No (20995)
Yes (2665)
Number of found documents:
23660
Published from
to
Electrochemical Properties of Newly Synthesized Selaginpulvilins
Dostálová, L.; Sokolová, Romana; Schwarzová-Pecková, K.; Rýček, L.
2024 - English
The electrochemical properties of newly synthesized selaginpulvilin were investigated by cyclic voltammetry and UV-Vis spectroelectrochemistry. The subject of the study were two\nselaginpulvilins differing in the presence of a hydroxyl group in the media of 0.1 mol L-1 tetrabutylammonium hexafluorophosphate as supporting electrolyte in anhydrous acetonitrile. Both\ncompounds provided an oxidative signal in the positive region until +2.0 V.
Keywords:
oxidation; cyclic voltammetry; selaginpulvilins
Available on request at various institutes of the ASCR
Electrochemical Properties of Newly Synthesized Selaginpulvilins
The electrochemical properties of newly synthesized selaginpulvilin were investigated by cyclic voltammetry and UV-Vis spectroelectrochemistry. The subject of the study were two\nselaginpulvilins ...
3D-printed Electrodes with Nearly Ideal Charge Transfer Characteristics
Vaněčková, Eva; Sebechlebská, Táňa; Kolivoška, Viliam
2024 - English
3D printing is an outstanding manufacturing tool for prototyping customized designs at reduced time and costs, having found applications in fields such as medicine or the automotive industry. The development of printable electrically conductive composite materials brought a revolution to electrochemistry, with 3D-printed electrodes being intensively studied from the viewpoint of\nanalytical performance and stability. However, it is often reported that 3D-printed electrodes have poor charge transfer characteristics, typically due to limited exposure of the electrically conductive phase at the composite surface to the surrounding solution. In this work, we devise and apply simple electrochemical activation procedures that lead to a significant improvement of charge transfer characteristics of 3D printed electrodes.
Keywords:
three-dimensional printing; electrochemistry; electrodes
Available on request at various institutes of the ASCR
3D-printed Electrodes with Nearly Ideal Charge Transfer Characteristics
3D printing is an outstanding manufacturing tool for prototyping customized designs at reduced time and costs, having found applications in fields such as medicine or the automotive industry. The ...
Numerical study of the steady airflow in the human respiratory system during inhaling and exhaling
Lancmanová, Anna; Bodnár, Tomáš
2024 - English
This paper presents some of the initial results of the numerical simulations of a steady turbulent flow in human upper airways during inhalation and exhalation. The mathematical model is based on the system of Reynolds-Averaged incompressible Navier-Stokes equations complemented by the SST k − ω turbulence model. The simulations were performed using finite-volume open source solver OpenFOAM on a realistic three-dimensional geometry. The main aim of this particular study is to verify the computational setup with special focus on appropriate choice and implementation of boundary conditions. The prescribed boundary conditions are chosen to mimic the physiological conditions during normal breathing cycle. This study aims to gain an insight into the airflow behavior during the inhalation and exhalation process by comparing the results of two distinct simulations corresponding to two different (opposite) flow rates . The obtained local flow rates and flow fields for both cases are presented and mutually compared. This initial work should serve as a foundation for future more complex simulations that will include the time-dependent and compressible effects.
Keywords:
human airways; incompressible Navier-Stokes; OpenFOAM
Available in digital repository of the ASCR
Numerical study of the steady airflow in the human respiratory system during inhaling and exhaling
This paper presents some of the initial results of the numerical simulations of a steady turbulent flow in human upper airways during inhalation and exhalation. The mathematical model is based on the ...
Česká putování za Richardem Wagnerem
Fránek, Michal; Kopecký, J.
