Vacuum heating evaluation for plasmas of exponentially decreasing density profile

International Nuclear Information System (INIS)

Pestehe, S.J.; Mohammadnejad, M.

2008-01-01

Ultra-short pulse lasers have opened a regime of laser-plasma interaction where plasmas have scale lengths shorter than the laser wavelength and allow the possibility of generating near-solid density plasmas. The interaction of high-intensity laser beams with sharply bounded high-density and small scale length plasmas is considered. Absorption of the laser energy associated with the mechanism of dragging electrons out of the plasma into the vacuum and sending them back into the plasma with the electric field component along the density gradient, so called vacuum heating, is studied. An exponentially decreasing electron density profile is assumed. The vector potential of the electromagnetic field propagating through the plasma is calculated and the behaviour of the electric and magnetic components of the electromagnetic field is studied. The fraction of laser power absorbed in this process is calculated and plotted versus the laser beam incidence angle, illumination energy, and the plasma scale length

More vertical etch profile using a Faraday cage in plasma etching

Science.gov (United States)

Cho, Byeong-Ok; Hwang, Sung-Wook; Ryu, Jung-Hyun; Moon, Sang Heup

1999-05-01

Scanning electron microscope images of sidewalls obtained by plasma etching of an SiO2 film with and without a Faraday cage have been compared. When the substrate film is etched in the Faraday cage, faceting is effectively suppressed and the etch profile becomes more vertical regardless of the process conditions. This is because the electric potential in the cage is nearly uniform and therefore distortion of the electric field at the convex corner of a microfeature is prevented. The most vertical etch profile is obtained when the cage is used in fluorocarbon plasmas, where faceting is further suppressed due to the decrease in the chemical sputtering yield and the increase in the radical/ion flux on the substrate.

Heavy ion beam study of potential formation in bumpy torus plasma

International Nuclear Information System (INIS)

Takasugi, Keiichi.

1985-01-01

A heavy ion beam probe is constructed for the study of plasma confinement in Nagoya Bumpy Torus (NBT-1/1M). The measurement of the local plasma potential as well as the electron density profile is possible with good spatial (1 -- 2 cm) and temporal (-- 1 msec) resolutions. The feedback controlled detection technique and the time resolved fast detection technique are coupled to use, which enables us to measure local potential reliably even in the pulsed experiments. The process of the devlopment of concentric equipotential surface is observed. The cold and collisional plasma in bumpy torus is not in the equilibrium (C-mode), and the vertically polarized potential profile is produced by the toroidal drift. With the growth of warm collisionless electron component, the polarization is poloidally short-circuited, and the concentric equipotential surface is developed. The concentric negative potential well and its positive rim are observed in the standard operation. The position of the potential boundary (rim) moves with the second harmonic ECRH zone at the midplane of each mirror section, where the hot electron ring exists. The rim potential is formed by the direct loss of warm electrons. It is confirmed that the core electron heating is essential for the negative potential formation. The potential depth is much larger than the ion temperature Tsub(i), and cannot be explained by the existing neoclassical theory. A stable positive potential is observed near T-M transition. The positive potential is also observed in the ion heated plasma. Relating to the growth of the high energy component, the potential formation due to direct loss process is discussed. (author)

Mode suppression of a two-dimensional potential relaxation instability in a weakly magnetized discharge plasma

Science.gov (United States)

Gyergyek, T.; Čerček, M.; Jelić, N.; Stanojević, M.

1993-05-01

A potential relaxation instability (PRI) is modulated by an external signal using an additional grid to modulate the radial plasma potential profile in a magnetized plasma column in a linear magnetized discharge plasma device. It is observed that the electrode current oscillations follow the van der Pol equation with an external forcing term, and the linear growth rate of the instability is measured.

Edge density profiles in high-performance JET plasmas

International Nuclear Information System (INIS)

Summers, D.D.R.; Viaccoz, B.; Vince, J.

1997-01-01

Detailed electron density profiles of the scrape-off layer in high-performance JET plasmas (plasma current, I p nbi ∝17 MW) have been measured by means of a lithium beam diagnostic system featuring high spatial resolution [Kadota (1978)[. Measurements were taken over a period of several seconds, allowing examination of the evolution of the edge profile at a location upstream from the divertor target. The data clearly show the effects of the H-mode transition - an increase in density near the plasma separatrix and a reduction in density scrape-off length. The profiles obtained under various plasma conditions are compared firstly with data from other diagnostics, located elsewhere in the vessel, and also with the predictions of an 'onion-skin' model (DIVIMP), which used, as initial parameters, data from an array of probes located in the divertor target. (orig.)

Plasma potential formation and measurement in TMX-U and MFTF-B

International Nuclear Information System (INIS)

Grubb, D.P.

1984-01-01

Tandem mirrors control the axial variation of the plasma potential to create electrostatic plugs that improve the axial confinement of central cell ions and, in a thermal barrier tandem mirror, control the electron axial heat flow. Measurements of the spatial and temporal variations of the plasma potential are, therefore, important to the understanding of confinement in a tandem mirror. In this paper we discuss potential formation in a thermal barrier tandem mirror and examine the diagnostics and data obtained on the TMX-U device, including measurements of the thermal barrier potential profile using a diagnostic neutral beam and charged particle energy-spectroscopy. We then describe the heavy ion beam probe and other new plasma potential diagnostics that are under development for TMX-U and MFTF-B and examine problem areas where additional diagnostic development is desirable

Full Tokamak discharge simulation and kinetic plasma profile control for ITER

International Nuclear Information System (INIS)

Hee Kim, S.

2009-10-01

technique that simplifies the active real-time control of several kinetic plasma profiles in ITER. The response of the plasma profiles to power changes of auxiliary H and CD systems is modelled. To allow real-time update of the plasma profile response model, the related physics is simplified with several assumptions. The electron temperature profile response is modelled by simplifying the electron heat transport equation. The q profile response is modelled by directly relating it to the changes of source current density profiles. The required actuator power changes are calculated using the singular value decomposition (SVD) technique, taking the saturation of the actuator powers into account. The potential of this control technique has been shown by applying it to simulations of the ITER hybrid mode operation. (author)

The effect of plasma density profile on the backscatter of microwaves from a plasma-covered plane conductor

International Nuclear Information System (INIS)

Destler, W.W.; Singh, A.; Rodgers, J.

1993-01-01

In order to gain further insight into the mechanism of anomalous absorption of microwaves in a pulsed plasma column, the latter was studied using single and double Langmuir probes. Graphs of plasma potential recorded by floating Langmuir probes as a function of time were obtained for a range of pressure of the background gas and at different distances from the plasma-covered plane-conducting plate. From this data, two main components of the plasma have been identified. The first appears earlier, exhibits greater fluctuations and is shorter in duration than the second component. The presence of these two plasma components is consistent with earlier observations obtained from transverse transmission measurements of microwaves through the plasma. Variations in the envelopes of these two components as experimental conditions are changed will be presented. Microwave backscatter measurements under varying conditions of plasma-density profile and ambient gas pressure will also be presented

Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade

DEFF Research Database (Denmark)

Horacek, J.; Adamek, J.; Müller, H.W.

2010-01-01

This paper focuses on interpretation of fast (1 µs) and local (2–4 mm) measurements of plasma density, potential and electron temperature in the edge plasma of tokamak ASDEX Upgrade. Steady-state radial profiles demonstrate the credibility of the ball-pen probe. We demonstrate that floating...... potential fluctuations measured by a Langmuir probe are dominated by plasma electron temperature rather than potential. Spatial and temporal scales are found consistent with expectations based on interchange-driven turbulence. Conditionally averaged signals found for both potential and density are also...

Self-organization of hot plasmas the canonical profile transport model

CERN Document Server

Dnestrovskij, Yu N

2015-01-01

In this monograph the author presents the Canonical Profile Transport Model or CPTM as a rather general mathematical framework to simulate plasma discharges.The description of hot plasmas in a magnetic fusion device is a very challenging task and many plasma properties still lack a physical explanation. One important property is plasma self-organization.It is very well known from experiments that the radial profile of the plasma pressure and temperature remains rather unaffected by changes of the deposited power or plasma density. The attractiveness of the CPTM is that it includes the effect o

Time evolution of the bootstrap current profile in LHD plasmas

International Nuclear Information System (INIS)

Nakamura, Yuji; Kawaoto, K.; Watanabe, K.Y.

2008-10-01

The direction of the bootstrap current is inverted in the outward shifted plasmas of the Large Helical Device (LHD). In order to verify the reliability of the theoretical models of the bootstrap current in helical plasmas, the rotational transform profiles are observed by the Motional Stark Effect measurement in the bootstrap current carrying plasmas of the LHD, and they are compared with the numerical simulations of the toroidal current profile including the bootstrap current. Since the toroidal current profile is not in the steady state in these plasmas, taking care of the inversely induced component of the toroidal current and finite duration of the resistive diffusion of the toroidal current are important in the numerical simulations. Reasonable agreement can be obtained between the rotational transform profiles measured in the experiments and those calculated in the numerical simulations. (author)

Plasma profile recovery by function parameterisation

International Nuclear Information System (INIS)

McCarthy, P.J.; Sexton, M.C.

1986-11-01

The use of Function Parameterisation for the recovery of plasma profiles as a function of flux surface area from spatial point data directly combined with external magnetic measurements is demonstrated in the case of ASDEX electron temperature and density profiles. The extrapolated temperature on the magnetic axis is shown to be more reliable than that obtained from a conventional fitting procedure. (orig.)

Potential formation in a collisionless plasma produced in an open magnetic field in presence of volume negative ion source

International Nuclear Information System (INIS)

Phukan, Ananya; Goswami, K. S.; Bhuyan, P. J.

2014-01-01

The electric potential near a wall for a multi-species plasma with volume produced negative ions in presence of axially varying magnetic field is studied following an analytical-numerical approach. A constant negative ion source is assumed throughout the plasma volume, along with finite temperature positive ions and Boltzmann electrons. The particles are assumed to be guided by an open magnetic field that has its maximum at the centre, and field strength decreasing towards the walls. The one dimensional (1D) Poisson equation is derived using an analytical approach, and then solved numerically to study the potential profiles. Effect of (a) negative ion production rate, (b) magnetic field profile, and (c) negative ion temperature on the potential profile has been investigated. A potential peak appears near the wall when the negative ion temperature and density are sufficiently high. Also, the presence of negative ions further decreases the potential in the plasma region for a finite Debye Length (λ D )

Longitudinal plasma metabolic profiles, infant feeding, and islet autoimmunity in the MIDIA study

DEFF Research Database (Denmark)

Jørgenrud, Benedicte; Stene, Lars C; Tapia, German

2017-01-01

Aims: The aim of this study was to investigate the longitudinal plasma metabolic profiles in healthy infants and the potential association with breastfeeding duration and islet autoantibodies predictive of type 1 diabetes. Method: Up to four longitudinal plasma samples from age 3 months from case......, and lower levels of methionine and 3,4-dihydroxybutyric acid at 3 months of age. Conclusions: Plasma levels of several small, polar metabolites changed with age during early childhood, independent of later islet autoimmunity status and sex. Breastfeeding was associated with higher levels of branched......-chain amino acids, and lower levels of methionine and 3,4-dihydroxybutyric acid....

Analysis of plasma equilibrium based on orbit-driven current density profile in steady-state plasma on QUEST

Energy Technology Data Exchange (ETDEWEB)

Nakamura, K., E-mail: nakamura@triam.kyushu-u.ac.jp [RIAM, Kyushu University, Kasuga 816-8580 (Japan); Alam, M.M. [IGSES, Kyushu University, Kasuga 816-8580 (Japan); Jiang, Y.Z. [Tsinghua University, Beijing 100084 (China); Mitarai, O. [Tokai University, Kumamoto 862-8652 (Japan); Kurihara, K.; Kawamata, Y.; Sueoka, M.; Takechi, M. [Japan Atomic Energy Agency, Naka 311-0193 (Japan); Hasegawa, M.; Tokunaga, K.; Araki, K.; Zushi, H.; Hanada, K.; Fujisawa, A.; Idei, H.; Nagashima, Y.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Nagata, T. [RIAM, Kyushu University, Kasuga 816-8580 (Japan); and others

2016-11-01

Highlights: • High energy particle guiding center orbit is calculated as a contour plot of conserved variable. • Current density profile is analyzed based on the orbit-driven current. • Plasma equilibrium is reconstructed by considering the hollow current profile. - Abstract: In the present RF-driven (ECCD) steady-state plasma on QUEST (B{sub t} = 0.25 T, R = 0.68 m, a = 0.40 m), plasma current seems to flow in the open magnetic surface outside of the closed magnetic surface in the low-field region according to plasma current fitting (PCF) method. We consider that the current in the open magnetic surface is due to orbit-driven current by high-energy particles in RF-driven plasma. So based on the analysis of current density profile based on the orbit-driven current, plasma equilibrium is to be calculated. We calculated high energy particles guiding center orbits as a contour plot of conserved variable in Hamiltonian formulation and considered particles initial position with different levels of energy and pitch angles that satisfy resonance condition. Then the profile of orbit-driven current is estimated by multiplying the particle density on the resonance surface and the velocity on the orbits. This analysis shows negative current near the magnetic axis and hollow current profile is expected even if pressure driven current is considered. Considering the hollow current profile shifted toward the low-field region, the equilibrium is fitted by J-EFIT coded by MATLAB.

Heavy ion beam probe investigations of plasma potential in ECRH and NBI in the TJ-II stellarator

International Nuclear Information System (INIS)

Melnikov, A.V.; Eliseev, L.; Perfilov, S.V.; Chmyga, A.A.; Dreval, N.; Khrebtov, S.M.; Komarov, A.D.; Kozachok, A.S.; Krupnik, L.; Alonso, A.; Pablos, J.L. de; Cappa, A.; Fernandez, A.; Fuentes, C.; Hidalgo, C.; Liniers, M.; Pedrosa, M.A.

2005-01-01

Direct measurements of electric potential and its fluctuations are of a primary importance in magnetic confinement systems. The Heavy Ion Beam Probe (HIBP) diagnostic is used in TJ-2 stellarator to study directly plasma electric potential profiles with spatial (up to 1cm) and temporal (up to 10 ∝s) resolution. The singly charged heavy ions Cs + with energies up to 125 keV are used to probe the plasma column from the edge to the core. Both ECRH and NBI heated plasmas (P ECRH = 200 - 400kW, P NBI = 400kW, E NBI = 28 kV) were studied. The significant improvement in the HIBP beam control system and the acquisition electronics leads us to increase the possibilities of the diagnostic. The most crucial one is the extension of the signal dynamic range, which allows us to have the reliable profiles from the plasma center to the plasma edge both in the high and low field side regions. Low density ECRH (n = 0.5-1.1.10 13 cm -3 ) plasmas in TJ-2 are characterised by core positive plasma potential of order of 500 - 1000 V and positive electric fields up to 50 V/cm. Edge radial electric fields remain positive at low densities and became negative at the threshold density that depends of plasma configuration. NBI plasmas are characterized by negative electric potential in the full plasma column and negative radial electric fields (in the range of 10 - 40 V/cm). The density rise during the NBI phase is accompanied by the decay of core plasma potential. When density is getting the level of n ∼ 2.0.10 13 cm -3 , the potential stops its evolution and remains constant. The evolution of plasma potential near density limit is under investigation. These observations, reported in different magnetic configurations, show the clear link between plasma potential and plasma density. (author)

Measurement of plasma potential and electron temperature by ball-pen probes in RFX-MOD

International Nuclear Information System (INIS)

Brotankova, J.; Adamek, J.; Stockel, J.; Martines, E.; Spolaore, M.; Cavazzana, R.; Serianni, G.; Vianello, N.; Zuin, M.

2009-01-01

The ball-pen probe (BPP) is an innovative electric probe for direct measurements of the plasma potential. This probe was developed in IPP Prague and it is based on the Katsumata probe concept. Combined measurements of the plasma potential by a BPP and floating potential by a Langmuir probe provide also the value of the electron temperature. First test of the BPP on the RFX-mod reversed field pinch in Padova has been performed in November 2006. The BPP head, made of boron nitride, is equipped with four graphite collectors, which are positioned at four different radial positions h inside four shafts hollow into the probe head. The radial profile of the plasma potential and also the electron temperature were measured

TPSS plasma engineering studies: profile effects and plasma power balance

International Nuclear Information System (INIS)

Borowski, S.K.; Strickler, D.J.

1985-01-01

A computationally fast profile-averaged, steady-state plasma model has been developed to allow studies of radial effects in ignited and driven tokamak systems. This code was used to search for the smallest size tokamak consistent with power balance calculations

Measurement of plasma edge profile on Wendelstein 7-X

Energy Technology Data Exchange (ETDEWEB)

Drews, Philipp; Liang, Yunfeng; Neubauer, Olaf; Denner, Peter; Rack, Michael; Liu, Shaocheng; Wang, Nunchao; Nicolai, Dirk; Hollfeld, Klaus; Satheeswaran, Guruparan [Forschungszentrum Juelich, IEK4, Juelich (Germany); Grulke, Olaf [Max-Planck-Institut fuer Plasmaphysik, Greifswald (Germany); Collaboration: W7-X Team

2016-07-01

Wendelstein 7-X (W7-X), currently under commissioning at the IPP Greifswald, will be the world's largest stellarator with modular superconducting coils, which will enable steady-state-like plasma operation of up to thirty minutes in order to explore the reactor relevance of this concept. The first operation phase of W7-X will employ a limiter configuration. It will be used primarily for setting up the diagnostics and testing the magnetic configuration. In conjunction with the multipurpose manipulator, a fast reciprocating probe is installed. The combined probe head will be used to measure the radial distribution of the magnetic field using magnetic pick-up coils; the plasma temperature and density profiles and the radial electric field using Langmuir pins; and the plasma flows using a Mach setup. As a quasi-isodynamic stellarator, it has been predicted that not only neoclassical but also turbulent transport will be comparable to or possibly even lower than that of tokamaks. Edge plasma profile measurements, especially those of the electron temperature and density, will play a key role in validating this performance in comparison to the tokamak and hence the viability of a stellarator fusion reactor. The edge plasma profile measurements using the combined probe head are presented.

Real-time control of current and pressure profiles in tokamak plasmas

International Nuclear Information System (INIS)

Laborde, L.

2005-12-01

Recent progress in the field of 'advanced tokamak scenarios' prefigure the operation regime of a future thermonuclear fusion power plant. Compared to the reference regime, these scenarios offer a longer plasma confinement time thanks to increased magnetohydrodynamic stability and to a better particle and energy confinement through a reduction of plasma turbulence. This should give access to comparable fusion performances at reduced plasma current and could lead to a steady state fusion reactor since the plasma current could be entirely generated non-inductively. Access to this kind of regime is provided by the existence of an internal transport barrier, linked to the current profile evolution in the plasma, which leads to steep temperature and pressure profiles. The comparison between heat transport simulations and experiments allowed the nature of the barriers to be better understood as a region of strongly reduced turbulence. Thus, the control of this barrier in a stationary manner would be a remarkable progress, in particular in view of the experimental reactor ITER. The Tore Supra and JET tokamaks, based in France and in the United Kingdom, constitute ideal instruments for such experiments: the first one allows stationary plasmas to be maintained during several minutes whereas the second one provides unique fusion performances. In Tore Supra, real-time control experiments have been accomplished where the current profile width and the pressure profile gradient were controlled in a stationary manner using heating and current drive systems as actuators. In the JET tokamak, the determination of an empirical static model of the plasma allowed the current and pressure profiles to be simultaneously controlled and so an internal transport barrier to be sustained. Finally, the identification of a dynamic model of the plasma led to the definition of a new controller capable, in principle, of a more efficient control. (author)

Control of plasma profile in microwave discharges via inverse-problem approach

Directory of Open Access Journals (Sweden)

Yasuyoshi Yasaka

2013-12-01

Full Text Available In the manufacturing process of semiconductors, plasma processing is an essential technology, and the plasma used in the process is required to be of high density, low temperature, large diameter, and high uniformity. This research focuses on the microwave-excited plasma that meets these needs, and the research target is a spatial profile control. Two novel techniques are introduced to control the uniformity; one is a segmented slot antenna that can change radial distribution of the radiated field during operation, and the other is a hyper simulator that can predict microwave power distribution necessary for a desired radial density profile. The control system including these techniques provides a method of controlling radial profiles of the microwave plasma via inverse-problem approach, and is investigated numerically and experimentally.

The influence of Stark shift and plasma inhomogeneity on half width of self-absorbed line profiles in the plasma emission spectrum

International Nuclear Information System (INIS)

Catsalap, K.Yu.; Ershov-Pavlov, E.A.

2005-01-01

Emission spectral line profiles are commonly used for the evaluation of local plasma parameters. The plasma parameters and local line profiles are related in a rather simple way: e.g. at quadratic Stark broadening, the local line half widths and shifts are proportional to the electron density. For homogeneous optically thin plasmas, there is no difference in the line profiles of plasma emission and emissivity spectra. However for inhomogeneous source, the profiles are different due to spatial dependence of electron density and plasma temperature: profiles in the plasma emission are a superposition of different local ones. A transition from the recorded to local profiles is usually performed by tomography techniques. As the result, the measurement procedure is getting slower and additional errors occurs. For transparent plasmas, an approach was developed to evaluate local profiles from as recorded spectra using relations found by modeling. However, for semi-transparent plasmas the relation between the recorded and local profiles is more complicated one. With the optical thickness t increase, profile half width Δλ in the plasma emission spectrum changes much comparing to the profile half width Δλ 0 in the spectrum of optically thin plasma. The ratio t h =Δλ/Δλ 0 on τ for dispersion profile and homogeneous plasma can be written as t h =(-1-τ/ln((1+e -τ )/2)) 1/2 . When Δλ and τ are known, the function allows obtaining Δλ 0 , i. e. reducing the problem to the transparent plasma diagnostics. However, the plasma is nearly always inhomogeneous and the value t depends significantly on plasma inhomogeneity and on Stark parameters ratio d/w. Here, the dependence t(τ) for plasmas of different inhomogeneity rates has been obtained by the numerical simulation. The radiation transfer equation has been solved to calculate the spectral line profiles for LTE-plasma of known composition and distribution of temperature along the observation line. The temperature

Detection of lung cancer using plasma protein profiling by matrix-assisted laser desorption/ionization mass spectrometry.

Science.gov (United States)

Shevchenko, Valeriy E; Arnotskaya, Natalia E; Zaridze, David G

2010-01-01

There are no satisfactory plasma biomarkers which are available for the early detection and monitoring of lung cancer, one of the most frequent cancers worldwide. The aim of this study is to explore the application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) to plasma proteomic patterns to distinguish lung cancer patients from healthy individuals. The EDTA plasma samples have been pre-fractionated using magnetic bead kits functionalized with weak cation exchange coatings. We compiled MS protein profiles for 90 patients with squamous cell carcinomas (SCC) and compared them with profiles from 187 healthy controls. The MALDI-ToF spectra were analyzed statistically using ClinProTools bioinformatics software. Depending on the sample used, up to 441 peaks/spectrum could be detected in a mass range of 1000-20,000 Da; 33 of these proteins had statistically differential expression levels between SCC and control plasma (P 90%) in external validation test. These results suggest that plasma MALDI-ToF MS protein profiling can distinguish patients with SCC and also from healthy individuals with relatively high sensitivity and specificity and that MALDI- ToF MS is a potential tool for the screening of lung cancer.

Characterization of laser-produced plasma density profiles using grid image refractometry

International Nuclear Information System (INIS)

Craxton, R.S.; Turner, F.S.; Hoefen, R.; Darrow, C.; Gabl, E.F.; Busch, G.E.

1993-01-01

Grid image refractometry (GIR) is proposed as a technique for determining the two-dimensional density profiles of long scale-length laser-produced plasmas. Its distinctive feature is that an optical probe beam is broken up into ''rays'' by being passed through a grid before traversing the plasma. The refraction angles of the rays are measured by imaging the plasma at two or more object planes and are integrated to yield the phase front. For cylindrically symmetric plasmas the density profile is then determined using Abel inversion. The feasibility of GIR is illustrated by an experiment in which a thick CH target was irradiated with ∼100 J of 527 nm radiation and diagnosed with a 20 ps, 263 nm probe. The resulting density profile is substantially larger than any that have previously been reported using interferometry and compares quite closely with hydrodynamic simulations

Plasma and White Blood Cells Show Different miRNA Expression Profiles in Parkinson's Disease.

Science.gov (United States)

Schwienbacher, Christine; Foco, Luisa; Picard, Anne; Corradi, Eloina; Serafin, Alice; Panzer, Jörg; Zanigni, Stefano; Blankenburg, Hagen; Facheris, Maurizio F; Giannini, Giulia; Falla, Marika; Cortelli, Pietro; Pramstaller, Peter P; Hicks, Andrew A

2017-06-01

Parkinson's disease (PD) diagnosis is based on the assessment of motor symptoms, which manifest when more than 50% of dopaminergic neurons are degenerated. To date, no validated biomarkers are available for the diagnosis of PD. The aims of the present study are to evaluate whether plasma and white blood cells (WBCs) are interchangeable biomarker sources and to identify circulating plasma-based microRNA (miRNA) biomarkers for an early detection of PD. We profiled plasma miRNA levels in 99 L-dopa-treated PD patients from two independent data collections, in ten drug-naïve PD patients, and in unaffected controls matched by sex and age. We evaluated expression levels by reverse transcription and quantitative real-time PCR (RT-qPCR) and combined the results from treated PD patients using a fixed effect inverse-variance weighted meta-analysis. We revealed different expression profiles comparing plasma and WBCs and drug-naïve and L-dopa-treated PD patients. We observed an upregulation trend for miR-30a-5p in L-dopa-treated PD patients and investigated candidate target genes by integrated in silico analyses. We could not analyse miR-29b-3p, normally expressed in WBCs, due to the very low expression in plasma. We observed different expression profiles in WBCs and plasma, suggesting that they are both suitable but not interchangeable peripheral sources for biomarkers. We revealed miR-30a-5p as a potential biomarker for PD in plasma. In silico analyses suggest that miR-30a-5p might have a regulatory role in mitochondrial dynamics and autophagy. Further investigations are needed to confirm miR-30a-5p deregulation and targets and to investigate the influence of L-dopa treatment on miRNA expression levels.

Investigating plasma-rotation methods for the Space-Plasma Physics Campaign at UCLA's BAPSF.

Science.gov (United States)

Finnegan, S. M.; Koepke, M. E.; Reynolds, E. W.

2006-10-01

In D'Angelo et al., JGR 79, 4747 (1974), rigid-body ExB plasma flow was inferred from parabolic floating-potential profiles produced by a spiral ionizing surface. Here, taking a different approach, we report effects on barium-ion azimuthal-flow profiles using either a non-emissive or emissive spiral end-electrode in the WVU Q-machine. Neither electrode produced a radially-parabolic space-potential profile. The emissive spiral, however, generated controllable, radially-parabolic structure in the floating potential, consistent with a second population of electrons having a radially-parabolic parallel-energy profile. Laser-induced-fluorescence measurements of spatially resolved, azimuthal-velocity distribution functions show that, for a given flow profile, the diamagnetic drift of hot (>>0.2eV) ions overwhelms the ExB-drift contribution. Our experiments constitute a first attempt at producing controllable, rigid-body, ExB plasma flow for future experiments on the LArge-Plasma-Device (LAPD), as part of the Space-Plasma Physics Campaign (at UCLA's BAPSF).

Semi-analytical model of laser resonance absorption in plasmas with a parabolic density profile

International Nuclear Information System (INIS)

Pestehe, S J; Mohammadnejad, M

2010-01-01

Analytical expressions for mode conversion and resonance absorption of electromagnetic waves in inhomogeneous, unmagnetized plasmas are required for laboratory and simulation studies. Although most of the analyses of this problem have concentrated on the linear plasma density profile, there are a few research works that deal with different plasma density profiles including the parabolic profile. Almost none of them could give clear analytical formulae for the electric and magnetic components of the electromagnetic field propagating through inhomogeneous plasmas. In this paper, we have considered the resonant absorption of laser light near the critical density of plasmas with parabolic electron density profiles followed by a uniform over-dense region and have obtained expressions for the electric and magnetic vectors of laser light propagating through the plasma. An estimation of the fractional absorption of laser energy has also been carried out. It has been shown that, in contrast to the linear density profile, the energy absorption depends explicitly on the value of collision frequency as well as on a new parameter, N, called the over-dense density order.

The segmented non-uniform dielectric module design for uniformity control of plasma profile in a capacitively coupled plasma chamber

International Nuclear Information System (INIS)

Xia, Huanxiong; Xiang, Dong; Yang, Wang; Mou, Peng

2014-01-01

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

Study on possibility of plasma current profile determination using an analytical model of tokamak equilibrium

International Nuclear Information System (INIS)

Moriyama, Shin-ichi; Hiraki, Naoji

1996-01-01

The possibility of determining the current profile of tokamak plasma from the external magnetic measurements alone is investigated using an analytical model of tokamak equilibrium. The model, which is based on an approximate solution of the Grad-Shafranov equation, can set a plasma current profile expressed with four free parameters of the total plasma current, the poloidal beta, the plasma internal inductance and the axial safety factor. The analysis done with this model indicates that, for a D-shaped plasma, the boundary poloidal magnetic field prescribing the external magnetic field distribution is dependent on the axial safety factor in spite of keeping the boundary safety factor and the plasma internal inductance constant. This suggests that the plasma current profile is reversely determined from the external magnetic analysis. The possibility and the limitation of current profile determination are discussed through this analytical result. (author)

Characterization of Electron Temperature and Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

Science.gov (United States)

Oh, Jaechul; Weaver, J. L.; Phillips, L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Chan, L.-Y.; Serlin, V.

2011-10-01

Previous experiments with Nike KrF laser (λ = 248 nm , Δν ~ 1 THz) observed LPI signatures near quarter critical density (nc / 4) in CH plasmas, however, detailed measurement of the temperature (Te) and density (ne) profiles was missing. The current Nike LPI campaign will perform experimental determination of the plasma profiles. A side-on grid imaging refractometer (GIR) is the main diagnostic to resolve Te and ne in space taking 2D snapshots of probe laser (λ = 266 nm , Δt = 8 psec) beamlets (50 μm spacing) refracted by the plasma at laser peak time. Ray tracing of the beamlets through hydrodynamically simulated (FASTRAD3D) plasma profiles estimates the refractometer may access densities up to ~ 0 . 2nc . With the measured Te and ne profiles in the plasma corona, we will discuss analysis of light data radiated from the plasmas in spectral ranges relevant to two plasmon decay and convective Raman instabilities. Validity of the (Te ,ne) data will also be discussed for the thermal transport study. Work supported by DoE/NNSA and ONR and performed at NRL.

Profile formation and sustainment of autonomous tokamak plasma with current hole configuration

International Nuclear Information System (INIS)

Hayashi, N.; Takizuka, T.; Ozeki, T.

2005-01-01

We have investigated the profile formation and sustainment of tokamak plasmas with the current hole (CH) configuration by using 1.5D time-dependent transport simulations. A model of the current limit inside the CH on the basis of the Axisymmetric Tri-Magnetic-Islands equilibrium is introduced into the transport simulation. We found that a transport model with the sharp reduction of anomalous transport in the reversed-shear (RS) region can reproduce the time evolution of profiles observed in JT-60U experiments. The transport becomes neoclassical-level in the RS region, which results in the formation of profiles with internal transport barrier (ITB) and CH. The CH plasma has an autonomous property because of the strong interaction between a pressure profile and a current profile through the large bootstrap current fraction. The ITB width determined by the neoclassical-level transport agrees well with that measured in JT-60U. The energy confinement inside the ITB agrees with the scaling based on the JT-60U data. The scaling means the autonomous limitation of energy confinement in the CH plasma. The plasma with the large CH is sustained with the full current drive by the bootstrap current. The plasma with the small CH and the small bootstrap current fraction shrinks due to the penetration of inductive current. This shrink is prevented and the CH size can be controlled by the appropriate external current drive (CD). The CH plasma is found to respond autonomically to the external CD. (author)

Stationary neoclassical profiles of plasma parameters in stellarators

International Nuclear Information System (INIS)

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

1991-01-01

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

Exploration of one-dimensional plasma current density profile for K-DEMO steady-state operation

Energy Technology Data Exchange (ETDEWEB)

Kang, J.S. [Seoul National University, Seoul 151-742 (Korea, Republic of); Jung, L. [National Fusion Research Institute, Daejeon (Korea, Republic of); Byun, C.-S.; Na, D.H.; Na, Y.-S. [Seoul National University, Seoul 151-742 (Korea, Republic of); Hwang, Y.S., E-mail: yhwang@snu.ac.kr [Seoul National University, Seoul 151-742 (Korea, Republic of)

2016-11-01

Highlights: • One-dimensional current density and its optimization for the K-DEMO are explored. • Plasma current density profile is calculated with an integrated simulation code. • The impact of self and external heating profiles is considered self-consistently. • Current density is identified as a reference profile by minimizing heating power. - Abstract: Concept study for Korean demonstration fusion reactor (K-DEMO) is in progress, and basic design parameters are proposed by targeting high magnetic field operation with ITER-sized machine. High magnetic field operation is a favorable approach to enlarge relative plasma performance without increasing normalized beta or plasma current. Exploration of one-dimensional current density profile and its optimization process for the K-DEMO steady-state operation are reported in this paper. Numerical analysis is conducted with an integrated plasma simulation code package incorporating a transport code with equilibrium and current drive modules. Operation regimes are addressed with zero-dimensional system analysis. One-dimensional plasma current density profile is calculated based on equilibrium, bootstrap current analysis, and thermal transport analysis. The impact of self and external heating profiles on those parameters is considered self-consistently, where thermal power balance and 100% non-inductive current drive are the main constraints during the whole exploration procedure. Current and pressure profiles are identified as a reference steady-state profile by minimizing the external heating power with desired fusion power.

Plasma Profile Measurements for Laser Fusion Research with the Nike KrF Laser

Science.gov (United States)

Oh, Jaechul; Weaver, J. L.; Serlin, V.; Obenschain, S. P.

2015-11-01

The grid image refractometer of the Nike laser facility (Nike-GIR) has demonstrated the capability of simultaneously measuring electron density (ne) and temperature (Te) profiles of coronal plasma. For laser plasma instability (LPI) research, the first Nike-GIR experiment successfully measured the plasma profiles in density regions up to ne ~ 4 ×1021 cm-3 (22% of the critical density for 248 nm light of Nike) using an ultraviolet probe laser (λp = 263 nm). The probe laser has been recently replaced with a shorter wavelength laser (λp = 213 nm, a 5th harmonic of the Nd:YAG laser) to diagnose a higher density region. The Nike-GIR system is being further extended to measure plasma profiles in the on-going experiment using 135°-separated Nike beam arrays for the cross-beam energy transfer (CBET) studies. We present an overview of the extended Nike-GIR arrangements and a new numerical algorithm to extract self-consistant plasma profiles with the measured quantities. Work supported by DoE/NNSA.

CO2 laser diagnostics for measurements of the plasma density profile and plasma density fluctuations on LHD

International Nuclear Information System (INIS)

Vyacheslavov, L.N.; Tanaka, K.; Kawahata, K.

2001-04-01

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

Influence of plasma pedestal profiles on access to ELM-free regimes in ITER

Energy Technology Data Exchange (ETDEWEB)

Medvedev, S. Yu., E-mail: medvedev@a5.kiam.ru; Ivanov, A. A., E-mail: aai@a5.kiam.ru; Martynov, A. A., E-mail: martynov@a5.kiam.ru; Poshekhonov, Yu. Yu., E-mail: naida@a5.kiam.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Konovalov, S. V., E-mail: konoval-sv@nrcki.ru [National Research Nuclear University “MEPhI,” (Russian Federation); Polevoi, A. R., E-mail: alexei.polevoi@iter.org [ITER Organization (France)

2016-05-15

The influence of current density and pressure gradient profiles in the pedestal on the access to the regimes free from edge localized modes (ELMs) like quiescent H-mode in ITER is investigated. Using the simulator of MHD modes localized near plasma boundary based on the KINX code, calculations of the ELM stability were performed for the ITER plasma in scenarios 2 and 4 under variations of density and temperature profiles with the self-consistent bootstrap current in the pedestal. Low pressure gradient values at the separatrix, the same position of the density and temperature pedestals and high poloidal beta values facilitate reaching high current density in the pedestal and a potential transition into the regime with saturated large scale kink modes. New version of the localized MHD mode simulator allows one to compute the growth rates of ideal peeling-ballooning modes with different toroidal mode numbers and to determine the stability region taking into account diamagnetic stabilization. The edge stability diagrams computations and sensitivity studies of the stability limits to the value of diamagnetic frequency show that diamagnetic stabilization of the modes with high toroidal mode numbers can help to access the quiescent H-mode even with high plasma density but only with low pressure gradient values at the separatrix. The limiting pressure at the top of the pedestal increases for higher plasma density. With flat density profile the access to the quiescent H-mode is closed even with diamagnetic stabilization taken into account, while toroidal mode numbers of the most unstable peeling-ballooning mode decrease from n = 10−40 to n = 3−20.

Effect of plasma density profile of tokamak on Kelvin-Helmholtz instability

International Nuclear Information System (INIS)

Tang Fulin

1984-01-01

The purpose of this paper is to study the effect of radial distribution of plasma density profile of tokamak on Kelvin-Helmholtz instability caused by toroidal rotation. The effect of radial distribution of plasma rotational velocity on stability is also examine for comparison. It is found that within the range of tokamak parameters the only radial distribution of plasma rotational velocity cannot induce Kelvin-Helmholtz instability. On the contrary, when there is a radial distribution of plasma density, i.e. P 01 =P 0 e -tx and V 0 1 = const, plasma becomes unstable, and instability will increase proportionally to the value of t. Meanwhile when the value of t remains constant, the instability growth rate will decrease if P 0 grows or the distance between plasma and wall of container decreases too. It shows that the Kelvin-Helmoltz instability is not only influenced by the steepness of density profile but also by the inertia of plasma in central region, which is helpful for depressing the instability. (author). 5 refs, 4 figs, 2 tabs

Impaired plasma lipid profiles in acute hepatitis

Directory of Open Access Journals (Sweden)

Wang Yongzhong

2010-01-01

Full Text Available Abstract The present study examined plasma lipid profiles in thirty patients suffered from acute viral hepatitis. Patients' blood samples were collected at both the debut and recovery of diseases. Thirty sex and age matched normal subjects were included as controls. Plasma total triglycerides (TG, total cholesterol, high density lipoprotein cholesterol (HDL-C, low density lipoprotein cholesterol (LDL-C, apolipoprotein AI (ApoAI, apolipoprotein B (ApoB, lipoprotein (a (Lp(a, blood coagulation status including prothrombin complex activity and activated partial tromboplastin time (APTT, and hepatic functions were determined by the automatic biochemical analytical instrument. It demonstrated that plasma levels of total cholesterol, HDL-C and apoAI were significantly lower in the patients at the acute phase of hepatitis than those in normal subjects, whereas plasma levels of TG and LDL-C were obviously higher in the patients than in normal subjects (P

Optimization and control of plasma shape and current profile in non-circular cross-section tokamaks

International Nuclear Information System (INIS)

Moore, R.W.; Bernard, L.C.; Chan, V.S.

1981-01-01

Tokamaks with elongated, non-circular cross-sections are under consideration as fusion reactors because they have the potential for stable operation at high β. Ideal MHD theory, however, predicts that careful current profile control will be required to achieve the potential high-β advantages of non-circular cross-sections. In this paper, high-β equilibria which are stable to all ideal MHD modes are found by optimizing the plasma shape and current profile for doublets, up-down asymmetric dees, and symmetric dees. The ideal MHD stability of these equilibria for low toroidal mode number n is analysed with a global MHD stability code, GATO. The stability to high-n modes is analysed with a localized ballooning code, BLOON. The attainment of high β is facilitated by an automated optimization search on shape and current parameters. The equilibria are calculated with a free-boundary equilibrium code using coils appropriate for the Doublet III experimental device. The optimal equilibria are characterized by broad current profiles with values of βsub(poloidal) approximately equal to 1. Experimental realization of the shapes and current profiles giving the highest β limits is explored with a 1 1/2-D transport code, which simulates the time evolution of the 2-D MHD equilibrium while calculating consistent current profiles from a 1-D transport model. Transport simulations indicate that nearly optimal shapes may be obtained provided that the currents in the field-shaping coils are appropriately programmed and the plasma current profile is sufficiently broad. Obtaining broad current profiles is possible by current ramping, neutral-beam heating, and electron-cyclotron heating. With combinations of these techniques it is possible to approach the optimum β predicted by the MHD theory. (author)

Studies on plasma profiles and its effect on dust charging in hydrogen plasma

Science.gov (United States)

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

2010-02-01

Plasma profiles and its influence on dust charging are studied in hydrogen plasma. The plasma is produced in a high vacuum device by a hot cathode discharge method and is confined by a cusped magnetic field cage. A cylindrical Espion advanced Langmuir probe having 0.15 mm diameter and 10.0 mm length is used to study the plasma parameters for various discharge conditions. Optimum operational discharge parameters in terms of charging of the dust grains are studied. The charge on the surface of the dust particle is calculated from the capacitance model and the current by the dust grains is measured by the combination of a Faraday cup and an electrometer. Unlike our previous experiments in which dust grains were produced in-situ, here a dust dropper is used to drop the dust particles into the plasma.

Studies on plasma profiles and its effect on dust charging in hydrogen plasma

International Nuclear Information System (INIS)

Kakati, B; Kausik, S S; Saikia, B K; Bandyopadhay, M

2010-01-01

Plasma profiles and its influence on dust charging are studied in hydrogen plasma. The plasma is produced in a high vacuum device by a hot cathode discharge method and is confined by a cusped magnetic field cage. A cylindrical Espion advanced Langmuir probe having 0.15 mm diameter and 10.0 mm length is used to study the plasma parameters for various discharge conditions. Optimum operational discharge parameters in terms of charging of the dust grains are studied. The charge on the surface of the dust particle is calculated from the capacitance model and the current by the dust grains is measured by the combination of a Faraday cup and an electrometer. Unlike our previous experiments in which dust grains were produced in-situ, here a dust dropper is used to drop the dust particles into the plasma.

Effects of pressure profile and plasma shaping on the n=1 internal kink mode in JT-60/JT-60U pellet fuelled plasmas

International Nuclear Information System (INIS)

Ozeki, Takahisa; Azumi, Masafumi

1990-10-01

The stability of the n=1 internal kink mode in a tokamak is numerically analyzed for plasmas with a centrally peaked pressure profile. These studies are carried out with the strongly peaked pressure inside the q=1 surface, which is based on the experimentally observed plasmas by means of injections of hydrogen-ice pellets in JT-60 tokamak. The effects of peaked pressure and shaping, i.e., elongation and triangularity, are also studied for JT-60U tokamak. The plasma with the strongly peaked pressure profile has higher critical value of poloidal beta defined within the q=1 surface than that with a parabolic pressure profile. Though the beta limit reduces with the increase of the elongation, the plasma with the peaked pressure profile has larger improvement due to the triangularity than that with the parabolic pressure profile. To access the second stability of the n=1 internal kink mode, the plasma with a flat pressure profile and the large minor radius of the q=1 surface is effective. (author)

Evolution of the electron temperature profile of ohmically heated plasmas in TFTR

International Nuclear Information System (INIS)

Taylor, G.; Efthimion, P.C.; Arunasalam, V.

1985-08-01

Blackbody electron cyclotron emission was used to ascertain and study the evolution and behavior of the electron temperature profile in ohmically heated plasmas in the Tokamak Fusion Test Reactor (TFTR). The emission was measured with absolutely calibrated millimeter wavelength radiometers. The temperature profile normalized to the central temperature and minor radius is observed to broaden substantially with decreasing limiter safety factor q/sub a/, and is insensitive to the plasma minor radius. Sawtooth activity was seen in the core of most TFTR discharges and appeared to be associated with a flattening of the electron temperature profile within the plasma core where q less than or equal to 1. Two types of sawtooth behavior were identified in large TFTR plasmas (minor radius, a less than or equal to 0.8 m) : a typically 35 to 40 msec period ''normal'' sawtooth, and a ''compound'' sawtooth with 70 to 80 msec period

Fast Plasma Potential Measurements Using an Emissive Probe

Science.gov (United States)

Ready, Amanda; Clark, Michael; Endrizzi, Douglass; Forest, Cary; Peterson, Ethan

2017-10-01

A heated emissive probe was developed for making direct plasma potential (Vp) measurements in rapidly fluctuating plasmas. Previous experiments on the Big Red Ball (BRB) were hindered by sudden potential drops, making Langmuir measurements of the plasma potential difficult. DC heating of a tungsten filament to emission allowed for fast (4 MHz) floating potential measurements that closely matched Vp. Two BRB experiments currently use the emissive probe. The investigation of unmagnetized, collisionless shocks used plasma potential measurements to study the sub-structure of strong plasma shocks. A separate investigation of emulated magnetospheres in laboratory plasmas used the plasma potential to map the equilibria and instabilities in the electric field of such structures. Results showing electric field measurements and comparison with cold Langmuir measurements will be presented. Future plans for probe modifications and applications to other experiments on the BRB will also be shown.

Parallel Transport and Profile of Boundary Plasma with a Low Recycling Wall

Energy Technology Data Exchange (ETDEWEB)

Tang, X.; Guo, Z., E-mail: xtang@lanl.gov [Los Alamos National Laboratory, Los Alamos (United States)

2012-09-15

Full text: Reduction of wall recycling by, for example, a flowing liquid surface at the divertor and first wall, holds the promise of accessing the distinct tokamak reactor operational mode with boundary plasmas of high temperature and low density. Earlier work has indicated that such a boundary plasma would reduce the temperature gradient across the entire plasma and hence remove the primary micro-instability drive responsibly for anomalous particle and energy transport. Here we present a systematic study solving the kinetic equations both analytically and numerically, with and without Coulomb collision. The distinct roles of magnetic field strength modulation and the ambipolar electric field on the electron and ion distribution functions are clarified. The resulting behavior on plasma profile and parallel heat flux, which are often surprising and counter the expectations from the collisional fluid models, on which previous work were based, are explained both intuitively and with a contrast between analytical calculation and numerical simulations. The transport-induced plasma instabilities, and their essential role in maintaining ambipolarity, are clarified, along with the subtle effect of Coulomb collision on electron temperature and wall potential as small but finite collisionality is taken into account. (author)

Consequences of nonlinear heat transport laws on expected plasma profiles

International Nuclear Information System (INIS)

Lackner, K.

1987-03-01

The expected variation of plasma pressure profiles against changes in power deposition is investigated by using a simple linear heat transport law as well as a quadratic one. Applying the quadratic transport law it can be shown that the stiffening of the resulting profiles is sufficient to understand the experimentally measured phenomenon of 'profile consistence' without further assumptions of nonlocal effects. (orig.) [de

Line profiles of hydrogenic ions from high-temperature and high-density plasmas

International Nuclear Information System (INIS)

Hou Qing; Li Jianming

1991-01-01

Applying the Hooper's first-order theory, the authors calculate the static micro-electric field distributions in plasmas containing various multiply-charged ions. The influences of the impurity concentrations on the micro electric field distributions and on the Lyman profiles (n→1) from hydrogenic ions are analysed. Based on the optical-thin line profiles, the radiation transfer equation in sphere plasmas with various optical depths is solved. The results confirm that the opacity-broadening of the line profiles has almost no effect on the separation of Lyman β splitted peaks. Such separation is determined by electric field at which the static micro-electric field distribution has a maximum. The separation can be utilized for spatially resolved and temporally resolved density diagnostic of fusion plasmas

Potential profile near singularity point in kinetic Tonks-Langmuir discharges as a function of the ion sources temperature

Science.gov (United States)

Kos, L.; Tskhakaya, D. D.; Jelić, N.

