření úhrnu srážek od historie po současnost
Lipina, P.; Procházka, J.; Tesař, Miroslav
2023 - Czech Úhrn srážek patří mezi nejdůležitější meteorologické prvky. Má zásadní význam pro tvorbu klimatologických charakteristik, je základem vodní bilance a primárně sledovaným prvkem v předpovědní a výstražné službě. Měření srážek je dlouhodobě zatíženo mnoha nejistotami a je mu proto věnována soustavně náležitá pozornost. \nPrvní měření srážek v Evropě se datuje k 17. století. Pravidelná, ale neúplná, měření srážek na pražské klementinské hvězdárně byla zahájena v roce 1752 (nepřetržitá řada od roku 1804), v Brně to bylo v roce 1803. V roce 1817 M. A. David publikoval první německy psaný návod pro pozorování počasí v Čechách určený dobrovolným pozorovatelům. Zásadní vliv pro vznik meteorologických stanic a měření srážek měly aktivity institucí a různých spolků, například pražské Klementinum, Přírodozpytný spolek v Brně, Ústřední ústav pro meteorologii a zemský magnetismus a jiné. Hydrografická komise pro království české a její hydrometrická sekce byla pod vedením F. J. Studničky založena roku 1875, o významné rozšíření měření srážek se v té době zasloužil v rámci budování sítě lesnických srážkoměrných stanic E. Purkyně.\nJiž více než 200 let dochází k vývoji srážkoměrů a metodik měření srážek. V českých zemích dlouhodobě využívaný manuální srážkoměr Metra 886 byl vyvinut podle rakouského vzoru prof. Kostlivého. Od roku 1995 byla zahájena automatizace měření srážek nejprve klopnými srážkoměry, které jsou postupně nahrazovány srážkoměry váhovými. V odlehlých a lesnatých oblastech jsou testovány alternativní způsoby měření srážek. Tento příspěvek se snaží historii, standardy a vývoj v měření srážek u nás alespoň orientačně přiblížit. The precipitation amount is one of the most important meteorological elements. It is of fundamental importance for the creation of climatological characteristics, it is the basis of the water balance and the primarily monitored element in the forecasting and warning service. Precipitation measurement has been burdened with many uncertainties for a long time and is therefore consistently given due attention.\nThe first measurement of precipitation in Europe dates back to the 17th century. Regular but not complete measurements of precipitation at Prague's Klementine observatory began in 1752 (continuous series since 1804), in Brno in 1803. In 1817, M.A. David wrote the first guide for observing the weather in Bohemia, published in German, intended for volunteer observers. The activities of institutions and various associations, such as the Prague Klementinum, the Natural Research Society in Brno, the Central Institute for Meteorology and Earth Magnetism and others, had a fundamental influence on the establishment of meteorological stations and precipitation measurements. The Hydrographic Commission for the Kingdom of the Czech Republic and its hydrometric section were founded in 1875 under the leadership of F. J. Studnička E. Purkyně was responsible for the significant expansion of precipitation measurement at that time as part of the construction of a network of forest precipitation measuring stations. \nFor more than 200 years, rain gauges and precipitation measurements have been developed. The Metra 886 manual rain gauge, which has been used for a long time in the Czech lands, was developed according to the Austrian model of prof. Kostlivý. Since 1995, the automation of rainfall measurement was started, first with tipping bucket raingauges, which are gradually being replaced by weighing raingauges. Alternative methods of measuring precipitation are being tested in\nremote and forested areas. This post tries to bring the history, standards and development of precipitation measurement in our country at least as a guide. Keywords: rain gauge; measurement date; measurement history; meteorological station; guide for observers Fulltext is available at external website. Přístroje pro měření úhrnu srážek od historie po současnost

Úhrn srážek patří mezi nejdůležitější meteorologické prvky. Má zásadní význam pro tvorbu klimatologických charakteristik, je základem vodní bilance a primárně sledovaným prvkem v předpovědní a ...

