Bulletin of Prydniprovs'ka State Academy of Civil Engeneering and Architecture

4-10

Authors: O. N. Pshinko, V. V. Pristinskaya

Problem definition. On the Railways of Ukraine is very large number of slab tracks operated with cracks, which leads to significant reduction of term of their service. The main causes of defects are unsatisfactory operation of the way and insufficient physical–mechanical characteristics of concrete and low quality raw materials. It is therefore necessary to develop the optimum structure of concrete for manufacturing these concrete products. Purpose: to identify the main defects slab tracks on the Railways of Ukraine and give reasons for their possible development. Put the results of implementation of the planned experiment and to provide recommendations for improving the technology of manufacturing these concrete products. Analysis of recent research: a lot of scientific works of the previous years it is dedicated to the improvement of the design of slab tracks. But very little attention is paid to quality of materials, improving the technology of manufacturing of these structures. Results: to develop optimal composition of concrete was conducted planned experiment using quality materials that meet all the requirements of normative documents. As a result it was established that to increase the strength necessary introduction of chemical additives in the structure of concrete that allows reducing water-cement ratio and reducing consumption of cement. It also has a positive effect on the structure of a cement stone, which leads to increased strength, frost resistance and water resistance of concrete. Conclusion. On the basis of the received results it is necessary to conduct the second of the planned experiment. This will allow more carefully choose such a composition of the concrete mixture that will meet all the requirements and have very high physical–mechanical characteristics. But the task should be approached very carefully, because most of the existing defects in structures of slab tracks appear because of infringement of technology of their manufacture.

18-27

Authors: A. S. Shipilov

Problem statement. Significant difficulties appeared while the attempts to use the concept and the model of three-dimensional space for solution of the problems, for example, in mechanics of deformed anisotropic bodies, in physics for development of the theory of elementary particles and single theory of field. It is expected that new ideas will appear in the mentioned sciences with opening real dimensionality of anisotropic environment spaces. Dimensionality of space is the number of independent dimensions characterizing the environment. Analysis of publications. Nowadays there are two approaches to the explanation of the space. The basis of the first one is on Democrit’s idea used by Newton where vacuum is referred as the special kind of objective reality. The second approach of understanding the space comes from Aristotle and Leibnitz. They consider geometrical characteristics of the material objects and properties of their environments [3]. A number of scientists stick to the combined version of the views on the space. According to M. I. Duplischev [1, page 28], «SPACE together with MATTER is the primary substance of the NATURE… and everywhere has its material content… is the endless reservoir of discrete matter of any forms and structural creations» [1, page 32]. Pramatter filling the space is ether. Ether particles are absolutely elastic small balls moving chaotically in the vacuum. [1, page 28] O. Yulanov [6] thinks that the ether of physical vacuum is torsional (twisted, vortical) electromagnetic field, energy carriers that create the particles of the substance. F. Engels [2] stated that through any point it is possible to draw three mutually perpendicular lines that means 2 vectors of the opposite direction. That is why vacuum is 6-dimensional. Nowadays it is supposed that the space is 3-dimensional. To discover independent spatial directions in the environment, which resist to deformations of stretching and pressing in different ways, there were taken the following postulates: 1) two opposite vectors of different signs on one line acting by turns are independent and create 2–dimensional space; 2) two perpendicular vectors of the same or different signs acting simultaneously are independent and the space in case of different vector signs is divided by the bisector of the angle between them on two nonuniform spaces; 3) on the plane four perpendicular vectors coming from the same origin of coordinates pairwise positive and negative but not having turns of the signs, acting by turns in pairs, create two 2–dimensional independent spaces divided by the bisector on the positive and negative direction of the vectors; 4) two opposite differently signed 3–dimensional bases combined by the the same origin of coordinates, deviatoric plane and perpendicular hydrostatic axis divided on the negative and positive directions create 6–dimensional basis. Conclusion. These postulates combined with the turns of 6–dimensional basis around its hydrostatic axis on the angles multiple of 90°, made it possible to come to the conclusion: dimensionality of the space of fully anisotropic environment is 24. Geometric model of such space represents a set of 8 three-dimensional rectangular coordinate systems consisting of 4 bases of positive and 4 bases of negative direction of the axis of coordinates coupled by common deviatoric plane and hydrostatic axes, lying at the same line divided by the starting point of the coordinate in two opposite directions, wherein systems in pairs as a whole are turned around hydrostatic angle of 90°, 180°, 270° relatively to one basis taken as a source. There were given the examples of using open space in application to development of different-module theory of elasticity and for determination of the criteria of limiting state of anisotropic bodies while its tension.

