WorldWideScience

Sample records for plasma parameters achieved

  1. Plasma diagnostics discharge parameters and chemistry

    CERN Document Server

    Auciello, Orlando

    1989-01-01

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

  2. Plasma Medicine: Current Achievements and Future Prospects

    Science.gov (United States)

    Laroussi, Mounir

    2012-10-01

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

  3. Sensor for monitoring plasma parameters

    CERN Document Server

    Bolshakov, A A; Sharma, S P; Bol'shakov, Alexander A.; Cruden, Brett A.; Sharma, Surendra P.

    2004-01-01

    A spectrally tunable VCSEL (vertical cavity surface-emitting laser) was used as part of sensing hardware for measurements of the radial-integrated gas temperature inside an inductively coupled plasma reactor. The data were obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon/nitrogen plasmas (3, 45, and 90% N2 in Ar) at pressure 0.5-70 Pa and inductive power of 100 and 300 W. The results were compared to rotational temperature derived from the N2 emission at the (0,0) transition of the C - B system. The differences in integrated rotational and Doppler temperatures were attributed to non-uniform spatial distributions of both temperature and thermometric species (Ar* and N2*) that varied depending on conditions. A two-dimensional, two-temperature fluid plasma simulation was employed to explain these differences. This work should facilitate further development of a miniature sensor for non-intrusive acquisition of data (temperature and densities of multipl...

  4. Optimization of audio - ultrasonic plasma system parameters

    Science.gov (United States)

    Haleem, N. A.; Abdelrahman, M. M.; Ragheb, M. S.

    2016-10-01

    The present plasma is a special glow plasma type generated by an audio ultrasonic discharge voltage. A definite discharge frequency using a gas at a narrow band pressure creates and stabilizes this plasma type. The plasma cell is a self-extracted ion beam; it is featured with its high output intensity and its small size. The influence of the plasma column length on the output beam due to the variation of both the audio discharge frequency and the power applied to the plasma electrodes is investigated. In consequence, the aim of the present work is to put in evidence the parameters that influence the self-extracted collected ion beam and to optimize the conditions that enhance the collected ion beam. The experimental parameters studied are the nitrogen gas, the applied frequency from 10 to 100 kHz, the plasma length that varies from 8 to 14 cm, at a gas pressure of ≈ 0.25 Torr and finally the discharge power from 50 to 500 Watt. A sheet of polyethylene of 5 micrometer covers the collector electrode in order to confirm how much ions from the beam can go through the polymer and reach the collector. To diagnose the occurring events of the beam on the collector, the polymer used is analyzed by means of the FTIR and the XRF techniques. Optimization of the plasma cell parameters succeeded to enhance and to identify the parameters that influence the output ion beam and proved that its particles attaining the collector are multi-energetic.

  5. Sensitivity of transient synchrotron radiation to tokamak plasma parameters

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-12-01

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

  6. Variation of plasma parameters in a modified mode of plasma production in a double plasma device

    Indian Academy of Sciences (India)

    A Phukan; M K Mishra; B K Saikia; M Chakraborty

    2010-03-01

    A modified mode of plasma production in a double plasma device is presented and plasma parameters are controlled in this configuration. Here plasma is produced by applying a discharge voltage between the hot filaments in the source (cathode) and the target magnetic cage (anode) of the device. In this configuration, the hot electron emitting filaments are present only in the source and the magnetic cage of this is kept at a negative bias such that due to the repulsion of the cage bias, the primary electrons can go to the grounded target and produce plasma there. The plasma parameters can be controlled by varying the voltages applied to the source magnetic cage and the separation grid of the device.

  7. Parameters of atmospheric plasmas produced by electrosurgical devices

    Science.gov (United States)

    Keidar, Michael; Shashurin, Alexey; Canady, Jerome

    2013-10-01

    Electrosurgical systems are extensively utilized in general surgery, surgical oncology, plastic and reconstructive surgery etc. In this work we study plasma parameters created by electrosurgical system SS-200E/Argon 2 of US Medical Innovations. The maximal length of the discharge plasma column at which the discharge can be sustained was determined as function of discharge power and argon flow rate. Electrical parameters including discharge current and voltage were measured. Recently proposed Rayleigh microwave scattering method for temporally resolved density measurements of small-size atmospheric plasmas was utilized. Simultaneously, evolution of plasma column was observed using intensified charge-coupled device (ICCD) camera.

  8. Numerical Simulation of Basic Parameters in Plasma Spray

    Institute of Scientific and Technical Information of China (English)

    范群波; 王鲁; 王富耻

    2004-01-01

    On the basis of energy balance in the plasma gas, a new, simplified but effective mathematical model is developed to predict the temperature, velocity and ionization degrees of different species at the torch exit, which can be directly calculated just by inputting the general spraying parameters, such as current, voltage, flow rates of gases, etc. Based on this method, the effects of plasma current and the flow rate of Ar on the basic parameters at the torch exit are discussed. The results show that the temperature, velocity and ionization degrees of gas species will increase with increasing the plasma current; while increasing Ar flow rate can increase the velocity at the exit but decrease the temperature and ionization degrees of plasma species. The method would be helpful to predict the temperature and velocity fields in a plasma jet in future, and direct the practical plasma spray operations.

  9. Plasma parameters controlled by remote electron shower in a double plasma device

    Science.gov (United States)

    Mishra, M. K.; Phukan, A.

    2012-07-01

    The principal feature of this experiment is the electron showers consisting of three tungsten wires embedded by the plasma, which are heated up consequently emitting electrons inside the diffused plasma to control the plasma parameters in the discharge section of a double plasma device. These cold electrons emitted by the heated filament are free from maintenance of discharge which is sustained in the source section. The target plasma, where electrons are injected is produced as a result of diffusion from the source section. It is found that, plasma density and plasma potential can be effectively controlled in this way.

  10. Study of parameters of a facility generating compressive plasma flows

    Science.gov (United States)

    Leyvi, A. Ya

    2017-05-01

    The prosperity of plasma technologies stimulates making of a facility generating compressive plasma flows at the South Ural State University. The facility is a compact-geometry magnetoplasma compressor with the following parameters: stored energy up to 15 kJ, voltage of a bank from 3 to 5 kV; nitrogen, air, and other gases can serve as its operating gas. The investigation of parameters of the facility showed the following parameters of compressive plasma flows: impulse duration of up to 120 μs, discharge current of 50-120 kA, speed of plasma flow of 15-30 km/s. By contrast to the available facilities, the parameters of the developed facility can be adjusted in a wide range of voltage from 2 kV to 10 kV, its design permits generating CPF in horizontal and vertical positions.

  11. Achievements and challenges in automated parameter, shape and topology optimization for divertor design

    Science.gov (United States)

    Baelmans, M.; Blommaert, M.; Dekeyser, W.; Van Oevelen, T.

    2017-03-01

    Plasma edge transport codes play a key role in the design of future divertor concepts. Their long simulation times in combination with a large number of control parameters turn the design into a challenging task. In aerodynamics and structural mechanics, adjoint-based optimization techniques have proven successful to tackle similar design challenges. This paper provides an overview of achievements and remaining challenges with these techniques for complex divertor design. It is shown how these developments pave the way for fast sensitivity analysis and improved design from different perspectives.

  12. Collisionless expansion of pulsed radio frequency plasmas. II. Parameter study

    Science.gov (United States)

    Schröder, T.; Grulke, O.; Klinger, T.; Boswell, R. W.; Charles, C.

    2016-01-01

    The plasma parameter dependencies of the dynamics during the expansion of plasma are studied with the use of a versatile particle-in-cell simulation tailored to a plasma expansion experiment [Schröder et al., J. Phys. D: Appl. Phys. 47, 055207 (2014); Schröder et al., Phys. Plasmas 23, 013511 (2016)]. The plasma expansion into a low-density ambient plasma features a propagating ion front that is preceding a density plateau. It has been shown that the front formation is entangled with a wave-breaking mechanism, i.e., an ion collapse [Sack and Schamel, Plasma Phys. Controlled Fusion 27, 717 (1985); Sack and Schamel, Phys. Lett. A 110, 206 (1985)], and the launch of an ion burst [Schröder et al., Phys. Plasmas 23, 013511 (2016)]. The systematic parameter study presented in this paper focuses on the influence on this mechanism its effect on the maximum velocity of the ion front and burst. It is shown that, apart from the well known dependency of the front propagation on the ion sound velocity, it also depends sensitively on the density ratio between main and ambient plasma density. The maximum ion velocity depends further on the initial potential gradient, being mostly influenced by the plasma density ratio in the source and expansion regions. The results of the study are compared with independent numerical studies.

  13. Study on plasma parameters and dust charging in an electrostatically plugged multicusp plasma device

    Science.gov (United States)

    Kakati, B.; Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.

    2011-06-01

    The effect of the electrostatic confinement potential on the charging of dust grains and its relationship with the plasma parameters has been studied in an electrostatically plugged multicusp dusty plasma device. Electrostatic plugging is implemented by biasing the electrically isolated magnetic multicusp channel walls. The experimental results show that voltage applied to the channel walls can be a controlling parameter for dust charging.

  14. Achieving High Accuracy in Calculations of NMR Parameters

    DEFF Research Database (Denmark)

    Faber, Rasmus

    , the (aug-)pcJ-n, n=1,2,3 and the (aug-)ccJpVXZ, X=D,T,Q,5, have been compared for systems where both contact and non-contact contributions to the SSCC are important. It was found that the triple zeta basis sets with diffuse functions, i.e. aug-ccJ-pVTZ or augpcJ- 2, can provide well converged results...... calculations is split amongst errors in the molecular force-field parameters and errors in the shielding surface. Finally, accurate vibrational corrections to the nuclear shielding calculations of noble-gas dimers are presented. While these corrections are small compared to the total shielding, they have...

  15. Effect of gasification parameter on coal gasification in thermal plasma

    Energy Technology Data Exchange (ETDEWEB)

    Shen, S.; Pang, X.; Bao, W.; Lo, Y.; Zhu, S. [Taiyuan University of Technology, Taiyuan (China)

    2004-12-01

    The influence of several parameters such as the power input of plasma jet, vapor and air input etc on gas composition and carbon conversion from coal gasification in an air-steam plasma jet was studied. The main gaseous products are H{sub 2}, CO, CO{sub 2}, CH{sub 2}4 and tar was discovered. Results show that the concentration of H{sub 2}, CO and carbon conversion increases, and the concentration of CO{sub 2} significantly decreases, when the power input of plasma jet is raised. The concentration of H{sub 2} increases when the vapor flux is increased, but excessive steam can decrease carbon conversion. The carbon conversion is enhanced by decreasing feed rate. The air flux should be reduced to improve the quality of coal gas in a certain range. The carbon conversion of Datong coal can exceed 95% at appropriate condition. 18 refs., 4 figs., 2 tabs.

  16. Programmable physical parameter optimization for particle plasma simulations

    Science.gov (United States)

    Ragan-Kelley, Benjamin; Verboncoeur, John; Lin, Ming-Chieh

    2012-10-01

    We have developed a scheme for interactive and programmable optimization of physical parameters for plasma simulations. The simulation code Object-Oriented Plasma Device 1-D (OOPD1) has been adapted to a Python interface, allowing sophisticated user or program interaction with simulations, and detailed numerical analysis via numpy. Because the analysis/diagnostic interface is the same as the input mechanism (the Python programming language), it is straightforward to optimize simulation parameters based on analysis of previous runs and automate the optimization process using a user-determined scheme and criteria. An example use case of the Child-Langmuir space charge limit in bipolar flow is demonstrated, where the beam current is iterated upon by measuring the relationship of the measured current and the injected current.

  17. Investigation of plasma parameters in an active screen cage-pulsed dc plasma used for plasma nitriding

    Science.gov (United States)

    Naeem, M.; Khattak, Z. I.; Zaka-ul-Islam, M.; Shabir, S.; Khan, A. W.; Zakaullah, M.

    2014-11-01

    Active screen cage-pulsed dc plasmas are widely used in the material processing applications such as plasma nitriding, carburizing and nitrocarburizing. Specifically for plasma nitriding applications, a H2-N2 mixture is used. In this article, a study of the electron number density (ne), atomic nitrogen density ([N]), electron temperature ? and the excitation temperature ? is reported in the presence of an active screen cage-pulsed dc plasma. The ne and ? are determined here by a triple Langmuir probe, while [N] and ? are estimated by optical emission spectroscopy (OES). The two temperatures and their ratio ? are compared for different input parameters (such as applied power, gas pressure and H2 percentage). This study is useful in active screen cage plasma nitriding applications where only few plasma diagnostic measurements have been reported.

  18. Study on Performance Parameters of the Plasma Source for a Short-Conduction-Time Plasma Opening Switch

    Institute of Scientific and Technical Information of China (English)

    LUO Weixi; ZENG Zhengzhong; WANG Liangping; LEI Tianshi; HU Yixiang; HUANG Tao; SUN Tieping

    2012-01-01

    Plasma source performance parameters, including plasma ejection density and velocity, greatly affect the operation of a short-conduction-time plasma opening switch (POS). In this paper, the plasma source used in the POS of Qiangguang I generator is chosen as the study object. At first the POS working process is analyzed. The result shows that the opening performance of the POS can be improved by increasing the plasma ejection velocity and decreasing the plasma density. The influence of the cable plasma gun structure and number on the plasma ejection parameters is experimentally investigated with two charge collectors. Finally a semi-empirical model is proposed to describe the experimental phenomenon.

  19. Effect of Substrate Potential on Plasma Parameters of Magnetic Multicusp Plasma Source

    Science.gov (United States)

    Ueda, Yoshio; Goto, Masahiro

    1998-06-01

    The effect of substrate potential on plasmas produced in a magnetic multicusp plasma source has been studied experimentally. Plasma parameters such as electron temperature and plasma potential are estimated from electron energy distribution function numerically calculated from probe current-voltage characteristics. For a substrate potential of -150 V with respect to the source chamber, which is much lower than substrate floating potentials, the plasma parameters are not affected by the application of the potential. However, for the case where the substrate is shorted with the source chamber, the high energy component of electrons significantly decreases in comparison with the floating case leading to the reduction of electron temperature. In this case, plasma potential is positive with respect to the substrate to suppress electron loss but its absolute value is only of the order of electron temperature in eV, which is much lower than the potential between the plasma and the substrate in the floating case. This discharge mode could be advantageous in significantly reducing the ion impact energy to the substrate plate.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-15

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

  1. Plasma Processes : Sheath and plasma parameters in a magnetized plasma system

    Indian Academy of Sciences (India)

    Bornali Singha; A Sharma; J Chutia

    2000-11-01

    The variation of electron temperature and plasma density in a magnetized 2 plasma is studied experimentally in presence of a grid placed at the middle of the system. Plasma leaks through the negatively biased grid from the source region into the diffused region. It is observed that the electron temperature increases with the magnetic field in the diffused region whereas it decreases in the source region of the system for a constant grid biasing voltage. Also, investigation is done to see the change of electron temperature with grid biasing voltage for a constant magnetic field. This is accompanied by the study of the variation of sheath structure across the grid for different magnetic field and grid biasing voltage as well. It reveals that with increasing magnetic field and negative grid biasing voltage, the sheath thickness expands.

  2. A study on plasma parameters in Ar/SF6 inductively coupled plasma

    Science.gov (United States)

    Oh, Seung-Ju; Lee, Hyo-Chang; Chung, Chin-Wook

    2017-01-01

    Sulfur hexafluoride (SF6) gas or Ar/SF6 mixing gas is widely used in plasma processes. However, there are a little experimental studies with various external parameters such as gas pressure and mixing ratio. In this work, a study of the plasma parameters by changing the gas mixing ratio was done in an Ar/SF6 inductively coupled plasma from the measurement of the electron energy distribution function. At a low gas pressure, as the mixing ratio of SF6 gas increased at a fixed inductively coupled plasma (ICP) power, the electron density decreased and the electron temperature increased, while they were not changed drastically. At a high gas pressure, a remarkable increase in the electron temperature was observed with the decrease in the electron density. These variations are due to the electron loss reactions such as the electron attachment. It was also found that at a fixed ICP power, the negative ion creation with the diluted SF6 gas can change the discharge mode transition from an inductive mode to a capacitive mode at the high gas pressure. The electron attachment reactions remove the low energy electrons and change the mean electron energy towards higher energies with diluting SF6 gas at high pressure. The measured results were compared with the simplified global model, and the global model is in relatively good agreement with the measured plasma parameters except for the result in the case of the large portion of SF6 gas at the high pressure and the capacitive mode, which causes strong negative ion formation by the electron attachment reactions.

  3. Evolution of plasma parameters in a He - N2/Ar magnetic pole enhanced inductive plasma source

    Science.gov (United States)

    Younus, Maria; Rehman, N. U.; Shafiq, M.; Zakaullah, M.; Abrar, M.

    2016-02-01

    A magnetic pole enhanced inductively coupled H e - N2/A r plasma is studied at low pressure, to monitor the effects of helium mixing on plasma parameters like electron number density (ne) , electron temperature (Te) , plasma potential (Vp ) , and electron energy probability functions (EEPFs). An RF compensated Langmuir probe is employed to measure these plasma parameters. It is noted that electron number density increases with increasing RF power and helium concentration in the mixture, while it decreases with increase in filling gas pressure. On the other hand, electron temperature shows an increasing trend with helium concentration in the mixture. At low RF powers and low helium concentration in the mixture, EEPFs show a "bi-Maxwellian" distribution with pressure. While at RF powers greater than 50 W and higher helium concentration in the mixture, EEPFs evolve into "Maxwellian" distribution. The variation of skin depth with RF power and helium concentration in the mixture, and its relation with EEPF are also studied. The effect of helium concentrations on the temperatures of two electron groups ( Tb u l k and Tt a i l ) in the "bi-Maxwellian" EEPFs is also observed. The temperature of low energy electron group ( Tb u l k) shows significant increase with helium addition, while the temperature of tail electrons ( Tt a i l) increases smoothly as compared to ( Tb u l k).

  4. Downstream plasma parameters in laminar shocks from ion kinetics

    Science.gov (United States)

    Gedalin, M.

    2016-10-01

    Ion dynamics in oblique shocks is governed by the macroscopic electric and magnetic fields of the shock front. In laminar shocks, these fields are time-independent and depend only on the coordinate along the shock normal. The shock ramp is narrow and the ion motion across the shock is manifestly non-adiabatic. The ion distribution just behind the ramp is significantly non-gyrotropic. Gyrotropy is achieved well behind the ramp mainly due to the gyrophase mixing. The asymptotic values of the ion density and temperature are determined by the eventual collisionless relaxation of the gyrating ion distribution. Given a distribution at the downstream edge of the ramp, the moments of the distribution after gyrophase mixing are derived using proper spatial averaging. The obtained expressions can be used for independent determination of the downstream plasma state and implementation in Rankine-Hugoniot relations.

  5. Low dose lopinavir/ritonavir tablet achieves adequate pharmacokinetic parameters in HIV-infected Thai adolescents.

    NARCIS (Netherlands)

    Klinklom, A.; Puthanakit, T.; Gorowara, M.; Phasomsap, C.; Kerr, S.; Sriheara, C.; Ananworanich, J.; Burger, D.M.; Ruxrungtham, K.; Pancharoen, C.

    2012-01-01

    BACKGROUND: Lopinavir/ritonavir (LPV/r) is an effective and commonly used protease inhibitor in HIV-infected adolescents. Previous data showed high plasma concentrations of LPV in Thai patients. This study determined the pharmacokinetic (PK) parameters of a low-dose LPV/r tablet (70% of standard dos

  6. The effect of plasma operating parameters on analyte signals in inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Horlick, G.; Tan, S. H.; Vaughan, M. A.; Rose, C. A.

    Utilizing the SCIEX ICP-MS an extensive study of the effects that plasma operating parameters have on analyte ion signals in ICP-MS has been carried out. Parameters studied included aerosol flow rate (nebulizer pressure), auxiliary flow rate, power and sampling depth (sampling position from the load coil). The two key parameters are aerosol flow rate (nebulizer pressure) and power. Elements can be grouped into characteristic behaviour patterns based on the overall dependence of their ion count signal on these two parameters. The nebulizer pressure-power behavior patterns allow a sensible selection of compromise operating conditions and significantly clarify single parameter observations which often indicate confusing trends in behavior. In addition to characterizing analyte ion signals the parameter behavior plots have also been used to study oxide species and plus two ions in ICP-MS. While aerosol flow rate and power appear to be the key ICP parameters in ICP-MS, ion signals are dependent on sampling depth and auxiliary flow rate and some data are also presented illustrating the signal dependence on these two parameters.

  7. Use of a probing pulsed magnetic field for determining plasma parameters

    Science.gov (United States)

    Rousskikh, A. G.; Oreshkin, V. I.; Zhigalin, A. S.; Yushkov, G. Yu.

    2016-11-01

    A novel, simple, and readily usable method is proposed for measuring the electrical conductivity and temperature of a plasma. The method is based on the interaction of the test plasma with a pulsed magnetic field. The electric signals induced by the magnetic field in the circuits of two probes (miniature solenoids), one immersed in the test plasma and the other placed outside the plasma, provide data for estimating the plasma parameters. The method was verified experimentally by determining the parameters of the plasma flows generated in the cathode spots high-current pulsed vacuum arcs that were used to form cylindrical shells of bismuth Z-pinch plasma.

  8. Achieving atomistic control in materials processing by plasma-surface interactions

    Science.gov (United States)

    Chang, Jeffrey; Chang, Jane P.

    2017-06-01

    The continuous down-scaling of electronic devices and the introduction of functionally improved novel materials require a greater atomic level controllability in the synthesis and patterning of thin film materials, especially with regards to deposition uniformity and conformality as well as etching selectivity and anisotropy. The richness of plasma chemistry and the corresponding plasma-surface interactions provide the much needed processing flexibility and efficacy. To achieve the integration of the novel materials into devices, plasma-enhanced atomic layer processing techniques are emerging as the enabling factors to obtain atomic scale control of complex materials and nanostructures. This review focuses on an overview of the role of respective plasma species involved in plasma-surface interactions, addressing their respective and synergistic effects, which is followed by two distinct applications: plasma-enhanced atomic layer deposition (ALD) and atomic layer etching (ALE). For plasma-enhanced ALD, this review emphasizes the use of plasma chemistry to enable alternative pathways to synthesize complex materials at low temperatures and the challenges associated with deposition conformality. For plasma enabled ALE processes, the review focuses on the surface-specific chemical reactions needed to achieve desirable selectivity and anisotropy.

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

    Science.gov (United States)

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

    2010-11-01

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

  10. The effect of thermophoresis on the discharge parameters in complex plasma experiments

    CERN Document Server

    Land, Victor; Creel, James; Schmoke, Jimmy; Cook, Mike; Matthews, Lorin; Hyde, Truell

    2010-01-01

    Thermophoresis is a tool often applied in complex plasma experiments. One of the usual stated benefits over other experimental tools is that changes induced by thermophoresis neither directly depend on, nor directly influence, the plasma parameters. From electronic data, plasma emission profiles in the sheath, and Langmuir probe data in the plasma bulk, we conclude that this assumption does not hold. An important effect on the levitation of dust particles in argon plasma is observed as well. The reason behind the changes in plasma parameters seems to be the change in neutral atom density accompanying the increased gas temperature while running at constant pressure.

  11. The effect of electrode heating on the discharge parameters in complex plasma experiments

    Energy Technology Data Exchange (ETDEWEB)

    Land, Victor; Carmona-Reyes, Jorge; Creel, James; Schmoke, Jimmy; Cook, Mike; Matthews, Lorin; Hyde, Truell, E-mail: victor_land@baylor.edu [Center for Astrophysics, Space Physics, and Engineering Research, Baylor University, Waco, TX, 76798-7316 (United States)

    2011-02-15

    Thermophoresis is a tool often applied in complex plasma experiments. One of the usual stated benefits over other experimental tools is that electrode temperature changes required to induce thermophoresis do not directly influence the plasma parameters. From electronic data, plasma emission profiles in the sheath, and Langmuir probe data in the plasma bulk, we conclude that this assumption does not hold. An important effect on the levitation of dust particles in argon plasma is observed as well. The reason behind the changes in plasma parameters seems to be the change in neutral atom density accompanying the increased gas temperature while running at constant pressure.

  12. Nonlinear Optical Parameters of Magnetoactive Semiconductor-Plasmas

    Science.gov (United States)

    Singh, M.; Joseph, D.; Duhan, S.

    The nonlinear optical parameters (absorption coefficient and refractive index) of semiconductor-plasmas subjected to a transverse magnetic field have been investigated analytically. By employing the coupled-mode scheme, an expression of third-order optical susceptibility and resultant nonlinear absorption and refractive index of the medium are obtained. The analysis has been applied to both cases, viz., centrosymmetric (β = 0) and noncentrosymmetric (β ≠ 0) in the presence of magnetic field. The numerical estimates are made for InSb crystal at liquid nitrogen temperature duly irradiated by a 10-nanosecond pulsed 10.6 μm CO2 laser. The influence of doping concentration and magnetic field on both the nonlinear absorption and refractive index has been explored, and the results are found to be well in agreement with theory and experiment. Analysis further establishes that absorption coefficient and refractive index can be controlled with precision in semiconductors by the proper selection of doping concentration and an external magnetic field, and hence these media may be used for fabrication of fast cubic nonlinear optical devices under off-resonant transition regime.

  13. Spectroscopic studies of the parameters of plasma jets during their propagation in the background plasma on the PF-3 facility

    Science.gov (United States)

    Dan’ko, S. A.; Ananyev, S. S.; Kalinin, Yu G.; Krauz, V. I.; Myalton, V. V.

    2017-04-01

    This paper presents measurement results of neon and helium plasma parameters in axial jets generated in plasma focus discharge. They were obtained in the course of experiments on laboratory modeling of astrophysical jets performed at the PF-3 facility. The plasma concentration was determined according to Stark broadening of spectral lines; the ionization temperature was determined by the average ion charge. The values of the concentration and temperature of jet plasma and background plasma at two distances from the pinch are also presented. In addition, an estimation was made of the heat content losses of the neon and helium jets during their movement through the surrounding medium.

  14. An Empirical Investigation of Variance Design Parameters for Planning Cluster-Randomized Trials of Science Achievement.

    Science.gov (United States)

    Westine, Carl D; Spybrook, Jessaca; Taylor, Joseph A

    2013-12-01

    Prior research has focused primarily on empirically estimating design parameters for cluster-randomized trials (CRTs) of mathematics and reading achievement. Little is known about how design parameters compare across other educational outcomes. This article presents empirical estimates of design parameters that can be used to appropriately power CRTs in science education and compares them to estimates using mathematics and reading. Estimates of intraclass correlations (ICCs) are computed for unconditional two-level (students in schools) and three-level (students in schools in districts) hierarchical linear models of science achievement. Relevant student- and school-level pretest and demographic covariates are then considered, and estimates of variance explained are computed. Subjects: Five consecutive years of Texas student-level data for Grades 5, 8, 10, and 11. Science, mathematics, and reading achievement raw scores as measured by the Texas Assessment of Knowledge and Skills. Results: Findings show that ICCs in science range from .172 to .196 across grades and are generally higher than comparable statistics in mathematics, .163-.172, and reading, .099-.156. When available, a 1-year lagged student-level science pretest explains the most variability in the outcome. The 1-year lagged school-level science pretest is the best alternative in the absence of a 1-year lagged student-level science pretest. Science educational researchers should utilize design parameters derived from science achievement outcomes. © The Author(s) 2014.

  15. Parameters influencing plasma column potential in a reflex discharge

    Science.gov (United States)

    Liziakin, G. D.; Gavrikov, A. V.; Murzaev, Y. A.; Usmanov, R. A.; Smirnov, V. P.

    2016-12-01

    Distribution of electrostatic potential in direct current reflex discharge plasma has been studied experimentally. Measurements have been conducted by the single floating probe method. The influence of 0-0.2 T magnetic field, 1-200 mTorr pressure, 0-2 kV discharge voltage, and electrodes geometry on plasma column electrostatic potential was investigated. The possibility for the formation of a preset potential profile required for the realization of plasma separation of spent nuclear fuel was demonstrated.

  16. Multi-parameter gradient procedure for polarimetry data inversion in tokamak plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chrzanowski, J., E-mail: j.chrzanowski@am.szczecin.pl [Maritime University, Szczecin Wały Chrobrego 1/2 (Poland); Kravtsov, Yu. A. [Maritime University, Szczecin Wały Chrobrego 1/2 (Poland); Mazon, D. [Association Euratom/CEA, CEA Cadarache DSM/IRFM, 13108 St. Paul lez Durance Cedex (France); JET, Culham (United Kingdom)

    2013-10-15

    Highlights: ► We use gradient procedure to fit plasma parameters to polarimetric data. ► Calculations are performed in developed by authors angular variables technique. ► Numerical results are compared with experimentally measured angular parameters. ► We observe satisfied accuracy of inversion procedure after several iterations. -- Abstract: Multi-parameter gradient procedure is suggested which allows fitting tokamak plasma model to polarimetric data. One of the simplest version of gradient procedure deals with four parameters model: maximum values of electron density, maximum value of electric current density in plasma, common radius of electron density, electric current distributions and increment of the safety factor inside plasma. Using recently developed by authors angular variables technique (AVT) in plasma polarimetry we may compute angular parameters of polarization ellipse for a given set of four plasma parameters and compare them with experimentally measured angular parameters. With angular parameters, measured in two channels polarimetric system (two azimuthal and two ellipticity angles, totally four experimental values). Applying then gradient procedure for squared difference between computed and measured parameters, we find four parameters of plasma model and thereby perform inversion of polarimetric data. Numerical simulations have approved that gradient procedure provides acceptable accuracy of inversion already after several iterations.

  17. Synthesis of Single Wall Carbon Nanotubes by Plasma Arc: Role of Plasma Parameters

    Science.gov (United States)

    Farhart, Samir; Scott, Carl D.

    2000-01-01

    Single wall carbon nanotubes (SWNT) are porous objects on the molecular scale and have a low density, which gives them potential applications as adsorbent for molecular hydrogen. Their H2 absorption capacity published in the literature varies from 4 to 10% by mass according to the purity of the materials and storage conditions. Optimization of production methods of SWNTs should permit improving these new materials for storage of hydrogen. In this article, we show the potential of using SWNTs in hydrogen storage. In particular, we pose problems associated with synthesis, purification, and opening up of the nanotubes. We present an electric arc process currently used at laboratory scale to produce single wall carbon nanotubes. We discuss, in particular, operating conditions that permit growth of nanotubes and some plasma parameters that assure control of the material. Analysis of the process is carried out with the aid of local measurements of temperature and scanning and transmission electron microscopy of the materials.

  18. Effect of plasma parameters on characteristics of silicon nitride film deposited by single and dual frequency plasma enhanced chemical vapor deposition

    Science.gov (United States)

    Sahu, B. B.; Yin, Yongyi; Han, Jeon G.

    2016-03-01

    This work investigates the deposition of hydrogenated amorphous silicon nitride films using various low-temperature plasmas. Utilizing radio-frequency (RF, 13.56 MHz) and ultra-high frequency (UHF, 320 MHz) powers, different plasma enhanced chemical vapor deposition processes are conducted in the mixture of reactive N2/NH3/SiH4 gases. The processes are extensively characterized using different plasma diagnostic tools to study their plasma and radical generation capabilities. A typical transition of the electron energy distribution function from single- to bi-Maxwellian type is achieved by combining RF and ultra-high powers. Data analysis revealed that the RF/UHF dual frequency power enhances the plasma surface heating and produces hot electron population with relatively low electron temperature and high plasma density. Using various film analysis methods, we have investigated the role of plasma parameters on the compositional, structural, and optical properties of the deposited films to optimize the process conditions. The presented results show that the dual frequency power is effective for enhancing dissociation and ionization of neutrals, which in turn helps in enabling high deposition rate and improving film properties.

  19. Integral electrical characteristics and local plasma parameters of a RF ion thruster

    Energy Technology Data Exchange (ETDEWEB)

    Masherov, P. E.; Riaby, V. A., E-mail: riaby2001@yahoo.com [Research Institute of Applied Mechanics and Electrodynamics of the Moscow Aviation Institute (National Research University), Moscow (Russian Federation); Godyak, V. A. [Electrical Engineering and Computer Science Department, University of Michigan, Ann Arbor, Michigan 48109, USA and RF Plasma Consulting, Brookline, Massachusetts 02446 (United States)

    2016-02-15

    Comprehensive diagnostics has been carried out for a RF ion thruster based on inductively coupled plasma (ICP) source with an external flat antenna coil enhanced by ferrite core. The ICP was confined within a cylindrical chamber with low aspect ratio to minimize plasma loss to the chamber wall. Integral diagnostics of the ICP electrical parameters (RF power balance and coil current) allowed for evaluation of the antenna coils, matching networks, and eddy current loss and the true RF power deposited to plasma. Spatially resolved electron energy distribution functions, plasma density, electron temperatures, and plasma potentials were measured with movable Langmuir probes.

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

    Directory of Open Access Journals (Sweden)

    Kechagias John

    2017-01-01

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

  1. Plasma protein-binding parameters of prednisolone in immune disease patients receiving long-term prednisone therapy.

    Science.gov (United States)

    Wagner, J G; Wexler, D; Ağabeyoğlu, I T; Bergstrom, R F; Sakmar, E; Kay, D R

    1981-04-01

    Prednisone and prednisolone bind in plasma to albumin and transcortin. In am attempt to determine whether prednisone side effects and/or type of disease correlated with prednisolone plasma protein binding, multiple plasma samples from 17 patients (three asthma, eight SLE, three RA, two PSS, one PAN) receiving long-term prednisone therapy were monitored during an interval between two prednisone doses. Prednisolone plasma protein binding was nonlinear and exhibited large intrapatient and interpatient variability. For the group, mean association constants of the prednisolone-albumin complex and the prednisolone-transcortin complex were 2.3 X 10(3) M-1 and 2.9 X 10(7) M-1, with coefficients of variation of 82% and 127%, respectively. SLE patients tended to have lower mean prednisolone association constants for albumin and transcortin than did other patients. The presence of corticosteroid side effects did not correlate with prednisolone plasma protein-binding parameters. The wide range of prednisolone free fraction noted in plasma from patients who achieved comparable total prednisolone plasma concentrations implies that administration of a uniform prednisone dose will not lead to a predictable clinical response.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wimmer, C.; Fantz, U. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2015-04-08

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

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

    Science.gov (United States)

    Wimmer, C.; Fantz, U.

    2015-04-01

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

  4. Increasing plasma parameters using sheared flow stabilization of a Z-pinch

    Science.gov (United States)

    Shumlak, U.; Nelson, B. A.; Claveau, E. L.; Forbes, E. G.; Golingo, R. P.; Hughes, M. C.; Oberto, R. J.; Ross, M. P.; Weber, T. R.

    2017-05-01

    The ZaP and ZaP-HD Flow Z-pinch experiments at the University of Washington have successfully demonstrated that sheared plasma flows can be used as a stabilization mechanism over a range of parameters that has not previously been accessible to long-lived Z-pinch configurations. The stabilization is effective even when the plasma column is compressed to small radii, producing predicted increases in magnetic field and electron temperature. The flow shear value, extent, and duration are shown to be consistent with theoretical models of the plasma viscosity, which places a design constraint on the maximum axial length of a sheared flow stabilized Z-pinch. Measurements of the magnetic field topology indicate simultaneous azimuthal symmetry and axial uniformity along the entire 100 cm length of the Z-pinch plasma. Separate control of plasma acceleration and compression has increased the accessible plasma parameters and has generated stable plasmas with radii of 0.3 cm, as measured with a high resolution digital holographic interferometer. Compressing the plasma with higher pinch currents has produced high magnetic fields (8.5 T) and electron temperatures (1 keV) with an electron density of 2 ×1017 cm-3, while maintaining plasma stability for many Alfvén times (approximately 50 μs). The results suggest that sheared flow stabilization can be applied to extend Z-pinch plasma parameters to high energy densities.

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

    Directory of Open Access Journals (Sweden)

    Bijal Vara

    2014-03-01

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

  6. Determination of Some Biochemical Parameters in the Seminal Plasma of German Shepherd Dogs

    OpenAIRE

    GÜNAY, Ülgen

    2003-01-01

    In this study, we aimed to determine the levels of some biochemical parameters in the seminal plasma of German Shepherd dogs. Seven German Shepherd dogs were used as materials. A total of 35 ejaculates, five from each dog, were collected. The seminal plasma of each ejaculate was separated by centrifugation at 5000 rpm for 10 min. Biochemical analyses of the seminal plasma were performed. In conclusion, the average concentrations of total protein, calcium, phosphorus, magnesium, sodium and pot...

  7. Plasma polymers deposited in atmospheric pressure dielectric barrier discharges: Influence of process parameters on film properties

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Katja, E-mail: k.fricke@inp-greifswald.de [Leibniz Institute for Plasma Science and Technology e.V. (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Girard-Lauriault, Pierre-Luc [Plasma Processing Laboratory, Department of Chemical Engineering, McGill University, 3610 rue University, Montreal, QC H3A 0C5 (Canada); Weltmann, Klaus-Dieter [Leibniz Institute for Plasma Science and Technology e.V. (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Wertheimer, Michael R. [Department of Engineering Physics, École Polytechnique de Montréal, Box 6079, Station Centre-Ville, Montreal, QC H3C 3A7 (Canada)

    2016-03-31

    We present results on the deposition of plasma polymer (PP) films in a dielectric barrier discharge system fed with mixtures of argon or nitrogen carrier gas plus different hydrocarbon precursors, where the latter possess different carbon-to-hydrogen ratios: CH{sub 4} < C{sub 2}H{sub 6} < C{sub 2}H{sub 4} = C{sub 3}H{sub 6} < C{sub 2}H{sub 2}. The influence of precursor gas mixture and flow rate, excitation frequency, and absorbed power on PP film compositions and properties has been investigated. The discharge was characterized by electrical measurements, while the chemical compositions and structures of coatings were analysed by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, total combustion, and elastic recoil detection analyses, the latter two for determining carbon-to-hydrogen ratios. Scanning electron microscopy was used to study the coatings' morphology, and profilometry for evaluating deposition rates. - Highlights: • Atmospheric pressure DBD is used to deposit organic hydrocarbon films. • High deposition rates can be achieved by varying the power and/or gas mixture ratio. • Process parameters affect the films' surface chemical composition and morphology. • Deposited films are not soluble in aqueous environment. • No delamination of coatings produced from argon plasma.

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

    Directory of Open Access Journals (Sweden)

    Agnieszka Skoczylas

    2015-08-01

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

  9. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    Science.gov (United States)

    Yang, Ding-Xin; Gu, Feng-Shou; Feng, Guo-Jin; Yang, Yong-Min; Ball, Andrew

    2015-11-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications. Project supported by the National Natural Science Foundation of China (Grant No. 51379526).

  10. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    Institute of Scientific and Technical Information of China (English)

    杨定新; 谷丰收; 冯国金; 杨拥民

    2015-01-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications.

  11. Alteration of Lysophosphatidylcholine-Related Metabolic Parameters in the Plasma of Mice with Experimental Sepsis.

    Science.gov (United States)

    Ahn, Won-Gyun; Jung, Jun-Sub; Kwon, Hyeok Yil; Song, Dong-Keun

    2017-04-01

    Plasma concentration of lysophosphatidylcholine (LPC) was reported to decrease in patients with sepsis. However, the mechanisms of sepsis-induced decrease in plasma LPC levels are not currently well known. In mice subjected to cecal ligation and puncture (CLP), a model of polymicrobial peritoneal sepsis, we examined alterations in LPC-related metabolic parameters in plasma, i.e., the plasma concentration of LPC-related substances (i.e., phosphatidylcholine (PC) and lysophosphatidic acid (LPA)), and activities or levels in the plasma of some enzymes that can be involved in the regulation of plasma LPC concentration (i.e., secretory phospholipase A2 (sPLA2), lecithin:cholesterol acyltransferase (LCAT), acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT), and autotaxin (ATX)), as well as plasma albumin concentration. We found that levels of LPC and albumin and enzyme activities of LCAT, ATX, and sPLA2 were decreased, whereas levels of PC, LPA, and LPCAT1-3 were increased in the plasma of mice subjected to CLP. Bacterial peritonitis led to alterations in all the measured LPC-related metabolic parameters in the plasma, which could potentially contribute to sepsis-induced decrease in plasma LPC levels. These findings could lead to the novel biomarkers of sepsis.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

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

  13. Results from D-T Experiments on TFTR and Implications for Achieving an Ignited Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hawryluk, R.J. and the TFTR Group

    1998-07-14

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

  14. Influence of direct current plasma magnetron sputtering parameters on the material characteristics of polycrystalline copper films

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.-Y. [Thin Film Laboratory, Faculty of Engineering, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor (Malaysia)], E-mail: k.y.chan@fz-juelich.de; Luo, P.-Q.; Zhou, Z.-B. [Department of Physics, Shanghai Jiao Tong University, 800 Dongchuan Road, 200240 Shanghai (China); Tou, T.-Y.; Teo, B.-S. [Thin Film Laboratory, Faculty of Engineering, Multimedia University, Jalan Multimedia, 63100 Cyberjaya, Selangor (Malaysia)

    2009-03-01

    Physical vapor processes using glow plasma discharge are widely employed in microelectronic industry. In particular magnetron sputtering is a major technique employed for the coating of thin films. This paper addresses the influence of direct current (DC) plasma magnetron sputtering parameters on the material characteristics of polycrystalline copper (Cu) thin films coated on silicon substrates. The influence of the sputtering parameters including DC plasma power and argon working gas pressure on the electrical and structural properties of the thin Cu films was investigated by means of surface profilometer, four-point probe and atomic force microscopy.

  15. Seminal plasma zinc level may be associated with the effect of cigarette smoking on sperm parameters.

    Science.gov (United States)

    Liu, R-Z; Gao, J-C; Zhang, H-G; Wang, R-X; Zhang, Z-H; Liu, X-Y

    2010-01-01

    The aim of this study was to investigate the effect of cigarette smoking on seminal plasma zinc levels and sperm parameters, and to examine the role of seminal plasma zinc. Semen samples from 79 non-smokers and 68 smokers were obtained. There was a significant decrease in seminal plasma zinc in smokers and a clear correlation between seminal plasma zinc levels and the extent of smoking. Sperm parameters (concentration, motility and morphology) among smokers were significantly lower in comparison to non-smokers. These parameters were also significantly decreased among smokers with abnormal zinc levels, while there was no significant difference between non-smokers with normal zinc and non-smokers with abnormal zinc levels. As previous studies have shown that seminal plasma zinc is associated with a decrease of anti-oxidant defences, seminal plasma zinc could be a contributor to the effects of cigarette smoking on sperm parameters. In conclusion, cigarette smoking can affect sperm parameters and this study may help towards providing a mechanistic explanation.

  16. Effects of cigarette smoking on hemorheologic parameters, plasma osmolality and lung function.

    Science.gov (United States)

    Ergun, Dilek Duzgun; Karis, Denizhan; Alkan, Fatma Ates; Cakmak, Gulfidan; Yenigun, Mustafa; Ercan, Meltem

    2016-10-05

    Cigarette smoking deteriorates human health via vascular disorders, cancer and especially respiratory diseases. The aim of this study is to investigate effects of cigarette smoking on hemorheologic parameters, plasma osmolality and lung function in individuals without diagnosis of chronic obstructive pulmonary disease (COPD). Patients diagnosed without COPD utilizing respiratory function test were enrolled in the study with three groups, ex-smokers (n = 21), current-smokers (n = 35) and never-smokers (n = 43). Hemorheologic parameters and plasma osmolality were measured in hemorheology laboratory. SPSS 17.0 was used for statistical analysis. Blood and plasma viscosity, fibrinogen and hematocrit levels, mean corpuscular volume and mean corpuscular hemoglobin concentration were significantly elevated in ex-smokers and current-smokers compared to never-smokers. The standardized red blood cell deformability and oxygen delivery index and lung function were statistically lower in current-smokers than never-smokers. Pulmonary blood flow rate was statistically lower in current-smokers and ex-smokers than never-smokers. Plasma osmolality was statistically significantly higher in ex-smokers and current-smokers than never-smokers. Our findings clearly show that cigarette smoking has severe effects on hemorheologic parameters, plasma osmolality and lung function even in individuals without COPD. Blood and plasma viscosity with plasma osmolality might be useful markers to detect early hemorheologic-hemodynamic alterations in cigarette smokers.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hawryluk, R.J.; Blanchard, W. [Princeton Univ., NJ (United States). Princeton Plasma Physics Lab.; Batha, S. [Fusion Physics and Technology, Torrance, CA (United States)] [and others

    1998-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

  19. Effect of magnetic barrier on the plasma parameters in a Trimix-M galatea

    Science.gov (United States)

    Morozov, A. I.; Bugrova, A. I.; Bishaev, A. M.; Lipatov, A. S.; Kozintseva, M. V.

    2006-11-01

    The parameters of plasma trapped in a Trimix-M galatea with increased values of the magnetic barrier and the energy of a hydrogen plasma bunch injected in the trap have been determined. For a barrier magnetic field of B b ˜ 0.1 T, the plasma confinement time in the trap is τp ≈ 300 μs (which agrees with estimates obtained using formulas describing the classical transfer), the maximum electron density is n e ˜ 5 × 1013 cm-3, and the electron and ion temperatures are T e ≈ 20 eV and T i ˜ 2T e, respectively. The energy of trapped plasma is ˜110 J, and the ratio of the gaskinetic to magnetic pressure in the plasma is β0 ˜ 0.2.

  20. Plasma parameter characterization of a dc multicusp plasma chamber operating in He, Ar and Xe gas

    Energy Technology Data Exchange (ETDEWEB)

    Suanpoot, Pradoong; Vilaithong, Thiraphat; Boonyawan, Dheerawan [Fast Neutron Research Facility, Dept. of Physics, Faculty of Science, Chiang Mai Univ. (Thailand); Rhodes, M.W.

    1998-12-31

    A large dc multicusp plasma chamber has been constructed and installed at Chiang Mai University. The first prototype has a 31.2 cm diameter and a 42.5 cm length and is surrounded by 632 ceramic permanent magnet buttons with a maximum magnetic field of about 2.2 kG for each. The magnetic field at the stainless steel wall with a thickness of 2 mm is about 670 G. A tungsten (W) filament was used as a source of primary electrons. The estimated discharge voltage for helium gas (He), argon gas (Ar), and xenon gas (Xe) was 40 V and the discharge operating current varies from 500 mA to 1 A. Plasmas can be confined within a 20 cm diameter region which are uniformly distributed along the axial path. The plasma density was measured by a single cylindrical Langmuir probe to be between 4.8 x 10{sup 8} - 4.9 x 10{sup 9} cm{sup -3} with 650 watts of power applied to the tungsten filament and the gas pressure inside the chamber of 3.8 x 10{sup -4} Torr. Results of the ion density measurements are described. The proportionality constants in the relation between the ion current density arriving at the plasma electrode and the maximum plasma density and the ion sound speed for helium, argon and xenon are found to be 0.42 {+-} 0.07, 0.59 {+-} 0.08, and 0.46 {+-} 0.06, respectively. (author)

  1. Impact of plasma parameter on self-organization of electron temperature gradient driven turbulence

    Science.gov (United States)

    Kawai, C.; Idomura, Y.; Maeyama, S.; Ogawa, Y.

    2017-04-01

    Self-organization in the slab electron temperature gradient driven (ETG) turbulence is investigated based on gyrokinetic simulations and the Hasegawa-Mima (HM) equation. The scale and the anisotropy of self-organized turbulent structures vary depending on the Rhines scale and the characteristic scale given by the adiabatic response term in the HM equation. The former is determined by competition between the linear wave dispersion and the nonlinear turbulent cascade, while the latter is given as the scale, at which the turbulent cascade is impeded. These scales are controlled by plasma parameters such as the density and temperature gradient, and the temperature ratio of ion to electron. It is found that depending on the plasma parameters, the ETG turbulence shows either isotropic turbulence or zonal flows, which give significantly different transport levels. Although the modulational instability excites zonal modes regardless of the plasma parameters, the final turbulent structure is determined by the self-organization process.

  2. Variation of plasma parameters of vacuum arc column with gap distance

    Science.gov (United States)

    Han, Wen; Yuan, Zhao; He, Junjia

    2016-07-01

    On the basis of a two-dimensional (2D) magneto-hydrodynamic model, we studied long-gap-distance vacuum arcs in a uniform axial magnetic field and determined the effect of gap distance varying in a large range on plasma parameters. Simulation results showed that with increasing gap distance, the parameters of the plasma near the cathode are almost invariant, except for ion number density, but the parameters of the plasma in front of the anode clearly vary; meanwhile, joule heat gradually becomes the main source of energy for the arc column. In a short gap, a clear current constriction can be found in the entire arc column. Whereas when the gap distance exceeds a certain value, a sharp contraction of the current only arises in front of the anode.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    plasma parameters by the optical and Langmuir probes are presented. It is shown that the spatial profiles of the electron density, the effective electron temperature and plasma potential feature a great deal of the radial and axial uniformity compared with conventional sources of inductively coupled......A new source of low-frequency (0.46 MHz) inductively coupled plasmas sustained by the internal planar "unidirectional" RF current driven through a specially designed internal antenna configuration has been developed. The experimental results of the investigation of the optical and global argon...... applications and surface engineering. (c) 2005 Elsevier B.V. All rights reserved....

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

    Directory of Open Access Journals (Sweden)

    Jia Ge

    2014-01-01

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

  5. Diagnostics of recombining laser plasma parameters based on He-like ion resonance lines intensity ratios

    Science.gov (United States)

    Ryazantsev, S. N.; Skobelev, I. Yu; Faenov, A. Ya; Pikuz, T. A.; Grum-Grzhimailo, A. N.; Pikuz, S. A.

    2016-11-01

    While the plasma created by powerful laser expands from the target surface it becomes overcooled, i.e. recombining one. Improving of diagnostic methods applicable for such plasma is rather important problem in laboratory astrophysics nowadays because laser produced jets are fully scalable to young stellar objects. Such scaling is possible because of the plasma hydrodynamic equations invariance under some transformations. In this paper it is shown that relative intensities of the resonance transitions in He-like ions can be used to measure the parameters of recombining plasma. Intensity of the spectral lines corresponding to these transitions is sensitive to the density in the range of 1016-1020 cm-3 while the temperature ranges from 10 to 100 eV for ions with nuclear charge Zn ∼ 10. Calculations were carried out for F VIII ion and allowed to determine parameters of plasma jets created by nanosecond laser system ELFIE (Ecole Polytechnique, France) for astrophysical phenomenon modelling. Obtained dependencies are quite universal and can be used for any recombining plasma containing He-like fluorine ions.

  6. Techniques for mass resolution improvement achieved by typical plasma mass analyzers: Modeling and simulations

    Science.gov (United States)

    Nicolaou, Georgios; Yamauchi, Masatoshi; Wieser, Martin; Barabash, Stas; Fedorov, Andrei

    2016-04-01

    Mass separation and particularly distinction between atomic ions and molecular ions are essential in understanding a wide range of plasma environments, with each consisted of different species with various properties. In this study we present the optimization results of light-weight (about 2 kg) magnetic mass analyzers with high g-factor for Rosetta (Ion Composition Analyser: ICA) and for Mars Express and Venus Express (Ion Mass Analyser: IMA). For the instrument's optimization we use SIMION, a 3D ion tracing software in which we can trace particle beams of several energies and directions, passing through the instrument's units. We first reproduced ICA and IMA results, which turned out to be different from simple models for low energy (< 100 eV). We then change the mechanical structure of several units of the instrument and we quantify the new mass resolution achieved with each change. Our goal is to find the optimal instrument's structure, which will allow us to achieve a proper mass resolution to distinguish atomic nitrogen from atomic oxygen for the purposes of a future magnetospheric mission.

  7. Measurements of egg shell plasma parameters using laser-induced breakdown spectroscopy

    Indian Academy of Sciences (India)

    Wenfeng Luo; Xiaoxia Zhao; Shuyuan Lv; Haiyan Zhu

    2015-07-01

    Measurements of 1064 nm laser-induced egg shell plasma parameters are presented in this paper. Of special interests were its elemental identification and the determination of spectroscopic temperature and electron density. The electron temperature of 5956 K was inferred using an improved iterative Boltzmann plot method with six calcium atomic emission lines, and the electron number density of 6.1 × 1016 cm−3 was determined by measuring the width of Stark-broadened once-ionized calcium line at 393.37 nm. Based on the experimental results, the laser-induced egg shell plasma was verified to be optically thin and satisfy local thermodynamic equilibrium (LTE). Furthermore, experiments also demonstrated that the loss of energy due to the reflection of the laser beam from the plasma can be neglected and the inverse bremsstrahlung (IB) absorption was the dominant mechanism of plasma heating at the IR wavelength.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    In this work, we analyze the effects of Lindhard polarization parameter, χ, on the sum rule, Sp, within the local plasma approximation (LPA) as well as on the logarithmic sum rule Lp = dSp/dp, in both cases for the system in an initial excited state. We show results for a hydrogenic atom with nuc...

  9. Measurement Of Plasma Parameters In Micro-Discharge By Wall Probe

    Science.gov (United States)

    Saifutdinov, Almaz; Kudryavtsev, Anatoly; Sysoev, Sergey

    2016-09-01

    The increasing scientific and practical interest for glow discharge at high pressure is largely determined by the fact that their use does not require expensive and huge vacuum equipment. The analysis shows that, in contrast to the well-studied positive column (PC), the basic parameters of the plasma negative glow (NG) and Faraday dark space (FDS) of micro-discharges are studied insufficiently. The difficulties of the experimental diagnostics are associated with the fact that for the fixed values of pL with the increasing gas pressure the length of the micro-discharge decreases. And a small size is extremely difficult to diagnose spatial parameters distribution of micro discharges. Since at a small size introducing traditional Langmuir probe into the plasma capacity is not possible technically, it was proposed to use an additional measuring electrode (wall probe) disposed between the cathode and the anode for measurement of the fast EEDF. With its use we have registered EEDF fast electrons produced in the reaction of Penning ionization out of earlier reach range of high-pressure gas (from 20 to 200 Torr). In this paper by using wall probe we measured the basic parameters of NG plasma in micro-discharge in helium in a wide range of pressures. It is shown that the electrons temperature in the NG plasma is low and amounts to few fraction of 1 eV, which differs from the electron temperature in PC plasma. This allows the use of NG plasma for analysis by gas plasma electron spectroscopy. Authors thanks RNF (Grant 14-19-00311) for the support.

  10. Investigation of Normalization Methods using Plasma Parameters for Laser Induced Breakdown Spectroscopy (LIBS) under simulated Martian Conditions

    OpenAIRE

    Vogt, David; Schröder, Susanne; Hübers, H.-W.

    2017-01-01

    Laser Induced Breakdown Spectroscopy data need to be normalized, especially in the field of planetary exploration We investigated plasma parameters as temperature and electron density for this purpose.

  11. The effect of degeneracy parameter on Weibel instability in dense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Mahdavi, M. [Physics Department, Mazandaran University, P.O. Box 47415-416 Babolsar (Iran, Islamic Republic of); Khodadadi Azadboni, F. [Physics Department, Mazandaran University, P.O. Box 47415-416 Babolsar (Iran, Islamic Republic of); Young Researchers Club, Sari Branch, Islamic Azad University, P.O. Box 48161-194 Sari (Iran, Islamic Republic of)

    2013-12-15

    In this paper, the role of degeneracy parameter, in both directions parallel and perpendicular with propagation direction of the laser beam in plasma, on the growth rate of Weibel instability, is studied. Calculations show that with the temperature anisotropy, β = T{sub ∥}/T{sub ⊥} = 0.2 and a 0.75 times reduction of the degeneracy parameter, the increased rate of the the Weibel instability growth rate is 72%. The degeneracy required for minimal growth rate in interaction laser plasma with a density of 1.2 × 10{sup 32}m{sup −3}, is larger than 3. The reduction of temperature and the degeneracy parameter of plasma in parallel direction will also increase growth rate about 30% more than incrossing degeneracy parameter in transverse direction. With the minimum pressure costs of cold compression, subsequent degeneracy parameters, and the minimum value of electron quiver energy, we can expect growth rate of Weibel instability order 0.01.

  12. Evolution of plasma parameters in an Ar-N2/He inductive plasma source with magnetic pole enhancement

    Science.gov (United States)

    Maria, Younus; N, U. Rehman; M, Shafiq; M, Naeem; M, Zaka-Ul-Islam; M, Zakaullah

    2017-02-01

    Magnetic pole enhanced inductively coupled plasmas (MaPE-ICPs) are a promising source for plasma-based etching and have a wide range of material processing applications. In the present study Langmuir probe and optical emission spectroscopy were used to monitor the evolution of plasma parameters in a MaPE-ICP Ar-N2/He mixture plasma. Electron density ({n}{{e}}) and temperature ({T}{{e}}), excitation temperature ({T}{{exc}}), plasma potential ({V}{{p}}), skin depth (δ ) and the evolution of the electron energy probability function (EEPF) are reported as a function of radiofrequency (RF) power, pressure and argon concentration in the mixture. It is observed that {n}{{e}} increases while {T}{{e}} decreases with increase in RF power and argon concentration in the mixture. The emission intensity of the argon line at 750.4 nm is also used to monitor the variation of the ‘high-energy tail’ of the EEPF with RF power and gas pressure. The EEPF has a ‘bi-Maxwellian’ distribution at low RF powers and higher pressure in a pure {{{N}}}2 discharge. However, it evolves into a ‘Maxwellian’ distribution at RF powers greater than 70 W for pure {{{N}}}2, and at 50 W for higher argon concentrations in the mixture. The effect of argon concentration on the temperatures of two electron groups in the ‘bi-Maxwellian’ EEPF is examined. The temperature of the low-energy electron group {T}{{L}} shows a decreasing trend with argon addition until the ‘thermalization’ of the two temperatures occurs, while the temperature of high-energy electrons {T}{{H}} decreases continuously.

