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Single-walled carbon nanotubes are considered a fascinating nanomaterial for photonic applications and are especially promising for efficient light emitters in the telecommunication wavelength range. Furthermore, their hybrid integration with silicon photonic structures makes them an ideal platform to explore their intrinsic properties. Here we report on the strong photoluminescence enhancement from carbon nanotubes integrated in silicon ring resonator circuits under two pumping configurations: surface-illuminated pumping at 735 nm and collinear pumping at 1.26 . Extremely efficient rejection of the non-resonant photoluminescence was obtained. In the collinear approach, an emission efficiency enhancement by a factor of 26 has been demonstrated in comparison with the classical pumping scheme. This demonstration paves the way for the development of integrated light sources in silicon based on carbon nanotubes. [ABSTRACT FROM AUTHOR]

Microbial communities have a key role for the performance of engineered ecosystems such as waste gas biofilters. Maintaining constant performance despite fluctuating environmental conditions is of prime interest, but it is highly challenging because the mechanisms that drive the response of microbial communities to disturbances still have to be disentangled. Here we demonstrate that the bioprocess performance and stability can be improved and reinforced in the face of disturbances, through a rationally predefined strategy of microbial resource management (MRM). This strategy was experimentally validated in replicated pilot-scale nitrifying gas-biofilters, for the two steps of nitrification. The associated biological mechanisms were unraveled through analysis of functions, abundances and community compositions for the major actors of nitrification in these biofilters, that is, ammonia-oxidizing bacteria (AOB) andNitrobacter-like nitrite-oxidizers (NOB). Our MRM strategy, based on the application of successive, transient perturbations of increasing intensity, enabled to steer the nitrifier community in a favorable way through the selection of more resistant AOB and NOB sharing functional gene sequences close to those of, respectively, Nitrosomonas eutropha andNitrobacter hamburgensis that are well adapted to high N load. The induced community shifts resulted in significant enhancement of nitrification resilience capacity following the intense perturbation. [ABSTRACT FROM AUTHOR]

Experimental results about efficient band-edge light coupling into two-dimensional planar photonic crystals by the use of a gradual interface are reported. It is shown that a chirp of both the lattice period and the hole diameter on short lengths below 3 mallows maintaining high optical transmission spectra close to the band-gap frequency where strongly dispersive phenomena can be exploited. If compared with nonoptimized structures, increased optical levels by 15 to 20 dBare obtained using gradual tapering stages. [ABSTRACT FROM AUTHOR]

This paper presents an experimental proof-of-concept of an innovative design of electrostatic vibration energy harvester based on a double bistable curved beam whose mechanical behaviour is significantly modified by additional linear springs. The basic analytical model for a curved beam with dynamical and quasi static behaviour is introduced and validated by finite element modelling. It is shown that the static force offset due to the gravity field can provide an important increase in the sensitivity to external acceleration. The device is fabricated using silicon on glass technology without the need of a wafer bonding technique. Energy harvesting experiments are performed with various orientations of the device relative to the gravity field direction. The electrical power output is derived from the output voltage measured across a storage capacitor. It is shown that the maximum power output of the energy harvester reaches 10 µW under 50 Hz, 10 m s−2 sine excitation, and is sensible at accelerations with amplitudes less than 1 g (down to 3 m s−2) and operating at a very low frequency range (5–100 Hz) with an overall device size of 1 cm  ×  1.5 cm  ×  200 µm. [ABSTRACT FROM AUTHOR]