 Z.T. Kurlandzka:
Irwin criterion for dielectric with strong electrostriction
 R. Brojewski:
Structural equivalence and stability of some atmospheric air flow models
 J. Avsec and M. Marčič:
Calculation of thermophysical properties for solids
with application of statistical thermodynamics
 A. Pielorz and W. Nadolski:
Dynamic analysis of nonlinear loads on gear teeth
in discretecontinuous model of single gear transmission
 J. Warmiński:
Influence of external force on the parametric and selfexcited system
Brief Notes
 Cz. Rymarz:
Ponderomotive force in laboratory and comoving frames of
reference at the CGS and SI system of dimensional units
 J. Janucki and J. Owsik:
Solution of a problem of diffraction from a plane grating
at normal wave incidence
 J. Janucki and J. Owsik:
Diffraction from rectangularprofile gratings
 Z.T. Kurlandzka:
Irwin criterion for dielectric with strong electrostriction
 A fracture criterion, being an extension of the Irwin criterion for the case of
elastic dielectric with strong electrostriction, is derived. The paper is a
generalization of the previous paper by the author, where electromagnetic interactions
resulting from the Lorentz force according to the DixonEringen model were taken into
account. Here nonlinear electromagnetic interactions are supplemented with terms, which
include the additional material constants responsible for strong electrostriction.
Contents
 R. Brojewski:
Structural equivalence and stability of some atmospheric air flow models
 Two ways of modeling of flows in lower atmosphere forced by stationary flows in
upper layers of the atmosphere are presented in the paper. Attention is paid to
inequivalence, due to the Coriolis force, of differential models based on 3D equations
of flow of liquid and based on the flow description by means of the stream function.
Numerical difficulties of the two ways of solving the flow problem and a way of
overcoming them are presented. Structural instability of the models is proved and some of
the responsible factors are indicated. Among others are also formal parameters of the
model, e.g. the time step of integration.
Contents
 J. Avsec and M. Marčič:
Calculation of thermophysical properties for solids
with application of statistical thermodynamics
 The paper deals with a mathematical model for calculation of the thermodynamic
properties of solids. The mathematical model, based upon statistical thermodynamics, is
designed to assess the impact of atom vibration, electron excitation and the effect of
intermolecular energy between atoms in a crystal. To calculate the configuration
integral, the perturbation theory was used with the van der Waals model as perturbation.
The temperaturevariable coefficients were introduced into the model presented in this
paper. Finally, the model was compared with the experimental data proving a good
matching.
Contents
 A. Pielorz and W. Nadolski:
Dynamic analysis of nonlinear loads on gear teeth
in discretecontinuous model of single gear transmission
 In the paper, four nonlinear functions describing forces occurring between the
teeth in a single gear transmission are discussed. It is assumed that gear teeth can have
characteristics of a soft as well as of a hard type. In the study, a discretecontinuous
model consisting of two ponderable shafts torsionally deformed and four rigid bodies is
used. Considerations are performed by means of the wave method which enables to determine
nonlinear dynamic loads in steady as well as in transient states.
Contents
 J. Warmiński:
Influence of external force on the parametric and selfexcited system
 Influence of an external harmonic force on a nonlinear parametrically and
selfexcited system with two degrees of freedom has been investigated in this paper.
Vibration analysis has been carried out for coupled RayleighMathieuDuffing oscillators.
By means of the multiple scales' method, the existence and stability of periodic and
quasiperiodic solutions close to the main parametric resonances have been considered.
Influence of a small external force on vibrations in the synchronization, chaotic and
hyperchaotic region has been analyzed. Transition from regular vibrations to chaotic and
hyperchaotic motion has been presented as well.
Contents
 Cz. Rymarz:
Ponderomotive force in laboratory and comoving frames of
reference at the CGS and SI system of dimensional units
 In this paper, the influence of the system of dimensional units on the
uniqueness of the ponderomotive force has been considered. It was established that at the
CGS Gauss system, the ponderomotive force is nonunique. The nonuniqueness follows from
the socalled dimensional degeneration, what means that several values have the same
dimension. Since all the electromagnetic fields, at the CGS Gauss system, have the same
dimension, therefore any pair of them can be treated as the density of electromagnetic
momentum. In the SI system of units, due to the lower (dimensional) symmetry, the
dimensional degeneration disappears and only the pair of inductions D,
B has the proper dimension for a ponderomotive force. Therefore the CGS Gauss
system of units should not be used in the theory of combined electromechanical fields.
The forms of ponderomotive force have been formulated in the laboratory and comoving
frames of reference at the Gauss and SI systems of units. It has been also proved that
the ponderomotive force is invariant under the change of the frame of reference.
Contents
 J. Janucki and J. Owsik:
Solution of a problem of diffraction from a plane grating at normal wave incidence
 Periodic structures have been used in many applications of laser technology and
radio engineering. They replace the transducers of radiation parameters. The methods
employed for calculation of their electrodynamic properties are well known from the
literature. However, complicated numerical computations are required to solve the
diffraction equations in theirs general form. The paper presents the method of
calculation of electrodynamical properties of a plane periodic structure for the
particular case of normal wave falling. The used transformations allow to reduce the time
of numerical calculations.
Contents
 J. Janucki and J. Owsik:
Diffraction from rectangularprofile gratings
 Relations describing diffraction of E and Hpolarized electromagnetic
waves from rectangularprofile diffraction grating have been formulated. The method of
the analysis enables the calculation of diffraction efficiency of singlelayer or
multilayer gratings, in which the profile of a single period consists of an arbitrary
number of perfectly conducting mutually perpendicular surfaces. An algorithm of numerical
solution of the equations has been verified by comparing the results obtained by the
presented method and the results obtained from the exact analytical solution.
Contents
Reprints of the full papers may be obtained from their authors.
Contact Editorial Office in case you need
the address of the respective author.
