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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).
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 ...
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 ...
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. ...
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 ...
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 ...
Simultaneous online determination of nitric acid and nitrates in ambient air
Alexa, Lukáš; Čmelíková, D.; Cigánková, Hana; Mikuška, Pavel
2023 - English
The innovated method for the simultaneous online determination of HNO3/NO3- in ambient air was developed. Due to high sensitivity of CLD (LOD = 5.1 nM in water solution, 3 s/n) no preconcentration method is required. The online methods were compared with the results obtained with the offline method based on sampling using filters and dry denuders (DD) covered by 0.5% NaF with subsequent analysis by ion chromatography (model ICS-2100, Dionex, USA) and capillary electrophoresis (model Agilent 7100, Agilent Technologies, USA).
Keywords:
nitric acid; nitrates; online analysis; CGU-ACTJU; CWEDD
Available in digital repository of the ASCR
Simultaneous online determination of nitric acid and nitrates in ambient air
The innovated method for the simultaneous online determination of HNO3/NO3- in ambient air was developed. Due to high sensitivity of CLD (LOD = 5.1 nM in water solution, 3 s/n) no preconcentration ...
On the problem of singular limit
Caggio, Matteo; Ducomet, B.; Nečasová, Šárka; Tang, T.
2023 - English
We consider the problem of singular limit of the compressible Euler system confined to a straight layer Ωδ = (0, δ)×R², δ > 0. In the regime of low Mach number limit and reduction of dimension the convergence to the strong solution of the 2D incompressible Euler system is shown.
Keywords:
compressible Euler equations; dissipative measure-valued solutions; low Mach number; thin domain
Available in digital repository of the ASCR
On the problem of singular limit
We consider the problem of singular limit of the compressible Euler system confined to a straight layer Ωδ = (0, δ)×R², δ > 0. In the regime of low Mach number limit and reduction of dimension the ...
Deep learning methods for the acoustic emission methods to evaluate an onset of plastic straining
Parma, Slavomír; Kovanda, Martin; Chlada, Milan; Štefan, Jan; Kober, Jan; Feigenbaum, H. P.; Plešek, Jiří
2023 - English
Development of phenomenological plasticity models, hardening rules, and plasticity theories relies on experimental data of plastic straining. The experimental data are usually measured as the stress–strain response of the material being loaded and do not provide any clues or information about the local response of\nmaterial. In this paper, we analyze the plastic deformation of the material using the acoustic emission method and current state-of-the-art neural network models such as the InceptionTime architecture.
Keywords:
metal plasticity; strain hardening; acoustic emission; neural networks
Fulltext is available at external website.
Deep learning methods for the acoustic emission methods to evaluate an onset of plastic straining
Development of phenomenological plasticity models, hardening rules, and plasticity theories relies on experimental data of plastic straining. The experimental data are usually measured as the ...
Model order reduction for particle-laden flows: systems with rotations and discrete transport operators
Kovárnová, A.; Isoz, Martin
2023 - English
In the present work, we concentrate on particle-laden flows as an example of industry-relevant transport-dominated systems. Our previously-developed framework for data-driven model order reduction (MOR) of such systems, the shifted proper orthogonal decomposition with interpolation via artificial neural networks, is further extended by improving the handling of general transport operators. First, even with intrusive MOR approaches, the underlying numerical solvers can provide only discrete realizations of transports linked to the movement of individual particles in the system. On the other hand, our MOR methodology requires continuous transport operators. Thus, the original framework was extended by the possibility to reconstruct continuous approximations of known discrete transports via another artificial neural network. Second, the treatment of rotation-comprising transports was significantly improved.
Keywords:
model order reduction; shifted POD; artificial neural networks; CFD-DEM; Open- FOAM
Fulltext is available at external website.
Model order reduction for particle-laden flows: systems with rotations and discrete transport operators
In the present work, we concentrate on particle-laden flows as an example of industry-relevant transport-dominated systems. Our previously-developed framework for data-driven model order reduction ...
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