bluuebunny/crossref_metadata_2025 huggingface dataset:
The visualization system of patrol squad coordinates with a voice user interface
Authors: Medvedev M S , Schukov S V
Published: June 2019

The relevance of the topic is down to the need of developing a remote control system for operational groups of security companies with support for radio data speech recognition and location visualization. The developed system solves the problem of displaying information about the sectors of the orders on a map, which allows the operator (dispatcher) to visually monitor the situation in the given sector and ensures quick change of operators, eliminating errors under the influence of the human factor. For the convenience of managing the system, the voice command input subsystem was implemented and integrated.
Using the set-theoretic approach to formalize the concept of address
Authors: Rudakova G M , Gladkov S L , Korchevskaya O V
Published: June 2019

The paper deals with the problem of using the address as an identifier for the location of the property. A formal description of the common notion of “Address” (building address, citizen registration address, etc.) has been introduced, which can be used in information systems and geo-referencing algorithms. In the article, the address is analyzed as a set of values of details. A formal definition of address is formulated in the space of attribute values. The formal semantics of the introduced concept is presented. The principles are formulated, allowing to use the address as an identifier of objects in databases. The source materials for the article are federal and regional regulations.
Research of accuracy characteristics of measurement of coordinates in the ground-based radionavigation system based on pseudosatellites
Authors: Gladyshev A B , Dmitriev D D , Ratuschnyak V N , Golubyatnikov M A , Kartsan I N , Tsarev R Yu
Published: June 2019

The issues of measurement accuracy of coordinates in the short-range navigation system based on pseudosatellites are considered in the article. The analysis of the errors components the of measurement of radio-navigation parameters is given, the values of the geometrical factor are calculated for various options of system constructing
Evaluation of damage to objects of critical information infrastructure under the influence of destructive electromagnetic radiation based on hierarchical rank approach
Authors: Dvilyanskiy Alexey A , Rytov Mikhail Y
Published: June 2019

In article is presented hierarchical rank an approach to assessing damage to objects of critical information infrastructure under the impact of destructive electromagnetic radiations, providing formalisationt the specified objects and the account of their criticality with use of the conceptual scheme within the limits of expert system, and also distribution of influences of the opponent, with their subsequent classification as destructive electromagnetic attacks. One of the main tasks for the objects of CII facilities that provide vital public functions is the analysis and assessment of threats and consequences from exposure of electromagnetic impulses (EMI) of artificial origin, which can be used to disorganize CII control systems, suppression of technical means of protection (TMP) of specially protected objects, as well as causing significant economic damage.
The automated networks and regional users: risk analysis of their reactions to the attacks of different destructive orientation
Authors: Eshchenko A , Ostapenko G , Bataronov I , Tolstykh N
Published: June 2019

In work manifestations of an information war in the context of attacks to the automated networks by means of malicious codes and destructive contents are considered. Special attention is paid to users of the social automated networks which are final subject to these attacks. In this regard, authors offer a series of analytical expressions, the considering capacities of a great number of users with a different reaction to destructive content. At sufficient community of the offered technique, the emphasis is placed on the regional aspect. In particular, it is offered by polling to investigate regional resources for the purpose of forecasting of dangerous actions of their users induced by the content of different destructive orientation. All this in total forms risk model which can form a methodical basis for decisionmaking on counteraction of the attacks of the automated networks by means of destructive content.
Determination of factors of gambling establishments on the Internet
Authors: Avetisyan Boris , Truncevski Yurii
Published: June 2019

With the development of information systems, the spread of gambling institutions on the Internet is progressing, which affects the specifics of the training and education of qualified specialists in the field of combating crime. Such deviations affect the control of impulsive States, as a rule, accompanied by a range of other diseases, including suicides. For many players, this kind of game - it is fun, but for a significant number of people, such activities have a number of negative social, financial and personal con-sequences, expressed in criminal justice. In order to form competent professionals in this field, namely the prevention of all the negative consequences of the gambling industry. It is necessary to correct assess the determinants and causes of the high supply of gambling in the criminal market of services. Integrate into the training process the analysis of techniques and mechanisms for the implementation of the acts of the above category. This approach of teaching the signs of crime taking into account the current realities has applied value to explain the causes of the relevant deviations and improve the quality of education in the prevention and suppression of illegal gambling.
Expert system on the mobile platform for diagnosis of faults in the work of IT-equipment
Authors: Dorrer Mikhail , Popov Anatoly , Ovsyankin Aleksey
Published: June 2019

