Electronic-state-resolved analysis of high-enthalpy air plasma flows

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Sung Min Jo ◽  
Oh Joon Kwon ◽  
Jae Gang Kim
Keyword(s):  
Electronic State ◽  
Air Plasma ◽  
Plasma Flows ◽  
High Enthalpy

scholarly journals Oxidation Resistance of a Si–TiSi2–MoSi2–TiB2–CaSi2 Coating on a Cf/C–SiC Substrate in High-Speed High-Enthalpy Air Plasma Flows

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2637
Author(s):  
Alexey Astapov ◽  
Lev Rabinskiy ◽  
Olga Tushavina
Keyword(s):  
Oxide Film ◽  
Oxidation Resistance ◽  
High Speed ◽  
Protective Action ◽  
Structural Phase ◽  
Silicon Monoxide ◽  
Air Plasma ◽  
Plasma Flows ◽  
Main Layer ◽  
Static Conditions

The results of a study on the development and testing of a heat-resistant coating in a Si–TiSi2–MoSi2–TiB2–CaSi2 system to protect Cf/C–SiC composites from oxidation and erosional entrainment in high-speed flows are presented here. The coating was formed using firing fusion technology on the powder composition. Oxidation resistance tests were carried out under static conditions in air at 1650 °C and under conditions of interaction with high-speed air plasma flows, with Mach numbers M = 5.5–6.0 and enthalpy 40–50 MJ/kg. The effectiveness of the protective action of the coating was confirmed at surface temperatures of Tw = 1810–1820 °C for at least 920–930 s, at Tw = 1850–1860 °C for not less than 510–520 s, at Tw = 1900–1920 °C for not less than 280–290 s, and at Tw = 1940–1960 °C for not less than 100–110 s. The values of the rate of loss of the coating mass and the rate constant of heterogeneous recombination of atoms and ions of air plasma on its surface were estimated. The performance of the coating was ensured by the structural-phase state of its main layer, and the formation and evolution on its surface during operation of a passivating heterogeneous oxide film. This film, in turn, is composed of borosilicate glass with titanium and calcium liquation inhomogeneities, reinforcing TiO2 microneedles and in situ Si2ON2 fibers. It was shown that at Tw≥ 1850–1860 °C, the generation of volatile silicon monoxide was observed at the “oxide layer–coating” interface, followed by the effects of boiling and breakdown degradation of the oxide film, which significantly reduced the lifespan of the protective action of the coating.

scholarly journals THE PLASMA FLOWS IN SURGICAL PRACTICE

2018 ◽  
Vol 24 (2) ◽  
pp. 93-98
Author(s):  
A. M Shulutko ◽  
Elkhan G. Osmanov ◽  
M. O Chanturiya ◽  
A. D Macharadze
Keyword(s):  
Biological Tissues ◽  
Air Plasma ◽  
Plasma Technology ◽  
Plasma Flows ◽  
Chemical Methods ◽  
Combined Application ◽  
The Given ◽  
Positive Effect ◽  
Subsequent Regeneration ◽  
Efficient Elimination

Nowadays, the various techniques of thermal energy are applied for dissection and coagulation of biological tissues in surgery. The plasma surgery technology is on of the leading one among them. Multiple publications concerning application of plasma flows testify the following advantages: bloodless dissection of tissues, hemostasis and sterilization of wound surface, making of optimal conditions for subsequent regeneration of tissue substrate, especially due to stimulating effect of molecules of exogenous nitrogen oxide (II) of air plasma jet. On the basis of publication data, the analysis is applied to efficiency of the given technology, features of plasma physical effect in various regimen, possibilities of combined application of this technology with other physical chemical methods. The article presents in details historical aspects of development of plasma technology in Russia, types of plasma installations, specific thermal alterations of organs and tissues after plasma processing in surgical regimen. The method was successfully approved in abdominal and thoracic surgery, operative gynecology, stomatology and oncology. However, plasma technology is mostly called-for in contaminated surgery. This technology, in combination with surgical processing, provides efficient elimination of necrotizing masses and pathogenic flora; thorough hemostasis with formation of mechanically isolating scab as a barrier for in-hospital infection. The fast settlement of inflammatory occurrences in the very wound and in tissues of para-vulnar zone and also stimulating effect on regeneration processes testify positive effect of sanation with various plasma flows in treatment regimen.

