Wyniki wyszukiwania - Biblioteka Nauki

1

R&D of ECR ion sources: news and perspectives

100%

Gammino S.

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2003

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tom Vol. 48,suppl.2

73-79

EN

The future accelerators need ion beams with higher charge state and higher current. This demand will be met by the “third generation Electron Cyclotron Resonance Ion Sources” (ECRIS) which will make use of improved plasma confinement by means of higher magnetic field and of higher microwave frequency, thus boosting the performance of nowadays ECRIS operating at the frequency of 14 and 18 GHz. The possibility to obtain confining fields exceeding 4 tesla, by means of special design of NbTi superconducting magnets, open the way to a new operational domain, at the typical frequencies of gyrotrons, above 28 GHz, with plasma densities never achieved before in ECRIS (1013 cm–3 and higher). The test of SERSE at 28 GHz, confirming the theoretical frame on which the third generation ECR sources design is based, will be presented; a synthetic review of the new generation ECRIS is carried out, with a particular emphasis on the design of the GyroSERSE source. Finally, the scheme of an innovative hybrid source will be outlined and a short description of the ECLISSE (Electron Cyclotron Resonance ion source Coupled to a Laser Ion Source for charge State Enhancement) experiment is hereinafter presented.

2

Photon Splitting in Strongly Magnetized Plasma

100%

Bulik T.

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1998

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tom Vol. 48, No. 4

695--710

EN

The process of photon splitting becomes allowed in the presence of strong magnetic field. We calculate the influence of magnetized plasma on the photon splitting absorption coefficient. We calculate the refraction coefficients and polarization vectors with the inclusion of the vacuum terms at an arbitrary value of the magnetic field, and then find photon splitting matrix element taking into account the terms that vanish in vacuum but may be nonzero in the presence of plasma. We find the photon splitting rate in plasma with the density typical for a neutron star star atmosphere and identify a region of the parameter space where the plasma effects are important.

3

Laser nuclear fusion: current status, challenges and prospect

80%

Badziak J.

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2012

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tom Vol. 60, nr 4

729-738

EN

In 2009, in Lawrence Livermore National Laboratory, USA, National Ignition Facility (NIF) - the largest thermonuclear fusion device ever made was launched. Its main part is a multi-beam laser whose energy in nanosecond pulse exceeds 1MJ (106 J). Its task is to compress DT fuel to the density over a few thousand times higher than that of solid-state DT and heat it to 100 millions of K degrees. In this case, the process of fuel compression and heating is realized in an indirect way - laser radiation (in UV range) is converted in the so-called hohlraum (1 cm cylinder with a spherical DT pellet inside) into very intense soft X radiation symmetrically illuminating DT pellet. For the first time ever, the fusion device's energetic parameters are sufficient for the achieving the ignition and self-sustained burn of thermonuclear fuel on a scale allowing for the generation of energy far bigger than that delivered to the fuel. The main purpose of the current experimental campaign on NIF is bringing about, within the next two-three years, a controlled thermonuclear 'big bang' in which the fusion energy will exceed the energy delivered by the laser at least ten times. The expected 'big bang' would be the culmination of fifty years of international efforts aiming at demonstrating both physical and technical feasibility of generating, in a controlled way, the energy from nuclear fusion in inertial confined plasma and would pave the way for practical realization of the laser-driven thermonuclear reactor. This paper briefly reviews the basic current concepts of laser fusion and main problems and challenges facing the research community dealing with this field. In particular, the conventional, central hot spot ignition approach to laser fusion is discussed together with the more recent ones - fast ignition, shock ignition and impact ignition fusion. The research projects directed towards building an experimental laser-driven thermonuclear reactor are presented as well.

4

Conversion of tetrachloromethane in large scale gliding discharge reactor

80%

Młotek M. , Reda E. , Krawczyk K.

Open Chemistry

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2015

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tom 13

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nr 1

EN

Gliding discharge plasma in a large scale reactor was used for decomposition of tetrachloromethane. The new power supply system based on a power inverter was used. The conversion of CCl4 was investigated in air at normal pressure. The reactor was made of a quartz-glass tube 60 mm in diameter and contained three converging electrodes 140 mm long. Effects of the initial CCl4 concentration, gas flow rate and discharge power on CCl4 conversion have been studied. The conversion of CCl4 was high in all cases reaching a maximum of 90%. The conversion of tetrachloromethane decreased with increasing initial concentration of CCl4 in the reaction mixture. Changing the gas flow rate from 1000 Nl h-1 to 1400 Nl h-1 decreased the conversion of tetrachloromethane.

