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We report the observation of photoluminescence across the band gap of semiconducting carbon nanotubes encased in organic micelles at room temperature, for a large set of growth conditions and environment. The key point for observing luminescence is to produce samples where nanotubes are isolated from each other and from the substrate. Moreover, we demonstrate that photoluminescence is a sensitive tool for probing the existence of structural or chemical defects. [Copyright &y& Elsevier]

We present a time-resolved experimental study of carrier dynamics in single wall carbon nanotubes (SWCNTs). This study is performed by means of pump–probe experiments in either a degenerate or a two-color configuration with a resonant excitation of semi-conductor SWCNTs. Both pump and probe are in resonance with the interband transitions of the semiconductor nanotubes (at 0.8 and 1.47 eV). We observe photobleaching with a typical recovery time of 1 ps. This non-linear response is governed by the carrier recombination at the band edge of semiconductor nanotubes. [Copyright &y& Elsevier]

Selective placement can be achieved with carbon nanotubes dispersed in N-methyl pyrrolidone (NMP) on aminopropyltriethoxysilane patterns. Investigations by AFM show a high deposition density of the nanotubes compared to water–surfactant solutions. [Copyright &y& Elsevier]

Abstract: A novel approach to the modeling of atomic populations in turbulent plasmas is applied to ionization–recombination balance calculations. Fluctuations of the fluid parameters are retained using a time-dependent statistical approach, suitable for cases where the turbulence characteristic times are of the same order as or smaller than the typical atomic relaxation times. We show that the populations are sensitive to the shape of the autocorrelation function of the fluctuations. An illustration is proposed through an ideal two-level system forced by non-Markovian temperature fluctuations. [Copyright &y& Elsevier]

Femtosecond pump–probe experiments have been carried out on an ensemble of single-wall carbon nanotubes deposited on a glass substrate. Measurements of transient changes of transmission and reflection provide an estimate of the real and imaginary parts of the second-order hyperpolarizability of carbon nanotubes. These values are compared with previous measurements and are discussed in the light of a simple model of the optical nonlinearities near the optical band-gap. [ABSTRACT FROM AUTHOR]

The transport of neutral particles in turbulent plasmas is addressed from the prospect of developing coarse-grained transport models which can be implemented in code suites like B2-EIRENE, currently used for designing the ITER divertor. The statistical properties of turbulent fluctuations are described by a multivariate Gamma distribution able to retain space and time correlations through a proper choice of covariance function. We show that in the scattering free case, relevant for molecules and impurity atoms, the average neutral particle density obeys a Boltzmann equation with an ionization rate renormalized by fluctuations. This result lends itself to a straightforward implementation in the EIRENE Monte Carlo solver for neutral particles. Special emphasis is put on the inclusion of time correlations, and in particular on the ballistic motion of coherent turbulent structures. The role of these time dependent effects is discussed for D2 molecules and beryllium atoms. The sensitivity of our results to the assumptions on the statistical properties of fluctuations is investigated. [ABSTRACT FROM AUTHOR]

Abstract: The effect of turbulence on the transport of neutral species (atom, molecules) in plasmas is investigated. A stochastic model relying on a multivariate gamma distribution is used to describe turbulent fluctuations. This model incorporates several important known features of Scrape-off-Layer turbulence, and has been implemented in the EIRENE Monte Carlo code. The effect of fluctuations on the neutral density, ionisation source and Balmer α radial profiles are investigated. Two important control parameters are identified, namely the ratio of the neutral mean free path to the size of turbulent structures, and the ratio of recycling time scales to the turbulent times. [Copyright &y& Elsevier]

The Action to Control Cardiovascular Disease in Diabetes (ACCORD) blood pressure trial is an unmasked, open-label, randomized trial with a sample size of 4,733 participants. This report describes the rationale, design, and methods of the blood pressure interventions in ACCORD. Participants eligible for the blood pressure trial are randomized to 1 of 2 groups with different treatment goals: systolic blood pressure <120 mm Hg for the more intensive goal and systolic blood pressure <140 mm Hg for the less intensive goal. The primary outcome measure for the trial is the first occurrence of a major cardiovascular disease (CVD) event, specifically nonfatal myocardial infarction or stroke, or cardiovascular death during a follow-up period ranging from 4–8 years. The ACCORD blood pressure trial should provide the first definitive clinical trial data on the possible benefit of treating to a more aggressive systolic blood pressure goal in reducing CVD events in patients with diabetes mellitus. [Copyright &y& Elsevier]