2024 - Czech
Studie zkoumá fenomén českých cest za slavným německým skladatelem Richardem Wagnerem a do míst spojených s jeho kultem (Mnichov, Bayreuth, Curych atd.). Zaměřuje se na wagnerovské cesty – uskutečněné i neuskutečněné – českých skladatelů (Bedřich Smetana, Antonín Dvořák, Zdeněk Fibich, Josef Bohuslav Foerster), interpretů (Ema Destinnová, Karel Burian aj.), hudebních kritiků (Otakar Hostinský, V. V. Zelený), malířů (Jaroslav Čermák) a spisovatelů (Julius Zeyer, Jaroslav Maria, Teréza Nováková), přičemž sleduje jejich různé motivace. The study explores the phenomenon of Czech travels to famous German composer Richard Wagner and to the places associated with his cult (Munich, Bayreuth, Zurich, etc.). It focuses on the Wagnerian journeys – accomplished and not – of Czech composers (Bedřich Smetana, Antonín Dvořák, Zdeněk Fibich, Josef Bohuslav Foerster), performers (Ema Destinnová, Karel Burian, etc.), music critics (Otakar Hostinský, V. V. Zelený), painters (Jaroslav Čermák) and writers (Julius Zeyer, Jaroslav Maria, Teréza Nováková), tracing their different motivations.
Keywords:
Richard Wagner; travelling to artists
Available at various institutes of the ASCR
Česká putování za Richardem Wagnerem
Studie zkoumá fenomén českých cest za slavným německým skladatelem Richardem Wagnerem a do míst spojených s jeho kultem (Mnichov, Bayreuth, Curych atd.). Zaměřuje se na wagnerovské cesty – uskutečněné ...
Verification of the dynamic properties of a new model turbine wheel with free blades
Voronova, Evgeniya; Procházka, Pavel; Maturkanič, Dušan; Mekhalfia, Mohammed Lamine; Hodboď, Robert
2024 - English
The paper describes a new experimental model of turbine wheel with free blades. Verification tests were carried out using a Doppler laser vibrometer, with a focus on the equipment parameters under various conditions. The measurements were performed in the Laboratory of Rotational Laser Vibrometry originated at the Institute of Thermomechanics AS CR, v.v.i.
Keywords:
natural frequencies; vibration; blade; laser; turbine
Available at various institutes of the ASCR
Verification of the dynamic properties of a new model turbine wheel with free blades
The paper describes a new experimental model of turbine wheel with free blades. Verification tests were carried out using a Doppler laser vibrometer, with a focus on the equipment parameters under ...
Reaction Mechanisms of Psychoactive Compounds
Sokolová, Romana; Beneš, Marek; Jiroušková, Eliška; Degano, I.
2024 - English
The reaction mechanism of selected new psychoactive substances (NPS) 4-methylpentedrone and 2-(((4-ethyl-2,5-dimethoxyphenethyl)amino)methyl)phenol was investigated based on their\nelectrochemical and spectroelectrochemical properties. Both drugs were examined by means of cyclic voltammetry using diagnostic parameters for particular reaction schemes, UV/Vis, and IR\nspectroelectrochemistry. Since water participates in the redox mechanism of both studied compounds, the reaction mechanism was studied under a controlled amount of water in an\nacetonitrile environment.
Keywords:
oxidation; reduction; IR spectrochemistry
Available on request at various institutes of the ASCR
Reaction Mechanisms of Psychoactive Compounds
The reaction mechanism of selected new psychoactive substances (NPS) 4-methylpentedrone and 2-(((4-ethyl-2,5-dimethoxyphenethyl)amino)methyl)phenol was investigated based on their\nelectrochemical and ...
