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Notes: A sudden, threefold increase in emission from fundamental electrostatic electron Bernstein waves (EBW) which mode convert and tunnel to the electromagnetic X-mode has been observed during high energy and particle confinement (H-mode) transitions in the National Spherical Torus Experiment (NSTX) plasma [M. Ono, S. Kaye, M. Peng et al., in Proceedings of the 17th IAEA Fusion Energy Conference (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135]. The mode-converted EBW emission viewed normal to the magnetic field on the plasma midplane increases when the density profile steepens in the vicinity of the mode conversion layer, which is located in the plasma scrape off. The measured conversion efficiency during the H-mode is consistent with the calculated EBW to X-mode conversion efficiency derived using edge density data. Calculations indicate that there may also be a small residual contribution to the measured X-mode electromagnetic radiation from polarization-scrambled, O-mode emission, converted from EBWs. © 2002 American Institute of Physics.

Notes: The formation of internal transport barriers (ITBs) has been observed in the core region of Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] under a variety of conditions. The improvement in core confinement following pellet injection (pellet enhanced performance or PEP mode) has been well documented on Alcator C-Mod in the past. Recently three new ITB phenomena have been observed which require no externally applied particle or momentum input. Short lived ITBs form spontaneously following the high confinement to low confinement mode transition and are characterized by a large increase in the global neutron production (enhanced neutron or EN modes). Experiments with ion cyclotron range of frequencies power injection to the plasma off-axis on the high field side results in the central density rising abruptly and becoming peaked. The ITB formed at this time lasts for ten energy confinement times. The central toroidal rotation velocity decreases and changes sign as the density rises. Similar spontaneous ITBs have been observed in ohmically heated H-mode plasmas. All of these ITB events have strongly peaked density profiles with a minimum in the density scale length occurring near r/a=0.5 and have improved confinement parameters in the core region of the plasma. © 2001 American Institute of Physics.

Notes: Electron transport has been measured in the Current-Drive Experiment Upgrade (CDX-U) (T. Jones, Ph.D. thesis, Princeton University, 1995) using two separate perturbative techniques. Sawteeth at the q=1 radius (r/a∼0.15) induced outward-propagating heat pulses, providing time-of-flight information leading to a determination of χe as a function of radius. Gas modulation at the plasma edge introduced inward-propagating cold pulses, providing a complementary time-of-flight based χe profile measurement. This work represents the first localized measurement of χe in a spherical torus. Core (r/a〈1/3) χe values from the sawtooth study are 1–2 m2/s, and from the gas modulation study are 1–6 m2/s, increasing by an order of magnitude or more outside of the core region. Furthermore, the χe profile exhibits a sharp transition near r/a=1/3. Spectral and profile analyses of the soft x-rays, scanning interferometer, and edge probe data show no evidence of a significant magnetic island causing the high χe region. Comparisons are performed to several theoretical models, with measured χe(approximate)5–10× neoclassical estimates in the core. © 2002 American Institute of Physics.

Notes: Localized electron heating [full width at half maximum of Δ(r/a)(approximate)0.2] by mode converted ion Bernstein waves (IBW) has been observed in the Alcator C-Mod tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)]. These experiments were performed in D(3He) plasmas at high magnetic field (B0=7.9 T), high-plasma density (ne0≥1.5×1020 m−3), and for 0.05≤nHe-3/ne≤0.30. Electron heating profiles of the mode converted IBW were measured using a break in slope analysis of the electron temperature versus time in the presence of rf (radio frequency) modulation. The peak position of electron heating was found to be well-correlated with 3He concentration, in agreement with the predictions of cold plasma theory. Recently, a toroidal full-wave ion cyclotron range of frequencies (ICRF) code TORIC [M. Brambilla, Nucl. Fusion 38, 1805 (1998)] was modified to include the effects of IBW electron Landau damping at (k⊥ρi)2(very-much-greater-than)1, This model was used in combination with a 1D (one-dimensional) integral wave equation code METS [D. N. Smithe et al., Radio Frequency Power in Plasmas, AIP Conf. Proc. 403 (1997), p. 367] to analyze these experiments. Model predictions were found to be in qualitative and in some instances quantitative agreement with experimental measurements. A model for mode conversion current drive (MCCD) has also been developed which combines a toroidal full wave code with an adjoint evaluation of the ICRF current drive efficiency. Predictions for off-axis MCCD in C-Mod have been made using this model and will be described. © 2000 American Institute of Physics.