  13. Effect of Plasma Nitriding Parameters on the Wear Resistance of Alloy Inconel 718

    Science.gov (United States)

    Kovací, Halim; Ghahramanzadeh ASL, Hojjat; Albayrak, Çigdem; Alsaran, Akgün; Çelik, Ayhan

    2016-11-01

    The effect of the temperature and duration of plasma nitriding on the microstructure and friction and wear parameters of Inconel 718 nickel alloy is investigated. The process of plasma nitriding is conducted in a nitrogen-hydrogen gaseous mixture at a temperature of 400, 500 and 600°C for 1 and 4 h. The modulus of elasticity of the nitrided layer, the micro- and nanohardness, the surface roughness, the friction factor and the wear resistance of the alloy are determined prior to and after the nitriding. The optimum nitriding regime providing the best tribological characteristics is determined.

  14. Effect of process parameters on induction plasma reactive deposition of tungsten carbide from tungsten metal powder

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tungsten carbide deposit was made directly from tungsten metal powder through the reaction with methane in radio frequency induction plasma. Effect of major process parameters on the induction plasma reactive deposition of tungsten carbide was studied by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, water displacement method, and microhardness test. The results show that methane flow rate, powder feed rate, particle size, reaction chamber pressure and deposition distance have significant influences on the phase composition, density, and microhardness of the deposit. Extra carbon is necessary to ensure the complete conversion of tungsten metal into the carbide.

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

    Science.gov (United States)

    Stasiunaitiene, Egle; Kaminskiene, Lina

    2009-01-01

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

  16. Modeling a short cold cathode DC discharge device with controllable plasma parameters

    Science.gov (United States)

    Kudryavtsev, Anatoly; Adams, Steven; Demidov, Vladimir; Bogdanov, Yevgeny

    2009-11-01

    A short (without positive column) DC gas-discharge device with a cold cathode has been modeled. The device consists of the plane disk-shaped cathode and anode while the inter-electrode gap is bounded by a cylindrical wall. The cathode and anode are each 2.5 cm in diameter, and the inter-electrode gap is 12 mm. The wall is made of conducting parts divided by an insulator. The modeling has been performed for argon plasma at 1 Torr pressure. It is demonstrated in the model that spatial distributions of electron density and temperature and argon metastable atom density depend on the DC voltage applied to different conducting parts of the wall. Applied voltage can trap within the device volume energetic electrons arising from atomic and molecular processes in the plasma. This leads to a modification in the heating of slow electrons by energetic electrons and as a result modifies the controlling plasma parameters.

  17. Parameters Optimization of Plasma Hardening Process Using Genetic Algorithm and Neural Network

    Institute of Scientific and Technical Information of China (English)

    LIU Gu; WANG Liu-ying; CHEN Gui-ming; HUA Shao-chun

    2011-01-01

    Plasma surface hardening process was performed to improve the performance of the AISI 1045 carbon steel.Experiments were carried out to characterize the hardening qualities.A predicting and optimizing model using genetic algorithm-back propagation neural network(GA-BP) was developed based on the experimental results.The non-linear relationship between properties of hardening layers and process parameters was established.The results show that the GA-BP predicting model is reliable since prediction results are in rather good agreement with measured results.The optimal properties of the hardened layer were deduced from GA.And through multi optimizations,the optimum comprehensive performances of the hardened layer were as follows:plasma arc current is 90 A,hardening speed is 2.2 m/min,plasma gas flow rate is 6.0 L/min and hardening distance is 4.3 mm.It concludes that GA-BP mode developed in this study provides a promising method for plasma hardening parameters prediction and optimization.

  18. Life Prediction of Atmospheric Plasma-Sprayed Thermal Barrier Coatings Using Temperature-Dependent Model Parameters

    Science.gov (United States)

    Zhang, B.; Chen, Kuiying; Baddour, N.; Patnaik, P. C.

    2017-06-01

    The failure analysis and life prediction of atmospheric plasma-sprayed thermal barrier coatings (APS-TBCs) were carried out for a thermal cyclic process. A residual stress model for the top coat of APS-TBC was proposed and then applied to life prediction. This residual stress model shows an inversion characteristic versus thickness of thermally grown oxide. The capability of the life model was demonstrated using temperature-dependent model parameters. Using existing life data, a comparison of fitting approaches of life model parameters was performed. A larger discrepancy was found for the life predicted using linearized fitting parameters versus temperature compared to those using non-linear fitting parameters. A method for integrating the residual stress was proposed by using the critical time of stress inversion. The role of the residual stresses distributed at each individual coating layer was explored and their interplay on the coating's delamination was analyzed.

  19. Self-bias Dependence on Process Parameters in Asymmetric Cylindrical Coaxial Capacitively Coupled Plasma

    CERN Document Server

    Upadhyay, J; Popović, S; Valente-Feliciano, A -M; Phillips, L; Vušković, L

    2015-01-01

    An rf coaxial capacitively coupled Ar/Cl2 plasma is applied to processing the inner wall of superconducting radio frequency cavities. A dc self-bias potential is established across the inner electrode sheath due to the surface area difference between inner and outer electrodes of the coaxial plasma. The self-bias potential measurement is used as an indication of the plasma sheath voltage asymmetry. The understanding of the asymmetry in sheath voltage distribution in coaxial plasma is important for the modification of the inner surfaces of three dimensional objects. The plasma sheath voltages were tailored to process the outer wall by providing an additional dc current to the inner electrode with the help of an external dc power supply. The dc self-bias potential is measured for different diameter electrodes and its variation on process parameters such as gas pressure, rf power and percentage of chlorine in the Ar/Cl2 gas mixture is studied. The dc current needed to overcome the self-bias potential to make it ...

  20. The possible role of hydrogen sulfide as a modulator of hemostatic parameters of plasma.

    Science.gov (United States)

    Olas, Beata; Kontek, Bogdan

    2014-09-05

    Hydrogen sulfide (H2S) is a well known toxic gas at high levels. However, at physiological levels, H2S may play a role in the pathogenesis of various cardiovascular diseases. The objective was to study the effects of exogenous H2S on the hemostatic parameters (coagulation and fibrinolytic activity) of human plasma. Human plasma was incubated (5, 15 and 30 min) with NaHS as a H2S donor at the final concentration of 0.01-100 μM. Hemostatic factors, such as maximum velocity of clot formation, fibrin lysis half-time, the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) were estimated. Moreover, the aim of our study was to establish the influence of NaHS (10 μM; 5, 15 and 30 min) on the clot formation using the purified fibrinogen. We demonstrated that coagulation/fibrinolytic properties of human plasma incubated with NaHS were changed. APPT, PT and TT of plasma treated with NaHS at tested concentrations--0.01-100 μM were prolonged. We observed that NaHS (0.01-100 μM) reduced fibrin polymerization in whole plasma and 10 μM NaHS also reduced polymerization of purified fibrinogen. In the presence of NaHS (at the low tested concentration--1 μM) the decrease was about 18% (in plasma, p<0.05). Our experiments also showed that NaHS (0.01-100 μM) stimulated the fibrin lysis in whole plasma. However, the time-dependent (5, 15 and 30 min) reduction of fibrin/fibrinogen polymerization and stimulation of fibrin lysis by NaHS (10 μM) was not observed. In conclusion, the present study demonstrates the anticoagulant properties of exogenous H2S in vitro.

  1. Versatile particle collection concept for correlation of particle growth and discharge parameters in dusty plasmas

    Science.gov (United States)

    Hinz, A. M.; von Wahl, E.; Faupel, F.; Strunskus, T.; Kersten, H.

    2015-02-01

    The feasibility of collecting nanoparticles from a dusty plasma by means of the neutral drag force is investigated. The nanoparticles are formed in a capacitively coupled asymmetric discharge running in an Ar/C2H2—mixture at a frequency of 13.56 MHz and an RF-power of 9 W. By opening a gate valve between the plasma reactor and a vacuum chamber at a lower pressure at any desired point of the growth cycle of the dust particles a neutral gas flux is induced that drags the particles out of the plasma onto a substrate. By changing the parameters of the collection process, e.g. the substrate positioning or the substrate temperature, the efficiency of the collection process can be adjusted. Information about the particle size distributions is obtained by performing ex situ SEM measurements. As the collection process creates a time stamp in the in situ recorded control parameters, e.g. the self-bias voltage or the process gas pressure, a direct and precise correlation between the control parameters and the particle size distribution is obtained.

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

    Science.gov (United States)

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

    2015-04-23

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

  3. Modeling Approach and Analysis of the Structural Parameters of an Inductively Coupled Plasma Etcher Based on a Regression Orthogonal Design

    Institute of Scientific and Technical Information of China (English)

    CHENG Jia; ZHU Yu; JI Linhong

    2012-01-01

    The geometry of an inductively coupled plasma (ICP) etcher is usually considered to be an important factor for determining both plasma and process uniformity over a large wafer. During the past few decades, these parameters were determined by the "trial and error" method, resulting in wastes of time and funds. In this paper, a new approach of regression orthogonal design with plasma simulation experiments is proposed to investigate the sensitivity of the structural parameters on the uniformity of plasma characteristics. The tool for simulating plasma is CFD-ACE+, which is commercial multi-physical modeling software that has been proven to be accurate for plasma simulation. The simulated experimental results are analyzed to get a regression equation on three structural parameters. Through this equation, engineers can compute the uniformity of the electron number density rapidly without modeling by CFD-ACE+. An optimization performed at the end produces good results.

  4. Intrahippocampal Infusion of Crotamine Isolated from Crotalus durissus terrificus Alters Plasma and Brain Biochemical Parameters

    Directory of Open Access Journals (Sweden)

    Rithiele Gonçalves

    2014-11-01

    Full Text Available Crotamine is one of the main constituents of the venom of the South American rattlesnake Crotalus durissus terrificus. Here we sought to investigate the inflammatory and toxicological effects induced by the intrahippocampal administration of crotamine isolated from Crotalus whole venom. Adult rats received an intrahippocampal infusion of crotamine or vehicle and were euthanized 24 h or 21 days after infusion. Plasma and brain tissue were collected for biochemical analysis. Complete blood count, creatinine, urea, glutamic oxaloacetic transaminase (GOT, glutamic pyruvic transaminase (GPT, creatine-kinase (CK, creatine kinase-muscle B (CK-MB and oxidative parameters (assessed by DNA damage and micronucleus frequency in leukocytes, lipid peroxidation and protein carbonyls in plasma and brain were quantified. Unpaired and paired t-tests were used for comparisons between saline and crotamine groups, and within groups (24 h vs. 21 days, respectively. After 24 h crotamine infusion promoted an increase of urea, GOT, GPT, CK, and platelets values (p ≤ 0.01, while red blood cells, hematocrit and leukocytes values decreased (p ≤ 0.01. Additionally, 21 days after infusion crotamine group showed increased creatinine, leukocytes, TBARS (plasma and brain, carbonyl (plasma and brain and micronucleus compared to the saline-group (p ≤ 0.01. Our findings show that crotamine infusion alter hematological parameters and cardiac markers, as well as oxidative parameters, not only in the brain, but also in the blood, indicating a systemic pro-inflammatory and toxicological activity. A further scientific attempt in terms of preserving the beneficial activity over toxicity is required.

  5. Ignitor Plasma Physics Performance in the H-Regime at Various Parameters

    Science.gov (United States)

    Detragiache, P.; Coppi, B.

    2010-11-01

    The plasma physics performance of Ignitor at full (BT = 13 T, Ip = 10 MA) as well as at reduced parameters (BT = 8 T, Ip = 5 MA) in the high confinement mode (H-regime) is assessed using global 0-D modelling. At full parameters, high-Q operation is possible if the heating power (a combination of Ohmic, α and limited ICRF power) is above the threshold value Pthr for H-regime confinement. Different scaling expressions for Pthr yield significantly different results when used with Ignitor parameters. Even with the most pessimistic among the proposed scalingsootnotetextY. R. Martin et al., Journal of Physics: Conference Series, 123, 012033 (2008). the access to H-regime confinement is possible for Ignitor at full field when the ICRH system is operated at the highest frequency and the generated power is less than at lower frequencies. At reduced parameters, the lower Pthr and the augmented ICRF power available (about 10 MW) facilitate access to H-regime confinement, while the plasma performance remains respectable.

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

    Directory of Open Access Journals (Sweden)

    E. Séran

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

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

  7. A Multi-Parameter Optimization of Plasma Density for an Advanced Linear Collider*

    CERN Document Server

    Muggli, P; Hillenbrand, S

    2011-01-01

    Recent plasma wakefield accelerator (PWFA) experiments showed that an accelerating gradient as high as 50 GV/m can be driven and sustained over a meter-long plasma [1]. Based on this result, a straw man design for a future, multi-stage, PWFA-based electron/positron collider with an energy gain of ~ 25 GeV/stage has been generated [2]. However, the choice of plasma density remains open. On one hand, high density means large accelerating gradients and possibly a shorter collider. On the other it means that the accelerating structure dimensions become very small, on the order of the plasma wavelength. Operating at high gradient and with such small structure imposes very strong constraints on the particle bunches: small dimensions and spacing, large current or limited charge, etc. These constraints result is challenges in producing the bunches (compression, shaping for optimum loading, etc.) and could limit the achievable collider luminosity. We explore the global implications of operating at a lower accelerating...

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

    Science.gov (United States)

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

    1989-01-01

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

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

    Indian Academy of Sciences (India)

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

    2017-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Ales Pavlik

    2015-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-01

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

  12. Low plasma concentrations achieved with conventional schedules of administration of ganciclovir in patients with AIDS.

    Science.gov (United States)

    Piketty, C; Bardin, C; Gilquin, J; Mahe, V; Kazatchkine, M D; Chast, F

    1996-07-01

    Plasma concentration of ganciclovir was studied prospectively in 15 AIDS patients treated for acute cytomegalovirus (CMV) retinitis. Ganciclovir was administered at a mean dose of 10.3 +/- 0.6 mg/kg/day. The mean trough plasma concentration was 0.6 +/- 0.3 mg/L (n = 24), and the mean peak concentration was 7.2 +/- 2.4 mg/L (n = 6). In 12 patients, trough concentrations were below the range that has been associated with effective treatment. Low trough concentrations were associated with treatment failure in 6 patients. Following an increase in the daily dose, improvement was observed in 4 of the 6 patients. These results suggest that low plasma ganciclovir levels are associated with the failure of therapy. Monitoring the plasma concentration of ganciclovir may thus be useful before considering the virus to be resistant to the drug or before switching from ganciclovir to foscarnet.

  13. Divertor conditions relevant for fusion reactors achieved with linear plasma generator

    NARCIS (Netherlands)

    van Eck, H. J. N.; Kleyn, A. W.; Lof, A.; van der Meiden, H. J.; van Rooij, G. J.; Scholten, J.; van Emmichoven, P. A. Zeijlma

    2012-01-01

    Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6 × 1020 m−3 and electron temperatures up to 3.7 eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4 MW m−2 and 1024 m−2

  14. Divertor conditions relevant for fusion reactors achieved with linear plasma generator

    NARCIS (Netherlands)

    H.J.N. van Eck; A.W. Kleijn; A. Lof; H.J. van der Meiden; G.J. van Rooij; J. Scholten; P.A. Zeijlmans van Emmichoven

    2012-01-01

    Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6 × 10 20 m−3 and electron temperatures up to 3.7 eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4 MW m−2 and 10 24 m−

  15. Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO2 photoelectrodes

    OpenAIRE

    Dang, Binh H.Q.; MacElroy, J. M. Don; Dowling, Denis P.

    2013-01-01

    The photoactivity of carbon-incorporated titanium dioxide (TiO2) has been widely reported. This study involves a novel approach to the incorporation of carbon into TiO2 through the use of microwave plasma processing. The process involved thermally treating printed TiO2 nanoparticle coatings in a microwave-induced argon-oxygen plasma containing low concentrations of methane. The resulting deposited carbon layer was characterized using XRD, XPS, Raman, UV–vis, ellipsometry, and optical profilom...

  16. Typical Profiles and Distributions of Plasma and Magnetic Field Parameters in Magnetic Clouds at 1 AU

    Science.gov (United States)

    Rodriguez, L.; Masías-Meza, J. J.; Dasso, S.; Démoulin, P.; Zhukov, A. N.; Gulisano, A. M.; Mierla, M.; Kilpua, E.; West, M.; Lacatus, D.; Paraschiv, A.; Janvier, M.

    2016-08-01

    Magnetic clouds (MCs) are a subset of interplanetary coronal mass ejections (ICMEs). They are important because of their simple internal magnetic field configuration, which resembles a magnetic flux rope, and because they represent one of the most geoeffective types of solar transients. In this study, we analyze their internal structure using a superposed epoch method on 63 events observed at L1 by the Advance Composition Explorer (ACE), between 1998 and 2006. In this way, we obtain an average profile for each plasma and magnetic field parameter at each point of the cloud. Furthermore, we take a fixed time-window upstream and downstream from the MC to also sample the regions preceding the cloud and the wake trailing it. We then perform a detailed analysis of the internal characteristics of the clouds and their surrounding solar wind environments. We find that the parameters studied are compatible with log-normal distribution functions. The plasma β and the level of fluctuations in the magnetic field vector are the best parameters to define the boundaries of MCs. We find that one third of the events shows a peak in plasma density close to the trailing edge of the flux ropes. We provide several possible explanations for this result and investigate if the density peak is of a solar origin ( e.g. erupting prominence material) or formed during the magnetic cloud travel from the Sun to 1 AU. The most plausible explanation is the compression due to a fast overtaking flow, coming from a coronal hole located to the east of the solar source region of the magnetic cloud.

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

    Directory of Open Access Journals (Sweden)

    Agustina Dwi Wijayanti

    2010-06-01

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

  18. Selenium, copper and zinc in seminal plasma of men with varicocele, relationship with seminal parameters.

    Science.gov (United States)

    Camejo, María Isabel; Abdala, Lyzeth; Vivas-Acevedo, Giovanny; Lozano-Hernández, Ricardo; Angeli-Greaves, Miriam; Greaves, Eduardo D

    2011-12-01

    Varicocele has been associated with decrease in seminal parameters. Selenium (Se), copper (Cu), and zinc (Zn) are trace elements essential for normal spermatogenesis of mammals and play a critical role as antioxidant defense system enzymes. Se, Cu, and Zn are associated with sperm quality in fertile and infertile men. However, there is little information about Se, Cu, and Zn concentrations in semen in patients with varicocele and its association with seminal parameters. The purpose of this study was to determine the concentrations of Se, Cu, and Zn in semen of patients with varicocele and the relationship with seminal parameters. Total Reflection X-Ray Fluorescence was used for the fist time in the seminal fluid analysis. The concentration of selenium in men with varicocele was smaller than the normozoospermic group, while no differences were observed for both concentrations of zinc and copper. A significant positive correlation between zinc and selenium concentration was observed. Selenium in seminal plasma correlates with a good spermatozoa concentrations, motility, and morphology. Additionally, a significant positive correlation was observed between zinc levels and sperm count. In conclusion, a decrease in selenium concentration was associated with detriment of seminal parameters. A study should be conducted to evaluate the benefits of both zinc and selenium supplementation to improve seminal parameters in patients with varicocele.

  19. High direct drive illumination uniformity achieved by multi-parameter optimization approach: a case study of Shenguang III laser facility.

    Science.gov (United States)

    Tian, Chao; Chen, Jia; Zhang, Bo; Shan, Lianqiang; Zhou, Weimin; Liu, Dongxiao; Bi, Bi; Zhang, Feng; Wang, Weiwu; Zhang, Baohan; Gu, Yuqiu

    2015-05-04

    The uniformity of the compression driver is of fundamental importance for inertial confinement fusion (ICF). In this paper, the illumination uniformity on a spherical capsule during the initial imprinting phase directly driven by laser beams has been considered. We aim to explore methods to achieve high direct drive illumination uniformity on laser facilities designed for indirect drive ICF. There are many parameters that would affect the irradiation uniformity, such as Polar Direct Drive displacement quantity, capsule radius, laser spot size and intensity distribution within a laser beam. A novel approach to reduce the root mean square illumination non-uniformity based on multi-parameter optimizing approach (particle swarm optimization) is proposed, which enables us to obtain a set of optimal parameters over a large parameter space. Finally, this method is applied to improve the direct drive illumination uniformity provided by Shenguang III laser facility and the illumination non-uniformity is reduced from 5.62% to 0.23% for perfectly balanced beams. Moreover, beam errors (power imbalance and pointing error) are taken into account to provide a more practical solution and results show that this multi-parameter optimization approach is effective.

  20. Influence of geometrical parameters on performance of plasma synthetic jet actuator

    Science.gov (United States)

    Zong, Hao-hua; Wu, Yun; Jia, Min; Song, Hui-min; Liang, Hua; Li, Ying-hong; Zhang, Zhi-bo

    2016-01-01

    Plasma synthetic jet actuator (PSJA) has shown wide and promising application prospects in a high speed flow control field, due to its rapid response, high exhaust velocity, and non-moving components. In this paper, the total pressure profile of a plasma synthetic jet (PSJ) is measured and a new method is developed to evaluate the pulsed thrust of the PSJA. The influence of geometrical parameters including the electrode distance, the orifice diameter, and the throat length on PSJA performance is analyzed based on the pulsed thrust, the discharge characteristics, and the schlieren images. When varying the electrode distance, the dominant factor determining the jet intensity is the heating volume instead of the discharge energy. For the arc discharge, the electrode distance should be extended to increase both the jet velocity and the jet duration time. The design of the orifice diameter should be based on the controlled flow field. A large orifice diameter produces a strong perturbation with short time duration, while a small orifice diameter induces a lasting jet with low mass flux. In order to obtain better high frequency performance, the throat length should be shortened on the condition that the structural strength of the PSJA is maintained, while there is almost no influence of the throat length on the single cycle performance of the PSJA. Once the discharge energy is fixed, the pulsed thrust remains almost unchanged with different orifice diameters and throat lengths. These three geometrical parameters are independent to some extent and can be optimized separately.

  1. Plasma arc cutting optimization parameters for aluminum alloy with two thickness by using Taguchi method

    Science.gov (United States)

    Abdulnasser, B.; Bhuvenesh, R.

    2016-07-01

    Manufacturing companies define the qualities of thermal removing process based on the dimension and physical appearance of the cutting material surface. The surface roughness of the cutting area for the material and the material removal rate being removed during the manual plasma arc cutting process were importantly considered. Plasma arc cutter machine model PS-100 was used to cut the specimens made from aluminium alloy 1100 manually based on the selected parameters setting. Two different thicknesses of specimens, 3mm and 6mm were used. The material removal rate (MRR) was measured by determining the difference between the weight of specimens before and after the cutting process. The surface roughness (Ra) was measured by using MITUTOYO CS-3100 machine and analysis was conducted to determine the average roughness (Ra) value, Taguchi method was utilized as an experimental layout to obtain MRR and Ra values. The results indicate that the current and cutting speed is the most significant parameters, followed by the arc gap for both rate of material removal and surface roughness.

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

    Directory of Open Access Journals (Sweden)

    Nicholas Curry

    2015-07-01

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

  3. Relevant parameter space and stability of spherical tokamaks with a plasma center column

    Science.gov (United States)

    Lampugnani, L. G.; Garcia-Martinez, P. L.; Farengo, R.

    2017-02-01

    A spherical tokamak (ST) with a plasma center column (PCC) can be formed inside a simply connected chamber via driven magnetic relaxation. From a practical perspective, the ST-PCC could overcome many difficulties associated with the material center column of the standard ST reactor design. Besides, the ST-PCC concept can be regarded as an advanced helicity injected device that would enable novel experiments on the key physics of magnetic relaxation and reconnection. This is because the concept includes not only a PCC but also a coaxial helicity injector (CHI). This combination implies an improved level of flexibility in the helicity injection scheme required for the formation and sustainment phases. In this work, the parameter space determining the magnetic structure of the ST-PCC equilibria is studied under the assumption of fully relaxed plasmas. In particular, it is shown that the effect of the external bias field of the PCC and the CHI essentially depends on a single parameter that measures the relative amount of flux of these two entities. The effect of plasma elongation on the safety factor profile and the stability to the tilt mode are also analyzed. In the first part of this work, the stability of the system is explained in terms of the minimum energy principle, and relevant stability maps are constructed. While this picture provides an adequate insight into the underlying physics of the instability, it does not include the stabilizing effect of line-tying at the electrodes. In the second part, a dynamical stability analysis of the ST-PCC configurations, including the effect of line-tying, is performed by numerically solving the magnetohydrodynamic equations. A significant stability enhancement is observed when the PCC contains more than the 70% of the total external bias flux, and the elongation is not higher than two.

  4. GeV electron acceleration by a Gaussian field laser with effect of beam width parameter in magnetized plasma

    Science.gov (United States)

    Ghotra, Harjit Singh; Kant, Niti

    2017-01-01

    Electron acceleration due to a circularly polarized (CP) Gaussian laser field has been investigated theoretically in magnetized plasma. A Gaussian laser beam possesses trapping forces on electrons during its propagation through plasma. A single particle simulation indicates a resonant enhancement of electron acceleration with a Gaussian laser beam. The plasma is magnetized with an axial magnetic field in same direction as that of laser beam propagation. The dependence of laser beam width parameter on electron energy gain with propagation distance has been presented graphically for different values of laser intensity. Electron energy gain is relatively high where the laser beam parameter is at its minimum value. Enhanced energy gain of the order of GeV is reported with magnetic field under 20 MG in plasma. It is also seen that the axial magnetic field maintains the electron acceleration for large propagation distance even with an increasing beam width parameter.

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

    Directory of Open Access Journals (Sweden)

    Jin-Chun Lu

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

  6. Nuclear magnetic resonance-based metabonomics reveals strong sex effect on plasma metabolism in 17-year-old Scandinavians and correlation to retrospective infant plasma parameters.

    Science.gov (United States)

    Bertram, Hanne Christine; Duus, Jens Ø; Petersen, Bent O; Hoppe, Camilla; Larnkjaer, Anni; Schack-Nielsen, Lene; Mølgaard, Christian; Michaelsen, Kim F

    2009-07-01

    Nuclear magnetic resonance (NMR)-based metabonomics was carried out on plasma samples from a total of seventy-five 17-year-old Danes to investigate the impact of key parameters such as sex, height, weight, and body mass index on the plasma metabolite profile in a normal, healthy population. Principal component analysis identified sex to have a large impact on the NMR plasma metabolome, whereas no apparent effects of height, weight, and body mass index were found. Partial least square regression discriminant analysis and quantification of relative metabolite concentrations by integration of NMR signals revealed that the sex effect included differences in plasma lipoproteins (mainly high-density lipoprotein), glucose, choline, and amino acid content. Accordingly, the present study suggests a higher lipid synthesis in young women than young men and a higher protein turnover in young men compared with women. Data on plasma content of triglyceride, lipoprotein fractions, and cholesterol at an age of 9 months were available for selected individuals (n = 40); and partial least square regressions revealed correlations between these infant parameters and the NMR plasma metabolome at an age of 17 years. In conclusion, the present study demonstrates the feasibility of NMR-based metabonomics for obtaining a deeper insight into interindividual differences in metabolism and for exploring relationships between parameters measured early in life and metabolic status at a later stage.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    Organohalogen contaminants (OHCs) may affect various physiological parameters in birds including blood chemistry. We therefore examined blood plasma clinical-chemical parameters and OHCs in golden eagle, white-tailed eagle and goshawk chicks from Northern Norway. Correlation analyses on pooled da...

  8. Relation of Plasma Uric Acid Levels and the Lipid Parameters in Han and Uygur Ethnicity

    Institute of Scientific and Technical Information of China (English)

    Sun Yuping; Yao Hua; Yao Wenhai; Li Qing; You Lan; Wang Qiuyun; Jiang Yan

    2006-01-01

    Objectives Hyperuricemia is a common finding in hypertension and hyperlipidemia,they are all correlated to cardiovascular diseases. The aim of this study was to find the relationship of uric acid and plasma lipid parameters of Han and Uygur ethnicity in Xinjiang. Methods This cross-sectional health examination survey was based on a population random sample from the Urumchi, It included 1166 subjects aged from 20 to 70 years. Serum biochemical testing by Automatic Analyzer (HITACHI 7600-010).Results The uric acid in Han was higher than in Uygur(P< 0.05), men were higher than women in two ethnicities; For lipid parameters men were higher than women, in TG and HDL women were higher than in men in two ethnicity (P < 0.05). Serum uric acid was strongly related to serum triglycerides in Han as well as Uygur ethnicity ( P < 0.001); Compared with the normal group, UA, TG, CHOL, VLDL had ascending trend and HDL had descending trend (P <0.05 ) among groups in Han and Uygur ethnicity,especially Hyperuricemia-hypertriglyceridemia group,uric acid and most some lipid parameters was higher than Hyperuricemia and hypertriglyceridemia group,The prevalence of different groups in Han and Urgur was significantly different (P < 0.05). Conclusions This study shows that the UA and some lipid parameters are different in Han and Uygur ethnicity and show sexual difference; serum uric acid is markedly related to serum triglycerides; Hyperuricemia and hypertriglyceridemia show cooperated effect in uric acid and most lipid parameters. Considering the growing incidence of the potential link between hyperuricemia/hypertriglyceridemia and cardiovascular diseases, more emphasis should be put on the evolving prevalence of hyperuricemia and hypertriglyceridemia in Xinjiang.

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

    Science.gov (United States)

    Yao, Qi; Fan, Kai; Wang, Guo-Hong; Feng, Rui-Xiang; Liang, Yuan-Jiao; Chen, Li; Ge, Yi-Feng; Yao, Bing

    2016-01-01

    Objective This prospective study was designed to investigate the relationship between lipids levels in both serum and seminal plasma and semen parameters. Methods 631 subfertile men were enrolled. Their obesity-associated markers were measured, and semen parameters were analyzed. Also, seminal plasma and serum TC, TG, HDL and LDL and serum FFA, FSH, LH, total testosterone (TT), estradiol (E2) and SHBG levels were detected. Results Seminal plasma and serum TG, TC and LDL levels were positively related to age. Serum TC, TG and LDL were positively related to obesity-associated markers (P lipids levels in serum and seminal plasma, only TG level had slightly positive correlation between them (r = 0.081, P = 0.042). There was no significant correlation between serum lipids levels and semen parameters. However, seminal plasma TG, TC, LDL and HDL levels were negatively related to one or several semen parameters, including semen volume (SV), sperm concentration (SC), total sperm count (TSC), sperm motility, progressive motility (PR) and total normal-progressively motile sperm counts (TNPMS). Moreover, seminal plasma TG, TC, LDL and HDL levels in patients with oligospermatism, asthenospermia and teratozoospermia were higher than those with normal sperm concentration, motility or morphology. After adjusting age and serum LH, FSH, TT, E2 and SHBG levels, linear regression analysis showed that SV was still significantly correlated with seminal plasma LDL (P = 0.012), both of SC and TSC with seminal plasma HDL (P = 0.028 and 0.002), and both of PR and sperm motility with seminal plasma TC (P = 0.012 and 0.051). Conclusion The abnormal metabolism of lipids in male reproductive system may contribute to male factor infertility. PMID:26726884

  10. Feed gas humidity: a vital parameter affecting a cold atmospheric-pressure plasma jet and plasma-treated human skin cells

    Science.gov (United States)

    Winter, J.; Wende, K.; Masur, K.; Iseni, S.; Dünnbier, M.; Hammer, M. U.; Tresp, H.; Weltmann, K.-D.; Reuter, S.

    2013-07-01

    In this study, the effect of feed gas humidity on the reactive component generation of an atmospheric-pressure argon plasma jet and its effect on human skin cells are investigated. Feed gas humidity is identified as one key parameter that strongly influences stability and reproducibility of plasma medical studies. The plasma jet is investigated by absorption spectroscopy in the ultraviolet and infrared spectral region for its ozone production depending on the humidity concentration in the feed gas. By optical emission spectroscopy the dependence of present excited plasma species such as hydroxyl radicals, molecular nitrogen, argon and atomic oxygen on the feed gas humidity is investigated. As an interface layer between the plasma jet effluent and the biological cell, a buffer solution is treated and the hydrogen peroxide (H2O2) production is studied with two independent colorimetric assays as a function of humidity admixture to the feed gas. Ultimately, the effect of varying feed gas humidity on the cell viability of indirect plasma treated adherent HaCAT cells is investigated. The highest viability is found for the driest feed gas condition. Furthermore, this work shows answers for the relevance of unwanted—or intended—feed gas humidity in plasma medical experiments and their comparatively large relevance with respect to ambient humidity. The findings will lead to more reproducible experiments in the field of plasma medicine.

  11. Solar Cluster: multipoint magnetic field and plasma parameter measurements in the solar wind

    Science.gov (United States)

    Vieira, L. E.; Echer, E.; dal Lago, A.; Schuch, N. J.

    This paper has the objective to discus the technical-scientific feasibility of a deep space mission to be proposed to the Brazilian Space Agency (AEB). This mission will be proposed to study the interplanetary magnetic field and the plasma structure of the solar wind. It will consist of a set of identical spacecraft flying in formation in the inner heliosphere during the ascending and maximum phase of the solar cycle 24. It is know that the primary cause of magnetic storms are intense, long duration southward interplanetary magnetic field structures which interconnect with the earth's magnetic field and allow solar wind energy transport into the Earth's magnetotail/magnetosphere. During the most active phase of the solar cycle, solar maximum, the sun's activity is dominated by flares and disappearing filaments, and their concomitant Coronal Mass Ejections (CMEs). Coronal Holes are present, but the holes are small and do not extend from the poles to the equator as often happens in the descending phase of the solar cycle. The fast (>500 km/s) CMEs coming from the sun into the interplanetary space are the solar/coronal features that contain high magnetic fields. These intense southward magnetic fields are observed in the sheath, in the ejection itself and in the rear of the ejection. The interaction between CMEs and the background solar wind, fast co rotating streams and other CMEs are also very important sources of intense southward magnetic fields. In order to study the interplanetary origin of intense geomagnetic storms, several studies have analyzed plasma parameters, composition, ionization state and the interplanetary magnetic field measured by instruments on board of spacecraft as ISEE3, IMP8, Helios, Ulysses, Wind, SOHO and ACE. Great advance on the understanding of the CME structure and interaction with the background solar wind have been reached. However, the spatial scale of these structures could be greater than 0.2 AU, and this kind of observation usually

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

    Science.gov (United States)

    Lennartsson, W.; Sharp, R. D.

    1984-01-01

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

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

    Science.gov (United States)

    Lennartsson, W.; Sharp, R. D.

    1984-09-01

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

  14. Analytical estimation of particle shape formation parameters in a plasma-chemical reactor

    Directory of Open Access Journals (Sweden)

    Zhukov Ilya A.

    2017-01-01

    Full Text Available Analytical estimation of particle shape formation parameters in a plasma-chemical reactor implementing the process of thermochemical decomposition of liquid droplet agents (precursors in the flow of a high-temperature gaseous heat-transfer medium was obtained. The basic factor which determines the process is the increase of concentration of a dissolved salt precursor component at the surface of a liquid particle due to solvent evaporation. According to the physical concept of the method of integral balance the diffusion process of concentration change is divided into two stages: the first stage is when the size of gradient layer does not reach the center of a spherical droplet and the second stage when the concentration at the center of a liquid droplet begins to change. The solutions for concentration fields were found for each stage using the method of integral balance taking into account the formation of salt precipitate when the concentration at the surface of the droplet reaches certain equilibrium value. The results of estimation of the influence of various reactor operation parameters and characteristics of initial solution (precursor on the morphology of particles formed – mass fraction and localization of salt precipitate for various levels of evaporation.

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

    Directory of Open Access Journals (Sweden)

    O. S. Oyekola

    2009-01-01

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

  16. Plasma and synovial fluid concentrations of calcium pentosan polysulphate achieved in the horse following intramuscular injection.

    Science.gov (United States)

    Fuller, C J; Ghosh, P; Barr, A R S

    2002-01-01

    Results from in vitro studies have indicated that calcium pentosan polysulphate (CaPPS) may be of therapeutic value in osteoarthritis (OA) in the horse. However, no controlled clinical trials using this drug in equine OA have yet been reported. If CaPPS is to be developed for such use, the relationship between the proposed i.m. dose of CaPPS to be used and the concentrations of drug attained in plasma and synovial fluid of the target joint should first be established. An investigation was undertaken to determine these concentrations after a single 2 mg/kg i.m. injection of CaPPS. Blood and synovial fluid samples were taken from 6 healthy, sound horses following i.m. CaPPS administration. Concentrations of CaPPS measured in the synovial fluid were, on the basis of published studies, sufficient to elicit a potential therapeutic effect on synoviocyte metabolism, and possibly also to stimulate proteoglycan synthesis and reduce matrix metalloproteinase activities in articular cartilage. It would therefore seem justified to investigate further the therapeutic effect of CaPPS in OA in the horse.

  17. Behavior of Plasma and Field Parameters and their Relationship with Geomagnetic Indices during Intense Geomagnetic Storms of Solar Cycle 23

    CERN Document Server

    Joshi, Navin Chandra; Pande, Seema; Pande, Bimal; Pandey, Kavita

    2010-01-01

    A correlative study between the geomagnetic indices and the peak values of various plasma and field parameters during rising, maximum and decay phases as well as during complete solar cycle 23 have been presented. We have also presented the lag/lead analysis between the maximum of Dst and peak values of plasma and field parameters and found that peak values of lag/lead time lies in the +/-10 hr interval. Three geomagnetic storms (GMSs) and associated solar sources observed during these phases of this solar cycle have also been studied and found that GMSs are associated with large flares and halo CMEs.

  18. Levels of oxidative stress biomarkers in seminal plasma and their relationship with seminal parameters

    Directory of Open Access Journals (Sweden)

    Zarghami Nosratollah

    2007-06-01

    Full Text Available Abstract Background There is growing evidence that damage to spermatozoa by reactive oxygen species (ROS play a key role in male infertility. The aim of the present study was to assess seminal plasma levels of total antioxidant capacity (TAC, free 8-Isoprostane and activities of catalase and superoxide dismutase (SOD in men with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia compared with normozoospermic males. Methods The patients consisted of 46 men with seminal parameters abnormalities. The patients were grouped into asthenozoospermic (n = 15, asthenoteratozoospermic (n = 16 and oligoasthenoteratozoospermic (n = 15. The control group consisted of 16 healthy males with normozoospermia. Catalase activity was measured by Aebi spectrophotometeric method. Levels of TAC and SOD were measured by commercially available colorimetric assays. Level of free 8-Isoprostane was assessed by commercially available enzyme immunoassay (EIA method. Differences between groups were assessed using Mann-Whitney U test and Kruskal-Wallis test. Coefficients of correlation were calculated using Spearman's correlation analysis. All hypothesis tests were two-tailed with statistical significance assessed at the p value Results Levels of catalase and TAC were significantly lower in patients than the control group. No significant changes were seen in SOD activities. Levels of free 8-Isoprostane were significantly higher in patients than the control group. Furthermore, asthenozoospermic, asthenoteratozoospermic and oligoasthenoteratozoospermic groups had significantly lower values of catalase activity and TAC when compared to normozoospermic males. Levels of free 8-Isoprostane were significantly higher in all patients subgroups than the control group. Levels of catalase and TAC were positively correlated with sperm motility and morphology. Free 8-Isoprostane levels showed an inverse correlation with sperm motility and morphology. Conclusion

  19. Subclinical hypocalcemia, plasma biochemical parameters, lipid metabolism, postpartum disease, and fertility in postparturient dairy cows.

    Science.gov (United States)

    Chamberlin, W G; Middleton, J R; Spain, J N; Johnson, G C; Ellersieck, M R; Pithua, P

    2013-01-01

    A study was conducted to evaluate the potential association between Ca status at calving and postpartum energy balance, liver lipid infiltration, disease occurrence, milk yield and quality parameters, and fertility in Holstein cows. One hundred cows were assigned to 1 of 2 groups based on whole-blood ionized Ca concentration ([iCa]) on the day of calving [d 0; hypocalcemic [iCa] Cows were blocked based on calving date and parity. Blood samples were collected approximately 14 d from expected calving date (d -14), the day of calving (d 0), and on d 3, 7, 14, 21, and 35 postpartum for measurement of plasma nonesterified fatty acid, iCa, total Ca, glucose, and total and direct bilirubin concentrations, and plasma aspartate aminotransferase and gamma glutamyl transferase activities. Liver biopsies were obtained from a subset of cows on d 0, 7, and 35 for quantification of lipid content. Milk samples were collected on d 3, 7, 14, 21, and 35 postpartum for measurement of somatic cell count and percentages of protein, fat, and solids-not-fat. Data for peak test-day milk yield, services per conception, and days open were obtained from Dairy Herd Improvement Association herd records. Disease occurrence was determined based on herd treatment records. Hypocalcemic cows had significantly higher nonesterified fatty acids on d 0. Hypocalcemic cows also had significantly more lipid in hepatocytes on d 7 and 35 postpartum. However, no statistically significant differences were observed between groups for plasma aspartate aminotransferase and gamma glutamyl transferase activities or total and direct bilirubin concentrations. Milk protein percentage was lower in hypocalcemic cows on d 21 and 35. However other milk quality variables (somatic cell count, milk fat percentage, and solids-not-fat) and milk yield variables (peak test-day milk yield and 305-d mature-equivalent 4% fat-corrected milk yield) did not differ between groups. No differences were observed between groups in the

  20. In vivo triglyceride synthesis in subcutaneous adipose tissue of humans correlates with plasma HDL parameters

    Science.gov (United States)

    Tuvdendorj, Demidmaa; Munoz, Alejandro O.; Ruiz-Barros, Viviana; Schwarz, Jean-Marc; Montalto, Giuseppe; Chandalia, Manisha; Sowers, Lawrence C.; Rizzo, Manfredi; Murphy, Elizabeth J; Abate, Nicola

    2016-01-01

    Backgrounds and aims Low concentrations of plasma HDL-C are associated with the development of atherosclerotic cardiovascular diseases and type 2 diabetes. Here we aimed to explore the relationship between the in vivo fractional synthesis of triglycerides (fTG) in subcutaneous (s.q.) abdominal adipose tissue (AT), HDL-C concentrations and HDL particle size composition in non-diabetic humans. Methods The fTG in s.q. abdominal AT was measured in 16 non-diabetic volunteers (7 women, 9 men; Age: 49±20 years; BMI: 31±5 kg/m; Fasting Plasma Glucose: 90±10 mg/dl) after 2H2O labeling. HDL-C concentration and subclasses, large (L-HDL), intermediate (I-HDL) and small (S-HDL) were measured. Results Linear regression analyses demonstrated significant associations of fTG with plasma concentration of HDL-C (r=0.625,p=0.009) and percent contribution of L-HDL (r=0.798,pHDL (r=−0.765,pHDL (r=−0.629, p=0.009). When analyses were performed by gender, the associations remained significant in women (HDL-C: r=0.822,p=0.023; L-HDL: r=0.892,p=0.007; I-HDL: r=−0.927,p=0.003) but not men. Conclusions Our study demonstrated an in vivo association between subcutaneous abdominal adipose tissue lipid dynamics and HDL parameters in humans, but this was true for women not men. Positive association with L-HDL and negative with I-HDL suggest that subcutaneous abdominal adipose tissue lipid dynamics may play an important role in production of mature functional HDL particles. Further studies evaluating the mechanism responsible for these associations and the observed gender differences are important and warranted to identify potential novel targets of intervention to increase the production of atheroprotective subclasses of HDL-Cs and thus decreasing the risks of development of atherosclerotic conditions. PMID:27323227

  1. The role of spatial confinement for improvement of laser-induced Mg plasma parameters and growth of surface features

    Science.gov (United States)

    Hayat, Asma; Bashir, Shazia; Rafique, Muhammad Shahid; Ahmad, Riaz; Akram, Mahreen; Mahmood, Khaliq; Zaheer, Ali

    2017-08-01

    The role of spatial confinement for improvement of laser-induced Mg plasma parameters and growth of surface features is investigated by introducing a metallic blocker. Nd: YAG laser at various fluences ranging from 7 to 28 J cm-2 was employed as an irradiation source. All measurements were performed in the presence of Ar under different pressures. Confinement effects offered by metallic blocker are investigated by placing the blocker at different distances of 6, 8 and 10 mm from the target surface. It is revealed from laser-induced breakdown spectroscopy analysis that both plasma parameters, i.e., excitation temperature and electron number density initially increase with increasing laser fluence due to enhancement in energy deposition. With further increase in laser fluence, a decreasing trend followed by saturation is observed which is attributable to shielding effect and self-regulating regime. It is also observed that spatial confinement offered by metallic blocker is responsible for the significant enhancement of both electron temperature and electron number density of Mg plasma. This is true for all laser fluences and pressures of Ar. Maximum values of electron temperature and electron number density without blocker are 8335 K and 2.4 × 1016 cm-3, respectively, whereas these values are enhanced to 12,200 K and 4 × 1016 cm-3 in the presence of the blocker. The physical mechanisms responsible for the enhancement of Mg plasma parameters are plasma compression, confinement and pronounced collisional excitations due to reflection of shock waves. Scanning electron microscope analysis was performed to explore the surface morphology of laser-ablated Mg. It reveals the formation of cones, cavities and ripples. These features become more distinct and well defined in the presence of the blocker due to plasma confinement. The optimum combination of blocker distance, fluence and Ar pressure can identify the suitable conditions for defining the role of plasma parameters

  2. Influence of the initial parameters of the magnetic field and plasma on the spatial structure of the electric current and electron density in current sheets formed in helium

    Energy Technology Data Exchange (ETDEWEB)

    Ostrovskaya, G. V., E-mail: galya-ostr@mail.ru [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Markov, V. S.; Frank, A. G., E-mail: annfrank@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation)

    2016-01-15

    The influence of the initial parameters of the magnetic field and plasma on the spatial structure of the electric current and electron density in current sheets formed in helium plasma in 2D and 3D magnetic configurations with X-type singular lines is studied by the methods of holographic interferometry and magnetic measurements. Significant differences in the structures of plasma and current sheets formed at close parameters of the initial plasma and similar configurations of the initial magnetic fields are revealed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-14

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

  4. Experimental measurements of the hollow cathode DC glow discharge parameters in Ar and He plasmas

    Science.gov (United States)

    Omrani, M.; Amrollahi, R.; Iraji, D.

    2016-12-01

    In this article, we focus on some of the fundamental parameters of SS316L hollow cathode glow discharge. Four SS316L samples are placed at different locations on the cathode surface and the current passed through them is measured in Ar and He glow discharge plasmas. The wall current densities of Ar and He are in the range of 8-25 µA cm-2 and 8-35 µA cm-2, respectively. Results also show that with decreasing working pressure, the ion flux and current density distribution on the wall surface becomes more uniform. The ion flux of the Ar and He is in the range of 1013 to 1014 ~\\text{ion} \\text{c}{{\\text{m}}-2} . Total energy losses of Ar and He are measured at the pressure range of 1.4-5.5  ×  10-2 torr and 3.2-7.1  ×  10-1, respectively. In both Ar and He, total energy losses decreased with increasing pressure. The secondary electron emission coefficients of Ar and He, which are evaluated for the hallow cathode configuration, are about 0.42 and 0.26, respectively, and are higher in comparison with the plate cathode configuration.

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

    Science.gov (United States)

    Wang, Xiaocui; Zhang, Haijun; Wang, Hao; Wang, Jing; Wu, Shugeng; Qi, Guanghai

    2017-01-01

    Objective This study was conducted to evaluate the effects of dietary protein sources (soybean meal, SBM; low-gossypol cottonseed meal, LCSM; double-zero rapeseed meal, DRM) on laying performance, egg quality, and plasma parameters of laying hens. Methods A total of 432 32-wk-old laying hens were randomly divided into 6 treatments with 6 replicates of 12 birds each. The birds were fed diets containing SBM, LCSM100, or DRM100 individually or in combination with an equal amount of crude protein (CP) (LCSM50, DRM50, and LCSM50-DRM50). The experimental diets, which were isocaloric (metabolizable energy, 11.11 MJ/kg) and isonitrogenous (CP, 16.5%), had similar digestible amino acid profile. The feeding trial lasted 12 weeks. Results The daily egg mass was decreased in the LCSM100 and LCSM50-DRM50 groups (p0.05) and showed increased yolk color at the end of the trial (p0.05). Conclusion Together, our results suggest that the LCSM100 or DRM100 diets may produce the adverse effects on laying performance and egg quality after feeding for 8 more weeks. The 100.0 g/kg LCSM diet or the148.7 g/kg DRM diet has no adverse effects on laying performance and egg quality. PMID:27608634

  6. Characteristics and plasma parameters of a short-wavelength low-pressure discharge lamp

    Science.gov (United States)

    Shuaibov, A. K.; Shevera, I. V.; Malinina, A. A.

    2008-10-01

    We have studied the working optical characteristics and electron kinetic coefficients of a short-wavelength, electric discharge exciplex-halogen UV-VUV lamp employing a mixture of argon and chlorine with a total pressure of P = 0.5 10 kPa. The lamp operates on a system of broadened electron-vibrational bands of ArCl (175 nm) and chlorine (200, 258 nm) molecules, which overlap to form a continuum in the spectral range of 160 260 nm. It is established that the optimum mixtures are those with p(Ar) - p(Cl2) = (2 4)-(0.15 0.30) kPa. The average output power of the short-wavelength radiation is 1 2 W at an efficiency of ˜5%. The electron energy distribution functions (EDFs) and the discharge plasma parameters have been calculated by solving the Boltzmann equation for a gas mixture with the experimentally determined optimum composition in the range of E/ P values from 1 to 200 V/(cm Torr), where E is the electric field strength and P is the total gas pressure. Using the obtained EDFs, the electron transport characteristics, specific discharge power losses for the main elementary processes, and rate constants of electron processes are determined.

  7. Parameter Study of Plasma-Induced Atmospheric Sputtering and Heating at Mars

    Science.gov (United States)

    Williamson, Hayley N.; Johnson, Robert E.; Leblanc, Francois

    2014-11-01

    Atoms and molecules in Mars’ upper atmosphere are lost predominately through sputtering, caused by the impact of ions into the exosphere, dissociative recombination, and thermal escape. While all three processes are thought to occur on Mars, a detailed understanding must ascertain the relative importance of each process, due to time variations in pick-up and solar wind ions. In this project, using case studies of an oxygen atmosphere modeled with Direct Simulation Monte Carlo techniques, we have endeavored to categorize when the momentum transfer or thermal escape is more likely to occur. To do this, we vary the incident plasma flux and energy based on models of the interaction of the solar wind with the Martian atmosphere. We first repeat the heating and sputtering rates due to a flux of pick-up O+ examined previously (Johnson et al. 2000; Michael and Johnson 2005; Johnson et al 2013). We have used multiple examples of particle fluxes for various solar wind conditions, from steady solar wind conditions (Luhmann et al. 1992; Chaufray et al. 2007) to more extreme cases (Fang et al. 2013; Wang et al. 2014), which are thought to increase escape by several orders of magnitude. The goal is to explore the escape parameter space in preparation for the expected data from MAVEN on hot atoms and molecules in the Martian exosphere.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    Plasma parameters in the vicinity of the dielectric window of a low density, microwave discharge produced in 0, at 915 N/FHz are investigated by a spherical probe and optical emission spectroscopy while the microwave field distribution is measured by a spectrum analyzer. The electron energy...

  9. Growth of large size diamond single crystals by plasma assisted chemical vapour deposition: Recent achievements and remaining challenges

    Science.gov (United States)

    Tallaire, Alexandre; Achard, Jocelyn; Silva, François; Brinza, Ovidiu; Gicquel, Alix

    2013-02-01

    Diamond is a material with outstanding properties making it particularly suited for high added-value applications such as optical windows, power electronics, radiation detection, quantum information, bio-sensing and many others. Tremendous progresses in its synthesis by microwave plasma assisted chemical vapour deposition have allowed obtaining single crystal optical-grade material with thicknesses of up to a few millimetres. However the requirements in terms of size, purity and crystalline quality are getting more and more difficult to achieve with respect to the forecasted applications, thus pushing the synthesis method to its scientific and technological limits. In this paper, after a short description of the operating principles of the growth technique, the challenges of increasing crystal dimensions both laterally and vertically, decreasing and controlling point and extended defects as well as modulating crystal conductivity by an efficient doping will be detailed before offering some insights into ways to overcome them.

  10. Effects of Dietary Supplementation of Some Antioxidants on Liver Antioxidant Status and Plasma Biochemistry Parameters of Heat-Stressed Quail

    Directory of Open Access Journals (Sweden)

    Senay Sarıca

    2017-07-01

    Full Text Available This study aimed to compare the dietary supplementation of oleuropein (O and α-tocopherol acetate (TA alone or with organic selenium (Se on liver antioxidant status and some plasma biochemistry parameters in Japanese quails reared under heat stress (HS. A total of 800, two-weeks old quails were kept in wire cages in the temperature-controlled rooms at either 22°C or 34°C for 8 h/d and fed on a basal diet (NC or the diets supplemented with TA (TA200 or O (O200 at 200 mg/kg alone or with OSe (TA200+OSe and O200+OSe to the NC diet. HS decreased the total antioxidant status (TAS and increased the total oxidative stress (TOS and oxidative stress index (OSI of liver compared to thermoneutral temperature (TN. The TA200, O200, TA200+OSe and O200+OSe diets increased TAS and decreased TOS of liver compared to those of quails fed NC. OSI was decreased by the TA200, O200 and TA200+OSe diets compared to NC and O200+OSe diets. HS reduced plasma albumin (A and total protein (TP concentrations, on the other hand, increased plasma glucose (G, total cholesterol (CHO and triglyceride (TG levels compared to TN. The TA200, O200, TA200+OSe and O200+OSe diets reduced plasma total CHO and TG levels and increased plasma A level. The TA200 and TA200+OSe diets reduced plasma G level and increased plasma TP levels compared to those of quails fed the other diets. In conclusion, dietary supplementation of vitamin E and oleuropein alone or with organic selenium is necessary to remove the negative effects of heat stress on liver antioxidant status and some plasma parameters of quails.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sanmartin, J. A.; Barrero, A.

    1976-07-01

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

  12. Effect of the initial plasma parameters on the structure of the current sheets developing in two-dimensional magnetic fields with a null line

    Science.gov (United States)

    Ostrovskaya, G. V.; Frank, A. G.; Bogdanov, S. Yu.

    2010-07-01

    The effect of the initial plasma parameters on the structure of the plasma of the current sheets that form in two-dimensional magnetic fields with a null line is studied by holographic interferometry. The evolution of the plasma sheets that develop in an initial low-density plasma, where a gas is mainly ionized by a pulse current passing through the plasma and initiating the formation of a current sheet, has been comprehensively studied for the first time. At the early stage of evolution, the spatial structure of such a plasma sheet differs substantially from the classic current sheets forming in a dense plasma. Nevertheless, extended plasma sheets with similar parameters form eventually irrespective of the initial plasma density.

  13. Measuring the parameters of a high flux plasma in Proto-MPEX

    Science.gov (United States)

    Skeen, C.; Biewer, T. M.; Cantrell, C. L.; Klemm, J. C.; Musick, R. A.; Nunley, G.; Salazar Sanchez, J. S.; Sawyer, D. J.; Ray, H.; Shaw, G.; Showers, M.

    2016-10-01

    The Prototype Material Plasma Exposure Experiment (Proto-MPEX) is a linear, magnetically confined plasma production device, utilizing a helicon antenna. The plasma column interacts with a material target at the end of the device, creating plasma-material interaction conditions that are relevant to the conditions that are expected in future fusion reactors. Moreover, helicon antenna plasma sources have been proposed as propulsion devices for spacecraft. It has been observed that in some circumstances the Proto-MPEX plasma exerts sufficient force on the target plate to cause the target to recoil. A ballistic probe has been designed to measure the force and heat flux profile of the plasma. The probe response has been calibrated, using scales, thermocouples, and fast camera imaging. The ballistic probe has been inserted into Proto-MPEX plasmas and the heat flux profile of the plasma has been measured. Also the maximum force that is exerted on the probe has been estimated. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725, and the Oak Ridge Associated Universities ARC program.

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

    Directory of Open Access Journals (Sweden)

    Amelia eGreig

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

  16. Influence of plasma parameters on the growth and properties of magnetron sputtered CNx thin films

    Science.gov (United States)

    Hellgren, Niklas; Macák, Karol; Broitman, Esteban; Johansson, Mats P.; Hultman, Lars; Sundgren, Jan-Eric

    2000-07-01

    Carbon nitride CNx thin films were grown by unbalanced dc magnetron sputtering from a graphite target in a pure N2 discharge, and with the substrate temperature Ts kept between 100 and 550 °C. A solenoid coil positioned in the vicinity of the substrate was used to support the magnetic field of the magnetron, so that the plasma could be increased near the substrate. By varying the coil current and gas pressure, the energy distribution and fluxes of N2+ ions and C neutrals could be varied independently of each other over a wide range. An array of Langmuir probes in the substrate position was used to monitor the radial ion flux distribution over the 75-mm-diam substrate, while the flux and energy distribution of neutrals was estimated through Monte Carlo simulations. The structure, surface roughness, and mechanical response of the films are found to be strongly dependent on the substrate temperature, and the fluxes and energies of the deposited particles. By controlling the process parameters, the film structure can thus be selected to be amorphous, graphite-like or fullerene-like. When depositing at 3 mTorr N2 pressure, with Ts>200 °C, a transition from a disordered graphite-like to a hard and elastic fullerene-like structure occurred when the ion flux was increased above ˜0.5-1.0 mA/cm2. The nitrogen-to-carbon concentration ratio in the films ranged from ˜0.1 to 0.65, depending on substrate temperature and gas pressure. The nitrogen film concentration did, however, not change when varying the nitrogen ion-to-carbon atom flux ratios from ˜1 to 20.

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

    Science.gov (United States)

    Yi, Min; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2013-01-01

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

  18. Nicotine, cotinine, and trans-3-hydroxycotinine levels in seminal plasma of smokers: effects on sperm parameters.

    Science.gov (United States)

    Pacifici, R; Altieri, I; Gandini, L; Lenzi, A; Pichini, S; Rosa, M; Zuccaro, P; Dondero, F

    1993-10-01

    Sperm samples from 44 cigarette smokers and 50 nonsmokers attending an infertility clinic were examined by high-performance liquid chromatography (HPLC) assay and HPLC-mass spectrometry for the presence of nicotine (NIC), cotinine (COT), and trans-3'-hydroxycotinine (THOC) in seminal plasma. Smokers were found to have levels of COT and THOC in seminal plasma that were similar to those found in serum. The level of NIC was significantly increased in seminal plasma compared to serum. Total motility of spermatozoa was significantly and negatively correlated to COT and THOC levels in seminal plasma. Forward motility of spermatozoa was correlated only with cotinine semen levels. On the basis of these results, we suggest that the presence of tobacco smoke constituents in seminal plasma could provide a warning of the adverse effects of cigarette smoke on the physiology of reproduction.

