KwartalnikIssue 1-2 (241-242)
- Andrzej PRZYTULSKI: Performance of electromagnetic waves of a wide frequency spectrum in chosen reproductive organs
- Wolfgang MATHIS, Harry WEBER: Recent progress in the analysis and design of LC tank oscillators
- Przemysław PTAK, Krzysztof GÓRECKI, Janusz ZARĘBSKI: Investigations of the selected properties of led lamps
- Adam STECKIEWICZ, Bogusław BUTRYŁO: Homogenization of electric properties of the laminar materials with adjustable conductive periodic structure
- Konrad DUDZIAK, Krzysztof STAWICKI, Andrzej BRYKALSKI: Analysis of field dynamics using numerically obtained normalized ordinary moments
- Katarzyna CICHOŃ, Tomasz SMEKTAŁA, Andrzej BRYKALSKI: The use of additive technology in craniofacial reconstruction
- Tadeusz KACZOREK: Positive linear systems and electrical circuits with inverse state matrices
Opole University of Technology
PERFORMANCE OF ELECTROMAGNETIC WAVES OF A WIDE FREQUENCY SPECTRUM IN CHOSEN REPRODUCTIVE ORGANS
Summary. The electrical conductivity and relative permittivity of chosen reproductive organs versus frequency of electromagnetic wave penetrating these organs have been presented in the paper. They have been used for determining a dielectric loss angle tangent, which constitutes the basis for defining the kind of medium in which the wave may be propagated. The change in the wavelength, the propagation speed and the conventional depth of wave's penetration into different organs were calculated.
Wolfgang MATHIS. Harry WEBER
Leibniz Universität Hannover, Germany
RECENT PROGRESS IN THE ANALYSIS AND DESIGN OF LC TANK OSCILLATORS
Summary. In GHz wireless communication oscillators with sinusoidal current and voltages are basic sub-circuits. Already at the beginning of electronic circuits several types of oscillators with different active devices and circuit structures were developed. However, if we are restricted to integrated circuit technology for GHz applications the LC tank oscillator is an appropriate choice. In this paper a design approach is discussed in which also nonlinear specifications are included. Furthermore, a new analysis approach based on the Poincare-Andronov-Hopf theorem is discussed whereby its advantages will be illustrated by means of some examples.
Przemysław PTAK, Krzysztof GÓRECKI, Janusz ZARĘBSKI
Gdynia Maritime University
INVESTIGATIONS OF THE SELECTED PROPERTIES OF LED LAMPS
Summary. Results of experimental investigations of LED lamp power supply operation under overload conditions and impact of thermal phenomena on thermal and optical properties of LED modules installed in these lamps are presented in the paper. These results confirm that well designed cooling system makes possible considerable extension of the life-time of LED lamps and increase in the emitted luminous flux.
Adam STECKIEWICZ, Bogusław BUTRYŁO
Bialystok University of Technology
HOMOGENIZATION OF ELECTRIC PROPERTIES OF THE LAMINAR MATERIALS WITH ADJUSTABLE CONDUCTIVE PERIODIC STRUCTURE
Summary. In this paper the method of electrical properties homogenization of cellular conductive structures, constituting periodic layers of laminar materials is characterized. Complex geometries of these structures adjusted in terms of desired frequency response were homogenized using numerical calculations carried out by FEM. Resistance and inductance of the cells’ electrical circuit were estimated. Frequency response curves of investigated elements and equivalent homogeneous materials were compared. On the basis of the presented results, conclusions and restrictions on the homogenization of the electrical properties of such elements were formulated.
Konrad DUDZIAK, Krzysztof STAWICKI, Andrzej BRYKALSKI
West Pomeranian University of Technology, Szczecin
ANALISIS OF FIELD DYNAMICS USING NUMERICALLY OBTAINED NORMALIZED ORDINARY MOMENTS
Summary. The article presents possibilities of describing the dynamics of the electromagnetic field making use of ordinary normalized moments. Numerical calculations has been carried out with the help of computer software COMSOL. Calculated moments have been used for determination of transfer function parameters.
Katarzyna CICHOŃ*, Tomasz SMEKTAŁA**, Andrzej BRYKALSKI*
* West Pomeranian University of Technology, Szczecin
** Pomeranian Medical University in Szczecin
THE USE OF ADDITIVE TECHNOLOGY IN CRANIOFACIAL RECONSTRUCTION
Summary. Three-dimensional printing technology is widely used in biomedicine. This article demonstrates how to get the virtual and physical models which are used in additive technology used for facial reconstruction. The article presents prospects for the future use of 3D printing and 3D printers.
Białystok University of Technology
POSITIVE LINEAR SYSTEMS AND ELECTRICAL CIRCUITS WITH INVERSE STATE MATRICES
Summary. The positive linear systems and electrical circuits with inverse state matrices are addressed. It is shown that: 1) If the eigenvalues of asymptotically stable matrix n MA are located outside the unit circle then the eigenvalues of asymptotically stable matrix n nA 1 are positive and located inside the unit circle; 2) If the eigenvalues of asymptotically stable matrix n nA are positive and located inside the unit circle then the eigenvalues of the matrix n MA 1 are located in the left half plane outside the unit circle. A new problem concerning the discretization of positive linear systems and electrical circuits is formulated and solved.