Etude cinétique de l'oxydation de composés aromatiques (application à la formation de polluants dans les moteurs automobiles)

ORLEANS-BU Sciences (452342104) / SudocSudocFranceF

L'insertion professionnelle des jeunes transplantés rénaux

When young patients suffer from a chronic disease their mothers tend to be hyperprotective, doctors tend to prescribe unnecessary restrictions to their activities and fathers to think that all this is mothers' and doctors' concern. This keeps young patients away from the normal social life of their age. After analysing interviews of young patients of kidney transplants, we suggest, as a hypothesis, that this situation is an important negative factor resulting in bad adaptation to working conditions and excessive dependence on social funding.Nous constatons, dans un groupe de jeunes transplantés rénaux, des attitudes très contrastées relativement au travail. A partir d'entretiens, dans un groupe de 33 patients, nous proposons l'hypothèse que la bonne ou mauvaise adaptation au travail est fortement influencée par la manière dont s'est établie la relation entre les parents et l'enfant autour de la maladie. Le schéma défavorable est celui où l’angoisse hyper-protectrice de la mère ne rencontre pas de frein, c'est-à-dire si le médecin va dans le même sens en prescrivant, par prudence, des restrictions inutiles aux activités de l'enfant, si le père est complice de cette attitude ou s'il se désintéresse d'un enfant qui, du fait de sa maladie, appartient davantage à l'univers maternel, enfin si l'enfant ne trouve pas en lui-même la force de s’opposer. Il perd alors la possibilité de s'insérer dans les activités sociales normales dans l'enfance, dans des domaines comme la scolarité, les sports, les jeux avec des camarades. Ceux qui ont réussi mettent l'accent sur les activités sociales et sportives qui étaient précisément dans l'enfance des transgressions. Ils soulignent aussi la fermeté du père. La dépendance aux aides sociales paraît prendre le relai de la dépendance à la mère.Bagros Philippe, Pengloan Josette. L'insertion professionnelle des jeunes transplantés rénaux. In: Cahiers de sociologie économique et culturelle, n°22, 1994. pp. 43-48

Etude du débit sanguin d'un abord vasculaire par la mesure de la dialysance ionique

TOURS-BU Médecine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

OXIDATION OF 1-METHYLNAPHTHALENE AT 1–13 ATM: EXPERIMENTAL STUDY IN A JSR AND DETAILED CHEMICAL KINETIC MODELING

International audienceThe kinetics of oxidation of 1-methylnaphthalene have been studied in a jet stirred reactor (800 ≤ T/K ≤ 1421, 1 ≤ P/atm ≤ 10, 0.5 ≤ equivalence ratio ≤ 1.5). Molecular species concentration profiles of reactants, stable intermediates and final products were measured by sonic probe sampling followed by on-line GC-MS analyses and off-line GC-TCD-FID and GC-MS analyses. The oxidation of 1-methylnaphthalene was modeled using a detailed chemical kinetic reaction mechanism (146 species and 1041 reactions, most of them reversible). The proposed kinetic scheme was also validated simulating ignition delay times of 1-methylnaphthalene/air mixtures taken from the literature. Sensitivity analyses were performed and reaction path analyses, based on rates of reaction, were used to interpret the results

The oxidation of a diesel fuel at 1–10atm: Experimental study in a JSR and detailed chemical kinetic modeling

International audienceA good knowledge of the kinetics of the fuel combustion under high pressure is necessary for predicting the performances of modern diesel and HCCI engines and pollutants emissions.The kinetics of oxidation of a synthetic diesel fuel was studied in a jet-stirred reactor (JSR) at pressures extending from 1 to 10 atm, in the temperature range 800–1400 K, and for equivalence ratios in the range 0.5–2.0. The concentration profiles of molecular species, reactants, stable intermediates, and products, were measured by sonic probe sampling followed by on-line GC-MS-FID analyses, and off-line GC-TCD-FID and GC-MS analyses. The experiments were modeled using a detailed kinetic reaction mechanism consisting of 2755 reversible reactions and 377 species. The chemical surrogate model-fuel used consisted of a mixture of n-hexadecane (36.1% by weight, 23.5% vol.), n-propylcyclohexane (23.1% w, 26.9% vol.), n-propylbenzene (18.7% w, 22.9% vol.), iso-octane (14.7% w, 19% vol.), and 1-methylnaphthalene (7.4% w, 7.7% vol.). The proposed kinetic reaction mechanism used in the modeling yielded a good representation of the kinetics of oxidation of a synthetic diesel fuel under JSR conditions. Reaction path analyses were used to delineate the most important reaction paths during the oxidation of the fuel