  19. Effect of applying static electric field on the physical parameters and dynamics of laser-induced plasma

    Directory of Open Access Journals (Sweden)

    Asmaa Elhassan

    2010-04-01

    Full Text Available In order to improve the performance of the LIBS technique – in particular its sensitivity, reproducibility and limit of detection – we studied the effect of applying a static electric field with different polarities on the emission spectra obtained in a typical LIBS set-up. The physical parameters of the laser-induced plasma, namely the electron density Ne and the plasma temperature Te, were studied under such circumstances. In addition to the spectroscopic analysis of the plasma plume emission, the laser-induced shock waves were exploited to monitor the probable changes in the plasma plume dynamics due to the application of the electric field. The study showed a pronounced enhancement in the signal-to-noise (S/N ratio of different Al, neutral and ionic lines under forward biasing voltage (negative target and positive electrode. On the other hand, a clear deterioration of the emission line intensities was observed under conditions of reversed polarity. This negative effect may be attributed to the reduction in electron-ion recombinations due to the stretched plasma plume. The plasma temperature showed a constant value in the average with the increasing electric field in both directions. This effect may be due to the fact that the measured values of Te were averaged over the whole plasma emission volume. The electron density was observed to decrease slightly in the case of forward biasing while no significant effect was noticed in the case of reversed biasing. This slight decrease in Ne can be interpreted in view of the increase in the rate of electron–ion recombinations due to the presence of the electric field. No appreciable effects of the applied electric field on the plasma dynamics were noticed.

  20. Effect of magnetic configuration on plasma parameters in the H-1 heliac

    Energy Technology Data Exchange (ETDEWEB)

    Blackwell, B.D.; Pretty, D.G.; Harris, J.H.; Howard, J.; Shats, M.G.; Collis, S.M.; Gardner, H.J.; Michael, C.A.; Punzmann, H. [Plasma Research Laboratory, Research School of Physical Sciences and Engineering Australian National University, ACT (Australia)

    2003-07-01

    The H-1 heliac is a current-free stellarator with a helical magnetic axis which twists around the machine axis (a circular ring conductor, radius 1m) three times in one toroidal rotation. It us a ''flexible'' heliac composed almost entirely of circular coils with the exception of the helical control winding, which also wraps around the ring conductor, in phase with the magnetic axis of the plasma, but with a smaller swing radius (95 mm c.f. {proportional_to} 230 mm). In addition to indicating particle confinement times, this phenomenon may be sensitive to plasma generation efficiency. There may be some interaction between configuration and impurity generation, as plasma boundaries and strike points are varied. Various plasma conditions and formation techniques are compared. (orig.)

  1. Influence of instrumental parameters on the kinetic energy of ions and plasma temperature for a hexapole collision/reaction-cell-based inductively coupled plasma quadrupole mass spectrometer.

    Science.gov (United States)

    Favre, Georges; Brennetot, René; Chartier, Frédéric; Tortajada, Jeanine

    2009-02-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in inorganic analytical chemistry for element and/or isotope ratio measurements. The presence of interferences, which is one of the main limitations of this method, has been addressed in recent years with the introduction of collision/reaction cell devices on ICP-MS apparatus. The study of ion-molecule reactions in the gas phase then became of great importance for the development of new analytical strategies. Knowing the kinetic energy and the electronic states of the ions prior to their entrance into the cell, i.e., just before they react, thereby constitutes crucial information for the interpretation of the observed reactivities. Such studies on an ICP-MS commonly used for routine analyses require the determination of the influence of different instrumental parameters on the energy of the ions and on the plasma temperature from where ions are sampled. The kinetic energy of ions prior to their entrance into the cell has been connected to the voltage applied to the hexapole according to a linear relationship determined from measurements of ion energy losses due to collisions with neutral gas molecules. The effects of the plasma forward power, sampling depth, and the addition of a torch shield to the ICP source were then examined. A decrease of the plasma potential due to the torch shielding, already mentioned in the literature, has been quantified in this study at about 3 V.

  2. An improved model to analyze Langmuir probe assisted photo-detachment signal for measuring electronegative plasma parameters

    Science.gov (United States)

    Sirse, Nishant; Oudini, Noureddine; Bendib, Abderrezeg; Ellingboe, Albert R.

    2016-09-01

    A diagnostic technique for measuring negative ion parameters based on Langmuir probe assisted laser photo-detachment relies on a theoretical model which relates the rise in the electron saturation current to electronegativity in the plasma. The existing model depend on various assumptions and neglect electrostatic potential barrier formed between the laser column (electropositive column) and the surrounding electronegative plasma in order to prevent the outward flow of electrons from the electropositive plasma column. These assumptions leads to erroneous estimation of the plasma electronegativity. In the present work, we present an analytical model to analyze Langmuir probe assisted photo-detachment signal in order to improve the accuracy of measured electronegativity and extended this technique for measuring electron temperature and charged species density. The analytical model is validated using both experiments and particle-in-cell simulation. The results shows improved accuracy in the measured parameters when compared to existing model. This work was supported by the Korea Institute for the Advancement of Technology and Ministry of Knowledge Economy (L-2010-1438-000), Republic of Korea, Enterprise Ireland and the European Regional Development Fund (ERDF) under NSRF 2007-2013.

  3. Evaluation of the operational parameters for NBI-driven fusion in low-gain tokamaks with two-component plasma

    Science.gov (United States)

    Chirkov, A. Yu.

    2015-09-01

    Low gain (Q ~ 1) fusion plasma systems are of interest for concepts of fusion-fission hybrid reactors. Operational regimes of large modern tokamaks are close to Q  ≈  1. Therefore, they can be considered as prototypes of neutron sources for fusion-fission hybrids. Powerful neutral beam injection (NBI) can support the essential population of fast particles compared with the Maxwellial population. In such two-component plasma, fusion reaction rate is higher than for Maxwellian plasma. Increased reaction rate allows the development of relatively small-size and relatively inexpensive neutron sources. Possible operating regimes of the NBI-heated tokamak neutron source are discussed. In a relatively compact device, the predictions of physics of two-component fusion plasma have some volatility that causes taking into account variations of the operational parameters. Consequent parameter ranges are studied. The feasibility of regimes with Q  ≈  1 is shown for the relatively small and low-power system. The effect of NBI fraction in total heating power is analyzed.

  4. Real time measurement of plasma macroscopic parameters on RFX-mod using a limited set of sensors

    Science.gov (United States)

    Kudlacek, Ondrej; Zanca, Paolo; Finotti, Claudio; Marchiori, Giuseppe; Cavazzana, Roberto; Marrelli, Lionello

    2015-10-01

    A method to estimate the plasma boundary and global parameters such as βp+li/2 and the edge safety factor q95 is described. The method is based on poloidal flux extrapolation in the vacuum region between the plasma and the magnetic measurements, and it is efficient and accurate even if a limited set of sensors is used. The discrepancy between the plasma boundary provided by this method and the boundary computed by the Grad-Shafranov solver MAXFEA is lower than 8 mm in all the considered cases. Moreover, the method is robust against the noise level present in the RFX-mod measurements. The difference between the estimated global parameters and the MAXFEA simulation results is lower than 4%. The method was finally implemented in the RFX-mod shape control system, working at 5 kHz cycle frequency, to provide a reliable set of plasma-wall distances (gaps) used as feedback signals. Experimental results obtained in one year of RFX-mod operation are shown.

  5. Kinetic parameters and intraindividual fluctuations of ochratoxin A plasma levels in humans

    Energy Technology Data Exchange (ETDEWEB)

    Studer-Rohr, I. [Inst. of Toxicology, Swiss Federal Inst. of Tech. and Univ. of Zurich, Schwerzenbach (Switzerland); Dept. of Food Science, Swiss Federal Inst. of Tech., Zurich (Switzerland); Schlatter, J. [Toxicology Section, Div. of Food Science, Swiss Federal Office of Public Health, Zurich (Switzerland); Dietrich, D.R. [Dept. of Environmental Toxicology, Univ. of Konstanz, Konstanz (Germany); Inst. of Toxicology, Swiss Federal Inst. of Tech. and Univ. of Zurich, Schwerzenbach (Switzerland)

    2000-11-01

    The mycotoxin ochratoxin A (OTA) is a rodent carcinogen produced by species of the ubiquitous fungal genera Aspergillus and Penicillium. OTA is found in a variety of food items and as a consequence is also found in human plasma (average concentrations found in this study: 0.1-1 ng OTA/ml plasma). To improve the scientific basis for cancer risk assessment the toxicokinetic profile of OTA was studied in one human volunteer following ingestion of 395 ng {sup 3}H-labeled OTA (3.8 {mu}Ci). A two-compartment open model consisting of a central compartment was found to best describe the in vivo data. This two-compartment model consisted of a fast elimination and distribution phase (T{sub 1/2} about 20 h) followed by a slow elimination phase (renal clearance about 0.11 ml/min.) and a calculated plasma half-life of 35.55 days. This half-life was approximately eight times longer than that determined previously in rats. In addition, the intraindividual fluctuation of OTA plasma levels was investigated in eight individuals over a period of 2 months. The concentrations determined ranged between 0.2 and 0.9 ng OTA/ml plasma. The plasma levels in some individuals remained nearly constant over time, while others varied considerably (e.g. increase of 0.4 ng/ml within 3 days, decrease of 0.3 ng/ml within 5 days) during the observation period. This intraindividual fluctuation in OTA plasma levels, which may represent differences in OTA exposure and/or metabolism, as well as the large difference in plasma half-life in humans compared to rats must be taken into consideration when the results of rat cancer study data are extrapolated to humans for risk assessment purposes. (orig.)

  6. Influence of argon fraction on plasma parameters in H2-N2 mixture discharge with cathodic cage

    Science.gov (United States)

    Naeem, Muhammad; Zaka-ul-Islam, Mujahid; Khattak, Zahid Iqbal; Shafiq, Muhammad; Zakaullah, Muhammad

    2017-01-01

    Low-pressure H2-N2 mixture pulsed DC plasmas with a cathodic cage (active screen) are widely used for plasma nitriding applications. In this study, the low-pressure H2-N2 mixture plasma with a cathodic cage generated by 50 Hz pulsed DC source is investigated with triple Langmuir probe and optical emission spectroscopy. The electron temperature (TeLP T e LP ) and electron number density (ne) are measured using a triple Langmuir probe (TLP). The excitation temperature (TexcOES T e xc OES ) is calculated spectroscopically using Boltzmann plot method whereas nitrogen dissociation fraction is estimated using actinometry as well as the intensity ratio method (IN (746.83 nm)/IN2(337.1 nm)). The results show that the electron and excitation temperatures, electron density and nitrogen atomic species density [N] all increase with the argon admixture, however, the important molecular ionized species density [N2+ N 2 + ] significantly decreases beyond 30% addition. This study provides useful information about the influence of the argon addition on plasma parameters and active species generation. As a result it helps to optimize the plasma nitriding system as a function of argon admixture to avoid random trials in the processing.

  7. Effect of q-nonextensive parameter and saturation time on electron density steepening in electron-positron-ion plasmas

    Science.gov (United States)

    Hashemzadeh, M.

    2015-11-01

    The effect of q-nonextensive parameter and saturation time on the electron density steepening in electron-positron-ion plasmas is studied by particle in cell method. Phase space diagrams show that the size of the holes, and consequently, the number of trapped particles strongly depends on the q-parameter and saturation time. Furthermore, the mechanism of the instability and exchange of energy between electron-positron and electric field is explained by the profiles of the energy density. Moreover, it is found that the q-parameter, saturation time, and electron and positron velocities affect the nonlinear evolution of the electron density which leads to the steepening of its structure. The q-nonextensive parameter or degree of nonextensivity is the relation between temperature gradient and potential energy of the system. Therefore, the deviation of q-parameter from unity indicates the degree of inhomogeneity of temperature or deviation from equilibrium. Finally, using the kinetic theory, a generalized q-dispersion relation is presented for electron-positron-ion plasma systems. It is found that the simulation results in the linear regime are in good agreement with the growth rate results obtained by the kinetic theory.

  8. Interaction of CLAM Steel with Plasma in HT-7 Tokamak During High Parameter Operation

    Institute of Scientific and Technical Information of China (English)

    LI Chunjing; HUANG Qunying; FENG Yan; LI Jiangang; KONG Mingguang

    2007-01-01

    A Plasma Surface Interaction(PSI)experiment on China Low Activation Martensitic(CLAM)steel was done to check if CLAM steel could be used as a Plasma Facing Material (PFM).A specimen with a diameter of 45 mm was exposed to 897 shots of deuterium plasmas with a total duration of 712 sec at a minor radius of 30 cm in HT-7 tokamak.During the exposure experiment,no observable influence Was found on plasma performance.After exposure,the surface of the specimen seemed as smooth as before but with some colour change at the margin of the specimen.Even though some micro-damage,such as dense blisters,melting,splashing,depositions,and dust,Was found on local surfaces with Scanning Electron Microscopic(SEM)observation.The reflectivity of the specimen decreased only slightly.All of these shows CLAM steel has good stability and irradiation resistance.With further optimization,it could possibly be used as the first mirror material for plasma diagnostics in tokamaks.

  9. Instability Parameters of Optical Oscillation Frequency in Plasma Central Discharge and Periphery Region

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhu-Wen; M.A.LIEBERMAN; Sungjin KIM

    2006-01-01

    @@ We have observed relaxation oscillations in a capacitive discharge in Ar gas, connected to a peripheral ground chamber. The plasma oscillations observed from time-varying optical emission from the main discharge chamber show, for example, a high frequency (75.37kHz) relaxation oscillation, at 100mTorr and 8 W absorbed power,and a low frequency (2.72 Hz) relaxation oscillation, 100mTorr and 325 W absorbed power. Time-varying optical emission intensity and plasma density are also detected with a Langmuir probe. The theoretical result agrees well with experiments.

  10. Characterization of Nuclease Activity in Human Seminal Plasma and its Relationship to Semen Parameters, Sperm DNA Fragmentation and Male Infertility.

    Science.gov (United States)

    Fernandez-Encinas, Alba; García-Peiró, Agustí; Ribas-Maynou, Jordi; Abad, Carlos; Amengual, María José; Navarro, Joaquima; Benet, Jordi

    2016-01-01

    Some studies have shown that complementary biomarkers are needed in semen analysis to provide a more accurate diagnosis for couples with infertility problems. To our knowledge no study has been done to determine the relationships among nuclease activity in seminal plasma, semen parameters, sperm DNA fragmentation and male infertility. A total of 94 semen samples were collected according to WHO 2010 semen analysis parameters. Samples were analyzed using the single radial enzyme diffusion method for nuclease activity in seminal plasma, and alkaline and neutral Comet assay for sperm DNA fragmentation. Samples were obtained from 11 fertile donors with proven fertility, 17 patients with normozoospermia in an infertile couple, and 16 patients with asthenozoospermia, 19 with teratozoospermia, 21 with asthenoteratozoospermia and 10 with azoospermia. Nuclease activity analyzed in seminal plasma was higher in patients than in controls. It correlated with sperm motility and morphology, and sperm DNA fragmentation measured by the alkaline Comet assay. No correlation with sperm DNA fragmentation was measured by the neutral Comet assay. ROC curves to determine male infertility revealed 0.658 sensitivity, 0.727 specificity and 0.705 cm(2) AUC for the single radial enzyme diffusion method, 0.918, 1 and 0.994 cm(2) for the alkaline Comet assay, and 0.917, 0.250 and 0.373 cm(2), respectively, for the neutral Comet assay. Nuclease activity in seminal plasma corrected by sperm count is a good variable to predict male infertility. Results indicate that it could be a useful complementary parameter for male infertility diagnosis. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    in the scrape-off layer (SOL) taking into account these fluctuations is presented. Plasma transport in the SOL along the magnetic field between two targets is calculated by a one-dimensional fluid code in order to estimate the response to transient conditions along the SOL and the attention is given...

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

    DEFF Research Database (Denmark)

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

    2002-01-01

    The angular and radial variation of the ion density and electron temperature in the plasma plume produced by laser ablation of silver at fluences of 0.8-1.3 J cm(-2) at 355 nm have been studied using a time-resolving Langmuir probe. The angular dependence of the electron temperature and the magni...

  14. Comparisons of Simulated and Observed Stormtime Magnetic Intensities and Ion Plasma Parameters in the Ring Current

    Science.gov (United States)

    Chen, M. W.; Guild, T. B.; Lemon, C.; Roeder, J. L.; Le, G.; Schulz, M.

    2009-12-01

    Recent progress in ring current and plasma sheet modeling has shown the importance of a self-consistent treatment of particle transport and magnetic and electric fields in the inner magnetosphere. Models with and without self-consistency can lead to significantly different magnitudes and spatial distributions of plasma pressure and magnetic intensity during disturbed times. In this study we compare simulated and observed stormtime magnetic intensities (GOES and Polar/MFE) and ion densities (LANL/MPA and Polar/CAMMICE) to test how well self-consistent simulations can simultaneously reproduce these quantities. We simulate the ring current and plasma sheet for conditions corresponding to the 11 August 2000 storm using the self-consistent Rice Convection Model-Equilibrium (RCM-E) [Lemon et al., JGR, 2004] with a constant magnetopause location. Using the empirical IMF-dependent model of Tsyganenko and Mukai [JGR, 2003], we specify the plasma sheet pressure and density at 10 RE as the plasma boundary location in the RCM-E. The simulated ion densities at different magnetic local times agree fairly well with those from the re-analysis model of LANL/MPA densities of O’Brien and Lemon [Space Weather, 2007]. We compare the simulated magnetic intensity with the magnetic intensity measured by magnetometers on the GOES satellites at geosynchronous altitude (6.6 RE) and on the Polar satellite. Agreement between the simulated and observed magnetic intensities tends to agree better on the nightside than on the dayside in the inner magnetosphere. In particular, the model cannot account for observed drops in the dayside magnetic intensity during decreases in the solar wind pressure. We will modify the RCM-E to include a time-varying magnetopause location to simulate compressions and expansions associated with variations in the solar wind pressure. We investigate whether this will lead to improved agreement between the simulated and model magnetic intensities.

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

    Directory of Open Access Journals (Sweden)

    Leticia Elizondo-Montemayor

    2017-01-01

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

  16. Influence of Discharge Parameters on Tuned Substrate Self-Bias in an Radio-Frequency Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    Ding Zhenfeng; Sun Jingchao; Wang Younian

    2005-01-01

    The tuned substrate self-bias in an rf inductively coupled plasma source is controlled by means of varying the impedance of an external LC network inserted between the substrate and the ground. The influencing parameters such as the substrate axial position, different coupling coils and inserted resistance are experimentally studied. To get a better understanding of the experimental results, the axial distributions of the plasma density, electron temperature and plasma potential are measured with an rf compensated Langmuir probe; the coil rf peak-to-peak voltage is measured with a high voltage probe. As in the case of changing discharge power, it is found that continuity, instability and bi-stability of the tuned substrate bias can be obtained by means of changing the substrate axial position in the plasma source or the inserted resistance. Additionally,continuity can not transit directly into bi-stability, but evolves via instability. The inductance of the coupling coil has a substantial effect on the magnitude and the property of the tuned substrate bias.

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

    Directory of Open Access Journals (Sweden)

    Osman, M.

    2011-06-01

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

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

  18. Comparison between measured scrape-off layer plasma parameters and 2D model calculations for JET X-point discharges

    Energy Technology Data Exchange (ETDEWEB)

    Loarte, A. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Chankin, A. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Clement, S. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Corrigan, G. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Harbour, P. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Horton, L. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Janeschitz, G. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Lingertat, J. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Matthews, G. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Simonini, R. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Tagle, J.A. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Taroni, A. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom); Vlases, G. [JET Joint Undertaking, Abingdon, Oxon, OX14 3EA (United Kingdom)

    1995-04-01

    Modelling with the EDGE2D/U-NIMBUS code of the measured scrape-off layer plasma parameters for JET divertor discharges is presented. Model results agree with the experiment if very small values (< or {approx}0.1 m{sup 2}/s in H-modes and low power L-modes) for the anomalous particle transport diffusion coefficient in the SOL are used. While the assumption of the power flow out of the main plasma being carried equally by the electrons and the ions describes satisfactorily the global power balance for Ohmic and L-mode discharges, more power flowing out through the ion channel is consistent with the power balance in hot ion H-modes. Some sensitivity studies of the code results on the modelling hypothesis are discussed. ((orig.)).

  19. Mechanism and operation parameters of a plasma-driven micro-particle accelerator

    Institute of Scientific and Technical Information of China (English)

    HUANG JianGuo; FENG ChunHua; HAN dianWei; LI HongWei; CAI MingHui; LI XiaoYin; ZHANG ZhenLong; CHEN ZhaoFeng; WANG Long; YANG XuanZong

    2009-01-01

    There is a large amount of micro debris ranging between millimeters and micrometers in space, which has significant influence on the reliability and life of spacecrafts through long-duration integrated im-pacts and has to be considered in designing a vehicle's suitability to the space environment. In order to simulate the micro-impacts on exposed materials, a plasma-driven micro-particle accelerator was de-veloped. The major processes, including the acceleration, compression and ejection of plasmas, were modeled. By comparing the theoretical simulations with the experimental results, the acceleration mechanism was clarified. Moreover, through a series of experiments, the optimum operation range was investigated, and the acceleration ability was primarily determined.

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

    Science.gov (United States)

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

    2012-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

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

  2. Plasma Oxytocin in Children with Autism and Its Correlations with Behavioral Parameters in Children and Parents

    OpenAIRE

    Husarova, Veronika Marcincakova; Lakatosova, Silvia; Pivovarciova, Anna; Babinska, Katarina; Bakos, Jan; Durdiakova, Jaroslava; Kubranska, Aneta; Ondrejka, Igor; Ostatnikova, Daniela

    2016-01-01

    Objective Oxytocin (OT) has been implicated to play an important role in autism spectrum disorders (ASD) etiology. We aimed to find out the differences in plasma OT levels between children with autism and healthy children, the associations of OT levels with particular autism symptoms and the associations of particular parental autistic traits with their ASD children OT levels. Methods We included 19 boys with autism and 44 healthy age-matched boys. OT levels were analyzed by ELISA method. Chi...

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

    Science.gov (United States)

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

    2016-05-01

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

  4. The effects of process parameters on yield and properties of iron nanoparticles from ferrocene in a low-pressure plasma

    Science.gov (United States)

    Panchal, V.; Lahoti, G.; Bhandarkar, U.; Neergat, M.

    2011-08-01

    The effects of process parameters on iron nanoparticle formation and properties while using ferrocene as a precursor in a low-pressure capacitively coupled plasma are investigated. The L18 array of the Taguchi method, followed by the L4 array, is used with the notional objective of increasing the yield of nanoparticles. A study of the size, shape and composition of the particles (using transmission electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, x-ray diffraction, CHON and inductively coupled plasma-atomic emission spectroscopy analysis) gives an insight into the role played by various process parameters. Pressure is the most critical parameter in increasing nanoparticle yield, whereas hydrogen flow plays a key role in determining the nanoparticle size and composition. Atomic hydrogen helps in removing amorphous carbon and reducing the nanoparticle size. RF power plays an important role in the dissociation of ferrocene thus also affecting the composition. Nanoparticles obtained using optimized conditions are a mixture of Fe3O4 and Fe2O3 with cluster size 25-40 nm in diameter that are further made up of 2-4 nm crystallites. Magnetic property measurements indicate that the nanoparticles are super-paramagnetic in nature.

  5. The effects of process parameters on yield and properties of iron nanoparticles from ferrocene in a low-pressure plasma

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, V; Neergat, M [Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India); Lahoti, G; Bhandarkar, U, E-mail: bhandarkar@iitb.ac.in [Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2011-08-31

    The effects of process parameters on iron nanoparticle formation and properties while using ferrocene as a precursor in a low-pressure capacitively coupled plasma are investigated. The L{sub 18} array of the Taguchi method, followed by the L{sub 4} array, is used with the notional objective of increasing the yield of nanoparticles. A study of the size, shape and composition of the particles (using transmission electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, x-ray diffraction, CHON and inductively coupled plasma-atomic emission spectroscopy analysis) gives an insight into the role played by various process parameters. Pressure is the most critical parameter in increasing nanoparticle yield, whereas hydrogen flow plays a key role in determining the nanoparticle size and composition. Atomic hydrogen helps in removing amorphous carbon and reducing the nanoparticle size. RF power plays an important role in the dissociation of ferrocene thus also affecting the composition. Nanoparticles obtained using optimized conditions are a mixture of Fe{sub 3}O{sub 4} and Fe{sub 2}O{sub 3} with cluster size 25-40 nm in diameter that are further made up of 2-4 nm crystallites. Magnetic property measurements indicate that the nanoparticles are super-paramagnetic in nature.

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

    Directory of Open Access Journals (Sweden)

    Samad Akbarzadeh

    2009-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Al-Marzoki JM

    2012-10-01

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

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

    Science.gov (United States)

    Das, Debajyoti; Mondal, Praloy

    2017-09-01

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

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

    Science.gov (United States)

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

    2010-09-01

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

  10. Impact of localized gas injection on ICRF coupling and SOL parameters in JET-ILW H-mode plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, E., E-mail: elerche@jet.efda.org [LPP-ERM-KMS, TEC Partner, 1000 Brussels (Belgium); CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Goniche, M. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Jacquet, P. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Van Eester, D. [LPP-ERM-KMS, TEC Partner, 1000 Brussels (Belgium); Bobkov, V. [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Colas, L. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Czarnecka, A. [IPPLM, 01-497 Warsaw (Poland); Brezinsek, S. [Forschungszentrum Jülich, Institute of Energy Research, Jülich (Germany); Brix, M. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Crombe, K. [LPP-ERM-KMS, TEC Partner, 1000 Brussels (Belgium); Graham, M. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Groth, M. [Aalto University, 02015 Espoo (Finland); Monakhov, I. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Mathurin, T. [École des Mines de Paris, 75006 Paris (France); Matthews, G. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Meneses, L. [Instituto de Plasma e Fusão Nuclear, Instituto Superior Técnico, Lisbon (Portugal); Noble, C. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Petrzilka, V. [Institute of Plasma Physics, Prague (Czech Republic); Rimini, F.; Shaw, A. [CCFE, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

    2015-08-15

    Recent JET-ILW [1,2] experiments reiterated the importance of tuning the plasma fuelling in order to optimize ion cyclotron resonance frequency (ICRF) heating in high power H-mode discharges. By fuelling the plasma from gas injection modules (GIMs) located in the mid-plane and on the top of the machine instead of adopting the more standardly used divertor GIMs, a considerable increase of the ICRF antenna coupling resistances was achieved with moderate gas injection rates (<1.5 × 10{sup 22} e/s). This effect is explained by an increase of the scrape-off-layer density in front of the antennas when mid-plane and top fuelling is used. By distributing the gas injection to optimize the coupling of all ICRF antenna arrays simultaneously, a substantial increase in the ICRF power capability and reliability was attained. Although similar core/pedestal plasma properties were observed for the different injection cases, the experiments indicate that the RF-induced impurity sources are reduced when switching from divertor to main chamber gas injection.

  11. [Association between systemic inflammation and autoimmunity parameters and plasma lipid in patients with rheumatoid arthritis].

    Science.gov (United States)

    Xue, Chao; Liu, Wen-ling; Sun, Yi-hong; Ding, Rong-jing; Hu, Da-yi

    2011-10-01

    The purpose of this study was to observe the association between inflammation status/autoimmune antibodies and plasma lipid in patients with rheumatoid arthritis (RA). A total of 402 RA patients were admitted into our hospital during January 2008 to March 2009 and 225 RA patients who met the inclusion criteria were selected to perform a full lipid profile examination including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), anti-keratin antibody (AKA), anti-perinuclear factor autoantibody (APF) and complement (C) were also evaluated. Atherogenic index of plasma (AIP) was calculate by the formula Log (TG/HDL-C). (1) There were 12.9%, 10.2% and 14.2% patients with elevated TC, LDL-C and TC respectively, patients with reduced HDL-C accounted for 43.6%. (2) C(3) was higher in elevated TC group than normal TC group (P elevated LDL-C group than in normal LDL-C group (P anti-CCP were positively correlated with LDL-C (R(2) = 0.129, P antibodies. Moreover, ESR and C(4) were predictors of increased AIP in this cohort.

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

    CERN Document Server

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

    2003-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Johanna M Walz

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

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

    Directory of Open Access Journals (Sweden)

    Meng Rao

    2015-01-01

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

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

    Science.gov (United States)

    Oreshkin, V. I.

    2013-11-01

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

  16. Plasma oxidative stress parameters in men and women with early stage Alzheimer type dementia.

    Science.gov (United States)

    Puertas, M C; Martínez-Martos, J M; Cobo, M P; Carrera, M P; Mayas, M D; Ramírez-Expósito, M J

    2012-08-01

    It is well known that oxidative stress is one of the earliest events in Alzheimer's disease pathogenesis, indicating that may play a key role in this disease. In our study, we measured the levels of oxidative stress indicators (TBARS and protein carbonyls content) and the non-enzymatic (glutathione (GSH) and oxidized glutathione (GSSG)) and enzymatic (glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD)) defense systems in the plasma of 46 patients diagnosed of ATD and 46 age-matched controls. We found decreased levels in total GSH in ATD patients, although healthy control women showed lower levels of total GSH than healthy control men. On the contrary, we found increased levels of TBARS and carbonyl groups content in ATD patients in both genders. The activity of the plasma antioxidant enzymes showed no changes for SOD activity in ATD patients, independently of the gender, although western blot analysis showed an increase in SOD-1 protein. CAT activity was also decreased in ATD patients, although this decrease is mainly due to the decrease found in men but not in women. However, western blot analysis did not show differences in CAT protein between controls and ATD patients. Finally, a decrease of GPx activity was found in ATD patients in both genders. However, as with CAT protein, western blot analysis did not show differences in GPx protein between controls and ATD patients. Our results suggest that there is a defect in the antioxidant defense system that is incapable of responding to increased free radical production, which may lead to oxidative damage and the development of the pathological alterations that characterize the neurodegenerative disorder of patients with ATD. Thus, oxidative damage could be one important aspect for the onset of ATD and oxidative stress markers could be useful to diagnose the illness in their earliest stages through both non-invasive, reliable and cost-affordable methods.

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

    Science.gov (United States)

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

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

  18. Profiles of ion beams and plasma parameters on a multi-frequencies microwaves large bore electron cyclotron resonance ion source with permanent magnets.

    Science.gov (United States)

    Kato, Yushi; Sakamoto, Naoki; Kiriyama, Ryutaro; Takenaka, Tomoya; Kurisu, Yosuke; Nozaki, Dai; Sato, Fuminobu; Iida, Toshiyuki

    2012-02-01

    In order to contribute to various applications of plasma and beams based on an electron cyclotron resonance, a new concept on magnetic field with all magnets on plasma production and confinement has been proposed with enhanced efficiency for broad and dense ion beam. The magnetic field configuration consists of a pair of comb-shaped magnet surrounding plasma chamber cylindrically. Resonance zones corresponding for 2.45 GHz and 11-13 GHz frequencies are positioned at spatially different positions. We launch simultaneously multiplex frequencies microwaves operated individually, try to control profiles of the plasma parameters and the extracted ion beams, and to measure them in detail.

  19. Influence of atmospheric plasma spray parameters on YSZ coatings obtained from micro and nano structured feedstocks; Influencia de los parametros de proyeccion por plasma atmosferico en recubrimientos de YSZ obtenidos a partir de polvos micro y nanoestructurados

    Energy Technology Data Exchange (ETDEWEB)

    Carpio, P.; Bannier, E.; Borrell, A.; Salvador, M. d.; Sanchez, E.

    2014-07-01

    In the present work, the influence of atmospheric plasma spray (APS) parameters on the deposition of two commercial YSZ feedstocks, one conventional and one non-conductor's, has been studied. First the study focused on how the variability of the different parameters affects the particle behaviour during spraying. For this purpose, a sensor which enables to measure the particle temperature and velocity inside the plasma was used. Once the spraying parameters influence was known, both powders were deposited by APS onto stainless steel substrates modifying the higher influencing parameters. These coatings have been characterised and the influence of the particle behaviour on the coating microstructure and properties has been analysed. This work concludes the spraying parameters variation affects on the particle velocity and temperature inside the plasma plume and this behaviour influences, in turn but in a different way, on the final coating characteristics when using different powders (micro- and nano structured). (Author)

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

    Science.gov (United States)

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

    2017-01-03

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

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

    Science.gov (United States)

    Schuhmann, Kai; Xu, Aimin; Schulte, Klaus-Martin; Simeonovic, Charmaine J.; Schwarz, Peter E. H.; Bornstein, Stefan R.; Shevchenko, Andrej; Graessler, Juergen

    2016-01-01

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

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

    CERN Document Server

    Auluck, S K H

    2014-01-01

    Dense Plasma Focus (DPF) is known to produce highly energetic ions, electrons and plasma environment which can be used for breeding of short-lived isotopes, plasma nanotechnology and other material processing applications. Commercial utilization of DPF in such areas would need a design tool which can be deployed in an automatic search for the best possible device configuration for a given application. The recently revisited [S K H Auluck, Physics of Plasmas 20, 112501 (2013)] Gratton-Vargas (GV) two-dimensional analytical snowplow model of plasma focus provides a numerical formula for dynamic inductance of a Mather type plasma focus fitted to thousands of automated computations, which enables construction of such design tool. This inductance formula is utilized in the present work to explore global optimization, based on first-principles optimality criteria, in a 4-dimensional parameter-subspace of the zero-resistance GV model. The optimization process is shown to reproduce the empirically observed constancy ...

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

    Directory of Open Access Journals (Sweden)

    L. Bailoni

    2010-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Wan Haslindawani W

    2010-01-01

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

  5. To Evaluate the Efficacy of Combination Antioxidant Therapy on Oxidative Stress Parameters in Seminal Plasma in the Male Infertility

    Science.gov (United States)

    Singh, Alpana; Radhakrishnan, Gita; Banerjee, B.D.

    2016-01-01

    Introduction Infertility is defined as inability to conceive after 1 year of unprotected intercourse and it affects 7% of male population and 8–10% of couples. According to estimates WHO, 13-19 million couples in India are infertile. Oxidative stress is the causative factor in 25% of infertile males. Aim To study the efficacy of antioxidant therapy on oxidative stress parameters in seminal plasma of infertile male. Materials and Methods Forty patients of male infertility were enrolled in study after two abnormal semen analyses reports at 2-3 weeks interval, of oligozoospermia and/or asthenozoospermia, as per WHO guide line 1999. First semen sample was collected at a time of enrollment of study and second semen sample was collected three months after combined antioxidant therapy. Semen samples from the infertile male (the second confirmatory sample of oligoasthenozoospermia) were taken and after liquefaction semen sample were utilized for various analyses, 0.5 ml of sample for standard semen analysis, 1.2 ml sample for separation of seminal plasma to evaluate Oxidative stress (OS) parameters like Malondialdehyde (MDA), Protein Carbonyl (PC) and antioxidant capacity by Glutathione (GSH). We followed the patient for three months after completion of the treatment. Results Semen parameters – Out of 40 patients recruited in the study group 7 patients had only oligospermia (1 to 20 million/ml) and 31 patients had oligoasthenozoospermia (motility range 0-50%) and 2 patients had oligoasthenoteratozoospermia. There was no patient with asthenospermia alone as abnormal semen parameters. After the three months treatment with combined antioxidants the semen parameters like count (mean SD = -1.70±1.44) and motility (mean +SD= -9.56±9.05) were significantly increased (p-value=0.000). Oxidative Stress Assessment – The level of MDA which is a marker of oxidative stress was significantly lower after the three months therapy of antioxidants (p-value=0.002) whereas another

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

    Science.gov (United States)

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

    2013-11-01

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

  7. Effects of the electrical parameters and gas flow rate on the generation of reactive species in liquids exposed to atmospheric pressure plasma jets

    Science.gov (United States)

    Baek, Eun Jeong; Joh, Hea Min; Kim, Sun Ja; Chung, T. H.

    2016-07-01

    In this work, an atmospheric pressure plasma jet was fabricated and studied for plasma-liquid interactions. The plasma jet consists of a quartz-covered pin electrode and outer quartz tube with a tapered nozzle. Using the current-voltage (I-V) and optical emission characteristics of the plasma jet, the plasma density and the speed of the plume were investigated. The optical emission spectra clearly indicated the excited NO, O, OH, N2, and N2+ in the plasma plumes. Then the plasma jets were applied to the deionized water. We investigated the effects of the operating parameters such as applied voltage, pulse frequency, and gas flow rate on the generation of reactive species in the gas and liquid phases. The densities of reactive species including OH radicals were obtained at the plasma-liquid surface and inside the plasma-treated liquids using ultraviolet absorption spectroscopy and chemical probe method. The nitrite concentration was detected by Griess assay. The data are very suggestive that there is a strong correlation among the production of reactive oxygen and nitrogen species (RONS) in the plasmas and liquids.

  8. Effects of oral powder electrolyte administration on packed cell volume, plasma chemistry parameters, and incidence of colic in horses participating in a 6-day 162-km trail ride.

    Science.gov (United States)

    Walker, Wade T; Callan, Robert J; Hill, Ashley E; Tisher, Kelly B

    2014-08-01

    This study evaluated the effects of administering oral powder electrolytes on packed cell volume (PCV), plasma chemistry parameters, and incidence of colic in horses participating on a 6-day 162-km trail ride in which water was not offered ad libitum. Twenty-three horses received grain with powder electrolytes daily while 19 control horses received grain only. Horses were ridden approximately 32 km a day at a walk or trot. Packed cell volume and plasma chemistry parameters were analyzed daily. Episodes of colic were diagnosed and treated by a veterinarian unaware of treatment group allocation. Blood parameters and incidence of colic were compared between treatment groups. Electrolyte administration did not alter PCV or plasma chemistry parameters compared to controls. The incidence of colic was significantly higher in treated horses (P = 0.05). Oral powder electrolytes did not enhance hydration status or electrolyte homeostasis and may be associated with colic in horses participating on long distance trail rides similar to this model.

  9. Optimization of nitrogen plasma source parameters by measurements of emitted light intensity for growth of GaN by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Klosek, K.; Sobanska, M.; Tchutchulashvili, G.; Zytkiewicz, Z.R., E-mail: zytkie@ifpan.edu.pl; Teisseyre, H.; Klopotowski, L.

    2013-05-01

    A comprehensive analysis of operating parameters of Addon RF nitrogen plasma source was made in order to determine how a ratio of different active nitrogen species depends on operating parameters of the source such as supplied power and nitrogen flow. We show that output signal of the optical sensor that measures intensity of the light emitted by the plasma is a direct measure of the amount of active nitrogen available for growth. Results of optical emission spectroscopy and measurements of growth kinetics show that nitrogen excited metastable molecules are the species mainly contributing to the growth of GaN under Ga-rich conditions. A procedure is presented allowing to find an optimal conditions of the plasma cell for high-quality GaN growth. Under these conditions the nitrogen flux contains maximum amount of excited metastable molecules and minimal amount of ionic and atomic nitrogen species to minimize GaN lattice damage, even at high growth rates. - Highlights: ► Operating parameters of Addon radio-frequency nitrogen plasma source studied ► Their influence on molecular beam epitaxy (MBE) growth of GaN analyzed ► MBE growth rate of GaN well correlates with output of the plasma emission sensor. ► Optical emission spectroscopy measurements of the nitrogen plasma made ► Nitrogen excited molecules mainly contribute to plasma-assisted MBE growth of GaN.

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

    Directory of Open Access Journals (Sweden)

    Partha Saikia

    2016-04-01

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

  11. Chemical compositions and plasma parameters of planetary nebulae with Wolf-Rayet and wels type central stars

    CERN Document Server

    Girard, P; Acker, A

    2006-01-01

    Aims: Chemical compositions and other properties of planetary nebulae around central stars of spectral types [WC], [WO], and wels are compared with those of `normal' central stars, in order to clarify the evolutionary status of each type and their interrelation. Methods: We use plasma diagnostics to derive from optical spectra the plasma parameters and chemical compositions of 48 planetary nebulae. We also reanalyze the published spectra of a sample of 167 non-WR PN. The results as well as the observational data are compared in detail with those from other studies of the objects in common. Results: The central star's spectral type is clearly correlated with electron density, temperature and excitation class of the nebula, [WC] nebulae tend to be smaller than the other types. All this corroborates the view of an evolutionary sequence from cool [WC 11] central stars inside dense, low excitation nebulae towards hot [WO 1] stars with low density, high excitation nebulae. The wels PN, however, appear to be a separ...

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

    Science.gov (United States)

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

    2017-07-01

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

  13. The influence of active screen plasma nitriding parameters on corrosion behavior of a low-alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Ahangarani, Sh., E-mail: ahangarani@irost.i [Department of Advanced Materials and Renewable Energies, Iranian Research Organization for Science and Technology (IROST), P.O. Box 15815-3538, Tehran (Iran, Islamic Republic of); Sabour, A.R. [Department of Materials Engineering, Tarbiat Modarres University, Tehran (Iran, Islamic Republic of); Mahboubi, F. [Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shahrabi, T. [Department of Materials Engineering, Tarbiat Modarres University, Tehran (Iran, Islamic Republic of)

    2009-09-18

    This work presents a comparative study of low-alloy steel nitriding for different possible techniques. Active screen plasma nitriding (ASPN) is a successful surface modification method that has many advantages over the conventional DC plasma nitriding (CPN). The corrosion behavior of 30CrNiMo8 low-alloy steel has been examined using anodic polarization tests in 3.5% NaCl solution under varying conditions of ASPN and CPN processes. The process variables included active screen setup parameters, treatment temperature (550 and 580 deg. C), gas mixture (25/75 and 75/25 of N{sub 2}/H{sub 2}) and treatment time (5 and 10 h) in 500 Pa pressure. The structure and phases composition of the compound layer was studied by X-ray diffraction (XRD), microhardness tests, optical microscopy and scanning electron microscopy (SEM). It was observed that ASPN treated samples surface enhanced corrosion resistance while the temperature and/or hole size of screen setup increased.

  14. Princeton Plasma Physics Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

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

  15. TIME EVOLUTION OF PLASMA PARAMETERS DURING THE RISE OF A SOLAR PROMINENCE INSTABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Orozco Suárez, D.; Asensio Ramos, A.; Trujillo Bueno, J. [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Díaz, A. J., E-mail: dorozco@iac.es [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)

    2014-04-10

    We present high-spatial resolution spectropolarimetric observations of a quiescent hedgerow prominence taken in the He I 1083.0 nm triplet. The observation consisted of a time series in sit-and-stare mode of ∼36 minutes duration. The spectrograph's slit crossed the prominence body and we recorded the time evolution of individual vertical threads. Eventually, we observed the development of a dark Rayleigh-Taylor plume that propagated upward with a velocity, projected onto the plane of the sky, of 17 km s{sup –1}. Interestingly, the plume apex collided with the prominence threads pushing them aside. We inferred Doppler shifts, Doppler widths, and magnetic field strength variations by interpreting the He I Stokes profiles with the HAZEL code. The Doppler shifts show that clusters of threads move coherently while individual threads have oscillatory patterns. Regarding the plume we found strong redshifts (∼9-12 km s{sup –1}) and large Doppler widths (∼10 km s{sup –1}) at the plume apex when it passed through the prominence body and before it disintegrated. We associate the redshifts with perspective effects while the Doppler widths are more likely due to an increase in the local temperature. No local variations of the magnetic field strength associated with the passage of the plume were found; this leads us to conclude that the plumes are no more magnetized than the surroundings. Finally, we found that some of the threads' oscillations are locally damped, what allowed us to apply prominence seismology techniques to infer additional prominence physical parameters.

  16. Plasma oxidation for achieving supported TiO2 photocatalysts derived from adsorbed TiCl4 using dielectric barrier discharge

    Science.gov (United States)

    Zhang, Xiu-Ling; Nie, Long-Hui; Xu, Yong; Shi, Chuan; Yang, Xue-Feng; Zhu, Ai-Min

    2007-03-01

    At atmospheric pressure and room temperature, dielectric barrier discharge induced plasma oxidation for achieving supported TiO2 photocatalysts derived from TiCl4 adsorbed onto γ-Al2O3 pellets was studied. The supported TiO2/γ-Al2O3photocatalysts prepared by a cyclic 'adsorption-discharge' approach, without requirement of heat treatment, exhibit high activity in the photocatalytic degradation reaction of formaldehyde. The mass spectra and optical emission spectra during O2/Ar discharge for oxidizing the adsorbed-state TiCl4 were measured. The mechanism for the TiO2 formation from adsorbed-state TiCl4 by plasma oxidation was discussed.

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

    Directory of Open Access Journals (Sweden)

    Salimi

    2016-05-01

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

  18. Influence of plasma parameters and substrate temperature on the structural and optical properties of CdTe thin films deposited on glass by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Quiñones-Galván, J. G.; Santana-Aranda, M. A.; Pérez-Centeno, A. [Departamento de Física, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, Guadalajara, Jalisco C.P. 44430 (Mexico); Camps, Enrique [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, D.F., C.P. 11801 (Mexico); Campos-González, E.; Guillén-Cervantes, A.; Santoyo-Salazar, J.; Zelaya-Angel, O. [Departamento de Física, CINVESTAV-IPN, Apartado Postal 14-740, D. F. C.P. 07360 (Mexico); Hernández-Hernández, A. [Escuela Superior de Apan, Universidad Autónoma del Estado de Hidalgo, Calle Ejido de Chimalpa Tlalayote s/n Colonia Chimalpa, Apan Hidalgo (Mexico); Moure-Flores, F. de [Facultad de Química, Materiales, Universidad Autónoma de Querétaro, Querétaro C.P. 76010 (Mexico)

    2015-09-28

    In the pulsed laser deposition of thin films, plasma parameters such as energy and density of ions play an important role in the properties of materials. In the present work, cadmium telluride thin films were obtained by laser ablation of a stoichiometric CdTe target in vacuum, using two different values for: substrate temperature (RT and 200 °C) and plasma energy (120 and 200 eV). Structural characterization revealed that the crystalline phase can be changed by controlling both plasma energy and substrate temperature; which affects the corresponding band gap energy. All the thin films showed smooth surfaces and a Te rich composition.

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

    Science.gov (United States)

    Auluck, S. K. H.

    2014-12-01

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

  20. Semen parameters and seminal plasma protein and biochemical profiles of dogs with benign prostatic hyperplasia after botulinum toxin type A intraprostatic injection

    Directory of Open Access Journals (Sweden)

    Tathiana Ferguson Motheo

    2014-06-01

    Full Text Available This study aimed to determine the effects of different concentrations of botulinum toxin type A (BT-A on semen parameters, and seminal plasma biochemical and protein profiles of dogs with benign prostatic hyperplasia (BPH. Eighteen sexually intact male dogs with BPH were randomly divided in three groups, and received an intraprostatic injection of saline solution (control group - CG, 250UI (GI or 500UI (GII of BT-A under transabdominal ultrasound guidance. Semen was collected at baseline, 2, 4 and 8 weeks after treatment. Semen parameters were determined and seminal plasma pH, total protein (TP, total chlorides (TC, calcium (Ca, potassium (K, and sodium (Na concentrations were assessed. One-dimensional sodium dodecyl sulfatepolyacrilamide gel eletrophoresis (SDS- PAGE was performed to determine seminal plasma protein profile. Sperm parameters and seminal plasma pH, TP, TC, Ca and K mean values did not change significantly at any time point and among treated groups (P>0.05. The SDS-PAGE analysis of the pooled fractions identified 31 protein bands with molecular weights ranging from 3.9 to 106.2kDA in all treatment groups during the entire evaluation period. Regardless the used dose, intraprostatic BT-A injection do not alter semen parameters and seminal plasma biochemical and protein profiles of dogs with BPH.

  1. Relevance of the choice of spark plasma sintering parameters in obtaining a suitable microstructure for iodine-bearing apatite designed for the conditioning of I-129

    Energy Technology Data Exchange (ETDEWEB)

    Campayo, L., E-mail: lionel.campayo@cea.fr [CEA, DEN, DTCD/SECM/LDMC – Marcoule, F-30207 Bagnols-sur-Cèze (France); Le Gallet, S. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-UB, 9 Av. Alain Savary, BP 47870, 21078 Dijon Cedex (France); Perret, D.; Courtois, E. [CEA, DEN, DTCD/SECM/LDMC – Marcoule, F-30207 Bagnols-sur-Cèze (France); Cau Dit Coumes, C. [CEA, DEN, DTCD/SPDE/LP2C – Marcoule, F-30207 Bagnols-sur-Cèze (France); Grin, Yu. [Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden (Germany); Bernard, F. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-UB, 9 Av. Alain Savary, BP 47870, 21078 Dijon Cedex (France)

    2015-02-15

    Highlights: • Modeling of reactive sintering by SPS of an iodoapatite for waste immobilization. • Use of a statistical approach to surmount the complexity of the process. • The supposed most resistant microstructure towards leaching is obtained at 450 °C. • Pressure has no influence in the liquid sintering regime. - Abstract: The high chemical durability of iodine-bearing apatite phases makes them potentially attractive for immobilizing radioactive iodine. Reactive spark plasma sintering provides a dense ceramic as a wasteform. A design-of-experiments (DOE) approach was adopted to identify the main process/material parameters and their first order interactions in order to specify experimental conditions guaranteeing complete reaction, relative density of the wasteform exceeding 92% and the largest possible grain size. For a disposal of the wasteform in a deep geological repository, these characteristics allow minimization of the iodine release by contact with groundwater. It was found that sintering at a temperature of 450 °C with an initial specific surface area of 3.3 m{sup 2} g{sup −1} for the powder reactants is sufficient in itself to achieve the targeted characteristics of the wasteform. However, this relies on a liquid sintering regime the efficiency of which can be limited by the lead iodide initial content in the mix as well as by its particle size.

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

    Directory of Open Access Journals (Sweden)

    Fazeli

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Juliana Castro Monteiro

    2009-04-01

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

  4. In vivo triglyceride synthesis in subcutaneous adipose tissue of humans correlates with plasma HDL parameters.

    Science.gov (United States)

    Tuvdendorj, Demidmaa; Munoz, Alejandro O; Ruiz-Barros, Viviana; Schwarz, Jean-Marc; Montalto, Giuseppe; Chandalia, Manisha; Sowers, Lawrence C; Rizzo, Manfredi; Murphy, Elizabeth J; Abate, Nicola

    2016-08-01

    Low concentrations of plasma HDL-C are associated with the development of atherosclerotic cardiovascular diseases and type 2 diabetes. Here we aimed to explore the relationship between the in vivo fractional synthesis of triglycerides (fTG) in subcutaneous (s.q.) abdominal adipose tissue (AT), HDL-C concentrations and HDL particle size composition in non-diabetic humans. The fTG in s.q. abdominal AT was measured in 16 non-diabetic volunteers (7 women, 9 men; Age: 49 ± 20 years; BMI: 31 ± 5 kg/m; Fasting Plasma Glucose: 90 ± 10 mg/dl) after (2)H2O labeling. HDL-C concentration and subclasses, large (L-HDL), intermediate (I-HDL) and small (S-HDL) were measured. Linear regression analyses demonstrated significant associations of fTG with plasma concentration of HDL-C (r = 0.625,p = 0.009) and percent contribution of L-HDL (r = 0.798,p HDL (r = -0.765,p HDL (r = -0.629, p = 0.009). When analyses were performed by gender, the associations remained significant in women (HDL-C: r = 0.822,p = 0.023; L-HDL: r = 0.892,p = 0.007; I-HDL: r = -0.927,p = 0.003) but not men. Our study demonstrated an in vivo association between subcutaneous abdominal adipose tissue lipid dynamics and HDL parameters in humans, but this was true for women not men. Positive association with L-HDL and negative with I-HDL suggest that subcutaneous abdominal adipose tissue lipid dynamics may play an important role in production of mature functional HDL particles. Further studies evaluating the mechanism responsible for these associations and the observed gender differences are important and warranted to identify potential novel targets of intervention to increase the production of atheroprotective subclasses of HDL-Cs and thus decreasing the risks of development of atherosclerotic conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  5. Blood serum and seminal plasma selenium, total antioxidant capacity and coenzyme q10 levels in relation to semen parameters in men with idiopathic infertility.

    Science.gov (United States)

    Eroglu, Mustafa; Sahin, Sadik; Durukan, Birol; Ozakpinar, Ozlem Bingol; Erdinc, Nese; Turkgeldi, Lale; Sofuoglu, Kenan; Karateke, Ates

    2014-06-01

    In this case-control study, we aimed to evaluate the serum and seminal plasma levels of Selenium (Se), total antioxidant capacity (TAC), and Coenzyme Q10 (CoQ-10) and determine their relationship with sperm concentration, motility, and morphology in men with idiopathic infertility. A total of 59 subjects were enrolled in the study. Forty four patients were diagnosed with idiopathic male infertility and had abnormal sperm parameters, and 15 subjects had normal sperm parameters with proven fertility. Serum Se, semen Se, and semen TAC levels were significantly different in the fertile and infertile groups (pspermatozoa concentration, motility, and morphology. Additionally, seminal plasma levels of TAC correlated positively with all these sperm parameters. On the other hand, seminal plasma levels of CoQ-10 correlated only with sperm morphology but not with concentration or motility. No relationship was observed between serum levels of TAC or serum levels of CoQ-10 and sperm parameters. In conclusion, serum and seminal plasma Se deficiency may be a prominent determinant of abnormal sperm parameters and idiopathic male infertility. Measurement of serum Se levels may help determine nutritional status and antioxidant capacity in infertile patients, which may help distinguish those patients who will benefit from supplementation therapy.

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

    Science.gov (United States)

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

    2012-05-01

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

  7. Effect of technique parameters on characteristics of hydrogen-free DLC films deposited by surface wave-sustained plasma

    Science.gov (United States)

    Xu, Junqi; Kousaka, Hiroyuki; Umehara, Noritsugu; Diao, Dongfeng

    2006-01-01

    Hydrogen-free diamond-like carbon (DLC) films were deposited by a new-type surface wave-sustained plasma physical vapor deposition (SWP-PVD) system under various technique conditions. Electron density was measured by a Langmuir probe, while the film thickness and hardness were characterized using a surface profilometer and a nanoindenter, respectively. Surface morphology was investigated by an atomic force microscope (AFM). It was found that the electron density and deposition rate increased following the increase in microwave power, target voltage, or gas pressure. The typical electron density and deposition rate were about 1.87-2.04×10 11 cm -3 and 1.61-14.32 nm/min respectively. AFM images indicated that the grains of films changes as the technique parameters vary. The optical constants, refractive index n and extinction coefficient k, were obtained using an optical ellipsometry. With the increase in microwave power from 150 to 270 W, the extinction coefficient of DLC films increased from 0.05 to 0.27 while the refractive index decreased from 2.31 to 2.18.

  8. Jet quenching parameter of quark-gluon plasma in strong magnetic field: perturbative QCD and AdS/CFT correspondence

    CERN Document Server

    Li, Shiyong; Yee, Ho-Ung

    2016-01-01

    We compute the jet quenching parameter $\\hat q$ of QCD plasma in the presence of strong magnetic field in both weakly and strongly coupled regimes. In weakly coupled regime, we compute $\\hat q$ in perturbative QCD at complete leading order (that is, leading log as well as the constant under the log) in QCD coupling constant $\\alpha_s$, assuming the hierarchy of scales $\\alpha_s eB\\ll T^2\\ll eB$. We consider two cases of jet orientations with respect to the magnetic field: 1) the case of jet moving parallel to the magnetic field, 2) the case jet moving perpendicular to the magnetic field. In the former case, we find $\\hat q\\sim \\alpha_s^2 (eB)T\\log(1/\\alpha_s)$, while in the latter we have $\\hat q\\sim \\alpha_s^2 (eB)T\\log(T^2/\\alpha_seB)$. In both cases, this leading order result arises from the scatterings with thermally populated lowest Landau level quarks. In strongly coupled regime described by AdS/CFT correspondence, we find $\\hat q\\sim \\sqrt{\\lambda}(eB)T$ or $\\hat q\\sim\\sqrt{\\lambda}\\sqrt{eB}T^2$ in the...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-15

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

  10. Effect of deposition parameters on structural and mechanical properties of niobium nitride synthesized by plasma focus device

    Science.gov (United States)

    Siddiqui, Jamil; Hussain, Tousif; Ahmad, Riaz; Khalid, Nida

    2015-06-01

    Effects of deposition angle and axial distance on the structural and mechanical properties of niobium nitride synthesized by a dense plasma focus (DPF) system are studied. The x-ray diffraction (XRD) confirms that the deposition parameters affect the growth of multi-phase niobium nitride. Scanning electron microscopy (SEM) shows the granular surface morphology with strong thermally assisted coagulation effects observed at the 5-cm axial distance. The non-porous granular morphology observed at the 9-cm distance along the anode axis is different from those observed at deposition angles of 10° and 20°. Energy dispersive x-ray (EDX) spectroscopy reveals the maximum nitrogen content at the shortest (5 cm) axial position. Atomic force microscopy (AFM) exhibits that the roughness of coated films varies for coatings synthesized at different axial and angular positions, and the Vickers micro-hardness test shows that a maximum hardness value is (08.44 ± 0.01) GPa for niobium nitride synthesized at 5-cm axial distance, which is about 500% more than that of a virgin sample. Project supported by the HEC, Pakistan.

