ISSN 2224-087X (Print)
ISSN 2224-0888 (Online)

Collected scientific papers
"Electronics and information technologies"

(In 1966-2010 published under the title "Electrical engineering")

(Certificate of State Registration 17618-6468 from February 11, 2011)

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Issue 1

Issue 1, Pages: 3-17
I. Bolesta
The physical backgrounds for the creation of metamaterials, i.e. artificial materials with properties not available in nature, are discussed. The conditions for the existence of simultaneously negative values of dielectric permittivity (ε ) and magnetic permeability (μ) in order to achieve of negative index of refraction (n), are also considered. It was shown, that values of ε < 0 and μ < 0 in the microwave region can be reached, respectively by using wire arrays and concentric metallic rings with gaps called as split-ring resonator. In the visible and near-infrared spectra ranges both negative magnetic permeability and dielectric permittivity can be obtained in a composite of nanowires arranged into parallel pairs. The nature of unusual properties of metamaterials, such as negative refraction and super resolution is also discussed.
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Issue 1, Pages: 18-29
Thermally stimulated and tunnel luminescence in Y2O3 and Sc2O3 ceramics (english)
O. Bordun, I. Bordun, I. Kukharskiy
Thermally stimulated luminescence (TSL) and tunnel luminescence (TL) in Y2O3, Y2O3:Eu and Sc2O3 at X-ray irradiation was investigated. The Alentsev-Fock method for separate TSL curve info elementary components with additional experimental control by method of thermally clearing was used. Based on analysis of forms of elementary bands, which formed TSL curve, was makes a conclusion that the recombination processes in TSL bands with maxima at 110, 122, 176, 185, 200 and 247 K in Y2O3 ceramics and at 121, 136, 200, 215 and 221 K in Sc2O3 ceramics was described of linear kinetics. The TSL in these ceramics connected with recombination processes in structural complex YO69- (or ScO69-). In Y2O3:Eu ceramics TSL spectra consist in the main activators bands. Account that Eu3+ ions were seek to stability half-filled 4f-shell and effective trapped of electrons, proposed, that the TSL light was caused by recombination of holes with Eu2+-centers. The energy activation and frequency factors of local traps centers, which exhibit-ed in TSL bands, were calculated with number methods. Recombination processes at va-cated local traps centers in Y2O3 and Sc2O3 ceramics was caused diffusion-controlled tun-nel recombination at the expense of thermally stimulated migration of holes, located on Vk-centre, was proposed. Exist of TL and his investigated in Y2O3 and Sc2O3 ceramics was carry out. The recombination processes were described models which observed re-combination with complex interaction, based analysis of decay kinetics was established. The TL take placed in pairs with electron components in centers, which thermally vacated at 176 K in Y2O3 ceramics and 200 K in Sc2O3 ceramics. Holes components of tunnel pairs were caused with centers, which thermally vacated at 110 and 122 K in ceramics based on Y2O3 and 121 and 146 K in Sc2O3 ceramics.
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Issue 1, Pages: 30-35
Electronic spectrum and thermopower of oxygen doped HgBa2CaCu2O6+
O. Babych, I. Gabriel, M. Vasyuk, M.Matvijiv, R. Lutsiv
The analysis of thermopower temperature dependencies at T>TC for the second member of mercury homological series of HgBa2CaCu2O6+ superconductors in the narrow band model was provided. Near Fermi level structure states density is represented in the form of asymmetric lorentzian. A transformation of the electronic spectrum parameters with the oxygen content changing has been considered. The presence of correlation between the effective width of conducting band and superconducting transition temperature TC was shown. The comparison of patterns obtained from the optimally doped samples of the neighboring members of a homologous mercury series is presented (n = 1,3).
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Issue 1, Pages: 36-43
Luminescence studies of the pure and In, Sb and Sn doped cadmium iodide crystals
S. Velgosh, . Karbovnyk, . Kityk, A.I. Popov, . Rovetskyy
Luminescence spectra (in the 1,5-3,5 V range) and luminescence excitation spectra (in the 3,5-45 V range) of pure and In, Sb and Sn doped cadmium iodide crystals have been investigated using synchrotron radiation. Origin of the luminescence bands and the influence of impurities on the radiative centers formation are discussed. Luminescence spectra features in the fundamental absorption range are analyzed considering band structure data for CdI2.
