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Sample records for bottle plasma flows

  1. Fast magnetic and electric dynamos in flat Klein bottle plasma flows

    CERN Document Server

    de Andrade, L C Garcia

    2009-01-01

    Recently Shukurov et al [Phys Rev \\textbf{E} (2008)] presented a numerical solution of a Moebius strip dynamo flow, to investigate its use in modelling dynamo flows in Perm torus of liquid sodium dynamo experiments. Here, by analogy one presents an electric dynamo on a twisted torus or Klein bottle topology. An exact solution in the form of flat Klein bottle dynamo flow is obtained. It is shown that even in the absence of magnetic dynamos initial electric fields can be amplified in distinct points of the Klein bottle. In this case diffusion is taken as ${\\eta}\\approx{5.0{\\times}10^{-3}{\\Omega}-m}$ the electric potential is obtained. The difference of electric fields at the beginning of plasma flow profile is ${\\Delta}E_{Dyn}\\approx{468\\frac{V}{m}}$, which is stronger than the electric dynamo field obtained in the magnetic axis of spheromaks, which is of the order of $E_{Dyn}\\approx{200\\frac{V}{m}}$. The potential of the dynamo at the surface of the Earth computed by Boozer [Phys Fluids \\textbf{B} (1993)] of $...

  2. Analysis of plasma and neutral gas flow inside of a PET bottle under PIII condition by particle-in-cell/Monte Carlo simulation

    International Nuclear Information System (INIS)

    The plasma behavior inside of a PET bottle has been simulated under the condition of plasma immersed ion implantation and deposition (PIII and D) using the simulation software 'PEGASUS'. The software uses the 'PIC-MCCM' module for the plasma analysis and the 'DSMCM' module for the gas flow field analysis. DSMCM gives densities, velocities, fluxes, temperatures and pressures of each neutral species such as the fed gas species and radicals. By coupling PIC-MCCM with DSMCM simulation, the plasma behavior in the flowing Ar gas and N2 gas has been simulated. The gas was injected from the tip of the gas inlet which was inserted into the center of the bottle. The base gas pressure was 1-50Pa and a positive pulse voltage (maximum voltage=0.1-1kV) was applied to the center rod. A two-dimensional cylindrical coordinate system was used. Time evolution of the spacial distribution was obtained for densities of electrons, N2+ ions, N2* radicals and N atoms in N2 gas, and Ar+ ions, Ar* and Ar*(4s) radicals in Ar gas. Time evolution of the particle flux and the energy flux of electrons and ions on the target surface was also obtained

  3. Fluid dynamics following flow shut-off in bottle filling

    Science.gov (United States)

    Thete, Sumeet; Appathurai, Santosh; Gao, Haijing; Basaran, Osman

    2012-11-01

    Bottle filling is ubiquitous in industry. Examples include filling of bottles with shampoos and cleaners, engine oil and pharmaceuticals. In these examples, fluid flows out of a nozzle to fill bottles in an assembly line. Once the required volume of fluid has flowed out of the nozzle, the flow is shut off. However, an evolving fluid thread or string may remain suspended from the nozzle following flow shut-off and persist. This stringing phenomenon can be detrimental to a bottle filling operation because it can adversely affect line speed and filling accuracy by causing uncertainty in fill volume, product loss and undesirable marring of the bottles' exterior surfaces. The dynamics of stringing are studied numerically primarily by using the 1D, slender-jet approximation of the flow equations. A novel feature entails development and use of a new boundary condition downstream of the nozzle exit to expedite the computations. While the emphasis is on stringing of Newtonian fluids and use of 1D approximations, results will also be presented for situations where (a) the fluids are non-Newtonian and (b) the full set of equations are solved without invoking the 1D approximation. Phase diagrams will be presented that identify conditions for which stringing can be problematic.

  4. Pin-Hole Water Flow from Cylindrical Bottles

    OpenAIRE

    de Oliveira, P. M. C.; Delfino, A.; Costa, E. V.; Leite, C. A. F.

    2000-01-01

    We performed an experiment on elementary hydrodynamics. The basic system is a cylindrical bottle from which water flows through a pin-hole located at the bottom of its lateral surface. We measured the speed of the water leaving the pin-hole, as a function of both the time and the current level of water still inside the bottle. The experimental results are compared with the theory. The theoretical treatment is a very simple one based on mass and energy conservation, corresponding to a widespre...

  5. Plasma sterilization of polyethylene terephthalate bottles by pulsed corona discharge at atmospheric pressure.

    Science.gov (United States)

    Masaoka, Satoshi

    2007-06-01

    A pulsed power supply was used to generate a corona discharge on a polyethylene terephthalate bottle, to conduct plasma sterilization at atmospheric pressure. Before generating such a discharge, minute quantities of water were attached to the inner surface of the bottle and to the surface of a high voltage (HV) electrode inserted into the bottle. Next, high-voltage pulses of electricity were discharged between electrodes for 6.0s, while rotating the bottle. The resulting spore log reduction values of Bacillus subtilis and Aspergillus niger on the inner surface of the bottle were 5.5 and 6 or higher, respectively, and those on the HV electrode surface were each 6 or higher for both strains. The presence of the by-products gaseous ozone, hydrogen peroxide, and nitric ions resulting from the electrical discharge was confirmed. PMID:17629247

  6. Quadratically integrable geodesic flows on the torus and on the Klein bottle

    OpenAIRE

    Matveev, V. S.

    1997-01-01

    In the present paper we prove, that if the geodesic flow of a metric G on the torus T is quadratically integrable, then the torus T isometrically covers a torus with a Liouville metric on it, and describe the set of quadratically integrable geodesic flows on the Klein bottle.

  7. Simultaneous Sterilization With Surface Modification Of Plastic Bottle By Plasma-Based Ion Implantation

    Science.gov (United States)

    Sakudo, N.; Ikenaga, N.; Ikeda, F.; Nakayama, Y.; Kishi, Y.; Yajima, Z.

    2011-01-01

    Dry sterilization of polymeric material is developed. The technique utilizes the plasma-based ion implantation which is same as for surface modification of polymers. Experimental data for sterilization are obtained by using spores of Bacillus subtilis as samples. On the other hand we previously showed that the surface modification enhanced the gas barrier characteristics of plastic bottles. Comparing the implantation conditions for the sterilization experiment with those for the surface modification, we find that both sterilization and surface modification are simultaneously performed in a certain range of implantation conditions. This implies that the present bottling system for plastic vessels will be simplified and streamlined by excluding the toxic peroxide water that has been used in the traditional sterilization processes.

  8. Permeation barrier coating and plasma sterilization of PET bottles and foils

    Science.gov (United States)

    Steves, Simon; Deilmann, Michael; Bibinov, Nikita; Awakowicz, Peter

    2009-10-01

    Modern packaging materials such as polyethylene terephthalate (PET) offer various advantages over glass or metal containers. Beside this they only offer poor barrier properties against gas permeation. Therefore, the shelf-live of packaged food is reduced. Additionally, common sterilization methods like heat, hydrogen peroxide or peracetic acid may not be applicable due to reduced heat or chemical resistance of the plastic packaging material. For the plasma sterilization and permeation barrier coating of PET bottles and foils, a microwave driven low pressure plasma reactor is developed based on a modified Plasmaline antenna. The dependencies of important plasma parameters, such as gas mixture, process pressure, power and pulse conditions on oxygen permeation through packaging foil are investigated. A residual permeation as low as J = 1.0 ±0.3 cm^3m-2day-1bar-1 for 60 nm thick silicon oxide (SiOx) coated PET foils is achieved. To discuss this residual permeation, coating defects are visualized by capacitively coupled atomic oxygen plasma etching of coated substrate. A defect density of 3000 mm-2 is revealed responsible for permeation. For plasma sterilization, optimized plasma parameters based on fundamental research of plasma sterilization mechanisms permit short treatment times of a few seconds.

  9. Determination of Arsenic and Other Trace Elements in Bottled Waters by High Resolution Inductively Coupled Plasma Mass Spectrometry

    OpenAIRE

    Fiket, Željka; ROJE, Vibor; Mikac, Nevenka; Kniewald, Goran

    2007-01-01

    Concentrations of arsenic and other trace elements in 18 different brands of bottled, mineral and spring, water in Croatia were investigated. For comparison, samples of tap water from Rijeka, Lourdes and Zagreb were also analyzed. The high resolution inductively coupled plasma mass spectrometry (HR ICP-MS) was used for the analysis. Results obtained were compared to Croatian maximum allowable levels for trace elements in drinking, mineral and tap water, as well as WHO and EPA drinking water s...

  10. Couette Flow of Unmagnetized Plasma

    CERN Document Server

    Collins, C; Cooper, C M; Flanagan, K; Khalzov, I V; Nornberg, M D; Seidlitz, B; Wallace, J; Forest, C B

    2014-01-01

    Differentially rotating flows of unmagnetized, highly conducting plasmas have been created in the Plasma Couette Experiment. Previously, hot-cathodes have been used to control plasma rotation by a stirring technique [C. Collins et al., Phys. Rev. Lett. 108, 115001(2012)] on the outer cylindrical boundary---these plasmas were nearly rigid rotors, modified only by the presence of a neutral particle drag. Experiments have now been extended to include stirring from an inner boundary, allowing for generalized Couette flow and opening a path for both hydrodynamic and magnetohydrodynamic experiments, as well as fundamental studies of plasma viscosity. Plasma is confined in a cylindrical, axisymmetric, multicusp magnetic field, with $T_e< 10$ eV, $T_i<1$ eV, and $n_e<10^{11}$ cm$^{-3}$. Azimuthal flows (up to 12 km/s, $M=V/c_s\\sim 0.7$) are driven by edge ${\\bf J \\times B}$ torques in helium, neon, argon, and xenon plasmas. We present measurements of a self-consistent, rotation-induced, species-dependent rad...

  11. Bluff Body Flow Control Using Plasma Actuators

    Science.gov (United States)

    Thomas, Flint

    2005-11-01

    In this study, the use of single dielectric barrier discharge plasma actuators for the control of bluff body flow separation is investigated. In particular, surface mounted plasma actuators are used to reduce both drag and unsteady vortex shedding from circular cylinders in cross-flow. It is demonstrated that the plasma-induced surface blowing gives rise to a local Coanda effect that promotes the maintenance of flow attachment. Large reductions in vortex shedding and drag are demonstrated for Reynolds numbers ˜ 10^410^5. Both steady and unsteady plasma-induced surface blowing is explored. Results are presented from experiments involving both two and four surface mounted actuators.

  12. Miniature magnetic bottle confined by circularly polarized laser light and measurements of the inverse Faraday effect in plasmas

    International Nuclear Information System (INIS)

    A new concept of hot plasma confinement in a miniature magnetic bottle induced by circularly polarized laser light is suggested. Magnetic fields generated by circularly polarized laser light may be of the order of megagauss, depending on the laser intensity. In this configuration the circularly polarized light is used to obtain confinement of a plasma contained in a good conductor vessel. The confinement in this scheme is supported by the magnetic forces. The Lawson criterion for a DT plasma might be achieved for number density n = 5*1021 cm-3 and confinement time τ= 20 ns. The laser and plasma parameters required to obtain an energetic gain are calculated. Experiments and preliminary calculations were performed to study the feasibility of the above scheme. Measurements of the axial magnetic field induced by circularly polarized laser light, the so called inverse Faraday effect, and of the absorption of circularly polarized laser light in plasma, are reported. The experiments were performed with a circularly polarized Nd:YAG laser, having a wavelength of 1.06 τm and a pulse duration of 7 ns, in a range of irradiances from 109 to 1014 W/cm2. Axial magnetic fields from 500 Gauss to 2 megagauss were measured. Up to 5*1013 W/cm3 the results are in agreement with a nonlinear model of the inverse Faraday effect dominated by the ponderomotive force. For the laser irradiance studied here, 9*1013 - 2.5*1014 W/cm2, the absorption of circularly polarized light was 14% higher relative to the absorption of linear polarized light

  13. Taylor-Couette Flow of Unmagnetized Plasma

    OpenAIRE

    Collins, C.; Clark, M; Cooper, C. M.; Flanagan, K; Khalzov, I. V.; Nornberg, M. D.; Seidlitz, B.; Wallace, J; Forest, C. B.

    2014-01-01

    Differentially rotating flows of unmagnetized, highly conducting plasmas have been created in the Plasma Couette Experiment. Previously, hot-cathodes have been used to control plasma rotation by a stirring technique [C. Collins et al., Phys. Rev. Lett. 108, 115001(2012)] on the outer cylindrical boundary---these plasmas were nearly rigid rotors, modified only by the presence of a neutral particle drag. Experiments have now been extended to include stirring from an inner boundary, allowing for...

  14. A topological analysis of plasma flow structures

    International Nuclear Information System (INIS)

    A new topological analysis of the plasma flow structures is presented for some pressure-gradient-driven turbulence results. The analysis is done by separating the structures into radial layers and studying each layer separately. This allows for the identification of flow cycles and flow filaments and the determination of the life of the cycles and length of the filaments. (paper)

  15. Cylinder Flow Control Using Plasma Actuators

    Science.gov (United States)

    Kozlov, Alexey; Thomas, Flint

    2007-11-01

    In this study the results of flow control experiments utilizing single dielectric barrier discharge plasma actuators to control flow separation and unsteady vortex shedding from a circular cylinder in cross-flow are reported. Two optimized quartz dielectric plasma actuators mounted on the cylinder surface utilizing an improved saw-tooth waveform high-voltage generator allowed flow control at Reynolds number approaching supercritical. Using either steady or unsteady actuation, it is demonstrated that the plasma-induced surface blowing gives rise to a local Coanda effect that promotes the maintenance of flow attachment. PIV based flow fields and wake velocity profiles obtained with hot-wire anemometry show large reductions in vortex shedding, wake width and turbulence intensity.

  16. Non-equilibrium in flowing atmospheric plasmas

    International Nuclear Information System (INIS)

    This thesis deals with the fundamental aspects of two different plasmas applied in technological processes. The first one is the cesium seeded argon plasma in a closed cycle Magnetohydrodynamic (MHD) generator, the second is the thermal argon plasma in a cascade arc with an imposed flow. In Chapter 2 the influence of non-equilibrium on the mass and energy balances of a plasma is worked out. The general theory presented there can be applied to both the plasma in an MHD generator and to the cascade arc with imposed flow. Introductions to these plasmas are given in the Chapters 3 and 6 respectively. These chapters are both followed by two chapters which treat the theoretical and the experimental investigations. The results are summarized in Chapter 9. (Auth.)

  17. FLUIDS, PLASMAS AND ELECTRIC DISCHARGES: The influence of the structures and compounds of DLC coatings on the barrier properties of PET bottles

    Science.gov (United States)

    Yang, Li; Wang, Zhen-Duo; Zhang, Shou-Ye; Yang, Li-Zhen; Chen, Qiang

    2009-12-01

    To reduce the oxygen transmission rate through a polyethylene terephthalate (PET) bottle (an organic plastic) diamond-like carbon (DLC) coatings on the inner surface of the PET bottle were deposited by radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) technology with C2H2 as the source of carbon and Ar as the diluted gas. As the barrier layer to humidity and gas permeation, this paper analyses the DLC film structure, composition, morphology and barrier properties by Fourier transform infrared, atomic force microscopy, scanning electron microscopy and oxygen transmission rate in detail. From the spectrum, it is found that the DLC film mainly consists of sp3 bonds. The barrier property of the films is significantly relevant to the sp3 bond concentration in the coating, the film thickness and morphology. Additionally, it is found that DLC film deposited in an inductively coupled plasma enhanced capacitively coupled plasma source shows a compact, homogeneous and crack-free surface, which is beneficial for a good gas barrier property in PET bottles.

  18. Magnetron source of accelerated plasma flow

    Science.gov (United States)

    Veresov, L. P.; Veresov, O. L.

    2016-01-01

    A new source of an accelerated plasma flow intended for depositing high-quality coatings is described. In this source, a magnetron discharge for cathode target sputtering is combined with a high-voltage discharge with longitudinal oscillation of electrons for ionization of the accrued vapor in which the plasma density is distributed uniformly owing to the application of three-phase ionizer.

  19. Drying of oxygen humidifier bottles with heated air-flow%热气流烘干法用于氧气湿化瓶干燥

    Institute of Scientific and Technical Information of China (English)

    李惜珍; 林佳玲; 黄丽侬

    2011-01-01

    Objective To explore the feasibility of drying oxygen humidifier bottles by using air-flow dryer for glass apparatus. Methods A total of 120 oxygen humidifier bottles recycled from the wards were randomized into a control group of 30 and an air-flow group of 90. All the bottles were disinfected and then rinsed with running water. The bottles in the control group were placed on racks with the opening of the bottles downwards and dried naturally. The bottles in the air-flow group were placed on the heating bars of the air-flow dryer for glass apparatus, and the heating temparatures were adjusted to 46-55℃ for the first batch, 56-65℃ for the sedcond batch, and 66-75℃ for the third batch respectively, with each batch having 30 bottles. Results It took 24 h for the control group to dry completely, and it took 1.5 h, 1.0 h and 0.5 h respectively for the first, second and third batch of the air-flow group to dry. However, 56.7% of the 3rd batch bottles became out of shape. After drying, all the bottles were sealed for storage,and on the 5th and 7th storage day, the air-flow group had higher rates of negative results of bacterial culture than the control group did (P<0. 05,P<0. 01). Conclusion Drying length of oxygen humidifier bottles can be shortened by staff's using air-flow dryer for glass apparatus which guarantees the disinfection effect.%目的 探讨玻璃仪器气流烘干器用于干燥氧气湿化瓶的实用性和可行性.方法 将从病房回收的氧气温化瓶120个随机分为自然晾干组30个,烘干器烘干组(下称烘干组)90个.统一消毒冲洗干净后,自然晾干组湿化瓶倒置插于晾干架上,在室温下晾干;烘干组分3批各30个分别选用46~55℃、56~65℃、66~75℃倒置插于烘干器上烘干.结果 自然晾干组干燥所需时间24 h;烘干组46~55℃、56~65℃、66~75℃3个温度档干燥所需时间分别为1.5 h、1.0 h、0.5 h,但后者变形率达56.7%;干燥密封包装后第5、7天

  20. Plasma flow in peripheral region of detached plasma in linear plasma device

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y., E-mail: hayashi-yuki13@ees.nagoya-u.ac.jp; Ohno, N. [Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Kajita, S. [EcoTopia Science Institute, Nagoya University, Nagoya, Aichi 464-8603 (Japan); Tanaka, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan)

    2016-01-15

    A plasma flow structure is investigated using a Mach probe under detached plasma condition in a linear plasma device NAGDIS-II. A reverse flow along the magnetic field is observed in a steady-state at far-peripheral region of the plasma column in the upstream side from the recombination front. These experimental results indicate that plasma near the recombination front should strongly diffuse across the magnetic field, and it should be transported along the magnetic field in the reverse flow direction. Furthermore, bursty plasma density fluctuations associated with intermittent convective plasma transport are observed in the far-peripheral region of the plasma column in both upstream and downstream sides from the recombination front. Such a nondiffusive transport can contribute to the intermittent reverse plasma flow, and the experimental results indicate that intermittent transports are frequently produced near the recombination front.

  1. Plasma flow in peripheral region of detached plasma in linear plasma device

    International Nuclear Information System (INIS)

    A plasma flow structure is investigated using a Mach probe under detached plasma condition in a linear plasma device NAGDIS-II. A reverse flow along the magnetic field is observed in a steady-state at far-peripheral region of the plasma column in the upstream side from the recombination front. These experimental results indicate that plasma near the recombination front should strongly diffuse across the magnetic field, and it should be transported along the magnetic field in the reverse flow direction. Furthermore, bursty plasma density fluctuations associated with intermittent convective plasma transport are observed in the far-peripheral region of the plasma column in both upstream and downstream sides from the recombination front. Such a nondiffusive transport can contribute to the intermittent reverse plasma flow, and the experimental results indicate that intermittent transports are frequently produced near the recombination front

  2. Plasma flow in peripheral region of detached plasma in linear plasma device

    Science.gov (United States)

    Hayashi, Y.; Ohno, N.; Kajita, S.; Tanaka, H.

    2016-01-01

    A plasma flow structure is investigated using a Mach probe under detached plasma condition in a linear plasma device NAGDIS-II. A reverse flow along the magnetic field is observed in a steady-state at far-peripheral region of the plasma column in the upstream side from the recombination front. These experimental results indicate that plasma near the recombination front should strongly diffuse across the magnetic field, and it should be transported along the magnetic field in the reverse flow direction. Furthermore, bursty plasma density fluctuations associated with intermittent convective plasma transport are observed in the far-peripheral region of the plasma column in both upstream and downstream sides from the recombination front. Such a nondiffusive transport can contribute to the intermittent reverse plasma flow, and the experimental results indicate that intermittent transports are frequently produced near the recombination front.

  3. Magnetic field generation by circularly polarized laser light and inertial plasma confinement in a miniature 'Magnetic Bottle' induced by circularly polarized laser light

    International Nuclear Information System (INIS)

    A new concept of hot plasma confinement in a miniature magnetic bottle induced by circularly polarized laser light is suggested in this work. Magnetic fields generated by circularly polarized laser light may be of the order of megagauss. In this configuration the circularly polarized laser light is used to get confinement of a plasma contained in a good conductor vessel. The poloidal magnetic field induced by the circularly polarized laser and the efficiency of laser absorption by the plasma are calculated in this work. The confinement in this scheme is supported by the magnetic forces and the Lawson criterion for a DT plasma might be achieved for number density n=5*1021 cm-3 and confinement time τ= 20 nsec. The laser and the plasma parameters required to get an energetic gain are calculated. (authors)

  4. Super-paramagnetic nanoparticles synthesis in a thermal plasma reactor assisted by magnetic bottle

    Science.gov (United States)

    Cartaya, R.; Puerta, J.; Martín, P.

    2015-03-01

    The present work is a study of the synthesis of super-paramagnetic particles. A preliminary study based on thermodynamic diagrams of Gibbs free energy minimization, was performed with the CSIRO Thermochemical System. In this way, the synthesis of magnetite nanoparticles from precursor powder of ore iron in a thermal reactor, was performed. Then the process was simulated mathematically using magnetohydrodynamic and kinetic equations, in order to predict the synthesis process. A cylindrical reactor assisted by magnetic mirrors was used. The peak intensity of 0.1 tesla (1000 Gauss) was measured at the end of the solenoid. A PlazjetTM 105/15 thermal plasma torch was used. The precursor powder was iron oxide and the plasma gas, nitrogen. The magnetite powder was magnetized whit rare-earth super-magnets, alloy of neodymium-iron boron (NdFeB) grade N-42. The synthesized nanoparticles diameters was measured with a scanning electron microscope LECO and the permanent magnetization with a YOKOGAWA gauss meter, model 325i. Our experimental results show that it is possible the synthesis of super-paramagnetic nanoparticles in thermal plasma reactors.

  5. Plasma Flow in a Theta Pinch

    International Nuclear Information System (INIS)

    In the absence of instabilities, the loss of plasma in a theta pinch is almost wholly due to flow along the magnetic field to the ends of the coil. Thus, in order to understand the containment of the plasma, it is necessary to study the transient axial flow of the plasma. This is done in the present work by setting up a simple model of the plasma in which the problem is reduced to that of studying a one-dimensional flow. Initially a similarity area-wave is propagated from the open ends. The properties of this wave and the resulting loss are calculated. For high-β plasmas the plasma is lost rapidly behind the wave-front. However, the wave-front itself propagates very slowly and the resulting loss is consequently small. In these conditions the loss is approximately equal to that of the corresponding steady flow. For lower values of β the loss is much less than in the steady flow. When the rarefaction waves from the two ends reach the centre of the pinch they are reflected. The trajectory of the reflected wave is determined as a function of β and wave profiles calculated by numerical integration of the equations are presented. The flow may be reduced by applying increased fields at the ends of the pinch. In this case a rarefaction wave is propagated from these ''mirrors'', but behind the wave there is a region of uniform flow. This flow pattern is described and the resulting loss rate calculated. (author)

  6. Precursor solitons in a flowing complex plasma

    Science.gov (United States)

    Bandyopadhyay, Pintu; Jaiswal, Surabhi; Sen, Abhijit

    2015-11-01

    We report the first experimental observation of precursor solitons in a flowing dusty plasma. The nonlinear solitary dust acoustic waves (DAWs) are excited by a supersonic mass flow of the dust particles passing over an electrostatic potential hill. In a frame where the fluid is stationary and the hill is moving the solitons propagate in the upstream direction while wake structures consisting of linear DAWs are seen to propagate in the downstream direction. The experiments have been carried out in a U-shaped Dusty Plasma Experimental (DPEx) device where kaolin particles are immersed in a DC discharge argon plasma to form the dusty plasma and a floating wire mounted on the cathode creates a potential hill. The dust flow is induced by sudden changes in the hill height and the solitary structures are seen only for supersonic flows and up to an upper limit of the flow. A theoretical model description of the phenomenon will be provided and some practical implications of such precursor excitations for a charged object moving in a plasma will be discussed.

  7. Bottled Water and Fluoride

    Science.gov (United States)

    ... Fluoridation Journal Articles for Community Water Fluoridation Bottled Water Recommend on Facebook Tweet Share Compartir Consumers drink ... questions about bottled water and fluoride. Does bottled water contain fluoride? Bottled water products may contain fluoride, ...

  8. Quasisymmetric toroidal plasmas with large mean flows

    International Nuclear Information System (INIS)

    Geometric condition for quasisymmetric toroidal plasmas with large mean flows on the order of the ion thermal speed are investigated. Equilibrium momentum balance equations including the inertia term due to the large flow velocity are used to show that, for rotating quasisymmetic plasmas with no local currents crossing flux surfaces, all components of the metric tensor should be independent of the toroidal angle in the Boozer coordinates, and consequently these systems need to be rigorously axisymmetric. Unless the local radial currents vanish, the Boozer coordinates do not exist and the toroidal flow velocity cannot take any value other than a very limited class of eigenvalues corresponding to very rapid rotation especially for low beta plasmas. (author)

  9. Plasma flow measurements with Mach probe

    International Nuclear Information System (INIS)

    A Mach probe is studied as a simple method to measure the plasma flow velocity (Mach number) along magnetic field lines. The probe was located behind the separator, which is movable along the field line, to avoid a recycling-like phenomenon that occurs owing to the plasma striking the separator. From the ratio of ion currents to the probe with to without the separator, the Mach number was deduced by applying a theory proposed by Chung. Even though the theory is not necessarily satisfactory for approximation of the viscosity term in fluid equations, the Mach number obtained from the Mach probe is compared fairly well with the real Mach number which was obtained from dispersion relations of the shear Alfven wave drifting along or against the plasma flow. (author)

  10. Flowing dusty plasma experiments: Generation of flow and measurement techniques

    CERN Document Server

    Jaiswal, S; Sen, A

    2016-01-01

    A variety of experimental techniques for the generation of subsonic/supersonic dust fluid flows and means of measuring such flow velocities are presented. The experiments have been carried out in a $\\Pi-$shaped Dusty Plasma Experimental (DPEx) device with micron size kaolin/Melamine Formaldehyde (MF) particles embedded in a background of Argon plasma created by a direct current (DC) glow discharge. A stationary dust cloud is formed over the cathode region by precisely balancing the pumping speed and gas flow rate. A flow of dust particles/fluid is generated by additional gas injection from a single or dual locations or by altering the dust confining potential. The flow velocity is then estimated by three different techniques, namely, by super Particle Identification (sPIT) code, Particle Image Velocimetry (PIV) analysis and the excitation of Dust Acoustic Waves (DAWs). The results obtained from these three different techniques along with their merits and demerits are discussed. An estimation of the neutral dr...

  11. Flow Parameters of Argon plasma Discharge

    International Nuclear Information System (INIS)

    Owing to the viscosity, the plasma will be adhering to the inner surface of the outer electrode and outer surface of the inner one. As result that the discharge will be eroding the walls of coaxial system. The thickness of the boundary layer near the walls has been estimated at different positions from the breech of coaxial plasma gun. It is found that the thickness of layer 0.008 cm at the end of inner electrode (17 cm). A coaxial plasma gun device is operated in argon gas at ambient pressure 0.6 Torr and discharge voltage about 10 KV. The electron temperature of argon discharge has been determined by using spectroscopic technique. It is found that kTe=3.4 eV. By knowing the thickness of the boundary layer, the density can be determined. The Reynolds number R=105 and Mach number M=5 i.e. the flow is compressible and hypersonic

  12. Plasma actuators for bluff body flow control

    Science.gov (United States)

    Kozlov, Alexey V.

    The aerodynamic plasma actuators have shown to be efficient flow control devices in various applications. In this study the results of flow control experiments utilizing single dielectric barrier discharge plasma actuators to control flow separation and unsteady vortex shedding from a circular cylinder in cross-flow are reported. This work is motivated by the need to reduce landing gear noise for commercial transport aircraft via an effective streamlining created by the actuators. The experiments are performed at Re D = 20,000...164,000. Circular cylinders in cross-flow are chosen for study since they represent a generic flow geometry that is similar in all essential aspects to a landing gear oleo or strut. The minimization of the unsteady flow separation from the models and associated large-scale wake vorticity by using actuators reduces the radiated aerodynamic noise. Using either steady or unsteady actuation at ReD = 25,000, Karman shedding is totally eliminated, turbulence levels in the wake decrease significantly and near-field sound pressure levels are reduced by 13.3 dB. Unsteady actuation at an excitation frequency of St D = 1 is found to be most effective. The unsteady actuation also has the advantage that total suppression of shedding is achieved for a duty cycle of only 25%. However, since unsteady actuation is associated with an unsteady body force and produces a tone at the actuation frequency, steady actuation is more suitable for noise control applications. Two actuation strategies are used at ReD = 82,000: spanwise and streamwise oriented actuators. Near field microphone measurements in an anechoic wind tunnel and detailed study of the near wake using LDA are presented in the study. Both spanwise and streamwise actuators give nearly the same noise reduction level of 11.2 dB and 14.2 dB, respectively, and similar changes in the wake velocity profiles. The contribution of the actuator induced noise is found to be small compared to the natural shedding

  13. Explosive plasma flows in a solar flare

    Science.gov (United States)

    Zarro, Dominic M.; Canfield, Richard C.; Metcalf, Thomas R.; Strong, Keith T.

    1988-01-01

    Solar Maximum Mission soft X-ray data and Sacramento Peak Observatory H-alpha observations are combined in a study of the impulsive phase of a solar flare. A blue asymmetry, indicative of upflows, was observed in the coronal Ca XIX line during the soft X-ray rise phase. A red asymmetry, indicative of downflows, was observed simultaneously in chromospheric H-alpha emitted from bright flare kernels during the period of hard X-ray emission. Combining the velocity data with a measurement of coronal electron density, it is shown that the impulsive phase momentum of upflowing soft X-ray-emitting plasma equalled that of the downflowing H-alpha-emitting plasma to within one order of magnitude. In particular, the momentum of the upflowing plasma was 2 x 10 to the 21st g cm/s while that of the downflowing plasma was 7 x 10 to the 21st g cm/s, with a factor of 2 uncertainty on each value. This equality supports the explosive chromospheric evaporation model of solar flares, in which a sudden pressure increase at the footprint of a coronal loop produces oppositely directed flows in the heated plasma.

  14. Liberty Bottle or Liability Bottle?

    OpenAIRE

    Livingstone, Verity

    1988-01-01

    The number of mothers initiating breastfeeding has increased dramatically over the last decade but the percentage of mothers who terminate breastfeeding prematurely has remained constant. When mothers experience difficulty with breastfeeding, many physicians fail to diagnose and manage the problem effectively. Some physicians assume that mothers dislike breastfeeding and, in a misguided attempt to help, recommend the introduction of a bottle to solve the problem. They do not explain to the mo...

  15. Multi-Scale Investigation of Sheared Flows In Magnetized Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Edward, Thomas [Auburn Univ., Auburn, AL (United States)

    2014-09-19

    Flows parallel and perpendicular to magnetic fields in a plasma are important phenomena in many areas of plasma science research. The presence of these spatially inhomogeneous flows is often associated with the stability of the plasma. In fusion plasmas, these sheared flows can be stabilizing while in space plasmas, these sheared flows can be destabilizing. Because of this, there is broad interest in understanding the coupling between plasma stability and plasma flows. This research project has engaged in a study of the plasma response to spatially inhomogeneous plasma flows using three different experimental devices: the Auburn Linear Experiment for Instability Studies (ALEXIS) and the Compact Toroidal Hybrid (CTH) stellarator devices at Auburn University, and the Space Plasma Simulation Chamber (SPSC) at the Naval Research Laboratory. This work has shown that there is a commonality of the plasma response to sheared flows across a wide range of plasma parameters and magnetic field geometries. The goal of this multi-device, multi-scale project is to understand how sheared flows established by the same underlying physical mechanisms lead to different plasma responses in fusion, laboratory, and space plasmas.

  16. Acceleration and Focusing of Plasma Flows

    Science.gov (United States)

    Griswold, Martin E.

    The acceleration of flowing plasmas is a fundamental problem that is useful in a wide variety of technological applications. We consider the problem from the perspective of plasma propulsion. Gridded ion thrusters and Hall thrusters are the most commonly used devices to create flowing plasma for space propulsion, but both suffer from fundamental limitations. Gridded ion sources create good quality beams in terms of energy spread and spatial divergence, but the Child-Langmuir law in the non-neutral acceleration region limits the maximum achievable current density. Hall thrusters avoid this limitation by accelerating ions in quasi-neutral plasma but, as a result, produce plumes with high spatial divergence and large energy spread. In addition the more complicated magnetized plasma in the Hall Thruster produces oscillations that can reduce the efficiency of the thruster by increasing electron transport to the anode. We present investigations of three techniques to address the fundamental limitations on the performance of each thruster. First, we propose a method to increase the time-averaged current density (and thus thrust density) produced by a gridded ion source above the Child-Langmuir limit by introducing time-varying boundary conditions. Next, we use an electrostatic plasma lens to focus the Hall thruster plume, and finally we develop a technique to suppress a prominent oscillation that degrades the performance of Hall thrusters. The technique to loosen the constraints on current density from gridded ion thrusters actually applies much more broadly to any space charge limited flow. We investigate the technique with a numerical simulation and by proving a theoretical upper bound. While we ultimately conclude that the approach is not suitable for space propulsion, our results proved useful in another area, providing a benchmark for research into the spontaneously time-dependent current that arises in microdiodes. Next, we experimentally demonstrate a novel

  17. Investigation of dielectric barrier discharge plasma flow control

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Effects of plasma flow control are researched on the basis of plasma exciting flow experiments and numerical simulations. Turbulent model is more effective than laminar model in plasma numerical simulation as results showed. Both plasma exciting effects of acceleration and flow separation suppression are investigated through experiments carried on the flat plate and the compressor cascades. The results demonstrate that boundary layer characteristic is modified by plasma exciting. Distributions of total pressure and velocity in the wake are improved notably for 20 m/s coming velocity and the effect of plasma can still be observed while velocity is increased to 50 m/s. For low velocity flow, plasma exciting is effective in flow separation suppression.

  18. Anisotropic plasma with flows in tokamak: Steady state and stability

    International Nuclear Information System (INIS)

    An adequate description of equilibrium and stability of anisotropic plasma with macroscopic flows in tokamaks is presented. The Chew-Goldberger-Low (CGL) approximation is consistently used to analyze anisotropic plasma dynamics. The admissible structure of a stationary flow is found to be the same as in the ideal magnetohydrodynamics with isotropic pressure (MHD), which means an allowance for the same relabeling symmetry as in ideal MHD systems with toroidally nested magnetic surfaces. A generalization of the Grad-Shafranov equation for the case of anisotropic plasma with flows confined in the axisymmetric magnetic field is derived. A variational principle was obtained, which allows for a stability analysis of anisotropic pressure plasma with flows, and takes into account the conservation laws resulting from the relabeling symmetry. This principle covers the previous stability criteria for static CGL plasma and for ideal MHD flows in isotropic plasma as well. copyright 1996 American Institute of Physics

  19. The beam-plasma interaction in the symmetrically opened plasma system with contrastreaming electron flows

    International Nuclear Information System (INIS)

    The beam-plasma interaction in the symmetrically opened plasma system with the plasma penetrating in vacuum along magnetic field in presence of the contratreaming electron flow is investigated. It is found that the contrastreaming electron flow component, that is formed by secondary electron-electron emissions from the collector, effects substantially on the oscillations in the system. 20 refs.; 31 figs

  20. Coupled flows and oscillations in asymmetric rotating plasmas

    International Nuclear Information System (INIS)

    Nonlinear coupling among the radial, axial, and azimuthal flows in an asymmetric cold rotating plasma is considered nonperturbatively. Exact solutions describing an expanding or contracting plasma with oscillations are then obtained. It is shown that despite the flow asymmetry the energy in the radial and axial flow components can be transferred to the azimuthal component but not the vice versa, and that flow oscillations need not be accompanied by density oscillations.

  1. HELENA code with incompressible parallel plasma flow

    Science.gov (United States)

    Throumoulopoulos, George; Poulipoulis, George; Konz, Christian; EFDA ITM-TF Team

    2015-11-01

    It has been established that plasma rotation in connection to both zonal and equilibrium flow can play a role in the transitions to the advanced confinement regimes in tokamaks, as the L-H transition and the formation of Internal Transport Barriers. For incompressible rotation the equilibrium is governed by a generalized Grad-Shafranov (GGS) equation and a decoupled Bernoulli-type equation for the pressure. For parallel flow the GGS equation can be transformed to one identical in form with the usual Grad-Shafranov equation. In the present study on the basis of the latter equation we have extended HELENA, an equilibrium fixed boundary solver integrated in the ITM-TF modeling infrastructure. The extended code solves the GGS equation for a variety of the two free-surface-function terms involved for arbitrary Afvén Mach functions. We have constructed diverted-boundary equilibria pertinent to ITER and examined their characteristics, in particular as concerns the impact of rotation. It turns out that the rotation affects noticeably the pressure and toroidal current density with the impact on the current density being stronger in the parallel direction than in the toroidal one. Also, the linear stability of the equilibria constructed is examined This work has been carried out within the framework of the EUROfuion Consortium and has received funding from the National Programme for the Controlled Thermonuclear Fusion, Hellenic Republic.

  2. Digital Image Processing in Investigations of Plasma Flow Structure

    Czech Academy of Sciences Publication Activity Database

    Chumak, Oleksiy; Hrabovský, Milan

    2011-01-01

    Roč. 39, č. 11 (2011), s. 2910-2911. ISSN 0093-3813 R&D Projects: GA TA ČR TA01010300 Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma jet * plasma flow fluctuations * image processing Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.174, year: 2011

  3. Mach Probes, Plasma Flows, and Heavy Impurity Transport in CSDX

    OpenAIRE

    Gosselin, Jordan James

    2016-01-01

    Understanding material migration in tokamaks is fundamental to understanding the problem of the lifetime of the plasma facing components in the tokamak. However, diagnostic access and plasma parameter control in tokamaks is difficult. In order to address the migration of wall material in the scrape off layer of tokamaks, parallel transport of heavy impurities in a lighter flowing plasma is studied in an Argon plasma.The device used is CSDX, a 3m long, 20 cm diameter...

  4. Simulation of Flow Around Cylinder Actuated by DBD Plasma

    Science.gov (United States)

    Wang, Yuling; Gao, Chao; Wu, Bin; Hu, Xu

    2016-07-01

    The electric-static body force model is obtained by solving Maxwell's electromagnetic equations. Based on the electro-static model, numerical modeling of flow around a cylinder with a dielectric barrier discharge (DBD) plasma effect is also presented. The flow streamlines between the numerical simulation and the particle image velocimetry (PIV) experiment are consistent. According to the numerical simulation, DBD plasma can reduce the drag coefficient and change the vortex shedding frequencies of flow around the cylinder.

  5. Effect of Energetic Plasma Flux on Flowing Liquid Lithium Surfaces

    Science.gov (United States)

    Kalathiparambil, Kishor; Jung, Soonwook; Christenson, Michael; Fiflis, Peter; Xu, Wenyu; Szott, Mathew; Ruzic, David

    2014-10-01

    An operational liquid lithium system with steady state flow driven by thermo-electric magneto-hydrodynamic force and capable of constantly refreshing the plasma exposed surface have been demonstrated at U of I. To evaluate the system performance in reactor relevant conditions, specifically to understand the effect of disruptive plasma events on the performance of the liquid metal PFCs, the setup was integrated to a pulsed plasma generator. A coaxial plasma generator drives the plasma towards a theta pinch which preferentially heats the ions, simulating ELM like flux, and the plasma is further guided towards the target chamber which houses the flowing lithium system. The effect of the incident flux is examined using diagnostic tools including triple Langmuir probe, calorimeter, rogowski coils, Ion energy analyzers, and fast frame spectral image acquisition with specific optical filters. The plasma have been well characterized and a density of ~1021 m-3, with electron temperature ~10 - 20 eV is measured, and final plasma velocities of 34 - 74 kms-1 have been observed. Calorimetric measurements using planar molybdenum targets indicate a maximum plasma energy (with 6 kV plasma gun and 20 kV theta pinch) of 0.08 MJm-2 with plasma divergence effects resulting in marginal reduction of 40 +/- 23 J in plasma energy. Further results from the other diagnostic tools, using the flowing lithium targets and the planar targets coated with lithium will be presented. DOE DE-SC0008587.

  6. Generation of zonal flows in rotating fluids and magnetized plasmas

    DEFF Research Database (Denmark)

    Juul Rasmussen, J.; Garcia, O.E.; Naulin, V.;

    2006-01-01

    The spontaneous generation of large-scale flows by the rectification of small-scale turbulent fluctuations is of great importance both in geophysical flows and in magnetically confined plasmas. These flows regulate the turbulence and may set up effective transport barriers. In the present...... contribution the generation of zonal flows will be illustrated in a simple fluid experiment performed in a rotating container with radial symmetric bottom topography. An effective mixing that homogenizes the potential vorticity in the fluid layer will lead to the replacement of the high-potential vorticity...... analogy to large-scale flow generation in drift-wave turbulence dynamics in magnetized plasma is briefly discussed....

  7. Numerical analysis of flow characteristics of an atmospheric plasma torch

    CERN Document Server

    Kim, Y J; Han, J G; Kim, Youn J.; Kim, You-Jae

    2004-01-01

    The atmospheric plasma is regarded as an effective method for surface treatments because it can reduce the period of process and does not need expensive vacuum apparatus. The performance of non-transferred plasma torches is significantly depended on jet flow characteristics out of the nozzle. In order to produce the high performance of a torch, the maximum discharge velocity near an annular gap in the torch should be maintained. Also, the compulsory swirl is being produced to gain the shape that can concentrate the plasma at the center of gas flow. Numerical analysis of two different mathematical models used for simulating plasma characteristics inside an atmospheric plasma torch is carried out. A qualitative comparison is made in this study to test the accuracy of these two different model predictions of an atmospheric plasma torch. Numerical investigations are carried out to examine the influence of different model assumptions on the resulting plasma characteristics. Significant variations in the results in...

  8. Resonant optical schlieren system for plasma flow studies

    International Nuclear Information System (INIS)

    A dye laser, pumped by ruby second harmonic radiation at 3471 A, emitting approx.5-mJ, 20-nsec pulses with a bandwidth of 0.3 A, has been developed as a light source in a schlieren optical system which utilizes enhanced refractivity to examine plasma flow phenomena. When the dye laser is tuned adjacent to the BaII ion resonance line at 4554 A, the sensitivity of the system to density gradients in a barium plasma becomes 100--1000 times greater than can be achieved with nonresonant light sources which rely on the free electron contributions to plasma refractivity. Absorption effects also yield data on plasma flow patterns

  9. Flow Simulation and Optimization of Plasma Reactors for Coal Gasification

    Institute of Scientific and Technical Information of China (English)

    冀春俊; 张英姿; 马腾才

    2003-01-01

    This paper reports a 3-d numerical simulation system to analyze the complicatedflow in plasma reactors for coal gasification, which involve complex chemical reaction, two-phaseflow and plasma effect. On the basis of analytic results, the distribution of the density, tempera-ture and components' concentration are obtained and a different plasma reactor configuration isproposed to optimize the flow parameters. The numerical simulation results show an improvedconversion ratio of the coal gasification. Different kinds of chemical reaction models are used tosimulate the complex flow inside the reactor. It can be concluded that the numerical simulationsystem can be very useful for the design and optimization of the plasma reactor.

  10. Rare gas flow structuration in plasma jet experiments

    OpenAIRE

    Robert, Éric; Sarron, Vanessa; Darny, Thibault; Riès, Delphine; Dozias, Sébastien; Fontane, Jérôme; Joly, Laurent; Pouvesle, Jean-Michel

    2014-01-01

    Modifications of rare gas flow by plasma generated with a plasma gun (PG) are evidenced through simultaneous time-resolved ICCD imaging and schlieren visualization. The geometrical features of the capillary inside which plasma propagates before in-air expansion, the pulse repetition rate and the presence of a metallic target are playing a key role on the rare gas flow at the outlet of the capillary when the plasma is switched on. In addition to the previously reported upstream offset of the l...

  11. MODELLING OF MIXING OF STEAM PLASMA JET AND COLD STEAM FLOW IN THERMAL PLASMA REACTOR

    Czech Academy of Sciences Publication Activity Database

    Hirka, Ivan; Jeništa, Jiří; Hrabovský, Milan

    Kudowa, Polsko, 2005. s. 41-42. [Fifth International Workshop and Summer School – Towards Fusion Energy, Plasma Physics, Diagnostics, Spin-offs. 6.6.2005-10.6.2005, Kudowa] Institutional research plan: CEZ:AV0Z20430508 Keywords : CFD modelling * k-.EPSILON. model * plasma flow Subject RIV: BL - Plasma and Gas Discharge Physics

  12. Shielding of absorbing objects in collisionless flowing plasma

    CERN Document Server

    Tyshetskiy, Yuriy

    2010-01-01

    The electrostatic shielding of a charged absorbing object (dust grain) in a flowing collisionless plasma is investigated by using the linearized kinetic equation for plasma ions with a point-sink term accounting for ion absorption on the object. The effect of absorption on the attractive part of the grain potential is investigated. For subthermal ion flows, the attractive part of the grain potential in the direction perpendicular to the ion flow can be significantly reduced or completely destroyed, depending on the absorption rate. For superthermal ion flows, however, the effect of absorption on the grain attraction in the direction perpendicular to the ion flow is shown to be exponentially weak. It is thus argued that, in the limit of superthermal ion flow, the effect of absorption on the grain shielding potential can be safely ignored for typical grain sizes relevant to complex plasmas.

  13. Research status of fast flows and shocks in laboratory plasmas. Critical velocities in a plasma

    International Nuclear Information System (INIS)

    An outline of critical velocities in plasma is described. The critical velocities in plasma are different with the direction of flow. When the fast flow runs along the magnetic field, the critical velocity is sound velocity in order that the flow compresses. When plasma and neutral gas coexist, the critical ionization velocity (CIV) is defined by that the relative velocity of them cannot be more than the ionization potential. When flow runs perpendicularly to the magnetic field, the critical velocity is affected by the centrifugal force. If energy dissipation is produced by ionization, the critical ionization velocity is observed. The formation mechanisms of many kinds of critical velocities are described. (S.Y.)

  14. Plasma flow discharge researches at the PIRIT-2000 facility

    International Nuclear Information System (INIS)

    Investigation of a plasma flow switch at the PIRIT-2000 fast operating capacitor bank is reported. The maximum current of the plasma flow discharge (PFD) reaches 5 MA, the current rise time being as low as 100 ns. The magnetic field strength of the plasma flow switch (0.15 T) is about 15 times higher than that of the plasma erosion switch used earlier. Both magnetic probe and optical methods were used in the experiments. From the magnetic probes data the propagating velocity of a current carrying shell (205 cm/s) has been derived, while the optical method is used for determining the velocity of a glowing plasma layer. At varying the operation delay in the range 2-10 s the PFD load current rise time increases up to 150-200 ns, the prepulse increment reaching its maximum at the delays higher than 6 s. (J.U.). 5 figs., 5 refs

  15. Plasma flow in the DIII-D divertor

    Energy Technology Data Exchange (ETDEWEB)

    Boedo, J.A. [Univ. of California, San Diego, CA (United States); Porter, G.D. [Lawrence Livermore National Lab., CA (United States); Schaffer, M.J. [General Atomics, San Diego, CA (United States)] [and others

    1998-07-01

    Indications that flows in the divertor can exhibit complex behavior have been obtained from 2-D modeling but so far remain mostly unconfirmed by experiment. An important feature of flow physics is that of flow reversal. Flow reversal has been predicted analytically and it is expected when the ionization source arising from neutral or impurity ionization in the divertor region is large, creating a high pressure zone. Plasma flows arise to equilibrate the pressure. A radiative divertor regime has been proposed in order to reduce the heat and particle fluxes to the divertor target plates. In this regime, the energy and momentum of the plasma are dissipated into neutral gas introduced in the divertor region, cooling the plasma by collisional, radiative and other atomic processes so that the plasma becomes detached from the target plates. These regimes have been the subject of extensive studies in DIII-D to evaluate their energy and particle transport properties, but only recently it has been proposed that the energy transport over large regions of the divertor must be dominated by convection instead of conduction. It is therefore important to understand the role of the plasma conditions and geometry on determining the region of convection-dominated plasma in order to properly control the heat and particle fluxes to the target plates and hence, divertor performance. The authors have observed complex structures in the deuterium ion flows in the DIII-D divertor. Features observed include reverse flow, convective flow over a large volume of the divertor and stagnant flow. They have measured large gradients in the plasma potential across the separatrix in the divertor and determined that these gradients induce poloidal flows that can potentially affect the particle balance in the divertor.

  16. Plasma flow in the DIII-D divertor

    International Nuclear Information System (INIS)

    Indications that flows in the divertor can exhibit complex behavior have been obtained from 2-D modeling but so far remain mostly unconfirmed by experiment. An important feature of flow physics is that of flow reversal. Flow reversal has been predicted analytically and it is expected when the ionization source arising from neutral or impurity ionization in the divertor region is large, creating a high pressure zone. Plasma flows arise to equilibrate the pressure. A radiative divertor regime has been proposed in order to reduce the heat and particle fluxes to the divertor target plates. In this regime, the energy and momentum of the plasma are dissipated into neutral gas introduced in the divertor region, cooling the plasma by collisional, radiative and other atomic processes so that the plasma becomes detached from the target plates. These regimes have been the subject of extensive studies in DIII-D to evaluate their energy and particle transport properties, but only recently it has been proposed that the energy transport over large regions of the divertor must be dominated by convection instead of conduction. It is therefore important to understand the role of the plasma conditions and geometry on determining the region of convection-dominated plasma in order to properly control the heat and particle fluxes to the target plates and hence, divertor performance. The authors have observed complex structures in the deuterium ion flows in the DIII-D divertor. Features observed include reverse flow, convective flow over a large volume of the divertor and stagnant flow. They have measured large gradients in the plasma potential across the separatrix in the divertor and determined that these gradients induce poloidal flows that can potentially affect the particle balance in the divertor

  17. Thin current sheets caused by plasma flow gradients in space and astrophysical plasma

    Directory of Open Access Journals (Sweden)

    D. H. Nickeler

    2010-08-01

    Full Text Available Strong gradients in plasma flows play a major role in space and astrophysical plasmas. A typical situation is that a static plasma equilibrium is surrounded by a plasma flow, which can lead to strong plasma flow gradients at the separatrices between field lines with different magnetic topologies, e.g., planetary magnetospheres, helmet streamers in the solar corona, or at the boundary between the heliosphere and interstellar medium. Within this work we make a first step to understand the influence of these flows towards the occurrence of current sheets in a stationary state situation. We concentrate here on incompressible plasma flows and 2-D equilibria, which allow us to find analytic solutions of the stationary magnetohydrodynamics equations (SMHD. First we solve the magnetohydrostatic (MHS equations with the help of a Grad-Shafranov equation and then we transform these static equilibria into a stationary state with plasma flow. We are in particular interested to study SMHD-equilibria with strong plasma flow gradients perpendicular to separatrices. We find that induced thin current sheets occur naturally in such situations. The strength of the induced currents depend on the Alfvén Mach number and its gradient, and on the magnetic field.

  18. High energy density Z-pinch plasmas using flow stabilization

    International Nuclear Information System (INIS)

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and

  19. High energy density Z-pinch plasmas using flow stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Shumlak, U., E-mail: shumlak@uw.edu; Golingo, R. P., E-mail: shumlak@uw.edu; Nelson, B. A., E-mail: shumlak@uw.edu; Bowers, C. A., E-mail: shumlak@uw.edu; Doty, S. A., E-mail: shumlak@uw.edu; Forbes, E. G., E-mail: shumlak@uw.edu; Hughes, M. C., E-mail: shumlak@uw.edu; Kim, B., E-mail: shumlak@uw.edu; Knecht, S. D., E-mail: shumlak@uw.edu; Lambert, K. K., E-mail: shumlak@uw.edu; Lowrie, W., E-mail: shumlak@uw.edu; Ross, M. P., E-mail: shumlak@uw.edu; Weed, J. R., E-mail: shumlak@uw.edu [Aerospace and Energetics Research Program, University of Washington, Seattle, Washington, 98195-2250 (United States)

    2014-12-15

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and

  20. Bluff body flow control with atmospheric plasma actuators

    OpenAIRE

    Huang, X.; Zhang, X.; Gabriel, S

    2008-01-01

    Plasma actuators operating in atmospheric air were employed to modify aerodynamic flow over a bluff body. The model consisted of a cylinder and a strut that was installed on the trailing half side of the cylinder. The objective was to reduce the broadband noise that is mainly generated by the impingment of the cylinder wake on the strut. The plasma actuators were configured to produce dielectric barrier discharges, through which the flow separation from the cylinder was enhanced. As a result ...

  1. Influence of magnetically trapped hot ions on warm plasma flowing

    International Nuclear Information System (INIS)

    Interesting and unexpected phenomenon was found on heating plasma experiments on trap open-quotes AMBAL-YUclose quotes: neutral beam injection results in decrease of target plasma density without change of its shape. The open-quotes AMBAL-YUclose quotes device is a classical mirror with minimum-B. Neutral beams injected into the trap perpendicularly to the magnetic field form hot-ion plasma. In the initial stage of hot-ion accumulation, target plasma is a plasma generated by gas-discharge source located behind the trap. Plasma penetrates into the trap along magnetic field lines. Injection leads to decrease of target plasma density (up to 2.5 times). Plasma density sudden leap moving from injection region to gas-discharge source had been observed. A considerable increase of energy of ions leaving the trap was experimentally registered. Plasma potential had been changed. It was cleared out that this effect is not explained by transversal losses of plasma or passing of momentum from beams to plasma. Rise of activity on ion cyclotron fluctuations had not been registered. The physical situation we wish to model is that of a warm plasma flowing along magnetic field lines in the presence of a magnetically trapped species of hot ions. Let us consider the plasma stream in the frames of two liquids magnetohydrodynamics. We consider the following set of momentum equations presented by Braginskiy in a slightly different form

  2. Three electrode atmospheric pressure plasma jet in helium flow

    Science.gov (United States)

    Maletic, Dejan; Puac, Nevena; Malovic, Gordana; Petrovic, Zoran Lj.

    2015-09-01

    Plasma jets are widely used in various types of applications and lately more and more in the field of plasma medicine. However, it is not only their applicability that distinguishes them from other atmospheric plasma sources, but also the behavior of the plasma. It was shown that plasma plume is not continuous, but discrete set of plasma packages. Here we present iCCD images and current voltage characteristics of a three electrode plasma jet. Our plasma jet has a simple design with body made of glass tube and two transparent electrodes wrapped around it. The additional third metal tip electrode was positioned at 10 and 25 mm in front of the jet nozzle and connected to the same potential as the powered electrode. Power transmitted to the plasma was from 0.5 W to 4.0 W and the helium flow rate was kept constant at 4 slm. For the 10 mm configuration plasma is ignited on the metal tip in the whole period of the excitation signal and in the positive half cycle plasma ``bullet'' is propagating beyond the metal tip. In contrast to that, for the 25 mm configuration at the tip electrode plasma can be seen only in the minimum and maximum of the excitation signal, and there is no plasma ``bullet'' formation. This research has been supported by the Ministry of Education, Science and Technological Development, Republic of Serbia, under projects ON171037 and III41011.

  3. Radial Plasma Flow Switch on GIT-12 Generator

    Science.gov (United States)

    Chaikovsky, S. A.; Kokshenev, V. A.; Rousskikh, A. G.; Shishlov, A. V.; Fedunin, A. V.; Labetsky, A. Yu.; Kurmaev, N. E.; Fursov, F. I.

    2006-01-01

    The preliminary experiments were performed on wire array implosion driven by a radial plasma flow switch on the GIT-12 generator operating in a microsecond mode. Imploding gas puff z-pinch plasma was used to provide fast switching of the current to an aluminum wire array. The experimental results are presented in the paper.

  4. Generalized superconducting flows -- Plasma confinement, organization

    Energy Technology Data Exchange (ETDEWEB)

    Mahajan, S.M.

    1997-01-01

    Complete expulsion of magnetic vorticity is used to characterize the superconducting flow. It is shown that a simple, intuitive, but speculative generalization can serve as a paradigm for a variety of organized flows.

  5. Effect of high-energy electrons component on recombination plasma with pulse plasma flow

    International Nuclear Information System (INIS)

    Experiments on a recombination plasma with pulse plasma flow have been performed in the linear divertor simulator TPD-SheetIV. The pulse plasma flow was generated using a switching circuit controlled by the electric potential of the adjacent floating electrode in the plasma source. The duration of the pulse was 0.3 ms at a frequency of 50 Hz. The time dependence of the electron density ne, temperature Te, and energy distribution function fe(E) were measured using a Langmuir probe. The ionization and recombination events are analyzed using the Collisional-Radiative model, taking into account high-energy electrons. (author)

  6. Axisymmetric equilibria with pressure anisotropy and plasma flow

    CERN Document Server

    Evangelias, A

    2016-01-01

    A generalised Grad-Shafranov equation that governs the equilibrium of an axisymmetric toroidal plasma with anisotropic pressure and incompressible flow of arbitrary direction is derived. This equation includes six free surface functions and recovers known Grad-Shafranov-like equations in the literature as well as the usual static, isotropic one. The form of the generalised equation indicates that pressure anisotropy and flow act additively on equilibrium. In addition, two sets of analytical solutions, an extended Solovev one with a plasma reaching the separatrix and an extended Hernegger-Maschke one for a plasma surrounded by a fixed boundary possessing an X-point, are constructed, particularly in relevance to the ITER and NSTX tokamaks. Furthermore, the impacts both of pressure anisotropy and plasma flow on these equilibria are examined. It turns out that depending on the maximum value and the shape of an anisotropy function, the anisotropy can act either paramagnetically or diamagnetically. Also, in most of...

  7. Axisymmetric equilibria with pressure anisotropy and plasma flow

    CERN Document Server

    Evangelias, Achilleas

    2016-01-01

    In this Master thesis we investigate the influence of pressure anisotropy and incompressible flow of arbitrary direction on the equilibrium properties of magnetically confined, axisymmetric toroidal plasmas. The main novel contribution is the derivation of a pertinent generalised Grad-Shafranov equation. This equation includes six free surface functions and recovers known Grad-Shafranov-like equations in the literature as well as the usual static, isotropic one. The form of the generalised equation indicates that pressure anisotropy and flow act additively on equilibrium. In addition, two sets of analytical solutions, an extended Solovev one with a plasma reaching the separatrix and an extended Hernegger-Maschke one for a plasma surrounded by a fixed boundary possessing an X-point, are constructed, particularly in relevance to the ITER and NSTX tokamaks. Furthermore, the impacts both of pressure anisotropy, through an anisotropy function assumed to be uniform on the magnetic surfaces, and plasma flow, via the...