  11. The Effect of Processing Parameters on the Performance of Spark Plasma Sintered cBN-WC-Co Composites

    Science.gov (United States)

    Mao, Cong; Zhang, Mingjun; Zhang, Jian; Tang, Kun; Gan, Hangyu; Zhang, Gaofeng

    2015-12-01

    Cubic boron nitride (cBN) particles were mixed into superfine tungsten carbide (WC), and then cBN-WC-cobalt (Co) composites were prepared using spark plasma sintering method. The influence of the processing parameters on the microstructures and the mechanical properties of the cBN-WC-Co composites were investigated. The results indicated that the cBN particles arranged uniformly and had an excellent adhesion with WC matrix. There was no evidence of phase transformation from cBN to hBN. With the increasing of the sintering temperature, the liquid-phase Co was increased and entered the micro-pores between WC and cBN particles easily. Correspondingly, the density, the flexural strength, and the hardness of the cBN-WC-Co composites also increased. With the further increasing of the sintering temperature, WC grains grew leading to the reduction of the hardness. Therefore, the hardness of the samples increased to a maximum value of 2978 HV at 1250 °C, and then decreased with the sintering temperature. The experimental results also showed that the density, the flexural strength, and the hardness of cBN-WC-Co composites increased with the holding time, whereas the hardness presented a decreasing tendency when the holding time exceeded 7 min.

  12. Exact relativistic kinetic theory of an electron beam-plasma system: hierarchy of the competing modes in the system parameter space

    CERN Document Server

    Bret, A; Benisti, D; Lefebvre, E

    2008-01-01

    Besides being one of the most fundamental basic issues of plasma physics, the stability analysis of an electron beam-plasma system is of critical relevance in many areas of physics. Surprisingly, decades of extensive investigation had not yet resulted in a realistic unified picture of the multidimensional unstable spectrum within a fully relativistic and kinetic framework. All attempts made so far in this direction were indeed restricted to simplistic distribution functions and/or did not aim at a complete mapping of the beam-plasma parameter space. The present paper comprehensively tackles this problem by implementing an exact linear model. We show that three kinds of modes compete in the linear phase, which can be classified according to the direction of their wavenumber with respect to the beam. We then determine their respective domain of preponderance in a three-dimensional parameter space. All these results are supported by multidimensional particle-in-cell simulations.

  13. Ion dynamics in plasma compensation scheme

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, I.V.; Lotov, K.V. E-mail: lotov@inp.nsk.su

    2002-06-11

    In this paper the ability of a plasma to compensate beam-induced fields at the interaction point of muon colliders is discussed. Among numerous factors that limit beam and plasma parameters for which a given compensation degree can be achieved, one of the most important limitations (the motion of plasma ions) is analyzed in details. It is found that this limitation is determined by an instability of the relative motion of plasma electrons and ions. It is shown that discussed parameters of ultimate muon colliders fall outside the applicability area of plasma compensation.

  14. Clinical, hematological, total plasma protein and fibrinogen parameters of magellanic penguins ( Spheniscus magellanicus pre- and post-rehabilitation

    Directory of Open Access Journals (Sweden)

    Angela M. Coraiola

    2014-12-01

    Full Text Available Abstract: Magellanic penguins (Spheniscus magellanicus usually arrive in poor body conditions at Brazilian beaches during the winter. Hematology provides valuable information about clinical and immunity status of the animals. The aims of this study were to determine the hematologic, total plasma protein (TPP and fibrinogen profiles of young and adult magellanic penguins in PROAMAR and CETAS-SC, relating these results with the state of health and survival possibility of the animals. In Paraná 14 animals were evaluated in pre and eight in post-rehabilitation and 29 animals were evaluated in Santa Catarina after rehabilitation. Before rehabilitation, all animals showed weakness. In hematological exams of these animals, we found that anemia was present in 83% of the penguins that died and 50% of those which survived. The heterophils/lymphocytes (H/L ratio was 3.87±0.57 in animals that died, significantly higher than the average of 2.20±0.30 for animals that survived. These two parameters are useful to assess the survival possibility of animals to rehabilitation. The body condition score was positively correlated with hematocrit and TPP, and negatively correlated with H/L ratio. After rehabilitation, the values were similar to other animals of the family Spheniscidae, with averages ranging from 1.64 to 1.90x106 erythrocytes/μL; 43.38 to 48.80% of hematocrit; 12.45 to 13.52g/dL of hemoglobin; 8,684 to 14,011 leukocytes/μL; 4,767 to 8,041 heterophils/μL; 3,215 to 4,951 lymphocytes/μL; 95 to 655 eosinophils/μl; 179.8 to 277.9 monocytes/μL; 141 to 184.9 basophils/μL; and 1.26 to 1.74 of H/L ratio. These parameters can therefore be used as reference values and release parameters for young and adult Magellanic penguins in captivity on the rehabilitation centers.

  15. Sublethal Effects of Paraquat on Some Plasma Organic Constituents (Metabolic Parameters of African Catfish: Clarias gariepinus (Osteichthys-Clariidae

    Directory of Open Access Journals (Sweden)

    Okenabirhie Jennifer

    2007-01-01

    Full Text Available The plasma levels of glucose, protein, cholesterol and triglyceride were determined in Clarias gariepinus exposed to sublethal concentrations of paraquat (0.30 and 0.15 mg L-1. There were significant decrease (p<0.05 in plasma glucose (showing hypoglycemia situation, plasma protein and triglyceride with a significant increase (p<0.050 in plasma cholesterol when compared with the control. These changes were directly proportional to the toxicant concentration and the exposure periods thus it is dose dependent and time-dependent.

  16. Effect of high-power laser divergence on the plasma structural parameters during multiple filamentation in air

    Science.gov (United States)

    Geints, Yu. E.; Zemlyanov, A. A.

    2016-06-01

    Multiple filamentation of an infrared high-power laser pulse in air is considered. Based on the numerical solution to the unidirectional pulse propagation equation, the effect of radiation external focusing on the spatial structure of the plasma area produced in the filamentation region is studied. We show that the number of generated plasma channels in the beam wake and the density of their spatial distribution over the filamentation region depend on the initial divergence of laser radiation. We found that in a specific range of beam focusing the number of produced plasma channels could be minimized due to the formation of a consolidated thick plasma bunch at the beam axis.

  17. Plasma diagnosis as a tool for the determination of the parameters of electron beam evaporation and sources of ionization

    Science.gov (United States)

    Mukherjee, Jaya; Dileep Kumar, V.; Yadav, S. P.; Barnwal, Tripti A.; Dikshit, Biswaranjan

    2016-07-01

    The atomic vapor generated by electron beam heating is partially ionized due to atom-atom collisions (Saha ionization) and electron impact ionization, which depend upon the source temperature and area of evaporation as compared to the area of electron beam bombardment on the target. When electron beam evaporation is carried out by inserting the target inside an insulating liner to reduce conductive heat loss, it is expected that the area of evaporation becomes significantly more than the area of electron beam bombardment on the target, resulting in reduced electron impact ionization. To assess this effect and to quantify the parameters of evaporation, such as temperature and area of evaporation, we have carried out experiments using zirconium, tin and aluminum as a target. By measuring the ion content using a Langmuir probe, in addition to measuring the atomic vapor flux at a specific height, and by combining the experimental data with theoretical expressions, we have established a method for simultaneously inferring the source temperature, evaporation area and ion fraction. This assumes significance because the temperature cannot be reliably measured by an optical pyrometer due to the wavelength dependent source emissivity and reflectivity of thin film mirrors. In addition, it also cannot be inferred from only the atomic flux data at a certain height as the area of evaporation is unknown (it can be much more than the area of electron bombardment, especially when the target is placed in a liner). Finally, the reason for the lower observed electron temperatures of the plasma for all the three cases is found to be the energy loss due to electron impact excitation of the atomic vapor during its expansion from the source.

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

    Directory of Open Access Journals (Sweden)

    D. Hubert

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

  19. Study of the interrelation between the electrotechnical parameters of the plasma focus discharge circuit and the plasma compression dynamics on the PF-3 and PF-1000 facilities

    Energy Technology Data Exchange (ETDEWEB)

    Mitrofanov, K. N., E-mail: mitrkn@inbox.ru [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Krauz, V. I., E-mail: krauz-vi@nrcki.ru, E-mail: vkrauz@yandex.ru [National Research Centre Kurchatov Institute (Russian Federation); Grabovski, E. V. [Troitsk Institute for Innovation and Fusion Research (Russian Federation); Myalton, V. V.; Vinogradov, V. P. [National Research Centre Kurchatov Institute (Russian Federation); Paduch, M. [Institute of Plasma Physics and Laser Microfusion (Poland); Scholz, M. [Polish Academy of Sciences, Niewodniczański Institute of Nuclear Physics (Poland); Karpiński, L. [Łukasiewicz University of Technology, Faculty of Electrical and Computer Engineering (Poland)

    2015-05-15

    The main stages of the plasma current sheath (PCS) dynamics on two plasma focus (PF) facilities with different geometries of the electrode system, PF-3 (Filippov type) and PF-1000 (Mather type), were studied by analyzing the results of the current and voltage measurements. Some dynamic characteristics, such as the PCS velocity in the acceleration phase in the Mather-type facility (PF-1000), the moment at which the PCS reaches the anode end, and the plasma velocity in the radial stage of plasma compression in the PF-3 Filippov-type facility, were determined from the time dependence of the inductance of the discharge circuit with a dynamic plasma load. The energy characteristics of the discharge circuit of the compressing PCS were studied for different working gases (deuterium, argon, and neon) at initial pressures of 1.5–3 Torr in discharges with energies of 0.3–0.6 MJ. In experiments with deuterium, correlation between the neutron yield and the electromagnetic energy deposited directly in the compressed PCS was investigated.

  20. Measurement of performance parameters of plasma source for plasma opening switch on Qiangguang-Ⅰ generator%强光一号POS等离子体源性能参数测量

    Institute of Scientific and Technical Information of China (English)

    罗维熙; 曾正中; 雷天时; 王亮平; 呼义翔; 孙铁平; 黄涛

    2012-01-01

    以强光一号等离子体源(电缆枪)为研究对象,采用电荷收集器(法拉第杯)对强光一号等离子体源性能参数进行测量.实验结果表明:等离子体发射密度与电缆等离子体枪枪芯到枪口的距离正相关,而发射速度与电缆等离子体枪枪芯到枪口的距离负相关;增大电缆枪驱动电压时,等离子体发射密度增速远小于驱动电流增速.重复性研究表明,对由数十支电缆枪组成的等离子体源而言,单支电缆枪放电分散性对其输出等离子体整体分布均匀性影响不大.不确定度分析表明,通过多次重复实验求平均值,可以有效减小实验结果的不确定度,发射密度测量结果的合成标准不确定度在10%以内.%The plasma source (cable guns) of the plasma opening switch(POS) on Qiangguang I generator was chosen as the study object. The plasma source performance was investigated by using charge collectors. Experimental results show that the plasma ejection density is positively correlated with the structural parameter, the distance between gun core tip and muzzle plane, and the plasma ejection velocity is negatively correlated with the parameter. The increasing rate of plasma ejection density is less than that of drive current. As far as a plasma source with tens of cable plasma guns is concerned, the influence of single cable gun's discharge dispersancy on plasma uniformity is little. Analysis of uncertainty shows that the uncertainty of measurement can be reduced by increasing the number of experiments and averaging the results. The combined standard uncertainty of plasma ejection density is less than 10%.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    Raptors are exposed to biomagnifying and toxic organohalogenated compounds (OHCs) such as organochlorines, brominated flame retardants and perfluorinated compounds. To investigate how OHC exposure may affect biochemical pathways we collected blood plasma from Norwegian northern goshawk (n=56......), golden eagle (n=12) and white-tailed eagle (n=36) nestlings during three consecutive breeding seasons. We found that blood plasma concentrations of calcium, sodium, creatinine, cholesterol, albumin, total protein, urea, inorganic phosphate, protein:creatinine, urea:creatinine and uric acid...

  2. GaN nanocolumns grown on Si(111) by plasma-assisted MBE: Correlation of structural and optical properties with growth parameters.

    OpenAIRE

    Fernandez-Garrido, S.; Grandal, J.; Lefebvre, Pierre; Sanchez-Garcia, M. A.; Calleja, E.

    2010-01-01

    International audience; The morphology and low-temperature photoluminescence spectra of GaN samples grown by plasma-assisted molecular beam epitaxy on Si(111) were systematically studied as a function of impinging Ga/N flux ratio and growth temperature (730-850ºC). Two different growth regimes were identified: compact and nanocolumnar. A growth diagram was established as a function of growth parameters, exhibiting the transition between growth regimes, and showing under which growth condition...

  3. Correlation between optical emission spectra and the process parameters of a 915 MHz microwave plasma CVD reactor used for depositing polycrystalline diamond coatings

    Indian Academy of Sciences (India)

    Awadesh Kumar Mallik; Sandip Bysakh; Someswar Dutta; Debabrata Basu

    2014-08-01

    In this paper, the hydrogen and hydrogen-methane mixed plasma have been generated inside a 33 cm diameter quartz bell jar with a low power (9 KW) and lower frequency 915 MHz microwave plasma chemical vapor deposition system. The reactor is being used for growing polycrystalline diamond (PCD) over large area (100 mm). The generated plasma is diagnosed by in situ optical emission spectroscopy method with wave length ranging from 200 to 900 nm. The effects of microwave power, chamber pressure and gas concentration on plasma characteristics have been studied in this work. Within the optical range, Balmer H, H, C2swan band and CH lines have been detected at the wavelengths of 655.95, 485.7, 515.82 and 430.17 nm, respectively. It has been observed that for hydrogen plasma, the amount of transition from hydrogen atom inner shell 3 to 2 (H) is almost constant with increasing microwave (MW) power (from 2000 to 2800 W) and pressure (from 15 to 30 Torr) initially, after that it increases with further increase of MW power and pressure, whereas, the transition from 4 to 2 (H) is slowly increased with increasing MW power and pressure. For hydrogen-methane plasma, intensities of C2 swan band, i.e., the transitions from D$^3\\Pi_\\text{g}$ to A$^3\\Pi_{\\mu}$ energy levels, are also increased with the increasing microwave power and reactor pressure. It has been observed that the radicals present in the plasma are affected by variation of different reactor parameters like pressure, MW power, CH4 concentration, etc.

  4. Comparison of plasma parameters and line emissions of laser-induced plasmas of an aluminum target using single and orthogonal double nanosecond/picosecond pulses

    Energy Technology Data Exchange (ETDEWEB)

    Sobral, H., E-mail: martin.sobral@ccadet.unam.mx; Sanginés, R.

    2014-04-01

    The emission of laser-induced plasma on aluminum targets in air was investigated with nanosecond- and picosecond-pulsed Nd:YAG laser emitting at the fundamental wavelength. Orthogonal double pulse in pre-ablation and reheating configurations was also performed where the picosecond laser was employed to ablate the target. Ablation fluences were kept fixed at 100 J cm{sup −2} regardless of the laser pulse duration. Time integrated emission spectroscopy was employed to determine the plasma emission; thus, picosecond laser ablation provided larger figures than the nanosecond one. The emission was further enhanced when double pulse schemes were used. This enhancement was analyzed as a function of interpulse delays. Electron density and temperature evolutions were determined from time delays of 150 ns after the ablation plasma onset. Results are discussed in terms of the ablation rate. - Highlights: • A comparison of LIBS signal keeping constant the ablation fluence is performed. • Emission of ps laser ablation is up to four-fold enlarged compared with ns pulses. • Drilling ablation efficiency is 6 times larger with ps compared with ns pulses. • LIBS sensitivity with ps pulse ablation is equivalent to that of ns double pulse configuration.

  5. Effects of RF plasma parameters on the growth of InGaN/GaN heterostructures using plasma-assisted molecular beam epitaxy

    CERN Document Server

    Shim Kyu Ha; Kim, K H; Hong, S U; Cho, K I; Lee, H G; Kim, J

    1999-01-01

    The effects of rf plasma power on the structural/optical properties of GaN-based nitride epilayers grown by plasma-assisted molecular beam epitaxy have been investigated. Atomic force microscopy and high-resolution x-ray diffraction analyses revealed that the sharp interface of In sub 0 sub . sub 2 Ga sub 0 sub . sub 8 N/GaN heterostructures could be obtained by suppressing the surface roughening at high rf power. photoluminescence data suggest that the formation of damaged subsurface due to energetic particles was alleviated in the InGaN growth in comparison with the GaN growth. In our experimental set-up, the rf power of 400 W appeared to properly suppress the 3D island formation without causing defects at the subsurface of In sub 0 sub . sub 2 Ga sub 0 sub . sub 8 N. The phenomena associated with the indium incorporation could be explained by an inequality with two kinetic processes of the surface diffusion and the plasma stimulated desorption.

  6. Serial changes of clinical parameters in a patient with advanced hepatocellular carcinoma with portal vein thrombosis achieving complete response after treatment with sorafenib

    Directory of Open Access Journals (Sweden)

    Kee KM

    2014-05-01

    Full Text Available Kwong-Ming Kee,1,2 Chao-Hung Hung,1,2 Jing-Houng Wang,1,2 Sheng-Nan Lu1,2 1Division of Hepatogastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan; 2Chang Gung University College of Medicine, Kaohsiung, Taiwan Abstract: The prognosis is usually poor in advanced hepatocellular carcinoma (HCC. Sorafenib is approved for Child-Pugh class A patients with unresectable and advanced HCC. We report here a rare case of a patient with advanced HCC with right portal vein thrombosis (PVT who achieved a complete response after treatment with sorafenib. This 74-year-old man was a case of non-hepatitis B and C virus-related cirrhosis. Multiphase liver computed tomography showed an 8 cm tumor with early enhance, early wash out, and right PVT at segment 8 of the right lobe. A liver tumor biopsy confirmed the diagnosis of poorly differentiated HCC. Blood tests showed Child-Pugh class A cirrhosis and an alpha-fetoprotein level of 33,058 ng/mL. Sorafenib was initiated at 800 mg/day but was eventually reduced to 400 mg every other day because of a grade 3 hand-foot skin reaction. The alpha fetoprotein (AFP level decreased rapidly with a linear trend after treatment. After log transformation, the calculated half-life of AFP was 6.84 days. There was no more tumor arterial enhancement, and tumor size was decreased to 3.7 cm on day 42. PVT shrank gradually and localized to the right anterior branch at month 9. There was no recurrence of tumor at the end of follow-up in month 19. Typical serial changes of clinical parameters were demonstrated in this patient. Keywords: hepatocellular carcinoma, sorafenib, complete response, portal vein thrombosis

  7. Influence of the skin effect in a rail gun on the parameters of the moving plasma piston

    Science.gov (United States)

    Iuferev, V. S.; Gnedina, M. L.; Gnedin, N. Iu.

    1992-01-01

    The problem of the motion of the plasma piston in a rail gun launcher is solved with allowance for the skin effect using plane geometry and the quasi-stationary approximation. The temperature along the piston is assumed to be constant, and the piston is assumed to move as a whole at a velocity equal to that of the accelerated projectile. It is shown that current displacement toward the rear of the piston due to the skin effect leads to an increase in the gasdynamic pressure in the plasma, with a resulting reduction in the extension of the plasmoid. The latter effect is particularly pronounced when the mass of the plasma exceeds that of the piston.

  8. Optimization of dry etching parameters for fabrication of polysilicon waveguides with smooth sidewall using a capacitively coupled plasma reactor.

    Science.gov (United States)

    Cheemalapati, Surya; Ladanov, Mikhail; Winskas, John; Pyayt, Anna

    2014-09-01

    In this paper, we demonstrate the optimization of a capacitively coupled plasma etching for the fabrication of a polysilicon waveguide with smooth sidewalls and low optical loss. A detailed experimental study on the influences of RF plasma power and chamber pressure on the roughness of the sidewalls of waveguides was conducted and waveguides were characterized using a scanning electron microscope. It was demonstrated that optimal combination of pressure (30 mTorr) and power (150 W) resulted in the smoothest sidewalls. The optical losses of the optimized waveguide were 4.1±0.6  dB/cm.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-01

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

  10. Effects of APOE rs429358, rs7412 and GSTM1/GSTT1 Polymorphism on Plasma and Erythrocyte Antioxidant Parameters and Cognition in Old Chinese Adults

    Directory of Open Access Journals (Sweden)

    Linhong Yuan

    2015-09-01

    Full Text Available Apolipoprotein E (APOE and oxidative damage were correlated with the risk of Alzheimer’s disease (AD. Glutathione S-transferase (GST polymorphism was proved to be associated with body antioxidant capacity and involved in the oxidative damage related chronic diseases. To explore the combined effects of APOE rs429358, rs7412 and GSTM1/T1 polymorphism on antioxidant parameters and cognition in old Chinese adults, a community-based cross-sectional study was carried out in 477 Chinese adults aged from 55 to 75. Information on demography and lifestyle of the participants was collected with a questionnaire. Cognitive function was measured by using a Montreal Cognitive Assessment (MoCA test. Fasting venous blood samples were collected for APOE rs429358, rs7412 and GSTM1/T1 genotyping, and parameter measurement. No association of APOE rs7412, rs429358 and GSTM1/T1 polymorphisms with cognition was detected in the old Chinese adults. APOE rs429358, rs7412 polymorphism was mainly associated with plasma α-tocopherol, low density lipoprotein cholesterol (LDL-C and plasma total antioxidant capacity (T-AOC levels (p < 0.05. Interaction of APOE rs429358 and GSTT1 genotype on the plasma triglyceride (TG level and erythrocyte catalase (CAT and GST enzyme activities were detected (p < 0.05. The subjects with APOE rs429358 T/C + C/C and GSTT1− genotype were found to have the highest plasma TG level, erythrocyte CAT enzyme activity, and the lowest GST enzyme activity compared to subjects with other genotypes (p < 0.05. Lowest erythrocyte CAT enzyme activity and highest glutathione peroxidase (GSH-Px enzyme activity were detected in the subjects with APOE rs7412 T/C + T/T and GSTM1+ genotype as compared with subjects with other genotypes. The levels of plasma and erythrocyte antioxidant parameters were APOE genotype associated. GSTM1 or GSTT1 genotype modified the influence of APOE rs7412, rs429358 polymorphism on antioxidant parameters.

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

    Directory of Open Access Journals (Sweden)

    Eitvydas GRUZDYS

    2011-07-01

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

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

    Science.gov (United States)

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

    2017-09-01

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

  13. Applying Bayesian parameter estimation to relativistic heavy-ion collisions: simultaneous characterization of the initial state and quark-gluon plasma medium

    CERN Document Server

    Bernhard, Jonah E; Bass, Steffen A; Liu, Jia; Heinz, Ulrich

    2016-01-01

    We quantitatively estimate properties of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions utilizing Bayesian statistics and a multi-parameter model-to-data comparison. The study is performed using a recently developed parametric initial condition model, TRENTO, which interpolates among a general class of particle production schemes, and a modern hybrid model which couples viscous hydrodynamics to a hadronic cascade. We calibrate the model to multiplicity, transverse momentum, and flow data and report constraints on the parametrized initial conditions and the temperature-dependent transport coefficients of the quark-gluon plasma. We show that initial entropy deposition is consistent with a saturation-based picture, extract a relation between the minimum value and slope of the temperature-dependent specific shear viscosity, and find a clear signal for a nonzero bulk viscosity.

  14. Effect of pulsed current micro plasma arc welding process parameters on fusion zone grain size and ultimate tensile strength of Inconel 625 sheets

    Institute of Scientific and Technical Information of China (English)

    Kondapalli Siva Prasad; Chalamalasetti Srinivasa Rao; Damera Nageswara Rao

    2012-01-01

    The paper focuses on developing mathematical models to predict grain size and ultimate tensile strength of pulsed current micro plasma arc welded Inconel 625 nickel alloy.Four factors,five levels,central composite rotatable design matrix is used to optimize the number of experiments.The mathematical models have been developed by response surface method.The adequacy of the models is checked by analysis of variance technique.By using the developed mathematical models,grain size and ultimate tensile strength of the joints can be predicted with 99%0 confidence level.Contour plots are drawn to study the interaction effect of pulsed current micro plasma arc welding parameters on fusion zone grain size and ultimate tensile strength of Inconel 625 weld ioints.

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

    Science.gov (United States)

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

    2016-11-08

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

  16. Influence of COsub>2sub> pressure on the emission spectra and plasma parameters in underwater laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Goueguel, Christian L; McIntyre, Dustin L; Jain, Jinesh C

    2016-12-01

    Optical emission spectroscopic studies have been carried out to investigate the pressure effect of COsub>2sub> on laser-produced underwater plasma. The plasma was generated by focusing 1064 nm, 6 ns pulses from a Nd:YAG laser in a COsub>2sub>-bearing solution. The temporal evolution of the continuum emission, Sr and Ba lines, and plasma electron density and temperature was characterized under COsub>2sub> pressure ranging from 10 to 300 bars. The electron density measurements were made using the Stark broadening of the 455.40 nm Ba II line, while the temperature measurements have been performed by the Saha-Boltzmann method using the Sr I-II lines at 460.73 and 407.77 nm, respectively. It was found that COsub>2sub> pressure has little effect on the emission line intensity and signal-to-background ratio. The electron density and the temperature are found to be independent of the COsub>2sub> pressure at early times. When time becomes longer, the electron density exhibits an appreciable rise as the COsub>2sub> pressure increases, while the temperature is found to be unchanged.

  17. Growth, testis size, spermatogenesis, semen parameters and seminal plasma and sperm membrane protein profile during the reproductive development of male goats supplemented with de-oiled castor cake.

    Science.gov (United States)

    Oliveira, C H A; Silva, A M; Silva, L M; van Tilburg, M F; Fernandes, C C L; Velho, A L M C; Moura, A A; Moreno, F B M B; Monteiro-Moreira, A C O; Moreira, R A; Lima, I M T; Rondina, D

    2015-06-01

    The present study was conducted to evaluate the effect of de-oiled castor cake on reproductive traits of crossbreed goats. Fourteen males were grouped into two lots (n = 7/group), as described: group without de-oiled castor cake (WCC) and group fed with de-oiled castor cake (CC). Goats received two diets containing a mixture of Bermudagrass hay and concentrates with the same energy (73% total digestive nutrients) and protein content (15% crude protein) during 150 days, corresponding to ages from 40 (puberty) to 60 weeks. Blood plasma concentrations of urea, albumin, lactate dehydrogenase, creatinine, alanine aminotransferase and testosterone were determined. We also evaluated scrotal circumference, sperm parameters, quantitative aspects of spermatogenesis and daily sperm production (DSP), as well as the proteome of seminal plasma and sperm membrane. Seminal fluid and sperm proteins were analyzed by 2D SDS-PAGE and mass spectrometry. After 150 days of castor cake feeding, animals had no changes in the biochemical composition of blood plasma, suggesting the absence of intoxication by ingestion of ricin. There were no alterations in dry mater intake, weight gain, testis size, peripheral concentrations of testosterone, sperm concentration, motility and morphology. Sertoli and germ cell populations in the testis and DSP were not affected either. However, there were significant variations in the expression of five seminal plasma proteins and four sperm membrane proteins. In conclusion, the replacement of soybean meal by castor cake (with ricin concentrations of 50mg/kg) did not interfere with the growth and core reproductive development of male goats. However, the diet with ricin altered the expression of certain seminal plasma and sperm membrane proteins, which play roles in sperm function and fertilization. Lower expression of these proteins may impair the ricin-fed animals to perform as high-fertility sires.

  18. Effect of calcium and cholecalciferol supplementation on several parameters of calcium status in plasma and urine of captive Asian (Elephas maximus) and African elephants (Loxodonta africana).

    Science.gov (United States)

    van Sonsbeek, Gerda R; van der Kolk, Johannes H; van Leeuwen, Johannes P T M; Everts, Hendrik; Marais, Johan; Schaftenaar, Willem

    2013-09-01

    The aim of the current study was to assess the effect of oral calcium and cholecalciferol supplementation on several parameters of calcium status in plasma and urine of captive Asian (Elephas maximus; n=10) and African elephants (Loxodonta africana; n=6) and to detect potential species differences. Calcium and cholecalciferol supplementation were investigated in a feeding trial using a crossover design consisting of five periods of 28 days each in summer. From days 28-56 (period 2), elephants were fed the Ca-supplemented diet and from days 84-112, elephants were fed the cholecalciferol-supplemented diet (period 4). The control diet was fed during the other periods and was based on their regular ration, and the study was repeated similarly during winter. Periods 1, 3, and 5 were regarded as washout periods. This study revealed species-specific differences with reference to calcium and cholecalciferol supplementation. Asian elephants showed a significant increase in mean plasma total calcium concentration following calcium supplementation during summer, suggesting summer-associated subclinical hypocalcemia in Western Europe. During winter, no effect was seen after oral calcium supplementation, but a significant increase was seen both in mean plasma, total, and ionized calcium concentrations after cholecalciferol supplementation in Asian elephants. In contrast, evidence of subclinical hypocalcemia could be demonstrated neither in summer nor in winter in African elephants, although 28 days of cholecalciferol supplementation during winter reversed the decrease in plasma 1,25(OH)2-cholecalciferol and was followed by a significant increase in mean plasma total calcium concentration. Preliminary findings indicate that the advisable permanent daily intake for calcium in Asian elephants and cholecalciferol in both elephant species at least during winter might be higher than current guidelines. It is strongly recommended to monitor blood calcium concentrations and, if

  19. Diagnostics of the plasma parameters based on the K X-ray line positions for various 4d and 4f metals

    Directory of Open Access Journals (Sweden)

    Szymańska Ewa

    2016-12-01

    Full Text Available This paper shows the theoretical predictions of the outer-shell ionization effect on the positions of Kα1,2, Kβ1,3, and K β2 X-ray lines for some 4d-transition metals (molybdenum and palladium and 4f rare-earth elements (dysprosium and ytterbium. The ionization energy shifts have been evaluated using the multiconfiguration Dirac-Fock method, containing Breit interaction and quantum electrodynamic (QED corrections. The presented results are important for obtaining the information about some parameters of plasma generated by different sources, especially by pulsed power machine and short-pulse lasers.

  20. A physical parameter method for the design of broad-band X-ray imaging systems to do coronal plasma diagnostics

    Science.gov (United States)

    Kahler, S.; Krieger, A. S.

    1978-01-01

    The technique commonly used for the analysis of data from broad-band X-ray imaging systems for plasma diagnostics is the filter ratio method. This requires the use of two or more broad-band filters to derive temperatures and line-of-sight emission integrals or emission measure distributions as a function of temperature. Here an alternative analytical approach is proposed in which the temperature response of the imaging system is matched to the physical parameter being investigated. The temperature response of a system designed to measure the total radiated power along the line of sight of any coronal structure is calculated. Other examples are discussed.

  1. Vitamin A status affects the plasma parameters and regulation of hepatic genes in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Li, Yang; Liu, Yang; Chen, Guoxun

    2017-06-01

    Vitamin A (VA) status regulates metabolism in rats. Whether VA status and availability of retinoic acid (RA) contribute to the insulin-regulated hepatic gene expression remains to be determined. Zucker lean rats with VA sufficient (VAS) or VA deficient (VAD) status were treated with streptozotocin (STZ) to induce insulin-dependent diabetes. They were treated with saline (STZ-VAS-C or STZ-VAD-C), RA (STZ-VAS-RA or STZ-VAD-RA), insulin (STZ-VAS-INS or STZ-VAD-INS), or insulin + RA (STZ-VAS-INS + RA or STZ-VAD-INS + RA) for 3 h. Insulin and insulin + RA treatments reduced tail tip blood glucose, raised plasma insulin and suppressed plasma β-hydroxybutyrate levels in both STZ-VAD and STZ-VAS rats. STZ-VAD-INS and STZ-VAD-INS + RA rats had lower plasma glucose levels than STZ-VAD-C rats had. STZ-VAD-INS and STZ-VAD-INS + RA rats had higher plasma leptin level and lower glucagon level than STZ-VAD-C rats did. Insulin treatment induced Gck, Srebp-1c and Fas and suppressed Pck1 expression levels in the liver of STZ-VAS and STZ-VAD rats. Interestingly, insulin treatment inhibited Cyp26a1 expression in STZ-VAD, but not STZ-VAS rats, whereas RA treatment induced it in both. RA treatment induced Gck expression only in STZ-VAD rats. Insulin + RA treatment further induced the Cyp26a1 and Gck expressions in STZ-VAD rats. The Srebp-1c expression levels of STZ-VAD-INS and STZ-VAD-INS + RA rats were higher than that of STZ-VAS-INS and STZ-VAS-INS + RA rats. The changes of Gck mRNA and glucokinase protein were consistent. In STZ-induced diabetic rats, VA is not required for insulin-regulated Gck, Srebp-1c, Fas and Pck1 expression. However, VA status altered responses of certain genes (Cyp26a1 and Srebp-1c) to insulin treatment. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  2. Optimization Of Pulsed Current Parameters To Minimize Pitting Corrosion İn Pulsed Current Micro Plasma Arc Welded Aısı 304l Sheets Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Kondapalli Siva Prasad

    2013-06-01

    Full Text Available Austenitic stainless steel sheets have gathered wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance, such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industry. In case of single pass welding of thinner sections of this alloy, Pulsed Current Micro Plasma Arc Welding (PCMPAW was found beneficial due to its advantages over the conventional continuous current process. This paper highlights the development of empirical mathematical equations using multiple regression analysis, correlating various process parameters to pitting corrosion rates in PCMPAW of AISI 304L sheets in 1 Normal HCl. The experiments were conducted based on a five factor, five level central composite rotatable design matrix. A Genetic Algorithm (GA was developed to optimize the process parameters for minimizing the pitting corrosion rates.

  3. Princeton Plasma Physics Laboratory:

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, C.A. (ed.)

    1986-01-01

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

  4. Selected complete blood cell count and plasma protein electrophoresis parameters in pet psittacine birds evaluated for illness.

    Science.gov (United States)

    Briscoe, Jeleen A; Rosenthal, Karen L; Shofer, Frances S

    2010-06-01

    Veterinarians rely on results of both the complete blood cell count (CBC) and plasma protein electrophoresis (EPH) in conjunction with the results of the plasma biochemical analysis to evaluate the health status of avian patients. Because the CBC and protein EPH measure different aspects of the immune response to disease, both tests are recommended in avian patients to rule out infectious or inflammatory disease. To evaluate results of the CBC and protein EPH in pet psittacine birds, the records of 144 pet psittacine birds, comprising 11 genera, that were presented for suspected illness were reviewed. Results of the CBC (total white blood cell count and packed cell volume) and protein EPH (alpha, beta, and gamma globulin concentrations) from submitted blood samples from each bird were evaluated. Of the 144 birds, 63 (43.8%) had abnormal CBC results, and 25 (17.4%) had abnormal EPH measurements. Results of the CBC and protein EPH were within reference ranges in 73 birds (50.7%). Abnormal results of the CBC in conjunction with normal EPH results were present in 46 birds (31.9%), compared with 8 birds (5.6%) with normal results of the CBC and abnormal EPH results. The findings of this study could aid practitioners in evaluating psittacine patients and prioritizing the value of individual diagnostic tests.

  5. Some biochemical parameters of blood plasma of turkey-hens following administration of 1,2,4-triasole derivative.

    Science.gov (United States)

    Krauze, M; Truchliński, J; Cendrowska-Pinkosz, M

    2007-01-01

    The present study involved 180 slaughter turkey-hens of heavy Big-6 type divided into four groups (in triplicate repetition for 15 birds). All the birds were fed with the same standard full-dose mixtures in 5-stage system. The turkey-hens of groups I, II and III were given 1,2,4-triasole derivative (3-(2-pyridil)-4-phenyl-1,2,4-triasole-5-carboxylic acid), which has antibacterial, antifungal and immunomodulating properties, in amount of 50, 75 and 100 microg per 1 dm3 of water. Group IV--control was given water without the additive. The 1,2,4-triasole derivative was given to drinking water, starting from the first day of bird's life and for the whole rearing period. The present results of biochemical analysis of blood plasma showed that addition of examined substance significantly reduced concentration of protein, glucose, triglycerides and uric acid as compared to control. It was stated that tested 1,2,4-triasole derivative elevated the level of HDL fraction percentage and alkaline phosphatase activity in blood plasma.

  6. Specific features of the radial distributions of plasma parameters in the initial segment of a supersonic jet generated by a pulsed capillary discharge

    Science.gov (United States)

    Pashchina, A. S.; Efimov, A. V.; Chinnov, V. F.; Ageev, A. G.

    2017-07-01

    Results are presented from spectroscopic studies of the initial segment of a supersonic plasma jet generated by a pulsed capillary discharge with an ablative carbon-containing polymer wall. Specific features of the spatial distributions of the electron density and intensities of spectral components caused, in particular, by the high electron temperature in the central zone, much exceeding the normal temperature, as well as by the high nonisobaricity of the initial segment of the supersonic jet, are revealed. Measurements of the radiative properties of the hot jet core (the intensity and profile of the Hα and Hβ Balmer lines and the relative intensities of C II lines) with high temporal (1-50 μs) and spatial (30-50 μm) resolutions made it possible to determine general features of the pressure and temperature distributions near the central shock. The presence of molecular components exhibiting their emission properties at the periphery of the plasma jet allowed the authors to estimate the parameters of the plasma in the jet region where "detached" shock waves form.

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

    Directory of Open Access Journals (Sweden)

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

    2010-04-01

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

  8. Processing Parameter Effects and Thermal Properties of Y2Si2O7 Nanostructured Environmental Barrier Coatings Synthesized by Solution Precursor Induction Plasma Spraying

    Science.gov (United States)

    Darthout, Émilien; Laduye, Guillaume; Gitzhofer, François

    2016-09-01

    The solution precursor plasma spray process, in which a solution of metal salts is axially injected into an induction thermal plasma, is suitable for deposition of nanostructured environmental barrier coatings. The effects of main processing parameters, namely the solution precursor concentration, spraying distance, reactor pressure, and atomization gas flow rate, have been analyzed using D-optimal design of experiments regarding the deposition rate and coating porosity responses. Among these four parameters, the solution precursor concentration had the greatest influent on the coating structure, followed by the spraying distance and reactor pressure, and finally the atomization gas flow rate with a small contribution. It is pointed out that the species that impact on the substrate are agglomerates of nanoparticles. The equivalent thermal conductivity of selected coatings was computed from experimental temperature evolution curves obtained by laser flash thermal diffusivity analysis, using two methods: a multilayer finite-element model with optimization, and a multilayer thermal diffusion model. The results of the two models agree, with coatings exhibiting low thermal conductivity between 0.7 and 1 W/(m K) at 800 °C.

  9. Processing Parameter Effects and Thermal Properties of Y2Si2O7 Nanostructured Environmental Barrier Coatings Synthesized by Solution Precursor Induction Plasma Spraying

    Science.gov (United States)

    Darthout, Émilien; Laduye, Guillaume; Gitzhofer, François

    2016-10-01

    The solution precursor plasma spray process, in which a solution of metal salts is axially injected into an induction thermal plasma, is suitable for deposition of nanostructured environmental barrier coatings. The effects of main processing parameters, namely the solution precursor concentration, spraying distance, reactor pressure, and atomization gas flow rate, have been analyzed using D-optimal design of experiments regarding the deposition rate and coating porosity responses. Among these four parameters, the solution precursor concentration had the greatest influent on the coating structure, followed by the spraying distance and reactor pressure, and finally the atomization gas flow rate with a small contribution. It is pointed out that the species that impact on the substrate are agglomerates of nanoparticles. The equivalent thermal conductivity of selected coatings was computed from experimental temperature evolution curves obtained by laser flash thermal diffusivity analysis, using two methods: a multilayer finite-element model with optimization, and a multilayer thermal diffusion model. The results of the two models agree, with coatings exhibiting low thermal conductivity between 0.7 and 1 W/(m K) at 800 °C.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    ), golden eagle (n=12) and white-tailed eagle (n=36) nestlings during three consecutive breeding seasons. We found that blood plasma concentrations of calcium, sodium, creatinine, cholesterol, albumin, total protein, urea, inorganic phosphate, protein:creatinine, urea:creatinine and uric acid...... were also negatively correlated to PCBs and PFCs, respectively. The most significant relationships were found for the highly contaminated northern goshawks and white-tailed eagles. The statistical relationships between OHCs and BCCPs indicate that biochemical pathways could be influenced while...... it is uncertain if such changes have any health effects. The OHC concentrations were below concentrations causing reproductive toxicity in adults of other raptor species but similar to those of concern for endocrine disruption of thyroid hormones in e.g., bald eagles....

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

    Directory of Open Access Journals (Sweden)

    Bartosz Fotschki

    2015-12-01

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

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

    Science.gov (United States)

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

    2015-12-21

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

  13. Avaliação da influência dos parâmetros de spray a plasma sobre a cristalinidade de recobrimentos de hidroxiapatita Effect of plasma spray process parameters on the crystallinity of hydroxyapatite coatings

    Directory of Open Access Journals (Sweden)

    S. N. da Silva

    1999-05-01

    Full Text Available Os parâmetros de spray a plasma influenciam na cristalinidade do recobrimento na medida em que determinadas condições de operação alteram a entalpia da tocha, produzindo variado grau de fusão das partículas do pó, além em de poder ainda causar modificações nas condições de resfriamento e solidificação. Neste trabalho, os efeitos dos principais parâmetros - corrente elétrica de ionização do plasma, proporção da mistura dos gases de reação e distância do bico da tocha (anodo até o substrato - sobre a cristalinidade de recobrimentos de hidroxiapatita foram avaliados. Os experimentos foram conduzidos utilizando o planejamento fatorial a três variáveis em dois níveis, com réplicas. O pó de hidroxiapatita utilizado foi da Calcitek-USA. O índice de cristalinidade dos recobrimentos nas diferentes condições foi determinado com base em método de análise quantitativa utilizando espectros de difração de raios X. O parâmetro de processo que mostrou ter maior efeito sobre a cristalinidade foi a distância tocha-substrato. O índice de cristalinidade medido para os recobrimentos produzidos variou de 20-68%. O tratamento térmico dos recobrimentos elevou o índice de cristalinidade para 99%.Plasma spraying process parameters greatly affect the coatings crystallinity since they can change the torch enthalpy, causing substantial melting of the particles and also affecting their cooling and solidification processes. In this work, the effect of the process parameters - current, proportion of primary/secondary gases and distance torch-substrate - on the crystallinity of hydroxyapatite coatings were evaluated. The experiments were carried out using a complete factorial design, with three parameters in two levels. The hydroxyapatite powder used was from Calcitek-USA. The crystallinity index was determined based on a quantitative procedure using the x-ray diffraction spectra. The process parameter which had the major effect on the

  14. Influence of the magnetic field expansion on the core plasma in an axisymmetric mirror trap

    Science.gov (United States)

    Soldatkina, E.; Anikeev, M.; Bagryansky, P.; Korzhavina, M.; Maximov, V.; Savkin, V.; Yakovlev, D.; Yushmanov, P.; Dunaevsky, A.

    2017-02-01

    First measurements of plasma parameters in an expander of a mirror trap with sub-fusion plasma parameters are reported. Potential drop near the end plates of the expander appears to be much lower than the electron temperature in the center of the trap. Characteristic energy of electrons in the expander region is also substantially lower than the electron temperature in the confinement plasma. Variation of the magnetic field expansion ratio K between 30 and 160 does not influence the main parameters of the confinement plasma. Electron temperatures of the confinement plasma of about 700 eV were achieved at K = 30.

  15. Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source.

    Science.gov (United States)

    Malapit, Giovanni M; Mahinay, Christian Lorenz S; Poral, Matthew D; Ramos, Henry J

    2012-02-01

    A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.

  16. The Study of the Grit-blasting Parameters and Their Effects on the Adhesive Strength of the Plasma Sprayed Coatings

    Institute of Scientific and Technical Information of China (English)

    M; Heydarzadeh; Sohi; M; Frooghieh; Sh; Khameneh; Asl

    2002-01-01

    Surface Preparation is very important in adhesive b on ding of spray coatings to the surface of a work piece. The common practice is gr it-blasting of the surface before subjecting it to the spray coating process. In this study, grit-blasting of an AISI 4130 steel (of different heat treatmen ts) with Al 2O 3 particles was studied. Various grit-blasting parameters such as blasting particle size, the distance between blasting nozzle and the work pi ece (25, 30 and 40 cm.), blasting pressure (3,4,5,6 and ...

  17. Effect of vitamins, probiotics and protein level on semen traits and seminal plasma biochemical parameters of post-moult male broiler breeders.

    Science.gov (United States)

    Khan, R U; Rahman, Z U; Javed, I; Muhammad, F

    2013-01-01

    1. A study was designed to investigate the comparative effect of supplementary vitamin E, vitamin C, probiotics and dietary crude protein concentration on semen traits and seminal plasma biochemical parameters in male broiler breeders after Zn-induced moulting. 2. A total of 180 male broiler breeders were induced to moult at 65 weeks of age by mixing ZnO in diet at the rate 3000 mg/kg of feed. After moulting, the males were divided into six groups that were given feed supplemented with: vitamin C (500 IU/kg), vitamin E (100 IU/kg), protein (140 g CP/kg), probiotics (50 mg/kg) and the combination of these components, while one group was kept as a control. Semen samples were collected weekly and semen volume, spermatozoa concentration, motility and dead spermatozoa percentage were determined. Seminal plasma was separated to determine the concentration of total antioxidant capacity (TAC), homocysteine, paraoxonase (PON1), arylesterase, ceruloplasmin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. 3. Semen volume was significantly higher in the vitamin E and C groups compared to the control. Spermatozoa motility was higher in the vitamin E group and dead spermatozoa percentage was significantly lower in the vitamin C group compared with the control group. 4. Seminal plasma TAC was higher in the vitamin E group, homocysteine was lower in the vitamin C and E groups. PON1 was higher in the combination group. Arylesterase increased significantly in the vitamin C and combination groups over time. Seminal plasma AST was significantly lower in the vitamin C and E supplemented groups whereas ALT decreased significantly only in the vitamin E group compared with the control. Higher concentrations of ceruloplasmin were observed in the combination group compared with the other treatments. 5. It was concluded that additional vitamin E and C or their combination was the most potent nutrient treatment for improving the semen traits and

  18. Effect of Vitamin E Supplementation on Hematological and Plasma Biochemical Parameters during Long Term Exposure of Arsenic in Goats

    Directory of Open Access Journals (Sweden)

    Tapan Kumar Das

    2012-09-01

    Full Text Available The present investigation was designed to determine whether supplementation of different level of vitamin E for 12 months to arsenic exposed goats (50 ppm as sodium arsenite affords protection against the blood hemato-biochemical parameters caused by the metalloid. A total of 24 crossbred (Alpine×Beetal lactating goats were assigned randomly into 4 equal groups (control, T1, T2 and T3 of 6 in each, on the basis of average body weight (36.10±0.11 kg and milk yield (1.61±0.04 kg/d. The animals in T1, T2 and T3 were given 50 ppm arsenic, while in T2 and T3, additionally; vitamin E at the rate of 100 IU and 150 IU/kg dry matter (DM respectively was additionally supplemented for the period of 12 months. Hemoglobin (Hb, total leukocyte (TLC and blood lymphocyte % were decreased (p0.05 but creatinine level was periodically increased in all As supplemented groups and vitamin E supplementation did not produce any protective effect. It can be concluded that arsenic exposure resulted in varying degree of changes in hemato-biochemical parameters and activities of antioxidant enzymes in goats but concomitant treatment with Vitamin E is partially helpful in reducing the burden of arsenic induced effect.

  19. Spatial and temporal variations of small-scale plasma turbulence parameters in the equatorial electrojet: HF and VHF radar observational results

    Directory of Open Access Journals (Sweden)

    G. Manju

    2005-06-01

    Full Text Available The spatial and temporal variations of various parameters associated with plasma wave turbulence in the equatorial electrojet (EEJ at the magnetic equatorial location of Trivandrum (8.5° N, 77° E; dip 0.5° N are studied for the first time, using co-located HF (18MHz and VHF (54.95MHz coherent backscatter radar observations (daytime in the altitude region of 95-110km, mostly on magnetically quiet days. The derived turbulence parameters are the mean electron density irregularity strength (δn/n, anomalous electron collision frequency (νe* and the corrected east-west electron drift velocity (Vey. The validity of the derived parameters is confirmed using radar data at two different frequencies and comparing with in-situ measurements. The behaviour of δn/n in relation to the backscattered power during weak and strong EEJ conditions is also examined to understand the growth and evolution of turbulence in the electrojet.

  20. Synthesis of graphene by cobalt-catalyzed decomposition of methane in plasma-enhanced CVD: Optimization of experimental parameters with Taguchi method

    Science.gov (United States)

    Mehedi, H.-A.; Baudrillart, B.; Alloyeau, D.; Mouhoub, O.; Ricolleau, C.; Pham, V. D.; Chacon, C.; Gicquel, A.; Lagoute, J.; Farhat, S.

    2016-08-01

    This article describes the significant roles of process parameters in the deposition of graphene films via cobalt-catalyzed decomposition of methane diluted in hydrogen using plasma-enhanced chemical vapor deposition (PECVD). The influence of growth temperature (700-850 °C), molar concentration of methane (2%-20%), growth time (30-90 s), and microwave power (300-400 W) on graphene thickness and defect density is investigated using Taguchi method which enables reaching the optimal parameter settings by performing reduced number of experiments. Growth temperature is found to be the most influential parameter in minimizing the number of graphene layers, whereas microwave power has the second largest effect on crystalline quality and minor role on thickness of graphene films. The structural properties of PECVD graphene obtained with optimized synthesis conditions are investigated with Raman spectroscopy and corroborated with atomic-scale characterization performed by high-resolution transmission electron microscopy and scanning tunneling microscopy, which reveals formation of continuous film consisting of 2-7 high quality graphene layers.

  1. Space and Astrophysical Plasmas : Matched filtering-parameter estimation method and analysis of whistlers recorded at Varanasi

    Indian Academy of Sciences (India)

    R P Singh; R P Patel; Ashok K Singh; D Hamar; J Lichtenberger

    2000-11-01

    The matched filtering technique is based on the digital-construction of theoretical whistlers and their comparison with observed whistlers. The parameters estimated from the theoretical and experimental whistler curves are matched to have higher accuracy using digital filters. This yields a resolution ten times better in the time domain. We have tested the applicability of this technique for the analysis of whistlers recorded at Varanasi. It is found that the whistlers have propagated along > 2 and have wave normal angles after exiting from the ionosphere such that they propagate towards equator in the earth-ionosphere wave-guide. High-resolution analysis shows the presence of fine structures present in the dynamic spectrum. An effort is made to interpret the results.

  2. Effect of electrical stunning current and frequency on meat quality, plasma parameters, and glycolytic potential in broilers.

    Science.gov (United States)

    Xu, L; Zhang, L; Yue, H Y; Wu, S G; Zhang, H J; Ji, F; Qi, G H

    2011-08-01

    This study was designed to determine the effect of electrical stunning variables (low currents and high frequencies) on meat quality, glycolytic potential, and blood parameters in broilers. A total of 54 broilers were stunned with 9 electrical stunning methods for 18 s using sinusoidal alternating currents combining 3 current levels (35 V, 47 mA; 50 V, 67 mA; and 65 V, 86 mA) with 3 frequencies (160, 400, and 1,000 Hz). Samples for meat quality were obtained from the pectoralis major (PM) and musculus iliofibularis (MI), and samples for glycogen metabolism were taken from the PM and tibialis anterior muscle at 45 min postmortem. The use of high frequency reduced the shear value in PM (400 and 1,000 Hz vs. 160 Hz; P 50 V, 67 mA).

  3. Effect of Vitamin E Supplementation on Hematological and Plasma Biochemical Parameters during Long Term Exposure of Arsenic in Goats.

    Science.gov (United States)

    Das, Tapan Kumar; Mani, Veena; Kaur, Harjit; Kewalramani, Neelam; Agarwal, Anjali

    2012-09-01

    The present investigation was designed to determine whether supplementation of different level of vitamin E for 12 months to arsenic exposed goats (50 ppm as sodium arsenite) affords protection against the blood hemato-biochemical parameters caused by the metalloid. A total of 24 crossbred (Alpine×Beetal) lactating goats were assigned randomly into 4 equal groups (control, T1, T2 and T3) of 6 in each, on the basis of average body weight (36.10±0.11 kg) and milk yield (1.61±0.04 kg/d). The animals in T1, T2 and T3 were given 50 ppm arsenic, while in T2 and T3, additionally; vitamin E at the rate of 100 IU and 150 IU/kg dry matter (DM) respectively was additionally supplemented for the period of 12 months. Hemoglobin (Hb), total leukocyte (TLC) and blood lymphocyte % were decreased (parsenic fed groups and vitamin E supplementation in the experimental group showed a protective potential. Significant increases (parsenic supplemented groups were recorded, however vitamin E supplementation at higher doses showed a protective effect (p0.05) but creatinine level was periodically increased in all As supplemented groups and vitamin E supplementation did not produce any protective effect. It can be concluded that arsenic exposure resulted in varying degree of changes in hemato-biochemical parameters and activities of antioxidant enzymes in goats but concomitant treatment with Vitamin E is partially helpful in reducing the burden of arsenic induced effect.

  4. Treatment of hypertension with perindopril reduces plasma atrial natriuretic peptide levels, left ventricular mass, and improves echocardiographic parameters of diastolic function

    Science.gov (United States)

    Yalcin, F.; Aksoy, F. G.; Muderrisoglu, H.; Sabah, I.; Garcia, M. J.; Thomas, J. D.

    2000-01-01

    BACKGROUND: Hypertension is a major independent risk factor for cardiac deaths, and diastolic dysfunction is a usual finding during the course of this disease. HYPOTHESIS: This study was designed to investigate the effects of chronic therapy with perindopril on left ventricular (LV) mass, left atrial size, diastolic function, and plasma level of atrial natriuretic peptide (ANP) in patients with hypertension. METHODS: Twenty four patients who had not been previously taking any antihypertensive medication and without prior history of angina pectoris, myocardial infarction, congestive heart failure, dysrhythmias, valvular heart disease, or systemic illnesses received 4-8 mg/day of perindopril orally. Echocardiographic studies were acquired at baseline and 6 months after the initiation of therapy. RESULTS: Systolic and diastolic blood pressure decreased from 174 +/- 19.7 and 107.5 +/- 7.8 mmHg to 134 +/- 10.6 and 82 +/- 6.7 mmHg, respectively (p < 0.001). Left ventricular mass decreased from 252.4 +/- 8.3 to 205.7 +/- 7.08 g and left atrial volume from 20.4 +/- 5.1 to 17.6 +/- 5.2 ml, respectively (p < 0.001). Transmitral Doppler early and atrial filling velocity ratio (E/A) increased from 0.69 +/- 0.06 to 0.92 +/- 0.05 m/s and plasma ANP level decreased from 71.9 +/- 11.7 to 35.3 +/- 7.8 pg/ml (p < 0.001). Reduction of LV mass correlated positively with a reduction in ANP levels (r = 0.66, p < 0.0005). CONCLUSIONS: Perindopril caused a significant reduction of LV mass, left atrial volume, and plasma ANP levels, as well as improvement in Doppler parameters of LV filling in this group of patients with hypertension.

  5. Effects of deposition parameters on microstructure and thermal conductivity of diamond films deposited by DC arc plasma jet chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    QU Quan-yan; QIU Wan-qi; ZENG De-chang; LIU Zhong-wu; DAI Ming-jiang; ZHOU Ke-song

    2009-01-01

    The uniform diamond films with 60 mm in diameter were deposited by improved DC arc plasma jet chemical vapor deposition technique. The structure of the film was characterized by scanning electronic microcopy(SEM) and laser Raman spectrometry. The thermal conductivity was measured by a photo thermal deflection technique. The effects of main deposition parameters on microstructure and thermal conductivity of the films were investigated. The results show that high thermal conductivity, 10.0 W/(K-cm), can be obtained at a CH4 concentration of 1.5% (volume fraction) and the substrate temperatures of 880-920 ℃ due to the high density and high purity of the film. A low pressure difference between nozzle and vacuum chamber is also beneficial to the high thermal conductivity.

  6. Effects of various power process parameters on deposition efficiency of plasma-sprayed Al2O3-40% wt.TiO2 coatings

    Science.gov (United States)

    Wang, Y. J.; Xu, J. Y.; Zhao, Q. H.; Wang, Y.; Gao, B.

    2017-06-01

    To investigate effects of various power process parameters on deposition efficiency, Al2O3-40% wt. TiO2 is selected as raw material to be coated on Q235 steel substrate by air plasma spraying. Different variables of spraying current and voltage are designed, whose spraying power is from 12.8 KW to 16.8 KW and increment step is 0.8 KW. Deposition thickness is proposed as a simple method to characterize the deposition efficiency of coatings. Analysis of variance is used to observe the difference between two adjacent groups. It is shown that deposition efficiency increases with the increase of spraying current; by and large, it firstly rises and then decreases with the increment of spraying voltage. However, the effects of increasing the latter are much stronger on deposition efficiency.

  7. Microwave plasma-assisted ALD of Al2O3 thin films: a study on the substrate temperature dependence of various parameters of interest

    Science.gov (United States)

    Thomas, Subin; Nalini, Savitha; Kumar, K. Rajeev

    2017-03-01

    This study utilizes microwave plasma-assisted atomic layer deposition (MPALD) in remote mode to deposit Al2O3 thin films with increased growth per cycle (GPC). Optical emission spectroscopy (OES) was used to identify the plasma configuration in the ALD chamber. MPALD-Al2O3 thin films were deposited at temperatures ranging from room temperature to 200 °C and the electrical parameters were investigated with Al/Al2O3/p-Si metal oxide semiconductor (MOS) structures. A GPC of 0.24 nm was observed for the films deposited at room temperature. The fixed oxide charge densities ( N fix) in all films were of the order of 1012 cm-2. The interface state density ( D it) exhibited a distinct minimum for the films deposited at 100 °C. The dependence of built-in voltage, N fix, and D it on Al2O3 deposition temperature was investigated. This can be used as a measure of the electrical applicability of these thin films.

  8. Chapter 8: Plasma operation and control

    Science.gov (United States)

    Gribov, Y.; Humphreys, D.; Kajiwara, K.; Lazarus, E. A.; Lister, J. B.; Ozeki, T.; Portone, A.; Shimada, M.; Sips, A. C. C.; Wesley, J. C.

