The molecular weight dependence of the radii of gyration Rg in a Θ solvent (trans-decalin) of one regular branched comb and three regular centipede polystyrenes was studied using a gel permeation chromatography system equipped with a two-angle light scattering detector and a refractive index detector. Rg in trans-decalin for each sample of particular molecular weight was about 25% smaller than ...

We review recent theoretical studies on the statistical and dynamical properties of polymers with nontrivial structures in chemical connectivity and those of polymers with a nontrivial topology, such as knotted ring polymers in solution. We call polymers with nontrivial structures in chemical connectivity expressed by graphs “topological polymers”. Graphs with no loop have only trivial topology...

Detailed investigation of static light scattering (SLS) has been attempted in this work using dilute water dispersions of homogenous spherical particles, poly(N-isopropylacrylamide) microgels and simulated data. When Rayleigh-Gan-Debye approximation is valid, for large particles, the simple size information, the static radius Rs and distribution G (Rs), can be accurately obtained from SLS. For ...

UNLABELLED Molecular dynamic simulation is a practical and powerful technique for analysis of protein structure. Several programs have been developed to facilitate the mentioned investigation, under them the visual molecular dynamic or VMD is the most frequently used programs. One of the beneficial properties of the VMD is its ability to be extendable by designing new plug-in. We introduce here...

A large 12S RNA fragment which constitutes the 5' two-thirds of 16S-RNA from the E. coli 30S subunit has been investigated by small-angle X-ray and neutron scattering. The results indicate that in reconstitution buffer the 12S-RNA fragment has a molecular weight of 270,000 +/- 20,000 and a radius of gyration of 7.1 nm. The scattering data are compatible with the RNA being folded into two major ...

An algorithm is presented to fit precipitates in atom probe tomographic data sets as equivalent ellipsoids. Unlike previous techniques, which measure only the radius of gyration, these ellipsoids retain the moments of inertia and principle axes of the original precipitate, preserving crystallographic orientational information. The algorithm is applied to study interconnected γ-precipitates (L12...

Disk imbalance is a condition in which the center of mass of a rotating disk is not coincident with the center of rotation. Imbalance in a rotor system is unavoidable and it cannot be completely eliminated. Due to some reasons, such as porosity in casting, non-uniform density of material, manufacturing tolerances, and gain or loss of material during the operation, there is imbalance in rotors. ...

All-atom molecular dynamics (MD) simulations were performed to study the effects of different tetraalkylammonium (TAA(+)) counterions, including tetramethylammonium (TMA(+)), tetraethylammonium (TEA(+)), tetrapropylammonium (TPA(+)) and tetrabutylammonium (TBA(+)), on dodecyl sulfate (DS(-)) micelles. Structural properties, such as the radius of gyration (Rg), micelle radius (Rs), micelle size,...