Explicit mapping of acoustic regimes for wind instruments

This paper proposes a methodology to map the various acoustic regimes of wind instruments. The maps can be generated in a multidimensional space consisting of design, control parameters, and initial conditions. The boundaries of the maps are obtained explicitly in terms of the parameters using a Support Vector Machine (SVM) classifier as well as a dedicated adaptive sampling scheme. The approach is demonstrated on a simplified clarinet model for which several maps are generated based on different criteria. Examples of computation of the probability of occurrence of a specific acoustic regime are also provided. In addition, the approach is demonstrated on a design optimization example for optimal intonation.     

Combined directed ortho-metalation, remote metalation, and Stille cross-coupling strategies. Concise stereoselective synthesis of polysubstituted 9H-fluoren-9-ones

The new sequential stereoselective synthesis of diversely substituted 9H-fluoren-9-ones by ortho-lithiation/Bu₃SnCl quench of unprotected benzoic acids followed by Stille cross-coupling reaction and remote metalation is reported.     

NHC-carbene cyclopentadienyl iron based catalyst for a general and efficient hydrosilylation of imines

A general and efficient hydrosilylation of imines catalysed by a well defined NHC-carbene cyclopentadienyl iron complex has been developed. Both aldimines and ketimines are converted to the corresponding amines under mild conditions, and under visible light activation.     

New "one-step" method for the simultaneous synthesis and anchoring of organic monolith inside COC microchip channels

A new method for monolith synthesis and anchoring inside cyclic olefin copolymer (COC) microchannels in a single step is proposed. It is shown that type I photoinitiators, typically used in a polymerization mixture to generate free radicals during monolith synthesis, can simultaneously act as type II photoinitiators and react with the plastic surface through hydrogen abstraction. This mechanism is used to "photograft" poly(ethylene glycol) methacrylate (PEGMA) on COC surfaces. Contact angle measurements were used to observe the changes in surface hydrophilicity when increasing initiator concentration and irradiation duration. The ability of type I photoinitiators to synthesize and anchor a monolith inside COC microchannels in a single step was proved through SEM observations. Different concentrations of photoinitiators were tried. Finally, electrochromatographic separations of polycyclic aromatic hydrocarbons were realized to illustrate the beneficial effect of anchoring on chromatographic performances. The versatility of the method was demonstrated with two widely used photoinitiators: benzoin methyl ether (BME) and azobisisobutyronitrile (AIBN).     

Using small angle scattering (SAS) to structurally characterise peptide and protein self-assembled materials

In the past 20 years protein and peptide self-assembly has attracted material scientists' interest due to the possibility to exploit such molecular mechanism to create novel biomaterials including hydrogels. One of the main challenges when dealing with "soft" biological materials is their structural and morphological characterisation. Small angle scattering (SAS) can be a highly complementary tool to microscopy for the characterisation of such materials as it allows the investigation of samples in their wet-state without the need for any sample preparation such as drying and/or freezing. In this tutorial review we introduce briefly the SAS technique to the non-expert and through selected examples from the literature show how SAS can be readily used thanks to existing analytical approaches developed by a number of authors to extract structural information on the self-assembly of peptide and proteins.     

Recent methods for the determination of volatile and non-volatile organic compounds in natural and purified drinking water

Four analytical protocols for the extraction and preconcentration of organic residues in natural or purified drinking water were investigated and compared: closed loop stripping analysis; simultaneous extraction-distillation; purge and trap analysis; continuous liquid-liquid extraction. Organic extracts were submitted to a variety of separation and identification techniques. Volatiles were determined by conventional capillary column gas chromatography with tandem mass spectrometry, using triple-stage quadrupole instruments. Non-volatile and thermally labile molecules were investigated by several different techniques (high-temperature gas chromatography, capillary column supercritical fluid chromatography, pyrolysis gas chromatography-mass spectrometry, thermospray liquid chromatography with tandem mass spectrometry and conventional fast-atom bombardment with tandem mass spectrometry). Several samples recently examined in the laboratory provide examples of this multitechnique approach for a more complete knowledge of the organic carbon distribution in water-dissolved organic matter, taking into account organic substances with widely different volatilities, polarities and thermal stabilities.     

Simultaneous remote monitoring of atmospheric methane and water vapor using an integrated path DIAL instrument based on a widely tunable optical parametric source

We report on the remote sensing capability of an integrated path differential absorption lidar (IPDIAL) instrument, for multi-species gas detection and monitoring in the 3.3–3.7 µm range. This instrument is based on an optical parametric source composed of a master oscillator-power amplifier scheme—whose core building block is a nested cavity optical parametric oscillator—emitting up to 10 µJ at 3.3 µm. Optical pumping is realized with an innovative single-frequency, 2-kHz repetition rate, nanosecond microchip laser, amplified up to 200 µJ per pulse in a single-crystal fiber amplifier. Simultaneous monitoring of mean atmospheric water vapor and methane concentrations was performed over several days by use of a topographic target, and water vapor concentration measurements show good agreement compared with an in situ hygrometer measurement. Performances of the IPDIAL instrument are assessed in terms of concentration measurement uncertainties and maximum remote achievable range.