1,495 research outputs found
Removal of adsorbing estrogenic micropollutants by nanofiltration membranes:Part B-Model development
Diode-pumped, mechanically-flexible polymer DFB laser encapsulated by glass membranes
A diode-pumped, mechanically-flexible organic distributed-feedback laser that is fully encapsulated with ultra-thin glass is reported. The organic laser is excited by 450nm laser diode and emits at 537 nm with an oscillation threshold of 290 W/cm2. The encapsulation format of the device results in a photostability that is improved by two orders of magnitude compared to a non-encapsulated reference device while maintaining mechanical flexibility thanks to an overall device thickness below 105 μm. The laser is also wavelength-tunable between 535 nm and 545 nm by bending the ultra-thin glass structure
Changes in seabed morphology, mud temperature and free gas venting at the H ̊akon Mosby mud volcano, offshore northern Norway, over the time period 2003-2006
The HAyenkon Mosby mud volcano is a 1.5-km-diameter geological structure located on the Southwest Barents Sea slope at a water depth of 1,270 m. High-definition seabed mapping of the mud volcano has been carried out in 2003 and 2006. A comparative analysis of the bathymetry and backscatter maps produced from the two surveys shows subtle morphological changes over the entire crater of the mud volcano, interpreted to be the consequence of mud eruption events. Mud temperature measurements point to a persistently warm mud at shallow depth in the crater. This is explained by upward fluid advection, rather than conductive cooling of mud flows. The small-scale spatial variability in the temperature distribution may be related to mud outflows or changes in the fluid flow regime. Furthermore, the locations of free gas venting observed in 2006 were found to differ from those of 2003. Our observations of overall similar topographic profiles across the mud volcano in 2003 and 2006 suggest that eruption events would have been modest. Nevertheless, the data bring evidence of significant change in activity even over short time intervals of only 3 years. This may be a characteristic shared by other submarine mud volcanoes, notably those considered to be in a quiescent stage
Separation between coherent and turbulent fluctuations. What can we learn from the Empirical Mode Decomposition?
The performances of a new data processing technique, namely the Empirical
Mode Decomposition, are evaluated on a fully developed turbulent velocity
signal perturbed by a numerical forcing which mimics a long-period flapping.
First, we introduce a "resemblance" criterion to discriminate between the
polluted and the unpolluted modes extracted from the perturbed velocity signal
by means of the Empirical Mode Decomposition algorithm. A rejection procedure,
playing, somehow, the role of a high-pass filter, is then designed in order to
infer the original velocity signal from the perturbed one. The quality of this
recovering procedure is extensively evaluated in the case of a "mono-component"
perturbation (sine wave) by varying both the amplitude and the frequency of the
perturbation. An excellent agreement between the recovered and the reference
velocity signals is found, even though some discrepancies are observed when the
perturbation frequency overlaps the frequency range corresponding to the
energy-containing eddies as emphasized by both the energy spectrum and the
structure functions. Finally, our recovering procedure is successfully
performed on a time-dependent perturbation (linear chirp) covering a broad
range of frequencies.Comment: 23 pages, 13 figures, submitted to Experiments in Fluid
RGB and white-emitting organic lasers on flexible glass
Two formats of multiwavelength red, green and blue (RGB) laser on mechanically-flexible glass are demonstrated. In both cases, three all-organic, vertically-emitting distributed feedback (DFB) lasers are assembled onto a common ultra-thin glass membrane substrate and fully encapsulated by a thin polymer overlayer and an additional 50µm-thick glass membrane in order to improve the performance. The first device format has the three DFB lasers sitting next to each other on the glass substrate. The DFB lasers are simultaneously excited by a single overlapping optical pump, emitting spatially separated red, green and blue laser output with individual thresholds of, respectively, 28 µJ/cm2, 11 µJ/cm2 and 32 µJ/cm2 (for 5 ns pump pulses). The second device format has the three DFB lasers, respectively the red, green and blue laser, vertically stacked onto the flexible glass. This device format emits a white laser output for an optical pump fluence above 42 µJ/cm2
Examens périodiques de santé effectués chez des personnes en situation de handicap en Normandie durant l’année 2012
InGaN micro-LEDs integrated onto an ultra-thin, colloidal quantum dot functionalized glass platform
We demonstrate an integrated color-converting device by transfer printing blue-emitting micro-sized InGaN LEDs onto an ultra-thin glass platform functionally enhanced with colloidal quantum dots. Color conversion and waveguiding properties of the structure are presented
Uncertainty in measuring laminar burning velocity from expanding methane-air flames at low pressures
International audienceThe experimental determination of laminar burning velocity remains essential to evaluate the combustion potential of any fuels but also to validate kinetic mechanisms. Recently, researchers are making great efforts to improve the accuracy of the different setups and techniques to determine this parameter. This work proposes an attempt to summarize the different factors contributing to the uncertainty of the expanding spherical flame method. In particular, the validity of two hypothesis (adiabatic flame propagation and thin flame front) is discussed in the case of stoichiometric methane-air flames in low-pressure environment (from 0.2 to 2 bar). Last, the effect of spark electrode diameters was also considered (0.2, 0.5 and 1 mm)
Weak radiative hyperon decays, Hara's theorem and the diquark
Weak radiative hyperon decays are discussed in the diquark-level approach. It
is pointed out that in the general diquark formalism one may reproduce the
experimentally suggested pattern of asymmetries, while maintaining Hara's
theorem in the SU(3) limit. At present, however, no detailed quark-based model
of parity-violating diquark-photon coupling exists that would have the
necessary properties.Comment: 10 pages, LaTe
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