WorldWideScience

Sample records for plasma composition measurements

  1. Plasma ion composition measurements for Europa

    Science.gov (United States)

    Sittler, E. C.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Christian, E. R.; Lipatov, A. S.; Mahaffy, P. R.; Paschalidis, N. P.; Coplan, M. A.; Cassidy, T. A.; Richardson, J. D.; Fegley, B.; Andre, N.

    2013-11-01

    Jupiter magnetospheric interactions and surface composition, both important to subsurface ocean detection for the Galilean icy moons Europa, Ganymede, and Callisto, can be measured using plasma ion mass spectrometry on either an orbiting spacecraft or one designed for multiple flybys of these moons. Detection of emergent oceanic materials at the Europa surface is more likely than at Ganymede and Callisto. A key challenge is to resolve potential intrinsic Europan materials from the space weathering patina of iogenic species implanted onto the sensible surface by magnetospheric interactions. Species-resolved measurements of pickup ion currents are also critical to extraction of oceanic induced magnetic fields from magnetospheric interaction background dominated by these currents. In general the chemical astrobiological potential of Europa should be determined through the combination of surface, ionospheric, and pickup ion composition measurements. The requisite Ion Mass Spectrometer (IMS) for these measurements would need to work in the high radiation environment of Jupiter's magnetosphere between the orbits of Europa and Ganymede, and beyond. A 3D hybrid model of the moon-magnetosphere interaction is also needed to construct a global model of the electric and magnetic fields, and the plasma environment, around Europa. Europa's ionosphere is probably usually dominated by hot pickup ions with 100-1000 eV temperatures, excursions to a "classical" cold ionosphere likely being infrequent. A field aligned ionospheric wind driven by the electron polarization electric field should arise and be measurable.

  2. Plasma IMS Composition Measurements for Europa and Ganymede

    Science.gov (United States)

    Sittler, E.; Cooper, J.; Hartle, R.; Lipatov, A.; Mahaffy, P.; Paterson, W.; Paschalidis, N.; Coplan, M.; Cassidy, T.

    2010-01-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4n surface composition to trace elemental [1] and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged.

  3. Plasma IMS Composition Measurements for Europa and Ganymede

    Science.gov (United States)

    Sittler, E. C.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Lipatov, A. S.; Paschalidis, N. P.; Coplan, M. A.; Cassidy, T. A.

    2010-12-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphases on Europa and Ganymede from these respective space agencies. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter’s magnetosphere and the Galilean satellites. For NASA’s Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter’s magnetosphere and 2) infer the 4π surface composition to trace elemental and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa’s sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa’s or Ganymede’s surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA’s Astrobiology Instrument Development Program (ASTID), would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged. The ASTID-supported IMS, applicable to the NASA spacecraft, is designed to operate in a high radiation environment with minor and trace ion detection capability. The latter goal is achieved by measuring pickup ions at spacecraft altitudes and using a 3D hybrid model of the interaction in order to construct 3D global model of the electric and magnetic fields around these bodies. The pickup ion trajectories can then be traced back down to the surface. In the case of Europa we also show that Europa’s ionosphere is

  4. Composition Measurements at the Magnetopause and in the Plasma Mantle

    Science.gov (United States)

    Gary, S. P.

    1998-01-01

    This final report describes activities under NASA grant NAGW-4049 to Lockheed Missiles and Space Company. The report covers the entire period of the grant from 15 August 1994 to 31 January 1998. The original grant was for 3 years ending in August 1997; however the grant was extended 6 months to accomodate additional data analysis that added significantly to the scientific results. This is a grant under the NASA Supporting Research and Technology Program for the analysis and interpretation of the combined scientific data from the ISEE-1 Plasma Composition Experiment and the AMPTE/CCE Hot Plasma Composition Experiment. These combined data sets were used in a study of the Earth's magnetopause to develop a fundamental understanding of plasma entry and dynamics at the boundary and formation and maintenance of the low latitude boundary layer under a variety of solar wind and magnetospheric conditions and at a wide range of local times.

  5. Measurements of plasma composition in the TEXTOR tokamak by collective Thomson scattering

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Korsholm, Søren Bang; Nielsen, Stefan Kragh;

    2012-01-01

    with wave vector components nearly perpendicular to the magnetic field. Under such conditions the sensitivity of the CTS spectrum to plasma composition is enhanced by the spectral signatures of the ion cyclotron motion and of weakly damped ion Bernstein waves. Recent experiments on TEXTOR demonstrated......We demonstrate the use of collective Thomson scattering (CTS) for spatially localized measurements of the isotopic composition of magnetically confined fusion plasmas. The experiments were conducted in the TEXTOR tokamak by scattering millimeter-wave probe radiation off plasma fluctuations...... the ability to resolve these signatures in the CTS spectrum as well as their sensitivity to the ion species mix in the plasma. This paper shows that the plasma composition can be inferred from the measurements through forward modeling of the CTS spectrum. We demonstrate that spectra measured in plasmas...

  6. Temporally resolved plasma composition measurements by collective Thomson scattering in TEXTOR

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Korsholm, Søren Bang; Nielsen, Stefan Kragh

    2012-01-01

    Fusion plasma composition measurements by collective Thomson scattering (CTS) were demonstrated in recent proof-of-principle measurements in TEXTOR [S. B. Korsholm et al., Phys. Rev. Lett. 106, 165004 (2011)]. Such measurements rely on the ability to resolve and interpret ion cyclotron structure...

  7. Plasma IMS Composition Measurements for Europa and the Other Galilean Moons

    Science.gov (United States)

    Sittler, Edward; Cooper, John; Hartle, Richard; Lipatov, Alexander; Mahaffy, Paul; Paterson, William; Pachalidis, Nick; Coplan, Mike; Cassidy, Tim

    2010-01-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4 pi surface composition to trace elemental and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged. The composition of the global surfaces of Europa and Ganymede can be inferred from the measurement of ejected neutrals and pick-up ions using at minimum an in situ payload including MAG and IMS also fully capable of meeting Level 1 mission requirements for ocean detection and survey. Elemental and isotopic analysis of potentially extruded oceanic materials at the moon surfaces would further support the ocean objectives. These measurements should be made from a polar orbiting spacecraft about Europa or Ganymede at height 100 km. The ejecta produced by

  8. Measurements of ion temperature and plasma hydrogenic composition by collective Thomson scattering in neutral beam heated discharges at TEXTOR

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Salewski, Mirko; Korsholm, Søren Bang

    2013-01-01

    A method is developed to perform plasma composition and ion temperature measurements across the plasma minor radius in TEXTOR based on ion cyclotron structures in collective Thomson scattering spectra. By gradually moving the scattering volume, we obtain measurements across the outer midplane...

  9. Giotto data analysis: Electron plasma and heavy ion composition measurements at Comet Halley

    Science.gov (United States)

    Lin, Robert P.

    1992-01-01

    This investigation involved the analysis of electron plasma and heavy ion composition measurements made by the COPERNIC (COmplete Positive ion, Electron, and Ram Negative Ion measurements near Comet Halley) plasma experiment during the close fly-by of Halley by the European Space Agency's Giotto spacecraft. The experiment provided measurements of the full 3-dimensional distribution of 10 eV-30 keV electrons, and mass analysis of cold cometary ions from 10-210 amu. The analysis of the COPERNIC data has yielded some remarkable results, including: The discovery of negatively charged ions in the inner coma; the discovery of far heavier (mass is greater than 50 amu) ions than predicted, dominated by complex molecular ions made up of C, H, O, and N; the discovery of an adiabatic heating effect on electrons from the compression of the solar wind plasma; the identification of several organic and sulfur bearing ions; and the discovery of a new 'mystery region' where electrons are accelerated to high energies. These discoveries were in addition to the detailed analysis of 'expected' features at Comet Halley. Although this grant has expired, analysis continues on the data at a low (unfunded) level, and it is expected that more significant results will be obtained. A bibliography of the papers resulting from this research is attached, and a copy of each paper is included.

  10. Plasma IMS Composition Measurements for Europa and the Other Galilean Moons

    Science.gov (United States)

    Sittler, Edward; Cooper, John; Hartle, Richard; Lipatov, Alexander; Mahaffy, Paul; Paterson, William; Pachalidis, Nick; Coplan, Mike; Cassidy, Tim

    2010-05-01

    NASA and ESA are planning the joint Europa Jupiter System Mission (EJSM) to the Jupiter system with specific emphasis to Europa and Ganymede, respectively. The Japanese Space Agency is also planning an orbiter mission to explore Jupiter's magnetosphere and the Galilean satellites. For NASA's Jupiter Europa Orbiter (JEO) we are developing the 3D Ion Mass Spectrometer (IMS) with two main goals which can also be applied to the other Galilean moons, 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the 4? surface composition to trace elemental [1] and significant isotopic levels. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second gives information about transfer of material between the Galilean moons, and between the moon surfaces and subsurface layers putatively including oceans. The measurement of the interactions for all the Galilean moons can be used to trace the in situ ion measurements of pickup ions back to either Europa's or Ganymede's surface from the respectively orbiting spacecraft. The IMS instrument, being developed under NASA's Astrobiology Instrument Development Program, would maximally achieve plasma measurement requirements for JEO and EJSM while moving forward our knowledge of Jupiter system composition and source processes to far higher levels than previously envisaged. The composition of the global surfaces of Europa and Ganymede can be inferred from the measurement of ejected neutrals and pick-up ions using at minimum an in situ payload including MAG and IMS also fully capable of meeting Level 1 mission requirements for ocean detection and survey. Elemental and isotopic analysis of potentially extruded oceanic materials at the moon surfaces would further support the ocean objectives. These measurements should be made from a polar orbiting spacecraft about Europa or Ganymede at height ~ 100 km. The ejecta produced by

  11. Titan's Topside Ionospheric Composition: Cassini Plasma Spectrometer Ion Mass Spectrometer Measurements

    Science.gov (United States)

    Sittler, Edward; Hartle, Richard; Ali, Ashraf; Cooper, John; Lipatov, Alexander; Simpson, David; Sarantos, Menelaos; Chornay, Dennis; Smith, Todd

    2017-01-01

    We present ion composition measurements of Titan's topside ionosphere using both T9 and T15 Cassini Plasma Spectrometer (CAPS) Ion Mass Spectrometer (IMS) measurements. The IMS is able to make measurements of Titan's ionosphere due to ionospheric outflows as originally reported for the T9 flyby. This allows one to take advantage of the unique capabilities of the CAPS IMS which measures both the mass-per-charge (M/Q) of the ions and the fragments of the ions produced inside the sensor such as carbon, nitrogen and oxygen fragments. Specific attention will be given to such ions as NH4 +, N +, O +, CH4 +, CxHy +, and HCNH + ions as examples. The CAPS IMS uses a time-of-flight (TOF) technique which accelerates ions up to 14.6 kV, so they can pass through ultra-thin carbon foils. Neutral fragments are used to measure the ion M/Q and positive fragments to measure the atomic components. We preliminarily find, by using IMS measurements of T9 and T15 ionospheric outflows, evidence for methane group ions, nitrogen ions, ammonium ions, water group ions and CnHm + ions with n = 2, 3, and 4 within Titan's topside ionosphere. E.C. Sittler acknowledges support at Goddard Space Flight Center by the CAPS Cassini Project from JPL funds under contract # NAS703001TONMO711123/1405851.

  12. Plasma IMS Composition Measurements for Europa, Ganymede, and the Jovian System

    Science.gov (United States)

    Sittler, E. C., Jr.; Cooper, J. F.; Hartle, R. E.; Paterson, W. R.; Christian, E. R.; Lipatov, A. S.; Mahaffy, P R.; Paschalidis, N.; Sarantos, M.; Coplan, M. A.; Cassidy, T. A.; Wurz, P.

    2011-01-01

    NASA and ESA are now planning a reduced version of the joint Europa Jupiter System Mission (EJSM), potentially including a radically descoped Jupiter Europa Orbiter (JEO) but still with magnetometer and plasma instruments. Similar field and plasma instrumentation would also reside on ESA's Jupiter Ganymede Orbiter (JGO), which conceivably could carry out multiple flybys of Europa before entering orbit at Ganymede. We are developing the 3D Ion Mass Spectrometer (IMS) designed to measure both major and minor ion species within the high radiation environment of Jupiter's magnetosphere and the icy Galilean moons. The IMS covers the energy range from 10 eV to 30 keY, wide field-of-view (FOV) capability and 10-60 sec time resolution for major ions. This instrument has two main goals: 1) measure the plasma interaction between Europa and Jupiter's magnetosphere and 2) infer the global surface composition to trace elemental and significant isotopic levels; these goals are also applicable for in-situ measurements at Ganymede and Callisto, and remotely everywhere via the iogenic plasma for 10. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second goal gives information about transfer of material between the Galilean moons, e.g. mainly from 10 to the other moons, and further allows detection of oceanic materials emergent to the moon surfaces from subsurface layers putatively including salt water oceans. Outgassed exospheric materials are probed by the IMS by measuring pickup ions accelerated up to spacecraft altitudes of approximately 100-200 km in electric fields extending through the local magnetospheric environment and moon exosphere to the surface. Our 3D hybrid kinetic model of the moon-magnetosphere interaction is used to construct a global model of electric and magnetic fields for tracing of pickup ion trajectories back to the sources at approximate surface resolution of 100 km. We

  13. Plasma IMS Composition Measurements for Europa, Ganymede, and the Jovian Systems

    Science.gov (United States)

    Sittler, E.; Cooper, J.; Hartle, R.; Paterson ,W.; Christian, E.; Mahaffy, P.; Paschalidis, N.; Lipatov, A.; Sarantos, M.; Coplan, M.; Cassidy, T.; Wurz, P.

    2011-01-01

    NASA and ESA are now planning a reduced version of the joint Europa Jupiter System Mission (EJSM), potentially including a radically descoped Jupiter Europa Orbiter (JEO) but still with magnetometer and plasma instruments. Similar field and plasma instrumentation would also reside on ESA's Jupiter Ganymede Orbiter (JGO), which conceivably could carry out multiple flybys of Europa before entering orbit at Ganymede. We are developing the 3D Ion Mass Spectrometer (IMS) designed to measure both major and minor ion species within the high radiation environment of Jupiter s magnetosphere and the icy Galilean moons. The IMS covers the energy range from 10 eV to 30 keV, wide field-ofview (FOV) capability and 10-60 sec time resolution for major ions. This instrument has two main goals: 1) measure the plasma interaction between Europa and Jupiter s magnetosphere and 2) infer the global surface composition to trace elemental and significant isotopic levels; these goals are also applicable for in-situ measurements at Ganymede and Callisto, and remotely everywhere via the iogenic plasma for Io. The first goal supports the magnetometer (MAG) measurements, primarily directed at detection of Europa's sub-surface ocean, while the second goal gives information about transfer of material between the Galilean moons, e.g. mainly from Io to the other moons, and further allows detection of oceanic materials emergent to the moon surfaces from subsurface layers putatively including salt water oceans. Outgassed exospheric materials are probed by the IMS by measuring pickup ions accelerated up to spacecraft altitudes of approximately 100-200 km in electric fields extending through the local magnetospheric environment and moon exosphere to the surface. Our 3D hybrid kinetic model of the moon-magnetosphere interaction is used to construct a global model of electric and magnetic fields for tracing of pickup ion trajectories back to the sources at approximate surface resolution of 100 km. We

  14. STS-46 plasma composition measurements using the EOIM-3 mass spectrometer

    Science.gov (United States)

    Hunton, Donald E.; Trzcinski, Edmund; Gosselin, Roger; Koontz, Steven; Leger, Lubert; Visentine, James T.

    1995-01-01

    One of the active instruments incorporated into the Evaluation of Oxygen Interactions with Materials - 3 experiment was a quadrupole mass spectrometer. The primary objectives for this instrument, which was built by the Air Force Phillips Laboratory and was a veteran of the STS-4 flight in 1982, were to quantify the flux of atomic oxygen striking the test surfaces in the EOIM-3 payload and to detect surface reaction products from the materials in the carousel. Other speakers in this session have covered the results of these experiments. Prior to the 40-hour-long dedicated EOIM-3 mission segment at the end of the STS-46 flight, the authors used the mass spectrometer to make measurements of ion and neutral gas composition in the shuttle environment. About 25 hours of data were collected during a variety of mission events, including Eureca deployment at high altitude and many tethered satellite system operations.

  15. Dependence of composition of stable molecules in N2-H2 plasmas on nitrogen gas flow rate ratio measured using a quartz sensor

    Science.gov (United States)

    Suzuki, Atsushi; Asahina, Shuichi

    2014-11-01

    Compositions of stable molecules in N2-H2 plasmas measured using a quartz sensor (Q-sensor) were compared with those measured using a quadrupole mass spectrometer (QMS) under various nitrogen gas flow rate ratio to determine the applicability of Q-sensor measurement to N2-H2 plasmas. The nitrogen flow rate ratio dependence of the Q-sensor results obtained 20 mm from the edge of the plasma electrodes (Z = 20 mm) tended to agree more qualitatively with the NH3 density measured by QMS compared with those measured at 70 mm. For pure nitrogen or hydrogen plasma, the results measured at Z = 20 mm differed from those of gas analyses using QMS. The analysis indicated that Q-sensor results obtained near discharges with various nitrogen flow rate ratios reflect information on stable molecules such as N2, H2, and NH3 but yield information on other stable molecules or other chemical species in pure N2 and H2 plasmas.

  16. Electron-Beam Atomic Spectroscopy for In Situ Measurements of Melt Composition for Refractory Metals: Analysis of Fundamental Physics and Plasma Models

    Science.gov (United States)

    Gasper, Paul Joseph; Apelian, Diran

    2015-04-01

    Electron-beam (EB) melting is used for the processing of refractory metals, such as Ta, Nb, Mo, and W. These metals have high value and are critical to many industries, including the semiconductor, aerospace, and nuclear industries. EB melting can also purify secondary feedstock, enabling the recovery and recycling of these materials. Currently, there is no method for measuring melt composition in situ during EB melting. Optical emission spectroscopy of the plasma generated by EB impact with vapor above the melt, a technique here termed electron-beam atomic spectroscopy, can be used to measure melt composition in situ, allowing for analysis of melt dynamics, facilitating improvement of EB melting processes and aiding recycling and recovery of these critical and high-value metals. This paper reviews the physics of the plasma generation by EB impact by characterizing the densities and energies of electrons, ions, and neutrals, and describing the interactions between them. Then several plasma models are introduced and their suitability to this application analyzed. Lastly, a potential method for calibration-free composition measurement is described and the challenges for implementation addressed.

  17. Measuring Kinetic Plasma Eigenmodes

    Science.gov (United States)

    Mattingly, Sean; Berumen, Jorge; Chu, Feng; Hood, Ryan; Skiff, Fred

    2015-11-01

    We present a method for measuring kinetic plasma eigenmodes of a cylindrical axially magnetized (1 kG) laboratory plasma (n ~109cm-3 , Te ~ 5eV , Ti ~ 0 . 06eV) by measuring velocity space correlation functions. This method simultaneously observes two separate laser induced fluorescence schemes. Each scheme has its own indepedently tunable laser and its own set of collection optics. With this setup, we are able to measure the time - averaged correlation function as a function of position on the cylindrical axis parallel to the magnetic field (z) and velocity on the deconvolved ion velocity distribution function (v) : C (z , v ,z' ,v' , τ) = t. The freedom of two lasers allows us to measure a two dimensional velocity correlation matrix. This matrix is investigated with the Vlasov equation in the collisionless and weakly collisional regime. The former case, which is continuous, is diagonalized with an integral transform defined by P. J. Morrison while the latter case, which is discrete, is diagonalized through the use of Hermite polynomials.

  18. Calibration of the ISEE plasma composition experiment

    Science.gov (United States)

    Baugher, C. R.; Olsen, R. C.; Reasoner, D. L.

    1986-01-01

    The Plasma Composition experiment on the ISEE-1 satellite was designed to measure ions from 1 to 16 amu, at energies from near zero to 16 keV. The two nearly identical flight instruments were calibrated by means of preflight laboratory tests and in-flight data comparisons. This document presents most of the details of those efforts, with special emphasis on the low energy (0 to 100 eV) portion of the instrument response. The analysis of the instrument includes a ray-tracing calculation, which follows an ensemble of test particles through the detector.

  19. Plasma Beam Measurements

    Science.gov (United States)

    1991-08-01

    GUN PLASMA BEAM / ,I 21 cm diameter = 0 GLASS DRIFT TUBE 50 cm diameter MCP CAMERA CLASS CROSSES (a) Gun muzzle /"- PLASA BEAM / TAROT z = 10 m MCP...discusses some of the hydrodynamic issues related to the calcula- tions. The reader may well wonder why hydrodynamics should be an issue in a 116 WL-TR-90...answer is yes for the slow beam cases and no for the fast beam cases. This is explained further. 118 WL-TR-90-83 The reader will recall the

  20. Measurement of the isotopic composition of uranium micrometer-size particles by femtosecond laser ablation-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, Amélie, E-mail: amelie.hubert@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Claverie, Fanny [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, UMR 5254, Hélioparc Pau-Pyrénées, 2 Avenue du Président Angot, 64053 Pau (France); Novalase SA, ZI de la Briqueterie, 6 Impasse du Bois de la Grange, 33610 Canejan (France); Pécheyran, Christophe [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, UMR 5254, Hélioparc Pau-Pyrénées, 2 Avenue du Président Angot, 64053 Pau (France); Pointurier, Fabien [CEA, DAM, DIF, F-91297 Arpajon (France)

    2014-03-01

    In this paper, we will describe and indicate the performance of a new method based on the use of femtosecond laser ablation (fs-LA) coupled to a quadrupole-based inductively coupled plasma mass spectrometer (ICP-QMS) for analyzing the isotopic composition of micrometer-size uranium particles. The fs-LA device was equipped with a high frequency source (till 10 kHz). We applied this method to 1–2 μm diameter-uranium particles of known isotopic composition and we compared this technique with the two techniques currently used for uranium particle analysis: Secondary Ionization Mass Spectrometry (SIMS) and Fission Track Thermal Ionization Mass Spectrometry (FT-TIMS). By optimizing the experimental conditions, we achieved typical accuracy and reproducibility below 4% on {sup 235}U/{sup 238}U for short transient signals of only 15 s related to 10 to 200 pg of uranium. The detection limit (at the 3 sigma level) was ∼ 350 ag for the {sup 235}U isotope, meaning that {sup 235}U/{sup 238}U isotope ratios in natural uranium particles of ∼ 220 nm diameter can be measured. We also showed that the local contamination resulting from the side deposition of ablation debris at ∼ 100 μm from the ablation crater represented only a small percentage of the initial uranium signal of the ablated particle. Despite the use of single collector ICP-MS, we were able to demonstrate that fs-LA-ICP-MS is a promising alternative technique for determining uranium isotopic composition in particle analysis. - Highlights: • An infrared femtosecond laser ablation device coupled to an ICP-MS is used. • The isotopic composition of micrometer-size U particles is measured. • Results are in good agreement with the ones obtained by other relevant techniques. • Detection limit is 350 attograms for the {sup 235}U isotope • {sup 235}U/{sup 238}U ratios can be measured in 220 nm diameter natural uranium particles.

  1. Turbulence measurements in fusion plasmas

    Science.gov (United States)

    Conway, G. D.

    2008-12-01

    Turbulence measurements in magnetically confined toroidal plasmas have a long history and relevance due to the detrimental role of turbulence induced transport on particle, energy, impurity and momentum confinement. The turbulence—the microscopic random fluctuations in particle density, temperature, potential and magnetic field—is generally driven by radial gradients in the plasma density and temperature. The correlation between the turbulence properties and global confinement, via enhanced diffusion, convection and direct conduction, is now well documented. Theory, together with recent measurements, also indicates that non-linear interactions within the turbulence generate large scale zonal flows and geodesic oscillations, which can feed back onto the turbulence and equilibrium profiles creating a complex interdependence. An overview of the current status and understanding of plasma turbulence measurements in the closed flux surface region of magnetic confinement fusion devices is presented, highlighting some recent developments and outstanding problems.

  2. Plasma Spray Forming of Nanostructured Composite Coatings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The nanostructure composite coating is obtained via plasma spraying of Al2O3-13 wt pct TiO2 powder. Brittle and hard lamella results from melted nanostructured powder. Ductile nanostructured matrix forms from unmelted nanostructured particles. Through the adjustment of constituent and nanostructure, hardness/strength and toughness/ductility are balanced and overall properties of the structure composite are achieved.

  3. Plasma Anemometer Measurements and Optimization

    Science.gov (United States)

    Marshall, Curtis; Matlis, Eric; Corke, Thomas; Gogineni, Sivaram

    2013-11-01

    Velocity measurements using a constant-current plasma anemometer were performed in a Mach 0.4 jet in order to further optimize the anemometer design. The plasma anemometer uses an AC glow discharge (plasma) formed in the air gap between two protruding low profile electrodes as the flow sensing element. The output from the anemometer is an amplitude modulated version of the AC voltage input that contains information about the mean fluctuating velocity components. Experiments were performed to investigate the effect of the electrode gap, AC current, and AC frequency on the mean and fluctuating velocity sensitivity and repeatability of the sensor. This involved mean velocity calibrations from 0 to 140 m/s and mean and fluctuating velocity profiles through the shear layer of the jet. Measurements with a constant temperature hot-wire anemometer were used for reference. The results showed an improvement in performance with increasing AC frequency that was attributed a more stable glow discharge. The agreement with the hot-wire were good, with the advantage of the plasma anemometer being its 100-times higher frequency response. Supported by Air Force SBIR Phase II FA8650-11-C-2199.

  4. Plasma penetration depth and mechanical properties of atmospheric plasma-treated 3D aramid woven composites

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X.; Yao, L.; Xue, J.; Zhao, D.; Lan, Y.; Qian, X. [Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education (China); Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China); Wang, C.X. [Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education (China); Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China); College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Qiu, Y. [Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education (China); Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China)], E-mail: ypqiu@dhu.edu.cn

    2008-12-30

    Three-dimensional aramid woven fabrics were treated with atmospheric pressure plasmas, on one side or both sides to determine the plasma penetration depth in the 3D fabrics and the influences on final composite mechanical properties. The properties of the fibers from different layers of the single side treated fabrics, including surface morphology, chemical composition, wettability and adhesion properties were investigated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), contact angle measurement and microbond tests. Meanwhile, flexural properties of the composites reinforced with the fabrics untreated and treated on both sides were compared using three-point bending tests. The results showed that the fibers from the outer most surface layer of the fabric had a significant improvement in their surface roughness, chemical bonding, wettability and adhesion properties after plasma treatment; the treatment effect gradually diminished for the fibers in the inner layers. In the third layer, the fiber properties remained approximately the same to those of the control. In addition, three-point bending tests indicated that the 3D aramid composite had an increase of 11% in flexural strength and 12% in flexural modulus after the plasma treatment. These results indicate that composite mechanical properties can be improved by the direct fabric treatment instead of fiber treatment with plasmas if the fabric is less than four layers thick.

  5. Plasma etching a ceramic composite. [evaluating microstructure

    Science.gov (United States)

    Hull, David R.; Leonhardt, Todd A.; Sanders, William A.

    1992-01-01

    Plasma etching is found to be a superior metallographic technique for evaluating the microstructure of a ceramic matrix composite. The ceramic composite studied is composed of silicon carbide whiskers (SiC(sub W)) in a matrix of silicon nitride (Si3N4), glass, and pores. All four constituents are important in evaluating the microstructure of the composite. Conventionally prepared samples, both as-polished or polished and etched with molten salt, do not allow all four constituents to be observed in one specimen. As-polished specimens allow examination of the glass phase and porosity, while molten salt etching reveals the Si3N4 grain size by removing the glass phase. However, the latter obscures the porosity. Neither technique allows the SiC(sub W) to be distinguished from the Si3N4. Plasma etching with CF4 + 4 percent O2 selectively attacks the Si3N4 grains, leaving SiC(sub W) and glass in relief, while not disturbing the pores. An artifact of the plasma etching reaction is the deposition of a thin layer of carbon on Si3N4, allowing Si3N4 grains to be distinguished from SiC(sub W) by back scattered electron imaging.

  6. Evaluation of lead isotope compositions of NIST NBS 981 measured by thermal ionization mass spectrometer and multiple-collector inductively coupled plasma mass spectrometer

    Directory of Open Access Journals (Sweden)

    Honglin Yuan

    2016-09-01

    Full Text Available Because Pb isotopes can be used for tracing, they are widely used in many disciplines. The detection and analysis of Pb isotopes of bulk samples are usually conducted using thermal ionization mass spectrometer (TIMS and multiple-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, both of which need external reference materials with known isotopic compositions to correct for the mass discrimination effect produced during analysis. NIST NBS 981 is the most widely used reference material for Pb isotope analysis; however, the isotopic compositions reported by various analytical laboratories, especially those using TIMS, vary from each other. In this study, we statistically evaluated 229 reported TIMS analysis values collected by GeoReM in the last 30 years, 176 reported MC-ICP-MS analysis values, and 938 MC-ICP-MS analysis results from our laboratory in the last five years. After careful investigation, only 40 TIMS results were found to have double or triple spikes. The ratios of the overall weighted averages, 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb, obtained from 40 spiked TIMS reports and 1114 MC-ICP-MS results of NIST NBS 981 isotopes were 16.9406 ± 0.0003 (2s, 15.4957 ± 0.0002 (2s, and 36.7184 ± 0.0007 (2s, respectively.

  7. Nanostructured Sulfide Composite Coating Prepared by Atmospheric Plasma Spraying

    Institute of Scientific and Technical Information of China (English)

    关耀辉

    2006-01-01

    Nanostructured FeS-SiC coating was deposited by atmospheric plasma spraying (APS). The microstructure and phase composition of the coating were characterized with SEM and XRD, respectively. In addition, the size distribution of the reconstituted powders and the porosity of the coating have been measured. It was found that the reconstitiuted powers with sizes in the range of 20 to 80 μm had excellent flowability and were suitable for plasma spraying process. The assprayed FeS-SiC composite coating exhibited a bimodal distribution with small grains (30~80nm) and large grains (100~200nm). The coating was mainly composed of FeS and SiC, a small quantity of Fe1-x S and oxide were also found. The porosity of the coating was approximately 19 %.

  8. Hollow ballistic pendulum for plasma momentum measurements

    Science.gov (United States)

    Goncharov, S. F.; Pashinin, P. P.; Perov, V. Y.; Serov, R. V.; Yanovsky, V. P.

    1988-05-01

    A novel pendulum design—hollow ballistic pendulum—is suggested for plasma momentum measurements. It has an advantage over the pendula used earlier in laser plasma experiments of being insensitive to a momentum of matter evaporated and scattered by the pendulum wall exposed to the plasma, which usually exceeds plasma momentum to be measured. Simple expressions describing pendulum performance are derived, and requirements of shape and size are established. Using this kind of pendulum in experiments on laser acceleration of thin foils made it possible to measure the momentum of accelerated foil with an accuracy of about 10%.

  9. Io Plasma Torus Ion Composition: Voyager, Galileo, Cassini

    Science.gov (United States)

    Bagenal, Fran; Nerney, Edward; Steffl, Andrew Joseph

    2016-10-01

    With JAXA's Hisaki spacecraft in orbit around Earth gathering information on the Io plasma torus and NASA's Juno mission measuring plasma conditions in the jovian magnetosphere, the time is ripe for a re-evaluation of earlier observations of the plasma torus to assess evidence for temporal variations. In particular, we are interested in exploring the ion composition of the torus and whether there is evidence of the ultimate source – the volcanic gases from Io – have deviated from SO2. We use the latest CHIANTI 8.0 atomic database to analyze UV spectra of the torus from Voyager, Galileo and Cassini as well as with the physical chemistry model of Delamere, Steffl and Bagenal (2005). We find that contrary to earlier analyses of Voyager data (e.g. Shemansky 1987; 1988) that produced a composition requiring a neutral source of O/S~4, we find an ion composition that is consistent with the Cassini UVIS data (Steffl et al. 2004) and a neutral O/S~2, consistent with SO2.

  10. Interferometer measurements in pulsed plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lisitsyn, I.V.; Kohno, Susumu; Kawauchi, Toshinori; Sueda, Tsuyoshi; Katsuki, Sunao; Akiyama, Hidenori [Kumamoto Univ. (Japan). Faculty of Engineering

    1997-11-01

    The interferometer measurements are extremely informative in plasma experiments allowing direct evaluations of the electron density. The primary goal of the work presented, is to build a laser interferometer which meets the requirements of the highest possible simplicity, economy, convenience and ease of construction. These requirements are successfully satisfied while maintaining high sensitivity ({+-}0.5deg - of phase shift) and a wide density range (10{sup 14} and 10{sup 19} cm{sup -2} - line-integrated) of the interferometer. In our experiments we used a low average power (5 mW) He-Ne laser without complicated and costly stabilization or detection environments. The He-Ne laser interferometer with the Michelson arrangement was used to measure the line-integrated plasma densities in various plasma experiments. Time- and spatially-resolved density measurements were performed for a plasma opening switch, a laser produced plasma, an electrothermal launcher and railgun plasmas. (author)

  11. Design and testing of miniaturized plasma sensor for measuring hypervelocity impact plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Goel, A., E-mail: ashish09@stanford.edu; Tarantino, P. M.; Lauben, D. S.; Close, S. [Department of Aeronautics and Astronautics, Stanford University, Stanford, California 94305 (United States)

    2015-04-15

    An increasingly notable component of the space environment pertains to the impact of meteoroids and orbital debris on spacecraft and the resulting mechanical and electrical damages. Traveling at speeds of tens of km/s, when these particles, collectively referred to as hypervelocity particles, impact a satellite, they vaporize, ionize, and produce a radially expanding plasma that can generate electrically harmful radio frequency emission or serve as a trigger for electrostatic discharge. In order to measure the flux, composition, energy distribution, and temperature of ions and electrons in this plasma, a miniaturized plasma sensor has been developed for carrying out in-situ measurements in space. The sensor comprises an array of electrostatic analyzer wells split into 16 different channels, catering to different species and energy ranges in the plasma. We present results from numerical simulation based optimization of sensor geometry. A novel approach of fabricating the sensor using printed circuit boards is implemented. We also describe the test setup used for calibrating the sensor and show results demonstrating the energy band pass characteristics of the sensor. In addition to the hypervelocity impact plasmas, the plasma sensor developed can also be used to carry out measurements of ionospheric plasma, diagnostics of plasma propulsion systems, and in other space physics experiments.

  12. Design and testing of miniaturized plasma sensor for measuring hypervelocity impact plasmas

    Science.gov (United States)

    Goel, A.; Tarantino, P. M.; Lauben, D. S.; Close, S.

    2015-04-01

    An increasingly notable component of the space environment pertains to the impact of meteoroids and orbital debris on spacecraft and the resulting mechanical and electrical damages. Traveling at speeds of tens of km/s, when these particles, collectively referred to as hypervelocity particles, impact a satellite, they vaporize, ionize, and produce a radially expanding plasma that can generate electrically harmful radio frequency emission or serve as a trigger for electrostatic discharge. In order to measure the flux, composition, energy distribution, and temperature of ions and electrons in this plasma, a miniaturized plasma sensor has been developed for carrying out in-situ measurements in space. The sensor comprises an array of electrostatic analyzer wells split into 16 different channels, catering to different species and energy ranges in the plasma. We present results from numerical simulation based optimization of sensor geometry. A novel approach of fabricating the sensor using printed circuit boards is implemented. We also describe the test setup used for calibrating the sensor and show results demonstrating the energy band pass characteristics of the sensor. In addition to the hypervelocity impact plasmas, the plasma sensor developed can also be used to carry out measurements of ionospheric plasma, diagnostics of plasma propulsion systems, and in other space physics experiments.

  13. The AMPTE/CCE Hot-Plasma Composition Experiment (HPCE)

    Science.gov (United States)

    Shelley, E. G.; Ghielmetti, A.; Hertzberg, E.; Battel, S. J.; Altwegg-Von Burg, K.; Balsiger, H.

    1985-01-01

    The Hot-Plasma Composition Experiment (HPCE) on the AMPTE-CCE spacecraft consists of an energetic ions-mass spectrometer and an electron background-environment monitor (EBEM). The mass spectrometer covers the entire mass per charge range from below 1 to greater than 150 amu/e and the energy per charge range from 0 eV/e (spacecraft potential) to 17 keV/e. The EBEM measures electrons between 50 eV and 25 keV in eight broad energy bands. The ion and electron data are processed into color spectrogram formats for the data pool.

  14. The AMPTE/CCE Hot-Plasma Composition Experiment (HPCE)

    Science.gov (United States)

    Shelley, E. G.; Ghielmetti, A.; Hertzberg, E.; Battel, S. J.; Altwegg-von Burg, K.; Balsiger, H.

    1985-05-01

    The Hot-Plasma Composition Experiment (HPCE) on the AMPTE-CCE spacecraft consists of an energetic ions-mass spectrometer and an electron background-environment monitor (EBEM). The mass spectrometer covers the entire mass per charge range from below 1 to greater than 150 amu/e and the energy per charge range from 0 eV/e (spacecraft potential) to 17 keV/e. The EBEM measures electrons between 50 eV and 25 keV in eight broad energy bands. The ion and electron data are processed into color spectrogram formats for the data pool.

  15. Plasma Diagnostics by Antenna Impedance Measurements

    Science.gov (United States)

    Swenson, C. M.; Baker, K. D.; Pound, E.; Jensen, M. D.

    1993-01-01

    The impedance of an electrically short antenna immersed in a plasma provides an excellent in situ diagnostic tool for electron density and other plasma parameters. By electrically short we mean that the wavelength of the free-space electromagnetic wave that would be excited at the driving frequency is much longer than the physical size of the antenna. Probes using this impedance technique have had a long history with sounding rockets and satellites, stretching back to the early 1960s. This active technique could provide information on composition and temperature of plasmas for comet or planetary missions. Advantages of the impedance probe technique are discussed and two classes of instruments built and flown by SDL-USU for determining electron density (the capacitance and plasma frequency probes) are described.

  16. Composition of Plasma Formed from Hypervelocity Dust Impacts

    Science.gov (United States)

    Lee, N.; Close, S.; Rymer, A. M.; Mocker, A.

    2012-12-01

    Dust impacts can occur on all solar system bodies but are especially prevalent in the case of the Saturnian moons that are near or within the dust torus produced by Enceladus's plumes. Depending on the mass and charge on these plume particles, they will be influenced by both gravitational and electrodynamic forces, resulting in a range of possible impact speeds on the moons. The plasma formed upon impact can have very different characteristics depending on impact speed and on the electric field due to surface charging at the impact point. Through recent tests conducted at the Max Planck Institute for Nuclear Physics using a Van de Graaff dust accelerator, iron dust particles were electrostatically accelerated to speeds of 3-65 km/s and impacted on a variety of target materials including metallic and glassy surfaces. The target surfaces were connected to a biasing supply to represent surface charging effects. Because of the high specific kinetic energy of the dust particles, upon impact they vaporize along with part of the target surface and a fraction of this material is ionized forming a dense plasma. The impacts produced both positive and negative ions. We made measurements of the net current imparted by this expanding plasma at a distance of several centimeters from the impact point. By setting the bias of the target, we impose an electric field on the charge population, allowing a measurement of plasma composition through time of flight analysis. The figure shows representative measurements of the net current measured by a retarding potential analyzer (RPA) from separate 18 and 19 km/s impacts of 7 fg particles on a glassy surface that was negatively and positively biased, respectively. This target was an optical solar reflector donated by J. Likar of Lockheed Martin for these experiments. These results show that ions of both positive and negative charge can be formed through the mechanism of dust impacts, and has implications on the surface plasma environment

  17. Composition measurements in the dusk flank magnetosphere

    Science.gov (United States)

    Fuselier, S. A.; Elphic, R. C.; Gosling, J. T.

    1999-03-01

    The dusk flank magnetosphere exhibits significant structure. Several regions have been identified, including the plasma sheet, mantle, and low latitude boundary layer. Transitions from one region to the next, for example from the mantle to the plasma sheet, can be abrupt or indistinct. In addition, the density within the flank mantle can range over several orders of magnitude. Although there is significant structure in this region of the magnetosphere, individual regions often can be distinguished by their energy spectra and ion composition. ISEE Fast Plasma Experiment and Plasma Composition Experiment data are used to examine the composition of the mantle and to study a set of transitions from the mantle to the plasma sheet where plasmas with mantle-like and plasma sheet-like energies mix. This study indicates that the variability of the mantle density is largely due to variability in the solar wind component (H+ and He2+); the ionospheric plasma (O+) density is roughly constant. Similarly, the plasma with mantle-like energy found in the mixed region is largely of solar wind origin.

  18. Measurements of an expanding surface flashover plasma

    Energy Technology Data Exchange (ETDEWEB)

    Harris, J. R., E-mail: john.harris@colostate.edu [Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2014-05-21

    A better understanding of vacuum surface flashover and the plasma produced by it is of importance for electron and ion sources, as well as advanced accelerators and other vacuum electronic devices. This article describes time-of-flight and biased-probe measurements made on the expanding plasma generated from a vacuum surface flashover discharge. The plasma expanded at velocities of 1.2–6.5 cm/μs, and had typical densities of 10{sup 10}–10{sup 12} cm{sup −3}. The expansion velocity of the plasma leading edge often exhibited a sharp increase at distances of about 50 mm from the discharge site. Comparison with biased-probe data suggests that, under most conditions, the plasma leading edge was dominated by negative ions, with the apparent increase in velocity being due to fast H{sup −} overtaking slower, heavier ions. In some cases, biased-probe data also showed abrupt discontinuities in the plasma energy distribution co-located with large changes in the intercepted plasma current, suggesting the presence of a shock in the leading edge of the expanding plasma.

  19. Composite wire plasma formation and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Spielman, R.B.

    2000-01-01

    The detailed understanding of the formation and evolution of plasma from rapidly heated metallic wires is a long-standing challenge in the field of plasma physics and in exploding wire engineering. This physical process is made even more complicated if the wire material is composed of a number of individual layers. The authors have successfully developed both optical and x-ray backlighting diagnostics. In particular, the x-ray backlighting technique has demonstrated the capability for quantitative determination of the plasma density over a wide range of densities. This diagnostic capability shows that the process of plasma formation is composed of two separate phases: first, current is passed through a cold wire and the wire is heated ohmically, and, second, the heated wire evolves gases that break down and forms a low-density plasma surrounding the wire.

  20. Thomson Scattering Measurements of Plasma Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Holl, A; Redmer, R; Tschentscher, T; Toleikis, S; Forster, E; Cao, L; Glenzer, S H; Neumayer, P

    2006-03-29

    The authors propose to investigate the dynamics of plasmas in the warm dense matter (WDM) regime on ultra-short time scales. Accessible plasma conditions are in the density range of n = 10{sup 20} - 10{sup 23} cm{sup -3} and at moderate temperatures of T = 1 - 20 eV. These plasmas are of importance for laboratory astrophysics, high energy density science and inertial confinement fusion. They are characterized by a coupling parameter of {Lambda} {approx}> 1, where electromagnetic interactions are of the same order as the kinetic energy. The high density of the plasma makes it opaque to radiation in the visible range and, as a consequence, UV up to x-ray radiation can be used to probe such systems. Therefore a wide range in the temperature-density plane of WDM is presently unexplored and only the VUV-FEL opens for the first time the opportunity for its detailed investigation. In equilibrium, the macroscopic state of the plasma is completely characterized by its density and temperature. In pump-probe experiments however, the plasma is initially in a nonequilibrium state and relaxes towards equilibrium within the relaxation time {tau}{sub R}. For t > {tau}{sub R}, the plasma is in an equilibrium state and expands hydrodynamically on a time scale {tau}{sub H}. The proposed experiment measures the time-resolved Thomson scattering signal with the VUV-FEL radiation characterizing the plasma in equilibrium and nonequilibrium states. Both regimes are extremely interesting and will provide new insight into the following phenomena: (1) details of nonequilibrium correlations, (2) relaxation phenomena, (3) hydrodynamic expansion, (4) recombination kinetics. The time-resolved Thomson scattering signal is obtained in a pump-probe experiment by varying the delay between pump and probe. The final stage of the relaxation process (t {approx} {tau}{sub R}) is of special interest since the plasma components (electrons and ion species) can be assumed to be in quasi-equilibrium. This

  1. Io plasma torus ion composition: Voyager, Galileo, and Cassini

    Science.gov (United States)

    Nerney, Edward G.; Bagenal, Fran; Steffl, Andrew J.

    2017-01-01

    The Io torus produces ultraviolet emissions diagnostic of plasma conditions. We revisit data sets obtained by the Voyager 1, Galileo, and Cassini missions at Jupiter. With the latest version (8.0) of the CHIANTI atomic database we analyze UV spectra to determine ion composition. We compare ion composition obtained from observations from these three missions with a theoretical model of the physical chemistry of the torus by Delamere et al. (2005). We find ion abundances from the Voyager data similar to the Cassini epoch, consistent with the dissociation and ionization of SO2, but with a slightly higher average ionization state for sulfur, consistent with the higher electron temperature measured by Voyager. This reanalysis of the Voyager data produces a much lower oxygen:sulfur ratio than earlier analysis by Shemansky (1988), which was also reported by Bagenal (1994). We derive fractional ion compositions in the center of the torus to be S+/Ne 5%, S++/Ne 20%, S+++/Ne 5%, O+/Ne 20%, O++/Ne 3%, and Σ(On+)/Σ(Sn+) 0.8, leaving about 10-15% of the charge as protons. The radial profile of ion composition indicates a slightly higher average ionization state, a modest loss of sulfur relative to oxygen, and Σ(On+)/Σ(Sn+) 1.2 at about 8 RJ, beyond which the composition is basically frozen in. The Galileo observations of UV emissions from the torus suggest that the composition in June 1996 may have comprised a lower abundance of oxygen than usual, consistent with observations made at the same time by the EUVE satellite.

  2. Application of atmospheric pressure plasma in polymer and composite adhesion

    Science.gov (United States)

    Yu, Hang

    An atmospheric pressure helium and oxygen plasma was used to investigate surface activation and bonding in polymer composites. This device was operated by passing 1.0-3.0 vol% of oxygen in helium through a pair of parallel plate metal electrodes powered by 13.56 or 27.12 MHz radio frequency power. The gases were partially ionized between the capacitors where plasma was generated. The reactive species in the plasma were carried downstream by the gas flow to treat the substrate surface. The temperature of the plasm gas reaching the surface of the substrate did not exceed 150 °C, which makes it suitable for polymer processing. The reactive species in the plasma downstream includes ~ 1016-1017 cm-3 atomic oxygen, ~ 1015 cm-3 ozone molecule, and ~ 10 16 cm-3 metastable oxygen molecule (O2 1Deltag). The substrates were treated at 2-5 mm distance from the exit of the plasma. Surface properties of the substrates were characterized using water contact angle (WCA), atomic force microscopy (AFM), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). Subsequently, the plasma treated samples were bonded adhesively or fabricated into composites. The increase in mechanical strength was correlated to changes in the material composition and structure after plasma treatment. The work presented hereafter establishes atmospheric pressure plasma as an effective method to activate and to clean the surfaces of polymers and composites for bonding. This application can be further expanded to the activation of carbon fibers for better fiber-resin interactions during the fabrication of composites. Treating electronic grade FR-4 and polyimide with the He/O2 plasma for a few seconds changed the substrate surface from hydrophobic to hydrophilic, which allowed complete wetting of the surface by epoxy in underfill applications. Characterization of the surface by X-ray photoelectron spectroscopy shows formation of oxygenated functional groups, including hydroxyl, carbonyl, and

  3. Effect of plasma nitriding on electrodeposited Ni–Al composite coating

    DEFF Research Database (Denmark)

    Daemi, N.; Mahboubi, F.; Alimadadi, Hossein

    2011-01-01

    In this study plasma nitriding is applied on nickel–aluminum composite coating, deposited on steel substrate. Ni–Al composite layers were fabricated by electro-deposition process in Watt’s bath containing Al particles. Electrodeposited specimens were subjected to plasma atmosphere comprising of N2......–20% H2, at 500°C, for 5h. The surface morphology investigated, using a scanning electron microscope (SEM) and the surface roughness was measured by use of contact method. Chemical composition was analyzed by X-ray fluorescence spectroscopy and formation of AlN phase was confirmed by X-ray diffraction....... The corrosion resistance of composite coatings was measured by potentiodynamic polarization in 3.5% NaCl solution. The obtained results show that plasma nitriding process leads to an increase in microhardness and corrosion resistance, simultaneously....

  4. Modelling of a Multi-Temperature Plasma Composition

    Institute of Scientific and Technical Information of China (English)

    B. Liani; R.Benallal; Z.Bentalha

    2005-01-01

    @@ Knowledge of plasma composition is very important for various plasma applications and prediction of plasma properties. We use the Saha equation and Debye length equation to calculate the non-local thermodynamicequilibrium plasma composition. It has been shown that the model to 2T with T representing the temperature (electron temperature and heavy-particle temperature) described by Chen and Han [J. Phys. D 32 (1999)1711]can be applied for a mixture of gases, where each atomic species has its own temperature, but the model to 4T is more general because it can be applicable to temperatures distant enough of the heavy particles. This can occur in a plasma composed of big- or macro-molecules. The electron temperature Te varies in the range 8000*20000 K at atmospheric pressure.

  5. Inductive Measurement of Plasma Jet Electrical Conductivity

    Science.gov (United States)

    Turner, Matthew W.; Hawk, Clark W.; Litchford, Ron J.

    2005-01-01

    An inductive probing scheme, originally developed for shock tube studies, has been adapted to measure explosive plasma jet conductivities. In this method, the perturbation of an applied magnetic field by a plasma jet induces a voltage in a search coil, which, in turn, can be used to infer electrical conductivity through the inversion of a Fredholm integral equation of the first kind. A 1-inch diameter probe was designed and constructed, and calibration was accomplished by firing an aluminum slug through the probe using a light-gas gun. Exploratory laboratory experiments were carried out using plasma jets expelled from 15-gram high explosive shaped charges. Measured conductivities were in the range of 3 kS/m for unseeded octol charges and 20 kS/m for seeded octol charges containing 2% potassium carbonate by mass.

  6. Online compositional analysis in coal gasification environment using laser-induced plasma technology

    Science.gov (United States)

    Deng, Kung-Li; Wu, Juntao; Wang, Zhe; Lee, Boon; Guida, Renato

    2006-08-01

    Integrated Gasification Combined Cycle (IGCC) power plants have great potential for future clean-coal power generation. Today, the quality of coal is measured by sampling coal using various offline methods, and the syn-gas composition is determined by taking samples downstream of the gasifier and measured by gas chromatograph (GC). Laser induced plasma technology has demonstrated high sensitivity for elementary detection. The capability of free space transmission and focusing of laser beam makes laser induced plasma a unique technology for online compositional analysis in coal gasification environment and optimization control.

  7. ISEE-1 data reduction and analysis plasma composition experiment

    Science.gov (United States)

    Lennartsson, W.; Sharp, R. D.

    1985-01-01

    The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given.

  8. ISEE-1 data reduction and analysis plasma composition experiment

    Science.gov (United States)

    Lennartsson, W.; Sharp, R. D.

    1985-03-01

    The plasma composition experiment covers energies from OeV to 17 keV/e and has a mass-per-charge range from less than 1 to about 150 amu. Measurements were made from the inner ring current region to the plasma sheet, magnetotail lobes, and the magnetopause boundary layers and beyond. Possibly the most significant results from the experiment are those related to energetic (0+) ions of terrestrial origin. These ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions that are similar to those traditionally associated with protons of solar wind origin. The (0+) ions are commonly the most numerous ions in the 0.1 - 17 keV/e energy range and are often a substantial part of the ion population at large distances as well, especially during geomagnetically disturbed conditions. An overview of results obtained for the (0+) and other ions with energies in the 0.1 - 17 keV/e range in the magnetosphere is given.

  9. Comparison of plasma sheet ion composition with the IMF and solar wind plasma

    Science.gov (United States)

    Lennartsson, W.

    Plasma sheet energetic ion data (0.1- to 16 keV/e) obtained by the Plasma Composition Experiment on ISEE-1 between 10 and 23 earth radii are compared with concurrent IMF and solar wind plasma data. The densities of H(+) and He(++) ions in the plasma sheet are found to be the highest, and the most nearly proportional to the solar wind density, when the IMF B(z) is not northward. The density of terrestrial O(+) ions increases strongly with increasing magnitude of the IMF, in apparent agreement with the notion that the IMF plays a fundamental role in the electric coupling between the solar wind and the ionosphere.

  10. Preparation of silver-carbon nanotubes composites with plasma electrochemistry

    Science.gov (United States)

    Hoefft, Oliver; Lohmann, Lara; Olschewski, Mark; Endres, Frank

    2016-09-01

    Plasma electrochemistry is a powerful tool to generate free nanoparticles in aqueous solutions and especially in ionic liquids (ILs). Due to their very low vapour pressure, ionic liquids can be employed under vacuum conditions as fluid substrates or solvents. Thus, ionic liquids are well suitable electrolytes for plasma electrochemical processes delivering stable and homogeneous plasmas. We have shown that free copper and germanium nanoparticles can be obtained in ILs by applying a plasma as a mechanically contact-free electrode. Here we present our results using an argon plasma for the electrochemical synthesis of silver on pure and pre-treated multiwall carbon nanotubes (MWCNTs) in 1-ethyl-3-methylimidazolium dicyanamide. For the pre-treatment of the MWCNTS we have used a dielectric barrier discharge plasma (DBD) at atmospheric pressure. For the untreated MWCNTs we have found a formation of free silver nanoparticles between, on and in the vicinity of the carbon nanotubes. In case of the plasma treated MWCNTs a silver-carbon nanotubes composite is formed. Thus, the treatment of the MWCNTs obviously has a great influence on the deposit. Therefore we additionally have investigated the influence of the DBD on the chemical composition of the MWCNTs surface with X-Ray Photoelectron Spectroscopy.

  11. Composition and thermodynamic properties of dense alkali metal plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Gabdullin, M.T. [NNLOT, al-Farabi Kazakh National University, 71 al-Farabi Str., Almaty 050035 (Kazakhstan); Ramazanov, T.S.; Dzhumagulova, K.N. [IETP, al-Farabi Kazakh National University, 71 al-Farabi Str., Almaty 050035 (Kazakhstan)

    2012-04-15

    In this work composition and thermodynamic properties of dense alkali metal plasmas (Li, Na) were investigated. Composition was derived by solving the Saha equations with corrections due to nonideality. The lowering of the ionization potentials was calculated on the basis of pseudopotentials by taking screening and quantum effects into account (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Plasma Density Measurements on Refuelling by Solid Hydrogen Pellets in a Rotating Plasma

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, A. H.

    1978-01-01

    The authors used laser interferometry to directly measure the increase in plasma density caused by the ablation of a solid hydrogen pellet situated in a rotating plasma.......The authors used laser interferometry to directly measure the increase in plasma density caused by the ablation of a solid hydrogen pellet situated in a rotating plasma....

  13. Surface compositional changes in GaAs subjected to argon plasma treatment

    Energy Technology Data Exchange (ETDEWEB)

    Surdu-Bob, C.C.; Sullivan, J.L.; Saied, S.O.; Layberry, R.; Aflori, M

    2002-12-30

    X-ray photoelectron spectroscopy (XPS) has been employed to study surface compositional changes in GaAs (1 0 0) subjected to argon plasma treatment. The experimental results have been explained in terms of predicted argon ion energies, measured ion densities and etch rates. A model is proposed for the processes taking place at the surface of GaAs in terms of segregation, sputtering and surface relaxation. Stopping and range of ions in matter (SRIM) code has also been employedan aid to identification of the mechanisms responsible for the compositional changes. Argon plasma treatment induced surface oxidation at very low energies and sputtering and surface damage with increasing energy.

  14. Tungsten-microdiamond composites for plasma facing components

    Science.gov (United States)

    Livramento, V.; Nunes, D.; Correia, J. B.; Carvalho, P. A.; Mardolcar, U.; Mateus, R.; Hanada, K.; Shohoji, N.; Fernandes, H.; Silva, C.; Alves, E.

    2011-09-01

    Tungsten is considered as one of promising candidate materials for plasma facing component in nuclear fusion reactors due to its resistance to sputtering and high melting point. High thermal conductivity is also a prerequisite for plasma facing components under the unique service environment of fusion reactor characterised by the massive heat load, especially in the divertor area. The feasibility of mechanical alloying of nanodiamond and tungsten, and the consolidation of the composite powders with Spark Plasma Sintering (SPS) was previously demonstrated. In the present research we report on the use of microdiamond instead of nanodiamond in such composites. Microdiamond is more favourable than nanodiamond in view of phonon transport performance leading to better thermal conductivity. However, there is a trade off between densification and thermal conductivity as the SPS temperature increases tungsten carbide formation from microdiamond is accelerated inevitably while the consolidation density would rise.

  15. Effect of Electrolyte Composition on Characteristics of Plasma Electrolysis Nitrocarburizing

    Science.gov (United States)

    Tavakoli, H.; Mousavi Khoie, S. M.; Marashi, S. P. H.; Bolhasani, O.

    2013-08-01

    In this article, the effect of electrolyte composition on the characteristics of generated layer by plasma electrolytic nitrocarburizing process is studied. The characterization of the layer was carried out by means of SEM, x-ray diffraction, and EIS techniques. The relationship between workpiece temperature and the chemical composition of electrolyte was determined during the process. Three distinct regions in the temperature-voltage curves were observed. The effect of electrolyte's composition on the electrical parameters such as critical voltage, voltage of plasma formation, current density, and electrolyte conductivity was investigated. XRD studies showed that in addition to nitride phases, Fe3O4 phase also is generated. Moreover, EIS studies indicated that the corrosion resistance of the samples processed with higher water contents is less than the samples processed with lower water contents.

  16. Sensor platform for gas composition measurement

    NARCIS (Netherlands)

    De Graaf, G.; Bakker, F.; Wolffenbuttel, R.F.

    2011-01-01

    The gas sensor research presented here has a focus on the measurement of the composition of natural gas and gases from sustainable resources, such as biogas. For efficient and safe combustion, new sensor systems need to be developed to measure the composition of these new gases. In general about 6 g

  17. Compton scattering measurements from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Glenzer, S H; Neumayer, P; Doeppner, T; Landen, L; Lee, R W; Wallace, R; Weber, S; Lee, H J; Kritcher, A L; Falcone, R; Regan, S P; Sawada, H; Meyerhofer, D D; Gregori, G; Fortmann, C; Schwarz, V; Redmer, R

    2007-10-02

    Compton scattering has been developed for accurate measurements of densities and temperatures in dense plasmas. One future challenge is the application of this technique to characterize compressed matter on the National Ignition Facility where hydrogen and beryllium will approach extremely dense states of matter of up to 1000 g/cc. In this regime, the density, compressibility, and capsule fuel adiabat may be directly measured from the Compton scattered spectrum of a high-energy x-ray line source. Specifically, the scattered spectra directly reflect the electron velocity distribution. In non-degenerate plasmas, the width provides an accurate measure of the electron temperatures, while in partially Fermi degenerate systems that occur in laser-compressed matter it provides the Fermi energy and hence the electron density. Both of these regimes have been accessed in experiments at the Omega laser by employing isochorically heated solid-density beryllium and moderately compressed beryllium foil targets. In the latter experiment, compressions by a factor of 3 at pressures of 40 Mbar have been measured in excellent agreement with radiation hydrodynamic modeling.

  18. Compton scattering measurements from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Glenzer, S H; Neumayer, P; Doeppner, T; Landen, O L; Lee, R W; Wallace, R J; Weber, S [Lawrence Livermore National Laboratory, Livermore, CA (United States); Lee, H J; Kritcher, A L; Falcone, R [University of California Berkeley, Berkeley, CA 94709 (United States); Regan, S P; Sawada, H; Meyerhofer, D D [Laboratory for Laser Energetics, Rochester, NY (United States); Gregori, G [Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom); Fortmann, C; Schwarz, V; Redmer, R [Institut fuer Physik, Universitaet Rostock, D-18051 Rostock (Germany)], E-mail: glenzer1@llnl.gov

    2008-05-15

    Compton scattering techniques have been developed for accurate measurements of densities and temperatures in dense plasmas. One future challenge is the application of this technique to characterize compressed matter on the National Ignition Facility where hydrogen and beryllium will approach extremely dense states of matter of up to 1000 g/cc. In this regime, the density, compressibility, and capsule fuel adiabat may be directly measured from the Compton scattered spectrum of a high-energy x-ray line source. Specifically, the scattered spectra directly reflect the electron velocity distribution. In non-degenerate plasmas, the width provides an accurate measure of the electron temperatures, while in partially Fermi degenerate systems that occur in laser-compressed matter it provides the Fermi energy and hence the electron density. Both of these regimes have been accessed in experiments at the Omega laser by employing isochorically heated solid-density beryllium and moderately compressed beryllium foil targets. In the latter experiment, compressions by a factor of 3 at pressures of 40 Mbar have been measured in excellent agreement with radiation hydrodynamic modeling.

  19. Low temperature spark plasma sintering of TC4/HA composites

    Institute of Scientific and Technical Information of China (English)

    Huiliang Shao; Lei Cao; Daqian Sun; Zhankui Zhao

    2016-01-01

    Ti6Al4V/hydroxyapatite composites (TC4/HA) have been prepared by high energy ball milling and low temperature spark plasma sintering at 600 °C, 550 °C, 500 °C and 450 °C, respectively. The sintering temperature of the composites was sharply decreased as the result of the activation and surficial modification effects induced from high energy ball milling. The decomposition and reaction of hydro-xyapatite was successfully avoided, which offers the composites superior biocompatibility. The hydro-xyapatite in the composites was distributed in gap uniformly, and formed an ideal network structure. The lowest hardness, compressive strength and Young's modulus of the composites satisfy the requirements of human bone.

  20. ECE Measurements of Helical Plasmas in LHD

    Science.gov (United States)

    Nagayama, Y.; Inagaki, S.; Ito, Y.; Kawahata, K.; Sasao, H.; de Vries, P.

    1999-11-01

    This paper presents ECE measurements on LHD, which is the l=2, n=10 heriotron with the major radius of 3.8 m, with the averaged minor radius of 60 cm and with the helical field of up to 3 T. The ECE is collected from both inner and outer sides, since the magnetic field has a peaked profile. ECE is detcted with Michelson, GPC and 70 GHz and 140 GHz radiometers. The LHD plasma is generated using ECH of up to 1 MW and is heated using NBI of up to 8 GW. Notch filters reduce the ECH leakage. The polarization of ECE is theoretically and experimentally investigated in the heriotoron system, where the field angle rotates -30 to 30^o. The polarization follows as the field angle changes. Since the density profile is flat, ECE is cut off in the edge region in the high density LHD plasma. An interesting observation is the breathing phenomena, which is as follows: the electron temperature and other plasma parameters oscillate with frequency of 0.5-1Hz like a sine-wave when the NBI power is about 1 MW.

  1. Atmospheric pressure plasma assisted calcination of composite submicron fibers

    Science.gov (United States)

    Medvecká, Veronika; Kováčik, Dušan; Tučeková, Zlata; Zahoranová, Anna; Černák, Mirko

    2016-08-01

    The plasma assisted calcination of composite organic/inorganic submicron fibers for the preparation of inorganic fibers in submicron scale was studied. Aluminium butoxide/polyvinylpyrrolidone fibers prepared by electrospinning were treated using low-temperature plasma generated by special type of dielectric barrier discharge, so called diffuse coplanar surface barrier discharge (DCSBD) at atmospheric pressure in ambient air, synthetic air, oxygen and nitrogen. Effect of plasma treatment on base polymer removal was investigated by using Attenuated total reflectance - Fourier transform infrared (ATR-FTIR) spectroscopy. Influence of working gas on the base polymer reduction was studied by energy-dispersive X-ray spectroscopy (EDX) and CHNS elemental analysis. Changes in fibers morphology were observed by scanning electron microscopy (SEM). High efficiency of organic template removal without any degradation of fibers was observed after plasma treatment in ambient air. Due to the low-temperature approach and short exposure time, the plasma assisted calcination is a promising alternative to the conventional thermal calcination. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  2. Interpreting Power Anisotropy Measurements in Plasma Turbulence

    CERN Document Server

    Chen, C H K; Horbury, T S; Schekochihin, A A

    2009-01-01

    A relationship between power anisotropy and wavevector anisotropy in turbulent fluctuations is derived. This can be used to interpret plasma turbulence measurements, for example in the solar wind. If fluctuations are anisotropic in shape then the ion gyroscale break point in spectra in the directions parallel and perpendicular to the magnetic field would not occur at the same frequency, and similarly for the electron gyroscale break point. This is an important consideration when interpreting solar wind observations in terms of anisotropic turbulence theories. Model magnetic field power spectra are presented assuming a cascade of critically balanced Alfven waves in the inertial range and kinetic Alfven waves in the dissipation range. The variation of power anisotropy with scale is compared to existing solar wind measurements and the similarities and differences are discussed.

  3. Effects of non-thermal atmospheric pressure pulsed plasma on the adhesion and durability of resin composite to dentin.

    Science.gov (United States)

    Han, Geum-Jun; Kim, Jae-Hoon; Chung, Sung-No; Chun, Bae-Hyeock; Kim, Chang-Keun; Seo, Deog-Gyu; Son, Ho-Hyun; Cho, Byeong-Hoon

    2014-12-01

    This study investigated the effect of low-power, non-thermal atmospheric pressure plasma (NT-APP) treatments, in pulsed and conventional modes, on the adhesion of resin composite to dentin and on the durability of the bond between resin composite and dentin. A pencil-type NT-APP jet was applied in pulsed and conventional modes to acid-etched dentin. The microtensile bond strength (MTBS) of resin composite to dentin was evaluated at 24 h and after thermocycling in one control group (no plasma) and in two experimental groups (pulsed plasma and conventional plasma groups) using the Scotchbond Multi-Purpose Plus Adhesive System. Data were analyzed using two-factor repeated-measures anova and Weibull statistics. Fractured surfaces and the bonded interfaces were evaluated using a field-emission scanning electron microscope. Although there were no significant differences between the plasma treatment groups, the plasma treatment improved the MTBS compared with the control group. After thermocycling, the MTBS did not decrease in the control or conventional plasma group but increased in the pulsed plasma group. Thermocycling increased the Weibull moduli of plasma-treated groups. In conclusion, plasma treatment using NT-APP improved the adhesion of resin composite to dentin. Using a pulsed energy source, the energy delivered to the dentin was effectively reduced without any reduction in bond strength or durability.

  4. Modification of the composite multi-layer oxide ceramic coating on meteoroid shielding element by compression plasma flow

    Science.gov (United States)

    Astashinski, V. M.; Khramtsov, P. P.; Hryshchanka, U. M.; Chernik, M. Yu; Vasetskij, V. A.; Shikh, I. A.; Doroshko, M. V.; Makhnach, A. I.

    2016-11-01

    The aim of this work is investigation of the influence of high-energy plasma impact on composite multi-layer coating (NiAl as a sublayer and Al2O3 as a top coat) on meteoroid shielding element. In order to reach this goal qausi-stationary plasma accelerator with impulse gas feeding was used. Experiments were conducted with use of helium and hydrogen gas mixture and nitrogen as plasma forming substance. Plasma accelerator generates plasma jet with electron temperature ≈ 150 kK and electron density (2.5-4) × 1016 cm-3. Visual examination, photography and spectral measurements were made through special vacuum chamber optical windows.

