The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 26, 1996
Filed:
Aug. 20, 1990
Darrell K Hutchins, Conway, AR (US);
Barton E Dahneke, Palmyra, NY (US);
Board of Trustees of the University of Arkansas, Little Rock, AR (US);
Abstract
A new class of methods for characterizing particles is described along with associated apparatuses. These methods are called modulated dynamic light scattering (MDLS) methods because they utilize time and space modulations of the incident or scattered light as well as modulations caused by random Brownian motions of the particles, for example, to measure particular properties. The autocorrelation function of the scattered light signal from a particle is measured to provide a highly resolved signature even when the signal is buried in noise. The dynamics of the scattered light signal from a suspended particle undergoing random Brownian translations and rotations is analyzed to obtain the relationship of the particle's properties to its autocorrelation function signature. By comparison of the theoretical and measured functions, properties of a particle suspended in a (1) liquid, (2) gas, or (3) rarefied gas can be determined. In cases (1) and (2) the general shape category, velocity, and translational friction coefficient of the particle and in case (3) these properties and the mass of the particle are determined. The particle charge and charge-to-mass ratio can also be determined in cases (2) and (3). In addition, other analytical techniques can also be used to determine information about the chemical and biological nature of the particle. Distributions of particles over one or more properties, singly or jointly, can then be precisely determined from a large number of individual particle measurements and particles of a species having a unique set of properties can be individually identified.