    2007-06-01

    The ITER plasma control system has the same functional scope as the control systems in present tokamaks. These are plasma operation scenario sequencing, plasma basic control (magnetic and kinetic), plasma advanced control (control of RWMs, NTMs, ELMs, error fields, etc) and plasma fast shutdown. This chapter considers only plasma initiation and plasma basic control. This chapter describes the progress achieved in these areas in the tokamak experiments since the ITER Physics Basis (1999 Nucl. Fusion 39 2577) was written and the results of assessment of ITER to provide the plasma initiation and basic control. This assessment was done for the present ITER design (15 MA machine) at a more detailed level than it was done for the ITER design 1998 (21 MA machine) described in the ITER Physics Basis (1999 Nucl. Fusion 39 2577). The experiments on plasma initiation performed in DIII-D and JT-60U, as well as the theoretical studies performed for ITER, have demonstrated that, within specified assumptions on the plasma confinement and the impurity influx, ITER can produce plasma initiation in a low toroidal electric field (0.3 V m-1), if it is assisted by about 2 MW of ECRF heating. The plasma basic control includes control of the plasma current, position and shape—the plasma magnetic control, as well as control of other plasma global parameters or their profiles—the plasma performance control. The magnetic control is based on more reliable and simpler models of the control objects than those available at present for the plasma kinetic control. Moreover the real time diagnostics used for the magnetic control in many cases are more precise than those used for the kinetic control. Because of these reasons, the plasma magnetic control was developed for modern tokamaks and assessed for ITER better than the kinetic control. However, significant progress has been achieved in the plasma performance control during the last few years. Although the physics basis of plasma operation

  9. A contoured gap coaxial plasma gun with injected plasma armature

    Science.gov (United States)

    Witherspoon, F. Douglas; Case, Andrew; Messer, Sarah J.; Bomgardner, Richard; Phillips, Michael W.; Brockington, Samuel; Elton, Raymond

    2009-08-01

    A new coaxial plasma gun is described. The long term objective is to accelerate 100-200 μg of plasma with density above 1017 cm-3 to greater than 200 km/s with a Mach number above 10. Such high velocity dense plasma jets have a number of potential fusion applications, including plasma refueling, magnetized target fusion, injection of angular momentum into centrifugally confined mirrors, high energy density plasmas, and others. The approach uses symmetric injection of high density plasma into a coaxial electromagnetic accelerator having an annular gap geometry tailored to prevent formation of the blow-by instability. The injected plasma is generated by numerous (currently 32) radially oriented capillary discharges arranged uniformly around the circumference of the angled annular injection region of the accelerator. Magnetohydrodynamic modeling identified electrode profiles that can achieve the desired plasma jet parameters. The experimental hardware is described along with initial experimental results in which approximately 200 μg has been accelerated to 100 km/s in a half-scale prototype gun. Initial observations of 64 merging injector jets in a planar cylindrical testing array are presented. Density and velocity are presently limited by available peak current and injection sources. Steps to increase both the drive current and the injected plasma mass are described for next generation experiments.

  10. A contoured gap coaxial plasma gun with injected plasma armature.

    Science.gov (United States)

    Witherspoon, F Douglas; Case, Andrew; Messer, Sarah J; Bomgardner, Richard; Phillips, Michael W; Brockington, Samuel; Elton, Raymond

    2009-08-01

    A new coaxial plasma gun is described. The long term objective is to accelerate 100-200 microg of plasma with density above 10(17) cm(-3) to greater than 200 km/s with a Mach number above 10. Such high velocity dense plasma jets have a number of potential fusion applications, including plasma refueling, magnetized target fusion, injection of angular momentum into centrifugally confined mirrors, high energy density plasmas, and others. The approach uses symmetric injection of high density plasma into a coaxial electromagnetic accelerator having an annular gap geometry tailored to prevent formation of the blow-by instability. The injected plasma is generated by numerous (currently 32) radially oriented capillary discharges arranged uniformly around the circumference of the angled annular injection region of the accelerator. Magnetohydrodynamic modeling identified electrode profiles that can achieve the desired plasma jet parameters. The experimental hardware is described along with initial experimental results in which approximately 200 microg has been accelerated to 100 km/s in a half-scale prototype gun. Initial observations of 64 merging injector jets in a planar cylindrical testing array are presented. Density and velocity are presently limited by available peak current and injection sources. Steps to increase both the drive current and the injected plasma mass are described for next generation experiments.

  11. Irradiation of poly(tetrafluoroethylene) surfaces by CF4 plasma to achieve robust superhydrophobic and enhanced oleophilic properties for biological applications.

    Science.gov (United States)

    Salapare, Hernando S; Suarez, Beverly Anne T; Cosiñero, Hannah Shamina O; Bacaoco, Miguel Y; Ramos, Henry J

    2015-01-01

    Poly(tetrafluoroethylene) (PTFE) was irradiated by CF4 plasma produced in the gas discharge ion source facility to produce stable and robust superhydrophobic surfaces and to enhance the materials' oleophilic property for biological applications. The characterizations employed on the samples are contact angle measurements, analysis of the surface morphology (scanning electron microscopy), surface roughness measurements (atomic force microscopy) and analysis of the surface chemistry (Fourier transform infrared spectroscopy). Superhydrophobic behavior with water contact angles as high as 156° was observed. The wettability of all the treated samples was found to be stable in time as evidenced by the statistically insignificant differences in the hysteresis contact angles. The level of enhanced hydrophobicity depended on the plasma energies (i.e. irradiation times, discharge current, and discharge voltage); higher plasma energies produced surfaces with high hydrophobicity. The plasma treatment also enhanced the oleophilic property of the materials' surface as evidenced by the decrease in the PDMS-oil contact angle from 33° to as low as 10°. The superhydrophobicity of the modified PTFE and the enhancement of its oleophilic property were due to (1) the changes in the roughness of the surface, (2) the formation of nanoparticles or nanostructures on the surface, and (3) the changes in the surface chemistry.

  12. Spark Plasma Sintering constrained process parameters of sintered silver paste for connection in power electronic modules: Microstructure, mechanical and thermal properties

    Energy Technology Data Exchange (ETDEWEB)

    Alayli, N. [Université Paris 13, Sorbonne Paris Cité, Laboratoire des Sciences des Procédés et des Matériaux, Centre National de la Recherche Scientifique, Unité Propre de Recherche 3407, 99 avenue Jean Baptiste Clément, F-93430 Villetaneuse (France); Université de Versailles-Saint-Quentin-en-Yvelines, Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Centre National de la Recherche Scientifique/INSU, Laboratoire Atmosphères Milieux Observations Spatiales-IPSL, Quartier des Garennes, 11 Boulevard d' Alembert, F-78280 Guyancourt (France); Schoenstein, F., E-mail: frederic.schoenstein@univ-paris13.fr [Université Paris 13, Sorbonne Paris Cité, Laboratoire des Sciences des Procédés et des Matériaux, Centre National de la Recherche Scientifique, Unité Propre de Recherche 3407, 99 avenue Jean Baptiste Clément, F-93430 Villetaneuse (France); Girard, A. [Office National d' Étude et de Recherches Aérospatiales, Laboratoire d' Étude des Microstructures, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 104, 29 avenue de la Division Leclerc, F-92322 Châtillon (France); and others

    2014-11-14

    Processing parameters of Spark Plasma Sintering (SPS) technique were constrained to process nano sized silver particles bound in a paste for interconnection in power electronic devices. A novel strategy combining debinding step and consolidation processes (SPS) in order to elaborate nano-structured silver bulk material is investigated. Optimum parameters were sought for industrial power electronics packaging from the microstructural and morphological properties of the sintered material. The latter was studied by Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) to determine the density and the grain size of crystallites. Two types of samples, termed S1 (bulk) and S2 (multilayer) were elaborated and characterized. They are homogeneous with a low degree of porosity and a good adhesion to the substrate and the process parameters are compatible with industrial constraints. As the experimental results show, the mean crystallite size is between 60 nm and 790 nm with a density between 50% and 92% resulting in mechanical and thermal properties that are better than that of lead free solder. The best SPS sintering parameters, the applied pressure, the temperature and the processing time were determined as being 3 MPa, 300 °C and 1 min respectively when the desizing time of the preprocessing step was kept below 5 min at 150 °C. Using these processing parameters, acceptable for automotive packaging industry, a semi-conductor power chip was successfully connected to a metalized substrate by sintered silver with thermal and electrical properties better than those of current solders and with thermomechanical properties allowing absorption of thermoplastic stresses. - Highlights: • The sintered silver joints have nanometric structure. • The grain growth was controlled by the SPS sintering parameters. • New connection material improve thermal and electrical properties of current solders. • Interconnection's plastic strain can absorb thermo

  13. Magnetorotational Instability in a Couette Flow of Plasma

    CERN Document Server

    Noguchi, K; Noguchi, Koichi; Pariev, Vladimir I.

    2003-01-01

    All experiments, which have been proposed so far to model the magnetorotational instability (MRI) in the laboratory, involve a Couette flow of liquid metals in a rotating annulus. All liquid metals have small magnetic Prandtl numbers, Pm, of about 10^{-6} (the ratio of kinematic viscosity to magnetic diffusivity). With plasmas both large and small Pm are achievable by varying the temperature and the density of plasma. Compressibility and fast rotation of the plasma result in radial stratification of the equilibrium plasma density. Evolution of perturbations in radially stratified viscous and resistive plasma permeated by an axial uniform magnetic field is considered. The differential rotation of the plasma is induced by the ExB drift in applied radial electric field. Global unstable eigenmodes are calculated by our newly developed matrix code. The plasma is shown to be MRI unstable for parameters easily achievable in experimental setup.

  14. Irradiation of poly(tetrafluoroethylene) surfaces by CF{sub 4} plasma to achieve robust superhydrophobic and enhanced oleophilic properties for biological applications

    Energy Technology Data Exchange (ETDEWEB)

    Salapare, Hernando S., E-mail: hssalapare@up.edu.ph [Plasma Physics Laboratory, National Institute of Physics, College of Science, University of the Philippines Diliman, Quezon City 1101 (Philippines); eUP Office and UP Information Technology Development Center, University of the Philippines, Quezon City 1101 (Philippines); Suarez, Beverly Anne T. [Physics Department, De La Salle University, 2401 Taft Avenue, Manila (Philippines); Cosiñero, Hannah Shamina O.; Bacaoco, Miguel Y.; Ramos, Henry J. [Plasma Physics Laboratory, National Institute of Physics, College of Science, University of the Philippines Diliman, Quezon City 1101 (Philippines)

    2015-01-01

    Poly(tetrafluoroethylene) (PTFE) was irradiated by CF{sub 4} plasma produced in the gas discharge ion source facility to produce stable and robust superhydrophobic surfaces and to enhance the materials' oleophilic property for biological applications. The characterizations employed on the samples are contact angle measurements, analysis of the surface morphology (scanning electron microscopy), surface roughness measurements (atomic force microscopy) and analysis of the surface chemistry (Fourier transform infrared spectroscopy). Superhydrophobic behavior with water contact angles as high as 156° was observed. The wettability of all the treated samples was found to be stable in time as evidenced by the statistically insignificant differences in the hysteresis contact angles. The level of enhanced hydrophobicity depended on the plasma energies (i.e. irradiation times, discharge current, and discharge voltage); higher plasma energies produced surfaces with high hydrophobicity. The plasma treatment also enhanced the oleophilic property of the materials' surface as evidenced by the decrease in the PDMS-oil contact angle from 33° to as low as 10°. The superhydrophobicity of the modified PTFE and the enhancement of its oleophilic property were due to (1) the changes in the roughness of the surface, (2) the formation of nanoparticles or nanostructures on the surface, and (3) the changes in the surface chemistry. - Highlights: • PTFE surfaces were treated with direct CF{sub 4} using the gas discharge ion source. • Stable superhydrophobic behavior with water contact angles as high as 156° was recorded. • Surface roughness increased as the surface exhibited enhanced hydrophobicity. • Carbon nanoparticles were observed on the superhydrophobic PTFE surface. • Enhanced oleophilic property was observed with change in the PDMS-oil contact angle from 33° to 10°.

  15. The HelCat dual-source plasma device.

    Science.gov (United States)

    Lynn, Alan G; Gilmore, Mark; Watts, Christopher; Herrea, Janis; Kelly, Ralph; Will, Steve; Xie, Shuangwei; Yan, Lincan; Zhang, Yue

    2009-10-01

    The HelCat (Helicon-Cathode) device has been constructed to support a broad range of basic plasma science experiments relevant to the areas of solar physics, laboratory astrophysics, plasma nonlinear dynamics, and turbulence. These research topics require a relatively large plasma source capable of operating over a broad region of parameter space with a plasma duration up to at least several milliseconds. To achieve these parameters a novel dual-source system was developed utilizing both helicon and thermionic cathode sources. Plasma parameters of n(e) approximately 0.5-50 x 10(18) m(-3) and T(e) approximately 3-12 eV allow access to a wide range of collisionalities important to the research. The HelCat device and initial characterization of plasma behavior during dual-source operation are described.

  16. On the validity of setting breakpoint minimum inhibition concentrations at one quarter of the plasma concentration achieved following oral administration of oxytetracycline

    DEFF Research Database (Denmark)

    Coyne, R.; Samuelsen, O.; Bergh, Ø.

    2004-01-01

    Plasma concentrations of oxytetracycline (OTC) were established in two Atlantic salmon (Salmo salar) pre-smolts populations after they had received OTC medicated feed at a rate of 75 mg OTC/kg over 10 days. One population was experiencing an epizootic of furunculosis in a commercial freshwater farm...... and the other was held in a laboratory. Both populations were maintained at approximately 13 °C. The mean plasma concentration in 26 health farm fish was 0.25±0.06 and the 80th percentile was 0.21 mg/l. The mean concentration for 26 laboratory fish was 0.21±0.06 mg/l with an 80th percentile of 0.15 mg....../l. The validity of setting a breakpoint minimum inhibitory concentration (MIC) at a quarter of these plasma concentrations was investigated. The MIC of the Aeromonas salmonicida isolated from the farmed fish (n=7) was 0.5 mg/l and the breakpoints generated by application of the 4:1 ratio were in the range 0...

  17. Effects of supplementing rare earth element cerium on rumen fermentation, nutrient digestibility, nitrogen balance and plasma biochemical parameters in beef cattle.

    Science.gov (United States)

    Lin, S X; Wei, C; Zhao, G Y; Zhang, T T; Yang, K

    2015-12-01

    The objectives of the trial were to investigate the effects of supplementing rare earth element (REE) cerium (Ce) on rumen fermentation, nutrient digestibility, methane (CH4 ) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged at 14 months, with initial liveweight of 355 ± 8 kg and fitted with permanent rumen cannulas, were used as experimental animals. The cattle were fed with a total mixed ration (TMR) composed of concentrate mixture and corn silage. Four levels of cerium chloride (CeCl3 ·7H2 O, purity 99.9%), that is 0, 80, 160 and 240 mg CeCl3 /kg DM, were added to basal ration in a 4 × 4 Latin square design. Each experimental period lasted 15 days, of which the first 12 days were for pre-treatment and the last 3 days were for sampling. The results showed that supplementing CeCl3 at 160 or 240 mg/kg DM increased neutral detergent fibre (NDF) digestibility (p cattle increased the digestibility of NDF, decreased the molar ratio of rumen acetate to propionate, increased N retention and microbial N flow and decreased CH4 /kg DMI.

  18. Experimental investigation of plasma relaxation using a compact coaxial magnetized plasma gun in a background plasma

    Science.gov (United States)

    Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott; University of New Mexico Collaboration; Los Alamos National Laboratory Collaboration

    2013-10-01

    A compact coaxial plasma gun is employed for experimental studies of plasma relaxation in a low density background plasma. Experiments are being conducted in the linear HelCat device at UNM. These studies will advance the knowledge of basic plasma physics in the areas of magnetic relaxation and space and astrophysical plasmas, including the evolution of active galactic jets/radio lobes within the intergalactic medium. The gun is powered by a 120pF ignitron-switched capacitor bank which is operated in a range of 5-10 kV and ~100 kA. Multiple diagnostics are employed to investigate plasma relaxation process. Magnetized Argon plasma bubbles with velocities ~1.2Cs and densities ~1020 m-3 have been achieved. Different distinct regimes of operation with qualitatively different dynamics are identified by fast CCD camera images, with the parameter determining the operation regime. Additionally, a B-dot probe array is employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify detached plasma bubble configurations. Experimental data and analysis will be presented.

  19. Initial dosing regimen of vancomycin to achieve early therapeutic plasma concentration in critically ill patients with MRSA infection based on APACHE II score.

    Science.gov (United States)

    Imaura, Masaharu; Yokoyama, Haruko; Kohata, Yuji; Kanai, Riichiro; Kohyama, Tomoki; Idemitsu, Wataru; Maki, Yuichi; Igarashi, Takashi; Takahashi, Hiroyuki; Kanno, Hiroshi; Yamada, Yasuhiko

    2016-06-01

    It is essential to assure the efficacy of antimicrobials at the initial phase of therapy. However, increasing the volume of distribution (Vd) of hydrophilic antimicrobials in critically ill patients leads to reduced antimicrobial concentration in plasma and tissue, which may adversely affect the efficacy of that therapy. The aim of the present study was to establish a theoretical methodology for setting an appropriate level for initial vancomycin therapy in individual patients based on Acute Physiology and Chronic Health Evaluation (APACHE) II score. We obtained data from patients who received intravenous vancomycin for a suspected or definitively diagnosed Gram-positive bacterial infection within 72 h after admission to the intensive care unit. The Vd and elimination half-life (t 1/2) of vancomycin values were calculated using the Bayesian method, and we investigated the relationship between them and APACHE II score. There were significant correlations between APACHE II scores and Vd/actual body weight (ABW), as well as t 1/2 (r = 0.58, p < 0.05 and r = 0.74, p < 0.01, respectively). Our results suggested that the Vd and t 1/2 of vancomycin could be estimated using the following regression equations using APACHE II score.[Formula: see text] [Formula: see text]We found that APACHE II score was a useful index for predicting the Vd and t 1/2 of vancomycin, and used that to establish an initial vancomycin dosing regimen comprised of initial dose and administration interval for individual patients.

  20. Achieving scale-independent land-surface flux estimates - Application of the Multiscale Parameter Regionalization (MPR) to the Noah-MP land-surface model across the contiguous USA

    Science.gov (United States)

    Thober, S.; Mizukami, N.; Samaniego, L. E.; Attinger, S.; Clark, M. P.; Cuntz, M.

    2016-12-01

    classical averaging operators used in MPR. This allows us to identify appropriate scalings for parameters that have not been investigated in MPR so far (e.g., maximum carboxylation rate). Using MPR for Noah-MP provides a considerable improvement of the physical consistency that we expect to be achievable also in other land-surface schemes.

  1. Multicapillary cathode controlled by a ferroelectric plasma source

    Science.gov (United States)

    Gleizer, J. Z.; Hadas, Y.; Krasik, Ya. E.

    2008-06-01

    We present results of high-current microsecond and sub-microsecond duration electron beam generation in a ~200 kV diode with a multicapillary dielectric cathode (MCDC) assisted by a ferroelectric plasma source (FPS). Electron beam current densities are achieved up to 40 A/cm2. It was shown that the operation of the MCDC is determined by the parameters of the plasma flow generated by the FPS. Also, it was found that the high resistivity of the plasma produced inside the capillaries allows effective de-coupling of individual capillary plasma discharges which results in uniform electron beam generation.

  2. GRAVIMETRIC-DETERMINATION OF THE WATER CONCENTRATION IN WHOLE-BLOOD, PLASMA AND ERYTHROCYTES AND CORRELATIONS WITH HEMATOLOGICAL AND CLINICOCHEMICAL PARAMETERS

    NARCIS (Netherlands)

    LIJNEMA, TH; HUIZENGA, [No Value; JAGER, J; MACKOR, AJ; GIPS, CH

    1993-01-01

    We have assessed gravimetric methods for determination of intravascular water, established whole blood-, plasma- and erythrocyte water reference values in a healthy volunteer group (n = 97, 48 females) and correlated these variables with 30 simultaneous hematological, clinicochemical and body parame

  3. The influence of low-level laser therapy on parameters of oxidative stress and DNA damage on muscle and plasma in rats with heart failure.

    Science.gov (United States)

    Biasibetti, Micheli; Rojas, Denise B; Hentschke, Vítor S; Moura, Dinara Jaqueline; Karsten, Marlus; Wannmacher, Clóvis M D; Saffi, Jenifer; Dal Lago, Pedro

    2014-11-01

    In heart failure (HF), there is an imbalance between the production of reactive oxygen species and the synthesis of antioxidant enzymes, causing damage to the cardiovascular function and increased susceptibility to DNA damage. The aim of this study was to evaluate the influence of low-level laser therapy (LLLT) on parameters of oxidative stress and DNA damage in skeletal muscle and plasma of rats with HF. Wistar rats were allocated into six groups: "placebo" HF rats (P-HF, n = 9), "placebo" Sham rats (P-sham, n = 8), HF rats at a dose 3 J/cm(2) of LLLT (3 J/cm(2)-HF, n = 8), sham rats at a dose 3 J/cm(2) of LLLT (3 J/cm(2)-sham, n = 8), HF rats at a dose 21 J/cm(2) of LLLT (21 J/cm(2)-HF, n = 8) and sham rats at a dose 21 J/cm(2) of LLLT (21 J/cm(2)-sham, n = 8). Animals were submitted to a LLLT protocol for 10 days at the right gastrocnemius muscle. Comparison between groups showed a significant reduction in superoxide dismutase (SOD) activity in the 3 J/cm(2)-HF group (p = 0.03) and the 21 J/cm(2)-HF group (p = 0.01) compared to the P-HF group. 2',7'-Dihydrodichlorofluorescein (DCFH) oxidation levels showed a decrease when comparing 3 J/cm(2)-sham to P-sham (p = 0.02). The DNA damage index had a significant increase either in 21 J/cm(2)-HF or 21 J/cm(2)-sham in comparison to P-HF (p = 0.004) and P-sham (p = 0.001) and to 3 J/cm(2)-HF (p = 0.007) and 3 J/cm(2)-sham (p = 0.037), respectively. Based on this, laser therapy appears to reduce SOD activity and DCFH oxidation levels, changing the oxidative balance in the skeletal muscle of HF rats. Otherwise, high doses of LLLT seem to increase DNA damage.

  4. Effect of a microbial phytase on growth performance, plasma parameters and apparent ileal amino acid digestibility in Youxian Sheldrake fed a low-phosphorus corn-soybean diet

    Directory of Open Access Journals (Sweden)

    Shaoping He

    2017-10-01

    Full Text Available Objective This study investigated the effect of microbial phytase supplementation on growth performance, tibia ash, plasma parameters, apparent ileal digestibility (AID of amino acid (AA and apparent digestibility of nutrients in Youxian Sheldrakes fed with low-phosphorus (P corn-soybean diets. Methods A total of 350 Youxian Sheldrakes (7d old were randomly divided into 5 treatment groups: positive control (PC group has adequate available P diet (0.42% and 0.38%, starter and grower, negative control (NC group were deficient in available P (0.32% and 0.28%, starter and grower and NC diet was supplemented with 3 levels of microbial phytase (500, 750, and 1,000 U/kg. Results Dietary supplementation of phytase in NC diet improved the average daily gain, increased the levels of serum calcium (Ca, tibia Ca and P, AID of AA and apparent digestibility of energy and Ca in starter stage (p<0.05. There was an increased (p<0.001 in the utilization of P from 17.3% to 23.9%. Phytase supplementation (1,000 U/kg has shown that the AID of His, Thr, Val, indispensable AA, Glu, Pro, and dispensable AA was higher (p<0.05 than that of NC. Moreover, phytase supplementation improved (p<0.05 serum and tibia Ca and P, AID of AA and apparent digestibility of dry matter, crude protein, energy, P and Ca, and reduced (p<0.05 feed to gain ratio (F/G and the levels of serum alkaline phosphatase in grower stage. Likewise, an increase (p<0.001 in the utilization of P was noticed from 12.6% to 17.2%. Supplement phytase at 750 U/kg improved the AID of His, Thr, Asp, Cys, Pro, and Ser (p<0.05. Conclusion The microbial phytase supplement could improve growth performance, AID of some AA and apparent utilization of other nutrients in Youxian Sheldrakes, and reduce excreta P load to environment.

  5. Exact relativistic kinetic theory of an electron beam-plasma system: hierarchy of the competing modes in the system parameter space

    OpenAIRE

    Bret, A.; Gremillet, L; Benisti, D.; Lefebvre, E.

    2008-01-01

    Besides being one of the most fundamental basic issues of plasma physics, the stability analysis of an electron beam-plasma system is of critical relevance in many areas of physics. Surprisingly, decades of extensive investigation had not yet resulted in a realistic unified picture of the multidimensional unstable spectrum within a fully relativistic and kinetic framework. All attempts made so far in this direction were indeed restricted to simplistic distribution functions and/or did not aim...

  6. Effects of the electrical excitation signal parameters on the geometry of an argon-based non-thermal atmospheric pressure plasma jet.

    Science.gov (United States)

    Benabbas, Mohamed Tahar; Sahli, Salah; Benhamouda, Abdallah; Rebiai, Saida

    2014-12-01

    A non-thermal atmospheric pressure argon plasma jet for medical applications has been generated using a high-voltage pulse generator and a homemade dielectric barrier discharge (DBD) reactor with a cylindrical configuration. A plasma jet of about 6 cm of length has been created in argon gas at atmospheric pressure with an applied peak to peak voltage and a frequency of 10 kV and 50 kHz, respectively. The length and the shape of the created plasma jet were found to be strongly dependent on the electrode setup and the applied voltage and the signal frequency values. The length of the plasma jet increases when the applied voltage and/or its frequency increase, while the diameter at its end is significantly reduced when the applied signal frequency increases. For an applied voltage of 10 kV, the plasma jet diameter decreases from near 5 mm for a frequency of 10 kHz to less than 1 mm at a frequency of 50 kHz. This obtained size of the plasma jet diameter is very useful when the medical treatment must be processed in a reduced space. PACS 2008: 52.50.Dg; 52.70.-m; 52.80.-s.

  7. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2014-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...

  8. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan

    2016-01-01

    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has...

  9. Achieving professionalism

    Directory of Open Access Journals (Sweden)

    R.A.E. Thompson

    1983-09-01

    Full Text Available In approaching the subject of professionalism the author has chosen to focus on the practical aspects rather than the philosophical issues. In so doing an attempt is made to identify criteria which demonstrate the achievement of the essence of professionalism.

  10. DC and Wave Electric Fields and Other Plasma Parameters Observed on Two Sounding Rockets in the Dark Cusp during IMF Bz North and South Conditions

    Science.gov (United States)

    Pfaff, R. F.; Acuna, M.; Bounds, S.; Farrell, W.; Freudenreich, W.; Lepping, R.; Vondrak, R.; Maynard, N. C.; Moen, J.; Egeland, A.

    1999-01-01

    Two Black Brant IX sounding rockets were launched into the dark, dayside cusp near magnetic noon on December 2 and 3, 1997, from Ny Alesund, Spitzbergen at 79 deg N reaching altitudes of about 450 km. Real-time ground-based and Wind IMF data were used to determine the launch conditions. The first launch, with Bz north conditions, crossed into and back out of an open field region with merging poleward of the projected trajectory. The second flight, into Bz south conditions, was timed to coincide with an enhancement in the merging rate from a increase in the negative Bz, while the DMSP Fl 3 satellite was situated slightly to the north of the rocket trajectory. Each payload returned DC electric and magnetic fields, plasma waves, energetic particles, photometer data, and thermal plasma data. Data from both flights will be shown, with an emphasis on the DC electric field results. In particular, the data gathered on December 2, 1997 will be used to discuss ionospheric signatures of merging and the open/closed character of the the cusp/low latitude boundary layer. In contrast, the data gathered on December 3, 1997 shows evidence of pulsed electric field structures which will be examined in the context of cusp plasma entry processes. Both data sets returned a rich variety of plasma waves, as well as optical emissions and thermal plasma data.

  11. Taguchi Analysis on the Effect of Process Parameters on Densification During Spark Plasma Sintering of HfB2-20SiC (Preprint)

    Science.gov (United States)

    2011-11-01

    pressing and spark plasma sintering. J Alloys Compd 2007; 428:197–05. 2. Van Wie D.M., Drewry Jr. D.G., King D.E., Hudson C.M. The hypersonic environment...spark plasma sintering of HfB2/SiC and HfB2/HfC/SiC composite powders obtained by self-propagating high-temperature synthesis. J Alloys Compd 2009...2008; 91:10:3448-50. 9. Carmen M Carney. Oxidation resistance of hafnium diboride—silicon carbide from 1400 to 2000 °C. J Mater Sci 2009; 44:20:5673-81

  12. Influence of Operating Parameters on Surface Properties of RF Glow Discharge Oxygen Plasma Treated TiO2/PET Film for Biomedical Application

    Science.gov (United States)

    Thin transparent titania (TiO2) films were coated on the surface of flexible poly (ethylene terephthalate) (PET) surface using standard sol gel techniques. The TiO2/PET thin film surfaces were further modified by exposing the films to a RF glow discharge oxygen plasma. The exposu...

  13. Influence of Operating Parameters on Surface Properties of RF Glow Discharge Oxygen Plasma Treated TiO2/PET Film for Biomedical Application

    Science.gov (United States)

    Thin transparent titania (TiO2) films were coated on the surface of flexible poly (ethylene terephthalate) (PET) surface using standard sol gel techniques. The TiO2/PET thin film surfaces were further modified by exposing the films to a RF glow discharge oxygen plasma. The exposu...

  14. Influence of operating parameters on surface properties of RF glow discharge oxygen plasma treated TiO₂/PET film for biomedical application.

    Science.gov (United States)

    Pandiyaraj, K Navaneetha; Deshmukh, R R; Mahendiran, R; Su, Pi-G; Yassitepe, Emre; Shah, Ismat; Perni, Stefano; Prokopovich, Polina; Nadagouda, Mallikarjuna N

    2014-03-01

    In this paper, a thin transparent titania (TiO2) film was coated on the surface of flexible poly(ethylene terephthalate) (PET) film using the sol-gel method. The surface properties of the obtained TiO2/PET film were further improved by RF glow discharge oxygen plasma as a function of exposure time and discharge power. The changes in hydrophilicity of TiO2/PET films were analyzed by contact angle measurements and surface energy. The influence of plasma on the surface of the TiO2/PET films was analyzed by atomic force microscopy (AFM) as well as the change in chemical state and composition that were investigated by X-ray photo electron spectroscopy (XPS). The cytotoxicity of the TiO2/PET films was analyzed using human osteoblast cells and the bacterial eradication behaviors of TiO2/PET films were also evaluated against Staphylococcus bacteria. It was found that the surface roughness and incorporation of oxygen containing polar functional groups of the plasma treated TiO2/PET films increased substantially as compared to the untreated one. Moreover the increased concentration of Ti(3+) on the surface of plasma treated TiO2/PET films was due to the transformation of chemical states (Ti(4+)→Ti(3+)). These morphological and chemical changes are responsible for enhanced hydrophilicity of the TiO2/PET films. Furthermore, the plasma treated TiO2/PET film exhibited no citotoxicity against osteoblast cells and antibacterial activity against Staphylococcus bacteria which can find application in manufacturing of biomedical devices.

  15. Design and Construction of a Microwave Plasma Ion Source

    CERN Document Server

    Çınar, Kamil

    2011-01-01

    This thesis is about the designing and constructing a microwave ion source. The ions are generated in a thermal and dense hydrogen plasma by microwave induction. The plasma is generated by using a microwave source with a frequency of 2.45 GHz and a power of 700 W. The generated microwave is pulsing with a frequency of 50 Hz. The designed and constructed microwave system generates hydrogen plasma in a pyrex plasma chamber. Moreover, an ion extraction unit is designed and constructed in order to extract the ions from the generated hydrogen plasma. The ion beam extraction is achieved and ion currents are measured. The plasma parameters are determined by a double Langmuir probe and the ion current is measured by a Faraday cup. The designed ion extraction unit is simulated by using the dimensions of the designed and constructed ion extraction unit in order to trace out the trajectories of the extracted ions.

  16. A Novel Microwave Beam Steering Technique Using Plasma

    Science.gov (United States)

    Linardakis, Peter; Borg, Gerard G.; Harris, Jeffrey H.; Martin, Noel M.

    2002-10-01

    At frequencies above the plasma frequency, electromagnetic waves propagate through plasma with a wavelength longer than the free space wavelength. As a result, a plasma with a centrally peaked density profile can deflect rather than focus electromagnetic waves. We present a plasma device designed specifically to deflect a microwave beam as an alternative to conventional beam deflectors based on antenna arrays. A 22^rc deflection of Ka band microwave has been achieved using a laboratory plasma, with no detrimental effect on the beamwidth or side-lode level and structure. The use of a simple WKB model shows agreement and that the deflection can be increased with appropriate design. Results indicate the potential for increases in dynamic range, in power handling (for example from a gyrotron) and for the reduction of insertion losses over current beam steering systems. A ``plasma lens'' demonstrator device has also been designed to test practical performance aspects such as phase noise and to test optimization parameters.

  17. Introduction to Plasma Physics

    Science.gov (United States)

    Gurnett, Donald A.; Bhattacharjee, Amitava

    2017-03-01

    Preface; 1. Introduction; 2. Characteristic parameters of a plasma; 3. Single particle motions; 4. Waves in a cold plasma; 5. Kinetic theory and the moment equations; 6. Magnetohydrodynamics; 7. MHD equilibria and stability; 8. Discontinuities and shock waves; 9. Electrostatic waves in a hot unmagnetized plasma; 10. Waves in a hot magnetized plasma; 11. Nonlinear effects; 12. Collisional processes; Appendix A. Symbols; Appendix B. Useful trigonometric identities; Appendix C. Vector differential operators; Appendix D. Vector calculus identities; Index.

  18. Profiles of plasma parameters and density of negative hydrogen ions by laser detachment measurements in RF-driven ion sources; Profile der Plasmaparameter und Dichte negativer Wasserstoffionen mittels Laserdetachmentmessungen in HF-angeregten Ionenquellen

    Energy Technology Data Exchange (ETDEWEB)

    Christ-Koch, Sina

    2007-12-20

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

  19. Changes in plasma levels of ghrelin, leptin, and other hormonal and metabolic parameters following standardized breakfast, lunch, and physical exercise before and after a multidisciplinary weight-reduction intervention in obese adolescents.

    Science.gov (United States)

    Rigamonti, A E; Agosti, F; De Col, A; Marazzi, N; Lafortuna, C L; Cella, S G; Muller, E E; Sartorio, A

    2010-10-01

    To investigate in severely obese adolescents the effects of a 3-week multidisciplinary weight-reduction intervention involving moderate energy restriction, individualised physical activity and behavior therapy on the response of some hormonal and metabolic parameters to meals and exercise. Clinical longitudinal study on inpatients in a specialised institution. A total of 20 obese adolescents (10 boys and 10 girls) aged 12-17 yr [body mass index (BMI): 37.7±6.1 kg/m2; fat mass (FM): 44.8±13.2 kg]. The changes in plasma concentration of leptin, ghrelin, GH, IGF-I, insulin, glucose, and non-esterified fatty acids (NEFA) in response to standardised meals and exercise bouts were measured before and after the weight-reduction intervention. At the same times, body composition was assessed by bioelectrical impedance as well as appetite sensations using a visual analog scale. At the end of the intervention, the adolescents had lost body weight and FM (expressed both in kg and %) (pexercise, after the 3-week intervention, plasma leptin concentration decreased significantly (pghrelin, GH, and IGF-I) and metabolic parameters (glucose and NEFA) did not change. Interestingly, appetite was not affected by the intervention. This 3-week multidisciplinary intervention in obese adolescents induced a significant body weight loss with beneficial changes in body composition. However, despite there being no change in metabolic parameters and ghrelin in response to meals and exercise after the intervention, plasma concentrations of leptin were decreased. The failure of ghrelin levels to increase by this approach might explain the good control of appetite observed at the end of the study.

  20. Study of the characteristics of reconfigurable plasma antenna array

    Energy Technology Data Exchange (ETDEWEB)

    Alias, Nur Salihah; Dagang, Ahmad Nazri [School of Ocean Engineering, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu (Malaysia); Ali, Mohd Tarmizi [Microwave Technology Centre, Faculty of Electrical Engineering, Universiti Teknologi Mara Shah Alam 40450 Shah Alam, Selangor (Malaysia)

    2015-04-24

    This paper presents a design and simulation of a reconfigurable array of plasma antenna. The plasma column is used as radiating elements instead of metal to create an antenna. The advantages of the plasma antenna over the conventional antenna are its possible to change the operating parameters, such as the working pressure, input power, radius of the discharge tube, resonant frequency, and length of the plasma column. In addition, plasma antenna can be reconfigurable with respect to shape, frequency and radiation parameters in a very short time. The plasma discharge tube was designed with a length of 200 mm, the radius of the plasma column was 2.5 mm and the coupling sleeve was connected to the SMA as the ground. This simulation was performed by using the simulation software Computer Simulation Technology (CST). The frequency is set in the range of 1 GHz to 10 GHz. The performance of the designed antenna was analyzed in term of return loss, gain and radiation pattern. For reconfigurable plasma antenna array, it shows that the gain is increase when the number of antenna element is increase. The combination of the discharge tube and metal rod as an antenna array has been done, and the result shows that an array with the plasma element can achieve higher gain.

  1. Addition of oral iron to plasma transfusion in human congenital hypotransferrinemia: A 10-year observational follow-up with the effects on hematological parameters and growth.

    Science.gov (United States)

    Aslan, Deniz

    2017-09-12

    Congenital hypotransferrinemia (OMIM 209300) is an extremely rare disorder of inherited iron metabolism. Since its description in 1961, only 16 cases have been reported. The defective gene and molecular defect causing this disorder and clinicolaboratory findings seen in the homozygous and heterozygous states have been documented in both humans and mice. However, due to the lack of follow-up studies of the described cases, the long-term prognosis remains unknown. We present a 10-year observational follow-up of a patient previously diagnosed on a molecular basis who was treated with a unique therapy of plasma transfusion fortified with oral iron, with satisfactory clinicolaboratory responses. © 2017 Wiley Periodicals, Inc.

  2. plasma treatment

    Directory of Open Access Journals (Sweden)

    Puač Nevena

    2014-11-01

    Full Text Available In this paper we will present results for plasma sterilization of planktonic samples of two reference strains of bacteria, Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. We have used a plasma needle as a source of non-equilibrium atmospheric plasma in all treatments. This device is already well characterized by OES, derivative probes and mass spectrometry. It was shown that power delivered to the plasma is bellow 2 W and that it produces the main radical oxygen and nitrogen species believed to be responsible for the sterilization process. Here we will only present results obtained by electron paramagnetic resonance which was used to detect the OH, H and NO species. Treatment time and power delivered to the plasma were found to have the strongest influence on sterilization. In all cases we have observed a reduction of several orders of magnitude in the concentration of bacteria and for the longest treatment time complete eradication. A more efficient sterilization was achieved in the case of gram negative bacteria.

  3. 用于新型雷达/红外无源复合诱饵的等离子体参数选择%Parameters Choice of Plasma for New Types of Passive Radar and Infrared Compound Decoy

    Institute of Scientific and Technical Information of China (English)

    汪中贤; 韩磊; 史建军; 张正武

    2012-01-01

    根据电磁波在分层介质中阻抗匹配原理,计算了非均匀非磁化等离子体平行与垂直极化波的功率反射系数。基于碱金属盐的高温电离特性,以功率反射系数为研究对象,对雷达无源诱饵用等离子体的厚度、温度和电子密度分布等参数选择进行了分析,并根据所选择的参数讨论了入射角对无源诱饵应用的影响。%According to the impedance matching mechanism when incident microwave transmit in the non-uniform substance,the total wave energy reflectance calculating method of TE wave and TM wave on the surface of plasma was introduced in this paper.The choices of the thickness,temperature and distributing of uncontrolled electron of plasma used for radar passive decoy were studied according to the total wave energy reflectance based on the ionization specialty of the compound alkali metals.And according to the parameters of plasma chosen above,the application impact of radar passive decoy was analyzed under various incidence angle of microwave.

  4. Pulsed plasma electron sourcesa)

    Science.gov (United States)

    Krasik, Ya. E.; Yarmolich, D.; Gleizer, J. Z.; Vekselman, V.; Hadas, Y.; Gurovich, V. Tz.; Felsteiner, J.

    2009-05-01

    There is a continuous interest in research of electron sources which can be used for generation of uniform electron beams produced at E ≤105 V/cm and duration ≤10-5 s. In this review, several types of plasma electron sources will be considered, namely, passive (metal ceramic, velvet and carbon fiber with and without CsI coating, and multicapillary and multislot cathodes) and active (ferroelectric and hollow anodes) plasma sources. The operation of passive sources is governed by the formation of flashover plasma whose parameters depend on the amplitude and rise time of the accelerating electric field. In the case of ferroelectric and hollow-anode plasma sources the plasma parameters are controlled by the driving pulse and discharge current, respectively. Using different time- and space-resolved electrical, optical, spectroscopical, Thomson scattering and x-ray diagnostics, the parameters of the plasma and generated electron beam were characterized.

  5. Investigation of the AC Plasma Torch Working Conditions for the Plasma Chemical Applications

    Science.gov (United States)

    Safronov, A. A.; Vasilieva, O. B.; Dudnik, J. D.; E Kuznetsov, V.; Shiryaev, V. N.; Subbotin, D. I.; Pavlov, A. V.

    2017-04-01

    The presented design and parameters of a three-phase AC plasma torch with the power up to 500 kW, flow rate of air 30-50 g/s (temperature up to 5000 K) could be used in different plasma chemical processes. Range of measured plasma temperature is 3500-5000 K. The paper presents investigations of the plasma torch operation modes for its application in plasma chemical technologies. Plasma chemical technologies for various purposes (processing, destruction of various wastes, including technological and hazardous waste, conversion or production of chemicals to obtain nanoscale materials, etc.) are very promising in terms of the process efficiency. Their industrial use is difficult due to the lack of inexpensive and reliable plasma torches providing the desired level of temperature, enthalpy of the working gas and other necessary conditions for the process. This problem can be solved using a considered design of a three-phase alternating current plasma torch with power of 150-500 kW with working gas flow rate of 30-50 g/s with mass average temperature up to 5000K on the basis of which an industrial plasma chemical plant can be created. The basis of the plasma torch operation is a railgun effect that is the principle of arc movement in the field of its own current field. Thanks to single supply of power to the arc, arcs forming in the discharge chamber of the plasma torch move along the electrodes under the action of electrodynamic forces resulting from the interaction of the arc current with its own magnetic field. Under the condition of the three-phase supply voltage, arc transits from the electrode to the electrode with change in the anodic and cathodic phases with frequency of 300 Hz. A special feature of this design is the ability to organize the movement of the arc attachment along the electrode, thus ensuring an even distribution of the thermal load and thus achieve long time of continuous operation of the plasma torch. The parameters of the plasma jet of the

  6. Experimental investigation in plasma relaxation by using a compact coaxial magnetized plasma gun in a background plasma

    Science.gov (United States)

    Zhang, Yue; Lynn, Alan; Gilmore, Mark; Hsu, Scott

    2012-10-01

    A compact coaxial plasma gun is employed for experimental studies of plasma relaxation process being conducted in the HELCAT device at UNM. These studies will advance the knowledge of basic plasma physics in the areas of magnetic relaxation and space and astrophysical plasmas, including the evolution of active galactic jets/radio lobes. The gun is powered by a 120pF ignitron-switched capacitor bank which is operated in a range of 5 - 10kV. Multiple diagnostics are employed to investigate plasma relaxation process. Magnetized Argon plasma bubbles with velocities 1.2Cs and densities 10e20 m-3 have been achieved. Different distinct regimes of operation with qualitatively different dynamics are identified by fast CCD camera images, with the parameter lambda determining the operation regime. Additionally, a B-dot probe array is employed to measure the spatial toroidal and poloidal magnetic flux evolution to identify detached plasma bubble configurations. Experimental data and analysis will be presented.

  7. 不育男性精浆生化标志物与精液参数分析%Analyse of biochemical marker in seminal plasma and sperm parameters of infertile male

    Institute of Scientific and Technical Information of China (English)

    何雁; 王岚; 高婷; 伏建峰; 刘俊

    2011-01-01

    Objective: To investigate the important role of biochemical marker of seminal plasma in male fertility evaluation, and the relationship between biochemical marker and sperm parameters. Methods: The activities of zinc and acid phosphatase in seminal plasma were routinely detected in 97 infertile men and 30 normal fertility as control. We carried out the biochemical detection of seminal plasma, including fructose content, acid phosphatase content, α - glycosidase content and zinc content. The data was be statistically analysed by SPSS - 11.0 software. Results: ①The seminal plasma fructose content of anormal sperm density in infertile group is significant higher than normal sperm density in infertile group or normal fertility group ( P < 0. 05 ); The seminal plasma fructose content of anormal sperm activity in infertile group have significant difference than normal fertility group ( P < 0.05 ). ② The seminal plasma acid phosphatase content of anormal sperm activity in infertile group is significant lower than normal sperm activity in infertile group or normal fertility group ( P < 0.05 ); The seminal plasma acid phosphatase content of anormal sperm density in infertile group have no statistical difference with normal sperm density in infertile group or normal fertility group ( P > 0.05 ). ③The seminal plasma α - glycosidase content of anormal sperm density in infertile group is significant lower than normal sperm density in infertile group or normal fertility group (P <0.05); The seminal plasma α - glycosidase content nf anormal sperm activity in infertile group is significant lower than normal sperm activity in infertile group or normal fertility group ( P < 0.05 ). ④The seminal plasma zinc content of anormal sperm density in infertile group is significant lower than normal sperm density in infertile group or normal fertility group (P <0.01 ); The seminal plasma zinc content of anormal sperm activity in infertile group have no statistical

  8. Princeton University, Plasma Physics Laboratory annual report, October 1, 1988--September 30, 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    This report contains discussions on the following topics: principal parameters achieved in experimental devices (FY89); tokamak fusion test reactor; compact ignition tokamak; princeton beta experiment- modification; current drive experiment; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for (FY89); graduate education: plasma physics; graduate education: plasma science and technology; and Princeton Plasmas Physics Laboratory Reports (FY89).

  9. Princeton University, Plasma Physics Laboratory annual report, October 1, 1988--September 30, 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-12-31

    This report contains discussions on the following topics: principal parameters achieved in experimental devices (FY89); tokamak fusion test reactor; compact ignition tokamak; princeton beta experiment- modification; current drive experiment; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for (FY89); graduate education: plasma physics; graduate education: plasma science and technology; and Princeton Plasmas Physics Laboratory Reports (FY89).

  10. Princeton Plasma Physics Laboratory. Annual report, October 1, 1989--September 30, 1990

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

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

  11. Fast Tunable Microwave Devices Using Self-driven Plasma Instabilities

    Science.gov (United States)

    Biggs, David; Cappelli, Mark

    2016-10-01

    Tunable electromagnetic devices using plasmas are of interest for various applications such as high frequency communications and analog signal processing. At microwave frequencies of tens of gigahertz, low-pressure plasmas must be employed in order to avoid high wave damping from collisions. The drawback of low-pressure plasmas is that their diffusion timescales are long, on the order of hundreds of microseconds. Other mechanisms than diffusion must be employed to achieve fast tuning capabilities of these devices. One candidate mechanism is to use a self-driven plasma instability, which may allow for fast tuning of microwave resonant cavities. In this work, a microwave resonant cavity is studied consisting of a rectangular waveguide with two conducting posts spaced along the propagation direction to form a rectangular cavity. The cavity acts as a band pass filter and transmits microwave signals around its resonant frequency. Plasma may be introduced into the cavity between the conducting posts in order to change the refractive index and thus the resonant and transmission frequency of the device. The location of the plasma and its plasma density are important parameters in determining the resonant frequency, and both parameters are capable of being tuned with plasma instabilities. This work is supported by the Air Force Office of Scientific Research.

  12. Operational status of the Magnum-PSI linear plasma device

    Energy Technology Data Exchange (ETDEWEB)

    Scholten, John, E-mail: j.scholten@differ.nl; Zeijlmans van Emmichoven, P.A.; Eck, H.J.N. van; Smeets, P.H.M.; De Temmerman, G.C.; Brons, S.; Berg, M.A. van den; Meiden, H.J. van der; Pol, M.J. van de; Graswinckel, M.F.; Groen, P.W.C.; Poelman, A.J.; Genuit, J.W.

    2013-10-15

    Highlights: • High heat flux, high density plasmas in a highly accessible linear plasma device. • Plasma exposure of targets of different sizes under selectable plasma beam angles. • Dedicated plasma and surface diagnostics. • Differential vacuum pumping system. -- Abstract: The construction phase of the linear plasma generator Magnum-PSI at the FOM institute DIFFER has been completed and the facility has been officially opened in March 2012. The scientific program to gain more insight in the plasma–wall interactions relevant for ITER and future fusion reactors has started. In Magnum-PSI, targets of a wide range of materials and shapes can be exposed to high particle, high heat flux plasmas (>10{sup 24} ions m{sup −2} s{sup −1}; >10 MW/m{sup 2}). For magnetization of the plasma, oil-cooled electromagnets are temporarily installed to enable pulsed operation until the device is upgraded with a superconducting magnet. The magnets generate a field of up to 1.9 T close to the plasma source for a duration of 6 s. Longer exposure times are available for lower field settings. Plasma characterizations were done with a variety of gases (H, D, He, Ne and Ar) to determine the machine performance and prepare for subsequent scientific experiments. Thomson scattering and optical emission spectroscopy were used to determine the plasma parameters while infrared thermography and target calorimetry were used to determine the power loads to the surface. This paper reports on the status of Magnum-PSI and its diagnostic systems. In addition, an overview of the plasma parameters that can be achieved in the present state will be given.

  13. Effect of nutrition on plasma progesterone levels, metabolic parameters and small follicles development in unstimulated goats reared under constant photoperiod regimen.

    Science.gov (United States)

    Rondina, D; Freitas, V J F; Spinaci, M; Galeati, G

    2005-12-01

    Sixteen local adult goats were submitted for 9 weeks to 2.09 (high group) and 0.54 (low group) x dietary maintenance respectively. During the experimental period, goats were weighed, oestrus was detected and plasma insulin, urea, non-esterified fatty acids and progesterone concentrations were assessed. At the end of the experiment, ovarian small follicles population was studied by histological analysis. Final weight loss in low group was 18.37 +/- 2.02%, whereas weight gain of high group was 13.84 +/- 2.70%. Insulin and urea were lower in low group, while non-esterified fatty acids were significantly higher. A lower number of fasted goats was in oestrus or ovulated and an extended length of oestrus (p goats a significant qualitative alteration of follicle classes involved in the initiation process of primordial pool was found. In this phase, granulosa thickness and oocyte size were the most affected (p 0.05). Collectively, these results indicate that opposite dietary intakes for a medium period induce a composite reproductive response in goats and can regulate the early onset of follicle growth.

  14. STUDY ON THE PRESSURE IN PLASMA ARC

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The axial pressure in plasma arc is measured under different conditions. The effects of the parameters, such as welding current, plasma gas flow rate, electrode setback and arc length, on the pressure in plasma arc are investigated and quantitative analyzed to explain the relationship between the quality of weld and the matching of parameters in plasma arc welding process.

  15. Theoretical Study of a Spherical Plasma Focus

    Science.gov (United States)

    Ay, Yasar

    , electrodynamics, thermodynamics, and radiations emitted from the plasma focus, the discharge current wave form has been used to validate the model. A good agreement has been achieved between theoretical calculation and the experimental measurement of a similar spherical plasma focus device. The snowplow model with the help of the shock wave equations coupled to the circuit equations is used to predict the plasma and shock wave parameters by using the momentum and magnetic force equations. While these equations are used in the phases of the rundown phase I and II, the reflected shock phase with the necessary modification of the magnetic field calculation, and the constant reflected shock front velocity; the radiative phase additionally includes the effect of the radiations emitted from the plasma column (Bremsstrahlung, line and radiative recombination), and the joule heating with the plasma resistance. Neutron yield and the ion properties are calculated in the radiative phase. The parameters for the spherical plasma focus are 8.0 and 14.5 cm inner and outer electrode radii, respectively, 432 muF capacitor bank, 25 kV charging voltage, and 14.5 Torr DT gas pressure. A high discharge current of about 1.5 MA, a high neutron yield of 1.13 x 1013 neutrons, and a high plasma column-ion density of 1.61 x 1024 m --3 are achieved with the given parameters. The developed model is also used to investigate the effect of the gas pressure, discharge voltage, and the molecular mass of the gas on the maximum plasma temperature and pinch start time. It is found that the maximum plasma temperature can be obtained with a relatively shorter pinch start time using a relatively heavier gas with lower gas pressure and higher discharge voltage.

  16. The effect of tobacco smoke on oxytocin concentrations and selected oxidative stress parameters in plasma during pregnancy and post-partum - an experimental model.

    Science.gov (United States)

    Napierala, M; Merritt, T A; Mazela, J; Jablecka, K; Miechowicz, I; Marszalek, A; Florek, E

    2017-02-01

    Tobacco smoking is a serious threat to life and health of society. Among the most vulnerable to the toxic effects of tobacco smoke are foetuses and newborns. The objective of the research was to assess the impact of tobacco smoke exposure on oxytocin levels and biochemical oxidative stress parameters during pregnancy and after birth in an experimental model. In the experiment, exposure to tobacco smoke of gravid and non-gravid rats was monitored. A reliable biomarker of exposure - cotinine - was used in the process and it was determined by means of high-performance liquid chromatography with diode array detection, which ensured high analytical accuracy and precision. Determination of oxytocin was performed by means of enzyme-linked immunosorbent assay. The levels of selected oxidative stress parameters: total protein concentration, uric acid, trolox equivalent antioxidant capacity, protein S-nitrosylation and lipid peroxidation (thiobarbituric acid reactive substances) were measured by spectrophotometric methods. The effect of prenatal and postnatal exposure to tobacco smoke was a lower medium body mass of rat foetuses and pups. Oxidative stress during pregnancy, additionally intensified by tobacco smoke exposure, led to adaptive changes in properties of plasmatic antioxidant barriers. Moreover, the disturbance of oxidoreductive balance by tobacco smoke affects oxytocin fluctuations, what was observed in this study during lactation period. Therefore, women who smoke may breastfeed their children less frequently and for a shorter period.

  17. A Sensitivity Analysis of SOLPS Plasma Detachment

    Science.gov (United States)

    Green, D. L.; Canik, J. M.; Eldon, D.; Meneghini, O.; AToM SciDAC Collaboration

    2016-10-01

    Predicting the scrape off layer plasma conditions required for the ITER plasma to achieve detachment is an important issue when considering divertor heat load management options that are compatible with desired core plasma operational scenarios. Given the complexity of the scrape off layer, such predictions often rely on an integrated model of plasma transport with many free parameters. However, the sensitivity of any given prediction to the choices made by the modeler is often overlooked due to the logistical difficulties in completing such a study. Here we utilize an OMFIT workflow to enable a sensitivity analysis of the midplane density at which detachment occurs within the SOLPS model. The workflow leverages the TaskFarmer technology developed at NERSC to launch many instances of the SOLPS integrated model in parallel to probe the high dimensional parameter space of SOLPS inputs. We examine both predictive and interpretive models where the plasma diffusion coefficients are chosen to match an empirical scaling for divertor heat flux width or experimental profiles respectively. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility, and is supported under Contracts DE-AC02-05CH11231, DE-AC05-00OR22725 and DE-SC0012656.

  18. Activated Charcoal Hemoperfusion in the Treatment of Experimental Amitriptyline Poisoning in Pigs - The Effect on Amitriptyline Plasma Concentration and Hemodynamic Parameters

    DEFF Research Database (Denmark)

    Jansen, Tejs; Petersen, Henrik; Malskaer, Cecilie M;

    2016-01-01

    Coated activated charcoal hemoperfusion (CAC-HP) is a well-known treatment modality. Case reports have revealed conflicting results about the efficacy of CAC-HP in the treatment of amitriptyline (AT) poisoning, and no randomised clinical trials have been identified in the literature. This study...... aimed at quantifying the efficacy of modern CAC-HP as an adjunctive treatment of AT intoxication compared to standard care alone. Fourteen female Danish landrace pigs were randomized to either standard care or standard care plus 4 hr of CAC-HP. The pigs were anaesthetized and vital parameters were...... continuously recorded. Amitriptyline infusion (7.5 mg/kg) was completed in 20 min. Thirty minutes following AT infusion, activated charcoal was instilled orally in both groups. In the intervention group, CAC-HP was initiated 60 min. after AT infusion. Blood and urine samples were collected as were vital...

  19. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein

    2017-01-01

    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  20. Accurate determination of optical bandgap and lattice parameters of Zn{sub 1-x}Mg{sub x}O epitaxial films (0{<=}x{<=}0.3) grown by plasma-assisted molecular beam epitaxy on a-plane sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Laumer, Bernhard [Walter Schottky Institut and Physics Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching (Germany); I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany); Schuster, Fabian; Stutzmann, Martin [Walter Schottky Institut and Physics Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching (Germany); Bergmaier, Andreas; Dollinger, Guenther [Universitaet der Bundeswehr Muenchen, Fakultaet fuer Luft- und Raumfahrttechnik, Werner-Heisenberg-Weg 39, 85577 Neubiberg (Germany); Eickhoff, Martin [I. Physikalisches Institut, Justus-Liebig-Universitaet Giessen, Heinrich-Buff-Ring 16, 35392 Giessen (Germany)

    2013-06-21

    Zn{sub 1-x}Mg{sub x}O epitaxial films with Mg concentrations 0{<=}x{<=}0.3 were grown by plasma-assisted molecular beam epitaxy on a-plane sapphire substrates. Precise determination of the Mg concentration x was performed by elastic recoil detection analysis. The bandgap energy was extracted from absorption measurements with high accuracy taking electron-hole interaction and exciton-phonon complexes into account. From these results a linear relationship between bandgap energy and Mg concentration is established for x{<=}0.3. Due to alloy disorder, the increase of the photoluminescence emission energy with Mg concentration is less pronounced. An analysis of the lattice parameters reveals that the epitaxial films grow biaxially strained on a-plane sapphire.

