Cylindrical samples of ice with 0.0 to 0.35 volume fraction fine sand were tested in unconfined uniaxial compression at stresses between 5.3 and 6.4 bar and at temperatures between −7.4 and −9.4° C. Secondary creep rates were obtained from the slope of the total strain vs. time curve and were normalized to 5.6 bar and −9.1° C. Creep rates in ice with low sand concentrations were in some cases higher and in other cases lower than in clean ice. However at higher sand concentrations the creep rate decreases exponentially with increasing volume fraction sand. The latter results are in general agreement with theories developed to explain dispersion hardening of metals, and suggest that each sand grain is surrounded by a tangled network of secondary dislocations which impede passage of primary glide dislocations.

ABSTRACT. Cylindrical sa mples of ice with 0.0 to 0.35 volume fraction fine sand were tested in un confin ed un iaxial compression at stresses between 5.3 and 6.4 bar and a t tem peratures between -7.4 a nd -9.4° C. Secondary c reep ra tes were obtained from the slope 0(' the total stra in vs. time curve and were normalized to 5.6 bar and -g. 1 0 C. Creep rates in ice with low sand concentra tions were in some cases bigber a nd in otber cases lower tban in clean ice. H owever at high er sand concentrations the creep rate decreases exponentiall y with inc reasing volu me frac tion sa nd . Tbe la tter results a re in general agreement with theories d eveloped to expla in dispersion hard ening of metals, and suggest tbat eac h sand grain is surrounded by a tangled network of second ar y disloca tions which impede passage of prima ry glide dislocations. R ESUME. FIlIage de la glace con tenant un sable fin en dispersion. On a tes te d es ec han tillo ns cylindriques de glace contenant 0,0 a. 0,35 fois son volume de sabl e fin en les soumettant a une compression uniaxia le comprise entre 5,3 et 6,4 bar et a un e temperature comprise entre -7,4 et -9,4° C. La vitesse de Auage second a ire fut o btenue a. partir de la pente de la courbe d onn an t la deform a ti on to tale en fon ction du tem ps et fut normalisee a. donn er la vitesse a. 5,6 bar e t -g, 1 0 C. L es vitesses d e Auage dans la glace a. fa ible concentration

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First results on contained neutrino interactions are presented from the Soudan 2 proton decay experiment. 20 neutrino events have been found in a fiducial exposure of 0.29 kton years.