We studied the cooperative phenomena induced by injection of coherent phonons by THz optical pulses. Based on the analogy to the photoinduced phase transitions observed in various materials, we consider that cooperative interactions between electrons and coherent phonons will lead to the multiplication of excited electrons and/or growth of a transient phase, which is understood by bifurcation o...

The paper brings a new mathematical model for analysis of circuits containing periodically operated switches. The model uses the Laplace and modified Z transform (mixed p-z approach).This approach enables us to determine the steady-state and transient components of the load current in relatively simple and lucid form. The solution is a closed-form and is not dependent on the number of the pulse...

Phenomena associated with the turbulent flow of molten steel in a continuous casting mold are responsible for many defects in the final product, including surface slivers, frozen meniscus hooks, captured inclusions that enter the mold from upstream, and mold slag entrapment. Animations of some of these transient flow phenomena are presented from Large-Eddy Simulations of a typical slab caster w...

The solid/fluid interface appears in many ultrasonic measurement systems. Models for the system must take account of the interface. Analytical models for wave phenomena at the interface (especially curved interfaces) are either difficult or subject to severe approximation. The finite element method is ideal for this especially when the problem domain is bounded. A survey of this subject has bee...

Urban centers present all over the world striking similarities which translate into universal laws describing their growth and morphology. In this paper, we study a simple 2-dimensional cellular automata model containing what we identify as essential ingredients in the demographic change. The slow addition of population to an initially empty area (mimicking migration) added with a reaction-diiu...

Measurements of the global pressure field created by shock wave diffraction have been captured optically using a porous pressure-sensitive paint. The pressure field created by a diffracting shock wave shows large increases and decreases in pressure and can be reasonably accurately captured using CFD. The substrate, a thin-layer chromatography (TLC) plate, has been dipped in a luminophore soluti...

Transient dynamics are of large interest in many areas of science. Here, a generalization of basin stability (BS) is presented: constrained basin stability (CBS) that is sensitive to various different types of transients arising from finite size perturbations. CBS is applied to the paradigmatic Lorenz system for uncovering nonlinear precursory phenomena of a boundary crisis bifurcation. Further...