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Change in precipitation distribution as temperature rises expressed in diagnostic and prognostic data
Sokol, Zbyněk; Řezáčová, Daniela
2023 - Czech
We summarize the main results that show how the distribution of precipitation changes with increasing temperature. Hourly rainfall totals from 97 rain gauge stations in the Czech Republic for the years 1997 to 2019 are used for the evaluation. Ground temperature, ground dew point temperature and temperature at the lifting condensation level are used to express the temperature change. The results show how an increase in temperature and a corresponding increase in saturation humidity (CC scaling) affects the distribution of precipitation in the study area. In general, the increase in precipitation as a function of observed temperature is clearly evident for the upper quantile values, but only for certain temperature intervals. It confirms the findings of other studies. In this paper, data from reanalyses performed by the ALADIN-CLIMAT/CZ model are treated similarly to the measured data.\n Shrnujeme hlavní výsledky, které ukazují, jak se mění rozdělení srážek s rostoucí teplotou. Hodnocení využívá hodinové úhrny z 97 srážkových stanic z území České republiky za roky 1997 až 2019. Hodnoty přízemní teploty, přízemního rosného bodu a výstupné kondenzační hladiny jsou užity pro vyjádření teplotní změny. Výsledky ukazují, jak se teplotní růst napěti nasycení (CC scaling) projevuje v rozložení hodnot srážek na studovaném území. Obecně se nárůst srážek v závislosti na sledovaných teplotách zřetelně projevuje u horních kvantilů avšak pouze pro určité intervaly teplot, což potvrzuje závěry i jiných prací. V práci jsou obdobně jako naměřená data zpracována data z reanalýz provedených modelem ALADINCLIMAT/CZ.\n
Keywords:
Clausius Clapeiron equation; precipitation; dependence of precipitation intensity on temperature
Available at various institutes of the ASCR
Change in precipitation distribution as temperature rises expressed in diagnostic and prognostic data
We summarize the main results that show how the distribution of precipitation changes with increasing temperature. Hourly rainfall totals from 97 rain gauge stations in the Czech Republic for the ...
Effect of aging on mechanical properties of 3D printed samples using stereolithography
Drechslerová, V.; Falta, J.; Fíla, T.; Dvořák, R.; Kytýř, Daniel
2023 - English
This paper focuses on stereolithography (an additive manufacturing technology working on the principle of curing liquid resins layer by layer using ultraviolet radiation) and the effect of aging on the mechanical properties of the material and printed samples. The aging of the material could be a problem for its subsequent use as the stability of the mechanical properties would not be maintained and unwanted deterioration of the material could occur. As part of the research, sets of samples were printed and subjected to different aging methods and subsequently subjected to quasi-static and dynamic uni-axial load tests. From the data obtained, the basic mechanical properties of the material were calculated and compared with each other. The aim of this paper was to investigate whether aging process causes significant changes in the mechanical properties of the materials used, which could have a consequential impact on their use in different industries.
Keywords:
stereolithography; aging; mechanical properties
Available at various institutes of the ASCR
Effect of aging on mechanical properties of 3D printed samples using stereolithography
This paper focuses on stereolithography (an additive manufacturing technology working on the principle of curing liquid resins layer by layer using ultraviolet radiation) and the effect of aging on ...
Computed tomography system with strict real-time synchronization for in-situ 3D analysis of periodically vibrating objects
Rada, Václav; Fíla, Tomáš; Zlámal, Petr; Koudelka_ml., Petr; Šleichrt, Jan; Macháček, Michael; Vavřík, Daniel; Kytýř, Daniel
2023 - English
In the contribution, we present a laboratory system capable of X-ray computed tomography (XCT) scanning of an periodically moving or oscillating object. The system is an in-house developed XCT setup with electromagnetic voice coil actuator mounted on top of the rotary stage of the setup. The strict synchronization of the components, the rotary stage, the electromagnetic actuator movement and the detector readout is accomplished with use of the detector hardware trigger and hard real-time Linux operating system. Cylindrical sample manufactured from epoxy resin with metal particles to enable movement tracking is scanned in a stationary position and during periodical movement induced by the vibration stage. The volumetric data of the scans is compared and the results of this contribution represent an important step towards identification of defects through modal analysis of in-situ harmonically vibrating object.
Keywords:
computed tomography; hardware trigger; harmonic motion; realtime synchronization
Available at various institutes of the ASCR
Computed tomography system with strict real-time synchronization for in-situ 3D analysis of periodically vibrating objects
In the contribution, we present a laboratory system capable of X-ray computed tomography (XCT) scanning of an periodically moving or oscillating object. The system is an in-house developed XCT setup ...
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, ...