Lipina, P.; Procházka, J.; Tesař, Miroslav
Ústav pro hydrodynamiku, 2023

Bohl-Marek decomposition applied to a class of biochemical networks with conservation properties
Papáček, Štěpán; Matonoha, Ctirad; Duintjer Tebbens, Jurjen
2023 - English This study presents an application of one special technique, further called as Bohl-Marek decomposition, related to the mathematical modeling of biochemical networks with mass conservation properties. We continue in direction of papers devoted to inverse problems of parameter estimation for mathematical models describing the drug-induced enzyme production networks [3]. However, being aware of the complexity of general physiologically based pharmacokinetic (PBPK) models, here we focus on the case of enzyme-catalyzed reactions with a substrate transport chain [5]. Although our ultimate goal is to develop a reliable method for fitting the model parameters to given experimental data, here we study certain numerical issues within the framework of optimal experimental design [6]. Before starting an experiment on a real biochemical network, we formulate an optimization problem aiming to maximize the information content of the corresponding experiment. For the above-sketched optimization problem, the computational costs related to the two formulations of the same biochemical network, being (i) the classical formulation x˙(t) = Ax(t) + b(t) and (ii) the 'quasi-linear' Bohl-Marek formulation x˙M(t) = M(x(t)) xM(t), can be determined and compared. Keywords: Mathematical modeling; Biochemical network; Pharmacokinetic (PBPK) models Fulltext is available at external website. Bohl-Marek decomposition applied to a class of biochemical networks with conservation properties

This study presents an application of one special technique, further called as Bohl-Marek decomposition, related to the mathematical modeling of biochemical networks with mass conservation properties. ...

Papáček, Štěpán; Matonoha, Ctirad; Duintjer Tebbens, Jurjen
Ústav teorie informace a automatizace, 2023

Validation of numerical simulations of a simple immersed boundary solver for fluid flow in branching channels
Keslerová, R.; Lancmanová, Anna; Bodnár, Tomáš
2023 - English This work deals with the flow of incompressible viscous fluids in a two-dimensional branching channel. Using the immersed boundary method, a new finite difference solver was developed to interpret the channel geometry. The numerical results obtained by this new solver are compared with the numerical simulations of the older finite volume method code and with the results obtained with OpenFOAM. The aim of this work is to verify whether the immersed boundary method is suitable for fluid flow in channels with more complex geometries with difficult grid generation. Keywords: immersed boundary method; finite volume method; OpenFOAM Available in digital repository of the ASCR Validation of numerical simulations of a simple immersed boundary solver for fluid flow in branching channels

This work deals with the flow of incompressible viscous fluids in a two-dimensional branching channel. Using the immersed boundary method, a new finite difference solver was developed to interpret the ...

Keslerová, R.; Lancmanová, Anna; Bodnár, Tomáš
Matematický ústav, 2023

Rooting algebraic vertices of convergent sequences
Hartman, David; Hons, T.; Nešetřil, J.
2023 - English Structural convergence is a framework for convergence of graphs by Nešetřil and Ossona de Mendez that unifies the dense (left) graph convergence and Benjamini-Schramm convergence. They posed a problem asking whether for a given sequence of graphs (Gn) converging to a limit L and a vertex r of L it is possible to find a sequence of vertices (rn) such that L rooted at r is the limit of the graphs Gn rooted at rn. A counterexample was found by Christofides and Král’, but they showed that the statement holds for almost all vertices r of L. We offer another perspective to the original problem by considering the size of definable sets to which the root r belongs. We prove that if r is an algebraic vertex (i.e. belongs to a finite definable set), the sequence of roots (rn) always exists. Keywords: rooting; algebraic vertices; convergent sequences Available in digital repository of the ASCR Rooting algebraic vertices of convergent sequences

Structural convergence is a framework for convergence of graphs by Nešetřil and Ossona de Mendez that unifies the dense (left) graph convergence and Benjamini-Schramm convergence. They posed a problem ...

Hartman, David; Hons, T.; Nešetřil, J.
Ústav informatiky, 2023