  1. 基于GDT的聚变裂变混合堆堆芯参数初步设计研究%Preliminary design of core plasma parameters for the fusion-fission hybrid reactor based on GDT

    Institute of Scientific and Technical Information of China (English)

    陈德鸿; 杜红飞; 蒋洁琼; 汪晖; 王福琼; 陈一平; 吴宜灿; FDS团队

    2012-01-01

    Based on the recent experiment progress of Gas Dynamic Trap (GDT), a core plasma physics conceptual design for driving fission blanket was proposed The 0-D physical model was built and the core plasma parameters with 50 MW fusion power were preliminarily designed The reliability of the physical model and design was demonstrated by comparison between the calculation and the experiment results.%基于Gas Dynamic Trap(GDT)装置的实验进展,提出了用于驱动聚变裂变混合堆包层的聚变堆芯参数设计.基于零维堆芯物理模型,计算分析给出了一套聚变功率为50 MW的初步堆芯参数方案.利用GDT装置的实验结果对该物理模型进行计算对比校验,显示该物理模型和设计参数的可靠性.

  2. Effects of exposure to three environmental chemicals on the selected biochemical parameters of the blood plasma of rainbow trout, Oncorhynchus mykiss (Walbaum

    Directory of Open Access Journals (Sweden)

    Řehulka Jiří

    2016-03-01

    Full Text Available Rainbow trout Oncorhynchus mykiss at a weight of 115 ± 24 g (mean ± SD were experimentally injected with di(2-ethylhexylphthalate (DEHP, 2,3,7,8-tetrachlorodibenzo-p-dioxine (TCDD and gamma isomer of hexachlorocyclohexane (γ-HCH to evaluate nitrogen metabolism (total protein [TP], blood urea nitrogen, uric acid [UA], creatinine, carbohydrate metabolism (glucose, mineral metabolism (inorganic phosphate[P], total calcium [Cat], and catalytic activity of enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], lactate dehydrogenase [LD]. After 21 days, the tested xenobiotics, administered by the intraperitoneally route, caused the following effect: in comparison with negative controls, fish injected with DEHP at concentrations of 200 or 50 mg kg-1 of body weight were found to have a higher level of P and lower level of Cat and decreased catalytic concentrations of ALT, AST, ALP and LD in the plasma of the peripheral blood. A higher level of TP and P and a decreased catalytic concentration of ALT were found when TCDD was administered at a dose of 2 μg kg-1. A decrease in the catalytic concentrations of ALT and ALP occurred in fish injected with γ-HCH in a dose of 50 mg kg-1. UA and P levels were decreased in fish injected with γ-HCH in a dose of 5 mg kg-1. DEHP and TCDD caused neutrophilic leucocytosis with a marked left shift. Both concentrations of γ-HCH led to an increase in polychromatophilic erythrocytes. The frequency of micronuclei varied in all experimental groups, including the controls, ranging between 0.8 and 2.1 ‰. Histological examination in fish injected with DEHP at a concentration of 200 mg kg-1 revealed eosinophilic droplets in the epithelium of renal tubules and histological examination in fish injected with γ-HCH at a higher concentration revealed an increased activation of sinusoidal cells in the liver, a fibrous thickening of bile duct walls, bile duct hyperplasia and a

  3. A prospective double-blind randomized placebo-controlled study of the effect of saffron (Crocus sativus Linn.) on semen parameters and seminal plasma antioxidant capacity in infertile men with idiopathic oligoasthenoteratozoospermia.

    Science.gov (United States)

    Safarinejad, Mohammad Reza; Shafiei, Nayyer; Safarinejad, Shiva

    2011-04-01

    Male factor infertility is a multifactorial disorder that affects a significant percentage of infertile couples; however, many of them remained untreated. In recent years, considerable numbers of infertile men have sought 'herbal remedies' as an effective treatment. Among 'herbal remedies', saffron is recommended for male infertility in our community. The effect of saffron was evaluated compared with placebo for the treatment of idiopathic male factor infertility. The study included 260 infertile men with idiopathic oligoasthenoteratozoospermia (OAT) who were randomized to saffron 60 mg/day (130, group 1) or a similar regimen of placebo (130, group 2) for 26 weeks. The two groups were compared for changes in semen parameters and total seminal plasma antioxidant capacity. Saffron administration did not result in beneficial effects. At the end of the study no statistically significant improvements were observed in either group in any of the studied semen parameters (sperm density, morphology and motility) (all p = 0.1). At the end of the trial, patients in group 1 had a mean motility of 25.7 ± 2.4%, which was not statistically different from the mean of 24.9 ± 2.8% in the placebo group (p = 0.1). Normal sperm morphology was 18.7 ± 4.7% and 18.4 ± 4.3%, in groups 1 and 2, respectively (p = 0.1). Patients treated with saffron and placebo had a mean sperm density of 20.5 ± 4.6% and 21.4 ± 4.6% per mL, respectively (p = 0.1). Saffron administration did not improve total seminal plasma antioxidant capacity, compared with baseline (p = 0.1) and placebo subjects (p = 0.1). Based on Pearson correlations, each semen parameter did not correlate significantly with treatment duration, including sperm density (r = 0.146, p = 0.13), percent of motile sperm (r = 0.145, p = 0.15) and percent of sperm with normal morphology (r = 0.125, p = 0.30). Saffron does not statistically significantly improve semen parameters in infertile men with idiopathic OAT. If medical

  4. Laminar Plasma Dynamos

    CERN Document Server

    Wang, Z; Barnes, C W; Barnes, D C; Wang, Zhehui; Pariev, Vladimir I.; Barnes, Cris W.; Barnes, Daniel C.

    2002-01-01

    A new kind of dynamo utilizing flowing laboratory plasmas has been identified. Conversion of plasma kinetic energy to magnetic energy is verified numerically by kinematic dynamo simulations for magnetic Reynolds numbers above 210. As opposed to intrinsically-turbulent liquid-sodium dynamos, the proposed plasma dynamos correspond to laminar flow topology. Modest plasma parameters, 1-20 eV temperatures, 10^{19}-10^{20} m^{-3} densities in 0.3-1.0 m scale-lengths driven by velocities on the order of the Alfven Critical Ionization Velocity (CIV), self-consistently satisfy the conditions needed for the magnetic field amplication. Growth rates for the plasma dynamos are obtained numerically with different geometry and magnetic Reynolds numbers. Magnetic-field-free coaxial plasma guns can be used to sustain the plasma flow and the dynamo.

  5. Development of plasma cathode electron guns

    Science.gov (United States)

    Oks, Efim M.; Schanin, Peter M.

    1999-05-01

    The status of experimental research and ongoing development of plasma cathode electron guns in recent years is reviewed, including some novel upgrades and applications to various technological fields. The attractiveness of this kind of e-gun is due to its capability of creating high current, broad or focused beams, both in pulsed and steady-state modes of operation. An important characteristic of the plasma cathode electron gun is the absence of a thermionic cathode, a feature which leads to long lifetime and reliable operation even in the presence of aggressive background gas media and at fore-vacuum gas pressure ranges such as achieved by mechanical pumps. Depending on the required beam parameters, different kinds of plasma discharge systems can be used in plasma cathode electron guns, such as vacuum arcs, constricted gaseous arcs, hollow cathode glows, and two kinds of discharges in crossed E×B fields: Penning and magnetron. At the present time, plasma cathode electron guns provide beams with transverse dimension from fractional millimeter up to about one meter, beam current from microamperes to kiloamperes, beam current density up to about 100 A/cm2, pulse duration from nanoseconds to dc, and electron energy from several keV to hundreds of keV. Applications include electron beam melting and welding, surface treatment, plasma chemistry, radiation technologies, laser pumping, microwave generation, and more.

  6. Design Considerations in Capacitively Coupled Plasmas

    Science.gov (United States)

    Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

    2015-11-01

    Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

  7. Physics of Tokamak Plasma Start-up

    Science.gov (United States)

    Mueller, Dennis

    2012-10-01

    This tutorial describes and reviews the state-of-art in tokamak plasma start-up and its importance to next step devices such as ITER, a Fusion Nuclear Science Facility and a Tokamak/ST demo. Tokamak plasma start-up includes breakdown of the initial gas, ramp-up of the plasma current to its final value and the control of plasma parameters during those phases. Tokamaks rely on an inductive component, typically a central solenoid, which has enabled attainment of high performance levels that has enabled the construction of the ITER device. Optimizing the inductive start-up phase continues to be an area of active research, especially in regards to achieving ITER scenarios. A new generation of superconducting tokamaks, EAST and KSTAR, experiments on DIII-D and operation with JET's ITER-like wall are contributing towards this effort. Inductive start-up relies on transformer action to generate a toroidal loop voltage and successful start-up is determined by gas breakdown, avalanche physics and plasma-wall interaction. The goal of achieving steady-sate tokamak operation has motivated interest in other methods for start-up that do not rely on the central solenoid. These include Coaxial Helicity Injection, outer poloidal field coil start-up, and point source helicity injection, which have achieved 200, 150 and 100 kA respectively of toroidal current on closed flux surfaces. Other methods including merging reconnection startup and Electron Bernstein Wave (EBW) plasma start-up are being studied on various devices. EBW start-up generates a directed electron channel due to wave particle interaction physics while the other methods mentioned rely on magnetic helicity injection and magnetic reconnection which are being modeled and understood using NIMROD code simulations.

  8. Plasma antioxidative stress parameters levels in patients with early and delayed Parkinson's disease%早发型与晚发型帕金森病患者血浆抗氧化应激指标分析

    Institute of Scientific and Technical Information of China (English)

    周红; 袁永胜; 张克忠; 佟晴; 戚志强; 张姝

    2014-01-01

    目的:研究早发型与晚发型帕金森病(Parkinson's disease ,PD )患者血浆抗氧化应激指标的差异性,并探讨其与临床特点的相关性。方法入选原发性PD患者62例(PD组),PD组根据发病年龄,分为早发型PD 组35例和晚发型PD组27例;另入选健康体检者20例(对照组)。使用 ELISA 检测血浆谷胱甘肽(GSH )、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GPX)水平,比较各组间差异,并对发病年龄与血浆抗氧化应激指标进行相关性分析。结果 PD组患者血浆GSH[(18.42±14.64)μmol/L vs (79.32±64.48)μmol/L]、CAT[(160.87±10.49)kU/L vs (171.11±4.00)kU/L]、SOD[(93.58±24.17)kU/L vs (122.33±22.83)kU/L]水平明显低于对照组(P<0.01);早发型PD组患者血浆GSH水平明显高于晚发型 PD组(P<0.05)。发病年龄与血浆GSH呈负相关(P<0.01)。结论 PD患者血浆GSH、CAT、SOD水平异常下降,提示PD患者存在抗氧化能力缺陷;早发型与晚发型PD患者血浆GS H水平具有显著差异性,发病年龄愈晚,血浆GS H水平愈低。%Objective To study the difference in plasma antioxidative stress parameters levels in patients with early and delayed Parkinson's disease (PD) and its relation with the clinical features of PD .Methods Sixty-two primary PD patients served as a PD group which was further divided into early PD group (n=35) and delayed PD group (n=27) ,and 20 subjects undergoing physical examination served as a control group .Their plasma GSH ,CAT ,SOD and GPX levels were meas-ured by ELISA .The difference in different groups was compared and the relation between disease onset age and plasma antioxidative parameters levels was analyzed .Results The plasma GSH , CAT and SOD levels were significantly lower in PD group than in control group (18 .42 ± 14 .64μmol/L vs79.32±64.48 μmol/L,160.87±10

  9. Correlation between Semen PH Value and Semen Parameters or Biochemical Analyses Results of Seminal Plasma%精液pH值与精液参数及精浆生化的相关性研究

    Institute of Scientific and Technical Information of China (English)

    陈帅垒; 王祖龙

    2012-01-01

    目的 探讨精液pH值与精液参数及精浆生化之间的相关性,明确精液pH值在精液质量检测中所具有的价值.方法 收集河南省中医院中西医结合生殖中心2009年1月-2011年3月资料完整的男性不育症患者精液分析及精浆生化记录616份,建立Excel数据库,采用SPSS 16.0统计软件,对精液pH值与精液参数及精浆生化进行相关性分析.结果 精液pH值和受试者精浆弹性蛋白酶、精液A级精子百分率、前向运动精子百分率及存活精子百分率呈正相关性(P<0.05);与精浆酸性磷酸酶、精浆锌呈负相关性(P<0.05);与年龄、精浆果糖、精浆α-糖苷酶、精液白细胞、精液量、液化时间、精子浓度、正常形态精子数量无明显相关性(P>0.05).结论 精液pH值和精液参数及精浆生化的多项数值均具有相关性,进一步研究精液pH值的影响,对于男性不育症患者的诊疗具有重要意义.%Objective To study the correlation between semen pH value and semen parameters and biochemical analyses results of seminal plasma, and evaluate the value of semen pH in the semen quality test. Methods The semen and biochemical analyses results of 616 male infertility patients in our hospital from January 2009 to March 2011 were collected and analyzed by u-sing SPSS statistical software to evaluate the correlation between semen pH value and semen parameters and biochemical analyses results of seminal plasma. Results The semen PH value was positively correlated to the seminal plasma elastase, rate of grade A sperm,rate of rapid progression motility sperm and sperm viability (P 0. 05) . Conclusion The semen PH value is closely correlated to the semen parameters and biochemical analyses results of seminal plasma. The further study on the influence of semen PH value should improve the diagnosis and treatment of male infertility patients.

  10. Parameter Optimization for Enhancement of Ethanol Yield by Atmospheric Pressure DBD-Treated Saccharomyces cerevisiae

    Science.gov (United States)

    Dong, Xiaoyu; Yuan, Yulian; Tang, Qian; Dou, Shaohua; Di, Lanbo; Zhang, Xiuling

    2014-01-01

    In this study, Saccharomyces cerevisiae (S. cerevisiae) was exposed to dielectric barrier discharge plasma (DBD) to improve its ethanol production capacity during fermentation. Response surface methodology (RSM) was used to optimize the discharge-associated parameters of DBD for the purpose of maximizing the ethanol yield achieved by DBD-treated S. cerevisiae. According to single factor experiments, a mathematical model was established using Box-Behnken central composite experiment design, with plasma exposure time, power supply voltage, and exposed-sample volume as impact factors and ethanol yield as the response. This was followed by response surface analysis. Optimal experimental parameters for plasma discharge-induced enhancement in ethanol yield were plasma exposure time of 1 min, power voltage of 26 V, and an exposed sample volume of 9 mL. Under these conditions, the resulting yield of ethanol was 0.48 g/g, representing an increase of 33% over control.

  11. Theoretical study of plasma confinement by magnetic multicusp field

    Science.gov (United States)

    Khalzov, Ivan; Forest, Cary

    2014-10-01

    Plasma confinement in a magnetic multicusp field is studied numerically using both collisional particle-in-cell and isothermal two-fluid MHD codes and tested against the empirical model. The simulation domain is two-dimensional, periodic in one direction and bounded by absorbing boundaries with multicups field in other direction. First, we study the dependence of plasma loss width on plasma parameters and field strength and compare the results with the well-known empirical formula w = 2√{ρeρi } (two hybrid gyro-radius). Our results show that the loss width has the same scaling with magnetic field w ~ 1 / B , but dependence on other plasma parameters does not agree with this formula. Second, we study the plasma flow drive in the cusp region due to electric field applied by discrete electrodes. The electrode positions are optimized for achieving the highest plasma flow. Comparison with available experimental data from Madison Plasma Dynamo Experiment (MPDX) is made. The work is supported by NSF and DoE.

  12. B2-EIRENE simulation of plasma and neutrals in MAGNUM-PSI

    Science.gov (United States)

    Baeva, M.; Goedheer, W. J.; Lopes Cardozo, N. J.; Reiter, D.

    2007-06-01

    A self-consistent description (performed by means of the B2-EIRENE code package) of a hydrogen plasma including electrons, ions and neutral background gas is used to investigate the processes and plasma behavior under conditions expected in MAGNUM-PSI. Several cases varying in gas-puffing, pumping rate, and plasma parameters are simulated. In all cases a detached plasma regime is achieved. The plasma density increases considerably for higher neutral pressures up to (1-5) × 1014 cm-3. The particle flux to the target is ∼1024 m-2 s-1 and the plasma heat flux is ∼10 MW m-2. The latter is significantly reduced in front of the target due to electron and ion cooling resulting from ionization and dissociation of H2 molecules, and charge exchange/elastic collisions. Under the conditions of investigation, the losses due to molecule activated recombination are dominant compared with 3-body recombination of atomic ions.

  13. Plasma diagnostics in plasma processing for nanotechnology and nanolevel chemistry

    Directory of Open Access Journals (Sweden)

    Hiroshi Akatsuka

    2004-01-01

    Full Text Available The author reviews the role of various plasma diagnostics in plasma processing for nanotechnology, and points out some essential methods of spectroscopic methods to diagnose plasmas for nanoprocessing. Two experimental examples are discussed between the characteristics of nanomaterials and plasma parameters. One is measurement of rotation temperature in processing of carbon nanotube. The other is that of vibrational temperature in surface nitriding of titanium by nitrogen plasma processing. We summarize what to measure and how to measure them from the technical viewpoint of plasma diagnostics.

  14. Gas Permeability of Porous Plasma-Sprayed Coatings

    Science.gov (United States)

    Wittmann-Ténèze, K.; Caron, N.; Alexandre, S.

    2008-12-01

    For different applications, such as solid oxide fuel cells, there is an interest in understanding the relationship between the microstructure and the gas permeability of plasma-sprayed coatings. Nevertheless, plasma spraying processes allow to elaborate coatings with singular microstructures, depending strongly on the initial material and plasma operating conditions. And so, the evolution of permeability is not directly linked to the porosity. In this work, coatings were manufactured using different initial feedstock and spray parameters to obtain various microporous structures. Measurements of their permeation with the pressure drop method and their open porosity just as the observation of the morphology and the structure by optical microscopy were achieved. The different data show that the evolution of the gas permeability with the open porosity follows the Kozeny-Carman equation. This result correlated with the microstructural observation highlights the relationship between the permeability and the physical properties of porous plasma-sprayed layers.

  15. Laser-plasma-based linear collider using hollow plasma channels

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, C.B., E-mail: CBSchroeder@lbl.gov; Benedetti, C.; Esarey, E.; Leemans, W.P.

    2016-09-01

    A linear electron–positron collider based on laser-plasma accelerators using hollow plasma channels is considered. Laser propagation and energy depletion in the hollow channel is discussed, as well as the overall efficiency of the laser-plasma accelerator. Example parameters are presented for a 1-TeV and 3-TeV center-of-mass collider based on laser-plasma accelerators.

  16. Theory of gas discharge plasma

    CERN Document Server

    Smirnov, Boris M

    2015-01-01

    This book presents the theory of gas discharge plasmas in a didactical way. It explains the processes in gas discharge plasmas. A gas discharge plasma is an ionized gas which is supported by an external electric field. Therefore its parameters are determined by processes in it. The properties of a gas discharge plasma depend on its gas component, types of external fields, their geometry and regimes of gas discharge. Fundamentals of a gas discharge plasma include elementary, radiative and transport processes which are included in its kinetics influence. They are represented in this book together with the analysis of simple gas discharges. These general principles are applied to stationary gas discharge plasmas of helium and argon. The analysis of such plasmas under certain conditions is theoretically determined by numerical plasma parameters for given regimes and conditions.

  17. Plasma current start-up experiments using outboard- and top-launch lower hybrid wave on the TST-2 spherical tokamak

    Science.gov (United States)

    Shinya, T.; Takase, Y.; Yajima, S.; Moeller, C.; Yamazaki, H.; Tsujii, N.; Yoshida, Y.; Ejiri, A.; Togashi, H.; Toida, K.; Furui, H.; Homma, H.; Nakamura, K.; Roidl, B.; Sonehara, M.; Takahashi, W.; Takeuchi, T.

    2017-03-01

    Non-inductive plasma current start-up experiments were performed using the lower hybrid wave (LHW) on the TST-2 spherical tokamak. The density limit, observed in previous experiments using the outboard-launch antenna, disappeared after changing the plasma condition in the scrape-off layer, and the plasma current reached about 20 kA. In order to improve the LHW power deposition in the plasma core through an up-shift of the parallel wavenumber during the first pass through the plasma, a new top-launch antenna was designed, fabricated and installed. The plasma current ramp-up to 12 kA was achieved using the top-launch antenna alone in a preliminary experiment. Ray-tracing calculations using the measured plasma parameters showed a large up-shift during the first pass, satisfying the strong electron Landau damping condition in the plasma core.

  18. Plasma turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

    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.

  19. Recent results on ITER plasma equilibrium diagnostics and identification

    Energy Technology Data Exchange (ETDEWEB)

    Albanese, R.; Coccorese, E.; Morabito, F.C.; Pironti, A.; Versaci, M. [Associazione CREATE/ENEA/EURATOM - DIMET, Loc. Feo di Vito, Reggio Calabria (Italy); Mc Carthy, P.J. [Cork Univ. College (Ireland). Physics Dept.

    1998-07-01

    The most recent results achieved by our work-group on the plasma shape and position identification problem as well as on the interpretation of magnetic diagnostics are presented. The proposed test cases are related to the most recent configuration of sensors and geometry specification available from ITER. One of the aims of the work is also to give some design directions about the problem of optimal selection of the diagnostics for control parameters. (author)

  20. Plasma processing of superconducting radio frequency cavities

    Science.gov (United States)

    Upadhyay, Janardan

    The development of plasma processing technology of superconducting radio frequency (SRF) cavities not only provides a chemical free and less expensive processing method, but also opens up the possibility for controlled modification of the inner surfaces of the cavity for better superconducting properties. The research was focused on the transition of plasma etching from two dimensional flat surfaces to inner surfaces of three dimensional (3D) structures. The results could be applicable to a variety of inner surfaces of 3D structures other than SRF cavities. Understanding the Ar/Cl2 plasma etching mechanism is crucial for achieving the desired modification of Nb SRF cavities. In the process of developing plasma etching technology, an apparatus was built and a method was developed to plasma etch a single cell Pill Box cavity. The plasma characterization was done with the help of optical emission spectroscopy. The Nb etch rate at various points of this cavity was measured before processing the SRF cavity. Cylindrical ring-type samples of Nb placed on the inner surface of the outer wall were used to measure the dependence of the process parameters on plasma etching. The measured etch rate dependence on the pressure, rf power, dc bias, temperature, Cl2 concentration and diameter of the inner electrode was determined. The etch rate mechanism was studied by varying the temperature of the outer wall, the dc bias on the inner electrode and gas conditions. In a coaxial plasma reactor, uniform plasma etching along the cylindrical structure is a challenging task due to depletion of the active radicals along the gas flow direction. The dependence of etch rate uniformity along the cylindrical axis was determined as a function of process parameters. The formation of dc self-biases due to surface area asymmetry in this type of plasma and its variation on the pressure, rf power and gas composition was measured. Enhancing the surface area of the inner electrode to reduce the

  1. 禁欲时间对精子参数及精浆生化指标的影响%Effects of sexual abstinence on sperm parameters and seminal plasma biochemical indicators

    Institute of Scientific and Technical Information of China (English)

    李付彪; 张明; 封建军; 刘祥印; 刘睿智

    2008-01-01

    Objective To study the influences of the length of sexual abstinence on sperm parameters and seminal plasma biochemical indicator.Methods Sperm concentration and motility were detected by computer assisted sperm analysis(CASA).The sperm morphology was analyzed using semiautomatic sperm morphology analyzer.Seminal plasma fructose concentration,neutral a-glycosidase,zinc,and acid phosphates concentration were measured by spectrophotometer.Improved DTNB was conducted for detection of the content of seminal plasma novain.Prostatespecific antigen(PSA)was measured with commercial kit.Three groups were defined according to the days of sexual abstinence:G1(1-3 days),G2(4-5 days)and G3(>6 days).Results Sperm concentration of G2 was significantly higher than that of G1(P<0.01),and of G3 than that of G1 and G2(P<0.01).Sperm motility and per centage of morphologically normal sperm of G3 were significantly lower than that of G1(P<0.01).Seminal plasma fructose concentration of G3 was significantly lower than that of G1 and G2(P<0.01,P<0.05).Seminal plasma neutral a-glycosidase,carnutine,zinc concentration of G3 was significantly higher than that of G1 and G2(P<0.01,P<0.05).Conclusion The length of sexual abstinence can influence sperm parameters and seminal plasma biochemical indicator.%目的 探讨禁欲时间对精子参数及精浆生化指标的影响.方法 采用精子形态检测系统下人工修正方法进行精子形态分析.采用精子质量检测系统进行精子密度、活力分析.精浆果糖含量、中性a糖苷酶、精浆锌、酸性磷酸酶等采用分光光度比色法测定.采用DTNB改进法检测精浆肉毒碱含量.前列腺特异性抗原(PSA)采用试剂盒进行检测.根据禁欲时间分为3组:G1(禁欲1~3d)组、G2(禁欲4~5d)组和G3(禁欲6d以上)组.结果G2组精子密度[(70.64±63.79)×106]显著高于G1组[(57.40±45.36)×106,P<0.01],G3组精子密度[(77.00±65.43)×106]显著高于G1组[(57.40±45.36)×106

  2. Parameter Estimation

    DEFF Research Database (Denmark)

    2011-01-01

    of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set......In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  3. Influence of discharge parameters on blow-by in a coaxial plasma gun%放电参数对同轴枪中等离子体团的分离的影响

    Institute of Scientific and Technical Information of China (English)

    张俊龙; 杨亮; 闫慧杰; 滑跃; 任春生

    2015-01-01

    同轴枪中的等离子体团的分离现象主要是由同轴枪内磁场的梯度造成的电流层倾斜而引起的一个增强反馈过程导致的,这种分离现象越来越成为限制同轴枪有效使用的一个不利因素。在实验上研究放电参数对等离子体团的分离的影响,对理论研究和实际应用都具有重要意义。在实验中发现,利用光电倍增管可以直接观察到等离子体团的分离程度,由此可以研究放电参数对等离子体团的分离的影响。本实验主要研究电容充电电压、电容、放电气压这三个参数对分离现象的影响。实验发现,分离程度随着电容以及其充电电压的增大而增强,随着气压的增大而减弱。实验结果基于雪犁模型进行分析,电容以及电容充电电压的增大使放电电流增强使磁场梯度增大而导致电流层的倾斜程度增加,而使等离子体团的分离程度变严重,相反,气压的增加使需要加速更多粒子而导致电流层的倾斜程度减弱,而使等离子体团分离程度减弱。分析认为,通过控制在加速过程中影响电流层倾斜程度的因素可控制共轴枪中等离子体团的分离程度。%The blow-by which occurs in a coaxial plasma gun is the result of reinforcing feedback caused by the gradient of magnetic field and the component of axial current due to the canting of current sheath. The blow-by has become a serious negative effect which limits the effective use of the coaxial plasma gun, so it is necessary to study by experiment the parameters that influence the degree of blow-by. This will not only contribute to the study of the theory and mode about blow-by but also give advices to the weakening or eliminating blow-by by choosing suitable parameters in engineering field. The degree of blow-by can be observed directly by photomultiplier, and the influence of voltage of capacitance, capacitance, and the pressure of gas on blow-by have

  4. 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

  5. Neutron yield and Lawson criterion for plasma with inertial electrostatic confinement

    Science.gov (United States)

    Gus'kov, S. Yu; Kurilenkov, Yu K.

    2016-11-01

    The physics of plasma formation is discussed in the systems with inertial electrostatic confinement (IEC) during the convergent to the axis of cylindrical geometry of the ion flow accelerated periodically in the field of virtual cathode, which is formed by the injected electrons. The ranges of plasma parameters and the resulting neutron yield are determined for different modes of ion flux formation. The requirements are formulated to the technical parameters of the system with IEC to create both a powerful neutron source with a rate of generation exceeding 1010-1012 particles/s and to achieve a positive energy output (analogue of Lawson criterion).

  6. Durable Nanolayer Graft Polymerization of Functional Finishes Using Atmospheric Plasma

    Science.gov (United States)

    Mazloumpour, Maryam

    Various applications of atmospheric pressure plasma were investigated in conjunction with different chemistries on nonwoven materials including spunbond polyester (PET) and spunbod polypropylene for fuel separation and antimicrobial functionalities. Hydrophobic/Oleophobic properties were conferred on nonwoven polyester (PET) via plasma-induced graft polymerization of different hydrophobic non-C8 perfluorocarbon chemistry including perfluorohexylethylmethacrylate, perfluorohexylethylacrylate, allylpentafluorobenzene, pentafluorostyrene, or 1,3-divinyltetramethyldisiloxane in the vapor form using both in-situ and down-stream plasma configurations. Different nanolayers of the grafted polymer were furnished on nonwovens to generate surfaces with different level of wettabilities for medical applications and water/fuel separation. The effect of various hydrophobic chemistry, different plasma conditions, and plasma device parameters including plasma power and plasma exposure time were studied and the performance was characterized by measuring the contact angle and the wettability rating against liquids with broad range of surface tensions. Vapor deposition of 2-(perfluorohexyl)ethyl methacrylate and pentafluorostyrene on nonwoven PET followed by plasma-induced graft polymerization was investigated for possible use in water/fuel separation. Different nanolayer thicknesses (80-180nm) of the grafted polymer were achieved to generate surfaces with different wettabilities for water/fuel separation of different fuel compositions. The effect of different plasma conditions and device parameters including the flow rate of monomers, power of the device, and time of plasma exposure on the separation of different fuels was studied and characterized by measuring the surface energy of the treated substrates. The surface chemistry and morphology of the treated samples were characterized using XPS, SEM and TOF-SIMS techniques which confirmed the grafting of monomer onto the substrate

  7. Optimization of atmospheric air plasma for degradation of organic dyes in wastewater.

    Science.gov (United States)

    Sarangapani, Chaitanya; Dixit, Y; Milosavljevic, Vladimir; Bourke, Paula; Sullivan, Carl; Cullen, P J

    2017-01-01

    This study optimises the degradation of a cocktail of the dyes methyl orange and bromothymol blue by atmospheric air plasma. Response surface methodology (RSM) was employed to investigate the efficacy of the plasma process parameters on degradation efficiency. A Box-Behnken design (BBD) was employed to optimise the degradation of dyes by air plasma discharge. A second order polynomial equation was proposed to predict process efficiency. It was observed that the predicted values are significant (p degradation, pH value and ozone concentration, respectively. The analysis of variance results showed that the coefficients of the polynomials for the percentage degradation and ozone concentration responses indicated positive linear effects (p degradation efficiencies are achieved with an increase in treatment duration. This study showed that a BBD model and RSM could be employed to optimize the colour degradation parameters of non-thermal plasma treated model dyes while minimising the number of experiments required.

  8. Diagnostics of Nanodusty Plasma

    Science.gov (United States)

    Greiner, Franko; Groth, Sebastian; Tadsen, Bejamin; Piel, Alexander

    2015-11-01

    The diagnostic of nanodusty plasmas, i.e. plasmas including nano-sized dust particles, is a challenging task. For both, the diagnostic of the nanodusty plasma itself, and the in-situ diagnostic of the nanoparticles, no standard diagnostic exist. Nanodust particle size and density can be estimated using light scattering techniques, namely kinetic Mie ellipsometry and extinction measurements. The charge of the nanoparticles can be estimated from the analysis of dust density waves (DDW). Parameters like the electron density, which give information about the plasma itself, may be deduced from the DDW analysis. We present detailed investigations on nanodust in a reactive Argon-Acetylene plasma created in an rf-driven parallel plate reactor at low pressure using the above mentioned portfolio of diagnostic. Funded by DFG under contract SFB TR-24/A2.

  9. Modeling of transient dust events in fusion edge plasmas with DUSTT-UEDGE code

    Science.gov (United States)

    Smirnov, R. D.; Krasheninnikov, S. I.; Pigarov, A. Yu.; Rognlien, T. D.

    2016-10-01

    It is well known that dust can be produced in fusion devices due to various processes involving structural damage of plasma exposed materials. Recent computational and experimental studies have demonstrated that dust production and associated with it plasma contamination can present serious challenges in achieving sustained fusion reaction in future fusion devices, such as ITER. To analyze the impact, which dust can have on performance of fusion plasmas, modeling of coupled dust and plasma transport with DUSTT-UEDGE code is used by the authors. In past, only steady-state computational studies, presuming continuous source of dust influx, were performed due to iterative nature of DUSTT-UEDGE code coupling. However, experimental observations demonstrate that intermittent injection of large quantities of dust, often associated with transient plasma events, may severely impact fusion plasma conditions and even lead to discharge termination. In this work we report on progress in coupling of DUSTT-UEDGE codes in time-dependent regime, which allows modeling of transient dust-plasma transport processes. The methodology and details of the time-dependent code coupling, as well as examples of simulations of transient dust-plasma transport phenomena will be presented. These include time-dependent modeling of impact of short out-bursts of different quantities of tungsten dust in ITER divertor on the edge plasma parameters. The plasma response to the out-bursts with various duration, location, and ejected dust sizes will be analyzed.

  10. Carbon dioxide dissociation in non-thermal radiofrequency and microwave plasma

    Science.gov (United States)

    Huang, Qiang; Zhang, Diyu; Wang, Dongping; Liu, Kezhao; Kleyn, Aart W.

    2017-07-01

    We have studied carbon dioxide dissociation in inductively coupled radiofrequency plasma and microwave plasma at low gas pressure. Both systems exhibit features of non-thermal plasma. The highest energy efficiency observed is 59.3% (2.13 mmol kJ-1), exceeding the maximum value of about 45% in case of thermodynamic equilibrium, and a maximum conversion of 80.6% is achieved. Different discharge conditions, such as the source frequency, discharge gas pressure and the addition of argon, will affect the plasma parameters, especially the electron energy distribution. This plays a great role in the energy transfer from non-thermal plasma to the molecular dissociation reaction channel by enabling the ladder climbing of the carbon dioxide molecular vibration. The results indicate the importance of ladder climbing.

  11. Boltzmann equation analysis of electrons swarm parameters and properties of excited particle number densities in Xe/Ne plasmas. Laser absorption effect; Xe/Ne plasma chudenshi yuso keisu narabi ni reiki ryushisu mitsudo tokusei no Boltzmann hoteishiki kaiseki. Laser ko kyushu koka

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, S.; Sugawara, H.; Ventzek, P.; Sakai, Y. [Hokkaido University, Sapporo (Japan)

    1998-06-01

    Xe/Ne plasmas are important for plasma display panels and VUV light sources. However, reactions between electrons and excited particles in the mixtures are so complicated that influence of the reactions on the plasma properties is not understood well. In this work, taking account of reactions through which electrons are produced, such as cumulative and Penning ionization, and of transition between excited levels, the electron and excited particle properties in Xe/Ne plasmas are calculated using the Boltzmann equation. The ionization coefficient and electron drift velocity agreed with experimental data. The influence of laser absorption in Xe/Ne plasmas on the plasma properties is also discussed. 25 refs., 15 figs.

  12. Dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fortov, Vladimir E; Khrapak, Aleksei G; Molotkov, Vladimir I; Petrov, Oleg F [Institute for High Energy Densities, Associated Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation); Khrapak, Sergei A [Max-Planck-Institut fur Extraterrestrische Physik, Garching (Germany)

    2004-05-31

    The properties of dusty plasmas - low-temperature plasmas containing charged macroparticles - are considered. The most important elementary processes in dusty plasmas and the forces acting on dust particles are investigated. The results of experimental and theoretical investigations of different states of strongly nonideal dusty plasmas - crystal-like, liquid-like, gas-like - are summarized. Waves and oscillations in dusty plasmas, as well as their damping and instability mechanisms, are studied. Some results on dusty plasma investigated under microgravity conditions are presented. New directions of experimental research and potential applications of dusty plasmas are discussed. (reviews of topical problems)

  13. Articulatory Parameters.

    Science.gov (United States)

    Ladefoged, Peter

    1980-01-01

    Summarizes the 16 parameters hypothesized to be necessary and sufficient for linguistic phonetic specifications. Suggests seven parameters affecting tongue shapes, three determining the positions of the lips, one controlling the position of the velum, four varying laryngeal actions, and one controlling respiratory activity. (RL)

  14. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian;

    2011-01-01

    of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set...

  15. Leader as achiever.

    Science.gov (United States)

    Dienemann, Jacqueline

    2002-01-01

    This article examines one outcome of leadership: productive achievement. Without achievement one is judged to not truly be a leader. Thus, the ideal leader must be a visionary, a critical thinker, an expert, a communicator, a mentor, and an achiever of organizational goals. This article explores the organizational context that supports achievement, measures of quality nursing care, fiscal accountability, leadership development, rewards and punishments, and the educational content and teaching strategies to prepare graduates to be achievers.

  16. Spectroscopic studies of microwave plasmas containing hexamethyldisiloxane

    Science.gov (United States)

    Nave, A. S. C.; Mitschker, F.; Awakowicz, P.; Röpcke, J.

    2016-10-01

    Low-pressure microwave discharges containing hexamethyldisiloxane (HMDSO) with admixtures of oxygen and nitrogen, used for the deposition of silicon containing films, have been studied spectroscopically. Optical emission spectroscopy (OES) in the visible spectral range has been combined with infrared laser absorption spectroscopy (IRLAS). The experiments were carried out in order to analyze the dependence of plasma chemical phenomena on power and gas mixture at relatively low pressures, up to 50 Pa, and power values, up to 2 kW. The evolution of the concentration of the methyl radical, CH3, and of seven stable molecules, HMDSO, CH4, C2H2, C2H4, C2H6, CO and CO2, was monitored in the plasma processes by in situ IRLAS using tunable lead salt diode lasers (TDL) and external-cavity quantum cascade lasers (EC-QCL) as radiation sources. To achieve reliable values for the gas temperature inside and outside the plasma bulk as well as for the temperature in the plasma hot and colder zones, which are of great importance for calculation of species concentrations, three different methods based on emission and absorption spectroscopy data of N2, CH3 and CO have been used. In this approach line profile analysis has been combined with spectral simulation methods. The concentrations of the various species, which were found to be in the range between 1011 to 1015 cm-3, are in the focus of interest. The influence of the discharge parameters power, pressure and gas mixture on the molecular concentrations has been studied. To achieve further insight into general plasma chemical aspects the dissociation of the HMDSO precursor gas including its fragmentation and conversion to the reaction products was analyzed in detail.

  17. Achieving High Accuracy in Calculations of NMR Parameters

    DEFF Research Database (Denmark)

    Faber, Rasmus

    Nuclear magnetic resonance (NMR) spectroscopy is one of the most commonly used tools in the analysis of chemical structures. In NMR the nuclear spin-states of a molecule are probed, yielding information about the chemical environment of each nucleus. As the spins of nearby nuclei interact, concre...

  18. Inventory parameters

    CERN Document Server

    Sharma, Sanjay

    2017-01-01

    This book provides a detailed overview of various parameters/factors involved in inventory analysis. It especially focuses on the assessment and modeling of basic inventory parameters, namely demand, procurement cost, cycle time, ordering cost, inventory carrying cost, inventory stock, stock out level, and stock out cost. In the context of economic lot size, it provides equations related to the optimum values. It also discusses why the optimum lot size and optimum total relevant cost are considered to be key decision variables, and uses numerous examples to explain each of these inventory parameters separately. Lastly, it provides detailed information on parameter estimation for different sectors/products. Written in a simple and lucid style, it offers a valuable resource for a broad readership, especially Master of Business Administration (MBA) students.

  19. Plasma opening switch with extrinsic magnetic field

    CERN Document Server

    Dolgachev, G; Maslennikov, D

    2001-01-01

    Summary form only given, as follows. We have demonstrated in series of experiments that plasma opening switch (POS) switching voltage (UPOS) is defined by energy density (w) deposited in the POS plasma. If we then consider a plasma erosion mainly responsible for the effect of POS switching (the erosion effect could be described by Hall or Child-Langmuir models) the energy density (w) could be measured as a function of a system "macro-parameter" such as the initial charging voltage of the capacity storage system (the Marx pulsed voltage generator) UMarx. The POS voltage in this case could be given by UPOS"aw=aUMarx4/7, where a is a constant. This report demonstrates that for the high-impedance POS which has limited charge density transferred through the POS plasma a"2.5 (MV3/7) with no external magnetic field applied. The use of the extrinsic magnetic field allows to increase a up to 3.6 (MV3/7) and to achieve higher voltages at the opening phase - UPOS=3.6UMarx4/7. To verify this approach set of experimental ...

  20. Turbulent transport in magnetized plasmas

    CERN Document Server

    Horton, Wendell

    2012-01-01

    This book explains how magnetized plasmas self-organize in states of electromagnetic turbulence that transports particles and energy out of the core plasma faster than anticipated by the fusion scientists designing magnetic confinement systems in the 20th century. It describes theory, experiments and simulations in a unified and up-to-date presentation of the issues of achieving nuclear fusion power.

  1. Antenna coupling study for ICWC plasma characterization in TEXTOR

    Indian Academy of Sciences (India)

    Manash Kumar Paul; A Lyssoivan; R Koch; G Van Wassenhove; M Vervier; G Bertschinger; R Laengner; B Unterberg; G Sergienko; V Philipps; T Wauters; the TEXTOR Team

    2013-01-01

    Ion cyclotron wall conditioning (ICWC) discharges, in pulsed-mode operation, were carried out in the limiter tokamak TEXTOR to explore safe operational regimes for the experimental parameters for possible ICWC-discharge cleaning in International Thermonuclear Experimental Reactor (ITER) at half field. Antenna coupling properties obtained during the ion cyclotron range of frequencies (ICRF) wall conditioning experiments performed in helium–hydrogen mixture in TEXTOR were analysed in relation to the obtained ICWC-plasma characterization results. Satisfactory antenna coupling in the mode conversion scenario along with reproducible generation of ICRF plasmas for wall conditioning, were achieved by coupling radio frequency (RF) power from one or two ICRF antennas. The plasma breakdown results obtained in the TEXTOR tokamak have been compared with the predictions of a zero-dimensional RF plasma production model. The present study of ICWC emphasizes the beneficial effect of application of an additional (along with toroidal magnetic field) stationary vertical ($B_{V} \\ll B_{T}$) or oscillating poloidal magnetic field ($B_{P} \\ll B_{T}$) on antenna coupling and relevant plasma parameters.

  2. 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

  3. 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

  4. Plasma compression in magnetic reconnection regions in the solar corona

    CERN Document Server

    Provornikova, Elena; Lukin, Vyacheslav S

    2016-01-01

    It has been proposed that particles bouncing between magnetized flows converging in a reconnection region can be accelerated by the first order Fermi mechanism. Analytical considerations of this mechanism have shown that the spectral index of accelerated particles is related to the total plasma compression within the reconnection region similarly to the case of diffusive shock acceleration mechanism. As a first step to investigate the efficiency of Fermi acceleration in reconnection regions in producing hard energy spectra of particles in the solar corona, we explore the degree of plasma compression that can be achieved at reconnection sites. In particular, we aim to determine the conditions for the strong compressions to form. Using a two-dimensional resistive MHD numerical model we consider a set of magnetic field configurations where magnetic reconnection can occur including a Harris current sheet, a force-free current sheet, and two merging flux ropes. Plasma parameters are taken to be characteristic of t...

  5. Comparing Science Achievement Constructs: Targeted and Achieved

    Science.gov (United States)

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  6. 脑出血大鼠肠黏膜组织形态学变化与血浆儿茶酚胺水平的关系%Correlation between intestinal mucosa tissue morphologic parameters and plasma catecholamines level in rats with cerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    邱月; 宁显忠

    2012-01-01

    目的 探讨脑出血大鼠肠黏膜组织形态学变化与血浆儿茶酚胺(肾上腺素、去甲肾上腺素)水平之间的关系.方法 制作脑出血大鼠模型,检测正常组、假手术组及脑出血后24h、48h、72h(每组8只)肠黏膜组织形态学参数及血浆肾上腺素、去甲肾上腺素水平.进行空肠黏膜组织形态学参数值与血浆肾上腺素、去甲肾上腺素水平之间的相关分析.结果 小肠绒毛高度与血浆肾上腺素(r=-0.566,P<0.01)、血浆去甲肾上腺索(r=-0.545,P<0.01);绒毛面积与血浆肾上腺素(r=-0.755,P<0.01)、血浆去甲肾上腺素(r=-0.702,P <0.01);黏膜厚度与血浆肾上腺素(r=-0.478,P<0.01)、血浆去甲肾上腺素(r=-0.405,P<0.01);肠壁厚度与与血浆肾上腺素(r=-0.536,P<0.01)、血浆去甲肾上腺素肠(r=-0.489,P<0.01)均成显著的负相关.结论 脑出血时肠黏膜组织形态学变化与血浆儿茶酚胺水平呈负相关.%Objective To explore the correlation between intestinal mucosa tissue morphologic changes and plasma catecholamines(adrenaline and nurepinephrine) level in rats with cerebral hemorrhage. Methods A rat model of hemorrhage was used to detect the intestinal mucosa tissue morphologic parameters changes and the plasma catecholamines (adrenaline and norepinephrine) level at 24h,48h and 72h after the hemorrhage. The results were compared to normal control group and the sham-operated group. The correlation between the jejunal mucosa tissue morphologic parameters changes and plasma adrenaline and plasma norepinephrine were also explored. Results Small intestinal villous height was negatively correlated with the level of plasma adrenaline (r = - 0. 566, P < 0. 01) and plasma norepinephrine (r = - 0. 545, P < 0.01) . Small intestinal villous area was negatively correlated with the level of plasma adrenaline ( r = - 0. 755, P < 0. 01 ) and plasma norepinephrine( r = - 0. 702, P < 0. 01). Mucosal thickness was negatively

  7. 工艺参数对激光重熔等离子喷涂Ni基WC复合涂层影响%Effect of Process Parameters on Plasma-Sprayed Ni-Based and WC Composited Coatings by Laser Remelting

    Institute of Scientific and Technical Information of China (English)

    王东生; 田宗军; 屈光; 杨斌; 沈理达; 黄因慧

    2012-01-01

    The effects of laser remelting parameters on microstructure and properties of nickel (Ni) -based and tungsten carbide (WC) composited coatings prepared by plasma spraying were studied. The microstructural characteristics, microhardness, fiction and wear behaviour of the coatings were investigated using scanning electron microscopy (SEM), microhardness measurement and a ball—on-disk tribometer. The results show that the defects of as -sprayed coating like lamellar stacking microstructure and pores were eliminated by laser remelting, and the remelted coating possessed a denser microstructure. With the increase of the laser power, the burning loss and dissolve of the WC particles is increased, while the dilution of the coating becomes large. The laser-remelted samples had higher hardness, better wear resistance than the as-sprayed coating. Laser power has a great impact on the coating and an optimized process parameter is help to achieve appropriate melting of WC particles, which lead to retain a high proportion of hard phase in the coating, good combination between the WC particles and the Ni-base matrix alloy, so that the coating owns high microhardness and wear resistance.%采用激光重熔工艺对等离子喷涂预置Ni基WC复合涂层进行处理,研究了激光工艺参数对涂层微观组织和性能的影响.用扫描电镜(SEM)、显微硬度计和球-盘式摩擦磨损机分析了涂层微观结构、显微硬度和高温摩擦磨损特性.结果表明,激光重熔消除了等离子喷涂层的片层状结构、孔隙等缺陷,涂层致密性提高;随着激光功率的增加,WC颗粒烧损和溶解增多,同时涂层稀释率变大;激光重熔处理后涂层的显微硬度和磨损性能显著高于原等离子喷涂层,但激光功率对其有较大的影响,工艺参数的合理选择有利于WC颗粒适当熔化,从而在涂层中保留较高比例的硬质相,同时使WC颗粒与Ni基体的结合较强,达到较高的显微硬度和耐磨性能.

  8. Application of plasma technology for the modification of polymer and textile materials

    Directory of Open Access Journals (Sweden)

    Radetić Maja M.

    2004-01-01

    Full Text Available Plasma treatment is based on the physico-chemical changes of the material surface and as an ecologically and economically acceptable process it can be an attractive alternative to conventional modifications. The possibilities of plasma technology application to the modification of polymer and textile materials are discussed. Different specific properties of the material can be achieved by plasma cleaning, etching, functionalization or polymerization. The final effects are strongly influenced by the treatment parameters (treatment time, pressure, power, gas flow, the applied gas and nature of the material. The plasma treatment of polymers is predominantly focused on cleaning and activation of the surfaces to increase adhesion, binding, wettability, dye ability and printability. Current studies deal more with plasma polymerization where an ultra thin film of plasma polymer is deposited on the material surface and, depending on the applied monomer, different specific properties can be obtained (i.e. chemical and thermal resistance, abrasion resistance, antireflexion, water repellence, etc.. Plasma application to textiles is mostly oriented toward wool and synthetic fibres, though some studies also consider cotton, hemp, flax and silk. The main goal of plasma treatment is to impart a more hydrophilic fibre surface and accordingly increase wettability, dye ability, printability and particularly, shrink resistance in the case of wool. Recent studies have favored technical textiles, where plasma polymerization can offer a wide range of opportunities.

  9. Proton driven plasma wakefield generation in a parabolic plasma channel

    Science.gov (United States)

    Golian, Y.; Dorranian, D.

    2016-11-01

    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.

  10. Plasma assisted deposition of metal fluorides for 193nm applications

    Science.gov (United States)

    Bischoff, Martin; Sode, Maik; Gaebler, Dieter; Kaiser, Norbert; Tuennermann, Andreas

    2008-10-01

    The ArF lithography technology requires a minimization of optical losses due to scattering and absorption. Consequently it is necessary to optimize the coating process of metal fluorides. The properties of metal fluoride thin films are mainly affected by the deposition methods, their parameters, and the vacuum conditions. Until now the best results were achieved by metal boat evaporation with high substrate temperature and without plasma assistance. In fact, it was demonstrated that the plasma assisted deposition process results in optical thin films with high packing density but the losses due to absorption were extremely high for deep and vacuum ultraviolet applications. This paper will demonstrate that most of the common metal fluorides can be deposited by electron beam evaporation with plasma assistance. In comparison to other deposition methods, the prepared thin films show low absorption in the VUV spectral range, high packing density, and less water content. The densification of the thin films was performed by a Leybold LION plasma source. As working gas, a variable mixture of fluorine and argon gas was chosen. To understand the deposition process and the interaction of the plasma with the deposition material, various characterization methods like plasma emission spectroscopy and ion current measurements were implemented.

  11. Advanced plasma flow simulations of cathodic-arc and ferroelectric plasma sources for neutralized drift compression experiments

    Directory of Open Access Journals (Sweden)

    Adam B. Sefkow

    2008-07-01

    Full Text Available Large-space-scale and long-time-scale plasma flow simulations are executed in order to study the spatial and temporal evolution of plasma parameters for two types of plasma sources used in the neutralized drift compression experiment (NDCX. The results help assess the charge neutralization conditions for ion beam compression experiments and can be employed in more sophisticated simulations, which previously neglected the dynamical evolution of the plasma. Three-dimensional simulations of a filtered cathodic-arc plasma source show the coupling efficiency of the plasma flow from the source to the drift region depends on geometrical factors. The nonuniform magnetic topology complicates the well-known general analytical considerations for evaluating guiding-center drifts, and particle-in-cell simulations provide a self-consistent evaluation of the physics in an otherwise challenging scenario. Plasma flow profiles of a ferroelectric plasma source demonstrate that the densities required for longitudinal compression experiments involving ion beams are provided over the drift length, and are in good agreement with measurements. Simulations involving azimuthally asymmetric plasma creation conditions show that symmetric profiles are nevertheless achieved at the time of peak on-axis plasma density. Also, the ferroelectric plasma expands upstream on the thermal expansion time scale, and therefore avoids the possibility of penetration into the acceleration gap and transport sections, where partial neutralization would increase the beam emittance. Future experiments on NDCX will investigate the transverse focusing of an axially compressing intense charge bunch to a sub-mm spot size with coincident focal planes using a strong final-focus solenoid. In order to fill a multi-tesla solenoid with the necessary high-density plasma for beam charge neutralization, the simulations predict that supersonically injected plasma from the low-field region will penetrate and

  12. Surface modification of aramid fiber by plasma induced vapor phase graft polymerization of acrylic acid. I. Influence of plasma conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.X., E-mail: cxwang@mail.dhu.edu.cn [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Du, M. [College of Textiles and Clothing, Yancheng Institute of Industry Technology, Jiangsu 224000 (China); Lv, J.C.; Zhou, Q.Q. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Ren, Y. [School of Textile and Clothing, Nantong University, Jiangsu 226019 (China); Liu, G.L.; Gao, D.W. [College of Textiles and Clothing, Yancheng Institute of Technology, Jiangsu 224003 (China); Jin, L.M. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204 (China)

    2015-09-15

    Highlights: • Aramid fiber surface was modified by PIVPGP of AA to improve wettability, adhesion. • Surface modification effect by PIVPGP of AA increased and then decreased with time. • Surface modification effect increased and then stayed unaltered with output power. • Ar plasma was the most effective in PIVPGP of AA on aramid fiber surface. • In studied range, optimum technology of PIVPGP of AA: Ar plasma, 15 min, 300 W. - Abstract: Plasma induced vapor phase graft polymerization (PIVPGP) method was applied to modify aramid fiber surface. In this study, aramid fibers were pretreated under various plasma conditions such as different treatment times, output powers and working gases to see how these plasma processing parameters influenced the PIVPGP of acrylic acid (AA) on aramid fiber surface and its surface structure and properties. The analysis results of atomic force microscope (AFM) and X-ray photoelectron spectroscope (XPS) showed the increase of surface roughness and the introduction of O=C−OH, which confirmed that the PIVPGP of AA on aramid fiber surface was achieved. The contact angle and interfacial shear strength (IFSS) of the aramid fibers modified by PIVPGP of AA prominently decreased and increased, respectively, indicating the obvious improvements of surface wettability and adhesion between aramid fiber and matrix. The surface modification effects of aramid fiber by PIVPGP of AA firstly increased and then after 15 min slightly decreased with the increasing plasma treatment time, and but firstly increased and then after 300 W nearly remained unchanged with the increasing output power, respectively. Among different working gases, Ar plasma occupied first place, O{sub 2} plasma and N{sub 2} plasma came second and third in the aspect of PIVPGP of AA on aramid fiber surface, respectively. It could be concluded that the PIVPGP of AA on aramid fiber surface could effectively improve surface wettability and adhesion. Plasma conditions had signally

  13. Spark plasma sintering and spark plasma joining of refractory ceramics

    Science.gov (United States)

    Hoefer, Jeffrey Andrew

    Consolidation of refractory ceramics such as boron carbide (B4C) and silicon carbide (SiC) by conventional sintering techniques (pressure-less sintering, hot pressing, hot isostatic pressing etc.) can prove challenging due to the high temperatures required for sintering. Typically sintering additives are used in order to decrease sintering temperature, but at the sacrifice of purity. Typically B4C requires sintering temperatures above 2000°C without the use of additives, while SiC is generally considered not sinterable without additives, and requires temperatures above 2000°C even with additives. Spark Plasma Sintering (SPS) has emerged as a technology that can reduce the sintering temperature considerably compared to more conventional techniques. The simultaneous application of pressure, heat, and current can reduce sintering temperatures without the use of sintering aids to 1600°C and 2000°C for boron carbide and silicon carbide respectively. One shortcoming of SPS, however, is the difficulty in producing complex shapes. Therefore, for carbide materials such as B4C and SiC, which are difficult to machine, the ability to produce complex shapes is worthy of investigation. One means of creating complex shapes is by joining simple shapes. Joining of monolithic ceramics, in particular SiC, has been achieved, however in all cases an intermediate joining material is used (Ti foil, Silica Powder etc.). Joining of materials using SPS, or as it is called, Spark Plasma Joining, can eliminate the need for an intermediate joining material, producing a high purity and high strength joint. This study investigates SPS of 3 different B4C Powders, as well as SPS joining of simple shape monolithic SiC. Sintering parameters such as temperature, pressure, time, and heating rate are all considered. Influence of sintering parameters on density, grain size, mechanical strength, and joint quality is investigated in detail.

  14. Advanced plasma diagnostics for plasma processing

    Science.gov (United States)

    Malyshev, Mikhail Victorovich

    1999-10-01

    A new, non-intrusive, non-perturbing diagnostic method was developed that can be broadly applied to low pressure, weakly ionized plasmas and glow discharges-trace rare gases optical emission spectroscopy (TRG-OES). The method is based on a comparison of intensities of atomic emission from trace amounts of inert gases (He, Ne, Ar, Kr, and Xe) that are added to the discharge to intensities calculated from the theoretical model. The model assumes a Maxwellian electron energy distribution function (EEDF), computes the population of emitting levels both from the ground state and the metastable states of rare gases, and from the best fit between theory and experiment determines electron temperature (Te). Subject to conditions, TRG-OES can also yield electron density or its upper or lower limit. From the comparison of the emission from levels excited predominantly by high energy electrons to that excited by low energy electrons, information about the EEDF can be obtained. The use of TRG-OES also allows a traditionally qualitative actinometry technique (determination of concentration of radical species in plasma through optical emission) to become a precise quantitative method by including Te and rare gases metastables effects. A combination of TRG-OES, advanced actinometry, and Langmuir probe measurements was applied to several different plasma reactors and regimes of operation. Te measurements and experiments to correct excitation cross section were conducted in a laboratory helical resonator. Two chamber configuration of a commercial (Lam Research) metal etcher were studied to determine the effects of plasma parameters on plasma-induced damage. Two different methods (RF inductive coupling and ultra-high frequency coupling) for generating a plasma in a prototype reactor were also studied. Pulsed plasmas, a potential candidate to eliminate the plasma-induced damage to microelectronics devices that occurs in manufacturing due to differential charging of the wafer, have

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

    Science.gov (United States)

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

    2009-10-01

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

  16. Single Parameter Range and Whole Parameter Range, and Assessment of Novelty

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It is a relatively common phenomenon to limit technical features with parameter range in patent claims. It is argued in this article that the parameter range should be distinctly divided into single parameter range and whole parameter range depending on the different mode and function of limitation. Each and every parameter in a single parameter range may independently achieve a technical effect, and limit one embodiment alone; while a single parameter in the whole parameter range cannot independently ac...

  17. Achievable Precision for Optical Ranging Systems

    Science.gov (United States)

    Moision, Bruce; Erkmen, Baris I.