The problem of increasing the efficiency of maintenance and repair is being solved by applying flexible strategies using expert systems implemented in mobile applications. An expert system is a set of programs that accumulates knowledge of specialists in a particular domain and replicates this empirical experience for consultations of less skilled professionals. Mobile application is a modern software which intended for working on tablets, smartphones and other mobile devices. This article deals with a detailed description of the work of the expert system, the rules and facts of work are formed. The output of solutions diagnosing expert system is beeing developed. The implementation of the automatic synchronization of the mobile application with the technical documentation of troubleshooting is scheduled. The improvement of the mechanism for predicting the malfunction and solution as an expert system dialogue with the user is occurred. The organization of work in offline mode in the absence of a network connection has been planned.
Development of secure automated management systems based on web technologies
Authors: Kononov Dmitry , Isaev Sergey
Published: June 2019

This paper discusses security problems of developing municipal management information systems for Department of Municipal Procurement of the Krasnoyarsk City Administration (Russia). Authors describe the problem, goals, and tasks to be solved. Some security aspects are given, as well as original extended role-based security access control model for web applications and web services. This work describes two information systems developed by specialists of the Institute of Computational Modelling of the Siberian Branch of the Russian Academy of Sciences using described approaches. The systems have been in production for several years. The methods used to protect information are given, the structure of software is presented.
Multi-mode resonator for ultra-wide bandpass filter with good stopband performance
Authors: Podshivalov I V , Savishnikov M O , Leksikov A A , Dmitriev D D , Kartsan I N
Published: June 2019

A multimode resonator is proposed, containing five resonant modes that are incorporated in the passband forming. The structure is based on a dielectric substrate suspended in a metallic case that allows solving problem of electromagnetic compatibility. Due to features of the resonator’s structure, several higher modes do not excite that significantly improve the performance of the filter’s stopband. The resonator advantages are proved on the ultra-wide bandpass filter (101%) with small overall size (0.11λ
0×0.06λ
0×0.03λ
0) and good stopband performance (first spurious band locates at 8 GHz, suppression is 80 dB).
Advanced hybrid stochastic dynamic Bayesian network inference algorithm development in the context of the web applications test execution
Authors: Azarnova T V , Polukhin P V
Published: June 2019

The article is devoted to the application of dynamic Bayesian networks models for fuzzing web applications and development of effective hybrid algorithms for probabilistic inference based on particle filter algorithm. Dynamic Bayesian networks models allow to simulate the dynamic process transformation of web applications associated with the process of their constant instrumental and logical updates, and create a probabilistic structure required for learning process of testing the top web applications vulnerabilities, that able to use the evidence and inference results obtained in the retrospective and current testing slices and improve testing mechanisms in new time slices. The hybrid probabilistic inference algorithm for dynamic Bayesian networks models for testing web-applications, proposed in the current research, significantly increase the efficiency of the classical approximate probabilistic inference algorithms, well reflect the features of the temporary testing links formation and adapted to the detection of anomalous errors.
A problem decomposition approach for large-scale global optimization problems
Authors: Vakhnin A V , Sopov E A , Panfilov I A , Polyakova A S , Kustov D V
Published: June 2019

In fact, many modern real-world optimization problems have the great number of variables (more than 1000), which values should be optimized. These problems have been titled as large-scale global optimization (LSGO) problems. Typical LSGO problems can be formulated as the global optimization of a continuous objective function presented by a computational model of «Black-Box» (BB) type. For the BB optimization problem one can request only input and output values. LSGO problems are the challenge for the majority of evolutionary and metaheuristic algorithms. In this paper, we have described details on a new DECC-RAG algorithm based on a random adaptive grouping (RAG) algorithm for the cooperative coevolution framework and the well-known SaNSDE algorithm. We have tuned the number of subcomponents for RAG algorithm and have demonstrated that the proposed DECC-RAG algorithm outperforms some state-of-the-art algorithms with benchmark problems taken from the IEEE CEC’2010 and CEC’2013 competitions on LSGO.
Mathematical models of extended objects used for planning submeter resolution satellite imagery
Authors: Mozgovoy D K , Svinarenko D N , Kapustina S V , Tsarev R Y , Yamskikh T N , Kartsan I N , Saleh Ahmad M
Published: June 2019

