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Book of abstracts of the 1st outdoor seminar of the Department of Optical Materials: Advances in the new materials engineering and study
Buryi, Maksym; Král, Robert
2023 - English
The seminar is dedicated to the main activities of the department of Optical Materials, FZU - Institute of Physics of the Czech Academy of Sciences in the course of national and international collaborations. In particular, the advanced methods of the (nano)materials synthesis, fabrication, and characterization are presented and discussed in detail. The aim of the seminar is to establish more of the effective paths of communication and data exchange by creating and maintaining links among the teams of national and international experts in various fields of physical and chemical knowledge, both experimental and theoretical. Keywords: nanomaterials; synthesis; data exchange Fulltext is available at external website.
Book of abstracts of the 1st outdoor seminar of the Department of Optical Materials: Advances in the new materials engineering and study

The seminar is dedicated to the main activities of the department of Optical Materials, FZU - Institute of Physics of the Czech Academy of Sciences in the course of national and international ...

Buryi, Maksym; Král, Robert
Fyzikální ústav, 2023

Chemical and microstructural analysis of brick samples from the object of Zákupy castle horse stables
Frankeová, Dita; Bauerová, Pavla; Náhunková, Pavla; Ševčík, Radek; Mácová, Petra; Slížková, Zuzana; Vondráčková, Michaela
2023 - Czech
As part of the construction-technical survey, historical brick samples were characterized using thermal analysis (TGA), scanning electron microscopy (SEM/EDS), ion chromatography (IC), infrared spectrometry (FTIR) and physical tests. The results of the tests testify to the good production quality of the masonry elements used. Based on the analyzes carried out, it can be assumed that the observed damage to the bricks is caused by high wetting of the masonry in combination with frost cycles, as well as crystallization cycles of water-soluble salts present in the surface layer of some bricks. V rámci stavebně-technického průzkumu byl provedena charakterizace vzorků historických cihel s využitím termické analýzy (TGA), skenovacího elektronového mikroskopu (SEM/EDS), iontové chromatografie (IC), infračervené spektrometrie (FTIR) a fyzikálních zkoušek. Výsledky zkoušek cihel z objektu Konírna zámku Zákupy svědčí o dobré výrobní kvalitě použitých zdících prvků. Na základě provedených analýz lze předpokládat, že na pozorovaném poškození cihel se podílí vysoké zavlhčení zdiva v kombinaci s mrazovými cykly, a také krystalizační cykly vodorozpustných solí přítomných v povrchové vrstvě některých cihel. Keywords: TGA; FTIR; masonry; bricks Available at various institutes of the ASCR
Chemical and microstructural analysis of brick samples from the object of Zákupy castle horse stables

As part of the construction-technical survey, historical brick samples were characterized using thermal analysis (TGA), scanning electron microscopy (SEM/EDS), ion chromatography (IC), infrared ...

Frankeová, Dita; Bauerová, Pavla; Náhunková, Pavla; Ševčík, Radek; Mácová, Petra; Slížková, Zuzana; Vondráčková, Michaela
Ústav teoretické a aplikované mechaniky, 2023

Souvislost mezi principem nejmenší akce a termodynamickou podmínkou stability
Maršík, František; Trávníček, Zdeněk; Antošová, Zuzana
2023 - English
The extended principle is formulated for a material point (M.P.) X, which has nonzero mass, temperature, and trajectory x(X,t). The Lagrangian of this variation principle is equal to the kinetic energy from which, the internal energy of the material point (which depends on the entropy) and the additional energy caused by the frictional force are subtracted. The relation between the inertial force and the entropy gradient is found and the gravitational force is completely replaced by the entropy gradient. Thanks to the mentioned properties of the total enthalpy, the Thermodynamic criterion of stability of the state of M.P., is formulated. Keywords: principle of the least action; thermodynamic stability condition; annular swirl flow Fulltext is available at external website.
Souvislost mezi principem nejmenší akce a termodynamickou podmínkou stability

The extended principle is formulated for a material point (M.P.) X, which has nonzero mass, temperature, and trajectory x(X,t). The Lagrangian of this variation principle is equal to the kinetic ...

