Transient Response of a Laminated Composite Plate

Propagation of guided waves in a laminated plate is of interest for ultrasonic nondestructive evaluation of defects and for material characterization. There is a need for a thorough understanding of the wave propagation characteristics in such a plate in order to use ultrasonic means to determine the material properties, assess damage, and characterize defects. The problem is also of interest for study of acoustic emission

Irreversible matter creation in inflationary cosmology

Irreversible matter creation is investigated in a two-component (scalar field and ordinary matter) cosmological fluid in a homogeneous spatially flat and isotropic Friedmann-Robertson-Walker (FRW) inflationary Universe during its reheating era. The thermodynamics of open systems as applied together with the gravitational field equations to the two-component cosmological fluid leads to a generalisation of the elementary reheating theory in which the decay (creation) pressures are explicitly considered as parts of the fluid stress-energy tensor. Particular models describing coherently oscillating scalar waves and leading to a high particle production at the beginning of the oscillatory period are considered too.link_to_subscribed_fulltex