WorldWideScience

Sample records for plasma parameters achieved

  1. Measurement of plasma parameters

    International Nuclear Information System (INIS)

    1999-01-01

    The physics issues of the measurements of the plasma properties necessary to provide both the control and science data for achieving the goals of the ITER device are discussed. The assessment of the requirements for these measurements is first discussed, together with priorities that relate to the experimental program. Subsequently, some of the proposed measurement techniques, the plasma diagnostics, are described with particular emphasis on their implementation on ITER and their capability to meet the requirements. A judgement on the present status of the diagnostic program on ITER is provided with some indication of the research and development program necessary to demonstrate viability of techniques or their implementation. (author)

  2. Fast determination of plasma parameters

    International Nuclear Information System (INIS)

    Wijnands, T.J.; Parlange, F.; Joffrin, E.

    1995-01-01

    Fast analysis of diagnostic signals of a tokamak discharge is demonstrated by using 4 fundamentally different techniques. A comparison between Function Parametrization (FP), Canonical Correlation Analysis (CCA) and a particular Neural Network (NN) configuration known as the Multi Layer Perceptron (MLP) is carried out, thereby taking a unique linear model based on a Singular Value Decomposition (SVD) as a reference. The various techniques provide all functional representations of characteristic plasma parameters in terms of the values of the measurements and are based on an analysis of a large, experimentally achieved database. A brief mathematical description of the various techniques is given, followed by two particular applications to Tore Supra diagnostic data. The first problem is concerned with the identification of the plasma boundary parameters using the poloidal field and differential poloidal flux measurements. A second application involves the interpretation of line integrated data from the multichannel interfero-polarimeter to obtain the central value of the safety factor. (author) 4 refs.; 3 figs

  3. Plasma diagnostics discharge parameters and chemistry

    CERN Document Server

    Auciello, Orlando

    1989-01-01

    Plasma Diagnostics, Volume 1: Discharge Parameters and Chemistry covers seven chapters on the important diagnostic techniques for plasmas and details their use in particular applications. The book discusses optical diagnostic techniques for low pressure plasmas and plasma processing; plasma diagnostics for electrical discharge light sources; as well as Langmuir probes. The text also describes the mass spectroscopy of plasmas, microwave diagnostics, paramagnetic resonance diagnostics, and diagnostics in thermal plasma processing. Electrical engineers, nuclear engineers, microwave engineers, che

  4. Plasma Medicine: Current Achievements and Future Prospects

    Science.gov (United States)

    Laroussi, Mounir

    2012-10-01

    Research on the biomedical applications of low temperature plasmas started with small scale experiments that were simply aimed at discovering what happens to biological cells when exposed to the chemically rich environment of plasma. These early experiments took place in the mid to late 1990s. As interest in this multidisciplinary field dramatically rose, various engineering and physics groups collaborated with biologists and medical experts to investigate the use of plasma technology as a basis for innovative medical approaches to cure various diseases. However, many questions concerning the fundamental mechanisms involved in cell-plasma interaction remained unanswered. As a result various workshops were organized to gather the diverse research community in the field of plasma medicine in order to have a fruitful exchange of ideas regarding the scientific challenges that needed to be surmounted to advance and expand the field's knowledge base. The present GEC workshop continues this important tradition of scientific cooperation since there is still a significant lack of understanding of many of the biochemical and molecular pathways that come into play when biological cells are exposed to plasmas. In this talk, first background information on the various plasma devices developed in our institute will be presented. This will be followed by a summary of our work on the effects of plasmas on prokaryotic and eukaryotic cells. The talk will be concluded by presenting our vision of the future of the field and an outline of the main challenges that need to be overcome if practical medical applications are to be achieved.

  5. Sensitivity of transient synchrotron radiation to tokamak plasma parameters

    International Nuclear Information System (INIS)

    Fisch, N.J.; Kritz, A.H.

    1988-12-01

    Synchrotron radiation from a hot plasma can inform on certain plasma parameters. The dependence on plasma parameters is particularly sensitive for the transient radiation response to a brief, deliberate, perturbation of hot plasma electrons. We investigate how such a radiation response can be used to diagnose a variety of plasma parameters in a tokamak. 18 refs., 13 figs

  6. Effect of Equilibrium Flow on Plasma Parameters

    International Nuclear Information System (INIS)

    Mukhopadhyay, S.; Lahiri, S.; Sakanaka, P.H.; Dasgupta, B.

    2003-01-01

    The transition to high confinement modes have been identified with the occurrence of strong shear flow near the plasma boundary. Plasma flow has also been associated with various instabilities, heating and other physical processes. As a result, it has become very important to study the effect of such flows on various plasma parameters. In this paper, we present the numerical solution of plasma equilibrium with incompressible toroidal and poloidal flows in several magnetic confinement configurations including tokamaks. The code, which was reported in the last conference, has been used to solve the problem in both circular and D-shaped devices. A parametric study on the generation of shear flow due to radial electric fields has been carried out. Through this study, it has been possible to generate plasma equilibria having sharp pressure gradients which are remarkably close to those reported in various H-mode experiments. The effects of flow on reverse shear equilibria and on the position of the magnetic axis has been studied. Finally, a detailed study has been carried out to understand the effect of flows on important plasma parameters, such as the poloidal flux function, β, energy confinement time

  7. Coaxial discharge plasma parameters and radiation emission

    International Nuclear Information System (INIS)

    Solimen, H.M.

    1993-01-01

    Results are reported for experiments carried out on a Mather type coaxial discharge plasma device. Experimental measurements of the electron temperature and density for the plasma propagated from the coaxial discharge are determined by using a biased double electric probe. The experimental results illustrated that , there are two groups of the plasma in the ejected plasma bulk, at 9 cm from the muzzle axis, the plasma reached the probe at 20 μsec from the start of discharge. The first group has electron temperature and density 27 eV and 3 x 10 14 cm -3 respectively,while The second group has 25 eV and 3 x 10 14 cm -3 respectively. The decay rate of the electron temperature and density of each group is presented. The plasma radiation spectrum is detected by a dielectric filter at 3500 A degree or 6100 A degree . The experimental measurements showed that, without or with dielectric filters, the visible radiation consists from two pulses with different magnitudes within the same half cycle of discharge. The time resolution of the soft x-ray is achieved by means of scintillator detector. The detected x-ray pulse during the first half cycle of discharge had a double peaks with different structures. All the experimental results present in this paper showed that the plasma bulk propagated in the expansion chamber, consists of two-groups. 6 fig

  8. Characterization of hot dense plasma with plasma parameters

    Science.gov (United States)

    Singh, Narendra; Goyal, Arun; Chaurasia, S.

    2018-05-01

    Characterization of hot dense plasma (HDP) with its parameters temperature, electron density, skin depth, plasma frequency is demonstrated in this work. The dependence of HDP parameters on temperature and electron density is discussed. The ratio of the intensities of spectral lines within HDP is calculated as a function of electron temperature. The condition of weakly coupled for HDP is verified by calculating coupling constant. Additionally, atomic data such as transition wavelength, excitation energies, line strength, etc. are obtained for Be-like ions on the basis of MCDHF method. In atomic data calculations configuration interaction and relativistic effects QED and Breit corrections are newly included for HDP characterization and this is first result of HDP parameters from extreme ultraviolet (EUV) radiations.

  9. A lumped parameter model of plasma focus

    International Nuclear Information System (INIS)

    Gonzalez, Jose H.; Florido, Pablo C.; Bruzzone, H.; Clausse, Alejandro

    1999-01-01

    A lumped parameter model to estimate neutron emission of a plasma focus (PF) device is developed. The dynamic of the current sheet is calculated using a snowplow model, and the neutron production with the thermal fusion cross section for a deuterium filling gas. The results were contrasted as a function of the filling pressure with experimental measurements of a 3.68 KJ Mather-type PF. (author)

  10. Simultaneous measurement of 3 fluctuating plasma parameters

    International Nuclear Information System (INIS)

    Carlson, A.; Giannone, L.

    1991-01-01

    Langmuir triple probes can provide simultaneous measurements of n e , T e and V pl with good temporal and spatial resolution, and therefore are especially suited to detailed investigations of plasma turbulence in the scrape-off-layer. Unfortunately, the finite tip separation coupled with the fluctuating gradients prevents a simple interpretation of the results. We have developed a method using, essentially, two or more triple probes, which allows a good estimate of the three plasma parameters and their spatial derivatives at each point of time (assuming tip separation is much less than correlation length and dimensionless fluctuation levels are much less than unity). In particular, we can unambiguously measure the temperature fluctuations and the turbulent particle and heat flux. (author) 1 fig

  11. Simultaneous measurement of 3 fluctuating plasma parameters

    International Nuclear Information System (INIS)

    Carlson, A.; Giannone, L.

    1991-01-01

    Langmuir triple probes can provide simultaneous measurements of n e , T e , and V pl with good temporal and spatial resolution, and therefore are especially suited to detailed investigations of plasma turbulence in the scrape-off-layer. Unfortunately, the finite tip separation coupled with the fluctuating gradients prevents a simple interpretation of the results. We have developed a method using, essentially, two or more triple probes, which allows a good estimate of the three plasma parameters and their spatial derivatives at each point of time (assuming tip separation is much less than correlation length and dimensionless fluctuation levels are much less than unity). In particular, we can unambiguously measure the temperature fluctuations and the turbulent particle and heat flux. (orig.)

  12. Simultaneous measurement of 3 fluctuating plasma parameters

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, A; Giannone, L. (Max-Planck-Institut fuer Plasmaphysik, Garching (Germany))

    1991-01-01

    Langmuir triple probes can provide simultaneous measurements of n[sub e], T[sub e] and V[sub pl] with good temporal and spatial resolution, and therefore are especially suited to detailed investigations of plasma turbulence in the scrape-off-layer. Unfortunately, the finite tip separation coupled with the fluctuating gradients prevents a simple interpretation of the results. We have developed a method using, essentially, two or more triple probes, which allows a good estimate of the three plasma parameters and their spatial derivatives at each point of time (assuming tip separation is much less than correlation length and dimensionless fluctuation levels are much less than unity). In particular, we can unambiguously measure the temperature fluctuations and the turbulent particle and heat flux. (author) 1 fig.

  13. Investigation of helium plasma stream parameters in experiments on surface modification

    International Nuclear Information System (INIS)

    Bandura, A.N.; Byrka, O.V.; Chebotarev, V.V.; Garkusha, I.E.; Tsarenko, A.V. and eds.

    2005-01-01

    The main objection of this study is adjustment of plasma treatment regimes for different materials that allows achieving optimal thickness of modified layer with simultaneously minimal value of surface roughness. With use of optical spectroscopy, detailed information about the basic plasma parameters - electron density, electron and ion temperatures, plasma stream duration and velocity, was obtained. Integrated spectra of plasma radiation were analyzed. The majority of helium and impurity spectral lines were investigated on a subject of Stark broadening. Plasma pressure and energy density values measured with piezodetectors and calorimeters are in good agreement with plasma parameters obtained by optical techniques

  14. Extreme hydrogen plasma densities achieved in a linear plasma generator

    NARCIS (Netherlands)

    Rooij, van G.J.; Veremiyenko, V.P.; Goedheer, W.J.; Groot, de B.; Kleyn, A.W.; Smeets, P.H.M.; Versloot, T.W.; Whyte, D.G.; Engeln, R.A.H.; Schram, D.C.; Lopes Cardozo, N.J.

    2007-01-01

    A magnetized hydrogen plasma beam was generated with a cascaded arc, expanding in a vacuum vessel at an axial magnetic field of up to 1.6 T. Its characteristics were measured at a distance of 4 cm from the nozzle: up to a 2 cm beam diameter, 7.5×1020 m-3 electron density, ~2 eV electron and ion

  15. Stationary neoclassical profiles of plasma parameters in stellarators

    International Nuclear Information System (INIS)

    Danilkin, I.S.; Mineev, A.B.

    1991-01-01

    Peculiarities of neoclassical model of heat and particle transfer, occuring by calculations of plasma stationary profile parameters in stellarators are considered. The main peculiarity out of all consists in ineadequate compatibility with real physical conditions on the boundary, requiring application of supplementary 'anomalous' transfer or special (but technically possible) adjustment of particle and heat sources to achieve solution in form of 'correct' monotonically sloping profile. It is stated, that neoclassical theory does not provide for well-known ambiguity of solutions for ambipolar electrical field by search of monotonous stationary profiles supported by outside sources

  16. DAQ system for low density plasma parameters measurement

    International Nuclear Information System (INIS)

    Joshi, Rashmi S.; Gupta, Suryakant B.

    2015-01-01

    In various cases where low density plasmas (number density ranges from 1E4 to 1E6 cm -3 ) exist for example, basic plasma studies or LEO space environment measurement of plasma parameters becomes very critical. Conventional tip (cylindrical) Langmuir probes often result into unstable measurements in such lower density plasma. Due to larger surface area, a spherical Langmuir probe is used to measure such lower plasma densities. Applying a sweep voltage signal to the probe and measuring current values corresponding to these voltages gives V-I characteristics of plasma which can be plotted on a digital storage oscilloscope. This plot is analyzed for calculating various plasma parameters. The aim of this paper is to measure plasma parameters using a spherical Langmuir probe and indigenously developed DAQ system. DAQ system consists of Keithley source-meter and a host system connected by a GPIB interface. An online plasma parameter diagnostic system is developed for measuring plasma properties for non-thermal plasma in vacuum. An algorithm is developed using LabVIEW platform. V-I characteristics of plasma are plotted with respect to different filament current values and different locations of Langmuir probe with reference to plasma source. V-I characteristics is also plotted for forward and reverse voltage sweep generated programmatically from the source meter. (author)

  17. Hot plasma parameters in Neptune's magnetosphere

    International Nuclear Information System (INIS)

    Krimigis, S.M.; Mauk, B.H.; Cheng, A.F.; Keath, E.P.; Kane, M.; Armstrong, T.P.; Gloeckler, G.; Lanzerotti, L.J.

    1990-01-01

    Energy spectra of energetic protons and electrons (E p approx-gt 28 keV, E e approx-gt 22 keV, respectively) obtained with the Low Energy Charged Particle (LECP) instrument during the Voyager 2 encounter with Neptune on August 24-25, 1989 are presented. The proton spectral form was a power law (dj/dE = KE -γ ), outside the orbit of Triton (∼14.3 R N ); inside that distance, it was found to be a hot (kT ≅ 60 keV) Maxwellian distribution. Such distributions, observed in other planets as well, have yet to be explained theoretically. Similarly, the electron spectral form changed from a simple power law outside Triton to a two-slope power law with a high energy tail inside. Intensity and spectral features in both proton and electron fluxes were identified in association with the crossings of the Triton and 1989 N1 L-shells, but these features do not occur simultaneously in both species. Such signatures were manifested by relative peaks in both kT and γ spectral indices. Peak proton pressures of ∼2x10 -9 dynes cm -2 , and β ∼ 0.2 were measured at successive magnetic equatorial crossings, both inbound and outbound. These parameters show Neptune's magnetosphere to be relatively undistorted by hot plasma loading, similar to that of Uranus and unlike those of Saturn and Jupiter. Trapped electron fluxes at Neptune, as at Uranus, exceed the whistler mode stably trapped flux limit. Whistler-induced pitch angle scattering of energetic electrons in the radiation belts can yield a precipitating energy flux sufficient to drive Neptune's aurora

  18. Plasma spray technology process parameters and applications

    International Nuclear Information System (INIS)

    Sreekumar, K.P.; Karthikeyan, J.; Ananthapadmanabhan, P.V.; Venkatramani, N.; Chatterjee, U.K.

    1991-01-01

    The current trend in the structural design philosophy is based on the use of substrate with the necessary mechanical properties and a thin coating to exhibit surface properties. Plasma spray process is a versatile surface coating technique which finds extensive application in meeting advance technologies. This report describes the plasma spray technique and its use in developing coatings for various applications. The spray system is desribed in detail including the different variables such as power input to the torch, gas flow rate, powder properties, powder injection, etc. and their interrelation in deciding the quality of the coating. A brief write-up on the various plasma spray coatings developed for different applications is also included. (author). 15 refs., 15 figs., 2 tabs

  19. Measurement of performance parameters of plasma source for plasma opening switch on Qiangguang-Ⅰ generator

    International Nuclear Information System (INIS)

    Luo Weixi; Zeng Zhengzhong; Lei Tianshi; Wang Liangping; Hu Yixiang; Sun Tieping; Huang Tao

    2012-01-01

    The plasma source (cable guns) of the plasma opening switch (POS) on Qiangguang Ⅰ generator was chosen as the study object. The plasma source performance was investigated by using charge collectors. Experimental results show that the plasma ejection density is positively correlated with the structural parameter, the distance between gun core tip and muzzle plane, and the plasma ejection velocity is negatively correlated with the parameter. The increasing rate of plasma ejection density is less than that of drive current. As far as a plasma source with tens of cable plasma guns is concerned, the influence of single cable gun's discharge dispersancy on plasma uniformity is little. Analysis of uncertainty shows that the uncertainty of measurement can be reduced by increasing the number of experiments and averaging the results. The combined standard uncertainty of plasma ejection density is less than 10%. (authors)

  20. Influence of plasma parameters in pulsed plasma gun on modification processes in exposed structural materials

    International Nuclear Information System (INIS)

    Byrka, O.V.; Bandura, A.N.; Chebotarev, V.V.; Garkusha, I.E.; Garkusha, V.V.; Makhai, V.A.; Tereshin, V.I.

    2011-01-01

    This paper is focused on investigation of helium, nitrogen and krypton plasma streams generated by pulsed plasma gun (PPA). The main objection of this study is adjustment of plasma treatment regimes for different materials that allows achieving optimal thickness of modified layer with simultaneously minimal value of surface roughness. Features of materials alloying from gas and metallic plasma as a result of the plasma ions mixing with the steel substrate in liquid phase are discussed also.

  1. Plasma jet source parameter optimisation and experiments on injection into Globus-M spherical tokamak

    International Nuclear Information System (INIS)

    Gusev, V.K.; Petrov, Yu.V.; Sakharov, N.V.; Semenov, A.A.; Voronin, A.V.

    2005-01-01

    Results of theoretical and experimental research on the plasma sources and injection of plasma and gas jet produced by the modified source into tokamak Globus-M are presented. An experimental test stand was developed for investigation of intense plasma jet generation. Optimisation of pulsed coaxial accelerator parameters by means of analytical calculations is performed with the aim of achieving the highest flow velocity at limited coaxial electrode length and discharge current. The optimal parameters of power supply to generate a plasma jet with minimal impurity contamination and maximum flow velocity were determined. A comparison of experimental and calculation results is made. Plasma jet parameters are measured, such as: impurity species content, pressure distribution across the jet, flow velocity, plasma density, etc. Experiments on the interaction of a higher kinetic energy plasma jet with the magnetic field and plasma of the Globus-M tokamak were performed. Experimental results on plasma and gas jet injection into different Globus-M discharge phases are presented and discussed. Results are presented on the investigation of plasma jet injection as the source for discharge breakdown, plasma current startup and initial density rise. (author)

  2. On the distribution of plasma parameters in RF glow discharge

    International Nuclear Information System (INIS)

    Ning Cheng; Liu Zuli; Liu Donghui; Han Caiyuan.

    1993-01-01

    A self-consistent numerical model based on the two-fluid equations for describing the transport of charged particles in the RF glow discharge is presented. For a plasma generator filled with low-pressure air and parallel-plate electrodes, the model is numerical solved. The space-time distribution of parameters and the spatial distribution of some time-averaged parameters in plasma, which show the physical picture of the RF glow discharge, are obtained

  3. Limiting parameters of the plasma opening switch

    International Nuclear Information System (INIS)

    Dolgachev, G.I.; Ushakov, A.G.

    2001-01-01

    Implementing programs for nuclear fusion research and X-ray generation requires the creation of superpower generators based on plasma opening switches (POSs) capable of commutating currents as high as several tens of megaamperes at output voltages of up to 5 MV and higher. The physical mechanisms limiting the POS voltage are investigated. It is shown that, as the generator voltage U g increases, the voltage multiplication factor k U POS /U g (where U POS is the POS voltage) decreases. An explanation for such a dependence is proposed, and the maximum value of the POS voltage is estimated. A POS design that enables operating in the above current and voltage ranges is considered. The design is based on applying an external magnetic field to the POS interelectrode gap, increasing the initial generator voltage, and decreasing the linear (along the perimeter of the outer electrode) density of the charge passing through the POS during the conduction phase

  4. Dependence of plasma characteristics on dc magnetron sputter parameters

    International Nuclear Information System (INIS)

    Wu, S.Z.

    2005-01-01

    Plasma discharge characteristics of a dc magnetron system were measured by a single Langmuir probe at the center axis of the dual-side process chamber. Plasma potential, floating potential, electron and ion densities, and electron temperature were extracted with varying dc power and gas pressure during sputter deposition of a metal target; strong correlations were shown between these plasma parameters and the sputter parameters. The electron density was controlled mostly by secondary electron generation in constant power mode, while plasma potential reflects the confinement space variation due to change of discharge voltage. When discharge pressure was varied, plasma density increases with the increased amount of free stock molecules, while electron temperature inversely decreased, due to energy-loss collision events. In low-pressure discharges, the electron energy distribution function measurements show more distinctive bi-Maxwellian distribution, with the fast electron temperature gradually decreases with increased gas pressure

  5. Plasma parameters in the COMPASS divertor during Ohmic plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrova, M. [Institute of Plasma Physics, Academy of Sciences of the Czech Republic v.v.i., Prague (Czech Republic); Emil Djakov Institute of Electronics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Dejarnac, R.; Stoeckel, J.; Havlicek, J.; Janky, F.; Panek, R. [Institute of Plasma Physics, Academy of Sciences of the Czech Republic v.v.i., Prague (Czech Republic); Popov, Ts.K. [Faculty of Physics, St. Kl. Ohridski University of Sofia (Bulgaria); Ivanova, P.; Vasileva, E. [Emil Djakov Institute of Electronics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Kovacic, J. [Jozef Stefan Institute, Ljubljana (Slovenia)

    2014-04-15

    This paper reports on probe measurements of the electron energy distribution function and plasma potential in the divertor region of the COMPASS tokamak during D-shaped plasmas. The probe data have been processed using the novel first-derivative technique. A comparison with the results obtained by processing the same data with the classical probe technique, which assumes Maxwellian electron energy distribution functions is presented and discussed. In the vicinity of the inner and outer strike points of the divertor the electron energy distribution function can be approximated by a bi-Maxwellian, with a dominating low-energy electron population (4-7 eV) and a minority of higher energy electrons (12-25 eV). In the private flux region between the two strike points the electron energy distribution function is found to be Maxwellian with temperatures in the range of 7-10 eV. The comparative analysis using both techniques has allowed a better insight into the underlying physical processes at the divertor region of the COMPASS tokamak. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. New achievements in the EAST plasma control system

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Q.P., E-mail: qpyuan@ipp.ac.c [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Xiao, B.J. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Penaflor, B.G.; Piglowski, D.A. [General Atomics, DIII-D National Fusion Facility, San Diego, CA (United States); Liu, L.Z. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Johnson, R.D.; Walker, M.L.; Humphreys, D.A. [General Atomics, DIII-D National Fusion Facility, San Diego, CA (United States)

    2010-07-15

    In order to realize the low latency and distortion-free signal transmission between the plasma control system (PCS) and servo systems, the digital output structure configured with reflective memory board (RFM) was adopted in EAST PCS. And the enhanced performances are reported. Another achievement made in the latest EAST PCS was the implementation of density control algorithm, which controlled the line average density in either voltage or width modulation mode. The new integrated algorithm improved the precision of density calculation and control performance greatly. The details and experiment results are presented in this paper.

  7. Investigation of the helicon discharge plasma parameters in a hybrid RF plasma system

    International Nuclear Information System (INIS)

    Aleksandrov, A. F.; Petrov, A. K.; Vavilin, K. V.; Kralkina, E. A.; Neklyudova, P. A.; Nikonov, A. M.; Pavlov, V. B.; Ayrapetov, A. A.; Odinokov, V. V.; Sologub, V. A.; Pavlov, G. Ya.

    2016-01-01

    Results of an experimental study of the helicon discharge plasma parameters in a prototype of a hybrid RF plasma system equipped with a solenoidal antenna are described. It is shown that an increase in the external magnetic field leads to the formation of a plasma column and a shift of the maximum ion current along the discharge axis toward the bottom flange of the system. The shape of the plasma column can be controlled via varying the configuration of the magnetic field.

  8. Investigation of the helicon discharge plasma parameters in a hybrid RF plasma system

    Energy Technology Data Exchange (ETDEWEB)

    Aleksandrov, A. F.; Petrov, A. K., E-mail: alpetrov57@gmail.com; Vavilin, K. V.; Kralkina, E. A.; Neklyudova, P. A.; Nikonov, A. M.; Pavlov, V. B. [Moscow State University, Faculty of Physics (Russian Federation); Ayrapetov, A. A.; Odinokov, V. V.; Sologub, V. A.; Pavlov, G. Ya. [Research Institute of Precision Engineering (Russian Federation)

    2016-03-15

    Results of an experimental study of the helicon discharge plasma parameters in a prototype of a hybrid RF plasma system equipped with a solenoidal antenna are described. It is shown that an increase in the external magnetic field leads to the formation of a plasma column and a shift of the maximum ion current along the discharge axis toward the bottom flange of the system. The shape of the plasma column can be controlled via varying the configuration of the magnetic field.

  9. Fast determination of plasma parameters through function parametrization

    International Nuclear Information System (INIS)

    Braams, B.J.; Jilge, W.; Lackner, K.

    1985-09-01

    The method of function parametrization, developed by H. Wind for fast data evaluation in high energy physics, is demonstrated in the context of controlled fusion research. This method relies on a statistical analysis of a large data base of simulated experiments in order to obtain a functional representation for intrinsic physical parameters of a system in terms of the values of the measurements. Rapid determination of characteristic equilibrium parameters of a tokamak discharge is shown to be a particularly indicated application. The method is employed on the ASDEX experiment to determine the following parameters of the plasma: position of the magnetic axis, geometric center, and current center; minor radius, elongation, and area of the plasma column; a normalized safety factor at the plasma boundary; the Shafranov parameter βsub(p)+lsub(i)/2; the flux difference between the plasma boundary and an external reference value; the position of the lower and upper saddle points, and the intersections of the separatrix with the four divertor plates. The relevant measurements consist of three differential poloidal flux measurements, four poloidal field measurements, the current through the multipole shaping coils, and the total plasma current. Function parametrization supplies a very accurate interpretation of these data, which is now used for online data analysis, and is also sufficiently fast to be suitable for real-time control of the plasma. (orig.)

  10. Calculation of stationary plasma parameters in an electromagnetic trap

    International Nuclear Information System (INIS)

    Karpukhin, V.I.; Lavrent'ev, O.A.; Sappa, N.N.

    1978-01-01

    The model of energy and particle balance is considered and the numerical calculations for stationary plasma parameters, supported by the electron injection, are obtained for a hypothetical electromagnetic trap with linear dimensions, magnetic field strength and energy contribution to plasma of the order of these parameters for the modern tokamak-type traps. The process of limitation of an effective injection current and energy contribution to plasma caused by returning of electrons to the injector due to diffusion in the velocity space is simulated. In approximation of a classical diffusion dependences are obtained of the effective energy contribution to plasma and of the parameters ntausub(E) and Tsub(i) (n is a plasma density; tausub(E)- energetic lifetime; Tsub(i) ion temperature) on electron injection current and power and on the confining magnetic field strength. It had been established that at classical character of diffusion in electromagnetic trap with above parameters one could obtain stationary plasma with ntausub(E)=10 12 cm -3 s and Tsub(i)=1keV, maintaining only by electron injection

  11. Characterization of plasma parameters in shaped PBX-M discharges

    Science.gov (United States)

    England, A. C.; Bell, R. E.; Hirshman, S. P.; Kaita, R.; Kugel, H. W.; LeBlanc, B. L.; Lee, D. K.; Okabayashi, M.; Sun, Y.-C.; Takahashi, H.

    1997-09-01

    The Princeton Beta Experiment-Modification (PBX-M) was run both with elliptical and with bean-shaped plasmas during the 1992 and 1993 operating periods. Two deuterium-fed neutral beams were used for auxiliary heating, and during 1992 the average power was 0741-3335/39/9/008/img13. This will be referred to as the lower neutral-beam power (LNBP) period. As many as four deuterium-fed neutral beams were used during 1993, and the average power was 0741-3335/39/9/008/img14. This will be referred to as the medium neutral-beam power (MNBP) period. The neutron source strength, Sn, showed a scaling with injected power 0741-3335/39/9/008/img15, 0741-3335/39/9/008/img16 for both the LMBP and MNBP periods. A much wider range of shaping parameters was studied during the MNBP as compared with the LNBP period. A weak positive dependence on bean shaping was observed for the LNBP, and a stronger positive dependence on shaping was observed for MNBP, viz 0741-3335/39/9/008/img17. High values of Sn were obtained in bean-shaped plasmas for the highest values of 0741-3335/39/9/008/img18 at 0741-3335/39/9/008/img19 for the LNBP. For the MNBP the highest values of Sn and stored energy were obtained at 0741-3335/39/9/008/img19, and the highest values of 0741-3335/39/9/008/img18 were obtained at 0741-3335/39/9/008/img22. The achievement of high Sn is aided by high neutral-beam power, high toroidal field, strong shaping, high electron temperature, and broad profiles. The achievement of high 0741-3335/39/9/008/img18 is aided by low toroidal field, high density, less shaping, broad profiles, and access to the H-mode, viz 0741-3335/39/9/008/img24. The achievement of high 0741-3335/39/9/008/img25 is aided by strong shaping, high density, broad profiles, and access to the H-mode, viz 0741-3335/39/9/008/img26. Some comparisons with the previous higher neutral-beam (HNBP) period in 1989 are also made.

  12. Experimental study on plasma parameters in the mushroom limiter shadow in the T-10 tokamak

    International Nuclear Information System (INIS)

    Alferov, A.A.; Vershkov, V.A.; Grashin, S.A.; Chankin, A.V.

    1988-01-01

    Plasma parameters in the shadow of mashroom limiter installed in the lower tokamak outlet are studied. Investigation into asymmetry of plasma fluxes to the ion and electrone limiter sides leads to a consumption concerning two meachanisms of its occurrance-toroidal plasma rotation and prevailing plasma departure to the wall through the external torus encirclement. Asymmetry of plasma drift potentials near the limiter observed during the experiment leads to current drift through the limiter close to Spitzer j s one. It is shown that with the increase of mean plasma density the plasma density in the limiter channels grows and its temperature is decreased so the charged particle losses for the limiter are weakly dependent on the mean density which is connected with plasma confinement degradation under the density reduction. A complete flux of charged particles to the limiter is comparable to their flux from plasma filament. Plasma flux into the channels is close to ambipolar one and the power fluxes to neutralization plates are of the order of 10 j s Te/e. Neutral gas pressure dependence in the volume under the limiter on the plasma fluxes to channels is nonlinear, the maximum pressure achieves 3x10 -2 T

  13. Assessment of thermodynamic parameters of plasma shock wave

    International Nuclear Information System (INIS)

    Vasileva, O V; Isaev, Yu N; Budko, A A; Filkov, A I

    2014-01-01

    The work is devoted to the solution of the one-dimensional equation of hydraulic gas dynamics for the coaxial magneto plasma accelerator by means of Lax-Wendroff modified algorithm with optimum choice of the regularization parameter artificial viscosity. Replacement of the differential equations containing private derivatives is made by finite difference method. Optimum parameter of regularization artificial viscosity is added using the exact known decision of Soda problem. The developed algorithm of thermodynamic parameter calculation in a braking point is proved. Thermodynamic parameters of a shock wave in front of the plasma piston of the coaxial magneto plasma accelerator are calculated on the basis of the offered algorithm. Unstable high-frequency fluctuations are smoothed using modeling and that allows narrowing the ambiguity area. Results of calculation of gas dynamic parameters in a point of braking coincide with literary data. The chart 3 shows the dynamics of change of speed and thermodynamic parameters of a shock wave such as pressure, density and temperature just before the plasma piston

  14. Concurrently adjusting interrelated control parameters to achieve optimal engine performance

    Science.gov (United States)

    Jiang, Li; Lee, Donghoon; Yilmaz, Hakan; Stefanopoulou, Anna

    2015-12-01

    Methods and systems for real-time engine control optimization are provided. A value of an engine performance variable is determined, a value of a first operating condition and a value of a second operating condition of a vehicle engine are detected, and initial values for a first engine control parameter and a second engine control parameter are determined based on the detected first operating condition and the detected second operating condition. The initial values for the first engine control parameter and the second engine control parameter are adjusted based on the determined value of the engine performance variable to cause the engine performance variable to approach a target engine performance variable. In order to cause the engine performance variable to approach the target engine performance variable, adjusting the initial value for the first engine control parameter necessitates a corresponding adjustment of the initial value for the second engine control parameter.

  15. Optimization of plasma flow parameters of the magnetoplasma compressor

    International Nuclear Information System (INIS)

    Dojcinovic, I P; Kuraica, M M; Obradovc, B M; Cvetanovic, N; Puric, J

    2007-01-01

    Optimization of the working conditions of the magnetoplasma compressor (MPC) has been performed through analysing discharge and compression plasma flow parameters in hydrogen, nitrogen and argon at different pressures. Energy conversion rate, volt-ampere curve exponent and plasma flow velocities have been studied to optimize the efficiency of energy transfer from the supply source to the plasma. It has been found that the most effective energy transfer from the supply to the plasma is in hydrogen as a working gas at 1000 Pa pressure. It was found that the accelerating regime exists for hydrogen up to 3000 Pa pressures, in nitrogen up to 2000 Pa and in argon up to 1000 Pa pressure. At higher pressures MPC in all the gases works in the decelerating regime. At pressures lower than 200 Pa, high cathode erosion is observed. MPC plasma flow parameter optimization is very important because this plasma accelerating system may be of special interest for solid surface modification and other technology applications

  16. Achieving High Accuracy in Calculations of NMR Parameters

    DEFF Research Database (Denmark)

    Faber, Rasmus

    quantum chemical methods have been developed, the calculation of NMR parameters with quantitative accuracy is far from trivial. In this thesis I address some of the issues that makes accurate calculation of NMR parameters so challenging, with the main focus on SSCCs. High accuracy quantum chemical......, but no programs were available to perform such calculations. As part of this thesis the CFOUR program has therefore been extended to allow the calculation of SSCCs using the CC3 method. CC3 calculations of SSCCs have then been performed for several molecules, including some difficult cases. These results show...... vibrations must be included. The calculation of vibrational corrections to NMR parameters has been reviewed as part of this thesis. A study of the basis set convergence of vibrational corrections to nuclear shielding constants has also been performed. The basis set error in vibrational correction...

  17. North-South asymmetry of interplanetary plasma and solar parameters

    International Nuclear Information System (INIS)

    El-Borie, M. A.

    2001-01-01

    Data of interplanetary plasma (field magnitude, solar wind speed, ion plasma density and temperature) and solar parameters (sunspot number, solar radio flux, and geomagnetic index) over the period 1965-1991, have been used to examine the asymmetry between the solar field north and south of the heliospheric current sheet (HCS). The dependence of N-S asymmetry of field magnitude (B) upon the interplanetary solar polarities is statistically insignificant. There is no clear indication for the presence of N-S asymmetry in the grand-average field magnitude over the solar cycles. During the period 1981-89 (qA<0; negative solar polarity state), the solar plasma was more dense and cooler south of the HCS than north of it. The solar flux component of toward field vector is larger in magnitude than those of away field vector during the qA<0 epoch, and no asymmetry observed in the qA<0 epoch. Furthermore, the sign of the N-S asymmetry in the solar activity depends positively upon the solar polarity state. In addition, it was studied the N-S asymmetry of solar parameters near the HCS, throughout the periods of northern and southern hemispheres were more active than the other. Some asymmetries (with respect to the HCS) in plasma parameters existed during the periods of southern hemisphere predominance

  18. Typical parameters of the plasma chemical similarity in non-isothermal reactive plasmas

    International Nuclear Information System (INIS)

    Gundermann, S.; Jacobs, H.; Miethke, F.; Rutsher, A.; Wagner, H.E.

    1996-01-01

    The substance of physical similarity principles is contained in parameters which govern the comparison of different realizations of a model device. Because similarity parameters for non-isothermal plasma chemical reactors are unknown to a great extent, an analysis of relevant equations is given together with some experimental results. Modelling of the reactor and experimental results for the ozone synthesis are presented

  19. Effects of plasma jet parameters, ionization, thermal conduction, and radiation on stagnation conditions of an imploding plasma liner

    Science.gov (United States)

    Stanic, Milos

    The disciplines of High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF) are characterized by hypervelocity implosions and strong shocks. The Plasma Liner Experiment (PLX) is focused on reaching HEDP and/or ICF relevant regimes in excess of 1 Mbar peak pressure by the merging and implosion of discrete plasma jets, as a potentially efficient path towards these extreme conditions in a laboratory. In this work we have presented the first 3D simulations of plasma liner, formation, and implosion by the merging of discrete plasma jets in which ionization, thermal conduction, and radiation are all included in the physics model. The study was conducted by utilizing a smoothed particle hydrodynamics code (SPHC) and was a part of the plasma liner experiment (PLX). The salient physics processes of liner formation and implosion are studied, namely vacuum propagation of plasma jets, merging of the jets (liner forming), implosion (liner collapsing), stagnation (peak pressure), and expansion (rarefaction wave disassembling the target). Radiative transport was found to significantly reduce the temperature of the liner during implosion, thus reducing the thermal expansion rates and leaving more pronounced gradients in the plasma liner during the implosion compared with ideal hydrodynamic simulations. These pronounced gradients lead to a greater sensitivity of initial jet geometry and symmetry on peak pressures obtained. Accounting for ionization and transport, many cases gave higher peak pressures than the ideal hydrodynamic simulations. Scaling laws were developed accordingly, creating a non-dimensional parameter space in which performance of an imploding plasma jet liner can be estimated. It is shown that HEDP regimes could be reached with ≈ 5 MJ of liner energy, which would translate to roughly 10 to 20 MJ of stored (capacitor) energy. This is a potentially significant improvement over the currently available means via ICF of achieving HEDP and nuclear

  20. Relationship between plasma and tissue parameters of leucine metabolism

    International Nuclear Information System (INIS)

    Vazquez, J.A.; Paul, H.S.; Adibi, S.A.

    1986-01-01

    Using a primed continuous infusion of [1- 14 C] leucine, the authors investigated parameters of leucine metabolism in plasma, expired air, and tissues of fed and 48-hour starved rats. The ratios of muscle/plasma specific activity of α-ketoisocaproate (KIC) in fed and starved rats, respectively were not significantly different from one (1.07 +/- 0.14 and 0.97 +/- 0.10, mean +/- SE, 7 rats). The ratio of muscle/plasma specific activity of leucine was also not significantly different from one (0.86 +/- 0.11) in fed rats, but was significantly lower than one (0.80 +/- 0.07) in starved rats. The rate of leucine oxidation was approximately 32% higher when calculated based on plasma KIC rather than leucine specific activity. However, starvation significantly increased the rate of leucine oxidation with either specific activity. The rate of leucine incorporation into whole body protein was unaffected by starvation (32.7 +/- 3.5 vs 36.1 +/- 2.5 μmol/100 g/h), but the incorporation into total protein of liver (1350 +/- 140 vs 780 +/- 33 nmol) and of skeletal muscle (1940 +/- 220 vs 820 +/- 60 nmol) was significantly decreased. The authors conclude that a) leucine or KIC specific activity in muscle is better predicted by plasma KIC than leucine specific activity, and b) the tracer infusion technique is valid for the study of leucine oxidation but not for leucine incorporation into whole body protein

  1. Study of the transport parameters of cloud lightning plasmas

    International Nuclear Information System (INIS)

    Chang, Z. S.; Yuan, P.; Zhao, N.

    2010-01-01

    Three spectra of cloud lightning have been acquired in Tibet (China) using a slitless grating spectrograph. The electrical conductivity, the electron thermal conductivity, and the electron thermal diffusivity of the cloud lightning, for the first time, are calculated by applying the transport theory of air plasma. In addition, we investigate the change behaviors of parameters (the temperature, the electron density, the electrical conductivity, the electron thermal conductivity, and the electron thermal diffusivity) in one of the cloud lightning channels. The result shows that these parameters decrease slightly along developing direction of the cloud lightning channel. Moreover, they represent similar sudden change behavior in tortuous positions and the branch of the cloud lightning channel.

  2. A proposed method for fast determination of plasma parameters

    International Nuclear Information System (INIS)

    Braams, B.J.; Lackner, K.

    1984-09-01

    The method of function parametrization, developed and applied by H. Wind for fast data evaluation in high energy physics, is presented in the context of controlled fusion research. This method relies on statistical analysis of a data base of simulated experiments in order to obtain a functional representation for the intrinsic physical parameters of a system in terms of the values of the measurements. Some variations on Wind's original procedure are suggested. A specific application for tokamak experiments would be the determination of certain global parameters of the plasma, characterizing the current profile, shape of the cross-section, plasma pressure, and the internal inductance. The relevant measurements for this application include values of the poloidal field and flux external to the plasma, and a diamagnetic measurement. These may be combined with other diagnostics, such as electron-cyclotron emission and laser interferometry, in order to obtain also density and temperature profiles. There appears to be a capability for on-line determination of basic physical parameters, in a millisecond timescale on a minicomputer instead of in seconds on a large mainframe. (orig.)

  3. Simulation of experimentally achieved detached plasmas using the UEDGE code

    International Nuclear Information System (INIS)

    Porter, G.D.; Allen, S.; Fenstermacher, M.

    1995-01-01

    The introduction of a divertor Thomson scattering system in DIII-D has enabled accurate determination of the plasma properties in the divertor region. We identify two plasma regimes; detached and attached. The electron temperature in the detached regime is about 2 eV, much lower than 5 to 10 eV determined earlier. We show that fluid models of the DIII-D scrape-off layer plasma are able to reproduce many of the features of these two plasma regimes, including the boundaries for transition between them. Detailed comparison between the results obtained from the fluid models and experiment suggest the models underestimate the spatial extent of the low temperature region associated the detached plasma mode. We suggest that atomic physics processes at the low electron temperatures reported here may account for this discrepancy

  4. Scaling laws of design parameters for plasma wakefield accelerators

    International Nuclear Information System (INIS)

    Uhm, Han S.; Nam, In H.; Suk, Hyyong

    2012-01-01

    Simple scaling laws for the design parameters of plasma wakefield accelerators were obtained using a theoretical model, which were confirmed via particle simulation studies. It was found that the acceleration length was given by Δx=0.804λ p /(1−β g ), where λ p is the plasma wavelength and β g c the propagation velocity of the ion cavity. The acceleration energy can also be given by ΔE=(γ m −1)mc 2 =2.645mc 2 /(1−β g ), where m is the electron rest mass. As expected, the acceleration length and energy increase drastically as β g approached unity. These simple scaling laws can be very instrumental in the design of better-performing plasma wakefield accelerators. -- Highlights: ► Simple scaling laws for the design parameters of laser wakefield accelerators were obtained using a theoretical model. ► The scaling laws for acceleration length and acceleration energy were compared with particle-in-cell simulation results. ► The acceleration length and the energy increase drastically as β g approaches unity. ► These simple scaling laws can be very instrumental in the design of laser wakefield accelerators.

  5. Study on spatial distribution of plasma parameters in a magnetized inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong, E-mail: kwhang@snu.ac.kr [Plasma Laboratory, Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Hyuk [Samsung Electronics Co., Banwol-dong, Hwaseong 445-701 (Korea, Republic of); Park, Wanjae [Tokyo Electron Miyagi Ltd., Taiwa-cho, Kurokawa-gun, Miyagi 981-3629 (Japan)

    2015-07-15

    Spatial distributions of various plasma parameters such as plasma density, electron temperature, and radical density in an inductively coupled plasma (ICP) and a magnetized inductively coupled plasma (M-ICP) were investigated and compared. Electron temperature in between the rf window and the substrate holder of M-ICP was higher than that of ICP, whereas the one just above the substrate holder of M-ICP was similar to that of ICP when a weak (<8 G) magnetic field was employed. As a result, radical densities in M-ICP were higher than those in ICP and the etch rate of oxide in M-ICP was faster than that in ICP without severe electron charging in 90 nm high aspect ratio contact hole etch.

  6. Achievement of solid-state plasma fusion ('Cold-Fusion')

    International Nuclear Information System (INIS)

    Arata, Yoshiaki; Zhang, Yue-Chang

    1995-01-01

    Using a 'QMS' (Quadrupole Mass Spectrometer), the authors detected a significantly large amount (10 20 -10 21 [cm -3 ]) of helium ( 2 4 He), which was concluded to have been produced by a deuterium nuclear reaction within a host solid. These results were found to be fully repeatable and supported the authors' proposition that solid state plasma fusion ('Cold Fusion') can be generated in energetic deuterium Strongly Coupled Plasma ('SC-plasma'). This fusion reaction is thought to be sustained by localized 'Latticequake' in a solid-state media with the deuterium density equivalent to that of the host solid. While exploring this basic proposition, the characteristic differences when compared with ultra high temperature-state plasma fusion ('Hot Fusion') are clarified. In general, the most essential reaction product in both types of the deuterium plasma fusion is considered to be helium, irrespective of the 'well-known and/or unknown reactions', which is stored within the solid-state medium in abundance as a 'Residual Product', but which generally can not enter into nor be released from host-solid at a room temperature. Even measuring instruments with relatively poor sensitivity should be able to easily detect such residual helium. An absence of residual helium means that no nuclear fusion reaction has occurred, whereas its presence provides crucial evidence that nuclear fusion has, in fact, occurred in the solid. (author)

  7. Stationary neoclassical profiles of plasma parameters in stellarators

    International Nuclear Information System (INIS)

    Danilkin, I.S.; Mineev, A.B.

    1991-01-01

    The properties of the neoclassical model of heat and particle transport are considered in connection with calculations of stationary profiles of the plasma parameters in stellarators. The most important feature is the poor agreement with real physical conditions of the boundary, which imposes the necessity of invoking either an additional anomalous transport or a special (although technically possible) consistency between the particle and heat sources in order to obtain a solution in the form of a correct monotonically decreasing profile. In search for monotonic stationary profiles maintained by external sources, it is ascertained that the neoclassical theory does not give rise to the well-known multivalued solutions for the ambipolar electric field

  8. Experimental and numerical investigation of plasma parameters in the magnetosheath

    Directory of Open Access Journals (Sweden)

    Dobreva Polya

    2018-01-01

    Full Text Available We investigate the behaviour of the plasma parameters in the magnetosheath in a case when Interball-1 satellite stayed in the magnetosheath, crossing the tail magnetopause. In our analysis we apply the numerical magnetosheath-magnetosphere model as a theoretical tool. The bow shock and the magnetopause are self-consistently determined in the process of the solution. The flow in the magnetosheath is governed by the Euler equations of compressible ideal gas. The magnetic field in the magnetosphere is calculated by a variant of the Tsyganenko model, modified to account for an asymmetric magnetopause. Also, the magnetopause currents in Tsyganenko model are replaced by numericaly calulated ones. Measurements from WIND spacecraft are used as a solar wind monitor. The results demonstrate a good agreement between the model-calculated and measured values of the parameters under investigation.

  9. Effect of solar wind plasma parameters on space weather

    International Nuclear Information System (INIS)

    Rathore, Balveer S.; Gupta, Dinesh C.; Kaushik, Subhash C.

    2015-01-01

    Today's challenge for space weather research is to quantitatively predict the dynamics of the magnetosphere from measured solar wind and interplanetary magnetic field (IMF) conditions. Correlative studies between geomagnetic storms (GMSs) and the various interplanetary (IP) field/plasma parameters have been performed to search for the causes of geomagnetic activity and develop models for predicting the occurrence of GMSs, which are important for space weather predictions. We find a possible relation between GMSs and solar wind and IMF parameters in three different situations and also derived the linear relation for all parameters in three situations. On the basis of the present statistical study, we develop an empirical model. With the help of this model, we can predict all categories of GMSs. This model is based on the following fact: the total IMF B total can be used to trigger an alarm for GMSs, when sudden changes in total magnetic field B total occur. This is the first alarm condition for a storm's arrival. It is observed in the present study that the southward B z component of the IMF is an important factor for describing GMSs. A result of the paper is that the magnitude of B z is maximum neither during the initial phase (at the instant of the IP shock) nor during the main phase (at the instant of Disturbance storm time (Dst) minimum). It is seen in this study that there is a time delay between the maximum value of southward B z and the Dst minimum, and this time delay can be used in the prediction of the intensity of a magnetic storm two-three hours before the main phase of a GMS. A linear relation has been derived between the maximum value of the southward component of B z and the Dst, which is Dst = (−0.06) + (7.65) B z +t. Some auxiliary conditions should be fulfilled with this, for example the speed of the solar wind should, on average, be 350 km s −1 to 750 km s −1 , plasma β should be low and, most importantly, plasma temperature

  10. Impact of gas puffing location on density control and plasma parameters in TJ-II

    International Nuclear Information System (INIS)

    Tabares, F.L.; Garcia-Cortes, I.; Estrada, T.; Tafalla, D.; Hidalgo, A.; Ferreira, J.A.; Pastor, I.; Herranz, J.; Ascasibar, E.

    2005-01-01

    Under pure Electron Cyclotron Resonance Heating (ECRH) conditions in TJ-II plasmas (P<300 kW, 53.2 GHz, 2nd harmonic X-mode, power density < 25 W/m''3), plasma start-up and good density control are obtained only by the proper combination of wall conditions and gas puffing characteristics. Such a control is particularly critical for the optimisation of the NBI power transfer to the target plasmas. The relatively low cut-off limit is easily reached due not only to the unfavourable wall/puffing-fuelling ratio but also due to the steep density profiles developed during the Enhanced Particle Confinement (EPC) modes. These modes are triggered by the gas puffing waveform, and they cannot be achieved for high iota magnetic configurations in TJ-II. Comparative experiments under metallic and boronised wall conditions have shown that the sensitivity of the EPC modes to the puffing rate is at least partially related to the energy balance at the plasma periphery under central heating scenarios. In this work, the impact of gas-fuelling location on the plasma parameters and density control is described. For that purpose, three different fuelling locations have been investigated; broad distribution from a side ports, localized injection from long tubes at different poloidal positions and highly localized injection through a movable limiter. Edge density and temperature profiles from a broad set of diagnostics (atomic beams, reflectometry, Thompson Scattering ECE, etc...) are analysed and compared. It has been found that preventing from transition to the EPC mode is achieved by using slow puffing rates, while neutral penetration into the plasma core can be enhanced for highly localized gas sources. Wall inventory, however, has been found to pl ay a dominant role in the fuelling of the plasma under most conditions. (author)

  11. Optimization of the plasma parameters for the high current and uniform large-scale pulse arc ion source of the VEST-NBI system

    International Nuclear Information System (INIS)

    Jung, Bongki; Park, Min; Heo, Sung Ryul; Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

    2016-01-01

    Highlights: • High power magnetic bucket-type arc plasma source for the VEST NBI system is developed with modifications based on the prototype plasma source for KSTAR. • Plasma parameters in pulse duration are measured to characterize the plasma source. • High plasma density and good uniformity is achieved at the low operating pressure below 1 Pa. • Required ion beam current density is confirmed by analysis of plasma parameters and results of a particle balance model. - Abstract: A large-scale hydrogen arc plasma source was developed at the Korea Atomic Energy Research Institute for a high power pulsed NBI system of VEST which is a compact spherical tokamak at Seoul national university. One of the research target of VEST is to study innovative tokamak operating scenarios. For this purpose, high current density and uniform large-scale pulse plasma source is required to satisfy the target ion beam power efficiently. Therefore, optimizing the plasma parameters of the ion source such as the electron density, temperature, and plasma uniformity is conducted by changing the operating conditions of the plasma source. Furthermore, ion species of the hydrogen plasma source are analyzed using a particle balance model to increase the monatomic fraction which is another essential parameter for increasing the ion beam current density. Conclusively, efficient operating conditions are presented from the results of the optimized plasma parameters and the extractable ion beam current is calculated.

  12. Revisiting linear plasma waves for finite value of the plasma parameter

    Science.gov (United States)

    Grismayer, Thomas; Fahlen, Jay; Decyk, Viktor; Mori, Warren

    2010-11-01

    We investigate through theory and PIC simulations the Landau-damping of plasma waves with finite plasma parameter. We concentrate on the linear regime, γφB, where the waves are typically small and below the thermal noise. We simulate these condition using 1,2,3D electrostatic PIC codes (BEPS), noting that modern computers now allow us to simulate cases where (nλD^3 = [1e2;1e6]). We study these waves by using a subtraction technique in which two simulations are carried out. In the first, a small wave is initialized or driven, in the second no wave is excited. The results are subtracted to provide a clean signal that can be studied. As nλD^3 is decreased, the number of resonant electrons can be small for linear waves. We show how the damping changes as a result of having few resonant particles. We also find that for small nλD^3 fluctuations can cause the electrons to undergo collisions that eventually destroy the initial wave. A quantity of interest is the the life time of a particular mode which depends on the plasma parameter and the wave number. The life time is estimated and then compared with the numerical results. A surprising result is that even for large values of nλD^3 some non-Vlasov discreteness effects appear to be important.

  13. Plasma-parameter measurements using neutral-particle-beam attenuation

    International Nuclear Information System (INIS)

    Foote, J.H.; Molvik, A.W.; Turner, W.C.

    1982-01-01

    Intense and energetic neutral-particle-beam injection used for fueling or heating magnetically confined, controlled-fusion experimental plasmas can also provide diagnostic measurements of the plasmas. The attenuation of an atomic beam (mainly from charge-exchange and ionization interactions) when passing through a plasma gives the plasma line density. Orthogonal arrays of highly collimated detectors of the secondary-electron-emission type have been used in magnetic-mirror experiments to measure neutral-beam attenuation along chords through the plasma volume at different radial and axial positions. The radial array is used to infer the radial plasma-density profile; the axial array, to infer the axial plasma-density profile and the ion angular distribution at the plasma midplane

  14. Voyager microwave scintillation measurements of solar wind plasma parameters

    International Nuclear Information System (INIS)

    Martin, J.M.

    1985-01-01

    During the solar conjunctions of Voyager 1 and 2 spacecraft in August 1979, September 1980, and November 1982, temporal variations of intensity and frequency of the dual-wavelength (3.6 and 13 cm) radio transmissions from the spacecraft were observed and subsequently analyzed to infer characteristics of the solar wind plasma flow. Measurements of the temporal wave structure function were used to estimate the spectral index of the power law spatial spectrum of irregularities. Theoretical-intensity scintillation spectra were compared with measured intensity spectra to obtain least-squares estimates of (1) mean velocity, (2) random velocity, (3) axial ratio, and (4) electron density standard deviation. Uncertainties in parameter estimates were calculated by standard propagation of errors techniques. Mean velocity and electron density standard deviations in 1979-1980 show little dependence on solar latitude. Density standard deviation estimates were 3-10% of the background mean density and mean velocity estimates ranged from approx.200 km/s inside 17 solar radii to approx.300 km/s at 25 solar radii. 1982 density standard deviation estimates increased rapidly with latitude near 45 0 N, then sharply decreased north of that latitude, indicating the existence of a polar region of reduced fluctuations surrounded by a thin cone of strong density irregularities

  15. Numerical study for determining PF coil system parameters in MHD equilibrium of KT-2 tokamak plasma

    International Nuclear Information System (INIS)

    Ryu, J.; Hong, S.H.; Lee, K.W.; Hong, B.G.; In, S.R.; Kim, S.K.

    1995-01-01

    The KT-2 is a large-aspect-ratio medium-sized divertor tokamak in the conceptual design phase and planned to be operational in 1998 at the Korea Atomic Energy Research Institute (KAERI). Plasma equilibrium in tokamak can be acquired by controlling the current of poloidal field (PF) coils in appropriate geometries and positions. In this study, the authors have performed numerical calculations to achieve the various equilibrium conditions fitting given plasma shapes and satisfying PF current limitations. Usually an ideal magnetohydrodynamic (MHD) equation is used to obtain the equilibrium solution of tokamak plasma, and it is practical to take advantage of a numerical method in solving the MHD equation because it has nonlinear source terms. Two equilibrium codes have been applied to find a double-null configuration of free-boundary tokamak plasma in KT-2: one is of the authors' own developing and the other is a free-boundary tokamak equilibrium code (FBT) that has been used mainly for the verification of developed code's results. PF coil system parameters including their positions and currents are determined for the optimization of input power required when the specifications of KT-2 tokamak are met. Then, several sets of equilibrium conditions during the tokamak operation are found to observe the changes of poloidal field currents with the passing of operation time step, and the basic stability problems related with the magnetic field structure is also considered

  16. The effects of varying plasma parameters on silicon thin film growth by ECR plasma CVD

    International Nuclear Information System (INIS)

    Summers, S.; Reehal, H.S.; Shirkoohi, G.H.

    2001-01-01

    The technique of electron cyclotron resonance (ECR) plasma enhanced chemical vapour deposition (PECVD) is increasingly being used in electronic and photonic device applications. ECR offers a number of advantages including improved control of the deposition process, less damage to the growing film and the possibility of high deposition rates. ECR occurs in a plasma under appropriate magnetic and electric field conditions. In most cases, as in our system, this is achieved with a combination of 2.45 GHz microwave radiation and a 0.0875 T magnetic field, due to the use of standardized microwave supplies. We have studied the effects on silicon film growth of changing the magnetic field configuration to produce one or more planes of ECR within the system, and of changing the positions of the plane(s) relative to the deposition substrate. The films were grown in silane-hydrogen discharges. The magnetic field in our system was provided by two electromagnets. It was measured experimentally for a number of operating current values and then a detailed profile achieved by modelling using a proprietary software package. A process condition discharge under identical magnetic field configurations to growth was analysed by the use of a Langmuir probe and the results correlated with film properties determined by Raman spectroscopy and Dektak profilometry. (author)

  17. Ion source plasma parameters measurement based on Langmuir probe with commercial frequency sweep

    International Nuclear Information System (INIS)

    Xie, Y.H.; Hu, C.D.; Liu, S.; Shong, S.H.; Jiang, C.C.; Liu, Z.M.

    2010-01-01

    Langmuir probe is one of the main diagnostic tools to measure the plasma parameters in the ion source. In this article, the commercial frequency power, which is sine wave of 50 Hz, was supplied on the Langmuir probe to measure the plasma parameters. The best feature of this probe sweep voltage is that it does not need extra design. The probe I-V characteristic curve can be got in less than 5 ms and the plasma parameters, the electron temperature and the electron density, varying with the time can be got in one plasma discharge of 400 ms.

  18. Achieving uniform layer deposition by atmospheric-pressure plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Ok [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Kang, Woo Seok, E-mail: kang@kimm.re.kr [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of); Hur, Min; Lee, Jin Young [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Song, Young-Hoon [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of)

    2015-12-31

    This work investigates the use of plasma-enhanced chemical vapor deposition under atmospheric pressure for achieving uniform layer formation. Electrical and optical measurements demonstrated that the counterbalance between oxygen and precursors maintained the homogeneous discharge mode, while creating intermediate species for layer deposition. Several steps of the deposition process of the layers, which were processed on a stationary stage, were affected by flow stream and precursor depletion. This study showed that by changing the flow streamlines using substrate stage motion uniform layer deposition under atmospheric pressure can be achieved. - Highlights: • Zirconium oxide was deposited by atmospheric-pressure plasma-enhanced chemical vapor deposition. • Homogeneous plasma was maintained by counterbalancing between discharge gas and precursors. • Several deposition steps were observed affected by the gas flow stream and precursor depletion. • Thin film layer was uniformly grown when the substrate underwent a sweeping motion.

  19. Evaluation of the plasma parameters in COMPASS tokamak divertor area

    Czech Academy of Sciences Publication Activity Database

    Dimitrova, M.; Ivanova, P.; Kotseva, I.; Popov, Tsv.K.; Benova, E.; Bogdanov, T.; Stöckel, Jan; Dejarnac, Renaud

    2012-01-01

    Roč. 356, č. 1 (2012), s. 012007 ISSN 1742-6588. [InternationalSummerSchoolonVacuum,Electron, and IonTechnologies(VEIT2011)/17./. Sunny Beach, 19.09.2011-23.09.2011] Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma * tokamak * diagnostics * electric probe * magnetic-field * Langmuir probe * intermediate * pressures Subject RIV: BL - Plasma and Gas Discharge Physics http://iopscience.iop.org/1742-6596/356/1/012007/pdf/1742-6596_356_1_012007.pdf

  20. The effect of plasma parameter on the bootstrap current of fast ions in neutral beam injection

    International Nuclear Information System (INIS)

    Huang Qianhong; Gong Xueyu; Cao Jinjia; Yang Lei

    2014-01-01

    The effect of plasma parameters on the distribution of net current density of fast ions produced by neutral beam injection is investigated in a large-aspect-ratio Tokamak with circular cross-section under specific parameters. Numerical results show that the value of net current density increases with the temperature of plasma increasing and decreases with the density of plasma increasing. The value of net current density is weakly affected by the effective charge number, but the peak of net current density moves towards edge plasma with effective charge number increasing. (authors)

  1. RF plasma parameter determination by a Langmuir multipoint double probe array

    International Nuclear Information System (INIS)

    Rojas-Olmedo, I A; López-Callejas, R; De la Piedad-Beneitez, A; Valencia-Alvarado, R; Peña-Eguiluz, R; Mercado-Cabrera, A; Barocio, S R; Muñoz-Castro, A E; Rodríguez-Méndez, B G

    2012-01-01

    A multipoint double Langmuir (MDL) probe system, which is exempt from interference, has been designed and assembled to be applied to an RF plasma. The system provides the measurement of fundamental plasma parameters such as density, temperature, plasma potential, etc. on the basis of the Bohm Approximation Theory and the Orbital Movement Limit. Thus, one pair of the MDL system is selected so as to consider the right plasma parameters within the prevailing pressure-power intervals. Both the hardware and software of the system have been applied to the modification of material properties by means of the PIII process.

  2. Measurements of egg shell plasma parameters using laser-induced ...

    Indian Academy of Sciences (India)

    In LIBS, a high-intensity laser is focussed onto the sample, which is strong ... Compared to the production of plasma, qualitative and quantitative analyses are ... In this paper, the elemental composition of the egg shell crushed to a size of about.

  3. Plasma Arc Cutting Dimensional Accuracy Optimization employing the Parameter Design approach

    Directory of Open Access Journals (Sweden)

    Kechagias John

    2017-01-01

    Full Text Available Plasma Arc Cutting (PAC is a thermal manufacturing process used for metal plates cutting. This work experimentally investigates the influence of process parameters onto the dimensional accuracy performance of the plasma arc cutting process. The cutting parameters studied were cutting speed (mm/min, torch standoff distance (mm, and arc voltage (volts. Linear dimensions of a rectangular workpiece were measured after PAC cutting following the full factorial design experimental approach. For each one of the three process parameters, three parameter levels were used. Analysis of means (ANOM and analysis of variances (ANOVA were performed in order for the effect of each parameter on the leaner dimensional accuracy to be assessed.

  4. Dependence of the source performance on plasma parameters at the BATMAN test facility

    Science.gov (United States)

    Wimmer, C.; Fantz, U.

    2015-04-01

    The investigation of the dependence of the source performance (high jH-, low je) for optimum Cs conditions on the plasma parameters at the BATMAN (Bavarian Test MAchine for Negative hydrogen ions) test facility is desirable in order to find key parameters for the operation of the source as well as to deepen the physical understanding. The most relevant source physics takes place in the extended boundary layer, which is the plasma layer with a thickness of several cm in front of the plasma grid: the production of H-, its transport through the plasma and its extraction, inevitably accompanied by the co-extraction of electrons. Hence, a link of the source performance with the plasma parameters in the extended boundary layer is expected. In order to characterize electron and negative hydrogen ion fluxes in the extended boundary layer, Cavity Ring-Down Spectroscopy and Langmuir probes have been applied for the measurement of the H- density and the determination of the plasma density, the plasma potential and the electron temperature, respectively. The plasma potential is of particular importance as it determines the sheath potential profile at the plasma grid: depending on the plasma grid bias relative to the plasma potential, a transition in the plasma sheath from an electron repelling to an electron attracting sheath takes place, influencing strongly the electron fraction of the bias current and thus the amount of co-extracted electrons. Dependencies of the source performance on the determined plasma parameters are presented for the comparison of two source pressures (0.6 Pa, 0.45 Pa) in hydrogen operation. The higher source pressure of 0.6 Pa is a standard point of operation at BATMAN with external magnets, whereas the lower pressure of 0.45 Pa is closer to the ITER requirements (p ≤ 0.3 Pa).

  5. Dependence of the source performance on plasma parameters at the BATMAN test facility

    International Nuclear Information System (INIS)

    Wimmer, C.; Fantz, U.

    2015-01-01

    The investigation of the dependence of the source performance (high j H − , low j e ) for optimum Cs conditions on the plasma parameters at the BATMAN (Bavarian Test MAchine for Negative hydrogen ions) test facility is desirable in order to find key parameters for the operation of the source as well as to deepen the physical understanding. The most relevant source physics takes place in the extended boundary layer, which is the plasma layer with a thickness of several cm in front of the plasma grid: the production of H − , its transport through the plasma and its extraction, inevitably accompanied by the co-extraction of electrons. Hence, a link of the source performance with the plasma parameters in the extended boundary layer is expected. In order to characterize electron and negative hydrogen ion fluxes in the extended boundary layer, Cavity Ring-Down Spectroscopy and Langmuir probes have been applied for the measurement of the H − density and the determination of the plasma density, the plasma potential and the electron temperature, respectively. The plasma potential is of particular importance as it determines the sheath potential profile at the plasma grid: depending on the plasma grid bias relative to the plasma potential, a transition in the plasma sheath from an electron repelling to an electron attracting sheath takes place, influencing strongly the electron fraction of the bias current and thus the amount of co-extracted electrons. Dependencies of the source performance on the determined plasma parameters are presented for the comparison of two source pressures (0.6 Pa, 0.45 Pa) in hydrogen operation. The higher source pressure of 0.6 Pa is a standard point of operation at BATMAN with external magnets, whereas the lower pressure of 0.45 Pa is closer to the ITER requirements (p ≤ 0.3 Pa)

  6. Cutoff effects of electron velocity distribution to the properties of plasma parameters near the plasma-sheath boundary

    International Nuclear Information System (INIS)

    Jelic, N.

    2011-01-01

    The plasma properties under high thermodynamic non-equilibrium condition, established due to the presence of electrically biased electrode, are investigated. Assumption of electron cut-off velocity distribution function (VDF), as done by Andrews and Varey in their investigations of the sheath region [J. Phys. A 3, 413 (1970)], has been extended here to both plasma and sheath regions. Analytic expressions for the moments of electron VDF, as well as for the electron screening temperature function dependence on the plasma-sheath local potential are derived. In deriving the ion velocity distribution the ''standard'' assumption of strict plasma quasineutrality, or equivalently vanishing of the plasma Debye length, is employed, whereas the ions are assumed to be generated at rest over the plasma region. However, unlike the standard approach of solving the plasma equation, where pure Boltzmann electron density profile is used, here we employ modified Boltzmann's electron density profile, due to cutoff effect of the electron velocity distribution. It is shown that under these conditions the quasineutrality equation solution is characterised by the electric field singularity for any negative value of the electrode bias potential as measured with respect to the plasma potential. The point of singularity i.e., the plasma length and its dependence on the electrode bias and sheath potential is established for the particular case of ionization profile mechanism proportional to the local electron density. Relevant parameters for the kinetic Bohm criterion are explicitly calculated for both ions and electrons, for arbitrary electrode bias.

