Science and Education a New Dimension
Iss. 08. 2013.
Furman O. Cervical mucus as a biological marker of fertility
Abstract: The cervical mucus produced by cervical canal is a unique biological substance that plays a key role in re- productive function. From the quality of the mucus and the possibility of response to hormonal stimulation cervical crypts may affect the number of sperm penetrating into the cervical canal, the selection of sperm and sperm longevity. All of these elements play a vital role in the possibility of fertilization. Mucus from lumen of the cervix appears to be a morphologically heterogeneous entity. The proportion of these types and subtype depends on the phases of the menstru- al cycle. In cervical canal are areas with glandes. Cells of this glandes produced a mucus by hormones stimulations (es- trogen, progesterone and prostaglandin, noradrinalin and relaxin). The hormone estrogen stimulates the cervical crypts to produce mucus L, S, P types. Type P appear in near ovulatory period. This type has several subtypes, the structure of the approximation depends on the moment of ovulation. In the estrogen-dependent morphological types have large numbers of tubules (“swimming channels” (E.Odeblad)). Sperm penetrated into the cervix depends on these channels (prevent sperm with abnormal head shape to penetration and further do not participate in the fertilization). Progesteronе stimulates the G type of the mucus is thick and dense. Unique characteristics of the cervical mucus formed the basis for determining the cervical mucus as a biomarker of women’s reproductive health. The system for determining the qualita- tive and quantitative characteristics of the vaginal discharge has been standardized (Creighton Model FertilityCareTM System, TW Hylges). This techniques is the ability to assess the mucus cycle in the woman’s menstrual cycle and calcu- late the Mucus Cycle Score (MCS). Normally it is 9.1 – 16. We have analyzed in their study of the Mucus Cycle Score in conditions which reduce reproductive health (endometriosis, adhesive disease, luteal phase deficiency, infertility) and compared with the value of MCS in women without pathological changes. Noted decrease in the value MCS in women with adhesive process (MCS = 8.4), luteal phase deficiency (MCS = 7.5), infertility (MCS = 6.6), and endometriosis (MCS = 6.4), compared with comparison group (MCS = 9.4). What makes it possible to regard this as a marker of the women fertility.
Keywords: cervical mucus, mucus cycle, mucus cycle score, infertility, endometriosis, adhesive disease, luteal phase deficiency.
Furman O. Cervical mucus as a biological marker of fertility
Yatskiv O.M., Tarnovska A.V. Fertilizing ability of spermatozoa with abnormal morphology
Abstract: In this article an overview on the composition and ultrastructure of spermatozoa is presented, while empha- sizing sperm ultrastructural and anomalies and their effects on fertilization. A comprehensive high quality semen analy- sis is an essential first line investigation for the infertile couple. Semen quality is conventionally determined according to the number, motility and morphology of spermatozoa in an ejaculate. Of all semen parameters, sperm morphology turns out to be the best predictor of a man’s fertilizing potential A link has been established between sperm morphologi- cal characteristics and infertility by many investigators.
Yatskiv O.M., Tarnovska A.V. Fertilizing ability of spermatozoa with abnormal morphology
Pokhylenko A.P., Korolev A.V. Importance of Julida (Diplopoda) trophical and biotopical characteristics for anthropogenic impact estimation of millipede habitat in forest ecosystems of Samarskyi Forest
Abstract: Using litter and soil sampling, seven different forest ecosystems in Samarskyi Forest (Novomoskovskyi region, Dnepropetrovskaya oblast) were investigated. Among 6 millipede species revealed, Rossiulus kessleri (Lohmander, 1927) and Megaphyllum rossicum (Timotheew, 1897) predominated in all wood stands they revealed. Trophic preferences of Julida order representatives (Diplopoda) are reviewed. It is revealed millipede’s biotopical con- finedness. Interdependence between diplopod’s distribution in forestry ecosystems in Samarskyi Forest and anthropo- genic transformation of the given territories is analyzed.
Keywords: diplopoda, trophic specialty, leaf litter, forest ecosystems.
Pokhylenko A.P., Korolev A.V. Importance of Julida (Diplopoda) trophical and biotopical characteristics for anthropogenic impact estimation of millipede habitat in forest ecosystems of Samarskyi Forest
Korzh A.P., Frolov D.A. Metapopulation management problems of the pheasant hunting ex-situ
Abstract: The metapopulation model involves the disappearance of the local groups, their renewal, the emergence of new ones, as well as the related dynamics of the spatial structure of the metapopulation as a whole. Under the condi- tions of ex-situ and in-situ migrants are exchanged during introductions, catching individuals from the natural environ- ment, the disappearance and recovery of the small local groups. Thus, a man artificially creates and maintains the meta- population concerned, having some functional elements in natural and artificial conditions. Therefore, artificially gener- ated hunting pheasant population in the wild is a metapopulation. As birds due to the introduction into the natural envi- ronment influence in the subsequent on the properties of metapopulation pheasant hunting in general, there is a need to control this process. Pheasant hunting is considered to be challenging enough for the cultivation, so relevant is the as- sessment of its metapopulation in ex-situ. D. L. Hallett, W.R. Edwards, G. V. Burger have proposed a model of popula- tion management in pheasant hunting lands. For a natural population model displays an annual cycle of pheasant, and the mechanisms of influence of environmental factors on its life processes. The balance between exotic species and nat- ural population size allows us to generalize the findings, analysis of which shows the criticality of the model. In our opinion, the mentioned model has some shortcomings, in particular, does not take into account the conversion of land as a result of human activity, which significantly affects the efficiency of the reproduction of birds. It is also crucial to the effectiveness of the process is the introduction of exotic species and the quality of the scheme of issuance. This raises the problem of developing such a control circuit condition metapopulation hunting pheasant in ex-situ. We have devel- oped a heuristic model of state management of the metapopulation hunting pheasant in ex-situ on the basis of an as- sessment of his condition in some farms of the south-east of Ukraine. It consists of four interrelated parts: two produc- tive, one supervisory and one manager. The proposed model can effectively adjust some elements of the production process, eliminating limiting exposure. The basis for its functioning is the quality of hatching eggs, which are indicators of the general population. The action of the model was tested in a hunting club “Skif” of Kherson region in 2010 – 2012 period. During three years of the research in this sector farming the quality of hatching eggs and the efficiency of the production process as a whole have been significantly increased.
Keywords: metapopulation, pheasant hunting, management, egg, limiting the impact.