  5. Suspension plasma sprayed composite coating using amorphous powder feedstock

    Science.gov (United States)

    Chen, Dianying; Jordan, Eric H.; Gell, Maurice

    2009-03-01

    Al 2O 3-ZrO 2 composite coatings were deposited by the suspension plasma spray process using molecularly mixed amorphous powders. X-ray diffraction (XRD) analysis shows that the as-sprayed coating is composed of α-Al 2O 3 and tetragonal ZrO 2 phases with grain sizes of 26 nm and 18 nm, respectively. The as-sprayed coating has 93% density with a hardness of 9.9 GPa. Heat treatment of the as-sprayed coating reveals that the Al 2O 3 and ZrO 2 phases are homogeneously distributed in the composite coating.

  6. Rotation Rate of Saturn's Magnetosphere using CAPS Plasma Measurements

    Science.gov (United States)

    Sittler, E.; Cooper, J.; Hartle, R.; Simpson, D.; Johnson, R.; Thomsen, M.; Arridge, C.

    2011-01-01

    We present the present status of an investigation of the rotation rate of Saturn's magnetosphere using a 3D velocity moment technique being developed at Goddard which is similar to the 2D version used by Sittler et al. for SOI and similar to that used by Thomsen et al.. This technique allows one to nearly cover the full energy range of the Cassini Plasma Spectrometer (CAPS) IMS from 1 V . E/Q work during roll maneuvers. We make comparisons with the bi-Maxwellian fitting technique developed by Wilson et al. and the similar velocity moment technique by Thomsen et al. . We concentrate our analysis when ion composition data is available, which is used to weight the non-compositional data, referred to as singles data, to separate H+, H2+ and water group ions (W+) from each other. The chosen periods have high enough telemetry rates (4 kbps or higher) so that coincidence ion data, similar to that used by Sittler et al. for SOI is available. The ion data set is especially valuable for measuring flow velocities for protons, which are more difficult to derive using singles data within the inner magnetosphere, where the signal is dominated by heavy ions (i.e., proton peak merges with W+ peak as low energy shoulder). Our technique uses a flux function, which is zero in the proper plasma flow frame, to estimate fluid parameter uncertainties. The comparisons investigate the experimental errors and potential for systematic errors in the analyses, including ours. The rolls provide the best data set when it comes to getting 4PI coverage of the plasma but are more susceptible to time aliasing effects. In the future we will then make comparisons with magnetic field observations, Saturn ionosphere conductivities as presently known and the field aligned currents necessary for the planet to enforce corotation of the rotating plasma.

  7. Principles of fuel ion ratio measurements in fusion plasmas by collective Thomson scattering

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Nielsen, Stefan Kragh; Bindslev, Henrik;

    2011-01-01

    ratio. Measurements of the fuel ion ratio will be important for plasma control and machine protection in future experiments with burning fusion plasmas. Here we examine the theoretical basis for fuel ion ratio measurements by CTS. We show that the sensitivity to plasma composition is enhanced......For certain scattering geometries collective Thomson scattering (CTS) measurements are sensitive to the composition of magnetically confined fusion plasmas. CTS therefore holds the potential to become a new diagnostic for measurements of the fuel ion ratio—i.e. the tritium to deuterium density...... by the signatures of ion cyclotron motion and ion Bernstein waves which appear for scattering geometries with resolved wave vectors near perpendicular to the magnetic field. We investigate the origin and properties of these features in CTS spectra and give estimates of their relative importance for fuel ion ratio...

  8. An Investigation on the Microstructure of Multi-phase Composite Coatings Synthesized by Plasma Spraying Self-reaction Composite Powders

    Institute of Scientific and Technical Information of China (English)

    DONGYan-chun; YANDian-ran; HeJi-ning; LiXiang-zhi; ZHANGJian-xin; NIUEr-wu

    2004-01-01

    Multi-phase self-reacLion composite (denoted as MPc) coatings containing ceramic and metal multi-phases were fabricated by plasma spraying Fe2O3-Al composite powders. This technology successfully combines self-propagating high-temperature synthesis with plasma spraying. The morphology of the composite powders was examined by scanning electron microscope (SEM). The phase composition and microstructure of the composite coating are studied.

  9. An Investigation on the Microstructure of Multi-phase Composite Coatings Synthesized by Plasma Spraying Self-reaction Composite Powders

    Institute of Scientific and Technical Information of China (English)

    DONG Yan-chun; YAN Dian-ran; HE Ji-ning; LI Xiang-zhi; ZHANG Jian-xin; NIU Er-wu

    2004-01-01

    Multi-phase self-reaction composite (denoted as MPc) coatings containing ceramic and metal multi-phases were fabricated by plasma spraying Fe2O3-Al composite powders. This technology successfully combines self-propagating high-temperature synthesis with plasma spraying. The morphology of the composite powders was examined by scanning electron microscope (SEM). The phase composition and microstructure of the composite coating are studied.

  10. Plasma-activated multi-walled carbon nanotube-polystyrene composite substrates for biosensing

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Sanchez, Cesar; Orozco, Jahir; Jimenez-Jorquera, Cecilia [Instituto de Microelectronica de Barcelona, IMB-CNM (CSIC), Campus UAB, E-08193 Bellaterra, Barcelona (Spain); Pellicer, Eva; Lechuga, Laura M; Mendoza, Ernest, E-mail: cesar.fernandez@imb-cnm.csic.e [Nanobiosensors and Molecular Nanobiophysics Group, Research Center on Nanoscience and Nanotechnology (CIN2) CSIC-ICN, ETSE, Campus UAB-Edificio Q, E-08193 Bellaterra, Barcelona (Spain)

    2009-08-19

    Carbon nanotube-polymer composites have shown to be suitable materials for the fabrication of electrochemical transducers. The exposed surface of these materials is commonly passivated by a very thin layer of the polymer component that buries the conductive carbon particles. Working with multi-walled carbon nanotube-polystyrene (MWCNT-PS) composite structures, it was previously described how a simple low power oxygen plasma process produced an effective etching of the composite surface, thereby exposing the conductive surface of CNTs. This work shows how this plasma process not only gave rise to a suitable composite conductive surface for electrochemical sensing but simultaneously exposed and created a high density of oxygen-containing functional groups at both the CNT and the PS components, without affecting the material's mechanical stability. These chemical groups could be effectively modified for the stable immobilization of biological receptors. A detailed chemical characterization of the plasma-activated composite surface was possible using x-ray photoelectron spectroscopy. The material reactivity towards the tethering of a protein was studied and protein-protein interactions were then evaluated on the modified composite transducers by scanning electron microscopy. Finally, an amperometric immunosensor approach for the detection of rabbit Immunoglobulin G target analyte was described and a minimum concentration of 3 ng ml{sup -1} was easily measured.

  11. On Improving Impedance Probe Plasma Potential Measurements

    Science.gov (United States)

    2014-02-21

    assumption of a collisionless, stationary Maxwellian plasma and are seen to work well in non -flowing plasmas of sufficient density. However, as plasma...collection area. For Maxwellian electrons, np = n exp(Vp-φp)/Te and so at low frequency from Eq. (1) above, the resistive component of the ac

  12. Plasma sintering of Fe-NbC composites

    Energy Technology Data Exchange (ETDEWEB)

    Paulo, D.S.; Martinelli, A.E.; Alves, C. Jr.; Assuncao, C.A.M.; Tavora, M.P. [Univ. Federal do Rio Grande do Norte, Programa de Doutorado em Ciencia e Engenharia de Materiais, Campus, Natal, RN (Brazil); Echude-Silva, J.H. [Univ. Federal da Paraiba, Dept. de Engenharia Mecanica, Joao Pessoa, PB (Brazil)

    2003-07-01

    Ferrous alloys have been reinforced by particle dispersion using hard ceramics such as niobium carbide, tantalum carbide, or titanium carbide. The resulting composites have a number of potential applications in the ceramic and textile fields where abrasion plays an important role. Their cost-efficient production allows them to exceed the capabilities of conventional non-reinforced tool steels. The present study presents some of the results obtained sintering Fe-NbC composites either in a resistive oven or in a d.c. plasma furnace. Final densities of approximately 95% TD were obtained in the latter atmosphere at temperatures as low as 750 C. Dilatometric studies carried out in resistive furnace indicated that this composite did not show significant densification below 1240 C in the presence of a liquid phase formed by the addition of small amounts of Fe{sub 3}P. The differences between conventional and plasma sintering are discussed herein along with the effect on the microstructure of the composite. (orig.)

  13. Electron Temperature and Plasma Flow Measurements of NIF Hohlraum Plasmas

    Science.gov (United States)

    Barrios, M. A.; Liedahl, D. A.; Schneider, M. B.; Jones, O.; Brow, G. V.; Regan, S. P.; Fournier, K. B.; Moore, A. S.; Ross, J. S.; Eder, D.; Landen, O.; Kauffman, R. L.; Nikroo, A.; Kroll, J.; Jaquez, J.; Huang, H.; Hansen, S. B.; Callahan, D. A.; Hinkel, D. E.; Bradley, D.; Moody, J. D.; LLNL Collaboration; LLE Collaboration; GA Collaboration; SNL Collaboration

    2016-10-01

    Characterizing the plasma conditions inside NIF hohlraums, in particular mapping the plasma Te, is critical to gaining insight into mechanisms that affect energy coupling and transport in the hohlraum. The dot spectroscopy platform provides a temporal history of the localized Te and plasma flow inside a NIF hohlraum, by introducing a Mn-Co tracer dot, at strategic locations inside the hohlraum, that comes to equilibrium with the local plasma. K-shell X-ray spectroscopy of the tracer dot is recorded onto an absolutely calibrated X-ray streak spectrometer. Isoelectronic and interstage line ratios are used to infer localized Te through comparison with atomic physics calculations using SCRAM. Time resolved X-ray images are simultaneously taken of the expanding dot, providing plasma (ion) flow information. We present recent results provided by this platform and compare with simulations using HYDRA. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  14. Microwave Measurements of Ferrite Polymer Composite Materials

    Directory of Open Access Journals (Sweden)

    Rastislav Dosoudil

    2004-01-01

    Full Text Available The article focuses on the microwave measurements performed on the nickel-zinc sintered ferrite with the chemical formula Ni0.3Zn0.7Fe2O4 produced by the ceramic technique and composite materials based on this ferrite and a non-magnetic polymer (polyvinyl chloride matrix. The prepared composite samples had the same particle size distribution 0-250um but different ferrite particle concentrations between 23 vol% and 80 vol%. The apparatus for measurement of the signal proportional to the absolute value of scattering parameter S11 (reflexion coefficient is described and the dependence of measured reflected signal on a bias magnetic field has been studied. By means of experiments, the resonances to be connected with the geometry of microwave experimental set-up were distinguished from ferromagnetic resonance arising in ferrite particles of composite structure. The role of local interaction fields of ferrite particles in composite material has been discussed.

  15. Determination of metals in composite diet samples by inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Melnyk, Lisa Jo; Morgan, Jeffrey N; Fernando, Reshan; Pellizzari, Edo D; Akinbo, Olujide

    2003-01-01

    A study was conducted to evaluate the applicability of inductively coupled plasma-mass spectrometry (ICP-MS) techniques for determination of metals in composite diets. Aluminum, cadmium, chromium, copper, lead, manganese, nickel, vanadium, and zinc were determined by this method. Atmospheric pressure microwave digestion was used to solubilize analytes in homogenized composite diet samples, and this procedure was followed by ICP-MS analysis. Recovery of certified elements from standard reference materials ranged from 92 to 119% with relative standard deviations (RSDs) of 0.4-1.9%. Recovery of elements from fortified composite diet samples ranged from 75 to 129% with RSDs of 0-11.3%. Limits of detection ranged from 1 to 1700 ng/g; high values were due to significant amounts of certain elements naturally present in composite diets. Results of this study demonstrate that low-resolution quadrupole-based ICP-MS provides precise and accurate measurements of the elements tested in composite diet samples.

  16. Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Bhabesh Kumar; Khan, Aziz; Chutia, Joyanti, E-mail: jchutiaiasst@gmail.com

    2015-10-15

    Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm{sup −1}. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm{sup −2}. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm{sup −1} which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm{sup −2} and current density of 0.62 A cm{sup −2} at 0.6 V.

  17. Oxygen plasma treatments of jute fibers in improving the mechanical properties of jute/HDPE composites

    Energy Technology Data Exchange (ETDEWEB)

    Sever, K. [Department of Mechanical Engineering, Dokuz Eylul University, 35100, Izmir (Turkey); Erden, S. [Department of Mechanical Engineering, Ege University, 35100, Izmir (Turkey); Guelec, H.A. [Department of Food Engineering, Yuzuncu Yil University, 65250, Van (Turkey); Seki, Y., E-mail: yoldas.seki@deu.edu.tr [Department of Chemistry, Dokuz Eylul University, 35160, Buca, Izmir (Turkey); Sarikanat, M. [Department of Mechanical Engineering, Ege University, 35100, Izmir (Turkey)

    2011-09-15

    Highlights: {yields} To improve mechanical properties of jute/HDPE composites, jute fabric was subjected to oxygen plasma treatment. {yields} LF and RF plasma systems at different plasma powers were used for treatment. {yields} In LF system, interlaminar shear strength, tensile and flexure strengths showed a tendency to increase at plasma powers of 30 and 60 W. - Abstract: The surfaces of jute fabrics have been oxygen plasma treated using low frequency (LF) and radio frequency (RF) plasma systems at different plasma powers (30, 60, and 90 W) for 15 min to improve the mechanical properties of jute fiber/HDPE (high density polyethylene) composites. The effect of oxygen plasma treatment on the functional groups of jute fibers was examined by X-ray photoelectron spectroscopy (XPS) analysis. Effects of oxygen plasma treatments on the mechanical properties of jute fiber/HDPE composites were investigated by means of tensile, flexure, and short-beam shear tests. Surface morphology of the fractured surfaces of composites was observed by using scanning electron microscopy (SEM). When RF plasma system was used, the interlaminar shear strength (ILSS) values of the composites increased with increasing plasma power. Similarly, in LF plasma system, ILSS values showed a tendency to increase at plasma powers of 30 and 60 W. However, increasing of plasma power to 90 W decreased the ILSS value of jute/HDPE composite. Also, tensile and flexure strengths of the composites showed similar trends.

  18. Stratospheric composition from balloon based measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mencaraglia, F.; Carli, B. [Ist. per le Ricerche sulle Onde Elettromagnetiche, Firenze (Italy); Bonetti, A.; Ciarpallini, P. [Univ. di Firenze (Italy); Carlotti, M.; Lepri, G. [Univ. di Bologna (Italy); Alboni, F.; Cortesi, U.; Ridolfi, M. [Fondazione per la Metereologia Applicata, Firenze (Italy)

    1995-12-31

    Measurements of the composition of the earth`s atmosphere is of fundamental importance for the study of atmospheric chemistry and for developing models that can predict the evolution of the atmosphere itself. Here, the chemical composition of the lower stratosphere has been measured using a polarizing interferometer operating in the far infrared and submillimetric spectral region. The instrument was flown three times (in 1992, 1993 and 1994) from the NSBF balloon base (Fort Sumner, New Mexico) in coincidence with overpasses of the UARS satellite, for a total of about 50 hours of measurements. In this paper the authors report some of the results obtained from the data analysis made up to now.

  19. Carbon fiber composites application in ITER plasma facing components

    Science.gov (United States)

    Barabash, V.; Akiba, M.; Bonal, J. P.; Federici, G.; Matera, R.; Nakamura, K.; Pacher, H. D.; Rödig, M.; Vieider, G.; Wu, C. H.

    1998-10-01

    Carbon Fiber Composites (CFCs) are one of the candidate armour materials for the plasma facing components of the International Thermonuclear Experimental Reactor (ITER). For the present reference design, CFC has been selected as armour for the divertor target near the plasma strike point mainly because of unique resistance to high normal and off-normal heat loads. It does not melt under disruptions and might have higher erosion lifetime in comparison with other possible armour materials. Issues related to CFC application in ITER are described in this paper. They include erosion lifetime, tritium codeposition with eroded material and possible methods for the removal of the codeposited layers, neutron irradiation effect, development of joining technologies with heat sink materials, and thermomechanical performance. The status of the development of new advanced CFCs for ITER application is also described. Finally, the remaining R&D needs are critically discussed.

  20. Contemporary methods of body composition measurement

    DEFF Research Database (Denmark)

    Fosbøl, Marie Ø; Zerahn, Bo

    2015-01-01

    . This review is focused on currently applied methods for in vivo measurement of body composition, including densitometry, bioimpedance analysis, dual-energy X-ray absorptiometry, computed tomography (CT), magnetic resonance techniques and anthropometry. Multicompartment models including quantification of trace......Reliable and valid body composition assessment is important in both clinical and research settings. A multitude of methods and techniques for body composition measurement exist, all with inherent problems, whether in measurement methodology or in the assumptions upon which they are based...... elements by in vivo neutron activation analysis, which are regarded as gold standard methods, are also summarized. The choice of a specific method or combination of methods for a particular study depends on various considerations including accuracy, precision, subject acceptability, convenience, cost...

  1. Suspension plasma sprayed composite coating using amorphous powder feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dianying [Department of Chemical, Materials and Biomolecular Engineering, Institute of Materials Science, University of Connecticut, 97 N Eagleville Rd U-3136, Storrs, CT 06269 (United States)], E-mail: chendy@ims.uconn.edu; Jordan, Eric H. [Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269 (United States); Gell, Maurice [Department of Chemical, Materials and Biomolecular Engineering, Institute of Materials Science, University of Connecticut, 97 N Eagleville Rd U-3136, Storrs, CT 06269 (United States)

    2009-03-15

    Al{sub 2}O{sub 3}-ZrO{sub 2} composite coatings were deposited by the suspension plasma spray process using molecularly mixed amorphous powders. X-ray diffraction (XRD) analysis shows that the as-sprayed coating is composed of {alpha}-Al{sub 2}O{sub 3} and tetragonal ZrO{sub 2} phases with grain sizes of 26 nm and 18 nm, respectively. The as-sprayed coating has 93% density with a hardness of 9.9 GPa. Heat treatment of the as-sprayed coating reveals that the Al{sub 2}O{sub 3} and ZrO{sub 2} phases are homogeneously distributed in the composite coating.

  2. Apparent Surface Free Energy of Polymer/Paper Composite Material Treated by Air Plasma

    Directory of Open Access Journals (Sweden)

    Konrad Terpiłowski

    2017-01-01

    Full Text Available Surface plasma treatment consists in changes of surface properties without changing internal properties. In this paper composite polymer/paper material is used for production of packaging in cosmetic industry. There are problems with bonding this material at the time of packaging production due to its properties. Composite surface was treated by air plasma for 1, 10, 20, and 30 s. The advancing and receding contact angles of water, formamide, and diiodomethane were measured using both treated and untreated samples. Apparent surface free energy was estimated using the hysteresis (CAH and Van Oss, Good, Chaudhury approaches (LWAB. Surface roughness was investigated using optical profilometry and identification of after plasma treatment emerging chemical groups was made by means of the XPS (X-ray photoelectron spectroscopy technique. After plasma treatment the values of contact angles decreased which is particularly evident for polar liquids. Apparent surface free energy increased compared to that of untreated samples. Changes of energy value are due to the electron-donor parameter of energy. This parameter increases as a result of adding polar groups at the time of surface plasma activation. Changes of surface properties are combination of increase of polar chemical functional groups, increase on the surface, and surface roughness increase.

  3. W/Cu composites produced by pulse plasma sintering technique (PPS)

    Energy Technology Data Exchange (ETDEWEB)

    Rosinski, M. [Association EURATOM-IPPLM, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland); Fortuna, E. [Association EURATOM-IPPLM, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)], E-mail: elaf@inmat.pw.edu.pl; Michalski, A.; Pakiela, Z.; Kurzydlowski, K.J. [Association EURATOM-IPPLM, Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warsaw (Poland)

    2007-10-15

    W-Cu composites of various compositions were produced using the pulse plasma sintering (PPS) technique which applies pulsed high electric discharges to heat the powders subjected to pressing. Because the arc discharges between the powder particles clean their surfaces and intensify diffusion processes, the sintering time is reduced to a few minutes. The powder preparation processes, milling, mixing and reduction before sintering, and the sintering conditions were optimized by undertaking detailed investigations of the microstructure of powders and composites. Room temperature tensile strength, using small samples, hardness and the coefficients of thermal expansion were measured. The results prove that by using the PPS method a high density material having 98% of the theoretical density can be fabricated. It has also been shown that the PPS device can be used to join the composite material to a tungsten plate.

  4. Plasma scattering of electromagnetic radiation theory and measurement techniques

    CERN Document Server

    Froula, Dustin H; Luhmann, Neville C Jr; Sheffield, John

    2011-01-01

    This work presents one of the most powerful methods of plasma diagnosis in exquisite detail to guide researchers in the theory and measurement techniques of light scattering in plasmas. Light scattering in plasmas is essential in the research and development of fusion energy, environmental solutions, and electronics.Referred to as the "Bible" by researchers the work encompasses fusion and industrial applications essential in plasma research. It is the only comprehensive resource specific to the plasma scattering technique. It provides a wide-range of experimental examples and discussion of the

  5. Measurement of Body Composition in Children.

    Science.gov (United States)

    Lohman, T. G.

    1982-01-01

    Identification and treatment of obesity in children is believed to be an important factor in its control during the adult years. Laboratory and field methods for body composition measurement are described along with estimates of body fat content from anthropometric dimensions. (CJ)

  6. Preparation and Performance of Plasma/Polymer Composite Coatings on Magnesium Alloy

    Science.gov (United States)

    Bakhsheshi-Rad, H. R.; Hamzah, E.; Bagheriyan, S.; Daroonparvar, M.; Kasiri-Asgarani, M.; Shah, A. M.; Medraj, M.

    2016-09-01

    A triplex plasma (NiCoCrAlHfYSi/Al2O3·13%TiO2)/polycaprolactone composite coating was successfully deposited on a Mg-1.2Ca alloy by a combination of atmospheric plasma spraying and dip-coating techniques. The NiCoCrAlHfYSi (MCrAlHYS) coating, as the first layer, contained a large number of voids, globular porosities, and micro-cracks with a thickness of 40-50 μm, while the Al2O3·13%TiO2 coating, as the second layer, presented a unique bimodal microstructure with a thickness of 70-80 μm. The top layer was a hydrophobic polymer, which effectively sealed the porosities of plasma layers. The results of micro-hardness and bonding strength tests showed that the plasma coating presented excellent hardness (870 HV) and good bonding strength (14.8 MPa). However, the plasma/polymer coatings interface exhibited low bonding strength (8.6 MPa). The polymer coating formed thick layer (100-110 μm) that homogeneously covered the surface of the plasma layers. Contact angle measurement showed that polymer coating over plasma layers significantly decreased surface wettability. The corrosion current density ( i corr) of an uncoated sample (262.7 µA/cm2) decreased to 76.9 µA/cm2 after plasma coatings were applied. However, it was found that the i corr decreased significantly to 0.002 µA/cm2 after polymer sealing of the porous plasma layers.

  7. Methods for nurses to measure body composition.

    Science.gov (United States)

    Moran, Jose Maria; Lavado-Garcia, Jesus Maria; Pedrera-Zamorano, Juan Diego

    2011-01-01

    Among the methods available for assessing body composition, traditional methods like hydrodensitometry and skin-fold measurements are well known. In this review, we focus on the impedance and interactance methods, which use systems that are usually inexpensive, easily transportable and simple to operate. We also discuss the usefulness of dual energy X-ray absorptiometry, particularly for the measurement of fat distribution. Nurses need to be skilled in the use of the equipment and familiar with the techniques.

  8. Spectroscopic measurements of plasma emission light for plasma-based acceleration experiments

    Science.gov (United States)

    Filippi, F.; Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Zigler, A.

    2016-09-01

    Advanced particle accelerators are based on the excitation of large amplitude plasma waves driven by either electron or laser beams. Future experiments scheduled at the SPARC_LAB test facility aim to demonstrate the acceleration of high brightness electron beams through the so-called resonant Plasma Wakefield Acceleration scheme in which a train of electron bunches (drivers) resonantly excites wakefields into a preformed hydrogen plasma; the last bunch (witness) injected at the proper accelerating phase gains energy from the wake. The quality of the accelerated beam depends strongly on plasma density and its distribution along the acceleration length. The measurements of plasma density of the order of 1016-1017 cm-3 can be performed with spectroscopic measurements of the plasma-emitted light. The measured density distribution for hydrogen filled capillary discharge with both Balmer alpha and Balmer beta lines and shot-to-shot variation are here reported.

  9. Plasma actuator electron density measurement using microwave perturbation method

    Energy Technology Data Exchange (ETDEWEB)

    Mirhosseini, Farid; Colpitts, Bruce [Electrical and Computer Engineering, University of New Brunswick, Fredericton, New Brunswick E3B 5A3 (Canada)

    2014-07-21

    A cylindrical dielectric barrier discharge plasma under five different pressures is generated in an evacuated glass tube. This plasma volume is located at the center of a rectangular copper waveguide cavity, where the electric field is maximum for the first mode and the magnetic field is very close to zero. The microwave perturbation method is used to measure electron density and plasma frequency for these five pressures. Simulations by a commercial microwave simulator are comparable to the experimental results.

  10. Lamb-shift and electric field measurements in plasmas

    Science.gov (United States)

    Doveil, F.; Chérigier-Kovacic, L.; Ström, P.

    2017-01-01

    The electric field is a quantity of particular relevance in plasma physics. Indeed, its fluctuations are responsible for different macroscopic phenomena such as anomalous transport in fusion plasmas. Answering a long-standing challenge, we offer a new method to locally and non-intrusively measure weak electric fields and their fluctuations in plasmas, by means of a beam of hydrogen ions or atoms. We present measurements of the electric field in vacuum and in a plasma where Debye shielding is measured. For the first time, we have used the Lamb-shift resonance to measure oscillating electric fields around 1 GHz and observed the strong enhancement of the Lyman-α signal. The measurement is both direct and non-intrusive. This method provides sensitivity (mV cm-1) and temporal resolution (ns) that are three orders higher compared to current diagnostics. It thus allows measuring fluctuations of the electric field at scales not previously reached experimentally.

  11. Hemolysis interference in measuring fish plasma biochemical indicators.

    Science.gov (United States)

    Mirghaed, Ali Taheri; Ghelichpour, Melika; Hoseini, Seyyed Morteza; Amini, Kourosh

    2017-08-01

    The present study aimed to determine hemolysis interference in measurement of plasma biochemical parameters in fish specimens. For this purpose, blood samples were harvested from 24 Huso huso juveniles. After centrifugation, each plasma sample was divided into seven portions to make seven levels of hemolysis. Hemolysis was induced by addition of different percentages of the corresponding whole blood [0 (non-hemolyzed control group), 1, 3, 5, 10, 15, and 20% of whole blood]. Albumin, total protein, calcium, phosphorus, glucose, sodium, potassium, chloride, alkaline phosphatase (ALP), aspartate transaminase (AST), and alanine transaminase (ALT) were measured in different samples. Results showed that plasma albumin, ALP, potassium, and AST significantly increased (more than 200% at the highest hemolysis level) in the hemolyzed samples. Also, plasma total protein and phosphorus showed significant elevation in the hemolyzed samples (more than 70% at the highest hemolysis level). Plasma glucose, calcium, chloride, and ALT showed narrow but significant increase in hemolyzed samples (11.8-35.2% at the highest hemolysis level). Plasma sodium showed no significant changes in the hemolyzed samples. In conclusion, the present results show that hemolysis markedly affects plasma parameters levels, which interferes with plasma results interpretation. Therefore, analysis of hemolyzed samples should be avoided or the results should be interpreted with caution. This study encourages further investigations to develop methods for omitting the effects of hemolysis by sample blanking and/or presenting correction coefficients for measurement of plasma parameters in samples with different levels of hemolysis.

  12. Permeability measurement and control for epoxy composites

    Science.gov (United States)

    Chang, Tsun-Hsu; Tsai, Cheng-Hung; Wong, Wei-Syuan; Chen, Yen-Ren; Chao, Hsien-Wen

    2017-08-01

    The coupling of the electric and magnetic fields leads to a strong interplay in materials' permittivity and permeability. Here, we proposed a specially designed cavity, called the mu cavity. The mu cavity, consisting of a mushroom structure inside a cylindrical resonator, is exclusively sensitive to permeability, but not to permittivity. It decouples materials' electromagnetic properties and allows an accurate measurement of the permeability. With the help of an epsilon cavity, these two cavities jointly determine the complex permeability and permittivity of the materials at microwave frequencies. Homemade epoxy-based composite materials were prepared and tested. Measurement and manipulation of the permeability and permittivity of the epoxy composites will be shown. The results will be compared with the effective medium theories.

  13. Rotation Rate of Saturn's Magnetosphere using CAPS Plasma Measurements

    Science.gov (United States)

    Sittler, E.; Cooper, J.; Simpson, D.; Paterson, W.

    2012-01-01

    We present the present status of an investigation of the rotation rate of Saturn 's magnetosphere using a 3D velocity moment technique being developed at Goddard which is similar to the 2D version used by Sittler et al. (2005) [1] for SOI and similar to that used by Thomsen et al. (2010). This technique allows one to nearly cover the full energy range of the CAPS IMS from 1 V less than or equal to E/Q less than 50 kV. Since our technique maps the observations into a local inertial frame, it does work during roll manoeuvres. We have made comparisons with Wilson et al. (2008) [2] (2005-358 and 2005-284) who performs a bi-Maxwellian fit to the ion singles data and our results are nearly identical. We will also make comparisons with results by Thomsen et al. (2010) [3]. Our analysis uses ion composition data to weight the non-compositional data, referred to as singles data, to separate H+, H2+ and water group ions (W+) from each other. The ion data set is especially valuable for measuring flow velocities for protons, which are more difficult to derive using singles data within the inner magnetosphere, where the signal is dominated by heavy ions (i.e., proton peak merges with W+ peak as low energy shoulder). Our technique uses a flux function, which is zero in the proper plasma flow frame, to estimate fluid parameter uncertainties. The comparisons investigate the experimental errors and potential for systematic errors in the analyses, including ours. The rolls provide the best data set when it comes to getting 4PI coverage of the plasma but are more susceptible to time aliasing effects. Since our analysis is a velocity moments technique it will work within the inner magnetosphere where pickup ions are important and velocity distributions are non-Maxwellian. So, we will present results inside Enceladus' L shell and determine if mass loading is important. In the future we plan to make comparisons with magnetic field observations, use Saturn ionosphere conductivities as

  14. In situ impedance measurement of microwave atmospheric pressure plasma

    Science.gov (United States)

    Lee, S. T.; Nam, W. J.; Lee, J. K.; Yun, G. S.

    2017-04-01

    The impedance of atmospheric pressure argon plasma jets driven by microwave frequency is determined in situ by a novel ‘two frequency method’. In the conventional method of reflection coefficient ({{S}}11) measurement, the frequency of the driving microwave power is scanned, which inevitably affects the plasma characters and leads to uncertainty in the estimated plasma impedance. In our proposed method, the frequency-scanning signal additional to the driving power is used to measure {{S}}11 over a wide frequency range, which enables accurate determination of the plasma impedance based on an equivalent circuit model. The measured resistance and reactance of the plasma increase with the driving power in agreement with the transmission line theory. Based on this in situ measurement of the plasma impedance, the net power coupled to the plasma has been determined. The overall power efficiency remains approximately unchanged around 45% for different input power levels owing to the competing effects between the impedance mismatch and the volume change of the plasma.

  15. Toroidal and poloidal plasma rotation measurements in Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Hess, W.R.; Garbet, X.; Guirlet, R.; Hesse, M.; Payan, J. [Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    1993-12-31

    Plasma rotation measurements by visible spectroscopy and by a CO{sub 2}-laser scattering experiment (ALTAIR) are presented. The ALTAIR diagnostic is used to study the turbulence changes at the plasma edge during operation of the ergodic divertor (ED). Heterodyne detection allows discrimination between waves propagating in the electron or in the ion diamagnetic direction. (author) 6 refs., 4 figs.

  16. Electro-optic probe measurements of electric fields in plasmas

    Science.gov (United States)

    Nishiura, M.; Yoshida, Z.; Mushiake, T.; Kawazura, Y.; Osawa, R.; Fujinami, K.; Yano, Y.; Saitoh, H.; Yamasaki, M.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2017-02-01

    The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.

  17. Simplified method for calculation of equilibrium plasma composition

    Science.gov (United States)

    Rydalevskaya, Maria A.

    2017-06-01

    In this work, a simplified method for the evaluation of equilibrium composition of plasmas consisted of monoatomic species is proposed. Multicomponent gas systems resulting from thermal ionization of spatially uniform mixtures are assumed enough rarefied to be treated as ideal gases even after multiple ionization steps. The method developed for the calculation of equilibrium composition of these mixtures makes use of the fundamental principles of statistical physics. Equilibrium concentrations of mixture components are determined by integration of distribution functions over the space of momentum and summation over electronic energy levels. These functions correspond to the entropy maximum. To determine unknown parameters, the systems of equations corresponding to the normalization conditions are derived. It is shown that the systems may be reduced to one algebraic equation if the equilibrium temperature is known. Numeral method to solve this equation is proposed. Special attention is given to the ionized mixtures, generated from the atoms of a single chemical species and the situations, when in the gas only the first- or the first- and second-order ionization are possible.

  18. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  19. The effect of tuning cold plasma composition on glioblastoma cell viability.

    Directory of Open Access Journals (Sweden)

    Xiaoqian Cheng

    Full Text Available Previous research in cold atmospheric plasma (CAP and cancer cell interaction has repeatedly proven that the cold plasma induced cell death. It is postulated that the reactive oxygen species (ROS and reactive nitrogen species (RNS play a major role in the CAP cancer therapy. In this paper, we seek to determine a mechanism of CAP therapy on glioblastoma cells (U87 through an understanding of the composition of the plasma, including treatment time, voltage, flow-rate and plasma-gas composition. In order to determine the threshold of plasma treatment on U87, normal human astrocytes (E6/E7 were used as the comparison cell line. Our data showed that the 30 sec plasma treatment caused 3-fold cell death in the U87 cells compared to the E6/E7 cells. All the other compositions of cold plasma were performed based on this result: plasma treatment time was maintained at 30 s per well while other plasma characteristics such as voltage, flow rate of source gas, and composition of source gas were changed one at a time to vary the intensity of the reactive species composition in the plasma jet, which may finally have various effect on cells reflected by cell viability. We defined a term "plasma dosage" to summarize the relationship of all the characteristics and cell viability.

  20. Carbon fiber content measurement in composite

    Science.gov (United States)

    Wang, Qiushi

    Carbon fiber reinforced polymers (CFRPs) have been widely used in various structural applications in industries such as aerospace and automotive because of their high specific stiffness and specific strength. Their mechanical properties are strongly influenced by the carbon fiber content in the composites. Measurement of the carbon fiber content in CFRPs is essential for product quality control and process optimization. In this work, a novel carbonization-in-nitrogen method (CIN) is developed to characterize the fiber content in carbon fiber reinforced thermoset and thermoplastic composites. In this method, a carbon fiber composite sample is carbonized in a nitrogen environment at elevated temperatures, alongside a neat resin sample. The carbon fibers are protected from oxidization while the resin (the neat resin and the resin matrix in the composite sample) is carbonized under the nitrogen environment. The residue of the carbonized neat resin sample is used to calibrate the resin carbonization rate and calculate the amount of the resin matrix in the composite sample. The new method has been validated on several thermoset and thermoplastic resin systems and found to yield an accurate measurement of fiber content in carbon fiber polymer composites. In order to further understand the thermal degradation behavior of the high temperature thermoplastic polymer during the carbonization process, the mechanism and the kinetic model of thermal degradation behavior of carbon fiber reinforced poly (phenylene sulfide) (CPPS) are studied using thermogravimetry analysis (TGA). The CPPS is subjected to TGA in an air and nitrogen atmosphere at heating rates from 5 to 40°C min--1. The TGA curves obtained in air are different from those in nitrogen. This demonstrates that weight loss occurs in a single stage in nitrogen but in two stages in air. To elucidate this difference, thermal decomposition kinetics is analyzed by applying the Kissinger, Flynn-Wall-Ozawa, Coat-Redfern and

  1. A study of the formation and dynamics of the Earth's plasma sheet using ion composition data

    Science.gov (United States)

    Lennartsson, O. W.

    1994-01-01

    Over two years of data from the Lockheed Plasma Composition Experiment on the ISEE 1 spacecraft, covering ion energies between 100 eV/e and about 16 keV/e, have been analyzed in an attempt to extract new information about three geophysical issues: (1) solar wind penetration of the Earth's magnetic tail; (2) relationship between plasma sheet and tail lobe ion composition; and (3) possible effects of heavy terrestrial ions on plasma sheet stability.

  2. Measurement of Heat Propagation in a Laser Produced Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, G; Glenzer, S H; Knight, J; Niemann, C; Price, D; Froula, D H; Edwards, J; Town, R P J; Brantov, A; Bychenkov, V Y; Rozmus, W

    2003-08-22

    We present the observation of a nonlocal heat wave by measuring spatially and temporally resolved electron temperature profiles in a laser produced nitrogen plasma. Absolutely calibrated measurements have been performed by resolving the ion-acoustic wave spectra across the plasma volume with Thomson scattering. We find that the experimental electron temperature profiles disagree with flux-limited models, but are consistent with transport models that account for the nonlocal effects in heat conduction by fast electrons.

  3. Plasma absorption evidence via chirped pulse spectral transmission measurements

    Energy Technology Data Exchange (ETDEWEB)

    Jedrkiewicz, Ottavia, E-mail: ottavia.jedrkiewicz@ifn.cnr.it [Istituto di Fotonica e Nanotecnologie, CNR and CNISM UdR Como, Via Valleggio 11, I-22100 Como (Italy); Minardi, Stefano [Institute of Applied Physics, Friedrich-Schiller-University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Couairon, Arnaud; Jukna, Vytautas [Centre de Physique Theorique, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France); Selva, Marco; Di Trapani, Paolo [Dipartimento di Scienza e Alta Tecnologia, University of Insubria and CNISM UdR Como, Via Valleggio 11, I-22100 Como (Italy)

    2015-06-08

    This work aims at highlighting the plasma generation dynamics and absorption when a Bessel beam propagates in glass. We developed a simple diagnostics allowing us to retrieve clear indications of the formation of the plasma in the material, thanks to transmission measurements in the angular and wavelength domains. This technique featured by the use of a single chirped pulse having the role of pump and probe simultaneously leads to results showing the plasma nonlinear absorption effect on the trailing part of the pulse, thanks to the spectral-temporal correspondence in the measured signal, which is also confirmed by numerical simulations.

  4. Plasma Measurements: An Overview of Requirements and Status

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth M. Young

    2008-01-04

    This paper introduces this special issue on plasma diagnostics for magnetic fusion devices. Its primary purpose is to relate the measurements of plasma parameters to the physics challenges to be faced on operating and planned devices, and also to identify the diagnostic techniques that are used to make these measurements. The specific physics involved in the application of the techniques will be addressed in subsequent chapters. This chapter is biased toward measurements for tokamaks because of their proximity to the burning plasma frontier, and to set the scene for the development work associated with ITER. Hence, there is some emphasis on measurements for alpha-physics studies and the needs for plasma measurements as input to actuators to control the plasma, both for optimizing the device performance and for protection of the surrounding material. The very different approach to the engineering of diagnostics for a burning plasma is considered, emphasizing the needs for new calibration ideas, reliability and hardness against, and compatibility with, radiation. New ideas take a long time to be converted into "work-horse" sophisticated diagnostics so that investment in new developments is essential for ITER, particularly for the measurement of alpha-particles.

  5. Substorm effects on the plasma sheet on composition on March 22, 1979 (CDAW 6)

    Energy Technology Data Exchange (ETDEWEB)

    Lennartsson, W.; Sharp, R.D.; Zwickl, R.D.

    1985-02-01

    Data from the Plasma Composition Experiment on ISSE 1, covering the energy range 0.1--16 keV/e, show that a dramatic change took place in the plasma sheet ion composition in conjunction with the magnetic substorm activity on March 22, 1979. Beginning about 1124 UT the ion population at the ISEE 1 location changed from what appeared to be predominantly ions from the solar wind to a mixture of comparable numbers of solar wind and terrestrial ions. ISEE 1 was inbound in the predawn sector during this time, and the plasma composition experiment provided data from Rapprox. =21 R/sub E/ and LTapprox. =0130, down to Rapprox. =3 R/sub E/ and LTapprox. =0530. Prior to the substorm activity about 90--95% of the ion density was due to H/sup +/ and He/sup + +/ ions, which appeared to be mostly of solar wind origin. The H/sup +/ and He/sup + +/ components, each approximated by a Maxwell-Boltzmann distribution, had a temperature ratio T(He/sup + +/)/T(H/sup +/)approx. =4 and a density ratio n(He/sup + +/)/n(H/sup +/)approx. =1.5--3%. Both values are consistent with measurements made concurrently in the solar wind by the plasma experiment on ISSE 3. The remaining 5--10% of the density was due mainly to O/sup +/ and He/sup +/ ions of ionospheric origin. All four ion populations had broad energy spectra with mean energies of several keV/e.

  6. Tailored Net-Shape Powder Composites by Spark Plasma Sintering

    Science.gov (United States)

    Khaleghi, Evan Aryan

    This dissertation investigates the ability to produce net-shape and tailored composites in spark plasma sintering (SPS), with an analysis of how grain growth, densification, and mechanical properties are affected. Using alumina and four progressively anisotropic dies, we studied the impact of specimen shape on densification. We found specimen shape had an impact on overall densification, but no impact on localized properties. We expected areas of the specimen to densify differently, or have higher grain growth, based on current anisotropy in the specimen during sintering, and preliminary results indicated this, but further investigation showed this did not occur. Overall average grain size and porosity decreased as shape complexity increased. In Fe-V-C steel, we mechanical alloyed two rapidly solidified powders, and used spark sintering to retain the properties imparted during the rapid solidification. We noticed VC grains being produced during densification, which improved the final properties. We conducted spark plasma extrusion (SPE) of aluminum to understand the effect on microstructure. We found, through an analysis of the grain structure, that SPE did have a grain deformation potential, and grain size was severely decreased compared to conventional sintering. Dynamic recrystallization did not occur, due to the reduced temperatures we were able to extrude with SPS. Finally, we examined whether there were particular sintering conditions for SPS that reduced the complexity of the grain growth and porosity relationship to one similar to conventional sintering, of the form G = k G0 ε -1/. We found that although a reasonable case could be made for free sintering, as found in the literature, for hot-pressing and SPS the conditions required go against the common knowledge in grain growth and densification kinetics. We were able to fit our data very well to the model, but the correlated results do not make physical sense.

  7. Endocannabinoids concentrations in plasma associated with feed efficiency and carcass composition of beef steers.

    Science.gov (United States)

    Artegoitia, V M; Foote, A P; Lewis, R M; King, D A; Shackelford, S D; Wheeler, T L; Freetly, H C

    2016-12-01

    Endocannabinoids, including anandamide (AEA) and 2-arachidonoylglycerol (2-AG), are a class of endogenous lipid mediators that activate cannabinoids receptors and may be involved in the control of feed intake and energy metabolism. The objective of this study was to quantify AEA and 2-AG in plasma and identify possible associations with production traits and carcass composition in finishing beef steers. Individual DMI and BW gain were measured on 140 Angus-sired steers for 105 d on a finishing ration. Blood samples were collected on d 84 of the experiment, which was 40 d before slaughter. Variables were analyzed using Pearson CORR procedure of SAS. Mean endocannabinoid concentrations in plasma were 4.48 ± 1.82 ng/mL and 0.44 ± 0.24 ng/mL for AEA and 2-AG, respectively. The AEA concentration was positively correlated with G:F ratio ( = 0.20; = 0.02), indicating that more efficient animals had greater AEA plasma concentrations. In addition, AEA concentration tended to be negatively correlated with the 12th rib fat thickness ( = -0.17; = 0.07); but no correlation was found with USDA-calculated yield grade ( = -0.14; = 0.11), or marbling score ( = 0.05; = 0.54). The concentration of 2-AG was positively correlated with AEA ( = 0.21; = 0.01); however, 2-AG concentration was not correlated with parameters of feed efficiency or carcass composition. To our knowledge, this study is the first to report plasma concentration of endocannabinoids in steers. These results provide evidence that plasma concentration of a key endocannabinoid, AEA, was favorably correlated with feed efficiency and fat thickness in finishing steers.

  8. Wear behavior of gas tunnel type plasma sprayed Zr-based metallic glass composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Yugeswaran, S., E-mail: yugeswaran@gmail.com [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Kobayashi, A., E-mail: kobayasi@jwri.osaka-u.ac.jp [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Suresh, K., E-mail: ksureshphy@gmail.com [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region (China); Rao, K.P., E-mail: mekprao@cityu.edu.hk [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong Special Administrative Region (China); Subramanian, B., E-mail: subramanianb3@gmail.com [CSIR - Central Electrochemical Research Institute, Karaikudi 630 006 (India)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Zr-based metallic glass composite coatings are prepared by gas tunnel plasma torch. Black-Right-Pointing-Pointer Increasing plasma current increases crystallinity amount and hardness of coatings. Black-Right-Pointing-Pointer Coating produced at 300 A plasma current gives minimum sliding wear rate. Black-Right-Pointing-Pointer Coating produced at higher plasma current gives lower erosive wear rate. - Abstract: Gas tunnel type plasma spraying is a prospective method to produce metallic glass composite coatings with high quality due to its noteworthy feature of process controllability. In this study, Zr{sub 55}Cu{sub 30}Al{sub 10}Ni{sub 5} metallic glass composite coatings were produced by gas tunnel type plasma spraying torch under optimum spraying conditions with selected plasma currents. The formation mechanism, sliding, and erosive wear behaviors of the coatings with respect to plasma current was examined. The phase and thermal analyses as well as microstructure of the plasma sprayed coatings produced at different plasma currents were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) techniques. The sliding and erosive wear behaviors of the coatings were studied using a pin-on-disc and a specially designed erosive wear tester, respectively. The results showed that an increase in plasma current increased the crystalline content in the metallic glass composite coatings, which enhanced the hardness and wear resistance of the coatings.

  9. Testing THEMIS wave measurements against the cold plasma theory

    Science.gov (United States)

    Taubenschuss, Ulrich; Santolik, Ondrej; Le Contel, Olivier; Bonnell, John

    2016-04-01

    The THEMIS (Time History of Events and Macroscale Interactions during Substorms) mission records a multitude of electromagnetic waves inside Earth's magnetosphere and provides data in the form of high-resolution electric and magnetic waveforms. We use multi-component measurements of whistler mode waves and test them against the theory of wave propagation in a cold plasma. The measured ratio cB/E (c is speed of light in vacuum, B is magnetic wave amplitude, E is electric wave amplitude) is compared to the same quantity calculated from cold plasma theory over linearized Faraday's law. The aim of this study is to get estimates for measurement uncertainties, especially with regard to the electric field and the cold plasma density, as well as evaluating the validity of cold plasma theory inside Earth's radiation belts.

  10. Simulation of density measurements in plasma wakefields using photo acceleration

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Sadler, James; Burrows, Philip N; Trines, Raoul; Holloway, James; Wing, Matthew; Bingham, Robert; Norreys, Peter

    2015-01-01

    One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  11. Langmuir-Probe Measurements in Flowing-Afterglow Plasmas

    Science.gov (United States)

    Johnsen, R.; Shunko, E. V.; Gougousi, T.; Golde, M. F.

    1994-01-01

    The validity of the orbital-motion theory for cylindrical Langmuir probes immersed in flowing- afterglow plasmas is investigated experimentally. It is found that the probe currents scale linearly with probe area only for electron-collecting but not for ion-collecting probes. In general, no agreement is found between the ion and electron densities derived from the probe currents. Measurements in recombining plasmas support the conclusion that only the electron densities derived from probe measurements can be trusted to be of acceptable accuracy. This paper also includes a brief derivation of the orbital-motion theory, a discussion of perturbations of the plasma by the probe current, and the interpretation of plasma velocities obtained from probe measurements.

  12. Effect of Cold Plasma Treatment on the Mechanical Properties of RTM Composites

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Cold plasma technology was used to treat the surface of carbon fibers braided by PET in this paper and SEM wasused to analyze the fracture microstructure of composite interlaminar shear stress (ILSS). The result shows that thesurface polarity of carbon fibers was modified by cold plasma treatment, which increases the impregnation of PETbraided carbon fibers during the process of resin flowing, improves the interfacial properties of RTM composites, andtherefore enhances the mechanical properties of the KTM composites.

  13. A high sensitivity momentum flux measuring instrument for plasma thruster exhausts and diffusive plasmas

    Energy Technology Data Exchange (ETDEWEB)

    West, Michael D.; Charles, Christine; Boswell, Rod W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

    2009-05-15

    A high sensitivity momentum flux measuring instrument based on a compound pendulum has been developed for use with electric propulsion devices and radio frequency driven plasmas. A laser displacement system, which builds upon techniques used by the materials science community for surface stress measurements, is used to measure with high sensitivity the displacement of a target plate placed in a plasma thruster exhaust. The instrument has been installed inside a vacuum chamber and calibrated via two different methods and is able to measure forces in the range of 0.02-0.5 mN with a resolution of 15 {mu}N. Measurements have been made of the force produced from the cold gas flow and with a discharge ignited using argon propellant. The plasma is generated using a Helicon Double Layer Thruster prototype. The instrument target is placed about 1 mean free path for ion-neutral charge exchange collisions downstream of the thruster exit. At this position, the plasma consists of a low density ion beam (10%) and a much larger downstream component (90%). The results are in good agreement with those determined from the plasma parameters measured with diagnostic probes. Measurements at various flow rates show that variations in ion beam velocity and plasma density and the resulting momentum flux can be measured with this instrument. The instrument target is a simple, low cost device, and since the laser displacement system used is located outside the vacuum chamber, the measurement technique is free from radio frequency interference and thermal effects. It could be used to measure the thrust in the exhaust of other electric propulsion devices and the momentum flux of ion beams formed by expanding plasmas or fusion experiments.

  14. A high sensitivity momentum flux measuring instrument for plasma thruster exhausts and diffusive plasmas

    Science.gov (United States)

    West, Michael D.; Charles, Christine; Boswell, Rod W.

    2009-05-01

    A high sensitivity momentum flux measuring instrument based on a compound pendulum has been developed for use with electric propulsion devices and radio frequency driven plasmas. A laser displacement system, which builds upon techniques used by the materials science community for surface stress measurements, is used to measure with high sensitivity the displacement of a target plate placed in a plasma thruster exhaust. The instrument has been installed inside a vacuum chamber and calibrated via two different methods and is able to measure forces in the range of 0.02-0.5mN with a resolution of 15μN. Measurements have been made of the force produced from the cold gas flow and with a discharge ignited using argon propellant. The plasma is generated using a Helicon Double Layer Thruster prototype. The instrument target is placed about 1 mean free path for ion-neutral charge exchange collisions downstream of the thruster exit. At this position, the plasma consists of a low density ion beam (10%) and a much larger downstream component (90%). The results are in good agreement with those determined from the plasma parameters measured with diagnostic probes. Measurements at various flow rates show that variations in ion beam velocity and plasma density and the resulting momentum flux can be measured with this instrument. The instrument target is a simple, low cost device, and since the laser displacement system used is located outside the vacuum chamber, the measurement technique is free from radio frequency interference and thermal effects. It could be used to measure the thrust in the exhaust of other electric propulsion devices and the momentum flux of ion beams formed by expanding plasmas or fusion experiments.

  15. Effect of vacuum conditions and plasma concentration on the chemical composition and adhesion of vacuum-plasma coatings

    Science.gov (United States)

    Borisov, D. P.; Kuznetsov, V. M.; Slabodchikov, V. A.

    2015-11-01

    The paper reports on the chemical composition of titanium nitride (TiN) and silicon (Si) coatings deposited with a new technological vacuum plasma setup which comprises magnetron sputtering systems, arc evaporators, and an efficient plasma generator. It is shown that due to highly clean vacuum conditions and highly clean surface treatment in the gas discharge plasma, both the coating-substrate interface and the coatings as such are almost free from oxygen and carbon. It is found that the coating-substrate interface represents a layer of thickness ≥ 60 nm formed through vacuum plasma mixing of the coating and substrate materials. The TiN coatings obtained on the new equipment display a higher adhesion compared to brass coatings deposited by industrial technologies via intermediate titanium oxide layers. It is concluded that the designed vacuum plasma equipment allows efficient surface modification of materials and articles by vacuum plasma immersion processes.

  16. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Composition and dynamics of an erosion plasma produced by microsecond laser pulses

    Science.gov (United States)

    Anisimov, V. N.; Grishina, V. G.; Derkach, O. N.; Sebrant, A. Yu; Stepanova, M. A.

    1995-08-01

    The ion and energy compositions were determined and the dynamics was studied of an erosion plume formed by microsecond CO2 laser pulses incident on a graphite target. The ionic emission lines were used to find the electron density and temperature of the plasma on the target surface. The temperature of the plasma source did not change throughout the line emission time (4 μs). At the plasma recombination stage the lines of the C II, C III, and C IV ions were accompanied by bands of the C2 molecule near the target surface and also near the surface of an substrate when a plasma flow interacted with it. Ways were found for controlling the plume expansion anisotropy and for producing plasma flows with controlled parameters by selection of the conditions during formation of a quasisteady erosion plasma flow.

  17. Impact of anomalous dispersion on the interferometer measurements of plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, J; Johnson, W R; Iglesias, C A; Scofield, J H

    2004-12-16

    For many decades optical interferometers have been used to measure the electron density of plasmas. During the last ten years X-ray lasers in the wavelength range 14 to 47 nm have enabled researchers to use interferometers to probe even higher density plasmas. The data analysis assumes that the index of refraction is due only to the free electrons, which makes the index of refraction less than one and the electron density proportional to the number of fringe shifts. Recent experiments in Al plasmas observed plasmas with an index of refraction greater than one and made us question the validity of the usual formula for calculating the index of refraction. Recent calculations showed how the anomalous dispersion from the bound electrons can dominate the index of refraction in many types of plasma and make the index greater than one or enhance the index such that one would greatly overestimate the electron density of the plasma using interferometers. In this work we calculate the index of refraction of C, Al, Ti, and Pd plasmas for photon energies from 0 to 100 eV (12.4 nm) using a new average-atom code. The results show large variations from the free electron approximation under many different plasma conditions. We validate the average-atom code against the more detailed OPAL code for carbon and aluminum plasmas. During the next decade X-ray free electron lasers and other sources will be available to probe a wider variety of plasmas at higher densities and shorter wavelengths so understanding the index of refraction in plasmas will be even more essential.

  18. Evaluation of measurement of human TNF in plasma by ELISA.

    Science.gov (United States)

    Engelberts, I; Möller, A; Schoen, G J; van der Linden, C J; Buurman, W A

    1991-04-01

    The performance of a sandwich-ELISA for TNF measurement in plasma and serum was studied. The ELISA was first statistically analyzed. Interassay coefficient of variance and the intraassay coefficient of variance for the concentration range between 0.5 and 5 ng/ml was less than 10%. The sensitivity of the sandwich-ELISA for TNF in culture medium was 10 pg/ml. The ELISA was shown to be specific for biologically active TNF, since a good correlation between the ELISA and the WEHI bioassay was observed when partially inactive, denatured TNF was measured. The effect of various anticoagulation systems on the reliability of human TNF measurement has been evaluated. The oxalate/NaF and EDTA systems were both appropriate, as appeared from the observed blockade of the production of TNF in the tube, either in the cell-glycolysis-blocked or in the calcium-depleted situation, respectively. An eventual decrease in the recovery of rTNF after collection of blood was prevented in the oxalate/NaF tubes. Recovery of TNF in the ELISA was diminished in the presence of plasma or serum. Techniques to enhance the efficiency of the measurement of TNF in plasma by ELISA were compared. The data indicate that in the presence of 1.1 M NaCl, the TNF masking effect of normal plasma was largely abrogated. The presence and role of inhibiting plasma components in plasma of healthy and diseased individuals are discussed.

  19. Plasma composition in a sigmoidal anemone active region

    CERN Document Server

    Baker, D; Demoulin, P; van Driel-Gesztelyi, L; Green, L M; Steed, K; Carlyle, J

    2013-01-01

    Using spectra obtained by the EIS instrument onboard Hinode, we present a detailed spatially resolved abundance map of an active region (AR)-coronal hole (CH) complex that covers an area of 359 arcsec x 485 arcsec. The abundance map provides first ionization potential (FIP) bias levels in various coronal structures within the large EIS field of view. Overall, FIP bias in the small, relatively young AR is 2-3. This modest FIP bias is a consequence of the AR age, its weak heating, and its partial reconnection with the surrounding CH. Plasma with a coronal composition is concentrated at AR loop footpoints, close to where fractionation is believed to take place in the chromosphere. In the AR, we found a moderate positive correlation of FIP bias with nonthermal velocity and magnetic flux density, both of which are also strongest at the AR loop footpoints. Pathways of slightly enhanced FIP bias are traced along some of the loops connecting opposite polarities within the AR. We interpret the traces of enhanced FIP b...

  20. Opacity measurements in shock-generated argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.

    1993-07-01

    Dense plasmas having uniform and constant density and temperature are generated by passage of a planar shock wave through gas. The opacity of the plasma is accurately measured versus wavelength by recording the risetime of emitted light. This technique is applicable to a wide variety of species and plasma conditions. Initial experiments in argon have produced plasmas with 2 eV temperatures, 0.004--0.04 g/cm{sup 3} densities, and coupling parameters {Gamma} {approximately}0.3--0.7. Measurements in visible light are compared with calculations using the HOPE code. An interesting peak in the capacity at 400 nm is observed for the first time and is identified with the 4s-5p transition in excited neutral argon atoms.

  1. Effect of the applied power of atmospheric pressure plasma on the adhesion of composite resin to dental ceramic.

    Science.gov (United States)

    Han, Geum-Jun; Chung, Sung-No; Chun, Bae-Hyeock; Kim, Chang-Keun; Oh, Kyu-Hwan; Cho, Byeong-Hoon

    2012-08-01

    To evaluate the effect of applied power on dental ceramic bonding of composite resin using nonthermal atmospheric pressure plasma (APP). A pencil-type APP torch was used to modify the surface chemical composition and hydrophilicity of dental ceramic and to improve the adhesion of composite resin to the surface. The effect of the applied power on chemical changes of the plasma polymer on a ceramic surface and the adhesive strength between the composite resin and feldspathic porcelain were examined. Adhesion was evaluated by comparing shear bond strengths (SBS) using the iris method. The chemical composition of the plasma polymer deposited on the ceramic surface was evaluated using x-ray photoelectron spectroscopy (XPS). Hydrophilicity was evaluated by contact angle measurements. The fracture mode at the interface was also evaluated. The APP treatment was effective and the SBS of the experimental groups were significantly higher than those of the negative control group (p adhesion by producing carboxyl groups on the ceramic surface and as a result by improving surface hydrophilicity. The carboxyl group contents in the plasma polymer on the ceramic surface increased as the applied power increased.

  2. Laboratory measurements of the resistivity of warm dense plasmas

    Science.gov (United States)

    Booth, Nicola; Robinson, Alex; Hakel, Peter; Gregori, Ginaluca; Rajeev, Pattathil; Woolsey, Nigel

    2015-11-01

    In this talk we will present a method for studying material resistivity in warm dense plasmas in the laboratory in which we interrogate the microphysics of the low energy electron distributions associated with an anisotropic return current. Through experimental measurements of the polarization of the Ly- α doublet emission (2s1 / 2-2p1 / 2,3/2 transitions) of sulphur, we determine the resistivity of a sulphur-doped plastic target heated to warm dense conditions by an ultra-intense laser at relativistic intensities, I ~ 5 ×1020 Wcm-2. We describe a method of exploiting classical x-ray scattering to separately measure both the π- and σ- polarizations of Ly-α1 spectral emission in a single shot. These measurements make it possible to explore fundamental material properties such as resistivity in warm and hot dense plasmas through matching plasma physics modelling to atomic physics calculations of the experimentally measured large, positive, polarisation.

  3. Achievements of the plasma composition experiment on ISEE-1 during the IMS

    Science.gov (United States)

    Lennartsson, W.; Sharp, R. D.

    1984-01-01

    The ISEE-1 spacecraft measured energetic ion composition over a wide radial range in the near-equatorial magnetosphere, from close to the Earth to a distance of 23 RE. The Plasma Composition Experiment covers energies from 0 eV/e to 17 keV/e. Results for energetic O+ ions of terrestrial origin show that these ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions very similar to those of H+ ions. The O+ ions are the most numerous ions in the 0.1 to 17 keV/e energy range at L 5 and are often a substantial part of the ion population at larger distances as well, especially during geomagnetically disturbed conditions.

  4. Achievements of the plasma composition experiment on ISEE-1 during the IMS

    Science.gov (United States)

    Lennartsson, W.; Sharp, R. D.

    1984-09-01

    The ISEE-1 spacecraft measured energetic ion composition over a wide radial range in the near-equatorial magnetosphere, from close to the Earth to a distance of 23 RE. The Plasma Composition Experiment covers energies from 0 eV/e to 17 keV/e. Results for energetic O+ ions of terrestrial origin show that these ions are found in every region of the magnetosphere reached by the spacecraft and can have energy and pitch-angle distributions very similar to those of H+ ions. The O+ ions are the most numerous ions in the 0.1 to 17 keV/e energy range at L 5 and are often a substantial part of the ion population at larger distances as well, especially during geomagnetically disturbed conditions.

  5. Impact of plasma noise on a direct thrust measurement system

    Science.gov (United States)

    Pottinger, S. J.; Lamprou, D.; Knoll, A. K.; Lappas, V. J.

    2012-03-01

    In order to evaluate the accuracy and sensitivity of a pendulum-type thrust measurement system, a linear variable differential transformer (LVDT) and a laser optical displacement sensor have been used simultaneously to determine the displacement resulting from an applied thrust. The LVDT sensor uses an analog interface, whereas the laser sensor uses a digital interface to communicate the displacement readings to the data acquisition equipment. The data collected by both sensors show good agreement for static mass calibrations and validation with a cold gas thruster. However, the data obtained using the LVDT deviate significantly from that of the laser sensor when operating two varieties of plasma thrusters: a radio frequency (RF) driven plasma thruster, and a DC powered plasma thruster. Results establish that even with appropriate shielding and signal filtering the LVDT sensor is subject to plasma noise and radio frequency interactions which result in anomalous thrust readings. Experimental data show that the thrust determined using the LVDT system in a direct current plasma environment and a RF discharge is approximately a factor of three higher than the thrust values obtained using a laser sensor system for the operating conditions investigated. These findings are of significance to the electric propulsion community as LVDT sensors are often utilized in thrust measurement systems and accurate thrust measurement and the reproducibility of thrust data is key to analyzing thruster performance. Methods are proposed to evaluate system susceptibility to plasma noise and an effective filtering scheme presented for DC discharges.

  6. Tokamak Plasmas : Internal magnetic field measurement in tokamak plasmas using a Zeeman polarimeter

    Indian Academy of Sciences (India)

    M Jagadeeshwari; J Govindarajan

    2000-11-01

    In a tokamak plasma, the poloidal magnetic field profile closely depends on the current density profile. We can deduce the internal magnetic field from the analysis of circular polarization of the spectral lines emitted by the plasma. The theory of the measurement and a detailed design of the Zeeman polarimeter constructed to measure the poloidal field profile in the ADITYA tokamak are presented. The Fabry-Perot which we have employed in our design, with photodiode arrays followed by lock-in detection of the polarization signal, allows the measurement of the fractional circular polarization. In this system He-II line with wavelength 4686 Å is adopted as the monitoring spectral line. The line emission used in the present measurement is not well localized in the plasma, necessiating the use of a spatial inversion procedure to obtain the local values of the field.

  7. Automatic measurements of plasma parameters in the PUPR mirror and cusp plasma machine

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, S; Colmenares, F; Gonzalez-Lizardo, A; Leal-Quiros, E [Plasma Engineering Laboratory, Polytechnic University of Puerto Rico, San Juan, PR 00918 (Puerto Rico)

    2008-10-15

    This paper presents an ongoing effort to develop an automatic measurement system for plasma diagnostics at the Plasma Engineering Laboratory of the Polytechnic University of Puerto Rico (PUPR), along with an example of its operation. The system is intended to be used with electrostatic probes such as single and double Langmuir probes, emissive probes, ion and electron energy analyzers, etc. The automatic measurement system includes automatic positioning of the probes inside the plasma chamber, automatic voltage sweep of the probes for each position, and automatic analysis of the probe I-V characteristic. The results of measurements obtained by using this automatic measurement system during a particular experiment are shown and compared with a traditional method with satisfactory results.

  8. Distance-dependent plasma composition and ion energy in high power impulse magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ehiasarian, Arutiun P; Andersson, Joakim; Anders, Andr& #233

    2010-04-18

    The plasma composition of high power impulse magnetron sputtering (HIPIMS) has been studied for titanium and chromium targets using a combined energy analyser and quadrupole mass spectrometer. Measurements were done at distances from 50 to 300 mm from the sputtering target. Ti and Cr are similar in atomic mass but have significantly different sputter yields, which gives interesting clues on the effect of the target on plasma generation and transport of atoms. The Ti and Cr HIPIMS plasmas operated at a peak target current density of ~;;0.5 A cm-2. The measurements of the argon and metal ion content as well as the ion energy distribution functions showed that (1) singly and doubly charged ions were found for argon as well as for the target metal, (2) the majority of ions were singly charged argon for both metals at all distances investigated, (3) the Cr ion density was maintained to distances further from the target than Ti. Gas rarefaction was identified as a main factor promoting transport of metal ions, with the stronger effect observed for Cr, the material with higher sputter yield. Cr ions were found to displace a significant portion of the gas ions, whereas this was less evident in the Ti case. The observations indicate that the presence of metal vapour promotes charge exchange and reduces the electron temperature and thereby practically prevents the production of Ar2+ ions near the target. The content of higher charge states of metal ions depends on the probability of charge exchange with argon.