2011-05-01

A plasma-sheath transition analysis requires a reliable mathematical expression for the plasma potential profile Φ(x) near the sheath edge xs in the limit ɛ ≡λD/ℓ =0 (where λD is the Debye length and ℓ is a proper characteristic length of the discharge). Such expressions have been explicitly calculated for the fluid model and the singular (cold ion source) kinetic model, where exact analytic solutions for plasma equation (ɛ =0) are known, but not for the regular (warm ion source) kinetic model, where no analytic solution of the plasma equation has ever been obtained. For the latter case, Riemann [J. Phys. D: Appl. Phys. 24, 493 (1991)] only predicted a general formula assuming relatively high ion-source temperatures, i.e., much higher than the plasma-sheath potential drop. Riemann's formula, however, according to him, never was confirmed in explicit solutions of particular models (e.g., that of Bissell and Johnson [Phys. Fluids 30, 779 (1987)] and Scheuer and Emmert [Phys. Fluids 31, 3645 (1988)]) since "the accuracy of the classical solutions is not sufficient to analyze the sheath vicinity" [Riemann, in Proceedings of the 62nd Annual Gaseous Electronic Conference, APS Meeting Abstracts, Vol. 54 (APS, 2009)]. Therefore, for many years, there has been a need for explicit calculation that might confirm the Riemann's general formula regarding the potential profile at the sheath edge in the cases of regular very warm ion sources. Fortunately, now we are able to achieve a very high accuracy of results [see, e.g., Kos et al., Phys. Plasmas 16, 093503 (2009)]. We perform this task by using both the analytic and the numerical method with explicit Maxwellian and "water-bag" ion source velocity distributions. We find the potential profile near the plasma-sheath edge in the whole range of ion source temperatures of general interest to plasma physics, from zero to "practical infinity." While within limits of "very low" and "relatively high" ion source temperatures

Surface density profile and surface tension of the one-component classical plasma

International Nuclear Information System (INIS)

Ballone, P.; Senatore, G.; Trieste Univ.; Tosi, M.P.; Oxford Univ.

1982-08-01

The density profile and the interfacial tension of two classical plasmas in equilibrium at different densities are evaluated in the square-density-gradient approximation. For equilibrium in the absence of applied external voltage, the profile is oscillatory in the higher-density plasma and the interfacial tension is positive. The amplitude and phase of these oscillations and the magnitude of the interfacial tension are related to the width of the background profile. Approximate representations of the equilibrium profile by matching of its asymptotic forms are analyzed. A comparison with computer simulation data and a critical discussion of a local-density theory are also presented. (author)

Electron cyclotron heating for current profile control of non-circular plasmas

International Nuclear Information System (INIS)

Chan, V.S.; Davidson, R.; Guest, G.; Hacker, M.; Miller, L.

1981-01-01

Electron Cyclotron Heating (ECH) offers a promising approach to modifying the radial profiles of electron temperature and plasma current in tokamaks to increase the ideal MHD beta limits and permit experimental access to particular noncircular cross-section tokamaks that cannot be achieved with the peaked current profiles characteristic of ohmically heated tokamaks. We use a one-and-one-half-dimensional, time-dependent transport model that incorporates a self-consistent model of electron cyclotron power absorption to study the temporal evolution of electron temperature and plasma current profiles and the resulting noncircular equilibria. Startup scenarios for high-beta dees and doublets are investigated with this transport modeling

Collector floating potentials in a discharge plasma

International Nuclear Information System (INIS)

Cercek, M.; Gyergyek, T.

1999-01-01

We present the results of a study on electrode floating potential formation in a hot-cathode discharge plasma. The electron component of the plasma is composed from two populations. The high temperature component develops from primary electrons and the cool component from secondary electrons born by ionisation of cold neutral gas. A static, kinetic plasma-sheath model is use to calculate the pre-sheath potential and the floating potential of the electrode. For hot primary electrons a truncated Maxwellian distribution is assumed. The plasma system is also modelled numerically with a dynamic, electrostatic particle simulation. The plasma source injects temporally equal fluxes of ions and electrons with half-Maxwellian velocities. Again, the hot electron distribution is truncated in the high velocity tail. The plasma parameters, such as ion temperature and mass, electron temperatures, discharge voltages, etc. correspond to experimental values. The experimental measurements of the electrode floating potential are performed in weakly magnetised plasma produced with hot cathode discharge in argon gas. Theoretical, simulation and experimental results are compared and they agree very well.(author)

Influence of continuously-varing profile on the diocotron instability in a non neutral plasma column

International Nuclear Information System (INIS)

Asgary, H. R.; Maraghehechi, Behrooz; Rafii, Mahboobeh

2003-01-01

In this paper we investigate the theoretical method related to density profile effect on diocotron instability in nonrelativistic state in non neutral plasma column. At first we introduce non neutral plasma and diocotron instability then we extract instability equation and we will investigate plasma stability with special profile density

Density profile measurements from a two-gun plasma focus device

International Nuclear Information System (INIS)

Tzeng, C.C.; Yen, C.K.; Yeh, T.R.; Kuo, Y.Y.; Shang, D.J.; Yu, Y.Z.; Hou, W.S.

1990-01-01

The dynamics of the plasma evolution in a two-gun plasma focus device has been studied using the laser shadowgraphy as well as the laser interferometry. The experiments were carried out from a 700 kJ two-gun plasma focus device reported earlier, which consisted of a pair of Mather type coaxial electrodes connected muzzle to muzzle. Previous results indicated that the simultaneous formation of the two deuterium plasma foci occurred earlier and then after ∼ 100 ns a disk-shaped plasma of ∼ 1.5 cm in diameter appeared in the middle region between the anodes. It is, therefore, the authors' goal to study the density profiles in the plasma foci and the middle region in order to understand further the formation of the plasma foci and their time evolution. The laser shadowgraphy was done with a XeCl excimer pumped dye laser system which operated at 550 nm with pulse width of ∼ 10 ns. The laser interferometry, on the other hand, was carried out using a TEA-TEA oscillator-amplifier N 2 -laser system with 337.1 nm and subnano-second pulse width. Both results show that the maximum electron density is ≥2 x 10 19 cm -3 and, in addition, the growth of the hydrodynamic instabilities are observed. These results together with the detailed density profiles are presented and discussed

Towards Current Profile Control in ITER: Potential Approaches and Research Needs

Science.gov (United States)

Schuster, E.; Barton, J. E.; Wehner, W. P.

2014-10-01

Many challenging plasma control problems still need to be addressed in order for the ITER Plasma Control System (PCS) to be able to successfully achieve the ITER project goals. For instance, setting up a suitable toroidal current density profile is key for one possible advanced scenario characterized by noninductive sustainment of the plasma current and steady-state operation. The nonlinearity and high dimensionality exhibited by the plasma demand a model-based current-profile control synthesis procedure that can accommodate this complexity through embedding the known physics within the design. The development of a model capturing the dynamics of the plasma relevant for control design enables not only the design of feedback controllers for regulation or tracking but also the design of optimal feedforward controllers for a systematic model-based approach to scenario planning, the design of state estimators for a reliable real-time reconstruction of the plasma internal profiles based on limited and noisy diagnostics, and the development of a fast predictive simulation code for closed-loop performance evaluation before implementation. Progress towards control-oriented modeling of the current profile evolution and associated control design has been reported following both data-driven and first-principles-driven approaches. An overview of these two approaches will be provided, as well as a discussion on research needs associated with each one of the model applications described above. Supported by the US Department of Energy under DE-SC0001334 and DE-SC0010661.

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-04-01

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

Spectrally resolved measurements of the terahertz beam profile generated from a two-color air plasma

DEFF Research Database (Denmark)

Pedersen, Pernille Klarskov; Zalkovskij, Maksim; Strikwerda, Andrew

2014-01-01

Using a THz camera and THz bandpass filters, we measure the frequency - resolved beam profile emitted from a two - color air plasma. We observe a frequency - independent emission angle from the plasma .......Using a THz camera and THz bandpass filters, we measure the frequency - resolved beam profile emitted from a two - color air plasma. We observe a frequency - independent emission angle from the plasma ....

Kinetic Profiles in NSTX Plasmas

International Nuclear Information System (INIS)

Bell, R.E.; LeBlanc, B.P.; Bourdelle, C.; Ernst, D.R.; Fredrickson, E.D.; Gates, D.A.; Hosea, J.C.; Johnson, D.W.; Kaye, S.M.; Maingi, R.; Medley, S.; Menard, J.E.; Mueller, D.; Ono, M.; Paoletti, F.; Peng, M.; Sabbagh, S.A.; Stutman, D.; Swain, D.W.; Synakowski, E.J.; Wilson, J.R.

2001-01-01

The National Spherical Torus Experiment (NSTX) is a low aspect ratio (R/a approximately 1.3) device with auxiliary heating from neutral-beam injection (NBI) and high-harmonic fast-wave heating (HHFW). Typical NSTX parameters are R(subscript ''0'') = 85 cm, a = 67 cm, I(subscript ''p'') = 0.7-1.4 MA, B(subscript ''phi'') = 0.25-0.45 T. Three co-directed deuterium neutral-beam sources have injected P(subscript ''NB'') less than or equal to 4.7 MW. HHFW plasmas typically have delivered P(subscript ''RF'') less than or equal to 3 MW. Important to the understanding of NSTX confinement are the new kinetic profile diagnostics: a multi-pulse Thomson scattering system (MPTS) and a charge-exchange recombination spectroscopy (CHERS) system. The MPTS diagnostic currently measures electron density and temperature profiles at 30 Hz at ten spatial locations. The CHERS system has recently become available to measure carbon ion temperature and toroidal flow at 17 radial positions spanning the outer half of the minor radius with 20 msec time resolution during NBI. Experiments conducted during the last year have produced a wide range of kinetic profiles in NSTX. Some interesting examples are presented below

Simulation of the electric potential and plasma generation coupling in magnetron sputtering discharges

Science.gov (United States)

Trieschmann, Jan; Krueger, Dennis; Schmidt, Frederik; Brinkmann, Ralf Peter; Mussenbrock, Thomas

2016-09-01

Magnetron sputtering typically operated at low pressures below 1 Pa is a widely applied deposition technique. For both, high power impulse magnetron sputtering (HiPIMS) as well as direct current magnetron sputtering (dcMS) the phenomenon of rotating ionization zones (also referred to as spokes) has been observed. A distinct spatial profile of the electric potential has been associated with the latter, giving rise to low, mid, and high energy groups of ions observed at the substrate. The adherent question of which mechanism drives this process is still not fully understood. This query is approached using Monte Carlo simulations of the heavy particle (i.e., ions and neutrals) transport consistently coupled to a pre-specified electron density profile via the intrinsic electric field. The coupling between the plasma generation and the electric potential, which establishes correspondingly, is investigated. While the system is observed to strive towards quasi-neutrality, distinct mechanisms governing the shape of the electric potential profile are identified. This work is supported by the German Research Foundation (DFG) in the frame of the transregional collaborative research centre TRR 87.

Real-time control of the plasma density profile on ASDEX upgrade

International Nuclear Information System (INIS)

Mlynek, Alexander

2010-01-01

The tokamak concept currently is the most promising approach to future power generation by controlled thermonuclear fusion. The spatial distribution of the particle density in the toroidally confined fusion plasma is of particular importance. This thesis work therefore focuses on the question as to what extent the shape of the density profile can be actively controlled by a feedback loop in the fusion experiment ASDEX Upgrade. There are basically two essential requirements for such feedback control of the density profile, which has been experimentally demonstrated within the scope of this thesis work: On the one hand, for this purpose the density profile must be continuously calculated under real-time constraints during a plasma discharge. The calculation of the density profile is based on the measurements of a sub-millimeter interferometer, which provides the line-integrated electron density along 5 chords through the plasma. Interferometric density measurements can suffer from counting errors by integer multiples of 2π when detecting the phase difference between a probing and a reference beam. As such measurement errors have severe impact on the reconstructed density profile, one major part of this work consists in the development of new readout electronics for the interferometer, which allows for detection of such measurement errors in real-time with high reliability. A further part of this work is the design of a computer algorithm which reconstructs the spatial distribution of the plasma density from the line-integrated measurements. This algorithm has to be implemented on a computer which communicates the measured data to other computers in real-time, especially to the tokamak control system. On the other hand, a second fundamental requirement for the successful implementation of a feedback controller is the identification of at least one actuator which enables a modification of the density profile. Here, electron cyclotron resonance heating (ECRH) has been

High precision measurement of fuel density profiles in nuclear fusion plasmas

NARCIS (Netherlands)

Svensson, J.; von Hellermann, M.; Konig, R.

2002-01-01

This paper presents a method for deducing fuel density profiles of nuclear fusion plasmas in realtime during an experiment. A Multi Layer Perceptron (MLP) neural network is used to create a mapping between plasma radiation spectra and indirectly deduced hydrogen isotope densities. By combining

Chromatographic profiles of blood plasma free oligosaccharides in patients with cardiovascular disease

Directory of Open Access Journals (Sweden)

I. U. Pismenetskaya

2015-03-01

Full Text Available Free oligosaccharides (FOS are unbound structural analogs of glycans of glycoconjugates. There are several sources of them inside the cell: 1 multistep pathways of N-glycosylation, 2 the cell quality control and endoplastic reticulum-associated degradation of mis-glycosylated and/or misfolded glycoproteins, 3 lysosomal degradation of mature glycoconjugates. Some of these FOS are the earliest indicators of potential glycosylation alterations that would be revealed in the course of the cell quality control and the endoplastic reticulum-associated degradation. Ischemia and hypertension cause stress of intracellular organelles leading to disruption of their functions. The main objective of the work was the characterization of free oligosaccharides (FOS in plasma obtained from patients with cardiovascular diseases compared to those from healthy subjects to evaluate the potential of these compounds for diagnostics. Chromatographic profiles of FOS composed of 4–12 monosaccharides were obtained and analyzed for quantitative and qualitative differences between the samples. After plasma deproteinization and FOS purification the oligosaccharides were labelled with anthranilic acid (2-AA, separated into the neutral and charged with QAE Sephadex (Q25-120 chromatography and analysed using high-performance liquid chromatography (HPLC. Glucose unit values were determined following comparison with a 2-AA-labelled glucose oligomer ladder derived from a partial hydrolysate of dextran as an external standard. The data were collected and processed using Empower software. The charged FOS were digested with the sialidase from Arthrobacter ureafaciens. 2-AA – labelled free oligosaccharides from transferrin were used as an external standard for the structure decoding. The profiles obtained were compared with intracellular free oligosaccharides of known structures and with the glycan structures and their descriptions in the databases GlycoBase and EUROCarbDB. These

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)

Analyses of plasma parameter profiles in JT-60U

International Nuclear Information System (INIS)

Shirai, Hiroshi; Shimizu, Katsuhiro; Hayashi, Nobuhiko

2001-01-01

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

Stationary neoclassical profiles of plasma parameters in stellarators

International Nuclear Information System (INIS)

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

1991-01-01

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

Density profile effects on confinement and MHD stability of currentless NBI plasmas in Heliotron E

International Nuclear Information System (INIS)

Sudo, Shigeru; Zushi, Hideki; Kondo, Katsumi

1993-01-01

Density profile effects on confinement and MHD stability of currentless NBI plasmas in Heliotron E are studied. The peaked density profile produced by pellet injection increases the stored energy by 20-30% compared to the gas puffed plasmas which obey the empirical stellarator/heliotron scaling in a moderate density range. In contrast to confinement, the peaked pressure profile tends to destabilize the plasma. By limiter insertion, MHD instability occurs (seems to locate near ι/2π=1) even in case of low β (β 0 ≤1%, where β 0 is the central β value) plasmas. On the other hand, the mode of m/n=3/2 at ι/2π=2/3, seems to be a key parameter to the major MHD instability in case of high β (β 0 ≥2%) plasmas. (author)

Fluid and gyrokinetic modelling of particle transport in plasmas with hollow density profiles

International Nuclear Information System (INIS)

Tegnered, D; Oberparleiter, M; Nordman, H; Strand, P

2016-01-01

Hollow density profiles occur in connection with pellet fuelling and L to H transitions. A positive density gradient could potentially stabilize the turbulence or change the relation between convective and diffusive fluxes, thereby reducing the turbulent transport of particles towards the center, making the fuelling scheme inefficient. In the present work, the particle transport driven by ITG/TE mode turbulence in regions of hollow density profiles is studied by fluid as well as gyrokinetic simulations. The fluid model used, an extended version of the Weiland transport model, Extended Drift Wave Model (EDWM), incorporates an arbitrary number of ion species in a multi-fluid description, and an extended wavelength spectrum. The fluid model, which is fast and hence suitable for use in predictive simulations, is compared to gyrokinetic simulations using the code GENE. Typical tokamak parameters are used based on the Cyclone Base Case. Parameter scans in key plasma parameters like plasma β, R/L T , and magnetic shear are investigated. It is found that β in particular has a stabilizing effect in the negative R/L n region, both nonlinear GENE and EDWM show a decrease in inward flux for negative R/L n and a change of direction from inward to outward for positive R/L n . This might have serious consequences for pellet fuelling of high β plasmas. (paper)

Heavy ion beam probe development for the plasma potential measurement on the TUMAN-3M tokamak

International Nuclear Information System (INIS)

Askinazi, L.G.; Kornev, V.A.; Lebedev, S.V.; Tukachinsky, A.S.; Zhubr, N.A.; Dreval, N.B.; Krupnik, L.I.

2004-01-01

The peculiarities of the heavy ion beam probe implementation on the small aspect ratio tokamak TUMAN-3M are analyzed. The toroidal displacement of beam trajectory due to the high I pl /B tor ratio is taken into account when designing the layout of the diagnostic. Numerical calculation of beam trajectories using realistic configuration of TUMAN-3M magnetic fields and parabolic plasma current profile resulted in proper adjustment of probing and detection parameters (probing ion material, energy, entrance angles, detector location, and orientation). Secondary ion energy analyzer gain functions G and F were measured in situ using neutral hydrogen puffed in the tokamak vessel as a target for secondary ions production. The detector unit featured split-plate design and had additional electrodes for secondary electron emission suppression. As a result, the diagnostic is now capable of plasma potential evolution measurement and is sensitive enough to trace the potential profile evolution at the L-H mode transition

Longitudinal plasma metabolic profiles, infant feeding, and islet autoimmunity in the MIDIA study.

Science.gov (United States)

Jørgenrud, Benedicte; Stene, Lars C; Tapia, German; Bøås, Håkon; Pepaj, Milaim; Berg, Jens P; Thorsby, Per M; Orešič, Matej; Hyötyläinen, Tuulia; Rønningen, Kjersti S

2017-03-01

The aim of this study was to investigate the longitudinal plasma metabolic profiles in healthy infants and the potential association with breastfeeding duration and islet autoantibodies predictive of type 1 diabetes. Up to four longitudinal plasma samples from age 3 months from case children who developed islet autoimmunity (n = 29) and autoantibody-negative control children (n = 29) with the HLA DR4-DQ8/DR3-DQ2 genotype were analyzed using two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer for detection of small polar metabolites. Plasma metabolite levels were found to depend strongly on age, with fold changes varying up to 50% from age 3 to 24 months (p polar metabolites changed with age during early childhood, independent of later islet autoimmunity status and sex. Breastfeeding was associated with higher levels of branched-chain amino acids, and lower levels of methionine and 3,4-dihydroxybutyric acid. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Plasma and erythrocyte phospholipid fatty acid profile in professional basketball and football players.

Science.gov (United States)

Tepsic, Jasna; Vucic, Vesna; Arsic, Aleksandra; Blazencic-Mladenovic, Vera; Mazic, Sanja; Glibetic, Marija

2009-10-01

The effect of intensive long-term physical activity on phospholipid fatty acid (FA) composition has not been studied thoroughly. We determined plasma and erythrocyte phospholipid FA status of professional basketball and football players. Our results showed differences in plasma FA profile not only between sportsmen and sedentary subjects, but also between two groups of sportsmen. Plasma FA profile in basketball players showed significantly higher proportion of n-6 FA (20:3, 20:4, and 22:4) and total polyunsaturated FA (PUFA) than controls, while football players had higher palmitoleic acid (16:1) than basketball players and controls. Total PUFA and 22:4 were also higher in basketball than in football players. Erythrocyte FA profile showed no differences between football players and controls. However, basketball players had higher proportion of 18:0 than controls, higher saturated FA and lower 18:2 than two other groups, and higher 22:4 than football players. These findings suggest that long-term intensive exercise and type of sport influence FA profile.

Pressure profiles of plasmas confined in the field of a magnetic dipole

International Nuclear Information System (INIS)

Davis, Matthew S; Mauel, M E; Garnier, Darren T; Kesner, Jay

2014-01-01

Equilibrium pressure profiles of plasmas confined in the field of a dipole magnet are reconstructed using magnetic and x-ray measurements on the levitated dipole experiment (LDX). LDX operates in two distinct modes: with the dipole mechanically supported and with the dipole magnetically levitated. When the dipole is mechanically supported, thermal particles are lost along the field to the supports, and the plasma pressure is highly peaked and consists of energetic, mirror-trapped electrons that are created by electron cyclotron resonance heating. By contrast, when the dipole is magnetically levitated losses to the supports are eliminated and particles are lost via slower cross-field transport that results in broader, but still peaked, plasma pressure profiles. (paper)

Plasma Free Amino Acid Profiling of Five Types of Cancer Patients and Its Application for Early Detection

Science.gov (United States)

Miyagi, Yohei; Higashiyama, Masahiko; Gochi, Akira; Akaike, Makoto; Ishikawa, Takashi; Miura, Takeshi; Saruki, Nobuhiro; Bando, Etsuro; Kimura, Hideki; Imamura, Fumio; Moriyama, Masatoshi; Ikeda, Ichiro; Chiba, Akihiko; Oshita, Fumihiro; Imaizumi, Akira; Yamamoto, Hiroshi; Miyano, Hiroshi; Horimoto, Katsuhisa; Tochikubo, Osamu; Mitsushima, Toru; Yamakado, Minoru; Okamoto, Naoyuki

2011-01-01

Background Recently, rapid advances have been made in metabolomics-based, easy-to-use early cancer detection methods using blood samples. Among metabolites, profiling of plasma free amino acids (PFAAs) is a promising approach because PFAAs link all organ systems and have important roles in metabolism. Furthermore, PFAA profiles are known to be influenced by specific diseases, including cancers. Therefore, the purpose of the present study was to determine the characteristics of the PFAA profiles in cancer patients and the possibility of using this information for early detection. Methods and Findings Plasma samples were collected from approximately 200 patients from multiple institutes, each diagnosed with one of the following five types of cancer: lung, gastric, colorectal, breast, or prostate cancer. Patients were compared to gender- and age- matched controls also used in this study. The PFAA levels were measured using high-performance liquid chromatography (HPLC)–electrospray ionization (ESI)–mass spectrometry (MS). Univariate analysis revealed significant differences in the PFAA profiles between the controls and the patients with any of the five types of cancer listed above, even those with asymptomatic early-stage disease. Furthermore, multivariate analysis clearly discriminated the cancer patients from the controls in terms of the area under the receiver-operator characteristics curve (AUC of ROC >0.75 for each cancer), regardless of cancer stage. Because this study was designed as case-control study, further investigations, including model construction and validation using cohorts with larger sample sizes, are necessary to determine the usefulness of PFAA profiling. Conclusions These findings suggest that PFAA profiling has great potential for improving cancer screening and diagnosis and understanding disease pathogenesis. PFAA profiles can also be used to determine various disease diagnoses from a single blood sample, which involves a relatively simple

Plasma free amino acid profiling of five types of cancer patients and its application for early detection.

Directory of Open Access Journals (Sweden)

Yohei Miyagi

Full Text Available BACKGROUND: Recently, rapid advances have been made in metabolomics-based, easy-to-use early cancer detection methods using blood samples. Among metabolites, profiling of plasma free amino acids (PFAAs is a promising approach because PFAAs link all organ systems and have important roles in metabolism. Furthermore, PFAA profiles are known to be influenced by specific diseases, including cancers. Therefore, the purpose of the present study was to determine the characteristics of the PFAA profiles in cancer patients and the possibility of using this information for early detection. METHODS AND FINDINGS: Plasma samples were collected from approximately 200 patients from multiple institutes, each diagnosed with one of the following five types of cancer: lung, gastric, colorectal, breast, or prostate cancer. Patients were compared to gender- and age- matched controls also used in this study. The PFAA levels were measured using high-performance liquid chromatography (HPLC-electrospray ionization (ESI-mass spectrometry (MS. Univariate analysis revealed significant differences in the PFAA profiles between the controls and the patients with any of the five types of cancer listed above, even those with asymptomatic early-stage disease. Furthermore, multivariate analysis clearly discriminated the cancer patients from the controls in terms of the area under the receiver-operator characteristics curve (AUC of ROC >0.75 for each cancer, regardless of cancer stage. Because this study was designed as case-control study, further investigations, including model construction and validation using cohorts with larger sample sizes, are necessary to determine the usefulness of PFAA profiling. CONCLUSIONS: These findings suggest that PFAA profiling has great potential for improving cancer screening and diagnosis and understanding disease pathogenesis. PFAA profiles can also be used to determine various disease diagnoses from a single blood sample, which involves a

Relativistic self-focusing of intense laser beam in thermal collisionless quantum plasma with ramped density profile

Directory of Open Access Journals (Sweden)

S. Zare

2015-04-01

Full Text Available Propagation of a Gaussian x-ray laser beam has been analyzed in collisionless thermal quantum plasma with considering a ramped density profile. In this density profile due to the increase in the plasma density, an earlier and stronger self-focusing effect is noticed where the beam width oscillates with higher frequency and less amplitude. Moreover, the effect of the density profile slope and the initial plasma density on the laser propagation has been studied. It is found that, by increasing the initial density and the ramp slope, the laser beam focuses faster with less oscillation amplitude, smaller laser spot size and more oscillations. Furthermore, a comparison is made among the laser self-focusing in thermal quantum plasma, cold quantum plasma and classical plasma. It is realized that the laser self-focusing in the quantum plasma becomes stronger in comparison with the classical regime.

Electron density and temperature profile diagnostics for C-2 field reversed configuration plasmas

Energy Technology Data Exchange (ETDEWEB)

Deng, B. H.; Kinley, J. S.; Schroeder, J. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

2012-10-15

The 9-point Thomson scattering diagnostic system for the C-2 field reversed configuration plasmas is improved and the measured electron temperature profiles are consistent with theoretical expectations. Rayleigh scattering revealed a finite line width of the ruby laser emission, which complicates density calibration. Taking advantage of the plasma wobble motion, density profile reconstruction accuracy from the 6-chord two-color CO{sub 2}/HeNe interferometer data is improved.

Measurements of Electron Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

Science.gov (United States)

Oh, Jaechul; Weaver, J. L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Karasik, M.; Chan, L.-Y.; Serlin, V.; Phillips, L.

2013-10-01

Knowing spatial profiles of electron density (ne) in the underdense coronal region (n Nike LPI experiment, a side-on grid imaging refractometer (GIR) was deployed for measuring the underdense plasma profiles. Plasmas were produced from flat CH targets illuminated by Nike KrF laser with total energies up to 1 kJ of 0.5 ~ 1 nsec FWHM pulses. The GIR resolved ne up to 3 ×1021 /cm3 in space taking 2D snapshot images of probe laser (λ = 263 nm, Δt = 10 ps) beamlets (50 μm spacing) refracted by the plasma at a selected time during the laser illumination. The individual beamlet transmittances were also measured for Te estimation. Time-resolved spectrometers with an absolute-intensity-calibrated photodiode array and a streak camera simultaneously detected light emission from the plasma in spectral ranges relevant to Raman (SRS) and two plasmon decay instabilities. The measured spatial profiles are compared with simulation results from the FAST3D radiation hydrocode and their effects on the LPI observations are investigated. Work supported by DoE/NNSA and performed at Naval Research Laboratory.

Modification of K-line emission profiles in laser-created solid-density plasmas

International Nuclear Information System (INIS)

Sengebusch, A.; Reinholz, H.; Roepke, G.

2010-01-01

Complete text of publication follows. X-ray emissions in the keV energy range have shown to be suitable radiation to investigate the properties of laser-created solid-density plasmas. We use the modifications of inner shell transitions due to the environment to characterize these plasmas. A theoretical treatment of spectral line profiles based on a self-consistent ion sphere model is applied on moderately ionized mid-Z materials, such as titanium, silicon and chlorine. We observe large contributions of satellite transitions due to M-shell ionization and excitation. To determine the composition a mixture of various excited and ionized ionic states embedded in a plasma has to be considered. Plasma polarization effects that cause shifts of the emission and ionization energies are taken into account. K-line profiles are calculated for bulk temperatures up to 100 eV and free electron densities up to 10 24 cm -3 in order to analyze recent measurements with respect to the plasma parameters of electron heated target regions. Moreover, in high-intensity laser-matter interactions, inevitable prepulses are likely to create preplasma and shocks within the target before the main pulse arrives. We investigate the influence of density gradients due to prepulses on the spectral profiles. Further, radial bulk temperature distributions as well the composition of the created warm dense matter are inferred.

Plasma Free Amino Acid Profiles Predict Four-Year Risk of Developing Diabetes, Metabolic Syndrome, Dyslipidemia, and Hypertension in Japanese Population

OpenAIRE

Yamakado, Minoru; Nagao, Kenji; Imaizumi, Akira; Tani, Mizuki; Toda, Akiko; Tanaka, Takayuki; Jinzu, Hiroko; Miyano, Hiroshi; Yamamoto, Hiroshi; Daimon, Takashi; Horimoto, Katsuhisa; Ishizaka, Yuko

2015-01-01

Plasma free amino acid (PFAA) profile is highlighted in its association with visceral obesity and hyperinsulinemia, and future diabetes. Indeed PFAA profiling potentially can evaluate individuals? future risks of developing lifestyle-related diseases, in addition to diabetes. However, few studies have been performed especially in Asian populations, about the optimal combination of PFAAs for evaluating health risks. We quantified PFAA levels in 3,701 Japanese subjects, and determined visceral ...

Investigation of mechanisms for He-I emission radial profile broadening in a weakly ionized cylindrical helium plasma with recombining edge

Energy Technology Data Exchange (ETDEWEB)

Hollmann, E. M.; Brandt, C.; Hudson, B.; Nishijima, D.; Pigarov, A. Yu. [University of California–San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Kumar, D. [Johns Hopkins University, 3400 N Charles St., Baltimore, Maryland 21218 (United States)

2013-09-15

Spatially resolved spectroscopic measurements of He-I line emission are used to study the causes of emission profile broadening radially across the cylinder of a weakly ionized helium plasma. The plasma consists of an ionizing core (r < 2 cm) surrounded by a recombining edge (r > 2 cm) plasma. The brightness profiles of low-n EUV He-I resonance lines are shown to be strongly radially broadened due to opacity. The brightness profiles of high-n visible lines are also found to be strongly radially broadened, but dominantly due to edge recombination. Visible low-n lines are less strongly radially broadened, apparently by a combination of both recombination and EUV opacity. The low-n visible He-I line ratio method with central opacity correction is found to calculate central electron density and temperature well, with poor agreement at the edge, as expected for recombining plasma. In the recombining edge, high-n Boltzmann analysis is found to accurately measure the cold (T{sub e} < 0.2 eV) edge temperature. Near the core, however, high-n Boltzmann analysis can be complicated by electron-impact excitation, giving incorrect (T{sub e}≈ 0.1 eV) apparent temperatures. Probe measurements were not able to capture the cold edge temperature accurately, probably due to large potential fluctuations, even when using fast triple probe measurements. Fast spectroscopic measurements show that this discrepancy is not explained by recombining plasma alternating with ionizing plasma in the edge region.

Interactive network analysis of the plasma amino acids profile in a mouse model of hyperglycemia

OpenAIRE

Tanaka, Takayuki; Mochida, Taiga; Maki, Yukihiro; Shiraki, Yasuko; Mori, Hiroko; Matsumoto, Shirou; Shimbo, Kazutaka; Ando, Toshihiko; Nakamura, Kimitoshi; Endo, Fumio; Okamoto, Masahiro

2013-01-01

Amino acids are a group of metabolites that are important substrates for protein synthesis, are important as signaling molecules and play central roles as highly connected metabolic hubs, and therefore, there are many reports that describe disease-specific abnormalities in plasma amino acids profile. However, the causes of progression from a healthy control to a manifestation of the plasma amino acid changes remain obscure. Here, we extended the plasma amino acids profile to relationships tha...

Effect of plasma distribution on propulsion performance in electrodeless plasma thrusters

Science.gov (United States)

Takao, Yoshinori; Takase, Kazuki; Takahashi, Kazunori

2016-09-01

A helicon plasma thruster consisting of a helicon plasma source and a magnetic nozzle is one of the candidates for long-lifetime thrusters because no electrodes are employed to generate or accelerate plasma. A recent experiment, however, detected the non-negligible axial momentum lost to the lateral wall boundary, which degrades thruster performance, when the source was operated with highly ionized gases. To investigate this mechanism, we have conducted two-dimensional axisymmetric particle-in-cell (PIC) simulations with the neutral distribution obtained by Direct Simulation Monte Carlo (DSMC) method. The numerical results have indicated that the axially asymmetric profiles of the plasma density and potential are obtained when the strong decay of neutrals occurs at the source downstream. This asymmetric potential profile leads to the accelerated ion towards the lateral wall, leading to the non-negligible net axial force in the opposite direction of the thrust. Hence, to reduce this asymmetric profile by increasing the neutral density at downstream and/or by confining plasma with external magnetic field would result in improvement of the propulsion performance. These effects are also analyzed by PIC/DSMC simulations.

Measurements of Electron Temperature and Density Profiles of Plasmas Produced by Nike KrF Laser for Laser Plasma Instability (LPI) Research

Science.gov (United States)

Oh, Jaechul; Weaver, J. L.; Obenschain, S. P.; Schmitt, A. J.; Kehne, D. M.; Karasik, M.; Chan, L.-Y.; Serlin, V.; Phillips, L.

2012-10-01

ExperimentsfootnotetextJ. Oh, et al, GO5.4, APS DPP (2010).^,footnotetextJ. L. Weaver, et al, GO5.3, APS DPP (2010). using Nike KrF laser observed LPI signatures from CH plasmas at the laser intensities above ˜1x10^15 W/cm^2. Knowing spatial profiles of temperature (Te) and density (ne) in the underdense coronal region (0 Nike LPI experiment, a side-on grid imaging refractometer (GIR)footnotetextR. S. Craxton, et al, Phys. Fluids B 5, 4419 (1993). is being deployed for measuring the underdense plasma profiles. The GIR will resolve Te and ne in space taking a 2D snapshot of probe laser (λ= 263 nm, δt = 10 psec) beamlets (50μm spacing) refracted by the plasma at a selected time during the laser illumination. Time-resolved spectrometers with an absolute-intensity-calibrated photodiode array and a streak camera will simultaneously monitor light emission from the plasma in spectral ranges relevant to Raman (SRS) and two plasmon decay (TDP) instabilities. The experimental study of effects of the plasma profiles on the LPI initiation will be presented.

Plasma microRNA profiles in rat models of hepatocellular injury, cholestasis, and steatosis.

Directory of Open Access Journals (Sweden)

Yu Yamaura

Full Text Available MicroRNAs (miRNAs are small RNA molecules that function to modulate the expression of target genes, playing important roles in a wide range of physiological and pathological processes. The miRNAs in body fluids have received considerable attention as potential biomarkers of various diseases. In this study, we compared the changes of the plasma miRNA expressions by acute liver injury (hepatocellular injury or cholestasis and chronic liver injury (steatosis, steatohepatitis and fibrosis using rat models made by the administration of chemicals or special diets. Using miRNA array analysis, we found that the levels of a large number of miRNAs (121-317 miRNAs were increased over 2-fold and the levels of a small number of miRNAs (6-35 miRNAs were decreased below 0.5-fold in all models except in a model of cholestasis caused by bile duct ligation. Interestingly, the expression profiles were different between the models, and the hierarchical clustering analysis discriminated between the acute and chronic liver injuries. In addition, miRNAs whose expressions were typically changed in each type of liver injury could be specified. It is notable that, in acute liver injury models, the plasma level of miR-122, the most abundant miRNA in the liver, was more quickly and dramatically increased than the plasma aminotransferase level, reflecting the extent of hepatocellular injury. This study demonstrated that the plasma miRNA profiles could reflect the types of liver injury (e.g. acute/chronic liver injury or hepatocellular injury/cholestasis/steatosis/steatohepatitis/fibrosis and identified the miRNAs that could be specific and sensitive biomarkers of liver injury.

Plasma density profiles and finite bandwidth effects on electron heating

International Nuclear Information System (INIS)

Spielman, R.B.; Mizuno, K.; DeGroot, J.S.; Bollen, W.M.; Woo, W.

1980-01-01

Intense, p-polarized microwaves are incident on an inhomogeneous plasma in a cylindrical waveguide. Microwaves are mainly absorbed by resonant absorption near the critical surface (where the plasma frequency, ω/sub pe/, equals the microwave frequency, ω/sub o/). The localized plasma waves strongly modify the plasma density. Step-plateau density profiles or a cavity are created depending on the plasma flow speed. Hot electron production is strongly affected by the microwave bandwidth. The hot electron temperature varies as T/sub H/ is proportional to (Δ ω/ω) -0 25 . As the hot electron temperature decreases with increasing driver bandwidth, the hot electron density increases. This increase is such that the heat flux into the overdense region (Q is proportional to eta/sub H/T/sub H/ 3 2 ) is nearly constant

Influence of gender on the correlation between plasma growth hormone profiles and urinary growth hormone excretion

DEFF Research Database (Denmark)

Main, K M; Jansson, C; Skakkebak, N

1997-01-01

A lot of interest has been directed towards the measurement of urinary growth hormone (GH) excretion instead of plasma GH profiles or provocation tests. We investigated the factors influencing the relationship between 24- and 3-hour plasma GH profiles and urinary GH excretion in a cohort of 113...... than spontaneous GH peaks. The difference in cross-reactivities of molecular GH forms in polyclonal assays may have an impact on the correlation between plasma and urinary GH. Thus, the diagnostic value of urinary GH measurement as compared to serum GH profiles needs to be further evaluated....

Anomalous plasma heating induced by modulation of the current-density profile

International Nuclear Information System (INIS)

Lopes Cardozo, N.J.

1985-05-01

The usual plasma heating in a tokamak needs additional heating to reach ignition temperature (approx. 10 8 K). The method used in the TORTUR III experiment is to induce anomalous plasma resistivity by applying a short (10 microseconds) high-voltage pulse. A sharp rise of the plasma temperature is found almost simultaneously, but this effect, though considerable, is too short-lived to be of interest for a thermonuclear chain reaction. A second pulse gives a second rise of temperature, but this time a slow one, extending over several milliseconds. The mechanism of this delayed heating and the reservoir within the plasma supplying the energy are subjects of investigation in the TORTUR III experiments. Some conclusions concerning the plasma heating mechanism are presented. The conclusion is reached that the application of the high-voltage pulse results in a modulation of the current-density profile: the (normally already peaked) profile sharpens, the current concentrates in the centre of the plasma column. This is a non-equilibrium situation. It relaxes to the noraml current distribution within approximately 2 milliseconds. As long as this relaxation process is not finished, the dissipation is on an enhanced level and anomalous plasma heating is observed. Many plasma parameters are surveyed and evaluated: temperature (both of the ions and the electrons), density, emission spectrum (from microwaves to hard X-rays) and the fluctuation spectrum. Main subject of this report is the measurement and interpretation of the X-rays of the emission spectrum. Experimental results are presented and discussed

Potential of an emissive cylindrical probe in plasma.

Science.gov (United States)

Fruchtman, A; Zoler, D; Makrinich, G

2011-08-01

The floating potential of an emissive cylindrical probe in a plasma is calculated for an arbitrary ratio of Debye length to probe radius and for an arbitrary ion composition. In their motion to the probe the ions are assumed to be collisionless. For a small Debye length, a two-scale analysis for the quasineutral plasma and for the sheath provides analytical expressions for the emitted and collected currents and for the potential as functions of a generalized mass ratio. For a Debye length that is not small, it is demonstrated that, as the Debye length becomes larger, the probe potential approaches the plasma potential and that the ion density near the probe is not smaller but rather is larger than it is in the plasma bulk.

Exploratory Study on Plasma Immunomodulator and Antibody Profiles in Tuberculosis Patients

Science.gov (United States)

Ravindran, Resmi; Krishnan, Viswanathan V.; Khanum, Azra; Luciw, Paul A.

2013-01-01

Host immune responses to Mycobacterium tuberculosis are generally able to contain infection and maintain a delicate balance between protection and immunopathology. A shift in this balance appears to underlie active disease observed in about 10% of infected individuals. Effects of local inflammation, combined with anti-M. tuberculosis systemic immune responses, are directly detectable in peripheral circulation, without ex vivo stimulation of blood cells or biopsy of the affected organs. We studied plasma immunomodulator and antibody biomarkers in patients with active pulmonary tuberculosis (TB) by a combination of multiplex microbead immunoassays and computational tools for data analysis. Plasma profiles of 10 immunomodulators and antibodies against eight M. tuberculosis antigens (previously reported by us) were examined in active pulmonary TB patients in a country where TB is endemic, Pakistan. Multiplex analyses were performed on samples from apparently healthy individuals without active TB from the same community as the TB patients to establish the assay baselines for all analytes. Over 3,000 data points were collected from patients (n = 135) and controls (n = 37). The data were analyzed by multivariate and computer-assisted cluster analyses to reveal patterns of plasma immunomodulators and antibodies. This study shows plasma profiles that in most patients represented either strong antibody or strong immunomodulator biomarkers. Profiling of a combination of both immunomodulators and antibodies described here may be valuable for the analysis of host immune responses in active TB in countries where the disease is endemic. PMID:23761664

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

International Nuclear Information System (INIS)

Jelic, N.

2011-01-01

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

Metabolomic Profiling of Plasma from Melioidosis Patients Using UHPLC-QTOF MS Reveals Novel Biomarkers for Diagnosis

Directory of Open Access Journals (Sweden)

Susanna K. P. Lau

2016-02-01

Full Text Available To identify potential biomarkers for improving diagnosis of melioidosis, we compared plasma metabolome profiles of melioidosis patients compared to patients with other bacteremia and controls without active infection, using ultra-high-performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry. Principal component analysis (PCA showed that the metabolomic profiles of melioidosis patients are distinguishable from bacteremia patients and controls. Using multivariate and univariate analysis, 12 significant metabolites from four lipid classes, acylcarnitine (n = 6, lysophosphatidylethanolamine (LysoPE (n = 3, sphingomyelins (SM (n = 2 and phosphatidylcholine (PC (n = 1, with significantly higher levels in melioidosis patients than bacteremia patients and controls, were identified. Ten of the 12 metabolites showed area-under-receiver operating characteristic curve (AUC >0.80 when compared both between melioidosis and bacteremia patients, and between melioidosis patients and controls. SM(d18:2/16:0 possessed the largest AUC when compared, both between melioidosis and bacteremia patients (AUC 0.998, sensitivity 100% and specificity 91.7%, and between melioidosis patients and controls (AUC 1.000, sensitivity 96.7% and specificity 100%. Our results indicate that metabolome profiling might serve as a promising approach for diagnosis of melioidosis using patient plasma, with SM(d18:2/16:0 representing a potential biomarker. Since the 12 metabolites were related to various pathways for energy and lipid metabolism, further studies may reveal their possible role in the pathogenesis and host response in melioidosis.

Metabolomic Profiling of Plasma from Melioidosis Patients Using UHPLC-QTOF MS Reveals Novel Biomarkers for Diagnosis.

Science.gov (United States)

Lau, Susanna K P; Lee, Kim-Chung; Lo, George C S; Ding, Vanessa S Y; Chow, Wang-Ngai; Ke, Tony Y H; Curreem, Shirly O T; To, Kelvin K W; Ho, Deborah T Y; Sridhar, Siddharth; Wong, Sally C Y; Chan, Jasper F W; Hung, Ivan F N; Sze, Kong-Hung; Lam, Ching-Wan; Yuen, Kwok-Yung; Woo, Patrick C Y

2016-02-27

To identify potential biomarkers for improving diagnosis of melioidosis, we compared plasma metabolome profiles of melioidosis patients compared to patients with other bacteremia and controls without active infection, using ultra-high-performance liquid chromatography-electrospray ionization-quadruple time-of-flight mass spectrometry. Principal component analysis (PCA) showed that the metabolomic profiles of melioidosis patients are distinguishable from bacteremia patients and controls. Using multivariate and univariate analysis, 12 significant metabolites from four lipid classes, acylcarnitine (n = 6), lysophosphatidylethanolamine (LysoPE) (n = 3), sphingomyelins (SM) (n = 2) and phosphatidylcholine (PC) (n = 1), with significantly higher levels in melioidosis patients than bacteremia patients and controls, were identified. Ten of the 12 metabolites showed area-under-receiver operating characteristic curve (AUC) >0.80 when compared both between melioidosis and bacteremia patients, and between melioidosis patients and controls. SM(d18:2/16:0) possessed the largest AUC when compared, both between melioidosis and bacteremia patients (AUC 0.998, sensitivity 100% and specificity 91.7%), and between melioidosis patients and controls (AUC 1.000, sensitivity 96.7% and specificity 100%). Our results indicate that metabolome profiling might serve as a promising approach for diagnosis of melioidosis using patient plasma, with SM(d18:2/16:0) representing a potential biomarker. Since the 12 metabolites were related to various pathways for energy and lipid metabolism, further studies may reveal their possible role in the pathogenesis and host response in melioidosis.

The significance and robustness of a plasma free amino acid (PFAA) profile-based multiplex function for detecting lung cancer

International Nuclear Information System (INIS)

Shingyoji, Masato; Mitsushima, Toru; Yamakado, Minoru; Kimura, Hideki; Iizasa, Toshihiko; Higashiyama, Masahiko; Imamura, Fumio; Saruki, Nobuhiro; Imaizumi, Akira; Yamamoto, Hiroshi; Daimon, Takashi; Tochikubo, Osamu

2013-01-01

We have recently reported on the changes in plasma free amino acid (PFAA) profiles in lung cancer patients and the efficacy of a PFAA-based, multivariate discrimination index for the early detection of lung cancer. In this study, we aimed to verify the usefulness and robustness of PFAA profiling for detecting lung cancer using new test samples. Plasma samples were collected from 171 lung cancer patients and 3849 controls without apparent cancer. PFAA levels were measured by high-performance liquid chromatography (HPLC)–electrospray ionization (ESI)–mass spectrometry (MS). High reproducibility was observed for both the change in the PFAA profiles in the lung cancer patients and the discriminating performance for lung cancer patients compared to previously reported results. Furthermore, multivariate discriminating functions obtained in previous studies clearly distinguished the lung cancer patients from the controls based on the area under the receiver-operator characteristics curve (AUC of ROC = 0.731 ~ 0.806), strongly suggesting the robustness of the methodology for clinical use. Moreover, the results suggested that the combinatorial use of this classifier and tumor markers improves the clinical performance of tumor markers. These findings suggest that PFAA profiling, which involves a relatively simple plasma assay and imposes a low physical burden on subjects, has great potential for improving early detection of lung cancer

Altered gene-expression profile in rat plasma and promoted body ...

African Journals Online (AJOL)

Altered gene-expression profile in rat plasma and promoted body and brain development ... The study was aimed to explore how the prenatal EE impacts affect the ... positively promote the body and nervous system development of offspring, ...

Influence of an axial magnetic field on the density profile of capillary plasma channels

CERN Document Server

Ivanov, V V; Toma, E S; Bijkerk, F

2003-01-01

A narrow capillary plasma channel, with a sizeable depletion of the electron density on the channel axis, has been proposed to guide a laser pulse over a length of several to several tens of centimetres. We discuss the possibility to significantly improve the wave-guiding properties of such a channel by applying an axial magnetic field. Our analytical and numerical studies show that a pulsed axial magnetic field of 10 T in a hydrogen capillary plasma at a pressure of 50 Torr will reduce the on-axis plasma density by a factor of three, and the full width at half maximum of the density profile by a factor of two. The resulting parabolic plasma density profile is expected to be more efficient in guiding laser pulses.

