Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Ion temperature and plasma rotation velocity measurements using visible spectroscopy on TdeV : Proceedings of the 12th topical conference on high temperature plasma diagnostics (1999)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 387-390 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A visible spectroscopic imaging system has been developed on Tokamak de Varennes (TdeV) that provides profile measurements of the ion temperature and plasma rotation velocity. Multiple poloidal and tangential chords were coupled to the entrance slit of a spectrometer equipped with a back-illuminated charge coupled device camera at its exit slit. The camera records spatially and spectrally resolved emission profiles with real time digitization and up to 70 ms/frame as temporal resolution. Line-integrated radiation from different ionization stages in the visible range (B V, C III, He II, and N IV) were chosen as representative of the plasma in their regions of maximum emission. Three types of plasma discharges are compared: ohmic and electron cyclotron resonance heated L and H modes. Preliminary results show that with an L–H transition, there is a 20%–30% increase of the ion temperature at midradius, without a pedestal and an increase of the toroidal velocity shear at r/a∼0.8. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1149302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Spectroscopic measurements of tokamak plasma ion temperature using Doppler broadening of impurity lines: Correction for chordal line-of-sight observations (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 1968-1973 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Tokamak ion temperatures measured using the Doppler-broadened impurity spectral line technique are usually underestimated because the line intensity is integrated along chordal lines of sight and is assumed to be the intensity at the chordal distance from the center of the plasma (radial distance). An analytical correction of the ion temperature radial profile during a series of reproducible discharges on the Tokamak de Varennes reveals a 10%–20% underestimation at the plasma center. The lines used are Ne IX (1248.2 A(ring)) and O VII (1623.7 A(ring)). Reconstruction of spectral line intensities and shapes using measured electron temperature and density profiles, ion density radial profiles simulated by a plasma impurity transport code, and published atomic data can verify and predict this correction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.348769
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Local effects of upstream divertor components on divertor plasma parameters and impurity retention forces (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 2494-2507 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The toroidally-viewing spectroscopic imaging system on Tokamak de Varennes (TdeV) [F. Meo et al., Rev. Sci. Instrum. 68, (1997)] has given new insight into the physics of a closed divertor, where the particles interact with a vertically oriented inclined plate situated upstream from the target plate. The system has enabled two-dimensional (2D) measurements of the absolute emissivities of Hydrogen Balmer lines, as well as Carbon lines. Using the Balmer ratios, the poloidal profile of the electron density has been calculated using a Collisional-Radiative model [K. Sawada and T. Fujimoto, J. Appl. Phys. 78, 2913 (1994)]. Results show that the plasma parameters are locally affected by the divertor components particularly the inclined plate. This inclined plate constitutes an extra recycling surface which causes an increase in the atomic density and a decrease in the electron density in this region and affecting the plasma parameters at the target plate. Finally, the calculated poloidal plasma parameters are projected onto the field lines and are used in one-dimensional simplified (1D) particle and momentum balance equations. The simplified particle balance equation has shown that the extra neutrals from the inclined plate increase the parallel velocity locally. According to the simplified 1D fluid model, the analysis of the momentum balance equation has allowed the calculation of the poloidal profile of the ion temperature and hence the ion thermal force. The (bold del)Ti force on the impurity ions increases in the region of the inclined plate, which may seriously affect the impurity retention in the divertor. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.874089
