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We have measured the flow-induced shift in the NMR spectrum of /sup 3/He-B. Above a temperature-independent critical velocity, the absorption line is observed to shift to higher frequencies as the flow is increased, in qualitative agreement with the theory of textural deformation in the presence of flow due to Fetter.

We present the first measurements at millikelvin temperatures of both the real and the imaginary parts of the transverse-acoustic impedance of an oscillating surface in contact with dilute solutions of $^{3}\mathrm{He}$ in $^{4}\mathrm{He}$, as well as with pure $^{3}\mathrm{He}$ with and without a surface boundary layer of $^{4}\mathrm{He}$. Except for pure $^{3}\mathrm{He}$, large departures from hydrodynamic behavior are found which are inconsistent with slip theories incorporating specular scattering at the boundary. The effects of the $^{4}\mathrm{rich}$ surface boundary layer and of surface roughness are discussed.

Measurements are reported which relate to the dissipation and superfluid density of /sup 3/He-A and /sup 3/He-B flowing through a long rectangular channel of cross section 48 ..mu..m x 2.86 mm at currents between 5 x 10/sup -2/ g cm/sup -2/ sec/sup -1/ and 5 x 10/sup -5/ g cm/sup -2/ sec/sup -1/ and at temperatures down to T/T/sub c/=0.52. The results show a complex velocity dependence in both phases.

dc flow of superfluid /sup 3/He-B through a rectangular superleak exhibits two dissipative regimes and two critical currents with temperature dependence of the form J/sub c/ = b(1-T/T/sub c/)/sup a/. At low pressures aapprox. =(3/2) and b increases with pressure. Around 21.5 bars a crossover occurs to a new dissipation regime with aapprox. =2 and the prefactor b then decreases with pressure.

We have made detailed measurements of the effective viscosity of dilute ${\mathrm{He}}^{3}$-${\mathrm{He}}^{4}$ solutions between 20 mK and 1 K, by observation of the damping of torsional oscillations of a quartz crystal. The results are strikingly different, in magnitude and in temperature dependence, from theoretical predictions and from previous preliminary results.