Korzh A.P., Frolov D.A. Metapopulation management problems of the pheasant hunting ex-situ
Bigaliev A.B., Zhanburshin E.T., Bigalieva R.K., Ryskulov A.R., Bildebaeva R.M., Rakhmanov G., Kozhakhmetova A. Social-economic development of Kazakhstan in present and scientific basic of ecological safety
Abstract: Man-made ecosystem disturbance represent a serious threat to sustainable development in the Republic of Kazakhstan. The paper presents an analysis of the problems of the current state of biodiversity, conservation of biologi- cal and mineral resources, environmental security and sustainable development of the environmental crisis zones in the area of the Caspian Sea.
Keywords: biodiversity, sustainable development, environmental security, the region of the Caspian Sea
Bigaliev A.B., Zhanburshin E.T., Bigalieva R.K., Ryskulov A.R., Bildebaeva R.M., Rakhmanov G., Kozhakhmetova A. Social-economic development of Kazakhstan in present and scientific basic of ecological safety
Kirienko S. Functional role of mammal as factor influence on the respiration of soil
Abstract: Functional role of mammal as factor influence on the respiration of soil Soil “breathing” – an integral compo- nent of simultaneous passage of soil processes, where the decisive role is played by biological factors. Soil excretion of CO2 is an extremely important life process, not only in edafotop, but also in the whole ecosystem, determining with other components its main function – biological productivity. As a result it displays the complexity of biological pro- cesses aimed to soil formation. Mammals excretory and burrowing activities are an important link of functional role of animals, especially on the processes of soil formation and soil biological activity. Under the influence of excretory and burrowing activity of different groups of mammals is shown one-way effect on soil processes and accelerate the cycling of matter that allows more intensive use of organic and mineral resources of ecosystem. Soil is intensively enriched with nutrients, processes of decomposition of organic substances are accelerated, the physicochemical characteristics of the soils are optimized, increasing their overall biological activity. Excretions of all mammal species that have been studied increase the efficiency of breathing. In this case, it depends on the duration of the study in the set experiment. The maximum values of soil respiration reported with exposure in 3 months. The most significant increase of this index recorded under the excretion of elk (Alces alces). In general, the growth of soil “breathing” in biogeocenosis is rised by the excretion of the most massive omnivorous species like wild boar ordinary (Sus scrofa) and such phytophages as deer (Capreolus capreolus) and hare (Lepus europaeus). The smallest changes are registered under the action of excre- tion of predator – marten (Martes martes). The influence of micromammalias on such an integral index as soil excretion of carbon dioxide is determined by such tendencies: – the effectiveness of the influence with aging of the soil destruct the animal with burrowing activities is reduced; – renewal of the soil “breathing” is increasingly happening in the areas of pollution with 1 MPC and 5 MPC, and is significantly reduced when the soil is polluted with heavy metals (Cd, Pb, Zn and Ni) 10 MPC; – Comparing with the intensity of soil respiration in areas that are not disturbed by the animal with burrowing activities, and with areas where of the soil destruct the animal with burrowing activities was marked a signif- icant positive impact of burrow activity of mole-rat is noted.
Keyword: functional role, mammal, respiration of soil, excretory.
Kirienko S. Functional role of mammal as factor influence on the respiration of soil
Kuryanova S.A. Yurasov S.M. Disadvantages of national classifications as groundwater water supply
Abstract: The article presents a critical analysis of water quality assessment by different methods on the example of the Danube River at Vilkove town. It is shown that the drawbacks of the existing methods do not make it possible to ade- quately characterize the state of water bodies as household water sources; and that the integral and average unit indices of DSTU 4808:2007 cannot be used bor classification of the sources of centralized water supply. The means for elimi- nation of these drawbacks are suggested.
Keywords: qualityassessment, household water, the source of centralized water supply, the quality indicator, unit of indices.
Kuryanova S.A. Yurasov S.M. Disadvantages of national classifications as groundwater water supply
Bernát N. Exploration and presentation of pollution sources of Sernye
Abstract: naturally occurring processes play an important role in people’s lives. We know that the relationship with na- ture can affect state of our environment in a negative and positive way. In this research I studied and measured the de- gree of pollution in my native village Sernye. During the research I visited places which could be sources of pollution, talked to local residents about possible sources, checked potential sources of pollution, and conducted various meas- urements of water pollution. In the village everyone loves to preserve the purity of his own yard. However, my work is extended to the purity of nature throughout the village, so I had to face and realize the sad fact that the seemingly clear environment is actually strongly polluted. Because of the lack of services the villagers throw away waste from their yards to the edge of the village. In this way they have a detrimental effect on the aesthetic details of the village, and pol- lute the environment. In large areas, you can see a huge variety of different types of waste. The next major source of pollution was the lack of a central sewage drainage system in the courts, as well as in areas of agricultural and farmer activity. I conducted water tests for nitrate and salt to give more accurate information about the quality of water. It turned out that the drinking water has very high levels of nitrates and salts, which is a consequence of infiltration of drinking water by sewage from households and agriculture. According to the results of my work there are two major sources of pollution: sewage water and domestic waste.
Keywords: environment, pollution, water quality, waste
Bernát N. Exploration and presentation of pollution sources of Sernye
Kazimir I.I., Solodky V.D., Bespalko R.I. Implementation of principles of steady development in the conditions of mountain ecosystems of Ukrainian Carpathians
Abstract: The thesis deals with scientific, methodological and organizational principles development of optimization use the Bukovyna Carpathians biotic resources by means of sustainable development standards implementation in terms of the Carpathian Convention Implementation Strategy. Cause-and-effect relations of biological diversity anthropogenic transformation and natural resources potential of the Bukovyna Carpathians have been determined. The highest danger to natural development of Chernivtsi Region territories and adjacent areas of Ukraine, Moldova and Rumania is caused by floods in Dnister, Prut and Siret river basins. The floods are consequences of natural peculiarities of the region as well as of forest damage of high mountain zone. Development of landscape and biotic diversity is also endangered by forestry, agriculture, tourism, recreation activities and indirect natural resources use performed not in compliance with the legal norms. Taxonomic structure of flora and fauna has been researched; protection level of rare species of vascular plants and animals of the Bukovyna Carpathians listed in the Red Book of Endangered Species of Ukraine, in the Euro- pean Red List and in Supplements to the Bern Convention has been evaluated. Special attention has been paid to condi- tion of the forests, its biological diversity and ecological role for water accumulation landscapes as well as to implemen- tation of ecological standards in the field of forestry, nature reserve fund development and ecological network. The fol- lowing has been developed for application of principles and terms of the Carpathian Convention Implementation Strate- gy: 1) methodology of the activity (scientific, methodological, legal norms base as well as resource and organization support have been defined); 2) complex programme “The Bukovyna Carpathians” consisting of goal-oriented action plans in the field of different economy branches and environmental protection; 3) areas, stages, algorithms, impedi- ments, legal and institutional limits of task fulfilment; 4) procedures of social activity parties cooperation based on prin- ciples of integrated management and division according to water accumulation areas and basins. The following princi- pal schemes have been proposed: monitoring and management improvement of ecological risks in the Bukovyna Carpa- thians by means of transparent inter-regional cooperation of the offices competent in the field of natural resources use and environmental protection; the main areas of ecological risks management system improvement in the region in terms of the Carpathian Convention Principals have been determined. It has been proved that implementation of the proposals developed in this thesis will create favourable conditions for organization and maintenance of balanced natu- ral resources use and development system in the Ukrainian Carpathians.
