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Mie Scattering (mie + scattering)
Selected AbstractsColor and Golden Shine of Silver Islamic LusterJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2010P. Carolina Gutierrez Golden-like luster decorations on glazed ceramics from early Islamic times (9,12th centuries AD) consist of a nanocomposite submicrometric layer made of silver metal nanoparticles. The color and golden-like reflectivity of these decorations are dominated by the nonlinear optical response and Mie scattering of the silver nanoparticles. We demonstrate that the enhanced golden-like reflectivity occurs only for dense nanoparticulated layers and that they were obtained by adding PbO to the alkaline glaze. This resulted in reduced diffusivity of silver in the glaze leading to more concentrated and thinner luster layers that formed closer to the glaze surface. The result obtained adds new insights into the high technological level attained during Islamic times and also has important historical implications, giving both new clues concerning the lead enrichment of the glazes during this period, and some basis for the medieval Alchemy search for the production of "gold" from other metals. [source] Size Measurement of Very Small Spherical Particles by Mie Scattering Imaging (MSI)PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 5 2004Arne Graßmann Abstract The Mie Scattering Imaging method (MSI) gathers out-of-focus images of dispersed spherical particles present in a laser light sheet and extracts the individual particle diameter from these images. The general idea of the method has been around for more than a decade and a number of papers has dealt with it over recent years. Our work focuses on small particle sizes from 20 ,m down to 2 ,m, a range which has not been tackled so far although it is of great importance in particle systems. We present an optical set-up with a special arrangement of camera lenses that allows to work in this range. An evaluation algorithm based on correlation of the experimental optical information with theoretical Mie scattering was found to give the most accurate results for particle sizing. Besides accuracy measurements on solid spheres the versatility of the method is demonstrated by an example of transient droplet growth between 2,7,,m. [source] Planar Droplet Sizing for the Characterization of Droplet Clusters in an Industrial Gun-Type BurnerPARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 3 2003Laurent Zimmer Abstract An important problem in spray combustion deals with the existence of dense regions of droplets, called clusters. To understand their formation mechanism, the droplet dynamics and fuel concentration profile are investigated by means of planar laser techniques in an industrial gun-type burner. The simultaneous measurement of elastic Mie scattering and Laser Induced Fluorescence (LIF) allows the instantaneous measurement of the Sauter Mean Diameter (SMD), after proper calibration. Using two different CCDs to get the two signals requires a detailed calibration of the CCD response before getting absolute diameters. Pixels are binned 6 by 6 to obtain the final SMD map, this is a compromise between spatial accuracy and noise. Velocity field is measured on both sets of images using standard Particle Image Velocimetry (PIV) algorithms. The comparison of cross-correlation technique with PDA results shows that the velocity measured on the LIF images are close to the velocity based on D30, whereas the Mie scattering results are similar to D20. On Mie scattering images, regions of high interfacial area forming clusters can be detected. A special tracking scheme is used to characterize their dynamics in terms of velocity and diameters by ensuring that the same volume of fluid is tracked. It is shown that the clusters have a velocity similar to the velocity of droplets with the same diameter as the mean SMD of the cluster. It is also shown that an increase of pressure tends to trigger the appearance of such a group of droplets, due to a smaller diameter of the droplets caused by the increase of pressure discharge. Uncertainties for the different techniques used are discussed. [source] Optical Levitation of Single Microdroplets at Temperatures Down to 180 KCHEMPHYSCHEM, Issue 6 2003C. Mund A little light levitation: Optically transparent microdroplets can be levitated by means of the photon pressure exerted by a slightly focussed laser beam. The picture shows the forces operating on a particle during this process. The operation of this levitation techniques is reviewed on the basis of generalized Lorenz,Mie theory. The behaviour of levitated microparticles with respect to changes in composition and size can be investigated by Raman and Mie scattering. The feasibility of this technique for levitation studies down to 180 K is demonstrated. [source] | ||||||||||