WorldWideScience

Sample records for previous dusty plasma

  1. ''Dusty plasmas''

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Bingham, R.; Angelis, U. de

    1989-09-01

    The field of ''dusty plasmas'' promises to be a very rewarding topic of research for the next decade or so, not only from the academic point of view where the emphasis is on developing the theory of the often complex collective and non-linear processes, but also from the point of view of applications in astrophysics, space physics, environmental and energy research. In this ''comment'' we should like to sketch the current development of this fast growing and potentially very important research area. We will discuss the new features of ''dusty'' plasmas in the most general terms and then briefly mention some successful applications and effects which have already been examined. (author)

  2. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  3. Dusty-Plasma Particle Accelerator

    Science.gov (United States)

    Foster, John E.

    2005-01-01

    A dusty-plasma apparatus is being investigated as means of accelerating nanometer- and micrometer-sized particles. Applications for the dusty-plasma particle accelerators fall into two classes: Simulation of a variety of rapidly moving dust particles and micrometeoroids in outer-space environments that include micrometeoroid streams, comet tails, planetary rings, and nebulae and Deposition or implantation of nanoparticles on substrates for diverse industrial purposes that could include hardening, increasing thermal insulation, altering optical properties, and/or increasing permittivities of substrate materials. Relative to prior apparatuses used for similar applications, dusty-plasma particle accelerators offer such potential advantages as smaller size, lower cost, less complexity, and increased particle flux densities. A dusty-plasma particle accelerator exploits the fact that an isolated particle immersed in plasma acquires a net electric charge that depends on the relative mobilities of electrons and ions. Typically, a particle that is immersed in a low-temperature, partially ionized gas, wherein the average kinetic energy of electrons exceeds that of ions, causes the particle to become negatively charged. The particle can then be accelerated by applying an appropriate electric field. A dusty-plasma particle accelerator (see figure) includes a plasma source such as a radio-frequency induction discharge apparatus containing (1) a shallow cup with a biasable electrode to hold the particles to be accelerated and (2) a holder for the substrate on which the particles are to impinge. Depending on the specific design, a pair of electrostatic-acceleration grids between the substrate and discharge plasma can be used to both collimate and further accelerate particles exiting the particle holder. Once exposed to the discharge plasma, the particles in the cup quickly acquire a negative charge. Application of a negative voltage pulse to the biasable electrode results in the

  4. Theory of Space Dusty Plasma

    Science.gov (United States)

    Mendis, A.

    2012-12-01

    Ionized gases, contaminated with fine (nanometer to micrometer-sized) charged dust, loosely referred to a dusty plasmas, occur in a wide variety of cosmic and laboratory environments. In this topical review I will discuss the underlying theory of such plasmas, with emphasis on the space environment. Central to the discussion is the electrostatic charging of the dust grains by the various currents that they experience in the plasma and radiative environment in which they are immersed. This charging could lead to both physical and dynamical consequences for the dust as well as for the plasma. Among the physical effects for the dust are electrostatic disruption and electrostatic levitation from charged surfaces. The dynamics of the charged dust is affected by the Lorentz force they experience, since space plasmas are generally magnetized. The physical effects for plasma result from the fact that the dust can act both as a sink and as a source of electrons in different space environments. The dynamical effects on the plasma arise from the fact that the charged dust can alter the phase velocity of normal wave modes (e.g., the Ion acoustic mode) by changing the charge equilibrium in the plasma. Additionally the charged dust can also participate in the wave dynamics, leading, for example, to the very low frequency, novel, "dust-acoustic" wave that has been observed in the laboratory. Finally the possibility that charged dust in a space plasma, may indirectly influence the propagation of electromagnetic radiation through it, will also be, briefly, discussed.

  5. Screening length in dusty plasma crystals

    International Nuclear Information System (INIS)

    Nikolaev, V S; Timofeev, A V

    2016-01-01

    Particles interaction and value of the screening length in dusty plasma systems are of great interest in dusty plasma area. Three inter-particle potentials (Debye potential, Gurevich potential and interaction potential in the weakly collisional regime) are used to solve equilibrium equations for two dusty particles suspended in a parabolic trap. The inter-particle distance dependence on screening length, trap parameter and particle charge is obtained. The functional form of inter-particle distance dependence on ion temperature is investigated and compared with experimental data at 200-300 K in order to test used potentials applicability to dusty plasma systems at room temperatures. The preference is given to the Yukawa-type potential including effective values of particle charge and screening length. The estimated effective value of the screening length is 5-15 times larger than the Debye length. (paper)

  6. ICPP: Introduction to Dusty Plasma Physics

    Science.gov (United States)

    Kant Shukla, Padma

    2000-10-01

    Two omnipresent ingredients of the Universe are plasmas and charged dust. The interplay between these two has opened up a new and fascinating research area, that of dusty plasmas, which are ubiquitous in in different parts of our solar system, namely planetary rings, circumsolar dust rings, interplanetary medium, cometary comae and tails, interstellar molecular clouds, etc. Dusty plasmas also occur in noctilucent clouds in the arctic troposphere and mesosphere, cloud-to-ground lightening in thunderstorms containing smoke-contaminated air over the US, in the flame of humble candle, as well as in microelectronics and in low-temperature laboratory discharges. In the latter, charged dust grains are strongly correlated. Dusty plasma physics has appeared as one of the most rapidly growing field of science, besides the field of the Bose-Einstein condensate, as demonstrated by the number of published papers in scientific journals and conference proceedings. In fact, it is a truly interdisciplinary science because it has many potential applications in astrophysics (viz. in understanding the formation of dust clusters and structures, instabilities of interstellar molecular clouds and star formation, decoupling of magnetic fields from plasmas, etc.) as well as in the planetary magnetospheres of our solar system [viz. the Saturn (particularly, the physics of spokes and braids in B and F rings), Jupiter, Uranus, Neptune, and Mars] and in strongly coupled laboratory dusty plasmas. Since dusty plasma system involves the charging and the dynamics of extremely massive charged dust particulates, it can be characterized as a complex plasma system with new physics insights. In this talk, I shall describe the basic physics of dusty plasmas and present the status of numerous collective processes that are relevant to space research and laboratory experiments. The focus will be on theoretical and experimental observations of novel waves and instabilities, various forces, and some

  7. A survey of dusty plasma physics

    Science.gov (United States)

    Shukla, P. K.

    2001-05-01

    Two omnipresent ingredients of the Universe are plasmas and charged dust. The interplay between these two has opened up a new and fascinating research area, that of dusty plasmas, which are ubiquitous in different parts of our solar system, namely planetary rings, circumsolar dust rings, the interplanetary medium, cometary comae and tails, as well as in interstellar molecular clouds, etc. Dusty plasmas also occur in noctilucent clouds in the arctic troposphere and mesosphere, cloud-to-ground lightening in thunderstorms containing smoke-contaminated air over the United States, in the flame of a humble candle, as well as in microelectronic processing devices, in low-temperature laboratory discharges, and in tokamaks. Dusty plasma physics has appeared as one of the most rapidly growing fields of science, besides the field of the Bose-Einstein condensate, as demonstrated by the number of published papers in scientific journals and conference proceedings. In fact, it is a truly interdisciplinary science because it has many potential applications in astrophysics (viz. in understanding the formation of dust clusters and structures, instabilities of interstellar molecular clouds and star formation, decoupling of magnetic fields from plasmas, etc.) as well as in the planetary magnetospheres of our solar system [viz. Saturn (particularly, the physics of spokes and braids in the B and F rings), Jupiter, Uranus, Neptune, and Mars] and in strongly coupled laboratory dusty plasmas. Since a dusty plasma system involves the charging and dynamics of massive charged dust grains, it can be characterized as a complex plasma system providing new physics insights. In this paper, the basic physics of dusty plasmas as well as numerous collective processes are discussed. The focus will be on theoretical and experimental observations of charging processes, waves and instabilities, associated forces, the dynamics of rotating and elongated dust grains, and some nonlinear structures (such as

  8. The magnetized dusty plasma experiment (MDPX)

    Science.gov (United States)

    Thomas, E.; Konopka, U.; Artis, D.; Lynch, B.; Leblanc, S.; Adams, S.; Merlino, R. L.; Rosenberg, M.

    2015-04-01

    The magnetized dusty plasma experiment (MDPX) is a newly commissioned plasma device that started operations in late spring, 2014. The research activities of this device are focused on the study of the physics, highly magnetized plasmas, and magnetized dusty plasmas. The design of the MDPX device is centered on two main components: an open bore, superconducting magnet that is designed to produce, in a steady state, both uniform magnetic fields up to 4 Tesla and non-uniform magnetic fields with gradients of 1-2 T m-1 and a flexible, removable, octagonal vacuum chamber that provides substantial probe and optical access to the plasma. This paper will provide a review of the design criteria for the MDPX device, a description of the research objectives, and brief discussion of the research opportunities offered by this multi-institution, multi-user project.

  9. Electron "bite-outs" in Dusty Plasmas

    Science.gov (United States)

    Horanyi, M.; Hsu, S.; Kempf, S.

    2012-12-01

    The study of dusty plasmas is still an emerging new field that bridges a number of traditionally separate subjects, including for example, celestial mechanics, and plasma physics. Dust particles immersed in plasmas and UV radiation collect electrostatic charges and respond to electromagnetic forces in addition to all the other forces acting on uncharged grains. Simultaneously, dust can alter its plasma environment. Dust particles in plasmas are unusual charge carriers. They are many orders of magnitude heavier than any other plasma particles, and they can have many orders of magnitude larger (negative or positive) time-dependent charges. Dust particles can communicate non-electromagnetic effects (gravity, drag, radiation pressure) to the plasma that can represent new free energy sources. Their presence can influence the collective plasma behavior, for example, by altering the traditional plasma wave modes and by triggering new types of waves and instabilities. Dusty plasmas represent the most general form of space, laboratory, and industrial plasmas. Interplanetary space, comets, planetary rings, asteroids, the Moon, aerosols in the atmosphere, are all examples where electrons, ions, and dust particles coexist. This talk will focus on "electron bite-outs", the apparent reduction of the electron density due to dust charging in a plasma comprised of electrons, ions and dust particles We will compare the recent observations of the plasma conditions near Enceladus at Saturn to the decades old measurements in the Earth's mesosphere. We present model calculations of dust charging in a region where plasma is maintained by UV radiation, and present the time-dependent charge distribution of grains as function of dust density and size distribution. We will also make estimates for possible dusty plasma wave activities as function of the magnitude of the electron "bite-outs".

  10. RF attenuation as a dusty plasma diagnostic

    Science.gov (United States)

    Doyle, Brandon; Konopka, Uwe; Thomas, Edward

    2017-10-01

    When a dusty plasma is formed by adding dust to a plasma environment, the electron density of the background plasma is depleted as the dust particles acquire their negative charge. The magnitude of the electron depletion depends on the dust particle charge, and thus its properties, as well as the dust number density. A direct measurement of the electron density in a dusty plasma therefore contains information about the charging state of the dust particles. This measurement is difficult to obtain without influencing the system. For example, Langmuir probes influence the system by creating voids, or they become unreliable due to their potential contamination with dust. A less invasive diagnostic tool might be realized using plasma chamber electrodes for a plasma impedance measurement as it depends on the excitation frequency: the spatially averaged electron density is derived from the electron plasma frequency, which is related to the radio frequency attenuation characteristic. We present preliminary experiments using two impedance probe designs: probes immersed in a plasma and electrodes located at the edge of the plasma. We evaluate the potential application of this method for ground-based laboratory experiments and future microgravity experiment facilities aboard the ISS. This work was supported by JPL/NASA (JPL-RSA 1571699) the US Dept. of Energy (DE-SC0016330) and NSF (PHY-1613087).

  11. Nanodiamonds in dusty low-pressure plasmas

    International Nuclear Information System (INIS)

    Vandenbulcke, L.; Gries, T.; Rouzaud, J. N.

    2009-01-01

    Dusty plasmas composed of carbon, hydrogen, and oxygen have been evidenced by optical emission spectroscopy and microwave interferometry, due to the increase in electron energy and the decrease in electron density. These plasmas allow homogeneous synthesis of nanodiamond grains composed of either pure diamond nanocrystals only (2-10 nm in size) or of diamond nanocrystals and some sp 2 -hybridized carbon entities. The control of their size and their microstructure could open ways for a wide range of fields. Their formation from a plasma-activated gaseous phase is also attractive because the formation of nanodiamonds in the universe is still a matter of controversy

  12. Progress in the study of dusty plasmas

    International Nuclear Information System (INIS)

    Mendis, D A

    2002-01-01

    While the study of dust-plasma interactions is by no means new, early progress in the field was slow and uneven. It received a major boost in the early 1980s with the Voyager spacecraft observations of peculiar features in the Saturnian ring system (e.g. the 'radial spokes') which could not be explained by gravitation alone and led to the development of the gravito-electrodynamic theory of dust dynamics. This theory scored another major success more recently in providing the only possible explanation of collimated high-speed beams of fine dust particles observed to sporadically emanate from Jupiter by the Ulysses and Galileo spacecrafts. These dynamical studies were complimented in the early 1990s by the study of collective processes in dusty plasmas. Not only has this led to the discovery of a whole slew of new wave modes and instabilities with wide ranging consequences for the space environment, it also spurred laboratory studies leading to the observation of several of them, including the very low frequency dust acoustic mode, which can be made strikingly visual by laser light scattering off the dust. The most fascinating new development in dusty plasmas, which occurred about 7 years ago, was the crystallization of dusty plasmas in several laboratories. In these so-called 'plasma crystals', micrometre-sized dust, which are either externally introduced or internally grown in the plasma, acquire large negative charges and form Coulomb lattices as was theoretically anticipated for some time. This entirely new material, whose crystalline structure is so strikingly observed by laser light scattering, could be a valuable tool for studying physical processes in condensed matter, such as melting, annealing and lattice defects. Recognizing the crucial role of gravity on the crystal structure, microgravity experiments have already been performed in aircraft, sounding rockets, the Mir Space Station, and most recently in the International Space Station, leading to

  13. Kadomstev–Petviashvili (KP) equation in warm dusty plasma with ...

    Indian Academy of Sciences (India)

    In this work, the propagation of nonlinear waves in warm dusty plasmas with ... Mamun et al [7] have also derived rarefactive solitary waves in low-temperature dusty plasmas such as those in laboratory and astrophysical environments. ... plasma environments that clearly indicate the presence of nonthermal electron pop-.

  14. Grain charging in dusty plasmas (Invited)

    Science.gov (United States)

    Horanyi, M.

    2013-12-01

    Dusty plasmas represent the most general form of space, laboratory, and industrial plasmas. Interplanetary space, comets, planetary rings, asteroids, and aerosols in the atmosphere, are all examples where electrons, ions, and dust particles coexist. Dust particles immersed in plasmas and UV radiation collect electrostatic charges and respond to electromagnetic forces in addition to all the other forces acting on uncharged grains. Simultaneously, dust can alter its plasma environment. Dust particles in plasmas are unusual charge carriers. They are many orders of magnitude heavier than any other plasma particles, and they can have many orders of magnitude larger (negative or positive) time-dependent charges. The presence of dust can influence the collective plasma behavior, for example, by altering the traditional plasma wave modes and by triggering new types of waves and instabilities. This talk will focus on the charging processes, including the collection of electrons and ions in multi-species plasmas, and discuss the expected charge distribution on the dust particles as function of their size, and the dust density itself. Examples where these effects could result in novel plasma physics phenomena include Noctilucent clouds, and comets.

  15. Dissipative drift instability in dusty plasma

    Directory of Open Access Journals (Sweden)

    Nilakshi Das

    2012-03-01

    Full Text Available An investigation has been done on the very low-frequency electrostatic drift waves in a collisional dusty plasma. The dust density gradient is taken perpendicular to the magnetic field B0⃗, which causes the drift wave. In this case, low-frequency drift instabilities can be driven by E1⃗×B0⃗ and diamagnetic drifts, where E1⃗ is the perturbed electric field. Dust charge fluctuation is also taken into consideration for our study. The dust- neutral and ion-neutral collision terms have been included in equations of motion. It is seen that the low-frequency drift instability gets damped in such a system. Both dust charging and collision of plasma particles with the neutrals may be responsible for the damping of the wave. Both analytical and numerical techniques have been used while developing the theory.

  16. Ion-acoustic solitons in dusty plasma

    Science.gov (United States)

    Losseva, T. V.; Popel, S. I.; Golub', A. P.

    2012-09-01

    The dynamics of dust ion-acoustic solitons is analyzed in a wide range of dusty plasma parameters. The cases of both a positive dust grain charge arising due to the photoelectric effect caused by intense electromagnetic radiation and a negative grain charge established in the absence of electromagnetic radiation are considered. The ranges of plasma parameters and Mach numbers in which "conservative" (nondissipative) solitons can exist are determined. It is shown that, in dusty plasma with negatively charged dust grains, both compression and rarefaction solitons can propagate, whereas in plasma with positively charged dust grains, only compression solitons can exist. The evolution of soliton-like compression and rarefaction perturbations is studied by numerically solving the hydrodynamic equations for ions and dust grains, as well as the equation for dust grain charging. The main dissipation mechanisms, such as grain charging, ion absorption by dust grains, momentum exchange between ions and dust grains, and ion-neutral collisions are taken into account. It is shown that the amplitudes of soliton-like compression and rarefaction perturbations decrease in the course of their evolution and their velocities (the Mach numbers) decrease monotonically in time. At any instant of time, the shape of an evolving soliton-like perturbation coincides with the shape of a conservative soliton corresponding to the current value of the Mach number. It is shown that, after the interaction between any types of soliton-like perturbations, their velocities and shapes are restored (with a certain phase shift) to those of the corresponding perturbations propagating without interaction; i.e., they are in fact weakly dissipative solitons.

  17. Parametric instabilities in magnetized bi-ion and dusty plasmas

    Indian Academy of Sciences (India)

    -ion or dusty plasma with parametric pumping of the magnetic field is analysed. The equation of motion governing the perturbed plasma is derived and parametrically excited transverse modes propagating along the magnetic field are found.

  18. Collisional Effect On Magnetosonic Solitons In A Dusty Plasma Slab ...

    African Journals Online (AJOL)

    An analytical investigation of collisional effect on magnetosonic solitons in a dusty plasma slab is presented. We have derived and presented solutions of nonlinear magetohydrodynamic equations for a warm dusty magnetoplasma. It is observed that, our work could be considered a general case for magnetosonic solutions ...

  19. Modelling of dusty plasma properties by computer simulation methods

    Energy Technology Data Exchange (ETDEWEB)

    Baimbetov, F B [IETP, Al Farabi Kazakh National University, 96a, Tole bi St, Almaty 050012 (Kazakhstan); Ramazanov, T S [IETP, Al Farabi Kazakh National University, 96a, Tole bi St, Almaty 050012 (Kazakhstan); Dzhumagulova, K N [IETP, Al Farabi Kazakh National University, 96a, Tole bi St, Almaty 050012 (Kazakhstan); Kadyrsizov, E R [Institute for High Energy Densities of RAS, Izhorskaya 13/19, Moscow 125412 (Russian Federation); Petrov, O F [IETP, Al Farabi Kazakh National University, 96a, Tole bi St, Almaty 050012 (Kazakhstan); Gavrikov, A V [IETP, Al Farabi Kazakh National University, 96a, Tole bi St, Almaty 050012 (Kazakhstan)

    2006-04-28

    Computer simulation of dusty plasma properties is performed. The radial distribution functions, the diffusion coefficient are calculated on the basis of the Langevin dynamics. A comparison with the experimental data is made.

  20. Ideal gas behavior of a strongly coupled complex (dusty) plasma.

    Science.gov (United States)

    Oxtoby, Neil P; Griffith, Elias J; Durniak, Céline; Ralph, Jason F; Samsonov, Dmitry

    2013-07-05

    In a laboratory, a two-dimensional complex (dusty) plasma consists of a low-density ionized gas containing a confined suspension of Yukawa-coupled plastic microspheres. For an initial crystal-like form, we report ideal gas behavior in this strongly coupled system during shock-wave experiments. This evidence supports the use of the ideal gas law as the equation of state for soft crystals such as those formed by dusty plasmas.

  1. Linear and Nonlinear Electrostatic Waves in Unmagnetized Dusty Plasmas

    International Nuclear Information System (INIS)

    Mamun, A. A.; Shukla, P. K.

    2010-01-01

    A rigorous and systematic theoretical study has been made of linear and nonlinear electrostatic waves propagating in unmagnetized dusty plasmas. The basic features of linear and nonlinear electrostatic waves (particularly, dust-ion-acoustic and dust-acoustic waves) for different space and laboratory dusty plasma conditions are described. The experimental observations of such linear and nonlinear features of dust-ion-acoustic and dust-acoustic waves are briefly discussed.

  2. Nonlinear screening of dust grains and structurization of dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Tsytovich, V. N., E-mail: tsytov@lpi.ru; Gusein-zade, N. G. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2013-07-15

    equilibrium between plasma components when analyzing equilibrium structures. The effect of plasma screening nonlinearity on both the diffusion processes and the forces of dust drag by plasma fluxes is analyzed. It is shown how self-organized dust structures form in these processes. In the limit of very small dust grain charges, the forces acting on the dusty plasma components and the set of basic equations for stationary dust structures (with allowance for nonlinear screening) take a standard form. New qualitative effects, such as the suppression of diffusion due to ion scattering from dust grains and the formation of structures of different configurations, are described. A detailed comparison with previous results is performed. It is shown that the solution of basic nonlinear equations for dust structures yields new qualitative effects. A number of new effects to be studied in future dusty plasma experiments with the formation of structures in spherical chambers are predicted (it is assumed that diffusion will play a significant role under microgravity conditions). Recent ground-based experiments, as well as experiments carried out onboard the International Space Station, directly confirm the nonlinear character of screening and the significant role played by this nonlinearity in the structurization of dusty plasma. Experiments on the formation of structures consisting of smaller dust grains within structures formed of larger grains are discussed. It is shown that those experiments can be interpreted only using the concept of nonlinear screening.

  3. Complex and Dusty Plasmas From Laboratory to Space

    CERN Document Server

    Fortov, Vladimir E

    2009-01-01

    Dusty or complex plasmas are plasmas containing solid or liquid charged particles referred to as dust. Naturally occurring in space, on earth dust plays a key role in plasma applications associated with etching technologies in microelectronics. International in scope, this volume covers theoretical and application research.

  4. Jeans instability of an inhomogeneous streaming dusty plasma

    Indian Academy of Sciences (India)

    Abstract. The dynamics of a self-gravitating unmagnetized, inhomogeneous, streaming dusty plasma is studied in the present work. The presence of the shear flow causes the coupling between gravitational and electrostatic forces. In the absence of self-gravity, the fluctuations in the plasma may grow at the expense of the ...

  5. Parametric instabilities in magnetized bi-ion and dusty plasmas

    Indian Academy of Sciences (India)

    Email: n.cramer@physics.usyd.edu.au. MS received 1 April 2003; accepted 31 July 2003. Abstract. The excitation of low frequency modes of oscillations in a magnetized bi-ion or dusty plasma with parametric pumping of the magnetic field is analysed. The equation of motion governing the perturbed plasma is derived and ...

  6. Parametric instabilities in magnetized bi-ion and dusty plasmas

    Indian Academy of Sciences (India)

    The excitation of low frequency modes of oscillations in a magnetized bi-ion or dusty plasma with parametric pumping of the magnetic field is analysed. The equation of motion governing the perturbed plasma is derived and parametrically excited transverse modes propagating along the magnetic field are found.

  7. Jeans instability of an inhomogeneous streaming dusty plasma

    Indian Academy of Sciences (India)

    The dynamics of a self-gravitating unmagnetized, inhomogeneous, streaming dusty plasma is studied in the present work. The presence of the shear flow causes the coupling between gravitational and electrostatic forces. In the absence of self-gravity, the fluctuations in the plasma may grow at the expense of the density ...

  8. Electrostatic sheath at the boundary of a collisional dusty plasma

    Indian Academy of Sciences (India)

    Abstract. Considering the Boltzmann response of the ions and electrons in plasma dynamics and inertial dynamics of the dust charged grains in a highly collisional dusty plasma, the nature of the electrostatic potential near a boundary is investigated. Based on the fluid approximation, the forma- tion as well as the ...

  9. Electrostatic sheath at the boundary of a collisional dusty plasma

    Indian Academy of Sciences (India)

    Department of Physics, Cotton College, Guwahati 781 001, India. Abstract. Considering the Boltzmann response of the ions ... respect to normal electronic charge (q ~105. –106e). The mass of the dust grains can have very high value too, up to ... degrees of plasma dynamics. Thus, the theoretical modeling of a dusty plasma ...

  10. Driven transverse shear waves in a strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    Bandyopadhyay, P.; Prasad, G.; Sen, A.; Kaw, P.K.

    2008-01-01

    The linear dispersion properties of transverse shear waves in a strongly coupled dusty plasma are experimentally studied in a DC discharge device by exciting them in a controlled manner with a variable frequency external source. The dusty plasma is maintained in the strongly coupled fluid regime with (1 c ) where Γ is the Coulomb coupling parameter and Γ c is the crystallization limit. A dispersion relation for the transverse waves is experimentally obtained over a frequency range of 0.1 Hz to 2 Hz and found to show good agreement with viscoelastic theoretical results

  11. Stimulated brillouin scattering of electromagnetic waves in a dusty plasma

    International Nuclear Information System (INIS)

    Salimullah, M.; Sen, A.

    1991-08-01

    The stimulated Brilluoin scattering of electromagnetic waves in a homogeneous, unmagnetized and collisionless dusty plasma has been investigated theoretically. The Vlasov equation has been solved perturbatively to find the nonlinear response of the plasma particles. The presence of the dust particles introduces a background inhomogeneous electric field which significantly influences the dispersive properties of the plasma. At the ion acoustic branch we find the usual scattering slightly modified by the charged dust grains. However, at the frequency lower than the ion acoustic branch we find a new mode of the plasma arising from the oscillations of the ions in the static structure of the dust distribution. This low frequency branch causes enhanced stimulated Brillouin scattering of electromagnetic waves in a dusty plasma. (author). 15 refs

  12. Application of tomographic particle image velocimetry to complex (dusty) plasmas

    International Nuclear Information System (INIS)

    Williams, Jeremiah

    2011-01-01

    Over the past decade, particle image velocimetry (PIV) techniques have been used to obtain detailed measurements of the thermal and transport properties of weakly-coupled dusty plasmas. This paper reports on the application of an extension of these techniques, tomographic PIV (tom-PIV), which provides an instantaneous volumetric measurement of the particle transport.

  13. The Bohm criterion for a dusty plasma sheath

    Indian Academy of Sciences (India)

    Abstract. The formation of the sheath in a dusty plasma is investigated. The Bohm criterion is derived for two different cases: (a) when electrons are in thermodynamic equilibrium and dust grains provide the immobile, stationary background and (b) when both electrons and ions are in thermodynamic equilibrium and dust ...

  14. Three-dimensional wake potential in a streaming dusty plasma

    Indian Academy of Sciences (India)

    £School of Studies in Physics, Vikram University, Ujjain 456 010, India. MS received 27 December ... to be streaming with uniform velocities u0 and v0, respectively in the presence of a self- consistent constant ... static mode (ω,k) in a uniform dusty plasma whose response function is given by ε(ω,k). (eq. (1)), is given by [17 ...

  15. Kadomstev–Petviashvili (KP) equation in warm dusty plasma with ...

    Indian Academy of Sciences (India)

    In this work, the propagation of nonlinear waves in warm dusty plasmas with variable dust charge, two-temperature ion and nonthermal electron is studied. By using the reductive perturbation theory, the Kadomstev–Petviashvili (KP) equation is derived. The energy of the soliton and the linear dispersion relation are obtained ...

  16. Electrostatic twisted modes in multi-component dusty plasmas

    International Nuclear Information System (INIS)

    Ayub, M. K.; Ali, S.; Ikram, M.

    2016-01-01

    Various electrostatic twisted modes are re-investigated with finite orbital angular momentum in an unmagnetized collisionless multi-component dusty plasma, consisting of positive/negative charged dust particles, ions, and electrons. For this purpose, hydrodynamical equations are employed to obtain paraxial equations in terms of density perturbations, while assuming the Gaussian and Laguerre-Gaussian (LG) beam solutions. Specifically, approximated solutions for potential problem are studied by using the paraxial approximation and expressed the electric field components in terms of LG functions. The energy fluxes associated with these modes are computed and corresponding expressions for orbital angular momenta are derived. Numerical analyses reveal that radial/angular mode numbers as well as dust number density and dust charging states strongly modify the LG potential profiles attributed to different electrostatic modes. Our results are important for understanding particle transport and energy transfer due to wave excitations in multi-component dusty plasmas

  17. Electrostatic solitary waves in dusty pair-ion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Misra, A. P. [Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan-731 235, West Bengal (India); Adhikary, N. C. [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Vigyan Path, Paschim Boragaon, Garchuk, Guwahati-781035, Assam (India)

    2013-10-15

    The propagation of electrostatic waves in an unmagnetized collisionless pair-ion plasma with immobile positively charged dusts is studied for both large- and small-amplitude perturbations. Using a two-fluid model for pair-ions, it is shown that there appear two linear ion modes, namely the “fast” and “slow” waves in dusty pair-ion plasmas. The properties of these wave modes are studied with different mass (m) and temperature (T) ratios of negative to positive ions, as well as the effects of immobile charged dusts (δ). For large-amplitude waves, the pseudopotential approach is performed, whereas the standard reductive perturbation technique is used to study the small-amplitude Korteweg-de Vries (KdV) solitons. The profiles of the pseudopotential, the large amplitude solitons as well as the dynamical evolution of KdV solitons, are numerically studied with the system parameters as above. It is found that the pair-ion plasmas with positively charged dusts support the propagation of solitary waves (SWs) with only the negative potential. The results may be useful for the excitation of SWs in laboratory dusty pair-ion plasmas, electron-free industrial plasmas as well as for observation in space plasmas where electron density is negligibly small compared to that of negative ions.

  18. Thermal condensation mode in a dusty plasma

    Indian Academy of Sciences (India)

    associated emission nebula, escapes without being absorbed by the in-falling matter from the accretion disk, the dust grain, depending upon the thermal velocities of the background plasma particles, may pick up between 10 to 100 electronic charges from the ionized gas. [5]. Interstellar dust is heated by the absorption of ...

  19. 3+1 dimensional envelop waves and its stability in magnetized dusty plasma

    International Nuclear Information System (INIS)

    Duan Wenshan

    2006-01-01

    It is well known that there are envelope solitary waves in unmagnetized dusty plasmas which are described by a nonlinear Schrodinger equation (NLSE). A three dimension nonlinear Schrodinger equation for small but finite amplitude dust acoustic waves is first obtained for magnetized dusty plasma in this paper. It suggest that in magnetized dusty plasmas the envelope solitary waves exist. The modulational instability for three dimensional NLSE is studied as well. The regions of stability and instability are well determined in this paper

  20. Strongly coupled dusty plasmas: crystals, liquids, clusters and waves

    International Nuclear Information System (INIS)

    Jeng-Mei Liu; Wen-Tau Juan; Ju-Wang Hsu; Zen-Hong Huang; Lin I

    1999-01-01

    The dusty plasma is a system that consists of many strongly-charged fine dust particles suspended in a plasma background. The slow dynamics and strong coupling due to the large mass and charges lead to the formation of highly-ordered dust crystal structures suspended in the plasma background, which can be directly observed. The dusty plasma forms a link to the area of condensed matter physics for the study of many interesting microscopic phenomena from order to disorder. In this paper, we introduce the special properties of this system from the viewpoint of conventional plasma physics, then we briefly review past works on the structure and dynamical behaviour from the highly-ordered state, through the melting and liquid states with associated vortex-type excitation and anomalous diffusion, to the state with self-organized macroscopic dust waves after losing microscopic order. The first observation of strongly-coupled dust Coulomb clusters with small numbers of particles from a few to a few hundred, which resemble classical atoms, is also demonstrated. (author)

  1. Nonlinear localized dust acoustic waves in a charge varying dusty plasma with nonthermal ions

    International Nuclear Information System (INIS)

    Tribeche, Mouloud; Amour, Rabia

    2007-01-01

    A numerical investigation is presented to show the existence, formation, and possible realization of large-amplitude dust acoustic (DA) solitary waves in a charge varying dusty plasma with nonthermal ions. These nonlinear localized structures are self-consistent solutions of the collisionless Vlasov equation with a population of fast particles. The spatial patterns of the variable charge DA solitary wave are significantly modified by the nonthermal effects. The results complement and provide new insights into previously published results on this problem

  2. 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.

  3. Low-frequency dust-lower-hybrid modes in a dusty plasma

    International Nuclear Information System (INIS)

    Salimullah, M.

    1995-10-01

    The existence of low-frequency dust-lower-hybrid modes in a magnetized dusty plasma has been examined. These modes arise on account of the inequalities of charge and number densities of electrons, ions, and dust particles, and finite Larmor radius effects in a dusty plasma. (author). 14 refs

  4. Nonextensive dust acoustic waves in a charge varying dusty plasma

    Science.gov (United States)

    Bacha, Mustapha; Tribeche, Mouloud

    2012-01-01

    Our recent analysis on nonlinear nonextensive dust-acoustic waves (DA) [Amour and Tribeche in Phys. Plasmas 17:063702, 2010] is extended to include self-consistent nonadiabatic grain charge fluctuation. The appropriate nonextensive electron charging current is rederived based on the orbit-limited motion theory. Our results reveal that the amplitude, strength and nature of the nonlinear DA waves (solitons and shocks) are extremely sensitive to the degree of ion nonextensivity. Stronger is the electron correlation, more important is the charge variation induced nonlinear wave damping. The anomalous dissipation effects may prevail over that dispersion as the electrons evolve far away from their Maxwellian equilibrium. Our investigation may be of wide relevance to astronomers and space scientists working on interstellar dusty plasmas where nonthermal distributions are turning out to be a very common and characteristic feature.

  5. Propagation of dust electro-acoustic modes in dusty plasma

    International Nuclear Information System (INIS)

    Avinash, K.

    2001-01-01

    The propagation of the dust electro-acoustic (DEA) mode in dusty plasma with different electron and ion temperatures T e and T i and different ion species is studied. The critical ratio of the dust space charge to the ion space charge ε for the excitation of DEA mode is found to decrease with increasing T e /T i and increase with m i /m e (m i and m e are the ion and electron masses). Thus experiments with hydrogen plasma where electrons are sufficiently hotter than ions and where the reduction in the dust charge with ε is more than 50% are essential for the observation of self-shielding and the DEA mode

  6. Agglomeration processes in carbonaceous dusty plasmas, experiments and numerical simulations

    International Nuclear Information System (INIS)

    Dap, S; Hugon, R; De Poucques, L; Bougdira, J; Lacroix, D; Patisson, F

    2010-01-01

    This paper deals with carbon dust agglomeration in radio frequency acetylene/argon plasma. Two studies, an experimental and a numerical one, were carried out to model dust formation mechanisms. Firstly, in situ transmission spectroscopy of dust clouds in the visible range was performed in order to observe the main features of the agglomeration process of the produced carbonaceous dust. Secondly, numerical simulation tools dedicated to understanding the achieved experiments were developed. A first model was used for the discretization of the continuous population balance equations that characterize the dust agglomeration process. The second model is based on a Monte Carlo ray-tracing code coupled to a Mie theory calculation of dust absorption and scattering parameters. These two simulation tools were used together in order to numerically predict the light transmissivity through a dusty plasma and make comparisons with experiments.

  7. Propagation of high frequency electrostatic surface waves along the planar interface between plasma and dusty plasma

    Science.gov (United States)

    Mishra, Rinku; Dey, M.

    2018-04-01

    An analytical model is developed that explains the propagation of a high frequency electrostatic surface wave along the interface of a plasma system where semi-infinite electron-ion plasma is interfaced with semi-infinite dusty plasma. The model emphasizes that the source of such high frequency waves is inherent in the presence of ion acoustic and dust ion acoustic/dust acoustic volume waves in electron-ion plasma and dusty plasma region. Wave dispersion relation is obtained for two distinct cases and the role of plasma parameters on wave dispersion is analyzed in short and long wavelength limits. The normalized surface wave frequency is seen to grow linearly for lower wave number but becomes constant for higher wave numbers in both the cases. It is observed that the normalized frequency depends on ion plasma frequencies when dust oscillation frequency is neglected.

  8. Initial Results from the Magnetized Dusty Plasma Experiment (MDPX)

    Science.gov (United States)

    Thomas, Edward; Konopka, Uwe; Lynch, Brian; Adams, Stephen; Leblanc, Spencer; Artis, Darrick; Dubois, Ami; Merlino, Robert; Rosenberg, Marlene

    2014-10-01

    The MDPX device is envisioned as a flexible, multi-user, research instrument that can perform a wide range of studies in fundamental and applied plasma physics. The MDPX device consists of two main components. The first is a four-coil, open bore, superconducting magnet system that is designed to produce uniform magnetic fields of up to 4 Tesla and non-uniform magnetic fields with gradients up to up to 2 T/m configurations. Within the warm bore of the magnet is placed an octagonal vacuum chamber that has a 46 cm outer diameter and is 22 cm tall. The primary missions of the MDPX device are to: (1) investigate the structural, thermal, charging, and collective properties of a plasma as the electrons, ions, and finally charged microparticles become magnetized; (2) study the evolution of a dusty plasma containing magnetic particles (paramagnetic, super-paramagnetic, or ferromagnetic particles) in the presence of uniform and non-uniform magnetic fields; and, (3) explore the fundamental properties of strongly magnetized plasmas (``i.e., dust-free'' plasmas). This presentation will summarize the initial characterization of the magnetic field structure, initial plasma parameter measurements, and the development of in-situ and optical diagnostics. This work is supported by funding from the NSF and the DOE.

  9. Jeans instability of inhomogeneous dusty plasma with polarization force, ionization and recombination

    Science.gov (United States)

    Jain, Shweta; Sharma, Prerana; Chhajlani, R. K.

    2017-05-01

    The self-gravitational Jeans instability has been studied in dusty plasma containing significant background of neutral pressure and recombination of ions and electrons on the dust surface. The full dynamics of charged dust grains, ions and neutral species are employed considering the electrons as Maxwellian. We have derived the general dispersion relation for collisional dusty plasma with ionization, recombination and polarization force. The general dispersion relation describes the effects of considered parameters which are solved in different dusty plasma situations. Further, the dispersion relation is solved numerically. The present work is applicable to understand the structure formation of interstellar molecular clouds in astrophysical plasma.

  10. Jeans instability of inhomogeneous dusty plasma with polarization force, ionization and recombination

    International Nuclear Information System (INIS)

    Jain, Shweta; Sharma, Prerana; Chhajlani, R K

    2017-01-01

    The self-gravitational Jeans instability has been studied in dusty plasma containing significant background of neutral pressure and recombination of ions and electrons on the dust surface. The full dynamics of charged dust grains, ions and neutral species are employed considering the electrons as Maxwellian. We have derived the general dispersion relation for collisional dusty plasma with ionization, recombination and polarization force. The general dispersion relation describes the effects of considered parameters which are solved in different dusty plasma situations. Further, the dispersion relation is solved numerically. The present work is applicable to understand the structure formation of interstellar molecular clouds in astrophysical plasma. (paper)

  11. Low frequency electrostatic modes in a magnetized dusty plasma

    International Nuclear Information System (INIS)

    Salimullah, M.; Hassan, M.H.A.

    1991-09-01

    The dispersion properties of low frequency electrostatic modes in a dusty plasma in the presence of a static homogeneous magnetic field are examined. It is found that the presence of the dust particles and the static magnetic field have significant effects on the dispersion relations. For the parallel propagation the electrostatic mode is slightly modified by the magnetic field for the ion acoustic branch. A new longitudinal mode arises at the extreme low frequency limit, which is unaffected by the magnetic field for the parallel propagation. For the transverse propagation the ion acoustic mode is not affected by the magnetic field. However, the undamped extreme low frequency mode is significantly modified by the presence of the magnetic field for the propagation transverse to the direction of the magnetic field. (author). 23 refs

  12. Dusty plasma processes in Earth's polar summer mesosphere

    Science.gov (United States)

    Popel, S. I.; Dubinsky, A. Yu.; Dubinsky

    2013-08-01

    A self-consistent model for the description of dusty plasma structures, such as noctilucent clouds (NLC) and polar mesosphere summer echoes (PMSE), which are frequently grouped together under the common term polar mesospheric clouds, is presented. The model takes into account the processes of condensation of water vapor, ionization, recombination, action of solar radiation, sedimentation, dust particle growth, dust particle charging, electric fields, etc. Using the model, we explain the basic data of observations on the behavior of charged component in polar summer mesosphere. Furthermore, we show the influence of initial distributions of fine particles as well as that of the processes of condensation and water molecule absorption by fine particles on the formation of NLC and PMSE. We also illustrate the possibility of the formation of layered structure and sharp boundaries of NLC.

  13. Effect of polarization force on the Jeans instability in collisional dusty plasmas

    Science.gov (United States)

    A, ABBASI; M, R. RASHIDIAN VAZIRI

    2018-03-01

    The Jeans instability in collisional dusty plasmas has been analytically investigated by considering the polarization force effect. Instabilities due to dust-neutral and ion-neutral drags can occur in electrostatic waves of collisional dusty plasmas with self-gravitating particles. In this study, the effect of gravitational force on heavy dust particles is considered in tandem with both the polarization and electrostatic forces. The theoretical framework has been developed and the dispersion relation and instability growth rate have been derived, assuming the plane wave approximation. The derived instability growth rate shows that, in collisional dusty plasmas, the Jeans instability strongly depends on the magnitude of the polarization force.

  14. Dusty Plasma Physics Facility for the International Space Station

    Science.gov (United States)

    Goree, John; Hahn, Inseob

    2015-09-01

    The Dusty Plasma Physics Facility (DPPF) is an instrument planned for the International Space Station (ISS). If approved by NASA, JPL will build and operate the facility, and NASA will issue calls for proposals allowing investigators outside JPL to carry out research, public education, and outreach. Microgravity conditions on the ISS will be useful for eliminating two unwanted effects of gravity: sedimentation of dust particles to the bottom of a plasma chamber, and masking weak forces such as the ion drag force that act on dust particles. The DPPF facility is expected to support multiple scientific users. It will have a modular design, with a scientific locker, or insert, that can be exchanged without removing the entire facility. The first insert will use a parallel-plate radio-frequency discharge, polymer microspheres, and high-speed video cameras. This first insert will be designed for fundamental physics experiments. Possible future inserts could be designed for other purposes, such as engineering applications, and experimental simulations of astrophysical or geophysical conditions. The design of the facility will allow remote operation from ground-based laboratories, using telescience.

  15. THERMODYNAMIC REASONS OF AGGLOMERATION OF DUST PARTICLES IN THE THERMAL DUSTY PLASMA

    Directory of Open Access Journals (Sweden)

    V.I.Vishnyakov

    2003-01-01

    Full Text Available The thermodynamic equilibrium of thermal dusty plasmas consisting of ionized gas (plasma and solid particles (dust grains, which interact with each other, is studied. The tendency of grains in dusty plasmas to agglomerate corresponds to the tendency of dusty plasmas to balanced states. When grains agglomerate, electrical perturbations generated by each grain concentrate inside the agglomerate. The plasma is perturbed only by the agglomerate's exterior surface. The greater number of possible states for electrons and ions in plasma depends on the volume of perturbation of grains. The fewer are the perturbations the greater is the amount of possible states for electrons and ions in plasma. If the grains collected from a distance smaller than 8 Debye lengths, the total volume of perturbations is minimized; the free energy of the plasma is also minimized.

  16. Ideal gas behavior of a strongly-coupled complex (dusty) plasma

    OpenAIRE

    Oxtoby, Neil P.; Griffith, Elias J.; Durniak, Céline; Ralph, Jason F.; Samsonov, Dmitry

    2012-01-01

    In a laboratory, a two-dimensional complex (dusty) plasma consists of a low-density ionized gas containing a confined suspension of Yukawa-coupled plastic microspheres. For an initial crystal-like form, we report ideal gas behavior in this strongly coupled system during shock-wave experiments. This evidence supports the use of the ideal gas law as the equation of state for soft crystals such as those formed by dusty plasmas.

  17. Effect of random charge fluctuation on strongly coupled dusty Plasma

    Science.gov (United States)

    Issaad, M.; Rouiguia, L.; Djebli, M.

    2008-09-01

    Modeling the interaction between particles is an open issue in dusty plasma. We dealt with strongly coupled dust particles in two dimensional confined system. For small number of clusters, we investigate the effect of random charge fluctuation on background configuration. The study is conducted for a short rang as well as a long rang potential interaction. Numerical simulation is performed using Monte-Carlo simulation in the presence of parabolic confinement and at low temperature. We have studied the background configurations for a dust particles with constant charge and in the presence of random charge fluctuation due to the discrete nature of charge carriers. The latter is studied for a positively charged dust when the dominant charging process is due to photo-emission from the dust surface. It is found, for small classical cluster consisting of small number of particles, short rang potential gives the same result as long rang one. It is also found that the random charge fluctuation affect the background configurations.

  18. Dusty plasmas in the lunar exosphere: Effects of meteoroids

    Science.gov (United States)

    Popel, S. I.; Golub', A. P.; Zelenyi, L. M.; Horányi, M.

    2018-01-01

    A possibility of the formation in the lunar exosphere of dust cloud due to meteoroid impacts onto the lunar surface is studied. The main attention is paid to the high altitudes over the lunar surface including the range of the altitudes between 30 and 110 km where the measurements of dust were performed within the NASA LADEE mission. From the viewpoint of the formation of dust cloud at high altitudes over the Moon, the most important zone formed by the meteoroid impact is the zone of melting of substance. Only the droplets originated from this zone have the speeds between the first and second astronautical velocities (for the Moon). Correspondingly, only such droplets can perform finite movement around the Moon. The liquid droplets harden when rising over the lunar surface. Furthermore, they aquire electric charges due to the action, in particular, of the solar wind electrons and ions, as well as of the solar radiation. Thus dusty plasmas exist in the lunar exosphere with the characteristic number density ≲ 10-2 m-3 of dust particles with the sizes from 300 nm to 1 μm which is in accordance with the results of measurements performed by LADEE.

  19. Equation of state for two-dimensional dusty plasma liquids and its applications

    Science.gov (United States)

    Feng, Yan

    2017-10-01

    Laboratory dusty plasma consists of free electrons, free ions, and micro-sized dust particles with thousands of negative elementary charges. Due to their extremely low charge-to-mass ratio, these dust particles are strongly coupled, arranging themselves like atoms in liquids or solids. Due to the shielding effects of electrons and ions, dust particles interact with each other through the Yukawa potential, so that simulations of Yukawa liquids or solids are used to study properties of dusty plasmas. In the past two decades, the properties of liquid 2D dusty plasmas have been widely studied from experiments to theories and simulations. However, from our literature search, we have not found a quantitative and comprehensive study of properties of 2D liquid dusty plasmas over a wide range of plasma conditions. Here, from molecular-dynamics simulations of Yukawa liquids, we have obtained a concise equation of state (EOS) for the 2D liquid dusty plasmas from empirical fitting, which contains three quantities of the internal pressure, the coupling parameter, and the screening parameter. From this EOS, different thermodynamical processes can be directly derived, such as isotherms, isobars and isochores. Also, various physical properties of 2D liquid dusty plasmas, like the bulk modulus of elasticity, can be analytically derived, so that the sound speeds can be obtained. Finally, an analytical expression of the specific heat for 2D liquid dusty plasmas has been achieved. Work supported by the National Natural Science Foundation of China under Grant No. 11505124, the 1000 Youth Talents Plan, and the startup funds from Soochow University.

  20. Dust-acoustic waves and stability in the permeating dusty plasma. II. Power-law distributions

    International Nuclear Information System (INIS)

    Gong Jingyu; Du Jiulin; Liu Zhipeng

    2012-01-01

    The dust-acoustic waves and the stability theory for the permeating dusty plasma with power-law distributions are studied by using nonextensive q-statistics. In two limiting physical cases, when the thermal velocity of the flowing dusty plasma is much larger than, and much smaller than the phase velocity of the waves, we derived the dust-acoustic wave frequency, the instability growth rate, and the instability critical flowing velocity. As compared with the formulae obtained in part I [Gong et al., Phys. Plasmas 19, 043704 (2012)], all formulae of the present cases and the resulting plasma characteristics are q-dependent, and the power-law distribution of each plasma component of the permeating dusty plasma has a different q-parameter and thus has a different nonextensive effect. Further, we make numerical analyses of an example that a cometary plasma tail is passing through the interplanetary space dusty plasma and we show that these power-law distributions have significant effects on the plasma characteristics of this kind of plasma environment.

  1. Application of stereoscopic particle image velocimetry to studies of transport in a dusty (complex) plasma

    International Nuclear Information System (INIS)

    Thomas, Edward Jr.; Williams, Jeremiah D.; Silver, Jennifer

    2004-01-01

    Over the past 5 years, two-dimensional particle image velocimetry (PIV) techniques [E. Thomas, Jr., Phys. Plasmas 6, 2672 (1999)] have been used to obtain detailed measurements of microparticle transport in dusty plasmas. This Letter reports on an extension of these techniques to a three-dimensional velocity vector measurement approach using stereoscopic PIV. Initial measurements using the stereoscopic PIV diagnostic are presented

  2. Collisional effect on lower hybrid waves instability in a dusty plasma ...

    African Journals Online (AJOL)

    The effect of particle collisions on lower hybrid modes in a dusty plasma is studied. The dispersion relation derived from fluid theory is numerically solved for plasma parameters relevant to determine the modification in wave propagation due to collisions. This study is relevant to the earth's lower atmosphere, in particular, the ...

  3. Viscosity of two-dimensional strongly coupled dusty plasma modified by a perpendicular magnetic field.

    Science.gov (United States)

    Feng, Yan; Lin, Wei; Murillo, M S

    2017-11-01

    Transport properties of two-dimensional (2D) strongly coupled dusty plasmas have been investigated in detail, but never for viscosity with a strong perpendicular magnetic field; here, we examine this scenario using Langevin dynamics simulations of 2D liquids with a binary Yukawa interparticle interaction. The shear viscosity η of 2D liquid dusty plasma is estimated from the simulation data using the Green-Kubo relation, which is the integration of the shear stress autocorrelation function. It is found that, when a perpendicular magnetic field is applied, the shear viscosity of 2D liquid dusty plasma is modified substantially. When the magnetic field is increased, its viscosity increases at low temperatures, while at high temperatures its viscosity diminishes. It is determined that these different variational trends of η arise from the different behaviors of the kinetic and potential parts of the shear stress under external magnetic fields.

  4. Decay instability of an upper hybrid wave in a magnetized dusty plasmas

    International Nuclear Information System (INIS)

    Gahlot, Ajay; Walia, Ritu; Sharma, Jyotsna; Sharma, Suresh C.; Sharma, Rinku

    2013-01-01

    The decay instability of an upper hybrid wave into an upper hybrid sideband wave and low frequency ion-cyclotron wave are studied in a magnetized dusty plasma cylinder. The growth rate and ion-cyclotron mode frequencies were evaluated based on existing dusty plasma parameters. It is found that the unstable mode frequency increases linearly with δ (ion-to-electron density ratio). In addition, the growth rate of the unstable ion-cyclotron mode decreases sharply for lower values of δ in the presence of dust charge fluctuations, i.e., the dust grains increases the damping effect in three wave interaction process.

  5. Viscosity calculated in simulations of strongly coupled dusty plasmas with gas friction

    International Nuclear Information System (INIS)

    Feng Yan; Goree, J.; Liu Bin

    2011-01-01

    A two-dimensional strongly coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity η and the wave-number-dependent viscosity η(k) are calculated from the microscopic shear in the random motion of particles. A recently developed method of calculating the wave-number-dependent viscosity η(k) is validated by comparing the results of η(k) from the two simulations. It is also verified that the Green-Kubo relation can still yield an accurate measure of the static viscosity η in the presence of a modest level of friction as in dusty plasma experiments.

  6. Dynamical aspects of various solitary waves and double layers in dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Das, G.C. [Plasma Physics Division, Institute of Advanced Study in Science Technology, Khanapara, Guwahati-781022, Assam (India); Sarma, J. [Department of Mathematics, R. G. Baruah College, Guwahati-781025, Assam (India); Talukdar, M. [Computer Science Division, Institute of Advanced Study in Science Technology, Khanapara, Guwahati-781022, Assam (India)

    1998-01-01

    Employing quasipotential analysis, the Sagdeev potential equation has been derived in a multicomponent plasma consisting of free and trapped electrons and contaminated by the dust charged grains forming therein by the attachment of electrons to finite-size dust particles. Because of the free and trapped electrons in the dusty plasma, the plasma-acoustic wave exhibits the different features of various solitary waves. The Sagdeev potential equation, at a small-amplitude approximation, leads to the evaluation, by a proposed new formalism of a simple wave solution technique, of the new scenario of solitary wave propagation in a dusty plasma. It has been shown that the ordering of the nonisothermality in the dusty plasma also plays a unique role. In the case of a plasma with first-order nonisothermality, the Sagdeev potential equation derives the compressive solitary wave propagation, while for plasma with higher-order nonisothermality the method might fail to solve the Sagdeev potential equation and, thus, an alternate method is used to reveal the coexistence of compressive and rarefactive solitary waves. In addition, for certain plasma parameters, the solitary waves disappear and a double layer is expected. Again, with the better approximation in the Sagdeev potential, more features of solitary waves, known as spiky and explosive, along with the double layers, are also highlighted. The observations made of the solitary waves could be of further interest in the understanding of laboratory and space plasmas.{copyright} {ital 1998 American Institute of Physics.}

  7. Large-amplitude double layers in a dusty plasma with an arbitrary ...

    Indian Academy of Sciences (India)

    Abstract. Formation of large-amplitude double layers in a dusty plasma whose con- stituents are electrons, ions, warm dust grains and positive ion beam are studied using. Sagdeev's pseudopotential technique. Existence of double layers is investigated. It is found that both the temperature of dust particles and ion beam ...

  8. Dust-acoustic solitary waves in a dusty plasma with two-temperature ...

    Indian Academy of Sciences (India)

    acoustic waves in a dusty plasma (containing a negatively charged dust fluid, Boltzmann distributed electrons and two-temperature nonthermal ions) is investigated. The effects of two-temperature nonthermal ions on the basic properties of small but ...

  9. Large-amplitude double layers in a dusty plasma with an arbitrary ...

    Indian Academy of Sciences (India)

    Formation of large-amplitude double layers in a dusty plasma whose constituents are electrons, ions, warm dust grains and positive ion beam are studied using Sagdeev's pseudopotential technique. Existence of double layers is investigated. It is found that both the temperature of dust particles and ion beam temperature ...

  10. Dust-ion-acoustic Gardner double layers in a dusty plasma with two ...

    Indian Academy of Sciences (India)

    Abstract. The properties of dust-ion-acoustic Gardner double layers (DIA GDLs) in an unmag- netized dusty plasma, whose constituents are negatively-charged stationary dust, inertial ions, and. Boltzmann electrons of two distinct temperatures, are rigorously investigated by employing the reductive perturbation method: ...

  11. Dust-acoustic solitary waves in a dusty plasma with two-temperature ...

    Indian Academy of Sciences (India)

    Abstract. By using reductive perturbation method, the nonlinear propagation of dust-acoustic waves in a dusty plasma (containing a negatively charged dust fluid, Boltzmann distributed electrons and two-temperature nonthermal ions) is investigated. The effects of two-temperature nonthermal ions on the basic properties of ...

  12. (KP) equation in warm dusty plasma with variable dust charge, two ...

    Indian Academy of Sciences (India)

    In this work, the propagation of nonlinear waves in warm dusty plasmas with variable dust charge, two-temperature ion and nonthermal electron is studied. By using the reductive perturbation theory, the Kadomstev–Petviashvili (KP) equation is derived. The energy of the soliton and the linear dispersion relation are obtained ...

  13. Application of tomographic particle image velocimetry to studies of transport in complex (dusty) plasma

    International Nuclear Information System (INIS)

    Williams, Jeremiah D.

    2011-01-01

    Over the past twelve years, two-dimensional and stereoscopic particle image velocimetry (PIV) techniques have been used to obtain detailed measurements of the thermal and transport properties of the microparticle component of dusty plasma systems. This letter reports on an extension of these techniques to obtain a volumetric, three-dimensional velocity vector measurement using tomographic PIV. Initial measurements using the tomographic PIV diagnostic are presented.

  14. Propagation of ion-acoustic waves in a warm dusty plasma with electron inertia

    Science.gov (United States)

    Barman, S. N.; Talukdar, A.

    2011-08-01

    The KdV equation is derived for weakly nonlinear ion-acoustic waves in an unmagnetized warm dusty plasma with electron inertia. It has been shown that the inclusion of electron inertia and pressure variation of the species not only significantly modifies the basic features (width and amplitude) of dust ion-acoustic solitions, but also introduces a new parametric regime for the existence of positive and negative solitons.

  15. Acoustic Wave in a Dusty Plasma with Frequent Grain Charging Collisions

    International Nuclear Information System (INIS)

    Lee, Hee J.; Cho, Sang-Hoon

    2003-01-01

    The sink terms in the electron and ion continuity equations and the frictional terms in the momentum equations of a dusty plasma are obtained by taking moments of a kinetic equation which takes into account the grain charging collisions by electrons and ions. We show that an acoustic wave can propagate as a normal mode in the parameter regime where the frequencies of charging collisions are much greater than the wave frequency

  16. Computing the complex : Dusty plasmas in the presence of magnetic fields and UV radiation

    Science.gov (United States)

    Land, V.

    2007-12-01

    About 90% of the visible universe is plasma. Interstellar clouds, stellar cores and atmospheres, the Solar wind, the Earth's ionosphere, polar lights, and lightning are all plasma; ionized gases, consisting of electrons, ions, and neutrals. Not only many industries, like the microchip and solar cell industry, but also future fusion power stations, rely heavily on the use of plasma. More and more, home appliances include plasma technologies, like compact fluorescent light sources, and plasma screens. Dust particles, which can disrupt plasma processes, enter these plasmas, through chemical reactions in the plasma, or through interactions between plasma and walls. For instance, during microchip fabrication, dust particles can destroy the tiny, nanometre-sized structures on the surface of these chips. On the other hand, dust particles orbiting Young Stellar Objects coagulate and form the seeds of planets. In order to understand fundamental processes, such as planet formation, or to optimize industrial plasma processes, a thorough description of dusty plasma is necessary. Dust particles immersed in plasma collect ions and electrons from the plasma and charge up electrically. Therefore, the presence of dust changes plasma, while at the same time many forces start acting on the dust. Therefore, the dust and plasma become coupled, making dusty plasma a very complex medium to describe, in which many length and time scales play a role, from the Debye length to the length of the electrodes, and from the inverse plasma frequencies to the dust transport times. Using a self-consistent fluid model, we simulate these multi-scale dusty plasmas in radio frequency discharges under micro-gravity. We show that moderate non-linear scattering of ions by the dust particles is the most important aspect in the calculation of the ion drag force. This force is also responsible for the formation of a dust-free 'void' in dusty plasma under micro-gravity, caused by ions moving from the centre of

  17. Streaming instability in a velocity–sheared dusty plasma | Duwa ...

    African Journals Online (AJOL)

    A two-stream instability, obtained from kinetic theory, of strongly velocity-sheared inhomogeneous streaming electron in a magnetized plasma in the presence of negatively charged dust is discussed. Various cold plasma approximations were considered and it is shown that when the diamagnetic effect of ion can be ignored ...

  18. Interaction of nanosecond ultraviolet laser pulses with reactive dusty plasma

    Science.gov (United States)

    van de Wetering, F. M. J. H.; Oosterbeek, W.; Beckers, J.; Nijdam, S.; Gibert, T.; Mikikian, M.; Rabat, H.; Kovačević, E.; Berndt, J.

    2016-05-01

    Even though UV laser pulses that irradiate a gas discharge are small compared to the plasma volume (≲3%) and plasma-on time (≲6 × 10-6%), they are found to dramatically change the discharge characteristics on a global scale. The reactive argon-acetylene plasma allows the growth of nanoparticles with diameters up to 1 μm, which are formed inside the discharge volume due to spontaneous polymerization reactions. It is found that the laser pulses predominantly accelerate and enhance the coagulation phase and are able to suppress the formation of a dust void.

  19. Whispering Gallery Mode Spectroscopy as a Diagnostic for Dusty Plasmas

    International Nuclear Information System (INIS)

    Thieme, G.; Basner, R.; Ehlbeck, J.; Roepcke, J.; Maurer, H.; Kersten, H.; Davies, P. B.

