Rotation Of Rods Research Articles

Entanglements of semidilute polymer rods.

Brownian simulations of semidilute rods confirm that rotation of rods is ordinarily confined to cages which break up through diffusion along rod axes. However, the angular width of the cages is proportional to $\frac{1}{{(c{L}^{3})}^{p}}$ is the rods are thin, with $p=\frac{1}{2}$ rather than the previously supposed $p=1$. The latter result is found only for rods at true equilibrium, which cannot occur unless cage topology equilibrates as fast as cage size.

The flow of suspensions through tubes VII. Rotation and deformation of particles in pulsatile flow

A study of the translation and rotation of rigid spheres, rods, and discs, as well as the deformation of fluid drops in pulsatile and oscillatory flows, was made. Except when within one particle diameter of the wall, the axial displacements of small spheres, rods, and discs in oscillatory flow were in agreement with the theory of Womersley, and in pulsatile flow could be predicted by the superposition of the oscillatory on the steady flow. The rotations of the cylinders were in accord with theory based on slow steady flow when the fluctuating velocity gradient of the undisturbed field was used. When the particles were very close to the wall, however, both translational and rotational slip were observed, the degree of slip being similar to that found in steady flow. The oscillating deformation and orientation of liquid drops of low viscosity were found to be in agreement with calculations based on the theory for steady flow. When the drop viscosity became appreciable, however, the deformation lagged the velocity gradient owing to the dissipation of energy in extensional viscous flow within the drop.

Energy Concentration Effects in Ferrite Loaded Wave Guides

The primary objective of this study was to determine the effects of geometric parameters on microwave transmission characteristics for two counter-rotating circularly polarized waves in ferrite loaded wave guide. Ferrite rods were mounted coaxially in circular wave guide of 0.934 in. diameter. Effects of rod diameter and length were observed on reflection, phase shift or Faraday rotation, and ellipticity. Effects of frequency and applied magnetic field were observed in addition to differences in energy concentration in a ferrite for the two circular waves. A greater percentage of the microwave energy is found to be in the ferrite for one rotating component than for the other. It is shown that Faraday rotation of large diameter rods cannot be used to characterize ferrites accurately.