The structure of homogeneous turbulent shear flow is studied using data generated by Direct Numerical Simulations (DNS) and a linear analysis for both compressible and incompressible cases. At large values of the mean shear rate, the Rapid Distortion Theory (RDT) limit is approached. Analytical solutions are found for the inviscid compressible RDT equations at long times. The RDT equations are ...

A new three-dimensional temperature-dependent viscoelastic constitutive model for unidirectional fiber reinforced, polymer composite materials subjected to small strains is developed in this work. The key point introduce the behavior only where appropriate, based on of underlying constituents: particular, matrix deviatoric response considered viscoelastic, while its volumetric response, as well...

The number of local optima is an important characteristic of a landscape. It appears to depend on the pair-correlation of the landscape as well as on its deviations from statistical isotropy. We use Tanaka and Edward's XY Hamiltonian as an example for an investigation of the relationships between ruggedness, metastable states, and isotropy.

The Landau theory' of continuous phase transitions provides a powerful tool for understanding transitions between solid phases whose symmetries have a group-subgroup relationship. In the Landau theory, the thermodynamic free energy F of the crystal is written as a function of an order parameter Q. In the high-symmetry phase, the minimum of F is at Q = 0. In the low-symmetry phase, the minimum o...

A system has been developed for determining precisely the dilatational and shearwave group velocities in rock samples subjected to hydrostatic confining and internal pore pressures independently to 10,000 psi. Pulses of polarized shear waves of SO@kc/sec carrier frequency are produced and detected by axially polarized ceramic transducers attached to Pyrex glass prisms mounted in pressure-sealed...

Pulmonary injuries are a major source of morbidity and mortality associated with trauma. Trauma includes injuries associated with accidents and falls as well as blast injuries caused by explosives. The prevalence and mortality of these injuries has made research of pulmonary injury a major priority. Lungs have a complex structure, with multiple types of tissues necessary to allow successful res...

We discuss the problem of the stability of the isotropy of the universe in the space of ever-expanding spatially homogeneous universes with a compact spatial topology. The anisotropic modes which prevent isotropy being asymptotically stable in Bianchi-type V IIh universes with non-compact topologies are excluded by topological compactness. Bianchi type V and type V IIh universes with compact to...

Let F be an arbitrary field (of arbitrary characteristic). Let A be a central simple F -algebra endowed with a quadratic pair σ (if charF 6= 2 then σ is simply an orthogonal involution on A). We show that the Witt index of σ over the function field of the Severi-Brauer variety of A is divisible by the Schur index of the algebra A.