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Документ

Progress in cement science - why alkaline activation?

(KNUCA, 2014) Krivenko, P.

Fifty years ago just an idea of the presence of free alkalis in a cement matrix was considered by the ordinary portland cement (OPC) people as an absurd one and this was a basic postulate accepted in the chemistry of cements. In 1957 a scientist from Ukraine (USSR) Victor Glukhovsky put forward an assumption which was taken as a base for development and bringing into practice of construction a principally new class of cementitious materials which first appeared in the art under a name of “alkaline cements” (now also known under a general name of “alkali-activated cements (AAC)”. A validity of these ideas is confirmed by more than 50 years of evolutional development and vast experience collected from practical use of new materials in a variety of large-scale applications. A present review covers theoretical views on role played by alkali in cement stone structure formation. Examples of compositional build-up of the alkali- activated cementitious materials as a function of quantity of alkali and type of aluminosilicate component are reported as well as the results of inspection taken over the AAC concrete structures made with these cements.

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Spiral method of concretion mining from the bottom waters

(KNUCA, 2014) Sukach, M.

These features occurrence and distribution of deep-sea nodules. A development of the bottom of fossil spiral manner. Scheme is shown floating and complex trajectory carriage bottom of the unit. The basic technological calculation unit that moves around the base module and given recommendations on its use.

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Analysis of modified bitumen difference polymers

(KNUCA, 2014) Onischenko, A.; Kuzmіnets, M.; Aksenov, S.

An important step in the preparation of modified bitumen is selection of the composition and verification of various polymers’ effectiveness. Therefore, paddle mixers are widespread in both industrial and laboratory conditions for efficient mixing of bitumen with polymers. The developed method allows to determine the completion time of modification process at various process parameters (temperature, mixing speed and content of the modifier) to complete stabilization of the properties and the homogenization of bitumen. The results of studies showed that optimal time for bitumen modification at wich take place both stabilization of the properties and homogenization, ie astringent take the necessary level of uniformity with latex Butonal NS198, is about 3 hours.

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A finite element technique and results of continual fracture process modeling

(KNUCA, 2014) Bazhenov, V.; Pyskunov, S.

The techniques of modeling of continual fracture process for space circular and prismatic bodies under long-term static or cyclic force loading condition and some results of determination of responsible parts lifetime is presented in this paper. The scalar damage parameter is used to describe the material continual fracture process. A stress-strain problem solution made with semianalytic finite element method (SFEM). It‘s shown , that the value of residual lifetime could be differ significantly for different loading condition and object configuration.

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The principles of discrete modeling of rod constructions of architectural objects

(KNUCA, 2014) Kulikov, P.; Ploskiy, V.; Skochko, V.

This article describes the basic principles of rod spatial building constructions modeling by means of discrete geometry. The mathematical dependence that form the basis of this approach are the differential regularities between the geometric and physical parameters of the modeled constructions, as well as the parameters of the external loads which determine the final shape of the model.

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The risk assessment of threats from biological objects in environmental safety

(KNUCA, 2014) Kryvomaz, T.; Voloshkina, O.

Necessity to present results of scientific research in an accessible form for proper interpretation by public and environmental safety experts has been shown. Myxomycetes ecology and metabolism to verify their safety for human health has been evaluated as an example. Bayesian methods for probability analysis is proposed to be used for risk assessment. The "Environmental safety passports of species" are recommended for evaluation of impact of each species on the environment, humans and other living organisms.

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Development of Ukraine territory flooding processes; Its parameters and the influence on the environmental safety level

(KNUCA, 2014) Voloshkina, O.; Bereznitska, J.

Shows the present state of development of flooding processes of Ukraine territory. Given filtration stages in the flooding the process of and methods of their calculation. The method of filtration resistance for calculating of the filtering in flooding process is analyzed. Shows the dependence between the development of flooding process and intensifying processes of landslides on Ukraine territory.

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Protection of building materials against biodeterioration using energy saving nanotechnology

(KNUCA, 2014) Zhuravska, N.

The advances in energy-efficient nanotechnologies in construction has been considered. The harmful effects of building materials, the impact of pollution in violation of indoor climate on human activity have been analyzed. The author has proposed a hypothesis that has been confirmed for using the method of concrete protection from biological damage.

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Optimization of motion regimes for machines and mechanisms with a mehatronics control

(KNUCA, 2014) Lovejkin, V.; Chovnyuk, Y.; Romasevich, Y

Motion control of machines and mechanisms with a mechatronics control is now recognized as a key technology in mechatronics. The robustness of such motion control will be represented as a function of stiffness and a basic for practical realization, for example, in the precise agriculture. Target of such motion is parameterized by control stiffness which could be variable according to the task reference. However the system robustness of motion always requires very high stiffness in the controller. The paper shows that control of acceleration realizes specified motion simultaneously with keeping the robustness very high. The acceleration is a bridge to connect such robustness and variable stiffness. For practical applications, a technique to estimate disturbance is introduced to make motion controller to be an acceleration controller of machine/mechanism. Optimization of motion control of flexible structure and identification of mechanical parameters are also described.

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Calculation of deflection of one- and two-layer slabs supported on four sides

(KNUCA, 2014) Smorkalov, D.

Presented method and results of experimental research of deflection of one-layer and two-layer slabs influenced by short-term lateral load. Proposed method of calculation based on the limit equilibrium method, calculation of slab deflections values by LIRA-CAD bundled software. The comparison of experimental and theoretical results of the calculation of deflections slabs.

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Modeling of crack growth process in spatial bodies under cyclic loading condition

(KNUCA, 2014) Bazhenov, V.; Pyskunov, S.; Shkryl, O.