Lyapunov-based distributed control of the safety-factor profile in a tokamak plasma

International Nuclear Information System (INIS)

Bribiesca Argomedo, Federico; Witrant, Emmanuel; Prieur, Christophe; Brémond, Sylvain; Nouailletas, Rémy; Artaud, Jean-François

2013-01-01

A real-time model-based controller is developed for the tracking of the distributed safety-factor profile in a tokamak plasma. Using relevant physical models and simplifying assumptions, theoretical stability and robustness guarantees were obtained using a Lyapunov function. This approach considers the couplings between the poloidal flux diffusion equation, the time-varying temperature profiles and an independent total plasma current control. The actuator chosen for the safety-factor profile tracking is the lower hybrid current drive, although the results presented can be easily extended to any non-inductive current source. The performance and robustness of the proposed control law is evaluated with a physics-oriented simulation code on Tore Supra experimental test cases. (paper)

Promising Metabolite Profiles in the Plasma and CSF of Early Clinical Parkinson's Disease

Directory of Open Access Journals (Sweden)

Daniel Stoessel

2018-03-01

Full Text Available Parkinson's disease (PD shows high heterogeneity with regard to the underlying molecular pathogenesis involving multiple pathways and mechanisms. Diagnosis is still challenging and rests entirely on clinical features. Thus, there is an urgent need for robust diagnostic biofluid markers. Untargeted metabolomics allows establishing low-molecular compound biomarkers in a wide range of complex diseases by the measurement of various molecular classes in biofluids such as blood plasma, serum, and cerebrospinal fluid (CSF. Here, we applied untargeted high-resolution mass spectrometry to determine plasma and CSF metabolite profiles. We semiquantitatively determined small-molecule levels (≤1.5 kDa in the plasma and CSF from early PD patients (disease duration 0–4 years; n = 80 and 40, respectively, and sex- and age-matched controls (n = 76 and 38, respectively. We performed statistical analyses utilizing partial least square and random forest analysis with a 70/30 training and testing split approach, leading to the identification of 20 promising plasma and 14 CSF metabolites. These metabolites differentiated the test set with an AUC of 0.8 (plasma and 0.9 (CSF. Characteristics of the metabolites indicate perturbations in the glycerophospholipid, sphingolipid, and amino acid metabolism in PD, which underscores the high power of metabolomic approaches. Further studies will enable to develop a potential metabolite-based biomarker panel specific for PD.

A gestational profile of placental exosomes in maternal plasma and their effects on endothelial cell migration.

Directory of Open Access Journals (Sweden)

Carlos Salomon

Full Text Available Studies completed to date provide persuasive evidence that placental cell-derived exosomes play a significant role in intercellular communication pathways that potentially contribute to placentation and development of materno-fetal vascular circulation. The aim of this study was to establish the gestational-age release profile and bioactivity of placental cell-derived exosome in maternal plasma. Plasma samples (n = 20 per pregnant group were obtained from non-pregnant and pregnant women in the first (FT, 6-12 weeks, second (ST, 22-24 weeks and third (TT, 32-38 weeks trimester. The number of exosomes and placental exosome contribution were determined by quantifying immunoreactive exosomal CD63 and placenta-specific marker (PLAP, respectively. The effect of exosomes isolated from FT, ST and TT on endothelial cell migration were established using a real-time, live-cell imaging system (Incucyte. Exosome plasma concentration was more than 50-fold greater in pregnant women than in non-pregnant women (p<0.001. During normal healthy pregnancy, the number of exosomes present in maternal plasma increased significantly with gestational age by more that two-fold (p<0.001. Exosomes isolated from FT, ST and TT increased endothelial cell migration by 1.9±0.1, 1.6±0.2 and 1.3±0.1-fold, respectively compared to the control. Pregnancy is associated with a dramatic increase in the number of exosomes present in plasma and maternal plasma exosomes are bioactive. While the role of placental cell-derived exosome in regulating maternal and/or fetal vascular responses remains to be elucidated, changes in exosome profile may be of clinical utility in the diagnosis of placental dysfunction.

Recent measurements of electron density profiles of plasmas in PLADIS I, a plasma disruption simulator

International Nuclear Information System (INIS)

Bradley, J. III; Sharp, G.; Gahl, J.M. Kuznetsov, V.; Rockett, P.; Hunter, J.

1995-01-01

Tokamak disruption simulation experiments are being conducted at the University of New Mexico (UNM) using the PLADIS I plasma gun system. PLADIS I is a high power, high energy coaxial plasma gun configured to produce an intense plasma beam. First wall candidate materials are placed in the beam path to determine their response under disruption relevant energy densities. An optically thick vapor shield plasma has been observed to form above the target surface in PLADIS I. Various diagnostics have been used to determine the characteristics of the incident plasma and the vapor shielding plasma. The cross sectional area of the incident plasma beam is a critical characteristic, as it is used in the calculation of the incident plasma energy density. Recently, a HeNe interferometer in the Mach-Zehnder configuration has been constructed and used to probe the electron density of the incident plasma beam and vapor shield plasma. The object beam of the interferometer is scanned across the plasma beam on successive shots, yielding line integrals of beam density on different chords through the plasma. Data from the interferometer is used to determine the electron density profile of the incident plasma beam as a function of beam radius. This data is then used to calculate the effective beam area. Estimates. of beam area, obtained from other diagnostics such as damage targets, calorimeter arrays and off-axis measurements of surface pressure, will be compared with data from the interferometer to obtain a better estimate of the beam cross sectional area

Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

Science.gov (United States)

Zanáška, M.; Adámek, J.; Peterka, M.; Kudrna, P.; Tichý, M.

2015-03-01

The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents Isat-/Isat+ to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.

Plasma metabolic profiling of dairy cows affected with clinical ketosis using LC/MS technology.

Science.gov (United States)

Li, Y; Xu, C; Xia, C; Zhang, Hy; Sun, Lw; Gao, Y

2014-01-01

Ketosis in dairy cattle is an important metabolic disorder. Currently, the plasma metabolic profile of ketosis as determined using liquid chromatography-mass spectrometry (LC/MS) has not been reported. To investigate plasma metabolic profiles from cows with clinical ketosis in comparison to control cows. Twenty Holstein dairy cows were divided into two groups based on clinical signs and plasma β-hydroxybutyric acid and glucose concentrations 7-21 days postpartum: clinical ketosis and control cows. Plasma metabolic profiles were analyzed using LC/MS. Data were processed using principal component analysis and orthogonal partial least-squares discriminant analysis. Compared to control cows, the levels of valine, glycine, glycocholic, tetradecenoic acid, and palmitoleic acid increased significantly in clinical ketosis. On the other hand, the levels of arginine, aminobutyric acid, leucine/isoleucine, tryptophan, creatinine, lysine, norcotinine, and undecanoic acid decreased markedly. Our results showed that the metabolic changes in cows with clinical ketosis involve complex metabolic networks and signal transduction. These results are important for future studies elucidating the pathogenesis, diagnosis, and prevention of clinical ketosis in dairy cows.

Asymmetry of Hβ Stark profiles in T-tube hydrogen plasma

International Nuclear Information System (INIS)

Djurovic, S.; Nikolic, D.; Savic, I.; Soerge, S.; Demura, A. V.

2005-01-01

The whole Balmer H β line profiles are studied in detail experimentally in the T-tube discharge for the wide range of plasma parameters. Besides the common one, two additional parameters are introduced to characterize the asymmetry behavior of the experimental Stark profiles with the reference point chosen in the center of the line. The experimental data are analyzed and benchmarked versus the simple theoretical model based on the effects of microfield nonuniformity and electron impact shifts

On the relation between plasma and neutral gas profiles in a cold gas-blanket system

International Nuclear Information System (INIS)

Bures, M.

1981-01-01

A solution for the neutral density profile using the measured plasma density and temperature gradients is presented. The fluid model is used. It is found that the penetration length for neutrals is underestimated in the situation where the integrated profiles are used. The ionization rate need not be inferred in the present calculation, because the ionization of neutrals diffusing into the plasma is implicitly included in measured profiles. This calculation is advantageous in the low temperature range where the ionization rate is a strongly varying function of temperature. Finally the presented solution indicates that the temperature gradient plays the essential role in the determination of the neutral density profile. (Auth.)

Human Plasma Metabolomics Study across All Stages of Age-Related Macular Degeneration Identifies Potential Lipid Biomarkers.

Science.gov (United States)

Laíns, Inês; Kelly, Rachel S; Miller, John B; Silva, Rufino; Vavvas, Demetrios G; Kim, Ivana K; Murta, Joaquim N; Lasky-Su, Jessica; Miller, Joan W; Husain, Deeba

2018-02-01

To characterize the plasma metabolomic profile of patients with age-related macular degeneration (AMD) using mass spectrometry (MS). Cross-sectional observational study. We prospectively recruited participants with a diagnosis of AMD and a control group (>50 years of age) without any vitreoretinal disease. All participants underwent color fundus photography, used for AMD diagnosis and staging, according to the Age-Related Eye Disease Study classification scheme. Fasting blood samples were collected and plasma was analyzed by Metabolon, Inc. (Durham, NC), using ultrahigh-performance liquid chromatography (UPLC) and high-resolution MS. Metabolon's hardware and software were used to identify peaks and control quality. Principal component analysis and multivariate regression were performed to assess differences in the metabolomic profiles of AMD patients versus controls, while controlling for potential confounders. For biological interpretation, pathway enrichment analysis of significant metabolites was performed using MetaboAnalyst. The primary outcome measures were levels of plasma metabolites in participants with AMD compared with controls and among different AMD severity stages. We included 90 participants with AMD (30 with early AMD, 30 with intermediate AMD, and 30 with late AMD) and 30 controls. Using UPLC and MS, 878 biochemicals were identified. Multivariate logistic regression identified 87 metabolites with levels that differed significantly between AMD patients and controls. Most of these metabolites (82.8%; n = 72), including the most significant metabolites, belonged to the lipid pathways. Analysis of variance revealed that of the 87 metabolites, 48 (55.2%) also were significantly different across the different stages of AMD. A significant enrichment of the glycerophospholipids pathway was identified (P = 4.7 × 10 -9 ) among these metabolites. Participants with AMD have altered plasma metabolomic profiles compared with controls. Our data suggest

Measurements of electron density and temperature profiles in plasma produced by Nike KrF laser for laser plasma instability research

Science.gov (United States)

Oh, Jaechul; Weaver, J. L.; Karasik, M.; Chan, L. Y.

2015-08-01

A grid image refractometer (GIR) has been implemented at the Nike krypton fluoride laser facility of the Naval Research Laboratory. This instrument simultaneously measures propagation angles and transmissions of UV probe rays (λ = 263 nm, Δt = 10 ps) refracted through plasma. We report results of the first Nike-GIR measurement on a CH plasma produced by the Nike laser pulse (˜1 ns FWHM) with the intensity of 1.1 × 1015 W/cm2. The measured angles and transmissions were processed to construct spatial profiles of electron density (ne) and temperature (Te) in the underdense coronal region of the plasma. Using an inversion algorithm developed for the strongly refracted rays, the deployed GIR system probed electron densities up to 4 × 1021 cm-3 with the density scale length of 120 μm along the plasma symmetry axis. The resulting ne and Te profiles are verified to be self-consistent with the measured quantities of the refracted probe light.

Boron Profile Sharpening in Ultra-Shallow p+-n Junction Produced by Plasma Immersion Ion Implantation from BF3 Plasma

International Nuclear Information System (INIS)

Lukichev, V.; Rudenko, K.; Orlikovsky, A.; Pustovit, A.; Vyatkin, A.

2008-01-01

We have investigated plasma immersion ion implantation (PI 3 ) of boron with energies of 500 eV (doses up to 2x10 15 cm -2 ) from BF 3 plasma with He pre-amorphizing implantation (PAI)(energy 3 keV, dose 5x10 16 cm -2 ). Implanted samples were subjected to RTA (T = 900 to 1050 deg. C, t = 2 to 24 sec and spike anneal). SIMS analysis of boron profiles revealed its anomalous behavior. For short RTA times the profile tail (below 5x10 19 cm -3 ) moves toward the surface and then, as in the usual diffusion, toward the bulk at longer annealing times.

Potential formation in a one-dimensional bounded plasma system containing a two-electron temperature plasma: Kinetic model and PIC simulation

International Nuclear Information System (INIS)

Gyergyek, T.; Jurcic-Zlobec, B.; Cercek, M.

2008-01-01

Potential formation in a bounded plasma system that contains electrons with a two-temperature velocity distribution and is terminated by a floating, electron emitting electrode (collector) is studied by a one-dimensional kinetic model. A method on how to determine the boundary conditions at the collector for the numerical solution of the Poisson equation is presented. The difference between the regular and the irregular numerical solutions of the Poisson equation is explained. The regular numerical solution of the Poisson equation fulfills the boundary conditions at the source and can be computed for any distance from the collector. The irregular solution does not fulfill the source boundary conditions and the computation breaks down at some distance from the collector. An excellent agreement of the values of the potential at the inflection point found from the numerical solution of the Poisson equation with the values predicted by the analytical model is obtained. Potential, electric field, and particle density profiles found by the numerical solution of the Poisson equation are compared to the profiles obtained with the particle in cell computer simulation. A very good quantitative agreement of the potential and electric field profiles is obtained. For certain values of the parameters the analytical model predicts three possible values of the potential at the inflection point. In such cases always only one of the corresponding numerical solutions of the Poisson equation is regular, while the other two are irregular. The regular numerical solution of the Poisson equation always corresponds to the solution of the model that predicts the largest ion flux to the collector

Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

International Nuclear Information System (INIS)

Zanáška, M.; Kudrna, P.; Tichý, M.; Adámek, J.; Peterka, M.

2015-01-01

The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents I sat − /I sat + to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa

Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

Energy Technology Data Exchange (ETDEWEB)

Zanáška, M.; Kudrna, P.; Tichý, M. [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 12116 Prague 2 (Czech Republic); Adámek, J. [Institute of Plasma Physics AS CR, v.v.i., Za Slovankou 3, 18200 Prague 8 (Czech Republic); Peterka, M. [Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 12116 Prague 2 (Czech Republic); Institute of Plasma Physics AS CR, v.v.i., Za Slovankou 3, 18200 Prague 8 (Czech Republic)

2015-03-15

The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents I{sub sat}{sup −}/I{sub sat}{sup +} to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.

Numerical and Experimental Investigation of Turbulent Transport Control via Shaping of Radial Plasma Flow Profiles

International Nuclear Information System (INIS)

Gilmore, Mark Allen

2017-01-01

Turbulence, and turbulence-driven transport are ubiquitous in magnetically confined plasmas, where there is an intimate relationship between turbulence, transport, instability driving mechanisms (such as gradients), plasma flows, and flow shear. Though many of the detailed physics of the interrelationship between turbulence, transport, drive mechanisms, and flow remain unclear, there have been many demonstrations that transport and/or turbulence can be suppressed or reduced via manipulations of plasma flow profiles. This is well known in magnetic fusion plasmas [e.g., high confinement mode (H-mode) and internal transport barriers (ITB's)], and has also been demonstrated in laboratory plasmas. However, it may be that the levels of particle transport obtained in such cases [e.g. H-mode, ITB's] are actually lower than is desirable for a practical fusion device. Ideally, one would be able to actively feedback control the turbulent transport, via manipulation of the flow profiles. The purpose of this research was to investigate the feasibility of using both advanced model-based control algorithms, as well as non-model-based algorithms, to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles. The University of New Mexico was responsible for the experimental portion of the project, while our collaborators at the University of Montana provided plasma transport modeling, and collaborators at Lehigh University developed and explored control methods.

Numerical and Experimental Investigation of Turbulent Transport Control via Shaping of Radial Plasma Flow Profiles

Energy Technology Data Exchange (ETDEWEB)

Gilmore, Mark Allen [Univ. of New Mexico, Albuquerque, NM (United States)

2017-02-05

Turbulence, and turbulence-driven transport are ubiquitous in magnetically confined plasmas, where there is an intimate relationship between turbulence, transport, instability driving mechanisms (such as gradients), plasma flows, and flow shear. Though many of the detailed physics of the interrelationship between turbulence, transport, drive mechanisms, and flow remain unclear, there have been many demonstrations that transport and/or turbulence can be suppressed or reduced via manipulations of plasma flow profiles. This is well known in magnetic fusion plasmas [e.g., high confinement mode (H-mode) and internal transport barriers (ITB’s)], and has also been demonstrated in laboratory plasmas. However, it may be that the levels of particle transport obtained in such cases [e.g. H-mode, ITB’s] are actually lower than is desirable for a practical fusion device. Ideally, one would be able to actively feedback control the turbulent transport, via manipulation of the flow profiles. The purpose of this research was to investigate the feasibility of using both advanced model-based control algorithms, as well as non-model-based algorithms, to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles. The University of New Mexico was responsible for the experimental portion of the project, while our collaborators at the University of Montana provided plasma transport modeling, and collaborators at Lehigh University developed and explored control methods.

Potential of accuracy profile for method validation in inductively coupled plasma spectrochemistry

International Nuclear Information System (INIS)

Mermet, J.M.; Granier, G.

2012-01-01

Method validation is usually performed over a range of concentrations for which analytical criteria must be verified. One important criterion in quantitative analysis is accuracy, i.e. the contribution of both trueness and precision. The study of accuracy over this range is called an accuracy profile and provides experimental tolerance intervals. Comparison with acceptability limits fixed by the end user defines a validity domain. This work describes the computation involved in the building of the tolerance intervals, particularly for the intermediate precision with within-laboratory experiments and for the reproducibility with interlaboratory studies. Computation is based on ISO 5725‐4 and on previously published work. Moreover, the bias uncertainty is also computed to verify the bias contribution to accuracy. The various types of accuracy profile behavior are exemplified with results obtained by using ICP-MS and ICP-AES. This procedure allows the analyst to define unambiguously a validity domain for a given accuracy. However, because the experiments are time-consuming, the accuracy profile method is mainly dedicated to method validation. - Highlights: ► An analytical method is defined by its accuracy, i.e. both trueness and precision. ► The accuracy as a function of an analyte concentration is an accuracy profile. ► Profile basic concepts are explained for trueness and intermediate precision. ► Profile-based tolerance intervals have to be compared with acceptability limits. ► Typical accuracy profiles are given for both ICP-AES and ICP-MS techniques.

Plasma metabolic profiling analysis of toxicity induced by brodifacoum using metabonomics coupled with multivariate data analysis.

Science.gov (United States)

Yan, Hui; Qiao, Zheng; Shen, Baohua; Xiang, Ping; Shen, Min

2016-10-01

Brodifacoum is one of the most widely used rodenticides for rodent control and eradication; however, human and animal poisoning due to primary and secondary exposure has been reported since its development. Although numerous studies have described brodifacoum induced toxicity, the precise mechanism still needs to be explored. Gas chromatography mass spectrometry (GC-MS) coupled with an ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was applied to characterize the metabolic profile of brodifacoum induced toxicity and discover potential biomarkers in rat plasma. The toxicity of brodifacoum was dose-dependent, and the high-dose group obviously manifested toxicity with subcutaneous hemorrhage. The blood brodifacoum concentration showed a positive relation to the ingestion dose in toxicological analysis. Significant changes of twenty-four metabolites were identified and considered as potential toxicity biomarkers, primarily involving glucose metabolism, lipid metabolism and amino acid metabolism associated with anticoagulant activity, nephrotoxicity and hepatic damage. MS-based metabonomics analysis in plasma samples is helpful to search for potential poisoning biomarkers and to understand the underlying mechanisms of brodifacoum induced toxicity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Radial plasma profile and neutron yield in an adiabatic trap with fast atom injection

International Nuclear Information System (INIS)

Panov, D.A.

1988-01-01

Radial profiles of ion densities depending on two dimensionless parameters, which values are determined by the trap, plasma and injected beam parameters are found in dimensionless units for a plasma generated by fast atom injection in an adiabatic trap. The calculated profiles are used for determining the neutron yield. Simple approximated dimensional relations permitting to estimate quickly neutron yield, required injection power, flux of charge exchange atoms on the wall around the plasma in a wide energy range of injected atoms, trap field modulud, injection angle, trap radius and length are determined. The energetic efficiency of neutron production is estimated and it is shown that it grows with the injection energy. 7 refs.; 7 figs

Measurements of plasma rotation in an axially magnetized MPD arc-jet

Energy Technology Data Exchange (ETDEWEB)

Tobari, Hiroyuki; Ashino, Masashi; Yoshino, Kyohei; Sagi, Yukiko; Yoshinuma, Mikirou; Hattori, Kunihiko; Ando, Akira; Inutake, Masaaki [Department of Electrical Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi (Japan)

2001-01-24

Characteristics of an axially magnetized MPD (magneto-plasma-dynamic) arcjet plasma are investigated by spectroscopy on the HITOP (High density of Tohoku Plasma) device in Tohoku University. Plasma flow and rotational velocity and temperature of He ion and atom near the muzzle region of MPD arcjet are measured by Doppler shift and broadening of the HeI ({lambda}=578.56 nm) and HeII ({lambda}=468.58 nm) lines. From the measured radial profile of rotational velocity and temperature of He ion, the radial profiles of electrical field and space potential are calculated and it has been found that the potential profile in the core region is parabolic, which shows the plasma rotates as a rigid body. (author)

GPU based 3D feature profile simulation of high-aspect ratio contact hole etch process under fluorocarbon plasmas

Science.gov (United States)

Chun, Poo-Reum; Lee, Se-Ah; Yook, Yeong-Geun; Choi, Kwang-Sung; Cho, Deog-Geun; Yu, Dong-Hun; Chang, Won-Seok; Kwon, Deuk-Chul; Im, Yeon-Ho

2013-09-01

Although plasma etch profile simulation has been attracted much interest for developing reliable plasma etching, there still exist big gaps between current research status and predictable modeling due to the inherent complexity of plasma process. As an effort to address this issue, we present 3D feature profile simulation coupled with well-defined plasma-surface kinetic model for silicon dioxide etching process under fluorocarbon plasmas. To capture the realistic plasma surface reaction behaviors, a polymer layer based surface kinetic model was proposed to consider the simultaneous polymer deposition and oxide etching. Finally, the realistic plasma surface model was used for calculation of speed function for 3D topology simulation, which consists of multiple level set based moving algorithm, and ballistic transport module. In addition, the time consumable computations in the ballistic transport calculation were improved drastically by GPU based numerical computation, leading to the real time computation. Finally, we demonstrated that the surface kinetic model could be coupled successfully for 3D etch profile simulations in high-aspect ratio contact hole plasma etching.

Effect of asymmetric plasma potential in the SOL on the particle radial transport and heat flux broadening

International Nuclear Information System (INIS)

Hara, Junichiro; Uesugi, Yoshihiko; Miura, Yukitoshi; Kawashima, Hisato.

1997-01-01

The effective divertor heat-load relaxation using ExB induced convective cells in the SOL is studied. The ExB convective cells in the SOL are generated by the toroidally asymmetric divertor biasing, which can control the local plasma potential in the SOL. The preliminary experiment has been done in the JFT-2M tokamak with poloidal divertor. The helical SOL current flows along the magnetic field between the locally biased inboard plate and grounded outer plates, thereby modifying plasma potential in the vicinity of the local divertor current flow. The generation of the poloidal electric field reaching up to 1.5kV/m locally in the SOL and the modification of the heat flux profile on the divertor plate is observed. (author)

ICRF-enhanced plasma potentials in the SOL of Alcator C-Mod

Energy Technology Data Exchange (ETDEWEB)

Ochoukov, R.; Whyte, D. G.; Brunner, D.; LaBombard, B.; Lipschultz, B.; Terry, J. L.; Wukitch, S. J. [PSFC MIT, NW17, 175 Albany Street, Cambridge, MA 02139 (United States); D' Ippolito, D. A.; Myra, J. R. [Lodestar Research Corporation, 2400 Central Avenue, Boulder, Colorado 80301 (United States)

2014-02-12

We performed an extensive survey of the plasma potential in the scrape-off layer (SOL) of Ion Cyclotron Range-of Frequencies (ICRF)-heated discharges on Alcator C-Mod. Our results show that plasma potentials are enhanced in the presence of ICRF power and plasma potential values of >100 V are often observed. Such potentials are high enough to induce sputtering of high-Z molybdenum (Mo) plasma facing components by deuterium ions on C-Mod. For comparison, the plasma potential in Ohmic discharges is typically less than 10 V, well below the threshold needed to induce Mo sputtering by deuterium ions. ICRF-enhanced plasma potentials are observed in the SOL regions that both magnetically map and do not map to active ICRF antennas. Regions that magnetically map to active ICRF antennas are accessible to slow waves directly launched by the antennas and these regions experience plasma potential enhancement that is partially consistent with the slow wave rectification mechanism. One of the most defining features of the slow wave rectification is a threshold appearance of significant plasma potentials (>100 V) when the dimensionless rectification parameter Λ{sub −o} is above unity and this trend is observed experimentally. We also observe ICRF-enhanced plasma potentials >100 V in regions that do not magnetically map to the active antennas and, hence, are not accessible for slow waves launched directly by the active antennas. However, unabsorbed fast waves can reach these regions. The general trend that we observe in these 'un-mapped' regions is that the plasma potential scales with the strength of the local RF wave fields with the fast wave polarization and the highest plasma potentials are observed in discharges with the highest levels of unabsorbed ICRF power. Similarly, we find that core Mo levels scale with the level of unabsorbed ICRF power suggesting a link between plasma potentials in the SOL and the strength of the impurity source.

Langmuir probe evaluation of the plasma potential in tokamak edge plasma for non-Maxwellian EEDF

Energy Technology Data Exchange (ETDEWEB)

Popov, Ts.K. [Faculty of Physics, St. Kliment Ohridski University (Bulgaria); Dimitrova, M. [Institute of Plasma Physics, Academy of Sciences of the Czech Republic v.v.i., Prague (Czech Republic); Institute of Electronics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Ivanova, P. [Institute of Electronics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Hasan, E. [Faculty of Physics, St. Kliment Ohridski University (Bulgaria); Institute of Electronics, Bulgarian Academy of Sciences, Sofia (Bulgaria); Horacek, J.; Dejarnac, R.; Stoeckel, J.; Weinzettl, V. [Institute of Plasma Physics, Academy of Sciences of the Czech Republic v.v.i., Prague (Czech Republic); Kovacic, J. [Jozef Stefan Institute, Ljubljana (Slovenia)

2014-04-15

The First derivative probe technique for a correct evaluation of the plasma potential in the case of non-Maxwellian EEDF is presented and used to process experimental data from COMPASS tokamak. Results obtained from classical and first derivative techniques are compared and discussed. The first derivative probe technique provides values for the plasma potential in the scrape-off layer of tokamak plasmas with an accuracy of about ±10%. Classical probe technique can provide values of the plasma potential only, if the electron and ion temperatures are known as well as the coefficient of secondary electron emission. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Data for iTRAQ profiling of micro-vesicular plasma specimens: In search of potential prognostic circulatory biomarkers for Lacunar infarction

Directory of Open Access Journals (Sweden)

Arnab Datta

2015-09-01

Full Text Available To discover potential prognostic biomarkers of Lacunar infarction (LACI, here we present quantitative proteomics data of plasma microvesicle-enriched fraction derived by comparative isobaric profiling of three groups of prospectively followed-up LACI patients (LACI – no adverse outcome, LACI –recurrent vascular event and LACI – cognitive decline and a demographically matched control group. We confidently (unused prot score >3, FDR=1.1% identified 183 proteins, 43 out of which were significantly regulated (p-value<0.05 in at least one of the three LACI groups in comparison to control group. Bioinformatics analysis and data mining revealed upregulation of brain-specific proteins including myelin basic protein, proteins of coagulation cascade (e.g., fibrinogen alpha chain, fibrinogen beta chain and focal adhesion (e.g., integrin alpha-IIb, talin-1, and filamin-A while albumin was downregulated in both groups of patients with adverse outcome. The data of this study are also in line with our previously published article entitled “Discovery of prognostic biomarker candidates of Lacunar infarction by quantitative proteomics of microvesicles enriched plasma” by Datta et al. (2014. The raw data had been deposited to the ProteomeXchange consortium with identifier PXD000748.

Oscillatory wake potential with exchange-correlation in plasmas

Science.gov (United States)

Khan, Arroj A.; Zeba, I.; Jamil, M.; Asif, M.

2017-12-01

The oscillatory wake potential of a moving test charge is studied in quantum dusty plasmas. The plasma system consisting of electrons, ions and negatively charged dust species is embedded in an ambient magnetic field. The modified equation of dispersion is derived using a Quantum Hydrodynamic Model for magnetized plasmas. The quantum effects are inculcated through Fermi degenerate pressure, the tunneling effect and exchange-correlation effects. The study of oscillatory wake is important to know the existence of silence zones in space and astrophysical objects as well as for crystal formation. The graphical description of the potential depicts the significance of the exchange and correlation effects arising through spin and other variables on the wake potential.

Temperature profiles of time dependent tokamak plasmas from the parallel Ohm's law

International Nuclear Information System (INIS)

Micozzi, P.; Roccella, M.

1993-01-01

Profile consistency based on the parallel component of Ohm's law has been used to obtain electron temperature profiles. A resistive neoclassical term and a term that accounts for the bootstrap current contributions have been considered in Ohm's law. A numerical code has been developed to find solutions according to the MHD equilibrium equations. For stationary plasmas, the temperature profiles, obtained by a procedure in which a pseudo-parabolic shape of (J φ /R) is assumed and the peak temperature known from experiments is used, are close to the experimental data for several very different machines (JET, TFTR, ASDEX, ALCATOR-C and FT). The main feature of the model is its capability to provide an easy parametrization of Ohm's law also in non-stationary cases, without going through the complication of a detailed solution of the magnetic field diffusion equation. A rule for estimating a maximum value of the current diffusion time inside the plasma volume in such situations is given. This rule accounts for both the temperature profiles and the stabilization times in some non-stationary pulses observed in JET. (author). 28 refs, 12 figs

Plasma source ion implantation

International Nuclear Information System (INIS)

Conrad, J.R.; Forest, C.

1986-01-01

The authors' technique allows the ion implantation to be performed directly within the ion source at higher currents without ion beam extraction and transport. The potential benefits include greatly increased production rates (factors of 10-1000) and the ability to implant non-planar targets without rastering or shadowing. The technique eliminates the ion extractor grid set, beam raster equipment, drift space and target manipulator equipment. The target to be implanted is placed directly within the plasma source and is biased to a large negative potential so that plasma ions gain energy as they accelerate through the potential drop across the sheath that forms at the plasma boundary. Because the sheath surrounds the target on all sides, all surfaces of the target are implanted without the necessity to raster the beam or to rotate the target. The authors have succeeded in implanting nitrogen ions in a silicon target to the depths and concentrations required for surface treatment of materials like stainless steel and titanium alloys. They have performed ESCA measurements of the penetration depth profile of a silicon target that was biased to 30 kV in a nitrogen discharge plasma. Nitrogen ions were implanted to a depth of 700A at a peak concentration of 30% atomic. The measured profile is quite similar to a previously obtained profile in titanium targets with conventional techniques

Investigation of arcing on fiber-formed nanostructured tungsten by pulsed plasma during steady state plasma irradiation

Energy Technology Data Exchange (ETDEWEB)

Yajima, M., E-mail: yajima.miyuki@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, 509-5292 Japan (Japan); Ohno, N. [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kajita, S. [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); De Temmerman, G. [ITER Organization, Route de Vinon sur Verdon, CS 90 046-13067 St Paul Lez Durance Cedex (France); Bystrov, K.; Bardin, S.; Morgan, T.W. [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Partner in the Trilateral Euregio Cluster, 5612 AJ Eindhoven (Netherlands); Masuzaki, S. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, 509-5292 Japan (Japan)

2016-11-15

Arcing on fiber-formed nanostructured tungsten samples during ELM-like pulses was investigated using the superimposition of high power pulsed plasma on a steady state plasma with hydrogen gas in the linear plasma device Pilot-PSI. The ignition of arcing was observed when the floating potential of the samples was less than −75 V with sufficient heat flux. The surface observation showed that the arc spots were not in the center, but in the peripheral area of the plasma column. Considering the plasma potential profile in the Pilot-PSI, the arcing occurred at the position where the heat flux and the sheath potential drop are sufficiently large.

Plasma cross-gestational sphingolipidomic analyses reveal potential first trimester biomarkers of preeclampsia.

Directory of Open Access Journals (Sweden)

Aneta Dobierzewska

14:0 were significantly lower in first trimester plasma of PE patients when compared with their gestational-matched control samples (p = 0.009. Major plasma sphingomyelin species (SM 16:0, SM 18:1 and SM 24:0 tended to be higher in control pregnancies across gestation. However, in PE patients, SM 16:0, SM 18:0 and SM 18:1 showed significant up-regulation across gestation, pointing to atherogenic properties of the sphingomyelins and particularly the potential contribution of SM 18:0 to the disease development. In addition, two major sphingomyelins, SM 16:0 and SM 18:0, were significantly lower in first trimester plasma of PE patients versus first trimester samples of respective controls (p = 0.007 and p = 0.002, respectively.Cross-gestational analysis of maternal plasma of preeclamptic and normotensive women identifies differences in the biochemical profile of major sphingolipids (DH-S1P, sphingomyelins and ceramides between these two groups. In addition, first trimester maternal plasma sphingolipids (Cer 14:0, SM 16:0 and SM 18:0 may serve in the future as early biomarkers of PE occurrence and development.

Measurements of the sheath potential in low density plasmas

International Nuclear Information System (INIS)

Bradley, J.W.; Khamis, R.A.; Sanduk, M.I.; Elliott, J.A.; Rusbridge, M.G.

1992-01-01

We have measured the sheath potential around a probe in a range of different plasma conditions in the UMIST, University of Manchester Institute of Science and Technology, quadrupole GOLUX and in a related experiment in which the plasma expands freely to supersonic velocity. In the latter case, the sheath potential agrees well with an appropriately modified form of the usual expression for a field-free plasma, for both hydrogen and argon plasmas. In GOLUX, however, the sheath potential is found to be significantly less than the accepted value, even when the magnetic field is taken into account. For the slow moving plasma in the outer part of the quadrupole confining field, we present both theoretical and experimental results showing that the reduction is due to truncation of the electron velocity distribution as the probe drains electrons from a closed flux tube faster than they can be replaced. In the central hot plasma, however, this explanation cannot apply. Here, the plasma is moving at about sonic speed and magnetic effects are weak. Nevertheless, the results are significantly different from both in the field free experiment. (author)

Potential profiles obtained from applied dust cloud perturbations

International Nuclear Information System (INIS)

Thomas, Edward Jr.

2002-01-01

This paper details an experimental investigation of the local potential structure within a cloud of suspended microparticles - a 'dusty' or 'complex' plasma - using particle image velocimetry (PIV) techniques. Applied perturbations, synchronized to the PIV measurements, are used to force a cloud of suspended microparticles to become unconfined. From the free-streaming motion of the particles during the loss of confinement and subsequent reformation of the dust cloud, an analysis of the potential is performed. Furthermore, a new method of analyzing the potential structure from the motion of free-streaming microparticles in the plasma is presented

Circulating plasmablasts/plasma cells: a potential biomarker for IgG4-related disease.

Science.gov (United States)

Lin, Wei; Zhang, Panpan; Chen, Hua; Chen, Yu; Yang, Hongxian; Zheng, Wenjie; Zhang, Xuan; Zhang, Fengxiao; Zhang, Wen; Lipsky, Peter E

2017-02-10

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a multisystem fibroinflammatory disease. We previously reported that a circulating cell population expressing CD19 + CD24 - CD38 hi was increased in patients with IgG4-RD. In this study, we aimed to document that this cell population represented circulating plasmablasts/plasma cells, to identify the detailed phenotype and gene expression profile of these IgG4-secreting plasmablasts/plasma cells, and to determine whether this B-cell lineage subset could be a biomarker in IgG4-related disease (IgG4-RD). A total of 42 untreated patients with IgG4-RD were evaluated. Peripheral B-cell subsets, including CD19 + CD24 - CD38 hi plasmablasts/plasma cells, CD19 + CD24 + CD38 - memory B cells, CD19 + CD24 int CD38 int naïve B cells, and CD19 + CD24 hi CD38 hi regulatory B cells, were assessed and sorted by flow cytometry. Microarray analysis was used to measure gene expression of circulating B-cell lineage subsets. Further characterization of CD19 + CD24 - CD38 hi plasmablasts/plasma cells was carried out by evaluating additional surface markers, including CD27, CD95, and human leukocyte antigen (HLA)-DR, by flow cytometric assay. In addition, various B-cell lineage subsets were cultured in vitro and IgG4 concentrations were measured by cytometric bead array. In untreated patients with IgG4-RD, the peripheral CD19 + CD24 - CD38 hi plasmablast/plasma cell subset was increased and positively correlated with serum IgG4 levels, the number of involved organs, and the IgG4-related Disease Responder Index. It decreased after treatment with glucocorticoids. Characterization of the plasmablast/plasma cell population by gene expression profiling documented a typical plasmablast/plasma cell signature with higher expression of X-box binding protein 1 and IFN regulatory factor 4, but lower expression of paired box gene 5 and B-cell lymphoma 6 protein. In addition, CD27, CD95, and HLA-DR were highly expressed on CD19 + CD24 - CD38 hi

Development of a measuring system for poloidal field profile in JIPP T-IIU plasmas

International Nuclear Information System (INIS)

Kuramoto, Hideharu; Hiraki, Naoji; Moriyama, Shin-ichi; Toi, Kazuo; Sato, Kuninori.

1995-01-01

A Zeeman polarimeter has been developed to measure the poloidal magnetic field profile in the plasma edge of the JIPP T-IIU tokamak. The poloidal field strength is determined from the analysis of circular polarization of a HeII 4686A spectral lines emitted from a plasma. The polarization modulation rate, which is proportional to the magnetic field strength along a line of sight, is estimated as a ratio of the difference between the left-hand circular polarized line intensity and right-hand one to the sum of them. A newly developed fast scanning Fabry-Perot interferometer allows us to improve a time resolution up to 1.5 ms. The poloidal magnetic field profile in He-doped deuterium plasmas of JIPP T-IIU has been successfully obtained with this polarimeter system. (author)

Confinement properties of JET plasmas with different temperature and density profiles

International Nuclear Information System (INIS)

Watkins, M.L.; Balet, B.; Bhatnagar, V.P.

1989-01-01

The confinement properties of plasmas with substantially different temperature and density profiles have been analysed. The effects of fast particles and energy pedestals on the overall confinement of plasma energy in limiter (L-mode) and X-point (L- and H-modes) discharges heated by NBI or ICRF or both are determined. The importance of the bootstrap current when such energy pedestals are formed is noted. Using sets of consistent experimental data, including ion temperature profile measurements, the local transport properties are compared in the L- and H-phases of a single null X-point medium density NBI heated discharge, the ''enhanced'' confinement phase of a limiter high density pellet-fuelled and ICRF heated discharge, the hot-ion phase of a double null X-point low density NBI heated discharge and the hot-ion and H-phases of a double null X-point low density high temperature NBI heated discharge. (author)

(1)H-Nuclear magnetic resonance-based plasma metabolic profiling of dairy cows with clinical and subclinical ketosis.

Science.gov (United States)

Sun, L W; Zhang, H Y; Wu, L; Shu, S; Xia, C; Xu, C; Zheng, J S

2014-03-01

The purpose of this study was to assess the metabolic profile of plasma samples from cows with clinical and subclinical ketosis. According to clinical signs and 3-hydroxybutyrate plasma levels, 81 multiparous Holstein cows were selected from a dairy farm 7 to 21 d after calving. The cows were divided into 3 groups: cows with clinical ketosis, cows with subclinical ketosis, and healthy control cows. (1)H-Nuclear magnetic resonance-based metabolomics was used to assess the plasma metabolic profiles of the 3 groups. The data were analyzed by principal component analysis, partial least squares discriminant analysis, and orthogonal partial least-squares discriminant analysis. The differences in metabolites among the 3 groups were assessed. The orthogonal partial least-squares discriminant analysis model differentiated the 3 groups of plasma samples. The model predicted clinical ketosis with a sensitivity of 100% and a specificity of 100%. In the case of subclinical ketosis, the model had a sensitivity of 97.0% and specificity of 95.7%. Twenty-five metabolites, including acetoacetate, acetone, lactate, glucose, choline, glutamic acid, and glutamine, were different among the 3 groups. Among the 25 metabolites, 4 were upregulated, 7 were downregulated, and 14 were both upregulated and downregulated. The results indicated that plasma (1)H-nuclear magnetic resonance-based metabolomics, coupled with pattern recognition analytical methods, not only has the sensitivity and specificity to distinguish cows with clinical and subclinical ketosis from healthy controls, but also has the potential to be developed into a clinically useful diagnostic tool that could contribute to a further understanding of the disease mechanisms. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Sex specific differences in hepatic and plasma lipid profiles in healthy cats pre and post spaying and neutering: relationship with feline hepatic lipidosis.

Science.gov (United States)

Valtolina, Chiara; Vaandrager, Arie B; Favier, Robert P; Tuohetahuntila, Maidina; Kummeling, Anne; Jeusette, Isabelle; Rothuizen, Jan; Robben, Joris H

2017-08-08

A link between lipid metabolism and disease has been recognized in cats. Since hepatic lipidosis is a frequent disorder in cats, the aim of the current study was to evaluate liver and plasma lipid dimorphism in healthy cats and the effects of gonadectomy on lipid profiling. From six female and six male cats plasma and liver lipid profiles before and after spaying/neutering were assessed and compared to five cats (three neutered male and two spayed female) diagnosed with hepatic lipidosis. Intact female cats had a significantly lower level of plasma triacylglycerides (TAG) and a higher liver level of the long chain polyunsaturated fatty acid arachidonic acid (AA) compared to their neutered state. Both male and female cats with lipidosis had a higher liver, but not plasma TAG level and an increased level of plasma and liver sphingomyelin compared to the healthy cats. Although lipid dimorphism in healthy cats resembles that of other species, intact female cats show differences in metabolic configuration that could predispose them to develop hepatic lipidosis. The increased sphingomyelin levels in cats with lipidosis could suggest a potential role in the pathogenesis of hepatic lipidosis in cats.

Measurements of Laser Plasma Instability (LPI) and Electron Density/Temperature Profiles in Plasmas Produced by the Nike KrF Laser

Science.gov (United States)

Oh, Jaechul; Weaver, J. L.; Serlin, V.; Obenschain, S. P.

2016-10-01

We will present results of simultaneous measurements of LPI-driven light scattering and density/temperature profiles in CH plasmas produced by the Nike krypton fluoride laser (λ = 248 nm). The primary diagnostics for the LPI measurement are time-resolved spectrometers with absolute intensity calibration in spectral ranges relevant to the optical detection of stimulated Raman scattering or two plasmon decay. The spectrometers are capable of monitoring signal intensity relative to thermal background radiation from plasma providing a useful way to analyze LPI initiation. For further understanding of LPI processes, the recently implemented grid image refractometer (Nike-GIR)a is used to measure the coronal plasma profiles. In this experiment, Nike-GIR is equipped with a 5th harmonic probe laser (λ = 213 nm) in attempt to probe into a high density region over the previous peak density with λ = 263 nm probe light ( 4 ×1021 cm-3). The LPI behaviors will be discussed with the measured data sets. Work supported by DoE/NNSA.

Plasma potentials and performance of the advanced electron cyclotron resonance ion source

International Nuclear Information System (INIS)

Xie, Z.Q.; Lyneis, C.M.

1994-01-01

The mean plasma potential was measured on the LBL advanced electron cyclotron resonance (AECR) ion source for a variety of conditions. The mean potentials for plasmas of oxygen, argon, and argon mixed with oxygen in the AECR were determined. These plasma potentials are positive with respect to the plasma chamber wall and are on the order of tens of volts. Electrons injected into the plasma by an electron gun or from an aluminum oxide wall coating with a very high secondary electron emission reduce the plasma potential as does gas mixing. A lower plasma potential in the AECR source coincides with enhanced production of high charged state ions indicating longer ion confinement times. The effect of the extra electrons from external injection or wall coatings is to lower the average plasma potential and to increase the n e τ i of the ECR plasma. With sufficient extra electrons, the need for gas mixing can be eliminated or reduced to a lower level, so the source can operate at lower neutral pressures. A reduction of the neutral pressure decreases charge exchange between ions and neutrals and enhances the production of high charge state ions. An aluminum oxide coating results in the lowest plasma potential among the three methods discussed and the best source performance

Analytic expressions for mode conversion in a plasma with a parabolic density profile: Generalized results

International Nuclear Information System (INIS)

Hinkel-Lipsker, D.E.; Fried, B.D.; Morales, G.J.

1993-01-01

This study provides an analytic solution to the general problem of mode conversion in an unmagnetized plasma. Specifically, an electromagnetic wave of frequency ω propagating through a plasma with a parabolic density profile of scale length L p is examined. The mode conversion points are located a distance Δ 0 from the peak of the profile, where the electron plasma frequency ω p (z) matches the wave frequency ω. The corresponding reflection, transmission, and mode conversion coefficients are expressed analytically in terms of parabolic cylinder functions for all values of Δ 0 . The method of solution is based on a source approximation technique that is valid when the electromagnetic and electrostatic scale lengths are well separated. For large Δ 0 , i.e., (cL p /ω) 1/2 much-lt Δ 0 p , the appropriately scaled result [D. E. Hinkel-Lipsker et al., Phys. Fluids B 4, 559 (1992)] for a linear density profile is recovered as the parabolic cylinder functions asymptotically become Airy functions. When Δ 0 →0, the special case of conversion at the peak of the profile [D. E. Hinkel-Lipsker et al., Phys. Fluids B 4, 1772 (1992)] is obtained

Development of concentric equipotential surfaces in bumpy torus plasma

International Nuclear Information System (INIS)

Takasugi, Keiichi; Iguchi, Harukazu; Fujiwara, Masami; Ikegami, Hideo

1983-01-01

Radial profiles of the plasma space potential are measured in Nagoya Bumpy Torus (NBT-1) by the use of a heavy ion beam probe. Asymmetric potential profiles owing to toroidal drift are observed in high pressure operation (C-mode). As the pressure is decreased, toroidal plasma is effectively heated (T-mode), poloidal precessional frequency overcomes the electron collision frequency and the equipotential surfaces becomes concentric inside the hot electron ring. (author)

Time and space-correlated plasma potential measurements in the near field of a coaxial Hall plasma discharge

International Nuclear Information System (INIS)

Smith, A. W.; Cappelli, M. A.

2009-01-01

Space- and time-correlated measurements of floating and plasma potential are made in the near field, external flow cathode region of a coaxial Hall plasma discharge using an emissive probe synchronized to quasicoherent fluctuations in discharge current. The luminous axial feature frequently observed in the near field of operating plasma accelerators is found to be concomitant with a spike in the plasma potential (and electron temperature). The structure of the plasma potential allows for multiple avenues for back-streaming ions to accelerate toward the discharge front pole and may pull some classes of ions toward the central axis. The fluctuations in plasma properties exhibit a complex structure at frequencies on the order of the so-called 'breathing mode' ionization instability often seen in these types of discharges. Most notably, the plasma potential appears to fluctuate in a helical fashion, resembling tilted drift waves rotating about the central axis. A simple analysis of these waves draws attention to the possible role that they may play in driving anomalous cross-field electron transport in the near field region.

Identification of Plasma Metabolomic Profiling for Diagnosis of Esophageal Squamous-Cell Carcinoma Using an UPLC/TOF/MS Platform

Directory of Open Access Journals (Sweden)

Lihong Yin

2013-04-01

Full Text Available Epidemiological studies indicated that esophageal squamous-cell carcinoma (ESCC is still one of the most common causes of cancer incidence in the world. Searching for valuable markers including circulating endogenous metabolites associated with the risk of esophageal cancer, is extremely important A comparative metabolomics study was performed by using ultraperformance liquid chromatography-electrospray ionization-accurate mass time-of-flight mass spectrometry to analyze 53 pairs of plasma samples from ESCC patients and healthy controls recruited in Huaian, China. The result identified a metabolomic profiling of plasma including 25 upregulated metabolites and five downregulated metabolites, for early diagnosis of ESCC. With a database-based verification protocol, 11 molecules were identified, and six upregulated molecules of interest in ESCC were found to belong to phospholipids as follows: phosphatidylserine, phosphatidic acid, phosphatidyl choline, phosphatidylinositol, phosphatidyl ethanolamine, and sphinganine 1-phosphate. Clinical estimation of metabolic biomarkers through hierarchical cluster analysis in plasma samples from 17 ESCC patients and 29 healthy volunteers indicated that the present metabolite profile could distinguish ESCC patients from healthy individuals. The cluster of aberrant expression of these metabolites in ESCC indicates the critical role of phospholipid metabolism in the oncogenesis of ESCC and suggests its potential ability to assess the risk of ESCC development in addition to currently used risk factors.

