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In the temperature range ΔT ≈ 321 K ÷ 322 K, the kinetics of the nonequilibrium domain structure of triglycine sulphate crystals, both pure and with specially introduced defects, has been studied by means of piezoresponse force microscopy technique. The temporal change in the domain structure as a set of regions with a scalar order parameter of P (r, t) = +1 and −1 for oppositely polarized domains was analysed by the behaviour of the space-time correlation function C(r,t) = ·Р(r,t)Р(0,t)Ò. At different distances from the Curie point Tc, the characteristic length Lc, as a scale measure of the average domain size, increases with time according to the power law Lc(t)~(t−t0)a. A decrease of the exponent a with distance from Tc can be a consequence of the transition of the domain structure of TGS crystals from a non-conservative state to a conservative one.

The expression for time dependence of excited state dipole moment of molecule with charge transfer on the correlation function of instant spectra kinetics has been deduced on the basis of the theory of solvatochromism. Time dependence of excited state dipole moment of well known luminescence probe 6-propionyl-2-dimethylaminonaphtalene in polar solvent is presented. [ABSTRACT FROM AUTHOR]

The measurements of intensity of infrared radiation from the surface of rock sample under nonstationary change in stress state are described. The synchronized records of alterations in axial stress of sample under the uniaxial compression and the corresponding time variations in the intensity of infrared radiation from the sample surface are obtained. It is shown that identification of the parameters of elastic oscillations under the action of nonstationary load is reliable. [ABSTRACT FROM AUTHOR]

We investigate a two-dimensional network simulator that model the dynamics of drainage dominated flow where film flow can be neglected. We present a new method for simulating the temporal evolution of the pressure due to capillary and viscous forces in the displacement process. To model the dynamics, we let the local capillary pressure change as if the menisci move in and out of hour-glass shaped tubes. Furthermore, a method has been developed to allow simultaneous flow of two liquids into one tube. The model is suitable to simulate different time dependencies in two-phase drainage displacements. In this paper, we simulate the temporal evolution of the fluid pressures and analyze the time dependence of the front between the two liquids. The front width was found to be consistent with a scaling relation w ∝ tβ h(t/ts). The dynamical exponent, β, describing the front width evolution as function of time, was estimated to β = 1.0. The results are compared to experimental data of Frette and co-workers. [ABSTRACT FROM AUTHOR]