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It was demonstrated that pharmacological alteration of coagulating whole blood can influence the mechanical properties of the clot and can be assessed rheologically. The clot viscoelasticity was measured in a Weissenberg Rheogoniomcter as a function of the concentration of anticoagulant sodium heparin. The storage component of the elastic modulus was seen to be significantly and reproducibly lowered by heparin. Variation between donors was found to be minimized by adjustment of hematocrit, platelet count, and fibrinogen content to common values.

1.Reactive diffusion in a mixture of copper and aluminum powders and in a Cu-Al bimetal results in the formation of an intermediate layer composed of new phases arranged between the aluminum and the copper in the following order;? (CuAl2), ?2 (CuAl), and ?2 (Cu2Al).2.The kinetics of growth of the individual phases and the layer as a whole in a mixture of copper and aluminum powders and a Cu-Albimetal obeys the parabolic law X2=K(t-t0). The latent period of a powder mixture is a very short, and the energy of activation for phase growth in it is approximately 1.5 times that in a bimetal. During the annealing of a powder mixture for long period of time, deviations from a parabolic law are observed, which are due to dissolution processes at the phase interfaces and the presence of only a limited amount of aluminum participating in diffusion.3.The high reactivity of a powder mixture ensures that the rate of? phase growth at all temperatures is higher in such a mixture than in a bimetal. The rates of growth of the whole layer and the ?2+?2 phase layer in a powder mixture and a bimetal are approximately equal. The initial porosity of specimens and the presence of oxides on the surfaces of powder particles, which determine the area and degree of contact between dissimilar particles, exert a strong influence upon the rate of phase growth during reactive diffusion.