Methionine and Choline Supply during the Periparturient Period Alter Plasma Amino Acid and One-Carbon Metabolism Profiles to Various Extents: Potential Role in Hepatic Metabolism and Antioxidant Status

Directory of Open Access Journals (Sweden)

Zheng Zhou

2016-12-01

Full Text Available The objective of this study was to profile plasma amino acids (AA and derivatives of their metabolism during the periparturient period in response to supplemental rumen-protected methionine (MET or rumen-protected choline (CHOL. Forty cows were fed from −21 through 30 days around parturition in a 2 × 2 factorial design a diet containing MET or CHOL. MET supply led to greater circulating methionine and proportion of methionine in the essential AA pool, total AA, and total sulfur-containing compounds. Lysine in total AA also was greater in these cows, indicating a better overall AA profile. Sulfur-containing compounds (cystathionine, cystine, homocystine, and taurine were greater in MET-fed cows, indicating an enriched sulfur-containing compound pool due to enhanced transsulfuration activity. Circulating essential AA and total AA concentrations were greater in cows supplied MET due to greater lysine, arginine, tryptophan, threonine, proline, asparagine, alanine, and citrulline. In contrast, CHOL supply had no effect on essential AA or total AA, and only tryptophan and cystine were greater. Plasma 3-methylhistidine concentration was lower in response to CHOL supply, suggesting less tissue protein mobilization in these cows. Overall, the data revealed that enhanced periparturient supply of MET has positive effects on plasma AA profiles and overall antioxidant status.

Measurements of Pfirsch-Schlueter current and pressure profile for the high density ECH plasmas in Heliotron DR

International Nuclear Information System (INIS)

Morimoto, S.; Yanagi, N.; Nakasuga, M.; Obiki, T.; Iiyoshi, A.; Uo, K.

1988-01-01

The Pfirsch-Schlueter current and pressure profiles are estimated from magnetic measurements for high density electron cyclotron heating (ECH) plasmas (n-bar e =(2-3)x10 13 cm -3 , T e0 =200-400 eV, (β) 0 (1-(r/a) 2 ) s , is about two in macroscopically stable plasmas. A fast loss of plasma energy from the centre to the periphery is observed during the onset of the MHD instability. This method of measuring the pressure profile shape is simple and useful for heliotron type devices. (author). 20 refs, 8 figs, 1 tab

Plasma renin activity profile in normal and hypertensive Filipinos

International Nuclear Information System (INIS)

Guevara, R.; Torres, J. Jr.; Abundo, H.P.; Perez, A.P.

To establish a base line profile of plasma renin activity in normotensive and hypertensive Filipinos, 1.019 cases, 479 males and 540 females with an age range 14 - 89 years (mean - 46 + -20) were studied at the Santo Tomas University Hospital of various life styles from the Metro-Manila area, 248 comprised the normotensive group (male - 122 or 49.2 %, female 126 or 50.8 %) and 771 were hypertensive. Of these, 711 (92.6 %) has essential hypertension and are presented in this report. Plasma Renin Activity was determined by radioimmunoassay using Dainabot Renin-Ricket. Concurrent 24 hr. urine sodium and potassium were determined. Nomograms of plasma renin activity as related to urine sodium excretion were drawn after computerized statistical analysis of data. The normal mean value of plasma renin activity was found to be 1.64 + - 0.81 ng./ml./hr. in the upright position and 1.15 + - .68 ng./ml./hr. in the supine position. Based on the nomogram derived, the values obtained in the 711 cases of essential hypertension were classified into High Renin - 14.3 % Normal Renin - 56.1 % and Low Renin - 29.6 %. This study establishes normal levels of plasma renin activity as well as define and classify same renin activity among hypertensive Filipinos, a useful and practicable guide for treatment and can be of prognostic significance. (author)

Lyman series profiles: From laser-plasmas to white dwarf stars

Energy Technology Data Exchange (ETDEWEB)

Kielkopf, J.F. [University of Louisville, Louisville, Kentucky 40292 (United States); Allard, N.F. [Observatoire de Paris-Meudon, France and Institut d Astrophysique, Paris (France)

1999-04-01

The low energy interactions of neutral and ionized hydrogen atoms are fundamental processes which also have important applications to the diagnostics of laboratory and astrophysical plasmas. Satellites in the far wings of Lyman {alpha} and Lyman {beta} have been identified as ultraviolet absorption features in the spectra of white dwarf and {lambda} Bootis stars, and they are seen in the emission spectra of plasmas produced when a pulsed laser excites a target H{sub 2} gas. The observed Lyman series profiles agree with unified line shape theory which includes variation of the dipole transition moment during the radiative collision. {copyright} {ital 1999 American Institute of Physics.}

Plasma Steroid Metabolome Profiling for Diagnosis and Subtyping Patients with Cushing Syndrome.

Science.gov (United States)

Eisenhofer, Graeme; Masjkur, Jimmy; Peitzsch, Mirko; Di Dalmazi, Guido; Bidlingmaier, Martin; Grüber, Matthias; Fazel, Julia; Osswald, Andrea; Beuschlein, Felix; Reincke, Martin

2018-03-01

Diagnosis of Cushing syndrome requires a multistep process that includes verification of hypercortisolism followed by identification of the cause of adrenocortical hyperfunction. This study assessed whether pituitary, ectopic, and adrenal subtypes of Cushing syndrome were characterized by distinct plasma steroid profiles that might assist diagnosis. In this retrospective cross-sectional study, mass spectrometric measurements of a panel of 15 plasma steroids were applied to 222 patient samples tested for Cushing syndrome. Disease was excluded in 138 and confirmed in 51 patients with pituitary Cushing syndrome, 12 with ectopic adrenocorticotropin secretion, and 21 with adrenal disease. Another 277 age- and sex-matched hypertensive and normotensive volunteers were included for comparison. Compared with patients without disease, the largest increases in plasma steroids among patients with Cushing syndrome were observed for 11-deoxycortisol (289%), 21-deoxycortisol (150%), 11-deoxycorticosterone (133%), corticosterone (124%), and cortisol (122%). Patients with ectopic disease showed the most prominent increases, but there was considerable variation for other steroids according to subtype. Patients with adrenal disease had the lowest concentrations of androgens, whereas those with ectopic and pituitary disease showed the lowest concentrations of aldosterone. Plasma 18-oxocortisol was particularly low in ectopic disease. With the use of 10 selected steroids, subjects with and without different Cushing syndrome subtypes could be discriminated nearly as closely as with the use of salivary and urinary free cortisol, dexamethasone-suppressed cortisol, and plasma adrenocorticotropin (9.5% vs 5.8% misclassification). Patients with different subtypes of Cushing syndrome show distinctive plasma steroid profiles that may offer a supplementary single-test alternative for screening purposes. © 2017 American Association for Clinical Chemistry.

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

Energy Technology Data Exchange (ETDEWEB)

Schuster, Eugenio

2014-05-02

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

A statistical approach for predicting thermal diffusivity profiles in fusion plasmas as a transport model

International Nuclear Information System (INIS)

Yokoyama, Masayuki

2014-01-01

A statistical approach is proposed to predict thermal diffusivity profiles as a transport “model” in fusion plasmas. It can provide regression expressions for the ion and electron heat diffusivities (χ i and χ e ), separately, to construct their radial profiles. An approach that this letter is proposing outstrips the conventional scaling laws for the global confinement time (τ E ) since it also deals with profiles (temperature, density, heating depositions etc.). This approach has become possible with the analysis database accumulated by the extensive application of the integrated transport analysis suite to experiment data. In this letter, TASK3D-a analysis database for high-ion-temperature (high-T i ) plasmas in the LHD (Large Helical Device) is used as an example to describe an approach. (author)

Effects of sex, age, and fasting conditions on plasma lipidomic profiles of fasted Sprague-Dawley rats.

Directory of Open Access Journals (Sweden)

Kosuke Saito

Full Text Available Circulating lipid molecules reflect biological processes in the body and, thus, are useful tools for preclinical estimation of the efficacy and safety of newly developed drugs. However, background information on profiles of circulating lipid molecules in preclinical animal models is limited. Therefore, we examined the effects of multiple factors such as sex (fasted male vs. female, age (fasted 10 vs. 30 weeks old, and feeding conditions (feeding vs. fasting, 16 vs. 22 hr fasting, 10 AM vs. 4 PM blood collection, on the global profiles of lipid molecules in plasma from Sprague-Dawley rats by using a lipidomic approach. Our assay platform determined 262 lipid molecules (68 phospholipids, 20 sphingolipids, 138 neutral lipids, and 36 polyunsaturated fatty acids and their metabolites in rat plasma. Multivariate discriminant analysis (orthogonal partial least squares discriminant analysis and heat maps of statistically significant lipid molecules revealed that the plasma lipid profiles in rats are predominantly influenced by feeding conditions, followed by sex and age. In addition, the fasting duration (16 vs. 22 hr fasting or the time of blood collection (10 AM vs. 4 PM blood collection has limited or no contribution on the profiles of lipid molecules in rat plasma. Our results provide useful, fundamental information for exploring and validating biomarkers in future preclinical studies and may help to establish regulatory standards for such studies.

Impact of rotational-transform profile control on plasma confinement and stability in CHS

International Nuclear Information System (INIS)

Toi, K.; Morisaki, T.; Sakakibara, S.

1994-08-01

In neutral beam heated plasmas of CHS, which is a low aspect-ration heliotron/torsatron device, the effect of rotational transform (ι) profile shape on plasma confinement and stability is studied by inducing a net plasma current (Ip). In the case that the external ι is increased by Ip, very rapid H-mode transition (within ∼0.2 ms) is observed at the thresholds of Ip and heating power, having all characteristics found in the tokamak H-mode. There is no obvious difference in the H-mode characteristics between deuterium and hydrogen plasmas. In the opposite case that the external ι is decreased by reversing Ip, the H-mode transition is not observed. (author)

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

International Nuclear Information System (INIS)

Christ-Koch, Sina

2007-01-01

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

Abnormalities in plasma and red blood cell fatty acid profiles of patients with colorectal cancer.

OpenAIRE

Bar??, L.; Hermoso, J. C.; N????ez, M. C.; Jim??nez-Rios, J. A.; Gil, A.

1998-01-01

We evaluated total plasma fatty acid concentrations and percentages, and the fatty acid profiles for the different plasma lipid fractions and red blood cell lipids, in 17 patients with untreated colorectal cancer and 12 age-matched controls with no malignant diseases, from the same geographical area. Cancer patients had significantly lower total plasma concentrations of saturated, monounsaturated and essential fatty acids and their polyunsaturated derivatives than healthy controls; when the v...

Design of an O-mode frequency modulated reflectometry system for the measurement of Alborz Tokamak plasma density profile

Energy Technology Data Exchange (ETDEWEB)

Koohestani, Saeideh [Department of Energy Engineering and physics, Amirkabir University of Technology, Tehran, 15875-4413, Islamic Republic of Iran (Iran, Islamic Republic of); Amrollahi, Reza, E-mail: amrollahi@aut.ac.ir [Department of Energy Engineering and physics, Amirkabir University of Technology, Tehran, 15875-4413, Islamic Republic of Iran (Iran, Islamic Republic of); Moradi, Gholamreza [Department of Electrical Engineering, Amirkabir University of Technology, Tehran, 15875-4413, Islamic Republic of Iran (Iran, Islamic Republic of)

2016-12-15

Reflectometry is a common method for plasma diagnostic, in which microwaves are launched into the plasma and reflected at the critical surfaces. Comparing the reflected microwave signals with the launched waves would give rise to the plasma density profiles. In the present study, an ordinary mode (O-mode) frequency modulation (FM) reflectometry system has been designed for the electron density profile measurement of the Alborz Tokamak plasma. This system has been considered to operate at K-band (18–26.5 GHz) frequency range and scan the frequency band between 18 to 26 GHz in 40 μS. The density profile from major radius r = 47.9–51.55 cm can be measured in Alborz Tokamak plasma. Based on the Alborz Tokamak operational conditions, the characteristic frequencies, and some dimensional limitations, all parts of reflectometer have been designed so that an appropriate efficiency with minimum attenuation, especially in transmitting/receiving system would be achieved. A dual antenna and an oversized waveguide of X-band (8–12 GHz) for transmitting and receiving purposes and a balanced detector for absolute phase determination have been utilized. The details of the Alborz Tokamak FM reflectometry components focusing on the antenna and waveguide design and mounting are described in this paper. Additionally, the procedure of plasma profile reconstruction using the system output signal is discussed. This system uses signal phase shift to determine the position of the cutoff layer.

Plasma microRNA profiles distinguish lethal injury in acetaminophen toxicity: A research study

Institute of Scientific and Technical Information of China (English)

Jeanine Ward; Shashi Bala; Jan Petrasek; Gyongyi Szabo

2012-01-01

AIM:To investigate plasma microRNA (miRNA) profiles indicative of hepatotoxicity in the setting of lethal acetaminophen (APAP) toxicity in mice.METHODS:Using plasma from APAP poisoned mice,either lethally (500 mg/kg) or sublethally (150 mg/kg) dosed,we screened commercially available murine microRNA libraries (SABiosciences,Qiagen Sciences,MD) to evaluate for unique miRNA profiles between these two dosing parameters.RESULTS:We distinguished numerous,unique plasma miRNAs both up- and downregulated in lethally compared to sublethally dosed mice.Of note,many of the greatest up- and downregulated miRNAs,namely 574-5p,466g,466f-3p,375,29c,and 148a,have been shown to be associated with asthma in prior studies.Interestingly,a relationship between APAP and asthma has been previously well described in the literature,with an as yet unknown mechanism of pathology.There was a statistically significant increase in alanine aminotransferase levels in the lethal compared to sublethal APAP dosing groups at the 12 h time point (P ＜0.001).There was 90％ mortality in the lethally compared to sublethally dosed mice at the 48 h time point (P =0.011).CONCLUSION:We identified unique plasma miRNAs both up- and downregulated in APAP poisoning which are correlated to asthma development.

Analytic analysis on asymmetrical micro arcing in high plasma potential RF plasma systems

International Nuclear Information System (INIS)

Yin, Y; McKenzie, D R; Bilek, M M M

2006-01-01

We report experimental and analytical results on asymmetrical micro arcing in a RF (radio frequency) plasma. Micro arcing, resulting from high plasma potential, in RF plasma was found to occur only on the grounded electrode for a variety of electrode and surface configurations. The analytic derivation was based on a simple RF time-dependent Child-Langmuir sheath model and electric current continuity. We found that the minimum potential difference in one RF period across the grounded electrode sheath depends on the area ratio of the grounded electrode to the powered electrode. As the area ratio increases, the minimum potential difference across a sheath increases for the grounded electrode but not for the RF powered electrode. We showed that discharge time in micro arcing is more than 100 RF periods; thus the presence of a continuous high electric field in one RF cycle results in micro arcing on the grounded electrode. However, the minimum potential difference in one RF period across the powered electrode sheath is always small so that it prevents micro arcing occurring even though the average sheath voltage can be large. This simple analytic model is consistent with particle-in-cell simulation results

Evaluation of body mass index and plasma lipid profile in dogs ...

African Journals Online (AJOL)

This study evaluated the body mass index (BMI), plasma lipid profile and gait assessment score (GAS) in dogs. Body weights (BW), height (H) at shoulder and waist circumference (WC) were obtained from fifty client-owned dogs of both sexes to determine the BMI. In addition, body condition score (BCS) and GAS were ...

Evaluation of body mass index and plasma lipid profile in Boerboel ...

African Journals Online (AJOL)

This study evaluated the body mass index (BMI) and plasma lipid profile in Boerboel dogs. Body weights (BW), height (H) at shoulder and waist circumference (WC) were obtained from fifty-three Boerboels to determine the BMI while, body condition score (BCS) was determined subjectively. Also 5mls of blood was obtained ...

Comparative study of the electron density profiles in the compact torus plasma merging experiments

International Nuclear Information System (INIS)

Hayashiya, Hitoshi; Asaka, Takeo; Katsurai, Makoto

2003-01-01

Following two previous papers on the comparative studies of the electron density distributions for a single compact torus (CT) and a spherical tokamak (ST), and for the a single ST and a merged ST, a comparative study on the dynamics of the electron density profile and after the CT and ST plasma merging process was performed. The sharpness of the peak in the electron density profile around the mid-plane just after the merging of CT with a low safety factor (q value) such as RFP or spheromak is found to be related to the speed of the magnetic axis during the plasma merging process. It is also found that the electron density gradient near the plasma edge in a high q ST is larger than that of a low q CT. High q ST is found to be provided with the magnetic structure which is able to sustain a large thermal pressure by a strong j x B force. Despite these differences in the electron density profile between CT and ST during merging, the confinement characteristics evaluated from the number of electrons confined within the magnetic separatrix after the completion of the merging is almost similar between in the merging CT and in the merging ST. For all configurations, the electron density profiles after the completion of the merging are analogous to those of the corresponding single configuration produced without the merging process. (author)

Dust in flowing magnetized plasma

International Nuclear Information System (INIS)

Pandey, Birendra P.; Samarian, Alex A.; Vladimirov, Sergey V.

2009-01-01

Plasma flows occur in almost every laboratory device and interactions of flowing plasmas with near-wall impurities and/or dust significantly affects the efficiency and lifetime of such devices. The charged dust inside the magnetized flowing plasma moves primarily under the influence of the plasma drag and electric forces. Here, the charge on the dust, plasma potential, and plasma density are calculated self-consistently. The electrons are assumed non-Boltzmannian and the effect of electron magnetization and electron-atom collisions on the dust charge is calculated in a self-consistent fashion. For various plasma magnetization parameters viz. the ratio of the electron and ion cyclotron frequencies to their respective collision frequencies, plasma-atom and ionization frequencies, the evolution of the plasma potential and density in the flow region is investigated. The variation of the dust charge profile is shown to be a sensitive function of plasma parameters. (author)

Space potential, temperature, and density profile measurements on RENTOR

International Nuclear Information System (INIS)

Schoch, P.M.

1983-05-01

Radial profiles of the space potential, electron temperature, and density have been measured on RENTOR with a heavy-ion-beam probe. The potential profile has been compared to predictions from a stochastic magnetic field fluctuation theory, using the measured temperature and density profiles. The comparison shows strong qualitative agreement in that the potential is positive and the order of T/sub e//e. There is some quantitative disagreement in that the measured radial electric fields are somewhat smaller than the theoretical predictions. To facilitate this comparison, a detailed analysis of the possible errors has been completed

Methods for direct measurement of the plasma potential

DEFF Research Database (Denmark)

Andersen, S. A.; Christoffersen, G. B.; Jensen, Vagn Orla

1972-01-01

Reports on a simple experimental technique which can be used for determination of the plasma where the plasma potential prevails; these ions are accepted by the analyser plate when phi c= phi pl. Part of this technique has been used by Andersen, Jensen, Michelsen and Nielsen (1971) in measurements...

Fast potential change in sawteeth in JIPP T-IIU tokamak plasmas

International Nuclear Information System (INIS)

Hamada, Y.; Nishizawa, A.; Kawasumi, Y.

1994-12-01

Fast changes of electric potential with different polarities are observed during sawtooth oscillation in a core region of a tokamak plasma using a heavy ion beam probe. The potential change inside the inversion radius is found to be positive. The change is negative outside the inversion radius and shows clearly a propagation nature. The observed potential can be interpreted by the mixture of the potentials of two origins. One of them drives the fast MHD plasma motion through E/B drift and the other is a barrier potential induced by mixing of hot and cold plasmas at sawtooth crash. (author)

Measuring the Plasma Density of a Ferroelectric Plasma Source in an Expanding Plasma

International Nuclear Information System (INIS)

Dunaevsky, A.; Fisch, N.J.

2003-01-01

The initial density and electron temperature at the surface of a ferroelectric plasma source were deduced from floating probe measurements in an expanding plasma. The method exploits negative charging of the floating probe capacitance by fast flows before the expanding plasma reaches the probe. The temporal profiles of the plasma density can be obtained from the voltage traces of the discharge of the charged probe capacitance by the ion current from the expanding plasma. The temporal profiles of the plasma density, at two different distances from the surface of the ferroelectric plasma source, could be further fitted by using the density profiles for the expanding plasma. This gives the initial values of the plasma density and electron temperature at the surface. The method could be useful for any pulsed discharge, which is accompanied by considerable electromagnetic noise, if the initial plasma parameters might be deduced from measurements in expanding plasma

Self-organized profile relaxation by ion temperature gradient instability in toroidal plasmas

International Nuclear Information System (INIS)

Kishimoto, Y.; Tajima, T.; LeBrun, M.J.; Gray, M.G.; Kim, J.Y.; Horton, W.

1993-02-01

Toroidal effects on the ion-temperature gradient mode are found to dictate the temperature evolution and the subsequent relaxed profile realization according to our toroidal particle simulation. Both in the strongly unstable fluid regime as well as in the near-marginal kinetic regime we observe that the plasma maintains an exponential temperature profile and forces the heat flux to be radially independent. The self-organized critical relaxed state is sustained slightly above the marginal stability, where the weak wave growth balances the wave decorrelation

Profiling post-centrifugation delay of serum and plasma with antibody bead arrays.

Science.gov (United States)

Qundos, Ulrika; Hong, Mun-Gwan; Tybring, Gunnel; Divers, Mark; Odeberg, Jacob; Uhlen, Mathias; Nilsson, Peter; Schwenk, Jochen M

2013-12-16

Several biobanking initiatives have emerged to create extensive collections of specimen for biomedical studies and various analytical platforms. An affinity proteomic analysis with antibody suspension bead arrays was conducted to investigate the influence of the pre-analytical time and temperature conditions on blood derived samples. Serum and EDTA plasma prepared from 16 individuals was centrifuged and aliquots were kept either at 4°C or in ambient temperature for 1h and up to 36h prior to first storage. Multiplexed protein profiles of post-centrifugation delay were generated in 384 biotinylated samples using 373 antibodies that targeted 343 unique proteins. Very few profiles were observed as significantly altered by the studied temperature and time intervals. Single binder and sandwich assays revealed decreasing levels of caldesmon 1 (CALD1) related to EDTA standard tubes and prolonged post-centrifugation delay of 36h. Indications from changes in CALD1 levels require further confirmation in independent material, but the current data suggests that samples should preferentially be frozen during the day of collection when to be profiled with antibody arrays selected for this study. Affinity-based profiling of serum and plasma by microarray assays can provide unique opportunities for the discovery of biomarkers. It is though often not known how differences in sample handling after collection influence the downstream analysis. By profiling three types of blood preparations for alterations in protein profiles with respect to time and temperature post centrifugation, we addressed an important component in the analysis and of such specimen. We believe that this analysis adds valuable information to be considered when biobanking blood derived samples. This article is part of a Special Issue entitled: Standardization and Quality Control in Proteomics. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Field-aligned plasma-potential structure formed by local electron cyclotron resonance

International Nuclear Information System (INIS)

Hatakeyama, Rikizo; Kaneko, Toshiro; Sato, Noriyoshi

2001-01-01

The significance of basic experiments on field-aligned plasma-potential structure formed by local electron cyclotron resonance (ECR) is claimed based on the historical development of the investigation on electric double layer and electrostatic potential confinement of open-ended fusion-oriented plasmas. In the presence of a single ECR point in simple mirror-type configurations of magnetic field, a potential dip (thermal barrier) appears around this point, being followed by a subsequent potential hump (plug potential) along a collisionless plasma flow. The observed phenomenon gives a clear-cut physics to the formation of field-aligned plug potential with thermal barrier, which is closely related to the double layer formation triggered by a negative dip. (author)

Clinical significance of determination of plasma NPY levels and serum lipid profile in patients with cerebral hemorrhage and cerebral infarction

International Nuclear Information System (INIS)

Huang Fujuan; Shen Airong; Yang Yongqing

2010-01-01

Objective: To study the clinical significance of changes of plasma NPY levels and serum lipid profile in patients with cerebral hemorrhage and cerebral infarction. Methods: Plasma NPY levels (with RIA) and serum lipid profile (with biochemistry) were determined in (1) 48 patients with acute cerebral hemorrhage (2) 46 patients with acute cerebral infarction and (3) controls.Results Plasma NPY levels in both patients with cerebral hemorrhage and patients with cerebral infarction were significantly higher than those in controls (P 0.05). Conclusion: NPY played important roles in the development and pathogenesis of cerebral vascular accidents. Lipid profile changes was the basic etiological factor. (authors)

Status and potential of atmospheric plasma processing of materials

Energy Technology Data Exchange (ETDEWEB)

Pappas, Daphne [United States Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005 (United States)

2011-03-15

This paper is a review of the current status and potential of atmospheric plasma technology for materials processing. The main focus is the recent developments in the area of dielectric barrier discharges with emphasis in the functionalization of polymers, deposition of organic and inorganic coatings, and plasma processing of biomaterials. A brief overview of both the equipment being used and the physicochemical reactions occurring in the gas phase is also presented. Atmospheric plasma technology offers major industrial, economic, and environmental advantages over other conventional processing methods. At the same time there is also tremendous potential for future research and applications involving both the industrial and academic world.

Status and potential of atmospheric plasma processing of materials

International Nuclear Information System (INIS)

Pappas, Daphne

2011-01-01

This paper is a review of the current status and potential of atmospheric plasma technology for materials processing. The main focus is the recent developments in the area of dielectric barrier discharges with emphasis in the functionalization of polymers, deposition of organic and inorganic coatings, and plasma processing of biomaterials. A brief overview of both the equipment being used and the physicochemical reactions occurring in the gas phase is also presented. Atmospheric plasma technology offers major industrial, economic, and environmental advantages over other conventional processing methods. At the same time there is also tremendous potential for future research and applications involving both the industrial and academic world.

Direct measurements of the plasma potential in ELMy H-mode plasma with ball-pen probes on ASDEX Upgrade tokamak

Energy Technology Data Exchange (ETDEWEB)

Adamek, J., E-mail: adamek@ipp.cas.c [Institute of Plasma Physics, Association EURATOM/IPP.CR, Prague, Za Slovankou 3, 182 00, Prague 8 (Czech Republic); Rohde, V.; Mueller, H.W.; Herrmann, A. [Institute of Plasma Physics, Association EURATOM/IPP, Garching (Germany); Ionita, C.; Schrittwieser, R.; Mehlmann, F. [Institute for Ion Physics and Applied Physics, University of Innsbruck, Association EURATOM/OAW (Austria); Stoeckel, J.; Horacek, J.; Brotankova, J. [Institute of Plasma Physics, Association EURATOM/IPP.CR, Prague, Za Slovankou 3, 182 00, Prague 8 (Czech Republic)

2009-06-15

Experimental investigations of the plasma potential and electric field were performed for ELMy H-mode plasmas in the vicinity of the limiter shadow of ASDEX Upgrade. A fast reciprocating probe with a probe head containing four ball-pen probes (BPPs) [J. Adamek et al., Czech. J. Phys. 54 (2004) C95 - C99.] was used on the midplane manipulator. Different gradients of the plasma potential were observed during ELMs and in between them. The temporal resolution of the direct plasma potential measurements with BPP was determined by using power-spectra analysis.

Plasma and Urinary Phenolic Profiles after Acute and Repetitive Intake of Wild Blueberry

Directory of Open Access Journals (Sweden)

Rodrigo P. Feliciano

2016-08-01

Full Text Available Recent studies have shown that blueberries may have cardiovascular and cognitive health benefits. In this work, we investigated the profile of plasma and urine (polyphenol metabolites after acute and daily consumption of wild blueberries for 30 days in 18 healthy men. The inter-individual variability in plasma and urinary polyphenol levels was also investigated. Blood samples were collected at baseline and 2 h post-consumption on day 1 and day 30. Twenty-four-hour urine was also collected on both days. A total of 61 phenolic metabolites were quantified in plasma at baseline, of which 43 increased after acute or chronic consumption of blueberries over one month. Benzoic and catechol derivatives represented more than 80% of the changes in phenolic profile after 2 h consumption on day 1, whereas hippuric and benzoic derivatives were the major compounds that increased at 0 and 2 h on day 30, respectively. The total (polyphenol urinary excretion remained unchanged after 30 days of wild blueberry intake. The inter-individual variability ranged between 40%–48% in plasma and 47%–54% in urine. Taken together, our results illustrate that blueberry (polyphenols are absorbed and extensively metabolized by phase II enzymes and by the gut microbiota, leading to a whole array of metabolites that may be responsible for the beneficial effects observed after blueberry consumption.

Plasma and Urinary Phenolic Profiles after Acute and Repetitive Intake of Wild Blueberry.

Science.gov (United States)

Feliciano, Rodrigo P; Istas, Geoffrey; Heiss, Christian; Rodriguez-Mateos, Ana

2016-08-25

Recent studies have shown that blueberries may have cardiovascular and cognitive health benefits. In this work, we investigated the profile of plasma and urine (poly)phenol metabolites after acute and daily consumption of wild blueberries for 30 days in 18 healthy men. The inter-individual variability in plasma and urinary polyphenol levels was also investigated. Blood samples were collected at baseline and 2 h post-consumption on day 1 and day 30. Twenty-four-hour urine was also collected on both days. A total of 61 phenolic metabolites were quantified in plasma at baseline, of which 43 increased after acute or chronic consumption of blueberries over one month. Benzoic and catechol derivatives represented more than 80% of the changes in phenolic profile after 2 h consumption on day 1, whereas hippuric and benzoic derivatives were the major compounds that increased at 0 and 2 h on day 30, respectively. The total (poly)phenol urinary excretion remained unchanged after 30 days of wild blueberry intake. The inter-individual variability ranged between 40%-48% in plasma and 47%-54% in urine. Taken together, our results illustrate that blueberry (poly)phenols are absorbed and extensively metabolized by phase II enzymes and by the gut microbiota, leading to a whole array of metabolites that may be responsible for the beneficial effects observed after blueberry consumption.

Modelling of profile control with LH wave injection in the HL-2A single-null divertor plasma

International Nuclear Information System (INIS)

Gao Qingdi; Yuan Baoshan; Li Fangzhu; Wang, Aike; Budny, R.V.

2005-01-01

In the HL-2A tokamak a single-null divertor configuration has been established. The separatrix of the single-null diverted plasma was identified with a filament model, and the determined striking area on the target plate is in agreement with the measurements of electric probe array. Higher power LH wave (1.5MW) is injected to the diverted plasma with a nearly symmetric spectrum. Dominant electron heating and current profile control are investigated with numerical simulation. Plasma heating by electron Landau interaction results in operation scenarios of preferentially dominant electron heating. Due to the off-axis driven current, an optimized q-profile is formed, and an enhanced confinement regime with steep electron temperature gradient is produced. The clear decrease of the electron thermal conductivity in the LH power deposition region shows that an electron-ITB is developed. When higher LH power injects into the target plasma that is heated by NBI (0.5MW), the ion temperature has a large increment in addition to the high increase of electron temperature. The temperature profiles indicate that an enhanced core confinement is established with both ion-ITB and electron-ITB developed. (author)

Plasma diagnostics with a retarding potential analyzer

International Nuclear Information System (INIS)

Jack, T.M.

1996-01-01

The plasma rocket is located at NASA Johnson Space Center. To produce a thrust in space, an inert gas is ionized into a plasma and heated in the linear section of a tokamak fusion device. The magnetic field used to contain the plasma has a magnitude of 2--10 kGauss. The plasma plume has a variable thrust and specific impulse. A high temperature retarding potential analyzer (RPA) is being developed to characterize the plasma in the plume and at the edge of the magnetically contained plasma. The RPA measures the energy and density of ions or electrons entering into its solid angle of collection. An oscilloscope displays the ion flux versus the collected current. All measurements are made relative to the facility ground. Testing of this device involves the determination of its output parameters, sensitivity, and responses to a wide range of energies and densities. Each grid will be tested individually by changing only its voltage and observing the output from the RPA. To verify that the RPA is providing proper output, it is compared to the output from a Langmuir or Faraday probe

Plasma metabolomic profiles of breast cancer patients after short-term limonene intervention.

Science.gov (United States)

Miller, Jessica A; Pappan, Kirk; Thompson, Patricia A; Want, Elizabeth J; Siskos, Alexandros P; Keun, Hector C; Wulff, Jacob; Hu, Chengcheng; Lang, Julie E; Chow, H-H Sherry

2015-01-01

Limonene is a lipophilic monoterpene found in high levels in citrus peel. Limonene demonstrates anticancer properties in preclinical models with effects on multiple cellular targets at varying potency. While of interest as a cancer chemopreventive, the biologic activity of limonene in humans is poorly understood. We conducted metabolite profiling in 39 paired (pre/postintervention) plasma samples from early-stage breast cancer patients receiving limonene treatment (2 g QD) before surgical resection of their tumor. Metabolite profiling was conducted using ultra-performance liquid chromatography coupled to a linear trap quadrupole system and gas chromatography-mass spectrometry. Metabolites were identified by comparison of ion features in samples to a standard reference library. Pathway-based interpretation was conducted using the human metabolome database and the MetaCyc database. Of the 397 named metabolites identified, 72 changed significantly with limonene intervention. Class-based changes included significant decreases in adrenal steroids (P limonene resulted in significant changes in several metabolic pathways. Furthermore, pathway-based changes were related to the change in tissue level cyclin D1 expression. Future controlled clinical trials with limonene are necessary to determine the potential role and mechanisms of limonene in the breast cancer prevention setting. ©2014 American Association for Cancer Research.

Plasma Profile and Shape Optimization for the Advanced Tokamak Power Plant, ARIES-AT

International Nuclear Information System (INIS)

Kessel, C.E.; Mau, T.K.; Jardin, S.C.; Najmabadi, F.

2001-01-01

An advanced tokamak plasma configuration is developed based on equilibrium, ideal-MHD stability, bootstrap current analysis, vertical stability and control, and poloidal-field coil analysis. The plasma boundaries used in the analysis are forced to coincide with the 99% flux surface from the free-boundary equilibrium. Using an accurate bootstrap current model and external current-drive profiles from ray-tracing calculations in combination with optimized pressure profiles, beta(subscript N) values above 7.0 have been obtained. The minimum current drive requirement is found to lie at a lower beta(subscript N) of 5.4. The external kink mode is stabilized by a tungsten shell located at 0.33 times the minor radius and a feedback system. Plasma shape optimization has led to an elongation of 2.2 and triangularity of 0.9 at the separatrix. Vertical stability could be achieved by a combination of tungsten shells located at 0.33 times the minor radius and feedback control coils located behind the shield. The poloidal-field coils were optimized in location and current, providing a maximum coil current of 8.6 MA. These developments have led to a simultaneous reduction in the power plant major radius and toroidal field

Plasma Protein Profiles Differ Between Women Diagnosed with Cervical Intraepithelial Neoplasia (CIN 1 and 3

Directory of Open Access Journals (Sweden)

Edward E. Partridge

2006-01-01

Full Text Available Early detection of precancerous cells in the cervix and their clinical management is the main purpose of cervical cancer prevention and treatment programs. Cytological findings or testing for high risk (HR-human papillomavirus (HPV are inadequately sensitive for use in triage of women at high risk for cervical cancer. The current study is an exploratory study to identify candidate surface-enhanced laser desorption/ionization (SELDI time of flight (TOF mass spectrometry (MS protein profiles in plasma that may distinguish cervical intraepithelial neoplasia (CIN 3 from CIN 1 among women infected with HR-HPV. We evaluated the SELDI-TOF-MS plasma protein profiles of HR-HPV positive 32 women with CIN 3 (cases and 28 women with CIN1 (controls. Case-control status was kept blinded and triplicates of each sample and quality control plasma samples were randomized and after robotic sample preparations were run on WCX2 chips. After alignment of mass/charge (m-z values, an iterative method was used to develop a classifier on a training data set that had 28 cases and 22 controls. The classifier developed was used to classify the subjects in a test data set that has six cases and six controls. The classifier separated the cases from controls in the test set with 100% sensitivity and 100% specificity suggesting the possibility of using plasma SELDI protein profiles to identify women who are likely to have CIN 3 lesions.

Plasma low-molecular-weight proteome profiling identified neuropeptide-Y as a prostate cancer biomarker polypeptide.

Science.gov (United States)

Ueda, Koji; Tatsuguchi, Ayako; Saichi, Naomi; Toyama, Atsuhiko; Tamura, Kenji; Furihata, Mutsuo; Takata, Ryo; Akamatsu, Shusuke; Igarashi, Masahiro; Nakayama, Masato; Sato, Taka-Aki; Ogawa, Osamu; Fujioka, Tomoaki; Shuin, Taro; Nakamura, Yusuke; Nakagawa, Hidewaki

2013-10-04

In prostate cancer diagnosis, PSA test has greatly contributed to the early detection of prostate cancer; however, expanding overdiagnosis and unnecessary biopsies have emerged as serious issues. To explore plasma biomarkers complementing the specificity of PSA test, we developed a unique proteomic technology QUEST-MS (Quick Enrichment of Small Targets for Mass Spectrometry). The QUEST-MS method based on 96-well formatted sequential reversed-phase chromatography allowing efficient enrichment of <20 kDa proteins quickly and reproducibly. Plasma from 24 healthy controls, 19 benign prostate hypertrophy patients, and 73 prostate cancer patients were purified with QUEST-MS and analyzed by LC/MS/MS. Among 153 057 nonredundant peptides, 189 peptides showed prostate cancer specific detection pattern, which included a neurotransmitter polypeptide neuropeptide-Y (NPY). We further validated the screening results by targeted multiple reaction monitoring technology using independent sample set (n = 110). The ROC curve analysis revealed that logistic regression-based combination of NPY, and PSA showed 81.5% sensitivity and 82.2% specificity for prostate cancer diagnosis. Thus QUEST-MS technology allowed comprehensive and high-throughput profiling of plasma polypeptides and had potential to effectively uncover very low abundant tumor-derived small molecules, such as neurotransmitters, peptide hormones, or cytokines.

Properties of ion temperature gradient and trapped electron modes in tokamak plasmas with inverted density profiles

Science.gov (United States)

Du, Huarong; Jhang, Hogun; Hahm, T. S.; Dong, J. Q.; Wang, Z. X.

2017-12-01

We perform a numerical study of linear stability of the ion temperature gradient (ITG) mode and the trapped electron mode (TEM) in tokamak plasmas with inverted density profiles. A local gyrokinetic integral equation is applied for this study. From comprehensive parametric scans, we obtain stability diagrams for ITG modes and TEMs in terms of density and temperature gradient scale lengths. The results show that, for the inverted density profile, there exists a normalized threshold temperature gradient above which the ITG mode and the TEM are either separately or simultaneously unstable. The instability threshold of the TEM for the inverted density profile is substantially different from that for normal and flat density profiles. In addition, deviations are found on the ITG threshold from an early analytic theory in sheared slab geometry with the adiabatic electron response [T. S. Hahm and W. M. Tang, Phys. Fluids B 1, 1185 (1989)]. A possible implication of this work on particle transport in pellet fueled tokamak plasmas is discussed.

Scaling of laser-plasma interactions with laser wavelength and plasma size

International Nuclear Information System (INIS)

Max, C.E.; Campbell, E.M.; Mead, W.C.; Kruer, W.L.; Phillion, D.W.; Turner, R.E.; Lasinski, B.F.; Estabrook, K.G.

1983-01-01

Plasma size is an important parameter in wavelength-scaling experiments because it determines both the threshold and potential gain for a variety of laser-plasma instabilities. Most experiments to date have of necessity produced relatively small plasmas, due to laser energy and pulse-length limitations. We have discussed in detail three recent Livermore experiments which had large enough plasmas that some instability thresholds were exceeded or approached. Our evidence for Raman scatter, filamentation, and the two-plasmon decay instability needs to be confirmed in experiments which measure several instability signatures simultaneously, and which produce more quantitative information about the local density and temperature profiles than we have today

Scaling of laser-plasma interactions with laser wavelength and plasma size

Energy Technology Data Exchange (ETDEWEB)

Max, C.E.; Campbell, E.M.; Mead, W.C.; Kruer, W.L.; Phillion, D.W.; Turner, R.E.; Lasinski, B.F.; Estabrook, K.G.

1983-01-25

Plasma size is an important parameter in wavelength-scaling experiments because it determines both the threshold and potential gain for a variety of laser-plasma instabilities. Most experiments to date have of necessity produced relatively small plasmas, due to laser energy and pulse-length limitations. We have discussed in detail three recent Livermore experiments which had large enough plasmas that some instability thresholds were exceeded or approached. Our evidence for Raman scatter, filamentation, and the two-plasmon decay instability needs to be confirmed in experiments which measure several instability signatures simultaneously, and which produce more quantitative information about the local density and temperature profiles than we have today.

Modified Debye screening potential in a magnetized quantum plasma

International Nuclear Information System (INIS)

Salimullah, M.; Hussain, A.; Sara, I.; Murtaza, G.; Shah, H.A.

2009-01-01

The effects of quantum mechanical influence and uniform static magnetic field on the Shukla-Nambu-Salimullah potential in an ultracold homogeneous electron-ion Fermi plasma have been examined in detail. It is noticed that the strong quantum effect arising through the Bohm potential and the ion polarization effect can give rise to a new oscillatory behavior of the screening potential beyond the shielding cloud which could explain a new type of possible robust ordered structure formation in the quantum magnetoplasma. However, the magnetic field enhances the Debye length perpendicular to the magnetic field in the weak quantum limit of the quantum plasma.

Potential around a dust grain in collisional plasma

Energy Technology Data Exchange (ETDEWEB)

Moulick, R., E-mail: moulick@gmail.com; Goswami, K. S. [Centre of Plasma Physics - Institute for Plasma Research Sonapur, Guwahati, Assam 782402 (India)

2015-04-15

The ion neutral collision can lead to interesting phenomena in dust charging, totally different from the expectations based on the traditional orbit motion limited theory. The potential around a dust grain is investigated for the collisional plasma considering the presence of ion neutral collisions. Fluid equations are solved for the one dimensional radial coordinate. It is observed that with the gradual increase in ion neutral collision, the potential structure around the dust grain changes its shape and is different from the usual Debye-Hückel potential. The shift however starts from a certain value of ion neutral collision and the electron-ion density varies accordingly. The potential variation is interesting and reconfirms the fact that there exists a region of attraction for negative charges. The collision modeling is done for the full range of plasma, i.e., considering the bulk and the sheath jointly. The potential variation with collision is also shown explicitly and the variation is found to cope up with the earlier observations.

Magnetic field profiles during turbulent heating in a toroidal hydrogen plasma

International Nuclear Information System (INIS)

Kalfsbeek, H.W.

1978-12-01

A description is given of the measurements of both poloidal and toroidal magnetic field components as functions of radius and time in a small turbulently heated tokamak. These measurements have been carried out with an array of miniature pick-up coils, enclosed in a quartz tube which is inserted into the plasma. The electric fields inside the plasma, as well as the parallel resistivity profiles are deduced from the measured magnetic fields. The ohmically dissipated energy is determined from the field distributions and compared with the total input energy. The experimental results are compared with the outcome of a numerical model. The consistency with information obtained from other diagnostic measurements is checked. (Auth.)

Floating potential and sheath thickness for cylindrical and spherical probes in electronegative plasmas

International Nuclear Information System (INIS)

Morales Crespo, R.; Fernandez Palop, J.I.; Hernandez, M.A.; Borrego del Pino, S.; Diaz-Cabrera, J.M.; Ballesteros, J.

2006-01-01

In this paper, the floating potential, for cylindrical and spherical Langmuir probes immersed into an electronegative plasma, is determined by using a radial model described in a previous paper. This floating potential is determined for several probe radius values and ranks of plasma electronegativity, from almost electropositive plasmas to high electronegative plasmas. The thickness of the positive ion sheath is also determined for this kind of probes in electronegative plasmas, as well as the analytical expressions fitting this thickness, showing its dependence on the probe radius and electric potential

Potential formation in the plasma confinement region of a radio-frequency plugged linear device

International Nuclear Information System (INIS)

Fujita, Hideki; Kumazawa, Ryuhei; Howald, A.M.; Okamura, Shoichi; Sato, Teruyuki; Adati, Keizo; Garner, H.R.; Nishimura, Kiyohiko.

1987-08-01

Plasma potential formation in an open-ended plasma confinement system with RF plugging (the RFC-XX-M device) is investigated. The plasma potential in the central confinement region is measured with a heavy ion beam probe system and potentials at the RF plug section are measured with multi-grid energy analyzers. The measured plasma potential is compared with that deduced from the generalized Pastukhov formula. Results show that the plasma potential develops as an ambipolar potential to equate ion and electron end losses. During RF plugging, electrons are heated by Landau damping, while ions are not heated since adiabatic conditions apply during ion plugging in this experiment. (author)

Optimization and control of the plasma shape and current profile in noncircular cross-section tokamaks

International Nuclear Information System (INIS)

Moore, R.W.; Bernard, L.C.; Chan, V.S.; Davidson, R.H.; Dobrott, D.R.; Helton, F.J.; Miller, R.L.; Pfeiffer, W.; Waltz, R.E.; Wang, T.S.

1980-06-01

High-β equilibria which are stable to all ideal MHD modes are found by optimizing the plasma shape and current profile for doublets, up-down asymmetric dees, and symmetric dees. The ideal MHD stability of these equilibria for low toroidal mode number n is analyzed with a global MHD stability code, GATO. The stability to high-n modes is analyzed with a localized ballooning code, BLOON. The attainment of high β is facilitated by an automated optimization search on shape and current parameters. The equilibria are calculated with a free-boundary equilibrium code using coils appropriate for the Doublet III experimental device. The optimal equilibria are characterized by broad current profiles with values of β/sub poloidal/ approx. =1. Experimental realization of the shapes and current profiles giving the highest β limits is explored with a 1 1/2-D transport code, which simulates the time evolution of the 2-D MHD equilibrium while calculating consistent current profiles from a 1-D transport model. Transport simulations indicate that nearly optimal shapes may be obtained provided that the currents in the field-shaping coils are appropriately programmed and the plasma current profile is sufficiently broad. Obtaining broad current profiles is possible by current ramping, neutral beam heating, and electron cyclotron heating. With combinations of these techniques it is possible to approach the optimum β predicted by the MHD theory

Ionization-potential depression and dynamical structure factor in dense plasmas

Science.gov (United States)

Lin, Chengliang; Röpke, Gerd; Kraeft, Wolf-Dietrich; Reinholz, Heidi

2017-07-01

The properties of a bound electron system immersed in a plasma environment are strongly modified by the surrounding plasma. The modification of an essential quantity, the ionization energy, is described by the electronic and ionic self-energies, including dynamical screening within the framework of the quantum statistical theory. Introducing the ionic dynamical structure factor as the indicator for the ionic microfield, we demonstrate that ionic correlations and fluctuations play a critical role in determining the ionization potential depression. This is, in particular, true for mixtures of different ions with large mass and charge asymmetry. The ionization potential depression is calculated for dense aluminum plasmas as well as for a CH plasma and compared to the experimental data and more phenomenological approaches used so far.

Direct measurements of the plasma potential by katsumata-type probes

Czech Academy of Sciences Publication Activity Database

Schrittwieser, R.; Ionita, C.; Adámek, Jiří; Stöckel, Jan; Brotánková, Jana; Martines, E.; Popa, G.; Costin, C.; van de Peppel, L.; Van Oost, G.

2006-01-01

Roč. 56, 8 suppl.B (2006), s. 145-150 ISSN 0011-4626. [Symposium on Plasma Physics and Technology /22nd./. Praha, 26.6.2006-29.6.2006] R&D Projects: GA AV ČR(CZ) KJB100430601 Institutional research plan: CEZ:AV0Z20430508 Keywords : toroidal plasma system * tokamak * probe diagnostics * plasma potential Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

Plasma equilibrium profiles with applied resonant fields on TBR-1 tokamak

International Nuclear Information System (INIS)

Castro, R.M. de; Heller, M.V.A.P.; Caldas, I.L.; Silva, R.P. da; Brasilio, Z.A.; Oda, G.A.

1995-01-01

In this work we present the measurements of the plasma potential, in the edge and in the scrape-off layer regions of plasma, with and without the presence of the magnetic field perturbations produced by resonant helical windings. (author). 6 refs., 6 figs

Changes in plasma osmolality and anion gap: potential predictors of ...

African Journals Online (AJOL)

Changes in plasma osmolality and anion gap: potential predictors of ... PROMOTING ACCESS TO AFRICAN RESEARCH ... Objective: To determine the relationship of mortality to plasma osmolality and anion gap inpatients on haemodialysis.

