The scattering matrix for size distributions of irregular particles: An application to an olivine sample
نویسندگان
چکیده
We have compared simulated and measured scattering matrices of a size distribution of olivine particles at wavelengths of 633 and 442 nm. The computations were carried out for size distributions of irregularly-shaped compact particles with different average projected areas using the discrete-dipole approximation (DDA). The results of the comparison show that the model of irregularly-shaped particles mimic the observations far better than the results given by spheres, spheroids or rectangular prisms having a wide range in aspect ratios. The computed scattering matrices for size distributions of irregularly-shaped particles do not depend very strongly on the precise particle shape assumed, providing a method to infer certain physical properties of an ensemble of natural dust particles, such as the refractive index, when some information on the sample, as the size distribution, is known a priori. r 2005 Elsevier Ltd. All rights reserved.
منابع مشابه
Experimental determination of scattering matrices of olivine and Allende meteorite particles
We have measured the scattering matrix as a function of the scattering angle of randomly oriented particles of a Mg-rich olivine sample and a ground piece of Allende meteorite as cometary analogues using lasers at two wavelengths (442 nm and 633 nm). The elements of the scattering matrix, Fij , depend on the scattering angle, the wavelength of the laser light, and on the size, shape and refract...
متن کاملDetermination of the size distribution of monodesperse and bidisperse mixtures of spherical particles in the nanometer and submicron size range by applying cumulant analysis and contin algorithm in dynamic light scattering
Determination of particle size is one of the major needs in the industry and biotechnology. Dynamic light scattering (DLS) is a widely used technique for determining size distribution of spherical particle in nanometer and submicron size range. In this method, there are different algorithms for determining the size and size distribution of particles, which are selected according to the required...
متن کاملStudy of the sensitivity of size-averaged scattering matrix elements of nonspherical particles to changes in shape, porosity and refractive index
Studies of the physical parameters that influence the single scattering properties of a size distribution of small particles in random orientation are fundamental in understanding the origin of the observed dependence of the scattering matrix elements on the scattering angle. We present results of extensive calculations of the single scattering matrices of small nonspherical particles performed...
متن کاملEFFECT OF NOZZLE DIAMETER AND ATOMIZING AIR PRESSURE ON CHARACTERISTICS OF IN-FLIGHT PARTICLES IN WIRE ARC SPRAYING
In wire arc spraying, the atomizing air pressure and applied nozzle system are important factors influencing particles characteristics and coating quality. The aim of this paper is to study how the characteristics of particles such as size, velocity and temperature are influenced by the operating conditions in wire arc spray. For that, three types of wires are tested: solid wire of stainless st...
متن کاملEIGENVECTORS OF COVARIANCE MATRIX FOR OPTIMAL DESIGN OF STEEL FRAMES
In this paper, the discrete method of eigenvectors of covariance matrix has been used to weight minimization of steel frame structures. Eigenvectors of Covariance Matrix (ECM) algorithm is a robust and iterative method for solving optimization problems and is inspired by the CMA-ES method. Both of these methods use covariance matrix in the optimization process, but the covariance matrix calcula...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006