Keywords: the Carpathian Convention, anthropogenic and natural dangers, ecological system approach, biological diversity preservation, network.
Kazimir I.I., Solodky V.D., Bespalko R.I. Implementation of principles of steady development in the conditions of mountain ecosystems of Ukrainian Carpathians
Brem V.V. Saturation of melted flux with water vapor and hydrogen
Abstract: For the selection of the optimum flux compositions that are used for remelting of steel, a series of tests on the saturation of water vapor and hydrogen of industrial liquid fluxes that are in chemical equilibrium with the gas mixture (H2O+HF) were made. As a result, it was concluded that the fusible in an industrial environment electroslag fluxes have considerable inhomogeneity. Evidently, this inhomogeneity was not persisted while remelting samples of small volume during their saturation with gases at temperatures up to 1700°C on the developed pilot plants. The latter fact may be due either to the presence of delamination in such oxide-fluoride liquid systems, or with some kind of phase transformations during their cooling doing solidified flux, even in the conditions of its instant glass is extremely heterogeneous. A series of experiments were made to saturate a number of melted flux with water vapor in the condition of contact with the equilibrium gas phase (H2O+HF). The hydrogen content in the samples o0f fluxes ANF–1, ANF–6, ANF–29, ANF–291 and “Bisra” was found to be several tens cm3/100g of flux. With greater or lesser clarity the solubility of hydrogen tends to decrease with the increasing of the temperature for the first 50…100°C from the minimum possible for the liquid state. The theoretical estimate of the temperature dependence of the solubility of hydrogen in the molten flux, that are in contact with the equilibrium gas phase (H2O+HF), was implemented. The estimated equation for the proportion of H+ ion (x1) obtained earlier for the fluoride-oxide systems only in a general way was used, basing on the ionic theory of so- lutions with an arbitrary number of cations and anions. After substituting of the obtained values of the x1 and finding the constants of the equation has been found with the temperature increasing on 100°C maximum decrease of values of CH should occur for flux ANF–6, where it reaches 20%, the least changes CH (5÷7%) should occur for the flux “Bisra” and are assumed such for the flux AN–291 and ANF–29. A series of experiments on the saturation of the number of melted flux in a reducing atmosphere of pure hydrogen were made. It is established that values of CH have also the order of several tens of flux cm3/100 g of flux and in a known degree correlates with the points, obtained in the process of satu- ration of the same melt with water vapor.
Keywords: saturation, water, hydrogen, flux, melt, gas phase.
Brem V.V. Saturation of melted flux with water vapor and hydrogen
Dmitrenko I. V. The permeability of hydrogen in the fluoride-oxide melts
Abstract: The analysis of all set of information in the considered area suggests that the permeability of hydrogen in the flux melts, which are used for remelting, is relatively high. The result is that an open process of melting does not pro- vide the necessary protection of remelted metal from hydrogen. We carried out firstly a systematic investigation of hy- drogen permeability of the most widely used in industry standard electroslag remelting fluxes, and then considering the results, was initiated the attempt to find new flux compositions which provide effective protection against hydrogen in remelted steels. The development of new flux compositions was based on the widely used in metallurgy components: CaF2, CaO, MgO, Al2O3 and SiO2. In order to reduce the permeability of hydrogen and sensitivity to flocs of remelted structural steels was investigated the efficiency of introduction to them optimal additives of fluorides, chlorides and ox- ides of some hydride-forming elements (Ca, Li, and Ce). The methodology of the research heats remained the standard. When remelting steel 08Х18Н10Т, it was found that for a given grade of steel quantity QН, depending on the basicity of flux, changes according to the extreme law with a maximum QН at the basicity within 1,5…1,7. Regarding the elec- troslag remelting of steel 08Х18Н10Т were researched hydrogen-protective properties of some research fluxes selected primarily on the basis of systems CaO – SiO2 and CaF2 – CaO – SiO2. It is shown that to ensure satisfactory hydrogen-protective properties of fluoride-oxide fluxes reducing in them CaF2 content below 25% is inappropriate. Were found two original flux compositions that reduce the value QН compared to the best standard fluxes. For the structural steels 40ХН, 15Х3НМФ quantity QН are identified in the conditions of their remelting, using both standard and research fluxes, drawn up on the basis of system CaF2 – CaO – Al2O3 – SiO2 with the addition to them of a variety of combinations of fluoride, chloride and oxide compounds compared to the widespread strong hydride-forming elements (Li, Ce and Y). Found that for selected steels hydrogen-protective properties of standard fluxes are unsatisfactory (values QН are within 1,95 … 3,46). Found that optimal compounds of major flux components and a hydride-forming elements additivie compounds which are introduced into them, can reduce Q Н values to values significantly below 1,5. From the re- ceived materials, some research fluxes are recommended for practical use in electroslag remelting processes of studied structural steels.
Keywords: hydrogen, flux, melt, remelting, composition, steel.