Use of NMR metabolomic plasma profiling methodologies to identify illicit growth-promoting administrations

NARCIS (Netherlands)

Graham, S.F.; Ruiz Aracama, A.; Lommen, A.; Cannizzo, F.T.; Biolatti, B.; Elliott, C.T.; Mooney, M.H.

2012-01-01

Detection of growth-promoter use in animal production systems still proves to be an analytical challenge despite years of activity in the field. This study reports on the capability of NMR metabolomic profiling techniques to discriminate between plasma samples obtained from cattle treated with

Muzzle voltage and contact potential in plasma armature railguns

International Nuclear Information System (INIS)

Keefer, D.

1988-01-01

The voltages measured at the muzzle of a railgun have values greater than those calculated from the one-dimensional models for railgun plasma armatures. This excess voltage is attributed to the contact potential and has a value of several tens of volts. The use of experimentally measured muzzle voltage to determine plasma properties has required that this contact potential be subtracted in order to obtain meaningful results. A two-dimensional model of the plasma armature has been analyzed which shows that a portion of this excess voltage arises as a result of the reduced conductivity in the thermal boundary layer of the rail. Another portion arises from the speed voltage and is confined to a region near the rails within the velocity boundary layer thickness. The voltage drop in the boundary layer is not constant along the length of the armature, and the implications of this effect of the boundary conditions for one- and two-dimensional models of the railgun plasma armature are discussed

Mineral profiling of ostrich (Struthio camelus) seminal plasma and its relationship with semen traits and collection day.

Science.gov (United States)

Smith, A M J; Bonato, M; Dzama, K; Malecki, I A; Cloete, S W P

2018-06-01

Successful assisted reproduction techniques, with specific focus on in vitro semen storage for artificial insemination, are dependent on certain key elements which includes the biochemical profiling of semen. The objective of this study was to complete an ostrich seminal plasma (SP) evaluation by inductively coupled plasma mass spectrometry (ICP-MS) among seven males at different daily intervals (day 1, 3, 7, 11, 15, 19, 21, 23, 25, 26, 27, 28) for a period of 28 days during spring (August to September) for mineral profiling. The effect of collection day and male on sperm concentration, semen volume and seminal plasma volume, was explored as well as the relationships amongst these specific sperm traits and SP minerals. Variation amongst SP mineral concentrations, accounted for by the fixed effects of sperm concentration, semen volume, seminal plasma volume, collection day and male, ranged from 18% to 77%. Male had the largest effect on variation in SP minerals, namely: phosphorus (P), potassium (K), calcium (Ca), sodium (Na), boron (B), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), barium (Ba), arsenic (As) and selenium (Se). Sperm concentration instigated fluctuations of P, magnesium (Mg), B, zinc (Zn), Fe, aluminium (Al), Se, manganese (Mn) and lead (Pb). Semen volume had an effect on Na, K, B, Pb and Ba while seminal plasma volume only influenced variation in Na. There were fluctuations among collection days of specific micro minerals, Ni and Mo, with initial Ni concentrations being relatively greater and Mo at lesser concentrations. Semen volume, seminal plasma volume and sperm concentration varied amongst males. Sperm concentrations during the initial collection days, 1 and 3, were less than that for days 7 to 28. Significant variation of SP minerals and sperm characteristics among ejaculates and males suggest an association of these specific elements with sperm function and are, therefore, considered to be of potential importance to

Model etch profiles for ion energy distribution functions in an inductively coupled plasma reactor

International Nuclear Information System (INIS)

Chen, W.; Abraham-Shrauner, B.; Woodworth, J.R.

1999-01-01

Rectangular trench profiles are modeled with analytic etch rates determined from measured ion distribution functions. The pattern transfer step for this plasma etch is for trilayer lithography. Argon and chlorine angular ion energy distribution functions measured by a spherical collector ring analyzer are fit to a sum of drifting Maxwellian velocity distribution functions with anisotropic temperatures. The fit of the model ion distribution functions by a simulated annealing optimization procedure converges adequately for only two drifting Maxwellians. The etch rates are proportional to analytic expressions for the ion energy flux. Numerical computation of the etch profiles by integration of the characteristic equations for profile points and connection of the profiles points is efficient. copyright 1999 American Vacuum Society

Plasma free amino acid profiles evaluate risk of metabolic syndrome, diabetes, dyslipidemia, and hypertension in a large Asian population

OpenAIRE

Yamaguchi, Natsu; Mahbub, MH; Takahashi, Hidekazu; Hase, Ryosuke; Ishimaru, Yasutaka; Sunagawa, Hiroshi; Amano, Hiroki; Kobayashi- Miura, Mikiko; Kanda, Hideyuki; Fujita, Yasuyuki; Yamamoto, Hiroshi; Yamamoto, Mai; Kikuchi, Shinya; Ikeda, Atsuko; Takasu, Mariko

2017-01-01

Background Recently, the association of plasma free amino acid (PFAA) profile and lifestyle-related diseases has been reported. However, few studies have been reported in large Asian populations, about the usefulness of PFAAs for evaluating disease risks. We examined the ability of PFAA profiles to evaluate lifestyle-related diseases in so far the largest Asian population. Methods We examined plasma concentrations of 19 amino acids in 8589 Japanese subjects, and determined the association wit...

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

Science.gov (United States)

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

2008-09-01

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

Profiling of plasma metabolites in canine oral melanoma using gas chromatography-mass spectrometry.

Science.gov (United States)

Kawabe, Mifumi; Baba, Yuta; Tamai, Reo; Yamamoto, Ryohei; Komori, Masayuki; Mori, Takashi; Takenaka, Shigeo

2015-08-01

Malignant melanoma is one of the most common and aggressive tumors in the oral cavity of dog. The tumor has a poor prognosis, and methods for diagnosis and prediction of prognosis after treatment are required. Here, we examined metabolite profiling using gas chromatography-mass spectrometry (GC-MS) for development of a discriminant model for evaluation of prognosis. Metabolite profiles were evaluated in healthy and melanoma plasma samples using orthogonal projection to latent structure using discriminant analysis (OPLS-DA). Cases that were predicted to be healthy using the OPLS discriminant model had no advanced lesions after radiation therapy. These results indicate that metabolite profiling may be useful in diagnosis and prediction of prognosis of canine malignant melanoma.

Role of ion magnetization in formation of radial density profile in magnetically expanding plasma produced by helicon antenna

Science.gov (United States)

Yadav, Sonu; Ghosh, Soumen; Bose, Sayak; Barada, Kshitish K.; Pal, Rabindranath; Chattopadhyay, Prabal K.

2018-04-01

Experimentally, the density profile in the magnetic nozzle of a helicon antenna based plasma device is seen to be modified from being centrally peaked to that of hollow nature as the external magnetic field is increased. It occurs above a characteristic field value when the ions become magnetized in the expansion chamber. The density profile in the source chamber behind the nozzle, however, remains peaked on-axis irrespective of the magnetic field. The electron temperature there is observed to be hollow and this nature is carried to the expansion chamber along the field line. In the electron energy distribution near the off axis peak location, a high energy tail exists. Rotation of these tail electrons in the azimuthal direction due to the gradient-B drift in the expansion chamber leads to an additional off-axis ionization and forms the hollow density profile. It seems that if the ions are not magnetized, then the off-axially produced additional plasma is not confined and the density profile retains the on-axis peak nature. The present experiment successfully demonstrates how the knowledge of the ion magnetization together with tail electrons significantly contributes to the design of an efficient helicon plasma based thruster.

Metabolic profiles of pomalidomide in human plasma simulated with pharmacokinetic data in control and humanized-liver mice.

Science.gov (United States)

Shimizu, Makiko; Suemizu, Hiroshi; Mitsui, Marina; Shibata, Norio; Guengerich, F Peter; Yamazaki, Hiroshi

2017-10-01

1. Pomalidomide has been shown to be potentially teratogenic in thalidomide-sensitive animal species such as rabbits. Screening for thalidomide analogs devoid of teratogenicity/toxicity - attributable to metabolites formed by cytochrome P450 enzymes - but having immunomodulatory properties is a strategic pathway towards development of new anticancer drugs. 2. In this study, plasma concentrations of pomalidomide, its primary 5-hydroxylated metabolite, and its glucuronide conjugate(s) were investigated in control and humanized-liver mice. Following oral administration of pomalidomide (100 mg/kg), plasma concentrations of 7-hydroxypomalidomide and 5-hydroxypomalidomide glucuronide were slightly higher in humanized-liver mice than in control mice. 3. Simulations of human plasma concentrations of pomalidomide were achieved with simplified physiologically-based pharmacokinetic models in both groups of mice in accordance with reported pomalidomide concentrations after low dose administration in humans. 4. The results indicate that pharmacokinetic profiles of pomalidomide were roughly similar between control mice and humanized-liver mice and that control and humanized-liver mice mediated pomalidomide 5-hydroxylation in vivo. Introducing one aromatic amino group into thalidomide resulted in less species differences in in vivo pharmacokinetics in control and humanized-liver mice.

Proteome profiling of exosomes derived from plasma of heifers with divergent genetic merit for fertility.

Science.gov (United States)

Koh, Yong Qin; Peiris, Hassendrini N; Vaswani, Kanchan; Almughlliq, Fatema B; Meier, Susanne; Burke, Chris R; Roche, John R; Reed, Charlotte B; Arachchige, Buddhika J; Reed, Sarah; Mitchell, Murray D

2018-04-25

The current study evaluated exosomes isolated from plasma of heifers bred to have high or low fertility through developing extreme diversity in fertility breeding values, however, key animal traits (e.g., body weight, milk production, and percentage of North American genetics) remained similar between the 2 groups. The exosomes were isolated by a combined ultracentrifugation and size exclusion chromatography approach and characterized by their size distribution (nanoparticle tracking analysis), morphology (transmission electron microscopy), and presence of exosomal markers (immunoblotting). In addition, a targeted mass spectrometry approach was used to confirm the presence of 2 exosomal markers, tumor susceptibility gene 101 and flotillin 1. The number of exosomes from plasma of high fertility heifers was greater compared with low fertility heifers. Interestingly, the exosomal proteomic profile, evaluated using mass spectrometry, identified 89 and 116 proteins in the high and low fertility heifers respectively, of which 4 and 31 were unique, respectively. These include proteins associated with specific biological processes and molecular functions of fertility. Most notably, the tetratricopeptide repeat protein 41-related, glycodelin, and kelch-like protein 8 were identified in plasma exosomes unique to the low fertility heifers. These proteins are suggested to play a role in reproduction; however, the role of these proteins in dairy cow reproduction remains to be elucidated. Their identification underscores the potential for proteins within exosomes to provide information on the fertility status and physiological condition of the cow. This may potentially lead to the development of prognostic tools and interventions to improving dairy cow fertility. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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.)

Analytical calculations of the rotational transform angles in the torsatron systems with different plasma pressure profiles

International Nuclear Information System (INIS)

Kuznetsov, Yu.K.; Pinos, I.B.; Tyupa, V.I.

1999-01-01

With formulas for averaging over magnetic surfaces general analytical expressions are here deduced to determine the rotational transform angles in stellarator systems having different plasma pressure profiles

Plasma phospholipid fatty acid profiles in Korean adults with and without acute coronary syndrome

Science.gov (United States)

Background and Objectives: Acute coronary syndrome (ACS), a clinical manifestation of coronary artery disease presenting as unstable angina and/or myocardial infarction, is the third-leading cause of death in South Korea. Plasma phospholipid (PL) fatty acid profiles are considered objective biomarke...

Ion temperature profiles along a hydrogen diagnostic beam in a TORE SUPRA tokamak plasma

International Nuclear Information System (INIS)

Romannikov, A.; Petrov, Yu.; Platts, P.; Khess, V.; Khutter, T.; Farzhon, Zh.; Moro, F.

2002-01-01

By means of corpuscular diagnostics one studies temperature of ions along a diagnostic hydrogen beam. Paper presents comparison of temperature of plasma (deuterium) basic ions measures by means of the active corpuscular diagnostics with temperature of C + carbon ions along a beam. One studies behavior peculiarities of T i ion temperature profiles for TORE-SUPRA different modes, such as: formation of plane and even hollow T i profiles for ohmic modes, variation of T i profiles under operation of an ergodic diverter, difference of temperature of basic ions measured by means of the active corpuscular diagnostics from C +5 temperature. Paper offers clear explanation of these peculiarities [ru

Plasma Emission Profile Recreation using Soft X-Ray Tomography

Science.gov (United States)

Page, J. W.; Mauel, M. E.; Levesque, J. P.

2015-11-01

With sufficient views from multiple diode arrays, soft X-ray tomography is an invaluable plasma diagnostic because it is a non-perturbing method to reconstruct the emission within the interior of the plasma. In preparation for the installation of new SXR arrays in HBT-EP, we compute high-resolution tomographic reconstructions of discharges having kink-like structures that rotate nearly rigidly. By assuming a uniform angular mapping from the kink mode rotation, Δϕ ~ ωΔ t, a temporal sequence from a single 16-diode fan array represents as many as 16 x 100 independent views. We follow the procedure described by Wang and Granetz and use Bessel basis functions to take the inverse Radon transform. This transform is fit to our data using a least-squares method to estimate the internal SXR emissivity as a sum of polar functions. By varying different parameters of the transformation, we optimize the quality of our recreation of the emission profile and quantify how the reconstruction changes with the azimuthal order of the transform. Supported by U.S. DOE Grant DE-FG02-86ER53222.

Three novel tokamak plasma regimes in TFTR

International Nuclear Information System (INIS)

Furth, H.P.

1985-10-01

Aside from extending ''standard'' ohmic and neutral beam heating studies to advanced plasma parameters, TFTR has encountered a number of special plasma regimes that have the potential to shed new light on the physics of tokamak confinement and the optimal design of future D-T facilities: (1) High-powered, neutral beam heating at low plasma densities can maintain a highly reactive hot-ion population (with quasi-steady-state beam fueling and current drive) in a tokamak configuration of modest bulk-plasma confinement requirements. (2) Plasma displacement away from limiter contact lends itself to clarification of the role of edge-plasma recycling and radiation cooling within the overall pattern of tokamak heat flow. (3) Noncentral auxiliary heating (with a ''hollow'' power-deposition profile) should serve to raise the central tokamak plasma temperature without deterioration of central region confinement, thus facilitating the study of alpha-heating effects in TFTR. The experimental results of regime (3) support the theory that tokamak profile consistency is related to resistive kink stability and that the global energy confinement time is determined by transport properties of the plasma edge region

Spectroscopic studies of a high Mach-number rotating plasma flow

International Nuclear Information System (INIS)

Ando, Akira; Ashino, Masashi; Sagi, Yukiko; Inutake, Masaaki; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Tobari, Hiroyuki; Yagai, Tsuyoshi

2001-01-01

Characteristics of an axially-magnetized rotating plasma are investigated by spectroscopy in the HITOP device of Tohoku University. A He plasma flows our axially and rotates azimuthally near the muzzle region of the MPD arcjet. Flow and rotational velocities and temperature of He ions and atoms are measured by Doppler shift and broadening of the HeII (γ=468.58 nm) and HeI (γ=587.56 nm) lines. Rotational velocity increases with the increase of axially-applied magnetic field strength and discharge current. As discharge current increases and mass flow rate decreases, the plasma flow velocity increases and T i increases. Ion acoustic Mach number of the plasma flow also increases, but tends to saturate at near 1. Radial profile of space potential is calculated from the obtained rotational velocity. The potential profile in the core region is parabolic corresponding to the observed rigid-body rotation of the core plasma. (author)

Spectroscopic studies of a high Mach-number rotating plasma flow

Energy Technology Data Exchange (ETDEWEB)

Ando, Akira; Ashino, Masashi; Sagi, Yukiko; Inutake, Masaaki; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Tobari, Hiroyuki; Yagai, Tsuyoshi [Tohoku Univ., Dept. of Electrical Engineering, Sendai, Miyagi (Japan)

2001-07-01

Characteristics of an axially-magnetized rotating plasma are investigated by spectroscopy in the HITOP device of Tohoku University. A He plasma flows our axially and rotates azimuthally near the muzzle region of the MPD arcjet. Flow and rotational velocities and temperature of He ions and atoms are measured by Doppler shift and broadening of the HeII ({gamma}=468.58 nm) and HeI ({gamma}=587.56 nm) lines. Rotational velocity increases with the increase of axially-applied magnetic field strength and discharge current. As discharge current increases and mass flow rate decreases, the plasma flow velocity increases and T{sub i} increases. Ion acoustic Mach number of the plasma flow also increases, but tends to saturate at near 1. Radial profile of space potential is calculated from the obtained rotational velocity. The potential profile in the core region is parabolic corresponding to the observed rigid-body rotation of the core plasma. (author)

Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders

Science.gov (United States)

Tirouvanziam, Rabindra; Obukhanych, Tetyana V.; Laval, Julie; Aronov, Pavel A.; Libove, Robin; Banerjee, Arpita Goswami; Parker, Karen J.; O'Hara, Ruth; Herzenberg, Leonard A.; Herzenberg, Leonore A.; Hardan, Antonio Y.

2012-01-01

The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N = 27) and neuro-typically developing controls (N = 20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating…

1 μs broadband frequency sweeping reflectometry for plasma density and fluctuation profile measurements

Science.gov (United States)

Clairet, F.; Bottereau, C.; Medvedeva, A.; Molina, D.; Conway, G. D.; Silva, A.; Stroth, U.; ASDEX Upgrade Team; Tore Supra Team; Eurofusion Mst1 Team

2017-11-01

Frequency swept reflectometry has reached the symbolic value of 1 μs sweeping time; this performance has been made possible, thanks to an improved control of the ramp voltage driving the frequency source. In parallel, the memory depth of the acquisition system has been upgraded and can provide up to 200 000 signals during a plasma discharge. Additional improvements regarding the trigger delay determination of the acquisition and the voltage ramp linearity required by this ultra-fast technique have been set. While this diagnostic is traditionally dedicated to the plasma electron density profile measurement, such a fast sweeping rate can provide the study of fast plasma events and turbulence with unprecedented time and radial resolution from the edge to the core. Experimental results obtained on ASDEX Upgrade plasmas are presented to demonstrate the performances of the diagnostic.

Hollow density profile and particle transport of ECH plasmas in the low-aspect-ratio heliotron/torsatron CHS

International Nuclear Information System (INIS)

Iguchi, H.; Kubo, S.; Idei, H.

1993-01-01

Transport enhancement due to helical ripples is the main problem for a low-aspect-ratio helical system to survive as a magnetic fusion device. Optimization of the magnetic configuration has been experimentally studied for neutral beam heated plasmas in the Compact Helical System (CHS). A confinement regime compatible with the LHD scaling has been obtained by shifting the magnetic axis inward with respect to the minor axis of the helical windings. However a power balance analysis suggests that the improvement of plasma parameters has mainly been achieved by the improvement of power deposition. On the other hand, electron density profiles become peaked with the inward shifted magnetic axis in contrast to flattened profiles with the outward shifted one. A question arises: Does the magnetic structure really affect transport processes? In order to answer this question, it is most suitable to examine ECH plasmas in a low collisionality regime. In this paper we report some characteristics of the ECH plasmas in the low-aspect-ratio device CHS and discuss the effect of magnetic field ripples on transport processes. (author) 10 refs., 4 figs

Monte Carlo simulations of ionization potential depression in dense plasmas

Energy Technology Data Exchange (ETDEWEB)

Stransky, M., E-mail: stransky@fzu.cz [Department of Radiation and Chemical Physics, Institute of Physics ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic)

2016-01-15

A particle-particle grand canonical Monte Carlo model with Coulomb pair potential interaction was used to simulate modification of ionization potentials by electrostatic microfields. The Barnes-Hut tree algorithm [J. Barnes and P. Hut, Nature 324, 446 (1986)] was used to speed up calculations of electric potential. Atomic levels were approximated to be independent of the microfields as was assumed in the original paper by Ecker and Kröll [Phys. Fluids 6, 62 (1963)]; however, the available levels were limited by the corresponding mean inter-particle distance. The code was tested on hydrogen and dense aluminum plasmas. The amount of depression was up to 50% higher in the Debye-Hückel regime for hydrogen plasmas, in the high density limit, reasonable agreement was found with the Ecker-Kröll model for hydrogen plasmas and with the Stewart-Pyatt model [J. Stewart and K. Pyatt, Jr., Astrophys. J. 144, 1203 (1966)] for aluminum plasmas. Our 3D code is an improvement over the spherically symmetric simplifications of the Ecker-Kröll and Stewart-Pyatt models and is also not limited to high atomic numbers as is the underlying Thomas-Fermi model used in the Stewart-Pyatt model.

Monte Carlo simulations of ionization potential depression in dense plasmas

International Nuclear Information System (INIS)

Stransky, M.

2016-01-01

A particle-particle grand canonical Monte Carlo model with Coulomb pair potential interaction was used to simulate modification of ionization potentials by electrostatic microfields. The Barnes-Hut tree algorithm [J. Barnes and P. Hut, Nature 324, 446 (1986)] was used to speed up calculations of electric potential. Atomic levels were approximated to be independent of the microfields as was assumed in the original paper by Ecker and Kröll [Phys. Fluids 6, 62 (1963)]; however, the available levels were limited by the corresponding mean inter-particle distance. The code was tested on hydrogen and dense aluminum plasmas. The amount of depression was up to 50% higher in the Debye-Hückel regime for hydrogen plasmas, in the high density limit, reasonable agreement was found with the Ecker-Kröll model for hydrogen plasmas and with the Stewart-Pyatt model [J. Stewart and K. Pyatt, Jr., Astrophys. J. 144, 1203 (1966)] for aluminum plasmas. Our 3D code is an improvement over the spherically symmetric simplifications of the Ecker-Kröll and Stewart-Pyatt models and is also not limited to high atomic numbers as is the underlying Thomas-Fermi model used in the Stewart-Pyatt model

The Chemical Potential of Plasma Membrane Cholesterol: Implications for Cell Biology.

Science.gov (United States)

Ayuyan, Artem G; Cohen, Fredric S

2018-02-27

Cholesterol is abundant in plasma membranes and exhibits a variety of interactions throughout the membrane. Chemical potential accounts for thermodynamic consequences of molecular interactions, and quantifies the effective concentration (i.e., activity) of any substance participating in a process. We have developed, to our knowledge, the first method to measure cholesterol chemical potential in plasma membranes. This was accomplished by complexing methyl-β-cyclodextrin with cholesterol in an aqueous solution and equilibrating it with an organic solvent containing dissolved cholesterol. The chemical potential of cholesterol was thereby equalized in the two phases. Because cholesterol is dilute in the organic phase, here activity and concentration were equivalent. This equivalence allowed the amount of cholesterol bound to methyl-β-cyclodextrin to be converted to cholesterol chemical potential. Our method was used to determine the chemical potential of cholesterol in erythrocytes and in plasma membranes of nucleated cells in culture. For erythrocytes, the chemical potential did not vary when the concentration was below a critical value. Above this value, the chemical potential progressively increased with concentration. We used standard cancer lines to characterize cholesterol chemical potential in plasma membranes of nucleated cells. This chemical potential was significantly greater for highly metastatic breast cancer cells than for nonmetastatic breast cancer cells. Chemical potential depended on density of the cancer cells. A method to alter and fix the cholesterol chemical potential to any value (i.e., a cholesterol chemical potential clamp) was also developed. Cholesterol content did not change when cells were clamped for 24-48 h. It was found that the level of activation of the transcription factor STAT3 increased with increasing cholesterol chemical potential. The cholesterol chemical potential may regulate signaling pathways. Copyright © 2018. Published by

Resonant power absorption in helicon plasma sources

International Nuclear Information System (INIS)

Chen Guangye; Arefiev, Alexey V.; Bengtson, Roger D.; Breizman, Boris N.; Lee, Charles A.; Raja, Laxminarayan L.

2006-01-01

Helicon discharges produce plasmas with a density gradient across the confining magnetic field. Such plasmas can create a radial potential well for nonaxisymmetric whistlers, allowing radially localized helicon (RLH) waves. This work presents new evidence that RLH waves play a significant role in helicon plasma sources. An experimentally measured plasma density profile in an argon helicon discharge is used to calculate the rf field structure. The calculations are performed using a two-dimensional field solver under the assumption that the density profile is axisymmetric. It is found that RLH waves with an azimuthal wave number m=1 form a standing wave structure in the axial direction and that the frequency of the RLH eigenmode is close to the driving frequency of the rf antenna. The calculated resonant power absorption, associated with the RLH eigenmode, accounts for most of the rf power deposited into the plasma in the experiment

Changes in short-chain fatty acid plasma profile incurred by dietary fiber composition

DEFF Research Database (Denmark)

Knudsen, Knud Erik Bach; Jørgensen, Henry Johs. Høgh; Theil, Peter Kappel

2016-01-01

Pigs were used as model for humans to study the impact of dietary fiber (DF), the main substrate for microbial fermentation, on plasma profile of short-chain fatty acids (SCFA; acetate, propionate, and butyrate). Six female pigs fitted with catheters in the portal vein and mesenteric artery and w...... higher net absorption of butyrate (2.4–4.0 vs. 1.6 mmol/h; P ...Pigs were used as model for humans to study the impact of dietary fiber (DF), the main substrate for microbial fermentation, on plasma profile of short-chain fatty acids (SCFA; acetate, propionate, and butyrate). Six female pigs fitted with catheters in the portal vein and mesenteric artery...... >> arabinoxylan >> β-glucan, whereas in the WWG, WAF, and RAF, diets it was arabinoxylan >> cellulose > β-glucan. The diets were fed to the pigs during 3 wk in a crossover design. Within an experimental week, WFL was supplied on Days 1 through 3 and WWG, WAF, or RAF was supplied during Days 4 through 7. Fasting...

Plasma Exosome Profiling of Cancer Patients by a Next Generation Systems Biology Approach.

Science.gov (United States)

Domenyuk, Valeriy; Zhong, Zhenyu; Stark, Adam; Xiao, Nianqing; O'Neill, Heather A; Wei, Xixi; Wang, Jie; Tinder, Teresa T; Tonapi, Sonal; Duncan, Janet; Hornung, Tassilo; Hunter, Andrew; Miglarese, Mark R; Schorr, Joachim; Halbert, David D; Quackenbush, John; Poste, George; Berry, Donald A; Mayer, Günter; Famulok, Michael; Spetzler, David

2017-02-20

Technologies capable of characterizing the full breadth of cellular systems need to be able to measure millions of proteins, isoforms, and complexes simultaneously. We describe an approach that fulfils this criterion: Adaptive Dynamic Artificial Poly-ligand Targeting (ADAPT). ADAPT employs an enriched library of single-stranded oligodeoxynucleotides (ssODNs) to profile complex biological samples, thus achieving an unprecedented coverage of system-wide, native biomolecules. We used ADAPT as a highly specific profiling tool that distinguishes women with or without breast cancer based on circulating exosomes in their blood. To develop ADAPT, we enriched a library of ~10 11 ssODNs for those associating with exosomes from breast cancer patients or controls. The resulting 10 6 enriched ssODNs were then profiled against plasma from independent groups of healthy and breast cancer-positive women. ssODN-mediated affinity purification and mass spectrometry identified low-abundance exosome-associated proteins and protein complexes, some with known significance in both normal homeostasis and disease. Sequencing of the recovered ssODNs provided quantitative measures that were used to build highly accurate multi-analyte signatures for patient classification. Probing plasma from 500 subjects with a smaller subset of 2000 resynthesized ssODNs stratified healthy, breast biopsy-negative, and -positive women. An AUC of 0.73 was obtained when comparing healthy donors with biopsy-positive patients.

Time evolution of plasma potential in pulsed operation of ECRIS

International Nuclear Information System (INIS)

Tarvainen, O.; Koivisto, H.; Ropponen, T.; Toivanen, V.; Higurashi, Y.; Nakagawa, T.

2012-01-01

The time evolution of plasma potential has been measured with a retarding field analyzer in pulsed operation mode with electron cyclotron resonance ion sources at JYFL and RIKEN. Three different ion sources with microwave frequencies ranging from 6.4 to 18 GHz were employed for the experiments. The plasma potential was observed to increase 10-75 % during the Pre-glow and 10-30 % during the afterglow compared to steady state. The paper is followed by the slides of the presentation. (authors)

Theory of a spherical emissive probe in a low-density isotropic plasma

International Nuclear Information System (INIS)

Din, A.

2010-01-01

Emissive probes are widely being used by plasma experimentalists to determine plasma parameters. Here, a fairly general spherical-emissive-probe scenario based on trajectory integration of the Vlasov equation is formulated and specialized to the particular non-emissive situation considered by Bernstein and Rabinowitz (1959), which is monoenergetic isotropic ions and Boltzmann-distributed electrons originating from the plasma. Then, this formalism together with our newly developed analytic-numerical matching procedure is used for finding the potential profile in the entire plasma-probe transition (PPT) region, consisting of the 'inward' and 'outward' sheath solutions, and the quasineutral (plasma) solution. The analytically expanded outward sheath and plasma solutions, the quasineutral solution and the related matching procedure represent genuinely new results in the context of this particular non-emissive probe scenario, however with the underlying methodology also applicable to other probe scenarios in the future. For the emissive case we consider, in addition to the plasma ions and electrons of the Bernstein and Rabinowitz scenario, electrons emitted from the probe surface with zero tangential velocity and a 'waterbag' distribution with respect to the radial velocity. Using our newly developed numerical matching procedure, we calculate the entire potential profile also for this emissive case. Comparison of the potential profiles for the emissive and non-emissive cases shows visible differences, thus demonstrating the effect of electron emission from the probe. To our knowledge, the present work represents the first attempt at systematically developing a kinetic approach for spherical emissive probes. (author)

Three-dimensional modeling of a negative ion source with a magnetic filter: impact of biasing the plasma electrode on the plasma asymmetry

Science.gov (United States)

Fubiani, G.; Boeuf, J. P.

2015-10-01

The effect on the plasma characteristics of biasing positively the plasma electrode (PE) in negative ion sources with a magnetic filter is analysed using a 3D particle-in-cell model with Monte-Carlo collisions (PIC-MCC). We specialize to the one driver (i.e. one inductively coupled radio-frequency discharge) BATMAN negative ion source and the 4-drivers (large volume) ELISE device. Both are ITER prototype high power tandem-type negative ion sources developed for the neutral beam injector (NBI) system. The plasma is generated in the driver and diffuses inside the second chamber which is magnetized. Asymmetric plasma profiles originate from the formation of an electric field transverse to the electron current flowing through the magnetic filter (Hall effect). The model shows that the importance of the asymmetry increases with the PE bias potential, i.e. with the electron flow from the driver to the extraction region and depends on the shape of the magnetic filter field. We find that although the plasma density and potential profiles may be more or less asymmetric depending on the filter field configuration, the electron current to the plasma grid is always strongly asymmetric.

Three-dimensional modeling of a negative ion source with a magnetic filter: impact of biasing the plasma electrode on the plasma asymmetry

International Nuclear Information System (INIS)

Fubiani, G; Boeuf, J P

2015-01-01

The effect on the plasma characteristics of biasing positively the plasma electrode (PE) in negative ion sources with a magnetic filter is analysed using a 3D particle-in-cell model with Monte-Carlo collisions (PIC-MCC). We specialize to the one driver (i.e. one inductively coupled radio-frequency discharge) BATMAN negative ion source and the 4-drivers (large volume) ELISE device. Both are ITER prototype high power tandem-type negative ion sources developed for the neutral beam injector (NBI) system. The plasma is generated in the driver and diffuses inside the second chamber which is magnetized. Asymmetric plasma profiles originate from the formation of an electric field transverse to the electron current flowing through the magnetic filter (Hall effect). The model shows that the importance of the asymmetry increases with the PE bias potential, i.e. with the electron flow from the driver to the extraction region and depends on the shape of the magnetic filter field. We find that although the plasma density and potential profiles may be more or less asymmetric depending on the filter field configuration, the electron current to the plasma grid is always strongly asymmetric. (paper)

Growth curve analysis for plasma profiles using smoothing splines. Final report, January 1993--January 1995

International Nuclear Information System (INIS)

Imre, K.

1995-07-01

In this project, we parameterize the shape and magnitude of the temperature and density profiles on JET and the temperature profiles on TFTR. The key control variables for the profiles were tabulated and the response functions were estimated. A sophisticated statistical analysis code was developed to fit the plasma profiles. Our analysis indicate that the JET density shape depends primarily on bar n/B t for Ohmic heating, bar n for L-mode and I p for H-mode. The temperature profiles for JET are mainly determined by q 95 for the case of Ohmic heating, and by B t and P/bar n for the L-mode. For the H-mode the shape depends on the type of auxiliary heating, Z eff , N bar n, q 95 , and P

Control-oriented modeling of the plasma particle density in tokamaks and application to real-time density profile reconstruction

NARCIS (Netherlands)

Blanken, T.C.; Felici, F.; Rapson, C.J.; de Baar, M.R.; Heemels, W.P.M.H.

2018-01-01

A model-based approach to real-time reconstruction of the particle density profile in tokamak plasmas is presented, based on a dynamic state estimator. Traditionally, the density profile is reconstructed in real-time by solving an ill-conditioned inversion problem using a measurement at a single

Nonlocality of plasma fluctuations and transport in magnetically confined plasmas nonlocal plasma transport and radial structural formation

International Nuclear Information System (INIS)

Toi, Kazuo

2002-01-01

Experimental evidence and underlying physical processes of nonlocal characters and structural formation in magnetically confined toroidal plasmas are reviewed. Radial profiles of the plasmas exhibit characteristic structures, depending on the various confinement regimes. Profile stiffness subjected to some global constraint and rapid plasma responses to applied plasma perturbation result from nonlocal transport. Once the plasma is free from the constraint, the plasma state can be changed to a new state exhibiting various types of prominent structural formation such as an internal transport barrier. (author)

Formation and control of plasma potentials in TMX upgrade

Energy Technology Data Exchange (ETDEWEB)

Simonen, T.C.; Orzechowski, T.J.; Porkolab, M.; Stallard, B.W.

1981-05-06

The methods to be employed to form and control plasma potentials in the TMX Upgrade tandem mirror with thermal barriers are described. ECRH-generated mirror -confined electron plasmas are used to establish a negative potential region to isolate the end-plug and central-cell celectrons. This thermal isolation will allow a higher end-plug electron temperature and an increased central-cell confining potential. Improved axial central-cell ion confinement results since higher temperature central-cell ions can be confined. This paper describes: (1) calculations of the sensitivity of barrier formation to vacuum conditions and to the presence of impurities in the neutral beams, (2) calculations of microwave penetration and absorption used to design the ECRH system, and (3) techniques to limit electron runaway to high energies by localized microwave beams and by relativistic detuning.

Formation and control of plasma potentials in TMX upgrade

International Nuclear Information System (INIS)

Simonen, T.C.; Orzechowski, T.J.; Porkolab, M.; Stallard, B.W.

1981-01-01

The methods to be employed to form and control plasma potentials in the TMX Upgrade tandem mirror with thermal barriers are described. ECRH-generated mirror -confined electron plasmas are used to establish a negative potential region to isolate the end-plug and central-cell celectrons. This thermal isolation will allow a higher end-plug electron temperature and an increased central-cell confining potential. Improved axial central-cell ion confinement results since higher temperature central-cell ions can be confined. This paper describes: (1) calculations of the sensitivity of barrier formation to vacuum conditions and to the presence of impurities in the neutral beams, (2) calculations of microwave penetration and absorption used to design the ECRH system, and (3) techniques to limit electron runaway to high energies by localized microwave beams and by relativistic detuning

Plasma proteome profiles associated with diet-induced metabolic syndrome and the early onset of metabolic syndrome in a pig model.

Directory of Open Access Journals (Sweden)

Marinus F W te Pas

Full Text Available Obesity and related diabetes are important health threatening multifactorial metabolic diseases and it has been suggested that 25% of all diabetic patients are unaware of their patho-physiological condition. Biomarkers for monitoring and control are available, but early stage predictive biomarkers enabling prevention of these diseases are still lacking. We used the pig as a model to study metabolic disease because humans and pigs share a multitude of metabolic similarities. Diabetes was chemically induced and control and diabetic pigs were either fed a high unsaturated fat (Mediterranean diet or a high saturated fat/cholesterol/sugar (cafeteria diet. Physiological parameters related to fat metabolism and diabetes were measured. Diabetic pigs' plasma proteome profiles differed more between the two diets than control pigs plasma proteome profiles. The expression levels of several proteins correlated well with (pathophysiological parameters related to the fat metabolism (cholesterol, VLDL, LDL, NEFA and diabetes (Glucose and to the diet fed to the animals. Studying only the control pigs as a model for metabolic syndrome when fed the two diets showed correlations to the same parameters but now more focused on insulin, glucose and abdominal fat depot parameters. We conclude that proteomic profiles can be used as a biomarker to identify pigs with developing metabolic syndrome (prediabetes and diabetes when fed a cafeteria diet. It could be developed into a potential biomarkers for the early recognition of metabolic diseases.

Analysis of plasma microRNA expression profiles in male textile workers with noise-induced hearing loss.

Science.gov (United States)

Ding, Lu; Liu, Jing; Shen, Huan-Xi; Pan, Li-Ping; Liu, Qing-Dong; Zhang, Heng-Dong; Han, Lei; Shuai, Li-Guo; Ding, En-Min; Zhao, Qiu-Ni; Wang, Bo-Shen; Zhu, Bao-Li

2016-03-01

Circulating microRNAs (miRNAs) have attracted interests as non-invasive biomarkers of physiological and pathological conditions, which may be applied in noise-induced hearing loss (NIHL). However, no epidemiology studies have yet examined the potential effects of NIHL or noise exposure on miRNA expression profiles. We sought to identify permanent NIHL-related miRNAs and to predict the biological functions of the putative genes encoding the indicated miRNAs. In the discovery stage, we used a microarray assay to detect the miRNA expression profiles between pooled plasma samples from 10 noise-exposed individuals with normal hearing and 10 NIHL patients. In addition, we conducted a preliminary validation of six candidate miRNAs in the same 20 workers. Subsequently, three miRNAs were selected for expanded validation in 23 non-exposed individuals with normal hearing and 46 noise-exposed textile workers which including 23 noise-exposed workers with normal hearing and 23 NIHL patients. Moreover, we predicted the biological functions of the putative target genes using a Gene Ontology (GO) function enrichment analysis. In the discovery stage, compared with the noise exposures with normal hearing, 73 miRNAs demonstrated at least a 1.5-fold differential expression in the NIHL patients. In the preliminary validation, compared with the noise exposures, the plasma levels of miR-16-5p, miR-24-3p, miR-185-5p and miR-451a were all upregulated (P < 0.001) in the NIHL patients. In the expanded validation stage, compared with the non-exposures, the plasma levels of miR-24, miR-185-5p and miR-451a were all significantly downregulated (P < 0.001) in the exposures. And compared with the noise exposures, the plasma levels of miR-185-5p and miR-451a were slightly elevated (P < 0.001) in the NIHL patients, which were consistent with the results of preliminary validation and microarray analysis. The two indicated plasma miRNAs may be biomarkers of indicating responses to noise exposure

Plasma potential measurements in the edge region of the ISTTOK plasma, using electron emissive probes

International Nuclear Information System (INIS)

Ionita, C.; Balan, P.; Schrittwieser, R.; Cabral, J.A.; Fernandes, H.; Figueiredo, H. F.C.; Varandas, C.

2001-01-01

We have recently started to use electron-emissive probes for direct measurements of the plasma potential and its fluctuations in the edge region of the plasma ring in the tokamak ISTTOK in Lisbon, Portugal. This method is based on the fact that the electron emission current of such a probe is able to compensate electron temperature variations and electron drifts, which can occur in the edge plasma region of magnetized fusion devices, and which are making measurements with cold probes prone to errors. In this contribution we present some of the first results of our investigations in ISTTOK.(author)

Magnetic diagnostics: General principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems

International Nuclear Information System (INIS)

Pustovitov, V.D.

2001-01-01

Restrictions on magnetic diagnostics are discussed. Being related to the integral nature of the measurable quantities, these follow from the fundamental laws of electromagnetism. A series of examples demonstrating the strength of these restrictions is analysed. The general rule is emphasized that information obtained from external magnetic measurements is insufficient for reliable evaluation of plasma current and pressure profiles in tokamaks and in stellarators. The underlying reason is that outside the plasma the self-field of the equilibrium plasma currents is determined by the boundary conditions on the plasma surface alone. (author)

Neutron Profiles and Fuel Ratio nT /nD Measurements in JET ELMy H-mode Plasmas with Tritium Puff

Czech Academy of Sciences Publication Activity Database

Bonheure, G.; Popovichev, S.; Bertalot, L.; Murari, A.; Conroy, S.; Mlynář, Jan; Voitsekhovitch, I.

2006-01-01

Roč. 46, č. 7 (2006), s. 725-740 ISSN 0029-5515 Institutional research plan: CEZ:AV0Z20430508 Keywords : fusion * JET * plasma profile * tomography * neutron diagnostics * fuel * tritium transport Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.839, year: 2006

Flare plasma density determination using observed temperature profiles

International Nuclear Information System (INIS)

Garcia, H.A.

1986-01-01

Observed electron temperature variations derived from flux intensity ratios of whole-disk continuum soft X-ray spectra recorded by GOES satellites are presently subjected to an analysis that is based on the nonequilibrium energy balance equation in order to obtain the physical properties of a large solar flare from onset through the gradual phase. A self-similar formalism which reduces the nonlinear, second-order PDE in length and time to a more tractable, nonlinear, first-order Ricatti equation is invoked. Plasma density is the principal unknown variable contained in the Ricatti equation, which also contains first-order time derivatives and first- and second-order spatial derivatives of temperature. This methodology is presently applied to the moderate size flare of January 28, 1982, for which a density profile is deduced under various parametric conditions. 37 references

Analysis of Rotation and Transport Data in C-Mod ITB Plasmas

Science.gov (United States)

Fiore, C. L.; Rice, J. E.; Reinke, M. L.; Podpaly, Y.; Bespamyatnov, I. O.; Rowan, W. L.

2009-11-01

Internal transport barriers (ITBs) spontaneously form near the half radius of Alcator C-Mod plasmas when the EDA H-mode is sustained for several energy confinement times in either off-axis ICRF heated discharges or in purely ohmic heated plasmas. These plasmas exhibit strongly peaked density and pressure profiles, static or peaking temperature profiles, peaking impurity density profiles, and thermal transport coefficients that approach neoclassical values in the core. It has long been observed that the intrinsic central plasma rotation that is strongly co-current following the H-mode transition slows and often reverses as the density peaks as the ITB forms. Recent spatial measurements demonstrate that the rotation profile develops a well in the core region that decreases continuously as central density rises while the value outside of the core remains strongly co-current. This results in the formation of a steep potential gradient/strong electric field at the location of the foot of the ITB density profile. The resulting E X B shearing rate is also quite significant at the foot. These analyses and the implications for plasma transport and stability will be presented.

Profiling plasma extracellular vesicle by pluronic block-copolymer based enrichment method unveils features associated with breast cancer aggression, metastasis and invasion.

Science.gov (United States)

Zhong, Zhenyu; Rosenow, Matthew; Xiao, Nick; Spetzler, David

2018-01-01

Extracellular vesicle (EV)-based liquid biopsies have been proposed to be a readily obtainable biological substrate recently for both profiling and diagnostics purposes. Development of a fast and reliable preparation protocol to enrich such small particles could accelerate the discovery of informative, disease-related biomarkers. Though multiple EV enrichment protocols are available, in terms of efficiency, reproducibility and simplicity, precipitation-based methods are most amenable to studies with large numbers of subjects. However, the selectivity of the precipitation becomes critical. Here, we present a simple plasma EV enrichment protocol based on pluronic block copolymer. The enriched plasma EV was able to be verified by multiple platforms. Our results showed that the particles enriched from plasma by the copolymer were EV size vesicles with membrane structure; proteomic profiling showed that EV-related proteins were significantly enriched, while high-abundant plasma proteins were significantly reduced in comparison to other precipitation-based enrichment methods. Next-generation sequencing confirmed the existence of various RNA species that have been observed in EVs from previous studies. Small RNA sequencing showed enriched species compared to the corresponding plasma. Moreover, plasma EVs enriched from 20 advanced breast cancer patients and 20 age-matched non-cancer controls were profiled by semi-quantitative mass spectrometry. Protein features were further screened by EV proteomic profiles generated from four breast cancer cell lines, and then selected in cross-validation models. A total of 60 protein features that highly contributed in model prediction were identified. Interestingly, a large portion of these features were associated with breast cancer aggression, metastasis as well as invasion, consistent with the advanced clinical stage of the patients. In summary, we have developed a plasma EV enrichment method with improved precipitation selectivity

Effect of magnetic boundary on edge plasma profiles studied using probe measurements in EXTRAP T2R

OpenAIRE

Moustaphawi, Hawra

2012-01-01

In this Master’s thesis project, several experiments are conducted under three different conditions in order to study their effect on the edge plasma profiles. In the first case, the standard case, there is no external interference and the plasma is studied under normal lab environments. In the second case, the plasma position inside the EXTRAP T2R device is changed by a few millimeters and in the third case a magnetic boundary is inserted into the experiment. For each set of the experiment, ...

Relaxation of plasma potential and poloidal flows in the boundary of tokamak plasmas

International Nuclear Information System (INIS)

Hron, M.; Duran, I.; Stoeckel, J.; Hidalgo, C.; Gunn, J.

2003-01-01

The relaxation times of plasma parameters after a sudden change of electrode voltage have been measured in the plasma boundary during polarization experiments on the CASTOR tokamak (R = 0.4 m, a = 75 mm, B t = 1 T, I p ∼ 9 kA, q a ∼ 10). The time evolution of the floating potential after the biasing voltage switch-off can be well fitted by an exponential decay with characteristic time in the range of 10 - 20 μs. The poloidal flow shows a transient behaviour with a time scale of about 10 - 30 μs. These time scales are smaller than the expected damping time based on neoclassical parallel viscosity (which is in the range of 100 νs) and atomic physics via charge exchange (in the range of 100 - 1000 νs). But, they are larger than the correlation time of plasma turbulence (about 5 μs). These findings suggest that anomalous damping rate mechanisms for radial electric fields and poloidal flows may play a role in the boundary of tokamak plasmas. (authors)

Plasma profile and shape optimization for the advanced tokamak power plant, ARIES-AT

International Nuclear Information System (INIS)

Kessel, C.E.; Mau, T.K.; Jardin, S.C.; Najmabadi, F.

2006-01-01

An advanced tokamak plasma configuration is developed based on equilibrium, ideal MHD stability, bootstrap current analysis, vertical stability and control, and poloidal field coil analysis. The plasma boundaries used in the analysis are forced to coincide with the 99% flux surface from the free-boundary equilibrium. Using an accurate bootstrap current model and external current drive profiles from ray tracing calculations in combination with optimized pressure profiles, β N values above 7.0 have been obtained. The minimum current drive requirement is found to lie at a lower β N of 6.0. The external kink mode is stabilized by a tungsten shell located at 0.33 times the minor radius and a feedback system. Plasma shape optimization has led to an elongation of 2.2 and triangularity of 0.9 at the separatrix. Vertical stability could be achieved by a combination of tungsten shells located at 0.33 times the minor radius and feedback control coils located behind the shield. The poloidal field coils were optimized in location and current, providing a maximum coil current of 8.6 MA. These developments have led to a simultaneous reduction in the power plant major radius and toroidal field from those found in a previous study [S.C. Jardin, C.E. Kessel, C.G. Bathke, D.A. Ehst, T.K. Mau, F. Najmabadi, T.W. Petrie, the ARIES Team, Physics basis for a reversed shear tokamak power plant, Fusion Eng. Design 38 (1997) 27

Emission spectra from super-critical rippled plasma density profiles illuminated by intense laser pulses

International Nuclear Information System (INIS)

Ondarza R, R.; Boyd, T.J.M.