  8. Analysis by modeling of plasma flow interactions with liquid injection

    International Nuclear Information System (INIS)

    This paper deals with the modeling of different plasma flows interacting with a liquid jet of pure water. Using only fluid mechanic equations, the goal was to simulate and to understand the first moments of these interactions during suspension plasma spraying of nano-materials. The obtained simulations were then validated by comparing the results with breakup mechanisms described for the same Weber number in a plasma cross flow with constant temperature. The global model was applied to various suspension plasma spraying conditions: two plasma gas mixtures (Ar/H2 and Ar/He) and two types of liquid injections (train of droplets or continuous jet). These simulations demonstrated different trajectories of the liquid and, consequently, different modes of breakup. Droplet size distributions were also calculated in the global modeling field. (authors)

  9. Standing sausage modes in coronal loops with plasma flow

    CERN Document Server

    Li, Bo; Xia, Li-Dong; Yu, Hui

    2014-01-01

    Magnetohydrodynamic waves are important for diagnosing the physical parameters of coronal plasmas. Field-aligned flows appear frequently in coronal loops.We examine the effects of transverse density and plasma flow structuring on standing sausage modes trapped in coronal loops, and examine their observational implications. We model coronal loops as straight cold cylinders with plasma flow embedded in a static corona. An eigen-value problem governing propagating sausage waves is formulated, its solutions used to construct standing modes. Two transverse profiles are distinguished, one being the generalized Epstein distribution (profile E) and the other (N) proposed recently in Nakariakov et al.(2012). A parameter study is performed on the dependence of the maximum period $P_\\mathrm{max}$ and cutoff length-to-radius ratio $(L/a)_{\\mathrm{cutoff}}$ in the trapped regime on the density parameters ($\\rho_0/\\rho_\\infty$ and profile steepness $p$) and flow parameters (magnitude $U_0$ and profile steepness $u$). For e...

  10. Effect of toroidal plasma flow and flow shear on global MHD modes

    International Nuclear Information System (INIS)

    The effect of a subsonic toroidal flow on the linear magnetohydrodynamic stability of a tokamak plasma surrounded by an external resistive wall is studied. A complex non-self-adjoint eigenvalue problem for the stability of general kink and tearing modes is formulated, solved numerically, and applied to high β tokamaks. Results indicate that toroidal plasma flow, in conjunction with dissipation in the plasma, can open a window of stability for the position of the external wall. In this window, stable plasma beta values can significantly exceed those predicted by the Troyon scaling law with no wall. Computations utilizing experimental data indicate good agreement with observations

  11. Plasma flow in the near and distant geomagnetic tail

    International Nuclear Information System (INIS)

    Measurements of the bulk flow of plasma in the outer magnetosphere were first made a little over a decade ago with Los Alamos instruments on the Vela satellites. During the invervening years, as flow measurements have been made with improved instruments and by other satellites they have come to play a crucial role in the development of our understanding of the structure and dynamics of the magnetosphere. For example, they were the means of discovery of the magnetosphere's boundary layer and of plasma vortices within the plasma sheet. They were the essential ingredient in the identification of signatures of magnetic reconnection at the magnetopause. And they were indispensable in clarifying the complex phenomena in the magnetotail accompanying substorms and in showing that these phenomena are consistent with a substorm model involving magnetic reconnection at a near-earth neutral line. Most recently, magnetotail plasma flow measurements by the ISEE-3 satellite at distances as great as 230 R/sub E/ have been instrumental in fixing the average location of the distant neutral line at approx. 60 to 120 R/sub E/ and in identifying plasmoids (i.e., severed sections of the plasma sheet), released during substorms and escaping down-tail. This paper reviews the features of magnetotail plasma flow, describes the most recent observations, and discusses their implications for magnetospheric physics

  12. Plasma Control of Turbine Secondary Flows Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose Phase I and II efforts that will focus on turbomachinery flow control. Specifically, the present work will investigate active control in a high speed...

  13. Evolution of plasma flow shear and stability in the ZaP flow Z-pinch

    International Nuclear Information System (INIS)

    Full text: The ZaP Flow Z-pinch experiment at the University of Washington investigates the concept of using sheared flows to stabilize an otherwise unstable plasma configuration. The stabilizing effect of a sheared axial flow on the m = 1 kink instability in Z-pinches has been studied using linearized, ideal MHD theory to reveal that a sheared axial flow stabilizes the kink mode when the shear exceeds a threshold. The ZaP experiment generates a Z-pinch plasma that is 1 m long with a 1 cm radius with an embedded axial flow. Time-resolved Doppler shifts of plasma impurity lines are measured along 20 chords to determine the plasma axial velocity profiles. An azimuthal array of magnetic probes measures the fluctuation levels of the azimuthal modes m = 1, 2, and 3. After pinch assembly a quiescent period is found where the mode activity is significantly reduced. The plasma axial velocity evolves from a uniform to a sheared and back to a uniform flow profile. The sheared flow profile is coincident with a plasma quiescent period where magnetic mode fluctuations are low. The value of the velocity shear satisfies the theoretical threshold for stability during the quiescent period and does not satisfy the threshold during high mode activity. (author)

  14. Flow induced dust acoustic shock waves in a complex plasma

    Science.gov (United States)

    Jaiswal, Surabhi; Bandyopadhyay, Pintu; Sen, Abhijit

    2015-11-01

    We report on experimental observations of particle flow induced large amplitude shock waves in a dusty plasma. These dust acoustic shocks (DAS) are observed for strongly supersonic flows and have been studied in a U-shaped Dusty Plasma Experimental (DPEx) device for charged kaolin dust in a background of Argon plasma. The strong flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change of the dust density near the potential hill is used to trigger the onset of high velocity dust acoustic shocks. The dynamics of the shocks are captured by fast video pictures of the structures that are illuminated by a laser sheet beam. The physical characteristics of the shock are delineated from a parametric scan of their dynamical properties over a range of plasma parameters and flow speeds. Details of these observations and a physical explanation based on model calculations will be presented.

  15. Fast measurement of picoamp plasma flows using trapped electron clouds

    OpenAIRE

    Kabantsev, A A; Driscoll, C F

    2004-01-01

    We demonstrate that magnetized electron clouds can diagnose picoamp ion currents (or equivalent neutralized plasma flows) on a kHz time scale. This could be used to measure the dynamics of neutral plasma losses to the walls, e.g., along divertor field lines. In essence, a current passing through an electron cloud in a Penning trap transfers angular momentum to the cloud, driving an easily measured orbital "diocotron" instability (from ion currents) or orbital damping (from electron currents)....

  16. Plasma flow measurements in a simulated low earth orbit plasma

    International Nuclear Information System (INIS)

    The employment of large, higher power solar arrays for space operation has been considered, taking into account a utilization of high operating voltages. In connection with the consideration of such arrays, attention must be given to the fact that the ambient environment of space contains a tenuous low energy plasma which can interact with the high voltage array causing power 'leakage' and arcing. An investigation has been conducted with the aim to simulate the behavior of such an array in low-earth-orbit (LEO). During the experiments, local concentrations of the 'leakage' current were observed when the panel was at a high voltage. These concentrations could overload or damage a small area of cells in a large string. It was hypothesized that this effect was produced by electrostatic focusing of the particles by the sheath fields. To verify this experimentally, an end-effect Langmuir probe was employed. The obtained results are discussed

  17. Dusty Plasma Experimental (DPEx) device for complex plasma experiments with flow

    CERN Document Server

    Jaiswal, S; Sen, A

    2015-01-01

    A versatile table-top dusty plasma experimental device (DPEx) to study flow induced excitations of linear and nonlinear waves/structures in a complex plasma is presented. In this $\\Pi$-shaped apparatus a DC glow discharge plasma is produced between a disc shaped anode and a grounded long cathode tray by applying a high voltage DC in the background of a neutral gas and subsequently a dusty plasma is created by introducing micron sized dust particles that get charged and levitated in the sheath region. A flow of the dust particles is induced in a controlled manner by adjusting the pumping speed and the gas flow rate into the device. A full characterisation of the plasma, using Langmuir and emissive probe data, and that of the dusty plasma using particle tracking data with the help of an idl based (super) Particle Identification and Tracking (sPIT) code is reported. Experimental results on the variation of the dust flow velocity as a function of the neutral pressure and the gas flow rate are given. The potential...

  18. Thomson scattering measurements from asymmetric interpenetrating plasma flows

    International Nuclear Information System (INIS)

    Imaging Thomson scattering measurements of collective ion-acoustic fluctuations have been utilized to determine ion temperature and density from laser produced counter-streaming asymmetric flows. Two foils are heated with 8 laser beams each, 500 J per beam, at the Omega Laser facility. Measurements are made 4 mm from the foil surface using a 60 J 2ω probe laser with a 200 ps pulse length. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the multi-ion species, asymmetric flows theoretical form factor for the ion feature such that the ion temperatures, ion densities, and flow velocities for each plasma flow are determined

  19. Thomson scattering measurements from asymmetric interpenetrating plasma flows

    Energy Technology Data Exchange (ETDEWEB)

    Ross, J. S., E-mail: ross36@llnl.gov; Moody, J. D.; Fiuza, F.; Ryutov, D.; Divol, L.; Huntington, C. M.; Park, H.-S. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-11-15

    Imaging Thomson scattering measurements of collective ion-acoustic fluctuations have been utilized to determine ion temperature and density from laser produced counter-streaming asymmetric flows. Two foils are heated with 8 laser beams each, 500 J per beam, at the Omega Laser facility. Measurements are made 4 mm from the foil surface using a 60 J 2ω probe laser with a 200 ps pulse length. Measuring the electron density and temperature from the electron-plasma fluctuations constrains the fit of the multi-ion species, asymmetric flows theoretical form factor for the ion feature such that the ion temperatures, ion densities, and flow velocities for each plasma flow are determined.

  20. Axisymmetric equilibria with pressure anisotropy and plasma flow

    Science.gov (United States)

    Evangelias, A.; Throumoulopoulos, G. N.

    2016-04-01

    A generalised Grad-Shafranov equation that governs the equilibrium of an axisymmetric toroidal plasma with anisotropic pressure and incompressible flow of arbitrary direction is derived. This equation includes six free surface functions and recovers known Grad-Shafranov-like equations in the literature as well as the usual static, isotropic one. The form of the generalised equation indicates that pressure anisotropy and flow act additively on equilibrium. In addition, two sets of analytical solutions, an extended Solovev one with a plasma reaching the separatrix and an extended Hernegger-Maschke one for a plasma surrounded by a fixed boundary possessing an X-point, are constructed, particularly in relevance to the ITER and NSTX tokamaks. Furthermore, the impacts both of pressure anisotropy and plasma flow on these equilibria are examined. It turns out that depending on the maximum value and the shape of an anisotropy function, the anisotropy can act either paramagnetically or diamagnetically. Also, in most of the cases considered both the anisotropy and the flow have stronger effects on NSTX equilibria than on ITER ones.

  1. Focusing of plasma flow in an E cross B discharge

    Science.gov (United States)

    Griswold, Martin; Raitses, Yevgeny; Fisch, Nathaniel J.

    2010-11-01

    ExB discharges can be used to accelerate ions in a quasi-neutral plasma. Large ion fluxes can be produced in this way because there is no space charge limitation, however difficulty in specifying the electric field distribution results in large flow divergence [1]. Recent work has identified new methods to control the flow divergence [2,3]. We present the results of new techniques that are designed to further reduce the divergence. [4pt] [1] A.I. Morozov and V.V. Savelyev, Reviews of Plasma Physics vol. 21, B. B. Kadomtsev and V. D. Shafranov, Eds. New York: Consultants Bureau, 2000. [2] Y. Raitses, L.A. Dorf, A.A. Litvak, and N.J. Fisch, Journal of Applied Physics 88 (2000) 1263. [3] A. Smirnov, Y. Raitses, and N.J. Fisch, IEEE Transactions on Plasma Science 36 (2008) 1998.

  2. Experimental observation of precursor solitons in a flowing complex plasma

    CERN Document Server

    Jaiswal, Surabhi; Sen, A

    2015-01-01

    The excitation of precursor solitons ahead of a rapidly moving object in a fluid, a spectacular phenomenon in hydrodynamics that has often been observed ahead of moving ships, has surprisingly not been investigated in plasmas where the fluid model holds good for low frequency excitations such as ion acoustic waves. In this paper we report the first experimental observation of precursor solitons in a flowing dusty plasma. The nonlinear solitary dust acoustic waves (DAWs) are excited by a supersonic mass flow of the dust particles over an electrostatic potential hill. In a frame where the fluid is stationary and the hill is moving the solitons propagate in the upstream direction as precursors while wake structures consisting of linear DAWs are seen to propagate in the downstream region. A theoretical explanation of these excitations based on the forced Korteweg-deVries model equation is provided and their practical implications in situations involving a charged object moving in a plasma are discussed.

  3. Experimental observation of precursor solitons in a flowing complex plasma

    Science.gov (United States)

    Jaiswal, Surabhi; Bandyopadhyay, P.; Sen, A.

    2016-04-01

    The excitation of precursor solitons ahead of a rapidly moving object in a fluid, a spectacular phenomenon in hydrodynamics that has often been observed ahead of moving ships, has surprisingly not been investigated in plasmas where the fluid model holds good for low frequency excitations such as ion acoustic waves. In this Rapid Communication we report an experimental observation of precursor solitons in a flowing dusty plasma. The nonlinear solitary dust acoustic waves (DAWs) are excited by a supersonic mass flow of the dust particles over an electrostatic potential hill. In a frame where the fluid is stationary and the hill is moving the solitons propagate in the upstream direction as precursors while wake structures consisting of linear DAWs are seen to propagate in the downstream region. A theoretical explanation of these excitations based on the forced Korteweg-deVries model equation is provided and their practical implications in situations involving a charged object moving in a plasma are discussed.

  4. Establishing isokinetic flow for a plasma torch exhaust gas diagnostic for a plasma hearth furnace

    Energy Technology Data Exchange (ETDEWEB)

    Pollack, B.R.

    1996-05-01

    Real time monitoring of toxic metallic effluents in confined gas streams can be accomplished through use of Microwave Induced Plasmas to perform atomic emission spectroscopy, For this diagnostic to be viable it is necessary that it sample from the flowstream of interest in an isokinetic manner. A method of isokinetic sampling was established for this device for use in the exhaust system of a plasma hearth vitrification furnace. The flow and entrained particulate environment were simulated in the laboratory setting using a variable flow duct of the same dimensions (8-inch diameter, schedule 40) as that in the field and was loaded with similar particulate (less than 10 {mu}m in diameter) of lake bed soil typically used in the vitrification process. The flow from the furnace was assumed to be straight flow. To reproduce this effect a flow straightener was installed in the device. An isokinetic sampling train was designed to include the plasma torch, with microwave power input operating at 2.45 GHz, to match local freestream velocities between 800 and 2400 ft/sec. The isokinetic sampling system worked as planned and the plasma torch had no difficulty operating at the required flowrates. Simulation of the particulate suspension was also successful. Steady particle feeds were maintained over long periods of time and the plasma diagnostic responded as expected.

  5. Convective flow zones in filament-discharge plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M J; McWilliams, R [Dept. of Physics and Astronomy, University of California, Irvine 92697 (United States)

    2007-01-15

    Convective flow zones were found to surround the discharge current in an electron-beam generated argon plasma. Flow zones were created by the electric field associated with the injected electron beam. A sheet-beam was injected along a confining magnetic field. The discharge current and voltage were varied, and the ion flow near the beam was studied via laser-induced fluorescence. It was observed that the drift velocity, and thus the inferred electric field, was nearly constant even with increasing current, yet the electron density of the beam did increase.

  6. Geodesic plasma flows instabilities of Riemann twisted solar loops

    CERN Document Server

    de Andrade, Garcia

    2007-01-01

    Riemann and sectional curvatures of magnetic twisted flux tubes in Riemannian manifold are computed to investigate the stability of the plasma astrophysical tubes. The geodesic equations are used to show that in the case of thick magnetic tubes, the curvature of planar (Frenet torsion-free) tubes have the effect ct of damping the flow speed along the tube. Stability of geodesic flows in the Riemannian twisted thin tubes (almost filaments), against constant radial perturbations is investigated by using the method of negative sectional curvature for unstable flows. No special form of the flow like Beltrami flows is admitted, and the proof is general for the case of thin magnetic flux tubes. In the magnetic equilibrium state, the twist of the tube is shown to display also a damping effect on the toroidal velocity of the plasma flow. It is found that for positive perturbations and angular speed of the flow, instability is achieved, since the sectional Ricci curvature of the magnetic twisted tube metric is negativ...

  7. Gas flow driven by thermal creep in dusty plasma

    International Nuclear Information System (INIS)

    Thermal creep flow (TCF) is a flow of gas driven by a temperature gradient along a solid boundary. Here, TCF is demonstrated experimentally in a dusty plasma. Stripes on a glass box are heated by laser beam absorption, leading to both TCF and a thermophoretic force. The design of the experiment allows isolating the effect of TCF. A stirring motion of the dust particle suspension is observed. By eliminating all other explanations for this motion, we conclude that TCF at the boundary couples by drag to the bulk gas, causing the bulk gas to flow, thereby stirring the suspension of dust particles. This result provides an experimental verification, for the field of fluid mechanics, that TCF in the slip-flow regime causes steady-state gas flow in a confined volume.

  8. Plasma Flows within the Context of Biasing Experiments

    Institute of Scientific and Technical Information of China (English)

    M. Tendler

    2004-01-01

    The understanding and reduction of turbulent transport in magnetic confinement devices is not only an academic task, but also the matter of practical interest, since high confinement is chosen as the regime for ITER and possible future reactors it reduces both the size and the cost. Since the pioneering work on CCT a lot of work has been devoted to the effect of electric field biasing carried out on many tokamaks, which in general leads to a strongly varying radial electric fields as a function of radius and a resulting sheared E ×B flow, giving rise to improved confinement properties.The issue of plasma flows is utterly fundamental for understanding of tokamaks aimed at the achievement of fusion energy. This appears in the well known neoclassical theory as the most accomplished and self-consistent basis for understanding of fusion plasmas. It pertains to the novel concept of "zonal flows" emerging from the recent development of gyro-kinetic transport codes. The poloidal and toroidal flows are also crucial for the concept of the electric field shear suppression of plasma turbulence in tokamaks. Yet, this timely and topical issue has remained largely unaddressed experimentally because of great difficulties of measuring flows in plasmas.Recently, the team of scientists from all over the world developed innovative configuration of probes yielding the flow velocity locally. This timely and topical diagnostics has been successfully applied on many tokamaks ranging from the huge JET through medium TEXTOR to a small CASTOR due to the excellent collaboration and coordination between research teams. Results caused large interest of fusion community born out by numerous invited talks delivered at the major international meetings.

  9. Plasma equilibria and stationary flows in axisymmetric systems. Pt. 1

    International Nuclear Information System (INIS)

    During discharges within a tokamak device such as JET fluctuations are observed in the plasma, of plasma density, temperature, electric potential and of the magnetic field. These fluctuations have complicated structure and are linked with different kinds of instabilities. However, it is not clear which instabilities are most important in determining the behaviour of the plasma. A comprehensive numerical theory which can predict the effect of the instabilities on the transport of plasma in axisymmetric systems has been sought using the static Grad-Shafranov-Schlueter (SGSS) equation as a basis. However, the static equation was over simplified for the situation in JET with additional heating giving rise to large toroidal flows, and an extended equation (EGSS) was developed. The results of the study include the discovery of algebraic branches of solutions to the EGSS equation even for very small poloidal flows, solutions to the inverse problem for the SGSS and EGSS equations using Fourier decomposition, classification of the boundary condition at the magnetic axis, demonstration of a visible effect of the poloidal flow on the separation of the density surface and the magnetic surface an indication of the existence of multiple branches of solutions to the EGSS and SGSS equations and their relation to stability properties. (U.K.)

  10. Plasma spray nozzle with low overspray and collimated flow

    Science.gov (United States)

    Beason, Jr., George P. (Inventor); McKechnie, Timothy N. (Inventor); Power, Christopher A. (Inventor)

    1996-01-01

    An improved nozzle for reducing overspray in high temperature supersonic plasma spray devices comprises a body defining an internal passageway having an upstream end and a downstream end through which a selected plasma gas is directed. The nozzle passageway has a generally converging/diverging Laval shape with its upstream end converging to a throat section and its downstream end diverging from the throat section. The upstream end of the passageway is configured to accommodate a high current cathode for producing an electrical arc in the passageway to heat and ionize the gas flow to plasma form as it moves along the passageway. The downstream end of the nozzle is uniquely configured through the methodology of this invention to have a contoured bell-shape that diverges from the throat to the exit of the nozzle. Coating material in powder form is injected into the plasma flow in the region of the bell-shaped downstream end of the nozzle and the powder particles become entrained in the flow. The unique bell shape of the nozzle downstream end produces a plasma spray that is ideally expanded at the nozzle exit and thus virtually free of shock phenomena, and that is highly collimated so as to exhibit significantly reduced fanning and diffusion between the nozzle and the target. The overall result is a significant reduction in the amount of material escaping from the plasma stream in the form of overspray and a corresponding improvement in the cost of the coating operation and in the quality and integrity of the coating itself.

  11. Gas flow dependence of atmospheric pressure plasma needle discharge characteristics

    Science.gov (United States)

    Qian, Muyang; Yang, Congying; Liu, Sanqiu; Chen, Xiaochang; Ni, Gengsong; Wang, Dezhen

    2016-04-01

    In this paper, a two-dimensional coupled model of neutral gas flow and plasma dynamics is presented to explain the gas flow dependence of discharge characteristics in helium plasma needle at atmospherics pressure. The diffusional mixing layer between the helium jet core and the ambient air has a moderate effect on the streamer propagation. The obtained simulation results present that the streamer shows the ring-shaped emission profile at a moderate gas flow rate. The key chemical reactions which drive the streamer propagation are electron-impact ionization of helium neutral, nitrogen and oxygen molecules. At a moderate gas flow rate of 0.5 slm, a significant increase in propagation velocity of the streamer is observed due to appropriate quantity of impurities air diffuse into the helium. Besides, when the gas flow rate is below 0.35 slm, the radial density of ground-state atomic oxygen peaks along the axis of symmetry. However, when the gas flow rate is above 0.5 slm, a ring-shaped density distribution appears. The peak density is on the order of 1020 m-3 at 10 ns in our work.

  12. Axisymmetric equilibria with pressure anisotropy and plasma flow

    Science.gov (United States)

    Throumoulopoulos, George; Evangelias, Achilleas

    2015-11-01

    A generalised Grad-Shafranov equation that governs the equilibrium of an axisymmetric toroidal plasma with anisotropic pressure and incompressible flow of arbitrary direction is derived. This equation includes six free surface functions and recovers known Grad-Shafranov-like equations in the literature as well as the usual static, isotropic one. The form of the generalised equation indicates that pressure anisotropy and flow act additively on equilibrium. In addition, two sets of analytical solutions, an extended Solovev one with a free boundary and an extended Hernegger-Maschke one for a plasma surrounded by a fixed boundary possessing an X-point, are constructed, particularly in relevance to the ITER and NSTX tokamaks. Furthermore, the impacts both of pressure anisotropy and plasma flow on these equilibria are examined. It turns out that depending on the maximum value and the shape of an anisotropy function, the anisotropy can act either paramagnetically or diamagnetically. Also, in most of the cases considered both the anisotropy and the flow have stronger effects on NSTX equilibria than on ITER ones. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from (a) the National Programme for the Controlled Thermonuclear Fusion, Hellenic Republic, (b) Euratom research and training programme 2014-2018.

  13. QUICK-FIRE: Plasma flow driven implosion experiments

    International Nuclear Information System (INIS)

    High speed plasma implosions involving megajoules of energy, and sub-microsecond implosion times are expected to require additional stages of power conditioning between realistic primary energy sources and the implosion system. Plasma flow switches and vacuum inductive stores represent attractive alternates to the high speed fuse and atmospheric store techniques which have been previously reported for powering such plasma experiments. In experiments being conducted at the Air Force Weapons Lab, a washer shaped plasma accelerated to 7-10 cm/microsecond in a coaxial plasma gun configuration, represents the moving element in a vacuum store/power conditioning system of 16.5 nH inductance which stores 1-1.5 MJ at 12-14 MA. At the end of the coaxial gun, the moving element transits the 2cm axial length of the cylindrical implosion gap in 200-400 nS, delivering the magnetic energy to the implosion foil, accelerating the imploding plasma to speeds of 30-40 cm/microsecond in 350-450 nS, and delivering a projected 400 KJ of kinetic energy to the implosion

  14. Flow Visualization of Dross Formation in Plasma Cutting of Steel

    Science.gov (United States)

    Potter, K. C.; Settles, G. S.

    1996-11-01

    Along with oxy-fuel and laser cutting, plasma arc cutting is an important and widely-used manufacturing technology. When cutting mild steel plate with an oxygen plasma jet, the cut edges can be of high quality. However, at cutting speeds above or below optimum, dross solidifies and clings to the bottom of the cut edge, requiring an additional finishing step. Using a commercial plasma torch, high-speed photography and videography have been employed, perhaps for the first time, to examine the melt ejection and formation of dross during plasma cutting. Highly-magnified images at 30-500 frames/sec reveal that dross formation is related to the wetting of the kerf edges by the molten ejecta, whence some of the melt is drawn into dross nodules by surface tension differences. At low cutting speeds a wide kerf promotes sideways ejecta flow and edge wetting, while at high cutting speeds the narrow gap between the plasma jet and kerf leading edge is insufficient to convey the ejecta, which is then forced to the sides. Between these extremes lies a zone of dross-free cutting where the melt is ejected solely ahead of the plasma jet without wetting the kerf edges. (Research supported by the Hypertherm Corp.)

  15. Zonal Flows and Turbulence in Fluids and Plasmas

    CERN Document Server

    Parker, Jeffrey B

    2015-01-01

    In geophysical and plasma contexts, zonal flows are well known to arise out of turbulence. We elucidate the transition from statistically homogeneous turbulence without zonal flows to statistically inhomogeneous turbulence with steady zonal flows. Starting from the Hasegawa--Mima equation, we employ both the quasilinear approximation and a statistical average, which retains a great deal of the qualitative behavior of the full system. Within the resulting framework known as CE2, we extend recent understanding of the symmetry-breaking `zonostrophic instability'. Zonostrophic instability can be understood in a very general way as the instability of some turbulent background spectrum to a zonally symmetric coherent mode. As a special case, the background spectrum can consist of only a single mode. We find that in this case the dispersion relation of zonostrophic instability from the CE2 formalism reduces exactly to that of the 4-mode truncation of generalized modulational instability. We then show that zonal flow...

  16. Plasma-Assisted Chemistry in High-Speed Flow

    Institute of Scientific and Technical Information of China (English)

    Sergey B.LEONOV; Dmitry A.YARANTSEV; Anatoly P.NAPARTOVICH; Igor V.KOCHETOV

    2007-01-01

    Fundamental problems related to the high-speed combustion are analyzed. The result of plasma-chemical modeling is presented as a motivation of experimental activity.Numerical simulations of the effect of uniform non-equilibrium discharge on the premixed hydrogen and ethylene-air mixture in supersonic flow demonstrate an advantage of such a technique over a heating.Experimental results on multi-electrode non-uniform discharge maintenance behind wallstep and in cavity of supersonic flow are presented.The model test on hydrogen and ethylene ignition is demonstrated at direct fuel injection to low-temperature high-speed airflow.

  17. An analytic model for flow reversal in divertor plasmas

    International Nuclear Information System (INIS)

    An analytic model is developed and used to study the phenomenon of flow reversal which is observed in two-dimensional simulations of divertor plasmas. The effect is shown to be caused by the radial spread of neutral particles emitted from the divertor target which can lead to a strong peaking of the ionization source at certain radial locations. The results indicate that flow reversal over a portion of the width of the scrape-off layer is inevitable in high recycling conditions. Implications for impurity transport and particle removal in reactors are discussed

  18. Plasma flow switch and foil implosion experiments on Pegasus II

    International Nuclear Information System (INIS)

    Pegasus II is the upgraded version of Pegasus, a pulsed power machine used in the Los Alamos AGEX (Above Ground EXperiments) program. A goal of the program is to produce an intense (> 100 TW) source of soft x-rays from the thermalization of the kinetic energy of a 1 to 10 MJ plasma implosion. The radiation pulse should have a maximum duration of several 10's of nanoseconds and will be used in the study of fusion conditions and material properties. The radiating plasma source will be generated by the thermalization of the kinetic energy of an imploding cylindrical, thin, metallic foil. This paper addresses experiments done on a capacitor bank to develop a switch (plasma flow switch) to switch the bank current into the load at peak current. This allows efficient coupling of bank energy into foil kinetic energy

  19. Ion collection by probing objects in flowing magnetized plasmas

    International Nuclear Information System (INIS)

    A new one-dimensional collisionless kinetic model is developed for the flow of ions to probing structures in drifting plasmas. The cross-field flow into the presheath is modelled by accounting consistently for particle exchange between the collection flux tube and the outer plasma. Numerical solutions of the self-consistent plasma/sheath equations are obtained with arbitrary external ion temperature and parallel plasma flow velocity. Results are presented of the spatial dependence of the ion distribution function as well as its moments (density, particle flux, temperature, and power flux). The ion current to the probe is obtained and the ratio of the upstream to downstream currents is found to be well represented by the form R = exp[Kud], where K = 1.66 for Ti = Te and ud is the drift velocity in units of (Te/mi)1/2. The results agree well with comparable recent fluid calculations but show substantial deviations from other models which ignore particle exchange out of the presheath. No evidence is found of the formation of shocks in the downstream wake, contrary to the implications of some fluid theories. We have also extended the previous kinetic model by generalizing cross-field transport and adding ionization to the source of the Boltzmann equation along the presheath. Ion sheath current density and ratio(R) of upstream to downstream current are obtained as a function of plasma drift velocity, equivalent viscosity, ion temperature, and ionization rate. Constants(K) in the form R = exp[Kud] are obtained in terms of viscosity, ion temperature, and ionization rate. The effect of an electrical bias applied to the object on the presheath characteristics is discussed

  20. Thermonuclear dynamo inside ultracentrifuge with supersonic plasma flow stabilization

    Science.gov (United States)

    Winterberg, F.

    2016-01-01

    Einstein's general theory of relativity implies the existence of virtual negative masses in the rotational reference frame of an ultracentrifuge with the negative mass density of the same order of magnitude as the positive mass density of a neutron star. In an ultracentrifuge, the repulsive gravitational field of this negative mass can simulate the attractive positive mass of a mini-neutron star, and for this reason can radially confine a dense thermonuclear plasma placed inside the centrifuge, very much as the positive mass of a star confines its plasma by its own attractive gravitational field. If the centrifuge is placed in an externally magnetic field to act as the seed field of a magnetohydrodynamic generator, the configuration resembles a magnetar driven by the release of energy through nuclear fusion, accelerating the plasma to supersonic velocities, with the magnetic field produced by the thermomagnetic Nernst effect insulating the hot plasma from the cold wall of the centrifuge. Because of the supersonic flow and the high plasma density the configuration is stable.

  1. Thermonuclear dynamo inside ultracentrifuge with supersonic plasma flow stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Winterberg, F. [University of Nevada, Reno, Reno, Nevada (United States)

    2016-01-15

    Einstein's general theory of relativity implies the existence of virtual negative masses in the rotational reference frame of an ultracentrifuge with the negative mass density of the same order of magnitude as the positive mass density of a neutron star. In an ultracentrifuge, the repulsive gravitational field of this negative mass can simulate the attractive positive mass of a mini-neutron star, and for this reason can radially confine a dense thermonuclear plasma placed inside the centrifuge, very much as the positive mass of a star confines its plasma by its own attractive gravitational field. If the centrifuge is placed in an externally magnetic field to act as the seed field of a magnetohydrodynamic generator, the configuration resembles a magnetar driven by the release of energy through nuclear fusion, accelerating the plasma to supersonic velocities, with the magnetic field produced by the thermomagnetic Nernst effect insulating the hot plasma from the cold wall of the centrifuge. Because of the supersonic flow and the high plasma density the configuration is stable.

  2. Thermonuclear dynamo inside ultracentrifuge with supersonic plasma flow stabilization

    International Nuclear Information System (INIS)

    Einstein's general theory of relativity implies the existence of virtual negative masses in the rotational reference frame of an ultracentrifuge with the negative mass density of the same order of magnitude as the positive mass density of a neutron star. In an ultracentrifuge, the repulsive gravitational field of this negative mass can simulate the attractive positive mass of a mini-neutron star, and for this reason can radially confine a dense thermonuclear plasma placed inside the centrifuge, very much as the positive mass of a star confines its plasma by its own attractive gravitational field. If the centrifuge is placed in an externally magnetic field to act as the seed field of a magnetohydrodynamic generator, the configuration resembles a magnetar driven by the release of energy through nuclear fusion, accelerating the plasma to supersonic velocities, with the magnetic field produced by the thermomagnetic Nernst effect insulating the hot plasma from the cold wall of the centrifuge. Because of the supersonic flow and the high plasma density the configuration is stable

  3. On the plasma flow inside magnetic tornadoes on the Sun

    CERN Document Server

    Wedemeyer, Sven

    2014-01-01

    High-resolution observations with the Swedish 1-m Solar Telescope (SST) and the Solar Dynamics Observatory (SDO) reveal rotating magnetic field structures that extend from the solar surface into the chromosphere and the corona. These so-called magnetic tornadoes are primarily detected as rings or spirals of rotating plasma in the Ca II 854.2 nm line core (also known as chromospheric swirls). Detailed numerical simulations show that the observed chromospheric plasma motion is caused by the rotation of magnetic field structures, which again are driven by photospheric vortex flows at their footpoints. Under the right conditions, two vortex flow systems are stacked on top of each other. We refer to the lower vortex, which extends from the low photosphere into the convection zone, as intergranular vortex flow (IVF). Once a magnetic field structure is co-located with an IVF, the rotation is mediated into the upper atmospheric layers and an atmospheric vortex flow (AVF, or magnetic tornado) is generated. In contrast...

  4. On the plasma flow inside magnetic tornadoes on the Sun

    Science.gov (United States)

    Wedemeyer, Sven; Steiner, Oskar

    2014-12-01

    High-resolution observations with the Swedish 1-m Solar Telescope (SST) and the Solar Dynamics Observatory (SDO) reveal rotating magnetic field structures that extend from the solar surface into the chromosphere and the corona. These so-called magnetic tornadoes are primarily detected as rings or spirals of rotating plasma in the Ca II 854.2 nm line core (also known as chromospheric swirls). Detailed numerical simulations show that the observed chromospheric plasma motion is caused by the rotation of magnetic field structures, which again are driven by photospheric vortex flows at their footpoints. Under the right conditions, two vortex flow systems are stacked on top of each other. We refer to the lower vortex, which extends from the low photosphere into the convection zone, as intergranular vortex flow (IVF). Once a magnetic field structure is co-located with an IVF, the rotation is mediated into the upper atmospheric layers and an atmospheric vortex flow (AVF, or magnetic tornado) is generated. In contrast to the recent work by Shelyag et al. (2013, ApJ, 776, L4), we demonstrate that particle trajectories in a simulated magnetic tornado indeed follow spirals and argue that the properties of the trajectories decisively depend on the location in the atmosphere and the strength of the magnetic field.

  5. Flow cytometric immunophenotypic characteristics of plasma cell leukemia

    Directory of Open Access Journals (Sweden)

    Barbara Kruk

    2011-04-01

    Full Text Available The aim of this prospective study was to define the flow cytometric characteristics of simultaneously investigated bone marrow and peripheral blood plasma cells antigens expression in 36 plasma cell leukemia (PCL patients. The immunophenotypic profile of plasma cells was determined with a panel of monoclonal antibodies. The antigen expression intensity was calculated as relative fluorescence intensity (RFI. Bone marrow plasma cells showed expression of particular antigens in the following proportion of cases: CD49d 100%, CD29 94%, CD54 93%, CD44 83%, CD56 60%, CD18 26%, CD11b 29%, CD11a 19%, CD117 27%, CD71 30%, CD126 100% and CD19 0%, while the expression of those antigens on peripheral blood plasma cells was present in the following percentage of patients: CD49d 100%, CD29 96%, CD54 93%, CD44 95%, CD56 56%, CD18 50%, CD11b 53%, CD11a 29%, CD117 26%, CD71 28%, CD126 100% and CD19 0%. The expression of CD54 was significantly higher than that of adhesion molecules belonging to the integrin b2 family: CD11a, CD18 and CD11b, on both bone marrow and peripheral blood cells (p < 0.01. Expression of CD18, CD11a and CD11b was differential between two cell compartments: lower on bone marrow and higher on peripheral blood cells. We found that plasma cells in the bone marrow of patients with plasma cell leukaemia showed significantly greater granularity and size than those in the peripheral blood (p = 0.0001 and p = 0.04, respectively. However, no differences in cell size or granularity were revealed between bone marrow plasma cells from patients with PCL and multiple myeloma. In conclusion, impaired expression of adhesion molecules such as CD11a/CD18 (LFA-1 or CD56 may explain hematogenic dissemination characterizing PCL. The following pattern of adhesion molecule expression according to the proportion of plasma cells expressing a given antigen in peripheral blood and bone marrow and arranged in diminishing order may be established: CD49d > CD44 > CD54

  6. UTILIZATION OF WASTE PLASTIC BOTTLES IN ASPHALT MIXTURE

    Directory of Open Access Journals (Sweden)

    TAHER BAGHAEE MOGHADDAM

    2013-06-01

    Full Text Available Nowadays, large amounts of waste materials are being produced in the world. One of the waste materials is plastic bottle. Generating disposable plastic bottles is becoming a major problem in many countries. Using waste plastic as a secondary material in construction projects would be a solution to overcome the crisis of producing large amount of waste plastics in one hand and improving the structure’s characteristics such as resistance against cracking on the other hand. This study aimed to investigate the effects of adding plastic bottles in road pavement. Marshall properties as well as specific gravity of asphalt mixture containing different percentages of plastic bottles were evaluated. Besides, Optimum Asphalt Content (OAC was calculated for each percentages of plastic bottles used in the mix. The stiffness and fatigue characteristics of mixture were assessed at OAC value. Results showed that the stability and flow values of asphalt mixture increased by adding waste crushed plastic bottle into the asphalt mixture. Further, it was shown that the bulk specific gravity and stiffness of mixtures increased by adding lower amount of plastic bottles; however, adding higher amounts of plastic resulted in lower specific gravity and mix stiffness. In addition, it was concluded that the mixtures containing waste plastic bottles have lower OAC values compared to the conventional mixture, and this may reduce the amount of asphalt binder can be used in road construction projects. Besides, the mixtures containing waste plastic showed significantly greater fatigue resistance than the conventional mixture.

  7. Dielectric barrier discharge plasma actuator for flow control

    Science.gov (United States)

    Opaits, Dmitry Florievich

    Electrohydrodynamic (EHD) and magnetohydrodynamic phenomena are being widely studied for aerodynamic applications. The major effects of these phenomena are heating of the gas, body force generation, and enthalpy addition or extraction, [1, 2, 3]. In particular, asymmetric dielectric barrier discharge (DBD) plasma actuators are known to be effective EHD device in aerodynamic control, [4, 5]. Experiments have demonstrated their effectiveness in separation control, acoustic noise reduction, and other aeronautic applications. In contrast to conventional DBD actuators driven by sinusoidal voltages, we proposed and used a voltage profile consisting of nanosecond pulses superimposed on dc bias voltage. This produces what is essentially a non-self-sustained discharge: the plasma is generated by repetitive short pulses, and the pushing of the gas occurs primarily due to the bias voltage. The advantage of this non-self-sustained discharge is that the parameters of ionizing pulses and the driving bias voltage can be varied independently, which adds flexibility to control and optimization of the actuators performance. Experimental studies were conducted of a flow induced in a quiescent room air by a single DBD actuator. A new approach for non-intrusive diagnostics of plasma actuator induced flows in quiescent gas was proposed, consisting of three elements coupled together: the Schlieren technique, burst mode of plasma actuator operation, and 2-D numerical fluid modeling. During the experiments, it was found that DBD performance is severely limited by surface charge accumulation on the dielectric. Several ways to mitigate the surface charge were found: using a reversing DC bias potential, three-electrode configuration, slightly conductive dielectrics, and semi conductive coatings. Force balance measurements proved the effectiveness of the suggested configurations and advantages of the new voltage profile (pulses+bias) over the traditional sinusoidal one at relatively low

  8. Production of a High-Mach-Number Plasma Flow for an Advanced Plasma Space Thruster

    Institute of Scientific and Technical Information of China (English)

    M.Inutake; K. Yoshino; S. Fujimura; H. Tobari; T. Yagai; Y. Hosokawa; R. Sato; K. Hattori; A. Ando

    2004-01-01

    A higher specific impulse and a larger thrust are required for a manned interplanetary space thruster. Prior to a realization of a fusion-plasma thruster, a magneto-plasma-dynamic arcjet (MPDA) powered by a fission reactor is one of the promising candidates for a manned Mars space thruster. The MPDA plasma is accelerated axially by a self-induced j × B force. Thrust performance of the MPDA is expected to increase by applying a magnetic nozzle instead of a solid nozzle. In order to get a much higher thruster performance, two methods have been investigated in the HITOP device, Tohoku University. One is to use a magnetic Laval nozzle in the vicinity of the MPDA muzzle for converting the high ion thermal energy to the axial flow energy. The other is to heat ions by use of an ICRF antenna in the divergent magnetic nozzle. It is found that by use of a small-sized Laval-type magnetic nozzle, the subsonic flow near the muzzle is converted to be supersonic through the magnetic Laval nozzle. A fast-flowing plasma is successfully heated by use of an ICRF antenna in the magnetic beach configuration.

  9. Critical gradients and plasma flows in the edge plasma of Alcator C-Moda)

    Science.gov (United States)

    Labombard, B.; Hughes, J. W.; Smick, N.; Graf, A.; Marr, K.; McDermott, R.; Reinke, M.; Greenwald, M.; Lipschultz, B.; Terry, J. L.; Whyte, D. G.; Zweben, S. J.; Alcator C-Mod Team

    2008-05-01

    Recent experiments have led to a fundamental shift in our view of edge transport physics; transport near the last-closed flux surface may be more appropriately described in terms of a critical gradient phenomenon rather than a diffusive and/or convective paradigm. Edge pressure gradients, normalized by the square of the poloidal magnetic field strength, appear invariant in plasmas with the same normalized collisionality, despite vastly different currents and magnetic fields—a behavior that connects with first-principles electromagnetic plasma turbulence simulations. Near-sonic scrape-off layer (SOL) flows impose a cocurrent rotation boundary condition on the confined plasma when B ×∇B points toward the active x-point, suggesting a link to the concomitant reduction in input power needed to attain high-confinement modes. Indeed, low-confinement mode plasmas are found to attain higher edge pressure gradients in this configuration, independent of the direction of B, evidence that SOL flows may affect transport and "critical gradient" values in the edge plasma.

  10. Quick-fire: Plasma flow driven implosion experiments

    International Nuclear Information System (INIS)

    High speed plasma implosions involving megajoules of energy, and sub-microsecond implosion times are expected to require additional stages of power conditioning between realistic primary energy sources and the implosion system. Plasma flow switches and vacuum inductive stores represent attractive alternates to the high speed fuse and atmospheric store techniques which have been previously reported for powering such plasma experiments. In experiments being conducted at the Air Force Weapons Lab, a washer shaped plasma accelerated to 7-10 cm/microsecond in a coaxial plasma gun configuration, represents the moving element in a vacuum store/power conditioning system of 16.5 nH inductance which stores 1-1.5 MJ at 12-14 MA. At the end of the coaxial gun, the moving element transits the 2cm axial length of the cylindrical implosion gap in 200-400 nS, delivering the magnetic energy to the implosion foil, accelerating the imploding plasma to speeds of 30-40 cm/microsecond in 350-450 nS, and delivering a projected 400 KJ of kinetic energy to the implosion. Experiments have been conducted using the SHIVA STAR capacitor bank operating at 6 MJ stored energy in which performance has been monitored by electrical diagnostics, magnetic probes, and axial and radial viewing high speed visible and X-Ray photographs to assess the performance of the coaxial run and coaxial to radial transition. Time and spectrally resolved X-Ray diagnostics are used to assess implosion quality and performance and results are compared to kinematic and MHD models

  11. Foil implosion studies with a plasma flow switch

    International Nuclear Information System (INIS)

    A plasma flow switch has been developed for the 1.5 MJ Pegasus capacitor bank to efficiently utilize the bank energy to drive a foil implosion. The object of this activity is to generate an intense burst of soft x-rays when the foil stagnates and thermalizes on axis. The peak current of the Pegasus bank, determined from the charge voltage divided by the characteristic impedance of the capacitor bank is -- 10 MA. When used to perform direct-drive, foil implosion experiments, the foil collapses to the axis when the current has risen to only -- 3 MA. The kinetic energy of the imploding foil for the direct-drive configuration cannot exceed -- 25% of the bank energy (lossless calculation). The plasma flow switch has been designed to have a conduction time of -- 4 μsec and a commutation time of -- 0.2 μsec. This permits flow implosion experiments to be performed at peak current. The soft x-ray output, as determined by volometry and by an array of filtered x-ray diodes, is compared for the two modes of operation

  12. Nonlinear electromagnetic gyrokinetic equation for plasmas with large mean flows

    International Nuclear Information System (INIS)

    A new nonlinear electromagnetic gyrokinetic equation is derived for plasmas with large flow velocities on the order of the ion thermal speed. The gyrokinetic equation derived here is given in the form which is valid for general magnetic geometries including the slab, cylindrical and toroidal configurations. The source term for the anomalous viscosity arising through the Reynolds stress is identified in the gyrokinetic equation. For the toroidally rotating plasma, particle, energy and momentum balance equations as well as the detailed definitions of the anomalous transport fluxes and the anomalous entropy production are shown. The quasilinear anomalous transport matrix connecting the conjugate pairs of the anomalous fluxes and the forces satisfies the Onsager symmetry. (author)

  13. New formulas for the calculation of effective renal plasma flow

    International Nuclear Information System (INIS)

    Estimation of effective renal plasma flow (ERPF) can be made easily, inexpensively, and accurately by means of a single plasma concentration determination, sampled 44 min after injection of 131I-orthoiodohippurate (OIH). We originally established predictive regression equations based on a series of patients with a wide variety of diseases and a few normal potential kidney donors. The equation best fitting that data was parabolic in form and assumed a negative slope when high ERPF rates were encountered. This problem has been corrected by deriving new equations (parabolic and exponential) based on an expanded series which includes a large number of subjects with high ERPF. Errors of estimation are lower than those of the more classic para-aminohippuric acid (PAH) clearances and well within the exigencies of clinical practice. (orig.)

  14. Kolmogorov flow in two dimensional strongly coupled dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Akanksha; Ganesh, R., E-mail: ganesh@ipr.res.in; Joy, Ashwin [Institute for Plasma Research, Bhat Gandhinagar, Gujarat 382 428 (India)

    2014-07-15

    Undriven, incompressible Kolmogorov flow in two dimensional doubly periodic strongly coupled dusty plasma is modelled using generalised hydrodynamics, both in linear and nonlinear regime. A complete stability diagram is obtained for low Reynolds numbers R and for a range of viscoelastic relaxation time τ{sub m} [0 < τ{sub m} < 10]. For the system size considered, using a linear stability analysis, similar to Navier Stokes fluid (τ{sub m} = 0), it is found that for Reynolds number beyond a critical R, say R{sub c}, the Kolmogorov flow becomes unstable. Importantly, it is found that R{sub c} is strongly reduced for increasing values of τ{sub m}. A critical τ{sub m}{sup c} is found above which Kolmogorov flow is unconditionally unstable and becomes independent of Reynolds number. For R < R{sub c}, the neutral stability regime found in Navier Stokes fluid (τ{sub m} = 0) is now found to be a damped regime in viscoelastic fluids, thus changing the fundamental nature of transition of Kolmogorov flow as function of Reynolds number R. A new parallelized nonlinear pseudo spectral code has been developed and is benchmarked against eigen values for Kolmogorov flow obtained from linear analysis. Nonlinear states obtained from the pseudo spectral code exhibit cyclicity and pattern formation in vorticity and viscoelastic oscillations in energy.

  15. Turbulent convective flows in the solar photospheric plasma

    Science.gov (United States)

    Caroli, A.; Giannattasio, F.; Fanfoni, M.; Del Moro, D.; Consolini, G.; Berrilli, F.

    2015-10-01

    > The origin of the 22-year solar magnetic cycle lies below the photosphere where multiscale plasma motions, due to turbulent convection, produce magnetic fields. The most powerful intensity and velocity signals are associated with convection cells, called granules, with a scale of typically 1 Mm and a lifetime of a few minutes. Small-scale magnetic elements (SMEs), ubiquitous on the solar photosphere, are passively transported by associated plasma flows. This advection makes their traces very suitable for defining the convective regime of the photosphere. Therefore the solar photosphere offers an exceptional opportunity to investigate convective motions, associated with compressible, stratified, magnetic, rotating and large Rayleigh number stellar plasmas. The magnetograms used here come from a Hinode/SOT uninterrupted 25-hour sequence of spectropolarimetric images. The mean-square displacement of SMEs has been modelled with a power law with spectral index . We found for times up to and for times up to . An alternative way to investigate the advective-diffusive motion of SMEs is to look at the evolution of the two-dimensional probability distribution function (PDF) for the displacements. Although at very short time scales the PDFs are affected by pixel resolution, for times shorter than the PDFs seem to broaden symmetrically with time. In contrast, at longer times a multi-peaked feature of the PDFs emerges, which suggests the non-trivial nature of the diffusion-advection process of magnetic elements. A Voronoi distribution analysis shows that the observed small-scale distribution of SMEs involves the complex details of highly nonlinear small-scale interactions of turbulent convective flows detected in solar photospheric plasma.

  16. Magnetized plasma flow injection into tokamak and high-beta compact torus plasmas

    Science.gov (United States)

    Matsunaga, Hiroyuki; Komoriya, Yuuki; Tazawa, Hiroyasu; Asai, Tomohiko; Takahashi, Tsutomu; Steinhauer, Loren; Itagaki, Hirotomo; Onchi, Takumi; Hirose, Akira

    2010-11-01

    As an application of a magnetized coaxial plasma gun (MCPG), magnetic helicity injection via injection of a highly elongated compact torus (magnetized plasma flow: MPF) has been conducted on both tokamak and field-reversed configuration (FRC) plasmas. The injected plasmoid has significant amounts of helicity and particle contents and has been proposed as a fueling and a current drive method for various torus systems. In the FRC, MPF is expected to generate partially spherical tokamak like FRC equilibrium by injecting a significant amount of magnetic helicity. As a circumstantial evidence of the modified equilibrium, suppressed rotational instability with toroidal mode number n = 2. MPF injection experiments have also been applied to the STOR-M tokamak as a start-up and current drive method. Differences in the responses of targets especially relation with beta value and the self-organization feature will be studied.

  17. INTERACTIONS OF FLOWING PLASMA WITH COLLECTING SPHERE/OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    HUTCHINSON, IAN H.

    2013-10-31

    The proposer’s computational flowing plasma group, supported in part by NSF/DOE since 2006, has been enormously productive. It has published 22 journal articles, of which 3 are in Physical Review Letters; received a total of 330 citations, and made 5 invited and numerous contributed presentations at international conferences. In addition, other groups have published at least 3 papers [20-22] based upon results they have obtained from the SCEPTIC code, developed by the proposer. The codes developed for this subject are Particle In Cell (PIC) codes, representing the entire ion distribution function and its variation in space in the vicinity of an absorbing object.

  18. ''QUICK-FIRE'' plasma flow driven implosion experiments

    International Nuclear Information System (INIS)

    The QUICK-FIRE experimental series presently being conducted on the SHIVA STAR fast capacitor bank (120 KV, 9.3 MJ) at the Air Force Weapons Laboratory is described. Diagnostics used to measure physical quantities are listed and preliminary results from the first eight shots are presented. Initial data indicates that the performance of the coaxial gun portion of the plasma flow switch is good. Radiation yields from the unoptimized implosions are 220 KJ of soft x-rays in the 80-280 eV range with a peak power of roughly 1.25 TW. Plans for future work are outlined

  19. Synergetic effects of magnetic feedback and plasma flow on resistive wall mode stability in tokamaks

    International Nuclear Information System (INIS)

    The synergetic effects of feedback and toroidal plasma rotation on the stability of the resistive wall mode are systematically investigated by a full toroidal magnetohydrodynamic stability code MARS-F (Liu Y Q et al 2000 Phys. Plasmas 7 3681). This synergy is studied for both resistive and ideal plasma models. It is found that a magnetic feedback scheme, combined with the passive stabilization from the plasma flow, can open two stability windows as the resistive wall moves away from the plasma, as opposed to the single stability window opened by the plasma flow alone. The width of the new stability window increases with the feedback gain. The plasma rotation frequency affects both stability windows. The synergy is achieved when the feedback pushes the mode rotating in the same direction as the plasma flow. The plasma resistivity significantly enlarges the stable domain in this synergetic scheme, compared to that predicted by the ideal plasma model. (paper)

  20. Investigation on Plasma Jet Flow Phenomena During DC Air Arc Motion in Bridge-Type Contacts

    Science.gov (United States)

    Zhai, Guofu; Bo, Kai; Chen, Mo; Zhou, Xue; Qiao, Xinlei

    2016-05-01

    Arc plasma jet flow in the air was investigated under a bridge-type contacts in a DC 270 V resistive circuit. We characterized the arc plasma jet flow appearance at different currents by using high-speed photography, and two polished contacts were used to search for the relationship between roughness and plasma jet flow. Then, to make the nature of arc plasma jet flow phenomena clear, a simplified model based on magnetohydrodynamic (MHD) theory was established and calculated. The simulated DC arc plasma was presented with the temperature distribution and the current density distribution. Furthermore, the calculated arc flow velocity field showed that the circular vortex was an embodiment of the arc plasma jet flow progress. The combined action of volume force and contact surface was the main reason of the arc jet flow. supported by National Natural Science Foundation of China (Nos. 51307030, 51277038)

  1. Hybrid radio-frequency/direct-current plasma-enhanced chemical vapor deposition system for deposition on inner surfaces of polyethylene terephthalate bottles

    International Nuclear Information System (INIS)

    A hybrid radio-frequency (rf)/direct-current (dc) system has been developed to control the biasing effects during deposition of diamondlike carbon (DLC) films onto the inner wall of polyethylene terephthalate (PET) bottles. An additional dc bias is coupled to the rf electrode to produce the effect of equivalent rf self-biasing. This allows more flexible control of the deposition of the DLC films which are intended to improve the gas barrier characteristics. The experimental results demonstrate that the additional dc bias improves the adhesion strength between the DLC film and PET, although the enhancement in the gas barrier properties is not significantly larger compared to the one without dc bias. The apparatus and methodology have practical importance in the food and beverage industry.

  2. Miniaturized heat flux sensor for high enthalpy plasma flow characterization

    International Nuclear Information System (INIS)

    An improved miniaturized heat flux sensor is presented aiming at measuring extreme heat fluxes of plasma wind tunnel flows. The sensor concept is based on an in-depth thermocouple measurement with a miniaturized design and an advanced calibration approach. Moreover, a better spatial estimation of the heat flux profile along the flow cross section is realized with this improved small sensor design. Based on the linearity assumption, the heat flux is determined using the impulse response of the sensor relating the heat flux to the temperature of the embedded thermocouple. The non-integer system identification (NISI) procedure is applied that allows a calculation of the impulse response from transient calibration measurements with a known heat flux of a laser source. The results show that the new sensor leads to radially highly resolved heat flux measurement for a flow with only a few centimetres in diameter, the so far not understood non-symmetric heat flux profiles do not occur with the new sensor design. It is shown that this former effect is not a physical effect of the flow, but a drawback of the classical sensor design. (authors)

  3. The flow of plasma in the solar terrestrial environment

    Science.gov (United States)

    Schunk, Robert W.; Banks, P.; Barakat, A. R.; Crain, D. J.; Demars, H. G.; Lemaire, J.; Ma, T.-Z.; Rasmussen, C. E.; Richards, P.; Sica, R.

    1990-01-01

    The overall goal of our NASA Theory Program was to study the coupling, time delays, and feedback mechanisms between the various regions of the solar-terrestrial system in a self-consistent, quantitative manner. To accomplish this goal, it will eventually be necessary to have time-dependent macroscopic models of the different regions of the solar-terrestrial system and we are continually working toward this goal. However, with the funding from this NASA program, we concentrated on the near-earth plasma environment, including the ionosphere, the plasmasphere, and the polar wind. In this area, we developed unique global models that allowed us to study the coupling between the different regions. These results are highlighted in the next section. Another important aspect of our NASA Theory Program concerned the effect that localized 'structure' had on the macroscopic flow in the ionosphere, plasmasphere, thermosphere, and polar wind. The localized structure can be created by structured magnetospheric inputs (i.e., structured plasma convection, particle precipitation or Birkland current patterns) or time variations in these input due to storms and substorms. Also, some of the plasma flows that we predicted with our macroscopic models could be unstable, and another one of our goals was to examine the stability of our predicted flows. Because time-dependent, three-dimensional numerical models of the solar-terrestrial environment generally require extensive computer resources, they are usually based on relatively simple mathematical formulations (i.e., simple MHD or hydrodynamic formulations). Therefore, another goal of our NASA Theory Program was to study the conditions under which various mathematical formulations can be applied to specific solar-terrestrial regions. This could involve a detailed comparison of kinetic, semi-kinetic, and hydrodynamic predictions for a given polar wind scenario or it could involve the comparison of a small-scale particle-in-cell (PIC

  4. Development of a plasma generator as heat source in a rotary furnace and study of said plasma flow

    International Nuclear Information System (INIS)

    The designing of a plasma generator has been approached as a function of its structural and working parameters. A single systematic inclusive scheme is presented that defines the general parameters of such design. The requirements for a well defined (laminar) type of flow lead to studying the flow in the various zones of the plasma generator by using some electromagnetodynamic equations less or more simplified according to the region studied. A finite difference method is proposed for solving these equations, the evolution of thermodynamical and transport known functions being introduced in particular under the form of temperature functions. This study has been applied to developing a plasma generator providing laminar jets. The Reynolds number was determined for various types of flow of the plasma jet through transient flow concept. A first research of the working parameters of this plasma generator is summarized by the experimental results obtained

  5. Accelerated ions from pulsed-power-driven fast plasma flow in perpendicular magnetic field

    Science.gov (United States)

    Takezaki, Taichi; Takahashi, Kazumasa; Sasaki, Toru; Kikuchi, Takashi; Harada, Nob.

    2016-06-01

    To understand the interaction between fast plasma flow and perpendicular magnetic field, we have investigated the behavior of a one-dimensional fast plasma flow in a perpendicular magnetic field by a laboratory-scale experiment using a pulsed-power discharge. The velocity of the plasma flow generated by a tapered cone plasma focus device is about 30 km/s, and the magnetic Reynolds number is estimated to be 8.8. After flow through the perpendicular magnetic field, the accelerated ions are measured by an ion collector. To clarify the behavior of the accelerated ions and the electromagnetic fields, numerical simulations based on an electromagnetic hybrid particle-in-cell method have been carried out. The results show that the behavior of the accelerated ions corresponds qualitatively to the experimental results. Faster ions in the plasma flow are accelerated by the induced electromagnetic fields modulated with the plasma flow.

  6. Holographic optical bottle beams

    CERN Document Server

    Alpmann, Christina; Rose, Patrick; Denz, Cornelia

    2011-01-01

    We present a convolution approach for the generation of optical bottle beams that combines established techniques of holographic optical trapping with hollow intensity distributions in order to manipulate absorbing particles. The versatility of our method is demonstrated by the simultaneous stable trapping of multiple particles at defined positions. Furthermore, the presented phase shaping technique allows for the dynamic manipulation of absorbing particles along arbitrary paths.