Spectroelectrochemical Devices for Monitoring of Intermediates and Products on Carbonbased Composite Electrodes
Vaněčková, Eva; Šikula, M.; Hrdlička, Vojtěch; Sebechlebská, Táňa; Kolivoška, Viliam
2024 - English
Spectroelectrochemistry (SEC), as an interdisciplinary field, provides us with more comprehensive information about electroactive molecules involved in charge transfer reactions. Commercially\navailable SEC cells most often have an incorporated platinum working electrode, which can limit the range of the usable potential window and, in addition, can complicate the analysis due to the\nabsorption phenomenon. In this work, we designed and manufactured two types of custom-made SEC cells employing optically transparent carbon-based working electrodes for UV-Vis monitoring of reactants and electrogenerated intermediates and products. The first SEC cell is entirely manufactured by 3D printing using fused deposition modeling (FDM) by combining optically transparent (PET) and electrically conductive (PLA-CB) filaments. The second SEC cell employs pencil graphite (PG) rods as the working electrode (PGE) and its body is manually assembled from quartz slides. The functionality of the FDM 3D printed SEC cell and manually assembled quartz SEC cell were verified by cyclic voltammetry with in situ UV-Vis spectroscopic absorption monitoring of ruthenium(III) acetylacetonate (Ru(ac)3) redox-active probe dissolved in an aqueous or non-aqueous deaerated solvent, respectively. Both presented cells enable complete redox reversible conversion and strictly oxygen-free conditions.
Keywords:
pencil graphite electrode; spectroelectrochemistry; 3D printed electrode
Available on request at various institutes of the ASCR
Spectroelectrochemical Devices for Monitoring of Intermediates and Products on Carbonbased Composite Electrodes
Spectroelectrochemistry (SEC), as an interdisciplinary field, provides us with more comprehensive information about electroactive molecules involved in charge transfer reactions. ...
Numerical evaluation of mass-diffusive compressible fluids flows models
Bodnár, Tomáš; Fraunié, P.
2024 - English
This contribution presents first numerical tests of some recently published alternative models for solution of viscous compressible and nearly incompressible models. All models are solved by high resolution compact finite difference scheme with strong stability preserving RungeKutta time stepping. The two simple but challenging computational test cases are presented, based on the double-periodic shear layer and the Kelvin-Helmholtz instability. The obtained time-dependent flow fields are showing pronounced shear and vorticity layers being resolved by the standard as well as by the new mass-diffusive modified models. The preliminary results show that the new models are viable alternative to the well established classical models.
Keywords:
compressible Navier-Stokes; nearly incompressible flow; mass diffusion; compact finite-difference
Available in digital repository of the ASCR
Numerical evaluation of mass-diffusive compressible fluids flows models
This contribution presents first numerical tests of some recently published alternative models for solution of viscous compressible and nearly incompressible models. All models are solved by high ...
Motion of fluids in the moving domain
Nečasová, Šárka
2024 - English
It is a survay paper where the problem of the existence of weak solutions of compressible barotropic solutions in a moving bounded domain is studied.
Keywords:
compressible fluid; moving domain; weak solutions
Available in digital repository of the ASCR
Motion of fluids in the moving domain
It is a survay paper where the problem of the existence of weak solutions of compressible barotropic solutions in a moving bounded domain is studied.
Modification of cooling system for laboratory measurement of rotor blade vibration
Maturkanič, Dušan; Procházka, Pavel; Hodboď, Robert; Voronova, Evgeniya; Mekhalfia, Mohammed Lamine
2024 - English
Last year, the replacement of the turbine wheel model was completed in the Laboratory of Rotational Laser Vibrometry of the Institute of Thermomechanics AS CR, v.v.i. Based on previous experience and the expected higher operating load planned for the new wheel, the cooling system was modified at the same time. The paper describes the main effort in this direction and the results that clarify the previous damage of the measuring device.
Keywords:
blade; vibration; cooling system; measurement; laboratory
Available at various institutes of the ASCR
Modification of cooling system for laboratory measurement of rotor blade vibration
Last year, the replacement of the turbine wheel model was completed in the Laboratory of Rotational Laser Vibrometry of the Institute of Thermomechanics AS CR, v.v.i. Based on previous experience and ...
NRGL provides central access to information on grey literature produced in the Czech Republic in the fields of science, research and education. You can find more information about grey literature and NRGL at service web
Send your suggestions and comments to nusl@techlib.cz
Provider
Other bases