Burst statistics in Alcator C-Mod SOL turbulence

Bursty fluctuations in the scrape-off layer (SOL) of Alcator C-Mod have been analyzed using gas puff imaging data. This reveals many of the same fluctuation properties as Langmuir probe measurements, including normal distributed fluctuations in the near SOL region while the far SOL plasma is dominated by large amplitude bursts due to radial motion of blob-like structures. Conditional averaging reveals burst wave forms with a fast rise and slow decay and exponentially distributed waiting times. Based on this, a stochastic model of burst dynamics is constructed. The model predicts that fluctuation amplitudes should follow a Gamma distribution. This is shown to be a good description of the gas puff imaging data, validating this aspect of the model.Comment: 8 pages, 6 figure

Radiation distributions in TCV

Total radiative powers measured by foil bolometer and AXUV camera systems are compared to SOLPS5 simulations in low and high density deuterium and helium diverted discharges on the TCV tokamak. For low density the match between simulation and measurements is satisfactory, but at high density strongly radiating regions outside the SOLPS5 simulation grid are seen in measurements and this may indicate the presence of enhanced convective particle transport in the low field side midplane region. The chord coverage of the foil bolometer system does not, however, allow detailed resolution in this region. The comparison of foil and AXUV data also demonstrates that ageing of the AXUV diodes under plasma irradiation combined with the unevenness of the diode spectral response, strongly limits their application for total radiative power measurements. (c) 2007 Elsevier B.V. All rights reserved

Microbial diversity in grape musts from Austrian and South African grape varieties and regions

Vitis vinifera is one of the most widely planted crops and holds important economic value in South Africa and Austria. Grapes obtained from this plant harbour a complex fungal community which plays a crucial role in the wine fermentation process and influences wine flavour and aroma. For many years the contributions of the natural yeasts has been eclipsed by the use of active dry yeast (ADY) inoculant, mainly of the species Saccharomyces cerevisiae. However, recent studies show a growing interest in deciphering the natural microbial diversity and in promoting its persistence during fermentation in order to enhance wine typicity. The current preliminary study aims to provide a first broad assessment of the fungal community fingerprint of different grape varietals from different wine producing areas in Austria and South Africa through Automated Ribosomal Intergenic Spacer Analysis (ARISA). The ARISA profiles separated the samples according to country of origin, and suggested some regional and varietal separation within each country. Future work will evaluate the contribution of these fungal communities to wine chemical composition and sensorial distinctness

Assessment of the dining environment on and near the campuses of fifteen post-secondary institutions

Objective: The present study evaluated the restaurant and dining venues on and near post-secondary campuses varying in institution size. Design: The Nutrition Environment Measures Survey for Restaurants (NEMS-R) was modified to evaluate restaurants as fast food, sit down and fast casual; and campus dining venues as dining halls, student unions and snack bar/cafe ́s. ANOVA with post hoc Tukey’s B and T tests were used to distinguish differences between dining venues and associated institutions by size. Setting: The study was conducted at fifteen US post-secondary institutions, 2009–2011. Subjects: Data presented are from a sample of 175 restaurants and sixty-eight on-campus dining venues. Results: There were minimal differences in dining halls by institution size, although medium-sized institutions as compared with small-sized institutions offered significantly more healthful side dish/salad bar items. Dining halls scored significantly higher than student unions or snack bar/cafe ́s on healthful entre ́es, side dish/salad bar and beverages offerings, but they also had the most barriers to healthful dietary habits (i.e. all-you-can-eat). No differences were found by restaurant type for NEMS-R scores for total restaurant dining environment or healthful entre ́es and barriers. Snack bars had more healthful side dishes (P 5 0?002) and fast-food restaurants had the highest level of facilitators (i.e. nutrition information; P 5 0?002). Conclusions: Based on this evaluation in fifteen institutions, the full campus dining environment provides limited support for healthy eating and obesity prevention. The quality of campus dining environments can be improved via healthful offerings, providing nutrition information and other supports to facilitate healthy eating and prevent unwanted weight gain

SOLPS5 modelling of ELMing H-mode on TCV

Although ohmic H-modes have long been produced on the TCV tokamak and the effects of ELMs at the divertor targets studied in some detail [1], no attempt has yet been made to model the scrape-off layer (SOL) in these plasmas. This contribution describes details of the first such efforts to do so. Simulations with the coupled fluid-Monte Carlo SOLPS5 code are constrained by careful upstream Thomson scattering and fast reciprocating Langmuir probe profiles and the results compared w ith measurements at the divertor targets. Recent experiments with high power ECRH at the third harmonic have produced large, possibly Type I ELMs on TCV for the first time, but in standard ohmic H-modes operating close to the L-H transition threshold power, only Type III ELMs are obtained. Typical single null lower H-mode discharges have I p = 400 kA, n/n GW ~ 0.3 and steady ELMing phases with f ELM ~ 100 Hz, where each ELM exhausts only a few 100 J of plasma stored energy. As such, these ELMs cannot be compared with larger events typical elsewhere regarding the magnitude of target power fluxes etc., but their behaviou r with respect to transport in the SOL and interaction with the targets is no different. In fact, their benign nature makes the fluid plasma simulation in some ways more appropriate since the ELMs are insu fficiently large to require a true kinetic simulation and are likely to be less perturbing in the sense of parallel heat flux limits and variations in sheath heat transmission coefficients. The modelling attempts described here broadly follow the approach in [2], seeking first the closest match to upstream experimental profiles during inter-ELM phases using a step-like ansatz for the perpendicular particle and heat diffusivities (D and χ i,e ) in the edge and SOL regions, but also introducing a poloidal variation of the transport coefficients both in the main chamber and dive rtor. This is extremely important in TCV, where the unconventional divertor geometry means that care must be taken in the presence of steep H-mode edge barriers to tailor differently the transport in this region compared with the core. Similar reasoning applies even more to the ELM itself, which is known to burst into the SOL in the outboard, unfavourable curvature region and is thus extremely poloidally localised. This has also been accounted for in the simulations which, as in the earlier SOLPS5 attempts to simulate Type ELMs in JET [3], m odel the ELM as an instantaneous local increase in the transport coefficients and simulate the subsequent SOL transport in a time dependent way. Good agreement is found between code and experime nt in the inter-ELM phase. Experimentally, these Type III ELMs are too rapid for comparison on an individual ELM basis. Instead, many similar events are coherently averaged and simulation comp ared with power and par ticle flux measurements at the divertor targets and line integrated observations of recycling in the divertor volume obtained using a new fast AXUV diode camera system filtered for Lyman-alpha emission