  7. Plasma-enhanced mixing and flameholding in supersonic flow.

    Science.gov (United States)

    Firsov, Alexander; Savelkin, Konstantin V; Yarantsev, Dmitry A; Leonov, Sergey B

    2015-08-13

    The results of experimental study of plasma-based mixing, ignition and flameholding in a supersonic model combustor are presented in the paper. The model combustor has a length of 600 mm and cross section of 72 mm width and 60 mm height. The fuel is directly injected into supersonic airflow (Mach number M=2, static pressure Pst=160-250 Torr) through wall orifices. Two series of tests are focused on flameholding and mixing correspondingly. In the first series, the near-surface quasi-DC electrical discharge is generated by flush-mounted electrodes at electrical power deposition of Wpl=3-24 kW. The scope includes parametric study of ignition and flame front dynamics, and comparison of three schemes of plasma generation: the first and the second layouts examine the location of plasma generators upstream and downstream from the fuel injectors. The third pattern follows a novel approach of combined mixing/ignition technique, where the electrical discharge distributes along the fuel jet. The last pattern demonstrates a significant advantage in terms of flameholding limit. In the second series of tests, a long discharge of submicrosecond duration is generated across the flow and along the fuel jet. A gasdynamic instability of thermal cavity developed after a deposition of high-power density in a thin plasma filament promotes the air-fuel mixing. The technique studied in this work has weighty potential for high-speed combustion applications, including cold start/restart of scramjet engines and support of transition regime in dual-mode scramjet and at off-design operation. PMID:26170434

  8. Sheared plasma flow generation - a new measure for stellarator optimization

    International Nuclear Information System (INIS)

    Recent stellarator optimization efforts have primarily targeted transport measures such as quasi-symmetry, effective ripple and alignment of particle guiding center orbits with flux surfaces. For the three forms of quasi-symmetry (helical/toroidal/poloidal), as well as for a variety of nearly-omnigenous systems, this has led to significant reductions in neoclassical losses so that, at least for near-term experiments, the neoclassical transport of particles and energy can be made insignificant compared to anomalous transport. However, momentum transport properties provide an additional dimension for characterizing optimized stellarators. The momentum and flow damping features of optimized stellarators can vary widely, depending on their magnetic structure, ranging from systems with near tokamak-like properties where toroidal flows dominate to those in which poloidal flows dominate and toroidal flows are suppressed. We have developed a set of tools for self-consistently evaluating the flow characteristics of different types of stellarators based on using a moments method coupled with the DKES model; applications to a variety of stellarators will be discussed. The understanding of momentum transport in three-dimensional systems is of importance due to its relevance to transport barrier generation, enhanced confinement regime access, impurity transport, bootstrap current prediction, and magnetic island suppression. Although it is too early to define what constitutes the optimal form of momentum transport characteristics, the wide variation of possibilities in present and planned stellarator experiments provides an attractively diverse environment both for answering this question and developing improved scientific understanding. Comparisons across devices can aid in unfolding the interplay between anomalous and neoclassical damping effects as well as the impact of momentum transport properties on related plasma phenomena. (author)

  9. Control of power characteristics of ion flow in plasma-etching reactor based on beam-plasma discharge

    International Nuclear Information System (INIS)

    It is shown that on the basis of the earlier revealed effect of generating the ion flow in the beam-plasma discharge from the discharge axis, a plasma processing reactor can be created for low-energy etching of semiconductor structures. The possibility of easily controlling the density and energy of ion flow by means of varying the potential of the discharge collector is demonstrated. The charge compensation of the ion flow incident on the nonconducting surface is implemented using the modulation of the potential of the substrate holder as well as the plasma-potential modulation.

  10. Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge

    International Nuclear Information System (INIS)

    Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow ions are studied. Floating potentials in the plasma flows are measured. Ionization coefficients of the generated plasma flows and their dependence on the discharge current are studied. It is shown that at the discharge currents equal 20...30 A the vacuum arc discharge in anode material vapors can effectively create dropless and highly ionized plasma flows of different metals and provides films deposition rates, which are comparable to possibilities of the cathode vacuum arc discharge

  11. The development of physical ideas concerning the interaction of plasma flows and electrostatic fields in dusty plasmas

    International Nuclear Information System (INIS)

    The concept of the interaction of an electrostatic field and plasma flows in a dusty plasma is reviewed. This approach helps to describe many aspects of dusty plasma physics. Of basic importance in this context are processes that plasma flows introduce into interactions between dust particles. Fluctuations in plasma flows, together with those in electrostatic fields, considerably modify these interactions, with the result that like-charged particles that are far apart start attracting one another, possibly leading to their pairing. Knowledge about the attraction between distant particles is traced from the early work of 1963 through modification and improvement to its present level, when it has become possible to qualitatively estimate the parameters of the dusty plasma - dust crystal transition, and to obtain the values for the coupling constant, dust particle separations, and the transition temperature consistent with observations. The self-energy of dust particles, exceeding both their kinetic energy and interaction energy, is discussed in terms of the role of its variations. Generation mechanisms and the role of regular plasma flows are examined. Self-excitation of regular and fluctuating plasma flows gives rise to structures such as dust voids, dust vortices, dust clumps, and helical dust structures. Self-organizing structures are frequently seen both in laboratory and natural conditions. Prospects for further research are addressed and problems yet to be solved reviewed. (reviews of topical problems)

  12. Evolution of plasma flow shear and stability in the ZaP Flow Z-pinch

    International Nuclear Information System (INIS)

    The stabilizing effect of an axial flow on the m=1 kink instability in Z-pinches has been studied numerically with a linearized ideal MHD model to reveal that a sheared axial flow stabilizes the kink mode when the shear exceeds a threshold. The sheared flow stabilizing effect is investigated with the ZaP Flow Z-pinch experiment. An azimuthal array of surface mounted magnetic probes measures the fluctuation levels of the azimuthal modes m=1, 2, and 3. After pinch assembly a quiescent period is found where the mode activity is significantly reduced. The quiescent period lasts for over 2000 times the expected instability growth time in a static Z-pinch. Optical images from a fast framing camera, a two-chord HeNe interferometer, and a ruby holographic interferometer indicate a stable, discrete pinch plasma during this time. Multichord Doppler shift measurements of impurity lines show a large, sheared flow during the quiescent period and low, uniform flow profiles during periods of high mode activity. The value of the velocity shear satisfies the theoretical threshold for stability during the quiescent period and does not satisfy the threshold during the high mode activity. Experiments are conducted with varying amounts of injected neutral gas to gain an understanding of the Z-pinch formation and lifetime. (author)

  13. New numerical tools to study waves and instabilities of flowing plasmas

    OpenAIRE

    Beliën, A.J.C.; Botchev, M. A.; Goedbloed, J. P.; Holst,, B.; Keppens, R.

    2002-01-01

    Studying plasma waves and instabilities is an indispensable part of present thermonuclear fusion and astrophysical magnetohydrodynamics (MHD). Up till recently, spectral analysis was mostly restricted to static plasmas. However, the assumption of a static plasma is unrealistic not only for astrophysical but also for modern fusion research. Plasmas with flow have been shown to have spectra essentially different from those of static plasmas [Phys. Rev. Lett. 84 (2000) 2865]. We present two new ...

  14. The electrostatic plasma environment of a small airless body under non-aligned plasma flow and UV conditions

    Science.gov (United States)

    Poppe, A. R.; Zimmerman, M. I.; Halekas, J. S.; Farrell, W. M.

    2015-12-01

    Airless bodies interact with a wide variety of plasma environments throughout the solar system. For many objects, incident plasma is nearly co-aligned with solar ultraviolet radiation leading to the development of a positively charged dayside photoelectron sheath and a negatively charged nightside plasma sheath. Other objects, however, are present in environments where the plasma flow and solar UV radiation may not co-align. These environments include, for example, the moons of Mars as they pass through the deflected Martian magnetosheath, and many of the moons of the outer planets, which are embedded in co-rotating planetary magnetospheres. The decoupling of the plasma flow and UV incidence vectors opens up a wide range of possible surface charging and near-object plasma conditions as a function of the relative plasma-UV incidence angle. Here, we report on a series of simulations of the plasma interaction of a small body (effectively smaller than both electron and ion gyroradii) with both flowing plasma and UV radiation for different plasma-UV incidence angles using an electrostatic treecode model. We describe the plasma and electric field environment both on the object surface and in the interaction region surrounding the object, including complex surface charge and electric field distributions, interactions between surface-generated photoelectrons and ambient plasma electrons, and complex potential distributions, all of which vary as a function of the relative plasma flow-UV angle. We also show that in certain conditions, non-monotonic potential structures may exist around such objects, partially similar to those found at Earth's Moon.

  15. Experimental and numerical studies on plasma behavior flowing across perpendicular magnetic field

    Science.gov (United States)

    Takezaki, T.; Takahashi, K.; Sasaki, T.; Kikuchi, T.; Harada, N.

    2016-05-01

    To understand particle acceleration mechanisms in a collisionless shock, we have investigated the behaviors of a one-dimensional fast plasma flow in a perpendicular magnetic field by experimental and numerical simulations in a laboratory scale experiment. The velocity of the plasma flow generated by a taper-cone-shaped plasma focus device has varied by the gradient of the perpendicular magnetic field. The plasma flow has accelerated by applying the magnetic field with the negative gradient. To clarify the behavior of the plasma flow in the perpendicular magnetic field, numerical simulations based on an electromagnetic hybrid particle-in-cell (PIC) method have been carried out. These results indicate that the magnetic field gradient affects the plasma flow velocity.

  16. Do Big Bottles Kickstart Infant Weight Issues?

    Science.gov (United States)

    ... nih.gov/medlineplus/news/fullstory_159241.html Do Big Bottles Kickstart Infant Weight Issues? Smaller baby bottles ... 2016 (HealthDay News) -- Feeding babies formula from a big bottle might put them at higher risk for ...

  17. Plasma flow switch for foil-implosion experiments

    International Nuclear Information System (INIS)

    Plasma-Flow-Switch (PFS) experiments have been conducted on the 1.5 MJ Pegasus capacitor bank as a part of the opening switch development for the Los Alamos Trailmaster program. The goal of this experiment is an inductive-store, opening switch (for use with an explosive-pulsed-power generator) to drive very high energy foil implosions and generate soft x-ray pulses of ≥ 1 MJ. A shot series is underway to: (1) optimize the PFS for use on Pegasus to study foil-implosion physics issues at drive currents as high as ∼ 10 MA; (2) provide scaling and benchmarking information for the simulations used to design the PFS for explosive generators at much higher energy levels

  18. Discharge characteristics and hydrodynamics behaviors of atmospheric plasma jets produced in various gas flow patterns

    Science.gov (United States)

    Setsuhara, Yuichi; Uchida, Giichiro; Nakajima, Atsushi; Takenaka, Kosuke; Koga, Kazunori; Shiratani, Masaharu

    2015-09-01

    Atmospheric nonequilibrium plasma jets have been widely employed in biomedical applications. For biomedical applications, it is an important issue to understand the complicated mechanism of interaction of the plasma jet with liquid. In this study, we present analysis of the discharge characteristics of a plasma jet impinging onto the liquid surface under various gas flow patterns such as laminar and turbulence flows. For this purpose, we analyzed gas flow patters by using a Schlieren gas-flow imaging system in detail The plasma jet impinging into the liquid surface expands along the liquid surface. The diameter of the expanded plasma increases with gas flow rate, which is well explained by an increase in the diameter of the laminar gas-flow channel. When the gas flow rate is further increased, the gas flow mode transits from laminar to turbulence in the gas flow channel, which leads to the shortening of the plasm-jet length. Our experiment demonstrated that the gas flow patterns strongly affect the discharge characteristics in the plasma-jet system. This study was partly supported by a Grant-in-Aid for Scientific Research on Innovative Areas ``Plasma Medical Innovation'' (24108003) from the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT).

  19. Water Jets from Bottles, Buckets, Barrels, and Vases with Holes

    Science.gov (United States)

    Lopac, Vjera

    2015-01-01

    Observation of the water jets flowing from three equidistant holes on the side of a vertical cylindrical bottle is an interesting and widely used didactical experiment illustrating the laws of fluids in motion. In this paper we analyze theoretically and numerically the ranges of the stationary water jets flowing from various rotationally symmetric…

  20. Effects of Flow Shear on L-mode Plasma Confinement

    Science.gov (United States)

    Scott, S. D.; Batha, S.; Mikkelsen, D.; TFTR Team; Petty, C.

    1997-11-01

    The effect of E × B flow shear on local transport in TFTR L-mode plasmas has been studied by varying the beam net beam torque at constant density. A complete scan from pure counter-injection, to balanced injection, to pure co-injection was performed at both full field (4.8 T, 2.0 MA) and half field (2.4 T, 1.0 MA). The maximum energy confinement time, τ_E, was consistently obtained with pure co-injection while the minimum τE occurred between counter- and balanced injection. The effect of rotation on global τE was ~20% at full field and ~50% at half field. Kinetic analysis that includes calculated beam-orbit losses indicates that ion energy confinement is most affected as the net beam torque is varied while electron energy confinement is weakly affected. These trends indicate that even modest flow-shear (V_φ/cs ≈ 0.3) can have a pronounced effect on confinement, suggesting that it is a ubiquitous turbulence saturation/stabilization mechanism which should be considered in the design and analysis of confinement scaling experiments for next-step devices such as ITER.

  1. Flows and diffusions driven by neoclassical viscosities in helical plasmas

    International Nuclear Information System (INIS)

    In a previously formulated full neoclassical transport matrix for general non-symmetric toroidal plasmas, full neoclassical characteristics of magnetic configurations are described by the three mono-energetic viscosity coefficients M*(parallel viscosity against flows), N*(driving force for bootstrap currents), and L*(radial diffusion). Here we discuss on analytical expressions for these mono-energetic coefficients. Although this previous formulation has been applied to some recently designed devices to date, these applications were based on a direct numerical calculation of the linearized drift kinetic equation (LDKE). For the calculations requiring many iterative processes such as configuration optimization studies and the equilibrium calculations including the ''self-consistent bootstrap currents'', however, the analytical expressions are indispensable. To derive the expressions, the radial drift term in the LDKE is divided into two parts corresponding to the effects of local and global structures of the magnetic field. The advantages provided by this method separating the contributions of two types of trapped orbits (banana-trapped and ripple-trapped) are as follows; (1) Effects of non-bounce-averaged particle motions can be approximated by connecting results of only three types of conventional asymptotic expansions of the divided equations, i.e., banana-, plateau-, and Pfirsch-Schlueter- regime expansions, (2) N* obtained by adding the results of divided equations precisely predicts the directions of bootstrap currents and Ware pinch depending on the collisionality, (3) L* predicts ν regime of the diffusion due to the non-bounce-averaged particle motions, and so on. A simple analytical expression is derived for the ripple-trapped/untrapped boundary layer effect to the parallel viscosity force (N*) in the 1/ν regime. An existing expression of the boundary layer solution is applied to obtain the moments of the LDKE with the pitch-angle- scattering collision

  2. First Optical Observation of Intensity Dependent Laser Beam Deflection in a Flowing Plasma

    International Nuclear Information System (INIS)

    The intensity dependent deflection of a laser beam traversing an exploding foil plasma is measured for the first time. An incident f/8 probe beam exhibits deflection of up to 6 degree and angular spreading of as much as a 17 degree cone angle (f/3.3) as it exits a preformed plasma with significant plasma flow. copyright 1996 The American Physical Society

  3. Controlling hydrophilicity of polymer film by altering gas flow rate in atmospheric-pressure homogeneous plasma

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Controlling hydrophilicity of polymer film by varying gas flow rate is proposed in atmospheric-pressure homogeneous plasma treatment. • Without employing additional reactive gas, requiring more plasma power and longer treatment time, hydrophilicity of polyimide films was improved after the low-gas-flow plasma treatment. • The gas flow rate affects the hydrophilic properties of polymer surface by changing the discharge atmosphere in the particular geometry of the reactor developed. • Low-gas-flow induced wettability control suggests effective and economical plasma treatment. - Abstract: This paper reports on controlling the hydrophilicity of polyimide films using atmospheric-pressure homogeneous plasmas by changing only the gas flow rate. The gas flow changed the discharge atmosphere by mixing the feed gas with ambient air because of the particular geometry of the reactor developed for the study, and a low gas flow rate was found to be favorable because it generated abundant nitrogen or oxygen species that served as sources of hydrophilic functional groups over the polymer surface. After low-gas-flow plasma treatment, the polymer surface exhibited hydrophilic characteristics with increased surface roughness and enhanced chemical properties owing to the surface addition of functional groups. Without adding any reactive gases or requiring high plasma power and longer treatment time, the developed reactor with low-gas-flow operation offered effective and economical wettability control of polyimide films

  4. Flow dynamics and magnetic induction in the von-Karman plasma experiment

    CERN Document Server

    Plihon, Nicolas; Palermo, Francesco; Morales, Jorge A; Bos, Wouter; Godeferd, Fabien S; Bourgoin, Mickaël; Pinton, Jean-François; Moulin, M; Aanesland, Ane

    2014-01-01

    The von-Karman plasma experiment is a novel versatile experimental device designed to explore the dynamics of basic magnetic induction processes and the dynamics of flows driven in weakly magnetized plasmas. A high-density plasma column (10^16 - 10^19 particles.m^-3) is created by two radio-frequency plasma sources located at each end of a 1 m long linear device. Flows are driven through JxB azimuthal torques created from independently controlled emissive cathodes. The device has been designed such that magnetic induction processes and turbulent plasma dynamics can be studied from a variety of time-averaged axisymmetric flows in a cylinder. MHD simulations implementing volume-penalization support the experimental development to design the most efficient flow-driving schemes and understand the flow dynamics. Preliminary experimental results show that a rotating motion of up to nearly 1 km/s is controlled by the JxB azimuthal torque.

  5. Flow dynamics and magnetic induction in the von-Kármán plasma experiment

    Science.gov (United States)

    Plihon, N.; Bousselin, G.; Palermo, F.; Morales, J.; Bos, W. J. T.; Godeferd, F.; Bourgoin, M.; Pinton, J.-F.; Moulin, M.; Aanesland, A.

    2015-01-01

    The von-Kármán plasma experiment is a novel versatile experimental device designed to explore the dynamics of basic magnetic induction processes and the dynamics of flows driven in weakly magnetized plasmas. A high-density plasma column (1016-1019 particles. m-3) is created by two radio-frequency plasma sources located at each end of a 1 m long linear device. Flows are driven through J × B azimuthal torques created from independently controlled emissive cathodes. The device has been designed such that magnetic induction processes and turbulent plasma dynamics can be studied from a variety of time-averaged axisymmetric flows in a cylinder. MHD simulations implementing volume-penalization support the experimental development to design the most efficient flow-driving schemes and understand the flow dynamics. Preliminary experimental results show that a rotating motion of up to nearly 1 km/s is controlled by the J × B azimuthal torque.

  6. Simultaneous measurements of plasma flow and ion temperature using the asymmetric double probe

    International Nuclear Information System (INIS)

    The asymmetric double probe method is extended to measure not only the ion temperature but also plasma flow in the tokamak edge plasma under a strong magnetic field. The plasma flow or the Mach number is determined by the ratio of ion saturation currents of the double probe pins, where the axes of the cylindrical pins are oriented perpendicular to the magnetic field and face up-or downstream. An experiment was performed in the JFT-2M tokamak. (author)

  7. Numerical Simulation of Flow Separation Control using Multiple DBD Plasma Actuators

    OpenAIRE

    Roohallah Khoshkhoo; Alireza Jahangirian

    2016-01-01

    A numerical simulation method is employed to investigate the effect of the steady multiple plasma body forces on the flow field of stalled NACA 0015 airfoil. The plasma body forces created by multiple Dielectric Barrier Discharge (DBD) actuators are modeled with a phenomenological plasma method coupled with 2-dimensional compressible turbulent flow equations. The body force distribution is assumed to vary linearly in the triangular region around the actuator. The equations are solved using ad...

  8. Plasma Flow and Temperature in a Gliding Reactor with Different Electrode Configurations

    OpenAIRE

    Sláma, J.

    2012-01-01

    This paper deals with the plasma flow shape depending on the electrode form of a gliding discharge plasma-chemical reactor, and with the temperature distribution along the direction of the plasma flow in one specific electrode form. The shape of the electrodes and their mutual position has a significant influence on the design of a gliding discharge reactor and its applications. It is crucial to know the temperature distribution in the reactor’s chamber design and discharge application. Three...

  9. On the energy transfer between flows and turbulence in the plasma boundary of fusion devices

    International Nuclear Information System (INIS)

    The energy transfer between perpendicular flows and turbulence has been investigated in the JET plasma boundary region. The energy transfer from DC flows to turbulence, directly related with the momentum flux (e.g. θv-barr>) and the radial gradient in the flow, can be both positive and negative in the proximity of sheared flows. The direct computation of the turbulent viscosity gives values comparable to the anomalous particle diffusivitiy (in the order of 1m2/s). Furthermore, this energy transfer rate is comparable with the mean flow kinetic energy normalized to the correlation time of turbulence, implying that this energy transfer is significant. These results show, for the first time, the dual role of turbulence as a damping (eddy viscosity) and driving of flows in fusion plasmas emphasizing the important role of turbulence to understand perpendicular dynamics in the plasma boundary region of fusion plasmas

  10. Effect of plasma exchange on blood viscosity and cerebral blood flow.

    OpenAIRE

    Brown, M M; Marshall, J

    1982-01-01

    The effects of plasma exchange using a low viscosity plasma substitute on blood viscosity and cerebral blood flow were investigated in eight subjects with normal cerebral vasculature. Plasma exchange resulted in significant reductions in plasma viscosity, whole blood viscosity, globulin and fibrinogen concentration without affecting packed cell volume. The reduction in whole blood viscosity was more pronounced at low shear rates suggesting an additional effect on red cell aggregation. Despite...

  11. Generation of electromagnetic emission during the injection of dense supersonic plasma flows into arched magnetic field

    Science.gov (United States)

    Viktorov, Mikhail; Golubev, Sergey; Mansfeld, Dmitry; Vodopyanov, Alexander

    2016-04-01

    Interaction of dense supersonic plasma flows with an inhomogeneous arched magnetic field is one of the key problems in near-Earth and space plasma physics. It can influence on the energetic electron population formation in magnetosphere of the Earth, movement of plasma flows in magnetospheres of planets, energy release during magnetic reconnection, generation of electromagnetic radiation and particle precipitation during solar flares eruption. Laboratory study of this interaction is of big interest to determine the physical mechanisms of processes in space plasmas and their detailed investigation under reproducible conditions. In this work a new experimental approach is suggested to study interaction of supersonic (ion Mach number up to 2.7) dense (up to 1015 cm‑3) plasma flows with inhomogeneous magnetic field (an arched magnetic trap with a field strength up to 3.3 T) which opens wide opportunities to model space plasma processes in laboratory conditions. Fully ionized plasma flows with density from 1013 cm‑3 to 1015 cm‑3 are created by plasma generator on the basis of pulsed vacuum arc discharge. Then plasma is injected in an arched open magnetic trap along or across magnetic field lines. The filling of the arched magnetic trap with dense plasma and further magnetic field lines break by dense plasma flow were experimentally demonstrated. The process of plasma deceleration during the injection of plasma flow across the magnetic field lines was experimentally demonstrated. Pulsed plasma microwave emission at the electron cyclotron frequency range was observed. It was shown that frequency spectrum of plasma emission is determined by position of deceleration region in the magnetic field of the magnetic arc, and is affected by plasma density. Frequency spectrum shifts to higher frequencies with increasing of arc current (plasma density) because the deceleration region of plasma flow moves into higher magnetic field. The observed emission can be related to the

  12. Radial-flow plasma reactors: fluid-dynamic and transport studies

    International Nuclear Information System (INIS)

    Fluid dynamics in radial-flow plasma reactors was investigated by suitably idealizing the reactor geometry and by employing the complete elliptic forms of the Navier-Stokes equation. No evidence of flow separation was observed in the low Reynolds number limit. Flow separation was seen first at a Reynolds number of 10 and an aspect ratio of 2. The separated region consists of a single clockwise vortex at all Reynolds numbers and aspect ratios. It was also seen that even at low Reynolds numbers and small aspect ratios the field between the circular plates beyond one pipe radius is not influenced significantly by the application of boundary layer arguments to the flow within the pipe. In the Stokes flow limit the flow field was also calculated analytically by partitioning the flow domain into two regions and subsequently matching the two different solutions at the dividing plane. The flow field calculated numerically was employed in the analysis of two plasma processes in radial-flow reactions: the etching of a photoresist in an oxygen plasma and the etching of SiO2 in a CF4 plasma. In each case the analysis was performed by combining the plasma chemistry and the plasma structure with a model for the transport-reaction phenomena occurring within the reactor

  13. Generation of electromagnetic emission during the injection of dense supersonic plasma flows into arched magnetic field

    Science.gov (United States)

    Mansfeld, Dmitry; Golubev, Sergey; Viktorov, Mikhail; Vodopyanov, Alexander; Yushkov, George

    2015-11-01

    Interaction of dense supersonic plasma flows with an inhomogeneous arched magnetic field is one of the key problems in near-Earth and space plasma physics. In this work a new experimental approach is suggested to study interaction of supersonic (ion Mach number up to 2.7) dense (up to 1015cm-3) plasma flows with inhomogeneous magnetic field (an arched magnetic trap with a field strength up to 3.3 T) which opens wide opportunities to model space plasma processes in laboratory conditions. Fully ionized plasma flows with density from 1013cm-3 to 1015cm-3 are created by plasma generator on the basis of pulsed vacuum arc discharge and injected into open magnetic trap across magnetic field lines. The filling of the arched magnetic trap with plasma and further magnetic field lines break by dense plasma flow was accompanied by pulsed electromagnetic emission at electron cyclotron frequency range, which can generated by electrons in the place of intensive deceleration of plasma flow in magnetic field. Grant of Ministry of Education 14.Z50.31.0007.

  14. Plasma Flow and Temperature in a Gliding Reactor with Different Electrode Configurations

    Directory of Open Access Journals (Sweden)

    J. Sláma

    2012-01-01

    Full Text Available This paper deals with the plasma flow shape depending on the electrode form of a gliding discharge plasma-chemical reactor, and with the temperature distribution along the direction of the plasma flow in one specific electrode form. The shape of the electrodes and their mutual position has a significant influence on the design of a gliding discharge reactor and its applications. It is crucial to know the temperature distribution in the reactor’s chamber design and discharge application. Three configurations with model shapes of wire electrodes were therefore tested (low-divergent, circular, high-divergent and the plasma flow was described. The experiments were performed in air at atmospheric pressure and at room temperature. In order to map the reactive plasma region of the flow we investigated the visible spectral lines that were emitted. The gas temperature was measured using an infrared camera.

  15. Cross-field flow of plasma produced by laser resonance photoionization

    International Nuclear Information System (INIS)

    A slow(v≅700m/s) neodymium plasma was produced by laser resonance photoionization in a transverse magnetic field of up to 2240G. The plasma density was in the range of 7.5 x 107 - 1.7 x 109cm-3. The high-density plasma in the low magnetic field flowed straight and was detected by a planar collector set 60mm downstream from the position of plasma production. On the contrary, the low-density plasma did not flow straight across the high magnetic field. The ion numbers detected by the collector decreased and arrival time to the collector delayed. It was found that the ratio of the ions detected by the collector to those produced by laser beams and the arrival times were functions of the plasma relative dielectric constant εr in the wide ranges of plasma density and magnetic field. When εr >1000, the plasma flowed straight across the magnetic field. Therefore it was concluded that the lowest value of εr for the very slow plasma flow in the transverse magnetic field is also consistent with the theoretical prediction εr >(M/m)1/2 =513 for neodymium plasma, where M/m is the mass ratio of the ion to the electron. (author)

  16. Development of a FE method for modelling plasma flows in tokamak plasma edges

    International Nuclear Information System (INIS)

    The purpose of the work is to to develop a two-dimensional Finite-Element-Code. This code should be able to simulate the plasma flow pattern in the burning chamber of fusion devices by an exact and solution-dependent discretisation. Reionisation and other collision processes of recycled neutral particles are described by coupling the fluid model to the kinetic Monte-Carlo neutral-gas-code EIRENE. For comparison and fundamental numerical studies a fast analytical description of recycling is also available. Such rather crude approximations are employed in other codes often as the only option. It is possible to treat the flow of ions and neutral atoms/molecules near complex surface structures of fusion devices consistently. Because of the time step restriction in the special solution algorithm, up to now the electron temperature profile has to be provided from elsewhere. It can, for example be interpolated from experimental data or from results of other independent code calculations. The newly developed code is applied to a typical TOKAMAK-discharge (TEXTOR) and characteristic results are discussed. (orig./HP)

  17. Plasma flow crisis and limiting electron temperature in a vacuum arc and in axial magnetic field

    International Nuclear Information System (INIS)

    One studied possibility of supersonic motion of cathode plasma in a weak-current vacuum arc placed in axial magnetic field. Increase of electron temperature is shown to result inevitably in reduction of plasma speed up to sonic speed, that is, flow crisis. One derived dependence of the boundary length of plasma stationary flow on magnetic field. The maximum attainable electron temperature of plasma was determined to be governed by ion initial energy and to be equal to the triple value of electron temperature within cathode spot range

  18. Modification of structural materials by pulsed plasma flows

    International Nuclear Information System (INIS)

    Features of surface modification and materials alloying from gas and metallic plasma as a result of the plasma ions mixing with the steel substrate in liquid phase are investigated in this paper.The experiments have been carried out with pulsed plasma gun, which generates plasma streams with ion energy up to 2 keV, plasma density 2x1014 cm-3, average specific power of 10 MW/cm2 and plasma energy density in the range of (5-40) J/cm2. The nitrogen, helium, other gases and their mixtures can be used as working gases. The regime of plasma treatment was chosen with variation of both the discharge voltage and the distance of the material surface from the gun output. Modification of thin (0.5-2 µm) PVD coatings of MoN, C+W, TiN, TiC, Cr, Cr+CrN and others by the pulsed plasma streams are analyzed also. It is shown that pulsed plasma treatment results in essential improvement of physical and mechanical properties of exposed materials. For example, microhardness of samples with Cr coating, after plasma treatment, increased in 2,5 times. Mechanisms of surface modification of a different alloys and coating irradiated with pulsed plasma streams of different ions are discussed. (authors)

  19. Ocular injuries from flying bottle caps.

    Science.gov (United States)

    Fonseka, C

    1993-12-01

    Three cases of serious eye injury are described from flying metal caps of carbonated drink bottles. The injuries occurred while attempting to open the bottle in an unconventional and dangerous way. Though injuries from flying bottle caps have been described before, they have occurred when the bottle exploded. This is the first report of eye injuries caused by bottle caps while opening and are similar to the injuries caused by champagne corks. PMID:8143337

  20. Formation of the compression zone in a plasma flow generated by a magnetoplasma compressor

    International Nuclear Information System (INIS)

    Processes occurring in a plasma flow generated by a magnetoplasma compressor (MPC) during the formation of the compression zone are discussed. The paper presents results of measurements of the spatial distribution of the electric current in the plasma flow, the temporal and spatial (along the flow) distributions of the plasma density, and the profiles of the velocity of individual flow layers along the system axis. The spatial distribution of the electromagnetic force in the flow is analyzed. It is shown that the plasma flow is decelerated when approaching the compression zone and reaccelerated after passing it. In this case, the plasma flow velocity decreases from ν = (2–3) × 107 cm/s at the MPC output to ν 6 cm/s in the region of maximum compression and then again increases to 107 cm/s at a distance of 15–17 cm from the MPC output. In some MPC operating modes, a displacement of the magnetic field from the compression zone and the formation of toroidal electric current vortices in the plasma flow after passing the compression zone were detected

  1. Formation of the compression zone in a plasma flow generated by a magnetoplasma compressor

    Energy Technology Data Exchange (ETDEWEB)

    Solyakov, D. G., E-mail: solyakov@ipp.kharkov.ua; Petrov, Yu. V.; Garkusha, I. E.; Chebotarev, V. V.; Ladygina, M. S.; Cherednichenko, T. N.; Morgal’, Ya. I.; Kulik, N. V.; Stal’tsov, V. V.; Eliseev, D. V. [National Academy of Sciences of Ukraine, Institute of Plasma Physics, National Science Center Kharkiv Institute of Physics and Technology (Ukraine)

    2013-12-15

    Processes occurring in a plasma flow generated by a magnetoplasma compressor (MPC) during the formation of the compression zone are discussed. The paper presents results of measurements of the spatial distribution of the electric current in the plasma flow, the temporal and spatial (along the flow) distributions of the plasma density, and the profiles of the velocity of individual flow layers along the system axis. The spatial distribution of the electromagnetic force in the flow is analyzed. It is shown that the plasma flow is decelerated when approaching the compression zone and reaccelerated after passing it. In this case, the plasma flow velocity decreases from ν = (2–3) × 10{sup 7} cm/s at the MPC output to ν < 10{sup 6} cm/s in the region of maximum compression and then again increases to 10{sup 7} cm/s at a distance of 15–17 cm from the MPC output. In some MPC operating modes, a displacement of the magnetic field from the compression zone and the formation of toroidal electric current vortices in the plasma flow after passing the compression zone were detected.

  2. Beers Straight from the Bottle

    OpenAIRE

    Murphy, James Peter

    2007-01-01

    Consuming beer straight from the bottle a trend initiated by the US is now an accepted practice throughout Irish bars but that does not necessarily mean it is a good thing from either a hygiene or taste viewpoint.

  3. Enhanced nonlinear iterative techniques applied to a nonequilibrium plasma flow

    International Nuclear Information System (INIS)

    The authors study the application of enhanced nonlinear iterative methods to the steady-state solution of a system of two-dimensional convection-diffusion-reaction partial differential equations that describe the partially ionized plasma flow in the boundary layer of a tokamak fusion reactor. This system of equations is characterized by multiple time and spatial scales and contains highly anisotropic transport coefficients due to a strong imposed magnetic field. They use Newton's method to linearize the nonlinear system of equations resulting from an implicit, finite volume discretization of the governing partial differential equations, on a staggered Cartesian mesh. The resulting linear systems are neither symmetric nor positive definite, and are poorly conditioned. Preconditioned Krylov iterative techniques are employed to solve these linear systems. They investigate both a modified and a matrix-free Newton-Krylov implementation, with the goal of reducing CPU cost associated with the numerical formation of the Jacobian. A combination of a damped iteration, mesh sequencing, and a pseudotransient continuation technique is used to enhance global nonlinear convergence and CPU efficiency. GMRES is employed as the Krylov method with incomplete lower-upper (ILU) factorization preconditioning. The goal is to construct a combination of nonlinear and linear iterative techniques for this complex physical problem that optimizes trade-offs between robustness, CPU time, memory requirements, and code complexity. It is shown that a mesh sequencing implementation provides significant CPU savings for fine grid calculations. Performance comparisons of modified Newton-Krylov and matrix-free Newton-Krylov algorithms will be presented

  4. Multidirectional plasma flow measurement by Gundestrup Probe in scrape-off layer of ADITYA tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Sangwan, Deepak; Jha, Ratneshwar; Tanna, Rakesh L. [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India)

    2015-11-15

    Multidirectional plasma flow measurements by using Gundestrup Probe in the scrape-off layer of ADITYA tokamak are presented. The ADITYA Gundestrup Probe-head consists of eight plates arranged around the ceramic rod and three pins normal to side plates. Plates are used to measure both parallel and perpendicular flows simultaneously and pins are used to measure plasma density and floating potential. A comparison of direct perpendicular flow measurement and by two other plates of Gundestrup Probe is presented. Possible causes of perpendicular flows are identified and compared with the measured flows. It is observed that the mechanism of the parallel flow and the perpendicular flow is different only at high parallel Mach number. A puff of the working gas is used to study its effect on the perpendicular flows and its reversal with the gas puff is observed.

  5. Sharp collimation of plasma flow from planar targets

    Czech Academy of Sciences Publication Activity Database

    Kmetík, Viliam; Kuchařík, M.; Limpouch, J.; Liska, R.; Váchal, P.

    Budapešť: National Office for Research and Technology, 2010 - (FÖLDES, I.). 01-01 ISBN N. [European Conference on Laser Interaction with Matter/31st./. 06.09.2010-10.09.2010, Budapešť] Institutional research plan: CEZ:AV0Z20430508 Keywords : Laser plasma * plasma jet Subject RIV: BL - Plasma and Gas Discharge Physics http://top-congress.hu/2010/eclim/index_1.htm

  6. New method of initiating multi-megampere, multi-megajoule plasma focus discharges using magnetized plasma flow switches

    International Nuclear Information System (INIS)

    Plasma focus discharges have historically produced copious neutrons or x-rays at moderate energies and with high efficiency. The optimized output scaling for both neutrons and x-rays has followed an approximate power law in current up to currents of order one megampere and stored capacitor energy of order one megajoule. However, this favorable scaling has not successfully been extended beyond these levels. Conventional plasma foci are initiated by a high-current, low-inductance discharge through a static gas prefill which lifts off an insulator. One serious problem for high-energy operation is restrike across the initiation insulator, caused by a combination of ultraviolet photons from the plasma current sheath and rather large inductive voltages during the subsequent run-down and implosion phases. The result is current shunting and loss of drive pressure for the pinch. An alternative scheme involves a plasma flow switch (PFS), in which a conducting plasma armature convects toroidal magnetic flux to a downstream load. The authors describe a novel dense plasma focus experiment at the Shiva Star facility which uses a compact toroid (CT) magnetized plasma flow switch to initiate the focus implosion downstream from a shielded vacuum insulator

  7. Cross-tail velocity component in the plasma sheet fast flows

    Directory of Open Access Journals (Sweden)

    N. P. Dmitrieva

    2008-06-01

    Full Text Available The flux transfer in the magnetotail plasma sheet is mainly provided by the tail-aligned fast plasma flows (Bursty Bulk Flows – BBFs. In this paper we study the events with a large cross-tail velocity component, including their occurrence and relationship to the standard BBFs. We found out that a significant part of large Vy events are a subgroup connected with the BBFs propagation. The maximal deviation of the velocity vector from the X direction (about 40–50 degrees, on average is observed near the BBFs' leading front in the sheath, where the fast flow interacts with surrounding plasma. The average variation of the velocity direction in the vicinity of the BBF resembles a plasma vortex. Our results support the model, in which the BBF represents a polarized, bubble-like flux tube, propagating through the plasma sheet.

  8. Flow shear induced fluctuation suppression in finite aspect ratio shaped tokamak plasma

    International Nuclear Information System (INIS)

    The suppression of turbulence by the E x B flow shear and parallel flow shear is studied in an arbitrary shape finite aspect ratio tokamak plasma using the two point nonlinear analysis previously utilized in a high aspect rat ampersand tokamak plasma. The result shows that only the E x B flow shear is responsible for the suppression of flute-like fluctuations. This suppression occurs regardless of the plasma rotation direction and is therefore, relevant for the VH mode plasma core as well as for the H mode plasma edge. Experimentally observed in-out asymmetry of fluctuation reduction behavior can be addressed in the context of flux expansion and magnetic field pitch variation on a given flux surface. The adverse effect of neutral particles on confinement improvement is also discussed in the context of the charge exchange induced parallel momentum damping

  9. Voyager 2 Observations of Plasmas and Flows out to 104 AU

    Science.gov (United States)

    Richardson, J. D.; Decker, R. B.

    2014-09-01

    Voyager 2 has crossed through 20 AU of the heliosheath; assuming the same heliosheath thickness as at Voyager 1, it is now two-thirds of the way to the heliopause. The plasma data are generally of good quality, although the increasing flow angle of the plasma makes analysis more difficult. The average plasma speed has remained constant but the flow angles have increased to almost 60° in the RT plane and to almost 30° in the RN plane. The average density and thermal speed have been constant since a density increase observed in 2011. Comparison of V2 plasma flows derived from plasma science experiment (PLS) data and Low Energy Charged Particle (LECP) proton anisotropies give good agreement except when heavy ion contributions or non-convective proton anisotropies are observed in the LECP data.

  10. Voyager 2 observations of plasmas and flows out to 104 AU

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, J. D. [Kavli Center for Astrophysics and Space Science, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Decker, R. B., E-mail: jdr@space.mit.edu, E-mail: robert.decker@apljhu.edu [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD (United States)

    2014-09-10

    Voyager 2 has crossed through 20 AU of the heliosheath; assuming the same heliosheath thickness as at Voyager 1, it is now two-thirds of the way to the heliopause. The plasma data are generally of good quality, although the increasing flow angle of the plasma makes analysis more difficult. The average plasma speed has remained constant but the flow angles have increased to almost 60° in the RT plane and to almost 30° in the RN plane. The average density and thermal speed have been constant since a density increase observed in 2011. Comparison of V2 plasma flows derived from plasma science experiment (PLS) data and Low Energy Charged Particle (LECP) proton anisotropies give good agreement except when heavy ion contributions or non-convective proton anisotropies are observed in the LECP data.

  11. Influence of ExB shear flows on plasma edge turbulence

    International Nuclear Information System (INIS)

    Poloidal ExB shear flows are widely accepted as a trigger mechanism of transport barriers in the edge of fusion plasmas. Strong ExB flows can act on turbulence and turbulent transport through the shear decorrelation mechanism, which can reduce the radial size of turbulent structures or change the phase relation between density and potential fluctuations. In this contribution the influence of ExB shear flows on the microscopic structure of turbulence is investigated. The experiments have been carried out on the toroidally confined low-temperature plasma of the torsatron TJ-K. The plasma is dimensionally similar to fusion edge plasmas and accessible throughout for Langmuir probes. Multi-probe arrays are used to resolve the turbulent dynamics perpendicular to the confining magnetic field in high detail.Strong ExB flows are externally generated by core plasma biasing. It is shown that the fluctuations are dominated by large-scale coherent structures even though strong flow shear is present. These structures reveal increased correlation lengths. It is found that these structures can contribute to improved confinement through inwards transport due to cross-phase modifications. Furthermore, the response of the turbulent Reynolds stress, which is supposed to drive zonal flows as internally ExB shear flows, is investigated. The externally generated flow shear leads to a redistribution of the Reynolds stress with increased poloidal symmetry

  12. Plasma flow and a soliton in a theta pinch

    International Nuclear Information System (INIS)

    The present paper deals with a weakly nonlinear wave propagating along a slender magnetized plasma of high β and shows that a compressive area-wave as well as a rarefaction wave propagates into the plasma due to the mirror effect. The steepening of the compression wave is balanced with a dispersion caused by a radial motion and a solitary wave is formed. (author)

  13. The Excitation of the Low-Frequency Electromagnetic Wave in Dusty Plasma with Vortex Flows

    Institute of Scientific and Technical Information of China (English)

    MA Jun; CHEN Yinhua

    2007-01-01

    The Excitation of Alfven wave in dusty plasma with vortex flows is investigated. The coupled equations for density and electromagnetic potential of dusty plasma with vortex-flow were obtained. The stability and amplitude behavior were studied both analytically and numerically. Using a non-modal method, it was found that the presence of dust can suppress the growth of the instability which can also be affected by the vortex eccentricity.

  14. The Langmuir probe measurement of flow velocity in a flame plasma

    International Nuclear Information System (INIS)

    A method of measuring the flow velocity in a flame or other collision dominated plasma is described. It is based on the velocity characteristic of a Langmuir probe which is swept through the plasma. The probes were operated in the sheath-convection regime and exhibited a systematic variation between thin and thick sheath behavior which was attributed to an expanding sheath as the plasma-probe conditions were varied. (author)

  15. Plasma-liquid system with reverse vortex flow of 'tornado' type (TORNADO-LE)

    International Nuclear Information System (INIS)

    The results of experimental investigations of the plasma in plasma-liquid system with reverse vortex flow of 'tornado' type are presented. Volt-ampere characteristic of discharge in the current range from 200 to 400 mA were measured. Emission spectra of plasma in range from 200 to 1100 nm were measured. Excitation temperatures (electronic Te*, vibrational Tv* and rotational Tr*) were obtained. Emission spectra of hydroxyl OH were calculated.

  16. Magnetically confined plasma solar collector. [satellite based system in space

    Science.gov (United States)

    Walters, C. T.; Wolken, G., Jr.; Purvis, G. D., III

    1978-01-01

    The possibility of using a plasma medium for collecting solar energy in space is examined on the basis of a concept involving an orbiting magnetic bottle in which a solar-energy-absorbing plasma is confined. A basic system uses monatomic cesium as working fluid. Cesium evaporates from a source and flows into the useful volume of a magnetic bottle where it is photoionized by solar radiation. Ions and electrons lost through the loss cones are processed by a recovery system, which might be a combination of electromagnetic devices and heat engines. This study concentrates on the plasma production processes and size requirements, estimates of the magnetic field required to confine the plasma, and an estimate of the system parameters for a 10 GW solar collector using cesium.

  17. Modified ion-acoustic solitary waves in plasmas with field-aligned shear flows

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, H. [Department of Space Science, Institute of Space Technology, 1-Islamabad Highway, Islamabad (Pakistan); Theoretical Research Institute, Pakistan Academy of Sciences, 3-Constitution Avenue G-5/3, Islamabad (Pakistan); Ali, S. [Theoretical Research Institute, Pakistan Academy of Sciences, 3-Constitution Avenue G-5/3, Islamabad (Pakistan); National Centre for Physics (NCP) at Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Haque, Q. [Theoretical Research Institute, Pakistan Academy of Sciences, 3-Constitution Avenue G-5/3, Islamabad (Pakistan); National Centre for Physics (NCP) at Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Theoretical Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2015-08-15

    The nonlinear dynamics of ion-acoustic waves is investigated in a plasma having field-aligned shear flow. A Korteweg-deVries-type nonlinear equation for a modified ion-acoustic wave is obtained which admits a single pulse soliton solution. The theoretical result has been applied to solar wind plasma at 1 AU for illustration.

  18. Modified ion-acoustic solitary waves in plasmas with field-aligned shear flows

    International Nuclear Information System (INIS)

    The nonlinear dynamics of ion-acoustic waves is investigated in a plasma having field-aligned shear flow. A Korteweg-deVries-type nonlinear equation for a modified ion-acoustic wave is obtained which admits a single pulse soliton solution. The theoretical result has been applied to solar wind plasma at 1 AU for illustration

  19. Bottled drinking water: Water contamination from bottle materials (glass, hard PET, soft PET), the influence of colour and acidification

    International Nuclear Information System (INIS)

    A test comparing concentrations of 57 chemical elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Ho, I, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Se, Sm, Sn, Sr, Ta, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn and Zr) determined by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) in 294 samples of the same bottled water (predominantly mineral water) sold in the European Union in glass and PET bottles demonstrates significant (Wilcoxon rank sum test, α = 0.05) differences in median concentrations for Sb, Ce, Pb, Al, Zr, Ti, Th, La, Pr, Fe, Zn, Nd, Sn, Cr, Tb, Er, Gd, Bi, Sm, Y, Lu, Dy, Yb, Tm, Nb and Cu. Antimony has a 21x higher median value in bottled water when sold in PET bottles (0.33 vs. 0.016 μg/L). Glass contaminates the water with Ce (19x higher than in PET bottles), Pb (14x), Al (7x), Zr (7x), Ti, Th (5x), La (5x), Pr, Fe, Zn, Nd, Sn, Cr, Tb (2x), Er, Gd, Bi, Sm, Y, Lu, Yb, Tm, Nb and Cu (1.4x). Testing an additional 136 bottles of the same water sold in green and clear glass bottles demonstrates an important influence of colour, the water sold in green glass shows significantly higher concentrations in Cr (7.3x, 1.0 vs. 0.14 μg/L), Th (1.9x), La, Zr, Nd, Ce (1.6x), Pr, Nb, Ti, Fe (1.3x), Co (1.3x) and Er (1.1x). One hundred and twenty-six bottles of three different materials (glass, hard PET and soft PET) in 5 principal colours (clear, light and dark green and blue, brown) were subsequently washed and then filled with high purity water (18.2 MΩ cm). A portion of the bottles where left at the original average pH of the water (pH 6.5) while the remaining bottles were acidified to pH 3.5 with HNO3. Concentrations of the same 57 elements as above were determined after 1, 2, 3, 4, 5, 15, 30, 56, 80 and 150 days of leaching. Results substantiate the observations from the direct comparison of the same water sold in different bottle types (colour). For most elements leaching is

  20. Controlling hydrophilicity of polymer film by altering gas flow rate in atmospheric-pressure homogeneous plasma

    Science.gov (United States)

    Kang, Woo Seok; Hur, Min; Lee, Jae-Ok; Song, Young-Hoon

    2014-03-01

    This paper reports on controlling the hydrophilicity of polyimide films using atmospheric-pressure homogeneous plasmas by changing only the gas flow rate. The gas flow changed the discharge atmosphere by mixing the feed gas with ambient air because of the particular geometry of the reactor developed for the study, and a low gas flow rate was found to be favorable because it generated abundant nitrogen or oxygen species that served as sources of hydrophilic functional groups over the polymer surface. After low-gas-flow plasma treatment, the polymer surface exhibited hydrophilic characteristics with increased surface roughness and enhanced chemical properties owing to the surface addition of functional groups. Without adding any reactive gases or requiring high plasma power and longer treatment time, the developed reactor with low-gas-flow operation offered effective and economical wettability control of polyimide films.

  1. Heat transfer to a spherical particle in a flowing plasma

    Energy Technology Data Exchange (ETDEWEB)

    Nemchinsky, Valerian, E-mail: nemchinsky@bellsouth.ne [Keiser University, Fort Lauderdale, FL (United States)

    2010-06-02

    Heat flux to a sphere moving in a high-pressure plasma is considered. The sphere is electrically insulated and it is at floating potential. Numerical calculations are performed for conditions typical for plasma arc spraying: the sphere diameter is from tens to hundreds of micrometres, its velocity is on the order of hundreds of metres per second, plasma gas-argon of atmospheric pressure. It is shown that (a) the standard gas-dynamic method to calculate, Q, heat flux to a sphere Q = {kappa}R{Delta}TNu, Nu = 2 + 0.6Re{sup 1/2}Pr{sup 1/3} does not describe Q correctly because it grossly overestimates heat conduction by electrons ({kappa} is the total plasma thermal conductivity, R is the particle radius, {Delta}T is the temperature difference between plasma and the particle, Nu, Re and Pr are Nusselt, Reynolds and Prandtl numbers, respectively); (b) heat flux is not evenly distributed over the particle's surface: the side of the particle that faces the upstream plasma is more heated than the opposite side and (c) ionization in the particle proximity could be important under conditions typical for plasma arc spraying.

  2. Generation Control of ZnO Nanoparticles Using a Coaxial Gas-Flow Pulse Plasma Ar/O2 Plasma

    Directory of Open Access Journals (Sweden)

    Hiroki Shirahata

    2015-01-01

    Full Text Available Generation of ZnO nanoparticles was investigated using a coaxial gas-flow pulse plasma. We studied how zinc atoms, sputtered from a zinc target, reacted with oxygen in a plasma and/or on a substrate to form ZnO nanoparticles when the discharge parameters, such as applied pulse voltage and gas flow rate, were controlled in an O2/Ar plasma. The formation processes were estimated by SEM, TEM, and EDX. We observed many ZnO nanoparticles deposited on Si substrate. The particle yield and size were found to be controlled by changing the experimental parameters. The diameter of the particles was typically 50–200 nm.

  3. On the plasma flow inside magnetic tornadoes on the Sun

    OpenAIRE

    Wedemeyer, Sven; Steiner, Oskar

    2014-01-01

    High-resolution observations with the Swedish 1-m Solar Telescope (SST) and the Solar Dynamics Observatory (SDO) reveal rotating magnetic field structures that extend from the solar surface into the chromosphere and the corona. These so-called magnetic tornadoes are primarily detected as rings or spirals of rotating plasma in the Ca II 854.2 nm line core (also known as chromospheric swirls). Detailed numerical simulations show that the observed chromospheric plasma motion is caused by the rot...

  4. A Plastic Bottle in Rectosigmoid

    Directory of Open Access Journals (Sweden)

    A. Derakhshanfar

    2007-07-01

    Full Text Available Introduction: Evaluation and treatment of foreign bodies in rectum involves careful history and physical examination. The cases of forced introduction of the objects most commonly are , sexual assault , self – introduced for anal eroticism and accidental insertion.Case Report: We describe a case of a patient with rectal impaction following self administration of a plastic bottle for anal sexual gratification. A 49 years old man was admitted in the emergency department with the history of self introduced a bottle into his rectum physical examination and abdominal X-Ray diagnosed the case as impacted foreign body in rectosigmoid. An attempt was made to deliver the bottle through the rectum but because of high lying big bottle in the sigmoid laporotomy was performed and the bottle was removed though a longitudinal incision on sigmoid colon.Conclusion: Retained rectosigmoid foreign bodies have been encountered more frequently and present a dilemma for management and rarely laporotomy for extraction of foreign bodies was performed.

  5. Magnetic Flux Transport and Pressure Variations at Magnetotail Plasma Flow Bursts during Geomagnetically Quiet Times

    Science.gov (United States)

    Nowada, M.; Fu, S.-Y.; Parks, G. K.; Pu, Z.-Y.; Angelopoulos, V.; Carlson, C. W.; Auster, H.-U.

    2012-04-01

    The fast plasma flows in the geomagnetotail are observed during both geomagnetically active and quiet times. However, it has been unclear about the fundamental difference in the plasma fast flows between at two different geomagnetic conditions, that is, the generation mechanism of, and pictures of the energy transport and balance at the fast plasma flows. Magnetic reconnection in the magnetotail has been believed as one of the most possible mechanisms to generate the fast plasma flows regardless of the geomagnetic conditions. Recently, Nowada et al. [2012], however, demonstrated that the magnetotail magnetic reconnection does not always contribute to the generation of the fast plasma flows at geomagnetically quiet times based on the THEMIS measurements. It is very important to reveal how the energy transport and balance in the magnetotail in association with these plasma fast flows are on obtaining a clue to elucidate an essential difference in the plasma fast flows between during active and quiet geomagnetic conditions. Based on three events of the magnetotail plasma flow bursts, which are transient fast plasma flows with the durations between 1 and 2 minutes, during geomagnetically quiet times, observed by THEMIS, we examined detailed variations of the electric field as a proxy of the flux transport aspect, and associated pressure. The main characteristics of these events are shown as follows; 1) the GSM-X component of the plasma velocity (Vx) was higher than 300 km/s 2) associated parallel (V//) and perpendicular (V⊥) velocities to the local magnetic field line were higher than 200 km/s 3) the flow bursts were observed during which AL and AU indices were lower than 40 nT, and simultaneous Kp index range was between -1 and 1. For almost events, the parallel (E//) and perpendicular (E⊥) components of the electric field to the local magnetic field line were much stronger than the dawn-dusk electric field component (Ey). This result implies that a larger amount

  6. Numerical Simulation of Non-Equilibrium Plasma Discharge for High Speed Flow Control

    Science.gov (United States)

    Balasubramanian, Ramakrishnan; Anandhanarayanan, Karupannasamy; Krishnamurthy, Rajah; Chakraborty, Debasis

    2016-06-01

    Numerical simulation of hypersonic flow control using plasma discharge technique is carried out using an in-house developed code CERANS-TCNEQ. The study is aimed at demonstrating a proof of concept futuristic aerodynamic flow control device. The Kashiwa Hypersonic and High Temperature wind tunnel study of plasma discharge over a flat plate had been considered for numerical investigation. The 7-species, 18-reaction thermo-chemical non-equilibrium, two-temperature air-chemistry model due Park is used to model the weakly ionized flow. Plasma discharge is modeled as Joule heating source terms in both the translation-rotational and vibrational energy equations. Comparison of results for plasma discharge at Mach 7 over a flat plate with the reference data reveals that the present study is able to mimic the exact physics of complex flow such as formation of oblique shock wave ahead of the plasma discharge region with a resultant rise in surface pressure and vibrational temperature up to 7000 K demonstrating the use of non-equilibrium plasma discharge for flow control at hypersonic speeds.

  7. Computational study of flow dynamics from a dc arc plasma jet

    CERN Document Server

    Trelles, Juan Pablo

    2013-01-01

    Plasma jets produced by direct-current (DC) non-transferred arc plasma torches, at the core of technologies ranging from spray coating to pyrolysis, present intricate dynamics due to the coupled interaction of fluid flow, thermal, and electromagnetic phenomena. The flow dynamics from an arc discharge plasma jet are investigated using time-dependent three-dimensional simulations encompassing the dynamics of the arc inside the torch, the evolution of the jet through the discharge environment, and the subsequent impingement of the jet over a flat substrate. The plasma is described by a chemical equilibrium and thermodynamic nonequilibrium (two-temperature) model. The numerical formulation of the physical model is based on a monolithic and fully-coupled treatment of the fluid and electromagnetic equations using a Variational Multiscale Finite Element Method. Simulation results uncover distinct aspects of the flow dynamics, including the jet forcing due to the movement of the electric arc, the prevalence of deviat...

  8. Plasma sheet fast flows and auroral dynamics during substorm: a case study

    Directory of Open Access Journals (Sweden)

    N. L. Borodkova

    Full Text Available Interball-1 observations of a substorm development in the mid-tail on 16 December 1998 are compared with the auroral dynamics obtained from the Polar UV imager. Using these data, the relationship between plasma flow directions in the tail and the location of the auroral activation is examined. Main attention is given to tailward and earth-ward plasma flows, interpreted as signatures of a Near Earth Neutral Line (NENL. It is unambiguously shown that in the mid-plasma sheet the flows were directed tailward when the auroral bulge developed equatorward of the spacecraft ionospheric footprint. On the contrary, when active auroras moved poleward of the Interball-1 projection, earthward fast flow bursts were observed. This confirms the concept that the NENL (or flow reversal region is the source of auroras forming the poleward edge of the auroral bulge. The observed earthward flow bursts have all typical signatures of Bursty Bulk Flows (BBFs, described by Angelopolous et al. (1992. These BBFs are related to substorm activations starting at the poleward edge of the expanded auroral bulge. We interpret the BBFs as a result of reconnection pulses occurring tail-ward of Interball-1. In addition, some non-typically observed phenomena were detected in the plasma sheet during this substorm: (i tailward/earthward flows were superimposed on a very strong duskward flow, and (ii wavy structures of both magnetic field and plasma density were registered. The latter observation is probably linked to the filamentary structure of the current sheet.

    Key words. Magnetospheric physics (auroral phenomena; plasma sheet; storms and substorms

  9. Power flow and efficiency in supplying systems of arc plasma generators

    International Nuclear Information System (INIS)

    An arc plasma generator requires a supplying system of several hundred kVA and with such operating characteristics as to ignite the discharge at a high voltage of 10 to 20 kV and then to maintain it at a voltage ten times lower. There are many various types of arc plasma generators and they differ considerably from one another depending on their application, construction and kind of discharge used for plasma generation. An arc plasma generator with a gliding arc and the supplying systems are discussed, this mainly from the point of view of power flow and efficiency. (author)

  10. ExB mean flows in finite ion temperature plasmas

    CERN Document Server

    Madsen, J; Naulin, V; Nielsen, A H

    2016-01-01

    The impact of ion pressure dynamics on E x B mean flows is investigated. Three stresses in addition to the Reynolds stress are shown to modify the E x B mean flow. These additional terms in the stress tensor all require ion pressure fluctuations. Quasi-linear analysis indicates that these additional stresses are as important as the standard Reynolds stress and hence must be taken into account in analysis of E x B mean flows.