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Issue 1, Pages: 44-49
Luminescence properties of cacium-galium-germanium garnet doped with europium
L.Kostyk, O.Tsvetkova, S.Novosad
Spectral-luminescent properties of calcium-gallium-germanium garnet doped with europium in the temperature range 85 - 295 K were investigated. A comparative analysis of luminescence spectral characteristics of these materials in the form of polycrystalline ceramics and single crystals was done. Found that in ceramics in contrast to single crystals, one type of activator centre Eu3+ was formed. Shown that polycrystals Ca3Ga2Ge3O12: Eu3+ has an intense luminescence in the region of the spectrum (transitions 5D07Fj). The possibility of using them as phosphorus for white LEDs was analysed.
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Issue 1, Pages: 50-59
Some characteristics of chemical etching of monocrystal silicon surfaces
B. Pavlyk, R. Didyk, J. Shykoryak, R. Lys, D. Slobodzyan, A. Hrypa, I. Tshehil
The processes of restructuring of structural defects in the surface layer of mechanically treated surfaces of p-Si as its digestion were investigated using techniques of optical and atomic force microscopy. Massive (thickness of 4 mm.) monocrystal silicon samples were plastically deformed on the given value using the original installation. The features of distribution of dislocations in the plane (111) along the deformed samples depending on the magnitude of deformation were investigated. It is shown pictures of polishing and selective etching of surfaces (111), (110) and (112) without dislocations and deformed samples of p-Si. It is shown that places of an exit of dislocations on the surface (111) decorated with deep (about 2 microns.) dislocation pits, unlike pits with smaller depth (about 0.4 microns.) not related with linear defects of crystal lattice. The possibility of obtaining information about the angle of the exit of dislocation to the surface, or the amount of displacement of dislocations under the influence of external factors by layered method of etching the surface
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Issue 1, Pages: 60-72
Physical properties of nano-sized crystals [N(CH3)4]2Zn1-Cuxl4 (x = 0.5, 0.42, 0.25), [N(CH3)4]2Cul4, [N(CH3)4]2Mnl4
S. Sveleba, I. Karpa, I. Katerynchuk, R. Shymkiv, I. Kunyo, O. Fitsych
This paper investigates the influence of the size of crystals [N(CH3)4]2MeCl4 (Me = Zn, Mn, Cu) on temperature and phase transition temperature range of existence of incommensurate superstructure. Found that reducing the size of crystals to several periods superstructure causes fever those phase transitions Ti, Ts, and the expansion temperature range of existence of incommensurate phases.
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Issue 1, Pages: 73-79
Portative air-hydrogen fuel cells based on nanoporous silicon
I. Olenych, L. Monastyrskii, O. Aksimentyeva
It was investigated possibility of using porous silicon layers for creating ecological hydrogen microfuel cells. The operation of the microfuel cells with polypropylene protonconductive membrane is based on using hydrogen accumulated in porous silicon. The parameters of these cells were studied in the 20-1600C temperature range. It was estimated discharge capacity of microfuel cells based on porous silicon. The results determine the research directions that aim to improve the efficiency of hydrogen sources of electric current.
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Issue 1, Pages: 80-88
IR detectors on the basis of CdHgTe epitaxial layers
V. Pysarevsky, A. Shevchenko
Using the method of vapour phase epitaxy it is developed the technology of obtaining CdHgTe epitaxial layers suitable for fabrication of IR detectors. Technological aspects of forming epitaxial layers of n- and p- type of conductivity by means of annealing, doping and etching in RF plazma are considered. Peculiarities of passivation of CdHgTe surface are studied. Technology of fabrication of multielement photosensitive structures of photoconductive and photodiode types is developed. It is investigated parameters of the obtained laboratory exemplars of photoreceiving devices.