    2008-01-01

    Whispering-gallery-mode spectroscopy is being assessed as a diagnostic method for the characterisation of size and chemical composition of spherical particles levitated in a plasma. With a pulsed laser whispering gallery modes (cavity resonances) are excited in individual microspheres leading to enhanced Raman scattering or fluorescence at characteristic wavelengths. This method can be used to gain specific information from the particle surface and is thus of great interest for the characterisation of layers deposited on microparticles, e.g. in molecular plasmas. We present investigations of different microparticles in air and results from fluorescent particles levitated in an Argon rf plasma.

  20. Interaction of nanosecond ultraviolet laser pulses with reactive dusty plasma

    International Nuclear Information System (INIS)

    Wetering, F. M. J. H. van de; Oosterbeek, W.; Beckers, J.; Nijdam, S.; Gibert, T.; Mikikian, M.; Rabat, H.; Kovačević, E.; Berndt, J.

    2016-01-01

    Even though UV laser pulses that irradiate a gas discharge are small compared to the plasma volume (≲3%) and plasma-on time (≲6 × 10 −6 %), they are found to dramatically change the discharge characteristics on a global scale. The reactive argon–acetylene plasma allows the growth of nanoparticles with diameters up to 1 μm, which are formed inside the discharge volume due to spontaneous polymerization reactions. It is found that the laser pulses predominantly accelerate and enhance the coagulation phase and are able to suppress the formation of a dust void.

  1. Standing surface waves in dusty microwave slot-excited plasma

    International Nuclear Information System (INIS)

    Ostrikov, K.N.; Yu, M.Y.; Sugai, H.

    2000-01-01

    Full text: The effect of charged dust particles on microwave slot-excited plasma has been studied. The dusts absorb significant proportion of the plasma electrons, which leads to a substantial modification of the electromagnetic field structure. The overall charge balance and the eigenfrequencies of the standing TM electromagnetic surface modes are modified by the presence of dust. It has been found that the originally excited surface waves can be shifted out of resonance. For certain proportions of dusts, mode conversion appears to be possible. Microwave gas discharges sustained by surface waves (SW) are promising for many industrial applications as sources of large-volume and large-area low-temperature plasmas. Here, we study the surface-wave sustained microwave plasma reactor contaminated by fine dust particles that usually appear as a substrate-etching product or as a result of polymerization in the gaseous phase. The structure that models the slot-excited planar plasma source is considered. A vertical circular cylinder is short-circuited at its top by a metal plate. A dielectric layer isolates the cylinder top from the plasma, and the chamber bottom is open. We have shown that uncontrolled release of the dusts in the discharge chamber can adversely affect the discharge performance and under certain conditions cause a discharge disruption. This can best be understood by noting that macroparticles absorb a significant proportion of plasma electrons and hence modify the ionization-recombination balance. Moreover, stable operation of the microwave surface-wave sustained discharge depends on the resonant conditions for the operating mode, and it is thus crucial to understand how dusts affect the eigenfrequencies of the SWs. We have demonstrated that introduction of additional amounts of contaminant results in a significant shift of the electron plasma density from its resonant value for the initially excited resonant mode. The system can thus be moved out of

  2. Probing a dusty magnetized plasma with self-excited dust-density waves

    Science.gov (United States)

    Tadsen, Benjamin; Greiner, Franko; Piel, Alexander

    2018-03-01

    A cloud of nanodust particles is created in a reactive argon-acetylene plasma. It is then transformed into a dusty magnetized argon plasma. Plasma parameters are obtained with the dust-density wave diagnostic introduced by Tadsen et al. [Phys. Plasmas 22, 113701 (2015), 10.1063/1.4934927]. A change from an open to a cylindrically enclosed nanodust cloud, which was observed earlier, can now be explained by a stronger electric confinement if a vertical magnetic field is present. Using two-dimensional extinction measurements and the inverse Abel transform to determine the dust density, a redistribution of the dust with increasing magnetic induction is found. The dust-density profile changes from being peaked around the central void to being peaked at an outer torus ring resulting in a hollow profile. As the plasma parameters cannot explain this behavior, we propose a rotation of the nanodust cloud in the magnetized plasma as the origin of the modified profile.

  3. Magnetosonic cnoidal waves and solitons in a magnetized dusty plasma

    Science.gov (United States)

    Kaur, Nimardeep; Singh, Manpreet; Saini, N. S.

    2018-04-01

    An investigation of magnetosonic nonlinear periodic (cnoidal) waves is presented in a magnetized electron-ion-dust ( e -i -d ) plasma having cold dust fluid with inertialess warm ions and electrons. The reductive perturbation method is employed to derive the Korteweg-de Vries equation. The dispersion relation for magnetosonic cnoidal waves is determined in the linear limit. The magnetosonic cnoidal wave solution is derived using the Sagdeev pseudopotential approach under the specific boundary conditions. There is the formation of only positive potential magnetosonic cnoidal waves and solitary structures in the high plasma-β limit. The effects of various plasma parameters, viz., plasma beta (β), σ (temperature ratio of electrons to ions), and μd (ratio of the number density of dust to electrons) on the characteristics of magnetosonic cnoidal waves are also studied numerically. The findings of the present investigation may be helpful in describing the characteristics of various nonlinear excitations in Earth's magnetosphere, solar wind, Saturn's magnetosphere, and space/astrophysical environments, where many space observations by various satellites confirm the existence of dust grains, highly energetic electrons, and high plasma-β.

  4. Laboratory measurements of dusty surface charging in plasma.

    Science.gov (United States)

    Chou, Kevin; Wang, Joseph

    2017-09-01

    A novel method is developed to study the charging of a conducting surface covered by a thin dust layer in plasma. The potential profile in the dust layer and the floating potential of the surface underneath are measured directly by embedding conducting wires in the dust and connecting the wires to a measurement plate outside the vacuum chamber, where a Trek non-contacting electrostatic voltmeter measures the floating potential of the measurement plate. Laboratory experiments are carried out to study plasma charging of a conducting plate covered by lunar dust simulant, JSC-1A. The results show that the plate potential is dependent on both the ambient plasma condition and the dust layer thickness. The current balance condition controls the floating potential of the dust surface while the dust layer acts as a capacitor and controls the potential of the plate with respect to the dust surface. Hence, a dust covered conducting plate will be charged more negatively than a clean plate.

  5. Charge neutrality of fine particle (dusty) plasmas and fine particle cloud under gravity

    Energy Technology Data Exchange (ETDEWEB)

    Totsuji, Hiroo, E-mail: totsuji-09@t.okadai.jp

    2017-03-11

    The enhancement of the charge neutrality due to the existence of fine particles is shown to occur generally under microgravity and in one-dimensional structures under gravity. As an application of the latter, the size and position of fine particle clouds relative to surrounding plasmas are determined under gravity. - Highlights: • In fine particle (dusty) plasmas, the charge neutrality is much enhanced by the existence of fine particles. • The enhancement of charge neutrality generally occurs under microgravity and gravity. • Structure of fine particle clouds under gravity is determined by applying the enhanced charge neutrality.

  6. Electron energy probability function in the temporal afterglow of a dusty plasma

    Science.gov (United States)

    Denysenko, I. B.; Azarenkov, N. A.; Ostrikov, K.; Yu, M. Y.

    2018-01-01

    The kinetic description of the electron energy probability function (EEPF) in a dusty afterglow plasma is considered for two typical cases: when the rate of electron-neutral momentum-transfer collisions is independent of the electron energy and when it is a power function of the electron energy. The electron Boltzmann equation is solved using the method of characteristics and analytical expressions for the EEPF are obtained for different initial EEPFs (including both Maxwellian and Druyvesteyn distributions) at electron energies larger than the dust-surface potential. The analytical EEPF functions are then used to analyze several experimental parameter regimes of the dust radius and density, the dust-charge decay time, the afterglow duration, etc. It is also found that absorption of electrons by the dust particles plays an important role in determining the EEPF in a dusty afterglow.

  7. The Bohm criterion for a dusty plasma sheath

    Indian Academy of Sciences (India)

    undergo temperature fluctuations due to collision, the mean square fluctuation in their temperature is much less than the equilibrium temperature. The problem of sheath dynamics with the plasma–wall interactions is of great importance in a number of areas, viz., plasma ion implantation, high-density com- puter chip ...

  8. Jeans instability of an inhomogeneous streaming dusty plasma

    Indian Academy of Sciences (India)

    associated emission nebula, escapes without being absorbed by the in-falling matter from the accretion disk, dust grain may pick up, depending on the thermal velocities of the background plasma particles, between 10 to 100 electronic charges [1]. These charged grains are not monochromatic in size. The size distribution ...

  9. Periodic long-range transport in a large volume dc glow discharge dusty plasma

    International Nuclear Information System (INIS)

    Thomas, Edward Jr.; Amatucci, William E.; Compton, Christopher; Christy, Brian; Jackson, Jon David

    2003-01-01

    In an earlier paper, the authors reported on observations of a variety of particle transport phenomena observed in DUPLEX--the DUsty PLasma EXperiment at the Naval Research Laboratory [E. Thomas, Jr., W. E. Amatucci, C. Compton, and B. Christy, Phys. Plasmas 9, 3154 (2002)]. DUPLEX is a large, transparent polycarbonate cylinder that is 40 cm in radius and 80 cm in height. dc glow discharge argon plasmas are generated in DUPLEX. In this paper, the authors expand upon one particular feature of particle transport in DUPLEX, the long-range (i.e., greater than 15 cm), periodic (T∼2.5 min) transport of suspended alumina particles through the plasma. A detailed description of this particle motion through the plasma is presented. Finally, a qualitative model describing the phenomena that lead to this transport is also given

  10. Design of new dusty plasma apparatus to view 3D particle dynamics of fluorescent dust clouds

    Science.gov (United States)

    Thome, Kathreen; Fontanetta, Alexandra; Zwicker, Andrew

    2008-11-01

    Particles suspended in dusty plasmas represent both contamination in industrial plasmas and a primary interstellar medium component. Typically, dusty plasma behavior is studied by laser scattering techniques that provide 2D dust cloud images. However, the 3D structure of the dust cloud is essential to understand the waves, group dynamics, and stabilities of the cloud. Techniques used to study this structure include stereoscopic particle image velocimetry and rapid laser scanning. Our UV illumination technique reveals translational and rotational velocities of fluorescent dust particles as a function of UV intensity. The new argon DC glow discharge experiment designed to study the 3D aspects of fluorescent dust consists of a 13.25'' diameter chamber, two 8'' window ports for CCD cameras, one along the plasma and another transverse to it, two additional 8'' window ports transverse to the plasma for laser or UV light illumination of the dust cloud, and a diagnostic probe port. Results from different electrodes--including mesh and ring--observations and imaging will be presented.

  11. Dust Acoustic Solitons in the Dusty Plasma of the Earth's Ionosphere

    International Nuclear Information System (INIS)

    Kopnin, S.I.; Kosarev, I.N.; Popel, S.I.; Yu, M.Y.

    2005-01-01

    Stratified structures that are observed at heights of 80-95 km in the lower part of the Earth's ionosphere are known as noctilucent clouds and polar mesosphere summer echoes. These structures are thought to be associated with the presence of vast amounts of charged dust or aerosols. The layers in the lower ionosphere where there are substantial amounts of dust are called the dusty ionosphere. The dust grains can carry a positive or a negative charge, depending on their constituent materials. As a rule, the grains are ice crystals, which may contain metallic inclusions. A grain with a sufficiently large metallic content can acquire a positive charge. Crystals of pure ice are charged negatively. The distribution of the dust grains over their charges has a profound impact on the ionizational and other properties of dust structures in the dusty ionosphere. In the present paper, a study is made of the effect of the sign of the dust charge on the properties of dust acoustic solitons propagating in the dusty ionosphere. It is shown that, when the dust charge is positive, dust acoustic solitons correspond to a hill in the electron density and a well in the ion density. When the dust is charged negatively, the situation is opposite. These differences in the properties of dust acoustic solitons can be used to diagnose the plasmas of noctilucent clouds and polar mesosphere summer echoes

  12. Electrical conductivity of the thermal dusty plasma under the conditions of a hybrid plasma environment simulation facility

    Science.gov (United States)

    Zhukhovitskii, Dmitry I.; Petrov, Oleg F.; Hyde, Truell W.; Herdrich, Georg; Laufer, Rene; Dropmann, Michael; Matthews, Lorin S.

    2015-05-01

    We discuss the inductively heated plasma generator (IPG) facility in application to the generation of the thermal dusty plasma formed by the positively charged dust particles and the electrons emitted by them. We develop a theoretical model for the calculation of plasma electrical conductivity under typical conditions of the IPG. We show that the electrical conductivity of dusty plasma is defined by collisions with the neutral gas molecules and by the electron number density. The latter is calculated in the approximations of an ideal and strongly coupled particle system and in the regime of weak and strong screening of the particle charge. The maximum attainable electron number density and corresponding maximum plasma electrical conductivity prove to be independent of the particle emissivity. Analysis of available experiments is performed, in particular, of our recent experiment with plasma formed by the combustion products of a propane-air mixture and the CeO2 particles injected into it. A good correlation between the theory and experimental data points to the adequacy of our approach. Our main conclusion is that a level of the electrical conductivity due to the thermal ionization of the dust particles is sufficiently high to compete with that of the potassium-doped plasmas.

  13. Shock-wave structure formation in a dusty plasma

    International Nuclear Information System (INIS)

    Popel', S.I.; Golub', A.P.; Loseva, T.V.; Bingkhem, R.; Benkadda, S.

    2001-01-01

    Nonstationary problem on evolution perturbation and its transformation into nonlinear wave structure is considered. The method developed permits finding solution to the system of nonlinear evolution equations describing dust particles with variable charge, Boltzmann electron and inertia ions. An accurate stationary solution as ion-sonic wave structures explained by anomalous dissipation due to electric discharge of dust particles was found. Evolution of two types of initial perturbations was studied, i.e.: soliton and immobile region with increased density of ions - a step. Soliton evolution in plasma with variable charge of dust particles results in the appearance on nonstationary shock-wave structure, whereas the step evolution gives rise to appearance of a shock wave similar to the stationary one along with rarefaction wave [ru

  14. A new mathematical approach for shock-wave solution in a dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Das, G.C.; Dwivedi, C.B. [Plasma Physics Division, Institute of Advanced Study in Science and Technology, Khanapara, Guwahati-781022, Assam (India); Talukdar, M. [Computer Science Division, Institute of Advanced Study in Science and Technology, Khanapara, Guwahati-781022, Assam (India); Sarma, J. [Department of Mathematics, R. G. Baruah College, Guwahati-781025, Assam (India)

    1997-12-01

    The problem of nonlinear Burger equation in a plasma contaminated with heavy dust grains has been revisited. As discussed earlier [C. B. Dwivedi and B. P. Pandey, Phys. Plasmas {bold 2}, 9 (1995)], the Burger equation originates due to dust charge fluctuation dynamics. A new alternate mathematical approach based on a simple traveling wave formalism has been applied to find out the solution of the derived Burger equation, and the method recovers the known shock-wave solution. This technique, although having its own limitation, predicts successfully the salient features of the weak shock-wave structure in a dusty plasma with dust charge fluctuation dynamics. It is emphasized that this approach of the traveling wave formalism is being applied for the first time to solve the nonlinear wave equation in plasmas. {copyright} {ital 1997 American Institute of Physics.}

  15. On the Anderson localization conjecture in Dusty Plasma

    Science.gov (United States)

    Liaw, Constanze; Busse, Kyle; Matthews, Lorin; Hyde, Truell

    2015-11-01

    In 1958, Anderson suggested that sufficiently large impurities in a semi-conductor could lead to spatial localization of electrons. This idea unfolded into the field of Anderson Localization, one of the most fascinating phenomena in solid-state physics as it plays a major role in the conductive properties of imperfectly ordered materials. The Anderson Localization Conjecture claims that random disorder of any strength causes localization of electrons in the medium. The problem has proven to be highly non-trivial. Over the years the community has argued whether spatial localization occurs in 2D for small impurities. From a mathematical standpoint, the conjecture is still considered an open question. In 2013, Liaw challenged the commonly held assumption that localization holds in 2D by introducing a new mathematically more rigorous method to test for extended states, and applying it to the discrete random Schrödinger operator. One of the advantages of the underlying method is its versatility. It can be applied to any ordered system such as colloids, crystals, and atomic lattices. In a cross-disciplinary effort we merge this method with a numerical code used to simulate 2D physics systems, in preparation for experimentally testing the theory against complex plasma crystals.

  16. Simulation study on the growth of grains in dusty plasmas

    International Nuclear Information System (INIS)

    Sato, Tetsuya; Watanabe, Kunihiko

    1997-01-01

    A new particle simulation code is developed for studying the dynamics of the grains which are exposed to charging by the background plasma particles. Effects of regular attachment of electrons and ions, effects of secondary electron emission, and coagulation of grains are included in this code. Simulation results show that grains randomly change their charges from negative to positive, or from positive to negative in a 'flip-flop' fashion as a result of competition between the electron attachment and secondary electron emission. It is found that the flip-flop effect becomes remarkable when the radius of grains is of the order of 10 nm, because the attachment of a single electron to a grain is less effective on the surface potential for larger grains, while the average probability of electron attachment is smaller for smaller grains. Grains with opposite charges attract each other to coagulate, so that grains of size of 10 nm are likely to grow in size. The flip-flop effect is found to be essential to the growth of grains. (author)

  17. The parametric resonance features for theory of energy transfer in dusty plasma

    Science.gov (United States)

    Semyonov, V. P.; Timofeev, A. V.

    2015-11-01

    One of the mechanisms of energy transfer between degrees of freedom of dusty plasma system can be described by equations similar to Mathieu equation with account of stochastic forces. Such equation is studied by analytical approach. The solutions for higher order of accuracy are obtained. The method for numerical solution and resonance zone detection is proposed. The solution for the extended Mathieu equation is obtained for wide range of parameter values. The results of numerical solution are compared with analytical solutions of different order and known analytical results for Mathieu equation.

  18. Landau damping effects on dust-acoustic solitary waves in a dusty negative-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Barman, Arnab; Misra, A. P., E-mail: apmisra@visva-bharati.ac.in, E-mail: apmisra@gmail.com [Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan 731 235, West Bengal (India)

    2014-07-15

    The nonlinear theory of dust-acoustic waves (DAWs) with Landau damping is studied in an unmagnetized dusty negative-ion plasma in the extreme conditions when the free electrons are absent. The cold massive charged dusts are described by fluid equations, whereas the two-species of ions (positive and negative) are described by the kinetic Vlasov equations. A Korteweg-de Vries (KdV) equation with Landau damping, governing the dynamics of weakly nonlinear and weakly dispersive DAWs, is derived following Ott and Sudan [Phys. Fluids 12, 2388 (1969)]. It is shown that for some typical laboratory and space plasmas, the Landau damping (and the nonlinear) effects are more pronounced than the finite Debye length (dispersive) effects for which the KdV soliton theory is not applicable to DAWs in dusty pair-ion plasmas. The properties of the linear phase velocity, solitary wave amplitudes (in presence and absence of the Landau damping) as well as the Landau damping rate are studied with the effects of the positive ion to dust density ratio (μ{sub pd}) as well as the ratios of positive to negative ion temperatures (σ) and masses (m)

  19. Excitation of an acoustic pulse by an impulsive shear flow in a dusty plasma

    Science.gov (United States)

    Liu, Bin; Goree, John; Dusty plasma Team

    2017-10-01

    A dusty plasma is a strongly-coupled plasma that contains micron-sized particles. These particles, also called dust particles, are highly charged by ambient plasma; they interact with each other, sustaining collective wave motion. Both longitudinal and transverse waves can in general be excited. Here we use an electrostatic three-dimensional (3D) simulation to reveal a wave excitation mechanism that is due to viscous heating. In the simulation, an impulsive force was applied to drive a shear flow motion with a sudden onset. After a delay, a longitudinal acoustic pulse wave was observed, propagating outwards from the edge of the flow. We found that the viscous heating due to shear motion can result in a brief localized rarefaction in the dust cloud, leading to the excitation of a longitudinal acoustic wave. The simulation parameters were motivated by the PK-4 instrument on the International Space Station (ISS). Work was supported by NASA.

  20. Large-amplitude dust acoustic shocklets in non-Maxwellian dusty plasmas

    Science.gov (United States)

    Ali, S.; Naeem, Ismat; Mirza, Arshad M.

    2017-10-01

    The formation and propagation of fully nonlinear dust-acoustic (DA) waves and shocks are studied in a non-Maxwellian thermal dusty plasma which is composed of Maxwellian electrons and nonthermal energetic ions with a neutralizing background of negatively charged dust grains. For this purpose, we have solved dust dynamical equations along with quasineutrality equation by using a diagonalization matrix technique. A set of two characteristic wave equations is obtained, which admits both analytical and numerical solutions. Taylor expansion in the small-amplitude limit ( Φ ≪ 1 ) leads to nonlinear effective phase and shock speeds accounting for nonthermal energetic ions. It is numerically shown that DA pulses can be developed into DA shocklets involving the negative electrostatic potential, dust fluid velocity, and dust number density. These structures are significantly influenced by the ion-nonthermality, dust thermal correction, and temporal variations. However, the amplitudes of solitary and shock waves are found smaller in case of Cairns-distributed ions as compared to Kappa-distributed ions due to smaller linear and nonlinear effective phase speeds that cause smaller nonlinearity effects. The present results should be useful for understanding the nonlinear characteristics of large-amplitude DA excitations and nonstationary shocklets in a laboratory non-Maxwellian dusty plasma, where nonthermal energetic ions are present in addition to Maxwellian electrons.

  1. Charging-delay effect on longitudinal dust acoustic shock wave in strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Gupta, M.R.

    2005-01-01

    Taking into account the charging-delay effect, the nonlinear propagation characteristics of longitudinal dust acoustic wave in strongly coupled collisional dusty plasma described by generalized hydrodynamic model have been investigated. In the 'hydrodynamic limit', a Korteweg-de Vries Burger (KdVB) equation with a damping term arising due to dust-neutral collision is derived in which the Burger term is proportional to the dissipation due to dust viscosity through dust-dust correlation and charging-delay-induced anomalous dissipation. On the other hand, in the 'kinetic limit', a KdVB equation with a damping term and a nonlocal nonlinear forcing term arising due to memory-dependent strong correlation effect of dust fluid is derived in which the Burger term depends only on the charging-delay-induced dissipation. Numerical solution of integrodifferential equations reveals that (i) dissipation due to dust viscosity and principally due to charging delay causes excitation of the longitudinal dust acoustic shock wave in strongly coupled dusty plasma and (ii) dust-neutral collision does not appear to play any direct role in shock formation. The condition for the generation of shock is also discussed briefly

  2. Dependence of average inter-particle distance upon the temperature of neutrals in dusty plasma crystals

    Science.gov (United States)

    Nikolaev, V. S.; Timofeev, A. V.

    2018-01-01

    It is often suggested that inter-particle distance in stable dusty plasma structures decreases with cooling as a square root of neutral gas temperature. Deviations from this dependence (up to the increase at cryogenic temperatures) found in the experimental results for the pressures range 0.1–8.0 mbar and for the currents range 0.1–1.0 mA are given. Inter-particle distance dependences on the charge of particles, parameter of the trap and the screening length in surrounding plasma are obtained for different conditions from molecular dynamics simulations. They are well approximated by power functions in the mentioned range of parameters. It is found that under certain assumptions thermophoretical force is responsible for inter-particle distance increase at cryogenic temperatures.

  3. Transmission characteristics of microwave in a glow-discharge dusty plasma

    Science.gov (United States)

    Jia, Jieshu; Yuan, Chengxun; Gao, Ruilin; Liu, Sha; Yue, Feng; Wang, Ying; Zhou, Zhong-Xiang; Wu, Jian; Li, Hui

    2016-07-01

    In this study, the propagation characteristics of electromagnetic wave in a glow discharge plasma with dust particles are experimentally investigated. A helium alternating current glow discharge plasmas have been successfully generated. Measurements of the plasma parameters using Langmuir probes, in the absence of dust particles, provide plasma densities (ne) of 1017 m-3 and electron temperatures (Te) ranging from 2 to 4 eV. Dusty plasmas are made by adding 30 nm radius aluminum oxide (Al2O3) particles into the helium plasma. The density of the dust particle (nd) in the device is about 1011-1012 m-3. The propagation characteristics of electromagnetic waves are determined by a vector network analyzer with 4-6 GHz antennas. An apparent attenuation by the dust is observed, and the measured attenuation data are approximately in accordance with the theoretical calculations. The effects of gas pressure and input power on the propagation are also investigated. Results show that the transmission attenuation increases with the gas pressure and input power, the charged dust particles play a significant role in the microwave attenuation.

  4. One-dimensional nonlinear self-organized structures in dusty plasmas

    International Nuclear Information System (INIS)

    Tsytovich, V.N.

    2000-01-01

    Dusty plasmas, which are open systems, can form stable one-dimensional self-organized structures. Absorption of plasma by dust particles results in the plasma flux from the plasma regions where the dust is absent. It is found that, in a one-dimensional dust layer, this flux is completely determined by the number of dust particles per unit area of the layer surface. This number determines all of the other parameters of the steady-state dust structure; in particular, it determines the spatial distributions of the dust density, dust charge, electron and ion densities, and ion drift velocity. In these structures, a force and electrostatic balance is established that ensures the necessary conditions for confining the dust and plasma particles in the structure. The equilibrium structures exist only for subthermal ion flow velocities. This criterion determines the maximum possible number of dust particles per unit area in the steady-state structure. The structures have a universal thickness, and the dust density changes sharply at the edge of the structure. The structures with a size either less than or larger than the ion mean free path with respect to ion-neutral collisions, quasi-neutral and charged structures, and soliton- and anti-soliton-like structures are investigated. Laboratory experiments and observations in extraterrestrial plasma formation are discussed in relation to dust structures

  5. Dispersive properties and attraction instability of low-frequency collective modes in dusty plasmas

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Rezendes, D.

    1998-01-01

    A dispersion relation for low-frequency collective modes in dusty plasmas is derived with allowance for attractive and repulsive forces arising between the dust grains due to dissipative fluxes of plasma particles onto the grain surfaces. It is shown that these fluxes give rise to dust attraction instabilities, which are similar to the gravitational instability. In the range of wave numbers corresponding to the stability domain, two types of dust sound waves arise, depending on whether the wavelengths of the collective modes are longer or shorter than the mean free path of the plasma particles (i.e., the distance they travel before they collide with dust grains). The dispersion relation derived is valid for any ratio between the wavelength of the perturbations and the mean free path and encompasses the entire range of intermediate wave numbers. The critical wave numbers that determine the threshold for the onset of attraction instability, which is similar to the Jeans instability, can, in particular, lie within this range. The thresholds for attraction instability and the instability growth rates are obtained numerically for a wide range of the plasma parameters (such as the ratio of the ion temperature to the electron temperature) that are of interest for present-day experiments with dust crystals, plasma etching, and space plasma studies. Computer simulation shows that, in the nonlinear stage, the attraction instability causes the dust cloud to collapse, which leads to the formation of dust plasma crystals. Our investigation makes it possible to trace the processes in the initial stage of dust crystallization. Results are obtained for hydrogen and silicon plasmas, which are most typical of laboratory experiments

  6. Linear and nonlinear dust acoustic waves in an inhomogeneous magnetized dusty plasma with nonextensive electrons

    Energy Technology Data Exchange (ETDEWEB)

    El-Taibany, W. F., E-mail: eltaibany@du.edu.eg, E-mail: eltaibany@hotmail.com; Selim, M. M.; Al-Abbasy, O. M. [Department of Physics, Faculty of Science, Damietta University, New Damietta P. O. 34517 (Egypt); El-Bedwehy, N. A., E-mail: nab-elbedwehy@yahoo.com [Department of Mathematics, Faculty of Science, Damietta University, New Damietta P. O. 34517 (Egypt)

    2014-07-15

    The propagation of both linear and nonlinear dust acoustic waves (DAWs) in an inhomogeneous magnetized collisional and warm dusty plasma (DP) consisting of Boltzmann ions, nonextensive electrons, and inertial dust particles is investigated. The number density gradients of all DP components besides the inhomogeneities of electrostatic potential and the initial dust fluid velocity are taken into account. The linear dispersion relation and a nonlinear modified Zakharov-Kusnetsov (MZK) equation governing the propagation of the three-dimensional DAWs are derived. The analytical solution of the MZK reveals the creation of both compressive and rarefactive DAW solitons in the proposed model. It is found that the inhomogeneity dimension parameter and the electron nonextensive parameter affect significantly the nonlinear DAW's amplitude, width, and Mach number. The relations of our findings with some astrophysical situations have been given.

  7. Cooperative microexcitations in 2+1D chain-bundle dusty plasma liquids

    International Nuclear Information System (INIS)

    Io, C.-W.; Chan, C.-L.; Lin I

    2010-01-01

    Through direct visualization at the discrete level, the microexcitations in cold 2+1D dusty plasma liquids formed by negatively charged dusts suspended in low pressure gaseous discharges were experimentally investigated, in which the downward ion flow wake field induces strong vertical coupling and chain bundle structure. It is found that the horizontal structure and motion are similar to those of the two-dimensional liquid. Different types of basic cooperative chain excitations: straight vertical chains with small amplitude jittering, chain tilting-restraightening, bundle twisting-restraightening, and chain breaking-reconnection, are observed. The region with good (poor) horizontal structural order prefers the straight (tilted or broken) chains with little (large) titling and tilting rate.

  8. Scattering and extinction of ion beams in a dusty plasma device

    International Nuclear Information System (INIS)

    Nakamura, Y.

    2001-01-01

    Collisions of ions with charged dust grains are important for the propagation of low frequency waves such as dust acoustic waves and dust ion-acoustic waves. The collision cross-sectional area of charged dust grains depends on the velocity of an ion beam. The collision cross-sectional area of charged dust grains with beam ions is measured. It is compared with the geometrical cross-sectional area of the grain. The experiment is performed in a dusty double-plasma device with glass beads of 8.9 μm in average diameter. The ion beam current and energy are measured with a directional retarding potential analyzer. It is observed that, when dust density inside the system is increased, the beam current ratio is reduced. From the reduction of the ion beam current, the effective cross-sectional area of the dust particle is estimated as a function of the beam energy

  9. Collisionless damping of dust-acoustic waves in a charge varying dusty plasma with nonextensive ions

    International Nuclear Information System (INIS)

    Amour, Rabia; Tribeche, Mouloud

    2014-01-01

    The charge variation induced nonlinear dust-acoustic wave damping in a charge varying dusty plasma with nonextensive ions is considered. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust acoustic wave propagation to be described by a damped Korteweg-de Vries (dK-dV) equation the coefficients of which depend sensitively on the nonextensive parameter q. The damping term, solely due to the dust charge variation, is affected by the ion nonextensivity. For the sake of completeness, the possible effects of nonextensivity and collisionless damping on weakly nonlinear wave packets described by the dK-dV equation are succinctly outlined by deriving a nonlinear Schrödinger-like equation with a complex nonlinear coefficient

  10. Collisionless damping of dust-acoustic waves in a charge varying dusty plasma with nonextensive ions

    Energy Technology Data Exchange (ETDEWEB)

    Amour, Rabia; Tribeche, Mouloud [Faculty of Physics, Theoretical Physics Laboratory (TPL), Plasma Physics Group (PPG), University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria)

    2014-12-15

    The charge variation induced nonlinear dust-acoustic wave damping in a charge varying dusty plasma with nonextensive ions is considered. It is shown that the collisionless damping due to dust charge fluctuation causes the nonlinear dust acoustic wave propagation to be described by a damped Korteweg-de Vries (dK-dV) equation the coefficients of which depend sensitively on the nonextensive parameter q. The damping term, solely due to the dust charge variation, is affected by the ion nonextensivity. For the sake of completeness, the possible effects of nonextensivity and collisionless damping on weakly nonlinear wave packets described by the dK-dV equation are succinctly outlined by deriving a nonlinear Schrödinger-like equation with a complex nonlinear coefficient.

  11. Observation of dust acoustic shock wave in a strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    Sharma, Sumita K.; Boruah, A.; Nakamura, Y.; Bailung, H.

    2016-01-01

    Dust acoustic shock wave is observed in a strongly coupled laboratory dusty plasma. A supersonic flow of charged microparticles is allowed to perturb a stationary dust fluid to excite dust acoustic shock wave. The evolution process beginning with steepening of initial wave front and then formation of a stable shock structure is similar to the numerical results of the Korteweg-de Vries-Burgers equation. The measured Mach number of the observed shock wave agrees with the theoretical results. Reduction of shock amplitude at large distances is also observed due to the dust neutral collision and viscosity effects. The dispersion relation and the spatial damping of a linear dust acoustic wave are also measured and compared with the relevant theory.

  12. Dust ion acoustic solitary waves in a magnetized dusty plasma with anisotropic ion pressure

    International Nuclear Information System (INIS)

    Choi, Cheong Rim; Ryu, Chang-Mo; Lee, D.-Y.; Lee, Nam C.; Kim, Y.-H.

    2007-01-01

    The influence of anisotropic ion pressure on the dust ion acoustic solitary wave (DIASW) and the double layer (DL) obliquely propagating to a magnetic field are investigated by using the Sagdeev potential. The anisotropic ion pressure is defined by applying the Chew-Goldberger-Low (CGL) theory, p-perpendicular=p-perpendicular 0 n and p-parallel=p-parallel 0 n 3 , where n is the normalized ion density. The solutions of DIASWs and DLs obliquely propagating to an external magnetic field are obtained in the small amplitude limit. It is found that the perpendicular component of anisotropic ion pressure works differently from that of the parallel component on the DIASWs in a magnetized dusty plasma, deviating from a straight extension of the isotropic pressure effect

  13. Theoretical study of laser-excited Mach cones in dusty plasmas

    International Nuclear Information System (INIS)

    Hou Lujing; Wang Younian; Miskovic, Z.L.

    2004-01-01

    A two-dimensional hydrodynamic model for a monolayer of dust particles is used to study the Mach cones excited by a moving laser beam through dusty plasmas. Numerical results for the density perturbation and the velocity distribution of dust particles exhibit both compressional and shear-wave Mach cones. It is found that the compressional Mach cones exist in cases of both supersonic and subsonic excitations, and that they consist of multiple lateral or transverse wakes. On the other hand, realization of single shear-wave Mach cones depends closely on the excitation technique, the laser scanning speed, and the discharge pressures. It is found that, when the scanning direction of the laser beam is perpendicular to the laser force, a transition from multiple compressional Mach cones to a single shear Mach cone can be achieved either by lowering the scanning speed or by increasing the discharge pressures

  14. Non-Markovian dynamics of dust charge fluctuations in dusty plasmas

    Science.gov (United States)

    Asgari, H.; Muniandy, S. V.; Ghalee, Amir; Ghalee

    2014-06-01

    Dust charge fluctuates even in steady-state uniform plasma due to the discrete nature of the charge carriers and can be described using standard Langevin equation. In this work, two possible approaches in order to introduce the memory effect in dust charging dynamics are proposed. The first part of the paper provides the generalization form of the fluctuation-dissipation relation for non-Markovian systems based on generalized Langevin equations to determine the amplitudes of the dust charge fluctuations for two different kinds of colored noises under the assumption that the fluctuation-dissipation relation is valid. In the second part of the paper, aiming for dusty plasma system out of equilibrium, the fractionalized Langevin equation is used to derive the temporal two-point correlation function of grain charge fluctuations which is shown to be non-stationary due to the dependence on both times and not the time difference. The correlation function is used to derive the amplitude of fluctuations for early transient time.

  15. The effect of a dust size distribution on electrostatic sheaths in unmagnetized dusty plasmas

    International Nuclear Information System (INIS)

    Benlemdjaldi, D.; Tahraoui, A.; Hugon, R.; Bougdira, J.

    2013-01-01

    In this work, the structure of plasma sheaths in presence of dust particles with different sizes is investigated numerically in a multifluid framework, where the dust size distribution is modeled by Gauss' law. For this, we have established a 1D, stationary, unmagnetized, and weakly collisional electronegative dusty plasma sheath model. The electrons and negative ions are considered in a local thermodynamic equilibrium, therefore, described by a Boltzmann distribution. On the other hand, positive ions and dust grains are described by fluid equations. The charging process is described by the orbit motion limited model. It is shown that taking into account dust grains with different sizes reduces considerably the sheath thickness. The behavior of dust surface potential is not affected, but the dust charge number is reduced, as well as the electrostatic force. It results in a decrease of layered structure. The presence of negative ions makes the structure of the electrostatic potential more oscillatory. The other physical parameters are also analyzed and discussed.

  16. Symbolic computation on the multi-soliton-like solutions of the cylindrical Kadomtsev-Petviashvili equation from dusty plasmas

    International Nuclear Information System (INIS)

    Li Juan; Zhang Haiqiang; Xu Tao; Zhang Yaxing; Hu Wei; Tian Bo

    2007-01-01

    Considering the transverse perturbation and axially non-planar geometry, the cylindrical Kadomtsev-Petviashvili (KP) equation is investigated in this paper, which can describe the propagation of dust-acoustic waves in the dusty plasma with two-temperature ions. Through imposing the decomposition method, such a (2+1)-dimensional equation is decomposed into two variable-coefficient (1+1)-dimensional integrable equations of the same hierarchy. Furthermore, three kinds of Darboux transformations (DTs) for these two (1+1)-dimensional equations are constructed. Via the three DTs obtained, the multi-soliton-like solutions of the cylindrical KP equation are explicitly presented. Especially, the one- and two-parabola-soliton solutions are discussed by several figures and some effects resulting from the physical parameters in the dusty plasma and transverse perturbation are also shown

  17. Time evolution of nonplanar dust ion-acoustic solitary waves in a charge varying dusty plasma with superthermal electrons

    Energy Technology Data Exchange (ETDEWEB)

    Mayout, Saliha; Tribeche, Mouloud, E-mail: mouloudtribeche@yahoo.fr [Plasma Physics Group (PPG), Theoretical Physics Laboratory (TPL), Faculty of Sciences- Physics, University of Bab-Ezzouar, U.S.T.H.B, B.P. 32, El Alia, Algiers 16111 (Algeria); Sahu, Biswajit [Department of Mathematics, West Bengal State University, Barasat, Kolkata-700126 (India)

    2015-12-15

    A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons, and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries equation is derived. It is shown that the propagation characteristics of the cylindrical and spherical DIA solitary waves significantly differ from those of their one-dimensional counterpart.

  18. Study on the layered dusty plasma structures in the summer polar mesopause

    Directory of Open Access Journals (Sweden)

    Hui Li

    2010-09-01

    Full Text Available Traditional hydrodynamic equations are adopted to build a one-dimensional theoretical model to study the effect of gravity wave on layered dusty plasma structures formation and evolution near the polar summer mesospause region associated with polar mesosphere summer echoes (PMSE. The proposed mechanism gives consideration to the charged ice particle motion by the gravity wave modulation, making a significant contribution to the vertical transport of heavy ice particles and convergence into thin layers. And numerical results show that the pattern of the multi-layer structure depends on the ration of the initial ice particles density distribution to the vertical wavelength of the gravity waves, the ice particle size and the wind velocity caused by gravity wave. Also, the variation of ion density distribution under the influence of gravity wave has also been examined. Finally, the electron density depletions (bite-outs layers has been simulated according to the charge conservation laws, and the results are compared to the ECT02 rocket sounding data, which agree well with the measuring.

  19. Identification of Accretion as Grain Growth Mechanism in Astrophysically Relevant Water–Ice Dusty Plasma Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, Ryan S.; Chai, Kil-Byoung; Bellan, Paul M. [Applied Physics and Materials Science, Caltech, Pasadena, CA 91125 (United States)

    2017-03-01

    The grain growth process in the Caltech water–ice dusty plasma experiment has been studied using a high-speed camera and a long-distance microscope lens. It is observed that (i) the ice grain number density decreases fourfold as the average grain major axis increases from 20 to 80 μ m, (ii) the major axis length has a log-normal distribution rather than a power-law dependence, and (iii) no collisions between ice grains are apparent. The grains have a large negative charge resulting in strong mutual repulsion and this, combined with the fractal character of the ice grains, prevents them from agglomerating. In order for the grain kinetic energy to be sufficiently small to prevent collisions between ice grains, the volumetric packing factor (i.e., ratio of the actual volume to the volume of a circumscribing ellipsoid) of the ice grains must be less than ∼0.1 depending on the exact relative velocity of the grains in question. Thus, it is concluded that direct accretion of water molecules is very likely to dominate the observed ice grain growth.

  20. Effects of atmospheric dusty plasma generated by natural radioactivity on the atmosphere thermodynamics and electrodynamics

    Science.gov (United States)

    Pulinets, Sergey; Ouzounov, Dimitar

    Natural radioactivity of the Earth through ionization creates a large number of new ions in the boundary layer of atmosphere from the ground surface up to near 1 km altitude. In specific conditions the ion concentration can reach 10 (6) -10 (7) cm (-3) . This sharp increase of ion concentration leads to the process of so called Ion Induced Nucleation (IIN) when due to ion's hydration the large complex ion clusters are formed with the very low recombination rate, i.e. we deal with formation of dusty atmospheric plasma in the boundary layer. Our theoretical estimates and experimental results of ground based and remote sensing satellite monitoring revealed two main consequences of IIN: release of large amount of the latent heat leading to the changes of air temperature and humidity, and sharp changes of air conductivity in the vertical column of the Global Electric Circuit (GEC) leading to formation of large scale irregularities of electron concentration in the ionosphere. The mechanism has universal character and its effects are observed in different natural and anthropogenic disasters like hurricanes, earthquakes, volcano eruption, artificial ionization, emergencies at atomic power plants, etc. Experimental evidences for many cases demonstrating effects of IIN are presented.

  1. Stress-induced microcracking and cooperative motion of cold dusty plasma liquids.

    Science.gov (United States)

    Yang, Chi; I, Lin

    2014-04-01

    We investigate the microresponse of the quasi-two-dimensional dusty plasma liquid around freezing to the shear force from a laser beam through the center of the liquid cluster. It is found that the cold liquid can be viewed as a patchwork of crystalline ordered domains (CODs) which are solidlike but can be cracked and rearranged by weak thermal agitation and external stress, through COD rotations and drifting. Under weak external stress comparable to thermal agitation, the laser zone is not the preferred region mastering cracking initiation. CODs in the laser zone can either break locally, or sustain and propagate the stress to remote regions for cracking, in the form of intermittent bursts. The COD rotation and drifting induced by the persistent torques and momentum from the stress causes the formation of the center shear band with a higher longitudinal speed. Increasing stress can enhance cracking initiation around the shear zone and then spread to other remote regions. It deteriorates the local structural order and causes strong shear banding dominated by longitudinal cooperative hopping.

  2. Jeans instability in collisional strongly coupled dusty plasma with radiative condensation and polarization force

    Energy Technology Data Exchange (ETDEWEB)

    Prajapati, R. P., E-mail: prajapati-iter@yahoo.co.in; Bhakta, S. [Department of Pure and Applied Physics, Guru Ghasidas Central University, Bilaspur-495009 (C.G.) (India); Chhajlani, R. K. [Retired from School of Studies in Physics, Vikram University, Ujjain-456010 (M.P.) (India)

    2016-05-15

    The influence of dust-neutral collisions, polarization force, and electron radiative condensation is analysed on the Jeans (gravitational) instability of partially ionized strongly coupled dusty plasma (SCDP) using linear perturbation (normal mode) analysis. The Boltzmann distributed ions, dynamics of inertialess electrons, charged dust and neutral particles are considered. Using the plane wave solutions, a general dispersion relation is derived which is modified due to the presence of dust-neutral collisions, strong coupling effect, polarization force, electron radiative condensation, and Jeans dust/neutral frequencies. In the long wavelength perturbations, the Jeans instability criterion depends upon strong coupling effect, polarization interaction parameter, and thermal loss, but it is independent of dust-neutral collision frequency. The stability of the considered configuration is analysed using the Routh–Hurwitz criterion. The growth rates of Jeans instability are illustrated, and stabilizing influence of viscoelasticity and dust-neutral collision frequency while destabilizing effect of electron radiative condensation, polarization force, and Jeans dust-neutral frequency ratio is observed. This work is applied to understand the gravitational collapse of SCDP with dust-neutral collisions.

  3. Effect of trapped electron on the dust ion acoustic waves in dusty plasma using time fractional modified Korteweg-de Vries equation

    International Nuclear Information System (INIS)

    Nazari-Golshan, A.; Nourazar, S. S.

    2013-01-01

    The time fractional modified Korteweg-de Vries (TFMKdV) equation is solved to study the nonlinear propagation of small but finite amplitude dust ion-acoustic (DIA) solitary waves in un-magnetized dusty plasma with trapped electrons. The plasma is composed of a cold ion fluid, stationary dust grains, and hot electrons obeying a trapped electron distribution. The TFMKdV equation is derived by using the semi-inverse and Agrawal's methods and then solved by the Laplace Adomian decomposition method. Our results show that the amplitude of the DIA solitary waves increases with the increase of time fractional order β, the wave velocity v 0 , and the population of the background free electrons λ. However, it is vice-versa for the deviation from isothermality parameter b, which is in agreement with the result obtained previously

  4. Quasilongitudinal soliton in a two-dimensional strongly coupled complex dusty plasma in the presence of an external magnetic field.

    Science.gov (United States)

    Ghosh, Samiran

    2014-09-01

    The propagation of a nonlinear low-frequency mode in two-dimensional (2D) monolayer hexagonal dusty plasma crystal in presence of external magnetic field and dust-neutral collision is investigated. The standard perturbative approach leads to a 2D Korteweg-de Vries (KdV) soliton for the well-known dust-lattice mode. However, the Coriolis force due to crystal rotation and Lorentz force due to magnetic field on dust particles introduce a linear forcing term, whereas dust-neutral drag introduce the usual damping term in the 2D KdV equation. This new nonlinear equation is solved both analytically and numerically to show the competition between the linear forcing and damping in the formation of quasilongitudinal soliton in a 2D strongly coupled complex (dusty) plasma. Numerical simulation on the basis of the typical experimental plasma parameters and the analytical solution reveal that the neutral drag force is responsible for the usual exponential decay of the soliton, whereas Coriolis and/or Lorentz force is responsible for the algebraic decay as well as the oscillating tail formation of the soliton. The results are discussed in the context of the plasma crystal experiment.

  5. Finite size effects in the static structure factor of dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Davletov, A. E., E-mail: askar@physics.kz; Yerimbetova, L. T.; Mukhametkarimov, Ye. S.; Ospanova, A. K. [Department of Physics and Technology, Al-Farabi Kazakh National University, Al-Farabi av. 71, 050040 Almaty (Kazakhstan)

    2014-07-15

    Based on the previously developed pseudopotential model of the dust particles interaction, which takes into account both the finite size and screening effects, the equilibrium distribution functions are investigated in a broad range of plasma parameters. The treatment stems entirely from the renormalization theory of plasma particles interactions which leads to the so-called generalized Poisson-Boltzmann equation. In particular, an analytical expression for the static structure factor of the dust particles is proposed and its non-monotonic behavior in the hyper-netted chain approximation is found in a specified domain of plasma parameters to indicate the formation of short- or even long-range order in the system.

  6. Dust acoustic solitons in a charge varying dusty plasma in the presence of ion nonthermality and background nonextensivity

    Energy Technology Data Exchange (ETDEWEB)

    Benzekka, Moufida; Tribeche, Mouloud [Faculty of Sciences-Physics, Theoretical Physics Laboratory (TPL), University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria)

    2013-08-15

    Dust acoustic (DA) solitons are addressed in a charge varying dusty plasma in the presence of ion nonthermality and background nonextensivity. A physically meaningful nonthermal nonextensive ion distribution is outlined. The correct non-Maxwellian ion charging current is derived based on the orbit-limited motion theory. Under grain-current balance, the variable dust charge is expressed in terms of the Lambert function. It is found that nonthermality and its nonextensive nature may act concurrently and influence the restoring force and hence the soliton profile. Due to the flexibility provided by the nonextensive parameter, we think that our model should provide a better fit of the space observations.

  7. Analysis of the transmission characteristics of radio waves in inhomogeneous weakly ionized dusty plasma sheath based on high order SO-DGTD

    Science.gov (United States)

    Wei, Bing; Li, Linqian; Yang, Qian; Ge, Debiao

    Based on high order hierarchical basis function and the ideal of shift operator, shift operator discontinuous Galerkin time domain (SO-DGTD) technique for dealing with weakly ionized dusty plasma electromagnetic problems is proposed. Lagrange interpolation is used to transform the metallic blunt cone aircraft with weakly ionized dusty plasma sheath from geometric model built by COMSOL to electromagnetic computational model. In the case of two-dimensional transverse magnetic (TM) wave, the electromagnetic wave propagation in weakly ionized dusty plasma sheath is calculated by SO-DGTD technique. And then, the influence of dust particle concentration and dust radius on the radio wave transmission is analyzed, and the radio wave propagation characteristics pass through the sheath is compared with the flight speed and height change.

  8. Collective dynamics of large aspect ratio dusty plasma in an inhomogeneous plasma background: Formation of the co-rotating vortex series

    Science.gov (United States)

    Choudhary, Mangilal; Mukherjee, S.; Bandyopadhyay, P.

    2018-02-01

    In this paper, the collective dynamics of large aspect ratio dusty plasma is studied over a wide range of discharge parameters. An inductively coupled diffused plasma, which creates an electrostatic trap to confine the negatively charged grains, is used to form a large volume (or large aspect ratio) dusty plasma at low pressure. For introducing the dust grains into the potential well, a unique technique using secondary DC glow discharge plasma is employed. The dust dynamics is recorded in a two-dimension (2D) plane at a given axial location. The dust fluid exhibits wave-like behavior at low pressure (p 3 W). The mixed motion, waves and vortices, is observed at an intermediate gas pressure (p ˜ 0.08 mbar) and low power (P 0.1 mbar), the clockwise and anti-clockwise co-rotating vortex series are observed on edges of the dust cloud, whereas the particles in the central region show random motion. These vortices are only observed above the threshold width of the dust cloud. The occurrence of the co-rotating vortices is understood on the basis of the charge gradient of dust particles, which is orthogonal to the gravity. The charge gradient is a consequence of the plasma inhomogeneity from the central region to the outer edge of the dust fluid. Since a vortex has the characteristic size in the dissipative medium; therefore, a series of the co-rotating vortex on both sides of dusty plasma is observed. The experimental results on the vortex formation and its multiplicity are compared to an available theoretical model and are found to be in close agreement.

  9. Electron-ion attachment induced instability of dust acoustic waves in the presence of ionization in a charge varying collisional dusty plasma

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Khan, Manoranjan

    2006-01-01

    Low frequency electrostatic dust acoustic wave (DAW) instability with a significant background pressure of neutrals has been investigated in a collisional dusty plasma incorporating the dust charge relaxation and electron-ion attachment (recombination) onto dust grains using a self consistent theory. A long wavelength mode is found to be unstable due to electron-ion attachment on to the dust grains. Applications to experimental observations of low frequency fluctuation and the relevance of these results to 'void' in a laboratory gas discharge dusty plasma are briefly discussed

  10. Symbolic computation on integrable decompositions for the cylindrical Kadomtsev-Petviashvili equation from dusty plasmas and Bose-Einstein condensates

    International Nuclear Information System (INIS)

    Li Juan; Xu Tao; Zhang Haiqiang; Gao Yitian; Tian Bo

    2008-01-01

    In this paper, the cylindrical Kadomtsev-Petviashvili (KP) equation arising from dusty plasmas and Bose-Einstein condensates is investigated by the decomposition method. Through the nonlinearization of a single Lax pair, this equation is decomposed into a generalized variable-coefficient Burgers equation and its third-order extension, and then a series of analytic soliton-like solutions are obtained. Furthermore, with the aid of symbolic computation, a symmetry potential constraint in terms of the squared eigenfunctions is proposed to nonlinearize two symmetry Lax pairs into the first two variable-coefficient 2N-coupled soliton systems in the same hierarchy. Based on the Lax representation for these two decomposed soliton systems, a Darboux transformation is constructed to iteratively generate the multi-soliton-like solutions. Via the obtained analytic soliton-like solutions, the graphical analysis is devoted to the one-parabola soliton structure, compressive and rarefactive soliton resonance phenomena occurring in dusty plasmas and Bose-Einstein condensates

  11. Dust-acoustic shock waves in a charge varying electronegative magnetized dusty plasma with nonthermal ions: Application to Halley Comet plasma

    Energy Technology Data Exchange (ETDEWEB)

    Tribeche, Mouloud; Bacha, Mustapha [Plasma Physics Group (PPG), Theoretical Physics Laboratory (TPL), Faculty of Physics, University of Bab-Ezzouar, USTHB, B. P. 32, El Alia, Algiers 16111 (Algeria)

    2013-10-15

    Weak dust-acoustic waves (DAWs) are addressed in a nonthermal charge varying electronegative magnetized dusty plasmas with application to the Halley Comet. A weakly nonlinear analysis is carried out to derive a Korteweg-de Vries-Burger equation. The positive ion nonthermality, the obliqueness, and magnitude of the magnetic field are found to modify the dispersive and dissipative properties of the DA shock structure. Our results may aid to explain and interpret the nonlinear oscillations that may occur in the Halley Comet Plasma.

  12. Dissipative dust-acoustic shock waves in a varying charge electronegative magnetized dusty plasma with trapped electrons

    Energy Technology Data Exchange (ETDEWEB)

    Bacha, Mustapha [Faculty of Physics, Theoretical Physics Laboratory, Plasma Physics Group, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria); Tribeche, Mouloud, E-mail: mouloudtribeche@yahoo.fr, E-mail: mtribeche@usthb.dz [Faculty of Physics, Theoretical Physics Laboratory, Plasma Physics Group, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria); Algerian Academy of Sciences and Technologies, Algiers (Algeria)

    2016-08-15

    The combined effects of an oblique magnetic field and electron trapping on dissipative dust-acoustic waves are examined in varying charge electronegative dusty plasmas with application to the Halley Comet plasma (∼10{sup 4} km from the nucleus). A weakly nonlinear analysis is carried out to derive a modified Korteweg-de Vries-Burger-like equation. Making use of the equilibrium current balance equation, the physically admissible values of the electron trapping parameter are first constrained. We then show that the Burger dissipative term is solely due to the dust charge variation process. It is found that an increase of the magnetic field obliqueness or a decrease of its magnitude renders the shock structure more dispersive.

  13. Solitary waves of the Kadomstev-Petviashvili equation in warm dusty plasma with variable dust charge, two temperature ion and nonthermal electron

    International Nuclear Information System (INIS)

    Pakzad, Hamid Reza

    2009-01-01

    The propagation of nonlinear waves in warm dusty plasmas with variable dust charge, two temperature ion and nonthermal electron is studied. By using the reductive perturbation theory, the Kadomstev-Petviashivili (KP) equation is derived. Existence of rarefactive and compressive solitons is analyzed.

  14. Dust-acoustic shock waves in a dusty plasma with non-thermal ions and super-thermal electrons

    Science.gov (United States)

    Emamuddin, M.; Mamun, A. A.

    2018-01-01

    The propagation of dust-acoustic shock waves (DASWs) in a collisionless unmagnetized dusty plasma (containing super-thermal electrons of two distinct temperatures, non-thermal ions, and a negatively charged viscous dust fluid) has been theoretically investigated by deriving and solving the nonlinear Burgers' equation. It has been observed that the viscous force acting on the dust fluid is a source of dissipation, and is responsible for the formation of DASWs, and that the basic features (viz., amplitude, polarity, width, etc.) of the DASWs are significantly modified by the presence of super-thermal electrons and non-thermal ions. The possible applications of this investigation in Earth's mesosphere, the solar atmosphere, Saturn's magnetosphere, etc., have also been briefly addressed.

  15. Preliminary Study on Active Modulation of Polar Mesosphere Summer Echoes with the Radio Propagation in Layered Space Dusty Plasma

    Science.gov (United States)

    Zhou, Shengguo; Li, Hailong; Fu, Luyao; Wang, Maoyan

    2016-06-01

    Radar echoes intensity of polar mesosphere summer echoes (PMSE) is greatly affected by the temperature of dusty plasma and the frequency of electromagnetic wave about the radar. In this paper, a new method is developed to explain the active experiment results of PMSE. The theory of wave propagation in a layered media is used to study the propagation characteristics of an electromagnetic wave at different electron temperatures. The simulation results show that the variation tendency of the reflected power fraction almost agrees with the results observed by radar in the European Incoherent Scatter Scientific Association (EISCAT). The radar echoes intensity of PMSE greatly decreases with the increase of the radio frequency and the enhancement of the electron temperature. supported by National Natural Science Foundation of China (Nos. 41104097 and 41304119) and by the National Key Laboratory of Electromagnetic Environment, China Research Institute of Radiowave Propagation (CRIRP)

  16. Kinematic dust viscosity effect on linear and nonlinear dust-acoustic waves in space dusty plasmas with nonthermal ions

    Energy Technology Data Exchange (ETDEWEB)

    El-Hanbaly, A. M.; Sallah, M., E-mail: msallahd@mans.edu.eg [Mansoura University, Physics Department, Faculty of Science (Egypt); El-Shewy, E. K. [Taibah University Al-Madinah Al-Munawarah, Department of Physics (Saudi Arabia); Darweesh, H. F. [Mansoura University, Physics Department, Faculty of Science (Egypt)

    2015-10-15

    Linear and nonlinear dust-acoustic (DA) waves are studied in a collisionless, unmagnetized and dissipative dusty plasma consisting of negatively charged dust grains, Boltzmann-distributed electrons, and nonthermal ions. The normal mode analysis is used to obtain a linear dispersion relation illustrating the dependence of the wave damping rate on the carrier wave number, the dust viscosity coefficient, the ratio of the ion temperature to the electron temperatures, and the nonthermal parameter. The plasma system is analyzed nonlinearly via the reductive perturbation method that gives the KdV-Burgers equation. Some interesting physical solutions are obtained to study the nonlinear waves. These solutions are related to soliton, a combination between a shock and a soliton, and monotonic and oscillatory shock waves. Their behaviors are illustrated and shown graphically. The characteristics of the DA solitary and shock waves are significantly modified by the presence of nonthermal (fast) ions, the ratio of the ion temperature to the electron temperature, and the dust kinematic viscosity. The topology of the phase portrait and the potential diagram of the KdV-Burgers equation is illustrated, whose advantage is the ability to predict different classes of traveling wave solutions according to different phase orbits. The energy of the soliton wave and the electric field are calculated. The results in this paper can be generalized to analyze the nature of plasma waves in both space and laboratory plasma systems.

  17. Effects of ionization and ion loss on dust ion-acoustic solitary waves in a collisional dusty plasma with suprathermal electrons

    Energy Technology Data Exchange (ETDEWEB)

    Mayout, Saliha; Gougam, Leila Ait [Faculty of Physics, Theoretical Physics Laboratory, Plasma Physics Group, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria); Tribeche, Mouloud, E-mail: mouloudtribeche@yahoo.fr, E-mail: mtribeche@usthb.dz [Faculty of Physics, Theoretical Physics Laboratory, Plasma Physics Group, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria); Algerian Academy of Sciences and Technologies, Algiers (Algeria)

    2016-03-15

    The combined effects of ionization, ion loss, and electron suprathermality on dust ion-acoustic solitary waves in a collisional dusty plasma are examined. Carrying out a small but finite amplitude analysis, a damped Korteweg-de Vries (dK–dV) equation is derived. The damping term decreases with the increase of the spectral index and saturates for Maxwellian electrons. Choosing typical plasma parameters, the analytical approximate solution of the dK-dV equation is numerically analyzed. We first neglect the ionization and ion loss effects and account only for collisions to estimate the relative importance between these damping terms which can act concurrently. Interestingly, we found that as the suprathermal character of the electrons becomes important, the strength of the collisions related dissipation becomes more important and causes the dust ion-acoustic solitary wave amplitude to decay more rapidly. Moreover, the collisional damping may largely prevail over the ionization and ion loss related damping. The latter becomes more effective as the electrons evolve far away from their thermal equilibrium. Our results complement and provide new insights into previously published work on this problem.

  18. Dusty Plasma Modeling of the Fusion Reactor Sheath Including Collisional-Radiative Effects

    International Nuclear Information System (INIS)

    Dezairi, Aouatif; Samir, Mhamed; Eddahby, Mohamed; Saifaoui, Dennoun; Katsonis, Konstantinos; Berenguer, Chloe

    2008-01-01

    The structure and the behavior of the sheath in Tokamak collisional plasmas has been studied. The sheath is modeled taking into account the presence of the dust 2 and the effects of the charged particle collisions and radiative processes. The latter may allow for optical diagnostics of the plasma.

  19. Computing the complex : Dusty plasmas in the presence of magnetic fields and UV radiation

    NARCIS (Netherlands)

    Land, V.