  11. Plasma depletion layer: Magnetosheath flow structure and forces

    Directory of Open Access Journals (Sweden)

    Y. L. Wang

    2004-03-01

    Full Text Available The plasma depletion layer (PDL is a layer on the sunward side of the magnetopause with lower plasma density and higher magnetic field compared to the corresponding upstream magnetosheath values. In a previous study, we have validated the UCLA global (MHD model in studying the formation of the PDL by comparing model results, using spacecraft solar wind observations as the driver, with in situ PDL observations. In this study, we extend our previous work and examine the detailed MHD forces responsible for the PDL formation. We argue that MHD models, instead of gasdynamic models, should be used to study the PDL, because gasdynamic models cannot produce the PDL on the sunward side of the magnetopause. For northward (IMF, flux tube depletion occurs in almost all the subsolar magnetosheath. However, the streamlines closest to the magnetopause and the stagnation line show the greatest depletion. The relative strength of the various MHD forces changes along these streamlines. Forces along a flux tube at different stages of its depletion in the magnetosheath are analyzed. We find that a strong plasma pressure gradient force along the magnetic field at the bow shock and a pressure gradient force along the flux tube within the magnetosheath usually exist pushing plasma away from the equatorial plane to deplete the flux tube. More complex force structures along the flux tube are found close to the magnetopause. This new, more detailed description of flux tube depletion is compared with the results of Zwan and Wolf (1976 and differences are found. Near the magnetopause, the pressure gradient force along the flux tube either drives plasma away from the equatorial plane or pushes plasma toward the equatorial plane. As a result, a slow mode structure is seen along the flux tube which might be responsible for the observed two-layered slow mode structures.

    Key words. Magnetospheric physics (magnetosheath; solar wind-magnetosphere interactions. Space

  12. Alfven wave coupled with flow-driven fluid instability in interpenetrating plasmas

    CERN Document Server

    Vranjes, J

    2015-01-01

    The Alfven wave is analyzed in case of one quasineutral plasma propagating with some constant speed $v_0$ through another static quasineutral plasma. A dispersion equation is derived describing the Alfven wave coupled with the flow driven mode $\\omega= k v_0$ and solutions are discussed analytically and numerically. The usual solutions for two oppositely propagating Alfv\\'en waves are substantially modified due to the flowing plasma. More profound is modification of the solution propagating in the negative direction with respect to the magnetic field and the plasma flow. For a large enough flow speed (exceeding the Alfven speed in the static plasma), this negative solution may become non-propagating, with frequency equal to zero. In this case it represents a spatial variation of the electromagnetic field. For greater flow speed it becomes a forward mode, and it may merge with the positive one. This merging of the two modes represents the starting point for a flow-driven instability, with two complex-conjugate...

  13. Bottled Water Everywhere: Keeping it Safe

    Science.gov (United States)

    ... regulations. These beverages are instead considered to be soft drinks. back to top It May Be Tap Water ... and Nutrient-Added Water Beverages Bottled Water/Carbonated Soft Drinks Guidance Documents & Regulatory Information How FDA regulates bottled ...

  14. 27 CFR 25.142 - Bottles.

    Science.gov (United States)

    2010-04-01

    ... bottle, the nature of the product such as beer, ale, porter, stout, etc., and the place of production... 5100.31, when required by Part 7 of this chapter. (f) Short-fill bottles. A brewer may dispose...

  15. Lowest modes of a bottle

    International Nuclear Information System (INIS)

    Helmholtz's model predicts correctly the frequency of the lowest mode of a bottle. A simple generalization of Helmholtz's model correctly predicts this mode and also the next few modes: ''flute modes'': of flasks with long uniform necks but arbitrarily shaped bodies. Wine bottles have additional low-frequency ''cavity modes'' that require a further easy generalization. For a bottle with slowly varying cross section an additional generalization can be made that retains the one-dimensional (1-D) character of the previous models and gives results that are in good agreement with experiment for the lowest mode: the ''diametral mode'': of a hollow sphere. For higher modes of a sphere, the 1-D model is inadequate and must be discarded in favor of exact solutions of the 3-D wave equation

  16. Experimental Study of Plasma Actuator Effects on Flow Field Separation Bubble around Blunt Flat Plate

    OpenAIRE

    Saeed Kavousfar; Esmaeil Esmaeilzadeh; hossein mahdavy moghaddam; Sohrab Gholamhosein Pouryoussefi; Masoud Mirzaei

    2016-01-01

    In this paper, the air flow around a blunt flat plate with a rounded leading edge has been experimentally examined with and without the presence of a plasma actuator. Tests have been conducted with Reynolds numbers ranging from 104 to 105. Significant phenomena in this flow field is the flow separation at the leading edge of the body, which called separation bubble. There are two considerably dimensionless parameters in this experiment. One of them is the leading edge radius ratio...

  17. Nonlinear generation of sheared flows and zonal magnetic fields by electron whistlers in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Chakrabarti, Nikhil, E-mail: nikhil.chakrabarti@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064 (India); Shukla, Padma K., E-mail: profshukla@yahoo.de [Institute for Theoretical Physics, International Centre for Advanced Studies in Physical Sciences, Ruhr University Bochum, D-44780 Bochum (Germany)

    2011-10-24

    The nonlinear generation of shear field and flow in whistler waves is considered. It is shown that a coherent parametric process leads to modulational instability of four waves whistler interaction. Growth rates for the flow/field are compared with published simulation results. -- Highlights: → The mechanisms of self-generated flow and field has been done in EMHD plasma. → A parametric process leads to modulational instability. → The growth rate matches with simulation results.

  18. Active Control of Flow around NACA 0015 Airfoil by Using DBD Plasma Actuator

    Directory of Open Access Journals (Sweden)

    Şanlısoy A.

    2013-04-01

    Full Text Available In this study, effect of plasma actuator on a flat plate and manipulation of flow separation on NACA0015 airfoil with plasma actuator at low Reynolds numbers were experimentally investigated. In the first section of the study, plasma actuator which consists of positive and grounded electrode couple and dielectric layer, located on a flat plate was actuated at different frequencies and peak to peak voltages in range of 3-5 kHz and 6-12 kV respectively. Theinduced air flow velocity on the surface of flat plate was measured by pitot tube at different locations behind the actuator. The influence of dielectricthickness and unsteady actuation with duty cycle was also examined. In the second section, the effect of plasma actuator on NACA0015 airfoil was studied atReynolds number 15000 and 30000. Four plasma actuators were placed at x/C = 0.1, 0.3, 0.5 and 0.9, and different electrode combinations were activated by sinusoidal signal. Flow visualizations were done when the attack angles were 0°, 5°, 10°, 15° and 20°. The results indicate that up to the 15° attack angle, the separated flow was reattached by plasma actuator at 12kV peak to peak voltage and 4 kHz frequency. However, 12 kVpp voltage was insufficient to reattach the flow at 20° angle of attack. The separated flow could be reattached by increasing the voltage up to 13 kV. Lift coefficient was also increased by the manipulated flow over the airfoil. Results showed that even high attack angles, the actuators can control the flow separation and prevent the airfoil from stall at low Reynolds numbers.

  19. Supersonic Plasma Flows and their Influence on Aerodynamics of Flight

    International Nuclear Information System (INIS)

    Different types of gas discharges were considered from the point of view of plasma technique applications for aerodynamic problem solutions. They are: the longitudinal one (when electric current j is parallel to airflow's velocity v) and the transverse one (when electric current j is perpendicular to v) stationary discharges, high frequency discharges, microwave and optical discharges. Generation of gas discharges directly before an airplane or on its surface could be the possible means of plasma affect the supersonic airflow. It could lead to the substantial improvement of its aerodynamic characteristics, and particularly to a considerable decrease of the head drag coefficient. (author)

  20. 27 CFR 31.232 - Wine bottling.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Wine bottling. 31.232... OF THE TREASURY LIQUORS ALCOHOL BEVERAGE DEALERS Miscellaneous § 31.232 Wine bottling. Each person desiring to bottle, package, or repackage taxpaid wines must, before carrying on those operations,...

  1. Gas flow dependence for plasma-needle disinfection of S. mutans bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Goree, J [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Liu Bin [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Drake, David [Dows Institute for Dental Research, Dept. of Endodontics, College of Dentistry, University of Iowa, Iowa City, IA 52242 (United States)

    2006-08-21

    The role of gas flow and transport mechanisms are studied for a small low-power impinging jet of weakly-ionized helium at atmospheric pressure. This plasma needle produces a non-thermal glow discharge plasma that kills bacteria. A culture of Streptococcus mutans (S. mutans) was plated onto the surface of agar, and spots on this surface were then treated with plasma. Afterwards, the sample was incubated and then imaged. These images, which serve as a biological diagnostic for characterizing the plasma, show a distinctive spatial pattern for killing that depends on the gas flow rate. As the flow is increased, the killing pattern varies from a solid circle to a ring. Images of the glow reveal that the spatial distribution of energetic electrons corresponds to the observed killing pattern. This suggests that a bactericidal species is generated in the gas phase by energetic electrons less than a millimetre from the sample surface. Mixing of air into the helium plasma is required to generate the observed O and OH radicals in the flowing plasma. Hydrodynamic processes involved in this mixing are buoyancy, diffusion and turbulence.

  2. Gas flow dependence for plasma-needle disinfection of S. mutans bacteria

    International Nuclear Information System (INIS)

    The role of gas flow and transport mechanisms are studied for a small low-power impinging jet of weakly-ionized helium at atmospheric pressure. This plasma needle produces a non-thermal glow discharge plasma that kills bacteria. A culture of Streptococcus mutans (S. mutans) was plated onto the surface of agar, and spots on this surface were then treated with plasma. Afterwards, the sample was incubated and then imaged. These images, which serve as a biological diagnostic for characterizing the plasma, show a distinctive spatial pattern for killing that depends on the gas flow rate. As the flow is increased, the killing pattern varies from a solid circle to a ring. Images of the glow reveal that the spatial distribution of energetic electrons corresponds to the observed killing pattern. This suggests that a bactericidal species is generated in the gas phase by energetic electrons less than a millimetre from the sample surface. Mixing of air into the helium plasma is required to generate the observed O and OH radicals in the flowing plasma. Hydrodynamic processes involved in this mixing are buoyancy, diffusion and turbulence

  3. Numerical simulation of laminar plasma dynamos in a cylindrical von K\\'arm\\'an flow

    CERN Document Server

    Khalzov, I V; Ebrahimi, F; Schnack, D D; Forest, C B; 10.1063/1.3559472

    2011-01-01

    The results of a numerical study of the magnetic dynamo effect in cylindrical von K\\'arm\\'an plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity (i.e., the fluid Reynolds number Re is comparable to the magnetic Reynolds number Rm). This is in contrast to liquid metal experiments, where Pm is small (so, Re>>Rm) and the flows are always turbulent. We explore dynamo action through simulations using the extended magnetohydrodynamic NIMROD code for an isothermal and compressible plasma model.We also study two-fluid effects in simulations by including the Hall term in Ohm's law. We find that the counter-rotating von K\\'arm\\'an flow results in sustained dynamo action and the self-generation of magnetic field when the magnetic Reynolds number exceeds a critical value. For the plasma parameters of the experiment, this field ...

  4. Characteristics of pulsed plasma synthetic jet and its control effect on supersonic flow

    Institute of Scientific and Technical Information of China (English)

    Jin Di; Cui Wei; Li Yinghong; Li Fanyu; Jia Min; Sun Quan; Zhang Bailing

    2015-01-01

    The plasma synthetic jet is a novel flow control approach which is currently being stud-ied. In this paper its characteristic and control effect on supersonic flow is investigated both exper-imentally and numerically. In the experiment, the formation of plasma synthetic jet and its propagation velocity in quiescent air are recorded and calculated with time resolved schlieren method. The jet velocity is up to 100 m/s and no remarkable difference has been found after chang-ing discharge parameters. When applied in Mach 2 supersonic flow, an obvious shockwave can be observed. In the modeling of electrical heating, the arc domain is not defined as an initial condition with fixed temperature or pressure, but a source term with time-varying input power density, which is expected to better describe the influence of heating process. Velocity variation with different heat-ing efficiencies is presented and discussed and a peak velocity of 850 m/s is achieved in still air with heating power density of 5.0 · 1012 W/m3. For more details on the interaction between plasma syn-thetic jet and supersonic flow, the plasma synthetic jet induced shockwave and the disturbances in the boundary layer are numerically researched. All the results have demonstrated the control authority of plasma synthetic jet onto supersonic flow.

  5. Characteristics of pulsed plasma synthetic jet and its control effect on supersonic flow

    Directory of Open Access Journals (Sweden)

    Jin Di

    2015-02-01

    Full Text Available The plasma synthetic jet is a novel flow control approach which is currently being studied. In this paper its characteristic and control effect on supersonic flow is investigated both experimentally and numerically. In the experiment, the formation of plasma synthetic jet and its propagation velocity in quiescent air are recorded and calculated with time resolved schlieren method. The jet velocity is up to 100 m/s and no remarkable difference has been found after changing discharge parameters. When applied in Mach 2 supersonic flow, an obvious shockwave can be observed. In the modeling of electrical heating, the arc domain is not defined as an initial condition with fixed temperature or pressure, but a source term with time-varying input power density, which is expected to better describe the influence of heating process. Velocity variation with different heating efficiencies is presented and discussed and a peak velocity of 850 m/s is achieved in still air with heating power density of 5.0 × 1012 W/m3. For more details on the interaction between plasma synthetic jet and supersonic flow, the plasma synthetic jet induced shockwave and the disturbances in the boundary layer are numerically researched. All the results have demonstrated the control authority of plasma synthetic jet onto supersonic flow.

  6. Cluster observation of plasma flow reversal in the magnetotail during a substorm

    Directory of Open Access Journals (Sweden)

    A. T. Y. Lui

    2006-08-01

    Full Text Available We investigate in detail a reversal of plasma flow from tailward to earthward detected by Cluster at the downstream distance of ~19 RE in the midnight sector of the magnetotail on 22 August 2001. This flow reversal was accompanied by a sign reversal of the Bz component and occurred during the late substorm expansion phase as revealed by simultaneous global view of auroral activity from IMAGE. We examine the associated Hall current system signature, current density, electric field, Lorentz force, and current dissipation/dynamo term, the last two parameters being new features that have not been studied previously for plasma flow reversals. It is found that (1 there was no clear quadrupole Hall current system signature organized by the flow reversal time, (2 the x-component of the Lorentz force did not change sign while the other two did, (3 the timing sequence of flow reversal from the Cluster configuration did not match tailward motion of a single plasma flow source, (4 the electric field was occasionally dawnward, producing a dynamo effect, and (5 the electric field was occasionally larger at the high-latitude plasma sheet than near the neutral sheet. These observations are consistent with the current disruption model for substorms in which these disturbances are due to shifting dominance of multiple current disruption sites and turbulence at the observing location.

  7. From Blogs to Bottle Caps

    Science.gov (United States)

    Edinger, Ted

    2012-01-01

    There is a wonderful community of art educators connecting a once-isolated profession through blogging. Art educators around the world are sharing ideas and communicating with their peers through this amazing resource. In this article, the author describes the bottle cap mural at Tulip Grove Elementary School which was inspired by this exchange of…

  8. FLOW NEAR PLASMA DISCHARGE WITH LOW-FREQUENCY MODULATION

    Czech Academy of Sciences Publication Activity Database

    Uruba, Václav; Procházka, Pavel P.; Matějka, Milan

    Praha : ÚTAM, 2009 - (Náprstek,, J.; Fischer, C.), s. 280-281 ISBN 978-80-86246-35-2. [ Engineering mechanics 2009. Svratka (CZ), 11.05.2009-14.05.2009] R&D Projects: GA ČR GA101/08/1112 Institutional research plan: CEZ:AV0Z20760514 Keywords : plasma discharge * modulation Subject RIV: BK - Fluid Dynamics

  9. Dielectric Barrier Discharge Plasma Actuator for Flow Control

    Science.gov (United States)

    Opaits, Dmitry, F.

    2012-01-01

    This report is Part II of the final report of NASA Cooperative Agreement contract no. NNX07AC02A. It includes a Ph.D. dissertation. The period of performance was January 1, 2007 to December 31, 2010. Part I of the final report is the overview published as NASA/CR-2012- 217654. Asymmetric dielectric barrier discharge (DBD) plasma actuators driven by nanosecond pulses superimposed on dc bias voltage are studied experimentally. This produces non-self-sustained discharge: the plasma is generated by repetitive short pulses, and the pushing of the gas occurs primarily due to the bias voltage. The parameters of ionizing pulses and the driving bias voltage can be varied independently, which adds flexibility to control and optimization of the actuators performance. The approach consisted of three elements coupled together: the Schlieren technique, burst mode of plasma actuator operation, and 2-D numerical fluid modeling. During the experiments, it was found that DBD performance is severely limited by surface charge accumulation on the dielectric. Several ways to mitigate the surface charge were found: using a reversing DC bias potential, three-electrode configuration, slightly conductive dielectrics, and semi conductive coatings. Force balance measurements proved the effectiveness of the suggested configurations and advantages of the new voltage profile (pulses+bias) over the traditional sinusoidal one at relatively low voltages. In view of practical applications certain questions have been also addressed, such as electrodynamic effects which accompany scaling of the actuators to real size models, and environmental effects of ozone production by the plasma actuators.

  10. Bombardment of Thin Lithium Films with Energetic Plasma Flows

    Science.gov (United States)

    Gray, Travis Kelly

    2009-01-01

    The Divertor Erosion and Vapor Shielding Experiment (DEVEX) has been constructed in the Center for Plasma-Material Interactions at the University of Illinois at Urbana-Champaign. It consists of a conical theta-pinch connected to a 60 kV, 36 [mu]F capacitor bank which is switched with a rise time of 3.5 [mu]s. This results in a peak current of 300…

  11. Supersonic flow with shock waves. Monte-Carlo calculations for low density plasma. I

    International Nuclear Information System (INIS)

    This Report gives preliminary information about a Monte Carlo procedure to simulate supersonic flow past a body of a low density plasma in the transition regime. A computer program has been written for a UNIVAC 1108 machine to account for a plasma composed by neutral molecules and positive and negative ions. Different and rather general body geometries can be analyzed. Special attention is played to tho detached shock waves growth In front of the body. (Author) 30 refs

  12. Experimental investigation of MHD impact on argon plasma flows by variation of magnetic flux density

    OpenAIRE

    Knapp, A.; Fulge, Hannes; Herdrich, Georg; Ono, N.; Wernitz, Ricarda; AUWETER-KURTZ, Monika; Röser, Hans-Peter; Fasoulas, Stefanos

    2012-01-01

    The interaction between a probe body and argon plasma flow is investigated to examine to what extent the probe head temperature and the bow shock distance can be influenced by applying a strong magnetic field. The experiments are performed using a strong permanent magnet installed inside a probe body with a spherical, coated probe head. Former investigations showed strong influence on the bow shock geometry but also on the inflow plasma jet. Several boundary conditions have been varied to eva...

  13. Measurement of Sheared Flows in the Edge Plasma of the CASTOR Tokamak

    Czech Academy of Sciences Publication Activity Database

    Brotánková, Jana; Stöckel, Jan; Horáček, Jan; Seidl, Jakub; Ďuran, Ivan; Hron, Martin; Van Oost, G.

    2009-01-01

    Roč. 35, č. 11 (2009), s. 980-986. ISSN 1063-780X. [IAEA Technical Meeting on Research Using Small Fusion Devices/18th./. Alushta (Krym), 25.09.2008-27.09.2008] Institutional research plan: CEZ:AV0Z20430508 Keywords : Tokamak * probe diagnostics * shear ed flows * edge plasma * turbulence Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.584, year: 2009 http://www.springerlink.com/content/u571504gmq118314/

  14. Cross-field flow and electric potential in a plasma slab

    Directory of Open Access Journals (Sweden)

    J. De Keyser

    2013-08-01

    Full Text Available We consider cross-field plasma flow inside a field-aligned plasma slab embedded in a uniform background in a 1-dimensional geometry. This situation may arise, for instance, when long-lasting reconnection pulses inject plasma into the inner magnetosphere. The present paper presents a detailed analysis of the structure of the interfaces that separate the slab from the background plasma on either side; a fully kinetic model is used to do so. Since the velocity shear across both interfaces has opposite signs, and given the typical gyroradius differences between injected and background ions and electrons, the structure of both interfaces can be very different. The behaviour of the slab and its interfaces depends critically on the flow of the plasma transverse to the magnetic field; in particular, it is shown that there are bounds to the flow speed that can be supported by the magnetised plasma. Further complicating the picture is the effect of the potential difference between the slab and its environment.

  15. Dusty plasma synthesis of nanostructured Zn/ZnO-carbon nanotube composites by aerosol flow condensation

    Energy Technology Data Exchange (ETDEWEB)

    Lennox, Martin, E-mail: martin.lennox@mcgill.ca; Coulombe, Sylvain, E-mail: sylvain.coulombe@mcgill.ca [McGill University, Plasma Processing Laboratory, Department of Chemical Engineering (Canada)

    2012-11-15

    A new, dusty plasma process for depositing nanoparticles generated by aerosol flow condensation and treated using a 13.56 MHz capacitively-coupled non-thermal glow discharge is described. The use of organometallic compounds as nanoparticle precursors is avoided, thereby allowing for a processing plasma free of contaminating degradation products. Nanostructured composites of zinc and zinc oxide were deposited on carbon nanotubes with complete coverage, and the influences of the argon quench and sheath gas flow rates, and the presence of 0.5 vol.% ethane in the processing plasma on the synthesized composites was investigated by electron microscopy and X-ray diffraction (XRD). In the absence of plasma, {approx}1 {mu}m Zn microparticles composed of agglomerated nanoparticles were formed on the carbon nanotube surface. Plasma processing produced coatings of nanoparticles with lognormal size distributions and median diameters of {approx}5 nm. At maximum argon flow rates, the distribution was monodisperse, whereas lower flow rates produced bimodal size distributions with the second mode having median values of {approx}70 nm.

  16. Calculation of Ion Energy Distribution Functions at the Inner Surface of a Pet Bottle During Sterilization Processes

    Science.gov (United States)

    Szeremley, Daniel; Steves, Simon; Brinkmann, Ralf Peter; Awakowicz, Peter; Kushner, Mark J.; Mussenbrock, Thomas

    2012-10-01

    Due to a growing demand for bottles made of polyethylene terephthalate (PET) fast and efficient sterilization processes as well as barrier coating to decrease gas permeation are required. Plasma sterilization is an alternative way of sterilizing PET without using toxic ingredients (e.g. hydrogen peroxide or peracetic acid). To allow investigations in the field of plasma sterilization of PET bottles, a microwave plasma reactor has been developed. A coaxial waveguide combined with a gas-inlet, a modified plasmaline, is used for both coupling the microwave power and injecting the gas mixture into the bottle. One key parameter in the context of plasma treatment of bottles is the ion energy distribution function (IEDF) at the inner surface of the bottle. Additional it is possible to apply a DC bias potential to a metal cage which is placed around the bottle. Numerical results for IEDFs performed by means of the Hybrid Plasma Equipment Model (HPEM) are presented. Plasmas with relevant gas mixtures (Ar and ArO2) at different pressures and input powers are examined. The numerical results are compared with experimentally obtained data and show very good agreement.

  17. Experimental Study of the Flow Field around a Circular Cylinder Using Plasma Actuators

    Directory of Open Access Journals (Sweden)

    Siavash Tabatabaeian

    2015-01-01

    Full Text Available In this paper different configurations of plasma actuator for controlling the flow around a circular cylinder made of Quartz were experimentally investigated. Three thin plasma actuator electrodes were flush-mounted on the surface of the cylinder and were connected to a DC high voltage power supply for generation of electrical discharge. Different configurations of plasma actuator were used for this study and pressure distribution experiments showed that the existence of the plasma decreases the pressure coefficient of the cylinder and the variation of the pressure coefficient can change the behavior of the lift and drag coefficient of the cylinder for all configurations. According to the pressure distribution data, two configurations of the plasma actuators made the best influence on the aerodynamic performance and also on the drag reduction.

  18. Assessment of glomerular filtration rate and effective renal plasma flow in cystic fibrosis

    International Nuclear Information System (INIS)

    A study was conducted to examine renal function in 10 healthy control subjects and eight patients with cystic fibrosis in stable condition. Sequential bolus injections of /sup 99m/Tc-DTPA and 125I-OIH were administered to assess glomerular filtration rate and effective renal plasma flow, respectively. Blood was subsequently collected for 3 hours, and urine for 24 hours. Renal clearances of both radioisotope markers were virtually identical in patients and controls. Inasmuch as neither glomerular filtration rate nor effective renal plasma flow was enhanced in patients with cystic fibrosis, increased clearance of drugs in these patients is unlikely to be the result of enhanced glomerular filtration or tubular secretion

  19. Zonal flow generation in the improved confinement mode plasma and its role in confinement bifurcations

    International Nuclear Information System (INIS)

    Unstable fluctuations develop in the initially quiescent plasma in the improved confinement mode of the H-1 heliac when the radial electric field (Er) shear exceeds some critical value. These unstable Er shear-driven modes are shown to generate zonal-flow-like poloidally symmetric potential structures, similar to those generated in the low confinement mode (Shats M G and Solomon W M 2002 Phys. Rev. Lett. 88 045001). The structures modulate their parent waves, the background Er shear and the fluctuation-driven radial transport. The onset of zonal flows is observed as a precursor to the plasma confinement bifurcation to an even higher confinement regime. (author)

  20. Qualitative Assessment Of Bottled Water In The Middle East

    OpenAIRE

    Ahmad, S; Saleem, Abdul

    1996-01-01

    Many brands of bottled water are being produced in the Middle East including the Gulf Cooperation Council (GCC) countries. Over fourteen brands of bottled water could be found in the market of Doha. Use of bottled water has kept on increasing in this region. Reasons for the increase in use of bottled water for drinking have been discussed. The raw water source for the bottled water is groundwater. Most of the manufacturers of the bottled water claim bottled water as "Natural Mineral Water...

  1. Study on Free Surface and Channel Flow Induced by Low-Temperature Plasma via Lattice Boltzmann Method

    Science.gov (United States)

    Wan, Gang; Jin, Yong; Li, Haiyuan; Li, Baoming

    2016-03-01

    Active boundary layer flow control and boundary layer manipulation in the channel flow that was based on low temperature plasma were studied by means of a lattice Boltzmann method. Two plasma actuators were placed in a row to obtain the influence rule of their separation distance on the velocity profile at three locations and maximum velocity in the flow field. Two plasma actuators were placed symmetrically inside a channel to examine the effect of channel height and voltage on the velocity profile and flow rate. It was found that the channel height controls the distribution of flow velocity, which affected the flow rate and its direction. Increasing plasma voltage had a negative effect on the flow rate due to the generation of a larger and stronger flow vortex.

  2. Experimental investigation of plasma flows in open trap with toroidal diverter under ECR discharge

    Energy Technology Data Exchange (ETDEWEB)

    Berezkin, A. V., E-mail: Berezkin-AV@nrcki.ru; Bragin, E. Yu., E-mail: Bragin-EY@nrcki.ru; Zhil’tsov, V. A., E-mail: Zhiltsov-VA@nrcki.ru; Kulygin, V. M., E-mail: Kulygin-VM@nrcki.ru; Yanchenkov, S. V., E-mail: Yanchenkov-SV@nrcki.ru [National Research Center Kurchatov Institute (Russian Federation)

    2015-12-15

    The results of experimental investigations of plasma flows from an open trap with a toroidal diverter are presented. Cold plasma is generated when introducing microwave power under conditions of electron cyclotron resonance (ECR). The radiation is introduced by a waveguide through a vacuum-tight ceramic window across the axis of the device. By means of the Langmuir probes, the spatial distributions of plasma parameters are measured. The highest density is limited to a critical value n{sub c} (∼10{sup 12} cm{sup –3}) for the generator frequency under use. It is found that the temperature and density of the plasma in the trap and in escaping flows are almost independent of the radius when the ECR zone is located near the open-trap confinement region and the density is close to n{sub c}. At the density n < n{sub c}, ring plasma structures, which collapse under the action of a low-frequency instability, are observed near the separatrix. The possible mechanisms of the occurrence of plasma structures and the nature of the plasma streams are discussed.

  3. Effect of initial radial mass distribution on the dynamics of the coaxial plasma flow switch

    International Nuclear Information System (INIS)

    The use of coaxial plasma flow switches to charge a vacuum inductive store and drive high speed, sub-microsecond plasma implosions has been under study at the Air Force Weapons Laboratory. In the coaxial plasma flow switch, an annular disk of plasma is accelerated by J X B forces down the barrel of a cylindrical coax gun; this annular plasma disk represents the moving element in a vacuum magnetic field inductive store pulse sharpening network. The switch plasma crosses the 2 cm high implosion gap at a velocity of about 6.5 cm/usec, resulting in a current transfer time to the implosion load of approximately 300 nsecs. A series of two-dimensional magnetohydrodynamic (MHD) computer simulations have been done to determine the effects of the initial radial mass distribution of the annular plasma disk on the dynamical behavior of the coaxial run-down phase. These calculations were carried out using the two-dimensional MHD code called HAM

  4. Estimation of effective renal plasma flow in children by use of a single plasma sample after injection of orthoiodohippurate

    International Nuclear Information System (INIS)

    Estimates of effective renal plasma flow (ERPF) in adults have been greatly simplified by the use of recently developed regression equations based on a single plasma concentration of radioiodinated orthoiodohippurate (OIH) obtained 44 min after a single intravenous injection of the material. The paper reports similar equations for the prediction of ERPF in children. Studies were made in 30 children of both sexes, aged 4 to 16 years, with a wide variety of renal diseases. A single intravenous injection of labelled OIH was made and plasma was sampled at 10, 15, 20, 25, 30, 40, 50 and 60 min after injection. Plasma concentration curves were analysed by the conventional two-compartment analysis technique (Sapirstein, Matthews) and ERPF was computed from them. In addition to ERPF calculations, sizes of the two volumes of distribution (V1 and V2), intercompartmental flow rates and fractional rate constants were also calculated. Surface area (SA) was calculated from the DuBois height-weight regression formula. Reciprocals of the OIH plasma concentration in terms of per cent injected dose per litre were calculated at each sampling time; this reciprocal is designated x. These values at each sampling time were plotted against ERPF and regression equations and residual error (Sy.x) were calculated. The optimal sampling time was found to occur at 53 min and the corresponding linear regression equation was 19.33 + 3.87x with a Sy.x value of 36 ml. This compares with an optimal sampling time in adults of 44 min. The mean initial volume of distribution (V1) was found to be 5.3 litres and the mean V2 was found to be 6.8 litres. In contrast to findings in the previous study in adults these volumes were found to correlate well with SA. A mean intercompartmental flow rate of 276 ml/min was found. No correlation between this value and clinical diagnosis was found. The relationship of the concentration reciprocal and plasma flow was a linear one instead of the polynomial one found in

  5. MHD equilibrium of toroidal fusion plasma with stationary flows; Rownowaga MHD toroidalnej plazmy termojadrowej z przeplywami

    Energy Technology Data Exchange (ETDEWEB)

    Galkowski, A. [Institute of Atomic Energy, Otwock-Swierk (Poland)

    1994-12-31

    Non-linear ideal MHD equilibria in axisymmetric system with flows are examined, both in 1st and 2nd ellipticity regions. Evidence of the bifurcation of solutions is provided and numerical solutions of several problems in a tokamak geometry are given, exhibiting bifurcation phenomena. Relaxation of plasma in the presence of zero-order flows is studied in a realistic toroidal geometry. The field aligned flow allows equilibria with finite pressure gradient but with homogeneous temperature distribution. Numerical calculations have been performed for the 1st and 2nd ellipticity regimes of the extended Grad-Shafranov-Schlueter equation. Numerical technique, alternative to the well-known Grad`s ADM methods has been proposed to deal with slow adiabatic evolution of toroidal plasma with flows. The equilibrium problem with prescribed adiabatic constraints may be solved by simultaneous calculations of flux surface geometry and original profile functions. (author). 178 refs, 37 figs, 5 tabs.

  6. Two-Phase Flow Regimes and Discharge Characteristics of a Plasma Electrohydrodynamic Atomization

    International Nuclear Information System (INIS)

    Experimental investigation was conducted to study the flow regimes and discharge characteristics of plasma electrohydrodynamic atomization (EHDA) for decane (C10H22) under pulsed applied negative voltage. The experimental parameters were set as the flow rate of decane from 0 mL/min to 10 mL/min and the DC charging voltage from DC 0 V to 12 V with a pulse repetition rates of 200 Hz. The flow regime of decane was observed and the volume-to-electrical charge ratio was measured. Unlike a conventional EHDA system, the results show that a corona discharge was initiated at the edge of the hollow electrode at a specific corona on-set voltage of -17 kV or -20 kV in the case with or without decane flow, respectively. This phenomenon was defined as plasma EHDA.

  7. Novel Gas Barrier SiOC Coating to PET Bottles through a Hot Wire CVD Method

    OpenAIRE

    Nakaya, Masaki; Kodama, Kenji; Yasuhara, Shigeo; Hotta, Atsushi

    2016-01-01

    In an attempt to enhance the gas barrier enhancement of plastic containers such as poly(ethylene terephthalate) bottles, a novel method was found using a hot wire CVD technique, where tantalum wire is heated and exposed to a gas flow of vinyl silane. The resultant SiOC thin film was confirmed to characteristically contain Si-Si bonds in its surface and demonstrate a remarkably and highly practical decrease of the permeation of various gas through poly(ethylene terephthalate) bottles.

  8. Cluster observation of plasma flow reversal in the magnetotail during a substorm

    OpenAIRE

    A. T. Y. Lui; Zheng, Y; Zhang, Y.; Livi, S; H. Rème; M. W. Dunlop; G. Gustafsson; Mende, S. B.; Mouikis, C.; Kistler, L. M.

    2006-01-01

    We investigate in detail a reversal of plasma flow from tailward to earthward detected by Cluster at the downstream distance of ~19 RE in the midnight sector of the magnetotail on 22 August 2001. This flow reversal was accompanied by a sign reversal of the Bz component and occurred during the late substorm expansion phase as revealed by simultaneous global view of auroral activity from IMAGE. We exami...

  9. Suppression of Instability in Strongly Coupled Dusty Plasmas with Ion Flow

    Institute of Scientific and Technical Information of China (English)

    贺凯芬; 谢柏松; 刘克富

    2001-01-01

    The instability of low-frequency longitudinal modes in strongly coupled dusty plasmas with an ion flow is investigated. The dust charging relaxation is taken into account. It is found that when the ion flow is strong enough,the suppression, even disappearance. of instability can occur. Similar to that of the real frequency of waves, the imaginary part of waves also exhibits a transition, which arises from the sensitive dependences on the system parameters and their competition.

  10. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    OpenAIRE

    Brust, Matthias,; Aouane, Othmane; Thiébaud, Marine; Flormann, Daniel; Verdier, Claude; Kaestner, Lars; Laschke, Matthias; Selmi, Hassib; Benyoussef, Abdellilah; Podgorski, Thomas; Coupier, Gwennou; Misbah, Chaouqi; Wagner, Christian

    2014-01-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule netw...

  11. Enhanced current flow through a plasma cloud by induction of plasma turbulence

    International Nuclear Information System (INIS)

    Electrodynamic tethers have been proposed as a means of generating power in low earth orbit. One of the limitations on the power generated is the relatively low electron current that can be collected. It is proposed that the electron current can be significantly enhanced by means of current-induced plasma turbulence in a plasma cloud around the collecting anode. This is examined for the specific case of ion acoustic turbulence. An important conclusion is that the use of plasma clouds in the ionosphere will entail a high-impedance (no instability) and a low-impedance (ion acoustic instability) mode of operation. The low-impedance mode of operation will have two submodes, one steady state and one pulsed

  12. MHD stability in flowing plasmas. Connection between fusion plasma and astrophysics research

    International Nuclear Information System (INIS)

    Axisymmetric magneto-rotational instability (MRI) is studied in comparison with interchange instability (IntI) in a rotating cylindrical plasma. MRI is driven by the shear of plasma rotation, and the IntI by the density gradient with effective gravity due to the plasma rotation. The eigenmode equation for the MRI has the same form as that for the IntI. The local stability criterion is also summarized in a similar statement as 'the spatial gradient of centrifugal force greater than the square of Aflven frequency causes instability.' However, the MRI is essentially different from the IntI because of the non-Hermitian property. The Keplerian rotation generates irregular singularity at the center of the disk, which yields a continuum of eigenvalues with non-orthogonal and square-integrable eigenfunctions. (author)

  13. Ray-tracing model of IBW generated sheared flow for plasma transport control

    International Nuclear Information System (INIS)

    A sheared flow generation model based on ion Bernstein wave (IBW) ray-tracing code is developed to improve the sheared flow prediction capability over the previous more analytical calculations. The model provides the momentum drive profile for each ion species for each ray. The calculated driven flow momentum is summed over all ions and all rays in each flux surface. A strong sheared flow is generated near the wave power absorption region since d/dr≅-2 Im kr. The combination of high wave electric fields, large ion response functions, high wave number (which is enhanced near the absorption region), and strong local wave absorption all contribute to make the poloidal sheared flow significant. The model calculation appears to agree well with the induced transport barrier observed during the CH-mode in PBX-M. The model predicts high efficiency for poloidal sheared flow generation in reactor-grade plasmas (e.g. for ITER parameters, PIBW≅10 MWα.) A simple device/plasma scaling based on the IBW wave behavior near the ion cyclotron absorption layer is also obtained. This technique provides a promising tool for active plasma pressure and bootstrap current profile control, which is essential for advance tokamaks such as TPX and DEMO. The peaking of density and pressure profiles could also benefit TFTR and ITER by enhancing fusion reactivity. copyright 1996 American Institute of Physics

  14. Driving mechanism of SOL plasma flow and effects on the divertor performance in JT-60U

    International Nuclear Information System (INIS)

    The measurements of the SOL flow and plasma profiles both at the high-field-side (HFS) and low field- side (LFS), for the first time, identified the SOL flow pattern and its driving mechanism. 'Flow reversal' was found near the HFS and LFS separatrix of the main plasma for the ion ∇β drift direction towards the divertor. Radial profiles of the SOL flow were similar to those calculated numerically using the UEDGE code with the plasma drifts included although Mach numbers in measurements were greater than those obtained numerically. Particle fluxes towards the HFS and LFS divertors produced by the parallel SOL flow and ErxB drift flow were evaluated. The particle flux for the case of intense gas puff and divertor pump (puff and pump) was investigated, and it was found that both the Mach number and collisionality were enhanced, in particular, at HFS. Drift flux in the private flux region was also evaluated, and important physics issues for the divertor design and operation, such as in-out asymmetries of the heat and particle fluxes, and control of impurity ions were investigated. (author)

  15. Driving mechanism of SOL plasma flow an effects on the divertor performance in JT-60U

    International Nuclear Information System (INIS)

    The measurements of the scrape-off layer(SOL) flow and plasma profiles both at the high-field-side (HFS) and low-field-side (LFS), for the first time, identified the SOL flow pattern and its driving mechanism. 'Flow reversal' was found near the HFS and LFS separatrix of the main plasma for the ion ∇B drift direction towards the divertor, Radial profiles of the SOL flow were similar to those calculated numerically using the UEDGE code with the plasma drifts included although Mach numbers in measurements were greater than those obtained numerically. Particle fluxes towards the HFS and LFS divertors produced by the parallel SOL flow and ErxB drift flow were evaluated. The particle flux for the case of intense gas puff and divertor pump (puff and pump) was investigated, and it was found that both the Mach number and collisionality were enhanced, in particular, at HFS. Drift flux in the private flux region was also evaluated, and important physics issues for the divertor design and operation, such as in-out asymmetries of the heat and particle fluxes, and control of impurity ions were investigated. (author)

  16. Experimental and computational study of the flow induced by a plasma actuator

    International Nuclear Information System (INIS)

    Highlights: • A new plasma-actuator (PA) model is proposed to simulate flow manipulation. • The new model is calibrated according to a complementary PIV experiment. • A comparative analysis of different volume-force estimation strategies is provided. • All PA models were applied in conjunction with a near-wall RSM model. • Afterwards the new model was applied to a separated flow in a 3D diffuser. -- Abstract: A complementary experimental and computational study of the flow field evoked by a plasma actuator mounted on a flat plate was in focus of the present work. The main objective of the experimental investigation was the determination of the vector force imparted by the plasma actuator to the fluid flow. The force distribution was presently extracted from the Navier–Stokes equations directly by feeding them with the velocity field measured by a PIV technique. Assuming a steady-in-mean, two-dimensional flow with zero-pressure gradient, the imbalance between the convective term and the momentum equation’s right-hand-side terms reveals the desired resulting force. This force-distribution database was used afterwards as the source term in the momentum equation. Furthermore, an empirical model formulation for the volume-force determination parameterized by the underlying PIV-based model is derived. The model is tested within the RANS framework in order to predict a wall jet-like flow induced by a plasma actuator. The Reynolds equations are closed by a near-wall second-moment closure model based on the homogeneous dissipation rate of the kinetic energy of turbulence. The computationally obtained velocity field is analysed along with the experimental data focussing on the wall jet flow region in proximity of the plasma actuator. For comparison purposes, different existing phenomenological models were applied to evaluate the new model’s accuracy. The comparative analysis of all applied models demonstrates the strength of the new empirical model

  17. Numerical Study of Control of Flow Separation Over a Ramp with Nanosecond Plasma Actuator

    Science.gov (United States)

    Zheng, J. G.; Khoo, B. C.; Cui, Y. D.; Zhao, Z. J.; Li, J.

    2016-06-01

    The nanosecond plasma discharge actuator driven by high voltage pulse with typical rise and decay time of several to tens of nanoseconds is emerging as a promising active flow control means in recent years and is being studied intensively. The characterization study reveals that the discharge induced shock wave propagates through ambient air and introduces highly transient perturbation to the flow. On the other hand, the residual heat remaining in the discharge volume may trigger the instability of external flow. In this study, this type of actuator is used to suppress flow separation over a ramp model. Numerical simulation is carried out to investigate the interaction of the discharge induced disturbance with the external flow. It is found that the flow separation region over the ramp can be reduced significantly. Our work may provide some insights into the understanding of the control mechanism of nanosecond pulse actuator.

  18. Thomson scattering measurements of ion interpenetration in cylindrically converging, supersonic magnetized plasma flows

    Science.gov (United States)

    Swadling, George

    2015-11-01

    Ion interpenetration driven by high velocity plasma collisions is an important phenomenon in high energy density environments such as the interiors of ICF vacuum hohlraums and fast z-pinches. The presence of magnetic fields frozen into these colliding flows further complicates the interaction dynamics. This talk focuses on an experimental investigation of ion interpenetration in collisions between cylindrically convergent, supersonic, magnetized flows (M ~10, Vflow ~ 100km/s, ni ~ 1017cm-3) . The flows used in this study were plasma ablation streams produced by tungsten wire array z-pinches, driven by the 1.4MA, 240ns Magpie facility at Imperial College, and diagnosed using a combination of optical Thomson scattering, Faraday rotation and interferometry. Optical Thomson scattering (TS) provides time-resolved measurements of local flow velocity and plasma temperature across multiple (7 to 14) spatial positions. TS spectra are recorded simultaneously from multiple directions with respect to the probing beam, resulting in separate measurements of the rates of transverse diffusion and slowing-down of the ion velocity distribution. The measurements demonstrate flow interpenetration through the array axis at early time, and also show an axial deflection of the ions towards the anode. This deflection is induced by a toroidal magnetic field (~ 10T), frozen into the plasma that accumulates near the axis. Measurements obtained later in time show a change in the dynamics of the stream interactions, transitioning towards a collisional, shock-like interaction of the streams, and rapid radial collapse of the magnetized plasma column. The quantitative nature of the spatial profiles of the density, flow velocities and ion temperatures measured in these experiments will allow detailed verification of MHD and PIC codes used by the HEDP community. Work Supported by EPSRC (Grant No. EP/G001324/1), DOE (Cooperative Agreement Nos. DE-F03-02NA00057 & DE-SC-0001063) & Sandia National

  19. Topological analysis of plasma flow control on corner separation in a highly loaded compressor cascade

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hu Zhao; Yun Wu; Ying-Hong Li; Xue-De Wang; Qin Zhao

    2012-01-01

    In this paper,flow behavior and topology structure in a highly loaded compressor cascade with and without plasma aerodynamic actuation (PAA) are investigated.Streamline pattern,total pressure loss coefficient,outlet flow angle and topological analysis are considered to study the effect and mechanism of the plasma flow control on corner separation.Results presented include the boundary layer flow behavior,effects of three types of PAA on separated flows and performance parameters,topology structures and sequences of singular points with and without PAA.Two separation lines,reversed flow and backflow exist on the suction surface.The cross flow on the endwall is an important element for the corner separation.PAA can reduce the undertuming and overturning as well as the total pressure loss,leading to an overall increase of flow turning and enhancement of aerodynamic performance.PAA can change the topology structure,sequences of singular points and their corresponding separation lines.Types Ⅱ and Ⅲ PAA are much more efficient in controlling corner separation and enhancing aerodynamic performances than type Ⅰ.

  20. Plasma flow during the brightening of proton aurora in the cusp

    DEFF Research Database (Denmark)

    Taguchi, S.; Hosokawa, K.; Suzuki, S.; Tawara, A.; Frey, H. U.; Matzka, Jürgen; Yukimatu, A. S.; Sato, N.

    2010-01-01

    On the basis of simultaneous observations from the Super Dual Auroral Radar Network (SuperDARN), the far ultraviolet instrument on the IMAGE spacecraft, and a magnetometer installed on the east coast of Greenland, we present the characteristics of plasma flow during a westward moving proton auror...

  1. Application of inertia-induced excitation theory for nonlinear acoustic modes in colloidal plasma equilibrium flow

    Indian Academy of Sciences (India)

    P K Karmakar

    2007-04-01

    Application of inertia-induced acoustic excitation theory offers a new resonant excitation source channel of acoustic turbulence in the transonic domain of plasma flow. In bi-ion plasmas like colloidal plasma, two well-defined transonic points exist corresponding to the parent ion and the dust grain-associated acoustic modes. As usual, the modified ion acoustic mode (also known as dust ion-acoustic (DIA) wave) dynamics associated with parent ion inertia is excitable for both nanoscale- and micronscale-sized dust grains. It is found that the so-called (ion) acoustic mode (also known as dust-acoustic (DA) wave) associated with nanoscale dust grain inertia is indeed resonantly excitable through the active role of weak but finite parent ion inertia. It is interestingly conjectured that the same excitation physics, as in the case of normal plasma sound mode, operates through the active inertial role of plasma thermal species. Details of the nonlinear acoustic mode analyses of current interest in transonic domains of such impure plasmas in hydrodynamic flow are presented.

  2. Modification of the quasiparticle damping rate in presence of flow in hot QCD plasma

    International Nuclear Information System (INIS)

    The study aims to calculate the quark damping rate in hot QCD plasma in presence of flow, whereas in the above cited calculation an equilibrium situation for the bath particles is assumed. The equilibrium condition of the bath particles is true only when there exists no velocity or temperature gradient in the plasma and there is no external force also. In the present context, the study has taken into consideration the existence of the non-zero velocity gradient i.e. flow in the plasma. Under such scenario, one can no longer assume that the bath particles follow the ordinary equilibrium Bose-Einstein or Fermi-Dirac distributions for the interacting bosons or fermions respectively. The situation is quite similar to what one encounters for the calculation of the transport quantities like coefficient of viscosity or conductivity etc

  3. MOSS spectroscopic camera for imaging time resolved plasma species temperature and flow speed

    International Nuclear Information System (INIS)

    A MOSS (Modulated Optical Solid-State) spectroscopic camera has been devised to monitor the spatial and temporal variations of temperatures and flow speeds of plasma ion species, the Doppler broadening measurement being made of spectroscopic lines specified. As opposed to a single channel MOSS spectrometer, the camera images light from plasma onto an array of light detectors, being mentioned 2D imaging of plasma ion temperatures and flow speeds. In addition, compared to a conventional grating spectrometer, the MOSS camera shows an excellent light collecting performance which leads to the improvement of signal to noise ratio and of time resolution. The present paper first describes basic items of MOSS spectroscopy, then follows MOSS camera with an emphasis on the optical system of 2D imaging. (author)

  4. Structure of a Magnetic Flux Annihilation Layer Formed by the Collision of Supersonic, Magnetized Plasma Flows

    Science.gov (United States)

    Suttle, L. G.; Hare, J. D.; Lebedev, S. V.; Swadling, G. F.; Burdiak, G. C.; Ciardi, A.; Chittenden, J. P.; Loureiro, N. F.; Niasse, N.; Suzuki-Vidal, F.; Wu, J.; Yang, Q.; Clayson, T.; Frank, A.; Robinson, T. S.; Smith, R. A.; Stuart, N.

    2016-06-01

    We present experiments characterizing the detailed structure of a current layer, generated by the collision of two counterstreaming, supersonic and magnetized aluminum plasma flows. The antiparallel magnetic fields advected by the flows are found to be mutually annihilated inside the layer, giving rise to a bifurcated current structure—two narrow current sheets running along the outside surfaces of the layer. Measurements with Thomson scattering show a fast outflow of plasma along the layer and a high ion temperature (Ti˜Z ¯ Te , with average ionization Z ¯=7 ). Analysis of the spatially resolved plasma parameters indicates that the advection and subsequent annihilation of the inflowing magnetic flux determines the structure of the layer, while the ion heating could be due to the development of kinetic, current-driven instabilities.

  5. Interaction of ambipolar plasma flow with magnetic islands in a quasi-axisymmetric stellarator

    International Nuclear Information System (INIS)

    A reference equilibrium for the US National Compact Stellarator Experiment is predicted to be sufficiently close to quasi-symmetry to allow the plasma to flow in the toroidal direction with little viscous damping, yet to have sufficiently large deviations from quasi-symmetry that nonambipolarity significantly affects the physics of the shielding of resonant magnetic perturbations by plasma flow. The unperturbed velocity profile is modified by the presence of an ambipolar potential, which broadens the profile and improves the shielding near the plasma edge. In the presence of a resonant magnetic field perturbation, nonambipolar transport produces a radial current, and the resulting jxB force resists departures from the ambipolar velocity and enhances the shielding. (author)

  6. Electrostatic potential in a collisionless plasma flow along open magnetic field lines

    International Nuclear Information System (INIS)

    Formation of the steady-state potential in a collisionless plasma flow along nonuniform magnetic field lines terminated at a wall is studied theoretically under the condition that a particle source in a plasma can be neglected. It is found that the plasma flow is required to satisfy the generalized Bohm criterion over the whole region for the formation of the steady-state continuous potential in the divergent magnetic field. A monotonically falling potential can build up from the inside of the magnetic throat to the wall only if the Bohm criterion is marginally satisfied at the throat. Numerical solutions to Poisson's equation show that a potential profile outside the throat is strongly dependent upon the particle density of electrons trapped between the throat and the wall. Controllability of the potential by increasing the trapped-electron density is discussed briefly. (author)

  7. Experimental evidence of fluctuations and flows near marginal stability in the plasma boundary region of fusion plasmas

    International Nuclear Information System (INIS)

    Electrostatic turbulence has been investigated in the plasma boundary region in the JET tokamak and in the TJ-II stellarator. In both devices the naturally occurring velocity shear layer organizes itself to reach a condition in which the radial gradient in the poloidal phase velocity of fluctuations is comparable to the inverse of the correlation time of fluctuations (1/τ). This result suggests that ExB sheared flows organized themselves to be close to marginal stability (i.e. ωExB ∼ 1/τ). The investigation of the dynamical interplay between fluctuation in gradients, turbulent transport and radial electric fields has shown that these parameters are strongly coupled both in tokamak and stellarator plasmas. The bursty behaviour of turbulent transport is linked with a departure from the most probable radial gradient. The dynamical relation between fluctuations in gradients and transport is strongly affected by the presence of sheared poloidal flows, heating power and the proximity to instability thresholds: the size of large transport events decreases in the proximity of sheared flows and increases with heating power and in the proximity of instability thresholds.These results are consistent with the concept of turbulent transport self-regulated via fluctuations near marginal stability. (author)

  8. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    International Nuclear Information System (INIS)

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial magnetic field. In this way, the neutrals are prevented to reach the target region. The neutral flux to the target must be lower than the plasma flux to enable ITER relevant plasma-surface interaction (PSI) studies. It is therefore essential to control the neutral gas dynamics. The DSMC method was used to model the expansion of a hot gas in a low pressure vessel where a small discrepancy in shock position was found between the simulations and a well-established empirical formula. Two stage differential pumping was modeled and applied in the linear plasma devices Pilot-PSI and PLEXIS. In Pilot-PSI a factor of 4.5 pressure reduction for H2 has been demonstrated. Both simulations and experiments showed that the optimum skimmer position depends on the position of the shock and therefore shifts for different gas parameters. The shape of the skimmer has to be designed such that it has a minimum impact on the shock structure. A too large angle between the skimmer and the forward direction of the gas flow leads to an influence on the expansion structure. A pressure increase in front of the skimmer is formed and the flow of the plasma beam becomes obstructed. It has been shown that a skimmer with an angle around 53 deg. gives the best performance. The use of skimmers is implemented in the design of the large linear plasma generator Magnum-PSI. Here, a three stage differentially pumped vacuum system is used to reach low enough neutral pressures near the target, opening a door to PSI research in the ITER relevant regime

  9. Sheared-flow induced confinement transition in a linear magnetized plasma

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, S.; Heidbrink, W. W.; Boehmer, H.; McWilliams, R. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Carter, T. A.; Vincena, S.; Friedman, B.; Schaffner, D. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)

    2012-01-15

    A magnetized plasma cylinder (12 cm in diameter) is induced by an annular shape obstacle at the Large Plasma Device [W. Gekelman, H. Pfister, Z. Lucky, J. Bamber, D. Leneman, and J. Maggs, Rev. Sci. Instrum. 62, 2875 (1991)]. Sheared azimuthal flow is driven at the edge of the plasma cylinder through edge biasing. Strong fluctuations of density and potential ({delta}n/n{approx}e{delta}{phi}/kT{sub e}{approx}0.5) are observed at the plasma edge, accompanied by a large density gradient (L{sub n}={nabla}lnn{sup -1}{approx}2cm) and shearing rate ({gamma}{approx}300kHz). Edge turbulence and cross-field transport are modified by changing the bias voltage (V{sub bias}) on the obstacle and the axial magnetic field (B{sub z}) strength. In cases with low V{sub bias} and large B{sub z}, improved plasma confinement is observed, along with steeper edge density gradients. The radially sheared flow induced by ExB drift dramatically changes the cross-phase between density and potential fluctuations, which causes the wave-induced particle flux to reverse its direction across the shear layer. In cases with higher bias voltage or smaller B{sub z}, large radial transport and rapid depletion of the central plasma density are observed. Two-dimensional cross-correlation measurement shows that a mode with azimuthal mode number m=1 and large radial correlation length dominates the outward transport in these cases. Linear analysis based on a two-fluid Braginskii model suggests that the fluctuations are driven by both density gradient (drift wave like) and flow shear (Kelvin-Helmholtz like) at the plasma edge.

  10. A Model of Plasma Heating by Large-Scale Flow

    CERN Document Server

    Pongkitiwanichakul, P; Boldyrev, S; Mason, J; Perez, J C

    2015-01-01

    In this work we study the process of energy dissipation triggered by a slow large scale motion of a magnetized conducting fluid. Our consideration is motivated by the problem of heating the solar corona, which is believed to be governed by fast reconnection events set off by the slow motion of magnetic field lines anchored in the photospheric plasma. To elucidate the physics governing the disruption of the imposed laminar motion and the energy transfer to small scales, we propose a simplified model where the large-scale motion of magnetic field lines is prescribed not at the footpoints but rather imposed volumetrically. As a result, the problem can be treated numerically with an efficient, highly-accurate spectral method, allowing us to use a resolution and statistical ensemble exceeding those of the previous work. We find that, even though the large-scale deformations are slow, they eventually lead to reconnection events that drive a turbulent state at smaller scales. The small-scale turbulence displays many...

  11. CHARGE BOTTLE FOR A MASS SEPARATOR

    Science.gov (United States)

    Davidson, P.H.

    1959-07-01

    Improved mass separator charge bottles are described for containing a dense charge of a chemical compound of copper, nickel, lead or other useful substance which is to be vaporized, and to the method of utilizing such improvcd charge bottles so that the chemical compound is vaporized from the under surface of the charge and thus permits the non-volatile portion thereof to fall to the bottom of the charge bottle where it does not form an obstacle to further evaporation. The charge bottle comprises a vertically disposed cylindrical portion, an inner re-entrant cylindrical portion extending axially and downwardly into the same from the upper end thereof, and evaporative source material in the form of a chemical compound compacted within the upper annular pontion of the charge bottle formed by the re-entrant cylindrical portion, whereby vapor from the chemical compound will pass outwardly from the charge bottle through an apertured closure.

  12. Current collection by a long conducting cylinder in a flowing magnetized plasma

    Science.gov (United States)

    Singh, Nagendra; Vashi, Bharat I.

    1990-01-01

    The numerical techniques, the definitions, and the normalizations used in the simulations of plasma flow past a long conducting cylinder with a magnetic field along the cylinder axis are described. The effect of cross-field plasma transport on the current collection without any contribution to the current from the field-aligned motion of the plasma particles is highlighted. The electric fields in the structure create a two-cell circulation of the electrons near the cylinder. The cell in the wake region has negative potentials. A fan-shaped circulation cell forms around the cylinder and in this cell the potential is generally positive. The geometry and the size of this positive cell affect the current collection. The potential structure around the cylinder is examined, along with its effect on the current collection and its oscillatory behavior. The variation of the time-average current as a function of the relative motion between the plasma and the cylinder is also investigated.

  13. Microstructure of TiCrN coatings, formed under the influence of the plasma flows of variable density

    International Nuclear Information System (INIS)

    Ternary TiCrN coatings were formed by condensation with the ion bombardment of the samples surface combining the plasma flows of titanium and chromium of variable density in a residual nitrogen atmosphere. SEM-investigations showed that the formation of the columnar structure with average columns size of 80-90 nm is characteristic for constant total plasma flow. And for variable total plasma flow the coatings with the variable microstructure are formed: from columnar to granular ones. The formation of weak columnar grow structure is followed by the formation of granular one with plasma flow increase. In this case the columns size corresponds to that of globular grains (30-40 nm). The other effect is observed with the plasma flow decrease: disordered structure (60 nm) is followed by weak columnar one (50 nm). (authors)

  14. Effects of Gas Flow Rate on the Discharge Characteristics of a DC Excited Plasma Jet

    Science.gov (United States)

    Li, Xuechen; Jia, Pengying; Di, Cong; Bao, Wenting; Zhang, Chunyan

    2015-09-01

    A direct current (DC) source excited plasma jet consisting of a hollow needle anode and a plate cathode has been developed to form a diffuse discharge plume in ambient air with flowing argon as the working gas. Using optical and electrical methods, the discharge characteristics are investigated for the diffuse plasma plume. Results indicate that the discharge has a pulse characteristic, under the excitation of a DC voltage. The discharge pulse corresponds to the propagation process of a plasma bullet travelling from the anode to the cathode. It is found that, with an increment of the gas flow rate, both the discharge plume length and the current peak value of the pulsed discharge decrease in the laminar flow mode, reach their minima at about 1.5 L/min, and then slightly increase in the turbulent mode. However, the frequency of the pulsed discharge increases in the laminar mode with increasing the argon flow rate until the argon flow rate equals to about 1.5 L/min, and then slightly decreases in the turbulent mode. supported by National Natural Science Foundation of China (Nos. 10805013, 11375051), Funds for Distinguished Young Scientists of Hebei Province, China (No. A2012201045), Department of Education for Outstanding Youth Project of China (No. Y2011120), and Youth Project of Hebei University of China (No. 2011Q14)

  15. Screening of external magnetic perturbation fields due to sheared plasma flow

    Science.gov (United States)

    Li, L.; Liu, Y. Q.; Liang, Y.; Wang, N.; Luan, Q.; Zhong, F. C.; Liu, Y.