Dmitrenko I. V. The permeability of hydrogen in the fluoride-oxide melts
Mitsa V., Borkach E., Lovas G., Holomb R., Rosola I., Rudyko G., Gule E., Fekeshgazi I. The visible photoluminescence from aged and freshly fractured surfacees of chalcogenide glasess
Abstract: The position of PL maximum at E1=2.43 in PL spectrum of freshly fractured g-As2S3 is in good agreement with early found “hot luminescence” g-As2S3 and illumination of elemental sulfur species on the surface of the ZnS nanobelts in this region. PL radiation from long term aged fractured surfaces of GeS2-based chalcogenide glasses was assigned to the surface contaminant effect from native oxidized layer, which might have formed in the air. When have been used for PL measuring the freshly fractured surface of g-GeS2(T3V2) all PL peaks which was connected with GeOx species where disappeared in PL spectrum.
Keywords: visible photoluminescence, chalcogenide glass, oxide phase, edge absorption, glassy GeS2
Mitsa V., Borkach E., Lovas G., Holomb R., Rosola I., Rudyko G., Gule E., Fekeshgazi I. The visible photoluminescence from aged and freshly fractured surfacees of chalcogenide glasess
Demesh Sh.Sh., Borkach E.I., Kovtunenko V.S. Determination of the analytical expressions of interatomic interaction potentials for AsnSm crystals with density functional method
Abstract: To investigate real systems, which consist of a few hundred or thousands of atoms, molecular dynamics, Monte Carlo and other computer simulation methods have great perspectives. Their application requires the knowledge of the exact potential of many-body interatomic interaction in the investigated materials. Besides the huge variety of an- alytical expressions for such kinds of potentials, their realistic parameters have found for a few types of concrete mate- rials. We have made such kinds of investigations for the materials of As-S systems with quantum-mechanical model- ling, using DFT method. For the analysis we have chosen 7 different crystal phases from these systems. For the crystals we have calculated the dependence of the energies Е(х) from the level of deformation according to crystallographic ax- es, using the software package Quantum Espresso PWSCF. In the next step we have calculated the parameters of the analytical expressions of potentials for two-body (VM) and three-body (VEH) interactions. The fitting procedures of the parameters were performed such way, that the calculated potentials were be able to approximate accurately the energy- dependence of the 7 chosen crystals from their deformation levels. The analysis of the calculations shows, that the De parameter of the potential is very close to the experimental dissociation energy, which is 2.6 eV, and the parameter r0 also only to 0.02 nm lower than equilibrium interatomic distance between As and S atoms, which is about 0.215– 0.225 nm. For the most infrequent As-As covalent bond type the r0 parameter in fact is the same as the experimental equilibrium interatomic distance between neighbour arsenic atoms, which is about 0.245–0.255 nm. But the value of De=0.85 eV more than two times lower than As-As binding energy (2.05 eV). Such kind of differences could be expli- cable that in the investigated crystals for the As-As interaction the De parameter shows generalized interaction between a great concentration of arsenic atoms. This hypothesis can be verified with the fact that for the interaction of sulphur atoms, all of that connected through “bridge-type” atoms of arsenic, the De parameter has still greater difference from the experimental value (0.47 eV and 2.8 eV, accordingly), while the value of r0 is closer to the equilibrium distance be- tween sulphur atoms in second neighborhood (0.32 nm). The calculated parameters of three-body potentials verify the above mentioned regularities of interatomic interactions in the crystals of As-S systems. Finally, the generalized param- eters of potentials have been approximated accurately with the binding energies, interatomic distances and angles for in- teraction pairs and triplets of atoms As-S, As-As, As-S-As, As-As-As, but badly correlate with local energetical and structural parameters of pairs and triplets S-S, S-S-S, S-As-S.
Keywords: interatomic interaction potentials, density functional method, As-S system
Demesh Sh.Sh., Borkach E.I., Kovtunenko V.S. Determination of the analytical expressions of interatomic interaction potentials for AsnSm crystals with density functional method
Sorokina M.M. Critical ....-closed n -multiply ... -special formations of finite groups
Abstract: Theory of classes of finite groups is one of the rapidly developing sections of the modern algebra. Formations hold the central place in this theory, i.e. classes of groups closed under homomorphic images and subdirect products. Fundamental results of formations of finite groups are set out in the book «Formations of Finite Groups» of L.A. Shemetkov and in the book «The algebra of formations» of A.N. Skiba. In the study of formations of finite groups over the past decades much attention was paid to the local formations introduced in consideration by W. Gaschutz in 1963. The notion of local formation is a functional approach. Let P be the set of all prime numbers, f – a mapping of the set P into the set of all formations of finite groups.
Sorokina M.M. Critical -closed n -multiply -special formations of finite groups
Shvachych G.G., Konovalenkov V.S., Tkach M.A. Model-based parallel construction of a numerical-analytical scheme
Abstract: The aim of this work is to construct a numerical-analytical method of designing efficient algorithms for solu- tion of tasks having the parabolic type. Using a priori information about the smoothness of solutions, great attention is paid to the construction of solutions of high -order accuracy.
Keywords: numerical-analytical method, parabolic type, solutions of high-order accuracy.
Shvachych G.G., Konovalenkov V.S., Tkach M.A. Model-based parallel construction of a numerical-analytical scheme
Cheiliakh A.P., Kutsomelya Yu.Yu., Fedun V.I., Ryabikina M.A. The structure and properties of steel 40 Kh after pulsed plasma processing using titanium electrodes
Abstract: The results of studies on the structure of samples of steel 40Kh (40Cr) after pulse-plasma treatment (PPT)under different conditions, with the use of a titanium electrode are presented in this work. Influence of plasma pro- cessing parameters on the thickness, quality and resulting microhardness of the layers are considered. With the help of mathematical modeling analysis the characteristics of wear resistance was carried. In an environment of air and high temperature of plasma is a diffusion cathode titanium alloy particles deep into the substrate and its alloying. The struc- ture and properties of the modified layer is dependent on the number of pulses of plasma treatment and inputted into the discharge energy (within the limits of 3 to 12 kJ). The discharge time was ~ 1 ms. With increasing number of pulses of the PPT density and the layer thickness increases. The results of microscopic examination of cross-sections of coatings indicate that the minimum thickness is 0.014 mm (with 2 pulses and energy of 4.6 kJ). Under the influence of a power- ful pulsed plasma exposure (4 pulses and energy of 12 kJ) on the surface of 40Kh (40Cr) steel, a layer depth of 0.076 mm formed. Usually, to improve the quality of the layer and change the structure of coatings the second pass the plasma is used. PPT with 4 and 6 pulses has a significant influence on the microstructure of the steel of the modified layer. Fur- thermore, a layer with pores and microcracks in the further processing becomes more uniform (at 6 times the pro- cessing). Carbon in an amount of 0.37% in the base metal microstructure determines formation of the modified layer, presumably from martensite (solid solution Ti in the α-Fe) to the martensite-nitride that can improve the wear resistance relative steel. The maximum values of microhardness after PPT with titanium electrode – 10510 MPa were after condi- tion with 6 pulses and energy of 12 kJ. Using the X-ray diffraction analysis to study the nature of the structural and physical processes has shown that in the modified layer observed: Osbornite (TiN) and titanium nitride (TiN), marten- site and beta Tioxide (TiO2). Application PPT coating of titanium produces multiphase coatings which have good adhe- sion to the substrate and high mechanical properties.