Maršík, František; Trávníček, Zdeněk; Antošová, Zuzana
Ústav termomechaniky, 2023

Book of Abstracts. 18th Youth Symposium on Experimental Solid Mechanics
Kytýř, Daniel; Doktor, Tomáš; Zlámal, Petr
2023 - English
The YSESM symposium provides a forum for young researchers and engineers, PhD students and students dealing with subjects of experimental mechanics. The Symposium concentrates on current work in all areas of experimental research and its application in solid and fluid mechanics. The topic will particularly concern to: Conventional and Advanced Experimental Methods in Solid and Fluid Mechanics; Non-Destructive Testing and Inspection, Measurements in Material Science, Computer Assisted Testing and Simulation, Engineering Design Simulation, Hybrid Methods, Experimental Techniques – Numerical Simulation, Optical Methods and Image Processing, Measurements in Biomechanics, Sensor Techniques for Micro- and Nano-Applications, Measurement Methods for Forensic Engineering. Keywords: experimental mechanics; fluid mechanics; mechanics of solids Fulltext is available at external website.
Book of Abstracts. 18th Youth Symposium on Experimental Solid Mechanics

The YSESM symposium provides a forum for young researchers and engineers, PhD students and students dealing with subjects of experimental mechanics. The Symposium concentrates on current work in all ...

Kytýř, Daniel; Doktor, Tomáš; Zlámal, Petr
Ústav teoretické a aplikované mechaniky, 2023

Investigation of basic mechanical and fracture-mechanical properties of specimens cut from high pressure gas pipeline – locality L177/2 after a twentyone months exposition to moist and dry hydrogen at the pressure 3 MPa
Gajdoš, Lubomír; Šperl, Martin; Šorm, Filip; Bejdl, Jan
2023 - Czech
Investigation of the effect of moist and dry hydrogen pressurized to 3 MPa on mechanical and fracture properties of gas pipeline steel ČSN 13126, tensile specimens, Charpy specimens and CT specimens were kept loaded during the exposition in moist hydrogen, after a 21th months exposition it was found that ductility of tensile specimens and fracture parameters Jin and J0,2 of CT specimens decreased whilst the parameter Jm was slightly increased. Vyšetření vlivu vlhkého a suchého vodíku stlačeného na tlak 3 MPa na mechanické a lomové vlastnosti plynovodní oceli ČSN 13126, tahové vzorky, Charpy vzorky i CT vzorky byly během expozice ve vlhkém vodíku trvale zatíženy, po 21 měsících expozice byl zjištěn pokles tažnosti tahových vzorků, pokles lomových parametrů Jin a J0,2 a mírné zvýšení parametru Jm. Keywords: stress-strain diagram; Ramberg-Osgood dependence; impact strength; fracture toughness Available at various institutes of the ASCR
Investigation of basic mechanical and fracture-mechanical properties of specimens cut from high pressure gas pipeline – locality L177/2 after a twentyone months exposition to moist and dry hydrogen at the pressure 3 MPa

Investigation of the effect of moist and dry hydrogen pressurized to 3 MPa on mechanical and fracture properties of gas pipeline steel ČSN 13126, tensile specimens, Charpy specimens and CT specimens ...

Gajdoš, Lubomír; Šperl, Martin; Šorm, Filip; Bejdl, Jan
Ústav teoretické a aplikované mechaniky, 2023

Estimation of EDZ zones in great depths by elastic-plastic models
Sysala, Stanislav
2023 - English
This contribution is devoted to modeling damage zones caused by the excavation of tunnels and boreholes (EDZ zones) in connection with the issue of deep storage of spent nuclear fuel in crystalline rocks. In particular, elastic-plastic models with Mohr-Coulomb or Hoek-Brown yield criteria are considered. Selected details of the numerical solution to the corresponding problems are mentioned. Possibilities of elastic and elastic-plastic approaches are illustrated by a numerical example. Keywords: tunnel stability; EDZ zones; elasto-plasticity; finite element method Fulltext is available at external website.
Estimation of EDZ zones in great depths by elastic-plastic models

This contribution is devoted to modeling damage zones caused by the excavation of tunnels and boreholes (EDZ zones) in connection with the issue of deep storage of spent nuclear fuel in crystalline ...