37-43

Authors: F. O. Korsun

Problem. Investigations of mine air conditioning systems situated in deep mines of Donbas by electric model were performed. Hydraulic impact values depending on the hydrosystems completion method were illustrated in the pictures. Literature review. No scientific research has been done in the field of hydraulic impacts in vertical pipelines before. D. K. Smirnov and L. B. Zubov were engaged with the problem of hydraulic impact in Ostankino television tower, Moscow. However, they had to stop the pump, whereas therein HI with flow overlapping is described. In case the pump is stopped, the first amplitude goes down (discharging, pressure reduction), whereas in case the flow is lapped with the valve — the first amplitude – pressure increase takes place and the first harmonic goes up. Aim. Investigation of HI depending on the hydrosystem completion method and in the vertical pipeline. The following variants of the pipeline have been considered: 1. According to the type of pump protection: a) The pump is protected with the damper; b) The pump is protected with a return valve. 2. According to the pipeline design: a) The pipeline location is asymmetrical comparing to the valve; b) The pipeline location is asymmetrical comparing to the valve. 3. According to the use of kinetic energy of fluid during pipeline closure: a) Fluid energy is dissipated in the pipeline; b) Fluid energy is partially absorbed by the working load acting simultaneously with the hydraulic distributor. Its value corresponds to the pipeline parameters. For the mentioned variants, Picture 1 shows strain oscillograms in the perturbation pit of the ransitional process GN.-8, corresponding to the pipeline section prior to the valve. This implies that the presence of matched load enables to reduce the amplitude of the first pressure wave by 1,4 times. At the same time, maximum pressure surge for both symmetrical and non-symmetrical pipeline with any type of pump protection is around 2,0 MPs (n* = 200 m). This value is relatively large. This variant corresponds to the non-symmetrical pipeline (relative to the perturbation pit); the pump is protected by the damper τ3 / Тн = 1. That is why there was an idea to perform the control object in such a way that it did not miss a direct current level but would let the alternating component (in kind it should not let the fluid in but it would let the pressure wave in, thus quenching oscillations. In the model it can be applied with the help of large capacity condenser which would be parallel to the electronic key. In kind it is performed with the help of the damper, parallel to the valve whose principal scheme is fully similar to the damper scheme that is parallel to the pump. The present variant was performed with the help of the model. Strain oscillograms in the perturbation pit of the transitional processes GN-8 and GN-9 are given in рicture 3. After their close examination it can be clearly observed that stain oscillations in these sections are fully eliminated. The same is true for all pits of the model. The present variant corresponds to the symmetrical pipeline (relative to the perturbation pit); the pump is protected with damper; τ3 / Тн = 1. Consequently, working with hydraulic distributor with the damper parallel to it the pressure down the entire pipeline passes from one steady-state value to the other one smoothly, without jumps (h* = 0). At the same time no special protection of the pump is needed, the design of units that protect it from accidental pressure jumps can be simpler, the possibility of cavitation is eliminated; impact energy is transformed into potential energy of deformed damper materials, and can at least partially return to the system with the opening of the valve. Conclusion. 1. The application or Racc for a non-symmetrical model in a strict branch leads to the decrease of stress amplitude in the first harmonic component by 42 % during the first one-half period, by 57% during the second one-half period, further harmonic components are even more decreased. In the reverse branch such decrease is 31 % and 49 % respectively (curves 1, 2, рic. 1, 2) 2. The application or Racc for a symmetrical model leads to the decrease of stress amplitude in the first harmonic component by 41 % during the first one-half period, by 81 % during the second one–half period of a strict branch. In the reverse branch such decrease is 40 % and 77 % respectively (curves 3, 4, 5, рic. 3, 4, 5). 3. The time of transitional process in a non-symmetrical model with the presence of Racc is decreased by 2,6 times. 4. The time of the main transitional period in a symmetrical model is decreased by 6,8 times. Thus, according to both parameters symmetrical model is a more favorable one. A satisfactory explanation is that there is a progressive wave, transferring energy brought by branches into Racc load. Similarly, in the pipeline, a progressive wave supplying energy of the halted liquid in the pipeline into effective load. Without Racc during interruption of the circuit in the model (like in full-scale hydraulic system) stationary waves are initiated whose energy is used for traction. With the application of the proposed hydraulic distributor and cold bearer distribution system in the system of mine air conditioning, heat economy will be approximately 30–40 %. With the application of the proposed hydraulic distributor in the system of mine air conditioning, technical effect lies in the elimination of hydraulic impacts, mine air conditioning system becomes more simplified and reliable.