Keywords: pulse-plasma treatment, structural steel, the modified layer, phase composition, coating properties, wear resistance
Cheiliakh A.P., Kutsomelya Yu.Yu., Fedun V.I., Ryabikina M.A. The structure and properties of steel 40 Kh after pulsed plasma processing using titanium electrodes
Tkachenko F.K., Ryabikina M.A., Tkachenko N.V. The influence of parameters of isothermal treatment on structure and properties of steel X70
Abstract: At different cooling rates of the steel X70 a typical structure is formed. This structure consists of the polygo- nal ferrite and acicular bainite. Martensitic transformation, in contrast, occupies a narrow range of cooling rates and runs almost instantly. It can be assumed that because of the high values of the Ms and Mf temperatures in the steel tem- pering processes of the acicular structure (formed upon cooling) should be observed. We have investigated the effect of different heating temperatures and parameters of isothermal holding at temperatures of martensitic transformation on the characteristics of the resulting structures and hardness of steel X70. For this purpose samples of X70 steel were heated to temperatures of 900-1200 °C and then put under isothermal holding in the salt at 300-450 °C temperatures for 1, 5 and 10 minutes. The results showed that the coarsening of austenite grain structure is influenced by the heating temperature, the grain growth in steel X70 with Ti (0.02 wt-%), Nb (0.06 wt-%) and V(0.05 wt-%) was already ob- served at 1100 °C. Decreasing the quenching temperature increased the hardness of specimens due to production of martensite + carbides structure. Detailed microstructural examinations found out that with increasing difference be- tween heating temperature and the temperature of isothermal holding and the cooling rate of the steel X70 following types of structures can be formed: (pearlite + polygonal ferrite) → (ferrite + granular bainite) → (ferrite + acicular bain- ite) → acicular martensite. By increasing the holding temperature of 300 to 450 °С the diffusion processes and decom- position of bainite – martensite structure (formed during cooling) are accelerated. This leads to a monotonic decrease in hardness steel X70. Analogically the increasing isothermal holding time also causes a decrease in hardness.
Keywords: martensitic transformation, bainite, isothermal holding, autotempering, structure formation.
Tkachenko F.K., Ryabikina M.A., Tkachenko N.V. The influence of parameters of isothermal treatment on structure and properties of steel X70
Cheiliakh A.P., Karavaieva N.E. Influence of heat treatment on the structure, metastable austenite and wear resistance of carburized steels 12H2N4MA and 18H2N4MA
Abstract: The results of experimental research of the influence the temperature of hardening and tempering after carbu- rizing and quenching on the structure, hardness and wear resistance of steels 12Х2Н4МА and 18Х2Н4МА presented. The optimal technological regimes that improve wear resistance of steel 2,5-3 times were determined. It is shown that to improve the wear resistance of carburized steels subsequent heat treatment should be directed at getting to the surface layer of a metastable austenitic-martensitic-carbide structure in which the metastable retained austenite is capable of de- formation induced martensite transformation at wear.
Keywords: carburizing, quenching, metastable residual austenite, wear resistance, hardness.
Cheiliakh A.P., Karavaieva N.E. Influence of heat treatment on the structure, metastable austenite and wear resistance of carburized steels 12H2N4MA and 18H2N4MA
Govorun A.G., Selskiy M.P., Kutsyi P.V. Determination of RTV energy losses under transient movement modes
Abstract: This article deals with the analysis and studying of the two main hypotheses of energy loss by a wheeled vehicle under conditions of transient driving modes. According to one of them, the main reason for the loss of energy by a wheeled vehicle on the move is under conditions of transient modes is considered the decrease of an indicator of efficiency of the engine that is caused by changes in its thermal state (thermal inertia). According to another hypothesis, it is believed that the energy loss and increased fuel consumption by RTV engines is caused by changes in friction in the links of the transmission mechanisms as well as energy losses in them aimed at damping (resistance) of the torsional vibrations. Evaluating the traction-speed characteristics of the vehicle, it is accepted that the center of gravity of an RTV makes a plane motion, copying the longitudinal profile of the surface on which the RTV is moving, without fluctuations, that are caused by its irregularities. Is made precise the mathematical model of the motion of the RTV with the above mentioned equation of the traction balance, which takes into account the vibrational motion of the RTV that is caused by surface irregularities or changes in the moment of resistance movement. To obtain a complete picture of the distribution of potential energy that is caused by the combustion of fuel in the engine and converting it into kinetic energy (translational, rotational and vibrational) motion of the RTV must should be taken into account the motor damping moment (the moment of resistance fluctuations). Herein are presented the field tests of MTZ-80 with trailer PTS-4 with a load Q = 3,5 t. On the basis of these tests, according to the method of calculation of damping rate . As a result of field research of the MTZ-80 tractor, it was determined that when the tractor moves over the measured section of the field with the constant speed and the fixed position of the throttle lever (to eliminate the subjective factor of influence of the results of the experiment), with a dual-mode governor, fuel loss of 15.7 ± 4% is less than with an all- mode governor. The amplitude of the oscillations of FPHP rack, namely the torque of the engine is reduced by 2.5 times. It was also determined an increase of the damping factor, in accordance with the proposed method, which takes into account the energy loss in the engine when an RTV is moving under conditions of transient loads with different types of governors.
Keywords: diesel, system of automated regulation of diesel engine crankshaft rotation, fuel pump of high pressure, the amplitude of the fuel pump rail oscillations, damping factor.
Govorun A.G., Selskiy M.P., Kutsyi P.V. Determination of RTV energy losses under transient movement modes
Volkov V.P., Komov P.B., Komov A.B., Komov E.A., Komov A.P. Analysis of factors influence of providing technical reliability of vehicles on the road transport safety
Abstract: The reasons of traffic accidents number growth in automobile transport because of the negative technical state of the vehicles are given.