  7. The Influence of the Axial Magnetic Field Upon-the Coaxial Plasma Gun Parameters

    International Nuclear Information System (INIS)

    El-Aragi, G.M.; EL-Demrdash, A.

    2001-01-01

    This study concerns with the influence of an applied axial magnetic field upon the electrical parameters of a coaxial plasma gun device. The experimental results are investigated with 0.5 KJ plasma gun device operated with argon gas at a pressure of 3.5 Torr. An axial time independent magnetic field with intensity of 550 G is introduced along the plasma current sheath axial region, within the annular space between the two coaxial electrodes. From the measurements of the discharge current I(t) and the voltage V(t), the electrical discharge parameters of the plasma gun device and the plasma current sheath implosion velocity are estimated, in normal mode of plasma gun operation and in the mode of presence external axial magnetic field. A comparison between these two modes is studied

  8. Effects of boronisation on the plasma parameters in TCA

    International Nuclear Information System (INIS)

    Dudok de Wit, Th.; Duval, B.P.; Hollenstein, Ch.; Joye, B.

    1990-01-01

    Wall conditioning and deposition of low Z materials on the first wall and limiters play an important role in plasma impurity control. Carbon film deposition (carbonisation) is already used on many Tokamaks. As proposed by Veprek, a film containing boron and carbon would be more resistant to chemical erosion and could also getter the oxygen. This procedure (boronisation) has been tried on Textor, Asdex and recently on TCA. The TCA vacuum vessel, the 8 rf antenna groups and 4 antenna screens are stainless steel and there are 4 carbon limiters placed in one poloidal plane. (author) 6 refs., 3 figs

  9. Real time plasma feedback control: An overview of Tore-Supra achievements

    International Nuclear Information System (INIS)

    Martin, G.; Bucalossi, J.; Ekedahl, A.; Gil, C.; Grisolia, C.; Guilhem, D.; Gunn, J.; Kazarian, F.; Moulin, D.; Pascal, J.Y.; Saint-Laurent, F.

    2001-01-01

    Stable and reliable fusion plasma operation requires increasingly advanced control systems. This is especially true for steady-state operation in advanced modes, when several parameters are to be simultaneously optimised: e.g. the current profile, which has been related to the formation of internal transport barrier, and the density, which plays a crucial role both in the fusion power and in the plasma wall interactions. At a more technological level, good management of the power entering and leaving the plasma is required, by efficient additional heating coupling, and with a full control of radiation and convection losses and distribution to the first wall elements. For these goals, several feed-back mechanisms have been developed with success on Tore-Supra, in the past four years. Most of them are based on software, implemented in a set of micro-computers connected through a VME network. (author)

  10. Triple-probe method applied to the direct display of plasma parameters in a supersonic flowing continuum plasma

    International Nuclear Information System (INIS)

    Ogram, G.L.; Chang, J.; Hobson, R.M.

    1979-01-01

    The calibration of electrostatic triple-probe voltage and current response in a supersonic continuum plasma has been carried out using a low-pressure shock tube. The electron temperature T/sub e/ and charge number density N/sub e/ are compared to probe voltage and current response, respectively, for a useful range of plasma parameters (1 13 13 is the nondimensional probe voltage). The dependence of probe response on Debye ratio R/sub p//lambda/sub D/ and various flow parameters was investigated. The probe voltage response was found to depend significantly on the Debye ratio. Expressions for electron temperature determination by triple probe are presented

  11. Study of plasma parameters influencing fractionation in laser ablation-inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Gäckle, M.; Merten, D.

    2010-12-01

    Methods permitting to test the influence of the matrix as well as of its local and temporal distribution on the plasma conditions in laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) are developed. For this purpose, the MS interface is used as plasma probe allowing to investigate the average plasma condition within the ICP zone observed in terms of temporal and spatial distribution of the matrix. Inserted matrix particles, particularly when being atomized and ionized, can cause considerable changes in both electron density and plasma temperature thus influencing the ionization equilibrium of the individual analytes. In this context, the plasma probe covers a region of the plasma for which no local thermodynamic equilibrium can be assumed. The differences in temperature, identified within the region of the plasma observed, amounted up to 3000 K. While in the central region conditions were detected that would not allow efficient atomization and ionization of the matrix, these conditions improve considerably towards the margin of the area observed. Depending on the nature as well as on the temporally and locally variable density of the matrix, this can lead to varying intensity ratios of the analytes and explain fractionation effects. By means of a derived equation it is shown that the deviation of the intensity ratio from the concentration ratio turns out to be more serious the higher the difference of the ionization potential of the analytes observed, the lower the plasma temperature and the higher the matrix concentration within the area observed.

  12. Plasma parameter estimations for the Large Helical Device based on the gyro-reduced Bohm scaling

    International Nuclear Information System (INIS)

    Okamoto, Masao; Nakajima, Noriyoshi; Sugama, Hideo.

    1991-10-01

    A model of gyro-reduced Bohm scaling law is incorporated into a one-dimensional transport code to predict plasma parameters for the Large Helical Device (LHD). The transport code calculations reproduce well the LHD empirical scaling law and basic parameters and profiles of the LHD plasma are calculated. The amounts of toroidal currents (bootstrap current and beam-driven current) are also estimated. (author)

  13. Plasma Arc Cutting Dimensional Accuracy Optimization employing the Parameter Design approach

    OpenAIRE

    Kechagias John; Petousis Markos; Vidakis Nectarios; Mastorakis Nikos

    2017-01-01

    Plasma Arc Cutting (PAC) is a thermal manufacturing process used for metal plates cutting. This work experimentally investigates the influence of process parameters onto the dimensional accuracy performance of the plasma arc cutting process. The cutting parameters studied were cutting speed (mm/min), torch standoff distance (mm), and arc voltage (volts). Linear dimensions of a rectangular workpiece were measured after PAC cutting following the full factorial design experimental approach. For ...

  14. EFFECT OF PLASMA CUTTING PARAMETERS UPON SHAPES OF BEARING CURVE OF C45 STEEL SURFACE

    Directory of Open Access Journals (Sweden)

    Agnieszka Skoczylas

    2015-08-01

    Full Text Available The article presents the results of studies on the effect of plasma cutting technological parameters upon the shape of bearing curves and the parameters of the curve. The topography of surface formed by plasma cutting were analyzed. For measuring surface roughness and determining the bearing curve the appliance T8000 RC120 – 400 by Hommel-Etamic was used together with software.

  15. Analyses of plasma parameter profiles in JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Shirai, Hiroshi; Shimizu, Katsuhiro; Hayashi, Nobuhiko [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Itakura, Hirofumi; Takase, Keizou [CSK Co. Ltd., Tokyo (Japan)

    2001-01-01

    The methods how diagnostics data are treated as the surface quantity of magnetic surface and processed to the profile data in the JT-60U plasmas are summarized. The MHD equilibrium obtained by solving Grad-Shafranov equation on the MHD equilibrium calculation and registration software FBEQU are saved shot by shot as a database. Various experimental plasma data measured at various geometrical positions on JT-60 are mapped onto the MHD equilibrium and treated as functions of the volume averaged minor radius {rho} on the experimental data time slice monitoring software SLICE. Experimental data are integrated and edited on SLICE. The experimental data measured as the line integral values are transformed by Able inversion. The mapped data are fitted to a functional form and saved to the profile database MAP-DB. SLICE can also read data from MAP-DB and redisplay and transform them. In addition, SLICE can generate the profile data TOKRD as run data for orbit following Monte-Carlo (OFMC) code, analyzer for current drive consistent with MHD equilibrium (ACCOME) code and tokamak predictive and interpretive code system (TOPICS). (author)

  16. Analyses of plasma parameter profiles in JT-60U

    International Nuclear Information System (INIS)

    Shirai, Hiroshi; Shimizu, Katsuhiro; Hayashi, Nobuhiko

    2001-01-01

    The methods how diagnostics data are treated as the surface quantity of magnetic surface and processed to the profile data in the JT-60U plasmas are summarized. The MHD equilibrium obtained by solving Grad-Shafranov equation on the MHD equilibrium calculation and registration software FBEQU are saved shot by shot as a database. Various experimental plasma data measured at various geometrical positions on JT-60 are mapped onto the MHD equilibrium and treated as functions of the volume averaged minor radius ρ on the experimental data time slice monitoring software SLICE. Experimental data are integrated and edited on SLICE. The experimental data measured as the line integral values are transformed by Able inversion. The mapped data are fitted to a functional form and saved to the profile database MAP-DB. SLICE can also read data from MAP-DB and redisplay and transform them. In addition, SLICE can generate the profile data TOKRD as run data for orbit following Monte-Carlo (OFMC) code, analyzer for current drive consistent with MHD equilibrium (ACCOME) code and tokamak predictive and interpretive code system (TOPICS). (author)

  17. Plasma parameters for alternate operating modes of TIBER-II

    International Nuclear Information System (INIS)

    Fenstermacher, M.E.; Devoto, R.S.; Logan, B.G.; Perkins, L.J.

    1987-01-01

    Parameters for operating points of TIBER-II, different from the baseline steady-state operation, are presented. These results have been generated with the MUMAK tokamak power balance code. Pulsed ignited and high performance steady-state operating points are described. 20 refs

  18. Biochemical Nutritional Parameters in Breast-milk and Plasma of ...

    African Journals Online (AJOL)

    Undernourishment in HIV infected individuals exacerbates immunosuppression, acceleration of HIV replication and CD4 + T cell depletion. The production of human milk (lactogenesis) is dependent on factors in the blood therefore deranged blood parameters in HIV patients are expected to reflect in the components of ...

  19. Study of geometrical and operational parameters controlling the low frequency microjet atmospheric pressure plasma characteristics

    International Nuclear Information System (INIS)

    Kim, Dan Bee; Rhee, J. K.; Moon, S. Y.; Choe, W.

    2006-01-01

    Controllability of small size atmospheric pressure plasma generated at low frequency in a pin to dielectric plane electrode configuration was studied. It was shown that the plasma characteristics could be controlled by geometrical and operational parameters of the experiment. Under most circumstances, continuous glow discharges were observed, but both the corona and/or the dielectric barrier discharge characteristics were observed depending on the position of the pin electrode. The plasma size and the rotational temperature were also varied by the parameters. The rotational temperature was between 300 and 490 K, being low enough to treat thermally sensitive materials

  20. Coronal mass ejections and disturbances in solar wind plasma parameters in relation with geomagnetic storms

    International Nuclear Information System (INIS)

    Verma, P L; Singh, Puspraj; Singh, Preetam

    2014-01-01

    Coronal Mass Ejections (CMEs) are the drastic solar events in which huge amount of solar plasma materials are ejected into the heliosphere from the sun and are mainly responsible to generate large disturbances in solar wind plasma parameters and geomagnetic storms in geomagnetic field. We have studied geomagnetic storms, (Dst ≤-75 nT) observed during the period of 1997-2007 with Coronal Mass Ejections and disturbances in solar wind plasma parameters (solar wind temperature, velocity, density and interplanetary magnetic field) .We have inferred that most of the geomagnetic storms are associated with halo and partial halo Coronal Mass Ejections (CMEs).The association rate of halo and partial halo coronal mass ejections are found 72.37 % and 27.63 % respectively. Further we have concluded that geomagnetic storms are closely associated with the disturbances in solar wind plasma parameters. We have determined positive co-relation between magnitudes of geomagnetic storms and magnitude of jump in solar wind plasma temperature, jump in solar wind plasma density, jump in solar wind plasma velocity and jump in average interplanetary magnetic field with co-relation co-efficient 0 .35 between magnitude of geomagnetic storms and magnitude of jump in solar wind plasma temperature, 0.19 between magnitude of geomagnetic storms and magnitude of jump in solar wind density, 0.34 between magnitude of geomagnetic storms and magnitude of jump in solar wind plasma velocity, 0.66 between magnitude of geomagnetic storms and magnitude of jump in average interplanetary magnetic field respectively. We have concluded that geomagnetic storms are mainly caused by Coronal Mass Ejections and disturbances in solar wind plasma parameters that they generate.

  1. Hidden parameters in the plasma deposition of microcrystalline silicon solar cells

    NARCIS (Netherlands)

    van den Donker, M.N.; Rech, B.; Schmitz, R.; Klomfass, J.; Dingemans, G.; Finger, F.; Houben, L.; Kessels, W.M.M.; Sanden, van de M.C.M.

    2007-01-01

    The effect of process parameters on the plasma deposition of µc-Si:H solar cells is reviewed in this article. Several in situ diagnostics are presented, which can be used to study the process stability as an additional parameter in the deposition process. The diagnostics were used to investigate the

  2. High-order harmonic generation in a laser plasma: a review of recent achievements

    International Nuclear Information System (INIS)

    Ganeev, R A

    2007-01-01

    A review of studies of high-order harmonic generation in plasma plumes is presented. The generation of high-order harmonics (up to the 101st order, λ = 7.9 nm) of Ti:sapphire laser radiation during the propagation of short laser pulses through a low-excited, low-ionized plasma produced on the surfaces of different targets is analysed. The observation of considerable resonance-induced enhancement of a single harmonic (λ = 61.2 nm) at the plateau region with 10 -4 conversion efficiency in the case of an In plume can offer some expectations that analogous processes can be realized in other plasma samples in the shorter wavelength range. Recent achievements of single-harmonic enhancement at mid- and end-plateau regions are discussed. Various methods for the optimization of harmonic generation are analysed, such as the application of the second harmonic of driving radiation and the application of prepulses of different durations. The enhancement of harmonic generation efficiency during the propagation of femtosecond pulses through a nanoparticle-containing plasma is discussed. (topical review)

  3. Mode transition of power dissipation and plasma parameters in an asymmetric capacitive discharge

    International Nuclear Information System (INIS)

    Lee, Soo-Jin; Lee, Hyo-Chang; Bang, Jin-young; Oh, Seung-Ju; Chung, Chin-Wook

    2013-01-01

    Electrical characteristics and plasma parameters were experimentally investigated in asymmetric capacitively coupled plasma with various argon gas pressures. At a low discharge current region, the transferred power to the plasma was proportional to the current, while the transferred power increased proportionally to square of the current at a high discharge current region. The mode transition of power dissipation occurred at the lower discharge current region with the high gas pressure. At the low radio-frequency power or low discharge current, the plasma density increased linearly with the discharge current, while at the high power or high discharge current, the rate of an increase in the plasma density depended on the gas pressures. A transition of the discharge resistance was also found when the mode transition of the power dissipation occurred. These changes in the electrical characteristics and the plasma parameters were mainly caused by the power dissipation mode transition from the plasma bulk to the sheath in the capacitive discharge with the asymmetric electrode, which has extremely high self-bias voltages. - Highlights: • Mode transition of the power dissipation in an asymmetrical capacitive discharge • Evolution of the discharge power, electrode voltage, and discharge impedance • Electron temperature and plasma density on the power dissipation mode transition

  4. Comparative Study of Plasma Parameters in Olive Ridley (Lepidochelys Olivacea and Hawksbill (Eretmochelys Imbricata During Nesting

    Directory of Open Access Journals (Sweden)

    A.Y.A. Alkindi

    2002-06-01

    Full Text Available The aim of this study is to investigate the role of plasma level parameters during nesting activity and provide data potentially useful to future studies on the dynamics of reproductive and stress hormones in the most endangered sea turtle species in the world. Plasma parameters in the sea turtles, olive ridley (Lipodochelys oliveacea and hawksbill (Eretmochelys imbricata from Masirah Island, Oman, were analyzed relative to nesting stress. To date, no study has been conducted on plasma parameter levels in sea turtles during nesting. Field observations were conducted under ideal temperature conditions. At the time of sampling, there was no significant difference for cloacal, sand, air or water temperature for the two species. Electrolytes (Cl¯, Ca++, K+, Na+ and Mg++, cholesterol, urea, uric acid and osmolarity were measured during nesting. Both species were observed to spend between 1.5 and 2.00 hours on the nesting grounds. Some had successful oviposition and completed all nesting phases, while others with incomplete nesting phases failed to oviposit their  eggs. Under both conditions, the turtles of both species had an exhaustive and stressful nesting exercise. Plasma parameter values, both intra-specifically and inter-specifically, were not significantly different for oviposited and non-oviposited turtles. This may indicate that both species have the same physiological adjustment relative to plasma parameters whether or not the turtles oviposited their eggs.

  5. Effect of plasma actuator control parameters on a transitional flow

    Science.gov (United States)

    Das Gupta, Arnob; Roy, Subrata

    2018-04-01

    This study uses a wall-resolved implicit large eddy simulation to investigate the effects of different surface dielectric barrier discharge actuator parameters such as the geometry of the electrodes, frequency, amplitude of actuation and thermal effect. The actuator is used as a tripping device on a zero-pressure gradient laminar boundary layer flow. It is shown that the standard linear actuator creates structures like the Tollmien-Schlichting wave transition. The circular serpentine, square serpentine and spanwise actuators have subharmonic sinuous streak breakdown and behave like oblique wave transition scenario. The spanwise and square actuators cause comparably faster transition to turbulence. The square actuator adds energy into the higher spanwise wavenumber modes resulting in a faster transition compared to the circular actuator. When the Strouhal number of actuation is varied, the transition does not occur for a value below 0.292. Higher frequencies with same amplitude of actuation lead to faster transition. Small changes (<4%) in the amplitude of actuation can have a significant impact on the transition location which suggests that an optimal combination of frequency and amplitude exists for highest control authority. The thermal bumps approximating the actuator heating only shows localized effects on the later stages of transition for temperatures up to 373 K and can be ignored for standard actuators operating in subsonic regimes.

  6. A study of plasma parameters in hollow cathode plasma jet in pulse regime

    Czech Academy of Sciences Publication Activity Database

    Kudrna, P.; Klusoň, J.; Leshkov, S.; Chichina, M.; Picková, I.; Hubička, Zdeněk; Tichý, M.

    2010-01-01

    Roč. 50, č. 9 (2010), s. 886-891 ISSN 0863-1042 R&D Projects: GA ČR GA202/09/0800 Institutional research plan: CEZ:AV0Z10100522 Keywords : thin-films * system * deposition * RF * nitride Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.006, year: 2010

  7. Temporal evolution of electron energy distribution function and plasma parameters in the afterglow of drifting magnetron plasma

    International Nuclear Information System (INIS)

    Seo, Sang-Hun; In, Jung-Hwan; Chang, Hong-Young

    2005-01-01

    The temporal behaviour of the electron energy distribution function (EEDF) and the plasma parameters such as electron density, electron temperature and plasma and floating potentials in a mid-frequency pulsed dc magnetron plasma are investigated using time-resolved probe measurements. A negative-voltage dc pulse with an average power of 160 W during the pulse-on period, a repetition frequency of 20 kHz and a duty cycle of 50% is applied to the cathode of a planar unbalanced magnetron discharge with a grounded substrate. The measured electron energy distribution is found to exhibit a bi-Maxwellian distribution, which can be resolved with the low-energy electron group and the high-energy tail part during the pulse-on period, and a Maxwellian distribution only with low-energy electrons as a consequence of initially rapid decay of the high-energy tail part during the pulse-off period. This characteristic evolution of the EEDF is reflected in the decay characteristics of the electron density and temperature in the afterglow. These parameters exhibit twofold decay represented by two characteristic decay times of an initial fast decay time τ 1 , and a subsequent slower decay time τ 2 in the afterglow when approximated with a bi-exponential function. While the initial fast decay times are of the order of 1 μs (τ T1 ∼ 0.99 μs and τ N1 ∼ 1.5 μs), the slower decay times are of the order of a few tens of microseconds (τ T2 ∼ 7 μs and τ N2 ∼ 40 μs). The temporal evolution of the plasma parameters are qualitatively explained by considering the formation mechanism of the bi-Maxwellian electron distribution function and the electron transports of these electron groups in bulk plasma

  8. Results from D-T experiments on TFTR and implications for achieving an ignited plasma

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Blanchard, W.

    1998-01-01

    Progress in the performance of tokamak devices has enable not only the production of significant bursts of fusion energy from deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR) and the Joint European Torus (JET) but, more importantly, the initial study of the physics of burning magnetically confined plasmas. As a result of the worldwide research on tokamaks, the scientific and technical issues for achieving an ignited plasma are better understood and the remaining questions more clearly defined. The principal research topics which have been studied on TFTR are transport, magnetohydrodynamic stability, and energetic particle confinement. The integration of separate solutions to problems in each of these research areas has also been of major interest. Although significant advances, such as the reduction of turbulent transport by means of internal transport barriers, identification of the theoretically predicted bootstrap current, and the study of the confinement of energetic fusion alpha-particles have been made, interesting and important scientific and technical issues remain. In this paper, the implications for the TFTR experiments for overcoming these remaining issues will be discussed

  9. Fast non-linear extraction of plasma equilibrium parameters using a neural network mapping

    International Nuclear Information System (INIS)

    Lister, J.B.; Schnurrenberger, H.

    1990-07-01

    The shaping of non-circular plasmas requires a non-linear mapping between the measured diagnostic signals and selected equilibrium parameters. The particular configuration of Neural Network known as the multi-layer perceptron provides a powerful and general technique for formulating an arbitrary continuous non-linear multi-dimensional mapping. This technique has been successfully applied to the extraction of equilibrium parameters from measurements of single-null diverted plasmas in the DIII-D tokamak; the results are compared with a purely linear mapping. The method is promising, and hardware implementation is straightforward. (author) 15 refs., 7 figs

  10. Fast non-linear extraction of plasma equilibrium parameters using a neural network mapping

    International Nuclear Information System (INIS)

    Lister, J.B.; Schnurrenberger, H.

    1991-01-01

    The shaping of non-circular plasmas requires a non-linear mapping between the measured diagnostic signals and selected equilibrium parameters. The particular configuration of neural network known as the multilayer perceptron provides a powerful and general technique for formulating an arbitrary continuous non-linear multi-dimensional mapping. This technique has been successfully applied to the extraction of equilibrium parameters from measurements of single-null diverted plasmas in the DIII-D tokamak; the results are compared with a purely linear mapping. The method is promising, and hardware implementation is straightforward. (author). 17 refs, 8 figs, 2 tab

  11. Effect of electrical stunning frequency on meat quality, plasma parameters, and protein solubility of broilers.

    Science.gov (United States)

    Huang, J C; Yang, J; Zhang, B H; Huang, M; Chen, K J; Xu, X L; Zhou, G H

    2017-08-01

    This study was designed to compare the effects of different stunning frequencies of pulsed direct current on meat quality of broilers. This was achieved by investigating plasma parameters, blood loss, carcass damage, meat water-holding capacity, meat color, meat shear value, muscle pH, and protein solubility. A total of 400 broilers was divided into 5 treatment groups and stunned with 500, 600, 700, 800, and 900 Hz at 15 V for 10 seconds. Blood samples were collected immediately after cutting the neck. Pectoralis major muscles were removed from the carcass after chilling and placed in ice. Breast muscle pH and meat color were determined at both 2 and 24 h postmortem. Drip loss, cooking loss, pressing loss, and cooked breast meat-shear values were determined at 24 h postmortem. Treatment at 500 and 900 Hz significantly increased (P meat color were not affected by stunning frequency. In the 500 and 900 Hz groups, the protein solubility and shear force values were significantly lower (P < 0.05) and drip loss was significantly higher (P < 0.05) than in the 700 Hz group. This study indicates that the waveform of the pulsed direct current is acceptable for stunning broilers at a stunning frequency of 700 Hz. © 2017 Poultry Science Association Inc.

  12. Production of a hot ion plasma at the lower hybrid resonance and measurement of its parameters

    International Nuclear Information System (INIS)

    Glagolev, V.M.; Dyubajlov, A.G.; Krivov, N.A.; Martynenko, V.V.; Skosyrev, Yu.V.

    1975-01-01

    Electromagnetic fields delayed along a magnetic field have been created within a plasma with the aid of a coil encircling the plasma column. When these waves were propagated transversely in relation to the magnetic field in a plasma with density rising along its radius, they were delayed in the direction of propagation. The amplitude and phase distributions of the electromagentic fields along the radius of the plasma column were measured at different moments in time. The existence of an absorption band of these waves within the plasma was detected. The absorption band was shifted towards the outer boundary from the plasma when plasma density was increased. By four independent methods it was established that the gas-kinetic pressure of the plasma, measured according to its diamagnetism, is determined by the ion component. It was found that the energy of electrons at right angles to the magnetic field is considerably less than that of the ions. The cause of limited heating was an increase in density and energy losses in the charge-exchange process. In order to improve vacuum conditions, the coil around the plasma was placed in a metallic chamber, and the UHF plasma source used in the original experiments was replaced by a hydride-film source. This made it possible to increase the internal energy of the plasma to 3x10 15 eV cm -3 at a density of (1-3)x10 12 cm -3 . The mean energy of atoms leaving the plasma at right angles to the magnetic field as a result of charge exchange reached 1 keV. The region of change in plasma parameters (density and magnetic field) for which heating was observed corresponded to the linear transformation theory. Non-linear effects could occur only in the first stage of heating, when the electric fields were strong, but plasma temperature was low. Heating efficiency was measured by a reflectometer installed in the coaxial line connecting the generator and the HF input coil to the plasma. The measurements showed that about 20% of the power

  13. The Influence of the Axial Magnetic Field Upon- the Coaxial Plasma Gun Parameters

    International Nuclear Information System (INIS)

    El-Aragi, G.M.; El-Demardash, A.

    2001-01-01

    This study concerns with the influence of an applied axial magnetic field upon the electrical parameters and on the brightness (luminance) of argon plasma. The brightness was measured by with a photomultiplier type of IP28 RCA. The experimental results are investigated with plasma gun device operated with argon gas at a pressure of 3.5 Torr. An axial time independent magnetic field with intensity of 550 G is introduced along the plasma current sheath axial region, within the annular space between the two coaxial electrodes. From the measurements of the discharge current I(t) and the voltage V(t), the electrical discharge parameters of the plasma gun device and the plasma current sheath implosion velocity are estimated, in normal mode of plasma gun operation and in the mode of presence external axial magnetic field. A comparison between these two modes is studied. It was found that the thickness of skin-layer δ about 0.01 cm and the wavelength λ, of the perturbation about 1.3 cm i.e. the instability has been satisfied. The growth rate γ of the instability about 10 6 sec -1 . (author)

  14. Investigation of shock compressed plasma parameters by interaction with magnetic field

    International Nuclear Information System (INIS)

    Dudin, S. V.; Fortov, V. E.; Gryaznov, V. K.; Mintsev, V. B.; Shilkin, N. S.; Ushnurtsev, A. E.

    1998-01-01

    The Hall effect parameters in shock compressed air, helium and xenon have been estimated and results of experiments with air and helium plasma are presented. Explosively driven shock tubes were used for the generation of strong shock waves. To obtain magnetic field a solenoid was winded over the shock tube. Calculations of dense shock compressed plasma parameters were carried out to plan the experiments. In the experiments with the magnetic field of ∼5 T it was found, that air plasma slug was significantly heated by the whirlwind electrical field. The reflected shock waves technique was used in the experiments with helium. Results on measurements of electrical conductivity and electron concentration of helium are presented

  15. Excellent Silicon Surface Passivation Achieved by Industrial Inductively Coupled Plasma Deposited Hydrogenated Intrinsic Amorphous Silicon Suboxide

    Directory of Open Access Journals (Sweden)

    Jia Ge

    2014-01-01

    Full Text Available We present an alternative method of depositing a high-quality passivation film for heterojunction silicon wafer solar cells, in this paper. The deposition of hydrogenated intrinsic amorphous silicon suboxide is accomplished by decomposing hydrogen, silane, and carbon dioxide in an industrial remote inductively coupled plasma platform. Through the investigation on CO2 partial pressure and process temperature, excellent surface passivation quality and optical properties are achieved. It is found that the hydrogen content in the film is much higher than what is commonly reported in intrinsic amorphous silicon due to oxygen incorporation. The observed slow depletion of hydrogen with increasing temperature greatly enhances its process window as well. The effective lifetime of symmetrically passivated samples under the optimal condition exceeds 4.7 ms on planar n-type Czochralski silicon wafers with a resistivity of 1 Ωcm, which is equivalent to an effective surface recombination velocity of less than 1.7 cms−1 and an implied open-circuit voltage (Voc of 741 mV. A comparison with several high quality passivation schemes for solar cells reveals that the developed inductively coupled plasma deposited films show excellent passivation quality. The excellent optical property and resistance to degradation make it an excellent substitute for industrial heterojunction silicon solar cell production.

  16. Effect of Mucuna pruriens on semen profile and biochemical parameters in seminal plasma of infertile men.

    Science.gov (United States)

    Ahmad, Mohammad Kaleem; Mahdi, Abbas Ali; Shukla, Kamla Kant; Islam, Najmul; Jaiswar, Shyam Pyari; Ahmad, Sohail

    2008-09-01

    To investigate the impact of Mucuna pruriens seeds on semen profiles and biochemical levels in seminal plasma of infertile men. Prospective study. Departments of Biochemistry and Obstetrics and Gynecology, King George's Medical University, Lucknow, India. Sixty normal healthy fertile men (controls) and 60 men undergoing infertility screening. High-performance liquid chromatography assay procedure for quantitation of vitamin A and E in seminal plasma. Biochemical parameters in seminal plasma, namely lipids, fructose, and vitamin C, were estimated by standard spectrophotometric procedures. Before and after the treatment, seminal plasma lipid profile, lipid peroxide, fructose, and antioxidant vitamin levels were measured. Treatment with M. pruriens significantly inhibited lipid peroxidation, elevated spermatogenesis, and improved sperm motility. Treatment also recovered the levels of total lipids, triglycerides, cholesterol, phospholipids, and vitamin A, C, and E and corrected fructose in seminal plasma of infertile men. Treatment with M. pruriens increased sperm concentration and motility in all the infertile study groups. Oligozoospermic patients recovered sperm concentration significantly, but sperm motility was not restored to normal levels in asthenozoospermic men. Furthermore, in the seminal plasma of all the infertile groups, the levels of lipids, antioxidant vitamins, and corrected fructose were recovered after a decrease in lipid peroxides after treatment. The present study is likely to open new vistas on the possible role of M. pruriens seed powder as a restorative and invigorating agent for infertile men.

  17. Scaling study of edge plasma parameters using a multi-device database

    International Nuclear Information System (INIS)

    Tsui, H.Y.W.; Miner, W.H.; Wootton, A.J.

    1995-01-01

    A database consisting of edge equilibrium, turbulence and transport related plasma parameters has been compiled. Scaling laws for edge density, electron temperature, and radial particle flux are derived in an initial study using a subset of data obtained from tokamaks Phaedrus-T, Tokamak de Varennes, TEXT and TEXT-U. A comparison of edge particle transport in divertor and limiter plasmas shows that the magnetic topology of a separatrix or a divertor improves particle confinement. The particle diffusion coefficient varies radially in a manner opposite to that of Bohm diffusion. ((orig.))

  18. The Diagnosis of Plasma Parameters in Surface Alloying Technique by Optical Emission Spectrometry

    International Nuclear Information System (INIS)

    Fu Yabo; Zhang Yuefei; Chen Qiang; Zhang Guangqiu; Gao Yuan; Wang Jianzhong; Kui Xiaoyun

    2006-01-01

    Electron density (Ne) in a glow discharge plasma for the surface alloying technique is diagnosed by optical emission spectrometry (OES). With CH 4 as the feeding gas, Ne is obtained by comparing the Hβ spectrum according to the Stark broadening effect. It is noticed that Ne varies with the working pressures (30 Pa to 70 Pa) and cathode voltages (500 V to 1000 V), respectively. Due to an abnormal glow discharge, Ne is between 1.71x10 15 /cm 3 to 6.64x10 15 /cm 3 and increases rapidly with working gas pressures and cathode voltages. The results show that OES is a useful method to measure the plasma parameters in a surface alloying glow discharge plasma

  19. Identification of Plasma Parameters and Optimization of Magnetic Sensors in the Superconducting Steady-State Tokamak-1 Using Neural Networks

    International Nuclear Information System (INIS)

    Sengupta, A.; Ranjan, P.

    2001-01-01

    In this paper, we examine the possibility of using a multilayered feedforward neural network to extract tokamak plasma parameters from magnetic measurements as an improvement over the traditional methodology of function parametrization. It is also used to optimize the number and locations of the magnetic diagnostics designed for the tokamak. This work has been undertaken with the specific purpose of application of the neural network technique to the newly designed (and currently under fabrication) Superconducting Steady-State Tokamak-1 (SST-1). The magnetic measurements will be utilized to achieve real-time control of plasma shape, position, and some global profiles. A trained neural network is tested, and the results of parameter identification are compared with function parametrization. Both techniques appear well suited for the purpose, but a definite improvement with neural networks is observed. Although simulated measurements are used in this work, confidence regarding the network performance with actual experimental data is ensured by testing the network's noise tolerance with Gaussian noise of up to 10%. Finally, three possible methods of ranking the diagnostics in decreasing order of importance are suggested, and the neural network is used to optimize the number and locations of the magnetic sensors designed for SST-1. The results from the three methods are compared with one another and also with function parametrization. Magnetic probes within the plasma-facing side of the outboard limiter have been ranked high. Function parametrization and one of the neural network methods show a distinct tendency to favor the probes in the remote regions of the vacuum vessel, proving the importance of redundancy. Fault tolerance of the optimized network is tested. The results obtained should, in the long run, help in the decision regarding the final effective set of magnetic diagnostics to be used in SST-1 for reconstruction of the control parameters

  20. Qualitative Parameters for Evaluation Procedures of Non-Formal and Informal Learning Achievements

    Science.gov (United States)

    Stasiunaitiene, Egle; Kaminskiene, Lina

    2009-01-01

    The article introduces evaluation principles of non-formal and informal learning that determine the quality of evaluation, describes stages of the evaluation procedure, differentiates their qualitative parameters and defines their criteria and indicators. It also brings in the discussion that consideration of qualitative parameters for the…

  1. Relationship of zinc concentrations in blood and seminal plasma with various semen parameters in infertile subjects

    International Nuclear Information System (INIS)

    Ali, H.; Ahmed, M.; Baig, M.; Ali, M.

    2007-01-01

    To find out relationship of zinc concentrations in blood and seminal plasma with various semen parameters between fertile and infertile men. (JPMC), Karachi and Department of Biochemistry. Basic Medical Sciences Institute, JPMC, Karachi. Fifty eight primary infertile male subjects, without any treatment, who had regular unprotected intercourse for at least 12 months without conception with their partners, aged 20-40 years, were selected from Infertility Clinic Jinnah Postgraduate Medical Center, Karachi. After semen analyses they were grouped as, oligospermic (30), and azoospermic (28). Twenty five known fertile male selected from general population and after semen analysis were taken as normospermic control group. Semen analyzed according to WHO criteria. Serum and seminal plasma zinc were estimated by 5Br. PAPS Colorimetric method. This study showed significant difference in serum and seminal zinc levels in normospermic, oligospermic (p<0.05) and azoospermic (p<0.005). Seminal plasma zinc showed a positive correlation with sperm count and negative with sperm motility in normospermic and oligospermic and negative correlation with volume, pH, WBC concentration in all three groups. There was no correlation found with sperm morphology. On the basis of the findings of this study and those of other reports, zinc may contribute to fertility through its significant effects on various semen parameters. It seems that the estimation of seminal plasma zinc may help in investigation and treatment of infertile males. (author)

  2. [Measurement of plasma parameters in cluster hexagon pattern discharge by optical emission spectrum].

    Science.gov (United States)

    Dong, Li-Fang; Shen, Zhong-Kai; Li, Xin-Chun; Liu, Liang; Lu, Ning; Shang, Jie

    2012-09-01

    The cluster hexagon pattern was obtained in a dielectric barrier discharge in air/argon for the first time. Three plasma parameters, i. e. the molecular vibrational temperature, the molecular rotational temperature and the average electron energy of individual cluster in cluster hexagon pattern discharge, were studied by changing the air content. The molecular vibrational temperature and the molecular rotational temperature were calculated using the second positive band system of nitrogen molecules (C 3IIu --> B 3IIg) and the first negative band system of nitrogen molecular ions (B 2Sigma(u)+ --> Chi2 Sigma(g)+). The relative intensities of the first negative system of nitrogen molecular ions (391. 4 nm) and nitrogen molecules emission spectrum line (337.1 nm) were analyzed for studying the variations of the electron energy. It was found that the three plasma parameters of individual cluster in cluster hexagon pattern increase with air content increasing from 16% to 24%.

  3. Effect of different parameters governing the stability of drift wave in a magnetised plasma

    International Nuclear Information System (INIS)

    Elashkar, F.F.

    1990-01-01

    Influence of the governing parameters, such as electron drift parallel speed, parallel wave length, electron-neutral and ion-neutral collision frequencies, electron temperature and magnetic field, on the stability of drift wave in a magnetized plasma has been studied experimentally and theoretically using a full numerical solution of the exact equation. Drift wave has been excited by a positively biased grid; at a threshold grid potential secondary excitation and ionisation processes take place in the ejected beam of plasma. Effect of the applied magnetic field on the probability of these processes is discussed. Grid positive potential, electron-neutral collision, parallel wave length, electron temperature and speed are found to be destabilizing, While ion neutral collision is stabilizing. Using a new parameter β, the effect of magnetic field is investigated and it is destabilizing only upto a certain limit. (author). 11 figs., 21 refs

  4. Long-time integrator for the study on plasma parameter fluctuations

    International Nuclear Information System (INIS)

    Zalkind, V.M.; Tarasenko, V.P.

    1975-01-01

    A device measuring the absolute value (x) of a fluctuating quantity x(t) averaged over a large number of realizations is described. The specific features of the device are the use of the time selector (Δ t = 50 μs - 1 ms) and the large time integration constant (tau = 30 hrs). The device is meant for studying fluctuations of parameters of a pulse plasma with a small repetition frequency

  5. The scaling of edge parameters in jet with plasma input power

    International Nuclear Information System (INIS)

    Erents, S.K.; McCracken, G.M.; Harbour, P.J.; Clement, S.; Summers, D.D.R.; Tagle, J.A.; Kock, L. de

    1989-01-01

    The scaling of edge parameters of density and temperature with central density and ohmic power in JET has been presented previously for the discrete limiter geometry and more recently for the new belt limiter configuration. However, the scaling with plasma current (I p ) is difficult to interpret because varying I p does not only change the input power but also the safety factor qs and consequently the SOL thickness. The use of additional heating at constant current allows more direct observation of the effects of changing heating power. In this paper we present data in which the plasma input power is increased by ICRH, (Pt<20MW), using a 3MA target plasma, and compare data for different plasma currents using discrete and belt limiter geometries. Edge data is presented from Langmuir probes in tiles at the top of the torus, when the tokamak is operated in single null magnetic separatrix (divertor) mode, as well as for probes in the main plasma boundary to contrast these data with limiter data. (author) 3 refs., 4 figs

  6. Some parameters of uranium hexafluoride plasma produced by products of nuclear reaction

    International Nuclear Information System (INIS)

    Batyrbekov, G.A.; Belyakova, Eh.A.

    1996-01-01

    The probe experimental results of investigation of uranium hexafluoride plasma produced in the centre of nuclear reactor core were demonstrated. Study of uranium hexafluoride plasma is continued by the following reasons: a possibility of U F 6 utilization as nuclear fuel, the utilization of U F 6 as volume source o ionization, search of active laser media compatible with U F 6 that is complicated by lack of constant rates data for most of plasma-chemical reactions with U F 6 and his dissociation products. Cylindrical probe volt-ampere characteristics (VAC) measured in U F 6 plasma at pressure 20 Torr and different thermal neutron fluxes and have following features: -firstly, it is possible to choose a linear part in the field of small positive potentials of probe (0-1) V; - secondary, ion branches of VAC have typical break which current of satiation corresponds to; -thirdly, probe VAC measured at small values of thermal neutron flux density are symmetrical. Diagnostics approaches were used for interpretation VAC of probe. The values of satiation current and linear part of electron branch were calculated, and such plasma parameters as conductivity, diffusion coefficient values of positive and negative ions were determined. The resonance recharge cross section was estimated on diffusion coefficient value

  7. Analysis of time-dependent effects when operating nested-well plasma traps for achieving antihydrogen recombination

    International Nuclear Information System (INIS)

    Chang Yongbin; Dolliver, D. D.; Ordonez, C. A.

    1999-01-01

    In the work reported, time-dependent effects are considered which affect the prospect of getting two oppositely signed plasmas to overlap the same region while trapped within a solenoidal magnetic field. Parameters that are relevant to future experimental attempts at producing cold antihydrogen atoms using nested-well plasma traps are considered. It is found that the timescale over which an overlap remains, without changing the electrode voltages, can be much larger than the timescale over which the overlap plasma recombines. Hence, it does not appear necessary to use time-dependent electrode voltages to maintain the overlap while antihydrogen atoms are being produced

  8. The LXCat project: Electron scattering cross sections and swarm parameters for low temperature plasma modeling

    International Nuclear Information System (INIS)

    Pancheshnyi, S.; Biagi, S.; Bordage, M.C.; Hagelaar, G.J.M.; Morgan, W.L.; Phelps, A.V.; Pitchford, L.C.

    2012-01-01

    Graphical abstract: LXCat is an open-access website containing data needed for low temperature plasma modeling as well as on-line tools useful for their manipulation. Highlights: ► LXCat: an open-access website with data for low temperature plasma modeling. ► Contains compilations of electron scattering cross sections and transport data. ► Data from different contributors for many neutral, ground-state species. ► On-line tools for browsing, plotting, up/downloading data. ► On-line Boltzmann solver for calculating electron swarm parameters. - Abstract: LXCat is a dynamic, open-access, website for collecting, displaying, and downloading ELECtron SCATtering cross sections and swarm parameters (mobility, diffusion coefficient, reaction rates, etc.) required for modeling low temperature, non-equilibrium plasmas. Contributors set up individual databases, and the available databases, indicated by the contributor’s chosen title, include mainly complete sets of electron-neutral scattering cross sections, although the option for introducing partial sets of cross sections exists. A database for measured swarm parameters is also part of LXCat, and this is a growing activity. On-line tools include options for browsing, plotting, and downloading cross section data. The electron energy distribution functions (edfs) in low temperature plasmas are in general non-Maxwellian, and LXCat provides an option for execution of an on-line Boltzmann equation solver to calculate the edf in homogeneous electric fields. Thus, the user can obtain electron transport and rate coefficients (averages over the edfs) in pure gases or gas mixtures over a range of values of the reduced electric fields strength, E/N, the ratio of the electric field strength to the neutral density, using cross sections from the available databases. New contributors are welcome and anyone wishing to create a database and upload data can request a username and password. LXCat is part of a larger, community

  9. Correlation of Magnetic Fields with Solar Wind Plasma Parameters at 1AU

    Science.gov (United States)

    Shen, F.

    2017-12-01

    The physical parameters of the solar wind observed in-situ near 1AU have been studied for several decades, and relationships between them, such as the positive correlation between the solar wind plasma temperature T and velocity V, and the negative correlation between density N and velocity V, are well known. However, the magnetic field intensity does not appear to be well correlated with any individual plasma parameter. In this paper, we discuss previously under-reported correlations between B and the combined plasma parameters √NV2 as well as between B and √NT. These two correlations are strong during the periods of corotating interaction regions and high speed streams, moderate during intervals of slow solar wind, and rather poor during the passage of interplanetary coronal mass ejections. The results indicate that the magnetic pressure in the solar wind is well correlated both with the plasma dynamic pressure and the thermal pressure. Then, we employ a 3D MHD model to simulate the formation of the relationships between the magnetic strength B and √NV2 as well as √NT observed at 1AU. The inner boundary condition is derived by empirical models, with the magnetic field and density are optional. Five kinds of boundary conditions at the inner boundary of heliosphere are tested. In the cases that the magnetic field is related to speed at the inner boundary, the correlation coefficients between B and √NV2 as well as between B and √NT are even higher than that in the observational results. At 1AU the simulated radial magnetic field shows little latitude dependence, which matches the observation of Ulysses. Most of the modeled characters in these cases are closer to observation than others. This inner boundary condition may more accurately characterize Sun's magnetic influence on the heliosphere. The new input may be able to improve the simulation of CME propagation in the inner heliosphere and the space weather forecasting.

  10. The Plasma Parameters and Geometry of Cool and Warm Active Region Loops

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Haixia; Li, Bo; Huang, Zhenghua; Xia, Lidong; Fu, Hui; Mou, Chaozhou [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, 264209 Shandong (China); Madjarska, Maria S.; Wiegelmann, Thomas [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077, Göttingen (Germany)

    2017-06-10

    How the solar corona is heated to high temperatures remains an unsolved mystery in solar physics. In the present study we analyze observations of 50 whole active region loops taken with the Extreme-ultraviolet Imaging Spectrometer on board the Hinode satellite. Eleven loops were classified as cool loops (<1 MK) and 39 as warm loops (1–2 MK). We study their plasma parameters, such as densities, temperatures, filling factors, nonthermal velocities, and Doppler velocities. We combine spectroscopic analysis with linear force-free magnetic field extrapolation to derive the 3D structure and positioning of the loops, their lengths and heights, and the magnetic field strength along the loops. We use density-sensitive line pairs from Fe xii, Fe xiii, Si x, and Mg vii ions to obtain electron densities by taking special care of intensity background subtraction. The emission measure loci method is used to obtain the loop temperatures. We find that the loops are nearly isothermal along the line of sight. Their filling factors are between 8% and 89%. We also compare the observed parameters with the theoretical Rosner–Tucker–Vaiana (RTV) scaling law. We find that most of the loops are in an overpressure state relative to the RTV predictions. In a follow-up study, we will report a heating model of a parallel-cascade-based mechanism and will compare the model parameters with the loop plasma and structural parameters derived here.

  11. Reconstruction of the ion plasma parameters from the current measurements: mathematical tool

    Directory of Open Access Journals (Sweden)

    E. Séran

    Full Text Available Instrument d’Analyse du Plasma (IAP is one of the instruments of the newly prepared ionospheric mission Demeter. This analyser was developed to measure flows of thermal ions at the altitude of ~ 750 km and consists of two parts: (i retarding potential analyser (APR, which is utilised to measure the energy distribution of the ion plasma along the sensor look direction, and (ii velocity direction analyser (ADV, which is used to measure the arrival angle of the ion flow with respect to the analyser axis. The necessity to obtain quick and precise estimates of the ion plasma parameters has prompted us to revise the existing mathematical tool and to investigate different instrumental limitations, such as (i finite angular aperture, (ii grid transparency, (iii potential depression in the space between the grid wires, (iv losses of ions during their passage between the entrance diaphragm and the collector. Simple analytical expressions are found to fit the currents, which are measured by the APR and ADV collectors, and show a very good agreement with the numerical solutions. It was proven that the fitting of the current with the model functions gives a possibility to properly resolve even minor ion concentrations and to find the arrival angles of the ion flow in the multi-species plasma. The discussion is illustrated by an analysis of the instrument response in the ionospheric conditions which are predicted by the International Reference Ionosphere (IRI model.

    Key words. Ionosphere (plasma convection; instruments and techniques – Space plasma physics (experimental and mathematical techniques

  12. Reconstruction of the ion plasma parameters from the current measurements: mathematical tool

    Directory of Open Access Journals (Sweden)

    E. Séran

    2003-05-01

    Full Text Available Instrument d’Analyse du Plasma (IAP is one of the instruments of the newly prepared ionospheric mission Demeter. This analyser was developed to measure flows of thermal ions at the altitude of ~ 750 km and consists of two parts: (i retarding potential analyser (APR, which is utilised to measure the energy distribution of the ion plasma along the sensor look direction, and (ii velocity direction analyser (ADV, which is used to measure the arrival angle of the ion flow with respect to the analyser axis. The necessity to obtain quick and precise estimates of the ion plasma parameters has prompted us to revise the existing mathematical tool and to investigate different instrumental limitations, such as (i finite angular aperture, (ii grid transparency, (iii potential depression in the space between the grid wires, (iv losses of ions during their passage between the entrance diaphragm and the collector. Simple analytical expressions are found to fit the currents, which are measured by the APR and ADV collectors, and show a very good agreement with the numerical solutions. It was proven that the fitting of the current with the model functions gives a possibility to properly resolve even minor ion concentrations and to find the arrival angles of the ion flow in the multi-species plasma. The discussion is illustrated by an analysis of the instrument response in the ionospheric conditions which are predicted by the International Reference Ionosphere (IRI model.Key words. Ionosphere (plasma convection; instruments and techniques – Space plasma physics (experimental and mathematical techniques

  13. Plasma sheath dynamics and parameters in focus and defocus conditions. Vol. 2

    International Nuclear Information System (INIS)

    Masoud, M.M.; Soliman, H.M.; El-Aragi, G.M.

    1996-01-01

    The study deals with the effect of the inner electrode polarity on the dynamic behaviour and parameters of plasma sheath in a coaxial discharge. The experimental investigations presented here were carried out in a coaxial plasma focus discharge device of mather geometry. It consisted of coaxial stainless steel hollow cylindrical electrodes with inner electrode 18.2 cm length and outer-electrode 31.5 cm length. The diameter of the inner and outer electrodes are 3.2 cm and 6.6 cm, respectively. The two electrodes are separated by a teflon disc at the breech. The outer electrode muzzle is connected to stainless steel expansion chamber of 23 cm length and 17 cm diameter. The discharge takes place in hydrogen gas with a base pressure of 1 torr. The experiments were conducted with 10 kV bank voltage, which corresponds to 100 K A peak discharge current. By using a double electric probe, It was found that the plasma electron density was higher near the negative electrode. Investigations using a miniature rogovsky coil have shown that, the radial and azimuthal current density increased with radial distance from negative electrode to positive electrode. The shape and the axial velocity of plasma sheath were measured using a magnetic probe. The experimental results indicate that, the plasma is thick near the negative electrode, in both cases of the outer or the inner electrode. Also it has been found that the axial plasma sheath velocity reaches its maximum value at the muzzle for positive and negative inner electrode. The magnitude of maximum axial velocity reaches 1.7 x 10 60 cm/s for positive inner electrode and decreased by 25% for negative inner electrode further investigations revealed that on interchanging the polarity from normal operation (positive inner electrode), it was found that with negative inner electrode the soft x-ray emission intensity dropped by three orders of magnitude from that with positive inner electrode. 9 figs

  14. Plasma sheath dynamics and parameters in focus and defocus conditions. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Masoud, M M; Soliman, H M; El-Aragi, G M [Plasma Physics and Nuclear Fusion Department, Nuclear Research Centre, Atomic Energy Aurhority, Cairo (Egypt)

    1996-03-01

    The study deals with the effect of the inner electrode polarity on the dynamic behaviour and parameters of plasma sheath in a coaxial discharge. The experimental investigations presented here were carried out in a coaxial plasma focus discharge device of mather geometry. It consisted of coaxial stainless steel hollow cylindrical electrodes with inner electrode 18.2 cm length and outer-electrode 31.5 cm length. The diameter of the inner and outer electrodes are 3.2 cm and 6.6 cm, respectively. The two electrodes are separated by a teflon disc at the breech. The outer electrode muzzle is connected to stainless steel expansion chamber of 23 cm length and 17 cm diameter. The discharge takes place in hydrogen gas with a base pressure of 1 torr. The experiments were conducted with 10 kV bank voltage, which corresponds to 100 K A peak discharge current. By using a double electric probe, It was found that the plasma electron density was higher near the negative electrode. Investigations using a miniature rogovsky coil have shown that, the radial and azimuthal current density increased with radial distance from negative electrode to positive electrode. The shape and the axial velocity of plasma sheath were measured using a magnetic probe. The experimental results indicate that, the plasma is thick near the negative electrode, in both cases of the outer or the inner electrode. Also it has been found that the axial plasma sheath velocity reaches its maximum value at the muzzle for positive and negative inner electrode. The magnitude of maximum axial velocity reaches 1.7 x 10{sup 60} cm/s for positive inner electrode and decreased by 25% for negative inner electrode further investigations revealed that on interchanging the polarity from normal operation (positive inner electrode), it was found that with negative inner electrode the soft x-ray emission intensity dropped by three orders of magnitude from that with positive inner electrode. 9 figs.

  15. Dependence of electron beam instability growth rates on the beam-plasma system parameters

    International Nuclear Information System (INIS)

    Strangeway, R.J.

    1982-01-01

    Electron beam instabilites are studied by using a simple model for an electron beam streaming through a cold plasma, the beam being of finite width perpendicular to the ambient magnetic field. Through considerations of finite geometry and the coldness of the beam and background plasma, an instability similar to the two stream instability is assumed to be the means for wave growth in the system. Having found the maximum growth rate for one set of beam-plasma system parameters, this maximum growth rate is traced as these parameters are varied. The parameters that describe the system are the beam velocity (v/sub b/), electron gyrofrequency to ambient electron plasma frequency ratio (Ω/sub e//ω/sub p/e), the beam to background number density ratio (n/sub b//n/sub a/), and the beam width (a). When Ω/sub e//ω/sub p/e>1, a mode with Ω/sub e/<ω<ω/sub u/hr is found to be unstable, where Ω is the wave frequency and ω/sub u/hr is the upper hybrid resonance frequency. For low values of n/sub b//n/sub a/ and Ω/sub e/<ω/sub p/e, this mode is still present with ω/sub p/e<ω<ω/sub u/hr. If the beam density is large, n/sub b//n/sub a/approx. =1, the instability occures for frequencies just above the electron gyrofrequency. This mode may well be that observed in laboratory plasma before the system undergoes the beam-plasma discharge. There is another instability present, which occurs for ωapprox. =ω/sub p/e. The growth rates for this mode, which are generally larger than those found for the ωapprox. =ωuhr mode, are only weakly dependent on Ω/sub d//ω/sub p/e. That this mode is not always observed in the laboratory implies that some factors not considered in the present theory suppress this mode, specifically, finite beam length

  16. Effects of spray parameters on the microstructure and property of Al2O3 coatings sprayed by a low power plasma torch with a novel hollow cathode

    International Nuclear Information System (INIS)

    Li Changjiu; Sun Bo

    2004-01-01

    Al 2 O 3 coating is deposited using a low power plasma torch with a novel hollow cathode through axial powder injection under a plasma power up to several kilowatts. The effects of the main processing parameters including plasma arc power, operating gas flow and spray distance on particle velocity during spraying, and the microstructure and property of the coating are investigated. The microstructure of the Al 2 O 3 coating is examined using optical microscopy and X-ray diffraction analysis. The property of the coating is characterized by dry rubber wheel abrasive wear test. The velocity of in-flight particle is measured using a velocity/temperature measurement system for spray particle based on thermal radiation from the particle. The dependency of the microstructure and property of the coating on spray particle conditions are examined by comparing the particle velocity, and microstructure and abrasive wear weight loss of subsequent coating deposited by low power plasma spray with those of the coating by conventional plasma spray at a power one order higher. X-ray diffraction analysis of the coating revealed that Al 2 O 3 particles during low power plasma spraying reach to sufficiently melting state prior to impact on the substrate with a velocity comparable to that in conventional plasma spraying. The experiment results have shown that processing parameters have significant influence on the particle conditions and performance of deposited Al 2 O 3 coating. The coating of comparable microstructure and properties to that deposited by conventional plasma spray can be produced under a power one order lower. From the present study, it can be suggested that a comparable coating can be produced despite plasma power level if the comparable particle velocity and molten state are achieved

  17. Rocket measurements within a polar cap arc - Plasma, particle, and electric circuit parameters

    Science.gov (United States)

    Weber, E. J.; Ballenthin, J. O.; Basu, S.; Carlson, H. C.; Hardy, D. A.; Maynard, N. C.; Kelley, M. C.; Fleischman, J. R.; Pfaff, R. F.

    1989-01-01

    Results are presented from the Polar Ionospheric Irregularities Experiment (PIIE), conducted from Sondrestrom, Greenland, on March 15, 1985, designed for an investigation of processes which lead to the generation of small-scale (less than 1 km) ionospheric irregularities within polar-cap F-layer auroras. An instrumented rocket was launched into a polar cap F layer aurora to measure energetic electron flux, plasma, and electric circuit parameters of a sun-aligned arc, coordinated with simultaneous measurements from the Sondrestrom incoherent scatter radar and the AFGL Airborne Ionospheric Observatory. Results indicated the existence of two different generation mechanisms on the dawnside and duskside of the arc. On the duskside, parameters are suggestive of an interchange process, while on the dawnside, fluctuation parameters are consistent with a velocity shear instability.

  18. Optimization of process parameters for spark plasma sintering of nano structured SAF 2205 composite

    Directory of Open Access Journals (Sweden)

    Samuel Ranti Oke

    2018-04-01

    Full Text Available This research optimized spark plasma sintering (SPS process parameters in terms of sintering temperature, holding time and heating rate for the development of a nano-structured duplex stainless steel (SAF 2205 grade reinforced with titanium nitride (TiN. The mixed powders were sintered using an automated spark plasma sintering machine (model HHPD-25, FCT GmbH, Germany. Characterization was performed using X-ray diffraction and scanning electron microscopy. Density and hardness of the composites were investigated. The XRD result showed the formation of FeN0.068. SEM/EDS revealed the presence of nano ranged particles of TiN segregated at the grain boundaries of the duplex matrix. A decrease in hardness and densification was observed when sintering temperature and heating rate were 1200 °C and 150 °C/min respectively. The optimum properties were obtained in composites sintered at 1150 °C for 15 min and 100 °C/min. The composite grades irrespective of the process parameters exhibited similar shrinkage behavior, which is characterized by three distinctive peaks, which is an indication of good densification phenomena. Keywords: Spark plasma sintering, Duplex stainless steel (SAF 2205, Titanium nitride (TiN, Microstructure, Density, Hardness

  19. DYNAMIC OF CHANGES OF BLOOD PLASMA ENERGY METABOLISM PARAMETERS IN SUCKLING COWS DURING CALVING INTERVAL

    Directory of Open Access Journals (Sweden)

    Ales Pavlik

    2015-02-01

    Full Text Available In this study, effect of environmental condition changes during gazing period on energy metabolism parameters was investigated. Totally 40 Aberdeen Angus cows were selected for observation. Calving all of cows was situated into March. The feeding ration for the animals was comprised by pasture during the grazing period and corn silage, hay and granulated distiller’s grains during the winter period. At average age 9 days before calving, and subsequently 10, 81, 151, 189 and 273 days after calving, blood was sampled and analysed for glucose and NEFA (non-esterified fatty acid concentrations on KONELAB T20xt automatic analyser (Thermo Fisher Scientific, Finland and currently available commercial kits (Biovendor-Laboratorni medicina, Czech Republic. A rapid increase (p < 0.05 of glucose concentration was detected in blood plasma of cows in period before calving to 81 days post partum. Average value of glucose concentration at 273 days postpartum was significant (p < 0.05 lower comparing to day 189. The highest concentrations of NEFA in blood plasma of cows were found at 10 day postpartum. After that, during the persisted higher temperature period the NEFA concentration decreased significantly (p < 0.01 till 189 days postpartum. At the end of monitored period concentration of NEFA in blood plasma significantly decreased (p < 0.05. Changes of hot and cold season during the grazing period probably according to forage quality and had significant effects on blood plasma NEFA and glucose concentrations.

  20. Achieving a long-lived high-beta plasma state by energetic beam injection

    Science.gov (United States)

    Guo, H. Y.; Binderbauer, M. W.; Tajima, T.; Milroy, R. D.; Steinhauer, L. C.; Yang, X.; Garate, E. G.; Gota, H.; Korepanov, S.; Necas, A.; Roche, T.; Smirnov, A.; Trask, E.

    2015-04-01

    Developing a stable plasma state with high-beta (ratio of plasma to magnetic pressures) is of critical importance for an economic magnetic fusion reactor. At the forefront of this endeavour is the field-reversed configuration. Here we demonstrate the kinetic stabilizing effect of fast ions on a disruptive magneto-hydrodynamic instability, known as a tilt mode, which poses a central obstacle to further field-reversed configuration development, by energetic beam injection. This technique, combined with the synergistic effect of active plasma boundary control, enables a fully stable ultra-high-beta (approaching 100%) plasma with a long lifetime.

  1. The effect of processing parameters on plasma sprayed beryllium for fusion applications

    International Nuclear Information System (INIS)

    Castro, R.G.; Stanek, P.W.; Jacobson, L.A.; Cowgill, D.F.; Snead, L.L.

    1993-01-01

    Plasma spraying is being investigated as a potential coating technique for applying thin (0.1--5mm) layers of beryllium on plasma facing surfaces of blanket modules in ITER and also as an in-situ repair technique for repairing eroded beryllium surfaces in high heat flux divertor regions. High density spray deposits (>98% of theoretical density) of beryllium will be required in order to maximize the thermal conductivity of the beryllium coatings. A preliminary investigation was done to determine the effect of various processing parameters (particle size, particle morphology, secondary gas additions and reduced chamber pressure) on the as-deposited density of beryllium. The deposits were made using spherical beryllium feedstock powder which was produced by centrifugal atomization at Los Alamos National Laboratory (LANL). Improvements in the as-deposited densities and deposit efficiencies of the beryllium spray deposits will be discussed along with the corresponding thermal conductivity and outgassing behavior of these deposits

  2. Some necessary parameters for a critical velocity interaction between the ionospheric plasma and a xenon cloud

    International Nuclear Information System (INIS)

    Axnaes, I.

    1979-12-01

    The conditions for an experiment to study the critical ionization velocity effect in the interaction between a Xenon cloud, released from a satellite, and the ionospheric plasma are investigated. The model used is based on the assumption that there exists an effective process that transfers the energy, that is available in the relative motion, to the electrons. Some necessary conditions to obtain significant heating or deceleration of the plasma penetrating the cloud are calculated. The conditions are mainly given by the energy available in the relative motion and the rates of the different binary collision processes involved. As the released gas cloud expands the possibilities for a critical velocity interaction will exist only within a certain range of cloud radii. It is shown that the charge transfer collision cross section between the ionospheric ions and the cloud atoms is an important parameter and that Xenon is a very suitable gas in that respect. (author)

  3. The effect of processing parameters on plasma sprayed beryllium for fusion applications

    International Nuclear Information System (INIS)

    Castro, R.G.; Stanek, P.W.; Jacobson, L.W.; Cowgill, D.F.

    1993-01-01

    Plasma spraying is being investigated as a potential coating technique for applying thin (0.1-5mm) layers of beryllium on plasma facing surfaces of blanket modules in ITER and also as an in-situ repair technique for repairing eroded beryllium surfaces in high heat flux divertor regions. High density spray deposits (>98% of theoretical density) of beryllium will be required in order to maximize the thermal conductivity of the beryllium coatings. A preliminary investigation was done to determine the effect of various processing parameters (particle size, particle morphology, secondary gas additions and reduced chamber pressure) on the as-deposited density of beryllium. The deposits were made using spherical beryllium feedstock powder which was produced by centrifugal atomization at Los Alamos National Laboratory (LANL). Improvements in the as-deposited densities and deposit efficiencies of the beryllium spray deposits will be discussed along with the corresponding thermal conductivity and outgassing behavior of these deposits. (orig.)

  4. Temporal evolution of the spectral lines emission and temperatures in laser induced plasmas through characteristic parameters

    International Nuclear Information System (INIS)

    Bredice, F.; Pacheco Martinez, P.; Sánchez-Aké, C.; Villagrán-Muniz, M.

    2015-01-01

    In this work, we propose an extended Boltzmann plot method to determine the usefulness of spectral lines for plasma parameter calculations. Based on the assumption that transient plasmas are under ideal conditions during an specific interval of time Δt, (i.e. thin, homogeneous and in local thermodynamic equilibrium (LTE)), the associated Boltzmann plots describe a surface in the space defined by the coordinates X = Energy, Y = Time and Z = ln (λ jl I j /g j A jl ), where I j is the integrated intensity of the spectral line, g j is the statistical weight of the level j, λ jl is the wavelength of the considered line and A jl is its transition rate. In order to express the Boltzmann plot surface in terms of a reduced set of constants B i , and δ i , we developed as a power series of time, the logarithm of I n (t)/I n (t 0 ), where I n (t) is the integrated intensity of any spectral line at time t, and I n (t 0 ) at initial time. Moreover, the temporal evolution of the intensity of any spectral line and consequently the temperature of the plasma can be also expressed with these constants. The comparison of the temporal evolution of the line intensity calculated using these constants with their experimental values, can be used as a criterion for selecting useful lines in plasma analysis. Furthermore, this method can also be applied to determine self-absorption or enhancement of the spectral lines, to evaluate a possible departure of LTE, and to check or estimate the upper level energy value of any spectral line. An advantage of this method is that the value of these constants does not depend on the spectral response of the detection system, the uncertainty of the transition rates belonging to the analyzed spectral lines or any other time-independent parameters. In order to prove our method, we determined the constants B i and δ i and therefore the Boltzmann plot surface from the temporal evolution of carbon lines obtained from a plasma generated by a Nd:YAG laser

  5. Temporal evolution of the spectral lines emission and temperatures in laser induced plasmas through characteristic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Bredice, F., E-mail: faustob@ciop.unlp.edu.ar [Centro de Investigaciones Ópticas, P.O. Box 3 C. P.1897 Gonnet, La Plata (Argentina); Pacheco Martinez, P. [Grupo de Espectroscopía Óptica de Emisión y Láser, Universidad del Atlántico, Barranquilla (Colombia); Sánchez-Aké, C.; Villagrán-Muniz, M. [Laboratorio de Fotofísica, Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Apartado Postal 70-186, México D.F. 04510 (Mexico)

    2015-05-01

    In this work, we propose an extended Boltzmann plot method to determine the usefulness of spectral lines for plasma parameter calculations. Based on the assumption that transient plasmas are under ideal conditions during an specific interval of time Δt, (i.e. thin, homogeneous and in local thermodynamic equilibrium (LTE)), the associated Boltzmann plots describe a surface in the space defined by the coordinates X = Energy, Y = Time and Z = ln (λ{sub jl}I{sub j}/g{sub j}A{sub jl}), where I{sub j} is the integrated intensity of the spectral line, g{sub j} is the statistical weight of the level j, λ{sub jl} is the wavelength of the considered line and A{sub jl} is its transition rate. In order to express the Boltzmann plot surface in terms of a reduced set of constants B{sub i}, and δ{sub i}, we developed as a power series of time, the logarithm of I{sub n}(t)/I{sub n}(t{sub 0}), where I{sub n}(t) is the integrated intensity of any spectral line at time t, and I{sub n}(t{sub 0}) at initial time. Moreover, the temporal evolution of the intensity of any spectral line and consequently the temperature of the plasma can be also expressed with these constants. The comparison of the temporal evolution of the line intensity calculated using these constants with their experimental values, can be used as a criterion for selecting useful lines in plasma analysis. Furthermore, this method can also be applied to determine self-absorption or enhancement of the spectral lines, to evaluate a possible departure of LTE, and to check or estimate the upper level energy value of any spectral line. An advantage of this method is that the value of these constants does not depend on the spectral response of the detection system, the uncertainty of the transition rates belonging to the analyzed spectral lines or any other time-independent parameters. In order to prove our method, we determined the constants B{sub i} and δ{sub i} and therefore the Boltzmann plot surface from the temporal

  6. The impact of BMI on sperm parameters and the metabolite changes of seminal plasma concomitantly.

    Science.gov (United States)

    Guo, Dan; Wu, Wei; Tang, Qiuqin; Qiao, Shanlei; Chen, Yiqiu; Chen, Minjian; Teng, Mengying; Lu, Chuncheng; Ding, Hongjuan; Xia, Yankai; Hu, Lingqing; Chen, Daozhen; Sha, Jiahao; Wang, Xinru

    2017-07-25

    The development of male infertility increased rapidly worldwide, which coinciding with the epidemic of obesity. However, the impact of weight abnormalities on sperm quality is still contestable. To assess the correlation between BMI and sperm parameters, we searched relevant articles in PubMed, Embase, Web of science, and Wanfang database published until June 2015 without language restriction. Otherwise, we also recruited some participants who attended fertility clinic as well as some general populations in this report. We performed a systematic review and meta-analysis about BMI and sperm parameters containing total sperm count, concentration, semen volume and sperm motility (overall and progressive). Metabolomic analysis of seminal plasma was performed to explore the mechanism from a new perspective. This study found standardized weighted mean differences (SMD) in sperm parameters (total sperm count, sperm concentration, and semen volume) of abnormal weight groups decreased to different degree compared to normal weight. Dose-response analysis found SMD of sperm count, sperm concentration and semen volume respectively fell 2.4%, 1.3% and 2.0% compared with normal weight for every 5-unit increase in BMI. Metabolomic analysis of seminal plasma showed that spermidine and spermine were likely to play a vital role in the spermatogenesis progress. This systematic review with meta-analysis has confirmed there was a relationship between BMI and sperm quality, suggesting obesity may be a detrimental factor of male infertility.