This paper presents mathematical models describing extended objects with complex configuration used for planning satellite imagery with optoelectronic scanners of submeter spatial resolution. The most efficient spline approximation methods were used for mathematical description of extended objects with complex configuration. The proposed method ensures obtaining maximum coverage of the extended object in one-orbit period by choosing an appropriate spline smoothing coefficient, shifting and turning coverage contour. The results of computer simulation of extended object imagery are given, taking into account the swath width of the imaging instrument, the required scanning direction and limitations on retargeting angles range and satellite angular velocities.
Ecological and economic efficiency of tillage resource-saving technologies
Authors: Kozhevnikov N V , Zaushintsena A V , Romanov V N
Published: June 2019

Under existing conditions, intensive exploitation of land resources is accompanied by negative changes in agrogenic ecosystems. As a result of the anthropogenic impact on the soil cover, fertility and yield are reduced. To maintain the equilibrium of agrogenic ecosystems from the effects of anthropogenic factors causing soil degradation and loss of its fertility, it is necessary to introduce new technologies that combine safe ecological principles with the production of a stable yield of grain crops. The use of modern technologies of tillage provides the greatest economic effect and is able to increase soil fertility and the level of ecological purity of agricultural products, which is of great importance.
Coating of powder particles by a continuous method of reaction by using V-star chemical reactor
Authors: Bamatov Ibragim M , Rumyantsev Evgeniy V , Bamatov Dzhabrail M
Published: June 2019

The aim of this project is the application of microparticles to a particle of powder which leads to increase the stability of the detergent. Moreover, the idea of the project is to develop a process for coating a powder in a reactor with a continuous flow of reactants through the cooling crystallization, in other words, to change the method of chemical flow process reaction. In this project, the coating process will be illustrated on sodium aluminosilicate (particle core), which will confirm the concept of the powder coating. Moreover, the ultimate goal of this project is to ensure the stabilization of the powder particles (sodium aluminosilicate) with an inorganic coating mixture, where coating material contains a mixture of sodium sulfate and sodium carbonate dissolved in water. In addition, the sub-goal of this project is to investigate the importance of the size of the layer of coated material that needs to be optimized to achieve a desired performance.
Special aspects of modeling on accidental oil spills in inland sea waters
Authors: Zhilnikova N A , Matelenok I V , Smirnova A S , Smirnova V O
Published: June 2019

Intensive development of marine oil fields is characterized by significant pollution of sea environment, linked with leaks of diesel fuel and oil products during production activities on ships, or as a result of technical means accidents. To assess the potential scale of environmental impact mathematical modeling of hypothetical spills is required. The main processes of distribution and physico-chemical transformation of diesel fuel determined. The spreading of diesel fuel slicks on sea surface in case of accidental spills in storm conditions evaluated. Assessment of spatial-temporal picture of emergency development allows to select and prove a strategy for spills control during a storm wind.
Modern technologies of the load rationing on large water systems
Authors: Epifanov A V , Epifanova M A , Stroganova M S
Published: June 2019

A functional model of an automated management decision support system for load rationing in the framework of water management systems is proposed. Its main blocks are: automated control systems for natural and industrial wastewater, the state register of objects that have a negative impact on the environment, mathematical models for the transfer of pollutants in water bodies, geo-information systems for visualizing geo-data and modeling results. The advantage of the proposed system is the possibility of operational control over the sources of pollution and the regulation of the load from water users in real time.
Research of RDF-raw materials for prospective use in hardening construction and agricultural technologies
Authors: Epifancev K , Mishura T
Published: June 2019

In article research methods of recycling waste. The main selected methods - the development of fertilizers for soils and the creation of innovative building material. Currently, according to the Housing Committee of Administration of St.-Petersburg annually on landfill sites is disposed of 6.5 - 9 million cubic meters per year. Of this volume, only 1.5 million cubic meters (17-23%) is sent for processing in two landfills ("Novoselki" and JSC "Pilot plant MPBO-2 Yanino", project storage tailings according to an approximate assessment have 50 000 tons of RDF-raw materials). Also in St. Petersburg and the adjacent territory of the Leningrad region there are about 250 unauthorized dumps, which are placed, according to very rough estimates, from 500 thousand to 1 million cubic meters of garbage. A distinctive feature of illegal dumps is the high concentration of heavy and rare metals in the garbage. The article discusses the possibility of using aerobic waste composting as a fertilizer for soil and a solid building material, or alternative solid binder, highly abrasive granules. The applied research methods suggest that RDF wastes are commercialized and have the prospect of becoming a separate innovative product.
Accounting of externalities in the development of environmental engineering methods
Authors: Golosnoy A S , Provotorov V V
Published: June 2019