    2007-01-01

    About 90% of the visible universe is plasma. Interstellar clouds, stellar cores and atmospheres, the Solar wind, the Earth's ionosphere, polar lights, and lightning are all plasma; ionized gases, consisting of electrons, ions, and neutrals. Not only many industries, like the microchip and solar cell

  20. Diagnostics in dusty C-H-O plasmas with diamond and graphitic nanoparticle generation

    International Nuclear Information System (INIS)

    Gries, T; Vandenbulcke, L; De Persis, S; Rouzaud, J N

    2010-01-01

    A decrease in electron density and a strong increase of electron energy, which induce the enhancement of excitation rates, have been observed in CH 4 -CO 2 plasmas when the inlet methane concentration is high enough and the input microwave power sufficiently low. Together with the decrease in the electron density with plasma duration, they are characteristic of dust formation in these plasmas. In these conditions, the formation of hydrocarbon radicals which are well known precursors of soot and the formation of first stable aromatics are reported, as observed by molecular beam mass spectrometry. Modelling of the chemistry in the plasma is carried out, which can also predict the formation of low concentrations of polyaromatic hydrocarbons. These species could be involved in the homogeneous nucleation process of carbon. As a function of the plasma duration, various carbon nanostructures are observed in the particles collected downstream of the plasma. For short durations, nanodiamond grains are formed with the size range 15-100 nm. They are composed of diamond nanocrystals of about 2-10 nm in size; these values are generally observed for all diamond nanocrystals formed in extraterrestrial and terrestrial conditions. For longer plasma durations, sp 2 -hybridized carbons are obtained. Their structure varies from soot to more ordered graphitic carbons nearly similar to 'onions' and structures similar to those observed in tokamaks. The control of the size and the microstructure of the nanodiamond grains are especially important as this could open possibilities for applications in a wide range of fields.

  1. Propagation of nonplanar dust-acoustic envelope solitary waves in a two-ion-temperature dusty plasma

    International Nuclear Information System (INIS)

    Xue Jukui

    2004-01-01

    The evolution of the cylindrical and spherical dust-acoustic envelope solitary wave (DAESW) in an unmagnetized dusty plasma consisting of negatively charged dust fluid and ions of two different temperatures is investigated. By using the reductive perturbation method, the cylindrical and spherical geometry-modified nonlinear Schroedinger equation (GMNLSE) is obtained. The change of the DAESW amplitude due to the cylindrical and spherical geometry effects is deduced analytically. It is shown that there exist two time ranges. On the other hand, the wave amplitude changes with time τ as (τ 0 /τ) m/2 when the geometry effect is stronger and as (τ 0 /τ) m when the geometry effect is weaker, where τ 0 is the initial time, and m=1 (2) refers to the cylindrical (spherical) case. The theoretical results are verified by the numerical calculation for the GMNLSE. The modulational instability of dust-acoustic waves governed by the GMNLSE is also presented. It is shown that the propagation of the DAESW in cylindrical geometry, spherical geometry, and planar one-dimensional geometry are very different. The presence of a second component of ions would modify the nature of the modulation instabilities

  2. Low-frequency electrostatic shock excitations in a multi-component dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ferdousi, M.; Miah, M.R.; Sultana, S.; Mamun, A.A., E-mail: mariyaferdousi@gmail.com [Department of Physics, Jahangirnagar University, Savar (Bangladesh)

    2015-10-01

    Dust-acoustic shock waves are investigated in a four-component plasma consisting of arbitrarily charged inertial dusts, Boltzmann distributed negatively charged heavy ions, positively charged light ions, and electrons. The reductive perturbation technique is employed in order to derive the nonlinear time evolution Burgers-type equation. The properties of dust-acoustic shock waves are analysed via the solution of Burgers equation. It is observed that the basic features of dust-acoustic shock waves are significantly modified due to the influence of arbitrarily charged dusts, Maxwellian electrons, number density and temperatures of heavier and lighter ions, and dust kinematic viscosity. Both polarity (positive and negative potential) shock waves are also found to exists in the plasma under consideration in this manuscript. The findings of this investigation may be used in understanding the dust-acoustic wave properties in both laboratory and space plasmas. (author)

  3. Low-frequency electrostatic shock excitations in a multi-component dusty plasma

    International Nuclear Information System (INIS)

    Ferdousi, M.; Miah, M.R.; Sultana, S.; Mamun, A.A.

    2015-01-01

    Dust-acoustic shock waves are investigated in a four-component plasma consisting of arbitrarily charged inertial dusts, Boltzmann distributed negatively charged heavy ions, positively charged light ions, and electrons. The reductive perturbation technique is employed in order to derive the nonlinear time evolution Burgers-type equation. The properties of dust-acoustic shock waves are analysed via the solution of Burgers equation. It is observed that the basic features of dust-acoustic shock waves are significantly modified due to the influence of arbitrarily charged dusts, Maxwellian electrons, number density and temperatures of heavier and lighter ions, and dust kinematic viscosity. Both polarity (positive and negative potential) shock waves are also found to exists in the plasma under consideration in this manuscript. The findings of this investigation may be used in understanding the dust-acoustic wave properties in both laboratory and space plasmas. (author)

  4. Propagation of ion-acoustic waves in a dusty plasma with non ...

    Indian Academy of Sciences (India)

    isothermality of electrons, Mach numbers etc. have considerable impact on the amplitude as well as the width of the solitary waves. Dependence of soliton profiles ... great deal of interest in numerous collective processes in a plasma contaminated by the charged dust grains encountered very often in space and laboratory ...

  5. Fast and interrupted expansion in cyclic void growth in dusty plasma

    International Nuclear Information System (INIS)

    Van de Wetering, F M J H; Brooimans, R J C; Nijdam, S; Beckers, J; Kroesen, G M W

    2015-01-01

    Low-pressure acetylene plasmas are able to spontaneously form dust particles. This will result in a dense cloud of solid particles that is levitated in the plasma. The formed particles can grow up to micrometers. We observed a spontaneous interruption in the expansion of the so-called dust void. A dust void is a macroscopic region in the plasma that is free of nanoparticles. The phenomenon is periodical and reproducible. We refer to the expansion interruption as ‘hiccup’. The expanding void is an environment in which a new cycle of dust particle formation can start. At a certain moment in time, this cycle reaches the (sudden) coagulation phase and as a result the void will temporarily shrink. To substantiate this reasoning, the electron density is determined non-intrusively using microwave cavity resonance spectroscopy. Moreover, video imaging of laser light scattering of the dust particles provides their spatial distribution. The emission intensity of a single argon transition is measured similarly. Our results support the aforementioned hypothesis for what happens during the void hiccup. The void dynamics preceding the hiccup are modeled using a simple analytical model for the two dominant forces (ion drag and electric) working on a nanoparticle in a plasma. The model results qualitatively reproduce the measurements. (paper)

  6. Dusty space plasma diagnosis using temporal behavior of polar mesospheric summer echoes during active modification

    Directory of Open Access Journals (Sweden)

    A. Mahmoudian

    2011-11-01

    Full Text Available The objective of this paper is to study the effect of different plasma and dust parameters on Polar Mesospheric Summer Echoes (PMSE temporal behavior after turn-on and turn-off of radio wave heating and to use these responses to diagnose the properties of the dust layer. The threshold radar frequency and dust parameters for the enhancement or suppression of radar echoes after radio wave heating turn-on are investigated for measured mesospheric plasma parameters. The effect of parameters such as the electron temperature enhancement during heating, dust density, dust charge polarity, ion-neutral collision frequency, electron density and dust radius on the temporal evolution of electron irregularities associated with PMSE are investigated. The possible diagnostic information for various charged dust and background plasma quantities using the temporal behavior of backscattered radar power in active experiments is discussed. The computational results are used to make predictions for PMSE active modification experiments at 7.9, 56, 139, 224 and 930 MHz corresponding to existing radar facilities. Data from a 2009 VHF (224 MHz experiment at EISCAT is compared with the computational model to obtain dust parameters in the PMSE.

  7. Light scattering measurements with Titan's aerosols analogues produced by dusty plasma

    Science.gov (United States)

    Hadamcik, E.; Renard, J.-B.; Szopa, C.; Cernogora, G.; Levasseur-Regourd, A. C.

    The Titan s atmosphere contains solid aerosols produced by the photochemistry of nitrogen and methane These aerosols are at the origin of the characteristic brown yellow colour of Titan During the descent of the Huygens probe the 14 th January 2005 optical measurements of the Titan s haze and Titan s surface have been done In order to explain the obtained results laboratory simulations are necessary We produce analogues of the Titan s aerosols in a RF capacitively coupled low-pressure plasma in a N 2 --CH 4 mixture representative of the Titan s atmosphere Szopa et al 2006 Szopa et al this conference The morphology of the produced solid aerosols is observed by SEM analyses They are quasi spherical and their mean size is function of the plasma conditions Moreover their colour changes from yellow to brown as a function of CH 4 ratio in the plasma In order to have information on the optical properties of the produced aerosols measurements have been performed with the PROGRA2 experiment Renard et al 2002 The PROGRA2 experiment measures the phase dependence of the linear polarization of the light scattered by dust particles for two wavelengths 543 5 nm and 632 8 nm The particles are lifted either in microgravity in the CNES ESA dedicated airplane or by an air-draught in ground-based conditions The aim of this work is to build a database for further modelling of the optical properties of Titan s in connection with the Huygens data These particles have also an astrophysical interest as organic compounds Hadamcik et

  8. Effect of magnetic field on the wave dispersion relation in three-dimensional dusty plasma crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xuefeng [School of Mathematical Sciences, Dalian University of Technology, Dalian 116024 (China); Wang Zhengxiong [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

    2012-07-15

    Three-dimensional plasma crystals under microgravity condition are investigated by taking into account an external magnetic field. The wave dispersion relations of dust lattice modes in the body centered cubic (bcc) and the face centered cubic (fcc) plasma crystals are obtained explicitly when the magnetic field is perpendicular to the wave motion. The wave dispersion relations of dust lattice modes in the bcc and fcc plasma crystals are calculated numerically when the magnetic field is in an arbitrary direction. The numerical results show that one longitudinal mode and two transverse modes are coupled due to the Lorentz force in the magnetic field. Moreover, three wave modes, i.e., the high frequency phonon mode, the low frequency phonon mode, and the optical mode, are obtained. The optical mode and at least one phonon mode are hybrid modes. When the magnetic field is neither parallel nor perpendicular to the primitive wave motion, all the three wave modes are hybrid modes and do not have any intersection points. It is also found that with increasing the magnetic field strength, the frequency of the optical mode increases and has a cutoff at the cyclotron frequency of the dust particles in the limit of long wavelength, and the mode mixings for both the optical mode and the high frequency phonon mode increase. The acoustic velocity of the low frequency phonon mode is zero. In addition, the acoustic velocity of the high frequency phonon mode depends on the angle of the magnetic field and the wave motion but does not depend on the magnetic field strength.

  9. Three-dimensional cylindrical Kadomtsev-Petviashvili equation in a dusty electronegative plasma

    Science.gov (United States)

    Moslem, W. M.; Abdelsalam, U. M.; Sabry, R.; El-Shamy, E. F.; El-Labany, S. K.

    2010-08-01

    The hydrodynamic equations of positive and negative ions, Boltzmann electron density distribution and Poisson equation with stationary dust particles are used along with the reductive perturbation method to derive a three-dimensional cylindrical Kadomtsev-Petviashvili equation. The generalized expansion method, used to obtain a new class of solutions, admits a train of well-separated bell-shaped periodic pulses. At certain condition, these periodic pulses degenerate to solitary wave solutions. The effects of the physical parameters on the solitary pulses are examined. Finally, the present results should elucidate the properties of ion-acoustic solitary pulses in multi-component plasmas, particularly in Earth's ionosphere.

  10. Compressible Kolmogorov flow in strongly coupled dusty plasma using molecular dynamics and computational fluid dynamics. II. A comparative study

    Science.gov (United States)

    Gupta, Akanksha; Ganesh, Rajaraman; Joy, Ashwin

    2018-01-01

    In this paper, we perform comparative studies of compressible Kolmogorov flow in the two-dimensional strongly coupled dusty plasma by means of atomistic or molecular dynamics (MD) and continuum or computational fluid dynamics (CFD) methods. Recently, using MD simulation, generation of molecular shear heat at the atomistic level is shown to reduce the average coupling strength of the system and destruct the vortical structures. To suppress the molecular heat, a novel method of a thermostat, namely, the configurational thermostat is introduced by which the microscale heat generated by the shear flow has shown to be thermostatted out efficiently without compromising the large scale vortex dynamics. While using a configurational thermostat, it has been found that the growth rate obtained from both the studies is the same with the marginal difference. To make the comparison with the continuum fluid model, we perform the same study using the generalised hydrodynamic model, wherein molecular shear heating phenomena is completely absent, however, viscous dissipation is there at the macroscale level. For this purpose, an Advanced Generalised SPECTral Code has been developed to study the linear and nonlinear aspects of the Kolmogorov flow in the incompressible and compressible limit for viscoelastic fluids. All the phenomenological parameters used in CFD simulations have been calculated from MD simulations. Code is benchmarked against the eigen value solver in the linear regime. Linear growth-rates calculated from the phenomenological fluid model is found to be close to that obtained from MD simulation for the same set of input parameters. The transition from laminar to turbulent flow has been found at a critical value of Reynolds number Rc in both the macroscopic (CFD) and microscopic (MD) simulation. Rc in MD is smaller than the one obtained by CFD simulation. In the nonlinear regime of CFD, the mode becomes unstable and vortex formation happens earlier than in MD. The

  11. Solitary waves in dusty plasmas with weak relativistic effects in electrons and ions

    Energy Technology Data Exchange (ETDEWEB)

    Kalita, B. C., E-mail: bckalita123@gmail.com [Gauhati University, Department of Mathematics (India); Choudhury, M., E-mail: choudhurymamani@gmail.com [Handique Girls’ College, Department of Mathematics (India)

    2016-10-15

    Two distinct classes of dust ion acoustic (DIA) solitary waves based on relativistic ions and electrons, dust charge Z{sub d} and ion-to-dust mass ratio Q’ = m{sub i}/m{sub d} are established in this model of multicomponent plasmas. At the increase of mass ratio Q’ due to increase of relativistic ion mass and accumulation of more negative dust charges into the plasma causing decrease of dust mass, relativistic DIA solitons of negative potentials are abundantly observed. Of course, relativistic compressive DIA solitons are also found to exist simultaneously. Further, the decrease of temperature inherent in the speed of light c causes the nonlinear term to be more active that increases the amplitude of the rarefactive solitons and dampens the growth of compressive solitons for relatively low and high mass ratio Q’, respectively. The impact of higher initial streaming of the massive ions is observed to identify the point of maximum dust density N{sub d} to yield rarefactive relativistic solitons of maximum amplitude.

  12. Long-term spatio-temporal evolution of the dust distribution in dusty argon rf plasmas

    Science.gov (United States)

    Killer, Carsten; Greiner, Franko; Groth, Sebastian; Tadsen, Benjamin; Melzer, André

    2016-10-01

    The 3D dust distribution in dense dust clouds confined in argon rf plasmas is measured by a computed tomography (CT) technique based on the extinction of visible light. On the one hand, clouds of micron-sized particles were created by injecting standardized plastic particles into the plasma. On the other hand, sub-micron sized dust with well-defined properties is grown in situ in an argon acetylene mixture. Once created, both kinds of dust clouds decay in the course of minutes to hours. This decay is monitored by CT measurements. It is revealed that micro-dust clouds feature a drastic change of the dust distribution due to a size reduction of the dust. Dust clouds of sub-micron particles, in contrast, show a strong variation of the overall dust density while the relative dust distribution remains nearly unchanged. The evolution of the overall dust density is subject to two effects: the loss of particles due to an imperfect confinement and the reduction of the dust size via etching.

  13. Pseudopotential approach for dust acoustic solitary waves in dusty plasmas with kappa-distributed ions and electrons and dust grains having power law size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Gadadhar; Maitra, Sarit [Department of Mathematics, National Institute of Technology Durgapur, Durgapur (India)

    2015-04-15

    Sagdeev's pseudopotential method is used to study small as well as arbitrary amplitude dust acoustic solitons in a dusty plasma with kappa distributed electrons and ions with dust grains having power law size distribution. The existence of potential well solitons has been shown for suitable parametric region. The criterion for existence of soliton is derived in terms of upper and lower limit for Mach numbers. The numerical results show that the size distribution can affect the existence as well as the propagation characteristics of the dust acoustic solitons. The effect of kappa distribution is also highlighted.

  14. Effect of external magnetic field and variable dust electrical charge on the shape and propagation of solitons in the two nonthermal ions dusty plasma

    International Nuclear Information System (INIS)

    Ghalambor Dezfuly, S.; Dorranian, D.

    2012-01-01

    In this manuscript, the effect of dust electrical charge, nonthermal ions, and external magnetic field on the shape and propagation of solitons in dusty plasma with two nonthermal ions is studied theoretically. Using the reductive perturbation theory, the Zakharov-Kuznetsov equation for propagation of dust acoustic waves is extracted. Results show that external magnetic field does not affect the amplitude of solitary wave but width of solitons are effectively depend on the magnitude of external magnetic field. With increasing the charge of dust particles the amplitude of solution will increase while their width will decrease. Increasing the nonthermal ions lead to opposite effect.

  15. Electromagnetic phenomena in granular flows in the laboratory and dusty plasmas in geophysics and astrophysics

    Science.gov (United States)

    Lathrop, Daniel; Eiskowitz, Skylar; Rojas, Ruben

    2017-11-01

    In clouds of suspended particles, collisions electrify particles and the clouds produce electric potential differences over large scales. This is seen in the atmosphere as lightning in thunderstorms, thundersnow, dust storms, and volcanic ash plumes, but it is a general phenomena in granular systems. The electrification process is not well understood. To investigate the relative importance of particle material properties and collective phenomena in granular and atmospheric electrification, we used several tabletop experiments that excite particle-laden flows. Various electromagnetic phenomena ensue. Measured electric fields result from capacitive and direct charge transfer to electrodes. These results suggest that while particle properties do matter (as previous investigations have shown), macroscopic electrification of granular flows is somewhat material independent and large-scale collective phenomena play a major role. As well, our results on charge separation and Hall effects suggest a very different view of the dynamics of clouds, planetary rings, and cold accretion disks in proto-planetary systems. We gratefully acknowledge past funding from the Julian Schwinger Foundation as well as the Ph.D. work of Freja Nordsiek.

  16. Measurement of the ion drag force on falling dust particles and its relation to the void formation in complex (dusty) plasmas

    International Nuclear Information System (INIS)

    Zafiu, C.; Melzer, A.; Piel, A.

    2003-01-01

    Experiments on the quantitative determination of the weaker forces (ion drag, thermophoresis, and electric field force) on free-falling dust particles in a rf discharge tube are presented. The strongest force, gravity, is balanced by gas friction and the weaker forces are investigated in the radial (horizontal) plane. Under most discharge conditions, the particles are found to be expelled from the central plasma region. A transition to a situation where the falling particles are focused into the plasma center is observed at low gas pressures using small particles. These investigations allow a quantitative understanding of the mechanism of unwanted dust-free areas (so-called voids) in dusty plasmas under microgravity. Good quantitative agreement with standard models of the ion drag is found

  17. Compressibility effects on a shear flow in strongly coupled dusty plasma. I. A study using computational fluid dynamics

    Science.gov (United States)

    Gupta, Akanksha; Ganesh, Rajaraman

    2018-01-01

    We study compressibility effects on the two-dimensional strongly coupled dusty plasma by means of computational fluid dynamics (CFD) with the Kolmogorov flow as an initial shear flow profile. Nonlinear compressible vortex flow dynamics and other linear and nonlinear properties of such flow in the presence of variable density, pressure, and electrostatic potential are addressed using a generalised compressible hydrodynamic model. The stabilizing effect of compressibility on the unstable shear flows in the presence of strong correlation ( τm>0 ) is presented. Increasing the Mach number relatively reduces the growth-rate of perturbation. On the other hand, strong correlation makes the medium to be more unstable and increases the growth rate. Using an eigen value solver, various linear properties of compressible Kolmogorov flow have been investigated for a range of variable parameters, for example, Mach number, Reynolds number, and viscoelastic coefficient (τm). Compressible Kolmogorov flow becomes unstable above a critical value of the Reynolds number (Rc), and below Rc, the shear flow is found to be neutrally stable. In this study, it is found that the viscoelasticity reduces the value of Rc. For our choice of parameters, at τm=τmc , the compressible Kolmogorov flow becomes unconditionally unstable and no Rc exists for values of τm higher than τmc . To address the nonlinear properties, for example, mode-mode interaction due to the presence of nonlinearity in the fluid, vortex formation, etc., a massively parallelized Advanced Generalized SPECTral Code (AG-Spect) has been developed. AG-Spect, a newly developed code, is an efficient tool to solve any set of nonlinear fluid dynamic equations. A good agreement in linear growth rates obtained from the eigen value solver and time dependent simulation (AG-Spect) is found. In our CFD study, the suppression of instability, elongated vortex structures, pattern formation, nonlinear saturation, and visco

  18. Head-on collision of dust-acoustic solitary waves in an adiabatic hot dusty plasma with external oblique magnetic field and two-temperature ions

    Science.gov (United States)

    El-Labany, S. K.; El-Shamy, E. F.; Sabry, R.; Shokry, M.

    2010-02-01

    In the present paper, the characteristics of the head-on collision between two dust-acoustic solitary waves (DASWs) in an adiabatic dusty plasma consisting of variable negatively charged dust grains, isothermal electrons and two-temperature isothermal ions in the presence of an external oblique magnetic field are investigated. Using the extended Poincaré-Lighthill-Kuo (PLK) method, the Korteweg-de Vries (KdV) equations and the analytical phase shifts after the head-on collision of two solitary waves are derived. The effects of the magnetic field and its obliqueness, two different type of isothermal ions and the dust particles adiabaticity are discussed. It is found that these factors significantly affect the phase shifts.

  19. Measurement of attractive interactions produced by the ion wakefield in dusty plasmas using a constrained collision geometry.

    Science.gov (United States)

    Hebner, G A; Riley, M E

    2003-10-01

    Plasma dust particle interactions, charges, and screening lengths are derived from measurements of time-dependent particle positions in a simplified geometry. The magnitude and structure of the ion wakefield potential below a negatively charged dust particle levitated in the plasma sheath region were measured as functions of the pressure and interparticle spacing. Attractive and repulsive components of the interaction force were extracted from a trajectory analysis of low-energy dust collisions between different mass particles in a well-defined electrostatic potential that constrained the dynamics of the collisions to be one-dimensional. Typical peak attractions varied between 60 and 230 fN while the peak particle-particle repulsion was on the order of 60 fN. Random thermal motion of the particles contributed to observable rates for transitions between different equilibrium configurations of vertically separated particles. The influence of nearest- and non-nearest-neighbor interactions on calculated particle parameters is examined using several methods.

  20. Effect of dust size distribution on ion-acoustic solitons in dusty plasmas with different dust grains

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Dong-Ning; Yang, Yang; Yan, Qiang [Northwest Normal University, College of Physics and Electronic Engineering (China); Wang, Xiao-Yun [Lanzhou Jiao Tong University, Department of Mathematics and Physics (China); Duan, Wen-Shan, E-mail: duanws@126.com [Northwest Normal University, College of Physics and Electronic Engineering (China)

    2017-02-15

    Theoretical studies are carried out for ion acoustic solitons in multicomponent nonuniform plasma considering the dust size distribution. The Korteweg−de Vries equation for ion acoustic solitons is given by using the reductive perturbation technique. Two special dust size distributions are considered. The dependences of the width and amplitude of solitons on dust size parameters are shown. It is found that the properties of a solitary wave depend on the shape of the size distribution function of dust grains.

  1. Oblique propagation of dust ion-acoustic solitary waves in a magnetized dusty pair-ion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Misra, A. P., E-mail: apmisra@visva-bharati.ac.in, E-mail: apmisra@gmail.com; Barman, Arnab [Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan-731 235, West Bengal (India)

    2014-07-15

    We investigate the propagation characteristics of electrostatic waves in a magnetized pair-ion plasma with immobile charged dusts. It is shown that obliquely propagating (OP) low-frequency (in comparison with the negative-ion cyclotron frequency) long-wavelength “slow” and “fast” modes can propagate, respectively, as dust ion-acoustic (DIA) and dust ion-cyclotron (DIC)-like waves. The properties of these modes are studied with the effects of obliqueness of propagation (θ), the static magnetic field, the ratios of the negative to positive ion masses (m), and temperatures (T) as well as the dust to negative-ion number density ratio (δ). Using the standard reductive perturbation technique, we derive a Korteweg-de Vries (KdV) equation which governs the evolution of small-amplitude OP DIA waves. It is found that the KdV equation admits only rarefactive solitons in plasmas with m well below its critical value m{sub c} (≫ 1) which typically depends on T and δ. It is shown that the nonlinear coefficient of the KdV equation vanishes at m = m{sub c}, i.e., for plasmas with much heavier negative ions, and the evolution of the DIA waves is then described by a modified KdV (mKdV) equation. The latter is shown to have only compressive soliton solution. The properties of both the KdV and mKdV solitons are studied with the system parameters as above, and possible applications of our results to laboratory and space plasmas are briefly discussed.

  2. Dust-acoustic solitary waves and double layers in a magnetized dusty plasma with nonthermal ions and dust charge variation

    International Nuclear Information System (INIS)

    El-Taibany, W.F.; Sabry, R.

    2005-01-01

    The effect of nonthermal ions and variable dust charge on small-amplitude nonlinear dust-acoustic (DA) waves is investigated. It is found that both compressive and rarefactive solitons exist and depend on the nonthermal parameter a. Using a reductive perturbation theory, a Zakharov-Kuznetsov (ZK) equation is derived. At critical value of a, a c , a modified ZK equation with third- and fourth-order nonlinearities, is obtained. Depending on a, the solution of the evolution equation reveals whether there is coexistence of both compressive and rarefactive solitary waves or double layers (DLs) with the possibility of their two kinds. In addition, for certain plasma parameters, the solitary wave disappears and a DL is expected. The variation of dust charge number, wave velocity, and soliton amplitude and its width against system parameters is investigated for the DA solitary waves. It is shown that the incorporation of both the adiabatic dust-charge variation and the nonthermal distributed ions modifies significantly the nature of DA solitary waves and DA DLs. The findings of this investigation may be useful in understanding the ion acceleration mechanisms close to the Moon and also enhances our knowledge on pickup ions around unmagnetized bodies, such as comets, Mars, and Venus

  3. Non-locality and memory effects in grain dynamics on a 2D dusty plasma quasi-crystal

    International Nuclear Information System (INIS)

    Ratynskaia, S.; Rypdal, K.; Milovanov, A.; Rasmussen, J. J.; Knapek, C.; Morfill, G.

    2005-01-01

    By tuning RF-power and neutral gas pressure as control parameters in a dust plasma crystal experiment it is possible to obtain a state exhibiting rather high mobility of the dust grains through development of defects, yet maintaining the global hexagonal structure. The state exhibits higher mobility and smaller vertical structures along the rim and larger and more slowly moving and rotating crystalline domains in the core. It is different from the critical transition between the crystalline and liquid state. Trajectories of all particles in a cluster consisting of about 700 dust grains are tracked through 30.000 frames (time-steps). During this time the length of a grain trajectory is typically considerably greater than the linear size of the cluster. Variogram and rescaled range (R/S) analysis of time series of particle positions reveal super-diffusive behavior which, from a stochastic process viewpoint, often is ascribed to either long memory effects or to the presence of non-locality manifested as Levy flights giving rise to heavy algebraic tails in the position increment probability distribution function (PDF). The experimental PDF is non-gaussian, but the tails are not algebraic. The core of the PDF, however, has the shape of a truncated Levy distribution, which is shown to be stretched exponential of width that expands in time in a super-diffusive manner. Thus, super-diffusion could in principle occur without long-range time dependence in the increment time series and without algebraic tails in the PDF. Analysis of the core PDF and PDFs on different level of coarse gaining of the time series, combined with variogram and R/S analysis techniques, are employed to disentangle memory and non-locality effects. The results are discussed and interpreted in the framework of a fractional kinetics approach. (Author)

  4. A longitudinal study of plasma insulin and glucagon in women with previous gestational diabetes

    DEFF Research Database (Denmark)

    Damm, P; Kühl, C; Hornnes, P

    1995-01-01

    OBJECTIVE: To investigate whether plasma insulin or glucagon predicts later development of diabetes in women with gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: The subjects studied were 91 women with diet-treated GDM and 33 healthy women. Plasma insulin and glucagon during a 50...... at follow-up (2 had insulin-dependent diabetes mellitus, 13 had non-insulin-dependent diabetes mellitus, and 12 had impaired glucose tolerance). Compared with the control subjects, women with previous GDM had relatively impaired insulin secretion (decreased insulinogenic index and delayed peak insulin...... for subsequent development of overt diabetes (logistic regression analysis). CONCLUSIONS: Women who develop GDM have a relative insulin secretion deficiency, the severity of which is predictive for later development of diabetes. Furthermore, our data indicate that their relatively reduced beta-cell function may...

  5. Jeans instability with exchange effects in quantum dusty magnetoplasmas

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, M., E-mail: jamil.gcu@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Rasheed, A. [Department of Physics, Government College University, Faisalabad 38000 (Pakistan); Rozina, Ch. [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Jung, Y.-D. [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of); Salimullah, M. [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh)

    2015-08-15

    Jeans instability is examined in magnetized quantum dusty plasmas using the quantum hydrodynamic model. The quantum effects are considered via exchange-correlation potential, recoil effect, and Fermi degenerate pressure, in addition to thermal effects of plasma species. It is found that the electron exchange and correlation potential have significant effects over the threshold value of wave vector and Jeans instability. The presence of electron exchange and correlation effect shortens the time of dust sound that comparatively stabilizes the self gravitational collapse. The results at quantum scale are helpful in understanding the collapse of the self-gravitating dusty plasma systems.

  6. Cylindrical and spherical dust-acoustic wave modulations in dusty ...

    Indian Academy of Sciences (India)

    The nonlinear wave modulation of planar and non-planar (cylindrical and spherical) dust-acoustic waves (DAW) propagating in dusty plasmas, in the presence of non-extensive distributions for ions and electrons is investigated. By employing multiple scales technique, a cylindrically and spherically modified nonlinear ...

  7. Cylindrical and spherical dust-acoustic wave modulations in dusty ...

    Indian Academy of Sciences (India)

    Abstract. The nonlinear wave modulation of planar and non-planar (cylindrical and spherical) dust-acoustic waves (DAW) propagating in dusty plasmas, in the presence of non-extensive distribu- tions for ions and electrons is investigated. By employing multiple scales technique, a cylindrically and spherically modified ...

  8. Cylindrical and spherical dust-acoustic wave modulations in dusty ...

    Indian Academy of Sciences (India)

    Cylindrical and dust-acoustic wave modulations in dusty plasmas. PQ is required for wave amplitude (modulational) stability. On the other hand, a positive sign of PQ allows for a random perturbation to grow and may thus lead to wave collapse or blow-up. To investigate the stability profile, we have determined in various ...

  9. Molecular dynamics of the structure and thermodynamics of dusty ...

    African Journals Online (AJOL)

    The static structure and thermodynamic properties of two-dimensional dusty plasma are analyzed for some typical values of coupling and screening parameters using classical molecular dynamics. Radial distribution function and static structure factor are computed. The radial distribution functions display the typical ...

  10. Dust acoustic solitary and shock waves in strongly coupled dusty ...

    Indian Academy of Sciences (India)

    mal vortex-like ion distribution and strongly correlated grains in a liquid-like state and discussed about the properties of shock ... shock waves in coupled dusty plasma with Boltzmann distribution of ions. Ghosh et al have studied the effect of ... ues of parameters where the nonlinear term is zero. Also new kind of shock wave.

  11. Nonlinear propagation of dust-acoustic solitary waves in a dusty ...

    Indian Academy of Sciences (India)

    component unmag- netized dusty plasma consisting of trapped electrons, Maxwellian ions, and arbitrarily charged cold mobile dust was done. It has been found that, owing to the departure from the Maxwellian elec- tron distribution to a vortex-like ...

  12. Dustiness testing of engineered nanomaterials

    International Nuclear Information System (INIS)

    Ogura, Isamu; Sakurai, Hiromu; Gamo, Masashi

    2009-01-01

    We investigated the dustiness (the propensity of a material to generate airborne dust during its handling) of various nanomaterials, including carbon nanotubes and metal oxides, by the vortex shaker method. The number concentrations and size distributions (∼10->10 000 nm) of aerosol particles released during agitation were measured. It was found that the modal diameter was greater than 100 nm for all tested nanomaterials, and for most of them some sub-100 nm particles were observed. The dustiness differed by two (or three) orders of magnitude among the test nanomaterials.

  13. Plasma LTE4/PGF2α Ratio and Blood Eosinophil Count Are Increased in Elderly Asthmatics With Previous Asthma Exacerbation.

    Science.gov (United States)

    Ban, Ga Young; Ye, Young Min; Kim, Sang Ha; Hur, Gyu Young; Kim, Joo Hee; Shim, Jae Jung; Cho, Kumsun; Cho, Joo Youn; Park, Hae Sim

    2017-07-01

    The tools for asthma control assessment recommended by the current guideline are cognitive function- and effort-dependent, which is substantially impaired in the elderly. The aim of this study is to investigate objective assessment tools of asthma control status and previous asthma exacerbation (AE) in elderly subjects. Asthmatics aged >60 years who were treated with step 2 or 3 by the Global Initiative for Asthma (GINA) guideline were enrolled. During the 12-week study period, the subjects used either 400 μg of budesonide plus 10 mg of montelukast or 800 μg of inhaled budesonide. The occurrence of AE during the 4-week run-in and 12-week treatment period was monitored. After 12-week of treatment, sputum eosinophil count, peripheral eosinophil count, the plasma leukotriene E4 (LTE4), and prostaglandin F2α (PGF2α) metabolite levels were measured using the UHPLC/Q-ToF MS system. The study subjects were divided into group 1 (asthmatics who experienced AE during the study period) and group 2 (those who did not). A total of 101 patients aged 60-85 years were enrolled. Twenty-three patients (22.8%) had experienced AE. The plasma LTE4 level, LTE4/PGF2α ratio, and peripheral eosinophil count were significantly higher in group 1 than in group 2 (P=0.023, P=0.010, P=0.033, respectively). The plasma LTE4/PGF2α ratio and peripheral eosinophil count at week 12 were significantly associated with previous AE (odds ratio [OR]=1.748, P=0.013; OR=1.256, P=0.027). Receiver operating characteristic (ROC) curves to discriminate the subjects with previous AE, including these 2 parameters, showed that the area under the curve was 0.700 (P=0.004), with 73.9% sensitivity and 47.9% specificity. In conclusion, a combination of plasma LTE4/PGF2α ratio and peripheral eosinophil count can be an objective assessment tool which is significantly associated with asthma control status in elderly asthmatics. Copyright © 2017 The Korean Academy of Asthma, Allergy and Clinical Immunology · The

  14. Thermal condensation mode in a dusty plasma

    Indian Academy of Sciences (India)

    Abstract. In the present work, the radiative condensation instability is investigated in the presence of dust charge fluctuations. We find that the charge variability of the grain reduces the growth rate of radiative mode only for fluctuation wavelength smaller or of the order of the Debye length and this reduction is not very large.

  15. Thermal condensation mode in a dusty plasma

    Indian Academy of Sciences (India)

    ... in the presence of dust charge fluctuations. We find that the charge variability of the grain reduces the growth rate of radiative mode only for fluctuation wavelength smaller or of the order of the Debye length and this reduction is not very large. Far from the Debye sphere, radiative mode can damp due to thermal conduction ...

  16. Effects of previous protein intake on rectal temperature, blood glucose, plasma thyroid hormone and minerals by laying hens during a forced molt

    International Nuclear Information System (INIS)

    Rodrigues, G.A.; Moraes, V.M.B.; Cherici, I; Furlan, R.L.; Macari, M.

    1991-01-01

    The effects of forced molting on blood glucose, rectal temperature, plasma T4, T3 and minerals were studied in hens previously fed rations with different protein contents (14, 17 and 20% crude protein). Blood samples were obtained from brachial veins for blood glucose, T4 and T3 were measured by radioimmunoassay, and plasma minerals were determined by atomic absorption spectroscopy. Blood glucose and rectal temperature were reduced during fasting regardless of previous protein intake. Pre molting T4 plasma level was higher in laying hens fed higher protein ration, but feed deprivation reduced T 4 and T 3 concentrations irrespective of protein intake, except T 4 level for 14% crude protein fed birds that increased during fasting. The data obtained in this experiment suggest that previous protein intake does not interfere with the metabolic changes during forced molt. (author). 19 refs, 1 fig, 4 tabs

  17. Mineral magnetism of dusty olivine

    DEFF Research Database (Denmark)

    Lappe, Sophie-Charlotte L. L.; Church, Nathan S.; Kasama, Takeshi

    2011-01-01

    The magnetic properties of olivine-hosted Fe-Ni particles have been studied to assess the potential of "dusty olivine" to retain a pre-accretionary remanence in chondritic meteorites. Both body-centered (bcc) and face-centered cubic (fcc) Fe-Ni phases were formed by reduction of a terrestrial...... olivine precursor. The presence of Ni complicates the magnetic properties during heating and cooling due to the fcc-bcc martensitic transition. First-order reversal curve (FORC) diagrams contain a central ridge with a broad coercivity distribution extending to 600 mT, attributed to non-interacting single...... a credible recorder of pre-accretionary magnetic fields. Copyright 2011 by the American Geophysical Union....

  18. Nonlinear propagation of dust-acoustic solitary waves in a dusty ...

    Indian Academy of Sciences (India)

    ... Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Pramana – Journal of Physics; Volume 80; Issue 6. Nonlinear propagation of dust-acoustic solitary waves in a dusty plasma with arbitrarily charged dust and trapped electrons. O Rahman A A Mamun. Volume 80 Issue 6 June 2013 pp ...

  19. Effect of radiative cooling on a hot charged dusty grains with charging fluctuation

    International Nuclear Information System (INIS)

    ElWakil, S.A.; El-Shewy, E.K.; El-Basyouny, S.T.

    2005-01-01

    The effect of the radiative cooling of electrons on the gravitational collapse of hot dust grains with fluctuating electric charge is investigated. Propagation of linear solitary radiation in an unmagnetized collisionless dusty plasma is studied. The standard normal-mode analysis is used to study the stability condition of linear wave

  20. WISE and the Dusty Universe

    Science.gov (United States)

    Benford, Dominic J.

    2010-01-01

    The Wide-field Infrared Survey is a medium class Explorer mission that was launched onl4Dec 2009. WISE should detect hundreds of millions of stars and galaxies, including millions of ULIRGS and QSOs; hundreds of thousands of asteroids; and hundreds of cold brown dwarfs. The telescope cover was ejected on 29 Dec 2009 and the all-sky survey started on 14 Jan 2010. WISE takes more the 7000 framesets per day, with each frameset covering 0.6 square degrees in four bands centered at 3.4, 4.6, 12 and 22 microns. WISE is well-suited to the discovery of brown dwarfs, ultraluminous infrared galaxies, and near-Earth objects. With an angular resolution of 6 arcsecouds at 12 microns, a 5(sigma) point-source sensitivity of around 1 mJy at 12 microns and 6 mJy at 22 microns, and coverage of over 99% of the sky, WISE also provides a powerful database for the study of the dusty ISM in our own galaxy. A preliminary release of WISE data will be made available to the community 6 months after the end of the cryogenic survey, or about May 2011. The final data release will be 11 months later, about April 2012.

  1. Vitamin C in plasma is inversely related to blood pressure and change in blood pressure during the previous year in young Black and White women

    Directory of Open Access Journals (Sweden)

    Hudes Mark

    2008-12-01

    Full Text Available Abstract Background The prevalence of hypertension and its contribution to cardiovascular disease risk makes it imperative to identify factors that may help prevent this disorder. Extensive biological and biochemical data suggest that plasma ascorbic acid may be such a factor. In this study we examined the association between plasma ascorbic acid concentration and blood pressure (BP in young-adult women. Methods Participants were 242 Black and White women aged 18–21 yr from the Richmond, CA, cohort of the National Heart, Lung and Blood Institute Growth and Health Study. We examined the associations of plasma ascorbic acid with BP at follow-up year 10, and with change in BP during the previous year. Results In cross-sectional analysis, plasma ascorbic acid at year 10 was inversely associated with systolic BP and diastolic BP after adjusting for race, body mass index, education, and dietary intake of fat and sodium. Persons in the highest one-fourth of the plasma ascorbic acid distribution had 4.66 mmHg lower systolic BP (95% CI 1.10 to 8.22 mmHg, p = 0.005 and 6.04 mmHg lower diastolic BP (95% CI 2.70 to 9.38 mmHg, p = 0.0002 than those in the lowest one-fourth of the distribution. In analysis of the change in BP, plasma ascorbic acid was also inversely associated with change in systolic BP and diastolic BP during the previous year. While diastolic blood pressure among persons in the lowest quartile of plasma ascorbic acid increased by 5.97 mmHg (95% CI 3.82 to 8.13 mmHg from year 9 to year 10, those in the highest quartile of plasma vitamin C increased by only 0.23 mmHg (95% CI -1.90 to +2.36 mmHg (test for linear trend: p Conclusion Plasma ascorbic acid was found to be inversely associated with BP and change in BP during the prior year. The findings suggest the possibility that vitamin C may influence BP in healthy young adults. Since lower BP in young adulthood may lead to lower BP and decreased incidence of age-associated vascular events in

  2. An Exploration of Dusty Galaxies

    Science.gov (United States)

    Kohler, Susanna

    2017-04-01

    Submillimeter galaxies i.e., galaxies that we detect in the submillimeter wavelength range are mysterious creatures. Its only within the last couple decades that weve had telescope technology capable of observing them, and were only now getting to the point where angular resolution limits allow us to examine them closely. A new study has taken advantage of new capabilities to explore the properties of a sample of 52 of thesegalaxies.Dusty Star FormationSubmillimeter galaxies are generally observed in the early universe. Though theyre faint in other wavebands, theyre extremely luminous in infrared and submillimeter their infrared luminosities are typically trillions of times the Suns luminosity. This is thought to be because these galaxies are very actively forming stars at rates of hundreds of times that of the Milky Way!Example 10 10 true-color images of ten submillimeter galaxies in the authors ALMA-identified sample. [Simpson et al. 2017]Submillimeter galaxies are also extremely dusty, so we dont see their star formation directly in optical wavelengths. Instead, we see the stellar light after its been absorbed and reemitted by interstellar dust lanes were indirectly observing heavily obscured star formation.Why look for submillimeter galaxies? Studying them can help us to learn about galaxy and star formation early in our universes history, and help us to understand how the universe has evolved into what we see locally today.Submillimeter StrugglesDue to angular resolution limitations in the past, we often couldnt pin down the exact locations of submillimeter galaxies, preventing us from examining them properly. But now a team of scientists has used the Atacama Large Millimeter/submillimeter array (ALMA) to precisely locate 52 submillimeter galaxies identified by the Submillimeter Common-User Bolometer Array (SCUBA-2) in the UKIDSS Ultra Deep Survey field.The precise locations made possible by ALMA allowed the team led by James Simpson (University of Edinburgh

  3. Size selective dustiness and exposure; simulated workplace comparisons

    NARCIS (Netherlands)

    Brouwer, D.H.; Links, I.H.M.; Vreede, S.A.F. de; Christopher, Y.

    2006-01-01

    A simulated workplace study was conducted to investigate the relation between inhalation exposure and dustiness determined with a rotating drum dustiness tester. Three powders were used in the study, i.e. magnesium stearate, representing a very dusty powder, and aluminium oxide and calcium

  4. Imposed, ordered dust structures and other plasma features in a strongly magnetized plasma

    Science.gov (United States)

    Thomas, Edward; Leblanc, Spencer; Lynch, Brian; Konopka, Uwe; Merlino, Robert; Rosenberg, Marlene

    2015-11-01

    The Magnetized Dusty Plasma Experiment (MDPX) device has been in operation for just over one year. In that time, the MDPX device has been operating using a uniform magnetic field configuration up to 3.0 Tesla and has successfully produced plasmas and dusty plasmas at high magnetic fields. In these experimental studies, we have made observations of a new type of imposed, ordered structure in a dusty plasma at magnetic fields above 1 T. These dusty plasma structures are shown to scale inversely with neutral pressure and are shown to reflect the spatial structure of a wire mesh placed in the plasma. Additionally, recent measurements have been made that give insights into the effective potential that establishes the ordered structures in the plasma. In this presentation, we report on details of the imposed, ordered dusty plasma structure as well as filamentary features that also appear in the plasma and modify the confinement of the dusty plasma. This work is supported with funding from the NSF and Department of Energy.

  5. Particle size distribution: A key factor in estimating powder dustiness.

    Science.gov (United States)

    López Lilao, Ana; Sanfélix Forner, Vicenta; Mallol Gasch, Gustavo; Monfort Gimeno, Eliseo

    2017-12-01

    A wide variety of raw materials, involving more than 20 samples of quartzes, feldspars, nephelines, carbonates, dolomites, sands, zircons, and alumina, were selected and characterised. Dustiness, i.e., a materials' tendency to generate dust on handling, was determined using the continuous drop method. These raw materials were selected to encompass a wide range of particle sizes (1.6-294 µm) and true densities (2650-4680 kg/m 3 ). The dustiness of the raw materials, i.e., their tendency to generate dust on handling, was determined using the continuous drop method. The influence of some key material parameters (particle size distribution, flowability, and specific surface area) on dustiness was assessed. In this regard, dustiness was found to be significantly affected by particle size distribution. Data analysis enabled development of a model for predicting the dustiness of the studied materials, assuming that dustiness depended on the particle fraction susceptible to emission and on the bulk material's susceptibility to release these particles. On the one hand, the developed model allows the dustiness mechanisms to be better understood. In this regard, it may be noted that relative emission increased with mean particle size. However, this did not necessarily imply that dustiness did, because dustiness also depended on the fraction of particles susceptible to be emitted. On the other hand, the developed model enables dustiness to be estimated using just the particle size distribution data. The quality of the fits was quite good and the fact that only particle size distribution data are needed facilitates industrial application, since these data are usually known by raw materials managers, thus making additional tests unnecessary. This model may therefore be deemed a key tool in drawing up efficient preventive and/or corrective measures to reduce dust emissions during bulk powder processing, both inside and outside industrial facilities. It is recommended, however

  6. Quantum ion-acoustic solitary waves in weak relativistic plasma

    Indian Academy of Sciences (India)

    ion-acoustic waves. Recently, Stenflo et al [24] observed two new low-frequency elec- trostatic modes in ultra-cold unmagnetized quantum dusty plasmas. Ali and Shukla ... waves in a nonuniform ultra-cold Fermi dusty gas composed of inertialess electrons, and ions as well ... the Van Allen radiation belts [34] etc. Streaming ...

  7. Exposure assessment of four pharmaceutical powders based on dustiness and evaluation of damaged HEPA filters.

    Science.gov (United States)

    Levin, Marcus; Koponen, Ismo K; Jensen, Keld A

    2014-01-01

    In this study, we show the different dustiness characteristics of four molecular pharmaceutical powder candidates and evaluate the performance of HEPA filters damaged with three different pinhole sizes and exposed to dust using real industrial powders in a miniaturized EN15051 rotating drum dustiness tester. We then demonstrate the potential use of such data using first-order exposure modeling to assess the potential worker exposure and transmission of active powder ingredients into ventilation systems. The four powders had highly variable inhalable dustiness indices (1,036 - 14,501 mg/kg). Dust particle size-distributions were characterized by three peaks; the first occurred around 60-80 nm, the second around 250 nm, and the third at 2-3 μm. The second and third peaks are often observed in dustiness test studies, but peaks in the 60-80 nm range have not been previously reported. Exposure modeling in a 5 times 20 kg powder pouring scenario, suggests that excessive dust concentrations may be reached during use of powders with the highest dustiness levels. By number, filter-damage by three pinhole sizes resulted in damage-dependent penetration of 70-80 nm-size particles, but by volume and mass the penetration is still dominated by particles larger than 100 nm. Whereas the exposure potential was evident, the potential dust concentrations in air ducts following the pouring scenario above were at pg/m(3) levels. Hence, filter penetration at these damage levels was assumed to be only critical, if the active ingredients were associated with high hazard or unique product purity is required. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: An example of a typical particle number time-series of a complete dustiness test. It provides information on the HEPA-filter used including a scanning electron microscopy image of it. It also

  8. The Dusty Disc of NGC 247

    Science.gov (United States)

    2011-03-01

    This image of NGC 247, taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile, reveals the fine details of this highly inclined spiral galaxy and its rich backdrop. Astronomers say this highly tilted orientation, when viewed from Earth, explains why the distance to this prominent galaxy was previously overestimated. The spiral galaxy NGC 247 is one of the closest spiral galaxies of the southern sky. In this new view from the Wide Field Imager on the MPG/ESO 2.2-metre telescope in Chile large numbers of the galaxy's component stars are clearly resolved and many glowing pink clouds of hydrogen, marking regions of active star formation, can be made out in the loose and ragged spiral arms. NGC 247 is part of the Sculptor Group, a collection of galaxies associated with the Sculptor Galaxy (NGC 253, also shown in eso0902 and eso1025). This is the nearest group of galaxies to our Local Group, which includes the Milky Way, but putting a precise value on such celestial distances is inherently difficult. To measure the distance from the Earth to a nearby galaxy, astronomers have to rely on a type of variable star called a Cepheid to act as a distance marker. Cepheids are very luminous stars, whose brightness varies at regular intervals. The time taken for the star to brighten and fade can be plugged into a simple mathematical relation that gives its intrinsic brightness. When compared with the measured brightness this gives the distance. However, this method isn't foolproof, as astronomers think this period-luminosity relationship depends on the composition of the Cepheid. Another problem arises from the fact that some of the light from a Cepheid may be absorbed by dust en route to Earth, making it appear fainter, and therefore further away than it really is. This is a particular problem for NGC 247 with its highly inclined orientation, as the line of sight to the Cepheids passes through the galaxy's dusty disc. However, a

  9. Investigations on isotopic composition of dusty mist of southern Tajikistan

    International Nuclear Information System (INIS)

    Abdullaev, S.F.; Abdurasulova, N.A.; Maslov, V.A.; Madvaliev, U.; Juraev, A.A.; Davlatshoev, T. S.U.

    2012-01-01

    Atmosphere physics laboratory under S.U. Umarov Physical and Technical Institute Academy of Sciences of the Republic of Tajikistan have carried out investigations on optical and micro physical properties of arid zone aerosols from 1982. Traces of man-made radioactive isotopes were revealed in sands and dust compositions taken in arid zone of Tajikistan during Soviet-American tests on investigation of arid aerosol. Produced result was the basis for further investigation of element composition for dusty haze distributed from south till central part of the country. We investigated samples of soil collected by natural sedimentation along dusty haze distribution and samples of dusty aerosol (in total 80 samples).

  10. Wake potential in a nonuniform self-gravitating dusty magnetoplasma in the presence of ion streaming

    International Nuclear Information System (INIS)

    Salimullah, M.; Ehsan, Z.; Zubia, K.; Shah, H. A.; Murtaza, G.

    2007-01-01

    A detailed investigation of the electrostatic asymmetric shielding potential and consequent generation of the dynamical oscillatory wake potential has been examined analytically in an inhomogeneous self-gravitating dusty magnetoplasma in the presence of uniform ion streaming. It is found that the wake potential depends significantly on the test particle speed, ambient magnetic field, ion streaming velocity, and the plasma inhomogeneity. The periodic oscillatory potential might lead to an alternative approach to the Jeans instability for the formation of dust agglomeration leading to gravitational collapse of the self-gravitating systems

  11. Nonlinear propagation of dust-acoustic solitary waves in a dusty ...

    Indian Academy of Sciences (India)

    Dust-acoustic solitary waves in a dusty plasma. Now, using eqs (13)–(15) one can easily eliminate (∂n(2) d /∂ξ), (∂u(2) d /∂ξ), and. (∂φ(2)/∂ξ), and obtain. ∂φ(1). ∂τ. + A. √ φ(1). ∂φ(1). ∂ξ. + B. ∂3φ(1). ∂ξ3. = 0,. (16) where. A = 3γ. 4 vp. (μe + αμi). ,. (17). B = vp. 2(μe + αμi) . (18). Equation (16) is a mKdV equation for ...

  12. Kadomstev–Petviashvili (KP) equation in warm dusty plasma with ...

    Indian Academy of Sciences (India)

    [18] M M Lin and W S Duan, Chaos, Solitons & Fractals 23, 929 (2005). [19] T S Gill, N S Saini and H Kaur, Chaos, Solitons & Fractals 28, 1106 (2006). [20] R A Cairns, A A Mamum, R Bingham, R Boström, R O Dendy, C M C Nairn and. P K Shukla, Geophys. Res. Lett. 22, 2709 (1995). [21] P O Dovner, A I Eriksson, R Bostrm ...

  13. Three-dimensional wake potential in a streaming dusty plasma

    Indian Academy of Sciences (India)

    frequency and low-phase-velocity dust-acoustic mode is the origin of the periodic attractive force between the like polarity particulates along and perpendicular to the streaming ions and dust grains resulting into dust-Coulomb crystal formation.

  14. Three-dimensional wake potential in a streaming dusty plasma

    Indian Academy of Sciences (India)

    Author Affiliations. M Salahuddin1 M K Islam1 A K Banerjee1 M Salimullah1 S K Ghosh1 2. Department of Physics, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; School of Studies in Physics, Vikram University, Ujjain 456 010, India ...

  15. Three-dimensional wake potential in a streaming dusty plasma

    Indian Academy of Sciences (India)

    Department of Physics, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh. £School of Studies in Physics, Vikram University, Ujjain 456 010, India. MS received 27 December 2001; accepted 5 March 2003. Abstract. The oscillatory wake potential for a slowly moving or static test dust particulate in a finite temperature ...

  16. Streaming instability in a velocity–sheared dusty plasma | Duwa ...

    African Journals Online (AJOL)

    In both cases, the growth rate is reduced due to the presence of the dust particles and the velocity shear scale length, LE, is on the order of k-1 (where k is wave vector) for the most unstable mode. An example is given from the plume. Journal of the Nigerian Association of Mathematical Physics Vol. 10 2006: pp. 601-606.

  17. Outcomes following detection of low level plasma HIV RNA in HIV-infected patients previously virologically suppressed on antiretroviral therapy: a retrospective observational study.

    Science.gov (United States)

    Warren, Annabelle M; Cheng, Allen C; Watson, Kerrie; Lewin, Sharon R; Hoy, Jennifer F

    2017-06-01

    Progressively sensitive assays for plasma HIV RNA have led to increased detection of plasma HIV RNA between 20 and 200 copies/ml, known as low level viremia (LLV) when recurrent or persistent, in HIV-infected patients on antiretroviral therapy (ART). The aim of this study was to determine outcomes following initial detection of LLV in an Australian cohort. A retrospective study using the HIV Service Database (Alfred Hospital) included all patients on ART who recorded plasma HIV RNA 20-200 copies/mL following prior virological suppression (viral load (VL) HIV RNA 200 copies/mL. Factors associated with LLV included co-morbid type 2 diabetes, shorter prior virological suppression and lower nadir CD4 cell count. Clinician management of VL 20-200 copies/mL was generally conservative, with infrequent requests for genotypic analysis (3.3% cases) or change in ART (<1% cases). LLV following virological suppression is common, and occurred as an isolated viral blip in half the patients. Those patients with persistent or recurrent LLV had higher rates of type 2 diabetes, shorter prior virological suppression and lower nadir CD4 cell count.

  18. Effect of the raw materials processing on their dustiness

    International Nuclear Information System (INIS)

    López Lilaoa, A.; Juárezb, M.; Sanfelix Fornera, V.; Mallol Gascha, G.; Monfort Gimeno, E.

    2017-01-01

    During the handling and/or processing of powdered materials in the CERAMICS INDUSTRY, one of the most important risks regarding the environmental and occupational health is the potential generation of dust. In this regard, a parameter of great interest is the dustiness of the processed materials; this parameter quantifies the tendency of the powdered materials to generate dust when handled. In this study, to determine the dustiness of a ceramic raw material composition (mixture of the body raw materials), the continuous drop method has been used. This test apparatus was selected because it is considered to better simulate how ceramic materials are handled in the CERAMICS INDUSTRY. The obtained results show that the dustiness of the same ceramic composition exhibits significant changes during the manufacturing process, depending on the presentation form. In this regard, the dry milling sample presents the highest dustiness, which can be significantly reduced (>75%) applying the the moisturization and agglomeration. The obtained results also shown that the best presentation form, regarding the minimization of the dust generation, is achieved in the spray-drying process, where the dustiness is reduced by 95%. [es

  19. General principles for the formation of dust self-organizing structures. Dust collective attraction and plasma crystal formation

    International Nuclear Information System (INIS)

    Tsytovich, V.N.

    2005-01-01

    It is demonstrated that a homogeneous dusty plasma is universally unstable to form structures. The effect of collective grain attraction is a basic phenomenon for the proposed new paradigm (general principles) for the plasma crystal formation

  20. Physics of Plasmas

    CERN Document Server

    Woods, Leslie Colin

    2003-01-01

    A short, self-sufficient introduction to the physics of plasma for beginners as well as researchers in a number of fields. The author looks at the dynamics and stability of magnetoplasma and discusses wave and transport in this medium. He also looks at such applications as fusion research using magnetic confinement of Deuterium plasma, solar physics with its plasma loops reaching high into the corona, sunspots and solar wind, engineering applications to metallurgy, MHD direct generation of electricity, and railguns, finally touching on the relatively new and difficult subject of dusty plasmas.

  1. Sub-arcsecond dusty environment of Eta Carinae

    NARCIS (Netherlands)

    Chesneau, O.; Min, M.; et al., [Unknown; Comber, F.; Barret, D.; Contini, F.; Meynadier, F.; Pagini, L.

    2004-01-01

    The core of the nebula surrounding Eta Carinae has been observed with the VLT Adaptive Optics system NACO and with the interferometer VLTI/MIDI. Narrow-band images at 3.74 and 4.05 micron reveal the butterfly shaped dusty environment with an unprecedented spatial resolution. A void region around the

  2. Dusty Relic to Shining Treasure: Embedded in a Multicultural Environment

    Science.gov (United States)

    Avery, Beth Fuseler; Batman, Cindy

    2014-01-01

    Far from being dusty old relics who are guardians of the book, embedded librarians need to be proactively leading students through the digital maze of the virtual library. Working with students more than 7,000 miles away changed perceptions of how to teach and learn, and how people interact online. We will share how as embedded librarians we…

  3. Dustiness of 14 carbon nanotubes using the vortex shaker method

    Science.gov (United States)

    Dazon, Claire; Witschger, Olivier; Bau, Sébastien; Payet, Raphaël; Beugnon, Karine; Petit, Geneviève; Garin, Thibaut; Martinon, Laurent

    2017-06-01

    The handling of carbon nanotube (CNT) powders is a plausible scenario during the course of the CNT life-cycle. However, related exposure data remain limited. In this context, information about the dustiness of CNT is therefore of great interest, for example for control banding or exposure modelling. Here, we investigate the dustiness of fourteen CNT powders using the Vortex Shaker (VS) method. The central component of the VS method is a stainless steel cylindrical tube, continuously shaken in a circular orbital motion, in which a small volume (0.5 cm3) of the powder to be tested is placed. All samples were obtained through the NANoREG Nanomaterials Information and Web-Order system. The test procedure that we have developed is based on four principal components: (i) a respirable cyclone for gravimetric sampling, (ii) a CPC as a reference instrument for number concentration measurement, (iii) an MPS for collection of particles for EM observations/analysis, and (iv) an ELPI for size-resolved aerosol measurement. In this paper, the data were evaluated using two parameters: (i) the mass-based dustiness index in the respirable fraction; and (ii) the number-based dustiness index in the respirable fraction. The results indicate that the method leads to relatively accurate mass- and number-based dustiness indices. The indices obtained span wide ranges, of 2 and 3 orders of magnitude variation for mass and number respectively, suggesting a corresponding significant difference in terms of potential exposure. EM observations reveal that airborne CNTs are mostly released as bundles of different shapes ranging from a few tens of nanometers up to tens of micrometers in size.

  4. Electrostatic structures associated with dusty electronegative magnetoplasmas

    Science.gov (United States)

    Moslem, W. M.; Abdelsalam, U. M.; Sabry, R.; Shukla, P. K.