5

Plasma recycling of chloroorganic wastes

80%

Jędrzejczyk T. , Kołaciński Z. , Koza D. , Raniszewski G. , Szymański Ł. , Wiak S.

Open Chemistry

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2015

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tom 13

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nr 1

EN

A high temperature of thermal plasma provides more efficient decomposition of the wastes in comparison to traditional combustion. Due to the high temperature and high density of energy in the plasma, the destruction rate is high, which determines a high efficiency waste decomposition. The main products of pyrolysis plasma chloroorganic compounds are pyrolysis gas and pyrolysis coke. In order to reduce carbon soot, the steam supported reaction was used. Application of plasma at a temperature range from 1000 to 1750 K enabled destruction of the chloroorganic compounds with a very good yield. Several degradation products were received , which were analyzed. In the research electric arc plasma was used in the process of pyrolysis chloroorganic waste utilization. The reactor with a rotating arc was applied. Selected chloroorganic compounds were selected as the model: chloromethane (CH3Cl), carbon tetrachloride (CCl4), chlorobenzene (C6H5Cl) and dichlorobiphenyl (PCB-C12H8Cl2). Based on the amount of the individual components, chloroorganic in the exhaust gases, and the amount introduced to the plasma decomposition, percentage yield was calculated. Research results indicated that decomposition efficiency was more than 99,8% with the exception of CCl4 pyrolysis, which in the exhaust had a content of 0.2% CCl4.

6

Role of a biased electrode in the production of highly charged ions using the DECRIS 14-3 ion source

80%

Leporis M. , Bogomolov S. , Efremov A. , Loginov V. , Mironov V.

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2003

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tom Vol. 48,suppl.2

89-92

EN

ECR ion sources are used for the production of highly charged ions in various accelerator facilities. In most of them biased electrodes are normally used to increase the ion yield. Physical processes in the plasma of an ion source are quite complicated and the role of a biased electrode is not clear. To investigate the effect of a biased electrode on the intensity of extracted highly charged ions, an axially movable electrode was placed into the plasma chamber of the DECRIS 14-3 ion source. It was found that the intensity of Ar ions depends on the position of the biased electrode and negative bias voltage. The optimal position of the biased electrode was found near the maximum of the magnetic field. Experiments with a pulsed biased electrode were also carried out. The influence of the negative pulse on the ion yield depends on the ion charge state.

7

Investigation of collisions between electrons and excited atoms of potassium, rubidium and caesium

80%

Pietruczuk A. , Stacewicz T. , Wilska M.

Optica Applicata

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2006

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tom Vol. 36, nr 4

s. 489--497

EN

Results of measurements of the rate constants for electron impact induced transitions between selected levels of potassium (4P–6P), rubidium (5P–7P) and caesium (6P–8P and 6P–9P) are presented. The experiment was done in helium plasma produced by electric discharge. The plasma was doped with the atoms of interest at a concentration of about 1011 cm–3. The alkali atoms were excited to resonance level by a laser pulse. The rate constants for the investigated transitions were determined by the analysis of atomic fluorescence. The electron temperature was measured using a double probe method.

8

UPLC-MS/MS analysis of SZJ-1207 in mouse plasma and brain and application in pharmacokinetic studies

80%

Qi D. , Sun Y. , Hu B. , An H. , Lin H. , Fang J. , Wei Y.

Acta Chromatographica

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2024

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tom Vol. 36, no. 2

99--105

EN

SZJ-1207 is an antidepressant natural product with a steroidal structure extracted from Stephanotis mucronata. It is a novel antidepressant candidate molecule and all its pharmacokinetic properties have not been reported. In this pharmacokinetic study in mice following oral administration, an accurate and sensitive UPLC-MS/MS method was established and evaluated to measure SZJ-1207 concentrations in mouse plasma and brain samples. The results provide information regarding the pharmacokinetics of SZJ-1207 as a potential antidepressant.

9

Magnetoacoustic heating and streaming in a plasma with finite electrical conductivity

80%

Perelomova A.

