Equilibrium Twist Research Articles

Effect of anisotropic bending rigidity and finite twisting rigidity on statistical properties of DNA model filaments.

AbstractThe persistence length and effective long‐range bending rigidity are derived for a discrete model of an anisotropically bending filament and shown to be independent of the torsional rigidity. The twisting persistence length is found to be independent of the anisotropic bending rigidity. Other statistical properties are briefly discussed, including the dependence of tangent vector projections on contour length. The dependence of a tensor contraction on contour length is derived for an isotropically bending filament with no equilibrium twist.

11–AN ALTERNATIVE APPROACH TO TWO-FOLD WEAVING YARN PART II: THE THEORETICAL MODEL

The theoretical model underlying a two-strand spinning system is given. It is shown that, for an idealized model, the equilibrium twist in the strands is dependent upon a torsion balance existing between an individual strand above the convergence point and the strand as it lies in th plied structure. As a consequence, at equilibrium, twist in the strands relies solely on ply-twist and the helix radius of the strands in the ply. Basic equations are derived that lead to a method of evaluating trapped strand-twist in the resultant yarn that is produced by changes in twist in the strands when equilibrium is deliberately perturbed.