  9. Fabrication, characterization, and mechanical properties of spark plasma sintered Al–BN nanoparticle composites

    Energy Technology Data Exchange (ETDEWEB)

    Firestein, Konstantin L., E-mail: kosty@firestein.ru [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Steinman, Alexander E.; Golovin, Igor S. [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Cifre, Joan [Universitat de les Illes Balears, Ctra. de Valldemossa, km. 7.5, E-07122 Palma de Mallorca (Spain); Obraztsova, Ekaterina A.; Matveev, Andrei T.; Kovalskii, Andrey M. [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Lebedev, Oleg I. [CRISMAT, UMR 6508, CNRS-ENSICAEN, 6Bd Marechal Juin, 14050 Caen (France); Shtansky, Dmitry V., E-mail: shtansky@shs.misis.ru [National University of Science and Technology “MISIS”, Leninsky prospect 4, Moscow 119049 (Russian Federation); Golberg, Dmitri, E-mail: golberg.dmitri@nims.go.jp [World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) National Institute for Materials Science (NIMS), Namiki 1, Tsukuba, Ibaraki 3050044 (Japan)

    2015-08-26

    Fabrication of high strength yet light and low cost composite materials with good mechanical properties at room and elevated temperatures is a challenge that metallurgy and materials science communities are facing for many years, and no “dream material” has been developed so far. The primary goal of this study was to fabricate, characterize, and to carry out tensile tests on Al-based composite materials strengthened with commercially-available BN nanoparticles (BNNPs). The composites were fabricated by spark plasma sintering (SPS) technique. The structures of powder mixtures and composite materials, as well as their fracture surfaces, were studied by scanning and transmission electron microscopy. The influence of BNNPs content (0.5, 1.5, 3, 4.5, 6, and 7.5 wt%) and holding times (5, 60, and 300 min) at 600 °C during SPS on the tensile strength was investigated. A maximum increase in strength was observed for Al-based composites with 4.5 wt% of BNNPs. The sample demonstrated a 50% increase in tensile strength compared with pristine Al. Although the tensile tests performed at 300 °C revealed that the tensile strength became 20% lower than the strength at room temperature, it was, however, still 75% higher compared with that of the pure Al at 300 °C. In addition, at 300 °C the Al–BNNPs composites demonstrated a much higher value of yield stress, about 115 MPa, which is 190% higher than that of pure Al at the same temperature. The damping properties of Al–BNNPs composites were evaluated by temperature dependent internal friction (TDIF) measurements. The obtained results are discussed based on structural analysis and the TDIF data.

  10. Simultaneous Multi-angle Measurements of Plasma Turbulence at HAARP

    Science.gov (United States)

    Watanabe, Naomi; Golkowski, Mark; Sheerin, James; University of Colorado Denver Team

    2013-10-01

    We report the results from a recent series of experiments employing the HAARP HF transmitter to generate and study strong Langmuir turbulence (SLT) in the interaction region of overdense ionospheric plasma. Diagnostics included the Modular UHF Ionospheric Radar (MUIR) located at HAARP, the Super DARN-Kodiak HF radar, and HF receivers to record stimulated electromagnetic emissions (SEE). Short pulse, low duty cycle experiments demonstrate control and suppression of artificial field-aligned irregularities (AFAI). This allows the isolation of ponderomotive plasma turbulence effects. For the first time, plasma line spectra measured simultaneously in different spots of the interaction region displayed marked but contemporaneous differences dependent on the aspect angle of the HF pump beam and the pointing angle of the MUIR diagnostic radar. Outshifted Plasma Line (OPL) spectra, rarely observed in past experiments, occurred with sufficient regularity for experimentation. Experimental results are compared to previous high latitude experiments and predictions from recent modeling efforts.

  11. Climatology of high-β plasma measurements in Earth's inner magnetosphere

    Science.gov (United States)

    Cohen, Ross; Gerrard, Andrew J.; Lanzerotti, Louis J.; Soto-Chavez, A. R.; Kim, Hyomin; Manweiler, Jerry W.

    2017-01-01

    Since their launch in August 2012, the Radiation Belt Storm Probe Ion Composition Experiment (RBSPICE) instruments on the NASA Van Allen Probes spacecraft have been making continuous high-resolution measurements of Earth's ring current plasma environment. After a full traversal through all magnetic local times, a climatology (i.e., a survey of observations) of high-beta (β) plasma events (defined here as β > 1) as measured by the RBSPICE instrument in the ˜45 keV to ˜600 keV proton energy range in the inner magnetosphere (L hours. While most of these events have a β less than 2, there are a number of observations reaching β greater than 4. Other observations of particular note are high-β events during relatively minor geomagnetic storms and examples of very long duration high-β plasmas. We show that high-β plasmas are a relatively common occurrence in the inner magnetosphere during both quiet and active times. As such, the waves generated by these plasmas may have an underappreciated role in the inner magnetosphere, and thus the study of these plasmas and their instabilities may be more important than has been currently addressed.

  12. OPACITY MEASUREMENT AND THEORETICAL INVESTIGATION OF HOT SILICON PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Gang; Yang, Jiamin; Zhang, Jiyan; Hu, Zhimin; Zhao, Yang; Qing, Bo; Yang, Guohong; Wei, Minxi; Yi, Rongqing; Song, Tianming; Li, Hang; Yuan, Zheng; Lv, Min [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Meng, Xujun; Xu, Yan; Wu, Zeqing; Yan, Jun, E-mail: zhangjiyanzjy@sina.com, E-mail: zhimin.hu@yahoo.com [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2016-01-01

    We report on opacity measurements of a silicon (Si) plasma at a temperature of (72 ± 5) eV and a density of (6.0 ± 1.2) mg cm{sup −3} in the photon energy range of 1790–1880 eV. A 23 μg cm{sup −2} Si foil tamped by 50 μg cm{sup −2} CH layers on each side was heated to a hot-dense plasma state by X-ray radiation emitted from a D-shaped gold cavity that was irradiated by intense lasers. Absorption lines of 1s − 2p transitions of Si xiii to Si ix ions have been measured using point-projection spectroscopy. The transmission spectrum of the silicon plasma was determined by comparing the light passing through the plasma to the light from the same shot passing by the plasma. The density of the Si plasma was determined experimentally by side-on radiography and the temperature was estimated from the radiation flux data. Radiative hydrodynamic simulations were performed to obtain the temporal evolutions of the density and temperature of the Si plasma. The experimentally obtained transmission spectra of the Si sample plasma have been reproduced using a detailed term account model with the local thermodynamic equilibrium approximation. The energy levels, oscillator strengths and photoionization cross-sections used in the calculation were generated by the flexible atomic code. The experimental transmission spectrum was compared with the theoretical calculation and good agreement was found. The present experimental spectrum and theoretical calculation were also compared with the new opacities available in the Los Alamos OPLIB database.

  13. Reflectometry techniques for density profile measurements on fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Laviron, C. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Donne, A.J.H. [Associatie Euratom-FOM, Nieuwegein (Netherlands). FOM-Instituut voor Plasmafysica; Manso, M.E. [Instituto Superior Tecnico, Lisbon (Portugal). Lab. de Quimica Organica; Sanchez, J. [EURATOM-CIEMAT for Fusion Association, Madrid (Spain)

    1996-03-01

    Reflectometry applied to the measurement of density profiles on fusion plasmas has been subject to many recent developments. After a brief reminder of the principles of reflectometry, the theoretical accuracy of reflectometry measurements is discussed. The main difficulties limiting the performance, namely the plasma fluctuations and the quality of the transmission lines, are analysed. The different techniques used for reflectometry are then presented. The present status and achievements of actual implementations of these techniques are shown, with an analysis of their respective limitations and merits, as well as foreseen developments. (author). 70 refs.

  14. Composition Measurements from ISEE-3: Fluorine through Calcium

    OpenAIRE

    Leske, R. A.; Wiedenbeck, M. E.

    1993-01-01

    Spacecraft measurements are reported of the elemental composition of galactic cosmic rays with 9 ≤ Z ≤ 5 ~20 at energies ~220 MeV /nucleon. In addition, for the elements with 16 ≤ Z ≤ 20 isotopic composition results are reported. The measured composition is found to be in generally good agreement with that expected from a propagated solar-like source.

  15. Measurement of Atmospheric Composition from Geostationary Platforms

    Science.gov (United States)

    Bhartia, P. K.; Kawa, S. R.; Janz, S.; Herman, J. R.; Gleason, J. F.

    2008-01-01

    Satellite instruments flown since 1970 have had great success in elucidating the processes that control stratospheric ozone. In contrast, space-based data for tropospheric constituents that affect air quality and climate have only recently become available. While these datasets highlight the rapidly advancing capabilities of spacebased tropospheric sensors, they are also pointing to the limitations of sun-synchronous, low-earth orbiting (SSO/LEO) satellite platforms for making such measurements. In our talk we will highlight the science requirements for new missions and the technological and algorithmic approaches that we are developing to meet these requirements. From these studies a clear need for advanced atmospheric composition sensors has emerged that can be put on geostationary (GEO) platforms to provide 5 km horizontal resolution with 15-60 minutes repeat cycle. Such measurements have been high priority in the recently released Decadal Survey report by the US National Research Council. The need for GEO is driven not only by the science requirements to track rapidly changing pollution events but also by the need to provide altitude-resolved information about tropospheric constituents. Currently, with the exception of aerosols, it is not possible to derive profile information about lower tropospheric constituents from satellite measurements. New algorithmic approaches are being developed to obtain this information by combining UV and IR data, by monitoring the spatial and temporal structures of the constituents, and by using low-level clouds to separate boundary layer constituents from free troposphere. All these approaches require better spatial and temporal resolution than that provided by LEO sensors.

  16. Effect of Composition on Mechanical Properties of Mullite-WC Nano Composites Prepared by Spark Plasma Sintering

    Directory of Open Access Journals (Sweden)

    H. Rajaei

    2016-12-01

    Full Text Available Mullite-WC composites were prepared from Mullite and WC powders by spark plasma sintering at 1400 °C for a holding time of 180 s under 30 MPa. Microstructure, strength, and hardness of the mullite-WC composites were studied. The mullite-WC composite containing 5-20 wt% WC reached over 94 % theoretical density. The strength and Vickers hardness of mullite-(10 wt% WC sintered composite reached maximum values of 298 MPa, and 1589 HV, respectively demonstrating that the introduction of WC significantly enhances the mechanical properties of the mullite matrix.

  17. Harmonic generation measurements in unidirectional graphite/epoxy composites

    Science.gov (United States)

    Wu, Meng-Chou; Prosser, William H.

    1991-01-01

    A new quantitative technique using piezoelectric transducers bonded directly to specimens has been developed for measuring the nonlinearity of composites. The use of the technique to calculate nine third-order elastic coefficients for a transversely isotropic composite is reported.

  18. Formation of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films in Vacuum Using Coaxial Arc Plasma Gun

    Science.gov (United States)

    Hanada, Kenji; Yoshida, Tomohiro; Nakagawa, You; Yoshitake, Tsuyoshi

    2010-12-01

    Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite films were grown in vacuum using a coaxial arc plasma gun. From the X-ray diffraction measurement, the UNCD crystallite size was estimated to be 1.6 nm. This size is dramatically reduced from that (2.3 nm) of UNCD/hydrogenated amorphous carbon (a-C:H) composite films grown in a hydrogen atmosphere. The sp3/(sp3 + sp2) value, which was estimated from the X-ray photoemission spectrum, was also reduced to be 41%. A reason for it might be the reduction in the UNCD crystallite size. From the near-edge X-ray absorption fine-structure (NEXAFS) spectrum, it was found that the π*C=C and π*C≡C bonds are preferentially formed instead of the σ*C-H bonds in the UNCD/a-C:H films. Since the extremely small UNCD crystallites (1.6 nm) correspond to the nuclei of diamond, we consider that UNCD crystallite formation should be due predominantly to nucleation. The supersaturated condition required for nucleation is expected to be realized in the deposition using the coaxial arc plasma gun.

  19. Plasma-enhanced growth, composition, and refractive index of silicon oxy-nitride films

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    1995-01-01

    Secondary ion mass spectrometry and refractive index measurements have been carried out on silicon oxy-nitride produced by plasma-enhanced chemical vapor deposition (PECVD). Nitrous oxide and ammonia were added to a constant flow of 2% silane in nitrogen, to produce oxy-nitride films with atomic...... nitrogen concentrations between 2 and 10 at. %. A simple atomic valence model is found to describe both the measured atomic concentrations and published material compositions for silicon oxy-nitride produced by PECVD. A relation between the Si–N bond concentration and the refractive index is found....... This relation suggest that the refractive index of oxy-nitride with a low nitrogen concentration is determined by the material density. It is suggested that the relative oxygen concentration in the gas flow is the major deposition characterization parameter, and that water vapor is the predominant reaction by...

  20. Measuring the antioxidant capacity of blood plasma using potentiometry.

    Science.gov (United States)

    Tessutti, L S; Macedo, D V; Kubota, L T; Alves, A A

    2013-10-15

    The use of potentiometry to measure plasma antioxidant capacity to contribute to oxidative stress evaluation is presented. In this assay, plasma (n=60) diluted (0.3 to 1 ml) in phosphate buffer, pH 7.4, NaCl 9%, was submitted to potentiometry. A platinum wire was the working electrode and saturated calomel the reference. The results are presented as the difference between sample and buffer potential (ΔE). ΔE presented a good inverse correlation with added increasing concentrations of ascorbate (2.5-75 μmol/L; R=-0.99), urate (9.0-150 μmol/L; R=-0.99), and bilirubin (0.78-13 μmol/L; R=-0.99). Increase in the antioxidant capacity decreased ΔE. Depletion of the antioxidant capacity by tert-butylhydroperoxide (6.5-50 μmol/L) presented a direct correlation (0.97) with ΔE. Furthermore, ΔE presented an inverse correlation (R=-0.99) with increased antioxidant capacity of plasma (FRAP) induced by the addition of ascorbate (2.5-75 μmol/L). The response of the potentiometric method proved be adequate for measuring the plasma antioxidant depletion induced by acute exhaustive exercise in rats (control, n=15; exercised, n=15). This exercise decreased the concentration of urate (ppotentiometry for evaluating the antioxidant capacity of blood plasma samples.

  1. Two spacecraft measurements of the Martian plasma environment

    Science.gov (United States)

    Brain, David; Luhmann, Janet G.; Barabash, Stas; Fedorov, A.; Winningham, D. L.; Acuna, Mario; Frahm, Rudy

    For a period of nearly three years from early 2004 through late 2006, two spacecraft made complementary in situ measurements of the Martian plasma environment. The Mars Global Surveyor magnetometer and electron reflectometer (MGS MAG/ER) measured magnetic fields and suprathermal electrons from an orbit fixed in local time and altitude. The Mars Express Analyzer of Space Plasma and Energetic Atoms (MEX ASPERA-3) measured and still measures ions and suprathermal electrons from a precessing elliptical orbit. MGS lacked an ion instrument, and MEX lacks a magnetometer. Study of the two sets of measurements together provides an opportunity to better understand the complete Martian plasma environment spatially and temporally. We will discuss several advantageous configurations of MEX and MGS, and present examples of each. 'Close conjunctions' are defined as periods when the spacecraft passed very close to each other, within an ion gyroradius or inertial length, allowing examination of more complete particle and field measurements in a given region. 'Delay conjunctions' are defined as instances when the two spacecraft passed through the same region of space separated by a time delay, allowing examination of the evolution of electron distributions in a given region. 'Flux tube conjunctions' are defined as instances when it was likely that the two spacecraft occupied the same flux tube some distance apart, allowing study of the spatial evolution of plasma as it moves along a flux tube. We will also present examples of other fortuitous configurations of MEX and MGS, such as times when they were on opposite sides of a given plasma boundary.

  2. Application of coherent lidar to ion measurements in plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, D.P.; Richards, R.K.; Bennett, C.A.; Simpson, M.L.

    1997-03-01

    A coherent lidar system has been constructed for the measurement of alpha particles in a burning plasma. The lidar system consists of a pulsed CO{sub 2} laser transmitter and a heterodyne receiver. The receiver local oscillator is a cw, sequence-band CO{sub 2} laser operating with a 63.23 GHz offset from the transmitter.

  3. Measurement of plasma momentum exerted on target by a small helicon plasma thruster and comparison with direct thrust measurement.

    Science.gov (United States)

    Takahashi, Kazunori; Komuro, Atsushi; Ando, Akira

    2015-02-01

    Momentum, i.e., force, exerted from a small helicon plasma thruster to a target plate is measured simultaneously with a direct thrust measurement using a thrust balance. The calibration coefficient relating a target displacement to a steady-state force is obtained by supplying a dc to a calibration coil mounted on the target, where a force acting to a small permanent magnet located near the coil is directly measured by using a load cell. As the force exerted by the plasma flow to the target plate is in good agreement with the directly measured thrust, the validity of the target technique is demonstrated under the present operating conditions, where the thruster is operated in steady-state. Furthermore, a calibration coefficient relating a swing amplitude of the target to an impulse bit is also obtained by pulsing the calibration coil current. The force exerted by the pulsed plasma, which is estimated from the measured impulse bit and the pulse width, is also in good agreement with that obtained for the steady-state operation; hence, the thrust assessment of the helicon plasma thruster by the target is validated for both the steady-state and pulsed operations.

  4. Diffusion in plasma: the Hall effect, compositional waves, and chemical spots

    CERN Document Server

    Urpin, Vadim

    2016-01-01

    We consider diffusion caused by a combined influence of the electric current and the Hall effect, and argue that such diffusion can form inhomogeneities of the chemical composition in plasma. The considered mechanism can be responsible for a formation of element spots in laboratory and astrophysical plasmas. This current-driven diffusion can be accompanied by propagation of a particular type waves in which the impurity number density oscillate alone. These compositional waves exist if the magnetic pressure in plasma is much greater than the gas pressure,

  5. Measurement of plasma hydrogen sulfide in vivo and in vitro

    OpenAIRE

    Shen, Xinggui; Pattillo, Christopher B.; Pardue, Sibile; Bir, Shyamal C.; Wang, Rui; Kevil, Christopher G.

    2011-01-01

    The gasotransmitter hydrogen sulfide is known to regulate multiple cellular functions during normal and pathophysiological states. However, a paucity of concise information exists regarding quantitative amounts of hydrogen sulfide involved in physiological and pathological responses. This is primarily due to disagreement among various methods employed to measure free hydrogen sulfide. In this article, we describe a very sensitive method of measuring the presence of H2S in plasma down to nanom...

  6. Temperature measurements in thermal plasmas; Mesures de temperatures dans les plasmas thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Fauchais, P.; Coudert, J.F. [Limoges Univ., 87 (France)

    1996-05-01

    Thermal plasmas are characterized by a high pressure (10{sup 4} to 10{sup 6} Pa) and a high density of particles. Plasmas considered in this paper are produced by electric discharges, arcs, injection torches with cold or hot cathodes, water vortex torches, RF devices and are characterized by temperatures ranging from 6000 to 40000 K and ionization energies ranging from 13.5 and 16 eV (in argon, argon-hydrogen, nitrogen, nitrogen-hydrogen, argon-helium, air, oxygen, CO{sub 2} or water). Temperature measurements in thermal plasmas are difficult due to their extreme luminosity, flow rate and thermal flux, and to their temperature and flow rate gradients. The most common measurement methods are the emission spectroscopy, the laser scattering (Rayleigh, Thomson and coherent anti-Stokes Raman scattering) and the enthalpy probes. The first two methods are non-intrusive, while the last method is intrusive. This paper gives first some general remarks about the principles of each technique and focusses on the problem of fluctuations due to the plasma jet instabilities. Then, it describes briefly each technique and gives some examples of results. Finally, it compares the spectroscopic measurements with other measurements. (J.S.) 80 refs.

  7. Functionalization of Natural Cork Composite with Microcapsules after Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Fernando Ribeiro Oliveira

    2014-01-01

    Full Text Available This research aims to study the chemical and physical modifications of natural cork agglomerate after plasma treatment using dielectric barrier discharge (DBD. Different experimental techniques were used to evaluate the surface alterations of the pretreated samples with DBD plasma, as well as the adsorption and adhesion of microcapsules in the substrate, namely, static and dynamic contact angle, surface energy, energy dispersive spectroscopy (EDS, Fourier transform infrared spectroscopy (FTIR, differential scanning calorimetry (DSC, and scanning electron microscopy (SEM. Plasma discharge greatly increases the wettability and surface energy of the samples. Chemical and physical analyses of the cork agglomerate confirmed considerable surface modification. All these surface changes of the cork after plasma treatment led to a remarkable increase in microcapsule adsorption and adhesion when compared with the untreated cork sample.

  8. Measurement of the effective plasma ion mass in large tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Lister, J.B.; Villard, L.; Ridder, G. de [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)

    1997-06-01

    There is not yet a straightforward method for the measurement of the D-T ratio in the centre of a tokamak plasma. One of the simpler measurements put forward in the past is the interpretation of the MHD spectrum in the frequency range of the Global Alfven Eigenmodes (GAE). However, the frequencies of these modes do not only depend on the plasma mass, but are also quite strongly dependent on the details of the current and density profiles, creating a problem of deconvolution of the estimate of the plasma mass from an implicit relationship between several measurable plasma parameters and the detected eigenmode frequencies. This method has been revised to assess its likely precision for the JET tokamak. The low n GAE modes are sometimes too close to the continuum edge to be detectable and the interpretation of the GAE spectrum is rendered less direct than had been hoped. We present a statistical study on the precision with which the D-T ratio could be estimated from the GAE spectrum on JET. (author) 4 figs., 8 refs.

  9. Cold-atmospheric pressure plasma polymerization of acetylene on wood flour for improved wood plastics composites

    Science.gov (United States)

    Lekobou, William; Pedrow, Patrick; Englund, Karl; Laborie, Marie-Pierre

    2009-10-01

    Plastic composites have become a large class of construction material for exterior applications. One of the main disadvantages of wood plastic composites resides in the weak adhesion between the polar and hydrophilic surface of wood and the non-polar and hydrophobic polyolefin matrix, hindering the dispersion of the flour in the polymer matrix. To improve interfacial compatibility wood flour can be pretreated with environmentally friendly methods such as cold-atmospheric pressure plasma. The objective of this work is therefore to evaluate the potential of plasma polymerization of acetylene on wood flour to improve the compatibility with polyolefins. This presentation will describe the reactor design used to modify wood flour using acetylene plasma polymerization. The optimum conditions for plasma polymerization on wood particles will also be presented. Finally preliminary results on the wood flour surface properties and use in wood plastic composites will be discussed.

  10. A microwave interferometer for small and tenuous plasma density measurements.

    Science.gov (United States)

    Tudisco, O; Lucca Fabris, A; Falcetta, C; Accatino, L; De Angelis, R; Manente, M; Ferri, F; Florean, M; Neri, C; Mazzotta, C; Pavarin, D; Pollastrone, F; Rocchi, G; Selmo, A; Tasinato, L; Trezzolani, F; Tuccillo, A A

    2013-03-01

    The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10(16) m(-3) and 10(19) m(-3)) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small (λ = 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02° has been used, corresponding to a density of 0.5 × 10(16) m(-3).

  11. A microwave interferometer for small and tenuous plasma density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tudisco, O.; Falcetta, C.; De Angelis, R.; Florean, M.; Neri, C.; Mazzotta, C.; Pollastrone, F.; Rocchi, G.; Tuccillo, A. A. [ENEA CR Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Lucca Fabris, A.; Manente, M.; Ferri, F.; Tasinato, L.; Trezzolani, F. [CISAS ' G.Colombo,' Universita degli studi di Padova, Via Venezia 15, 35131 Padova (Italy); Accatino, L. [ACC Antenna and MW tech, Via Trieste 16/B, 10098 Rivoli (Italy); Pavarin, D. [Dip. di Ingegneria Industriale (DII), Universita degli Studi di Padova, Via Venezia 1, 35131 Padova (Italy); Selmo, A. [RESIA, Studio Progettazione e Realizzazione di Apparati Elettronici, via Roma 17, 37041 Albaredo d' Adige (Italy)

    2013-03-15

    The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10{sup 16} m{sup -3} and 10{sup 19} m{sup -3}) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small ({lambda}= 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02 Degree-Sign has been used, corresponding to a density of 0.5 Multiplication-Sign 10{sup 16} m{sup -3}.

  12. Plasma resistivity measurements in the Wisconsin levitated octupole

    Energy Technology Data Exchange (ETDEWEB)

    Brouchous, D. A.

    1980-11-01

    Resistivity measurements parallel to the magnetic field were made on gun injected plasmas ranging in density from 10/sup 9/cm/sup -3/ to 10/sup 1/parallelcm/sup -3/ in the Wisconsin levitated octupole with toroidal and poloidal magnetic fields. The 10/sup 9/cm/sup -3/ plasma was collisionless with lambda/sub mfp/ > 100 mirror lengths, had T/sub e/ = 10 eV, T/sub i/ = 30 eV and was found to have anomalous resistivity scaling like eta = ..sqrt..T/sub e//n/sub e/ when E/sub parallel/ > E/su c/ is the Dreicer critical field. The 10/sup 12/cm/sup -3/ plasma was collisional with lambda/sub mfp/ < mirror length, had T/sub e/ = T/sub i/ approx. = .2 eV and was found to have Spitzer resistivity when E/sub parallel/ < E/sub c/.

  13. An integrated time-of-flight versus residual energy subsystem for a compact dual ion composition experiment for space plasmas.

    Science.gov (United States)

    Desai, M I; Ogasawara, K; Ebert, R W; McComas, D J; Allegrini, F; Weidner, S E; Alexander, N; Livi, S A

    2015-05-01

    We have developed a novel concept for a Compact Dual Ion Composition Experiment (CoDICE) that simultaneously provides high quality plasma and energetic ion composition measurements over 6 decades in ion energy in a wide variety of space plasma environments. CoDICE measures the two critical ion populations in space plasmas: (1) mass and ionic charge state composition and 3D velocity and angular distributions of ∼10 eV/q-40 keV/q plasma ions—CoDICE-Lo and (2) mass composition, energy spectra, and angular distributions of ∼30 keV-10 MeV energetic ions—CoDICE-Hi. CoDICE uses a common, integrated Time-of-Flight (TOF) versus residual energy (E) subsystem for measuring the two distinct ion populations. This paper describes the CoDICE design concept, and presents results of the laboratory tests of the TOF portion of the TOF vs. E subsystem, focusing specifically on (1) investigation of spill-over and contamination rates on the start and stop microchannel plate (MCP) anodes vs. secondary electron steering and focusing voltages, scanned around their corresponding model-optimized values, (2) TOF measurements and resolution and angular resolution, and (3) cross-contamination of the start and stop MCPs' singles rates from CoDICE-Lo and -Hi, and (4) energy resolution of avalanche photodiodes near the lower end of the CoDICE-Lo energy range. We also discuss physical effects that could impact the performance of the TOF vs. E subsystem in a flight instrument. Finally, we discuss advantages of the CoDICE design concept by comparing with capabilities and resources of existing flight instruments.

  14. An integrated time-of-flight versus residual energy subsystem for a compact dual ion composition experiment for space plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Desai, M. I.; McComas, D. J.; Allegrini, F.; Livi, S. A. [Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238-5166 (United States); Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0697 (United States); Ogasawara, K.; Ebert, R. W.; Weidner, S. E.; Alexander, N. [Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas 78238-5166 (United States)

    2015-05-15

    We have developed a novel concept for a Compact Dual Ion Composition Experiment (CoDICE) that simultaneously provides high quality plasma and energetic ion composition measurements over 6 decades in ion energy in a wide variety of space plasma environments. CoDICE measures the two critical ion populations in space plasmas: (1) mass and ionic charge state composition and 3D velocity and angular distributions of ∼10 eV/q–40 keV/q plasma ions—CoDICE-Lo and (2) mass composition, energy spectra, and angular distributions of ∼30 keV–10 MeV energetic ions—CoDICE-Hi. CoDICE uses a common, integrated Time-of-Flight (TOF) versus residual energy (E) subsystem for measuring the two distinct ion populations. This paper describes the CoDICE design concept, and presents results of the laboratory tests of the TOF portion of the TOF vs. E subsystem, focusing specifically on (1) investigation of spill-over and contamination rates on the start and stop microchannel plate (MCP) anodes vs. secondary electron steering and focusing voltages, scanned around their corresponding model-optimized values, (2) TOF measurements and resolution and angular resolution, and (3) cross-contamination of the start and stop MCPs’ singles rates from CoDICE-Lo and -Hi, and (4) energy resolution of avalanche photodiodes near the lower end of the CoDICE-Lo energy range. We also discuss physical effects that could impact the performance of the TOF vs. E subsystem in a flight instrument. Finally, we discuss advantages of the CoDICE design concept by comparing with capabilities and resources of existing flight instruments.

  15. Associations between plasma branched-chain amino acids, β-aminoisobutyric acid and body composition.

    Science.gov (United States)

    Rietman, Annemarie; Stanley, Takara L; Clish, Clary; Mootha, Vamsi; Mensink, Marco; Grinspoon, Steven K; Makimura, Hideo

    2016-01-01

    Plasma branched-chain amino acids (BCAA) are elevated in obesity and associated with increased cardiometabolic risk. β-Aminoisobutyric acid (B-AIBA), a recently identified small molecule metabolite, is associated with decreased cardiometabolic risk. Therefore, we investigated the association of BCAA and B-AIBA with each other and with detailed body composition parameters, including abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). A cross-sectional study was carried out with lean (n 15) and obese (n 33) men and women. Detailed metabolic evaluations, including measures of body composition, insulin sensitivity and plasma metabolomics were completed. Plasma BCAA were higher (1·6 (se 0·08) (×10(7)) v. 1·3 (se 0·06) (×10(7)) arbitrary units; P = 0·005) in obese v. lean subjects. BCAA were positively associated with VAT (R 0·49; P = 0·0006) and trended to an association with SAT (R 0·29; P = 0·052). The association between BCAA and VAT, but not SAT, remained significant after controlling for age, sex and race on multivariate modelling (P BCAA were also associated with parameters of insulin sensitivity (Matsuda index: R -0·50, P = 0·0004; glucose AUC: R 0·53, P BCAA were not associated with B-AIBA (R -0·04; P = 0·79). B-AIBA was negatively associated with SAT (R -0·37; P = 0·01) but only trended to an association with VAT (R 0·27; P = 0·07). However, neither relationship remained significant after multivariate modelling (P > 0·05). Plasma B-AIBA was associated with parameters of insulin sensitivity (Matsuda index R 0·36, P = 0·01; glucose AUC: R -0·30, P = 0·04). Plasma BCAA levels were positively correlated with VAT and markers of insulin resistance. The results suggest a possible complex role of adipose tissue in BCAA homeostasis and insulin resistance.

  16. Measurements of the Motion of Plasma Filaments in a Plasma Ball

    Energy Technology Data Exchange (ETDEWEB)

    Campanell, M.; Laird, J.; Provost, T.; Vasquez, S.; Zweben, S. J.

    2010-01-26

    Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ~106 cm/sec at the driving frequency of ~26 kHz, and drift upward through the ball at ~1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.

  17. Study of atmospheric pressure weakly ionized plasma as surface compatibilization technique for improved plastic composites loaded with cellulose based fillers

    Science.gov (United States)

    Lekobou, William Pimakouon

    Atmospheric pressure plasmas have gained considerable interest from researchers recently for their unique prospective of engineering surfaces with plasma without the need of vacuum systems. They offer the advantage of low energy consumption, minimal capital cost and their simplicity as compared to conventional low pressure plasmas make them easy to upscale from laboratory to industry size. The present dissertation summarizes results of our attempt at applying atmospheric pressure weakly ionized plasma (APWIP) to the engineering of plastic composites filled with cellulose based substrates. An APWIP reactor was designed and built based on a multipoint-to-grounded ring and screen configurations. The carrier gas was argon and acetylene serves as the precursor molecule. The APWIP reactors showed capability of depositing plasma polymerized coating rich in carbon on substrates positioned within the electrode gap as well as downstream of the plasma discharge into the afterglow region. Our findings show that films grow by forming islands which for prolonged deposition time grow into thin films showing nodules, aggregates of nodules and microspheres. They also show chemical structure similar to films deposited from hydrocarbons with other conventional plasma techniques. The plasma polymerized deposits were used on substrates to modify their surface properties. Results show the surface of wood veneer and wood flour can be finely tuned from hydrophilic to hydrophobic. It was achieved by altering the topography of the surfaces along with their chemical composition. The wettability of wood veneer was investigated with contact angle measurements on capacitive drops and the capillary effect was utilized to assess surface properties of wood flour exposed to the discharges.

  18. Measurement of cosmic ray chemical composition at Mt. Chacaltaya

    Energy Technology Data Exchange (ETDEWEB)

    Ogio, S.; Kakimoto, F.; Harada, D.; Tokunou, H.; Burgoa, O.; Tsunesada, Y. [Institute of Technology, Dept. of Physics, Tokuo (Japan); Shirasaki, Y. [National Space Development Agency of Japan, Tsukuba (Japan); Gotoh, E.; Nakatani, H.; Shimoda, S.; Nishi, K.; Tajima, N.; Yamada, Y. [The Institute of Physical and Chemical Research, Wako, Saitama (Japan); Kaneko, T. [Okayama University, Dept. of Physics, Oakayama (Japan); Matsubara, Y. [Nagoya University, Solar-Terrestrial Environment Laboratory, Nagoya, Aichi (Japan); Miranda, P.; Velarde, A. [Universidad Mayor de San Andres, Institute de Investigaciones Fisicas, La Paz (Bolivia); Mizumoto, T. [National Astronomical Observatory, Mitaka, Tokyo (Japan); Yoshii, H.; Morizawa, A. [Ehime University, Dept. of Physics, Matsuyama, Ehime (Japan); Murakami, K. [Nagoya University of Foreign Studies, Nissin, Aichi (Japan); Toyoda, Y. [Fukui University of Technology, Faculty of General Education, Fukui (Japan)

    2001-10-01

    BASJE group has measured the chemical composition of primary cosmic rays with energies around the knee with several methods. These measurements show that the averaged mass number of cosmic ray particles increases with energy up to the knee. In order to measure the chemical composition in much wider energy range, it was started a new experiment at Mt. Chacaltaya in 2000.

  19. Characterization of plasma chemistry and ion energy in cathodic arc plasma from Ti-Si cathodes of different compositions

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, A. O.; Zhirkov, I.; Dahlqvist, M.; Jensen, J.; Hultman, L.; Rosen, J. [Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-581 83 Linkoeping (Sweden)

    2013-04-28

    Arc plasma from Ti-Si compound cathodes with up to 25 at. % Si was characterized in a DC arc system with respect to chemistry and charge-state-resolved ion energy. The plasma ion composition showed a lower Si content, diverging up to 12 at. % compared to the cathode composition, yet concurrently deposited films were in accordance with the cathode stoichiometry. Significant contribution to film growth from neutrals is inferred besides ions, since the contribution from macroparticles, estimated by scanning electron microscopy, cannot alone account for the compositional difference between cathode, plasma, and film. The average ion charge states for Ti and Si were higher than reference data for elemental cathodes. This result is likely related to TiSi{sub x} phases of higher cohesive energies in the compound cathodes and higher effective electron temperature in plasma formation. The ion energy distributions extended up to {approx}200 and {approx}130 eV for Ti and Si, respectively, with corresponding average energies of {approx}60 and {approx}30 eV. These averages were, however, not dependent on Si content in the cathode, except for 25 at. % Si where the average energies were increased up to 72 eV for Ti and 47 eV for Si.

  20. Consolidation of W–Ta composites: Hot isostatic pressing and spark and pulse plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Dias, M., E-mail: marta.dias@itn.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Guerreiro, F. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Correia, J.B. [LNEG, Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar, 1649-038 Lisboa (Portugal); Galatanu, A. [National Institute of Materials Physics, Atomistilor 105 bis Bucharest-Magurele, 077125 Ilfov (Romania); Rosiński, M. [Warsaw University of Technology, Faculty of Materials Science and Engineering, Warsaw (Poland); Monge, M.A.; Munoz, A. [Departamento de Física, Univerdidad Carlos III de Madrid, Avd. de la Universidad 30, 28911 Madrid (Spain); Alves, E. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Carvalho, P.A. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2015-10-15

    Highlights: • Consolidation of W–Ta composites using three techniques: HIP, SPS and PPS. • Comparison of consolidation methods in terms of W–Ta interdiffusion and densification. • Microstructure analysis in terms of oxides formation. - Abstract: Composites consisting of tantalum fiber/powder dispersed in a nanostructured W matrix have been consolidated by spark and pulse plasma sintering as well as by hot isostatic pressing. The microstructural observations revealed that the tungsten–tantalum fiber composites consolidated by hot isostatic pressing and pulse plasma sintering presented a continuous layer of Ta{sub 2}O{sub 5} phase at the W/Ta interfaces, while the samples consolidated by spark plasma sintering evidenced a Ta + Ta{sub 2}O{sub 5} eutectic mixture due to the higher temperature of this consolidation process. Similar results have been obtained for the tungsten–tantalum powder composites. A (W, Ta) solid solution was detected around the prior nanostructured W particles in tungsten–tantalum powder composites consolidated by spark and pulse plasma sintering. Higher densifications were obtained for composites consolidated by hot isostatic pressing and pulse plasma sintering.

  1. 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.

  2. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    OpenAIRE

    Rackel Reis; Dumée, Ludovic F.; Tardy, Blaise L.; Raymond Dagastine; John D. Orbell; Jürg A. Schutz; Duke, Mikel C.

    2016-01-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membra...

  3. Low-temperature oxidizing plasma surface modification and composite polymer thin-film fabrication techniques for tailoring the composition and behavior of polymer surfaces

    Science.gov (United States)

    Tompkins, Brendan D.

    This dissertation examines methods for modifying the composition and behavior of polymer material surfaces. This is accomplished using (1) low-temperature low-density oxidizing plasmas to etch and implant new functionality on polymers, and (2) plasma enhanced chemical vapor deposition (PECVD) techniques to fabricate composite polymer materials. Emphases are placed on the structure of modified polymer surfaces, the evolution of polymer surfaces after treatment, and the species responsible for modifying polymers during plasma processing. H2O vapor plasma modification of high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), and 75A polyurethane (PU) was examined to further our understanding of polymer surface reorganization leading to hydrophobic recovery. Water contact angles (wCA) measurements showed that PP and PS were the most susceptible to hydrophobic recovery, while PC and HDPE were the most stable. X-ray photoelectron spectroscopy (XPS) revealed a significant quantity of polar functional groups on the surface of all treated polymer samples. Shifts in the C1s binding energies (BE) with sample age were measured on PP and PS, revealing that surface reorganization was responsible for hydrophobic recovery on these materials. Differential scanning calorimetry (DSC) was used to rule out the intrinsic thermal properties as the cause of reorganization and hydrophobic recovery on HDPE, LDPE, and PP. The different contributions that polymer cross-linking and chain scission mechanisms make to polymer aging effects are considered. The H2O plasma treatment technique was extended to the modification of 0.2 microm and 3.0 microm track-etched polycarbonate (PC-TE) and track-etched polyethylene terephthalate (PET-TE) membranes with the goal of permanently increasing the hydrophilicity of the membrane surfaces. Contact angle measurements on freshly treated and aged samples confirmed the wettability of the

  4. Simplified micromethod for the HPLC measurement of diclofenac in plasma.

    Science.gov (United States)

    Santos, S R; Donzella, H; Bertoline, M A; Pereira, M D; Omosako, C E; Porta, V

    1992-01-01

    A simple and sensitive micromethod based on HPLC is described for the measurement of diclofenac in 200 microliters plasma. A single extraction with dichloromethane in acidic medium was an essential clean-up step. Diclofenac and its internal standard (cyclohexendiphenyl propionic acid) was eluted at 3.3 and 6.5 min from a 4-micron C18 reverse-phase column using a mobile phase consisting of 0.75 M sodium acetate buffer, pH 5.0, and acetonitrile (55:45, v/v) at a flow rate of 0.9 ml/min with detection at 282 nm. The method, validated on the basis of parameters evaluated for the confidence limits of diclofenac measurements in spiked plasma, presented 1 ng/ml sensitivity, 10-10,000 ng/ml linearity, and 3.5% and 5.7% intra- and interassay precision, respectively. Peak plasma diclofenac levels ranging from 177 to 841 ng/ml and from 276 to 1008 ng/ml were obtained for two slow-release formulations. A wide range (1 ng/ml-3 micrograms/ml) was observed for plasma diclofenac levels of volunteers during a 24-h study period.

  5. Strongly correlated two-dimensional plasma explored from entropy measurements.

    Science.gov (United States)

    Kuntsevich, A Y; Tupikov, Y V; Pudalov, V M; Burmistrov, I S

    2015-06-23

    Charged plasma and Fermi liquid are two distinct states of electronic matter intrinsic to dilute two-dimensional electron systems at elevated and low temperatures, respectively. Probing their thermodynamics represents challenge because of lack of an adequate technique. Here, we report a thermodynamic method to measure the entropy per electron in gated structures. Our technique appears to be three orders of magnitude superior in sensitivity to a.c. calorimetry, allowing entropy measurements with only 10(8) electrons. This enables us to investigate the correlated plasma regime, previously inaccessible experimentally in two-dimensional electron systems in semiconductors. In experiments with clean two-dimensional electron system in silicon-based structures, we traced entropy evolution from the plasma to Fermi liquid regime by varying electron density. We reveal that the correlated plasma regime can be mapped onto the ordinary non-degenerate Fermi gas with an interaction-enhanced temperature-dependent effective mass. Our method opens up new horizons in studies of low-dimensional electron systems.

  6. Simulated plasma facing component measurements for an in situ surface diagnostic on Alcator C-Moda)

    Science.gov (United States)

    Hartwig, Z. S.; Whyte, D. G.

    2010-10-01

    The ideal in situ plasma facing component (PFC) diagnostic for magnetic fusion devices would perform surface element and isotope composition measurements on a shot-to-shot (˜10 min) time scale with ˜1 μm depth and ˜1 cm spatial resolution over large areas of PFCs. To this end, the experimental adaptation of the customary laboratory surface diagnostic—nuclear scattering of MeV ions—to the Alcator C-Mod tokamak is being guided by ACRONYM, a Geant4 synthetic diagnostic. The diagnostic technique and ACRONYM are described, and synthetic measurements of film thickness for boron-coated PFCs are presented.

  7. Plasma Transferred ARC (PTA Hardfacing of Recycled Hardmetal Reinforced Nickel-matrix Surface Composites

    Directory of Open Access Journals (Sweden)

    Arkadi ZIKIN

    2012-03-01

    Full Text Available The aim of this work was to apply coarse recycled hardmetal particles in combination with Ni-based matrix to produce wear resistant metal matrix composite (MMC thick coatings using plasma transferred arc hardfacing (PTA technology. Assignment of hardmetal waste as initial material can significantly decrease the production costs and improve the mechanical properties of coatings and, consequently, increase their wear resistance. The microstructure of MMC fabricated from a recycled powder was examined by optical and SEM/EDS microscopes, whereas quantitative analyses were performed by image analysis method. Micro-mechanical properties, including hardness and elastic modulus of features, were measured by nanoindentation. Furthermore, behaviour of materials subjected to abrasive and impact conditions was studied. Results show the recycled powder provides hardfacings of high quality which can be successfully used in the fabrication of wear resistant MMC coatings by PTA-technology.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1334

  8. Expanded Ion Energy Distribution Measurements on MST RFP Plasmas

    Science.gov (United States)

    Clark, Jerry; Titus, J. B.; Mezonlin, E. D.; Anderson, J. K.; Almagri, A. F.

    2016-10-01

    The Compact Neutral Particle Analyzer (CNPA) is a low energy (0.34 - 5.2 keV), high energy resolution (25 channels) neutral particle analyzer for ion energy distribution and temperature measurements on the Madison Symmetric Torus (MST). In MST plasmas during neutral beam injection, deuterium ions are known to have energies out to 40 keV. A retarding potential was built, installed, and calibrated to allow CNPA measurements to explore this region with high energy resolution, expanding ion energy distribution measurements, allowing us to better understand the dynamics of the bulk and fast ion populations during global magnetic reconnection events. Work supported by US DOE and NSF.

  9. Metabolic Rather Than Body Composition Measurements Are Associated With Lower Serum Natriuretic Peptide Concentrations in Normal Weight and Obese Men

    DEFF Research Database (Denmark)

    Asferg, Camilla L; Nielsen, Søren J; Andersen, Ulrik B

    2014-01-01

    men (BMI ≥ 30kg/m(2)), we determined body composition (total, android, and gynoid fat mass) by dual energy x-ray absorptiometry scanning, and we measured fasting serum concentrations of midregional proatrial NP (MR-proANP) and insulin, as well as fasting plasma glucose concentrations. RESULTS: Mean.......0001) and plasma glucose concentrations (β = -0.21; P = 0.02) but not with total (β = 0.00), android (β = -0.01), or gynoid (β = 0.03) fat mass percentage (P > 0.76). No significant interaction effects between metabolic measurements or body composition measurements and weight status on MR-proANP concentrations...

  10. Application of cold plasma technology in fiber-reinforced composite materials

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A study is presented concerning a cold plasma technique for improving the bondability of highstrength high-modulus multi-filament polyethylene fibers to polymer matrices and the fibers impregnation with the objective to fabricate composite materials (CMs). Strong bonding between the matrixes and reinforcing fibers during the production of composites appears in the case if interaction is chemical. The value of the activation energy of the chemical interaction for very high performance polyethylene fiber was estimated. It was 1.14 eV. This allows using the cold plasma technique for producing CMs. In order to understand the effect of cold plasma treatment treated and untreated fibers were used to fabricate CMs. The strong bond between the matrix and plasma-activated fibers affects both the properties and failure mode of composite. The properties and failure modes were compared to those of CMs reinforced with untreated fibers. After plasma treatment the properties of CMs are increased. CMs are broken as a unit whole under tension. The ideas of the activating the fibers by cold plasma treatment above the activation energy of the chemical interaction may be extended over other types of the fibers and matrices to produce new types of fiber-reinforced composite materials with high physicomechanical indices.

  11. Pulse compression radar reflectometry for density measurements on fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Costley, A.; Prentice, R. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Laviron, C. [Compagnie Generale des Matieres Nucleaires (COGEMA), 78 - Velizy-Villacoublay (France); Prentice, R. [Toulouse-3 Univ., 31 (France). Centre d`Etude Spatiale des Rayonnements

    1994-07-01

    On tokamaks and other toroidal machines, reflectometry is a very rapidly developing technique for density profile measurements, particularly near the edge. Its principle relies on the total reflection of an electromagnetic wave at a cutoff layer, where the critical density is reached and the local refractive index goes to zero. With the new fast frequency synthesizers now available, a method based on pulse compression radar is proposed for plasma reflectometry, overcoming the limitations of the previous reflectometry methods. The measurement can be made on a time-scale which is effectively very short relatively to the plasma fluctuations, and the very high reproducibility and stability of the source allows an absolute calibration of the waveguides to be made, which corrects for the effects of the parasitic reflections. 2 refs., 5 figs.

  12. Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; N.J. Fisch

    2001-10-16

    Use of a segmented electrode placed at the Hall thruster exit can substantially reduce the voltage potential drop in the fringing magnetic field outside the thruster channel. In this paper, we investigate the dependence of this effect on thruster operating conditions and segmented electrode configuration. A fast movable emissive probe is used to measure plasma potential in a 1 kW laboratory Hall thruster with semented electrodes made of a graphite material. Relatively small probe-induced perturbations of the thruster discharge in the vicinity of the thruster exit allow a reasonable comparison of the measured results for different thruster configurations. It is shown that the plasma potential distribution is almost not sensitive to changes of the electrode potential, but depends on the magnetic field distribution and the electrode placement.

  13. The plasma composition of karakul lambs fed isocaloric high- and ...

    African Journals Online (AJOL)

    plasma concentrations of glucose, free fatty acids (FFA), lactate, insulin and glucagon were determined. Differ- ences in the ... Insulin levels were higher (p < 0.05) in the HF than in the LF lambs ..... Normal tissue growth may be influenced by metabolic hormones ... short experimental period (12 weeks), the masking effect of.

  14. Spectroscopy Measurements on Ablation Testing in High Enthalpy Plasma Flows

    Science.gov (United States)

    2010-11-01

    stagnation point, are located on the ablative material sample. 3.5 InfraRed THERMOGRAPHY Surface temperature measurement is a topic of great concern...high temperature material at two different narrow wavelengths. The temperature is calculated by building the ratio of the radiation intensities. The...this work is to develop the capability of testing and characterization of ablative materials exposed to high enthalpy plasma flows including both

  15. A viscometric method of measuring plasma fibrinogen concentrations.

    OpenAIRE

    Ernst, E.; Resch, K L; Saradeth, T.; A. Maier; Matrai, A

    1992-01-01

    A technique based on deducing the viscosity of serum from that of plasma was compared with the commonly used Clauss method. The two methods correlated closely (r = 0.914). The reproducibility of the viscometric method was slightly poorer than the Clauss technique at low fibrinogen concentrations, equal to that at medium fibrinogen concentrations, and marginally better at high concentrations. Fibrinogen can therefore be measured reasonably accurately with the viscometric method, and can be rec...

  16. Composition Measurements from ISEE-3: Fluorine through Calcium

    Science.gov (United States)

    Leske, Richard A.; Wiedenbeck, Mark E.

    1993-01-01

    Spacecraft measurements are reported of the elemental composition of galactic cosmic rays with 9 less than or equal to Z less than or equal to 20 at energies approximately 220 MeV/nucleon. In addition, for the elements with 16 less than or equal to Z less than or equal to 20 isotopic composition results are reported. The measured composition is found to be in generally good agreement with that expected from a propagated solar-like source.

  17. Deposition and properties of high-velocity-oxygen-fuel and plasma-sprayed Mo-Mo2C composite coatings

    Science.gov (United States)

    Prchlik, L.; Gutleber, J.; Sampath, S.

    2001-12-01

    Molybdenum thermal-spray coatings, dispersion strengthened by molybdenum oxides and molybdenum carbides, play an important role in industrial tribological applications. Traditionally, they have been prepared by plasma and wire flame spraying. High porosity and lower cohesion strength limit their application in situations where both galling and abrasion wear is involved. In this study, high-velocity-oxygen-fuel (HVOF) deposition of molybdenum and molybdenum carbide coatings was attempted. Deposition was achieved for all powders used. Composition, microstructure, mechanical, and wear properties of the HVOF synthesized coatings were evaluated and compared with plasma-sprayed counterparts. The HVOF coatings possessed a very good abrasion resistance, whereas plasma deposits performed better in dry sliding tests. Measurements showed a close relationship between the coating surface hardness and its abrasion resistance. Results also suggested correlation between molybdenum carbide distribution in the molybdenum matrix and the sliding friction response of Mo-Mo2C coatings.

  18. Long-term variations in the plasma sheet ion composition and substorm occurrence over 23 years

    Science.gov (United States)

    Nosé, Masahito

    2016-12-01

    The Geotail satellite has been operating for almost two solar cycles (~23 years) since its launch in July 1992. The satellite carries the energetic particle and ion composition (EPIC) instrument that measures the energetic ion flux (9.4-212 keV/e) and enables the investigation of long-term variations of the ion composition in the plasma sheet for solar cycles 22-24. From the statistical analysis of the EPIC data, we find that (1) the plasma ion mass ( M) is approximately 1.1 amu during the solar minimum, whereas it increases to 1.5-2.7 amu during the solar maximum; (2) the increases in M seem to have two components: a raising of the baseline levels (~1.5 amu) and a large transient enhancement (~1.8-2.7 amu); (3) the baseline level change of M correlates well with the Mg II index, which is a good proxy for the solar extreme ultraviolet (EUV) or far ultraviolet (FUV) irradiance; and (4) the large transient enhancement of M is caused by strong magnetic storms. We also study the long-term variations of substorm occurrences in 1992-2015 that are evaluated with the number of Pi2 pulsations detected at the Kakioka observatory. The results suggest no clear correlation between the substorm occurrence and the Mg II index. Instead, when the substorms are classified into externally triggered events and non-triggered events, the number of the non-triggered events and the Mg II index are negatively correlated. We interpret these results that the increase in the solar EUV/FUV radiation enhances the supply of ionospheric ions (He+ and O+ ions) into the plasma sheet to increase M, and the large M may suppress spontaneous plasma instabilities initiating substorms and decrease the number of the non-triggered substorms. The present analysis using the unprecedentedly long-term dataset covering ~23 years provides additional observational evidence that heavy ions work to prevent the occurrence of substorms.

  19. Optimum condition of anisotropic plasma etching for improving bending properties of ionic polymer-metal composites.

    Science.gov (United States)

    Choi, N J; Lee, H K; Jung, S; Park, K H

    2010-05-01

    We presented an anisotropic plasma etching technique by reactive ion etcher (RIE) as a new pretreatment method of fabrication of ionic polymer-metal composite (IPMC). We already found that the new technique provided large displacement to the fabricated IPMC in the presence of low applied voltage. However, we did not examine the optimum condition for the anisotropic plasma etching. In this research, we tried to figure out optimum treatment condition of film in etcher. Nafion (by DuPont) films were etched using various etching time and shadow masks with various slit and space sizes. The etched samples were plated with Pt at top and bottom side by Oguro's reduction method. The surface morphology of fabricated IPMCs was characterized by SEM. And, we've measured surface resistance, bending displacement, and driving force in order to check the IPMC properties out. Here, we found that optimum condition for pre-treatment of Nafion was 1 min for etching time under shadow mask with 200 microm slit and 100 microm space.

  20. Titanium carbide/carbon composite nanofibers prepared by a plasma process

    Energy Technology Data Exchange (ETDEWEB)

    El Mel, A A; Gautron, E; Angleraud, B; Granier, A; Tessier, P Y [Universite de Nantes, CNRS, Institut des Materiaux Jean Rouxel, UMR 6502, 2 rue de la Houssiniere BP 32229-44322 Nantes cedex 3 (France); Choi, C H [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  1. Titanium carbide/carbon composite nanofibers prepared by a plasma process.

    Science.gov (United States)

    El Mel, A A; Gautron, E; Choi, C H; Angleraud, B; Granier, A; Tessier, P Y

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  2. Control of collective FSBS and backscatter SRS through plasma composition

    Science.gov (United States)

    Rose, Harvey; Lushnikov, Pavel

    2005-10-01

    Nominal NIF parameters are near the collective forward SBS (FSBS) threshold (P. M. Lushnikov and H. A. Rose, Phys. Rev. Lett. 92, 255003 (2004), ``L&R''). It will be shown that being on this instability edge can be used as a control lever: a small amount of high Z dopant may lead to qualitative change in FSBS regime at fixed laser intensity, possibly reducing backscatter instability losses (Such results have already been observed, but absent SSD, a key aspect of our theory: R. M. Stevenson et al., Phys. Plasmas 11, 2709 (2004); L. J. Suter et al., 2738, ib.). Ponderomotive FSBS regimes are determined by the parameter I=F^2( vosc / vosc ve . - ve )^2( ne / ne nc . - nc ) / ( ne / ne nc . - nc ) ν . - ν, with ν the dimensionless ion acoustic damping coefficient and F the optic f/#. Analytical results will be presented which show a decrease of I1pt's threshold value through the addition of high Z dopant to low Z plasma, owing to increased thermal contribution to FSBS. Alternatively, one may raise the threshold by managing the value of νby, e.g., adding He to SiO2. For nominal NIF parameters, a range of He fraction in SiO2 plasma is predicted to suppress backscatter SRS while maintaining control of forward SBS.

  3. Spatial and Temporal Investigations of Laser Ablation Plasma Plume Density and Composition

    Science.gov (United States)

    Iratcabal, Jeremy; Bach, Bernhard; Beatty, Cuyler; Dutra, Eric; Darling, Timothy; Wiewior, Piotr; Covington, Aaron

    2016-10-01

    Laser ablation of solid targets with laser intensities of the order of 108-1011 W/cm2 provides a rich platform for investigating the density and composition of coexisting molecular, atomic, and ion species in the resulting plasma plume. Experiments measuring the spatial- and temporal-evolution of laser ablation plumes have been performed to simultaneously characterize the multiple parameters related to the energy and momentum partitioning of the incident laser energy as the ablation process occurs. The temperature, density, and relative populations of different molecular, atomic, and ion species can be determined by the simultaneous measurement of optical and charged particle spectroscopy, fast imaging cameras, and optical interferometric diagnostics. Additionally, background gas pressure, density, and species were carefully varied. A comparison of density measurements obtained with multiple interferometric, spectroscopic, and fast imaging diagnostics for a carbon ablation plume expanding into vacuum and into background gases with different Reynolds numbers will be presented. Atomic, molecular, and ion species population evolution will be presented as measured with optical and charged particle spectroscopy. This work was supported by the U.S. DOE NNSA Cooperative Agreement No. DE-NA0002075 and National Securities Technologies, LLC under Contract No. DE-AC52-06NA25946/subcontract No. 165819.

  4. Survey of 0. 1- to 16-keV/e plasma sheet ion composition

    Energy Technology Data Exchange (ETDEWEB)

    Lennartsson, W.; Shelley, E.G.

    1986-03-01

    A large statistical survey of the 0.1- to 16-keV/e plasma sheet ion composition has been carried out using data obtained by the Plasma Composition Experiment on ISEE 1 between 10 and 23 R/sub E/ during 1978 and 1979. This survey includes more than 10 times the quantity of data used in earlier studies of the same topic and makes it possible to investigate in finer detail the relationship between the ion composition and the substorm activity. The larger data base also makes it possible for the first time to study the spatial distribution of the principal ion species. As found in previous studies, the ion composition has a large variance at any given value of the AE index, but a number of distinct trends emerge when the data are averaged at each activity level. During quiet conditions the plasma sheet is dominated by ions of solar origin (H/sup +/ and He/sup + +/), as found in earlier studies, and these ions are most numerous during extended periods of very low activity (AE< or approx. =30 ..gamma..). The quiet time density of these ions is particularly large in the flanks of the plasma sheet (GSM Yapprox. +- 10 R/sub E/), where it is about twice as large as it is near the central axis of the plasma sheet (Y = Z = 0). In contrast, the energy of these ions peaks near the central axis.

  5. Characterization of Mullite-Zirconia Composite Processed by Non-Transferred and Transferred Arc Plasma

    Institute of Scientific and Technical Information of China (English)

    S. YUGESWARAN; V. SELVARAJAN; L. LUSVARGHI; A. I. Y. TOK; D. SIVA RAMA KRISHNA

    2009-01-01

    The arc plasma melting technique is a simple method to synthesize high temperature reaction composites. In this study, mullite-zirconia composite was synthesized by transferred and non-transferred arc plasma melting, and the results were compared. A mixture of alumina and zircon powders with a mole ratio of 3 : 2 were ball milled for four hours and melted for two minutes in the transferred and non-transferred mode of plasma arcs. Argon and air were used as plasma forming gases. The phase and microstructural formation of melted samples were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The microstructure of the com-posites was found to be affected by the mode of melting. In transferred arc melting, zirconia flowers with uniform lines along with mullite whiskers were obtained. In the case of non-transferred arc plasma melting, mullite whiskers along with star shape zirconia were formed. Differential thermal analysis (DTA) of the synthesized mullite-zirconia composites provided a deeper understanding of the mechanisms of mullite formation during the two different processes.

  6. Material measurement method based on femtosecond laser plasma shock wave

    Science.gov (United States)

    Zhong, Dong; Li, Zhongming

    2017-03-01

    The acoustic emission signal of laser plasma shock wave, which comes into being when femtosecond laser ablates pure Cu, Fe, and Al target material, has been detected by using the fiber Fabry-Perot (F-P) acoustic emission sensing probe. The spectrum characters of the acoustic emission signals for three kinds of materials have been analyzed and studied by using Fourier transform. The results show that the frequencies of the acoustic emission signals detected from the three kinds of materials are different. Meanwhile, the frequencies are almost identical for the same materials under different ablation energies and detection ranges. Certainly, the amplitudes of the spectral character of the three materials show a fixed pattern. The experimental results and methods suggest a potential application of the plasma shock wave on-line measurement based on the femtosecond laser ablating target by using the fiber F-P acoustic emission sensor probe.

  7. Global Time Variability in the Thermal Plasma Composition of the Saturnian Magnetosphere

    Science.gov (United States)

    Ip, W.

    2013-12-01

    The Saturnian magnetosphere is characterized by strong coupling between the charged particles and the neutral gas cloud emitted from Enceladus and the rings. Besides the mass-loading effect due to ionization of the water-group gas, the charge transfer process leading to the generation of energetic neutral atoms is a key process of particle loss and atmospheric precipitation. Detailed measurements by the plasma instruments like CAPS and MIMI have provided many insights to the magnetospheric composition and dynamics driven by such plasma-gas interaction. For example, a statistical study of the CAPS measurements by Thomsen et al. (2010) has shown the relative abundances and radial profiles of different ion species in the corotating thermal plasma disc. Another interesting result has to do with the seasonal variability of the suprathermal O2+ molecular ions detected by the CHEMS/MIMI experiment (Christon et al., 2013) which might have to do with the extended oxygen atmosphere of the ring system (Tseng et al., 2010). In this work, we will use a time-dependent radial diffusion transport model coupled with ion chemistry calculation (Ip, 2000) to simulate the global distributions of various ions (H+, H2+, O+, OH+, H2O+, H3O+, and O2+ )between the outer edge of the A ring to the orbit of Titan. Our parametric study will examine how the thermal ion composition of the Saturnian magnetosphere would be affected by solar cycle effect, seasonal variation of the ring atmosphere, and the suprathermal electron flux. Christon, S.P., Hamilton, D.C., DiFabio, R.D., Mitchell, D.G., Krimigis, S.M., and Jontof-Hutter, D.S., J. Geophys. Res., 118, 3446-3462, 2013. Ip, W.-H., Planet. Space Sci., 48, 775-783, 2000. Thomsen, M.F., Reisenfeld, D.B., Delapp, D.M., Tokar, R.C., Young, D.T., Crary, F.J., Sittler, E.C., McGraw, M.A., and Williams, J.D., J. Geophys. Res., 115, A10220, 2010. Tseng, W.-L., Ip, W.-H., Johnson, R.E., Cassidy, T.A., and Elrod, M.K., Icarus, 206, 382-389, 2010.

  8. Confocal microscopy: A new tool for erosion measurements on large scale plasma facing components in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, E., E-mail: eric.gauthier@cea.fr [CEA/DSM/IRFM, CEA Cadarache, Saint-Paul-lez-Durance (France); Brosset, C.; Roche, H.; Tsitrone, E.; Pégourié, B.; Martinez, A. [CEA/DSM/IRFM, CEA Cadarache, Saint-Paul-lez-Durance (France); Languille, P. [PIIM, CNRS-Université de Provence, Centre de St Jérôme, 13397 Marseille, Cedex 20 (France); Courtois, X.; Lallier, Y. [CEA/DSM/IRFM, CEA Cadarache, Saint-Paul-lez-Durance (France); Salami, M. [AVANTIS CONCEPT, 75 Rue Marcelin Berthelot, 13858 Aix en Provence (France)

    2013-07-15

    A diagnostic based on confocal microscopy was developed at CEA Cadarache in order to measure erosion on large plasma facing components during shutdown in situ in Tore Supra. This paper describes the diagnostic and presents results obtained on Beryllium and Carbon Fibre Composite (CFC) materials. Erosion in the range of 800 μm was found on one sector of the Toroidal Pumped Limiter (TPL) which provides, by integration to the full limiter a net carbon erosion of about 900 g over the period 2002–2007.

  9. Measurement of plasma hydrogen sulfide in vivo and in vitro.

    Science.gov (United States)

    Shen, Xinggui; Pattillo, Christopher B; Pardue, Sibile; Bir, Shyamal C; Wang, Rui; Kevil, Christopher G

    2011-05-01

    The gasotransmitter hydrogen sulfide is known to regulate multiple cellular functions during normal and pathophysiological states. However, a paucity of concise information exists regarding quantitative amounts of hydrogen sulfide involved in physiological and pathological responses. This is primarily due to disagreement among various methods employed to measure free hydrogen sulfide. In this article, we describe a very sensitive method of measuring the presence of H₂S in plasma down to nanomolar levels, using monobromobimane (MBB). The current standard assay using methylene blue provides erroneous results that do not actually measure H₂S. The method presented herein involves derivatization of sulfide with excess MBB in 100 mM Tris-HCl buffer (pH 9.5, 0.1 mM DTPA) for 30 min in 1% oxygen at room temperature. The fluorescent product sulfide-dibimane (SDB) is analyzed by RP-HPLC using an eclipse XDB-C18 (4.6 × 250 mm) column with gradient elution by 0.1% (v/v) trifluoroacetic acid in acetonitrile. The limit of detection for sulfide-dibimane is 2 nM and the SDB product is very stable over time, allowing batch storage and analysis. In summary, our MBB method is suitable for sensitive quantitative measurement of free hydrogen sulfide in multiple biological samples such as plasma, tissue and cell culture lysates, or media.

  10. Phase stress measurements in composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Akiniwa, Yoshiaki; Tanaka, Keisuke [Nagoya Univ. (Japan). School of Engineering

    1997-06-01

    Using an aluminum alloy composite containing 20 wt.% of SiC powder and an aluminum alloy itself, a phase stress under monoaxial tensile load was tested using x-ray and neutron methods, to compare both of them. For specimens, a 20 vol.% SiC powder reinforced aluminum alloy and an aluminum alloy itself were used. As a result, the following results could be obtained. Young`s modulus and Poisson ratio of the aluminum alloy itself using x-ray method were E=74.5 GPa and {nu}=0.312, respectively, and those using neutron method were E=75.3 GPa and {nu}=0.384, respectively. A relationship between loading stress and lattice strain of the aluminum alloy itself using neutron method was possible to approximate linearly by containing macroscopic plastic deformation region. The lattice strain of each phase in the composite increased proportionally with loading stress in its elastic region, but when remarkably increasing plastic deformation, the lattice strain decreased proportionally in aluminum phase and increased in SiC phase. (G.K.)

  11. Reactive Spark Plasma Sintering (SPS) of Nitride Reinforced Titanium Alloy Composites (Postprint)

    Science.gov (United States)

    2014-08-15

    ies on in situ alloying and reactions during the SPS process. A recent study on SPS processing of hafnium carbide (HfC) starting from a blend of...AFRL-RX-WP-JA-2014-0177 REACTIVE SPARK PLASMA SINTERING (SPS) OF NITRIDE REINFORCED TITANIUM ALLOY COMPOSITES (POSTPRINT) Jaimie S...SINTERING (SPS) OF NITRIDE REINFORCED TITANIUM ALLOY COMPOSITES (POSTPRINT) 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  12. Preparation of Al-SiC{sub p} composite coating by plasma thermal spray

    Energy Technology Data Exchange (ETDEWEB)

    Min, J.W. [Chungnam National University, Taejeon (Korea); Yoo, S.E. [Korea Automotive Technology Institute, Chonan (Korea); Kim, Y.J. [Sunmoon University, Asan (Korea); Kim, J.S.; Suhr, D.S. [Chungnam National University, Taejeon (Korea)

    2003-03-01

    Al-SiC{sub p} composite layer was prepared by plasma thermal spray on aluminum substrate using composite powder prepared by mechanical alloying. Mechanically alloyed powder was achieved after 24 h milling, which was used for thermal spray coating. The correlations between process conditions and thickness/porosity were analyzed, and increase of hardness was confirmed. The presence of Al-Si-C-O compound was detected by TEM analysis. (author). 16 refs., 6 tabs., 11 figs.

