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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 ...
An Enzymatic Biosensor with Amperometric Detection in a Flow Injection Analysis for the Determination of L-lactic Acid: Development and Application
Tvorynska, Sofiia; Barek, J.; Josypčuk, Bohdan
2023 - English
An amperometric biosensor consisting of an enzymatic mini-reactor (lactate oxidase covalently\nattached to −NH2 functionalized mesoporous silica powder SBA−15 using glutaraldehyde) and\na silver amalgam-based screen-printed electrode acting as a transducer was developed for the\ndetermination of L-lactic acid (LA) in FIA. The detection potential of −0.9 V vs. Ag pseudoreference\nelectrode was applied for cathodic detection of enzymatically consumed oxygen.\nUnder the optimized conditions, the constructed biosensor enabled selective determination of\nLA with a micromolar limit of detection. Importantly, the proposed biosensor represented\nexcellent operational stability after ≥350 measurements. Finally, it was successfully applied to\nreal sample analysis.
Keywords:
L-lactic acid; Lactate oxidase; Amperometric biosensor; silver amalgam
Available on request at various institutes of the ASCR
An Enzymatic Biosensor with Amperometric Detection in a Flow Injection Analysis for the Determination of L-lactic Acid: Development and Application
An amperometric biosensor consisting of an enzymatic mini-reactor (lactate oxidase covalently\nattached to −NH2 functionalized mesoporous silica powder SBA−15 using glutaraldehyde) and\na silver ...
Identification of quasiperiodic processes in the vicinity of the resonance
Fischer, Cyril; Náprstek, Jiří
2023 - English
In nonlinear dynamical systems, strong quasiperiodic beating effects appear due to combination of self-excited and forced vibration. The presence of symmetric or asymmetric beatings indicates an exchange of energy between individual degrees of freedom of the model or by multiple close dominant frequencies. This effect is illustrated by the case of the van der Pol equation in the vicinity of resonance. The approximate analysis of these nonlinear effects uses the harmonic balance method and the multiple scale method.
Keywords:
dynamical systems; quasiperiodic response; van der Pol equation
Available at various institutes of the ASCR
Identification of quasiperiodic processes in the vicinity of the resonance
In nonlinear dynamical systems, strong quasiperiodic beating effects appear due to combination of self-excited and forced vibration. The presence of symmetric or asymmetric beatings indicates an ...
Laboratory X-ray imaging in material sciences
Koudelka_ml., Petr; Kytýř, Daniel; Jiroušek, O.
2023 - English
In recent decades, X-ray imaging and computed (micro)tomography (XCT) in particular have become common tools for volumetric inspection, visualization, and analysis of internal structure in materials from various fields [1]. In this lecture, we will explore various applications of laboratory X-ray imaging chains utilizing the combination of tomographical imaging with mechanical, thermal, or chemical loading of the irradiated sample in a so-called time-resolved imaging allowing for unprecedented insight into different phenomena driving fundamental processes encountered in various fields of material science. We will show that failure processes in engineering or geological materials [2] can be thoroughly studied by synergy of information from radiographical imaging and other methods including acoustic emission detection and optical measurements via high-speed visible-spectrum and thermal-imaging cameras, where the radiography provides important spatial information regarding deformation processes evolving within the tested samples that could not be obtained otherwise. The state-of-the-art the laboratory based imaging chains for investigation of dynamic response of materials under loading will be also discussed including high speed X-ray radiography utilizing a powerful X-ray source during high velocity impact as an approach suitable for inspection of an impacted sample. As an alternative to both conventional high-power sources and accelerator facilities, capabilities of a flash X-ray system developed primarily for in-situ ballistics research providing very short bursts of an extremely powerful intermittent X-ray radiation with a typical duration of dozens of nanoseconds will be shown.
Keywords:
X-ray imaging; material characterization; mechanical properties
Available at various institutes of the ASCR
Laboratory X-ray imaging in material sciences
In recent decades, X-ray imaging and computed (micro)tomography (XCT) in particular have become common tools for volumetric inspection, visualization, and analysis of internal structure in materials ...
Interpolation with restrictions -- role of the boundary conditions and individual restrictions
Valášek, Jan; Sváček, P.