Nanoparticels from brake pads wear
Švábenská, Eva; Roupcová, Pavla; Friák, Martin; Schneeweiss, Oldřich
2023 - English
Exposure to particulate air pollution has been associated with a variety of health problems. One of the main\nsources of metal-rich airborne particulate pollution in roadside environments are brake-wear emissions. The \nscanning electron microscopy (SEM) and transmission electron microscopy (TEM), Mössbauer spectroscopy \n(MS), X-ray powder diffraction (XRD) was used to a make quantitative evaluation of wear particles in two \nsamples. Sizes, morphologies, oxidation state, and trace element compositions of wear particles were\ninvestigated using combination of several methods revealed high concentrations of Fe species and phases, \noften associated with carbonaceous material. SEM and TEM observations show that brake wear particles with \na size of tens to hundreds of nm mainly form particle agglomerates. However, ultrafine (<100 nm) particles are \nlikely to pose a health threat after inhalation and/or ingestion.
Keywords:
Wear particles; analysis; TEM; iron oxides; metallic particles
Available at various institutes of the ASCR
Nanoparticels from brake pads wear
Exposure to particulate air pollution has been associated with a variety of health problems. One of the main\nsources of metal-rich airborne particulate pollution in roadside environments are ...
Instruments for precipitation measurement from history to the present
Lipina, P.; Procházka, J.; Tesař, Miroslav
2023 - Czech
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. 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.
Keywords:
rain gauge; measurement date; measurement history; meteorological station; guide for observers
Fulltext is available at external website.
Instruments for precipitation measurement from history to the present
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 ...
The surface quality of the fused silica machined by ultrafast laser
Novotný, Jan; Mrňa, Libor
2023 - Czech
The quality of ultrafast laser-machined surfaces depends on several process parameters. In the experiment, the parameters window that yields the lowest roughness and lowest number of defects were found. The most important parameter after laser fluence is scan line overlap, which has the biggest impact on residual heat dissipation and related stresses in the specimen. The second harmonic wavelength yielded 10 % better surface roughness, lower waviness, and a lower number of defects on the surface and edges of the processed area. Kvalita povrchu při obrábění ultrakrátkými pulzy závisí na několika procesních parametrech. Testováním vlivu skenovací rychlosti, překryvu linií, energie pulzů a vlnové délky byly nalezeny parametry s nejnižší drsností povrchu a výskytem vad. Zásadní vliv na výslednou kvalitu má, kromě vhodné energie pulzu, překryv linií skenování, který je určující pro rozložení zbytkového tepla a napětí ve vzorku. Při obrábění na druhé harmonické vlnové délce bylo dosaženo o 10 % lepší drsnosti povrchu, nižší vlnitosti a značného omezení defektů povrchu i hran obráběné oblasti.
Keywords:
ultrafast laser; laser ablation; glass; defects
Available at various institutes of the ASCR
The surface quality of the fused silica machined by ultrafast laser
The quality of ultrafast laser-machined surfaces depends on several process parameters. In the experiment, the parameters window that yields the lowest roughness and lowest number of defects were ...
Digital twin skin of the drinking water treatment plant - development and use in practice
Sochorová, Helena; Andreides, D.; Hložanka, F.; Prokopová, Michaela; Stejskal, O.; Chalupa, L.; Šmejkalová, P.; Dolejš, P.
2023 - Czech
The contribution presents experiences with the development of a digital twin for optimizing the control of the DWTP within the pilot project in the Železná Ruda locality. The digital twin consists of two components, i.e. digital documentation in the object architecture processed by the reverse engineering process, which is data-connected with the real physical infrastructure (virtual replica of the infrastructure) and a simulation tool based on a mathematical model or a neural network (simulation of the water treatment process). Both components are accessible to the user via a web application, in which one can choose from three operating states (monitoring of the real state - default, simulation of scenarios of operating settings and prediction of pressure loss). Příspěvek představuje zkušenosti s vývojem digitálního dvojčete pro optimalizaci řízení ÚV v rámci pilotního projektu v lokalitě Železná Ruda. Digitální dvojče se skládá ze dvou komponent, a to digitální dokumentace v objektové architektuře zpracované postupem reverzního inženýrství, která je datově propojená s reálnou fyzickou infrastrukturou (virtuální replika infrastruktury) a ze simulačního nástroje na základě matematického modelu anebo neuronové sítě (simulace procesu úpravy vody). Obě komponenty jsou uživateli přístupné přes webovou aplikaci, ve které lze volit ze tří provozních stavů (monitoring reálného stavu - defaultní, simulace scénářů provozních nastavení a predikce tlakové ztráty).
Keywords:
digital twin; water quality; control optimization; reverse engineering; water treatment
Available at various institutes of the ASCR
Digital twin skin of the drinking water treatment plant - development and use in practice
The contribution presents experiences with the development of a digital twin for optimizing the control of the DWTP within the pilot project in the Železná Ruda locality. The digital twin consists of ...
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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