    2010-07-01

    By using the hydrodynamic equations of positive and negative ions, the Boltzmann electron density distribution and the Poisson equation with stationary dust, a three-dimensional (3D) Zakharov-Kuznetsov (ZK) equation is derived for small but finite amplitude ion-acoustic waves. However, the ZK equation is not appropriate to describe the system either at critical plasma compositions or in the vicinity of the critical plasma compositions. Therefore, the modified ZK (MZK) and extended ZK (EZK) equations are derived. The generalized expansion method is used to analytically solve the ZK, MZK and EZK equations. A new class of solutions that admits a train of well-separated bell-shaped periodic pulses is obtained. In certain conditions, the latter degenerates to either solitary or shock wave solutions. The effects of the physical parameters on the nonlinear structures are examined in many plasma environments having different negative ion species, such as D- and F-regions of the Earth's ionosphere, as well as in laboratory plasma experiments. Numerical analysis of the solutions revealed that the profile of the nonlinear pulses suffers amplitude and width modifications due to enhancement of the dust practices, negative ions, positive-to-negative ion mass ratio and positive/negative ion cyclotron frequency. Furthermore, the necessary conditions for both solitons and shocks propagation as well as their polarity are examined.

  5. Electrostatic structures associated with dusty electronegative magnetoplasmas

    International Nuclear Information System (INIS)

    Moslem, W M; Abdelsalam, U M; Sabry, R; Shukla, P K

    2010-01-01

    By using the hydrodynamic equations of positive and negative ions, the Boltzmann electron density distribution and the Poisson equation with stationary dust, a three-dimensional (3D) Zakharov-Kuznetsov (ZK) equation is derived for small but finite amplitude ion-acoustic waves. However, the ZK equation is not appropriate to describe the system either at critical plasma compositions or in the vicinity of the critical plasma compositions. Therefore, the modified ZK (MZK) and extended ZK (EZK) equations are derived. The generalized expansion method is used to analytically solve the ZK, MZK and EZK equations. A new class of solutions that admits a train of well-separated bell-shaped periodic pulses is obtained. In certain conditions, the latter degenerates to either solitary or shock wave solutions. The effects of the physical parameters on the nonlinear structures are examined in many plasma environments having different negative ion species, such as D- and F-regions of the Earth's ionosphere, as well as in laboratory plasma experiments. Numerical analysis of the solutions revealed that the profile of the nonlinear pulses suffers amplitude and width modifications due to enhancement of the dust practices, negative ions, positive-to-negative ion mass ratio and positive/negative ion cyclotron frequency. Furthermore, the necessary conditions for both solitons and shocks propagation as well as their polarity are examined.

  6. Electrostatic structures associated with dusty electronegative magnetoplasmas

    Energy Technology Data Exchange (ETDEWEB)

    Moslem, W M [Department of Physics, Faculty of Science, Port Said University (Egypt); Abdelsalam, U M [Department of Mathematics, Faculty of Science, Fayoum University (Egypt); Sabry, R [Theoretical Physics Group, Department of Physics, Faculty of Science, Mansoura University, Damietta Branch, New Damietta 34517 (Egypt); Shukla, P K, E-mail: wmmoslem@hotmail.co, E-mail: wmm@tp4.rub.d, E-mail: maths_us@hotmail.co, E-mail: sabryphys@yahoo.co, E-mail: sabry@tp4.rub.d, E-mail: ps@tp4.rub.d [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

    2010-07-15

    By using the hydrodynamic equations of positive and negative ions, the Boltzmann electron density distribution and the Poisson equation with stationary dust, a three-dimensional (3D) Zakharov-Kuznetsov (ZK) equation is derived for small but finite amplitude ion-acoustic waves. However, the ZK equation is not appropriate to describe the system either at critical plasma compositions or in the vicinity of the critical plasma compositions. Therefore, the modified ZK (MZK) and extended ZK (EZK) equations are derived. The generalized expansion method is used to analytically solve the ZK, MZK and EZK equations. A new class of solutions that admits a train of well-separated bell-shaped periodic pulses is obtained. In certain conditions, the latter degenerates to either solitary or shock wave solutions. The effects of the physical parameters on the nonlinear structures are examined in many plasma environments having different negative ion species, such as D- and F-regions of the Earth's ionosphere, as well as in laboratory plasma experiments. Numerical analysis of the solutions revealed that the profile of the nonlinear pulses suffers amplitude and width modifications due to enhancement of the dust practices, negative ions, positive-to-negative ion mass ratio and positive/negative ion cyclotron frequency. Furthermore, the necessary conditions for both solitons and shocks propagation as well as their polarity are examined.

  7. Plasma Physics An Introduction to Laboratory, Space, and Fusion Plasmas

    CERN Document Server

    Piel, Alexander

    2010-01-01

    Plasma Physics gives a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The new fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a brief introduction to plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple and emphasizes the underlying concepts. T...

  8. Electromagnetic dust-lower-hybrid and dust-magnetosonic waves and their instabilities in a dusty magnetoplasma

    International Nuclear Information System (INIS)

    Salimullah, M.; Rahman, M. M.; Zeba, I.; Shah, H. A.; Murtaza, G.; Shukla, P. K.

    2006-01-01

    The electromagnetic waves below the ion-cyclotron frequency have been examined in a collisionless and homogeneous dusty plasma in the presence of a dust beam parallel to the direction of the external magnetic field. The low-frequency mixed electromagnetic dust-lower-hybrid and purely transverse magnetosonic waves become unstable for the sheared flow of dust grains and grow in amplitude when the drift velocity of the dust grains exceeds the parallel phase velocity of the waves. The growth rate depends dominantly upon the thermal velocity and density of the electrons

  9. Dusty starburst galaxies in the early Universe as revealed by gravitational lensing.

    Science.gov (United States)

    Vieira, J D; Marrone, D P; Chapman, S C; De Breuck, C; Hezaveh, Y D; Weiβ, A; Aguirre, J E; Aird, K A; Aravena, M; Ashby, M L N; Bayliss, M; Benson, B A; Biggs, A D; Bleem, L E; Bock, J J; Bothwell, M; Bradford, C M; Brodwin, M; Carlstrom, J E; Chang, C L; Crawford, T M; Crites, A T; de Haan, T; Dobbs, M A; Fomalont, E B; Fassnacht, C D; George, E M; Gladders, M D; Gonzalez, A H; Greve, T R; Gullberg, B; Halverson, N W; High, F W; Holder, G P; Holzapfel, W L; Hoover, S; Hrubes, J D; Hunter, T R; Keisler, R; Lee, A T; Leitch, E M; Lueker, M; Luong-Van, D; Malkan, M; McIntyre, V; McMahon, J J; Mehl, J; Menten, K M; Meyer, S S; Mocanu, L M; Murphy, E J; Natoli, T; Padin, S; Plagge, T; Reichardt, C L; Rest, A; Ruel, J; Ruhl, J E; Sharon, K; Schaffer, K K; Shaw, L; Shirokoff, E; Spilker, J S; Stalder, B; Staniszewski, Z; Stark, A A; Story, K; Vanderlinde, K; Welikala, N; Williamson, R

    2013-03-21

    In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

  10. Plasma Control for Next-Stage Plasma Processing

    International Nuclear Information System (INIS)

    Sato, N.; Iizuka, S.

    2000-01-01

    A short review is presented of our experiments on plasma controls for next-stage material and device manufacturing, which are concerned with uniform large-diameter plasma production, electron-temperature control, and dust-particle behaviors. We can provide uniform high-density ECR and rf plasmas, the diameters of which are larger than several ten centimeters. The electron temperature is controlled in the range of one or two orders of magnitude in a region separated from a discharge region. Basing on investigations of dust-particle behaviors in low-pressure discharge plasmas, we can now establish a simple method of dust-particle removal from dusty plasmas. (author)

  11. Plasma physics an introduction to laboratory, space, and fusion plasmas

    CERN Document Server

    Piel, Alexander

    2017-01-01

    The enlarged new edition of this textbook provides a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The novel fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a concise description of modern plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple a...

  12. AN INFRARED CENSUS OF DUST IN NEARBY GALAXIES WITH SPITZER (DUSTiNGS). II. DISCOVERY OF METAL-POOR DUSTY AGB STARS

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Martha L.; Sonneborn, George [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McQuinn, Kristen B. W.; Gehrz, Robert D.; Skillman, Evan [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street SE, University of Minnesota, Minneapolis, MN 55455 (United States); Barmby, Pauline [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Bonanos, Alceste Z. [IAASARS, National Observatory of Athens, GR-15236 Penteli (Greece); Gordon, Karl D.; Meixner, Margaret [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Groenewegen, M. A. T. [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels (Belgium); Lagadec, Eric [Laboratoire Lagrange, UMR7293, Univ. Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d' Azur, F-06300 Nice (France); Lennon, Daniel [ESA-European Space Astronomy Centre, Apdo. de Correo 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Marengo, Massimo [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); McDonald, Iain; Zijlstra, Albert [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Sloan, G. C. [Astronomy Department, Cornell University, Ithaca, NY 14853-6801 (United States); Van Loon, Jacco Th., E-mail: martha.boyer@nasa.gov [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom)

    2015-02-10

    The DUSTiNGS survey (DUST in Nearby Galaxies with Spitzer) is a 3.6 and 4.5 μm imaging survey of 50 nearby dwarf galaxies designed to identify dust-producing asymptotic giant branch (AGB) stars and massive stars. Using two epochs, spaced approximately six months apart, we identify a total of 526 dusty variable AGB stars (sometimes called ''extreme'' or x-AGB stars; [3.6]-[4.5] > 0.1 mag). Of these, 111 are in galaxies with [Fe/H] < –1.5 and 12 are in galaxies with [Fe/H] < –2.0, making them the most metal-poor dust-producing AGB stars known. We compare these identifications to those in the literature and find that most are newly discovered large-amplitude variables, with the exception of ≈30 stars in NGC 185 and NGC 147, 1 star in IC 1613, and 1 star in Phoenix. The chemical abundances of the x-AGB variables are unknown, but the low metallicities suggest that they are more likely to be carbon-rich than oxygen-rich and comparisons with existing optical and near-IR photometry confirm that 70 of the x-AGB variables are confirmed or likely carbon stars. We see an increase in the pulsation amplitude with increased dust production, supporting previous studies suggesting that dust production and pulsation are linked. We find no strong evidence linking dust production with metallicity, indicating that dust can form in very metal-poor environments.

  13. Pseudopotentials of the particles interactions in complex plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, T. S.; Moldabekov, Zh. A.; Dzhumagulova, K. N.; Muratov, M. M. [Al Farabi Kazakh National University, IETP, Tole bi 96a, Almaty 050012 (Kazakhstan)

    2011-10-15

    This article discusses the effective interaction potentials in a complex dusty plasma. The interaction of electrons with atoms and the interaction between dusty particles are studied by the method of the dielectric response function. In the effective interaction, potential between electron and atom the quantum effects of diffraction were taken into account. On the curve of the interaction potential between dust particles under certain conditions the oscillations can be observed.

  14. Population Synthesis Models for Normal Galaxies with Dusty Disks

    Directory of Open Access Journals (Sweden)

    Kyung-Won Suh

    2003-09-01

    Full Text Available To investigate the SEDs of galaxies considering the dust extinction processes in the galactic disks, we present the population synthesis models for normal galaxies with dusty disks. We use PEGASE (Fioc & Rocca-Volmerange 1997 to model them with standard input parameters for stars and new dust parameters. We find that the model results are strongly dependent on the dust parameters as well as other parameters (e.g. star formation history. We compare the model results with the observations and discuss about the possible explanations. We find that the dust opacity functions derived from studies of asymptotic giant branch stars are useful for modeling a galaxy with a dusty disk.

  15. The Dusty Dynamics Within a Regional Mars Dust Storm

    Science.gov (United States)

    Rafkin, Scot C. R.; Pla-Garcia, Jorge; Leung, Cecilia

    2017-10-01

    There have never been in situ observations at or near the active lifting center of a regional dust storm on Mars. In the absence of in situ data, it is common to employ numerical models to provide guidance on the physical processes and conditions operating in an unobserved location or weather system. Consequently, the Mars Regional Atmospheric Modeling System (MRAMS) is employed to study the structure and dynamics of a simulated large regional storm using a fully interactive dust cycle. The simulations provide the first ever glimpse of the conditions that might occur inside one of these storms.The simulated storm shows extremely complex structure with narrow lifting centers and a variety of deep dust transport circulations. The active lifting centers are broadly into a mesoscale system in much the same way that thunderstorms on Earth can organize into mesoscale convective structures. In many of the active dusty plumes, the mixing ratio of dust peaks near the surface and drops off with height. Once lifted, the largest dust tends to sediment out while the smaller dust continues to be advected upward by the plume. This size-sorting process combined with entrainment of less dusty air tends to drive the mixing ratio profile to a maximum near the surface. In dusty plumes near the surface, the air temperature is as much as 20K colder than nearby areas. This is due to solar absorption higher in the dust column limiting direct heating deeper into the atmosphere. Overall, within the plume, there is an inversion, and although the top of the plume is warmer than below, it is near neutral buoyancy compared to the less dusty air on either side. Apparently, adiabatic cooling nearly offsets the expected positive heating perturbation at the top of the dusty plume. A very strong low level just forms in the vicinity of the storm, accompanied by system-wide negative pressure deficits and circulation patterns strongly suggestive of the wind-enhanced interaction of radiation and dust

  16. Dustiness of chopped straw as affected by lignosulfonate as a dust suppressant.

    Science.gov (United States)

    Breum, N O; Nielsen, B H; Lyngbye, M; Midtgård, U

    1999-01-01

    Many sources add to the concentration of bioaerosols in livestock buildings, and source control is the number one priority for keeping a low concentration. Straw is a common but dusty bedding material in livestock buildings and the present study is focused on the dustiness of chopped straw (barley) as affected by lignosulfonate (LS) as a dust suppressant. A LS-solution was aerosolized in a spray chamber fitted to an existing bedding chopper to allow the chopped straw to adsorb the LS-solution. The dustiness of straw treated with LS was compared to non-treated straw. As storage conditions may affect dustiness, the study included treated straw kept for 4 weeks in sealed plastic bags. Dustiness of the chopped straw was measured in terms of the potential of the straw to emit bioaerosols in a rotating drum. The LS-treated straw proved low in dustiness compared to the non-treated straw. The dustiness with respect to the mass of dust was reduced by at least a factor of 6, and for fungi and endotoxin the factors of reduction were 4 and 3, respectively. Dustiness of LS-treated straw kept in plastic bags was reduced by a factor of 2 for mass of dust and by a factor of 4 for endotoxin, but dustiness for fungi was increased by a factor of 3. It is concluded that lignosulfonate has potential as a dust suppressant for chopped straw.

  17. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Rosenberg, M.

    2010-01-01

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  18. Dusty star-forming galaxies at high redshift

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Caitlin M., E-mail: cmcasey.astro@gmail.com [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Institute for Astronomy, University of Hawai’i, 2680 Woodlawn Dr, Honolulu, HI 96822 (United States); Narayanan, Desika [Department of Physics and Astronomy, Haverford College, 370 Lancaster Avenue, Haverford, PA 19041 (United States); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

    2014-08-10

    Far-infrared and submillimeter wavelength surveys have now established the important role of dusty, star-forming galaxies (DSFGs) in the assembly of stellar mass and the evolution of massive galaxies in the Universe. The brightest of these galaxies have infrared luminosities in excess of 10{sup 13}L{sub ⊙} with implied star-formation rates of thousands of solar masses per year. They represent the most intense starbursts in the Universe, yet many are completely optically obscured. Their easy detection at submm wavelengths is due to dust heated by ultraviolet radiation of newly forming stars. When summed up, all of the dusty, star-forming galaxies in the Universe produce an infrared radiation field that has an equal energy density as the direct starlight emission from all galaxies visible at ultraviolet and optical wavelengths. The bulk of this infrared extragalactic background light emanates from galaxies as diverse as gas-rich disks to mergers of intense starbursting galaxies. Major advances in far-infrared instrumentation in recent years, both space-based and ground-based, has led to the detection of nearly a million DSFGs, yet our understanding of the underlying astrophysics that govern the start and end of the dusty starburst phase is still in nascent stage. This review is aimed at summarizing the current status of DSFG studies, focusing especially on the detailed characterization of the best-understood subset (submillimeter galaxies, who were summarized in the last review of this field over a decade ago, Blain et al., 2002), but also the selection and characterization of more recently discovered DSFG populations. We review DSFG population statistics, their physical properties including dust, gas and stellar contents, their environments, and current theoretical models related to the formation and evolution of these galaxies.

  19. Heat transfer to MHD oscillatory dusty fluid flow in a channel filled ...

    Indian Academy of Sciences (India)

    heat transfer of a dusty fluid through a rectangular channel under the influence of pulsatile pres- sure gradient and uniform magnetic field. Prakash et al (2011) investigated MHD free convective flow of a viscoelastic (Kuvshinski type) dusty gas through a porous medium induced by the motion of a semi-infinite flat plate under ...

  20. Quantifying Dustiness, Specific Allergens, and Endotoxin in Bulk Soya Imports

    Directory of Open Access Journals (Sweden)

    Howard J. Mason

    2017-11-01

    Full Text Available Soya is an important bulk agricultural product often transported by sea as chipped beans and/or the bean husks after pelletisation. There are proven allergens in both forms. Bulk handling of soya imports can generate air pollution containing dust, allergens, and pyrogens, posing health risks to dockside workers and surrounding populations. Using an International Organization for Standardization (ISO standardised rotating drum dustiness test in seven imported soya bulks, we compared the generated levels of dust and two major soya allergens in three particle sizes related to respiratory health. Extractable levels of allergen and endotoxin from the bulks showed 30–60 fold differences, with levels of one allergen (hydrophobic seed protein and endotoxin higher in husk. The generated levels of dust and allergens in the three particle sizes also showed very wide variations between bulks, with aerolysed levels of allergen influenced by both the inherent dustiness and the extractable allergen in each bulk. Percentage allergen aerolysed from pelletized husk—often assumed to be of low dustiness—after transportation was not lower than that from chipped beans. Thus, not all soya bulks pose the same inhalation health risk and reinforces the importance of controlling dust generation from handling all soya bulk to as low as reasonably practicable.

  1. Complex plasma experimental device–A test bed for studying dust ...

    Indian Academy of Sciences (India)

    A typical device for carrying out sophisticated and complex dusty plasma experiments is designed, fabricated and made operational at the Institute for Plasma Research, India. The device is named as complex plasma experimental device (CPED). The main aim of this multipurpose machine is to study the formation and ...

  2. PREVIOUS SECOND TRIMESTER ABORTION

    African Journals Online (AJOL)

    PNLC

    PREVIOUS SECOND TRIMESTER ABORTION: A risk factor for third trimester uterine rupture in three ... for accurate diagnosis of uterine rupture. KEY WORDS: Induced second trimester abortion - Previous uterine surgery - Uterine rupture. ..... scarred uterus during second trimester misoprostol- induced labour for a missed ...

  3. Dusty disks around central stars of planetary nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Geoffrey C. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); De Marco, Orsola [Department of Physics and Astronomy, Macquarie University, Sydney, NSW 2109 (Australia); Nordhaus, Jason [Center for Computational Relativity and Gravitation, and National Technical Institute for the Deaf, Rochester Institute of Technology, Rochester, NY 14623 (United States); Green, Joel [Department of Astronomy, The University of Texas, 1 University Station, C1400, Austin, TX 78712-0259 (United States); Rauch, Thomas; Werner, Klaus [Institute for Astronomy and Astrophysics, Kepler Center for Astro and Particle Physics, Eberhard Karls University, Sand 1, D-72076 Tübingen (Germany); Chu, You-Hua, E-mail: gclayton@fenway.phys.lsu.edu, E-mail: orsola@science.mq.edu.au, E-mail: nordhaus@astro.rit.edu, E-mail: joel@astro.as.utexas.edu, E-mail: rauch@astro.uni-tuebingen.de, E-mail: werner@astro.uni-tuebingen.de, E-mail: chu@astro.uiuc.edu [Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, IL 61801 (United States)

    2014-06-01

    Only a few percent of cool, old white dwarfs (WDs) have infrared excesses interpreted as originating in small hot disks due to the infall and destruction of single asteroids that come within the star's Roche limit. Infrared excesses at 24 μm were also found to derive from the immediate vicinity of younger, hot WDs, most of which are still central stars of planetary nebulae (CSPNe). The incidence of CSPNe with this excess is 18%. The Helix CSPN, with a 24 μm excess, has been suggested to have a disk formed from collisions of Kuiper belt-like objects (KBOs). In this paper, we have analyzed an additional sample of CSPNe to look for similar infrared excesses. These CSPNe are all members of the PG 1159 class and were chosen because their immediate progenitors are known to often have dusty environments consistent with large dusty disks. We find that, overall, PG 1159 stars do not present such disks more often than other CSPNe, although the statistics (five objects) are poor. We then consider the entire sample of CSPNe with infrared excesses and compare it to the infrared properties of old WDs, as well as cooler post-asymptotic giant branch (AGB) stars. We conclude with the suggestion that the infrared properties of CSPNe more plausibly derive from AGB-formed disks rather than disks formed via the collision of KBOs, although the latter scenario cannot be ruled out. Finally, there seems to be an association between CSPNe with a 24 μm excess and confirmed or possible binarity of the central star.

  4. Experiments in Ice Contaminant Remanent Magnetization of Dusty Frost Deposits

    Science.gov (United States)

    Grossman, Y.; Aharonson, O.; Shaar, R.

    2017-12-01

    Sedimentary rocks can acquire magnetization in the presence of an external field as grains settle out of suspension in a water column - a process known as Depositional Remanent Magnetization (DRM). In analogy with this, here we propose and experimentally demonstrate a new mechanism for acquisition of magnetization by ice and particulate mixtures which we term Ice Contaminant Remanent Magnetization (ICRM). This phenomenon results from the settling of atmospheric dust containing magnetic particles (e.g. magnetite or other iron oxides). Upon freezing, magnetic dust particles assume a preferential orientation that depends on the external planetary field, resulting in bulk magnetization of the dusty ice. Hence over geologic timescales, the ice stratigraphy is expected to record the geomagnetic history. To test this hypothesis, we designed a set of experiments in which mixtures of ice and dust were deposited in a controlled ambient magnetic field environment. We measured the ratio between the volume normalized magnetization of the dusty ice (m) and the applied field (H) during deposition of the mixture, which is expressed as the effective ICRM susceptibility: m=χICRMH. A magnetic field was applied by a 3-axis Helmholtz coil at the Weizmann Simulating Planetary Ices & Environments Laboratory, and the frozen samples were analyzed in a 2G-Entreprises SQUID Rock Magnetometer at the Hebrew University Institute for Earth Sciences. We measured a clear correlation in amplitude and direction between the ambient magnetic field applied during deposition and the remanent magnetic moment of the resulting samples. We studied various concentrations and particle sizes (diameters 5 µm to 50 µm) of iron and magnetite particles. Effective bulk susceptibilities show a range of values, starting from 10-3 and up to values that saturate the analytical instrument. Our preliminary results indicate that natural ice deposits may acquire variable magnetization due to ICRM, which may in turn be

  5. HST Ultraviolet Spectroscopy of the Dusty, Molecular Gas in Planck Cold Clumps

    Science.gov (United States)

    Dirks, Cody

    2018-01-01

    The Planck Catalogue of Galactic Cold Clumps (PGCC) has provided a wealth of information about the cold, dusty ISM across the entire sky, identifying regions ranging from relatively diffuse cold clouds to pre-stellar cores in giant molecular clouds. This catalogue uses sub-millimeter emission arising from cold dust to determine the physical properties, morphology, and temperature of these regions. By combining this data with existing Hubble Space Telescope high-resolution UV spectra, we can probe the gas within these objects with the diagnostic capabilities of absorption line spectroscopy. Using data from Planck, Gaia, and CO emission studies, we have identified 22 stars which lie behind a PGCC region, and thus whose sightlines probe the cold gas associated with these objects. Here we report results from our studies of these sightlines, comparing the dust depletion to previous work done in studies of the diffuse ISM In particular, we find that the dust depletion decreases as projected distance from the centers of nearby PGCCs increases. Furthermore, we investigate the CO content of the cold gas using the numerous CO absorption bands in the UV. Additionally, by using neutral chlorine as a fiducial for H2, we calculate the CO-to-H2 ratio and explore the abundance of CO-dark gas. Finally, we compare the 12CO/13CO ratio to previous all-sky surveys, finding that our sightlines tend to show higher 12CO/13CO ratios when compared to other samples of Galactic sightlines.

  6. Some new trends in plasma physics

    International Nuclear Information System (INIS)

    Murtaza, G.

    2001-01-01

    In this article author describes some recent developments in different areas of plasma physics i.e. nuclear fusion, plasma processing of materials, dusty plasma and plasma crystals. Fusion energy remains an important energy source. Nuclear fusion needs very high ion temperature to provide the kinetic energy to overcome the coulomb barrier. Energetic plasma particles activate the surface by producing radicals on the surface which interact with plasma species. Dust plasmas are of importance in many areas of active research, although the presence of dust is in some cases a very important factor. As the the dust particle number density is increased, collective effects become increasingly important, and at some point conditions are reached, where the dust particles have to be regarded as one of the components of the plasma. Plasma crystal is the term used to describe the recently discovered ordered state than colloidal plasma may assume under certain condition. (A.B.)

  7. FOREWORD: International Workshop on Theoretical Plasma Physics: Modern Plasma Science. Sponsored by the Abdus Salam ICTP, Trieste, Italy

    Science.gov (United States)

    Shukla, P. K.; Stenflo, L.

    2005-01-01

    The "International Workshop on Theoretical Plasma Physics: Modern Plasma Science was held at the Abdus Salam International Centre for Theoretical Physics (Abdus Salam ICTP), Trieste, Italy during the period 5 16 July 2004. The workshop was organized by P K Shukla, R Bingham, S M Mahajan, J T Mendonça, L Stenflo, and others. The workshop enters into a series of previous biennial activities that we have held at the Abdus Salam ICTP since 1989. The scientific program of the workshop was split into two parts. In the first week, most of the lectures dealt with problems concerning astrophysical plasmas, while in the second week, diversity was introduced in order to address the important role of plasma physics in modern areas of science and technology. Here, attention was focused on cross-disciplinary topics including Schrödinger-like models, which are common in plasma physics, nonlinear optics, quantum engineering (Bose-Einstein condensates), and nonlinear fluid mechanics, as well as emerging topics in fundamental theoretical and computational plasma physics, space and dusty plasma physics, laser-plasma interactions, etc. The workshop was attended by approximately hundred-twenty participants from the developing countries, Europe, USA, and Japan. A large number of participants were young researchers from both the developing and industrial countries, as the directors of the workshop tried to keep a good balance in inviting senior and younger generations of theoretical, computational and experimental plasma physicists to our Trieste activities. In the first week, there were extensive discussions on the physics of electromagnetic wave emissions from pulsar magnetospheres, relativistic magnetohydrodynamics of astrophysical objects, different scale sizes turbulence and structures in astrophysics. The scientific program of the second week included five review talks (60 minutes) and about thirty invited topical lectures (30 minutes). In addition, during the two weeks, there

  8. Laparoscopy After Previous Laparotomy

    Directory of Open Access Journals (Sweden)

    Zulfo Godinjak

    2006-11-01

    Full Text Available Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for laparoscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previouslaparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured.

  9. The complexity of parsec-scaled dusty tori in AGN

    Science.gov (United States)

    Tristram, K. R. W.; Schartmann, M.; Burtscher, L.; Meisenheimer, K.; Jaffe, W.; Kishimoto, M.; Hönig, S. F.; Weigelt, G.

    2012-07-01

    Warm gas and dust surround the innermost regions of active galactic nuclei (AGN). They provide the material for accretion onto the super-massive black hole and they are held responsible for the orientation-dependent obscuration of the central engine. The AGN-heated dust distributions turn out to be very compact with sizes on scales of about a parsec in the mid-infrared. Only infrared interferometry currently provides the necessary angular resolution to directly study the physical properties of this dust. Size estimates for the dust distributions derived from interferometric observations can be used to construct a size-luminosity relation for the dust distributions. The large scatter about this relation suggests significant differences between the dust tori in the individual galaxies, even for nuclei of the same class of objects and with similar luminosities. This questions the simple picture of the same dusty doughnut in all AGN. The Circinus galaxy is the closest Seyfert 2 galaxy. Because its mid-infrared emission is well resolved interferometrically, it is a prime target for detailed studies of its nuclear dust distribution. An extensive new interferometric data set was obtained for this galaxy. It shows that the dust emission comes from a very dense, disk-like structure which is surrounded by a geometrically thick, similarly warm dust distribution as well as significant amounts of warm dust within the ionisation cone.

  10. Performance Evaluation of PV Panel Under Dusty Condition

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar Tripathi

    2017-11-01

    Full Text Available The performance of PV panel depends on the incoming sunlight on its surface. The accumulated airborne dust particles on panel surface creates a barrier in the path of sunlight and panel surface, which significantly reduces the amount of solar radiation falling on the panel surface. The present study shows a significant reduction in short circuit current and power output of PV panel due to dust deposition on its surface, whereas the reduction in open circuit voltage is not much prominent. This study has been carried in the field as well as in the laboratory. The reduction in maximum power output of PV panel for both the studies ensures a linear relation with the dust deposition on its surface. In the field study, the reduction in the power output due to 12.86gm of dust deposition on the panel surface was 43.18%, whereas in the laboratory study it was 44.75% due to 11gm of dust deposition Article History: Received July 10th 2017; Received in revised form Sept 15th 2017x; Accepted 1st Oct 2017; Available online How to Cite This Article: Tripathi, A.K., Aruna, M. and Murthy, Ch.,S.N. (2017. Performance Evaluation of PV Panel Under Dusty Condition. International Journal of Renewable Energy Develeopment, 6(3, 225-233. https://doi.org/10.14710/ijred.6.3.225-233

  11. Analog Experiments on Tensile Strength of Dusty and Cometary Matter

    Science.gov (United States)

    Musiolik, Grzegorz; de Beule, Caroline; Wurm, Gerhard

    2017-11-01

    The tensile strength of small dusty bodies in the solar system is determined by the interaction between the composing grains. In the transition regime between small and sticky dust (μm) and non cohesive large grains (mm), particles still stick to each other but are easily separated. In laboratory experiments we find that thermal creep gas flow at low ambient pressure generates an overpressure sufficient to overcome the tensile strength. For the first time it allows a direct measurement of the tensile strength of individual, very small (sub)-mm aggregates which consist of only tens of grains in the (sub)-mm size range. We traced the disintegration of aggregates by optical imaging in ground based as well as microgravity experiments and present first results for basalt, palagonite and vitreous carbon samples with up to a few hundred Pa. These measurements show that low tensile strength can be the result of building loose aggregates with compact (sub)-mm units. This is in favour of a combined cometary formation scenario by aggregation to compact aggreates and gravitational instability of these units.

  12. International Conference on Plasma Diagnostics. Slides, papers and posters of Plasma Diagnostics 2010

    International Nuclear Information System (INIS)

    Hartfuss, H.J.; Bonhomme, G.; Grisolia, C.; Hirsch, M.; Klos, Z.; Mazouffre, S.; Musielok, J.; Ratynskaya, S.; Sadowski, M.; Van de Sanden, R.; Sentis, M.; Stroth, U.; Tereshin, V.; Tichy, M.; Unterberg, B.; Weisen, H.; Zoletnik, S.

    2011-01-01

    Plasma diagnostics 2010 is an International Conference on Diagnostic Methods involved in Research and Applications of Plasmas, originating on combining the 5. German-Polish Conference on Plasma Diagnostics for Fusion and Applications and the 7. French-Polish Seminar on Thermal Plasma in Space and Laboratory. The Scientific Committee of 'Plasma 2007' decided to concentrate the attention of future conferences more on the diagnostic development and diagnostic interpretation in the fields of high and low temperature plasmas and plasma applications. It is aimed at involving all European activities in the fields. The Scientific Program will cover the fields from low temperature laboratory to fusion plasmas of various configurations as well as dusty and astrophysical plasmas and industrial plasma applications

  13. Theory of sheath in a collisional multi-component plasma

    Indian Academy of Sciences (India)

    gate the interaction between a dusty plasma and a solid boundary. It has been mentioned that dust strongly influences all parameters of the sheath, in par- ticular, the electric field distributions and the ion flow velocities. The electric field of dust particles contributes to the distribution of the electric potential in the sheath and ...

  14. Influence of relative humidity and physical load during storage on dustiness of inorganic nanomaterials: implications for testing and risk assessment

    International Nuclear Information System (INIS)

    Levin, Marcus; Rojas, Elena; Vanhala, Esa; Vippola, Minnamari; Liguori, Biase; Kling, Kirsten I.; Koponen, Ismo K.; Mølhave, Kristian; Tuomi, Timo; Gregurec, Danijela; Moya, Sergio; Jensen, Keld A.

    2015-01-01

    Dustiness testing using a down-scaled EN15051 rotating drum was used to investigate the effects of storage conditions such as relative humidity and physical loading on the dustiness of five inorganic metal oxide nanostructured powder materials. The tests consisted of measurements of gravimetrical respirable dustiness index and particle size distributions. Water uptake of the powders during 7 days of incubation was investigated as an explanatory factor of the changes. Consequences of these varying storage conditions in exposure modelling were tested using the control banding and risk management tool NanoSafer. Drastic material-specific effects on powder respirable dustiness index were observed with the change in TiO 2 from 30 % RH (639 mg/kg) to 50 % RH (1.5 mg/kg). All five tested materials indicate a decreasing dustiness index with relative humidity increasing from 30 to 70 % RH. Test of powder water uptake showed an apparent link with the decreasing dustiness index. Effects of powder compaction appeared more material specific with both increasing and decreasing dustiness indices observed as an effect of compaction. Tests of control banding exposure models using the measured dustiness indices in three different exposure scenarios showed that in two of the tested materials, one 20 % change in RH changed the exposure banding from the lowest level to the highest. The study shows the importance of powder storage conditions prior to tests for classification of material dustiness indices. It also highlights the importance of correct storage information and relative humidity and expansion of the dustiness test conditions specifically, when using dustiness indices as a primary parameter for source strength in exposure assessment

  15. Rise of the Titans: A Dusty, Hyper-luminous “870 μm Riser” Galaxy at z ˜ 6

    Science.gov (United States)

    Riechers, Dominik A.; Leung, T. K. Daisy; Ivison, Rob J.; Pérez-Fournon, Ismael; Lewis, Alexander J. R.; Marques-Chaves, Rui; Oteo, Iván; Clements, Dave L.; Cooray, Asantha; Greenslade, Josh; Martínez-Navajas, Paloma; Oliver, Seb; Rigopoulou, Dimitra; Scott, Douglas; Weiss, Axel

    2017-11-01

    We report the detection of ADFS-27, a dusty, starbursting major merger at a redshift of z = 5.655, using the Atacama Large Millimeter/submillimeter Array (ALMA). ADFS-27 was selected from Herschel/Spectral and Photometric Imaging Receiver (SPIRE) and APEX/LABOCA data as an extremely red “870 μm riser” (I.e., {S}250μ {{m}}< {S}350μ {{m}}< {S}500μ {{m}}< {S}870μ {{m}}), demonstrating the utility of this technique to identify some of the highest-redshift dusty galaxies. A scan of the 3 mm atmospheric window with ALMA yields detections of CO(J = 5 → 4) and CO(J = 6 → 5) emission, and a tentative detection of H2O(211 → 202) emission, which provides an unambiguous redshift measurement. The strength of the CO lines implies a large molecular gas reservoir with a mass of M gas = 2.5 × 1011 ({α }{CO}/0.8)(0.39/{r}51) M ⊙, sufficient to maintain its ˜2400 M ⊙ yr-1 starburst for at least ˜100 Myr. The 870 μm dust continuum emission is resolved into two components, 1.8 and 2.1 kpc in diameter, separated by 9.0 kpc, with comparable dust luminosities, suggesting an ongoing major merger. The infrared luminosity of L IR ≃ 2.4 × 1013 L ⊙ implies that this system represents a binary hyper-luminous infrared galaxy, the most distant of its kind presently known. This also implies star formation rate surface densities of {{{Σ }}}{SFR}=730 and 750 M ⊙ yr-1 kpc2, consistent with a binary “maximum starburst.” The discovery of this rare system is consistent with a significantly higher space density than previously thought for the most luminous dusty starbursts within the first billion years of cosmic time, easing tensions regarding the space densities of z ˜ 6 quasars and massive quiescent galaxies at z ≳ 3.

  16. Parametric study of the relaxation zone behind strong normal shock waves in a dusty ionized monatomic gas

    International Nuclear Information System (INIS)

    Igra, O.; Ben-Dor, G.

    1982-01-01

    The conservation equations appropriate to a steady, one-dimensional flow of dusty ionized argon were solved numerically. The specific effect of each of the physical parameters of the dust upon the flow properties in the relaxation zone is studied. It is found that increasing the dust particle mass causes an increase in both the kinematic and thermal relaxation lengths. In addition to these changes, the flow field inside the relaxation zone is also affected. An increase in the dust mass (caused either by an increase in the dust density or its diameter) causes an increase in the plasma velocity, temperature and electron number density and a decrease in its density and pressure. Similar effects are encountered when the specific heat capacity of the dust is changed. An increase in the emissivity of the dust causes an increase in the plasma density and pressure and a decrease in its velocity, temperature and electron number density. Increasing the emissivity of the dust results in a decrease in the relaxation zone length. (author)

  17. Exposure Assessment of Four Pharmaceutical Powders Based on Dustiness and Evaluation of Damaged HEPA Filters

    DEFF Research Database (Denmark)

    Levin, Marcus; Koponen, Ismo K.; Jensen, Keld A.

    2014-01-01

    In this study, we show the different dustiness characteristics of four molecular pharmaceutical powder candidates and evaluate the performance of HEPA filters damaged with three different pinhole sizes and exposed to dust using real industrial powders in a miniaturized EN15051 rotating drum...... number time-series of a complete dustiness test. It provides information on the HEPA-filter used including a scanning electron microscopy image of it. It also provides APS-measurements of particles penetrating the damaged HEPA-filter.]...... modeling in a 5times 20kg powder pouring scenario, suggests that excessive dust concentrations may be reached during use of powders with the highest dustiness levels. By number, filter-damage by three pinhole sizes resulted in damage-dependent penetration of 70-80nm-size particles, but by volume and mass...

  18. Influence of relative humidity and physical load during storage on dustiness of inorganic nanomaterials: implications for testing and risk assessment

    DEFF Research Database (Denmark)

    Levin, Marcus; Rojas, Elena; Vanhala, Esa

    2015-01-01

    Dustiness testing using a down-scaled EN15051 rotating drum was used to investigate the effects of storage conditions such as relative humidity and physical loading on the dustiness of five inorganic metal oxide nanostructured powder materials. The tests consisted of measurements of gravimetrical...

  19. Breathing-mode resonance of a complex plasma disk

    International Nuclear Information System (INIS)

    Sheridan, T.E.; Buckey, C.R.; Cox, D.J.; Merrill, R.J.; Theisen, W.L.

    2004-01-01

    We have experimentally characterized the breathing mode oscillation of a strongly-coupled, dusty plasma disk. Steady-state oscillations are excited by sinusoidally modulating the plasma density, creating a single-frequency, in-plane driving force. Resonance curves agree well with damped harmonic oscillator theory. A response at the second harmonic is observed and found to increase with the square of the driving force, indicating a quadratic nonlinearity

  20. Molecular gas in dusty high-redshift galaxies

    Science.gov (United States)

    Sharon, Chelsea Electra

    2013-12-01

    We present high-resolution observations of carbon monoxide (CO) emission lines for three high-redshift galaxies in order to determine their molecular gas and star formation properties. These galaxies (SMM J14011+0252, SMM J00266+1708, and SDSS J0901+1814) have large infrared luminosities, which imply high dust enshrouded star formation rates and substantial molecular gas masses. We observed these sources using the Robert C. Byrd Green Bank Telescope, the Karl G. Jansky Very Large Array, the Plateau de Bure Interferometer, and the Submillimeter Array in order to obtain measurements of multiple CO spectral lines, allowing us to determine the physical conditions of the molecular gas. Our high resolution and multi-line CO mapping of SMM J00266+1708 reveals that it is a pair of merging galaxies, whose two components have different gas excitation conditions and different gas kinematics. For SMM J14011+0252 (J14011), we find a near-unity CO(3--2)/CO(1--0) intensity ratio, consistent with a single phase (i.e., a single temperature and density) of molecular gas and different from the average population value for dusty galaxies selected at submillimeter wavelengths. Our radiative transfer modeling (using the large velocity gradient approximation) indicates that converting the CO line luminosity to molecular gas mass requires a Galactic (disk-like) scale factor rather than the typical conversion factor assumed for starbursts. Despite this choice of conversion factor, J14011 falls in the same region of star formation rate surface density and gas mass surface density (the Schmidt-Kennicutt relation) as other starburst galaxies. SDSS J0901+1814 (J0901) was initially selected as a star-forming galaxy at ultraviolet wavelengths, but also has a large infrared luminosity. We use the magnification provided by the strong gravitational lensing affecting this system to examine the spatial variation of the CO excitation within J0901. We find that the CO(3--2)/CO(1--0) line ratio is

  1. Coupled Gas-Liquid Diffusion in Porous Media Using the Dusty Gas Model

    Science.gov (United States)

    Webb, S. W.; Pruess, K.

    2001-12-01

    Numerous problems involve the simultaneous diffusion of chemical species in both aqueous and gaseous phases. Applications include diffusion of non-condensible gases including carbon sequestration, volatile organic compounds (VOCs), and chemicals from buried landmines. Diffusion in the unsaturated zone involves simultaneous transport in the aqueous and gaseous pathways. Calculation of diffusion in the individual phases is straightforward. However, for simultaneous diffusion in both phases, simply adding diffusive fluxes in gas and liquid phases will in general not be correct. Proper treatment of diffusion in multiphase conditions must take into account the coupling between diffusion and phase partitioning. Coupled gas-liquid diffusion was previously considered using Fick's law for both aqueous and gaseous diffusion. The diffusive strength term was harmonically weighted at the interface to enforce mass conservation. Results showed that the coupling effects are significant, and that uncoupled results can seriously underestimate diffusion across a capillary fringe. In the present work, the Dusty Gas Model (DGM) has been used to model gas diffusion. The DGM is a more fundamentally sound model for gas diffusion than Fick's law. However, the formulation of multiphase diffusion coupled with gas-liquid phase partitioning becomes considerably more complicated, and mass conservation must be explicitly imposed on each component through solution for the appropriate interface conditions. For higher permeability and trace gas conditions, the two models (Fick's law and DGM) give similar results as expected. However, for lower permeability media and non-trace gas conditions, significant differences exist. This work was supported by the U.S Department of Energy under Contracts No. DE-AC04-94AL85000 and DE-AC03-76SF00098.

  2. THE REDSHIFT DISTRIBUTION OF DUSTY STAR-FORMING GALAXIES FROM THE SPT SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Strandet, M. L.; Weiss, A. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69 D-53121 Bonn (Germany); Vieira, J. D.; Furstenau, R. M. [European Southern Observatory, Karl Schwarzschild Straße 2, D-85748 Garching (Germany); De Breuck, C.; Béthermin, M.; Gullberg, B. [Department of Astronomy and Department of Physics, University of Illinois, 1002 West Green St., Urbana, IL 61801 (United States); Aguirre, J. E. [University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Aravena, M. [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bradford, C. M. [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Carlstrom, J. E.; Crawford, T. M. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Chapman, S. C. [Dalhousie University, Halifax, Nova Scotia (Canada); Everett, W. [Department of Astrophysical and Planetary Sciences and Department of Physics, University of Colorado, Boulder, CO 80309 (United States); Fassnacht, C. D. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Gonzalez, A. H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Hezaveh, Y. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); and others

    2016-05-10

    We use the Atacama Large Millimeter/submillimeter Array (ALMA) in Cycle 1 to determine spectroscopic redshifts of high-redshift dusty star-forming galaxies (DSFGs) selected by their 1.4 mm continuum emission in the South Pole Telescope (SPT) survey. We present ALMA 3 mm spectral scans between 84 and 114 GHz for 15 galaxies and targeted ALMA 1 mm observations for an additional eight sources. Our observations yield 30 new line detections from CO, [C i], [N ii], H{sub 2}O and NH{sub 3}. We further present Atacama Pathfinder Experiment [C ii] and CO mid- J observations for seven sources for which only a single line was detected in spectral-scan data from ALMA Cycle 0 or Cycle 1. We combine the new observations with previously published and new millimeter/submillimeter line and photometric data of the SPT-selected DSFGs to study their redshift distribution. The combined data yield 39 spectroscopic redshifts from molecular lines, a success rate of >85%. Our sample represents the largest data set of its kind today and has the highest spectroscopic completeness among all redshift surveys of high- z DSFGs. The median of the redshift distribution is z = 3.9 ± 0.4, and the highest-redshift source in our sample is at z = 5.8. We discuss how the selection of our sources affects the redshift distribution, focusing on source brightness, selection wavelength, and strong gravitational lensing. We correct for the effect of gravitational lensing and find the redshift distribution for 1.4 mm selected sources with a median redshift of z = 3.1 ± 0.3. Comparing to redshift distributions selected at shorter wavelengths from the literature, we show that selection wavelength affects the shape of the redshift distribution.

  3. Heat transfer in MHD flow of dusty viscoelastic (Walters' liquid model ...

    Indian Academy of Sciences (India)

    Heat transfer in MHD flow of dusty viscoelastic (Walters' liquid model-B) stratified fluid in porous medium under variable viscosity. Om Prakash ... Expressions for the velocity of fluid and particle phases, temperature field, Nusselt number, skin friction and flow flux are obtained within the channel. The effects of various ...

  4. The effect of surface coatings on the dustiness of a calcium carbonate nanopowder

    International Nuclear Information System (INIS)

    Burdett, Garry; Bard, Delphine; Kelly, Alexandra; Thorpe, Andrew

    2013-01-01

    Six calcium carbonate nanopowders that had been functionalized (coated) to enhance their use in a range of industrial applications were compared to the uncoated nanopowder (15–30-nm size range) from which they were made. The nanopowders were first characterized using the standard gravimetric rotating drum dustiness test (EN 15051 2006). All the functionalized powders showed a substantial increase in dustiness compared with the uncoated sample. The largest increase was some ×45, ×90 and ×331 higher for the inhalable, thoracic and respirable fractions, respectively, and would potentially give rise to much higher exposures to workers handling these powders. This article also investigated a range of additional measurement methods to extend the standard dustiness test to measure the particle size distribution and particle number concentrations. Several online instruments were compared in two sets of tests, as well as, offline transmission electron microscopy analysis. The results of these tests are discussed to assess the suitability and limitations of the measurement methods and to assess the best approach for extending the current gravimetric standard to include number concentration and size distribution measurements. It was concluded that questions remain over the performance characteristics of online charge detection instruments such as the FMPS and ELPI for dustiness testing, and such issues need to be resolved before a standardized test can be finalized.

  5. EXTINCTION LAWS TOWARD STELLAR SOURCES WITHIN A DUSTY CIRCUMSTELLAR MEDIUM AND IMPLICATIONS FOR TYPE IA SUPERNOVAE

    International Nuclear Information System (INIS)

    Nagao, Takashi; Maeda, Keiichi; Nozawa, Takaya

    2016-01-01

    Many astronomical objects are surrounded by dusty environments. In such dusty objects, multiple scattering processes of photons by circumstellar (CS) dust grains can effectively alter extinction properties. In this paper, we systematically investigate the effects of multiple scattering on extinction laws for steady-emission sources surrounded by the dusty CS medium using a radiation transfer simulation based on the Monte Carlo technique. In particular, we focus on whether and how the extinction properties are affected by properties of CS dust grains by adopting various dust grain models. We confirm that behaviors of the (effective) extinction laws are highly dependent on the properties of CS grains, especially the total-to-selective extinction ratio R V , which characterizes the extinction law and can be either increased or decreased and compared with the case without multiple scattering. We find that the criterion for this behavior is given by a ratio of albedos in the B and V bands. We also find that either small silicate grains or polycyclic aromatic hydrocarbons are necessary for realizing a low value of R V as often measured toward SNe Ia if the multiple scattering by CS dust is responsible for their non-standard extinction laws. Using the derived relations between the properties of dust grains and the resulting effective extinction laws, we propose that the extinction laws toward dusty objects could be used to constrain the properties of dust grains in CS environments.

  6. EXTINCTION LAWS TOWARD STELLAR SOURCES WITHIN A DUSTY CIRCUMSTELLAR MEDIUM AND IMPLICATIONS FOR TYPE IA SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Nagao, Takashi; Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Nozawa, Takaya, E-mail: nagao@kusastro.kyoto-u.ac.jp [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2016-06-01

    Many astronomical objects are surrounded by dusty environments. In such dusty objects, multiple scattering processes of photons by circumstellar (CS) dust grains can effectively alter extinction properties. In this paper, we systematically investigate the effects of multiple scattering on extinction laws for steady-emission sources surrounded by the dusty CS medium using a radiation transfer simulation based on the Monte Carlo technique. In particular, we focus on whether and how the extinction properties are affected by properties of CS dust grains by adopting various dust grain models. We confirm that behaviors of the (effective) extinction laws are highly dependent on the properties of CS grains, especially the total-to-selective extinction ratio R{sub V}, which characterizes the extinction law and can be either increased or decreased and compared with the case without multiple scattering. We find that the criterion for this behavior is given by a ratio of albedos in the B and V bands. We also find that either small silicate grains or polycyclic aromatic hydrocarbons are necessary for realizing a low value of R{sub V} as often measured toward SNe Ia if the multiple scattering by CS dust is responsible for their non-standard extinction laws. Using the derived relations between the properties of dust grains and the resulting effective extinction laws, we propose that the extinction laws toward dusty objects could be used to constrain the properties of dust grains in CS environments.

  7. A miniature sensor for electrical field measurements in dusty planetary atmospheres

    International Nuclear Information System (INIS)

    Renno, N O; Rogacki, S; Kok, J F; Kirkham, H

    2008-01-01

    Dusty phenomena such as regular wind-blown dust, dust storms, and dust devils are the most important, currently active, geological processes on Mars. Electric fields larger than 100 kV/m have been measured in terrestrial dusty phenomena. Theoretical calculations predict that, close to the surface, the bulk electric fields in martian dusty phenomena reach the breakdown value of the isolating properties of thin martian air of about a few 10 kV/m. The fact that martian dusty phenomena are electrically active has important implications for dust lifting and atmospheric chemistry. Electric field sensors are usually grounded and distort the electric fields in their vicinity. Grounded sensors also produce large errors when subject to ion currents or impacts from clouds of charged particles. Moreover, they are incapable of providing information about the direction of the electric field, an important quantity. Finally, typical sensors with more than 10 cm of diameter are not capable of measuring electric fields at distances as small as a few cm from the surface. Measurements this close to the surface are necessary for studies of the effects of electric fields on dust lifting. To overcome these shortcomings, we developed the miniature electric-field sensor described in this article.

  8. Quartz dustiness: A key factor in controlling exposure to crystalline silica in the workplace.

    Science.gov (United States)

    López-Lilao, A; Escrig, A; Orts, M J; Mallol, Gustavo; Monfort, E

    2016-11-01

    The classification of Respirable Crystalline Silica (RCS) as carcinogenic for humans has drawn greater attention to crystalline silica exposure in the workplace in recent years, leading to recommendations by safety and health bodies in Europe and the U.S. for lower occupational exposure limits. In view of this new scenario, the present study examined quartz dustiness, as quartz handling is a major source of crystalline silica in the workplace. The study was conducted on test samples with different mean particle sizes, prepared from several commercial quartzes. The quartz particle samples were characterised and the influence of certain quartz particle parameters on quartz dustiness was determined. The results indicate that quartz dustiness may be significantly affected by mean particle size, specific surface area, the Hausner ratio, and fine particle content. The study shows that, in order to minimise the adverse health effects associated with the inhalation of crystalline silica, quartz dustiness may be deemed a key factor in controlling the generation of fugitive quartz emissions during quartz processing, both into the outside atmosphere (air pollution) and inside the facilities (occupational health).

  9. Heat transfer in MHD flow of dusty viscoelastic (Walters' liquid model ...

    Indian Academy of Sciences (India)

    December 2012 physics pp. 1457–1470. Heat transfer in MHD flow of dusty viscoelastic. (Walters' liquid model-B) stratified fluid in porous medium under variable viscosity ... in chemical technology and industry. Walters [1] ... treating environment pollution, in the petroleum industry, in the purification of rain water etc. Several ...

  10. APEX (Air Pollution Exercise) Volume 10: Industrialist's Manual No. 6, Dusty Rhodes' Cement Company.

    Science.gov (United States)

    Environmental Protection Agency, Research Triangle Park, NC. Office of Manpower Development.

    The Industrialist's Manual No. 6, Dusty Rhodes' Cement Company is part of a set of 21 manuals (AA 001 009-001 029) used in APEX (Air Pollution Exercise), a computerized college and professional level "real world" game simulation of a community with urban and rural problems, industrial activities, and air pollution difficulties. The first two…

  11. Near-IR spectral evolution of dusty starburst galaxies

    Science.gov (United States)

    Lançon, Ariane; Rocca-Volmerange, Brigitte

    1996-11-01

    We propose a multicomponent analysis of starburst galaxies, based on a model that takes into account the young and evolved stellar components and the gas emission, with their respective extinction, in the frame of a coherent dust distribution pattern. Near-IR signatures are preferentially investigated, in order to penetrate as deep as possible into the dusty starburst cores. We computed the 1.4-2.5 μm spectra of synthetic stellar populations evolving through strong, short timescale bursts of star formation (continuum and lines, R ≃ 500). The evolution model is specifically sensitive to cool stellar populations (AGB and red supergiant stars). It takes advantage of the stellar library of Lançon & Rocca-Volmerange (1992) [A&ASS, 96, 593], observed with the same instrument (FTS/CFHT) as the analysed galaxy sample, so that the instrumental effects are minimised. The main near-IR observable constraints are the molecular signatures of CO and H2O and the slope of the continuum, observed over a range exceptionally broad for spectroscopic data. The H - K colour determined from the spectra measures the intrinsic stellar energy distribution but also differential extinction, which is further constrained by optical emission line ratios. Other observational constraints are the near-IR emission lines (Brγ, He I 2.06 μm, [Fe II] 1.64 μm, H2 2.12 μm) and the far-IR luminosity. The coherence of the results relies on the interpretation in terms of stellar populations from which all observable properties are derived, so that the link between the various wavelength ranges is secured. The luminosity LK is used for the absolute calibration. We apply this approach to the typical spectrum of the core of NGC 1614. Consistent solutions for the starburst characteristics (star-formation rate, IMF, burst age, morphology) are found and the role of each observational constraint in deriving satisfactory models is extensively discussed. The acceptable contamination of the K band light by the

  12. Plasma crystals: experiments and simulation

    Science.gov (United States)

    Piel, A.

    2017-01-01

    Dusty plasmas are a well accessible system to study crystallization of charged-particle systems at room temperature. The large mass compared to atomic particles dramatically slows down the particle velocities. The high transparency of the system allows to trace simultaneously the motion of all particles with quasi-atomic resolution. After a brief overview, the progress in this field is exemplified by studies of spherical three-dimensional plasma crystals, the so-called Yukawa balls. The static structure and eigenmodes are explained in simple terms. It is shown that shielding modifies the expansion of a Yukawa ball from a self-similar explosion to a continuous ablation process that starts at the surface. The experimental progress with three-dimensional diagnostics and laser heating and sophisticated methods for visualising the order inside the shell structure are described. Together with quantifying the diffusion coefficient these investigations reveal the details of the solid-liquid phase transition. Besides thermodynamic aspects, the liquid phase of dusty plasmas also gives access to hydrodynamic phenomena at the individual particle scale.

  13. Dust-ion-acoustic Gardner double layers in a dusty plasma with two ...

    Indian Academy of Sciences (India)

    and dimensionless parameter, and can be considered as the expansion parameter ϵ, i.e.,. |σ − σc| ≃ ϵ and s = 1 for σ >σc and s = −1 for σ <σc. So, ρ(2) can be described as. ϵ2ρ(2) ≃ −ϵ3 1. 2 c1sψ2,. (13) which, then, must be included in the third-order Poisson's equation. To the next higher order in ϵ, we get the following ...

  14. Dust-ion-acoustic Gardner double layers in a dusty plasma with two ...

    Indian Academy of Sciences (India)

    Author Affiliations. M M Masud1 I Tasnim2 A A Mamun3. Department of Physics, Bangladesh University of Engineering & Technology, Dhaka, Bangladesh; Department of Physics, Begum Rokeya University, Rangpur, Bangladesh; Department of Physics, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh ...

  15. Effect of ion suprathermality on arbitrary amplitude dust acoustic waves in a charge varying dusty plasma

    International Nuclear Information System (INIS)

    Tribeche, Mouloud; Mayout, Saliha; Amour, Rabia

    2009-01-01

    Arbitrary amplitude dust acoustic waves in a high energy-tail ion distribution are investigated. The effects of charge variation and ion suprathermality on the large amplitude dust acoustic (DA) soliton are then considered. The correct suprathermal ion charging current is rederived based on the orbit motion limited approach. In the adiabatic case, the variable dust charge is expressed in terms of the Lambert function and we take advantage of this transcendental function to show the existence of rarefactive variable charge DA solitons involving cusped density humps. The dust charge variation leads to an additional enlargement of the DA soliton, which is less pronounced as the ions evolve far away from Maxwell-Boltzmann distribution. In the nonadiabatic case, the dust charge fluctuation may provide an alternate physical mechanism causing anomalous dissipation the strength of which becomes important and may prevail over that of dispersion as the ion spectral index κ increases. Our results may provide an explanation for the strong spiky waveforms observed in auroral electric field measurements by Ergun et al.[Geophys. Res. Lett. 25, 2025 (1998)].

  16. Spiral waves in driven dusty plasma medium: Generalized hydrodynamic fluid description

    Science.gov (United States)

    Kumar, Sandeep; Patel, Bhavesh; Das, Amita

    2018-04-01

    Spiral waves are observed in many natural phenomena. They have been extensively represented by the mathematical FitzHugh-Nagumo model [Barkley et al., Phys. Rev. A 42, 2489 (1990)] of excitable media. Also, in incompressible fluid simulations, the excitation of thermal spiral waves has been reported by Li et al. [Phys. of Fluids 22, 011701 (2010)]. In the present paper, the spatiotemporal development of spiral waves in the context of weak and strong coupling limits has been shown. While the weakly coupled medium has been represented by a simple fluid description, for strong coupling, a generalized visco-elastic fluid description has been employed. The medium has been driven by an external force in the form of a rotating electric field. It is shown that when the amplitude of force is small, the density perturbations in the medium are also small. In this case, the excitations do not develop as a spiral wave. Only when the amplitude of force is high so as to drive the density perturbations to nonlinear amplitudes does the spiral density wave formation occurs. The role of the forcing frequency and the effect of strong coupling and the sound velocity of medium in the formation and evolution of spiral waves have been investigated in detail.

  17. Dust-acoustic waves modulational instability and rogue waves in a polarized dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bouzit, Omar; Tribeche, Mouloud [Faculty of Physics, Theoretical Physics Laboratory, Plasma Physics Group, University of Bab-Ezzouar, USTHB, B.P. 32, El Alia, Algiers 16111 (Algeria)

    2015-10-15

    The polarization force-induced changes in the dust-acoustic waves (DAWs) modulational instability (MI) are examined. Using the reductive perturbation method, the nonlinear Schrödinger equation that governs the MI of the DAWs is obtained. It is found that the effect of the polarization term R is to narrow the wave number domain for the onset of instability. The amplitude of the wave envelope decreases as R increases, meaning that the polarization force effects render weaker the associated DA rogue waves. The latter may therefore completely damp in the vicinity of R ∼ 1, i.e., as the polarization force becomes close to the electrostatic one (the net force acting on the dust particles becomes vanishingly small). The DA rogue wave profile is very sensitive to any change in the restoring force acting on the dust particles. It turns out that the polarization effects may completely smear out the DA rogue waves.

  18. Propagation of ion-acoustic waves in a dusty plasma with non ...

    Indian Academy of Sciences (India)

    isothermal electrons and cold, massive and charged dust grains, the Sagdeev potential equation, considering both ion dynamics and dust dynamics has been derived. It has been observed that the Sagdeev potential () exists only for > 0 up to an ...

  19. KP Equation in a Three-Dimensional Unmagnetized Warm Dusty ...

    Indian Academy of Sciences (India)

    Plasma Physics and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Authority, P. O. Box 13759, Cairo, Egypt. Mathematics Division, School of Arts and Sciences, American University in Dubai, P. O. Box 28282, Dubai, UAE. Physics Department, Faculty of Science, Tanta University, Tanta 31527, Egypt.

