METHOD TO DETERMINE SPEED OF GRAVITY SEDIMENTATION OF PARTICLES OF FLUE DUST IN EMISSIONS OF INDUSTRIAL ENTERPRISES IN ATMOSPHERIC BOUNDARY LAYER Russian patent published in 2015 - IPC G01N23/222 

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of research or analysis of materials with the help of neutron-activation analysis of mosses-biomonitors. The method consists in the fact that in the specified direction from an industrial enterprise at different distances from 1 to 5 km they take at least 5 samples of epiphytic moss Pylaisia polyantha (Hedw.) B.S.G. from bark of birches, aspens and poplars at the height of 1.5-2 m. Besides, one moss sample is selected on a background territory with natural-climatic conditions, identical with the researched territory, and located at the distance of more than 100 km from industrial centres in direction opposite to the preferential wind rose. Moss samples are cleaned from foreign admixtures, washed with distilled water, dried at temperature from 80 to 100°C, homogenized. From 5 to 10 parallel representative samples are made, exposed to radiation with a flux of thermal neutrons for not more than 5 hours. After reduction of activities of Na²⁴ to safe level they determine specific activity of each sample by comparison of intensity of gamma lines of radio nuclides of chemical elements in a sample with intensity of gamma lines of standards. Values of concentrations of chemical elements in moss samples determined with the help of neutron-activation method, by method of least squares are approximated by the specified dependence, determining at the same time numerical values of coefficients included into it, and then speed of gravity sedimentation of flue dust particles is calculated in emissions of an industrial enterprise in an atmospheric boundary layer from the specified ratio.

EFFECT: invention provides for increased validity and reliability of determination.

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