2000-01-01

High-order harmonic emission from the interaction of intense femtosecond laser pulses with super-critical plasmas characterized by a rippled density profile at the vacuum-plasma interface has been observed from particle-in-cell (PIC) simulations. A plasma simulation box several laser wavelengths in extent was prepared with a rippled density of a fraction of a laser wavelength. Emission spectra at the very initial stage of the interaction were recorded with spectral characteristics dissimilar to those previously reported in the literature. The reflected light spectra were characterized by a strong emission at the plasma line and by a series of harmonics at multiples of the ripple frequency. Harmonic spectra were obtained for different values of the plasma ripple frequency. In all cases the harmonics were emitted at the precise multiple harmonic number of the ripple frequency. Another important feature apparent from the simulations was that the emission peaks appeared to havea complex structure as compared with those for unrippled plasmas. For the cases when the plasma was rippled the peaks that corresponded to the multiples of the rippled density typically showed a double peak for the first few harmonics. The reflected emission plots for the main laser pulse showed strong emission at the plasma frequency and at multiples of that frequency as reported by the authors in the literature. (Author)

Effective potential kinetic theory for strongly coupled plasmas

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2016-11-01

The effective potential theory (EPT) is a recently proposed method for extending traditional plasma kinetic and transport theory into the strongly coupled regime. Validation from experiments and molecular dynamics simulations have shown it to be accurate up to the onset of liquid-like correlation parameters (corresponding to Γ ≃ 10-50 for the one-component plasma, depending on the process of interest). Here, this theory is briefly reviewed along with comparisons between the theory and molecular dynamics simulations for self-diffusivity and viscosity of the one-component plasma. A number of new results are also provided, including calculations of friction coefficients, energy exchange rates, stopping power, and mobility. The theory is also cast in the Landau and Fokker-Planck kinetic forms, which may prove useful for enabling efficient kinetic computations.

Comparison of hollow cathode discharge plasma configurations

International Nuclear Information System (INIS)

Farnell, Casey C; Farnell, Cody C; Williams, John D

2011-01-01

Hollow cathodes used in plasma contactor and electric propulsion devices provide electrons for sustaining plasma discharges and enabling plasma bridge neutralization. Life tests show erosion on hollow cathodes exposed to the plasma environment produced in the region downstream of these devices. To explain the observed erosion, plasma flow field measurements are presented for hollow cathode generated plasmas using both directly immersed probes and remotely located plasma diagnostics. Measurements on two cathode discharge configurations are presented: (1) an open, no magnetic field configuration and (2) a setup simulating the discharge chamber environment of an ion thruster. In the open cathode configuration, large amplitude plasma potential oscillations, ranging from 20 to 85 V within a 34 V discharge, were observed using a fast response emissive probe. These oscillations were observed over a dc potential profile that included a well-defined potential hill structure. A remotely located electrostatic analyzer (ESA) was used to measure the energy of ions produced within the plasma, and energies were detected that met, and in some cases exceeded, the peak oscillatory plasma potentials detected by the emissive probe. In the ion thruster discharge chamber configuration, plasma potentials from the emissive probe again agreed with ion energies recorded by the remotely located ESA; however, much lower ion energies were detected compared with the open configuration. A simplified ion-transit model that uses temporal and spatial plasma property measurements is presented and used to predict far-field plasma streaming properties. Comparisons between the model and remote measurements are presented.

Angular filter refractometry analysis using simulated annealing [An improved method for characterizing plasma density profiles using angular filter refractometry

International Nuclear Information System (INIS)

Angland, P.; Haberberger, D.; Ivancic, S. T.; Froula, D. H.

2017-01-01

Here, a new method of analysis for angular filter refractometry images was developed to characterize laser-produced, long-scale-length plasmas using an annealing algorithm to iterative converge upon a solution. Angular filter refractometry (AFR) is a novel technique used to characterize the density pro files of laser-produced, long-scale-length plasmas. A synthetic AFR image is constructed by a user-defined density profile described by eight parameters, and the algorithm systematically alters the parameters until the comparison is optimized. The optimization and statistical uncertainty calculation is based on a minimization of the χ2 test statistic. The algorithm was successfully applied to experimental data of plasma expanding from a flat, laser-irradiated target, resulting in average uncertainty in the density profile of 5-10% in the region of interest.

Potential formation and confinement in high density plasma on the GAMMA 10 tandem mirror

International Nuclear Information System (INIS)

Yatsu, K.

2002-01-01

After the attainment of doubling of the density due to the potential confinement, GAMMA 10 experiments have been directed to realization of a high density plasma and also to study dependence of the confining potential and confinement time on the plasma density. These problems are important to understand the physics of potential formation in tandem mirrors and also for the development of a tandem mirror reactor. We reported high density plasma production by using an ion cyclotron range of frequency heating at a high harmonic frequency in the last IAEA Conference. However, the diamagnetic signal of the high density plasma decreased when electron cyclotron resonance heating (ECRH) was applied due to some instabilities. Recently, the high density plasma production was much improved by adjusting the spacing of the conducting plates installed in the anchor transition regions, which enabled us to produce a high density plasma without degradation of the diamagnetic signal with ECRH and also to study the density dependence. In this paper we report production of a high density plasma and dependence of the confining potential and the confinement time on the density. (author)

Plasma amino acid profiles are associated with insulin, C-peptide and adiponectin levels in type 2 diabetic patients

OpenAIRE

Nakamura, H; Jinzu, H; Nagao, K; Noguchi, Y; Shimba, N; Miyano, H; Watanabe, T; Iseki, K

2014-01-01

Objectives: Plasma-free amino acid (PFAA) profiles have been associated with a future risk of developing diabetes or cardiovascular disease in nondiabetic subjects. These PFAA alterations might predominantly result from the metabolic shift caused by insulin resistance and visceral fat deposition. The variety of PFAA profiles within diabetic subjects is not well researched. In this study, we focused on type 2 diabetic subjects and examined the association between PFAA profiles and insulin- and...

New applications of Equinox code for real-time plasma equilibrium and profile reconstruction for tokamaks

International Nuclear Information System (INIS)

Bosak, K.; Blum, J.; Joffrin, E.

2004-01-01

Recent development of real-time equilibrium code Equinox using a fixed-point algorithm allow major plasma magnetic parameters to be identified in real-time, using rigorous analytical method. The code relies on the boundary flux code providing magnetic flux values on the first wall of vacuum vessel. By means of least-square minimization of differences between magnetic field obtained from previous solution and the next measurements the code identifies the source term of the non-linear Grad-Shafranov equation. The strict use of analytical equations together with a flexible algorithm offers an opportunity to include new measurements into stable magnetic equilibrium code and compare the results directly between several tokamaks while maintaining the same physical model (i.e. no iron model is necessary inside the equilibrium code). The successful implementation of this equilibrium code for JET and Tore Supra has already been published. In this paper, we show the preliminary results of predictive runs of the Equinox code using the ITER geometry. Because the real-time control experiments of plasma profile at JET using the code has been shown unstable when using magnetic and polarimetric measurements (that could be indirectly translated into accuracy vs robustness tradeoff), we plan an outline of the algorithm that will allow us to further constrain the plasma current profile using the central value of pressure of the plasma in real-time in order to better define the poloidal beta (this constraint is not necessary with purely magnetic equilibrium). (authors)

New applications of Equinox code for real-time plasma equilibrium and profile reconstruction for tokamaks

Energy Technology Data Exchange (ETDEWEB)

Bosak, K.; Blum, J. [Universite de Nice-Sophia-Antipolis, Lab. J. A. Dieudonne, 06 - Nice (France); Joffrin, E. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

2004-07-01

Recent development of real-time equilibrium code Equinox using a fixed-point algorithm allow major plasma magnetic parameters to be identified in real-time, using rigorous analytical method. The code relies on the boundary flux code providing magnetic flux values on the first wall of vacuum vessel. By means of least-square minimization of differences between magnetic field obtained from previous solution and the next measurements the code identifies the source term of the non-linear Grad-Shafranov equation. The strict use of analytical equations together with a flexible algorithm offers an opportunity to include new measurements into stable magnetic equilibrium code and compare the results directly between several tokamaks while maintaining the same physical model (i.e. no iron model is necessary inside the equilibrium code). The successful implementation of this equilibrium code for JET and Tore Supra has already been published. In this paper, we show the preliminary results of predictive runs of the Equinox code using the ITER geometry. Because the real-time control experiments of plasma profile at JET using the code has been shown unstable when using magnetic and polarimetric measurements (that could be indirectly translated into accuracy vs robustness tradeoff), we plan an outline of the algorithm that will allow us to further constrain the plasma current profile using the central value of pressure of the plasma in real-time in order to better define the poloidal beta (this constraint is not necessary with purely magnetic equilibrium). (authors)

Affinity proteomic profiling of plasma for proteins associated to area-based mammographic breast density.

Science.gov (United States)

Byström, Sanna; Eklund, Martin; Hong, Mun-Gwan; Fredolini, Claudia; Eriksson, Mikael; Czene, Kamila; Hall, Per; Schwenk, Jochen M; Gabrielson, Marike

2018-02-14

Mammographic breast density is one of the strongest risk factors for breast cancer, but molecular understanding of how breast density relates to cancer risk is less complete. Studies of proteins in blood plasma, possibly associated with mammographic density, are well-suited as these allow large-scale analyses and might shed light on the association between breast cancer and breast density. Plasma samples from 1329 women in the Swedish KARMA project, without prior history of breast cancer, were profiled with antibody suspension bead array (SBA) assays. Two sample sets comprising 729 and 600 women were screened by two different SBAs targeting a total number of 357 proteins. Protein targets were selected through searching the literature, for either being related to breast cancer or for being linked to the extracellular matrix. Association between proteins and absolute area-based breast density (AD) was assessed by quantile regression, adjusting for age and body mass index (BMI). Plasma profiling revealed linear association between 20 proteins and AD, concordant in the two sets of samples (p density and processes of tissue homeostasis, DNA repair, cancer development and/or progression in breast cancer. Further validation and follow-up studies of the shortlisted protein candidates in independent cohorts will be needed to infer their role in breast density and its progression in premenopausal and postmenopausal women.

Magnetic diagnostics: general principles and the problem of reconstruction of plasma current and pressure profiles in toroidal systems

Energy Technology Data Exchange (ETDEWEB)

Pustovitov, V.D.

2000-04-01

The restrictions of the magnetic diagnostics are discussed. Being related to the integral nature of the measurable quantities, they follow from the fundamental laws of electromagnetism. A series of particular examples demonstrating the strength of these restrictions is given and analyzed. A general rule is emphasized that the information obtained from external magnetic measurements is obviously insufficient for the reliable evaluation of plasma current and pressure profiles in tokamaks or in stellarators. The underlying reason is that outside the plasma the own field of the equilibrium plasma currents is determined by the boundary conditions on the plasma surface only. (author)

Laser-heated emissive plasma probe.

Science.gov (United States)

Schrittwieser, Roman; Ionita, Codrina; Balan, Petru; Gstrein, Ramona; Grulke, Olaf; Windisch, Thomas; Brandt, Christian; Klinger, Thomas; Madani, Ramin; Amarandei, George; Sarma, Arun K

2008-08-01

Emissive probes are standard tools in laboratory plasmas for the direct determination of the plasma potential. Usually they consist of a loop of refractory wire heated by an electric current until sufficient electron emission. Recently emissive probes were used also for measuring the radial fluctuation-induced particle flux and other essential parameters of edge turbulence in magnetized toroidal hot plasmas [R. Schrittwieser et al., Plasma Phys. Controlled Fusion 50, 055004 (2008)]. We have developed and investigated various types of emissive probes, which were heated by a focused infrared laser beam. Such a probe has several advantages: higher probe temperature without evaporation or melting and thus higher emissivity and longer lifetime, no deformation of the probe in a magnetic field, no potential drop along the probe wire, and faster time response. The probes are heated by an infrared diode laser with 808 nm wavelength and an output power up to 50 W. One probe was mounted together with the lens system on a radially movable probe shaft, and radial profiles of the plasma potential and of its oscillations were measured in a linear helicon discharge.

Laser-heated emissive plasma probe

International Nuclear Information System (INIS)

Schrittwieser, Roman; Ionita, Codrina; Balan, Petru; Gstrein, Ramona; Grulke, Olaf; Windisch, Thomas; Brandt, Christian; Klinger, Thomas; Madani, Ramin; Amarandei, George; Sarma, Arun K.

2008-01-01

Emissive probes are standard tools in laboratory plasmas for the direct determination of the plasma potential. Usually they consist of a loop of refractory wire heated by an electric current until sufficient electron emission. Recently emissive probes were used also for measuring the radial fluctuation-induced particle flux and other essential parameters of edge turbulence in magnetized toroidal hot plasmas [R. Schrittwieser et al., Plasma Phys. Controlled Fusion 50, 055004 (2008)]. We have developed and investigated various types of emissive probes, which were heated by a focused infrared laser beam. Such a probe has several advantages: higher probe temperature without evaporation or melting and thus higher emissivity and longer lifetime, no deformation of the probe in a magnetic field, no potential drop along the probe wire, and faster time response. The probes are heated by an infrared diode laser with 808 nm wavelength and an output power up to 50 W. One probe was mounted together with the lens system on a radially movable probe shaft, and radial profiles of the plasma potential and of its oscillations were measured in a linear helicon discharge

Laser-heated emissive plasma probe

Science.gov (United States)

Schrittwieser, Roman; Ionita, Codrina; Balan, Petru; Gstrein, Ramona; Grulke, Olaf; Windisch, Thomas; Brandt, Christian; Klinger, Thomas; Madani, Ramin; Amarandei, George; Sarma, Arun K.

2008-08-01

Emissive probes are standard tools in laboratory plasmas for the direct determination of the plasma potential. Usually they consist of a loop of refractory wire heated by an electric current until sufficient electron emission. Recently emissive probes were used also for measuring the radial fluctuation-induced particle flux and other essential parameters of edge turbulence in magnetized toroidal hot plasmas [R. Schrittwieser et al., Plasma Phys. Controlled Fusion 50, 055004 (2008)]. We have developed and investigated various types of emissive probes, which were heated by a focused infrared laser beam. Such a probe has several advantages: higher probe temperature without evaporation or melting and thus higher emissivity and longer lifetime, no deformation of the probe in a magnetic field, no potential drop along the probe wire, and faster time response. The probes are heated by an infrared diode laser with 808nm wavelength and an output power up to 50W. One probe was mounted together with the lens system on a radially movable probe shaft, and radial profiles of the plasma potential and of its oscillations were measured in a linear helicon discharge.

Plasma confinement using biased electrode in the TCABR tokamak

International Nuclear Information System (INIS)

Nascimento, I.C.; Kuznetsov, Y.K.; Severo, J.H.F.; Fonseca, A.M.M.; Elfimov, A.; Bellintani, V.; Heller, M.V.A.P.; Galvao, R.M.O.; Sanada, E.K.; Elizondo, J.I.; Machida, M.

2005-01-01

Experimental data obtained on the TCABR tokamak (R = 0.61 m, r = 0.18 m) with an electrally polarized electrode, placed at r = 0.16 m, is reported in this paper. The experiment was performed with plasma current of 90 kA (q 3.1), and hydrogen gas injection adjusted for keeping the electron density at 1.0x10(19) m(-3) without bias. Temporal and radial profiles of plasma parameters with and without bias were measured. The comparison of the profiles shows an increase of the density, up to a maximum factor of 2.6, while H-alpha hydrogen spectral line intensity decreases, and the CIII impurity stays on the same level. The analysis of temporal and radial profiles of plasma parameters indicates that the confined plasma entered in the H-mode regime. The data analysis shows a maximum enhanced confinement factor of 1.95, decaying to 1.5 at the maximum of the density, in comparison with predicted Neo-Alcator scaling law values. Indications of transient increase of the density gradient near the plasma edge were obtained with measurements of density profiles. Calculations of turbulence and transport at the plasma edge, using measured floating potentials and ion saturation currents, show strong decrease in the power spectra and transport. Bifurcation was not observed, and the decrease in the saturation current occurs in 50 microseconds. (author)

Potential drops supported by ion density cavities in the dynamic response of a plasma diode to an applied field

International Nuclear Information System (INIS)

Bohm, M.; Torven, S.

1990-06-01

Experiments have shown that an applied voltage drop may either be supported by a cathode sheath or by a quasi-linear variation over the plasma lasting for several electron transit times. In the latter case an ion density cavity existed initially. An analytical model and numerical simulations are used to show that a cavity gives rise to a quasi-linear potential variation for applied voltage drops below a certain critical value. For larger values the drop concentrates to a cathode sheath. The quasi-linear profile steepens to a double layer for large cavity depths. (authors)

Optical properties of dense plasmas

International Nuclear Information System (INIS)

Guenther, S.

1996-05-01

The following topics were dealt with: Stellar spectra and stellar atmospheres, spectrocopic methods in the plasma diagnostic, Green function method, influence of charged plasma particles on the line profile, Storer-Strahler interaction, dynamic screening effects, line profile shift and asymmetry, collective plasma excitations, ion dynamic effects on line profiles

Time resolved measurements of plasma potential across an anode double layer

International Nuclear Information System (INIS)

Pohoata, V.; Popa, Gh.; Schrittwieser, R.; Ionita, Codrina

2002-01-01

Experimental results are presented on self-sustained oscillations produced by the dynamics of an anode double layer or fireball in a DP-machine. By additional ionisation processes the fireball is formed in front of an additional small plane anode inserted in the diffusive plasma. An annular (ring) electrode surrounds the anode. The thickness of the ion sheath in front of this ring affects the anode current by controlling its effective diameter during the fireball oscillations. The ring potential controls first the oscillation frequency of the anode current, but also other characteristics of the instability. The ring potential was chosen as a pulsed one so that only single anode double layer instability can be excited. The ring signal was used for triggering the data acquisition system. The spatial distribution of the plasma potential in front of the anode is presented as a time resolved measurement one. A negative drop potential was found that controls the charge flux particle across the double layer. Also the plasma density inside the fireball relaxes during the disrupting time controlled by ambipolar diffusion and also by the negative potential drop. (authors)

Density and potential measurements in an intense ion-beam-generated plasma

International Nuclear Information System (INIS)

Abt, N.E.

1982-05-01

Neutral beams are created by intense large area ion beams which are neutralized in a gas cell. The interaction of the beam with the gas cell creates a plasma. Such a plasma is studied here. The basic plasma parameters, electron temperature, density, and plasma potential, are measured as a function of beam current and neutral gas pressure. These measurements are compared to a model based on the solution of Poisson's equation. Because of the cylindrical geometry the equation cannot be solved analytically. Details of the numerical method are presented

Holographic quark–antiquark potential in hot, anisotropic Yang–Mills plasma

International Nuclear Information System (INIS)

Chakraborty, Somdeb; Haque, Najmul

2013-01-01

Using the gauge/gravity duality we calculate the heavy quark–antiquark potential in a hot, anisotropic and strongly coupled Yang–Mills plasma in (3+1)-dimensions. As the anisotropic medium we take a deformed version of N=4 super Yang–Mills theory at finite temperature following a recent work where the dual type IIB supergravity solution is also proposed. We turn on a small value of the anisotropy parameter, for which the gravity dual is known analytically (perturbatively), and compute the velocity-dependent quark–antiquark interaction potential when the pair is moving through the plasma with a velocity v. By setting v=0 we recover the static quark–antiquark potential. We numerically study how the potential is modified in the presence of anisotropy. We further show numerically how the quark–antiquark separation (both in the static and the velocity-dependent case) and hence, the screening length gets modified by anisotropy. We discuss various cases depending upon the direction of the dipole and the direction of its propagation and make a comparative study of these cases. We are also able to obtain an analytical expression for the screening length of the dipole moving in a hot, anisotropic plasma in a special case

Potential Formation in Front of an Electron Emitting Electrode in a Two-Electron Temperature Plasma

International Nuclear Information System (INIS)

Gyergyek, T.; Cercek, M.; Erzen, D.

2003-01-01

Plasma potential formation in the pre-sheath region of a floating electron emitting electrode (collector) is studied theoretically in a two-electron-temperature plasma using a static kinetic plasma-sheath model. Dependence of the collector floating potential, the plasma potential in the pre-sheath region, and the critical emission coefficient on the hot electron density and temperature is calculated. It is found that for high hot to cool electron temperature ratio a double layer like solutions exist in a certain range of hot to cool electron densities

A current profile model for magnetic analysis of the start-up phase of toroidal plasmas driven by electron cyclotron heating and current drive

International Nuclear Information System (INIS)

Yoshinaga, T.; Uchida, M.; Tanaka, H.; Maekawa, T.

2007-01-01

An estimation model of plasma current density distribution for the start-up phase of toroidal plasmas generated by electron cyclotron heating (ECH) in the low aspect ratio torus experiment device is presented. The model assumes a power law parabolic current profile having seven fitting parameters. Its position, extent and broadness (or steepness) are fitted by adjusting these parameters to the observed magnetic flux signals. The adequacy of the model has been examined and confirmed by comparisons of the reconstructed current profiles and the resultant poloidal flux surfaces with the plasma images at visible light range at various stages of start-up discharges, including both the initial open field phase, the subsequent closed field phase, the current decay phase after ECH is turned off and also by a current-profile limiting experiment. This method may be useful for the study of non-inductive start-up experiments by ECH, where there is no appropriate MHD constraint on the current distribution as that in the full tokamak discharge plasmas

Potential and electron density calculated for freely expanding plasma by an electron beam

International Nuclear Information System (INIS)

Ho, C. Y.; Tsai, Y. H.; Ma, C.; Wen, M. Y.

2011-01-01

This paper investigates the radial distributions of potential and electron density in free expansion plasma induced by an electron beam irradiating on the plate. The region of plasma production is assumed to be cylindrical, and the plasma expansion is assumed to be from a cylindrical source. Therefore, the one-dimensional model in cylindrical coordinates is employed in order to analyze the radial distributions of the potential and electron density. The Runge-Kutta method and the perturbation method are utilized in order to obtain the numerical and approximate solutions, respectively. The results reveal that the decrease in the initial ion energy makes most of the ions gather near the plasma production region and reduces the distribution of the average positive potential, electron, and ion density along the radial direction. The oscillation of steady-state plasma along the radial direction is also presented in this paper. The ions induce a larger amplitude of oscillation along the radial direction than do electrons because the electrons oscillate around slowly moving ions due to a far smaller electron mass than ion mass. The radial distributions of the positive potential and electron density predicted from this study are compared with the available experimental data.

Stability Limits of High-Beta Plasmas in DIII-D

International Nuclear Information System (INIS)

Strait, E.J.

2005-01-01

Stability at high beta is an important requirement for a compact, economically attractive fusion reactor. DIII-D experiments have shown that ideal magnetohydrodynamic (MHD) theory is an accurate predictor of the ultimate stability limits for tokamaks, and the Troyon scaling law has provided a useful approximation of ideal stability limits for discharges with 'conventional' profiles. However, variation of the discharge shape, pressure profile, and current density profile can lead to ideal MHD beta limits that differ significantly from simple Troyon scaling. The need for profiles consistent with steady-state operation places an important additional constraint on plasma stability. Nonideal effects can also be important and must be taken into account. For example, neoclassical tearing modes (NTMs), resulting from plasma resistivity and the nonlinear effects of the bootstrap current, can become unstable at beta values well below the ideal MHD limit. DIII-D experiments are now entering a new era of unprecedented control over plasma stability, including suppression of NTMs by localized current drive at the island location, and direct feedback stabilization of kink modes with a resistive wall. The continuing development of physics understanding and control tools holds the potential for stable, steady-state fusion plasmas at high beta

Cross-field flow and electric potential in a plasma slab

Directory of Open Access Journals (Sweden)

J. De Keyser

2013-08-01

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

Two approaches to the reactor-relevant high-beta plasmas with profile control in the Large Helical Device

International Nuclear Information System (INIS)

Ohdachi, S.; Watanabe, K.Y.; Sakakibara, S.

2008-10-01

From detailed optimization of configuration, volume averaged beta ∼ 5% has been achieved in the Large Helical Device(LHD). While the heating efficiency was the main point to be optimized in this approach, to form a more peaked pressure profile is another promising approach towards the high beta regime. A higher electron density profile with a steeper pressure gradient has been formed by pellet injection. From the MHD stability analysis, this peaked pressure profile is stable against the ideal MHD modes. By both approaches, the central plasma β 0 reaches about 10%. (author)

A study of the transient plasma potential in a pulsed bi-polar dc magnetron discharge

International Nuclear Information System (INIS)

Bradley, J W; Karkari, S K; Vetushka, A

2004-01-01

The temporal evolution of the plasma potential, V p , in a pulsed dc magnetron plasma has been determined using the emissive probe technique. The discharge was operated in the 'asymmetric bi-polar' mode, in which the discharge voltage changes polarity during part of the pulse cycle. The probe measurements, with a time-resolution of 20 ns or better, were made along a line above the racetrack, normal to the plane of the cathode target, for a fixed frequency (100 kHz), duty cycle (50%), argon pressure (0.74 Pa) and discharge power (583 W). At all the measured positions, V p was found to respond to the large and rapid changes in the cathode voltage, V d , during the different phases of the pulse cycle, with V p always more positive than V d . At a typical substrate position (>80 mm from the target), V p remains a few volts above the most positive surface in the discharge at all times. In the 'on' phase of the pulse, the measurements show a significant axial electric field is generated in the plasma, with the plasma potential dropping by a total of about 30 V over a distance of 70 mm, from the bulk plasma to a position close to the beginning of the cathode fall. This is consistent with measurements made in the dc magnetron. During the stable 'reverse' phase of the discharge, for distances greater than 18 mm from the target, the axial electric field is found to collapse, with V p elevated uniformly to about 3 V above V d . Between the target and this field-free region an ion sheath forms, and the current flowing to the target is still an ion current in this 'reverse' period. During the initial 200 ns of the voltage 'overshoot' phase (between 'on' and 'reverse' phases), V d reached a potential of +290 V; however, close to the target, V p was found to attain a much higher value, namely +378 V. Along the line of measurement, the axial electric field reverses in direction in this phase, and an electron current of up to 9 A flows to the target. The spatial and temporal

Kinetic theory of neutrals in a bounded plasma slab with inhomogeneous temperature and density profile

International Nuclear Information System (INIS)

Tendler, M.B.; Agren, O.

1982-01-01

The transport of neutral hydrogen atoms in a hydrogen plasma slab is considered. The influence of the inhomogeneous ion temperature profile on the neutral density and distribution is discussed as well as the influence of the neutral edge energy, charge exchange, and ionization rates. The analytical solutions for the neutral density and distribution function are obtained and compared with the numerical results. The effects due to the inhomogeneous temperature profile are discussed. The recommen-dations from the viewpoint of the effects mentioned previously for the purposes of the cold-gas mantle system have been given

Investigation of plasma potential and pulsed discharge characteristics in enhanced glow discharge plasma immersion ion implantation and deposition

International Nuclear Information System (INIS)

Li Liuhe; Lu Qiuyuan; Fu, Ricky K.Y.; Chu, Paul K.

2009-01-01

Enhanced glow discharge plasma immersion ion implantation and deposition (EGD-PII and D) does not require external plasma sources. In this technique, the plasma is produced by self-glow discharge when a high negative voltage is applied to the sample. The small-area, pointed-shape hollow anode and large area tabular cathode form an electron-focused electric field. Using a special electric field design, the electrons from either the plasma or target (secondary electrons) are focused to a special hollow anode. As a result of the special electron-focusing field, the self-glow discharge process can be enhanced to achieve effective ion implantation into the substrate. In this work, the plasma potential distribution is investigated in details and the possible pulse discharge mechanism is discussed. The unique characteristics of the pulsed plasma and plasma extinction are studied.

Relativistic self-focusing of ultra-high intensity X-ray laser beams in warm quantum plasma with upward density profile

International Nuclear Information System (INIS)

Habibi, M.; Ghamari, F.

2014-01-01

The results of a numerical study of high-intensity X-ray laser beam interaction with warm quantum plasma (WQP) are presented. By means of an upward ramp density profile combined with quantum factors specially the Fermi velocity, we have demonstrated significant relativistic self-focusing (RSF) of a Gaussian electromagnetic beam in the WQP where the Fermi temperature term in the dielectric function is important. For this purpose, we have considered the quantum hydrodynamics model that modifies refractive index of inhomogeneous WQPs with the inclusion of quantum correction through the quantum statistical and diffraction effects in the relativistic regime. Also, to better illustration of the physical difference between warm and cold quantum plasmas and their effect on the RSF, we have derived the envelope equation governing the spot size of X-ray laser beam in Q-plasmas. In addition to the upward ramp density profile, we have found that the quantum effects would be caused much higher oscillation and better focusing of X-ray laser beam in the WQP compared to that of cold quantum case. Our computational results reveal the importance of the use of electrons density profile and Fermi speed in enhancing self-focusing of laser beam

Presheath profiles in simulated tokamak edge plasmas

International Nuclear Information System (INIS)

LaBombard, B.; Conn, R.W.; Hirooka, Y.; Lehmer, R.; Leung, W.K.; Nygren, R.E.; Ra, Y.; Tynan, G.

1988-04-01

The PISCES plasma surface interaction facility at UCLA generates plasmas with characteristics similar to those found in the edge plasmas of tokamaks. Steady state magnetized plasmas produced by this device are used to study plasma-wall interaction phenomena which are relevant to tokamak devices. We report here progress on some detailed investigations of the presheath region that extends from a wall surface into these /open quotes/simulated tokamak/close quotes/ edge plasma discharges along magnetic field lines

Estimate of electrical potential difference between plasmas with different degrees of ionization

Energy Technology Data Exchange (ETDEWEB)

Chang, Chong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-01-12

The electrical potential difference has been estimated across the mixing region of two plasmas with different degrees of ionization. The estimation has been carried out in two different contexts of a charge neutral mixing region and a charge non-neutral sheath. Ion energy gained due to the potential difference has also been estimated. In both analyses, ion energy gain is proportional to the degree of ionization, and a fairly large ionization appears to be needed for overcoming the potential energy barrier of strongly coupled plasmas.

Plasma-potential diagnostic (PPD) hardware used on the Tandem Mirror Experiment-Upgrade (TMX-U)

International Nuclear Information System (INIS)

Steele, D.L.; Hornady, R.S.; Stever, R.D.; Coutts, G.W.; Nelson, D.H.

1985-01-01

The PPD is an instrument used to indirectly measure the potential of the center-cell plasma of TMX-U. Thallium ions are injected at energies of about 60 keV from an ion gun capable of 80 kV operation. The singly charged ions collide with plasma electrons and generate double-charged ions. Ions in the higher charge state exit the plasma and are detected in an electrostatic energy analyzer. From measurements of the injected ion energy and the output ion energy one can determine the plasma potential in the ionization region. The absolute potential measurements required careful calibrations of the energy analyzer. Hardware and techniques for calibration of the energy analyzer are discussed. 2 refs., 4 figs

How is plasma profile determined?

International Nuclear Information System (INIS)

Itoh, Kimitaka; Itoh, Sanae

1991-01-01

The plasma of toroidal system magnetic field confinement which is represented by tokamak is realized as dissipating structure which is maintained by the supply of energy and particles. Besides the spatial distributions of heat, particles and momentum inside plasma take various forms, there are the transition phenomena among the distributions with different forms, intermittent energy loss, the exchange of spatial positions among ions and so on, accordingly confined plasma is the treasure house of the transport phenomena accompanied by various temporal and spatial scales. Now might be the time that the unknown physics being concealed with veil becomes clear. In this report, by taking tokamaks as the example, concerning the transport phenomena in plasma, the recent development on the physical phenomena and the comparison of the theoretical model with the experiment is explained. The formulation of transport phenomena, the elementary process of transport by flickering, transport matrix, waves in drift frequency band, boundary condition, the comparison of transport in steady state, the research on the time change of distribution, and the correlation of flickering and transport are described. (K.I.)

Changes in the Plasma Sex Hormone Profile in Males with Severe Concomitant Injury

Directory of Open Access Journals (Sweden)

K. N Yezhova

2009-01-01

Full Text Available Objective: to perform a complex study of typical plasma sex hormone changes and their functional significance in males with severe concomitant injury (SCI. Subjects and methods. Fifty-nine males aged 18—49 years who had SCI were enrolled in the study. The admission severity was an APACHE II score of 18.6±2.4. According to the outcome of the disease, all the patients were divided into 2 groups: A survivors; B deceased persons. A control comprised 12 healthy male donors aged 19-36 years, in whom the levels of 8 sex steroids were measured. The standard procedures were used to comparatively analyze the concentrations of pituitary reproductive hormones and aldosterone. Hormonal concentrations were studied over time on posttraumatic days 1, 3, 5, 7, 10, and 15. The plasma hormone profile was examined by test kits (BSL, USA on a Stat Fax 2100 device (Awareness Technology Inc., USA for enzyme immunoassay. Prolactin, luteinizing hormone (LH, follicle-stimulating hormone (FSH, progesterone (P, 17-hydroxyprogesterone (17-OH-P, dehydroepiandrosterone sulfate (DHEA-S, androstendione (A, testosterone (T, dihydrotestosterone (DHT, estrone (E1, estradiol (E2, and aldosterone were determined. Results. The complex study of phasic changes in the profile of 11 plasma sex hormones was first conducted in males in the posttraumatic period. Moreover, the typical plasma hormonal changes were elevated prolactin levels and their phasic variations, normal LH and FSH levels with a tendency for further phasic LH changes and FSH reduction. After the injury, the plasma concentration of P was increased and that of 17-OH-P was decreased. The levels of A and DHEA-S varied in the normal range with a tendency for DHEA-S to be lower during the process. In the posttraumatic period, the plasma content of T and DHT was substantially reduced and that of E1 and E2 was increased. The deceased patients generally showed higher levels of A, DHEA-S, and estrogens as a reflection of

Diagnosis of adenylosuccinate lyase deficiency by metabolomic profiling in plasma reveals a phenotypic spectrum

Directory of Open Access Journals (Sweden)

Taraka R. Donti

2016-09-01

Full Text Available Adenylosuccinate lyase (ADSL deficiency is a rare autosomal recessive neurometabolic disorder that presents with a broad-spectrum of neurological and physiological symptoms. The ADSL gene produces an enzyme with binary molecular roles in de novo purine synthesis and purine nucleotide recycling. The biochemical phenotype of ADSL deficiency, accumulation of SAICAr and succinyladenosine (S-Ado in biofluids of affected individuals, serves as the traditional target for diagnosis with targeted quantitative urine purine analysis employed as the predominate method of detection. In this study, we report the diagnosis of ADSL deficiency using an alternative method, untargeted metabolomic profiling, an analytical scheme capable of generating semi-quantitative z-score values for over 1000 unique compounds in a single analysis of a specimen. Using this method to analyze plasma, we diagnosed ADSL deficiency in four patients and confirmed these findings with targeted quantitative biochemical analysis and molecular genetic testing. ADSL deficiency is part of a large a group of neurometabolic disorders, with a wide range of severity and sharing a broad differential diagnosis. This phenotypic similarity among these many inborn errors of metabolism (IEMs has classically stood as a hurdle in their initial diagnosis and subsequent treatment. The findings presented here demonstrate the clinical utility of metabolomic profiling in the diagnosis of ADSL deficiency and highlights the potential of this technology in the diagnostic evaluation of individuals with neurologic phenotypes.

Establishing a milkborne disease outbreak profile: potential food defense implications.

Science.gov (United States)

Newkirk, Ryan; Hedberg, Craig; Bender, Jeff

2011-03-01

The main objectives of this study were to establish baseline characteristics for milkborne outbreaks, establish an expected milkborne outbreak profile, and identify potential indicators of food terrorism. This study used 1990-2006 data from the Centers for Disease Control and Prevention Annual Listings of Disease Outbreaks and the Foodborne Outbreak Database (FOOD) to establish epidemiologic baseline characteristics for disease outbreaks associated with fluid milk. FOOD data from 2007 were used to qualitatively validate the potential of the baseline characteristics and the expected outbreak profile. Eighty-three fluid milkborne outbreaks were reported between 1990 and 2006, resulting in 3621 illnesses. The mean number of illnesses per outbreak was 43.6 (illness range: 2-1644). Consumption of unpasteurized milk was associated with 55.4% of reported outbreaks. Campylobacter spp., Escherichia coli, and Salmonella spp. caused 51.2%, 10.8%, and 9.6% of reported outbreaks, respectively. Private homes accounted for 41.0% of outbreak locations. Number ill, outbreak location, and etiology were the primary characteristics which could signal a potential intentional contamination event. In 2007, one pasteurized milk outbreak caused by Listeria was flagged as aberrative compared with the expected outbreak profile. The creation and dissemination of expected outbreak profiles and epidemiologic baseline characteristics allow public health and Homeland Security officials to quickly assess the potential of intentional food contamination. A faster public health and medical system response can result in decreased morbidity and mortality.

Applications of nutrient profiling: potential role in diet-related chronic disease prevention and the feasibility of a core nutrient-profiling system.

Science.gov (United States)

Sacks, G; Rayner, M; Stockley, L; Scarborough, P; Snowdon, W; Swinburn, B

2011-03-01

A number of different nutrient-profiling models have been proposed and several applications of nutrient profiling have been identified. This paper outlines the potential role of nutrient-profiling applications in the prevention of diet-related chronic disease (DRCD), and considers the feasibility of a core nutrient-profiling system, which could be modified for purpose, to underpin the multiple potential applications in a particular country. The 'Four 'P's of Marketing' (Product, Promotion, Place and Price) are used as a framework for identifying and for classifying potential applications of nutrient profiling. A logic pathway is then presented that can be used to gauge the potential impact of nutrient-profiling interventions on changes in behaviour, changes in diet and, ultimately, changes in DRCD outcomes. The feasibility of a core nutrient-profiling system is assessed by examining the implications of different model design decisions and their suitability to different purposes. There is substantial scope to use nutrient profiling as part of the policies for the prevention of DRCD. A core nutrient-profiling system underpinning the various applications is likely to reduce discrepancies and minimise the confusion for regulators, manufacturers and consumers. It seems feasible that common elements, such as a standard scoring method, a core set of nutrients and food components, and defined food categories, could be incorporated as part of a core system, with additional application-specific criteria applying. However, in developing and in implementing such a system, several country-specific contextual and technical factors would need to be balanced.

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.

A contoured gap coaxial plasma gun with injected plasma armature

International Nuclear Information System (INIS)

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

2009-01-01

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

Measurements of radial profiles of ion cyclotron resonance heating on the tandem mirror experiment

International Nuclear Information System (INIS)

Falabella, S.

1988-01-01

A small Radial Energy Analyzer (REA) was used on the Tandem Mirror Experiment-Upgrade (TMX-U), at Lawrence Livermore National Laboratory, to investigate the radial profiles of ion temperature, density, and plasma potential during Ion Cyclotron Resonance Heating (ICRH). This analyzer indicates an increase in ion temperature from ∼20 eV before ICRH to ∼150 eV during ICRH, with ∼60 kW of broadcast power. The REA measurements were cross-checked against other diagnostics on TMX-U and found to be consistent. The ion density measurement was compared to the line-density measured by microwave interferometry and found to agree within 10 to 20%. A radial integral of n i T i as measured by the REA shows good agreement with the diamagnetic loop measurement of plasma energy. The radial density profile is observed to broaden during the RF heating pulses, without inducing additional radial losses in the core plasma. The radial profile of plasma potential is seen to vary from axially peaked, to nearly flat, as the plasma conditions varied over the series of experiments. To relate the increase in ion temperature to power absorbed by the plasma, a power balance as a function of radius was performed. The RF power absorbed is set equal to the sum of the losses during ICRH, minus those without ICRH. This method accounts for more than 70% of the broadcast power using a simple power balance model. The measured radial profile of the RF heating was compared to the calculations of two codes, ANTENA and GARFIELD, to test their effectiveness as predictors of power absorption profiles for TMX-U

Measurements of plasma profiles using a fast swept Langmuir probe in the VINETA-II magnetic reconnection experiment

Science.gov (United States)

Shesterikov, I.; Von Stechow, A.; Grulke, O.; Stenzel, R.; Klinger, T.

2017-07-01

A fast-swept Langmuir probe capable to be biased at a high voltages has been constructed and successfully operated at the VINETA-II magnetic reconnection experiment. The presented circuit has two main features beneficial for fast transient parameter changes in laboratory experiments as, e.g., plasma guns or magnetic reconnection: the implementation simplicity and the high voltage sweep range. This work presents its design and performance for time-dependent measurements of VINETA-II plasmas. The probe is biased with a sinusoidal voltage at a fixed frequency. Current - voltage characteristics are measured along the falling and rising slopes of the probe bias. The sweep frequency is fsweep= 150 kHz. The spatiotemporal evolution of radial plasma profiles is obtained by evaluation of the probe characteristics. The plasma density measurements agree with those derived from a microwave interferometer, demonstrating the reliability of the measurements. As a model plasma system, a plasma gun discharge with typical pulse times of 60 μ s is chosen.

Electric potential differences across auroral generator interfaces

Directory of Open Access Journals (Sweden)

J. De Keyser

2013-02-01

Full Text Available Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. The present paper explores the role of this cross-field electric potential difference in the situation where the interface is a tangential discontinuity. A self-consistent Vlasov description is used to determine the equilibrium configuration for different values of the transverse potential difference. A major observation is that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing primarily when the temperature contrast is large. These findings strongly support the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.

Experimental studies of collisional plasma shocks and plasma interpenetration via merging supersonic plasma jets

Science.gov (United States)

Hsu, S. C.; Moser, A. L.; Merritt, E. C.; Adams, C. S.

2015-11-01

Over the past 4 years on the Plasma Liner Experiment (PLX) at LANL, we have studied obliquely and head-on-merging supersonic plasma jets of an argon/impurity or hydrogen/impurity mixture. The jets are formed/launched by pulsed-power-driven railguns. In successive experimental campaigns, we characterized the (a) evolution of plasma parameters of a single plasma jet as it propagated up to ~ 1 m away from the railgun nozzle, (b) density profiles and 2D morphology of the stagnation layer and oblique shocks that formed between obliquely merging jets, and (c) collisionless interpenetration transitioning to collisional stagnation between head-on-merging jets. Key plasma diagnostics included a fast-framing CCD camera, an 8-chord visible interferometer, a survey spectrometer, and a photodiode array. This talk summarizes the primary results mentioned above, and highlights analyses of inferred post-shock temperatures based on observations of density gradients that we attribute to shock-layer thickness. We also briefly describe more recent PLX experiments on Rayleigh-Taylor-instability evolution with magnetic and viscous effects, and potential future collisionless shock experiments enabled by low-impurity, higher-velocity plasma jets formed by contoured-gap coaxial guns. Supported by DOE Fusion Energy Sciences and LANL LDRD.

The potential around a test charge in magnetized dusty plasmas

International Nuclear Information System (INIS)

Shukla, P.K.; Salimullah, M.

1996-01-01

The potential of a test dust particle in a magnetized dusty plasma is calculated, taking into account the dielectric constant associated with electrostatic ion-cyclotron waves. Besides the well-known Debye-Hueckel screening potential, an oscillatory potential distribution around a test dust particle is found, which strongly depends on the strength of the external magnetic field. copyright 1996 American Institute of Physics

Plane and hemispherical potential structures in magnetically expanding plasmas

International Nuclear Information System (INIS)

Takahashi, Kazunori; Igarashi, Yuichi; Fujiwara, Tamiya

2010-01-01

Two-dimensional potential structures are measured for different gas pressure in expanding argon plasma using permanent magnets, where the magnetic field is about 100 G in the source and several gauss in the diffusion chamber. The plane potential drop is observed near the source exit for 0.35 mTorr, while the potential structure becomes hemispherical when increasing up to 1 mTorr; the hemispherical structure results in the radial divergence of the ion beam. It is found that the trajectories of the accelerated ions and the electrons overcoming the potential drop are dominated by the potential structure and magnetic-field lines, respectively.

Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography–mass spectrometry

NARCIS (Netherlands)

Akoto, L.; Vreuls, R.J.J.; Irth, H.; Pel, R.; Stellaard, F.

2008-01-01

Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal

Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry.

NARCIS (Netherlands)

Akoto, L.; Vreuls, J.J.; Irth, H.; Pel, R.; Stellaard, F.

2008-01-01

Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal

Fatty acid profiling of raw human plasma and whole blood using direct thermal desorption combined with gas chromatography-mass spectrometry

NARCIS (Netherlands)

Akoto, Lawrence; Vreuls, Rene J. J.; Irth, Hubertus; Pel, Roel; Stellaard, Frans

2008-01-01

Gas chromatography (GC) has in recent times become an important tool for the fatty acid profiling of human blood and plasma. An at-line procedure used in the fatty acid profiling of whole/intact aquatic micro-organisms without any sample preparation was adapted for this work. A direct thermal

A direct indication of plasma potential diagnostic with fast time response and high accuracy based on a differential emissive probe

International Nuclear Information System (INIS)

Yao, W.E.; Hershkowitz; Intrator, T.

1985-01-01

The floating potential of the emissive probe has been used to directly measure the plasma potential. The authors have recently presented another method for directly indicating the plasma potential with a differential emissive probe. In this paper they describe the effects of probe size, plasma density and plasma potential fluctuation on plasma potential measurements and give methods for reducing errors. A control system with fast time response (α 20 μs) and high accuracy (the order of the probe temperature T/sub w//e) for maintaining a differential emissive probe at plasma potential has been developed. It can be operated in pulsed discharge plasma to measure plasma potential dynamic characteristics. A solid state optical coupler is employed to improve circuit performance. This system was tested experimentally by measuring the plasma potential in an argon plasma device an on the Phaedrus tandem mirror

A direct indication of plasma potential diagnostic with fast time response and high accuracy based on a differential emissive probe

International Nuclear Information System (INIS)

Yao, W.E.; Hershkowitz, N.; Intrator, T.

1985-01-01

The floating potential of the emissive probe has been used to directly measure the plasma potential. The authors have recently presented another method for directly indicating the plasma potential with a differential emissive probe. In this paper they describe the effects of probe size, plasma density and plasma potential fluctuation on plasma potential measurements and give methods for reducing errors. A control system with fast time response (≅ 20 μs) and high accuracy (the order of the probe temperature T/sub w//e) for maintaining a differential emissive probe at plasma potential has been developed. It can be operated in pulsed discharge plasma to measure plasma potential dynamic characteristics. A solid state optical coupler is employed to improve circuit performance. This system was tested experimentally by measuring the plasma potential in an argon plasma device and on the Phaedrus tandem mirror

Metabolic profiling of human lung cancer blood plasma using 1H NMR spectroscopy

Science.gov (United States)

Kokova, Daria; Dementeva, Natalia; Kotelnikov, Oleg; Ponomaryova, Anastasia; Cherdyntseva, Nadezhda; Kzhyshkowska, Juliya

2017-11-01

Lung cancer (both small cell and non-small cell) is the second most common cancer in both men and women. The article represents results of evaluating of the plasma metabolic profiles of 100 lung cancer patients and 100 controls to investigate significant metabolites using 400 MHz 1H NMR spectrometer. The results of multivariate statistical analysis show that a medium-field NMR spectrometer can obtain the data which are already sufficient for clinical metabolomics.

Heating and active control of profiles and transport by IBW in the HT-7 tokamak

International Nuclear Information System (INIS)

Zhao Yanping; Wan Baonian; Li Jiangang

2003-01-01

Significant progress on Ion Bernstein Wave (IBW) heating and control of profiles has been obtained in HT-7. Both on-axis and off-axis electron heating with global peaked and local steep electron pressure profiles were realized if the position of the resonant layer was selected to be plasma far from the plasma edge region. Reduction of electron heat transport has been observed from sawtooth heat pulse propagation. Improvement of both particle and energy confinement was slight in the on-axis and considerable in the off-axis heating cases. The improved confinement in off-axis heating mode may be due to the extension of the high performance plasma volume caused by IBW. These studies demonstrate that IBWs are potentially a tool for active control of plasma profiles and transport. (author)

A study of the potential of plasma processing in the chemical industry

International Nuclear Information System (INIS)

Estey, P.N.; Connolly, T.J.

1984-01-01

This work describes a systematic approach to determine the potential for plasma processing in the United States chemical industry. A model was developed that describes the physical inputs and outputs from a plasma based processing system. Based on these mass flows and the energy flows to the processor an economic assessment of the plasma processing system is made. This economic assessment which also includes the capital costs of the processor, can be used to determine if the plasma system is competitive with the conventional system

Evolution of the radial electric field in a JET H-mode plasma

International Nuclear Information System (INIS)

Andrew, Y.; Hawkes, N.C.; Biewer, T.; Crombe, K.; Keeling, D.; De la Luna, E.; Giroud, C.; Korotkov, A.; Meigs, A.; Murari, A.; Nunes, I.; Sartori, R.; Tala, T.; Andrew, Y.; Hawkes, N.C.; Keeling, D.; Giroud, C.; Korotkov, A.; Meigs, A.; Biewer, T.; Crombe, K.; De la Luna, E.; Murari, A.; Nunes, I.; Sartori, R.; Tala, T.