2023 - English
The contribution deals with the remeshing procedure between two computational finite element meshes. The remeshing represented by the interpolation of an approximate solution onto a new mesh is needed in many applications like e.g. in aeroacoustics, here we are particularly interested in the numerical flow simulation of a gradual channel collapse connected with a~severe deterioration of the computational mesh quality. Since the classical Lagrangian projection from one mesh to another is a dissipative method not respecting conservation laws, a conservative interpolation method introducing constraints is described. The constraints have form of Lagrange multipliers enforcing conservation of desired flow quantities, like e.g. total fluid mass, flow kinetic energy or flow potential energy. Then the interpolation problem turns into an error minimization problem, such that the resulting quantities of proposed interpolation satisfy these physical properties while staying as close as possible to the results of Lagrangian interpolation in the L2 norm. The proposed interpolation scheme does not impose any restrictions on mesh generation process and it has a relatively low computational cost. The implementation details are discussed and test cases are shown.
Keywords:
interpolation; Lagrange multiplier; Lagrange projection
Available in digital repository of the ASCR
Interpolation with restrictions -- role of the boundary conditions and individual restrictions
The contribution deals with the remeshing procedure between two computational finite element meshes. The remeshing represented by the interpolation of an approximate solution onto a new mesh is needed ...
Dynamics of dissolved organic carbon in surface water during extreme rainfall-runoff events
Matoušková, M.; Fraindová, K.; Bejčková, M.; Kliment, Z.; Vlach, V.; Vlček, Lukáš
2023 - English
The release of a greater amount of natural organic matter (NOM) within climate change is registered in many catchments with peatbog areas. The aim of our research is to study the dynamics of releasing dissolved organic carbon (DOC) into surface water in headwater areas with peatbogs. DOC concentrations are analysed in relation to extreme rainfall-runoff (R-R) events and according to the hydrological preconditions of the basin. These preconditions are described using selected hydroclimatic variables (14 days before the R-R event). The source data comes from stations of the Faculty of Science, Charles University, and the Czech Hydrometeorological Institute. For the evaluation of relations and processes, the Principal component analysis (PCA), hysteresis loops or Pearson correlation coefficient was used. The lag time of DOCmax for Qmax, the dependence of DOCmax and groundwater levels were studied. The influence of flow rate on the decline and ascent phases of DOC\nconcentrations by hysteresis loops and the influence of the number of partial flow maximums on the amount of transported DOC during the R-R event was analysed. Our first results show that great influence on the dynamic of DOC concentration in surface water has the change in groundwater-levels in the peatbog and the outflow amount during the R-R event. The hydroclimatic preconditions of the basin have also a significant influence on the DOC release. Changes in concentrations during R-R events also occurred for other compounds that were studied additionally. Particularly significant was the increase in metals (mainly Fe, Al, Mn) and base cation (K) and decrease in nitrate nitrogen.
Keywords:
natural organic matter; dissolved organic carbon; peatbog; surface water
Fulltext is available at external website.
Dynamics of dissolved organic carbon in surface water during extreme rainfall-runoff events
The release of a greater amount of natural organic matter (NOM) within climate change is registered in many catchments with peatbog areas. The aim of our research is to study the dynamics of releasing ...
Vowel length in infant-directed speech: the realisation of short-long contrasts in Czech IDS
Svoboda, Michaela; Chládková, Kateřina; Kocjančič Antolík, T.; Paillereau, Nikola; Slížková, P.
2023 - English
When interacting with young children, talkers across many languages use a speech style that reflects positive affect, draws infants' attention, and supposedly facilitates language acquisition. As for the latter, a well-documented feature of infant-directed speech is an exaggeration of spectrally-cued vowel contrasts. Here we tested whether talkers exaggerate also durationally cued contrasts. Sixty-three mothers, native speakers of Czech, were recorded while playing with their infant (4- to 10-month-olds, IDS) and while speaking to an adult (ADS). The durations of the five Czech phonemically short vowels were compared to their long counterparts. Vowel duration (normalised for word duration) was longer in IDS than in ADS more for phonemically long vowels at the younger infant ages, indicating a developmentally specific early exaggeration of length contrasts in Czech infant-directed speech. The present finding suggests that in a language with phonemic length, caregivers' realisation of speech sounds may go beyond merely being longer and slower overall.
Keywords:
infant-directed speech; vowel length; development of early input; Czech
Available on request at various institutes of the ASCR
Vowel length in infant-directed speech: the realisation of short-long contrasts in Czech IDS
When interacting with young children, talkers across many languages use a speech style that reflects positive affect, draws infants' attention, and supposedly facilitates language acquisition. As for ...
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 ...
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