As described in the previous chapters, optical tweezers have become a tool of precision for in vitro single-molecule investigations, where the single molecule of interest most often is studied in purified form in an experimental assay with a well-controlled fluidic environment. A well-controlled fluidic environment implies that the physical properties of the liquid, most notably the viscosity, ...

Linear viscoelastic properties for a dilute polymer solution are predicted by modeling the solution as a suspension of non-interacting bead-spring chains. The present model, unlike the Rouse model, can describe the solution’s rheological behavior even when the solvent quality is good, since excluded volume effects are explicitly taken into account through a narrow Gaussian repulsive potential b...

The linear viscoelastic behaviors of single semiflexible chains with internal friction are studied based on the wormlike-chain model. It is shown that the frequency dependence of the complex compliance in the high frequency limit is the same as that of the Voigt model. This asymptotic behavior appears also for the Rouse model with internal friction. We derive the characteristic times for both t...

In polymeric gels, basically two species of cross-links exist: those contributing to the network and those that don’t. Zhou et al. (1) suggested network disassembly spectrometry to determine the content of loops— the simplest kind of network defects in gels. Although cross-links contributing to the network hold the gel together and are thus desirable, the noncontributing links (e.g., the loops ...

We give a space-time Galerkin nite element discretization of the linear quasistatic compressible viscoelasticity problem as described by an elliptic partial diierential equation with a Volterra (memory) term. The discretization consists of a continuous piecewise linear approximation in space with a discontinuous piecewise constant or linear approximation in time. We derive an a priori maximum-e...

We summarize different studies describing mechanisms through which bacteria in a biofilm mode of growth resist mechanical and chemical challenges. Acknowledging previous microscopic work describing voids and channels in biofilms that govern a biofilms response to such challenges, we advocate a more quantitative approach that builds on the relation between structure and composition of materials ...

A numerical solution for the free convective, unsteady, laminar convective heat and mass transfer in a viscoelastic fluid along a semi-infinite vertical plate is presented. The Walters-B liquid model is employed to simulate medical creams and other rheological liquids encountered in biotechnology and chemical engineering. This rheological model introduces supplementary terms into the momentum c...

Dynamic and creep behavior of 80In15Pb5Ag and 50Sn50Pb were studied isothermally over nine decades of time and frequency. 80In15Pb5Ag was examined at 26, 21, and 50 °C, and 50Sn50Pb was examined at 21 °C. Viscoelastic behavior was observed at strains less than 10 as a function of temperature and time/frequency. At the small strain used in the study, the alloys exhibit linear viscoelasticity rat...

For taking accurate impressions, many material characteristics of the impression materials must be well understood. It is especially important to analyze the viscoelastic behavior of the impression materials. In our study, seven commercial alginate impression materials were used, and their linear viscoelasticity was measured using a creep meter (RE-3305, Yamaden Co.). The measurement condition ...