  7. Rocket measurements within a polar cap arc: Plasma, particle, and electric circuit parameters

    International Nuclear Information System (INIS)

    Weber, E.J.; Ballenthin, J.O.; Basu, S.; Carlson, H.C.; Hardy, D.A.; Maynard, N.C.; Smiddy, M.; Kelley, M.C.; Fleischman, J.R.; Sheehan, R.E.; Pfaff, R.F.; Rodriguez, P.

    1989-01-01

    An instrumented rocket payload was launched into a polar cap F layer aurora to investigate the energetic particle, plasma, and electric circuit parameters of a Sun-aligned arc. On-board instruments measured energetic electron flux, ion composition and density fluctuations, electron density and temperature, electron density fluctuations, and ac and dc electric fields. Real-time all-sky imaging photometer measurements of the location and motion of the aurora, were used to determine the proper geophysical situation for launch. Comparison of the in situ measurements with remote optical measurements shows that the arc was produced by fluxes of low-energy (< 1 keV) electrons. Field-aligned potentials in the arc inferred from the electron spectra had a maximum value of approximately 300 V, and from the spectral shape a parent population of preaccelerated electrons characteristic of the boundary plasma sheet or magnetosheath was inferred. Electric field components along and across the arc show sunward flow within the arc and duskward drift of the arc consistent with the drift direction and speed determined from optical imaging. Thus this arc is drifting duskward under the influence of the convection electric field. Three possible explanations for this (field-aligned currents, chemistry, and transport) are considered. Finally, ionospheric irregularity and electric field fluctuations indicate two different generation mechanisms on the dawnside and duskside of the arc. On the duskside, parameters are suggestive of an interchange process, while on the dawnside, fluctuation parameters are consistent with a velocity shear instability

  8. Penentuan Efektifitas Oksitetrasiklin Melalui Parameter Farmakokinetik/farmakodinamik pada Plasma dan Jaringan Ayam Broiler

    Directory of Open Access Journals (Sweden)

    Agustina Dwi Wijayanti

    2010-06-01

    Full Text Available A study was conducted to determine the effectiveness of oxytetracycline on the basis of itspharmacokinetic/pharmacodynamic (PK/PD parameters in the plasma and tissues of broiler following a50 mg/kg single dose of intravenous administration. The male broiler were injected with oxytetracycline attarsal medial venous. The blood, liver, kidney and abdominal muscle were collected at 14 points of timesamplings. Blood was centrifuged to obtain plasma and all tissues were extracted with Mc Ilvine buffer.Drug concentration in samples was determined by High Performance Liquid Chromatography (HPLCusing AOAC standard reference for tetracycline. The pharmacokinetic parameters of oxytetracycline werecalculated using non compartment method. The results were as follows. For plasma: the AUC was 790,615,5 ?g/mL minute , Clearance was 63,242 mL/min/kg bb, Tmax/Cmax was 1 minute/0,7 ?g/mL, T1/2elimination was 6,4, hours, Vd was 37 L/kg. For liver ; AUC was 36418,89, minute , Tmax/Cmax was 16hours/17,15 ?g/g, and T1/2 elimination was 24,5, hours. For kidney; AUC6808,41 ?g/g minute , Tmax/Cmax 1 minute/16,73 ?g/g, , T1/2 elimination was 11,55 hours. For muscle; AUC was 3502 ?g/g minute,Tmax/Cmax was 1 minute/2,58 ?g/g, T1/2 elimination was 167,39 hours. The ratio of AUC/MIC inplasma and tissues appeared to a good pharmacokinetic/pharmacodynamic parameter to determine theeffectiveness of oxytetracycline.

  9. On scattering diagnostics with periodically pulsed lasers to follow the continuous evolution of time dependent plasma parameters

    International Nuclear Information System (INIS)

    Hellermann, M. von; Hirsch, K.; Doeble, H.F.

    1977-04-01

    The possibilities to use periodically pulsed lasers for plasma scattering diagnostics are discussed. An experiment with succesful application of a periodically pulsed frequency-doubled Nd:YAG laser is described and results are given. Application of the method to monitor continuously, with millisecond time resolution, parameters of Tokamak type plasmas, is considered. (orig.) [de

  10. The producing of an ECR plasma using 2450MHz Whistler Wave and the investigating of its parameters

    International Nuclear Information System (INIS)

    Fang Yude; Zhang Jiande; Fu Keming; Lu Xiangyu; Liu Dengcheng; Wang Xianyu; Xie Weidong; Bao Dinghua; Yin Xiejin

    1988-12-01

    A stable ECR plasma was produced and sustained in HER mirror using 2450MHz Whistler wave. The parameters of the ECR plasma and their chaining characters were studied in detail and were compared with those of the DC discharge plasmas. The conclusion is that the ECR plasma is a high ionizability, low temperature, middle density plasma, its peak density may much exceed the cutoff density of the pump wave (when ω = ω pe ) and arrive at the order of 10 12 cm -3 . The ECR plasma includes some high energy hot electrons (20Kev-200Kev) and middle energy warm electrons (< 20Kev). Those two kinds of electron created some strong X-ray emissions in a wide frequency range. The ECR plasma has higher edge density and can strongly interact with the wall. (author). 9 refs, 17 figs

  11. Functionalization of Cellulose Fibres with Oxygen Plasma and ZnO Nanoparticles for Achieving UV Protective Properties

    Directory of Open Access Journals (Sweden)

    Katja Jazbec

    2015-01-01

    Full Text Available Low-pressure oxygen plasma created by an electrodeless radiofrequency (RF discharge was applied to modify the properties of cellulosic fibrous polymer (cotton in order to improve adsorption properties towards zinc oxide (ZnO nanoparticles and to achieve excellent ultraviolet (UV protective properties of cotton fabric. The chemical and physical surface modifications of plasma-treated cotton fabric were examined by X-ray photoelectron spectroscopy (XPS and scanning electron microscopy (SEM. The mechanical properties of plasma-treated samples were evaluated, measuring strength and elongation of the fabrics. The quantity of zinc on the ZnO-functionalized cotton samples was determined using inductively coupled plasma mass spectrometry (ICP-MS and the effectiveness of plasma treatment for UV protective properties of cotton fabrics was evaluated using UV-VIS spectrometry, measuring the UV protection factor (UPF. The results indicated that longer plasma treatment times cause higher concentration of oxygen functional groups on the surface of fibres and higher surface roughness of fibres. These two conditions are crucial in increasing the content of ZnO nanoparticles on the fibres, providing excellent UV protective properties of treated cotton, with UPF factor up to 65.93.

  12. Self-consistent static analysis of using nested-well plasma traps for achieving antihydrogen recombination

    International Nuclear Information System (INIS)

    Dolliver, D. D.; Ordonez, C. A.

    1999-01-01

    The use of a Malmberg-Penning type trap with nested electric potential wells to confine overlapping antiproton and positron plasmas for the purpose of producing low temperature antihydrogen is studied. Two approaches for confining antiproton and positron plasmas with a region of overlap are considered. In one approach the two components have a large temperature difference. In the other, one of the components is in a nonequilibrium 'antishielding' plasma state. A finite differences algorithm is used to solve Poisson's equation based on a simultaneous overrelaxation numerical approach. Self-consistent numerical results for required trap potentials and possible particle density profiles are presented

  13. Mercury-free electrodeless discharge lamp: effect of xenon pressure and plasma parameters on luminance

    International Nuclear Information System (INIS)

    Nazri Dagang Ahmad; Kondo, Akira; Motomura, Hideki; Jinno, Masafumi

    2009-01-01

    Since there is much concern about environmental preservation, the authors have paid attention to the uses of mercury in lighting application. They have focused on the application of the xenon low-pressure inductively coupled plasma (ICP) discharge in developing cylindrical type mercury-free light sources. ICP can be operated at low filling gas pressures and demonstrates significant potential in producing high density plasma. Xenon pressure was varied from 0.1 to 100 Torr and the lamp luminance was measured. The gas pressure dependence shows an increase in luminance at pressures below 1 Torr. In order to clarify this behaviour, measurement of plasma parameters was carried out using the double probe method and its relation to lamp luminance is discussed. As the gas pressure is decreased (from 1 to 0.01 Torr), the electron temperature increases while the electron density decreases while at the same time the lamp luminance increases. There are several factors that are believed to contribute to the increase in luminance in the very low pressure region. Increases in luminance are considered to be due to the electron-ion recombination process which brings a strong recombination radiation in continuum in the visible region and also due to the effect of stochastic heating.

  14. Optimal Machining Parameters for Achieving the Desired Surface Roughness in Turning of Steel

    Directory of Open Access Journals (Sweden)

    LB Abhang

    2012-06-01

    Full Text Available Due to the widespread use of highly automated machine tools in the metal cutting industry, manufacturing requires highly reliable models and methods for the prediction of output performance in the machining process. The prediction of optimal manufacturing conditions for good surface finish and dimensional accuracy plays a very important role in process planning. In the steel turning process the tool geometry and cutting conditions determine the time and cost of production which ultimately affect the quality of the final product. In the present work, experimental investigations have been conducted to determine the effect of the tool geometry (effective tool nose radius and metal cutting conditions (cutting speed, feed rate and depth of cut on surface finish during the turning of EN-31 steel. First and second order mathematical models are developed in terms of machining parameters by using the response surface methodology on the basis of the experimental results. The surface roughness prediction model has been optimized to obtain the surface roughness values by using LINGO solver programs. LINGO is a mathematical modeling language which is used in linear and nonlinear optimization to formulate large problems concisely, solve them, and analyze the solution in engineering sciences, operation research etc. The LINGO solver program is global optimization software. It gives minimum values of surface roughness and their respective optimal conditions.

  15. Lindhard's polarization parameter and atomic sum rules in the local plasma approximation

    DEFF Research Database (Denmark)

    Cabrera-Trujillo, R.; Apell, P.; Oddershede, J.

    2017-01-01

    In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom with nuc......In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom...... in terms of a screened charge Z* for the ground state. Our study shows that by increasing χ, the sum rule for p0 it increases, and the value p=0 provides the normalization/closure relation which remains fixed to the number of electrons for the same initial state. When p is fixed...

  16. Influence of the plasma pedestal parameters on ELM mitigation at low collisionality

    Energy Technology Data Exchange (ETDEWEB)

    Leuthold, Nils [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Universitaet Bayreuth, Universitaetsstrasse 30, 95440 Bayreuth (Germany); Suttrop, Wolfgang [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2016-07-01

    The control of Edge Localized Modes (ELMs) is of great importance for future fusion devices in order to provide longevity of the plasma facing components and a better overall plasma performance. In recent magnetic perturbation ELM mitigation experiments in ASDEX Upgrade at low pedestal collisionality, the dependence of ELM losses on pedestal parameters is investigated. It is found that the reduction of the stored energy loss associated with ELMs occurs in correlation with a reduction of edge density and edge pedestal pressure induced by the applied magnetic perturbation (''pedestal pump-out''). Significant ELM mitigation occurs at lowest densities, in a region of pedestal n-T parameter space that has not been accessible in ASDEX Upgrade without magnetic perturbations, and which is occupied by type-IV ELMs in DIII-D. The role of magnetic perturbations for ELM mitigation will be discussed in this context and attempts to counteract the confinement loss by increasing neutral beam injection power or pellet injection increases the ELM energy losses.

  17. Performance Testing of Suspension Plasma Sprayed Thermal Barrier Coatings Produced with Varied Suspension Parameters

    Directory of Open Access Journals (Sweden)

    Nicholas Curry

    2015-07-01

    Full Text Available Suspension plasma spraying has become an emerging technology for the production of thermal barrier coatings for the gas turbine industry. Presently, though commercial systems for coating production are available, coatings remain in the development stage. Suitable suspension parameters for coating production remain an outstanding question and the influence of suspension properties on the final coatings is not well known. For this study, a number of suspensions were produced with varied solid loadings, powder size distributions and solvents. Suspensions were sprayed onto superalloy substrates coated with high velocity air fuel (HVAF -sprayed bond coats. Plasma spray parameters were selected to generate columnar structures based on previous experiments and were maintained at constant to discover the influence of the suspension behavior on coating microstructures. Testing of the produced thermal barrier coating (TBC systems has included thermal cyclic fatigue testing and thermal conductivity analysis. Pore size distribution has been characterized by mercury infiltration porosimetry. Results show a strong influence of suspension viscosity and surface tension on the microstructure of the produced coatings.

  18. Dielectric parameters of blood plasma of rats treated with cerium-144 and external irradiation

    International Nuclear Information System (INIS)

    Hadzhidekova, E.; Kiradzhiev, G.; Paskalev, Z.; Miloslavov, V.

    1988-01-01

    Investigation was carried out of the dielectric parameters of blood plasma of male Wistar rats treated with cerium 144 in doses of 370 kBq/animal and external gamma irradiation in doses of 200 cGy and 400 cGy. The radioactive cerium was introduced intraperitoneally 1 h after the external irradiation with dose rate of 1,6 cGy/sec. The permittivity ε, the time of relaxation τ and the coefficient of Debaye κ of plasma protein molecules were determined at the 1st, 3rd, 10th, 15th, and 30th days after treatement for frequence ranges of 1,4, 2,2, 3,6 and 6 MHz. At the same terms the content of cerium 144 was measured in the organs of predilectional accumulation of cerium. It was established that the treatment only with cerium lead to most essential changes of dielectric parameters at frequence of 3,6 MHz. The external irradiation didn't influence essentially the kinetics of absorbed cerium. In combination of both radiation factors the action of cerium was predominant

  19. Visualizing the influence of the process parameters on the keyhole dimensions in plasma arc welding

    International Nuclear Information System (INIS)

    Liu, Z M; Wu, C S; Chen, M A

    2012-01-01

    The keyhole status and its dimensions are critical information determining both the process quality and weld quality in plasma arc welding (PAW). It is of great significance to measure the keyhole shape and size and to correlate them with the main process parameters. In this study, a low-cost vision system is developed to visualize the keyhole at the backside of the test-pieces in PAW. Three stages of keyhole evolution, i.e. initial blind stage (non-penetrated keyhole), unstable stage with momentarily disappeared keyhole and quasi-steady open keyhole stage (fully-penetrated keyhole), are measured in real-time during the PAW tests on stainless steel test-pieces of thickness 8 mm. Based on the captured images of keyhole under different welding conditions, the correlations of the main welding process parameters (welding current, welding speed, plasma gas flow rate) with the keyhole length, width and area are visualized through vision measurement. It lays a solid foundation for implementing keyhole stability control and process optimization in keyhole PAW. (paper)

  20. Relationship between Lipids Levels of Serum and Seminal Plasma and Semen Parameters in 631 Chinese Subfertile Men.

    Directory of Open Access Journals (Sweden)

    Jin-Chun Lu

    Full Text Available This prospective study was designed to investigate the relationship between lipids levels in both serum and seminal plasma and semen parameters.631 subfertile men were enrolled. Their obesity-associated markers were measured, and semen parameters were analyzed. Also, seminal plasma and serum TC, TG, HDL and LDL and serum FFA, FSH, LH, total testosterone (TT, estradiol (E2 and SHBG levels were detected.Seminal plasma and serum TG, TC and LDL levels were positively related to age. Serum TC, TG and LDL were positively related to obesity-associated markers (P < 0.001, while only seminal plasma TG was positively related to them (P < 0.05. For lipids levels in serum and seminal plasma, only TG level had slightly positive correlation between them (r = 0.081, P = 0.042. There was no significant correlation between serum lipids levels and semen parameters. However, seminal plasma TG, TC, LDL and HDL levels were negatively related to one or several semen parameters, including semen volume (SV, sperm concentration (SC, total sperm count (TSC, sperm motility, progressive motility (PR and total normal-progressively motile sperm counts (TNPMS. Moreover, seminal plasma TG, TC, LDL and HDL levels in patients with oligospermatism, asthenospermia and teratozoospermia were higher than those with normal sperm concentration, motility or morphology. After adjusting age and serum LH, FSH, TT, E2 and SHBG levels, linear regression analysis showed that SV was still significantly correlated with seminal plasma LDL (P = 0.012, both of SC and TSC with seminal plasma HDL (P = 0.028 and 0.002, and both of PR and sperm motility with seminal plasma TC (P = 0.012 and 0.051.The abnormal metabolism of lipids in male reproductive system may contribute to male factor infertility.

  1. A study of evolution/suppression parameters of equatorial postsunset plasma instability

    Directory of Open Access Journals (Sweden)

    O. S. Oyekola

    2009-01-01

    Full Text Available Evening equatorial pre-reversal vertical ion E×B drift (VZP and the peak of the ionospheric F2 maximum altitude (hmF2P of the postsunset equatorial F-layer, which are the essential parameters requisite for the generation or inhibition of postsunset bottomside equatorial irregularities were deduced from ionosonde observations made in the Africa region (Ouagadougou: ~3° N dip latitude between January 1987 and December 1990 for solar activity minimum, medium, and maxima (F10.7=85, 141, 214, and 190, respectively for quiet geomagnetic conditions. We investigate variations of evening equatorial pre-reversal drift and the corresponding altitude at four levels of solar activity. Our observations show strong variations with solar variability. Correlation analysis between these parameters indicates that the correlation coefficient value between hmF2P versus VZP decreases considerably with increasing solar flux value. There seems to be no significant link between these parameters under high solar activity, especially for solar intensity F10.7>200 units. We conclude that meridional neutral wind in the F-region contributes substantially to the variations of the pre-reversal vertical plasma drifts enhancement and the peak hmF2, particularly the electrodynamics during twilight high solar flux conditions.

  2. Determination of edge plasma parameters by a genetic algorithm analysis of spectral line shapes

    International Nuclear Information System (INIS)

    Marandet, Y.; Genesio, P.; Godbert-Mouret, L.; Koubiti, M.; Stamm, R.; Capes, H.; Guirlet, R.

    2003-01-01

    Comparing an experimental and a theoretical line shape can be achieved by a genetic algorithm (GA) based on an analogy to the mechanisms of natural selection. Such an algorithm is able to deal with complex non-linear models, and can avoid local minima. We have used this optimization tool in the context of edge plasma spectroscopy, for a determination of the temperatures and fractions of the various populations of neutral deuterium emitting the D α line in 2 configurations of Tore-Supra: ergodic divertor and toroidal pumped limiter. Using the GA fit, the neutral emitters are separated into up to 4 populations which can be identified as resulting from molecular dissociation reactions, charge exchange, or reflection. In all the edge plasmas studied, a significant fraction of neutrals emit in the line wings, leading to neutrals with a temperature up to a few hundreds eV if a Gaussian line shape is assumed. This conclusion could be modified if the line wing exhibits a non Gaussian behavior

  3. Determination of edge plasma parameters by a genetic algorithm analysis of spectral line shapes

    Energy Technology Data Exchange (ETDEWEB)

    Marandet, Y.; Genesio, P.; Godbert-Mouret, L.; Koubiti, M.; Stamm, R. [Universite de Provence (PIIM), Centre de Saint-Jerome, 13 - Marseille (France); Capes, H.; Guirlet, R. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2003-07-01

    Comparing an experimental and a theoretical line shape can be achieved by a genetic algorithm (GA) based on an analogy to the mechanisms of natural selection. Such an algorithm is able to deal with complex non-linear models, and can avoid local minima. We have used this optimization tool in the context of edge plasma spectroscopy, for a determination of the temperatures and fractions of the various populations of neutral deuterium emitting the D{sub {alpha}} line in 2 configurations of Tore-Supra: ergodic divertor and toroidal pumped limiter. Using the GA fit, the neutral emitters are separated into up to 4 populations which can be identified as resulting from molecular dissociation reactions, charge exchange, or reflection. In all the edge plasmas studied, a significant fraction of neutrals emit in the line wings, leading to neutrals with a temperature up to a few hundreds eV if a Gaussian line shape is assumed. This conclusion could be modified if the line wing exhibits a non Gaussian behavior.

  4. Study of thermal and electrical parameters of workpieces during spray coating by electrolytic plasma jet

    International Nuclear Information System (INIS)

    Khafizov, A A; Shakirov, Yu I; Valiev, R A; Valiev, R I; Khafizova, G M

    2016-01-01

    In this paper the results are presented of thermal and electrical parameters of products in the system bottom layer - intermediate layer when applying protective coatings of ferromagnetic powder by plasma spray produced in an electric discharge with a liquid cathode, on steel samples. Temperature distribution and gradients in coating and intermediate coating were examined. Detailed descriptions of spray coating with ferromagnetic powder by plasma jet obtained in electrical discharge with liquid cathode and the apparatus for obtaining thereof is provided. Problem has been solved by using of Fourier analysis. Initial data for calculations is provided. Results of numerical analysis are provided as temporal functions of temperature in contiguity between coating and intermediate coating as well as temporal function of the value Q=q-φ; where q is density of heat current directed to the free surface of intermediate coating, φ is density of heat current in contiguity between coating and intermediate coating. The analysis of data given shows that in the systems of contact heat exchange bottom layer-intermediate layer with close values of the thermophysical characteristics of constituting materials is observed a slow increase of the temperature of the contact as a function of time. (paper)

  5. Using sensitivity derivatives for design and parameter estimation in an atmospheric plasma discharge simulation

    International Nuclear Information System (INIS)

    Lange, Kyle J.; Anderson, W. Kyle

    2010-01-01

    The problem of applying sensitivity analysis to a one-dimensional atmospheric radio frequency plasma discharge simulation is considered. A fluid simulation is used to model an atmospheric pressure radio frequency helium discharge with a small nitrogen impurity. Sensitivity derivatives are computed for the peak electron density with respect to physical inputs to the simulation. These derivatives are verified using several different methods to compute sensitivity derivatives. It is then demonstrated how sensitivity derivatives can be used within a design cycle to change these physical inputs so as to increase the peak electron density. It is also shown how sensitivity analysis can be used in conjunction with experimental data to obtain better estimates for rate and transport parameters. Finally, it is described how sensitivity analysis could be used to compute an upper bound on the uncertainty for results from a simulation.

  6. GEOS-1 observations of electrostatic waves, and their relationship with plasma parameters

    International Nuclear Information System (INIS)

    Christiansen, P.J.; Gough, M.P.; Martelli, G.; Beghin, C.; Decreau, P.; Jones, D.

    1978-01-01

    In this paper the authors describe and discuss the occurrence of natural wave emissions detected by GEOS-1 at frequencies above the electron gyrofrequency. The bulk of the data presented comes from the first six months of satellite operation and thus concerns mainly dayside phenomena. A classification of the wave phenomena is developed, and experimental evidence and morphological information relevant to this classification are given. Some preliminary comments on nightside observations are included. The results are discussed, and it is argued that they can be understood as manifestations of electron cyclotron harmonic (Bernstein) wave emission in a plasma parameter range which has only very recently received any theoretical examinations. This theme is further developed in a companion paper (Roennmark et al., 1978). (Auth.)

  7. Effect of low density H-mode operation on edge and divertor plasma parameters

    International Nuclear Information System (INIS)

    Maingi, R.; Mioduszewski, P.K.; Cuthbertson, J.W.

    1994-07-01

    We present a study of the impact of H-mode operation at low density on divertor plasma parameters on the DIII-D tokamak. The line-average density in H-mode was scanned by variation of the particle exhaust rate, using the recently installed divertor cryo-condensation pump. The maximum decrease (50%) in line-average electron density was accompanied by a factor of 2 increase in the edge electron temperature, and 10% and 20% reductions in the measured core and divertor radiated power, respectively. The measured total power to the inboard divertor target increased by a factor of 3, with the major contribution coming from a factor of 5 increase in the peak heat flux very close to the inner strike point. The measured increase in power at the inboard divertor target was approximately equal to the measured decrease in core and divertor radiation

  8. Internal oscillating current-sustained RF plasmas: Parameters, stability, and potential for surface engineering

    DEFF Research Database (Denmark)

    Ostrikov, K.; Tsakadze, E.L.; Tsakadze, Z.L.

    2005-01-01

    . Moreover, under certain conditions, the plasma becomes unstable due to spontaneous transitions between low-density (electrostatic, E) and high-density (electromagnetic, H) operating modes. Excellent uniformity of high-density plasmas makes the plasma reactor promising for various plasma processing...... applications and surface engineering. (c) 2005 Elsevier B.V. All rights reserved....

  9. Jet quenching parameter in an expanding QCD plasma arXiv

    CERN Document Server

    Iancu, Edmond; Wu, Bin

    We study the phenomenon of transverse momentum broadening for a high-$p_T$ parton propagating through a weakly-coupled quark-gluon plasma undergoing boost-invariant longitudinal expansion. We propose a boost-invariant description for this phenomenon, in which the broadening refers to the angular variables $\\eta$ (the pseudo-rapidity) and $\\phi$ (the azimuthal angle). The jet quenching parameter $\\hat{q}$ which enters this description depends upon the proper time alone. We furthermore consider radiative corrections to $\\hat q$. As in the case of a static medium, we find potentially large corrections enhanced by a double logarithm. But unlike for the static medium, these corrections are now local in time: they depend upon the local (proper) time characterizing the expansion, and not upon the overall path length. We resum such corrections to all orders into a renormalized jet quenching parameter. The main effect of this resummation is to slow down the decrease of $\\hat q$ with increasing proper time.

  10. Dielectric parameters of blood plasma in rats at external and internal irradiation with sublethal doses

    International Nuclear Information System (INIS)

    Khadzhidekova, E.; Kiradzhiev, G.

    1991-01-01

    Sexually mature male rats have received external gamma irradiation with 50, 200 or 380 cGy, treated with 89 Sr (333 or 1665 kBq per rat, femur dose 70, resp. 290 cGy), or 144 Ce (370 kBq per rat, liver dose 70 cGy). Dielectric parameters (permittivity and conductivity) have been measured in the frequency range 1.4 - 17 Mhz on different terms (1 to 30th day after the treatment). For all groups and terms the coefficients and equations describing the relationship between the dielectric permittivity ε and the frequency ν of the changing electric field have been calculated. On the basis of dielectric parameters the relaxation time of the plasma protein molecules is determined. It has been shown that the changes in dielectric permittivity are expressed at different frequencies specific for a given dose; the same is established for the conditions of internal irradiation. The frequency dependence of the permittivity is described as an exponential curve analogous to that of the control but with a changed exponent. In applying higher doses or activities the relationship turns from exponential to parabolic. The relaxation time, expressing the changes in conformal state of macromolecules, varies but is in all cases longer than one of the controls for the whole period of study at external irradiation with 50 and 380 cGy. It is lower at irradiation with 200 cGy, as well as at internal irradiation. 3 tabs., 13 refs

  11. A study of evolution/suppression parameters of equatorial postsunset plasma instability

    Directory of Open Access Journals (Sweden)

    O. S. Oyekola

    2009-01-01

    Full Text Available Evening equatorial pre-reversal vertical ion E×B drift (VZP and the peak of the ionospheric F2 maximum altitude (hmF2P of the postsunset equatorial F-layer, which are the essential parameters requisite for the generation or inhibition of postsunset bottomside equatorial irregularities were deduced from ionosonde observations made in the Africa region (Ouagadougou: ~3° N dip latitude between January 1987 and December 1990 for solar activity minimum, medium, and maxima (F10.7=85, 141, 214, and 190, respectively for quiet geomagnetic conditions. We investigate variations of evening equatorial pre-reversal drift and the corresponding altitude at four levels of solar activity. Our observations show strong variations with solar variability. Correlation analysis between these parameters indicates that the correlation coefficient value between hmF2P versus VZP decreases considerably with increasing solar flux value. There seems to be no significant link between these parameters under high solar activity, especially for solar intensity F10.7>200 units. We conclude that meridional neutral wind in the F-region contributes substantially to the variations of the pre-reversal vertical plasma drifts enhancement and the peak hmF2, particularly the electrodynamics during twilight high solar flux conditions.

  12. Properties and parameters of the electron beam injected into the mirror magnetic trap of a plasma accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, V. V., E-mail: temple18@mail.ru; Novitsky, A. A.; Vinnichenko, L. A.; Umnov, A. M.; Ndong, D. O. [Peoples’ Friendship University of Russia (Russian Federation)

    2016-03-15

    The parameters of the injector of an axial plasma beam injected into a plasma accelerator operating on the basis of gyroresonance acceleration of electrons in the reverse magnetic field are determined. The trapping of the beam electrons into the regime of gyroresonance acceleration is numerically simulated by the particle- in-cell method. The optimal time of axial injection of the beam into a magnetic mirror trap is determined. The beam parameters satisfying the condition of efficient particle trapping into the gyromagnetic autoresonance regime are found.

  13. Reduction of MRI acoustic noise achieved by manipulation of scan parameters – A study using veterinary MR sequences

    International Nuclear Information System (INIS)

    Baker, Martin A.

    2013-01-01

    Sound pressure levels were measured within an MR scan room for a range of sequences employed in veterinary brain scanning, using a test phantom in an extremity coil. Variation of TR and TE, and use of a quieter gradient mode (‘whisper’ mode) were evaluated to determine their effect on sound pressure levels (SPLs). Use of a human head coil and a human brain sequence was also evaluated. Significant differences in SPL were achieved for T2, T1, T2* gradient echo and VIBE sequences by varying TR or TE, or by selecting the ‘whisper’ gradient mode. An appreciable reduction was achieved for the FLAIR sequence. Noise levels were not affected when a head coil was used in place of an extremity coil. Due to sequence parameters employed, veterinary patients and anaesthetists may be exposed to higher sound levels than those experienced in human MR examinations. The techniques described are particularly valuable in small animal MR scanning where ear protection is not routinely provided for the patient.

  14. Effect of basic physical parameters to control plasma meniscus and beam halo formation in negative ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, K. [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan); Okuda, S.; Nishioka, S.; Hatayama, A. [Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2013-09-14

    Our previous study shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources: the negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. In this article, the detail physics of the plasma meniscus and beam halo formation is investigated with two-dimensional particle-in-cell simulation. It is shown that the basic physical parameters such as the H{sup −} extraction voltage and the effective electron confinement time significantly affect the formation of the plasma meniscus and the resultant beam halo since the penetration of electric field for negative ion extraction depends on these physical parameters. Especially, the electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of electron diffusion across the magnetic field. The plasma meniscus penetrates deeply into the source plasma region when the effective electron confinement time is short. In this case, the curvature of the plasma meniscus becomes large, and consequently the fraction of the beam halo increases.

  15. Effect of basic physical parameters to control plasma meniscus and beam halo formation in negative ion sources

    International Nuclear Information System (INIS)

    Miyamoto, K.; Okuda, S.; Nishioka, S.; Hatayama, A.

    2013-01-01

    Our previous study shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources: the negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. In this article, the detail physics of the plasma meniscus and beam halo formation is investigated with two-dimensional particle-in-cell simulation. It is shown that the basic physical parameters such as the H − extraction voltage and the effective electron confinement time significantly affect the formation of the plasma meniscus and the resultant beam halo since the penetration of electric field for negative ion extraction depends on these physical parameters. Especially, the electron confinement time depends on the characteristic time of electron escape along the magnetic field as well as the characteristic time of electron diffusion across the magnetic field. The plasma meniscus penetrates deeply into the source plasma region when the effective electron confinement time is short. In this case, the curvature of the plasma meniscus becomes large, and consequently the fraction of the beam halo increases

  16. Collision Time Measurements in a Sonoluminescing Microplasma with a Large Plasma Parameter

    Science.gov (United States)

    Bataller, A.; Kappus, B.; Camara, C.; Putterman, S.

    2014-07-01

    The plasma which forms inside of a micron-sized sonoluminescing bubble in water for under a nanosecond has been probed with 3 ns long laser pulses. A comparison of the response to 532 and 1064 nm light indicates that the plasma number density is about 2×1021 cm-3 and that transport properties are dominated by strong screening and correlation effects. The spherical shape, well-defined atomic density, and blackbody temperature make the sonoluminescing plasma a test bed for theories of strongly coupled plasmas. The plasma in this experiment distinguishes between competing theories of strong, intermediate, and weak effective screening.

  17. Effect of dietary protein sources on production performance, egg quality, and plasma parameters of laying hens

    Directory of Open Access Journals (Sweden)

    Xiaocui Wang

    2017-03-01

    Full Text Available Objective This study was conducted to evaluate the effects of dietary protein sources (soybean meal, SBM; low-gossypol cottonseed meal, LCSM; double-zero rapeseed meal, DRM on laying performance, egg quality, and plasma parameters of laying hens. Methods A total of 432 32-wk-old laying hens were randomly divided into 6 treatments with 6 replicates of 12 birds each. The birds were fed diets containing SBM, LCSM100, or DRM100 individually or in combination with an equal amount of crude protein (CP (LCSM50, DRM50, and LCSM50-DRM50. The experimental diets, which were isocaloric (metabolizable energy, 11.11 MJ/kg and isonitrogenous (CP, 16.5%, had similar digestible amino acid profile. The feeding trial lasted 12 weeks. Results The daily egg mass was decreased in the LCSM100 and LCSM50-DRM50 groups (p0.05 and showed increased yolk color at the end of the trial (p0.05. Conclusion Together, our results suggest that the LCSM100 or DRM100 diets may produce the adverse effects on laying performance and egg quality after feeding for 8 more weeks. The 100.0 g/kg LCSM diet or the148.7 g/kg DRM diet has no adverse effects on laying performance and egg quality.

  18. Kinetic parameters for plasma β-endorphin in lean and obese Zucker rats

    International Nuclear Information System (INIS)

    Rodd, D.; Farrell, P.A.; Caston, A.L.; Green, M.H.

    1991-01-01

    To determine plasma clearance kinetics for β-endorphin (BE) by empirical compartmental analysis, a bolus of radioactive labeled 125I-BE was rapidly injected into a carotid artery catheter of unanesthetized lean (L) and obese (O) Zucker rats. The plasma disappearance of 125I was followed over a 3-h period. A 3-component exponential equation provided the best fit for plasma data. Plasma transit times were very short (10 s); however, plasma fractional catabolic rate was much slower. Plasma mean residence time was similar for both groups (50 min) as was recycle time (1.3 min). These data suggest that BE plasma disappearance kinetics are similar in L and O rats

  19. Kinetic parameters for plasma. beta. -endorphin in lean and obese Zucker rats

    Energy Technology Data Exchange (ETDEWEB)

    Rodd, D.; Farrell, P.A.; Caston, A.L.; Green, M.H. (Department of Exercise and Sport Science, Pennsylvania State University, University Park (USA))

    1991-03-01

    To determine plasma clearance kinetics for {beta}-endorphin (BE) by empirical compartmental analysis, a bolus of radioactive labeled 125I-BE was rapidly injected into a carotid artery catheter of unanesthetized lean (L) and obese (O) Zucker rats. The plasma disappearance of 125I was followed over a 3-h period. A 3-component exponential equation provided the best fit for plasma data. Plasma transit times were very short (10 s); however, plasma fractional catabolic rate was much slower. Plasma mean residence time was similar for both groups (50 min) as was recycle time (1.3 min). These data suggest that BE plasma disappearance kinetics are similar in L and O rats.

  20. Enhanced THz radiation generation by photo-mixing of tophat lasers in rippled density plasma with a planar magnetostatic wiggler and s-parameter

    Science.gov (United States)

    Abedi-Varaki, M.

    2018-02-01

    In this paper, the effects of planar magnetostatic wiggler and s-parameter on the terahertz (THz) radiation generation through rippled plasma have been investigated. Efficient THz radiation generation by photo-mixing of tophat lasers for rippled density plasma in the presence of the wiggler field has been presented. Fundamental equations for the analysis of the non-linear current density and THz radiation generation by wiggler magnetostatic field have been derived. It is shown that for the higher order of the tophat lasers, the values of THz amplitude are greater. In fact, the higher order of the tophat lasers has a sharp gradient in the intensity of lasers, which leads to a stronger nonlinear ponderomotive force and, consequently, a stronger current density. In addition, it is seen that by increasing s-parameter, the normalized transverse profile becomes more focused near the axis of y. Furthermore, it is observed that the normalized laser efficiency has a decreasing trend with increasing normalized THz frequency for different values of the wiggler field. Also, it is shown that by employing a greater order of the tophat lasers and a stronger wiggler field, the efficiency of order of 30% can be achieved. Moreover, it is found that we can control focus and intensity of THz radiation emitted in rippled plasma by choosing the appropriate order of the tophat lasers and tuning of the wiggler field.

  1. Development of plasma diagnostics technologies - Measurement of transport= parameters in tokamak edge plasma by using electric transport probes

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kyu Sun; Chang, Do Hee; Sim, Yeon Gun; Kim, Jin Hee [Hanyang University, Seoul (Korea, Republic of)

    1995-08-01

    Electric transport probe system is developed for the measurement of electron temperature, floating potential, plasma density and flow velocity of= edge plasmas in the KT-2 medium size tokamak. Experiments have been performed in KT-1 small size tokamak. Electric transport probe is composed of a single probe(SP) and a Mach probe (MP). SP is used for the measurements of electron density, floating potential, and plasma density and measured values are {approx} 3*10{sup 11}/cm{sup -3}, -20 volts, 15 {approx} 25 eV. For the most discharges, respectively. MP is for the measurements of toroidal(M{sub T}) and poloidal(M{sub P}) flow velocities, and density, which are M{sub T} {approx_equal} .0.85, M{sub P} {approx_equal}. 0.17, n. {approx_equal} 2.1*10{sup 11} cm{sup -3}, respectively. A triple probe is also developed for the direct reading of T{sub e} and n{sub e}, and is used for DC, RF, and RF+DC plasma in APL of Hanyang university. 38 refs., 36 figs. (author)

  2. Influence of laser design parameters on the hydrodynamics of microfusion plasmas; Influencia de los parametros basicos del laser sobre la hidrodinamica de plasmas para microfusion

    Energy Technology Data Exchange (ETDEWEB)

    Sanmartin, J A; Barrero, A

    1976-07-01

    The quasi neutral, one dimensional motion generated in a cold, infinite, uniform plasma of density n{sub 0}, by the absorption, In a given plane, of a linear pulse of energy per unit time and area {phi} - {phi}{sub 0}t/{tau}, 0< t {<=} {tau}, is considered; the analysis allows for thermal conduction and viscosity of ions and electrons, their energy exchange, and an electron thermal flux limiter. The motion is found to be self similar and governed by single non dimensional parameter {alpha} similar{sub t}o(n{sup 2}{sub 0} {tau}/{phi}{sub 0}){sup 2}/3. Detailed asymptotic results are obtained for both {alpha}<<1and {alpha}>>1; the general (behaviour of the solution for arbitrary {alpha} is discussed. The analysis can be easily extended to the case of a plasma initially occupying a half-space, and throws light on the hydrodynamics of laser fusion plasmas. (Author) 51 refs.

  3. Calculation of high-pressure argon plasma parameters produced by excimer laser

    International Nuclear Information System (INIS)

    Tsuda, Norio; Yamada, Jun

    2000-01-01

    When a XeCl excimer laser light was focused in a high-pressure argon gas up to 150 atm, a dense plasma developed not only backward but also forward. It is important to study on the electron density and temperature of the laser-induced plasma in the high-pressure gas. The electron density and temperature in high-pressure argon plasma produced by XeCl excimer laser has been calculated and compared with the experimental data. (author)

  4. Powder Particle Penetration into Steam-argon Plasma Jet and its Relation with Particle Parameters

    Czech Academy of Sciences Publication Activity Database

    Chumak, Oleksiy; Kopecký, Vladimír; Konrád, Miloš; Hrabovský, Milan; Kavka, Tetyana

    2004-01-01

    Roč. 54, suppl. C (2004), C931-C936 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21st/. Praha, 14.06.2004-17.06.2004] R&D Projects: GA AV ČR KSK2043105 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma sprazing, torch with hybrid stabilization, particle temperature Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

  5. Using numerical simulations to extract parameters of toroidal electron plasmas from experimental data

    DEFF Research Database (Denmark)

    Ha, B. N.; Stoneking,, M. R.; Marler, Joan

    2009-01-01

    Measurements of the image charge induced on electrodes provide the primary means of diagnosing plasmas in the Lawrence Non-neutral Torus II (LNT II) [Phys. Rev. Lett. 100, 155001 (2008)]. Therefore, it is necessary to develop techniques that determine characteristics of the electron plasma from......, as in the cylindrical case. In the toroidal case, additional information about the m=1 motion of the plasma can be obtained by analysis of the image charge signal amplitude and shape. Finally, results from the numerical simulations are compared to experimental data from the LNT II and plasma characteristics...

  6. Simulation of Main Plasma Parameters of a Cylindrical Asymmetric Capacitively Coupled Plasma Micro-Thruster using Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Amelia eGreig

    2015-01-01

    Full Text Available Computational fluid dynamics (CFD simulations of a radio-frequency (13.56 MHz electro-thermal capacitively coupled plasma (CCP micro-thruster have been performed using the commercial CFD-ACE+ package. Standard operating conditions of a 10 W, 1.5 Torr argon discharge were used to compare with previously obtained experimental results for validation. Results show that the driving force behind plasma production within the thruster is ion-induced secondary electrons ejected from the surface of the discharge tube, accelerated through the sheath to electron temperatures up to 33.5 eV. The secondary electron coefficient was varied to determine the effect on the discharge, with results showing that full breakdown of the discharge did not occur for coefficients coefficients less than or equal to 0.01.

  7. Design and construction the identification of nitriding plasma process parameters using personal computer based on serial communication

    International Nuclear Information System (INIS)

    Frida Iswinning Diah; Slamet Santosa

    2012-01-01

    Design and construction the identification of process parameters using personal computer based on serial communication PLC M-series has been done. The function of this device is to identify the process parameters of a system (plan), to which then be analyzed and conducted a follow-up given to the plan by the user. The main component of this device is the M-Series T100MD1616 PLC and personal computer (PC). In this device the data plan parameters obtained from the corresponding sensor outputs in the form of voltage or current. While the analog parameter data is adjusted to the ADC analog input of the PLC using a signal conditioning system. Then, as the parameter is processed by the PLC then sent to a PC via RS232 to be displayed in the form of graphs or tables and stored in the database. Software to program the database is created using Visual Basic Programming V-6. The device operation test is performed for the measurement of temperature parameter and vacuum level on the plasma nitriding machine. The results indicate that the device has functioning as an identification device parameters process of plasma nitriding machine. (author)

  8. The influence of pulse parameters on film composition during pulsed plasma polymerization of diaminocyclohexane

    Czech Academy of Sciences Publication Activity Database

    Choukourov, A.; Biederman, H.; Slavínská, D.; Trchová, Miroslava; Hollander, A.

    174-175, - (2003), s. 863-866 ISSN 0257-8972. [International Conference on Plasma Surface Engineering /8./. Garmisch-Partenkirchen, 09.09.2002-13.09.2002] R&D Projects: GA AV ČR KSK4050111 Keywords : plasma polymerization * chemical derivation * primary and secondary amino groups Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.410, year: 2003

  9. Evaluation of metabolism, plasma protein binding and other biological parameters after administration of (−)-[18 F]Flubatine in humans

    International Nuclear Information System (INIS)

    Patt, Marianne; Becker, Georg A.; Grossmann, Udo; Habermann, Bernd; Schildan, Andreas; Wilke, Stephan; Deuther-Conrad, Winnie; Graef, Susanne; Fischer, Steffen; Smits, René; Hoepping, Alexander; Wagenknecht, Gudrun; Steinbach, Jörg; Gertz, Hermann-Josef; Hesse, Swen; Schönknecht, Peter

    2014-01-01

    Introduction: (−)-[ 18 F]Flubatine is a PET tracer with high affinity and selectivity for the nicotinic acetylcholine α 4 β 2 receptor subtype. A clinical trial assessing the availability of this subtype of nAChRs was performed. From a total participant number of 21 Alzheimer’s disease (AD) patients and 20 healthy controls (HCs), the following parameters were determined: plasma protein binding, metabolism and activity distribution between plasma and whole blood. Methods: Plasma protein binding and fraction of unchanged parent compound were assessed by ultracentrifugation and HPLC, respectively. The distribution of radioactivity (parent compound + metabolites) between plasma and whole blood was determined ex vivo at different time-points after injection by gamma counting after separation of whole blood by centrifugation into the cellular and non-cellular components. In additional experiments in vitro, tracer distribution between these blood components was assessed for up to 90 min. Results: A fraction of 15% ± 2% of (−)-[ 18 F]Flubatine was found to be bound to plasma proteins. Metabolic degradation of (−)-[ 18 F]Flubatine was very low, resulting in almost 90% unchanged parent compound at 90 min p.i. with no significant difference between AD and HC. The radioactivity distribution between plasma and whole blood changed in vivo only slightly over time from 0.82 ± 0.03 at 3 min p.i. to 0.87 ± 0.03 at 270 min p.i. indicating the contribution of only a small amount of metabolites. In vitro studies revealed that (−)-[ 18 F]Flubatine was instantaneously distributed between cellular and non-cellular blood parts. Discussion: (−)-[ 18 F]Flubatine exhibits very favourable characteristics for a PET radiotracer such as slow metabolic degradation and moderate plasma protein binding. Equilibrium of radioactivity distribution between plasma and whole blood is reached instantaneously and remains almost constant over time allowing both convenient sample handling and

  10. Effect of plasma spraying parameter on wear resistance of NiCrBSiCFe plasma coatings on austenitic stainless steel at elevated temperatures at various loads

    International Nuclear Information System (INIS)

    Parthasarathi, N.L.; Duraiselvam, Muthukannan; Borah, Utpal

    2012-01-01

    Highlights: ► Effect of plasma spraying parameters, especially the stand-off distance. ► Effect of microstructure and applied load on coating in sliding wear. ► The reason for maximum wear rate at 250 °C and the minimum wear at 350 °C were explained. ► The worn debris were characterised by SEM analysis and correlated with wear rate. -- Abstract: The dry sliding wear tests were carried out on AISI 316 austenitic stainless steel (ASS) plasma coated with NiCrBSiCFe alloy powder under two set of plasma spraying parameters (PSP-1 and PSP-2). EN 8 medium carbon steel was used as a counterface material. The tests were carried out at loads of 20 N and 40 N with a constant sliding velocity of 1 m/s at room temperature (35°), 150 °C, 250 °C and 350 °C. Metallographic characterisation was carried out by optical microscope (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). Between the two plasma parameters tested, stand-off distance of 125 mm was found to be more suitable for producing uniform lamellar microstructure with fewer amounts of pores which shows better wear resistance. The wear rate at 250 °C was comparatively more due to the material softening and adhesion by intermolecular bonding. The worn debris collected during sliding at 350 °C turn into oxides which further behaves like a protective and lubricative film eliminating the chances of severe material loss. SEM was used to characterise the worn track and debris to identity the wear mechanism.

  11. V-I curves and plasma parameters in a high density DC glow discharge generated by a current-source

    International Nuclear Information System (INIS)

    Granda-Gutierrez, E E; Lopez-Callejas, R; Piedad-Beneitez, A de la; BenItez-Read, J S; Pacheco-Sotelo, J O; Pena-Eguiluz, R; A, R Valencia; Mercado-Cabrera, A; Barocio, S R

    2008-01-01

    Nitrogen DC glow discharges, conducted in a cylindrical geometry, have been characterized using a new current-source able to provide 10 -3 - 3 A for the sustainment of the discharge, instead of a conventional voltage-source. The V-I characteristic curves obtained from these discharges were found to fit the general form i(v) = A(p)v k(p) , whereby the plasma itself can be modeled as a voltage-controlled current-source. We conclude that the fitting parameters A and k, which mainly depend on the gas pressure p, are strongly related to the plasma characteristics, so much so that they can indicate the pressure interval in which the maximum plasma density is located, with values in the order of 10 16 m -3 at reduced discharge potential (300-600 V) and low working pressure (10 -1 - 10 1 Pa)

  12. Influence of laser design parameters on the hydrodynamics of microfusion plasmas

    International Nuclear Information System (INIS)

    Sanmartin, J. A.; Barrero, A.

    1976-01-01

    The quasi neutral, one dimensional motion generated in a cold, infinite, uniform plasma of density n 0 , by the absorption, In a given plane, of a linear pulse of energy per unit time and area φ - φ 0 t/τ, 0 t o(n 2 0 τ/φ 0 ) 2 /3. Detailed asymptotic results are obtained for both α >1; the general (behaviour of the solution for arbitrary α is discussed. The analysis can be easily extended to the case of a plasma initially occupying a half-space, and throws light on the hydrodynamics of laser fusion plasmas. (Author) 51 refs

  13. The effect of plasma fluctuations on parallel transport parameters in the SOL

    Czech Academy of Sciences Publication Activity Database

    Havlíčková, Eva; Fundameski, W.; Naulin, V.; Nielsen, A.H.; Wiesen, S.; Horáček, Jan; Seidl, Jakub

    2011-01-01

    Roč. 415, č. 1 (2011), S471-S474 ISSN 0022-3115. [International Conference on Plasma-Surface Interactions in Controlled Fusion Device/19th./. San Diego, 24.05.2010-28.05.2010] R&D Projects: GA ČR GAP205/10/2055; GA MŠk 7G09042 Institutional research plan: CEZ:AV0Z20430508 Keywords : Tokamak * plasma * transport Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.052, year: 2011 http://www.sciencedirect.com/science/article/pii/S002231151000560X

  14. Achieving concentrated graphene dispersions in water/acetone mixtures by the strategy of tailoring Hansen solubility parameters

    International Nuclear Information System (INIS)

    Yi Min; Shen Zhigang; Zhang Xiaojing; Ma Shulin

    2013-01-01

    Although exfoliating graphite to give graphene paves a new way for graphene preparation, a general strategy of low-boiling-point solvents and high graphene concentration is still highly required. In this study, using the strategy of tailoring Hansen solubility parameters (HSP), a method based on exfoliation of graphite in water/acetone mixtures is demonstrated to achieve concentrated graphene dispersions. It is found that in the scope of blending two mediocre solvents, tailoring the HSP of water/acetone mixtures to approach the HSP of graphene could yield graphene dispersions at a high concentration of up to 0.21 mg ml -1 . The experimentally determined optimum composition of the mixtures occurs at an acetone mass fraction of ∼75%. The trend of concentration varying with mixture compositions could be well predicated by the model, which relates the concentration to the mixing enthalpy within the scope of HSP theory. The resultant dispersion is highly stabilized. Atomic force microscopic statistical analysis shows that up to ∼50% of the prepared nanosheets are less than 1 nm thick after 4 h sonication and 114g centrifugation. Analyses based on diverse characterizations indicate the graphene sheets to be largely free of basal plane defects and oxidation. The filtered films are also investigated in terms of their electrical and optical properties to show reasonable conductivity and transparency. The strategy of tailoring HSP, which can be easily extended to various solvent systems, and water/acetone mixtures here, extends the scope for large-scale production of graphene in low-boiling-point solutions.

  15. Effectiveness of increasing the frequency of posaconazole syrup administration to achieve optimal plasma concentrations in patients with haematological malignancy.

    Science.gov (United States)

    Park, Wan Beom; Cho, Joo-Youn; Park, Sang-In; Kim, Eun Jung; Yoon, Seonghae; Yoon, Seo Hyun; Lee, Jeong-Ok; Koh, Youngil; Song, Kyoung-Ho; Choe, Pyoeng Gyun; Yu, Kyung-Sang; Kim, Eu Suk; Bang, Su Mi; Kim, Nam Joong; Kim, Inho; Oh, Myoung-Don; Kim, Hong Bin; Song, Sang Hoon

    2016-07-01

    Few data are available on whether adjusting the dose of posaconazole syrup is effective in patients receiving anti-cancer chemotherapy. The aim of this prospective study was to analyse the impact of increasing the frequency of posaconazole administration on optimal plasma concentrations in adult patients with haematological malignancy. A total of 133 adult patients receiving chemotherapy for acute myeloid leukaemia or myelodysplastic syndrome who received posaconazole syrup 200 mg three times daily for fungal prophylaxis were enrolled in this study. Drug trough levels were measured by liquid chromatography-tandem mass spectrometry. In 20.2% of patients (23/114) the steady-state concentration of posaconazole was suboptimal (increased to 200 mg four times daily. On Day 15, the median posaconazole concentration was significantly increased from 368 ng/mL [interquartile range (IQR), 247-403 ng/mL] to 548 ng/mL (IQR, 424-887 ng/mL) (P = 0.0003). The median increase in posaconazole concentration was 251 ng/mL (IQR, 93-517 ng/mL). Among the patients with initially suboptimal levels, 79% achieved the optimal level unless the steady-state level was increasing the administration frequency of posaconazole syrup is effective for achieving optimal levels in patients with haematological malignancy undergoing chemotherapy. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  16. Influence of laser design parameters on the hydrodynamics of microfusion plasmas

    International Nuclear Information System (INIS)

    Sanmartin, J.R.; Barrero, A.

    1976-01-01

    The quasineutral, oned ) 7mensional motion generated in a cold, infinite, uniform plasma of density n 0 , by the absorption, in a given plane, of a linear pulse of energy per unit time and area phi - phi 0 t/tau, 0 0 2 tau/phi 0 ) 2 /3. )etailed asymptotic results are obtained for both α > 1; the general behaviour of the solution for arbitrary α is discused. The analysis can be easily extended to the case of a plasma initially occuping a half-space, and throws light on the hydrodynamics of laser fusion plasmas. Approximate results existing in the literature for constant irradiation (phi) of a plasma are recovered under appropiate limiting processes. (author). )] [es

  17. Plasma parameters effects on the properties, aging and stability behaviors of allylamine plasma coated ultra-high molecular weight polyethylene (UHMWPE) films

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Gaelle, E-mail: gaelle.aziz@ugent.be; Thukkaram, Monica; De Geyter, Nathalie; Morent, Rino

    2017-07-01

    Highlights: • Medium to atmospheric pressure DBD is used to deposit amino rich films. • Process parameters affect the films’ surface chemical and physical properties. • High deposition rates can be reached by varying the power and/or monomer flow rate. • High amino selectivity (NH{sub 2}/N in %) is obtained at low powers and high monomer concentration. • Aging and stability behaviors of the deposited coatings can be controlled by carefully choosing the plasma parameters. - Abstract: In this work, a dielectric barrier discharge (DBD) operated at medium to atmospheric pressure has been used for the deposition of thin polyallylamine (PAA) films on ultra-high molecular weight polyethylene (UHMWPE) substrates. The effect of treatment time (1–5 min), discharge power (5.7–24.0 W), monomer concentration (1–2 g/h) and pressure (10–100 kPa) on the films properties, aging and stability behaviors have been investigated. The used characterization techniques are X-ray photoelectron spectroscopy, water contact angle and optical reflectance spectroscopy. In this paper, it is shown that plasma treatment time does not affect the coatings chemistry; whereas plasma power, monomer concentration and pressure control the coatings properties. It is also shown that the deposition rate of the deposited films changes with varying W/FM values. At low W/FM values, high deposition rates of up to 2 nm/s are observed. Plasma treatments were also characterized by their amino efficiency ([NH{sub 2}]/[C] in %) and amino selectivity ([NH{sub 2}]/[N] in %). Depending on the used parameters, these varied between 12.3% and 20% and between 71.2% and 91.1%, respectively. For the aging study, coatings that preserved most of their hydrophilicity were obtained at power ≤11.3 W, monomer concentration ≥1.5 g/h and pressure ≥50 kPa. For the stability study, coatings that showed the highest [N] (%) and lowest percentage of thickness decrease were obtained at ≤2 min, 24.0 W, 1 g/h and

  18. Streamer-induced emission and spectrometric determination of basic plasma parameters

    Czech Academy of Sciences Publication Activity Database

    Šimek, Milan

    2004-01-01

    Roč. 54, suppl.C (2004), C778-C783 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /21./. Praha, 14.06.2004-17.06.2004] R&D Projects: GA AV ČR IAA1043403 Institutional research plan: CEZ:AV0Z2043910 Keywords : optical diagnostics * discharge * streamer Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.292, year: 2004

  19. Effect of substrate and cathode parameters on the properties of suspension plasma sprayed solid oxide fuel cell electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Waldbillig, D.; Tang, Z.; Burgess, A. [British Columbia Univ., Vancouver, BC (Canada); Kesler, O. [Toronto Univ., ON (Canada)

    2008-07-01

    An axial injection suspension plasma spray system has been used to produce layers of fully stabilized yttriastabilized zirconia (YSZ) that could be used as solid oxide fuel cell (SOFC) electrolytes. Suspension plasma spraying is a promising technique for the rapid production of coatings with fine microstructures and controlled porosity without requiring a post-deposition heat treatment. This new manufacturing technique to produce SOFC active layers requires the build up of a number of different plasma sprayed SOFC functional layers (cathode, electrolyte and anode) sequentially on top of each other. To understand the influence of the substrate and previouslydeposited coating layers on subsequent coating layer properties, YSZ layers were deposited on top of plasma sprayed composite lanthanum strontium manganite (LSM)/YSZ cathode layers that were first deposited on porous ferritic stainless steel substrates. Three layer half cells consisting of the porous steel substrate, composite cathode, and suspension plasma sprayed electrolyte layer were then characterized. A systematic study was performed in order to investigate the effect of parameters such as substrate and cathode layer roughness, substrate surface pore size, and cathode microstructure and thickness on electrolyte deposition efficiency, cathode and electrolyte permeability, and layer microstructure. (orig.)

  20. Plasma parameters, fluctuations and kinetics in a magnetic field line reconnection experiment

    International Nuclear Information System (INIS)

    Wild, N.C. Jr.

    1983-01-01

    The processes associated with reconnecting magnetic field lines have been studied in a large experimental laboratory plasma. Detailed time- and space-resolved probe measurements of the plasma density, temperature, potential and electric and magnetic fields are discussed. Plasma currents are seen to modify the vacuum magnetic field topology. A flat neutral sheet develops along the separatrix where magnetic flux is transferred from regions of private to common flux. Forced tearing and magnetic island formation are also observed. Rapid electron heating, density and temperature nonuniformities and plasma potential gradients are all observed. The pressure is found to peak at the two edges of the neutral sheet. The dissipation E.J is determined and analyzed in terms of particle heating and fluid acceleration. A consistent, detailed picture of the energy flow via Poynting's theorem is also described. Significant temporal fluctuations in the magnetic fields and electron velocity distribution are measured and seen to give rise to anomalously high values for the plasma resistivity, the ion viscosity and the cross-field thermal conductivity. Electron temperature fluctuations, double layers associated with partial current disruptions, and whistler wave magnetic turbulence have all been identified and studied during the course of the reconnection event

  1. Dependence of polar effect on parameters of coaxial plasma-erosive switches

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Ivanov, I.B.; Krasik, Ya.E.; Ryzhakin, N.N.; Sinebryukhov, A.A.; Tolmacheva, V.G.

    1988-01-01

    The results of experimental investigations and numerical simulation of the polar effect in a coaxial plasma-erosive switch (PES) established in a circuit of a strong-current nanosecond accelerator are presented. PES characteristics (energy losses, impedance, rate of its increase, etc.) are investigated depending on mutual direction of accelerator current and plasma flow as well as on the cathode radius in the PES region. It is experimentally shown that the magnetic fields near the cathode determined by this electrode radius influences mainly on PES characteristics. Mutual direction of accelerator current and plasma flow is the second significance factor influencing on PES characteristics. The optimal mode of PES operation is realized when providing the less with respect to the positive electrode, cathode radius and coinciding in direction accelerator current and plasma flow. Numerical simulation of dynamic processes in coaxial PES for different ratios of cathode and anode radii and mutual directions of accelerator current and plasma flow gives qualitative agreement with the experimental results

  2. L-carnitine plasma levels in dogs and cats. A diagnostic parameter?

    International Nuclear Information System (INIS)

    Fischer, J.

    1993-04-01

    The relation between levels of carnitine in plasma and lesions of organs should be demonstrated. 52 dogs and 58 cats examined in veterinary clinics for several reasons and routinely screened for blood chemistry also were analysed for free plasma carnitine by a radiocarbon method. Increased carnitine levels were observed in both species in case of heart, liver and kidney disorders. Additionally the influence of food intake on carnitine levels in dogs was studied. Postprandial changes were insignificant. Because of lack of information about carnitine levels in cats and changes with age plasma carnitine was determined in cats and kittens. The range of normal values was 8.2 to 24.2 μmol/l without any significance of age

  3. Main error sources in sorbtion technique and plasma electron component parameter definition by continuous X radiation

    International Nuclear Information System (INIS)

    Gavrilov, V.V.; Torokhova, N.V.; Fasakhov, I.K.

    1986-01-01

    Recombination radiation effect on the relation of signals behind the filters depending on the plasma temperature(sorption method for T determination) is demonstrated. This factor produces the main effect on the method accuracy (100-400%), the other factors analysed in combination make an error in temperature at the level of 50%. Method of plasma electron distribution function reconstruction by continuous x-radiation spectrum, based on the correctness (under certain limitations for the required function) of the equation, linking the electron distribution function with bremmsstrahlung spectral density is presented

  4. Evolution of the plasma parameters in the expanding laser ablation plume of silver

    DEFF Research Database (Denmark)

    Christensen, Bo Toftmann; Schou, Jørgen; Hansen, T.N.

    2002-01-01

    The angular and radial variation of the ion density and electron temperature in the plasma plume produced by laser ablation of silver at fluences of 0.8-1.3 J cm(-2) at 355 nm have been studied using a time-resolving Langmuir probe. The angular dependence of the electron temperature...... and the magnitude of the ion flux, at the time when the ion flux is maximised, agree with the predictions of the self-similar isentropic model of the plasma expansion by Anisimov et al. (C) 2002 Elsevier Science B.V. All rights reserved....

  5. Measurement and interpretation of swarm parameters and their application in plasma modelling

    International Nuclear Information System (INIS)

    Petrovic, Z Lj; Dujko, S; Maric, D; Malovic, G; Nikitovic, Z; Sasic, O; Jovanovic, J; Stojanovic, V; Radmilovic-Radenovic, M

    2009-01-01

    In this review paper, we discuss the current status of the physics of charged particle swarms, mainly electrons, having plasma modelling in mind. The measurements of the swarm coefficients and the availability of the data are briefly discussed. We try to give a summary of the past ten years and cite the main reviews and databases, which store the majority of the earlier work. The need for reinitiating the swarm experiments and where and how those would be useful is pointed out. We also add some guidance on how to find information on ions and fast neutrals. Most space is devoted to interpretation of transport data, analysis of kinetic phenomena, and accuracy of calculation and proper use of transport data in plasma models. We have tried to show which aspects of kinetic theory developed for swarm physics and which segments of data would be important for further improvement of plasma models. Finally, several examples are given where actual models are mostly based on the physics of swarms and those include Townsend discharges, afterglows, breakdown and some atmospheric phenomena. Finally we stress that, while complex, some of the results from the kinetic theory of swarms and the related phenomenology must be used either to test the plasma models or even to bring in new physics or higher accuracy and reliability to the models. (review article)

  6. Surface temperature: A key parameter to control the propanethiol plasma polymer chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Thiry, Damien, E-mail: damien.thiry@umons.ac.be; Aparicio, Francisco J. [Chimie des Interactions Plasma Surface (ChIPS), CIRMAP, Université de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Laha, Priya; Terryn, Herman [Research Group Electrochemical and Surface Engineering (SURF), Department of Materials and Chemistry (MACH), Pleinlaan 2, 1050 Brussel (Belgium); Snyders, Rony [Chimie des Interactions Plasma Surface (ChIPS), CIRMAP, Université de Mons, 23 Place du Parc, B-7000 Mons, Belgium and Materia Nova Research Center, Parc Initialis, B-7000 Mons (Belgium)

    2014-09-01

    In this work, the influence of the substrate temperature (T{sub s}) on the chemical composition of propanethiol plasma polymers was investigated for a given set of plasma conditions. In a first study, a decrease in the atomic sulfur content (at. %S) with the deposition time (t{sub d}) was observed. This behavior is explained by the heating of the growing film during deposition process, limiting the incorporation of stable sulfur-based molecules produced in the plasma. Experiments carried out by controlling the substrate temperature support this hypothesis. On the other hand, an empirical law relating the T{sub s} and the at. %S was established. This allows for the formation of gradient layer presenting a heterogeneous chemical composition along the thickness, as determined by depth profile analysis combining X-ray photoelectron spectroscopy and C{sub 60} ion gun sputtering. The experimental data fit with the one predicted from our empiric description. The whole set of our results provide new insights in the relationship between the substrate temperature and the sulfur content in sulfur-based plasma polymers, essential for future developments.

  7. The effect of plasma fluctuations on parallel transport parameters in the SOL

    DEFF Research Database (Denmark)

    Havlíčková, E.; Fundamenski, W.; Naulin, Volker

    2011-01-01

    The effect of plasma fluctuations due to turbulence at the outboard midplane on parallel transport properties is investigated. Time-dependent fluctuating signals at different radial locations are used to study the effect of signal statistics. Further, a computational analysis of parallel transport...... to a comparison of steady-state and time-dependent modelling....

  8. Association of Irisin Plasma Levels with Anthropometric Parameters in Children with Underweight, Normal Weight, Overweight, and Obesity

    Directory of Open Access Journals (Sweden)

    Leticia Elizondo-Montemayor

    2017-01-01

    Full Text Available The correlations between irisin levels, physical activity, and anthropometric measurements have been extensively described in adults with considerable controversy, but little evidence about these relationships has been found in children. The objective of this study is to correlate the plasma levels of irisin in underweight, normal weight, overweight, and obese children with anthropometric parameters and physical activity levels. A cross-sample of 40 children was divided into the following groups on the basis of body mass index (BMI percentile. The correlations of plasma irisin levels with physical activity, anthropometric, and metabolic measurements were determined. Plasma irisin levels (ng/mL were lower for the underweight group (164.2 ± 5.95 than for the normal weight and obese groups (182.8 ± 5.58; p<0.05. Irisin levels correlated positively with BMI percentile (0.387, waist circumference (0.373, and fat-free mass (0.353; p<0.05, but not with body muscle mass (−0.027. After a multiple linear regression analysis, only BMI percentile (0.564; p<0.008 showed a positive correlation with irisin. Our results indicated no association with metabolic parameters. A negative correlation with physical activity was observed. Interrelationships among body components might influence irisin levels in children.

  9. Influence of the low-frequency source parameters on the plasma characteristics in a dual frequency capacitively coupled plasma reactor: Two dimensional simulations

    Institute of Scientific and Technical Information of China (English)

    Xiang Xu; Hao Ge; Shuai Wang; Zhongling Dai; Younian Wang; Aimin Zhu

    2009-01-01

    A two-dimensional (2D) fluid model is presented to study the discharge of argon in a dual frequency capacitively coupled plasma (CCP) reactor. We are interested in the influence of low-frequency (LF) source parameters such as applied voltage amplitudes and low frequencies on the plasma characteristics. In this paper, the high frequency is set to 60 MHz with voltage 50 V. The simulations were carried out for low frequencies of 1, 2 and 6 MHz with LF voltage 100 V, and for LF voltages of 60, 90 and 120 V with low frequency 2 MHz. The results of 2D distributions of electric field and ion density, the ion flux impinging on the substrate and the ion energy on the powered electrode are shown. As the low frequency increases, two sources become from uncoupling to coupling, When two sources are uncoupling, the increase in LF has little impact on the plasma characteristics, but when two sources are coupling, the increase in LF decreases the uniformities of ion density and ion flux noticeably. It is also found that with the increase in LF voltage, the uniformities in the radial direction of ion density distribution and ion flux at the powered electrode decreases significantly, and the energy of ions bombarding on the powered electrode increases significantly.