  20. Millennial-scale variations in dustiness recorded in Mid-Atlantic sediments from 0 to 70 ka

    Science.gov (United States)

    Middleton, Jennifer L.; Mukhopadhyay, Sujoy; Langmuir, Charles H.; McManus, Jerry F.; Huybers, Peter J.

    2018-01-01

    Sedimentary records of dust deposition in the subtropical Atlantic provide important constraints on millennial- and orbital-scale variability in atmospheric circulation and North African aridity. Constant flux proxies, such as extraterrestrial helium-3, yield dust flux records that are independent of the biases caused by lateral sediment transport and limited resolution that may be associated with age-model-derived mass accumulation rates. However, Atlantic dust records constrained using constant flux proxies are sparsely distributed and generally limited to the past 20 ka. Here we extend the Atlantic record of North African dust deposition to 70 ka using extraterrestrial helium-3 and measurements of titanium, thorium, and terrigenous helium-4 in two sediment cores collected at 26°N and 29°N on the Mid-Atlantic Ridge and compare results to model estimates for dust deposition in the subtropical North Atlantic. Dust proxy fluxes between 26°N and 29°N are well correlated, despite variability in lateral sediment transport, and underscore the utility of extraterrestrial helium-3 for constraining millennial-scale variability in dust deposition. Similarities between Mid-Atlantic dust flux trends and those observed along the Northwest African margin corroborate previous interpretations of dust flux variability over the past 20 ka and suggest that long distance transport and depositional processes do not overly obscure the signal of North African dust emissions. The 70 ka Mid-Atlantic record reveals a slight increase in North African dustiness from Marine Isotope Stage 4 through the Last Glacial Maximum and a dramatic decrease in dustiness associated with the African Humid Period. On the millennial-scale, the new records exhibit brief dust maxima coincident with North Atlantic cold periods such as the Younger Dryas, and multiple Heinrich Stadials. The correlation between Mid-Atlantic dust fluxes and previous constraints on North African aridity is high. However

  1. Complex plasma experimental device – A test bed for studying dust ...

    Indian Academy of Sciences (India)

    2016-11-03

    Nov 3, 2016 ... under microgravity experiments. This set-up is equip- ped with a specially designed Langmuir probe sys- tem, capable of working in a dusty plasma environment at high pressures, and a sophisticated high-resolution camera with high frame grabbing capability, in order to perform direct measurements of the ...

  2. Nonlinear dust-ion-acoustic waves in a multi-ion plasma with ...

    Indian Academy of Sciences (India)

    -1100, Bangladesh. ∗. Corresponding author. E-mail: shadab22@yahoo.com; sduha@yahoo.com. MS received 13 September 2010; revised 22 December 2010; accepted 12 January 2011. Abstract. A dusty multi-ion plasma system consisting ...

  3. The dust-acoustic mode in two-temperature electron plasmas with ...

    Indian Academy of Sciences (India)

    as the collection of background plasma electrons and ions by dust grains, photoelectron emission, secondary .... where qd is the mean charges of the dust grains and Ij is the collection current of jth species (j = ec, eh, ..... hot electron components on the dusty grains, as it is more mobile when compared to cold electrons and ...

  4. Planar dust-acoustic waves in electron–positron–ion–dust plasmas ...

    Indian Academy of Sciences (India)

    2014-09-19

    Sep 19, 2014 ... Abstract. Propagation of small but finite nonlinear dust-acoustic solitary waves are investigated in a planar unmagnetized dusty plasma, which consists of electrons, positrons, ions and negatively charged dust particles with different sizes and masses. A Kadomtsev–Petviashvili (KP) equation is obtained by ...

  5. Dust-acoustic solitons in quantum plasma with kappa-distributed ions

    Indian Academy of Sciences (India)

    Abstract. Arbitrary amplitude dust-acoustic (DA) solitary waves in an unmagnetized and col- lisionless quantum dusty plasma comprising cold dust particles, kappa (κ)-distributed ions and degenerate electrons are investigated. The influence of suprathermality and quantum effects on the linear dispersion relation of DA ...

  6. Physics of Strongly Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kraeft, Wolf-Dietrich [Universitat Rostock (Germany)

    2007-07-15

    Strongly coupled plasmas (or non-ideal plasmas) are multi-component charged many-particle systems, in which the mean value of the potential energy of the system is of the same order as or even higher than the mean value of the kinetic energy. The constituents are electrons, ions, atoms and molecules. Dusty (or complex) plasmas contain still mesoscopic (multiply charged) particles. In such systems, the effects of strong coupling (non-ideality) lead to considerable deviations of physical properties from the corresponding properties of ideal plasmas, i.e., of plasmas in which the mean kinetic energy is essentially larger than the mean potential energy. For instance, bound state energies become density dependent and vanish at higher densities (Mott effect) due to the interaction of the pair with the surrounding particles. Non-ideal plasmas are of interest both for general scientific reasons (including, for example, astrophysical questions), and for technical applications such as inertially confined fusion. In spite of great efforts both experimentally and theoretically, satisfactory information on the physical properties of strongly coupled plasmas is not at hand for any temperature and density. For example, the theoretical description of non-ideal plasmas is possible only at low densities/high temperatures and at extremely high densities (high degeneracy). For intermediate degeneracy, however, numerical experiments have to fill the gap. Experiments are difficult in the region of 'warm dense matter'. The monograph tries to present the state of the art concerning both theoretical and experimental attempts. It mainly includes results of the work performed in famous Russian laboratories in recent decades. After outlining basic concepts (chapter 1), the generation of plasmas is considered (chapter 2, chapter 3). Questions of partial (chapter 4) and full ionization (chapter 5) are discussed including Mott transition and Wigner crystallization. Electrical and

  7. Ion firehose instability in a dusty plasma considering product-bi-kappa distributions for the plasma particles

    Energy Technology Data Exchange (ETDEWEB)

    Santos, M. S. dos, E-mail: michel.santos@iffarroupilha.edu.br [Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970, Porto Alegre, RS (Brazil); Instituto Federal de Educação, Ciência e Tecnologia Farroupilha, 98590-000, Santo Augusto, RS (Brazil); Ziebell, L. F., E-mail: luiz.ziebell@ufrgs.br; Gaelzer, R., E-mail: rudi.gaelzer@ufrgs.br [Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970, Porto Alegre, RS (Brazil)

    2016-01-15

    We study the dispersion relation for low frequency waves in the whistler mode propagating along the ambient magnetic field, considering ions and electrons with product-bi-kappa (PBK) velocity distributions and taking into account the presence of a population of dust particles. The results obtained by numerical analysis of the dispersion relation show that the decrease in the κ indexes in the ion PBK distribution contributes to the increase in magnitude of the growth rates of the ion firehose instability and the size of the region in wave number space where the instability occurs. It is also shown that the decrease in the κ indexes in the electron PBK distribution contribute to decrease in the growth rates of instability, despite the fact that the instability occurs due to the anisotropy in the ion distribution function. For most of the interval of κ values which has been investigated, the ability of the non-thermal ions to increase the instability overcomes the tendency of decrease due to the non-thermal electron distribution, but for very small values of the kappa indexes the deleterious effect of the non-thermal electrons tends to overcome the effect due to the non-thermal ion distribution.

  8. Infrared study of new star cluster candidates associated to dusty globules

    Science.gov (United States)

    Soto King, P.; Barbá, R.; Roman-Lopes, A.; Jaque, M.; Firpo, V.; Nilo, J. L.; Soto, M.; Minniti, D.

    2014-10-01

    We present results from a study of a sample of small star clusters associated to dusty globules and bright-rimmed clouds that have been observed under ESO/Chile public infrared survey Vista Variables in the Vía Láctea (VVV). In this short communication, we analyse the near-infrared properties of a set of four small clusters candidates associated to dark clouds. This sample of clusters associated to dusty globules are selected from the new VVV stellar cluster candidates developed by members of La Serena VVV Group (Barbá et al. 2014). Firstly, we are producing color-color and color-magnitude diagrams for both, cluster candidates and surrounding areas for comparison through PSF photometry. The cluster positions are determined from the morphology on the images and also from the comparison of the observed luminosity function for the cluster candidates and the surrounding star fields. Now, we are working in the procedures to establish the full sample of clusters to be analyzed and methods for subtraction of the star field contamination. These clusters associated to dusty globules are simple laboratories to study the star formation relatively free of the influence of large star-forming regions and populous clusters, and they will be compared with those clusters associated to bright-rimmed globules, which are influenced by the energetic action of nearby O and B massive stars.

  9. Unsteady MHD radiative flow and heat transfer of a dusty nanofluid over an exponentially stretching surface

    Directory of Open Access Journals (Sweden)

    N. Sandeep

    2016-03-01

    Full Text Available We analyzed the unsteady magnetohydrodynamic radiative flow and heat transfer characteristics of a dusty nanofluid over an exponentially permeable stretching surface in presence of volume fraction of dust and nano particles. We considered two types of nanofluids namely Cu-water and CuO-water embedded with conducting dust particles. The governing equations are transformed into nonlinear ordinary differential equations by using similarity transformation and solved numerically using Runge–Kutta based shooting technique. The effects of non-dimensional governing parameters namely magneticfield parameter, mass concentration of dust particles, fluid particle interaction parameter, volume fraction of dust particles, volume fraction of nano particles, unsteadiness parameter, exponential parameter, radiation parameter and suction/injection parameter on velocity profiles for fluid phase, dust phase and temperature profiles are discussed and presented through graphs. Also, friction factor and Nusselt numbers are discussed and presented for two dusty nanofluids separately. Comparisons of the present study were made with existing studies under some special assumptions. The present results have an excellent agreement with existing studies. Results indicated that the enhancement in fluid particle interaction increases the heat transfer rate and depreciates the wall friction. Also, radiation parameter has the tendency to increase the temperature profiles of the dusty nanofluid.

  10. SEM/EDS characterisation of dusty deposits in precipitation and assessment of their origin

    Directory of Open Access Journals (Sweden)

    Miloš Miler

    2014-07-01

    Full Text Available Detailed scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS analysis of dusty material in rainfall residue, deposited and collected on February 19th 2014 in Ljubljana, was carried out with the intention to characterise it according to its chemical and mineral composition and to assess its origin. The material consists of poorly sorted and sharp-edged particles of mostly very fine-grained silt and clay fractions, which is consistent with long-range aerial transport. Particles are represented by illite, chlorite and kaolinite group clay minerals, quartz, feldspars, carbonates, accessory minerals and secondary Fe-oxy-hydroxide minerals. Quantities of minerals and illite/ kaolinite ratio (4.5 correspond to dusts in rainfall residues originating from Moroccan Atlas, while chlorite/kaolinite ratio (2.8 agrees better with dust from central Libya. The element ratios Al/Si, Ca/Al, K/Ca, Mg/Al, Fe/Al and (Ca+Mg/Fe in the studied dusty deposit are in good agreement with ratios in dusts from rainfall residues originating from Morocco and northern Mauritania. This was also confirmed by the trajectories of cloud movement that caused precipitation with dusty deposit, although the back trajectory HYSPLIT simulation of air masses indicated northern Mauritania, central Niger, southern Algeria, southwestern and central Libya as the most possible source regions.

  11. Dippers and dusty disc edges: new diagnostics and comparison to model predictions

    Science.gov (United States)

    Bodman, Eva H. L.; Quillen, Alice C.; Ansdell, Megan; Hippke, Michael; Boyajian, Tabetha S.; Mamajek, Eric E.; Blackman, Eric G.; Rizzuto, Aaron; Kastner, Joel H.

    2017-09-01

    We revisit the nature of large dips in flux from extinction by dusty circumstellar material that is observed by Kepler for many young stars in the Upper Sco and ρ Oph star formation regions. These young, low-mass 'dipper' stars are known to have low accretion rates and primarily host moderately evolved dusty circumstellar discs. Young low-mass stars often exhibit rotating starspots that cause quasi-periodic photometric variations. We found no evidence for periods associated with the dips that are different from the starspot rotation period in spectrograms constructed from the light curves. The material causing the dips in most of these light curves must be approximately corotating with the star. We find that disc temperatures computed at the disc corotation radius are cool enough that dust should not sublime. Crude estimates for stellar magnetic field strengths and accretion rates are consistent with magnetospheric truncation near the corotation radius. Magnetospheric truncation models can explain why the dips are associated with material near corotation and how dusty material is lifted out of the mid-plane to obscure the star that would account for the large fraction of young low-mass stars that are dippers. We propose that variations in disc orientation angle, stellar magnetic field dipole tilt axis and disc accretion rate are underlying parameters accounting for differences in the dipper light curves.

  12. Thermal Marangoni convection in two-phase flow of dusty Casson fluid

    Directory of Open Access Journals (Sweden)

    B. Mahanthesh

    2018-03-01

    Full Text Available This paper deals with the thermal Marangoni convection effects in magneto-Casson liquid flow through suspension of dust particles. The transpiration cooling aspect is accounted. The surface tension is assumed to be fluctuating linearly with temperature. The fluid and dust particle’s temperature of the interface is chosen as a quadratic function of interface arc length. The governing problem is modelled by conservation laws of mass, momentum and energy for fluid and dust particle phase. Stretching transformation technique is utilized to form ordinary differential equations from the partial differential equations. Later, the numerical solutions based on Runge-Kutta-Fehlberg method are established. The momentum and heat transport distributions are focused on the outcome of distinct governing parameters. The results of Nusselt number is also presented and discussed. It is established that the heat transfer rate is higher in the case of dusty non-Newtonian fluid than dusty Newtonian fluid. The rate of heat transfer can be enhanced by suspending dust particles in a base liquid. Keywords: Marangoni convection, Dusty fluid, Casson fluid, Two-phase flow, Runge-Kutta-Fehlberg method

  13. Gas, Dust, and Quenching of Dusty Galaxies in the Early Universe

    Science.gov (United States)

    Spilker, Justin Scott

    In this dissertation, I study various aspects related to the gas and star formation in dusty star-forming galaxies in the distant universe. My dissertation is heavily based on observations made by the Atacama Large Millimeter/submillimeter Array (ALMA), observing a sample of gravitationally lensed high-redshift dusty galaxies originally discovered by the South Pole Telescope (SPT). In addition to the introductions to the individual chapters, Chapter 1 provides a broader background to the study of these objects and places them in the overall context of galaxy evolution. In Chapter 2 I describe a technique designed to search for faint molecular lines in the spectrum of high-redshift dusty galaxies. The brightest molecular lines in the spectra of these objects are due to carbon monoxide, but a host of other species are present in the interstellar media. These other molecules trace gas of a wide range of temperatures and densities, but are generally ten times fainter than the brighter CO lines. I detected several other molecular lines, and used them to characterize the conditions of the interstellar gas. This work was published in Spilker et al. (2014). In Chapter 3, I describe a technique for modeling the effects of gravitational lensing which is optimized for data from interferometers such as ALMA. Using these models and data for a large sample of objects from ALMA, I studied the intrinsic properties of the sample such as the source sizes and luminosities. I used these intrinsic properties to revisit topics from the literature which benefit from the additional size information I determined. This work was published in Spilker et al. (2016). In Chapter 4, I use the modeling technique I developed to investigate the relationship between the star formation and the cold molecular gas from which stars form in two objects selected from the SPT sample. Using the models of the source, I was able to determine the mass of molecular gas in these objects using several independent

  14. Monitoring non-thermal plasma processes for nanoparticle synthesis

    Science.gov (United States)

    Mangolini, Lorenzo

    2017-09-01

    Process characterization tools have played a crucial role in the investigation of dusty plasmas. The presence of dust in certain non-thermal plasma processes was first detected by laser light scattering measurements. Techniques like laser induced particle explosive evaporation and ion mass spectrometry have provided the experimental evidence necessary for the development of the theory of particle nucleation in silane-containing non-thermal plasmas. This review provides first a summary of these early efforts, and then discusses recent investigations using in situ characterization techniques to understand the interaction between nanoparticles and plasmas. The advancement of such monitoring techniques is necessary to fully develop the potential of non-thermal plasmas as unique materials synthesis and processing platforms. At the same time, the strong coupling between materials and plasma properties suggest that it is also necessary to advance techniques for the measurement of plasma properties while in presence of dust. Recent progress in this area will be discussed.

  15. Non-equilibrium effects in the processing of materials using plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mangolini, Lorenzo [Univ. of California, Riverside, CA (United States)

    2016-06-02

    We have provided experimental evidence that nanoparticles in plasma are heated to temperatures that are significantly higher than that of the background gas. This result gives experimental confirmation to a number of theoretical/computational studies that predicted this behavior. Moreover, this study has provided with the first measurement of the temperature of nanoparticles in a processing dusty plasma, i.e. under conditions that are relevant for the growth and modification of nanopowders.

  16. New taxonomic and faunistic data on the dusty wings from Senegal (Insecta, Neuroptera, Coniopterygidae

    Directory of Open Access Journals (Sweden)

    Monserrat, V. J.

    2006-06-01

    Full Text Available New data on the taxonomy, biology, distribution and/or morphology of eight dusty wing species from Senegal are given. None had previously been recorded from this country. In this African area (where the Afrotropical and Palaearctic Biogeographical Regions contact a great number of species can be found, mostly afrotropical elements, but also some palaearctic elements and species with a wide circumsaharan distribution are present. A great faunistic similarity between the Senegalese Fauna and the SW Arabian Peninsula fauna is noted, and both areas show many common elements present in the East-West Afrotropical northern borders. Some new synonymies are proposed as follow: Aleuropteryx felix Meinander, 1977 = (Aleuropteryx teleki Sziráki, 1990 = Aleuropteryx transvaalensis Meinander, 1998, Aleuropteryx Arabica Meinander, 1977 = (Aleuropteryx cruciata Sziráki, 1990, Coniocompsa silvestriana Enderlein, 1914 = (Coniocompsa arabica Sziráki, 1992 = Coniocompsa fimbrata Tjeder, 1957, Coniopteryx (Coniopteryx greenpeace Monserrat, 1995 = (Coniopteryx (Coniopteryx sclerotica Meinander, 1998, Coniopteryx (Xeroconiopteryx triantennata Monserrat, 1995 = (Coniopteryx (Xeroconiopteryx sestertia Meinander, 1998 and Nimboa marroquina Monserrat, 1985 = (Nimboa manselli Meinander, 1998. Also a replacement name: Coniopteryx (Xeroconiopteryx conviventibus nom. nov. is proposed for Coniopteryx (Xeroconiopteryx furcata Meinander, 1998 nec Coniopteryx (Scotoconiopteryx furcata Meinander, 1983.

    Se anotan nuevos datos sobre la taxonomía, biología, distribución y /o morfología de ocho especies de coniopterígidos recolectados en Senegal. Ninguna de ellas había sido citada en este país. Al igual que ocurre en el SO de la Península Arábiga, esta zona del Continente Africano (donde confluyen las Regiones Biogeográficas Afrotropical y Pale

  17. Unsteady hydromagnetic flow of dusty fluid and heat transfer over a vertical stretching sheet with thermal radiation

    Energy Technology Data Exchange (ETDEWEB)

    Isa, Sharena Mohamad; Ali, Anati [Department of Mathematical Sciences, Faculty of Science Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor, Malaysia sharena-ina@yahoo.com, anati@utm.my (Malaysia)

    2015-10-22

    In this paper, the hydromagnetic flow of dusty fluid over a vertical stretching sheet with thermal radiation is investigated. The governing partial differential equations are reduced to nonlinear ordinary differential equations using similarity transformation. These nonlinear ordinary differential equations are solved numerically using Runge-Kutta Fehlberg fourth-fifth order method (RKF45 Method). The behavior of velocity and temperature profiles of hydromagnetic fluid flow of dusty fluid is analyzed and discussed for different parameters of interest such as unsteady parameter, fluid-particle interaction parameter, the magnetic parameter, radiation parameter and Prandtl number on the flow.

  18. Stochastic heating of dust particles in complex plasmas as an energetic instability of a harmonic oscillator with random frequency

    Energy Technology Data Exchange (ETDEWEB)

    Marmolino, Ciro [Dipartimento di Scienze e Tecnologie dell' Ambiente e del Territorio-DiSTAT, Universita del Molise, Contrada Fonte Lappone, I-86090 Pesche (Italy)

    2011-10-15

    The paper describes the occurrence of stochastic heating of dust particles in dusty plasmas as an energy instability due to the correlations between dust grain charge and electric field fluctuations. The possibility that the mean energy (''temperature'') of dust particles can grow in time has been found both from the self-consistent kinetic description of dusty plasmas taking into account charge fluctuations [U. de Angelis, A. V. Ivlev, V. N. Tsytovich, and G. E. Morfill, Phys. Plasmas 12(5), 052301 (2005)] and from a Fokker-Planck approach to systems with variable charge [A. V. Ivlev, S. K. Zhdanov, B. A. Klumov, and G. E. Morfill, Phys. Plasmas 12(9), 092104 (2005)]. Here, a different derivation is given by using the mathematical techniques of the so called multiplicative stochastic differential equations. Both cases of ''fast'' and ''slow'' fluctuations are discussed.

  19. Principles of Transport in Multicomponent Plasmas

    Science.gov (United States)

    Kaganovich, Igor D.; Franklin, Raoul N.; Demidov, Vladimir I.

    The main principles of transport in multicomponent plasmas are described. Because the bulk plasma is charged positively to keep electrons together with positive ions, negative ions are confined by electrostatic fields inside the plasma and they flow from the plasma periphery toward the center. It is shown that the flow velocity of negative ions is a nonlinear function of the negative ion density. Increasing the negative ion density makes the electron density profile flatter and leads to a decrease of the electric field. Such a nonlinear dependence of the negative ion flow velocity on their density results in the formation of steep gradients of negative ion density, or negative ion fronts. Addition of negative ions makes the plasma afterglow a complex process as well. Typically, two stages of afterglow appear. In the first stage, the negative ions are trapped inside the plasma and only electrons and positive ions can reach the walls. However, at a later time, electrons quickly leave the plasma, and the second stage of afterglow begins, in which electrons are totally absent and an ion-ion plasma forms. During this stage, only the negative and positive ions contribute to the wall fluxes. The complex structure of the radio frequency sheath in strongly electronegative gases is also reviewed. Similar phenomena are observed in dusty plasmas. A possible relevance to ball lightning is discussed.

  20. Bifurcation of space-charge wave in a plasma waveguide including the wake potential effect

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung-Jae [Department of Physics and Research Institute for Natural Sciences, Hanyang University, Seoul 04763 (Korea, Republic of); Jung, Young-Dae, E-mail: ydjung@hanyang.ac.kr [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 15588, South Korea and Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180-3590 (United States)

    2016-09-15

    The wake potential effects on the propagation of the space-charge dust ion-acoustic wave are investigated in a cylindrically bounded dusty plasma with the ion flow. The results show that the wake potential would generate the double frequency modes in a cylindrically bounded dusty plasma. It is found that the upper mode of the wave frequency with the root of higher-order is smaller than that with the root of lower-order in intermediate wave number domains. However, the lower mode of the scaled wave frequency with the root of higher-order is found to be greater than that with the root of lower-order. It is found that the influence in the order of the root of the Bessel function on the wave frequency of the space-charge dust-ion-acoustic wave in a cylindrically confined dusty plasma decreases with an increase in the propagation wave number. It is also found that the double frequency modes increase with increasing Mach number due to the ion flow in a cylindrical dusty plasma. In addition, it is found that the upper mode of the group velocity decreases with an increase in the scaled radius of the plasma cylinder. However, it is shown that the lower mode of the scaled group velocity of the space-charge dust ion acoustic wave increases with an increase in the radius of the plasma cylinder. The variation of the space-charge dust-ion-acoustic wave due to the wake potential and geometric effects is also discussed.

  1. STELLAR MEMBERSHIP AND DUSTY DEBRIS DISKS IN THE α PERSEI CLUSTER

    International Nuclear Information System (INIS)

    Zuckerman, B.; Melis, Carl; Rhee, Joseph H.; Schneider, Adam; Song, Inseok

    2012-01-01

    Because of its proximity to the Galactic plane, reliable identification of members of the α Persei cluster is often problematic. Based primarily on membership evaluations contained in six published papers, we constructed a mostly complete list of high-fidelity members of spectral type G and earlier that lie within 3 arc degrees of the cluster center. α Persei was the one nearby, rich, young open cluster not surveyed with the Spitzer Space Telescope. We examined the first and final data releases of the Wide-field Infrared Survey Explorer and found 11, or perhaps 12, α Per cluster members that have excess mid-infrared emission above the stellar photosphere attributable to an orbiting dusty debris disk. The most unusual of these is V488 Per, a K-type star with an excess IR luminosity 16% (or more) of the stellar luminosity; this is a larger excess fraction than that of any other known dusty main-sequence star. Much of the dust that orbits V488 Per is at a temperature of ∼800 K; if these grains radiate like blackbodies, then they lie only ∼0.06 AU from the star. The dust is probably the aftermath of a collision of two planetary embryos or planets with small semimajor axes; such orbital radii are similar to those of many of the transiting planets discovered by the Kepler satellite.

  2. Modification of TOUGH2 to Include the Dusty Gas Model for Gas Diffusion; TOPICAL

    International Nuclear Information System (INIS)

    WEBB, STEPHEN W.

    2001-01-01

    The GEO-SEQ Project is investigating methods for geological sequestration of CO(sub 2). This project, which is directed by LBNL and includes a number of other industrial, university, and national laboratory partners, is evaluating computer simulation methods including TOUGH2 for this problem. The TOUGH2 code, which is a widely used code for flow and transport in porous and fractured media, includes simplified methods for gas diffusion based on a direct application of Fick's law. As shown by Webb (1998) and others, the Dusty Gas Model (DGM) is better than Fick's Law for modeling gas-phase diffusion in porous media. In order to improve gas-phase diffusion modeling for the GEO-SEQ Project, the EOS7R module in the TOUGH2 code has been modified to include the Dusty Gas Model as documented in this report. In addition, the liquid diffusion model has been changed from a mass-based formulation to a mole-based model. Modifications for separate and coupled diffusion in the gas and liquid phases have also been completed. The results from the DGM are compared to the Fick's law behavior for TCE and PCE diffusion across a capillary fringe. The differences are small due to the relatively high permeability (k= 10(sup -11) m(sup 2)) of the problem and the small mole fraction of the gases. Additional comparisons for lower permeabilities and higher mole fractions may be useful

  3. Thermal Marangoni convection in two-phase flow of dusty Casson fluid

    Science.gov (United States)

    Mahanthesh, B.; Gireesha, B. J.

    2018-03-01

    This paper deals with the thermal Marangoni convection effects in magneto-Casson liquid flow through suspension of dust particles. The transpiration cooling aspect is accounted. The surface tension is assumed to be fluctuating linearly with temperature. The fluid and dust particle's temperature of the interface is chosen as a quadratic function of interface arc length. The governing problem is modelled by conservation laws of mass, momentum and energy for fluid and dust particle phase. Stretching transformation technique is utilized to form ordinary differential equations from the partial differential equations. Later, the numerical solutions based on Runge-Kutta-Fehlberg method are established. The momentum and heat transport distributions are focused on the outcome of distinct governing parameters. The results of Nusselt number is also presented and discussed. It is established that the heat transfer rate is higher in the case of dusty non-Newtonian fluid than dusty Newtonian fluid. The rate of heat transfer can be enhanced by suspending dust particles in a base liquid.

  4. A dusty ringlet with connections to both Prometheus and the F ring

    Science.gov (United States)

    Hedman, Matthew M.; Carter, Brian

    2016-05-01

    Prometheus is a small satellite of Saturn that orbits between the planet's main rings and the narrow and dusty F ring. Prometheus' complex interactions with the F-ring material have been investigated in some detail using data from the Cassini and Voyager spacecraft, but the moon's influences on other nearby dusty rings are still largely unexplored. Here we examine a very faint ringlet that can be seen in high-phase images of the region around Prometheus' orbit taken by the Cassini spacecraft. These data reveal that the mean radius of this ringlet is close to Prometheus' semi-major axis, suggesting that it consists of material co-orbiting with that moon. However, images taken at different times and longitudes also reveal that the ringlet is eccentric, and its apsidal precession rate is not that expected for material close to Prometheus' orbit (semi-major axis of 139,380 km). Instead, the ringlet appears to be precessing at the same rate as the F-ring (mean radius around 140,200 km). The structure and dynamics of this ringlet therefore probably involve interactions with both Prometheus and the F ring.

  5. Marangoni convection radiative flow of dusty nanoliquid with exponential space dependent heat source

    Directory of Open Access Journals (Sweden)

    Basavarajappa Mahanthesh

    2017-12-01

    Full Text Available The flow of liquids submerged with nanoparticles is of significance to industrial applications, specifically in nuclear reactors and the cooling of nuclear systems to improve energy efficiency. The application of nanofluids in water-cooled nuclear systems can result in a significant improvement of their economic performance and/or safety margins. Therefore, in this paper, Marangoni thermal convective boundary layer dusty nanoliquid flow across a flat surface in the presence of solar radiation is studied. A two phase dusty liquid model is considered. Unlike classical temperature-dependent heat source effects, an exponential space-dependent heat source aspect is considered. Stretching variables are utilized to transform the prevailing partial differential system into a nonlinear ordinary differential system, which is then solved numerically via the Runge-Kutta-Fehlberg approach coupled with a shooting technique. The roles of physical parameters are focused in momentum and heat transport distributions. Graphical illustrations are also used to consider local and average Nusselt numbers. We examined the results under both linear and quadratic variation of the surface temperature. Our simulations established that the impact of Marangoni flow is useful for an enhancement of the heat transfer rate.

  6. A dusty star-forming galaxy at z = 6 revealed by strong gravitational lensing

    Science.gov (United States)

    Zavala, Jorge A.; Montaña, Alfredo; Hughes, David H.; Yun, Min S.; Ivison, R. J.; Valiante, Elisabetta; Wilner, David; Spilker, Justin; Aretxaga, Itziar; Eales, Stephen; Avila-Reese, Vladimir; Chávez, Miguel; Cooray, Asantha; Dannerbauer, Helmut; Dunlop, James S.; Dunne, Loretta; Gómez-Ruiz, Arturo I.; Michałowski, Michał J.; Narayanan, Gopal; Nayyeri, Hooshang; Oteo, Ivan; Rosa González, Daniel; Sánchez-Argüelles, David; Schloerb, F. Peter; Serjeant, Stephen; Smith, Matthew W. L.; Terlevich, Elena; Vega, Olga; Villalba, Alan; van der Werf, Paul; Wilson, Grant W.; Zeballos, Milagros

    2018-01-01

    Since their discovery, submillimetre-selected galaxies1,2 have revolutionized the field of galaxy formation and evolution. From the hundreds of square degrees mapped at submillimetre wavelengths3-5, only a handful of sources have been confirmed to lie at z > 5 (refs 6-10) and only two at z ≥ 6 (refs 11,12). All of these submillimetre galaxies are rare examples of extreme starburst galaxies with star formation rates of ≳1,000 M⊙ yr-1 and therefore are not representative of the general population of dusty star-forming galaxies. Consequently, our understanding of the nature of these sources, at the earliest epochs, is still incomplete. Here, we report the spectroscopic identification of a gravitationally amplified (μ = 9.3 ± 1.0) dusty star-forming galaxy at z = 6.027. After correcting for gravitational lensing, we derive an intrinsic less-extreme star formation rate of 380 ± 50 M⊙ yr-1 for this source and find that its gas and dust properties are similar to those measured for local ultra luminous infrared galaxies, extending the local trends to a poorly explored territory in the early Universe. The star-formation efficiency of this galaxy is similar to those measured in its local analogues13, despite a 12 Gyr difference in cosmic time.

  7. Fundamentals of Plasma Physics

    Energy Technology Data Exchange (ETDEWEB)

    Cargill, P J [Imperial College School of Medicine (United Kingdom)

    2007-02-15

    The widespread importance of plasmas in many areas of contemporary physics makes good textbooks in the field that are both introductory and comprehensive invaluable. This new book by Paul Bellen from CalTech by and large meets these goals. It covers the traditional textbook topics such as particle orbits, the derivation of the MHD equations from Vlasov theory, cold and warm plasma waves, Landau damping, as well as in the later chapters less common subjects such as magnetic helicity, nonlinear processes and dusty plasmas. The book is clearly written, neatly presented, and each chapter has a number of exercises or problems at their end. The author has also thankfully steered clear of the pitfall of filling the book with his own research results. The preface notes that the book is designed to provide an introduction to plasma physics for final year undergraduate and post-graduate students. However, it is difficult to see many physics undergraduates now at UK universities getting to grips with much of the content since their mathematics is not of a high enough standard. Students in Applied Mathematics departments would certainly fare better. An additional problem for the beginner is that some of the chapters do not lead the reader gently into a subject, but begin with quite advanced concepts. Being a multi-disciplinary subject, beginners tend to find plasma physics quite hard enough even when done simply. For postgraduate students these criticisms fade away and this book provides an excellent introduction. More senior researchers should also enjoy the book, especially Chapters 11-17 where more advanced topics are discussed. I found myself continually comparing the book with my favourite text for many years, 'The Physics of Plasmas' by T J M Boyd and J J Sanderson, reissued by Cambridge University Press in 2003. Researchers would want both books on their shelves, both for the different ways basic plasma physics is covered, and the diversity of more advanced

  8. Fundamentals of Plasma Physics

    International Nuclear Information System (INIS)

    Cargill, P J

    2007-01-01

    The widespread importance of plasmas in many areas of contemporary physics makes good textbooks in the field that are both introductory and comprehensive invaluable. This new book by Paul Bellen from CalTech by and large meets these goals. It covers the traditional textbook topics such as particle orbits, the derivation of the MHD equations from Vlasov theory, cold and warm plasma waves, Landau damping, as well as in the later chapters less common subjects such as magnetic helicity, nonlinear processes and dusty plasmas. The book is clearly written, neatly presented, and each chapter has a number of exercises or problems at their end. The author has also thankfully steered clear of the pitfall of filling the book with his own research results. The preface notes that the book is designed to provide an introduction to plasma physics for final year undergraduate and post-graduate students. However, it is difficult to see many physics undergraduates now at UK universities getting to grips with much of the content since their mathematics is not of a high enough standard. Students in Applied Mathematics departments would certainly fare better. An additional problem for the beginner is that some of the chapters do not lead the reader gently into a subject, but begin with quite advanced concepts. Being a multi-disciplinary subject, beginners tend to find plasma physics quite hard enough even when done simply. For postgraduate students these criticisms fade away and this book provides an excellent introduction. More senior researchers should also enjoy the book, especially Chapters 11-17 where more advanced topics are discussed. I found myself continually comparing the book with my favourite text for many years, 'The Physics of Plasmas' by T J M Boyd and J J Sanderson, reissued by Cambridge University Press in 2003. Researchers would want both books on their shelves, both for the different ways basic plasma physics is covered, and the diversity of more advanced topics. For

  9. Proceedings of the second Asian Pacific plasma theory conference APPTC'97

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Yukihiro; Nakamura, Yuji; Hayashi, Takaya [eds.

    1998-08-01

    This issue is the proceedings of the second Asian Pacific Plasma Theory Conference (APPTC'97), which was held on September 24-26, 1997 at National Institute for Fusion Science (Toki, Japan) under the auspices of the Japan Society of Plasma Science and Nuclear Fusion Research and the National Institute of Fusion Science. A part of APPTC'97 was a joint session with Japan-Australia fusion theory workshop and US-Japan JIFT workshop on Theoretical Study for Helical Plasmas. The conference covers all plasma theory areas including magnetic confinement, inertial fusion, space plasmas, astrophysical plasma, industrial processing plasmas, and dusty plasma, etc. The 43 of the presented papers are indexed individually. (J.P.N.)

  10. Proceedings of the second Asian Pacific plasma theory conference APPTC'97

    International Nuclear Information System (INIS)

    Tomita, Yukihiro; Nakamura, Yuji; Hayashi, Takaya

    1998-08-01

    This issue is the proceedings of the second Asian Pacific Plasma Theory Conference (APPTC'97), which was held on September 24-26, 1997 at National Institute for Fusion Science (Toki, Japan) under the auspices of the Japan Society of Plasma Science and Nuclear Fusion Research and the National Institute of Fusion Science. A part of APPTC'97 was a joint session with Japan-Australia fusion theory workshop and US-Japan JIFT workshop on Theoretical Study for Helical Plasmas. The conference covers all plasma theory areas including magnetic confinement, inertial fusion, space plasmas, astrophysical plasma, industrial processing plasmas, and dusty plasma, etc. The 43 of the presented papers are indexed individually. (J.P.N.)

  11. Reversed Hall effect and plasma conductivity in the presence of charged impurities

    Science.gov (United States)

    Yaroshenko, V. V.; Lühr, H.

    2018-01-01

    The Hall conductivity of magnetized plasma can be strongly suppressed by the contribution of negatively charged particulates (referred further as "dust"). Once the charge density accumulated by the dust exceeds a certain threshold, the Hall component becomes negative, providing a reversal in the Hall current. Such an effect is unique for dust-loaded plasmas, and it can hardly be achieved in electronegative plasmas. Further growth of the dust density leads to an increase in both the absolute value of the Hall and Pedersen conductivities, while the field-aligned component is decreased. These modifications enhance the role of transverse electric currents and reduce the anisotropy of a magnetized plasma when loaded with charged impurities. The findings provide an important basis for studying the generation of electric currents and transport phenomena in magnetized plasma systems containing small charged particulates. They can be relevant for a wide range of applications from naturally occurring space plasmas in planetary magnetospheres and astrophysical objects to laboratory dusty plasmas (Magnetized Dusty Plasma Experiment) and to technological and fusion plasmas.

  12. Numerical Simulation of single-stage axial fan operation under dusty flow conditions

    Science.gov (United States)

    Minkov, L. L.; Pikushchak, E. V.

    2017-11-01

    Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

  13. Improving Galactic foregrounds with dusty, multiphase gas from GALFA-HI

    Science.gov (United States)

    Murray, Claire; Peek, Joshua

    2018-01-01

    Resolving the initial conditions for star formation and removing foregrounds from cosmological measurements both rely on precise accounting for the structure of multiphase, dusty interstellar gas in the Milky Way. Our aim is to differentiate between distinct thermal phases of Galactic HI and their dust-bearing properties. Using machine vision techniques, we autonomously decompose spectra from GALFA-HI at the Arecibo Observatory: the highest angular (4') and velocity resolution (0.18 km/s) large-area (13,000 deg^2) survey of 21 cm emission to date. We compute temperatures for millions of spectral features, and extract coherent structures corresponding to cold and warm HI. Via comparison with far infrared emission surveys, we analyze variations in dust reddening as a function of the cold gas fraction at high Galactic latitudes, and demonstrate how this effect can be used to improve the resolution and fidelity of standard dust reddening maps.

  14. Two-phase dusty fluid flow along a cone with variable properties

    Science.gov (United States)

    Siddiqa, Sadia; Begum, Naheed; Hossain, Md. Anwar; Mustafa, Naeem; Gorla, Rama Subba Reddy

    2017-05-01

    In this paper numerical solutions of a two-phase natural convection dusty fluid flow are presented. The two-phase particulate suspension is investigated along a vertical cone by keeping variable viscosity and thermal conductivity of the carrier phase. Comprehensive flow formations of the gas and particle phases are given with the aim to predict the behavior of heat transport across the heated cone. The influence of (1) air with particles, (2) water with particles and (3) oil with particles are shown on shear stress coefficient and heat transfer coefficient. It is recorded that sufficient increment in heat transport rate can be achieved by loading the dust particles in the air. Further, distribution of velocity and temperature of both the carrier phase and the particle phase are shown graphically for the pure fluid (air, water) as well as for the fluid with particles (air-metal and water-metal particle mixture).

  15. AGN Obscuration Through Dusty Infrared Dominated Flows. II. Multidimensional, Radiation-Hydrodynamics Modeling

    Science.gov (United States)

    Dorodnitsyn, Anton; Kallman, Tim; Bisno\\vatyiI-Kogan, Gennadyi

    2011-01-01

    We explore a detailed model in which the active galactic nucleus (AGN) obscuration results from the extinction of AGN radiation in a global ow driven by the pressure of infrared radiation on dust grains. We assume that external illumination by UV and soft X-rays of the dusty gas located at approximately 1pc away from the supermassive black hole is followed by a conversion of such radiation into IR. Using 2.5D, time-dependent radiation hydrodynamics simulations in a ux-limited di usion approximation we nd that the external illumination can support a geometrically thick obscuration via out ows driven by infrared radiation pressure in AGN with luminosities greater than 0:05 L(sub edd) and Compton optical depth, Tau(sub T) approx > & 1.

  16. A Chandra grating observation of the dusty Wolf-Rayet star WR 48a

    International Nuclear Information System (INIS)

    Zhekov, Svetozar A.; Gagné, Marc; Skinner, Stephen L.

    2014-01-01

    We present results of a Chandra High-Energy Transmission Grating (HETG) observation of the carbon-rich Wolf-Rayet (WR) star WR 48a. These are the first high-resolution spectra of this object in X-ray. Blueshifted centroids of the spectral lines of ∼ – 360 km s –1 and line widths of 1000-1500 km s –1 (FWHM) were deduced from the analysis of the line profiles of strong emission lines. The forbidden line of Si XIII is strong and not suppressed, indicating that the rarified 10-30 MK plasma forms far from strong sources of far-ultraviolet emission, most likely in a wind collision zone. Global spectral modeling showed that the X-ray spectrum of WR 48a suffered higher absorption in the 2012 October Chandra observation compared with a previous 2008 January XMM-Newton observation. The emission measure of the hot plasma in WR 48a decreased by a factor ∼3 over the same period of time. The most likely physical picture that emerges from the analysis of the available X-ray data is that of colliding stellar winds in a wide binary system with an elliptical orbit. We propose that the unseen secondary star in the system is another WR star or perhaps a luminous blue variable.

  17. A Chandra grating observation of the dusty Wolf-Rayet star WR 48a

    Energy Technology Data Exchange (ETDEWEB)

    Zhekov, Svetozar A. [Space Research and Technology Institute, Akad. G. Bonchev Str., bl.1, Sofia 1113 (Bulgaria); Gagné, Marc [Department of Geology and Astronomy, West Chester University, West Chester, PA 19383 (United States); Skinner, Stephen L., E-mail: szhekov@space.bas.bg, E-mail: mgagne@wcupa.edu, E-mail: stephen.skinner@colorado.edu [CASA, University of Colorado, Boulder, CO 80309 (United States)

    2014-04-10

    We present results of a Chandra High-Energy Transmission Grating (HETG) observation of the carbon-rich Wolf-Rayet (WR) star WR 48a. These are the first high-resolution spectra of this object in X-ray. Blueshifted centroids of the spectral lines of ∼ – 360 km s{sup –1} and line widths of 1000-1500 km s{sup –1} (FWHM) were deduced from the analysis of the line profiles of strong emission lines. The forbidden line of Si XIII is strong and not suppressed, indicating that the rarified 10-30 MK plasma forms far from strong sources of far-ultraviolet emission, most likely in a wind collision zone. Global spectral modeling showed that the X-ray spectrum of WR 48a suffered higher absorption in the 2012 October Chandra observation compared with a previous 2008 January XMM-Newton observation. The emission measure of the hot plasma in WR 48a decreased by a factor ∼3 over the same period of time. The most likely physical picture that emerges from the analysis of the available X-ray data is that of colliding stellar winds in a wide binary system with an elliptical orbit. We propose that the unseen secondary star in the system is another WR star or perhaps a luminous blue variable.

  18. FROM DUSTY FILAMENTS TO MASSIVE STARS: THE CASE OF NGC 7538 S

    Energy Technology Data Exchange (ETDEWEB)

    Naranjo-Romero, Raul; Zapata, Luis A.; Vazquez-Semadeni, Enrique [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Morelia 58090 (Mexico); Takahashi, Satoko [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Palau, Aina [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB-Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra (Spain); Schilke, Peter [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Strasse 77, D-50937 Koeln (Germany)

    2012-09-20

    We report on high-sensitivity and high angular resolution archival Submillimeter Array observations of the large ({approx}15,000 AU) putative circumstellar disk associated with the O-type protostar NGC 7538 S. Observations of the continuum resolve this putative circumstellar disk into five compact sources, with sizes {approx}3000 AU and masses {approx}10 M{sub Sun }. This confirms the results of recent millimeter observations made with CARMA/BIMA toward this object. However, we find that most of these compact sources eject collimated bipolar outflows, revealed by our silicon monoxide (SiO J = 5-4) observations, and confirm that these sources have a (proto)stellar nature. All outflows are perpendicular to the large and rotating dusty structure. We propose therefore that, rather than being a single massive circumstellar disk, NGC 7538 S could instead be a large and massive contracting or rotating filament that is fragmenting at scales of 0.1-0.01 pc to form several B-type stars, via the standard process involving outflows and disks. As in recent high spatial resolution studies of dusty filaments, our observations also suggest that thermal pressure does not seem to be sufficient to support the filament, so that either additional support needs to be invoked or else the filament must be in the process of collapsing. A smoothed particle hydrodynamics numerical simulation of the formation of a molecular cloud by converging warm neutral medium flows produces contracting filaments whose dimensions and spacings between the stars forming within them, as well as their column densities, strongly resemble those observed in the filament reported here.

  19. Are dusty galaxies blue? Insights on UV attenuation from dust-selected galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Casey, C. M.; Cooray, A. [Department of Physics and Astronomy, University of California, Irvine, Irvine, CA 92697 (United States); Scoville, N. Z. [California Institute of Technology, 1216 East California Boulevard, Pasadena, CA 91125 (United States); Sanders, D. B.; Lee, N. [Institute for Astronomy, University of Hawai' i, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Finkelstein, S. L. [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Capak, P. [Spitzer Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Conley, A. [Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States); De Zotti, G. [Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 2, I-35122 Padova (Italy); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Fu, H. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242 (United States); Le Floc' h, E. [CEA-Saclay, Orme des Merisiers, bât. 709, F-91191 Gif-sur-Yvette Cedex (France); Ilbert, O. [Aix Marseille Université, CNRS, Laboratoire d' Astrophysique de marseille, UMR 7326, F-13388 Marseille (France); Ivison, R. J. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Takeuchi, T. T. [Nagoya University, Division of Particle and Astrophysical Science, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    2014-12-01

    Galaxies' rest-frame ultraviolet (UV) properties are often used to directly infer the degree to which dust obscuration affects the measurement of star formation rates (SFRs). While much recent work has focused on calibrating dust attenuation in galaxies selected at rest-frame ultraviolet wavelengths, locally and at high-z, here we investigate attenuation in dusty, star forming galaxies (DSFGs) selected at far-infrared wavelengths. By combining multiwavelength coverage across 0.15-500 μm in the COSMOS field, in particular making use of Herschel imaging, and a rich data set on local galaxies, we find an empirical variation in the relationship between the rest-frame UV slope (β) and the ratio of infrared-to-ultraviolet emission (L {sub IR}/L {sub UV} ≡ IRX) as a function of infrared luminosity, or total SFR. Both locally and at high-z, galaxies above SFR ≳ 50 M {sub ☉} yr{sup –1} deviate from the nominal IRX-β relation toward bluer colors by a factor proportional to their increasing IR luminosity. We also estimate contamination rates of DSFGs on high-z dropout searches of <<1% at z ≲ 4-10, providing independent verification that contamination from very dusty foreground galaxies is low in Lyman-break galaxy searches. Overall, our results are consistent with the physical interpretation that DSFGs, e.g., galaxies with >50 M {sub ☉} yr{sup –1}, are dominated at all epochs by short-lived, extreme burst events, producing many young O and B stars that are primarily, yet not entirely, enshrouded in thick dust cocoons. The blue rest-frame UV slopes of DSFGs are inconsistent with the suggestion that most DSFGs at z ∼ 2 exhibit steady-state star formation in secular disks.

  20. Dust-Lower-Hybrid Surface Waves in Classical and Degenerate Plasmas

    International Nuclear Information System (INIS)

    Ayub, M.; Shah, H.A.; Qureshi, M.N.S.; Salimullah, M.

    2013-01-01

    The dispersion relation for general dust low frequency electrostatic surface waves propagating on an interface between a magnetized dusty plasma region and a vacuum is derived by using specular reflection boundary conditions both in classical and quantum regimes. The frequency limit ω ≪ ω ci ≪ ω ce is considered and the dispersion relation for the Dust-Lower-Hybrid Surface Waves (DLHSW's) is derived for both classical and quantum plasma half-space and analyzed numerically. It is shown that the wave behavior changes as the quantum nature of the problem is considered. (physics of gases, plasmas, and electric discharges)

  1. Partially ionized plasmas including the third symposium on uranium plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, M. [ed.

    1976-09-01

    Separate abstracts are included for 28 papers on electrically generated plasmas, fission generated plasmas, nuclear pumped lasers, gaseous fuel reactor research, and applications. Five papers have been previously abstracted and included in ERA.

  2. The effects of variable dust size and charge on dust acoustic waves propagating in a hybrid Cairns–Tsallis complex plasma

    Science.gov (United States)

    El-Taibany, W. F.; El-Siragy, N. M.; Behery, E. E.; Elbendary, A. A.; Taha, R. M.

    2018-05-01

    The propagation characteristics of dust acoustic waves (DAWs) in a dusty plasma consisting of variable size dust grains, hybrid Cairns-Tsallis-distributed electrons, and nonthermal ions are studied. The charging of the dust grains is described by the orbital-motion-limited theory and the size of the dust grains obeys the power law dust size distribution. To describe the nonlinear propagation of the DAWs, a Zakharov-Kuznetsov equation is derived using a reductive perturbation method. It is found that the nonthermal and nonextensive parameters influence the main properties of DAWs. Moreover, our results reveal that the rarefactive waves can propagate mainly in the proposed plasma model while compressive waves can be detected for a very small range of the distribution parameters of plasma species, and the DAWs are faster and wider for smaller size dust grains. Applications of the present results to dusty plasma observations are briefly discussed.

  3. Effect of dust particle polarization on scattering processes in complex plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kodanova, S. K.; Ramazanov, T. S.; Bastykova, N. Kh.; Moldabekov, Zh. A. [Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Str., 050040 Almaty (Kazakhstan)

    2015-06-15

    Screened interaction potentials in dusty plasmas taking into account the polarization of dust particles have been obtained. On the basis of screened potentials scattering processes for ion-dust particle and dust particle-dust particle pairs have been studied. In particular, the scattering cross section is considered. The scattering processes for which the dust grain polarization is unimportant have been found. The effect of zero angle dust particle-dust particle scattering is predicted.

  4. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1989-08-01

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  5. The progenitors of local ultra-massive galaxies across cosmic time: from dusty star-bursting to quiescent stellar populations

    Energy Technology Data Exchange (ETDEWEB)

    Marchesini, Danilo; Marsan, Cemile Z. [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Muzzin, Adam; Franx, Marijn [Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden (Netherlands); Stefanon, Mauro [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States); Brammer, Gabriel G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Vulcani, Benedetta [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, University of Tokyo, Kashiwa 277-8582 (Japan); Fynbo, J. P. U.; Milvang-Jensen, Bo [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Dunlop, James S.; Buitrago, Fernando [SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom)

    2014-10-10

    Using the UltraVISTA catalogs, we investigate the evolution in the 11.4 Gyr since z = 3 of the progenitors of local ultra-massive galaxies (log (M {sub star}/M {sub ☉}) ≈ 11.8; UMGs), providing a complete and consistent picture of how the most massive galaxies at z = 0 have assembled. By selecting the progenitors with a semi-empirical approach using abundance matching, we infer a growth in stellar mass of 0.56{sub −0.25}{sup +0.35} dex, 0.45{sub −0.20}{sup +0.16} dex, and 0.27{sub −0.12}{sup +0.08} dex from z = 3, z = 2, and z = 1, respectively, to z = 0. At z < 1, the progenitors of UMGs constitute a homogeneous population of only quiescent galaxies with old stellar populations. At z > 1, the contribution from star-forming galaxies progressively increases, with the progenitors at 2 < z < 3 being dominated by massive (M {sub star} ≈ 2 × 10{sup 11} M {sub ☉}), dusty (A {sub V} ∼ 1-2.2 mag), star-forming (SFR ∼ 100-400 M {sub ☉} yr{sup –1}) galaxies with a large range in stellar ages. At z = 2.75, ∼15% of the progenitors are quiescent, with properties typical of post-starburst galaxies with little dust extinction and strong Balmer break, and showing a large scatter in color. Our findings indicate that at least half of the stellar content of local UMGs was assembled at z > 1, whereas the remaining was assembled via merging from z ∼ 1 to the present. Most of the quenching of the star-forming progenitors happened between z = 2.75 and z = 1.25, in good agreement with the typical formation redshift and scatter in age of z = 0 UMGs as derived from their fossil records. The progenitors of local UMGs, including the star-forming ones, never lived on the blue cloud since z = 3. We propose an alternative path for the formation of local UMGs that refines previously proposed pictures and that is fully consistent with our findings.

  6. Multi-scale three-dimensional characterization of iron particles in dusty olivine: Implications for paleomagnetism of chondritic meteorites

    DEFF Research Database (Denmark)

    Einsle, Joshua F.; Harrison, Richard J.; Kasama, Takeshi

    2016-01-01

    Dusty olivine (olivine containing multiple sub-micrometer inclusions of metallic iron) in chondritic meteorites is considered an ideal carrier of paleomagnetic remanence, capable of maintaining a faithful record of pre-accretionary magnetization acquired during chondrule formation. Here we show how......-dimensional (3D) volume reconstruction of a dusty olivine grain, obtained by selective milling through a region of interest in a series of sequential 20 nm slices, which are then imaged using scanning electron microscopy. The data provide a quantitative description of the iron particle ensemble, including...... axes of the particles and the remanence vector imparted in different fields. Although the orientation of the vortex core is determined largely by the ellipsoidal geometry (i.e., parallel to the major axis for prolate ellipsoids and parallel to the minor axis for oblate ellipsoids), the core...

  7. Influences of chemical reaction and wall properties on MHD Peristaltic transport of a Dusty fluid with Heat and Mass transfer

    Directory of Open Access Journals (Sweden)

    R. Muthuraj

    2016-03-01

    Full Text Available The influence of elasticity of flexible walls on peristaltic transport of a dusty fluid with heat and mass transfer in a horizontal channel in the presence of chemical reaction has been investigated under long wavelength approximation. Expressions have been constructed for stream function, temperature and concentration by using perturbation technique. The effects of various parameters on heat and mass transfer characteristics of the flow are discussed through graphs.

  8. Variable charge dust acoustic solitary waves in a dusty plasma with a q-nonextensive electron velocity distribution

    International Nuclear Information System (INIS)

    Amour, Rabia; Tribeche, Mouloud

    2010-01-01

    A first theoretical work is presented to study variable charge dust acoustic solitons within the theoretical framework of the Tsallis statistical mechanics. Our results reveal that the spatial patterns of the variable charge solitary wave are significantly modified by electron nonextensive effects. In particular, it may be noted that for -1 d becomes more negative and the dust grains localization (accumulation) less pronounced. The electrons are locally expelled and pushed out of the region of the soliton's localization. This electron depletion becomes less effective as the electrons evolve far away from their thermal equilibrium. The case q>1 provides qualitatively opposite results: electron nonextensivity makes the solitary structure more spiky. Our results should help in providing a good fit between theoretical and experimental results.

  9. Collisionless ion acoustic shocks in a negative-ion plasma

    International Nuclear Information System (INIS)

    Sheridan, T.E.

    1999-01-01

    Plasmas containing positive ions and electrons together with an additional negative component (e.g. negative ions or particulates) are of interest in subfields of plasma physics ranging from basic plasma physics (solitons and shocks, dusty plasmas) to ionospheric and space plasmas to plasma processing (electronegative discharges and particulate contamination). Such plasmas support two modes of the ion acoustic wave, a 'slow' mode where positive ions, negative ions and electrons oscillate in phase, and a 'fast' mode where negative ions oscillate out of phase with the other two components. When nonlinear steepening is considered, the fast wave may form a negative-potential solitary wave (NPSW), which, with the addition of dissipation (e.g. ion reflection, collisions, turbulence, electron Landau damping), will either disperse, or, more interestingly, form a shock. Recently, two experiments on the formation of shocks in a Q-machine plasma with negative ions have been reported. A low-temperature, negative-ion component was created when electrons attached to added SF 6 molecules. In such a plasma, the electron and positive ion temperatures are comparable (∼ 0.2 eV), so that when the negative ion concentration is small (< 50%), ion waves are strongly Landau damped since their phase velocity is comparable to the positive ion thermal velocity. However, a large negative ion concentration increases the phase velocity to a point where damping is weak. Conditions are then right for the formation of a shock. We have simulated shock formation in such a plasma

  10. THE LINK BETWEEN PLANETARY SYSTEMS, DUSTY WHITE DWARFS, AND METAL-POLLUTED WHITE DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Debes, John H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Walsh, Kevin J. [Southwest Research Institute, Boulder, CO (United States); Stark, Christopher [Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015 (United States)

    2012-03-10

    It has long been suspected that metal-polluted white dwarfs (types DAZ, DBZ, and DZ) and white dwarfs with dusty disks possess planetary systems, but a specific physical mechanism by which planetesimals are perturbed close to a white dwarf has not yet been fully posited. In this paper, we demonstrate that mass loss from a central star during post-main-sequence evolution can sweep planetesimals into interior mean motion resonances with a single giant planet. These planetesimals are slowly removed through chaotic excursions of eccentricity that in time create radial orbits capable of tidally disrupting the planetesimal. Numerical N-body simulations of the solar system show that a sufficient number of planetesimals are perturbed to explain white dwarfs with both dust and metal pollution, provided other white dwarfs have more massive relic asteroid belts. Our scenario requires only one Jupiter-sized planet and a sufficient number of asteroids near its 2:1 interior mean motion resonance. Finally, we show that once a planetesimal is perturbed into a tidal crossing orbit, it will become disrupted after the first pass of the white dwarf, where a highly eccentric stream of debris forms the main reservoir for dust-producing collisions. These simulations, in concert with observations of white dwarfs, place interesting limits on the frequency of planetary systems around main-sequence stars, the frequency of planetesimal belts, and the probability that dust may obscure future terrestrial planet finding missions.

  11. Theoretical Studies of Starburst Infrared Emission: Luminosity Indicators in Dusty Photoionized Environments

    Science.gov (United States)

    Bottorff, Mark; LaMothe, Joseph; Momjian, Emmanuel; Verner, Ekaterina; Vinkovic, Dejan; Ferland, Gary J.

    1998-01-01

    The luminosity of the central source in ionizing radiation is an essential parameter in a photoionized environment and is one of the most fundamental physical quantities one can measure. We outline a method of determining the luminosity for any emission-line region using only infrared data. In dusty environments, grains compete with hydrogen in absorbing continuum radiation. Grains produce infrared emission, and hydrogen produces recombination lines. We have computed a very large variety of photoionization models, using ranges of abundances, grain mixtures, ionizing continua, densities, and ionization parameters. The conditions were appropriate for such diverse objects as H(II) regions, planetary nebulae, starburst galaxies, and the narrow- and broad-line regions of active nuclei. The ratio of the total thermal grain emission relative to H-Beta (IR/H-Beta) is the primary indicator of whether the cloud behaves as a classical Stroemgren sphere (a hydrogen-bounded nebula) or whether grains absorb most of the incident continuum (a dust-bounded nebula). We find two global limits: when IR/H-Beta > 100, the grains act as a bolometer to measure the luminosity.

  12. THE LINK BETWEEN PLANETARY SYSTEMS, DUSTY WHITE DWARFS, AND METAL-POLLUTED WHITE DWARFS

    International Nuclear Information System (INIS)

    Debes, John H.; Walsh, Kevin J.; Stark, Christopher

    2012-01-01

    It has long been suspected that metal-polluted white dwarfs (types DAZ, DBZ, and DZ) and white dwarfs with dusty disks possess planetary systems, but a specific physical mechanism by which planetesimals are perturbed close to a white dwarf has not yet been fully posited. In this paper, we demonstrate that mass loss from a central star during post-main-sequence evolution can sweep planetesimals into interior mean motion resonances with a single giant planet. These planetesimals are slowly removed through chaotic excursions of eccentricity that in time create radial orbits capable of tidally disrupting the planetesimal. Numerical N-body simulations of the solar system show that a sufficient number of planetesimals are perturbed to explain white dwarfs with both dust and metal pollution, provided other white dwarfs have more massive relic asteroid belts. Our scenario requires only one Jupiter-sized planet and a sufficient number of asteroids near its 2:1 interior mean motion resonance. Finally, we show that once a planetesimal is perturbed into a tidal crossing orbit, it will become disrupted after the first pass of the white dwarf, where a highly eccentric stream of debris forms the main reservoir for dust-producing collisions. These simulations, in concert with observations of white dwarfs, place interesting limits on the frequency of planetary systems around main-sequence stars, the frequency of planetesimal belts, and the probability that dust may obscure future terrestrial planet finding missions.

