20 research outputs found
Charge Fluctuation Forces Between Stiff Polyelectrolytes in Salt Solution: Pairwise Summability Re-examined
We formulate low-frequency charge-fluctuation forces between charged
cylinders - parallel or skewed - in salt solution: forces from dipolar van der
Waals fluctuations and those from the correlated monopolar fluctuations of
mobile ions. At high salt concentrations forces are exponentially screened. In
low-salt solutions dipolar energies go as or ; monopolar
energies vary as or , where is the minimal separation
between cylinders. However, pairwise summability of rod-rod forces is easily
violated in low-salt conditions. Perhaps the most important result is not the
derivation of pair potentials but rather the demonstration that some of these
expressions may not be used for the very problems that originally motivated
their derivation.Comment: 8 pages and 1 fig in ps forma
Celebrating the Centenary of Timoshenko's Study of Effects of Shear Deformation and Rotary Inertia
Coherent and spontaneous Rayleigh-Brillouin scattering in molecular gases and gas mixtures
We study Rayleigh-Brillouin scattering in gases of