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2019

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tom Vol. 23, No 1

49--60

EN

Nonlinear effects of planar and quasi-planar magnetosound perturbations are discussed. Plasma is assumed to be an ideal gas with a finite electrical conductivity permeated by a magnetic field orthogonal to the trajectories of gas particles. The excitation of non-wavemodes in the field of intense magnetoacoustic perturbations,i.e., magnetoacoustic heating and streaming, is discussed. The analysis includes a derivation of instantaneous dynamic equations independent of the spectrum and periodicity of sound.

10

Studies of atmospheric - pressure microwave plasmas used for gas processing

80%

Mizeraczyk J. , Jasiński M. , Nowakowska H. , Dors M.

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tom Vol. 57, No. 2

241-247

EN

This paper concerns the atmospheric-pressure microwave plasmas and their applications, mainly for gas processing. Several types of atmospheric-pressure microwave sources (MPSs), i.e. surface-wave-sustained MPS, nozzle-type MPSs, nozzleless MPSs, plasma-sheet MPSs and microwave microplasma sources - MmPSs (antenna- and coaxial-line- -based) as well as their performance are presented. The presented experimental results on the optimization of selected MPSs are confronted with results of the modelling of the electromagnetic field in them. The paper deals also with the applications of MPSs for the processing of gases. Two types of the plasma gas processing were experimentally tested: decomposition of volatile organic compounds (VOCs) and reforming of VOCs (mainly methane) into hydrogen. Results of the laboratory experiments on the plasma processing of several highly-concentrated (up to 100%) VOCs, including freon-type refrigerants, in the waveguide-supplied MPSs showed that the microwave discharge plasma is capable of fully decomposing the VOCs at relatively low energy cost. The use of waveguide-supplied coaxial-line-based and metal-cylinder-based nozzleless MPSs to methane reforming into hydrogen turned out to be energetically efficient. These selected results show MPSs to be an attractive tool for gas processing, including the harmful gas decomposition and production of useful gases.

11

Multi - DBD actuator with floating inter - electrode for aerodynamic control

80%

Berendt A. , Podliński J. , Mizeraczyk J.

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tom Vol. 57, No. 2

249-252

EN

In this paper the use of a floating inter-electrode in a multi-DBD (dielectric barrier discharge) plasma actuator is described. The multi-DBD plasma actuators with floating inter-electrodes were investigated to get a longer DBD on a dielectric surface and to maximise generated net airflow. Our actuator was used to control the boundary layer flow separation around NACA0012 airfoil model. The results of our investigations suggests that multi-DBD actuators with floating inter-electrodes can be attractive for aerodynamic purposes.

12

Changes in Plasma Potassium During Graded Aerobic Exercise and Two Hours of Recovery

80%

Tenan M. , McMurray R. , Hosick P. , Hackney A.

Journal of Human Kinetics

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2010

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tom 26

51-55

EN

Plasma potassium increases with exercise intensity. Subjects (n=8) were monitored for changes in plasma potassium while exercising at progressively increasing steady-state intensities and for two hours of recovery. Plasma potassium was significantly increased at 100% of VO2peak compared to 20% and 40% (p<0.01). Plasma potassium at 60 and 120 minutes of recovery from exercise was significantly higher than 6 minutes post exercise (p<0.015). These results support the supposition that high-intensity exercise may lead to hyperkalemia, and also indicates that increases in [K+] occur up to two hours after the cessation of exercise, a newly reported phenomenon. Although, high levels of plasma potassium are known to cause cardiac abnormalities and related events, exercise induced changes in normal healthy adults are not currently believed to have clinical implications

13

Plastic plasma interaction with plasmas with growing atomic number

80%

Kasperczuk A. , Pisarczyk T. , Chodukowski T. , Kalinowska Z. , Gus’kov S. , Demchenko N. , Ullschmied J. , Krousky E. , Pfeifer M. , Skala J. , Klir D. , Kravarik J. , Kubes P. , Cikhardt J. , Rezac K. , Pisarczyk P.

