Search results for "Mixing"
showing 10 items of 795 documents
(Vapour + liquid) equilibria of (water + dimethylformamide): application of the headspace-gas chromatography for the determination of thermodynamic i…
1998
Abstract Isothermal measurements of the partial vapour pressures have been carried out on {water + dimethylformamide (DMF)} at temperatures betweenT=305.15 K andT=323.15 K using an apparatus composed of a headspace sampler and a normal gas chromatograph. These data were simultaneously evaluated in one step with respect to the (composition dependent, integral) Flory-Huggins interaction parametergby means of a new method which minimizes the Gibbs energy of mixing and does not require chemical potentials. The expression forggiven by Koningsveld and Kleintjens, originally designed for polymer solutions, describes the present results best.
Organic Compounds Evaluation from Fumes Generated in Laboratory by Bio-recycled Asphalt Mixtures
2021
Using bio-binder and bio-additives as recycling agents for asphalt mixtures with high-content of reclaimed asphalt (RA) is proving to be feasible. It is still not clear whether this combination might provide new hazardous emissions from airborne binder fumes. The health hazard related to airborne bitumen fume generation is primarily relevant for paving crews while there is little opportunity for exposure related to asphalt plant workers. In this study, measurements of gaseous organic compounds from airborne binder fumes of selected bio-asphalt mixtures have been measured during the laboratory mixing process, by using a thermo-mixer equipped with a chimney at Univ Gustave Eiffel. Parameters …
Organic Compounds Evaluation from Fumes Generated in Laboratory by Bio-recycled Asphalt Mixtures
2021
Using bio-binder and bio-additives as recycling agents for asphalt mixtures with high-content of reclaimed asphalt (RA) is proving to be feasible. It is still not clear whether this combination might provide new hazardous emissions from airborne binder fumes. The health hazard related to airborne bitumen fume generation is primarily relevant for paving crews while there is little opportunity for exposure related to asphalt plant workers. In this study, measurements of gaseous organic compounds from airborne binder fumes of selected bio-asphalt mixtures have been measured during the laboratory mixing process, by using a thermo-mixer equipped with a chimney at University Gustave Eiffel. Param…
On the measurement of local gas hold-up, interfacial area and bubble size distribution in gas–liquid contactors via light sheet and image analysis: I…
2013
Abstract In this work a novel experimental technique for measuring local gas hold-up, interfacial area and bubble size distribution, in gas–liquid systems is proposed. The technique is based on advanced Image Processing coupled with experimental set-ups typically available for Particle Image Velocimetry. A fluorescent dye dissolved in the liquid phase allows to identify in-plane bubbles among all visible bubbles in the images. To this end, a suitable algorithm is proposed. The raw data so obtained are processed by previously developed statistical methods that result in a reliable reconstruction of actual dispersion properties. The technique is applied to the case of a gas-dispersed mechanic…
Solid–Liquid Suspensions in Top-Covered Unbaffled Vessels: Influence of Particle Size, Liquid Viscosity, Impeller Size, and Clearance
2014
Particle suspension in liquids is a unit operation commonly encountered in the process industry. Although it is usually carried out in baffled stirred tanks, there are some specific applications where the presence of baffles may be undesirable. In the present work solid-liquid suspensions are investigated in a radially stirred unbaffled tank provided with a top cover. The minimum impeller speed at which all solid particles get suspended (Njs) and the relevant power requirements (Pjs) are assessed. The dependence of these two parameters on physical properties (liquid viscosity, particle concentration, and size) and system geometrical configurations (impeller diameter and clearance) is invest…
On the bubbling dynamics of binary mixtures of powders in 2D gas-solid fluidized beds
2012
Abstract The bubbling behavior of fluidized beds has been thoroughly investigated in the last decades by means of several techniques (e.g. X-ray, Inductance, Resistance and Impedance based techniques). In recent years, Digital Image Analysis Techniques have shown their potential for accurate and cost effective measurements. Most of the works related to the experimental analysis of bubble behavior in the field of gas-solid fluidization actually deal with monodispersed particles although almost all industrial equipments operate with mixtures of particles. Among the works available in literature dealing with mixtures of particles having different diameters and/or densities, most of them aim at…
Kerr self-cleaning of pulsed beam in an ytterbium doped multimode fiber
2017
International audience; We experimentally demonstrate that Kerr spatial self-cleaning of a pulsed beam can be obtained in an amplifying multimode optical fiber. An input peak power of 500 W only was sufficient to produce a quasi-single-mode emission from the double-clad ytterbium doped multimode fiber (YMMF) with non-parabolic refractive index profile. We compare the self-cleaning behavior observed in the same fiber with loss and with gain. Laser gain introduces new opportunities to achieve spatial self-cleaning of light in multimode fibers at a relatively low power threshold.
Searches for heavy neutrinos from Z decays
1992
We have searched for possible fourth family heavy neutrinos, pair produced in Z0 decays, in a sample of about 112 000 hadronic Z0 final states collected with the DELPHI detector. For all mixing matrix elements we exclude a new Dirac neutrino lighter than 44.5 GeV at a 95% confidence level, if the neutrino couples to the electron or muon family, and lighter than 44.0 GeV, if the neutrino couples to the tau family. Depending on the values of the mixing element and to which lepton family the neutrino couples, we obtain mass limits up to 46.2 GeV. For all mixing matrix elements we exclude a new Majorana neutrino lighter than 39.0 GeV, if it couples to the electron or the muon family, and lighte…
Analyse et Estimations Spectrales des Processus alpha-Stables non-Stationnaires
2006
In this work a new spectral representation of a symmetric alpha-stable processes is introduced. It is based on a covariation pseudo-additivity and Morse-Transue's integral with respect to a bimesure built by using pseudo-additivity property. This representation, specific to S$\alpha$S processes, is analogous to the covariance of second order processes. On the other hand, it generalizes the representation established for stochastic integrals with respect to symmetric alpha-stable process of independent increments. We provide a classification of non-stationary harmonizable processes; this classification is based on the bimesure structure. In particular, we defined and investigated periodicall…
Contribution à l'estimation non paramétrique des quantiles géométriques et à l'analyse des données fonctionnelles
2008
In this dissertation we study the nonparametric geometric quantile estimation, conditional geometric quantiles estimation and functional data analysis. First, we are interested to the definition of geometric quantiles. Different simulations show that Transformation-Retransformation technique should be used to estimate geometric quantiles when the distribution is not spheric. A real study shows that, data are better modelized by geometric quantiles than by marginal one's, especially when variables that make up the random vector are correlated. Then we estimate geometric quantiles when data are obtained by survey sampling techniques. First, we propose an unbaised estimator, then using lineari…