  10. Lupin seeds lower plasma lipid concentrations and normalize antioxidant parameters in rats

    Directory of Open Access Journals (Sweden)

    Osman, M.

    2011-06-01

    Full Text Available This study was designed to test bitter and sweet lupin seeds for lipid-lowering and for their antioxidative activities in hypercholesterolemic rats. The levels of plasma lipid, malondialdehyde (MDA and whole blood reduced glutathione (GSH, as well as the activities of transaminases (ALT and AST, lactate dehydrogenase (LDH in plasma, superoxide dismutase (SOD, glutathione peroxidase (GPx in erythrocytes and plasma glutathione reductase (GR, glutathione-S-transferase (GST and catalase (CAT were examined. A hypercholesterolemia-induced diet manifested in the elevation of total lipids (TL, total cholesterol (TC, triglycerides (TG, LDL-C and MDA levels, ALT, AST, LDH activities and the depletion of GSH and enzymic antioxidants. The supplementation of a hypercholesterolemia-induced diet with bitter and sweet lupin seeds significantly lowered the plasma levels of TL, TC, TG and LDL-C. ALT, AST and LDH activities slightly decreased in treated groups compared with the hypercholesterolemic group (HC. Furthermore, the content of GSH significantly increased while MDA significantly decreased in treated groups compared with the HC group. In addition, the bitter lupin seed group improved enzymic antioxidants compared with the HC group. In general, the results indicated that the bitter lupin seed supplements are better than those containing sweet lupin seeds. These results suggested that the hypocholesterolemic effect of bitter and sweet lupin seed supplements might be due to their abilities to lower the plasma cholesterol level as well as to slow down the lipid peroxidation process and to enhance the antioxidant enzyme activity.

    Este estudio fue diseñado para evaluar semillas de altramuces dulces y amargas como agentes que bajan los lípidos y estudiar su efecto en la actividad antioxidante en ratas hipercolesterolémicas. El nivel de lípidos en plasma, malondialdehido (MDA y glutatión reducido (GSH, así como la actividad transaminasa (ALT y AST

  11. Investigation of parameters of the working substance - low temperature plasma in the ionization resonator chamber of the RF reactive engine

    International Nuclear Information System (INIS)

    Vdovin, V.S.; Zajtzev, B.V.; Kobetz, A.F.; Bomko, V.A.; Rashkovan, V.M.; Bazyma, L.A.; Belokon, V.I.

    2003-01-01

    This paper is the extension of investigations of the RF engine designed for orientation and stabilization of the spacecrafts orbit, and it is undertaken for measuring of plasma parameters of RF discharge in the ionization resonator chamber. The experiments were performed at the frequency of 80 MHz on the model engine, in which a length of coaxial line with shortening capacities at the ends was used as the ionization resonator chamber. As the result of the experiments, conditions of the RF discharge ignition in the resonator chamber are studied; dependencies of plasma density and temperature versus applied power and working body pressure are obtained for various gases. The measurements of the thrust were performed at the special-purpose test bench

  12. Influence of alpha-particles on parameters of plasma confined in open traps

    International Nuclear Information System (INIS)

    Chebotaev, P.Z.

    1987-01-01

    The numerical calculations of the longitudinal motion in multi-mirror reactor have shown that the energy contribution of α-particles has substantial influence on the gain factor (the given off thermonuclear energy/ the initial imparted energy) in the temperature region 5-7 keV. The numerical technique has been developed that takes into account the radial distribution of alpha particles caused by their drag on electrons. This effect is substantial for ρ α /R ≥ 1/2 (where ρ α is alpha particles gyro radius, R is plasma radius), e.g. for Gas-Dinamic trap. In a Tandem-Mirror reactor some part of fusion alpha particles have the probability to slow down to the plasma energy, that can lead to the 'poisoning' of the reactor by the thermonuclear reaction products. The fusion alpha particles can have a strong effect on accumulation of impurities with z ≤ 15 and thermal alpha particles in TMR. (orig.)

  13. Plasma parameters in the channel of a long leader in air

    International Nuclear Information System (INIS)

    Aleksandrov, N.L.; Konchakov, A. M.; Bazelyan, E.M.

    2001-01-01

    The time evolution of the electric field in the leader channel and other characteristics of the leader plasma in long air gaps are simulated. Calculations are performed in the one-dimensional time-dependent model with allowance for the time-varying energy deposition in the channel, the channel expansion, and the nonequilibrium ionization kinetics in the leader plasma. The calculations show that, at a gas temperature of 4500-6000 K, associative ionization becomes a dominant ionization mechanism in the leader channel; as a result, the electric field decreases to 100-200 V/cm in 10 -4 -10 -3 s under the conditions typical of the leader discharge. The calculated electric field agrees well with the data from the experimental modeling of long leaders by a spark discharge in short gaps

  14. Recent angina pectoris: plasma lipoprotein atherogenic parameters and coronary angiographic data

    International Nuclear Information System (INIS)

    Kuznetsova, G.V.; Shcherbakova, I.A.; Gratsianskij, N.A.; Perova, N.V.; Nikitina, N.A.; Nechaev, A.S.; Ozerova, I.N.; Zholus, N.N.

    1986-01-01

    Coronary angiography and the assessment of blood lipoproteins were carried out in 43 patients with recent (not more than three months old) angina. A rise in cholesterol above 270 mg/dl and/or triglycerids bove 200 mg/dl was demonstrated in 19. The level of α-cholesterol was below 35 mg/dl in 11 of 24 normolipidemic patients. The apoprotein B/apoprotein AI ratio was above 1.0 in 7 of 13 patients with normal cholesterol levels. Plasma phospholipid composition was disturbed in 4 of 6 patients with normal apoprotein B/apoprotein AI rations. Therefore atherogenic changes in plasma lipoprotein composition were found in 95% of patients with recent angina

  15. Plasma parameters and electromagnetic forces induced by the magneto hydro dynamic interaction in a hypersonic argon flow experiment

    International Nuclear Information System (INIS)

    Cristofolini, Andrea; Neretti, Gabriele; Borghi, Carlo A.

    2012-01-01

    This work proposes an experimental analysis on the magneto hydro dynamic (MHD) interaction induced by a magnetic test body immersed into a hypersonic argon flow. The characteristic plasma parameters are measured. They are related to the voltages arising in the Hall direction and to the variation of the fluid dynamic properties induced by the interaction. The tests have been performed in a hypersonic wind tunnel at Mach 6 and Mach 15. The plasma parameters are measured in the stagnation region in front of the nozzle of the wind tunnel and in the free stream region at the nozzle exit. The test body has a conical shape with the cone axis in the gas flow direction and the cone vertex against the flow. It is placed at the nozzle exit and is equipped with three permanent magnets. In the configuration adopted, the Faraday current flows in a closed loop completely immersed into the plasma of the shock layer. The electric field and the pressure variation due to MHD interaction have been measured on the test body walls. Microwave adsorption measurements have been used for the determination of the electron number density and the electron collision frequency. Continuum recombination radiation and line radiation emissions have been detected. The electron temperature has been determined by means of the spectroscopic data by using different methods. The electron number density has been also determined by means of the Stark broadening of H α and the H β lines. Optical imaging has been utilized to visualize the pattern of the electric current distribution in the shock layer around the test body. The experiments show a considerable effect of the electromagnetic forces produced by the MHD interaction acting on the plasma flow around the test body. A comparison of the experimental data with simulation results shows a good agreement.

  16. Investigation of the time evolution of plasma parameters in a pulsed magnetron discharge

    Czech Academy of Sciences Publication Activity Database

    Straňák, V.; Hubička, Zdeněk; Adámek, P.; Blažek, J.; Tichý, M.; Špatenka, P.; Hippler, R.; Wrehde, S.

    2006-01-01

    Roč. 56, - (2006), s. 1364-1370 ISSN 0011-4626 R&D Projects: GA ČR GA202/05/2242; GA ČR GA202/06/0776 Grant - others:Deutsche Forschungsgemeinschaft(DE) SFB/TR 24 Institutional research plan: CEZ:AV0Z10100522 Keywords : pulsed magnetron * time resolved measurements * Langmuir probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

  17. Parameters of the plasma of a dc pulsating discharge in a supersonic air flow

    Energy Technology Data Exchange (ETDEWEB)

    Shibkov, V. M., E-mail: shibkov@phys.msu.ru; Shibkova, L. V.; Logunov, A. A. [Moscow State University, Faculty of Physics (Russian Federation)

    2017-03-15

    A dc discharge in a cold (T = 200 K) supersonic air flow at a static pressure of 200–400 Torr was studied experimentally. The excited unsteady pulsating discharge has the form of a thin plasma channel with a diameter of ≤1 mm, stretched downstream the flow. Depending on the discharge current, the pulsation frequency varies from 800 to 1600 Hz and the electron temperature varies from 8000 to 15000 K.

  18. Monitoring of plasma butyrylcholinesterase activity and hematological parameters in pesticide sprayers

    OpenAIRE

    Rastogi, S. K.; Singh, Vipul K.; Kesavachandran, C.; Jyoti,; Siddiqui, M. K. J.; Mathur, N.; Bharti, R. S.

    2008-01-01

    To evaluate the health impact of spraying organophosphorus insecticides (OPs), 34 male sprayers in the mango belt of Malihabad, a small town located 27 km from Lucknow in North India was selected. Plasma butyryl cholinesterase (PBChE) and complete blood count were assessed among sprayers after spraying pesticides and the findings obtained were compared with those determined in a reference group ( n = 18). The most common symptoms observed were burning sensation in the eyes (8.82%), it...

  19. Plasma analysis of different TiN PVD processes at various process parameters

    International Nuclear Information System (INIS)

    Strauss, G.N.; Schlichtherle, S.; Pulker, H.K.; Meyer, M.; Jehn, H.; Balzer, M.; Misiano, C.; Silipo, V.

    2002-01-01

    TiN coatings of some microns in thickness were deposited by different reactive plasma deposition technologies (Magnetron Sputtering Magnetically Assisted, Arc Source Ion Plating, Sputter Ion Plating Plasma Assisted) on various metal parts. The experiments were carried out in specially designed plants under variable vacuum and plasma conditions. The plasma properties of the different processes were investigated by mass spectrometry and the energy distribution of process relevant particles was additionally determined. The aim of this work was to find proper processes and conditions for a reliable low cost deposition of hard coatings at relatively high gas pressures. It was found that the magnetically forced and medium frequency pulsed biased dc magnetron sputter deposition variants, operating in the 10 -3 mbar gas pressure range, showed a relatively large amount of single and double charged positive ions with kinetic energies up to 55 and 95 eV, as consequence of the applied modifications. Cathodic arc deposition, in the same gas pressure range of 10 - 3 mbar, showed a very high number of such ions with energies up to more than 100 eV, depending on the value of the applied arc current. However, at constant distance between source and substrate the higher gas pressure increases also the number of energy reducing collisions of the coating-material vapour-species with the gas molecules. The arc source process, even when performed at high gas pressures of about 10 -1 mbar, showed a remarkable amount of ions with energies up to 75 eV resulting in high performance TiN films of quite proper 3D homogeneity. The arc source technique is able to increase film thickness uniformity up to 3 times with respect to the traditional coatings if the samples are mounted in a way that they do not influence each other. (nevyjel)

  20. Magnetosheath plasma stability and ULF wave occurrence as a function of location in the magnetosheath and upstream bow shock parameters

    Science.gov (United States)

    Soucek, Jan; Escoubet, C. Philippe; Grison, Benjamin

    2015-04-01

    We present the results of a statistical study of the distribution of mirror and Alfvén-ion cyclotron (AIC) waves in the magnetosheath together with plasma parameters important for the stability of ULF waves, specifically ion temperature anisotropy and ion beta. Magnetosheath crossings registered by Cluster spacecraft over the course of 2 years served as a basis for the statistics. For each observation we used bow shock, magnetopause, and magnetosheath flow models to identify the relative position of the spacecraft with respect to magnetosheath boundaries and local properties of the upstream shock crossing. A strong dependence of both plasma parameters and mirror/AIC wave occurrence on upstream ΘBn and MA is identified. We analyzed a joint dependence of the same parameters on ΘBn and fractional distance between shock and magnetopause, zenith angle, and length of the flow line. Finally, the occurrence of mirror and AIC modes was compared against the respective instability thresholds. We noted that AIC waves occurred nearly exclusively under mirror stable conditions. This is interpreted in terms of different characters of nonlinear saturation of the two modes.

  1. Determination of Stark parameters by cross-calibration in a multi-element laser-induced plasma

    Science.gov (United States)

    Liu, Hao; Truscott, Benjamin S.; Ashfold, Michael N. R.

    2016-05-01

    We illustrate a Stark broadening analysis of the electron density Ne and temperature Te in a laser-induced plasma (LIP), using a model free of assumptions regarding local thermodynamic equilibrium (LTE). The method relies on Stark parameters determined also without assuming LTE, which are often unknown and unavailable in the literature. Here, we demonstrate that the necessary values can be obtained in situ by cross-calibration between the spectral lines of different charge states, and even different elements, given determinations of Ne and Te based on appropriate parameters for at least one observed transition. This approach enables essentially free choice between species on which to base the analysis, extending the range over which these properties can be measured and giving improved access to low-density plasmas out of LTE. Because of the availability of suitable tabulated values for several charge states of both Si and C, the example of a SiC LIP is taken to illustrate the consistency and accuracy of the procedure. The cross-calibrated Stark parameters are at least as reliable as values obtained by other means, offering a straightforward route to extending the literature in this area.

  2. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources

    International Nuclear Information System (INIS)

    Christ-Koch, Sina

    2007-01-01

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields (∝ 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H - )=1.10 17 1/m 3 , which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  3. Effects of magnesium on erythrocyte sodium-lithium countertransport and some of plasma biochemical parameters in rabbit

    Directory of Open Access Journals (Sweden)

    Samad Akbarzadeh

    2009-02-01

    Full Text Available Background: Magnesium acts as an essential cofactor for the activity of many enzymes. It regulates the work of cardiovascular system. The activity of sodium–lithium countertransport (SLC and the concentrations of plasma biochemical parameters such as VLDL, LDL-cholesterol, HDL-cholesterol, sodium, potassium, urea and creatinine are changed in cardiovascular diseases. The aim of this study was to determine the effects of magnesium on SLC activity and some of the plasma biochemical parameters. Methods: New Zealand white rabbits (weighed 1350 ± 50g were chosen for these experiments. This study was conducted through two in vitro and in vivo techniques. Through in vitro method, the effects of different concentrations of magnesium on SLC activity were investigated. In order to conduct in vivo method, the rabbits were divided into two groups (5 /group. One group was treated by MgSo4 (40 mg/kg body weight through peritoneum for two weeks. For the second group, deionized water was used. The activity of SLC and mentioned biochemical parameters were determined. Results: The results of both in vitro and in vivo studies showed that magnesium can significantly decrease the SLC activity and also causes an increase in Km and decreased Vmax/Km of the system and plasma concentrations of VLDL, LDL-cholesterol, total cholesterol and triglycerides were significantly decreased. Conclusion: Magnesium may cause a reduction in blood pressure through decreasing the SLC activity and affecting the concentrations of VLDL, LDL-cholesterol, total cholesterol and triglycerides and so improvement the cardiovascular diseases.

  4. Plasma parameters in the vicinity of the quartz window of a low pressure surface wave discharge produced in O2

    DEFF Research Database (Denmark)

    Nakao, S.; Stamate, Eugen; Sugai, H.

    2007-01-01

    Plasma parameters in the vicinity of the dielectric window of a low density, microwave discharge produced in 0, at 915 N/FHz are investigated by a spherical probe and optical emission spectroscopy while the microwave field distribution is measured by a spectrum analyzer. The electron energy...... distribution function is found to be strongly dependent on the position with respect to the slot antenna, exhibiting a group of energetic electrons at locations where the electric field and the optical intensity exhibit maximum values. The density of energetic electrons decreases sharply just a few cm away...

  5. Determination of reference ranges for full blood count parameters in neonatal cord plasma in Hilla, Babil, Iraq

    Directory of Open Access Journals (Sweden)

    Al-Marzoki JM

    2012-10-01

    Full Text Available Jasim M Al-Marzoki1, Zainab W Al-Maaroof2, Ali H Kadhum31Department of Pediatrics, 2Department of Pathology, Babylon Medical College, 3Babylon Gynecology and Pediatric Teaching Hospital, Hilla, IraqBackground: The health of an individual is known to vary in different countries, in the same country at different times, and in the same individuals at different ages. This means that the condition of individuals must be related to or compared with reference data. Determination of a reference range for the healthy term newborn is clinically important in terms of various complete blood count parameters. The purpose of this study was to establish a local reference range for full blood count parameters in neonatal cord plasma in Hilla, Babil, Iraq.Methods: A total of 220 mothers and their neonates were enrolled in this cross-sectional study from February 2011 to January 2012. Maternal inclusion criteria were age 15–45 years, an uneventful pregnancy, and hemoglobin ≥ 10 g. Neonatal inclusion criteria were full term (37–42 weeks and normal birth weight. The umbilical cord was immediately clamped after delivery of the baby; 3 mL of cord blood was then taken from the umbilical vein and collected in a tube containing ethylenediamine tetra-acetic acid, its plasma was analyzed for full blood count parameters by standard Coulter gram, and the differential leukocyte count was done manually.Results: Mean neonatal hemoglobin was 13.88 ± 1.34 (range 11–17.3 g/dL and mean white cell count was 10.12 ± 2.8 (range 3.1–21.6 × 109/L. Mean platelet count was 267.63 ± 60.62 (range 152–472 × 109/L. No significant differences in red cell, white cell, or platelet counts were found between males and females, except for neutrophil count. The current study shows lower levels of hemoglobin, white cells, and red cells compared with other studies, and there is agreement with some studies and disagreement with others concerning platelet count.Conclusion: Most results

  6. Correlation between the physical parameters of the i-nc-Si absorber layer grown by 27.12 MHz plasma with the nc-Si solar cell parameters

    Science.gov (United States)

    Das, Debajyoti; Mondal, Praloy

    2017-09-01

    Growth of highly conducting nanocrystalline silicon (nc-Si) thin films of optimum crystalline volume fraction, involving dominant crystallographic preferred orientation with simultaneous low fraction of microstructures at a low substrate temperature and high growth rate, is a challenging task for its promising utilization in nc-Si solar cells. Utilizing enhanced electron density and superior ion flux densities of the high frequency (∼27.12 MHz) SiH4 plasma, improved nc-Si films have been produced by simple optimization of H2-dilution, controlling the ion damage and enhancing supply of atomic-hydrogen onto the growing surface. Single junction nc-Si p-i-n solar cells have been prepared with i-nc-Si absorber layer and optimized. The physical parameters of the absorber layer have been systematically correlated to variations of the solar cell parameters. The preferred alignment of crystallites, its contribution to the low recombination losses for conduction of charge carriers along the vertical direction, its spectroscopic correlation with the dominant growth of ultra-nanocrystalline silicon (unc-Si) component and corresponding longer wavelength absorption, especially in the neighborhood of i/n-interface region recognize scientific and technological key issues that pave the ground for imminent advancement of multi-junction silicon solar cells.

  7. Getting Ready for BepiColombo: A Modeling Approach to Infer the Solar Wind Plasma Parameters Upstream of Mercury from Magnetic Field Observations

    Science.gov (United States)

    Fatemi, S.; Poirier, N.; Holmström, M.; Wieser, M.; Barabash, S.

    2018-05-01

    We have developed a model to infer the solar wind plasma parameters upstream of Mercury from magnetic field observations in Mercury's magnetosphere. This is important for observations by MESSENGER and the future mission to Mercury, BepiColombo.

  8. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Spectroscopic investigation of thermodynamic parameters of a plasma plume formed by the action of cw CO2 laser radiation on a metal substrate

    Science.gov (United States)

    Vasil'chenko, Zh V.; Azharonok, V. V.; Filatova, I. I.; Shimanovich, V. D.; Golubev, V. S.; Zabelin, A. M.

    1996-09-01

    Emission spectroscopy methods were used in an investigation of thermodynamic parameters of a surface plasma formed by the action of cw CO2 laser radiation of (2-5)×106 W cm-2 intensity on stainless steel in a protective He or Ar atmosphere. The spatiotemporal structure and pulsation characteristics of the plasma plume were used to determine the fields of the plasma electron density and temperature.

  9. Optical characteristics and parameters of the plasma of a barrier discharge excited in a mixture of mercury dibromide vapor with nitrogen and helium

    Science.gov (United States)

    Malinina, A. A.; Guivan, N. N.; Shimon, L. L.; Shuaibov, A. K.

    2010-09-01

    Results are presented from experimental and theoretical studies of the optical characteristics and parameters of the plasma of an atmospheric-pressure barrier discharge excited in a HgBr2: N2: He mixture, which was used as the working medium of a small-size (with a radiation area of 8 cm2) exciplex gas-discharge radiation source. The mean radiation power of 87 mW was achieved at the radiation wavelength λmax = 502 nm. The electron energy distribution function, the transport characteristics, the specific energy lost in the processes involving electrons, the electron temperature and density, and the rate constants of elastic and inelastic electron scattering by the components of the working mixture were calculated as functions of the reduced field E/ N. The plasma of a discharge excited in a HgBr2: N2: He mixture can be used as the working medium of a small-size blue-green radiation source. Such a source can find application in biotechnology, photonics, and medicine and can also be used to manufacture gas-discharge display panels.

  10. Optimization of laser parameters to obtain high-energy, high-quality electron beams through laser-plasma acceleration

    International Nuclear Information System (INIS)

    Samant, Sushil Arun; Sarkar, Deepangkar; Krishnagopal, Srinivas; Upadhyay, Ajay K.; Jha, Pallavi

    2010-01-01

    The propagation of an intense (a 0 =3), short-pulse (L∼λ p ) laser through a homogeneous plasma has been investigated. Using two-dimensional simulations for a 0 =3, the pulse-length and spot-size at three different plasma densities were optimized in order to get a better quality beam in laser wakefield accelerator. The study reveals that with increasing pulse-length the acceleration increases, but after a certain pulse-length (L>0.23λ p ) the emittance blows-up unacceptably. For spot-sizes less than that given by k p0 r s =2√(a 0 ), trapping is poor or nonexistent, and the optimal spot-size is larger. The deviation of the optimal spot-size from this formula increases as the density decreases. The efficacy of these two-dimensional simulations has been validated by running three-dimensional simulations at the highest density. It has been shown that good quality GeV-class beams can be obtained at plasma densities of ∼10 18 cm -3 . The quality of the beam can be substantially improved by selecting only the high-energy peak; in this fashion an energy-spread of better than 1% and a current in tens of kA can be achieved, which are important for applications such as free-electron lasers.

  11. The effect of plasma arc process parameters on the properties of dissimilar AISI 1040/AISI 304 steel plate welds

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Musa; Kirik, Ihsan; Orhan, Nuri [Firat Univ., Elazig (Turkey); Celik, Ferkan [Science Industry and Technology Ministry of Turkey (Turkey)

    2012-11-01

    In this study, 10 mm thick AISI 1040 and AISI 304 steel plates were welded in the butt position without pretreatment by plasma transferred arc (PTA) welding technique. Therefore, mechanical behaviour, microstructure, penetration depth and length were investigated. After welding, microstructural changes in the interface regions of the welded specimens were examined by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Micro-hardness as well as V-notch Charpy tests were performed to determine the mechanical properties of the welds. The influence of the welding parameters on the dimension and shape of the joints has been found out. From the results, it was derived that with the parameters used, a partly keyhole weld bead formed with a penetration depth of 10 mm and a width of 11 mm in butt position. (orig.)

  12. Optimization of plasma parameters for the production of silicon nano-crystals

    CERN Document Server

    Chaabane, N; Vach, H; Cabarrocas, P R I

    2003-01-01

    We use silane-hydrogen plasmas to synthesize silicon nano-crystals in the gas phase and thermophoresis to collect them onto a cooled substrate. To distinguish between nano-crystals formed in the plasma and those grown on the substrate, as a result of surface and subsurface reactions, we have simultaneously deposited films on a conventional substrate heated at 250 deg. C and on a second substrate cooled down to 90 deg. C. A series of samples deposited at various discharge pressures, in the range of 400 mTorr to 1.2 Torr, have been characterized by Raman spectroscopy and ellipsometry. At low pressure (400-500 mTorr), the films are amorphous on the cold substrate and micro-crystalline on the hot one. As pressure increases, gas phase reactions lead to the formation of nano-crystalline particles which are attracted by the cold substrate due to thermophoresis. Consequently, we obtain nano-crystalline silicon thin films on the cold substrate and amorphous thin films on the heated one in the pressure range of 600-900...

  13. Monitoring of plasma butyrylcholinesterase activity and hematological parameters in pesticide sprayers.

    Science.gov (United States)

    Rastogi, S K; Singh, Vipul K; Kesavachandran, C; Jyoti; Siddiqui, M K J; Mathur, N; Bharti, R S

    2008-04-01

    To evaluate the health impact of spraying organophosphorus insecticides (OPs), 34 male sprayers in the mango belt of Malihabad, a small town located 27 km from Lucknow in North India was selected. Plasma butyryl cholinesterase (PBChE) and complete blood count were assessed among sprayers after spraying pesticides and the findings obtained were compared with those determined in a reference group (n = 18). The most common symptoms observed were burning sensation in the eyes (8.82%), itching/skin irritation (23.52%) and chest symptoms (32.35%) in the exposed workers. Plasma butyrylcholinesterase (PBChE) was significantly decreased in workers. The results indicated significant decrease in the mean value of hemoglobin, hematocrit and platelets count; however, significantly higher count of leukocytes was also observed in the exposed group (sprayers) compared to that observed in the control group (P < 0.05). Monitoring of PBChE in pesticide sprayers could be useful to predict and prevent health hazards of OPs.

  14. Edge transport barrier modification in the L-2M stellarator depending on the heating power and plasma parameters

    International Nuclear Information System (INIS)

    Voronov, G S; Voronova, E V; Akulina, D K; Gladkov, G A

    2006-01-01

    Boronization of the vacuum chamber of the L-2M stellarator has resulted in modification of the electron temperature profile. In particular, a well-defined jump in the electron temperature to T e ∼ 100 eV in a narrow region Δr/r ∼ 0.05 is observed in the temperature profile at the plasma edge. In the present paper, the value and shape of the jump in T e are studied at different values of plasma parameters and ECR heating power. A jump in T e is absent at a power of P ∼ 100 kW, whereas at P ∼ 200 kW the electron temperature drops from 150 eV to zero within Δr ∼ 0.5 cm. The value of threshold power for the formation of a jump in T e at n e ∼ 1.7 x 10 19 m -3 lies within the range P ∼ 100-160 kW. In terms of power per particle this power threshold is P/V/N e ∼ 0.2-0.3 Mw/m 3 /10 19 m -3 , the value of which coincides with threshold power for ETB formation found recently in the CHS stellarator. When the helical-field strength is 25% or 50% below its standard value, a jump in T e at the plasma edge in L-2M is absent

  15. Numerical simulation of dual frequency etching reactors: Influence of the external process parameters on the plasma characteristics

    International Nuclear Information System (INIS)

    Georgieva, V.; Bogaerts, A.

    2005-01-01

    A one-dimensional particle-in-cell/Monte Carlo model is used to investigate Ar/CF 4 /N 2 discharges sustained in capacitively coupled dual frequency reactors, with special emphasis on the influence of the reactor parameters such as applied voltage amplitudes and frequencies of the two voltage sources. The presented calculation results include plasma density, ion current, average sheath potential and width, electron and ion average energies and energy distributions, and ionization rates. The simulations were carried out for high frequencies (HFs) of 27, 40, 60, and 100 MHz and a low frequency (LF) of 1 or 2 MHz, varying the LF voltage and keeping the HF voltage constant and vice versa. It is observed that the decoupling of the two sources is possible by increasing the applied HF to very high values (above 60 MHz) and it is not defined by the frequency ratio. Both voltage sources have influence on the plasma characteristics at a HF of 27 MHz and to some extent at 40 MHz. At HFs of 60 and 100 MHz, the plasma density and ion flux are determined only by the HF voltage source. The ion energy increases and the ion energy distribution function (IEDF) becomes broader with HF or LF voltage amplitude, when the other voltage is kept constant. The IEDF is broader with the increase of HF or the decrease of LF

  16. Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

    Directory of Open Access Journals (Sweden)

    Johanna M Walz

    Full Text Available Vascular endothelial growth factor-A (VEGF-A is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements.Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD, cannula (butterfly vs. neonatal, type of centrifuge (swing-out vs. fixed-angle, time before and after centrifugation, filling level (completely filled vs. half-filled tubes and analyzing method (ELISA vs. multiplex bead array. Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model.The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes.VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

  17. Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders.

    Science.gov (United States)

    Walz, Johanna M; Boehringer, Daniel; Deissler, Heidrun L; Faerber, Lothar; Goepfert, Jens C; Heiduschka, Peter; Kleeberger, Susannah M; Klettner, Alexa; Krohne, Tim U; Schneiderhan-Marra, Nicole; Ziemssen, Focke; Stahl, Andreas

    2016-01-01

    Vascular endothelial growth factor-A (VEGF-A) is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements. Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center) twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD), cannula (butterfly vs. neonatal), type of centrifuge (swing-out vs. fixed-angle), time before and after centrifugation, filling level (completely filled vs. half-filled tubes) and analyzing method (ELISA vs. multiplex bead array). Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model. The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes. VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

  18. Investigation of plasma parameters at BATMAN for variation of the Cs evaporation asymmetry and comparing two driver geometries

    Science.gov (United States)

    Wimmer, C.; Fantz, U.; Aza, E.; Jovović, J.; Kraus, W.; Mimo, A.; Schiesko, L.

    2017-08-01

    The Neutral Beam Injection (NBI) system for fusion devices like ITER and, beyond ITER, DEMO requires large scale sources for negative hydrogen ions. BATMAN (Bavarian Test Machine for Negative ions) is a test facility attached with the prototype source for the ITER NBI (1/8 source size of the ITER source), dedicated to physical investigations due to its flexible access for diagnostics and exchange of source components. The required amount of negative ions is produced by surface conversion of hydrogen atoms or ions on caesiated surfaces. Several diagnostic tools (Optical Emission Spectroscopy, Cavity Ring-Down Spectroscopy for H-, Langmuir probes, Tunable Diode Laser Absorption Spectroscopy for Cs) allow the determination of plasma parameters in the ion source. Plasma parameters for two modifications of the standard prototype source have been investigated: Firstly, a second Cs oven has been installed in the bottom part of the back plate in addition to the regularly used oven in the top part of the back plate. Evaporation from the top oven only can lead to a vertically asymmetric Cs distribution in front of the plasma grid. Using both ovens, a symmetric Cs distribution can be reached - however, in most cases no significant change of the extracted ion current has been determined for varying Cs symmetry if the source is well-conditioned. Secondly, BATMAN has been equipped with a much larger, racetrack-shaped RF driver (area of 32×58 cm2) instead of the cylindrical RF driver (diameter of 24.5 cm). The main idea is that one racetrack driver could substitute two cylindrical drivers in larger sources with increased reliability and power efficiency. For the same applied RF power, the electron density is lower in the racetrack driver due to its five times higher volume. The fraction of hydrogen atoms to molecules, however, is at a similar level or even slightly higher, which is a promising result for application in larger sources.

  19. Effect of transient scrotal hyperthermia on sperm parameters, seminal plasma biochemical markers, and oxidative stress in men

    Directory of Open Access Journals (Sweden)

    Meng Rao

    2015-01-01

    Full Text Available In this experimental prospective study, we aimed to analyze the effect of transient scrotal hyperthermia on the male reproductive organs, from the perspective of sperm parameters, semen plasma biochemical markers, and oxidative stress, to evaluate whether different frequencies of heat exposure cause different degrees of damage to spermatogenesis. Two groups of volunteers (10 per group received testicular warming in a 43°C water bath 10 times, for 30 min each time: group 1: 10 consecutive days; group 2: once every 3 days. Sperm parameters, epididymis and accessory sex gland function, semen plasma oxidative stress and serum sex hormones were tested before treatment and in the 16-week recovery period after treatment. At last, we found an obvious reversible decrease in sperm concentration (P = 0.005 for Group 1 and P= 0.008 for Group 2 when the minimums were compared with baseline levels, the same below, motility (P = 0.009 and 0.021, respectively, the hypoosmotic swelling test score (P = 0.007 and 0.008, respectively, total acrosin activity (P = 0.018 and 0.009, respectively, and an increase in the seminal plasma malondialdehyde concentration (P = 0.005 and 0.017, respectively. The decrease of sperm concentration was greater for Group 2 than for Group 1 (P = 0.031. We concluded that transient scrotal hyperthermia seriously, but reversibly, negatively affected the spermatogenesis, oxidative stress may be involved in this process. In addition, intermittent heat exposure more seriously suppresses the spermatogenesis compared to consecutive heat exposure. This may be indicative for clinical infertility etiology analysis and the design of contraceptive methods based on heat stress.

  20. Time-space distribution of laser-induced plasma parameters and its influence on emission spectra of the laser plumes

    International Nuclear Information System (INIS)

    Ershov-Pavlov, E.A.; Katsalap, K.Yu.; Stepanov, K.L.; Stankevich, Yu.A.

    2008-01-01

    A physical model is developed accounting for dynamics and radiation of plasma plumes induced by nanosecond laser pulses on surface of solid samples. The model has been applied to simulate emission spectra of the laser erosion plasma at the elemental analysis of metals using single- and double-pulse excitation modes. Dynamics of the sample heating and expansion of the erosion products are accounted for by the thermal conductivity and gas dynamic equations, respectively, supposing axial symmetry. Using the resulting time-space distributions of the plasma parameters, emission spectra of the laser plumes are evaluated by solving the radiation transfer equation. Particle concentration in consecutive ionization stages is described by the Saha equation in the Debye approximation. The population of excited levels is determined according to Boltzmann distribution. Local characteristics determining spectral emission and absorption coefficients are obtained point-by-point along an observation line. Voigt spectral line profiles are considered with main broadening mechanisms taken into account. The plasma dynamics and plume emission spectra have been studied experimentally and by the model. A Q-switched Nd:YAG laser at 1064 nm wavelength has been used to irradiate Al sample with the pulses of 15 ns and 50 mJ duration and energy, respectively. It has resulted in maximum power density of 0.8 MW/cm 2 on the sample surface. The laser plume emission spectra have been recorded at a side-on observation. Problems of the spectra contrast and of the elemental analysis efficiency are considered relying on a comparative study of the measurement and simulation results at the both excitation modes

  1. Effect of the resonant magnetic perturbation on the plasma parameters in COMPASS tokamak’s divertor region

    Science.gov (United States)

    Dimitrova, M.; Cahyna, P.; Peterka, M.; Hasan, E.; Popov, Tsv K.; Ivanova, P.; Vasileva, E.; Panek, R.; Cavalier, J.; Seidl, J.; Markovic, T.; Havlicek, J.; Dejarnac, R.; Weinzettl, V.; Hacek, P.; Tomes, M.; the COMPASS Team; the EUROfusion MST1 Team

    2018-02-01

    The resonant magnetic perturbation (RMP) has proven to be a useful way to suppress edge-localized modes that under certain conditions can damage the device by the large power fluxes carried from the bulk plasma to the wall. The effect of RMP on the L-mode plasma parameters in the divertor region of the COMPASS tokamak was studied using the array of 39 Langmuir probes embedded into the divertor target. The current-voltage (IV) probe characteristics were processed by the first-derivative probe technique to obtain the plasma potential and the electron energy distribution function (EEDF) which was approximated by a bi-Maxwellian EEDF with a low-energy (4-6 eV) fraction and a high-energy (11-35 eV) one, the both factions having similar electron density. Clear splitting was observed during the RMP pulse in the low-field-side scrape-off-layer profiles of the floating potential U fl and the ion saturation current density J sat; these two quantities were obtained both by direct continuous measurement and by evaluation of the IV characteristics of probes with swept bias. The negative peaks of U fl induced by RMP spatially overlaps with the local minima of J sat (and n e) rather than with its local maxima which is partly caused by the spatial variation of the plasma potential and partly by the changed shape of the EEDF. The effective temperature of the whole EEDF is not correlated with the negative peaks of U fl, and the profile of the parallel power flux density shows secondary maxima due to RMP which mimic those of J sat.

  2. Parameter Dependence of Inward Diffusion on Injected Electrons in Helical Non-Neutral Plasmas

    International Nuclear Information System (INIS)

    Wakabayashi, H.; Himura, H.; Fukao, M.; Yoshida, Z.

    2003-01-01

    Experimental studies on an electron injection into a helical magnetic field and characteristics of non-neutral plasmas have been performed. It is found that the space potential φs has a weak dependence on the injection angle except for a narrow 'window' region in which φs significantly drops. A calculation shows that because of the electric field Eg of the electron gun (e-gun), the emitted electrons are launched quasi-parallel to the helical magnetic field B, regardless of α. This seems to agree with the observation. The 'window' seen in the data may be attributed to an current-driven instability which might result in the insufficient electron penetration or the degradation of electron confinement in the magnetic surface

  3. [Study on plasma parameters in diffuse discharge with semispherical electrod by optical emission spectrum].

    Science.gov (United States)

    Dong, Li-Fang; Tong, Guo-Liang; Shen, Zhong-Kai; Liu, Liang; Ji, Ya-Fei; Zhao, Huan-Huan

    2012-06-01

    The diffuse discharge plasma in air was observed in a dielectric barrier discharge with two semispherical water electrodes. The variations of vibration temperature, rotation temperature, and average electron energy as the function of the applied voltage were studied by emission spectroscopy. The vibration temperature and the rotation temperature were calculated through the second positive band system (C3Pi(u)-->B3Pi(g)) of N2+ and the first negative band system (B2 Sigma(u+)-->Chi2Sigma(g+)) of N(2+) respectively. The average electron energy was studied by intensity ratio of 391.4 and 337.1 nm. It was found that the rotation temperature increases with the applied voltage increasing, while the vibration temperature and the electron energy decrease.

  4. [Measurement of plasma parameters in slot microplasma by optical emission spectrum].

    Science.gov (United States)

    Dong, Li-Fang; Lü, Ying-Hui; Liu, Wei-Yuan; Yue, Han; Lu, Ning; Li, Xin-Chun

    2010-12-01

    Slot microplasma was generated in argon and air mixture by using dielectric barrier discharge device with two parallel water electrodes. The molecular vibrational temperature, molecular rotational temperature and average electron energy of the slot plasma were studied by optical emission spectrum. The molecular vibrational temperature was calculated using the second positive system of nitrogen molecules ( C3 pi(u) --> B3 pi(g)). The molecular rotational temperature was calculated using the first negative system of nitrogen molecular ions ( B 2sigma(u)+ --> X sigma(g)+). The relative intensities of the first negative system of nitrogen molecular ions (391.4 nm) and nitrogen molecules in the excitation level (337.1 nm) emission spectrum line were measured for studying the variations of electron energy. It was found that the molecular vibrational temperature, molecular rotational temperature and average electron energy decrease with gas pressure increasing.

  5. Optimization of the parameters of plasma liners with zero-dimensional models

    Energy Technology Data Exchange (ETDEWEB)

    Oreshkin, V. I. [Siberian Division, Institute of High Current Electronics, RAS Tomsk Polytechnic University, Tomsk 634055 (Russian Federation)

    2013-11-15

    The efficiency of conversion of the energy stored in the capacitor bank of a high-current pulse generator into the kinetic energy of an imploding plasma liner is analyzed. The analysis is performed by using a model consisting of LC circuit equations and equations of motion of a cylindrical shell. It is shown that efficient energy conversion can be attained only with a low-inductance generator. The mode of an 'ideal' load is considered where the load current at the final stage of implosion is close to zero. The advantages of this mode are, first, high efficiency of energy conversion (80%) and, second, improved stability of the shell implosion. In addition, for inertial confinement fusion realized by the scheme of a Z pinch dynamic hohlraum, not one but several fusion targets can be placed in the cavity on the pinch axis due to the large length of the liner.

  6. Electron density as the main parameter influencing the formation of fullerenes in a carbon plasma

    International Nuclear Information System (INIS)

    Churilov, G.N.; Bulina, N.V.; Novikov, P.V.; Lopatin, V.A.; Vnukova, N.G.; Bachilo, S.M.; Tsyboulski, D.; Weisman, R.B.

    2002-01-01

    Thermodynamic estimates are presented for the formation of spheroidal and flat carbon clusters from reactant species of different charges. Charge is shown to strongly influence the geometry and stability of flat clusters. Changes in the charge of flat clusters can promote both their folding to spheroidal structures and their dissociation. It is concluded that the fluctuations of electron concentration in carbon plasma can result in the accumulation of fullerene clusters and the dissociation of flat clusters. Computer simulations of fullerene C 60 formation from carbon clusters having different charges are carried out using the program HyperChem 5 to calculate the optimal geometry of molecules and their molecular dynamics at different temperatures [ru

  7. Influence of process parameters on plasma electrolytic surface treatment of tantalum for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, Maciej, E-mail: maciej.sowa@polsl.pl [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland); Woszczak, Maja; Kazek-Kęsik, Alicja [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland); Dercz, Grzegorz [Institute of Materials Science, University of Silesia, 75 Pułku Piechoty Street 1A, 41-500 Chorzów (Poland); Korotin, Danila M. [M.N. Mikheev Institute of Metal Physics of the Ural Branch of Russian Academy of Sciences, S. Kovalevskoi Street 18, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Zhidkov, Ivan S. [Institute of Physics and Technology, Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Kurmaev, Ernst Z. [M.N. Mikheev Institute of Metal Physics of the Ural Branch of Russian Academy of Sciences, S. Kovalevskoi Street 18, 620990 Yekaterinburg (Russian Federation); Institute of Physics and Technology, Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Cholakh, Seif O. [Institute of Physics and Technology, Ural Federal University, Mira Street 19, 620002 Yekaterinburg (Russian Federation); Basiaga, Marcin [Faculty of Biomedical Engineering, Silesian University of Technology, Gen. de Gaulle’a Street 66, 41-800 Zabrze (Poland); Simka, Wojciech, E-mail: wojciech.simka@polsl.pl [Faculty of Chemistry, Silesian University of Technology, B. Krzywoustego Street 6, 44-100 Gliwice (Poland)

    2017-06-15

    Highlights: • 2-step plasma electrolytic oxidation (PEO) of tantalum was investigated. • PEO coatings surface composition were reflected by the composition of anodizing baths. • Hydrophobic surfaces were obtained from acetate and formate containing baths. • Bioactive phases were identified. - Abstract: This work aims to quantify the effect of anodization voltage and electrolyte composition used during DC plasma electrolytic oxidation (PEO), operated as a 2-step process, on the surface properties of the resulting oxide coatings on tantalum. The first step consisted of galvanostatic anodization (150 mA cm{sup −2}) of the tantalum workpiece up to several limiting voltages (200, 300, 400 and 500 V). After attaining the limiting voltage, the process was switched to voltage control, which resulted in a gradual decrease of the anodic current density. The anodic treatment was realized in a 0.5 M Ca(H{sub 2}PO{sub 2}){sub 2} solution, which was then modified by the addition of 1.15 M Ca(HCOO){sub 2} as well as 1.15 M and 1.5 M Mg(CH{sub 3}COO){sub 2}. The increasing voltage of anodization led to the formation of thicker coatings, with larger pores and enriched with electrolytes species to a higher extent. The solutions containing HCOO{sup −} and CH{sub 3}COO{sup −} ions caused the formation of coatings which were slightly hydrophobic (high contact angle). In the case of the samples anodized up to 500 V, scattered crystalline deposits were observed. Bioactive phases, such as hydroxyapatite, were detected in the treated oxide coatings by XRD and XPS.

  8. Statistics on the parameters of nonisothermal ionospheric plasma in large mesospheric electric fields

    Science.gov (United States)

    Martynenko, S.; Rozumenko, V.; Tyrnov, O.; Manson, A.; Meek, C.

    The large V/m electric fields inherent in the mesosphere play an essential role in lower ionospheric electrodynamics. They must be the cause of large variations in the electron temperature and the electron collision frequency at D region altitudes, and consequently the ionospheric plasma in the lower part of the D region undergoes a transition into a nonisothermal state. This study is based on the databases on large mesospheric electric fields collected with the 2.2-MHz radar of the Institute of Space and Atmospheric Studies, University of Saskatchewan, Canada (52°N geographic latitude, 60.4°N geomagnetic latitude) and with the 2.3-MHz radar of the Kharkiv V. Karazin National University (49.6°N geographic latitude, 45.6°N geomagnetic latitude). The statistical analysis of these data is presented in Meek, C. E., A. H. Manson, S. I. Martynenko, V. T. Rozumenko, O. F. Tyrnov, Remote sensing of mesospheric electric fields using MF radars, Journal of Atmospheric and Solar-Terrestrial Physics, in press. The large mesospheric electric fields is experimentally established to follow a Rayleigh distribution in the interval 0 plasma.

  9. Statistical parameters of nonisothermal lower ionospheric plasma in the electrically active mesosphere

    Science.gov (United States)

    Martynenko, S. I.; Rozumenko, V. T.; Tyrnov, O. F.; Manson, A. H.; Meek, C. E.

    The large V/m electric fields inherent in the lower mesosphere play an essential role in lower ionospheric electrodynamics. They must be the cause of large variations in the electron temperature and the electron collision frequency and consequently of the transition of the ionospheric plasma in the lower part of the D region into a nonisothermal state. This study is based on the datasets on large mesospheric electric fields collected with the 2.2-MHz radar of the Institute of Space and Atmospheric Studies, University of Saskatchewan, Canada (52°N geographic latitude, 60.4°N geomagnetic latitude), and with the 2.3-MHz radar of the Kharkiv V. Karazin National University, Ukraine (49.6°N geographic latitude, 45.6°N geomagnetic latitude). The statistical analysis of these data is presented by [Meek, C.E., Manson, A.H., Martynenko, S.I., Rozumenko, V.T., Tyrnov, O.F. Remote sensing of mesospheric electric fields using MF radars. J. Atmos. Solar-Terr. Phys. 66, 881-890, 2004. 10.1016/j.jastp.2004.02.002]. The large mesospheric electric fields in the 60-67-km altitude range are experimentally established to follow a Rayleigh distribution in the 0 < E < 2.5 V/m interval. These data have permitted the resulting differential distributions of relative disturbances in the electron temperature, θ, and the effective electron collision frequency, η, to be determined. The most probable θ and η values are found to be in the 1.4-2.2 interval, and hence the nonstationary state of the lower part of the D region needs to be accounted for in studying processes coupling the electrically active mesosphere and the lower ionospheric plasma.

  10. Measurements of gas parameters in plasma-assisted supersonic combustion processes using diode laser spectroscopy

    International Nuclear Information System (INIS)

    Bolshov, Mikhail A; Kuritsyn, Yu A; Liger, V V; Mironenko, V R; Leonov, S B; Yarantsev, D A

    2009-01-01

    We report a procedure for temperature and water vapour concentration measurements in an unsteady-state combustion zone using diode laser absorption spectroscopy. The procedure involves measurements of the absorption spectrum of water molecules around 1.39 μm. It has been used to determine hydrogen combustion parameters in M = 2 gas flows in the test section of a supersonic wind tunnel. The relatively high intensities of the absorption lines used have enabled direct absorption measurements. We describe a differential technique for measurements of transient absorption spectra, the procedure we used for primary data processing and approaches for determining the gas temperature and H 2 O concentration in the probed zone. The measured absorption spectra are fitted with spectra simulated using parameters from spectroscopic databases. The combustion-time-averaged (∼50 ms) gas temperature and water vapour partial pressure in the hot wake region are determined to be 1050 K and 21 Torr, respectively. The large signal-to-noise ratio in our measurements allowed us to assess the temporal behaviour of these parameters. The accuracy in our temperature measurements in the probed zone is ∼40 K. (laser applications and other topics in quantum electronics)

  11. Prebiotics, Prosynbiotics and Synbiotics: Can They Reduce Plasma Oxidative Stress Parameters? A Systematic Review.

    Science.gov (United States)

    Salehi-Abargouei, Amin; Ghiasvand, Reza; Hariri, Mitra

    2017-03-01

    This study assessed the effectiveness of presybiotics, prosybiotics and synbiotics on reducing serum oxidative stress parameters. PubMed/Medline, Ovid, Google Scholar, ISI Web of Science and SCOPUS were searched up to September 2016. English language randomized clinical trials reporting the effect of presybiotics, prosybiotics or synbiotic interventions on serum oxidative stress parameters in human adults were included. Twenty-one randomized clinical trials met the inclusion criteria for systematic review. Two studies investigated prebiotics, four studies synbiotics and fifteen studies probiotics. According to our systematic review, prebiotic could decrease malondialdehyde and increase superoxidative dismutase, but evidence is not enough. In comparison with fructo-oligosaccharide, inulin is much more useful for oxidative stress reduction. Using probiotics with dairy products could reduce oxidative stress significantly, but probiotic in form of supplementation did not have any effect on oxidative stress. There is limited but supportive evidence that presybiotics, prosybiotics and synbiotics are effective for reducing oxidative stress parameters. Further randomized clinical trials with longer duration of intervention especially on population with increased oxidative stress are needed to provide more definitive results before any recommendation for clinical use of these interventions.

  12. Loading regimen required to rapidly achieve therapeutic trough plasma concentration of teicoplanin and evaluation of clinical features

    Directory of Open Access Journals (Sweden)

    Seki M

    2012-11-01

    Full Text Available Masafumi Seki,1,* Kaori Yabuno,1,2,* Koji Miyawaki,1,2 Yoshihiro Miwa,2 Kazunori Tomono11Division of Infection Control and Prevention, 2Department of Pharmacy, Osaka University Hospital, Suita, Osaka, Japan*These authors contributed equally to this workBackground: A trough concentration of >20 mg/L is considered the optimal dosage of teicoplanin required to ensure early therapeutic effects against methicillin-resistant Staphylococcus aureus (MRSA infections including those in patients who develop febrile neutropenia after chemotherapy. This study determines appropriate initial doses during the first 2 days of administration and evaluates the therapeutic target teicoplanin trough concentration.Method: A 2-day regimen was evaluated in patients treated with 600 mg and 1200 mg or 1200 mg and 600 mg (total 1800 mg, Group 1, 800 mg and 800 mg (total 1600 mg, Group 2, and 800 mg and 400 mg (total 1200 mg, Group 3 of teicoplanin on Days 1 and 2, respectively. We also compared the efficiency and adverse effects at trough concentrations of 15–20 mg/L (Group A, n = 28 with >20 mg/L (Group B, n = 27 of teicoplanin, and also compared them with those on the similar concentrations of vancomycin (Groups C and D, n = 50 and 34, respectively.Results: The mean trough concentrations of teicoplanin on Days 4 or 5 were 22.2, 17.5, and 16.2 mg/L in Groups 1, 2, and 3, respectively. The clinical efficiency was 85.7%, 81.5%, 92.0%, and 91.5%, in Groups A, B, C, and D, respectively. The rates of adverse effects were not high in teicoplanin (nephrotoxicity, 7.1% and 3.7%, and hepatotoxicity, 14.3% and 11.1% in Groups A and B, respectively. However, more adverse effects tended to arise in patients who received vancomycin in nephrotoxicity (14.0% and 11.8%, in Groups C and D, respectively.Conclusion: These results suggest that the 2-day regimens with total 1800 mg achieved the most effective therapeutic trough plasma concentration of teicoplanin (20 mg/L. However, 15–20

  13. Detection of Independent Associations of Plasma Lipidomic Parameters with Insulin Sensitivity Indices Using Data Mining Methodology.

    Directory of Open Access Journals (Sweden)

    Steffi Kopprasch

    Full Text Available Glucolipotoxicity is a major pathophysiological mechanism in the development of insulin resistance and type 2 diabetes mellitus (T2D. We aimed to detect subtle changes in the circulating lipid profile by shotgun lipidomics analyses and to associate them with four different insulin sensitivity indices.The cross-sectional study comprised 90 men with a broad range of insulin sensitivity including normal glucose tolerance (NGT, n = 33, impaired glucose tolerance (IGT, n = 32 and newly detected T2D (n = 25. Prior to oral glucose challenge plasma was obtained and quantitatively analyzed for 198 lipid molecular species from 13 different lipid classes including triacylglycerls (TAGs, phosphatidylcholine plasmalogen/ether (PC O-s, sphingomyelins (SMs, and lysophosphatidylcholines (LPCs. To identify a lipidomic signature of individual insulin sensitivity we applied three data mining approaches, namely least absolute shrinkage and selection operator (LASSO, Support Vector Regression (SVR and Random Forests (RF for the following insulin sensitivity indices: homeostasis model of insulin resistance (HOMA-IR, glucose insulin sensitivity index (GSI, insulin sensitivity index (ISI, and disposition index (DI. The LASSO procedure offers a high prediction accuracy and and an easier interpretability than SVR and RF.After LASSO selection, the plasma lipidome explained 3% (DI to maximal 53% (HOMA-IR variability of the sensitivity indexes. Among the lipid species with the highest positive LASSO regression coefficient were TAG 54:2 (HOMA-IR, PC O- 32:0 (GSI, and SM 40:3:1 (ISI. The highest negative regression coefficient was obtained for LPC 22:5 (HOMA-IR, TAG 51:1 (GSI, and TAG 58:6 (ISI.Although a substantial part of lipid molecular species showed a significant correlation with insulin sensitivity indices we were able to identify a limited number of lipid metabolites of particular importance based on the LASSO approach. These few selected lipids with the closest

  14. A study of the asymmetrical distribution of solar activity features on solar and plasma parameters (1967-2016)

    Science.gov (United States)

    El-Borie, M. A.; El-Taher, A. M.; Aly, N. E.; Bishara, A. A.

    2018-04-01

    The impact of asymmetrical distribution of hemispheric sunspot areas (SSAs) on the interplanetary magnetic field, plasma, and solar parameters from 1967 to 2016 has been studied. The N-S asymmetry of solar-plasma activities based on SSAs has a northern dominance during solar cycles 20 and 24. However, it has a tendency to shift to the southern hemisphere in cycles 21, 22, and 23. The solar cycle 23 showed that the sorted southern SSAs days predominated over the northern days by ˜17%. Through the solar cycles 21-24, the SSAs of the southern hemisphere were more active. In contrast, the northern SSAs predominate over the southern one by 9% throughout solar cycle 20. On the other hand, the average differences of field magnitude for the sorted northern and southern groups during solar cycles 20-24 are statistically insignificant. Clearly, twenty years showed that the solar plasma ion density from the sorted northern group was denser than that of southern group and a highest northern dominant peak occurred in 1971. In contrast, seventeen out of fifty years showed the reverse. In addition, there are fifteen clear asymmetries of solar wind speed (SWS), with SWS (N) > SWS (S), and during the years 1972, 2002, and 2008, the SWS from the sorted northern group was faster than that of southern activity group by 6.16 ± 0.65 km/s, 5.70 ± 0.86 km/s, and 5.76 ± 1.35 km/s, respectively. For the solar cycles 20-24, the grand-averages of P from the sorted solar northern and southern have nearly the same parameter values. The solar plasma was hotter for the sorted northern activity group than the southern ones for 17 years out of 50. Most significant northern prevalent asymmetries were found in 1972 (5.76 ± 0.66 × 103 K) and 1996 (4.7 ± 0.8 × 103 K), while two significant equivalent dominant southern asymmetries (˜3.8 ± 0.3 × 103 K) occurred in 1978 and 1993. The grand averages of sunspot numbers have symmetric activity for the two sorted northern and southern hemispheres

  15. Influence of the arc plasma parameters on the weld pool profile in TIG welding

    International Nuclear Information System (INIS)

    Toropchin, A; Frolov, V; Pipa, A V; Kozakov, R; Uhrlandt, D

    2014-01-01

    Magneto-hydrodynamic simulations of the arc and fluid simulations of the weld pool can be beneficial in the analysis and further development of arc welding processes and welding machines. However, the appropriate coupling of arc and weld pool simulations needs further improvement. The tungsten inert gas (TIG) welding process is investigated by simulations including the weld pool. Experiments with optical diagnostics are used for the validation. A coupled computational model of the arc and the weld pool is developed using the software ANSYS CFX. The weld pool model considers the forces acting on the motion of the melt inside and on the surface of the pool, such as Marangoni, drag, electromagnetic forces and buoyancy. The experimental work includes analysis of cross-sections of the workpieces, highspeed video images and spectroscopic measurements. Experiments and calculations have been performed for various currents, distances between electrode and workpiece and nozzle diameters. The studies show the significant impact of material properties like surface tension dependence on temperature as well as of the arc structure on the weld pool behaviour and finally the weld seam depth. The experimental weld pool profiles and plasma temperatures are in good agreement with computational results

  16. Coagulation parameters as a guide for fresh frozen plasma transfusion practice: A tertiary hospital experience

    Directory of Open Access Journals (Sweden)

    Wan Haslindawani W

    2010-01-01

    Full Text Available Introduction: The appropriate use of blood and blood products means the transfusion of safe blood products only to treat a condition leading to significant morbidity or mortality, which cannot be prevented or managed effectively by other means. The safety and effectiveness of transfusion depend on the appropriate clinical use of blood and blood products. This study was conducted to review the practice of fresh frozen plasma usage (FFP for transfusion, based on the coagulation profile, requested by various departments in the Hospital Universiti Sains Malaysia (HUSM. Methodology: A retrospective review of blood bank records and coagulation profile results of the patients given FFP from October to December 2006, in Hospital USM was undertaken. The criteria set by the College of American Pathologists in 1994, were used as the guidelines. Results: One thousand six hundred and ninety-eight units of FFP were used during this study period. Only 806 (47.47% FFP units were deemed appropriate. 20.38% were based on studies without any coagulation tests prior to transfusion and 21.13% were transfused for mild prolongation of coagulation test results. About 6.41% requested FFP in the setting of normal coagulation results. Conclusion: Our results showed that a significant proportion of the FFP transfusion was not guided by the coagulation profile. We recommend that a continuous education on FFP transfusion may help to guide the appropriate request for FFP.

  17. Effects of fat supplementations on milk production and composition, ruminal and plasma parameters of dairy cows

    Directory of Open Access Journals (Sweden)

    L. Bailoni

    2010-04-01

    Full Text Available The effects on milk yield and quality caused by the same amount (325 g/d/cow of lipids provided by 3 different fat sources (hydrogenate palm fat, HF; calcium salt palm fat, CaSF; full-fat toasted soybean, TS, top dressed to a common total mixed ration, were investigated. Supplementations did not affect feed intake and milk yield, but markedly changed the acidic profile of milk fat. CaSF and TS significantly increased the proportions of unsaturated fatty acids of milk fat with respect to control and to HF. The 3 fat sources did not affect the concentrations of ammonia and VFA of rumen fluid. TS only slightly increased (P<0.10 plasma urea content because of a higher dietary protein supply, with respect to the other treatments. The use of a low amount of toasted and cracked full fat soybean seem to be interesting to increase the energy concentration of diets in replacement to commercial fat products and it can be use to modify the milk fat quality increasing the fraction with benefit effects on human health.

  18. Influence of the arc plasma parameters on the weld pool profile in TIG welding

    Science.gov (United States)

    Toropchin, A.; Frolov, V.; Pipa, A. V.; Kozakov, R.; Uhrlandt, D.

    2014-11-01

    Magneto-hydrodynamic simulations of the arc and fluid simulations of the weld pool can be beneficial in the analysis and further development of arc welding processes and welding machines. However, the appropriate coupling of arc and weld pool simulations needs further improvement. The tungsten inert gas (TIG) welding process is investigated by simulations including the weld pool. Experiments with optical diagnostics are used for the validation. A coupled computational model of the arc and the weld pool is developed using the software ANSYS CFX. The weld pool model considers the forces acting on the motion of the melt inside and on the surface of the pool, such as Marangoni, drag, electromagnetic forces and buoyancy. The experimental work includes analysis of cross-sections of the workpieces, highspeed video images and spectroscopic measurements. Experiments and calculations have been performed for various currents, distances between electrode and workpiece and nozzle diameters. The studies show the significant impact of material properties like surface tension dependence on temperature as well as of the arc structure on the weld pool behaviour and finally the weld seam depth. The experimental weld pool profiles and plasma temperatures are in good agreement with computational results.

  19. Determination of reference ranges for full blood count parameters in neonatal cord plasma in Hilla, Babil, Iraq

    Science.gov (United States)

    Al-Marzoki, Jasim M; Al-Maaroof, Zainab W; Kadhum, Ali H

    2012-01-01

    Background The health of an individual is known to vary in different countries, in the same country at different times, and in the same individuals at different ages. This means that the condition of individuals must be related to or compared with reference data. Determination of a reference range for the healthy term newborn is clinically important in terms of various complete blood count parameters. The purpose of this study was to establish a local reference range for full blood count parameters in neonatal cord plasma in Hilla, Babil, Iraq. Methods A total of 220 mothers and their neonates were enrolled in this cross-sectional study from February 2011 to January 2012. Maternal inclusion criteria were age 15–45 years, an uneventful pregnancy, and hemoglobin ≥ 10 g. Neonatal inclusion criteria were full term (37–42 weeks) and normal birth weight. The umbilical cord was immediately clamped after delivery of the baby; 3 mL of cord blood was then taken from the umbilical vein and collected in a tube containing ethylenediamine tetra-acetic acid, its plasma was analyzed for full blood count parameters by standard Coulter gram, and the differential leukocyte count was done manually. Results Mean neonatal hemoglobin was 13.88 ± 1.34 (range 11–17.3) g/dL and mean white cell count was 10.12 ± 2.8 (range 3.1–21.6) × 109/L. Mean platelet count was 267.63 ± 60.62 (range 152–472) × 109/L. No significant differences in red cell, white cell, or platelet counts were found between males and females, except for neutrophil count. The current study shows lower levels of hemoglobin, white cells, and red cells compared with other studies, and there is agreement with some studies and disagreement with others concerning platelet count. Conclusion Most results in the current study were within the reference range. The hematological reference values for Iraqi neonatal cord plasma need to be confirmed by larger numbers of blood samples and by collecting samples from

  20. Correlating neutron yield and reliability for selecting experimental parameters for a plasma focus machine

    International Nuclear Information System (INIS)

    Pross, G.

    Possibilities of optimizing focus machines with a given energy content in the sense of high neutron yield and high reliability of the discharges are investigated experimentally. For this purpose, a focus machine of the Mather type with an energy content of 12 kJ was constructed. The following experimental parameters were varied: the material of the insulator in the ignition zone, the structure of the outside electrode, the length of the inside electrode, the filling pressure and the amount and polarity of the battery voltage. An important part of the diagnostic program consists of measurements of the azimuthal and axial current distribution in the accelerator, correlated with short-term photographs of the luminous front as a function of time. The results are given. A functional schematic has been drafted for focus discharge as an aid in extensive optimization of focus machines, combining findings from theory and experiments. The schematic takes into account the multiparameter character of the discharge and clarifies relationships between the experimental parameters and the target variables neutron yield and reliability

  1. Calculating the jet quenching parameter in the plasma of noncommutative Yang-Mills theory from gauge/gravity duality

    Science.gov (United States)

    Chakraborty, Somdeb; Roy, Shibaji

    2012-02-01

    A particular decoupling limit of the nonextremal (D1, D3) brane bound state system of type IIB string theory is known to give the gravity dual of space-space noncommutative Yang-Mills theory at finite temperature. We use a string probe in this background to compute the jet quenching parameter in a strongly coupled plasma of hot noncommutative Yang-Mills theory in (3+1) dimensions from gauge/gravity duality. We give expressions for the jet quenching parameter for both small and large noncommutativity. For small noncommutativity, we find that the value of the jet quenching parameter gets reduced from its commutative value. The reduction is enhanced with temperature as T7 for fixed noncommutativity and fixed ’t Hooft coupling. We also give an estimate of the correction due to noncommutativity at the present collider energies like in RHIC or in LHC and find it too small to be detected. We further generalize the results for noncommutative Yang-Mills theories in diverse dimensions.

  2. Preliminary tests of the electrostatic plasma accelerator

    Science.gov (United States)

    Aston, G.; Acker, T.

    1990-01-01

    This report describes the results of a program to verify an electrostatic plasma acceleration concept and to identify those parameters most important in optimizing an Electrostatic Plasma Accelerator (EPA) thruster based upon this thrust mechanism. Preliminary performance measurements of thrust, specific impulse and efficiency were obtained using a unique plasma exhaust momentum probe. Reliable EPA thruster operation was achieved using one power supply.

  3. Optimizing the Parameters in Heat Treatment for Achieving High Hardness and Efficient Bending of Thin BS 2014 Aluminium Alloy Sheets

    Directory of Open Access Journals (Sweden)

    Abirami Priyadarshini B.

    2016-05-01

    Full Text Available The present work targets in setting a standard heat treatment procedure for obtaining high hardness values of the order of 80 HRB in BS 2014 aluminium alloy sheets of 2mm thick commonly used in aerospace industries. A hardness range of 60HRB to 72HRB is possible in low thickness sheets as stated in the standard BS EN 485-2:2013. Experiments were performed to achieve higher hardness values by controlling the heat treatment temperatures thereby understanding the ageing mechanism of the Al-Cu alloy to a wider extent. The validated process sequence in turn resulted in complications where bending of the sheets resulted in cracking. Further investigation was performed and it was found that the BS 2014 alloy has to be bent within two hours of solution annealing in order to have an efficient bending. The results showed that the natural ageing is so rapid in this alloy, which strengthens the material so quickly by the formation of CuAl2 precipitates, thereby, demanding the bending procedure to be performed before the growth of precipitates becomes dominant.

  4. Achievement report for fiscal 1982 on Sunshine Program. Basic research on plasma-aided coal gasification technology; 1982 nendo sekitan no plasma gas ka gijutsu no kiso kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1983-03-01

    A technology is developed to produce useful gases such as acetylene, hydrogen, and carbon monoxide from coal and coal-related substances making use of the high-temperature high-density energy of plasma jets. Using the newly developed systems, the energy utilization rate is 50% or higher and the yields are 60-100g/kWh for acetylene and 100-160l/kWh for hydrogen. For the achievement of the goal, two types of plasma gasification systems have been developed. One is a '100kW 3-torch plasma gasification system' in which the specimen for gasification is fed to the center of the combined flame for improvement on the contact rate between the specimen and plasma flame. The other is a 'rotating plasma torch system' in which the flame is rotated, and expanded, by an externally provided magnetic field for improvement on the contact rate between the specimen and plasma flame and, simultaneously, for an increase in energy utilization efficiency by feeding the specimen into the discharge region. In this fiscal year, quenching tests are conducted using water and oil so as to establish the difference in quenching effect between quenching agents. What to improve in the systems are clarified. (NEDO)

  5. Parameters of the constricted plasma discharge produced by radio-frequency for atmospheric pressures

    International Nuclear Information System (INIS)

    Zambrano R, G.

    1987-01-01

    The main electrophysical characteristics of high-frequency discharge between two electrodes for pressures of the order of atmospheric pressure were investigated. The vibrational and kinetic temperatures of the discharge, and the possibilities for creating the conditions which using these type of discharge an instability between vibrational and kinetic temperatures can be obtained. For determining main characteristics of this type of discharge, argon gas, nitrogen gas and air, when oxygen and nitrogen are predominated, were used. The obtained electrical discharge parameters were: the high frequency voltage between electrocathodes, the current, the phase displacement between current and voltage, and the discharge power. The kinetic temperature distribution in the discharge region, and the vibrational temperature of the nitrogen molecules in discharge channel were also obtained. (M.C.K.) [pt

  6. Solar wind parameters responsible for the plasma injection into the magnetospheric ring current region

    International Nuclear Information System (INIS)

    Bobrov, M.S.