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tom 11

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nr 5

575-579

EN

This paper describes the investigation of the influence of target material atomic number (Z) on the laser-produced plasma pressure. For this reason, several target materials representing a wide range of atomic numbers (Z = 3.5 - 73), i.e. plastic (CH), Al, Cu, Ag, and Ta, were used. The results presented show that the plasma pressure decreases with growing atomic number but in a limited range of Z only. For higher Z, starting approximately from Z = 47 (Ag), the plasma pressure becomes constant, as confirmed by interferometric measurements and x-ray plasma imaging.

14

Estimate of antioxidant capacity and lipid peroxidation in plasma of healthy subjects

80%

Gorąca A. , Skibska B.

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nr 1

23-34

EN

Serum contains various antioxidant molecules that may provide important protection against free radical attack. The aim of this work was to assess the total antioxidant capacity of plasma and a marker of lipid per oxidation [(thiobarbituric acid-reactive substances (TBARS)] in plasma of healthy smoking and non-smoking young and elderly subjects. In addition, we investigated plasma concentrations of α-tocopherol, β-carotene, and ascorbic acid. In in vitro experiments, the effects of exogenous compounds (ascorbic acid, uric acid, Trolox) on total ferric-reducing activity of plasma (FRAP) were also tested. We demonstrated that total antioxidant capacity of plasma obtained from healthy non-smoking young subjects was significantly higher than plasma antioxidant capacity of smoking elderly subjects. The concentration of TBARS in young non-smoking volunteers was lower than that in young smokers. The concentration of TBARS in elderly non-smoking volunteers was lower than in elderly smokers. Plasma concentrations of alpha-tocopherol, beta-carotene and ascorbic acid were significantly lower in elderly smoker than in elderly non-smokers of the same age. No difference in the plasma levels of alpha-tocopherol, beta-carotene and ascorbic acid were found in 22-year-old smoking and non-smoking subjects. In vitro addition of ascorbic acid, uric acid, or Trolox to plasma samples significantly increased their total antioxidant capacity. Decrease of FRAP values and increase of TBARS concentrations is a significant physiologic condition of the aging process. Supplementation of antioxidants could be useful for the enhancement of antioxidant screen in plasma.

15

Influence of space charged particles on satellite optical communication system

80%

Hou R. , Zhao S. , Xu J. , Wu J. , Li Y. , Zhan S. , Shi L. , Fang S.

Optica Applicata

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2009

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tom Vol. 39, nr 2

251-265

EN

Although research of satellite optical communication system has been carried out for many years, there is scarce literature to comprehensively analyze the influence of space environment on satellite optical communication system. Different kinds of particles and fields exist in the space environment, including high energy charged particles, solar radiation, plasma environment, space fragment, etc. The Influence of space charged particles on satellite optical communication system was investigated in detail, which mainly related to single event upset (SEU), total dose effect and plasma environment. For SEU analysis the relation between single proton upset rate and satellite orbit was analyzed in detail. The reliability index of equipment based on SEU was proposed, the numerical calculation results have proved that the SEU effect was relatively less and corresponded to higher reliability of SRAM/MOS equipment under lower orbit altitude and inclination. For plasma environment analysis there is no obvious influence of plasma on laser signal transmission. But charging and discharging processes on satellite surface would lead to the malfunction of satellite communication system. The influence of charged particles and its related plasma on satellite optical communication system was investigated, which would be helpful for the design and the improvement of performance of satellite optical communication system.

16

Plasma parameters in a surface wave discharge in nitrogen at atmospheric pressure

80%

Nowakowska H. , Stańco J. , Zakrzewski Z.

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tom nr 112

125-137

EN

Spatial distributions of plasma parameters are calculated for a surface wave discharge sustained in nitrogen at atmospheric pressure. A macroscopic model, applicable to an axially uniform two-temperature plasma, yields the radial distributions of the parameters. The axial distributions are determinated from relations based on the approximation of local axial uniformity, which is valid provided the attenuation of the surface wave is weak. In the approximation adopted, the plasma parameters in any cross section of the discharge depend under given conditions solely on L, the power lost per unit length of the plasma column. Calculations made for a 2.45 GHz discharge in a capillary tube show an almost linear decrease of L and of the electron density towards the end of the discharge. The electron temperature for nitrogen is lower than for argon under similar discharge conditions. In nitrogen the electron density is about one order of magnitude lower and the gas temperature is much closer to the electron temperature than for argon. This may be explained by the presence of vibrational and rotational excitation and relaxation channels, which facilitate redistribution of the energy deposited in the discharge.