    2012-01-01

    Achievable RMS errors in estimating the phase, frequency, and intensity of a direct-detected intensity-modulated optical pulse train are presented. For each parameter, the Cramer-Rao-Bound (CRB) is derived and the performance of the Maximum Likelihood estimator is illustrated. Approximations to the CRBs are provided, enabling an intuitive understanding of estimator behavior as a function of the signaling parameters. The results are compared to achievable RMS errors in estimating the same parameters from a sinusoidal waveform in additive white Gaussian noise. This establishes a framework for a performance comparison of radio frequency (RF) and optical science. Comparisons are made using parameters for state-of-the-art deep-space RF and optical links. Degradations to the achievable errors due to clock phase noise and detector jitter are illustrated.

  18. Exomars Mission Achievements

    Science.gov (United States)

    Lecomte, J.; Juillet, J. J.

    2016-12-01

    ExoMars is the first step of the European Space Agency's Aurora Exploration Programme. Comprising two missions, the first one launched in 2016 and the second one to be launched in 2020, ExoMars is a program developed in a broad ESA and Roscosmos co-operation, with significant contribution from NASA that addresses the scientific question of whether life ever existed on Mars and demonstrate key technologies for entry, descent, landing, drilling and roving on the Martian surface . Thales Alenia Space is the overall prime contractor of the Exomars program leading a large industrial team The Spacecraft Composite (SCC), consisting of a Trace Gas Orbiter (TGO) and an EDL (Entry Descend and Landing) Demonstrator Module (EDM) named Schiaparelli, has been launched on 14 March 2016 from the Baikonur Cosmodrome by a Proton Launcher. The two modules will separate on 16 October 2016 after a 7 months cruise. The TGO will search for evidence of methane and other atmospheric gases that could be signatures of active biological or geological processes on Mars and will provide communications relay for the 2020 surface assets. The Schiaparelli module will prove the technologies required to safely land a payload on the surface of Mars, with a package of sensors aimed to support the reconstruction of the flown trajectory and the assessment of the performance of the EDL subsystems. For the second Exomars mission a space vehicle composed of a Carrier Module (CM) and a Descent Module (DM), whose Landing Platform (LP) will house a Rover, will begin a 7 months long trip to Mars in August 2020. In 2021 the Descent Module will be separated from the Carrier to carry out the entry into the planet's atmosphere and subsequently make the Landing Platform and the Rover land gently on the surface of Mars. While the LP will continue to measure the environmental parameters of the landing site, the Rover will begin exploration of the surface, which is expected to last 218 Martian days (approx. 230 Earth

  19. The Madison plasma dynamo experiment: A facility for studying laboratory plasma astrophysics

    Science.gov (United States)

    Cooper, C. M.; Wallace, J.; Brookhart, M.; Clark, M.; Collins, C.; Ding, W. X.; Flanagan, K.; Khalzov, I.; Li, Y.; Milhone, J.; Nornberg, M.; Nonn, P.; Weisberg, D.; Whyte, D. G.; Zweibel, E.; Forest, C. B.

    2014-01-01

    The Madison plasma dynamo experiment (MPDX) is a novel, versatile, basic plasma research device designed to investigate flow driven magnetohydrodynamic instabilities and other high-β phenomena with astrophysically relevant parameters. A 3 m diameter vacuum vessel is lined with 36 rings of alternately oriented 4000 G samarium cobalt magnets, which create an axisymmetric multicusp that contains ˜14 m3 of nearly magnetic field free plasma that is well confined and highly ionized (>50%). At present, 8 lanthanum hexaboride (LaB6) cathodes and 10 molybdenum anodes are inserted into the vessel and biased up to 500 V, drawing 40 A each cathode, ionizing a low pressure Ar or He fill gas and heating it. Up to 100 kW of electron cyclotron heating power is planned for additional electron heating. The LaB6 cathodes are positioned in the magnetized edge to drive toroidal rotation through J × B torques that propagate into the unmagnetized core plasma. Dynamo studies on MPDX require a high magnetic Reynolds number Rm > 1000, and an adjustable fluid Reynolds number 10 1). Initial results from MPDX are presented along with a 0-dimensional power and particle balance model to predict the viscosity and resistivity to achieve dynamo action.

  20. Relativistic QED Plasma at Extremely High Temperature

    CERN Document Server

    Masood, Samina S

    2016-01-01

    Renormalization scheme of QED (Quantum Electrodynamics) at high temperatures is used to calculate the effective parameters of relativistic plasma in the early universe. Renormalization constants of QED play role of effective parameters of the theory and can be used to determine the collective behavior of the medium. We explicitly show that the dielectric constant, magnetic reluctivity, Debye length and the plasma frequency depend on temperature in the early universe. Propagation speed, refractive index, plasma frequency and Debye shielding length of a QED plasma are computed at extremely high temperatures in the early universe. We also found the favorable conditions for the relativistic plasma from this calculations.

  1. 'No delays achiever'.

    Science.gov (United States)

    2007-05-01

    The latest version of the NHS Institute for Innovation and Improvement's 'no delays achiever', a web based tool created to help NHS organisations achieve the 18-week target for GP referrals to first treatment, is available at www.nodelaysachiever.nhs.uk.

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

    Science.gov (United States)

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

    2012-09-01

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

  3. Atomic and molecular processes in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Janev, R.K. [International Atomic Energy Agency, Vienna (Austria)

    1997-01-01

    The role of atomic and molecular processes in achieving and maintaining the conditions for thermonuclear burn in a magnetically confined fusion plasma is described. Emphasis is given to the energy balance and power and particle exhaust issues. The most important atomic and molecular processes which affect the radiation losses and impurity transport in the core plasma, the neutral particle transport in the plasma edge and the radiative cooling of divertor plasmas are discussed in greater detail. (author)

  4. Enhanced toroidal flow stabilization of edge localized modes with increased plasma density

    Science.gov (United States)

    Cheng, Shikui; Zhu, Ping; Banerjee, Debabrata

    2017-09-01

    Toroidal flow alone is generally thought to have an important influence on tokamak edge pedestal stability, even though theoretical analysis often predicts merely a weak stabilizing effect of toroidal flow on the edge localized modes (ELMs) in experimental parameter regimes. For the first time, we find from two-fluid MHD calculations that such a stabilization, however, can be significantly enhanced by increasing the edge plasma density. Our finding resolves a long-standing mystery whether or how toroidal rotation can indeed have an effective influence on ELMs, and explains why the ELM mitigation and suppression by toroidal rotation are more favorably achieved in higher collisionality regime in recent experiments. The finding suggests a new control scheme on modulating toroidal flow stabilization of ELMs with plasma density, along with a new additional constraint on the optimal level of plasma density for the desired edge plasma conditions.

  5. Princeton Plasma Physics Laboratory annual report, October 1, 1991--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    This report discusses the following topics: Principal parameters achieved in experimental devices for fiscal year 1992; tokamak fusion test reactor; princeton beta experiment-modification; current drive experiment-upgrade; tokamak physics experiment/steady-state advanced tokamak; international thermonuclear experimental reactor; international collaboration; x-ray laser studies; plasma processing: Deposition and etching of thin films; pure electron plasma experiments; theoretical studies; tokamak modeling; high-field magnet project; engineering department; environment, safety, and health and quality assurance; technology transfer; office of human resources and administration; PPPL invention disclosures for fiscal year 1992; office of resource management; graduate education: plasma physics; graduate education: program in plasma science and technology; and science education program.

  6. [Improvement of PVC bio-carrier surface property by remote plasma].

    Science.gov (United States)

    Li, Ru; Chen, Jie-Rong; Chen, Jun; Yao, Xin

    2006-01-01

    The effects of various remote plasma, such as Ar, He, O2 and N2 on PVC bio-carrier surface modification were studied. The surface properties were characterized by the contact angle measurement and X-ray photoelectron spectroscopy (XPS). The role of all kinds of active species such as electrons, ions and free radicals involved in plasma surface modification were evaluated. Results show that the remote plasma treatments modify the PVC surface in both wettability and composition, the (O + N)/C of PVC surface increases from 7% to 22%, and the water contact angle decreases from 97 degrees to 15 degrees. The optimal results was achieved when plasma treatment parameters were set, that is treatment time 3 min, Ar flux at 20 cm3/s, power at 60W, sample position of 40 cm. The results show that the modified PVC Bio-carrier adhesion rate and capacity on the modified surface are greatly increased.

  7. Progress toward commissioning and plasma operation in NSTX-U

    Science.gov (United States)

    Ono, M.; Chrzanowski, J.; Dudek, L.; Gerhardt, S.; Heitzenroeder, P.; Kaita, R.; Menard, J. E.; Perry, E.; Stevenson, T.; Strykowsky, R.; Titus, P.; von Halle, A.; Williams, M.; Atnafu, N. D.; Blanchard, W.; Cropper, M.; Diallo, A.; Gates, D. A.; Ellis, R.; Erickson, K.; Hosea, J.; Hatcher, R.; Jurczynski, S. Z.; Kaye, S.; Labik, G.; Lawson, J.; LeBlanc, B.; Maingi, R.; Neumeyer, C.; Raman, R.; Raftopoulos, S.; Ramakrishnan, R.; Roquemore, A. L.; Sabbagh, S. A.; Sichta, P.; Schneider, H.; Smith, M.; Stratton, B.; Soukhanovskii, V.; Taylor, G.; Tresemer, K.; Zolfaghari, A.; The NSTX-U Team

    2015-07-01

    The National Spherical Torus Experiment-Upgrade (NSTX-U) is the most powerful spherical torus facility at PPPL, Princeton USA. The major mission of NSTX-U is to develop the physics basis for an ST-based Fusion Nuclear Science Facility (FNSF). The ST-based FNSF has the promise of achieving the high neutron fluence needed for reactor component testing with relatively modest tritium consumption. At the same time, the unique operating regimes of NSTX-U can contribute to several important issues in the physics of burning plasmas to optimize the performance of ITER. NSTX-U further aims to determine the attractiveness of the compact ST for addressing key research needs on the path toward a fusion demonstration power plant (DEMO). The upgrade will nearly double the toroidal magnetic field BT to 1 T at a major radius of R0 = 0.93 m, plasma current Ip to 2 MA and neutral beam injection (NBI) heating power to 14 MW. The anticipated plasma performance enhancement is a quadrupling of the plasma stored energy and near doubling of the plasma confinement time, which would result in a 5-10 fold increase in the fusion performance parameter nτ T. A much more tangential 2nd NBI system, with 2-3 times higher current drive efficiency compared to the 1st NBI system, is installed to attain the 100% non-inductive operation needed for a compact FNSF design. With higher fields and heating powers, the NSTX-U plasma collisionality will be reduced by a factor of 3-6 to help explore the favourable trend in transport towards the low collisionality FNSF regime. The NSTX-U first plasma is planned for the Summer of 2015, at which time the transition to plasma operations will occur.

  8. Atomic Emission, Absorption and Fluorescence in the Laser-induced Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Winefordner, J. D.

    2009-01-22

    The main result of our efforts is the development and successful application of the theoretical model of laser induced plasma (LIP) that allows a back-calculation of the composition of the plasma (and the condensed phase) based on the observable plasma spectrum. The model has an immediate experimental input in the form of LIP spectra and a few other experimentally determined parameters. The model is also sufficiently simple and, therefore, practical. It is conveniently interfaced in a graphical user-friendly form for using by students and any laboratory personnel with only minimal training. In our view, the model opens up the possibility for absolute analysis, i.e. the analysis which requires no standards and tedious calibration. The other parts of this proposal (including plasma diagnostics) were somewhat subordinate to this main goal. Plasma diagnostics provided the model with the necessary experimental input and led to better understanding of plasma processes. Another fruitful direction we pursued was the use of the correlation analysis for material identification and plasma diagnostics. Through a number of computer simulations we achieved a clear understanding of how, where and why this approach works being applied to emission spectra from a laser plasma. This understanding will certainly improve the quality of forensic and industrial analyses where fast and reliable material identification and sorting are required.

  9. Plasma Antenna

    OpenAIRE

    N M Vijay

    2014-01-01

    The fundamental base of plasma antenna is the use of an ionized medium as a conductor. The plasma antenna is a radiofrequency antenna formed by a plasma columns, Filaments or sheets, which are excited by a surface wave. The relevance of this device is how rapidly it can be turned on and off, only applying an electrical pulse. Besides its wide carrier frequency, the great directivity and controllable antenna shape. Otherwise a disadvantage is that it needs energy to be ionized....

  10. Scientific and Technological Challenges of Diagnosing Burning Plasmas

    Science.gov (United States)

    Boivin, R. L.

    2009-05-01

    Research in magnetically confined fusion is now approaching a major milestone which is in evaluating and controlling burning plasma conditions. This milestone will be first met in the ITER experiment, presently being built in Cadarache, France through an international partnership, which includes China, the European Union, India, Japan, South Korea, Russia and the United States. In order to achieve its mission of achieving burning plasma conditions, and possibly ignition, a comprehensive set of scientific instruments (diagnostics) is being planned. That set represents the culmination of more than 50 years of development and research. More than 40 plasma parameters will be measured, including many which will be directly controlled. Some of these measurements will be done for the first time, such as probing the production, distribution and behavior of fusion produced, i.e. alpha particles, a key element in sustaining the fusion reaction process. These measurements will need to be done in a hostile environment, where a large nuclear radiation field, substantial direct particle flux, long pulse length and lack of direct access will bring severe constraints. Furthermore, the needs of the experiment will demand high reliability, low maintenance and the ability to retain a good calibration over a long period of time. We will review the challenges of the task and the opportunities for scientific breakthroughs from these state-of-the-art diagnostics instruments, as they pertain to the specific context of burning plasma conditions, together with examples of where these measurements will directly impact our scientific understanding and ability to control these conditions.

  11. EDITORIAL: Plasma jets and plasma bullets Plasma jets and plasma bullets

    Science.gov (United States)

    Kong, M. G.; Ganguly, B. N.; Hicks, R. F.

    2012-06-01

    to 1990 with only 31 papers per year on average, and a total of some 1300 papers, precedes a considerable growth of some 35-50% in research activity every five years, over the last 20 years or so. As shown in the table, the annual dissemination of the field is more than 1600 papers and the total number of papers is in excess of 20000. This upwards trajectory is typical of a strong and growing subject area in physical science, with considerable capacity in both fundamental science and applications. PeriodNumber of papersPapers per annum 1948-1990130031 1991-19952279456 1996-20003447689 2001-20054571914 2006-201066401328 2011 1658 In many of the dense plasma jets discussed above, strong physical forces generated by the plasma are often desired and this favours plasma generation at elevated gas pressure, including atmospheric pressure, which favours a high level of gas ionization. Historically it has been challenging to reduce and control the strong physical forces in high-pressure plasmas for applications where these are unwanted, for example, surface modification of polymeric sheets [5]. Indeed, there is a real need for a vast range of material processing applications at temperatures below 100oC (or below 400 K) and this favours atmospheric-pressure plasma jets sustained far from thermal equilibrium with the dissipated electrical energy largely used not in heat generation but in unleashing non-equilibrium chemical reactions. The long-standing difficulty of effectively controlling the level of gas ionization at atmospheric pressure was overcome by the technological breakthrough of achieving atmospheric-pressure glow discharges in the late 1980s [6]. A related challenge stemming from high collisionality of atmospheric-pressure plasmas (v >> ω0) means that large-area plasmas sustained between parallel-plate electrodes are very susceptible to strong plasma instabilities when molecular gases are introduced for processing applications. This led to an effective

  12. Plasma physics

    CERN Document Server

    Drummond, James E

    2013-01-01

    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

  13. [Achievement of therapeutic objectives].

    Science.gov (United States)

    Mantilla, Teresa

    2014-07-01

    Therapeutic objectives for patients with atherogenic dyslipidemia are achieved by improving patient compliance and adherence. Clinical practice guidelines address the importance of treatment compliance for achieving objectives. The combination of a fixed dose of pravastatin and fenofibrate increases the adherence by simplifying the drug regimen and reducing the number of daily doses. The good tolerance, the cost of the combination and the possibility of adjusting the administration to the patient's lifestyle helps achieve the objectives for these patients with high cardiovascular risk. Copyright © 2014 Sociedad Española de Arteriosclerosis y Elsevier España, S.L. All rights reserved.

  14. Adoptees' Educational Achievements

    DEFF Research Database (Denmark)

    Olsen, Rikke Fuglsang

    to country of origin. The results suggest that the relatively small gap between non-kin adoptees’ and non-adoptees’ educational achievements widens between ages 20 and 25. Moreover, the results show some differences in educational outcomes among non-kin adoptees with different countries of origin.......This study analyses educational achievement at age 20 for 3,180 non-kin adoptees and at age 25 for 1,559 non-kin adoptees in Denmark by comparing them to non-adoptees. The study also analyses whether there are within-group differences in the educational achievement of non-kin adoptees according...

  15. Challenges in plasma and laser wakefield accelerated beams diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Cianchi, A., E-mail: alessandro.cianchi@roma2.infn.it [University of Rome Tor Vergata and INFN, V. della Ricerca Scientifica 1, 00133 Rome (Italy); Anania, M.P.; Bellaveglia, M.; Castellano, M.; Chiadroni, E.; Ferrario, M.; Gatti, G. [INFN-LNF - Via E. Fermi 40, 00044 Frascati (RM) (Italy); Marchetti, B. [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Mostacci, A. [University of Rome La Sapienza, P.le Aldo Moro 5, 00185 Rome (Italy); Pompili, R. [INFN-LNF - Via E. Fermi 40, 00044 Frascati (RM) (Italy); Ronsivalle, C. [ENEA C.R. Frascati, Via E. Fermi,45 00044 Frascati (RM) (Italy); Rossi, A.R.; Serafini, L. [INFN-Mi, Via Celoria, 16 20133 Milano (Italy)

    2013-08-21

    The new frontier in the particle beam accelerator is the so called plasma acceleration. Using the strong electric field inside a plasma it is possible to achieve accelerating gradients in the order of magnitude larger with respect to the actual technologies. Different schemes have been proposed and several already tested, producing beams of energy of several GeV. Mainly two approaches are followed: either the beam is directly produced by the interaction of a TW/PW class laser with a gas jet or a preexisting particle beam is accelerated in a plasma channel. In both cases a precise determination of the emerging beam parameters is mandatory for the fine tuning of the devices. The measurement of these parameters, in particular the emittance, is not trivial, mainly due to the large energy spread and to the tight focusing of these beams or to the background noise produced in the plasma channel. We show the problems related to the diagnostic of this kind of beams and the proposed or already realized solutions.

  16. Challenges in plasma and laser wakefield accelerated beams diagnostic

    Science.gov (United States)

    Cianchi, A.; Anania, M. P.; Bellaveglia, M.; Castellano, M.; Chiadroni, E.; Ferrario, M.; Gatti, G.; Marchetti, B.; Mostacci, A.; Pompili, R.; Ronsivalle, C.; Rossi, A. R.; Serafini, L.

    2013-08-01

    The new frontier in the particle beam accelerator is the so called plasma acceleration. Using the strong electric field inside a plasma it is possible to achieve accelerating gradients in the order of magnitude larger with respect to the actual technologies. Different schemes have been proposed and several already tested, producing beams of energy of several GeV. Mainly two approaches are followed: either the beam is directly produced by the interaction of a TW/PW class laser with a gas jet or a preexisting particle beam is accelerated in a plasma channel. In both cases a precise determination of the emerging beam parameters is mandatory for the fine tuning of the devices. The measurement of these parameters, in particular the emittance, is not trivial, mainly due to the large energy spread and to the tight focusing of these beams or to the background noise produced in the plasma channel. We show the problems related to the diagnostic of this kind of beams and the proposed or already realized solutions.

  17. Research on the Plasma Anemometer Based on AC Glow Discharge

    Directory of Open Access Journals (Sweden)

    Bing Yu

    2017-01-01

    Full Text Available A new plasma anemometer based on AC glow discharge is designed in this article. Firstly, theoretical analysis of plasma anemometer working principle is introduced to prove the feasibility of the experimental measurement method. Then the experiments are carried out to study the effects of different parameters on the static discharge characteristics of the plasma anemometer system, by which the system optimization methods are obtained. Finally, several groups of appropriate parameters are selected to build the plasma anemometer system based on resistance capacitance coupling negative feedback AC glow discharge, and different airflow speeds are applied to obtain the achievable velocity measurement range. The results show that there is a linear relationship between airflow velocity and discharge current in an allowable error range, which can be applied for airflow velocity measurement. Negative feedback coupling module, which is composed of the coupling resistance and the coupling capacitance, has good effects on improving the system stability. The measurement range of the airflow velocity is significantly increased when the electrode gap is 3 mm, coupling resistance is 470 Ω, and coupling capacitance is 220 pF.

  18. Kinetics of insulin disappearance from plasma in cortisone-treated normal subjects

    DEFF Research Database (Denmark)

    Ellemann, K; Thorsteinsson, B; Fugleberg, S

    1987-01-01

    The effect of glucocorticoid excess on insulin disappearance from plasma was examined in eight normal men during cortisone treatment (50 mg orally twice daily for 4 d) and in the absence of any medication (control) in random order. Constant infusion of insulin (1-5 mU/kg/min) was used to achieve...... infusions was significantly less in the cortisone study than in the control study, while the parameter estimates for the kinetics of insulin disappearance from plasma were unaffected by cortisone. Thus, insulin action and insulin kinetics in the steady state are dissociated in normal subjects rendered...... insulin resistant by short-term cortisone treatment....

  19. Spatial control of processing plasmas in a multicusp plasma source equipped with a movable magnetic filter

    Energy Technology Data Exchange (ETDEWEB)

    Fukumasa, O.; Naitou, H.; Sakiyama, S. (Yamaguchi Univ., Yamaguchi (Japan))

    1991-12-20

    The plasma chemical vapor deposition (p-CVD) method has been used in the preparation of various sorts of thin films such as hydrogenated amorphous silicon films and hydrogenated amorphous carbon films, etc. and the application feasibility of a magnetically filtered multicusp plasma source has been studied. In this paper, it is confirmed that plasma parameters (H {sub 2} - ch {sub 4} or Ar-CH {sub 4} plasmas) are spatially well controlled by using both a movable magnetic filter and a plasma grid. Plasma parameters change sharply across the magnetic filter at any filter position and the whole plasma is divided clearly into the region of source plasma with high-energy electrons and the region of diffused plasma without high-energy electrons. Concerning the role of the magnetic filter which reflects preferentially high-energy electrons, a study is made through computer simulation. 7 refs., 9 figs.

  20. Extinguishing ELMs in detached radiative divertor plasmas

    Science.gov (United States)

    Pigarov, Alexander; Krasheninnikov, Sergei; Rognlien, Thomas

    2016-10-01

    In order to avoid deleterious effects of ELMs on PFCs in next-step fusion devices it has been suggested to operate with small-sized ELMs naturally extinguishing in the divertor. Our modeling effort is focusing at extinguishing type-I ELMs: conditions for expelled plasma dissipation; efficiency of ELM power handling by detached radiative divertors; and the ELM impact on detachment state. Here time-dependent modeling of a sequence of many ELMs was performed with 2-D edge plasma transport code UEDGE-MB-W which incorporates the Macro-Blob (MB) approach to simulate non-diffusive filamentary transport and various ``Wall'' (W) models for time-dependent hydrogen wall inventory and recycling. Three cases were modeled, in which extinguishing ELMs are achieved due to: (i) intrinsic impurities via graphite sputtering, (ii) extrinsic impurity gas puff (Ne), and (iii) =(i) +(ii). For each case, we performed a series of UEDGE-MB-W runs scanning the deuterium and impurity inventories, pedestal losses and ELM frequency. Temporal variations of the degree of detachment, ionization front shape, recombination sink strength, radiated fraction, peak power loads, OSP, impurity charge states, and in/out asymmetries were analyzed. We discuss the onset of extinguishing ELMs, conditions for not burning through and enhanced plasma recombination as functions of scanned parameters. Efficiencies of intrinsic and extrinsic impurities in ELM extinguishing are compared.

  1. Supergranular Parameters

    Science.gov (United States)

    Udayashankar, Paniveni

    2016-07-01

    I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.

  2. Plasma-based radar cross section reduction

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a comprehensive review of plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The concealment of aircraft from radar sources, or stealth, is achieved through shaping, radar absorbing coatings, engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) waves by the plasma layer surrounding the structure. A plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generatio...

  3. PIC simulations of the production of high-quality electron beams via laser-plasma interaction

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, C. [Department of Physics, University of Bologna and INFN/Bologna, Via Irnerio 46, 40126 Bologna (Italy)], E-mail: carlo.benedetti@bo.infn.it; Londrillo, P. [INAF, Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna (Italy); Petrillo, V.; Serafini, L. [INFN/Milano, Via Celoria 14, 10133 Milano (Italy); Sgattoni, A. [Department of Physics, University of Bologna and INFN/Bologna, Via Irnerio 46, 40126 Bologna (Italy); Tomassini, P. [INFN/Milano, Via Celoria 14, 10133 Milano (Italy); Turchetti, G. [Department of Physics, University of Bologna and INFN/Bologna, Via Irnerio 46, 40126 Bologna (Italy)

    2009-09-01

    We present some numerical studies and parameter scans performed with the electromagnetic, relativistic, fully self-consistent Particle-In-Cell (PIC) code ALaDyn (Acceleration by LAser and DYNamics of charged particles), concerning the generation of a low emittance, high charge and low momentum spread electron bunch from laser-plasma interaction in the Laser WakeField Acceleration (LWFA) regime, in view of achieving beam brightness of interest for FEL applications.

  4. Characterization and modelling of microwave multi dipole plasmas. Application to multi dipolar plasma assisted sputtering; Caracterization et modelisation des plasmas micro-onde multi-dipolaires. Application a la pulverisation assistee par plasma multi-dipolaire

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Tan Vinh [Universite Joseph Fourier/CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

    2006-07-01

    The scaling up of plasma processes in the low pressure range remains a question to be solved for their rise at the industrial level. One solution is the uniform distribution of elementary plasma sources where the plasma is produced via electron cyclotron resonance (ECR) coupling. These elementary plasma sources are made up of a cylindrical permanent magnet (magnetic dipole) set at the end of a coaxial microwave line. Although of simple concept, the optimisation of these dipolar plasma sources is in fact a complex problem. It requires the knowledge, on one hand, of the configurations of static magnetic fields and microwave electric fields, and, on the other hand, of the mechanisms of plasma production in the region of high intensity magnetic field (ECR condition), and of plasma diffusion. Therefore, the experimental characterisation of the operating ranges and plasma parameters has been performed by Langmuir probes and optical emission spectroscopy on different configurations of dipolar sources. At the same time, in a first analytical approach, calculations have been made on simple magnetic field configurations, motion and trajectory of electrons in these magnetic fields, and the acceleration of electrons by ECR coupling. Then, the results have been used for the validation of the numerical modelling of the electron trajectories by using a hybrid PIC (particle-in-cell) / MC (Monte Carlo) method. The experimental study has evidenced large operating domains, between 15 and 200 W of microwave power, and from 0.5 to 15 mTorr argon pressure. The analysis of plasma parameters has shown that the region of ECR coupling is localised near the equatorial plane of the magnet and dependent on magnet geometry. These characterizations, applied to a cylindrical reactor using 48 sources, have shown that densities between 10{sup 11} and 10{sup 12} cm{sup -3} could be achieved in the central part of the volume at a few mTorr argon pressures. The modelling of electron trajectories near

  5. TAE modes and MHD activity in TFTR DT plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fredrickson, E.; Batha, S.; Bell, M.

    1995-03-01

    The high power deuterium and tritium experiments on TFTR have produced fusion a parameters similar to those expected on ITER. The achieved {beta}{sub {alpha}}/{beta} and the R{triangledown}{beta}{sub {alpha}} in TFRR D-T shots are 1/2 to 1/3 those predicted in the ITER EDA. Studies of the initial TFTR D-T plasmas find no evidence that the presence of the fast fusion {alpha} population has affected the stability of MHD, with the possible exception of Toroidal Alfven Eigenmodes (TAE`s). The initial TFTR DT plasmas had MHD activity similar to that commonly seen in deuterium plasmas. Operation of TFTR at plasma currents of 2.0--2.5 MA has greatly reduced the deleterious effects of MHD commonly observed at lower currents. Even at these higher currents, the performance of TFTR is limited by {beta}-limit disruptions. The effects of MHD on D-T fusion {alpha}`s was similar to effects observed on other fusion products in D only plasmas.

  6. High density plasma gun generates plasmas at 190 kilometers per second

    Science.gov (United States)

    Espy, P. N.

    1971-01-01

    Gun has thin metal foil disc which positions or localizes gas to be ionized during electrical discharge cycle, overcoming major limiting factor in obtaining such plasmas. Expanding plasma front travels at 190 km/sec, compared to plasmas of 50 to 60 km/sec previously achieved.

  7. Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3  MHz frequency at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, Sangeeta B., E-mail: p.sangeeta@gmail.com [Electrical Engineering Department, V.J.T.I., Matunga, Mumbai 400019 (India); Department of Physics, University of Mumbai, Kalina, Santacruz (E), Mumbai 400098 (India); Sahasrabudhe, S. N.; Das, A. K. [Laser and Plasma Technology Division, BARC, Mumbai 400085 (India); Joshi, N. K. [Faculty of Engineering and Technology, MITS, Lakshmangarh (Sikar), Rajasthan 332311 (India); Mangalvedekar, H. A. [Electrical Engineering Department, V.J.T.I., Matunga, Mumbai 400019 (India); Kothari, D. C. [Department of Physics, University of Mumbai, Kalina, Santacruz (E), Mumbai 400098 (India)

    2014-01-15

    This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50 kW DC power and 3 MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User Defined Function. A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications.

  8. Impact of lithium on the plasma performance in the all-metal-wall tokamak ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Lang, P.T.; Moreno Quicios, R.; Arredondo Parra, R.; Ploeckl, B.; McDermott, R.; Neu, R.; Wolfrum, E. [MPI fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Maingi, R.; Mansfield, D.K.; Diallo, A. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Collaboration: ASDEX Upgrade Team

    2016-07-01

    Several tokamaks reported improvement in key plasma parameters concurrent with the presence of lithium in the plasma. At ASDEX Upgrade explorative experiments have been performed to find out if such effects can be observed when operating with an all-metal-wall. A gas gun launcher was developed capable to inject pellets containing about 1.6 x 10{sup 20} Li atoms at 2 Hz. The speed of about 600 m/s is sufficient to achieve core penetration and to create a homogeneous Li concentration of up to 10 %. With a typical sustainment time on the order of 100 ms, only transient Li presence without any pile up was achieved. Deposition of Li on plasma facing components, which remained for several discharges after injection, was observed. This short lived wall conditioning showed beneficial effects during plasma start-up. However, the accompanying surface contamination negatively impacted some diagnostics. The Li impact on the confinement was investigated in a dedicated plasma scenario with a proven sensitivity to nitrogen and helium. In phases with N seeding enhancing the confinement by about 30 %, Li injection resulted in a very modest, transient loss of confinement (about 5 %). No Li impact was found for pure Deuterium plasmas.

  9. The segmented non-uniform dielectric module design for uniformity control of plasma profile in a capacitively coupled plasma chamber

    Directory of Open Access Journals (Sweden)

    Huanxiong Xia

    2014-12-01

    Full Text Available Low-temperature plasma technique is one of the critical techniques in IC manufacturing process, such as etching and thin-film deposition, and the uniformity greatly impacts the process quality, so the design for the plasma uniformity control is very important but difficult. It is hard to finely and flexibly regulate the spatial distribution of the plasma in the chamber via controlling the discharge parameters or modifying the structure in zero-dimensional space, and it just can adjust the overall level of the process factors. In the view of this problem, a segmented non-uniform dielectric module design solution is proposed for the regulation of the plasma profile in a CCP chamber. The solution achieves refined and flexible regulation of the plasma profile in the radial direction via configuring the relative permittivity and the width of each segment. In order to solve this design problem, a novel simulation-based auto-design approach is proposed, which can automatically design the positional sequence with multi independent variables to make the output target profile in the parameterized simulation model approximate the one that users preset. This approach employs an idea of quasi-closed-loop control system, and works in an iterative mode. It starts from initial values of the design variable sequences, and predicts better sequences via the feedback of the profile error between the output target profile and the expected one. It never stops until the profile error is narrowed in the preset tolerance.

  10. Modeling of defect generation during plasma etching and its impact on electronic device performance—plasma-induced damage

    Science.gov (United States)

    Eriguchi, Koji

    2017-08-01

    The increasing demand for the higher performance of ultra-large-scale integration (ULSI) circuits requires the aggressive shrinkage of device feature sizes in accordance with the scaling law. Plasma processing plays an important role in achieving fine patterns with anisotropic features in metal-oxide-semiconductor field-effect transistors (MOSFETs). This article comprehensively addresses the negative aspects of plasma processing, i.e. plasma process-induced damage, in particular, the defect creation induced by ion bombardment in Si substrates during plasma etching. The ion bombardment damage forms a surface modified region and creates localized defect structures. Modeling and characterization techniques of the ion bombardment damage in Si substrates are overviewed. The thickness of the modified region, i.e. the damaged layer, is modeled by a modified range theory and the density of defects is characterized by photoreflectance spectroscopy (PRS) and the capacitance-voltage technique. The effects of plasma-induced damage (PID) on MOSFET performance are presented. In addition, some of the emerging topics—the enhanced parameter variability in ULSI circuits and recovery of the damage—are discussed as future perspectives.

  11. The diverse applications of plasma

    Science.gov (United States)

    Sharma, Mukul; Dubey, Shivani; Darwhekar, Gajanan; Jain, Sudhir Kumar

    2015-07-01

    Plasma being the fourth state of matter has always been an attraction for Physicists and Chemists. With the advent of time, plasma energy has been recognized in having widening horizons in the field of Biomedical Sciences. Plasma medicine can be subdivided into three main fields; Non-thermal atmospheric-pressure direct plasma for medical therapy; Plasma-assisted modification of bio-relevant surfaces and Plasma-based bio-decontamination and sterilization. The basis of the research is that as it has free carrier molecules, it has the ability to target specific cells and regulate functions like wound healing. Plasma does not harm healthy human cells but can kill bacteria and possibly even cancer cells to help treat various diseases. Nosocomial infection control, prevention and containment of contagious diseases, disinfection of medical devices, surface treatment (heat and UV sensitive surfaces) are research of interest. Recent success in generating plasma at very low temperature ie. Cold plasma makes the therapy painless. It has the ability to activate cellular responses and important mechanisms in the body. They target specific molecules such as prothrombin for blood coagulation, cytokines for killing bacteria, and angiogenesis for tissue regeneration. Plasma has bactericidal, fungicidal and virucidal properties. Plasma technology has flourishing future in diverse fields like Textiles, Nanofabrication, Automotives, Waste management, Microbiology, Food Hygiene, Medical Science like Skin treatments, sterilisation of wounds, Hand disinfection, Dental treatments etc. Food hygiene using plasma can be achieved in disinfection of food containers, food surface disinfection, hygiene in food handling, preparation and packaging. Therefore Plasma is most promising field for budding Scientist for fluorishing research in Biological Sciences.

  12. The diverse applications of plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mukul, E-mail: mukulsharma@acropolis.edu.in; Darwhekar, Gajanan, E-mail: gdarwhekar@acropolis.edu.in [Acropolis Institute of Pharmaceutical Education & Research, Indore MP India (India); Dubey, Shivani, E-mail: dubeyshivani08@rediffmail.com [Mata Gujri College of Professional Studies, Indore MP India (India); Jain, Sudhir Kumar, E-mail: sudhirkjain1@rediffmail.com [School of Studies in Microbiology, Vikram University, Ujjain MP India (India)

    2015-07-31

    Plasma being the fourth state of matter has always been an attraction for Physicists and Chemists. With the advent of time, plasma energy has been recognized in having widening horizons in the field of Biomedical Sciences. Plasma medicine can be subdivided into three main fields; Non-thermal atmospheric-pressure direct plasma for medical therapy; Plasma-assisted modification of bio-relevant surfaces and Plasma-based bio-decontamination and sterilization. The basis of the research is that as it has free carrier molecules, it has the ability to target specific cells and regulate functions like wound healing. Plasma does not harm healthy human cells but can kill bacteria and possibly even cancer cells to help treat various diseases. Nosocomial infection control, prevention and containment of contagious diseases, disinfection of medical devices, surface treatment (heat and UV sensitive surfaces) are research of interest. Recent success in generating plasma at very low temperature ie. Cold plasma makes the therapy painless. It has the ability to activate cellular responses and important mechanisms in the body. They target specific molecules such as prothrombin for blood coagulation, cytokines for killing bacteria, and angiogenesis for tissue regeneration. Plasma has bactericidal, fungicidal and virucidal properties. Plasma technology has flourishing future in diverse fields like Textiles, Nanofabrication, Automotives, Waste management, Microbiology, Food Hygiene, Medical Science like Skin treatments, sterilisation of wounds, Hand disinfection, Dental treatments etc. Food hygiene using plasma can be achieved in disinfection of food containers, food surface disinfection, hygiene in food handling, preparation and packaging. Therefore Plasma is most promising field for budding Scientist for fluorishing research in Biological Sciences.

  13. Electron density and plasma dynamics of a colliding plasma experiment

    Energy Technology Data Exchange (ETDEWEB)

    Wiechula, J., E-mail: wiechula@physik.uni-frankfurt.de; Schönlein, A.; Iberler, M.; Hock, C.; Manegold, T.; Bohlender, B.; Jacoby, J. [Plasma Physics Group, Institute of Applied Physics, Goethe University, 60438 Frankfurt am Main (Germany)

    2016-07-15

    We present experimental results of two head-on colliding plasma sheaths accelerated by pulsed-power-driven coaxial plasma accelerators. The measurements have been performed in a small vacuum chamber with a neutral-gas prefill of ArH{sub 2} at gas pressures between 17 Pa and 400 Pa and load voltages between 4 kV and 9 kV. As the plasma sheaths collide, the electron density is significantly increased. The electron density reaches maximum values of ≈8 ⋅ 10{sup 15} cm{sup −3} for a single accelerated plasma and a maximum value of ≈2.6 ⋅ 10{sup 16} cm{sup −3} for the plasma collision. Overall a raise of the plasma density by a factor of 1.3 to 3.8 has been achieved. A scaling behavior has been derived from the values of the electron density which shows a disproportionately high increase of the electron density of the collisional case for higher applied voltages in comparison to a single accelerated plasma. Sequences of the plasma collision have been taken, using a fast framing camera to study the plasma dynamics. These sequences indicate a maximum collision velocity of 34 km/s.

  14. Achieving monospermy or preventing polyspermy?

    Directory of Open Access Journals (Sweden)

    Dale B

    2016-06-01

    Full Text Available Brian Dale Centre for Assisted Fertilization, Naples, Italy Abstract: Images of sea urchin oocytes with hundreds of spermatozoa attached to their surface have fascinated scientists for over a century and led to the idea that oocytes have evolved mechanisms to allow the penetration of one spermatozoon while repelling supernumerary spermatozoa. Popular texts have extrapolated this concept, to the mammals and amphibians, and in many cases to include all the Phyla. Here, it is argued that laboratory experiments, using sea urchin oocytes deprived of their extracellular coats and inseminated at high densities, are artifactual and that the experiments leading to the idea of a fast block to polyspermy are flawed. Under natural conditions, the number of spermatozoa at the site of fertilization is extremely low, compared with the numbers generated. The sperm:oocyte ratio is regulated first by dilution in externally fertilizing species and the female reproductive tract in those with internal fertilization, followed by a bottleneck created by the oocytes extracellular coats. In order to progress to the oocyte plasma membrane, the fertilizing spermatozoon must encounter and respond to a correct sequence of signals from the oocytes extracellular coats. Those that do not, are halted in their progression by defective signaling and fall to the wayside. Final success and entry is finely tuned by the spermatozoon anchoring to an actin-rich predetermined site on the plasma membrane. In this review, the variation in the form, function, and number of gametes produced across the animal kingdom and the many ways in which sperm–oocyte interactions are regulated to reduce numbers are discussed. Since in nature, final sperm:oocyte ratios approach unity it would appear that selective pressures have favored the achievement of monospermy, rather than the evolution of polyspermy preventing mechanisms. Keywords: monospermy, natural conditions, polyspermy, laboratory

  15. Effect of Wall Material on H– Production in a Plasma Sputter-Type Ion Source

    Directory of Open Access Journals (Sweden)

    Y. D. M. Ponce

    2004-12-01

    Full Text Available The effect of wall material on negative hydrogen ion (H– production was investigated in a multicusp plasma sputter-type ion source (PSTIS. Steady-state cesium-seeded hydrogen plasma was generated by a tungsten filament, while H– was produced through surface production using a molybdenum sputter target. Plasma parameters and H– yields were determined from Langmuir probe and Faraday cup measurements, respectively. At an input hydrogen pressure of 1.2 mTorr and optimum plasma discharge parameters Vd = –90 V and Id = –2.25 A, the plasma parameters ne was highest and T–e was lowest as determined from Langmuir probe measurements. At these conditions, aluminum generates the highest ion current density of 0.01697 mA/cm2, which is 64% more than the 0.01085 mA/cm2 that stainless steel produces. The yield of copper, meanwhile, falls between the two materials at 0.01164 mA/cm2. The beam is maximum at Vt = –125 V. Focusing is achieved at VL = –70 V for stainless steel, Vt = –60 V for aluminum, and Vt = –50 V for copper. The results demonstrate that proper selection of wall material can greatly enhance the H– production of the PSTIS.

  16. Modeling of Arc Force in Plasma Arc Welding

    Institute of Scientific and Technical Information of China (English)

    GAO Zhonglin; HU Shengsun; YIN Fengliang; WANG Rui

    2008-01-01

    A three. dimensional mathematical model for the transferred-type argon arc was developed to describe arc force on the anode surface. The software ANSYS was employed to solve the model. The model includes a part of torch and tungsten electrode to achieve m ore reasonable results. The arc temperature and flow fields were derived. And the influences of welding parameters on arc force were also studied. The simulated results show that arc pressure at the anode are dependent on the welding current, plasma gas flow rate and electrode neck-in, while not sensitive to arc length.

  17. Radial variation of refractive index, plasma frequency and phase velocity in laser induced air plasma

    CSIR Research Space (South Africa)

    Mathuthu, M

    2006-12-01

    Full Text Available induced air plasma to study the spatial variation of plasma parameters in the axial direction of the laser beam. In this paper, the authors report investigation on the radial variation of the refractive index, plasma frequency, and phase velocity of a...

  18. Coronal Seismology -- Achievements and Perspectives

    Science.gov (United States)

    Ruderman, Michael

    explanation of the oscillation damping is resonant absorption. The damping due to resonant absorption is, broadly speaking, proportional to the inhomogeneity scale of the density in the loop in the transverse direction. This fact was used to estimate the density inhomogeneity scale from the observations. The first observation of the coronal loop transverse oscillations gave a strong boost to the theoretical study of this phenomenon. In the last ten years theorists sufficiently refined their models taking into account such loop properties as the density variation in the longitudinal and transverse directions, the twist of the magnetic field, the non-circular loop cross-section, the variation of the cross-section along the loop, and the loop curvature. Now, to obtain more accurate estimates of the coronal plasma parameters, we need the following from the observations: (i) Since the frequency of the loop oscillation depends on the plasma density, more accurate data on this quantity is required. (ii) Since the estimate of the coronal temperature strongly depends of the loop shape, an accurate three-dimensional picture of the loop is desirable. (iii) The fundamental frequency and first overtone of the loop oscillation are sufficiently affected by the variation of the loop cross-section. The observational data on this quantity is important for further progress of the coronal seismology.

  19. Plasma Processing of Materials

    Science.gov (United States)

    1985-02-22

    used in France. In this case, three ’ movable electrodes arranged about the central axis with a coaxial sheath gas are employed. Initially the...Demiocratic Republic plasma furnace. chrome -magnesite; the bottom section is lined with rammed chrome -magnesite refractory. Due to the high heat loads... sheath injector design, cathode tip shape, and degree of water cooling are important parameters in providing a stable, uncontaminating, long-lifetime

  20. Plasma Sources for Medical Applications - A Comparison of Spot Like Plasmas and Large Area Plasmas

    Science.gov (United States)

    Weltmann, Klaus-Dieter

    2015-09-01

    Plasma applications in life science are currently emerging worldwide. Whereas today's commercially available plasma surgical technologies such as argon plasma coagulation (APC) or ablation are mainly based on lethal plasma effects on living systems, the newly emerging therapeutic applications will be based on selective, at least partially non-lethal, possibly stimulating plasma effects on living cells and tissue. Promising results could be obtained by different research groups worldwide revealing a huge potential for the application of low temperature atmospheric pressure plasma in fields such as tissue engineering, healing of chronic wounds, treatment of skin diseases, tumor treatment based on specific induction of apoptotic processes, inhibition of biofilm formation and direct action on biofilms or treatment of dental diseases. The development of suitable and reliable plasma sources for the different therapies requires an in-depth knowledge of their physics, chemistry and parameters. Therefore much basic research still needs to be conducted to minimize risk and to provide a scientific fundament for new plasma-based medical therapies. It is essential to perform a comprehensive assessment of physical and biological experiments to clarify minimum standards for plasma sources for applications in life science and for comparison of different sources. One result is the DIN-SPEC 91315, which is now open for further improvements. This contribution intends to give an overview on the status of commercial cold plasma sources as well as cold plasma sources still under development for medical use. It will discuss needs, prospects and approaches for the characterization of plasmas from different points of view. Regarding the manageability in everyday medical life, atmospheric pressure plasma jets (APPJ) and dielectric barrier discharges (DBD) are of special interest. A comprehensive risk-benefit assessment including the state of the art of commercial sources for medical use

  1. Application of Nonlocal Electron Kinetics to Plasma Technologies

    Science.gov (United States)

    Kaganovich, Igor D.

    2011-10-01

    Partially ionized plasmas are typically in a highly non-equilibrium thermodynamic state: the electrons are not in equilibrium with the neutral particle species or the ions, and the electrons are also not in equilibrium within their own ensemble, which results in a significant departure of the electron velocity distribution function (EVDF) from a Maxwellian. These non-equilibrium conditions provide considerable freedom to choose optimal plasma parameters for applications, which make gas-discharge plasmas remarkable tools for a variety of plasma applications, including plasma processing, discharge lighting, plasma propulsion, particle beam sources, and nanotechnology. Significant progress in understanding the formation of non-Maxwellian EVDF in the self-consistent electric fields has been one of the major achievements in the low-temperature plasmas during the last decade. This progress was made possible by a synergy between full-scale particle-in-cell simulations, analytical models, and experiments. Specific examples include rf discharges, dc discharges with auxiliary electrodes, Hall thruster discharges. In each example, nonlocal kinetic effects are identified as the main mechanisms responsible for the surprising degree of discharge self-organization. These phenomena include: explosive generation of cold electrons with rf power increase in low-pressure rf discharges; abrupt changes in discharge structure with increased bias voltage on a third electrode in a dc discharge with hot cathode; absence of a steady-state regime in Hall thruster discharges with intense secondary electron emission due to coupling of the sheath properties and the EVDF. In collaboration with Y. Raitses, A.V. Khrabrov, M. Campanell, V. I. Demidov, D. Sydorenko, I. Schweigert, and A. S. Mustafaev. Research supported by the U.S. Department of Energy.

  2. Disparity in academic achievement

    African Journals Online (AJOL)

    User

    female and male students in colleges of teachers' education in Oromia, and to identify variables attributing to ... and social services (Dereje, Dawit & ... related to student attitudes (motivation; .... community commitment to children's ... and getting involved in social and academic .... study, and gender patterns in achievement.

  3. Iowa Women of Achievement.

    Science.gov (United States)

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This issue of the Goldfinch highlights some of Iowa's 20th century women of achievement. These women have devoted their lives to working for human rights, education, equality, and individual rights. They come from the worlds of politics, art, music, education, sports, business, entertainment, and social work. They represent Native Americans,…

  4. Assessing Handwriting Achievement.

    Science.gov (United States)

    Ediger, Marlow

    Teachers in the school setting need to emphasize quality handwriting across the curriculum. Quality handwriting means that the written content is easy to read in either manuscript or cursive form. Handwriting achievement can be assessed, but not compared to the precision of assessing basic addition, subtraction, multiplication, and division facts.…

  5. NCLB: Achievement Robin Hood?

    Science.gov (United States)

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the…

  6. Cognitive Processes and Achievement.

    Science.gov (United States)

    Hunt, Dennis; Randhawa, Bikkar S.

    For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

  7. Cognitive Processes and Achievement.

    Science.gov (United States)

    Hunt, Dennis; Randhawa, Bikkar S.

    For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

  8. NCLB: Achievement Robin Hood?

    Science.gov (United States)

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the…

  9. Plasma density perturbation caused by probes at low gas pressure

    Science.gov (United States)

    Sternberg, Natalia; Godyak, Valery

    2017-09-01

    An analysis of plasma parameter perturbations caused by a spherical probe immersed into a spherical plasma is presented for arbitrary collisionality and arbitrary ratios of probe to plasma dimensions. The plasma was modeled by the fluid plasma equations with ion inertia and nonlinear ion friction force that dominate plasma transport at low gas pressures. Significant depletion of the plasma density around the probe surface has been found. The area of plasma depletion coincides with the sensing area of different kinds of magnetic and microwave probes and will therefore lead to errors in data inferred from measurements with such probes.

  10. Microwave power coupling in a surface wave excited plasma

    CERN Document Server

    Kar, Satyananda; Kousaka, Hiroyuki

    2014-01-01

    In recent decades, different types of plasma sources have been used for various types of plasma processing, such as, etching and thin film deposition. The critical parameter for effective plasma processing is high plasma density. One type of high density plasma source is Microwave sheath-Voltage combination Plasma (MVP). In the present investigation, a better design of MVP source is reported, in which over-dense plasma is generated for low input microwave powers. The results indicate that the length of plasma column increases significantly with increase in input microwave power.

  11. Using Space as a Nonlinear Plasma Laboratory

    Science.gov (United States)

    Papadopoulos, Konstantinos

    2008-11-01

    Ionospheric heaters have been an important tool of plasma physics investigations. The extent that non-linear plasma phenomena can be triggered and observed depends critically on the heater power, its Effective Radiative Power (ERP) and its scanning capability. Increasing these parameters allows us to reach thresholds associated with effects that were not previously observed. The latest entry to ionospheric heating, the HF transmitter associated with the High Frequency Active Ionospheric Research Program (HAARP) was completed in June 2007. The transmitter consists of 180 antenna elements spanning 30.6 acres and can radiate 3.6 MW of HF power (a factor of almost 4 higher than any previous heater) in the 2.8-10.0 MHz range. With increasing frequency the beam-width varies from 15-5 degrees, corresponding to 20-30 dB gain and resulting in ERP between 1-5 GW. The antenna can point to any direction in a cone 30 degrees from the vertical, with reposition time of 15 microseconds resulting in superluminal scanning speeds. The transmitter can synthesize essentially any waveform and transmit any polarization. These capabilities far exceed those of any previous heater and allow for new frontier research in non-linear plasma physics. The presentation will focus first on the relationship of the new capabilities of the facility with thresholds of physical processes that had not been achieved previously. It will then present new spectacular results that have been achieved during the last year. They include whistler injection and amplification, injection of shear and magnetosonic waves in the magnetosphere, Langmuir turbulence, upper hybrid waves and thermal instabilities, electron acceleration, optical emissions and formation of artificial ducts for whistler propagation. The presentation will also discuss future experiments made possible for the first time by the new transmitter capabilities, large bandwidth and high ERP.

  12. Evaluation of Low-Pressure Cold Plasma for Disinfection for ISS Grown Produce and Metallic Instrumentation

    Science.gov (United States)

    Hintze, Paul E.; Franco, Carolina; Hummerick, Mary E.; Maloney, Phillip R.; Spencer, Lashelle E.

    2017-01-01

    Cold plasma (CP) cleaning is a dry, non-thermal process, which can provide broad-spectrum antimicrobial activity yet reportedly causes little to no damage to the object being sanitized. Since cold plasma uses no liquids, it has the distinct advantage when used in microgravity of not having to separate liquids from the item being cleaned. This paper will present results on an effort to use low pressure CP to disinfect or sterilize materials for in space applications. Exposure times from 0 to 60 minutes and pressures ranging from 10 to 100 Pa were used to optimize plasma parameters to achieve acceptable kill rates for 3 bacteria, Bacillus cereus, E. coli and Bacillus pumulis SAFR-32 and one fungi, Aspergillus niger. These tests were done on produce and metal coupons to simulate medical equipment. Produce testing was not successful, with unacceptable kill rates and the produce being negatively impacted by exposure to the plasma. The plasma caused a 5 log reduction in the number of viable bacteria on metal coupon tests, which placed the number of viable bacteria below the detection limit. This is a very promising result showing that sterilization of medical equipment with cold plasma is feasible. Scanning Electron Microscope images were taken before and after exposure. The images after plasma exposure shows that the bacteria spores have been physically affected, as their size has gotten smaller and the appearance has changed.

  13. Effect of wire obstructions on the formation of modulated plasma waveguides

    Science.gov (United States)

    Goers, Andrew; Yoon, Sung; Hine, George; Magill, Jeff; Milchberg, Howard

    2012-10-01

    Modulated plasma waveguides have been proposed as a means of quasi-phase matching laser plasma interactions for applications including direct acceleration of electrons by a high intensity laser pulse. We have demonstrated a technique for axially modulating plasma waveguides by periodically obstructing gas flow out of a cluster jet using an array of wires. This technique is inherently simpler and more easily varied compared to demonstrated optical techniques which axially modulate laser intensity at the target. However, in the previous study [B. Layer, et. al., Opt. Exp. 17, 4263(2009)] the modulation period could not be made less than 200um due to an observed density drop in the plasma between the wires for unknown reasons. By obstructing gas flow with only two wires with variable separation, we examine the aforementioned issue. Since the gas flow out of the cluster jet is supersonic, we observe shock wave formation from the wires with transverse interferometry and shadowgraphy. We find that as we increase the mean cluster size in the gas flow the effect of the shock wave to decrease plasma density between the wires is diminished, representing a transition to a ballistic flow regime. By optimizing jet parameters (e.g. temperature and height of plasma from the wires) we have been able to achieve plasma guiding structures with modulation periods less than 200um.

  14. Research methods of plasma stream interaction with heat-resistant materials

    Science.gov (United States)

    Tyuftyaev, A. S.; Gadzhiev, M. Kh; Sargsyan, M. A.; Chinnov, V. F.; Demirov, N. A.; Kavyrshin, D. I.; Ageev, A. G.; Khromov, M. A.

    2016-11-01

    An experimental automated system was designed and constructed for studying the parameters and characteristics of non-stationary interacting system high-enthalpy-plasma stream-investigated sample: enthalpy of plasma in the incident stream; speed and temperature of plasma stream; temperature of electrons and heavy particles, ionic composition and their spatial distribution; heat flux incident on the sample (kW/cm2); surface temperature of the sample; ablation of the sample material, and others. Measurements of achievable plasma heat flux levels are carried out by calorimetry of plasma streams incident on the surface of multisection copper calorimeter. Determination of acceleration characteristics for profiled plasma torch nozzle, as well as the gas flow rate is produced by measuring the total pressure using the Pitot tube. Video visualization of interacting system is carried out using synchronized high-speed cameras. Micropyrometry of the selected zone on the sample surface is carried out by high-speed, three-wavelength pyrometer. To measure the rate of mass loss of the sample, in addition to the weighing method of evaluation the methods of laser knife and two-position stereoscopy are used. Plasma and sample emission characteristics are performed with two separate spectrometers.

  15. Degradation of triclosan in aqueous solution by dielectric barrier discharge plasma combined with activated carbon fibers.

    Science.gov (United States)

    Xin, Lu; Sun, Yabing; Feng, Jingwei; Wang, Jian; He, Dong

    2016-02-01

    The degradation of triclosan (TCS) in aqueous solution by dielectric barrier discharge (DBD) plasma with activated carbon fibers (ACFs) was investigated. In this study, ACFs and DBD plasma coexisted in a planar DBD plasma reactor, which could synchronously achieve degradation of TCS, modification and in situ regeneration of ACFs, enhancing the effect of recycling of ACFs. The properties of ACFs before and after modification by DBD plasma were characterized by BET and XPS. Various processing parameters affecting the synergetic degradation of TCS were also investigated. The results exhibited excellent synergetic effects in DBD plasma-ACFs system on TCS degradation. The degradation efficiency of 120 mL TCS with initial concentration of 10 mg L(-1) could reach 93% with 1 mm thick ACFs in 18 min at input power of 80 W, compared with 85% by single DBD plasma. Meanwhile, the removal rate of total organic carbon increased from 12% at pH 6.26-24% at pH 3.50. ACFs could ameliorate the degradation efficiency for planar DBD plasma when treating TCS solution at high flow rates or at low initial concentrations. A possible degradation pathway of TCS was investigated according to the detected intermediates, which were identified by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) combined with theoretical calculation of Gaussian 09 program.

  16. Characterization and modeling of multi-dipolar microwave plasmas: application to multi-dipolar plasma assisted sputtering; Caracterisation et modelisation des plasmas micro-onde multi-dipolaires: application a la pulverisation assistee par plasma multi-dipolaire

    Energy Technology Data Exchange (ETDEWEB)

    Tran, T.V

    2006-12-15

    The scaling up of plasma processes in the low pressure range remains a question to be solved for their rise at the industrial level. One solution is the uniform distribution of elementary plasma sources where the plasma is produced via electron cyclotron resonance (ECR) coupling. These elementary plasma sources are made up of a cylindrical permanent magnet (magnetic dipole) set at the end of a coaxial microwave line. Although of simple concept, the optimisation of these dipolar plasma sources is in fact a complex problem. It requires the knowledge, on one hand, of the configurations of static magnetic fields and microwave electric fields, and, on the other hand, of the mechanisms of plasma production in the region of high intensity magnetic field (ECR condition), and of plasma diffusion. Therefore, the experimental characterisation of the operating ranges and plasma parameters has been performed by Langmuir probes and optical emission spectroscopy on different configurations of dipolar sources. At the same time, in a first analytical approach, calculations have been made on simple magnetic field configurations, motion and trajectory of electrons in these magnetic fields, and the acceleration of electrons by ECR coupling. Then, the results have been used for the validation of the numerical modelling of the electron trajectories by using a hybrid PIC (particle-in-cell) / MC (Monte Carlo) method. The experimental study has evidenced large operating domains, between 15 and 200 W of microwave power, and from 0.5 to 15 mtorr argon pressure. The analysis of plasma parameters has shown that the region of ECR coupling is localised near the equatorial plane of the magnet and dependent on magnet geometry. These characterizations, applied to a cylindrical reactor using 48 sources, have shown that densities between 10{sup 11} and 10{sup 12} cm{sup -3} could be achieved in the central part of the volume at a few mtorr argon pressures. The modelling of electron trajectories near

  17. 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....