    2016-09-01

    Within the single fluid resistive magnetohydrodynamic model, systematic toroidal modelling efforts are devoted to investigate the plasma response induced screening of the applied external 3D magnetic field perturbations in the presence of sheared toroidal flow. One particular issue of interest is addressed, when the local flow speed approaches zero at the perturbation rational surface inside the plasma. Subtle screening physics, associated with the favourable averaged toroidal curvature effect (the GGJ effect (Glasser et al 1975 Phys. Fluids 7 875)), is found to play an essential role during slow flow near the rational surface by enhancing the screening at reduced flow. A strong cancellation effect between different terms of Ohm’s law is discovered, leading to different screening physics in the GGJ regime, as compared to that of conventional screening of the typical resistive-inertial regime occurring at faster flow. These modelling results may be applicable to interpret certain mode locking experiments, as well as type-I edge localized mode suppression experiments, with resonant magnetic field perturbations being applied to tokamak plasmas at low input toroidal torque.

  16. Collisionless flow and end loss from a high-energy theta-pinch plasma

    International Nuclear Information System (INIS)

    End-loss experiments on the high-energy (T/sub e/+T/sub i/=3.3 keV, n/sub e/=1.5 x 1016 cm-3) 5 m Scylla IV-P theta pinch are reported. The evolution of the theta-pinch plasma parameters in the presence of axial losses and the behavior of the exhausting plasma near the ends of the device have been investigated. The measured decay of the theta-pinch plasma electron temperature agrees with code predictions based on classical axial thermal conduction losses. However, the axial ion heat flux is found to be unmeasurably small in the collisionless ion plasma. Energy-line-density measurements at the coil midplane also agree with code predictions and provide evidence of inward traveling rarefaction-like waves. At the theta-pinch ends, the exhausting plasma is comprised of a collimated plasma core which remains radially confined for tens of centimeters, strongly convects magnetic fields, and contains the bulk of the ejected plasma. This collimated core is surrounded by a plasma annulus that expands rapidly to the walls after leaving the theta-pinch coil. The radially confined exhaust plasma is successfully modeled as one-dimensional flow through a converging-diverging nozzle. The new results obtained in Scylla IV-P have led to a re-analysis of the particle end-loss data obtained in previous experiments. The subsequent comparison of experiments and theory shows that the normalized particle end-loss time is independent of both the plasma beta and collisionality regime

  17. Toroidal modeling of interaction between resistive wall mode and plasma flow

    CERN Document Server

    Liu, Yueqiang

    2013-01-01

    The non-linear interplay between the resistive wall mode (RWM) and the toroidal plasma flow is numerically investigated in a full toroidal geometry, by simultaneously solving the initial value problems for the n=1 RWM and the n=0 toroidal force balance equation. Here n is the toroidal mode number. The neoclassical toroidal viscous torque is identified as the major momentum sink that brakes the toroidal plasma flow during the non-linear evolution of the RWM. This holds for a mode that is initially either unstable or stable. For an initially stable RWM, the braking of the flow, and hence the eventual growth of the mode, depends critically on the initial perturbation amplitude.

  18. Measurements of the flow rate of dense plasmas by means of the Doppler effect

    International Nuclear Information System (INIS)

    Following a listing of different methods of the flow rate determination of flowing dense plasmas, 1) the Doppler effect measuring concept in combination with the Fabry-Perot interferometer is described, 2) the signal-noise ratio of the measuring device is dealt with, and 3) the plasma torch, the optical arrangement as well as signal detection and compensation control are described. The Ar-I line with 4,158 A was used for the flow rate measurements. The results were in good agreement with the results reported by Ahlborn (method: propagation of a decrease in luminescence). Finally, 1) three causes of errors of measurement are discussed, 2) possible methods of improving the measuring technique are presented, and 3) comparisons are made with similar and related methods. (GG/AK)

  19. Vertical flow in the Thermoelectric Liquid Metal Plasma Facing Structures (TELS) facility at Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W. [Center for Plasma-Material Interaction, Dept. Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana (United States); Fiflis, P., E-mail: fiflis1@illinois.edu [Center for Plasma-Material Interaction, Dept. Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana (United States); Szott, M.; Kalathiparambil, K.; Jung, S.; Christenson, M.; Haehnlein, I.; Kapat, A. [Center for Plasma-Material Interaction, Dept. Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana (United States); Andruczyk, D. [Center for Plasma-Material Interaction, Dept. Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana (United States); PPPL (United States); Curreli, D.; Ruzic, D.N. [Center for Plasma-Material Interaction, Dept. Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana (United States)

    2015-08-15

    Flowing liquid metal PFCs may offer a solution to the issues faced by solid divertor materials in tokamak plasmas. The Liquid–Metal Infused Trenches (LiMIT) concept of Illinois Ruzic et al. (2011) is a liquid metal plasma facing structure which employs thermoelectric magnetohydrodynamic (TEMHD) effects to self-propel lithium through a series of trenches. The combination of an incident heat flux and a magnetic field provide the driving mechanism. Tests have yielded experimental lithium velocities under different magnetic fields, which agree well with theoretical predictions Xu et al. (2013). The thermoelectric force is expected to overcome gravity and be able to drive lithium flow along an arbitrary direction and the strong surface tension of liquid lithium is believed to maintain the surface when Li flows in open trenches. This paper discusses the behavior of the LiMIT structure when inclined to an arbitrary angle with respect to the horizontal.

  20. Bottling process and closure choice influence oxygen levels in wine and wine post-bottling development

    OpenAIRE

    Dimkou, Evdokia

    2013-01-01

    In the framework of several bottling trials replicating typical winery conditions, Riesling wines were bottled with different levels of dissolved and headspace oxygen and were sealed with co-extruded or screw cap closures in order to investigate the impact of oxygen at bottling as well as oxygen´s ingress through the closure on wine development. Using the luminescence technology, dissolved and headspace oxygen, as well as closure´s oxygen transfer rate were monitored during bottle storage and...

  1. Fluctuation-induced shear flow and energy transfer in plasma interchange turbulence

    International Nuclear Information System (INIS)

    Fluctuation-induced E × B shear flow and energy transfer for plasma interchange turbulence are examined in a flux-driven system with both closed and open magnetic field lines. The nonlinear evolution of interchange turbulence shows the presence of two confinement regimes characterized by low and high E × B flow shear. In the first regime, the large-scale turbulent convection is dominant and the mean E × B shear flow is at a relatively low level. By increasing the heat flux above a certain threshold, the increased turbulent intensity gives rise to the transfer of energy from fluctuations to mean E × B flows. As a result, a transition to the second regime occurs, in which a strong mean E × B shear flow is generated

  2. Transport Due to Intermittent Events and Plasma Flow Shear in Magnetized Plasmas

    International Nuclear Information System (INIS)

    In the Reversed Field Pinch experiment RFX a highly sheared ExB flow is observed in the edge region, with shear value close to the value required for turbulence suppression or reduction. Recent observations have shown that almost 50% of particle flux due to turbulence is due to intermittent events which tend to cluster during magnetic relaxation phase. These events have been associated in RFX to vortex like structures whose rotation direction depends on the local value of the mean ExB flow shear

  3. Global model assessments of the effects of flowing lithium curtain on reactor core plasma performance

    International Nuclear Information System (INIS)

    A global model assessments of the effects of a flowing lithium curtain on plasma has been performed, which is utilized as the first wall for the engineering outline design of the Fusion Experimental Breeder (FEB-E). The relationships between the surface temperature of a liquid lithium curtain and the mean effective plasma charge, fuel dilution and the reduction factor of produced fusion power have been obtained. Studies indicate that under normal operation circumstances, the evaporation of liquid lithium does not affect the mean effective plasma charge seriously, but the effects on the fuel dilution and fusion power is more sensitive. The authors have investigated the relationships between the flow velocity of the liquid lithium curtain and the rise of surface temperature based on the operation scenario II of FEB-E design with reversed shear configuration and higher power density. Results show even when the flow velocity of liquid lithium curtain is as low as 0.5 m/s, the effects of evaporation from the curtain on plasma are negligible. (authors)

  4. Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W. X.; Hahm, T. S.; Ethier, S.; Rewoldt, G.; Tang, W. M.; Lee, W. W.; Diamond, P. H.

    2011-03-20

    Toroidal plasma flow driven by turbulent torque associated with nonlinear residual stress generation is shown to recover the observed key features of intrinsic rotation in experiments. Specifically, the turbulence-driven intrinsic rotation scales close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing empirical scalings obtained from a large experimental data base. The effect of magnetic shear on the symmetry breaking in the parallel wavenumber spectrum is identified. The origin of the current scaling is found to be the enhanced kll symmetry breaking induced by increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic rotation on the pressure gradient comes from the fact that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving the residual stress, are increased with the strength of the turbulence drives, which are R/LTe and R/Lne for the collisionless trapped electron mode (CTEM). Highlighted results also include robust radial pinches in toroidal flow, heat and particle transport driven by CTEM turbulence, which emerge "in phase", and are shown to play important roles in determining plasma profiles. Also discussed are experimental tests proposed to validate findings from these gyrokinetic simulations.

  5. Analytical and Numerical Modeling of Plasma Flow Around a Circular Boundary

    Science.gov (United States)

    Scott, Roger B.

    2016-05-01

    The flow of plasma around a circular boundary is a topic of great importance for solar physics, in which individual flux tubes are often treated as discrete elements that interact with their environment through the forces exerted across their surfaces. This scenario has been suggested by McKenzie (2000) and later refined by Savage et al. (2012) as an explanation for the dark lanes that commonly form in supra-arcade fan structures, i.e. SADs. Here we present a rigorous model in which a retracting flux tube serves as an interior boundary for the surrounding magnetic field, with the associated plasma forced to flow around it. Through a zero-β analytical solution we show that under certain circumstances these flows lead to shocks that can extend far out into the unreconnected field, altering the plasma properties in the affected region. We then employ a numerical simulation that relaxes the low-β assumption and we find that the collimated shocks described in our previous study are recovered for plasma β in the range of 0 energy of the fluid exceeds the internal energy of both the fluid and the magnetic field, thereby leading to the formation of unconfined, fast-mode magnetohydrodynamic shocks, even in the limit of small β.

  6. A key inactivation factor of HeLa cell viability by a plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Takehiko; Yokoyama, Mayo [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Johkura, Kohei, E-mail: sato@ifs.tohoku.ac.jp [Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621 (Japan)

    2011-09-21

    Recently, a plasma flow has been applied to medical treatment using effects of various kinds of stimuli such as chemical species, charged particles, heat, light, shock wave and electric fields. Among them, the chemical species are known to cause an inactivation of cell viability. However, the mechanisms and key factors of this event are not yet clear. In this study, we focused on the effect of H{sub 2}O{sub 2} in plasma-treated culture medium because it is generated in the culture medium and it is also chemically stable compared with free radicals generated by the plasma flow. To elucidate the significance of H{sub 2}O{sub 2}, we assessed the differences in the effects of plasma-treated medium and H{sub 2}O{sub 2}-added medium against inactivation of HeLa cell viability. These two media showed comparable effects on HeLa cells in terms of the survival ratios, morphological features of damage processes, permeations of H{sub 2}O{sub 2} into the cells, response to H{sub 2}O{sub 2} decomposition by catalase and comprehensive gene expression. The results supported that among chemical species generated in a plasma-treated culture medium, H{sub 2}O{sub 2} is one of the main factors responsible for inactivation of HeLa cell viability. (fast track communication)

  7. Study of plasma induced flow forming mechanism using the Schlieren method

    Science.gov (United States)

    Shimura, Naohiko; Tanaka, Motofumi; Amemori, Kiyoyuki; Yasui, Hiroyuki

    2015-09-01

    As one of the active flow control device, a non-thermal dielectric barrier discharge plasma actuator is well known and paid attention. However, the effect of applied voltage waveform to the spatial distribution of the electric discharge and induced flow is not understood. We visualized spacio-temporal evolution of an air density due to the induced flow by Schlieren imaging method with high speed camera, and discuss the relationship between the time variation of applied voltage dV/dt and induced flow. Sinusoidal and triangular waveform voltages were applied to the plasma actuator. It was observed that induced flow was formed with phase of dV/dt0, the streamer easily progresses to the dielectric surface, and the dielectric surface is charged up immediately and electric field is weakened by the surface charge, and then induced flow is not formed. On the other hand, in the case of dV/dt<0, because streamer is difficult to progress, the electric field to accelerate the positive ions is not cancelled with surface charge.

  8. Experimental investigation of flow induced dust acoustic shock waves in a complex plasma

    CERN Document Server

    Jaiswal, S; Sen, A

    2016-01-01

    We report on experimental observations of flow induced large amplitude dust-acoustic shock waves (DASW) in a complex plasma. The experiments have been carried out in a $\\Pi$ shaped DC glow discharge experimental device using kaolin particles as the dust component in a background of Argon plasma. A strong supersonic flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change of gas flow rate is used to trigger the onset of high velocity dust acoustic shocks whose dynamics are captured by fast video pictures of the evolving structures. The physical characteristics of these shocks are delineated through a parametric scan of their dynamical properties over a range of flow speeds and potential hill heights. The observed evolution of the shock waves and their propagation characteristics are found to compare well with model numerical results based on a m...

  9. Experimental investigation of flow induced dust acoustic shock waves in a complex plasma

    Science.gov (United States)

    Jaiswal, S.; Bandyopadhyay, P.; Sen, A.

    2016-08-01

    We report on experimental observations of flow induced large amplitude dust-acoustic shock waves in a complex plasma. The experiments have been carried out in a Π shaped direct current glow discharge experimental device using kaolin particles as the dust component in a background of Argon plasma. A strong supersonic flow of the dust fluid is induced by adjusting the pumping speed and neutral gas flow into the device. An isolated copper wire mounted on the cathode acts as a potential barrier to the flow of dust particles. A sudden change in the gas flow rate is used to trigger the onset of high velocity dust acoustic shocks whose dynamics are captured by fast video pictures of the evolving structures. The physical characteristics of these shocks are delineated through a parametric scan of their dynamical properties over a range of flow speeds and potential hill heights. The observed evolution of the shock waves and their propagation characteristics are found to compare well with model numerical results based on a modified Korteweg-de-Vries-Burgers type equation.

  10. Monitoring Temperature in High Enthalpy Arc-heated Plasma Flows using Tunable Diode Laser Absorption Spectroscopy

    Science.gov (United States)

    Martin, Marcel Nations; Chang, Leyen S.; Jeffries, Jay B.; Hanson, Ronald K.; Nawaz, Anuscheh; Taunk, Jaswinder S.; Driver, David M.; Raiche, George

    2013-01-01

    A tunable diode laser sensor was designed for in situ monitoring of temperature in the arc heater of the NASA Ames IHF arcjet facility (60 MW). An external cavity diode laser was used to generate light at 777.2 nm and laser absorption used to monitor the population of electronically excited oxygen atoms in an air plasma flow. Under the assumption of thermochemical equilibrium, time-resolved temperature measurements were obtained on four lines-of-sight, which enabled evaluation of the temperature uniformity in the plasma column for different arcjet operating conditions.

  11. Plasma flow reversals at the dayside magnetopause and the origin of the asymmetric polar cap convection

    International Nuclear Information System (INIS)

    A number of events have been observed in the Los Alamos/Garching fast plasma experiment data from ISEE 2 within ± 3 hours of noon wherein the y component of the plasmas flow within the low latitude boundary layer and magnetopause current layer is oppositely directed to that in the adjacent magnetosheath. When the y component, By, of the local magnetosheath magnetic field is positive, events of this nature are found preferentially in the northern dusk and southern dawn quadrants, and when By is negative, they are found preferentially in the opposite two quadrants. Plasma flows in these events are always also poleward, that is they are always directed away from the GSE equatorial plane. The observations are qualitatively and quantitatively consistent with previous observations of accelerated flows at the magnetopause and with models of magnetic reconnection, with the reconnection occurring at low latitudes near the GSE XY plane independent of the magnitude or the sign of the y component of the local magnetosheath magnetic field. Local magnetic shears at the magnetopause for these events range from 60 to 180 degs, which, together with the occurrence of these events at low latitudes, does not tend to support the antiparallel merging hypothesis. These observations of By-dependent flow reversals provide a graphic demonstration of how asymmetric polar cap convection and related phenomena, such as the Svalgaard-Mansurov effect, originate in magnetic reconnection at the dayside magnetopause

  12. Time-Dependent 2D Modeling of Magnetron Plasma Torch in Turbulent Flow

    Institute of Scientific and Technical Information of China (English)

    LI Lincun; XIA Weidong

    2008-01-01

    A theoretical model is presented to describe the electromagnetic, heat transfer and fluid flow phenomena within a magnetron plasma torch and in the resultant plume, by using a commercial computational fluid dynamics (CFD) code FLUENT. Specific calculations are pre-sented for a pure argon system (i.e., an argon plasma discharging into an argon environment), operated in a turbulent mode. An important finding of this work is that the external axial mag-netic field (AMF) may have a significant effect on the behavior of arc plasma and thus affects the resulting plume. The AMF impels the plasma to retract axially and expand radially. As a result, the plasma intensity distribution on the cross section of torch seems to be more uniform. Numerical results also show that with AMF, the highest plasma temperature decreases and the anode arc root moves upstream significantly, while the current density distribution at the anode is more concentrated with a higher peak value. In addition, the use of AMF then induces a strong backflow at the torch spout and its magnitude increases with the AMF strength but decreases with the inlet gas velocity.

  13. Influence of Downstream Flow on Conduction Phase of Coaxial Plasma Opening Switch

    Institute of Scientific and Technical Information of China (English)

    XU Xiang; WANG Younian

    2008-01-01

    Plasma behaviour and the scaling relations in a coaxial plasma opening switch (POS) using hydrogen plasma are studied self-consistently based on the two-dimensional magnetohydro-dynamic (MHD) equations in conjunction with the generalized Ohm's law. The vacuum region on the right of POS is included in the model and the influence of downstream flow on the conduction characteristics is discussed. It is found that with the penetration of magnetic field, the pure hydro-gen plasma is pushed downstream significantly; and POS still conducts current after the magnetic field arrives at the load edge of POS, which is different from the previous experimental results in a multispecies POS. It is because that the noticeable downstream plasma in the pure hydrogen POS may continue to conduct the current, while in the multispecies POS, the downstream plasma is unimportant so that the conduction phase ends soon after the magnetic field reaches the load edge. The scaling relation obtained from the simulations including the downstream region is consistent with the experimental results.

  14. Influence of Downstream Flow on Conduction Phase of Coaxial Plasma Opening Switch

    International Nuclear Information System (INIS)

    Plasma behaviour and the scaling relations in a coaxial plasma opening switch (POS) using hydrogen plasma are studied self-consistently based on the two-dimensional magnetohydrodynamic (MHD) equations in conjunction with the generalized Ohm's law. The vacuum region on the right of POS is included in the model and the influence of downstream flow on the conduction characteristics is discussed. It is found that with the penetration of magnetic field, the pure hydrogen plasma is pushed downstream significantly; and POS still conducts current after the magnetic field arrives at the load edge of POS, which is different from the previous experimental results in a multispecies POS. It is because that the noticeable downstream plasma in the pure hydrogen POS may continue to conduct the current, while in the multispecies POS, the downstream plasma is unimportant so that the conduction phase ends soon after the magnetic field reaches the load edge. The scaling relation obtained from the simulations including the downstream region is consistent with the experimental results.

  15. Seminal plasma applied post-thawing affects boar sperm physiology: a flow cytometry study.

    Science.gov (United States)

    Fernández-Gago, Rocío; Domínguez, Juan Carlos; Martínez-Pastor, Felipe

    2013-09-01

    Cryopreservation induces extensive biophysical and biochemical changes in the sperm. In the present study, we used flow cytometry to assess the capacitation-like status of frozen-thawed boar spermatozoa and its relationship with intracellular calcium, assessment of membrane fluidity, modification of thiol groups in plasma membrane proteins, reactive oxygen species (ROS) levels, viability, acrosomal status, and mitochondrial activity. This experiment was performed to verify the effect of adding seminal plasma on post-thaw sperm functions. To determine these effects after cryopreservation, frozen-thawed semen from seven boars was examined after supplementation with different concentrations of pooled seminal plasma (0%, 10%, and 50%) at various times of incubation from 0 to 4 hours. Incubation caused a decrease in membrane integrity and an increase in acrosomal damage, with small changes in other parameters (P > 0.05). Although 10% seminal plasma showed few differences with 0% (ROS increase at 4 hours, P boar spermatozoa, possibly through membrane changes and ROS increase. Although some effects were detrimental, the stimulatory effect of 50% seminal plasma could favor the performance of post-thawed boar semen, as showed in the field (García JC, Domínguez JC, Peña FJ, Alegre B, Gonzalez R, Castro MJ, Habing GG, Kirkwood RN. Thawing boar semen in the presence of seminal plasma: effects on sperm quality and fertility. Anim Reprod Sci 2010;119:160-5). PMID:23756043

  16. Development of Syringe/Bottle Hybrids for Sampling Slurries

    International Nuclear Information System (INIS)

    A convenient and effective sample bottle system based on simple modifications of disposable plastic syringes and bottles has been devised and tested for slurry samples. Syringe/ bottle hybrids (hereafter referred to as syringe bottles) have the convenience of regular flat-bottom bottles with screw cap closures. In addition, the syringe imparts a sliding and adjustable bottom to the bottle that forces the entire contents from the bottle. The system was designed especially to collect samples for high temperature work-ups of DWPF slurry samples. The syringe bottles together with fixed-bottom sample vial inserts would provide the DWPF with convenient and reliable methods for dealing with slurry samples

  17. The influence of pet containers on antimony concentration in bottled drinking water

    Directory of Open Access Journals (Sweden)

    Perić-Grujić Aleksandra A.

    2010-01-01

    Full Text Available Antimony trioxide (Sb2O3 is the most frequently used catalyst in the polyethylene terephthalate (PET manufacture. As a result, antimony is incorporated into PET bottles at concentration level of 100-300 mg/kg. PET containers are used for drinking water and beverages, as well as food packaging and in the pharmaceutical industry. Thus, it is important to understand the factors that may influence the release of antimony from the catalysts into water and other products, since antimony is potentially toxic trace element. In this paper, the antimony content in nine brands of bottled mineral and spring water from Serbia, and seven brands of bottled mineral and spring water from EU countries was analyzed. The measurements were conducted using the inductively coupled plasma-mass spectrometry (ICP-MS technique. In the all examined samples the antimony concentration was bellow the maximum contaminant level of 5 μg/L prescribed by the Serbian and EU regulations. Comparison of the content of antimony in PET bottled waters with the content of antimony in water bottled commercially in glass and the natural content of antimony in pristine groundwaters, provides explicit evidence of antimony leaching from PET containers. Since waters bottled in PET have much greater concentration ratio of Sb to Pb than corresponding pristine groundwaters, it can be assumed that bottled waters cannot be used as the relavant source for the study of the natural antimony content in groundwaters. There is a clear relation between the quality of water in bottles (composition, ion strength and antimony leaching rate. Moreover, while the rate of antimony leaching is slow at temperatures below 60 oC, at the temperature range of 60-80 oC antimony release occurs and reaches maximum contaminant level rapidly. As antimony can cause both acute and chronic health problems, factors that promote the increase of antimony concentration should be avoided.

  18. Ricci dynamo stretch-shear plasma flows and magnetic energy bounds

    CERN Document Server

    de Andrade, Garcia

    2009-01-01

    Geometrical tools, used in Einstein's general relativity (GR), are applied to dynamo theory, in order to obtain fast dynamo action bounds to magnetic energy, from Killing symmetries in Ricci flows. Magnetic field is shown to be the shear flow tensor eigendirection, in the case of marginal dynamos. Killing symmetries of the Riemann metric, bounded by Einstein space, allows us to reduce the computations. Techniques used are similar to those strain decomposition of the flow in Sobolev space, recently used by Nu\\~nez [JMP \\textbf{43} (2002)] to place bounds in the magnetic energy in the case of hydromagnetic dynamos with plasma resistivity. Contrary to Nu\\~nez case, we assume that the dynamos are kinematic, and the velocity flow gradient is decomposed into expansion, shear and twist. The effective twist vanishes by considering that the frame vorticity coincides with Ricci rotation coefficients. Eigenvalues are here Lyapunov exponents. In analogy to GR, where curvature plays the role of gravity, here Ricci curvatu...

  19. A continuous flow micro filtration device for plasma/blood separation using submicron vertical pillar gap structures

    International Nuclear Information System (INIS)

    This work demonstrates a continuous flow plasma/blood separator using a vertical submicron pillar gap structure. The working principle of the proposed separator is based on size exclusion of cells through cross-flow filtration, in which only plasma is allowed to pass through submicron vertical pillars located tangential to the main flow path of the blood sample. The maximum filtration efficiency of 99.9% was recorded with a plasma collection rate of 0.67 µl min−1 for an input blood flow rate of 12.5 µl min−1. The hemolysis phenomenon was observed for an input blood flow rate above 30 µl min−1. Based on the experimental results, we can conclude that the proposed device shows potential for the application of on-chip plasma/blood separation as a part of integrated point-of-care (POC) diagnostics systems. (technical note)

  20. Control of supersonic axisymmetric base flows using passive splitter plates and pulsed plasma actuators

    Science.gov (United States)

    Reedy, Todd Mitchell

    An experimental investigation evaluating the effects of flow control on the near-wake downstream of a blunt-based axisymmetric body in supersonic flow has been conducted. To better understand and control the physical phenomena that govern these massively separated high-speed flows, this research examined both passive and active flow-control methodologies designed to alter the stability characteristics and structure of the near-wake. The passive control investigation consisted of inserting splitter plates into the recirculation region. The active control technique utilized energy deposition from multiple electric-arc plasma discharges placed around the base. The flow-control authority of both methodologies was evaluated with experimental diagnostics including particle image velocimetry, schlieren photography, surface flow visualization, pressure-sensitive paint, and discrete surface pressure measurements. Using a blowdown-type wind tunnel reconstructed specifically for these studies, baseline axisymmetric experiments without control were conducted for a nominal approach Mach number of 2.5. In addition to traditional base pressure measurements, mean velocity and turbulence quantities were acquired using two-component, planar particle image velocimetry. As a result, substantial insight was gained regarding the time-averaged and instantaneous near-wake flow fields. This dataset will supplement the previous benchmark point-wise laser Doppler velocimetry data of Herrin and Dutton (1994) for comparison with new computational predictive techniques. Next, experiments were conducted to study the effects of passive triangular splitter plates placed in the recirculation region behind a blunt-based axisymmetric body. By dividing the near-wake into 1/2, 1/3, and 1/4 cylindrical regions, the time-averaged base pressure distribution, time-series pressure fluctuations, and presumably the stability characteristics were altered. While the spatial base pressure distribution was

  1. Interfacial properties of bottle-brush polyelectrolytes

    DEFF Research Database (Denmark)

    Claesson, P. M.; Naderi, A.; Iruthayaraj, J.; Pettersson, T.; Vareikis, A.; Makuska, R.; Iruthayaraj, Joseph

    This article is focused on interfacial properties of bottle brush polyelectrolytes, where side-chains are attached along a polymer backbone. This class of polymer has been much less studied than block copolymers, which is particularly true for bottle brush polyelectrolytes with a high graft density...

  2. Structure of the near-Earth plasma sheet during tailward flows

    Directory of Open Access Journals (Sweden)

    A. Runov

    2008-03-01

    Full Text Available A detailed analysis of successive tailward flow bursts in the near-Earth magnetotail (X~−19 RE plasma sheet is performed on the basis of in-situ multi-point observations by the Cluster spacecraft on 15 September 2001. The tailward flows were detected during a northward IMF interval, 2.5 h after a substorm expansion. Each flow burst (Vx<300 km/s was associated with local auroral activation. Enhancements of the parallel and anti-parallel ~1 keV electron flux were detected during the flows. The spacecraft configuration enables to monitor the neutral sheet (Bx≈0 and the level of Bx≈10–15 nT simultaneously, giving a possibility to distinguish between closed plasmoid-like structures and open NFTE-like surges. The data analysis shows NFTE-like structures and localized current filaments embedded into the tailward plasma flow. 3-D shapes of the structures were reconstructed using the four-point magnetic filed measurements and the particle data.

  3. Flow separation control on swept wing with nanosecond pulse driven DBD plasma actuators

    Directory of Open Access Journals (Sweden)

    Zhao Guangyin

    2015-04-01

    Full Text Available A 15° swept wing with dielectric barrier discharge plasma actuator is designed. Experimental study of flow separation control with nanosecond pulsed plasma actuation is performed at flow velocity up to 40 m/s. The effects of the actuation frequency and voltage on the aerodynamic performance of the swept wing are evaluated by the balanced force and pressure measurements in the wind tunnel. At last, the performances on separation flow control of the three types of actuators with plane and saw-toothed exposed electrodes are compared. The optimal actuation frequency for the flow separation control on the swept wing is detected, namely the reduced frequency is 0.775, which is different from 2-D airfoil separation control. There exists a threshold voltage for the low swept wing flow control. Before the threshold voltage, as the actuation voltage increases, the control effects become better. The maximum lift is increased by 23.1% with the drag decreased by 22.4% at 14°, compared with the base line. However, the best effects are obtained on actuator with plane exposed electrode in the low-speed experiment and the abilities of saw-toothed actuators are expected to be verified under high-speed conditions.

  4. Magnetohydrodynamic simulation of kink instability and plasma flow during sustainment of a coaxial gun spheromak

    International Nuclear Information System (INIS)

    Kink instability and the subsequent plasma flow during the sustainment of a coaxial gun spheromak are investigated by three-dimensional nonlinear magnetohydrodynamic simulations. Analysis of the parallel current density λ profile in the central open column revealed that the n = 1 mode structure plays an important role in the relaxation and current drive. The toroidal flow (vt ≈ 37 km/s) is driven by magnetic reconnection occurring as a result of the helical kink distortion of the central open column during repetitive plasmoid ejection and merging. (author)

  5. Demonstration of a plasma mirror based on a laminar flow water film

    Energy Technology Data Exchange (ETDEWEB)

    Panasenko, Dmitriy; Shu, Anthony; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas; Toth, Csaba; Leemans, Wim

    2011-07-22

    A plasma mirror based on a laminar water film with low flow speed 0.5-2 cm/s has been developed and characterized, for use as an ultrahigh intensity optical reflector. The use of flowing water as atarget surface automatically results in each laser pulse seeing a new interaction surface and avoids the need for mechanical scanning of the target surface. In addition, the breakdown of water does notproduce contaminating debris that can be deleterious to vacuum chamber conditions and optics, such as is the case when using conventional solid targets. The mirror exhibits 70percent reflectivity, whilemaintaining high-quality of the reflected spot.

  6. Fluid Flow Modeling of Arc Plasma and Bath Circulation in DC Electric Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-hua; JIN Zhi-jian; ZHU Zi-shu

    2006-01-01

    A mathematical model describing the flow field, heat transfer and the electromagnetic phenomenon in a DC electric arc furnace has been developed. First the governing equations in the arc plasma region are solved and the calculated results of heat transfer, current density and shear stresses on the anode surface are used as boundary conditions in a model of molten bath. Then a two-dimensional time-dependent model is used to describe the flow field and electromagnetic phenomenon in the molten bath. Moreover, the effect of bottom electrode diameter on the circulation of molten bath is studied.

  7. Plasma flow and fast particles in a hypervelocity accelerator - A color presentation. [micrometeoroid simulation

    Science.gov (United States)

    Igenbergs, E. B.; Cour-Palais, B.; Fisher, E.; Stehle, O.

    1975-01-01

    A new concept for particle acceleration for micrometeoroid simulation was developed at NASA Marshall Space Flight Center, using a high-density self-luminescent fast plasma flow to accelerate glass beads (with a diameter up to 1.0 mm) to velocities between 15-20 km/sec. After a short introduction to the operation of the hypervelocity range, the eight-converter-camera unit used for the photographs of the plasma flow and the accelerated particles is described. These photographs are obtained with an eight-segment reflecting pyramidal beam splitter. Wratten filters were mounted between the beam splitter and the converter tubes of the cameras. The photographs, which were recorded on black and white film, were used to make the matrices for the dye-color process, which produced the prints shown.

  8. Ballooning instability of the earth's plasma sheet region in the presence of parallel flow

    Science.gov (United States)

    Lakhina, G. S.; Hameiri, E.; Mond, M.

    1990-01-01

    Stability of the plasma sheet and plasma sheet boundary layer against the ballooning mode instability is investigated. The equilibrium state of a two-dimensional plasma sheet configuration with parallel sheared flow is modeled. This equilibrium is shown to be ballooning unstable when delta-W is not positive definite, where delta-W is the potential energy. The eigenmode structure of the ballooning mode is found by imposing the boundary conditions that the waves are totally reflected from the ionosphere, and that no waves are coming in from infinity. The eigenmode structure of the unstable balloning modes is highly oscillatory, extending beyond about 100 R(E). The ballooning modes are thus a possible candidate for explaining the MHD waves and other dynamical events observed in the magnetotail by ISEE 3 and other spacecraft.

  9. Compressible turbulence with slow-mode waves observed in the bursty bulk flow of plasma sheet

    Science.gov (United States)

    Wang, Tieyan; Cao, Jinbin; Fu, Huishan; Meng, Xuejie; Dunlop, M.

    2016-03-01

    In this paper, we report the evidence of compressible turbulence with slow-mode waves in a bursty bulk flow of plasma sheet. This compressible turbulence is characterized by a multiscale (1-60 s) anticorrelation between plasma density and magnetic field strength. Besides, the magnetic compressibility spectrum stays nearly constant at all the measured frequencies. Furthermore, the turbulence energy distributions are anisotropic with k⊥ > k//, and the dispersion relation is consistent with slow-mode prediction. The fluctuations of density and magnetic field have similar double slope spectrum and kurtosis. These results suggest that the slow waves are involved in the intermittent turbulence cascade from MHD to ion kinetic scales, which may have significant implications for the energy transfer in the plasma sheet.

  10. Small angle neutron scattering on the matters radiated by impulse plasma flows

    International Nuclear Information System (INIS)

    Complete text of publication follows. By methods of small angle neutron scattering (neutron wavelength ∼ 0.478 nm) on two-crystal diffractometer the structural inhomogenities (defects, clusters, pores, etc.) were investigated. The inhomogenities were produced by the impulse hydrogen and nitride plasma flows on the surface of steel 12X18H10T, aluminum alloy Al-Cu-Mg and graphite. The energy density of plasma was varied from 0 to 120 J/cm2. The values of total macroscopic scattering cross-section in dependence of radiation dose significantly change. It reveals the structural transformations on the samples' surface due to plasma influence. The critical doses for the given types of samples, that determine start of the change of physical and mechanical properties, were calculated. Theoretical calculations and the small angle neutron scattering data are in good agreement as well as the experimental data obtained by electron microscopy and metallography measurements. (author)

  11. The fluoride content of bottled drinking waters.

    Science.gov (United States)

    Toumba, K J; Levy, S; Curzon, M E

    1994-04-01

    Sales of bottled drinking waters in the United Kingdom have tripled over the last 5 years. The fluoride content of 12 bottled waters purchased from two Leeds supermarkets was determined by both the direct and acid diffusion methods and found to vary from 0.10-0.80 mg/l fluoride (ie ppm fluoride). This article shows that bottled drinking waters contain differing concentrations of fluoride. There is no apparent difference between the direct and acid diffusion methods for the determination of fluoride concentrations of drinking waters. The manufacturers' labelling of fluoride concentrations are mainly inaccurate. Dentists should be aware of the fluoride concentrations of the drinking water of their child patients, be they municipal or bottled drinking water, when prescribing fluoride supplements. Also, some parents are using bottled waters to prepare baby milk formulations which themselves may contain high levels of fluoride and subject their children to the risk of dental fluorosis. PMID:8186036

  12. The impact of plasma induced flow on the boundary layer in a narrow channel

    Czech Academy of Sciences Publication Activity Database

    Procházka, Pavel P.; Uruba, Václav

    Les Ulis Cedex : E D P SCIENCES, 2015 - (Dančová, P.; Vít, T.), s. 509-514 ISSN 2100-014X. - (EPJ Web of Conferences). [Experimental Fluid Mechanics 2014. Český Krumlov (CZ), 18.11.2014-21.11.2014] R&D Projects: GA ČR(CZ) GP14-25354P Institutional support: RVO:61388998 Keywords : plasma actuator * flow control * channel Subject RIV: BK - Fluid Dynamics

  13. On the influence of plasma DBD actuator on the flow in a rectangular channel

    Czech Academy of Sciences Publication Activity Database

    Procházka, Pavel P.; Uruba, Václav

    2014-01-01

    Roč. 14, č. 1 (2014), s. 727-728. ISSN 1617-7061. [Annual Meeting of the International Association of Applied Mathematics and Mechanics /85./. Erlangen, 10.03.2014-14.03.2014] R&D Projects: GA ČR(CZ) GP14-25354P Institutional support: RVO:61388998 Keywords : plasma DBD * boundary layer * channel flow Subject RIV: BK - Fluid Dynamics http://onlinelibrary.wiley.com/doi/10.1002/pamm.201410346/abstract

  14. Modeling of plasma flow switches at low, intermediate and high energies

    International Nuclear Information System (INIS)

    Inductively stored pulsed power technology has been used over the past thirty years to produce multi-megaamp currents to implode low inductance loads and produce x-radiation. Because of the large difference in timescales for the delivery of magnetic energy to the load and the desire for high power x-radiation output (short timescale for the implosion), most inductively stored systems require at least one opening switch. The design and understanding of fast, efficient opening switches for multi-megaamp systems represents a long standing problem in pulsed power research. The Los Alamos Foil Implosion Project uses inductively stored magnetic energy to implode thin metallic liners. A plasma flow switch (PFS) has been investigated as the final pulse shaping step for this systems. The PFS consists of a wire array and a barrier foil located upstream from the load region. Several stages can be identified in the performance of the plasma flow switch. These are: (1) the vaporization of the wire array; (2) the assembly of the initiated plasma on tie barrier foil to form the switch plasma; (3) the motion of the switch plasma down the coaxial barrel; and (4) current switching to the load (the actual switching stage). The fourth stage affects the switch's efficiency, as well as the quality of the load implosion. Instabilities may develop during any of these four stages, and their presence may seriously degrade the structure of the switch plasma. Two primary criteria may be used to characterize good switching. The first is switching efficiency. A second criterion is transferred to the load during or after switching. This paper summarizes the computational design of the PFS experiments carried out on Pegasus 1. We conclude by considering the implications of these results for the design of a PFS for the higher energy regime (Procyon) regime

  15. Model and conservation laws of stimulated Brillouin backscattered in an inhomogeneous flowing plasma

    International Nuclear Information System (INIS)

    The physics of momentum transfer from the laser field to the plasma ions is studied in the context of stimulated Brillouin scattering (SBS). In long-pulse regime (>1 ns), the momentum deposition leads to local flow inhomogeneities and density modifications in laser hot spots and changes significantly the physics of interaction. A set of equations that describe the self-consistent evolution of the laser field propagation, the backscattered transverse wave, the longitudinal ion acoustic wave (JAW) and the background plasma hydrodynamic is presented through a fluid description. In standard decay regime, a new three-dimensional paraxial equation describing the excitation of IAW in inhomogeneous flowing plasma is given in quasi-neutral limit. In particular, the rigorous and detailed computations of global momentum conservation involving different approximation levels in our fluid model have been carried out. Thus, the compatibility between the paraxial equation and the momentum conservation law has been checked. A multi-dimensional and parallel code Hera has been used to solve our full set of fluid equations in realistic large-size plasmas (hohlraums, gas jets). The numerical simulations based on such a model have shown to be very efficient in terms of computing time. (authors)

  16. Evaluation of compatibility of flowing liquid lithium curtain for blanket with core plasma in fusion reactors

    International Nuclear Information System (INIS)

    A global model analysis of the compatibility of flowing liquid lithium curtain for blanket with core plasma has been performed. The relationships between the surface temperature of lithium curtain and mean effective plasma charges, fuel dilution and produced fusion power have been obtained. Results show that under normal circumstances, the evaporation of liquid lithium does not affect Zeff seriously, but affects fuel dilution and fusion power sensitively. The authors have investigated the relationships between the flow velocity of liquid lithium and its surface temperature rise based on the conditions of the option II of the fusion experimental breeder (FEB-E) design with reversed shear configuration and fairly high power density. The authors concluded that the effects of evaporation from liquid lithium curtain for FEB-E on plasma are negligible even if the flow velocity of liquid lithium is as low as 0.5 m·s-1. Finally, the sputtering yield of liquid lithium saturated by hydrogen isotopes is briefly discussed

  17. Temperature distribution in a low-temperature plasma flow from a self-reversed spectral profile

    International Nuclear Information System (INIS)

    A method is reported for restoring the temperature space distribution using the profile of a spectral line radiated in a low-temperature plasma flow. The main advantage of the method consists in using one-directional diagnostics. The calculations are based on the following assumptions: (a) the temperature distribution T(x) is symmetric; (b) it is represented by an analytical form with few parameters; (c) there is LTE in the plasma and the density of the emitting atoms is a known function of the temperature. A corresponding computer code for solving this inverse problem is realized. The model computation shows that the procedure of restoring T(x) is satisfactorily converging to a well defined solution. The method is used for diagnostics of a combustion products' plasma flow with an alkali seed. Typical parameters are: temperature on the axis 2500 K, width of the channel 0.16 m, alkali atom density 1021 m-3, flow velocity several hundreds m/s. The measurements are performed on the spectral doublet of potassium 766.5/769.9 nm. The temperature distributions T(x) obtained by solving the inverse problem are compared with T(x) calculated on the base of the theory of a two-dimensional turbulent boundary layer. (author)

  18. Fragmentation of electric currents in the solar corona by plasma flows

    Science.gov (United States)

    Nickeler, D. H.; Karlický, M.; Wiegelmann, T.; Kraus, M.

    2013-08-01

    Aims: We consider a magnetic configuration consisting of an arcade structure and a detached plasmoid, resulting from a magnetic reconnection process, as is typically found in connection with solar flares. We study spontaneous current fragmentation caused by shear and vortex plasma flows. Methods: An exact analytical transformation method was applied to calculate self-consistent solutions of the nonlinear stationary magnetohydrodynamic equations. The assumption of incompressible field-aligned flows implies that both the Alfvén Mach number and the mass density are constant on field lines. We first calculated nonlinear magnetohydrostatic equilibria with the help of the Liouville method, emulating the scenario of a solar eruptive flare configuration with plasmoids (magnetic ropes or current-carrying loops in 3D) and flare arcade. Then a Mach number profile was constructed that describes the upflow along the open magnetic field lines and implements a vortex flow inside the plasmoid. This Mach number profile was used to map the magnetohydrostatic equilibrium to the stationary one. Results: We find that current fragmentation takes place at different locations within our configuration. Steep gradients of the Alfvén Mach number are required, implying the strong influence of shear flows on current amplification and filamentation of the magnetohydrostatic current sheets. Crescent- or ring-like structures appear along the outer separatrix, butterfly structures between the upper and lower plasmoids, and strong current peaks close the lower boundary (photosphere). Furthermore, impressing an intrinsic small-scale structure on the upper plasmoid results in strong fragmentation of the plasmoid. Hence fragmentation of current sheets and plasmoids is an inherent property of magnetohydrodynamic theory. Conclusions: Transformations from magnetohydrostatic into magnetohydrodynamic steady-states deliver fine-structures needed for plasma heating and acceleration of particles and bulk

  19. Turbulent separated shear flow control by surface plasma actuator: experimental optimization by genetic algorithm approach

    Science.gov (United States)

    Benard, N.; Pons-Prats, J.; Periaux, J.; Bugeda, G.; Braud, P.; Bonnet, J. P.; Moreau, E.

    2016-02-01

    The potential benefits of active flow control are no more debated. Among many others applications, flow control provides an effective mean for manipulating turbulent separated flows. Here, a nonthermal surface plasma discharge (dielectric barrier discharge) is installed at the step corner of a backward-facing step ( U 0 = 15 m/s, Re h = 30,000, Re θ = 1650). Wall pressure sensors are used to estimate the reattaching location downstream of the step (objective function #1) and also to measure the wall pressure fluctuation coefficients (objective function #2). An autonomous multi-variable optimization by genetic algorithm is implemented in an experiment for optimizing simultaneously the voltage amplitude, the burst frequency and the duty cycle of the high-voltage signal producing the surface plasma discharge. The single-objective optimization problems concern alternatively the minimization of the objective function #1 and the maximization of the objective function #2. The present paper demonstrates that when coupled with the plasma actuator and the wall pressure sensors, the genetic algorithm can find the optimum forcing conditions in only a few generations. At the end of the iterative search process, the minimum reattaching position is achieved by forcing the flow at the shear layer mode where a large spreading rate is obtained by increasing the periodicity of the vortex street and by enhancing the vortex pairing process. The objective function #2 is maximized for an actuation at half the shear layer mode. In this specific forcing mode, time-resolved PIV shows that the vortex pairing is reduced and that the strong fluctuations of the wall pressure coefficients result from the periodic passages of flow structures whose size corresponds to the height of the step model.

  20. Coherence imaging and tomography of fields and flows in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.; Diallo, A.; Creese, M.; Blackwell, B.C. [Australian National Universityj, Canberra (Australia); Jaspers, R. [Eindhoven University of Technology, Eindhoven (Netherlands); Chung, J. [National Fusion Research Institute, Daejeon (Korea, Republic of); Allen, S.L.; Meyer, W.; Fenstermacher, M.E.; Porter, G.D.; Ellis, R.M. [Lawrence Livermore National Laboratory at General Atomics, San Diego (United States); Van Zeeland, M.E.; Boivin, R.L.; Brooks, N. [General Atomics, San Diego (United States)

    2011-07-01

    In the last few years we have developed various spatial heterodyne polarization interferometers for spectrally-resolved optical imaging of edge and core parameters in high temperature magnetized plasmas. Applications include imaging motional Stark effect and Zeeman effect polarimetry for determination of the magnetic field pitch angle, Thomson scattering, and passive and active (charge exchange recombination spectroscopy - CXRS) Doppler imaging of plasma temperature and flow. In this paper we summarize recent innovations in imaging instrumentation and will present first results of motional Stark effect imaging of the internal magnetic field on the TEXTOR tokamak and Doppler flow imaging in the H-1 heliac and DIII-D divertor. The TEXTOR instrument uses a hybrid spatio-temporal multiplexing approach to capture 2 dimensional images of the projected beam velocity and magnetic field vector fields. While the Doppler projection agrees very well with modeling, there are some discrepancies in the polarimetric image which appear to be related to imperfections in the optical coupling prism. This issue will be addressed during a new set of measurements commencing in April 2010. During 2009 we installed instruments for imaging flows in the divertor and scrape-off-layer in the DIII-D tokamak. In these experiments, single snapshot interferometric images of the plasma in CII 514 nm, and CIII 465 nm emission have been demodulated to obtain flow and ion temperature projections. Tomographic reconstructions of the flow fields show encouraging agreement with UEDGE modeling, pointing the way towards experiments that address important divertor transport issues in future. This document is composed of an abstract followed by the slides of the presentation. (authors)

  1. Online Coupling of Flow-Field Flow Fractionation and Single Particle Inductively Coupled Plasma-Mass Spectrometry: Characterization of Nanoparticle Surface Coating Thickness and Aggregation State

    Science.gov (United States)

    Surface coating thickness and aggregation state have strong influence on the environmental fate, transport, and toxicity of engineered nanomaterials. In this study, flow-field flow fractionation coupled on-line with single particle inductively coupled plasma-mass spectrometry i...

  2. Sheared magnetospheric plasma flows and discrete auroral arcs: a quasi-static coupling model

    Directory of Open Access Journals (Sweden)

    M. M. Echim

    2007-02-01

    Full Text Available We consider sheared flows in magnetospheric boundary layers of tangential discontinuity type, forming a structure that is embedded in a large-scale convergent perpendicular electric field. We construct a kinetic model that couples the magnetospheric structure with the topside ionosphere. The contribution of magnetospheric electrons and ionospheric electrons and ions is taken into account into the current-voltage relationship derived for an electric potential monotonically decreasing with the altitude. The solution of the current continuity equation gives the distribution of the ionospheric potential consistent with the given magnetospheric electric potential. The model shows that a sheared magnetospheric flow generates current sheets corresponding to upward field-aligned currents, field-aligned potential drops and narrow bands of precipitating energy, as in discrete auroral arcs. Higher velocity magnetospheric sheared flows have the tendency to produce brighter and slightly broader arcs. An increase in arc luminosity is also associated with enhancements of magnetospheric plasma density, in which case the structures are narrower. Finally, the model predicts that an increase of the electron temperature of the magnetospheric flowing plasma corresponds to slightly wider arcs but does not modify their luminosity.

  3. Investigation of radiative bow-shocks in magnetically accelerated plasma flows

    Energy Technology Data Exchange (ETDEWEB)

    Bott-Suzuki, S. C., E-mail: sbottsuzuki@ucsd.edu; Caballero Bendixsen, L. S.; Cordaro, S. W. [University of California San Diego, La Jolla, California 92093 (United States); Blesener, I. C.; Hoyt, C. L.; Cahill, A. D.; Kusse, B. R.; Hammer, D. A.; Gourdain, P. A.; Seyler, C. E.; Greenly, J. B. [Cornell University, Ithaca, New York 14850 (United States); Chittenden, J. P.; Niasse, N.; Lebedev, S. V. [Imperial College London, South Kensington, London SW7 2BW (United Kingdom); Ampleford, D. J. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2015-05-15

    We present a study of the formation of bow shocks in radiatively cooled plasma flows. This work uses an inverse wire array to provide a quasi-uniform, large scale hydrodynamic flow accelerated by Lorentz forces to supersonic velocities. This flow impacts a stationary object placed in its path, forming a well-defined Mach cone. Interferogram data are used to determine a Mach number of ∼6, which may increase with radial position suggesting a strongly cooling flow. Self-emission imaging shows the formation of a thin (<60 μm) strongly emitting shock region, where T{sub e} ∼ 40–50 eV, and rapid cooling behind the shock. Emission is observed upstream of the shock position which appears consistent with a radiation driven phenomenon. Data are compared to 2-dimensional simulations using the Gorgon MHD code, which show good agreement with the experiments. The simulations are also used to investigate the effect of magnetic field in the target, demonstrating that the bow-shocks have a high plasma β, and the influence of B-field at the shock is small. This consistent with experimental measurement with micro bdot probes.

  4. Plasma Sensor for High Bandwidth Mass-Flow Measurements at High Mach Numbers with RF Link Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposal is aimed at the development of a miniature high bandwidth (1 MHz class) plasma sensor for flow measurements at high enthalpies. This device uses a...

  5. Measurements of ion temperature and flow of pulsed plasmas produced by a magnetized coaxial plasma gun device using an ion Doppler spectrometer

    Science.gov (United States)

    Kitagawa, Y.; Sakuma, I.; Iwamoto, D.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    It is important to know surface damage characteristics of plasma-facing component materials during transient heat and particle loads such as type I ELMs. A magnetized coaxial plasma gun (MCPG) device has been used as transient heat and particle source in ELM simulation experiments. Characteristics of pulsed plasmas produced by the MCPG device play an important role for the plasma material interaction. In this study, ion temperature and flow velocity of pulsed He plasmas were measured by an ion Doppler spectrometer (IDS). The IDS system consists of a light collection system including optical fibers, 1m-spectrometer and a 16 channel photomultiplier tube (PMT) detector. The IDS system measures the width and Doppler shift of HeII (468.58 nm) emission line with the time resolution of 1 μs. The Doppler broadened and shifted spectra were measured with 45 and 135 degree angles with respect to the plasmoid traveling direction. The observed emission line profile was represented by sum of two Gaussian components to determine the temperature and flow velocity. The minor component at around the wavelength of zero-velocity was produced by the stationary plasma. As the results, the ion velocity and temperature were 68 km/s and 19 eV, respectively. Thus, the He ion flow energy is 97 eV. The observed flow velocity agrees with that measured by a time of flight technique.

  6. Hartmann flow with Braginsky viscosity: a test problem for intercluster plasma

    CERN Document Server

    Lyutikov, Maxim

    2008-01-01

    We consider a Hartmann layer, stationary flow of a viscose and resistive fluid between two plates with superimposed transverse magnetic field, in the limit of gyrotropic plasma, when viscosity across the field is strongly suppressed. For zero cross-field viscosity, the problem is not well posed, since viscosity then vanishes on the boundaries and in the middle of the layer, where there is no longitudinal field. An additional arbitrarily small isotropic viscosity allows one to find magnetic field and velocity profiles which are independent of this viscosity floor and different from flows with isotropic viscosity. Velocity sharply rises in a thin boundary layer, which thickness depends both on the Hartmann number and on the Lundquist number of the flow. The implication of the work is that, in simulating ICM dynamics it is imperative to use numerical schemes which take into account anisotropic viscosity. Although magnetic fields are dynamically subdominant in the ICM they do determine its the dissipative propert...

  7. Fragmentation of electric currents in the solar corona by plasma flows

    CERN Document Server

    Nickeler, Dieter H; Wiegelmann, Thomas; Kraus, Michaela

    2013-01-01

    We consider a magnetic configuration consisting of an arcade structure and a detached plasmoid, resulting from a magnetic reconnection process, as is typically found in connection with solar flares. We study spontaneous current fragmentation caused by shear and vortex plasma flows. An exact analytical transformation method was applied to calculate self-consistent solutions of the nonlinear stationary MHD equations. The assumption of incompressible field-aligned flows implies that both the Alfven Mach number and the mass density are constant on field lines. We first calculated nonlinear MHS equilibria with the help of the Liouville method, emulating the scenario of a solar eruptive flare configuration with plasmoids and flare arcade. Then a Mach number profile was constructed that describes the upflow along the open magnetic field lines and implements a vortex flow inside the plasmoid. This Mach number profile was used to map the MHS equilibrium to the stationary one. We find that current fragmentation takes p...

  8. Numerical Investigation of Flow Separation Control on a Highly Loaded Compressor Cascade by Plasma Aerodynamic Actuation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiaohu; LI Yinghong; WU Yun; ZHU Tao; LI Yiwen

    2012-01-01

    To discover the characteristic of separated flows and mechanism of plasma flow control on a highly loaded compressor cascade,numerical investigation is conducted.The simulation method is validated by oil flow visualization and pressure distribution.The loss coefficients,streamline patterns,and topology structure as well as vortex structure are analyzed.Results show thai the numbers of singular points increase and three pairs of additional singular points of topology structure on solid surface generate with the increase of angle of attack,and the total pressure loss increases greatly.There are several principal vortices inside the cascade passage.The pressure side leg of horse-shoe vortex coexists within a specific region together with passage vortex,but finally merges into the latter.Comer vortex exists independently and does not evolve from the suction side leg of horse-shoe vortex.One pair of radial coupling-vortex exists near blade trailing edge and becomes the main part of backflow on the suction surface.Passage vortex interacts with the concentrated shedding vortex and they evolve into a large-scale vortex rotating in the direction opposite to passage vortex.The singular points and separation lines represent the basic separation feature of cascade passage.Plasma actuation has better effect at low freestream velocity,and the relative reductions of pitch-averaged total pressure loss coefficient with different actuation layouts of five and two pairs of electrodes are up to 30.8% and 26.7% while the angle of attack is 2°.Plasma actuation changes the local topology structure,but does not change the number relation of singular points.One pair of additional singular point of topology structure generates with plasma actuation and one more reattachment line appears,both of which break the separation line on the suction surface.

  9. Self-regulated shear flow turbulence in confined plasmas: Basic concepts and potential applications to the L → H transition

    International Nuclear Information System (INIS)

    This paper describes developments in the theory of edge plasma turbulence in a differentially rotating plasma. The thesis that such systems are dynamically self-regulating is presented. Results indicate that relevant fluctuations will generate a predominantly curved flow. Similar, curvature is shown to be the predominant flow profile effect on fluctuations. A system fixed point is identified, the eigenfrequencies for small oscillations around it are calculated, and an over-all stability criterion is determined

  10. 27 CFR 27.208 - Liquor bottles denied entry.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Liquor bottles denied... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Requirements for Liquor Bottles § 27.208 Liquor bottles denied entry. Filled liquor bottles, not conforming to...

  11. 27 CFR 26.318 - Liquor bottles denied entry.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Liquor bottles denied... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE VIRGIN ISLANDS Requirements for Liquor Bottles § 26.318 Liquor bottles denied entry. Filled liquor bottles not conforming...

  12. 27 CFR 1.91 - Bottled distilled spirits.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottled distilled spirits..., NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled Spirits Warehouse Receipts § 1.91 Bottled distilled spirits. The provisions of...

  13. SCADA based radioactive sample bottle delivery system for fuel reprocessing project

    International Nuclear Information System (INIS)

    Radioactive samples of process streams need to be analyzed in centralized control lab for measuring concentration of heavy elements as well as activity at various stages of re-processing plants. The sample is taken from biologically shielded process cells remotely through sampling blisters in sample bottles. These are then transferred to control lab located about 50 meters using vacuum transfer system. The bottle movement is tracked from origin to destination in rich HMI SCADA system using Infra-red non contact type proximity sensors located along sampling line and these sensors are connected to PLC in a fail-safe mode. The sample bottle travels at a speed of 10 m/s under vacuum motive force and the detection time is of the order of 1 mS. The contact time Flow meters have been used to know the air flow in sampling line

  14. SCADA based radioactive sample bottle delivery system for fuel reprocessing project

    International Nuclear Information System (INIS)

    Radioactive samples of process streams need to be analyzed in centralized control lab for measuring concentration of heavy elements as well as activity at various stages of re-processing plants. The sample is taken from biologically shielded process cells remotely through sampling blisters in sample bottles. These are then transferred to control lab located about 50 meters using vacuum transfer system. The bottle movement is tracked from origin to destination in rich HMI SCADA system using Infra-red non contact type proximity sensors located along sampling line and these sensors are connected to PLC in a fail-safe mode. The sample bottle travels at a speed of 10 m/s under vacuum motive force and the detection time is of the order of 1 mS. The flow meters have been used to know the air flow in sampling line. The system has been designed, developed, tested and commissioned and in use for four years. (author)

  15. Analytical Model of an Asymmetric Sunspot with a Steady Plasma Flow in its Penumbra

    Science.gov (United States)

    Solov'ev, A. A.; Kirichek, E. A.

    2016-08-01

    A new exact analytical solution to the stationary problem of ideal magnetohydrodynamics is derived for an unipolar asymmetric sunspot immersed in a realistic solar atmosphere. The radial and vertical profiles of pressure, plasma density, and temperature in the visible layers of the sunspot are calculated. The reduction in plasma density in the magnetic funnel of the sunspot, corresponding to the Wilson depression, is also obtained. The magnetic structure of the sunspot is given analytically in a realistic way: a part of the magnetic flux of the sunspot approaches the surrounding photosphere at the outer edge of the penumbra. The magnetic field of the sunspot is not assumed to be axially symmetric. For the first time, the angular dependence of the physical variables in this model allows us to simulate not only a deviation from the circular shape of the sunspot, but also a fine filamentary structure of the sunspot penumbra. The Alfvén Mach number (the ratio of the plasma speed to the Alfvén speed) is zero at the center of the sunspot and rises slowly toward the periphery of the sunspot; this corresponds to the structure of the Evershed flow in the penumbra. The Evershed flow in our model is mainly concentrated in dark penumbral filaments, as is observed.

  16. Models, assumptions, and experimental tests of flows near boundaries in magnetized plasmas

    Science.gov (United States)

    Siddiqui, M. Umair; Thompson, Derek S.; Jackson, Cory D.; Kim, Justin F.; Hershkowitz, Noah; Scime, Earl E.

    2016-05-01

    We present the first measurements of ion flows in three dimensions (3Ds) using laser-induced fluorescence in the plasma boundary region. Measurements are performed upstream from a grounded stainless steel limiter plate at various angles ( ψ=16 ° to 80 ° ) to the background magnetic field in two argon helicon experiments (MARIA at the University of Wisconsin-Madison and HELIX at West Virginia University). The Chodura magnetic presheath model for collisionless plasmas [R. Chodura, Phys. Fluids 25, 1628 (1982)] is shown to be inaccurate for systems with sufficient ion-neutral collisions and ionization such as tokamak scrape off layers. A 3D ion fluid model that accounts for ionization and charge-exchange collisions is found to accurately describe the measured ion flows in regions where the ion flux tubes do not intersect the boundary. Ion acceleration in the E →×B → direction is observed within a few ion Larmor radii of the grounded plate for ψ=80 ° . We argue that fully 3D ion and neutral acceleration in the plasma boundary are uniquely caused by the long-range presheath electric fields, and that models that omit presheath effects under-predict observed wall erosion in tokamak divertors and Hall thruster channel walls.

