The effect of a slit-like confinement on the relaxation dynamics of DNA is studied via a mesoscale model in which a bead and spring model for the polymer is coupled to a particle-based Navier-Stokes solver (multi-particle collision dynamics). The confinement is found to affect the equilibrium stretch of the chain when the bulk gyration radius is comparable to or smaller than the channel height ...

The rate of escape of an ideal bead-spring polymer in a symmetric double-well potential is calculated using transition state theory (TST) and the results compared with direct dynamical simulations. The minimum energy path of the transitions becomes flat and the dynamics diffusive for long polymers making the Kramers-Langer estimate poor. However, TST with dynamical corrections based on short ti...

The hydrodynamic interaction is an essential effect to consider in Brownian dynamics simulations of polymer and nanoparticle dilute solutions. Several mathematical approaches can be used to build Brownian dynamics algorithms with hydrodynamic interaction, the most common of them being the exact but time demanding Cholesky decomposition and the Chebyshev polynomial expansion. Recently, Geyer and...

A number of welding parameters are responsible for the quality of welds. The modeling of weld bead shape is important for predicting the quality of welds. In this paper, an attempt has been made to develop a back-propagation neural network (BPNN) model for the prediction of reinforcement height and width of bead in GTA bead-on plate welding process. The experimental results were used as testing...

In the present study, textural and structural characterizations of chitosan bead for immobilization of alpha amylase were studied in detail by N2 adsorption–desorption, Microspore Analysis (MP), Barrett–Joyner–Halenda (BJH) plots and Field Emission Scanning Electron Microscope (FESEM) observations. Pore structure observation revealed chemical activation of chitosan bead by glutaralde...

Nonequilibrium molecular dynamics simulations are applied to investigate the rheological properties of coplanar nanopore systems of amphiphilic chain molecules with the tails grafted to the walls of the nanopore and with the head-group ends immersed in a solvent inside the nanopore. In particular, the effects of modifying the interaction between the amphiphilic head-groups by repulsive dipolar ...

The Flory–Huggins χ parameter describes the excess free energy of mixing and governs phase behavior for polymer blends and block copolymers. For chemically-distinct nonpolar polymers, the value of χ is dominated by the mismatch in cohesive energy densities of the monomers. For blends of chemically-similar polymers, the entropic portion of χ, arising from non-ideal local packing, becomes more si...

We prove the existence of large-data global-in-time weak solutions to a general class coupled bead-spring chain models with finitely extensible nonlinear elastic (FENE) type spring potentials for nonhomogeneous incompressible dilute polymeric fluids in bounded domain $ \mathbb{R}^d $, d = 2 or 3 $. The under consideration involves Navier–Stokes system variable density, where viscosity coefficie...

The conformations of semiflexible polymers in two dimensions confined in a strip of width D are studied by computer simulations, investigating two different models for the mechanism by which chain stiffness is realized. One model (studied by molecular dynamics) is a bead-spring model in the continuum, where stiffness is controlled by a bond angle potential allowing for arbitrary bond angles. Th...