  13. Analysis of lipid-composition changes in plasma membrane microdomains.

    Science.gov (United States)

    Ogiso, Hideo; Taniguchi, Makoto; Okazaki, Toshiro

    2015-08-01

    Sphingolipids accumulate in plasma membrane microdomain sites, such as caveolae or lipid rafts. Such microdomains are considered to be important nexuses for signal transduction, although changes in the microdomain lipid components brought about by signaling are poorly understood. Here, we applied a cationic colloidal silica bead method to analyze plasma membrane lipids from monolayer cells cultured in a 10 cm dish. The detergent-resistant fraction from the silica bead-coated membrane was analyzed by LC-MS/MS to evaluate the microdomain lipids. This method revealed that glycosphingolipids composed the microdomains as a substitute for sphingomyelin (SM) in mouse embryonic fibroblasts (tMEFs) from an SM synthase 1/2 double KO (DKO) mouse. The rate of formation of the detergent-resistant region was unchanged compared with that of WT-tMEFs. C2-ceramide (Cer) stimulation caused greater elevations in diacylglycerol and phosphatidic acid levels than in Cer levels within the microdomains of WT-tMEFs. We also found that lipid changes in the microdomains of SM-deficient DKO-tMEFs caused by serum stimulation occurred in the same manner as that of WT-tMEFs. This practical method for analyzing membrane lipids will facilitate future comprehensive analyses of membrane microdomain-associated responses.

  14. Measurements of conductivity nonuniformities and fluctuations in combustion MHD plasmas

    Science.gov (United States)

    Kowalik, R. M.

    1980-03-01

    Diagnostics for the characterization of electrical conductivity nonuniformities in combustion magnetohydrodynamic (MHD) plasmas were developed. An initial characterization of nonuniformities in the Stanford M-2 linear generator was obtained and recommendations were made concerning the use of the diagnostics in practical MHD generator configurations. A laser induced fluorescene (LIF) diagnostic for nonintrusive measurements of local conductivity fluctuations was developed. This diagnostic and other line of sight averaged optical nonuniformity diagnostics were successfully demonstrated in several experiments in the Standford M-2 combustion systems. Results were used to characterize the nonuniformities in the M-2 system and to compare and evaluate the diagnostics. Conductivity nonuniformities were found to be predominantly streamers which had relatively long length scales of the order of l m in the axial flow direction. Shortet transverse length scales of the order of 0.1 m were found perpendicular to the flow direction. A combination of LIF and plasma luminosity diagnostics is recommended for future characterizations of conductivity uniformities in combustion MHD plasmas.

  15. Statistical analysis of plasma thermograms measured by differential scanning calorimetry.

    Science.gov (United States)

    Fish, Daniel J; Brewood, Greg P; Kim, Jong Sung; Garbett, Nichola C; Chaires, Jonathan B; Benight, Albert S

    2010-11-01

    Melting curves of human plasma measured by differential scanning calorimetry (DSC), known as thermograms, have the potential to markedly impact diagnosis of human diseases. A general statistical methodology is developed to analyze and classify DSC thermograms to analyze and classify thermograms. Analysis of an acquired thermogram involves comparison with a database of empirical reference thermograms from clinically characterized diseases. Two parameters, a distance metric, P, and correlation coefficient, r, are combined to produce a 'similarity metric,' ρ, which can be used to classify unknown thermograms into pre-characterized categories. Simulated thermograms known to lie within or fall outside of the 90% quantile range around a median reference are also analyzed. Results verify the utility of the methods and establish the apparent dynamic range of the metric ρ. Methods are then applied to data obtained from a collection of plasma samples from patients clinically diagnosed with SLE (lupus). High correspondence is found between curve shapes and values of the metric ρ. In a final application, an elementary classification rule is implemented to successfully analyze and classify unlabeled thermograms. These methods constitute a set of powerful yet easy to implement tools for quantitative classification, analysis and interpretation of DSC plasma melting curves.

  16. Flowing dusty plasma experiments: generation of flow and measurement techniques

    Science.gov (United States)

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

    2016-12-01

    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 device with micron size kaolin/melamine formaldehyde particles embedded in a background of argon plasma created by a direct current 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 code, particle image velocimetry analysis and the excitation of dust acoustic waves. The results obtained from these three different techniques along with their merits and demerits are discussed. An estimation of the neutral drag force responsible for the generation as well as the attenuation of the dust fluid flow is made. These techniques can be usefully employed in laboratory devices to investigate linear and non-linear collective excitations in a flowing dusty plasma.

  17. Diagnostic techniques for measuring suprathermal electron dynamics in plasmas (invited).

    Science.gov (United States)

    Coda, S

    2008-10-01

    Plasmas, both in the laboratory and in space, are often not in thermodynamic equilibrium, and the plasma electron distribution function is accordingly non-Maxwellian. Suprathermal electron tails can be generated by external drives, such as rf waves and electric fields, or internal ones, such as instabilities and magnetic reconnection. The variety and importance of the phenomena in which suprathermal electrons play a significant role explains an enduring interest in diagnostic techniques to investigate their properties and dynamics. X-ray bremsstrahlung emission has been studied in hot magnetized plasmas for well over two decades, flanked progressively by electron-cyclotron emission in geometries favoring the high-energy end of the distribution function (high-field-side, vertical, oblique emission), by electron-cyclotron absorption, by spectroscopic techniques, and at lower temperatures, by Langmuir probes and electrostatic analyzers. Continuous progress in detector technology and in measurement and analysis techniques, increasingly sophisticated layouts (multichannel and tomographic systems, imaging geometries), and highly controlled suprathermal generation methods (e.g., perturbative rf modulation) have all been brought to bear in recent years on an increasingly detailed, although far from complete, understanding of suprathermal electron dynamics.

  18. COMPOSITE IMPULSED-PLASMA COATING «STEEL T1/CAST IRON CR28MN3»

    Directory of Open Access Journals (Sweden)

    Y. G. Chabak

    2017-06-01

    Full Text Available Purpose. The article is aimed to investigate the structure of the composite coating obtained by pulse-plasma treatment using cathodes of high-carbon material with higher amount of carbide-forming elements. Methodology. The coating was produced using electrothermal axial plasma accelerator with the following operating parameters: voltage applied to the electrodes is 4.0 kV; amplitude of the current is 18 kA; distance between electrodes of about 50 mm. The treatment was carried out according to the scheme: five pulses with electrode of steel T1 + five pulses with electrode of cast iron Cr28Mn3. The pulsed plasma treatment was followed by heat treatment as holding at 950 °C for 2 hours, followed by oil cooling. Optical (Nikon Eclipse L150 and electron (JEOL JSM-6510 microscopy, energy dispersive spectroscopy (X-Act, Oxford Instruments, the microhardness measurement (FM-300 Future-Tech Corp. were used for microstructure studying. Findings. It is shown that pulsed-plasma treatment using various electrodes resulted in formation of laminated coating «P18 steel/cast iron 230Cr28Mn3» of 110-130 microns thick. The analysis of micro-hardness coating before and after the post-plasma heat treatment is carried out. It is found that quenching resulted in increase of coating microhardness from 4900-7300 МPа tо 10500-13500 МPа (layer “T1” and 12000-16500 МPа (layer “230Cr28Mn3”. Originality. The distribution of the alloying elements within the coating is studied. The diffusion transition layer having variable tungsten and chromium content was revealed between the layer “T1” and layer “230Cr28Mn3”. It was shown that after plasma deposition an oversaturated solid solution is being formed in the coating. During post-heat treatment it decomposes with the precipitation of 45-70 % carbides of different shape resulting in sharp increase of microhardness. Carbides amount is proportional to content of carbon and carbide-forming elements in the

  19. A small-amplitude study of solitons near critical plasma compositions

    Science.gov (United States)

    Olivier, Carel P.; Verheest, Frank; Maharaj, Shimul K.

    2016-12-01

    The properties of small-amplitude solitons are established near critical plasma compositions in a generalized fluid plasma with an arbitrary number of species. The study is conducted via a Taylor series expansion of the Sagdeev potential. It is shown that there are two types of critical compositions, namely rich critical and poor critical compositions. The coexistence of positive and negative polarity solitons is shown to arise at rich critical compositions and near rich critical compositions. At poor critical compositions, no small-amplitude solitons exist, while weak double layers arise near poor critical compositions. A novel analytical expression is obtained for a small-amplitude acoustic speed soliton solution near rich critical compositions. These solitons have a Lorentzian shape with much fatter tails than regular solitons. A case study is also performed for a simple fluid model consisting of cold ions and two Boltzmann electron species. Exact agreement is obtained between the Sagdeev analysis and reductive perturbation theory. For the first time, we derive the same Lorentzian acoustic speed soliton from reductive perturbation theory.

  20. On bias of kinetic temperature measurements in complex plasmas

    DEFF Research Database (Denmark)

    Kantor, M.; Moseev, D.; Salewski, Mirko

    2014-01-01

    The kinetic temperature in complex plasmas is often measured using particle tracking velocimetry. Here, we introduce a criterion which minimizes the probability of faulty tracking of particles with normally distributed random displacements in consecutive frames. Faulty particle tracking results...... in a measurement bias of the deduced velocity distribution function and hence the deduced kinetic temperature. For particles with a normal velocity distribution function, mistracking biases the obtained velocity distribution function towards small velocities at the expense of large velocities, i.e., the inferred...... velocity distribution is more peaked and its tail is less pronounced. The kinetic temperature is therefore systematically underestimated in measurements. We give a prescription to mitigate this type of error....

  1. Boom accomodation effects on plasma and field measurements with RPWI

    Science.gov (United States)

    Cervantes Correa, P.; Eriksson, A. I.; Wahlund, J.-E.; Odelstad, E.; Vaivads, A.; Bergman, J.

    2013-09-01

    While the JUICE spacecraft configuration and main contractor are yet to be decided, it is still possible to investigate general issues on the impact of various boom accomodation alternatives for measurements of plasma and electric fields using the Langmuir probe system of the Radio and Plasma Waves Investigation. These probes can be used as classical Langmuir probes, as electric field probes, or for mutual impedance measurements, and the impact of e.g. varying illumination and wake interference are different for each type of measurement. While there is a nominal JUICE trajectory for the main science mission, we have to do assumptions on the spacecraft pointing, e.g. nadir pointing during flybys of the various moons. The detailed spacecraft layout is not known, but we can arrive at general conclusions on the suitability of various boom accomodations by assuming a cube-like spacecraft with solar panels as rectangular wings. For disturbing structures like wakes and photoelectron clouds we use simple models based on previous simulations. Even though the detailed pointing and spacecraft design will quite certainly deviate from our assumptions, and the model has uncertainties also in other respects, we can still give some general conclusions on boom accomodation alternatives.

  2. Measurement of the dynamo effect in a plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ji, H. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Prager, S.C.; Almagri, A.F.; Sarff, J.S. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Hirano, Y. [Electrotechnical Lab., Tsukuba, Ibaraki (Japan). Plasma Section; Toyama, H. [Univ. of Tokyo (Japan). Dept. of Physics

    1995-11-01

    A series of the detailed experiments has been conducted in three laboratory plasma devices to measure the dynamo electric field along the equilibrium field line (the {alpha} effect) arising from the correlation between the fluctuating flow velocity and magnetic field. The fluctuating flow velocity is obtained from probe measurement of the fluctuating E x B drift and electron diamagnetic drift. The three major findings are (1) the {alpha} effect accounts for the dynamo current generation, even in the time dependence through a ``sawtooth`` cycle; (2) at low collisionality the dynamo is explained primarily by the widely studied pressureless Magnetohydrodynamic (MHD) model, i.e., the fluctuating velocity is dominated by the E x B drift; (3) at high collisionality, a new ``electron diamagnetic dynamo`` is observed, in which the fluctuating velocity is dominated by the diamagnetic drift. In addition, direct measurements of the helicity flux indicate that the dynamo activity transports magnetic helicity from one part of the plasma to another, but the total helicity is roughly conserved, verifying J.B. Taylor`s conjecture.

  3. Conditional Standard Errors of Measurement for Composite Scores Using IRT

    Science.gov (United States)

    Kolen, Michael J.; Wang, Tianyou; Lee, Won-Chan

    2012-01-01

    Composite scores are often formed from test scores on educational achievement test batteries to provide a single index of achievement over two or more content areas or two or more item types on that test. Composite scores are subject to measurement error, and as with scores on individual tests, the amount of error variability typically depends on…

  4. Effect of atmospheric pressure plasma treatment condition on adhesion of ramie fibers to polypropylene for composite

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [College of Material and Textile Engineering, Jiaxing University, Jiaxing 314033 (China); Center for Plasma-Aided Manufacturing, Madison, WI 53706 (United States); School of Human Ecology, University of Wisconsin-Madison, Madison, WI 53706 (United States); Manolache, Sorin [Center for Plasma-Aided Manufacturing, Madison, WI 53706 (United States); US Forest Products Laboratory, Madison, WI 53726 (United States); Qiu, Yiping, E-mail: ypqiu@dhu.edu.cn [College of Textiles, Donghua University, Shanghai 201620 (China); Sarmadi, Majid, E-mail: majidsar@wisc.edu [Center for Plasma-Aided Manufacturing, Madison, WI 53706 (United States); School of Human Ecology, University of Wisconsin-Madison, Madison, WI 53706 (United States); Materials Science Program, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2016-02-28

    Graphical abstract: - Highlights: • The continuous ethanol flow technique can successfully modify ramie fiber surface with an increase in IFSS value up to 50%. • Response surface methodology was applied to design the plasma treatment parameters for ramie fiber modification. • The ethanol flow rate was the most influential treatment parameter in plasma modification process. - Abstract: In order to improve the interfacial adhesion between hydrophilic ramie fibers and hydrophobic polypropylene (PP) matrices, ramie fibers are modified by atmospheric pressure dielectric barrier discharge (DBD) plasma with our continuous ethanol flow technique in helium environment. A central composite design of experiments with different plasma processing parameter combinations (treatment current, treatment time and ethanol flow rate) is applied to find the most influential parameter and to obtain the best modification effect. Field emission scanning electron microscope (SEM) shows the roughened surfaces of ramie fibers from the treated groups due to plasma etching effect. Dynamic contact angle analysis (DCAA) demonstrates that the wettability of the treated fibers drastically decreases. Microbond pullout test shows that the interfacial shear strength (IFSS) between treated ramie fibers and PP matrices increases significantly. Residual gas analysis (RGA) confirms the creation of ethyl groups during plasma treatment. This study shows that our continuous ethanol flow technique is effective in the plasma modification process, during which the ethanol flow rate is the most influential parameter but all parameters have simultaneous influence on plasma modification effect of ramie fibers.

  5. Modification of Composite Material Fillers by Atmospheric Plasma Discharge

    Directory of Open Access Journals (Sweden)

    David Tichy

    2013-01-01

    Full Text Available This work is focused on the observation of the influence of cold atmospheric dielectric barrier discharge (DBD on a modification of textile samples. The main objective of the experiment is to research wettability change of textiles modified by different exposure times and also the observation of the influence of a modification ageing effect. An ambient air was used as a working gas for DBD plasma. The wettability evaluation was carried out by a drop method, in which an imprint of the dropwas observed on the textile surface during various time intervals. An ageing effect of the modification was monitored within an interval of 28 days. Considerable increase of wettability of all modified samples has been proved. A fibre surface analysis was carried out by means of SEM.

  6. Iodine Plasma Species Measurements in a Hall Effect Thruster Plume

    Science.gov (United States)

    2013-04-01

    vary across the plume. Furthermore, ion energy measurements here and historically show non - Maxwellian ion velocity distributions that vary with...related to beam composition or to non -uniformities in the gas flow distribution. Thus, thrust data are not reported...distribution is far from Maxwellian . D. Combined Probe The combined ESA/ExB probe was used to analyze specific populations selected from the ESA data

  7. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

    2016-07-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties.

  8. Simulation of cold atmospheric plasma component composition and particle densities in air

    Science.gov (United States)

    Kirsanov, Gennady; Chirtsov, Alexander; Kudryavtsev, Anatoliy

    2015-11-01

    Recently discharges in air at atmospheric pressure were the subject of numerous studies. Of particular interest are the cold streams of air plasma, which contains large amounts of chemically active species. It is their action can be decisive in the interaction with living tissues. Therefore, in addition to its physical properties, it is important to know the component composition and particle densities. The goal was to develop a numerical model of atmospheric pressure glow microdischarge in air with the definition of the component composition of plasma. To achieve this goal the task was divided into two sub-tasks, in the first simulated microdischarge atmospheric pressure in air using a simplified set of plasma chemical reactions in order to obtain the basic characteristics of the discharge, which are the initial approximations in the problem of the calculation of the densities with detailed plasma chemistry, including 53 spices and over 600 chemical reactions. As a result of the model was created, which can be adapted for calculating the component composition of plasma of various sources. Calculate the density of particles in the glow microdischarges and dynamics of their change in time.

  9. Influence of surrounding gas, composition and pressure on plasma plume dynamics of nanosecond pulsed laser-induced aluminum plasmas

    Directory of Open Access Journals (Sweden)

    Mahmoud S. Dawood

    2015-10-01

    Full Text Available In this article, we present a comprehensive study of the plume dynamics of plasmas generated by laser ablation of an aluminum target. The effect of both ambient gas composition (helium, nitrogen or argon and pressure (from ∼5 × 10−7 Torr up to atmosphere is studied. The time- and space- resolved observation of the plasma plume are performed from spectrally integrated images using an intensified Charge Coupled Device (iCCD camera. The iCCD images show that the ambient gas does not significantly influence the plume as long as the gas pressure is lower than 20 Torr and the time delay below 300 ns. However, for pressures higher than 20 Torr, the effect of the ambient gas becomes important, the shortest plasma plume length being observed when the gas mass species is highest. On the other hand, space- and time- resolved emission spectroscopy of aluminum ions at λ = 281.6 nm are used to determine the Time-Of-Flight (TOF profiles. The effect of the ambient gas on the TOF profiles and therefore on the propagation velocity of Al ions is discussed. A correlation between the plasma plume expansion velocity deduced from the iCCD images and that estimated from the TOF profiles is presented. The observed differences are attributed mainly to the different physical mechanisms governing the two diagnostic techniques.

  10. Composite ion-plasma coatings with nanodisperse reinforced phase: scientific and practical aspects of synthesis

    Science.gov (United States)

    Brzhozovskii, B.; Martynov, V.; Zinina, E.; Brovkova, M.

    2016-02-01

    The article describes the main aspects of the synthesis of composite coatings in the surface layer of figurine-shaped product using low-temperature plasma of combined discharge. The example of cutting tools shows the benefits of using the coatings in extreme conditions that occur in machining of materials by cutting.

  11. Chemical erosion of different carbon composites under ITER-relevant plasma conditions

    NARCIS (Netherlands)

    Westerhout, J.; Borodin, D.; Al, R.S.; Brezinsek, S.; Hoen, Mhjt; Kirschner, A.; Lisgo, S.; van der Meiden, H. J.; Philipps, V.; van de Pol, M.J.; Shumack, A. E.; De Temmerman, G.; Vijvers, W. A. J.; Wright, G. M.; Cardozo, N. J. L.; Rapp, J.; van Rooij, G. J.

    2009-01-01

    We have studied the chemical erosion of different carbon composites in Pilot-PSI at ITER-relevant hydrogen plasma fluxes (similar to 10(24) m(-2) s(-1)) and low electron temperatures (T-e similar to 1 eV). Optical emission spectroscopy on the CH A-X band was used to characterize the chemical

  12. Microstructure of Suspension Plasma Spray and Air Plasma Spray Al2O3-ZrO2 Composite Coatings

    Science.gov (United States)

    Chen, Dianying; Jordan, Eric H.; Gell, Maurice

    2009-09-01

    Al2O3-ZrO2 coatings were deposited by the suspension plasma spray (SPS) molecularly mixed amorphous powder and the conventional air plasma spray (APS) Al2O3-ZrO2 crystalline powder. The amorphous powder was produced by heat treatment of molecularly mixed chemical solution precursors below their crystallization temperatures. Phase composition and microstructure of the as-synthesized and heat-treated SPS and APS coatings were characterized by XRD and SEM. XRD analysis shows that the as-sprayed SPS coating is composed of α-Al2O3 and tetragonal ZrO2 phases, while the as-sprayed APS coating consists of tetragonal ZrO2, α-Al2O3, and γ-Al2O3 phases. Microstructure characterization revealed that the Al2O3 and ZrO2 phase distribution in SPS coatings is much more homogeneous than that of APS coatings.

  13. Composition and species evolution in a laser-induced LuMnO3 plasma

    Science.gov (United States)

    Bator, Matthias; Hu, Yi; Esposito, Martin; Schneider, Christof W.; Lippert, Thomas; Wokaun, Alexander

    2012-09-01

    Pulsed laser deposition is often used to grow multi-elemental thin films from stoichiometric targets. The growth process is influenced by a wide variety of parameters like the target composition, background gases, laser wavelength, laser fluence, or spot size. The changes these parameters induce in the film growth also affect the plasma plume and species formed during laser ablation. For oxide growth O2, and sometimes N2O, is utilized as background gas to achieve the required oxygen composition for the as-grown film. Mass spectrometry combined with time- and space resolved emission spectroscopy is used to investigate the behavior and evolution of plasma species in the plasma plume during the ablation process of LuMnO3 dependent on the background gas.

  14. Composition Estimation in Dividing-Wall Columns Using Temperature Measurements

    OpenAIRE

    Ghadrdan, Maryam; Ivar J. Halvorsen; Skogestad, Sigurd

    2011-01-01

    In this work, we propose a method to estimate the product compositions in a distillation column section based on a combination of a number of temperature measurements from different locations in the column stages.

  15. Measurement of Plutonium Isotopic Composition - MGA

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Duc Ta [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-21

    In this module, we will use the Canberra InSpector-2000 Multichannel Analyzer with a high-purity germanium detector (HPGe) and the MGA isotopic anlysis software to assay a variety of plutonium samples. The module provides an understanding of the MGA method, its attributes and limitations. You will assess the system performance by measuring a range of materials similar to those you may assay in your work. During the final verification exercise, the results from MGA will be combined with the 240Pueff results from neutron coincidence or multiplicity counters so that measurements of the plutonium mass can be compared with the operator-declared (certified) values.

  16. Theory and measurements of emittance preservation in plasma wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Frederico, Joel

    2016-12-01

    In this dissertation, we examine the preservation and measurement of emittance in the plasma wakefield acceleration blowout regime. Plasma wakefield acceleration (PWFA) is a revolutionary approach to accelerating charged particles that has been demonstrated to have the potential for gradients orders of magnitude greater than traditional approaches. The application of PWFA to the design of a linear collider will make new high energy physics research possible, but the design parameters must first be shown to be competitive with traditional methods. Emittance preservation is necessary in the design of a linear collider in order to maximize luminosity. We examine the conditions necessary for circular symmetry in the PWFA blowout regime, and demonstrate that current proposals meet these bounds. We also present an application of beam lamentation which describes the process of beam parameter and emittance matching. We show that the emittance growth saturates as a consequence of energy spread in the beam. The initial beam parameters determine the amount of emittance growth, while the contribution of energy spread is negligible. We also present a model for ion motion in the presence of a beam that is much more dense than the plasma. By combining the model of ion motion and emittance growth, we find the emittance growth due to ion motion is minimal in the case of marginal ion motion. In addition, we present a simulation that validates the ion motion model, which is under further development to examine emittance growth of both marginal and pronounced ion motion. Finally, we present a proof-of-concept of an emittance measurement which may enable the analysis of emittance preservation in future PWFA experiments.

  17. Ptychographic measurements of ultrahigh-intensity laser-plasma interactions

    Science.gov (United States)

    Leblanc, A.; Monchocé, S.; Bourassin-Bouchet, C.; Kahaly, S.; Quéré, F.

    2016-04-01

    The extreme intensities now delivered by femtosecond lasers make it possible to drive and control relativistic motion of charged particles with light, opening a path to compact particle accelerators and coherent X-ray sources. Accurately characterizing the dynamics of ultrahigh-intensity laser-plasma interactions as well as the resulting light and particle emissions is an essential step towards such achievements. This remains a considerable challenge, as the relevant scales typically range from picoseconds to attoseconds in time, and from micrometres to nanometres in space. In these experiments, owing to the extreme prevalent physical conditions, measurements can be performed only at macroscopic distances from the targets, yielding only partial information at these microscopic scales. This letter presents a major advance by applying the concepts of ptychography to such measurements, and thus retrieving microscopic information hardly accessible until now. This paves the way to a general approach for the metrology of extreme laser-plasma interactions on very small spatial and temporal scales.

  18. A study of the formation and dynamics of the Earth's plasma sheet using ion composition data

    Energy Technology Data Exchange (ETDEWEB)

    Lennartsson, O.W.

    1994-04-01

    Over two years of data from the Lockheed Plasma Composition Experiment on the ISEE 1 spacecraft, covering ion energies between 100 eV/e and about 16 keV/e, have been analyzed in an attempt to extract new information about three geophysical issues: (1) solar wind penetration of the Earth's magnetic tail; (2) relationship between plasma sheet and tail lobe ion composition; and (3) possible effects of heavy terrestrial ions on plasma sheet stability.

  19. Behavior of Plasma-Sprayed Hydroxyapatite Coatings onto Carbon/carbon Composites in Simulated Body Fluid

    Science.gov (United States)

    Sui, Jin-Ling; Bo, Wu; Hai, Zhou; Cao, Ning; Li, Mu-Sen

    Two types of hydroxyapatite (HA) coatings onto carbon/carbon composite (C/C composites) substrates, deposited by plasma spraying technique, were immersed in a simulated body fluid (SBF) in order to determine their behavior in conditions similar to the human blood plasma. Calcium ion concentration, pH value, microstructure, and phase compositions were analyzed. Results demonstrated that both the crystal Ca-P phases or the amorphous HA do dissolve slightly, and the dissolution of CaO phases in SBF was evident after 1 day of soaking. The calcium-ion concentration was decreased and the pH value of SBF was increased with the increasing of the immersing time. The precipitation was mainly composed of HA, which was verified by X-ray diffraction (XRD) and electron-probe microanalyzer.

  20. Measuring Permeability of Composite Cryotank Laminants

    Science.gov (United States)

    Oliver, Stanley T.; Selvidge, Shawn; Watwood, Michael C.

    2004-01-01

    This paper describes a test method developed to identify whether certain materials and material systems are suitable candidates for large pressurized reusable cryogenic tanks intended for use in current and future manned launch systems. It provides a quick way to screen numerous candidate materials for permeability under anticipated loading environments consistent with flight conditions, as well as addressing reusability issues. cryogenic tank, where the major design issue was hydrogen permeability. It was successfully used to evaluate samples subjected to biaxial loading while maintaining test temperatures near liquid hydrogen. After each sample was thermally preconditioned, a cyclic pressure load was applied to simulate the in-plane strain. First permeability was measured while a sample was under load. Then the sample was unloaded and allowed to return to ambient temperature. The test was repeated to simulate reusability, in order to evaluate its effects on material permeability.

  1. Plasma methods of obtainment of multifunctional composite materials, dispersion-hardened by nanoparticles

    Science.gov (United States)

    Sizonenko, O. N.; Grigoryev, E. G.; Zaichenko, A. D.; Pristash, N. S.; Torpakov, A. S.; Lipyan, Ye V.; Tregub, V. A.; Zholnin, A. G.; Yudin, A. V.; Kovalenko, A. A.

    2016-04-01

    The new approach in developed plasma methods consists in that dispersionhardening additives (TiC, TiB2 in particular) are not mechanically added to powder mixture as additional component, as in conventional methods, but are instead synthesized during high voltage electric discharges (HVED) in disperse system “hydrocarbon liquid - powder” preservation of ultrafine structure is ensured due to use of spark plasma sintering (SPS) as a consolidation method. HVED in disperse system “hydrocarbon liquid - powder” due to impact of plasma discharge channel, electromagnetic fields, shock waves mechanical impact, hydro flows and volume microcavitation leads to synthesis of nanocarbon, metal powders dispersion and synthesis of micro- (from 10-6 to 10-7 m) and nanosized (from 10-7 to 10-9 m) composite powders of hardening phases. SPS is the passage of pulsed current (superposition of direct and alternating current) through powder with the simultaneous mechanical compressing. The formation of plasma is initiated in gaseous phase that fills gaps between particles. SPS allows targeted control of grain growth rate and thus allows obtainment of multifunctional composite materials dispersion hardened by nanoparticles. Processes of HVED synthesis of micro- and nanosized powders of new compositions from elemental metal powders and their mixtures with the subsequent application of high-speed SPS of obtained powders create conditions for increase of strength (by 10 - 20%), hardness and wear-resistance (by 30 - 60%) of obtained materials.

  2. Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion.

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F; He, Li; She, Fenghua; Orbell, John D; Winther-Jensen, Bjorn; Duke, Mikel C

    2015-07-15

    Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces.

  3. Measurement of effective renal plasma flow in congestive heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Tauxe, W.N.; Dubovsky, E.V.; Mantle, J.A.; Dustan, H.P.; Logic, J.R.

    1981-12-01

    In the management of patients with congestive heart failure (CHF), it is often desirable to have precise knowledge of overall renal function, including the effective renal plasma flow (ERPF). It has long been recognized that ERPF is diminished in CHF. Since glomerular filtration rate is often decreased to a much lesser extent, other noninvasive procedures such as the measurement of creatinine clearances may not be entirely suitable. ERPF determination by the single plasma sampling (SPS) method affords a rapid, simple, noninvasive, and economical technique that is quite accurate and reproducible. A SPS method has been well-tested in patients following renal transplantation plus a wide variety of nephrological disorders. We have been concerned whether the SPS method would be valid in volume expanded patients. In 28 determinations of ERPF in patients with CHF, and in five patients who did not have CHF, we have found the SPS estimation of ERPF to yield results that are not clinically significantly different from those obtained by the detailed compartmental analysis method. The volumes of /sup 131/I-orthoiodohippurate (OIH) distribution were found to be somewhat higher in CHF than in controls, but fractional rate constants were proportionately lower so that intercompartmental flow rates and OIH concentrations were not different from controls. Therefore, the SPS estimation of ERPF is valid in patients with CHF and may be useful in monitoring the renal effects of various hemodynamic and pharmacological interventions.

  4. 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...

  5. The effect of N-stearoylethanolamine on plasma lipid composition in rats with experimental insulin resistance

    Directory of Open Access Journals (Sweden)

    O. V. Onopchenko

    2015-02-01

    Full Text Available A model of insulin resistance (IR, induced by prolonged high fat diet with high content of saturated fats was used to investigate the effect of N-stearoylethanolamine (NSE on the composition of free fatty acids (FFA, plasma lipoprotein spectrum and content of proinflammatory cytokine TNFα in rats. The results of this work showed a rise in the content of monounsaturated fatty acids (18:1 n-9 and a reduction in the level of polyunsaturated fatty acids (20:4 n-6 in plasma of rats with experimental IR. These findings are accompanied by the increased TNFα production and significant changes in plasma lipoprotein profile of rats with the fat overload. Particularly, a decreased high-density lipoprotein (HDL cholesterol level and increased low-density (LDL and very low-density lipoprotein (VLDL cholesterol level were detected. The NSE administration to obese rats with IR restored the content of mono- and polyunsaturated FFA, increased HDL cholesterol content and reduced LDL cholesterol level. In addition, the IR rats treated with NSE showed normalization in the serum TNFα level. Our results showed the restoration of plasma lipid profile under NSE administration in rats with obesity-induced IR. Considering the fact that plasma lipid composition displays the lipid metabolism in general, the NSE actions may play a significant role in the prevention of IR-associated complications.

  6. Pulsed plasma chemical synthesis of SixCyOz composite nanopowder

    Science.gov (United States)

    Kholodnaya, G.; Sazonov, R.; Ponomarev, D.; Remnev, G.

    2017-05-01

    SixCyOz composite nanopowder with an average size of particles about 10-50 nm was produced using the pulsed plasma chemical method. The experiments on the synthesis of nanosized composite were carried out using a TEA-500 pulsed electron accelerator. To produce a composite, SiCl4, O2, and CH4 were used. The major part of experiments was conducted using a plasma chemical reactor (quartz, 140 mm diameter, 6 l volume). The initial reagents were injected into the reactor, then a pulsed electron beam was injected which initiated the chemical reactions whose products were the SixCyOz composite nanopowder. To define the morphology of the particles, the JEOL-II-100 transmission electron microscope (TEM) with an accelerating voltage of 100 kV was used. The substances in the composition of the composite nanopowder were identified using the infrared absorption optical spectrum. To conduct this analysis, the Nicolet 5700 FT-IR spectrometer was used.

  7. RNAi-mediated downregulation of poplar plasma membrane intrinsic proteins (PIPs) changes plasma membrane proteome composition and affects leaf physiology.

    Science.gov (United States)

    Bi, Zhen; Merl-Pham, Juliane; Uehlein, Norbert; Zimmer, Ina; Mühlhans, Stefanie; Aichler, Michaela; Walch, Axel Karl; Kaldenhoff, Ralf; Palme, Klaus; Schnitzler, Jörg-Peter; Block, Katja

    2015-10-14

    Plasma membrane intrinsic proteins (PIPs) are one subfamily of aquaporins that mediate the transmembrane transport of water. To reveal their function in poplar, we generated transgenic poplar plants in which the translation of PIP genes was downregulated by RNA interference investigated these plants with a comprehensive leaf plasma membrane proteome and physiome analysis. First, inhibition of PIP synthesis strongly altered the leaf plasma membrane protein composition. Strikingly, several signaling components and transporters involved in the regulation of stomatal movement were differentially regulated in transgenic poplars. Furthermore, hormonal crosstalk related to abscisic acid, auxin and brassinosteroids was altered, in addition to cell wall biosynthesis/cutinization, the organization of cellular structures and membrane trafficking. A physiological analysis confirmed the proteomic results. The leaves had wider opened stomata and higher net CO2 assimilation and transpiration rates as well as greater mesophyll conductance for CO2 (gm) and leaf hydraulic conductance (Kleaf). Based on these results, we conclude that PIP proteins not only play essential roles in whole leaf water and CO2 flux but have important roles in the regulation of stomatal movement.

  8. Accurate measurement of neodymium isotopic composition using Neptune MC-ICP-MS

    Institute of Scientific and Technical Information of China (English)

    Yueheng YANG; Hongfu ZHANG; Liewen XIE; Fuyuan WU

    2008-01-01

    This paper reports the measurement of the Neodymium isotopic composition by Neptune Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) over the last two years. Although there is concomitant Cerium in the chemical separation process, this has no significant influence on the Neodymium analysis. As for the sample containing small amounts of Samarium (Sm/Nd<0.04), direct calibration for isobaric interference and mass discrimina-tion by the exponential law can be obtained by assuming that Samarium mass discrimination is the same as that of Neodymium. Geological samples after traditional chemi-cal separation were measured by Neptune MC-ICP-MS and Thermal Ionization Mass Spectrometry (TIMS) respectively. The results show that Neptune MC-ICP-MS can measure Neodymium isotopic composition as precisely the TIMS does and is even more effective and less time-consuming than the TIMS Method.

  9. The effect of heating rate and composition on the properties of spark plasma sintered zirconium diboride based composites

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Alexandra; Bo Zhenyu [School of Materials Engineering, Purdue University, West Lafayette, IN 47907 (United States); Hodson, Stephen; Fisher, Timothy [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States); Stanciu, Lia, E-mail: lstanciu@purdue.edu [School of Materials Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We investigated the effect of heating rate on spark plasma sintering of ZrB{sub 2}-SiC-ZrC composites. Black-Right-Pointing-Pointer Adding SiC up to 10 wt.% had a positive effect on densification and strength. Black-Right-Pointing-Pointer Increasing heating rate promoted densification and retarded grain growth when SiC and ZrC content was above 15 wt.%, respectively. Black-Right-Pointing-Pointer Increasing heating rate had a slight negative effect on densification when SiC and ZrC content was at 10%, respectively. - Abstract: Five different compositions of ZrB{sub 2}-SiC-ZrC were prepared and then processed by spark plasma sintering (SPS) to a maximum temperature of 2000 Degree-Sign C, with heating rates of 100 Degree-Sign C/min and 200 Degree-Sign C/min. Grain size, density, Rockwell hardness, flexural strength, and thermal conductivity were evaluated for the processed composites. Adding SiC up to 10 wt.% had a positive effect on densification and strength. Increasing the heating rate promoted densification and less overall grain growth for samples with SiC and ZrC above 15 wt.% each, and had a slight negative effect on densification when these values were at 10%.

  10. Plasma sheet ion composition at various levels of geomagnetic and solar activity

    Science.gov (United States)

    Lennartsson, W.

    1987-08-01

    The data obtained in the earth's plasma sheet by the Plasma Composition Experiment on the ISEE-1 spacecraft are briefly reexamined. The data are shown in the form of statistically averaged bulk parameters for the four major ions H(+), He(2+), He(+), and O(+) to illustrate the apparent mixture of solar and terrestrial ions, a mixture that varies with geomagnetic and other conditions. Some major differences in the statistical properties of different ions, which may have a bearing on the physics of the solar wind-magnetosphere interaction, are highlighted.

  11. Influence of meal composition on postprandial peripheral plasma concentrations of vasoactive peptides in man

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, U; Høst, U; Kelbaek, H

    1996-01-01

    In a randomized cross-over study healthy non-obese male human subjects received standardized isocaloric, isovolumetric meals consisting of either carbohydrate, protein or fat and a non-caloric control meal consisting of an equal volume of water. Peripheral venous plasma concentrations of calcitonin...... that the postprandial peripheral plasma concentrations of CGRP, VIP and PYY are dependent on the caloric meal composition. The VIP, but not the CGRP and PYY concentrations seem to be influenced by gastric distension. The physiological significance of the postprandial alterations in peripheral concentrations...

  12. Plasma kynurenine and related measures in tic disorder patients

    NARCIS (Netherlands)

    Hoekstra, Pieter J.; Anderson, George M.; Troost, Pieter W.; Kallenberg, Cees G. M.; Minderaa, Ruud B.

    2007-01-01

    Objective Increased plasma kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of kynurenine and related molecules in a group of tic disorder patients. Methods Plasma

  13. Plasma kynurenine and related measures in tic disorder patients

    NARCIS (Netherlands)

    Hoekstra, Pieter J.; Anderson, George M.; Troost, Pieter W.; Kallenberg, Cees G. M.; Minderaa, Ruud B.

    2007-01-01

    Objective Increased plasma kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of kynurenine and related molecules in a group of tic disorder patients. Methods Plasma

  14. Plasma kynurenine and related measures in tic disorder patients

    NARCIS (Netherlands)

    Hoekstra, Pieter J.; Anderson, George M.; Troost, Pieter W.; Kallenberg, Cees G. M.; Minderaa, Ruud B.

    Objective Increased plasma kynurenine has been reported in tic disorder patients, and this observation has been suggested to be indicative of immune dysregulation. In the present study, we examined plasma levels of kynurenine and related molecules in a group of tic disorder patients. Methods Plasma

  15. Magnetic Fluctuation Measurement in Sino United Spherical Tokamak Plasma

    Institute of Scientific and Technical Information of China (English)

    LIU Fei; WANG Wen-Hao; HE Ye-Xi; LIU Jun; TAN Yi; XIE Li-Feng; ZENG Long

    2007-01-01

    To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrapeoff layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge.

  16. Composition measurements of binary mixture droplets by rainbow refractometry.

    Science.gov (United States)

    Wilms, J; Weigand, B

    2007-04-10

    So far, refractive index measurements by rainbow refractometry have been used to determine the temperature of single droplets and ensembles of droplets. Rainbow refractometry is, for the first time, to the best of our knowledge, applied to measure composition histories of evaporating, binary mixture droplets. An evaluation method is presented that makes use of Airy theory and the simultaneous size measurement by Mie scattering imaging. The method further includes an empirical correction function for a certain diameter and refractive index range. The measurement uncertainty was investigated by numerical simulations with Lorenz-Mie theory. For the experiments, an optical levitation setup was used allowing for long measurement periods. Temperature measurements of single-component droplets at different temperature levels are shown to demonstrate the accuracy of rainbow refractometry. Measurements of size and composition histories of binary mixture droplets are presented for two different mixtures. Experimental results show good agreement with numerical results using a rapid-mixing model.

  17. Influence of beverage composition on the results of erosive potential measurement by different measurement techniques.

    NARCIS (Netherlands)

    Jager, D.H.; Vieira, A.M.; Ruben, J.L.; Huysmans, M.C.D.N.J.M.

    2008-01-01

    The influence of beverage composition on the measurement of erosive potential is unclear. The aim of this study was to evaluate whether beverage composition influences the measurement of erosive potential and to evaluate the influence of exposure in small and large volumes. Eleven beverages were inc

  18. Influence of beverage composition on the results of erosive potential measurement by different measurement techniques

    NARCIS (Netherlands)

    Jager, D. H. J.; Vieira, A. M.; Ruben, J. L.; Huysmans, M. C. D. N. J. M.

    2008-01-01

    The influence of beverage composition on the measurement of erosive potential is unclear. The aim of this study was to evaluate whether beverage composition influences the measurement of erosive potential and to evaluate the influence of exposure in small and large volumes. Eleven beverages were inc

  19. Investigation of interactions of intense plasma streams with tungsten and carbon fibre composite targets in the PF-1000 facility

    Science.gov (United States)

    Kubkowska, Monika; Skladnik-Sadowska, Elzbieta; Kwiatkowski, Roch; Malinowski, Karol; Kowalska-Strzęciwilk, Ewa; Paduch, Marian; Sadowski, Marek J.; Pisarczyk, Tadeusz; Chodukowski, Tomasz; Kalinowska, Zofia; Zielinska, Ewa; Scholz, Marek

    2014-05-01

    This paper presents the results of research on interactions of pulsed plasma streams, as generated by the PF-1000 facility, with solid targets made of tungsten or carbon fibre composite. The device was equipped with a modified inner electrode with a central tungsten insert of 50 mm in diameter. The PF-1000 experimental chamber was filled with pure deuterium at p0 = 1.47 hPa. At the charging voltage U0 = 24 kV, the maximum current amounted to 1.8 MA in about 5.5 μs after the discharge initiation. The investigated targets were located on the z-axis, at a distance of 9 cm from the inner electrode end. For plasma diagnostics, optical emission spectroscopy, 16-frame laser interferometry and a soft x-ray measuring system of four silicon pin diodes were used. It was observed that plasma streams reached the target about 100 ns after the maximum compression and generated a plasma pillow at the sample surface, as proved from time-resolved optical spectra.

  20. Ablation Resistance of C/C Composites with Atmospheric Plasma-Sprayed W Coating

    Science.gov (United States)

    Zhou, Zhe; Wang, Yuan; Gong, Jieming; Ge, Yicheng; Peng, Ke; Ran, Liping; Yi, Maozhong

    2016-12-01

    To improve the ablation resistance of carbon/carbon (C/C) composites, tungsten (W) coating with thickness of 1.2 mm was applied by atmospheric plasma spraying. The antiablation property of the coated composites was evaluated by oxyacetylene flame ablation experiments. The phase composition of the coating was investigated by a combination of x-ray diffraction analysis and scanning electron microscopy with energy-dispersive x-ray spectroscopy analysis. The ablation resistance of the coated C/C substrates was compared with that of uncoated C/C composites and C/C-CuZr composites after ablation for 30 s. The properties of the coated C/C composites after ablation time of 10, 30, 60, 90, 120, and 180 s were further studied. The results indicated that the mass and linear ablation rates of the W-coated C/C composites were lower than those of uncoated C/C or C/C-CuZr composites after ablation for 30 s. The coating exhibited heat stability after 120 s of ablation, with mass loss and linear ablation rates of 7.39 × 10-3 g/s and 3.50 × 10-3 mm/s, respectively. However, the W coating became ineffective and failed after ablation for 180 s. Three ablation regions could be identified, in which the ablation mechanism of the coating changed from thermochemical to thermophysical erosion to mechanical scouring with increasing ablation time.

  1. An empirical model of ion plasma in the inner magnetosphere derived from CRRES/MICS measurements

    Science.gov (United States)

    Claudepierre, S. G.; Chen, M. W.; Roeder, J. L.; Fennell, J. F.

    2016-12-01

    We describe an empirical model of energetic ion plasma (˜20-400 keV/q) that is constructed from measurements taken by the Magnetospheric Ion Composition Spectrometer (MICS) instrument that flew on the CRRES spacecraft. This is a unique data set in that it provides energetic ion composition in the near-equatorial ring current region during a very active solar maximum. The model database is binned by energy, equatorial pitch angle, L shell, and magnetic local time and provides unidirectional, differential number fluxes of the major ionic constituents of the inner magnetosphere, such as protons (H+), singly charged oxygen (O+), and singly charged helium (He+). The H+ and O+ model fluxes are examined in detail and are consistent with well-known particle transport effects (e.g., adiabatic heating). We also validate these model fluxes against a number of other ion plasma models that are available in the literature. The primary finding is the elevated levels of energetic O+ flux during the CRRES era. We attribute this to a solar cycle effect, related to the enhanced upwelling and oxygen outflow from the ionosphere that occurs during solar maximum, driven by elevated solar extreme ultraviolet radiation. We briefly discuss the implications that the enhanced O+ environment during the CRRES era may have for other results derived from CRRES observations (e.g., statistical wave distributions).

  2. Towards higher stability of resonant absorption measurements in pulsed plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Britun, Nikolay, E-mail: nikolay.britun@umons.ac.be [Chimie des Interactions Plasma Surface (ChIPS), CIRMAP, Université de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Michiels, Matthieu [Materia Nova Research Center, Parc Initialis, B-7000 Mons (Belgium); Snyders, Rony [Chimie des Interactions Plasma Surface (ChIPS), CIRMAP, Université de Mons, 23 Place du Parc, B-7000 Mons (Belgium); Materia Nova Research Center, Parc Initialis, B-7000 Mons (Belgium)

    2015-12-15

    Possible ways to increase the reliability of time-resolved particle density measurements in pulsed gaseous discharges using resonant absorption spectroscopy are proposed. A special synchronization, called “dynamic source triggering,” between a gated detector and two pulsed discharges, one representing the discharge of interest and another being used as a reference source, is developed. An internal digital delay generator in the intensified charge coupled device camera, used at the same time as a detector, is utilized for this purpose. According to the proposed scheme, the light pulses from the reference source follow the gates of detector, passing through the discharge of interest only when necessary. This allows for the utilization of short-pulse plasmas as reference sources, which is critical for time-resolved absorption analysis of strongly emitting pulsed discharges. In addition to dynamic source triggering, the reliability of absorption measurements can be further increased using simultaneous detection of spectra relevant for absorption method, which is also demonstrated in this work. The proposed methods are illustrated by the time-resolved measurements of the metal atom density in a high-power impulse magnetron sputtering (HiPIMS) discharge, using either a hollow cathode lamp or another HiPIMS discharge as a pulsed reference source.

  3. Graphene-reinforced aluminum matrix composites prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    Wen-ming Tian; Song-mei Li; Bo Wang; Xin Chen; Jian-hua Liu; Mei Yu

    2016-01-01

    Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sinter-ing (SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide (Al4C3) is not formed during SPS processing. Further addition of graphene (above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.

  4. Compositional dependence of microstructure and tribological properties of plasma sprayed Fe-based metallic glass coatings

    Institute of Scientific and Technical Information of China (English)

    YANG Qin; LI Ran; LIU ZengQian; SHI MinJie; LUO XueKun; ZHANG Tao

    2012-01-01

    Gas-atomized powders of three Fe-based glass-forming alloys were sprayed on mild steel substrates by atmospheric plasma spaying using the same spaying parameters.Microstructures,thermal stabilities and tribological properties of the sprayed coatings were analyzed.The coating performances showed a strong dependence on the intrinsic characters of the compositions,i,e.,glass-forming ability (GFA) and supercooled liquid region (ΔTx).The coatings tended to exhibit higher amorphous phase fraction for the composition with higher GFA and lower porosity for that with larger ΔTx.All the coatings exhibited superior wear resistance compared with the substrate.Higher wear resistance could be obtained in coatings with higher amorphous phase fraction,i.e.higher GFA of the composition.This study has important implications for composition selecting and optimizing in the fabrication of metallic glass coatings.

  5. Wavefront-sensor-based electron density measurements for laser-plasma accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Plateau, Guillaume; Matlis, Nicholas; Geddes, Cameron; Gonsalves, Anthony; Shiraishi, Satomi; Lin, Chen; van Mourik, Reinier; Leemans, Wim

    2010-02-20

    Characterization of the electron density in laser produced plasmas is presented using direct wavefront analysis of a probe laser beam. The performance of a laser-driven plasma-wakefield accelerator depends on the plasma wavelength, hence on the electron density. Density measurements using a conventional folded-wave interferometer and using a commercial wavefront sensor are compared for different regimes of the laser-plasma accelerator. It is shown that direct wavefront measurements agree with interferometric measurements and, because of the robustness of the compact commercial device, have greater phase sensitivity, straightforward analysis, improving shot-to-shot plasma-density diagnostics.

  6. Feasibility Studies of the Two Filters Method in TJ-II for Electron Temperature Measurements in High Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Baiao, D.; Medina, F.; Ochando, M.; Varandas, C.

    2009-07-01

    The TJ-II plasma soft X-ray emission was studied in order to establish an adequate setup for an electron temperature diagnostic suitable for high density, with spatial and temporal resolutions, based on the two-filters method. The preliminary experimental results reported were obtained with two diagnostics (an X-ray PHA based on a Ge detector and a tomography system) already installed in TJ-II stellarator. These results lead to the conclusion that the two-filters method was a suitable option for an electron temperature diagnostic for high-density plasmas in TJ-II. We present the design and fi rst results obtained with a prototype for the measurement of electron temperature in TJ-II plasmas heated with energetic neutral beams. This system consists in two AXUV20A detectors which measure the soft X-ray plasma emissivity trough beryllium filters of different thickness. From the two-filters technique it is possible to estimate the electron temperature. The analyses carried out allowed concluding which filter thicknesses are most suited for TJ-II plasmas, and enhanced the need of a computer code to simulate signals and plasma compositions. (Author) 7 refs.

  7. Spark plasma sintering of mechanically alloyed in situ copper-niobium carbide composite

    Energy Technology Data Exchange (ETDEWEB)

    Long, B.D. [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Department of Production Systems Engineering, Toyohashi University of Technology (Japan); Othman, R. [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Umemoto, M. [Department of Production Systems Engineering, Toyohashi University of Technology (Japan); Zuhailawati, H., E-mail: zuhaila@eng.usm.m [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2010-09-03

    A Cu-NbC composite with high electrical conductivity and high microhardness was synthesized by mechanical alloying and densified using spark plasma sintering (SPS). Mixtures of Cu-NbC powders corresponding to volume fractions of 1, 5, 15 and 25 vol% NbC were milled in a high energy planetary mill under argon atmosphere for 30 h using ethanol as process control agent. The Cu-NbC as-milled powder was sintered using spark plasma sintering temperatures between 900 and 1000 {sup o}C. X-ray diffraction investigation showed that NbC started to form in the copper matrix during ball milling and the reaction between Nb and C was completed after 10 min of SPS sintering. Electrical conductivity and density of the Cu-15 vol% NbC composite increased with increasing sintering temperature. The results showed the superior properties of SPS-prepared Cu-NbC composite: electrical conductivity is almost 4 times higher and microhardness is 3.5 times higher than with normal sintering. A highest density of 98% and electrical conductivity of 45.6% IACS were obtained in the Cu-1 vol% NbC composite. The highest microhardness of 452.9 Hv was achieved in the Cu-25 vol% NbC composite.

  8. Chemically produced tungsten-praseodymium oxide composite sintered by spark plasma sintering

    Science.gov (United States)

    Ding, Xiao-Yu; Luo, Lai-Ma; Lu, Ze-Long; Luo, Guang-Nan; Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng

    2014-11-01

    Pr2O3 doped W composite were synthesized by a novel wet chemical method and spark plasma sintering. The grain size, relative density and the Vicker hardness HV0.2 of Pr2O3/W samples were 4 μm, 98.3% and 377.2, respectively. The tensile strength values of Pr2O3/W were higher than those of pure W. As the temperature rises from 25 °C to 800 °C, the conductivity of pure W and W-1 wt% Pr2O3 composites decreased with the same trend, was above 150 W/m K.

  9. The determination of micro-arc plasma composition and properties of nanoparticles formed during cathodic plasma electrolysis of 304 stainless steel

    Science.gov (United States)

    Jovović, Jovica; Stojadinović, Stevan; Vasilić, Rastko; Tadić, Nenad; Šišović, Nikola M.

    2017-05-01

    This paper presents the research focused on the determination of micro-arc plasma composition during cathodic plasma electrolysis of AISI304 stainless steel in water solution of sodium hydroxide. The complex line shape of several Fe I spectral lines was observed and, by means of a dedicated fitting procedure based on the spectral line broadening theory and H2O thermal decomposition data, the mole fraction of micro-arc plasma constituents (H2, Fe, O, H, H2O, and OH) was determined. Subsequent characterization of the cathodic plasma electrolysis product formed during the process revealed that it consists of Fe-nanoparticles with median diameter of approximately 60 nm.

  10. Isolation of plasma and nuclear membranes of thymocytes. II. Biochemical composition.

    Science.gov (United States)

    Monneron, A; d'Alayer, J

    1978-04-01

    Thymocyte plasma and nuclear membranes obtained by the procedure described in the accompanying paper were analyzed for their biochemical composition. Plasma membranes were very rich in phospholipid, cholesterol, sialic aicd; they did not contain nucleic acids. In comparison, nuclear membranes had a lower phospholipid to protein ratio and contained much less sialic acid and cholesterol. 50% of the cellular cholesterol and of the membrane-bound sialic acid were found in the plasma membranes, 14% in the nuclear membranes. Live cells were labeled with 131I, and the acid-insoluble radioactivity was followed in the subfractions. A good correlation with the distribution and enrichment of plasma membrane market-enzymes was obtained. Label enrichment was about 50-fold in the two lightest of the three plasma membrane fractions. 60% of the label was contained in the plasma membranes, only 4% in the nuclear membranes. Cross-contamination of these two types of membranes was thus negligible. Sodium dodecyl sulfate-gel electrophoresis revealed three different patterns specific for, respectively, plasma membranes, the microsomal-mitochondrial fraction, and nuclear membranes. Each pattern was characterized by a set of proteins and glycoproteins, among which high molecular weight glycoproteins could be considered as marker-proteins of, respectively, 280,000, 260,000, and 230,000 daltons. 131I-labeling of live cells tagged with a very high specific activity three glycoproteins of mol wt 280,000, 200,000, and 135,000 daltons. Nuclear membranes prepared from labeled isolated nuclei had a set of labeled proteins completely different from plasma membranes.

  11. Open air plasma deposited antimicrobial SiOx/TiOx composite films for biomedical applications

    Directory of Open Access Journals (Sweden)

    Rapp Christin

    2016-09-01

    Full Text Available Open air atmospheric pressure plasma jet (APPJ enhanced chemical vapour deposition process was used to deposit biocompatible SiOx/TiOx composite coatings. The as deposited films are hydrophilic and show visible light induced photocatalytic effect, which is a consequence of the formation of defects in the TiOx structure due to the plasma process. This photocatalytic effect was verified by the demonstration of an antimicrobial effect under visible light on E. coli as well as by degradation of Rhodamine B. The films are non-cytotoxic as shown by the cytocompatibility tests. The films are conductive to cell growth and are stable in DMEM and isopropanol. The structural evaluation using SEM, EDS and XPS shows a dispersion of TiOx phase in a SiOxCyHz matrix. These analyses were used to correlate the structure-property relationship of the composite coating.

  12. Choline treatment affects the liver reticuloendothelial system and plasma fatty acid composition in diabetic rats.

    Science.gov (United States)

    Al-Saeedi, Fatma J; Cheng, Behling

    2013-07-01

    This study investigated effects of choline treatment on hepatic reticuloendothelial and biliary functions and plasma fatty acid composition in diabetic rats. Diabetes was induced by streptozotocin (STZ). Choline was administered to untreated rats and a portion of STZ-treated rats for two sequences of five consecutive days, separated by a 2-day interval. Hepatic functions were studied using (99m) Tc Tin (II) colloid (TIN) and 99 mTc mebrofenin [bromo-iminodiacetic acid (BrIDA)] imaging. The TIN-uptake ratios (organ/whole body) of heart, liver and spleen, and the BrIDA-uptake ratios (organ or tissue/whole body) of liver, biliary tree and abdomen were obtained following imaging studies. Fatty acids were analysed by GC/MS. Choline treatment did not attenuate hyperglycaemic development. Diabetic rats showed (i) a decreased TIN-uptake ratio in liver with co-increased ratios in heart and spleen; choline treatment diminished these changes, (ii) elevated BrIDA-uptake ratios in biliary tree and abdomen but not in liver; choline treatment did not attenuate the elevations and (iii) decreases in plasma palmitoleic acid and oleic acid, reflecting an impaired stearoyl-CoA desaturase function; choline treatment did not affect the diminutions, but caused a decrease in arachidonic acid with a co-increase in linoleic acid. Some rats developed hypoproteinemia (HPO). HPO rats also exhibited decreases in plasma palmitoleic acid and oleic acid. Diabetes caused almost absence of palmitoleic acid in HPO rats. Choline treatment exerted no effect on the plasma fatty acid composition of diabetic HPO rats. Choline treatment affected hepatic reticuloendothelial function and plasma fatty acid composition, but not hepatobiliary function, in diabetic rats. Whether choline treatment is beneficial requires further studies. © 2013 The Authors Clinical Physiology and Functional Imaging © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

  13. Thrust Stand Measurements of a Conical Pulsed Inductive Plasma Thruster

    Science.gov (United States)

    Hallock, Ashley K.; Polzin, Kurt A.; Emsellem, Gregory D.

    2012-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters can su er from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. The Microwave Assisted Discharge Inductive Plasma Accelerator (MAD-IPA)[4], shown in Fig. 1 is a pulsed inductive plasma thruster that is able to operate at lower pulse energies by partially ionizing propellant with an electron cyclotron resonance (ECR) discharge inside a conical inductive coil whose geometry serves to potentially increase propellant and plasma plume containment relative to at coil geometries. The ECR plasma is created with the use of permanent mag- nets arranged to produce a thin resonance region along the inner surface of the coil, restricting plasma formation and, in turn, current sheet formation to areas of high magnetic coupling to the driving coil.

  14. Effect of process parameters on coating composition of cathodic-plasma-electrolysis-treated copper

    Indian Academy of Sciences (India)

    ASIYEH HABIBI; S MOHAMMAD MOUSAVI KHOIE; FARZAD MAHBOUBI; MUSTAFA URGEN

    2017-04-01

    Cathodic plasma electrolysis is a novel technique to form nanostructured layers on metallic surfaces by application of high voltage in a suitable aqueous electrolyte. In the present study, copper is treated by plasma electrolysisin 50 vol% ethanol electrolyte and coatings comprising carbon nanostructure and copper oxide are formed on the copper. The effect of some process parameters such as electrical conductivity, volume and temperature of electrolyte and ratio of anode to cathode surface area on current–voltage behaviour and subsequently coating compositions are investigated at 150V deposition voltage. The composition and morphology of these coatings are characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Different current–voltage behaviours, temperatures of substrate and the contents and energies of radicals and ions around the substrate by changes in the mentioned parameters cause different compositions from 100 vol% copper oxide to different ratios of copper oxide to carbon, the structure changing from amorphous to graphitic structure in carbon and amorphous to cubic morphology in copper oxide on the substrate. Therefore, the understanding of cathodic plasma electrolysiscan be developed.

  15. Measurement of Plasma Density Produced in Dielectric Barrier Discharge for Active Aerodynamic Control with Interferometer

    Institute of Scientific and Technical Information of China (English)

    LI Gang; ZHANG Yi; XU Yan-Ji; LIN Bin; LI Yu-Tong; ZHU Jun-Qiang

    2009-01-01

    We utilize an interferometer to investigate the changes of the refractive index caused by dielectric barrier discharge plasma.The electronic density of the plasma produced is measured and analyzed tentatively.The results show that density of the plasma increases linearly with exciting voltages.

  16. Consolidation of B4C-TaB2 eutectic composites by spark plasma sintering

    Directory of Open Access Journals (Sweden)

    Dmytro Demirskyi

    2015-12-01

    Full Text Available The in situ synthesis/consolidation of B4C-TaB2 eutectic composites by spark plasma sintering (SPS is reported. The microstructure–property relations were determined for composites with the B4C-TaB2 eutectic composition as functions of TaB2 content, and TaB2-TaB2 interlamellar spacing. A clear maximum in fracture toughness was identified (∼4.5 MPa m1/2 for eutectic composites with interlamellar spacing between 0.9 and 1.1 μm. The composites with the hypereutectic composition of 40 mol.% TaB2 obtained by SPS exhibited lower Vickers hardness (25–26 GPa but higher indentation fracture toughness (up to 4.9 MPa m1/2 than eutectic composites with 30–35 mol.% of TaB2.

  17. Electron density measurement in gas discharge plasmas by optical and acoustic methods

    Science.gov (United States)

    Biagioni, A.; Anania, M. P.; Bellaveglia, M.; Chiadroni, E.; Cianchi, A.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Filippi, F.; Mostacci, A.; Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F.; Zigler, A.

    2016-08-01

    Plasma density represents a very important parameter for both laser wakefield and plasma wakefield acceleration, which use a gas-filled capillary plasma source. Several techniques can be used to measure the plasma density within a capillary discharge, which are mainly based on optical diagnostic methods, as for example the well-known spectroscopic method using the Stark broadening effect. In this work, we introduce a preliminary study on an alternative way to detect the plasma density, based on the shock waves produced by gas discharge in a capillary. Firstly, the measurements of the acoustic spectral content relative to the laser-induced plasmas by a solid target allowed us to understand the main properties of the acoustic waves produced during this kind of plasma generation; afterwards, we have extended such acoustic technique to the capillary plasma source in order to calibrate it by comparison with the stark broadening method.

  18. Toothbrush probe for instantaneous measurement of radial profile in tokamak boundary plasma

    Energy Technology Data Exchange (ETDEWEB)

    Uehara, Kazuya; Sengoku, Seio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Amemiya, Hiroshi

    1997-04-01

    A new probe for the instantaneous measurement of radial profiles of the boundary scrape-off layer (SOL) plasma has been developed in a tokamak. Five asymmetric double-probe chips are aligned in parallel to a strong magnetic field in the boundary plasma in a tokamak. This probe is named the `toothbrush probe` and can measure the ion temperature as well as the electron temperature and the plasma density in the SOL plasma within only one tokamak plasma shot. First, only one asymmetric probe is mounted on the divertor plate and it is tried to determine the ion temperature. Then, a manufactured toothbrush probe is mounted in the SOL plasma and the radial plasma profiles are simultaneously obtained. Data on the e-folding length of the plasma profile obtained by the toothbrush probe can determine the information on the transport properties such as the diffusion coefficient and the thermal conductivity of electrons and ions. (author)

  19. Myoglobin plasma level related to muscle mass and fiber composition: a clinical marker of muscle wasting?

    Science.gov (United States)

    Weber, Marc-André; Kinscherf, Ralf; Krakowski-Roosen, Holger; Aulmann, Michael; Renk, Hanna; Künkele, Annette; Edler, Lutz; Kauczor, Hans-Ulrich; Hildebrandt, Wulf

    2007-08-01

    Progressive muscle wasting is a central feature of cancer-related cachexia and has been recognized as a determinant of poor prognosis and quality of life. However, until now, no easily assessable clinical marker exists that allows to predict or to track muscle wasting. The present study evaluated the potential of myoglobin (MG) plasma levels to indicate wasting of large locomotor muscles and, moreover, to reflect the loss of MG-rich fiber types, which are most relevant for daily performance. In 17 cancer-cachectic patients (weight loss 22%) and 27 age- and gender-matched healthy controls, we determined plasma levels of MG and creatine kinase (CK), maximal quadriceps muscle cross-sectional area (CSA) by magnetic resonance imaging, muscle morphology and fiber composition in biopsies from the vastus lateralis muscle, body cell mass (BCM) by impedance technique as well as maximal oxygen uptake (VO(2)max). In cachectic patients, plasma MG, muscle CSA, BCM, and VO(2)max were 30-35% below control levels. MG showed a significant positive correlation to total muscle CSA (r = 0.65, p max as an important functional readout. CK plasma levels appear to be less reliable because prolonged increases are observed in even subclinical myopathies or after exercise. Notably, cancer-related muscle wasting was not associated with increases in plasma MG or CK in this study.

  20. Preparation and Performance of Plasma/Polymer Composite Coatings on Magnesium Alloy

    DEFF Research Database (Denmark)

    Bakhsheshi-Rad, H. R.; Hamzah, E.; Bagheriyan, S.

    2016-01-01

    , globular porosities, and micro-cracks with a thickness of 40-50 μm, while the Al2O3·13%TiO2 coating, as the second layer, presented a unique bimodal microstructure with a thickness of 70-80 μm. The top layer was a hydrophobic polymer, which effectively sealed the porosities of plasma layers. The results......A triplex plasma (NiCoCrAlHfYSi/Al2O3·13%TiO2)/polycaprolactone composite coating was successfully deposited on a Mg-1.2Ca alloy by a combination of atmospheric plasma spraying and dip-coating techniques. The NiCoCrAlHfYSi (MCrAlHYS) coating, as the first layer, contained a large number of voids...... of micro-hardness and bonding strength tests showed that the plasma coating presented excellent hardness (870 HV) and good bonding strength (14.8 MPa). However, the plasma/polymer coatings interface exhibited low bonding strength (8.6 MPa). The polymer coating formed thick layer (100-110 μm...

  1. Comparison of W–TiC composite coatings fabricated by atmospheric plasma spraying and supersonic atmospheric plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Qing Yu, E-mail: qingyuhou@hotmail.com [School of Material Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China); Anhui Key Laboratory of Metal Materials and Processing, Maanshan, Anhui 243002 (China); Luo, Lai Ma [School of Material Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China); Huang, Zhen Yi; Wang, Ping; Ding, Ting Ting [Anhui Key Laboratory of Metal Materials and Processing, Maanshan, Anhui 243002 (China); Wu, Yu Cheng, E-mail: ycwu@hfut.edu.cn [School of Material Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)

    2016-04-15

    Highlights: • W–TiC composite coatings were fabricated by APS and SAPS technologies. • TiC had filling effect on pores and coating/fixing effect on un-melted particles. • Porosity and oxygen content in SAPS coating were lower than that in APS coating. • Thermal conductivity of SAPS coating was higher than that of APS coating. • SAPS coating has better ability to resist to elastic fracture than APS coating does. - Abstract: Tungsten coatings with 1.5 wt.% TiC (W/TiC) were fabricated by atmospheric plasma spraying (APS) and supersonic atmospheric plasma spraying (SAPS) techniques, respectively. The results showed that the typical lamellar structure of plasma spraying and columnar crystalline grains formed in the coatings. Pores located mainly at lamellar gaps in association with oxidation were also observed. TiC phase, distributed at lamellar gaps filled the gaps; and that distributed around un-melted tungsten particles and splashed debris coated the particles or debris that were linked with the TiC at lamellar gaps. The coating and linking of the retained TiC phase prevented the tungsten particles to come off from the coatings. The porosity and the oxygen content of the SAPS-W/TiC were lower than those of the APS-W/TiC coating. The mechanical response of the coatings was strongly dependent on the H/E* ratio (H and E* are the hardness and effective Young’s modulus, respectively). The SAPS-W/TiC coating with a higher H/E* ratio had a better ability to resist to elastic fracture and better fracture toughness as compared with the APS-W/TiC coating with a smaller H/E* ratio. The thermal conductivity of the SAPS-W/TiC coating was greater than that of the APS-W/TiC coating.

