Wyniki wyszukiwania - Biblioteka Nauki

1

Distributions of plasma parameters in the gap between two subsequent stabilizing plates in a cascade arc

100%

Książek I.

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tom Vol. 57, No. 2

265-268

EN

Wall-stabilized arcs are commonly used as excitation sources of atoms and low charged ions. Distributions of plasma parameters in the gap between two subsequent stabilizing plates were studied in argon and helium which are commonly used as 'working gas' in experiments aimed at determination of atomic constants. The results were obtained solving set of equations describing plasma in local thermal equilibrium (LTE). As conditions of LTE may be not completely fulfilled obtained absolute values obtained by this method could be deviated from the real one. Nevertheless, the shape of spatial plasma parameters distributions ought to properly represent shape of the plasma. Obtained results reveal very small gradients of plasma parameters in the central part of this gap. This result can be important in future planning of experiments with side-on plasma observation.

2

Nitrogen doped carbon nanotubes and curved lamellas produced via pyrolysis of melamine by direct current arc discharge

80%

Zhao R. I. , Ma Y. , Zhang J. , Li F. , Liu W. , Cui Q.

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tom Vol. 28, No. 1

189--198

EN

Nitrogen doped carbon nanostructures, including nanotubes and barrel like curved lamellas, were fabricated via the pyrolysis of a solo precursor, melamine, in a direct current arc discharge. The samples were characterized by elemental analysis, using XRD, XPS, TEM and SEM in parallel. The nitrogen concentration, determined from the elemental analysis, was shown to be lower than 5%. Nitrogen-based functional groups such as pyridine like structures, the pyrrolic or pyridonic structures, N-amine like structures and substitutional nitrogen within the graphene layers, were observed to coexist in the turbostratic carbon matrix. XRD patterns showed characteristic features of turbostratic carbons. TEM analysis of morphologies showed that nanostructures such as tubes and conglomerations of barrel like curved lamellas were present. The formation of bundles of nanotubes was further confirmed by SEM studies. The inhomogeneity in the morphologies of the nanostructures was attributed to the differences in their growth mechanisms.

3

Badanie prądów potokowych w wyłączniku próżniowym w układzie syntetycznym z wymuszonym obcięciem prądu

70%

Chmielak W.

Wiadomości Elektrotechniczne

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2007

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tom R. 75, nr 11

30-34

PL

Przedstawiono wyniki badań prądu połukowego w układzie syntetycznym z wymuszonym obcięciem prądu oraz procesu adaptacji wyładowania łukowego do przyłożonego wymuszenia.

EN

The paper presents results of uwestigations of after-arc current in synthetic circuit with forced current cut-off. The adaptation of arcing to input funetion is also presented.

4

Wpływ elektrycznych parametrów układu zasilania na charakterystyki reaktorów plazmy łukowej

51%

Komarzyniec G. , Stryczewska H. D. , Janowski W. , Diatczyk J.

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2007

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tom Z. 5

37-44

PL

Dla zapewnienia właściwych parametrów plazmy generowanej w plazmotronach prądu przemiennego należy odpowiednio ukształtować charakterystyki statyczne i dynamiczne układu zasilania. Przy projektowaniu układów zasilania należy uwzględniać wpływ zmian parametrów fizycznych i chemicznych atmosfery jaka występuje w komorze wyładowczej reaktora plazmowego. Uwzględniać należy również oddziaływanie łuku elektrycznego na parametry elektryczne układu zasilania. Wpływ ten jest wyraźnie zauważalny w przypadku stosowania w układach zasilania transformatorów z rdzeniami amorficznymi.

EN

In order to guarantee proper characteristics of plasma generated in AC plasma reactors, static and dynamic parameters of power system should be properly formed. Under the power systems designing process the influence of physical and chemical plasma gas parameters and their changes inside plasma reactor discharge chamber should be considered. The gliding arc discharge influence on electrical parameters of power system should also be taken in to consideration. The effect mentioned above is clearly visible in case of power system transformers with amorphous cores.

5

Synthesis of metallic alloy particles on flat graphitic interfaces in arc discharge

51%

Breus A. , Abashin S. , Serdiuk O. , Sysoiev I.

Archives of Materials Science and Engineering

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2023

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tom Vol. 121, nr 2

49--59

EN

Purpose: The application of arc discharge to synthesising encapsulated (Fe-Cu-Al)@C structures is studied. The cost-effectiveness of the proposed technique may be beneficial for developing a new method for large-scale production of metal micro- and nanoparticles protected from oxidation by a carbon shell. Design/methodology/approach: A copper sample was immersed into a mixture of graphite, iron, and aluminium powder and placed into a negatively powered crucible of a setup designed to ignite arc discharge at atmospheric conditions. The proposed approach prevents the oxidation of droplets of Fe-Cu-Al alloy by covering them with a thin layer of carbon, which is also engaged as a collector of the metal particles. Findings: The application of arc discharge resulted in the generation of metal particles and various carbon nanostructures, which were confirmed by SEM images. The nanostructures were grouped into more complex flower-, ball-, tree-, and octopus-shaped structures with a large yield of metallic alloy particles ranging from a few μm (micrometers) to nanometre sizes. These findings suggest the catalytic application of the structures after the grown particles are cleared from the carbon shell to be implemented as active chemical agents. Research limitations/implications: The main limitation is the uncontrolled heat transfer from the discharge volume. Therefore, an additional screen should be installed around the volume in order to improve control over synthesis in future studies. Practical implications: This research confirms a flexible and simple method of synthesising metallic alloy particles that may be applied for catalytic applications. Originality/value: The synthesis is conducted using a well-known arc discharge technique to expand the production yield and diversity of chemically-active metal particles protected from oxidation by a shell before the intended application.