Keywords: Technical condition, serviceability, safety, culture exploitation, technical inspection, the system of tech- nical operation, the intelligent transportation system.
Volkov V.P., Komov P.B., Komov A.B., Komov E.A., Komov A.P. Analysis of factors influence of providing technical reliability of vehicles on the road transport safety
Vinogradov S.A., Konsurov N.O., Hritsyna I.N. Liquid high-speed jets as a mechanism destruction of elements building construction during rescue operations
Abstract: To rescue people in accidents, usually necessary to make breaches in the walls or overlapping’s. It needs to use rescue tool. Modern requirements for it are such that the rescue tool needed to create the breaches should provide enough productivity, be compact, portable, work as possible without vibration and ensure a minimum of dust. Prefera- bly, such tool should be non-sparking. The main modern building materials – concrete, reinforced concrete and brick. Any of these materials is much better resists compression than tension. However, the alternation in structures compres- sion and extension stresses above the limit values in creating the breaches and these things increasing productivity of tool. To realize alternating tensions in design is possible using impulse liquid high-speed jets. When liquid high-speed jet exposed on a concrete slab, a dynamic funnel formed on its surface – destruction due to compression. Loosening zone formed by the active formation of cracks in the concrete under alternating loads. The majority of particulate mate- rial carried from the zone using tailpiece of jet. In some cases, the formation of spalling zone is possible. The presence this zone is typically for concrete structures and will lead that the construction may break at a lower energy costs. The analysis of the theoretical results show that for breaking concrete walls up to 0.5 m thick fluid charge 100-150 g weight is necessary to ensure the jet velocity at the contact with a barrier about 1000 m/s. To provide such speeds appropriate to use hydrocannon. The principal feature of hydrocannon is getting pulse jets, which dynamic pressure is much higher than the static pressure in the barrel installation. Setting for holding rescue operations should have some autonomy, and these requirements are met by hydrocannon with gunpowder drive. To compensate for the impact with the creation of firearms adhere to the ratio at which the mass of firearms 100 times heavier than the charge. With this ratio, the weight of the installation should be 20-25 kg. The installation of such weight applies to portable and shall not exceed two per- sons. Thus, the creation of portable devices pulse destruction of building structures liquid is possible and promising di- rection of development of emergency rescue tools.
Keywords: rescue operations, rescue tool, destruction, liquid high-speed jet, hydrocannon.
Vinogradov S.A., Konsurov N.O., Hritsyna I.N. Liquid high-speed jets as a mechanism destruction of elements building construction during rescue operations
Lipovoy V. A. A solution of the heat transfer problem occurring at blasting cleaning of the petroleum product residuum in the tanks
Abstract: The paper deals with the numerical solution of the heat transfer problem occurring at blasting cleaning of the petroleum product residuum in the tanks by the heated technical cleaning compositions, that allows to define the param- eters highly explosive cleaning process. Cleaning of tanks from the petroleum product residuum is highly repetitive technological operation, so safety and operation efficiency of the Ukrainian tank farm are strongly depends on the pecu- liarities of this cleaning procedure. Cleaning of tanks of oil residues usually performed manually or mechanically. There are no methodologies for the fire and explosion safety assessment at these processes. The chemico-mechanical methods of tank cleaning are more effective due to the complex combined physical, chemical, thermal and mechanical effects, which are influenced on residues of petroleum products under the action of cleaning fluid. An intensification of the pro- cesses of evaporation of petroleum products residuum into the free volume of the tank is realised at the chemico- mechanical method of cleaning. These process additionally amplifying due to the heating by the hot cleaning liquid. The thermal impact jet of the cleaning liquid leads to increasing of the concentration of explosive vapours inside the tank. Fire and explosion hazard is directly relates to the level of petroleum products vapour saturation in the tank vol- ume. Thus, a quantify assessment of the process of the vapour saturation in the space of the tank is an important practi- cal problem. The process of thermal heating in the tank during the cleaning are described by the equations of thermal process which are taken place in cleaning liquid together with petroleum products residuum, equations of thermal con- vection in gases inside the tank volume (petroleum steam and air mixture) and also of the heat exchange between tank body with environment. As a result, the system of differential equations describing thermal parameters of mixture of pe- troleum products residuum with cleaning liquid as a processes in time. Solution of these equations has given a relation between the temperature of mixture on the duration of the heating process. Thus, it is possible to determine the period of time, which will needs for petroleum products residuum being heated to a predetermined value of temperature and al- so a process of temperature changing in the petroleum products residuum at this time. The resulting numerical values of the parameters have given a possibility to predict risk level of the cleaning work and to develop effective arrangements for the prevention of emergency situations.
Keywords: highly explosive, heat exchange, the concentration of petroleum products vapour.
Lipovoy V. A. A solution of the heat transfer problem occurring at blasting cleaning of the petroleum product residuum in the tanks
Lagutin V. L. The distinctive features of the second-stage suspension of propelled trolley for transportation of the dangerous goods
Abstract: The paper deals with the possibility of nonlinear spring suspension usage to provide a high level of move- ment smoothing at the transportation of dangerous goods. A specialized vehicle with a nonlinear spring suspension is developed. The vehicle has the features that satisfy the conditions of safe transportation of dangerous and especially dangerously explosive goods from the place of detection to the point of utilization. In addition developed specialized vehicle is propelled trolley, so it has not an engine and transmission that makes it design simple, reliable and inexpen- sive. The main feature of the design scheme of specialized vehicle is a presence of additional level of cushioning, with the nonlinear characteristic, which has quasi-zero stiffness in the equilibrium position. This peculiarity makes it differ- ent from the classical trolley with traditional single-stage automotive spring suspension. The additional second stage has a corrector of stiffness, so dynamic characteristics of proposed trolley are provide good enough conditions for safe transportation of dangerous goods. A preparation for transportation of dangerous goods sometimes is very difficult in the conditions of real practice due to some features of this design. The proposed design of specialized trolley has opti- mum vibro-isolated characteristics when corrector’s springs are in horizontal position, which could be realized only on the fixed level of load. The situation is typical for non-linear suspensions, but makes some problems in the stage of preparation for the transport of hazardous goods. Such problem could be solved by the improvement of the design. We propose three variant of the design of the second stage spring suspension to solve this problem:
– to put a control devices at the reference points of the corrector spring stiffness;
– the usage in the second-stage suspension single-crimping air-legs at the reference points of the loading platform;
– the usage in the second-stage suspension air-legs, which consists of double-crimping rubber shells and the valve that adjusts the height of loading platform.
