Authors: Dobashi, T. | Idonuma, A. | Toyama, Y. | Sakanishi, A.
The enhanced rate of sedimentation of erythrocytes in an inclined rectangular vessel was measured under microscopic and macroscopic conditions. The velocity profile, V(x), and the thickness, δ , of the upflow layer generated below the downward-facing wall in the sedimentation vessel were measured under a microscope with polystyrene latex as a tracer particle. Here, x is the distance from the vessel wall. All the data of the velocity profile are represented by a single curve, [ V max − V ( x ) ] / V max
…= [ ( δ − x ) / δ ] 2 , irrespective of the volume fraction, H, and tilt angle, θ , in the range of 0.05 < H < 0.30 and 10°< θ < 40°, where Vmax is the maximum velocity found at the upflow boundary. The rate of fall of the top surface of the suspension v(H, θ ) fits the function, v ( H , θ ) = v ( 0 , θ ) ( 1 − H ) exp [ − ( aH + bH 2 ) ] , well, irrespective of H and θ . These experimental results are compared with the theory of Acrivos and Herbolzheimer.
Keywords: Erythrocyte sedimentation rate, Boycott effect, upflow layer, velocity profile, master curve
vol. 31, no. 4, pp. 383-393, 1994
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