  13. The Nearby, Young, Argus Association: Membership, Age, and Dusty Debris Disks

    Science.gov (United States)

    Zuckerman, Ben

    2018-01-01

    The Argus Association (AA) defined by Torres et al. (2008) is distinguished from other nearby young moving groups by virtue of its unusual Galactic U-velocity. As defined by Torres et al, their initial AA consisted of 35 members of the IC 2391 open cluster (~135 pc from Earth) and 29 “field members”, 15 of which are within 100 pc of Earth. The spectral types range from F through K with the exception of two M-type members of IC 2391. Zuckerman et al. (2011 & 2012) proposed 13 additional field members – 12 A-type and one F-type -- all of which lie within 80 pc of Earth. Additional AA members have been proposed, typically a few at a time, by other researchers. Deduced ages of the AA (via various techniques) lie, typically, between 40 and 60 Myr. Bell et al (2015) consider the membership and age of a subset of proposed AA stars via color-magnitude diagrams combined with a Bayesian analysis (following Malo et al 2013 & 2014). For the sample of AA stars that they considered, the group age, membership status of individual stars, and even the reality of a coeval moving group were in some doubt. The purpose of the present communication is to consider all proposed AA members – including the frequency of dusty debris disks -- in an attempt to bring some clarity to what is going on.

  14. Dustiness test of nanopowders using a standard rotating drum with a modified sampling train

    International Nuclear Information System (INIS)

    Tsai, Chuen-Jinn; Wu, Chien-Hsien; Leu, Ming-Long; Chen, Sheng-Chieh; Huang, Cheng-Yu; Tsai, Perng-Jy; Ko, Fu-Hsiang

    2009-01-01

    The standard rotating drum tester was used to determine the dustiness of two nanopowders, nano-TiO 2 and fine ZnO, in standard 1-min tests. Then, the sampling train was modified to determine the number and mass distributions of the generated particles in the respirable size range using a Scanning Mobility Particle Sizer (SMPS), an Aerodynamic Particle Sizer (APS) and a Multi-orifice Uniform Deposit Impactor (MOUDI) in the 30-min tests. It was found that very few particles below 100 nm were generated and the released rate of particles decreased with increasing rotation time for both nanopowders in the 30-min tests. Due to the fluffy structure of the released TiO 2 agglomerated particles, the mass distributions measured by the MOUDI showed large differences with those determined by the APS assuming the apparent bulk densities of the powders. The differences were small for the ZnO agglomerates, which were more compact than the TiO 2 agglomerates.

  15. Projection of American dustiness in the late 21st century due to climate change.

    Science.gov (United States)

    Pu, Bing; Ginoux, Paul

    2017-07-17

    Climate models project rising drought risks over the southwestern and central U.S. in the twenty-first century due to increasing greenhouse gases. The projected drier regions largely overlay the major dust sources in the United States. However, whether dust activity in U.S. will increase in the future is not clear, due to the large uncertainty in dust modeling. This study found that changes of dust activity in the U.S. in the recent decade are largely associated with the variations of precipitation, soil bareness, and surface winds speed. Using multi-model output under the Representative Concentration Pathways 8.5 scenario, we project that climate change will increase dust activity in the southern Great Plains from spring to fall in the late half of the twenty-first century - largely due to reduced precipitation, enhanced land surface bareness, and increased surface wind speed. Over the northern Great Plains, less dusty days are expected in spring due to increased precipitation and reduced bareness. Given the large negative economic and societal consequences of severe dust storms, this study complements the multi-model projection on future dust variations and may help improve risk management and resource planning.

  16. Dust-acoustic rogue waves in a nonextensive plasma

    Science.gov (United States)

    Moslem, W. M.; Sabry, R.; El-Labany, S. K.; Shukla, P. K.

    2011-12-01

    We present an investigation for the generation of a dust-acoustic rogue wave in a dusty plasma composed of negatively charged dust grains, as well as nonextensive electrons and ions. For this purpose, the reductive perturbation technique is used to obtain a nonlinear Schrödinger equation. The critical wave-number threshold kc, which indicates where the modulational instability sets in, has been determined precisely for various regimes. Two different behaviors of kc against the nonextensive parameter q are found. For small kc, it is found that increasing q would lead to an increase of kc until q approaches a certain value qc, then further increase of q beyond qc decreases the value of kc. For large kc, the critical wave-number threshold kc is always increasing with q. Within the modulational instability region, a random perturbation of the amplitude grows and thus creates dust-acoustic rogue waves. In order to show that the characteristics of the rogue waves are influenced by the plasma parameters, the relevant numerical analysis of the appropriate nonlinear solution is presented. The nonlinear structure, as reported here, could be useful for controlling and maximizing highly energetic pulses in dusty plasmas.

  17. PREFACE: 14th Latin American Workshop on Plasma Physics (LAWPP 2011)

    Science.gov (United States)

    Bilbao, Luis; Minotti, Fernando; Kelly, Hector

    2012-06-01

    These proceedings present the written contributions from participants of the Latin American Workshop on Plasma Physics (LAWPP), which was held in Mar del Plata, Argentina, on 20-25 November 2011. This was the 14th session of the series of LAWPP biennial meetings, which started in 1982. The five-day scientific program of LAWPP 2011 consisted of 32 talks and various poster sessions, with the participation of 135 researchers from Argentina, Brazil, Canada, Chile, Colombia, Mexico, Puerto Rico, USA, Venezuela, as well as others from Europe and Asia. In addition, a School on Plasma Physics and a Workshop on Industrial Applications of Plasma Technology (AITP) were organized together with the main meeting. The five-day School held in the week previous to the meeting was intended for young scientists starting their research in Plasma Physics. On the other hand, the objective of the AITP Workshop was to enhance regional academic and industrial cooperation in the field of plasma assisted surface technology. Topics addressed at LAWPP 2011 included space plasmas, dusty plasmas, nuclear fusion, non-thermal plasmas, basic plasma processes, plasma simulation and industrial plasma applications. This variety of subjects is reflected in these proceedings, which the editors hope will result in enjoyable and fruitful reading for those interested in Plasma Physics. It is a pleasure to thank the Institutions that sponsored the meeting, as well as all the participants and collaborators for making this meeting possible. The Editors Luis Bilbao, Fernando Minotti and Hector Kelly LAWPP participants Participants of the 14th Latin American Workshop on Plasma Physics, 20-25 November 2011, Mar del Plata, Argentina International Scientific Committee Carlos Alejaldre, Spain María Virginia Alves, Brazil Ibere Caldas, Brazil Luis Felipe Delgado-Aparicio, Peru Mayo Villagrán, Mexico Kohnosuke Sato, Japan Héctor Kelly, Argentina Edberto Leal-Quirós, Puerto Rico George Morales, USA Julio Puerta

  18. On the wake structure in streaming complex plasmas

    International Nuclear Information System (INIS)

    Ludwig, Patrick; Kählert, Hanno; Bonitz, Michael; Miloch, Wojciech J

    2012-01-01

    The theoretical description of complex (dusty) plasmas requires multiscale concepts that adequately incorporate the correlated interplay of streaming electrons and ions, neutrals and dust grains. Knowing the effective dust-dust interaction, the multiscale problem can be effectively reduced to a one-component plasma model of the dust subsystem. The goal of this paper is a systematic evaluation of the electrostatic potential distribution around a dust grain in the presence of a streaming plasma environment by means of two complementary approaches: (i) a high-precision computation of the dynamically screened Coulomb potential from the dynamic dielectric function and (ii) full 3D particle-in-cell simulations, which self-consistently include dynamical grain charging and nonlinear effects. The range of applicability of these two approaches is addressed. (paper)

  19. Plasma turbulence

    International Nuclear Information System (INIS)

    Horton, W.

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates

  20. Self-consistent steady state and dust-ion-acoustic soliton propagation in inhomogeneous plasmas

    International Nuclear Information System (INIS)

    Li Yangfang; Ma, J.X.

    2005-01-01

    The steady state of an inhomogeneous collisional dusty plasma is formulated self-consistently and the dust-ion-acoustic soliton propagation in such a plasma is studied by using the reductive perturbation method. The steady state is governed by the ambipolar diffusion theory, which includes the spatially varying collisions of electrons and ions with dust grains and is solved numerically with the boundary value problem. The effects of the nonuniformity of the equilibrium quantities on the solitons are considered. It is shown that the property of the solitons, especially the characteristic width, are sensitive to the variations of the steady state

  1. An Extreme Protocluster of Luminous Dusty Starbursts in the Early Universe

    Science.gov (United States)

    Oteo, I.; Ivison, R. J.; Dunne, L.; Manilla-Robles, A.; Maddox, S.; Lewis, A. J. R.; de Zotti, G.; Bremer, M.; Clements, D. L.; Cooray, A.; Dannerbauer, H.; Eales, S.; Greenslade, J.; Omont, A.; Perez–Fournón, I.; Riechers, D.; Scott, D.; van der Werf, P.; Weiss, A.; Zhang, Z.-Y.

    2018-03-01

    We report the identification of an extreme protocluster of galaxies in the early universe whose core (nicknamed Distant Red Core, DRC, because of its very red color in Herschel SPIRE bands) is formed by at least 10 dusty star-forming galaxies (DSFGs), spectroscopically confirmed to lie at {z}spec}=4.002 via detection of [C I](1–0), 12CO(6–5), 12CO(4–3), 12CO(2–1), and {{{H}}}2{{O}}({2}11{--}{2}02) emission lines with ALMA and ATCA. These DSFGs are distributed over a 260 {kpc}× 310 {kpc} region and have a collective obscured star formation rate (SFR) of ∼ 6500 {M}ȯ {yr}}-1, considerably higher than those seen before in any protocluster at z≳ 4. Most of the star formation is taking place in luminous DSFGs since no Lyα emitters are detected in the protocluster core, apart from a Lyα blob located next to one of the DRC components, extending over 60 {kpc}. The total obscured SFR of the protocluster could rise to {SFR}∼ {{14,400}} {M}ȯ {yr}}-1 if all the members of an overdensity of bright DSFGs discovered around DRC in a wide-field Large APEX BOlometer CAmera 870 μm image are part of the same structure. [C I](1–0) emission reveals that DRC has a total molecular gas mass of at least {M}{{{H}}2}∼ 6.6× {10}11 {M}ȯ , and its total halo mass could be as high as ∼ 4.4× {10}13 {M}ȯ , indicating that it is the likely progenitor of a cluster at least as massive as Coma at z = 0.

  2. Outflows, dusty cores, and a burst of star formation in the North America and Pelican nebulae

    Energy Technology Data Exchange (ETDEWEB)

    Bally, John [Department of Astrophysical and Planetary Sciences, University of Colorado, UCB 389, Boulder, CO 80309 (United States); Ginsburg, Adam [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei Munchen (Germany); Probst, Ron [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Reipurth, Bo [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii at Manoa, 640 North A' ohoku Place, Hilo, HI 96720 (United States); Shirley, Yancy L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Stringfellow, Guy S., E-mail: John.Bally@colorado.edu, E-mail: aginsburg@eso.org, E-mail: probst@noao.edu, E-mail: reipurth@ifa.hawaii.edu, E-mail: yshirley@as.arizona.edu, E-mail: Guy.Stringfellow@colorado.edu [Center for Astrophysics and Space Astronomy, University of Colorado, UCB 389, Boulder, CO 80309 (United States)

    2014-12-01

    We present observations of near-infrared 2.12 μm molecular hydrogen outflows emerging from 1.1 mm dust continuum clumps in the North America and Pelican Nebula (NAP) complex selected from the Bolocam Galactic Plane Survey (BGPS). Hundreds of individual shocks powered by over 50 outflows from young stars are identified, indicating that the dusty molecular clumps surrounding the NGC 7000/IC 5070/W80 H II region are among the most active sites of ongoing star formation in the solar vicinity. A spectacular X-shaped outflow, MHO 3400, emerges from a young star system embedded in a dense clump more than a parsec from the ionization front associated with the Pelican Nebula (IC 5070). Suspected to be a binary, the source drives a pair of outflows with orientations differing by 80°. Each flow exhibits S-shaped symmetry and multiple shocks indicating a pulsed and precessing jet. The 'Gulf of Mexico', located south of the North America Nebula (NGC 7000), contains a dense cluster of molecular hydrogen objects (MHOs), Herbig-Haro (HH) objects, and over 300 young stellar objects (YSOs), indicating a recent burst of star formation. The largest outflow detected thus far in the North America and Pelican Nebula complex, the 1.6 parsec long MHO 3417 flow, emerges from a 500 M {sub ☉} BGPS clump and may be powered by a forming massive star. Several prominent outflows such as MHO 3427 appear to be powered by highly embedded YSOs only visible at λ > 70 μm. An 'activity index' formed by dividing the number of shocks by the mass of the cloud containing their source stars is used to estimate the relative evolutionary states of Bolocam clumps. Outflows can be used as indicators of the evolutionary state of clumps detected in millimeter and submillimeter dust continuum surveys.

  3. DUSTY ENVIRONMENT IMPACT ON LIFESPAN OF THE INDUCTION MOTORS STATOR WINDING

    Directory of Open Access Journals (Sweden)

    V. E. Krivonosov

    2015-01-01

    Full Text Available Large quantity of asynchronous motors work in heavily dusted environments. On the end-winding insulation of the motors to 55 kW operating in the mining and smelting enterprise there is a 3 cm dust layer, which may lead to the asynchronous motor end-winding local overheat and consequent early breakdown. Contemporary literature allocates insufficient consideration to the issue of studying the impact the winding dust pollution has on the motor lifespan; for the most part they are experimental researches. The article investigates and establishes correlation relationship between the additional winding heating and the end-winding dust layer thickness. The investigation considers the induction motor winding to be a homogeneous solid and assumes the motor thermal conditions steady inasmuch as the winding insulation dust-cover forming time is much greater than the motor-heating time constant. The obtained expression permits determining the winding dust level by temperature variations; the dependence has linear character. Neither the motor type, size, nor the capacity do affect the local insulation overheating since the temperature difference between the windings being dust laden does not exceed 10 % for asynchronous motors of various capacity. The authors develop an appliance that enables the winding dustiness level monitoring and signals of necessity for the preventive cleaning measures implementation. The appliance operation principle is based on measuring results comparison of the two temperature-sensing devices mounted on the end-winding: one – in the upper part, and the other – in the bottom. The differential in the sensors reading-out allows estimating the dust layer sedimentation on the end-winding. A patent of invention has been issued on the investigation results. 

  4. Dust Growth in Astrophysical Plasmas

    Science.gov (United States)

    Bingham, R.; Tsytovich, V. N.

    2002-12-01

    Dust formation in space is important in diverse environments such as dust molecular clouds, proto-planetary nebulae, stellar outbursts, and supernova explosions. The formation of dust proceeds the formation of stellar objects and planets. In all these environments the dust particles interact with both neutral and plasma particles as well as with (ultraviolet) radiation and cosmic rays. The conventional view of grain growth is one based on accretion by the Van der Waals and chemical forces [Watson and Salpeter [14] considered in detail both theoretically and numerically (Kempf at all [6],Meaking [7]( and confirmed recently by micro-gravity experiments Blum et all [2]). The usual point of view is that the dust grow is occurring in dust molecular clouds at very low temperatures ~ (10 - 30)° K and is a slow process - dust grows to a size of about 0.1 μm in 106 - 109 years. This contradicts recent observations of dust growing in winds of C-stars in about 10 years and behind the supernova SN1987A shock in about 500 days. Also recent observation of star formation at the edge of irradiated dust clouds suggests that new plasma mechanism operates in star formation. Dusty plasma mechanisms of agglomeration are analyzed as an explanation of the new astrophysical observation. New micro-gravity experiments are proposed for observing the plasma mechanisms of dust agglomeration at gas pressures substantially higher than used in ([2]. Calculations for the growth rates of dust agglomeration due to plasma mechanisms are presented. It is shown that at large neutral gas densities the dust plasma attraction provides an explanation of dust grow in about 10 days observed in H-star winds. Ionization by cosmic rays and by radioactive dust can provide the dust attraction necessary for forming dust clumping observed in molecular clouds and the fractal plasma clumping can enhance the time to reach the gravitational contraction phase operating at the final stage of star formation. A new

  5. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1990-06-01

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  6. Propagation of a strong spherical shock wave in a gravitating or non-gravitating dusty gas with exponentially varying density

    Science.gov (United States)

    Nath, G.; Vishwakarma, J. P.

    2016-06-01

    The propagation of a strong spherical shock wave in a dusty gas with or without self-gravitational effects is investigated in the case of isothermal and adiabatic flows. The dusty gas is assumed to be a mixture of small solid particles and perfect gas. The equilibrium flow conditions are assumed to be maintained, and the density of the mixture is assumed to be varying and obeying an exponential law. Non-similarity solutions are obtained and the effects of variations of the mass concentration of solid particles in the mixture and the ratio of the density of solid particles to the initial density of the gas, and the presence of self-gravitational field on the flow variables are investigated at given times. Our analysis reveals that after inclusion of gravitational field effects surprisingly the shock strength increases and remarkable differences are found in the distribution of flow variables. An increase in time also, increases the shock strength. Further, it is investigated that the consideration of isothermal flow increases the shock strength, and removes the singularity in the density distribution. Also, the presence of gravitational field increases the compressibility of the medium, due to which it is compressed and therefore the distance between the inner contact surface and the shock surface is reduced. The shock waves in self-gravitating dusty gas can be important for description of shocks in supernova explosions, in the study of central part of star burst galaxies, star formation and shocks in stellar explosion, nuclear explosion, in industry, rupture of a pressurized vessel and explosion in the ionosphere. Other potential applications of this study include analysis of data from exploding wire experiments and cylindrically symmetric hypersonic flow problems associated with meteors or re-entry of vehicles etc. A comparison is made between the solutions in the cases of the gravitating and the non-gravitating media. The obtained solutions are applicable for

  7. Plasma harmonics

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  8. Wasp-17b versus other hot-Jupiters being surveyed with HST: A clear versus dusty/hazy atmospheres

    Science.gov (United States)

    Ballester, G. E.; Nikolov, N.; Wakeford, H.; Thompson, R.

    2014-03-01

    A large HST optical and near-IR spectral survey of eight hot-Jupiter exoplanets is being carried out (D. Sing, PI) in which we are studying planets spanning a large temperature regime (1000-3000 K). Together with previous HST observations, this program is showing hot Jupiters with lower atmospheres where the optical and near-IR transit signatures are dominated by, or have a significant contribution from, scattering by aerosols. This is the well-known case for the relatively cooler HD 189733b on which fine silicate grains may have been detected (Pont et al. 2008, 2013; Lecavelier et al. 2008; Sing et al. 2011; Evans et al. 2013), the more recent case of the hotter Hat-P-1b (Wakeford et al. 2013; Nikolov et al. 2013), and the surprising case of the very-hot-Jupiter Wasp-12b on which fine-grains of corundum may have been detected (Sing et al. 2013). Evidence for aerosols has also been found with Kepler for Kepler-7b (Demory et al. 2013). Under this large HST survey, we have recently observed transits of Wasp-17b in the optical with HST/STIS, and we are combining these data with archival HST/WFC3 near-IR (1.09-1.69 microns) transit data and with Spitzer/IRAC 4.5 and 8 um transit photometry (Ballester et al. 2014). Wasp-17b presents an interesting case of the most highly inflated hot Jupiter (0.49 MJup, 1.99 RJup) known to date that is also on a retrograde orbit (at 0.0515 AU around a hot F6V star) indicating a violent history for the system (Anderson et al. 2010). The average dayside temperature for the planet is 1580-1880 K (Anderson et al. 2011). In contrast to the above cases of dusty/hazy atmospheres, our preliminary results show a clear atmosphere on Wasp-17b. The planet presents the best case so far of a hot Jupiter that is consistent with a cloud-free atmosphere given that the optical radius is much smaller than the near-IR radius (i.e., scattering by dust or haze is not obscuring the expected transit signatures of a clear lower atmosphere). Water absorption is

  9. Landau damping of dust acoustic solitary waves in nonthermal plasmas

    Science.gov (United States)

    Ghai, Yashika; Saini, N. S.; Eliasson, B.

    2018-01-01

    Dust acoustic (DA) solitary and shock structures have been investigated under the influence of Landau damping in a dusty plasma containing two temperature nonthermal ions. Motivated by the observations of Geotail spacecraft that reported two-temperature ion population in the Earth's magnetosphere, we have investigated the effect of resonant wave-particle interactions on DA nonlinear structures. The Korteweg-de Vries (KdV) equation with an additional Landau damping term is derived and its analytical solution is presented. The solution has the form of a soliton whose amplitude decreases with time. Further, we have illustrated the influence of Landau damping and nonthermality of the ions on DA shock structures by a numerical solution of the Landau damping modified KdV equation. The study of the time evolution of shock waves suggests that an initial shock-like pulse forms an oscillatory shock at later times due to the balance of nonlinearity, dispersion, and dissipation due to Landau damping. The findings of the present investigation may be useful in understanding the properties of nonlinear structures in the presence of Landau damping in dusty plasmas containing two temperature ions obeying nonthermal distribution such as in the Earth's magnetotail.

  10. Placental complications after a previous cesarean section

    OpenAIRE

    Milošević Jelena; Lilić Vekoslav; Tasić Marija; Radović-Janošević Dragana; Stefanović Milan; Antić Vladimir

    2009-01-01

    Introduction The incidence of cesarean section has been rising in the past 50 years. With the increased number of cesarean sections, the number of pregnancies with the previous cesarean section rises as well. The aim of this study was to establish the influence of the previous cesarean section on the development of placental complications: placenta previa, placental abruption and placenta accreta, as well as to determine the influence of the number of previous cesarean sections on the complic...

  11. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described for electron beam heating of a high-density plasma to drive a fast liner. An annular or solid relativistic electron beam is used to heat a plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the plasma then converges on a fast liner to explosively or ablatively drive the liner to implosion. (U.K.)

  12. Unsteady MHD flow of a dusty nanofluid past a vertical stretching surface with non-uniform heat source/sink

    Directory of Open Access Journals (Sweden)

    C. Sulochana

    2016-02-01

    Full Text Available We analyzed the momentum and heat transfer characteristics of unsteady MHD flow of a dusty nanofluid over a vertical stretching surface in presence of volume fraction of dust and nano particles with non uniform heat source/sink. We considered two types of nanofluids namely Ag-water and Cu-water embedded with conducting dust particles. The governing equations are transformed in to nonlinear ordinary differential equations by using similarity transformation and solved numerically using Shooting technique. The effects of non-dimensional governing parameters on velocity and temperature profiles for fluid and dust phases are discussed and presented through graphs. Also, the skin friction coefficient and Nusselt number are discussed and presented for two dusty nanofluids separately in tabular form. Results indicate that an increase in the volume fraction of dust particles enhances the heat transfer in Cu-water nanofluid compared with Ag-water nanofluid and a raise in the volume fraction of nano particles shows uniform heat transfer in both Cu-water and Ag-water nanofluids.

  13. The Atacama Cosmology Telescope: Dusty Star-Forming Galaxies and Active Galactic Nuclei in the Southern Survey

    Science.gov (United States)

    Marsden, Danica; Gralla, Megan; Marriage, Tobias A.; Switzer, Eric R.; Partridge, Bruce; Massardi, Marcella; Morales, Gustavo; Addison, Graeme; Bond, J. Richard; Crighton, Devin; hide

    2014-01-01

    We present a catalogue of 191 extragalactic sources detected by the Atacama Cosmology Telescope (ACT) at 148 and/or 218 GHz in the 2008 Southern survey. Flux densities span 14 -1700 mJy, and we use source spectral indices derived using ACT-only data to divide our sources into two subpopulations: 167 radio galaxies powered by central active galactic nuclei (AGN) and 24 dusty star-forming galaxies (DSFGs). We cross-identify 97 per cent of our sources (166 of the AGN and 19 of the DSFGs) with those in currently available catalogues. When combined with flux densities from the Australia Telescope 20 GHz survey and follow-up observations with the Australia Telescope Compact Array, the synchrotron-dominated population is seen to exhibit a steepening of the slope of the spectral energy distribution from 20 to 148 GHz, with the trend continuing to 218 GHz. The ACT dust-dominated source population has a median spectral index, A(sub 148-218), of 3.7 (+0.62 or -0.86), and includes both local galaxies and sources with redshift around 6. Dusty sources with no counterpart in existing catalogues likely belong to a recently discovered subpopulation of DSFGs lensed by foreground galaxies or galaxy groups.

  14. THE EXTENDED HIGH A ( V ) QUASAR SURVEY: SEARCHING FOR DUSTY ABSORBERS TOWARD MID-INFRARED-SELECTED QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Krogager, J.-K.; Noterdaeme, P. [Institut d’Astrophysique de Paris, CNRS-UPMC, UMR7095, 98bis bd Arago, F-75014 Paris (France); Fynbo, J. P. U.; Heintz, K. E.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Geier, S. [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Ledoux, C. [European Southern Observatory, Alonso de Córdova 3107, Vitacura, Casilla 19001, Santiago 19 (Chile); Møller, P. [European Southern Observatory, Karl-Schwarzschildstrasse 2, D-85748 Garching bei München (Germany); Venemans, B. P. [Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

    2016-11-20

    We present the results of a new spectroscopic survey for dusty intervening absorption systems, particularly damped Ly α absorbers (DLAs), toward reddened quasars. The candidate quasars are selected from mid-infrared photometry from the Wide-field Infrared Survey Explorer combined with optical and near-infrared photometry. Out of 1073 candidates, we secure low-resolution spectra for 108 using the Nordic Optical Telescope on La Palma, Spain. Based on the spectra, we are able to classify 100 of the 108 targets as quasars. A large fraction (50%) is observed to have broad absorption lines (BALs). Moreover, we find six quasars with strange breaks in their spectra, which are not consistent with regular dust reddening. Using template fitting, we infer the amount of reddening along each line of sight ranging from A ( V ) ≈ 0.1 to 1.2 mag (assuming a Small Magellanic Cloud extinction curve). In four cases, the reddening is consistent with dust exhibiting the 2175 Å feature caused by an intervening absorber, and for two of these, an Mg ii absorption system is observed at the best-fit absorption redshift. In the rest of the cases, the reddening is most likely intrinsic to the quasar. We observe no evidence for dusty DLAs in this survey. However, the large fraction of BAL quasars hampers the detection of absorption systems. Out of the 50 non-BAL quasars, only 28 have sufficiently high redshift to detect Ly α in absorption.

  15. Preoperative screening: value of previous tests.

    Science.gov (United States)

    Macpherson, D S; Snow, R; Lofgren, R P

    1990-12-15

    To determine the frequency of tests done in the year before elective surgery that might substitute for preoperative screening tests and to determine the frequency of test results that change from a normal value to a value likely to alter perioperative management. Retrospective cohort analysis of computerized laboratory data (complete blood count, sodium, potassium, and creatinine levels, prothrombin time, and partial thromboplastin time). Urban tertiary care Veterans Affairs Hospital. Consecutive sample of 1109 patients who had elective surgery in 1988. At admission, 7549 preoperative tests were done, 47% of which duplicated tests performed in the previous year. Of 3096 previous results that were normal as defined by hospital reference range and done closest to the time of but before admission (median interval, 2 months), 13 (0.4%; 95% CI, 0.2% to 0.7%), repeat values were outside a range considered acceptable for surgery. Most of the abnormalities were predictable from the patient's history, and most were not noted in the medical record. Of 461 previous tests that were abnormal, 78 (17%; CI, 13% to 20%) repeat values at admission were outside a range considered acceptable for surgery (P less than 0.001, frequency of clinically important abnormalities of patients with normal previous results with those with abnormal previous results). Physicians evaluating patients preoperatively could safely substitute the previous test results analyzed in this study for preoperative screening tests if the previous tests are normal and no obvious indication for retesting is present.

  16. Automatic electromagnetic valve for previous vacuum

    International Nuclear Information System (INIS)

    Granados, C. E.; Martin, F.

    1959-01-01

    A valve which permits the maintenance of an installation vacuum when electric current fails is described. It also lets the air in the previous vacuum bomb to prevent the oil ascending in the vacuum tubes. (Author)

  17. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  18. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  19. Concomitant and previous osteoporotic vertebral fractures.

    Science.gov (United States)

    Lenski, Markus; Büser, Natalie; Scherer, Michael

    2017-04-01

    Background and purpose - Patients with osteoporosis who present with an acute onset of back pain often have multiple fractures on plain radiographs. Differentiation of an acute osteoporotic vertebral fracture (AOVF) from previous fractures is difficult. The aim of this study was to investigate the incidence of concomitant AOVFs and previous OVFs in patients with symptomatic AOVFs, and to identify risk factors for concomitant AOVFs. Patients and methods - This was a prospective epidemiological study based on the Registry of Pathological Osteoporotic Vertebral Fractures (REPAPORA) with 1,005 patients and 2,874 osteoporotic vertebral fractures, which has been running since February 1, 2006. Concomitant fractures are defined as at least 2 acute short-tau inversion recovery (STIR-) positive vertebral fractures that happen concomitantly. A previous fracture is a STIR-negative fracture at the time of initial diagnostics. Logistic regression was used to examine the influence of various variables on the incidence of concomitant fractures. Results - More than 99% of osteoporotic vertebral fractures occurred in the thoracic and lumbar spine. The incidence of concomitant fractures at the time of first patient contact was 26% and that of previous fractures was 60%. The odds ratio (OR) for concomitant fractures decreased with a higher number of previous fractures (OR =0.86; p = 0.03) and higher dual-energy X-ray absorptiometry T-score (OR =0.72; p = 0.003). Interpretation - Concomitant and previous osteoporotic vertebral fractures are common. Risk factors for concomitant fractures are a low T-score and a low number of previous vertebral fractures in cases of osteoporotic vertebral fracture. An MRI scan of the the complete thoracic and lumbar spine with STIR sequence reduces the risk of under-diagnosis and under-treatment.

  20. ATLANTIC DIP: simplifying the follow-up of women with previous gestational diabetes.

    LENUS (Irish Health Repository)

    Noctor, E

    2013-11-01

    Previous gestational diabetes (GDM) is associated with a significant lifetime risk of type 2 diabetes. In this study, we assessed the performance of HbA1c and fasting plasma glucose (FPG) measurements against that of 75 g oral glucose tolerance testing (OGTT) for the follow-up screening of women with previous GDM.

  1. Investigation of Plasmas Having Complex, Dynamic Evolving Morphology

    Energy Technology Data Exchange (ETDEWEB)

    Bellan, Paul M. [California Inst. of Technology (CalTech), Pasadena, CA (United States)

    2017-01-03

    Three different types of plasmas have been investigated using both experimental and theoretical methods. The first type of plasma is dense, highly ionized, governed by magnetohydrodynamics, and highly dynamic. This plasma is relevant to solar coronal loops, astrophysical jets, and other situations where strong magnetic forces act on the plasma. A well-diagnosed laboratory experiment creates a magnetohydrodynamically driven highly collimated plasma jet. This jet undergoes a kink instability such that it rapidly develops a corkscrew shape. The kink causes lateral acceleration of the jet, and this lateral acceleration drives a Rayleigh-Taylor instability that in turn chokes the current flowing in the jet and causes a magnetic reconnection. The magnetic reconnection causes electron and ion heating as well as emission of whistler waves. This entire sequence of events has been observed, measured in detail, and related to theoretical models. The second type of plasma is a transient rf-produced plasma used as a seed plasma for the magnetohydrodynamic experiments described above. Detailed atomic physics ionization processes have been investigated and modeled. The third type of plasma that has been studied is a dusty plasma where the dust particles are spontaneously growing ice grains. The rapid growth of the ice grains to large size and their highly ordered alignment has been investigated as well as collective motion of the ice grains, including well-defined flows on the surface of nested toroids. In addition to the experimental work described above, several related theoretical models have been developed, most notably a model showing how a complex interaction between gravity and magnetic fields on extremely weakly ionized plasma in an accretion disk provides an electric power source that can drive astrophysical jets associated with the accretion disk. Eighteen papers reporting this work have been published in a wide variety of journals.

  2. Investigation of Plasmas Having Complex, Dynamic Evolving Morphology

    International Nuclear Information System (INIS)

    Bellan, Paul M.

    2017-01-01

    Three different types of plasmas have been investigated using both experimental and theoretical methods. The first type of plasma is dense, highly ionized, governed by magnetohydrodynamics, and highly dynamic. This plasma is relevant to solar coronal loops, astrophysical jets, and other situations where strong magnetic forces act on the plasma. A well-diagnosed laboratory experiment creates a magnetohydrodynamically driven highly collimated plasma jet. This jet undergoes a kink instability such that it rapidly develops a corkscrew shape. The kink causes lateral acceleration of the jet, and this lateral acceleration drives a Rayleigh-Taylor instability that in turn chokes the current flowing in the jet and causes a magnetic reconnection. The magnetic reconnection causes electron and ion heating as well as emission of whistler waves. This entire sequence of events has been observed, measured in detail, and related to theoretical models. The second type of plasma is a transient rf-produced plasma used as a seed plasma for the magnetohydrodynamic experiments described above. Detailed atomic physics ionization processes have been investigated and modeled. The third type of plasma that has been studied is a dusty plasma where the dust particles are spontaneously growing ice grains. The rapid growth of the ice grains to large size and their highly ordered alignment has been investigated as well as collective motion of the ice grains, including well-defined flows on the surface of nested toroids. In addition to the experimental work described above, several related theoretical models have been developed, most notably a model showing how a complex interaction between gravity and magnetic fields on extremely weakly ionized plasma in an accretion disk provides an electric power source that can drive astrophysical jets associated with the accretion disk. Eighteen papers reporting this work have been published in a wide variety of journals.

  3. Uterine rupture without previous caesarean delivery

    DEFF Research Database (Denmark)

    Thisted, Dorthe L. A.; H. Mortensen, Laust; Krebs, Lone

    2015-01-01

    OBJECTIVE: To determine incidence and patient characteristics of women with uterine rupture during singleton births at term without a previous caesarean delivery. STUDY DESIGN: Population based cohort study. Women with term singleton birth, no record of previous caesarean delivery and planned...... vaginal delivery (n=611,803) were identified in the Danish Medical Birth Registry (1997-2008). Medical records from women recorded with uterine rupture during labour were reviewed to ascertain events of complete uterine rupture. Relative Risk (RR) and adjusted Relative Risk Ratio (aRR) of complete uterine...... rupture with 95% confidence intervals (95% CI) were ascertained according to characteristics of the women and of the delivery. RESULTS: We identified 20 cases with complete uterine rupture. The incidence of complete uterine rupture among women without previous caesarean delivery was about 3...

  4. Heat transfer to MHD oscillatory dusty fluid flow in a channel filled ...

    Indian Academy of Sciences (India)

    Fluid flow under the influence of magnetic field and heat transfer occurs in magneto-hydrodynamics accelerators, pumps and generators. This type of fluid has uses in nuclear reactors, plasma studies, geothermal energy extraction, and the boundary layer control in the field of aerodynamics. The flow of fluids through porous ...

  5. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A method is described of providing electron beam heating of a high-density plasma to drive a fast liner to implode a structured microsphere. An annular relativistic electron beam is used to heat an annular plasma to kilovolt temperatures through streaming instabilities in the plasma. Energy deposited in the annular plasma then converges on a fast liner to explosively or ablatively drive the liner to convergence to implode the structured microsphere. (U.K.)

  6. ULTRAVIOLET INDUCED MOTION OF A FLUORESCENT DUST CLOUD IN AN ARGON DIRECT CURRENT GLOW DISCHARGE PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Hvasta, M.G.; and Zwicker, A.

    2008-01-01

    Dusty plasmas consist of electrons, ions, neutrals and nm-μm sized particles commonly referred to as dust. In man-made plasmas this dust may represent impurities in a tokamak or plasma etching processing. In astrophysical plasmas this dust forms structures such as planetary rings and comet tails. To study dusty plasma dynamics an experiment was designed in which a 3:1 silica (<5 μm diameter) and fl uorescent dust mixture was added to an argon DC glow discharge plasma and exposed to UV radiation. This fl uorescent lighting technique offers an advantage over laser scattering (which only allows two-dimensional slices of the cloud to be observed) and is simpler than scanning mirror techniques or particle image velocimetry. Under typical parameters (P=150 mTorr, V anode= 100 V, Vcathode= -400 V, Itotal < 2mA) when the cloud is exposed to the UV light (100W, λ = 365 nm) the mixture fl uoresces, moves ~2mm towards the light source and begins rotating in a clockwise manner (as seen from the cathode). By calibrating a UV lamp and adjusting the relative intensity of the UV with a variable transformer it was found that both translational and rotational velocities are a function of UV intensity. Additionally, it was determined that bulk cloud rotation is not seen when the dust tray is not grounded while bulk translation is. This ongoing experiment represents a novel way to control contamination in man-made plasmas and a path to a better understanding of UV-bathed plasma systems in space..

  7. INTRODUCTION Previous reports have documented a high ...

    African Journals Online (AJOL)

    pregnancy if they were married, educated, had dental insurance, previously used dental services when not pregnant, or had knowledge about the possible connection between oral health and pregnancy outcome8. The purpose of this study was to explore the factors determining good oral hygiene among pregnant women ...

  8. Empowerment perceptions of educational managers from previously ...

    African Journals Online (AJOL)

    The perceptions of educational manag ers from previously disadvantaged primary and high schools in the Nelson Mandela Metropole regarding the issue of empowerment are outlined and the perceptions of educational managers in terms of various aspects of empowerment at different levels reflected. A literature study ...

  9. Management of choledocholithiasis after previous gastrectomy.

    Science.gov (United States)

    Anwer, S; Egan, R; Cross, N; Guru Naidu, S; Somasekar, K

    2017-09-01

    Common bile duct stones in patients with a previous gastrectomy can be a technical challenge because of the altered anatomy. This paper presents the successful management of two such patients using non-traditional techniques as conventional endoscopic retrograde cholangiopancreatography was not possible.

  10. Laboratory Grouping Based on Previous Courses.

    Science.gov (United States)

    Doemling, Donald B.; Bowman, Douglas C.

    1981-01-01

    In a five-year study, second-year human physiology students were grouped for laboratory according to previous physiology and laboratory experience. No significant differences in course or board examination performance were found, though correlations were found between predental grade-point averages and grouping. (MSE)

  11. The Christiansen Effect in Saturn's narrow dusty rings and the spectral identification of clumps in the F ring

    Science.gov (United States)

    Hedman, M.M.; Nicholson, P.D.; Showalter, M.R.; Brown, R.H.; Buratti, B.J.; Clark, R.N.; Baines, K.; Sotin, Christophe

    2011-01-01

    Stellar occultations by Saturn's rings observed with the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft reveal that dusty features such as the F ring and the ringlets in the Encke and the Laplace Gaps have distinctive infrared transmission spectra. These spectra show a narrow optical depth minimum at wavelengths around 2.87??m. This minimum is likely due to the Christiansen Effect, a reduction in the extinction of small particles when their (complex) refractive index is close to that of the surrounding medium. Simple Mie-scattering models demonstrate that the strength of this opacity dip is sensitive to the size distribution of particles between 1 and 100??m across. Furthermore, the spatial resolution of the occultation data is sufficient to reveal variations in the transmission spectra within and among these rings. In both the Encke Gap ringlets and F ring, the opacity dip weakens with increasing local optical depth, which is consistent with the larger particles being concentrated near the cores of these rings. The Encke Gap ringlets also show systematically weaker opacity dips than the F ring and Laplace Gap ringlet, implying that the former has a smaller fraction of grains less than ~30??m across. However, the strength of the opacity dip varies most dramatically within the F ring; certain compact regions of enhanced optical depth lack an opacity dip and therefore appear to have a greatly reduced fraction of grains in the few-micron size range. Such spectrally-identifiable structures probably represent a subset of the compact optically-thick clumps observed by other Cassini instruments. These variations in the ring's particle size distribution can provide new insights into the processes of grain aggregation, disruption and transport within dusty rings. For example, the unusual spectral properties of the F-ring clumps could perhaps be ascribed to small grains adhering onto the surface of larger particles in regions of anomalously

  12. Plasma chromatography

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    This book examines the fundamental theory and various applications of ion mobility spectroscopy. Plasma chromatography developed from research on the diffusion and mobility of ions. Topics considered include instrument design and description (e.g., performance, spectral interpretation, sample handling, mass spectrometry), the role of ion mobility in plasma chromatography (e.g., kinetic theory of ion transport), atmospheric pressure ionization (e.g., rate equations), the characterization of isomers by plasma chromatography (e.g., molecular ion characteristics, polynuclear aromatics), plasma chromatography as a gas chromatographic detection method (e.g., qualitative analysis, continuous mobility monitoring, quantitative analysis), the analysis of toxic vapors by plasma chromatography (e.g., plasma chromatograph calibration, instrument control and data processing), the analysis of semiconductor devices and microelectronic packages by plasma chromatography/mass spectroscopy (e.g., analysis of organic surface contaminants, analysis of water in sealed electronic packages), and instrument design and automation (hardware, software)

  13. Previously unknown organomagnesium compounds in astrochemical context

    OpenAIRE

    Ruf, Alexander

    2018-01-01

    We describe the detection of dihydroxymagnesium carboxylates (CHOMg) in astrochemical context. CHOMg was detected in meteorites via ultrahigh-resolving chemical analytics and represents a novel, previously unreported chemical class. Thus, chemical stability was probed via quantum chemical computations, in combination with experimental fragmentation techniques. Results propose the putative formation of green-chemical OH-Grignard-type molecules and triggered fundamental questions within chemica...

  14. [Placental complications after a previous cesarean section].

    Science.gov (United States)

    Milosević, Jelena; Lilić, Vekoslav; Tasić, Marija; Radović-Janosević, Dragana; Stefanović, Milan; Antić, Vladimir

    2009-01-01

    The incidence of cesarean section has been rising in the past 50 years. With the increased number of cesarean sections, the number of pregnancies with the previous cesarean section rises as well. The aim of this study was to establish the influence of the previous cesarean section on the development of placental complications: placenta previa, placental abruption and placenta accreta, as well as to determine the influence of the number of previous cesarean sections on the complication development. The research was conducted at the Clinic of Gynecology and Obstetrics in Nis covering 10-year-period (from 1995 to 2005) with 32358 deliveries, 1280 deliveries after a previous cesarean section, 131 cases of placenta previa and 118 cases of placental abruption. The experimental groups was presented by the cases of placenta previa or placental abruption with prior cesarean section in obstetrics history, opposite to the control group having the same conditions but without a cesarean section in medical history. The incidence of placenta previa in the control group was 0.33%, opposite to the 1.86% incidence after one cesarean section (pcesarean sections and as high as 14.28% after three cesarean sections in obstetric history. Placental abruption was recorded as placental complication in 0.33% pregnancies in the control group, while its incidence was 1.02% after one cesarean section (pcesarean sections. The difference in the incidence of intrapartal hysterectomy between the group with prior cesarean section (0.86%) and without it (0.006%) shows a high statistical significance (pcesarean section is an important risk factor for the development of placental complications.

  15. Plasma volume changes during hypoglycaemia

    DEFF Research Database (Denmark)

    Hilsted, J; Bendtsen, F; Christensen, N J

    1990-01-01

    To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate ...

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

    Science.gov (United States)

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

    2013-12-01

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

  17. Transport Phenomena in Magnetized Plasmas across Coupling Regimes

    Science.gov (United States)

    Baalrud, Scott; Daligault, Jerome

    2015-11-01

    Plasmas with components that are magnetized, strongly coupled, or both arise in a variety of frontier plasma physics experiments including magnetized dusty plasmas, magnetized ICF concepts, as well as from self-generated fields in ICF. Here, a theory is described that treats classical mixtures of magnetized and unmagnetized species across coupling regimes. The approach is based on an extension of the recent effective potential transport theory to include a magnetic field. The utility of this approach is that it can be incorporated into magnetohydrodynamic descriptions by modification of the Coulomb logarithm in the transport coefficients. Like weakly coupled plasma theory, the magnetic field is found to suppress cross-field transport. However, the ratio of parallel to cross field transport rates is much closer to unity at strong coupling. Not only cross field, but also parallel, transport rates are found to be reduced by the field. Results are compared with classical molecular dynamics simulations of self-diffusion of the one component plasma, and with simulations of parallel to perpendicular temperature equilibration of an initially anisotropic distribution. The authors gratefully acknowledge support from Los Alamos National Laboratory grant LDRD 20150520ER.

  18. Recent Science Education Initiatives at the Princeton Plasma Physics Laboratory

    Science.gov (United States)

    Zwicker, Andrew; Dominguez, Arturo; Gershman, Sophia; Guilbert, Nick; Merali, Aliya; Ortiz, Deedee

    2013-10-01

    An integrated approach to program development and implementation has significantly enhanced a variety of Science Education initiatives for students and teachers. This approach involves combining the efforts of PPPL scientists, educators, research and education fellows, and collaborating non-profit organizations to provide meaningful educational experiences for students and teachers. Our undergraduate internship program continues to have outstanding success, with 72% of our participants going to graduate school and 45% concentrating in plasma physics. New partnerships have allowed us to increase the number of underrepresented students participating in mentored research opportunities. The number of participants in our Young Women's Conference increases significantly each year. Our Plasma Camp workshop, now in its 15th year, recruits outstanding teachers from around the country to create new plasma-centered curricula. Student research in the Science Education Laboratory concentrates on the development of a high-fidelity plasma speaker, a particle dropper for a dusty plasma experiment, microplasmas along liquid surfaces for a variety of applications, an Internet-controlled DC glow discharge source for students, and a Planeterrella for demonstrating the aurora and other space weather phenomenon for the general public.

  19. Plasma physics

    CERN Document Server

    Drummond, James E

    1961-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  20. Plasma generator

    International Nuclear Information System (INIS)

    Omichi, Takeo; Yamanaka, Toshiyuki.

    1976-01-01

    Object: To recycle a coolant in a sealed hollow portion formed interiorly of a plasma limiter itself to thereby to cause direct contact between the coolant and the plasma limiter and increase of contact area therebetween to cool the plasma limiter. Structure: The heat resulting from plasma generated during operation and applied to the body of the plasma limiter is transmitted to the coolant, which recycles through an inlet and outlet pipe, an inlet and outlet nozzle and a hollow portion to hold the plasma limiter at a level less than a predetermined temperature. On the other hand, the heater wire is, at the time of emergency operation, energized to heat the plasma limiter, but this heat is transmitted to the limiter body to increase the temperature thereof. However, the coolant recycling the hollow portion comes into direct contact with the limiter body, and since the plasma limiter surround the hollow portion, the heat amount transmitted from the limiter body to the coolant increases to sufficiently cool the plasma limiter. (Yoshihara, H.)

  1. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  2. Induced vaginal birth after previous caesarean section

    Directory of Open Access Journals (Sweden)

    Akylbek Tussupkaliyev

    2016-11-01

    Full Text Available Introduction The rate of operative birth by Caesarean section is constantly rising. In Kazakhstan, it reaches 27 per cent. Research data confirm that the percentage of successful vaginal births after previous Caesarean section is 50–70 per cent. How safe the induction of vaginal birth after Caesarean (VBAC remains unclear. Methodology The studied techniques of labour induction were amniotomy of the foetal bladder with the vulsellum ramus, intravaginal administration of E1 prostaglandin (Misoprostol, and intravenous infusion of Oxytocin-Richter. The assessment of rediness of parturient canals was conducted by Bishop’s score; the labour course was assessed by a partogram. The effectiveness of labour induction techniques was assessed by the number of administered doses, the time of onset of regular labour, the course of labour and the postpartum period and the presence of complications, and the course of the early neonatal period, which implied the assessment of the child’s condition, described in the newborn development record. The foetus was assessed by medical ultrasound and antenatal and intranatal cardiotocography (CTG. Obtained results were analysed with SAS statistical processing software. Results The overall percentage of successful births with intravaginal administration of Misoprostol was 93 per cent (83 of cases. This percentage was higher than in the amniotomy group (relative risk (RR 11.7 and was similar to the oxytocin group (RR 0.83. Amniotomy was effective in 54 per cent (39 of cases, when it induced regular labour. Intravenous oxytocin infusion was effective in 94 per cent (89 of cases. This percentage was higher than that with amniotomy (RR 12.5. Conclusions The success of vaginal delivery after previous Caesarean section can be achieved in almost 70 per cent of cases. At that, labour induction does not decrease this indicator and remains within population boundaries.

  3. OT1_tueta_2: Far-IR Emission from Planetary Nebulae: Simultaneous Mapping and Spectral Probing of the Multi-Phased Dusty Gaseous System

    Science.gov (United States)

    Ueta, T.

    2010-07-01

    We propose to undertake an ambitious Herschel large survey of planetary nebulae (PNs), mustering the full strengths of Herschel's broadband mapping, spectral mapping, and spatio-spectroscopic capabilities. Our proposed PN survey will exploit Herschel's unprecedented spatial-resolving power in the far-IR wavelengths to its fullest potential. We will perform (1) deep PACS/SPIRE broadband mapping to account for the coldest dust component of the nebulae in the target PNs and determine the spatial distribution of the dusty PN haloes, (2) exhaustive PACS/SPIRE line mapping in far-IR fine-structure and CO transition lines in two representative PNs to diagnose the energetics of the nebulae as a function of location in the nebulae, and (3) PACS/SPIRE spectral-energy-distribution spectroscopy at several positions in the target PNs to understand variations in the physical conditions as a function of location in the nebulae. This PN survey is distinguished from the existing MESS KPGT program by the extra dimension added by spectral mapping and spatio-spectroscopy that permit simultaneous probing of the gas and dust component in the target PNs. Through these investigations, we will consider the energetics of the entire gas-dust system as a function of location in the nebulae. Herschel will allow us to take this novel approach which has rarely been taken previously. The proposed Herschel survey will be conducted in collaboration with the recently-approved Chandra X-ray Observatory Large Project to furnish substantial PN data resources that would allow us - a community of PN astronomers - to tackle a multitude of unanswered issues in PN physics, from the shaping mechanisms of the nebulae to the energetics of the multi-phased gas-dust system surrounding the central white dwarf. The proposed Herschel survey and the approved Chandra survey, combined with the community assets from optical to mid-IR, will provide an extremely valuable and comprehensive compilation of PN resource that

  4. Experimental demonstration of Martian soil simulant removal from a surface using a pulsed plasma jet

    Science.gov (United States)

    Ticoş, C. M.; Scurtu, A.; Toader, D.; Banu, N.

    2015-03-01

    A plasma jet produced in a small coaxial plasma gun operated at voltages up to 2 kV and working in pure carbon dioxide (CO2) at a few Torr is used to remove Martian soil simulant from a surface. A capacitor with 0.5 mF is charged up from a high voltage source and supplies the power to the coaxial electrodes. The muzzle of the coaxial plasma gun is placed at a few millimeters near the dusty surface and the jet is fired parallel with the surface. Removal of dust is imaged in real time with a high speed camera. Mars regolith simulant JSC-Mars-1A with particle sizes up to 5 mm is used on different types of surfaces made of aluminium, cotton fabric, polyethylene, cardboard, and phenolic.

  5. Ion-driven instabilities of surface dust ion-acoustic waves in bounded plasma devices

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2018-02-01

    The growth rates of the dust ion-acoustic surface wave in the plasma slab device containing ion streaming passing through the stationary electrons and dusty grains at the speed of wave phase velocity are derived and numerically analyzed. We have found that the growth rates for the resonant symmetric and antisymmetric waves are similar to the case of semi-bounded plasma when we have a thick slab. However, in the case of the symmetric wave, the growth rate moves towards the bulk wave as the slab thickness reduces. In the case of the antisymmetric wave, the growth rate increases fast as the slab thickness decreases. The growth rates of surface waves in a plasma slab are compared with those of semi-bounded and bulk waves.

  6. A New Population of High-z, Dusty Lyman-alpha Emitters and Blobs Discovered by WISE: Feedback Caught in the Act?

    Science.gov (United States)

    Bridge, Carrie R.; Blain, Andrew; Borys, Colin J. K.; Petty, Sara; Benford, Dominic; Eisenhardt, Peter; Farrah, Duncan; Griffith, Roger, L.; Jarrett, Tom; Lonsdale, Carol; hide

    2013-01-01

    By combining data from the NASA Wide-field Infrared Survey Explorer (WISE) mission with optical spectroscopy from the W. M. Keck telescope, we discover a mid-IR color criterion that yields a 78% success rate in identifying rare, typically radio-quiet, 1.6 approx. 10(exp 13)-10(exp 14) Solar L) and have warm colors. They are typically more luminous and warmer than other dusty, z approx.. 2 populations such as submillimeter-selected galaxies and dust-obscured galaxies. These traits are commonly associated with the dust being illuminated by intense active galactic nucleus activity. We hypothesize that the combination of spatially extended Ly-alpha, large amounts of warm IR-luminous dust, and rarity (implying a short-lived phase) can be explained if the galaxies are undergoing brief, intense "feedback" transforming them from an extreme dusty starburst/QSO into a mature galaxy.

  7. Proton driven plasma wakefield generation in a parabolic plasma channel

    Science.gov (United States)

    Golian, Y.; Dorranian, D.

    2017-03-01

    An analytical model for the interaction of charged particle beams and plasma for a wakefield generation in a parabolic plasma channel is presented. In the suggested model, the plasma density profile has a minimum value on the propagation axis. A Gaussian proton beam is employed to excite the plasma wakefield in the channel. While previous works investigated on the simulation results and on the perturbation techniques in case of laser wakefield accelerations for a parabolic channel, we have carried out an analytical model and solved the accelerating field equation for proton beam in a parabolic plasma channel. The solution is expressed by Whittaker (hypergeometric) functions. Effects of plasma channel radius, proton bunch parameters and plasma parameters on the accelerating processes of proton driven plasma wakefield acceleration are studied. Results show that the higher accelerating fields could be generated in the PWFA scheme with modest reductions in the bunch size. Also, the modest increment in plasma channel radius is needed to obtain maximum accelerating gradient. In addition, the simulations of longitudinal and total radial wakefield in parabolic plasma channel are presented using LCODE. It is observed that the longitudinal wakefield generated by the bunch decreases with the distance behind the bunch while total radial wakefield increases with the distance behind the bunch.

  8. Bridge between fusion plasma and plasma processing

    International Nuclear Information System (INIS)

    Ohno, Noriyasu; Takamura, Shuichi

    2008-01-01

    In the present review, relationship between fusion plasma and processing plasma is discussed. From boundary-plasma studies in fusion devices new applications such as high-density plasma sources, erosion of graphite in a hydrogen plasma, formation of helium bubbles in high-melting-point metals and the use of toroidal plasmas for plasma processing are emerging. The authors would like to discuss a possibility of knowledge transfer from fusion plasmas to processing plasmas. (T. Ikehata)

  9. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1991-06-01

    The Magneto-Fluid Dynamics Division continues to study a broad range of problems originating in plasma physics. Its principal focus is fusion plasma physics, and most particularly topics of particular significance for the world magnetic fusion program. During the calendar year 1990 we explored a wide range of topics including RF-induced transport as a plasma control mechanism, edge plasma modelling, further statistical analysis of L and H mode tokamak plasmas, antenna design, simulation of the edge of a tokamak plasma and the L-H transition, interpretation of the CCT experimental results at UCLA, turbulent transport, studies in chaos, the validity of moment approximations to kinetic equations and improved neoclassical modelling. In more basic studies we examined the statistical mechanisms of Coulomb systems and applied plasma ballooning mode theory to conventional fluids in order to obtain novel fluid dynamics stability results. In space plasma physics we examined the problem of reconnection, the effect of Alfven waves in space environments, and correct formulation of boundary conditions of the Earth for waves in the ionosphere

  10. Plasma container

    International Nuclear Information System (INIS)

    Ebisawa, Katsuyuki.

    1985-01-01

    Purpose: To enable to easily detect that the thickness of material to be abraded is reduced to an allowable limit from the outerside of the plasma container even during usual operation in a plasma vessel for a thermonuclear device. Constitution: A labelled material is disposed to the inside or rear face of constituent members of a plasma container undergoing the irradiation of plasma particles. A limiter plate to be abraded in the plasma container is composed of an armour member and heat removing plate, in which the armour member is made of graphite and heat-removing plate is made of copper. If the armour member is continuously abraded under the effect of sputtering due to plasma particles, silicon nitride embedded so far in the graphite at last appears on the surface of the limiter plate to undergo the impact shocks of the plasma particles. Accordingly, abrasion of the limiter material can be detected by a detector comprising gas chromatography and it can easily be detected from the outside of the plasma content even during normal operation. (Horiuchi, T.)

  11. Self-similar flow behind a spherical shock wave in a non-ideal dusty gas under a gravitational field: Isothermal flow

    Science.gov (United States)

    Nath, G.

    2013-10-01

    Similarity solutions are obtained for one-dimensional unsteady isothermal flow of a dusty gas behind a spherical shock wave with time dependent energy input. The dusty gas is assumed to be a mixture of non-ideal (or perfect) gas and small solid particles, in which solid particles are continuously distributed. It is assumed that the equilibrium flow-conditions are maintained, and the viscous stress and heat conduction of the mixture are negligible. The medium is taken to be under the influence of the gravitational field due to a heavy nucleus at the origin (Roche model). The total energy of the flow-field behind the shock is increasing. The effects of an increase in the mass concentration of solid particles, the ratio of the density of the solid particles to the initial density of the gas, the gravitational parameter (or shock Mach number), and the parameter of non-idealness of the gas in the mixture, are investigated. It is shown that due to presence of gravitational field the isothermal compressibility of the medium and the flow-variables increases and the shock strength decreases. A comparison has also been made between the medium with and without gravitational field. The shock waves in dusty medium can be important for description of star formation, shocks in supernova explosions, etc.

  12. PLASMA ENERGIZATION

    Science.gov (United States)

    Furth, H.P.; Chambers, E.S.

    1962-03-01

    BS>A method is given for ion cyclotron resonance heatthg of a magnetically confined plasma by an applied radio-frequency field. In accordance with the invention, the radiofrequency energy is transferred to the plasma without the usual attendent self-shielding effect of plasma polarlzatlon, whereby the energy transfer is accomplished with superior efficiency. More explicitly, the invention includes means for applying a radio-frequency electric field radially to an end of a plasma column confined in a magnetic mirror field configuration. The radio-frequency field propagates hydromagnetic waves axially through the column with the waves diminishing in an intermediate region of the column at ion cyclotron resonance with the fleld frequency. In such region the wave energy is converted by viscous damping to rotational energy of the plasma ions. (AEC)

  13. Plasma device

    International Nuclear Information System (INIS)

    Thode, L.E.

    1981-01-01

    A relativistic electron beam generator or accelerator produces a high-voltage electron beam which is modulated to initiate electron bunching within the beam which is then applied to a high-density target plasma which typically comprises DT, DD, or similar thermonuclear gas at a density of 10 17 to 10 20 electrons per cubic centimeter. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy into a small localized region of the high-density plasma target. The high-temperature plasma can be used to heat a high Z material to generate radiation. Alternatively, a tunable radiation source is produced by using a moderate Z gas or a mixture of high Z and low Z gas as the target plasma. (author)

  14. Superconducting plasmas

    International Nuclear Information System (INIS)

    Ohnuma, Toshiro; Ohno, J.

    1994-01-01

    Superconducting (SC) plasmas are proposed and investigated. The SC plasmas are not yet familiar and have not yet been studied. However, the existence and the importance of SC plasmas are stressed in this report. The existence of SC plasmas are found as follows. There is a fundamental property of Meissner effect in superconductors, which shows a repulsive effect of magnetic fields. Even in that case, in a microscopic view, there is a region of magnetic penetration. The penetration length λ is well-known as London's penetration depth, which is expressed as δ = (m s /μ 0 n s q s 2 ) 1/2 where m s , n s , q s and μ o show the mass, the density, the charge of SC electron and the permeability in free space, respectively. Because this expression is very simple, no one had tried it into more simple and meaningful form. Recently, one of the authors (T.O.) has found that the length can be expressed into more simple and understandable fundamental form as λ = c/ω ps where c = (ε 0 μ 0 ) -1/2 and ω ps = (n s q s 2 /m s ε 0 ) 1/2 are the light velocity and the superconducting plasma frequency. From this simple expression, the penetration depth of the magnetic field to SC is found as a SC plasma skin depth, that is, the fundamental property of SC can be expressed by the SC plasmas. This discovery indicates an importance of the studies of superconducting plasmas. From these points, several properties (propagating modes et al) of SC plasmas, which consist of SC electrons, normal electrons and lattice ions, are investigated in this report. Observations of SC plasma frequency is also reported with a use of Terahertz electromagnet-optical waves

  15. Influence of nanoparticle formation on the time and the space resolved metastable density in argon-acetylene plasmas

    Science.gov (United States)

    Stefanović, I.; Sadeghi, N.; Winter, J.; Sikimić, B.