Notes: Electron cyclotron emission (ECE) has been employed as a standard electron temperature profile diagnostic on many tokamaks and stellarators, but most magnetically confined plasma devices cannot take advantage of standard ECE diagnostics to measure temperature. They are either "overdense," operating at high density relative to the magnetic field (e.g., ωpe(very-much-greater-than)Ωce in a spherical torus) or they have insufficient density and temperature to reach the blackbody condition (τ〉2). Electron Bernstein waves (EBWs) are electrostatic waves that can propagate in overdense plasmas and have a high optical thickness at the electron cyclotron resonance layers as a result of their large kperp. In this article we report on measurements of EBW emission on the CDX-U spherical torus, where B0∼2 kG, 〈ne〉∼1013 cm−3 and Te(approximate)10–200 eV. Results are presented for electromagnetic measurements of EBW emission, mode converted near the plasma edge. The EBW emission was absolutely calibrated and compared to the electron temperature profile measured by a multipoint Thomson scattering diagnostic. Depending on the plasma conditions, the mode-converted EBW radiation temperature was found to be ≤Te and the emission source was determined to be radially localized at the electron cyclotron resonance layer. A Langmuir triple probe and a 140 GHz interferometer were employed to measure changes in the edge density profile in the vicinity of the upper hybrid resonance where the mode conversion of the EBWs is expected to occur. Initial results suggest EBW emission and EBW heating are viable concepts for plasmas where ωpe(very-much-greater-than)Ωce. © 2001 American Institute of Physics.

Notes: A flowing liquid lithium first wall or divertor target could virtually eliminate the concerns with power density and erosion, tritium retention, and cooling associated with solid walls in fusion reactors. To investigate the interaction of a spherical torus plasma with liquid lithium limiters, large area divertor targets, and walls, discharges will be established in the Current Drive Experiment-Upgrade (CDX-U) where the plasma–wall interactions are dominated by liquid lithium surfaces. Among the unique CDX-U lithium diagnostics is a multilayer mirror (MLM) array, which will monitor the 13.5 nm LiIII line for core lithium concentrations. Additional spectroscopic diagnostics include a grazing incidence extreme ultraviolet (XUV) spectrometer (STRS) and a filterscope system to monitor Dα and various impurity lines local to the lithium limiter. Profile data will be obtained with a multichannel tangential bolometer and a multipoint Thomson scattering system configured to give enhanced edge resolution. Coupons on the inner wall of the CDX-U vacuum vessel will be used for surface analysis. A 10 000 frame per second fast visible camera and an IR camera will also be available. © 2001 American Institute of Physics.

Notes: Aim: The ‘choke vessels’, defined by Taylor 1], are reduced-caliber anastomosing vessels which are normally the barrier in the vasculature. They also have capacity to dilate and increase the blood flow. The aim of this study is to investigate the anatomical and dynamic function of choke vessels. Study design: The 3-territory bipedicled flaps were elevated on the back of the Wistar rats 2]. The flaps were directly sutured back in place in the revascularized group (10 animals), and the plastic sheets were underlaid in the non-revascularized group (10 animals). On the day 3, each flap was converted to the mono-pedicled flap and was scanned by the laser flow-graphy and injected for the angiography. Results: All flaps survived completely. The revascularized flaps showed evenly dilated choke vessels in the 2 choke zones of the flaps and the blood flow from the vascular pedicle covered more than 2 territories. The non-revascularized flaps showed more remarkable but uneven dilatation of choke vessels between 2 choke zones. The blood flow in non-revascularized flaps, however, reached only 1 territory, blocked by the first choke zone which dilated less than the other zone. Conclusions: By dilating, the choke vessels are activated and can have the adverse function of regulating the blood flow, namely, suppression and escalation of the blood flow.

