Dagmara Sokolowska

Pendulum viscometer: A new method for measurement of Miȩsowicz nematic shear viscosity coefficients η1 and η2

We describe a new viscometer developed for liquid crystals. It has been designed for measurement of the Miesowicz viscosity coefficient η2 (n‖v) in particular, but can be used for measuring η1 (n‖∇v) as well. The measurement is based on observation of the damped motion of a pendulum and derivation of the viscosity coefficient from the damping constant.

Dehydration kinetics and conductivity scaling in time near the continuity failure of a water wetting film in granular media

We found that in wet biological and manmade granular materials drying freely to ambient air, dehydration kinetics is quite linear in time in the proximity to the thin, quasi-2D aqueous layer continuity threshold. Electric conductivity of the film scales like a power of time-to-failure. The scaling exponent is to within more or less 15% the same as the corresponding exponent for conductivity scaling with the sample hydration.

Note: Optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems

A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time.