EFFECT OF DE-AWNING AND MOISTURE CONTENT ON SOME FRICTIONAL PROPERTIES OF PADDY

摘要

One of the specific traits of Iran’s local paddy varieties is the presence ofnawns at the tip of the lemma that cause difficulties in the grain flow throughnchutes and orifices. In this study, the effect of de-awning and moisture contentnof paddy on the angle of repose, coefficient of internal friction and coefficientnof mobility were evaluated as a function of moisture content in the range ofn7–23% dry basis (d.b.).nResults revealed that the effect of de-awning and moisture content onnfrictional properties of paddy was highly significant (P < 0.01). For awnednpaddy, the angle of repose increased from 37.42 to 45.70°; coefficient ofninternal friction increased from 0.453 to 0.574; the angle of internal frictionnfrom 24.37 to 29.85° and coefficient of mobility decreased from 0.415 to 0.335nas the paddy moisture content increased from 7.64 to 23.38% d.b. In thencase of de-awned paddy, the angle of repose increased from 34.46 to 42.68°;ncoefficient of internal friction from 0.427 to 0.512; the angle of internalnfriction from 23.11 to 27.10° and the coefficient of mobility decreased fromn0.430 to 0.370 at same range of moisture content