17

Plazmowe szczepienie soli sodowej kwasu 4-styrenosulfonowego na polisulfonie

80%

Gancarz I. , Poźniak G. , Bryjak M.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2001

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tom Vol. 50, nr 23

388-391

PL

Na powierzchni ultrafiltracyjnych membran sulfonowych modyfikowanych plazmą mikrofalową argonu szczepiono łańcuchy soli sodowej kwasu 4-styrenosulfonowego. Napięcie powierzchniowe polisulfonu po plazmie argonu znacznie się zwiększyło osiągając wartość 60 mN/m, przy czym udział składowej polarnej przekroczył 50%. Zwiększeniu uległ także średni wymiar porów membrany i strumień hydrauliczny wody. Po reakcji szczepienia napięcie powierzchniowe jest znacznie mniejsze (40-50mN/m), rozrzut wielkości porów ulega poszerzeniu i przesunięciu w kierunku mniejszych rozmiarów a strumień hydrauliczny drastycznie maleje. Modyfikowane membrany wykazują doskonałe właściwości filtracyjne, szczególnie w środowisku zasadowym.

EN

Argon microwave plasma was used to graft the chains of sodium salt of 4-styrenesulfonic acid onto surface of polysulfone membranes. After argon plasma surface become more hydrophylic - surface tension reaches - 60 mN/m with moree than 50% of polar component. Average pore size and water flux increases. Grafting gave in result lower surface tension (40-50 mN/m), wider pore size distribution and lower water flux. Modified membranes showed however excellent filtration performance especially in the basic environment.

18

Opyt ispol'zovania plazmenno-toplivyh system na pyleugol'nyh teplovyh elektrostanciah

80%

Karpenko E. I. , Messerle V. E. , Ustimenko A. B.

Prace Instytutu Nafty i Gazu

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2009

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tom nr 162

159-163

EN

This paper presents short review of solid fuels ignition plasma technology development, technical and economical characteristics of plasma-fuel systems, schemes of their mounting on different pulverized coal boilers and some results of their application at pulverized coal firing thermal power plants of Russia, Kazakhstan, Ukraine, China, Slovakia, Mongolia, Korea, Yugoslavia. Plasma-fuel systems eliminate necessity of expensive natural gas and fuel oil use for boilers starting up and pulverized coal flame stabilization. They ensure stable ignition of pulverized coal flame, decrease of unburned carbon and NOx emission.

19

Plazmennaa tehnologia effektivnoj gazifikacii tverdyh topliv

80%

Messerle V. E. , Ustimenko A. B.

Prace Instytutu Nafty i Gazu

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2009

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tom nr 162

153-158

EN

This paper presents the results of numerical and experimental study of plasma steam and air gasification of solid fuels at an arc reactor. Calculations were fulfilled using numerical code TERRA for thermodynamic computation. The numerical results were compared with experimental data. Kazakhstan bituminous coal of 40% ash content and Canadian petrocoke of 3% ash content were investigated. As a result of plasma gasification of these solid fuels high quality synthesis gas was produced. Composition of H2 + CO varied from 43.3% at air gasification to 97.4% at steam gasification of the solid fuels.

20

Localized plasma polarimetry based on the phenomenon of normal mode conversion

80%

Kravtsov Y. A. , Bieg B.

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tom Vol. 56, No. 2

171-174

EN

A new geometry of microwave polarimetric measurements is presented, which realizes a localized plasma polarimetry based on the phenomenon of electromagnetic mode conversion. Such a conversion takes place in the tokamak plasma, in the vicinity of the point where the microwave beam is orthogonal to one of the helical magnetic lines. In distinction to the traditional plasma polarimetry, which deals with the line averaged plasma parameters, the new methodology allows for a measurement of the local values of plasma parameters near the point of orthogonality. This methodology was shown to be very efficient in studies of the solar radio emission and polarization properties of radio waves passing through the Earth ionosphere. In the following the theory of electromagnetic mode conversion is described and conditions of its applicability are analyzed. It is shown that localized polarimetric measurements of plasma parameters in the geometry of the international thermonuclear experimental reactor (ITER) device would require very high electron densities Ne, exceeding 1017 cm–3, i.e. thousand times higher than those envisaged in the ITER project.