This paper is on the problem of effective business management related to the segment of long-term participants of various business activities, comprehensively interacting with the social and business environment. The study considers the periodicity of most economic processes, which has a complex characteristic. The optimization criterion was a functional, which included an assessment of the internalization of the impact of the results of such activity. As a result, a mathematical model was obtained, which serves as the basis for expert systems aimed at accounting of externalities of a wide range of nationwide, institutional, business and social activity.
Constructive factors optimization of the heat exchange model in the cooling chamber
Authors: Gorshenin A S , Krasnova N P , Rakhimova Y I
Published: June 2019

The most common method for the production of aluminum products is hot pressing of semi-finished products - aluminum ingots obtained by continuous casting into the mold. This method leads to the formation of a heterogeneous structure. To eliminate this problem, heat treatment is applied, one of which is homogenizing annealing followed by cooling in the chamber. For the study of heat transfer between aluminum ingots and cooling coolant in the chamber, a mathematical model was developed. It showed that the cooling time of ingots in the chamber depends on structural and operational factors. This paper is devoted to the optimization of the design factors of the mathematical model of heat transfer in the cooling chamber of aluminum ingots. The issues of optimization criteria are considered, the objective function is defined with restrictions on the set of feasible solutions of the function.
A comparison of the expected and statistical probability distribution of system failures
Authors: Dulesov A S , Karandeev D J , Bazhenov R I , Krasnova T G , Dulesova N V
Published: June 2019

The possibility of applying the information theory in the problem of comparing the expected and statistical probability distribution of failures of a technical system are considered. The paper presents a brief analysis of the processes of additive and multiplicative growth of the system indicators, among which the probability of failure-free operation and failure rate were considered. These indicators were considered in order to analyze the reliability of the system. The increase in reliability of the indicators is associated with the fixing of the failure rate of the system elements and the construction of probability distributions. In order to compare the two distributions, a method for measuring uncertainty is proposed, which includes Shannon’s measure of uncertainty, cross-entropy and Kullback-Leibler divergence. Together, they make it possible to determine the connection between the two different probability distributions of failures, to calculate the distance between the distributions, to identify the degree of difference between the real and desired state of the system during operation. An example of calculation confirming the importance of the participation of the offered method for measuring uncertainty in the problem of comparison of the expected and statistical probability distribution of system failures is given.
Installation for the implementation of the supercritical fluid extraction regeneration of nickel-molybdenum catalyst
Authors: Khazipov M R , Akhmetshin I Z , Pastushenko I L , Sagdeev A A , Galimova A T
Published: June 2019

The process of supercritical fluid extraction recovery of the catalyst at pressures of 10, 20 MPa and temperatures of 343, 373, 433, 473 K with pure supercritical carbon dioxide on the original device has been implemented. An increase in pressure and temperature has a positive effect on the catalyst regeneration process. With increasing pressure increases the density of CO2, and, consequently, its dissolving ability. With increasing temperature, the pressure of saturated vapors of compaction products increases and, as a result, their concentration in CO2 increases. In order to increase the efficiency of the supercritical CO2-extraction process for the regeneration of catalyst samples, carbon dioxide modification with various additives (chloroform, dimethylsulfoxide, acetone, ethanol, and non-polar inert with respect to the catalyst composition hexane) was used. Modification of supercritical carbon dioxide with ethanol and hexane at a temperature of 473 K and a pressure of 20 MPa led to an increase in the mass loss of catalyst samples by 12 and 14%, respectively, which indicate the removal of deactivating substances during regeneration by the method of supercritical fluid extraction.
Ecological engineering in mass media
Authors: Tarasenko T V , Chizhova E A , Vanslav M V
Published: June 2019

This article raises the problem of ecological engineering, taking the problem of unfavourable ecological conditions in Krasnoyarsk as an example and showing the way mass media and social networks illustrate it; how much the information on this problem is available for the citizens. Publications of four groups on social networks have been analyzed by means of content-analysis method of groups with different range of users’ activity. Semantic syntax method has shown the possibility to study the attitude of Krasnoyarsk citizens through the situation of action. The conclusion after the research is thesis of the necessity of conversation about ecological situation in the city between population and government, otherwise ecological protest campaigns might interfere political life.
Technology for managing thermal energy flows in industrial greenhouses
Authors: Dolgikh P P , Parshukov D V , Shaporova Z E
Published: June 2019