Each of the proposed design of the second stage suspension of the specialized trolley for the transportation of hazard goods has its own advantages and disadvantages. The choice of the design of the second stage suspension and it rational characteristics requires a corresponding theoretical and experimental investigations. The usage of the proposed design of trolley with the improved second stage suspension as specialized vehicle for the transportation of the dangerous goods is promising for upgrading of the safety of transportation.
Keywords: highly explosive goods, the second stage suspension, correctors of stiffness, rubber-shell.
Lagutin V. L. The distinctive features of the second-stage suspension of propelled trolley for transportation of the dangerous goods
Larin O.M., Larin O.O., Chygrin V. V. A diagnosis of the technical state of the supports of fire pump by the spectra of its vibrations
Abstract: Fire pump of the emergency vehicle is an important element that provides the functionality of this specialized car. Among the main requirements for the fire pump is the requirement of its reliability. Fire pump life-time is set by the manufacturer company at the design stage and on the basis of statistics. However, for each particular pump its life-time, of course, determined by a large number of operational factors. Thus, depending on the operating conditions fire pumps could more intensively used up its life time. In this case, an important actual scientific task will be a problem of for- mation of reasonable recommendations on the procedures for assessing of the technical state of the elements of fire pump in service. Common fire pumps are centrifugal, i.e. a fire-extinguishing liquid is pushed out by the working bod- ies, which have a rotation motion with high angular velocity. This circumstance makes the car fire pumps highly dy- namic system, so pumps have a high level of vibrations. It should be noted that the performance decrement of pump re- sults in magnification of the level of vibrations. This could be effectively used as a criterion of assessment of technical condition, i.e. the parameters of pump vibration could be used for the purpose of diagnosis of the current technical state and predict the residual life-time. This study presents an analysis of the results of experimental investigations of pump vibration which has weakened supports of the pump with the holding frame. Here, physically modelled different situa- tions with varying of the level of weakness. The studies were carried out on a pump that was installed on specialized vehicles. Experiments were carried out on the base of a measurement system “Ultra-V-I», which has been developed at the Department of the dynamics and strength of machines of the National Technical University “Kharkiv Polytechnic Institute” (Kharkov, Ukraine). The measuring system consists of: vibration acceleration sensor, which is equipped with a MEMS sensor, analogue-to-digital converter and a portable computer. “Ultra-V-I» has a valid certificate of state met- rological certification and allows to make a measurement of vibration acceleration at the point of investigated object on two directions. Analysis of the experimental data shows that a substantial increasing in the vibrations at the frequency range (350-400) Hz can be considered as a criteria of reduced bolted support of the pump.
Keywords: fire pump, vibration monitoring, weakened of bolting supports.
Larin O.M., Larin O.O., Chygrin V. V. A diagnosis of the technical state of the supports of fire pump by the spectra of its vibrations
Savytskyi A. Determination of reinforced concrete bending structures strength by test load
Summary: in this article method of determining the strength of reinforced concrete bending structures by test load, in which by the expense of features performing basic operations it is possible to determine strength of bending reinforced concrete structures without destroying them during the test, is proposed. Also, described its approbation on experi- mental samples.
Keywords: test load, strength, reinforced concrete bending structure, stress-strain state indicators, deformation model calculation.
Savytskyi A. Determination of reinforced concrete bending structures strength by test load
Gutarevich Y.F., Gritsuk I.V., Dobrovolskiy A.S., Adrov D.S., Verbovsky V.S., Krasnokutskaya Z.I. Analysis of the survey results fuel economy and environmental performance of the gas internal combustion en- gine equipped with a pre-heating system in the process of starting and warm-up
Abstract: The paper presents the results of a study of gas engine preheating the internal combustion, which includes a system of accelerated warming and heat recovery system heat storage in the device during warm to ambient temperature to “hot start” and the possibility of loading. A study on the mathematical model of the system engine preheating the in- ternal combustion at different temperature environments. Studies have confirmed the reduction of fuel consumption by warming the engine of internal of combustion, reduced emissions and reduce warm-up time before the possibility load- ing of internal combustion engine, equipped with a heating system plugs.
Keywords: heat the battery, the system pre-start warm-up, warm-up time, waste heat of the exhaust gases.
Gutarevich Y.F., Gritsuk I.V., Dobrovolskiy A.S., Adrov D.S., Verbovsky V.S., Krasnokutskaya Z.I. Analysis of the survey results fuel economy and environmental performance of the gas internal combustion en- gine equipped with a pre-heating system in the process of starting and warm-up
Nenov A. Approaches to the Identification and Classification of Factors Influencing the Dependability of Telecommunica- tions Network
Abstract: The article gives a detailed analysis of the problem of classification of factors determining the reliability of generalized telecommunications network, shows the importance of the classification in the task of reliability analysis and in the construction of an integrated system reliability analysis, highlights the major approaches to the implementa- tion of the dependability factors classification. The types of problems encountered in the analysis of the telecommunica- tion networks reliability. Variants classification of the factors determine the reliability of the network, on the basis of the following classifications: stage of the life cycle of the telecommunications network, the naturalness of the impact, the localization of the source of exposure relative to the boundaries of the system, the corresponding component relia- bility, the extent of the impact of laws, the nature of the objects of the telecommunications network, the localization of sources of exposure in relation to conditions of functioning of the telecommunications network, are described. The advantages, disadvantages, construction peculiarities of the corresponding classifiers are specified. For individual cases the examples of border placement factors in the overall classification scheme are shown. The presentation of material il- lustrates by generalized flowchart. A variant of the specific identification and classification of factors suitable for use in the implementation of the collection and processing of information about telecommunication network failures is pro- posed. It presents three major categories of factors affecting dependability: equipment failures, software errors, and hu- man errors. In addition, the classification of the source data that are appropriate to base of the reliability analysis of the telecommunication networks, and destabilizing factors relevant these data with brief description are proposed. In this classification there were eight categories of data: a) the internal structure of the communication center; b) the character- istics of the software used host, subsystem or all network; c) the methods and characteristics of the communication channels; d) the nature of the formation and transmission of network traffic; e) modes and conditions of operation of the network; f) information about the relative importance of sites in the network; g) the characteristics of the network maintenance and repair organization; h) the characteristics of staff for the network.