  2. Improvement of Strength Characteristics of Aerospace Fiber Reinforced Composite Materials using Atmospheric Pressure Plasma-Graft Polymerization Treatment

    Science.gov (United States)

    Aoi, Tatsuji; Kuroki, Tomoyuki; Tahara, Mitsuru; Okubo, Masaaki

    The atmospheric pressure nonthermal plasma-graft polymerization treatment is applied for the surface modification of the organic fibers in order to enhance the strength of the aerospace structural composite material consisting of the laminated textiles. The influence of the treatment on the composite materials' strength properties is examined. As a result, the plasma-graft polymerization surface treatment is effective for the compression and bend of the composite materials. Because the interfacial bonding between each fiber and matrix resin is strengthened by the treatment, the strengths of the composite materials are increased.

  3. Laser induced fluorescence measurements of axial velocity, velocity shear, and parallel ion temperature profiles during the route to plasma turbulence in a linear magnetized plasma device

    Science.gov (United States)

    Chakraborty Thakur, S.; Adriany, K.; Gosselin, J. J.; McKee, J.; Scime, E. E.; Sears, S. H.; Tynan, G. R.

    2016-11-01

    We report experimental measurements of the axial plasma flow and the parallel ion temperature in a magnetized linear plasma device. We used laser induced fluorescence to measure Doppler resolved ion velocity distribution functions in argon plasma to obtain spatially resolved axial velocities and parallel ion temperatures. We also show changes in the parallel velocity profiles during the transition from resistive drift wave dominated plasma to a state of weak turbulence driven by multiple plasma instabilities.

  4. CO{sub 2} laser diagnostics for measurements of the plasma density profile and plasma density fluctuations on LHD

    Energy Technology Data Exchange (ETDEWEB)

    Vyacheslavov, L.N. [Budker Institute of Nuclear Physics, Novosibirsk (Russian Federation); Tanaka, K.; Kawahata, K. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2001-04-01

    A CO{sub 2} laser based diagnostics complimentary to the existing FIR interferometer is proposed. It combines interferometry for plasma density profile measurement under conditions of large density gradients, and both imaging and scattering techniques for observation of plasma fluctuations. Two-colour interferometer with a slablike probe beam and a single multichannel linear detector array provide observation of plasma density profile and density fluctuations at two locations along the probe beam. Basic characteristics of the diagnostics are considered as well as some effects that include dispersion and are critical for two colour imaging technique. The results of the bench-top experiments with the prototype of the interferometer are presented. (author)

  5. Experimental measurement of ablation effects in plasma armature railguns

    Energy Technology Data Exchange (ETDEWEB)

    Parker, J.V.; Parsons, W.M.

    1986-01-01

    Experimental evidence supporting the importance of ablation in plasma armature railguns is presented. Experiments conducted using the HYVAX and MIDI-2 railguns are described. Several indirect effects of ablation are identified from the experimental results. An improved ablation model of plasma armature dynamics is proposed which incorporates the restrike process.

  6. Ion Temperature-Measurements in Tokamak Plasmas by Rutherford Scattering

    NARCIS (Netherlands)

    Vanblokland, A. A. E.; Barbian, E. P.; Donne, A. J. H.; van der Grift, A. F.; Grimbergen, T. W. M.; Oyevaar, T.; Schüller, F. C.; Tammen, H. F.; Vanderven, H. W.; Vijverberg, T. F.; Dewinter, F. D. A.; Bertschinger, G.; Cosler, A.; Korten, M.

    1992-01-01

    A Rutherford scattering diagnostic has been applied at the TEXTOR tokamak to obtain spatially and temporally resolved information on the temperature of the bulk ions in the plasma. In the experimental setup, a helium atomic beam (30-keV, 12-mA equivalent current) passes vertically through the plasma

  7. Water Plasma Functionalized CNTs/MnO2 Composites for Supercapacitors

    Directory of Open Access Journals (Sweden)

    Shahzad Hussain

    2013-01-01

    Full Text Available A water plasma treatment applied to vertically-aligned multiwall carbon nanotubes (CNTs synthesized by plasma enhanced chemical vapour deposition gives rise to surface functionalization and purification of the CNTs, along with an improvement of their electrochemical properties. Additional increase of their charge storage capability is achieved by anodic deposition of manganese dioxide lining the surface of plasma-treated nanotubes. The morphology (nanoflower, layer, or needle-like structure and oxidation state of manganese oxide depend on the voltage window applied during charge-discharge measurements and are found to be key points for improved efficiency of capacitor devices. MnO2/CNTs nanocomposites exhibit an increase in their specific capacitance from 678 Fg−1, for untreated CNTs, up to 750 Fg−1, for water plasma-treated CNTs.

  8. Measurement of Dijet Angular Distributions and Search for Quark Compositeness

    Science.gov (United States)

    Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alves, G. A.; Amidi, E.; Amos, N.; Anderson, E. W.; Astur, R.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Bartlett, J. F.; Bazizi, K.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahland, T.; Fatyga, M.; Fatyga, M. K.; Featherly, J.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Geld, T. L.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gibbard, B.; Glenn, S.; Gobbi, B.; Goforth, M.; Goldschmidt, A.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Green, J.; Greenlee, H.; Grim, G.; Grinstein, S.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Ting; Hu, Tong; Huehn, T.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jesik, R.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Kehoe, R.; Kelly, M. L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krane, J.; Kirshnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Lan, H.; Lander, R.; Landry, F.; Landsberg, G.; Lauer, B.; Leflat, A.; Li, H.; Li, J.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Q.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Mani, S.; Mao, H. S.; Markeloff, R.; Marshall, T.; Martin, M. I.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miettinen, H.; Mincer, A.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Nicola, M.; Norman, D.; Oesch, L.; Oguri, V.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Pang, M.; Para, A.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stichelbaut, F.; Stoianova, D. A.; Stoker, D.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yanagisawa, C.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1998-01-01

    We have measured the dijet angular distribution in s = 1.8 TeV pp¯ collisions using the D0 detector. Order α3s QCD predictions are in good agreement with the data. At 95% confidence limit the data exclude models of quark compositeness in which the contact interaction scale is below 2 TeV.

  9. Plasma preparation and low-temperature sintering of spherical TiC-Fe composite powder

    Institute of Scientific and Technical Information of China (English)

    Jian-jun Wang; Jun-jie Hao; Zhi-meng Guo; Song Wang

    2015-01-01

    A spherical Fe matrix composite powder containing a high volume fraction (82vol%) of fine TiC reinforcement was produced us-ing a novel process combining in situ synthesis and plasma techniques. The composite powder exhibited good sphericity and a dense struc-ture, and the fine sub-micron TiC particles were homogeneously distributed in theα-Fe matrix. A TiC–Fe cermet was prepared from the as-prepared spherical composite powder using powder metallurgy at a low sintering temperature;the product exhibited a hardness of HRA 88.5 and a flexural strength of 1360 MPa. The grain size of the fine-grained TiC and special surface structure of the spherical powder played the key roles in the fabrication process.

  10. Wear Resistance of Deposited Layer Using Nickel-Based Composite Powders by Plasma-Arc Surfacing

    Institute of Scientific and Technical Information of China (English)

    DONG Li-hong; ZHU Sheng; XU Bin-shi; DU Ze-yu

    2004-01-01

    Nickel-based composite alloy powders were deposited on the surface of Q235 steel by plasma-arc surfacing in this work. Optimal proportions of elements intensifying the composite powders were ascertained by orthogonal design of three factors and three levels and orthogonal polynomial regression analysis , which Cr , Mn , W were 10% ,4% and 7 % respectively.Phase and structure of deposited materials were characterized by optical microscope and X- ray diffraction. Hardness tests and wear resistance tests were carried out to determine the performance of the deposited layers. The results show that the microstructure of deposited layers of composite powders mainly consist of γ-( Ni, Fe ) , γ- Ni, WC, W2 C, Mn31Si12, Cr23 C6,Cr7 C3, Cr, NiB, Ni2B etc. Wear resistance and hardness of the surface increased evidently.

  11. Liquid Phase Plasma Synthesis of Iron Oxide/Carbon Composite as Dielectric Material for Capacitor

    Directory of Open Access Journals (Sweden)

    Heon Lee

    2014-01-01

    Full Text Available Iron oxide/carbon composite was synthesized using a liquid phase plasma process to be used as the electrode of supercapacitor. Spherical iron oxide nanoparticles with the size of 5~10 nm were dispersed uniformly on carbon powder surface. The specific capacitance of the composite increased with increasing quantity of iron oxide precipitate on the carbon powder up to a certain quantity. When the quantity of the iron oxide precipitate exceeds the threshold, however, the specific capacitance was rather reduced by the addition of precipitate. The iron oxide/carbon composite containing an optimum quantity (0.33 atomic % of iron oxide precipitate exhibited the smallest resistance and the largest initial resistance slope.

  12. Tantalum-Tungsten Oxide Thermite Composite Prepared by Sol-Gel Synthesis and Spark Plasma Sintering

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2009-02-13

    Energetic composite powders consisting of sol-gel derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition tested and results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High Pressure Spark Plasma Sintering (HPSPS) technique, on the sol-gel derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The sol-gel derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta - WO{sub 3}) energetic composite was consolidated to a density of 9.17 g.cm{sup -3} or 93% relative density. In addition those parts were consolidated without significant pre-reaction of the constituents, thus the sample retained its stored chemical energy.

  13. Accurate and precise plasma clearance measurement using four 99mTc-DTPA plasma samples over 4 h

    OpenAIRE

    Wanasundara, Surajith N.; Wesolowski, Michal J.; Barnfield, Mark C.; Waller, Michael L.; Murray, Anthony W.; Burniston, Maria T.; Babyn, Paul S.; Wesolowski, Carl A.

    2015-01-01

    Objectives Glomerular filtration rate can be measured as the plasma clearance (CL) of a glomerular filtration rate marker despite body fluid disturbances using numerous, prolonged time samples. We desire a simplified technique without compromised accuracy and precision. Materials and methods We compared CL values derived from two plasma concentration curve area methods – (a) biexponential fitting [CL (E2)] and (b) Tikhonov adaptively regularized gamma variate fitting [CL (Tk-GV)] – for 4 vers...

  14. Composition of fatty acids in plasma and erythrocytes and eicosanoids level in patients with metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Antonyuk Marina V

    2011-05-01

    Full Text Available Abstract Background Disturbances of the fatty acids composition in plasma and red blood cells and eicosanoid synthesis play an important role in the metabolic syndrome (MS formation. Methods The observation group included 61 people with metabolic syndrome (30 patients with MS and normal levels of insulin, 31 people with MS and insulin resistance - IR. The parameters of carbohydrate and lipid metabolism in blood serum were examined. The composition of nonesterified fatty acids (NEFA, fatty acid (FA of red blood cells lipids was analyzed by gas-liquid chromatography. Eicosanoids level in MS patients blood serum was studied by enzyme immunoassay. Results In MS patients in the absence of glucose-insulin homeostasis disturbances and in patients with IR the accumulation of polyunsaturated fatty acids (18:2 n6, 18:3 n3, 22:4 n6 and lower pool of saturated FA (12:0, 14:0, 16: 0, 17:0 in plasma were discovered. A deficit of polyunsaturated FA (18:3 n3, 20:4 n6 with a predominance of on-saturated FA (14:0, 18:0 in erythrocyte membranes was revealed. In MS patients regardless of the carbohydrate metabolism status high levels of leukotriene B4 and 6-keto-prostaglandin-F1α in serum were found. The development of IR in MS patients leads to increased synthesis of thromboxane A2. Conclusion The results revealed a disturbance in nonesterified fatty acids of plasma lipids and red blood cells, eicosanoid synthesis in MS patients. The breach of the plasma and cell membranes fatty acids compositions, synthesis of vasoactive and proinflammatory eicosanoids is an important pathogenetic part of the MS development.

  15. Investigation of microstructure and irradiation behavior of W–Nb/Ti composites prepared by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing-Bo [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Lai-Ma, E-mail: luolaima@126.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Zhao, Mei-Ling [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Xu, Qiu [Research Reactor Institute, Kyoto University, Osaka-Fu 590-0494 (Japan); Zan, Xiang [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China); Wu, Yu-Cheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); National–Local Joint Engineering Research Centre of Nonferrous Metals and Processing Technology, Hefei 230009 (China)

    2016-11-15

    W–Nb/Ti composites were prepared by machine milling and spark plasma sintering. Field–emission scanning electron microscopy, high–resolution transmission electron microscopy, and X-ray diffraction analyses were used to characterize the samples. Thermal desorption spectroscopy (TDS) was used to measure the deuterium retention after only deuterium irradiation. The deuterium retention in W–4wt%Ti–wt1%Nb was lower than that in pure W (D{sub 2}{sup +} flux ∼10{sup 22} ions/(m{sup 2} s), ion energy ∼5 keV), Nb and Ti will improve the deuterium irradiation resistance of tungsten composite. In addition, transgranular and intergranular fractures were observed on the surface of the W–4 wt% Ti–1 wt% Nb composite. A Ti{sub (X)}W{sub (1−X)} solid solution was formed during sintering. The maximum tensile strength (410.53 MPa) was detected in the W–4wt%Ti–1wt%Nb composite at 600 °C.

  16. Diagnosis of energetic ions and ion composition in fusion plasmas by collective Thomson scattering of mm-waves

    DEFF Research Database (Denmark)

    Bindslev, Henrik; Korsholm, Søren Bang; Leipold, Frank;

    2012-01-01

    In fusion plasmas, the dominant heating source will be fusion generated energetic ions slowing down in the plasma. The same ions can also drive waves and instabilities in the plasma. Their distribution in velocity and in space has major impact on plasma dynamics, and plasma dynamics in turn affects...... the energetic ion distributions. The dynamics of energetic ions is thus important to measure in order to understand fusion plasmas, and important to monitor as part of input to plasma control. The collective Thomson scattering of millimeter waves has proven to be a valuable means of diagnosing energetic ion...... distributions in fusion plasmas1,2. A beam of mm-waves with a diameter of 5–10 cm and a power of 150–600 kW is sent through the plasma, and radiation scattered from this probe beam by the microscopic fluctuations in the plasma is detected. These microscopic fluctuations are in part induced by the ion motion...

  17. Protein amino acid composition of plasma membranes affects membrane fluidity and thereby ethanol tolerance in a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae.

    Science.gov (United States)

    Hu, Chun-Keng; Bai, Feng-Wu; An, Li-Jia

    2005-09-01

    A combination of three amino acids including 1.0 g/L isoleucine, 0.5 g/L methionine and 2.0 g/L phenylalanine was found to enhance ethanol tolerance of a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae. When subjected to 20% (V/V) ethanol for 9 h at 30 degrees C, all cells died whereas 57% remained viable for the cells grown in the presence of the three amino acids. Based on the analysis of protein amino acid composition of plasma membranes and the determination of plasma membrane fluidity by measuring fluorescence anisotropy using diphenylhexatriene as a probe, it was found that the significantly increased ethanol tolerance of cells grown with the three amino acids was due to the incorporation of the supplementary amino acids into the plasma membranes, thus resulting in enhanced ability of the plasma membranes to efficiently counteract the fluidizing effect of ethanol when subjected to ethanol stress. This is the first time to report that plasma membrane fluidity can be influenced by protein amino acid composition of plasma membranes.

  18. Development of Polysulfone Hollow Fiber Porous Supports for High Flux Composite Membranes: Air Plasma and Piranha Etching

    OpenAIRE

    Ilya Borisov; Anna Ovcharova; Danila Bakhtin; Stepan Bazhenov; Alexey Volkov; Rustem Ibragimov; Rustem Gallyamov; Galina Bondarenko; Rais Mozhchil; Alexandr Bildyukevich; Vladimir Volkov

    2017-01-01

    For the development of high efficiency porous supports for composite membrane preparation, polysulfone (PSf) hollow fiber membranes (outer diameter 1.57 mm, inner diameter 1.12 mm) were modified by air plasma using the low temperature plasma treatment pilot plant which is easily scalable to industrial level and the Piranha etch (H2O2 + H2SO4). Chemical and plasma modification affected only surface layers and did not cause PSf chemical structure change. The modifications led to surface roughne...

  19. Plasma orexin-A and ghrelin levels in patients with chronic obstructive pulmonary disease: Interaction with nutritional status and body composition.

    Science.gov (United States)

    Akbulut, Gamze; Gezmen-Karadağ, Makbule; Ertaş, Yasemın; Uyar, Banugül Barut; Yassibaş, Emıne; Türközü, Duygu; Celebı, Ferıde; Paşaoğlu, Ozge Tuğçe; Toka, Onur; Yildiran, Hılal; Sanlier, Nevın; Köktürk, Nurdan

    2014-06-01

    Orexin-A and ghrelin are two important polypeptides that stimulate food intake, however, there is a lack of sufficient information concerning their plasma levels in patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the association between plasma orexin-A and ghrelin levels with food consumption and body composition in patients with stable phase COPD. In total, 40 patients (age, 44-80 years; male, 31; female 9) who were in the stable phase of COPD were included in the study. Blood samples for plasma orexin-A and ghrelin analysis were collected after 8-12 h of fasting; certain anthropometric measurements were obtained and a 24-h dietary recall was recorded. The mean plasma orexin-A levels in the male and female patients were 1.3±0.37 and 1.4±0.13 ng/ml, respectively, while the mean plasma ghrelin levels were 25.9±7.31 and 27.3±8.54 ng/ml, respectively. No significant correlation was observed between the body mass index and plasma orexin-A and ghrelin levels or between the plasma ghrelin levels and dietary nutrient intake (P>0.05). The plasma orexin-A levels were demonstrated to be higher in patients with a higher dietary total fibre intake (r=0.303, P=0.022). A similar correlation was observed between plasma orexin-A levels and dietary intake of soluble (r=0.033, P=0.029) and insoluble (r=0.335, P=0.024) fibre, as well as between the daily consumption of calcium and the levels of plasma orexin-A (r=0.065, P=0.046). Therefore, the results of the present study indicated that a positive correlation existed between dietary nutrient intake and plasma orexin-A levels in patients with COPD.

  20. Measurement of Plasma Clotting Using Shear Horizontal Surface Acoustic Wave Sensor

    Science.gov (United States)

    Nagayama, Tatsuya; Kondoh, Jun; Oonishi, Tomoko; Hosokawa, Kazuya

    2013-07-01

    The monitoring of blood coagulation is important during operation. In this study, a shear horizontal surface acoustic wave (SH-SAW) sensor is applied to monitor plasma clotting. An SH-SAW sensor with a metallized surface for mechanical perturbation detection can detect plasma clotting. As plasma clotting is a gel formation reaction, the SH-SAW sensor detects viscoelastic property changes. On the other hand, an SH-SAW sensor with a free surface for electrical perturbation detection detects only the liquid mixing effect. No electrical property changes due to plasma clotting are obtained using this sensor. A planar electrochemical sensor is also used to monitor plasma clotting. In impedance spectral analysis, plasma clotting is measured. However, in the measurement of time responses, no differences between clotting and nonclotting are obtained. Therefore, the SH-SAW sensor is useful for monitoring plasma clotting.

  1. Thrust Stand Measurements of a Conical Inductive Pulsed Plasma Thruster

    Science.gov (United States)

    Hallock, Ashley K.; Polzin, Kurt A.

    2013-01-01

    Inductive Pulsed Plasma Thrusters (iPPT) spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current Propellant is accelerated and expelled at a high exhaust velocity (O(10 -- 100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, inductive pulsed plasma thrusters can suffer from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, inductive pulsed plasma thrusters can suffer from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. A conical coil geometry may offer higher propellant utilization efficiency over that of a at inductive coil, however an increase in propellant utilization may be met with a decrease in axial electromagnetic acceleration, and in turn, a decrease in the total axially-directed kinetic energy imparted to the propellant.

  2. Electronic Structure Measurement of Solid Density Plasmas using X-Ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, G; Glenzer, S H; Rogers, F J; Landen, O L; Blancard, C; Faussurier, G; Renaudin, P; Kuhlbrodt, S; Redmer, R

    2003-08-23

    We present an improved analytical expression for the x-ray dynamic structure factor from a dense plasma which includes the effects of weakly bound electrons. This result can be applied to describe scattering from low to moderate Z plasmas, and it covers the entire range of plasma conditions that can be found in inertial confinement fusion experiments, from ideal to degenerate up to moderately coupled systems. We use our theory to interpret x-ray scattering experiments from solid density carbon plasma and to extract accurate measurements of electron temperature, electron density and charge state. We use our experimental results to validate various equation-of-state models for carbon plasmas.

  3. Plasma interactions determine the composition in pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Laboratory of Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

    2014-09-15

    Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3}, we demonstrate for as grown La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10{sup −3} mbar and ∼2 × 10{sup −1} mbar. In the intermediate pressure range, La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

  4. Effects of Aluminum on ATPase Activity and Lipid Composition of Plasma Membranes from Wheat Roots

    Institute of Scientific and Technical Information of China (English)

    HE Long-fei; LIU You-liang; SHEN Zhen-guo; WANG Ai-qin

    2002-01-01

    The effects of aluminum on ATPase activity and lipid composition of the plasma membranes isolated from root tips of Al-tolerant (Altas 66) or Al-sensitive (Scout 66) cultivar of Triticum aestivum L.was assayed. The results showed that both cultivars had similar changes in H+ -ATPase and Ca2+ -ATPase activities after aluminum treatment. Exposure of both cultivars to 20 and 100 (mol/L aluminum for 5 d significantly decreased the activities of Ca2+ -ATPase of plasma membranes. The activities of H+-ATPasc in plasma membrane increased under 20 μmol/L aluminum and decreased at 100 μmol/L aluminum. With aluminum treatment, the PL content of plasma membrane decreased, but GL content increased. The ratio of PL to GL decreased more distinctly in Scout 66 than that in Altas 66. Treated with 20 and 100 μmol/L aluminum, linolenic acid content and the index of unsaturated fatty acids decreaced greatly in Scout 66, but the index of unsaturated fatty acids in Altas 66 increased slightly.

  5. Neutron stress measurement of W-fiber reinforced Cu composite

    CERN Document Server

    Nishida, M; Ikeuchi, Y; Minakawa, N

    2003-01-01

    Stress measurement methods using neutron and X-ray diffraction were examined by comparing the surface stresses with internal stresses in the continuous tungsten-fiber reinforced copper-matrix composite. Surface stresses were measured by X-ray stress measurement with the sin sup 2 psi method. Furthermore, the sin sup 2 psi method and the most common triaxal measurement method using Hooke's equation were employed for internal stress measurement by neutron diffraction. On the other hand, microstress distributions developed by the difference in the thermal expansion coefficients between these two phases were calculated by FEM. The weighted average strains and stresses were compared with the experimental results. The FEM results agreed with the experimental results qualitatively and confirmed the importance of the triaxial stress analysis in the neutron stress measurement. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  6. Plasma-modified graphene nanoplatelets and multiwalled carbon nanotubes as fillers for advanced rubber composites

    Science.gov (United States)

    Sicinski, M.; Gozdek, T.; Bielinski, D. M.; Szymanowski, H.; Kleczewska, J.; Piatkowska, A.

    2015-07-01

    In modern rubber industry, there still is a room for new fillers, which can improve the mechanical properties of the composites, or introduce a new function to the material. Modern fillers like carbon nanotubes or graphene nanoplatelets (GnP), are increasingly applied in advanced polymer composites technology. However, it might be hard to obtain a well dispersed system for such systems. The polymer matrix often exhibits higher surface free energy (SFE) level with the filler, which can cause problems with polymer-filler interphase adhesion. Filler particles are not wet properly by the polymer, and thus are easier to agglomerate. As a consequence, improvement in the mechanical properties is lower than expected. In this work, multi-walled carbon nanotubes (MWCNT) and GnP surface were modified with low-temperature plasma. Attempts were made to graft some functionalizing species on plasma-activated filler surface. The analysis of virgin and modified fillers’ SFE was carried out. MWCNT and GnP rubber composites were produced, and ultimately, their morphology and mechanical properties were studied.

  7. Numerical simulation of the transient multiphase field during plasma deposition manufacturing composite materials

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A solid/liquid/gas unified model has been developed to investigate the gradient composition formation during the plasma deposition manufacturing(PDM) composite materials process. In this model,an enthalpy porosity model was applied to deal with the melting and solidification of the deposited layer,and a level-set approach was introduced to track the evolution of the free surface of the molten pool and the deposited layer. Moreover,complicated physical phenomena occurring at the liquid/gas interface,including forced convection heat loss,heat emission and plasma heat source,have been incorporated into the governing equations by source terms. In this study,the numerical experiment of nickel base alloy powder deposited on the medium steel substrate by PDM technique was implemented based on the staggered grid and SIMPLEC algorithm. Concentration gradient distribution of the solute material at the composite material interface,fluid flow and temperature distribution in the molten pool and the deposited layer have been investigated in detail.

  8. Numerical simulation of the transient multiphase field during plasma deposition manufacturing composite materials

    Institute of Scientific and Technical Information of China (English)

    KONG FanRong; ZHANG HaiOu; WANG GuiLan

    2009-01-01

    A solid/liquid/gas unified model has been developed to investigate the gradient composition formation during the plasma deposition manufacturing (PDM) composite materials process. In this model, an enthalpy porosity model was applied to deal with the melting end solidification of the deposited layer, and a level-set approach was introduced to track the evolution of the free surface of the molten pool and the deposited layer. Moreover, complicated physical phenomena occurring at the liquid/gas inter-face, including forced convection heat loss, heat emission and plasma heat source, have been incor-porated into the governing equations by source terms. In this study, the numerical experiment of nickel base alloy powder deposited on the medium steel substrate by PDM technique was implemented based on the staggered grid and SlMPLEC algorithm. Concentration gradient distribution of the solute mate-rial at the composite material interface, fluid flow and temperature distribution in the molten pool and the deposited layer have been investigated in detail.

  9. Plasma, magnetic, and electromagnetic measurements at nonmagnetic bodies

    Science.gov (United States)

    Russell, C. T.; Luhmann, J. G.

    The need to explore the magnetospheres of the Earth and the giant planets is widely recognized and is an integral part of our planetary exploration program. The equal need to explore the plasma, magnetic, and electromagnetic environments of the nonmagnetic bodies is not so widely appreciated. The previous, albeit incomplete, magnetic and electric field measurements at Venus, Mars, and comets have proven critical to our understanding of their atmospheres and ionospheres in areas ranging from planetary lightning to solar wind scavenging and accretion. In the cases of Venus and Mars, the ionospheres can provide communication paths over the horizon for low-altitude probes and landers, but we know little about their lower boundaries. The expected varying magnetic fields below these planetary ionospheres penetrates the planetary crusts and can be used to sound the electrical conductivity and the thermal profiles of the interiors. However, we have no knowledge of the levels of such fields, let alone their morphology. Finally, we note that the absence of an atmosphere and an ionosphere does not make an object any less interesting for the purposes of electromagnetic exploration. Even weak remanent magnetism such as that found on the Moon during the Apollo program provides insight into the present and past states of planetary interiors. We have very intriguing data from our space probes during times of both close and distant passages of asteroids that suggest they may have coherent magnetization. If true, this observation will put important constraints on how the asteroids formed and have evolved. Our planetary exploration program must exploit its full range of exploration tools if it is to characterize the bodies of the solar system thoroughly. We should especially take advantage of those techniques that are proven and require low mass, low power, and low telemetry rates to undertake.

  10. The Stability of Weakly Collisional Plasmas with Thermal and Composition Gradients

    CERN Document Server

    Pessah, Martin E; 10.1088/0004-637X/764/1/13

    2013-01-01

    Over the last decade, substantial efforts have been devoted to understanding the stability properties, transport phenomena, and long-term evolution of weakly-collisional, magnetized plasmas which are stratified in temperature. These studies have improved our understanding of the physics governing the intra-cluster medium (ICM), but assumed that ICM is a homogeneous. This, however, might not be a good approximation if heavy elements sediment in the inner region of the galaxy cluster. In this paper, we analyze the stability of a weakly-collisional, magnetized plane-parallel atmosphere which is stratified in both temperature and composition. This allows us to discuss for the first time the dynamics of weakly-collisional environments where heat conduction, momentum transport, and ion-diffusion are anisotropic with respect to the direction of the magnetic field. We show that, depending on the relative signs and magnitudes of the gradients in the temperature and the mean molecular weight, the plasma can be subject ...

  11. Continental crust composition constrained by measurements of crustal Poisson's ratio

    Science.gov (United States)

    Zandt, George; Ammon, Charles J.

    1995-03-01

    DECIPHERING the geological evolution of the Earth's continental crust requires knowledge of its bulk composition and global variability. The main uncertainties are associated with the composition of the lower crust. Seismic measurements probe the elastic properties of the crust at depth, from which composition can be inferred. Of particular note is Poisson's ratio,Σ ; this elastic parameter can be determined uniquely from the ratio of P- to S-wave seismic velocity, and provides a better diagnostic of crustal composition than either P- or S-wave velocity alone1. Previous attempts to measure Σ have been limited by difficulties in obtaining coincident P- and S-wave data sampling the entire crust2. Here we report 76 new estimates of crustal Σ spanning all of the continents except Antarctica. We find that, on average, Σ increases with the age of the crust. Our results strongly support the presence of a mafic lower crust beneath cratons, and suggest either a uniformitarian craton formation process involving delamination of the lower crust during continental collisions, followed by magmatic underplating, or a model in which crust formation processes have changed since the Precambrian era.

  12. Real-time measurement of materials properties at high temperatures by laser produced plasmas

    Science.gov (United States)

    Kim, Yong W.

    1990-01-01

    Determination of elemental composition and thermophysical properties of materials at high temperatures, as visualized in the context of containerless materials processing in a microgravity environment, presents a variety of unusual requirements owing to the thermal hazards and interferences from electromagnetic control fields. In addition, such information is intended for process control applications and thus the measurements must be real time in nature. A new technique is described which was developed for real time, in-situ determination of the elemental composition of molten metallic alloys such as specialty steel. The technique is based on time-resolved spectroscopy of a laser produced plasma (LPP) plume resulting from the interaction of a giant laser pulse with a material target. The sensitivity and precision were demonstrated to be comparable to, or better than, the conventional methods of analysis which are applicable only to post-mortem specimens sampled from a molten metal pool. The LPP technique can be applied widely to other materials composition analysis applications. The LPP technique is extremely information rich and therefore provides opportunities for extracting other physical properties in addition to the materials composition. The case in point is that it is possible to determine thermophysical properties of the target materials at high temperatures by monitoring generation and transport of acoustic pulses as well as a number of other fluid-dynamic processes triggered by the LPP event. By manipulation of the scaling properties of the laser-matter interaction, many different kinds of flow events, ranging from shock waves to surface waves to flow induced instabilities, can be generated in a controllable manner. Time-resolved detection of these events can lead to such thermophysical quantities as volume and shear viscosities, thermal conductivity, specific heat, mass density, and others.

  13. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

    Science.gov (United States)

    Ritts, Andy Charles; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-01-01

    The objective of this study is to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces for composite restoration. Extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated by using a non-thermal atmospheric argon plasma brush for various durations. The molecular changes of the dentin surfaces were analyzed using FTIR/ATR and an increase in carbonyl groups on dentin surfaces was detected with plasma treated dentin. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars as the specimens for tensile test. Student Newman Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment. However, the bonding strength to plasma treated inner dentin did not show any improvement. It was found that plasma treatment of peripheral dentin surface up to 100 s gave an increase in interfacial bonding strength, while a prolong plasma treatment of dentin surfaces, e.g., 5 min treatments, showed a decrease in interfacial bonding strength. PMID:20831586

  14. Fatty acid composition of phospholipids and esterified cholesterol of the blood plasma of rabbit under arginine acute pancreatitis

    Directory of Open Access Journals (Sweden)

    O. O. Hopanenko

    2015-04-01

    Full Text Available The content and fatty acid composition of phospholipids and esterified cholesterol were studied in the blood plasma of rabbits under acute arginine pancreatitis and its correction using linseed oil. It is established that the transport and anti-inflammatory functions of blood plasma deteriorates under acute arginine pancreatitis due to a decrease of the content of polyunsaturated fatty acids in phospholi­pids. The amount of cholesterol esterified with saturated and monounsaturated fatty acids increases in the blood plasma of rabbits. The concentration of phospholipids­ and esterified cholesterol is normali­zed and their fatty acid composition is improved in the lipid composition of the blood plasma of rabbits with acute arginine pancreatitis fed with linseed oil.

  15. Ballistic pendula for measuring the momentum of a laser-produced plasma

    Science.gov (United States)

    Grun, J.; Ripin, B. H.

    1982-12-01

    We describe the use of a ballistic pendulum array to measure the momentum of a laser-produced plasma. An in situ calibration method is described and the pendulum results are compared to measurements made with other diagnostics.

  16. Body composition as measured by in vivo neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cohn, S.H.; Sawitsky, A.; Vartsky, D.; Yasumura, S.; Zanzi, I.; Gartenhaus, W.; Ellis, K.J.

    1979-01-01

    A large scale study is currently underway on the changes in body composition resulting from the cachexia of malignancy. The ultimate objective of the overall project is to assess the changes in body composition associated with hyperalimentation and other modes of nutritional support to cancer patients. The first phase of this study is now in progress. In this phase, a study is being made of a control group of normal patients to provide baseline data against which data from cancer patients can be evaluated. Total body nitrogen and potassium are measured in a group of normal men and women, and are analyzed as a function of age. Additionally, changes in skeletal mass (total body calcium) are also recorded, and body water is measured simultaneously with the use of tritiated water.

  17. Tribological Properties of Aluminium Alloy Composites Reinforced with Multi-Layer Graphene—The Influence of Spark Plasma Texturing Process

    Directory of Open Access Journals (Sweden)

    Marek Kostecki

    2017-08-01

    Full Text Available Self-lubricating composites are designed to obtain materials that reduce energy consumption, improve heat dissipation between moving bodies, and eliminate the need for external lubricants. The use of a solid lubricant in bulk composite material always involves a significant reduction in its mechanical properties, which is usually not an optimal solution. The growing interest in multilayer graphene (MLG, characterised by interesting properties as a component of composites, encouraged the authors to use it as an alternative solid lubricant in aluminium matrix composites instead of graphite. Aluminium alloy 6061 matrix composite reinforced with 2–15 vol % of MLG were synthesised by the spark plasma sintering process (SPS and its modification, spark plasma texturing (SPT, involving deformation of the pre-sintered body in a larger diameter matrix. It was found that the application of the SPT method improves the density and hardness of the composites, resulting in improved tribological properties, particularly in the higher load regime.

  18. Morphology and Phase Compositions of Hydroxyapatite Powder Particles Plasma-sprayed into Water

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Hydroxyapatite powder particles were plasma sprayed into water, their inner structures and phase compositions were studied by using scanning electron microscope(SEM) and X-ray difiractometer. The results show that the molten HA particles have a central hollow morphology and high crystallinity. The hollow morphology was caused by sublimated P2O5 and H2O, which will have an efiect on surface morphology, cohesive and adhesive strength as well as dissolution and degradation of coating. The high crystallinity is attributed to lower cooling speed in water.

  19. The change of NiCrBSi alloys’ phase composition after plasma spraying

    Directory of Open Access Journals (Sweden)

    A. Dudek

    2008-08-01

    Full Text Available Material for investigations was NiCrBSi powder for components’ coatings which improve their corrosion resistance as well as resistance to friction wear and erosion. Plasma spraying method was used to produce a coating with thickness of 300 μm on low-alloy steel which was then remelted with the base material. Using X-ray quality analysis, phase composition was determined for: NiCrBSi powder, obtained coating and the alloyed surface layer. Crystallinity degree was also calculated for NiCrBSi layer sprayed on the base material.

  20. Ion Composition of the Thermal Plasma in the F-Ring Region of Saturn

    Science.gov (United States)

    Ip, W. H.; Tseng, W. L.; Hsu, J. K.; Wei, C. E.; Shen, C. H.

    2016-12-01

    In the final phase of the Cassini mission in 2016-2017, the spacecraft will first move to orbits with periapse outside the F-ring and then to orbits grazing the upper atmosphere of Saturn. These trajectories will provide the unique opportunity to sample the structures and composition of Saturn's ionosphere but also those of the main rings. From an assessment of the neutral gas and plasma environment of the rings, we investigate the formation of molecular ions and nano-grains in the areas to be probed by Cassini during its F-ring and Proximal orbits

  1. Thomson scattering measurement of a shock in laser-produced counter-streaming plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Morita, T.; Kuramitsu, Y.; Moritaka, T. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Sakawa, Y.; Takabe, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan); Tomita, K.; Nakayama, K.; Inoue, K.; Uchino, K. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1, Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Ide, T.; Tsubouchi, K. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishio, K.; Ide, H.; Kuwada, M. [Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan)

    2013-09-15

    We report the first direct measurement of temporally and spatially resolved plasma temperatures at a shock as well as its spatial structure and propagation in laser-produced counter-streaming plasmas. Two shocks are formed in counter-streaming collisionless plasmas early in time, and they propagate opposite directions. This indicates the existence of counter-streaming collisionless flows to keep exciting the shocks, even though the collisional effects increase later in time. The shock images are observed with optical diagnostics, and the upstream and downstream plasma parameters of one of the shocks are measured using Thomson scattering technique.

  2. Research of the Tribological Properties of the Surface on 16Mn Steel by Plasma Nitriding and S-N-C Plasmas Composite Treatment

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-chun; ChEN Rui

    2004-01-01

    Sulfide layer with certain thickness was made on the nitrided surface of 16Mn steel by means of plasma S-C-N composite treatment. Under half lubricated condition, friction coefficient and wear loss of LY12 aluminum alloy were measured in sliding against samples of 16Mn treated by cubrizing and sulphiding respectively; In order to avoid the transfer of aluminum to the steel that lead to the inaccurate measurement of wear loss of carburized samples, Gr15 steel was adopted as counterpart face to measure the wear loss of them. SEM and EDAX were used for the morphological and chemical characterization of the wear surface and longitudinal cross-sections beneath sliding surface of LY12 aluminum alloy cirque and the wear tacks of the carburized samples and sulphided samples. Results show: The surface roughness,wear rate, average friction coefficient and magnitude of friction fluctuations of LY 12 aluminum alloy cirque sliding against sulphided sample were all lower than sliding against carburized sample; Compared with carburized layer, sulfide layer of 16Mn steel can not only efficiently prevent the occurrence of adhesion when sliding against LY12 aluminum alloy, but also greatly lower the wear loss when sliding against Grl 5 steel.

  3. Deposition of titanium nitride and hydroxyapatite-based biocompatible composite by reactive plasma spraying

    Science.gov (United States)

    Roşu, Radu Alexandru; Şerban, Viorel-Aurel; Bucur, Alexandra Ioana; Dragoş, Uţu

    2012-02-01

    Titanium nitride is a bioceramic material successfully used for covering medical implants due to the high hardness meaning good wear resistance. Hydroxyapatite is a bioactive ceramic that contributes to the restoration of bone tissue, which together with titanium nitride may contribute to obtaining a superior composite in terms of mechanical and bone tissue interaction matters. The paper presents the experimental results in obtaining composite layers of titanium nitride and hydroxyapatite by reactive plasma spraying in ambient atmosphere. X-ray diffraction analysis shows that in both cases of powders mixtures used (10% HA + 90% Ti; 25% HA + 75% Ti), hydroxyapatite decomposition occurred; in variant 1 the decomposition is higher compared with the second variant. Microstructure of the deposited layers was investigated using scanning electron microscope, the surfaces presenting a lamellar morphology without defects such as cracks or microcracks. Surface roughness values obtained vary as function of the spraying distance, presenting higher values at lower thermal spraying distances.

  4. Fabrication And Properties Of Silver Based Multiwall Carbon Nanotube Composite Prepared By Spark Plasma Sintering Method

    Directory of Open Access Journals (Sweden)

    Lis M.

    2015-06-01

    Full Text Available The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4. The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.

  5. Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

    Science.gov (United States)

    Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

    2016-01-01

    In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

  6. Processing and characterization of B4C/Cu graded composite as plasma facing component for fusion reactors

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new approach for fabricating B4C/Cu graded composite by rapid self-resistance sintering under ultra-high pressure was presented, by which a near dense B4C/Cu graded composite with a compositional spectrum of 0-100% was successfully fabricated. Plasma relevant performances ofsintered B4C/Cu composite were preliminarily characterized, it is found that its chemical sputtering yield is 70% lower than that of SMF800 nuclear graphite under 2.7 keV D+ irradiation, and almost no damages after 66 shots of in situ plasma discharge in HL-1 Tokamak facility, which indicates B4C/Cu plasma facing component has a good physical and chemical sputtering resistance performance compared with nuclear graphite.

  7. Using Ultrasonic Lamb Waves To Measure Moduli Of Composites

    Science.gov (United States)

    Kautz, Harold E.

    1995-01-01

    Measurements of broad-band ultrasonic Lamb waves in plate specimens of ceramic-matrix/fiber and metal-matrix/fiber composite materials used to determine moduli of elasticity of materials. In one class of potential applications of concept, Lamb-wave responses of specimens measured and analyzed at various stages of thermal and/or mechanical processing to determine effects of processing, without having to dissect specimens. In another class, structural components having shapes supporting propagation of Lamb waves monitored ultrasonically to identify signs of deterioration and impending failure.

  8. Plasma Treatment of Agave Fiber Powder and Its Effect on the Mechanical and Thermal Properties of Composites Based on Polyethylene

    Directory of Open Access Journals (Sweden)

    Florentino Soriano Corral

    2016-01-01

    Full Text Available Composites based on low-density polyethylene (LDPE were prepared with Agave fiber powder (AFP that was coated by plasma polymerization process using ethylene gas. Treated and pristine AFP were analyzed by infrared spectroscopy, scanning electron microscopy, and contact water angle for the assessment of surface properties. The polymer composites were prepared by melt mixing using 0, 5, 10, and 20 wt% of AFP and their mechanical and thermal properties were measured. Dispersion evaluation in water confirmed that the AFP treated changed from hydrophilic to hydrophobic behavior and it was also corroborated with water contact angle tests. The addition of treated and untreated AFP (200 mesh at 20 wt% promotes an increase of Young’s modulus of the composites of up to 60% and 32%, respectively, in relation to the neat matrix. Also, an increase of crystallinity of LDPE was observed by the addition of treated and untreated AFP; however no significant effect on the crystallization temperature was observed in LDPE containing AFP.

  9. Microwave plasma monitoring system for the elemental composition analysis of high temperature process streams

    Energy Technology Data Exchange (ETDEWEB)

    Woskov, Paul P. (Bedford, MA); Cohn, Daniel R. (Chestnuthill, MA); Titus, Charles H. (Newtown Square, PA); Surma, Jeffrey E. (Kennewick, WA)

    1997-01-01

    Microwave-induced plasma for continuous, real time trace element monitoring under harsh and variable conditions. The sensor includes a source of high power microwave energy and a shorted waveguide made of a microwave conductive, high temperature capability refractory material communicating with the source of the microwave energy to generate a plasma. The high power waveguide is constructed to be robust in a hot, hostile environment. It includes an aperture for the passage of gases to be analyzed and a spectrometer is connected to receive light from the plasma. Provision is made for real time in situ calibration. The spectrometer disperses the light, which is then analyzed by a computer. The sensor is capable of making continuous, real time quantitative measurements of desired elements, such as the heavy metals lead and mercury. The invention may be incorporated into a high temperature process device and implemented in situ for example, such as with a DC graphite electrode plasma arc furnace. The invention further provides a system for the elemental analysis of process streams by removing particulate and/or droplet samples therefrom and entraining such samples in the gas flow which passes through the plasma flame. Introduction of and entraining samples in the gas flow may be facilitated by a suction pump, regulating gas flow, gravity or combinations thereof.

  10. Surface composition XPS analysis of a plasma treated polystyrene: Evolution over long storage periods.

    Science.gov (United States)

    Ba, Ousmane M; Marmey, Pascal; Anselme, Karine; Duncan, Anthony C; Ponche, Arnaud

    2016-09-01

    A polystyrene surface (PS) was initially treated by cold nitrogen and oxygen plasma in order to incorporate in particular amine and hydroxyl functions, respectively. The evolution of the chemical nature of the surface was further monitored over a long time period (580 days) by chemical assay, XPS and contact angle measurements. Surface density quantification of primary amine groups was performed using three chemical amine assays: 4-nitrobenzaldehyde (4-NBZ), Sulfo succinimidyl 6-[3'(2 pyridyldithio)-pionamido] hexanoate (Sulfo-LC-SPDP) and iminothiolane (ITL). The results showed amine densities were in the range of 2 per square nanometer (comparable to the results described in the literature) after 5min of nitrogen plasma treatment. Over the time period investigated, chemical assays, XPS and contact angles suggest a drastic significant evolution of the chemical nature of the surface within the first two weeks. Beyond that time period and up to almost two years, nitrogen plasma modified substrates exhibits a slow and continuous oxidation whereas oxygen plasma modifed polystyrene surface is chemically stable after two weeks of storage. The latter appeared to "ease of" showing relatively mild changes within the one year period. Our results suggest that it may be preferable to wait for a chemical "stabilization" period of two weeks before subsequent covalent immobilization of proteins onto the surface. The originality of this work resides in the study of the plasma treated surface chemistry evolution over long periods of storage time (580 days) considerably exceeding those described in the literature.

  11. Helium and deuterium irradiation effects in W-Ta composites produced by pulse plasma compaction

    Science.gov (United States)

    Dias, M.; Catarino, N.; Nunes, D.; Fortunato, E.; Nogueira, I.; Rosinki, M.; Correia, J. B.; Carvalho, P. A.; Alves, E.

    2017-08-01

    Tungsten-tantalum composites have been envisaged for first-wall components of nuclear fusion reactors; however, changes in their microstructure are expected from severe irradiation with helium and hydrogenic plasma species. In this study, composites were produced from ball milled W powder mixed with 10 at.% Ta fibers through consolidation by pulse plasma compaction. Implantation was carried out at room temperature with He+ (30 keV) or D+ (15 keV) or sequentially with He+ and D+ using ion beams with fluences of 5 × 1021 at/m2. Microstructural changes and deuterium retention in the implanted composites were investigated by scanning electron microscopy, coupled with focused ion beam and energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, Rutherford backscattering spectrometry and nuclear reaction analysis. The composite materials consisted of Ta fibers dispersed in a nanostructured W matrix, with Ta2O5 layers at the interfacial regions. The Ta and Ta2O5 surfaces exhibited blisters after He+ implantation and subsequent D+ implantation worsened the blistering behavior of Ta2O5. Swelling was also pronounced in Ta2O5 where large blisters exhibited an internal nanometer-sized fuzz structure. Transmission electron microscopy revealed an extensive presence of dislocations in the metallic phases after the sequential implantation, while a relatively low density of defects was detected in Ta2O5. This behavior may be partially justified by a shielding effect from the blisters and fuzz structure developed progressively during implantation. The tungsten peaks in the X-ray diffractograms were markedly shifted after He+ implantation, and even more so after the sequential implantation, which is in agreement with the increased D retention inferred from nuclear reaction analysis.

  12. Quantitative measurement of nanomechanical properties in composite materials

    Science.gov (United States)

    Zhao, Wei

    In this work, quantitative Atomic force acoustic microscopy (AFAM) was used to measure nanomechanical properties and to determine microstructural morphology in fiber reinforced composites and hard calcified tissue. In carbon fiber reinforced composites, the fiber-matrix interphase is of interest as it affects the primary load-transfer process and thereby bulk mechanical properties of reinforced composites. The study of properties in the interphase region is important for an understanding of the bulk mechanical properties, which have been shown affected by moisture-based environmental degradation. Single point AFAM testing has been used to quantitatively determine elastic properties at the fiber-matrix interphase by taking advantage of the high spatial scanning resolution capable of measuring interphase dimensions. Carbon-fiber epoxy composite samples were degraded in laboratory conditions by exposure to a accelerated hydrothermal degradation environment in deionized water and salt water. Composite degradation has been characterized by the change in the epoxy matrix contact stiffness and the interphase properties. A decrease in matrix stiffness was found to coincide with the environmental exposure and moisture absorption of the samples. Interphase stiffness measurements indicate a constant interphase thickness as a function of environmental exposure. Chemical analysis of the epoxy using FTIR and Raman spectroscopy indicate hydrolysis of the C-O-C and Epoxide bonds which contribute to the decrease in epoxy mechanical properties. Accelerated degradation by salt water and deionized water both resulted in degradation of the epoxy, though the presence of sodium chloride showed less degradation. From SEM, debonding of the fiber-matrix interface was observed to be more severe when exposed to a salt water environment. In performing quantitative AFAM measurements, the effects of tip shape on the contact mechanics at the epoxy interface were found to influence the reported

  13. Edge plasma pressure measurements using a mechanical force sensor on the tokamak ISTTOK

    Energy Technology Data Exchange (ETDEWEB)

    Lunt, T [Humboldt-Universitaet zu Berlin, Newtonstrasse 15, 12489, Berlin (Germany); Silva, C [Associaco Euratom/IST, Centro de Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Fernandes, H [Associaco Euratom/IST, Centro de Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Hidalgo, C [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Pedrosa, M A [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Duarte, P [Associaco Euratom/IST, Centro de Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Figueiredo, H [Associaco Euratom/IST, Centro de Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Pereira, T [Associaco Euratom/IST, Centro de Fusao Nuclear, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal)

    2007-11-15

    In the present paper we report on a novel mechanical probe, which is able to measure the plasma pressure directly. The probe consists of two pendulums whose heads are exposed to the tokamak edge plasma, while the deflection is measured very sensitively outside the plasma by means of semi-conductor strain gauges. The plasma pressure was successfully measured in the ISTTOK edge plasma, its value being in good agreement with that derived from the electrical probe data (p{sub p} = 1-10 Pa). Furthermore, we discuss the possibility of determining the ion temperature T{sub i} = p{sub p}/n - T{sub e} by combining the pressure measurement with those of n and T{sub e} from the electrical probes. Although the derived ion temperatures-besides that in the region close to the limiter-were reasonable, its uncertainty is still very large.

  14. IN SITU PLASMA MEASUREMENTS OF FRAGMENTED COMET 73P SCHWASSMANN–WACHMANN 3

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, J. A.; Lepri, S. T.; Combi, M.; Zurbuchen, T. H. [University of Michigan, Ann Arbor, MI 48109 (United States); Rubin, M., E-mail: jagi@umich.edu [Universität Bern, Bern (Switzerland)

    2015-12-10

    The interiors of comets contain some of the most pristine material in the solar system. Comet 73P/Schwassmann–Wachmann 3, discovered in 1930, is a Jupiter-family comet with a 5.34-year period. This comet split into 5 fragments in 1995 and disintegrated into nearly 70 major pieces in 2006. In 2006 May and June, recently ionized cometary particles originating from fragments including and surrounding some of these major objects were collected with the ACE/SWICS and Wind/STICS sensors. Due to a combination of the instrument characteristics and the close proximity of the fragments passing between those spacecraft and the Sun, unique measurements regarding the charge state composition and the elemental abundances of both cometary and heliospheric plasma were made during that time. The cometary material released from some of these fragments can be identified by the concentrations of water-group pickup ions having a mass-per-charge ratio of 16–18 amu e{sup −1}, indicating that while these fragments are small, they are still actively sublimating. We present an analysis of cometary composition, spatial distribution, and heliospheric interactions, with a focus on helium, C{sup +}/O{sup +}, and water-group ions.

  15. Preliminary Results of Plasma Flow Measurements in a 2 KW Segmented Hall Thruster

    Energy Technology Data Exchange (ETDEWEB)

    Y. Raitses; D. Staack; A. Dunaevsky; L. Dorf; N.J. Fisch

    2003-03-01

    A 2-kW Hall thruster was developed, built, and operated in an upgraded vacuum facility. The thruster performance and parameters of the plasma flow were measured by new diagnostics for plume measurements and plasma measurements inside the thruster channel. The thruster demonstrated efficient operation in terms of propellant and current utilization efficiencies in the input power range of 0.5-3.5 kW. Preliminary measurements of the ion energy spectra from the thruster axis region and the distribution of plasma parameters in the vicinity of the thruster exit are reported.

  16. Langmuir probe Diagnostic for local parameter measurement in Magnetized Plasma using LabVIEW

    Directory of Open Access Journals (Sweden)

    Bijal Vara

    2014-03-01

    Full Text Available In recent years, plasma technology is used by Semiconductor, thin film industries for deposit layers, etching process and surface modification. So it is necessary to understanding internal plasma parameter. Langmuir probe is one of the simplest techniques which is used to measure wide range of plasma parameter like plasma potential, floating potential, electron temperature, electron energy distribution function (EEDF etc. Langmuir current voltage characteristic is obtained by varying bias voltage of the probe. LabVIEW is most powerful Microsoft window compatible software which is used to immediate data acquisition and analysis. In this paper describes analysis of Langmuir data using LabVIEW software which automatically measure I-V Plasma probe Characteristics and obtain EEDF of plasma.

  17. Plasma Density Measurements in Cable Gun Experiments with a Sensitive He-Ne Interferometer

    Institute of Scientific and Technical Information of China (English)

    CHEN Lin; HE An; JIANG Wei; XU Min; WU Shoudong; LI Ye

    2007-01-01

    A time-resolved sensitive He-Ne laser interferometer without complicated active stabilization was built up and applied to low-density plasma measurements. A precision of about 0.2° in phase measurements was achieved with a minimum line-integrated plasma density as low as 8.3×l013 cm-2. With this interferometer, the characteristics of the plasma generated by a cable plasma gun was investigated systematically. The reproducibility, spatial and temporal distributions and the averaged injection velocity of the plasma are presented. In addition, the interaction of the plasma flow with a conductor was studied by placing a metal plate in the downstream of the cable gun.

  18. Simultaneous streak and frame interferometry for electron density measurements of laser produced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Quevedo, H. J., E-mail: hjquevedo@utexas.edu; McCormick, M.; Wisher, M.; Bengtson, Roger D.; Ditmire, T. [Center for High Energy Density Science, Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

    2016-01-15

    A system of two collinear probe beams with different wavelengths and pulse durations was used to capture simultaneously snapshot interferograms and streaked interferograms of laser produced plasmas. The snapshots measured the two dimensional, path-integrated, electron density on a charge-coupled device while the radial temporal evolution of a one dimensional plasma slice was recorded by a streak camera. This dual-probe combination allowed us to select plasmas that were uniform and axisymmetric along the laser direction suitable for retrieving the continuous evolution of the radial electron density of homogeneous plasmas. Demonstration of this double probe system was done by measuring rapidly evolving plasmas on time scales less than 1 ns produced by the interaction of femtosecond, high intensity, laser pulses with argon gas clusters. Experiments aimed at studying homogeneous plasmas from high intensity laser-gas or laser-cluster interaction could benefit from the use of this probing scheme.

  19. Simultaneous streak and frame interferometry for electron density measurements of laser produced plasmas

    Science.gov (United States)

    Quevedo, H. J.; McCormick, M.; Wisher, M.; Bengtson, Roger D.; Ditmire, T.

    2016-01-01

    A system of two collinear probe beams with different wavelengths and pulse durations was used to capture simultaneously snapshot interferograms and streaked interferograms of laser produced plasmas. The snapshots measured the two dimensional, path-integrated, electron density on a charge-coupled device while the radial temporal evolution of a one dimensional plasma slice was recorded by a streak camera. This dual-probe combination allowed us to select plasmas that were uniform and axisymmetric along the laser direction suitable for retrieving the continuous evolution of the radial electron density of homogeneous plasmas. Demonstration of this double probe system was done by measuring rapidly evolving plasmas on time scales less than 1 ns produced by the interaction of femtosecond, high intensity, laser pulses with argon gas clusters. Experiments aimed at studying homogeneous plasmas from high intensity laser-gas or laser-cluster interaction could benefit from the use of this probing scheme.

  20. Cotton fabric with plasma pretreatment and ZnO/Carboxymethyl chitosan composite finishing for durable UV resistance and antibacterial property.

    Science.gov (United States)

    Wang, Chunxia; Lv, Jingchun; Ren, Yu; Zhou, Qingqing; Chen, Jiayi; Zhi, Tian; Lu, Zhenqian; Gao, Dawei; Ma, Zhipeng; Jin, Limin

    2016-03-15

    ZnO/carboxymethyl chitosan (ZnO/CMCS) composite was prepared and confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Ultraviolet-visible (UV-vis) spectroscopy, Scanning electron microscope (SEM), Transmission electron microscope (TEM). The combination of plasma pretreatment and ZnO/CMCS composite finishing was applied to provide durable UV resistance and antibacterial activity for cotton fabric. Cotton fabric was pretreated by cold oxygen plasma and the ZnO/CMCS composite finishing was carried out by pad-dry-cure. Cotton fabric was characterized by SEM, FTIR, UV resistance, antibacterial activity and Thermogravimetry (TG). SEM and FTIR analysis demonstrated the presence of ZnO/CMCS composite on cotton fabric and the increasing loading efficiency of ZnO/CMCS composite owing to plasma treatment. UV resistance and antibacterial activity of the finished cotton fabric were greatly improved, which increased with the increasing concentration of ZnO/CMCS composite. TG analysis indicated that the combined finishing of cotton fabric with plasma pretreatment and ZnO/CMCS composite could improve its thermal property. The finished cotton fabric exhibited an excellent laundering durability in UV resistance and antibacterial activity.

  1. The relationship between HbA(1c) and fasting plasma glucose in patients with increased plasma liver enzyme measurements

    DEFF Research Database (Denmark)

    Christiansen, R; Rasmussen, L Melholt; Nybo, H;

    2012-01-01

    levels of increased liver enzyme concentrations. Methods:  Data from 10 065 patients with simultaneous measurement of HbA(1c) , venous fasting plasma glucose, alanine aminotransferase and γ-glutamyl transferase were extracted from our laboratory database. Correlations were investigated in four patient...

  2. Space Plasma Studies by In-Situ and Remote Measurements

    Science.gov (United States)

    2007-11-02

    Awarded by Lenin Prize (highest in USSR). 1962 Plasma experiments aboard KOSMOS 2, evidence of the lack of charged particles thermodynamic equilibrium...ionosphere of Venus. 1970- 1979 Ionospheric experiments aboard COSMOS 378, INTERCOSMOS 8,10,12,14,18,19 and KOSMOS 900. 1970- 1981 Series of in

  3. Simultaneous measurement of arginine vasopressin and oxytocin in plasma and neurohypophysis by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Landgraf, R. (Deutsche Hochschule fuer Koerperkultur, Leipzig (German Democratic Republic). Forschungsinstitut Koerperkultur und Sport)

    1981-12-01

    Arginine vasopressin (AVP) and oxytocin (OXT) were measured simultaneously in the same sample by specific and sensitive radioimmunoassays (RIAs). The antibodies used did not cross-react to a variety of analogs and related peptides. The extraction procedure using Vycor glass powder resulted in mean recoveries of 84.4% (AVP) and 64.6% (OXT). In both assays, the sensitivity was 1 to 2 pg/ml plasma. A preincubation procedure that depresses plasma levels of both AVP and OXT selectively, provided specific blank values for a given plasma sample. To confirm the validity of the RIAs, dehydration experiments were performed. In rats, the basal levels of plasma AVP and OXT (means: 2,63 pg/ml and 6.80 pg/ml, respectively) are increased significantly after 24 h, 48 h and 72 h of water deprivation. Relationships are presented between both neurohormones in the plasma and neurohypophyses of control and dehydrated animals. As shown in cows, a significant correlation exists between plasma AVP and plasma osmolality but not between plasma OXT and osmolality or plasma AVP and OXT. Basal levels as well as physiological changes in plasma and neurohypophyseal AVP and OXT can be measured by the RIAs described.

  4. Feasibility of measuring density and temperature of laser produced plasmas using spectroscopic techniques.

    Energy Technology Data Exchange (ETDEWEB)

    Edens, Aaron D.

    2008-09-01

    A wide variety of experiments on the Z-Beamlet laser involve the creation of laser produced plasmas. Having a direct measurement of the density and temperature of these plasma would an extremely useful tool, as understanding how these quantities evolve in space and time gives insight into the causes of changes in other physical processes, such as x-ray generation and opacity. We propose to investigate the possibility of diagnosing the density and temperature of laser-produced plasma using temporally and spatially resolved spectroscopic techniques that are similar to ones that have been successfully fielded on other systems. Various researchers have measured the density and temperature of laboratory plasmas by looking at the width and intensity ratio of various characteristic lines in gases such as nitrogen and hydrogen, as well as in plasmas produced off of solid targets such as zinc. The plasma conditions produce two major measurable effects on the characteristic spectral lines of that plasma. The 1st is the Stark broadening of an individual line, which depends on the electron density of the plasma, with higher densities leading to broader lines. The second effect is a change in the ratio of various lines in the plasma corresponding to different ionization states. By looking at the ratio of these lines, we can gain some understanding of the plasma ionization state and consequently its temperature (and ion density when coupled with the broadening measurement). The hotter a plasma is, the higher greater the intensity of lines corresponding to higher ionization states. We would like to investigate fielding a system on the Z-Beamlet laser chamber to spectroscopically study laser produced plasmas from different material targets.

  5. A fibre based triature interferometer for measuring rapidly evolving, ablatively driven plasma densities

    Science.gov (United States)

    Macdonald, J.; Bland, S. N.; Threadgold, J.

    2015-08-01

    We report on the first use of a fibre interferometer incorporating triature analysis for measuring rapidly evolving plasma densities of ne ˜ 1013/cm3 and above, such as those produced by simple coaxial plasma guns. The resultant system is extremely portable, easy to field in experiments, relatively cheap to produce, and—with the exception of a small open area in which the plasma is sampled—safe in operation as all laser light is enclosed.

  6. Platelets confound the measurement of extracellular miRNA in archived plasma

    OpenAIRE

    Mitchell, Adam J.; Gray, Warren D; Hayek, Salim S.; Yi-An Ko; Sheena Thomas; Kim Rooney; Mosaab Awad; John D. Roback; Arshed Quyyumi; Searles, Charles D.

    2016-01-01

    Extracellular miRNAs are detectable in biofluids and represent a novel class of disease biomarker. Although many studies have utilized archived plasma for miRNA biomarker discovery, the effects of processing and storage have not been rigorously studied. Previous reports have suggested plasma samples are commonly contaminated by platelets, significantly confounding the measurement of extracellular miRNA, which was thought to be easily addressed by additional post-thaw plasma processing. In a c...

  7. Plasma-cavity ringdown spectroscopy for analytical measurement: Progress and prospectives

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sida; Liu, Wei [Research Center of Analytical Instrumentation, Analytical and Testing Center, College of Chemistry, Sichuan University, Chengdu (China); Zhang, Xiaohe [College of Water Resources and Hydropower, Sichuan University, Chengdu (China); Duan, Yixiang, E-mail: yduan@scu.edu.cn [Research Center of Analytical Instrumentation, Analytical and Testing Center, College of Chemistry, Sichuan University, Chengdu (China)

    2013-07-01

    Plasma-cavity ringdown spectroscopy is a powerful absorption technique for analytical measurement. It combines the inherent advantages of high sensitivity, absolute measurement, and relative insensitivity to light source intensity fluctuations of the cavity ringdown technique with use of plasma as an atomization/ionization source. In this review, we briefly describe the background and principles of plasma-cavity ringdown spectroscopy(CRDS) technology, the instrumental components, and various applications. The significant developments of the plasma sources, lasers, and cavity optics are illustrated. Analytical applications of plasma-CRDS for elemental detection and isotopic measurement in atomic spectrometry are outlined in this review. Plasma-CRDS is shown to have a promising future for various analytical applications, while some further efforts are still needed in fields such as cavity design, plasma source design, instrumental improvement and integration, as well as potential applications in radical and molecular measurements. - Highlights: • Plasma-based cavity ringdown spectroscopy • High sensitivity and high resolution • Elemental and isotopic measurements.

  8. Characterisation of a micro-plasma device sensor using electrical measurements and emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mariotti, D

    2002-04-01

    This thesis reports on research undertaken on the characterisation of a micro-plasma device to be used for gas analysis by mean of plasma emission spectroscopy. The work covers aspects related to the micro-plasma electrical and optical emission parameters, and their importance for the utilisation of the micro-plasma device in gas analysis. Experimental results have been used to analyse the fundamental micro-plasma processes and to develop a model, which could provide additional information. This dissertation contains a general literature review of topics related to plasma physics, plasma emission spectroscopy, gas analysis (chemical analysis and artificial olfaction) and other micro-plasma applications. Experimental work focuses on two main areas: electrical measurements and emission measurements. Firstly, electrical measurements are taken and interpretations are given. Where necessary, new theoretical treatments are suggested in order to describe better the physical phenomena. Plasma emission has been considered under different working conditions. This allowed the characterisation of the micro-plasma emission and also a better understanding of the micro-plasma processes. On the basis of the experimental data obtained and other assumptions a model has been developed. A computer simulation based on this model provided additional useful information on the micro- plasma behaviour. The first fundamental implication of this new research is the peculiar behaviour of the micro-plasma. This micro-plasma exhibited deviations from Paschen law and strong dependency on cathode material, which contributed to the formation of a low current stable regime. These results have been followed by physical interpretations and theoretical descriptions. The second implication is the establishment of the boundaries and of the influencing parameters for plasma emission spectroscopy as an analytical tool in this particular micro-plasma. From the applied perspective this study has shown that

  9. Potassium Stable Isotopic Compositions Measured by High-Resolution MC-ICP-MS

    Science.gov (United States)

    Morgan, Leah E.; Lloyd, Nicholas S.; Ellam, Robert M.; Simon, Justin I.

    2012-01-01

    Potassium isotopic (K-41/K-39) compositions are notoriously difficult to measure. TIMS measurements are hindered by variable fractionation patterns throughout individual runs and too few isotopes to apply an internal spike method for instrumental mass fractionation corrections. Internal fractionation corrections via the K-40/K-39 ratio can provide precise values but assume identical K-40/K-39 ratios (e.g. 0.05% (1sigma) in [1]); this is appropriate in some cases (e.g. identifying excess K-41) but not others (e.g., determining mass fractionation effects and metrologically traceable isotopic abundances). SIMS analyses have yielded measurements with 0.25% precisions (1sigma) [2]. ICP-MS analyses are significantly affected by interferences from molecular species such as Ar-38H(+) and Ar-40H(+) and instrument mass bias. Single collector ICP-MS instruments in "cold plasma" mode have yielded uncertainties as low as 2% (1sigma, e.g. [3]). Although these precisions may be acceptable for some concentration determinations, they do not resolve isotopic variation in terrestrial materials. Here we present data from a series of measurements made on the Thermo Scientific NEPTUNE Plus multi-collector ICP-MS that demonstrate the ability to make K-41/K-39 ratio measurements with 0.07% precisions (1sigma). These data, collected on NIST K standards, indicate the potential for MC-ICP-MS measurements to look for K isotopic variations at the sub-permil level. The NEPTUNE Plus can sufficiently resolve 39K and 41K from the interfering 38ArH+ and 40ArH+ peaks in wet cold plasma and high-resolution mode. Measurements were made on small but flat, interference-free, plateaus (ca. 50 ppm by mass width for K-41). Although ICP-MS does not yield accurate K-41/K-39 values due to significant instrumental mass fractionation (ca. 6%), this bias can be sufficiently stable over the time required for several measurements so that relative K-41/K-39 values can be precisely determined via sample

  10. Anorexia nervosa and nutritional assessment: contribution of body composition measurements.

    Science.gov (United States)

    Mattar, Lama; Godart, Nathalie; Melchior, Jean Claude; Pichard, Claude

    2011-06-01

    The psychiatric condition of patients suffering from anorexia nervosa (AN) is affected by their nutritional status. An optimal assessment of the nutritional status of patients is fundamental in understanding the relationship between malnutrition and the psychological symptoms. The present review evaluates some of the available methods for measuring body composition in patients with AN. We searched literature in Medline using several key terms relevant to the present review in order to identify papers. Only articles in English or French were reviewed. A brief description is provided for each body composition technique, with its applicability in AN as well as its limitation. All methods of measuring body composition are not yet validated and/or feasible in patients with AN. The present review article proposes a practical approach for selecting the most appropriate methods depending on the setting, (i.e. clinical v. research) and the goal of the assessment (initial v. follow-up) in order to have a more personalised treatment for patients suffering from AN.