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Issue 1, Pages: 89-97
Modelling adhesion bonds in copper condensates on monocrystalline silicon (english)
V. Yuzevych, B. Koman
Using macroscopic techniques of physics of surface, theoretical research has been done regarding the changes in the energy of adhesion bonds in nanolayers at the interface between copper thin films and silicon monocrystalling substrates at different speeds of deposition. The energy of adhesion bonds and the work of adhesion turned out to be an order of magnitude larger compared with interphase energy and strain, respectively. Based on the thermodynamic approach, the method of estimating the ratio between the electric and the mechanical components of interphase energy has been elaborated.
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Issue 1, Pages: 98-109
Spatial anisotropy of photoelastic effect in quartz crystals
A. Andrushchak, O. Yurkevych, N. Andrushchak, O. Kushnir, A. Kityk
We analyze spatial anisotropy parameters for the photoelastic phenomena in crystalline quartz. Analytical expressions for the indicative surfaces of piezooptic and elastooptic coefficients and of mechanically induced optical path difference, are derived for the crystals of point symmetry group 32. Basing on literature data for the photoelastic parameters of quartz and using program packages Calc3D and View3D, along with a program supplement MSurf for the standard MatLab package, which have been developed by us, we have constructed and studied quantitatively the indicative surfaces mentioned and their stereographic projections. We have shown that a gain as large as 30 percent can be achieved for the photoelastic parameters of quartz crystals by means of passing from standard geometries of principal crystalline cuts to more general experimental geometries.
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Issue 1, Pages: 110-118
Application modified Anger algorithm for reconstruction coordinate point of interaction in thick position sensitive detector
V. Kamyshan, V. Pedash
The reconstruction of the point of interaction coordinate in thick position sensitive detector by modified Anger algorithm was investigated using computer modeling. A set of simulations with various scintillation positions was made. It was shown that usage of modified Anger Algorithm can eliminate the problem of linear image distortion related to contraction of reconstructed positions to the center of coordinates. The drawback of this method is other linear distortion that is seen as contraction of reconstructed positions to the center of PMT. This type of distortion could easily foxed using linearity correction methods.
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Issue 1, Pages: 119-125
Modeling of optical transmittance of the Fabry-Perot structure with birefringent crystal
O. Kushnir, T. Guz, O. Dzendzelyuk, Yu. Klymovych, V. Mikhailik
The aim of this work is to study optical transmittance of a Fabry-Perot structure containing a crystal with a double refraction. Using a program written in the frame of MathCad software package, we have modelled the intensity of light transmitted through such a system after having undergone multi-beam interference. The analysis is performed concerned with possible dependence of the optical transmittance on a number of parameters such as polarization azimuth of the incident light, temperature of a crystal, light wavelength, reflection coefficient of mirrors, and a double refraction magnitude.
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Issue 1, Pages: 126-133
Calculation of electrooptic coefficients for the doped TGS crystals
V. Stadnyk, Yu. Kiryk, I. Matviishyn
The temperature and spectral dependences of refractive indices ni and the quadratic electrooptic coefficients are studied for the triglicyne sulfate (TGS) crystals doped with L-valine. Decrease in the n and nz parameters (~1-3 10-3) and increase in ny (~2 10-3) are observed. The parameters of Sellmeier formula, the refraction and the electron polarizability are calculated. It is shown that doping of the TGS crystals with D-serine leads to weakening temperature dependences of ni and Δni. Qualitatively, the observed changes are due to the known increase in the mechanical and dielectric rigidity of the doped crystals, together with the corresponding decrease in the spontaneous polarization and the changes in the refraction occurring for the components of organic sublattice.
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Issue 1, Pages: 134-141
Localized modes of the gradient planar waveguides. Analogies in the quantum mechanics
V. Fitio, V. Romakh, Ya. Bobitski
Numerical method of finding propagation constants of localized modes of the symmetric planar waveguides and solution of the stationary Schrodinger equation is developed. The method is based on Fourier transform of the wave equation and as result is obtained an integral equation, in which the integral is replaced by summation. In of the final case, we obtain of linear algebra problem on the eigenvalues and eigenvectors. The method is tested on many examples.
