Application of headspace analysis to the study of aroma compounds-lipids interactions

Taking into account interactions between aroma compounds and food components is necessary to better manage the flavoring of food products. These interactions occur at a molecular level and reflect changes, at a macroscopic level, in thermodynamic equilibria, such as solubility or volatility. The rate of transfer of an aroma compound from the liquid to the vapor phase can be affected as well. The behavior of aroma compounds in water and lipid solutions was studied in two complementary ways, a thermodynamic and a kinetic approach (head-space analysis). The transfer rate of volatiles at the liquid-water interface does not only depend on the hydrophobicity of the aroma compounds. Vapor-liquid partition and activity coefficients show the presence of solute-solvent interactions. The Gibbs free energy values indicate their physicochemical nature.     

High-Speed Visible Light Communications Using Multiple-Resonant Equalization

White light-emitting diodes (LEDs) are becoming widespread in commercial lighting applications, and there are predictions that they will be in common use in domestic applications in the future. There is also growing interest in using these devices for both illumination and communications. One of the major challenges in visible light communications is the low modulation bandwidth (BW) available from devices, which is typically several megahertz. In this letter, we describe a link that uses 16 LEDs which are modulated using a resonant driving technique, creating an overall BW of 25 MHz. This is used to implement a 40-Mb/s nonreturn-to-zero on-off keying link which operates at low error rates, and also provides illumination at levels sufficient for a standard office environment.     

新型柱锤强夯法处理地基的检测分析

通过对几个工程检测实例分析及验算,阐述了在新型柱锤强夯(置换)法处理地基检测时,应从点、面上区别对待,分别进行统计,以体现处理后岩土层实际的物理、力学性能。     

HERSCHEL—PACS Bolometer Arrays for Submillimeter Ground-Based Telescopes

The Herschel Space Observatory will carry onboard a new kind of bolometric architecture for the PACS (Photodetector Array Camera and Spectrometer) submillimeter photometer. These new generation CCD-like multiplexed bolometer arrays are buttable and enable the conception of large fully sampled focal planes either for space or for ground-based telescopes. We present here some development for ground-based applications in the context of the ARTEMIS (ARchitecture de bolomètres pour des TElescopes sub-MIllimétriques au Sol) project. We have developed an electro-thermal numerical model that simulates the performances of these semiconducting bolometers under specific ground-based conditions (different wavelengths and background powers for example). This model permits to determine the optimal parameters for each condition and shows that the bolometers can be background limited in each atmospheric transmission window between 200 and 450 microns. We also describe the optical system that provides a high optical efficiency in each submillimeter atmospheric window. Astronomical observations made with a prototype on the APEX telescope are presented.     

A software tool for research in linguistics and lexicography: Application to Somali

General-purpose database management systems, whose structure is built in, are not an appropriate solution to situations where problems of translation or areas of research cannot be bounded in advance, for example, when lexicography and linguistic research are closely related. Consequently, an original system has been developed, and is being applied to linguistic and lexicographical data on the Somali language.Jacqueline Lecarme has a master's degree in Lettres Classiques (University of Grenoble, 1969) and a Ph.D. in linguistics (University of Montreal, 1978). Carole Maury has a master's degree and a doctorate in computer science (University of Nice, 1986).     

Photorefractive material response to short pulse illuminations

Photoconduction and hologram recording in a Bi12SiO20single crystal are studied from both theoretical and experimental points of view in the case of short pulse excitations. An approach taking into account two kinds of acceptor centers explains the charge transport processes in the case of both pulsed and continuous illuminations. A nanosecond temporal resolution allows us to access a time domain that is not normally considered, and on this time scale, the electron migration velocity is governed by the intrinsic mobility, which we have estimated to he greater than 3.2 cm²/V . s. Using this value, our theoretical developments explain the fast beam coupling phenomenon that we have experimentally observed.     

Slag corrosion of dolomite-carbon refractories

Seven industrial doloma refractory samples, coming from three European suppliers, and with different carbon, or graphite, or binder content, are subjected to the action of a slag required for the desulfurization of the steel in the secondary metallurgy at 1600°C. Three tests have been carried out within two induction furnaces. The corrosion depth, at the slag-steel interface, has been measured; the graphite-containing samples display a better resistance than the graphite-free pitch or resin-bonded refractories. Among the graphite-containing samples correlations have been found with the carbon content and with the resistance to oxidation by CO–CO₂ at 1100–1200°C. The slag-refractory interface has been investigated by X-ray diffraction, optical microscopy and electron microprobe analysis; the observed phases are CaO, MgO, Ca₂SiO₄, Ca₃SiO₅ and Ca₁₂Al₁₄O₃₃ (outside graphite and iron). The corrosion mechanism is linked to the reaction of slag with lime, followed by infiltration of the refractory and dispersion of periclase grains in the slag.     

Faraday rotation of terbium-yttrium ferrite garnet

The authors report Faraday rotation (FR) measurements performed on single crystals of terbium-yttrium iron garnets at 1.15-μm wavelength for three terbium contents (1.98, 1.02, and 0.35) in the temperature range 6-300 K, under magnetic field up to 20 kOe applied along the [111] and [100] directions. The spontaneous FR (associated with the spontaneous magnetization) is isotropic while the FR susceptibilities are anisotropic at low temperature; this anisotropy originates mainly from spin reorientation transitions. To analyze the terbium contribution to FR, the Fe contribution to the YIG data is evaluated. The terbium electric dipole transition coefficient is found to consist in a linear temperature dependence in the temperature range 100-300 K as previously observed in pure TbIG