  11. Nanoclay/Polymer Composite Powders for Use in Laser Sintering Applications: Effects of Nanoclay Plasma Treatment

    Science.gov (United States)

    Almansoori, Alaa; Majewski, Candice; Rodenburg, Cornelia

    2017-06-01

    Plasma-etched nanoclay-reinforced Polyamide 12 (PA12) powder is prepared with its intended use in selective laser sintering (LS) applications. To replicate the LS process we present a downward heat sintering (DHS) process, carried out in a hot press, to fabricate tensile test specimens from the composite powders. The DHS parameters are optimized through hot stage microscopy, which reveal that the etched clay (EC)-based PA12 (EC/PA12) nanocomposite powder melts at a temperature 2°C higher than that of neat PA12, and 1-3°C lower than that of the nonetched clay-based nanocompsite (NEC/PA12 composite). We show that these temperature differences are critical to successful LS. The distribution of EC and NEC onto PA12 is investigated by scanning electron microscopy (SEM). SEM images show clearly that the plasma treatment prevents the micron-scale aggregation of the nanoclay, resulting in an improved elastic modulus of EC/PA12 when compared with neat PA12 and NEC/PA12. Moreover, the reduction in elongation at break for EC/PA12 is less pronounced than for NEC/PA12.

  12. Selective control of reformed composition of n-heptane via plasma chemistry

    KAUST Repository

    Manoj Kumar Reddy, P.

    2016-08-23

    This paper presents experimental results for reforming n-heptane in a temperature-controlled dielectric barrier discharge reactor to show detailed chemical composition in the products and to propose a potential method to control the product composition. Reformed products of n-heptane and water mixture in an inert Ar feed could be identified as hydrogen, carbon monoxide, oxygenates, and various hydrocarbons, having a wide range of carbon numbers. To selectively increase production of short-chain hydrocarbons, Ar was replaced by CH4. An increased pool of methyl radicals, via plasma chemistry of CH4, might facilitate to stabilize intermediate alkyls (R) into RCH3, which successfully increased short-chain hydrocarbon concentration. When CO2 was supplied instead of Ar (to provide enriched OH and O radicals), significantly higher oxygenate concentrations were obtained through the stabilization of alkyls as ROH (alcohol), and RC([Formula presented])R′ (ketone). The use of methane and carbon dioxide as feed to tailor the products of plasma-assisted reforming of n-heptane with methyl (CH3), or O radicals, is successfully demonstrated in the presence of water vapor. Detailed product analysis, such as product selection, rates and energy efficiency using a gas chromatograph and a gas chromatography mass spectrometer, will be elaborated upon. © 2016 Elsevier Ltd

  13. "Chemical" composition of the Quark-Gluon Plasma in relativistic heavy-ion collisions

    CERN Document Server

    Scardina, F; Plumari, S; Greco, V

    2012-01-01

    We study the evolution of the quark-gluon composition of the plasma created in ultra-Relativistic Heavy Ion Collisions (uRHIC's) employing a partonic transport theory that includes both elastic and inelastic collisions plus a mean fields dynamics associated to the widely used quasi-particle model. The latter, able to describe lattice QCD thermodynamics, implies a "chemical" equilibrium ratio between quarks and gluons strongly increasing as $T\\rightarrow T_c$, the phase transition temperature. Accordingly we see in realistic simulations of uRHIC's a rapid evolution from a gluon dominated initial state to a quark dominated plasma close to $T_c$. The quark to gluon ratio can be modified by about a factor of $\\sim 20$ in the bulk of the system and appears to be large also in the high $p_T$ region. We discuss how this aspect, often overflown, can be essential for a quantitative study of several key issues in the QGP physics: shear viscosity, jet quenching, quarkonia suppression. Furthemore a bulk plasma made by mo...

  14. Survey of 0.1- to 16-keV/e plasma sheet ion composition

    Science.gov (United States)

    Lennartsson, W.; Shelley, E. G.

    1986-03-01

    An analysis is performed of all plasma sheet data collected in 1978-79 in order to discern statistical trends in the data. Attention is focused on the bulk parameters of 0.1-16 keV/e plasma sheet ions detected by the Plasma Composition Experiment on the ISEE 1 satellite. The data were collected at 10-23 earth radii, and are averaged for various levels of activity in the AE index. Solar H(+) and He(2+) ions dominate during quiet periods and possess energies similar to those of the solar wind when the quiet period lasts several hours. Increasing AE index values eventually lead to a replacement of the solar ions with terrestrial ions, particularly O(+), which can have an average energy density of 3-4 keV/e at every activity level. The solar ions, however, increase in energy as their density decreases. The O(+) density is highest near the local midnight and becomes the most numerous during highly disturbed conditions. Finally, the O(+) density was observed to increase by a factor of three over the monitoring period, possibly due to enhanced solar EUV radiation.

  15. Atmospheric pressure cold plasma treatment of cellulose based fillers for wood plastic composites

    Science.gov (United States)

    Lekobou, William; Englund, Karl; Pedrow, Patrick; Scudiero, Louis

    2011-10-01

    The main challenge of wood plastic composites (WPC) resides in the low interfacial adhesion due to incompatibility between the cellulose based filler that has a polar surface and most common matrixes, polyolefins which are non-polar. Plasma treatment is a promising technique for surface modification and its implementation into the processing of WPC would provide this industry with a versatile and nearly environmentally benign manufacturing tool. Our investigation aims at designing a cold atmospheric pressure plasma reactor for coating fillers with a hydrophobic material prior to compounding with the matrix. Deposition was achieved with our reactor that includes an array of high voltage needles, a grounded metal mesh, Ar as carrier gas and C2H2 as the precursor molecule. Parameters studied have included gas feed rates and applied voltage; FTIR, ESCA, AFM and SEM imaging were used for film diagnostics. We will also report on deposition rate and its dependence on radial and axial position as well as the effects of plasma-polymerized acetylene on the surface free energy of cellulose based substrates.

  16. Dietary omega-3 polyunsaturated fatty acids alter the fatty acid composition of hepatic and plasma bioactive lipids in C57BL/6 mice: a lipidomic approach.

    Directory of Open Access Journals (Sweden)

    Kayode A Balogun

    Full Text Available BACKGROUND: Omega (n-3 polyunsaturated fatty acids (PUFA are converted to bioactive lipid components that are important mediators in metabolic and physiological pathways; however, which bioactive compounds are metabolically active, and their mechanisms of action are still not clear. We investigated using lipidomic techniques, the effects of diets high in n-3 PUFA on the fatty acid composition of various bioactive lipids in plasma and liver. METHODOLOGY AND PRINCIPAL FINDINGS: Female C57BL/6 mice were fed semi-purified diets (20% w/w fat containing varying amounts of n-3 PUFA before mating, during gestation and lactation, and until weaning. Male offspring were continued on their mothers' diets for 16 weeks. Hepatic and plasma lipids were extracted in the presence of non-naturally occurring internal standards, and tandem electrospray ionization mass spectrometry methods were used to measure the fatty acyl compositions. There was no significant difference in total concentrations of phospholipids in both groups. However, there was a significantly higher concentration of eicosapentaenoic acid containing phosphatidylcholine (PC, lysophosphatidylcholine (LPC, and cholesteryl esters (CE (p < 0.01 in the high n-3 PUFA group compared to the low n-3 PUFA group in both liver and plasma. Plasma and liver from the high n-3 PUFA group also had a higher concentration of free n-3 PUFA (p < 0.05. There were no significant differences in plasma concentrations of different fatty acyl species of phosphatidylethanolamine, triglycerides, sphingomyelin and ceramides. CONCLUSIONS/SIGNIFICANCE: Our findings reveal for the first time that a diet high in n-3 PUFA caused enrichment of n-3 PUFA in PC, LPC, CE and free fatty acids in the plasma and liver of C57BL/6 mice. PC, LPC, and unesterified free n-3 PUFA are important bioactive lipids, thus altering their fatty acyl composition will have important metabolic and physiological roles.

  17. Cross-sectional associations of food consumption with plasma fatty acid composition and estimated desaturase activities in Finnish children.

    Science.gov (United States)

    Venäläinen, Taisa; Schwab, Ursula; Ågren, Jyrki; de Mello, Vanessa; Lindi, Virpi; Eloranta, Aino-Maija; Kiiskinen, Sanna; Laaksonen, David; Lakka, Timo A

    2014-05-01

    Plasma fatty acid (FA) composition is known to be an indicator of dietary fat quality, but the associations of other dietary factors with plasma FA composition remain unknown in children. We investigated the cross-sectional associations of food consumption with the proportions of FA and estimated desaturase activities in plasma cholesteryl esters (CE) and phospholipids (PL) among children. The subjects were a population sample of 423 children aged 6–8 years examined at baseline of The Physical Activity and Nutrition in Children (PANIC) Study. We assessed food consumption by food records and plasma FA composition by gas chromatography. We used linear regression models adjusted for age, sex, physical activity and total energy intake to analyze the associations. A higher consumption of vegetable oil-based margarine (fat 60–80 %) was associated with a higher proportion of linoleic and α-linolenic acids in plasma CE and PL. A higher consumption of high-fiber grain products was related to a lower proportion of oleic acid in CE and PL. The consumption of candy was directly associated with the proportion of palmitoleic and oleic acid in plasma CE. The consumption of vegetable oil-based margarine was inversely associated with estimated stearoyl-CoA-desaturase activity in plasma CE and PL and the consumption of candy was directly related to it in plasma CE. The results of our study suggest that plasma FA composition is not only a biomarker for dietary fat quality but also reflects the consumption of high-fiber grain products and foods high in sugar among children.

  18. Measurement of plasma cell-free DNA concentrations in dogs with sepsis, trauma, and neoplasia.

    Science.gov (United States)

    Letendre, Jo-Annie; Goggs, Robert

    2017-05-01

    To determine if cell-free DNA (cfDNA) was identifiable in canine plasma, to evaluate 3 techniques for the measurement of plasma cfDNA concentrations in dogs presented to an emergency service, and to compare the plasma cfDNA concentrations of healthy dogs to those with sepsis, trauma, and neoplasia. Retrospective study of banked canine plasma samples collected between May 2014 and December 2014. Dogs presented to the emergency service of a university veterinary teaching hospital. Plasma cfDNA was measured on residual plasma samples obtained from 15 dogs with sepsis, 15 dogs with moderate-severe trauma, 15 dogs diagnosed with a sarcoma. Plasma cfDNA was also measured in 15 healthy dogs. None. Assay linearity, repeatability, and reproducibility were evaluated. Quantification of cfDNA was performed in duplicate on diluted citrated plasma and following DNA purification using 2 fluorescence assays (SYBR-Gold; Quant-iT) and by ultraviolet absorbance spectroscopy. Fluorescence intensities (FIs) were converted to cfDNA concentrations using standard curves. Median FI values and cfDNA concentrations were compared to healthy controls using the Kruskal-Wallis test, with adjustment for multiple comparisons. Alpha was set at 0.05. Both assays had excellent linearity, and acceptable repeatability and reproducibility. Compared to controls, plasma cfDNA concentrations were significantly increased in dogs with sepsis or moderate-severe trauma with both assays (P ≤ 0.003). Dogs with neoplasia had significantly increased cfDNA concentrations with the Quant-iT assay only (P = 0.003). When measurements were performed on purified DNA, only dogs with moderate-severe trauma had significantly increased cfDNA concentrations (P plasma using 2 fluorescence assays. DNA extraction offers no advantage over direct measurement. Compared to healthy controls, dogs with sepsis or moderate-severe trauma have significantly increased plasma cfDNA concentrations. © Veterinary Emergency and Critical Care

  19. Measuring cross-border regional integration with composite indicators

    DEFF Research Database (Denmark)

    Makkonen, Teemu

    2016-01-01

    Earlier quantitative studies on cross-border regional integration processes have commonly neglected science, technology and innovation (STI) indicators: even the most notable example of a composite indicator approach to measuring cross-border regional integration, i.e. the Oresund index, lacks...... a sub-category for STI. Consequently, by ignoring cross-border innovation and knowledge flows, the Oresund integration index fails to take into account one of the most important drivers of economic growth in cross-border regions. Therefore, a new composite STI indicator (sub-category) was introduced...... to strengthen the Oresund integration index. This was compiled from patent, publication and collaborative R&D project data. The findings show that this index performs reasonably well in depicting STI integration, while at the same time remaining simple and straightforward enough to be adopted in other cross...

  20. The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine.

    Science.gov (United States)

    Cribb, Paul J; Williams, Andrew D; Carey, Michael F; Hayes, Alan

    2006-10-01

    Different dietary proteins affect whole body protein anabolism and accretion and therefore, have the potential to influence results obtained from resistance training. This study examined the effects of supplementation with two proteins, hydrolyzed whey isolate (WI) and casein (C), on strength, body composition, and plasma glutamine levels during a 10 wk, supervised resistance training program. In a double-blind protocol, 13 male, recreational bodybuilders supplemented their normal diet with either WI or C (1.5 gm/kg body wt/d) for the duration of the program. Strength was assessed by 1-RM in three exercises (barbell bench press, squat, and cable pull-down). Body composition was assessed by dual energy X-ray absorptiometry. Plasma glutamine levels were determined by the enzymatic method with spectrophotometric detection. All assessments occurred in the week before and the week following 10 wk of training. Plasma glutamine levels did not change in either supplement group following the intervention. The WI group achieved a significantly greater gain (P < 0.01) in lean mass than the C group (5.0 +/- 0.3 vs. 0.8 +/- 0.4 kg for WI and C, respectively) and a significant (P < 0.05) change in fat mass (-1.5 +/- 0.5 kg) compared to the C group (+0.2 +/- 0.3 kg). The WI group also achieved significantly greater (P < 0.05) improvements in strength compared to the C group in each assessment of strength. When the strength changes were expressed relative to body weight, the WI group still achieved significantly greater (P < 0.05) improvements in strength compared to the C group.

  1. Plasma concentrations of blood coagulation factor VII measured by immunochemical and amidolytic methods

    DEFF Research Database (Denmark)

    Bladbjerg, E-M; Gram, J; Jespersen, J

    2000-01-01

    plasma, in cold activated plasma and in FVII deficient plasma. There was a positive correlation (r=0.96) between FVII:Ag and FVII:Am with slightly but significantly higher values for FVII:Ag (FVII:Ag= 106 U/ml and FVII:Am=100 U/ml; p ...Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII......:Ag) or estimated with an amidolytic method (FVII:Am). We have investigated whether FVII:Am is a valuable alternative to FVII:Ag. FVII:Ag and FVII:Am were measured in 147 plasma samples from blood donors, patients on oral anticoagulant therapy, postmenopausal women on hormone replacement therapy, in postprandial...

  2. Measurements of Electron Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

    Science.gov (United States)

    Oh, Jaechul; Weaver, J. L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Karasik, M.; Chan, L.-Y.; Serlin, V.; Phillips, L.

    2013-10-01

    Knowing spatial profiles of electron density (ne) in the underdense coronal region (n Nike LPI experiment, a side-on grid imaging refractometer (GIR) was deployed for measuring the underdense plasma profiles. Plasmas were produced from flat CH targets illuminated by Nike KrF laser with total energies up to 1 kJ of 0.5 ~ 1 nsec FWHM pulses. The GIR resolved ne up to 3 ×1021 /cm3 in space taking 2D snapshot images of probe laser (λ = 263 nm, Δt = 10 ps) beamlets (50 μm spacing) refracted by the plasma at a selected time during the laser illumination. The individual beamlet transmittances were also measured for Te estimation. Time-resolved spectrometers with an absolute-intensity-calibrated photodiode array and a streak camera simultaneously detected light emission from the plasma in spectral ranges relevant to Raman (SRS) and two plasmon decay instabilities. The measured spatial profiles are compared with simulation results from the FAST3D radiation hydrocode and their effects on the LPI observations are investigated. Work supported by DoE/NNSA and performed at Naval Research Laboratory.

  3. Lack of correlation of glucose levels in filtered blood plasma to density and conductivity measurements.

    Science.gov (United States)

    Gordon, David M; Ash, Stephen R

    2009-01-01

    The purpose of this research project was to determine whether the glucose level of a blood plasma sample from a diabetic patient could be predicted by measuring the density and conductivity of ultrafiltrate of plasma created by a 30,000 m.w. cutoff membrane. Conductivity of the plasma filtrate measures electrolyte concentration and should correct density measurements for changes in electrolytes and water concentration. In vitro studies were performed measuring conductivity and density of solutions of varying glucose and sodium chloride concentrations. Plasma from seven hospitalized patients with diabetes was filtered across a 30,000 m.w. cutoff membrane. The filtrate density and conductivity were measured and correlated to glucose levels. In vitro studies confirmed the ability to predict glucose from density and conductivity measurements, in varying concentrations of glucose and saline. In plasma filtrate, the conductivity and density measurements of ultrafiltrate allowed estimation of glucose in some patients with diabetes but not others. The correlation coefficient for the combined patient data was 0.45 which was significant but only explained 20% of the variability in the glucose levels. Individually, the correlation was significant in only two of the seven patients with correlation coefficients of 0.79 and 0.88. The reasons for lack of correlation are not clear, and cannot be explained by generation of idiogenic osmoles, effects of alcohol dehydrogenase, water intake, etc. This combination of physical methods for glucose measurement is not a feasible approach to measuring glucose in plasma filtrate.

  4. Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade

    DEFF Research Database (Denmark)

    Horacek, J.; Adamek, J.; Müller, H.W.

    2010-01-01

    This paper focuses on interpretation of fast (1 µs) and local (2–4 mm) measurements of plasma density, potential and electron temperature in the edge plasma of tokamak ASDEX Upgrade. Steady-state radial profiles demonstrate the credibility of the ball-pen probe. We demonstrate that floating poten...

  5. Laser ablation of (GeSe2)100-x(Sb2Se3)x chalcogenide glasses: Influence of the target composition on the plasma plume dynamics

    Science.gov (United States)

    Irimiciuc, S.; Boidin, R.; Bulai, G.; Gurlui, S.; Nemec, P.; Nazabal, V.; Focsa, C.

    2017-10-01

    The dynamics and properties of the (GeSe2)100-x(Sb2Se3)x laser-induced plasma were investigated by fast ICCD imaging and space- and time-resolved optical emission spectroscopy (OES). The experiments were performed at 10-6 Torr background pressure, using the second harmonic (532 nm) of the Nd-YAG laser (10 ns, 10 Hz). For all investigated samples, the ICCD images revealed a splitting of the plasma plume into three components with distinct dynamics. Based on OES measurements, the first and second plasma structures were found to be represented mainly by ionic and neutral species, respectively. As the Sb2Se3 content of the samples increases, the three structures present an increase in their velocities. This dynamic variation and also the compositional dependence of the excitation temperature obtained from Boltzmann plots were correlated to the changes in the structure and electrical/thermal properties of the bulk chalcogenide glasses.

  6. Drifting plasma collection by a positive biased tether wire in LEO-like plasma conditions: current measurement and plasma diagnostic

    OpenAIRE

    Siguier, Jean-Michel; Sarrailh, Pierre; Roussel, Jean-François; Inguimbert, Virgine; Murat, Gaël; Sanmartín Losada, Juan Ramón

    2013-01-01

    BETs is a three-year project financed by the Space Program of the European Commission, aimed at developing an efficient deorbit system that could be carried on board any future satellite launched into Low Earth Orbit (LEO). The operational system involves a conductive tape-tether left bare to establish anodic contact with the ambient plasma as a giant Langmuir probe. As a part of this project, we are carrying out both numerical and experimental approaches to estimate the collected current by ...

  7. Mass composition measurements at the Pierre Auger Observatory

    Science.gov (United States)

    Molina Bueno, L.; Pierre Auger Collaboration

    2015-11-01

    The Pierre Auger Observatory is the largest ultra-high energy cosmic ray experiment built so far. It is a hybrid detector, since it measures both the fluorescence light emitted while the air showers develop in the atmosphere and the particles reaching the ground. We present the results related to the mass composition of ultra-high energy cosmic rays as obtained from both types of measurements. The depth at which the maximum of the electromagnetic development takes place and its fluctuations are the most sensitive parameters to infer the nature of the cosmic rays. In addition, we present the latest muon measurements that can be used to test and constrain models of hadronic interactions at energies larger than those reached at LHC.

  8. Methods of gas purification and effect on the ion composition in an RF atmospheric pressure plasma jet investigated by mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grosse-Kreul, Simon; Huebner, Simon; Schneider, Simon; Keudell, Achim von; Benedikt, Jan [Ruhr-Universitaet Bochum, Institute for Experimental Physics II, Bochum (Germany)

    2016-12-15

    The analysis of the ion chemistry of atmospheric pressure plasmas is essential to evaluate ionic reaction pathways during plasma-surface or plasma-analyte interactions. In this contribution, the ion chemistry of a radio-frequency atmospheric pressure plasma jet (μ-APPJ) operated in helium is investigated by mass spectrometry (MS). It is found, that the ion composition is extremely sensitive to impurities such as N{sub 2}, O{sub 2} and H{sub 2}O. Without gas purification, protonated water cluster ions of the form H{sup +}(H{sub 2}O){sub n} are dominating downstream the positive ion mass spectrum. However, even after careful feed gas purification to the sub-ppm level using a molecular sieve trap and a liquid nitrogen trap as well as operation of the plasma in a controlled atmosphere, the positive ion mass spectrum is strongly influenced by residual trace gases. The observations support the idea that species with a low ionization energy serve as a major source of electrons in atmospheric pressure helium plasmas. Similarly, the neutral density of atomic nitrogen measured by MS in a He/N{sub 2} mixture is varying up to a factor 3, demonstrating the significant influence of impurities on the neutral species chemistry as well. (orig.)

  9. The Effect of Plasma Spraying on the Microstructure and Aging Kinetics of the Al-Si Matrix Alloy and Al-Si/SiC Composites

    Science.gov (United States)

    Altunpak, Yahya; Akbulut, Hatem; Üstel, Fatih

    2010-02-01

    The Al-Si (LM 13)-based matrix alloy reinforced with SiC particles containing 10, 20, and 30 vol.% SiC particles were spray-formed onto Al-Si substrates. The sprayed samples were directly subjected to a standard aging treatment (T551). From the experiments, it was observed that the high rate of solidification resulted in very fine silicon particles which were observed as continuous islands in the matrix and each island exhibited several very fine silicon crystals. Analysis showed that plasma-spraying caused an increased solid solubility of the silicon in the aluminum matrix. DSC measurements in the permanent mold-cast Al-Si matrix alloy and plasma-sprayed Al-Si matrix alloy showed that plasma-spraying causes an increase in the amount of GP-zone formation owing to the very high rate solidification after plasma-spraying. In the plasma-sprayed Al-Si/SiC composites GP zones were suppressed, since particle-matrix interfaces act as a sink for vacancies during quenching from high plasma process temperature. Introduction of SiC particles to the Al-Si age-hardenable alloy resulted in a decrease in the time required to reach plateau matrix hardness owing to acceleration of aging kinetics by ceramic SiC particles.

  10. [Preoperative digitalization. Measurement of digoxin plasma levels (author's transl)].

    Science.gov (United States)

    Geiger, H J; Rietbrock, N

    1976-09-01

    In a study of 233 patients from the department of surgery and anesthesiology taking digoxin preparations 64, per cent exhibit digoxin levels in the therapeutic range (0.6--1.5 ng/ml), 19 per cent had subtoxic concentrations ranged from 1.6--2.0 ng/ml and 7 per cent were in the toxic range (greater than 2 ng/ml). In patients treated with digoxin before admission to hospital subtherapeutic levels were most frequent. An average loading dose of digoxin 1 mg or more on one day may result in subtoxic and toxic digoxin levels on the second day, in patients receiving less than 1 mg digoxin daily an increasing frequency of plasma digoxin concentrations of 1.5 ng/ml or higher values was present on the third day. Averaged plasma digoxin concentrations were correlated with daily maintenance dose. There was, however, a wide individual variation in digoxin plasma concentrations. A low incidence of toxic digoxin plasma levels was observed in patients receiving a daily oral maintenance dose of 0.375 mg digoxin (Lanicor). For prophylactic digitalization of patients with normal renal and thyroid function the following schedules or statistical guidlines are proposed: Lanicor (bioavailability 60%): oral loading dose of 0.75 mg over two days, and then daily oral maintenance dose of 0.375 mg; Novodigal (bioavailability 80%): oral loading dose of 0.6 mg over two days and then daily oral maintenance dose of 0.3 mg; Digoxin i.v.: intravenous loading dose of 0.5 (0.4) mg over two days and then 0.25 (0.2) mg daily intravenous maintenance dose. For any patient needing treatment with digitalis glycosides therapy must be individual and dynamic. The reasons for toxic concentrations were frequently attributed to wrong dosage.

  11. Solar Cluster: multipoint magnetic field and plasma parameter measurements in the solar wind

    Science.gov (United States)

    Vieira, L. E.; Echer, E.; dal Lago, A.; Schuch, N. J.

    This paper has the objective to discus the technical-scientific feasibility of a deep space mission to be proposed to the Brazilian Space Agency (AEB). This mission will be proposed to study the interplanetary magnetic field and the plasma structure of the solar wind. It will consist of a set of identical spacecraft flying in formation in the inner heliosphere during the ascending and maximum phase of the solar cycle 24. It is know that the primary cause of magnetic storms are intense, long duration southward interplanetary magnetic field structures which interconnect with the earth's magnetic field and allow solar wind energy transport into the Earth's magnetotail/magnetosphere. During the most active phase of the solar cycle, solar maximum, the sun's activity is dominated by flares and disappearing filaments, and their concomitant Coronal Mass Ejections (CMEs). Coronal Holes are present, but the holes are small and do not extend from the poles to the equator as often happens in the descending phase of the solar cycle. The fast (>500 km/s) CMEs coming from the sun into the interplanetary space are the solar/coronal features that contain high magnetic fields. These intense southward magnetic fields are observed in the sheath, in the ejection itself and in the rear of the ejection. The interaction between CMEs and the background solar wind, fast co rotating streams and other CMEs are also very important sources of intense southward magnetic fields. In order to study the interplanetary origin of intense geomagnetic storms, several studies have analyzed plasma parameters, composition, ionization state and the interplanetary magnetic field measured by instruments on board of spacecraft as ISEE3, IMP8, Helios, Ulysses, Wind, SOHO and ACE. Great advance on the understanding of the CME structure and interaction with the background solar wind have been reached. However, the spatial scale of these structures could be greater than 0.2 AU, and this kind of observation usually

  12. Soft X-ray measurements in magnetic fusion plasma physics

    Science.gov (United States)

    Botrugno, A.; Gabellieri, L.; Mazon, D.; Pacella, D.; Romano, A.

    2010-11-01

    Soft X-ray diagnostic systems and their successful application in the field of magnetic fusion plasma physics are discussed. Radiation with wavelength in the region of Soft X-Ray (1-30 keV) is largely produced by high temperature plasmas, carrying important information on many processes during a plasma discharge. Soft X-ray diagnostics are largely used in various fusion devices all over the world. These diagnostic systems are able to obtain information on electron temperature, electron density, impurity transport, Magneto Hydro Dynamic instabilities. We will discuss the SXR diagnostic installed on FTU in Frascati (Italy) and on Tore Supra in Cadarache (France), with special emphasis on diagnostic performances. Moreover, we will discuss the two different inversion methods for tomographic reconstruction used in Frascati and in Cadarache, the first one is relied on a guessed topology of iso-emissivity surfaces, the second one on regularization techniques, like minimum Fisher or maximum entropy. Finally, a new and very fast 2D imaging system with energy discrimination and high time resolution will be summarized as an alternative approach of SXR detection system.

  13. Calibrated automated thrombin generation measurement in clotting plasma.

    Science.gov (United States)

    Hemker, H Coenraad; Giesen, Peter; Al Dieri, Raed; Regnault, Véronique; de Smedt, Eric; Wagenvoord, Rob; Lecompte, Thomas; Béguin, Suzette

    2003-01-01

    Calibrated automated thrombography displays the concentration of thrombin in clotting plasma with or without platelets (platelet-rich plasma/platelet-poor plasma, PRP/PPP) in up to 48 samples by monitoring the splitting of a fluorogenic substrate and comparing it to a constant known thrombin activity in a parallel, non-clotting sample. Thus, the non-linearity of the reaction rate with thrombin concentration is compensated for, and adding an excess of substrate can be avoided. Standard conditions were established at which acceptable experimental variation accompanies sensitivity to pathological changes. The coefficients of variation of the surface under the curve (endogenous thrombin potential) are: within experiment approximately 3%; intra-individual: AVK, heparin(-likes), direct inhibitors]. In PRP, it is diminished in von Willebrand's disease, but it also shows the effect of platelet inhibitors (e.g. aspirin and abciximab). Addition of activated protein C (APC) or thrombomodulin inhibits thrombin generation and reflects disorders of the APC system (congenital and acquired resistance, deficiencies and lupus antibodies) independent of concomitant inhibition of the procoagulant pathway as for example by anticoagulants.

  14. Towards an exploitation of IAGOS atmospheric composition measurements

    Science.gov (United States)

    Marshall, Julia; Gerbig, Christoph; Petzold, Andreas; Zahn, Andreas

    2015-04-01

    IAGOS, In-service Aircraft for a Global Observing System, has installed instrumentation on a growing fleet of commercial airliners in order to continuously monitor atmospheric composition around the globe. IAGOS is providing accurate in situ observations of greenhouse gases (GHGs), reactive gases, aerosols, and cloud particles at high spatial resolution in the free atmosphere, thereby covering the essential climate variables (ECVs) for atmospheric composition as designated by the GCOS programme (Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC, 2010). The greenhouse gas measurements made by IAGOS will be submitted to the WMO/GAW World Data Centre for Greenhouse Gases (WDCGG). Within the EU FP7 project IGAS (IAGOS for the GMES Atmospheric Service), the links between this new data stream and scientific users, including the Copernicus Atmosphere Monitoring Service, are being improved. This includes the provision of measurements in both near-real-time and delayed mode, and improved accessibility to the data through linkages to the databases of both the German Aerospace Centre (DLR) flight campaign archive and the Copernicus data archive. Work has been undertaken to investigate the use of the near-real-time profile measurements in order to correct bias in satellite measurements assimilated by the Copernicus Atmosphere Monitoring Service. Documentation of the QA/QC procedures and measurement techniques for each instrument have been formalized and reviewed by external experts, to provide users with a measurement traceable to WMO standards. The representativeness of the measurements has been assessed, to better interpret results in polluted regions and near the tropopause. The potential impact of the GHG measurements on regional scale flux inversions has been quantified, which is relevant for ICOS (Integrated Carbon Observing System). Finally, tools have been developed to use the measurements for validation of satellite column

  15. Measuring the parameters of a high flux plasma in Proto-MPEX

    Science.gov (United States)

    Skeen, C.; Biewer, T. M.; Cantrell, C. L.; Klemm, J. C.; Musick, R. A.; Nunley, G.; Salazar Sanchez, J. S.; Sawyer, D. J.; Ray, H.; Shaw, G.; Showers, M.

    2016-10-01

    The Prototype Material Plasma Exposure Experiment (Proto-MPEX) is a linear, magnetically confined plasma production device, utilizing a helicon antenna. The plasma column interacts with a material target at the end of the device, creating plasma-material interaction conditions that are relevant to the conditions that are expected in future fusion reactors. Moreover, helicon antenna plasma sources have been proposed as propulsion devices for spacecraft. It has been observed that in some circumstances the Proto-MPEX plasma exerts sufficient force on the target plate to cause the target to recoil. A ballistic probe has been designed to measure the force and heat flux profile of the plasma. The probe response has been calibrated, using scales, thermocouples, and fast camera imaging. The ballistic probe has been inserted into Proto-MPEX plasmas and the heat flux profile of the plasma has been measured. Also the maximum force that is exerted on the probe has been estimated. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725, and the Oak Ridge Associated Universities ARC program.

  16. In-situ measurement of deuterium retention in W under plasma exposure

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T., E-mail: watanabe-takashi13@ees.nagoya-u.ac.jp [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kaneko, T. [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Matsunami, N. [Faculty of Science and Technology, Meijo University, Nagoya 468-0073 (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Kajita, S.; Kuwabara, T. [EcoTopia Science Institute, Nagoya University, Nagoya 464-8603 (Japan)

    2015-08-15

    The time dependence of the deuterium (D) retention in tungsten (W) was investigated by conducting successive D and hydrogen (H) plasma exposure using the plasma surface dynamics with ion beam analysis (PS-DIBA) device, which can conduct in-situ D retention measurement. At the sample temperature of 450 K, D retention rapidly dropped after the termination of D plasma exposure. On the other hand, at the sample temperature of 350 K, a slow decay of D retention after termination of D plasma was observed. The results indicate that the sample temperature has a strong influence on the dynamic behavior of D retention in W. Furthermore, by successive H plasma exposure to D retained W, D retention in W decreased exponentially in time. The result suggests that successive H plasma exposure is one of effective methods to remove tritium in W.

  17. First results from the plasma composition spectrometer PROMICS-3 in the Interball project

    Directory of Open Access Journals (Sweden)

    I. Sandahl

    Full Text Available PROMICS-3 is a plasma experiment flown in the Russian project Interball. It performs three-dimensional (3D measurements of ions in the energy range 4 eV–70 keV with mass separation and of electrons in the energy range 12 eV–35 keV. The Interball project consists of two main satellites, the Tail Probe and the Auroral Probe, each with one subsatellite. The Interball Tail Probe was launched on 3 August 1995, into a 65° inclination orbit with apogee at about 30 RE. Both main satellites carry identical PROMICS-3 instruments and thus direct comparisons of the particle distributions will be possible once the Auroral Probe is launched. Furthermore, PROMICS-3-Tail is the first instrument measuring the 3D ion distribution function in the magnetospheric boundary layers at high latitudes. In this paper we describe the PROMICS-3 instrument and show initial results from the Tail probe, measurements of the magnetosheath, plasma sheet, and ring current plasmas.

  18. Biomimetic apatite-based composite materials obtained by spark plasma sintering (SPS): physicochemical and mechanical characterizations.

    Science.gov (United States)

    Brouillet, Fabien; Laurencin, Danielle; Grossin, David; Drouet, Christophe; Estournes, Claude; Chevallier, Geoffroy; Rey, Christian

    2015-08-01

    Nanocrystalline calcium phosphate apatites are biomimetic compounds analogous to bone mineral and are at the origin of the bioactivity of most biomaterials used as bone substitutes. Their unique surface reactivity originates from the presence of a hydrated layer containing labile ions (mostly divalent ones). So the setup of 3D biocompatible apatite-based bioceramics exhibiting a high reactivity requests the development of «low» temperature consolidation processes such as spark plasma sintering (SPS), in order to preserve the characteristics of the hydrated nanocrystals. However, mechanical performances may still need to be improved for such nanocrystalline apatite bioceramics, especially in view of load-bearing applications. The reinforcement by association with biopolymers represents an appealing approach, while preserving the advantageous biological properties of biomimetic apatites. Herein, we report the preparation of composites based on biomimetic apatite associated with various quantities of microcrystalline cellulose (MCC, 1-20 wt%), a natural fibrous polymer. The SPS-consolidated composites were analyzed from both physicochemical (X-ray diffraction, Fourier transform infrared, solid state NMR) and mechanical (Brazilian test) viewpoints. The preservation of the physicochemical characteristics of apatite and cellulose in the final material was observed. Mechanical properties of the composite materials were found to be directly related to the polymer/apatite ratios and a maximum crushing strength was reached for 10 wt% of MCC.

  19. Fabrication of W–1 wt.% TiC composites by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xiao-Yu [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Lai-Ma, E-mail: luolaima@126.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Laboratories of Nonferrous Metal Material and Processing Engineering of Anhui Province, Hefei 230009 (China); Chen, Hong-Yu [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhu, Xiao-Yong; Zan, Xiang; Cheng, Ji-Gui [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Laboratories of Nonferrous Metal Material and Processing Engineering of Anhui Province, Hefei 230009 (China); Wu, Yu-Cheng, E-mail: ycwu@hfut.edu.cn [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Laboratories of Nonferrous Metal Material and Processing Engineering of Anhui Province, Hefei 230009 (China)

    2015-03-15

    Graphical abstract: - Highlights: • TiC/W nanoparticles with core–shell structure were produced by chemical method. • TiC particles were dispersed in the tungsten grains and grain boundaries. • The grain size and relative density of W–TiC composite were 3 μm and 98.6%, respectively. - Abstract: TiC/W ultra-fine powders were produced by one-step activation and chemical reduction process. The powders were consolidated by spark plasma sintering (SPS) at 1800 °C to suppress grain growth during sintering. The grain size, relative density and the Vicker hardness HV{sub 0.2} of the bulk sample fabricated by SPS were 3 μm, 98.6% and 471, respectively. The reduced Young's elastic modulus of the sintered W–1 wt.% TiC composites was 382.7 GPa. As the temperature rises from room temperature (RT) to 1100 K, the thermal conductivity of pure W and W–1 wt.% TiC composites decreased with the same trend. However, the thermal conductivity of the samples was both above 120 W/m K at RT.

  20. Impact of surface structure and feed gas composition on Bacillus subtilis endospore inactivation during direct plasma treatment

    OpenAIRE

    Christian eHertwig; Veronika eSteins; Kai eReineke; Antje eRademacher; Michael eKlocke; Cornelia eRauh; Oliver eSchlüter

    2015-01-01

    This study investigated the inactivation efficiency of cold atmospheric pressure plasma treatment on Bacillus subtilis endospores dependent on the used feed gas composition and on the surface, the endospores were attached on. Glass petri-dishes, glass beads and peppercorns were inoculated with the same endospore density and treated with a radio frequency plasma jet. Generated reactive species were detected using optical emission spectroscopy. A quantitative polymerase chain reaction (qPCR) ba...

  1. Time resolved measurements of the CF{sub 2} rotational temperature in pulsed fluorocarbon rf plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, O; Stepanov, S; Pfafferott, M; Meichsner, J [Institute of Physics, University of Greifswald, Domstrasse 10a, D-17498, Greifswald (Germany)

    2006-11-01

    Knowledge of the absolute densities of small radicals like CF, CF{sub 2} and CF{sub 3} in fluorocarbon plasmas is essential for a fundamental understanding of plasma chemical processes and plasma surface interaction. Infrared absorption spectroscopy by means of tunable diode lasers (IR-TDLAS) was established and widely used for density measurements in the last decade. The often unknown parameter in the calculation of absolute radical densities from a measured absorption of a single line is the rotational temperature. In particular, a strong dependence of the line strength on rotational temperature has a significant influence on density calculation. In this paper we report on measurements of the CF{sub 2} rotational temperature in capacitively coupled CF{sub 4}/H{sub 2} plasmas (CCP) with rf (13.56 MHz) powers up to 200 W. Rotational temperatures in continuous and pulsed modes of the discharge were found to be between 300 and 450 K. Furthermore, first measurements of the time dependence of the rotational temperature in pulsed rf plasma are presented. The rotational temperature rises in the plasma phase within 0.1 s and goes down again to the temperature of the background gas in the plasma pause within 0.5 s. It is also shown that accurate density measurements of the radicals by means of single line absorption need correct information about the rotational temperature and careful selection of a suitable absorption line.

  2. Advanced Measurements of Silicon Carbide Ceramic Matrix Composites

    Energy Technology Data Exchange (ETDEWEB)

    Farhad Farzbod; Stephen J. Reese; Zilong Hua; Marat Khafizov; David H. Hurley

    2012-08-01

    Silicon carbide (SiC) is being considered as a fuel cladding material for accident tolerant fuel under the Light Water Reactor Sustainability (LWRS) Program sponsored by the Nuclear Energy Division of the Department of Energy. Silicon carbide has many potential advantages over traditional zirconium based cladding systems. These include high melting point, low susceptibility to corrosion, and low degradation of mechanical properties under neutron irradiation. In addition, ceramic matrix composites (CMCs) made from SiC have high mechanical toughness enabling these materials to withstand thermal and mechanical shock loading. However, many of the fundamental mechanical and thermal properties of SiC CMCs depend strongly on the fabrication process. As a result, extrapolating current materials science databases for these materials to nuclear applications is not possible. The “Advanced Measurements” work package under the LWRS fuels pathway is tasked with the development of measurement techniques that can characterize fundamental thermal and mechanical properties of SiC CMCs. An emphasis is being placed on development of characterization tools that can used for examination of fresh as well as irradiated samples. The work discuss in this report can be divided into two broad categories. The first involves the development of laser ultrasonic techniques to measure the elastic and yield properties and the second involves the development of laser-based techniques to measurement thermal transport properties. Emphasis has been placed on understanding the anisotropic and heterogeneous nature of SiC CMCs in regards to thermal and mechanical properties. The material properties characterized within this work package will be used as validation of advanced materials physics models of SiC CMCs developed under the LWRS fuels pathway. In addition, it is envisioned that similar measurement techniques can be used to provide process control and quality assurance as well as measurement of

  3. Hydrogen storage and hydrolysis properties of core-shell structured Mg-MFx (M=V, Ni, La and Ce) nano-composites prepared by arc plasma method

    Science.gov (United States)

    Mao, Jianfeng; Zou, Jianxin; Lu, Chong; Zeng, Xiaoqin; Ding, Wenjiang

    2017-10-01

    In this work, core-shell structured Mg-MFx (M = V, Ni, La and Ce) nano-composites are prepared by using arc plasma method. The particle size distribution, phase components, microstructures, hydrogen sorption properties of these composites and hydrolysis properties of their corresponding hydrogenated powders are carefully investigated. It is shown that the addition of MFx through arc plasma method can improve both the hydrogen absorption kinetics of Mg and the hydrolysis properties of corresponding hydrogenated powders. Among them, the Mg-NiF2 composite shows the best hydrogen absorption properties at relatively low temperatures, which can absorb 3.26 wt% of H2 at 373 K in 2 h. Such rapid hydrogen absorption rate is mainly due to the formation of Mg2Ni and MgF2 on Mg particles during arc evaporation and condensation. In contrast, measurements also show that the hydrogenated Mg-VF3 composite has the lowest peak desorption temperature and the fastest hydrolysis rate among all the hydrogenated Mg-MFx composites. The less agglomeration tendency of Mg particles and VO2 covered on MgH2 particles account for the reduced hydrogen desorption temperature and enhanced hydrolysis rate.

  4. Non-thermal Atmospheric Plasma Treatment for Deactivation of Oral Bacteria and Improvement of Dental Composite Restoration

    Science.gov (United States)

    Yu, Qing Song; Li, H.; Ritts, A. C.; Yang, B.; Chen, M.; Hong, L.; Xu, C.; Yao, X.; Wang, Y.

    This paper reviews our recent research results of using non-thermal ­atmospheric plasmas for oral bacterial deactivation and for composite restoration improvement. Oral bacteria of Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus) with an initial bacterial population density between 1.0 × 108 and 5.0 × 108 cfu/ml were seeded on various media and their survivability with plasma exposure was examined. The plasma exposure time for a 99.9999% cell reduction was less than 15 s for S. mutans and within 5 min for L. acidophilus. To evaluate the dentin/composite interfacial bonding, extracted unerupted human third molars were used by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. After dental composite application and light curing, the teeth were then sectioned into micro-bars as the specimens for microtensile test. Student Newman Keuls (SNK) tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s plasma treatment of the dentin surfaces. These findings indicated that non-thermal atmospheric plasma technology is very promising for dental clinical applications.

  5. Data management software concept for WEST plasma measurement system

    Science.gov (United States)

    Zienkiewicz, P.; Kasprowicz, G.; Byszuk, A.; Wojeński, A.; Kolasinski, P.; Cieszewski, R.; Czarski, T.; Chernyshova, M.; Pozniak, K.; Zabolotny, W.; Juszczyk, B.; Mazon, D.; Malard, P.

    2014-11-01

    This paper describes the concept of data management software for the multichannel readout system for the GEM detector used in WEST Plasma experiment. The proposed system consists of three separate communication channels: fast data channel, diagnostics channel, slow data channel. Fast data channel is provided by the FPGA with integrated ARM cores providing direct readout data from Analog Front Ends through 10GbE with short, guaranteed intervals. Slow data channel is provided by multiple, fast CPUs after data processing with detailed readout data with use of GNU/Linux OS and appropriate software. Diagnostic channel provides detailed feedback for control purposes.

  6. Accuracy of plasma turbidity measurement for determining fat intolerance during total parenteral nutrition.

    Science.gov (United States)

    Nordenström, J; Thörne, A; Lindholm, M

    1990-06-01

    The accuracy of plasma turbidity measurements in predicting ability to metabolise intravenous fat emulsions during total parenteral nutrition was studied in 35 adult surgical patients. Plasma turbidity, expressed as a light scattering index (LSI), was determined by nephelometry and compared with measured triglyceride (TG) concentrations. A poor coefficient of correlation was found between LSI and TG (r = 0.52). The sensitivity and specificity of LSI in predicting TG concentration were 19% and 96% respectively. This indicates that the measurement of LSI is more useful in ruling out hypertriglyceridaemia than in detecting it. Consequently, clinical tolerance of intravenous fat emulsion cannot be monitored by measuring plasma turbidity. In order to avoid metabolic complications which may occasionally occur during intravenous nutritional therapy including fat emulsion, determination of plasma TG levels at timed intervals are recommended.

  7. Plasma concentration of parasite DNA as a measure of disease severity in falciparum malaria

    NARCIS (Netherlands)

    Imwong, M.; Woodrow, C.; Hendriksen, I.C.E.; Veenemans, J.; Verhoef, J.C.M.

    2015-01-01

    In endemic areas malaria parasitemia is common in apparently healthy children and severe malaria is commonly misdiagnosed in patients with incidental parasitemia. We assessed the performance of plasma P. falciparum DNA concentration measurement in distinguishing uncomplicated from severe malaria in

  8. The influence of methane/argon plasma composition on the formation of the hydrogenated amorphous carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hsin-Hung [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Liao, Jiunn-Der, E-mail: jdliao@mail.ncku.edu.t [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Weng, Chih-Chiang; Hsieh, Jui-Fu; Chang, Chia-Wei [Department of Materials Science and Engineering, National Cheng Kung University, No. 1, University Road, Tainan 70101, Taiwan (China); Lin, Chao-Hsien; Cho, Ting-Pin [Metal Industries Development and Research Centre, 1001 Kaonan Highway, Kaohsiung 811, Taiwan (China)

    2011-01-03

    The quality of the a-C:H films was particularly correlated with the mixed ratio of methane/argon plasma. For a constant supply of energy and flowing rate, the optical emission from H{sub {alpha}} intensity linearly increased with the addition of methane in argon plasma, while that from intensities of radiation of diatmoic radicals (CH*and C{sub 2}*) exponentially decreased. For the a-C:H films, the added methane in argon plasma tended to raise the quantity of hydrogenated carbon or sp{sup 3} C-H structure, which exponentially decreased the nano-hardness and friction coefficient of the films. In contrast, the electric resistance of the films enlarged dramatically with the increase of the methane content in argon plasma. It is therefore advantageous to balance the mechanical properties and electrical resistance of the a-C:H film by adjusting plasma composition in the course of the film-growing process.

  9. Effects of Calcium on ATPase Activity and Lipid Composition of Plasma Membranes from Wheat Roots Under Aluminum Stress

    Institute of Scientific and Technical Information of China (English)

    HE Long-fei; SHEN Zhen-guo; LIU You-liang

    2003-01-01

    Effects of calcium on ATPase activities, lipid contents, and fatty acid compositions of plasma membrane from wheat roots were assayed under aluminum stress. The results showed that the increase of calcium concentration in the nutrient solution increased the activity of H+-ATPase and the phospholipid content, decreased the activity of Ca2+-ATPase and the galactolipid of plasma membrane. Owing to the decrease of linolenic acid content, the index of unsaturated fatty acid (IUFA) and index of double bond (DBI) decreased in Altas66. The IUFA and DBI of plasma membrane from Scout66 roots increased because its linolenic acid content increased obviously and its palmitic acid content decreased apparently.

  10. Digital Holography for in Situ Real-Time Measurement of Plasma-Facing-Component Erosion

    Energy Technology Data Exchange (ETDEWEB)

    ThomasJr., C. E. [Third Dimension Technologies, LLC, Knoxville, TN; Granstedt, E. M. [Tri-Alpha Energy; Biewer, Theodore M [ORNL; Baylor, Larry R [ORNL; Combs, Stephen Kirk [ORNL; Meitner, Steven J [ORNL; Hillis, Donald Lee [ORNL; Majeski, R. [Princeton Plasma Physics Laboratory (PPPL); Kaita, R. [Princeton Plasma Physics Laboratory (PPPL)

    2014-01-01

    In situ, real time measurement of net plasma-facing-component (PFC) erosion/deposition in a real plasma device is challenging due to the need for good spatial and temporal resolution, sufficient sensitivity, and immunity to fringe-jump errors. Design of a high-sensitivity, potentially high-speed, dual-wavelength CO2 laser digital holography system (nominally immune to fringe jumps) for PFC erosion measurement is discussed.

  11. Current distribution measurements inside an electromagnetic plasma gun operated in a gas-puff mode

    OpenAIRE

    Poehlmann, Flavio R.; Cappelli, Mark A.; Rieker, Gregory B.

    2010-01-01

    Measurements are presented of the time-dependent current distribution inside a coaxial electromagnetic plasma gun. The measurements are carried out using an array of six axially distributed dual-Rogowski coils in a balanced circuit configuration. The radial current distributions indicate that operation in the gas-puff mode, i.e., the mode in which the electrode voltage is applied before injection of the gas, results in a stationary ionization front consistent with the presence of a plasma def...

  12. Spectroscopic metrology for isotope composition measurements and transfer standards

    Science.gov (United States)

    Anyangwe Nwaboh, Javis; Balslev-Harder, David; Kääriäinen, Teemu; Richmond, Craig; Manninen, Albert; Mohn, Joachim; Kiseleva, Maria; Petersen, Jan C.; Werhahn, Olav; Ebert, Volker

    2017-04-01

    The World Meteorological Organization (WMO) has identified greenhouse gases such as CO2, CH4 and N2O as critical for global climate monitoring. Other molecules such as CO that has an indirect effect of enhancing global warming are also monitored. WMO has stated compatibility goals for atmospheric concentration and isotope ratio measurements of these gases, e.g. 0.1 ppm for CO2 concentration measurements in the northern hemisphere and 0.01 ‰ for δ13C-CO2. For measurements of the concentration of greenhouse gases, gas analysers are typically calibrated with static gas standards e.g. traceable to the WMO scale or to the International System of Units (SI) through a national metrology institute. However, concentrations of target components, e.g. CO, in static gas standards have been observed to drift, and typically the gas matrix as well as the isotopic composition of the target component does not always reflect field gas composition, leading to deviations of the analyser response, even after calibration. The deviations are dependent on the measurement technique. To address this issue, part of the HIGHGAS (Metrology for high-impact greenhouse gases) project [1] focused on the development of optical transfer standards (OTSs) for greenhouse gases, e.g. CO2 and CO, potentially complementing gas standards. Isotope ratio mass spectrometry (IRMS) [2] is currently used to provide state-of-the-art high precision (in the 0.01 ‰ range) measurements for the isotopic composition of greenhouse gases. However, there is a need for field-deployable techniques such as optical isotope ratio spectroscopy (OIRS) that can be combined with metrological measurement methods. Within the HIGHGAS project, OIRS methods and procedures based on e.g. cavity enhanced spectroscopy (CES) and tunable diode laser absorption spectroscopy (TDLAS), matched to metrological principles have been established for the measurement of 13C/12C and 18O/16O ratios in CO2, 15N/14N ratios in N2O, and 13C/12C and 2H

  13. Measuring Moisture Levels in Graphite Epoxy Composite Sandwich Structures

    Science.gov (United States)

    Nurge, Mark; Youngquist, Robert; Starr, Stanley

    2011-01-01

    Graphite epoxy composite (GEC) materials are used in the construction of rocket fairings, nose cones, interstage adapters, and heat shields due to their high strength and light weight. However, they absorb moisture depending on the environmental conditions they are exposed to prior to launch. Too much moisture absorption can become a problem when temperature and pressure changes experienced during launch cause the water to vaporize. The rapid state change of the water can result in structural failure of the material. In addition, heat and moisture combine to weaken GEC structures. Diffusion models that predict the total accumulated moisture content based on the environmental conditions are one accepted method of determining if the material strength has been reduced to an unacceptable level. However, there currently doesn t exist any field measurement technique to estimate the actual moisture content of a composite structure. A multi-layer diffusion model was constructed with Mathematica to predict moisture absorption and desorption from the GEC sandwich structure. This model is used in conjunction with relative humidity/temperature sensors both on the inside and outside of the material to determine the moisture levels in the structure. Because the core materials have much higher diffusivity than the face sheets, a single relative humidity measurement will accurately reflect the moisture levels in the core. When combined with an external relative humidity measurement, the model can be used to determine the moisture levels in the face sheets. Since diffusion is temperaturedependent, the temperature measurements are used to determine the diffusivity of the face sheets for the model computations.

  14. A Method for Measurement of Dynamic Sheath Behavior in Plasma Immersion Ion Implantation and Deposition Process

    Institute of Scientific and Technical Information of China (English)

    WU Hongchen; MA Guojia; PENG Liping; FENG Jianji; ZHANG Huafang; MA Tengcai

    2008-01-01

    A method to measure temporal and spatial evolution of sheath in plasma immersion ion implantation (PⅢ) process is presented.A long Langrnuir probe (φ 5 mm×φ 78 mm) with low bias is used to detect the sheath propagation and backup with time.The aubstrate made of Al cylinder (φ20 mm×φ150 mm) is immersed in nitrogen and argon plasma induced by magnetron self-sustained discharge.The maximum sheath sizes,at different plasma densities under different discharge currents,are measured and compared.

  15. K-alpha conversion efficiency measurments for x-ray scattering in inertial confinement fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kritcher, A L; Neumayer, P; Urry, M K; Robey, H; Niemann, C; Landen, O L; Morse, E; Glenzer, S H

    2006-11-21

    The conversion efficiency of ultra short-pulse laser radiation to K-{alpha} x-rays has been measured for various chlorine-containing targets to be used as x-ray scattering probes of dense plasmas. The spectral and temporal properties of these sources will allow spectrally-resolved x-ray scattering probing with picosecond temporal resolution required for measuring the plasma conditions in inertial confinement fusion experiments. Simulations of x-ray scattering spectra from these plasmas show that fuel capsule density, capsule ablator density, and shock timing information may be inferred.

  16. Classical Heat-Flux Measurements in Coronal Plasmas from Collective Thomson-Scattering Spectra

    Science.gov (United States)

    Henchen, R. J.; Hu, S. X.; Katz, J.; Froula, D. H.; Rozmus, W.

    2016-10-01

    Collective Thomson scattering was used to measure heat flux in coronal plasmas. The relative amplitude of the Thomson-scattered power into the up- and downshifted electron plasma wave features was used to determine the flux of electrons moving along the temperature gradient at three to four times the electron thermal velocity. Simultaneously, the ion-acoustic wave features were measured. Their relative amplitude was used to measure the flux of the return-current electrons. The frequencies of these ion-acoustic and electron plasma wave features provide local measurements of the electron temperature and density. These spectra were obtained at five locations along the temperature gradient in a laser-produced blowoff plasma. These measurements of plasma parameters are used to infer the Spitzer-Härm flux (qSH = - κ∇Te ) and are in good agreement with the values of the heat flux measured from the scattering-feature asymmetries. Additional experiments probed plasma waves perpendicular to the temperature gradient. The data show small effects resulting from heat flux compared to probing waves along the temperature gradient. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  17. Compositional changes of lithium coatings on TZM molybdenum during plasma bombardment

    Science.gov (United States)

    Abrams, T.; Jaworski, M. A.; Kaita, R.; de Temmerman, G.; Gleeson, M. A.; Lof, A. R.; Scholten, J.; van den Berg, M. A.; van der Meiden, H. J.; Raman, P.; Ruzic, D. N.

    2012-10-01

    The Titanium-Zirconium-Molybdenum alloy TZM has previously been used as a metallic plasma-facing component in Alcator C-Mod is being considered for use in NSTX-Upgrade. The time evolution of lithium (Li) coatings on TZM are studied in Magnum-PSI, a linear plasma device capable of ion fluxes up to 10^25 m-2s-1 at electron temperatures mean free path (MFP) of Li was calculated and validations against the ADAS collisional-radiative model (CRM) will be reported. Separate measurements with a 100-1000 eV D^+ ion beam incident on Li-coated TZM were also obtained and compared with theoretical predictions of physical sputtering rates.

  18. Trace elemental composition of curry by inductively coupled plasma optical emission spectrometry (ICP-OES).

    Science.gov (United States)

    Gonzálvez, A; Armenta, S; De La Guardia, M

    2008-01-01

    A methodology based on inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave-assisted acid digestion was developed to determine the content of traces elements in curry samples from the Spanish market. The methodology was validated in terms of accuracy by the analysis of citrus and tomato leaf reference materials achieving comparable results with the certified values. The trace metal content of curry samples was compared with data available from previously published reports concerning Indian samples, especially in terms of heavy metal composition, in order to guarantee the quality of the commercially available spices in the European countries. Values found for the analysis of arsenic, lead and cadmium were significantly lower than the maximum limit allowed by European Union statutory limits for heavy metals and lower than those obtained for Indian curry leaves reported by Indian research teams by using neutron activation and γ-ray analysis.

  19. Langmuir Probe Measurements in an Inductively Coupled Ar/CF4 Plasmas

    Science.gov (United States)

    Rao, M. V. V. S.; Meyyappan, M.; Sharma, S. P.; Arnold, James O. (Technical Monitor)

    2000-01-01

    Technological advancement in the microelectronics industry requires an understanding of the physical and chemical processes occurring in plasmas of fluorocarbon gases, such as carbon tetrafluoride (CF4) which is commonly used as an etchant, and their mixtures to optimize various operating parameters. In this paper we report data on electron number density (ne), electron temperature'(Te), electron energy distribution function (EEDF), mean electron energy, ion number density (ni), and plasma potential (Vp) measured by using Langmuir probe in an inductively coupled 13.56 MHz radio frequency plasmas generated in 50%Ar:50%CF4 mixture in the GEC cell. The probe data were recorded at various radial positions providing radial profiles of these plasma parameters at 10-50 mTorr pressures and 200 W and 300 W of RF power. Present measurements indicate that the electron and ion number densities increase with increase in pressure and power. Whereas the plasma potential and electron temperature decrease with increase in pressure, and they weakly depend on RF power. The radial profiles exhibit that the electron and ion number densities and the plasma potential peak at the center of the plasma with an exponential fall away from it, while the electron temperature has a minimum at the center and it increases steadily towards the electrode edge. The EEDFs have a characteristic drop near the low energy end at all pressures and pressures and their shapes represent non-Maxwellian plasma and exhibit more like Druyvesteyn energy distribution.v

  20. Force measurements on natural membrane nanovesicles reveal a composition-independent, high Young's modulus

    Science.gov (United States)

    Calò, Annalisa; Reguera, David; Oncins, Gerard; Persuy, Marie-Annick; Sanz, Guenhaël; Lobasso, Simona; Corcelli, Angela; Pajot-Augy, Edith; Gomila, Gabriel

    2014-01-01

    Mechanical properties of nano-sized vesicles made up of natural membranes are crucial to the development of stable, biocompatible nanocontainers with enhanced functional, recognition and sensing capabilities. Here we measure and compare the mechanical properties of plasma and inner membrane nanovesicles ~80 nm in diameter obtained from disrupted yeast Saccharomyces cerevisiae cells. We provide evidence of a highly deformable behaviour for these vesicles, able to support repeated wall-to-wall compressions without irreversible deformations, accompanied by a noticeably high Young's modulus (~300 MPa) compared to that obtained for reconstituted artificial liposomes of similar size and approaching that of some virus particles. Surprisingly enough, the results are approximately similar for plasma and inner membrane nanovesicles, in spite of their different lipid compositions, especially on what concerns the ergosterol content. These results point towards an important structural role of membrane proteins in the mechanical response of natural membrane vesicles and open the perspective to their potential use as robust nanocontainers for bioapplications.Mechanical properties of nano-sized vesicles made up of natural membranes are crucial to the development of stable, biocompatible nanocontainers with enhanced functional, recognition and sensing capabilities. Here we measure and compare the mechanical properties of plasma and inner membrane nanovesicles ~80 nm in diameter obtained from disrupted yeast Saccharomyces cerevisiae cells. We provide evidence of a highly deformable behaviour for these vesicles, able to support repeated wall-to-wall compressions without irreversible deformations, accompanied by a noticeably high Young's modulus (~300 MPa) compared to that obtained for reconstituted artificial liposomes of similar size and approaching that of some virus particles. Surprisingly enough, the results are approximately similar for plasma and inner membrane nanovesicles, in

  1. Thrust Stand Measurements of the Microwave Assisted Discharge Inductive Plasma Accelerator

    Science.gov (United States)

    Hallock, Ashley K.; Polzin, Kurt A.; Emsellem, Gregory D.

    2011-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. This type of pulsed thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Dis- charge Inductive Plasma Accelerator (MAD-IPA), shown in Fig. 1, is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil before the main current pulse via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and a static magnetic field from a set of permanent magnets arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the theta-pinch coil is high. The use of a conical theta-pinch coil also serves to provide neutral propellant containment and plasma plume focusing that is improved relative to the more common planar geometry of the Pulsed Inductive Thruster (PIT) [1, 2]. In this paper, we describe thrust stand measurements performed to characterize the performance (specific impulse, thrust efficiency) of the MAD-IPA thruster. Impulse data are obtained at various pulse energies, mass flow rates and inductive coil geometries. Dependencies on these experimental parameters are discussed in the context of the current sheet formation and electromagnetic plasma

  2. Low temperature alters plasma membrane lipid composition and ATPase activity of pineapple fruit during blackheart development.

    Science.gov (United States)

    Zhou, Yuchan; Pan, Xiaoping; Qu, Hongxia; Underhill, Steven J R

    2014-02-01

    Plasma membrane (PM) plays central role in triggering primary responses to chilling injury and sustaining cellular homeostasis. Characterising response of membrane lipids to low temperature can provide important information for identifying early causal factors contributing to chilling injury. To this end, PM lipid composition and ATPase activity were assessed in pineapple fruit (Ananas comosus) in relation to the effect of low temperature on the development of blackheart, a form of chilling injury. Chilling temperature at 10 °C induced blackheart development in concurrence with increase in electrolyte leakage. PM ATPase activity was decreased after 1 week at low temperature, followed by a further decrease after 2 weeks. The enzyme activity was not changed during 25 °C storage. Loss of total PM phospholipids was found during postharvest senescence, but more reduction was shown from storage at 10 °C. Phosphatidylcholine and phosphatidylethanolamine were the predominant PM phospholipid species. Low temperature increased the level of phosphatidic acid but decreased the level of phosphatidylinositol. Both phospholipid species were not changed during storage at 25 °C. Postharvest storage at both temperatures decreased the levels of C18:3 and C16:1, and increased level of C18:1. Low temperature decreased the level of C18:2 and increased the level of C14:0. Exogenous application of phosphatidic acid was found to inhibit the PM ATPase activity of pineapple fruit in vitro. Modification of membrane lipid composition and its effect on the functional property of plasma membrane at low temperature were discussed in correlation with their roles in blackheart development of pineapple fruit.

  3. Evaluation and Characterization of Plasma Sprayed Cu Slag-Al Composite Coatings on Metal Substrates

    Directory of Open Access Journals (Sweden)

    S. Mantry

    2013-01-01

    Full Text Available Copper slag is a waste product obtained during matte smelting and refining of copper. The present work explores the coating potential of copper slag by plasma spraying. This work shows that copper slag is eminently coatable. An attempt has been made in the present investigation to use the composites coatings of copper slag and Al powder in suitable combination on aluminium and mild steel substrates in order to improve the surface properties of these ductile metal-alloy substrates. When premixed with Al powder, the coating exhibits higher interfacial adhesion as compared to pure copper slag coatings. Maximum adhesion strengths of about 23 MPa and 21 MPa are recorded for the coatings of copper slag with 15 wt% of Al on aluminium and mild steel substrates, respectively. The input power to the plasma torch is found to affect the coating deposition efficiency and morphology of the coatings. It also suggests value addition of an industrial waste.

  4. RF Plasma Torch System for Metal Matrix Composite Production in Nuclear Fuel Cladding

    Science.gov (United States)

    Holik, Eddie, III

    2007-10-01

    For the first time in 30 years, plans are afoot to build new fission power plants in the US. It is timely to develop technology that could improve the safety and efficiency of new reactors. A program of development for advanced fuel cycles and Generation IV reactors is underway. The path to greater efficiency is to increase the core operating temperature. That places particular challenges to the cladding tubes that contain the fission fuel. A promising material for this purpose is a metal matrix composite (MMC) in which ceramic fibers are bonded within a high-strength steel matrix, much like fiberglass. Current MMC technology lacks the ability to effectively bond traditional high-temperature alloys to ceramic strands. The purpose of this project is to design an rf plasma torch system to use titanium as a buffer between the ceramic fibers and the refractory outer material. The design and methods of using an rf plasma torch to produce a non-equilibrium phase reaction to bond together the MMC will be discussed. The effects of having a long lived fuel cladding in the design of future reactors will also be discussed.

