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3D-printed Electrodes with Nearly Ideal Charge Transfer Characteristics
Vaněčková, Eva; Sebechlebská, Táňa; Kolivoška, Viliam
2024 - anglický
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.
Klíčová slova:
three-dimensional printing; electrochemistry; electrodes
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 ...
Growth and Phosphorus Dynamics During Tolypothrix tenuis Cultivation – a Cyanobacterium of Biotechnological Potential
Mušálková, Petra
2024 - anglický
Here I investigated the course of biomass growth, phosphorus uptake and changes in intracellular phosphorus content in T. tenuis in a batch cultivation. Cultivation experiment was held in multiple bubble columns during a light regime (alternating light and dark periods 16 and 8h). Thanks to this experiment I was able to obtain a growth curve of T. tenuis. The decrease of phosphorus concentration in the medium was disproportionally faster\nthan biomass growth resulting in significant oscillations of phosphorus content in the biomass, which are typical characteristics for LPU. It was also observed, that after all phosphorus was removed from the medium, the algae growth continues over time, while obviously utilizing intracellular phosphorus reserves. These findings are valuable in course of using this cyanobacterium for efficient bioremediation of eutrophic water based on phosphorus removal by targeted algae cultivation.
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Growth and Phosphorus Dynamics During Tolypothrix tenuis Cultivation – a Cyanobacterium of Biotechnological Potential
Here I investigated the course of biomass growth, phosphorus uptake and changes in intracellular phosphorus content in T. tenuis in a batch cultivation. Cultivation experiment was held in multiple ...
Influence of Material Properties and Mixing Dynamics on Heat Transport in Granular Materials
Kokavcová, Anna
2024 - anglický
This study evaluates the effect of rotational speed on heat transfer and analyzes particle motion at different stirrer rotational frequencies to understand how primary and secondary flows affect heat transfer efficiency. It also examines the effect of Young’s modulus on heat transfer at different agitator\noperating speeds. Key simulation parameters and their influence 33 on heat transfer efficiency are detailed to improve the reproducibility and applicability of the results.
Klíčová slova:
granular mixing; heat transfer; DEM
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Influence of Material Properties and Mixing Dynamics on Heat Transport in Granular Materials
This study evaluates the effect of rotational speed on heat transfer and analyzes particle motion at different stirrer rotational frequencies to understand how primary and secondary flows affect heat ...
Numerical study of the steady airflow in the human respiratory system during inhaling and exhaling
Lancmanová, Anna; Bodnár, Tomáš
2024 - anglický
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.
Klíčová slova:
human airways; incompressible Navier-Stokes; OpenFOAM
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
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 - český
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.
Klíčová slova:
Richard Wagner; travelling to artists
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
natural frequencies; vibration; blade; laser; turbine
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
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 - anglický
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.
Klíčová slova:
oxidation; reduction; IR spectrochemistry
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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 - anglický
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.
Klíčová slova:
pencil graphite electrode; spectroelectrochemistry; 3D printed electrode
Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
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. ...
Assessment of the Presence of Hazardous Components in Textile Waste
Shtukaturova, Anastasia
2024 - anglický
An up-flow percolation test was chosen to identify and characterize heavy metals and PFAS constituents in textile waste. Up-flow column percolation tests are used on a laboratory scale to assess the leaching behavior of a hazardous substance from a waste in a given state as a function of time. The test was performed according to the European Technical Standard CEN/TS 14405. Preliminary results showed the following heavy metals in the leachates Al, As, Co, Cr, Cu, Fe, Mn, Pb, Zn and Sb, with Al, Cr, Fe, Mn and Zn being predominant.
Klíčová slova:
textile waste; percolation test; PFAS; heavy metals
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Assessment of the Presence of Hazardous Components in Textile Waste
An up-flow percolation test was chosen to identify and characterize heavy metals and PFAS constituents in textile waste. Up-flow column percolation tests are used on a laboratory scale to assess the ...
Drone Based Vertical Profiling of Black Carbon Aerosols at a Rural Background and an Urban Site in Central Europe
Julaha, Kajal
2024 - anglický
This research aims to assess the vertical distribution of BC aerosols using a drone and micro Aethalometer AE51 at two distinct sites in the Czech Republic: 1. NAOK (National Atmospheric Observatory Košetice) representing a regional background, and 2. MFF (Faculty of Mathematics and Physics in Prague) representing an urban site. At NAOK, a 250-meter measurement tower is accessible, providing a means to validate and calibrate the drone measurements.
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Drone Based Vertical Profiling of Black Carbon Aerosols at a Rural Background and an Urban Site in Central Europe
This research aims to assess the vertical distribution of BC aerosols using a drone and micro Aethalometer AE51 at two distinct sites in the Czech Republic: 1. NAOK (National Atmospheric Observatory ...
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