    1977-01-01

    Solar wind effect on the magnetospheric ring-current region has been considered. The correlations with solar wind parameters of the magnitude qsub(o) proportional to the total energy of particles being injected into the magnetospheric ring-current region per one hour are studied statistically and by comparison of time variations. The data on 8 sporadic geomagnetic storms of various intensity, from moderate to very severe one, are used. It is found that qsub(o) correlates not only with the magnitude and the direction of the solar-wind magnetic field component normal to the ecliptic plane, Bsub(z), but also with the variability, sigmasub(B), of the total magnetic-field strength vector. The solar-wind flux velocity ν influences the average storm intensity but the time variations of ν during any individual storm do not correlate with those of qsub(o)

  7. Production of aerosols by optical catapulting: Imaging, performance parameters and laser-induced plasma sampling rate

    International Nuclear Information System (INIS)

    Abdelhamid, M.; Fortes, F.J.; Fernández-Bravo, A.; Harith, M.A.; Laserna, J.J.

    2013-01-01

    Optical catapulting (OC) is a sampling and manipulation method that has been extensively studied in applications ranging from single cells in heterogeneous tissue samples to analysis of explosive residues in human fingerprints. Specifically, analysis of the catapulted material by means of laser-induced breakdown spectroscopy (LIBS) offers a promising approach for the inspection of solid particulate matter. In this work, we focus our attention in the experimental parameters to be optimized for a proper aerosol generation while increasing the particle density in the focal region sampled by LIBS. For this purpose we use shadowgraphy visualization as a diagnostic tool. Shadowgraphic images were acquired for studying the evolution and dynamics of solid aerosols produced by OC. Aluminum silicate particles (0.2–8 μm) were ejected from the substrate using a Q-switched Nd:YAG laser at 1064 nm, while time-resolved images recorded the propagation of the generated aerosol. For LIBS analysis and shadowgraphy visualization, a Q-switched Nd:YAG laser at 1064 nm and 532 nm was employed, respectively. Several parameters such as the time delay between pulses and the effect of laser fluence on the aerosol production have been also investigated. After optimization, the particle density in the sampling focal volume increases while improving the aerosol sampling rate till ca. 90%. - Highlights: • Aerosol generation by optical catapulting has been successfully optimized. • We study the evolution and dynamics of solid aerosols produced by OC. • We use shadowgraphy visualization as a diagnostic tool. • Effects of temporal conditions and laser fluence on the elevation of the aerosol cloud have been investigated. • The observed LIBS sampling rate increased from 50% reported before to approximately 90%

  8. Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

    Directory of Open Access Journals (Sweden)

    Partha Saikia

    2016-04-01

    Full Text Available We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te, electron density (ne, ion density (ni, degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

  9. Temporal follow-up of plasma parameter in an nuclear grade aluminum laser induced plasma at different laser energies by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Karki, Vijay; Singh, Manjeet; Sarkar, Arnab

    2015-07-01

    We report spectroscopic studies of laser induced plasma (LIP) produced by ns – 532 nm - Nd:YAG laser light pulses for different laser energies (35, 45 and 60 mJ) on an nuclear grade aluminum sample in air at atmospheric pressure. The temporal history of the plasma is obtained by recording the emission features at predetermined delays and at a fixed gate width (2.5 ì s). The temporal profiles of excitation temperature (T e ), ionization temperature (T ion ) and electron number density (N e ) were determined from Boltzmann plot, Saha-Boltzmann equation and Stark broadening method, respectively. T e , T ion and N e , shows a power law decay pattern with increasing acquisition time delay. T e has a positive correlation with laser energy, but the T ion and N e differ negligibly from one laser energy to another. Again the rate of decay of T e increases with increasing laser energy but that of T ion is much slower and independent of laser energy. The follow up of the local thermodynamic equilibrium (LTE) conditions were evaluated using both McWhirter criterion and T e /T ion ratio for different delays and different energies to determine the temporal range in which LTE is satisfied. Both the methods concluded very similar results except for very high energy and small delay conditions, where T e /T ion ratio deviates from unity indicating non-LTE condition. The relative transition probabilities of Al transition (3sp4s: 4 P 2/5 →3sp 2 : 4P 3/2,5/2 ) and (4s: 2 S 1/2 → 3p: 2 P 1/2,3/2 ) were estimated and are in excellent agreement with the Kurucz database. These investigations provide an insight to optimize various parameters during LIBS analysis of aluminum based matrices. (author)

  10. Systematic Investigation on the Influence of Spray Parameters on the Mechanical Properties of Atmospheric Plasma-Sprayed YSZ Coatings

    Science.gov (United States)

    Mutter, Markus; Mauer, Georg; Mücke, Robert; Guillon, Olivier; Vaßen, Robert

    2018-04-01

    In the atmospheric plasma spray (APS) process, micro-sized ceramic powder is injected into a thermal plasma where it is rapidly heated and propelled toward the substrate. The coating formation is characterized by the subsequent impingement of a large number of more or less molten particles forming the so-called splats and eventually the coating. In this study, a systematic investigation on the influence of selected spray parameters on the coating microstructure and the coating properties was conducted. The investigation thereby comprised the coating porosity, the elastic modulus, and the residual stress evolution within the coating. The melting status of the particles at the impingement on the substrate in combination with the substrate surface condition is crucial for the coating formation. Single splats were collected on mirror-polished substrates for selected spray conditions and evaluated by identifying different types of splats (ideal, distorted, weakly bonded, and partially molten) and their relative fractions. In a previous study, these splat types were evaluated in terms of their effect on the above-mentioned coating properties. The particle melting status, which serves as a measure for the particle spreading behavior, was determined by in-flight particle temperature measurements and correlated to the coating properties. It was found that the gun power and the spray distance have a strong effect on the investigated coating properties, whereas the feed rate and the cooling show minor influence.

  11. Therapeutic effects of marshmallow (Althaea officinalis L.) extract on plasma biochemical parameters of common carp infected with Aeromonas hydrophila.

    Science.gov (United States)

    Banaee, Mahdi; Soleimany, Vahid; Nematdoost Haghi, Behzad

    2017-01-01

    This study evaluated preclinical and clinical safety of marshmallow ( Althaea officinalis L.) extract as a naturopathic medicine in common carp deliberately infected with Aeromonas hydrophila . The fish were fed 0 (control), 2.50, 5.00 and 10.00 g of marshmallow extract for 60 days in a preclinical experiment and then, challenged with A. hydrophila for a 10-day experiment. Significant increases were observed in aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), creatine phosphokinase (CPK) activities and plasma creatinine levels in fish fed 10 g marshmallow extract per kg feed. However, alanine aminotransferase (ALT) significantly decreased on day 60. The fish fed 2.50 g marshmallow extract per kg feed indicated increased levels of total protein and globulin. There were no significant changes in albumin levels ( p > 0.05). 2.50 and 5.00 g marshmallow significantly decreased triglyceride and cholesterol levels and increased glucose levels ( p Marshmallow extract at 5.00 and 10.00 g can adjust plasma biochemical parameters in fish challenged with A. hydrophila . The results of preclinical studies and pharmaceutical toxicity of marshmallow extract revealed that dietary levels lower than 5.00 g were safe and effective. The results of this clinical study demonstrated that marshmallow extract (5.00 g kg -1 feed) can protect fish against A. hydrophila .

  12. Evaluation of the Effect of Different Plasma-Nitriding Parameters on the Properties of Low-Alloy Steel

    Science.gov (United States)

    Zdravecká, Eva; Slota, Ján; Solfronk, Pavel; Kolnerová, Michaela

    2017-07-01

    This work is concerned with the surface treatment (ion nitriding) of different plasma-nitriding parameters on the characteristics of DIN 1.8519 low-alloy steel. The samples were nitrided from 500 to 570 °C for 5-40 h using a constant 25% N2-75% H2 gaseous mixture. Lower temperature (500-520 °C) favors the formation of compound layers of γ' and ɛ iron nitrides in the surface layers, whereas a monophase γ'-Fe4 N layer can be obtained at a higher temperature. The hardness of this layer can be obtained when nitriding is performed at a higher temperature, and the hardness decreases when the temperature increases to 570 °C. These results indicate that pulsed plasma nitriding is highly efficient at 550 °C and can form thick and hard nitrided layers with satisfactory mechanical properties. The results show the optimized nitriding process at 540 °C for 20 h. This process can be an interesting means of enhancing the surface hardness of tool steels to forge dies compared to stamped steels with zinc coating with a reduced coefficient of friction and improving the anti-sticking properties of the tool surface.

  13. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with neon

    International Nuclear Information System (INIS)

    Malinina, A. A.; Malinin, A. N.

    2013-01-01

    Results are presented from studies of the optical characteristics and parameters of plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with neon—the working medium of a non-coaxial exciplex gas-discharge emitter. The electron energy distribution function, the transport characteristics, the specific power losses for electron processes, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering by the working mixture components are determined as functions of the reduced electric field. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules is found to be 1.6 × 10 −14 m 3 /s for a reduced electric field of E/N = 15 Td, at which the maximum emission intensity in the blue-green spectral region (λ max = 502 nm) was observed in this experiment

  14. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with neon

    Science.gov (United States)

    Malinina, A. A.; Malinin, A. N.

    2013-12-01

    Results are presented from studies of the optical characteristics and parameters of plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with neon—the working medium of a non-coaxial exciplex gas-discharge emitter. The electron energy distribution function, the transport characteristics, the specific power losses for electron processes, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering by the working mixture components are determined as functions of the reduced electric field. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules is found to be 1.6 × 10-14 m3/s for a reduced electric field of E/ N = 15 Td, at which the maximum emission intensity in the blue-green spectral region (λmax = 502 nm) was observed in this experiment.

  15. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with neon

    Energy Technology Data Exchange (ETDEWEB)

    Malinina, A. A., E-mail: alexandr_malinin@rambler.ru; Malinin, A. N. [Uzhhorod National University (Ukraine)

    2013-12-15

    Results are presented from studies of the optical characteristics and parameters of plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with neon—the working medium of a non-coaxial exciplex gas-discharge emitter. The electron energy distribution function, the transport characteristics, the specific power losses for electron processes, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering by the working mixture components are determined as functions of the reduced electric field. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules is found to be 1.6 × 10{sup −14} m{sup 3}/s for a reduced electric field of E/N = 15 Td, at which the maximum emission intensity in the blue-green spectral region (λ{sub max} = 502 nm) was observed in this experiment.

  16. Effect of suspension characteristics on in-flight particle properties and coating microstructures achieved by suspension plasma spray

    Science.gov (United States)

    Aubignat, E.; Planche, M. P.; Allimant, A.; Billières, D.; Girardot, L.; Bailly, Y.; Montavon, G.

    2014-11-01

    This paper focuses on the influence of suspension properties on the manufacturing of coatings by suspension plasma spraying (SPS). For this purpose, alumina suspensions were formulated with two different liquid phases: water and ethanol. Suspensions were atomized with a twin-fluid nozzle and injected in an atmospheric plasma jet. Suspension injection was optimized thanks to shadowgraphy observations and drop size distribution measurements performed by laser diffraction. In-flight particle velocities were evaluated by particle image velocimetry. In addition, splats were collected on glass substrates, with the same conditions as the ones used during the spray process. Scanning electron microscopy (SEM) and profilometry analyses were then performed to observe the splat morphology and thus to get information on plasma / suspension interactions, such as particle agglomeration. Finally, coatings were manufactured, characterized by SEM and compared to each other.

  17. Determination of parameters influencing methylation and demethylation in tropical lakes in Brazil and Nicaragua. Highlights and achievements

    International Nuclear Information System (INIS)

    Hylander, Lars D.

    2002-01-01

    Full text: Scientific background and scope of the project: A well planned field campaign is a highlight for any researcher working in the field. Correctly sampled and identified samples are the true base for high quality research. Poorly collected samples can never be corrected, no matter how much resources are spent on sample preparation and analysing equipment. With experience from several field campaigns, I think the following points might be helpful to achieve scientific results worth publishing: Information. INFORM all participants in a field campaign on their area of responsibility, material to bring, dates and times, etc. The coordinator has the main responsibility for informing the participants. And the participants should confirm received information. Make a detailed research plan and do not expect anybody to perform sampling if this has not been combined, preferably written to avoid misunderstandings due to expected tacitly implied agreements. The coordinator may delegate to another person to compile the plan, in which case it certainly should bear the name of that person; Make a PLAN with aim, objectives, and expected outcomes. Search for existing data and literature from the area and identify where additional research is needed. Compile then a scheme with methods to use, relevant to the objectives and existing funds. High quality research can be done with limited funds! Continue with a list on materials to bring with you to the field and a realistic time schedule. (Since I am a time optimist I never realize that research always lasts twice as long as expected.); Get hold of a topographic MAP, e.g. at the National Survey, and identify suitable sampling points (incl a few alternative ones); Organize a PLANNING MEETING with participating persons to discuss the plan and define the area of responsibility for each one; Take short and concise NOTES from all meetings, which relate treated matters and made agreements and decisions. The one writing the notes and

  18. Princeton Plasma Physics Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

  19. Princeton Plasma Physics Laboratory

    International Nuclear Information System (INIS)

    1990-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990

  20. Plasma Fibrinolysis Parameters in Smokers and Non-smokers of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study.

    Science.gov (United States)

    Delgado, Graciela E; Siekmeier, Rüdiger; Krämer, Bernhard K; März, Winfried; Kleber, Marcus E

    2015-01-01

    Cardiovascular diseases (CVD) are an important cause of morbidity and mortality worldwide. Parameters of coagulation and fibrinolysis are risk factors of CVD and might be affected by cigarette smoking. Aim of our study was to analyze the effect of cigarette smoking on parameters of fibrinolysis in active smokers (AS) and life-time non-smokers (NS) of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study as well as the use of these parameters for risk prediction. We determined plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen (t-PA), protein C activity, and D-dimers in 3,316 LURIC patients. Smoking status was assessed by a questionnaire and measurement of plasma cotinine concentration. Cox regression was used to assess the effect of parameters on mortality. We found that of the 3,316 LURIC patients 777 were AS and 1,178 NS. Within the observation period of 10 years (median) 221 AS and 302 NS died. In male AS vs. NS, PAI-1 (19.0 (10.0-35.0) vs. 15.0 (9.0-29.0) U/ml; p=0.026) and t-PA antigen (12.7 (9.6-16.3) vs. 11.6 (8.9-14.6) μg/l; p=0.020) were slightly increased, while t-PA activity was slightly decreased (0.63 (0.30-1.05) vs. 0.68 (0.42-1.10) U/l; p=0.005). In female AS vs. NS, t-PA antigen (10.5 (8.3-13.9) vs. 11.5 (8.8-15.0) μg/l; p=0.025) and protein C (108.0±24.1% vs. 118.0±25.7%; p=0.004) were decreased. All parameters except for protein C were predictive for mortality in AS. Fully adjusted hazard ratios (95% CI) were 1.14 (1.04-1.25), 1.19 (1.06-1.34), and 1.29 (1.11-1.49) per 1SD increase for D-dimer, t-PA, and PAI-1, respectively. Including fibrinolysis parameters in risk prediction models for mortality improved the area-under-the-curve (AUC) significantly compared with the conventional risk factors. In conclusion, we found alterations in the fibrinolytic system in smokers, which were more pronounced in male AS. PAI-1, t-PA and D-dimers were significant predictors of mortality in AS in LURIC and should be

  1. Measurement of macroscopic plasma parameters with a radio experiment: Interpretation of the quasi-thermal noise spectrum observed in the solar wind

    Science.gov (United States)

    Couturier, P.; Hoang, S.; Meyer-Vernet, N.; Steinberg, J. L.

    1983-01-01

    The ISEE-3 SBH radio receiver has provided the first systematic observations of the quasi-thermal (plasma waves) noise in the solar wind plasma. The theoretical interpretation of that noise involves the particle distribution function so that electric noise measurements with long antennas provide a fast and independent method of measuring plasma parameters: densities and temperatures of a two component (core and halo) electron distribution function have been obtained in that way. The polarization of that noise is frequency dependent and sensitive to the drift velocity of the electron population. Below the plasma frequency, there is evidence of a weak noise spectrum with spectral index -1 which is not yet accounted for by the theory. The theoretical treatment of the noise associated with the low energy (thermal) proton population shows that the moving electrical antenna radiates in the surrounding plasma by Carenkov emission which becomes predominant at the low frequencies, below about 0.1 F sub P.

  2. Stability assessment and operating parameter optimization on experimental results in very small plasma focus, using sensitivity analysis

    Science.gov (United States)

    Jafari, Hossein; Habibi, Morteza

    2018-04-01

    Regarding the importance of stability in small-scale plasma focus devices for producing the repeatable and strength pinching, a sensitivity analysis approach has been used for applicability in design parameters optimization of an actually very low energy device (84 nF, 48 nH, 8-9.5 kV, ∼2.7-3.7 J). To optimize the devices functional specification, four different coaxial electrode configurations have been studied, scanning an argon gas pressure range from 0.6 to 1.5 mbar via the charging voltage variation study from 8.3 to 9.3 kV. The strength and efficient pinching was observed for the tapered anode configuration, over an expanded operating pressure range of 0.6 to 1.5 mbar. The analysis results showed that the most sensitive of the pinch voltage was associated with 0.88 ± 0.8mbar argon gas pressure and 8.3-8.5 kV charging voltage, respectively, as the optimum operating parameters. From the viewpoint of stability assessment of the device, it was observed that the least variation in stable operation of the device was for a charging voltage range of 8.3 to 8.7 kV in an operating pressure range from 0.6 to 1.1 mbar.

  3. Association of Seminal Plasma Total Antioxidant Capacity and Malondialdehyde Levels With Sperm Parameters in Infertile Men With Varicocele

    Directory of Open Access Journals (Sweden)

    Salimi

    2016-05-01

    Full Text Available Background Varicocele is one of the most common reasons for male infertility and could impair spermatogenesis through mechanisms that are not well known. Recently, oxidative stress has been introduced as a major reason for male infertility caused by varicocele. Objectives In the current study, we aimed to assess the TAC (total antioxidant capacity and MDA (malondialdehyde as stress oxidative markers in infertile men with varicocele and fertile men, and moreover, their correlation with sperm parameters. Patients and Methods This case control study was performed on 43 infertile men with varicocele and 46 men with proven fertility. The ferric reducing ability of plasma (FRAP and thiobarbituric acid (TBA reaction methods were used for seminal plasma TAC and MDA assay, respectively. Results Lower TAC levels (1.7 ± 0.2 vs. 1.3 ± 0.4 mmol/L, P = 0.0004 and higher MDA levels (2.5 ± 1.1 vs. 5.8 ± 1.9 mmol/L, P < 0.0001 were observed in infertile men with varicocele compared to fertile men. There was no correlation between TAC and MDA in fertile men (r = 0.02, P = 0.9, however, a negative correlation was found between TAC and MDA levels in varicocele infertile men (r = −0.44, P = 0.003. Moreover, a positive correlation was found between sperm count and sperm motility with TAC levels in varicocele infertile men (r = 0.4, P = 0.02 and r = 0.6, P < 0.0001, respectively. There was a correlation between sperm motility and TAC levels in fertile men (r = 0.5, P = 0.001, but other parameters did not correlate with TAC in this group. A negative correlation was shown between semen volume, sperm count, total sperm, sperm motility, and sperm morphology with MDA levels in varicocele infertile men (r = 0.3, P = 0.045; r = −0.4, P = 0.009; r = −0.5, P = 0.002; r = −0.5, P = 0.001 and r = −0.4, P = 0.008, respectively. There was no correlation between these parameters and MDA in fertile men. Conclusions Our findings indicated that oxidative stress could

  4. The Role of Spraying Parameters and Inert Gas Shrouding in Hybrid Water-Argon Plasma Spraying of Tungsten and Copper for Nuclear Fusion Applications

    Czech Academy of Sciences Publication Activity Database

    Matějíček, Jiří; Kavka, Tetyana; Bertolissi, Gabriele; Ctibor, Pavel; Vilémová, Monika; Mušálek, Radek; Nevrlá, Barbara

    2013-01-01

    Roč. 22, č. 5 (2013), s. 744-755 ISSN 1059-9630 R&D Projects: GA MPO FR-TI2/702; GA TA ČR TA01010300 Institutional support: RVO:61389021 Keywords : plasma spraying * tungsten * copper * inert gas shrouding * water-argon plasma torch * gas shroud * hybrid plasma torch * influence of spray parameters * nuclear fusion * oxidation Subject RIV: JG - Metallurgy Impact factor: 1.491, year: 2013 http://link.springer.com/content/pdf/10.1007%2Fs11666-013-9895-x.pdf

  5. Global parameter optimization of a Mather-type plasma focus in the framework of the Gratton–Vargas two-dimensional snowplow model

    International Nuclear Information System (INIS)

    Auluck, S K H

    2014-01-01

    Dense plasma focus (DPF) is known to produce highly energetic ions, electrons and plasma environment which can be used for breeding short-lived isotopes, plasma nanotechnology and other material processing applications. Commercial utilization of DPF in such areas would need a design tool that can be deployed in an automatic search for the best possible device configuration for a given application. The recently revisited (Auluck 2013 Phys. Plasmas 20 112501) Gratton–Vargas (GV) two-dimensional analytical snowplow model of plasma focus provides a numerical formula for dynamic inductance of a Mather-type plasma focus fitted to thousands of automated computations, which enables the construction of such a design tool. This inductance formula is utilized in the present work to explore global optimization, based on first-principles optimality criteria, in a four-dimensional parameter-subspace of the zero-resistance GV model. The optimization process is shown to reproduce the empirically observed constancy of the drive parameter over eight decades in capacitor bank energy. The optimized geometry of plasma focus normalized to the anode radius is shown to be independent of voltage, while the optimized anode radius is shown to be related to capacitor bank inductance. (paper)

  6. High-resolution Thomson scattering system on the COMPASS tokamak: Evaluation of plasma parameters and error analysis

    Czech Academy of Sciences Publication Activity Database

    Aftanas, Milan; Böhm, Petr; Bílková, Petra; Weinzettl, Vladimír; Zajac, Jaromír; Žáček, František; Stöckel, Jan; Hron, Martin; Pánek, Radomír; Scannell, R.; Walsh, M.

    2012-01-01

    Roč. 83, č. 10 (2012), 10E350-10E350 ISSN 0034-6748. [Topical Conference High-Temperature Plasma Diagnostics/19./. Monterey, 06.05.2012-10.05.2012] R&D Projects: GA ČR GA202/09/1467; GA MŠk 7G10072 Institutional research plan: CEZ:AV0Z20430508 Keywords : error analysis * Monte Carlo methods * plasma density * plasma diagnostics * plasma temperature * plasma toroidal confinement * Tokamak devices Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.602, year: 2012 http://dx.doi.org/10.1063/1.4743956

  7. Correlation of Seminal Plasma Total Antioxidant Capacity and Malondialdehyde Levels With Sperm Parameters in Men With Idiopathic Infertility

    Directory of Open Access Journals (Sweden)

    Fazeli

    2016-01-01

    Full Text Available Background Oxidative stress is the result of an imbalance between the production and scavenging of reactive oxygen species (ROS. Recently, oxidative stress has been introduced as a major cause of male infertility. Objectives The aim of the present study was to determine the correlation between total antioxidant capacity (TAC and malondialdehyde (MDA as markers of oxidative stress in relation to idiopathic male infertility and sperm parameters. Patients and Methods This case control study was conducted using 35 men with idiopathic infertility and 34 men with proven fertility. Seminal plasma TAC and MDA were measured by ferric reducing ability of plasma (FRAP and thiobarbituric acid (TBA reaction methods, respectively. Results Seminal TAC levels were significantly lower and seminal MDA levels were significantly higher in men with idiopathic infertility than in fertile men (P < 0.0001 and P = 0.004, respectively. A positive correlation was shown between sperm motility, sperm morphology, and TAC levels in men with idiopathic infertility (P = 0.002 and P = 0.002, respectively. In addition, there was a correlation between sperm motility and TAC levels in fertile men (P = 0.005. There was no correlation between sperm count and TAC levels in either men with idiopathic infertility or in fertile men. Negative correlations were observed between MDA levels and sperm motility, morphology, and sperm count only in men with idiopathic infertility (P = 0.003, P = 0.001, and P = 0.006, respectively. Conclusions Our results show that oxidative stress could play an important role in male infertility as well as in sperm motility and sperm morphology.

  8. Liver morphology and morphometry and plasma biochemical parameters of Wistar rats that received leaf infusion of Rudgea viburnoides Benth. (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Juliana Castro Monteiro

    2009-04-01

    Full Text Available Rudgea viburnoides leaves are widely used in popular Brazilian medicine as a diuretic, antirheumatic, hypotensive and blood depurative tea. The present study was carried out to investigate the effects of this infusion on the liver and on the plasma biochemical parameters of Wistar rats. Two groups received the R. viburnoides leaf infusion at a daily dose of 10 or 20g dry-leaves/L water, during 40 days. The histopathological analysis did not show degenerated areas or infiltration of leucocytes. Hepatic morphometry showed accumulation of fat in the hepatocytes of the treated groups. There was no significant change in the plasma levels of urea, creatinin, uric acid, direct bilirubin, cholesterol, total proteins, albumin, gamma glutamyl tranferase (gamma-GT, alanine transaminase (ALT, aspartate transaminase (AST, chlorine, phosphate and calcium. A significant reduction in the plasma levels of triacylglycerol (TAG occurred in the group that received the higher dose.As folhas de Rudgea viburnoides Benth. são utilizadas na medicina popular como diuréticas, hipotensoras, anti-reumáticas, depurativas do sangue e em regimes de emagrecimento. O presente estudo foi delineado para avaliar o efeito da infusão das folhas de R. viburnoides nos parâmetros bioquímicos plasmáticos e na morfologia e morfometria hepática de ratos Wistar adultos. Dois grupos receberam a infusão das folhas, diariamente, nas dosagens de 10 e 20 g de folhas secas/L de água, durante 40 dias. O grupo controle recebeu a mesma quantidade de água. As análises histopatológicas não mostraram áreas degeneradas e infiltrados inflamatórios. A morfometria hepática mostrou acúmulo significativo de gordura nos hepatócitos dos animais tratados, principalmente no grupo que recebeu a maior dose da infusão (8,75% de gotículas lipídicas, comparado com 0,25% delas encontradas nos animais controles. Não foram observadas alterações nos níveis plasmáticos de uréia, creatinina,

  9. Effect of styrene exposure on plasma parameters, molecular mechanisms and gene expression in rat model islet cells.

    Science.gov (United States)

    Niaz, Kamal; Hassan, Fatima Ismail; Mabqool, Faheem; Khan, Fazlullah; Momtaz, Saeideh; Baeeri, Maryam; Navaei-Nigjeh, Mona; Rahimifard, Mahban; Abdollahi, Mohammad

    2017-09-01

    Styrene is an aromatic hydrocarbon compound present in the environment and have primary exposure through plastic industry. The current study was designed to evaluate styrene-induced toxicity parameters in rat plasma fasting blood glucose (FBG) level, oral glucose tolerance, insulin secretion, oxidative stress, and inflammatory cytokines in cellular and molecular levels. Styrene was dissolved in corn oil and administered at different doses (250, 500, 1000, 1500, 2000mg/kg/day and control) to each rat, for 42days. In treated groups, styrene significantly increased fasting blood glucose, plasma insulin (p<0.001) and glucose tolerance. Glucose tolerance, insulin resistance and hyperglycemia were found to be the main consequences correlating gene expression of islet cells. Styrene caused a significant enhancement of oxidative stress markers (p<0.001) and inflammatory cytokines in a dose and concentration-dependent manner in plasma (p<0.001). Moreover, the activities of caspase-3 and -9 of the islet cells were significantly up-regulated by this compound at 1500 and 2000mg/kg/day styrene administrated groups (p<0.001). The relative fold change of GLUD1 was downregulated (p<0.05) and upregulated at 1500 and 2000mg/kg, respectively (p<0.01). The relative fold changes of GLUT2 were down regulated at 250 and 1000mg/kg and up regulated in 500, 1500 and 2000mg/kg doses of styrene (p<0.01). The expression level of GCK indicated a significant upregulation at 250mg/kg and downregulation of relative fold changes in the remaining doses of styrene, except for no change at 2000mg/kg of styrene for GCK. Targeting genes (GLUD1, GLUT2 and GCK) of the pancreatic islet cells in styrene exposed groups, disrupted gluconeogenesis, glycogenolysis pathways and insulin secretory functions. The present study illustrated that fasting blood glucose, insulin pathway, oxidative balance, inflammatory cytokines, cell viability and responsible genes of glucose metabolism are susceptible to styrene

  10. The effect of axial ion parameters on the properties of glow discharge polymer in T2B/H2 plasma

    Science.gov (United States)

    Ai, Xing; He, Xiao-Shan; Huang, Jing-Lin; He, Zhi-Bing; Du, Kai; Chen, Guo

    2018-03-01

    Glow discharge polymer (GDP) films were fabricated using plasma-enhanced chemical vapor deposition. The main purpose of this work was to explore the correlations of plasma parameters with the surface morphology and chemical structure of GDP films. The intensities of main positive ions and ion energy as functions of axial distances in T2B/H2 plasma were diagnosed using energy-resolved mass spectrometry. The surface morphology and chemical structure were characterized as functions of axial distances using a scanning electron microscope and Fourier transform infrared spectroscopy, respectively. As the axial distance increases, both the intensities of positive ions and high energy ions decreases, and dissociation weakens while polymerization enhances. This leads to the weakening of the cross-linking structure of GDP films and the formation of dome defects on films. Additionally, high energy ions could introduce a strong etching effect to form etching pits. Therefore, an axial distance of about 20 mm was found to be the optimal plasma parameter to prepare the defect-free GDP films. These results could help one to find the optimal plasma parameters for GDP film deposition.

  11. Influence of spray parameters on the microstructure and mechanical properties of gas-tunnel plasma sprayed hydroxyapatite coatings

    International Nuclear Information System (INIS)

    Morks, M.F.; Kobayashi, Akira

    2007-01-01

    For biomedical applications, hydroxyapatite (HA) coatings were deposited on 304 stainless steel substrate by using a gas tunnel type plasma spraying process. The influences of spraying distances and plasma arc currents on the microstructure, hardness and adhesion properties of HA coatings were investigated. Microstructure observation by SEM showed that HA coatings sprayed at low plasma power have a porous structure and poor hardness. HA coatings sprayed at high plasma power and short spraying distance are characterized by good adhesion and low porosity with dense structure. Hardness increased for HA coatings sprayed at shorter spraying distance and higher plasma power, mainly due to the formation of dense coatings

  12. Neural network-based preprocessing to estimate the parameters of the X-ray emission of a single-temperature thermal plasma

    Science.gov (United States)

    Ichinohe, Y.; Yamada, S.; Miyazaki, N.; Saito, S.

    2018-04-01

    We present data preprocessing based on an artificial neural network to estimate the parameters of the X-ray emission spectra of a single-temperature thermal plasma. The method finds appropriate parameters close to the global optimum. The neural network is designed to learn the parameters of the thermal plasma (temperature, abundance, normalization and redshift) of the input spectra. After training using 9000 simulated X-ray spectra, the network has grown to predict all the unknown parameters with uncertainties of about a few per cent. The performance dependence on the network structure has been studied. We applied the neural network to an actual high-resolution spectrum obtained with Hitomi. The predicted plasma parameters agree with the known best-fitting parameters of the Perseus cluster within uncertainties of ≲10 per cent. The result shows that neural networks trained by simulated data might possibly be used to extract a feature built in the data. This would reduce human-intensive preprocessing costs before detailed spectral analysis, and would help us make the best use of the large quantities of spectral data that will be available in the coming decades.

  13. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    Science.gov (United States)

    Malinina, A. A.; Malinin, A. N.

    2015-03-01

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λmax = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/ N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10-15 m3/s.

  14. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    Energy Technology Data Exchange (ETDEWEB)

    Malinina, A. A., E-mail: alexandr-malinin@rambler.ru; Malinin, A. N. [Uzhhorod National University (Ukraine)

    2015-03-15

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λ{sub max} = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10{sup −15} m{sup 3}/s.

  15. Optical characteristics and parameters of gas-discharge plasma in a mixture of mercury dibromide vapor with argon

    International Nuclear Information System (INIS)

    Malinina, A. A.; Malinin, A. N.

    2015-01-01

    Results are presented from studies of the optical characteristics and parameters of the plasma of a dielectric barrier discharge in a mixture of mercury dibromide vapor with argon—the working medium of an exciplex gas-discharge emitter. It is established that the partial pressures of mercury dibromide vapor and argon at which the average and pulsed emission intensities in the blue—green spectral region (λ max = 502 nm) reach their maximum values are 0.6 and 114.4 kPa, respectively. The electron energy distribution function, the transport characteristics, the specific power spent on the processes involving electrons, the electron density and temperature, and the rate constants for the processes of elastic and inelastic electron scattering from the molecules and atoms of the working mixture are determined by numerical simulation, and their dependences on the reduced electric field strength are analyzed. The rate constant of the process leading to the formation of exciplex mercury monobromide molecules for a reduced electric field of E/N = 20 Td, at which the maximum emission intensity in the blue—green spectral region was observed in this experiment, is found to be 8.1 × 10 −15 m 3 /s

  16. Optimization of digestion parameters for analysing the total sulphur of mine tailings by inductively coupled plasma optical emission spectrometry.

    Science.gov (United States)

    Alam, Raquibul; Shang, Julie Q; Cheng, Xiangrong

    2012-05-01

    The oxidation of sulphidic mine tailings and consequent acid generation poses challenges for the environment. Accurate and precise analysis of sulphur content is necessary for impact assessment and management of mine tailings. Here, the authors aim at developing a rapid and easy digestion procedure, which may analyse and measure the total amount of sulphur in mine tailings by using inductively coupled plasma. For evaluating effects of several variables, the researchers used a univariate (analysis of variance (ANOVA)) strategy and considered factors such as composition of the acid mixture, heating time, and refluxing device to optimize the performance. To do the experiment, the researchers have used two certified reference materials (KZK-1 and RTS-2) and samples of tailings from Musselwhite mine. ANOVA result shows that heating time is the most influencing factor on acid digestion of the reference materials whereas in case of a digestion of tailings sample, hydrochloric acid proved to be the most significant parameter. Satisfactory results between the measured and referenced values are found for all experiments. It is found that the aqua regia (1 ml HNO(3) + 3 ml HCl) digestion of 0.1 g of samples after only 40 min of heating at 95°C produced fast, safe, and accurate analytical results with a recovery of 97% for the selected reference materials.

  17. Plasma parameters of the cathode spot explosive electron emission cell obtained from the model of liquid-metal jet tearing and electrical explosion

    Science.gov (United States)

    Tsventoukh, M. M.

    2018-05-01

    A model has been developed for the explosive electron emission cell pulse of a vacuum discharge cathode spot that describes the ignition and extinction of the explosive pulse. The pulse is initiated due to hydrodynamic tearing of a liquid-metal jet which propagates from the preceding cell crater boundary and draws the ion current from the plasma produced by the preceding explosion. Once the jet neck has been resistively heated to a critical temperature (˜1 eV), the plasma starts expanding and decreasing in density, which corresponds to the extinction phase. Numerical and analytical solutions have been obtained that describe both the time behavior of the pulse plasma parameters and their average values. For the cell plasma, the momentum per transferred charge has been estimated to be some tens of g cm/(s C), which is consistent with the known measurements of ion velocity, ion erosion rate, and specific recoil force. This supports the model of the pressure-gradient-driven plasma acceleration mechanism for the explosive cathode spot cells. The ohmic electric field within the explosive current-carrying plasma has been estimated to be some tens of kV/cm, which is consistent with the known experimental data on cathode potential fall and explosive cell plasma size. This supports the model that assumes the ohmic nature of the cathode potential fall in a vacuum discharge.

  18. Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

    2012-09-15

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  19. Current state-of-the-art for the measurement of non-Maxwellian plasma parameters with the EISCAT UHF Facility

    Directory of Open Access Journals (Sweden)

    D. Hubert

    Full Text Available New results on the information that can be extracted from simulated non-Maxwellian incoherent radar spectra are presented. The cases of a pure ionosphere and of a composite ionosphere typical of a given altitude of the auroral F region are considered. In the case of a pure ionosphere of NO+ or O+ ions it has been shown that the electron temperature and the electron density can be derived from a Maxwellian analysis of radar spectra measured at aspect angles of 0° or 21° respectively; the ion temperature and ion temperature anisotropy can be derived from a non- constraining model such as the 1D Raman fitting of a complementary measurement made at an aspect angle larger than 0° for the NO+ ions, or at an aspect angle larger than 21° for the O+ ions. Moreover with such measurements at large aspect angles, the shape of the velocity ion distribution functions can simultaneously be inferred. The case of a composite ionosphere of atomic O+ and molecular NO+ ions is a difficult challenge which requires simultaneously a complementary measurement of the electron temperature to provide the ion composition and the electron density from the incoherent radar spectra at a specific aspect angle of 21°; hence, a model dependent routine is necessary to derive the ion temperatures and ion temperature anisotropies. In the case where the electron temperature is not given, a routine which depends on ion distribution models is required first: the better the ion distribution models are, the more accurately derived the plasma parameters will be. In both cases of a composite ionosphere, the 1D Raman fitting can be used to keep a check on the validity of the results provided by the ion distribution model dependent routine.

  20. Advantages of the first-derivative probe technique over the three- and four-parameter probe techniques in fusion plasmas diagnostics

    Czech Academy of Sciences Publication Activity Database

    Hasan, E.; Dimitrova, Miglena; Popov, T.; Ivanova, P.; Dejarnac, Renaud; Stöckel, Jan; Pánek, Radomír

    2018-01-01

    Roč. 13, č. 4 (2018), č. článku P04005. ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LM2015045 Institutional support: RVO:61389021 Keywords : Plasma potential * electron temperature * bi-Maxwellian EEDF * Divertor Langmuir probes * three- and four-parameter probe techniques * first-derivative probe technique Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: 2.11 Other engineering and technologies Impact factor: 1.220, year: 2016 http://iopscience.iop.org/article/10.1088/1748-0221/13/04/P04005/meta

  1. Sustained availability of trimethoprim in drinking water to achieve higher plasma sulphonamide-trimethoprim antibacterial activity in broilers.

    Science.gov (United States)

    Sumano, H; Hernandez, L; Gutierrez, L; Bernad-Bernad, M J

    2005-02-01

    (1) In order to make trimethoprim (TMP) available to broilers throughout the day, a sustained release formulation (SRF) of the drug in the form of granules was added to the water tank that supplies drinking water. (2) Broilers were initially dosed with sulphachloropiridazine-TMP (SCP-TMP 5:1) and then further medicated throughout the day, achieving in the end a dose of 30 mg/kg each of SCP and TMP (group A). Group B received a preparation with the same dose of SCP and TMP (1:1) as group A, but administered as a single dose without the SRF of TMP. Group C received the customary SCP-TMP 5:1 preparation (30 and 6 mg/kg, respectively). Water tanks were completely consumed in 3 to 4 h. (3) Broilers were bled at different times and concentration of antibacterial activity in serum determined by correlating the composite antibacterial activity of SCP and TMP with actual concentrations of these drugs by means of a microbiological agar diffusion assay. (4) Time vs serum concentrations of activity were higher in group B; the increments in the maximum serum concentration for group B over groups A and C being 39 and 67%, respectively. (5) However, the sustained concentration of activity over time, measured as the area under the cu)rve, was highest in group A. Group B had higher values for area under the curve than group C. (6) An additional dose of TMP to achieve 30 mg/kg of both SCP and TMP improves the serum concentration of this combination over the customary 5:1 proportion. The best values for sustaining antibacterial activity were obtained using a 1:1 ratio as in group A. The use of a SRF as in group A may translate into better clinical results.

  2. Estimation of Flow Channel Parameters for Flowing Gas Mixed with Air in Atmospheric-pressure Plasma Jets

    Science.gov (United States)

    Yambe, Kiyoyuki; Saito, Hidetoshi

    2017-12-01

    When the working gas of an atmospheric-pressure non-equilibrium (cold) plasma flows into free space, the diameter of the resulting flow channel changes continuously. The shape of the channel is observed through the light emitted by the working gas of the atmospheric-pressure plasma. When the plasma jet forms a conical shape, the diameter of the cylindrical shape, which approximates the conical shape, defines the diameter of the flow channel. When the working gas flows into the atmosphere from the inside of a quartz tube, the gas mixes with air. The molar ratio of the working gas and air is estimated from the corresponding volume ratio through the relationship between the diameter of the cylindrical plasma channel and the inner diameter of the quartz tube. The Reynolds number is calculated from the kinematic viscosity of the mixed gas and the molar ratio. The gas flow rates for the upper limit of laminar flow and the lower limit of turbulent flow are determined by the corresponding Reynolds numbers estimated from the molar ratio. It is confirmed that the plasma jet length and the internal plasma length associated with strong light emission increase with the increasing gas flow rate until the rate for the upper limit of laminar flow and the lower limit of turbulent flow, respectively. Thus, we are able to explain the increasing trend in the plasma lengths with the diameter of the flow channel and the molar ratio by using the cylindrical approximation.

  3. Determination by R/A of plasma cortisol levels as a parameter of adrenocortical function before and after radiotherapy of gynaecological genital carcinoma

    International Nuclear Information System (INIS)

    Freischem, C.W.

    1980-01-01

    rn 20 female patients with carcinoma of the genitals, day profiles of cortisol were established and ACTH stimulation tests carried out directly after radiotherapy and 6 months later. Plasma concentrations of cortisol were determined in a RIA as parameters of the adrenocortical function. The assumption of a change in adrenocortical activity after radiotherapy of gynaecological genital carcinoma could not be validated. Instead, there was a typical diurnal rhythm of plasma cortisol, with a peak in the early morning hours and a decrease until midnight. The same applies to the ACTH stimulation tests: In all cases, plasma cortisol levels were elevated after intravenous application of ACTH. This means that the 1976 findings of Samundzham and Butsan could not be proved. Since adrenal functions were absolutely normal in the observed cases, the adynamic clinical picture of patients after radiotherapy, which is rather infrequent, cannot be explained as being due to an impaired adrenocortical function. (orig./MG) [de

  4. Relationships between organohalogen contaminants and blood plasma clinical-chemical parameters in chicks of three raptor species from Northern Norway

    DEFF Research Database (Denmark)

    Sonne, Christian; Bustnes, Jan Ove; Herzke, Dorte

    2010-01-01

    :creatinine were significantly positively correlated to various OHCs (all: praptor chicks of Northern Scandinavia may impact blood plasma biochemistry in a way that indicates impacts on liver, kidney, bone...

  5. Analytical investigation on domain of decentered parameter for self-focusing of Hermite-cosh-Gaussian laser beam in collisional plasma

    Science.gov (United States)

    Valkunde, Amol T.; Patil, Sandip D.; Vhanmore, Bandopant D.; Urunkar, Trupti U.; Gavade, Kusum M.; Takale, Mansing V.; Fulari, Vijay J.

    2018-03-01

    In the present paper, an analytically investigated domain of decentered parameter and its effect on the self-focusing of Hermit-cosh-Gaussian (HChG) laser beams in a collisional plasma have been studied theoretically. The nonlinearity in the dielectric constant of plasma arising due to the nonuniform heating of carriers along the wavefront of the laser beam has been employed in the present investigation. The nonlinear differential equation of beam width parameter for various laser modes of HChG beam is obtained by following the standard Akhamanov's parabolic equation approach under Wentzel-Kramers-Brillouin and paraxial approximations. The analytical treatment has enabled us to define three distinct regions: self-focusing, self-trapping and defocusing, which are presented graphically.

  6. Modulation of plasma N-acylethanolamine levels and physiological parameters by dietary fatty acid composition in humans.

    Science.gov (United States)

    Jones, Peter J H; Lin, Lin; Gillingham, Leah G; Yang, Haifeng; Omar, Jaclyn M

    2014-12-01

    N-Acylethanolamines (NAEs) are endogenous lipid-signaling molecules involved in satiety and energetics; however, how diet impacts circulating NAE concentrations and their downstream metabolic actions in humans remains unknown. Objectives were to examine effects of diets enriched with high-oleic canola oil (HOCO) or HOCO blended with flaxseed oil (FXCO), compared with a Western diet (WD), on plasma NAE levels and the association with energy expenditure and substrate oxidation. Using a randomized controlled crossover design, 36 hypercholesterolemic participants consumed three isoenergetic diets for 28 days, each containing 36% energy from fat, of which 70% was HOCO, FXCO, or WD. Ultra-performance liquid chromatography-MS/MS was used to measure plasma NAE levels and indirect calorimetry to assess energy expenditure and substrate oxidation. After 28 days, compared with WD, plasma oleoylethanolamide (OEA) and alpha-linolenoyl ethanolamide (ALEA) levels were significantly increased in response to HOCO and FXCO (P = 0.002, P < 0.001), respectively. Correlation analysis demonstrated an inverse association between plasma OEA levels and percent body fat (r = -0.21, P = 0.04), and a positive association was observed between the plasma arachidonoyl ethanolamide (AEA)/OEA ratio and android:gynoid fat (r = 0.23, P = 0.02), respectively. Results suggest that plasma NAE levels are upregulated via their dietary lipid substrates and may modulate regional and total fat mass through lipid-signaling mechanisms. Copyright © 2014 by the American Society for Biochemistry and Molecular Biology, Inc.

  7. Nonequilibrium phenomena and determination of plasma parameters in the hot core of the cathode region in free-burning arc discharges

    International Nuclear Information System (INIS)

    Kuehn, Gerrit; Kock, Manfred

    2007-01-01

    We present spectroscopic measurements of plasma parameters (electron density n e , electron temperature T e , gas temperature T g , underpopulation factor b) in the hot-core region in front of the cathode of a low-current, free-burning arc discharge in argon under atmospheric pressure. The discharge is operated in the hot-core mode, creating a hot cathode region with plasma parameters similar to high-current arcs in spite of the fact that we use comparatively low currents (less than 20 A). We use continuum emission and (optically thin) line emission to determine n e and T e . We apply relaxation measurements based on a power-interruption technique to investigate deviations from local thermodynamic equilibrium (LTE). These measurements let us determine the gas temperature T g . All measurements are performed side-on with charge-coupled-device cameras as detectors, so that all measured plasma parameters are spatially resolved after an Abel inversion. This yields the first ever spatially resolved observation of the non-LTE phenomena of the hot core in the near-cathode region of free-burning arcs. The results only partly coincide with previously published predictions and measurements in the literature

  8. Limited predictive value of achieving beneficial plasma (Z)-endoxifen threshold level by CYP2D6 genotyping in tamoxifen-treated Polish women with breast cancer

    International Nuclear Information System (INIS)

    Hennig, Ewa E.; Piatkowska, Magdalena; Karczmarski, Jakub; Goryca, Krzysztof; Brewczynska, Elzbieta; Jazwiec, Radoslaw; Kluska, Anna; Omiotek, Robert; Paziewska, Agnieszka; Dadlez, Michal; Ostrowski, Jerzy

    2015-01-01

    Tamoxifen, the most frequently used drug for treating estrogen receptor-positive breast cancer, must be converted into active metabolites to exert its therapeutic efficacy, mainly through CYP2D6 enzymes. The objective of this study was to investigate the impact of CYP2D6 polymorphisms on (Z)-endoxifen-directed tamoxifen metabolism and to assess the usefulness of CYP2D6 genotyping for identifying patients who are likely to have insufficient (Z)-endoxifen concentrations to benefit from standard therapy. Blood samples from 279 Polish women with breast cancer receiving tamoxifen 20 mg daily were analyzed for CYP2D6 genotype and drug metabolite concentration. Steady-state plasma levels of tamoxifen and its 14 metabolites were measured by using the ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. In nearly 60 % of patients, including over 30 % of patients with fully functional CYP2D6, (Z)-endoxifen concentration was below the predefined threshold of therapeutic efficacy. The most frequently observed CYP2D6 genotype was EM/PM (34.8 %), among which 83.5 % of patients had a combination of wild-type and *4 alleles. Plasma concentration of five metabolites was significantly correlated with CYP2D6 genotype. For the first time, we identified an association between decreased (E/Z)-4-OH-N-desmethyl-tamoxifen-β-D-glucuronide levels (r 2 = 0.23; p < 10 −16 ) and increased CYP2D6 functional impairment. The strongest correlation was observed for (Z)-endoxifen, whose concentration was significantly lower in groups of patients carrying at least one CYP2D6 null allele, compared with EM/EM patients. The CYP2D6 genotype accounted for plasma level variability of (Z)-endoxifen by 27 % (p < 10 −16 ) and for the variability of metabolic ratio indicating (Z)-endoxifen-directed metabolism of tamoxifen by 51 % (p < 10 −43 ). The majority of breast cancer patients in Poland may not achieve a therapeutic level of (Z)-endoxifen upon receiving a standard

  9. Dependence of current density and intensity of electric field on pulsation of thermodynamic parameters of plasma in the MHD generator

    International Nuclear Information System (INIS)

    Kapron, H.

    1976-01-01

    The investigations of pulsation in the MHD generators are described. The influence of termodynamic parameters pulsation on electric parameters of the MHD generator is presented using the method of little disturbances. The results of this investigation are formulas for momentary and average values of: electrical conductivity, the Hall parameter, current density and intensity of electrical field. Analitical investigations were verified by the experiments. (author)

  10. Influence of the laser parameters on the space and time characteristics of an aluminum laser-induced plasma

    International Nuclear Information System (INIS)

    Barthelemy, O.; Margot, J.; Chaker, M.; Sabsabi, M.; Vidal, F.; Johnston, T.W.; Laville, S.; Le Drogoff, B.

    2005-01-01

    In this work, an aluminum laser plasma produced in ambient air at atmospheric pressure by laser pulses at a fluence of 10 J/cm 2 is characterized by time- and space-resolved measurements of electron density and temperature. Varying the laser pulse duration from 6 ns to 80 fs and the laser wavelength from ultraviolet to infrared only slightly influences the plasma properties. The temperature exhibits a slight decrease both at the plasma edge and close to the target surface. The electron density is found to be spatially homogeneous in the ablation plume during the first microsecond. Finally, the plasma expansion is in good agreement with the Sedov's model during the first 500 ns and it becomes subsonic, with respect to the velocity of sound in air, typically 1 μs after the plasma creation. The physical interpretation of the experimental results is also discussed to the light of a one-dimensional fluid model which provides a good qualitative agreement with measurements

  11. Correlation of III/V semiconductor etch results with physical parameters of high-density reactive plasmas excited by electron cyclotron resonance

    Science.gov (United States)

    Gerhard, FRANZ; Ralf, MEYER; Markus-Christian, AMANN

    2017-12-01

    Reactive ion etching is the interaction of reactive plasmas with surfaces. To obtain a detailed understanding of this process, significant properties of reactive composite low-pressure plasmas driven by electron cyclotron resonance (ECR) were investigated and compared with the radial uniformity of the etch rate. The determination of the electronic properties of chlorine- and hydrogen-containing plasmas enabled the understanding of the pressure-dependent behavior of the plasma density and provided better insights into the electronic parameters of reactive etch gases. From the electrical evaluation of I(V) characteristics obtained using a Langmuir probe, plasmas of different compositions were investigated. The standard method of Druyvesteyn to derive the electron energy distribution functions by the second derivative of the I(V) characteristics was replaced by a mathematical model which has been evolved to be more robust against noise, mainly, because the first derivative of the I(V) characteristics is used. Special attention was given to the power of the energy dependence in the exponent. In particular, for plasmas that are generated by ECR with EM modes, the existence of Maxwellian distribution functions is not to be taken as a self-evident fact, but the bi-Maxwellian distribution was proven for Ar- and Kr-stabilized plasmas. In addition to the electron temperature, the global uniform discharge model has been shown to be useful for calculating the neutral gas temperature. To what extent the invasive method of using a Langmuir probe could be replaced with the non-invasive optical method of emission spectroscopy, particularly actinometry, was investigated, and the resulting data exhibited the same relative behavior as the Langmuir data. The correlation with etchrate data reveals the large chemical part of the removal process—most striking when the data is compared with etching in pure argon. Although the relative amount of the radial variation of plasma density and

  12. Influence of operating parameters on surface properties of RF glow discharge oxygen plasma treated TiO{sub 2}/PET film for biomedical application

    Energy Technology Data Exchange (ETDEWEB)

    Pandiyaraj, K. Navaneetha, E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L and T by pass, Chinniyam Palayam (post), Coimbatore 641062 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Mahendiran, R. [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L and T by pass, Chinniyam Palayam (post), Coimbatore 641062 (India); Su, Pi-G [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Yassitepe, Emre; Shah, Ismat [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark (United States); Perni, Stefano [School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff (United Kingdom); Prokopovich, Polina [School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff (United Kingdom); Institute of Medical Engineering and Medical Physics, School of Engineering, Cardiff University (United Kingdom); Nadagouda, Mallikarjuna N., E-mail: Nadagouda.Mallikarjuna@epamail.epa.gov [The U.S. Environmental Protection Agency, ORD, NRMRL, WSWRD, 26W. Martin Luther King Drive, Cincinnati, OH 45268 (United States)

    2014-03-01

    In this paper, a thin transparent titania (TiO{sub 2}) film was coated on the surface of flexible poly(ethylene terephthalate) (PET) film using the sol–gel method. The surface properties of the obtained TiO{sub 2}/PET film were further improved by RF glow discharge oxygen plasma as a function of exposure time and discharge power. The changes in hydrophilicity of TiO{sub 2}/PET films were analyzed by contact angle measurements and surface energy. The influence of plasma on the surface of the TiO{sub 2}/PET films was analyzed by atomic force microscopy (AFM) as well as the change in chemical state and composition that were investigated by X-ray photo electron spectroscopy (XPS). The cytotoxicity of the TiO{sub 2}/PET films was analyzed using human osteoblast cells and the bacterial eradication behaviors of TiO{sub 2}/PET films were also evaluated against Staphylococcus bacteria. It was found that the surface roughness and incorporation of oxygen containing polar functional groups of the plasma treated TiO{sub 2}/PET films increased substantially as compared to the untreated one. Moreover the increased concentration of Ti{sup 3+} on the surface of plasma treated TiO{sub 2}/PET films was due to the transformation of chemical states (Ti{sup 4+} → Ti{sup 3+}). These morphological and chemical changes are responsible for enhanced hydrophilicity of the TiO{sub 2}/PET films. Furthermore, the plasma treated TiO{sub 2}/PET film exhibited no citotoxicity against osteoblast cells and antibacterial activity against Staphylococcus bacteria which can find application in manufacturing of biomedical devices. - Graphical abstract: Mechanism of plasma treatment on the surface of TiO{sub 2}/PET films. - Highlights: • Investigated the surface properties of TiO{sub 2}/PET films modified by O{sub 2} plasma • Studied the effect of operating parameters on surface properties of TiO{sub 2}/PET films • Mechanism of the plasma treatment on TiO{sub 2}/PET was clearly investigated.

  13. Determination of parameters of the arc plasma of electrodynamic macro-particle accelerator by the method of simulation of surface energy losses

    Energy Technology Data Exchange (ETDEWEB)

    Djuric, Z.; Mihajlov, A.A. (Inst. of Physics, Belgrade (Yugoslavia))

    1989-01-01

    In the paper we have presented the model method of calculating electrical arc parameters in the macroparticles' electrodynamic accelerator at the given rail width and the given width between them. The method is based on energy losses simulation at the arc's boundary surfaces and is a modification of the one-dimensional version of Powell and Batteh's method. It has been shown that the proposed method is adequate for operative use and that it enables the determination of both macroscopic arc parameters - acceleration, length, electroconductivity, mean temperature and density of particles etc., as well as local arc plasma parameters. The values of these parameters are determined by numerical solutions of the self-consistent system of magnetic-hydrodynamic, material and thermodynamic equations, at the arc's given mass and muzzle voltage between rails. It has also been shown that the proposed method allows the comparison of one-, two- and three-dimensional arc approximations. In the present paper we have used the method assuming that arc plasma is at most doubly ionized and produced exclusively by copper atoms. (orig.).

  14. Influence of Plasma Transferred Arc Process Parameters on Structure and Mechanical Properties of Wear Resistive NiCrBSi-WC/Co Coatings

    Directory of Open Access Journals (Sweden)

    Eitvydas GRUZDYS

    2011-07-01

    Full Text Available Self-fluxing NiCrBSi and related coatings received considerable interest due to their good wear as well as corrosion resistance at moderate and elevated temperatures. Hard tungsten carbide (WC particles can be included in NiCrBSi for further increase of the coating hardness and abrasive wear resistance. Flame spray technique is widely used for fabrication of NiCrBSi films. However, in such a case, subsequent remelting of the deposited coatings by flame, arc discharge or high power laser beam is necessary. In present study NiCrBSi-WC/Co coatings were formed using plasma transferred arc process. By adjusting plasma parameters, such as current, plasma gas flow, shielding gas flow, a number of coatings were formed on steel substrates. Structure of the coatings was investigated using X-ray diffractometry. Microstructure of cross-sectioned coatings was examined using scanning electron microscopy. Hardness of the coating was evaluated by means of the Vickers hardness tests. Wear tests were also performed on specimens to determine resistance to abrasive wear. Acquired results allowed estimating the influence of the deposition process parameters on structure and mechanical properties of the coatings.http://dx.doi.org/10.5755/j01.ms.17.2.482

  15. Investigation of the effect of laser parameters on the target, plume and plasma behavior during and after laser-solid interaction

    Science.gov (United States)

    Stancalie, A.; Ciobanu, S. S.; Sporea, D.

    2017-09-01

    A detailed theoretical and experimental analysis is performed for a wide range of laser operating conditions, typical for laser induced breakdown spectroscopy (LIBS) and laser ablation (LA) experiments on copper metallic target. The plasma parameters were experimentally estimated from the line intensities ratio which reflects the relative population of neutral excited species in the plasma. In the case of LA experiments the highest temperature observed was 8210 ± 370 K. In case of LIBS measurements, a maximum temperature of 8123 K has been determined. The experimental results are in good agreement with a stationary, hydrodynamic model. We have theoretically investigated the plasma emission based on the generalized collisional-radiative model as implemented in the ADAS interconnected set of computer codes and data collections. The ionic population density distribution over the ground and excited states into the cooper plasma is graphically displayed as output from the code. The theoretical line intensity ratios are in good agreement with experimental values for the electron density and temperature range measured in our experiments.

  16. Steady-state plasma and reactor parameters for elliptical cross section tokamaks with very large power ratings

    International Nuclear Information System (INIS)

    Usher, J.L.; Powell, J.R.

    1975-06-01

    In previous studies only circular cross section reactor plasmas were considered. The purpose of this research is to examine the effects of elliptical plasma cross sections. Several technological benefits have been determined. Maximum magnetic field strength requirements are 30 to 65 percent less than for 5000 MW (th) reactors and may be as much as 40 percent less than for circular cross section reactors of comparable size. Very large n tau values are found (10 15 to 10 17 sec/cm 3 ), which produce large burn-up fractions (15 to 60 percent). There is relatively little problem with impurity build-up. Long confinement times (60 to 500 seconds) are found. Finally, the elliptical cross section reactors exhibit a major toroidal radius reduction of as large as 30 percent over circular reactors operating at comparable power levels

  17. Effects of chromium-enriched bacillus subtilis KT260179 supplementation on chicken growth performance, plasma lipid parameters, tissue chromium levels, cecal bacterial composition and breast meat quality.

    Science.gov (United States)

    Yang, Jiajun; Qian, Kun; Zhang, Wei; Xu, Yayuan; Wu, Yijing

    2016-11-08

    Both chromium (Cr) and probiotic bacillus own the virtues of regulating animal metabolism and meat quality. Purpose of this study was to evaluate the efficiency of supplemental Cr and bacillus in the form of chromium-enriched Bacillus subtilis KT260179 (CEBS) on chicken growth performance, plasma lipid parameters, tissue chromium levels, cecal bacterial composition and breast meat quality. Six hundred of 1-day-old Chinese Huainan Partridge chickens were divided into four groups randomly: Control, inorganic Cr, Bacillus subtilis, and CEBS. The feed duration was 56 days. After 28 days of treatment, broiler feed CEBS or normal B. subtilis had higher body weights than control broiler, and after 56 days, chickens given either CEBS or B. subtilis had greater body weights than control broiler or those given inorganic Cr. Plasma total cholesterol, triglycerides, and low density lipoprotein cholesterol levels declined significantly in the CEBS group compared with the control, whereas plasma high density lipoprotein cholesterol levels increased significantly. The concentration of Cr in blood and breast muscle increased after CEBS and inorganic Cr supplementation. B. subtilis and CEBS supplementation caused a significant increase in the numbers of Lactobacillus and Bifidobacterium in the caecum, while the numbers of Escherichia coli and Salmonella decreased significantly compared to the control. Feed adding CEBS increased the lightness, redness, and yellowness of breast meat, improved the water-holding capacity, decreased the shear force and cooking loss. In all, CEBS supplementation promoted body growth, improved plasma lipid parameters, increased tissue Cr concentrations, altered cecal bacterial composition and improved breast meat quality.

  18. Structure and properties of plasma sprayed BaTiO(3) coatings: Spray parameters versus structure and photocatalytic activity

    Czech Academy of Sciences Publication Activity Database

    Ctibor, Pavel; Ageorges, H.; Štengl, Václav; Murafa, Nataliya; Píš, I.; Zahoranová, T.; Nehasil, V.; Pala, Zdeněk

    2011-01-01

    Roč. 37, č. 7 (2011), s. 2561-2567 ISSN 0272-8842 R&D Projects: GA AV ČR IAAX00430803 Institutional research plan: CEZ:AV0Z20430508; CEZ:AV0Z40320502 Keywords : Spectroscopy * Optical properties * BaTiO3 * Plasma spraying * Photocatalysis Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.751, year: 2011 http://www.sciencedirect.com/science/article/pii/S0272884211002173

  19. Blood plasma clinical-chemical parameters as biomarker endpoints for organohalogen contaminant exposure in Norwegian raptor nestlings

    DEFF Research Database (Denmark)

    Sonne, Christian; Bustnes, Jan O.; Herzke, Dorte

    2012-01-01

    Raptors are exposed to biomagnifying and toxic organohalogenated compounds (OHCs) such as organochlorines, brominated flame retardants and perfluorinated compounds. To investigate how OHC exposure may affect biochemical pathways we collected blood plasma from Norwegian northern goshawk (n=56...... it is uncertain if such changes have any health effects. The OHC concentrations were below concentrations causing reproductive toxicity in adults of other raptor species but similar to those of concern for endocrine disruption of thyroid hormones in e.g., bald eagles....

  20. Laser and Plasma Parameters for Laser Pulse Amplification by Stimulated Brillouin Backscattering in the Strong Coupling Regime

    Science.gov (United States)

    Gangolf, Thomas; Blecher, Marius; Bolanos, Simon; Lancia, Livia; Marques, Jean-Raphael; Cerchez, Mirela; Prasad, Rajendra; Aurand, Bastian; Loiseau, Pascal; Fuchs, Julien; Willi, Oswald

    2017-10-01

    In the ongoing quest for novel techniques to obtain ever higher laser powers, plasma amplification has drawn much attention, benefiting from the fact that a plasma can sustain much higher energy densities than a solid state amplifier. As a plasma process, Stimulated Brillouin Backscattering in the strong coupling regime (sc-SBS) can be used to transfer energy from one laser pulse (pump) to another (seed), by a nonlinear ion oscillation forced by the pump laser. Here, we report on experimental results on amplification by sc-SBS using the ARCTURUS Ti:Sapphire multi-beam laser system at the University of Duesseldorf, Germany. Counter-propagating in a supersonic Hydrogen gas jet target, an ultrashort seed pulse with a pulse duration between 30 and 160 fs and an energy between 1 and 12 mJ was amplified by a high-energy pump pulse (1.7 ps, 700 mJ). For some of the measurements, the gas was pre-ionized with a separate laser pulse (780 fs, 460 mJ). Preliminary analysis shows that the amplification was larger for the longer seed pulses, consistent with theoretical predictions.

  1. Comparison of the effects of an ICRF antenna with insulating side limiters with and without a Faraday screen on the edge parameters of a tokamak plasma

    International Nuclear Information System (INIS)

    Sorensen, J.; Diebold, D.A.; Majeski, R.; Hershkowitz, N.

    1993-01-01

    The PHAEDRUS-T tokamak was operated with radiofrequency power near the ion cyclotron frequency at 90 deg. C phasing between two current straps with and without a stainless steel Faraday screen covering the antenna. In both cases, the sides of the antenna were protected by insulating limiters. The plasma parameters in the scrape-off layer were measured and were shown to be essentially the same when radiofrequency power was applied from the Faraday screen covered antenna as compared with the antenna without a Faraday screen. The intensity of Fe(XVI) light dropped an order of magnitude after the screen was removed. (author). 18 refs, 3 figs

  2. Plasma parameter diagnosis using hydrogen emission spectra of a quartz-chamber 2.45 GHz ECRIS at Peking University

    Science.gov (United States)

    Wu, WenBin; Ren, HaiTao; Peng, ShiXiang; Xu, Yuan; Wen, JiaMei; Zhang, Tao; Zhang, JingFeng; Zhang, AiLin; Sun, Jiang; Guo, ZhiYu; Chen, JiaEr

    2018-04-01

    A quartz-chamber 2.45 GHz electron cyclotron resonance ion source (ECRIS) was designed for diagnostic purposes at Peking University [Patent Number: ZL 201110026605.4]. This ion source can produce a maximum 84 mA hydrogen ion beam at 50 kV with a duty factor of 10%. The root-mean-square (RMS) emittance of this beam is less than 0.12π mm mrad. In our initial work, the electron temperature and electron density inside the plasma chamber had been measured with the line intensity ratio of noble gases. Based on these results, the atomic and molecular emission spectra of hydrogen were applied to determine the dissociation degree of hydrogen and the vibrational temperature of hydrogen molecules in the ground state, respectively. Measurements were performed at gas pressures from 4×10-4 to 1×10-3 Pa and at input peak RF power ranging from 1000 to 1800 W. The dissociation degree of hydrogen in the range of 0.5%-10% and the vibrational temperature of hydrogen molecules in the ground state in the range of 3500-8500 K were obtained. The plasma processes inside this ECRIS chamber were discussed based on these results.

  3. Influence of processing parameters on the characteristics of surface layers of low temperature plasma nitrocarburized AISI 630 martensitic stainless steel

    Science.gov (United States)

    Lee, Insup

    2017-11-01

    Plasma nitrocarburizing was performed on solution-treated AISI 630 martensitic precipitation hardening stainless steel samples with a gas mixture of H2, N2, and CH4 with changing temperature, discharge voltage and amount of CH4. When nitrocarburized with increasing temperature from 380 °C to 430 °C at fixed 25% N2 and 6% CH4, the thickness of expanded martensite (α'N) layer and surface hardness increased up to 10 μm and 1323 HV0.05, respectively but the corrosion resistance decreased. Though the increase of discharge voltage from 400 V to 600 V increased α'N layer thickness and surface hardness (up to 13 μm and 1491 HV0.05, respectively), the treated samples still showed very poor corrosion behavior. Thus, to further improve the corrosion resistance, the influence of variation of the amount of CH4 in the nitrocarburizing process was investigated. Increasing the CH4 percentage aided higher corrosion resistance, although it decreased the α'N layer thickness. The most appropriate conditions for moderate α'N layer thickness, high surface hardness and better corrosion resistance than the solution-treated bare sample were established, which is plasma nitrocarburizing at 400 °C with 400 V discharge voltage and containing 25% N2 and 4% CH4.

  4. 3D numerical simulations of negative hydrogen ion extraction using realistic plasma parameters, geometry of the extraction aperture and full 3D magnetic field map

    Science.gov (United States)

    Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Franzen, P.; Fantz, U.; Minea, T.