  17. Shocks in unmagnetized plasma with a shear flow: Stability and magnetic field generation

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, M. E.; Bock, A.; Ynnerman, A. [Department of Science and Technology, Linköping University, SE-60174 Norrköping (Sweden); Ahmed, H.; Doria, D.; Sarri, G.; Borghesi, M. [Centre for Plasma Physics (CPP), Queen' s University Belfast, BT7 1NN (United Kingdom)

    2015-07-15

    A pair of curved shocks in a collisionless plasma is examined with a two-dimensional particle-in-cell simulation. The shocks are created by the collision of two electron-ion clouds at a speed that exceeds everywhere the threshold speed for shock formation. A variation of the collision speed along the initially planar collision boundary, which is comparable to the ion acoustic speed, yields a curvature of the shock that increases with time. The spatially varying Mach number of the shocks results in a variation of the downstream density in the direction along the shock boundary. This variation is eventually equilibrated by the thermal diffusion of ions. The pair of shocks is stable for tens of inverse ion plasma frequencies. The angle between the mean flow velocity vector of the inflowing upstream plasma and the shock's electrostatic field increases steadily during this time. The disalignment of both vectors gives rise to a rotational electron flow, which yields the growth of magnetic field patches that are coherent over tens of electron skin depths.

  18. Shocks in unmagnetized plasma with a shear flow: Stability and magnetic field generation

    International Nuclear Information System (INIS)

    A pair of curved shocks in a collisionless plasma is examined with a two-dimensional particle-in-cell simulation. The shocks are created by the collision of two electron-ion clouds at a speed that exceeds everywhere the threshold speed for shock formation. A variation of the collision speed along the initially planar collision boundary, which is comparable to the ion acoustic speed, yields a curvature of the shock that increases with time. The spatially varying Mach number of the shocks results in a variation of the downstream density in the direction along the shock boundary. This variation is eventually equilibrated by the thermal diffusion of ions. The pair of shocks is stable for tens of inverse ion plasma frequencies. The angle between the mean flow velocity vector of the inflowing upstream plasma and the shock's electrostatic field increases steadily during this time. The disalignment of both vectors gives rise to a rotational electron flow, which yields the growth of magnetic field patches that are coherent over tens of electron skin depths

  19. The Challenge of Incorporating Charged Dust in the Physics of Flowing Plasma Interactions

    Science.gov (United States)

    Jia, Y.; Russell, C. T.; Ma, Y.; Lai, H.; Jian, L.; Toth, G.

    2013-12-01

    The presence of two oppositely charged species with very different mass ratios leads to interesting physical processes and difficult numerical simulations. The reconnection problem is a classic example of this principle with a proton-electron mass ratio of 1836, but it is not the only example. Increasingly we are discovering situations in which heavy, electrically charged dust particles are major players in a plasma interaction. The mass of a 1mm dust particle is about 2000 proton masses and of a 10 mm dust particle about 2 million proton masses. One example comes from planetary magnetospheres. Charged dust pervades Enceladus' southern plume. The saturnian magnetospheric plasma flows through this dusty plume interacting with the charged dust and ionized plume gas. Multiple wakes are seen downstream. The flow is diverted in one direction. The field aligned-current systems are elsewhere. How can these two wake features be understood? Next we have an example from the solar wind. When asteroids collide in a disruptive collision, the solar wind strips the nano-scale charged dust from the debris forming a dusty plasma cloud that may be over 106km in extent and containing over 100 million kg of dust accelerated to the solar wind speed. How does this occur, especially as rapidly as it appears to happen? In this paper we illustrate a start on understanding these phenomena using multifluid MHD simulations but these simulations are only part of the answer to this complex problem that needs attention from a broader range of the community.

  20. Analytical Model of an Asymmetric Sunspot with a Steady Plasma Flow in its Penumbra

    Science.gov (United States)

    Solov'ev, A. A.; Kirichek, E. A.

    2016-06-01

    A new exact analytical solution to the stationary problem of ideal magnetohydrodynamics is derived for an unipolar asymmetric sunspot immersed in a realistic solar atmosphere. The radial and vertical profiles of pressure, plasma density, and temperature in the visible layers of the sunspot are calculated. The reduction in plasma density in the magnetic funnel of the sunspot, corresponding to the Wilson depression, is also obtained. The magnetic structure of the sunspot is given analytically in a realistic way: a part of the magnetic flux of the sunspot approaches the surrounding photosphere at the outer edge of the penumbra. The magnetic field of the sunspot is not assumed to be axially symmetric. For the first time, the angular dependence of the physical variables in this model allows us to simulate not only a deviation from the circular shape of the sunspot, but also a fine filamentary structure of the sunspot penumbra. The Alfvén Mach number (the ratio of the plasma speed to the Alfvén speed) is zero at the center of the sunspot and rises slowly toward the periphery of the sunspot; this corresponds to the structure of the Evershed flow in the penumbra. The Evershed flow in our model is mainly concentrated in dark penumbral filaments, as is observed.

  1. Shocks in unmagnetized plasma with a shear flow: Stability and magnetic field generation

    CERN Document Server

    Dieckmann, M E; Ahmed, H; Doria, D; Sarri, G; Ynnerman, A; Borghesi, M

    2015-01-01

    A pair of curved shocks in a collisionless plasma is examined with a two-dimensional particle-in-cell (PIC) simulation. The shocks are created by the collision of two electron-ion clouds at a speed that exceeds everywhere the threshold speed for shock formation. A variation of the collision speed along the initially planar collision boundary, which is comparable to the ion acoustic speed, yields a curvature of the shock that increases with time. The spatially varying Mach number of the shocks results in a variation of the downstream density in the direction along the shock boundary. This variation is eventually equilibrated by the thermal diffusion of ions. The pair of shocks is stable for tens of inverse ion plasma frequencies. The angle between the mean flow velocity vector of the inflowing upstream plasma and the shock's electrostatic field increases steadily during this time. The disalignment of both vectors gives rise to a rotational electron flow, which yields the growth of magnetic field patches that a...

  2. Particle-in-Cell Modeling of Magnetized Argon Plasma Flow Through Small Mechanical Apertures

    Energy Technology Data Exchange (ETDEWEB)

    Adam B. Sefkow and Samuel A. Cohen

    2009-04-09

    Motivated by observations of supersonic argon-ion flow generated by linear helicon-heated plasma devices, a three-dimensional particle-in-cell (PIC) code is used to study whether stationary electrostatic layers form near mechanical apertures intersecting the flow of magnetized plasma. By self-consistently evaluating the temporal evolution of the plasma in the vicinity of the aperture, the PIC simulations characterize the roles of the imposed aperture and applied magnetic field on ion acceleration. The PIC model includes ionization of a background neutral-argon population by thermal and superthermal electrons, the latter found upstream of the aperture. Near the aperture, a transition from a collisional to a collisionless regime occurs. Perturbations of density and potential, with mm wavelengths and consistent with ion acoustic waves, propagate axially. An ion acceleration region of length ~ 200-300 λD,e forms at the location of the aperture and is found to be an electrostatic double layer, with axially-separated regions of net positive and negative charge. Reducing the aperture diameter or increasing its length increases the double layer strength.

  3. Minimally-Invasive Gene Transfection by Chemical and Physical Interaction of Atmospheric Pressure Plasma Flow

    Science.gov (United States)

    Kaneko, Toshiro

    2014-10-01

    Non-equilibrium atmospheric pressure plasma irradiated to the living-cell is investigated for medical applications such as gene transfection, which is expected to play an important role in molecular biology, gene therapy, and creation of induced pluripotent stem (iPS) cells. However, the conventional gene transfection using the plasma has some problems that the cell viability is low and the genes cannot be transferred into some specific lipid cells, which is attributed to the unknown mechanism of the gene transfection using the plasma. Therefore, the time-controlled atmospheric pressure plasma flow is generated and irradiated to the living-cell suspended solution for clarifying the transfection mechanism toward developing highly-efficient and minimally- invasive gene transfection system. In this experiment, fluorescent dye YOYO-1 is used as the simulated gene and LIVE/DEAD Stain is simultaneously used for cell viability assay. By the fluorescence image, the transfection efficiency is calculated as the ratio of the number of transferred and surviving cells to total cell count. It is clarified that the transfection efficiency is significantly increased by the short-time (plasma irradiation, and the high transfection efficiency of 53% is realized together with the high cell viability (>90%). This result indicates that the physical effects such as the electric field caused by the charged particles arriving at the surface of the cell membrane, and chemical effects associated with plasma-activated products in solution act synergistically to enhance the cell-membrane transport with low-damage. This work was supported by JSPS KAKENHI Grant Number 24108004.

  4. Spectro-polarimetrc optical systems for imaging plasma internal fields, structures and flows

    International Nuclear Information System (INIS)

    Spectro-polarimetric imaging systems have opened new and better ways to study the spatio-temporal behaviour of plasma properties including current distribution, pedestal fields and the velocity distribution function of radiating species from the plasma edge to the core. Using spatial-heterodyne polarimetric techniques, these coherence-imaging (CI) systems have been deployed for motional Stark effect (MSE) imaging and charge-exchange Doppler imaging (CXRS) on KSTAR and ASDEX-Upgrade, and for passive Doppler spectroscopy of the plasma edge on DIII-D and MAST. They have also been used for Doppler imaging of low-temperature argon discharges on the linear mirror device MAGPIE at the ANU, including synchronous Doppler imaging of flow vortices associated with low frequency instabilities. We describe the diagnostic technologies, discuss the results and comparisons with simple models, and consider new applications and future developments. A shorter version of this contribution is due to be published in PoS at: 1st EPS conference on Plasma Diagnostics

  5. A new concept of high flow rate non-thermal plasma reactor for air treatment

    Energy Technology Data Exchange (ETDEWEB)

    Goujard, V.; Tatibouet, J.M. [Univ. de Poitiers, Poitiers (France). Centre national de la recherche scientifique, Laboratoire de Catalyse en Chimie Organique

    2010-07-01

    Although several non-thermal plasma reactors have been tested for air treatment at the laboratory scale, up-scaling to pilot or industrial scale remains a challenge because several parameters must be considered, such as hydrodynamic behaviour, maximum voltage in an industrial environment, and maintenance of the system. This paper presented a newly developed reactor which consists to a DBD plasma generated on individual supports that could be directly inserted in gas pipes where air flow must be treated. Elimination of 40 percent of 15 ppm of propene was obtained with a energy density as low as 10 J/L. The propene conversion increased when a manganese oxide based catalyst was used because the ozone produced by the plasma was used as an as an oxidant. A simple model of the plasma-catalyst reactor behaviour showed that more than 90 percent of propene conversion can be expected for an input energy density of 10 J/L and residual ozone concentration less than 100 ppb.

  6. Surface Decontamination of Chemical Agent Surrogates Using an Atmospheric Pressure Air Flow Plasma Jet

    International Nuclear Information System (INIS)

    An atmospheric pressure dielectric barrier discharge (DBD) plasma jet generator using air flow as the feedstock gas was applied to decontaminate the chemical agent surrogates on the surface of aluminum, stainless steel or iron plate painted with alkyd or PVC. The experimental results of material decontamination show that the residual chemical agent on the material is lower than the permissible value of the National Military Standard of China. In order to test the corrosion effect of the plasma jet on different material surfaces in the decontamination process, corrosion tests for the materials of polymethyl methacrylate, neoprene, polyvinyl chloride (PVC), polyethylene (PE), phenolic resin, iron plate painted with alkyd, stainless steel, aluminum, etc. were carried out, and relevant parameters were examined, including etiolation index, chromatism, loss of gloss, corrosion form, etc. The results show that the plasma jet is slightly corrosive for part of the materials, but their performances are not affected. A portable calculator, computer display, mainboard, circuit board of radiogram, and a hygrometer could work normally after being treated by the plasma jet

  7. Research on bottom detection in Intelligent Empty Bottle Inspection System

    OpenAIRE

    Bin Huang; Sile Ma; Yufeng Lv; Hualong Zhang; Chunming Liu; Huajie Wang

    2013-01-01

    Intelligent empty bottle inspection system is an important inspection equipment of empty bottle before filling beer, and it is a blend of machine vision, precision machine and real-time control. They need to cooperate perfectly to achieve the desired effect. In the design of the empty bottle inspection system, one of the key technologies is the bottle bottom detection which affects the speed and accuracy of the system. It includes positioning and defect recognition of bottle bottom. For the...

  8. Two-dimensional electron flow in pulsed power transmission lines and plasma opening switches

    International Nuclear Information System (INIS)

    The operation of magnetically insulated transmission lines (MITL) and the interruption of current in a plasma opening switch (POS) are determined by the physics of the electrons emitted by the cathode surface. A mathematical model describes the self-consistent two-dimensional flow of an electron fluid. A finite element code, FERUS, has been developed to solve the two equations which describe Poisson's and Ampere's law in two dimensions. The solutions from this code are obtained for parameters where the electron orbits are considerably modified by the self-magnetic field of the current. Next, the self-insulated electron flow in a MITL with a step change in cross-section is studied using a conventional two-dimensional fully electromagnetic particle-in-cell code, MASK. The equations governing two-dimensional quasi-static electron flow are solved numerically by a third technique which is suitable for predicting current interruption in a POS. The object of the study is to determine the critical load impedance, ZCL, required for current interruption for a given applied voltage, cathode voltage and plasma length. (author). 9 refs, 5 figs

  9. Dynamics of the gas flow turbulent front in atmospheric pressure plasma jets

    Science.gov (United States)

    Pei, X.; Ghasemi, M.; Xu, H.; Hasnain, Q.; Wu, S.; Tu, Y.; Lu, X.

    2016-06-01

    In this paper, dynamic characterizations of the turbulent flow field in atmospheric pressure plasma jets (APPJs) are investigated by focusing on the effect of different APPJ parameters, such as gas flow rate, applied voltage, pulse repetition frequency, and time duration of the pulse. We utilize Schlieren photography and photomultiplier tubes (PMT) as a signal triggering of an intensified charge coupled device (ICCD) and also a high speed camera to examine the formation of the turbulent front and its dynamics. The results reveal that the turbulent front will appear earlier and closer to the tube nozzle by increasing the gas flow rate or the applied voltage amplitude. However, the pulse time duration and repetition frequency cannot change the dynamics and formation of the turbulent front. Further investigation shows that every pulse can excite one turbulent front which is created in a specific position in a laminar region and propagates downstream. It seems that the dominating mechanisms responsible for the formation of turbulent fronts in plasma jets might not be ion momentum transfer.

  10. Kinetic description of wave induced plasma flow in the radio frequency domain

    CERN Document Server

    Van Eester, Dirk; Kazakov, Yevgen

    2014-01-01

    A model for ICRH induced flows in the presence of a strong magnetic field is presented. These flows are the finite temperature counterpart of flows existing in cold plasmas described e.g. in [D. Van Eester et al., Plasma Phys. Control. Fusion 55 (2013) 025002] and thus do not rely on the waves being damped. The kinetic corrections offer insight in what happens at cyclotron resonances. Authors commonly either rely on the confining magnetic field $\\vec{B}_o$-field to be strong, or the electric field $\\vec{E}$-field to be rapidly varying but are not accounting for both when writing down the solution of the equation of motion on the slow time scale. In this paper, the equation of motion is solved for constant $B_o$ to keep the discussion as simple as possible. The simultaneous presence of $\\vec{B}_o$ and the $\\vec{E}$-field inhomogeneity causes drifts perpendicular to the $\\vec{B}_o$ and to other slow time scale accelerations, the Ponderomotive acceleration being one of them. Because of the first and having tokam...

  11. Velocity Statistics in Holographic Fluids: Magnetized Quark-Gluon Plasma and Superfluid Flow

    CERN Document Server

    Areán, Daniel; Patiño, Leonardo; Villasante, Mario

    2016-01-01

    We study the velocity statistics distribution of an external heavy particle in holographic fluids. We argue that when the dual supergravity background has a finite temperature horizon the velocity statistics goes generically as $1/v$, compatible with the jet-quenching intuition from the quark-gluon plasma. A careful analysis of the behavior of the classical string whose apparent world sheet horizon deviates from the background horizon reveals that other regimes are possible. We numerically discuss two cases: the magnetized quark-gluon plasma and a model of superfluid flow. We explore a range of parameters in these top-down supergravity solutions including, respectively, the magnetic field and the superfluid velocity. We determine that the velocity statistics goes largely as $1/v$, however, as we leave the non-relativistic regime we observe some deviations.

  12. Measurements of the asymmetric dynamic sheath around a pulse biased sphere immersed in flowing metal plasma

    International Nuclear Information System (INIS)

    A long-probe technique was utilized to record the expansion and retreat of the dynamic sheath around a spherical substrate immersed in pulsed cathode arc metal plasma. Positively biased, long cylindrical probes were placed on the side and downstream of a negatively pulsed biased stainless steel sphere of 1 in. (25.4 mm) diameter. The amplitude and width of the negative high voltage pulses (HVPs) were 2 kV, 5 kV, 10 kV, and 2 μs, 4 μs, 10 μs, respectively. The variation of the probe (electron) current during the HVP is a direct measure for the sheath expansion and retreat. Maximum sheath sizes were determined for the different parameters of the HVP. The expected rarefaction zone behind the biased sphere (wake) due to the fast plasma flow was clearly established and quantified.

  13. Measurements of the asymmetric, dynamic sheath around a pulse biased sphere immersed in flowing metal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre; Wu, Hongchen; Anders, Andre

    2008-06-13

    A long-probe technique was utilized to record the expansion and retreat of the dynamic sheath around a spherical substrate immersed in pulsed cathode arc metal plasma. Positively biased, long cylindrical probes were placed on the side and downstream of a negatively pulsed biased stainless steel sphere of 1" (25.4 mm) diameter. The amplitude and width of the negative high voltage pulses (HVP) were 2 kV, 5 kV, 10 kV, and 2 mu s, 4 mu s, 10 mu s, respectively. The variation of the probe (electron) current during the HVP is a direct measure for the sheath expansion and retreat. Maximum sheath sizes were determined for the different parameters of the HVP. The expected rarefaction zone behind the biased sphere (wake) due to the fast plasma flow was clearly established and quantified.

  14. Growth and properties of amorphous silicon films grown using pulsed-flow reactive plasma beam epitaxy

    Science.gov (United States)

    Dalal, Vikram L.; Knox, Ralph; Kandalaft, Nabeeh; Baldwin, Greg

    1991-01-01

    The growth and properties of a-Si:H films grown using a novel deposition technique, reactive plasma beam epitaxy, are discussed. In this technique, a remote H plasma produced in a microwave-ECR reactor is used to grow a-Si:H films at low pressures. The H ions react with SiH4 introduced near the substrate to produce the film. The flow of SiH4 is pulsed on or off, thereby achieving in-situ annealing of the film during growth by H ions and radicals. The films produced by this technique appear to have good electronic quality, and are more stable than the standard glow discharge films.

  15. Dynamics of flows, fluctuations, and global instability under electrode biasing in a linear plasma device

    Science.gov (United States)

    Desjardins, T. R.; Gilmore, M.

    2016-05-01

    Grid biasing is utilized in a large-scale helicon plasma to modify an existing instability. It is shown both experimentally and with a linear stability analysis to be a hybrid drift-Kelvin-Helmholtz mode. At low magnetic field strengths, coherent fluctuations are present, while at high magnetic field strengths, the plasma is broad-band turbulent. Grid biasing is used to drive the once-coherent fluctuations to a broad-band turbulent state, as well as to suppress them. There is a corresponding change in the flow shear. When a high positive bias (10Te) is applied to the grid electrode, a large-scale ( n ˜/n ≈50 % ) is excited. This mode has been identified as the potential relaxation instability.

  16. Modeling of energy transfer between two crossing smoothed laser beams in a plasma with flow profile

    Science.gov (United States)

    Colaitis, A.; Hüller, S.; Tikhonchuk, V. T.; Pesme, D.; Duchateau, G.; Porzio, A.

    2016-05-01

    We study the crossed beam energy transfer (CBET) between laser fields generated by optical smoothing methods. The energy transfer, as well as the angular distribution of the outgoing light fields are investigated for two incident smoothed laser beams in a plasma with a flow gradient, allowing for resonant transfer close to the sonic point. Simulations with the code HARMONY based on time-dependent paraxial light propagation are compared to simulations using a new approach based on paraxial complex geometrical optics (PCGO). Both approaches show good agreement for the average energy transfer past a short transient period, which is a promising result for the use of the PCGO method as a module within a hydrodynamics code to efficiently compute CBET in mm-scale plasma configurations. Statistical aspects related to role of laser speckles in CBET are considered via an ensemble of different phase plate realizations.

  17. Relaxation of a magnetized electron-positron-ion plasma with flows

    International Nuclear Information System (INIS)

    It is shown that possible relaxed magnetic field configurations of a magnetized electron-positron-ion (e-p-i) plasma with flows can be described by a triple curl Beltrami (TCB) equation, which is equivalent to the superposition of three different Beltrami fields. The TCB equation admits three relaxed structures when the linear and nonlinear inertial forces of all three plasma species involved are taken into account. One of the structures represents the system size while the remaining two could be of the order of electron skin depth. -- Highlights: → Relaxed magnetic field configurations satisfy triple curl Beltrami equation. → Relaxed state is characterized by three scale parameters. → Inertial effects play an important role to create Beltrami fields.

  18. Control of dispersed-phase temperature in plasma flows by the spectral-brightness pyrometry method

    Science.gov (United States)

    Dolmatov, A. V.; Gulyaev, I. P.; Gulyaev, P. Yu; Iordan, V. I.

    2016-02-01

    In the present work, we propose a new method for measuring the distribution of temperature in the ensembles of condensed-phase particles in plasma spray flows. Interrelation between the spectral temperature of the particles and the distribution of camera brightness signal is revealed. The established inter-relation enables an in-situ calibration of measuring instruments using the objects under study. The spectral-brightness pyrometry method was approbated on a Plazer plasma-arc wire spraying facility at the Paton Institute of Electrical Welding (Ukrainian Academy of Sciences, Kiev) and on the Thermoplasma 50-1 powder spraying facility at the Institute of Theoretical and Applied Mechanics (Russian Academy of Sciences, Siberian Branch, Novosibirsk). The work was supported by the Russian Foundation for Basic Research (Grants Nos. 14-08-90428 and 15-48-00100).

  19. A novel plasma heater for auto-ignition studies of turbulent non-premixed flows

    Science.gov (United States)

    Eitel, Felix; Pareja, Jhon; Geyer, Dirk; Johchi, Ayane; Michel, Florian; Elsäßer, Wolfgang; Dreizler, Andreas

    2015-10-01

    In this paper, the development and characterization of a novel test rig for auto-ignition (AI) studies of a fuel jet propagating into a hot turbulent co-flow is reported. The test rig, based on microwave plasma heating, is capable of achieving co-flow temperatures up to 1300 K and velocities up to 40 {ms}^{-1}. Important boundary conditions at nozzle exit such as temperature, species, and velocity field were determined to prove the capabilities and limitations of the test rig. Liftoff height (LOH) measurements of {CH}_4, {C}_2{H}_4, and {CH}4/{H}2 jets, propagating into a turbulent heated air co-flow, were taken using chemiluminescence imaging. Effects of the temperature and Reynolds number ( Re) of co-flow and jet were also studied. Results showed that the flame stabilization mechanism is supported substantially by AI rather than pure flame propagation. While the co-flow temperature dominates the AI process, the Re and temperature of the jet just have a small impact on the LOH.

  20. Effect of Plasma Power and Flow Rate of Silane Gas on Diameter of Silicon Nano wires Grown by Plasma Enhanced Chemical Vapor Deposition

    International Nuclear Information System (INIS)

    Silicon nano wires (SiNWs) have been synthesized by plasma enhanced chemical vapor deposition (PECVD) at different power for generation of plasma and different flow rate of silane gas. Silane (10 % SiH4 in Ar) gas with flow rate ranging between 6-15 standard cubic centimeter per minute (sccm) were employed as the source and gold colloid as the catalyst. A p-type Si (100) wafer was used as substrate in this experiment and the substrates temperature was 370 degree Celsius.The plasma power range was 12-17 watts. The grown silicon nano wires were analyzed using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX). FESEM results show that some silicon nano wires are cone like and some of them are cylindrical. The EDX result revealed that the existence of silicon and oxygen elements in the nano wires. The silicon nano wires obtained have different diameters and lengths and the SiNWs consist of silicon core which are surrounded by oxide sheath. It has been found that the plasma power and flow rate of the silane gas influence the size of silicon narrowness growth by PECVD. The diameter of wires decreased from 140 nm to 80 nm averagely when plasma power was increased from 12 to 17 watts. The diameter also increased about 90 nm to 150 nm when the flow rate of silane gas is increased from 6 to 15 sccm. (author)

  1. Hydrogen production from methane using an RF plasma source in total nonambipolar flow

    International Nuclear Information System (INIS)

    A radio-frequency (RF) helicon plasma reaction chamber (HPRC) is developed and used to decompose methane gas into high-purity hydrogen gas and solid carbon in the form of graphite. A single-turn (m = 0) helicon antenna, operated at 13.56 MHz, and a 100 G dipole magnetic field are used to excite a helicon mode in a nonthermal plasma, creating plasma densities exceeding 1013 cm−3 using 8–20 SCCM methane gas at up to 1300 W of RF power. The HPRC device takes advantage of a uniform large amplitude electron sheath across the exit aperture. At this aperture, all of the incident electron flux from the plasma is extracted and all ions are reflected back into the source. In this way, only neutrals and electrons are allowed out of the reaction chamber, enhancing the breakdown of methane into deposited carbon and hydrogen gas that escapes. A methane decomposition percentage of 99.99 ± 0.06% is demonstrated using 1300 W of RF power and a methane gas flow rate of 8 SCCM. A total nonambipolar flow of particles maximizes the recirculation of ions, and leads to the very high degree of molecular decomposition achieved in this proof-of-concept device. The HPRC in its present proof-of-concept form requires 37× more energy per kg of H2 produced, compared with steam-methane reformation, though this energy comparison does not include the energy required to sequester the emitted CO2 during the steam–methane reformation cycle.

  2. GLOBEC NEP Rosette Bottle Data (2002)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — GLOBEC (GLOBal Ocean ECosystems Dynamics) NEP (Northeast Pacific) Rosette Bottle Data from New Horizon Cruise (NH0207: 1-19 August 2002). Notes: Physical data...

  3. Optical diagnostics of a low power—low gas flow rates atmospheric-pressure argon plasma created by a microwave plasma torch

    Science.gov (United States)

    Wang, Chuji; Srivastava, Nimisha; Scherrer, Susan; Jang, Ping-Rey; Dibble, Theodore S.; Duan, Yixiang

    2009-05-01

    We employ a suite of optical techniques, namely, visual imaging, optical emission spectroscopy and cavity ringdown spectroscopy (CRDS), to characterize a low power, low gas flow rates, atmospheric-pressure argon microwave induced plasma. The plasma is created by a microwave plasma torch, which is excited by a 2.45 GHz microwave with powers ranging from 60 to 120 W. A series of plasma images captured in a time-resolution range of as fine as 10 µs shows that the converging point is actually a time-averaged visual effect and the converging point does not exist when the plasma is visualized under high time resolution, e.g. Tv), the rotational temperature (Tr) and the gas temperature (Tg) at different locations along the axis of the plasma column are all determined to be in the range 1800-2200 K. Thermal equilibrium properties of the plasma are discussed. OH radical concentrations along the plasma column axis are measured by CRDS and the concentrations are in the range 1.6 × 1013-3.0 × 1014 cm-3 with the highest density at the tail of the plasma column. The upper limit of electron density ne is estimated to be 5.0 × 1014 cm-3 from the Lorentzian component of the broadened lineshape obtained by ringdown spectral scans of the rovibrational line S21 of the OH A-X (0-0) band.

  4. Silicon oxide permeation barrier coating of PET bottles and foils

    Science.gov (United States)

    Steves, Simon; Deilmann, Michael; Awakowicz, Peter

    2009-10-01

    Modern packaging materials such as polyethylene terephthalate (PET) have displaced established materials in many areas of food and beverage packaging. Plastic packing materials offer are various advantages concerning production and handling. PET bottles for instance are non-breakable and lightweight compared to glass and metal containers. However, PET offers poor barrier properties against gas permeation. Therefore, the shelf live of packaged food is reduced. Permeation of gases can be reduced by depositing transparent plasma polymerized silicon oxide (SiOx) barrier coatings. A microwave (2.45 GHz) driven low pressure plasma reactor is developed based on a modified Plasmaline antenna to treat PET foils or bottles. To increase the barrier properties of the coatings furthermore a RF substrate bias (13.56 MHz) is applied. The composition of the coatings is analyzed by means of Fourier transform infrared (FTIR) spectroscopy regarding carbon and hydrogen content. Influence of gas phase composition and substrate bias on chemical composition of the coatings is discussed. A strong relation between barrier properties and film composition is found: good oxygen barriers are observed as carbon content is reduced and films become quartz-like. Regarding oxygen permeation a barrier improvement factor (BIF) of 70 is achieved.

  5. Blob/hole formation and zonal-flow generation in the edge plasma of the JET tokamak

    DEFF Research Database (Denmark)

    Xu, G.S.; Naulin, Volker; Fundamenski, W.;

    2009-01-01

    The first experimental evidence showing the connection between blob/hole formation and zonal-flow generation was obtained in the edge plasma of the JET tokamak. Holes as well as blobs are observed to be born in the edge shear layer, where zonal-flows shear off meso-scale coherent structures, lead...

  6. Geochemical atlas of European groundwater : bottled water

    OpenAIRE

    Reimann, Clemens; Birke, Manfred; Demetriades, Alecos; Johnson, Christopher

    2012-01-01

    Analysis of natural bottled mineral water (usually derived from untreated ground water) can provide a first impression of ground water chemistry at the European scale. For this study, 1785 bottled water samples were purchased from supermarkets, representing 1247 wells/springs/boreholes at 884 locations. These were analysed for 72 parameters by a variety of methods. A very strict quality control programme was followed to ensure results of high standard that are presented as a geochemical atlas...

  7. Steam Plasma Flows Generated in Gerdien Arc: Environment for Energy Gas Production from Organics and for Surface Coatings

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan

    2011-01-01

    Roč. 6, č. 5 (2011), s. 792-801. ISSN 1880-5558. [Seventh International Conference on Flow Dynamics. Sendai, 01.11.2010-03.11.2010] R&D Projects: GA ČR GAP205/11/2070 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal Plasma * Dc Arc Plasma Torch * Gerdien Arc * Plasma Gasification Subject RIV: BL - Plasma and Gas Discharge Physics http://www.jstage.jst.go.jp/article/jfst/6/5/792/_pdf

  8. Characteristics of the steady-state flow of a two-temperature argonarc plasma in a channel

    International Nuclear Information System (INIS)

    The authors examine the effects of laminar and turbulent flow on the characteristics of two-temperature argon plasma in the steady state part of an electric arc in a cylindrical channel; they examine existing formulas for the plasma properties and have selected for use here those that agree best with the experiment. This work has been done because design of high-temperature gas heaters with given characteristics is hindered by the lack of applicable models closely adapted to real conditions, this applying particularly to electric-arc plasma sources that produce thermally nonequilibrium plasma

  9. Comparison of optical emission spectrums of cold flowing discharge and the post-discharge plasmas of air at low pressure

    OpenAIRE

    İlik, Erkan; AKAN, Tamer; Durmuş, Çağrı; Tanışlı, Murat; Şahin, Neslihan; Mertadam, Sercan

    2015-01-01

    The main differences between cold flowing discharge and the post-discharge plasmas of any gas are intended with the help of new designed plasma generation reactor which Works at low pressure. The up and the middle flanges which made of stainless steel are served as ring electrodes on the plasma generation reactor at low pressure and low temperature. The discharge and the post-discharge plasmas of air are created by means of a d.c. power supply. The reactor both generating post – discharge pla...

  10. Conservation laws for steady flow and solitons in a multifluid plasma revisited

    International Nuclear Information System (INIS)

    The conservation laws used in constructing the governing equations for planar solitons in multifluid plasmas are revisited. In particular, the concept of generalized vorticity facilitates the derivation of some general ''Bernoulli theorems,'' which reduce, in specific instances, to conservation laws previously deduced by other means. These theorems clarify the underlying physical principles that give rise to the conserved quantities. As an example of the usefulness of the techniques, even for relatively simple flows and progressive waves, the equations governing stationary nonlinear whistler waves propagating parallel to an ambient magnetic field are derived using generalized vorticity concepts

  11. Diffusive processes in the cross-field flow of intense plasma beams

    International Nuclear Information System (INIS)

    We consider magnetic field diffusion in the presence of strongly magnetized electrons (ω/sub ce//tau//sub co/ > 1) as a mechanism for the rapid field penetration observed in cross-field flows of high-β plasma beams. The diffusion has been investigated in several cases which are amenable to analytic solution. The flux penetration times are found to be insensitive to the particular configuration. Comparison with two experiments is made. Agreement within the limits of the experiments is found. Both require an anomalous collision rate which is consistent with observed fluctuations in one case but apparently not the other. 17 refs., 1 fig

  12. Ras oncogene expression and DNA content in plasma cell dyscrasias: a flow cytofluorimetric study.

    OpenAIRE

    Danova, M. (M); Riccardi, A.; Ucci, G.; Luoni, R.; Giordano, M.; G Mazzini

    1990-01-01

    Using bivariate flow cytofluorometry, we have determined the nuclear DNA distribution and the expression of the p21 protein (coded by the Ha-ras oncogene) in the bone marrow (BM) cells of five solid tumour patients having histologically normal BM and in those of 57 patients with plasma cell dyscrasia (28 with monoclonal gammopathies of undertermined significance, MGUS, and 29 with multiple myeloma, MM). All normal and MGUS and 21/29 (72.4%) MM BM had diploid modal DNA content and 8/29 (27.6%)...

  13. Magnetic Field Induced Shear Flow in a Strongly Coupled Complex Plasma

    CERN Document Server

    Bandyopadhyay, P; Jiang, K; Morfill, G

    2016-01-01

    We address an experimental observation of shear flow of micron sized dust particles in a strongly coupled complex plasma in presence of a homogeneous magnetic field. Two concentric Aluminum rings of different size are placed on the lower electrode of a radio frequency (rf) parallel plate discharge. The modified local sheath electric field is pointing outward/inward close to the inner/outher ring, respectively. The microparticles, confined by the rings and subject to an ion wind that driven by the local sheath electric field and deflected by an externally applied magnetic field, start flowing in azimuthal direction. Depending upon the rf amplitudes on the electrodes, the dust layers show rotation in opposite direction at the edges of the ring-shaped cloud resulting a strong shear in its center. MD simulations shows a good agreement with the experimental results.

  14. Metamorphosis of plasma turbulence-shear-flow dynamics through a transcritical bifurcation

    International Nuclear Information System (INIS)

    The structural properties of an economical model for a confined plasma turbulence governor are investigated through bifurcation and stability analyses. A close relationship is demonstrated between the underlying bifurcation framework of the model and typical behavior associated with low- to high-confinement transitions such as shear-flow stabilization of turbulence and oscillatory collective action. In particular, the analysis evinces two types of discontinuous transition that are qualitatively distinct. One involves classical hysteresis, governed by viscous dissipation. The other is intrinsically oscillatory and nonhysteretic, and thus provides a model for the so-called dithering transitions that are frequently observed. This metamorphosis, or transformation, of the system dynamics is an important late side-effect of symmetry breaking, which manifests as an unusual nonsymmetric transcritical bifurcation induced by a significant shear-flow drive

  15. Metamorphosis of plasma turbulence-shear flow dynamics through a transcritical bifurcation

    CERN Document Server

    Ball, R; Sugama, H

    2002-01-01

    The structural properties of an economical model for a confined plasma turbulence governor are investigated through bifurcation and stability analyses. A close relationship is demonstrated between the underlying bifurcation framework of the model and typical behavior associated with low- to high-confinement transitions such as shear flow stabilization of turbulence and oscillatory collective action. In particular, the analysis evinces two types of discontinuous transition that are qualitatively distinct. One involves classical hysteresis, governed by viscous dissipation. The other is intrinsically oscillatory and non-hysteretic, and thus provides a model for the so-called dithering transitions that are frequently observed. This metamorphosis, or transformation, of the system dynamics is an important late side-effect of symmetry-breaking, which manifests as an unusual non-symmetric transcritical bifurcation induced by a significant shear flow drive.

  16. All-vanadium redox flow batteries with graphite felt electrodes treated by atmospheric pressure plasma jets

    Science.gov (United States)

    Chen, Jian-Zhang; Liao, Wei-Yang; Hsieh, Wen-Yen; Hsu, Cheng-Che; Chen, Yong-Song

    2015-01-01

    Graphite felts modified with atmospheric pressure plasma jets (APPJs) are applied as electrodes in an all-vanadium redox flow battery (VRFB). APPJ flow penetrates deeply into the graphite felt, improving significantly the wettability of the graphite felt inside out and, thereby, enhancing graphite fiber-electrolyte contact during battery operation. The energy efficiency of a VRFB was improved from 62% (untreated) to 76% (APPJ-treated with the scan mode) at a current density of 80 mA cm-2, an improvement of 22%. The efficiency improvement is attributed to the oxygen-containing groups and nitrogen doping introduced by N2 APPJs on the fiber surfaces of graphite felt, both of which enhance electrochemical reactivity.

  17. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    CERN Document Server

    Brust, M; Thiebaud, M; Flormann, D; Verdier, C; Kaestner, L; Laschke, M W; Selmi, H; Benyoussef, A; Podgorski, T; Coupier, G; Misbah, C; Wagner, C

    2014-01-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These pers...

  18. Dynamic effects on the stretching of the magnetic field by a plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, Manuel [Departamento de Analisis Matematico, Universidad de Valladolid, 47005 Valladolid (Spain)

    2003-08-22

    A key mechanism in the growth of magnetic energy in kinematic dynamos is the stretching of the magnetic field vector by making it point in an unstable direction of the strain matrix. Our objective is to study whether this feature may be maintained in an ideal plasma when also considering the back reaction of the magnetic field upon the flow through the Lorentz force. Several effects occur: in addition to the nonlocal ones exerted by the total pressure, a complex geometry of magnetic field lines decreases the rate of growth of magnetic energy, rotation of the flow enhances it and above all the rate of growth decreases with minus the square of the eigenvalue associated with the magnetic field direction. Thus local dynamics tend to rapidly quench the stretching of the field.

  19. Links between magnetic fields and plasma flows in a coronal hole

    CERN Document Server

    Wiegelmann, T; Marsch, E

    2008-01-01

    We compare the small-scale features visible in the Ne viii Doppler-shift map of an equatorial coronal hole (CH) as observed by SUMER with the small-scale structures of the magnetic field as constructed from a simultaneous photospheric magnetogram by a potential magnetic-field extrapolation. The combined data set is analysed with respect to the small-scale flows of coronal matter, which means that the Ne viii Doppler-shift used as tracer of the plasma flow is investigated in close connection with the ambient magnetic field. Some small closed-field regions in this largely open CH are also found in the coronal volume considered. The Doppler-shift patterns are found to be clearly linked with the field topology.

  20. Contamination of bottled waters with antimony leaching from polyethylene terephthalate (PET) increases upon storage.

    Science.gov (United States)

    Shotyk, William; Krachler, Michael

    2007-03-01

    Antimony concentrations were determined in 132 brands of bottled water from 28 countries. Two of the brands were at or above the maximum allowable Sb concentration for drinking water in Japan (2 microg/L). Elevated concentrations of Sb in bottled waters are due mainly to the Sb2O3 used as the catalyst in the manufacture of polyethylene terephthalate (PET(E)). The leaching of Sb from PET(E) bottles shows variable reactivity. In 14 brands of bottled water from Canada, Sb concentrations increased on average 19% during 6 months storage at room temperature, but 48 brands of water from 11 European countries increased on average 90% under identical conditions. A mineral water from France in PET(E), purchased in Germany, yielded 725 ng/L when first tested, but 1510 ng/L when it was stored for 6 months at room temperature; the same brand of water, purchased in Hong Kong, yielded 1990 ng/L Sb. Pristine groundwater containing 1.7+/-0.4 ng/L Sb (n = 6) yielded 26.6+/-2.3 ng/L Sb (n = 3) after storage in PET(E) bottles from Canada for 6 months versus 281+/-38 ng/L Sb (n = 3) in PET(E) bottles from Germany. Tap water bottled commercially in PET(E) in December 2005 contained 450+/-56 ng/L Sb (n = 3) versus 70.3+/-0.3 ng/L Sb (n = 3) when sampled from a household faucet in the same village (Bammental, Germany), and 25.7+/-1.5 ng/L Sb (n = 3) from a local artesian flow. PMID:17396641

  1. Proton entry into the near-lunar plasma wake for magnetic field aligned flow

    CERN Document Server

    Dhanya, M B; Futaana, Y; Fatemi, S; Holmström, M; Barabash, S; Wieser, M; Wurz, P; Alok, A; Thampi, R S

    2016-01-01

    We report the first observation of protons in the near (100--200 km from surface) and deeper (near anti-subsolar point) lunar plasma wake when the interplanetary magnetic field (IMF) and solar wind velocity ($v_{sw}$) are parallel (aligned flow, angle between IMF and ($v_{sw} \\le 10^\\circ$). More than 98% of the observations during aligned flow condition showed the presence of protons in the wake. These observations are obtained by the SWIM sensor of the SARA experiment on Chandrayaan-1. The observation cannot be explained by the conventional fluid models for aligned flow. Back-tracing of the observed protons suggests that their source is the solar wind. The larger gyro-radii of the wake protons compared to that of solar wind suggest that they were part of the tail of the solar wind velocity distribution function. Such protons could enter the wake due to their large gyro-radii even when the flow is aligned to IMF. However, the wake boundary electric field may also play a role in the entry of the protons in to...

  2. Novel Gas Barrier SiOC Coating to PET Bottles through a Hot Wire CVD Method

    Directory of Open Access Journals (Sweden)

    Masaki Nakaya

    2016-01-01

    Full Text Available In an attempt to enhance the gas barrier enhancement of plastic containers such as poly(ethylene terephthalate bottles, a novel method was found using a hot wire CVD technique, where tantalum wire is heated and exposed to a gas flow of vinyl silane. The resultant SiOC thin film was confirmed to characteristically contain Si-Si bonds in its surface and demonstrate a remarkably and highly practical decrease of the permeation of various gas through poly(ethylene terephthalate bottles.

  3. Plasma flow switch characterization for the Los Alamos Foil Implosion Project

    International Nuclear Information System (INIS)

    The next system design under consideration for the Los Alamos Foil Implosion Project is projected to deliver tens of mega-amperes of electrical current produced by high-explosive driven flux compression generators on a time scale of about one microsecond to a load foil. The use of such generators, with time scales of order several tenths of a millisecond, leads to considerable pulse shaping problems. Previously it was noted that a commutating switch might serve as an efficient alternative to a closing switch in transferring current from a coaxial transmission line to a cylindrically imploding load. Research at the Air Force Weapons Laboratory (AFWL) has met with considerable success in efficiently transferring currents of order 10 MA to an imploding liner using the plasma flow switch concept (PFS). Besides efficiently transferring current, the plasma flow switch protects the load region from high voltages generated by an opening switch until the current is present to provide magnetic insulation. For these reasons, a PFS is being investigated as the final pulse shaping step in the design. A series of capacitor bank experiments is also being fielded to help investigate physics issues and to benchmark the codes

  4. The electron forewake: Shadowing and drift-energization as flowing magnetized plasma encounters an obstacle

    Energy Technology Data Exchange (ETDEWEB)

    Haakonsen, Christian Bernt, E-mail: chaako@mit.edu; Hutchinson, Ian H., E-mail: ihutch@mit.edu [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-10-15

    Flow of magnetized plasma past an obstacle creates a traditional wake, but also a forewake region arising from shadowing of electrons. The electron forewakes resulting from supersonic flows past insulating and floating-potential obstacles are explored with 2D electrostatic particle-in-cell simulations, using a physical ion to electron mass ratio. Drift-energization is discovered to give rise to modifications to the electron velocity-distribution, including a slope-reversal, providing a novel drive of forewake instability. The slope-reversal is present at certain locations in all the simulations, and appears to be quite robustly generated. Wings of enhanced electron density are observed in some of the simulations, also associated with drift-energization. In the simulations with a floating-potential obstacle, the specific potential structure behind that obstacle allows fast electrons to cross the wake, giving rise to a more traditional shadowing-driven two-stream instability. Fluctuations associated with such instability are observed in the simulations, but this instability-mechanism is expected to be more sensitive to the plasma parameters than that associated with the slope-reversal.

  5. Flow induced dispersion analysis rapidly quantifies proteins in human plasma samples.

    Science.gov (United States)

    Poulsen, Nicklas N; Andersen, Nina Z; Østergaard, Jesper; Zhuang, Guisheng; Petersen, Nickolaj J; Jensen, Henrik

    2015-07-01

    Rapid and sensitive quantification of protein based biomarkers and drugs is a substantial challenge in diagnostics and biopharmaceutical drug development. Current technologies, such as ELISA, are characterized by being slow (hours), requiring relatively large amounts of sample and being subject to cumbersome and expensive assay development. In this work a new approach for quantification based on changes in diffusivity is presented. The apparent diffusivity of an indicator molecule interacting with the protein of interest is determined by Taylor Dispersion Analysis (TDA) in a hydrodynamic flow system. In the presence of the analyte the apparent diffusivity of the indicator changes due to complexation. This change in diffusivity is used to quantify the analyte. This approach, termed Flow Induced Dispersion Analysis (FIDA), is characterized by being fast (minutes), selective (quantification is possible in a blood plasma matrix), fully automated, and being subject to a simple assay development. FIDA is demonstrated for quantification of the protein Human Serum Albumin (HSA) in human plasma as well as for quantification of an antibody against HSA. The sensitivity of the FIDA assay depends on the indicator-analyte dissociation constant which in favourable cases is in the sub-nanomolar to picomolar range for antibody-antigen interactions. PMID:26031223

  6. Thermochemical Nonequilibrium 2D Modeling of Nitrogen Inductively Coupled Plasma Flow

    Science.gov (United States)

    Yu, Minghao; Yusuke, Takahashi; Hisashi, Kihara; Ken-ichi, Abe; Kazuhiko, Yamada; Takashi, Abe; Satoshi, Miyatani

    2015-09-01

    Two-dimensional (2D) numerical simulations of thermochemical nonequilibrium inductively coupled plasma (ICP) flows inside a 10-kW inductively coupled plasma wind tunnel (ICPWT) were carried out with nitrogen as the working gas. Compressible axisymmetric Navier-Stokes (N-S) equations coupled with magnetic vector potential equations were solved. A four-temperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles. The third-order accuracy electron transport properties (3rd AETP) were applied to the simulations. A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process. The flow characteristics such as thermal nonequilibrium, inductive discharge, effects of Lorentz force were made clear through the present study. It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field. The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT. supported by Grant-in-Aid for Scientific Research (No. 23560954), sponsored by the Japan Society for the Promotion of Science

  7. Stability analysis of viscous Z-pinch plasma with a sheared axial flow

    Institute of Scientific and Technical Information of China (English)

    Zhang Yang; Ding Ning

    2008-01-01

    Within the magnetohydrodynamics (MHD) frame, we analyse the effect of viscosity on magneto-Rayleigh-Taylor (MRT) instability in a Z-pinch configuration by using an exact method and an approximate method separately. It is demonstrated that the plasma viscosity indeed has a stabilization effect on the MRT mode in the whole wavenumber region, and its influence increases with the perturbation wavenumber increasing. After the characteristics and feasibility of the approximate method have been investigated, we apply it to the stability analysis of viscous plasma where a sheared axial flow (SAF) is involved, and we attain an analytical dispersion relation. It is suggested that the viscosity and the SAF are complemental with each other, and a wide wavenumber range of perturbation is possible to be restrained ifthe SAF and the viscosity are large enough. Finally, we calculate the possible value of viscosity parameter according to the current experimental conditions, and the results show that since the value of viscosity is much less than the threshold value, its mitigation effect is small enough to be neglected. The role of the viscosity in the stabilization becomes considerable only if special techniques are so developed that the Z-pinch plasma viscosity can be increased greatly.

  8. Efficiency of plasma actuator ionization in shock wave modification in a rarefied supersonic flow over a flat plate

    International Nuclear Information System (INIS)

    This paper describes experimental and numerical investigations focused on the shock wave modification, induced by a dc glow discharge, of a Mach 2 flow under rarefied regime. The model under investigation is a flat plate equipped with a plasma actuator composed of two electrodes. The glow discharge is generated by applying a negative potential to the upstream electrode, enabling the creation of a weakly ionized plasma. The natural flow (i.e. without the plasma) exhibits a thick laminar boundary layer and a shock wave with a hyperbolic shape. Images of the flow obtained with an ICCD camera revealed that the plasma discharge induces an increase in the shock wave angle. Thermal effects (volumetric, and at the surface) and plasma effects (ionization, and thermal non-equilibrium) are the most relevant processes explaining the observed modifications. The effect induced by the heating of the flat plate surface is studied experimentally by replacing the upstream electrode by a heating element, and numerically by modifying the thermal boundary condition of the model surface. The results show that for a similar temperature distribution over the plate surface, modifications induced by the heating element are lower than those produced by the plasma. This difference shows that other effects than purely thermal effects are involved with the plasma actuator. Measurements of the electron density with a Langmuir probe highlight the fact that the ionization degree plays an important role into the modification of the flow. The gas properties, especially the isentropic exponent, are indeed modified by the plasma above the actuator and upstream the flat plate. This leads to a local modification of the flow conditions, inducing an increase in the shock wave angle

  9. Suspension model for blood flow through a catheterized arterial stenosis with peripheral layer of plasma free from cells

    Science.gov (United States)

    Ponalagusamy, R.

    2016-06-01

    The present article describes the blood flow in a catheterized artery with radially symmetric and axially asymmetric stenosis. To understand the effects of red cell concentration, plasma layer thickness and catheter size simultaneously, blood is considered by a two-layered model comprising a core region of suspension of all the erythrocytes (particles) supposed to be a particle-fluid mixture and a peripheral zone of cell-free plasma. The analytical expressions for flow features, such as fluid phase and particle phase velocities, flow rate, wall shear stress and resistive force are obtained. It is witnessed that the presence of the catheter causes a substantial increase in the frictional forces on the walls of arterial stenosis and catheter, shear stress and flow resistance, in addition to that, have occurred due to the presence of red cells concentration (volume fraction density of the particles) and the absence of peripheral plasma layer near the wall of the stenosed artery. The introduction of an axially asymmetric nature of stenosis and plasma layer thickness causes significant reduction in flow resistance. One can notice that the two-phase fluid (suspension model) is more profound to the thickness of peripheral plasma layer and catheter than the single-phase fluid.

  10. ARRAYS OF BOTTLES OF PLUTONIUM NITRATE SOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Margaret A. Marshall

    2012-09-01

    In October and November of 1981 thirteen approaches-to-critical were performed on a remote split table machine (RSTM) in the Critical Mass Laboratory of Pacific Northwest Laboratory (PNL) in Richland, Washington using planar arrays of polyethylene bottles filled with plutonium (Pu) nitrate solution. Arrays of up to sixteen bottles were used to measure the critical number of bottles and critical array spacing with a tight fitting Plexiglas® reflector on all sides of the arrays except the top. Some experiments used Plexiglas shells fitted around each bottles to determine the effect of moderation on criticality. Each bottle contained approximately 2.4 L of Pu(NO3)4 solution with a Pu content of 105 g Pu/L and a free acid molarity H+ of 5.1. The plutonium was of low 240Pu (2.9 wt.%) content. These experiments were sponsored by Rockwell Hanford Operations because of the lack of experimental data on the criticality of arrays of bottles of Pu solution such as might be found in storage and handling at the Purex Facility at Hanford. The results of these experiments were used “to provide benchmark data to validate calculational codes used in criticality safety assessments of [the] plant configurations” (Ref. 1). Data for this evaluation were collected from the published report (Ref. 1), the approach to critical logbook, the experimenter’s logbook, and communication with the primary experimenter, B. Michael Durst. Of the 13 experiments preformed 10 were evaluated. One of the experiments was not evaluated because it had been thrown out by the experimenter, one was not evaluated because it was a repeat of another experiment and the third was not evaluated because it reported the critical number of bottles as being greater than 25. Seven of the thirteen evaluated experiments were determined to be acceptable benchmark experiments. A similar experiment using uranyl nitrate was benchmarked as U233-SOL-THERM-014.

  11. Flame stabilization by a plasma driven radical jet in a high speed flow

    Science.gov (United States)

    Choi, Woong-Sik

    In current afterburners combustion is stabilized by the high temperature, recirculating region behind bluff body flame holders, such as V-gutters. Blocking the high speed flow with bluff bodies causes a significant pressure drop, and heating the flame holder by the hot combustion product causes a thermal signature, which is a critical problem in a military jet. To reduce these problems, ignition methods using a high frequency (HF) spark discharge, or a radical jet generator (RJG) were developed. The HF discharge ignited and stabilized a flame successfully in a premixed methane-air flow. The electrical power consumption was very small compared to the combustion heat release, as long as the operating velocity was relatively low. However, a theoretical study showed that the ratio of the electrical power consumption to the heat generation by the stabilized flame increases rapidly with increasing flow velocity. For flame stabilization in a high velocity flow, the developed RJG showed much better performance than direct exposure to a plasma. The present study investigated the characteristics of a radical jet produced in a RJG and injected into a main combustor. The limits of flame stabilization by this jet was measured experimentally, and compared to those of bluff body flame holders. The flame holding performance of the radical jet was also experimentally compared to that of a thermal jet. The effect of radicals on flame stabilization was examined using CHEMKIN, and the limit of flame stabilization by the radical jet was estimated for a simple flow configuration using an approximate solution. The results suggest that the reduction of local spontaneous ignition delay time by active species in the radical jet and the longer length of a typical radical jet compared to the dimension of the recirculation zone behind a bluff body increases the maximum velocity at which a flame can be stabilized.

  12. Research status of fast flows and shocks in laboratory plasmas. Model experiments of astrophysical phenomena with intense lasers

    International Nuclear Information System (INIS)

    Small pulse intense lasers reproduce blast wave with ionization phenomena in laboratory. This report described the model experiments of generation of collisionless shock wave assuming that the intense laser plasma is source of fast plasma flow. Production of fast plasma flow, laser experiments of blast wave, blast wave in the uniform magnetic field, Richtmyer-Meshkov instability and vortex generation, and production of collisionless shock wave and magnetic field are stated. Phenomena observed in the solid by laser irradiation, Bow shock wave produced by an obstacle in front of laser plasma, shock waves produced on aluminum surface irradiated by 100 J laser pulse in N2 and Xe gases, generation of vortex and time course of its change when helium bubble was collided by shock wave in air, and distributions of electron density, magnetic field and electric field obtained by two dimension PIC simulations are illustrated. (S.Y.)

  13. Large-Eddy Simulations of Plasma Control for Separated Supersonic Flow

    Science.gov (United States)

    Bisek, Nicholas; Poggie, Jonathan

    2012-11-01

    The Navier-Stokes equations were solved using a high-fidelity time-implicit numerical scheme and an implicit large-eddy simulation approach to investigate plasma-based flow control for supersonic flow over a compression ramp. The configuration includes a flat-plate region to develop an equilibrium turbulent boundary-layer at Mach 2.25, which was validated against a set of experimental measurements. The fully turbulent boundary-layer flow traveled over a 24° ramp and produced an unsteady shock-induced separation. A control strategy to suppress the separation through a magnetically-driven gliding-arc actuator was explored. The size, strength, and placement of the actuator were developed based on recent experiments. Three control scenarios were examined: steady control, pulsing with a 50% duty cycle, and Joule heating. The results show the control mechanism reduced the time-mean separation length for all three situations. The case without pulsing and Joule heating was the most effective, with a reduction in the separation length by more than 75%. The controller was also found to significantly reduce the low-frequency content of the turbulent kinetic energy spectra within the separated region and reduce the total kinetic energy downstream of reattachment. Funded in part by the Air Force Office of Scientific Research, under a laboratory task monitored by Dr. J. Schmisseur, AFOSR/RSA. The computational resources were supported by a grant of supercomputer time from the U.S. Department of Defense.

  14. UNIVERSALITY AND INTERMITTENCY IN RELATIVISTIC TURBULENT FLOWS OF A HOT PLASMA

    International Nuclear Information System (INIS)

    With the aim of determining the statistical properties of relativistic turbulence and unveiling novel and non-classical features, we present the results of direct numerical simulations of driven turbulence in an ultrarelativistic hot plasma using high-order numerical schemes. We study the statistical properties of flows with average Mach numbers ranging from ∼0.4 to ∼1.7 and with average Lorentz factors up to ∼1.7. We find that flow quantities, such as the energy density or the local Lorentz factor, show large spatial variance even in the subsonic case as compressibility is enhanced by relativistic effects. The velocity field is highly intermittent, but its power spectrum is found to be in good agreement with the predictions of the classical theory of Kolmogorov. Overall, our results indicate that relativistic effects are able to significantly enhance the intermittency of the flow and affect the high-order statistics of the velocity field, while leaving unchanged the low-order statistics, which instead appear to be universal and in good agreement with the classical Kolmogorov theory. To the best of our knowledge, these are the most accurate simulations of driven relativistic turbulence to date.

  15. Elemental speciation by capillary electrophoresis with inductively coupled plasma spectrometry: A new approach by flow focusing® nebulization

    OpenAIRE

    Kovachev, Nikolay; Aguirre Pastor, Miguel Ángel; Hidalgo Núñez, Montserrat; Simitchiev, Kiril; Stefanova, Violeta M.; Kmetov, Veselin Y.; Canals Hernández, Antonio

    2014-01-01

    A novel system for Capillary Electrophoresis (CE) and Inductively Coupled Plasma (ICP) sample introduction that incorporates a dedicated Flow-Focusing® based nebulizer as aerosol generation unit is presented, aiming to provide high signal sensitivity and low detection limits for element speciation at short analysis times. To prove its viability, the system prototype constructed has been coupled to an inductively coupled plasma - optical emission spectrometer (ICP-OES) and an inductively coupl...

  16. Some features of the MHD flows in a coaxial channel with plasma injection through a ring slot

    International Nuclear Information System (INIS)

    The MHD stationary flows in a coaxial channel witch plasma injection through a ring slot are considered. Impact of the slot position on the flours integral characteristics is studied. It is shown that possible deviation of the magnetic field intensity distribution in the slot from the ∼ 1/r dependence slightly effects the outgoing jet geometry. The obtained results may be of interest by development of two-stage plasma accelerators

  17. Final Technical Report: Numerical and Experimental Investigation of Turbulent Transport Control via Shaping of Radial Plasma Flow Profiles

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Eugenio

    2014-05-02

    The strong coupling between the different physical variables involved in the plasma transport phenomenon and the high complexity of its dynamics call for a model-based, multivariable approach to profile control where those predictive models could be exploited. The overall objective of this project has been to extend the existing body of work by investigating numerically and experimentally active control of unstable fluctuations, including fully developed turbulence and the associated cross-field particle transport, via manipulation of flow profiles in a magnetized laboratory plasma device. Fluctuations and particle transport can be monitored by an array of electrostatic probes, and Ex B flow profiles can be controlled via a set of biased concentric ring electrodes that terminate the plasma column. The goals of the proposed research have been threefold: i- to develop a predictive code to simulate plasma transport in the linear HELCAT (HELicon-CAThode) plasma device at the University of New Mexico (UNM), where the experimental component of the proposed research has been carried out; ii- to establish the feasibility of using advanced model-based control algorithms to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles, iii- to investigate the fundamental nonlinear dynamics of turbulence and transport physics. Lehigh University (LU), including Prof. Eugenio Schuster and one full-time graduate student, has been primarily responsible for control-oriented modeling and model-based control design. Undergraduate students have also participated in this project through the National Science Foundation Research Experience for Undergraduate (REU) program. The main goal of the LU Plasma Control Group has been to study the feasibility of controlling turbulence-driven transport by shaping the radial poloidal flow profile (i.e., by controlling flow shear) via biased concentric ring electrodes.