  5. 2D simulations of hohlraum targets for laser-plasma experiments and ion stopping measurement in hot plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Basko, M.M. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany). ExtreMe Matter Institute EMMI; Maruhn, J.; Tauschwitz, Anna [Frankfurt Univ. (Germany); Novikov, V.G.; Grushin, A.S. [Keldysh Institute of Applied Mathematics, Moscow (Russian Federation)

    2011-12-15

    An attractive way to create uniform plasma states at high temperatures and densities is by using hohlraums - cavities with heavy-metal walls that are either directly or indirectly heated by intense laser pulses to x-ray temperatures of tens and hundreds electron volts. A sample material, whose plasma state is to be studied, can be placed inside such a hohlraum (usually in the form of a low-density foam) and uniformly heated to a high temperature. In this case a high-Z hohlraum enclosure serves a double purpose: it prevents the hot plasma from rapid disassembly due to hydrodynamic expansion and, at the same time, suppresses its rapid radiative cooling by providing high diffusive resistivity for X-rays. Of course, both the inertial and the thermal confinement of high-temperature plasmas can be achieved only for a limited period of time - on the order of nanoseconds for millimeter-scale hohlraums. Some time ago such hohlraum targets were proposed for measurements of the stopping power of hot dense plasmas for fast ions at GSI (Darmstadt). Theoretical modeling of hohlraum targets has always been a challenging task for computational physics because it should combine multidimensional hydrodynamic simulations with the solution of the spectral transfer equation for thermal radiation. In this work we report on our latest progress in this direction, namely, we present the results of 2D (two-dimensional) simulations with a newly developed radiation-hydrodynamics code RALEF-2D of two types of the hohlraum targets proposed for experiments on the PHELIX laser at GSI. The first configuration is a simple spherical hohlraum with gold walls and empty interior, which has two holes - one for laser beam entrance, and the other for diagnostics. The hohlraums of this type have already been used in several experimental sessions with the NHELIX and PHELIX lasers at GSI. The second type is a two-chamber cylindrical hohlraum with a characteristic {omega}-shaped cross-section of the enclosure

  6. Gastric emptying in rats following administration of a range of different fats measured as acetaminophen concentration in plasma

    DEFF Research Database (Denmark)

    Porsgaard, Trine; Straarup, Ellen Marie; Høy, Carl-Erik

    2003-01-01

    Aim: To investigate the gastric emptying upon administration of ten different fats in order to determine whether major differences in fatty acid profiles resulted in differences in gastric emptying. Methods: Gastric emptying was measured as the appearance of acetaminophen in plasma which represents...... butter as well as different structured lipids containing decanoic acid (10:0) and long-chain n-3 polyunsaturated fatty acids of marine origin. Overall, these fats had wide variations in fatty acid compositions and triacylglycerol structures. Results: No statistically significant differences were observed...... of this fat as compared with the other fats, because similar weights of fat were administered. Conclusion: The gastric emptying of fat was not influenced by fatty acid composition and triacylglycerol structure of the fats administered....

  7. Plasma dynamics near critical density inferred from direct measurements of laser hole boring.

    Science.gov (United States)

    Gong, Chao; Tochitsky, Sergei Ya; Fiuza, Frederico; Pigeon, Jeremy J; Joshi, Chan

    2016-06-01

    We have used multiframe picosecond optical interferometry to make direct measurements of the hole boring velocity, v_{HB}, of the density cavity pushed forward by a train of CO_{2} laser pulses in a near critical density helium plasma. As the pulse train intensity rises, the increasing radiation pressure of each pulse pushes the density cavity forward and the plasma electrons are strongly heated. After the peak laser intensity, the plasma pressure exerted by the heated electrons strongly impedes the hole boring process and the v_{HB} falls rapidly as the laser pulse intensity falls at the back of the laser pulse train. A heuristic theory is presented that allows the estimation of the plasma electron temperature from the measurements of the hole boring velocity. The measured values of v_{HB}, and the estimated values of the heated electron temperature as a function of laser intensity are in reasonable agreement with those obtained from two-dimensional numerical simulations.

  8. Measurement and model on thermal properties of sintered diamond composites

    Energy Technology Data Exchange (ETDEWEB)

    Moussa, Tala, E-mail: Tala.moussa@univ-nantes.fr [Laboratoire de Thermocinetique UMR CNRS 6607, Polytech, Universite de nantes, BP 50609, rue Christian Pauc, 44306 Nantes (France); Garnier, Bertrand; Peerhossaini, Hassan [Laboratoire de Thermocinetique UMR CNRS 6607, Polytech, Universite de nantes, BP 50609, rue Christian Pauc, 44306 Nantes (France)

    2013-02-25

    Highlights: Black-Right-Pointing-Pointer Thermal properties of sintered diamond used for grinding is studied. Black-Right-Pointing-Pointer Flash method with infrared temperature measurement is used to investigate. Black-Right-Pointing-Pointer Thermal conductivity increases with the amount of diamond. Black-Right-Pointing-Pointer It is very sensitive to binder conductivity. Black-Right-Pointing-Pointer Results agree with models assuming imperfect contact between matrix and particles. - Abstract: A prelude to the thermal management of grinding processes is measurement of the thermal properties of working materials. Indeed, tool materials must be chosen not only for their mechanical properties (abrasion performance, lifetime Horizontal-Ellipsis ) but also for thermal concerns (thermal conductivity) for efficient cooling that avoids excessive temperatures in the tool and workpiece. Sintered diamond is currently used for grinding tools since it yields higher performances and longer lifetimes than conventional materials (mineral or silicon carbide abrasives), but its thermal properties are not yet well known. Here the thermal conductivity, heat capacity and density of sintered diamond are measured as functions of the diamond content in composites and for two types of metallic binders: hard tungsten-based and soft cobalt-based binders. The measurement technique for thermal conductivity is derived from the flash method. After pulse heating, the temperature of the rear of the sample is measured with a noncontact method (infrared camera). A parameter estimation method associated with a three-layer nonstationary thermal model is used to obtain sample thermal conductivity, heat transfer coefficient and absorbed energy. With the hard metallic binder, the thermal conductivity of sintered diamond increased by up to 64% for a diamond content increasing from 0 to 25%. The increase is much less for the soft binder: 35% for diamond volumes up to 25%. In addition, experimental data

  9. Effect of particle size on the microstructure and thermal conductivity of Al/diamond composites prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    CHU Ke; JIA Chengchang; LIANG Xuebing; CHEN Hui; GAO Wenjia

    2009-01-01

    Spark plasma sintering (SPS) was used to fabricate Al/diamond composites. The influence of diamond particle size on the microstrueture and thermal conductivity (TC) of composites was investigated by combining experimental results with model prediction. The results show that both composites with 40 μm particles and 70 μm particles exhibit high density and good TC, and the composite with 70 μm particles indi-cates an excellent TC of 325 W·m~(-1)·K~(-1). Their TCs lay between the theoretical estimated bounds. In contrast, the composite with 100 μm particles demonstrates low density as well as poor TC due to its high porosity and weak interfacial bonding. Its TC is even considerably less than the lower bound of the predicted value. Using larger diamond particles can further enhance thermal conductive performance only based on the premise that highly dense composites of strong interfacial bonding can be obtained.

  10. Measurements of Rotational Temperatures in Atmospheric-Pressure Capillary Plasma Electrode (CPE) Discharge

    Science.gov (United States)

    Figus, Margaret; Abramzon, Nina; Becker, Kurt

    2003-10-01

    We report the results of rotational temperature measurements in atmospheric-pressure capillary plasma electrode (CPE) discharges in ambient air using the unresolved N2 second positive band. Assuming that the emitting N2 molecules can be described by a Maxwell-Boltzmann distribution characterized by a single rotational temperature, this temperature is determined from a fit of the measured emission spectrum to a calculated spectrum. If the emitting species are in equilibrium with the bulk gas in the plasma, then this temperature can be interpreted as the gas kinetic temperature in the plasma. We determined rotational temperatures for three different plasma regions: inside the capillary by analyzing radiation emitted along the axis of the capillary, between the capillaries, and perpendicular to the axis of the capillary. Each region has a different plasma density and, therefore, a different gas temperature with the plasma inside the capillary being the hottest. We also measured the rotational temperatures in each region as a function of the plasma power. As expected, the rotational temperatures increase with increasing discharge power. Work supported by the NSF and by ARO through a DURIP award.

  11. Measurement of Surface Strains from a Composite Hydrofoil using Fibre Bragg Grating Sensing Arrays

    Science.gov (United States)

    2015-07-01

    UNCLASSIFIED UNCLASSIFIED Measurement of Surface Strains from a Composite Hydrofoil using Fibre Bragg Grating Sensing Arrays Claire...arrays to the surface of a composite hydrofoil and reports on an experiment to measure surface strains from the hydrofoil under static and fatigue...July 2015 APPROVED FOR PUBLIC RELEASE UNCLASSIFIED UNCLASSIFIED Measurement of Surface Strains from a Composite Hydrofoil using

  12. Development of density measurement method of negative ion in plasmas using laser Thomson scattering

    Science.gov (United States)

    Yamagata, Yukihiko; Saiho, Hiroatsu; Uchino, Kiichiro; Muraoka, Katsunori

    2004-09-01

    Measurements of negative ion density in plasmas have been an important subject for many years. We have proposed a new method to measure the negative ion density in plasmas using laser Thomson scattering (LTS), and successfully measured O^- ion density in an radio frequency inductively coupled plasma [1]. In order to ensure the reliability of this technique and to estimate the accuracy, we have measured O^- ion density in the same experimental conditions using the second (SHG) and third harmonics (THG) of a Nd:YAG laser as different laser sources. The LTS spectra measured at pure argon plasma (500 W, 20 mTorr) fitted in a straight line well in both SHG and THG cases. As for the plasma at 500 W in 20 mTorr with Ar/O_2=95%/5%, a clear bump in LTS spectra, which is caused by photo-detached electrons, was observed below 0.9 eV for the SHG case and 2 eV for the case, as predicted by a difference between the electron affinity of O^- ion and the laser photon energy. The electron temperatures, the electron densities and the O^- ion densities, which were obtained from the spectral shape and intensity of both LTS spectra, were in agreement each other within an experimental error. [1] M. Noguchi, K. Ariga, T. Hirao, P. Suanpoot, Y. Yamagata, K. Uchino, K. Muraoka, Plasma Sources Sci. Technol., 11 (2002) 57.

  13. Tokamak Plasmas : Electron temperature $(T_{e})$ measurements by Thomson scattering system

    Indian Academy of Sciences (India)

    R Rajesh; B Ramesh Kumar; S K Varshney; Manoj Kumar; Chhaya Chavda; Aruna Thakkar; N C Patel; Ajai Kumar; Aditya Team

    2000-11-01

    Thomson scattering technique based on high power laser has already proved its superoirity in measuring the electron temperature (e) and density (e) in fusion plasma devices like tokamaks. The method is a direct and unambiguous one, widely used for the localised and simultaneous measurements of the above parameters. In Thomson scattering experiment, the light scattered by the plasma electrons is used for the measurements. The plasma electron temperature is measured from the Doppler shifted scattered spectrum and density from the total scattered intensity. A single point Thomson scattering system involving a -switched ruby laser and PMTs as the detector is deployed in ADITYA tokamak to give the plasma electron parameters. The system is capable of providing the parameters e from 30 eV to 1 keV and e from 5 × 1012 cm-3-5× 1013 cm-3. The system is also able to give the parameter profile from the plasma center ( = 0 cm) to a vertical position of = +22 cm to = -14 cm, with a spatial resolution of 1 cm on shot to shot basis. This paper discusses the initial measurements of the plasma temperature from ADITYA.

  14. Measures of cardiorespiratory fitness in relation to measures of body size and composition among children.

    Science.gov (United States)

    Tompuri, Tuomo; Lintu, Niina; Savonen, Kai; Laitinen, Tomi; Laaksonen, David; Jääskeläinen, Jarmo; Lakka, Timo A

    2015-11-01

    In the exercise testing measures of cardiorespiratory fitness need to be scaled by body size or composition to enable comparison between individuals. Traditionally used weight-proportional measures are potentially confounded by body adiposity that hampers their interpretation and applicability in the clinical assessment of cardiorespiratory fitness. We aimed to find the most appropriate measure of body size or composition for scaling of measures of cardiorespiratory fitness among children. We assessed body weight and height, maximal workload (W MAX ) and maximal oxygen uptake (VO2 MAX ) using cycle ergometer exercise test with respiratory gas analysis and body lean mass (LM) and fat mass (FM) by dual-energy X-ray absorptiometry and by bioimpedance analysis among 38 children. The data were analysed using Pearson's coefficients for correlation and stepwise linear regression models. Lean mass (r > 0.54) and height (r > 0.51) had stronger positive correlations with absolute W MAX and VO2 MAX than weight (r > 0.30) in girls and boys. None of the measures of body size or composition correlated with LM-proportional W MAX or VO2 MAX in girls or boys. Only LM correlated positively with height-proportional W MAX (r = 0.65) and VO2 MAX (r = 0.71) in boys. FM correlated negatively with weight-proportional W MAX (r VO2 MAX (r MAX (β = -0.68) and VO2 MAX (β = -0.61) than exercise performance in multivariate linear regression models. While assessing cardiorespiratory fitness, LM is the most appropriate measure of body size or composition for scaling of W MAX and VO2 MAX, because scaling by body weight introduces confounding by body adiposity. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  15. Tuning the afterglow plasma composition in Ar/N2/O2 mixtures: characteristics of a flowing surface-wave microwave discharge system

    Science.gov (United States)

    Kutasi, Kinga; Noël, Cédric; Belmonte, Thierry; Guerra, Vasco

    2016-10-01

    A self-consistent kinetic model is used to study the possibility of tuning the plasma composition in the afterglow of a flowing surface-wave microwave discharge by the different discharge and system parameters in the case of 90%Ar-10%(N2-O2) and N2-O2 mixtures. The afterglow system consists of a 0.5 cm diameter quartz tube of 50 cm in length—where the discharge is generated and the early-afterglow develops—and an afterglow reactor. The plasma composition is studied at the end of the discharge plasma column and at the reactor inlet as a function of the N2:O2 ratio for selected conditions, which are set with the system parameters and are illustrated in the experimental set-up. The validity of the model used is proven by the agreement of the calculated atomic densities with those measured by mass spectrometry. Due to the pressure drop along the tube, the position of the discharge (which also defines the lengths of the early-afterglow, t aft) and the discharge pressure (p dis) can be set with the position of the wave coupler—surfatron—along the tube at a constant gas flow rate (which defines the pressure in the reactor, p reac). It is shown that the relative densities of species at the end of plasma column, which constitute the initial condition for the afterglow, depend on the discharge pressure. Therefore, at a constant gas flow rate with the position of the surfatron the plasma composition in the reactor is changing due to the variation of both the p dis and t aft. The evolution of the plasma composition is also studied when both the surfatron’s position and the gas flow rate are changed, realizing conditions (i) with the same p dis, and different t aft and p reac, and (ii) with the same t aft, and different p dis and p reac. Comparing the N2-O2 binary and the ternary mixtures, it is shown that the atomic densities obtained in the binary mixtures can be reproduced in ternary mixtures with different N2:O2 ratios. Furthermore, according to the spectra

  16. Calculation of 2-temperature plasma thermo-physical properties considering condensed phases: application to CO2-CH4 plasma: part 1. Composition and thermodynamic properties

    Science.gov (United States)

    Wu, Yi; Chen, Zhexin; Rong, Mingzhe; Cressault, Yann; Yang, Fei; Niu, Chunping; Sun, Hao

    2016-10-01

    As the first part of this series of papers, a new calculation method for composition and thermodynamic properties of 2-temperature plasma considering condensed species under local chemical equilibrium (LCE) and local phase equilibrium assumption is presented. The 2-T mass action law and chemical potential are used to determine the composition of multiphase system. The thermo-physical properties of CO2-CH4 mixture, which may be a possible substitution for SF6, are calculated by this method as an example. The influence of condensed graphite, non-LTE effect, mixture ratio and pressure on the thermo-physical properties has been discussed. The results will serve as reliable reference data for computational simulation of CO2-CH4 plasmas.

  17. Structural and electrical measurements of CdZnSe composite

    Indian Academy of Sciences (India)

    V Kishore; Vibhav K Saraswat; N S Saxena; T P Sharma

    2005-08-01

    The – characterization and the electrical resistivity of selenium rich Se85Cd15–Zn ( = 0, 3, 7, 11 and 15) system at room temperature have been studied. Samples were obtained using melt cooling technique. So prepared samples were then characterized in terms of their crystal structure and lattice parameter using X-ray diffraction method. The materials were found to be polycrystalline in nature, having zinc blend structure over the whole range of zinc concentration. The measurements of – characteristics have been carried out at different temperatures from room to 140°C. The electrical resistivity of the samples with composition at room temperature has been found to vary between maximum 2.7 × 108 m and minimum 7.3 × 105 m and shows a maximum at 3 at. wt.% of Zn. The carrier activation energy of the samples with composition has also been determined and found to vary from 0.026 eV to 0.111 eV.

  18. Raman measurement of carotenoid composition in human skin

    Science.gov (United States)

    Ermakov, Igor V.; Ermakova, Maia R.; Gellermann, Werner

    2004-07-01

    The carotenoids lycopene and beta-carotene are powerful antioxidants in skin and are thought to act as scavengers for free radicals and singlet oxygen. The role of carotenoid species in skin health is of strong current interest. We demonstrate the possibility to use Resonance Raman spectroscopy for fast, non-invasive, highly specific, and quantitative detection of beta-carotene and lycopene in human skin. Analyzing Raman signals originating from the carbon-carbon double bond stretch vibrations of the carotenoid molecules under blue and green laser excitation, we were able to characterize quantitatively the relative concentrations of each carotenoid species in-vivo. In the selective detection, we take advantage of different Raman cross-section spectral profiles for beta-carotene and lycopene molecules, and obtain a quantitative assessment of individual long-chain carotenoid species in the skin rather than their cumulative levels. Preliminary dual-wavelength Raman measurements reveal significant differences in the carotenoid composition of different subjects. The technique holds promise for rapid screening of carotenoid compositions in human skin in large populations and may be suitable in clinical studies for assessing the risk for cutaneous diseases.

  19. Implications of solar wind measurements for solar models and composition

    Science.gov (United States)

    Serenelli, Aldo; Scott, Pat; Villante, Francesco L.; Vincent, Aaron C.; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Peña-Garay, Carlos

    2016-11-01

    We critically examine recent claims of a high solar metallicity by von Steiger & Zurbuchen (2016, vSZ16) based on in situ measurements of the solar wind, rather than the standard spectroscopically inferred abundances (Asplund et al. 2009, hereafter AGSS09). We test the claim by Vagnozzi et al. (2016) that a composition based on the solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar modelling problem. We show that, although some helioseismological observables are improved compared to models computed with spectroscopic abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted 8B flux that is nearly twice its observed value, and 7Be and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances are worse than AGSS09 despite a higher metallicity. We also present astrophysical and spectroscopic arguments showing the vSZ16 composition to be an implausible representation of the solar interior, identifying the first ionization potential effect in the outer solar atmosphere and wind as the likely culprit.

  20. Deposition of hybrid organic-inorganic composite coatings using an atmospheric plasma jet system.

    Science.gov (United States)

    Dembele, Amidou; Rahman, Mahfujur; Reid, Ian; Twomey, Barry; MacElroy, J M Don; Dowling, Denis P

    2011-10-01

    The objective of this study is to investigate the influence of alcohol addition on the incorporation of metal oxide nanoparticles into nm thick siloxane coatings. Titanium oxide (TiO2) nanoparticles with diameters of 30-80 nm were incorporated into an atmospheric plasma deposited tetramethylorthosilicate (TMOS) siloxane coating. The TMOS/TiO2 coating was deposited using the atmospheric plasma jet system known as PlasmaStream. In this system the liquid precursor/nanoparticle mixture is nebulised into the plasma. It was observed that prior to being nebulised the TiO2 particles agglomerated and settled over time in the TMOS/TiO2 mixture. In order to obtain a more stable nanoparticle/TMOS suspension the addition of the alcohols methanol, octanol and pentanol to this mixture was investigated. The addition of each of these alcohols was found to stabilise the nanoparticle suspension. The effect of the alcohol was therefore assessed with respect to the properties of the deposited coatings. It was observed that coatings deposited from TMOS/TiO2, with and without the addition of methanol were broadly similar. In contrast the coatings deposited with octanol and pentanol addition to the TMOS/TiO2 mixture were significantly thicker, for a given set of deposition parameters and were also more homogeneous. This would indicate that the alcohol precursor was incorporated into the plasma polymerised siloxane. The incorporation of the organic functionality from the alcohols was confirmed from FTIR spectra of the coatings. The difference in behaviour with alcohol type is likely to be due to the lower boiling point of methanol (65 degrees C), which is lower than the maximum plasma temperature measured at the jet orifice (77 degrees C). This temperature is significantly lower than the 196 degrees C and 136 degrees C boiling points of octanol and pentanol respectively. The friction of the coatings was determined using the Pin-on-disc technique. The more organic coatings deposited with

  1. Plasma treatment of carbon fibers: Non-equilibrium dynamic adsorption and its effect on the mechanical properties of RTM fabricated composites

    Science.gov (United States)

    Ma, Keming; Wang, Baichen; Chen, Ping; Zhou, Xia

    2011-02-01

    The effect of oxygen plasma treatment on the non-equilibrium dynamic adsorption of the carbon fabric reinforcements in RTM process was studied. 5-Dimethylamino-1-naphthalene-sulfonylchloride (DNS-Cl) was attached to the curing agent to study the change of curing agent content in the epoxy resin matrix. Steady state fluorescence spectroscopy (FS) analysis was used to study this changes in the epoxy resin at the inlet and outlet of the RTM mould, and XPS was used to study the chemical changes on the carbon fiber surfaces introduced by plasma treatment. The interlaminar shear strength (ILSS) and flexural strength were also measured to study the effects of this non-equilibrium dynamic adsorption progress on the mechanical properties of the end products. FS analysis shows that the curing agent adsorbed onto the fiber surface preferentially for untreated carbon fiber, the curing agent content in the resin matrix maintain unchanged after plasma treatment for 3 min and 5 min, but after oxygen plasma treatment for 7 min, the epoxy resin adsorbed onto the fiber surface preferentially. XPS analysis indicated that the oxygen plasma treatment successfully increased some polar functional groups concentration on the carbon fiber surfaces, this changes on the carbon fiber surfaces can change the adsorption ability of carbon fiber to the resin and curing agent. The mechanical properties of the composites were correlated to this results.

  2. Strength and failure behaviour of spark plasma sintered steel-zirconia composites under compressive Loading

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, L.; Decker, S.; Ehinger, D. [Institute of Materials Engineering, TU Bergakademie Freiberg (Germany); Ohser-Wiedemann, R.; Martin, S.; Martin, U.; Seifert, H.J. [Institute of Materials Science, TU Bergakademie Freiberg (Germany)

    2011-09-15

    Several composites, consisting of a metastable austenitic steel matrix and varying amounts of MgO partially stabilized zirconia particles (Mg-PSZ), were produced through spark plasma sintering (SPS). Compression tests were carried out at room temperature in a wide range of strain rate (4 . 10{sup -4} s{sup -1}, 2 . 10{sup -3} s{sup -1}, 10{sup -1} s{sup -1}, 1 s{sup -1}, 10{sup 2} s{sup -1}). In conjunction with subsequent microstructural investigations, the mechanical material behaviour was clarified. All composites showed a good ductility and a high strength. The strength increased with an increase of the ceramic content and with higher strain rates. Both, the martensitic transformation of the steel matrix and of the ceramic particles, could be proved at all strain rates. In this study no significant influence of the strain rate on the amount of transformed ceramic could be detected while the steel matrix showed less {alpha}'-martensite after compression at rising strain rates. Local material failure occurred around 0.3 true compressive strain depending on the applied strain rate and the amount of the Mg-PSZ powder. The main reason for the damage is the relatively weak ceramic-ceramic interface within the ceramic clusters. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Ouabain Modulates the Lipid Composition of Hippocampal Plasma Membranes from Rats with LPS-induced Neuroinflammation.

    Science.gov (United States)

    Garcia, Israel José Pereira; Kinoshita, Paula Fernanda; Scavone, Cristoforo; Mignaco, Julio Alberto; Barbosa, Leandro Augusto de Oliveira; Santos, Hérica de Lima

    2015-12-01

    The effects of ouabain (OUA) and lipopolysaccharide (LPS) in vivo on hippocampal membranes (RHM) of Wistar male rats aged 3 months were analyzed. After intraperitoneal (i.p.) injection of OUA only, LPS only, OUA plus LPS, or saline, the content of proteins, phospholipids, cholesterol and gangliosides from RHM was analyzed. The total protein and cholesterol contents of RHM were not significantly affected by OUA or LPS for the experimentally paired groups. In contrast, total phospholipids and gangliosides were strongly modulated by either OUA or LPS treatments. LPS reduced the total phospholipids (roughly 23 %) and increased the total gangliosides (approximately 40 %). OUA alone increased the total phospholipids (around 23 %) and also the total gangliosides (nearly 34 %). OUA pretreatment compensated the LPS-induced changes, preserving the total phospholipids and gangliosides around the same levels of the control. Thus, an acute treatment with OUA not only modulated the composition of hippocampal membranes from 3-month-old rats, but also was apparently able to counteract membrane alterations resulting from LPS-induced neuroinflammation. This study demonstrates for the first time that the OUA capacity modulates the lipid composition of hippocampal plasma membranes from rats with LPS-induced neuroinflammation.

  4. Chemically produced tungsten–praseodymium oxide composite sintered by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xiao-Yu [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Lai-Ma, E-mail: luolaima@126.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Engineering Research Center of Powder Metallurgy of Anhui Province, Hefei 230009 (China); Lu, Ze-Long [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Luo, Guang-Nan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhu, Xiao-Yong; Cheng, Ji-Gui; Wu, Yu-Cheng [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Engineering Research Center of Powder Metallurgy of Anhui Province, Hefei 230009 (China)

    2014-11-15

    Highlights: • Wet chemical method was used to prepare highly uniform Pr{sub 2}O{sub 3} doped W–Pr{sub 2}O{sub 3} powder. • The Pr{sub 2}O{sub 3} particles significantly refine the grain size of tungsten alloy. • The tensile strength of Pr{sub 2}O{sub 3}/W samples were higher than those of pure W samples. - Abstract: Pr{sub 2}O{sub 3} doped W composite were synthesized by a novel wet chemical method and spark plasma sintering. The grain size, relative density and the Vicker hardness HV{sub 0.2} of Pr{sub 2}O{sub 3}/W samples were 4 μm, 98.3% and 377.2, respectively. The tensile strength values of Pr{sub 2}O{sub 3}/W were higher than those of pure W. As the temperature rises from 25 °C to 800 °C, the conductivity of pure W and W–1 wt% Pr{sub 2}O{sub 3} composites decreased with the same trend, was above 150 W/m K.

  5. Composition of highly concentrated silicate electrolytes and ultrasound influencing the plasma electrolytic oxidation of magnesium

    Science.gov (United States)

    Simchen, F.; Rymer, L.-M.; Sieber, M.; Lampke, T.

    2017-03-01

    Magnesium and its alloys are increasingly in use as lightweight construction materials. However, their inappropriate corrosion and wear resistance often prevent their direct practical use. The plasma electrolytic oxidation (PEO) is a promising, environmentally friendly method to improve the surface characteristics of magnesium materials by the formation of oxide coatings. These PEO layers contain components of the applied electrolyte and can be shifted in their composition by increasing the concentration of the electrolyte constituents. Therefore, in contrast to the use of conventional low concentrated electrolytes, the process results in more stable protective coatings, in which electrolyte species are the dominating constitutes. In the present work, the influence of the composition of highly concentrated alkaline silicate electrolytes with additives of phosphate and glycerol on the quality of PEO layers on the magnesium alloy AZ31 was examined. The effect of ultrasound coupled into the electrolyte bath was also considered. The process was monitored by recording the electrical process variables with a transient recorder and by observation of the discharge phenomena on the sample surface with a camera. The study was conducted on the basis of a design of experiments. The effects of the process parameter variation are considered with regard to the coatings thickness, hardness and corrosion resistance. Information about the statistical significance of the effects of the parameters on the considered properties is obtained by an analysis of variance (ANOVA).

  6. Phase Composition, Microstructure, and Tribological Property of Plasma-Sprayed TiC-BASED Coating

    Science.gov (United States)

    Sun, Shibin; Zou, Zengda; Liu, Xuemei; Shi, Hanchao

    TiC-based wear resistant coating was prepared by plasma spraying using reconstituted composite powders doped with ultra-fine carbide. Phase composition and microstructure of as-sprayed coating were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) utilizing backscattered imaging mode (BSE), and electron probe micro-analysis. Wear test was performed by using a ring-on-block tester under dry sliding condition. Results show that the coating adheres well to the substrate and no delamination appears. TiC content underwent pronounced reduction because of oxidation, reaction, and physical loss. Reactions between TiC and Mo and probably between dissociated C and Mo lead to the formation of Mo2C. Wear resistance of NiCrMo-TiC coating is about 4-8 times higher than that of substrate under different applied force. This work shed light on the reconstitution of spraying powder doped with ultra-fine reinforce phase particles, and the present results are important for the preparation of nano-doped TiC-based coatings.

  7. Application of a novel plasma-induced CD/MWCNT/iron oxide composite in zinc decontamination.

    Science.gov (United States)

    Yang, Shitong; Guo, Zhiqiang; Sheng, Guodong; Wang, Xiangke

    2012-10-01

    Herein, β-cyclodextrin (β-CD) was grafted onto magnetic MWCNT/iron oxide particles by using low temperature plasma-induced technique to synthesize a novel nanocomposite. The prepared composite (denoted as CD/MWCNT/iron oxide) exhibited high magnetic property (saturation magnetization M(s)=37.8 emu/g) and good dispersion property in aqueous solution. Batch experiments were conducted to evaluate the application potential of CD/MWCNT/iron oxide in the decontamination of Zn(II) from aqueous solutions. The sorption amount of Zn(II) on CD/MWCNT/iron oxide was higher than that of Zn(II) on MWCNT/iron oxides and oxidized MWCNTs, indicating that the grafted β-CD could enhance the sorption capacity of CD/MWCNT/iron oxide composite toward Zn(II) by providing multiple hydroxyl functional groups. Due to its high magnetic, CD/MWCNT/iron oxide could be easily separated from aqueous solution with an external magnetic field. Regeneration studies suggested that CD/MWCNT/iron oxide can support long term use as a cost-effective material in sewage treatment with minimum replacement costs.

  8. Measuring time-dependent diffusion in polymer matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Pilli, Siva Prasad; Smith, Lloyd V.; Shutthanandan, V.

    2014-11-01

    Moisture plays a significant role in influencing the mechanical behavior and long-term durability of polymer matrix composites (PMC’s). The common methods used to determine the moisture diffusion coefficients of PMCs are based on the solution of Fickian diffusion in the one-dimensional domain. Fick’s Law assumes that equilibrium between the material surface and the external vapor is established instantaneously. A time dependent boundary condition has been shown to improve correlation with some bulk diffusion measurements, but has not been validated experimentally. The surface moisture content in a Toray 800S/3900-2B toughened quasi-isotropic laminate system, [0/±60]s, was analyzed experimentally using Nuclear Reaction Analysis (NRA). It was found that the surface moisture content showed a rapid increase to an intermediate concentration C0, followed by a slow linear increase to the saturation level.

  9. Spark plasma sintering of silicon carbide and multi-walled carbon nanotube reinforced zirconium diboride ceramic composite

    Energy Technology Data Exchange (ETDEWEB)

    Yadhukulakrishnan, Govindaraajan B.; Rahman, Arif; Karumuri, Sriharsha [School of Mechanical and Aerospace Engineering Oklahoma State University, Stillwater, OK 74078 (United States); Stackpoole, Margaret M. [ELORET Corporation, Moffett Field, CA 94035 (United States); Kalkan, A. Kaan; Singh, Raman P. [School of Mechanical and Aerospace Engineering Oklahoma State University, Stillwater, OK 74078 (United States); Harimkar, Sandip P., E-mail: sandip.harimkar@okstate.edu [School of Mechanical and Aerospace Engineering Oklahoma State University, Stillwater, OK 74078 (United States)

    2012-08-30

    Highlights: Black-Right-Pointing-Pointer Dense SiC and carbon nanotube reinforced ZrB{sub 2} composites were spark plasma sintered. Black-Right-Pointing-Pointer SiC and carbon nanotube reinforcement favored the densification of ZrB{sub 2} composites. Black-Right-Pointing-Pointer SiC and carbon nanotube reinforcement resulted in toughening of ZrB{sub 2} composites. Black-Right-Pointing-Pointer Carbon nanotubes were retained in the spark plasma sintered ZrB{sub 2} composites. - Abstract: In this paper spark plasma sintering (SPS) of silicon carbide and multi-walled carbon nanotube reinforced zirconium diboride ultra-high temperature ceramic matrix composites is reported. Systematic investigations on the effect of reinforcement type (SiC and CNTs) and content (10-40 vol.% SiC and 2-6 vol.% CNTs) on densification behavior, microstructure development, and mechanical properties (microhardness, bi-axial flexural strength, and indentation fracture toughness) are presented. With the similar SPS processing parameters (1900 Degree-Sign C, 70 MPa pressure, and 15 min soaking time), near-full densification (>99% relative density) was achieved with 10-40% SiC (in ZrB{sub 2}-SiC) and 4-6% CNT (in ZrB{sub 2}-CNT) reinforced composites. The SiC and CNT reinforcement further improved the indentation fracture toughness of the composites through a range of toughening mechanisms, including particle shearing, crack deflection at the particle-matrix interface, and grain pull-outs for ZrB{sub 2}-SiC composites, and CNT pull-outs and crack deflection in ZrB{sub 2}-CNT composites.

  10. Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

    Science.gov (United States)

    Yau, A. W.; Whalen, B. A.; Harris, F. R.; Gattinger, R. L.; Pongratz, M. B.

    1985-01-01

    Observations of plasma depletion, ion composition modification, and airglow emissions in the Waterhole experiments are presented. The detailed ion chemistry and airglow emission processes related to the ionospheric hole formation in the experiment are examined, and observations are compared with computer simulation results. The latter indicate that the overall depletion rates in different parts of the depletion region are governed by different parameters.

  11. Conversion of FAD to FMN and riboflavin in plasma: effects of measuring method.

    Science.gov (United States)

    Akimoto, Masayuki; Sato, Yuko; Okubo, Toshimi; Todo, Hiroaki; Hasegawa, Tetsuya; Sugibayashi, Kenji

    2006-08-01

    The stability of flavin adenin dinucleotide (FAD) in plasma was studied under a low-intensity light and FAD was found to be converted to flavin mononucleotide (FMN) and riboflavin (RF) in both human and rat plasma. The hydrolysis rates of FAD in plasma at 4 degrees C were lower than those at 37 degrees C. In addition, the hydrolysis rates were markedly inhibited when EDTA, known as an anticoagulant, was added to plasma. These results indicated that plasma samples in pharmacokinetic studies should be pretreated with EDTA, extracted at the earliest convenience and lower temperature like 4 degrees C to keep a high stability. The pharmacokinetic study after intravenous administration of FAD at a dose of 500 nmol/kg as FAD in rats was performed with plasma samples after addition of EDTA under strict light and temperature control. A measurable amount of FAD in plasma together with rapid conversions of FAD to FMN and RF were observed in rat plasma. The AUC values (mean+/-S.D. of 4 rats) for FAD, FMN and RF were 707+/-378, 3643+/-958 and 30095+/-3544 nmol x min/l, respectively. Using excess EDTA under strict temperature and light control may be useful for assessment of vitamin B2 in the in vivo study.

  12. First results from the plasma composition spectrometer PROMICS-3 in the Interball project

    OpenAIRE

    Sandahl, I.; S. Barabash; Borg, H.; Budnik, E. Yu.; Dubinin, E. M.; Eklund, U.; Johansson, H.; H. Koskinen; K. Lundin; Lundin, R.; Moström, A.; Pellinen, R.; Pissarenko, N. F.; Pulkkinen, T.; Toivanen, P.

    1997-01-01

    International audience; PROMICS-3 is a plasma experiment flown in the Russian project Interball. It performs three-dimensional (3D) measurements of ions in the energy range 4 eV?70 keV with mass separation and of electrons in the energy range 12 eV?35 keV. The Interball project consists of two main satellites, the Tail Probe and the Auroral Probe, each with one subsatellite. The Interball Tail Probe was launched on 3 August 1995, into a 65° inclination orbit with apogee at about 30 RE. Both m...

  13. Investigation of heavy ions diffusion under the influence of current-driven mechanism and compositional waves in plasma

    CERN Document Server

    Urpin, Vadim

    2016-01-01

    We consider diffusion caused by a combined influence of the Hall effect and electric currents, and argue that such diffusion forms chemical inhomogeneities in plasma. The considered mechanism can be responsible for the formation of element spots in laboratory and astrophysical plasmas. Such current-driven diffusion can be accompanied by the propagation of a particular type of waves which have not been considered earlier. In these waves, the impurity number density oscillare alone and their frequency is determined by the electric currents and sort of impurity ions. These compositional waves exist if the magnetic pressure in plasma is much greater than the gas pressure. Such waves lead to local variations of chemical composition and, hence, can manifest themselves by variations of the emission in spectral lines.

  14. Studies of plasma breakdown and electron heating on a 14 GHz ECR ion source through measurement of plasma bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Ropponen, T; Machicoane, G; Leitner, D [National Superconducting Cyclotron Laboratory, MSU, East Lansing, MI 48824 (United States); Tarvainen, O; Toivanen, V; Koivisto, H; Kalvas, T; Peura, P; Jones, P [University of Jyvaeskylae, Department of Physics, PO Box 35 (YFL), 40500 Jyvaeskylae (Finland); Izotov, I; Skalyga, V; Zorin, V [Institute of Applied Physics, RAS, 46 Ulyanov St., 603950 Nizhny Novgorod (Russian Federation); Noland, J, E-mail: tommi.ropponen@gmail.com, E-mail: olli.tarvainen@jyu.fi [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2011-10-15

    Temporal evolution of plasma bremsstrahlung emitted by a 14 GHz electron cyclotron resonance ion source (ECRIS) operated in pulsed mode is presented in the energy range 1.5-400 keV with 100 {mu}s resolution. Such a high temporal resolution together with this energy range has never been measured before with an ECRIS. Data are presented as a function of microwave power, neutral gas pressure, magnetic field configuration and seed electron density. The saturation time of the bremsstrahlung count rate is almost independent of the photon energy up to 100 keV and exhibits similar characteristics with the neutral gas balance. The average photon energy during the plasma breakdown is significantly higher than that during the steady state and depends strongly on the density of seed electrons. The results are consistent with a theoretical model describing the evolution of the electron energy distribution function during the preglow transient.

  15. Platelets confound the measurement of extracellular miRNA in archived plasma.

    Science.gov (United States)

    Mitchell, Adam J; Gray, Warren D; Hayek, Salim S; Ko, Yi-An; Thomas, Sheena; Rooney, Kim; Awad, Mosaab; Roback, John D; Quyyumi, Arshed; Searles, Charles D

    2016-09-13

    Extracellular miRNAs are detectable in biofluids and represent a novel class of disease biomarker. Although many studies have utilized archived plasma for miRNA biomarker discovery, the effects of processing and storage have not been rigorously studied. Previous reports have suggested plasma samples are commonly contaminated by platelets, significantly confounding the measurement of extracellular miRNA, which was thought to be easily addressed by additional post-thaw plasma processing. In a case-control study of archived plasma, we noted a significant correlation between miRNA levels and platelet counts despite post-thaw processing. We thus examined the effects of a single freeze/thaw cycle on microparticles (MPs) and miRNA levels, and show that a single freeze/thaw cycle of plasma dramatically increases the number of platelet-derived MPs, contaminates the extracellular miRNA pool, and profoundly affects the levels of miRNAs detected. The measurement of extracellular miRNAs in archived samples is critically dependent on the removal of residual platelets prior to freezing plasma samples. Many previous clinical studies of extracellular miRNA in archived plasma should be interpreted with caution and future studies should avoid the effects of platelet contamination.

  16. Plasma flow velocity measurements using a modulated Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J. [Australian National Univ., Canberra, ACT (Australia). Plasma Research Lab.; Meijer, F.G. [FOM-Instituut voor Plasmafysica `Rijnhuizen`, Association Euratom-FOM, PO Box 1207, 3430 BE Nieuwegein (Netherlands)]|[Physics Faculty, University of Amsterdam, Amsterdam (Netherlands)

    1997-03-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.) 1 refs.

  17. A Catalytic Sensor for Measurement of Radical Density in CO2 Plasmas

    Directory of Open Access Journals (Sweden)

    Alenka Vesel

    2012-11-01

    Full Text Available A catalytic sensor for the measurement of radical density in weakly ionized CO2 plasmas, created in a low-pressure electrodeless discharge, is presented. The CO2 plasma was created in a 4 cm wide borosilicate glass tube inside a copper coil connected to a radio frequency generator operating at 27.12 MHz with a nominal power of 250 W. The dissociation fraction of the CO2 molecules was measured in the early afterglow at pressures ranging from 10 Pa to 100 Pa, and at distances of up to 35 cm along the gas stream from the glowing plasma. The radical density peaked (2 × 1020 m–3 at 80 Pa. The density quickly decreased with increasing distance from the glowing plasma despite a rather large drift velocity. The dissociation fraction showed similar behavior, except that the maximum was obtained at somewhat lower pressure. The results were explained by rather intense surface recombination of radicals.

  18. Microwave frequency sweep interferometer for plasma density measurements in ECR ion sources: Design and preliminary results

    Science.gov (United States)

    Torrisi, Giuseppe; Mascali, David; Neri, Lorenzo; Leonardi, Ornella; Sorbello, Gino; Celona, Luigi; Castro, Giuseppe; Agnello, Riccardo; Caruso, Antonio; Passarello, Santi; Longhitano, Alberto; Isernia, Tommaso; Gammino, Santo

    2016-02-01

    The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma density measurement in hostile environment. Interferometry in ECRISs is a challenging task mainly due to their compact size. The typical density of ECR plasmas is in the range 1011-1013 cm-3 and it needs a probing beam wavelength of the order of few centimetres, comparable to the chamber radius. The paper describes the design of a microwave interferometer developed at the LNS-INFN laboratories based on the so-called "frequency sweep" method to filter out the multipath contribution in the detected signals. The measurement technique and the preliminary results (calibration) obtained during the experimental tests will be presented.

  19. Microwave frequency sweep interferometer for plasma density measurements in ECR ion sources: Design and preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, Giuseppe [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); University Mediterranea of Reggio Calabria, Reggio Calabria (Italy); Mascali, David; Neri, Lorenzo; Leonardi, Ornella; Celona, Luigi; Castro, Giuseppe; Agnello, Riccardo; Caruso, Antonio; Passarello, Santi; Longhitano, Alberto; Gammino, Santo [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Sorbello, Gino [INFN - Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); University of Catania, Catania, Italy and INFN-LNS, Catania (Italy); Isernia, Tommaso [University Mediterranea of Reggio Calabria, Reggio Calabria (Italy)

    2016-02-15

    The Electron Cyclotron Resonance Ion Sources (ECRISs) development is strictly related to the availability of new diagnostic tools, as the existing ones are not adequate to such compact machines and to their plasma characteristics. Microwave interferometry is a non-invasive method for plasma diagnostics and represents the best candidate for plasma density measurement in hostile environment. Interferometry in ECRISs is a challenging task mainly due to their compact size. The typical density of ECR plasmas is in the range 10{sup 11}–10{sup 13} cm{sup −3} and it needs a probing beam wavelength of the order of few centimetres, comparable to the chamber radius. The paper describes the design of a microwave interferometer developed at the LNS-INFN laboratories based on the so-called “frequency sweep” method to filter out the multipath contribution in the detected signals. The measurement technique and the preliminary results (calibration) obtained during the experimental tests will be presented.

  20. Measurements of egg shell plasma parameters using laser-induced breakdown spectroscopy

    Indian Academy of Sciences (India)

    Wenfeng Luo; Xiaoxia Zhao; Shuyuan Lv; Haiyan Zhu

    2015-07-01

    Measurements of 1064 nm laser-induced egg shell plasma parameters are presented in this paper. Of special interests were its elemental identification and the determination of spectroscopic temperature and electron density. The electron temperature of 5956 K was inferred using an improved iterative Boltzmann plot method with six calcium atomic emission lines, and the electron number density of 6.1 × 1016 cm−3 was determined by measuring the width of Stark-broadened once-ionized calcium line at 393.37 nm. Based on the experimental results, the laser-induced egg shell plasma was verified to be optically thin and satisfy local thermodynamic equilibrium (LTE). Furthermore, experiments also demonstrated that the loss of energy due to the reflection of the laser beam from the plasma can be neglected and the inverse bremsstrahlung (IB) absorption was the dominant mechanism of plasma heating at the IR wavelength.

  1. Edge and divertor plasma measurements with ion sensitive and Mach probes in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y., E-mail: shihaya_uki884@yahoo.co.jp [Nagano National College of Technology, 716 Tokuma, Nagano 381-8550 (Japan); Ezumi, N. [Nagano National College of Technology, 716 Tokuma, Nagano 381-8550 (Japan); Masuzaki, S.; Tanaka, H.; Kobayashi, M. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Sawada, K. [Shinshu University, Wakasato, Nagano 380-8553 (Japan); Ohno, N. [Nagoya University, Furo-cho Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-07-15

    Spatial profiles of plasma flow and Mach number in the stochastic magnetic boundary layer as well as ion temperature (T{sub i}) and electron temperature (T{sub e}) in the divertor region in Large Helical Device (LHD) have been studied by a movable multiple functions probe, which consists of Mach probes and an ion sensitive probe. The results of ion saturation current measurements indicated plasma flow direction is alternated in the stochastic magnetic boundary. Mach number profiles for different plasma densities have been evaluated experimentally which compared with 3-D transport code. T{sub i} and T{sub e} in the divertor region measured by the ion sensitive probe decreased with increasing line-averaged density. Although T{sub i} was higher than T{sub e} in the low density plasma, both temperatures became almost the same at higher density.

  2. Simultaneous Measurements of Electrostatic and Magnetic Fluctuations in ASDEX Upgrade Edge Plasma

    DEFF Research Database (Denmark)

    Ionita, Codrina; Vianello, Nicola; Müller, H.W.

    2009-01-01

    in such a way that simultaneously the poloidal and radial electric field components, the ion saturation current and the current-voltage characteristic can be registered. During the AUG discharges of 7 s lengths the probe head is inserted two to three times for 100 ms each by the midplane manipulator......In ASDEX Upgrade (AUG) electrostatic and magnetic fluctuations in the edge plasma region were measured simultaneously during ELMy H-mode (high confinement) plasmas and L-mode (low confinement) plasmas and during a transition between the two modes. A special probe was used containing six Langmuir...

  3. Derivation of stochastic differential equations for scrape-off layer plasma fluctuations from experimentally measured statistics

    Energy Technology Data Exchange (ETDEWEB)

    Mekkaoui, A. [Institute for Energy and Climate Research-Plasma Physics, Research Center Juelich GmbH, Association FZJ-Euratom, D-52425 Juelich (Germany)

    2013-01-15

    A stochastic differential equation for intermittent plasma density dynamics in magnetic fusion edge plasma is derived, which is consistent with the experimentally measured gamma distribution and the theoretically expected quadratic nonlinearity. The plasma density is driven by a multiplicative Wiener process and evolves on the turbulence correlation time scale, while the linear growth is quadratically damped by the fluctuation level. The sensitivity of intermittency to the nonlinear dynamics is investigated by analyzing the nonlinear Langevin representation of the beta process, which leads to a root-square nonlinearity.

  4. Electronically swept millimeter-wave interferometer for spatially resolved measurement of plasma electron density.

    Science.gov (United States)

    Howard, John; Oliver, David

    2006-12-01

    We report the development and initial implementation of what we believe to be a new rapid- spatial-scan millimeter-wave interferometer for plasma density measurements. The fast scan is effected by electronic frequency sweeping of a wideband (180-280 GHz) backward-wave oscillator whose output is focused onto a fixed blazed diffraction grating. The system, which augments the rotating-grating scanned multiview H-1 heliac interferometer, can sweep the plasma cross section in a period of less than 1 ms with a beam diameter in the plasma of 20 mm and phase noise of the order of 0.01 rad.

  5. [Designing and implementation of a web-based quality monitoring system for plasma glucose measurement in multicenter population study].

    Science.gov (United States)

    Liu, Yong; Wang, Limin; Pang, Richard; Mo, Nanxun; Hu, Yan; Deng, Qian; Hu, Zhaohui

    2015-05-01

    The aim of this paper is to describe the designing and implementation of a web-based plasma glucose measurement quality monitoring system to assess the analytical quality of plasma glucose measurements in multicenter population study and provide evidence for the future studies. In the chronic non-communicable disease and related factor surveillance in China, a web based quality monitoring system for plasma glucose measurement was established to conduct evaluation on plasma glucose monitoring quality and effectiveness in 302 surveillance centers, including quality control data entry, transmission and feedback. The majority of the surveillance centers met the quality requirements and passed the evaluation of reproducibility and precision of plasma glucose measurement, only a few centers required intensive training and re-assessment. In order to ensure the completeness and reliability of plasma glucose measurement in the surveillance centers, the establishment of web-based plasma glucose measurement quality control system can facilitate the identification of the qualified surveillance centers and evaluation of plasma glucose measurement quality in different regions. Communication and training are important in ensuring plasma glucose measurement quality. It is necessary to further improve this web-based plasma glucose measurement quality monitoring system in the future to reduce the method specific plasma glucose measurement bias.

  6. Schottky barrier height of Ni to β-(AlxGa1‑x)2O3 with different compositions grown by plasma-assisted molecular beam epitaxy

    Science.gov (United States)

    Ahmadi, Elaheh; Oshima, Yuichi; Wu, Feng; Speck, James S.

    2017-03-01

    Coherent β-(AlxGa1‑x)2O3 films (x = 0, 0.038, 0.084, 0.164) were grown successfully on a Sn-doped β-Ga2O3 (010) substrate using plasma-assisted molecular beam epitaxy. Atom probe tomography, transmission electron microscopy, and high resolution x-ray diffraction were used to verify the alloy composition and high quality of the films. Schottky diodes were then fabricated using Ni as the Schottky metal. Capacitance–voltage measurements revealed a very low (current–voltage (I–V) measurements performed at temperatures varying from 300 K to 500 K on the Schottky diodes. These measurements revealed that the apparent Schottky barrier height could have similar values for different compositions of β-(AlxGa1‑x)2O3. We believe this is attributed to the lateral fluctuation in the alloy’s composition. This results in a lateral variation in the barrier height. Therefore, the average Schottky barrier height extracted from I–V measurements could be similar for β-(AlxGa1‑x)2O3 films with different compositions.

  7. Observation of spectral composition and polarization of sub-terahertz emission from dense plasma during relativistic electron beam–plasma interaction

    Energy Technology Data Exchange (ETDEWEB)

    Arzhannikov, A. V.; Burmasov, V. S.; Ivanov, I. A.; Kuznetsov, S. A.; Postupaev, V. V.; Sinitsky, S. L.; Vyacheslavov, L. N. [Budker Institute of Nuclear Physics, 11 Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090 (Russian Federation); Burdakov, A. V. [Budker Institute of Nuclear Physics, 11 Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20 Karl Marks Ave., Novosibirsk 630092 (Russian Federation); Gavrilenko, D. E.; Kasatov, A. A.; Mekler, K. I.; Rovenskikh, A. F. [Budker Institute of Nuclear Physics, 11 Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Polosatkin, S. V.; Sklyarov, V. F. [Budker Institute of Nuclear Physics, 11 Lavrentiev Ave., Novosibirsk 630090 (Russian Federation); Novosibirsk State University, 2 Pirogova St., Novosibirsk 630090 (Russian Federation); Novosibirsk State Technical University, 20 Karl Marks Ave., Novosibirsk 630092 (Russian Federation)

    2014-08-15

    The paper presents results of measurements of sub-terahertz electromagnetic emission from magnetized plasma during injection of a powerful relativistic electron beam of microsecond duration in plasma with the density of 3 × 10{sup 14 }cm{sup −3}. It was found that the spectrum of the radiation concentrated in three distinct regions with high level of spectral power density. The first region is located near f{sub 1} = 100 GHz; the second one is in the vicinity of 190 GHz, and the third region is in the frequency interval f{sub 3} = 280–340 GHz. Polarization vectors of the emission in the first and third regions (f{sub 1} and f{sub 3}) are directed mainly perpendicular to the magnetic field in the plasma. At the same time, the polarization of the radiation in the vicinity of f{sub 2} = 190 GHz is parallel to the magnetic field. The most likely mechanism of electromagnetic wave generation in the frequency regions f{sub 1} and f{sub 2} is the linear conversion of the plasma oscillations into the electromagnetic waves on strong gradients of the plasma density. The third region is situated in the vicinity of second harmonic of electron plasma frequency, and we explain this emission by the coalescence of the upper-hybrid oscillations at high level turbulence in plasma.

  8. FORMATION AND RESEARCH OF MULTI-LAYER COMPOSITE PLASMA OXIDE COATINGS BASED ON ELEMENTS OF SCREEN METEROID PTOTECTION

    Directory of Open Access Journals (Sweden)

    V. A. Okovity

    2016-01-01

    Full Text Available The paper presents results of research for influence of plasma jet parameters (current, spraying distance, plasmasupporting nitrogen gas consumption, fractional composition of an initial powder and cooling degree by compressed air on characteristics of anti-meteorite coatings, subsequent processing modes by pulsed plasma. Properties of the obtained coatings and results of ballistic tests have been given in the paper. The proposed methodology has been based on complex metallographic, X-ray diffraction and electron microscopic investigations of anti-meteorite aluminum oxide coating. Optimization of air plasma spraying parameters for NiAl and Al2O3 materials has been carried out in the paper. The spraying parameters optimization has been executed on the basis of obtaining maximum materials utilization factor. Surface treatment of model screen elements with a double-layer composite coating (adhesive metal NiAl layer and hard ceramic oxide Al2O3 layer has been fulfilled while using compression plasma stream. Nitrogen has been used as working gas. Composite hard ceramic oxide Al2O3 coating is represented by porous structure consisting of 10–15 µm-size fused Al2O3 particles. Metallic inclusions formed due to erosion of plasmatron electrodes have been observed in the space between the particles. Surface of bilayer composite coatings has been processed by a compression plasma stream and due to nonsteady processes of melting and recrystallization high strength polycrystalline layer has been formed on their surface. In this context, those areas of the polycrystalline layer which had metal inclusions have appeared to be painted in various colors depending on chemical composition of the inclusions.

  9. Effects of surface modification by atmospheric oxygen dielectric barrier discharge plasma on PBO fibers and its composites

    Science.gov (United States)

    Liu, Zhe; Chen, Ping; Zhang, Xiaoliang; Yu, Qi; Ma, Keming; Ding, Zhenfeng

    2013-10-01

    In this paper, oxygen dielectric barrier discharge (oxy-DBD) plasma was employed to modify PBO fibers and enhance the interfacial adhesion of PBO fiber/bismaleimide composites. The interlaminar shear strength (ILSS) of the composites was improved greatly to 62.0 MPa with an increment of 41.2% at 30 W/cm3, 24 s. The SEM images of fracture morphology indicated that the failure place shifted from the interface to the matrix, and the water absorption decreased from 1.96 to 1.53%, the two results demonstrated the improved adhesive strength in other ways. In addition, the ILSS retention ratio of PBO/BMI composites after boiling in water were about 90%, confirming good humid resistance of the composites. The results obtained from XPS and AFM revealed that some polar groups were introduced onto PBO fibers and the surface morphology of PBO fibers was roughened. As a result, the wettability, reactivity and roughness of PBO fibers were all improved, they contributed to the improvement of the ILSS of the composites. The comparisons with air-DBD plasma showed that the chemical changes of PBO fibers were not alike because of different plasma gases.

  10. Microstructure and Corrosion Resistance of Cr7C3/γ-Fe Ceramal Composite Coating Fabricated by Plasma Cladding

    Institute of Scientific and Technical Information of China (English)

    LIU Junbo

    2007-01-01

    A new type in situ Cr7C3/γ-Fe ceramal composite coating was fabricated on substrate of hardened and tempered grade C steel by plasma cladding with Fe-Cr-C alloy powders. The ceramal composite coating has a rapidly solidified microstructure consisting of primary Cr7C3 and the Cr7C3/γ-Fe eutectics, and is metallurgically bonded to the degree C steel substrate. The corrosion resistances of the coating in water solutions of 0.5 mol/L H2SO4 and 3.5% NaCl were evaluated utilizing the electrochemical polarization corrosion-test method. Because of the inherent excellent corrosion-resisting properties of the constituting phase and the rapidly solidified homogeneous microstructure, the plasma clad ceramal composite coating exhibits excellent corrosion resistance in the water solutions of 0.5 mol/L H2SO4 and 3.5% NaCl.

  11. Cross-diagnostic comparison of fluctuation measurements in a linear plasma column

    Science.gov (United States)

    Light, Adam D.; Archer, Nicholas A. A.; Bashyal, Atit; Chakraborty Thakur, Saikat; Tynan, George R.

    2015-11-01

    The advent of fast imaging diagnostics, which provide two-dimensional measurements on relevant plasma time scales, has proven invaluable for interpreting plasma dynamics in laboratory devices. Despite its success, imaging remains a qualitative aid for many studies, because intensity is difficult to map onto a single physical variable for use in a theoretical model. This work continues our exploration of the relationship between visible-light and electrostatic probe measurements in the Controlled Shear Decorrelation Experiment (CSDX). CSDX is a well-characterized linear machine producing dense plasmas relevant to the tokamak edge (Te ~ 3 eV, ne ~1013 /cc). Visible light from ArI and ArII line emission is collected at high frame rates using a fast digital camera. Floating potential and ion-saturation current are measured by an array of electrostatic probe tips. We present a detailed comparison between imaging and probe measurements of fluctuations, including temporal, spatial, and spectral properties in various operational regimes.

  12. A Fiber Optic Catalytic Sensor for Neutral Atom Measurements in Oxygen Plasma

    Directory of Open Access Journals (Sweden)

    Alenka Vesel

    2012-03-01

    Full Text Available The presented sensor for neutral oxygen atom measurement in oxygen plasma is a catalytic probe which uses fiber optics and infrared detection system to measure the gray body radiation of the catalyst. The density of neutral atoms can be determined from the temperature curve of the probe, because the catalyst is heated predominantly by the dissipation of energy caused by the heterogeneous surface recombination of neutral atoms. The advantages of this sensor are that it is simple, reliable, easy to use, noninvasive, quantitative and can be used in plasma discharge regions. By using different catalyst materials the sensor can also be applied for detection of neutral atoms in other plasmas. Sensor design, operation, example measurements and new measurement procedure for systematic characterization are presented.

  13. Measurement of Wave Electric Fields in Plasmas by Electro-Optic Probe

    CERN Document Server

    Nishiura, M; Mushiake, T; Kawazura, Y; Osawa, R; Fujinami, K; Yano, Y; Saitoh, H; Yamasaki, M; Kashyap, A; Takahashi, N; Nakatsuka, M; Fukuyama, A

    2016-01-01

    Electric field measurement in plasmas permits quantitative comparison between the experiment and the simulation in this study. An electro-optic (EO) sensor based on Pockels effect is demonstrated to measure wave electric fields in the laboratory magnetosphere of the RT-1 device with high frequency heating sources. This system gives the merits that electric field measurements can detect electrostatic waves separated clearly from wave magnetic fields, and that the sensor head is separated electrically from strong stray fields in circumference. The electromagnetic waves are excited at the double loop antenna for ion heating in electron cyclotron heated plasmas. In the air, the measured wave electric fields are in good absolute agreement with those predicted by the TASK/WF2 code. In inhomogeneous plasmas, the wave electric fields in the peripheral region are enhanced compared with the simulated electric fields. The potential oscillation of the antenna is one of the possible reason to explain the experimental resu...

  14. Spectral Measurement of Atmospheric Pressure Plasma by Means of Digital Camera

    Institute of Scientific and Technical Information of China (English)

    葛袁静; 张广秋; 刘益民; 赵志发

    2002-01-01

    A digital camera measuring system has been used successfully to measure the space fluctuation behaviors of Induced Dielectric Barrier Discharge (IDBD) plasma at atmospheric pressure. The experimental results showed that: (1) The uniformity of electron temperature in space depends on discharge condition and structure of web electrode. For a certain web electrode the higher the discharge voltage is, the more uniform distribution of electron temperature in space will be. For a certain discharge the finer and denser the holes on web electrode are, the more uniform distribution of electron temperature in space will be (2). Digital camera is an available equipment to measure some behaviors of the plasma working at atmospheric pressure.

  15. Relationship of Plasma IL-6 to the Metabolic Measures associated with Insulin Resistance due to Adiposity

    Institute of Scientific and Technical Information of China (English)

    Ryoyu Takeda; Isamu Miyamori; WU Pingsheng (吴平生); Yoshihiro Takayama; Yuji Ito; Takaharu Masunaga; Takahiro Zenda; Satoshi Asaka; Hisanori Oiwake; Kimihide Shinozaki; Yoshiyu Takeda

    2004-01-01

    Objectives To elucidate the relationship of plasma interleukin-6 (IL-6) to the metabolic measures associated with insulin resistance (IR) due to adiposity. Methods For a cross-sectional study, eighty normotensive men with and without obesity were enrolled consecutively in our health examination center. Fasting blood glucose (FBG), fasting plasma immunoreactive insulin (FIRI), HOMA-R (Homeostasis Model Assessment Insulin Resistance Index), plasma lipids (cholesterol, triglyceride, high density lipoprotein cholesterol), cortisol, dehydroepiandrosterone-sulfate (DHEA-S), interleukin-6 and C-reactive protein(CRP) were measured. Results Plasma levels of FIRI, triglyceride (TG), DHEA-S,CRP and HOMA-R were significantly higher in obese group with BMI over 25 than non-obese group,whereas HDL-C was significantly lower in obese group. BMI was positively correlated with FIRI, TG,hsCRP and HOMA-R, whereas negatively with HDLC. BMI was positively correlated with plasma DHEAS levels but not with cortisol. Plasma levels of IL-6 were positively correlated with FIRI, TG, CRP and HOMA-R but in a multiple regression analysis with IL-6, only HOMA-R and TG remained explainable variables. Conclusions Each of commonly used measures of inflammatory reaction, CRP and IL-6, showed a significantly positive correlation with either FIRI or HOMA-R, suggesting associations between subclinical inflammation and obesity as the risk of type 2 diabetes mellitus.

  16. Measurement of plasma histamine: description of an improved method and normal values

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, J.; Warren, K.; Merlin, S.; Metcalfe, D.D.; Kaliner, M.

    1982-08-01

    The single isotopic-enzymatic assay of histamine was modified to increase its sensitivity and to facilitate measurement of plasma histamine levels. The modification involved extracting /sup 3/H-1-methylhistamine (generated by the enzyme N-methyltransferase acting on histamine in the presence of S-(methyl-/sup 3/H)-adenosyl-L-methionine) into chloroform and isolating the /sup 3/H-1-methylhistamine by thin-layer chromatography (TLC). The TLC was developed in acetone:ammonium hydroxide (95:10), and the methylhistamine spot (Rf . 0.50) was identified with an o-phthalaldehyde spray, scraped from the plate, and assayed in a scintillation counter. The assay in plasma demonstrated a linear relationship from 200 to 5000 pg histamine/ml. Plasma always had higher readings than buffer, and dialysis of plasma returned these values to the same level as buffer, suggesting that the baseline elevations might be attributable to histamine. However, all histamine standard curves were run in dialyzed plasma to negate any additional influences plasma might exert on the assay. The arithmetic mean (+/- SEM) in normal plasma histamine was 318.4 +/- 25 pg/ml (n . 51), and the geometric mean was 280 +/- 35 pg/ml. Plasma histamine was significantly elevated by infusion of histamine at 0.05 to 1.0 micrograms/kg/min or by cold immersion of the hand of a cold-urticaria patient. Therefore this modified isotopic-enzymatic assay of histamine is extremely sensitive, capable of measuring fluctuations in plasma histamine levels within the normal range, and potentially useful in analysis of the role histamine plays in human physiology.

  17. Effect of sintering on the relative density of Cr-coated diamond/Cu composites prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    Wei Cui; Hui Xu; Jian-hao Chen; Shu-bin Ren; Xin-bo He; Xuan-hui Qu

    2016-01-01

    Cr-coated diamond/Cu composites were prepared by spark plasma sintering. The effects of sintering pressure, sintering tempera-ture, sintering duration, and Cu powder particle size on the relative density and thermal conductivity of the composites were investigated in this paper. The influence of these parameters on the properties and microstructures of the composites was also discussed. The results show that the relative density of Cr-coated diamond/Cu reaches ~100% when the composite is gradually compressed to 30 MPa during the heating process. The densification temperature increases from 880 to 915°C when the diamond content is increased from 45vol% to 60vol%. The densification temperature does not increase further when the content reaches 65vol%. Cu powder particles in larger size are beneficial for in-creasing the relative density of the composite.

  18. Plasma flow velocity measurements using a modulated Michelson interferometer

    NARCIS (Netherlands)

    Howard, J.; Meijer, F. G.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

  19. Breast composition measurements using retrospective standard mammogram form (SMF)

    Energy Technology Data Exchange (ETDEWEB)

    Highnam, R [Siemens Molecular Imaging Ltd, Hythe Bridge Street, Oxford (United Kingdom); Pan, X [Siemens Molecular Imaging Ltd, Hythe Bridge Street, Oxford (United Kingdom); Warren, R [Addenbrooke' s Hospital, Cambridge (United Kingdom); Jeffreys, M [Massey University, Wellington (New Zealand); Smith, G Davey [Clinical Epidemiology, University of Bristol (United Kingdom); Brady, M [Engineering Science, University of Oxford (United Kingdom)

    2006-06-07

    The standard mammogram form (SMF) representation of an x-ray mammogram is a standardized, quantitative representation of the breast from which the volume of non-fat tissue and breast density can be easily estimated, both of which are of significant interest in determining breast cancer risk. Previous theoretical analysis of SMF had suggested that a complete and substantial set of calibration data (such as mAs and kVp) would be needed to generate realistic breast composition measures and yet there are many interesting trials that have retrospectively collected images with no calibration data. The main contribution of this paper is to revisit our previous theoretical analysis of SMF with respect to errors in the calibration data and to show how and why that theoretical analysis did not match the results from the practical implementations of SMF. In particular, we show how by estimating breast thickness for every image we are, effectively, compensating for any errors in the calibration data. To illustrate our findings, the current implementation of SMF (version 2.2{beta}) was run over 4028 digitized film-screen mammograms taken from six sites over the years 1988-2002 with and without using the known calibration data. Results show that the SMF implementation running without any calibration data at all generates results which display a strong relationship with when running with a complete set of calibration data, and, most importantly, to an expert's visual assessment of breast composition using established techniques. SMF shows considerable promise in being of major use in large epidemiological studies related to breast cancer which require the automated analysis of large numbers of films from many years previously where little or no calibration data is available.

  20. Fast-acting calorimeter measures heat output of plasma gun accelerator

    Science.gov (United States)

    Dethlefson, R.; Larson, A. V.; Liebing, L.

    1967-01-01

    Calorimeter measures the exhaust energy from a shot of a pulsed plasma gun accelerator. It has a fast response time and requires only one measurement to determine the total energy. It uses a long ribbon of copper foil wound around a glass frame to form a reentrant cavity.

  1. IP-10 Can Be Measured in Dried Plasma Spots in Patients with Chronic Hepatitis C Infection

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Andersen, Ellen Sloth; Christensen, Peer Brehm;

    2012-01-01

    The chemokine IP-10 (CXCL10) is a candidate marker for hepatitis C virus (HCV) fibrosis monitoring. The aim of this proof-of-concept study is to assess if IP-10 measurements from dried plasma spots (DPS) are accurate in HCV-infected patients with either minimal or significant fibrosis. We measured...