2008-01-01

Results from recent measurements of carbon impurity ion toroidal and poloidal rotation velocities, ion temperature, ion density and the resulting radial electric field (E r ) profiles are presented from an evolving Joint European Torus (JET) tokamak plasma over a range of energy and particle confinement regimes. Significant levels of edge plasma poloidal rotation velocity have been measured for the first time on JET, with maximum values of ±9 km/s. Such values of poloidal rotation provide an important contribution to the total edge plasma E r profiles. Large values of shear in the measured E r profiles are observed to arise as a consequence of the presence of the edge transport barrier (ETB) and do not appear to be necessary for their formation or destruction. These results have an important impact on potential mechanisms for transport barrier triggering and sustainment in present-day and future high-performance fusion plasmas. (authors)

Effect of confining wall potential on charged collimated dust beam in low-pressure plasma

International Nuclear Information System (INIS)

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

2013-01-01

The effect of confining wall potential on charged collimated dust beam in low-pressure plasma has been studied in a dusty plasma experimental setup by applying electrostatic field to each channel of a multicusp magnetic cage. Argon plasma is produced by hot cathode discharge method at a pressure of 5×10 −4 millibars and is confined by a full line cusped magnetic field confinement system. Silver dust grains are produced by gas-evaporation technique and move upward in the form of a collimated dust beam due to differential pressure maintained between the dust and plasma chambers. The charged grains in the beam after coming out from the plasma column enter into the diagnostic chamber and are deflected by a dc field applied across a pair of deflector plates at different confining potentials. Both from the amount of deflection and the floating potential, the number of charges collected by the dust grains is calculated. Furthermore, the collimated dust beam strikes the Faraday cup, which is placed above the deflector plates, and the current (∼pA) so produced is measured by an electrometer at different confining potentials. The experimental results demonstrate the significant effect of confining wall potential on charging of dust grains

Effect of confining wall potential on charged collimated dust beam in low-pressure plasma

Energy Technology Data Exchange (ETDEWEB)

Kausik, S. S.; Kakati, B.; Saikia, B. K. [Centre of Plasma Physics, Institute for Plasma Research, Sonapur 782 402 (India)

2013-05-15

The effect of confining wall potential on charged collimated dust beam in low-pressure plasma has been studied in a dusty plasma experimental setup by applying electrostatic field to each channel of a multicusp magnetic cage. Argon plasma is produced by hot cathode discharge method at a pressure of 5×10{sup −4} millibars and is confined by a full line cusped magnetic field confinement system. Silver dust grains are produced by gas-evaporation technique and move upward in the form of a collimated dust beam due to differential pressure maintained between the dust and plasma chambers. The charged grains in the beam after coming out from the plasma column enter into the diagnostic chamber and are deflected by a dc field applied across a pair of deflector plates at different confining potentials. Both from the amount of deflection and the floating potential, the number of charges collected by the dust grains is calculated. Furthermore, the collimated dust beam strikes the Faraday cup, which is placed above the deflector plates, and the current (∼pA) so produced is measured by an electrometer at different confining potentials. The experimental results demonstrate the significant effect of confining wall potential on charging of dust grains.

Effect of confining wall potential on charged collimated dust beam in low-pressure plasma

Science.gov (United States)

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

2013-05-01

The effect of confining wall potential on charged collimated dust beam in low-pressure plasma has been studied in a dusty plasma experimental setup by applying electrostatic field to each channel of a multicusp magnetic cage. Argon plasma is produced by hot cathode discharge method at a pressure of 5×10-4 millibars and is confined by a full line cusped magnetic field confinement system. Silver dust grains are produced by gas-evaporation technique and move upward in the form of a collimated dust beam due to differential pressure maintained between the dust and plasma chambers. The charged grains in the beam after coming out from the plasma column enter into the diagnostic chamber and are deflected by a dc field applied across a pair of deflector plates at different confining potentials. Both from the amount of deflection and the floating potential, the number of charges collected by the dust grains is calculated. Furthermore, the collimated dust beam strikes the Faraday cup, which is placed above the deflector plates, and the current (˜pA) so produced is measured by an electrometer at different confining potentials. The experimental results demonstrate the significant effect of confining wall potential on charging of dust grains.

Plasma-potentiated small molecules—possible alternative to antibiotics?

Science.gov (United States)

Bazaka, Kateryna; Bazaka, Olha; Levchenko, Igor; Xu, Shuyan; Ivanova, Elena P.; Keidar, Michael; (Ken Ostrikov, Kostya

2017-09-01

The efficacy of the existing arsenal of antibiotics is continuously compromised by their indiscriminative and often excessive use. The antibiotic arsenal can be expanded with agents that have different mechanisms of activity to conventional drugs, such as plant-derived natural antimicrobial small molecules, yet these often lack sufficient activity and selectivity to fulfill the antibiotics requirements and conventional thermochemical methods of their transient activation may not be compatible with biomedical applications. Here, non-equilibrium conditions of atmospheric-pressure plasma are used for rapid, single-step potentiation of activity of select terpenes without the use of chemicals or heating. Substantial potentiation of activity against Staphylococcus aureus cells in planktonic and biofilm states is observed in both inherently antibacterial terpenes, e.g. terpinen-4-ol, and compounds generally considered to have limited effect against S. aureus, e.g. γ-terpinene. The improved biological activity may arise, at least in part, from the changes in the physico-chemical properties of the terpenes induced by plasma-generated chemical species and physical effects, such as electric fields and UV irradiation. This activation approach is generic, and thus can potentially be applied to other molecules and their mixtures in an effort to expand the range of effective antimicrobial agents for deactivation of pathogenic organisms in hygiene, medical and food applications.

Potential measurements in tandem mirrors

International Nuclear Information System (INIS)

Glowienka, J.C.

1985-11-01

The US mirror program has begun conducting experiments with a thermal barrier tandem mirror configuration. This configuration requires a specific axial potential profile and implies measurements of potential for documentation and optimization of the configuration. This report briefly outlines the motivation for the thermal barrier tandem mirror and then outlines the techniques used to document the potential profile in conventional and thermal barrier tandem mirrors. Examples of typical data sets from the world's major tandem mirror experiments, TMX and TMX-U at Lawrence Livermore National Laboratory (LLNL) and Gamma 10 at Tsukuba University in Japan, and the current interpretation of the data are discussed together with plans for the future improvement of measurements of plasma potential

High Fat Diet Exposure during Fetal Life Enhances Plasma and Hepatic Omega-6 Fatty Acid Profiles in Fetal Wistar Rats

Directory of Open Access Journals (Sweden)

Marlon E. Cerf

2015-08-01

Full Text Available Pregnant rats were fed a high fat diet (HFD for the first (HF1, second (HF2, third (HF3 or all three weeks (HFG of gestation. Maintenance on a HFD during specific periods of gestation was hypothesized to alter fetal glycemia, insulinemia, induce insulin resistance; and alter fetal plasma and hepatic fatty acid (FA profiles. At day 20 of gestation, fetal plasma and hepatic FA profiles were determined by gas chromatography; body weight, fasting glycemia, insulinemia and the Homeostasis Model Assessment (HOMA-insulin resistance were also determined. HF3 fetuses were heaviest concomitant with elevated glycemia and insulin resistance (p < 0.05. HFG fetuses had elevated plasma linoleic (18:2 n-6 and arachidonic (20:4 n-6 acid proportions (p < 0.05. In the liver, HF3 fetuses displayed elevated linoleic, eicosatrienoic (20:3 n-6 and arachidonic acid proportions (p < 0.05. HFG fetuses had reduced hepatic docosatrienoic acid (22:5 n-3 proportions (p < 0.05. High fat maintenance during the final week of fetal life enhances hepatic omega-6 FA profiles in fetuses concomitant with hyperglycemia and insulin resistance thereby presenting a metabolically compromised phenotype.

Plasma heating

International Nuclear Information System (INIS)

Wilhelm, R.

1989-01-01

Successful plasma heating is essential in present fusion experiments, for the demonstration of DpT burn in future devices and finally for the fusion reactor itself. This paper discusses the common heating systems with respect to their present performance and their applicability to future fusion devices. The comparative discussion is oriented to the various function of heating, which are: - plasma heating to fusion-relevant parameters and to ignition in future machines, -non-inductive, steady-pstate current drive, - plasma profile control, -neutral gas breakdown and plasma build-up. In view of these different functions, the potential of neutral beam injection (NBI) and the various schemes of wave heating (ECRH, LH, ICRH and Alven wave heating) is analyzed in more detail. The analysis includes assessments of the present physical and technical state of these heating methods, and makes suggestions for future developments and about outstanding problems. Specific attention is given to the still critical problem of efficient current drive, especially with respect to further extrapolation towards an economically operating tokamak reactor. Remarks on issues such as reliability, maintenance and economy conclude this comparative overview on plasma heating systems. (author). 43 refs.; 13 figs.; 3 tabs

Fish oil affects blood pressure and the plasma lipid profile in healthy Danish infants

DEFF Research Database (Denmark)

Damsgaard, C.T.; Schack-Nielsen, L.; Michaelsen, K.F.

2006-01-01

with an oscillometric device, and blood was sampled for analysis of erythrocyte fatty acid composition and the plasma lipid profile. This paper examines the effects of the fish oil supplement, with adjustment for the effects of the milk intervention when relevant. The fish oil intervention increased erythrocyte (n-3......Animal and epidemiologic studies indicate that early nutrition has lasting effects on metabolism and cardiovascular disease risk. In adults, (n-3) long-chain PUFA (LCPUFA) from fish oils improve blood pressure, the lipid profile, and possibly cardiovascular disease mortality. This randomized trial...... is the first to investigate the effects of fish oil on blood pressure and the lipid profile in infancy. Healthy term 9-mo old infants In 83) were randomly assigned to 5 mL fish oil daily or no fish oil for 3 mo and to 2 different milk types. Before and after the intervention, blood pressure was measured...

Fish oil decreases C-reactive protein/albumin ratio improving nutritional prognosis and plasma fatty acid profile in colorectal cancer patients.

Science.gov (United States)

Mocellin, Michel Carlos; Pastore e Silva, Juliana de Aguiar; Camargo, Carolina de Quadros; Fabre, Maria Emília de Souza; Gevaerd, Scheila; Naliwaiko, Katya; Moreno, Yara Maria Franco; Nunes, Everson Araújo; Trindade, Erasmo Benicio Santos de Moraes

2013-09-01

Previous studies have shown that n-3 polyunsaturated fatty acids n-3 (n-3 PUFA) have several anticancer effects, especially attributed to their ability to modulate a variety of genomic and immune responses. In this context, this randomized, prospective, controlled clinical trial was conducted in order to check whether supplementation of 2 g/day of fish oil for 9 weeks alters the production of inflammatory markers, the plasma fatty acid profile and the nutritional status in patients with colorectal cancer (CRC). Eleven adults with CRC in chemotherapy were randomized into two groups: (a) supplemented (SG) daily with 2 g/day of encapsulated fish oil [providing 600 mg/day of eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA)] for 9 weeks (n = 6), and (b) control (CG) (n = 5). All outcomes were evaluated on the day before the first chemotherapy session and 9 weeks later. Plasma TNF-α, IL-1β, IL-10 and IL-17A, the pro/anti-inflammatory balance (ratio TNF-α/IL-10 and IL-1β/IL10) and serum albumin, showed no significant changes between times and study groups (p > 0.05). C-reactive protein (CRP) and the CRP/albumin ratio showed opposite behavior in groups, significantly reducing their values in SG (p < 0.05). Plasma proportions of EPA and DHA increased 1.8 and 1.4 times, respectively, while the ARA reduced approximately 0.6 times with the supplementation (9 weeks vs baseline, p < 0.05). Patients from SG gained 1.2 kg (median) while the CG lost -0.5 kg (median) during the 9 weeks of chemotherapy (p = 0.72). These results demonstrate that 2 g/day of fish oil for 9 weeks of chemotherapy improves CRP values, CRP/albumin status, plasma fatty acid profile and potentially prevents weight loss during treatment.

Onsager relaxation of toroidal plasmas

International Nuclear Information System (INIS)

Samain, A.; Nguyen, F.

1997-01-01

The slow relaxation of isolated toroidal plasmas towards their thermodynamical equilibrium is studied in an Onsager framework based on the entropy metric. The basic tool is a variational principle, equivalent to the kinetic equation, involving the profiles of density, temperature, electric potential, electric current. New minimization procedures are proposed to obtain entropy and entropy production rate functionals. (author)

Analysis of protein profiles in diabetic rat blood plasma that induced by alloxan

Science.gov (United States)

Hidayati, Dewi; Abdulgani, Nurlita; Setiyawan, Hengki; Trisnawati, Indah; Ashuri, Nova Maulidina; Sa'adah, Noor Nailis

2017-06-01

Proteomics is the study to identify the proteins involved in physiological metabolic pathway. The protein profiles of blood plasma from alloxan-induced diabetic rats has investigated using Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). Data were analyzed descriptively based on variations of the type and intensity of the protein. There were identified the similarity of protein variant between diabetic and control rats included ankyrin (200kDa), IgG (150kDa), nephrin (136 kDa), IDE (112 kDA), albumin (66 kDa), prealbumin (55 kDA), CICP (43 kDa), ApoA-V (39 kDa), GAPDH (35 kDa), C-RP (27,1 kDa), leptin (16 kDa) and apelin (13 kDa). However, the apelin profile at diabetic rats shows the higher intensity than control.

Transport analysis of oscillatory state for plasma dynamics in helical plasmas

International Nuclear Information System (INIS)

Toda, S.; Itoh, K.

2012-11-01

In helical plasmas, two kinds of the oscillation for the plasma quantities are experimentally observed. Firstly, the limit cycle phenomena in the temporal evolution of the electrostatic potential, namely the electric pulsation, have been observed in the core region. The temporally self-generated oscillation of the radial electric field is shown as a simulation result in the core region. The dependence of the transition point for the radial electric field on the source is examined. Secondly, the density limit oscillation in the helical device was reported. To realize the oscillation phenomena at the density limit, the temporal evolution of the density profile is newly included in a simulation when the radiative loss is calculated in the edge region. Two stationary plasma states, where the transport loss or radiative loss is dominant in the edge region, are obtained. The dynamics of the plasma quantity is found to show the transition from the transport-dominated state to the radiation-dominated state. (author)

A contoured gap coaxial plasma gun with injected plasma armature

Energy Technology Data Exchange (ETDEWEB)

Witherspoon, F. Douglas; Case, Andrew; Messer, Sarah J.; Bomgardner, Richard II; Phillips, Michael W.; Brockington, Samuel; Elton, Raymond [HyperV Technologies Corp., Chantilly, Virginia 20151 (United States)

2009-08-15

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

Large potential change induced by pellet injection in JIPP T-IIU tokamak plasmas

International Nuclear Information System (INIS)

Hamada, Y.; Sato, K.N.; Sakakita, H.

1995-05-01

A large, rapid change in the local plasma potential is found to be induced by off-axis hydrogen ice-pellet injection into a tokamak plasma. The polarity of the rapid change is reversed when the pellet is injected into the upper and lower halves of the poloidal plasma cross-section. This change can be interpreted as being due to the gradient-B drift of particles in the high-density plasmas of the pellet cloud, before the increase of the plasma density due to the ablation becomes uniform on the magnetic surface. (author)

A Healthy Nordic Diet Alters the Plasma Lipidomic Profile in Adults with Features of Metabolic Syndrome in a Multicenter Randomized Dietary Intervention.

Science.gov (United States)

Lankinen, Maria; Schwab, Ursula; Kolehmainen, Marjukka; Paananen, Jussi; Nygren, Heli; Seppänen-Laakso, Tuulikki; Poutanen, Kaisa; Hyötyläinen, Tuulia; Risérus, Ulf; Savolainen, Markku J; Hukkanen, Janne; Brader, Lea; Marklund, Matti; Rosqvist, Fredrik; Hermansen, Kjeld; Cloetens, Lieselotte; Önning, Gunilla; Thorsdottir, Inga; Gunnarsdottir, Ingibjorg; Åkesson, Björn; Dragsted, Lars Ove; Uusitupa, Matti; Orešič, Matej

2016-03-09

A healthy Nordic diet is associated with improvements in cardiometabolic risk factors, but the effect on lipidomic profile is not known. The aim was to investigate how a healthy Nordic diet affects the fasting plasma lipidomic profile in subjects with metabolic syndrome. Men and women (n = 200) with features of metabolic syndrome [mean age: 55 y; body mass index (in kg/m 2 ): 31.6] were randomly assigned to either a healthy Nordic (n = 104) or a control (n = 96) diet for 18 or 24 wk at 6 centers. Of the participants, 156 completed the study with plasma lipidomic measurements. The healthy Nordic diet consisted of whole grains, fruits, vegetables, berries, vegetable oils and margarines, fish, low-fat milk products, and low-fat meat. An average Nordic diet served as the control diet and included low-fiber cereal products, dairy fat-based spreads, regular-fat milk products, and a limited amount of fruits, vegetables, and berries. Lipidomic profiles were measured at baseline, week 12, and the end of the intervention (18 or 24 wk) by using ultraperformance liquid chromatography mass spectrometry. The effects of the diets on the lipid variables were analyzed with linear mixed-effects models. Data from centers with 18- or 24-wk duration were also analyzed separately. Changes in 21 plasma lipids differed significantly between the groups at week 12 (false discovery rate P Nordic diet group compared with the control group. At the end of the study, changes in lipidomic profiles did not differ between the groups. However, when the intervention lasted 24 wk, changes in 8 plasma lipids that had been identified at 12 wk, including plasmalogens, were sustained. There were no differences in changes in plasma lipids between groups with an intervention of 18 wk. By the dietary biomarker score, adherence to diet did not explain the difference in the results related to the duration of the study. A healthy Nordic diet transiently modified the plasma lipidomic profile, specifically by

Note: Interpolation for evaluation of a two-dimensional spatial profile of plasma densities at low gas pressures

International Nuclear Information System (INIS)

Oh, Se-Jin; Kim, Young-Chul; Chung, Chin-Wook

2011-01-01

An interpolation algorithm for the evaluation of the spatial profile of plasma densities in a cylindrical reactor was developed for low gas pressures. The algorithm is based on a collisionless two-dimensional fluid model. Contrary to the collisional case, i.e., diffusion fluid model, the fitting algorithm depends on the aspect ratio of the cylindrical reactor. The spatial density profile of the collisionless fitting algorithm is presented in two-dimensional images and compared with the results of the diffusion fluid model.

Sex specific differences in hepatic and plasma lipid profiles in healthy cats pre and post spaying and neutering: relationship with feline hepatic lipidosis

OpenAIRE

Valtolina, Chiara; Vaandrager, Arie B.; Favier, Robert P.; Tuohetahuntila, Maidina; Kummeling, Anne; Jeusette, Isabelle; Rothuizen, Jan; Robben, Joris H.

2017-01-01

BACKGROUND: A link between lipid metabolism and disease has been recognized in cats. Since hepatic lipidosis is a frequent disorder in cats, the aim of the current study was to evaluate liver and plasma lipid dimorphism in healthy cats and the effects of gonadectomy on lipid profiling. From six female and six male cats plasma and liver lipid profiles before and after spaying/neutering were assessed and compared to five cats (three neutered male and two spayed female) diagnosed with hepatic li...

Direct measurement of the plasma potential in the edge of ASDEX Upgrade using a self emitting probe

International Nuclear Information System (INIS)

Rohde, V.; Laux, M.; Bachmann, P.; Herrmann, A.; Weinlich, M.

1997-01-01

In this paper we present first measurements of the plasma potential close to the separatrix in ASDEX Upgrade using a self emitting tip. The probe was inserted into the edge plasma of AUG using the midplane manipulator. Assuming Maxwellian plasmas, the observations agree with the predicted voltage drop in the plasma sheath, V pl ps -V fl =2.5T e , where V pl ps is the plasma potential at the presheath boundary and V fl the floating potential. Applying this technique a rapid change of the plasma potential was observed close to the separatrix during Ohmic discharges. From the gradient we derive a radial electric field E r of about -5 kV/m close to separatrix. Further out the field strength changes sign and we find up to +7 kV/m in the SOL. (orig.)

Does creatine supplementation improve the plasma lipid profile in healthy male subjects undergoing aerobic training?

Directory of Open Access Journals (Sweden)

Scagliusi Fernanda B

2008-10-01

Full Text Available Abstract We aimed to investigate the effects of creatine (Cr supplementation on the plasma lipid profile in sedentary male subjects undergoing aerobic training. Methods Subjects (n = 22 were randomly divided into two groups and were allocated to receive treatment with either creatine monohydrate (CR (~20 g·day-1 for one week followed by ~10 g·day-1 for a further eleven weeks or placebo (PL (dextrose in a double blind fashion. All subjects undertook moderate intensity aerobic training during three 40-minute sessions per week, over 3 months. High-density lipoprotein cholesterol (HDL, low-density lipoprotein cholesterol (LDL, very low-density lipoprotein cholesterol (VLDL, total cholesterol (TC, triglyceride (TAG, fasting insulin and fasting glycemia were analyzed in plasma. Thereafter, the homeostasis model assessment (HOMA was calculated. Tests were performed at baseline (Pre and after four (Post 4, eight (Post 8 and twelve (Post 12 weeks. Results We observed main time effects in both groups for HDL (Post 4 versus Post 8; P = 0.01, TAG and VLDL (Pre versus Post 4 and Post 8; P = 0.02 and P = 0.01, respectively. However, no between group differences were noted in HDL, LDL, CT, VLDL and TAG. Additionally, fasting insulin, fasting glycemia and HOMA did not change significantly. Conclusion These findings suggest that Cr supplementation does not exert any additional effect on the improvement in the plasma lipid profile than aerobic training alone.

Observation and interpretation of topological structures in impurity ion radiation profiles from the hot plasma of a torsatron

International Nuclear Information System (INIS)

Zurro, B.; McCarthy, K.J.; Ascasibar, E.; Aragon, F.; Burgos, C.; Lopez, A.; Salas, A.

1997-01-01

Significant features have been observed in impurity ion ultraviolet line emission profiles measured on the TJ-I U torsatron using a fast-scanning detector system with good spatial resolution. These features, which consist of flats and humps, provide evidence for the existence of topological structure in the plasma interior. It is postulated that these structures arise as a result of perturbations in the electron temperature and ion density profiles caused by magnetic islands. We develop a model to show how these structures can give rise to such features in ultraviolet radiation profiles and we use theoretical iota profiles to correlate the positions of the more prominent features with rational iota values. (orig.)

Plasma confinement using biased electrode in the TCABR tokamak

International Nuclear Information System (INIS)

Nascimento, I.C.; Kuznetsov, Y.K.; Severo, J.H.F.; Fonseca, A.M.M.; Elfimov, A.; Bellintani, V.; Machida, M.; Heller, M.V.A.P.; Galvao, R.M.O.; Sanada, E.K.; Elizondo, J.I.

2005-01-01

Experimental data obtained on the TCABR tokamak (R = 0.61 m, a = 0.18 m) with an electrically polarized electrode, placed at r = 0.16 m, is reported in this paper. The experiment was performed with plasma current of 90 kA (q 3.1) and hydrogen gas injection adjusted for keeping the electron density at 1.0 x 10 19 m -3 without bias. Time evolution and radial profiles of plasma parameters with and without bias were measured. The comparison of the profiles shows an increase of the central line-averaged density, up to a maximum factor of 2.6, while H α hydrogen spectral line intensity decreases and the C III impurity stays on the same level. The analysis of temporal behaviour and radial profiles of plasma parameters indicates that the confined plasma enters the H-mode regime. The data analysis shows a maximum enhanced energy confinement factor of 1.95, decaying to 1.5 at the maximum of the density, in comparison with predicted Neo-Alcator scaling law values. Indications of transient increase of the density gradient near the plasma edge were obtained with measurements of density profiles. Calculations of turbulence and transport at the Scrape-Off-Layer, using measured floating potentials and ion saturation currents, show a strong decrease in the power spectra and transport. Bifurcation was not observed and the decrease in the saturation current occurs in 50 μs

Plasma motion in the scrape-off layer of a nonequipotential tokamak limiter

International Nuclear Information System (INIS)

Fidel'man, G.N.

1987-01-01

A theory is derived for the laminar convection of the plasma in the scrape-off layer of a poloidal limiter with a distributed potential. The plasma potential and density distributions are derived for the cases of poloidal and slightly nonuniform radial distributions of the potential on the limiter. The stability of these solutions against flute perturbations is analyzed. Criteria for the control of the density profile are derived in the models of laminar and turbulent scrape-off layers. The energy expended in sustaining the limiter potential distribution is studied. If a suitable potential distribution is selected, it is possible to obtain ∼10% of the total convective heat flux from the plasma column in the form of purely electrical energy

Existence of a virtual cathode close to a strongly electron emissive wall in low density plasmas

Science.gov (United States)

Tierno, S. P.; Donoso, J. M.; Domenech-Garret, J. L.; Conde, L.

2016-01-01

The interaction between an electron emissive wall, electrically biased in a plasma, is revisited through a simple fluid model. We search for realistic conditions of the existence of a non-monotonic plasma potential profile with a virtual cathode as it is observed in several experiments. We mainly focus our attention on thermionic emission related to the operation of emissive probes for plasma diagnostics, although most conclusions also apply to other electron emission processes. An extended Bohm criterion is derived involving the ratio between the two different electron densities at the potential minimum and at the background plasma. The model allows a phase-diagram analysis, which confirms the existence of the non-monotonic potential profiles with a virtual cathode. This analysis shows that the formation of the potential well critically depends on the emitted electron current and on the velocity at the sheath edge of cold ions flowing from the bulk plasma. As a consequence, a threshold value of the governing parameter is required, in accordance to the physical nature of the electron emission process. The latter is a threshold wall temperature in the case of thermionic electrons. Experimental evidence supports our numerical calculations of this threshold temperature. Besides this, the potential well becomes deeper with increasing electron emission, retaining a fraction of the released current which limits the extent of the bulk plasma perturbation. This noninvasive property would explain the reliable measurements of plasma potential by using the floating potential method of emissive probes operating in the so-called strong emission regime.

Existence of a virtual cathode close to a strongly electron emissive wall in low density plasmas

International Nuclear Information System (INIS)

Tierno, S. P.; Donoso, J. M.; Domenech-Garret, J. L.; Conde, L.

2016-01-01

The interaction between an electron emissive wall, electrically biased in a plasma, is revisited through a simple fluid model. We search for realistic conditions of the existence of a non-monotonic plasma potential profile with a virtual cathode as it is observed in several experiments. We mainly focus our attention on thermionic emission related to the operation of emissive probes for plasma diagnostics, although most conclusions also apply to other electron emission processes. An extended Bohm criterion is derived involving the ratio between the two different electron densities at the potential minimum and at the background plasma. The model allows a phase-diagram analysis, which confirms the existence of the non-monotonic potential profiles with a virtual cathode. This analysis shows that the formation of the potential well critically depends on the emitted electron current and on the velocity at the sheath edge of cold ions flowing from the bulk plasma. As a consequence, a threshold value of the governing parameter is required, in accordance to the physical nature of the electron emission process. The latter is a threshold wall temperature in the case of thermionic electrons. Experimental evidence supports our numerical calculations of this threshold temperature. Besides this, the potential well becomes deeper with increasing electron emission, retaining a fraction of the released current which limits the extent of the bulk plasma perturbation. This noninvasive property would explain the reliable measurements of plasma potential by using the floating potential method of emissive probes operating in the so-called strong emission regime

Existence of a virtual cathode close to a strongly electron emissive wall in low density plasmas

Energy Technology Data Exchange (ETDEWEB)

Tierno, S. P., E-mail: sp.tierno@upm.es; Donoso, J. M.; Domenech-Garret, J. L.; Conde, L. [Department of Applied Physics, E.T.S.I. Aeronáutica y del Espacio. Universidad Politécnica de Madrid, 28040 Madrid (Spain)

2016-01-15

The interaction between an electron emissive wall, electrically biased in a plasma, is revisited through a simple fluid model. We search for realistic conditions of the existence of a non-monotonic plasma potential profile with a virtual cathode as it is observed in several experiments. We mainly focus our attention on thermionic emission related to the operation of emissive probes for plasma diagnostics, although most conclusions also apply to other electron emission processes. An extended Bohm criterion is derived involving the ratio between the two different electron densities at the potential minimum and at the background plasma. The model allows a phase-diagram analysis, which confirms the existence of the non-monotonic potential profiles with a virtual cathode. This analysis shows that the formation of the potential well critically depends on the emitted electron current and on the velocity at the sheath edge of cold ions flowing from the bulk plasma. As a consequence, a threshold value of the governing parameter is required, in accordance to the physical nature of the electron emission process. The latter is a threshold wall temperature in the case of thermionic electrons. Experimental evidence supports our numerical calculations of this threshold temperature. Besides this, the potential well becomes deeper with increasing electron emission, retaining a fraction of the released current which limits the extent of the bulk plasma perturbation. This noninvasive property would explain the reliable measurements of plasma potential by using the floating potential method of emissive probes operating in the so-called strong emission regime.

Detection of an electron beam in a high density plasma via an electrostatic probe

Science.gov (United States)

Majeski, Stephen; Yoo, Jongsoo; Zweben, Stewart; Yamada, Masaaki; Ji, Hantao

2017-10-01

The perturbation in floating potential by an electron beam is detected by a 1D floating potential probe array to evaluate the use of an electron beam for magnetic field line mapping in the Magnetic Reconnection Experiment (MRX) plasma. The MRX plasma is relatively high density (1013 cm-3) and low temperature (5 eV). Beam electrons are emitted from a tungsten filament and are accelerated by a 200 V potential across the sheath. They stream along the magnetic field lines towards the probe array. The spatial electron beam density profile is assumed to be a Gaussian along the radial axis of MRX and the effective beam width is determined from the radial profile of the floating potential. The magnitude of the perturbation is in agreement with theoretical predictions and the location of the perturbation is also in agreement with field line mapping. In addition, no significant broadening of the electron beam is observed after propagation for tens of centimeters through the high density plasma. These results demonstrate that this method of field line mapping is, in principle, feasible in high density plasmas. This work is supported by the DOE Contract No. DE-AC0209CH11466.

Ionization potential depression and optical spectra in a Debye plasma model

Science.gov (United States)

Lin, Chengliang; Röpke, Gerd; Reinholz, Heidi; Kraeft, Wolf-Dietrich

2017-11-01

We show how optical spectra in dense plasmas are determined by the shift of energy levels as well as the broadening owing to collisions with the plasma particles. In lowest approximation, the interaction with the plasma particles is described by the RPA dielectric function, leading to the Debye shift of the continuum edge. The bound states remain nearly un-shifted, their broadening is calculated in Born approximation. The role of ionization potential depression as well as the Inglis-Teller effect are shown. The model calculations have to be improved going beyond the lowest (RPA) approximation when applying to WDM spectra.

Automatic emissive probe apparatus for accurate plasma and vacuum space potential measurements

Science.gov (United States)

Jianquan, LI; Wenqi, LU; Jun, XU; Fei, GAO; Younian, WANG

2018-02-01

We have developed an automatic emissive probe apparatus based on the improved inflection point method of the emissive probe for accurate measurements of both plasma potential and vacuum space potential. The apparatus consists of a computer controlled data acquisition card, a working circuit composed by a biasing unit and a heating unit, as well as an emissive probe. With the set parameters of the probe scanning bias, the probe heating current and the fitting range, the apparatus can automatically execute the improved inflection point method and give the measured result. The validity of the automatic emissive probe apparatus is demonstrated in a test measurement of vacuum potential distribution between two parallel plates, showing an excellent accuracy of 0.1 V. Plasma potential was also measured, exhibiting high efficiency and convenient use of the apparatus for space potential measurements.

Electron cooling and finite potential drop in a magnetized plasma expansion

Energy Technology Data Exchange (ETDEWEB)

Martinez-Sanchez, M. [Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Navarro-Cavallé, J. [Escuela Técnica Superior de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Ahedo, E. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Avda. Universidad 30, Leganés 28911, Madrid (Spain)

2015-05-15

The steady, collisionless, slender flow of a magnetized plasma into a surrounding vacuum is considered. The ion component is modeled as mono-energetic, while electrons are assumed Maxwellian upstream. The magnetic field has a convergent-divergent geometry, and attention is restricted to its paraxial region, so that 2D and drift effects are ignored. By using the conservation of energy and magnetic moment of particles and the quasi-neutrality condition, the ambipolar electric field and the distribution functions of both species are calculated self-consistently, paying attention to the existence of effective potential barriers associated to magnetic mirroring. The solution is used to find the total potential drop for a set of upstream conditions, plus the axial evolution of various moments of interest (density, temperatures, and heat fluxes). The results illuminate the behavior of magnetic nozzles, plasma jets, and other configurations of interest, showing, in particular, in the divergent plasma the collisionless cooling of electrons, and the generation of collisionless electron heat fluxes.

Ionization potential depression in an atomic-solid-plasma picture

Science.gov (United States)

Rosmej, F. B.

2018-05-01

Exotic solid density matter such as heated hollow crystals allow extended material studies while their physical properties and models such as the famous ionization potential depression are presently under renewed controversial discussion. Here we develop an atomic-solid-plasma (ASP) model that permits ionization potential depression studies also for single and multiple core hole states. Numerical calculations show very good agreement with recently available data not only in absolute values but also for Z-scaled properties while currently employed methods fail. For much above solid density compression, the ASP model predicts increased K-edge energies that are related to a Fermi surface rising. This is in good agreement with recent quantum molecular dynamics simulations. For hot dense matter a quantum number dependent optical electron finite temperature ion sphere model is developed that fits well with line shift and line disappearance data from dense laser produced plasma experiments. Finally, the physical transparency of the ASP picture allows a critical discussion of current methods.

The Effect of Renal Denervation on Plasma Adipokine Profile in Patients with Treatment Resistant Hypertension

Directory of Open Access Journals (Sweden)

Nina Eikelis

2017-05-01

Full Text Available Background: We previously demonstrated the effectiveness of renal denervation (RDN to lower blood pressure (BP at least partially via the reduction of sympathetic stimulation to the kidney. A number of adipocyte-derived factors are implicated in BP control in obesity.Aim: The aim of this study was to examine whether RDN may have salutary effects on the adipokine profile in patients with resistant hypertension (RH.Methods: Fifty seven patients with RH undergoing RDN program have been included in this study (65% males, age 60.8 ± 1.5 years, BMI 32.6 ± 0.7 kg/m2, mean ± SEM. Throughout the study, the patients were on an average of 4.5 ± 2.7 antihypertensive drugs. Automated seated office BP measurements and plasma concentrations of leptin, insulin, non-esterified fatty acids (NEFA, adiponectin and resistin were assessed at baseline and the 3 months after RDN.Results: There was a significant reduction in mean office systolic (168.75 ± 2.57 vs. 155.23 ± 3.17 mmHg, p < 0.001 and diastolic (90.68 ± 2.31 vs. 83.74 ± 2.36 mmHg, p < 0.001 BP 3 months after RDN. Body weight, plasma leptin and resistin levels and heart rate remained unchanged. Fasting insulin concentration significantly increased 3 months after the procedure (20.05 ± 1.46 vs. 29.70 ± 2.51 uU/ml, p = 0.002. There was a significant drop in circulating NEFA at follow up (1.01 ± 0.07 vs. 0.47 ± 0.04 mEq/l, p < 0.001. Adiponectin concentration was significantly higher after RDN (5,654 ± 800 vs. 6,644 ± 967 ng/ml, p = 0.024.Conclusions: This is the first study to demonstrate that RDN is associated with potentially beneficial effects on aspects of the adipokine profile. Increased adiponectin and reduced NEFA production may contribute to BP reduction via an effect on metabolic pathways.Clinical Trial Registration Number: NCT00483808, NCT00888433.

Investigation of tenuous plasma environment using Active Spacecraft Potential Control (ASPOC) on Magnetospheric Multiscale (MMS) Mission

Science.gov (United States)

Nakamura, Rumi; Jeszenszky, Harald; Torkar, Klaus; Andriopoulou, Maria; Fremuth, Gerhard; Taijmar, Martin; Scharlemann, Carsten; Svenes, Knut; Escoubet, Philippe; Prattes, Gustav; Laky, Gunter; Giner, Franz; Hoelzl, Bernhard

2015-04-01

The NASA's Magnetospheric Multiscale (MMS) Mission is planned to be launched on March 12, 2015. The scientific objectives of the MMS mission are to explore and understand the fundamental plasma physics processes of magnetic reconnection, particle acceleration and turbulence in the Earth's magnetosphere. The region of scientific interest of MMS is in a tenuous plasma environment where the positive spacecraft potential reaches an equilibrium at several tens of Volts. An Active Spacecraft Potential Control (ASPOC) instrument neutralizes the spacecraft potential by releasing positive charge produced by indium ion emitters. ASPOC thereby reduces the potential in order to improve the electric field and low-energy particle measurement. The method has been successfully applied on other spacecraft such as Cluster and Double Star. Two ASPOC units are present on each of the MMS spacecraft. Each unit contains four ion emitters, whereby one emitter per instrument is operated at a time. ASPOC for MMS includes new developments in the design of the emitters and the electronics enabling lower spacecraft potentials, higher reliability, and a more uniform potential structure in the spacecraft's sheath compared to previous missions. Model calculations confirm the findings from previous applications that the plasma measurements will not be affected by the beam's space charge. A perfectly stable spacecraft potential precludes the utilization of the spacecraft as a plasma probe, which is a conventional technique used to estimate ambient plasma density from the spacecraft potential. The small residual variations of the potential controlled by ASPOC, however, still allow to determine ambient plasma density by comparing two closely separated spacecraft and thereby reconstructing the uncontrolled potential variation from the controlled potential. Regular intercalibration of controlled and uncontrolled potentials is expected to increase the reliability of this new method.

A Healthy Nordic Diet Alters the Plasma Lipidomic Profile in Adults with Features of Metabolic Syndrome in a Multicenter Randomized Dietary Intervention

DEFF Research Database (Denmark)

Lankinen, Maria; Schwab, Ursula; Kolehmainen, Marjukka

2016-01-01

Background: A healthy Nordic diet is associated with improvements in cardiometabolic risk factors, but the effect on lipidomic profile is not known. Objective: The aim was to investigate how a healthy Nordic diet affects the fasting plasma lipidomic profile in subjects with metabolic syndrome. Me...

Theory of the interface between a classical plasma and a hard wall

International Nuclear Information System (INIS)

Ballone, P.; Pastore, G.; Tosi, M.P.; Trieste Univ.

1983-09-01

The interfacial density profile of a classical one-component plasma confined by a hard wall is studied in planar and spherical geometries. The approach adapts to interfacial problems a modified hypernetted-chain approximation developed by Lado and by Rosenfeld and Ashcroft for the bulk structure of simple liquids. The specific new aim is to embody self-consistently into the theory a 'contact theorem', fixing the plasma density at the wall through an equilibrium condition which involves the electrical potential drop across the interface and the bulk pressure. The theory is brought into fully quantitative contact with computer simulation data for a plasma confined in a spherical cavity of large but finite radius. It is also shown that the interfacial potential at the point of zero charge is accurately reproduced by suitably combining the contact theorem with relevant bulk properties in a simple, approximate representation of the interfacial charge density profile. (author)

Response of the plasma to the size of an anode electrode biased near the plasma potential

International Nuclear Information System (INIS)

Barnat, E. V.; Laity, G. R.; Baalrud, S. D.

2014-01-01

As the size of a positively biased electrode increases, the nature of the interface formed between the electrode and the host plasma undergoes a transition from an electron-rich structure (electron sheath) to an intermediate structure containing both ion and electron rich regions (double layer) and ultimately forms an electron-depleted structure (ion sheath). In this study, measurements are performed to further test how the size of an electron-collecting electrode impacts the plasma discharge the electrode is immersed in. This is accomplished using a segmented disk electrode in which individual segments are individually biased to change the effective surface area of the anode. Measurements of bulk plasma parameters such as the collected current density, plasma potential, electron density, electron temperature and optical emission are made as both the size and the bias placed on the electrode are varied. Abrupt transitions in the plasma parameters resulting from changing the electrode surface area are identified in both argon and helium discharges and are compared to the interface transitions predicted by global current balance [S. D. Baalrud, N. Hershkowitz, and B. Longmier, Phys. Plasmas 14, 042109 (2007)]. While the size-dependent transitions in argon agree, the size-dependent transitions observed in helium systematically occur at lower electrode sizes than those nominally derived from prediction. The discrepancy in helium is anticipated to be caused by the finite size of the interface that increases the effective area offered to the plasma for electron loss to the electrode

Quantum-Mechanical Calculation of Ionization-Potential Lowering in Dense Plasmas

Directory of Open Access Journals (Sweden)

Sang-Kil Son (손상길

2014-07-01

Full Text Available The charged environment within a dense plasma leads to the phenomenon of ionization-potential depression (IPD for ions embedded in the plasma. Accurate predictions of the IPD effect are of crucial importance for modeling atomic processes occurring within dense plasmas. Several theoretical models have been developed to describe the IPD effect, with frequently discrepant predictions. Only recently, first experiments on IPD in Al plasma have been performed with an x-ray free-electron laser, where their results were found to be in disagreement with the widely used IPD model by Stewart and Pyatt. Another experiment on Al, at the Orion laser, showed disagreement with the model by Ecker and Kröll. This controversy shows a strong need for a rigorous and consistent theoretical approach to calculate the IPD effect. Here, we propose such an approach: a two-step Hartree-Fock-Slater model. With this parameter-free model, we can accurately and efficiently describe the experimental Al data and validate the accuracy of standard IPD models. Our model can be a useful tool for calculating atomic properties within dense plasmas with wide-ranging applications to studies on warm dense matter, shock experiments, planetary science, inertial confinement fusion, and nonequilibrium plasmas created with x-ray free-electron lasers.

Dependence of ideal MHD kink and ballooning modes on plasma shape and profiles in tokamaks

International Nuclear Information System (INIS)

Todd, A.M.M.; Manickam, J.; Okabayashi, M.; Chance, M.S.; Grimm, R.C.; Greene, J.M.; Johnson, J.L.

1978-08-01

Extensive numerical studies of ideal MHD instabilities have been carried out to gain insight into the parametric dependence of critical β's in tokamaks. The large number of interrelated equilibrium quantities involved in establishing a critical β has demanded a careful, systematic survey in order to isolate this dependence. The results of this survey establish the scaling with geometrical quantities including aspect ratio, elongation, and triangularity in the parameter regimes appropriate for both current and reactor-sized plasmas. A moderate dependence on the pressure profile and a strong variation with the current profile is found. The principal result is that for aspect ratio R/a approximately equal to 3, critical β's are of the order of 2% for circular cross sections and 5% for plasmas with elongation K approximately equal to 2; somewhat higher values could be achieved with more optimal shaping. Finally, sequences of equilibria have been analyzed to compare critical β as a function of toroidal mode number n. We conclude that the infinite-n analytic ballooning theory provides a sufficient condition for ideal MHD internal mode stability. Low-n free boundary modes appear to set a lower limit

Potentials of fissioning plasmas

International Nuclear Information System (INIS)

Karlheinz, Thom.

1979-01-01

Successful experiments with the nuclear pumping of lasers have demonstrated that in gaseous medium the kinetic energy of fission fragments can be converted directly into non-equilibrium optical radiation. This confirms the concept that the fissioning medium in a gas-phase nuclear reactor shows an internal structure such as a plasma in nearly thermal equilibrium varying up to a state of extreme-non-equilibrium. The accompanying variations of temperatures, pressure and radiative spectrum suggest wide ranges of applications. For example, in the gas-phase fission reactor concept enriched uranium hexafluoride or an uranium plasma replaces conventional fuel elements and permits operation above the melting point of solid materials. This potential has been motivation for the US National Aeronautics and Space Administration (NASA) to conduct relevant research for high specific impulse propulsion in space. The need to separate the high temperature gaseous fuel from the surfaces of a containing vessel and to protect them against thermal radiation has led to the concept of an externally moderated reactor in which the fissioning gaseous material is suspended by fluid dynamic means and the flow of opaque buffer gas removes the power. The gaseous nuclear fuel can slowly be circulated through the reactor for continuous on-site reprocessing including the annihilation of transuranium actinides at fission when being fed back into the reactor. An equilibrium of the generation and destruction of such actinides at fission when being fed back into the reactor. An equilibrium of the generation and destruction of such actinides can thus be achieved. These characteristics and the unique radiative properties led to the expectation that the gas-phase fission reactor could feature improved safety, safeguarding and economy, in addition to new technologies such as processing, photochemistry and the transmission of power over large distances in space

Resistive evolution of current profile in tokamaks, application to the optimization of Tore-supra plasma discharges; Evolution resistive du profil de courant dans les Tokamaks, application a l'optimisation des decharges de Tore Supra

Energy Technology Data Exchange (ETDEWEB)

Bregeon, R

1999-03-01

In Tokamak plasma physics, current profile shaping has now become a key issue to improve the confinement properties of the plasma discharge. The objective of this work is to study the processes governing the current diffusion when non-inductive current are playing a major role in the discharge. Ultimately, this study aims to identify the key parameters to control the plasma current density profile with external current drive heating systems such as Lower Hybrid Current drive (LHCD) or self generated current drive such as the bootstrap current. Principles of non inductive current drive and heating systems are introduced as well as bootstrap current mechanisms. Then we present the experimental study of plasma parallel electric conductivity to validate existing models. Using these results, the poloidal magnetic field flux diffusion is modelled, using toroidal co-ordinates in order to give an accurate description of the current density profiles evolution. The initial and boundary conditions required for numerical resolution of the diffusion equation are also presented. Finally, we conclude this work with the simulations of two discharges: one with Fast Wave Electron Heating and the second using Lower Hybrid Current Drive. These simulations have multiples aims: validity test of our numerical tool and to show some limits of cylindrical models. Test of electric conductivity and bootstrap current models. To identify the key parameters involved in the current diffusion processes of a high performance plasma discharge on Tore Supra. Such simulations are crucial to determine the amount of non-inductive current required to control and sustain long plasma discharges in steady state. (author)

Cold atmospheric plasma as a potential tool for multiple myeloma treatment

Science.gov (United States)

Cui, Qingjie; Liu, Dingxin; Liu, Zhijie; Wang, Xiaohua; Yang, Yanjie; Feng, Miaojuan; Liang, Rong; Chen, Hailan; Ye, Kai; Kong, Michael G.

2018-01-01

Multiple myeloma (MM) is a fatal and incurable hematological malignancy thus new therapy need to be developed. Cold atmospheric plasma, a new technology that could generate various active species, could efficiently induce various tumor cells apoptosis. More details about the interaction of plasma and tumor cells need to be addressed before the application of gas plasma in clinical cancer treatment. In this study, we demonstrate that He+O2 plasma could efficiently induce myeloma cell apoptosis through the activation of CD95 and downstream caspase cascades. Extracellular and intracellular reactive oxygen species (ROS) accumulation is essential for CD95-mediated cell apoptosis in response to plasma treatment. Furthermore, p53 is shown to be a key transcription factor in activating CD95 and caspase cascades. More importantly, we demonstrate that CD95 expression is higher in tumor cells than in normal cells in both MM cell lines and MM clinical samples, which suggests that CD95 could be a favorable target for plasma treatment as it could selectively inactivate myeloma tumor cells. Our results illustrate the molecular details of plasma induced myeloma cell apoptosis and it shows that gas plasma could be a potential tool for myeloma therapy in the future. PMID:29719586

On the atomic line profiles in high pressure plasmas

Energy Technology Data Exchange (ETDEWEB)

Janssen, J. F. J.; Gnybida, M.; Rijke, A. J.; Dijk, J. van [Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Suijker, J. L. G. [Philips Lighting R and D Category Professional Lamps, P.O. Box 80020, 5600 JM Eindhoven (Netherlands)

2013-11-14

In a previous contribution to this journal [H. P. Stormberg, J. Appl. Phys. 51(4), 1963 (1980)], Stormberg presented an analytical expression for the convolution of Lorentz and Levy line profiles, which models atomic radiative transitions in high pressure plasmas. Unfortunately, the derivations are flawed with errors and the final expression, while correct, is accompanied by misguiding comments about the meaning of the symbols used therein, in particular the “complex error function.” In this paper, we discuss the broadening mechanisms that give rise to Stormberg's model and present a correct derivation of his final result. We will also provide an alternative expression, based on the Faddeeva function, which has decisive computational advantages and emphasizes the real-valuedness of the result. The MATLAB/Octave scripts of our implementation have been made available on the publisher's website for future reference.