  18. Vortex Structures in Heat Plasma Flows, Modeling of the Heat Flow Vector and Calculations of The Correlation Coefficients

    Czech Academy of Sciences Publication Activity Database

    Něnička, Václav; Šonský, Jiří

    Piscataway, Nj: IEEE Operations Center, 2008. s. 277-277. ISBN 978-1-4244-1930-2. [IEEE International Conference on Plasma Science - ICOPS 2008 /35./. 15.06.2008-19.06.2008, Karlsruhe ] Institutional research plan: CEZ:AV0Z20570509 Keywords : plasma jet * CCD camera * convective cell Subject RIV: BL - Plasma and Gas Discharge Physics

  19. Atmospheric pressure plasma chemical vapor deposition reactor for 100 mm wafers, optimized for minimum contamination at low gas flow rates

    Science.gov (United States)

    Anand, Venu; Nair, Aswathi R.; Shivashankar, S. A.; Mohan Rao, G.

    2015-08-01

    Gas discharge plasmas used for thinfilm deposition by plasma-enhanced chemical vapor deposition (PECVD) must be devoid of contaminants, like dust or active species which disturb the intended chemical reaction. In atmospheric pressure plasma systems employing an inert gas, the main source of such contamination is the residual air inside the system. To enable the construction of an atmospheric pressure plasma (APP) system with minimal contamination, we have carried out fluid dynamic simulation of the APP chamber into which an inert gas is injected at different mass flow rates. On the basis of the simulation results, we have designed and built a simple, scaled APP system, which is capable of holding a 100 mm substrate wafer, so that the presence of air (contamination) in the APP chamber is minimized with as low a flow rate of argon as possible. This is examined systematically by examining optical emission from the plasma as a function of inert gas flow rate. It is found that optical emission from the plasma shows the presence of atmospheric air, if the inlet argon flow rate is lowered below 300 sccm. That there is minimal contamination of the APP reactor built here, was verified by conducting an atmospheric pressure PECVD process under acetylene flow, combined with argon flow at 100 sccm and 500 sccm. The deposition of a polymer coating is confirmed by infrared spectroscopy. X-ray photoelectron spectroscopy shows that the polymer coating contains only 5% of oxygen, which is comparable to the oxygen content in polymer deposits obtained in low-pressure PECVD systems.

  20. Chemical, microbial and physical evaluation of commercial bottled waters in greater Houston area of Texas.

    Science.gov (United States)

    Saleh, Mahmoud A; Abdel-Rahman, Fawzia H; Woodard, Brooke B; Clark, Shavon; Wallace, Cecil; Aboaba, Adetoun; Zhang, Wenluo; Nance, James H

    2008-03-01

    Due to the increased demand and consumption of bottled water in the United States, there has been a growing concern about the quality of this product. Retail outlets sell local as well as imported bottled water to consumers. Three bottles for each of 35 different brands of bottled water were randomly collected from local grocery stores in the greater Houston area. Out of the 35 different brands, 16 were designated as spring water, 11 were purified and/or fortified tap water, 5 were carbonated water and 3 were distilled water. Chemical, microbial and physical properties of all samples were evaluated including pH, conductivity, bacteria counts, anion concentration, trace metal concentration, heavy metal and volatile organics concentration were determined in all samples. Inductively coupled plasma/mass spectrometry (ICPMS) was used for elemental analysis, gas chromatography with electron capture detector (GCECD) as well as gas chromatography mass spectrometry (GCMS) were used for analysis of volatile organics, ion chromatography (IC) and selective ion electrodes were used for the analysis of anions. Bacterial identification was performed using the Biolog software (Biolog, Inc., Hayward, Ca, USA). The results obtained were compared with guidelines of drinking water recommended by the International Bottled Water Association (IBWA), United States Food and Drug Administration (FDA), United States Environmental Protection Agency (EPA) and the World Health Organization (WHO) drinking water standard. The majority of the analyzed chemicals were below their respective drinking water standards for maximum admissible concentrations (MAC). Volatile organic chemicals were found to be below detection limits. Four of the 35 brands of the bottled water samples analyzed were found to be contaminated with bacteria. PMID:18273738

  1. The Center for Momentum Transport and Flow Organization in Plasmas - Final Scientific Report

    Energy Technology Data Exchange (ETDEWEB)

    Munsat, Tobin [Univ. of Colorado, Boulder, CO (United States)

    2015-12-14

    fields, all of the instabilities co-exist, leading to rich plasma dynamics and fully developed broadband turbulence. Edge-Turbulence and Flow Experiments in NSTX: A series of Gas Puff Imaging (GPI) observations on NSTX revealed a quasi-periodic oscillation in the plasma edge preceding the L-H transition in a limited set of neutral beam heated plasmas. These ~3 kHz flow oscillations exhibit both long wavelength and long correlation lengths, suggesting they are zonal-flow-like. The flow oscillations are strongly correlated with modulations of the level of edge turbulence, thus the system appears to undergo a predator--prey-type limit-cycle preceding the L-H transition. However, a clear trigger for the L-H transition was not observed. Reynolds stress profiles were obtained directly from image velocimetry for L-mode periods ELM-Precursor Studies in NSTX: A separate study based on NSTX-GPI data captured the two-dimensional evolution of edge-localized mode (ELM) precursors. Precursor events were observed preceding ELMs and ELM-induced H–L back-transitions in radio-frequency heated H-mode plasmas, and the growth of the precursor mode through the ELM filamentation was imaged in the plane perpendicular to the local B-field. Strong edge intensity modulations appeared to propagate in the electron diamagnetic direction while steadily drifting radially outwards. Intensity fluctuations were observed at frequencies around 20 kHz and wavenumbers of 0.05-0.2 cm-1. Upon growing to a trigger point, precursor fluctuations were seen to form filamentary structures and move into the scrape-off layer (SOL) explosively with radial velocities peaking at 8 km/s. Once in the SOL, filaments reverse their propagation direction and travel in the ion diamagnetic direction. Edge intensity fluctuations were strongly correlated with magnetic signals from Mirnov coils, and toroidally distributed coils estimated toroidal mode numbers of n=5-10. Quantitatively similar precursors have been

  2. Effect of Ambipolar Plasma Flow on the Penetration of Resonant Magnetic Perturbations in a Quasi-axisymmetric Stellarator

    International Nuclear Information System (INIS)

    A reference equilibrium for the U.S. National Compact Stellarator Experiment is predicted to be sufficiently close to quasi-symmetry to allow the plasma to flow in the toroidal direction with little viscous damping, yet to have sufficiently large deviations from quasi-symmetry that nonambipolarity significantly affects the physics of the shielding of resonant magnetic perturbations by plasma flow. The unperturbed velocity profile is modified by the presence of an ambipolar potential, which produces a broad velocity profile. In the presence of a resonant magnetic field perturbation, nonambipolar transport produces a radial current, and the resulting j x B force resists departures from the ambipolar velocity and enhances the shielding

  3. Surface activation of polyethylene with an argon atmospheric pressure plasma jet: Influence of applied power and flow rate

    International Nuclear Information System (INIS)

    Highlights: • Surface modification of polyethylene by an argon atmospheric pressure plasma jet. • Investigation of the influence of the applied power and argon flow rate. • Turbulence in the gas flow leads to a shorter afterglow. • Turbulence in the gas flow results in a lower wettability of the polyethylene. • Increasing the applied power increases the wettability of the polyethylene. - Abstract: Atmospheric pressure plasma technology offers attractive perspectives to alter the surface properties of polymers. Within this context, the surface modification of polyethylene (LDPE) by an argon atmospheric pressure plasma jet (APPJ) is profoundly investigated in this work. The influence of two different parameters (applied power and argon flow rate) on the plasma jet characteristics and the LDPE surface properties is examined in detail. In a first step, the APPJ is electrically and visually characterized and visual inspection of the afterglow clearly shows that mainly a variation in argon flow rate can result in a changing afterglow length. A maximum afterglow length is obtained at an argon flow rate of 1–1.25 slm, while higher gas flows result in turbulence leading to a shorter afterglow. Secondly, the surface modification of LDPE is examined using different analyzing techniques namely water contact angle (WCA) measurements for the wettability, X-ray photoelectron spectroscopy (XPS) for the chemical composition and atomic force microscopy (AFM) for the surface morphology determination. WCA measurements show that by increasing the applied power the wettability of the LDPE increases. Increasing the argon flow rate up to 1.25 slm gives a decrease in WCA value or in other words an increased wettability. From 1.25 slm on, an increase in argon flow rate during plasma treatment decreases the LDPE wettability as can be concluded from the increased WCA values. An increased wettability can be explained by the incorporation of oxygen moieties. By increasing the

  4. Surface activation of polyethylene with an argon atmospheric pressure plasma jet: Influence of applied power and flow rate

    Energy Technology Data Exchange (ETDEWEB)

    Van Deynse, A., E-mail: Annick.VanDeynse@ugent.be [Department Industrial Technology and Construction, Faculty of Engineering & Architecture, Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent (Belgium); Cools, P., E-mail: Pieter.Cools@ugent.be [Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering & Architecture, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Ghent (Belgium); Leys, C., E-mail: Christophe.Leys@ugent.be [Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering & Architecture, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Ghent (Belgium); De Geyter, N., E-mail: Nathalie.DeGeyter@ugent.be [Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering & Architecture, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Ghent (Belgium); Morent, R., E-mail: Rino.Morent@ugent.be [Research Unit Plasma Technology (RUPT), Department of Applied Physics, Faculty of Engineering & Architecture, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Ghent (Belgium)

    2015-02-15

    Highlights: • Surface modification of polyethylene by an argon atmospheric pressure plasma jet. • Investigation of the influence of the applied power and argon flow rate. • Turbulence in the gas flow leads to a shorter afterglow. • Turbulence in the gas flow results in a lower wettability of the polyethylene. • Increasing the applied power increases the wettability of the polyethylene. - Abstract: Atmospheric pressure plasma technology offers attractive perspectives to alter the surface properties of polymers. Within this context, the surface modification of polyethylene (LDPE) by an argon atmospheric pressure plasma jet (APPJ) is profoundly investigated in this work. The influence of two different parameters (applied power and argon flow rate) on the plasma jet characteristics and the LDPE surface properties is examined in detail. In a first step, the APPJ is electrically and visually characterized and visual inspection of the afterglow clearly shows that mainly a variation in argon flow rate can result in a changing afterglow length. A maximum afterglow length is obtained at an argon flow rate of 1–1.25 slm, while higher gas flows result in turbulence leading to a shorter afterglow. Secondly, the surface modification of LDPE is examined using different analyzing techniques namely water contact angle (WCA) measurements for the wettability, X-ray photoelectron spectroscopy (XPS) for the chemical composition and atomic force microscopy (AFM) for the surface morphology determination. WCA measurements show that by increasing the applied power the wettability of the LDPE increases. Increasing the argon flow rate up to 1.25 slm gives a decrease in WCA value or in other words an increased wettability. From 1.25 slm on, an increase in argon flow rate during plasma treatment decreases the LDPE wettability as can be concluded from the increased WCA values. An increased wettability can be explained by the incorporation of oxygen moieties. By increasing the

  5. Nonlinear 1-D stationary flows in multi-ion plasmas – sonic and critical loci – solitary and "oscillatory" waves

    Directory of Open Access Journals (Sweden)

    J. F. McKenzie

    2006-11-01

    Full Text Available One-dimensional stationary flows of a plasma consisting of two ion populations and electrons streaming against a heavy ion cloud are studied. The flow structure is critically governed by the position of sonic and critical points, at which the flow is shocked or choked. The concept of sonic and critical points is suitably generalized to the case of multi-ion plasmas to include a differential ion streaming. For magnetic field free flows, the sonic and critical loci in the (upx, uhx space coincide. Amongst the different flow patterns for the protons and heavy ions, there is a possible configuration composed of a "heavy ion shock" accompanied by a proton rarefaction. The magnetic field introduces a "stiffness" for the differential ion streaming transverse to the magnetic field. In general, both ion fluids respond similarly in the presence of "ion obstacle"; the superfast (subfast flows are decelerated (accelerated. The collective flow is choked when the dynamic trajectory (upx, uhx crosses the critical loci. In specific regimes the flow contains a sequence of solitary structures and as a result, the flow is strongly bunched. In each such substructure the protons are almost completely replaced by the heavies. A differential ion streaming is more accessible in the collective flows oblique to the magnetic field. Such a flexibility of the ion motion is determined by the properties of energy integrals and the Bernoulli energy functions of each ion species. The structure of flows, oblique to the magnetic field, depends critically on the velocity regime and demonstrates a rich variety of solitary and oscillatory nonlinear wave structures. The results of the paper are relevant to the plasma and field environments at comets and planets through the interaction with the solar wind.

  6. Kinetic description of the 3D electromagnetic structures formation in flows of expanding plasma coronas. Part 1: General

    Science.gov (United States)

    Gubchenko, V. M.

    2015-12-01

    In part I of the work, the physical effects responsible for the formation of low-speed flows in plasma coronas, coupled with formation of coronas magnetosphere-like structures, are described qualitatively. Coronal domain structures form if we neglect scales of spatial plasma dispersion: high-speed flows are accumulated in magnetic tubes of the open domains, while magnetic structures and low-speed flows are concentrated within boundaries of domains. The inductive electromagnetic process occurring in flows of the hot collisionless plasma is shown to underlie the formation of magnetosphere-like structures. Depending on the form of the velocity distribution function of particles (PDF), a hot flow differently reveals its electromagnetic properties, which are expressed by the induction of resistive and diamagnetic scales of spatial dispersion. These determine the magnetic structure scales and structure reconstruction. The inductive electromagnetic process located in lines of the plasma nontransparency and absorption, in which the structures of excited fields are spatially aperiodic and skinned to the magnetic field sources. The toroidal and dipole magnetic sources of different configurations are considered for describing the corona structures during the solar maximum and solar minimum.

  7. Characteristics of flow injection inductively coupled plasma mass spectrometry for boron analysis in steels

    International Nuclear Information System (INIS)

    A method for the determination of Boron in steels by FI-ICP-MS is described. It is shown that flow injection (FI) can alleviate problems arising from high amounts of dissolved solids in Inductively Coupled Plasma Mass Spectrometry (ICP-MS) due to the capability to operate with microliter amounts of sample with a rapid sample rate. Sample dissolution was carried out in a microwave oven using diluted aqua regia (HCl+HNO3, 3+1) and high pressure digestion vessels, which gave notable advantages over conventional dissolution techniques, such as lower costs, greater volatile retention, reduced contamination and faster dissolution rates. The operating parameters in flow injection ICP-MS, such as carrier flow rate, nebulizer flow rate, and injection volume were established. The detection limit obtained when direct sample nebulization was used, with a 0.05% m/v Fe concentration, was 1.2 μg·g-1 B, compared to a detection limit of 0.2 μg·g-1 when the FI system was used with samples containing a higher concentration of dissolved solids (0.5% m/v Fe). The influence of the internal standard on precision and accuracy was studied and Beryllium was selected as the internal standard. The RSDs obtained for four peak area determinations of 200 μl injection volumes of a solution of 100 ng·ml-1 B in the presence of 0.5% m/v Fe were below 1.5%. The accuracy of the method proposed was verified by analyzing Reference Materials (EURONORM-CRM 097-1; BCS 456, 457 and 460; NBS 361, 363 and 365), using an external calibration system with calibration samples, prepared from a standard Boron solution, in the same acid medium as the test sample solutions. (author)

  8. Elemental composition of chromium/titanium system after compression plasma flows influence

    International Nuclear Information System (INIS)

    The results of elemental composition of chromium/titanium system treated by compression plasma flows (CPF) are presented in the work. The samples were prepared with chromium coating deposition (1 μm thick) and next CPF influence with absorbed energy density 19 - 35 J/cm2. Numerical solution of thermo conductivity equation showed that the CPF treatment provides the melting of the near surface layer and high solidification speed (105 - 107 K/s). The nitride TiN forms in result of high temperature (more than 2000 K) as an outer dendrite layer. This layer prevents the nitrogen penetration into the melted zone and because of it, the nitrogen concentration is decreased with absorbed energy density rising. Also the outer nitride layer results in formation near surface area with decreased chromium concentration. (authors)

  9. Flash pyrolysis of agricultural residues using a plasma heated laminar entrained flow reactor

    International Nuclear Information System (INIS)

    In order to study the volatilization characteristics of biomass particles at flash heating rates, a plasma heated laminar entrained flow reactor (PHLEFR) was designed and built in our lab. Two agricultural residues, wheat straw and corn stalk, were chosen as feedstock for pyrolysis which were conducted on the PHLEFR with the aim of determining the extent of thermal decomposition at high heating rate (more than 104oCs-1). Based on the experimental data, a first order kinetic model was introduced and the relevant kinetic parameters (apparent active energy and apparent frequency factor) were determined for the two straws: E=31.51kJmol-1, A=1028s-1(wheat straw) and E=33.74kJmol-1, A=1013s-1(corn stalk). The predicted conversion of the fitted model to the experimental data provided general agreements when one considered the experimental errors

  10. Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

    Science.gov (United States)

    Du, Hai; Shi, Zhiwei; Cheng, Keming; Wei, Dechen; Li, Zheng; Zhou, Danjie; He, Haibo; Yao, Junkai; He, Chengjun

    2016-06-01

    Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

  11. Water Jets from Bottles, Buckets, Barrels, and Vases with Holes

    Science.gov (United States)

    Lopac, Vjera

    2015-03-01

    Observation of the water jets flowing from three equidistant holes on the side of a vertical cylindrical bottle is an interesting and widely used didactical experiment illustrating the laws of fluids in motion. In this paper we analyze theoretically and numerically the ranges of the stationary water jets flowing from various rotationally symmetric vessels with holes, and their dependence on the height of the holes above the bottom, on thickness of the block supporting the vessel, and on different shapes of the vessel profile. This investigation was motivated by controversial descriptions and illustrations repeatedly found in physics textbooks and by the fact that previously in the physics teaching literature only the cylindrical vessel was treated.

  12. On the theory of MHD waves in a shear flow of a magnetized turbulent plasma

    Science.gov (United States)

    Mishonov, Todor M.; Maneva, Yana G.; Dimitrov, Zlatan D.; Hristov, Tihomir S.

    The set of equations for magnetohydrodynamic (MHD) waves in a shear flow is consecutively derived. This investigation is devoted on the wave heating of space plasmas. The proposed scenario involves the presence of a self-sustained turbulence and magnetic field. In the framework of Langevin--Burgers approach the influence of the turbulence is described by an additional external random force in the MHD system. Kinetic equation for the spectral density of the slow magnetosonic (Alfvénic) mode is derived in the short wavelength (WKB) approximation. The results show a pressing need for conduction of numerical Monte Carlo (MC) simulations with a random driver to take into account the influence of the long wavelength modes and to give a more precise analytical assessment of the short ones. Realistic MC calculations for the heating rate and shear stress tensor should give an answer to the perplexing problem for the missing viscosity in accretion disks and reveal why the quasars are the most powerful sources of light in the universe. It is supposed that the heating mechanism by alfvén waves absorption is common for many kinds of space plasmas from solar corona to active galactic nuclei and the solution of these longstanding puzzles deserves active interdisciplinary research. The work is illustrated by typical solutions of MHD equations and their spectral densities obtained by numerical calculations or by analytical solutions with the help of Heun functions. The amplification coefficient of slow magnetosonic wave in shear flow is analytically calculated. Pictorially speaking, if in WKB approximation we treat Alfvén waves as particles -- this amplification is effect of ``lasing of alfvons.''

  13. Evidence for modified transport due to sheared ExB flows in high-temperature plasmas

    International Nuclear Information System (INIS)

    Sheared mass flows are generated in many fluids and are often important for the dynamics of instabilities in these fluids. Similarly, large values of the ExB velocity have been observed in magnetic confinement machines and there is theoretical and experimental evidence that sufficiently large shear in this velocity may stabilize important instabilities. Two examples of this phenomenon have been observed in the DIII endash D tokamak. In the first example, sufficient heating power can lead to the L-H transition (transition from low-mode to high-mode confinement), a rapid improvement in confinement in the boundary layer of the plasma. For discharges with heating power close to the threshold required to get the transition, changes in the edge radial electric field are observed to occur prior to the transition itself. In the second example, certain classes of discharges with toroidal momentum input from neutral beam injection exhibit a further improvement of confinement in the plasma core leading to a regime called the VH endash mode. In both examples, the region of improved confinement is characterized by an increase of shear in the radial electric field Er, reduced levels of turbulence and increases in gradients of temperatures and densities. These observations are consistent with the hypothesis that the improved confinement is caused by an increase in shear of the ExB velocity which leads to a reduction of turbulence. For the VH endash mode, the dominant term controlling Er is the toroidal rotation vφ, indicating that the Er profile is controlled by the source and transport of toroidal momentum. At the edge of the plasma, indirect measurements indicate that the change in Er is initiated by a change in the VxB velocity of the main ions but at later times is dominated by the ion diamagnetic velocity. copyright 1995 American Institute of Physics

  14. Radially resolved measurements of plasma rotation and flow-velocity shear in the Maryland Centrifugal Experiment

    International Nuclear Information System (INIS)

    In diagnosing the Maryland Centrifugal Experiment (MCX) [R. F. Ellis et al., Phys. of Plasmas 8, 2057 (2001)], earlier spectroscopic measurements of averaged plasma rotation velocities have been upgraded to include radial distributions, using a five-channel fiber-optic collection system. Detailed information from each view is now possible with an 8-times increase in spectral resolution, by using a 2 m spectrograph and a 2400 lines/mm grating. Inversion of the integrated chordal radiation into a radial dependence of local emissions is performed by two methods: (a) an iterative simulation beginning with assumed emissions in five axially concentric cylindrical zones followed by summation along the five viewing chords, and (b) inversion of a combination of dual Abel-type matrices. The radial profiles of the absolute velocities derived cover a range from 20 to 70 km/s for both C+ and C++ impurity ions. Previous apparent differences in velocities between ions from a single chordal observation are now explained by the measured radial dependence of velocities and relative emissions. An important result is the first direct and quantitative measurement on MCX of a radial shear in rotational flow velocity as large as 9x105 s-1, 9 times a threshold of 1x105 s-1 for magnetohydrodynamic stability. Stark-broadened hydrogen Balmer-series spectral lines provide both a value for electron density of Ne=(8.5±1.5)1014 cm-3 and supporting data for radial particle distributions

  15. Evidence for modified transport due to sheared E x B flows in high-temperature plasmas

    International Nuclear Information System (INIS)

    Sheared mass flows are generated in many fluids and are often important for the dynamics of instabilities in these fluids. Similarly, large values of the E x B velocity have been observed in magnetic confinement machines and there is theoretical and experimental evidence that sufficiently large shear in this velocity may stabilize important instabilities. Two examples of this phenomenon have been observed in the DIII-D tokamak. In the first example, sufficient heating power can lead to the L-H transition, a rapid improvement in confinement in the boundary layer of the plasma. For discharges with heating power close to the threshold required to get the transition, changes in the edge radial electric field are observed to occur prior to the transition itself. In the second example, certain classes of discharges with toroidal momentum input from neutral beam injection exhibit a further improvement of confinement in the plasma core leading to a regime called the VH-mode. In both examples, the region of improved confinement is characterized by an increase of shear in the radial electric field Er, reduced levels of turbulence and increases in gradients of temperatures and densities. These observations are consistent with the hypothesis that the improved confinement is caused by an increase in shear of the E x B velocity which leads to a reduction of turbulence. For the VH-mode, the dominant term controlling Er is the toroidal rotation vφ, indicating that the Er profile is controlled by the source and transport of toroidal momentum

  16. Supersonic shear flows in laser driven high-energy-density plasmas created by the Nike laser

    Science.gov (United States)

    Harding, E. C.; Drake, R. P.; Gillespie, R. S.; Grosskopf, M. J.; Ditmar, J. R.; Aglitskiy, Y.; Weaver, J. L.; Velikovich, A. L.; Plewa, T.

    2008-11-01

    In high-energy-density (HED) plasmas the Kelvin-Helmholtz (KH) instability plays an important role in the evolution of Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) unstable interfaces, as well as material interfaces that experience the passage one or multiple oblique shocks. Despite the potentially important role of the KH instability few experiments have been carried out to explore its behavior in the high-energy-density regime. We report on the evolution of a supersonic shear flow that is generated by the release of a high velocity (>100 km/s) aluminum plasma onto a CRF foam (ρ = 0.1 g/cc) surface. In order to seed the Kelvin-Helmholtz (KH) instability various two-dimensional sinusoidal perturbations (λ = 100, 200, and 300 μm with peak-to-valley amplitudes of 10, 20, and 30 μm respectively) have been machined into the foam surface. This experiment was performed using the Nike laser at the Naval Research Laboratory.

  17. Spatiotemporal Structure of the Turbulence-flow Interaction at the L-H Transition in TJ-II Plasma

    International Nuclear Information System (INIS)

    Full text: The spatiotemporal behaviour of the interaction between turbulence and flows has been studied close to the L-H transition threshold conditions in the edge region of TJ-II plasmas. The temporal dynamics of the interaction displays an oscillatory behaviour with a characteristic predator-prey relationship. This intermediate oscillatory transient stage has been seen in L-H transition experiments in some other devices. However, in those experiments, as in the Kim and Diamond predator-prey theory model, only the temporal dynamics of the turbulence-flow interaction is studied. In TJ-II, dedicate experiments have been carried out to study the spatial evolution of the turbulence-flow oscillation pattern. Radial outward and inward propagation velocities of the turbulence-flow front are found. As the turbulence-flow front propagates outwards, the turbulence-flow events generate a dual shear layer and thus enhance the formation of the radial electric field well. A possible explanation for the spatiotemporal evolution of the oscillation-pattern could be linked to the radial spreading of the plasma turbulence from the plasma core to the edge barrier. As the turbulence propagates towards the barrier, the associated turbulence driven flow generates the inner shear layer which in turn regulates the turbulence level. The observations could be also figured out in terms of turbulent bursts propagating toward the plasma edge. These turbulent bursts could be generated in the plasma interior due to instabilities linked, for instance, to the magnetic topology. A reversal in the front propagation velocity is observed in some particular cases after a quiet period without oscillations. In those cases the oscillation-pattern arises at the outer shear layer position and propagates towards the plasma interior. The results indicate that the edge shear flow linked to the L-H transition can behave either as a slowing-down, damping mechanism of outward propagating turbulent-flow

  18. Supersonic flow with shock waves. Monte-Carlo calculations for low density plasma. I; Flujo supersonico de un plasma con ondas de choque, un metodo de montecarlo para plasmas de baja densidad, I.

    Energy Technology Data Exchange (ETDEWEB)

    Almenara, E.; Hidalgo, M.; Saviron, J. M.

    1980-07-01

    This Report gives preliminary information about a Monte Carlo procedure to simulate supersonic flow past a body of a low density plasma in the transition regime. A computer program has been written for a UNIVAC 1108 machine to account for a plasma composed by neutral molecules and positive and negative ions. Different and rather general body geometries can be analyzed. Special attention is played to tho detached shock waves growth In front of the body. (Author) 30 refs.

  19. 27 CFR 26.319 - Used liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Used liquor bottles. 26..., DEPARTMENT OF THE TREASURY LIQUORS LIQUORS AND ARTICLES FROM PUERTO RICO AND THE VIRGIN ISLANDS Requirements for Liquor Bottles § 26.319 Used liquor bottles. The appropriate TTB officer may pursuant...

  20. 27 CFR 31.203 - Possession of used liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Possession of used liquor... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS ALCOHOL BEVERAGE DEALERS Reuse and Possession of Used Liquor Bottles § 31.203 Possession of used liquor bottles. The possession of used liquor bottles by any...

  1. 27 CFR 19.633 - Distinctive liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... TTB officer if the bottles are found to— (1) Meet the requirements of 27 CFR part 5; (2) Be... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Distinctive liquor bottles..., DEPARTMENT OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Liquor Bottle and Label Requirements...

  2. 27 CFR 31.202 - Possession of refilled liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... liquor bottles. 31.202 Section 31.202 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS ALCOHOL BEVERAGE DEALERS Reuse and Possession of Used Liquor Bottles § 31.202 Possession of refilled liquor bottles. No person who sells, or offers for...

  3. 27 CFR 27.209 - Used liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Used liquor bottles. 27..., DEPARTMENT OF THE TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Requirements for Liquor Bottles § 27.209 Used liquor bottles. The appropriate TTB officer may pursuant to letterhead...

  4. 27 CFR 24.308 - Bottled or packed wine record.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottled or packed wine record. 24.308 Section 24.308 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Records and Reports § 24.308 Bottled or packed wine record. A proprietor who bottles, packs,...

  5. 27 CFR 24.255 - Bottling or packing wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottling or packing wine. 24.255 Section 24.255 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine Bottling, Packing, and Labeling of Wine § 24.255 Bottling...

  6. 27 CFR 24.256 - Bottle aging wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottle aging wine. 24.256 Section 24.256 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine Bottling, Packing, and Labeling of Wine § 24.256 Bottle aging wine....

  7. 21 CFR 1250.42 - Water systems; constant temperature bottles.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water systems; constant temperature bottles. 1250...; constant temperature bottles. (a) The water system, whether of the pressure or gravity type, shall be... at all times as to prevent contamination of the water. (e) Constant temperature bottles and...

  8. 27 CFR 19.749 - Bottling and packaging record.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bottling and packaging record. 19.749 Section 19.749 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... Account § 19.749 Bottling and packaging record. The bottling and packaging record shall be prepared...

  9. An Experimental Study of the Drag Force on a Cylinder Exposed to an Argon Thermal Plasma Cross Flow

    Institute of Scientific and Technical Information of China (English)

    XinTao; XiChen; 等

    1992-01-01

    Experimental data are presented concerning the drag force on a cylinder exposed to an argon plasma cross flow with temperatures about 104 K and velocities about 102 m/s.Using a method of sweeping a cylindrical probe across an argon plasma jet,the total drag force on the cylinder can be measured as a function of the lateral distance of cylindrical probe with respect to the plasma-jet axis.Through the Abel inversion,the drag force for per unit of cylinderlength and thus the drag coefflcient of cylinder have been measured under plasma conditions and compared with the values obtained from the standard drag curve of the cylinder in an isothermal flow.Experimental results show that the measured grag forces are always less than their counterparts read from the standard drag curve with the smae Reynolds numbers based on the oncoming plasma properties.Thew drag force on the cylinder exoposed to a thermal plasma flow is shown to be approximately proportional to the square root of cylinder diameter in the present experiment and it increases slightly proportional to the square root of cylinder diameter in the present experiment and if increases slightly with increasing surface temperature of the cylinder,.It is also shown that applying a voltage between the drag prode and the anode of the plasma jet generator has little effect on the drag force of cylinder under the experimental conditions.The drag force on a cylinder with finite length exposed to an argon plasma with the axis parallel to the plams jet is independent of ration of cylinder length to its dismeter L/d for the cases when L/d≤1.

  10. Gas Flow and Electric Field Characterization in Plasma Jets for Biomedical Applications: From Single Jet to Multi Jet Arrays

    Science.gov (United States)

    Robert, Eric

    2015-09-01

    This work reports first on time-resolved measurement of longitudinal and radial electric fields (EF) associated with plasma propagation in dielectric capillaries. Plasma propagation occurs in a region where longitudinal EF exists ahead the ionization front position revealed from plasma emission with ICCD measurement. The ionization front propagation induces the sudden rise of a radial EF component. Both of these EF components have a few kV/cm in amplitude for helium or neon plasmas. Their amplitude is kept almost constant along a few tens of cm long capillary. The key role of the voltage pulse polarity and the drastic impact of the presence of a target in front of the plasma jet are discussed from Schlieren images. All these experimental measurements are in excellent agreement with model calculations which are used to infer EF data on capillary axis. EF diagnostics in the plasma plume in the free jet mode but also in contact with various targets is proposed. The combination of intense transient EF, both of ns and µs duration, together with significant transient reactive species generation during plasma jet treatments may be reconsidered. Typical EF amplitudes likely to induce electrostimulation, electroporation are indeed probably achieved in many in vivo protocols. Stimulation of tissue oxygenation, blood flow rate modulation and more recently immune system triggering may be examples where EF could play a significant role. The second part of this work is dedicated to the development of multi jets, using two different setups, based on a single plasma source. Plasma splitting in dielectric tubes drilled with sub millimetric orifices, but also plasma transfer across metallic tubes equipped with such orifices are analyzed from ICCD imaging and time resolved EF measurements. This allows for the design of plasma jet arrays but also emphasizes the necessity to account for voltage pulse polarity, target potential status, consecutive helium flow modulation and

  11. Higher order nonlocal formalism for linear analysis of a magnetized multispecies plasma with inhomogeneous flows

    International Nuclear Information System (INIS)

    The formalism necessary to study the collective properties of a plasma system with inhomogeneous flows is nonlocal and generally in the form of an integrodifferential equation. Usually the eigenvalue condition is reduced to a second-order differential equation for simplicity. While the gross physical behavior of the system can be obtained from the second-order differential equation level of description, higher-order corrections are necessary for greater accuracy. The limit in which the scale-size of the velocity inhomogeneity is large compared to the ion gyroradius is considered and a transverse flow profile sharply localized in space (open-quotes top-hatclose quotes profile) is assumed. In this limit, a simple analytical method for the solution of the general eigenvalue condition to all orders is developed. A comparison of the properties of the solutions obtained from the second-order differential equation level of description with those obtained from higher orders is presented. Both the resonant (dissipative) and the nonresonant (reactive) effects of velocity shear are considered. It is found that while the overall features are well represented by the second-order level of description, the higher-order corrections moderate the destabilizing effects due to velocity shear, which can be quite significant in some cases. copyright 1998 American Institute of Physics

  12. Formation of a Quasi-Neutral Plasma in a Hydrodynamic Channel Flow

    International Nuclear Information System (INIS)

    The ignition and breakdown processes in the pre-ionized gaseous flow through a duct with electrodes, to which an exterior electric field is applied, are evaluated. Analytical expressions describing the temporal development of the electron density distribution in the ignition period and the plasma distribution in the breakdown period are presented. Approximate formulae for the electric fields required for ignition and multiplication of ionization within a definitive time, respectively, are given. Further, a relation for the critical velocity, beyond which the discharge is blown out, is given. The theory is shown to be in qualitative agreement with experimental results obtained with a shock tube using noble gases at 1 atmosphere pressure and gas temperatures of 2000-3000°K. It is concluded that toll obtain effective ionization at feasible electric field strengths and the above gas conditions, Penning gas mixtures should be used. Another conclusion is that the breakdown field, transverse to a strong magnetic field applied, is greatly increased. Finally, it is demonstrated that at the high gas velocities employed, the gas discharge formed will subsequently always be extinguished by the flow, thereby generating continuous reignition and downstream propagation of discharge columns. (author)

  13. Rotation of the magnetic field in Earth's magnetosheath by bulk magnetosheath plasma flow

    Directory of Open Access Journals (Sweden)

    M. Longmore

    2006-03-01

    Full Text Available Orientations of the observed magnetic field in Earth's dayside magnetosheath are compared with the predicted field line-draping pattern from the Kobel and Flückiger static magnetic field model. A rotation of the overall magnetosheath draping pattern with respect to the model prediction is observed. For an earthward Parker spiral, the sense of the rotation is typically clockwise for northward IMF and anticlockwise for southward IMF. The rotation is consistent with an interpretation which considers the twisting of the magnetic field lines by the bulk plasma flow in the magnetosheath. Histogram distributions describing the differences between the observed and model magnetic field clock angles in the magnetosheath confirm the existence and sense of the rotation. A statistically significant mean value of the IMF rotation in the range 5°-30° is observed in all regions of the magnetosheath, for all IMF directions, although the associated standard deviation implies large uncertainty in the determination of an accurate value for the rotation. We discuss the role of field-flow coupling effects and dayside merging on field line draping in the magnetosheath in view of the evidence presented here and that which has previously been reported by Kaymaz et al. (1992.

  14. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    Science.gov (United States)

    Brust, M.; Aouane, O.; Thiébaud, M.; Flormann, D.; Verdier, C.; Kaestner, L.; Laschke, M. W.; Selmi, H.; Benyoussef, A.; Podgorski, T.; Coupier, G.; Misbah, C.; Wagner, C.

    2014-03-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects.

  15. The effect of plasma shear flow on drift Alfven instabilities of a finite beta plasma and on anomalous heating of ions by ion cyclotron turbulence

    Science.gov (United States)

    Jo, Young Hyun; Lee, Hae June; Mikhailenko, Vladimir V.; Mikhailenko, Vladimir S.

    2016-01-01

    It was derived that the drift-Alfven instabilities with the shear flow parallel to the magnetic field have significant difference from the drift-Alfven instabilities of a shearless plasma when the ion temperature is comparable with electron temperature for a finite plasma beta. The velocity shear not only modifies the frequency and the growth rate of the known drift-Alfven instability, which develops due to the inverse electron Landau damping, but also triggers a combined effect of the velocity shear and the inverse ion Landau damping, which manifests the development of the ion kinetic shear-flow-driven drift-Alfven instability. The excited unstable waves have the phase velocities along the magnetic field comparable with the ion thermal velocity, and the growth rate is comparable with the frequency. The development of this instability may be the efficient mechanism of the ion energization in shear flows. The levels of the drift--Alfven turbulence, resulted from the development of both instabilities, are determined from the renormalized nonlinear dispersion equation, which accounts for the nonlinear effect of the scattering of ions by the electromagnetic turbulence. The renormalized quasilinear equation for the ion distribution function, which accounts for the same effect of the scattering of ions by electromagnetic turbulence, is derived and employed for the analysis of the ion viscosity and ions heating, resulted from the interactions of ions with drift-Alfven turbulence. In the same way, the phenomena of the ion cyclotron turbulence and anomalous anisotropic heating of ions by ion cyclotron plasma turbulence has numerous practical applications in physics of the near-Earth space plasmas. Using the methodology of the shearing modes, the kinetic theory of the ion cyclotron turbulence of the plasma with transverse current with strong velocity shear has been developed.

  16. A multiple time stepping algorithm for efficient multiscale modeling of platelets flowing in blood plasma

    Science.gov (United States)

    Zhang, Peng; Zhang, Na; Deng, Yuefan; Bluestein, Danny

    2015-03-01

    We developed a multiple time-stepping (MTS) algorithm for multiscale modeling of the dynamics of platelets flowing in viscous blood plasma. This MTS algorithm improves considerably the computational efficiency without significant loss of accuracy. This study of the dynamic properties of flowing platelets employs a combination of the dissipative particle dynamics (DPD) and the coarse-grained molecular dynamics (CGMD) methods to describe the dynamic microstructures of deformable platelets in response to extracellular flow-induced stresses. The disparate spatial scales between the two methods are handled by a hybrid force field interface. However, the disparity in temporal scales between the DPD and CGMD that requires time stepping at microseconds and nanoseconds respectively, represents a computational challenge that may become prohibitive. Classical MTS algorithms manage to improve computing efficiency by multi-stepping within DPD or CGMD for up to one order of magnitude of scale differential. In order to handle 3-4 orders of magnitude disparity in the temporal scales between DPD and CGMD, we introduce a new MTS scheme hybridizing DPD and CGMD by utilizing four different time stepping sizes. We advance the fluid system at the largest time step, the fluid-platelet interface at a middle timestep size, and the nonbonded and bonded potentials of the platelet structural system at two smallest timestep sizes. Additionally, we introduce parameters to study the relationship of accuracy versus computational complexities. The numerical experiments demonstrated 3000x reduction in computing time over standard MTS methods for solving the multiscale model. This MTS algorithm establishes a computationally feasible approach for solving a particle-based system at multiple scales for performing efficient multiscale simulations.

  17. A Multiple Time Stepping Algorithm for Efficient Multiscale Modeling of Platelets Flowing in Blood Plasma

    Science.gov (United States)

    Zhang, Peng; Zhang, Na; Deng, Yuefan; Bluestein, Danny

    2015-01-01

    We developed a multiple time-stepping (MTS) algorithm for multiscale modeling of the dynamics of platelets flowing in viscous blood plasma. This MTS algorithm improves considerably the computational efficiency without significant loss of accuracy. This study of the dynamic properties of flowing platelets employs a combination of the dissipative particle dynamics (DPD) and the coarse-grained molecular dynamics (CGMD) methods to describe the dynamic microstructures of deformable platelets in response to extracellular flow-induced stresses. The disparate spatial scales between the two methods are handled by a hybrid force field interface. However, the disparity in temporal scales between the DPD and CGMD that requires time stepping at microseconds and nanoseconds respectively, represents a computational challenge that may become prohibitive. Classical MTS algorithms manage to improve computing efficiency by multi-stepping within DPD or CGMD for up to one order of magnitude of scale differential. In order to handle 3–4 orders of magnitude disparity in the temporal scales between DPD and CGMD, we introduce a new MTS scheme hybridizing DPD and CGMD by utilizing four different time stepping sizes. We advance the fluid system at the largest time step, the fluid-platelet interface at a middle timestep size, and the nonbonded and bonded potentials of the platelet structural system at two smallest timestep sizes. Additionally, we introduce parameters to study the relationship of accuracy versus computational complexities. The numerical experiments demonstrated 3000x reduction in computing time over standard MTS methods for solving the multiscale model. This MTS algorithm establishes a computationally feasible approach for solving a particle-based system at multiple scales for performing efficient multiscale simulations. PMID:25641983

  18. Role of the Kelvin-Helmholtz instability in the evolution of magnetized relativistic sheared plasma flows.

    Science.gov (United States)

    Hamlin, Nathaniel D; Newman, William I

    2013-04-01

    We explore, via analytical and numerical methods, the Kelvin-Helmholtz (KH) instability in relativistic magnetized plasmas, with applications to astrophysical jets. We solve the single-fluid relativistic magnetohydrodynamic (RMHD) equations in conservative form using a scheme which is fourth order in space and time. To recover the primitive RMHD variables, we use a highly accurate, rapidly convergent algorithm which improves upon such schemes as the Newton-Raphson method. Although the exact RMHD equations are marginally stable, numerical discretization renders them unstable. We include numerical viscosity to restore numerical stability. In relativistic flows, diffusion can lead to a mathematical anomaly associated with frame transformations. However, in our KH studies, we remain in the rest frame of the system, and therefore do not encounter this anomaly. We use a two-dimensional slab geometry with periodic boundary conditions in both directions. The initial unperturbed velocity peaks along the central axis and vanishes asymptotically at the transverse boundaries. Remaining unperturbed quantities are uniform, with a flow-aligned unperturbed magnetic field. The early evolution in the nonlinear regime corresponds to the formation of counter-rotating vortices, connected by filaments, which persist in the absence of a magnetic field. A magnetic field inhibits the vortices through a series of stages, namely, field amplification, vortex disruption, turbulent breakdown, and an approach to a flow-aligned equilibrium configuration. Similar stages have been discussed in MHD literature. We examine how and to what extent these stages manifest in RMHD for a set of representative field strengths. To characterize field strength, we define a relativistic extension of the Alfvénic Mach number M(A). We observe close complementarity between flow and magnetic field behavior. Weaker fields exhibit more vortex rotation, magnetic reconnection, jet broadening, and intermediate turbulence

  19. Smart specialisation - Old wine in new bottles or new wine in old bottles?

    OpenAIRE

    Bjorn Asheim

    2013-01-01

    The paper deals with the problematic addressed in the above subtitle; i.e. that ?smart specialization? indicates old wine (specialization) in new bottles (smart), but is in fact new wine (diversity) in old bottles (specialization). This confusion will obviously lead to problems with respect to the content, communication and implementation of the strategy, and, thus, potentially reduce its impact. Specializaiton has been the main industrial and regional development strategy since the days of M...

  20. Dr. von Braun Discusses 'Bottle Suit' Concept

    Science.gov (United States)

    1954-01-01

    Dr. Wernher von Braun (center), then Chief of the Guided Missile Development Division at Redstone Arsenal, Alabama, discusses a 'bottle suit' model with Dr. Heinz Haber (left), an expert on aviation medicine, and Willey Ley, a science writer on rocketry and space exploration. The three men were at the Disney studios appearing in the motion picture, entitled 'Man in Space.'

  1. IS BOTTLE GOURD A NATURAL GUARD??

    Directory of Open Access Journals (Sweden)

    Kaur Satbir

    2011-06-01

    Full Text Available Bottle gourd is one of the excellent fruits gifted by nature to human beings having composition of all the essential constituents that are required for good health and quality human life. Lagenaria siceraria (Cucurbitaceae, popularly known as bottle gourd, lauki or ghiya, is a climbing plant, which bears hard-shelled and bottle-shaped gourds as fruits. It forms an excellent diet being rich in vitamins, iron and minerals. The fruit is reported to contain the triterepenoide cucurbitacins B, D, G, H, two sterols viz., fucosterol and campesterol, aerpene byonolic acid (an allergic compound, flavone-C glycosides (a ribosome inactivating protein and lagenin. Extract of the ghiya seeds show antibiotic activity. The fruit juice is helpful in constipation, premature graying hair, urinary disorders and insomnia. Lauki has the highest content of choline among all the vegetables known to man till date, which serves as the precursor of neurotransmitter acetylcholine, which in turn is crucial for retaining and enhancing memory. Furthermore, Lagenaria siceraria is a vegetable useful in the management of many diseases like cardiac disorders, hepatic diseases and ulcer. Bottle gourd juice helps to regulate blood pressure of hypertensive patients, because of its high potassium content. It helps in losing weight quickly, because of its high dietary fiber and low fat and cholesterol content. In the light of above facts, the authors have made a humble attempt to compile an up-to-date review article on Lagenaria siceraria covering its phytochemistry, pharmacological actions and folk medicinal uses.

  2. 27 CFR 4.26 - Estate bottled.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Estate bottled. 4.26 Section 4.26 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Standards of Identity for Wine § 4.26...

  3. 21 CFR 165.110 - Bottled water.

    Science.gov (United States)

    2010-04-01

    ... regulations (40 CFR part 143) are as follows: Contaminant Concentration in milligrams per liter Aluminum 0.2....C. 552(a) and 1 CFR part 51, or (7) Method 505—“Analysis of Organohalide Pesticides and Commercial... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bottled water. 165.110 Section 165.110 Food...

  4. Influence of Shear Viscosity of Quark-Gluon Plasma on Elliptic Flow in Ultrarelativistic Heavy-Ion Collisions

    International Nuclear Information System (INIS)

    We investigate the influence of a temperature-dependent shear viscosity over entropy density ratio η/s on the transverse momentum spectra and elliptic flow of hadrons in ultrarelativistic heavy-ion collisions. We find that the elliptic flow in √(sNN)=200 GeV Au+Au collisions at RHIC is dominated by the viscosity in the hadronic phase and in the phase transition region, but largely insensitive to the viscosity of the quark-gluon plasma (QGP). At the highest LHC energy, the elliptic flow becomes sensitive to the QGP viscosity and insensitive to the hadronic viscosity.

  5. Methods for evaluating hermetic closures for screw-capped bottles.

    Science.gov (United States)

    Cilento, R D

    1977-03-01

    With the described method, a large number of sealed bottles can be tested to determine their effectiveness, integrity, and reliability in preserving an inert atmosphere. The method consists of placing milligram quantities of dry ice into the bottles, capping them, and periodically weighing them on an analytical balance; leaky bottles are detected by a loss in weight. This method can be applied to test a large number of bottles with a minimum of effort and manpower and without complicated instrumentation. The data presented are highly reproducible and correlate well with data from other methods and with the physical defects of the bottles. PMID:845797

  6. Effect of helium plasma gas flow rate on the properties of WC-12 wt.%Co coatings sprayed by atmospheric plasma

    Directory of Open Access Journals (Sweden)

    Mihailo R. Mrdak

    2014-06-01

    Full Text Available The cermet coatings of WC-12wt.%Co are extensively used to improve the wear resistance of a wide range of technical components. This paper analyses the influence of the plasma gas flow of helium on the microstructure and mechanical properties of WC-12wt.%Co coatings deposited by plasma spraying at atmospheric pressure (APS. In order to obtain homogeneous and denser coatings, three different flows of He ( 8 l/min., 16 l/min. and 32 l/min were used in the research. With the application of He, coatings achieved higher values of hardness due to less degradation of the primary WC carbides. The main goal was to deposit dense and homogeneous layers of WC-12wt.%Co coatings with improved wear resistance for different applications. The test results of the microstructure of the layers were evaluated under a light microscope. The analysis of the microstructure and the mechanical properties of the deposited layers was made in accordance with the standard of Pratt-Whitney. The morphology of the powder particles and the microstructure of the best coating was examined on the SEM (scanning electron microscope. The evaluation of the mechanical properties of the layers was done by applying the HV0.3 method for microhardness testing and by applying tensile testing to test the bond strength. The research has shown that the flow of He plasma gas significantly affects the microstructure, the mechanical properties and the structure of WC-12 wt.%Co coatings.

  7. Influence of Gas Flow Rate on Mixing of Argon with Air in Thermal Plasma Jets

    Czech Academy of Sciences Publication Activity Database

    Gonzalez, J. J.; Gleizes, A.; Freton, P.; Hlína, Jan; Šlechta, Jiří

    2002-01-01

    Roč. 52, - (2002), s. D842-D849. ISSN 0011-4626. [Symposium on Plasma Physics and Technology SPPT 2002 /20./. Prague, 10.06.2002-13.06.2002] R&D Projects: GA AV ČR IAA1057202 Keywords : plasma jet * thermal plasma * temperature field Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.311, year: 2002

  8. Ion focusing and interaction potential for spherical and rodlike obstacles in a supersonic plasma flow: numerical simulations

    International Nuclear Information System (INIS)

    The parameter dependence of the ion focus behind perfectly conducting or alternatively perfectly insulating spherical grains for different electron to ion temperature ratios is studied. For elongated, insulating dust grains we study the potential and plasma density wakes in drifting plasma for rods or plates of different lengths and different inclination angles. These two characteristics (i.e., the rod length and the inclination angle are important for the exact charge distribution on the surface and the wake pattern. For this case we discuss also the interaction potential between two elongated grains in a flowing plasma.Our simulations are carried out in two spatial dimensions by a Particle-in-Cell code, treating ions and electrons as individual particles. These studies can be relevant for finite size dust grains suspended in a plasma sheath or larger objects in space, e.g., meteoroids.

  9. Modelling and simulation of particle acceleration by a plasma flow in a discharge capillary-ablative pipe system

    Energy Technology Data Exchange (ETDEWEB)

    Zoler, D. [Tel Aviv Univ. (Israel); Kaplan, Z.; Ashkenazy, J. [SOREQ, Yavne (Israel)

    1995-12-31

    In a recent paper, the discharge capillary - ablative pipe system was proposed as a device able to provide high density high temperature plasmas. In such a device the plasma is produced in the discharge section (the capillary) and continues to evolve through its interaction with the walls of the ablative pipe representing the second section of the installation. Using the consistent model developed for the plasma flow in such a kind of discharges, it was proved that, by changing the level of the input electrical energy or, alternatively, by simple modifications of the system geometry we can obtain plasmas with an extended range of hydrodynamic and thermodynamic parameters. Due to this feature of the capillary-pipe systems, it could find uses in many applications. In the present work we show that the capillary-pipe system can also be an efficient device for accelerating clusters of small particles in the mass range of a few micrograms each to large velocities.

  10. Modelling and simulation of particle acceleration by a plasma flow in a discharge capillary-ablative pipe system

    International Nuclear Information System (INIS)

    In a recent paper, the discharge capillary - ablative pipe system was proposed as a device able to provide high density high temperature plasmas. In such a device the plasma is produced in the discharge section (the capillary) and continues to evolve through its interaction with the walls of the ablative pipe representing the second section of the installation. Using the consistent model developed for the plasma flow in such a kind of discharges, it was proved that, by changing the level of the input electrical energy or, alternatively, by simple modifications of the system geometry we can obtain plasmas with an extended range of hydrodynamic and thermodynamic parameters. Due to this feature of the capillary-pipe systems, it could find uses in many applications. In the present work we show that the capillary-pipe system can also be an efficient device for accelerating clusters of small particles in the mass range of a few micrograms each to large velocities

  11. Modeling, fabrication and plasma actuator coupling of flexible pressure sensors for flow separation detection and control in aeronautical applications

    Science.gov (United States)

    Francioso, L.; De Pascali, C.; Pescini, E.; De Giorgi, M. G.; Siciliano, P.

    2016-06-01

    Preventing the flow separation could enhance the performance of propulsion systems and future civil aircraft. To this end, a fast detection of boundary layer separation is mandatory for a sustainable and successful application of active flow control devices, such as plasma actuators. The present work reports on the design, fabrication and functional tests of low-cost capacitive pressure sensors coupled with dielectric barrier discharge (DBD) plasma actuators to detect and then control flow separation. Finite element method (FEM) simulations were used to obtain information on the deflection and the stress distribution in different-shaped floating membranes. The sensor sensitivity as a function of the pressure load was also calculated by experimental tests. The results of the calibration of different capacitive pressure sensors are reported in this work, together with functional tests in a wind tunnel equipped with a curved wall plate on which a DBD plasma actuator was mounted to control the flow separation. The flow behavior was experimentally investigated by particle image velocimetry (PIV) measurements. Statistical and spectral analysis, applied to the output signals of the pressure sensor placed downstream of the profile leading edge, demonstrated that the sensor is able to discriminate different ionic wind velocity and turbulence conditions. The sensor sensitivity in the 0–100 Pa range was experimentally measured and it ranged between 0.0030 and 0.0046 pF Pa‑1 for the best devices.

  12. Investigation of the Flow Structure on a Flat Plate Induced by Unsteady Plasma Actuation with DNS Methods

    Science.gov (United States)

    Yu, Jianyang; Chen, Fu; Liu, Huaping; Song, Yanping

    2015-12-01

    An investigation into the flow characteristic on a flat plate induced by an unsteady plasma was conducted with the methods of direct numerical simulations (DNS). A simplified model of dielectric barrier discharge (DBD) plasma was applied and its parameters were calibrated with the experimental results. In the simulations, effects of the actuation frequency on the flow were examined. The instantaneous flow parameters were also drawn to serve as a detailed study on the behavior when the plasma actuator was applied to the flow. The result shows that induced by the unsteady actuation, a series of vortex pairs which showed dipole formation and periodicity distribution were formed in the boundary layer. The production of these vortex pairs indicated a strong energy exchange between the main flow and the boundary layer. They moved downstream under the action of the free stream and decayed under the influence of the fluid viscosity. The distance of the neighboring vortices was found to be determined by the actuation frequency. Interaction of the neighboring vortices would be ignored when the actuation frequency was too small to make a difference. supported by the Foundation for Innovative Research Groups of National Natural Science Foundation of China (No. 51121004) and National Natural Science Foundation of China (No. 50976026)

  13. Investigation of Toroidal Flow Effects on L-H transition in Tokamak Plasma Based on Bifurcation Model

    International Nuclear Information System (INIS)

    This work aims to study effects of toroidal flow on the L-H transition phenomenon in tokamak plasmas using bifurcation concept. Two-field (thermal and particle) transport equations with both neoclassical and turbulent effects included are solved simultaneously. The transport suppression mechanism used in this work is flow shear, which is assumed to affect only the turbulent transport. The flow shear can be calculated from the force balance equation with toroidal flow as a main contributor. The toroidal velocity profile is calculated using three different models. The first model is an empirical model in which the velocity is dependent on local ion temperature. The second model is based on neoclassical toroidal viscosity theory in which the velocity is driven by ion temperature gradient. In the third model, the velocity is dependent on current density flow in plasma. The two transport equations are solved both analytically and numerically using MATLAB to study the criteria for H-mode formation, pedestal width and its dynamics. The results from three toroidal velocity models are compared and analyzed with respect to bifurcation behavior and plasma performance.

  14. Study on aggregation behavior of low density lipoprotein in hen egg yolk plasma by asymmetrical flow field-flow fractionation coupled with multiple detectors.

    Science.gov (United States)

    Dou, Haiyang; Magnusson, Emma; Choi, Jaeyeong; Duan, Fei; Nilsson, Lars; Lee, Seungho

    2016-02-01

    In this study, asymmetrical flow field-flow fractionation (AF4) coupled online with UV, multiangle light scattering (MALS), and fluorescence (FS) detectors (AF4-UV-MALS-FS) was employed for separation and characterization of egg yolk plasma. AF4 provided separation of three major components of the egg yolk plasma i.e. soluble proteins, low density lipoproteins (LDL) and their aggregates, based on their respective hydrodynamic sizes. Identification of LDL was confirmed by staining the sample with a fluorescent dye, Nile Red. The effect of carrier liquids on aggregation of LDL was investigated. Collected fractions of soluble proteins were characterized using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Moreover, the effect of heat and enzymatic treatment on egg yolk plasma was investigated. The results suggest that enzymatic treatment with phospholipase A2 (PLA2) significantly enhances the heat stability of LDL. The results show that AF4-UV-MALS-FS is a powerful tool for the fractionation and characterization of egg yolk plasma components. PMID:26304341

  15. Management of complex data flows in the ASDEX Upgrade plasma control system

    International Nuclear Information System (INIS)

    Highlights: ► Control system architectures with data-driven workflows are efficient, flexible and maintainable. ► Signal groups provide coherence of interrelated signals and increase the efficiency of process synchronisation. ► Sample tags indicating sample quality form the fundament of a local event handling strategy. ► A self-organising workflow benefits from sample tags consisting of time stamp and stream activity. - Abstract: Establishing adequate technical and physical boundary conditions for a sustained nuclear fusion reaction is a challenging task. Phased feedback control and monitoring for heating, fuelling and magnetic shaping is mandatory, especially for fusion devices aiming at high performance plasmas. Technical and physical interrelations require close collaboration of many components in sequential as well as in parallel processing flows. Moreover, handling of asynchronous, off-normal events has become a key element of modern plasma performance optimisation and machine protection recipes. The manifoldness of plasma states and events, the variety of plant system operation states and the diversity in diagnostic data sampling rates can hardly be mastered with a rigid control scheme. Rather, an adaptive system topology in combination with sophisticated synchronisation and process scheduling mechanisms is suited for such an environment. Moreover, the system is subject to real-time control constraints: response times must be deterministic and adequately short. Therefore, the experimental tokamak device ASDEX Upgrade employs a discharge control system DCS, whose core has been designed to meet these requirements. In the paper we will compare the scheduling schemes for the parallelised realisation of a control workflow and show the advantage of a data-driven workflow over a managed workflow. The data-driven workflow as used in DCS is based on signals connecting process outputs and inputs. These are implemented as real-time streams of data samples

  16. Gene expression responses of HeLa cells to chemical species generated by an atmospheric plasma flow

    International Nuclear Information System (INIS)

    Highlights: • Response of HeLa cells to a plasma-irradiated medium was revealed by DNA microarray. • Gene expression pattern was basically different from that in a H2O2-added medium. • Prominently up-/down-regulated genes were partly shared by the two media. • Gene ontology analysis showed both similar and different responses in the two media. • Candidate genes involved in response to ROS were detected in each medium. - Abstract: Plasma irradiation generates many factors able to affect the cellular condition, and this feature has been studied for its application in the field of medicine. We previously reported that hydrogen peroxide (H2O2) was the major cause of HeLa cell death among the chemical species generated by high level irradiation of a culture medium by atmospheric plasma. To assess the effect of plasma-induced factors on the response of live cells, HeLa cells were exposed to a medium irradiated by a non-lethal plasma flow level, and their gene expression was broadly analyzed by DNA microarray in comparison with that in a corresponding concentration of 51 μM H2O2. As a result, though the cell viability was sufficiently maintained at more than 90% in both cases, the plasma-medium had a greater impact on it than the H2O2-medium. Hierarchical clustering analysis revealed fundamentally different cellular responses between these two media. A larger population of genes was upregulated in the plasma-medium, whereas genes were downregulated in the H2O2-medium. However, a part of the genes that showed prominent differential expression was shared by them, including an immediate early gene ID2. In gene ontology analysis of upregulated genes, the plasma-medium showed more diverse ontologies than the H2O2-medium, whereas ontologies such as “response to stimulus” were common, and several genes corresponded to “response to reactive oxygen species.” Genes of AP-1 proteins, e.g., JUN and FOS, were detected and notably elevated in the plasma-medium. These

  17. Atmospheric Pressure Plasma Jet in Organic Solution: Spectra, Degradation Effects of Solution Flow Rate and Initial pH Value

    Science.gov (United States)

    Chen, Bingyan; Zhu, Changping; Chen, Longwei; Fei, Juntao; Gao, Ying; Wen, Wen; Shan, Minglei; Ren, Zhaoxing

    2014-12-01

    The organic compounds of p-nitrophenol (PNP) solution was treated by the active species generated in a stirred reactor by an atmospheric pressure plasma jet (APPJ). The emission intensities of hydroxyl (OH), oxygen (O), nitric oxide (NO), hydrogen (H) and molecular (N2) were measured by optical emission spectroscopy (OES). The relations between the flow rates of the PNP solution and degradation, the degradation effects and initial pH value of the solution were also investigated. Experimental results show that there exist intense emissions of O (777.1 nm), N2 (337.1 nm), OH (306-310 nm) and NO band (200-290 nm) in the region of plasma. Given the treatment time and gas flow rate, the degradation increased as a function of discharge energy and solution flow rate, respectively. The solution flow rate for the most efficient degradation ranged from 1.414 m/s to 1.702 m/s, and contributed very little when it exceeded 2.199 m/s. This indicates the existence of diffusion-controlled reactions at a low solution flow rate and activation-controlled reactions at a high solution flow rate. Moreover, increasing or decreasing the initial pH value of neutral PNP solution (pH=5.95) could improve the degradation efficiency. Treated by APPJ, the PNP solutions with different initial pH values of 5.95, 7.47 and 2.78 turned more acidic in the end, while the neutral solution had the lowest degradation efficiency. This work clearly demonstrates the close coupling of active species, photolysis of ultraviolet, the organic solution flow rate and the initial pH value, and thus is helpful in the study of the mechanism and application of plasma in wastewater treatment.