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Issue 1, Pages: 142-148
The features of temperature dependence of dielectric constant of high-resistivity GaSe crystals within the model of distribution of effective dipoles by relaxation times
O. Fl’unt
The solutions of the differential equations written to explain the temperature behavior of dielectric spectra in the systems with distribution of the effective dipoles in wide temporal range have been calculated and analyzed. The distribution of effective dipoles corresponds to the dielectric spectra, characteristic for systems with hopping movement of electric charge carriers. According to the proposed model, the temperature dependence of dielectric constant in the range dominating by the dispersion describing by law ω-(1-n), where ω - circular frequency, 1-n ≈ 0,2, obeys the inverse Arrhenius law exp(T/T0). Inverse Arrhenius law is stipulated by thermally activated changes of relaxation times of the effective dipoles in the systems with distributed relaxation times according to the power law with small value of n. The model explains the frequency increase of T0. With increasing frequency. The experimental data measured on high-resistivity GaSe crystals confirm the predictable temperature dependences.
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Issue 1, Pages: 149-155
Correlation estimation of the pitting corrosion on the rough surface
L. Frankevych
For the investigation of the pitting and cracking formation on the metal surface we suggested to use graded ratio for rough surfaces. Preliminary mathematical modeling of the pitting formation and its growth was performed on test speckle-patterns. Calculated graded ratio allows us to reduce the error in determining the pitting location and its area when we use the method of spatial-temporal speckle correlation technique.
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Issue 1, Pages: 156-165
Electronic speckle pattern interferometry and speckle correlation for determination of surface microdisplacement fields
T. Voronyak, A. Kmet’, O. Maksymenko, L. Muravsky
Schemes of experimental setups for study of microdisplacement fields of rough surfaces are proposed. First scheme realizes the phase-shifting electronic speckle pattern interferometry technique. Second scheme combines simultaneously the phase-shifting electronic speckle pattern interferometry and digital speckle correlation techniques and enables to produce 3D surface displacement fields. Both schemes are tested during analysis of surface displacement fields of a steel beam under bending load. The procedure of spatial matching of displacement fields obtained experimentally by different techniques is considered.
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Issue 1, Pages: 166-175
The estimation of radioactive releases of Dobrotvir thermal power plant (Lviv region) and their influence on an environment
V. Grabovskyi, O. Bratash
The results of research of the impact of Dobrotvir thermal power plant (DTPP) on the radiological state of environment are presented. To use gamma-specrtometric method the radionuclide composition of coal burned on Dobrotvir TPP, slag and fly ash were investigated and the emissions of radionuclides into the atmosphere under this power station operation were estimated. There were calculated the isotope 226Ra depositions per unit area of soil within a radiuses of 2 km, 5 km and 8 km from the DTPP and radionuclide composition of soils in its vicinity were tested. The small contribution of the station releases to total maintenance of natural radionuclides in soils was marked.
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Issue 1, Pages: 176-181
Exploring the application of small neural networks in pattern recognition problems
A. Farenyuk, Z. Lubun
The framework of neural networks was originated as an attempt to get advanced in the exploration of cognitive process and artificial intelligence building while modeling the work of distinct neurons and connection between them. The solution of intelligence problems through the implementation of neural networks became significant after decades of development. Some example of such problems is pattern recognition - faces, handwriting recognition etc. Intelligence inprocess control is another application of neural networks. Our proposal is genetic algorithms as a tool to find network optimal parameters and mini-mize the network. Minimized network was implemented, based on Atmega328-PU microcontroller.
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Issue 1, Pages: 182-188
Digital regulator of excitement for the power synchronous generator (english)
Jumber Dochviri
In the work the transfer functions of synchronous generator (SG) in discrete z-transformations as well for open-loop, as closed-loop of voltage control system are obtained. Using logartithmical pseudofrequency characters are established optimal transfer functions and parametres of excitiment regulator of SG. The transient processes of the voltage of SG are simulated in MatLab.