The paper presents technical solutions to improve the energy efficiency of growing greenhouse vegetables using artificial irradiation. The authors describe the technology of controlling the flow of thermal energy during irradiating of plants. A comparison of the developed technology with the fifth generation Ultra Clima greenhouse technology has been carried out. Key technical solutions have been identified, the introduction of which increases the efficiency of using thermal energy by 6%, increases the area irradiated by a single irradiator by 2.5% while maintaining photosynthetically active irradiation reaching the biocenoses, and provides an increase in the yield of vegetable crops by 2-5%. It has been established that with equal economic conditions of greenhouse growing of vegetables, the savings in energy costs compared to Ultra Clima technology is 5-6%, depending on the climatic conditions of the environment.
Anthropogenic risks of industrial areas
Authors: Taseiko O V
Published: June 2019

In the work we analyze the safety of an industrial region using a risk-based approach. Used methods for assessing overt and covert types of emergency situations. There were presented quantitative risk indicators on the territory of the Krasnoyarsk region with the subsequent assessment of the security of the region. The evaluations showed that hidden or potential health risks to the population of the cities of the Krasnoyarsk region are significantly higher than the risks realized.
Consideration the structure formation properties of crusher run stone screening as a solution of its construction and technological reuse environmental and economic issues
Authors: Makeev A I , Vlasov V V , Potekhin I A
Published: June 2019

The article is dedicated to the search of ways of decreasing environmental damage from the quarry industry, generating crusher screening. Construction and technological reuse is offered as the most effective way of waste dump elimination. In this regard, screening of stone crushing are considered a valuable raw material component of high quality fine grain concretes, having mechanical, mechanical and physical as well as physical and chemical activity, which is effected in the processes of structure formation of concrete on its macro-, meso- and micronanolevels. The results of research of screening genesis, its characteristics, and its influence on the structure formation processes and the properties of fine grain concrete are presented. The suggestions for conditioning of screening with the view to increasing the efficiency of the concrete produced with their use and increasing the demand for screening in the construction market are validated.
Analysis of the state of the air environment in Krasnoyarsk based on atmospheric pollution indexes
Authors: Tokarev A V , Shaparev N Ya
Published: June 2019

This study examines the state of the atmosphere in Krasnoyarsk in terms of sustainable development, and based on atmospheric pollution indexes API-5, AQI. The data presented in state reports on the state of the environment from 2007 to 2017, as well as monitoring data obtained from automated observation posts located in the city territory were used.
Ecological engineering in the construction and exploitation of roads with technogenic materials
Authors: Shepelev I I , Eskova E N , Potapova S O , Nemerov A M , Bochkov N N
Published: June 2019

The article describes the developed engineering technological measures. They increase the operation life of road structures with the use of technogenic non-toxic materials. It is recommended to use activating additives to accelerate the process of road mixtures hardening. The introduction of gypsum anhydrite waste in an amount of 5 % into the crushed-nepheline road mixtures provides an increase in their strength characteristics by 1.8–2.2 times and increases the frost resistance of the road surface. This allows recommending the developed structure of region road pavement in regions with an average monthly air temperature of the coldest month from -15oC to-30oC. The conducted industrial tests of the proposed engineering technological measures confirmed the results of the research and provided their practical implementation in the technology of laying the lower base of the road pavement.
Graphoanalytical method for determining the indicators of thermal-oxidative stability of lubricating oils
Authors: Kovalsky B I , Bezborodov Yu N , Shram V G , Vereshchagin V I , Lysyannikova N N , Petrov O N
Published: June 2019

This article presents the results of a study of the effect of temperature tests on indicators of thermal oxidative stability: optical density, evaporation, coefficient of thermal oxidative stability. A grapho-analytical model is proposed for determining these parameters for a wide range of temperatures without temperature control of oils using experimental results obtained at two temperatures. A comparative evaluation of the experimental data with the calculated ones obtained using the grapho-analytical model has been carried out.
Investigation of the influence of wind stress in autumn leading to unstable stratification in a meromictic lake using three-dimensional numerical modeling
Authors: Iakubaylik T V
Published: June 2019

Currents in lakes affect the distribution of hydrophysical and hydrobiological characteristics. Three-dimensional model study is an important step toward an improved understanding and reliable prediction of the distribution of hydrophysical fields. Salt stratified lake Shira refers to meromictic reservoirs. The depth of the upper mixed layer depends on many factors (even a few isolated, fairly rare facts of its complete mixing are known). The study of the influence of each of them separately is the task of mathematical modeling. The model results indicate that strong wind stress in the autumn can result in unstable density stratification, leading to intense vertical circulation.
Mathematical modeling of isoparaffins dehydrogenation in fluidized bed reactor
Authors: Solovev S A , Soloveva O V
Published: June 2019