Keywords: dependability; communication network; factors influenced on dependability; classification; method of dependability estimation.
Nenov A. Approaches to the Identification and Classification of Factors Influencing the Dependability of Telecommunica- tions Network
Polshchykov K.O. General models of neuro-fuzzy systems control the intensity of data flows in a mobile radio network
Abstract: General models of neuro-fuzzy systems control the intensity of data flows in a mobile radio network. In the article the general models of neuro-fuzzy systems control the intensity of data flows in a mobile radio network are pro- posed. Advantages of mobile radio networks to facilitate their use in the interest of the military forces are listed. Expe- diency of neuro-fuzzy control of the intensity data flows to improve the efficiency of information delivery in the mobile radio network is founded. To perform the functions of the neuro-fuzzy control traffic at the proposed generic models of hybrid intelligent systems based on the use of neural networks and fuzzy inference algorithms Sugeno 0th and 1st order. The structure of these models is determined by the functionality of the layers of artificial neurons, and is adapted to per- form the procedures of fuzzy inference (fuzzification, aggregation, activation, and defuzzification). It is concluded that the presented model can be used for the synthesis of neuro-fuzzy systems for controlling the intensity of sending the da- ta source nodes, the intensity of retransmissions and packet drops in the intensity of transit nodes in a mobile radio net- work.
Keywords: neuro-fuzzy systems, mobile radio network, the intensity of the data flows, model, control.
Polshchykov K.O. General models of neuro-fuzzy systems control the intensity of data flows in a mobile radio network
Manokha L., Limanska N. Management by work of equipment of bakery production by construction of optimal chart of preventive-maintenance repairs
Abstract: The modern equipment of bakery enterprise has high enough reliability indexes. But in the process of exploi- tation the state of equipment constantly is under the action of different factors, modes and terms of work. It reduces his operating reliability and increases probability of origin of refuses. Reliability of equipment depends not only on the quality making and correct exploitation but also from the scientifically-reasonable chart of technical service and timely repair. The system of preventive-maintenance repairs envisages totality of organizational and technical events on a care, service and repair of equipment, conducted prophylactic, on beforehand worked out a plan with the purpose of preven- tion of unexpected exit of equipment from a line-up and maintenance of him in permanent operating readiness. All works on service and repair of equipment are subdivided into: TBO service, periodic prophylactic operations and плановые repairs An equipment looks around periodically according to a chart and is the important stage of prophylac- tic events. Reviews are conducted between плановыми repairs and combine with the change of the worn out details and light maintenance without that an equipment can not be exploited to next планового repair. An equipment examines a repair personnel during technological dwells equipment or in non-working time. The built chart of preventive- maintenance repairs allows to promote efficiency and reliability of work of productive equipment. And it will result in reduction of outages of production and charges of material resources and will provide implementation of working charts. Thus the use of the system of preventive-maintenance repairs for a bakery enterprise will provide continuous work of productive equipment and trouble-free process of making of products.
Keywords: optimization, chart of workovers, preventive-maintenance repairs, bakery production.
Manokha L., Limanska N. Management by work of equipment of bakery production by construction of optimal chart of preventive-maintenance repairs
Gryshchenko І.V. Survivability of infocommunication networks through the use of intelligent systems
Abstract: Survivability of communication networks after causing damage to the network and is a problem of Infocom- munications. This paper explores the creation of intellectual systems, the persistence of which can be protected from damage and suppression, protection against unintentional all kinds of interference, as well as a number of organizational and technical measures, that provides fast restoration of the functioning of the infocommunication network.
Keywords: network, survivability, infocommunications, intelligent system.
Gryshchenko І.V. Survivability of infocommunication networks through the use of intelligent systems
Shvachych G.G., Kholod E.G. Object oriented model for distributed database engineering in conditions of fuzzy sets
Abstract: The proposed work considers object oriented model of the system that provides solution for enterprise plan- ning and reporting task complex in conditions of fuzzy sets based on symmetric pairs of cryptographic keys. Object identifiers (cryptographic keys) describing the enterprise structure are generated automatically based on full (standard- ized) names of structural units. To generate the keys CRC32 one-way hash function (NIST standard) is used making possible creation of 232 no repetitive keys. The population of cryptographic keys is the title of the problem being solved. The problem solution is made by relations processor described with macrofunctions. Relations processor represents a server module providing both single and batch problem processing. From the standpoint of relations processor all tasks are concurrent. Thus the key feature of the developed system lies in the fact that tasks may be connected to the system when they are necessary. In this connection each task is described by CDS linear information table (binary representa- tion of XML format) providing compact files of non-kernel data base. Flexible description of the enterprise structure permits concurrent change of data in all tasks being solved by the system. In contrast to traditional relational data bases the object oriented model makes possible effective solving for a complex of automatic transaction tasks such as inher- itance of past period design parameters in the parameters of new period, inheritance of previously described structures, removal and addition of new structures subject to interactive description to the new period detailed design, automatic information posting for the required time period, etc. The system model is powered by the latest SET-oriented (non- kernel) technology and grid computing (MIDAS). Unified task standardization and accepted open architecture make possible unlimited system developing depending on informational needs and performing parallel tasks by independent architects in the state-of-art Delphi and С++Builder environment.
Keywords: data bases, fuzzy sets, cryptographic keys, relations processor, server module, kernel-free technology, grid computing, transactions.
Shvachych G.G., Kholod E.G. Object oriented model for distributed database engineering in conditions of fuzzy sets
Cherednichenko O., Yanholenko O. Towards Web-Based Monitoring Framework for Performance Measurement in Higher Education
Abstract: The given work represents web-based monitoring framework for measuring performance of functioning of higher education establishment. High-level key performance measures for higher education are suggested. The models forming the basis for web-based monitoring framework and their goals are presented. Multi-agent architecture is sug- gested for implementation of the framework.
Keywords: Performance measurement, higher education, web-based monitoring, information retrieval
Cherednichenko O., Yanholenko O. Towards Web-Based Monitoring Framework for Performance Measurement in Higher Education
Kniasieva N., Kalchenko A. Estimation of the quality of communication services in terms of customer satisfaction
Abstract: The article is devoted to the modern methodologies for identification of QoS. Three models for definition the QoS criterias relevant to the users are considered. The example of QoS assessment for multimedia service is given.
Keywords: Next generation networks , quality of services.
Kniasieva N., Kalchenko A. Estimation of the quality of communication services in terms of customer satisfaction
