Millimeter-Wave Beam Scattering by Field-Aligned Blobs in Simple Magnetized Toroidal Plasmas.

The first direct experimental measurements of the scattering of a millimeter-wave beam by plasma blobs in a simple magnetized torus are reported. The wavelength of the beam is comparable to the characteristic size of the blob. In situ Langmuir probe measurements show that fluctuations of the electron density induce correlated fluctuations of the transmitted power. A first-principles full-wave model, using conditionally sampled 2D electron density profiles, predicts fluctuations of the millimeter-wave power that are in agreement with experiments.

Single versus multiple visits for endodontic treatment of permanent teeth.

BACKGROUND: Root canal treatment (RoCT), or endodontic treatment, is a common procedure in dentistry. The main indications for RoCT are irreversible pulpitis and necrosis of the dental pulp caused by carious processes, tooth cracks or chips, or dental trauma. Successful RoCT is characterised by an absence of symptoms and clinical signs in teeth without radiographic evidence of periodontal involvement. The success of RoCT depends on a series of variables related to the preoperative condition of the tooth, as well as the endodontic procedures. OBJECTIVES: To compare the effectiveness of single- and multiple-visit RoCT, measured as tooth extraction due to endodontic problems and radiological success.To assess the difference in short- and long-term complications between single- and multiple-visit RoCT. SEARCH STRATEGY: The following databases were searched for relevant trials: Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE, and EMBASE. Handsearching was performed for the major oral medicine journals. References of included studies and reviews were checked. Endodontics experts were contacted through e-mail. No language limitations were imposed. Date of last search was 6th March 2007. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials of patients needing RoCT were included. Surgical endodontic treatment was excluded. The outcomes considered were the number of teeth extracted for endodontic problems; radiological success after at least 1 year, that is, absence of any periapical radiolucency; postoperative pain; painkiller use; swelling; or sinus track formation. DATA COLLECTION AND ANALYSIS: Data were collected using a specific extraction form. The validity of included studies was assessed on the basis of allocation concealment, blindness of the study, and loss of participants. Data were analysed by calculating risk ratios. When valid and relevant data were collected, a meta-analysis of the data was undertaken. MAIN RESULTS: Twelve randomised controlled trials were included in the review. Four studies had a low risk of bias, four a moderate risk, and another four had a high risk of bias. The frequency of radiological success and immediate postoperative pain were not significantly different between single- and multiple-visit RoCT. Patients undergoing single-visit RoCT reported a higher frequency of painkiller use and swelling, but the results for swelling were not significantly different between the two groups. We found no study that included tooth loss and sinus track formation among its primary outcomes. AUTHORS' CONCLUSIONS: No difference exists in the effectiveness of RoCT, in terms of radiological success, between single- and multiple-visit RoCT. Most short- and long-term complications are also similar in terms of frequency, although patients undergoing a single visit may experience a slightly higher frequency of swelling and are significatively more likely to take painkillers.

Advances in the FTU collective Thomson scattering system.

The new collective Thomson scattering diagnostic installed on the Frascati Tokamak Upgrade device started its first operations in 2014. The ongoing experiments investigate the presence of signals synchronous with rotating tearing mode islands, possibly due to parametric decay processes, and phenomena affecting electron cyclotron beam absorption or scattering measurements. The radiometric system, diagnostic layout, and data acquisition system were improved accordingly. The present status and near-term developments of the diagnostic are presented.

Measure of electron cyclotron emission at multiple angles in high T(e) plasmas of JET.

The oblique electron cyclotron emission (ECE) diagnostic installed at JET allows simultaneous analysis of the ECE spectra along three lines of sight (with toroidal angles of 0°, ∼ 10°, and ∼ 20°) and two linear polarizations for each oblique line of sight. The diagnostic is capable of measuring EC emission over the band of 75­800 GHz with 5 ms time resolution and 7.5 GHz spectral resolution, and it is designed to investigate the features of ECE spectra related to electron distribution in the thermal velocity range. Instrumental accuracy was assessed using sources at different temperatures (77­900 K) and with plasma emission. ECE from high temperature plasmas and in the presence of fast ions has been compared to simulations performed with the modeling code SPECE, setting an upper limit to possible discrepancies from thermal emission.