Quantitative measurements of species and temperature in a DME-air counterflow diffusion flame using laser diagnostic methods

A diffusion flame of dimethyl ether (DME) and air in a counterflow burner has been investigated experimentally by means of different laser-based methods. Quantitative measurements of temperature, O-2 concentration, and OH concentration have been carried out using dual broadband rotational coherent anti-Stokes Raman Spectroscopy (CARS), Rayleigh scattering and laser-induced fluorescence (LIF). Furthermore a qualitative formaldehyde profile has been measured using LIF. The measured profile has been compensated for fluorescence signal quenching and the Boltzmann distribution to obtain a representative qualitative formaldehyde profile for the flame

Strategies for formaldehyde engines using a single-mode detection in flames and Nd : YAG/OPO laser system

This paper presents technical developments for the detection of formaldehyde (CH2O) using laser-induced fluorescence. The easily accessible third harmonic of the Nd:YAG laser at 355 nm was used for excitation of formaldehyde. In order to investigate potential background fluorescence, e.g., from large molecules such as polyaromatic hydrocarbons, special attention was paid to investigating the possibility of scanning the wavelength of a single-mode Nd:YAG laser under the gain profile, similar to 3 cm(-1), on and off resonance. Furthermore, a technique for simultaneous detection of formaldehyde and 011 using one laser system is presented. The single-mode Nd:YAG laser at 355 nm in combination with an optical parametric oscillator (OPO) laser tuned to 283 nm was used for simultaneous two-dimensional imaging of both species using one charge-coupled device (CCD) detector equipped with a dual filter image separator. The techniques are demonstrated with measurements in laboratory flames and the combined measurements are also demonstrated in an engine

Strategies for formaldehyde detection in flames and engines using a single-mode Nd : YAG/OPO laser system

Technical developments for the detection of formaldehyde using laser-induced fluorescence were presented. A technique for simultaneous detection of formaldehyde and OH using one laser system was presented. The combined formaldehyde and OH technique was applied in laboratory flames and a small spark-ignition engine. The iodine measurement was performed in a cell using the second harmonic of the single-mode Nd:YAG laser and used for wavelength calibration of the laser. Spectral studies of the fluorescence emission indicated that both the peaks as well as the continuous part originated from formaldehyde. This is an abstract of a paper presented at the 30th International Symposium on Combustion (Chicago, IL 7/25-30/2004)

Strategies for formaldehyde detection in flames and engines using a single-mode Nd:YAG/OPO laser system

This paper presents technical developments for the detection of formaldehyde (CH2O) using laser-induced fluorescence. The easily accessible third harmonic of the Nd:YAG laser at 355 nm was used for excitation of formaldehyde. In order to investigate potential background fluorescence, e.g., from large molecules such as polyaromatic hydrocarbons, special attention was paid to investigating the possibility of scanning the wavelength of a single-mode Nd: YAG laser under the gain profile, ∼3 cm-1, on and off resonance. Furthermore, a technique for simultaneous detection of formaldehyde and OH using one laser system is presented. The single-mode Nd: YAG laser at 355 nm in combination with an optical parametric oscillator (OPO) laser tuned to 283 nm was used for simultaneous two-dimensional imaging of both species using one charge-coupled device (CCD) detector equipped with a dual filter image separator. The techniques are demonstrated with measurements in laboratory flames and the combined measurements are also demonstrated in an engine