Résolution d'équations intégrales d'un type particulier

Summary A method is outlined here in order to find out continous solutions with definite parity, of linear homogeneous integral equations having a kernelK (x,y) which is a homogeneous function in some infinite domain of thex, y-plane.     

Determination of mixing time by colourimetric diagnosis—Application to a new mixing system

A method for determining mixing times in a transparent stirred vessel for highly viscous fluids has been developed. The method involves a chemical decolourization with two acid-base indicators and a colourimetric diagnosis of digital images, deduced from a video captured during the mixing process. The advantages of the method developed are:(1) there is no disturbance of the fluid flow, and (2) measuring and determination of the degree of homogeneity is relatively effortless and cheap since it requires only a standard colour camera and commercial software for digital image analysis. This paper describes protocols for carrying this method out. In addition, examples of experimental results obtained for a standard impeller (of the helical ribbon agitator type) and a new piece of mixing equipment are given and discussed.     

2D imaging of laser wing effects and of soot sublimation in laser-induced incandescence measurements

The distribution of Laser-Induced Incandescence (LII) signal in sooting flames along the laser beam is imaged using two directions of observation: one counter to the propagation direction of the incident laser (backward LII) and one at right angles. It is shown that the effective probe volume, in which the LII signal is observed, is highly dependent on the laser irradiance profile. At high fluence, the LII from the central part of the beam decreases because of soot sublimation. This decrease can be compensated by an increase in the LII from the wings of the laser beam. This interaction is particularly important in the extraction of quantitative information in the backward LII case, which is the configuration best suited to the practical application of LII for in-situ particle concentration measurements in the exhaust of aero-engines.     

Protective Effect of Dermal Brimonidine Applications Against UV Radiation‐induced Skin Tumors,Epidermal Hyperplasia and Cell Proliferation in the Skin of Hairless Mice

Brimonidine at 0.18%, 1% and 2% concentrations applied topically in hairless mice significantly decreased tumor burden and incidences of erythema, flaking, wrinkling and skin thickening induced by UVR. The unbiased median week to tumor ≥1 mm was increased by the 1% and 2% concentrations. The tumor yield was reduced by all concentrations at week 40 for all tumor sizes but the ≥4 mm tumors with the 0.18% concentration. At week 52, the tumor yield was reduced for all tumor sizes and all brimonidine concentrations. The tumor incidence was reduced by all concentrations at week 40 for all tumor sizes, but the ≥4 mm tumor with the 0.18% concentration and at week 52 for all tumor sizes with the 1% and 2% concentrations and with the 0.18% concentration only for the ≥4 mm tumors. Reductions in ≥4 mm tumor incidences compared to the vehicle control group were 54%, 91% and 86% by week 52 for the 0.18%, 1% and 2% concentrations, respectively. Brimonidine at 2% applied 1 h before or just after UVB irradiation on hairless mice decreased epidermal hyperplasia by 23% and 32% and epithelial cell proliferation by 59% and 64%, respectively, similar to an epidermal growth factor receptor (EGFR) inhibitor.     

Spectroscopy and predissociation of the 3A2 electronic state of ozone 16O3 and 18O3 by high resolution Fourier transform spectrometry

A high resolution Fourier transform spectrometry analysis of the rotational structure of the 2(0)1 absorption bands of the 3A2<--X1A1 Wulf transition for the isotopomers 16O3 and 18O3 of the ozone molecule is presented. These bands are very intense compared to the 0(0)0 bands but the predissociation is so strong that the main sub-bands appear as continuous contours. Isolated lines and band contour methods are used together to analyse these two rovibrational bands. The lines corresponding to the F2 component are generally the most intense and isolated. Our data sets for the (0 1 0) level of the 3A2 state are limited to about 102 weakly or unperturbed rotational lines for the 2(0)1 of 16O3 in the range 9620-10,140 cm(-1) and 123 weakly or unperturbed rotational lines for the same band of 18O3. Using for each of them the well-defined ground state parameters, we obtained a standard deviation of about 0.035 cm(-1) in the fit to the lines for 16O3 and 0.027 cm(-1) in the case of 18O3. The rotational constants A, B and C, the three rotational distortion terms deltaK, deltaJK and deltaJ, the spin-rotation constants a0, a and b have been successfully calculated for 16O3 and 18O3 while the spin-spin constants were fixed to their respective values obtained for the origin bands. As is the case for the 0(0)0 band, we have a partial agreement with the isotopic laws for the rotational constants. The geometrical parameters of the (0 1 0) level of 3A2 state for the two isotopomers are close, r = 1.357 A, theta = 100.7 degrees for 18O3 and r = 1.352 A and theta = 100.0 degrees for 16O3. The origin of the 2(0)1 band of 18O3 is red shifted by 7.06(4) cm(-1) with respect to 16O3 2(0)1 band and the two bending mode quanta are, respectively, 528.99(9) and 501.34(7) cm(-1). A preliminary qualitative analysis of the predissociation is given in the particular case of the F2 spin component of 16O3 for 0(0)0 and 2(0)1 bands by the measurement of shifts of positions of some rovibrational levels and the evolution of predissociation broadenings in (Q)Q2 branches. We justify the existence of perturbations in the rovibrational levels of 3A2 state through different interaction types: with the dissociation continuum of the same electronic state or with high vibrational repulsive or weakly bound levels of the ground state.     

Measurement of separate cosmic-ray electron and positron spectra with the fermi large area telescope

We measured separate cosmic-ray electron and positron spectra with the Fermi Large Area Telescope. Because the instrument does not have an onboard magnet, we distinguish the two species by exploiting Earth's shadow, which is offset in opposite directions for opposite charges due to Earth's magnetic field. We estimate and subtract the cosmic-ray proton background using two different methods that produce consistent results. We report the electron-only spectrum, the positron-only spectrum, and the positron fraction between 20 and 200?GeV. We confirm that the fraction rises with energy in the 20-100?GeV range. The three new spectral points between 100 and 200?GeV are consistent with a fraction that is continuing to rise with energy.     

Synthesis and adsorption on gold surfaces of a functionalized thiol: elaboration and test of a new nitroaromatic gas sensor

A new type of sensor was built by synthesizing a long-chain thiol functionalized with an aromatic head group and grafting it onto a gold surface. The synthesis route is here described, together with the IR, MS, and RMN analysis of the new product. Adsorption of the latter onto gold was assessed by a combination of RAIRS and XPS data. Those reveal that a monolayer of thiol is adsorbed and oriented with the benzene groups toward the external part of the layer. Detection tests were performed in various atmospheres by QCM. The response shows good sensitivity to 2,4-dinitrotrifluoromethoxybenzene as a model of nitroaromatic compound.