    2014-02-01

    Decreasing the co-extracted electron current while simultaneously keeping negative ion (NI) current sufficiently high is a crucial issue on the development plasma source system for ITER Neutral Beam Injector. To support finding the best extraction conditions the 3D Particle-in-Cell Monte Carlo Collision electrostatic code ONIX (Orsay Negative Ion eXtraction) has been developed. Close collaboration with experiments and other numerical models allows performing realistic simulations with relevant input parameters: plasma properties, geometry of the extraction aperture, full 3D magnetic field map, etc. For the first time ONIX has been benchmarked with commercial positive ions tracing code KOBRA3D. A very good agreement in terms of the meniscus position and depth has been found. Simulation of NI extraction with different e/NI ratio in bulk plasma shows high relevance of the direct negative ion extraction from the surface produced NI in order to obtain extracted NI current as in the experimental results from BATMAN testbed.

  5. Effects of Hypertonic Saline Solution on Clinical Parameters, Serum Electrolytes and Plasma Volume in the Treatment of Haemorrhagic Septicaemia in Buffaloes

    Directory of Open Access Journals (Sweden)

    M. Arif Zafar*, G. Muhammad, Zafar Iqbal1 and M. Riaz2

    2010-04-01

    Full Text Available This study was conducted to determine the efficacy of hypertonic saline solution (HSS along with antibiotic (ceftiofur HCl and non-steroidal anti-inflammatory drug (ketoprofen in the treatment of haemorrhagic septicaemia in buffaloes. For this purpose, 50 buffaloes suffering from haemorrhagic septicaemia were randomly divided in two equal groups A and B. Group A served as control and was treated with ceftiofur HCl (IM and ketoprofen (IV @ 6 and 2 mg/Kg BW, respectively, for five days. Buffaloes of group B were administered with rapid intravenous infusion of hypertonic saline solution (7.5% NaCl @ 4 ml/Kg BW once in combination with ceftiofur HCl and ketoprofen. Animals were monitored for 24 hours after initiation of treatment. Clinical parameters, serum electrolytes, plasma volume and survival index were recorded at different intervals after treatment. Survival rate (80% in group B was significantly higher (P<0.05 than 48% in group A. The heart rate and respiration rate recovered more effectively in the buffaloes administered with treatment protocol B. Plasma volume was 98% which was almost normal within 24 hours after the infusion of hypertonic saline solution to the animals of group B. It was concluded from the study that hypertonic saline solution as an adjunct to antibiotic and a non-steroidal anti-inflammatory drug more efficiently improved respiration and heart rates and effectively restored plasma volume in resuscitating the buffaloes from haemorrhagic septicaemia than the conventional treatment.

  6. Experimental determination of some equilibrium parameter of Damavand tokamak by magnetic probe measurements for representing a physical model for plasma vertical movement.

    Science.gov (United States)

    Farahani, N Darestani; Davani, F Abbasi

    2015-10-01

    This investigation is about plasma modeling for the control of vertical instabilities in Damavand tokamak. This model is based on online magnetic measurement. The algebraic equation defining the vertical position in this model is based on instantaneous force-balance. Two parameters in this equation, including decay index, n, and lambda, Λ, have been considered as functions of time-varying poloidal field coil currents and plasma current. Then these functions have been used in a code generated for modeling the open loop response of plasma. The main restriction of the suitability analysis of the model is that the experiments always have to be performed in the presence of a control loop for stabilizing vertical position. As a result, open loop response of the system has been identified from closed loop experimental data by nonlinear neural network identification method. The results of comparison of physical model with identified open loop response from closed loop experiments show root mean square error percentage less than 10%. The results are satisfying that the physical model is useful as a Damavand tokamak vertical movement simulator.

  7. The effects of size and period of administration of gold nanoparticles on rheological parameters of blood plasma of rats over a wide range of shear rates: In vivo

    Directory of Open Access Journals (Sweden)

    Abdelhalim Mohamed Anwar K

    2011-10-01

    Full Text Available Abstract Background Blood viscosity appears to be independent predictor of stroke, carotid intima-media thickening, atherosclerosis and most cardiovascular diseases. In an attempt to understand the toxicity and the potential threat of GNPs therapeutic and diagnostic use, an array of rheological parameters were performed to quantify the blood plasma response to different sizes and administration periods of GNPs over a wide range of shear rates. Methods Healthy, thirty male Wistar-Kyoto rats, 8-12 weeks old (approximately 250 g body weight were divided into control group (NG: n = 10, group 1 (G1A: intraperitoneal infusion of 10 nm GNPs for 3 days, n = 5 and G1B: intraperitoneal infusion of 10 nm GNPs for 7 days, n = 5, group 2 (G2A: intraperitoneal infusion of 50 nm GNPs for 3 days, n = 5 and G2B: intraperitoneal infusion of 50 nm GNPs for 7 days, n = 5. Dose of 100 μl of GNPs was administered to the animals via intraperitoneal injection. Blood samples of nearly 1 ml were obtained from each rat. Various rheological parameters such as torque, shear stress, shear rate, viscosity, plastic velocity, yield stress, consistency index (k and flow index (n were measured in the blood plasma of rats after the intraperitoneal administration of 10 and 50 nm GNP for 3 and 7 days using Brookfield LVDV-III Programmable rheometer. Results The relationship between shear stress and shear rate for control, G1A, G1B, G2A and G2B was linearly related. The plastic viscosity and the yield stress values for G1A, G1B, G2A and G2B significantly (p Conclusions At these particular shear rates, the estimated rheological parameters are not influenced by GNPs size and shape, number of NPs, surface area and administration period of GNPs. This study demonstrates that the highly decrease in blood plasma viscosity was accompanied with the smaller 10 nm GNPs compared with the 50 nm GNPs. The decrease in blood plasma viscosity induced with 10 and 50 nm GNPs may be attributed to

  8. Princeton Plasma Physics Laboratory:

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, C.A. (ed.)

    1986-01-01

    This paper discusses progress on experiments at the Princeton Plasma Physics Laboratory. The projects and areas discussed are: Principal Parameters Achieved in Experimental Devices, Tokamak Fusion Test Reactor, Princeton Large Torus, Princeton Beta Experiment, S-1 Spheromak, Current-Drive Experiment, X-ray Laser Studies, Theoretical Division, Tokamak Modeling, Spacecraft Glow Experiment, Compact Ignition Tokamak, Engineering Department, Project Planning and Safety Office, Quality Assurance and Reliability, and Administrative Operations.

  9. Princeton Plasma Physics Laboratory:

    International Nuclear Information System (INIS)

    Phillips, C.A.

    1986-01-01

    This paper discusses progress on experiments at the Princeton Plasma Physics Laboratory. The projects and areas discussed are: Principal Parameters Achieved in Experimental Devices, Tokamak Fusion Test Reactor, Princeton Large Torus, Princeton Beta Experiment, S-1 Spheromak, Current-Drive Experiment, X-ray Laser Studies, Theoretical Division, Tokamak Modeling, Spacecraft Glow Experiment, Compact Ignition Tokamak, Engineering Department, Project Planning and Safety Office, Quality Assurance and Reliability, and Administrative Operations

  10. TMRBAR: a code to calculate plasma parameters for tandem-mirror reactors operating in the MARS mode

    International Nuclear Information System (INIS)

    Campbell, R.B.

    1983-01-01

    The purpose of this report is to document the plasma power balance model currently used by LLNL to calculate steady state operating points for tandem mirror reactors. The code developed from this model, TMRBAR, has been used to predict the performance and define supplementary heating requirements for drivers used in the Mirror Advanced Reactor Study (MARS) and for the Fusion Power Demonstration (FPD) study. The equations solved included particle and energy balance for central cell and end cell species, quasineutrality at several cardinal points in the end cell region, as well as calculations of volumes, densities and average energies based on given constraints of beta profiles and fusion power output. Alpha particle ash is treated self-consistently, but no other impurity species is treated

  11. Parallel path nebulizer: Critical parameters for use with microseparation techniques combined with inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Yanes, Enrique G.; Miller-Ihli, Nancy J.

    2005-01-01

    Four different, low flow parallel path Mira Mist CE nebulizers were evaluated and compared in support of an ongoing project related to the use of microseparation techniques interfaced to inductively coupled plasma mass spectrometry for the quantification of cobalamin species (Vitamin B12). For the characterization of the different Mira Mist CE nebulizers, the nebulizer orientation as well as the effect of methanol on analytical response was the focus of the study. The position of the gas outlet on the nebulizer which consistently provided the maximum signal was when it was rotated to the 11 o'clock position when the nebulizer is viewed end-on. With this orientation the increased signal may be explained by the fact that the cone angle of the aerosol is such that the largest percentage of the aerosol is directed to the center of the spray chamber and consequently into the plasma. To characterize the nebulizer's performance, the signal response of a multielement solution containing elements with a variety of ionization potentials was used. The selection of elements with varying ionization energies and degrees of ionization was essential for a better understanding of observed increases in signal enhancement when methanol was used. Two different phenomena contribute to signal enhancement when using methanol: the first is improved transport efficiency and the second is the 'carbon enhancement effect'. The net result was that as much as a 30-fold increase in signal was observed for As and Mg when using a make-up solution of 20% methanol at a 15 μL/min flow rate which is equivalent to a net volume of 3 μL/min of pure methanol

  12. Ellagitannins and Flavan-3-ols from Raspberry Pomace Modulate Caecal Fermentation Processes and Plasma Lipid Parameters in Rats.

    Science.gov (United States)

    Fotschki, Bartosz; Juśkiewicz, Jerzy; Sójka, Michał; Jurgoński, Adam; Zduńczyk, Zenon

    2015-12-21

    Raspberry pomace is a source of polyphenols, which nutritional and health promoting properties are not sufficiently known. The aim of this 8-weeks study was to scrutinize if raspberry extracts (REs) with different ellagitannins to flavan-3-ols ratios might favorably affect the caecal fermentation processes and blood lipid profile in rats. Forty male Wistar rats were fed with a standard diet or its modification with two types of REs (E1 and E2) characterized by different ratios of ellagitannins to flavan-3-ols (7.7 and 3.1 for E1 and E2, respectively) and added to a diet at two dosages of polyphenolic compounds (0.15 and 0.30% of a diet; L and H treatments, respectively). Irrespective of polyphenols dietary level, both REs reduced the activity of bacterial β-glucuronidase, increased production of butyric acid in the caecum and reduced triacylglycerols in blood plasma. The E1 treatment at both dosages caused more effective reduction in the concentration of ammonia and elevated acetate level in the caecal digesta than E2. On the other hand, only the E2 treatment lowered value of the atherogenic index when compared with control group. When comparing dosages of REs, a higher one was more potent to reduce the activity of bacterial β-glucosidase, β-, α-galactosidase and lowered value of the HDL profile in plasma. To conclude, REs may favorably modulate the activity of the caecal microbiota and blood lipid profile in rats; however, the intensity of these effects may be related to the dosages of dietary polyphenols and to their profile, e.g., ellagitannins to flavan-3-ols ratio.

  13. Ellagitannins and Flavan-3-ols from Raspberry Pomace Modulate Caecal Fermentation Processes and Plasma Lipid Parameters in Rats

    Directory of Open Access Journals (Sweden)

    Bartosz Fotschki

    2015-12-01

    Full Text Available Raspberry pomace is a source of polyphenols, which nutritional and health promoting properties are not sufficiently known. The aim of this 8-weeks study was to scrutinize if raspberry extracts (REs with different ellagitannins to flavan-3-ols ratios might favorably affect the caecal fermentation processes and blood lipid profile in rats. Forty male Wistar rats were fed with a standard diet or its modification with two types of REs (E1 and E2 characterized by different ratios of ellagitannins to flavan-3-ols (7.7 and 3.1 for E1 and E2, respectively and added to a diet at two dosages of polyphenolic compounds (0.15 and 0.30% of a diet; L and H treatments, respectively. Irrespective of polyphenols dietary level, both REs reduced the activity of bacterial β-glucuronidase, increased production of butyric acid in the caecum and reduced triacylglycerols in blood plasma. The E1 treatment at both dosages caused more effective reduction in the concentration of ammonia and elevated acetate level in the caecal digesta than E2. On the other hand, only the E2 treatment lowered value of the atherogenic index when compared with control group. When comparing dosages of REs, a higher one was more potent to reduce the activity of bacterial β-glucosidase, β-, α-galactosidase and lowered value of the HDL profile in plasma. To conclude, REs may favorably modulate the activity of the caecal microbiota and blood lipid profile in rats; however, the intensity of these effects may be related to the dosages of dietary polyphenols and to their profile, e.g., ellagitannins to flavan-3-ols ratio.

  14. Protective effect of ascorbic acid on netilmicin-induced lipid profile and peroxidation parameters in rabbit blood plasma.

    Science.gov (United States)

    Devbhuti, Pritesh; Sikdar, Debasis; Saha, Achintya; Sengupta, Chandana

    2011-01-01

    A drug may cause alteration in blood-lipid profile and induce lipid peroxidation phenomena on administration in the body. Antioxidant may play beneficial role to control the negative alteration in lipid profile and lipid peroxidation. In view of this context, the present in vivo study was carried out to evaluate the role of ascorbic acid as antioxidant on netilmicin-induced alteration of blood lipid profile and peroxidation parameters. Rabbits were used as experimental animals and blood was collected to estimate blood-lipid profiles, such as total cholesterol (TCh), high density lipoprotein cholesterol (HDL-Ch), low density lipoprotein cholesterol (LDL-Ch), very low density lipoprotein cholesterol (VLDL-Ch), triglycerides (Tg), phospholipids (PL), and total lipids (TL), as well as peroxidation parameters, such as malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), reduced glutathione (GSH) and nitric oxide (NO). The results revealed that netilmicin caused significant enhancement of MDA, HNE, TCh, LDL-Ch, VLDL-Ch, Tg levels and reduction in GSH, NO, HDL-Ch, PL, TL levels. On co-administration, ascorbic acid was found to be effective in reducing netilmicin-induced negative alterations of the above parameters.

  15. Relationship between plasma parameters and film microstructure in radio frequency magnetron sputter deposition of barium strontium titanate

    Science.gov (United States)

    Panda, B.; Dhar, A.; Nigam, G. D.; Bhattacharya, D.; Ray, S. K.

    1998-01-01

    Radio frequency magnetron sputtered Ba0.8Sr0.2TiO3 thin films have been deposited on silicon and Si/SiO2/SiN/Pt substrates. The analysis of plasma discharge has been carried out using the Langmuir probe technique. Both the pressure and power have been found to influence the ion density and self-bias of the target. Introduction of oxygen into the discharge effectively decreases the ion density. The structural and electrical properties have been investigated using x-ray diffraction, atomic force microscopy of deposited films and capacitance-voltage, conductance-voltage, and current density-electric field characteristics of fabricated capacitors. The growth and orientation of the films have been found to depend upon the type of substrates and deposition temperatures. The texture in the film is promoted at a pressure 0.25 Torr with a moderately high value of ion density and low ion bombardment energy. Films deposited on Si/SiO2/SiN/Pt substrate have shown higher dielectric constant (191) and lower leakage current density (2.8×10-6 A/cm2 at 100 kV/cm) compared to that on silicon.

  16. Nanosecond barrier discharge in a krypton/helium mixture containing mercury dibromide: Optical emission and plasma parameters

    Science.gov (United States)

    Malinina, A. A.; Starikovskaya, S. M.; Malinin, A. N.

    2015-01-01

    Spectral and electrical characteristics of atmospheric-pressure nanosecond barrier discharge plasma in a HgBr2/Kr/He mixture have been investigated. The discharge was initiated by positive 10-kV voltage pulses with a rise time of 4 ns and a half-amplitude duration of 28 ns. Emission from exciplex HgBr ( B 2Σ{1/2/+} - X 2Σ{1/2/+}) and KrBr ( B 2Σ{1/2/+} - X 2Σ{1/2/+}, C3/2-AΠ1/2, D1/2-AΠ1/2) molecules have been studied. From the time evolution of the B-X transition spectra of the HgBr molecule (502 nm) and KrBr molecule (207 nm), a mechanism of the formation of the exciplex molecules in the nanosecond discharge has been deduced. The distributions of the energies and rates of the processes responsible for emission from HgBr and KrBr molecules have been analyzed by numerically solving the Boltzmann equation for the electron distribution function. Experiments have confirmed the possibility of optimizing the voltage supply pulse for maximizing the efficiency of simultaneous emission in the UV and visible (green) spectral ranges from atmospheric-pressure discharge in the HgBr2/Kr/He mixture.

  17. Effect of intravenous sodium salicylate administration prior to castration on plasma cortisol and electroencephalography parameters in calves.

    Science.gov (United States)

    Bergamasco, L; Coetzee, J F; Gehring, R; Murray, L; Song, T; Mosher, R A

    2011-12-01

    Nociception is an unavoidable consequence of many routine management procedures such as castration in cattle. This study investigated electroencephalography (EEG) parameters and cortisol levels in calves receiving intravenous sodium salicylate in response to a castration model. Twelve Holstein calves were randomly assigned to the following groups: (i) castrated, untreated controls, (ii) 50 mg/kg sodium salicylate IV precastration, were blood sampled at 0, 5, 10, 20, 30, 45, 60, 90, 120, 150, 180, 240, 360, and 480 min postcastration. The EEG recording included baseline, castration, immediate recovery (0-5 min after castration), middle recovery (5-10 min after castration), and late recovery (10-20 min after castration). Samples were analyzed by competitive chemiluminescent immunoassay and fluorescence polarization immunoassay for cortisol and salicylate, respectively. EEG visual inspection and spectral analysis were performed. Statistical analyses included anova repeated measures and correlations between response variable. No treatment effect was noted between the two groups for cortisol and EEG measurements, namely an attenuation of acute cortisol response and EEG desynchronization in sodium salicylate group. Time effects were noted for EEG measurements, cortisol and salicylates levels. Significant correlations between cortisol and EEG parameters were noted. These findings have implications for designing effective analgesic regimens, and they suggest that EEG can be useful to monitor pain attributable to castration. © 2011 Blackwell Publishing Ltd.

  18. Spatial and temporal variations of small-scale plasma turbulence parameters in the equatorial electrojet: HF and VHF radar observational results

    Directory of Open Access Journals (Sweden)

    G. Manju

    2005-06-01

    Full Text Available The spatial and temporal variations of various parameters associated with plasma wave turbulence in the equatorial electrojet (EEJ at the magnetic equatorial location of Trivandrum (8.5° N, 77° E; dip 0.5° N are studied for the first time, using co-located HF (18MHz and VHF (54.95MHz coherent backscatter radar observations (daytime in the altitude region of 95-110km, mostly on magnetically quiet days. The derived turbulence parameters are the mean electron density irregularity strength (δn/n, anomalous electron collision frequency (νe* and the corrected east-west electron drift velocity (Vey. The validity of the derived parameters is confirmed using radar data at two different frequencies and comparing with in-situ measurements. The behaviour of δn/n in relation to the backscattered power during weak and strong EEJ conditions is also examined to understand the growth and evolution of turbulence in the electrojet.

  19. Spatial and temporal variations of small-scale plasma turbulence parameters in the equatorial electrojet: HF and VHF radar observational results

    Directory of Open Access Journals (Sweden)

    G. Manju

    2005-06-01

    Full Text Available The spatial and temporal variations of various parameters associated with plasma wave turbulence in the equatorial electrojet (EEJ at the magnetic equatorial location of Trivandrum (8.5° N, 77° E; dip 0.5° N are studied for the first time, using co-located HF (18MHz and VHF (54.95MHz coherent backscatter radar observations (daytime in the altitude region of 95-110km, mostly on magnetically quiet days. The derived turbulence parameters are the mean electron density irregularity strength (δn/n, anomalous electron collision frequency (νe* and the corrected east-west electron drift velocity (Vey. The validity of the derived parameters is confirmed using radar data at two different frequencies and comparing with in-situ measurements. The behaviour of δn/n in relation to the backscattered power during weak and strong EEJ conditions is also examined to understand the growth and evolution of turbulence in the electrojet.

  20. Achievement of tailored laser frequencies by fine-tuning the structural parameters of Fibonacci's in AlxGa1-xAs/GaAs superlattices

    Science.gov (United States)

    Sefir, Yamina; Aziz, Zoubir; Djelti, Redouan; Bouadjemi, Bouabdellah; Bentata, Samir

    2013-10-01

    We investigate the tunneling conduction in AlxGa1-xAs/GaAs Fibonacci superlattices. Using the transfer matrix formalism, the effective mass and envelope function approximations, we calculate the transmission coefficient of quasiperiodic multibarrier system. We examine numerically the effect of the Fibonacci's structural parameters on the electronic energy spectra of Fibonacci Superlattices (FSL). Ours results show that increasing the width of Fibonacci's wells af allows to the confinement of subminibands with a widening of minigaps, this causes a consistent and coherent fragmentation. The barrier thickness of Fibonacci bf acts on the width of subminibands by controlling the interaction force between neighboring eigenstates. Its increase gives rise to singularly extended states. The barrier height Fibonacci Vf permit to control the degree of structural disorder in these structures. The variation of these parameters permits the design of laser with modulated wavelength.

  1. Hardware and software systems for the determination of charged particle parameters in low pressure plasmas using impedance-tuned Langmuir probes

    Science.gov (United States)

    Ye, Yuancai; Marcus, R. Kenneth

    1997-12-01

    A computer-controlled, impedance-tuned Langmuir probe data acquisition system and processing software package have been designed for the diagnostic study of low pressure plasmas. The combination of impedance-tuning and a wide range of applied potentials (± 100 V) provides a versatile system, applicable to a variety of analytical plasmas without significant modification. The automated probe system can be used to produce complete and undistorted current-voltage (i-V) curves with extremely low noise over the wide potential range. Based on these hardware and software systems, it is possible to determine all of the important charged particle parameters in a plasma; electron number density ( ne), ion number density ( ni), electron temperature ( Te), electron energy distribution function (EEDF), and average electron energy (). The complete data acquisition system and evaluation software are described in detail. A LabView (National Instruments Corporation, Austin, TX) application program has been developed for the Apple Macintosh line of microcomputers to control all of the operational aspects of the Langmuir probe experiments. The description here is mainly focused on the design aspects of the acquisition system with the targets of extremely low noise and reduction of the influence of measurement noise in the calculation procedures. This is particularly important in the case of electron energy distribution functions where multiple derivatives are calculated from the obtained i-V curves. A separate C-language data processing program has been developed and is included here to allow the reader to evaluate data obtained with the described hardware, or any i-V data imported in tab separated variable format. Both of the software systems are included on a Macintosh formatted disk for their use in other laboratories desiring these capabilities.

  2. Theoretical search for optimal pump parameters for observing spontaneous radiation amplification on the λ=41.8-nm transition of Xe IX in plasma

    International Nuclear Information System (INIS)

    Ivanova, E P; Ivanov, Arkadii L

    2004-01-01

    Based on a collisional-radiative model, an atomic-kinetic calculation of the gains on the 41.8-nm transitions of Pd-like xenon was performed for the plasma produced due to the interaction of a femtosecond laser pulse with gaseous xenon. The gains g(z,τ) averaged over the spatial and temporal coordinates were compared with the known gains which had been measured experimentally in Xe 8+ . The amplification was shown to occur under the conditions of ionisation of the working ions, and the time of output radiation saturation depends on the time of Xe 8+ transformation to higher-ionised ions. Our theoretical investigation enables determining the optimal pump parameters, at which the product of the gain g by the active medium length L is about 20, which exceeds the experimental gL value. (active media)

  3. Transport code calculations concerning the plasma parameters in the scrape-off layer of poloidal limiter and the possible advantage of high Z wall materials in the cool plasma blanket approach

    International Nuclear Information System (INIS)

    Nicolai, A.; Fuchs, G.

    1978-01-01

    The plasma parameters in the scrape-off layer (SoL) of a tokamak are calculated by introducing appropriate particles and energy loss terms into the six-regime version of Duechs code. These terms take secondary electron smission from the limiter surface and a potential sheath in front of it into account. In the SoL Bohn diffusion is assumed. Limiter materials with large secondary emission coefficients (SEC)(e.g. Mo) give lower potential steps (U = 90 V) than low SEC materials (e.g. Be) which cause (U = 250 V). The flux of the sputtered liner material and the resulting radiation losses can be decreased by neutral gas influx. When the same neutral gas influx and the same additional heating are used, it is found that radiation losses due to molybdenum are lower than those due to iron, although Mo is more toxic. (Auth.)

  4. A contoured gap coaxial plasma gun with injected plasma armature

    Energy Technology Data Exchange (ETDEWEB)

    Witherspoon, F. Douglas; Case, Andrew; Messer, Sarah J.; Bomgardner, Richard II; Phillips, Michael W.; Brockington, Samuel; Elton, Raymond [HyperV Technologies Corp., Chantilly, Virginia 20151 (United States)

    2009-08-15

    A new coaxial plasma gun is described. The long term objective is to accelerate 100-200 {mu}g of plasma with density above 10{sup 17} cm{sup -3} to greater than 200 km/s with a Mach number above 10. Such high velocity dense plasma jets have a number of potential fusion applications, including plasma refueling, magnetized target fusion, injection of angular momentum into centrifugally confined mirrors, high energy density plasmas, and others. The approach uses symmetric injection of high density plasma into a coaxial electromagnetic accelerator having an annular gap geometry tailored to prevent formation of the blow-by instability. The injected plasma is generated by numerous (currently 32) radially oriented capillary discharges arranged uniformly around the circumference of the angled annular injection region of the accelerator. Magnetohydrodynamic modeling identified electrode profiles that can achieve the desired plasma jet parameters. The experimental hardware is described along with initial experimental results in which approximately 200 {mu}g has been accelerated to 100 km/s in a half-scale prototype gun. Initial observations of 64 merging injector jets in a planar cylindrical testing array are presented. Density and velocity are presently limited by available peak current and injection sources. Steps to increase both the drive current and the injected plasma mass are described for next generation experiments.

  5. A contoured gap coaxial plasma gun with injected plasma armature.

    Science.gov (United States)

    Witherspoon, F Douglas; Case, Andrew; Messer, Sarah J; Bomgardner, Richard; Phillips, Michael W; Brockington, Samuel; Elton, Raymond

    2009-08-01

    A new coaxial plasma gun is described. The long term objective is to accelerate 100-200 microg of plasma with density above 10(17) cm(-3) to greater than 200 km/s with a Mach number above 10. Such high velocity dense plasma jets have a number of potential fusion applications, including plasma refueling, magnetized target fusion, injection of angular momentum into centrifugally confined mirrors, high energy density plasmas, and others. The approach uses symmetric injection of high density plasma into a coaxial electromagnetic accelerator having an annular gap geometry tailored to prevent formation of the blow-by instability. The injected plasma is generated by numerous (currently 32) radially oriented capillary discharges arranged uniformly around the circumference of the angled annular injection region of the accelerator. Magnetohydrodynamic modeling identified electrode profiles that can achieve the desired plasma jet parameters. The experimental hardware is described along with initial experimental results in which approximately 200 microg has been accelerated to 100 km/s in a half-scale prototype gun. Initial observations of 64 merging injector jets in a planar cylindrical testing array are presented. Density and velocity are presently limited by available peak current and injection sources. Steps to increase both the drive current and the injected plasma mass are described for next generation experiments.

  6. A contoured gap coaxial plasma gun with injected plasma armature

    International Nuclear Information System (INIS)

    Witherspoon, F. Douglas; Case, Andrew; Messer, Sarah J.; Bomgardner, Richard II; Phillips, Michael W.; Brockington, Samuel; Elton, Raymond

    2009-01-01

    A new coaxial plasma gun is described. The long term objective is to accelerate 100-200 μg of plasma with density above 10 17 cm -3 to greater than 200 km/s with a Mach number above 10. Such high velocity dense plasma jets have a number of potential fusion applications, including plasma refueling, magnetized target fusion, injection of angular momentum into centrifugally confined mirrors, high energy density plasmas, and others. The approach uses symmetric injection of high density plasma into a coaxial electromagnetic accelerator having an annular gap geometry tailored to prevent formation of the blow-by instability. The injected plasma is generated by numerous (currently 32) radially oriented capillary discharges arranged uniformly around the circumference of the angled annular injection region of the accelerator. Magnetohydrodynamic modeling identified electrode profiles that can achieve the desired plasma jet parameters. The experimental hardware is described along with initial experimental results in which approximately 200 μg has been accelerated to 100 km/s in a half-scale prototype gun. Initial observations of 64 merging injector jets in a planar cylindrical testing array are presented. Density and velocity are presently limited by available peak current and injection sources. Steps to increase both the drive current and the injected plasma mass are described for next generation experiments.

  7. Spark Plasma Sintering constrained process parameters of sintered silver paste for connection in power electronic modules: Microstructure, mechanical and thermal properties

    Energy Technology Data Exchange (ETDEWEB)

    Alayli, N. [Université Paris 13, Sorbonne Paris Cité, Laboratoire des Sciences des Procédés et des Matériaux, Centre National de la Recherche Scientifique, Unité Propre de Recherche 3407, 99 avenue Jean Baptiste Clément, F-93430 Villetaneuse (France); Université de Versailles-Saint-Quentin-en-Yvelines, Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Centre National de la Recherche Scientifique/INSU, Laboratoire Atmosphères Milieux Observations Spatiales-IPSL, Quartier des Garennes, 11 Boulevard d' Alembert, F-78280 Guyancourt (France); Schoenstein, F., E-mail: frederic.schoenstein@univ-paris13.fr [Université Paris 13, Sorbonne Paris Cité, Laboratoire des Sciences des Procédés et des Matériaux, Centre National de la Recherche Scientifique, Unité Propre de Recherche 3407, 99 avenue Jean Baptiste Clément, F-93430 Villetaneuse (France); Girard, A. [Office National d' Étude et de Recherches Aérospatiales, Laboratoire d' Étude des Microstructures, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 104, 29 avenue de la Division Leclerc, F-92322 Châtillon (France); and others

    2014-11-14

    Processing parameters of Spark Plasma Sintering (SPS) technique were constrained to process nano sized silver particles bound in a paste for interconnection in power electronic devices. A novel strategy combining debinding step and consolidation processes (SPS) in order to elaborate nano-structured silver bulk material is investigated. Optimum parameters were sought for industrial power electronics packaging from the microstructural and morphological properties of the sintered material. The latter was studied by Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) to determine the density and the grain size of crystallites. Two types of samples, termed S1 (bulk) and S2 (multilayer) were elaborated and characterized. They are homogeneous with a low degree of porosity and a good adhesion to the substrate and the process parameters are compatible with industrial constraints. As the experimental results show, the mean crystallite size is between 60 nm and 790 nm with a density between 50% and 92% resulting in mechanical and thermal properties that are better than that of lead free solder. The best SPS sintering parameters, the applied pressure, the temperature and the processing time were determined as being 3 MPa, 300 °C and 1 min respectively when the desizing time of the preprocessing step was kept below 5 min at 150 °C. Using these processing parameters, acceptable for automotive packaging industry, a semi-conductor power chip was successfully connected to a metalized substrate by sintered silver with thermal and electrical properties better than those of current solders and with thermomechanical properties allowing absorption of thermoplastic stresses. - Highlights: • The sintered silver joints have nanometric structure. • The grain growth was controlled by the SPS sintering parameters. • New connection material improve thermal and electrical properties of current solders. • Interconnection's plastic strain can absorb thermo

  8. Plasma antioxidant capacity, sexual and thyroid hormones levels, sperm quantity and quality parameters in stressed male rats received nano-particle of selenium

    Directory of Open Access Journals (Sweden)

    M Rezaeian-Tabrizi

    2017-01-01

    Full Text Available Objective: To evaluate the effects of nano-particle of selenium (nSe on plasma antioxidant capacity, sexual and thyroid hormones and spermatogenesis in male rats exposed to oxidative stress.Methods: Forty rats were randomly divided into four treatments with ten replicates. Treatment groups were: C, the control group received normal saline as gavage and injection (i.p.; OS, received tert-butyl hydroperoxide (0.2 mmol/kg body weight for inducing oxidative stress; nSe, received nSe (0.3 mg/kg body weight as gavage, and OS+nSe, received tert-butyl hydroperoxide and nSe. All groups were treated for 28 d and administrations were done each 48 h.Results: Oxidative stress decreased and gavage of nSe to stressed rats increased the antioxidant capacity and activities (P0.05 between rats exposed to oxidative stress and those in the control group for sperm quantity and quality. Gavage of nSe to stressed rats had no effect (P>0.05 on the sperm parameters, except increased viability and progressive percentages.Conclusions: Nano-particle of Selenium administration in stressed rats could ameliorate the negative effects of oxidative stress on the antioxidant capacity and activities, but not on the quantity and quality parameters of sperm.

  9. Achievement report for fiscal 1981 on research under Sunshine Program. Basic research on plasma-aided coal gasification technology; 1981 nendo sushine keikaku kenkyu seika hokokusho. Sekitan no plasma gas ka gijutsu no kiso kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1982-03-01

    Researches are conducted for the development of a technology of producing useful gases such as acetylene, hydrogen, carbon monoxide, etc., from coal by the use of the high temperature and high-density energy of the plasma jet. In an experiment using a 100kW 3-port plasma-aided gasification unit, rapid quenching tests are conducted using hydrogen and helium, where the reaction furnace is changed, the specimen feed device is changed, and the plasma torch head is replaced by a high-power head. In a test of the coal specimen, it is found that rapid quenching exerts a great effect on the prevention of re-decomposition of the generated acetylene into hydrogen and carbon black and that a rise in the hydrogen partial pressure results in a great decrease in the quantity of acetylene generated. The said torch head replacement increases the rate of the coal specimen infiltrating into the plasma flame, which brings about an increase in the quantity of acetylene generated. It is found after all that the conventional acetylene yield of 34g/kWh increases to 59g/kWh in a rapid quenching test in which the specimen is dried Akabira coal and the plasma is an argon gas plasma containing 40% hydrogen. (NEDO)

  10. On the validity of setting breakpoint minimum inhibition concentrations at one quarter of the plasma concentration achieved following oral administration of oxytetracycline

    DEFF Research Database (Denmark)

    Coyne, R.; Samuelsen, O.; Bergh, Ø.

    2004-01-01

    Plasma concentrations of oxytetracycline (OTC) were established in two Atlantic salmon (Salmo salar) pre-smolts populations after they had received OTC medicated feed at a rate of 75 mg OTC/kg over 10 days. One population was experiencing an epizootic of furunculosis in a commercial freshwater farm...

  11. Serum pregnancy-associated plasma protein A levels in the first, second and third trimester of pregnancy: relation to newborn anthropometric parameters and maternal tobacco smoking.

    Science.gov (United States)

    Chełchowska, Magdalena; Gajewska, Joanna; Mazur, Joanna; Ambroszkiewicz, Jadwiga; Maciejewski, Tomasz M; Leibschang, Jerzy

    2016-12-01

    The purpose of this study was to evaluate the associations of the first, second and third trimester serum pregnancy-associated plasma protein A (PAPP-A) concentrations with neonatal anthropometric parameters. The effect of tobacco smoking during pregnancy on PAPP-A level was also studied. One hundred and fifty healthy pregnant women were divided into smoking and tobacco-abstinent groups. Serum PAPP-A level was measured with the KRYPTOR rapid random-access immunoassay analyzer. The relationship between PAPP-A and newborn related outcome as well as markers of estimated intensity of cigarette smoking was evaluated by univariate and multivariate linear regression. Pregnancy-associated plasma protein A concentration was positively correlated with birth weight in the first (β = 31.6; p < 0.001), second (β = 10.6; p < 0.05), and third (β = 4.6; p < 0.001) trimester of gestation. A significant association between PAPP-A and birth body length and head circumference in the second (β = 0.02; p < 0.05) and third trimester (β = 0.01; p < 0.01) was also found. The serum PAPP-A levels were significantly lower in the smoking than in the tobacco-abstinent group in each trimester of pregnancy ( p < 0.001). The largest impact of the number of cigarettes smoked per day on PAPP-A level was found in the second (β = -1.2; p = 0.004) and third trimester (β = -2.6; p = 0.001). Maternal serum PAPP-A levels during gestation might be significant predictors for birth weight. Increased PAPP-A concentrations in the second and third trimester appeared to also be predictive for newborn body length and head circumference. Smoking alters maternal PAPP-A levels in all trimesters, with the greatest impact related to the number of cigarettes smoked per day.

  12. Plasma centrifuge

    International Nuclear Information System (INIS)

    Ikehata, Takashi; Mase, Hiroshi

    1998-01-01

    The plasma centrifuge is one of statistical isotope separation processes which uses the centrifugal force of a J x B driven rotating plasma in a magnetic field to give rise to the mass-dependent radial transport of isotopic ions. The system has been developed as an alternative to the gas centrifuge because a much higher rotational velocity and separation factor have been achieved. In this review, the physical aspects of the plasma centrifuge followed by the recent experimental achievements are described, especially in comparison with the gas centrifuge. (author)

  13. Influences of spray parameters on the structure and corrosion resistance of stainless steel layers coated on carbon steel by plasma spray treatment

    International Nuclear Information System (INIS)

    Yeom, Kyong An; Lee, Sang Dong; Kwon, Hyuk Sang; Shur, Dong Soo; Kim, Joung Soo

    1996-01-01

    Stainless steel powders were sprayed on the grit-blasted SM45C carbon steel substrates using a plasma spray method. The influences of the spray parameters on the structure and corrosion resistance of the layers coated on the carbon steel were investigated. Corrosion behavior of the layers were analyzed by the anodic polarization tests in deaerated 0.1 M NaCl + 0.01 M NaOH solution at 80 deg C. The surface roughness and porosity were observed to decrease with decreasing the particle size. The surface hardness of the coating was always higher than that of the matrix, SM45C, implying that the higher resistance of the coating to erosion-corrosion than that of matrix, and increased as the spray power and the spray distance increase. Stainless steel coats showed more corrosion resistance than the carbon steel did, due to their passivity. The corrosion resistance of the coats, however, were inferior to that of the bulk stainless steels due to the inherent defects formed in the coats. The defects such as rough surface and pores provided the occluded sites favorable for the initiation of localized corrosion, resulting in the conclusion that finer the powder is, higher the corrosion resistance is. And the Cr oxides formation resulting in Cr depletion around the oxides reduced the corrosion resistance of the coats. (author)

  14. Effect of deposition parameter on hardness of amorphous carbon film prepared by plasma immersion ion implantation using C2H2

    International Nuclear Information System (INIS)

    Mitsuo, A.; Uchida, S.; Morikawa, K.; Kawaguchi, M.; Shiotani, K.; Suzuki, H.

    2007-01-01

    Carbon films were deposited on a cemented carbide substrate and silicon wafer at various bias voltages, acetylene (C 2 H 2 ) pressures and process times by plasma immersion ion implantation (PIII). In order to investigate the substrate temperature, the tool steel substrate was also simultaneously treated. The final substrate temperature was estimated from the hardness of the tool steel substrate. The surface and cross-sectional morphology of the deposited films were observed using a scanning electron microscope (SEM). Depth profiles of the carbon were obtained by Auger electron spectroscopy (AES). Raman spectroscopy was employed for the structural evaluation of the films. The hardness of the deposited films was measured using a nano-indenter with the maximum load of 0.5 mN. A variety of film hardnesses between 10 to 24 GPa was obtained. The hardness of the carbon films decreased with the increasing bias voltage, C 2 H 2 pressure and process time, although the intensity ratio of the disordered peak to graphitic peak in the Raman spectrum increased. It was considered that the decrease in the film hardness was caused by a stress reduction accompanied by a heating effect during the process as each PIII process parameter significantly influenced the substrate temperature

  15. Evaluation of Tumor Angiogenesis Using Dynamic Enhanced Magnetic Resonance Imaging: Comparison of Plasma Vascular Endothelial Growth Factor, Hemodynamic, and Pharmacokinetic Parameters

    International Nuclear Information System (INIS)

    Ikeda, O.; Nishimura, R.; Miyayama, H.; Yasunaga, T.; Ozaki, Y.; Tuji, A.; Yamashita, Y.

    2004-01-01

    Purpose: To assess whether tumor angiogenesis of breast cancers can be predicted on the basis of dynamic magnetic resonance imaging (MRI). Material and Methods: Seventy-one patients with 71 breast cancers underwent Gd-DTPA enhanced dynamic MRI. Two regions of interest measurements were obtained in the periphery and in the center of the breast cancers. Hemodynamic parameters obtained by dynamic MRI included peak time, contrast enhancement ratio (CE ratio), and washout ratio. The triexponential concentration curve of Gd-DTPA was fitted to a theoretical model based on compartmental analysis. The transfer constant (or permeability surface product per unit volume of compartment 'k') was obtained using this method. Tumor angiogenesis was assessed by plasma vascular endothelial growth factor (P-VEGF). Results: The P-VEGF was positive in 28 of 71 tumors (39%). The CE ratio, washout ratio, and k in the periphery in P-VEGF positive breast cancers (mean 178%, 18%, and 1.5x10 -2 (s-1)) were significantly greater (P -2 (s-1)). The peak time in the periphery in P-VEGF positive breast cancers was more marked than for P-VEGF negative breast cancers, but this difference was not significant. Conclusion: The hemodynamic and pharmacokinetic analysis of MRI provides valuable information about angiogenesis of breast cancers

  16. Assessing the kidney function parameters glomerular filtration rate and effective renal plasma flow with dynamic FDG-PET/MRI in healthy subjects.

    Science.gov (United States)

    Geist, Barbara K; Baltzer, Pascal; Fueger, Barbara; Hamboeck, Martina; Nakuz, Thomas; Papp, Laszlo; Rasul, Sazan; Sundar, Lalith Kumar Shiyam; Hacker, Marcus; Staudenherz, Anton

    2018-05-09

    A method was developed to assess the kidney parameters glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) from 2-deoxy-2-[ 18 F]fluoro-D-glucose (FDG) concentration behavior in kidneys, measured with positron emission tomography (PET) scans. Twenty-four healthy adult subjects prospectively underwent dynamic simultaneous PET/magnetic resonance imaging (MRI) examination. Time activity curves (TACs) were obtained from the dynamic PET series, with the guidance of MR information. Patlak analysis was performed to determine the GFR, and based on integrals, ERPF was calculated. Results were compared to intra-individually obtained reference values determined from venous blood samples. Total kidney GFR and ERPF as estimated by dynamic PET/MRI were highly correlated to their reference values (r = 0.88/p dynamic FDG PET/MRI scans in healthy kidneys. This has advantages for patients getting a routine scan, where additional examinations for kidney function estimation could be avoided. Further studies are required for transferring this PET/MRI method to PET/CT applications.

  17. Dependence of Parameters of Laser-Produced Au Plasmas on the Incident Laser Energy of Sub-Nanosecond and Picosecond Laser Pulses

    International Nuclear Information System (INIS)

    Woryna, E.; Badziak, J.; Makowski, J.; Parys, P.; Vankov, A.B.; Wolowski, J.; Krasa, J.; Laska, L.; Rohlena, K.

    2001-01-01

    The parameters of Au plasma as functions of laser energy for ps pulses are presented and compared with the ones for sub-ns pulses at nearly the same densities of laser energy. The experiments were performed at the IPPLM with the use of CPA (chirped pulse amplification) Nd:glass laser system. Thick Au foil targets were irradiated by normally incident focused laser beams with maximum intensities of 8x10 16 and 2x10 14 W/cm 2 for ps and sub-ns laser pulses, respectively. The characteristics of ion streams were investigated with the use of ion diagnostics methods based on the time-of flight technique. In these experiments the laser energies were changed in the range from 90 to 700 mJ and the measurements were performed at a given focus position FP = 0 and along the target normal for both the laser pulses. The charge carried by the ions, the maximum ion velocities of fast and thermal ion groups, the maximum ion current density as well as the area of photopeak in dependence on the incident laser energy for sub-ns and ps pulses were investigated and discussed. (author)

  18. Gas and plasma dynamics of RF discharge jet of low pressure in a vacuum chamber with flat electrodes and inside tube, influence of RF discharge on the steel surface parameters

    Science.gov (United States)

    Khristoliubova, V. I.; Kashapov, N. F.; Shaekhov, M. F.

    2016-06-01

    Researches results of the characteristics of the RF discharge jet of low pressure and the discharge influence on the surface modification of high speed and structural steels are introduced in the article. Gas dynamics, power and energy parameters of the RF low pressure discharge flow in the discharge chamber and the electrode gap are studied in the presence of the materials. Plasma flow rate, discharge power, the concentration of electrons, the density of RF power, the ion current density, and the energy of the ions bombarding the surface materials are considered for the definition of basic properties crucial for the process of surface modification of materials as they were put in the plasma jet. The influence of the workpiece and effect of products complex configuration on the RF discharge jet of low pressure is defined. The correlation of the input parameters of the plasma unit on the characteristics of the discharge is established.

  19. Initial operation of NSTX with plasma control

    International Nuclear Information System (INIS)

    Gates, D.; Bell, M.; Ferron, J.; Kaye, S.; Menard, J.; Mueller, D.; Neumeyer, C.; Sabbagh, S.

    2000-01-01

    First plasma, with a maximum current of 300kA, was achieved on NSTX in February 1999. These results were obtained using preprogrammed coil currents. The first controlled plasmas on NSTX were made starting in August 1999 with the full 1MA plasma current achieved in December 1999. The controlled quantities were plasma position (R, Z) and current (Ip). Variations in the plasma shape are achieved by adding preprogrammed currents to those determined by the control parameters. The control system is fully digital, with plasma position and current control, data acquisition, and power supply control all occurring in the same four-processor real time computer. The system uses the PCS (Plasma Control Software) system designed at General Atomics. Modular control algorithms, specific to NSTX, were written and incorporated into the PCS. The application algorithms do the actual control calculations, with the PCS handling data passing. The control system, including planned upgrades, will be described, along with results of the initial controlled plasma operations. Analysis of the performance of the control system will also be presented

  20. Experimental investigation of plasma relaxation using a compact coaxial magnetized plasma gun in a background plasma

    Science.gov (United States)

    Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott; University of New Mexico Collaboration; Los Alamos National Laboratory Collaboration

    2013-10-01

    A compact coaxial plasma gun is employed for experimental studies of plasma relaxation in a low density background plasma. Experiments are being conducted in the linear HelCat device at UNM. These studies will advance the knowledge of basic plasma physics in the areas of magnetic relaxation and space and astrophysical plasmas, including the evolution of active galactic jets/radio lobes within the intergalactic medium. The gun is powered by a 120pF ignitron-switched capacitor bank which is operated in a range of 5-10 kV and ~100 kA. Multiple diagnostics are employed to investigate plasma relaxation process. Magnetized Argon plasma bubbles with velocities ~1.2Cs and densities ~1020 m-3 have been achieved. Different distinct regimes of operation with qualitatively different dynamics are identified by fast CCD camera images, with the parameter determining the operation regime. Additionally, a B-dot probe array is employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify detached plasma bubble configurations. Experimental data and analysis will be presented.

  1. Plasma Etching of Tapered Features in Silicon for MEMS and Wafer Level Packaging Applications

    International Nuclear Information System (INIS)

    Ngo, H-D; Hiess, Andre; Seidemann, Volker; Studzinski, Daniel; Lange, Martin; Leib, Juergen; Shariff, Dzafir; Ashraf, Huma; Steel, Mike; Atabo, Lilian; Reast, Jon

    2006-01-01

    This paper is a brief report of plasma etching as applied to pattern transfer in silicon. It will focus more on concept overview and strategies for etching of tapered features of interest for MEMS and Wafer Level Packaging (WLP). The basis of plasma etching, the dry etching technique, is explained and plasma configurations are described elsewhere. An important feature of plasma etching is the possibility to achieve etch anisotropy. The plasma etch process is extremely sensitive to many variables such as mask material, mask openings and more important the plasma parameters

  2. Stability of ideal and resistive modes in cylindrical plasmas with resistive walls and plasma rotation

    International Nuclear Information System (INIS)

    Bondeson, A.; Xie, H.X.

    1996-01-01

    The stabilization of cylindrical plasmas by resistive walls combined with plasma rotation is analyzed. Perturbations with a single mode rational surface q=m/n in a finitely conducting plasma are treated by the resistive kink dispersion relation of Coppi. The possibilities for stabilization of ideal and resistive instabilities are explored systematically in different regions of parameter space. The study confirms that an ideal instability can be stabilized by a close-fitting wall and a rotation velocity of the order of resistive growth rate. However, the region in parameter space where such stabilization occurs is very small and appears to be difficult to exploit in experiments. The overall conclusion from the cylindrical plasma model is that resistive modes can readily be wall stabilized, whereas complete wall stabilization is hard to achieve for plasmas that are ideally unstable with the wall at infinity. 26 refs, 5 figs

  3. Achievable qualitative parameters of optical wireless links

    Czech Academy of Sciences Publication Activity Database

    Kolka, Z.; Wilfert, O.; Fišer, Ondřej

    2007-01-01

    Roč. 9, č. 8 (2007), s. 2419-2423 ISSN 1454-4164 R&D Projects: GA ČR(CZ) GA102/05/0571 Institutional research plan: CEZ:AV0Z30420517 Keywords : Free-space optical link * Transmission of atmosphere * Optical communication Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.827, year: 2007 http://inoe.inoe.ro/joam/index.php?option=magazine&op=view&idu=838&catid=16

  4. Effects of assistant anode on planar inductively coupled magnetized argon plasma in plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Tang, Deli; Chu, Paul K.

    2003-01-01

    The enhancement of planar radio frequency (RF) inductively coupled argon plasma is studied in the presence of an assistant anode and an external magnetic field at low pressure. The influence of the assistant anode and magnetic field on the efficiency of RF power absorption and plasma parameters is investigated. An external axial magnetic field is coupled into the plasma discharge region by an external electromagnetic coil outside the discharge chamber and an assistant cylindrical anode is inserted into the discharge chamber to enhance the plasma discharge. The plasma parameters and density profile are measured by an electrostatic Langmuir probe at different magnetic fields and anode voltages. The RF power absorption by the plasma can be effectively enhanced by the external magnetic field compared with the nonmagnetized discharge. The plasma density can be further increased by the application of a voltage to the assistant anode. Owing to the effective power absorption and enhanced plasma discharge by the assistant anode in a longitudinal magnetic field, the plasma density can be enhanced by more than a factor of two. Meanwhile, the nonuniformity of the plasma density is less than 10% and it can be achieved in a process chamber with a diameter of 600 mm

  5. Investigation on Ion Source Parameters

    CERN Document Server

    M. Cheikh Mhamed, S. Essabaa, C. Lau

    The EURISOL multi-mega-watt target station requires dedicated radioactive ion sources. Notably, they must be capable of operating under extremely hard radiations and with a larger fission target producing over 1014 fissions/s. The realisation of next-generation ion sources suitable for such operating conditions needs exhaustive studies and developments. In order to take up such a challenge, a review on radioactive ion sources was achieved and the investigation on ion source parameters was in particular focused on a plasma ion source through a R&D program.

  6. Plasma spheroidization of iron powders in a non-transferred DC thermal plasma jet

    International Nuclear Information System (INIS)

    Kumar, S.; Selvarajan, V.

    2008-01-01

    In this paper, the results of plasma spheroidization of iron powders using a DC non-transferred plasma spray torch are presented. The morphology of the processed powders was characterized through scanning electron microscopy (SEM) and optical microscopy (OM). The percentages of spheroidized powders were calculated by the shape factors such as the Irregularity Parameter (IP) and Roundness (RN). A maximum of 83% of spheroidization can be achieved. The spheroidization results are compared with the theoretical estimation and they are found to be in good agreement. The phase composition of the spheroidized powder was analyzed by XRD. The effect of plasma jet temperature and plasma gas flow rate on spheroidization is discussed. At low plasma gas flow rates and at high plasma jet temperatures, the percentage of spheroidization is high

  7. Plasma Periostin Levels Are Increased in Chinese Subjects with Obesity and Type 2 Diabetes and Are Positively Correlated with Glucose and Lipid Parameters.

    Science.gov (United States)

    Luo, Yuanyuan; Qu, Hua; Wang, Hang; Wei, Huili; Wu, Jing; Duan, Yang; Liu, Dan; Deng, Huacong

    2016-01-01

    The purpose of this study is to examine the relations among plasma periostin, glucose and lipid metabolism, insulin resistance and inflammation in Chinese patients with obesity (OB), and type 2 diabetes mellitus (T2DM). Plasma periostin levels in the T2DM group were significantly higher than the NGT group (P index (BMI), waist-hip ratio (WHR), fasting plasma glucose (FPG), 2 h postchallenge plasma glucose (2 h PG), glycated hemoglobin (HbA1c), triglyceride (TG), total cholesterol (TC), fasting insulin (FINS), homeostasis model assessment of insulin resistance (HOMA-IR), TNF-α, and IL-6 (P < 0.05 or 0.001) and negatively correlated with high-density lipoprotein cholesterol (HDL-C) (P < 0.001). Multiple linear regression analysis showed that TG, TNF-α, and HOMA-IR were independent related factors in influencing the levels of plasma periostin (P < 0.001). These results suggested that Chinese patients with obesity and T2DM had significantly higher plasma periostin levels. Plasma periostin levels were strongly associated with plasma TG, chronic inflammation, and insulin resistance.

  8. Luminescent N-polar (In,Ga)N/GaN quantum wells achieved by plasma-assisted molecular beam epitaxy at temperatures exceeding 700 °C

    Science.gov (United States)

    Chèze, C.; Feix, F.; Lähnemann, J.; Flissikowski, T.; Kryśko, M.; Wolny, P.; Turski, H.; Skierbiszewski, C.; Brandt, O.

    2018-01-01

    Previously, we found that N-polar (In,Ga)N/GaN quantum wells prepared on freestanding GaN substrates by plasma-assisted molecular beam epitaxy at conventional growth temperatures of about 650 °C do not exhibit any detectable luminescence even at 10 K. In the present work, we investigate (In,Ga)N/GaN quantum wells grown on Ga- and N-polar GaN substrates at a constant temperature of 730 °C . This exceptionally high temperature results in a vanishing In incorporation for the Ga-polar sample. In contrast, quantum wells with an In content of 20% and abrupt interfaces are formed on N-polar GaN. Moreover, these quantum wells exhibit a spatially uniform green luminescence band up to room temperature, but the intensity of this band is observed to strongly quench with temperature. Temperature-dependent photoluminescence transients show that this thermal quenching is related to a high density of nonradiative Shockley-Read-Hall centers with large capture coefficients for electrons and holes.

  9. Achieving scale-independent land-surface flux estimates - Application of the Multiscale Parameter Regionalization (MPR) to the Noah-MP land-surface model across the contiguous USA

    Science.gov (United States)

    Thober, S.; Mizukami, N.; Samaniego, L. E.; Attinger, S.; Clark, M. P.; Cuntz, M.

    2016-12-01

    classical averaging operators used in MPR. This allows us to identify appropriate scalings for parameters that have not been investigated in MPR so far (e.g., maximum carboxylation rate). Using MPR for Noah-MP provides a considerable improvement of the physical consistency that we expect to be achievable also in other land-surface schemes.

  10. Measurement and modeling of plasma parameters in reactive high-power impulse magnetron sputtering of Ti in Ar/O.sub.2./sub. mixtures

    Czech Academy of Sciences Publication Activity Database

    Čada, Martin; Lundin, D.; Hubička, Zdeněk

    2017-01-01

    Roč. 121, č. 17 (2017), s. 1-7, č. článku 171913. ISSN 0021-8979 R&D Projects: GA ČR(CZ) GA15-00863S EU Projects: European Commission(XE) 608800 - HIPPOCAMP Institutional support: RVO:68378271 Keywords : reactive sputtering * HiPIMS * Langmuir probe * R-IRM model * plasma density * electron temperature Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.068, year: 2016

  11. GRAVIMETRIC-DETERMINATION OF THE WATER CONCENTRATION IN WHOLE-BLOOD, PLASMA AND ERYTHROCYTES AND CORRELATIONS WITH HEMATOLOGICAL AND CLINICOCHEMICAL PARAMETERS

    NARCIS (Netherlands)

    LIJNEMA, TH; HUIZENGA, [No Value; JAGER, J; MACKOR, AJ; GIPS, CH

    1993-01-01

    We have assessed gravimetric methods for determination of intravascular water, established whole blood-, plasma- and erythrocyte water reference values in a healthy volunteer group (n = 97, 48 females) and correlated these variables with 30 simultaneous hematological, clinicochemical and body

  12. Effect of intralesional platelet-rich plasma (PRP) treatment on clinical and ultrasonographic parameters in equine naturally occurring superficial digital flexor tendinopathies - a randomized prospective controlled clinical trial.

    Science.gov (United States)

    Geburek, Florian; Gaus, Moritz; van Schie, Hans T M; Rohn, Karl; Stadler, Peter M

    2016-09-07

    Regenerative and anti-inflammatory effects on tendinopathies have been attributed to blood-derived biologicals. To date the evidence for the efficacy of autologous platelet-rich plasma (PRP) treatment of naturally occurring equine tendinopathies is limited. The purpose of this placebo-controlled clinical trial was to describe the effect of a single treatment of equine superficial digital flexor tendon (SDFT) disease with PRP on clinical and ultrasonographic parameters. Twenty horses with naturally occurring tendinopathies of forelimb SDFTs were randomly assigned to the PRP-treated group (n = 10) or control group (n = 10) after clinical and ultrasonographic examination. The SDFTs received an intralesional treatment with autologous PRP or were injected with saline, respectively (day 0). All horses participated in a standardized exercise programme and were re-examined clinically, with B-mode ultrasonography (5 times at regular intervals) and ultrasound tissue characterization (week 12 and 24 after treatment) until week 24. Long-term performance was estimated via telephone inquiry. Compared to day 0, lameness decreased significantly by week 8 after treatment with PRP and by week 12 in the control group. Ultrasonographically there was no difference in the summarized cross sectional area between the groups at any time point. Ultrasound tissue characterization showed that echo types representing disorganized matrix decreased significantly throughout the observation period in the PRP-treated group. Echo type II, representing discontinuous fascicles, not yet aligned into lines of stress was significantly higher 24 weeks after PRP treatment. Eighty percent of the PRP treated horses reached their previous or a higher level of performance after 12 months compared to 50 % in the CG. After 24 months these proportions were 60 % and 50 %, respectively. A single intralesional treatment with PRP up to 8 weeks after onset of clinical signs of tendinopathy contributes

  13. Effect of a microbial phytase on growth performance, plasma parameters and apparent ileal amino acid digestibility in Youxian Sheldrake fed a low-phosphorus corn-soybean diet

    Directory of Open Access Journals (Sweden)

    Shaoping He

    2017-10-01

    Full Text Available Objective This study investigated the effect of microbial phytase supplementation on growth performance, tibia ash, plasma parameters, apparent ileal digestibility (AID of amino acid (AA and apparent digestibility of nutrients in Youxian Sheldrakes fed with low-phosphorus (P corn-soybean diets. Methods A total of 350 Youxian Sheldrakes (7d old were randomly divided into 5 treatment groups: positive control (PC group has adequate available P diet (0.42% and 0.38%, starter and grower, negative control (NC group were deficient in available P (0.32% and 0.28%, starter and grower and NC diet was supplemented with 3 levels of microbial phytase (500, 750, and 1,000 U/kg. Results Dietary supplementation of phytase in NC diet improved the average daily gain, increased the levels of serum calcium (Ca, tibia Ca and P, AID of AA and apparent digestibility of energy and Ca in starter stage (p<0.05. There was an increased (p<0.001 in the utilization of P from 17.3% to 23.9%. Phytase supplementation (1,000 U/kg has shown that the AID of His, Thr, Val, indispensable AA, Glu, Pro, and dispensable AA was higher (p<0.05 than that of NC. Moreover, phytase supplementation improved (p<0.05 serum and tibia Ca and P, AID of AA and apparent digestibility of dry matter, crude protein, energy, P and Ca, and reduced (p<0.05 feed to gain ratio (F/G and the levels of serum alkaline phosphatase in grower stage. Likewise, an increase (p<0.001 in the utilization of P was noticed from 12.6% to 17.2%. Supplement phytase at 750 U/kg improved the AID of His, Thr, Asp, Cys, Pro, and Ser (p<0.05. Conclusion The microbial phytase supplement could improve growth performance, AID of some AA and apparent utilization of other nutrients in Youxian Sheldrakes, and reduce excreta P load to environment.

  14. Angular dependence of plasma parameters and film properties during high power impulse magnetron sputtering for deposition of Ti and TiO.sub.2./sub. layers

    Czech Academy of Sciences Publication Activity Database

    Hippler, R.; Hubička, Zdeněk; Čada, Martin; Kšírová, Petra; Wulff, H.; Helm, C.A.; Straňák, V.

    2017-01-01

    Roč. 121, č. 17 (2017), s. 1-9, č. článku 171906. ISSN 0021-8979 R&D Projects: GA ČR(CZ) GA15-00863S Institutional support: RVO:68378271 Keywords : HiPIMS * Langmuir probe * titanium dioxide * angular dependence * XRD * SEM Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.068, year: 2016

  15. Study of Plasma Detachment in a Simplified 2D Geometry using UEDGE

    International Nuclear Information System (INIS)

    Groth, M; Mahdavi, A M; Porter, G D; Rognlien, T D

    2001-01-01

    The location of the ionization front in a generic, detached plasma has been studied in a two-dimensional slab geometry by varying the core plasma density and input heating power. The ratio of the recombination to ionization current and the momentum losses in the computational domain have been used to quantify the degree of detachment. Contours of constant ratio of these parameter in the core plasma density--heating power parameter space show that at high input power higher momentum losses can be achieved even at low density. High fraction of recombination, however, require high core densities to sufficiently separate the plasma from the target plate

  16. Plasma Turbulence General Topics

    Energy Technology Data Exchange (ETDEWEB)

    Kadomtsev, B. B. [Nuclear Energy Institute, Academy of Sciences of the USSR, Moscow, USSR (Russian Federation)

    1965-06-15

    It is known that under experimental conditions plasma often shows chaotic motion. Such motion, when many degrees of freedom are excited to levels considerably above the thermal level, will be called turbulent. The properties of turbulent plasma in many respects differ from the properties of laminar plasma. It can be said that the appearance of various anomalies in plasma behaviour indicates the presence of turbulence in plasma. In order to verify directly the presence of turbulent motion in plasma we must, however, measure the fluctuation of some microscopic parameters in plasma.

  17. Evaluation of hemostasis parameters and the role of the oxidative damage to plasma proteins in the modulation of hemostasis in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy.

    Directory of Open Access Journals (Sweden)

    Paweł Woźniak

    Full Text Available Extracorporeal shock wave lithotripsy (ESWL is a commonly-used method in urology, which may modulate hemostasis and may induce lipid peroxidation in patients with nephrolithiasis. However, previous studies only examine changes occurring in patients 30-240 min after ESWL. The main aim of the present study was to determine whether oxidative stress may modulate the hemostatic activity of plasma in patients with nephrolithiasis before ESWL and the day after treatment ESWL. This will be performed by measuring selected parameters of hemostasis in these patients, both before ESWL and the following day, and assessing the level of oxidative damage to plasma proteins in these patients by measuring two biomarkers.Twelve patients with nephrolithiasis and 10 healthy participants were included. The following parameters of hemostasis were measured: the activated partial thromboplastin time (APTT, prothrombin time (PT, and thrombin time (TT of plasma, the level of fibrinogen, the level of D-dimer and blood platelet count. In addition, two selected biomarkers of oxidative stress were measured: protein carbonylation level and the number of protein thiol groups.No difference was observed between patients with nephrolithiasis before and after ESWL and healthy controls with regard to PT, TT or APTT. Fibrinogen concentration and blood platelet count were lower in the nephrolithiasis patients in the period after ESWL than before ESWL. The nephrolithiasis patients demonstrated elevated D-dimer concentration after ESWL. However, although oxidative damage was observed in the plasma proteins in the nephrolithiasis patients, this was not influenced by ESWL.Oxidative stress may induce changes of hemostasis in patients with nephrolithiasis, both before and after ESWL. In addition, changes of hemostasis parameters such as fibrinogen, blood platelet count and D-dimer level can be observed in these patients, especially after ESWL, and this may suggest that ESWL modulates

  18. Evaluation of hemostasis parameters and the role of the oxidative damage to plasma proteins in the modulation of hemostasis in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy.

    Science.gov (United States)

    Woźniak, Paweł; Kontek, Bogdan; Różański, Waldemar; Olas, Beata

    2017-01-01

    Extracorporeal shock wave lithotripsy (ESWL) is a commonly-used method in urology, which may modulate hemostasis and may induce lipid peroxidation in patients with nephrolithiasis. However, previous studies only examine changes occurring in patients 30-240 min after ESWL. The main aim of the present study was to determine whether oxidative stress may modulate the hemostatic activity of plasma in patients with nephrolithiasis before ESWL and the day after treatment ESWL. This will be performed by measuring selected parameters of hemostasis in these patients, both before ESWL and the following day, and assessing the level of oxidative damage to plasma proteins in these patients by measuring two biomarkers. Twelve patients with nephrolithiasis and 10 healthy participants were included. The following parameters of hemostasis were measured: the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) of plasma, the level of fibrinogen, the level of D-dimer and blood platelet count. In addition, two selected biomarkers of oxidative stress were measured: protein carbonylation level and the number of protein thiol groups. No difference was observed between patients with nephrolithiasis before and after ESWL and healthy controls with regard to PT, TT or APTT. Fibrinogen concentration and blood platelet count were lower in the nephrolithiasis patients in the period after ESWL than before ESWL. The nephrolithiasis patients demonstrated elevated D-dimer concentration after ESWL. However, although oxidative damage was observed in the plasma proteins in the nephrolithiasis patients, this was not influenced by ESWL. Oxidative stress may induce changes of hemostasis in patients with nephrolithiasis, both before and after ESWL. In addition, changes of hemostasis parameters such as fibrinogen, blood platelet count and D-dimer level can be observed in these patients, especially after ESWL, and this may suggest that ESWL modulates hemostasis. By

  19. Plasma heating and fuelling in the Globus-M spherical tokamak

    International Nuclear Information System (INIS)

    Gusev, V.K.; Barsukov, A.G.; Belyakov, V.A.

    2005-01-01

    The results of the last two years of plasma investigations at Globus-M are presented. Described are improvements helping to achieve high performance OH plasmas, which are used as the target for auxiliary heating and fuelling experiments. Increased energy content, high beta poloidal and good confinement are reported. Experiments on NBI plasma heating with a wide range of plasma parameters were performed. Some results are presented and analyzed. Experiments on RF plasma heating in the frequency range of fundamental ion cyclotron harmonics are described. In some experiments which were performed for the first time in spherical tokamaks, promising results were achieved. Noticeable ion heating was recorded at low launched power and a high concentration of hydrogen minority in deuterium plasmas. Simulations of RF wave absorption are briefly discussed. Described also are modification of the plasma gun and test-stand experiments. Fuelling experiments performed at Globus-M are discussed. (author)

  20. Composition of fatty acids in the maternal and umbilical cord plasma of adolescent and adult mothers: relationship with anthropometric parameters of newborn

    Directory of Open Access Journals (Sweden)

    Oliveira Olívia RC

    2012-11-01

    Full Text Available Abstract Background Considering the importance of long chain polyunsaturated fatty acids to fetal development and the lack of studies that have compared the status of fatty acids between adolescents and adults mothers, the purpose of this study was to evaluate the composition of fatty acids in maternal and umbilical cord plasma from adolescent and adults mothers. Methods Forty pregnant adolescents and forty pregnant adults were selected to assess the distribution profile of fatty acids in the maternal and umbilical cord plasma. Quantification of fatty acids in the total lipids of the sample groups was performed through the use of gas-liquid chromatography. Results The maternal and umbilical cord plasma of the adolescents showed a greater concentration of AA than did that of the adults (P  Conclusions This suggests that in situations of greater nutritional risk, as in adolescent pregnancy, n-3PUFA concentrations have a greater influence on the proper development of newborns. Moreover, variations in fatty acid concentrations in the maternal and cord plasma of adolescents and adults may indicate that pregnancy affects the LC-PUFA status of adults and adolescents in distinct ways.