scholarly journals VISUALIZATION OF THE gas-dynamic STRUCTURE OF PLASMA FLOWS OF A PNK-50 plasma torchusing THE SHADOW METHOD

2018 ◽  
Vol 14 (4) ◽  
pp. 61-68 ◽  
Author(s):  
I P Gulyaev ◽  
V I Kuzmin ◽  
M P Golubev ◽  
P A Tyryshkin ◽  
A V Dolmatov
Keyword(s):  
Plasma Torch ◽  
Dynamic Structure ◽  
Reynolds Numbers ◽  
Air Plasma ◽  
Plasma Flows ◽  
Output Section ◽  
Modes Of Operation ◽  
Turbulent Transition ◽  
Gas Dynamic ◽  
Additional Mode

The paper presents the study of the gas-dynamic structure of air plasma flows produced by the PNK-50 spray torch using the shadow (schlieren) method. The operation of the plasma torch was studied in three different configurations, differing, among other things, by the diameter of the output section of the channel: 6, 8, 10 mm. The subsonic and supersonic modes of operation of the plasma torch were investigated in the range of plasma-forming air flow 1.4-10.5 g / s and arc current range 140-230 A.In all typical modes of operation of the plasma torch, the flow has a developed turbulent structure with a full angle of jet opening between 23 and 27 degrees. An additional mode of operation of the plasma torch with an output nozzle diameter of 14 mm allowed the realization of a laminar flow regime. It is established that the laminar-turbulent transition is observed in the range of Reynolds numbers 400 - 900. The pattern of supersonic flow impinging a flat barrier - a substrate for placedat a distance of 85 mm from the plasma torch, is visualized.

scholarly journals APPLICATION OF PLASMA FLOWS IN SOFT TISSUE INFECTION

2017 ◽  
Vol 176 (1) ◽  
pp. 65-69 ◽  
Author(s):  
A. M. Shulutko ◽  
E. G. Osmanov ◽  
T. R. Gogokhiya ◽  
S. E. Khmyrova
Keyword(s):  
Soft Tissue ◽  
Soft Tissue Infection ◽  
Microbial Contamination ◽  
Local Therapy ◽  
Pain Syndrome ◽  
Tissue Infection ◽  
Control Group ◽  
Air Plasma ◽  
Plasma Flows ◽  
Results Of Treatment

The authors analyzed the results of treatment of 489 patients with surgical soft tissue infection at the period from 2004 to 2015. The argon and air-plasma flows in different regimes were applied in following local therapy during surgical d-bridement. The results obtained were compared with results of 280 patients who were treated using common me thod (control group). There was revealed that plasma processing of necrotic suppurative focus significantly accelerated wound cleansing and following reparation of post-necrotic wounds in 1.5-1,8 times regardless the severity and extent of covering tissue lesion. The method allowed doctors to decrease significantly the rate of microbial contamination of the focus and shorten the hospital stay. Similar trends were noted in terms of fever relief, pain syndrome and other important indices.

Spectroscopic Diagnostics of Air Plasma Flows around Carbon-Based Materials in an Arc-Heated Wind Tunnel

2020 ◽  
Vol 2020 (0) ◽  
pp. S19108
Author(s):  
Keisei TSUBOUCHI ◽  
Ryuta KOTO ◽  
Gouji YAMADA ◽  
Shouma HORIUCHI ◽  
Shunta OKAMURA ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Air Plasma ◽  
Plasma Flows ◽  
Spectroscopic Diagnostics ◽  
Carbon Based
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