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Various divertor biasing configurations and improved divertor performance with biasing on Tokamak de Varennes (TdeV)* (1994)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 1497-1502 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electrically insulated divertor plates are used on TdeV (Tokamak de Varennes) [18th EPS Conference on Controlled Fusion and Plasma Physics Berlin (European Physical Society, Petit-Lancy, 1991), Vol. 15C, Part I, pp. 1–141] to produce various biasing configurations, which can be decomposed into two basic modes. Plasma biasing, with a radial electric field Er in the scrape-off layer (SOL), is most promising for divertor applications. The Er field is produced with a particular divertor plate geometry, causing a nonambipolar radial current and a particle flow in the Er×BT direction, toward one of the divertors (the active divertor). The pressure and impurity retention in the active divertor are shown, in the Ohmic regime, to be strongly increased by biasing. He exhaust through this divertor is increased by a factor of almost 3 with modest biasing voltages and currents scalable to larger devices. Biasing also modifies the power repartition between the divertors, with the active divertor also receiving a larger fraction of the power.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.870699
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Local poloidal and toroidal plasma rotation velocities and ion temperature in a tokamak plasma obtained with a matrix inversion method considering asymmetries (2000)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 7 (2000), S. 3641-3653 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An inversion technique is presented for the local poloidal and toroidal rotation velocities and for the ion temperature from line integrated measurements performed on Tokamak de Varennes (TdeV) [R. Decoste and TdeV Team, Proceedings of the 15th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Seville, 1994 (International Atomic Energy Agency, Vienna, 1995) IAEA-CN-60/A4-11]. The velocity is obtained using two matrix inversions; the first for the emissivity and the second with the velocity weighted emissivity. The temperature is obtained with three matrix inversions: emissivity, temperature weighted emissivity and rotation velocity squared. The effect of the rotation velocity represents up to 16% in the ion temperature for TdeV plasmas. The local values obtained using the lengths matrix with the magnetic flux lines from the equilibrium code are compared with those obtained by a standard Abel inversion with circular flux lines. Differences up to 20% are observed between the emissivities deduced with circular and real flux lines, whereas the rotation velocity and the ion temperature are very similar. The technique was applied for the poloidal and toroidal geometry to determine the poloidal and toroidal velocities and the emission asymmetries. Top poloidal and toroidal emissivities present strong asymmetries due to the divertor plates and the X point whereas bottom poloidal and toroidal emissivities show an inner–outer symmetry, making the inversion more reliable in this region. A first approach to model the strong asymmetry was made assuming that the emissivity has both a radial and a poloidal dependence. The best result was obtained using a radial dependence and a peaked function of the poloidal angle for the poloidal asymmetric part of the emissivity. Both emissivity and velocity asymmetries are present in the upper part of the plasma implying that the X point behaves as a source. Examples of emissivities, rotation velocities and ion temperatures observed in TdeV plasmas in H and L (high and low confinement) modes with different bottom plasma triangularity are shown. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1287417
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Modification of the internal electric field by biasing of the divertor plates in the Tokamak de Varennes (TdeV) (1997)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 3644-3654 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The radial electric field inside the separatrix has been deduced from spectroscopic measurements of impurities on TdeV (Tokamak de Varennes), using the reduced radial momentum balance and two neoclassical models [R. D. Hazeltine, Phys. Fluids 17, 961 (1974) and Y. B. Kim, P. H. Diamond, and R. J. Groebner, Phys. Fluids B 3, 2050 (1991)]. The results from all three models are in fair agreement. Furthermore, the electric field has been deduced using the same models both with and without biasing the divertor plates relative to the machine wall, showing an inward propagation of the effect of the biasing created in the scrape-off layer (SOL). Undeniably, the electric field has been modified well inside the separatrix (0.6(approximately-less-than)r/a(approximately-less-than)0.9), revealing the possibility of modifying the internal electric field by external means. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.872260
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Impaired contractile response of mesenteric arteries in Crohn’s disease (2000)
    Oxford UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 14 (2000), S. 0 
    Details
