Abstracts of papers for

Previous issue vol. 41, no. 4 (2000)

vol. 42, no. 1 (2001)

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Journal of Technical Physics - vol. 42, no. 1 (2001)
is the issue dedicated to Professor Czesław Rymarz
on the occasion of his 70th birthday.

Contents of issue 1, vol. 42

1. L. Solarz: Seventieth anniversary of Professor Czesław Rymarz

   Original Contributions

2. E. Włodarczyk: The closed form solution of the Darboux boundary value problem for backward driving of solids by the high explosive
3. Cz. Rymarz: Differential geometry in modeling the microstructural material media
4. D. Rogula, M. Sztyren: Dynamics of flux lines in strongly anisotropic superconductors
5. W.A. Trzciński, S. Cudziło: Determination of metal acceleration abilities and detonation energy of explosives from cylinder test
6. S. Kozak: Numerical analysis of phenomena in superconducting OGMS separator
7. J. Cabański: Exact method of solution of free vibrations problem for one-dimensional rheological structures

   Brief Notes

8. E. Danicki: Points of vanishing slowness curvature of quartz and lithium niobate
9. J. Zagrodziński: Resonances of the open cavity
10. J. Szczygłowski, A. Krawczyk, A. Roman, P. Kopciuszewski, M. Kużmiński, W. Wilczyński: The use of Bayesian analysis to the model of energy loss in magnetic materials

E. Włodarczyk: The closed form solution of the Darboux boundary value problem for backward driving of solids by the high explosive

The closed form solution of the Darboux boundary value problem, which occurs at the backward driving solids by the condensed explosive, was obtained in this paper. The constructed solution may be used, among other cases, for estimating the explosively driven elements velocity of the casing and liner of the wedge hollow charge. The solution may be applied for evaluation of the explosive active part in the wedge shaped charge, too. These problems will be considered in the next paper.

Contents

Cz. Rymarz: Differential geometry in modeling the microstructural material media

The paper contains considerations, which concern an application of differential geometry to construction of a compatible theory of media with microstructure. Technologies of modern materials create a need for modeling the processes and phenomena occurring in such materials. Application of the differential geometry to this end is justified, since this mathematical theory is concisely and logically formulated and exhibits a high level of generality. Therefore the physical theories constructed with application of the geometry are, as usual, very effective. In this paper, a short introduction to the differential geometry is given. Further the outline of geometrical theory of defected media is presented. Main part of the considerations has been devoted to a construction of the micropolar media in a bundle space. The bundle space is a very fruitful extension of the tangent space, because it is a Cartesian product of the classical (Euclidean) space and the microstructural fiber space.

Contents

D. Rogula, M. Sztyren: Dynamics of flux lines in strongly anisotropic superconductors

The dynamics of networks of quantized magnetic flux lines in superconductors is formulated in terms of the anisotropic string model. The paper extends the static equlibrium theory to the general time-dependent phenomena. Quasistationary kinetic processes, as well as strictly dynamical phenomena, involving the anisotropic effective inertial mass of a string segment, are considered. The dynamical aspects of the directional instability of strings are examined.

Contents

W.A. Trzciński, S. Cudziło: Determination of metal acceleration abilities and detonation energy of explosives from cylinder test

Cylinder test is performed for chosen high explosives of military interest. Impulse X-ray photography is used for recording of the process of acceleration of a copper tube by detonation products. The dependence of the Gurney energy on the volume of detonation products as well the detonation energy are established on the basis of the cylinder test results. Calculated parameters are compared with those obtained from a thermochemical code and from calorimetric measurements.

Contents

S. Kozak: Numerical analysis of phenomena in superconducting OGMS separator

This paper presents a numerical analysis of phenomenon in the superconducting OGMS separator. The OGMS separator should only deflect particles, but many of them can be captured on the inner wall of separator. Presented results of the captured material shape indicate a strong dependence on many separator parameters. The presented methods using FLUX 2D and OPERA 2D for calculation of the OMGS separator area can be adopted easily to solve other electromagnetic problems.

Contents

J. Cabański: Exact method of solution of free vibrations problem for one-dimensional rheological structures

Free vibrations of one-dimensional rheological structure have been described by the system of the conjugated partial differential equations. A vector form of this system of equations allows to identify the self-adjoint linear operators of inertia, damping and stiffness. These operators are not homothetic, hence the method of a separation of variables for the considered system of equations is applicable only in the introduced complex Hilbert space. Such a separation of variables leads to the system of ordinary differential equations in time and to the system of three ordinary differential equations with respect to spatial variables. Solution of the obtained boundary-value problems proceeds in a classical way, however, the results are of a complex conjugated type. Applying the fundamental principle of the general orthogonality of complex eigenvectors, the problem of free vibrations of the system with arbitrary initial conditions was solved in exact form.

Contents

E. Danicki: Points of vanishing slowness curvature of quartz and lithium niobate

There are points on the slowness surface of anisotropic crystals which cannot be satisfactorily described with standard Gaussian curvatures. The paper presents complete sets of such points in quartz and lithium niobate, and also certain extraordinary points in Rochelle salt. The method of their evaluation and verification is presented briefly.

Contents

J. Zagrodziński: Resonances of the open cavity

Resonant states in an open cavity, i.e. where the electromagnetic field is described by a continuous spectrum, are considered. Such a situation appears when coupling with a surrounding world is not neglected. The idea is a natural continuation of a classical potential scattering theory, but in a vector version. Formulating a scattering problem with a unitary scattering operator (for nondissipative systems and for normalized incident and reflected waves), the energy stored in a finite volume is determined by the phase y of the reflection coefficient being an eigenvalue of the scattering operator. The causality principle gives rise to the resonant states of the system as the real frequencies when the derivative of this phase with respect to the frequency - dy/dw reaches its maxima. The general statements are illustrated by some examples and, in the simplest form, the same technique was used in the past for measurements of microwave cavities.

Contents

J. Szczygłowski, A. Krawczyk, A. Roman, P. Kopciuszewski, M. Kużmiński, W. Wilczyński: The use of Bayesian analysis to the model of energy loss in magnetic materials

The paper aims at coupling energy losses in magnetic materials and their domain structure. The Bayesian analysis has been used in order to make it. The analysis has led to analytical formula for the calculation of energy losses as a function of domain width. It is a good departure point for solving an inverse problem, i.e. looking for domain structure on the basis of the data obtained from measurement of bulk parameters.

Contents