Sysala, Stanislav
Ústav geoniky, 2023

Annular Impinging Jets and an Active Control of Hysteretic Effects
Devani, Yogendrasasidhar; Antošová, Zuzana; Trávníček, Zdeněk
2023 - English
An annular impinging air jet with and without flow control was studied experimentally using measurements of the wall pressure and flow velocity by the Pitot probe. To investigate flow control swirling effects, eight synthetic jets were generated from the nozzle center body. The experiments cover Reynolds numbers 4000–10,000 (evaluated from the outer exit diameter of the annular nozzle). For Re<9000, the bistability and hysteresis were identified and two different flow field patterns (A, B) were found under the same boundary conditions. For higher Re>9000, the hysteresis were not found. Keywords: annular jet; impinging jet; hysteresis Available at various institutes of the ASCR
Annular Impinging Jets and an Active Control of Hysteretic Effects

An annular impinging air jet with and without flow control was studied experimentally using measurements of the wall pressure and flow velocity by the Pitot probe. To investigate flow control swirling ...

Devani, Yogendrasasidhar; Antošová, Zuzana; Trávníček, Zdeněk
Ústav termomechaniky, 2023

Spherical basis function approximation with particular trend functions
Segeth, Karel
2023 - English
The paper is concerned with the measurement of scalar physical quantities at nodes on the $(d-1)$-dimensional unit sphere surface in the hbox{$d$-dimensional} Euclidean space and the spherical RBF interpolation of the data obtained. In particular, we consider $d=3$. We employ an inverse multiquadric as the radial basis function and the corresponding trend is a polynomial of degree 2 defined in Cartesian coordinates. We prove the existence of the interpolation formula of the type considered. The formula can be useful in the interpretation of many physical measurements. We show an example concerned with the measurement of anisotropy of magnetic susceptibility having extensive applications in geosciences and present numerical difficulties connected with the high condition number of the matrix of the system defining the interpolation. Keywords: spherical interpolation; spherical radial basis function; inverse multiquadric Available in digital repository of the ASCR
Spherical basis function approximation with particular trend functions

The paper is concerned with the measurement of scalar physical quantities at nodes on the $(d-1)$-dimensional unit sphere surface in the hbox{$d$-dimensional} Euclidean space and the spherical RBF ...

Segeth, Karel
Matematický ústav, 2023

Semantic segmentation using support vector machine classifier
Pecha, Marek; Langford, Z.; Horák, David; Tran Mills, R.
2023 - English
This paper deals with wildfire identification in the Alaska regions as a semantic segmentation task using support vector machine classifiers. Instead of colour information represented by means of BGR channels, we proceed with a normalized reflectance over 152 days so that such time series is assigned to each pixel. We compare models associated with $\mathcal{l}1$-loss and $\mathcal{l}2$-loss functions and stopping criteria based on a projected gradient and duality gap in the presented benchmarks. Keywords: wildfire identification; semantic segmentation; support vector machines; distributed training Fulltext is available at external website.
Semantic segmentation using support vector machine classifier

This paper deals with wildfire identification in the Alaska regions as a semantic segmentation task using support vector machine classifiers. Instead of colour information represented by means of BGR ...

Pecha, Marek; Langford, Z.; Horák, David; Tran Mills, R.
Ústav geoniky, 2023

Instrumental neutron activation analysis of psychoactive substances, mainly heroin, cocaine, metamphetamine and their adulterants
Kameník, Jan; Kučera, Jan
2023 - Czech
Instrumental neutron activation analysis (INAA) is a robust analytical method theoretically well descibed and understood. INAA works with solid samples, dissolution is not required. The methodology introduces INAA background and lists procedures used for quality control. Protocols for INAA of heroin, cocaine and methamphetamine are described in details. Applications of INAA for psychoactive substances includes estimation of purity and adulterants used and drogs profiling. The metodology is based on measurement of laboratory and real samples. Instrumentální neutronová aktivační analýza je založena na robustním teoretickém základu a umožňuje analýzu vzorků v pevném stavu bez nutnosti jejich převedení do roztoku. Text metodiky zahrnuje představení základů INAA a příklady postupů používaných pro kontrolu přesnosti výsledků. Uveden je popis postupu analýzy heroinu, kokainu a metamfetaminu. Aplikace pro využití INAA zahrnují odhad čistoty a použitých ředících látek a profilování vzorků drog. Metodika je založena na analýze laboratorních a reálných vzorků. Keywords: NAA; psychotropic substances; methodology Available at various institutes of the ASCR
Instrumental neutron activation analysis of psychoactive substances, mainly heroin, cocaine, metamphetamine and their adulterants

Instrumental neutron activation analysis (INAA) is a robust analytical method theoretically well descibed and understood. INAA works with solid samples, dissolution is not required. The methodology ...

Kameník, Jan; Kučera, Jan
Ústav jaderné fyziky, 2023

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