The algorithm for finite element modeling of fatigue cracks growth in the spatial bodies under cyclic loading using semianalytic finite element method (SFEM) is presented. The crack growth process is described by Paris' equation, stress intensity factor (SIF) is determined by the direct method. Testing of the algorithm is executed on the problem of the development of an elliptical crack in a prismatic body under the action of cyclic loading.

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Application of generalized "method of lines", for solving problems of thermoelasticity of thick plates

(KNUCA, 2014) Chybiryakov, V.; Stankevich, A.; Levkivskiy, D.; Melnychuk, V.

In this paper, a new combined method of reducing dimensions of spatial thermoelasticity problems was proposed; based on the “method of lines”, combined with Bubnov-Galerkin-Petrov`s projection method which significantly expands its capabilities. The generalized “method of lines” can be used for plates of variable thickness, in problems of dynamics and thermoelasticity. The basic idea is to reduce the dimension of the spatial coordinates using the projection method, with a system of basis functions. This article is the first part of the work. It shows the reduced differential equations and proposes a new way of modeling boundary conditions.

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Analysis of space planning and design decisions modern cottage

(KNUCA, 2014) Klys, M.

This article report analysis of the major space planning and design solutions to contemporary cottages. Also considered the land on which built or being built these cottages. Realized statistical processing of the results. Definitely, a line of research of technical parameters of the device bearing structures cottages. Inspected the 68 modern houses and land plots for them in Kiev and Kiev region. Based on these data the histogram parameters most significantly influence the choice of process parameters erection. The results of analysis are a set of body-planning and design parameters that significantly affect the technological solutions.

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The hydraulic quencher dynamic vibrations

(KNUCA, 2014) Pelevin, L.; Karpenko, M.

Carried out a review and analysis of the developed hydraulic system for quenching dynamic oscillations. Made the mathematical model for determining the time delay operation of the hydraulic system of the dynamic quenching of oscillations. Performed a period’s calculation of cleavage of the soil and the time delay operation quencher dynamic oscillations from which it is possible in theory to establish the ability of the hydraulic system of dynamic quenching oscillations to operate in time. Developed hydraulic system dynamic quenching oscillations that occur inside the working unit to prevent the transmission of vibrations to the base of the machine. Conducted the analysis of the damper’s means and the method of dynamic damping on which developed hydraulic system for quenching dynamic oscillations. Was built mathematical sequence for determination of the time delay operation of the quencher. Parameters allow you to construct experimental model hydraulic system quenching of dynamic oscillations.

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Interaction study of the frame building with foundation weakened by the underground mines under the seismic load

(KNUCA, 2014) Sakharov, V.; Zhuk, V.; Skochko, L.

These article describes the researching results of the underground man-triggered cavities’ influence on the stress-strain state of the «soil base – foundation – structure» system elements under the seismic loads using the numerical simulation.

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Statistical research of retaining walls displacement on the results of geodetic measurements by analysis of variance

(KNUCA, 2014) Schultz, R.; Annenkov, A.; Khailak, A.; Strilec, V.

The analysis of geodetic measurements of retaining walls displacements in the residential quarter of the city of Kyiv is executed. For processing the observations, it was suggested to use a method of analysis of variance (ANOVA). The influence of changes displacement depending on the cycles of observations by one-factor analysis of variance is investigational. Method of one-factor ANOVA allowed also defining that for different retaining walls, a deformation process has a different dynamics. The relationship between cycles and retaining walls placement was determined using two-factor ANOVA. Method three-factor analysis of variance allowed additionally defining influence of location of deformation marks on the value of displacement. It was confirmed that the variance analysis method has great potential for the analysis of geodetic measurements, especially at the large volumes of observations.

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The effects of mirror reflection from flat and curved translucent structures

(2015) Karpenko, Valentina

The article gives examples of flat and curved translucent, mirror walling. There are presented variations of their formation by comparing with geometric transformations of form. Сombinatorial technique is applied.

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Intersectional junctions of the main roads in city SRN system (on the basis of Kyiv SRN system)

(KNUCA, 2015) Solukha, Igor

Issues of the concept of the street and road network (SRN), the role and place of transport planning junction in city SRN and the intersectional junctions of main roads at different levels in the SRN system are raised. The tasks of research: consider the concepts of SRN, road junction and main roads intersection at different levels. The technique of research: the typological technique of theoretical analysis for determining the role and the place of junction in the SRN system is implied. The results of research: It was established that intersections are built at different levels for the improvement of the traffic streams of vehicles and reducing the number of conflict points at the main roads junctions. Conclusions: intersectional junctions of the main roads in system of city street and road network is a source of transport and ecological problems of the city.

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Development of bell type water well with wide gravel filter

(KNUCA, 2015) Kayastha, Krishna

The purpose of this article is to present a new bell type water well construction with a wide gravel filter and its application. The construction of the water well has been developed and research has been conducted using physical and electrical modelling as well as in the practical field. Researches in this work are of analytical and experimental character. As the results of the research, optimal physical parameters of the constructions have been found and analytical − empirical formulae have been derived to calculate hydraulic parameters. Recommendation for application has been presented. The results received in this work can be used for the application of well construction. Further research is required to improve the physical and the hydraulic parameters of the proposed construction. The work has scientific and practical interest.

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Application of graph theory in the energy efficient architectural design

(KNUCA, 2015) Bolgarova, Natalia

Energy-efficient house is considered as a structure consisting of individual elements (volumes). To analyze their relationships with the architectural design of objects suggested to use one of the methods section of mathematics – graph theory. There are basic principles of the theory, which can be used to generate functional and spatial structure of the energy-efficientbuilding.

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