    2017-06-01

    Different diagnostic techniques are used to monitor the dynamics of electrons and Ar*(1s5) metastable atoms in the active plasma phase and in the afterglow of a capacitively coupled radio-frequency (RF) discharge operated in different gas mixtures and at different input powers. Diode laser absorption at 772.38 nm is used to measure the time resolved density of Ar*(1s5) atoms in either continuous-wave mode or pulsed RF discharges with 100 Hz pulsing frequency. Simultaneously, microwave interferometry recorded the time dependence of the electron density. Different plasma conditions, namely: (1) pure argon, (2) argon +5.9% acetylene before nanoparticle formation, (3) argon +5.9% acetylene after dust particles have been formed and (4) argon with dust particles remaining in the plasma volume but without acetylene are studied. The measured steady-state Ar*(1s5) density in the middle of the reactor is several times larger in the dusty argon plasma than in the pure argon discharge for the same discharge powers. At the same time, the electron density is several times less in the dusty plasma. These changes are caused by dust formation: the electric field in the bulk plasma is enhanced and thus consequently the electron temperature increases. Laser induced fluorescence (LIF) is used to measure the time and space resolved Ar*(1s5) axial distribution. In the pure argon discharge, the axial Ar*(1s5) metastable distribution has a characteristic saddle-like shape with maxima in the region of the sheaths. With dust particles inside, the axial distribution changes dramatically with the maximum at the discharge mid-plane, revealing an α-γ‧ transition. The spatial distribution and absolute density of metastable atoms are influenced by the formation of a void in the cloud of nanoparticles. Depending on the size of the void, the Ar*(1s5) density reduction inside the void is between 30% and 50%. The high Ar*(1s5) metastable density in the dusty plasma afterglow strongly influences

  16. Modeling the Infrared Reverberation Response of the Circumnuclear Dusty Torus in AGNs: The Effects of Cloud Orientation and Anisotropic Illumination

    International Nuclear Information System (INIS)

    Almeyda, Triana; Robinson, Andrew; Richmond, Michael; Vazquez, Billy; Nikutta, Robert

    2017-01-01

    The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN continuum luminosity, a technique known as reverberation mapping. The IR response is the convolution of the AGN ultraviolet/optical light curve with a transfer function that contains information about the size, geometry, and structure of the torus. Here, we describe a new computer model that simulates the reverberation response of a clumpy torus. Given an input optical light curve, the code computes the emission of a 3D ensemble of dust clouds as a function of time at selected IR wavelengths, taking into account light travel delays. We present simulated dust emission responses at 3.6, 4.5, and 30 μ m that explore the effects of various geometrical and structural properties, dust cloud orientation, and anisotropy of the illuminating radiation field. We also briefly explore the effects of cloud shadowing (clouds are shielded from the AGN continuum source). Example synthetic light curves have also been generated, using the observed optical light curve of the Seyfert 1 galaxy NGC 6418 as input. The torus response is strongly wavelength-dependent, due to the gradient in cloud surface temperature within the torus, and because the cloud emission is strongly anisotropic at shorter wavelengths. Anisotropic illumination of the torus also significantly modifies the torus response, reducing the lag between the IR and optical variations.

  17. Modeling the Infrared Reverberation Response of the Circumnuclear Dusty Torus in AGNs: The Effects of Cloud Orientation and Anisotropic Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Almeyda, Triana; Robinson, Andrew; Richmond, Michael; Vazquez, Billy [School of Physics and Astronomy, Rochester Institute of Technology, Rochester, NY 14623 (United States); Nikutta, Robert, E-mail: tra3595@rit.edu [National Optical Astronomy Observatory, 950 N Cherry Ave, Tucson, AZ 85719 (United States)

    2017-07-01

    The obscuring circumnuclear torus of dusty molecular gas is one of the major components of active galactic nuclei (AGN). The torus can be studied by analyzing the time response of its infrared (IR) dust emission to variations in the AGN continuum luminosity, a technique known as reverberation mapping. The IR response is the convolution of the AGN ultraviolet/optical light curve with a transfer function that contains information about the size, geometry, and structure of the torus. Here, we describe a new computer model that simulates the reverberation response of a clumpy torus. Given an input optical light curve, the code computes the emission of a 3D ensemble of dust clouds as a function of time at selected IR wavelengths, taking into account light travel delays. We present simulated dust emission responses at 3.6, 4.5, and 30 μ m that explore the effects of various geometrical and structural properties, dust cloud orientation, and anisotropy of the illuminating radiation field. We also briefly explore the effects of cloud shadowing (clouds are shielded from the AGN continuum source). Example synthetic light curves have also been generated, using the observed optical light curve of the Seyfert 1 galaxy NGC 6418 as input. The torus response is strongly wavelength-dependent, due to the gradient in cloud surface temperature within the torus, and because the cloud emission is strongly anisotropic at shorter wavelengths. Anisotropic illumination of the torus also significantly modifies the torus response, reducing the lag between the IR and optical variations.

  18. Failed Radiatively Accelerated Dusty Outflow Model of the Broad Line Region in Active Galactic Nuclei. I. Analytical Solution

    Energy Technology Data Exchange (ETDEWEB)

    Czerny, B.; Panda, S.; Wildy, C.; Sniegowska, M. [Center for Theoretical Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Li, Yan-Rong; Wang, J.-M. [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049 (China); Hryniewicz, K.; Sredzinska, J. [Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warsaw (Poland); Karas, V., E-mail: bcz@cft.edu.pl [Astronomical Institute, Academy of Sciences, Bocni II 1401, CZ-141 00 Prague (Czech Republic)

    2017-09-10

    The physical origin of the broad line region in active galactic nuclei is still unclear despite many years of observational studies. The reason is that the region is unresolved, and the reverberation mapping results imply a complex velocity field. We adopt a theory-motivated approach to identify the principal mechanism responsible for this complex phenomenon. We consider the possibility that the role of dust is essential. We assume that the local radiation pressure acting on the dust in the accretion disk atmosphere launches the outflow of material, but higher above the disk the irradiation from the central parts causes dust evaporation and a subsequent fallback. This failed radiatively accelerated dusty outflow is expected to represent the material forming low ionization lines. In this paper we formulate simple analytical equations to describe the cloud motion, including the evaporation phase. The model is fully described just by the basic parameters of black hole mass, accretion rate, black hole spin, and viewing angle. We study how the spectral line generic profiles correspond to this dynamic. We show that the virial factor calculated from our model strongly depends on the black hole mass in the case of enhanced dust opacity, and thus it then correlates with the line width. This could explain why the virial factor measured in galaxies with pseudobulges differs from that obtained from objects with classical bulges, although the trend predicted by the current version of the model is opposite to the observed trend.

  19. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  20. Plasma will…

    Czech Academy of Sciences Publication Activity Database

    Lunov, Oleg

    2016-01-01

    Roč. 174, č. 3 (2016), s. 486-487 ISSN 0007-0963 Institutional support: RVO:68378271 Keywords : plasma * ionized gas Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 4.706, year: 2016

  1. Plasma technology

    International Nuclear Information System (INIS)

    Drouet, M.G.

    1984-03-01

    IREQ was contracted by the Canadian Electrical Association to review plasma technology and assess the potential for application of this technology in Canada. A team of experts in the various aspects of this technology was assembled and each team member was asked to contribute to this report on the applications of plasma pertinent to his or her particular field of expertise. The following areas were examined in detail: iron, steel and strategic-metals production; surface treatment by spraying; welding and cutting; chemical processing; drying; and low-temperature treatment. A large market for the penetration of electricity has been identified. To build up confidence in the technology, support should be provided for selected R and D projects, plasma torch demonstrations at full power, and large-scale plasma process testing

  2. Plasma chromograninx

    DEFF Research Database (Denmark)

    Goetze, Jens P; Hilsted, Linda M; Rehfeld, Jens F

    2014-01-01

    Cardiovascular risk assessment remains difficult in elderly patients. We examined whether chromogranin A (CgA) measurement in plasma may be valuable in assessing risk of death in elderly patients with symptoms of heart failure in a primary care setting. A total of 470 patients (mean age 73 years......) were followed for 10 years. For CgA plasma measurement, we used a two-step method including a screening test and a confirmative test with plasma pre-treatment with trypsin. Cox multivariable proportional regression and receiver-operating curve (ROC) analyses were used to assess mortality risk...... of follow-up showed significant additive value of CgA confirm measurements compared with NT-proBNP and clinical variables. CgA measurement in the plasma of elderly patients with symptoms of heart failure can identify those at increased risk of short- and long-term mortality....

  3. BOOK REVIEW: Fundamentals of Plasma Physics

    Science.gov (United States)

    Cargill, P. J.

    2007-02-01

    The widespread importance of plasmas in many areas of contemporary physics makes good textbooks in the field that are both introductory and comprehensive invaluable. This new book by Paul Bellen from CalTech by and large meets these goals. It covers the traditional textbook topics such as particle orbits, the derivation of the MHD equations from Vlasov theory, cold and warm plasma waves, Landau damping, as well as in the later chapters less common subjects such as magnetic helicity, nonlinear processes and dusty plasmas. The book is clearly written, neatly presented, and each chapter has a number of exercises or problems at their end. The author has also thankfully steered clear of the pitfall of filling the book with his own research results. The preface notes that the book is designed to provide an introduction to plasma physics for final year undergraduate and post-graduate students. However, it is difficult to see many physics undergraduates now at UK universities getting to grips with much of the content since their mathematics is not of a high enough standard. Students in Applied Mathematics departments would certainly fare better. An additional problem for the beginner is that some of the chapters do not lead the reader gently into a subject, but begin with quite advanced concepts. Being a multi-disciplinary subject, beginners tend to find plasma physics quite hard enough even when done simply. For postgraduate students these criticisms fade away and this book provides an excellent introduction. More senior researchers should also enjoy the book, especially Chapters 11-17 where more advanced topics are discussed. I found myself continually comparing the book with my favourite text for many years, `The Physics of Plasmas' by T J M Boyd and J J Sanderson, reissued by Cambridge University Press in 2003. Researchers would want both books on their shelves, both for the different ways basic plasma physics is covered, and the diversity of more advanced topics. For

  4. Plasma confinement

    CERN Document Server

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  5. Plasma metallization

    International Nuclear Information System (INIS)

    Crowther, J.M.

    1997-09-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of surface contamination of the films due to plasma treatment was observed but was easily removed by argon ion cleaning. Hydrogen plasma reduction of glass supported silver(l) nitrate and palladium(ll) acetate films reveals that this metallization technique is applicable to a wide variety of metal salts and supports, and has also shown the ability of plasma reduction to retain the complex 'fern-like' structures seen for spin coated silver(l) nitrate layers. Some metal salts are susceptible to decomposition by X-rays. The reduction of Nylon 66 supported gold(lll) chloride films by soft X-rays to produce nanoscopic gold particles has been studied. The spontaneous reduction of these X-ray irradiated support gold(lll) chloride films on exposure to the atmosphere to produce gold rich metallic films has also been reported. (author)

  6. Advanced Plasma Propulsion

    Science.gov (United States)

    2011-11-01

    conditions. Previous studies on the CHT showed that the majority of the xenon propellant is ionized at the border of the annular and cylindrical...edge of the cylindrical portion of the thruster channel). The border between high and low potential follows a portion of the kinetic energy contour...the background RF- produced plasma in CΘP-FARAD, is dominated by electron-neutral colli - sions. As the pressure increases, the frequency of these

  7. Rates of induced abortion in Denmark according to age, previous births and previous abortions

    Directory of Open Access Journals (Sweden)

    Marie-Louise H. Hansen

    2009-11-01

    Full Text Available Background: Whereas the effects of various socio-demographic determinants on a woman's risk of having an abortion are relatively well-documented, less attention has been given to the effect of previous abortions and births. Objective: To study the effect of previous abortions and births on Danish women's risk of an abortion, in addition to a number of demographic and personal characteristics. Data and methods: From the Fertility of Women and Couples Dataset we obtained data on the number of live births and induced abortions by year (1981-2001, age (16-39, county of residence and marital status. Logistic regression analysis was used to estimate the influence of the explanatory variables on the probability of having an abortion in a relevant year. Main findings and conclusion: A woman's risk of having an abortion increases with the number of previous births and previous abortions. Some interactions were was found in the way a woman's risk of abortion varies with calendar year, age and parity. The risk of an abortion for women with no children decreases while the risk of an abortion for women with children increases over time. Furthermore, the risk of an abortion decreases with age, but relatively more so for women with children compared to childless women. Trends for teenagers are discussed in a separate section.

  8. The Plasma Environment at Enceladus and Europa Compared

    Science.gov (United States)

    Rymer, Abigail; Persoon, Ann; Morooka, Michiko; Heuer, Steven; Westlake, Joseph H.

    2017-10-01

    The plasma environment near Enceladus is complex, as revealed during 16 encounters of the Cassini spacecraft. The well documented Enceladus plumes create a dusty, asymmetric exosphere in which electrons can attach to small ice particles - forming anions, and negatively charged nanograins and dust - to the extent that cations can be the lightest charged particles present and, as a result, the dominant current carriers. Several instruments on the Cassini spacecraft are able to measure this environment in both expected and unexpected ways. Cassini Plasma Spectrometer (CAPS) is designed and calibrated to measure the thermal plasma ions and electrons and also measures the energy/charge of charged nanograins when present. Cassini Radio Plasma Wave Sensor (RPWS) measures electron density as derived from the ‘upper hybrid frequency’ which is a function of the total free electron density and magnetic field strength and provides a vital ground truth measurement for Cassini calibration when the density is sufficiently high for it to be well measured. Cassini Langmuir Probe (LP) measures the electron density and temperature via direct current measurement, and both CAPS and LP can provide estimates for the spacecraft potential which we compare. The plasma environment near Europa is similarly complex and, although not so comprehensively equipped and hampered by the non-deployment of its high gain antenna, the Galileo spacecraft made similar measurements during 9 Europa flybys and recent observations have suggested that, like Enceladus, Europa might have active plume activity. We present a detailed comparison of data from the Cassini and Galileo sensors in order to assess the plasma environment observed by the different instruments, discuss what is consistent and otherwise, and the implications for the plasma environment at Enceladus and Europa in the context of work to date as well as implications for future studies.

  9. PREFACE: 15th Latin American Workshop on Plasma Physics (LAWPP 2014) and 21st IAEA TM on Research Using Small Fusion Devices (RUSFD)

    Science.gov (United States)

    Iván Vargas-Blanco, V.; Herrera-Velázquez, J. Julio E.

    2015-03-01

    2014 and was attended by 37 participants formally registered with the IAEA, who joined the LAWPP 2014 participants. Its separate scientific programme had two plenary talks, 12 oral presentations and 14 papers presented in poster sessions on Monday 27 and Tuesday 28 January 2014. The 2nd Workshop on Industrial Applications of Plasma Technology (2nd AITP) was held on 30 and 31 January 2014, had six invited speakers, which included 2 plenary talks, 4 invited talks, 11 oral presentations and 31 contributions in a single poster session on Thursday 30 January, 2014. Its proceedings have been merged with those of the joint meeting. Finally the 1st Costa Rican Summer School on Plasma Physics, held in Santa Clara, San Carlos on 20-24 January 2014, in the week previous to the meetings, had 80 participants, 40 international conferences on different plasma physics topics, and 12 professors. The topics included in the programme of the Joint LAWPP 2014 - 21st IAEA TM RUSFD were: space plasmas, dusty plasmas, nuclear fusion, nonthermal plasmas, plasma space propulsion, basic plasma processes, plasma simulation, and industrial plasma applications among others. We are very grateful to the sponsors of the meetings: the Instituto Tecnológico de Costa Rica, the International Atomic Energy Agency (IAEA), the Universidad Nacional de Costa Rica, and Ad Astra Rocket Company. We also want to thank our exhibitors and contributors: INTERCOVAMEX, Nuclear & Plasma Sciences Society, and the IEEE Costa Rica Chapter. The publication of the proceedings was fully supported by the International Atomic Energy Agency (IAEA). The support of the International Advisory and the Local Organizing Committees, is also acknowledged in a heartfelt way. Finally, the Editors of this special issue are grateful to José Asenjo for his excellent work and cooperation for the preparation of the proceedings. Iván Vargas-Blanco and J. Julio E. Herrera-Velázquez Editors of the proceedings

  10. Cyclotron radiation from hot plasmas

    International Nuclear Information System (INIS)

    Pohl, F.; Henning, J.; Duechs, D.

    1975-11-01

    In calculating the energy transport and losses due to cyclotron radiation there are two major requirements: the absorption coefficient has to be known and the proper geometry of the plasma has to be taken into account. In this report Trubnikov's integral formulae for the absorption coefficient have been evaluated numerically and compared with the approximative formulas of previous authors. Deviations by a factor of 2 - 10 in various frequency regimes are not unusual. With these coefficients the rate of change of the energy density due to cyclotron radiation in a plasma as well as the radiation density at a plasma surface are computed for plasma slab and plasma cylinder. Sometimes considerable differences to the results of previons papers can found. Many simple formulae interpolating the numerical results are given in the text, and the FORTRAN computer programs have been reproduced in the appendices. (orig.) [de

  11. Congruency sequence effects are driven by previous-trial congruency, not previous-trial response conflict

    OpenAIRE

    Weissman, Daniel H.; Carp, Joshua

    2013-01-01

    Congruency effects in distracter interference tasks are often smaller after incongruent trials than after congruent trials. However, the sources of such congruency sequence effects (CSEs) are controversial. The conflict monitoring model of cognitive control links CSEs to the detection and resolution of response conflict. In contrast, competing theories attribute CSEs to attentional or affective processes that vary with previous-trial congruency (incongruent vs. congruent). The present study s...

  12. Cold plasmas

    International Nuclear Information System (INIS)

    Franz, G.

    1990-01-01

    This textbook discusses the following topics: Phenomenological description of a direct current glow discharge; the plasma (temperature distribution and measurement, potential variation, electron energy distribution function, charge neutralization, wall potentials, plasma oscillations); Production of charge carriers (ions, electrons, ionization in the cathode zone, negative glowing zone, Faraday dark space, positive column, anode zone, hollow cathode discharges); RF-discharges (charge carrier production, RF-Shields, scattering mechanisms); Sputtering (ion-surface interaction, kinetics, sputtering yield and energy distribution, systems and conditions, film formation and stresses, contamination, bias techniques, multicomponent film deposition, cohesion, magnetrons, triode systems, plasma enhanced chemical vapor deposition); Dry etching (sputter etching, reactive etching, topography, process control, quantitative investigations); Etching mechanisms (etching of Si and SiO 2 with CF 4 , of III/V-compound-semiconductors, combination of isotrope and anisotrope etching methods, surface cleaning); ion beam systems (applications, etching); Dyclotron-resonance-systems (electron cyclotron resonance systems, whistler-sources and 'resonant inductive plasma etching'); Appendix (electron energy distribution functions, Bohm's transition zone, plasma oscillations, scattering cross sections and mean free path, metastable states, Child-Langmuir-Schottky equation, loss mechanisms, charge carrier distribution in the positive column, breakdown at high frequencies, motion in a magnetic field, skin depth of an electric field for a HF-discharge, whistler waves, dispersion relations for plane wave propagation). (orig.) With 138 figs

  13. Planets around Low-mass Stars. III. A Young Dusty L Dwarf Companion at the Deuterium-burning Limit

    Science.gov (United States)

    Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Dupuy, Trent J.

    2013-09-01

    We report the discovery of an L-type companion to the young M3.5V star 2MASS J01225093-2439505 at a projected separation of 1.''45 (≈52 AU) as part of our adaptive optics imaging search for extrasolar giant planets around young low-mass stars. 2MASS 0122-2439 B has very red near-infrared colors similar to the HR 8799 planets and the reddest known young/dusty L dwarfs in the field. Moderate-resolution (R ≈ 3800) 1.5-2.4 μm spectroscopy reveals a near-infrared spectral type of L4-L6 and an angular H-band shape, confirming its cool temperature and young age. The kinematics of 2MASS 0122-2439 AB are marginally consistent with members of the ~120 Myr AB Dor young moving group based on the photometric distance to the primary (36 ± 4 pc) and our radial velocity measurement of 2MASS 0122-2439 A from Keck/HIRES. We adopt the AB Dor group age for the system, but the high energy emission, lack of Li I λ6707 absorption, and spectral shape of 2MASS 0122-2439 B suggest a range of ~10-120 Myr is possible. The age and luminosity of 2MASS 0122-2439 B fall in a strip where "hot-start" evolutionary model mass tracks overlap as a result of deuterium burning. Several known substellar companions also fall in this region (2MASS J0103-5515 ABb, AB Pic b, κ And b, G196-3 B, SDSS 2249+0044 B, LP 261-75 B, HD 203030 B, and HN Peg B), but their dual-valued mass predictions have largely been unrecognized. The implied mass of 2MASS 0122-2439 B is ≈12-13 M Jup or ≈22-27 M Jup if it is an AB Dor member, or possibly as low as 11 M Jup if the wider age range is adopted. Evolutionary models predict an effective temperature for 2MASS 0122-2439 B that corresponds to spectral types near the L/T transition (≈1300-1500 K) for field objects. However, we find a mid-L near-infrared spectral type, indicating that 2MASS 0122-2439 B represents another case of photospheric dust being retained to cooler temperatures at low surface gravities, as seen in the spectra of young (8-30 Myr) planetary

  14. Nonlinear Dynamics of Rotating Multi-Component Pair Plasmas and e-p-i Plasmas

    Science.gov (United States)

    Kourakis, Ioannis; Moslem, Waleed M.; Abdelsalam, Usama M.; Sabry, Refaat; Shukla, Padma Kant

    The propagation of small amplitude stationary profile nonlinear electrostatic excitations in a pair plasma is investigated, mainly drawing inspiration from experiments on fullerene pair-ion plasmas. Two distinct pair ion species are considered of opposite polarity and same mass, in addition to a massive charged background species, which is assumed to be stationary, given the frequency scale of interest. In the pair-ion context, the third species is thought of as a background defect (e.g. charged dust) component. On the other hand, the model also applies formally to electron-positron-ion (e-p-i) plasmas, if one neglects electron-positron annihilation. A two-fluid plasma model is employed, incorporating both Lorentz and Coriolis forces, thus taking into account the interplay between the gyroscopic (Larmor) frequency ωc and the (intrinsic) plasma rotation frequency Ω0. By employing a multi-dimensional reductive perturbation technique, a Zakharov-Kuznetsov (ZK) type equation is derived for the evolution of the electric potential perturbation. Assuming an arbitrary direction of propagation, with respect to the magnetic field, we derive the exact form of nonlinear solutions, and study their characteristics. A parametric analysis is carried out, as regards the effect of the dusty plasma composition (background number density), species temperature(s) and the relative strength of rotation to Larmor frequencies. It is shown that the Larmor and mechanical rotation affect the pulse dynamics via a parallel-to-transverse mode coupling diffusion term, which in fact diverges at ωc → ±2Ω0. Pulses collapse at this limit, as nonlinearity fails to balance dispersion. The analysis is complemented by investigating critical plasma compositions, in fact near-symmetric (T- ≈ T+) “pure” (n- ≈ n+) pair plasmas, i.e. when the concentration of the 3rd background species is negligible, case in which the (quadratic) nonlinearity vanishes, so one needs to resort to higher order

  15. Detection of the dusty torus in AGN with COMIC, the new infrared camera dedicated to the ESO adaptive optics system.

    Science.gov (United States)

    Marco, Olivier

    1997-10-01

    High angular resolution observation has greatly benefitted from adaptive optic systems working in the infrared. The COMIC camera, the second camera dedicated to ADONIS, the ESO 3.60 meter telescope adaptive optics system, allows observation in the spectral range 3-5 micron at the diffraction limit of the telescope. The characterization of the camera at the Meudon and Grenoble laboratories, then its performances determination on the sky in Chile constitute the first part of this dissertation. A new method for evaluating the limiting magnitudes is proposed which takes into account the various contributions to the detectivity loss between laboratory testing and real condition observations. This approach can be transferred to any other case where a priori observing conditions are known ( Strehl ratio or seeing ). Study of the central region of Active Galactic Nuclei (~1 arcsec) requires high angular resolution. In particular, warm and hot dust is emissive in the 1-5 micron spectral region. Thus, adaptive optics observations are well suited to AGN observation. It is predicted that the central engine and its neighboring environment are embedded within an optically thin dusty/molecular torus which may, along some lines of sight, obscure and even fully hide the nuclear emission leading to distinct observational properties for objects supposed to be identical. Observations made with ADONIS & COMIC of NGC7469 and NGC1068 have shown large amounts of dust located in the torus but also mixed with gas from the narrow line emission region. The high angular resolution achieved has allowed the determination of the dust temperature, mass and spatial distribution around the AGN central engine. These results are in agreement with several torus models and could help to constrain them.

  16. The Herschel Planetary Nebula Survey (HerPlaNS): A Comprehensive Dusty Photoionization Model of NGC6781.

    Science.gov (United States)

    Otsuka, Masaaki; Ueta, Toshiya; van Hoof, Peter A M; Sahai, Raghvendra; Aleman, Isabel; Zijlstra, Albert A; Chu, You-Hua; Villaver, Eva; Leal-Ferreira, Marcelo L; Kastner, Joel; Szczerba, Ryszard; Exter, Katrina M

    2017-08-01

    We perform a comprehensive analysis of the planetary nebula (PN) NGC 6781 to investigate the physical conditions of each of its ionized, atomic, and molecular gas and dust components and the object's evolution, based on panchromatic observational data ranging from UV to radio. Empirical nebular elemental abundances, compared with theoretical predictions via nucleosynthesis models of asymptotic giant branch (AGB) stars, indicate that the progenitor is a solar-metallicity, 2.25-3.0 M ⊙ initial-mass star. We derive the best-fit distance of 0.46 kpc by fitting the stellar luminosity (as a function of the distance and effective temperature of the central star) with the adopted post-AGB evolutionary tracks. Our excitation energy diagram analysis indicates high-excitation temperatures in the photodissociation region (PDR) beyond the ionized part of the nebula, suggesting extra heating by shock interactions between the slow AGB wind and the fast PN wind. Through iterative fitting using the Cloudy code with empirically derived constraints, we find the best-fit dusty photoionization model of the object that would inclusively reproduce all of the adopted panchromatic observational data. The estimated total gas mass (0.41 M ⊙ ) corresponds to the mass ejected during the last AGB thermal pulse event predicted for a 2.5 M ⊙ initial-mass star. A significant fraction of the total mass (about 70%) is found to exist in the PDR, demonstrating the critical importance of the PDR in PNe that are generally recognized as the hallmark of ionized/H + regions.

  17. SUB-KILOPARSEC IMAGING OF COOL MOLECULAR GAS IN TWO STRONGLY LENSED DUSTY, STAR-FORMING GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Spilker, J. S.; Marrone, D. P. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Aravena, M. [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile); Béthermin, M.; Breuck, C. de [European Southern Observatory, Karl Schwarzschild Straße 2, D-85748 Garching (Germany); Bothwell, M. S. [Cavendish Laboratory, University of Cambridge, JJ Thompson Ave, Cambridge CB3 0HA (United Kingdom); Carlstrom, J. E. [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Chapman, S. C.; Rotermund, K. M. [Dalhousie University, Halifax, Nova Scotia (Canada); Collier, J. D.; Galvin, T.; Grieve, K.; O’Brien, A. [University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751 (Australia); Fassnacht, C. D. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Gonzalez, A. H.; Ma, J. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); González-López, J. [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Hezaveh, Y. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Malkan, M., E-mail: jspilker@as.arizona.edu [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); and others

    2015-10-01

    We present spatially resolved imaging obtained with the Australia Telescope Compact Array (ATCA) of three CO lines in two high-redshift gravitationally lensed dusty star-forming galaxies, discovered by the South Pole Telescope. Strong lensing allows us to probe the structure and dynamics of the molecular gas in these two objects, at z = 2.78 and z = 5.66, with effective source-plane resolution of less than 1 kpc. We model the lensed emission from multiple CO transitions and the dust continuum in a consistent manner, finding that the cold molecular gas as traced by low-J CO always has a larger half-light radius than the 870 μm dust continuum emission. This size difference leads to up to 50% differences in the magnification factor for the cold gas compared to dust. In the z = 2.78 galaxy, these CO observations confirm that the background source is undergoing a major merger, while the velocity field of the other source is more complex. We use the ATCA CO observations and comparable resolution Atacama Large Millimeter/submillimeter Array dust continuum imaging of the same objects to constrain the CO–H{sub 2} conversion factor with three different procedures, finding good agreement between the methods and values consistent with those found for rapidly star-forming systems. We discuss these galaxies in the context of the star formation—gas mass surface density relation, noting that the change in emitting area with observed CO transition must be accounted for when comparing high-redshift galaxies to their lower redshift counterparts.

  18. STELLAR MASSES AND STAR FORMATION RATES OF LENSED, DUSTY, STAR-FORMING GALAXIES FROM THE SPT SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jingzhe; Gonzalez, Anthony H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Spilker, J. S.; Marrone, D. P. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Strandet, M. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69 D-53121 Bonn (Germany); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Aravena, M. [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile); Béthermin, M.; Breuck, C. de; Gullberg, B. [European Southern Observatory, Karl Schwarzschild Straße 2, D-85748 Garching (Germany); Bothwell, M. S. [Cavendish Laboratory, University of Cambridge, JJ Thompson Avenue, Cambridge CB3 0HA (United Kingdom); Brodwin, M. [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Chapman, S. C. [Dalhousie University, Halifax, Nova Scotia (Canada); Fassnacht, C. D. [Department of Physics, University of California, One Shields Avenue, Davis, CA 95616 (United States); Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Hezaveh, Y. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Malkan, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Saliwanchik, B. R., E-mail: jingzhema@ufl.edu [Department of Physics, Case Western Reserve University, Cleveland, OH 44106 (United States); and others

    2015-10-10

    To understand cosmic mass assembly in the universe at early epochs, we primarily rely on measurements of the stellar masses and star formation rates (SFRs) of distant galaxies. In this paper, we present stellar masses and SFRs of six high-redshift (2.8 ≤ z ≤ 5.7) dusty, star-forming galaxies (DSFGs) that are strongly gravitationally lensed by foreground galaxies. These sources were first discovered by the South Pole Telescope (SPT) at millimeter wavelengths and all have spectroscopic redshifts and robust lens models derived from Atacama Large Millimeter/submillimeter Array observations. We have conducted follow-up observations to obtain multi-wavelength imaging data using the Hubble Space Telescope (HST), Spitzer, Herschel, and the Atacama Pathfinder EXperiment. We use the high-resolution HST/Wide Field Camera 3 images to disentangle the background source from the foreground lens in Spitzer/IRAC data. The detections and upper limits provide important constraints on the spectral energy distributions (SEDs) for these DSFGs, yielding stellar masses, IR luminosities, and SFRs. The SED fits of six SPT sources show that the intrinsic stellar masses span a range more than one order of magnitude with a median value ∼5 ×10{sup 10} M{sub ⊙}. The intrinsic IR luminosities range from 4 × 10{sup 12} L{sub ⊙} to 4 × 10{sup 13} L{sub ⊙}. They all have prodigious intrinsic SFRs of 510–4800 M{sub ⊙} yr{sup −1}. Compared to the star-forming main sequence (MS), these six DSFGs have specific SFRs that all lie above the MS, including two galaxies that are a factor of 10 higher than the MS. Our results suggest that we are witnessing ongoing strong starburst events that may be driven by major mergers.

  19. Mathematical modelling of nonlinear thermal radiation effects on EMHD peristaltic pumping of viscoelastic dusty fluid through a porous medium duct

    Directory of Open Access Journals (Sweden)

    M.M. Bhatti

    2017-06-01

    Full Text Available Biologically-inspired propulsion systems are currently receiving significant interest in the aerospace sector. Since many spacecraft propulsion systems operate at high temperatures, thermal radiation is important as a mode of heat transfer. Motivated by these developments, in the present article, the influence of nonlinear thermal radiation (via the Rosseland diffusion flux model has been studied on the laminar, incompressible, dissipative EMHD (Electro-magneto-hydrodynamic peristaltic propulsive flow of a non-Newtonian (Jefferys viscoelastic dusty fluid containing solid particles through a porous planar channel. The fluid is electrically-conducting and a constant static magnetic field is applied transverse to the flow direction (channel walls. Slip effects are also included. Magnetic induction effects are neglected. The mathematical formulation is based on continuity, momentum and energy equations with appropriate boundary conditions, which are simplified by neglecting the inertial forces and taking the long wavelength and lubrication approximations. The boundary value problem is then rendered non-dimensional with appropriate variables and the resulting system of reduced ordinary differential equations is solved analytically. The impact of various emerging parameters dictating the non-Newtonian propulsive flow i.e. Prandtl number, radiation parameter, Hartmann number, permeability parameter, Eckert number, particle volume fraction, electric field and slip parameter are depicted graphically. Increasing particle volume fraction is observed to suppress temperature magnitudes. Furthermore the computations demonstrate that an increase in particle volume fraction reduces the pumping rate in retrograde pumping region whereas it causes the opposite effect in the co-pumping region. The trapping mechanism is also visualized with the aid of streamline contour plots. Increasing thermal radiation elevates temperatures. Increasing Hartmann (magnetic body

  20. Double Layers: Potential Formation and Related Nonlinear Phenomena in Plasmas: Proceedings of the 5th Symposium

    Science.gov (United States)

    Iizuka, S.

    1998-02-01

    The Table of Contents for the book is as follows: * PREFACE * INTERNATIONAL SCIENTIFIC COMMITTEE * LOCAL ORGANIZING COMMITTEE AT TOHOKU UNIVERSITY * CHAPTER 1: DOUBLE LAYERS, SHEATHS, AND POTENTIAL STRUCTURES * 1.1 Double Layers * On Fluid Models of Stationary, Acoustic Double Layers (Invited) * Particle Simulation of Double Layer (Invited) * Space-Time Dependence of Non-Steady Double Layers * The Role of Low Energy Electrons for the Generation of Anode Double Layers in Glow Discharges * Arbitrary Amplitude Ion-Acoustic Double Layers in a Dusty Plasma * 1.2 Sheaths * Bounded Plasma Edge Physics as Observed from Simulations in 1D and 2D (Invited) * Control of RF Sheath Structure in RF Diode Discharge * Observation of Density Gradients with Fine Structures and Low Frequency Wave Excitation at the Plasma-Sheath Boundary * Double Sheath Associated with an Electron Emission to a Plasma Containing Negative Ions * Sheath Edge and Floating Potential for Multi-Species Plasmas Including Dust Particles * 1.3 Potential Structures and Oscillations * Potential Structure Formed at a Constriction of a DC He Positive Column and its Coupling with Ionization Wave * Potential Structure in a New RF Magnetron Device with a Hollow Electrode * Potential Disruption in a RF Afterglow Electronegative Plasma * Potential Oscillation in a Strongly Asymmetry RF Discharge Containing Negative Ions * Effects of External Potential Control on Coulomb Dust Behavior * Potential Structure of Carbon Arc Discharge for High-Yield Fullerenes Formation * Control of Axial and Radial Potential Profiles in Tandem Mirrors (Invited) * CHAPTER 2: FIELD-ALIGNED ELECTRIC FIELDS AND RELATED PARTICLE ACCELERATIONS * 2.1 Field-Aligned Potential Formation * Formation of Large Potential Difference in a Plasma Flow along Converging Magnetic Field Lines (Invited) * Presheath Formation in front of an Oblique End-Plate in a Magnetized Sheet Plasma * Plasma Potential Formation Due to ECRH in a Magnetic Well * Electrostatic

  1. PLASMA DEVICE

    Science.gov (United States)

    Gow, J.D.; Wilcox, J.M.

    1961-12-26

    A device is designed for producing and confining highenergy plasma from which neutrons are generated in copious quantities. A rotating sheath of electrons is established in a radial electric field and axial magnetic field produced within the device. The electron sheath serves as a strong ionizing medium to gas introdueed thereto and also functions as an extremely effective heating mechanism to the resulting plasma. In addition, improved confinement of the plasma is obtained by ring magnetic mirror fields produced at the ends of the device. Such ring mirror fields are defined by the magnetic field lines at the ends of the device diverging radially outward from the axis of the device and thereafter converging at spatial annular surfaces disposed concentrically thereabout. (AFC)

  2. Dust Ion-Acoustic Shock Waves in a Multicomponent Magnetorotating Plasma

    Science.gov (United States)

    Kaur, Barjinder; Saini, N. S.

    2018-02-01

    The nonlinear properties of dust ion-acoustic (DIA) shock waves in a magnetorotating plasma consisting of inertial ions, nonextensive electrons and positrons, and immobile negatively charged dust are examined. The effects of dust charge fluctuations are not included in the present investigation, but the ion kinematic viscosity (collisions) is a source of dissipation, leading to the formation of stable shock structures. The Zakharov-Kuznetsov-Burgers (ZKB) equation is derived using the reductive perturbation technique, and from its solution the effects of different physical parameters, i.e. nonextensivity of electrons and positrons, kinematic viscosity, rotational frequency, and positron and dust concentrations, on the characteristics of shock waves are examined. It is observed that physical parameters play a very crucial role in the formation of DIA shocks. This study could be useful in understanding the electrostatic excitations in dusty plasmas in space (e.g. interstellar medium).

  3. Dust in the Ion Wind: A Model for Plasma Dust Particle Dynamics

    International Nuclear Information System (INIS)

    RILEY, MERLE E.

    2001-01-01

    A model is developed for the forces acting on a micrometer-size particle (dust) suspended within a plasma sheath. The significant forces acting on a single particle are gravity, neutral gas drag, electric field, and the ion wind due to ion flow to the electrode. It is shown that an instability in the small-amplitude dust oscillation might exist if the conditions are appropriate. In such a case the forcing term due to the ion wind exceeds the damping of the gas drag. The basic physical cause for the instability is that the ion wind force can be a decreasing function of the relative ion-particle velocity. However it seems very unlikely the appropriate conditions for instability are present in typical dusty plasmas

  4. Dust in fusion devices-a multi-faceted problem connecting high- and low-temperature plasma physics

    International Nuclear Information System (INIS)

    Winter, J

    2004-01-01

    Small particles with sizes between a few nanometers and a few 10 μm (dust) are formed in fusion devices by plasma-surface interaction processes. Though it is not a major problem today, dust is considered a problem that could arise in future long pulse fusion devices. This is primarily due to its radioactivity and due to its very high chemical reactivity. Dust formation is particularly pronounced when carbonaceous wall materials are used. Dust particles can be transported in the tokamak over significant distances. Radioactivity leads to electrical charging of dust and to its interaction with plasmas and electric fields. This may cause interference with the discharge but may also result in options for particle removal. This paper discusses some of the multi-faceted problems using information both from fusion research and from low-temperature dusty plasma work

  5. Electron plasma waves and plasma resonances

    International Nuclear Information System (INIS)

    Franklin, R N; Braithwaite, N St J

    2009-01-01

    In 1929 Tonks and Langmuir predicted of the existence of electron plasma waves in an infinite, uniform plasma. The more realistic laboratory environment of non-uniform and bounded plasmas frustrated early experiments. Meanwhile Landau predicted that electron plasma waves in a uniform collisionless plasma would appear to be damped. Subsequent experimental work verified this and revealed the curious phenomenon of plasma wave echoes. Electron plasma wave theory, extended to finite plasmas, has been confirmed by various experiments. Nonlinear phenomena, such as particle trapping, emerge at large amplitude. The use of electron plasma waves to determine electron density and electron temperature has not proved as convenient as other methods.

  6. MONSTER IN THE DARK: THE ULTRALUMINOUS GRB 080607 AND ITS DUSTY ENVIRONMENT

    International Nuclear Information System (INIS)

    Perley, D. A.; Morgan, A. N.; Miller, A. A.; Bloom, J. S.; Cenko, S. B.; Li, W.; Filippenko, A. V.; Butler, N. R.; Christian, P.; Updike, A.; Hartmann, D. H.; Yuan, F.; Akerlof, C. W.; Prochaska, J. X.; Kann, D. A.; Tanvir, N. R.; Levan, A. J.; Milne, P.; Rujopakarn, W.; Rykoff, E. S.

    2011-01-01

    We present early-time optical through infrared photometry of the bright Swift gamma-ray burst (GRB) 080607, starting only 6 s following the initial trigger in the rest frame. Complemented by our previously published spectroscopy, this high-quality photometric data set allows us to solve for the extinction properties of the redshift 3.036 sightline, giving perhaps the most detailed information to date on the ultraviolet continuum absorption properties of any sightline outside our Local Group. The extinction properties are not adequately modeled by any ordinary extinction template (including the average Milky Way, Large Magellanic Cloud, and Small Magellanic Cloud curves), partially because the 2175 A feature (while present) is weaker by about a factor of two than when seen under similar circumstances locally. However, the spectral energy distribution is exquisitely fitted by the more general Fitzpatrick and Massa parameterization of Local-Group extinction, putting it in the same family as some peculiar Milky Way extinction curves. After correcting for this (considerable, A V = 3.3 ± 0.4 mag) extinction, GRB 080607 is revealed to have been among the most optically luminous events ever observed, comparable to the naked-eye burst GRB 080319B. Its early peak time (t rest 600), while the extreme luminosity may be explained in part by a large circumburst density. Only because of its early high luminosity could the afterglow of GRB 080607 be studied in such detail in spite of the large attenuation and great distance, making this burst an excellent prototype for the understanding of other highly obscured extragalactic objects, and of the class of 'dark' GRBs in particular.

  7. Plasma source ion implantation

    International Nuclear Information System (INIS)

    Conrad, J.R.; Forest, C.

    1986-01-01

    The authors' technique allows the ion implantation to be performed directly within the ion source at higher currents without ion beam extraction and transport. The potential benefits include greatly increased production rates (factors of 10-1000) and the ability to implant non-planar targets without rastering or shadowing. The technique eliminates the ion extractor grid set, beam raster equipment, drift space and target manipulator equipment. The target to be implanted is placed directly within the plasma source and is biased to a large negative potential so that plasma ions gain energy as they accelerate through the potential drop across the sheath that forms at the plasma boundary. Because the sheath surrounds the target on all sides, all surfaces of the target are implanted without the necessity to raster the beam or to rotate the target. The authors have succeeded in implanting nitrogen ions in a silicon target to the depths and concentrations required for surface treatment of materials like stainless steel and titanium alloys. They have performed ESCA measurements of the penetration depth profile of a silicon target that was biased to 30 kV in a nitrogen discharge plasma. Nitrogen ions were implanted to a depth of 700A at a peak concentration of 30% atomic. The measured profile is quite similar to a previously obtained profile in titanium targets with conventional techniques

  8. Plasma focus matching conditions

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.; Elkhalafawy, T.A.

    1988-01-01

    A snow-plough and slug models have been used to obtain the optimum matching conditions of the plasma in the focus. The dimensions of the plasma focus device are, inner electrode radius = 2 cm, outer electrode radius = 5.5 cm, and its length = 8 cm. It was found that the maximum magnetic energy of 12.26 kJ has to be delivered to plasma focus whose density is 10 19 /cm 3 at focusing time of 2.55 μs and with total external inductance of 24.2 n H. The same method is used to evaluate the optimum matching conditions for the previous coaxial discharge system which had inner electrode radius = 1.6 cm, outer electrode radius = 3.3 cm and its length = 31.5 cm. These conditions are charging voltage = 12 kV, capacity of the condenser bank = 430 μf, plasma focus density = 10 19 /cm 3 focusing time = 8 μs and total external inductance = 60.32 n H.3 fig., 2 tab

  9. Plasma physics and engineering

    CERN Document Server

    Fridman, Alexander

    2011-01-01

    Part I: Fundamentals of Plasma Physics and Plasma ChemistryPlasma in Nature, in the Laboratory, and in IndustryOccurrence of Plasma: Natural and Man MadeGas DischargesPlasma Applications, Plasmas in IndustryPlasma Applications for Environmental ControlPlasma Applications in Energy ConversionPlasma Application for Material ProcessingBreakthrough Plasma Applications in Modern TechnologyElementary Processes of Charged Species in PlasmaElementary Charged Particles in Plasma and Their Elastic and Inelastic CollisionsIonization ProcessesMechanisms of Electron Losses: The Electron-Ion RecombinationEl

  10. Burning plasmas

    International Nuclear Information System (INIS)

    Furth, H.P.; Goldston, R.J.; Zweben, S.J.

    1990-10-01

    The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R ampersand D areas that need to be addressed on the way to a fusion power demonstration

  11. Burning plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Furth, H.P.; Goldston, R.J.; Zweben, S.J. (Princeton Univ., NJ (USA). Plasma Physics Lab.); Sigmar, D.J. (Massachusetts Inst. of Tech., Cambridge, MA (USA))

    1990-10-01

    The fraction of fusion-reaction energy that is released in energetic charged ions, such as the alpha particles of the D-T reaction, can be thermalized within the reacting plasma and used to maintain its temperature. This mechanism facilitates the achievement of very high energy-multiplication factors Q, but also raises a number of new issues of confinement physics. To ensure satisfactory reaction operation, three areas of energetic-ion interaction need to be addressed: single-ion transport in imperfectly symmetric magnetic fields or turbulent background plasmas; energetic-ion-driven (or stabilized) collective phenomena; and fusion-heat-driven collective phenomena. The first of these topics is already being explored in a number of tokamak experiments, and the second will begin to be addressed in the D-T-burning phase of TFTR and JET. Exploration of the third topic calls for high-Q operation, which is a goal of proposed next-generation plasma-burning projects. Planning for future experiments must take into consideration the full range of plasma-physics and engineering R D areas that need to be addressed on the way to a fusion power demonstration.

  12. PREFACE: Low temperature Plasma in the Processes of Functional Coating Preparation

    Science.gov (United States)

    Gali Yunusovich, Dautov; Kashapov Faikovich, Nail; Larionov, Viktor; Gerfanovich Zaripov, Renat; Galyautdinov Tagirovich, Raphael; Ilnaz, Fayrushin; Ramil Nailevich, Kashapov

    2013-12-01

    In November 2013 the V Republican Scientific Technical Conference 'Low-temperature plasma during the deposition of functional coatings' was held in Kazan. The Conference took place from 4-7 November at the Academy of Sciences of the Republic of Tatarstan and Kazan Federal University chaired by a member of the Academy of Sciences of the Republic of Tatarstan Nail Kashapov, Professor, Doctor of Technical Science, and a member of the Scientific and Technical Council of the Ministry of Economy of the Republic of Tatarstan. At the conference, the participants were offered a wide range of issues affecting the theoretical and computational aspects of the research problems in the physics and technology of low-temperature plasma. There was also a whole series of works devoted to the study of thin films, obtained by low-temperature plasma. For the second year at this conference, work dedicated to the related field of pulsation combustion and low- temperature plasma was considered. In addition much interest is devoted to reports on the exploration of gas discharges with liquid electrolytic electron trodes and the study of dusty plasmas. The VI All-Russian Conference 'Low-temperature plasma during the deposition of functional coatings', an extended version with international participation, is scheduled to take place in November 2014. Nail Kashapov Editor

  13. On the rogue waves propagation in non-Maxwellian complex space plasmas

    Energy Technology Data Exchange (ETDEWEB)

    El-Tantawy, S. A., E-mail: samireltantawy@yahoo.com; El-Awady, E. I., E-mail: eielawady@hotmail.com [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt); Tribeche, M., E-mail: mouloudtribeche@yahoo.fr, E-mail: mtribeche@usthb.dz [Plasma Physics Group, Theoretical Physics Laboratory, Faculty of Physics, University of Bab-Ezzouar, USTHB, BP 32, El Alia, Algiers 16111 (Algeria)

    2015-11-15

    The implications of the non-Maxwellian electron distributions (nonthermal/or suprathermal/or nonextensive distributions) are examined on the dust-ion acoustic (DIA) rogue/freak waves in a dusty warm plasma. Using a reductive perturbation technique, the basic set of fluid equations is reduced to a nonlinear Schrödinger equation. The latter is used to study the nonlinear evolution of modulationally unstable DIA wavepackets and to describe the rogue waves (RWs) propagation. Rogue waves are large-amplitude short-lived wave groups, routinely observed in space plasmas. The possible region for the rogue waves to exist is defined precisely for typical parameters of space plasmas. It is shown that the RWs strengthen for decreasing plasma nonthermality and increasing superthermality. For nonextensive electrons, the RWs amplitude exhibits a bit more complex behavior, depending on the entropic index q. Moreover, our numerical results reveal that the RWs exist with all values of the ion-to-electron temperature ratio σ for nonthermal and superthermal distributions and there is no limitation for the freak waves to propagate in both two distributions in the present plasma system. But, for nonextensive electron distribution, the bright- and dark-type waves can propagate in this case, which means that there is a limitation for the existence of freak waves. Our systematic investigation should be useful in understanding the properties of DIA solitary waves that may occur in non-Maxwellian space plasmas.

  14. Electrosurgical plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Stalder, Kenneth R; McMillen, Donald F; Woloszko, Jean [ArthroCare Corp., Sunnyvale, CA 94085-3523 (United States)

    2005-06-07

    Electrosurgical medical devices based on repetitively pulsed nonequilibrium micron-scale to millimetre-scale plasma discharges in saline solutions are described. The formation of vapour layers (bubbles) around active electrodes appears to be a common feature at moderate (<300 V rms) voltages, and dissociation, excitation and ionization of the vapour in these bubbles produces chemical conditions that are thought to be the source of beneficial tissue removal and treatment. Experimental data are discussed, as are the results of modelling efforts of the plasma chemistry. Hydroxyl radicals, hydrogen atoms and other species are observed spectroscopically and their interactions with collagen, a common component of tissue encountered in surgical situations, are considered. Several pathways by which hydroxyl radicals interacting with collagen can lead to tissue removal are discussed.

  15. MISALIGNMENT OF THE JET AND THE NORMAL TO THE DUSTY TORUS IN THE BROAD ABSORPTION LINE QSO FIRST J155633.8+351758

    International Nuclear Information System (INIS)

    Reynolds, Cormac; Punsly, Brian; O'Dea, Christopher P.

    2013-01-01

    We performed Very Long Baseline Array observations of the broad absorption line quasar FIRST J155633.8+351758, ''the first radio loud BALQSO''. Our observations at 15.3 GHz partially resolved a secondary component at position angle (P.A.) ≈35°. We combine this determination of the radio jet projection on the sky plane, with the constraint that the jet is viewed within 14.°3 of the line of sight (as implied by the high variability brightness temperature) and with the P.A. of the optical/UV continuum polarization in order to study the quasar geometry. Within the context of the standard model, the data indicates a ''dusty torus'' (scattering surface) with a symmetry axis tilted relative to the accretion disk normal and a polar broad absorption line outflow aligned with the accretion disk normal. We compare this geometry to that indicated by the higher resolution radio data, brightness temperature, and optical/UV continuum polarization P.A. of a similar high optical polarization BALQSO, Mrk 231. A qualitatively similar geometry is found in these two polar BALQSOs; the continuum polarization is determined primarily by the tilt of the dusty torus

  16. Plasma physics

    CERN Document Server

    Cairns, R A

    1985-01-01

    This book is intended as an introduction to plasma physics at a level suitable for advanced undergraduates or beginning postgraduate students in physics, applied mathematics or astrophysics. The main prerequisite is a knowledge of electromagnetism and of the associated mathematics of vector calculus. SI units are used throughout. There is still a tendency amongst some plasma physics researchers to· cling to C.g.S. units, but it is the author's view that universal adoption of SI units, which have been the internationally agreed standard since 1960, is to be encouraged. After a short introductory chapter, the basic properties of a plasma con­ cerning particle orbits, fluid theory, Coulomb collisions and waves are set out in Chapters 2-5, with illustrations drawn from problems in nuclear fusion research and space physics. The emphasis is on the essential physics involved and (he theoretical and mathematical approach has been kept as simple and intuitive as possible. An attempt has been made to draw attention t...

  17. Autophagy in plasma cell pathophysiology

    Directory of Open Access Journals (Sweden)

    Laura eOliva

    2014-03-01

    Full Text Available Plasma cells are the effectors responsible for antibody-mediated immunity. They differentiate from B lymphocytes through a complete remodeling of their original structure and function. Stress is a constitutive element of plasma cell differentiation. Macroautophagy, conventionally referred to as autophagy, is a conserved lysosomal recycling strategy that integrates cellular metabolism and enables adaptation to stress. In metazoa, autophagy plays diverse roles in cell differentiation. Recently, a number of autophagic functions have been recognized in innate and adaptive immunity, including clearance of intracellular pathogens, inflammasome regulation, lymphocyte ontogenesis, and antigen presentation. We identified a previously unrecognized role played by autophagy in plasma cell differentiation and activity. Following B cell activation, autophagy moderates the expression of the transcriptional repressor Blimp-1 and immunoglobulins through a selective negative control exerted on the size of the endoplasmic reticulum and its stress signaling response, including the essential plasma cell transcription factor, XBP-1. This containment of plasma cell differentiation and function, i.e., antibody production, is essential to optimize energy metabolism and viability. As a result, autophagy sustains antibody responses in vivo. Moreover, autophagy is an essential intrinsic determinant of long-lived plasma cells in their as yet poorly understood bone marrow niche. In this essay, we discuss these findings in the context of the established biological functions of autophagy, and their manifold implications for adaptive immunity and plasma cell diseases, in primis multiple myeloma.

  18. Effect of the raw materials processing on their dustiness; Efecto del procesado de materias primas sobre su poder de emisión de polvo

    Energy Technology Data Exchange (ETDEWEB)

    López Lilaoa, A.; Juárezb, M.; Sanfelix Fornera, V.; Mallol Gascha, G.; Monfort Gimeno, E.

    2017-11-01

    During the handling and/or processing of powdered materials in the CERAMICS INDUSTRY, one of the most important risks regarding the environmental and occupational health is the potential generation of dust. In this regard, a parameter of great interest is the dustiness of the processed materials; this parameter quantifies the tendency of the powdered materials to generate dust when handled. In this study, to determine the dustiness of a ceramic raw material composition (mixture of the body raw materials), the continuous drop method has been used. This test apparatus was selected because it is considered to better simulate how ceramic materials are handled in the CERAMICS INDUSTRY. The obtained results show that the dustiness of the same ceramic composition exhibits significant changes during the manufacturing process, depending on the presentation form. In this regard, the dry milling sample presents the highest dustiness, which can be significantly reduced (>75%) applying the the moisturization and agglomeration. The obtained results also shown that the best presentation form, regarding the minimization of the dust generation, is achieved in the spray-drying process, where the dustiness is reduced by 95%. [Spanish] En la manipulación y/o procesado de materiales pulverulentos en la industria cerámica, uno de los riesgos más importantes desde el punto de vista ambiental y de higiene laboral es la generación de polvo ambiental. En este sentido, un parámetro de gran interés es el poder de emisión de polvo, que cuantifica la tendencia de los materiales pulverulentos a generar polvo cuando se manipulan. En este trabajo, para determinar el poder de emisión de polvo de una composición cerámica (mezcla de materias primas empleada para la fabricación de baldosas cerámicas) se ha empleado un método de caída continua. Este método se ha seleccionado por ser el que mejor representa las operaciones de manipulación de materiales pulverulentos que tienen lugar en

  19. Relativistic generalization of strong plasma turbulence

    International Nuclear Information System (INIS)

    Chian, A.C.-L.

    1982-01-01

    Two fundamental electrostatic modes of an unmagnetized plasma, namely, ion acoustic mode and Langumir mode are studied. Previous theories are generalized to include the effect of relativistic mass variations. The existence of relativistic ion acoustic solitons is demonstrated. In addition, it is shown that simple, relativistic Langumir solitons do not exist in a infinite plasma. (L.C.) [pt

  20. Correlations Between Seminal Plasma Hormones and Sperm ...

    African Journals Online (AJOL)

    Context: There is a complex relationship between seminal plasma hormone levels and infertility in men. Previous studies had shown no specific pattern in the serum or seminal plasma hormone profiles of men with infertility and it is debatable whether there is a need to perform routine seminal hormone assays in the ...

  1. Plasma shutdown device

    International Nuclear Information System (INIS)

    Hosogane, Nobuyuki; Nakayama, Takahide.

    1985-01-01

    Purpose: To prevent concentration of plasma currents to the plasma center upon plasma shutdown in a torus type thermonuclear device by the injection of fuels to the plasma center thereby prevent plasma disruption at the plasma center. Constitution: The plasma shutdown device comprises a plasma current measuring device that measures the current distribution of plasmas confined within a vacuum vessel and outputs a control signal for cooling the plasma center when the plasma currents concentrate to the plasma center and a fuel supply device that supplies fuels to the plasma center for cooling the center. The fuels are injected in the form of pellets into the plasmas. The direction and the velocity of the injection are set such that the pellets are ionized at the center of the plasmas. (Horiuchi, T.)

  2. Kinetic Theory of quasi-electrostatic waves in non-gyrotropic plasmas

    Science.gov (United States)

    Arshad, K.; Poedts, S.; Lazar, M.

    2017-12-01

    The orbital angular momentum (OAM) is a trait of helically phased light or helical (twisted) electric field. Lasers carrying orbital angular momentum (OAM) revolutionized many scientific and technological paradigms like microscopy, imaging and ionospheric radar facility to analyze three dimensional plasma dynamics in ionosphere, ultra-intense twisted laser pulses, twisted gravitational waves and astrophysics. This trend has also been investigated in plasma physics. Laguerre-Gaussian type solutions are predicted for magnetic tornadoes and Alfvénic tornadoes which exhibit spiral, split and ring-like morphologies. The ring shape morphology is ideal to fit the observed solar corona, solar atmosphere and Earth's ionosphere. The orbital angular momentum indicates the mediation of electrostatic and electromagnetic waves in new phenomena like Raman and Brillouin scattering. A few years ago, some new effects have been included in studies of orbital angular momentum in plasma regimes such as wave-particle interaction in the presence of helical electric field. Therefore, kinetic studies are carried out to investigate the Landau damping of the waves and growth of the instabilities in the presence helical electric field carrying orbital angular momentum for the Maxwellian distributed plasmas. Recently, a well suited approach involving a kappa distribution function has been adopted to model the twisted space plasmas. This leads to the development of new theoretical grounds for the study of Lorentzian or kappa distributed twisted Langmuir, ion acoustic, dust ion acoustic and dust acoustic modes. The quasi-electrostatic twisted waves have been studied now for the non-gyrotropic dusty plasmas in the presence of the orbital angular momentum of the helical electric field using Generalized Lorentzian or kappa distribution function. The Laguerre-Gaussian (LG) mode function is employed to decompose the perturbed distribution function and electric field into planar (longitudinal) and

  3. Nonlinear Electrostatic Wave Equations for Magnetized Plasmas

    DEFF Research Database (Denmark)

    Dysthe, K.B.; Mjølhus, E.; Pécseli, Hans

    1984-01-01

    The lowest order kinetic effects are included in the equations for nonlinear electrostatic electron waves in a magnetized plasma. The modifications of the authors' previous analysis based on a fluid model are discussed.......The lowest order kinetic effects are included in the equations for nonlinear electrostatic electron waves in a magnetized plasma. The modifications of the authors' previous analysis based on a fluid model are discussed....

  4. Exploring the dusty Universe

    Directory of Open Access Journals (Sweden)

    Borghese, F

    2005-11-01

    Full Text Available Dust is an ubiquitous inhabitant of the interstellar medium, and leaves an unmistakable signature in its optical properties, and physico-chemical evolution. Although there is little direct knowledge of the true nature of interstellar dust grains, strong evidences point toward the possibility that such grains are composites of many small monomers (mainly made of silicates and carbonaceous materials. We consider two different models of fluffy dust aggregates, occurring as result of ballistic particle-cluster and cluster-cluster aggregation, and a cluster with a Gaussian-like sphere size distribution. We study the optical properties of such composite structures through the multipole fields and the Transition Matrix approach. Our results show the severe limits of applicability of the effective medium theories. By comparing radiation and gravitational forces, we also infer some relevant insights into the dynamical evolution of composite grains in the Solar System. We finally explore the possible role of composite fluffy dust grains in igniting an extraterrestrial prebiotic chemistry.

  5. Properties of the Dense Plasma Produced in Plasma Focus

    International Nuclear Information System (INIS)

    Peacock, N.J.; Wilcock, P.D.; Speer, R.J.; Morgan, P.D.