  18. Analytical performance of a low-gas-flow torch optimized for inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Montaser, A.; Huse, G.R.; Wax, R.A.; Chan, S.-K.; Golightly, D.W.; Kane, J.S.; Dorrzapf, A.F., Jr.

    1984-01-01

    An inductively coupled Ar plasma (ICP), generated in a lowflow torch, was investigated by the simplex optimization technique for simultaneous, multielement, atomic emission spectrometry (AES). The variables studied included forward power, observation height, gas flow (outer, intermediate, and nebulizer carrier) and sample uptake rate. When the ICP was operated at 720-W forward power with a total gas flow of 5 L/min, the signal-to-background ratios (S/B) of spectral lines from 20 elements were either comparable or inferior, by a factor ranging from 1.5 to 2, to the results obtained from a conventional Ar ICP. Matrix effect studies on the Ca-PO4 system revealed that the plasma generated in the low-flow torch was as free of vaporizatton-atomizatton interferences as the conventional ICP, but easily ionizable elements produced a greater level of suppression or enhancement effects which could be reduced at higher forward powers. Electron number densities, as determined via the series until line merging technique, were tower ht the plasma sustained in the low-flow torch as compared with the conventional ICP. ?? 1984 American Chemical Society.

  19. Balancing incident heat and ion flow for process optimization in plasma based ion implantation

    International Nuclear Information System (INIS)

    Plasma based ion implantation at elevated temperatures is a technology often used to obtain thick surface layers of several μm by thermally activated diffusion, e.g. nitrogen in steel, titanium or aluminium. By lowering the pulse voltage at constant temperature, the current density can be increased at a constant heat flow. However, an upper limit is given by the ratio of the diffusion rate transporting the implanted ions from the surface towards the bulk and the sputter yield. This sputtering of the surface dominates for very high current densities and limits the maximum achievable layer thickness. Different maximum current densities were found for the four investigated systems - nitrogen in different steel grades, aluminium and titanium, as well as oxygen in titanium - reflecting the varying diffusivities. Additional requirements, besides the maximum current density, as a conformal treatment for complex objects containing small holes or trenches, as well as short heating times, can be solved most effectively by pulsed voltages in the range of 2-5 kV and an additional heating of the sample. The problem of a sample cooling time of several hours after the treatment is recognized. A partial solution would be to increase the gas pressure during the cooling phase for a more effective heat dissipation. (author)

  20. Relationship between cardiac output and effective renal plasma flow in patients with cardiac disease

    Energy Technology Data Exchange (ETDEWEB)

    McGriffin, D.; Tauxe, W.N.; Lewis, C.; Karp, R.; Mantle, J.

    1984-12-01

    The relationship between effective renal plasma flow (ERPF) and cardiac output was examined in 46 patients (22 with congestive heart failure and 24 following cardiac surgical procedures) by simultaneously measuring the global ERPF by the single-injection method and cardiac output by the thermodilution method. Of the patients in the heart-failure group, 21 also had pulmonary artery end diastolic pressure (PAEDP) recorded at the same time. ERPF and cardiac output were found to be related by the regression equations: cardiac output = 2.08 + 0.0065 ERPF (r, 080), with a SE of estimate of 0.81 l/min. ERPF and PAEDP were related by the regression equation: PAEDP = 42.02 - 0.0675 ERPF (r, 0.86), with a SE of estimate of 5.5 mm Hg. ERPF may be a useful noninvasive method of estimating cardiac output if it is known that no intrinsic kidney disease is present, and if the error of 0.81 l/min (1 SE of estimate) is within the range of clinical usefulness. The error is principally attributable to the determination of cardiac output by the thermodilution method.

  1. Using the developed cross-flow filtration chip for collecting blood plasma under high flow rate condition and applying the immunoglobulin E detection

    International Nuclear Information System (INIS)

    This paper presents a cross-flow filtration chip for separating blood cells (white blood cells, red blood cells, and platelets) and obtaining blood plasma from human blood. Our strategy is to flow the sample solution in parallel to the membrane, which can generate a parallel shear stress to remove the clogging microparticles on the membrane, so the pure sample solution is obtained in the reservoir. The cross-flow filtration chip includes a cross-flow layer, a Ni-Pd alloy micro-porous membrane, and a reservoir layer. The three layers are packaged in a polymethylmethacrylate (PMMA) frame to create the cross-flow filtration chip. Various dilutions of the blood sample (original, 2 × , 3 × , 5 × , and 10×), pore sizes with different diameters (1 µm, 2 µm, 4 µm, 7 µm, and 10 µm), and different flow rates (1 mL/min, 3 mL/min, 5 mL/min, 7 mL/min, and 10 mL/min) are tested to determine their effects on filtration percentage. The best filtration percentage is 96.2% when the dilution of the blood sample is 10 × , the diameter of pore size of a Ni-Pd alloy micro-porous membrane is 2 µm, and the flow rate is 10 mL/min. Finally, for the clinical tests of the immunoglobulin E (IgE) concentration, the cross-flow filtration chip is used to filter the blood of the allergy patients to obtain the blood plasma. This filtered blood plasma is compared with that obtained using the conventional centrifugation based on the enzyme-linked immunosorbent assay. The results reveal that these two blood separation methods have similar detection trends. The proposed filtration chip has the advantages of low cost, short filtration time, and easy operation and thus can be applied to the separation of microparticles, cells, bacteria, and blood. (paper)

  2. Hydrodynamic instability of thermal plasma flow generated by a hybrid steam-argon torch

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Vladimír; Hrabovský, Milan

    Grenoble: CMRS, 2002 - (Sadeghi, N.; Sugai, H.), s. 259-260 [European Conference on Atomic and Molecular Physics of Ionized Gases and 5th International Conference on Reactive Plasmas/16th./. Grenoble (FR), 14.07.2002-18.07.2002] R&D Projects: GA AV ČR IAA1057202 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma, thermal plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  3. Research on bottom detection in Intelligent Empty Bottle Inspection System

    Directory of Open Access Journals (Sweden)

    Bin Huang

    2013-10-01

    Full Text Available Intelligent empty bottle inspection system is an important inspection equipment of empty bottle before filling beer, and it is a blend of machine vision, precision machine and real-time control. They need to cooperate perfectly to achieve the desired effect. In the design of the empty bottle inspection system, one of the key technologies is the bottle bottom detection which affects the speed and accuracy of the system. It includes positioning and defect recognition of bottle bottom. For the problems such as the slow detection speed and low detection precision of bottle bottom detection, some new methods are proposed in this paper. The positioning algorithm of the bottle bottom in images is studied after preprocessing the obtained images, and the accurate positioning is achieved by improving the Randomized Hough transform. In the defect recognition of bottle bottom, a method of calculating optimum radius in Fourier spectrum is used to solve the problem of the detection accuracy being influenced by the antiskid veins of bottle bottom. It can improve the recognition accuracy effectively. Experiments show the methods proposed in this paper can effectively improve the precision and speed of the bottle bottom detection.

  4. Planned upgrade to the coaxial plasma source facility for high heat flux plasma flows relevant to tokamak disruption simulations

    International Nuclear Information System (INIS)

    Plasma disruptions in tokamaks remain serious obstacles to the demonstration of economical fusion power. In disruption simulation experiments, some important effects have not been taken into account. Present disruption simulation experimental data do not include effects of the high magnetic fields expected near the PFCs in a tokamak major disruption. In addition, temporal and spatial scales are much too short in present simulation devices to be of direct relevance to tokamak disruptions. To address some of these inadequacies, an experimental program is planned at North Carolina State University employing an upgrade to the Coaxial Plasma Source (CPS-1) magnetized coaxial plasma gun facility. The advantages of the CPS-1 plasma source over present disruption simulation devices include the ability to irradiate large material samples at extremely high areal energy densities, and the ability to perform these material studies in the presence of a high magnetic field. Other tokamak disruption relevant features of CPS-1U include a high ion temperature, high electron temperature, and long pulse length

  5. Black holes with bottle-shaped horizons

    CERN Document Server

    Chen, Yu

    2016-01-01

    We present a new class of four-dimensional AdS black holes with non-compact event horizons of finite area. The event horizons are topologically spheres with one puncture, with the puncture pushed to infinity in the form of a cusp. Because of the shape of their event horizons, we call such black holes "black bottles". The solution was obtained as a special case of the Plebanski-Demianski solution, and may describe either static or rotating black bottles. For certain ranges of parameters, an acceleration horizon may also appear in the space-time. We study the full parameter space of the solution, and the various limiting cases that arise. In particular, we show how the rotating black hole recently discovered by Klemm arises as a special limit.

  6. Effects of gas flow on oxidation reaction in liquid induced by He/O{sub 2} plasma-jet irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Atsushi; Uchida, Giichiro, E-mail: uchida@jwri.osaka-u.ac.jp; Takenaka, Kosuke; Setsuhara, Yuichi [Joining and Welding Research Institute, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Kawasaki, Toshiyuki [Department of Mechanical and Electrical Engineering, Nippon Bunri University, Oita, Oita 870-0397 (Japan); Koga, Kazunori; Sarinont, Thapanut; Amano, Takaaki; Shiratani, Masaharu [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Fukuoka 819-0395 (Japan)

    2015-07-28

    We present here analysis of oxidation reaction in liquid by a plasma-jet irradiation under various gas flow patterns such as laminar and turbulence flows. To estimate the total amount of oxidation reaction induced by reactive oxygen species (ROS) in liquid, we employ a KI-starch solution system, where the absorbance of the KI-starch solution near 600 nm behaves linear to the total amount of oxidation reaction in liquid. The laminar flow with higher gas velocity induces an increase in the ROS distribution area on the liquid surface, which results in a large amount of oxidation reaction in liquid. However, a much faster gas flow conversely results in a reduction in the total amount of oxidation reaction in liquid under the following two conditions: first condition is that the turbulence flow is triggered in a gas flow channel at a high Reynolds number of gas flow, which leads to a marked change of the spatial distribution of the ROS concentration in gas phase. Second condition is that the dimpled liquid surface is formed by strong gas flow, which prevents the ROS from being transported in radial direction along the liquid surface.

  7. Using recycled polyethylene terephthalate (PET) in the production of bottle trays

    OpenAIRE

    Salminen, Pontus

    2013-01-01

    This thesis was commissioned by K.Hartwall Oy and it investigates the possibility of manufacturing a bottle tray out of recycled polyethylene terephthalate (PET). Until now the tray has been produced out of high density polyethylene (HDPE) through injection moulding. The main concern was that the flow properties of PET would be too poor in order to produce trays with injection moulding. The literature that was reviewed does however suggest that PET has low viscosity. Therefore one of the main...

  8. Orbital myiasis caused by green bottle fly

    OpenAIRE

    Misra, Neeta; Gogri, Pratik; Misra, Somen; Singh, Anil; Ingale, Ashish

    2013-01-01

    An 80-year-old farmer, presented with large, maggot infested ulceration involving the medial part of the right upper lid. The left eye was phthisical. There was history of untreated traumatic laceration of the right upper lid. Mechanical removal of maggots was done under turpentine coverage with regular antibiotic dressing. Microbiological examination of maggots revealed the larvae to be of Lucilia sericata (green bottle fly). The ulceration completely healed in two weeks following manual rem...

  9. Experimental Investigation of the Role of Fluid Turbulent Stresses and Edge Plasma Flows for Intrinsic Rotation Generation in DIII-D H-Mode Plasmas

    International Nuclear Information System (INIS)

    The first measurements of turbulent stresses and flows inside the separatrix of a tokamak H-mode plasma are reported, using a reciprocating multitip Langmuir probe at the DIII-D tokamak. A strong co-current rotation layer at the separatrix is found to precede intrinsic rotation development in the core. The measured fluid turbulent stresses transport toroidal momentum outward against the velocity gradient and thus try to sustain the edge layer. However, large kinetic stresses must exist to explain the net inward momentum transport leading to co-current core plasma rotation. The importance of such kinetic stresses is corroborated by the success of a simple orbit loss model, representing a purely kinetic mechanism, in the prediction of features of the edge corotation layer.

  10. Recall campaign for gas bottles and banks

    CERN Multimedia

    2015-01-01

    The previous contract with gas supplier Carbagas ended on 31 March 2015. Gas bottles and banks are not a property of CERN. According to the contract terms, they can remain on CERN sites without any extra costs until 30 September 2015.    If you are using Carbagas containers (bottles and/or banks) for gas purchased between 1 April 2010 and 31 March 2015, multiple options exist: Return them to the closest gas point. Purchase them on the following basis:     Rent them on the following basis: 12 CHF/month for bottles, 144 CHF/month for banks. The recall campaign has been going on for several months already: we would like to thank everyone who has already replied to it. If you haven’t answered yet, there is still time. If you know of unused or abandoned Carbagas containers, please don’t hesitate to contact us. Thank you i...

  11. Horizontal plasma flow velocities in the ionosphere of Mars - A test case for the solar wind interaction

    Science.gov (United States)

    Singhal, R. P.; Whitten, R. C.

    1988-01-01

    On the apparently nonmagnetic planets Mars and Venus, ionospheric plasma can be driven from the day to the nightside by two different mechanisms: (1) the pressure gradient force across the terminator, and (2) a solar wind-induced force via a viscous boundary layer interaction. Calculations of the horizontal flow velocities in the ionosphere of Mars using the two mechanisms produce results differing by an order of magnitude. It is pointed out that the detailed observations of the horizontal flow velocity in the ionosphere of Mars may provide a test case for the resolution of some problems relating to the interaction of the solar wind with the planets Mars and Venus.

  12. Suppression of drift wave turbulence and zonal flow formation by changing axial boundary conditions in a cylindrical magnetized plasma device

    International Nuclear Information System (INIS)

    For drift wave turbulence, due to charge conservation, the divergence of the parallel current is coupled to the divergence of the perpendicular polarization current, which determines the effective radial momentum flux, i.e., the Reynolds stress. Changes in the current flow patterns also affect the nonlinear energy transfer from smaller to larger scales. Here, we show that by changing the end plate boundary conditions in a cylindrical plasma device, the radial currents through the plasma and hence the net momentum transport and the nonlinear coupling for the inverse energy transfer are strongly modified. The transition to drift wave turbulence and the formation of low frequency zonal flows can be either suppressed with conducting boundaries or enhanced with insulating boundaries.

  13. Analysis of pion elliptic flows and HBT interferometry in a granular quark-gluon plasma droplet model

    CERN Document Server

    Zhang, W N; Wong, C Y; Zhang, Wei-Ning; Ren, Yan-Yu; Wong, Cheuk-Yin

    2006-01-01

    In many simulations of high-energy heavy-ion collisions on an event-by-event analysis, it is known that the initial energy density distribution in the transverse plane is highly fluctuating. Subsequent longitudinal expansion will lead to many longitudinal tubes of quark-gluon plasma which have tendencies to break up into many spherical droplets because of sausage instabilities. We are therefore motivated to use a model of quark-gluon plasma granular droplets that evolve hydrodynamically to investigate pion elliptic flows and Hanbury-Brown-Twiss interferometry. We find that the data of pion transverse momentum spectra, elliptic flows, and HBT radii in \\sqrt{s_{NN}}=200 GeV Au + Au collisions at RHIC can be described well by an expanding source of granular droplets with an anisotropic velocity distribution.

  14. Generation of sheared poloidal flows by electrostatic and magnetic Reynolds stress in the boundary plasma of HT-7 tokamak

    International Nuclear Information System (INIS)

    The radial profiles of electrostatic and magnetic Reynolds stress (Maxwell stress) have been measured in the plasma boundary region of HT-7 tokamak. Experimental results show that the radial gradient of electrostatic Reynolds stress (ERS) changes sign across the last closed flux surface, and the neoclassical flow damping and the damping due to charge exchange processes are balanced by the radial gradient of ERS, which sustains the equilibrium sheared flow structure in a steady state. The contribution of magnetic Reynolds stress was found unimportant in a low β plasma. Detailed analyses indicate that the propagation properties of turbulence in radial and poloidal directions and the profiles of potential fluctuation level are responsible for the radial structure of ERS. (author)

  15. Dissipated power and induced velocity fields data of a micro single dielectric barrier discharge plasma actuator for active flow control☆

    Science.gov (United States)

    Pescini, E.; Martínez, D.S.; De Giorgi, M.G.; Francioso, L.; Ficarella, A.

    2015-01-01

    In recent years, single dielectric barrier discharge (SDBD) plasma actuators have gained great interest among all the active flow control devices typically employed in aerospace and turbomachinery applications [1,2]. Compared with the macro SDBDs, the micro single dielectric barrier discharge (MSDBD) actuators showed a higher efficiency in conversion of input electrical power to delivered mechanical power [3,4]. This article provides data regarding the performances of a MSDBD plasma actuator [5,6]. The power dissipation values [5] and the experimental and numerical induced velocity fields [6] are provided. The present data support and enrich the research article entitled “Optimization of micro single dielectric barrier discharge plasma actuator models based on experimental velocity and body force fields” by Pescini et al. [6]. PMID:26425667

  16. Elimination of Numerical Cherenkov Instability in flowing-plasma Particle-In-Cell simulations by using Galilean coordinates

    CERN Document Server

    Lehe, Remi; Godfrey, Brendan B; Maier, Andreas R; Vay, Jean-Luc

    2016-01-01

    Particle-In-Cell (PIC) simulations of relativistic flowing plasmas are of key interest to several fields of physics (including e.g. laser-wakefield acceleration, when viewed in a Lorentz-boosted frame), but remain sometimes infeasible due to the well-known numerical Cherenkov instability (NCI). In this article, we show that, for a plasma drifting at a uniform relativistic velocity, the NCI can be eliminated by simply integrating the PIC equations in Galilean coordinates that follow the plasma (also sometimes known as comoving coordinates) within a spectral analytical framework. The elimination of the NCI is verified empirically and confirmed by a theoretical analysis of the instability. Moreover, it is shown that this method is applicable both to Cartesian geometry and to cylindrical geometry with azimuthal Fourier decomposition.

  17. Investigation of electron and ion flows in the microsecond plasma opening switch on the terawatt power level

    International Nuclear Information System (INIS)

    The results of an investigation of ion and electron flows in the coaxial microsecond plasma opening switch (POS) at generator GIT-4 are given. The 1 mks front duration POS with outer and inner electrodes of 210 mm and 75 mm diameters respectively switched 1 MA pulse during 0.1 mks to the short circuited coaxial line with the same diameters and 120 cm of length. The polarity of the inner electrode was negative. The plasma of the POS was injected from outer electrode by 32 plasma guns of capillary type. The typical POS voltage was 0.9-1.2 MV. The calculated energy losses in the POS during the switching phase reached (0.1-0.15) MJ. The calorimetric measurements of the energy dissipated on both electrodes gave the same value. The location and distribution of the head absorbed along the POS electrodes were determined

  18. Improvement of the Performance of Graphite Felt Electrodes for Vanadium-Redox-Flow-Batteries by Plasma Treatment

    OpenAIRE

    Eva-Maria Hammer; Benedikt Berger; Lidiya Komsiyska

    2014-01-01

    In the frame of the present contribution oxidizing plasma pretreatment is used for the improvement of the electrocatalytic activity of graphite felt electrodes for Vanadium-Redox-Flow-Batteries (VRB). The influence of the working gas media on the catalytic activity and the surface morphology is demonstrated. The electrocatalytical properties of the graphite felt electrodes were examined by cyclic voltammetry and electrochemical impedance spectroscopy. The obtained results show that a signific...

  19. Ion cyclotron range of frequency mode conversion flow drive in D(He-3) plasmas on JET

    NARCIS (Netherlands)

    Lin, Y.; Mantica, P.; Hellsten, T.; Kiptily, V.; Lerche, E.; Nave, M. F. F.; Rice, J. E.; Van Eester, D.; de Vries, P. C.; Felton, R.; Giroud, C.; Tala, T.

    2012-01-01

    Ion cyclotron range of frequency (ICRF) mode conversion has been shown to drive toroidal flow in JET D(He-3) L-mode plasmas: B-t0 = 3.45 T, n(e0) similar to 3x10(19) m(-3), I-p = 2.8 and 1.8 MA, P-RF <= 3MW at 33MHz and -90 degrees phasing. Central toroidal rotation in the counter-I-p directi

  20. An experimental research to study the microwaves transmission characteristics of ablating material in arc-heated plasma flow

    International Nuclear Information System (INIS)

    An experimental research about the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The results show that the ablating material with accidented surface and its high temperature have remarkably affected the reflection and the transmission of microwaves. The experiment proves that the system has outstanding precision and reliability

  1. Phase composition of WC-TiC-Co hard alloy with zirconium coating after treatment by compressive plasma flows

    International Nuclear Information System (INIS)

    In this work influence of treatment parameters by compressive plasma flows (CPF) (energy density (34, 41 J/cm2), pulse number (1 and 5), nitrogen pressure in chamber (3 and 10 Torr)) on phase composition of hard alloy with zirconium coating was studied. It was established that CPF irradiation with mentioned parameters in nitrogen atmosphere allows to form alloying with zirconium (Ti,Zr,W)C solid solution and ZrN nitride phase in the system surface layer. (authors)

  2. Temporally resolved ozone distribution of a time modulated RF atmospheric pressure argon plasma jet: flow, chemical reaction, and transient vortex

    Science.gov (United States)

    Zhang, S.; Sobota, A.; van Veldhuizen, E. M.; Bruggeman, P. J.

    2015-08-01

    The ozone density distribution in the effluent of a time modulated RF atmospheric pressure plasma jet (APPJ) is investigated by time and spatially resolved by UV absorption spectroscopy. The plasma jet is operated with an averaged dissipated power of 6.5 W and gas flow rate 2 slm argon  +2% O2. The modulation frequency of the RF power is 50 Hz with a duty cycle of 50%. To investigate the production and destruction mechanism of ozone in the plasma effluent, the atomic oxygen and gas temperature is also obtained by TALIF and Rayleigh scattering, respectively. A temporal increase in ozone density is observed close to the quartz tube exit when the plasma is switched off due to the decrease in O density and gas temperature. Ozone absorption at different axial positions indicates that the ozone distribution is dominated by the convection induced by the gas flow and allows estimating the on-axis local gas velocity in the jet effluent. Transient vortex structures occurring during the switch on and off of the RF power also significantly affect the ozone density in the far effluent.

  3. Ocular injuries from carbonated soft drink bottle explosions.

    OpenAIRE

    Al Salem, M; Sheriff, S M

    1984-01-01

    Sixteen cases of ocular injuries serious enough to require admission to Ibn-Sina Hospital, Kuwait, Arabian Gulf, due to explosion of glass bottles of carbonated soft drinks are reported over a period of 14 months from the beginning of July 1981 to the end of August 1982. Prevalence was much greater in the summer months and among children. Explosions of bottles without prior agitation occurred in 11 cases (68.7%). High environmental temperature and defective bottles were the most important pre...

  4. 21 CFR 880.6085 - Hot/cold water bottle.

    Science.gov (United States)

    2010-04-01

    ... Devices § 880.6085 Hot/cold water bottle. (a) Identification. A hot/cold water bottle is a device intended for medical purposes that is in the form of a container intended to be filled with hot or cold water... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hot/cold water bottle. 880.6085 Section...

  5. Measurement of split glomerular filtration rate, effective renal plasma flow, filtration fraction by fractional renal uptake

    International Nuclear Information System (INIS)

    The total and split glomerular filtration rate (GFR) was calculated from the previously reported formula of linear regression analysis between the renal uptake of Tc-99m DTPA within 2 to 3 minutes following the radionuclide appearance into the kidneys and sodium thiosulfate clearance, accordingly: GFR (ml/min) = 8.775 x (% total renal uptake) + 9.685. On the other hand, the total and split effective renal plasma flow (ERPF) was also determined by the modified Schlegel's method of fractional renal uptake of intravenously administered I-131 hippuran within 1 to 2 minutes following radionuclide appearance into the kidneys. After correcting the obtained renal uptake by depth and dose, the ERPF was computed from the significant correlation with paraaminohippuric acid (PAH) clearance (r = 0.867, ERPF = 17.2 x (% total renal uptake) + 49.7). And the total and split filtration fraction (FF) was determined by dividing the GFR with Tc-99m DTPA by the ERPF with I-131 hippuran. In the 24 patients without functional impairement of kidney, the split GFR, ERPF and FF of right kidney were 50.9 ± 9.5 ml/min, 209.1 ± 33.8 ml/min and 0.241 ± 0.037, and those of left kidney were 52.8 ± 10.5 ml/min, 214.2 ± 42.3 ml/min and 0.248 ± 0.034. In unilateral renal disease of 14 patients with obstructive uropathy and 9 patients with renovascular hypertension, the FF of the affected side did not show any significant changes compared to that of the unaffected side, and the alterations of GFR were well accorded with those of ERPF. Among three patients following the treatment of percutaneous transluminal angioplasty, however, some disparities between GFR and ERPF alterations were found in the affected side. (author)

  6. Enhanced nonlinear iterative techniques applied to a non-equilibrium plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Knoll, D.A.; McHugh, P.R. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1996-12-31

    We study the application of enhanced nonlinear iterative methods to the steady-state solution of a system of two-dimensional convection-diffusion-reaction partial differential equations that describe the partially-ionized plasma flow in the boundary layer of a tokamak fusion reactor. This system of equations is characterized by multiple time and spatial scales, and contains highly anisotropic transport coefficients due to a strong imposed magnetic field. We use Newton`s method to linearize the nonlinear system of equations resulting from an implicit, finite volume discretization of the governing partial differential equations, on a staggered Cartesian mesh. The resulting linear systems are neither symmetric nor positive definite, and are poorly conditioned. Preconditioned Krylov iterative techniques are employed to solve these linear systems. We investigate both a modified and a matrix-free Newton-Krylov implementation, with the goal of reducing CPU cost associated with the numerical formation of the Jacobian. A combination of a damped iteration, one-way multigrid and a pseudo-transient continuation technique are used to enhance global nonlinear convergence and CPU efficiency. GMRES is employed as the Krylov method with Incomplete Lower-Upper(ILU) factorization preconditioning. The goal is to construct a combination of nonlinear and linear iterative techniques for this complex physical problem that optimizes trade-offs between robustness, CPU time, memory requirements, and code complexity. It is shown that a one-way multigrid implementation provides significant CPU savings for fine grid calculations. Performance comparisons of the modified Newton-Krylov and matrix-free Newton-Krylov algorithms will be presented.

  7. Measurement of effective renal plasma flow (ERPF) with 123I-orthoiodohippurate

    International Nuclear Information System (INIS)

    In order to evaluate separate renal function, effective renal plasma flow (ERPF) was measured with 123I-orthoiodohippurate (OIH) and a scintillation camera interfaced to a computer. Fourty six patients (51 times) were studied following the Tauxe's method with an injection of 500 μCi 123I-OIH. On the posterior view, data were sequentially collected in 1-minute frame for 27 minutes on 64 x 64 matrix. The blood sample was drawn 44 minutes after injection and was counted using a scintillation counter. In order to calculate separate ERPF, each net renographic curve was integrated for 0-3 minutes after injection. Right and left integrals were expressed as percentage of the total counts. Separate ERPF was obtained by multiplying total ERPF with each resultant fraction. In order to quantify the retention of 123I-OIH in the renal cortex, cortex retention ratio (CRR) was defined from the following formula: CRR= C17/Csub(max) x 100%, where C17 is counts 17 minutes after injection and Csub(max) is the maximum counts in the cortex renogram. Results of ERPF were evaluated by comparing with each renogram pattern. Results obtained are as follows. 1) ERPF with 123I-OIH was well correlated to that with PAH (paraaminohippurate): r = 0.77 (p < 0.01), y = 0.87 x +65. 2) Separate ERPF can be validly utilized for the detection of unilateral renal disease. 3) Separate ERPF was more than 100 ml/min in the standard pattern and the delayed pattern on the conventional renogram, while less than 100 ml/min in the hypofunctional pattern. 4) Cortex retention ratio was less than 30% in the standard pattern, 20 to 60% in the delayed pattern, 60 to 100% in the hypofunctional pattern, and 100% in the obstructive pattern. Therefore, difference of the separate ERPF was recognized among the renogram patterns. (author)

  8. Microporous polytetrafluoroethylene tube separator for the determination of beryllium by flow injection - or suction-flow -solvent extraction followed by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    A dual-tube separator was constructed for the purpose of flow injection - or suction-flow-solvent extraction followed by inductively coupled plasma atomic emission spectrometry. It consisted of an inner microporous polytetrafluoroethylene (PTFE) tube (1 mm i.d., 10 cm long, porosity 70%) and an outer PTFE tube (3 mm i.d.). This system was used for the determination of beryllium in alloys by extraction as the acetylacetonate into carbon tetrachloride. The phase separation was complete at an organic flow-rate of 0.2-6.2 ml min-1 and an aqueous flow-rate of up to 6.2 ml min-1. With a sample volume of 0.5 ml (50 p.p.b. Be) and sample and organic flow-rates of 1.2 and 0.7 ml min-1, respectively, the relative standard deviation (n = 10) was 1.3% and the sampling rate was 25 h-1. The sensitivity was enhanced about 2.6-fold compared with that obtained by the direct nebulisation of an aqueous solution. (author)

  9. Cross-B convection of artificially created, negative-ion clouds and plasma depressions: Low-speed flow

    International Nuclear Information System (INIS)

    A negative-ion, positive-ion plasma produced by the release of an electron attachment chemical into the F region becomes electrically polarized by the collisions with neutrals moving across magnetic field lines. The resulting electric field causes E x B drift of the two ion species and the residual electrons. The cross-field flow of the modified ionosphere is computed using a two-dimensional numerical simulation which includes electron attachment and mutual neutralization chemistry, self-consistent electric fields, and three-species plasma transport. The velocity of the plasma is initially in the direction of the neutral wind because the negative-ion cloud is a Pedersen conductivity enhancement. As the positive and negative ions react, the Pedersen conductivity becomes depressed below the ambient value and the velocity of the plasma reverses direction. A plasma hole remains after the positive and negative ions have mutually neutralized. The E x B gradient drift instability produces irregularities on the upwind edge of the hole. These processes may be observed experimentally with optical and backscatter-radar diagnostics

  10. Energy balance and kinetics of gasification of biomass particles in thermal plasma flow

    Czech Academy of Sciences Publication Activity Database

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

    Bochum: University of Bochum, 2009, P3.16.05. ISBN 978-0-471-72001-0. [International Symposium on Plasma Chemistry/19th./. Bochum (DE), 26.07.2009-31.07.2009] R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * biomass * gasification * syngas Subject RIV: BL - Plasma and Gas Discharge Physics http://www.ispc-conference.org/ispcproc/papers/440.pdf

  11. Development of localized arc filament RF plasma actuators for high-speed and high Reynolds number flow control

    International Nuclear Information System (INIS)

    Recently developed localized arc filament plasma actuators (LAFPAs) have shown tremendous control authority in high-speed and high Reynolds number flow for mixing enhancement and noise mitigation. Previously, these actuators were powered by a high-voltage pulsed DC plasma generator with low energy coupling efficiency of 5-10%. In the present work, a new custom-designed 8-channel pulsed radio frequency (RF) plasma generator has been developed to power up to 8 plasma actuators operated over a wide range of forcing frequencies (up to 50 kHz) and duty cycles (1-50%), and at high energy coupling efficiency (up to 80-85%). This reduces input electrical power requirements by approximately an order of magnitude, down to 12 W per actuator operating at 10% duty cycle. The new pulsed RF plasma generator is scalable to a system with a large number of channels. Performance of pulsed RF plasma actuators used for flow control was studied in a Mach 0.9 circular jet with a Reynolds number of about 623,000 and compared with that of pulsed DC actuators. Eight actuators were distributed uniformly on the perimeter of a 2.54-cm diameter circular nozzle extension. Both types of actuators coupled approximately the same amount of power to the flow, but with drastically different electrical inputs to the power supplies. Particle image velocimetry measurements showed that jet centerline Mach number decay produced by DC and RF actuators operating at the same forcing frequencies and duty cycles is very similar. At a forcing Strouhal number near 0.3, close to the jet column instability frequency, well-organized periodic structures, with similar patterns and dimensions, were generated in the jets forced by both DC and RF actuators. Far-field acoustic measurements demonstrated similar trends in the overall sound pressure level (OASPL) change produced by both types of actuators, resulting in OASPL reduction up to 1.2-1.5 dB in both cases. We conclude that pulsed RF actuators demonstrate flow

  12. Low power cross-flow atmospheric pressure Ar+He plasma jet. Spectroscopic diagnostic and excitation capabilities

    International Nuclear Information System (INIS)

    Complete text of publication follows. Recently we have presented some considerations regarding a helium atmospheric pressure cross-flow plasma jet [S.D. Anghel et al., Nucl. Instr. and Methods in Phys. Research B, B267 (2009) 430-433]. The present work extends the study over this kind of plasma using argon (0.4 l min-1) as main plasma gas and adding helium (0-0.3 l min-1) as secondary gas. Before entering the generation zone, the argon passes through a nebulizing system (nebulizer + cyclonic chamber) and generates a wet aerosol. The nebulized liquid could be distilled water or analyte solution. Then, the aerosol is mixed with helium forming the plasma medium. For stabilizing the plasma jet a second electrode (grounded) was placed at a distance of 10 mm from the powered electrode. The plasma power can be modified in the range of 40-75 W. The spectroscopic diagnostic show that TexcAr = 3900-5000 K, TvibrN2 2700-3800 K, TrotOH 2200-3500 K, ne= 1013-1014 cm-3, function of working parameters. The plasma was tested as excitation source for emission spectrometry. Atomization and excitation capabilities were tested for six elements: Na, Li, K, Cd, Hg and Zn. In contrast with the other studies [K. Jankowsky et al., J. Anal. At. Spectrom., 22 (2007) 1076-1082], it was concluded that the addition of helium has a negative effect on the intensity of the analyte emission lines. From analytical point of view the optimum observation zone is located at a distance of 8 mm from the powered electrode where the higher signal to noise ratio was observed. The estimated detection limits for the studied elements are in the range of 15 ng ml-1 to 5 μg ml-1. This study was supported by National University Research Council, Ministry of Education, Research and Innovation, Romania, Grant IDEI, code 2270/2009.

  13. Two-dimensional magnetic field evolution measurements and plasma flow speed estimates from the coaxial thruster experiment

    International Nuclear Information System (INIS)

    Local, time-dependent magnetic field measurements have been made in the Los Alamos coaxial thruster experiment (CTX) [C. W. Barnes et al., Phys. Fluids B 2, 1871 (1990); J. C. Fernandez et al., Nucl. Fusion 28, 1555 (1988)] using a 24 coil magnetic probe array (eight spatial positions, three axis probes). The CTX is a magnetized, coaxial plasma gun presently being used to investigate the viability of high pulsed power plasma thrusters for advanced electric propulsion. Previous efforts on this device have indicated that high pulsed power plasma guns are attractive candidates for advanced propulsion that employ ideal magnetohydrodynamic (MHD) plasma stream flow through self-formed magnetic nozzles. Indirect evidence of magnetic nozzle formation was obtained from plasma gun performance and measurements of directed axial velocities up to vz∼107 cm/s. The purpose of this work is to make direct measurement of the time evolving magnetic field topology. The intent is to both identify that applied magnetic field distortion by the highly conductive plasma is occurring, and to provide insight into the details of discharge evolution. Data from a magnetic fluctuation probe array have been used to investigate the details of applied magnetic field deformation through the reconstruction of time-dependent flux profiles. Experimentally observed magnetic field line distortion has been compared to that predicted by a simple one-dimensional (1-D) model of the discharge channel. Such a comparison is utilized to estimate the axial plasma velocity in the thruster. Velocities determined in this manner are in approximate agreement with the predicted self-field magnetosonic speed and those measured by a time-of-flight spectrometer

  14. Non-modal theory of the kinetic ion temperature gradient driven instability of plasma shear flows across the magnetic field

    Science.gov (United States)

    Mikhailenko, V. V.; Mikhailenko, V. S.; Lee, Hae June

    2016-06-01

    The temporal evolution of the kinetic ion temperature gradient driven instability and of the related anomalous transport of the ion thermal energy of plasma shear flow across the magnetic field is investigated analytically. This instability develops in a steady plasma due to the inverse ion Landau damping and has the growth rate of the order of the frequency when the ion temperature is equal to or above the electron temperature. The investigation is performed employing the non-modal methodology of the shearing modes which are the waves that have a static spatial structure in the frame of the background flow. The solution of the governing linear integral equation for the perturbed potential displays that the instability experiences the non-modal temporal evolution in the shearing flow during which the unstable perturbation becomes very different from a canonical modal form. It transforms into the non-modal structure with vanishing frequency and growth rate with time. The obtained solution of the nonlinear integral equation, which accounts for the random scattering of the angle of the ion gyro-motion due to the interaction of ions with ensemble of shearing waves, reveals similar but accelerated process of the transformations of the perturbations into the zero frequency structures. It was obtained that in the shear flow the anomalous ion thermal conductivity decays with time. It is a strictly non-modal effect, which originates from the temporal evolution of the shearing modes turbulence.

  15. A differentially pumped argon plasma in the linear plasma generator Magnum-PSI: gas flow and dynamics of the ionized fraction

    International Nuclear Information System (INIS)

    Magnum-PSI is a linear plasma generator designed to reach the plasma-surface interaction (PSI) regime of ITER and nuclear fusion reactors beyond ITER. To reach this regime, the influx of cold neutrals from the source must be significantly lower than the plasma flux reaching the target. This is achieved by a differential pumping scheme, where the vacuum vessel is divided by skimmers into separate chambers which are individually pumped. The non-magnetized expansion of 5 Pa m3 s-1 (3 slm) argon in a low background pressure was studied in the differentially pumped vacuum vessel fitted with non-cooled flat skimmers. The behavior of the neutral component was studied with direct simulation Monte Carlo simulations and Rayleigh scattering measurements. Thomson scattering and double Langmuir probe measurements were performed on the ionized fraction. It was found that the electrons and neutral particles are not completely coupled in the shock front. The neutral fraction shows clear signs of invasion from hotter background gas, causing the average temperature and density to increase before the shock. This is also shown in the ionization ratio, which has been determined in front of and behind the first skimmer. This study helps us to understand the behavior of the gas flow in the machine and validates our modeling.

  16. Effect of anode attachment on flow structure of plasma jet generated in water stabilized torch

    Czech Academy of Sciences Publication Activity Database

    Hrabovský, Milan; Konrád, Miloš; Kopecký, Vladimír; Sember, Viktor

    International Centre for Heat and Mass Transfer, ICHMT, 1999 - (Fauchais, P.). s. 114+0 [International Symposium on Heat and Mass Transfer under Plasma Conditions/2nd./. 19.04.1999-23.04.1999, Tekirova, Antalya ] Subject RIV: BL - Plasma and Gas Discharge Physics

  17. Thomson scattering measurements of heat flow in a laser-produced plasma

    Czech Academy of Sciences Publication Activity Database

    Hawreliak, J.; Chambers, D. M.; Glenzer, S. H.; Gouveka, A.; Kingham, R. J.; Marjoribanks, R. S.; Pinto, P. A.; Renner, Oldřich; Soundhauss, P.; Topping, S.; Wolfrum, E.; Young, P. E.; Wark, J. S.

    2004-01-01

    Roč. 37, - (2004), s. 1541-1551. ISSN 0953-4075 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z1010921 Keywords : laser-produced plasma * Thomson scattering * Fokker-Planck simulations * electron distribution function Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.761, year: 2004

  18. Fluctuations, transport and flows in TCV scrape-off layer plasmas

    Czech Academy of Sciences Publication Activity Database

    Garcia, E.O.; Horáček, Jan; Naulin, V.; Nielsen, A.H.; Pitts, R.A.; Rasmussen, J.J.

    2007-01-01

    Roč. 47, č. 7 (2007), s. 667-676. ISSN 0029-5515 Grant ostatní: -(XE) European Training fellowships and Grants (Euratom), EDGETURB Institutional research plan: CEZ:AV0Z20430508 Keywords : tokamak * plasma * scrape-off layer * turbulence * interchange instability Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.278, year: 2007

  19. Immunophenotypic Characterization and Quantification of Neoplastic Bone Marrow Plasma Cells by Multiparametric Flow Cytometry and Its Clinical Significance in Korean Myeloma Patients

    OpenAIRE

    Cho, Young-Uk; Park, Chan-Jeoung; Park, Seo-Jin; Chi, Hyun-Sook; Jang, Seongsoo; Park, Sang Hyuk; Seo, Eul-Ju; Yoon, Dok Hyun; Lee, Jung-Hee; Suh, Cheolwon

    2013-01-01

    Multiparametric flow cytometry (MFC) allows discrimination between normal and neoplastic plasma cells (NeoPCs) within the bone marrow plasma cell (BMPC) compartment. This study sought to characterize immunophenotypes and quantitate the proportion of NeoPCs in BMPCs to diagnose plasma cell myeoma (PCM) and evaluate the prognostic impact of this method. We analyzed the MFC data of the bone marrow aspirates of 76 patients with PCM and 33 patients with reactive plasmacytosis. MFC analysis was per...

  20. Effect of disodium cromoglycate (DSCG) and antihistamines on postirradiation cerebral blood flow and plasma levels of histamine and neurotensin

    Energy Technology Data Exchange (ETDEWEB)

    Cockerham, L.G.; Pautler, E.L.; Carraway, R.E.; Cochrane, D.E.; Hampton, J.D.

    1988-02-01

    In an attempt to elucidate mechanisms underlying the irradiation-induced decrease in regional cerebral blood flow (rCBF) in primates, hippocampal and visual cortical blood flows of rhesus monkeys were measured by hydrogen clearance, before and after exposure to 100 Gy, whole-body, gamma irradiation. Systemic blood pressures were monitored simultaneously. Systemic arterial plasma histamine and neurotensin levels were determined preirradiation and postirradiation. Compared to control animals, the irradiated monkeys exhibited an abrupt decline in systemic blood pressure to 23% of the preirradiation level within 10 min postirradiation, falling to 12% by 60 min. A decrease in hippocampal blood flow to 32% of the preirradiation level was noted at 10 min postirradiation, followed by a slight recovery to 43% at 30 min and a decline to 23% by 60 min. The cortical blood flow for the same animals showed a steady decrease to 29% of the preirradiation levels by 60 min postirradiation. Animals given the mast cell stabilizer disodium cromoglycate and the antihistamines mepyramine and cimetidine before irradiation did not exhibit an abrupt decline in blood pressure but displayed a gradual decrease to a level 33% below preirradiation levels by 60 min postirradiation. Also, the treated, irradiated monkeys displayed rCBF values that were not significantly different from the nonirradiated controls. The plasma neurotensin levels in the irradiated animals, treated and untreated, indicated a nonsignificant postirradiation increase above control levels. However, the postirradiation plasma histamine levels in both irradiated groups showed an increase of approximately 1600% above the preirradiation levels and the postirradiation control levels.

  1. Effect of disodium cromoglycate (DSCG) and antihistamines on postirradiation cerebral blood flow and plasma levels of histamine and neurotensin

    International Nuclear Information System (INIS)

    In an attempt to elucidate mechanisms underlying the irradiation-induced decrease in regional cerebral blood flow (rCBF) in primates, hippocampal and visual cortical blood flows of rhesus monkeys were measured by hydrogen clearance, before and after exposure to 100 Gy, whole-body, gamma irradiation. Systemic blood pressures were monitored simultaneously. Systemic arterial plasma histamine and neurotensin levels were determined preirradiation and postirradiation. Compared to control animals, the irradiated monkeys exhibited an abrupt decline in systemic blood pressure to 23% of the preirradiation level within 10 min postirradiation, falling to 12% by 60 min. A decrease in hippocampal blood flow to 32% of the preirradiation level was noted at 10 min postirradiation, followed by a slight recovery to 43% at 30 min and a decline to 23% by 60 min. The cortical blood flow for the same animals showed a steady decrease to 29% of the preirradiation levels by 60 min postirradiation. Animals given the mast cell stabilizer disodium cromoglycate and the antihistamines mepyramine and cimetidine before irradiation did not exhibit an abrupt decline in blood pressure but displayed a gradual decrease to a level 33% below preirradiation levels by 60 min postirradiation. Also, the treated, irradiated monkeys displayed rCBF values that were not significantly different from the nonirradiated controls. The plasma neurotensin levels in the irradiated animals, treated and untreated, indicated a nonsignificant postirradiation increase above control levels. However, the postirradiation plasma histamine levels in both irradiated groups showed an increase of approximately 1600% above the preirradiation levels and the postirradiation control levels

  2. The influence of the structures and compounds of DLC coatings on the barrier properties of PET bottles

    International Nuclear Information System (INIS)

    To reduce the oxygen transmission rate through a polyethylene terephthalate (PET) bottle (an organic plastic) diamond-like carbon (DLC) coatings on the inner surface of the PET bottle were deposited by radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) technology with C2H2 as the source of carbon and Ar as the diluted gas. As the barrier layer to humidity and gas permeation, this paper analyses the DLC film structure, composition, morphology and barrier properties by Fourier transform infrared, atomic force microscopy, scanning electron microscopy and oxygen transmission rate in detail. From the spectrum, it is found that the DLC film mainly consists of sp3 bonds. The barrier property of the films is significantly relevant to the sp3 bond concentration in the coating, the film thickness and morphology. Additionally, it is found that DLC film deposited in an inductively coupled plasma enhanced capacitively coupled plasma source shows a compact, homogeneous and crack-free surface, which is beneficial for a good gas barrier property in PET bottles. (fluids, plasmas and electric discharges)

  3. Levitated superconductor ring trap (mini-RT) project - A new self-organized structure with strong plasma flow

    International Nuclear Information System (INIS)

    Mahajan-Yoshida has theoretically developed a new relaxation state under the condition of a strong plasma flow, and proposed a possibility for confining high beta plasmas. In this self-organized state, two fluids (electron and ion) would relax to the condition given by the relation β + (V/VA)2 = const.. An internal coil device is suitable for studying a self-organized structure with strong plasma flow, because a strong toroidal flow is easily induced by introducing an appropriate radial electric field. We are constructing a Mini-RT device, which is equipping a floating coil with a high temperature superconductor (HTS) coil (R=0.15m, Ic=50kAturns). The magnetic field strength near the floating coil is around 0.1 T, and the plasma production with 2.45 GHz Electron Cyclotron Heating is planned. We are preparing several techniques to build up the radial electric field in the plasma such as the direct insertion of the electrode and so on. The utilization of direct orbit loss of high energy electrons produced by ECH might be an interesting method. The orbit calculation results show that the electrons with the energy of more than 10 keV would escape at the outer region of the plasma column, yielding the build-up of the radial electric field. The engineering aspect of the HTS coil is in progress. We have fabricated a small HTS coil (R=0.04 m and Ic= 2.6 kAturns), and succeeded in levitating it during four minutes with an accuracy of a few tens of micrometers. Since the HTS coil is excited by the external power supply, the persistent current switch for the HTS coil has been developed. The HTS coil system with the PCS coil has been fabricated and the excitation test has been carried out. We have succeeded in achieving a persistent current, and it is found that the decay constant of the coil current is evaluated to be around 40 hours and 6.5 hours at 20 K and 40 K, respectively. (author)

  4. Conformational properties of bottle-brush polymers

    Science.gov (United States)

    Denesyuk, N. A.

    2003-05-01

    General and renormalized perturbation theories are used to study the conformational properties of a bottle-brush molecule, composed of multiarmed polymer stars grafted regularly onto a flexible backbone. The end-to-end distances of the backbone and of an arm of the middle star are calculated within the first order of perturbation theory. For the high grafting densities of stars, the calculated expressions are generalized with the help of the scaling arguments to give the equivalent power laws. According to these laws, the molecule may adopt a sequence of three different conformations (star-rod-coil) as the length of the backbone grows.

  5. Conformational properties of bottle-brush polymers.

    Science.gov (United States)

    Denesyuk, N A

    2003-05-01

    General and renormalized perturbation theories are used to study the conformational properties of a bottle-brush molecule, composed of multiarmed polymer stars grafted regularly onto a flexible backbone. The end-to-end distances of the backbone and of an arm of the middle star are calculated within the first order of perturbation theory. For the high grafting densities of stars, the calculated expressions are generalized with the help of the scaling arguments to give the equivalent power laws. According to these laws, the molecule may adopt a sequence of three different conformations (star-rod-coil) as the length of the backbone grows. PMID:12786171

  6. Treatment of nursing bottle caries with ribbond

    Directory of Open Access Journals (Sweden)

    Ritu Jindal

    2013-01-01

    Full Text Available Ribbond is a biocompatible, esthetic material made from high-strength polyethylene fiber. Lenowoven polyethylene ribbon (Ribbond has been used successfully for tooth splinting, replacement of missing teeth, reinforcement of provisional acrylic resin fixed partial dentures, and orthodontic retention. This article presents the application of this polyethylene ribbon - RIBBOND - for the treatment of nursing bottle caries. To conclude we suggest that this combined technique of polyethylene fibers and composite material could be a very efficient alternative procedure to conventional treatment plans in pedodontic practice, with excellent esthetics and functional results.

  7. Portable NIR bottled liquid explosive detector

    Science.gov (United States)

    Itozaki, Hideo; Ono, Masaki; Ito, Shiori; Uekawa, Keisuke; Miyato, Yuji; Sato-Akaba, Hideo

    2016-05-01

    A near infrared bottled liquid scanner has been developed for security check at airports for anti-terrorism. A compact handheld liquid scanner has been developed using an LED as a light source, instead of a halogen lamp. An LED has much smaller size, longer life time and lower power consumption than those of the lamp. However, it has narrower wave band. Here, we tried to use LEDs to scan liquids and showed the possibility that LEDs can be used as a light source of liquid detector.

  8. Numerical Analysis of Interaction Between Single-Pulse Laser-Induced Plasma and Bow Shock in a Supersonic Flow

    Institute of Scientific and Technical Information of China (English)

    FANG Juan; HONG Yanji; LI Qian

    2012-01-01

    The interaction of laser-induced plasma and bow shock over a blunt body is inves- tigated numerically in an M∞ =6.5 supersonic flow. A ray-tracing method is used for simulating the process of laser focusing. The gas located at the focused zone is ionized and broken down and transformed into plasma. In a supersonic flow the plasma moves downstream and begins to interact with the bow shock when it approaches the surface of the blunt body. The parameters of flowfield and blunt body surface are changed due to the interaction. By analyzing phenomena occurring in the complex unsteady flowfield during the interaction in detail, we can better under- stand the change of pressure on the blunt body surface and the mechanism of drag reduction by laser energy deposition. The results show that the bow shock is changed into an oblique shock due to the interaction of the laser-induced low-density zone with the bow shock, so the wave drag of the blunt body is reduced.

  9. Fundamental experiments for FBX burner linear fusion reactor core with FBX plasma flow

    International Nuclear Information System (INIS)

    FBX is a production and confinement scheme of a spherical torus that carries a strong plasma current with both toroidal and poloidal components. On the other hand HI-I is a fundamental experiment on moving plasma. With two of them, a new type of fusion reactor scheme FBX-III BURNER (III) is established. In this paper, the fundamental results of the first two types of experiments are introduced to find out a total plasma behavior of the long term project. 9 refs., 5 figs

  10. Engineering Study of 500 ML Sample Bottle Transportation Methods

    International Nuclear Information System (INIS)

    This engineering study reviews and evaluates all available methods for transportation of 500-mL grab sample bottles, reviews and evaluates transportation requirements and schedules and analyzes and recommends the most cost-effective method for transporting 500-mL grab sample bottles

  11. Filling or Draining a Water Bottle with Two Holes

    Science.gov (United States)

    Cross, Rod

    2016-01-01

    Three simple experiments are described using a small water bottle with two holes in the side of the bottle. The main challenge is to predict and then explain the observations, but the arrangements can also be used for quantitative measurements concerning hydrostatic pressure, Bernoulli's equation, surface tension and bubble formation.

  12. 27 CFR 31.201 - Refilling of liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Refilling of liquor... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS ALCOHOL BEVERAGE DEALERS Reuse and Possession of Used Liquor Bottles § 31.201 Refilling of liquor bottles. No person who sells, or offers for sale, distilled...

  13. 27 CFR 27.204 - Distinctive liquor bottles.

    Science.gov (United States)

    2010-04-01

    ... such bottles are found by the appropriate TTB officer to— (1) Meet the requirements of 27 CFR part 5... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Distinctive liquor bottles..., DEPARTMENT OF THE TREASURY LIQUORS IMPORTATION OF DISTILLED SPIRITS, WINES, AND BEER Requirements for...

  14. Filling or draining a water bottle with two holes

    Science.gov (United States)

    Cross, Rod

    2016-07-01

    Three simple experiments are described using a small water bottle with two holes in the side of the bottle. The main challenge is to predict and then explain the observations, but the arrangements can also be used for quantitative measurements concerning hydrostatic pressure, Bernoulli’s equation, surface tension and bubble formation.

  15. "Bottled or Tap?" A Controversy for Science, Economics, and Society

    Science.gov (United States)

    Lapham, Steven S.

    2009-01-01

    Every year, Americans spend billions of dollars on bottled water. They purchase a bottle from the vending machine or buy a case at the grocery, no longer considering the water that's freely available from their taps. As consumers and as citizens, however, Americans should pause to study the personal and public consequences of this choice. In this…

  16. Heat Transfer in Glass, Aluminum, and Plastic Beverage Bottles

    Science.gov (United States)

    Clark, William M.; Shevlin, Ryan C.; Soffen, Tanya S.

    2010-01-01

    This paper addresses a controversy regarding the effect of bottle material on the thermal performance of beverage bottles. Experiments and calculations that verify or refute advertising claims and represent an interesting way to teach heat transfer fundamentals are described. Heat transfer coefficients and the resistance to heat transfer offered…

  17. Engineering Study of 500 ML Sample Bottle Transportation Methods

    Energy Technology Data Exchange (ETDEWEB)

    BOGER, R.M.

    1999-08-25

    This engineering study reviews and evaluates all available methods for transportation of 500-mL grab sample bottles, reviews and evaluates transportation requirements and schedules and analyzes and recommends the most cost-effective method for transporting 500-mL grab sample bottles.

  18. 27 CFR 25.158 - Tax computation for bottled beer.

    Science.gov (United States)

    2010-04-01

    ... bottled beer. 25.158 Section 25.158 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Tax on Beer Determination of Tax § 25.158 Tax computation for bottled beer. Barrel equivalents for various case sizes are as follows: (a) For U.S....

  19. Improvement of the Performance of Graphite Felt Electrodes for Vanadium-Redox-Flow-Batteries by Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Eva-Maria Hammer

    2014-02-01

    Full Text Available In the frame of the present contribution oxidizing plasma pretreatment is used for the improvement of the electrocatalytic activity of graphite felt electrodes for Vanadium-Redox-Flow-Batteries (VRB. The influence of the working gas media on the catalytic activity and the surface morphology is demonstrated. The electrocatalytical properties of the graphite felt electrodes were examined by cyclic voltammetry and electrochemical impedance spectroscopy. The obtained results show that a significant improvement of the redox reaction kinetics can be achieved for all plasma modified samples using different working gasses (Ar, N2 and compressed air in an oxidizing environment. Nitrogen plasma treatment leads to the highest catalytical activities at the same operational conditions. Through a variation of the nitrogen plasma treatment duration a maximum performance at about 14 min cm-2 was observed, which is also represented by a minimum of 90 Ω in the charge transfer resistance obtained by EIS measurements. The morphology changes of the graphitized surface were followed using SEM.

  20. Gene expression responses of HeLa cells to chemical species generated by an atmospheric plasma flow

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Mayo, E-mail: yokoyama@plasma.ifs.tohoku.ac.jp [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Johkura, Kohei, E-mail: kohei@shinshu-u.ac.jp [Department of Histology and Embryology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621 (Japan); Sato, Takehiko, E-mail: sato@ifs.tohoku.ac.jp [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-08-08

    Highlights: • Response of HeLa cells to a plasma-irradiated medium was revealed by DNA microarray. • Gene expression pattern was basically different from that in a H{sub 2}O{sub 2}-added medium. • Prominently up-/down-regulated genes were partly shared by the two media. • Gene ontology analysis showed both similar and different responses in the two media. • Candidate genes involved in response to ROS were detected in each medium. - Abstract: Plasma irradiation generates many factors able to affect the cellular condition, and this feature has been studied for its application in the field of medicine. We previously reported that hydrogen peroxide (H{sub 2}O{sub 2}) was the major cause of HeLa cell death among the chemical species generated by high level irradiation of a culture medium by atmospheric plasma. To assess the effect of plasma-induced factors on the response of live cells, HeLa cells were exposed to a medium irradiated by a non-lethal plasma flow level, and their gene expression was broadly analyzed by DNA microarray in comparison with that in a corresponding concentration of 51 μM H{sub 2}O{sub 2}. As a result, though the cell viability was sufficiently maintained at more than 90% in both cases, the plasma-medium had a greater impact on it than the H{sub 2}O{sub 2}-medium. Hierarchical clustering analysis revealed fundamentally different cellular responses between these two media. A larger population of genes was upregulated in the plasma-medium, whereas genes were downregulated in the H{sub 2}O{sub 2}-medium. However, a part of the genes that showed prominent differential expression was shared by them, including an immediate early gene ID2. In gene ontology analysis of upregulated genes, the plasma-medium showed more diverse ontologies than the H{sub 2}O{sub 2}-medium, whereas ontologies such as “response to stimulus” were common, and several genes corresponded to “response to reactive oxygen species.” Genes of AP-1 proteins, e.g., JUN