Nonlinear rheological properties are often relevant in understanding the response of a material to its intended environment. For example, many gastropods crawl on a thin layer of pedal mucus using a technique called adhesive locomotion, in which the gel structure is periodically ruptured and reformed. We present a mechanical model that captures the key features of this process and suggests that...

We report the results of an investigation into the rheology of solutions of natural spider silk dope (spinning solution). We demonstrate that dilute dope solutions showed only shear thinning as the shear rate increased while more concentrated solutions showed an initial shear thinning followed by a shear thickening and a subsequent decline in viscosity. The critical shear rate for shear thicken...

(UFV), Viçosa, MG, Brazil (e-mail: [email protected]). ** DSc Food Science and Technology, Food Engineering Department, Universidade Federal do Espírito Santo (UFES), Alegre, ES, Brazil (e-mail: [email protected]). *** DSc Food Science and Technology, Food Technology Department, UFV, Viçosa, MG, Brazil (e-mail: [email protected]). **** MSc Food Science and Technology, Food Engin...

Tillage modifies the soil structure to create conditions favorable for plant growth. However, the resulting loose structure is susceptible to collapse by internal capillary forces and external compactive stresses with concurrent changes in soil hydraulic properties. Presently, limited understanding of these complex processes often leads to consideration of the soil plow-layer as a static porous...

The process of electrostatic extrusion as a method for cell immobilization was investigated that could be used for potential applications in medicine. An attempt was made to assess the effects of cell addition and polymer concentration on the overall entrapment procedure, ie, on each stage of immobilization: polymer-cell suspension rheological characteristics, electrostatic extrusion process, a...

background and objectives: kefiran (kef) is a water-soluble polysaccharide that can form transparent film however, it is brittle. therefore, in order to improve the mechanical properties of kefiran film, a mixture with other polymers can be offered. the expansion of mixed systems can propose kefiran and polyvinyl alcohol (pvoh) as a new composite film. materials and methods: solutions of 20 gra...

The aim of this study was to prepare an inclusion complex of acetaminophen and β-cyclodextrin (molar ratio of 1:1). A jelly with inclusion complexes formed by kneading was prepared. The formation of inclusion complexes was assessed by powder X-ray diffraction patterns and Fourier transform-infrared spectroscopy. Jellies were prepared with xanthan gum, gelatin, and κ-carrageenan. The concentrati...

This study demonstrates a two-step approach that enables quantification of concrete printability through dynamics mode rheological measurements; I) modeling shearing history during extrusion; II) monitoring the hardening evolution deposited material by applying strain smaller than critical strain. It is shown removed imposing pre-shearing above strain, and zero value yield stress measured for a...