  2. Assays to measure nanomolar levels of the renin inhibitor CGP 38 560 in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cumin, F.; de Gasparo, M.; Wood, J.M.; Schnell, C.; Frueh, F.; Graf, P. (Ciba-Geigy Limited, Basel (Switzerland))

    1989-10-01

    A radioinhibitor binding assay and an enzyme inhibition assay have been developed to measure plasma levels of CGP 38 560, a potent human renin inhibitor. The detection limit of the assays was between 0.5 and 1 pmol/ml. There was a good correlation (r = 0.989) between the two assays for the measurement of human plasma spiked with CGP 38 560 in concentrations from 1.9 nM to 12 microM. Intra-assay variability was 6.1-17.3% and 4.4-27.2% for the radioinhibitor binding assay and the enzyme inhibition assay, respectively. Interassay variability was 6.0-28.2% and 3.8-28.4% for the radioinhibitor binding assay and the enzyme inhibition assay, respectively. Blood samples were collected during a pharmacological study performed in normotensive human volunteers on an unrestricted diet who were infused during a 30-minute period with CGP 38 560 A (50 micrograms/kg). Similar values for the concentrations of renin inhibitor in plasma were obtained with the radioinhibitor binding assay and the enzyme inhibitor assay, and there was a significant correlation between values obtained with the two different methodologies (r = 0.94). The plasma levels of renin inhibitor reached a maximum at the end of infusion and then decreased rapidly, indicating a short plasma half-life. The changes in biochemical parameters, plasma renin activity, and plasma concentration of active renin could be related to the concentrations of CGP 38 560 measured in the plasma.

  3. Nitrogen metastable (N2(A3 Σu + )) in a cold argon atmospheric pressure plasma jet: Shielding and gas composition

    Science.gov (United States)

    Iseni, Sylvain; Bruggeman, Peter J.; Weltmann, Klaus-Dieter; Reuter, Stephan

    2016-05-01

    N 2 ( A 3 Σu + ) metastable species are detected and measured in a non-equilibrium atmospheric pressure plasma jet by laser induced fluorescence. A shielding device is used to change the ambient conditions additionally to the feeding gas composition. Varying the amount of N2 and air admixed to the feeding gas as well as changing the shielding gas from N2 to air reveals that the highest N 2 ( A 3 Σu + ) is achieved in the case of air admixtures in spite of the enhanced collisional quenching due to the presence of O2. The reasons for these observations are discussed in detail.

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

    Directory of Open Access Journals (Sweden)

    D. Hubert

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

  5. Numerical simulations based on probe measurements in EUV-induced hydrogen plasma

    Science.gov (United States)

    Abrikosov, Alex; Reshetnyak, Viktor; Astakhov, Dmitry; Dolgov, Alexandr; Yakushev, Oleg; Lopaev, Dmitry; Krivtsun, Vladimir

    2017-04-01

    We use the two-dimensional particle-in-cell model with Monte Carlo collisions to study the plasma induced in hydrogen by short pulses of extreme ultraviolet (EUV) radiation at wavelengths in the range 10–20 nm with a pulse duration of about 40 ns (FWHM). This plasma is formed via both photoionization by the high-energy EUV photons and by the secondary photoelectrons emitted from the hydrogen molecules and the irradiated surface. The latter process can be enhanced by the external electric field that accelerates the electrons. In order to establish a base for our model so as to obtain accurate results, we record a temporally-resolved series of current–voltage characteristics for a small probing electrode inserted into EUV-induced hydrogen plasma. We then resort to simulating this plasma in the same geometry with the probe in our model which we validate by matching its results to the experimentally measured dynamics of the probe current–voltage curves. Having validated the model this way, we use this model as an independent instrument capable of obtaining the spatiotemporal picture of EUV-induced plasma evolution. We use this instrument to study the plasma formation during the EUV pulse and point out the processes that take part in forming this plasma, such as impact ionization and direct ionization by EUV photons.

  6. SOL plasma measurements during high density and long duration current drive on TRIAM-1M

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, Takeharu; Kawasaki, Shoji; Jotaki, Eriko; Makino, Ken-ichi; Sakamoto, Mizuki; Nakamura, Kazuo; Nakamura, Yukio; Itoh, Sanae; Itoh, Satoshi [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1997-02-01

    In the superconducting, strong magnetic field tokamak, TRIAM-1M, for the purpose of maintaining high density plasma for long time, the current drive experiment using 8.2 GHz lower hybrid wave has been carried out. For maintaining high density plasma for long time, it is indispensable to control gas puff and recycling from wall, as these are closely related to the structure and characteristics of boundary plasma including scrape-off layer (SOL). In this study, in the high density, long time current drive using 8.2 GHz lower hybrid wave, the electron density and electron temperature of SOL plasma were measured by using double probe, and the z-direction distribution and the toroidal magnetic field dependence of the electron density and electron temperature of SOL plasma were examined and compared with OH discharge. Also the dependence of the electron density of SOL plasma on the phase difference in a adjoining waveguide tubes was examined. The experimental setup and the double probe theory are explained. The experimental results of the change with time lapse, the z-direction distribution and the magnetic field dependence of the electron density and electron temperature of SOL plasma are reported. (K.I.)

  7. Fish meal supplementation increases bovine plasma and luteal tissue omega-3 fatty acid composition.

    Science.gov (United States)

    White, N R; Burns, P D; Cheatham, R D; Romero, R M; Nozykowski, J P; Bruemmer, J E; Engle, T E

    2012-03-01

    The objective of this experiment was to determine if dietary inclusion of fish meal would increase plasma and luteal tissue concentrations of eicosapentaenoic and docosahexaenoic acids. Seventeen nonlactating Angus cows (2 to 8 yr of age) were housed in individual pens and fed a corn silage-based diet for approximately 60 d. Diets were supplemented with fish meal at 5% DMI (a rich source of eicosapentaenoic acid and docosahexaenoic acid; n = 9 cows) or corn gluten meal at 6% DMI (n = 8 cows). Body weights and jugular blood samples were collected immediately before the initiation of supplementation and every 7 d thereafter for 56 d to monitor plasma n-3 fatty acid composition and BW. Estrous cycles were synchronized using 2 injections of PGF(2α) administered at 14-d intervals. The ovary bearing the corpus luteum was surgically removed at midcycle (between d 10 and 12) after estrus synchronization, which corresponded to approximately d 60 of supplementation. The ovary was transported to the laboratory, and approximately 1.5 g of luteal tissue was stored at -80°C until analyzed for n-3 fatty acid content. Initial and ending BW did not differ (P > 0.10) between cows supplemented with fish meal and those with corn gluten meal. Plasma eicosapentaenoic acid was greater (P < 0.05) beginning at d 7 of supplementation and docosahexaenoic was greater (P < 0.05) beginning at d 14 of supplementation for cows receiving fish meal. Luteal tissue collected from fish meal-supplemented cows had greater (P < 0.05) luteal n-3 fatty acids and reduced (P < 0.05) arachidonic acid and n-6 to n-3 ratio as compared with tissue obtained from cows supplemented with corn gluten meal. Our data show that fish meal supplementation increases luteal n-3 fatty acid content and reduces available arachidonic acid content, the precursor for PGF(2α). The increase in luteal n-3 fatty acids may reduce PGF(2α) intraluteal synthesis after breeding resulting in increased fertility in cattle.

  8. Oxygen plasma flow properties deduced from laser-induced fluorescence and probe measurements

    Science.gov (United States)

    Löhle, Stefan; Eichhorn, Christoph; Steinbeck, Andreas; Lein, Sebastian; Herdrich, Georg; Röser, Hans-Peter; Auweter-Kurtz, Monika

    2008-04-01

    Estimation of the local dissociation degree and the local mass-specific enthalpy of a pure oxygen plasma flow determined mainly from laser-induced fluorescence measurements are reported. Measurements have been conducted for several generator parameters in an inductively heated plasma wind tunnel. Additional probe measurements of total pressure together with the deduced translational temperature are used to estimate the local mass-specific enthalpy. For a reference condition, full dissociation has been measured. The measured translational temperature of atomic oxygen for this condition is T = 3500 K. Subsequently, the local mass-specific enthalpy has been derived using these local density and temperature measurements. For the reference condition the estimated value of h = 27 MJ/kg is in good agreement with the probe measurements and results from diode laser absorption spectroscopy.

  9. Thermal Conductivity and Erosion Durability of Composite Two-Phase Air Plasma Sprayed Thermal Barrier Coatings

    Science.gov (United States)

    Schmitt, Michael P.; Rai, Amarendra K.; Zhu, Dongming; Dorfman, Mitchell R.; Wolfe, Douglas E.

    2015-01-01

    To enhance efficiency of gas turbines, new thermal barrier coatings (TBCs) must be designed which improve upon the thermal stability limit of 7 wt% yttria stabilized zirconia (7YSZ), approximately 1200 C. This tenant has led to the development of new TBC materials and microstructures capable of improved high temperature performance. This study focused on increasing the erosion durability of cubic zirconia based TBCs, traditionally less durable than the metastable t' zirconia based TBCs. Composite TBC microstructures composed of a low thermal conductivity/high temperature stable cubic Low-k matrix phase and a durable t' Low-k secondary phase were deposited via APS. Monolithic coatings composed of cubic Low-k and t' Low-k were also deposited, in addition to a 7YSZ benchmark. The thermal conductivity and erosion durability were then measured and it was found that both of the Low-k materials have significantly reduced thermal conductivities, with monolithic t' Low-k and cubic Low-k improving upon 7YSZ by approximately 13 and approximately 25%, respectively. The 40 wt% t' Low-k composite (40 wt% t' Low-k - 60 wt% cubic Low-k) showed a approximately 22% reduction in thermal conductivity over 7YSZ, indicating even at high levels, the t' Low-k secondary phase had a minimal impact on thermal in the composite coating. It was observed that a mere 20 wt% t' Low-k phase addition can reduce the erosion of a cubic Low-k matrix phase composite coating by over 37%. Various mixing rules were then investigated to assess this non-linear composite behavior and suggestions were made to further improve erosion durability.

  10. Composition and property measurements for PHA Phase 4 glasses

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.B.

    2000-01-25

    The results presented in this report are for nine Precipitate Hydrolysis Aqueous (PHA) Phase 4 glasses. Three of the glasses contained HM sludge at 22, 26, and 30 wt% respectively, 10 wt% PHA and 1.25 wt% monosodium titanate (MST), all on an oxide basis. The remaining six glasses were selected from the Phase 1 and Phase 2 studies (Purex sludge) but with an increased amount of MST. The high-end target for MST of 2.5 wt% oxide was missed in Phases 1 and 2 due to {approximately}30 wt% water content of the MST. A goal of this Phase 4 study was to determine whether this increase in titanium concentration from the MST had any impact on glass quality or processibility. Two of the glasses, pha14c and pha15c, were rebatched and melted due to apparent batching errors with pha14 and pha15. The models currently in the Defense Waste Processing Facility's (DWPF) Product Composition Control System (PCCS) were used to predict durability, homogeneity, liquidus, and viscosity for these nine glasses. All of the HM glasses and half of the Purex glasses were predicted to be phase separated, and consequently prediction of glass durability is precluded with the cument models for those glasses that failed the homogeneity constraint. If one may ignore the homogeneity constraint, the measured durabilities were within the 95% prediction limits of the model. Further efforts will be required to resolve this issue on phase separation (inhomogeneity). The liquidus model predicted unacceptable liquidus temperatures for four of the nine glasses. The approximate, bounding liquidus temperatures measured for all had upper limits of 1,000 C or less. Given the fact that liquidus temperatures were only approximated, the 30 wt% loading of Purex may be near or at the edge of acceptability for liquidus. The measured viscosities were close to the predictions of the model. For the Purex glasses, pha12c and pha15c, the measured viscosities of 28 and 23 poise, respectively, indicate that DWPF processing

  11. Plasma Profile Measurements for Laser Fusion Research with the Nike KrF Laser

    Science.gov (United States)

    Oh, Jaechul; Weaver, J. L.; Serlin, V.; Obenschain, S. P.

    2015-11-01

    The grid image refractometer of the Nike laser facility (Nike-GIR) has demonstrated the capability of simultaneously measuring electron density (ne) and temperature (Te) profiles of coronal plasma. For laser plasma instability (LPI) research, the first Nike-GIR experiment successfully measured the plasma profiles in density regions up to ne ~ 4 ×1021 cm-3 (22% of the critical density for 248 nm light of Nike) using an ultraviolet probe laser (λp = 263 nm). The probe laser has been recently replaced with a shorter wavelength laser (λp = 213 nm, a 5th harmonic of the Nd:YAG laser) to diagnose a higher density region. The Nike-GIR system is being further extended to measure plasma profiles in the on-going experiment using 135°-separated Nike beam arrays for the cross-beam energy transfer (CBET) studies. We present an overview of the extended Nike-GIR arrangements and a new numerical algorithm to extract self-consistant plasma profiles with the measured quantities. Work supported by DoE/NNSA.

  12. Mineral-Based Coating of Plasma-Treated Carbon Fibre Rovings for Carbon Concrete Composites with Enhanced Mechanical Performance

    Science.gov (United States)

    Schneider, Kai; Lieboldt, Matthias; Liebscher, Marco; Fröhlich, Maik; Hempel, Simone; Butler, Marko; Schröfl, Christof; Mechtcherine, Viktor

    2017-01-01

    Surfaces of carbon fibre roving were modified by means of a low temperature plasma treatment to improve their bonding with mineral fines; the latter serving as an inorganic fibre coating for the improved mechanical performance of carbon reinforcement in concrete matrices. Variation of the plasma conditions, such as gas composition and treatment time, was accomplished to establish polar groups on the carbon fibres prior to contact with the suspension of mineral particles in water. Subsequently, the rovings were implemented in a fine concrete matrix and their pull-out performance was assessed. Every plasma treatment resulted in increased pull-out forces in comparison to the reference samples without plasma treatment, indicating a better bonding between the mineral coating material and the carbon fibres. Significant differences were found, depending on gas composition and treatment time. Microscopic investigations showed that the samples with the highest pull-out force exhibited carbon fibre surfaces with the largest areas of hydration products grown on them. Additionally, the coating material ingresses into the multifilament roving in these specimens, leading to better force transfer between individual carbon filaments and between the entire roving and surrounding matrix, thus explaining the superior mechanical performance of the specimens containing appropriately plasma-treated carbon roving. PMID:28772719

  13. Development of Polysulfone Hollow Fiber Porous Supports for High Flux Composite Membranes: Air Plasma and Piranha Etching

    Directory of Open Access Journals (Sweden)

    Ilya Borisov

    2017-02-01

    Full Text Available For the development of high efficiency porous supports for composite membrane preparation, polysulfone (PSf hollow fiber membranes (outer diameter 1.57 mm, inner diameter 1.12 mm were modified by air plasma using the low temperature plasma treatment pilot plant which is easily scalable to industrial level and the Piranha etch (H2O2 + H2SO4. Chemical and plasma modification affected only surface layers and did not cause PSf chemical structure change. The modifications led to surface roughness decrease, which is of great importance for further thin film composite (TFC membranes fabrication by dense selective layer coating, and also reduced water and ethylene glycol contact angle values for modified hollow fibers surface. Furthermore, the membranes surface energy increased two-fold. The Piranha mixture chemical modification did not change the membranes average pore size and gas permeance values, while air plasma treatment increased pore size 1.5-fold and also 2 order enhanced membranes surface porosity. Since membranes surface porosity increased due to air plasma treatment the modified membranes were used as efficient supports for preparation of high permeance TFC membranes by using poly[1-(trimethylsilyl-1-propyne] as an example for selective layer fabrication.

  14. Gas Temperature Measurements of Fluctuating Coal - MHD Plasmas Using Modified Line Reversal.

    Science.gov (United States)

    Winkleman, Bradley Carl

    The technique of modified line reversal is investigated and developed to allow accurate measurements on fluctuating coal fired magnetohydrodynamic plasmas and flows. Generalized modified line reversal equations applicable to any geometry and optical system are developed and presented. The generalized equations are specialized to the two most common optical systems, focussed and collimated, employed for modified line reversal measurements. Approximations introduced by specializing to the specific optical systems are investigated. Vignetting of the optical system images is shown to introduce large biases in the temperature measurement for certain optical configurations commonly applied. It is shown that symmetric optical systems are unacceptable for line reversal measurements. The errors introduced by non-simultaneous measurement of the required line reversal parameters due to rapidly fluctuating plasma characteristics are characterized. Line reversal signal and temperature measurements made on a coal fired MHD plasma are used to quantify the error in the temperature measurement due to non-simultaneous sampling of the measured line reversal parameters. A simple modified line reversal system based on interference filters and photodiodes that employs spatial separation to obtain the required line reversal parameters is described. Gas temperatures measured with devices using both the spatial and temporal separation techniques are compared. Modified line reversal temperature measurements are compared to theoretically predicted temperatures as well as CARS and high velocity thermocouple temperature measurements.

  15. Charge-state and element-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres

    CERN Document Server

    Franz, Robert; Anders, André

    2014-01-01

    The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al$^{+}$ regardless of the background gas species, whereas Cr$^{2+}$ ions were dominating in Ar and N$_2$ and Cr$^{+}$ in O$_2$ atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high energy fraction due to acceleration in the expanding plasma plume from the cathode spot and thermalised ions that were subjected to collisions in the plasma cloud. The fraction of the latter increased with increasing background gas pressure. Atomic nitrogen and oxygen ions showed similar energy distributions as the aluminium and chromium ions, whereas the argon and molecular nitrogen and oxygen ions were mainly thermalised. In addition to the positively charged metal and gas ions, negatively charged oxygen an...

  16. Suprathermal plasma analyzer for the measurement of low-energy electron distribution in the ionosphere.

    Science.gov (United States)

    Shimoyama, M; Oyama, K-I; Abe, T; Yau, A W

    2011-07-01

    It is commonly believed that an energy transfer from thermal to suprathermal electrons (thermal to suprathermal energy continuously with high-energy resolution of about 0.15 eV. The measurement principle is based on the combination of a retarding potential analyzer with a channel electron multiplier (CEM) and the Druyvesteyn method, which derives energy distribution from the current-voltage characteristics. The capability of detecting plasma space potential enables absolute calibration of electron energy. The instrument with a small vacuum pump, which is required for the CEM to work in low-vacuum region, was first successfully tested by a sounding rocket S-310-37 in the ionospheric E region. The instrument is expected to provide new opportunities to measure energy distribution of thermal and non-thermal electrons in low-density plasma, where a Langmuir probe cannot measure electron temperature because of low plasma density.

  17. Measurements of plasma density fluctuations and electric wave fields using spherical electrostatic probes

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, A.I.; Bostroem, R.

    1995-04-01

    Spherical electrostatic probes are in wide use for the measurements of electric fields and plasma density. This report concentrates on the measurements of fluctuations of these quantities rather than background values. Potential problems with the technique include the influence of density fluctuations on electric field measurements and vice versa, effects of varying satellite potential, and non-linear rectification in the probe and satellite sheaths. To study the actual importance of these and other possible effects, we simulate the response of the probe-satellite system to various wave phenomena in the plasma by applying approximate analytical as well as numerical methods. We use a set of non-linear probe equations, based on probe characteristics experimentally obtained in space, and therefore essentially independent of any specific probe theory. This approach is very useful since the probe theory for magnetized plasmas is incomplete. 47 refs.

  18. IP-10 can be measured in dried plasma spots in patients with chronic hepatitis C infection.

    Directory of Open Access Journals (Sweden)

    Morten Ruhwald

    Full Text Available The chemokine IP-10 (CXCL10 is a candidate marker for hepatitis C virus (HCV fibrosis monitoring. The aim of this proof-of-concept study is to assess if IP-10 measurements from dried plasma spots (DPS are accurate in HCV-infected patients with either minimal or significant fibrosis. We measured IP-10 levels in plasma and DPS of 21 HCV-infected patients with cirrhosis and 19 patients with no/little fibrosis (determined with FibroScan. Cirrhotic patients had significantly higher levels of IP-10 compared to patients with minimal fibrosis. DPS and plasma measurements of IP-10 are comparable and the correlation was excellent (r(2 = 0.97, p<0.0001. The DPS based method for IP-10 detection performs well in HCV-infected patients with either minimal or significant fibrosis.

  19. Determination of the Ion Velocity Distribution in a Rotating Plasma from Measurements of Doppler Broadening

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard

    1979-01-01

    The Doppler-broadened profile of the He II 4685.75 AA line was measured along a chord in a rotating plasma, transverse to the magnetic field. Using a single-particle orbit picture, the corresponding velocity spectrum of ions confirm the measurements, so it can be concluded that the single......-particle orbit picture is valid for the discharge period under investigation, except for the first few microseconds during breakdown when a strong interaction between plasma and remaining neutral gas takes place by Alfvens critical velocity mechanism. A simple relation is given between the measured half......-width and shift of the Doppler profile and the macroscopic quantities of ion velocity and energy. Several Doppler-broadened profiles are shown for different plasma parameters....

  20. Spatially Resolved Measurements of a Double Layer in an Argon Helicon Plasma

    Science.gov (United States)

    Aguirre, Evan; Siddiqui, Umair; McKee, John; Scime, Earl

    2015-11-01

    We report 2-dimensional, spatially resolved observations of a double layer in an expanding helicon plasma. These new measurements investigate the origins of previously observed multiple ion beam populations in the downstream plasma. We use Laser Induced Fluorescence (LIF) to measure the ion velocity distribution functions (IVDFs) of argon ions and neutrals both parallel and perpendicular to the background magnetic field and an rf-compensated Langmuir probe to determine the local plasma potential. These are the first multi-dimensional LIF measurements of ion acceleration in a current-free double layer and were obtained with a recently installed, internal scanning probe system in the HELIX-LEIA experimental facility. This work is supported by US National Science Foundation grant number PHY-1360278.

  1. One-Step Synthesis of Pt/Graphene Composites from Pt Acid Dissolved Ethanol via Microwave Plasma Spray Pyrolysis

    Science.gov (United States)

    Jo, Eun Hee; Chang, Hankwon; Kim, Sun Kyung; Choi, Ji-Hyuk; Park, Su-Ryeon; Lee, Chong Min; Jang, Hee Dong

    2016-09-01

    Pt nanoparticles-laden graphene (Pt/GR) composites were synthesized in the gas phase from a mixture of ethanol and Pt precursor by microwave plasma spray pyrolysis. The morphology of Pt/GR composites has the shape of wrinkled sheets of paper, while Pt nanoparticles (Pt NPs) that are less than 2.6 nm in the mean diameter are uniformly well deposited on the surface of GR sheets stacked in only three layers. The Pt/GR composite prepared with 20 wt% of Pt had the highest specific surface area and electrochemical surface area of up to 402 m2 g-1 and 77 m2 g-1 (Pt), respectively. In addition, the composite showed superior electrocatalytic activity compared with commercial Pt-carbon black. The excellent electrocatalytic activity was attributed to the high specific surface area and electrochemical surface area of the Pt/GR composite directly produced by microwave plasma spray pyrolysis. Thus, it is clearly expected that the Pt/GR composite is a promising material for DMFC catalysts.

  2. Curling probe measurement of large-volume pulsed plasma confined by surface magnetic field

    Science.gov (United States)

    Pandey, Anil; Sakakibara, Wataru; Matsuoka, Hiroyuki; Nakamura, Keiji; Sugai, Hideo; Chubu University Team; DOWA Thermotech Collaboration

    2015-09-01

    Curling probe (CP) has recently been developed which enables the local electron density measurement even in plasma for non-conducting film CVD. The electron density is obtained from a shift of resonance frequency of spiral antenna in discharge ON and OFF monitored by a network analyzer (NWA). In case of a pulsed glow discharge, synchronization of discharge pulse with frequency sweep of NWA must be established. In this paper, we report time and space-resolved CP measurement of electron density in a large volume plasma (80 cm diameter, 110 cm length) confined by surface magnetic field (multipole cusp field ~0.03 T). For plasma-aided modification of metal surface, the plasma is produced by 1 kV glow discharge at pulse frequency of 0.3 - 25 kHz with various duty ratio in gas (Ar, N2, C2H2) at pressure ~ 1 Pa. A radially movable CP revealed a remarkable effect of surface magnetic confinement: detach of plasma from the vessel wall and a fairly uniform plasma in the central region. In afterglow phase, the electron density was observed to decrease much faster in C2H2 discharge than in Ar discharge.

  3. Fetuses of lean and obese swine in late gestation: body composition, plasma hormones and muscle development.

    Science.gov (United States)

    Hoffman, E C; Wangsness, P J; Hagen, D R; Etherton, T D

    1983-09-01

    The development of obesity in porcine fetuses was investigated using a lean and obese strain of pigs at 80, 90, 100 and 110 d of gestation. In absolute terms, fetuses of obese gilts (FO) generally had lower carcass weight and contained less total protein, dry matter and ash than fetuses of lean gilts (FL). In relative terms (percentage of wet carcass weight) FO, compared with FL, generally had decreased percentages of water and increased percentages of protein and lipid. Comparisons based on absolute terms revealed body composition of the strains to be different at 90 d, indicating that factors responsible for obese-type growth were active before that time. Both body composition and hormone concentration differences were most pronounced at later gestation ages. Depressed growth hormone, elevated cortisol, and a tendency toward elevated insulin concentrations in fetal plasma were apparent in late gestation for FO compared with FL. These hormonal patterns are consistent with onset of obesity in FO in late gestation. Greater weights of semitendinosus and longissimus muscles were observed in FL vs FO at 90, 100 and 110 d of gestation (P less than .05). These greater muscle weights were generally accompanied by greater contents of RNA, DNA and protein in FL muscles at these same ages. However, at 80 d, FL had greater absolute DNA content in semitendinosus muscle whereas muscle weight was similar between the strains. This suggests that greater muscle weights for FL than FO were caused by more nuclei in muscle of FL. In general, indices of hypertrophy (protein/DNA) and protein synthetic capacity (RNA/DNA) of muscle were usually similar for both strains at all gestation ages. It is concluded that decreased muscle growth in late gestation of FO compared with FL is more related to fewer total nuclei and perhaps fewer myofibers than to an impaired cellular capacity for protein synthesis.

  4. Measuring electron-positron annihilation radiation from laser plasma interactionsa)

    Science.gov (United States)

    Chen, Hui; Tommasini, R.; Seely, J.; Szabo, C. I.; Feldman, U.; Pereira, N.; Gregori, G.; Falk, K.; Mithen, J.; Murphy, C. D.

    2012-10-01

    We investigated various diagnostic techniques to measure the 511 keV annihilation radiations. These include step-wedge filters, transmission crystal spectroscopy, single-hit CCD detectors, and streaked scintillating detection. While none of the diagnostics recorded conclusive results, the step-wedge filter that is sensitive to the energy range between 100 keV and 700 keV shows a signal around 500 keV that is clearly departing from a pure Bremsstrahlung spectrum and that we ascribe to annihilation radiation.

  5. Measuring electron-positron annihilation radiation from laser plasma interactions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hui; Tommasini, R. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Seely, J.; Szabo, C. I.; Feldman, U.; Pereira, N. [Artep Inc., Ellicott City, Maryland 21042 (United States); Gregori, G.; Falk, K.; Mithen, J.; Murphy, C. D. [Clarendon Laboratory, University of Oxford, Oxford OX1 3PU (United Kingdom)

    2012-10-15

    We investigated various diagnostic techniques to measure the 511 keV annihilation radiations. These include step-wedge filters, transmission crystal spectroscopy, single-hit CCD detectors, and streaked scintillating detection. While none of the diagnostics recorded conclusive results, the step-wedge filter that is sensitive to the energy range between 100 keV and 700 keV shows a signal around 500 keV that is clearly departing from a pure Bremsstrahlung spectrum and that we ascribe to annihilation radiation.

  6. Electron spectroscopic analysis of the human lipid skin barrier: cold atmospheric plasma-induced changes in lipid composition.

    Science.gov (United States)

    Marschewski, Marcel; Hirschberg, Joanna; Omairi, Tarek; Höfft, Oliver; Viöl, Wolfgang; Emmert, Steffen; Maus-Friedrichs, Wolfgang

    2012-12-01

    The lipids of the stratum corneum comprise the most important components of the skin barrier. In patients with ichthyoses or atopic dermatitis, the composition of the skin barrier lipids is disturbed resulting in dry, scaly, itching erythematous skin. Using the latest X-Ray Photoelectron Spectroscopy (XPS) technology, we investigated the physiological skin lipid composition of human skin and the effects of cold atmospheric plasma treatment on the lipid composition. Skin lipids were stripped off forearms of six healthy volunteers using the cyanoacrylate glue technique, plasma treated or not and then subjected to detailed XPS analysis. We found that the human lipid skin barrier consisted of 84.4% carbon (+1.3 SEM%), 10.8% oxygen (+1.0 SEM%) and 4.8% nitrogen (+0.3 SEM%). The composition of physiological skin lipids was not different in males and females. Plasma treatment resulted in significant changes in skin barrier lipid stoichiometry. The total carbon amount was reduced to 76.7%, and the oxygen amount increased to 16.5%. There was also a slight increase in nitrogen to 6.8%. These changes could be attributed to reduced C-C bonds and increased C-O, C=O, C-N and N-C-O bonds. The moderate increase in nitrogen was caused by an increase in C-N and N-C-O bonds. Our results show for the first time that plasma treatment leads to considerable changes in the human skin lipid barrier. Our proof of principle investigations established the technical means to analyse, if plasma-induced skin lipid barrier changes may be beneficial in the treatment of ichthyotic or eczematous skin.

  7. Measurements of laser-hole boring into overdense plasmas using x-ray laser refractometry (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, R.; Takahashi, K.; Tanaka, K.A.; Kato, Y. [Institute of Laser Engineering (ILE), Osaka University, Suita, Osaka 565 (Japan); Murai, K. [DMP, ONRI, Ikeda, Osaka 563 (Japan); Weber, F.; Barbee, T.W.; DaSilva, L.B. [Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (United States)

    1999-01-01

    We developed a 19.6 nm laser x-ray laser grid-image refractometer (XRL-GIR) to diagnose laser-hole boring into overdense plasmas. The XRL-GIR was optimized to measure two-dimensional electron density perturbation on a scale of a few tens of {mu}m in underdense plasmas. Electron density profiles of laser-produced plasmas were obtained for 10{sup 20}{endash}10{sup 22}thinspcm{sup {minus}3} with the XRL-GIR and for 10{sup 19}{endash}10{sup 20}thinspcm{sup {minus}3} from an ultraviolet interferometer, the profiles of which were compared with those from hydrodynamic simulation. By using this XRL-GIR, we directly observed laser channeling into overdense plasmas accompanied by a bow shock wave showing a Mach cone ascribed to supersonic propagation of the channel front. {copyright} {ital 1999 American Institute of Physics.}

  8. Langmuir Probe Measurements in an Inductively Coupled GEC Reference Cell Plasma

    Science.gov (United States)

    Ji, J. S.; Kim, J. S.; Cappelli, M. A.; Sharma, S. P.; Arnold, J. O. (Technical Monitor)

    1998-01-01

    Measurements of electron number density, electron temperature, and electron energy distribution function (EEDF) using a compensated Langmuir probe have been performed on an inductively (transformer ) coupled Gaseous Electronics Conference (GEC) reference cell plasma. The plasma source is operated with CH4, CF4, or their mixtures with argon. The effect of independently driving the electrode supporting the wafer on the probe data is studied. In particular, we find that the plasma structure depends on the phase in addition to the magnitude of the power coupled to the electrode relative to that of the transformer coil. The Langmuir probe is translated in a plane parallel to the electrode to investigate the spatial structure of the plasma. The probe data is also compared with fluid model predictions.

  9. Ion sensitive probe measurement in the linear plasma device PSI-2

    Energy Technology Data Exchange (ETDEWEB)

    Ezumi, N. [Nagano National College of Technology, 716 Tokuma, Nagano 381-8550 (Japan)]. E-mail: ezumi@ec.nagano-nct.ac.jp; Kiss' ovski, Zh. [Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria); Bohmeyer, W. [Max-Planck-Institut fuer Plasmaphysik, Bereich Plasmadiagnostik, Brook-Taylor-Str. 6, 12489 Berlin (Germany); Fussmann, G. [Max-Planck-Institut fuer Plasmaphysik, Bereich Plasmadiagnostik, Brook-Taylor-Str. 6, 12489 Berlin (Germany)

    2005-03-01

    The suitability of an ion sensitive probe (ISP) with respect to ion temperature (T {sub i}) measurements has been tested in the linear plasma generator in PSI-2. Current-voltage (I-V) characteristics were recorded as a function of two key parameters: shielding height (h) and potential differences between inner and outer electrodes (V {sub B}). It could be experimentally confirmed that the current within the electron saturation region is reduced with increasing h. Furthermore, the I-V characteristics change drastically when V {sub B} is varied. Radial profiles of the plasma parameters including plasma and floating potentials could be taken. Whereas the T {sub i} values determined by ISP in the plasma core region agree fairly with those obtained by using a local optical probe, severe interpretation difficulties occurred for the outer regions.

  10. AMPTE/CCE observations of the plasma composition below 17 keV during the September 4, 1984 magnetic storm

    Energy Technology Data Exchange (ETDEWEB)

    Shelley, E.G.; Klumpar, D.M.; Peterson, W.K.; Ghielmetti, A.; Balsiger, H.; Geiss, J.; Rosenbauer, H.

    1985-05-01

    Observations from the Hot Plasma Composition Experiment on the AMPTE/CCE spacecraft during the magnetic storm of 4-5 September 1984 reveal that significant injection of ions of terrestrial origin accompanied the storm development. The compression of the magnetosphere at storm sudden commencement carried the magnetopause inside the CCE orbit clearly revealing the shocked solar wind plasma. A build up of suprathermal ions is observed near the plasmapause during the storm main phase and recovery phase. Pitch angle distributions in the ring current during the main phase show differences between H(+) and O(+) that suggest mass dependent injection, transport and/or loss processes. 9 references.

  11. AMPTE/CCE observations of the plasma composition below 17 keV during the September 4, 1984 magnetic storm

    Science.gov (United States)

    Shelley, E. G.; Klumpar, D. M.; Peterson, W. K.; Ghielmetti, A.; Balsiger, H.; Geiss, J.; Rosenbauer, H.

    1985-05-01

    Observations from the Hot Plasma Composition Experiment on the AMPTE/CCE spacecraft during the magnetic storm of 4-5 September 1984 reveal that significant injection of ions of terrestrial origin accompanied the storm development. The compression of the magnetosphere at storm sudden commencement carried the magnetopause inside the CCE orbit clearly revealing the shocked solar wind plasma. A build up of suprathermal ions is observed near the plasmapause during the storm main phase and recovery phase. Pitch angle distributions in the ring current during the main phase show differences between H(+) and O(+) that suggest mass dependent injection, transport and/or loss processes.

  12. Compositional segmentation and complexity measurement in stock indices

    Science.gov (United States)

    Wang, Haifeng; Shang, Pengjian; Xia, Jianan

    2016-01-01

    In this paper, we introduce a complexity measure based on the entropic segmentation called sequence compositional complexity (SCC) into the analysis of financial time series. SCC was first used to deal directly with the complex heterogeneity in nonstationary DNA sequences. We already know that SCC was found to be higher in sequences with long-range correlation than those with low long-range correlation, especially in the DNA sequences. Now, we introduce this method into financial index data, subsequently, we find that the values of SCC of some mature stock indices, such as S & P 500 (simplified with S & P in the following) and HSI, are likely to be lower than the SCC value of Chinese index data (such as SSE). What is more, we find that, if we classify the indices with the method of SCC, the financial market of Hong Kong has more similarities with mature foreign markets than Chinese ones. So we believe that a good correspondence is found between the SCC of the index sequence and the complexity of the market involved.

  13. Implications of solar wind measurements for solar models and composition

    CERN Document Server

    Serenelli, Aldo; Villante, Francesco L; Vincent, Aaron C; Asplund, Martin; Basu, Sarbani; Grevesse, Nicolas; Pena-Garay, Carlos

    2016-01-01

    We critically examine recent claims of a high solar metallicity by von Steiger \\& Zurbuchen (2016; vSZ16) based on in situ measurements of the solar wind, rather than the standard spectroscopically-inferred abundances (Asplund et al. 2009). We test the claim by Vagnozzi et al. (2016) that a composition based on the solar wind enables one to construct a standard solar model in agreement with helioseismological observations and thus solve the decades-old solar modelling problem. We show that, although some helioseismological observables are improved compared to models computed with established abundances, most are in fact worse. The high abundance of refractory elements leads to an overproduction of neutrinos, with a predicted $^8$B flux that is nearly twice its observed value, and $^7$Be and CNO fluxes that are experimentally ruled out at high confidence. A combined likelihood analysis shows that models using the vSZ16 abundances fare much worse than AGSS09 despite a higher metallicity. We also present ast...

  14. Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

    Science.gov (United States)

    Murthy, Pappu L. N.; Thesken, John C.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie

    2007-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are often used for storing pressurant gases onboard spacecraft. Kevlar (DuPont), glass, carbon and other more recent fibers have all been used as overwraps. Due to the fact that overwraps are subjected to sustained loads for an extended period during a mission, stress rupture failure is a major concern. It is therefore important to ascertain the reliability of these vessels by analysis, since the testing of each flight design cannot be completed on a practical time scale. The present paper examines specifically a Weibull statistics based stress rupture model and considers the various uncertainties associated with the model parameters. The paper also examines several reliability estimate measures that would be of use for the purpose of recertification and for qualifying flight worthiness of these vessels. Specifically, deterministic values for a point estimate, mean estimate and 90/95 percent confidence estimates of the reliability are all examined for a typical flight quality vessel under constant stress. The mean and the 90/95 percent confidence estimates are computed using Monte-Carlo simulation techniques by assuming distribution statistics of model parameters based also on simulation and on the available data, especially the sample sizes represented in the data. The data for the stress rupture model are obtained from the Lawrence Livermore National Laboratories (LLNL) stress rupture testing program, carried out for the past 35 years. Deterministic as well as probabilistic sensitivities are examined.

  15. IR-LAS Measurements of a Pulsed Xenon Discharge Plasma

    Science.gov (United States)

    Jinno, Masafumi; Wada, Ryota; Motomura, Hideki; Aono, Masaharu

    As a first step to understand the processes taking place in a pulsed xenon discharge, the temporal behavior of the radial metastable atom distribution in a xenon lamp was measured by IR laser absorption spectroscopy. During the first 10μs after starting the discharge, high electron density and the depletion of the ground state atoms at the center of the discharge brought about an almost flat distribution of the metastable atoms within the half-radius area. Following that, the metastable atom density became higher at the center than outside because of recombination between electrons and ions. After the metastable density increase and following voltage cut off, the metastable density decreases again. Considering the diffusion equation alongside these results, it becomes clear that the decrease of the metastable density is caused by quenching to the resonace level from the metastable level or three-body collisions forming excimers.

  16. Quantification of aerosol chemical composition using continuous single particle measurements

    Science.gov (United States)

    Jeong, C.-H.; McGuire, M. L.; Godri, K. J.; Slowik, J. G.; Rehbein, P. J. G.; Evans, G. J.

    2011-07-01

    Mass concentrations of sulphate, nitrate, ammonium, organic carbon (OC), elemental carbon (EC) were determined from real time single particle data in the size range 0.1-3.0 μm measured by an Aerosol Time-of-Flight Mass Spectrometer (ATOFMS) at urban and rural sites in Canada. To quantify chemical species within individual particles measured by an ATOFMS, ion peak intensity of m/z -97 for sulphate, -62 for nitrate, +18 for ammonium, +43 for OC, and +36 for EC were scaled using the number and size distribution data by an Aerodynamic Particle Sizer (APS) and a Fast Mobility Particle Sizer (FMPS). Hourly quantified chemical species from ATOFMS single-particle analysis were compared with collocated fine particulate matter (aerodynamic diameter PM2.5) chemical composition measurements by an Aerosol Mass Spectrometer (AMS) at a rural site, a Gas-Particle Ion Chromatograph (GPIC) at an urban site, and a Sunset Lab field OCEC analyzer at both sites. The highest correlation was found for nitrate, with correlation coefficients (Pearson r) of 0.89 (ATOFMS vs. GPIC) and 0.85 (ATOFMS vs. AMS). ATOFMS mass calibration factors, determined for the urban site, were used to calculate mass concentrations of the major PM2.5 chemical components at the rural site near the US border in southern Ontario. Mass reconstruction using the ATOFMS mass calibration factors agreed very well with the PM2.5 mass concentrations measured by a Tapered Element Oscillating Microbalance (TEOM, r = 0.86) at the urban site and a light scattering monitor (DustTrak, r = 0.87) at the rural site. In the urban area nitrate was the largest contributor to PM2.5 mass in the winter, while organics and sulphate contributed ~64 % of the summer PM2.5 in the rural area, suggesting a strong influence of regional/trans-boundary pollution. The mass concentrations of five major species in ten size-resolved particle-types and aerosol acidity of each particle-type were determined for the rural site. On a mass basis sulphate

  17. Optical Measurements of Dense Hypervelocity Plasmoids from Coaxial and Railgun Plasma Accelerators

    Science.gov (United States)

    Case, Andrew; Messer, Sarah; Bomgardner, Richard; Brockington, Samuel; Witherspoon, Douglas; Elton, Ray

    2009-11-01

    High velocity dense plasma jets are under continued experimental development for fusion applications including refueling, disruption mitigation, momentum injection/rotation drive, and magnetized target fusion. We present measurements taken on the plasmoids produced by a half-scale coaxial plasmoid accelerator, a full scale coaxial plasmoid accelerator, and a novel minirailgun accelerator. The data presented includes spectroscopic measurements of velocity and density, two point interferometric measurements of line integrated density and velocity, and fast framing camera imaging. Results from these measurements are in agreement with each other and with time of flight measurements taken using photodiodes, as well as total plasmoid momentum measurements taken using a ballistic pendulum technique. Plasma density is greater than 5 x10^15 cm-3, and velocities range up to 100 km/s, with a small component in some cases exceeding 120 km/s.

  18. Calibration procedure for plasma polarimetry based on the complex amplitude ratio measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bieg, Bohdan, E-mail: b.bieg@am.szczecin.pl [Maritime University, Szczecin (Poland); Kravtsov, Yury A.; Cieplik, Marek [Maritime University, Szczecin (Poland)

    2013-10-15

    New methodology for plasma polarimeters calibration is suggested, based on the complex amplitude ratio (CAR) measurements. This methodology reduces calibration to determination of three complex parameters of transfer matrix, characterizing polarization changes in optical system. Having obtained transfer matrix, full characteristic of the optic system could be obtained: eigenstates, phase shift and relative attenuation of the slow and fast wave. Polarization state of the sounding electromagnetic wave after the plasma is determined from the measured complex amplitude ratio by simple inversion of transfer matrix. Calibration procedure under discussion is simpler, more transparent and reliable than traditional procedures, using Stokes vector technique or angular parameters of polarization ellipse.

  19. Coordinated underground measurements of gamma-ray emitting radionuclides for plasma physics research.

    Science.gov (United States)

    Tzika, Faidra; Hult, Mikael; Fenyvesi, András; Bandac, Iulian; Degering, Detlev; Ianni, Aldo; Laubenstein, Matthias; de Vismes-Ott, Anne; Marissens, Gerd; Stroh, Heiko; Lutter, Guillaume; Son, Soohyun; Hong, Suk-Ho; Kim, Jun Young; Kim, Junghee; Cheon, Mun Seung; Jo, Jungmin; Braun, Mihály; Németh, József; Zoletnik, Sándor; Bonheure, Georges

    2017-08-01

    Forty-eight samples made of CaF2, LiF and YVO4 were placed inside the KSTAR Tokamak and irradiated by neutrons and charged particles from eight plasma pulses. The aim was to provide information for plasma diagnostics. Due to the short pulse durations, the activities induced in the samples were low and therefore measurements were performed in five low-background underground laboratories. Details of the underground measurements, together with data on the quality control amongst the radiometric laboratories, are presented. Copyright © 2016. Published by Elsevier Ltd.

  20. Large density amplification measured on jets ejected from a magnetized plasma gun

    OpenAIRE

    Yun, Gunsu S.; You, Setthivoine; Bellan, Paul M.

    2007-01-01

    Observation of a large density amplification in the collimating plasma jet ejected from a coplanar coaxial plasma gun is reported. The jet velocity is ~30 km s^-1 and the electron density increases from ~10^20 to 10^(22–23) m^-3. In previous spheromak experiments, electron density of the order 10^(19–21) m^-3 had been measured in the flux conserver region, but no density measurement had been reported for the source gun region. The coplanar geometry of our electrodes permits direct observation...

  1. Ceramic-intermetallic composites produced by mechanical alloying and spark plasma sintering

    CERN Document Server

    Cabanas-Moreno, J G; Martínez-Sanchez, R; Delgado-Gutierrez, O; Palacios-Gomez, J; Umemoto, M

    1998-01-01

    Nano-and microcomposites of intermetallic (Co/sub 3/Ti, AlCo/sub 2 /Ti) and ceramic (TiN, Ti(C, N), Al/sub 2/O/sub 3/) phases have been produced by spark plasma sintering (SPS) of powders resulting from mechanical alloying of Al-Co-Ti elemental powder mixtures. The mechanically alloyed powders consisted of mixtures of nanocrystalline and amorphous phases which, on sintering, transformed into complex microstructures of the intermetallic and ceramic phases. For Al contents lower than about 30 at% in the original powder mixtures, the use of SPS led to porosities of 1-2% in the sintered compacts and hardness values as high as ~1700 kg/mm/sup 2/; in these cases, the composite matrix was TiN and Ti(C, N), with the Al/sub 2/O/sub 3/ phase found as finely dispersed particles in the matrix and the Co /sub 3/Ti and AlCo/sub 2/Ti phases as interdispersed grains. (19 refs).

  2. An experiment to measure the electron-ion thermal equilibration rate in a strongly coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Taccetti, J M; Shurter, R P; Roberts, J P; Benage, J F; Graden, B; Haberle, B; Murillo, M S; Vigil, B; Wysocki, F J [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2006-04-28

    We present the most recent results from an experiment aimed at obtaining the temperature equilibration rate between ions and electrons in a strongly coupled plasma by directly measuring the temperature of each component. The plasma is formed by heating a sonic gas jet with a 10 ps laser pulse. The electrons are preferentially heated by the short pulse laser (we are aiming for T{sub e} {approx} 100 eV), while the ions, after undergoing very rapid (sub-ps timescale) disorder-induced heating, should only reach a temperature of 10-15 eV. This results in a strongly coupled ion plasma with a {gamma}{sub ii} {approx} 3-5. We plan to measure the electron and ion temperatures of the resulting plasma independently during and after heating, using collective Thomson scattering for electrons and a high-resolution x-ray spectrometer for the ions (measuring Doppler-broadened absorption lines). Theory indicates that the equilibration rate could be significantly lower than that given by the usual weakly coupled model (Landau-Spitzer) due to coupled collective modes present in the dense plasma.

  3. An experiment to measure the electron ion thermal equilibration rate in a strongly coupled plasma

    Science.gov (United States)

    Taccetti, J. M.; Shurter, R. P.; Roberts, J. P.; Benage, J. F.; Graden, B.; Haberle, B.; Murillo, M. S.; Vigil, B.; Wysocki, F. J.

    2006-04-01

    We present the most recent results from an experiment aimed at obtaining the temperature equilibration rate between ions and electrons in a strongly coupled plasma by directly measuring the temperature of each component. The plasma is formed by heating a sonic gas jet with a 10 ps laser pulse. The electrons are preferentially heated by the short pulse laser (we are aiming for Te ~ 100 eV), while the ions, after undergoing very rapid (sub-ps timescale) disorder-induced heating, should only reach a temperature of 10-15 eV. This results in a strongly coupled ion plasma with a Γii ~ 3-5. We plan to measure the electron and ion temperatures of the resulting plasma independently during and after heating, using collective Thomson scattering for electrons and a high-resolution x-ray spectrometer for the ions (measuring Doppler-broadened absorption lines). Theory indicates that the equilibration rate could be significantly lower than that given by the usual weakly coupled model (Landau-Spitzer) due to coupled collective modes present in the dense plasma.

  4. Non-Axisymmetric Disruption SOL Current Measurement In DIII-D Plasmas

    Science.gov (United States)

    Cabrera, Joshua; Hanson, J.; Navratil, G.; Bialek, J.

    2016-10-01

    J. Cabrera, J. Hanson, G. Navratil, J. Bialek, Columbia U-During tokamak disruptions known as vertical displacement events (VDEs) currents which flow between the plasma core and plasma facing components can reach nearly 20% of the total plasma current. These scrape off layer (SOL) currents are thought to affect the dynamics of plasma disruption. We have made use of an array of tile current monitors installed on the DIII-D tokamak to perform low toroidal mode number (n VDEs. In all cases examined (over 30 shots) currents exhibited toroidal asymmetry with toroidal peaking factor 2. Strong initial peaking in n=1 current measurements are correlated with n=1 magnetic fluctuations during VDEs. Following the peak SOL current and after observation of the final last closed flux surface (LCFS), n=1 mode activity 20% of n=0 peak amplitude persists for 10ms. Predictions from the VALEN-IVB simulation code utilizing current profile reconstructions from magnetic sensor array measurements will be compared with SOL current measurements. Possible effects of these SOL currents on plasma dynamics during disruption are considered. Supported by US DOE under DE-FC02-04ER54698 and DE-FG02-04ER54761.

  5. Development of a simple device for processing whole-blood samples into measured aliquots of plasma.

    Science.gov (United States)

    Burtis, C A; Johnson, W F; Walker, W A

    1986-09-01

    A capillary processor and aliquoter has been designed and fabricated that is capable of accepting aliquots of whole blood and automatically processing them into discrete aliquots of plasma. The device consists of two disks, each of which contains 16 individual capillaries and a processing rotor. One disk accepts larger capillaries that hold approximately 100 microL of whole blood each. The second disk accepts 2.54-cm-long precision capillaries of various internal diameters, which provide exact sample volumes from 1 to 10 microL. The processing rotor contains 16 individual compartments and chambers to accept both disks. Applying centrifugal force transfers the aliquots of whole blood into their respective compartments, where they are separated into cellular and plasma fractions. As the rotor speed is slowly decreased, an aliquot of plasma is withdrawn by capillary action into each measuring capillary. The disk containing the 16 measured aliquots of plasma is then removed and placed into a modified rotor for conventional centrifugal analysis. This device can entrain and deliver microliter volumes of liquids with precision and accuracy (1-2%) near that of mechanical pipettes. Assays of the separated plasma aliquots also have acceptable precision (e.g., CVs approximately 3% for measurements of serum enzymes).

  6. Measurement Of Plasma Parameters In Micro-Discharge By Wall Probe

    Science.gov (United States)

    Saifutdinov, Almaz; Kudryavtsev, Anatoly; Sysoev, Sergey

    2016-09-01

    The increasing scientific and practical interest for glow discharge at high pressure is largely determined by the fact that their use does not require expensive and huge vacuum equipment. The analysis shows that, in contrast to the well-studied positive column (PC), the basic parameters of the plasma negative glow (NG) and Faraday dark space (FDS) of micro-discharges are studied insufficiently. The difficulties of the experimental diagnostics are associated with the fact that for the fixed values of pL with the increasing gas pressure the length of the micro-discharge decreases. And a small size is extremely difficult to diagnose spatial parameters distribution of micro discharges. Since at a small size introducing traditional Langmuir probe into the plasma capacity is not possible technically, it was proposed to use an additional measuring electrode (wall probe) disposed between the cathode and the anode for measurement of the fast EEDF. With its use we have registered EEDF fast electrons produced in the reaction of Penning ionization out of earlier reach range of high-pressure gas (from 20 to 200 Torr). In this paper by using wall probe we measured the basic parameters of NG plasma in micro-discharge in helium in a wide range of pressures. It is shown that the electrons temperature in the NG plasma is low and amounts to few fraction of 1 eV, which differs from the electron temperature in PC plasma. This allows the use of NG plasma for analysis by gas plasma electron spectroscopy. Authors thanks RNF (Grant 14-19-00311) for the support.

  7. Operational Characteristics and Plasma Measurements in a Low-Energy FARAD Thruster

    Science.gov (United States)

    Polzin, K. A.; Best, S.; Rose, M. F.; Miller, R.; Owens, T.

    2008-01-01

    Pulsed inductive plasma accelerators are spacecraft propulsion devices in which energy is stored in a capacitor and then discharged through an inductive coil. The device is electrodeless, inducing a plasma current sheet in propellant located near the face of the coil. The propellant is accelerated and expelled at a high exhaust velocity (order of 10 km/s) through the interaction of the plasma current with an induced magnetic field. The Faraday Accelerator with RF-Assisted Discharge (FARAD) thruster is a type of pulsed inductive plasma accelerator in which the plasma is preionized by a mechanism separate from that used to form the current sheet and accelerate the gas. Employing a separate preionization mechanism in this manner allows for the formation of an inductive current sheet at much lower discharge energies and voltages than those found in previous pulsed inductive accelerators like the Pulsed Inductive Thruster (PIT). In this paper, we present measurements aimed at quantifying the thruster's overall operational characteristics and providing additional insight into the nature of operation. Measurements of the terminal current and voltage characteristics during the pulse help quantify the output of the pulsed power train driving the acceleration coil. A fast ionization gauge is used to measure the evolution of the neutral gas distribution in the accelerator prior to a pulse. The preionization process is diagnosed by monitoring light emission from the gas using a photodiode, and a time-resolved global view of the evolving, accelerating current sheet is obtained using a fast-framing camera. Local plasma and field measurements are obtained using an array of intrusive probes. The local induced magnetic field and azimuthal current density are measured using B-dot probes and mini-Rogowski coils, respectively. Direct probing of the number density and electron temperature is performed using a triple probe.

  8. Thrust Stand Measurements Using Alternative Propellants in the Microwave Assisted Discharge Inductive Plasma Accelerator

    Science.gov (United States)

    Hallock, Ashley K.; Polzin, Kurt A.

    2011-01-01

    -pinch coil is high. The use of a conical theta-pinch coil also serves to provide neutral propellant containment and plasma plume focusing that is improved relative to the more common planar geometry of the Pulsed Inductive Thruster (PIT). In this paper, we describe thrust stand measurements performed to evaluate the specific impulse and thrust efficiency of the MAD-IPA for a variety of propellants. Propellants tested include both widely-used, non-reactive noble gases like argon, and rarely-used propellants such as water, hydrazine and ammonia. Dependencies of impulse data on propellant species are discussed in the context of the current sheet formation and electromagnetic plasma acceleration processes.

  9. Ablation behavior and mechanism of 3D Cf/ZrC-SiC composites in a plasma wind tunnel environment

    Directory of Open Access Journals (Sweden)

    Qinggang Li

    2015-12-01

    Full Text Available Three-dimensional needle-like Cf/ZrC-SiC composites were successfully fabricated by polymer infiltration and pyrolysis combined with ZrC precursor impregnation. The ablation properties of the composites were tested in a plasma wind tunnel environment at different temperatures and different times. The microstructure and morphology of the composites were examined after ablation by scanning electron microscopy, and their composition was confirmed by energy dispersive spectroscopy. The composites exhibited good configurational stability with a surface temperature of greater than 2273 K over a 300–1000 s period. The formation of ZrSiO4 and SiO2 melts on the surface of the 3D Cf/ZrC-SiC composites contributed significantly to improvement in their ablation properties. However, these composites exhibited serious ablation when the temperature was increased to 2800 K. The 3D Cf/ZrC-SiC composites obtained after ablation showed three different layers attributed to the temperature and pressure gradients: the ablation central region, the ablation transition region, and the unablation region.

  10. Chemical and plasma surface modification of lignocellulose coconut waste for the preparation of advanced biobased composite materials.

    Science.gov (United States)

    Kocaman, Suheyla; Karaman, Mustafa; Gursoy, Mehmet; Ahmetli, Gulnare

    2017-03-01

    In this study, surface-modified grinded coconut waste (CW) particles were used as bio-fillers to prepare polymeric composite materials with enhanced properties. Epoxy resin modified with acrylated and epoxidized soybean oil (AESO) was used as the polymer matrix. Two different strategies, namely chemical treatment and plasma enhanced chemical vapor deposition (PECVD) were utilized to modify the surface of CW particles for using them as compatible bio-fillers in composite preparation. Chemical modification involved the treatment of CW particles in a highly alkali NaOH solution, while PECVD modification involved coating of a thin film of hydrophobic poly(hexafluorobutyl acrylate) (PHFBA) around individual CW particle surfaces. Untreated and surface-modified CW particles were used in 10-50wt% for preparation of epoxy composites. FTIR analysis was performed to study the effect of modification on the structures of particles and as-prepared composites. The composite morphologies were investigated by XRD and SE. TGA test was conducted to study the thermal behavior of the composites. Also, the effects of CW particle surface modification on the mechanical and water sorption properties of epoxy resin composites were investigated in detail. It was observed that PECVD-treated CW particles had much more positive effects on the thermal, mechanical, wettability and flammability properties of composites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Dry Sliding Wear Behavior of Spark Plasma Sintered Fe-Based Bulk Metallic Glass/Graphite Composites

    Directory of Open Access Journals (Sweden)

    Xiulin Ji

    2016-09-01

    Full Text Available Bulk metallic glass (BMG and BMG-graphite composites were fabricated using spark plasma sintering at the sintering temperature of 575 °C and holding time of 15 min. The sintered composites exhibited partial crystallization and the presence of distributed porosity and graphite particles. The effect of graphite reinforcement on the tribological properties of the BMG/graphite composites was investigated using dry ball-on-disc sliding wear tests. The reinforcement of graphite resulted in a reduction in both the wear rate and the coefficient of friction as compared to monolithic BMG samples. The wear surfaces of BMG/graphite composites showed regions of localized wear loss due to microcracking and fracture, as was also the case with the regions covered with graphite-rich protective film due to smearing of pulled off graphite particles.

  12. Formation and structure of composite coating of HDA and micro-plasma oxidation on A3 steel

    Institute of Scientific and Technical Information of China (English)

    YU Sheng-xue; XIA Yuan; CHEN Ling; GUAN Yong-jun; YAO Mei

    2004-01-01

    Composite coatings were obtained on A3 steel by hot dipping aluminum(HDA) at 720 ℃ for 6 min and micro-plasma oxidation(MPO) in alkali electrolyte. The surface morphology, element distribution and interface structure of composite coatings were studied by means of XRD, SEM and EDS. The results show that the composite coatings obtained through HDA/MPO on A3 steel consist of four layers. From the surface to the substrate, the layer is loose Al2O3 ceramic, compact Al2O3 ceramic, Al and FeAl intermetallic compound layer in turn. The adhesions among all the layers are strengthened because the ceramic layer formed at the Al surface originally, FeAl intermetallic compound layer and substrate are combined in metallurgical form through mutual diffusion during HDA process.Initial experiment results disclose that the anti-corrosion performance and wear resistance of composite coating are obviously improved through HDA/MPO treatment.

  13. Temperature Measurement Challenges and Limitations for In-Flight Particles in Suspension Plasma Spraying

    Science.gov (United States)

    Aziz, Bishoy; Gougeon, Patrick; Moreau, Christian

    2017-03-01

    Suspension plasma spraying (SPS) acquires a significant interest from the industry. The deposited coatings using this technique were proved to have unique microstructural features compared to those built by conventional plasma spraying techniques. In order to optimize this process, in-flight particle diagnostics is considered a very useful tool that helps to control various spraying parameters and permits better coating reproducibility. In that context, the temperature of in-flight particles is one of the most important key elements that helps to optimize and control the SPS process. However, the limitations and challenges associated with this process have a significant effect on the accuracy of two-color pyrometric techniques used to measure the in-flight particle temperature. In this work, the influence of several nonthermal radiation sources on the particle temperature measurement is studied. The plasma radiation scattered by in-flight particles was found to have no significant influence on temperature measurement. Moreover, the detection of the two-color signals at two different locations was found to induce a significant error on temperature measurement. Finally, the plasma radiation surrounding the in-flight particles was identified as the main source of error on the temperature measurement of in-flight particles.

  14. Real-time dielectric-film thickness measurement system for plasma processing chamber wall monitoring.

    Science.gov (United States)

    Kim, Jin-Yong; Chung, Chin-Wook

    2015-12-01

    An in-situ real-time processing chamber wall monitoring system was developed. In order to measure the thickness of the dielectric film, two frequencies of small sinusoidal voltage (∼1 V) signals were applied to an electrically floated planar type probe, which is positioned at chamber wall surface, and the amplitudes of the currents and the phase differences between the voltage and current were measured. By using an equivalent sheath circuit model including a sheath capacitance, the dielectric thickness can be obtained. Experiments were performed in various plasma condition, and reliable dielectric film thickness was obtained regardless of the plasma properties. In addition, availability in commercial chamber for plasma enhanced chemical vapor deposition was verified. This study is expected to contribute to the control of etching and deposition processes and optimization of periodic maintenance in semiconductor manufacturing process.

  15. Simulation of vibration-induced effect on plasma current measurement using a fiber optic current sensor.

    Science.gov (United States)

    Descamps, Frédéric; Aerssens, Matthieu; Gusarov, Andrei; Mégret, Patrice; Massaut, Vincent; Wuilpart, Marc

    2014-06-16

    An accurate measurement of the plasma current is of paramount importance for controlling the plasma magnetic equilibrium in tokamaks. Fiber optic current sensor (FOCS) technology is expected to be implemented to perform this task in ITER. However, during ITER operation, the vessel and the sensing fiber will be subject to vibrations and thus to time-dependent parasitic birefringence, which may significantly compromise the FOCS performance. In this paper we investigate the effects of vibrations on the plasma current measurement accuracy under ITER-relevant conditions. The simulation results show that in the case of a FOCS reflection scheme including a spun fiber and a Faraday mirror, the error induced by the vibrations is acceptable regarding the ITER current diagnostics requirements.

  16. Structure and Composition Measurements in Equatorial Ionospheric Bubbles.

    Science.gov (United States)

    1980-07-09

    raI IIrregularities processes Ion 02ni posit 202 5z ADS--.A ’ --- .... .. 0 d.I -1 -f,d sdontv III 1,11 - lcA eIrp, ’ IAo mnulti -instrumeonted Terrier...instrumented Terrier Alalemute rockets each with a plasma diagnostics complement of plasma probes, ion mass spectrometer, electric field sensors and a four...OSE COME 0 FIRE SET 52 Bsec 103 km SRI BEACON STA 84 -- j-PLD SEP JOINT J AFT E-FLD BOOMS SRI ANTENNA PLO SEP SPRINGS MALEMUTE MOTOR DNA/KWAJALEIN f

  17. Charge exchange fast neutral measurement with natural diamond detectors in neon plasma on LHD

    Science.gov (United States)

    Saida, T.; Sasao, M.; Isobe, M.; Krasilnikov, A. V.

    2003-03-01

    Charge exchange (CX) fast neutral spectra produced by ion cyclotron resonance frequency hydrogen minority heating in neon and helium majority plasmas sustained by neutral beam injection were measured with perpendicular Natural Diamond Detectors during the fifth campaign in 2002 on large helical devices (LHDs). It was observed that there were differences between fast neutral spectra shapes in neon plasma and those in helium of the same discharge condition with similar plasma parameters. Dominant CX processes in neon and helium plasmas were studied for ionization components from outside of the last closed flux surface. High-energy proton spectra were obtained by taking account of each charge state distribution and responsible charge exchange cross sections. The high-energy proton tail formations in both plasmas were similar for the same heating regime. The relaxation time tendencies of the effective temperatures of a high-energy proton have also shown no differences, indicating that the acceleration and confinement of energetic ions in LHDs are similar in neon and helium plasmas.

  18. Spatial distribution of low-energy plasma around comet 67P/CG from Rosetta measurements

    CERN Document Server

    Edberg, N J T; Odelstad, E; Henri, P; Lebreton, J -P; Gasc, S; Rubin, M; André, M; Gill, R; Johansson, E P G; Johansson, F; Vigren, E; Wahlund, J E; Carr, C M; Cupido, E; Glassmeier, K -H; Goldstein, R; Koenders, C; Mandt, K; Nemeth, Z; Nilsson, H; Richter, I; Wieser, G Stenberg; Szego, K; Volwerk, M

    2016-01-01

    We use measurements from the Rosetta plasma consortium (RPC) Langmuir probe (LAP) and mutual impedance probe (MIP) to study the spatial distribution of low-energy plasma in the near-nucleus coma of comet 67P/Churyumov-Gerasimenko. The spatial distribution is highly structured with the highest density in the summer hemisphere and above the region connecting the two main lobes of the comet, i.e. the neck region. There is a clear correlation with the neutral density and the plasma to neutral density ratio is found to be about 1-2x10^-6, at a cometocentric distance of 10 km and at 3.1 AU from the sun. A clear 6.2 h modulation of the plasma is seen as the neck is exposed twice per rotation. The electron density of the collisonless plasma within 260 km from the nucleus falls of with radial distance as about 1/r. The spatial structure indicates that local ionization of neutral gas is the dominant source of low-energy plasma around the comet.

  19. Electrostatic Probe with Shielded Probe Insulator Tube for Low Disturbing Plasma Measurements in Hall Thrusters

    Energy Technology Data Exchange (ETDEWEB)

    D. Staack, Y. Raitses, and N.J. Fisch

    2003-07-10

    Electrostatic probes are widely used to measure spatial plasma parameters of the quasi-neutral plasma in Hall thrusters and similar ExB electric discharge devices. Significant perturbations of the plasma, induced by such probes, can mask the actual physics involved in operation of these devices. In Hall thrusters, probe-induced perturbations can produce changes in the discharge current and plasma parameters on the order of their steady state values. These perturbations are explored by varying the material, penetration distance, and residence time of various probe designs. A possible cause of these perturbations appears to be the secondary electron emission, induced by energetic plasma electrons, from insulator ceramic tubes in which the probe wire is inserted. A new probe in which a low secondary electron emission material, such as metal, shields the probe ceramic tube, is shown to function without producing such large perturbations. A segmentation of this shield further prevents probe -induced perturbations, by not shortening the plasma through the conductive shield. In a set of experiments with a segmented shield probe, the thruster was operated in the input power range of 500-2.5 kW and discharge voltages of 200-500 V, while the probe-induced perturbations of the discharge current were below 4% of its steady state value in the region in which 90% of the voltage drop takes place.

  20. A Novel Spectrometer for Measuring Laser-Produced Plasma X-Ray in Inertial Confinement Fusion

    Directory of Open Access Journals (Sweden)

    Zhu Gang

    2012-01-01

    Full Text Available In the experimental investigations of inertial confinement fusion, the laser-produced high-temperature plasma contains very abundant information, such as the electron temperature and density, ionization. In order to diagnose laser-plasma distribution in space and evolution in time, an elliptical curved crystal spectrometer has been developed and applied to diagnose X-ray of laser-produced plasma in 0.2~2.46 nm region. According to the theory of Bragg diffraction, four kinds of crystal including LiF, PET, MiCa, and KAP were chosen as dispersive elements. The distance of crystal lattice varies from 0.4 to 2.6 nm. Bragg angle is in the range of 30°~67.5°, and the spectral detection angle is in 55.4°~134°. The curved crystal spectrometer mainly consists of elliptical curved crystal analyzer, vacuum configuration, aligning device, spectral detectors and three-dimensional microadjustment devices. The spectrographic experiment was carried out on the XG-2 laser facility. Emission spectrum of Al plasmas, Ti plasma, and Au plasmas have been successfully recorded by using X-ray CCD camera. It is demonstrated experimentally that the measured wavelength is accorded with the theoretical value.