  1. Boundary plasma control with the ergodic divertor

    International Nuclear Information System (INIS)

    Ghendrih, Ph.; Becoulet, M.; Beyer, P.

    1999-01-01

    Ergodic divertor experiments on Tore Supra provide evidence of significant control of plasma-wall interaction. Theoretical investigation of the laminar region (i.e. governed by parallel transport) indicates that control of the plasma state at the target plate can be achieved with plasma states similar to that observed with the axisymmetric divertor. Analysis of the temperature field with a 2-D test particle code allows one to recover the observed spatial modulation and shows that an intrinsic barrier appears to develop at the separatrix. Energy deposition peaking, analysed with a 3-D code, is strongly reduced when moderate transverse transport is considered. Possible control of upstream parameters can thus be achieved in the ergodic region, for instance a lowering of the parallel energy flux by cross field transport. (author)

  2. Boundary plasma control with the ergodic divertor

    International Nuclear Information System (INIS)

    Ghendrih, Ph.; Becoulet, M.; Beyer, P.

    2001-01-01

    Ergodic divertor experiments on Tore Supra provide evidence of significant control of plasma-wall interaction. Theoretical investigation of the laminar region (i.e. governed by parallel transport) indicates that control of the plasma state at the target plate can be achieved with plasma states similar to that observed with the axisymmetric divertor. Analysis of the temperature field with a 2-D test particle code allows one to recover the observed spatial modulation and shows that an intrinsic barrier appears to develop at the separatrix. Energy deposition peaking, analysed with a 3-D code, is strongly reduced when moderate transverse transport is considered. Possible control of upstream parameters can thus be achieved in the ergodic region, for instance a lowering of the parallel energy flux by cross field transport. (author)

  3. Plasma rotation in plasma centrifuge with an annular gap

    International Nuclear Information System (INIS)

    Lee, H.Y.; Hong, S.H.

    1982-01-01

    The steady-state rotation of plasma centrifuge is theoretically analyzed to understand the physics of rotating plasma and its feasibility for isotope separation. The centriguge system under consideration consists of an annular gap between coaxial cylindrical anode and cathod in the presence of an externally-applied axial magnetic field. A problem for coupled partial differential equations describing centrifuge fields is formulated on the basis of the magnetohydrodynamic equations. Two-dimensional solutions are found analytically in the form of Fourier-Bessel series. The current density and velocity distributions are discussed in terms of the Hartmann number and the geometrical parameter of the system. At typical conditions, rotational speeds of the plasma up to the order of 10 4 m/sec are achievable, and increase either with increasing Hartmann number, or with increasing ratio of the axial length to the inner radius of the cylinder. In view of much higher speeds of rotation which can be achieved in plasma centrifuge, it is expected that its efficiency is superior to mechanically driven gas centrifuges. (Author)

  4. Composition of fatty acids in the maternal and umbilical cord plasma of adolescent and adult mothers: relationship with anthropometric parameters of newborn

    OpenAIRE

    Oliveira, Ol?via RC; Santana, Michelle G; Santos, Fl?via S; Concei??o, Felipe D; Sardinha, F?tima LC; Veiga, Gl?ria V; Tavares do Carmo, Maria G

    2012-01-01

    Abstract Background Considering the importance of long chain polyunsaturated fatty acids to fetal development and the lack of studies that have compared the status of fatty acids between adolescents and adults mothers, the purpose of this study was to evaluate the composition of fatty acids in maternal and umbilical cord plasma from adolescent and adults mothers. Methods Forty pregnant adolescents and forty pregnant adults were selected to assess the distribution profile of fatty acids in the...

  5. Influence of Wall-Current-Compensation and Secondary-Electron-Emission on the Plasma Parameters and on the Performance of Electron Cyclotron Resonance Ion Sources

    International Nuclear Information System (INIS)

    Schachter, L.; Dobrescu, S.; Stiebing, K.E.

    2005-01-01

    Axial and radial diffusion processes determine the confinement time in an ECRIS. It has been demonstrated that a biased disk redirects the ion- and electron currents in the source in such a way that the source performance is improved. This effect is due to a partial cancellation of the compensating currents in the conductive walls of the plasma chamber.In this contribution we present an experiment, where these currents were effectively suppressed by using a metal-dielectric (MD) disk instead of the standard metallic disk in the Frankfurt 14-GHz-ECRIS. Lower values of the plasma potential and higher average charge states in the presence of the MD disk as compared to the case of the standard disk indicate that, due to the insulating properties of its dielectric layer the MD disk obviously blocks compensating wall currents better than applying bias to the metallic standard disk.A comparison with results from experiments with a MD liner in the source, covering essentially the complete radial walls of the plasma chamber, clearly demonstrates that the beneficial effect of the liner on the performance of the ECRIS is much stronger than that observed with the MD-disk. In accord with our earlier interpretation, it has to be concluded that the 'liner-effect' is not just the effect of blocking the compensating wall currents but rather has to be ascribed to the unique property of the thin MD liner as a strong secondary electron emitter under bombardment by charged particles

  6. TOPICAL REVIEW: Plasma assisted ignition and combustion

    Science.gov (United States)

    Starikovskaia, S. M.

    2006-08-01

    In recent decades particular interest in applications of nonequilibrium plasma for the problems of plasma-assisted ignition and plasma-assisted combustion has been observed. A great amount of experimental data has been accumulated during this period which provided the grounds for using low temperature plasma of nonequilibrium gas discharges for a number of applications at conditions of high speed flows and also at conditions similar to automotive engines. The paper is aimed at reviewing the data obtained and discusses their treatment. Basic possibilities of low temperature plasma to ignite gas mixtures are evaluated and historical references highlighting pioneering works in the area are presented. The first part of the review discusses plasmas applied to plasma-assisted ignition and combustion. The paper pays special attention to experimental and theoretical analysis of some plasma parameters, such as reduced electric field, electron density and energy branching for different gas discharges. Streamers, pulsed nanosecond discharges, dielectric barrier discharges, radio frequency discharges and atmospheric pressure glow discharges are considered. The second part depicts applications of discharges to reduce the ignition delay time of combustible mixtures, to ignite transonic and supersonic flows, to intensify ignition and to sustain combustion of lean mixtures. The results obtained by different authors are cited, and ways of numerical modelling are discussed. Finally, the paper draws some conclusions on the main achievements and prospects of future investigations in the field.

  7. Introduction to Plasma Physics

    Science.gov (United States)

    Gurnett, Donald A.; Bhattacharjee, Amitava

    2017-03-01

    Preface; 1. Introduction; 2. Characteristic parameters of a plasma; 3. Single particle motions; 4. Waves in a cold plasma; 5. Kinetic theory and the moment equations; 6. Magnetohydrodynamics; 7. MHD equilibria and stability; 8. Discontinuities and shock waves; 9. Electrostatic waves in a hot unmagnetized plasma; 10. Waves in a hot magnetized plasma; 11. Nonlinear effects; 12. Collisional processes; Appendix A. Symbols; Appendix B. Useful trigonometric identities; Appendix C. Vector differential operators; Appendix D. Vector calculus identities; Index.

  8. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources; Profile der Plasmaparameter und Dichte negativer Wasserstoffionen mittels Laserdetachmentmessungen in HF-angeregten Ionenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Christ-Koch, Sina

    2007-12-20

    This work shows the application of the Laserdetachment method for spatially resolved measurements of negative Hydrogen/Deuterium ion density. It was applied on a high power low pressure RF-driven ion source. The Laser detachment method is based on the measurement of electron currents on a positively biased Langmuir probe before and during/after a laser pulse. The density ratio of negative ions to electrons can be derived from the ratio of currents to the probe. The absolute density of negative ions can be obtained when the electron density is measured with the standard Langmuir probe setup. Measurements with the Langmuir probe additionally yield information about the floating and plasma potential, the electron temperature and the density of positive ions. The Laser detachment setup had to be adapted to the special conditions of the RF-driven source. In particular the existence of RF fields (1 MHz), high source potential (-20 kV), magnetic fields ({proportional_to} 7 mT) and caesium inside the source had to be considered. The density of negative ions could be identified in the range of n(H{sup -})=1.10{sup 17} 1/m{sup 3}, which is in the same order of magnitude as the electron density. Only the application of the Laser detachment method with the Langmuir probe measurements will yield spatially resolved plasma parameters and H- density profiles. The influence of diverse external parameters, such as pressure, RF-power, magnetic fields on the plasma parameters and their profiles were studied and explained. Hence, the measurements lead to a detailed understanding of the processes inside the source. (orig.)

  9. The plasma parameter log (TG/HDL-C) as an atherogenic index: correlation with lipoprotein particle size and esterification rate in apoB-lipoprotein-depleted plasma (FER(HDL))

    Czech Academy of Sciences Publication Activity Database

    Dobiášová, Milada; Frohlich, J.

    2001-01-01

    Roč. 34, č. 7 (2001), s. 583-588 ISSN 0009-9120. [Congress of the European Atherosclerosis Society /71./. Athens, 26.05.1999-29.05.1999] R&D Projects: GA ČR GV306/96/K220; GA MZd NE5465 Institutional research plan: CEZ:AV0Z5011922 Keywords : atherogenic index of plasma * HDL-cholesterol * triglycerides Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.516, year: 2001

  10. Impact of error fields on plasma identification in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Martone, R., E-mail: Raffaele.Martone@unina2.it [Ass. EURATOM/ENEA/CREATE, Seconda Università di Napoli, Via Roma 29, Aversa (CE) (Italy); Appel, L. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Chiariello, A.G.; Formisano, A.; Mattei, M. [Ass. EURATOM/ENEA/CREATE, Seconda Università di Napoli, Via Roma 29, Aversa (CE) (Italy); Pironti, A. [Ass. EURATOM/ENEA/CREATE, Università degli Studi di Napoli “Federico II”, Via Claudio 25, Napoli (Italy)

    2013-10-15

    Highlights: ► The paper deals with the effect on plasma identification of error fields generated by field coils manufacturing and assembly errors. ► EFIT++ is used to identify plasma gaps when poloidal field coils and central solenoid coils are deformed, and the gaps sensitivity with respect to such errors is analyzed. ► Some examples of reconstruction errors in the presence of deformations are reported. -- Abstract: The active control of plasma discharges in present Tokamak devices must be prompt and accurate to guarantee expected performance. As a consequence, the identification step, calculating plasma parameters from diagnostics, should provide in a very short time reliable estimates of the relevant quantities, such as plasma centroid position, plasma-wall distances at given points called gaps, and other geometrical parameters as elongation and triangularity. To achieve the desired response promptness, a number of simplifying assumptions are usually made in the identification algorithms. Among those clearly affecting the quality of the plasma parameters reconstruction, one of the most relevant is the precise knowledge of the magnetic field produced by active coils. Since uncertainties in their manufacturing and assembly process may cause misalignments between the actual and expected geometry and position of magnets, an analysis on the effect of possible wrong information about magnets on the plasma shape identification is documented in this paper.

  11. Operational conditions and characteristics of ELM-events during H-mode plasmas in the stellarator W7-AS

    International Nuclear Information System (INIS)

    Hirsch, M.; Grigull, P.; Wobig, H.; Kisslinger, J.; McCormick, K.; Anton, M.; Baldzuhn, J.; Fiedler, S.; Fuchs, Ch.; Geiger, J.; Giannone, L.; Hartfuss, H.-J.; Holzhauer, E.; Hirsch, M.; Jaenicke, R.; Kick, M.; Maassberg, H.; Wagner, F.; Weller, A.

    2000-01-01

    H-mode operation in the low-shear stellarator W7-AS is achieved for specific plasma edge topologies characterized by three 'operational windows' of the edge rotational transform. An explanation for this strong influence of the magnetic configuration could be the increase of viscous damping if rational surfaces and thus island structures occur within the relevant plasma edge layer, thereby impeding the development of an edge transport barrier. Prior to the final transition to a quiescent state, the plasma edge passes a rich phenomenology of dynamic behaviour such as dithering and ELMs. Plasma edge parameters indicate that a quiescent H-mode occurs if a certain edge pressure is achieved. (author)

  12. Effects of dietary dandelion extracts on growth performance, body composition, plasma biochemical parameters, immune responses and disease resistance of juvenile golden pompano Trachinotus ovatus.

    Science.gov (United States)

    Tan, Xiaohong; Sun, Zhenzhu; Chen, Shu; Chen, Silin; Huang, Zhong; Zhou, Chuanpeng; Zou, Cuiyun; Liu, Qingying; Ye, Huaqun; Lin, Heizhao; Ye, Chaoxia; Wang, Anli

    2017-07-01

    The present study was conducted to investigate the effects of dietary dandelion extracts (DE) supplementation on growth performance, feed utilization, body composition, plasma biochemical indices, immune responses, hepatic antioxidant abilities, and resistance to the pathogen Vibrio harveyi in Trachinotus ovatus. A basal diet supplemented with DE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g kg -1 were fed to golden pompano for 8 weeks. The study indicated that dietary supplementation with DE could significantly improve final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), feed efficiency ratio (FER), feed intake (FI), protein efficiency ratio (PER) and protein deposit rate (PDR) (P Vibrio harveyi, significant higher post-challenge survival was observed in fish fed DE supplement (P growth performance, feed utilization, body protein deposit, immune ability, hepatic and plasma antioxidative enzyme activities and improve its resistance to infection by Vibrio harveyi. Copyright © 2017. Published by Elsevier Ltd.

  13. Parameter Optimization for Enhancement of Ethanol Yield by Atmospheric Pressure DBD-Treated Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Dong Xiaoyu; Yuan Yulian; Tang Qian; Dou Shaohua; Di Lanbo; Zhang Xiuling

    2014-01-01

    In this study, Saccharomyces cerevisiae (S. cerevisiae) was exposed to dielectric barrier discharge plasma (DBD) to improve its ethanol production capacity during fermentation. Response surface methodology (RSM) was used to optimize the discharge-associated parameters of DBD for the purpose of maximizing the ethanol yield achieved by DBD-treated S. cerevisiae. According to single factor experiments, a mathematical model was established using Box-Behnken central composite experiment design, with plasma exposure time, power supply voltage, and exposed-sample volume as impact factors and ethanol yield as the response. This was followed by response surface analysis. Optimal experimental parameters for plasma discharge-induced enhancement in ethanol yield were plasma exposure time of 1 min, power voltage of 26 V, and an exposed sample volume of 9 mL. Under these conditions, the resulting yield of ethanol was 0.48 g/g, representing an increase of 33% over control. (plasma technology)

  14. Plasma heating

    International Nuclear Information System (INIS)

    Wilhelm, R.

    1989-01-01

    Successful plasma heating is essential in present fusion experiments, for the demonstration of DpT burn in future devices and finally for the fusion reactor itself. This paper discusses the common heating systems with respect to their present performance and their applicability to future fusion devices. The comparative discussion is oriented to the various function of heating, which are: - plasma heating to fusion-relevant parameters and to ignition in future machines, -non-inductive, steady-pstate current drive, - plasma profile control, -neutral gas breakdown and plasma build-up. In view of these different functions, the potential of neutral beam injection (NBI) and the various schemes of wave heating (ECRH, LH, ICRH and Alven wave heating) is analyzed in more detail. The analysis includes assessments of the present physical and technical state of these heating methods, and makes suggestions for future developments and about outstanding problems. Specific attention is given to the still critical problem of efficient current drive, especially with respect to further extrapolation towards an economically operating tokamak reactor. Remarks on issues such as reliability, maintenance and economy conclude this comparative overview on plasma heating systems. (author). 43 refs.; 13 figs.; 3 tabs

  15. Effects of Resveratrol on Ovarian Morphology, Plasma Anti-Mullerian Hormone, IGF-1 Levels, and Oxidative Stress Parameters in a Rat Model of Polycystic Ovary Syndrome.

    Science.gov (United States)

    Ergenoglu, Mete; Yildirim, Nuri; Yildirim, Alkim Gulsah Sahingoz; Yeniel, Ozgur; Erbas, Oytun; Yavasoglu, Altug; Taskiran, Dilek; Karadadas, Nedim

    2015-08-01

    To evaluate the effects of resveratrol in a rat model of polycystic ovarian syndrome (PCOS). After PCOS model was formed by subcutaneous dihydrotestosterone pellets, rats were randomly divided into 2 groups. The first group (n = 7) was treated with 1 mL/kg/d isotonic saline and the second group (n = 7) was treated with 10 mg/kg/d resveratrol. Seven rats were taken as controls without any medication. Our results showed (1) significant reduction in the number of antral follicle counts (P < .01); (2) significantly decreased plasma anti-Mullerian hormone and insulin-like growth factor 1 levels (P < .01 and P < .05, respectively); (3) significantly lower superoxide dismutase activity (P < .05); and (4) significantly increased glutathione peroxidase content (P < .01) following resveratrol treatment. Resveratrol appears to be effective in the treatment of PCOS due to its antioxidant properties. Future clinical studies with different dosages might provide useful implementations to our practice. © The Author(s) 2015.

  16. Kinetics of the processes, plasma parameters, and output characteristics of a UV emitter operating on XeI molecules and iodine molecules and atoms

    Energy Technology Data Exchange (ETDEWEB)

    Shuaibov, A. K.; Grabovaya, I. A.; Minya, A. I.; Homoki, Z. T. [Uzhgorod National University (Ukraine); Kalyuzhnaya, A. G.; Shchedrin, A. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine)

    2011-03-15

    A kinetic model of the processes occurring in the plasma of a high-power low-pressure gas-discharge lamp is presented, and the output characteristics of the lamp are described. The lamp is excited by a longitudinal glow discharge and emits the I{sub 2}(D Prime -A Prime ) 342-nm and XeI(B-X) 253-nm bands and the 206.2-nm spectral line of atomic iodine. When the emitter operates in a sealed-off mode on the p(He): p(Xe): p(I{sub 2}) = 400: 120: (100-200) Pa mixture, the fractions of the UV radiation power of iodine atoms, exciplex molecules of xenon iodide, and iodine molecules comprise 55, 10, and 35%, respectively. At the optimal partial pressure, the maximum total radiation power of the lamp reaches 37 W, the energy efficiency being about 15%.

  17. TFTR plasma feedback systems

    International Nuclear Information System (INIS)

    Efthimion, P.; Hawryluk, R.J.; Hojsak, W.; Marsala, R.J.; Mueller, D.; Rauch, W.; Tait, G.D.; Taylor, G.; Thompson, M.

    1985-01-01

    The Tokamak Fusion Test Reactor employs feedback control systems for four plasma parameters, i.e. for plasma current, for plasma major radius, for plasma vertical position, and for plasma density. The plasma current is controlled by adjusting the rate of change of current in the Ohmic Heating (OH) coil system. Plasma current is continuously sensed by a Rogowski coil and its associated electronics; the error between it and a preprogrammed reference plasma current history is operated upon by a ''proportional-plusintegral-plus-derivative'' (PID) control algorithm and combined with various feedforward terms, to generate compensating commands to the phase-controlled thyristor rectifiers which drive current through the OH coils. The plasma position is controlled by adjusting the currents in Equilibrium Field and Horizontal Field coil systems, which respectively determine the vertical and radial external magnetic fields producing J X B forces on the plasma current. The plasma major radius position and vertical position, sensed by ''B /sub theta/ '' and ''B /sub rho/ '' magnetic flux pickup coils with their associated electronics, are controlled toward preprogrammed reference histories by allowing PID and feedforward control algorithms to generate commands to the EF and HF coil power supplies. Plasma density is controlled by adjusting the amount of gas injected into the vacuum vessel. Time-varying gains are used to combine lineaveraged plasma density measurements from a microwave interferometer plasma diagnostic system with vacuum vessel pressure measurements from ion gauges, with various other measurements, and with preprogrammed reference histories, to determine commands to piezoelectric gas injection valves

  18. Princeton University, Plasma Physics Laboratory annual report, October 1, 1988--September 30, 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-12-31

    This report contains discussions on the following topics: principal parameters achieved in experimental devices (FY89); tokamak fusion test reactor; compact ignition tokamak; princeton beta experiment- modification; current drive experiment; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for (FY89); graduate education: plasma physics; graduate education: plasma science and technology; and Princeton Plasmas Physics Laboratory Reports (FY89).

  19. Princeton Plasma Physics Laboratory. Annual report, October 1, 1989--September 30, 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

  20. Princeton University, Plasma Physics Laboratory annual report, October 1, 1988--September 30, 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    This report contains discussions on the following topics: principal parameters achieved in experimental devices (FY89); tokamak fusion test reactor; compact ignition tokamak; princeton beta experiment- modification; current drive experiment; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for (FY89); graduate education: plasma physics; graduate education: plasma science and technology; and Princeton Plasmas Physics Laboratory Reports (FY89).

  1. Princeton University, Plasma Physics Laboratory annual report, October 1, 1988--September 30, 1989

    International Nuclear Information System (INIS)

    1989-01-01

    This report contains discussions on the following topics: principal parameters achieved in experimental devices (FY89); tokamak fusion test reactor; compact ignition tokamak; princeton beta experiment- modification; current drive experiment; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for (FY89); graduate education: plasma physics; graduate education: plasma science and technology; and Princeton Plasmas Physics Laboratory Reports (FY89)

  2. Influence of an External DC Electric Current on Plasma Cleaning Rate: an Application on the Enlarged Plasma-Surface Theory

    International Nuclear Information System (INIS)

    Xaplanteris, Constantine L.; Filippaki, Eleni D.

    2013-01-01

    During the last decades many researchers have been occupied with other plasma applications apart from the big challenge which the thermonuclear fusion poses. Many experiments have been carried out on the plasma behavior in contact with a solid surface; when the surface material consists of chemical compounds (e.g. oxides of metals), then the plasma chemistry takes place. The present paper contains the final experimental and theoretical work of Plasma Laboratory at “Demokritos , which consists of an elaboration of plasma sheath parameters adapted to experimental conditions, a suitable choice of plasma gases (either H 2 or N 2 ), and an electric potential current enforcement on objects. Additionally, a brief theory is given to explain the results, with a short reference to both boundary phenomena in thermonuclear reactors and low pressure plasma of glow discharges, so as to reveal the similarities and differences of these two cases. An extensive examination of the treated objects by X-ray diffraction method (XRD) gives results in agreement with the theoretical predictions. Using this improvement on plasma restoration system, (a combination of electric current on metallic object into suitable plasma), it is shown that better results can be achieved on the cleaning and conservation of archaeological objects. (plasma technology)

  3. Dust in flowing magnetized plasma

    International Nuclear Information System (INIS)

    Pandey, Birendra P.; Samarian, Alex A.; Vladimirov, Sergey V.

    2009-01-01

    Plasma flows occur in almost every laboratory device and interactions of flowing plasmas with near-wall impurities and/or dust significantly affects the efficiency and lifetime of such devices. The charged dust inside the magnetized flowing plasma moves primarily under the influence of the plasma drag and electric forces. Here, the charge on the dust, plasma potential, and plasma density are calculated self-consistently. The electrons are assumed non-Boltzmannian and the effect of electron magnetization and electron-atom collisions on the dust charge is calculated in a self-consistent fashion. For various plasma magnetization parameters viz. the ratio of the electron and ion cyclotron frequencies to their respective collision frequencies, plasma-atom and ionization frequencies, the evolution of the plasma potential and density in the flow region is investigated. The variation of the dust charge profile is shown to be a sensitive function of plasma parameters. (author)

  4. The Influence of Spray Parameters on the Characteristics of Hydroxyapatite In-Flight Particles, Splats and Coatings by Micro-plasma Spraying

    Science.gov (United States)

    Liu, Xiao-mei; He, Ding-yong; Wang, Yi-ming; Zhou, Zheng; Wang, Guo-hong; Tan, Zhen; Wang, Zeng-jie

    2018-04-01

    Hydroxyapatite (HA) is one of the most important bioceramic materials used in medical implants. The structure of HA coatings is closely related to their manufacturing process. In the present study, HA coatings were deposited on Ti-6Al-4V substrate by micro-plasma spraying. Results show that three distinct HA coatings could be obtained by changing the spraying power from 0.5 to 1.0 kW and spraying stand-off distance from 60 to 110 mm: (1) high crystallinity (93.3%) coatings with porous structure, (2) high crystallinity coatings (86%) with columnar structure, (3) higher amorphous calcium phosphate (ACP, 50%) coatings with dense structure. The in-flight particles melting state and splat topography was analyzed to better understand the formation mechanism of three distinct HA coatings. Results show that HA coatings sprayed at low spraying power and short stand-off distance exhibit high crystallinity and porosity is attributed to the presence of partially melted particles. High crystallinity HA coatings with (002) crystallographic texture could be deposited due to the complete melting of the in-flight particles and low cooling rate of the disk shape splats under higher spraying power and shorter SOD. However, splashed shape splats with relative high cooling can be provided by increasing SOD, which leads to the formation of ACP.

  5. The use of cold plasma generators in medicine

    Directory of Open Access Journals (Sweden)

    Kolomiiets R.O.

    2017-04-01

    Full Text Available Cold plasma treatment of wounds is a modern area of therapeutic medicine. We describe the physical mechanisms of cold plasma, the principles of therapeutic effects and design of two common types of cold plasma generators for medical use. This work aims at disclosing the basic principles of construction of cold atmospheric plasma generators in medicine and prospects for their further improvement. The purpose of this work is to improve the existing cold atmospheric plasma generators for use in medical applications. Novelty of this work consists in the application of new principles of construction of cold atmospheric plasmas medical apparatus, namely the combination of the gas discharge chamber, electrodes complex shape forming device and plasma flow in a single package. This helps to achieve a significant reduction in the size of the device, and a discharge chamber design change increases the therapeutic effect. The design of cold atmospheric plasma generator type «pin-to-hole», which is able to control parameters using the plasma current (modulation fluctuations in the primary winding and mechanically (using optional rotary electrode. It is also possible to combine some similar generators in the set, which will increase the surface area of the plasma treatment. We consider the basic principles of generating low atmospheric plasma flow, especially the formation of the plasma jet, changing its shape and modulation stream. The features of cold plasma generator design and information about prospects for further application, and opportunities for further improvement are revealed. The recommendations for further use of cold atmospheric plasma generators in medicine are formulated.

  6. Iron, Hematological Parameters and Blood Plasma Lipid Profile in Vitamin D Supplemented and Non-Supplemented Young Soccer Players Subjected to High-Intensity Interval Training.

    Science.gov (United States)

    Jastrzebska, Maria; Kaczmarczyk, Mariusz; Suárez, Arturo Diaz; Sánchez, Guillermo Felipe López; Jastrzebska, Joanna; Radziminski, Lukasz; Jastrzebski, Zbigniew

    2017-01-01

    Vitamin D deficiency has been associated with increased risk for cardiovascular disease and anemia. Vitamin D-related changes in lipid profile have been studied extensively but the relationship between vitamin D and lipid metabolism is not completely understood. As both vitamin D and intermittent training may potentially affect iron and lipid metabolism, the aim of the study was to evaluate whether a daily supplementation of vitamin D can modulate the response of hematological and lipid parameters to high-intensity interval training (HIIT) in soccer players. Thirty-six young elite junior soccer players were included in the placebo-controlled, double-blind study. Participants were non-randomly allocated into either a supplemented group (SG, n=20, HIIT and 5,000 IU of vitamin D daily) or placebo group (PG, n=16, HIIT and sunflower oil). Hematological parameters were ascertained before and after the 8-wk training. The change score (post- and pre-training difference) was calculated for each individual and the mean change score (MCS) was compared between SG and PG using the t test and analysis of covariance. There were no differences between SG and PG at baseline. The red and white cell count, hemoglobin, hematocrit, MCHC, ferritin, and HDL-cholesterol changed significantly over the 8-wk HIIT. However, no significant differences in MCS were observed between SG and PG for any variable. A daily vitamin D supplement did not have any impact on alteration in hematological or lipid parameters in young soccer players in the course of high-intensity interval training.

  7. Chapter 8: Plasma operation and control [Progress in the ITER Physics Basis (PIPB)

    International Nuclear Information System (INIS)

    Gribov, Y.; Humphreys, D.; Kajiwara, K.; Lazarus, E.A.; Lister, J.B.; Ozeki, T.; Portone, A.; Shimada, M.; Sips, A.C.C.; Wesley, J.C.

    2007-01-01

    The ITER plasma control system has the same functional scope as the control systems in present tokamaks. These are plasma operation scenario sequencing, plasma basic control (magnetic and kinetic), plasma advanced control (control of RWMs, NTMs, ELMs, error fields, etc) and plasma fast shutdown. This chapter considers only plasma initiation and plasma basic control. This chapter describes the progress achieved in these areas in the tokamak experiments since the ITER Physics Basis (1999 Nucl. Fusion 39 2577) was written and the results of assessment of ITER to provide the plasma initiation and basic control. This assessment was done for the present ITER design (15 MA machine) at a more detailed level than it was done for the ITER design 1998 (21 MA machine) described in the ITER Physics Basis (1999 Nucl. Fusion 39 2577). The experiments on plasma initiation performed in DIII-D and JT-60U, as well as the theoretical studies performed for ITER, have demonstrated that, within specified assumptions on the plasma confinement and the impurity influx, ITER can produce plasma initiation in a low toroidal electric field (0.3 V m -1 ), if it is assisted by about 2 MW of ECRF heating. The plasma basic control includes control of the plasma current, position and shape-the plasma magnetic control, as well as control of other plasma global parameters or their profiles-the plasma performance control. The magnetic control is based on more reliable and simpler models of the control objects than those available at present for the plasma kinetic control. Moreover the real time diagnostics used for the magnetic control in many cases are more precise than those used for the kinetic control. Because of these reasons, the plasma magnetic control was developed for modern tokamaks and assessed for ITER better than the kinetic control. However, significant progress has been achieved in the plasma performance control during the last few years. Although the physics basis of plasma operation

  8. Burning plasmas

    International Nuclear Information System (INIS)

    Furth, H.P.; Goldston, R.J.; Zweben, S.J.

    1990-10-01

    The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R ampersand D areas that need to be addressed on the way to a fusion power demonstration

  9. Deposition of SiOx thin films on Y-TZP by reactive magnetron sputtering: influence of plasma parameters on the adhesion properties between Y-TZP and resin cement for application in dental prosthesis

    Directory of Open Access Journals (Sweden)

    José Renato Calvacanti de Queiroz

    2011-01-01

    Full Text Available In this paper SiOx thin films were deposited on Y-TZP ceramics by reactive magnetron sputtering technique in order to improve the adhesion properties between Y-TZP and resin cement for applications in dental prosthesis. For fixed cathode voltage, target current, working pressure and target-to-substrate distance, SiOx thin films were deposited at different oxygen concentrations in the Ar+O2 plasma forming gas. After deposition processes, SiOx thin films were characterized by profilometry, energy dispersive spectroscopy (EDS, optical microscopy and scanning electron microscopy (SEM. Adhesion properties between Y-TZP and resin cement were evaluated by shear testing. Results indicate that films deposited at 20%O2 increased the bond strength to (32.8 ± 5.4 MPa. This value has not been achieved by traditional methods.

  10. Effects of 1alpha-hydroxycholecalciferol on growth performance, parameters of tibia and plasma, meat quality, and type IIb sodium phosphate cotransporter gene expression of one- to twenty-one-day-old broilers.

    Science.gov (United States)

    Han, J C; Yang, X D; Zhang, T; Li, H; Li, W L; Zhang, Z Y; Yao, J H

    2009-02-01

    This experiment was conducted to investigate the effects of 1alpha-hydroxycholecalciferol (1alpha-OH D3) on the growth performance, tibia and plasma parameters, nutrient utilization, meat quality of the breast and thigh, and type IIb sodium phosphate cotranspoter gene expression of broilers. A total of 96 males of 1-d-old Arbor Acres broilers were randomly assigned to 8 cages of 12 birds each. Two dietary treatments were applied to 4 cages each. Diet 1 was prepared as the basal diet (nonphytate phosphorus, 0.21%), whereas diet 2 was the basal diet supplemented with 5 microg/kg of 1alpha-OH D3. Results showed that supplementation of the basal diet with 1alpha-OH D3 increased growth performance, tibia ash and strength, plasma inorganic phosphate concentration, utilization of total phosphorus and nonphytate phosphorus, lightness and yellowness of the breast and thigh meat, and intestinal type IIb sodium phosphate cotranspoter mRNA expression, whereas it decreased the shear force and water-holding capacity of the thigh meat. These data suggest that the addition of 1alpha-OH D3 might improve growth performance, tibia development, and meat quality in 1- to 21-d-old broilers by increasing the absorption and retention of phosphorus.

  11. Plasma processing: Technologies and applications

    International Nuclear Information System (INIS)

    Naddaf, M.; Saloum, S.

    2005-01-01

    This study aims to present the fundamentals of physics of plasmas, methods of generation, diagnostics, and applications for processing of materials. The first chapter defines plasma in general as well as its main parameters, the most important differential equations in plasma physics, and classifies the types of plasmas. the various methods and techniques to create and sustain plasma are presented in the second chapter. Chapter 3 focuses on plasma diagnostic methods and tools. While chapter 4 deals with applications of plasma processing such as; surface modification of materials, plasma ashing and etching, plasma cutting, and the environmental applications of plasma. Plasma polymerization and its various applications have been presented in more details in the last chapter. (Author)

  12. Space plasmas 2

    International Nuclear Information System (INIS)

    Frankel, N.E.; Hines, K.C.; Kowalenko, V.

    1981-01-01

    The longitudinal dielectric response of an ultra-degenerate relativistic plasma composed of electrons and positrons is considered. The relativistic Hartree self-consistent field method is used to investigate the dispersion relations and damping parameters of such a plasma in the presence of a magnetic field. These properties must be studied in the various regimes appropriate for a relativistic plasma as detailed by Tsytovich and Jancovici

  13. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein

    2017-01-01

    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  14. Achievement report for fiscal 1981 on Sunshine Program research and development of photovoltaic power systems. Research and development of amorphous solar cells (Research and development of high-quality amorphous silicon film formation technologies using plasma separation); 1981 nendo taiyoko hatsuden system no kenkyu kaihatsu seika hokokusho. Amorphous taiyo denchi no kenkyu kaihatsu (plasma bunri ni yoru kohinshitsu amorphous silicon maku seimaku gijutsu no kenkyu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1982-03-01

    When discharge plasma is applied for film formation, ions affect the quality of the resultant film. In the case of plasma CVD (chemical vapor deposition) method, there exists correspondence between the radicals ratio SiH/H and solar cell conversion efficiency, and plasma measurement may be used for the control of film formation conditions. The state of distribution of radicals in discharge plasma is dependent on the type of radicals, and there is an optimum substrate position. Photoelectric characteristics are improved when a grid electrode is used for plasma separation. The surface of a transparent conductive film (ITO: indium-tin oxide) to be the substrate for film formation needs to be flat, and part of its Si is oxidized into SiO{sub 2} by generated oxygen. An ITO film coated by chemically stable SnO{sub 2} is useful. When the ion plating method is employed, film formation conditions are first selected, and then, in a heat treatment to follow, resistance films of various surface conditions are obtained. Carbon-added a-Si film formation conditions and the relationship between film qualities and solar cell characteristics are elucidated. In a solar cell of the p-i-n structure with an a-Si:C:H film acting as the p-layer, a conversion efficiency of 7.6% is achieved. (NEDO)

  15. Measuring the Plasma Density of a Ferroelectric Plasma Source in an Expanding Plasma

    International Nuclear Information System (INIS)

    Dunaevsky, A.; Fisch, N.J.

    2003-01-01

    The initial density and electron temperature at the surface of a ferroelectric plasma source were deduced from floating probe measurements in an expanding plasma. The method exploits negative charging of the floating probe capacitance by fast flows before the expanding plasma reaches the probe. The temporal profiles of the plasma density can be obtained from the voltage traces of the discharge of the charged probe capacitance by the ion current from the expanding plasma. The temporal profiles of the plasma density, at two different distances from the surface of the ferroelectric plasma source, could be further fitted by using the density profiles for the expanding plasma. This gives the initial values of the plasma density and electron temperature at the surface. The method could be useful for any pulsed discharge, which is accompanied by considerable electromagnetic noise, if the initial plasma parameters might be deduced from measurements in expanding plasma

  16. Feasibility of achieving gain in transition to the ground state of C VI at 3.4 nm

    International Nuclear Information System (INIS)

    Avitzour, Yoav; Suckewer, Szymon

    2007-01-01

    We present numerical studies of recombination gain in the transition to the ground state of H-like C (2→1 transition at λ=3.4 nm). It is shown that high gain (up to about 180 cm -1 ) can be achieved using currently available, relatively compact, laser technology. The model includes the ionization of the plasma by an ultraintense, ultrashort laser pulse, followed by plasma expansion, cooling, and recombination. Transient population inversion is generated during the recombination process. We investigate the behavior of the gain with respect to different plasma parameters and pump pulse parameters and explain how the different properties of the plasma and the pump pulse affect the gain

  17. Design Considerations in Capacitively Coupled Plasmas

    Science.gov (United States)

    Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

    2015-11-01

    Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

  18. Development of plasma cathode electron guns

    Science.gov (United States)

    Oks, Efim M.; Schanin, Peter M.

    1999-05-01

    The status of experimental research and ongoing development of plasma cathode electron guns in recent years is reviewed, including some novel upgrades and applications to various technological fields. The attractiveness of this kind of e-gun is due to its capability of creating high current, broad or focused beams, both in pulsed and steady-state modes of operation. An important characteristic of the plasma cathode electron gun is the absence of a thermionic cathode, a feature which leads to long lifetime and reliable operation even in the presence of aggressive background gas media and at fore-vacuum gas pressure ranges such as achieved by mechanical pumps. Depending on the required beam parameters, different kinds of plasma discharge systems can be used in plasma cathode electron guns, such as vacuum arcs, constricted gaseous arcs, hollow cathode glows, and two kinds of discharges in crossed E×B fields: Penning and magnetron. At the present time, plasma cathode electron guns provide beams with transverse dimension from fractional millimeter up to about one meter, beam current from microamperes to kiloamperes, beam current density up to about 100 A/cm2, pulse duration from nanoseconds to dc, and electron energy from several keV to hundreds of keV. Applications include electron beam melting and welding, surface treatment, plasma chemistry, radiation technologies, laser pumping, microwave generation, and more.

  19. Study of plasma detachment in a simplified 2D geometry using UEDGE

    International Nuclear Information System (INIS)

    Groth, M.; Porter, G.D.; Rognlien, T.D.; Mahdavi, A.M.

    2002-01-01

    A generic plasma in a two-dimensional slab geometry has been used to study the location of the ionisation front in dependence of the core plasma density and input heating power. The ratio of the recombination to ionisation current and the volumetric momentum losses in the computational domain have been used to quantify the degree of detachment. Contours of constant ratio of these parameters in the core plasma density - heating power parameter space indicate that high volumetric momentum losses can be achieved at high heating power and even low core plasma density. High fractions of recombination to ionisation, however, at high heating power also require high core densities to sufficiently separate the plasma from the target plate. (orig.)

  20. Influence of spark plasma sintering parameters on the mechanical properties of Cu{sub 50}Zr{sub 45}Al{sub 5} bulk metallic glass obtained using metallic glass powder

    Energy Technology Data Exchange (ETDEWEB)

    Cardinal, S. [Université de Lyon, CNRS (France); INSA-Lyon, MATEIS UMR5510, F-69621 Villeurbanne (France); Pelletier, J.M., E-mail: jean-marc.pelletier@insa-lyon.fr [Université de Lyon, CNRS (France); INSA-Lyon, MATEIS UMR5510, F-69621 Villeurbanne (France); Qiao, J.C. [School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi’an 710072 (China); Bonnefont, G. [Université de Lyon, CNRS (France); INSA-Lyon, MATEIS UMR5510, F-69621 Villeurbanne (France); Xie, G. [Institute for Materials Research, Tohoku University, Sendai (Japan)

    2016-11-20

    Gas atomized Cu{sub 50}Zr{sub 45}Al{sub 5} amorphous powder was densified by spark plasma sintering, in order to obtain bulk metallic glasses with larger size than that obtained by the conventional casting strategy. The influence of different parameters was investigated: sintering temperature, isothermal holding time as well as size of the specimens. After optimization of the processing parameters, dense and amorphous specimens were elaborated with a diameter up to 30 mm. Thermal stability and mechanical properties of consolidated samples are similar to those of Cu{sub 50}Zr{sub 45} Al{sub 5} cast alloy. A hardness of 535 HV and a compressive strength of 1600 MPa have been obtained. Fractographic investigation indicated an intergranular rupture mode which leads to lower toughness compared to as the cast material, but for these samples the size is limited to 3 mm. However an increase in applied pressure (from 90 MPa to 1 GPa) induces a significant improvement in bonding between powder particles.

  1. Parametric studies in a small plasma focus device

    International Nuclear Information System (INIS)

    Chuaqui, H.; Favre, M.; Silva, P.; Wyndham, E.

    1996-01-01

    Very high temperature and density plasmas can be produced in modest size plasma focus devices at the kJ level. Much of the scaling parameters on the plasma focus have been evaluated, though many questions still remain. The modest cost and simple construction allows easy modification to the device and the discharge parameters. In this paper the authors report on a small plasma focus device, which is set-up to investigate the effect of some of those modifications on the plasma, with detailed experimental diagnostics. Experiments have been carried out in various gases and with mixtures of different ratios. Extended operating range from below 0.5 torr upwards has been achieved with the implementation of the auxiliary discharge circuit. Despite the low voltage and low energy operation, energetic beam formation has been observed at the time of the final compression, prior to disruption. Current sheath formation and evolution has been characterized using the magnetic probes array, in correlation with beam formation and plasma emission. The relationship of the current sheath structure and that of the pinched plasma, as shown by the filtered X-ray pinhole camera, has been investigated

  2. Plasma based accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  3. Gas injected washer plasma gun

    International Nuclear Information System (INIS)

    Jain, K.K.; John, P.I.; Punithavelu, A.M.; Rao, P.P.

    1980-01-01

    A plasma gun similar in geometry to the washer plasma gun has been operated with gas injected externally. hydrogen, nitrogen and argon plasmas have been ionised and accelerated to velocities of the order of 10 7 mm s -1 and densities 10 11 mm -3 . Higher parameter range is possible with higher electrical input power. (author)

  4. High-temperature plasma physics

    International Nuclear Information System (INIS)

    Furth, H.P.

    1988-03-01

    Both magnetic and inertial confinement research are entering the plasma parameter range of fusion reactor interest. This paper reviews the individual and common technical problems of these two approaches to the generation of thermonuclear plasmas, and describes some related applications of high-temperature plasma physics

  5. Steady state behavior of rotating plasmas in a vacuum-arc centrifuge

    International Nuclear Information System (INIS)

    Bittencourt, J.A.; Ludwig, G.O.

    1987-01-01

    The steady state behaviour of the fully ionized, multiple species, rotating, magnetized plasma in a vacuum-arc plasma centrifuge is described in detail. The analysis is based on a multiple species fluid model which includes electromagnetic, pressure gradient, centrifugal and collisional forces, for each species, in cylindrical geometry. It is shown that there is a family of theoretically possible dynamical equilibrium configurations, which can be achieved by different combinations of ion rotation velocity, radial ion density distribution and radial dependence of internal electric potential. The parametric dependences of the various plasma parameters under equilibrium conditions, including the ion separation factor, are presented for a nickel-copper plasma. The numerical results are analysed and discussed in light of experimentally measured plasma characteristics in a vacuum-arc plasma centrifuge. (author)

  6. Steady state behavior of rotating plasmas in a vacuum-arc centrifuge

    International Nuclear Information System (INIS)

    Bittencourt, J.A.; Ludwig, G.O.

    1986-06-01

    The steady state behavior of the fully ionized, multiple species, rotating, magnetized plasma in a vacuum-arc plasma centrifuge is described in detail. The analysis is based on a multiple species fluid model which includes electromagnetic, pressure gradient, centrifugal and collisional forces, for each species, in cylindrical geometry. It is showm that there is a family of theoretically possible dynamical equilibrium configurations, which can be achieved by different combinations of ion rotation velocity, radial ion density distribution and radial dependence of internal electric potential. The parametric dependences of the various plasma parameters under equilibrium conditions, including the ion separation factor, are presented for a nickel-copper plasma. The numerical results are analysed and discussed on light of experimentally measured plasma characteristics in a vacuum-arc plasma centrifuge. (Author) [pt

  7. Characterization of the plasma in magnetic multidipole discharges

    International Nuclear Information System (INIS)

    Ferreira, J.G.

    1988-09-01

    In this work, a caracterization of the discharge of the quiescent plasma machine of INPE, and an identification of the most relevant processes in the definition of its plasma properties, were achieved. Measurements of plasma potential, the floating potential, the temperature of the electrons, and the density of the plasma, for pressures ranging from 10 -3 to 10 -1 Pa and for discharge potentials for 45V to 120V were acomplished. These measurements were made with a Langmuir spherical probe with 1mm in diameter. In the whole range of operation the presence of two populations of electrons with distinct temperatures in the energy range from 1 to 10eV was observed, although for pressures approaching 10 -1 Pa the plasma tended to a single population of electrons with temperature of 1eV. The difference between plasma and floating potentials was observed to become smaller as the pressure raised, and the potential difference between plasma and anode reached a value around 2V when pressure raised above 10 -2 Pa. The plasma density increases approximately linearly with pressure, for values below 10 -2 Paa, but above 10 -1 Pa its increase with pressure is quite reduced. A study on the collision processes in the plasma volume and on loss processes to surfaces allowed to interpret qualitatively the observed plasma behavior and to estimate, by means of simple expressions, some of the plasma parameters. The loss areas for ions and primary electrons were estimated from experimental results. A simple quantitative model which allows the calculation of plasma density in the whole range of operation, reproduced the correct order of magnitude of experimental values. However, an additional work, both theoretical and experimental, is required to obtain better agreement between experimental and theoretical values. (author) [pt

  8. Farelo da vagem de algaroba associado a níveis de ureia na alimentação de ovinos: balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais=Mesquite pod meal associated with levels of urea on feeding sheep: nitrogen balance, plasma urea-N and ruminal parameters

    Directory of Open Access Journals (Sweden)

    João Gonsalves Neto

    2012-07-01

    Full Text Available Objetivou-se neste trabalho avaliar os efeitos da inclusão de ureia em dietas contendo farelo da vagem de algaroba sobre o balanço de nitrogênio, N-ureico no plasma e parâmetros ruminais em ovinos. Foram utilizados oito animais, machos castrados, com peso médio de 33,5 kg, distribuídos em dois quadrados latinos 4 x 4. Os tratamentos constituíram da inclusão de níveis de ureia na dieta, sendo: 0; 0,5; 1,0 e 1,5% da MS total. A dieta foi fornecida como dieta total na relação volumoso:concentrado de 40:60 com base na MS total da dieta. Foi realizada a coleta total de urina e fezes e determinada a excreção de nitrogênio. Foi coletado sangue, seguido com a extração do plasma e determinação do N-ureico. Para avaliação do pH e N-amoniacal no líquido ruminal foram utilizados quatro animais fistulados no rúmen. A ingestão de N (31,68 g dia-1 e perdas vias fecal (7,94 g dia-1 e urinária (9,95 g dia-1 não sofreram alterações. As concentrações de N-amoniacal e N-ureico no plasma aumentaram de forma linear. O pH ruminal foi semelhante entre os tratamentos. A inclusão de ureia não influencia o balanço de nitrogênio, porém eleva as concentrações de N-amoniacal no rúmen e N-ureico no plasma podendo influenciar o gasto de energia no organismo.The goal of this study was to evaluate the effects of including urea in diets containing mesquite pod meal on nitrogen balance, plasma urea-N and ruminal parameters. Eight gelded males, with mean weight of 33.5 kg, were divided into two 4 x 4 Latin squares. Treatments consisted of following urea levels in diet: 0, 0.5, 1.0 and 1.5% of total dry matter. The diet was provided as total diet a 40:60 forage: concentrate ratio based on total diet DM. Total urine and feces were collected and nitrogen excretion was determined. Blood was collected, followed by plasma extraction and quantification of urea nitrogen. To evaluate pH and ammonia-N in rumen fluid, four rumen fistulated animals were

  9. Sterilization by pure oxygen plasma and by oxygen-hydrogen peroxide plasma: an efficacy study.

    Science.gov (United States)

    Boscariol, M R; Moreira, A J; Mansano, R D; Kikuchi, I S; Pinto, T J A

    2008-04-02

    Plasma is an innovative sterilization method characterized by a low toxicity to operators and patients, and also by its operation at temperatures close to room temperatures. The use of different parameters for this method of sterilization and the corresponding results were analyzed in this study. A low-pressure inductive discharge was used to study the plasma sterilization processes. Oxygen and a mixture of oxygen and hydrogen peroxide were used as plasma source gases. The efficacy of the processes using different combinations of parameters such as plasma-generation method, type of gas, pressure, gas flow rate, temperature, power, and exposure time was evaluated. Two phases were developed for the processes, one using pure oxygen and the other a mixture of gases. Bacillus subtilis var. niger ATCC 9372 (Bacillus atrophaeus) spores inoculated on glass coverslips were used as biological indicators to evaluate the efficacy of the processes. All cycles were carried out in triplicate for different sublethal exposure times to calculate the D value by the enumeration method. The pour-plate technique was used to quantify the spores. D values of between 8 and 3 min were obtained. Best results were achieved at high power levels (350 and 400 W) using pure oxygen, showing that plasma sterilization is a promising alternative to other sterilization methods.

  10. Powder processing and spheroidizing with thermal inductively coupled plasma

    International Nuclear Information System (INIS)

    Nutsch, G.; Linke, P.; Zakharian, S.; Dzur, B.; Weiss, K.-H.

    2001-01-01

    Processing of advanced powder materials for the spraying industry is one of the most promising applications of the thermal RF inductively coupled plasma. By selecting the feedstock carefully and adjusting the RF plasma parameters, unique materials with high quality can be achieved. Powders injected in the hot plasma core emerge with modified shapes, morphology, crystal structure and chemical composition. Ceramic oxide powders such as Al 2 O 3 , ZrO 2 , SiO 2 are spheroidized with a high spheroidization rate. By using the RF induction plasma spheroidizing process tungsten melt carbide powders are obtained with a high spheroidization rate at high feeding rates by densification of agglomerated powders consisting of di-tungsten carbide and monocarbide with a definite composition. This kind of ball-like powders is particularly suited for wear resistant applications. (author)

  11. Plasma Electronics. Theoretical and Experimental Investigations of Plasma Nonlinearity in the Powerful Microwave Oscillators

    International Nuclear Information System (INIS)

    Bliokh, Yu.P.

    2001-01-01

    During more than 50 years of Plasma Electronics development a great number of experimental and theoretical results have been achieved. These results allow understanding of physical processes which originate under charged particles beams interaction with a plasma. However, one essential aspect of such interaction remains insufficiently studied. The question is about a correlation between conditions of microwave excitation by a beam in plasma and plasma parameters. Each of these effects, namely the influence of plasma parameters on conditions of microwave excitation by a beam and plasma parameters variations under the influence of propagating microwave radiation are well known and investigated enough. However their common action under beam-plasma instability (BPI) development were not studied systematically, although the role of such reciprocal influence on character of these processes may be very large. The aim of this report is a review of recent theoretical and experimental investigations of such plasma nonlinearity in plasma-filled trawling-wave tubes. N.M.Zemlyansky and E.A.Kornilov have done experiments in Kharkov Institute of Physics and Technology (KhPhTI). Development of the theoretical model was started in KhPhTI (Yu.P.Bliokh, Ya.B.Fainberg, M.G.Lyubarsky, and V.O.Podobinsky) and continues by author in Technion. The developed theory takes into account two main reasons of the plasma density redistribution: high frequency pressure (HFP) force which ''push out'' plasma from the regions with increased microwave amplitude, or microwave discharge, which appears in the region where amplitude is large enough. Displaced (under HFP action) or additionally originating (under (BPD) development) plasma propagates from the disturbance source in the form of slow plasma waves (for example, ion-sound or magneto-sound waves), and the BPI develops in the nonhomogeneous plasma. It changes both magnitude and longitudinal distribution of excited microwave amplitude. As a result

  12. Mathematical modeling plasma transport in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Quiang, Ji [Univ. of Illinois, Urbana-Champaign, IL (United States)

    1997-01-01

    In this work, the author applied a systematic calibration, validation and application procedure based on the methodology of mathematical modeling to international thermonuclear experimental reactor (ITER) ignition studies. The multi-mode plasma transport model used here includes a linear combination of drift wave branch and ballooning branch instabilities with two a priori uncertain constants to account for anomalous plasma transport in tokamaks. A Bayesian parameter estimation method is used including experimental calibration error/model offsets and error bar rescaling factors to determine the two uncertain constants in the transport model with quantitative confidence level estimates for the calibrated parameters, which gives two saturation levels of instabilities. This method is first tested using a gyroBohm multi-mode transport model with a pair of DIII-D discharge experimental data, and then applied to calibrating a nominal multi-mode transport model against a broad database using twelve discharges from seven different tokamaks. The calibrated transport model is then validated on five discharges from JT-60 with no adjustable constants. The results are in a good agreement with experimental data. Finally, the resulting class of multi-mode tokamak plasma transport models is applied to the transport analysis of the ignition probability in a next generation machine, ITER. A reference simulation of basic ITER engineering design activity (EDA) parameters shows that a self-sustained thermonuclear burn with 1.5 GW output power can be achieved provided that impurity control makes radiative losses sufficiently small at an average plasma density of 1.2 X 1020/m3 with 50 MW auxiliary heating. The ignition probability of ITER for the EDA parameters, can be formally as high as 99.9% in the present context. The same probability for concept design activity (CDA) parameters of ITER, which has smaller size and lower current, is only 62.6%.

  13. Mathematical modeling plasma transport in tokamaks

    International Nuclear Information System (INIS)

    Quiang, Ji

    1995-01-01

    In this work, the author applied a systematic calibration, validation and application procedure based on the methodology of mathematical modeling to international thermonuclear experimental reactor (ITER) ignition studies. The multi-mode plasma transport model used here includes a linear combination of drift wave branch and ballooning branch instabilities with two a priori uncertain constants to account for anomalous plasma transport in tokamaks. A Bayesian parameter estimation method is used including experimental calibration error/model offsets and error bar rescaling factors to determine the two uncertain constants in the transport model with quantitative confidence level estimates for the calibrated parameters, which gives two saturation levels of instabilities. This method is first tested using a gyroBohm multi-mode transport model with a pair of DIII-D discharge experimental data, and then applied to calibrating a nominal multi-mode transport model against a broad database using twelve discharges from seven different tokamaks. The calibrated transport model is then validated on five discharges from JT-60 with no adjustable constants. The results are in a good agreement with experimental data. Finally, the resulting class of multi-mode tokamak plasma transport models is applied to the transport analysis of the ignition probability in a next generation machine, ITER. A reference simulation of basic ITER engineering design activity (EDA) parameters shows that a self-sustained thermonuclear burn with 1.5 GW output power can be achieved provided that impurity control makes radiative losses sufficiently small at an average plasma density of 1.2 X 10 20 /m 3 with 50 MW auxiliary heating. The ignition probability of ITER for the EDA parameters, can be formally as high as 99.9% in the present context. The same probability for concept design activity (CDA) parameters of ITER, which has smaller size and lower current, is only 62.6%

  14. Tokamak-FED plasma-engineering assessments

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Lyon, J.F.; Rutherford, P.H.

    1981-01-01

    A wide range of plasma assumptions and scenarios has been examined for the current US tokamak FED concept, which aims to provide a controlled, long pulse (approx. 100 s) burning plasma with an energy amplification of greater than or equal to 5, a fusion power of 180 MW, and a neutron wall load of greater than or equal to 0.4 MW/m 2 . The results of the assessment suggest that the current FED baseline parameters of R = 5.0 m, B/sub t/ = 3.6 T, a = 1.3 m, b = 2.1 m (D-shape), and I/sub p/ = 5.4 MA are appropriate in reaching the above plasma performance, despite uncertainties in several plasma physics areas, such as confinement scaling, achievable beta, impurity control, etc. To enhance the probability of achieving fusion ignition and to provide some margin against a short fall in our physics projections in FED, a limited operating capability at B/sub t/ = 4.6 T and I/sub p/ = 6.5 MA is incorporated. Various other options and remedies have also been assessed aiming to alleviate the impact of the uncertainties on the FED design concept. These approaches appear promising because they can be studied within the current fusion physics program and may lead to drastically more cost-effective FED concepts

  15. Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

    International Nuclear Information System (INIS)

    Zanáška, M.; Kudrna, P.; Tichý, M.; Adámek, J.; Peterka, M.

    2015-01-01

    The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents I sat − /I sat + to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa

  16. Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

    Science.gov (United States)

    Zanáška, M.; Adámek, J.; Peterka, M.; Kudrna, P.; Tichý, M.

    2015-03-01

    The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents Isat-/Isat+ to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.

  17. Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zanáška, M.; Kudrna, P.; Tichý, M. [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 12116 Prague 2 (Czech Republic); Adámek, J. [Institute of Plasma Physics AS CR, v.v.i., Za Slovankou 3, 18200 Prague 8 (Czech Republic); Peterka, M. [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 12116 Prague 2 (Czech Republic); Institute of Plasma Physics AS CR, v.v.i., Za Slovankou 3, 18200 Prague 8 (Czech Republic)

    2015-03-15

    The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents I{sub sat}{sup −}/I{sub sat}{sup +} to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.

  18. ECR Plasma Photos

    International Nuclear Information System (INIS)

    Racz, R.; Biri, S.; Palinkas, J.

    2009-01-01

    Complete text of publication follows. In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from He, methane, N, O, Ne, Ar, Kr, Xe gases and from their mixtures. The effects of the main external setting parameters (gas pressure, gas composition, magnetic field, microwave power, microwave frequency) were studied to the shape, color and structure of the plasma. The double frequency mode (9+14 GHz) was also realized and photos of this special 'star-in-star' shape plasma were recorded. A study was performed to analyze and understand the color of the ECR plasmas. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas. To our best knowledge our work is the first systematic study of ECR plasmas in the visible light region. When looking in the plasma chamber of an ECRIS we can see an axial image of the plasma (figure 1) in conformity with experimental setup. Most of the quantitative information was obtained through the summarised values of the Analogue Digital Unit (ADU) of pixels. By decreasing the strength of the magnetic trap we clearly observed that the brightness of the central part of the plasma gradually decreases, i.e. the plasma becomes more and more 'empty'. Figure 2 shows a photo series of ECR plasma at decreasing axial magnetic field. The radial size of the plasma increased because of the ascendant resonant zone. By increasing the power of the injected microwave an optimum (or at least saturation) was found in the brightness of the plasma. We found correlation between the gas dosing rates and plasma intensities. When sweeping the frequency of the microwave in a wide region

  19. The impact of boundary plasma conditions on the plasma performance of the Wendelstein 7-AS stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Grigull, P; Behrisch, R; Brakel, R; Burhenn, R; Elsner, A; Hacker, H; Hartfuss, H J; Herre, G; Hildebrandt, D; Jaenicke, R; Kisslinger, J; Maassberg, H; Mahn, C; Niedermeyer, H; Pech, P; Renner, H; Ringler, H; Rau, F; Roth, J; Sardei, F; Schneider, U; Wagner, F; Weller, A; Wobig, H; Wolff, H [Max-Planck-Inst. fuer Plasmaphysik, Garching (Germany); W7-AS Team; NBI Team; ECRH Group

    1992-12-01

    In the modular advanced stellarator W7-AS, the plasma performance and the main characteristics of the plasma-wall interaction are strongly affected by the three-dimensional edge topology. Both limiter- and separatrix-dominated configurations are possible. TiC and bulk-boronized limiter materials have been used. The impurity behaviour and the accessible plasma parameter ranges are compared for different limiter and wall conditions. With limiters, optimum plasma performance in currentless ECRF- or NBI-heated discharges was achieved with bulk-boronized graphite limiter material and boronized walls. Solid target sputter boronization, however, was found to be ineffective in comparison with boronization by He/B[sub 2]H[sub 6] glow discharge. For separatrix-dominated discharges, conditioning by wall coating has short-term effects only. Enhanced, localized plasma outflow to the wall due to islands at the boundary quickly erodes the layers. The possibility to develop a divertor concept is discussed. Basic properties of the plasma edge as derived from Langmuir probes and limiter calorimetry are described. Modeling is complicated by three-dimensionality. In a first approach, a 1D edge transport model on the basis of distinct flux bundles is applied. (orig.).

  20. Double plasma system with inductively coupled source plasma and quasi-quiescent target plasma

    International Nuclear Information System (INIS)

    Massi, M.; Maciel, H.S.

    1995-01-01

    Cold plasmas have successfully been used in the plasma-assisted material processing industry. An understanding of the physicochemical mechanisms involved in the plasma-surface interaction is needed for a proper description of deposition and etching processes at material surfaces. Since these mechanisms are dependent on the plasma properties, the development of diagnostic techniques is strongly desirable for determination of the plasma parameters as well as the characterization of the electromagnetic behaviour of the discharge. In this work a dual discharge chamber, was specially designed to study the deposition of thin films via plasma polymerization process. In the Pyrex chamber an inductively coupled plasma can be excited either in the diffuse low density E-mode or in the high density H-mode. This plasma diffuses into the cylindrical stainless steel chamber which is covered with permanent magnets to produce a multidipole magnetic field configuration at the surface. By that means a double plasma is established consisting of a RF source plasma coupled to a quasi-quiescent target plasma. The preliminary results presented here refer to measurements of the profiles of plasma parameters along the central axis of the double plasma apparatus. Additionally a spectrum analysis performed by means of a Rogowski coil probe immersed into the source plasma is also presented. The discharge is made in argon with pressure varying from 10 -2 to 1 torr, and the rf from 10 to 150 W

  1. Magnetospheric plasma waves

    International Nuclear Information System (INIS)

    Shawhan, S.D.

    1977-01-01

    A brief history of plasma wave observations in the Earth's magnetosphere is recounted and a classification of the identified plasma wave phenomena is presented. The existence of plasma waves is discussed in terms of the characteristic frequencies of the plasma, the energetic particle populations and the proposed generation mechanisms. Examples are given for which plasmas waves have provided information about the plasma parameters and particle characteristics once a reasonable theory has been developed. Observational evidence and arguments by analogy to the observed Earth plasma wave processes are used to identify plasma waves that may be significant in other planetary magnetospheres. The similarities between the observed characteristics of the terrestrial kilometric radiation and radio bursts from Jupiter, Saturn and possibly Uranus are stressed. Important scientific problems concerning plasma wave processes in the solar system and beyond are identified and discussed. Models for solar flares, flare star radio outbursts and pulsars include elements which are also common to the models for magnetospheric radio bursts. Finally, a listing of the research and development in terms of instruments, missions, laboratory experiments, theory and computer simulations needed to make meaningful progress on the outstanding scientific problems of plasma wave research is given. (Auth.)

  2. Particle beams and plasmas

    International Nuclear Information System (INIS)

    Hofmann, A.; Messerschmid, E.; Lawson, J.D.

    1976-01-01

    These lectures present a survey of some of the concepts of plasma physics and look at some situations familiar to particle-accelerator physicists from the point of view of a plasma physicist, with the intention of helping to link together the two fields. At the outset, basic plasma concepts are presented, including definitions of a plasma, characteristic parameters, magnetic pressure and confinement. This is followed by a brief discussion on plasma kinetic theory, non-equilibrium plasma, and the temperature of moving plasmas. Examples deal with beams in the CERN Intersecting Storage Rings as well as with non-steady beams in cyclic accelerators and microwave tubes. In the final chapters, time-varying systems are considered: waves in free space and the effect of cylinder bounds, wave motion in cold stationary plasmas, and waves in plasmas with well-defined streams. The treatment throughout is informal, with emphasis on the essential physical properties of continuous beams in accelerators and storage rings in relation to the corresponding problems in plasma physics and microwave tubes. (Author)

  3. Plasma turbulence

    International Nuclear Information System (INIS)

    Horton, W.

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates

  4. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian

    2011-01-01

    of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set......In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  5. Plasma processing of superconducting radio frequency cavities

    Science.gov (United States)

    Upadhyay, Janardan

    The development of plasma processing technology of superconducting radio frequency (SRF) cavities not only provides a chemical free and less expensive processing method, but also opens up the possibility for controlled modification of the inner surfaces of the cavity for better superconducting properties. The research was focused on the transition of plasma etching from two dimensional flat surfaces to inner surfaces of three dimensional (3D) structures. The results could be applicable to a variety of inner surfaces of 3D structures other than SRF cavities. Understanding the Ar/Cl2 plasma etching mechanism is crucial for achieving the desired modification of Nb SRF cavities. In the process of developing plasma etching technology, an apparatus was built and a method was developed to plasma etch a single cell Pill Box cavity. The plasma characterization was done with the help of optical emission spectroscopy. The Nb etch rate at various points of this cavity was measured before processing the SRF cavity. Cylindrical ring-type samples of Nb placed on the inner surface of the outer wall were used to measure the dependence of the process parameters on plasma etching. The measured etch rate dependence on the pressure, rf power, dc bias, temperature, Cl2 concentration and diameter of the inner electrode was determined. The etch rate mechanism was studied by varying the temperature of the outer wall, the dc bias on the inner electrode and gas conditions. In a coaxial plasma reactor, uniform plasma etching along the cylindrical structure is a challenging task due to depletion of the active radicals along the gas flow direction. The dependence of etch rate uniformity along the cylindrical axis was determined as a function of process parameters. The formation of dc self-biases due to surface area asymmetry in this type of plasma and its variation on the pressure, rf power and gas composition was measured. Enhancing the surface area of the inner electrode to reduce the

  6. High kinetic energy plasma jet generation and its injection into the Globus-M spherical tokamak

    International Nuclear Information System (INIS)

    Voronin, A.V.; Gusev, V.K.; Petrov, Yu.V.; Sakharov, N.V.; Abramova, K.B.; Sklyarova, E.M.; Tolstyakov, S.Yu.

    2005-01-01

    Progress in the theoretical and experimental development of the plasma jet source and injection of hydrogen plasma and neutral gas jets into the Globus-M spherical tokamak is discussed. An experimental test bed is described for investigation of intense plasma jets that are generated by a double-stage plasma gun consisting of an intense source for neutral gas production and a conventional pulsed coaxial accelerator. A procedure for optimizing the accelerator parameters so as to achieve the maximum possible flow velocity with a limited discharge current and a reasonable length of the coaxial electrodes is presented. The calculations are compared with experiment. Plasma jet parameters, among them pressure distribution across the jet, flow velocity, plasma density, etc, were measured. Plasma jets with densities of up to 10 22 m -3 , total numbers of accelerated particles (1-5) x 10 19 , and flow velocities of 50-100 km s -1 were successfully injected into the plasma column of the Globus-M tokamak. Interferometric and Thomson scattering measurements confirmed deep jet penetration and a fast density rise ( 19 to 1 x 10 19 ) did not result in plasma degradation

  7. A new multi-line cusp magnetic field plasma device (MPD) with variable magnetic field

    Science.gov (United States)

    Patel, A. D.; Sharma, M.; Ramasubramanian, N.; Ganesh, R.; Chattopadhyay, P. K.

