It is found that mixed-valence iridium oxides electrodeposited on the surface of a glassy carbon electrode exhibit catalytic activity in the oxidation of caffeine. In this case, a more pronounced ...catalytic effect is obtained on an electrode modified with a composite based on a film of a perfluorinated sulfopolymer (Nafion) and mixed-valence iridium oxides. A selective voltammetric method for the determination of caffeine is developed. A linear logarithmic dependence of current on the caffeine concentration is observed in the range from 1 × 10
–8
to 5 × 10
–3
M. The developed method was used to determine caffeine in energy drinks.
•Model allowing synchronous measurement of flow and structure oscillations.•Experimental data used to validate the one-way and two-way FSI calculations.•Appearing harmonics of the vortex shedding and ...natural frequencies for lock-in mode.
This paper presents results of dynamic measurements of the flow and structure oscillations. We proposed a model consisting of two in-tandem flexible cylinders in the water cross-flow. During the studies, vibration acceleration amplitudes at the shedding frequency and at the cylinders natural frequency were obtained as a function of the flow velocity. The velocity pulsation and pressure pulsation spectra were determined in the flow. A relatively simple structure enabled the use of non-contact measurement systems for cross validation and uncertainty quantifications. The mutual influence of flow and structural dynamics induced by the lock-in effect between the vortex shedding frequency (or its harmonics) and the natural frequency was analyzed. These activities were conducted to generate representative data in order to validate the requirements for hydrodynamic force calculation accuracy and the methods of one-way and two-way coupled FSI calculations.
The Use of Modern Innovative Technologies Shemileva, M. S-A.; Alikhadzhiev, S. Kh; Budnikov, D. A.
SHS Web of Conferences,
2023, Letnik:
172
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
This article explores the use of modern, innovative educational technology in educational settings. It examines the potential benefits of using digital tools and virtual environments in the ...classroom, such as increased engagement, improved understanding of science concepts, and increased collaboration among students. It also addresses the challenges associated with implementing these technologies, such as cost considerations and lack of teacher training. Finally, it presents recommendations for successful implementation and use of these technologies in institutions in education.
A procedure was suggested for voltammetric determination of streptomycin from the catalytic current on a glassy carbon electrode with a composite based on reduced graphene oxide and gold–nickel ...binary system. The working conditions of the electrode modification (volume of the graphene oxide and chitosan suspension, duration of the electrolytic reduction of immobilized graphene oxide and electrodeposition of the gold–nickel binary system) and the conditions for recording the catalytic current in the flow injection system were determined. The procedure for streptomycin determination in a flow, compared to the determination under stationary conditions, is more sensitive, reproducible, and rapid. The streptomycin detection limit was 0.45 nmol, and the productive capacity of the analysis was 60 samples per hour. The streptomycin determination procedure passed trials in analysis of cow milk.
Contemporary small and medium enterprises, such as IT companies and legal, consulting, and logistic firms, use a variety of electronic tools for management purposes to provide their internal ...information exchange. However, there exist a number of problems (vacation registration, project reporting, professional literature issuance, etc.), which do not fit into the existing models of solutions. In similar cases, some IT companies create their own systems for the automation of homotypical procedures, but many firms have no software solutions for their automation. This paper presents the model and architecture of an open-code software for the staff appraisal service as one of the above mentioned unconventional problems. Such a system will enable the application of this flexible and simple solution at small and medium enterprises for frequently occurring management tasks.
Relevance of developing the equipment for electro-hydraulic treatment of water and its solutions was substantiated. The device that is one of the electro-hydraulic spark gap installation components ...has been developed in order to eliminate the drawbacks of similar devices used. The application field of the device for electro-hydraulic treatment of solutions is crop production in agriculture. Electro-hydraulic treatment can be used to produce fertilizers in conditions of irrigation of greenhouse vegetable crops in personal subsidiary and peasant (farmer) farms. The installation, in addition to the cylindrical tank, contains a voltage source, a high-voltage transformer, an autotransformer, energy storage devices, rectifying cells, start-control devices and means of control and measuring. Electrodes are installed in this device, one of which has a technical scientific novelty. The tip of the negative electrode is hemispherical, which allows increasing the stored energy in the capacitor, to increase it in the discharge channel, increasing the length of the spark discharge in the liquid. The model of the device has been developed in order to substantiate the design parameters and operation modes. The developed electric diagram required for installation, runup and control of technological modes of electro-hydraulic impact on liquid media is shown. Actual model of the device is presented in photo content. The perspectivity of studying the electro-hydraulic effect is determined.
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The time and energy resolutions were measured for four prototypes of the PHOS electromagnetic calorimeter for the ALICE experiment at the Large Hadron Collider at CERN. Each prototype was made up ...of nine identical detection elements assembled as a 3 × 3 array. The detection element was based on a lead tungstate (PbWO
4
) scintillating crystal with a length of 180 mm and a cross section of 22 × 22 mm
2
, which was viewed from its end face by a photodetector. Avalanche photodiodes and silicon photomultipliers with different active areas (Hamamatsu, Japan) were used as photodetectors. The measurements were made with the electron component of secondary particle beams of the PS proton synchrotron at CERN in the momentum range of 1−10 GeV/
c
at a temperature of 17.5°C.
It is shown that an increase in the area of photodetectors allows the PHOS electromagnetic calorimeter of the ALICE experiment to operate at room temperature with better spectrometric ...characteristics. The linearity of the calorimeter response has been investigated in the 1–110 GeV energy range using both Hamamatsu S8664-1010 avalanche photodiodes with a large area (10 × 10 mm
2
) and arrays of MPPC Hamamatsu S12572-015C silicon photomultipliers with a sensitive area of 6 × 6 mm
2
. The calorimeter based on avalanche photodiodes is linear in the energy range under investigation compared to a calorimeter composed of silicon-photomultiplier arrays.
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