Abstract Nature is never at a steady state. Natural history generated by ever-new and ever-interacting forces that produce continuous changes. At virtually all timescales, the geological record shows these changes do not cancel each other out and, thus, state utopic. However, we need of equilibrium as starting point for modelling Nature, steady-state condition widely used reference in idealisat...

The surface of a turbulent liquid is visualized as consisting of a large number of chaotic eddies or liquid elements. Assuming that surface elements of a particular age have renewal frequencies that are integral multiples of a fundamental frequency quantum, and further assuming that the renewal frequency distribution is of the Boltzmann type, performing a population balance for these elements l...

A numerical investigation of unsteady boundary layer flow with heat and mass transfer non-Newtonian fluid model, namely, Jeffrey subject, to the significance Soret Dufour effects is carried out by using local nonsimilarity method homotopy analysis method. An excellent agreement in results obtained both methods observed we establish a new mathematical approach obtain solutions unsteady-state phe...

In the context of the problem of heat conduction in one-dimensional systems, we present an analytical calculation of the instantaneous energy transfer across a tagged particle in a one-dimensional gas of equal-mass, hard-point particles. From this, we obtain a formula for the steady-state energy flux, and identify and separate the mechanical work and heat conduction contributions to it. The nat...

A theoretical procedure of measuring the resistance offered by a proton exchange membrane to proton flow through it has been outlined. The process has been modeled using simple mass transfer laws and electrical analogies. The final result showed that a second order differential equation, incorporating the membrane resistance, described the process completely. A major assumption that has been ma...

We develop a theory of laser beam generation of shift currents in non-centrosymmetric semiconductors. The currents originate when the excited electrons transfer between different bands or scatter inside these bands, and asymmetrically shift their centers of mass in elementary cells. Quantum kinetic equations for hot-carrier distributions and expressions for the induced currents are derived by n...

We study the hyperbolic system of equations of the so-called linear transport model in a true moving bed chromatography device with four ports. By using methods based on a suitable energy functional we show that all solutions approach exponentially a unique steady-state solution. Then, with the use of asymptotic analysis techniques we calculate the limit profiles of these steadystate solutions ...

This paper presents a hybrid solar desalination system consisting of a humidification dehumidification unit and single stage flashing evaporation unit. The hybrid solar desalination system was studied numerically. The heat and mass transfer and flow field is modeled theoretically in two-dimensional using finite difference scheme. For different operating and weather conditions the fresh water pr...