This paper deals with the one-dimensional vertical propagation of linear adiabatic waves in plane atmospheres. In the literature there are various representations of the standard form of the wave equation from which different forms of the so called cut-off frequency are inferred. It is not uncommon that statements concerning the propagation behavior of waves are made which are based on the heig...

We discuss five useful equations related to high-frequency surface-wave techniques and their implications in practice. These equations are theoretical results from published literature regarding source selection, data-acquisition parameters, resolution of a dispersion curve image in the frequency-velocity domain, and the cut-off frequency of high modes. The first equation suggests Rayleigh wave...

In this note, small amplitude free vibration of a double-beam system in presence of inner layer nonlinearity is investigated. The nonlinearity is due to inner layer material and is not related to large amplitude vibration. At first, frequencies of a double-beam system with linear inner layer are studied and categorized as synchronous and asynchronous frequencies. It is revealed that the inner l...

A mathematical model is considered to investigate the behavior of horizontally polarized shear waves (SH-waves) in fluid saturated porous medium sandwiched between heterogeneous half-spaces. Heterogeneity in the upper half-space is due to linear variation of elastic parameters, whereas quadratic variation has been considered for lower half-space. The method of separation of variables and Whitta...

Aggregation kinetics are often described by the population balance (or Smoluchowski coagulation) equation. The population balance equation is a mean-field equation for an aggregation process. An upper critical dimension d, calculated for a given aggregation frequency has been used by other investigators to characterize the validity of this mean-field equation. It is shown that the upper critica...

We derive heuristically an integro-differential equation, as well as a shell model, governing the dynamics of the Lowest Landau Level equation in a high frequency regime.

− The paper presents a new version of the modified nodal method for analysis of the circuits with widely separated time scales. The key idea is to use multiple time variables, which enable signals with widely separated rates of variation to be represented efficiently. The differential algebraic equations (DAE) describing the RF-IC circuits are transformed in multitime partial differential equat...

We study how the neutron-star equation of state affects the onset of the dynamical instability in the equations of motion for inspiraling neutron-star binaries near coalescence. A combination of relativistic effects and Newtonian tidal effects cause the stars to begin their final, rapid, and dynamicallyunstable plunge to merger when the stars are still well separated and the orbital frequency i...

In this study, a set of experimental results for wave forces acting on a cylinder oscillating with dual frequency in still water are reported. The experiment was designed to mimic a cylinder slowly oscillating in regular waves, with the high-frequency oscillation representing the wave motion and the low-frequency oscillation, the slow drift motion. The inline forces acting on the cylinder were ...