    2018-04-01

    A new multi-line cusp magnetic field plasma device consisting of electromagnets with core material has been constructed with a capability to experimentally control the relative volume fractions of magnetized to unmagnetized plasma volume as well as accurate control on the gradient length scales of mean density and temperature profiles. Argon plasma has been produced using a hot tungsten cathode over a wide range of pressures 5 × 10-5 -1 × 10-3 mbar, achieving plasma densities ranging from 109 to 1011 cm-3 and the electron temperature in the range 1-8 eV. The radial profiles of plasma parameters measured along the non-cusp region (in between two consecutive magnets) show a finite region with uniform and quiescent plasma, where the magnetic field is very low such that the ions are unmagnetized. Beyond that region, both plasma species are magnetized and the profiles show gradients both in temperature and density. The electrostatic fluctuation measured using a Langmuir probe radially along the non-cusp region shows less than 1% (δIisat/Iisat physics parameter space relevant to both laboratory multi-scale plasmas and astrophysical plasmas.

  8. Characterization of a segmented plasma torch assisted High Heat Flux (HHF) system for performance evaluation of plasma facing components in fusion devices

    International Nuclear Information System (INIS)

    Ngangom, Aomoa; Sarmah, Trinayan; Sah, Puspa; Kakati, Mayur; Ghosh, Joydeep

    2015-01-01

    A wide variety of high heat and particle flux test facilities are being used by the fusion community to evaluate the thermal performance of plasma facing materials/components, which includes electron beam, ion beam, neutral beam and thermal plasma assisted sources. In addition to simulate heat loads, plasma sources have the additional advantage of reproducing exact fusion plasma like conditions, in terms of plasma density, temperature and particle flux. At CPP-IPR, Assam, we have developed a high heat and particle flux facility using a DC, non-transferred, segmented thermal plasma torch system, which can produce a constricted, stabilized plasma jet with high ion density. In this system, the plasma torch exhausts into a low pressure chamber containing the materials to be irradiated, which produces an expanded plasma jet with more uniform profiles, compared to plasma torches operated at atmospheric pressure. The heat flux of the plasma beam was studied by using circular calorimeters of different diameters (2 and 3 cm) for different input power (5-55 kW). The effect of the change in gas (argon) flow rate and mixing of gases (argon + hydrogen) was also studied. The heat profile of the plasma beam was also studied by using a pipe calorimeter. From this, the radial heat flux was calculated by using Abel inversion. It is seen that the required heat flux of 10 MW/m 2 is achievable in our system for pure argon plasma as well as for plasma with gas mixtures. The plasma parameters like the temperature, density and the beam velocity were studied by using optical emission spectroscopy. For this, a McPherson made 1.33 meter focal length spectrometer; model number 209, was used. A plane grating with 1800 g/mm was used which gave a spectral resolution of 0.007 nm. A detailed characterization with respect to these plasma parameters for different gas (argon) flow rate and mixing of gases (argon+hydrogen) for different input power will be presented in this paper. The plasma

  9. Controlled modification of octadecyltrichlorosilane self-assembled monolayer by CO2 plasma

    International Nuclear Information System (INIS)

    Delorme, Nicolas; Bardeau, Jean-Francois; Bulou, Alain; Poncin-Epaillard, Fabienne

    2006-01-01

    CO 2 -plasma is used to introduce functional groups on the uppermost surface of an alkoxy silane self-assembled monolayer (Sam). The structural and chemical modifications of the material surface were monitored by X-ray reflectometry, atomic force microscopy, X-ray photoelectrons spectroscopy and water contact angle measurements. Optimization of the plasma parameters is performed in order to achieve a maximum functionalization and to prevent degradation of the SAM. Finally, the ability of grafting organic compounds onto the plasma modified SAMS was demonstrated by the formation of an alkoxysilane bilayer

  10. Deviations from thermal equilibrium in plasmas

    International Nuclear Information System (INIS)

    Burm, K.T.A.L.

    2004-01-01

    A plasma system in local thermal equilibrium can usually be described with only two parameters. To describe deviations from equilibrium two extra parameters are needed. However, it will be shown that deviations from temperature equilibrium and deviations from Saha equilibrium depend on one another. As a result, non-equilibrium plasmas can be described with three parameters. This reduction in parameter space will ease the plasma describing effort enormously

  11. Sheath and plasma parameters in a magnetized plasma system

    Indian Academy of Sciences (India)

    through the negatively biased grid from the source region into the diffused region. It is observed that the electron temperature increases with the magnetic field in the diffused region whereas it decreases in the source region of the system for a constant grid biasing voltage. Also, investigation is done to see the change of ...

  12. From stellar plasmas to laboratory plasmas: application to X and XUV opacity measurements

    International Nuclear Information System (INIS)

    Loisel, G.

    2011-01-01

    The general context of this thesis is the one of radiative properties of high energy density matter. Energy densities involved (>10 11 J/cm 3 ) implies that a large part of energy exchange goes through radiation-matter interactions. My studies deal with spectral opacity, a fundamental parameter for modelling stellar interiors and constitute a propitious observable to experimental tests of theoretical descriptions of hot and dense plasmas physics. Although the main application of my work is stellar plasmas it can be useful for plasma diagnostics in inertial confinement fusion. My work activities are centred on the experimental study of opacities of plasmas at local thermodynamic equilibrium for temperature conditions of a few tens eV (a few 100000 K) and a few mg/cm 3 in matter density. Plasmas are obtained in conditions as homogenous as possible using the radiative heating of a laser-irradiated cavity. Heating is provided through a laser beam of high energy (100-300 J) and with relatively long pulse duration of a few nanosecond. For such measurements we could benefit from the LULI lasers configuration coupling the nanosecond beam with a picosecond one used to perform on a short duration the measurement of the plasma transmission. The use of short pulse laser to produce a short time radiography beam was a first achievement for this kind of experience. In the spectral range of keV photons, absorbing transitions 2p-3d or 3d-4f of elements of moderate or high atomic number have been probed. They present absorption structures which shape results mainly of the competition between spin-orbit splitting and statistical broadening effects. It appeared that this competition depends strongly on the atomic number Z. Thus for similar plasma parameters we explored opacities of Iron, Nickel, Copper and Germanium (Z around 30) in a first series of measurement and the one of Barium, Samarium and Gadolinium (Z around 60) in a second campaign

  13. Parameter studies for a two-component fusion experiment

    International Nuclear Information System (INIS)

    Towner, H.H.

    1975-01-01

    The sensitivity of the energy multiplication of a two-component fusion experiment is examined relative to the following parameters: energy confinement time (tau/sub E/), particle confinement time (tau/sub p/), effective Z of the plasma (Z/sub eff/), injection rate (j/sub I/) and injection energy (E/sub I/). The Energy Research and Development Administration recently approved funding for such a fusion device (the Toroidal Fusion Test Reactor or TFTR) which will be built at the Princeton Plasma Physics Laboratory. Hence, such a parameter study seems both timely and necessary. This work also serves as an independent check on the design values proposed for the TFTR to enable it to achieve energy breakeven (F = 1). Using the nominal TFTR design parameters and a self-consistent ion-electron power balance, the maximum F-value is found to be approximately 1.2 which occurs at an injection energy of approximately 210 KeV. The injector operation, i.e. its current and energy capability are shown to be a very critical factor in the TFTR performance. However, if the injectors meet the design objectives, there appears to be sufficient latitude in the other parameters to offer reasonable assurance that energy breakeven can be achieved. (U.S.)

  14. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1990-06-01

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  15. Fiscal 1998 achievement report on regional consortium research and development project. Venture business fostering regional consortium in its 2nd year--Creation of key industries (Development of multi-purpose high-precision plasma process); 1998 nendo tamokuteki koseido netsu plasma process no kaihatsu seika hokokusho. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Research and development is conducted of a new material process using thermal plasma for manufacturing new ceramics efficiently and for forming a high-quality spray-deposited ceramic coating high in melting point. In the development of devices, addition of an insulation convergence section enables the construction of a plasma jet generator which operates with stability across a range from atmospheric pressure through 10{sup -1} Torr and exhibits high thermal efficiency of approximately 70%. In the study of basic matters, the thermal plasma process is experimented for its optimization and the interaction between thermal plasma and injected materials is elucidated. In the development of a technology for manufacturing high-quality sprayed coatings, optimum plasma spraying conditions are established for each grain size of alumina/titania composite materials, with the rate of one component to the other taken into consideration. The optimum plasma spraying conditions are determined after examining the state of fused powder recovered after plasma spraying, porosity, the rate of coating adhesion, etc. It is found that coatings formed by high-power thermal plasma application are attributable to the vapor-solid process and, thanks to the finding, a crystal orientation control technology is developed for such coatings. (NEDO)

  16. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  17. Plasma sheath in non-Maxwellian plasma

    International Nuclear Information System (INIS)

    Shimizu, Takuo; Horigome, Takashi

    1992-01-01

    Reviewing many theoretical and experimental works on the electron-energy distributions (EEDF) of various plasmas, we point out that many plasmas have EEDF of non-Maxwellian in shape. Therefore, the recent treatment of plasma sheath using the Maxwell-Boltzmann distribution approximation should be improved. To do this, we have adopted Rutcher's standard distribution as a generalized form in place of the traditional Maxwellian, and found that the minimum energy of ions entering the sheath edge (Bohm's criterion) varies largely, and have also shown the variation of Debye length with the shape of EEDF. The length is the most important parameter to proceed with more detailed analysis on plasma-sheaths, and also to control them in the future. (author)

  18. Plasma sheath criterion in thermal electronegative plasmas

    International Nuclear Information System (INIS)

    Ghomi, Hamid; Khoramabadi, Mansour; Ghorannevis, Mahmod; Shukla, Padma Kant

    2010-01-01

    The sheath formation criterion in electronegative plasma is examined. By using a multifluid model, it is shown that in a collisional sheath there will be upper as well as lower limits for the sheath velocity criterion. However, the parameters of the negative ions only affect the lower limit.

  19. Plasma-material interactions

    International Nuclear Information System (INIS)

    Wilson, K.L.

    1984-01-01

    Plasma-interactive components must be resistant to erosion processes, efficient in heat removal, and effective in minimizing tritium inventory and permeation. As long as plasma edge temperatures are 50 eV, no one material can satisfy the diverse requirements imposed by these plasma materials interactions. The only solution is the design of duplex, or even more complicated, structures. The material that faces the plasma should be low atomic number, with acceptable erosion and evaporation characteristics. The substrate material must have high thermal conductivity for heat removal. Finally, materials must be selected judiciously for tritium compatibility. In conclusion, materials play a critical role in the achievement of safe and economical magnetic fusion energy. Improvements in materials have already led to many advances in present day device operation, but additional innovative materials solutions are required for the critical plasma materials interaction issues in future power reactors

  20. Self-organized ignition of a tokamak plasma

    International Nuclear Information System (INIS)

    Schoepf, K.

    2007-01-01

    The continuous progress in the attainment of plasma parameters required for establishing nuclear fusion in magnetically confined plasmas as well as the prospect of feasible steady-state operation has instigated the interest in the physics of burning plasmas [1]. Aside from the required plasma current drive, fusion energy production with tokamaks demands particular attention to confinement and fuelling regimes in order to maintain the plasma density n and temperature T at favourable values matching with specific requirements such as the triple product nτ E T, where τ E represents the plasma energy confinement time. The identification of state and parameter space regions capable of ignited fusion plasma operation is evidently crucial if significant energy gains are to be realized over longer periods. Examining the time-evolving state of tokamak fusion plasma in a parameter space spanned by the densities of plasma constituents and their temperatures has led to the formation of an ignition criterion [2] fundamentally different from the commonly used static patterns. The incorporation of non-stationary particle and energy balances into the analysis here, the application of a 'soft' Troyon beta limit [3], the consideration of actual fusion power deposition [4,5] and its effect of reducing τ E are seen to significantly influence the fusion burn dynamics and to shape the ignition conditions. The presented investigation refers to a somewhat upgraded (to achieve ignition) ITER-like tokamak plasma and uses volume averages of locally varying quantities and processes. The resulting ignition criterion accounts for the dynamic evolution of a reacting plasma controlled by heating and fuel feeding. Interestingly, also self-organized ignition can be observed: a fusion plasma possessing a density and temperature above a distinct separatrix in the considered parameter phase space is seen to evolve - without external heating and hence practically by itself - towards an ignited

  1. Optimization of laser-plasma injector via beam loading effects using ionization-induced injection

    Science.gov (United States)

    Lee, P.; Maynard, G.; Audet, T. L.; Cros, B.; Lehe, R.; Vay, J.-L.

    2018-05-01

    Simulations of ionization-induced injection in a laser driven plasma wakefield show that high-quality electron injectors in the 50-200 MeV range can be achieved in a gas cell with a tailored density profile. Using the PIC code Warp with parameters close to existing experimental conditions, we show that the concentration of N2 in a hydrogen plasma with a tailored density profile is an efficient parameter to tune electron beam properties through the control of the interplay between beam loading effects and varying accelerating field in the density profile. For a given laser plasma configuration, with moderate normalized laser amplitude, a0=1.6 and maximum electron plasma density, ne 0=4 ×1018 cm-3 , the optimum concentration results in a robust configuration to generate electrons at 150 MeV with a rms energy spread of 4% and a spectral charge density of 1.8 pC /MeV .

  2. Prospects for observing the magnetorotational instability in the plasma Couette experiment

    Science.gov (United States)

    Flanagan, K.; Clark, M.; Collins, C.; Cooper, C. M.; Khalzov, I. V.; Wallace, J.; Forest, C. B.

    2015-08-01

    Many astrophysical disks, such as protoplanetary disks, are in a regime where non-ideal, plasma-specific magnetohydrodynamic (MHD) effects can significantly influence the behaviour of the magnetorotational instability (MRI). The possibility of studying these effects in the plasma Couette experiment (PCX) is discussed. An incompressible, dissipative global stability analysis is developed to include plasma-specific two-fluid effects and neutral collisions, which are inherently absent in analyses of Taylor-Couette flows (TCFs) in liquid metal experiments. It is shown that with boundary driven flows, a ion-neutral collision drag body force significantly affects the azimuthal velocity profile, thus limiting the flows to regime where the MRI is not present. Electrically driven flow (EDF) is proposed as an alternative body force flow drive in which the MRI can destabilize at more easily achievable plasma parameters. Scenarios for reaching MRI relevant parameter space and necessary hardware upgrades are described.

  3. Plasma sprayed thermoregulating coatings

    International Nuclear Information System (INIS)

    Kudinov, V.V.; Puzanov, A.A.; Zambrzhitskij, A.P.; Soboleva, V.V.

    1979-01-01

    Shown is the possibility of plasma spraying application for thermoregulating coating formation. Given are test results of service properties of BeO, Al 2 O 2 plasma coatings on the substrates of the MA2-1 magnesium alloy. Described is a device for studying durability of coating optical parameters under ultraviolet irradiation in deep vacuum. Dynamics of absorption coefficient, growth caused by an increase in absorption centers amount under such irradiation is investigated

  4. Hydrogen production by thermal water splitting using a thermal plasma

    International Nuclear Information System (INIS)

    Boudesocque, N.; Lafon, C.; Girold, C.; Vandensteendam, C.; Baronnet, J.M.

    2006-01-01

    CEA has been working for more than 10 years in plasma technologies devoted to waste treatment: incineration, vitrification, gases and liquid treatment. Based on this experience, CEA experiments since several years an innovative route for hydrogen production by thermal water splitting, using a plasma as heat source. This new approach could be considered as an alternative to electrolysis for massive hydrogen production from water and electricity. This paper presents a brief state of the art of water thermal plasmas, showing the temperatures and quench velocity ranges technologically achievable today. Thermodynamic properties of a water plasma are presented and discussed. A kinetic computational model is presented, describing the behavior of splitted products during the quench in a plasma plume for various parameters, such as the quench rate. The model results are compared to gas analysis in the plasma plume obtained with in-situ sampling probe. The plasma composition measurements are issued from an Optical Emission Spectroscopic method (OES). The prediction of 30 % H 2 recovery with a 108 K.s -1 quench rate has been verified. A second experimentation has been performed: mass gas analysis, flowrate measurement and OES to study the 'behavior' and species in underwater electrical arc stricken between graphite electrodes. With this quench, a synthesis gas was produced with a content 55 % of hydrogen. (authors)

  5. A 14-MeV beam-plasma neutron source for materials testing

    International Nuclear Information System (INIS)

    Futch, A.H.; Coensgen, F.H.; Damm, C.C.; Molvik, A.W.

    1989-01-01

    The design and performance of 14-MeV beam-plasma neutron sources for accelerated testing of fusion reactor materials are described. Continuous production of 14-MeV neutron fluxes in the range of 5 to 10 MW/m 2 at the plasma surface are produced by D-T reactions in a two-component plasma. In the present designs, 14-MeV neutrons result from collisions of energetic deuterium ions created by transverse injection of 150-keV deuterium atoms on a fully ionized tritium target plasma. The beam energy, which deposited at the center of the tritium column, is transferred to the warm plasma by electron drag, which flows axially to the end regions. Neutral gas at high pressure absorbs the energy in the tritium plasma and transfers the heat to the walls of the vacuum vessel. The plasma parameters of the neutron source, in dimensionless units, have been achieved in the 2XIIB high-β plasma. The larger magnetic field of the present design permits scaling to the higher energy and density of the neutron source design. In the extrapolation, care has been taken to preserve the scaling and plasma attributes that contributed to equilibrium, magnetohydrodynamic (MHD) stability, and microstability in 2XIIB. The performance and scaling characteristics are described for several designs chosen to enhance the thermal isolation of the two-component plasmas. 11 refs., 3 figs., 3 tabs

  6. Some new radiation processes in plasmas

    International Nuclear Information System (INIS)

    Wu, C.S.

    1981-01-01

    Some new plasma radiation processes are reviewed, viz., (1) emission near the electron plasma frequency, (2) direct amplification of radiation near the electron cycloton frequency, and (3) parametic amplification of radiation by stimulated scattering. (L.C.) [pt

  7. Boltzmann equation analysis of electrons swarm parameters and properties of excited particle number densities in Xe/Ne plasmas. Laser absorption effect; Xe/Ne plasma chudenshi yuso keisu narabi ni reiki ryushisu mitsudo tokusei no Boltzmann hoteishiki kaiseki. Laser ko kyushu koka

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, S.; Sugawara, H.; Ventzek, P.; Sakai, Y. [Hokkaido University, Sapporo (Japan)

    1998-06-01

    Xe/Ne plasmas are important for plasma display panels and VUV light sources. However, reactions between electrons and excited particles in the mixtures are so complicated that influence of the reactions on the plasma properties is not understood well. In this work, taking account of reactions through which electrons are produced, such as cumulative and Penning ionization, and of transition between excited levels, the electron and excited particle properties in Xe/Ne plasmas are calculated using the Boltzmann equation. The ionization coefficient and electron drift velocity agreed with experimental data. The influence of laser absorption in Xe/Ne plasmas on the plasma properties is also discussed. 25 refs., 15 figs.

  8. Plasma electrolytic liquefaction of cellulosic biomass

    Science.gov (United States)

    Dingliang, TANG; Xianhui, ZHANG; Si-ze, YANG

    2018-04-01

    In this paper, the rapid liquefaction of a corncob was achieved by plasma electrolysis, providing a new method for cellulosic biomass liquefaction. The liquefaction rate of the corncob was 95% after 5 min with polyethylene glycol and glycerol as the liquefying agent. The experiments not only showed that H+ ions catalyzed the liquefaction of the corncob, but also that using accelerated H+ ions, which were accelerated by an electric field, could effectively improve the liquefaction efficiency. There was an obvious discharge phenomenon, in which the generated radicals efficiently heated the solution and liquefied the biomass, in the process of plasma electrolytic liquefaction. Finally, the optimum parameters of the corncob liquefaction were obtained by experimentation, and the liquefaction products were analyzed.

  9. Plasma technology of the surface polymer activation

    International Nuclear Information System (INIS)

    Dutra, Jorge C.N.; Mello, Sandra C.; Massi, Marcos; Otani, Choyu; Maciel, Homero S.; Bittencourt, Edison

    2005-01-01

    A number of polymers, especially rubbers, require surface treatment to achieve a satisfactory level of adhesion. The surface of EPDM rubber vulcanized is high hydrophobicity and is not suited for a number of potential applications, in particular, for adhering to the polyurethane liner of solid rocket propellants. In this case, plasma treatment can be a very attractive process because it can efficiently increase the surface energy attributed to surface oxidation with the introduction of polar groups 1, 2. In order to investigate the influence of the parameters on the modifications of the treated surface samples of EPDM rubber by plasma generated by gas oxygen and argon, the water and methylene iodide contact angles were measured at room temperature with an image analyzing using the sessile drop technique 3 - 6 . (author)

  10. General image acquisition parameters

    International Nuclear Information System (INIS)

    Teissier, J.M.; Lopez, F.M.; Langevin, J.F.

    1993-01-01

    The general parameters are of primordial importance to achieve image quality in terms of spatial resolution and contrast. They also play a role in the acquisition time for each sequence. We describe them separately, before associating them in a decision tree gathering the various options that are possible for diagnosis

  11. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described for electron beam heating of a high-density plasma to drive a fast liner. An annular or solid relativistic electron beam is used to heat a plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the plasma then converges on a fast liner to explosively or ablatively drive the liner to implosion. (U.K.)

  12. Tecnical report- Group of Plasma

    International Nuclear Information System (INIS)

    Sakanaka, P.H.; Boeckelmann, H.K.; Marotta, A.

    1985-01-01

    The research activities of Plasma Laboratory at UNICAMP (University of Campinas, Brazil) in the period from november 84 to july/85 are described. In the TUPA project, several works related to substructure and research programs were developed. Diagnostic techniques to analyse the theta Pinch implosion phase, a presure probe, an electrostatic ion energy analyser and laser-produced plasma spectroscopy were developed. The experimental results were obtained, using multiple magnetic probes inserted in the plasma. These results were analysed by numerical code using some MHD equations in 2 dimensions. A description of plasma dynamic was determined and the plasma parameters such as density and temperature were estimated. (M.C.K.) [pt

  13. Plasma Onco-Immunotherapy: Novel Approach to Cancer Treatment

    Science.gov (United States)

    Fridman, Alexander

    2015-09-01

    Presentation is reviewing the newest results obtained by researchers of A.J. Drexel Plasma Institute on direct application of non-thermal plasma for direct treatment of different types of cancer by means of specific stimulation of immune system in the frameworks of the so-called onco-immunotherapy. Especial attention is paid to analysis of depth of penetration of different plasma-medical effects, from ROS, RNS, and ions to special biological signaling and immune system related processes. General aspects of the plasma-stimulation of immune system are discussed, pointing out specific medical applications. Most of experiments have been carried out using nanosecond pulsed DBD at low power and relatively low level of treatment doses, guaranteeing non-damage no-toxicity treatment regime. The nanosecond pulsed DBD physics is discussed mostly regarding its space uniformity and control of plasma parameters relevant to plasma medical treatment, and especially relevant to depth of penetration of different plasma medical effects. Detailed mechanism of the plasma-induced onco-immunotherapy has been suggested based upon preliminary in-vitro experiments with DBD treatment of different cancer cells. Sub-elements of this mechanism related to activation of macrophages and dendritic cells, specific stressing of cancer cells and the immunogenic cell death (ICD) are to be discussed based on results of corresponding in-vitro experiments. In-vivo experiments focused on the plasma-induced onco-immunotherapy were carried out in collaboration with medical doctors from Jefferson University hospital of Philadelphia. Todays achievements and nearest future prospective of clinical test focused on plasma-controlled cancer treatment are discussed in conclusion.

  14. Plasma Modes

    Science.gov (United States)

    Dubin, D. H. E.

    This chapter explores several aspects of the linear electrostatic normal modes of oscillation for a single-species non-neutral plasma in a Penning trap. Linearized fluid equations of motion are developed, assuming the plasma is cold but collisionless, which allow derivation of the cold plasma dielectric tensor and the electrostatic wave equation. Upper hybrid and magnetized plasma waves in an infinite uniform plasma are described. The effect of the plasma surface in a bounded plasma system is considered, and the properties of surface plasma waves are characterized. The normal modes of a cylindrical plasma column are discussed, and finally, modes of spheroidal plasmas, and finite temperature effects on the modes, are briefly described.

  15. Plasma dynamics in a staged pinch device

    International Nuclear Information System (INIS)

    Khattak, N.A.D.; Ahmed, Z.; Mirza, A.M.; Murtaza, G.

    1998-01-01

    Plasma parameters in fiber initiated fast and dense theta-pinch plasma driven by an annular finite-thickness gas-puff Z-pinch are studied. The imploding gas-puff Z-pinch plasma traps an axial magnetic field B/sub z/, compressing it to large values (of the order of several megagauss) in an extremely short time. The rapidly changing magnetic flux of this field induces an azimuthal current on the surface of the coaxially placed fiber, with a rise time an order of magnitude shorter than the applied Z-pinch current. The shorter rise time of the current stabilizes the pinch against sausage mode of MHD instabilities. Our numerical results demonstrate that for a relatively thick gas-puff layer, the compression occurs before the current saturates. At the peak compression the fuel densities of the order of 10/sup 25/ cm/sup -3/ and temperature above 10 keV can be achieved on a time scale of 0.1 nanoseconds, yielding the Lawson Criterion parameters n tau is approximately equal to 10/sup 14/ sec cm/sup -3/ for D-T fuel. The snow-plow effect incorporated in our model exercise a strong influence on the onset and growth rate of sausage and Rayleigh-Taylor (R-T) modes of instabilities. Imposing a rotational velocity on the outer thin gas-puff plasma can control the Rayleigh-Taylor instability. Numerical results indicate that the choice of the spin velocity is critical. Large values of the spin velocity, though provide stabilization against the R-T instability at the final stage of compression, however, it adversely reduce the plasma parameters so essential to achieve controlled fusion. Our analysis, therefore, suggests that a judicious choice of the spin velocity is necessary to obtain the desired temperature and density, especially when we seed D-T fiber plasma with a small fraction of high-Z Kr impurity to initiate the radiative collapse. (author)

  16. Optimizing Pretreatment of Medicinal Raw Materials by RFC Plasma before Extraction

    Directory of Open Access Journals (Sweden)

    O.Yu. Kuznetsova

    2016-06-01

    Full Text Available Optimization of the RF-plasma treatment modes of chaga raw materials using the Statistica 6.0 software package has been performed. Mathematical design has been carried out to calculate the optimum parameters of RF-plasma treatment using three plasma-forming gases – argon, air, and nitrogen. Plasma treatment of chaga raw materials has been undertaken at the constant parameters: pressure P = 30.0 Pa, anodic current J = 0.7 A, gas consumption G = 0.04 g/s; the variable parameters were power U = 5.0÷7.0 kV and treatment duration at the high-frequency capacitor category of the lowered pressure t = 30÷60 min. Optimization of four key parameters for extraction of chaga raw materials (solid residue, melanin yield, antioxidant activity of both extract and chaga melanin depending on the chosen plasma-forming gas (argon, air, or nitrogen has been achieved. The optimum modes of RF-plasma treatment allowing to obtain the extracts and melanin of chaga mushroom with the improved physicochemical and antioxidant characteristics have been calculated.

  17. Inventory parameters

    CERN Document Server

    Sharma, Sanjay

    2017-01-01

    This book provides a detailed overview of various parameters/factors involved in inventory analysis. It especially focuses on the assessment and modeling of basic inventory parameters, namely demand, procurement cost, cycle time, ordering cost, inventory carrying cost, inventory stock, stock out level, and stock out cost. In the context of economic lot size, it provides equations related to the optimum values. It also discusses why the optimum lot size and optimum total relevant cost are considered to be key decision variables, and uses numerous examples to explain each of these inventory parameters separately. Lastly, it provides detailed information on parameter estimation for different sectors/products. Written in a simple and lucid style, it offers a valuable resource for a broad readership, especially Master of Business Administration (MBA) students.

  18. Current control for magnetized plasma in direct-current plasma-immersion ion implantation

    International Nuclear Information System (INIS)

    Tang Deli; Chu, Paul K.

    2003-01-01

    A method to control the ion current in direct-current plasma-immersion ion implantation (PIII) is reported for low-pressure magnetized inductively coupled plasma. The ion current can be conveniently adjusted by applying bias voltage to the conducting grid that separates plasma formation and implantation (ion acceleration) zones without the need to alter the rf input power, gas flux, or other operating conditions. The ion current that diminishes with an increase in grid bias in magnetized plasmas can be varied from 48 to 1 mA by increasing the grid voltage from 0 to 70 V at -50 kV sample bias and 0.5 mTorr hydrogen pressure. High implantation voltage and monoenergetic immersion implantation can now be achieved by controlling the ion current without varying the macroscopic plasma parameters. The experimental results and interpretation of the effects are presented in this letter. This technique is very attractive for PIII of planar samples that require on-the-fly adjustment of the implantation current at high implantation voltage but low substrate temperature. In some applications such as hydrogen PIII-ion cut, it may obviate the need for complicated sample cooling devices that must work at high voltage

  19. Non-thermal plasmas for non-catalytic and catalytic VOC abatement

    International Nuclear Information System (INIS)

    Vandenbroucke, Arne M.; Morent, Rino; De Geyter, Nathalie; Leys, Christophe

    2011-01-01

    Highlights: → We review the current status of catalytic and non-catalytic VOC abatement based on a vast number of research papers. → The underlying mechanisms of plasma-catalysis for VOC abatement are discussed. → Critical process parameters that determine the influent are discussed and compared. - Abstract: This paper reviews recent achievements and the current status of non-thermal plasma (NTP) technology for the abatement of volatile organic compounds (VOCs). Many reactor configurations have been developed to generate a NTP at atmospheric pressure. Therefore in this review article, the principles of generating NTPs are outlined. Further on, this paper is divided in two equally important parts: plasma-alone and plasma-catalytic systems. Combination of NTP with heterogeneous catalysis has attracted increased attention in order to overcome the weaknesses of plasma-alone systems. An overview is given of the present understanding of the mechanisms involved in plasma-catalytic processes. In both parts (plasma-alone systems and plasma-catalysis), literature on the abatement of VOCs is reviewed in close detail. Special attention is given to the influence of critical process parameters on the removal process.

  20. An improved barium plasma source for q-machines

    International Nuclear Information System (INIS)

    Paris, P.J.; Gorgerat, P.; Simik, A.; Rynn, N.; Roe, S.; Schleipen, M.

    1988-06-01

    We have developed a stable q-machine with well determined parameters for long term times, of constant plasma density and temperature. The plasma characteristics and gun behaviour allow research in fundamental plasma physics, especially with the use of non perturbing powerful optical (LIF) diagnostics in the determination of many of the plasma parameters. (author) 17 figs., 2 tabs., 7 refs

  1. Development and application of helicon plasma sources. Evolution of extensive plasma science

    International Nuclear Information System (INIS)

    Shinohara, Shunjiro

    2009-01-01

    Recent advances in plasma science are remarkable, and are deeply indebted to the development of sophisticated plasma sources. While numerous methods have been proposed for producing the plasma, helicon plasma sources, capable of generating high density (>10 13 cm -3 ) plasma with high ionization degree (>several ten percent) over a wide range of external control parameters, have been utilized in such broad areas as fundamental and processing plasmas, nuclear fusion, gas laser, modeling of space plasma, plasma acceleration/propulsion, among others. On the other hand, a number of important issues are left unsolved, in particular, those relevant to the wave phenomena and efficient plasma production. Solution to these issues are expected to play key roles in taking full advantage of the helicon plasma sources in the next generation. In this article, we overview our current understanding of the helicon plasma production and recent development of characteristic helicon plasma sources, and discuss possible future advancement of extensive plasma science utilizing them. (author)

  2. The compact mirrors with high pressure plasmas

    International Nuclear Information System (INIS)

    Anikeev, A.V.; Bagryansky, P.A.; Ivanov, A.A.; Lizunov, A.A.; Murakhtin, S.V.; Prikhodko, V.V.; Collatz, S.; Noack, K.

    2004-01-01

    The gas dynamic trap (GDP) experimental facility at the Budker Institute Novosibirsk is a long axial-symmetric mirror system with a high mirror ratio variable in the range of 12.5 - 100 for the confinement of a two-component plasma. One component is a collisional plasma with ion and electron temperatures up to 100 eV and density up to 10 14 cm -3 . The second component is the population of high-energetic fast ions with energies of 2-18 keV and a density up to 10 13 cm -3 which is produced by neutral beam injection (NBI). GDP is currently undergoing an upgrade whose first stage is the achievement of the synthesized hot ion plasmoid experiment (SHIP). This experiment aims at the investigation of plasmas and at the knowledge of plasma parameters that have never been achieved before in magnetic mirrors. The paper presents the physical concept of the SHIP experiment, the results of numerical pre-calculations and draws conclusions regarding possible scenarios of experiments. The simulation of a maximal NBI power regime with hydrogen injection gave a fast ion density of 1.2*10 14 cm -3 with a mean energy of 14 keV. The calculation of the deuterium injection regime with 2 MW NBI power gave a maximal fast ion density of 1.9*10 14 cm -3 with a beam energy of 9 keV. The calculation of an experimental scenario with reduced magnetic field resulted in a maximal β-value of 62%, so this regime is recommended for the study of high-β effects in plasmas confined in axial-symmetric mirrors

  3. 2XIIB plasma confinement experiments

    International Nuclear Information System (INIS)

    Coensgen, F.H.; Clauser, J.F.; Correll, D.L.

    1976-01-01

    This paper reports results of 2XIIB neutral-beam injection experiments with plasma-stream stabilization. The plasma stream is provided either by a pulsed plasma generator located on the field lines outside the plasma region or by ionization of neutral gas introduced at the mirror throat. In the latter case, the gas is ionized by the normal particle flux through the magnetic mirror. A method of plasma startup and sustenance in a steady-state magnetic field is reported in which the plasma stream from the pulsed plasma generator serves as the initial target for the neutral beams. After an energetic plasma of sufficient density is established, the plasma generator stream is replaced by the gas-fed stream. Lifetimes of the stabilized plasma increase with plasma temperature in agreement with the plasma stabilization of the drift-cyclotron loss-cone mode. The following plasma parameters are attained using the pulsed plasma generator for stabilization: n approximately 5 x 10 13 cm -3 , anti W/sub i/ approximately 13 keV, T/sub e/ = 140 eV, and ntau/sub p/ approximately 7 x 10 10 cm -3 .s. With the gas feed, the mean deuterium ion energy is 9 keV and the peak density n approximately 10 14 cm -3 . In the latter case, the energy confinement parameter reaches ntau/sub E/ = 7 x 10 10 cm -3 .s, and the particle confinement parameter reaches ntau/sub p/ = 1 x 10 11 cm -3 .s

  4. Converging-barrel plasma accelerator

    International Nuclear Information System (INIS)

    Paine, T.O.

    1971-01-01

    The invention comprises a device for generating and accelerating plasma to extremely high velocity, while focusing the plasma to a decreasing cross section for attaining a very dense high-velocity plasma burst capable of causing nuclear fusion reactions. A converging coaxial accelerator-electrode configuration is employed with ''high-pressure'' gas injection in controlled amounts to achieve acceleration by deflagration and focusing by the shaped electromagnetic fields. (U.S.)

  5. Plasma opening switch with extrinsic magnetic field

    CERN Document Server

    Dolgachev, G; Maslennikov, D

    2001-01-01

    Summary form only given, as follows. We have demonstrated in series of experiments that plasma opening switch (POS) switching voltage (UPOS) is defined by energy density (w) deposited in the POS plasma. If we then consider a plasma erosion mainly responsible for the effect of POS switching (the erosion effect could be described by Hall or Child-Langmuir models) the energy density (w) could be measured as a function of a system "macro-parameter" such as the initial charging voltage of the capacity storage system (the Marx pulsed voltage generator) UMarx. The POS voltage in this case could be given by UPOS"aw=aUMarx4/7, where a is a constant. This report demonstrates that for the high-impedance POS which has limited charge density transferred through the POS plasma a"2.5 (MV3/7) with no external magnetic field applied. The use of the extrinsic magnetic field allows to increase a up to 3.6 (MV3/7) and to achieve higher voltages at the opening phase - UPOS=3.6UMarx4/7. To verify this approach set of experimental ...

  6. Plasma spheroidization of nickel powders in a plasma reactor

    Indian Academy of Sciences (India)

    Unknown

    and size of the particles are among critical parameters ... shape components, which helps to conserve scarce raw materials. There are several methods of producing rapidly solidi- ... spherical nickel powders using the d.c. plasma reactor is.

  7. Very high plasma switches. Basic plasma physics and switch technology

    International Nuclear Information System (INIS)

    Doucet, H.J.; Roche, M.; Buzzi, J.M.

    1988-01-01

    A review of some high power switches recently developed for very high power technology is made with a special attention to the aspects of plasma physics involved in the mechanisms, which determine the limits of the possible switching parameters

  8. Plasma centrifuges

    International Nuclear Information System (INIS)

    Karchevskij, A.I.; Potanin, E.P.

    2000-01-01

    The review of the most important studies on the isotope separation processes in the rotating plasma is presented. The device is described and the characteristics of operation of the pulse plasma centrifuges with weakly and strongly ionized plasma as well as the stationary plasma centrifuges with the medium weak ionization and devices, applying the stationary vacuum arc with the high ionization rate and the stationary beam-plasma discharge with complete ionization, are presented. The possible mechanisms of the isotope separation in plasma centrifuges are considered. The specific energy consumption for isotope separation in these devices is discussed [ru

  9. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  10. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  11. Turbulent transport in magnetized plasmas

    CERN Document Server

    Horton, Wendell

    2012-01-01

    This book explains how magnetized plasmas self-organize in states of electromagnetic turbulence that transports particles and energy out of the core plasma faster than anticipated by the fusion scientists designing magnetic confinement systems in the 20th century. It describes theory, experiments and simulations in a unified and up-to-date presentation of the issues of achieving nuclear fusion power.

  12. Beam-plasma interaction with an electron beam injecting into a symmetrically open plasma system; Electron beam relaxation. Puchkovo-plazmennoe vzaimodejstvie pri inzhektsii ehlektronnogo puchka v simmetrichno otkrytuyu plazmennuyu sistemu; Relaksatsiya ehlektronnogo puchka

    Energy Technology Data Exchange (ETDEWEB)

    Opanasenko, A V; Romanyuk, L I [AN Ukrainskoj SSR, Kiev (Ukrainian SSR). Inst. Yadernykh Issledovanij

    1989-10-01

    The relaxation of the electron beam with the electron density of 1-2 keV injected through the symmetrically open plasma system with the independent hot cathode Penning discharge is experimentally investigated. It is shown that the velocity distribution function of the electron beam changes after passing each wave generation zone induced by the beam. The contribution of different wave zones to the beam relaxation depends on the prehistory of the beam-plasma interaction and may be regulated by the selection of the plasma system parameters. By this way the complete relaxation of the electron beam can be achieved after the beam crossing the whole system.

  13. Theoretical approach for plasma series resonance effect in geometrically symmetric dual radio frequency plasma

    International Nuclear Information System (INIS)

    Bora, B.; Bhuyan, H.; Favre, M.; Wyndham, E.; Chuaqui, H.

    2012-01-01

    Plasma series resonance (PSR) effect is well known in geometrically asymmetric capacitively couple radio frequency plasma. However, plasma series resonance effect in geometrically symmetric plasma has not been properly investigated. In this work, a theoretical approach is made to investigate the plasma series resonance effect and its influence on Ohmic and stochastic heating in geometrically symmetric discharge. Electrical asymmetry effect by means of dual frequency voltage waveform is applied to excite the plasma series resonance. The results show considerable variation in heating with phase difference between the voltage waveforms, which may be applicable in controlling the plasma parameters in such plasma.

  14. Online plasma calculator

    Science.gov (United States)

    Wisniewski, H.; Gourdain, P.-A.

    2017-10-01

    APOLLO is an online, Linux based plasma calculator. Users can input variables that correspond to their specific plasma, such as ion and electron densities, temperatures, and external magnetic fields. The system is based on a webserver where a FastCGI protocol computes key plasma parameters including frequencies, lengths, velocities, and dimensionless numbers. FastCGI was chosen to overcome security problems caused by JAVA-based plugins. The FastCGI also speeds up calculations over PHP based systems. APOLLO is built upon the WT library, which turns any web browser into a versatile, fast graphic user interface. All values with units are expressed in SI units except temperature, which is in electron-volts. SI units were chosen over cgs units because of the gradual shift to using SI units within the plasma community. APOLLO is intended to be a fast calculator that also provides the user with the proper equations used to calculate the plasma parameters. This system is intended to be used by undergraduates taking plasma courses as well as graduate students and researchers who need a quick reference calculation.

  15. Application of plasma technology for the modification of polymer and textile materials

    Directory of Open Access Journals (Sweden)

    Radetić Maja M.

    2004-01-01

    Full Text Available Plasma treatment is based on the physico-chemical changes of the material surface and as an ecologically and economically acceptable process it can be an attractive alternative to conventional modifications. The possibilities of plasma technology application to the modification of polymer and textile materials are discussed. Different specific properties of the material can be achieved by plasma cleaning, etching, functionalization or polymerization. The final effects are strongly influenced by the treatment parameters (treatment time, pressure, power, gas flow, the applied gas and nature of the material. The plasma treatment of polymers is predominantly focused on cleaning and activation of the surfaces to increase adhesion, binding, wettability, dye ability and printability. Current studies deal more with plasma polymerization where an ultra thin film of plasma polymer is deposited on the material surface and, depending on the applied monomer, different specific properties can be obtained (i.e. chemical and thermal resistance, abrasion resistance, antireflexion, water repellence, etc.. Plasma application to textiles is mostly oriented toward wool and synthetic fibres, though some studies also consider cotton, hemp, flax and silk. The main goal of plasma treatment is to impart a more hydrophilic fibre surface and accordingly increase wettability, dye ability, printability and particularly, shrink resistance in the case of wool. Recent studies have favored technical textiles, where plasma polymerization can offer a wide range of opportunities.

  16. Recent achievements of SIRGAS

    Science.gov (United States)

    Brunini, C.; Sánchez, L.

    2008-05-01

    SIRGAS is the geocentric reference system for the Americas. Its definition corresponds to the IERS International Terrestrial Reference System (ITRS) and it is realized by a regional densification of the IERS International Terrestrial Reference Frame (ITRF). The SIRGAS activities are coordinated by three working groups: SIRGAS-WGI (Reference System) is committed to establish and maintain a continental-wide geocentric reference frame within the ITRF. This objective was initially accomplished through two continental GPS campaigns in 1995 and 2000, including 58 and 184 stations, respectively. Today, it is realized by around 130 continuously operating GNSS sites, which are processed weekly by the IGS Regional Network Associate Analysis Centre for SIRGAS (IGS- RNAAC-SIR). SIRGAS-WGII (Geocentric Datum) is primarily in charged of defining the SIRGAS geodetic datum in the individual countries, which is given by the origin, orientation and scale of the SIRGAS system, and the parameters of the GRS80 ellipsoid. It is concentrating on promoting and supporting the adoption of SIRGAS in the Latin American and Caribbean countries through national densifications of the continental network. SIRGAS- WGIII (Vertical Datum) is dedicated to the definition and realization of a unified vertical reference system within a global frame. Its central purpose is to refer the geopotential numbers (or physical heights) in all countries to one and the same equipotential surface (W0), which must be globally defined. This includes also the transformation of the existing height datums into the new system. This study shows the SIRGAS achievements of the last two years.

  17. Plasma Physics Applied (New Book)

    Science.gov (United States)

    Grabbe, Crockett

    2007-03-01

    0.5cm Plasma physics applications are one of the most rapidly growing fields in engineering & applied science today. The last decade alone has seen the rapid emergence of new applications such as dusty plasmas in the semiconductor and microchip industries, and plasma TVs. In addition, this last decade saw the achievement of the 50-year Lawson breakeven condition for fusion. With new discoveries in space plasma physics and applications to spacecraft for worldwide communication and space weather, as well as new applications being discovered, this diversity is always expanding. The new book Plasma Physics Applied reviews developments in several of these areas. Chapter 1 reviews the content and its authors, and is followed by a more comprehensive review of plasma physics applications in general in Chapter 2. Plasma applications in combustion and environmental uses are presented in Chapter 3. Lightning effects in planetary magnetospheres and potential application are described in Chapter 4. The area of dusty plasmas in both industrial and space plasmas and their applications are reviewed in Chapter 5. The particular area of Coulomb clusters in dusty plasmas is presented in Chapter 6. The variety of approaches to plasma confinement in magnetic devices for fusion are laid out in Chapter 7. Finally, an overview of plasma accelerator developments and their applications are presented in Chapter 8.

  18. Nonlocal collisionless and collisional electron transport in low temperature plasmas

    Science.gov (United States)

    Kaganovich, Igor

    2009-10-01

    The purpose of the talk is to describe recent advances in nonlocal electron kinetics in low-pressure plasmas. A distinctive property of partially ionized plasmas is that such plasmas are always in a non-equilibrium state: the electrons are not in thermal equilibrium with the neutral species and ions, and the electrons are also not in thermodynamic equilibrium within their own ensemble, which results in a significant departure of the electron velocity distribution function from a Maxwellian. These non-equilibrium conditions provide considerable freedom to choose optimal plasma parameters for applications, which make gas discharge plasmas remarkable tools for a variety of plasma applications, including plasma processing, discharge lighting, plasma propulsion, particle beam sources, and nanotechnology. Typical phenomena in such discharges include nonlocal electron kinetics, nonlocal electrodynamics with collisionless electron heating, and nonlinear processes in the sheaths and in the bounded plasmas. Significant progress in understanding the interaction of electromagnetic fields with real bounded plasma created by this field and the resulting changes in the structure of the applied electromagnetic field has been one of the major achievements of the last decade in this area of research [1-3]. We show on specific examples that this progress was made possible by synergy between full scale particle-in-cell simulations, analytical models, and experiments. In collaboration with Y. Raitses, A.V. Khrabrov, Princeton Plasma Physics Laboratory, Princeton, NJ, USA; V.I. Demidov, UES, Inc., 4401 Dayton-Xenia Rd., Beavercreek, OH 45322, USA and AFRL, Wright-Patterson AFB, OH 45433, USA; and D. Sydorenko, University of Alberta, Edmonton, Canada. [4pt] [1] D. Sydorenko, A. Smolyakov, I. Kaganovich, and Y. Raitses, IEEE Trans. Plasma Science 34, 895 (2006); Phys. Plasmas 13, 014501 (2006); 14 013508 (2007); 15, 053506 (2008). [0pt] [2] I. D. Kaganovich, Y. Raitses, D. Sydorenko, and

  19. Improved Si0.5Ge0.5/Si interface quality achieved by the process of low energy hydrogen plasma cleaning and investigation of interface quality with positron annihilation spectroscopy

    Science.gov (United States)

    Liao, M.-H.; Chen, C.-H.

    2013-04-01

    The Positron Annihilation Spectra (PAS), Raman, and Photoluminescence spectroscopy reveal that Si0.5Ge0.5/Si interface quality can be significantly improved by the low energy plasma cleaning process using hydrogen. In the PAS, the particularly small value of lifetime and intensity near the Si0.5Ge0.5/Si interface in the sample with the treatment indicate that the defect concentration is successfully reduced 2.25 times, respectively. Fewer defects existed in the Si0.5Ge0.5/Si interface result in the high compressive strain about 0.36% in the top epi-Si0.5Ge0.5 layer, which can be observed in Raman spectra and stronger radiative recombination rate about 1.39 times for the infrared emission, which can be observed in the photoluminescence spectra. With better Si0.5Ge0.5/Si interface quality, the SiGe-based devices can have better optical and electrical characteristics for more applications in the industry. The PAS is also demonstrated that it is the useful methodology tool to quantify the defect information in the SiGe-based material.

  20. Convective plasma stability consistent with MHD equilibrium in magnetic confinement systems with a decreasing field

    International Nuclear Information System (INIS)

    Tsventoukh, M. M.

    2010-01-01

    A study is made of the convective (interchange, or flute) plasma stability consistent with equilibrium in magnetic confinement systems with a magnetic field decreasing outward and large curvature of magnetic field lines. Algorithms are developed which calculate convective plasma stability from the Kruskal-Oberman kinetic criterion and in which the convective stability is iteratively consistent with MHD equilibrium for a given pressure and a given type of anisotropy in actual magnetic geometry. Vacuum and equilibrium convectively stable configurations in systems with a decreasing, highly curved magnetic field are calculated. It is shown that, in convectively stable equilibrium, the possibility of achieving high plasma pressures in the central region is restricted either by the expansion of the separatrix (when there are large regions of a weak magnetic field) or by the filamentation of the gradient plasma current (when there are small regions of a weak magnetic field, in which case the pressure drops mainly near the separatrix). It is found that, from the standpoint of equilibrium and of the onset of nonpotential ballooning modes, a kinetic description of convective stability yields better plasma confinement parameters in systems with a decreasing, highly curved magnetic field than a simpler MHD model and makes it possible to substantially improve the confinement parameters for a given type of anisotropy. For the Magnetor experimental compact device, the maximum central pressure consistent with equilibrium and stability is calculated to be as high as β ∼ 30%. It is shown that, for the anisotropy of the distribution function that is typical of a background ECR plasma, the limiting pressure gradient is about two times steeper than that for an isotropic plasma. From a practical point of view, the possibility is demonstrated of achieving better confinement parameters of a hot collisionless plasma in systems with a decreasing, highly curved magnetic field than those

  1. Hollow laser plasma self-confined microjet generation

    Science.gov (United States)

    Sizyuk, Valeryi; Hassanein, Ahmed; CenterMaterials under Extreme Environment Team

    2017-10-01

    Hollow laser beam produced plasma (LPP) devices are being used for the generation of the self-confined cumulative microjet. Most important place by this LPP device construction is achieving of an annular distribution of the laser beam intensity by spot. An integrated model is being developed to detailed simulation of the plasma generation and evolution inside the laser beam channel. The model describes in two temperature approximation hydrodynamic processes in plasma, laser absorption processes, heat conduction, and radiation energy transport. The total variation diminishing scheme in the Lax-Friedrich formulation for the description of plasma hydrodynamic is used. Laser absorption and radiation transport models on the base of Monte Carlo method are being developed. Heat conduction part on the implicit scheme with sparse matrixes using is realized. The developed models are being integrated into HEIGHTS-LPP computer simulation package. The integrated modeling of the hollow beam laser plasma generation showed the self-confinement and acceleration of the plasma microjet inside the laser channel. It was found dependence of the microjet parameters including radiation emission on the hole and beam radiuses ratio. This work is supported by the National Science Foundation, PIRE project.

  2. Axisymmetric magnetic mirrors for plasma confinement. Recent development and perspectives

    International Nuclear Information System (INIS)

    Kruglyakov, E.P.; Dimov, G.I.; Ivanov, A.A.; Koidan, V.S.

    2003-01-01

    Mirrors are the only one class of fusion systems which completely differs topologically from the systems with closed magnetic configurations. At present, three modern types of different mirror machines for plasma confinement and heating exist in Novosibirsk (Gas Dynamic Trap,- GDT, Multi-mirror,- GOL-3, and Tandem Mirror,- AMBAL-M). All these systems are attractive from the engineering point of view because of very simple axisymmetric geometry of magnetic configurations. In the present paper, the status of different confinement systems is presented. The experiments most crucial for the mirror concept are described such as a demonstration of different principles of suppression of electron heat conductivity (GDT, GOL-3), finding of MHD stable regimes of plasma confinement in axisymmetric geometry of magnetic field (GDT, AMBAL-M), an effective heating of a dense plasma by relativistic electron beam (GOL-3), observation of radial diffusion of quiescent plasma with practically classical diffusion coefficient (AMBAL-M), etc. It should be mentioned that on the basis of the GDT it is possible to make a very important intermediate step. Using 'warm' plasma and oblique injection of fast atoms of D and T one can create a powerful 14 MeV neutron source with a moderate irradiation area (about 1 square meter) and, accordingly, with low tritium consumption. The main plasma parameters achieved are presented and the future perspectives of different mirror machines are outlined. (author)

  3. Advanced plasma flow simulations of cathodic-arc and ferroelectric plasma sources for neutralized drift compression experiments

    Directory of Open Access Journals (Sweden)

    Adam B. Sefkow

    2008-07-01

    Full Text Available Large-space-scale and long-time-scale plasma flow simulations are executed in order to study the spatial and temporal evolution of plasma parameters for two types of plasma sources used in the neutralized drift compression experiment (NDCX. The results help assess the charge neutralization conditions for ion beam compression experiments and can be employed in more sophisticated simulations, which previously neglected the dynamical evolution of the plasma. Three-dimensional simulations of a filtered cathodic-arc plasma source show the coupling efficiency of the plasma flow from the source to the drift region depends on geometrical factors. The nonuniform magnetic topology complicates the well-known general analytical considerations for evaluating guiding-center drifts, and particle-in-cell simulations provide a self-consistent evaluation of the physics in an otherwise challenging scenario. Plasma flow profiles of a ferroelectric plasma source demonstrate that the densities required for longitudinal compression experiments involving ion beams are provided over the drift length, and are in good agreement with measurements. Simulations involving azimuthally asymmetric plasma creation conditions show that symmetric profiles are nevertheless achieved at the time of peak on-axis plasma density. Also, the ferroelectric plasma expands upstream on the thermal expansion time scale, and therefore avoids the possibility of penetration into the acceleration gap and transport sections, where partial neutralization would increase the beam emittance. Future experiments on NDCX will investigate the transverse focusing of an axially compressing intense charge bunch to a sub-mm spot size with coincident focal planes using a strong final-focus solenoid. In order to fill a multi-tesla solenoid with the necessary high-density plasma for beam charge neutralization, the simulations predict that supersonically injected plasma from the low-field region will penetrate and

  4. Plasma formation in TBR

    International Nuclear Information System (INIS)

    Del Bosco, E.

    1981-01-01

    In this work are presented and discussed results of the formation and equilibrium of the plasma current in TBR, a small tokamak, designed and contructed at the Instituto de Fisica of Universidade de Sao Paulo. The measured breakdown curves for H 2 , A and He are compared with the predictions of a simple model with reasonable agreement. The influence of stray magnetic fields in the plasma formation is investigated and conditions are chosen to facilitate the breakdown. The time profile of loop voltage and plasma current for shots with plasma equilibrium are shown. A comparison is made between experimental results and analytical-numerical model for tokamaks discharges with ohmic heating. Reasonable agreement is obtained when Z, effective atomic number, is assumed as a parameter. (Author) [pt

  5. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  6. Bomb parameters

    International Nuclear Information System (INIS)

    Kerr, George D.; Young, Rebert W.; Cullings, Harry M.; Christry, Robert F.

    2005-01-01

    The reconstruction of neutron and gamma-ray doses at Hiroshima and Nagasaki begins with a determination of the parameters describing the explosion. The calculations of the air transported radiation fields and survivor doses from the Hiroshima and Nagasaki bombs require knowledge of a variety of parameters related to the explosions. These various parameters include the heading of the bomber when the bomb was released, the epicenters of the explosions, the bomb yields, and the tilt of the bombs at time of explosion. The epicenter of a bomb is the explosion point in air that is specified in terms of a burst height and a hypocenter (or the point on the ground directly below the epicenter of the explosion). The current reassessment refines the energy yield and burst height for the Hiroshima bomb, as well as the locations of the Hiroshima and Nagasaki hypocenters on the modern city maps used in the analysis of the activation data for neutrons and TLD data for gamma rays. (J.P.N.)

  7. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  8. Plasma chromatography

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This book examines the fundamental theory and various applications of ion mobility spectroscopy. Plasma chromatography developed from research on the diffusion and mobility of ions. Topics considered include instrument design and description (e.g., performance, spectral interpretation, sample handling, mass spectrometry), the role of ion mobility in plasma chromatography (e.g., kinetic theory of ion transport), atmospheric pressure ionization (e.g., rate equations), the characterization of isomers by plasma chromatography (e.g., molecular ion characteristics, polynuclear aromatics), plasma chromatography as a gas chromatographic detection method (e.g., qualitative analysis, continuous mobility monitoring, quantitative analysis), the analysis of toxic vapors by plasma chromatography (e.g., plasma chromatograph calibration, instrument control and data processing), the analysis of semiconductor devices and microelectronic packages by plasma chromatography/mass spectroscopy (e.g., analysis of organic surface contaminants, analysis of water in sealed electronic packages), and instrument design and automation (hardware, software)

  9. BIBLIOGRAPHY ON ACHIEVEMENT.

    Science.gov (United States)

    Harvard Univ., Cambridge, MA. Graduate School of Education.

    THIS BIBLIOGRAPHY LISTS MATERIAL ON VARIOUS ASPECTS OF ACHIEVEMENT. APPROXIMATELY 40 UNANNOTATED REFERENCES ARE PROVIDED TO DOCUMENTS DATING FROM 1952 TO 1965. JOURNALS, BOOKS, AND REPORT MATERIALS ARE LISTED. SUBJECT AREAS INCLUDED ARE BEHAVIOR TESTS, ACHIEVEMENT BEHAVIOR, ACADEMIC ACHIEVEMENT, AND SOCIAL-CLASS BACKGROUND. A RELATED REPORT IS ED…

  10. Spectroscopic diagnostics of industrial plasmas

    International Nuclear Information System (INIS)

    Joshi, N.K.

    2004-01-01

    Plasmas play key role in modern industry and are being used for processing micro electronic circuits to the destruction of toxic waste. Characterization of industrial plasmas which includes both 'thermal plasmas' and non-equilibrium plasmas or 'cold plasmas' in industrial environment offers quite a challenge. Numerous diagnostic techniques have been developed for the measurement of these partially ionized plasma and/or particulate parameters. The 'simple' non-invasive spectroscopic methods for characterization of industrial plasmas will be discussed in detail in this paper. The excitation temperature in thermal (DC/RF) plasma jets has been determined using atomic Boltzmann technique. The central axis temperature of thermal plasma jets in a spray torch can be determined using modified atomic Boltzmann technique with out using Abel inversion. The Stark broadening of H β and Ar-I (430 nm) lines have been used to determine the electron number density in thermal plasma jets. In low-pressure non-equilibrium argon plasma, electron temperature has been measured using the Corona model from the ratio of line intensities of atomic and ionic transitions. (author)

  11. Microwave plasma for hydrogen production from liquids

    Directory of Open Access Journals (Sweden)

    Czylkowski Dariusz

    2016-06-01

    Full Text Available The hydrogen production by conversion of liquid compounds containing hydrogen was investigated experimentally. The waveguide-supplied metal cylinder-based microwave plasma source (MPS operated at frequency of 915 MHz at atmospheric pressure was used. The decomposition of ethanol, isopropanol and kerosene was performed employing plasma dry reforming process. The liquid was introduced into the plasma in the form of vapour. The amount of vapour ranged from 0.4 to 2.4 kg/h. Carbon dioxide with the flow rate ranged from 1200 to 2700 NL/h was used as a working gas. The absorbed microwave power was up to 6 kW. The effect of absorbed microwave power, liquid composition, liquid flow rate and working gas fl ow rate was analysed. All these parameters have a clear influence on the hydrogen production efficiency, which was described with such parameters as the hydrogen production rate [NL(H2/h] and the energy yield of hydrogen production [NL(H2/kWh]. The best achieved experimental results showed that the hydrogen production rate was up to 1116 NL(H2/h and the energy yield was 223 NL(H2 per kWh of absorbed microwave energy. The results were obtained in the case of isopropanol dry reforming. The presented catalyst-free microwave plasma method can be adapted for hydrogen production not only from ethanol, isopropanol and kerosene, but also from different other liquid compounds containing hydrogen, like gasoline, heavy oils and biofuels.

  12. A global study of the unmet need for glycemic control and predictor factors among patients with type 2 diabetes mellitus who have achieved optimal fasting plasma glucose control on basal insulin.

    Science.gov (United States)

    Raccah, Denis; Chou, Engels; Colagiuri, Stephen; Gaàl, Zsolt; Lavalle, Fernando; Mkrtumyan, Ashot; Nikonova, Elena; Tentolouris, Nikolaos; Vidal, Josep; Davies, Melanie

    2017-03-01

    This study used data from different sources to identify the extent of the unmet need for postprandial glycemic control in patients with type 2 diabetes mellitus (T2DM) after the initiation of basal insulin therapy in Europe, Asia Pacific, the United States, and Latin America. Different levels of evidence were used as available for each country/region, with data extracted from seven randomized controlled trials (RCTs), three clinical trial registries (CTRs), and three electronic medical record (EMR) databases. Glycemic status was categorized as "well controlled" (glycated hemoglobin [HbA 1c ] at target [130/140 mg/dL, depending on country-specific recommendations]), or "uncontrolled" (both FPG and HbA 1c above target). Predictor factors were identified from the RCT data set using logistic regression analysis. RCT data showed that 16.9% to 28.0%, 42.7% to 54.4%, and 16.9% to 38.1% of patients with T2DM had well-controlled glycemia, residual hyperglycemia, and uncontrolled hyperglycemia, respectively. In CTRs, respective ranges were 21.8% to 33.6%, 31.5% to 35.6%, and 30.7% to 46.8%, and in EMR databases were 4.4% to 21.0%, 23.9% to 31.8%, and 53.6% to 63.8%. Significant predictor factors of residual hyperglycemia identified from RCT data included high baseline HbA 1c (all countries/regions except Brazil), high baseline FPG (United Kingdom/Japan), longer duration of diabetes (Brazil), and female sex (Europe/Latin America). Irrespective of intrinsic differences between data sources, 24% to 54% of patients with T2DM globally had residual hyperglycemia with HbA 1c not at target, despite achieving FPG control, indicating a significant unmet need for postprandial glycemic control. © 2016 The Authors. Diabetes/Metabolism Research and Reviews published by John Wiley & Sons Ltd.

  13. Expanding plasma jet in a vacuum vessel

    International Nuclear Information System (INIS)

    Chutov, Yu.I.; Kravchenko, A.Yu.; Yakovetskij, V.S.

    1998-01-01

    The paper deals with numerical calculations of parameters of a supersonic quasi-neutral argon plasma jet expanding into a cylindrical vacuum vessel and interacting with its inner surface. A modified method of large particles was used, the complex set of hydrodynamic equations being broken into simpler components, each of which describes a separate physical process. Spatial distributions of the main parameters of the argon plasma jet were simulated at various times after the jet entering the vacuum vessel, the parameters being the jet velocity field, the full plasma pressure, the electron temperature, the temperature of heavy particles, and the degree of ionization. The results show a significant effect of plasma jet interaction on the plasma parameters. The jet interaction with the vessel walls may result e.g. in excitation of shock waves and rotational plasma motions. (J.U.)

  14. Experimental works in plasma developed in INPE (Brazil). 1. Double plasma machine for longitudinal wave study. 2. Plasma centrifuge

    International Nuclear Information System (INIS)

    Ferreira, J.L.; Ludwig, G.O.; Del Bosco, E.

    1982-01-01

    This work describes some experiments done at the Plasma Physics Laboratory at INPE. In the first part, the double plasma machine used for the study of ion acoustic wave propagation is described, and the results obtained so far are shown. The second part consists in the description of a plasma centrifuge project. It contains some basic parameters of our apparatus used for isotope separation, throuth electromagtnetic rotation of the plasma. (Author) [pt

  15. Coupling of Plasmas and Liquids

    Science.gov (United States)

    Lindsay, Alexander David

    Plasma-liquids have exciting applications to several important socioeconomic areas, including agriculture, water treatment, and medicine. To realize their application potential, the basic physical and chemical phenomena of plasma-liquid systems must be better understood. Additionally, system designs must be optimized in order to maximize fluxes of critical plasma species to the liquid phase. With objectives to increase understanding of these systems and optimize their applications, we have performed both comprehensive modeling and experimental work. To date, models of plasma-liquids have focused on configurations where diffusion is the dominant transport process in both gas and liquid phases. However, convection plays a key role in many popular plasma source designs, including jets, corona discharges, and torches. In this dissertation, we model momentum, heat, and neutral species mass transfer in a convection-dominated system based on a corona discharge. We show that evaporative cooling produced by gas-phase convection can lead to a significant difference between gas and liquid phase bulk temperatures. Additionally, convection induced in the liquid phase by the gas phase flow substantially increases interfacial mass transfer of hydrophobic species like NO and NO2. Finally, liquid kinetic modeling suggests that concentrations of highly reactive species like OH and ONOOH are several orders of magnitude higher at the interface than in the solution bulk. Subsequent modeling has focused on coupling discharge physics with species transport at and through the interface. An assumption commonly seen in the literature is that interfacial loss coefficients of charged species like electrons are equal to unity. However, there is no experimental evidence to either deny or support this assumption. Without knowing the true interfacial behavior of electrons, we have explored the effects on key plasma-liquid variables of varying interfacial parameters like the electron and energy

  16. Plasma physics aspects of ETF/INTOR

    International Nuclear Information System (INIS)

    Peng, Y.K.M.; Rutherford, P.R.; Schmidt, J.A.; Cohn, D.R.; Miller, R.L.

    1980-01-01

    In order to achieve their principle technical objectives, the Engineering Test Facility (ETF) and the International Tokomak Reactor (INTOR) will require an ignited (or near ignited) plasma, sustained for pulse lengths of at least 100 secs at a high enough plasma pressure to provide a neutron wall loading of at least 1.3 MW/m 2 . The ignited plasma will have to be substantially free of impurities. Our current understanding of major plasma physics characters is summarized

  17. Atomic and molecular processes in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Janev, R.K. [International Atomic Energy Agency, Vienna (Austria)

    1997-01-01

    The role of atomic and molecular processes in achieving and maintaining the conditions for thermonuclear burn in a magnetically confined fusion plasma is described. Emphasis is given to the energy balance and power and particle exhaust issues. The most important atomic and molecular processes which affect the radiation losses and impurity transport in the core plasma, the neutral particle transport in the plasma edge and the radiative cooling of divertor plasmas are discussed in greater detail. (author)

  18. Effect of low-frequency power on dual-frequency capacitively coupled plasmas

    International Nuclear Information System (INIS)

    Yuan, Q H; Xin, Y; Huang, X J; Sun, K; Ning, Z Y; Yin, G Q

    2008-01-01

    In low-pressure dual-frequency capacitively coupled plasmas driven with 60/13.56 MHz, the effect of low-frequency power on the plasma characteristics was investigated using a compensated Langmuir electrostatic probe. At lower pressures (about 10 mTorr), it was possible to control the plasma density and the ion bombardment energy independently. As the pressure increased, this independent control could not be achieved. As the low-frequency power increased for the fixed high-frequency power, the electron energy probability function (EEPF) changed from Druyvesteyn-like to Maxwellian-like at pressures of 50 mTorr and higher, along with a drop in electron temperature. The plasma parameters were calculated and compared with simulation results.

  19. Princeton Plasma Physics Laboratory annual report, October 1, 1991--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    This report discusses the following topics: Principal parameters achieved in experimental devices for fiscal year 1992; tokamak fusion test reactor; princeton beta experiment-modification; current drive experiment-upgrade; tokamak physics experiment/steady-state advanced tokamak; international thermonuclear experimental reactor; international collaboration; x-ray laser studies; plasma processing: Deposition and etching of thin films; pure electron plasma experiments; theoretical studies; tokamak modeling; high-field magnet project; engineering department; environment, safety, and health and quality assurance; technology transfer; office of human resources and administration; PPPL invention disclosures for fiscal year 1992; office of resource management; graduate education: plasma physics; graduate education: program in plasma science and technology; and science education program.

  20. Princeton Plasma Physics Laboratory annual report, October 1, 1991--September 30, 1992

    International Nuclear Information System (INIS)

    1992-01-01

    This report discusses the following topics: Principal parameters achieved in experimental devices for fiscal year 1992; tokamak fusion test reactor; princeton beta experiment-modification; current drive experiment-upgrade; tokamak physics experiment/steady-state advanced tokamak; international thermonuclear experimental reactor; international collaboration; x-ray laser studies; plasma processing: Deposition and etching of thin films; pure electron plasma experiments; theoretical studies; tokamak modeling; high-field magnet project; engineering department; environment, safety, and health and quality assurance; technology transfer; office of human resources and administration; PPPL invention disclosures for fiscal year 1992; office of resource management; graduate education: plasma physics; graduate education: program in plasma science and technology; and science education program