Notes: Abstract Magnetic fields in the intercluster medium have been measured using a variety of techniques, including studies of synchrotron relic and halo radio sources within clusters, studies of inverse Compton X-ray emission from clusters, surveys of Faraday rotation measures of polarized radio sources both within and behind clusters, and studies of cluster cold fronts in X-ray images. These measurements imply that most cluster atmospheres are substantially magnetized, with typical field strengths of order 1 muGauss with high areal filling factors out to Mpc radii. There is likely to be considerable variation in field strengths and topologies both within and between clusters, especially when comparing dynamically relaxed clusters to those that have recently undergone a merger. In some locations, such as the cores of cooling flow clusters, the magnetic fields reach levels of 10-40 muG and may be dynamically important. In all clusters the magnetic fields have a significant effect on energy transport in the intracluster medium. We also review current theories on the origin of cluster magnetic fields.

Notes: Abstract –  Objective: To determine the effectiveness of providing free toothpaste containing either 1450 or 440 ppm F on caries experience in 5-year-old children living in areas with different levels of material deprivation. Design:  Five-year, examiner-blind, randomized, controlled, parallel-group, clinical trial. Children were randomly assigned to three groups. Setting:  Health Districts in the north-west of England with high levels of dental caries. Clinical examinations were performed in schools during the period October 1999 to April 2000 when the children were 5–6 years old. Participants:  Children from 3-month birth cohorts resident in nine, nonfluoridated health districts. Interventions:  Toothpaste containing either 440 or 1450 ppm F and dental health literature posted at 3-month intervals and toothbrush provided annually from the age of 1–5〈inlineGraphic alt="inline image" href="urn:x-wiley:03015661:CDOE150:CDOE_150_mu1" location="equation/CDOE_150_mu1.gif"/〉 years. Comparison group received no intervention. Main outcome measures:  Mean dmft and proportion of participants with dmft 〉 0, dmft ≥ 4, upper primary incisor caries and extraction of one or more primary teeth. Outcomes tabulated for quartiles of participants based on the distribution of the Townsend index of material deprivation. Results:  A total of 3467 children were included in the final data analysis. The Townsend index was found to be useful in identifying groups of children with increased caries risk. Overall, participants in the programme using the high-fluoride toothpaste had significantly (P 〈 0.002) less caries than the comparison group with similar absolute reductions in mean dmft for the most- and least-deprived groups. Relative to the comparison group the association between deprivation and dental caries was changed so that in the most-deprived quartile those using the low-fluoride toothpaste tended to have less dental caries than the comparison group whereas in the least deprived they tended to have more. This difference in the association (slope) was statistically significant (P 〈 0.05). Provision of both low- and high-fluoride toothpaste appeared to reduce the risk of extractions for participants in the most-deprived quartile (P 〈 0.05). Conclusion:  The relative benefits of the programmes supplying the two toothpastes considered in this study are different depending on the deprivation status of the participants. For the most-deprived groups postal provision of either a low- or high-fluoride toothpaste provides similar levels of benefit. In the less deprived groups only provision of the high-fluoride toothpaste provided a benefit. The absolute caries reduction seen for provision of the high-fluoride toothpaste was not related to the deprivation status and hence the programme did not reduce deprivation-related health inequalities. Targeting the programme using the methods employed in this study is unlikely to improve the effectiveness of the programme.

Notes: Background : Tracheal mucosal damage related to tracheal intubation has been widely described in pediatric and adult patients. High volume–low pressure cuffs (HVLPC) are being advertised as safe to avoid this particularly unpleasant complication. Compliances of these supposed pediatric and adult HVLPC are not mentioned by manufacturers and still remain unknown.Methods : The compliance of HVLPC was measured in vitro and defined as the straight portion of the pressure–volume curve. Cuff pressure was measured after incremental 0.1 ml filling volumes of air for sizes 3.0–8.0 of internal diameter of RüschTM and MallinckrodtTM tracheal tubes. Compliances were assessed in air and in a rigid tube. The filling volume to achieve a 25-mmHg intracuff pressure was also measured.Results : In air, each 0.1 ml step almost linearly increased cuff pressure by 1 mmHg (size 8.0) to 9 mmHg (size 3). In air, the volume needed to maintain a cuff pressure 〈 25 mmHg was small for sizes 3–5.5 (0.35–2 ml). The 25 mmHg inflated cuff volume and compliance were decreased within a rigid tube, especially for adult sizes. In a rigid tube simulating a trachea, the compliances of almost every RüschTM tracheal tube were statistically higher than those of the MallinckrodtTM.Conclusion : We conclude that the tested tracheal tube cuffs have low compliance and cannot be defined as high volume–low pressure.