50-58

Authors: V. Uzhelovs'kyy, S. Tkachenko

Problem statement. The efficiency of bioconversion processes is largely determined by the level of automation and process control biogas, which allows to optimize the process, enhance its efficiency and the ability to adapt to the real operating conditions. Analyzing of the resent research. In studies of contemporary experts in the field of process management energy production from unconventional sources has had a steady and good understanding of the management of biogas production from biomass. In particular, are interesting publications of Yulia Orlova, B.Baader, V. Serbin, H.Ratushnyak, J. Lione. According to them, for the implementation of the bioconversion process, ensuring its quality at the stage of direct fermentation substrate, it is necessary to form at least six data flows: raw fermentation time, temperature, stability, temperature, gas concentration, load reactor (digesters), the quality of mixing. Using known experimental dependence quantitative yield of biogas supported temperatures, and using extreme control, you can optimize the system for automatic process control biogas in the loop temperature control.There are two approaches to the task of governance Research objective. Improving quantitative yield of biogas by fermentation substrate in the reactor (digesters) by maintaining the optimum temperature. Conclusions. 1. Developed a simulation model of control extreme temperature conditions in the fermentation substrate digesters buildable and provides increased reliability compliance implementation process. 2. Resulting simulation model can be recommended, at the design stage, prior to setting up the parameters of the extreme regulator for the desired transition process with a given accuracy. 3. Application of extreme regulation , can improve the performance of digesters by 10 %.

64-71

Authors: L. Chernova, Yu. Shelest, O. Ivannikova

Object of research — residents of Dnepropetrovsk of all social groups aged 16 and older. Subject of research — images of urban environment and their perception by residents and experts (students of architectural department). Urgency of the research issue is determined by the fact that the image of the city and urban environment designed and made by architects not always coincide with the city image created in residents’ awareness, which can act back on the environment and has a great effect on the process of its formation, structuring, usage and estimation. Problem statement. According to modern sociology, the urban space is a communicative space. Scanning and understanding of the image that is put by designers and architects, its distortion and change during residents’ life in the process of their interaction with architectural and physical city environment shows that images in planning and architectural ensembles don’t coincide in residents’ vision and usage. City is the text that is written, rewritten, read and estimated differently. Intensive development and growth of cities make their image perception and orientation in them difficult. Contradictory urban space generates the same ambiguous estimations, impressions, emotions and feelings. This can make difficult the residents’ identification with the city as it requires complete image. According to M. Yakovleva the clearer the idea about the object identification is, the easier the correlation of the individual with the object will be. Сonclusion. City image can be determined as a combination of emotional and rational ideas about the city in group and individual awareness. This combination is based on communication and interaction with the environment, in the process of its perception. 1. In the course of the research it was identified the city image change in residents’ awareness as a result of transfer from industrial to postindustrial society when old images (city-plant) are replaced by new ones, but complete new image is not still found as well as the ways of further development and specialization of Dnepropetrovsk are not determined. 2. Our research proved the fact that people who live in the similar conditions begin estimate their living space similarly. The resident of one city area gave similar images of their microdistrict and the city centre. 3. Architecture not only embodies social space with its structure, value systems and social inequality but also influence on new generations and changes society. Social differentiation determines spectrum of preferences and impressions on the city and indicates disadvantages of city space. 4. Architectural environment has an influence on the residents forming their taste, habits, behavior models, space images and culture of relations. 5. Architectural environment creates a certain combination of messages in people’s perception which is comprehended as text in the context created by architects, planners, customers and which is read and rewritten by residents in daily practice. 6. Architectural environment eventually changes its images and needs constant support and development. At construction and reconstruction of a certain architectural environment its residents’ views, images and wishes should be taken into account. That will allow to get rid of subjectivism of designers and researches and understand the living world and problems of city agents’ relations.