  18. 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.

  19. Intermittent transport in edge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, O.E.; Naulin, V.; Nielsen, A.H.; Juul Rasmussen, J. [Association EURATOM-Riso National Laboratory, Optics and Plasma Research, Roskilde (Denmark)

    2004-07-01

    The properties of low-frequency convective fluctuations and transport are investigated for the boundary region of magnetized plasmas. We employ a two-dimensional fluid model for the evolution of the global plasma quantities in a geometry and with parameters relevant to the scrape-off layer of confined toroidal plasmas. Strongly intermittent plasma transport is regulated by self-consistently generated sheared poloidal flows and is mediated by burst ejection of particles and heat from the bulk plasma in the form of blobs. Coarse grained probe signals reveal a highly skewed and flat distribution on short time scales, but tends towards a normal distribution at large time scales. Conditionally averaged signals are in perfect agreement with experimental measurements. (authors)

  20. A Multibunch Plasma Wakefield Accelerator

    CERN Document Server

    Kallos, Efthymios; Ben-Zvi, Ilan; Katsouleas, Thomas C; Kimura, Wayne D; Kusche, Karl; Muggli, Patric; Pavlishin, Igor; Pogorelsky, Igor; Yakimenko, Vitaly; Zhou, Feng

    2005-01-01

    We investigate a plasma wakefield acceleration scheme where a train of electron microbunches feeds into a high density plasma. When the microbunch train enters such a plasma that has a corresponding plasma wavelength equal to the microbunch separation distance, a strong wakefield is expected to be resonantly driven to an amplitude that is at least one order of magnitude higher than that using an unbunched beam. PIC simulations have been performed using the beamline parameters of the Brookhaven National Laboratory Accelerator Test Facility operating in the configuration of the STELLA inverse free electron laser (IFEL) experiment. A 65 MeV electron beam is modulated by a 10.6 um CO2 laser beam via an IFEL interaction. This produces a train of ~90 microbunches separated by the laser wavelength. In this paper, we present both a simple theoretical treatment and simulation results that demonstrate promising results for the multibunch technique as a plasma-based accelerator.

  1. The study of helicon plasma source.

    Science.gov (United States)

    Miao, Ting-Ting; Zhao, Hong-Wei; Liu, Zhan-Wen; Shang, Yong; Sun, Liang-Ting; Zhang, Xue-Zhen; Zhao, Huan-Yu

    2010-02-01

    Helicon plasma source is known as efficient generator of uniform and high density plasma. A helicon plasma source was developed for investigation of plasma neutralization and plasma lens in the Institute of Modern Physics in China. In this paper, the characteristics of helicon plasma have been studied by using Langmuir four-probe and a high argon plasma density up to 3.9x10(13) cm(-3) have been achieved with the Nagoya type III antenna at the conditions of the magnetic intensity of 200 G, working gas pressure of 2.8x10(-3) Pa, and rf power of 1200 W with a frequency of 27.12 MHz. In the experiment, the important phenomena have been found: for a given magnetic induction intensity, the plasma density became greater with the increase in rf power and tended to saturation, and the helicon mode appeared at the rf power between 200 and 400 W.

  2. Plasma immersion ion implantation for reducing metal ion release

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, C.; Garcia, J. A.; Maendl, S.; Pereiro, R.; Fernandez, B.; Rodriguez, R. J. [Centro de Ingenieria Avanzada de Superficies AIN, 31191, Cordovilla-Pamplona (Spain); Leibniz-Institut fuer Oberflaechenmodifizierung, 04318 Leipzig (Germany); Universidad de Oviedo, Departamento Quimica Fisica y Analitica (Spain); Centro de Ingenieria Avanzada de Superficies AIN, 31191, Cordovilla-Pamplona (Spain)

    2012-11-06

    Plasma immersion ion implantation of Nitrogen and Oxygen on CoCrMo alloys was carried out to improve the tribological and corrosion behaviors of these biomedical alloys. In order to optimize the implantation results we were carried experiments at different temperatures. Tribocorrosion tests in bovine serum were used to measure Co, Cr and Mo releasing by using Inductively Coupled Plasma Mass Spectrometry analysis after tests. Also, X-ray Diffraction analysis were employed in order to explain any obtained difference in wear rate and corrosion tests. Wear tests reveals important decreases in rate of more than one order of magnitude for the best treatment. Moreover decreases in metal release were found for all the implanted samples, preserving the same corrosion resistance of the unimplanted samples. Finally this paper gathers an analysis, in terms of implantation parameters and achieved properties for industrial implementation of these treatments.

  3. 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.

  4. 组合激光脉冲激发的等离子体尾场的参数研究∗%Parameter Study of a Plasma Wakefield Driven by Combined Laser Pulses

    Institute of Scientific and Technical Information of China (English)

    西日艾·买买提; 沙依甫加马力·达吾来提; 谢柏松

    2015-01-01

    Electron acceleration in the first cycle of a plasma wakefield driven by combined two laser pulses with different intensity and pulse duration is investigated analytically and numerically. It is found that the combined laser pulses can efficiently modify the plasma wakefield potential and phase portrait of the electron dynamics. The optimum combination of two laser pulses to maximize the net energy gain of the accelerated electrons is discussed.%本文通过数值和解析方法分析了对称强激光脉冲和弱激光脉冲的前后结合所形成的混合激光激发的尾场的参数对尾场势的影响。讨论了在弱脉冲的位置有所改动的条件下,尾场最大和最小势随各激光脉冲参数变化的敏感度。

  5. Radiation reaction in fusion plasmas.

    Science.gov (United States)

    Hazeltine, R D; Mahajan, S M

    2004-10-01

    The effects of a radiation reaction on thermal electrons in a magnetically confined plasma, with parameters typical of planned burning plasma experiments, are studied. A fully relativistic kinetic equation that includes the radiation reaction is derived. The associated rate of phase-space contraction is computed and the relative importance of the radiation reaction in phase space is estimated. A consideration of the moments of the radiation reaction force show that its effects are typically small in reactor-grade confined plasmas, but not necessarily insignificant.

  6. Achieveing Organizational Excellence Through

    Directory of Open Access Journals (Sweden)

    Mehdi Abzari

    2009-04-01

    Full Text Available AbstractToday, In order to create motivation and desirable behavior in employees, to obtain organizational goals,to increase human resources productivity and finally to achieve organizational excellence, top managers oforganizations apply new and effective strategies. One of these strategies to achieve organizational excellenceis creating desirable corporate culture. This research has been conducted to identify the path to reachorganizational excellence by creating corporate culture according to the standards and criteria oforganizational excellence. The result of the so-called research is this paper in which researchers foundtwenty models and components of corporate culture and based on the Industry, organizational goals andEFQM model developed a model called "The Eskimo model of Culture-Excellence". The method of theresearch is survey and field study and the questionnaires were distributed among 116 managers andemployees. To assess the reliability of questionnaires, Cronbach alpha was measured to be 95% in the idealsituation and 0/97 in the current situation. Systematic sampling was done and in the pre-test stage 45questionnaires were distributed. A comparison between the current and the ideal corporate culture based onthe views of managers and employees was done and finally it has been concluded that corporate culture isthe main factor to facilitate corporate excellence and success in order to achieve organizational effectiveness.The contribution of this paper is that it proposes a localized –applicable model of corporate excellencethrough reinforcing corporate culture.

  7. Dissipative nonlinear structures in tokamak plasmas

    Directory of Open Access Journals (Sweden)

    K. A. Razumova

    2001-01-01

    Full Text Available A lot of different kinds of instabilities may be developed in high temperature plasma located in a strong toroidal magnetic field (tokamak plasma. Nonlinear effects in the instability development result in plasma self-organization. Such plasma has a geometrically complicated configuration, consisting of the magnetic surfaces imbedded into each other and split into islands with various characteristic numbers of helical twisting. The self-consistency of the processes means that the transport coefficients in plasma do not depend just on the local parameters, being a function of the whole plasma configuration and of the forces affecting it. By disrupting the bonds between separate magnetic surfaces filled with islands, one can produce zones of reduced transport in the plasma, i.e. “internal thermal barriers”, allowing one essentially to increase the plasma temperature and density.

  8. 大气压冷等离子体提高乙醇转化率的实验参数优化研究%Optimization of Experimental Parameters for Improved Ethanol Yield by Cold Plasma at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    董晓宇; 王萧; 刘超; 刘庆平; 冯宝民

    2012-01-01

    Process conditions were investigated to improve ethanol yield in Saccharomyces cerevisiae by cold plasma at atmospheric pressure. According to single factor investigation, a mathematical model was established using Box-Behnken central composite experimental design, with treated time of plasma discharge, supply voltage, and treated volume of cell suspension as the impact factors and with ethanol yield as their response. This was followed by response surface analysis. It was found that the optimal process conditions for enhanced ethanol yield in Saccharomyces cerevisiae by plasma discharge were as follows: treated time 1 min, supply voltage 24 V, treated volume of cell suspension 9 mL, and that the resultant ethanol yield was 0.58 g/g with an increase of 23.6% compared to the control.%以酿酒酵母(Saccharomycescerevisiae)为研究对象,研究大气压冷等离子体激活酿酒酵母提高乙醇转化率的工艺条件。在单因素实验基础上,选取等离子体处理时间、等离子体电源电压和处理菌液体积为影响因子,以乙醇转化率为响应值,应用Box.Behnken中心组合实验建立数学模型,进行响应面分析。结果表明,大气压冷等离子体提高乙醇转化率的最佳实验参数为:处理时间1min,电源电压24V,处理菌液体积9mL。在此条件下,乙醇转化率达到O.58g/g,比未处理过的酿酒酵母发酵葡萄糖生成乙醇的转化率高23.6%。

  9. EM wave propagation analysis in plasma covered radar absorbing material

    CERN Document Server

    Singh, Hema; Rawat, Harish Singh

    2017-01-01

    This book focuses on EM propagation characteristics within multilayered plasma-dielectric-metallic media. The method used for analysis is impedance transformation method. Plasma covered radar absorbing material is approximated as a multi-layered dielectric medium. The plasma is considered to be bounded homogeneous/inhomogeneous medium. The reflection coefficient and hence return loss is analytically derived. The role of plasma parameters, such as electron density, collision frequency, plasma thickness, and plasma density profile in the absorption behavior of multi-layered plasma-RAM structure is described. This book provides a clearer picture of EM propagation within plasma. The reader will get an insight of plasma parameters that play significant role in deciding the absorption characteristics of plasma covered surfaces.

  10. Optimization of ECR-breakdown and plasma discharge formation on T-10 tokamak, using X-mode second harmonic of ECR.

    Directory of Open Access Journals (Sweden)

    Roy I.

    2012-09-01

    Full Text Available In order to obtain breakdown and suitable plasma parameters for low-voltage OH start-up, high level of EC-power was injected into T-10 tokamak. Input HF-power was varied in the range of 0.15–1.0 MW. Two HF-launcher systems with different output beams allowed to inject EC-waves with maximum power density 0.25 MW/cm2 and 0.01 MW/cm2. Dependence of breakdown time delay on HF-power was obtained. It was shown, that optimal plasma parameters were achieved in presence of plasma equilibrium currents I=3 kA (input HF-power=1.0 MW. Electron temperature Te=100÷150 eV and electron density ne=5·1012 cm−3 was measured in these discharges. These parameters remained constant during full HF-pulse-length.

  11. Performance of a Discrete Wavelet Transform for Compressing Plasma Count Data and its Application to the Fast Plasma Investigation on NASA's Magnetospheric Multiscale Mission

    Science.gov (United States)

    Barrie, Alexander C.; Yeh, Penshu; Dorelli, John C.; Clark, George B.; Paterson, William R.; Adrian, Mark L.; Holland, Matthew P.; Lobell, James V.; Simpson, David G.; Pollock, Craig J.; hide

    2015-01-01

    Plasma measurements in space are becoming increasingly faster, higher resolution, and distributed over multiple instruments. As raw data generation rates can exceed available data transfer bandwidth, data compression is becoming a critical design component. Data compression has been a staple of imaging instruments for years, but only recently have plasma measurement designers become interested in high performance data compression. Missions will often use a simple lossless compression technique yielding compression ratios of approximately 2:1, however future missions may require compression ratios upwards of 10:1. This study aims to explore how a Discrete Wavelet Transform combined with a Bit Plane Encoder (DWT/BPE), implemented via a CCSDS standard, can be used effectively to compress count information common to plasma measurements to high compression ratios while maintaining little or no compression error. The compression ASIC used for the Fast Plasma Investigation (FPI) on board the Magnetospheric Multiscale mission (MMS) is used for this study. Plasma count data from multiple sources is examined: resampled data from previous missions, randomly generated data from distribution functions, and simulations of expected regimes. These are run through the compression routines with various parameters to yield the greatest possible compression ratio while maintaining little or no error, the latter indicates that fully lossless compression is obtained. Finally, recommendations are made for future missions as to what can be achieved when compressing plasma count data and how best to do so.

  12. Study of the feasibility of distributed cathodic arc as a plasma source for development of the technology for plasma separation of SNF and radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Amirov, R. Kh.; Vorona, N. A.; Gavrikov, A. V.; Liziakin, G. D.; Polistchook, V. P.; Samoylov, I. S.; Smirnov, V. P.; Usmanov, R. A., E-mail: ravus46@yandex.ru; Yartsev, I. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-12-15

    One of the key problems in the development of plasma separation technology is designing a plasma source which uses condensed spent nuclear fuel (SNF) or nuclear wastes as a raw material. This paper covers the experimental study of the evaporation and ionization of model materials (gadolinium, niobium oxide, and titanium oxide). For these purposes, a vacuum arc with a heated cathode on the studied material was initiated and its parameters in different regimes were studied. During the experiment, the cathode temperature, arc current, arc voltage, and plasma radiation spectra were measured, and also probe measurements were carried out. It was found that the increase in the cathode heating power leads to the decrease in the arc voltage (to 3 V). This fact makes it possible to reduce the electron energy and achieve singly ionized plasma with a high degree of ionization to fulfill one of the requirements for plasma separation of SNF. This finding is supported by the analysis of the plasma radiation spectrum and the results of the probe diagnostics.

  13. Towards highly stable aqueous dispersions of multi-walled carbon nanotubes: the effect of oxygen plasma functionalization.

    Science.gov (United States)

    Garzia Trulli, Marta; Sardella, Eloisa; Palumbo, Fabio; Palazzo, Gerardo; Giannossa, Lorena Carla; Mangone, Annarosa; Comparelli, Roberto; Musso, Simone; Favia, Pietro

    2017-04-01

    In order to improve the dispersion of multi-walled carbon nanotubes (MWCNTs) in aqueous media, their surface functionalization was carried out in O2-fed low-pressure plasmas. Differently from what can be found in the literature of this field, homogeneous functionalization was achieved by generating the plasma inside vials containing the nanotube powders properly stirred. Experimental parameters, such as input power, treatment time and pressure, were varied to investigate their influence on the process efficiency. A detailed characterization of the plasma treated nanotubes, dry and in aqueous suspension, was carried out with a multi-diagnostic analytical approach, to evaluate their surface chemical properties, morphology, structural integrity and stability in the colloidal state. The plasma grafting of polar ionizable (e.g. acid) groups has been proved to successfully limit the agglomeration of MWCNTs and to produce nanotubes suspensions that are stable for one month and more in water.

  14. Outlook for the use of microsecond plasma opening switches to generate high-power nanosecond current pulses

    Science.gov (United States)

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

    2006-12-01

    An analysis is made of the current break process in microsecond plasma opening switches and their possible application in high-current generators. Necessary conditions are determined for generating megavolt pulses in the erosion mode of a plasma opening switch with the gap insulated by an external magnetic field. Under these conditions, efficient sharpening of high-power submegampere current pulses can be achieved. The possibility of using plasma opening switches operating at voltages of 5 6 MV to generate X-ray and gamma emission is discussed. The main operating and design parameters of a six-module plasma opening switch with a current pulse amplitude of 3.7 MA and voltage of 4 6 MV for use in the MOL generator, which is the prototype of one of the 24 modules of the projected Baikal multimegajoule generator, are estimated by using the available scalings.

  15. Plasma treatment of crane rails

    Directory of Open Access Journals (Sweden)

    Владислав Олександрович Мазур

    2016-07-01

    Full Text Available Crane operation results in wear and tear of rails and crane wheels. Renovation and efficiency of these details is therefore relevant. Modern technologies of wheels and rails restoration use surfacing or high-frequency currents treatment. Surface treatment with highly concentrated streams of energy- with a laser beam, plasma jet- is a promising direction.. It is proposed to increase the efficiency of crane rails by means of surface plasma treatment. The modes of treatment have been chosen.. Modelling of plasma jet thermal impact on a solid body of complex shape has been made. Plasma hardening regimes that meet the requirements of production have been defined. Structural transformation of the material in the crane rails on plasma treatment has been investigated. It has been concluded that for carbon and low alloy crane steels the plasma exposure zone is characterized by a high degree of hardened structure dispersion and higher hardness as compared to the hardness after high-frequency quenching. As this takes place phase transformations are both shift (in the upper zone of plasma influence and fluctuation (in the lower zone of the plasma. With high-speed plasma heating granular or lamellar pearlite mainly transforms into austenite. The level of service characteristics of hardened steel, which is achieved in this case is determined by the kinetics and completeness of pearlite → austenite transformation. For carbon and low alloy rail steels plasma hardening can replace bulk hardening, hardening by high-frequency currents, or surfacing. The modes for plasma treatment which make it possible to obtain a surface layer with a certain service characteristics have been defined

  16. The 2012 Plasma Roadmap

    Science.gov (United States)

    Samukawa, Seiji; Hori, Masaru; Rauf, Shahid; Tachibana, Kunihide; Bruggeman, Peter; Kroesen, Gerrit; Whitehead, J. Christopher; Murphy, Anthony B.; Gutsol, Alexander F.; Starikovskaia, Svetlana; Kortshagen, Uwe; Boeuf, Jean-Pierre; Sommerer, Timothy J.; Kushner, Mark J.; Czarnetzki, Uwe; Mason, Nigel

    2012-06-01

    Low-temperature plasma physics and technology are diverse and interdisciplinary fields. The plasma parameters can span many orders of magnitude and applications are found in quite different areas of daily life and industrial production. As a consequence, the trends in research, science and technology are difficult to follow and it is not easy to identify the major challenges of the field and their many sub-fields. Even for experts the road to the future is sometimes lost in the mist. Journal of Physics D: Applied Physics is addressing this need for clarity and thus providing guidance to the field by this special Review article, The 2012 Plasma Roadmap. Although roadmaps are common in the microelectronic industry and other fields of research and development, constructing a roadmap for the field of low-temperature plasmas is perhaps a unique undertaking. Realizing the difficulty of this task for any individual, the plasma section of the Journal of Physics D Board decided to meet the challenge of developing a roadmap through an unusual and novel concept. The roadmap was divided into 16 formalized short subsections each addressing a particular key topic. For each topic a renowned expert in the sub-field was invited to express his/her individual visions on the status, current and future challenges, and to identify advances in science and technology required to meet these challenges. Together these contributions form a detailed snapshot of the current state of the art which clearly shows the lifelines of the field and the challenges ahead. Novel technologies, fresh ideas and concepts, and new applications discussed by our authors demonstrate that the road to the future is wide and far reaching. We hope that this special plasma science and technology roadmap will provide guidance for colleagues, funding agencies and government institutions. If successful in doing so, the roadmap will be periodically updated to continue to help in guiding the field.

  17. The plasma focus as a tool for plasma-wall-interaction studies

    Science.gov (United States)

    Ramos, G.; Martinez, M.; Herrera, J. J. E.; Castillo, F.

    2015-03-01

    The study of the interaction of magnetized plasmas with candidate materials for fusion reactors, as for example tungsten, is a main topic in fusion research. Many studies simulate the plasma wall interaction using ion beams, while only a few use plasma simulators. Plasma foci can produce dense magnetized plasmas of deuterium and helium among other species. We used the plasma focus Fuego-Nuevo II, to expose tungsten samples to deuterium and helium plasmas. The samples were analysed by means of SEM, RBS and NRA, evidencing surface erosion, surface melting and retention of deuterium in a shallow surface layer of 250 nm amounting 6.5·1016 D/cm2. The plasma temperature has been measured at the position of the samples using a triple Langmuir probe and compared to calculations of a snowplow model. The modelling of the electrode to reach desired plasma parameters is discussed.

  18. Plasma metallization

    CERN Document Server

    Crowther, J M

    1997-01-01

    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 s...

  19. Active plasma resonance spectroscopy: A functional analytic description

    OpenAIRE

    Lapke, Martin; Oberrath, Jens; Mussenbrock, Thomas; Brinkmann, Ralf Peter

    2012-01-01

    The term "Active Plasma Resonance Spectroscopy" refers to a class of diagnostic methods which employ the ability of plasmas to resonate on or near the plasma frequency. The basic idea dates back to the early days of discharge physics: An signal in the GHz range is coupled to the plasma via an electrical probe; the spectral response is recorded, and then evaluated with a mathematical model to obtain information on the electron density and other plasma parameters. In recent years, the concept h...

  20. Plasma preparation and storage for African elephants (Loxodonta africana).

    Science.gov (United States)

    Knauf, Sascha; Blad-Stahl, Julia; Lawrenz, Arne; Schuerer, Ulrich; Wehrend, Axel

    2009-03-01

    The use of plasma as a life-saving tool for neonatal African elephants (Loxodonta africana) that failed passive transfer of immunoglobulins is proposed. The methodology of blood sampling, plasma extraction, and plasma storage is described. Values for cellular component sedimentation and biochemical parameters of extracted plasma that was collected from 2 female elephants is presented. The proposal for a central plasma bank for elephants in European zoos is suggested.

  1. Formation of imploding plasma liners for fundamental HEDP studies and MIF Standoff Driver Concept

    Energy Technology Data Exchange (ETDEWEB)

    Cassibry, Jason [Univ. of AL in Huntsville; Hatcher, Richard [Univ. of AL in Huntsville; Stanic, Milos [Univ. of AL in Huntsville

    2013-08-17

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

  2. Achieving form in autobiography

    Directory of Open Access Journals (Sweden)

    Nicholas (Nick Meihuizen

    2014-06-01

    Full Text Available This article argues that, unlike biographies which tend to follow patterns based on conventional expectations, salient autobiographies achieve forms unique to themselves. The article draws on ideas from contemporary formalists such as Peter McDonald and Angela Leighton but also considers ideas on significant form stemming from earlier writers and critics such as P.N. Furbank and Willa Cather. In extracting from these writers the elements of what they consider comprise achieved form, the article does not seek to provide a rigid means of objectively testing the formal attributes of a piece of writing. It rather offers qualitative reminders of the need to be alert to the importance of form, even if the precise nature of this importance is not possible to define. Form is involved in meaning, and this continuously opens up possibilities regarding the reader’s relationship with the work in question. French genetic critic Debray Genette distinguishes between ‘semantic effect’ (the direct telling involved in writing and ‘semiological effect’ (the indirect signification involved. It is the latter, the article argues in summation, which gives a work its singular nature, producing a form that is not predictable but suggestive, imaginative.

  3. Plasma dynamo

    CERN Document Server

    Rincon, F; Schekochihin, A A; Valentini, F

    2015-01-01

    Magnetic fields pervade the entire Universe and, through their dynamical interactions with matter, affect the formation and evolution of astrophysical systems from cosmological to planetary scales. How primordial cosmological seed fields arose and were further amplified to $\\mu$Gauss levels reported in nearby galaxy clusters, near equipartition with kinetic energy of plasma motions and on scales of at least tens of kiloparsecs, is a major theoretical puzzle still largely unconstrained by observations. Extragalactic plasmas are weakly collisional (as opposed to collisional magnetohydrodynamic fluids), and whether magnetic-field growth and its sustainment through an efficient dynamo instability driven by chaotic motions is possible in such plasmas is not known. Fully kinetic numerical simulations of the Vlasov equation in a six-dimensional phase space necessary to answer this question have until recently remained beyond computational capabilities. Here, we show by means of such simulations that magnetic-field a...

  4. Extension and its characteristics of ECRH plasma in the LHD

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Notake, T.; Inagaki, S.; Yokoyama, M.; Ohkubo, K.; Kumazawa, R.; Nakamura, Y.; Saito, K.; Seki, T.; Mutoh, T.; Watari, T.; Narihara, K.; Yamada, I.; Ida, K.; Takeiri, Y.; Funaba, H.; Ohyabu, N.; Kawahata, K.; Kaneko, O.; Yamada, H.; Itoh, K.; Ashikawa, N.; Emoto, M.; Goto, M.; Hamada, Y.; Ido, T.; Ikeda, K.; Isobe, M.; Khlopenkov, K.; Kobuchi, T.; Masuzaki, S.; Minami, T.; Miyazawa, J.; Morisaki, T.; Morita, S.; Muto, S.; Nagaoka, K.; Nagayama, Y.; Nakanishi, H.; Narushima, Y.; Nishimura, K.; Nishiura, M.; Noda, N.; Ohdachi, S.; Oka, Y.; Osakabe, M.; Ozaki, T.; Peterson, B.J.; Sagara, A.; Sakakibara, S.; Sakamoto, R.; Shoji, M.; Sudo, S.; Takeuchi, N.; Tamura, N.; Tanaka, K.; Toi, K.; Tokuzawa, T.; Tsumori, K.; Watanabe, K.; Watanabe, T.; Yamazaki, K.; Yoshinuma, M.; Komori, A.; Motojima, O. [National Institute for Fusion Science, Toki, Gifu (Japan); Idei, H. [Advanced Fusion Research Center, Research Institute for Applied Mechanics, Kyushu University, Kasuga (Japan); Murakami, S. [Kyoto Univ., Dept. of Nuclear Engineering, Kyoto (Japan)

    2004-07-01

    One of the main objectives of the large helical device (LHD) is to extend the plasma confinement database for helical systems and to demonstrate such extended plasma confinement properties to be sustained in steady state. Among the various plasma parameter regimes, the study of confinement properties in the collisionless regime is of particular importance. Electron cyclotron resonance heating (ECRH) has been extensively used for these confinement studies of the LHD plasma from the initial operation. The system optimizations including the modification of the transmission and antenna system are performed with the special emphasis on the local heating properties. As the result, central electron temperature of more than 10 keV with the electron density of 0.6 x 10{sup 19} m{sup -3} is achieved near the magnetic axis. The electron temperature profile is characterized by a steep gradient similar to those of an internal transport barrier observed in tokamaks and stellarators. 168 GHz ECRH system demonstrated efficient heating at over the density more than 1.0 x 10{sup 20} m{sup -3}. CW ECRH system is successfully operated to sustain 756 second long discharge. (authors)

  5. Application of an impedance matching transformer to a plasma focus.

    Science.gov (United States)

    Bures, B L; James, C; Krishnan, M; Adler, R

    2011-10-01

    A plasma focus was constructed using an impedance matching transformer to improve power transfer between the pulse power and the dynamic plasma load. The system relied on two switches and twelve transformer cores to produce a 100 kA pulse in short circuit on the secondary at 27 kV on the primary with 110 J stored. With the two transformer systems in parallel, the Thevenin equivalent circuit parameters on the secondary side of the driver are: C = 10.9 μF, V(0) = 4.5 kV, L = 17 nH, and R = 5 mΩ. An equivalent direct drive circuit would require a large number of switches in parallel, to achieve the same Thevenin equivalent. The benefits of this approach are replacement of consumable switches with non-consumable transformer cores, reduction of the driver inductance and resistance as viewed by the dynamic load, and reduction of the stored energy to produce a given peak current. The system is designed to operate at 100 Hz, so minimizing the stored energy results in less load on the thermal management system. When operated at 1 Hz, the neutron yield from the transformer matched plasma focus was similar to the neutron yield from a conventional (directly driven) plasma focus at the same peak current.

  6. 高气压空气环状感性耦合等离子体实验研究和参数诊断∗%Exp erimental investigation and parameter diagnosis of air high-pressure ring-shap ed inductively coupled plasma

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The variable parameters like electron destiny (ne), electron collision frequency, covered-area and thickness have been regarded as the key factors for the electromagnetic scattering characteristics of the covering target. Therefore, an air inductively coupled plasma (ICP) generator of all-quartz chamber of 20 cm × 20 cm × 7 cm without magnetic confinement and grounded metal surface of substantial area is designed and conducted to study the discharge process and diagnose the parameters in this paper. The shape, E-H mode transition, and structure of inductively coupled plasma are observed, and the width and thickness change due to change of power and pressure are measured in experiments. Results show that the plasma is nearly uniformly full of the chamber in E-mode, while the shape of plasma rapidly changes to a ring in H-mode and the structure of inductively coupled plasma stratified into an electronegative core and an electropositive halo. It is observed clearly that the luminance of plasma increases slowly with the RF power in E-mode, but increases significantly in H-mode, which are proved through the relative spectral intensity variation of nitrogen 337.1 nm spectral lines due to the change of power and pressure. The width and thickness of the core region increase significantly with power, while decrease apparently with increasing pressure, which could be logically explained by the variation of RF magnetic induction amplitude distribution with power and by the theoretical diffusion analyses of electronegative gas. Since a mass of oxygen electronegative ion exists in the air inductively coupled plasma, the electron density (ne) diffusion models are different for the electronegative core and the electropositive halo. It is proved also by the theoretical drift-diffusion analyses that the electron density is distributed nearly uniformly in the electronegative core and decreased sharply in the electropositive halo. The model of electromagnetic wave propagation in

  7. Plasma medicine

    CERN Document Server

    Fridman, Alexander

    2012-01-01

    This comprehensive text is suitable for researchers and graduate students of a 'hot' new topic in medical physics. Written by the world's leading experts,  this book aims to present recent developments in plasma medicine, both technological and scientific, reviewed in a fashion accessible to the highly interdisciplinary audience consisting of doctors, physicists, biologists, chemists and other scientists, university students and professors, engineers and medical practitioners. The book focuses on major topics and covers the physics required to develop novel plasma discharges relevant for medic

  8. Surface plasma source with saddle antenna radio frequency plasma generator.

    Science.gov (United States)

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  9. Achievement report for fiscal 1999 on project for supporting the formation of energy/environmental technology verification project. International joint verification research project (Verification project relative to ignition and NOx reduction using plasma sub-burner in pulverized coal-fired furnace); 1999 nendo plasma sabubana ni yoru bifuntan nenshoro ni okeru chakka oyobi NO{sub x} teigen gijutsu ni kansuru jissho project seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This project is executed through the cooperation of a Russian research institute, Akita Prefectural University, and the Ishikawajima-Harima Heavy Industries Co., Ltd. In the development of a plasma sub-burner and the basic research for its verification, a pulverized coal burning plasma sub-burner is designed and fabricated, a basic burning experiment is conducted for the plasma sub-burner, and plasma stabilization in a pulverized coal flow is simulated. In the verification study of the ignition by the plasma sub-burner in a pulverized coal-fired furnace, it is found that the newly-developed plasma sub-burner satisfies the prescribed operating conditions in the system and that the ignition of pulverized coal takes place across the air ratio range of 0.5-1.5 when pulverized coal is fed to the sub-burner. It is also found that NOx is reduced a great deal when a plasma operating on an orifice gas of air or nitrogen is generated in a gas which contains NOx. (NEDO)

  10. Investigation of Atmospheric Plasma Discharge and Its Application to Surface Modification of Textile Materials

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao-liang; QIU Gao; FENG Xian-ping; YAN Yong-hui; SHI Yun-cheng; YAN Zhi-ren; WANG Liang

    2005-01-01

    In this paper, an improved quasi-stable atmospheric pressure dielectric barrier discharge (DBD) plasma source is achieved after carefully controlled discharge voltage and current, discharge power, working gas, treatment period,and gap between the electrodes. This plasma source has been used to modify the surface of Polybutylene Terephthalate (PBT) melt-blown nonwovens and Polyester(PET) fabrics, and the various influences on surface modification and the aging effeet of treated polymeric materials have been systematically investigated. In addition, the method of spectrum analysis is also used for diagnosing plasma parameters such as electron temperature.Experimental results indicate that both the wettablity and permeation of treated PBT melt-blown nonwovens and dyeing ability of treated PET fabrics are certainly improved.

  11. Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

    Science.gov (United States)

    Kan, C. W.; Kwong, C. H.; Ng, S. P.

    2015-08-01

    Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

  12. One-way helical electromagnetic wave propagation supported by magnetized plasma

    CERN Document Server

    Yang, Biao; Gao, Wenlong; Guo, Qinghua; Zhang, Shuang

    2014-01-01

    In this paper we reveal the presence of photonic one-way helical surface states in a simple natural system - magnetized plasma. The application of an external magnetic field to a bulk plasma body not only breaks time-reversal-symmetry but also leads to separation of Equi-Frequency Contour surfaces (EFCs) to form topologically nontrivial gaps in k space. Interestingly, these EFCs support topologically protected surface states. We numerically investigate an interface between magnetized plasma, using a realistic model for parameter dispersion, and vacuum, to confirm the existence of one-way scatter-immune helical surface states. Unlike previous proposals for achieving photonic one-way propagation, our scheme does not require the use of artificial structures and should therefore be simple to implement experimentally.

  13. 2-D viscous magnetohydrodynamics simulation of plasma armatures with the CE/SE method

    Institute of Scientific and Technical Information of China (English)

    LI Xin; WENG ChunSheng

    2009-01-01

    A possible two-dimensional viscous magnetohydrodynamics (MHD) model is applied to investigating the plasma armature in a railgun. The space-time conservation element and solution element (CE/SE) method for solving the coupled Navier-Stokes equations and Maxwell equations was devised. The dis-tributions of physical parameters of the plasma may thus be evaluated. The results show that extremely high pressure can always be observed ahead of the projectile, and the Lorentz force is the main pro-puIsion. The distribution of temperature is in a good agreement with the results predicted by the law of radiation at the boundaries. Due to convection, the circulation patterns of velocity are evident in both the cases considering inviscid and viscous effect. Furthermore, the velocity and acceleration oscillate over time until a new steady state is achieved. This model efficiently captures the salient features of the physical phenomena, and contributes to further studies of MHD problems in plasma armature.

  14. Polymorphous silicon thin films produced in dusty plasmas: application to solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Roca i Cabarrocas, Pere; Chaabane, N; Kharchenko, A V; Tchakarov, S [Laboratoire de Physique des Interfaces et des Couches Minces (UMR 7647), Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2004-12-01

    We summarize our current understanding of the optimization of PIN solar cells produced by plasma enhanced chemical vapour deposition from silane-hydrogen mixtures. To increase the deposition rate, the discharge is operated under plasma conditions close to powder formation, where silicon nanocrystals contribute to the deposition of so-called polymorphous silicon thin films. We show that the increase in deposition rate can be achieved via an accurate control of the plasma parameters. However, this also results in a highly defective interface in the solar cells due to the bombardment of the P-layer by positively charged nanocrystals during the deposition of the I-layer. We show that decreasing the ion energy by increasing the total pressure or by using silane-helium mixtures allows us to increase both the deposition rate and the solar cells efficiency, as required for cost effective thin film photovoltaics.

  15. Polymorphous silicon thin films produced in dusty plasmas: application to solar cells

    Science.gov (United States)

    Cabarrocas, Pere Roca i.; Chaâbane, N.; Kharchenko, A. V.; Tchakarov, S.

    2004-12-01

    We summarize our current understanding of the optimization of PIN solar cells produced by plasma enhanced chemical vapour deposition from silane hydrogen mixtures. To increase the deposition rate, the discharge is operated under plasma conditions close to powder formation, where silicon nanocrystals contribute to the deposition of so-called polymorphous silicon thin films. We show that the increase in deposition rate can be achieved via an accurate control of the plasma parameters. However, this also results in a highly defective interface in the solar cells due to the bombardment of the P-layer by positively charged nanocrystals during the deposition of the I-layer. We show that decreasing the ion energy by increasing the total pressure or by using silane helium mixtures allows us to increase both the deposition rate and the solar cells efficiency, as required for cost effective thin film photovoltaics.

  16. Achieving English Spoken Fluency

    Institute of Scientific and Technical Information of China (English)

    王鲜杰

    2000-01-01

    Language is first and foremost oral,spoken language,speaking skill is the most important one of the four skills(L,S,R,W)and also it is the most difficult one of the four skills. To have an all-round command of a language one must be able to speak and to understand the spoken language, it is not enough for a language learner only to have a good reading and writing skills. As Englisn language teachers, we need to focus on improving learners' English speaking skill to meet the need of our society and our country and provide learner some useful techniques to achieving their English spoken fluency. This paper focuses on the spoken how to improving learners speaking skill.

  17. Achieving diagnosis by consensus

    LENUS (Irish Health Repository)

    Kane, Bridget

    2009-08-01

    This paper provides an analysis of the collaborative work conducted at a multidisciplinary medical team meeting, where a patient’s definitive diagnosis is agreed, by consensus. The features that distinguish this process of diagnostic work by consensus are examined in depth. The current use of technology to support this collaborative activity is described, and experienced deficiencies are identified. Emphasis is placed on the visual and perceptual difficulty for individual specialities in making interpretations, and on how, through collaboration in discussion, definitive diagnosis is actually achieved. The challenge for providing adequate support for the multidisciplinary team at their meeting is outlined, given the multifaceted nature of the setting, i.e. patient management, educational, organizational and social functions, that need to be satisfied.

  18. Recognizing outstanding achievements

    Science.gov (United States)

    Speiss, Fred

    One function of any professional society is to provide an objective, informed means for recognizing outstanding achievements in its field. In AGU's Ocean Sciences section we have a variety of means for carrying out this duty. They include recognition of outstanding student presentations at our meetings, dedication of special sessions, nomination of individuals to be fellows of the Union, invitations to present Sverdrup lectures, and recommendations for Macelwane Medals, the Ocean Sciences Award, and the Ewing Medal.Since the decision to bestow these awards requires initiative and judgement by members of our section in addition to a deserving individual, it seems appropriate to review the selection process for each and to urge you to identify those deserving of recognition.

  19. Determination of olanzapine and N-desmethyl-olanzapine in plasma using a reversed-phase HPLC coupled with coulochemical detection: correlation of olanzapine or N-desmethyl-olanzapine concentration with metabolic parameters.

    Directory of Open Access Journals (Sweden)

    Mong-Liang Lu

    Full Text Available BACKGROUND: Olanzapine (OLZ is one of the most prescribed atypical antipsychotic drugs but its use is associated with unfavorable metabolic abnormalities. N-desmethyl-olanzapine (DMO, one of the OLZ metabolites by CYP1A2, has been reported to have a normalizing action on metabolic abnormalities, but this remains unclear. Our aim was to explore the correlation between the concentrations of OLZ or DMO with various metabolic parameters in schizophrenic patients. METHODS: The chromatographic analysis was carried out with a solvent delivery system coupled to a Coulochem III coulometric detector to determine OLZ and DMO simultaneously in OLZ-treated patients. The correlation between the concentration of OLZ or DMO and the metabolic parameters was analyzed by the Spearman rank order correlation method (r s. PRINCIPAL FINDINGS: The established analytical method met proper standards for accuracy and reliability and the lower limitation of quantification for each injection of DMO or OLZ was 0.02 ng. The method was successfully used for the analysis of samples from nonsmoking patients (n = 48 treated with OLZ in the dosage range of 5-20 mg per day. There was no correlation between OLZ concentrations and tested metabolic parameters. DMO concentrations were negatively correlated with glucose (r s = -0.45 and DMO concentrations normalized by doses were also negatively correlated with insulin levels (r s = -0.39; however, there was a marginally positive correlation between DMO and homocysteine levels (r s = +0.38. CONCLUSIONS: The observed negative correlations between levels of DMO and glucose or insulin suggest a metabolic normalization role for DMO regardless of its positive correlation with a known cardiovascular risk factor, homocysteine. Additional studies of the mechanisms underlying DMO's metabolic effects are warranted.

  20. Achieving closure at Fernald

    Energy Technology Data Exchange (ETDEWEB)

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  1. 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

  2. Coal pyrolysis to acetylene using dc hydrogen plasma torch: effects of system variables on acetylene concentration

    Energy Technology Data Exchange (ETDEWEB)

    Chen Longwei; Meng Yuedong; Shen Jie; Shu Xingsheng; Fang Shidong [Laboratory of Applied Low-temperature Plasma Physics, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, 230031 (China); Xiong Xinyang, E-mail: lwchen@ipp.ac.c [Xinjiang Tianye Group, Xinjiang, 832000 (China)

    2009-03-07

    In order to unveil the inner mechanisms that determine acetylene concentration, experimental studies on the effect of several parameters such as plasma torch power, hydrogen flux and coal flux were carried out from coal pyrolysis in a dc plasma torch. Xinjiang long flame coals including volatile constituents at a level of about 42% were used in the experiment. Under the following experimental conditions, namely plasma torch power, hydrogen flow rate and pulverized coal feed speed of 2.12 MW, 32 kg h{sup -1} and 900 kg h{sup -1}, respectively, acetylene volume concentration of about 9.4% was achieved. The experimental results indicate that parameters such as plasma torch power and coal flux play important roles in the formation of acetylene. Acetylene concentration increases inconspicuously with hydrogen flux. A chemical thermodynamic equilibrium model using the free energy method is introduced in this paper to numerically simulate each experimental condition. The numerical results are qualitatively consistent with the experimental results. Two parameters, i.e. the gas temperature and the ratio of hydrogen/carbon, are considered to be the dominant and independent factors that determine acetylene concentration.

  3. Coal pyrolysis to acetylene using dc hydrogen plasma torch: effects of system variables on acetylene concentration

    Science.gov (United States)

    Chen, Longwei; Meng, Yuedong; Shen, Jie; Shu, Xingsheng; Fang, Shidong; Xiong, Xinyang

    2009-03-01

    In order to unveil the inner mechanisms that determine acetylene concentration, experimental studies on the effect of several parameters such as plasma torch power, hydrogen flux and coal flux were carried out from coal pyrolysis in a dc plasma torch. Xinjiang long flame coals including volatile constituents at a level of about 42% were used in the experiment. Under the following experimental conditions, namely plasma torch power, hydrogen flow rate and pulverized coal feed speed of 2.12 MW, 32 kg h-1 and 900 kg h-1, respectively, acetylene volume concentration of about 9.4% was achieved. The experimental results indicate that parameters such as plasma torch power and coal flux play important roles in the formation of acetylene. Acetylene concentration increases inconspicuously with hydrogen flux. A chemical thermodynamic equilibrium model using the free energy method is introduced in this paper to numerically simulate each experimental condition. The numerical results are qualitatively consistent with the experimental results. Two parameters, i.e. the gas temperature and the ratio of hydrogen/carbon, are considered to be the dominant and independent factors that determine acetylene concentration.

  4. Microwave plasma: its characteristics and applications in thin film technology

    Energy Technology Data Exchange (ETDEWEB)

    Musil, J.

    Microwave plasmas differ significantly from other plasmas, exhibit many interesting properties and so offer new possibilities for the plasma processing of thin films. Plasma properties strongly depend on the conditions and methods used to excite the gas. Due to the existence of a direct connection between the properties of plasma-prepared thin films and plasma micro-parameters a perfect knowledge of the plasma generation is a basic requirement for mastering a plasma deposition process. Therefore, different methods of generating microwave isotropic and anisotropic plasmas are discussed. Special attention is devoted to the mechanisms of plasma excitation and to the generation of a dense and homogeneous plasma in thin film technology are also presented.

  5. Neutrino beam plasma instability

    Indian Academy of Sciences (India)

    Vishnu M Bannur

    2001-10-01

    We derive relativistic fluid set of equations for neutrinos and electrons from relativistic Vlasov equations with Fermi weak interaction force. Using these fluid equations, we obtain a dispersion relation describing neutrino beam plasma instability, which is little different from normal dispersion relation of streaming instability. It contains new, nonelectromagnetic, neutrino-plasma (or electroweak) stable and unstable modes also. The growth of the instability is weak for the highly relativistic neutrino flux, but becomes stronger for weakly relativistic neutrino flux in the case of parameters appropriate to the early universe and supernova explosions. However, this mode is dominant only for the beam velocity greater than 0.25 and in the other limit electroweak unstable mode takes over.

  6. Microinstabilities in stellarator plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rafiq, T.; Nasim, M.H.; Persson, M. [Department of Electromagnetics and Euratom/VR Association, Chalmers University of Technology, Goeteborg (Sweden)

    2003-07-01

    Linear stability and localization of ion temperature gradient modes in fully 3-dimensional stellarator plasmas is calculated in the electrostatic limit. A ballooning mode formalism with WKB assumption is applied to reduce the equations into ordinary differential equation along the field lines which are solved numerically for different plasma parameters. The results are correlated with the geometrical effects such as magnetic curvature, local magnetic shear and its integrated value along the field line and the effects of trapped electrons are also investigated. The eigenfunctions of the most unstable modes are found to be localized but the nodes in the amplitude of the eigenfunctions may be large depending upon the location on the magnetic surface. The results are compared and contrasted with calculations in tokamak geometry and the implications on future stellarator design is also discussed. (orig.)

  7. Wavelet Analysis on Solar Wind Parameters and Geomagnetic Indices

    CERN Document Server

    Katsavrias, Ch; Moussas, X

    2012-01-01

    The sun as an oscillator produces frequencies which propagate in the heliosphere, via solar wind, to the terrestrial magnetosphere. We searched for those frequencies in the parameters of the near Earth solar plasma and the geomagnetic indices for the past four solar cycles. The solar wind parameters used in this work are the interplanetary magnetic field, plasma beta, Alfven Mach number, solar wind speed, plasma temperature, plasma pressure, plasma density and the geomagnetic indices DST, AE, Ap and Kp. We found out that each parameter of the solar wind exhibit certain periodicities which di?erentiate in each cycle. Our results indicate intermittent periodicities in our data, some of them shared between the solar wind parameters and geomagnetic indices.

  8. Aerospace applications of pulsed plasmas

    Science.gov (United States)

    Starikovskiy, Andrey

    2012-10-01

    The use of a thermal equilibrium plasma for combustion control dates back more than a hundred years to the advent of internal combustion (IC) engines and spark ignition systems. The same principles are still applied today to achieve high efficiency in various applications. Recently, the potential use of nonequilibrium plasma for ignition and combustion control has garnered increasing interest due to the possibility of plasma-assisted approaches for ignition and flame stabilization. During the past decade, significant progress has been made toward understanding the mechanisms of plasma chemistry interactions, energy redistribution and the nonequilibrium initiation of combustion. In addition, a wide variety of fuels have been examined using various types of discharge plasmas. Plasma application has been shown to provide additional combustion control, which is necessary for ultra-lean flames, high-speed flows, cold low-pressure conditions of high-altitude gas turbine engine (GTE) relight, detonation initiation in pulsed detonation engines (PDE) and distributed ignition control in homogeneous charge-compression ignition (HCCI) engines, among others. The present paper describes the current understanding of the nonequilibrium excitation of combustible mixtures by electrical discharges and plasma-assisted ignition and combustion. Nonequilibrium plasma demonstrates an ability to control ultra-lean, ultra-fast, low-temperature flames and appears to be an extremely promising technology for a wide range of applications, including aviation GTEs, piston engines, ramjets, scramjets and detonation initiation for pulsed detonation engines. To use nonequilibrium plasma for ignition and combustion in real energetic systems, one must understand the mechanisms of plasma-assisted ignition and combustion and be able to numerically simulate the discharge and combustion processes under various conditions.

  9. Achievement Goals and Achievement Emotions: A Meta-Analysis

    Science.gov (United States)

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  10. Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production

    Science.gov (United States)

    Amole, C.; Ashkezari, M. D.; Baquero-Ruiz, M.; Bertsche, W.; Butler, E.; Capra, A.; Cesar, C. L.; Charlton, M.; Deller, A.; Eriksson, S.; Fajans, J.; Friesen, T.; Fujiwara, M. C.; Gill, D. R.; Gutierrez, A.; Hangst, J. S.; Hardy, W. N.; Hayden, M. E.; Isaac, C. A.; Jonsell, S.; Kurchaninov, L.; Little, A.; Madsen, N.; McKenna, J. T. K.; Menary, S.; Napoli, S. C.; Olchanski, K.; Olin, A.; Pusa, P.; Rasmussen, C. Ø.; Robicheaux, F.; Sarid, E.; Shields, C. R.; Silveira, D. M.; So, C.; Stracka, S.; Thompson, R. I.; van der Werf, D. P.; Wurtele, J. S.; Zhmoginov, A.; Friedland, L.

    2013-04-01

    One of the goals of synthesizing and trapping antihydrogen is to study the validity of charge-parity-time symmetry through precision spectroscopy on the anti-atoms, but the trapping yield achieved in recent experiments must be significantly improved before this can be realized. Antihydrogen atoms are commonly produced by mixing antiprotons and positrons stored in a nested Penning-Malmberg trap, which was achieved in ALPHA by an autoresonant excitation of the antiprotons, injecting them into the positron plasma. In this work, a hybrid numerical model is developed to simulate antiproton and positron dynamics during the mixing process. The simulation is benchmarked against other numerical and analytic models, as well as experimental measurements. The autoresonant injection scheme and an alternative scheme are compared numerically over a range of plasma parameters which can be reached in current and upcoming antihydrogen experiments, and the latter scheme is seen to offer significant improvement in trapping yield as the number of available antiprotons increases.

  11. Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Amole, C.; Capra, A.; Menary, S. [Department of Physics and Astronomy, York University, Toronto, M3J 1P3 Ontario (Canada); Ashkezari, M. D.; Hayden, M. E. [Department of Physics, Simon Fraser University, Burnaby, V5A 1S6 British Columbia (Canada); Baquero-Ruiz, M.; Little, A.; So, C.; Zhmoginov, A. [Department of Physics, University of California, Berkeley, California 94720 (United States); Bertsche, W. [Department of Physics, College of Science, Swansea University, SA2 8PP Swansea (United Kingdom); School of Physics and Astronomy, University of Manchester, M13 9PL Manchester (United Kingdom); Daresbury Laboratory, Cockcroft Institute, WA4 4AD Warrington (United Kingdom); Butler, E. [Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Cesar, C. L.; Silveira, D. M. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941 (Brazil); Charlton, M.; Deller, A.; Eriksson, S.; Isaac, C. A.; Madsen, N.; Napoli, S. C.; Shields, C. R. [Department of Physics, College of Science, Swansea University, SA2 8PP Swansea (United Kingdom); Collaboration: ALPHA Collaboration; and others

    2013-04-15

    One of the goals of synthesizing and trapping antihydrogen is to study the validity of charge-parity-time symmetry through precision spectroscopy on the anti-atoms, but the trapping yield achieved in recent experiments must be significantly improved before this can be realized. Antihydrogen atoms are commonly produced by mixing antiprotons and positrons stored in a nested Penning-Malmberg trap, which was achieved in ALPHA by an autoresonant excitation of the antiprotons, injecting them into the positron plasma. In this work, a hybrid numerical model is developed to simulate antiproton and positron dynamics during the mixing process. The simulation is benchmarked against other numerical and analytic models, as well as experimental measurements. The autoresonant injection scheme and an alternative scheme are compared numerically over a range of plasma parameters which can be reached in current and upcoming antihydrogen experiments, and the latter scheme is seen to offer significant improvement in trapping yield as the number of available antiprotons increases.

  12. Experimental Study and Optimisation of Mrr In CNC Plasma ARC Cutting

    Directory of Open Access Journals (Sweden)

    Gurwinder Singh

    2015-06-01

    Full Text Available The research and development in the precise and accurate machining technology of hard metals (Ferrous, nonferrous and glass etc is gaining much importance in the industry since last many years. Due to the tremendous competition and cost factor, the non-conventional machining technology is becoming the first choice of the engineers and technicians. In this era of advanced technological processes the CNC plasma arc machining is gaining tremendous ground in the industry. It is much more capable of producing best finished, high accurate machining of very complicated non-symmetrical profile in no time. The main objective and targets of this practical experiment is based to achieve the best possible setting and parameters of operation on a CNC plasma arc machine to achieving speedy work i.e. Maximum material removal rate.

  13. MODFLOW-style parameters in underdetermined parameter estimation

    Science.gov (United States)

    D'Oria, Marco D.; Fienen, Michael N.

    2012-01-01

    In this article, we discuss the use of MODFLOW-Style parameters in the numerical codes MODFLOW_2005 and MODFLOW_2005-Adjoint for the definition of variables in the Layer Property Flow package. Parameters are a useful tool to represent aquifer properties in both codes and are the only option available in the adjoint version. Moreover, for overdetermined parameter estimation problems, the parameter approach for model input can make data input easier. We found that if each estimable parameter is defined by one parameter, the codes require a large computational effort and substantial gains in efficiency are achieved by removing logical comparison of character strings that represent the names and types of the parameters. An alternative formulation already available in the current implementation of the code can also alleviate the efficiency degradation due to character comparisons in the special case of distributed parameters defined through multiplication matrices. The authors also hope that lessons learned in analyzing the performance of the MODFLOW family codes will be enlightening to developers of other Fortran implementations of numerical codes.

  14. Revisiting the plasma sheath - dust in plasma sheath

    CERN Document Server

    Das, G C; Bora, M P

    2015-01-01

    In this work, we have considered the formation of warm plasma sheath in the vicinity of a wall in a plasma with considerable presence of dust particles. As an example, we have used the parameters relevant in case of lunar plasma sheath, though the results obtained in this work could be applied to any other physical situation such as laboratory plasma. In the ion-acoustic time scale, we neglect the dust dynamics. The dust particles affect the sheath dynamics by affecting the Poisson equation which determines the plasma potential in the sheath region. We have assumed the current to a dust particle to be balanced throughout the analysis. This makes the grain potential dependent on plasma potential, which is then incorporated into the Poisson equation. The resultant numerical model becomes an initial value problem, which is described by a 1-D integro-differential equation, which is then solved self-consistently by incorporating the change in plasma potential caused by inclusion of the dust potential in the Poisso...

  15. Plasma metamaterials as cloaking and nonlinear media

    Science.gov (United States)

    Sakai, O.; Yamaguchi, S.; Bambina, A.; Iwai, A.; Nakamura, Y.; Tamayama, Y.; Miyagi, S.

    2017-01-01

    Plasma metamaterials, composites of low-temperature plasmas and periodic functional microstructures, work as cloaking and nonlinear media. Due to functions of the microstructures like negative permeability, electromagnetic waves in and around plasma metamaterials propagate in a quite different manner from the case with the conventional space in which relative permeability is positive and unity. Using plasmas and plasma metamaterials, we achieve various controls of microwave propagating paths such as unidirectionality and cloaking in the two- or 3D spaces. For instance, a concentric plasma layer makes wave propagation unidirectional, and waves propagate in different routes when they start inside or outside the concentric layer. Furthermore, due to spatial permittivity gradient and anisotropic refractive index, electromagnetic waves detour in plasma metamaterial layers. Another significant point that plasma metamaterials can realize is nonlinearity. When we study high-power electromagnetic waves propagating in them, we observe several properties describable in terms of nonlinear dynamics and nonlinear photonics. Microwaves beyond threshold energy trigger bifurcations in plasma permittivity, and the second harmonic wave detected simultaneously is generated with strong emission levels. Such electromagnetic wave propagation is achieved with advantages over other materials, since plasmas and metallic microstructures work in harmony and in synergy.

  16. Stark broadening data for stellar plasma research.

    Science.gov (United States)

    Dimitrijević, M. S.

    Results of an effort to provide to astrophysicists and physicists an as much as possible complete set of Stark broadening parameters needed for stellar opacity calculations, stellar atmosphere modelling, abundance determinations and diagnostics of different plasmas in astrophysics, physics and plasma technology, are presented. Stark broadening has been considered within the semiclassical perturbation, and the modified semiempirical approaches.

  17. Transport studies in fusion plasmas: Perturbative experiments

    NARCIS (Netherlands)

    Cardozo, N. L.

    1998-01-01

    By inducing in a small temperature perturbation in a plasma in a steady state one can determine the conductive and convective components of the heat flux, and the associated thermal diffusivity and convection velocity. The same can be done for the density, and in principle also other plasma paramete

  18. HARDENING OF CRANE RAILS BY PLASMA DISCRETE-TIME SURFACE TREATMENT

    Directory of Open Access Journals (Sweden)

    S. S. Samotugin

    2017-01-01

    Full Text Available Crane wheels and rails are subjected to intensive wear in the process of operation. Therefore, improvement of these components’ performance can be considered a task of high importance. A promising direction in this regard is surface treatment by highly concentrated energy flows such as laser beams or plasma jets. This thesis suggests that the use of gradient plasma surface treatment can improve the performance of crane rails. A research was conducted, according to which hardened zones were deposited on crane rails under different treatment modes. Microhardness was measured both at the surface and in depth using custom-made microsections. The article includes the results of study of plasma surface hardening effects on wear resistance of crane rails. Change of plasma surface treatment parameters (current, plasma torch movement speed, argon gas flow rate allows for desired steel hardness and structure, while the choice of optimal location for hardened zones makes it possible to significantly improve wear resistance and crack resistance. As a result of plasma surface hardening, the fine-grained martensite structure is obtained with mainly lamellar morphology and higher hardness rate compared toinduction hardening or overlaying. Wear test of carbon steels revealed that plasma surfacing reduces abrasive wear rate compared to the irinitial state by 2 to 3 times. Enough sharp boundary between hardened and non-hardened portions has a positive effect on the performance of parts under dynamic loads, contributing to the inhibition of cracks during the transition from solid to a soft metal. For carbon and low alloy rail steels, the properties achieved by plasma surface hardening can effectively replace induction hardening or overlaying.The mode range for plasma surface treatment that allow sobtaining a surface layer with certain operating properties has been determined.

  19. Electromagnetic waves in a strong Schwarzschild plasma