A mathematical model has been built and a simulation has been carried out for the isoparaffins dehydrogenation reaction in a fluidized bed reactor using the example of isobutane dehydrogenation to isobutylene. The parameters for the model construction are determined on the basis of experimental data. Conducted numerical studies with the selection of the average diameter for the polydisperse catalyst. The calculations were performed for cases of monodisperse and bidisperse composition of particles. The analysis of the influence of the fine particle presence on the yield of the reaction product in the numerical simulation has been carried out.
Risk management of emergence of dangerous events on the basis of three-planimetric model of reliability of technological systems
Authors: Serdyuk Vitalij , Denisova Elena , Kolpakova Tatiana , Utuganova Valentina , Kovalkovskay Nadezhda
Published: June 2019

The reliability of machine-building industry technological systems of is determined by the risks of hazardous events: failures of technological equipment, production items, executors of specified technological processes. The paper proposes the use of the G. Heinrich pyramid, built on the basis of the risks of technological system failures, which include primary failure, secondary failure, initiated failures, multiple failure, necessary to determine the significance of the influence of failure risks on the possibility of dangerous events. This is necessary for the organization of safe working conditions for workers through risk management of hazardous events based on a three-planimetric model for managing the reliability of technological systems. The authors have developed a three-planimetric model for managing the reliability of technological systems. The incident management process takes place on the first contour. According to the analysis of the statistics of incidents, the failure factors are managed on the second contour of the model. The third contour is process functionality management. The contours use the “Analytics” database, updating it and the database of possible options for technical solutions with the subsequent adjustment of operating conditions or methods for managing failure risks. Based on the obtained statistical information databases, solutions are being developed to manage the indicated risks of dangerous failures of technological systems. The control contour is closed in the cycle of technological system functioning and its risk management. Automation of the management process can be achieved through the use of resources of a machine-building organization and the development of an information management system for a unified technical condition monitoring system (UTCMS) based on the use of the three-planimetric control system.
Summertime thermal regime of water downstream of the Krasnoyarsk hydroelectric power plant
Authors: Shaparev N Ya , Bondarenko E V
Published: June 2019

Summertime hydrothermal regime of the Yenisei River downstream of the Krasnoyarsk hydroelectric power plant is modeled based on a deterministic approach. To that end, the Fourier equation is used and the following physical processes contributing to the heat exchange between water and the surroundings are taken into consideration: absorption of direct and scattered solar radiation by water, absorption of downwelling thermal infrared radiation from the atmosphere by water surface, thermal infrared radiation back from the water surface, convection of heat and heat loss due to evaporation of water. A clearskies river thermal regime under no wind is studied in a 124-km stream reach below the power plant and the obtained results are compared against temperatures recorded at gauging stations.
Restoring of worn-out parts of electrical machines via compositional electrochemical iron-corundum coating
Authors: Panteleev V I , Petukhov R A , Sizganova E Yu
Published: June 2019

Galvanic build-up of iron layer is an effective method of parts restoring during repair works. The productivity of this process is 15-20 times higher than of chroming. The high settling velocity of iron and low costs of the source material determine the economic practicability of this method. Up to 3 mm can be applied by iron plating, which is necessary in case of high parts wear.
Sectional approach to researching of two-phase BLDC motor
Authors: Krivilev A V , Dunich E A , Penkin S S
Published: June 2019

An approach to researching of two-phase brushless DC motor,based on winding’s section is proposed. A classification of control methods by section connectionkind and commutation methods is developed. An example in case of independent windings’ layout is given.Torque-speed curves are obtained. A comparative analysis of them is carried out and recommendations to drive systems’ developers are given.
Quality control of the concrete and corrosion damage of cables of prestressing reinforcement of KA beams, bridge in Chomutov
Authors: Rehacek S , Citek D , Krystov M , Kolisko J
Published: June 2019

The aim of this paper is to assess the condition of the diagnosed bridge structure, at which previous bridge inspections identified corrosion damage of cables of prestressing reinforcement of KA beams, to assess the extent of corrosion damage of prestressing reinforcement, the condition of chloride ions in concrete of the bearing structure, and to draw up a detailed corrosion assessment of the prestressing reinforcement, then to propose a possible method of the bridge renovation with partial use of new materials (UHPC).
The impact of aggregates from recycling, discharge time and mixing technique on the consistency of concrete
Authors: Sicakova A , Urban K
Published: June 2019

