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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 - anglický
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.
Klíčová slova:
atmospheric aerosols; CCNC; cloud condensation nuclei concentrations
Plné texty jsou dostupné v digitálním repozitáři NUŠL
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 - anglický
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.
Klíčová slova:
vertical profile; drone; rural background
Plné texty jsou dostupné v digitálním repozitáři NUŠL
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 - anglický
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.
Klíčová slova:
Mathematical modeling; Biochemical network; Pharmacokinetic (PBPK) models
Dokument je dostupný na externích webových stránkách.
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 - anglický
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.
Klíčová slova:
immersed boundary method; finite volume method; OpenFOAM
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
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 ...
Are subsidies to business R&D effective? Regression discontinuity evidence from the TA CR ALFA programme
Bajgar, Matěj; Srholec, Martin
2023 - anglický
Governments subsidise business research and experimental development (R&D) to promote development of the economy, because externalities and information asymmetries inherent to the innovation process make private funding of these activities fall short of what is socially desirable. Nevertheless, how effective such subsidies are and whether they achieve their goals is an open question that needs to be studied empirically. This study leverages the state-of-the-art method of regression discontinuity (RD) that allows us to come very close to making causal inferences about the effects of subsidies, to find out whether the Technology Agency of the Czech Republic’s (TA CR) ALFA programme stimulated new business R&D inputs, outputs, and positive economic impacts that would not have happened otherwise.
Klíčová slova:
government subsidies; innovations; economic development
Dokument je dostupný na externích webových stránkách.
Are subsidies to business R&D effective? Regression discontinuity evidence from the TA CR ALFA programme
Governments subsidise business research and experimental development (R&D) to promote development of the economy, because externalities and information asymmetries inherent to the innovation process ...
Rooting algebraic vertices of convergent sequences
Hartman, David; Hons, T.; Nešetřil, J.
2023 - anglický
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.
Klíčová slova:
rooting; algebraic vertices; convergent sequences
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
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 ...
Drivers of Private Equity Activity across Europe: An East-West Comparison
Kočenda, Evžen; Shivendra, R.
2023 - anglický
We investigate the key macroeconomic and institutional determinants of fundraising and investment activities and compare them across Europe, covering 13 Central and Eastern European (CEE) and 16 Western European (WE) countries. Five macroeconomic variables and nineteen institutional variables are selected. These variables are studied using panel data analysis with fixed effects and random effects models over an eleven-year observation period (2010–2020). Bayesian Model Averaging (BMA) is applied to select the key variables. Our results suggest that macroeconomic variables have no significant impact on fundraising and investment activity in either region. Investment activity is a significant driver of fundraising across Europe. Similarly, fundraising and divestment activity are significant drivers of investments across Europe. Institutional variables, however, affect fundraising and investment activity differently. While investment freedom has a significant effect on funds raised in the WE and CEE countries, government integrity and trade freedom are both significant determinants of investments in both European regions. In addition, the results demonstrate that, in contrast to the WE region, fundraising in the CEE region is not country specific. We investigate the key macroeconomic and institutional determinants of fundraising and investment activities and compare them across Europe, covering 13 Central and Eastern European (CEE) and 16 Western European (WE) countries. Five macroeconomic variables and nineteen institutional variables are selected. These variables are studied using panel data analysis with fixed effects and random effects models over an eleven-year observation period (2010–2020). Bayesian Model Averaging (BMA) is applied to select the key variables. Our results suggest that macroeconomic variables have no significant impact on fundraising and investment activity in either region. Investment activity is a significant driver of fundraising across Europe. Similarly, fundraising and divestment activity are significant drivers of investments across Europe. Institutional variables, however, affect fundraising and investment activity differently. While investment freedom has a significant effect on funds raised in the WE and CEE countries, government integrity and trade freedom are both significant determinants of investments in both European regions. In addition, the results demonstrate that, in contrast to the WE region, fundraising in the CEE region is not country specific.
Klíčová slova:
Private equity; Fundraising; Investment
Dokument je dostupný na externích webových stránkách.
Drivers of Private Equity Activity across Europe: An East-West Comparison
We investigate the key macroeconomic and institutional determinants of fundraising and investment activities and compare them across Europe, covering 13 Central and Eastern European (CEE) and 16 ...
Sexual-orientation discrimination and biological attributions: experimental evidence from Russia
Baghumyan, Gayane
2023 - anglický
Understanding what drives discriminatory behavior is important in order to identify the best strategy to combat it. In this study, I exogenously manipulate participants’ beliefs about the origins of sexual orientation by providing evidence that supports biological causes of homosexuality. I employ money allocation tasks to measure discrimination. This allows me to causally identify the impact of information on discriminatory behavior. I first document the prevalence of discrimination against individuals with same-sex partners in Russia. On average, roughly 54% of participants exhibit discriminatory behavior against profiles with same-sex partners by allocating 16 percentage points less money to them. Further, the results suggest that exposure to evidence on the biological causes of homosexuality negatively affects discriminatory behavior. Participants in the treatment group allocate less money to profiles with same-sex partners, relative to participants in the baseline group. Potential rationales for this behavior could include the following: (i) the provision of information that contradicts existing beliefs might cause cognitive dissonance, triggering irritation and intensifying discriminatory tendencies, (ii) the information might foster beliefs that individuals in same-sex partnerships are fundamentally ’other’ - even at a biological level - thereby widening the perceived social gap between participants and these sexual minority groups and fostering discrimination further.
Klíčová slova:
discrimination; information; sexual minorities
Dokument je dostupný na externích webových stránkách.
Sexual-orientation discrimination and biological attributions: experimental evidence from Russia
Understanding what drives discriminatory behavior is important in order to identify the best strategy to combat it. In this study, I exogenously manipulate participants’ beliefs about the origins of ...
Simultaneous online determination of nitric acid and nitrates in ambient air
Alexa, Lukáš; Čmelíková, D.; Cigánková, Hana; Mikuška, Pavel
2023 - anglický
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).
Klíčová slova:
nitric acid; nitrates; online analysis; CGU-ACTJU; CWEDD
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
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 ...
Hostility, population sorting, and backwardness: quasi-experimental evidence from the Red Army after WWII
Ochsner, Christian
2023 - anglický
Does a short episode of conflict or exposure to hostile troops cause regional economic backwardness, and if so, why and how does it persist? I answer these questions by exploiting economic differences across the idiosyncratic and short-lived line of contact between the Red Army and the Western Allies in South Austria at the end of WWII. Spatial regression discontinuity estimates show that hostile presence of the Red Army for 74 days caused an immediate relative population decline of around 12%, amplified to 25% by today. Age-specific migration patterns and subsequent fertility differences explain the multiplying effects. Sector development and measures of local labor productivity in 2011 also lag behind in regions briefly seized by the Red Army, likely driven by skill-specific migration and hampered investment patterns after WWII. The findings provide novel insights into the long-run effects of wars and conflicts, and point to the isolated role of the Red Army’s hostile actions after WWII to understand the European economic East-West divide.\n
Klíčová slova:
conflict; hostility; population shock
Dokument je dostupný na externích webových stránkách.
Hostility, population sorting, and backwardness: quasi-experimental evidence from the Red Army after WWII
Does a short episode of conflict or exposure to hostile troops cause regional economic backwardness, and if so, why and how does it persist? I answer these questions by exploiting economic differences ...
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