Effects of Dietary Lycopene Supplementation on Plasma Lipid Profile, Lipid Peroxidation and Antioxidant Defense System in Feedlot Bamei Lamb.

Science.gov (United States)

Jiang, Hongqin; Wang, Zhenzhen; Ma, Yong; Qu, Yanghua; Lu, Xiaonan; Luo, Hailing

2015-07-01

Lycopene, a red non-provitamin A carotenoid, mainly presenting in tomato and tomato byproducts, has the highest antioxidant activity among carotenoids because of its high number of conjugated double bonds. The objective of this study was to investigate the effect of lycopene supplementation in the diet on plasma lipid profile, lipid peroxidation and antioxidant defense system in feedlot lamb. Twenty-eight Bamei male lambs (90 days old) were divided into four groups and fed a basal diet (LP0, 40:60 roughage: concentrate) or the basal diet supplemented with 50, 100, and 200 mg/kg lycopene. After 120 days of feeding, all lambs were slaughtered and sampled. Dietary lycopene supplementation significantly reduced the levels of plasma total cholesterol (p0.05). The levels of TG (pCAT, pCAT (p<0.05, linearly) and SOD (p<0.001, linearly). Therefore, it was concluded that lycopene supplementation improved the antioxidant status of the lamb and optimized the plasma lipid profile, the dosage of 200 mg lycopene/kg feed might be desirable for growing lambs to prevent environment stress and maintain normal physiological metabolism.

A fast spatial scanning combination emissive and mach probe for edge plasma diagnosis

International Nuclear Information System (INIS)

Lehmer, R.D.; LaBombard, B.; Conn, R.W.

1989-04-01

A fast spatially scanning emissive and mach probe has been developed for the measurement of plasma profiles in the PISCES facility at UCLA. A pneumatic cylinder is used to drive a multiple tip probe along a 15cm stroke in less than 400msec, giving single shot profiles while limiting power deposition to the probe. A differentially pumped sliding O-ring seal allows the probe to be moved between shots to infer two and three dimensional profiles. The probe system has been used to investigate the plasma potential, density, and parallel mach number profiles of the presheath induced by a wall surface and scrape-off-layer profile modifications in biased limiter simulation experiments. Details of the hardware, data acquisition electronics, and tests of probe reliability are discussed. 30 refs., 24 figs

Te and ne profiles on JFT-2M plasma with the highest spatial resolution TV Thomson scattering system

International Nuclear Information System (INIS)

Yamauchi, T.

1993-01-01

A high spatial resolution TV Thomson scattering system was constructed on JFT-2M tokamak. This system is similar to those used at PBX-M and TFTR. These systems are providing complete profiles of Te and ne at a single time during a plasma discharge. The characteristics of JFT-2M TVTS are as follows: 1. Measured points are composed of not only 81 points for the scattered light and plasma light, whose time difference is 2 ms, but also 10 points for plasma light measured at the same time with scattered light. 2. Spatial resolution is 0.86 cm, which is higher than any other Thomson scattering system. 3. Sensitivity of detector composed of image intensifier tubes and CCD is as high as that of photomultiplier tube. Te and ne profiles have been measured over one year on JFT-2M. The line-averaged electron density measured was in the region of 5x10 12 cm -3 - 7x10 13 cm -3 and the measured electron temperature was in the region of 50 eV -1.2 keV. (author) 7 refs., 7 figs., 1 tab

Modeling plasma behavior in a plasma electrode Pockels cell

International Nuclear Information System (INIS)

Boley, C.D.; Rhodes, M.A.

1999-01-01

The authors present three interrelated models of plasma behavior in a plasma electrode Pockels cell (PEPC). In a PEPC, plasma discharges are formed on both sides of a thin, large-aperture electro-optic crystal (typically KDP). The plasmas act as optically transparent, highly conductive electrodes, allowing uniform application of a longitudinal field to induce birefringence in the crystal. First, they model the plasma in the thin direction, perpendicular to the crystal, via a one-dimensional fluid model. This yields the electron temperature and the density and velocity profiles in this direction as functions of the neutral pressure, the plasma channel width, and the discharge current density. Next, they model the temporal response of the crystal to the charging process, combining a circuit model with a model of the sheath which forms near the crystal boundary. This model gives the time-dependent voltage drop across the sheath as a function of electron density at the sheath entrance. Finally, they develop a two-dimensional MHD model of the planar plasma, in order to calculate the response of the plasma to magnetic fields. They show how the plasma uniformity is affected by the design of the current return, by the longitudinal field from the cathode magnetron, and by fields from other sources. This model also gives the plasma sensitivity to the boundary potential at which the top and bottom of the discharge are held. They validate these models by showing how they explain observations in three large Pockels cells built at Lawrence Livermore National Laboratory

A Plasma Diagnostic Set for the Study of a Variable Specific Impulse Magnetoplasma Rocket

Science.gov (United States)

Squire, J. P.; Chang-Diaz, F. R.; Bengtson Bussell, R., Jr.; Jacobson, V. T.; Wootton, A. J.; Bering, E. A.; Jack, T.; Rabeau, A.

1997-11-01

The Advanced Space Propulsion Laboratory (ASPL) is developing a Variable Specific Impulse Magnetoplasma Rocket (VASIMR) using an RF heated magnetic mirror operated asymmetrically. We will describe the initial set of plasma diagnostics and data acquisition system being developed and installed on the VASIMR experiment. A U.T. Austin team is installing two fast reciprocating probes: a quadruple Langmuir and a Mach probe. These measure electron density and temperature profiles, electrostatic plasma fluctuations, and plasma flow profiles. The University of Houston is developing an array of 20 highly directional Retarding Potential Analyzers (RPA) for measuring ion energy distribution function profiles in the rocket plume, giving a measurement of total thrust. We have also developed a CAMAC based data acquisition system using LabView running on a Power Macintosh communicating through a 2 MB/s serial highway. We will present data from initial plasma operations and discuss future diagnostic development.

Structural instability of sheath potential distribution and its possible implications for the L/H transition in tokamak plasmas

International Nuclear Information System (INIS)

Yoshida, Zensho; Yamada, Hiroshi.

1988-07-01

The Bohm equation of electrostatic potential distributions in one-dimensional plasmas has been studied for various Mach numbers and plasma potentials. Solvability and structural stability have been discussed using the Sagdeev potential. Implications of the structural stability for the L/H transitions in tokamak plasmas has been also discussed. (author)

Boron profiles in doped amorphous-silicon solar cells formed by plasma ion deposition

International Nuclear Information System (INIS)

Stoddart, C.T.H.; Hunt, C.P.; Coleman, J.H.

1979-01-01

Amorphous silicon p-n junction solar cells of large area (100 cm 2 ) and having a quantum efficiency approaching 100% in the blue region have been prepared by plasma ion-plating, the p layer being formed from diborane and silane gases in a cathode glow-discharge. Surface secondary ion mass spectrometry combined with ion beam etching was found to be a very sensitive method with high in-depth resolution for obtaining the initial boron-silicon profile of the solar cell p-n junction. (author)

An extra contribution to the Mikheyev-Smirnov-Wolfenstein potential in a CP-nonsymmetric plasma

International Nuclear Information System (INIS)

Horvat, R.

1991-01-01

Owing to matter-induced electromagnetic properties of neutrinos, v L e - → v L e - electromagnetic scattering in a plasma becomes possible even in the standard model with massless left-handed neutrinos. Electric-charge screening in a plasma causes the contribution to the external potential for a left-handed neutrino field to be the same as the ordinary Mikheyev-Smirnov-Wolfenstein potential. (orig.)

Analytical solutions and particle simulations of cross-field plasma sheaths

International Nuclear Information System (INIS)

Gerver, M.J.; Parker, S.E.; Theilhaber, K.

1989-01-01

Particles simulations have been made of an infinite plasma slab, bounded by absorbing conducting walls, with a magnetic field parallel to the walls. The simulations have been either 1-D, or 2-D, with the magnetic field normal to the simulation plane. Initially, the plasma has a uniform density between the walls, and there is a uniform source of ions and electrons to replace particles lost to the walls. In the 1-D case, there is no diffusion of the particle guiding centers, and the plasma remains uniform in density and potential over most of the slab, with sheaths about a Debye length wide where the potential rises to the wall potential. In the 2-D case, the density profile becomes parabolic, going almost to zero at the walls, and there is a quasineutral presheath in the bulk of the plasma, in addition to sheaths near the walls. Analytic expressions are found for the density and potential profiles in both cases, including, in the 2-D case, the magnetic presheath due to finite ion Larmor radius, and the effects of the guiding center diffusion rate being either much less than or much grater than the energy diffusion rate. These analytic expressions are shown to agree with the simulations. A 1-D simulation with Monte Carlo guiding center diffusion included gives results that are good agreement with the much more expensive 2-D simulation. 17 refs., 10 figs

Calculation of the non-inductive current profile in high-performance NSTX plasmas

Science.gov (United States)

Gerhardt, S. P.; Fredrickson, E.; Gates, D.; Kaye, S.; Menard, J.; Bell, M. G.; Bell, R. E.; Le Blanc, B. P.; Kugel, H.; Sabbagh, S. A.; Yuh, H.

2011-03-01

The constituents of the current profile have been computed for a wide range of high-performance plasmas in NSTX (Ono et al 2000 Nucl. Fusion 40 557); these include cases designed to maximize the non-inductive fraction, pulse length, toroidal-β or stored energy. In the absence of low-frequency MHD activity, good agreement is found between the reconstructed current profile and that predicted by summing the independently calculated inductive, pressure-driven and neutral beam currents, without the need to invoke any anomalous beam ion diffusion. Exceptions occur, for instance, when there are toroidal Alfvén eigenmode avalanches or coupled m/n = 1/1 + 2/1 kink-tearing modes. In these cases, the addition of a spatially and temporally dependent fast-ion diffusivity can reduce the core beam current drive, restoring agreement between the reconstructed profile and the summed constituents, as well as bringing better agreement between the simulated and measured neutron emission rate. An upper bound on the fast-ion diffusivity of ~0.5-1 m2 s-1 is found in 'MHD-free' discharges, based on the neutron emission, the time rate of change in the neutron signal when a neutral beam is stepped and reconstructed on-axis current density.

Calculation of the Non-Inductive Current Profile in High-Performance NSTX Plasmas

International Nuclear Information System (INIS)

Gerhardt, S.P.; Fredrickson, E.; Gates, D.; Kaye, S.; Menard, J.; Bell, M.G.; Bell, R.E.; Le Blanc, B.P.; Kugel, H.; Sabbagh, S.A.; Yuh, H.

2011-01-01

The constituents of the current profile have been computed for a wide range of high-performance plasmas in NSTX [M. Ono, et al., Nuclear Fusion 40, 557 (2000)]; these include cases designed to maximize the non-inductive fraction, pulse length, toroidal-β, or stored energy. In the absence of low-frequency MHD activity, good agreement is found between the reconstructed current profile and that predicted by summing the independently calculated inductive, pressure-driven, and neutral beam currents, without the need to invoke any anomalous beam ion diffusion. Exceptions occur, for instance, when there are toroidal Alfven eigenmode avalanches or coupled m/n=1/1+2/1 kink-tearing modes. In these cases, the addition of a spatially and temporally dependent fast ion diffusivity can reduce the core beam current drive, restoring agreement between the reconstructed profile and the summed constituents, as well as bringing better agreement between the simulated and measured neutron emission rate. An upper bound on the fast ion diffusivity of ∼0.5-1 m 2 /sec is found in 'MHD-free' discharges, based on the neutron emission, time rate of change of the neutron signal when a neutral beam is stepped, and reconstructed on-axis current density.

Electron temperature profiles in high power neutral-beam-heated TFTR [Tokamak Fusion Test Reactor] plasmas

International Nuclear Information System (INIS)

Taylor, G.; Grek, B.; Stauffer, F.J.; Goldston, R.J.; Fredrickson, E.D.; Wieland, R.M.; Zarnstorff, M.C.

1987-09-01

In 1986, the maximum neutral beam injection (NBI) power in the Tokamak Fusion Test Reactor (TFTR) was increased to 20 MW, with three beams co-parallel and one counter-parallel to I/sub p/. TFTR was operated over a wide range of plasma parameters; 2.5 19 19 m -3 . Data bases have been constructed with over 600 measured electron temperature profiles from multipoint TV Thomson scattering which span much of this parameter space. We have also examined electron temperature profile shapes from electron cyclotron emission at the fundamental ordinary mode and second harmonic extraordinary mode for a subset of these discharges. In the light of recent work on ''profile consistency'' we have analyzed these temperature profiles in the range 0.3 < (r/a) < 0.9 to determine if a profile shape exists which is insensitive to q/sub cyl/ and beam-heating profile. Data from both sides of the temperature profile [T/sub e/(R)] were mapped to magnetic flux surfaces [T/sub e/(r/a)]. Although T/sub e/(r/a), in the region where 0.3 < r/a < 0.9 was found to be slightly broader at lower q/sub cyl/, it was found to be remarkably insensitive to β/sub p/, to the fraction of NBI power injected co-parallel to I/sub p/, and to the heating profile going from peaked on axis, to hollow. 10 refs., 8 figs

Plasma screening effects on the energies of hydrogen atom under the influence of velocity-dependent potential

International Nuclear Information System (INIS)

Bahar, M. K.

2014-01-01

In order to examine the plasma screening and velocity-dependent potential effects on the hydrogen atom, the Schrödinger equation including a more general exponential cosine screened Coulomb and velocity-dependent potential is solved numerically in the framework asymptotic iteration method. The more general exponential cosine screened Coulomb potential is used to model Debye and quantum plasma for the specific values of the parameters in its structure. However, in order to examine effects of velocity-dependent potential on energy values of hydrogen atom in Debye and quantum plasma, the isotropic form factor of velocity-dependent potential is given as harmonic oscillator type, ρ(r)=ρ o r 2 . Then, the energies of s and p states are calculated numerically without any approximation. In order to investigate thoroughly plasma screening effects and contribution of velocity-dependent potential on energy values of hydrogen atom, the corresponding calculations are carried out by using different values of parameters of more general exponential cosine screened Coulomb potential and isotropic dependence, results of which are discussed

The Effect of Ramadan Fasting and Weight-Lifting Training on Plasma Volume, Glucose and Lipids Profile of Male Weight-Lifters

Directory of Open Access Journals (Sweden)

Seyed Morteza Tayebi

Full Text Available Objective(sThe purpose of the present study was to evaluate the effect of Ramadan fasting and weight-lifting training on plasma volume, glucose, and lipids profile of male weight-lifter.Materials and MethodsForty male weight-lifters were recruited and divided into 4 groups (n=10 each and as the following groups: control (C, fasting (F, training (T and fasting-training (F-T. The T and F-T groups performed weight-lifting technique trainings and hypertrophy body building (3 sessions/week, 90 min/session. All subjects were asked to complete a medical examination as well as a medical questionnaire to ensure that they were not taking any medication, were free of cardiac, respiratory, renal, and metabolic diseases, and were not using steroids. Blood samples were taken at 24 hr before and 24 hr after one month of fasting and weight-lifting exercise. The plasma volume, fasting blood sugar (FBS, lipid profiles, and lipoproteins were analyzed in blood samples. ResultsBody weight and plasma volume showed significant (P< 0.05 decrease and increase in the F group (P< 0.05 respectively. Also, a significant reduction was observed in F-T group body weight (P< 0.01. A significant increase was found in FBS level of F group (P< 0.05. The lipid profiles and lipoproteins didn’t change significantly in C, F, T and the F-T groups.ConclusionThe effect of Ramadan fasting on body weight and plasma volumes may be closely related to the nutritional diet or biochemical response to fasting.

Spectral line profiles in weakly turbulent plasmas

International Nuclear Information System (INIS)

Capes, H.; Voslamber, D.

1976-07-01

The unified theory of line broadening by electron perturbers is generalized to include the case of a weakly turbulent plasma. The collision operator in the line shape expression is shown to be the sum of two terms, both containing effects arising from the non-equilibrium nature of the plasma. One of the two terms represents the influence of individual atom-particle interactions occuring via the nonequilibrium dielectric plasma medium. The other term is due to the interaction of the atom with the turbulent waves. Both terms contain damping and diffusion effects arising from the plasma turbulence

LC-QTOF/MS metabolomic profiles in human plasma after a 5-week high dietary fiber intake

DEFF Research Database (Denmark)

Johansson-Persson, Anna; Barri, Thaer; Ulmius, Matilda

2013-01-01

, in a 5-week randomized controlled crossover intervention. The HF diet consisted of oat bran, rye bran, and sugar beet fiber incorporated into test food products, whereas the LF diet was made of equivalent food products to the HF diet, but without adding fibers. Blood plasma samples were collected......The objective was to investigate the alterations of plasma metabolome profiles to identify exposure and effect markers of dietary fiber intake. Subjects (n¿=¿25) aged 58.6 (1.1)¿years (mean and SD) with a body mass index of 26.6 (0.5)¿kg/m(2) were given a high fiber (HF) and a low fiber (LF) diet...

Analysis of hepatic transcript profile and plasma lipid profile in early lactating dairy cows fed grape seed and grape marc meal extract.

Science.gov (United States)

Gessner, Denise K; Winkler, Anne; Koch, Christian; Dusel, Georg; Liebisch, Gerhard; Ringseis, Robert; Eder, Klaus

2017-03-23

It was recently reported that dairy cows fed a polyphenol-rich grape seed and grape marc meal extract (GSGME) during the transition period had an increased milk yield, but the underlying reasons remained unclear. As polyphenols exert a broad spectrum of metabolic effects, we hypothesized that feeding of GSGME influences metabolic pathways in the liver which could account for the positive effects of GSGME in dairy cows. In order to identify these pathways, we performed genome-wide transcript profiling in the liver and lipid profiling in plasma of dairy cows fed GSGME during the transition period at 1 week postpartum. Transcriptomic analysis of the liver revealed 207 differentially expressed transcripts, from which 156 were up- and 51 were down-regulated, between cows fed GSGME and control cows. Gene set enrichment analysis of the 155 up-regulated mRNAs showed that the most enriched gene ontology (GO) biological process terms were dealing with cell cycle regulation and the most enriched Kyoto Encyclopedia of Genes and Genomes pathways were p53 signaling and cell cycle. Functional analysis of the 43 down-regulated mRNAs revealed that a great part of these genes are involved in endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) and inflammatory processes. Accordingly, protein folding, response to unfolded protein, unfolded protein binding, chemokine activity and heat shock protein binding were identified as one of the most enriched GO biological process and molecular function terms assigned to the down-regulated genes. In line with the transcriptomics data the plasma concentrations of the acute phase proteins serum amyloid A (SAA) and haptoglobin were reduced in cows fed GSGME compared to control cows. Lipidomic analysis of plasma revealed no differences in the concentrations of individual species of major and minor lipid classes between cows fed GSGME and control cows. Analysis of hepatic transcript profile in cows fed GSGME during the

Investigation of RF-enhanced plasma potentials on Alcator C-Mod

International Nuclear Information System (INIS)

Ochoukov, R.; Whyte, D.G.; Brunner, D.; Cziegler, I.; LaBombard, B.; Lipschultz, B.; Myra, J.; Terry, J.; Wukitch, S.

2013-01-01

Radio frequency (RF) sheath rectification is a leading mechanism suspected of causing anomalously high erosion of plasma facing materials in RF-heated plasmas on Alcator C-Mod. An extensive experimental survey of the plasma potential (Φ P ) in RF-heated discharges on C-Mod reveals that significant Φ P enhancement (>100 V) is found on outboard limiter surfaces, both mapped and not mapped to active RF antennas. Surfaces that magnetically map to active RF antennas show Φ P enhancement that is, in part, consistent with the recently proposed slow wave rectification mechanism. Surfaces that do not map to active RF antennas also experience significant Φ P enhancement, which strongly correlates with the local fast wave intensity. In this case, fast wave rectification is a leading candidate mechanism responsible for the observed enhancement

Characteristics of dust voids in a strongly coupled laboratory dusty plasma

Science.gov (United States)

Bailung, Yoshiko; Deka, T.; Boruah, A.; Sharma, S. K.; Pal, A. R.; Chutia, Joyanti; Bailung, H.

2018-05-01

A void is produced in a strongly coupled dusty plasma by inserting a cylindrical pin (˜0.1 mm diameter) into a radiofrequency discharge argon plasma. The pin is biased externally below the plasma potential to generate the dust void. The Debye sheath model is used to obtain the sheath potential profile and hence to estimate the electric field around the pin. The electric field force and the ion drag force on the dust particles are estimated and their balance accounts well for the maintenance of the size of the void. The effects of neutral density as well as dust density on the void size are studied.

MICROWAVE INTERACTIONS WITH INHOMOGENEOUS PARTIALLY IONIZED PLASMA

Energy Technology Data Exchange (ETDEWEB)

Kritz, A. H.

1962-11-15

Microwave interactions with inhomogeneous plasmas are often studied by employing a simplified electromagnetic approach, i.e., by representing the effects of the plasma by an effective dielectric coefficient. The problems and approximations associated with this procedure are discussed. The equation describing the microwave field in an inhomogeneous partially ionized plasma is derived, and the method that is applied to obtain the reflected, transmitted, and absorbed intensities in inhomogeneous plasmas is presented. The interactions of microwaves with plasmas having Gaussian electron density profiles are considered. The variation of collision frequency with position is usually neglected. In general, the assumption of constant collision frequency is not justified; e.g., for a highly ionized plasma, the electron density profile determines, in part, the profile of the electron-ion collision frequency. The effect of the variation of the collision frequency profile on the interaction of microwaves with inhomogeneous plasmas is studied in order to obtain an estimate of the degree of error that may result when constant collision frequency is assumed instead of a more realistic collision frequency profile. It is shown that the degree of error is of particular importance when microwave analysis is used as a plasma diagnostic. (auth)

Drift waves and counter rotating vortices in pair-ion plasmas

Energy Technology Data Exchange (ETDEWEB)

Haque, Q., E-mail: qamar_haque@hotmail.co [Theoretical Plasma Physics Division, PINSTECH P.O. Nilore, Islamabad (Pakistan)

2010-07-19

Linear dispersion relation has been found for drift and acoustic waves in pair-ion-electron plasmas. The stationary solution in the form of counter rotating vortices has been obtained in the presence of equilibrium potential profile. It is noticed that the speed of nonlinear structures is reduced with the increase of electrons concentration in pair-ion plasmas. Linear instability condition has also been found in the presence of shear flow. It is pointed out that the present results can be useful for future pair-ion plasma experiments.

Chronic Exercise Reduces CETP and Mesterolone Treatment Counteracts Exercise Benefits on Plasma Lipoproteins Profile: Studies in Transgenic Mice.

Science.gov (United States)

Casquero, Andrea Camargo; Berti, Jairo Augusto; Teixeira, Laura Lauand Sampaio; de Oliveira, Helena Coutinho Franco

2017-12-01

Regular exercise and anabolic androgenic steroids have opposing effects on the plasma lipoprotein profile and risk of cardio-metabolic diseases in humans. Studies in humans and animal models show conflicting results. Here, we used a mice model genetically modified to mimic human lipoprotein profile and metabolism. They under-express the endogenous LDL receptor gene (R1) and express a human transgene encoding the cholesteryl ester transfer protein (CETP), normally absent in mice. The present study was designed to evaluate the independent and interactive effects of testosterone supplementation, exercise training and CETP expression on the plasma lipoprotein profile and CETP activity. CETP/R1 and R1 mice were submitted to a 6-week swimming training and mesterolone (MEST) supplementation in the last 3 weeks. MEST treatment increased markedly LDL levels (40%) in sedentary CETP/R1 mice and reduced HDL levels in exercised R1 mice (18%). A multifactorial ANOVA revealed the independent effects of each factor, as follows. CETP expression reduced HDL (21%) and increased non-HDL (15%) fractions. MEST treatment increased the VLDL concentrations (42%) regardless of other interventions. Exercise training reduced triacylglycerol (25%) and free fatty acids (20%), increased both LDL and HDL (25-33%), and reduced CETP (19%) plasma levels. Significant factor interactions showed that the increase in HDL induced by exercise is explained by reducing CETP activity and that MEST blunted the exercise-induced elevation of HDL-cholesterol. These results reinforce the positive metabolic effects of exercise, resolved a controversy about CETP response to exercise and evidenced MEST potency to counteract specific exercise benefits.

Metabolomic Profiling of Plasma from Patients with Tuberculosis by Use of Untargeted Mass Spectrometry Reveals Novel Biomarkers for Diagnosis.

Science.gov (United States)

Lau, Susanna K P; Lee, Kim-Chung; Curreem, Shirly O T; Chow, Wang-Ngai; To, Kelvin K W; Hung, Ivan F N; Ho, Deborah T Y; Sridhar, Siddharth; Li, Iris W S; Ding, Vanessa S Y; Koo, Eleanor W F; Wong, Chi-Fong; Tam, Sidney; Lam, Ching-Wan; Yuen, Kwok-Yung; Woo, Patrick C Y

2015-12-01

Although tuberculosis (TB) is a reemerging disease that affects people in developing countries and immunocompromised populations in developed countries, the current diagnostic methods are far from optimal. Metabolomics is increasingly being used for studies on infectious diseases. We performed metabolome profiling of plasma samples to identify potential biomarkers for diagnosing TB. We compared the plasma metabolome profiles of TB patients (n = 46) with those of community-acquired pneumonia (CAP) patients (n = 30) and controls without active infection (n = 30) using ultrahigh-performance liquid chromatography-electrospray ionization-quadrupole time of flight mass spectrometry (UHPLC-ESI-QTOFMS). Using multivariate and univariate analyses, four metabolites, 12R-hydroxy-5Z,8Z,10E,14Z-eicosatetraenoic acid [12(R)-HETE], ceramide (d18:1/16:0), cholesterol sulfate, and 4α-formyl-4β-methyl-5α-cholesta-8-en-3β-ol, were identified and found to have significantly higher levels in TB patients than those in CAP patients and controls. In a comparison of TB patients and controls, the four metabolites demonstrated area under the receiver operating characteristic curve (AUC) values of 0.914, 0.912, 0.905, and 0.856, sensitivities of 84.8%, 84.8%, 87.0%, and 89.1%, specificities of 90.0%, 86.7%, 86.7%, and 80.0%, and fold changes of 4.19, 26.15, 6.09, and 1.83, respectively. In a comparison of TB and CAP patients, the four metabolites demonstrated AUC values of 0.793, 0.717, 0.802, and 0.894, sensitivities of 89.1%, 71.7%, 80.4%, and 84.8%, specificities of 63.3%, 66.7%, 70.0%, and 83.3%, and fold changes of 4.69, 3.82, 3.75, and 2.16, respectively. 4α-Formyl-4β-methyl-5α-cholesta-8-en-3β-ol combined with 12(R)-HETE or cholesterol sulfate offered ≥70% sensitivity and ≥90% specificity for differentiating TB patients from controls or CAP patients. These novel plasma biomarkers, especially 12(R)-HETE and 4α-formyl-4β-methyl-5α-cholesta-8-en-3β-ol, alone or in

Observation of floating potential asymmetry in the edge plasma of ...

Indian Academy of Sciences (India)

Floating potential; vertical magnetic field; vertical electric field reversal; vertical electric field reversal ... Similar exchange of behavior for bottom probe of figure 1 with top probe of ... In our case rate of rise of plasma currents and also the total ...

Plasma potential in a magnetic mirror with electron-cyclotron-resonance heating

International Nuclear Information System (INIS)

Smith, P.K.

1983-01-01

Experimental and theoretical studies of the ECRH plasma in the University of Wisconsin DE Machine magnetic mirror have been undertaken. Typical plasma parameters in these experiments were T/sub e/ - 10 to 30 eV, T/sub i/ - 4 eV, V/sub po/ (plasma potential at midplane) - 20 to 50 V, midplane plasma density n 0 - 10 16 m - 3 , B 0 (magnetic field strength on axis at midplane) - .005 to .01 T, mirror ratio R - 5 to 20. The principal experimental findings were the appearance of strong density peaks (approx. 2 x background) and notable V/sub f/ dips (approx. kT/sub e//e) in a narrow (approx. 1 cm) region near the axial positions of cyclotron resonance. The properties of these dips do not change greatly over the range of operating parameters, but are narrower at higher pressures

Profiling of tryptophan-related plasma indoles in patients with carcinoid tumors by automated, on-line, solid-phase extraction and HPLC with fluorescence detection

NARCIS (Netherlands)

Kema, IP; Meijer, WG; Meiborg, G; Ooms, B; Willemse, PHB; de Vries, EGE

2001-01-01

Background: Profiling of the plasma indoles tryptophan, 5-hydroxytryptophan (5-HTP), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) is useful in the diagnosis and follow-up of patients with carcinoid tumors. We describe an automated method for the profiling of these indoles in protein-containing

Pulsed high-density plasmas for advanced dry etching processes

International Nuclear Information System (INIS)

Banna, Samer; Agarwal, Ankur; Cunge, Gilles; Darnon, Maxime; Pargon, Erwine; Joubert, Olivier

2012-01-01

Plasma etching processes at the 22 nm technology node and below will have to satisfy multiple stringent scaling requirements of microelectronics fabrication. To satisfy these requirements simultaneously, significant improvements in controlling key plasma parameters are essential. Pulsed plasmas exhibit considerable potential to meet the majority of the scaling challenges, while leveraging the broad expertise developed over the years in conventional continuous wave plasma processing. Comprehending the underlying physics and etching mechanisms in pulsed plasma operation is, however, a complex undertaking; hence the full potential of this strategy has not yet been realized. In this review paper, we first address the general potential of pulsed plasmas for plasma etching processes followed by the dynamics of pulsed plasmas in conventional high-density plasma reactors. The authors reviewed more than 30 years of academic research on pulsed plasmas for microelectronics processing, primarily for silicon and conductor etch applications, highlighting the potential benefits to date and challenges in extending the technology for mass-production. Schemes such as source pulsing, bias pulsing, synchronous pulsing, and others in conventional high-density plasma reactors used in the semiconductor industry have demonstrated greater flexibility in controlling critical plasma parameters such as ion and radical densities, ion energies, and electron temperature. Specifically, plasma pulsing allows for independent control of ion flux and neutral radicals flux to the wafer, which is key to eliminating several feature profile distortions at the nanometer scale. However, such flexibility might also introduce some difficulty in developing new etching processes based on pulsed plasmas. Therefore, the main characteristics of continuous wave plasmas and different pulsing schemes are compared to provide guidelines for implementing different schemes in advanced plasma etching processes based on

Transport barriers in plasmas

International Nuclear Information System (INIS)

Caldas, I L; Szezech, J D Jr; Kroetz, T; Marcus, F A; Roberto, M; Viana, R L; Lopes, S R

2012-01-01

We discuss the creation of transport barriers in magnetically confined plasmas with non monotonic equilibrium radial profiles. These barriers reduce the transport in the shearless region (i.e., where the twist condition does not hold). For the chaotic motion of particles in an equilibrium electric field with a nonmonotonic radial profile, perturbed by electrostatic waves, we show that a nontwist transport barrier can be created in the plasma by modifying the electric field radial profile. We also show non twist barriers in chaotic magnetic field line transport in the plasma near to the tokamak wall with resonant modes due to electric currents in external coils.

Profiling of tryptophan-related plasma indoles in patients with carcinoid tumors by automated, on-line, solid-phase extraction and HPLC with fluorescence detection.

Science.gov (United States)

Kema, I P; Meijer, W G; Meiborg, G; Ooms, B; Willemse, P H; de Vries, E G

2001-10-01

Profiling of the plasma indoles tryptophan, 5-hydroxytryptophan (5-HTP), serotonin, and 5-hydroxyindoleacetic acid (5-HIAA) is useful in the diagnosis and follow-up of patients with carcinoid tumors. We describe an automated method for the profiling of these indoles in protein-containing matrices as well as the plasma indole concentrations in healthy controls and patients with carcinoid tumors. Plasma, cerebrospinal fluid, and tissue homogenates were prepurified by automated on-line solid-phase extraction (SPE) in Hysphere Resin SH SPE cartridges containing strong hydrophobic polystyrene resin. Analytes were eluted from the SPE cartridge by column switching. Subsequent separation and detection were performed by reversed-phase HPLC combined with fluorometric detection in a total cycle time of 20 min. We obtained samples from 14 healthy controls and 17 patients with metastasized midgut carcinoid tumors for plasma indole analysis. In the patient group, urinary excretion of 5-HIAA and serotonin was compared with concentrations of plasma indoles. Within- and between-series CVs for indoles in platelet-rich plasma were 0.6-6.2% and 3.7-12%, respectively. Results for platelet-rich plasma serotonin compared favorably with those obtained by single-component analysis. Plasma 5-HIAA, but not 5-HTP was detectable in 8 of 17 patients with carcinoid tumors. In the patient group, platelet-rich plasma total tryptophan correlated negatively with platelet-rich plasma serotonin (P = 0.021; r = -0.56), urinary 5-HIAA (P = 0.003; r = -0.68), and urinary serotonin (P manual, single-component analyses.

Influence of Plasma Jet Temperature Profiles in Arc Discharge Methods of Carbon Nanotubes Synthesis.

Science.gov (United States)

Raniszewski, Grzegorz; Wiak, Slawomir; Pietrzak, Lukasz; Szymanski, Lukasz; Kolacinski, Zbigniew

2017-02-23

One of the most common methods of carbon nanotubes (CNTs) synthesis is application of an electric-arc plasma. However, the final product in the form of cathode deposit is composed of carbon nanotubes and a variety of carbon impurities. An assay of carbon nanotubes produced in arc discharge systems available on the market shows that commercial cathode deposits contain about 10% CNTs. Given that the quality of the final product depends on carbon-plasma jet parameters, it is possible to increase the yield of the synthesis by plasma jet control. Most of the carbon nanotubes are multiwall carbon nanotubes (MWCNTs). It was observed that the addition of catalysts significantly changes the plasma composition, effective ionization potential, the arc channel conductance, and in effect temperature of the arc and carbon elements flux. This paper focuses on the influence of metal components on plasma-jet forming containing carbon nanotubes cathode deposit. The plasma jet temperature control system is presented.

Influence of Plasma Jet Temperature Profiles in Arc Discharge Methods of Carbon Nanotubes Synthesis

Directory of Open Access Journals (Sweden)

Grzegorz Raniszewski

2017-02-01

Full Text Available One of the most common methods of carbon nanotubes (CNTs synthesis is application of an electric-arc plasma. However, the final product in the form of cathode deposit is composed of carbon nanotubes and a variety of carbon impurities. An assay of carbon nanotubes produced in arc discharge systems available on the market shows that commercial cathode deposits contain about 10% CNTs. Given that the quality of the final product depends on carbon–plasma jet parameters, it is possible to increase the yield of the synthesis by plasma jet control. Most of the carbon nanotubes are multiwall carbon nanotubes (MWCNTs. It was observed that the addition of catalysts significantly changes the plasma composition, effective ionization potential, the arc channel conductance, and in effect temperature of the arc and carbon elements flux. This paper focuses on the influence of metal components on plasma-jet forming containing carbon nanotubes cathode deposit. The plasma jet temperature control system is presented.

Interaction of Ambipolar Plasma Flow with Magnetic Islands in a Quasi-axisymmetric Stellarator

International Nuclear Information System (INIS)

Reiman, A.; Zarnstorff, M.; Mikkelsen, D.; Owen, L.; Mynick, H.; Hudson, S.; Monticello, D.

2004-01-01

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

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

International Nuclear Information System (INIS)

Reiman, A.; Zarnstorff, M.; Mikkelsen, D.; Mynick, H.; Hudson, S.; Monticello, D.; Owen, L.

2005-01-01

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

Investigation of RF-enhanced plasma potentials on Alcator C-Mod

Energy Technology Data Exchange (ETDEWEB)

Ochoukov, R., E-mail: ochoukov@psfc.mit.edu [PSFC MIT, NW17, 175 Albany Street, Cambridge, MA 02139 (United States); Whyte, D.G.; Brunner, D. [PSFC MIT, NW17, 175 Albany Street, Cambridge, MA 02139 (United States); Cziegler, I. [Center for Energy Research, UCSD, 9500 Gilman Drive, La Jolla, CA 92093 (United States); LaBombard, B.; Lipschultz, B. [PSFC MIT, NW17, 175 Albany Street, Cambridge, MA 02139 (United States); Myra, J. [Lodestar Research Corporation, 2400 Central Avenue P-5, Boulder, CO 80301 (United States); Terry, J.; Wukitch, S. [PSFC MIT, NW17, 175 Albany Street, Cambridge, MA 02139 (United States)

2013-07-15

Radio frequency (RF) sheath rectification is a leading mechanism suspected of causing anomalously high erosion of plasma facing materials in RF-heated plasmas on Alcator C-Mod. An extensive experimental survey of the plasma potential (Φ{sub P}) in RF-heated discharges on C-Mod reveals that significant Φ{sub P} enhancement (>100 V) is found on outboard limiter surfaces, both mapped and not mapped to active RF antennas. Surfaces that magnetically map to active RF antennas show Φ{sub P} enhancement that is, in part, consistent with the recently proposed slow wave rectification mechanism. Surfaces that do not map to active RF antennas also experience significant Φ{sub P} enhancement, which strongly correlates with the local fast wave intensity. In this case, fast wave rectification is a leading candidate mechanism responsible for the observed enhancement.

Development of negative heavy ion sources for plasma potential measurement

International Nuclear Information System (INIS)

Sasao, M.; Okabe, Y.; Fujisawa, A.; Iguchi, H.; Fujita, J.; Yamaoka, H.; Wada, M.

1991-10-01

A plasma sputter negative ion source was studied for its applicability to the potential measurement of a fusion plasma. Both the beam current density and the beam energy spread are key issues. Energy spectra of a self extracted Au - beam from the source were measured under the condition of a constant work function of the production surface. The full width of half maximum (FWHM) increases from 3 eV to 9 eV monotonically as the target voltage increases from 50 V to 300 V, independently from the target surface work function of 2.2 - 3 eV. (author)

Shear flow instability in a partially-ionized plasma sheath around a fast-moving vehicle

International Nuclear Information System (INIS)

Sotnikov, V. I.; Mudaliar, S.; Genoni, T. C.; Rose, D. V.; Oliver, B. V.; Mehlhorn, T. A.

2011-01-01

The stability of ion acoustic waves in a sheared-flow, partially-ionized compressible plasma sheath around a fast-moving vehicle in the upper atmosphere, is described and evaluated for different flow profiles. In a compressible plasma with shear flow, instability occurs for any velocity profile, not just for profiles with an inflection point. A second-order differential equation for the electrostatic potential of excited ion acoustic waves in the presence of electron and ion collisions with neutrals is derived and solved numerically using a shooting method with boundary conditions appropriate for a finite thickness sheath in contact with the vehicle. We consider three different velocity flow profiles and find that in all cases that neutral collisions can completely suppress the instability.

Profiling metals in Cordyceps sinensis by using inductively coupled plasma mass spectrometry.

Science.gov (United States)

Wei, Xin; Hu, Hankun; Zheng, Baogeng; Arslan, Zikri; Huang, Hung-Chung; Mao, Weidong; Liu, Yi-Ming

2017-01-28

Cordyceps sinensis ( C. sinensis ) is a natural product that has diverse nutritional and medicinal values. Since the availability of natural C. sinensis becomes limited its authentication and quality control is of high significance. Herein we report on profiling of metals in C. sinensis by using inductively coupled plasma mass spectrometry (ICP-MS). The analysis reveals that C. sinensis contains a wide array of essential elements, including P, Mg, Zn, Cu, Fe, etc. Toxic metals detected are Cd, Pb, and As. In all five samples analyzed Pb contents are below 2.0 ppm. Arsenic level in C. sinensis caterpillar is significantly higher than that in its mycelium and varies from 3.0 to 32 ppm likely due to soil contamination. It's for the first time demonstrated in this work that clustering analysis on the proposed metal profiles consisting of 24 elements is very useful to identify "abnormal" C. sinensis samples, thus adding another dimension to the effective means for authentication and quality assessment of this highly demanded previous natural product.

Floquet states of a kicked particle in a singular potential: Exponential and power-law profiles

Science.gov (United States)

Paul, Sanku; Santhanam, M. S.

2018-03-01

It is well known that, in the chaotic regime, all the Floquet states of kicked rotor system display an exponential profile resulting from dynamical localization. If the kicked rotor is placed in an additional stationary infinite potential well, its Floquet states display power-law profile. It has also been suggested in general that the Floquet states of periodically kicked systems with singularities in the potential would have power-law profile. In this work, we study the Floquet states of a kicked particle in finite potential barrier. By varying the height of finite potential barrier, the nature of transition in the Floquet state from exponential to power-law decay profile is studied. We map this system to a tight-binding model and show that the nature of decay profile depends on energy band spanned by the Floquet states (in unperturbed basis) relative to the potential height. This property can also be inferred from the statistics of Floquet eigenvalues and eigenvectors. This leads to an unusual scenario in which the level spacing distribution, as a window in to the spectral correlations, is not a unique characteristic for the entire system.

Normal chemotaxis in Dictyostelium discoideum cells with a depolarized plasma membrane potential

NARCIS (Netherlands)

Duijn, Bert van; Vogelzang, Sake A.; Ypey, Dirk L.; Molen, Loek G. van der; Haastert, Peter J.M. van

1990-01-01

We examined a possible role for the plasma membrane potential in signal transduction during cyclic AMP-induced chemotaxis in the cellular slime mold Dictyostelium discoideum. Chemotaxis, cyclic GMP and cyclic AMP responses in cells with a depolarized membrane potential were measured. Cells can be

Investigation of the electric field structure in ISX-B plasmas

Energy Technology Data Exchange (ETDEWEB)

Mathew, J.; Hallock, G.A.; Jennings, W.C.; Hickok, R.L.; Wootton, A.J.; Sigmar, D.J.

1986-04-01

Plasma potentials have been measured for the first time in neutral-beam-heated tokamak discharges. Radial potential profiles have been obtained for coinjection, counterinjection, and balanced injection discharges as well as for ohmically heated plasmas in the Impurity Study Experiment (ISX-B) tokamak. Within experimental uncertainties, the measured values of potential are consistent with calculations based on radial momentum balance using experimental values of rotation velocities, density, and ion temperature. The measurements were made using a heavy-ion beam probe, with typical plasma conditions of I/sub p/ approx. = 150 kA, B/sub T/ approx. = 12.3 kG, n-bar/sub e/ approx. = 4 x 10/sup 13/ cm/sup -3/, and P/sub b/ approx. = 0.9 MW. A negative potential well depth of about 1.0 kV was observed in ohmically heated plasmas and increased somewhat for balanced injection. Counterinjection resulted in a significantly larger well depth of approximately 3 to 4 kV, while coinjection showed an outward-pointing electric field in the plasma interior. The particle confinement times of both ions and impurities were observed to improve with counterinjection as compared with coinjection.

Investigation of the electric field structure in ISX-B plasmas

International Nuclear Information System (INIS)

Mathew, J.; Hallock, G.A.; Jennings, W.C.; Hickok, R.L.; Wootton, A.J.; Sigmar, D.J.

1986-04-01

Plasma potentials have been measured for the first time in neutral-beam-heated tokamak discharges. Radial potential profiles have been obtained for coinjection, counterinjection, and balanced injection discharges as well as for ohmically heated plasmas in the Impurity Study Experiment (ISX-B) tokamak. Within experimental uncertainties, the measured values of potential are consistent with calculations based on radial momentum balance using experimental values of rotation velocities, density, and ion temperature. The measurements were made using a heavy-ion beam probe, with typical plasma conditions of I/sub p/ approx. = 150 kA, B/sub T/ approx. = 12.3 kG, n-bar/sub e/ approx. = 4 x 10 13 cm -3 , and P/sub b/ approx. = 0.9 MW. A negative potential well depth of about 1.0 kV was observed in ohmically heated plasmas and increased somewhat for balanced injection. Counterinjection resulted in a significantly larger well depth of approximately 3 to 4 kV, while coinjection showed an outward-pointing electric field in the plasma interior. The particle confinement times of both ions and impurities were observed to improve with counterinjection as compared with coinjection

Metabolic profiling of plasma amino acids shows that histidine increases following the consumption of pork

Directory of Open Access Journals (Sweden)

Samman S

2014-06-01

Full Text Available Samir Samman,1 Ben Crossett,2 Miles Somers,1 Kirstine J Bell,1 Nicole T Lai,1,3 David R Sullivan,3 Peter Petocz4 1Discipline of Nutrition and Metabolism, 2Discipline of Proteomics and Biotechnology, School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia; 3Department of Clinical Biochemistry, Royal Prince Alfred Hospital, Sydney, NSW, Australia; 4Department of Statistics, Macquarie University, Sydney, NSW, Australia Abstract: Amino acid (AA status is determined by factors including nutrition, metabolic rate, and interactions between the metabolism of AA, carbohydrates, and lipids. Analysis of the plasma AA profile, together with markers of glucose and lipid metabolism, will shed light on metabolic regulation. The objectives of this study were to investigate the acute responses to the consumption of meals containing either pork (PM or chicken (CM, and to identify relationships between plasma AA and markers of glycemic and lipemic control. A secondary aim was to explore AA predictors of plasma zinc concentrations. Ten healthy adults participated in a postprandial study on two separate occasions. In a randomized cross-over design, participants consumed PM or CM. The concentrations of 21 AA, glucose, insulin, triglycerides, nonesterified fatty acids, and zinc were determined over 5 hours postprandially. The meal composition did not influence glucose, insulin, triglyceride, nonesterified fatty acid, or zinc concentrations. Plasma histidine was higher following the consumption of PM (P=0.014, with consistently higher changes observed after 60 minutes (P<0.001. Greater percentage increases were noted at limited time points for valine and leucine + isoleucine in those who consumed CM compared to PM. In linear regression, some AAs emerged as predictors of the metabolic responses, irrespective of the meal that was consumed. The present study demonstrates that a single meal of PM or CM produces a differential profile of AA in the

A CO2 laser polarimeter for measurement of plasma current profile in Alcator C-Mod

International Nuclear Information System (INIS)

Ma, C.H.; Hutchinson, D.P.; Richards, R.K.; Irby, J.; Luke, T.

1994-01-01

A multichannel infrared polarimeter system for measurement of the plasma current profile in Alcator C-Mod has been designed, constructed, and tested. The system utilizes a cw CO 2 , laser at a wavelength of 10.6 μm. An electro-optic polarization-modulation technique has been used to achieve the high sensitivity required for the measurement. The recent results of the measurements as well as the feasibility of its application on ITER are presented

Proteomic profiling of human plasma exosomes identifies PPARγ as an exosome-associated protein

International Nuclear Information System (INIS)

Looze, Christopher; Yui, David; Leung, Lester; Ingham, Matthew; Kaler, Maryann; Yao, Xianglan; Wu, Wells W.; Shen Rongfong; Daniels, Mathew P.; Levine, Stewart J.

2009-01-01

Exosomes are nanovesicles that are released from cells as a mechanism of cell-free intercellular communication. Only a limited number of proteins have been identified from the plasma exosome proteome. Here, we developed a multi-step fractionation scheme incorporating gel exclusion chromatography, rate zonal centrifugation through continuous sucrose gradients, and high-speed centrifugation to purify exosomes from human plasma. Exosome-associated proteins were separated by SDS-PAGE and 66 proteins were identified by LC-MS/MS, which included both cellular and extracellular proteins. Furthermore, we identified and characterized peroxisome proliferator-activated receptor-γ (PPARγ), a nuclear receptor that regulates adipocyte differentiation and proliferation, as well as immune and inflammatory cell functions, as a novel component of plasma-derived exosomes. Given the important role of exosomes as intercellular messengers, the discovery of PPARγ as a component of human plasma exosomes identifies a potential new pathway for the paracrine transfer of nuclear receptors.

Effects of Dietary Lycopene Supplementation on Plasma Lipid Profile, Lipid Peroxidation and Antioxidant Defense System in Feedlot Bamei Lamb