Concretes prepared by the application of the triple mixing approach and by the use of both recycled concrete aggregate (RCA) and recycled clay brick aggregate (RBA) were tested in terms of loss of consistency. Fly ash was used to improve the performance of recycled aggregates during mixing – this is a specific aspect of the triple-mixing method. The slump test was performed immediately after mixing, as well as after next 90 minutes. The results were evaluated from the point of view of prolonged discharge time. Concrete consistency changes with time, having the impact on technological processes at construction site. Over the discharge time, the RBA-based concrete achieved the worst result – by 87% slump loss. Discharge time influenced the slump loss more favourably in the case of normal mixing and in the case of using natural aggregate (NA). The substitution of NA with both the RCA and RBA caused the slump loss turned worse, while RCA provided better results than RBA. However, the substitution of NA with both RCA and RBA resulted in more favourable change in the slump loss when concrete was mixed by 3M method.
Wood pulp as a potential raw material source for manufacturing bio-based building materials
Authors: Stevulova N , Hospodarova V , Vaclavik V , Dvorsky T
Published: June 2019

The application of bio-based material such as cellulose fibres derived from renewable source to cement mortars was investigated and the properties of fresh mixtures and hardened mortars were characterized. The mixtures composition consisted of combined addition of the selected kind of cellulose fibres (bleached wood pulp) and superplasticizer (polycarboxylate ester). The aim was to produce a cement mortar with the improved properties for indoor application. The 0.5 wt.% fibre addition (from weight of filler and binder) and superplasticizer dosage of 1% in the mixtures were used. Reference cement mortar did not contain cellulose fibre and superplasticizer. The comparative study of the fresh fibre cement mixture properties has been showed worse flowability behaviour of mixture with plasticizer, as expected. The the beneficial effect of the superplasticizer was not proven even on the compressive and flexural strength of fibre cement mortars after 7, 28 and 90 days of hardening. The performances of the mortars were dependent not only on fibres and superplasticizer nature but also on the organic/inorganic interface.
Testing and mechanical properties of high strength concrete
Authors: Sucharda O , Bilek V , Mateckova P
Published: June 2019

The paper deals with mechanical properties of high-strength concrete, which are illustrated in various laboratory tests. The aim of the paper is to compare the possibilities of concrete compressive and tensile strength assessment and modulus of elasticity assessment. Results of nine type laboratory tests are presented in summary. Tested material properties are complemented with testing of small structural element, the beam without shear reinforcement. The behaviour of structural element is analysed also with a non-linear numerical model that respects the quasi-brittle properties of the concrete, where fracture-plastic model for concrete is used.
Effect of aggregate gradation on lime mortars rheology
Authors: Vyšvařil M , Vozák R
Published: June 2019

The influence of basalt, limestone, and quartz aggregate and their various gradation on rheological properties of air lime mortars with constant water/binder ratio and binder/aggregate ratio is monitored in this work. It was found that the rheology of fine-grained lime mortars is influenced not only by the shape of the aggregate, but also by its granulometry, especially by the content of fines. The lime mortars with basalt, limestone or quartz aggregate are shear-thinning non-Newtonian liquids. Their shear stress, yield stress, and flow index decrease with increasing aggregate fraction. The viscosity of lime mortars is markedly influenced by the amount of lime matrix. The lime mortars with quartz and limestone aggregate are rheopectic suspensions.
Influence of glass and polymer fibres on physical and mechanical properties of cement composites
Authors: Štefunková Z , Ledererová M , Cápayová S , Gregorová V
Published: June 2019

This paper focused on the effects of using glass and polypropylene fibres in cement mortars. Were used glass fibres Cem-FIL Anti-Crak HP 12mm long and polymer fibres BeneSteel 55 (shortened to 12mm) in 1wt.%, 3wt% and 5wt% of cement. The water and filler dose were constant. Tests were performed on 40x40x160mm beams. From the results we have found that by the addition of fibres, the shrinkage of hardened cement composites is eliminated, with the use of polymeric fibres for better results. The filaments also positively influenced tensile strength at bending. By adding the fibres, the consistency of the fresh mortar deteriorates, and the bulk density of fresh and hardened mortars decreases, resulting in less compressive strength.
Threshold of the chloride to hydroxide ions ratio in relation to steel reinforcement corrosion
Authors: Rovnaníková P , Vořechovská D
Published: June 2019

