Effective viscosity of dispersions approached by a statistical continuum method

The problem of the determination of the effective viscosity of disperse systems (emulsions, suspensions) is considered. On the basis of the formal solution of the equations governing creeping flow in a statistically homogeneous dispersion, the effective viscosity is expressed in a series expansion in terms of correlation functions. The contribution of the interfacial tension to the effective viscosity is also considered and finally bounds for the effective viscosity are indicated

Ground state energies of antiferromagnetic lattices

Approximate values for the ground-state energy of one- and two-dimensional antiferromagnetic systems are determined with ceils of an even number of spins. The interaction between the cells is treated as a perturbation

The determination of the ground-state energy of an antiferromagnetic lattice by means of a renormalization procedure

An approximate value for the ground-state energy of an antiferromagnetic lattice of spins one-half is determined by means of a repeated renormalization procedure in which the lattice is divided into cells with an effective interaction. This effective interaction is determined on the basis of the spin-hamiltonian formalism

An exact upper bound for the ground-state energy of the triangular antiferromagnetic lattice by means of a renormalization procedure

A renormalization procedure gives rigorous upper bound for the ground-state energy per spin for the triangular antiferromagnetic lattice with Heisenberg interaction

An upper bound for the ground-state energy of an antiferromagnetic chain with next-nearest-neighbor interaction

A trial function for the ground state of the antiferromagnetic linear chain leads to an equation for an upper bound of the ground-state energy per spin. This equation is solved exactly

An exact limit for the Peierls distortion energy in an antiferromagnetic chain by means of a renormalization procedure

A renormalization procedure gives a rigorous upper bound for the ground-state energy per spin for a Peierls-distorted antiferromagnetic chain with Heisenberg interaction