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Issue 1, Pages: 189-198
Practical diagnostics of electronic circuits: hardware and software
B. Blagitko, V. Brygilevych, V. Rabyk
The problems of the testing and measurement that arise during the diagnostics of electronic DC circuits and in the frequency domain using multi-testing method are considered. The description of method of the measurement of real and imaginary parts of the node potentials and microprocessor system, that implement it, is given. The examples of the diagnostics of electronic circuits in frequent domains are given.
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Issue 1, Pages: 199-205
Determination the parameter of eddy-current transformer which interacting with ferromagnetic material
V. Martinov, D. Trushakov
The work contains the results of theoretical research of interaction between a laying-in U-type core eddy-current transformer (ECT) and tested ferromagnetic material. There has been developed a mathematical simplified model and received equations for engineering calculation of introduced real resistance and reactance which can used for development eddy-current defectoscopes.
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Issue 1, Pages: 206-211
Accelerated calculation of dynamic modes in weakly dissipative systems
V. Hryhorenko, I. Romaniv, Ya. Shmygelsky
We consider a method for accelerated calculation of dynamic modes for the case of weakly dissipative systems with periodic external influence. The method enables rapid tracing of transient processes and essentially reduces the process of searching for the steady state. We report the results of numeric experiment concerned with calculations of transient processes occurring in the electronic scheme of a voltage rectifier.
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Issue 1, Pages: 212-222
Hierarchical clusterization of text documents in the vector space created by semantic fields
B. Pavlyshenko
The algorithm of hierarchical clusterization of text documents in the vector space created by frequencies characteristics of semantic fields has been proposed. The effectiveness of using low dimension matrix of documents’ semantic characteristics in the algorithms of text arrays cluster analysis has been shown.
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Issue 1, Pages: 223-228
Web-interfaces for access to databases
O. Stolyarchuk, R. Shuwar, A. Prodyvus
Features and development method of unified user access interfaces to the databases from the Internet are considered. Queries, which an user can create, rational choice and optimum of managing elements and forms at creation of user interface for working with the databases using HTTP protocol are analysed. Limitations, which appear at planning of web-interface, requirements for integrity and uncontradictions of the data are also analysed.
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Issue 1, Pages: 229-240
Computer modelling of stress trajectories for investigation of tectonic processes in the Earth’s lithosphere
V. Fourman, N. Khomyak, L. Khomyak
The finite-element approach using Hermitian splines to construct stress trajectories on a rectangular grid is proposed. This algorithm generalize easy for arbitrary domains "cutting" the grid around the specified path. The conceptual algorithm for modelling of stress trajectories and slip lines within the framework of program integration (for spreadsheets, contouring, presentation) in VBA is implemented. Each of the stages can be used interactive or in batch mode. The features of the program interaction, data workflow and ways to improve performance are discussed. The robustness of the software prototype in series of problems of trusts formation is tested. Some of the results are important for the interpretation of geological processes in the Ukrainian Carpathians.
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Issue 1, Pages: 241-246
Processing of remote sensing images using BOINC platform
Y. Shyyka, R. Shuwar
The BOINC system of distributed computing and BOINC project of processing of raster images of remote sensing is described. Main principles of the work of BOINC system and approaches of adaptation of applications for use in distributed computing project. For segmentation of images of remote sensing modification of Kruskal algorithm is presented. Textural features based on moments are used for image segmentation. Efficiency of presented project is analyzed.
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Issue 1, Pages: 247-251
Using free software in Unkrainian high schools: an attempt of analysis
G. Zlobin
The use of free software in Ukrainian high schools has been analyzed on the base of FOSS Lviv 2011 Conference materials. Examples of free software using were categorized according to the following directions: distant learning, computer mathematics systems, general issues of free software implementation in education, using free database management system MySql, using package for educational purposes, using free graphic editor Gimp and using open software developing packages.
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Issue 1, Pages: 252-257
Study of the principles of logic elements in higher school
B. Tsybulyak
We have considered accomplishment of the practical laboratory work "Algebra of lo-gics and logic elements" that uses computer modelling of real microcircuit chips within the NI Multisim. A model has been suggested for practical checking of the microcircuit chip K137LE3 and determining its main characteristics.
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© Ivan Franko National University of Lviv, 2011

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