    1969-01-01

    The plasma produced by the focus or quasi-cylindrical magnetic compression which occurs at the open end of a metal-walled, coaxial plasma gun has been studied, using the electrical waveforms and the electromagnetic and reaction particle, emission. The electromagnetic radiation in the XUV region of the spectrum has previously been briefly reported, and the present paper describes further more detailed analyses of the line emission at wavelengths shorter than 10 Å when impurities are added to the gas filling. The emission is characteristic of a plasma with a temperature of a few keV and a density greater than 10 19 cm -3 , while the appearance of optical transitions in highly stripped ions, e. g. A XVIII, gives a measure of the thermalization in the plasma. The stored electrical energy has been doubled and the scaling of the neutron emission with the applied voltage and the initial particle density is presented. The duration of the neutron and X-ray emission is considerably longer than the observed instability growth time in the plasma filament. Calculations of the mode of heating and the confinement of the plasma are compared with experimental observations. (author)

  6. PREFACE: VI Scientific Technical Conference on "Low-temperature plasma during the deposition of functional coatings"

    Science.gov (United States)

    2014-11-01

    The VI Republican Scientific Technical Conference "Low-temperature plasma during the deposition of functional coatings" took place from 4 to 7 November 2014 at the Academy of Sciences of the Republic of Tatarstan and the Kazan Federal University. The conference was chaired by a Member of the Academy of Sciences of the Republic of Tatarstan Nail Kashapov -Professor, Doctor of Technical Sciences- a member of the Scientific and Technical Council of the Ministry of Economy of the Republic of Tatarstan. At the conference, the participants discussed a wide range of issues affecting the theoretical and computational aspects of research problems in the physics and technology of low-temperature plasma. A series of works were devoted to the study of thin films obtained by low-temperature plasma. This year work dedicated to the related field of heat mass transfer in multiphase media and low-temperature plasma was also presented. Of special interest were reports on the exploration of gas discharges with liquid electrolytic electrotrodes and the study of dusty plasmas. Kashapov Nail, D.Sc., Professor (Kazan Federal University)

  7. Transport Theory for Plasmas that are Strongly Magnetized and Strongly Coupled

    Science.gov (United States)

    Baalrud, Scott; Daligault, Jerome

    2016-10-01

    Plasmas with components that are magnetized, strongly coupled, or both arise in a variety of frontier plasma physics experiments including magnetized dusty plasmas, nonneutral plasmas, magnetized ICF concepts, as well as from self-generated fields in ICF. Here, a species is considered strongly magnetized if the gyroradius is smaller than the spatial scale over which Coulomb interactions occur. A theory for transport properties is described that treats a wide range of both coupling and magnetization strengths. The approach is based on an extension of the recent effective potential transport theory to include a strong magnetic field. The underlying kinetic theory is based on an extension of the Boltzmann equation to include a strong magnetic field in the dynamics of binary scattering events. Corresponding magnetohydrodynamic equations are derived by solving the kinetic equation using a Chapman-Enskog like spectral method. Results are compared with classical molecular dynamics simulations of self-diffusion of the one component plasmas, and with simulations of parallel to perpendicular temperature equilibration of an initially anisotropic distribution. This material is based upon work supported by AFOSR Award FA9550-16-1-0221 and DOE OFES Award DE-SC0016159.

  8. A pulsed ‘plasma broom’ for dusting off surfaces on Mars

    Science.gov (United States)

    Ticoş, C. M.; Scurtu, A.; Ticoş, D.

    2017-06-01

    Dust is a challenge for the design and operation of equipment on the Martian surface, particularly for solar cells. An efficient and robust technique for removing dust and sand from surfaces immersed in CO2 at low pressure is presented. The working principle is based on a pulsed plasma jet produced between two coaxial electrodes biased at voltages between 1 and 2 kV. A demonstration is presented using dust particles whose chemical composition mimic the Mars soil. An array of connected photovoltaic cells fully covered with dust and sand is exposed to the plasma jet. The cells open circuit voltage is monitored in real-time thus providing the means to measure the dust removal efficiency. A good cleaning efficiency is attained after a few shots in a geometry where the plasma jet is directed perpendicularly to the dusty surface. The main advantage of this approach lies in the opportunity to apply it directly at about 5 Torr, the pressure of the Martian environment. A numerical evaluation shows that the plasma drag force on a dust particle is orders of magnitude higher than its weight depending on plasma density and flow speed, hence validating the principles of this cleaning technique.

  9. Maternal serum screening marker levels in women with a previous aneuploidy pregnancy.

    Science.gov (United States)

    Spencer, Kevin; Staboulidou, Ismini; De Jesus Cruz, Jader; Karagiannis, George; Nicolaides, Kypros H

    2009-12-01

    To re-evaluate in a larger cohort of patients if the maternal serum biochemical markers used in first trimester aneuploidy screening have the same marker distributions in pregnancies with a previous history of aneuploidy compared with those that have no previous history. Information related to previous pregnancy history is routinely recorded as part of first trimester screening in three centres King George, Kings College and Fetal Medicine Centre, London. From the database, records were extracted for women who had a previous pregnancy diagnosed with trisomies 13, 18 or 21. For each woman with a previous aneuploidy, five unaffected pregnancies in women of the same maternal age and with no previous aneuploidy pregnancy were selected as controls. A comparison was made between the marker distributions for pregnancy associated plasma protein-A (PAPP-A) and free beta-human chronic gonadotrophin (beta-hCG) amongst the cases and controls using nonparametric statistical tests. A series of 8240 controls were compared against group of 1032 cases with a previous trisomy 21, 293 with a previous trisomy 18 and 158 with a previous trisomy 13. Cases with multiple previous trisomies were excluded. There were no significant differences in the level of free beta-hCG; however, in cases of trisomy 21 and trisomy 13 the levels of PAPP-A were increased by 5 and 16%, respectively. Risk calculation algorithms may need to take account of the increased PAPP-A levels in women with a previous trisomy 21 or trisomy 13. Copyright (c) 2009 John Wiley & Sons, Ltd.

  10. Comprehensive Approaches to Multiphase Flows in Geophysics - Application to nonisothermal, nonhomogenous, unsteady, large-scale, turbulent dusty clouds I. Hydrodynamic and Thermodynamic RANS and LES Models

    Energy Technology Data Exchange (ETDEWEB)

    S. Dartevelle

    2005-09-05

    The objective of this manuscript is to fully derive a geophysical multiphase model able to ''accommodate'' different multiphase turbulence approaches; viz., the Reynolds Averaged Navier-Stokes (RANS), the Large Eddy Simulation (LES), or hybrid RANSLES. This manuscript is the first part of a larger geophysical multiphase project--lead by LANL--that aims to develop comprehensive modeling tools for large-scale, atmospheric, transient-buoyancy dusty jets and plume (e.g., plinian clouds, nuclear ''mushrooms'', ''supercell'' forest fire plumes) and for boundary-dominated geophysical multiphase gravity currents (e.g., dusty surges, diluted pyroclastic flows, dusty gravity currents in street canyons). LES is a partially deterministic approach constructed on either a spatial- or a temporal-separation between the large and small scales of the flow, whereas RANS is an entirely probabilistic approach constructed on a statistical separation between an ensemble-averaged mean and higher-order statistical moments (the so-called ''fluctuating parts''). Within this specific multiphase context, both turbulence approaches are built up upon the same phasic binary-valued ''function of presence''. This function of presence formally describes the occurrence--or not--of any phase at a given position and time and, therefore, allows to derive the same basic multiphase Navier-Stokes model for either the RANS or the LES frameworks. The only differences between these turbulence frameworks are the closures for the various ''turbulence'' terms involving the unknown variables from the fluctuating (RANS) or from the subgrid (LES) parts. Even though the hydrodynamic and thermodynamic models for RANS and LES have the same set of Partial Differential Equations, the physical interpretations of these PDEs cannot be the same, i.e., RANS models an averaged field, while LES simulates a

  11. In-depth study of moderately young but extremely red, very dusty substellar companion HD 206893B

    Science.gov (United States)

    Delorme, P.; Schmidt, T.; Bonnefoy, M.; Desidera, S.; Ginski, C.; Charnay, B.; Lazzoni, C.; Christiaens, V.; Messina, S.; D'Orazi, V.; Milli, J.; Schlieder, J. E.; Gratton, R.; Rodet, L.; Lagrange, A.-M.; Absil, O.; Vigan, A.; Galicher, R.; Hagelberg, J.; Bonavita, M.; Lavie, B.; Zurlo, A.; Olofsson, J.; Boccaletti, A.; Cantalloube, F.; Mouillet, D.; Chauvin, G.; Hambsch, F.-J.; Langlois, M.; Udry, S.; Henning, T.; Beuzit, J.-L.; Mordasini, C.; Lucas, P.; Marocco, F.; Biller, B.; Carson, J.; Cheetham, A.; Covino, E.; De Caprio, V.; Delboulbe, A.; Feldt, M.; Girard, J.; Hubin, N.; Maire, A.-L.; Pavlov, A.; Petit, C.; Rouan, D.; Roelfsema, R.; Wildi, F.

    2017-12-01

    Context. The substellar companion HD 206893b has recently been discovered by direct imaging of its disc-bearing host star with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. Aims: We investigate the atypical properties of the companion, which has the reddest near-infrared colours among all known substellar objects, either orbiting a star or isolated, and we provide a comprehensive characterisation of the host star-disc-companion system. Methods: We conducted a follow-up of the companion with adaptive optics imaging and spectro-imaging with SPHERE, and a multi-instrument follow-up of its host star. We obtain a R = 30 spectrum from 0.95 to 1.64 μm of the companion and additional photometry at 2.11 and 2.25 μm. We carried out extensive atmosphere model fitting for the companions and the host star in order to derive their age, mass, and metallicity. Results: We found no additional companion in the system in spite of exquisite observing conditions resulting in sensitivity to 6 MJup (2 MJup) at 0.5'' for an age of 300 Myr (50 Myr). We detect orbital motion over more than one year and characterise the possible Keplerian orbits. We constrain the age of the system to a minimum of 50 Myr and a maximum of 700 Myr, and determine that the host-star metallicity is nearly solar. The comparison of the companion spectrum and photometry to model atmospheres indicates that the companion is an extremely dusty late L dwarf, with an intermediate gravity (log g 4.5-5.0) which is compatible with the independent age estimate of the system. Conclusions: Though our best fit corresponds to a brown dwarf of 15-30 MJup aged 100-300 Myr, our analysis is also compatible with a range of masses and ages going from a 50 Myr 12 MJup planetary-mass object to a 50 MJup Hyades-age brown dwarf. Even though this companion is extremely red, we note that it is more probable that it has an intermediate gravity rather than the very low gravity that is often associated with

  12. Measurements of plasma position in TJ-I Tokamak

    International Nuclear Information System (INIS)

    Quin, J.; Ascasibar, E.; Navarro, A. P.; Ochando, M. A.; Pastor, I.; Pedrosa, M. A.; Rodriguez, L.; Sanchez, J.

    1994-01-01

    This report presents the experimental measurements of plasma position in TJ-I tokamak by using small magnetic probes. The basis of method has been described in our previous work (1) in which the plasma current is considered as a filament current. The observed relations between the disruptive instabilities and plasma displacements are also show here. (Author) 7 refs

  13. Whimsicality of multi-mode Hasegawa space-charge waves in a complex plasma containing collision-dominated electrons and streaming ions

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-09-01

    The influence of collision-dominated electrons on multi-mode Hasegawa space-charge waves are investigated in a complex plasma containing streaming ions. The dispersion relation for the multi-mode Hasegawa space-charge wave propagating in a cylindrical waveguide filled with dusty plasma containing collision-dominated electrons and streaming ions is derived by using the fluid equations and Poisson’s equation which lead to a Bessel equation. By the boundary condition, the roots of the Bessel function would characterize the property of space-charge wave propagation. It is found that two solutions exist for wave frequency, which are affected by the radius of waveguide and the roots of the Bessel function. The damping and growing modes are found to be enhanced by an increase of the radius. However, an increase of electron collision frequency would suppress the damping and the growing modes of the propagating space-charge wave in a cylindrical waveguide plasma.

  14. 22 CFR 40.91 - Certain aliens previously removed.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a result...

  15. Plasma volume changes during hypoglycaemia

    DEFF Research Database (Denmark)

    Hilsted, J; Bendtsen, F; Christensen, N J

    1990-01-01

    To investigate whether previously reported changes in venous blood volume and composition induced by acute hypoglycaemia in humans are representative for the entire body we measured erythrocyte 51Cr content, haematocrit, plasma volume, intravascular albumin content and transcapillary escape rate...... of albumin in arterial and venous blood in seven healthy subjects before and during insulin-induced hypoglycaemia. In both vascular sites blood 51Cr content and the haematocrit increased, plasma volume and intravascular albumin content decreased and the transcapillary escape rate of albumin increased during...

  16. Physics of a fusion plasma boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, B.K.

    1977-03-01

    A theoretical and computational study has been made of plasma phenomena occurring when a hot, dense plasma containing a transverse magnetic field is brought into sudden contact with a cold metal wall; thermal and magnetic boundary layers develop. The time evolution of the plasma temperature, pressure, the charged and neutral particle concentration, magnetic and electric field strengths, and the plasma current density in the neighborhood of the solid surface are investigated. The rate of energy transfer from the plasma to the wall is calculated, and the conditions under which wall surface melting occurs are estimated. The physical conditions previously studied experimentally by Feinberg, are calculated, and the predicted rate of energy transfer from the plasma to the wall is found to be in good agreement.

  17. FOREWORD: 23rd National Symposium on Plasma Science & Technology (PLASMA-2008)

    Science.gov (United States)

    Das, A. K.

    2010-01-01

    The Twentieth Century has been a defining period for Plasma Science and Technology. The state of ionized matter, so named by Irving Langmuir in the early part of twentieth century, has now evolved in to a multidisciplinary area with scientists and engineers from various specializations working together to exploit the unique properties of the plasma medium. There have been great improvements in the basic understanding of plasmas as a many body system bound by complex collective Coulomb interactions of charges, atoms, molecules, free radicals and photons. Simultaneously, many advanced plasma based technologies are increasingly being implemented for industrial and societal use. The emergence of the multination collaborative project International Thermonuclear Experimental Reactor (ITER) project has provided the much needed boost to the researchers working on thermonuclear fusion plasmas. In addition, the other plasma applications like MHD converters, hydrogen generation, advanced materials (synthesis, processing and surface modification), environment (waste beneficiation, air and water pollution management), nanotechnology (synthesis, deposition and etching), light production, heating etc are actively being pursued in governmental and industrial sectors. For India, plasma science and technology has traditionally remained an important area of research. It was nearly a century earlier that the Saha ionization relation pioneered the way to interpret experimental data from a vast range of near equilibrium plasmas. Today, Indian research contributions and technology demonstration capabilities encompass thermonuclear fusion devices, nonlinear plasma phenomena, plasma accelerators, beam plasma interactions, dusty and nonneutral plasmas, industrial plasmas and plasma processing of materials, nano synthesis and structuring, astrophysical and space plasmas etc. India's participation in the ITER programme is now reflected in increased interest in the research and development

  18. Cattaneo-Christov on heat and mass transfer of unsteady Eyring Powell dusty nanofluid over sheet with heat and mass flux conditions

    Directory of Open Access Journals (Sweden)

    Mamatha S. Upadhay

    2017-01-01

    Full Text Available Heat and mass flux conditions on magnetohydrodynamic unsteady Eyring-Powell dusty nanofluid over a sheet is addressed. The combined effect of Brownian motion and thermophoresis in nanofluid modeling are retained. The Cattaneo-Christov heat flux model is imposed. A set of similarity variables are utilized to form ordinary differential system from the prevailing partial differential equations. The problem of ordinary differential system (ODS is analyzed numerically through Runge-Kutta based shooting method. Graphical results of pertinent parameters on the velocity, temperature and nanoparticle concentration are studied. Skin friction coefficient, local Nusselt and Sherwood number are also addressed with help of graphs and also validated the present solutions with already existing solutions in the form of table. It is found that the thermal relaxation parameter improves the heat transfer rate and minimizes the mass transfer rate. The heat transfer rate is higher in prescribed heat flux (PHF case when compared with prescribed wall temperature (PWT case.

  19. Heat Transfer in MHD Dusty Boundary Layer Flow over an Inclined Stretching Sheet with Non-Uniform Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    G. K. Ramesh

    2012-01-01

    Full Text Available This paper presents the study of momentum and heat transfer characteristics in a hydromagnetic flow of dusty fluid over an inclined stretching sheet with non-uniform heat source/sink, where the flow is generated due to a linear stretching of the sheet. Using a similarity transformation, the governing equations of the problem are reduced to a coupled third-order nonlinear ordinary differential equations and are solved numerically by Runge-Kutta-Fehlberg fourth-fifth-order method using symbolic software Maple. Our numerical solutions are shown to agree with the available results in the literature and then employ the numerical results to bring out the effects of the fluid-particle interaction parameter, local Grashof number, angle of inclination, heat source/sink parameter, Chandrasekhar number, and the Prandtl number on the flow and heat transfer characteristics. The results have possible technological applications in liquid-based systems involving stretchable materials.

  20. Comparative thermal cyclic test of different beryllium grades previously subjected to simulated disruption loads

    International Nuclear Information System (INIS)

    Gervash, A.; Giniyatulin, R.; Mazul, I.

    1999-01-01

    Considering beryllium as plasma facing armour this paper presents recent results obtained in Russia. A special process of joining beryllium to a Cu-alloy material structure is described and recent results of thermal cycling tests of such joints are presented. Summarizing the results, the authors show that a Cu-alloy heat sink structure armoured with beryllium can survive high heat fluxes (≥10 MW/m 2 ) during 1000 heating/cooling cycles without serious damage to the armour material and its joint. The principal feasibility of thermal cycling of beryllium grades and their joints directly in the core of a nuclear reactor is demonstrated and the main results of this test are presented. The paper also describes the thermal cycling of different beryllium grades having cracks initiated by previously applied high heat loads simulating plasma disruptions. (orig.)

  1. Fusion Plasma Theory project summaries

    International Nuclear Information System (INIS)

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively-participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at US government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the US Fusion Energy Program

  2. Fusion Plasma Theory project summaries

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively-participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at US government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the US Fusion Energy Program.

  3. Fusion plasma theory project summaries

    Science.gov (United States)

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at U.S. government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the U.S. Fusion Energy Program.

  4. Determining root correspondence between previously and newly detected objects

    Science.gov (United States)

    Paglieroni, David W.; Beer, N Reginald

    2014-06-17

    A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

  5. BOOK REVIEW: Kinetic theory of plasma waves, homogeneous plasmas

    Science.gov (United States)

    Porkolab, Miklos

    1998-11-01

    addition to the literature, for it gives the teacher of the subject a valuable reference where the inquisitive student will be able to read up on and satisfy himself about the practicality and reliability of the Vlasov theory in a hot magnetized and collisionless plasma. The book has excellent treatments of several new topics not included in previous textbooks, for example, the relativistic theory of plasma wave propagation, so important in electron cyclotron heating of magnetically confined fusion plasmas, a discussion of current drive theory and there is a welcome introduction to parametric instabilities in the final chapter. There are some things that make the readability of the book somewhat difficult. In the early parts, certain advanced concepts are introduced without much motivation or explanation, although the author is trying to be helpful by providing a list of relevant references at the end of each chapter. Here the teacher's role will be critical. Again, a certain amount of previous knowledge of the subject would prove to be invaluable to the student. The main content of the book is included in 11 chapters. Use is made of CGS Gaussian units, a favourite of plasma theorists. As the author states, these are still widely used in advanced plasma theory, and the student is well advised to become familiar with this system of units (as well as the SI system for applications). To help the reader in the Introduction, the author defines various expressions often used in plasma physics in practical units (frequencies in hertz, lengths in centimetres, temperatures in kiloelectronvolts and magnetic fields in teslas). Chapter 2 is entitled `Plasma Electrodynamics' and it introduces the Maxwell-Vlasov set of equations, as well as the important fundamentals of wave propagation, such as polarization, dispersion and the dielectric tensor, and energy relations. In Chapter 3, `Elementary Plasma Kinetic Theory', the author derives the Vlasov equation and the Fokker-Planck equation

  6. Noninvasive prenatal molecular karyotyping from maternal plasma.

    Directory of Open Access Journals (Sweden)

    Stephanie C Y Yu

    Full Text Available Fetal DNA is present in the plasma of pregnant women. Massively parallel sequencing of maternal plasma DNA has been used to detect fetal trisomies 21, 18, 13 and selected sex chromosomal aneuploidies noninvasively. Case reports describing the detection of fetal microdeletions from maternal plasma using massively parallel sequencing have been reported. However, these previous reports were either polymorphism-dependent or used statistical analyses which were confined to one or a small number of selected parts of the genome. In this report, we reported a procedure for performing noninvasive prenatal karyotyping at 3 Mb resolution across the whole genome through the massively parallel sequencing of maternal plasma DNA. This method has been used to analyze the plasma obtained from 6 cases. In three cases, fetal microdeletions have been detected successfully from maternal plasma. In two cases, fetal microduplications have been detected successfully from maternal plasma. In the remaining case, the plasma DNA sequencing result was consistent with the pregnant mother being a carrier of a microduplication. Simulation analyses were performed for determining the number of plasma DNA molecules that would need to be sequenced and aligned for enhancing the diagnostic resolution of noninvasive prenatal karyotyping to 2 Mb and 1 Mb. In conclusion, noninvasive prenatal molecular karyotyping from maternal plasma by massively parallel sequencing is feasible and would enhance the diagnostic spectrum of noninvasive prenatal testing.

  7. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  8. Plasma Exchange for Refractory MDA5 Myositis and ILD

    Science.gov (United States)

    2017-04-26

    59 MDW/SGVU SUBJECT: Professional Presentation Approval 18 APR 2017 1. Your paper, entitled Plasma Exchange for Refractorv MDAS myositis and ILD...submitted for review and approval.) Plasma exchange for refractory MDA5 myositis and ILD 6. TITLE OF MATERIAL TO BE PUBLISHED OR PRESENTED: Plasma ...MDWI 41-,08 PREVIOUS EDITIONS ARE OBSOLETE 50. DATE Page 3 of 3 Pages Sidari CCR Abstract Rough Drafts Title: Plasma exchange for refractory MDAS

  9. Plasma physics and fusion plasma electrodynamics

    CERN Document Server

    Bers, Abraham

    2016-01-01

    Plasma is a ubiquitous state of matter at high temperatures. The electrodynamics of plasmas encompasses a large number of applications, from understanding plasmas in space and the stars, to their use in processing semiconductors, and their role in controlled energy generation by nuclear fusion. This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are offered, making both simple and complex aspects of the subject available in nearly every chapter. The approach of dividing the basic aspects of plasma physics as "linear, hydrodynamic descriptions" to be covered first because they are "easier", and postponing the "nonlinear and kinetic descriptions" for later because they are "difficult" is abandoned in this book. For teaching purpose...

  10. Quiescent plasma machine for plasma investigation

    International Nuclear Information System (INIS)

    Ferreira, J.L.

    1993-01-01

    A large volume quiescent plasma device is being developed at INPE to study Langmuir waves and turbulence generated by electron beams (E b ≤ 500 e V) interacting with plasma. This new quiescent plasma machine was designed to allow the performance of several experiments specially those related with laboratory space plasma simulation experiments. Current-driven instabilities and related phenomena such as double-layers along magnetic field lines are some of the many experiments planned for this machine. (author)

  11. Plasma-wall interaction; Interaction plasma paroi

    Energy Technology Data Exchange (ETDEWEB)

    Reichle, R

    2004-07-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER.

  12. Conclusive evidence of abrupt coagulation inside the void during cyclic nanoparticle formation in reactive plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wetering, F. M. J. H. van de; Nijdam, S.; Beckers, J. [Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2016-07-25

    In this letter, we present scanning electron microscopy (SEM) results that confirm in a direct way our earlier explanation of an abrupt coagulation event as the cause for the void hiccup. In a recent paper, we reported on the fast and interrupted expansion of voids in a reactive dusty argon–acetylene plasma. The voids appeared one after the other, each showing a peculiar, though reproducible, behavior of successive periods of fast expansion, abrupt contraction, and continued expansion. The abrupt contraction was termed “hiccup” and was related to collective coagulation of a new generation of nanoparticles growing in the void using relatively indirect methods: electron density measurements and optical emission spectroscopy. In this letter, we present conclusive evidence using SEM of particles collected at different moments in time spanning several growth cycles, which enables us to follow the nanoparticle formation process in great detail.

  13. Stability analysis of Hasegawa space-charge waves in a plasma waveguide with collisional ion beam

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-12-01

    The dispersion relation for the Hasegawa space-charge wave propagating in a cylindrical waveguide dusty plasma containing collision-dominated ion stream is derived by using the fluid equations and the Poisson equation which lead to a Bessel equation. The solution of Bessel equation is null at the boundary and then the roots of the Bessel function would characterize the property of space-charge wave propagation. We have found that the Hasegawa space-charge wave can be excited for a large axial wave number. The growth rate of excitation increases as the order of the roots of the Bessel function increases. The growth rate decreases with an increase of the radius of cylindrical waveguide as well as with an increase of the collision frequency. We found that the disturbance of wave can be damped only for small wave numbers.

  14. Conclusive evidence of abrupt coagulation inside the void during cyclic nanoparticle formation in reactive plasma

    International Nuclear Information System (INIS)

    Wetering, F. M. J. H. van de; Nijdam, S.; Beckers, J.

    2016-01-01

    In this letter, we present scanning electron microscopy (SEM) results that confirm in a direct way our earlier explanation of an abrupt coagulation event as the cause for the void hiccup. In a recent paper, we reported on the fast and interrupted expansion of voids in a reactive dusty argon–acetylene plasma. The voids appeared one after the other, each showing a peculiar, though reproducible, behavior of successive periods of fast expansion, abrupt contraction, and continued expansion. The abrupt contraction was termed “hiccup” and was related to collective coagulation of a new generation of nanoparticles growing in the void using relatively indirect methods: electron density measurements and optical emission spectroscopy. In this letter, we present conclusive evidence using SEM of particles collected at different moments in time spanning several growth cycles, which enables us to follow the nanoparticle formation process in great detail.

  15. Wakefield generation in magnetized plasmas

    International Nuclear Information System (INIS)

    Holkundkar, Amol; Brodin, Gert; Marklund, Mattias

    2011-01-01

    We consider wakefield generation in plasmas by electromagnetic pulses propagating perpendicular to a strong magnetic field, in the regime where the electron cyclotron frequency is equal to or larger than the plasma frequency. Particle-in-cell simulations reveal that for moderate magnetic field strengths previous results are reproduced, and the wakefield wave number spectrum has a clear peak at the inverse skin depth. However, when the cyclotron frequency is significantly larger than the plasma frequency, the wakefield spectrum becomes broadband, and simultaneously the loss rate of the driving pulse is much enhanced. A set of equations for the scalar and vector potentials reproducing these results are derived, using only the assumption of a weakly nonlinear interaction.

  16. Fusion plasma physics

    CERN Document Server

    Stacey, Weston M

    2012-01-01

    This revised and enlarged second edition of the popular textbook and reference contains comprehensive treatments of both the established foundations of magnetic fusion plasma physics and of the newly developing areas of active research. It concludes with a look ahead to fusion power reactors of the future. The well-established topics of fusion plasma physics -- basic plasma phenomena, Coulomb scattering, drifts of charged particles in magnetic and electric fields, plasma confinement by magnetic fields, kinetic and fluid collective plasma theories, plasma equilibria and flux surface geometry, plasma waves and instabilities, classical and neoclassical transport, plasma-materials interactions, radiation, etc. -- are fully developed from first principles through to the computational models employed in modern plasma physics. The new and emerging topics of fusion plasma physics research -- fluctuation-driven plasma transport and gyrokinetic/gyrofluid computational methodology, the physics of the divertor, neutral ...

  17. Study of single and binary ion plasma expansion into laboratory-generated plasma wakes

    International Nuclear Information System (INIS)

    Wright, K.H. Jr.

    1988-02-01

    Plasma expansion into the wake of a large rectangular plate immersed in a collisionless, supersonic plasma was investigated in laboratory experiments. The experimental conditions address both single ion and binary ion plasma flows for the case of a body whose size is large in comparison with the Debye length, when the potential difference between the body and the plasma is relatively small. A new plasma source was developed to generate equi-velocity, binary ion plasma flows, which allows access to new parameter space that have previously been unavailable for laboratory studies. Specifically, the new parameters are the ionic mass ratio and the ionic component density ratio. In a series of experiments, a krypton-neon plasma is employed where the ambient density ratio of neon to krypton is varied more than an order of magnitude. The expansion in both the single ion and binary ion plasma cases is limited to early times, i.e., a few ion plasma periods, by the combination of plasma density, plasma drift speed, and vacuum chamber size, which prevented detailed comparison with self-similar theory

  18. 2 CFR 1.215 - Relationship to previous issuances.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuances. 1.215 Section 1.215 Grants and Agreements ABOUT TITLE 2 OF THE CODE OF FEDERAL REGULATIONS AND SUBTITLE A Introduction toSubtitle A § 1.215 Relationship to previous issuances. Although some of the guidance was...

  19. 2 CFR 230.45 - Relationship to previous issuance.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuance. 230.45 Section 230.45 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR NON-PROFIT ORGANIZATIONS (OMB CIRCULAR A-122) § 230.45 Relationship to previous issuance. (a...

  20. Research Note Effects of previous cultivation on regeneration of ...

    African Journals Online (AJOL)

    Research Note Effects of previous cultivation on regeneration of Julbernadia globiflora and Brachystegia spiciformis in grazing areas of Mupfurudzi ... Plant attributes for Julbernadia globiflora and Brachystegia spiciformis were measured in previously cultivated and uncultivated sites making up rangelands of the scheme.

  1. 49 CFR 173.23 - Previously authorized packaging.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Previously authorized packaging. 173.23 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation § 173.23 Previously authorized packaging. (a) When the regulations specify a packaging with a specification marking...

  2. 75 FR 76056 - FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT:

    Science.gov (United States)

    2010-12-07

    ... SECURITIES AND EXCHANGE COMMISSION Sunshine Act Meeting FEDERAL REGISTER CITATION OF PREVIOUS ANNOUNCEMENT: STATUS: Closed meeting. PLACE: 100 F Street, NE., Washington, DC. DATE AND TIME OF PREVIOUSLY ANNOUNCED MEETING: Thursday, December 9, 2010 at 2 p.m. CHANGE IN THE MEETING: Time change. The closed...

  3. Triple outlet right ventricle: a previously unknown cardiac malformation.

    Science.gov (United States)

    Tingo, Jennifer E; Carroll, Sheila J; Crystal, Matthew A

    2015-03-01

    We present the case of an infant with three distinct outflow tracts from the right ventricle. Three outlets from the heart have been previously named the "Tritruncal Heart". We review the two previously reported cases of tritruncal hearts and describe the anatomy, diagnosis, surgical management, and outcome of our case. Embryologic implications are also discussed.

  4. Implant breast reconstruction after salvage mastectomy in previously irradiated patients.

    Science.gov (United States)

    Persichetti, Paolo; Cagli, Barbara; Simone, Pierfranco; Cogliandro, Annalisa; Fortunato, Lucio; Altomare, Vittorio; Trodella, Lucio

    2009-04-01

    The most common surgical approach in case of local tumor recurrence after quadrantectomy and radiotherapy is salvage mastectomy. Breast reconstruction is the subsequent phase of the treatment and the plastic surgeon has to operate on previously irradiated and manipulated tissues. The medical literature highlights that breast reconstruction with tissue expanders is not a pursuable option, considering previous radiotherapy a contraindication. The purpose of this retrospective study is to evaluate the influence of previous radiotherapy on 2-stage breast reconstruction (tissue expander/implant). Only patients with analogous timing of radiation therapy and the same demolitive and reconstructive procedures were recruited. The results of this study prove that, after salvage mastectomy in previously irradiated patients, implant reconstruction is still possible. Further comparative studies are, of course, advisable to draw any conclusion on the possibility to perform implant reconstruction in previously irradiated patients.

  5. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  6. High speed cine film studies of plasma behaviour and plasma surface interactions in tokamaks

    International Nuclear Information System (INIS)

    Goodall, D.H.J.

    1982-01-01

    High speed cine photography is a useful diagnostic aid for studying plasma behaviour and plasma surface interactions. Several workers have filmed discharges in tokamaks including ASDEX, DITE, DIVA, ISX, JFT2, TFR and PLT. These films are discussed and examples given of the observed phenomena which include plasma limiter interactions, diverted discharges, disruptions, magnetic islands and moving glowing objects often known as 'UFOs'. Examples of plasma structures in ASDEX and DITE not previously published are also given. The paper also reports experiments in DITE to determine the origin of UFOs. (orig.)

  7. High speed cine film studies of plasma behaviour and plasma surface interactions in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Goodall, D.H.J. (Euratom/UKAEA Fusion Association, Abingdon (UK). Culham Lab.)

    High speed cine photography is a useful diagnostic aid for studying plasma behaviour and plasma surface interactions. Several workers have filmed discharges in tokamaks including ASDEX, DITE, DIVA, ISX, JFT2, TFR and PLT. These films are discussed and examples given of the observed phenomena which include plasma limiter interactions, diverted discharges, disruptions, magnetic islands and moving glowing objects often known as 'UFOs'. Examples of plasma structures in ASDEX and DITE not previously published are also given. The paper also reports experiments in DITE to determine the origin of UFOs.

  8. Localized plasma balls

    Energy Technology Data Exchange (ETDEWEB)

    Figueras, Pau; Tunyasuvunakool, Saran [DAMTP, Centre for Mathematical Sciences,Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2014-06-04

    In this paper we numerically construct localized black hole solutions in the IR end of the confining geometry of the AdS soliton, Witten’s early holographic model for confinement. These black holes should be thought of as finite size analogues of the domain wall solutions that have appeared previously in the literature. From the dual CFT point of view, these black holes correspond to finite size balls of deconfined plasma surrounded by the confining vacuum. The plasma ball solutions are parametrized by the temperature. For temperatures well above the deconfinement transition, the dual black holes are small and round and they are well-described by the asymptotically flat Schwarzschild solution. On the other hand, as the temperature approaches the deconfinement temperature, these these black holes spread out in the directions parallel to IR end of the space-time, whilst their extent in the holographic radial direction remains finite. In these new black hole backgrounds, we compute various probes of confinement/deconfinement such as temporal Wilson loops and entanglement entropy.

  9. Localized plasma balls

    International Nuclear Information System (INIS)

    Figueras, Pau; Tunyasuvunakool, Saran

    2014-01-01

    In this paper we numerically construct localized black hole solutions in the IR end of the confining geometry of the AdS soliton, Witten’s early holographic model for confinement. These black holes should be thought of as finite size analogues of the domain wall solutions that have appeared previously in the literature. From the dual CFT point of view, these black holes correspond to finite size balls of deconfined plasma surrounded by the confining vacuum. The plasma ball solutions are parametrized by the temperature. For temperatures well above the deconfinement transition, the dual black holes are small and round and they are well-described by the asymptotically flat Schwarzschild solution. On the other hand, as the temperature approaches the deconfinement temperature, these these black holes spread out in the directions parallel to IR end of the space-time, whilst their extent in the holographic radial direction remains finite. In these new black hole backgrounds, we compute various probes of confinement/deconfinement such as temporal Wilson loops and entanglement entropy

  10. Dense plasma. 1

    International Nuclear Information System (INIS)

    Kulik, P.P.

    1977-01-01

    The known data on dense plasma investigation are summarized and systemized. The dense plasma is created by joint effect of high temperatures, resulting in thermal substance ionization, and high densities, resulting in ionization by pressure. The state of investigations of plasma properties has been analysed and a contribution of static and kinetic theories to equilibrium plasma investigation has been shown

  11. Collective plasma corrections to thermonuclear reactions rates in dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Tsytovich, V.N. [General Physics Institute, Moscow (Russian Federation)

    2002-01-01

    General kinetic equations for nuclear reaction in dense plasmas are obtained. They take into account the first order collective plasma effects. Together with previously known corrections proportional to Z{sub i}Z{sub j}, the product of the charges Z{sub i} and Z{sub j} of two interacting nuclei, it is shown that there exist corrections proportional to the squares Z{sub i}{sup 2} and Z{sub j}{sup 2} of the charges. It is shown that the Salpeter's [1] correction due to the plasma screening of the interaction potential is at least r/d smaller (r is the nuclei size and d is Debye screening length) than previously thought and is zero in the approximation when the terms of the order r/d are neglected. But the correlation effects in the first approximation in the parameter 1/N{sub d} (where N{sub d} is the number of particle in the Debye sphere) give corrections which often coincide with the first order Salpeter's corrections (found by expansion in another small parameter, the ratio of thermal energy to Gamov's energy). The correlation corrections are {proportional_to} Z{sub i}Z{sub j}, have a different physical meaning than the corrections [1], can have a different sign and are present for reactions where the Salpeter's corrections are zero. Previously in astrophysical applications it was widely used the interpolation formulas between weak and strong Salpeter's screening corrections. Since the correlation correction take place the previously known Salpeter's corrections and the strong correlation corrections is difficult to describe analytically, the interpolation formulas between the weak and strong correlations cannot be yet found. A new type of corrections are found here which are proportional to the square of the charges. They are due to collective change in electrostatic self-energy of the plasma system during the nuclear reactions. The latter corrections are found by taking into account the changes of plasma particle fluctuations by

  12. Adolescents previously involved in Satanism experiencing mental health problems

    Directory of Open Access Journals (Sweden)

    H Heathcote

    1999-09-01

    Full Text Available No research has previously been done regarding the phenomenon of adolescents who have previously been involved in Satanism and who experience obstacles in their strive for mental health. Adolescents previously involved in Satanism present behavioral problems like aggressive outbursts, depression, “ psychosis” or suicide attempts, that could lead to suicide. In the phenomenonanalysis semi-structured, phenomenological interviews were performed with the respondents and their parents. The respondents were requested to write a naïve sketch about their life. After completion of the data-control, guidelines for nursing staff were set.

  13. Collisionless plasmas in astrophysics

    CERN Document Server

    Belmont, Gerard; Mottez, Fabrice; Pantellini, Filippo; Pelletier, Guy

    2013-01-01

    Collisionless Plasmas in Astrophysics examines the unique properties of media without collisions in plasma physics. Experts in this field, the authors present the first book to concentrate on collisionless conditions in plasmas, whether close or not to thermal equilibrium. Filling a void in scientific literature, Collisionless Plasmas in Astrophysics explains the possibilities of modeling such plasmas, using a fluid or a kinetic framework. It also addresses common misconceptions that even professionals may possess, on phenomena such as "collisionless (Landau) damping". Abundant illustrations

  14. Examples of plasma horizons

    International Nuclear Information System (INIS)

    Hanni, R.S.

    1975-01-01

    The concept of the plasma horizon, defined as the boundary of the region in which an infinitely thin plasma can be supported against Coulomb attraction by a magnetic field, shows that the argument of selective accretion does not rule out the existence of charged black holes embedded in a conducting plasma. A detailed account of the covariant definition of plasma horizon is given and some examples of plasma horizons are presented. 7 references

  15. Collisionality dependent transport in TCV SOL plasmas

    International Nuclear Information System (INIS)

    Garcia, O E; Pitts, R A; Horacek, J; Madsen, J; Naulin, V; Nielsen, A H; Rasmussen, J Juul

    2007-01-01

    Results are presented from probe measurements in the low field side scrape-off layer (SOL) region of TCV during plasma current scan experiments. It is shown that with decreasing plasma current the radial particle density profile becomes broader and the fluctuation levels and turbulence driven radial particle flux increase. In the far SOL the fluctuations exhibit a high degree of statistical similarity and the particle density and flux at the wall radius scale inversely with the plasma current. Together with previous TCV density scan experiments, this indicates that plasma fluctuations and radial transport increase with plasma collisionality. Such a collisionality dependence is consistent with a recent theory for radial blob motion, which suggests that filamentary structures become electrically disconnected from the target sheaths at large collisionality and thus experience less sheath dissipation. This increases the radial convective transport and is possibly linked to the discharge density limit

  16. Influence of previous participation in physical activity on its ...

    African Journals Online (AJOL)

    ... participation can influence perceptions of PA among the students. Physical activity promotion programmes should consider the role of these factors which should be emphasised from childhood. Keywords: physical activity, students, perceived benefits, perceived barriers, previous participation, sedentary lifestyle, Rwanda

  17. Choice of contraception after previous operative delivery at a family ...

    African Journals Online (AJOL)

    Choice of contraception after previous operative delivery at a family planning clinic in Northern Nigeria. Amina Mohammed‑Durosinlorun, Joel Adze, Stephen Bature, Caleb Mohammed, Matthew Taingson, Amina Abubakar, Austin Ojabo, Lydia Airede ...

  18. Payload specialist Reinhard Furrer show evidence of previous blood sampling

    Science.gov (United States)

    1985-01-01

    Payload specialist Reinhard Furrer shows evidence of previous blood sampling while Wubbo J. Ockels, Dutch payload specialist (only partially visible), extends his right arm after a sample has been taken. Both men show bruises on their arms.

  19. Delivery outcomes at term after one previous cesarean section.

    Science.gov (United States)

    Yamani-Zamzami, Tarik Y

    2007-12-01

    To determine the maternal and perinatal outcomes at term in women with one previous cesarean delivery and with no history of vaginal birth. This is a case-control study conducted at King Abdul-Aziz University Hospital, Jeddah, Kingdom of Saudi Arabia, between January 1, 1999 and December 31, 2002. One hundred sixty-two women with one previous cesarean delivery and with no previous vaginal birth were compared with 324 control women. The cesarean section rate was higher in the study group 40 (24.7%) versus 23 (7.1%) in the control group and was statistically significant (phistory of vaginal delivery are considered less favorable, the vaginal birth after cesarean section success rate may be even lower if the indication for previous primary cesarean delivery was failure to progress, and may be associated with increased risk of uterine rupture. Further study is required to confirm our findings.

  20. [Influence of previous abdominopelvic surgery on gynecological laparoscopic operation].

    Science.gov (United States)

    Jin, Haoran; Shi, Wei; Zhou, Yingfang; Wu, Beisheng; Peng, Chao

    2014-09-01

    To investigate the influence of previous abdominopelvic surgery on gynecological laparoscopic operation. A retrospective analysis of 3 283 cases of gynecological diseases by laparoscopic operation patients in Peking University First Hospital from 2007 January to 2012 December, among them, 719 (21.90%) patients with previous abdominopelvic surgery history (study Group), 2 564 (78.10%)patients have no history of abdominopelvic surgery (control group). Study group 719 patients, previous operation times: one time in 525 cases, 194 cases were multiple; previous operation: 185 cases of gynecological surgery, 305 cases of obstetric surgery, 108 cases of general surgery, and 121 complex surgery (include at least two kinds of surgery); previous operative approach: 650 cases laparotomy and 69 cases laparoscopy. Compared two groups of patients with abdominopelvic adhesion and the gynecologic laparoscopic operation situation, analyzed the influence of previous abdominopelvic surgery on abdominopelvic adhesion on and gynecological laparoscopic operation. The incidence of abdominopelvic adhesion in the patients with previous abdominopelvic surgery was 51.2% (368/719), which was significantly higher than that of 8.2% (211/2 564)in patients without previous abdominopelvic surgery (P surgery (23.1%, 166/719) was significantly higher than that in the control group (3.3% , 85/2 564;P laparotomy was 0.6% (4/719) significantly more than the control groups (0.1%, 2/2 564; P = 0.023). Compared with other groups, patients with gynecological or complex surgery or multiple operation history presented more severe abdominopelvic adhesion both in the score and degree (P laparotomy showed no statistical difference between the two groups (P > 0.05). The laparoscopic operation could be carried out successfully and safely in patients with a history of various abdominopelvic operations, but the conversion rate increases, for patients with a history of multiple operation because of pelvic adhesion

  1. Plasma Dispersion Functions for Complex Frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, S. S.; Castejon, F.

    2005-07-01

    Plasma dispersion functions for complex wave propagation frequency in the weak relativistic regime for arbitrary longitudinal refractive index are estimated and presented in this work. These functions, that are know as Shkarofsky functions in the case of real frequency, are estimated using a new method that avoids the singularities that appear in previous calculations shown in the preceding literature. These results can be used to obtain the properties of plasma instabilities in the weakly relativistic regime. (Author) 14 refs.

  2. Plasma Dispersion Functions for Complex Frequencies

    International Nuclear Information System (INIS)

    Pavlov, S. S.; Castejon, F.

    2005-01-01

    Plasma dispersion functions for complex wave propagation frequency in the weak relativistic regime for arbitrary longitudinal refractive index are estimated and presented in this work. These functions, that are know as Shkarofsky functions in the case of real frequency, are estimated using a new method that avoids the singularities that appear in previous calculations shown in the preceding literature. These results can be used to obtain the properties of plasma instabilities in the weakly relativistic regime. (Author) 14 refs

  3. Development of high energy pulsed plasma simulator for plasma-lithium trench experiment

    Science.gov (United States)

    Jung, Soonwook

    To simulate detrimental events in a tokamak and provide a test-stand for a liquid lithium infused trench (LiMIT) device, a pulsed plasma source utilizing a theta pinch in conjunction with a coaxial plasma accelerator has been developed. An overall objective of the project is to develop a compact device that can produce 100 MW/m2 to 1 GW/m2 of plasma heat flux (a typical heat flux level in a major fusion device) in ~ 100 mus (≤ 0.1 MJ/m2) for a liquid lithium plasma facing component research. The existing theta pinch device, DEVeX, was built and operated for study on lithium vapor shielding effect. However, a typical plasma energy of 3 - 4 kJ/m2 is too low to study an interaction of plasma and plasma facing components in fusion devices. No or little preionized plasma, ringing of magnetic field, collisions of high energy particles with background gas have been reported as the main issues. Therefore, DEVeX is reconfigured to mitigate these issues. The new device is mainly composed of a plasma gun for a preionization source, a theta pinch for heating, and guiding magnets for a better plasma transportation. Each component will be driven by capacitor banks and controlled by high voltage / current switches. Several diagnostics including triple Langmuir probe, calorimeter, optical emission measurement, Rogowski coil, flux loop, and fast ionization gauge are used to characterize the new device. A coaxial plasma gun is manufactured and installed in the previous theta pinch chamber. The plasma gun is equipped with 500 uF capacitor and a gas puff valve. The increase of the plasma velocity with the plasma gun capacitor voltage is consistent with the theoretical predictions and the velocity is located between the snowplow model and the weak - coupling limit. Plasma energies measured with the calorimeter ranges from 0.02 - 0.065 MJ/m2 and increases with the voltage at the capacitor bank. A cross-check between the plasma energy measured with the calorimeter and the triple probe

  4. FORMATION AND ALIGNMENT OF ELONGATED, FRACTAL-LIKE WATER-ICE GRAINS IN EXTREMELY COLD, WEAKLY IONIZED PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Kil-Byoung; Bellan, Paul M., E-mail: kbchai@caltech.edu, E-mail: pbellan@caltech.edu [Applied Physics and Materials Science, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States)

    2015-04-01

    Elongated, fractal-like water-ice grains are observed to form spontaneously when water vapor is injected into a weakly ionized laboratory plasma formed in a background gas cooled to an astrophysically relevant temperature. The water-ice grains form in 1–2 minutes, levitate with regular spacing, and are aligned parallel to the sheath electric field. Water-ice grains formed in plasma where the neutrals and ions have low mass, such as hydrogen and helium, are larger, more elongated, and more fractal-like than water-ice grains formed in plasmas where the neutrals and ions have high mass such as argon and krypton. Typical aspect ratios (length to width ratio) are as great as 5 while typical fractal dimensions are ∼1.7. Water-ice grain lengths in plasmas with low neutral and ion masses can be several hundred microns long. Infrared absorption spectroscopy reveals that the water-ice grains are crystalline and so are similar in constitution to the water-ice grains in protoplanetary disks, Saturn’s rings, and mesospheric clouds. The properties and behavior of these laboratory water-ice grains may provide insights into morphology and alignment behavior of water-ice grains in astrophysical dusty plasmas.

  5. Electric fields in plasmas under pulsed currents

    International Nuclear Information System (INIS)

    Tsigutkin, K.; Doron, R.; Stambulchik, E.; Bernshtam, V.; Maron, Y.; Fruchtman, A.; Commisso, R. J.

    2007-01-01

    Electric fields in a plasma that conducts a high-current pulse are measured as a function of time and space. The experiment is performed using a coaxial configuration, in which a current rising to 160 kA in 100 ns is conducted through a plasma that prefills the region between two coaxial electrodes. The electric field is determined using laser spectroscopy and line-shape analysis. Plasma doping allows for three-dimensional spatially resolved measurements. The measured peak magnitude and propagation velocity of the electric field is found to match those of the Hall electric field, inferred from the magnetic-field front propagation measured previously

  6. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2011-01-01

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  7. Secondary recurrent miscarriage is associated with previous male birth.

    LENUS (Irish Health Repository)

    Ooi, Poh Veh

    2012-01-31

    Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.

  8. Collaborative project: research on strongly coupled plasmas. Final technical report for period July 15, 1998--July 14, 2002

    Energy Technology Data Exchange (ETDEWEB)

    Golden, Kenneth I.

    2002-09-16

    The main research accomplishments/findings of the project were the following: (1) Publication of an in-depth review article in Physics of Plasmas on the quasilocalized charge approximation (QLCA) in strongly coupled plasma physics and its application to a variety of Coulomb systems: the model one-component plasma in three and two dimensions, binary ionic mixtures, charged particle bilayers, and laboratory dusty plasmas. (2) In the strongly coupled Coulomb liquid phase, the physical basis of the QLCA, namely, the caging of particles trapped in slowly fluctuating local potential minima, is supported by molecular dynamics simulation of the classical three-dimensional one-component plasma. (3) The QLCA theory, when applied to the analysis of the collective modes in strongly coupled charged particle bilayers, predicts the existence of a remarkable long-wavelength energy gap in the out-of-phase excitation spectrum. More recent theoretical calculations based on the three principal frequency-moment sum rules reveal that the gap persists for arbitrary coupling strengths and over the entire classical to quantum domain all the way down to zero temperature. The existence of the energy gap has now been confirmed in a molecular dynamics simulation of the charged particle bilayer. (4) New compressibility and third-frequency-moment sum rules for multilayer plasmas were formulated and applied to the analysis of the dynamical structure function of charged particle bilayers and superlattices. (5) An equivalent of the Debye-Huckel weak coupling equilibrium theory for classical charged particle bilayer and superlattice plasmas was formulated. (6) The quadratic fluctuation-dissipation theorem (QFDT) for layered classical plasmas was formulated. (7) The QFDT was applied to a powerful kinetic theory-based description of the density-density response function and long-wavelength plasma mode behavior in strongly coupled two-dimensional Coulomb fluids in the weakly degenerate quantum domain.

  9. Down syndrome screening marker levels in women with a previous aneuploidy pregnancy.

    Science.gov (United States)

    Cuckle, Howard S; Spencer, K; Nicolaides, K H

    2005-01-01

    In Down syndrome screening programmes, women with a previous affected pregnancy are assumed to have the same marker distribution as those without a family history. This assumption needs to be tested. Information on previous aneuploidy pregnancies was routinely sought on the test request forms in three centres, Leeds, Romford and the Fetal Medicine Centre, London. For each woman with a previous aneuploidy (case), five unaffected pregnancies to women without a history were selected as controls. The markers tested included maternal serum free beta-human chorionic gonadotrophin (hCG), pregnancy-associated plasma protein A (PAPP-A), alpha-fetoprotein, unconjugated estriol and ultrasound nuchal translucency thickness. There were 375 cases: 303 with previous Down syndrome, 63 with Edwards syndrome and 9 with Patau's syndrome. There was a statistically significant difference between cases and controls, in the distribution of free beta-hCG and PAPP-A levels, adjusted for gestation. On average, free beta-hCG was increased by 10% in a subsequent pregnancy after aneuploidy (p pregnancies are available for study, it would be prudent to assume that the same increase as in unaffected pregnancies applies. Copyright (c) 2005 John Wiley & Sons, Ltd.

  10. Statistical Plasma Physics

    CERN Document Server

    Ichimaru, Setsuo

    2004-01-01

    Plasma physics is an integral part of statistical physics, complete with its own basic theories. Designed as a two-volume set, Statistical Plasma Physics is intended for advanced undergraduate and beginning graduate courses on plasma and statistical physics, and as such, its presentation is self-contained and should be read without difficulty by those with backgrounds in classical mechanics, electricity and magnetism, quantum mechanics, and statistics. Major topics include: plasma phenomena in nature, kinetic equations, plasmas and dielectric media, electromagnetic properties of Vlasov plasmas in thermodynamic equilibria, transient processes, and instabilities. Statistical Plasma Physics, Volume II, treats subjects in the field of condensed plasma physics, with applications to condensed matter physics, atomic physics, nuclear physics, and astrophysics. The aim of this book is to elucidate a number of basic topics in physics of dense plasmas that interface with condensed matter physics, atomic physics, nuclear...

  11. Current drive by asymmetrical heating in a toroidal plasma

    International Nuclear Information System (INIS)

    Gahl, J.M.

    1986-01-01

    This report describes the first experimental observation of current generation by asymmetrical heating of ions. A unidirectional fast Alfven wave launched by a slow-wave antenna inside the Texas Tech Tokamak, asymmetrically heated the ions. Measurements of the asymmetry of the toroidal plasma current with probes at the top and bottom of the toroidal plasma column confirmed the current generation indirectly. Current generation, obtained in a one-species, hydrogen plasma, is a phenomenon which had not been predicted previously. Calculations of the dispersion relation for the fast Alfven wave near the fundamental cyclotron resonance in a one-species, hydrogen plasma, using warm plasma theory, support the experimental results

  12. Theory of electromagnetic fluctuations for magnetized multi-species plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Roberto E., E-mail: roberto.navarro@ug.uchile.cl; Muñoz, Víctor [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Araneda, Jaime [Departamento de Física, Universidad de Concepción, Concepción 4070386 (Chile); Moya, Pablo S. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Department of Physics, Catholic University of America, Washington, D. C. 20064 (United States); Viñas, Adolfo F. [NASA Goddard Space Flight Center, Heliophysics Science Division, Geospace Physics Laboratory, Mail Code 673, Greenbelt, Maryland 20771 (United States); Valdivia, Juan A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Centro de Estudios Interdisciplinarios Básicos y Aplicados en Complejidad, CEIBA complejidad, Bogotá (Colombia)

    2014-09-15

    Analysis of electromagnetic fluctuations in plasma provides relevant information about the plasma state and its macroscopic properties. In particular, the solar wind persistently sustains a small but detectable level of magnetic fluctuation power even near thermal equilibrium. These fluctuations may be related to spontaneous electromagnetic fluctuations arising from the discreteness of charged particles. Here, we derive general expressions for the plasma fluctuations in a multi-species plasma following arbitrary distribution functions. This formalism, which generalizes and includes previous works on the subject, is then applied to the generation of electromagnetic fluctuations propagating along a background magnetic field in a plasma of two proton populations described by drifting bi-Maxwellians.

  13. Dust acoustic waves in complex plasmas at elevated pressure

    International Nuclear Information System (INIS)

    Filippov, A.V.; Starostin, A.N.; Tkachenko, I.M.; Fortov, V.E.

    2011-01-01

    The bi-Yukawa effective interaction potential with different screening constants is employed to calculate dust static correlation functions in the hyper-netted chain approximation and to generalize the theory of dust acoustic waves within the non-perturbative moment approach complemented by hydrodynamic considerations. For the bi-Yukawa interaction potential the sound speed becomes significantly wavenumber-dependent, an additional soft diffusion-like mode is predicted, and the static dielectric function is shown to take negative values. The results can be applied to non-equilibrium dusty plasmas at elevated pressure. -- Highlights: ► Bi-Yukawa interaction potential of dust particles with different screening lengths. ► Dust static correlation functions in the hyper-netted chain approximation. ► The moment and hydrodynamic approaches are in a good agreement at weak non-ideality. ► The dust acoustic wave phase and group velocities depend on the wavenumber. ► The moment approach hints the appearance of the diffusion-like soft mode.

  14. PREFACE: First International Workshop on Nonequilibrium Processes in Plasma Physics and Studies of Environment

    Science.gov (United States)

    Petrović, Z. Lj; Malović, G.; Tasić, M.; Nikitović, Ž.

    2007-06-01

    from many different standpoints. A special case of non-equilibrium is that of non-neutral plasmas, i.e. plasmas devoid of ions, as described in the lecture and paper by J Marler (Appleton, USA). Physics of swarms (the low space charge limit of ionized gases) is similar to the previous study in the fact that we may have only one group of charged particles electrons (or ions). But the difference is that the latter has a much higher pressure and therefore number of collisions. In the lecture on one aspect of the application of swarm data (transport coefficients) to determine the electron scattering cross sections R White (Townsville, Australia) addresses a long standing controversy in the vibrational excitation of H2 of an unacceptable discrepancy between swarm results and binary collision experiments and theories, (a problem that has been of particular importance to the host Laboratory). The lecture of N Dyatko (Troitsk, Russian Federation) tackles one of the most interesting recent problems in the transport theory of ionized gases, that of the negative absolute conductivity and attempts to translate it to solid state physics where the stakes are much higher. The swarm studies were always based on excellent experimental data and the leading experimental group today is that of J de Urquijo (Cuernavaca, Mexico) who presents a review of a wide range of transport data that his group obtained in fluorinated gases. The gas breakdown in dc and high frequency fields was addressed by M Radmilović-Rađenović (Belgrade, Serbia) by applying a detailed secondary electron production model in Particle in Cell (PIC) code and comparing the results to a broad range of experimental data. The hybrid (fluid-Monte Carlo) model has been applied in the study by Z Donko and K Kutasi (Budapest, Hungary) of low pressure obstructed glow discharges to decribe the effect of fast neutrals on gas discharges. A study of kinetics of negative ions of hydrogen in glow discharges with positive column and

  15. Plasmas and fluids

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Plasma and fluid physics includes the fields of fusion research and space investigation. This book discusses the most important advances in these areas over the past decade and recommends a stronger commitment to basic research in plasma and fluid physics. The book recommends that plasma and fluid physics be included in physics curriculums because of their increasing importance in energy and defense. The book also lists recent accomplishments in the fields of general plasma physics, fusion plasma confinement and heating, space and astrophysical plasmas, and fluid physics and lists research opportunities in these areas. A funding summary explains how research monies are allocated and suggests ways to improve their effectiveness

  16. Reviews of plasma physics

    CERN Document Server

    2008-01-01

    "Reviews of Plasma Physics Volume 24," edited by V.D. Shafranov, presents two reviews from the cutting-edge of Russian plasma physics research. The first review by V.A. Rozhansky devoted to the mechanisms of transverse conductivity and generation of self-consistent electric fields in strongly ionized magnetized plasma. The second review by O.G. Bakunin considers numerous aspects of turbulent transport in plasma and fluids. This review is focused on scaling arguments for describing anomalous diffusion in the presence of complex structures. These topics are especially important for fusion plasma research, plasma astrophysics, discharge physics, and turbulence

  17. Plasma effects in the formation, evolution and present configuration of the Saturnian ring system

    International Nuclear Information System (INIS)

    Alfven, H.; Mendis, D.A.

    1983-01-01

    The Voyager 1 and 2 observations of the fine structure of the Saturnian ring system demonstrate the importance of electric forces in controlling the dynamics of fine (charged) dust in the rings. A new theory ('gravito-electrodynamics') which combines the electric and the gravitational forces on these grains leads to natural explanations of a number of observed ring phenomena. If plasma processes play a significant role in the dynamics of the ring system at the present time, it is difficult to avoid the conclusion that they also played an important and perhaps crucial role at cosmogonic times during the emplacement and subsequent condensation of the initial dusty plasma. It is suggested that the Saturnian ring system represents a 'time-capsule' containing vital clues about the physical processes operating during the early stages of its formation. It is shown that both its overall structure as well as its fine structure, as determined by Voyagers 1 and 2, indicate the crucial importance of plasma processes in its formation and subsequent evolution

  18. 2 CFR 225.45 - Relationship to previous issuance.

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuance. 225.45 Section 225.45 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR STATE, LOCAL, AND INDIAN TRIBAL GOVERNMENTS (OMB CIRCULAR A-87) § 225.45 Relationship to...

  19. Cryptococcal meningitis in a previously healthy child | Chimowa ...

    African Journals Online (AJOL)

    An 8-year-old previously healthy female presented with a 3 weeks history of headache, neck stiffness, deafness, fever and vomiting and was diagnosed with cryptococcal meningitis. She had documented hearing loss and was referred to tertiary-level care after treatment with fluconazole did not improve her neurological ...

  20. Rapid fish stock depletion in previously unexploited seamounts: the ...

    African Journals Online (AJOL)

    Rapid fish stock depletion in previously unexploited seamounts: the case of Beryx splendens from the Sierra Leone Rise (Gulf of Guinea) ... A spectral analysis and red-noise spectra procedure (REDFIT) algorithm was used to identify the red-noise spectrum from the gaps in the observed time-series of catch per unit effort by ...