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Crohn’s disease is associated with vascular injury and dysregulation of the intestinal immune system which together can provide disturbance of mesenteric circulation functional properties.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To evaluate the vascular reactivity of mesenteric arteries from patients with Crohn’s disease.〈section xml:id="abs1-3"〉〈title type="main"〉Methods:Phenylephrine-induced contractions were assessed from 10 patients with Crohn’s disease and 8 control organ donors. NG-nitro-L-arginine-methyl-ester (L-NAME) was used to test the presence of inducible NO synthase. Endothelium dependent and independent relaxation was assessed using acetylcholine, bradykinin, calcium ionophore A23187 and sodium nitroprusside.〈section xml:id="abs1-4"〉〈title type="main"〉Results:The contractile response to phenylephrine was significantly decreased in arteries without endothelium from patients with Crohn’s disease. Exposure to the NO synthase inhibitor L-NAME restored the contractile response to phenylephrine. Relaxation remained unaltered in both groups.〈section xml:id="abs1-5"〉〈title type="main"〉Conclusion:These data provide direct evidence for fading of contraction caused by phenylephrine in Crohn’s disease. The restored mesenteric artery tone by a specific NO synthase inhibitor suggests that an increased production for NO in vascular smooth muscle might be responsible of this altered vascular reactivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2036.2000.00838.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Measurements of ne(r) and Te(r) in TdeV boundary layer by injection of laser ablated Li and C (1992)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 5698-5702 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Li-atom and C-atom beams with energies of 5 and 15 eV, respectively, have been used to measure the electron density and temperature profiles in the scrape off layer and the plasma edge in TdeV. The beam penetrates into the plasma up to line densities of about nel=3×1017 m−2 and allows an instantaneous (≈250 μs) measurement of ne and Te up to 1.5×1019 m−3 and 100 eV, respectively. A camera with a Si-diode array is used to determine the spatial emissivity of the emitted light. Te(r) and ne(r) are obtained from the different attenuation and emission characteristics over the spatial range from the wall to ≈50 mm within the separatrix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143351
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effects of exercise on glycemic control and body mass in type 2 diabetes mellitus: a meta-analysis of controlled clinical trials (2002)
    Oxford, UK : Munksgaard International Publishers
    Scandinavian journal of medicine & science in sports 12 (2002), S. 0 
    Details
    ISSN: 1600-0838
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Sports Science
    Notes: Context: Exercise is widely perceived to be beneficial for glycemic control and weight loss in patients with type 2 diabetes. However, clinical trials on the effects of exercise in patients with type 2 diabetes have had small sample sizes and conflicting results. Objective: To systematically review and quantify the effect of exercise on glycosylated hemoglobin (HbA(1c)) and body mass in patients with type 2 diabetes. Data sources: Database searches of MEDLINE, EMBASE, Sport Discuss, Health Star, Dissertation Abstracts and the Cochrane Controlled Trials Register for the period up to and including December 2000. Additional data sources included bibliographies of textbooks and articles identified by the database searches. Study selection: We selected studies that evaluated the effects of exercise interventions (duration ≥ = 8 weeks) in adults with type 2 diabetes. Fourteen (11 randomized and three non-randomized) controlled trials were included. Studies that included drug cointerventions were excluded. Data extraction: Two reviewers independently extracted baseline and post-intervention means and SDs for the intervention and control groups. The characteristics of the exercise interventions and the methodological quality of the trials were also extracted. Data synthesis: Twelve aerobic training studies [mean (SD), 3.4 (0.9) times/week for 18 (15) weeks] and two resistance training studies [mean (SD), 10 (0.7) exercises, 2.5 (0.7) sets, 13 (0.7) repetitions, 2.5 (0.4) times/week for 15 (10) weeks] were included in the analyses. The weighted mean post-intervention HbA(1c) was lower in the exercise groups compared with the control groups (7.65% vs 8.31%; weighted mean difference, 0.66%; P 〈 0.001). The difference in post-intervention body mass between exercise groups and control groups was not significant (83.02 kg vs 82.48 kg; weighted mean difference, 0.54; P= 0.76). Conclusion: Exercise training reduces HbA(1c) by an amount that should decrease the risk of diabetic complications, but no significantly greater change in body mass was found when exercise groups were compared with control groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1600-0838.2002.120111_3.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Beam assisted molecular rearrangement observed by TDPAD for fluorine complexes in diamond
    Amsterdam : Elsevier
    Nuclear Inst. and Methods in Physics Research, B 64 (1992), S. 237-241 
    Details
    ISSN: 0168-583X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0168-583X(92)95472-4
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...