Inverse integral transformation method to derive local viscosity distribution measured by optical tweezers.

Complex fluids have a non-uniform local inner structure; this is enhanced under deformation, inducing a characteristic flow, such as an abrupt increase in extensional viscosity and drag reduction. However, it is challenging to derive and quantify the non-uniform local structure of a low-concentration solution. In this study, we attempted to characterize the non-uniformity of dilute and semi-dilute polymer and worm-like micellar solutions using the local viscosity at the micro scale.

Contraction behaviors of sp. stalk investigated using high-speed video camera. II: Viscosity effect of several types of polymer additives.

The contraction process of living sp. in polymer solutions with various viscosities has been investigated by image processing using a high-speed video camera. The viscosity of the external fluid ranges from 1 to 5mPa·s for different polymer additives such as hydroxypropyl cellulose, polyethylene oxide, and Ficoll.

Contraction behaviors of sp. stalk investigated using high-speed video camera. I: Nucleation and growth model.

The contraction process of living sp. has been investigated by image processing using a high-speed video camera. In order to express the temporal change in the stalk length resulting from the contraction, a damped spring model and a nucleation and growth model are applied.