Nonintrusive electron number density measurements in the plume of a 1 kW arcjet using a modern microwave interferometer

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77090/1/AIAA-1994-3297-662.pd

Towards a nanospecific approach for risk assessment.

In the current paper, a new strategy for risk assessment of nanomaterials is described, which builds upon previous project outcomes and is developed within the FP7 NANoREG project. NANoREG has the aim to develop, for the long term, new testing strategies adapted to a high number of nanomaterials where many factors can affect their environmental and health impact. In the proposed risk assessment strategy, approaches for (Quantitative) Structure Activity Relationships ((Q)SARs), grouping and read-across are integrated and expanded to guide the user how to prioritise those nanomaterial applications that may lead to high risks for human health. Furthermore, those aspects of exposure, kinetics and hazard assessment that are most likely to be influenced by the nanospecific properties of the material under assessment are identified. These aspects are summarised in six elements, which play a key role in the strategy: exposure potential, dissolution, nanomaterial transformation, accumulation, genotoxicity and immunotoxicity. With the current approach it is possible to identify those situations where the use of nanospecific grouping, read-across and (Q)SAR tools is likely to become feasible in the future, and to point towards the generation of the type of data that is needed for scientific justification, which may lead to regulatory acceptance of nanospecific applications of these tools.The research leading to these results has been partially funded by the European Union Seventh Framework Programme (FP7/ 2007e2013) under the project NANoREG (A common European approach to the regulatory testing of nanomaterials), grant agreement 310584.info:eu-repo/semantics/publishedVersio

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

Automatic Parallel Program Generation and Optimization from Data Decompositions

this paper a general framework is described for the automatic generation of parallel programs based on a separately specified decomposition of the data. To this purpose, programs and data decompositions are expressed in a calculus, called Vcal. It is shown that by rewriting calculus expressions, Single Program Multiple Data (SPMD) code can be generated for shared-memory as well as distributed-memory parallel processors. Optimizations are derived for certain classes of access functions to data structures, subject to block, scatter, and block/scatter decompositions. The presented calculus and transformations are language independent. 1

Bioavailability of sodium nitrite from an aqueous solution in healthy adults.

Nitrate intake in humans is high through intake of vegetables such as beets, lettuce, and spinach. Nitrate itself is a compound of low toxicity but its metabolite, nitrite, formed by bacteria in the oral cavity and gastrointestinal tract, has been suspected of potential carcinogenic effects. Nitrite can induce systemic toxicity only after having been absorbed from the gastrointestinal tract. The aim of this study was to determine the absolute bioavailability of nitrite following oral administration in humans. In an open, three-way cross-over study, nine subjects received two single oral doses of sodium nitrite (0.12 and 0.06 mmol NaNO(2)/mmol Hb) and one intravenous sodium nitrite dose (0.12 mmol NaNO(2)/mmol Hb). Plasma samples were analysed to assess the nitrite levels, and pharmacokinetic parameters were calculated. Nitrate and methaemoglobin levels in plasma were also measured as oxidation of nitrite results in the formation of these two compounds. Absolute bioavailability of nitrite was 98% after oral administration of 0.12 mmol NaNO(2)/mmol Hb, and 95% after oral administration of 0.06 mmol NaNO(2)/mmol Hb. Minor adverse effects were observed after the 0.12 mmol NaNO(2)/mmol Hb oral dose. In conclusion, nitrite in solution is highly absorbed from the gastrointestinal tract and the first pass effect in the liver is low