A simple method for determining the corrosion dependence of steel reinforcement on the content of chloride and hydroxide ions is described. Steel test specimens were immersed for nine months in solutions with 0.03%, 0.3% and 3% NaCl with increasing concentrations of hydroxide ions, and pH of 8.5 to 13. The test specimens were cleaned of corrosion products and weighed at given time intervals of one month. The dependence of mass loss expressed as a percentage of the concentration of chloride and hydroxide ions was determined. The concentration threshold of the cCl−/cOH− ratio of 0.5 was evaluated from the results. Higher values of this ratio resulted in the formation of corrosion products on the surface of the test specimens.
Study of temperature influence of cement and water on the fresh cement paste consistency
Authors: Figmig R , Estokova A
Published: June 2019

The consistency of a fresh cement paste, which is formed after mixing Portland cement with water, depends significantly on the water to cement ratio (w/c), the cement fineness and its composition, but also on the other parameters as temperature of cement and water. The paper is focused on researching the influence of increased temperature of cement and water on the fresh cement paste consistency. Various cement pastes with different w/c ratio (0.28, 0.32 and 0.36) and different temperatures of water and cement (20±2°C, 40°C, 60°C) were investigated. The consistency of cement paste was measured by Vicat roller penetration method. The tendency of losing the consistency of the fresh cement paste with increasing of its temperature was observed and exhibited as linear correlation with the coefficient of determination R2(0.28) = 0.9695 and R2(0.32) = 0.9147 respectively.
The issue of plastic waste in the environment and its possible uses as a substitute for filler in lightweight concrete
Authors: Ledererová M , Štefunková Z , Gregorová V , Urbán D.
Published: June 2019

The specific nature of plastics causes specific problems in waste management. Plastics are relatively inexpensive and versatile with the potential for versatile use in industry, which has led to their rapid development over the past century, which still persists. The aim is to look for the possibility of reusing plastic waste as one of the lightweight filler fillers. It used plastic recycled material recycled from EVA plastic packaging and polystyrene recycled material in various proportions. All are among the medium-recyclable plastics according to their recycling rate. The experimental part of the work is devoted to the verification of the effect of the filler dose on the monitored physical and sound absorption parameters.
Assessment of the resistance of ventilated facade system by vacuum testing
Authors: Schmid P , Daněk P , Rozsypalová I , Holomek P , Juránek P
Published: June 2019

The aim of this research was to determine experimentally the mechanical resistance of preset ventilated facade systems exposed to wind suction. In accordance with the European ETAG 034 Guideline, Part 1, seven facade assemblies were tested. The wind suction load was simulated in a vacuum test in the AdMaS centre using the universal vacuum loading system. The test was performed with a load increasing in increments, where after each level, the specimens were unloaded. The effect of the density of connections of load-bearing plates with the structure of subframes was demonstrated. Further, the resistance to wind suction of specimens with timber subframe was slightly higher than that of specimens with aluminium subframe.
Test of the tensile load capacity of a timber structure joint with an inserted nail plate
Authors: Schmid P , Daněk P , Rozsypalová I , Plaček V
Published: June 2019

The aim of this paper was to determine the axial tensile load capacity of timber structure elements with inserted metal plates with welded nails. The tests were performed on three specimens in the laboratory of the AdMaS centre of the Faculty of Civil Engineering, Brno University of Technology. The tensile force was applied on the specimen by increasing the force up to the specimen failure. The inductive displacement transducers continuously measured the displacement of the inserted joint plates with regard to timber prisms. The tensile load-bearing capacity of the tested joint was determined at 205.0 kN. Due to the advantages, the tested joints with inserted nail plates seem to be appropriate for joining suitable timber elements.
Comparison of material properties of steel fiber reinforced concrete with two types of steel fiber
Authors: Marcalíková Z , Procházka L , Pešata M , Boháčová J , Čajka R
Published: June 2019

The work is focused on the area of mechanical properties of two types of Steel Fibers for reinforced concrete. In both cases, the same concrete mixture is used. The Steel Fibers used differ in shape. The first one is short and straight fiber and the second one is 3D steel fiber. Steel Fiber Reinforced Concrete was prepared at a dosage of 40 and 75 kg steel fibers/m3. The experiment includes determination of strengths, concretely compressive strength, a three-point flexural test and Splitting Tensile Strength test. The results are summarized; fracture mechanics parameters necessary for structural modeling are also included.
Moisture sorption and thickness swelling of wood-based materials intended for structural use in humid conditions and bonded with melamine resin
Authors: Böhm M , Kobetičová K , Procházka J , Černý R
Published: June 2019

When used in construction, the properties of wood-based materials they are mainly affected by moisture. Moisture sorption and the associated swelling has an impact on the resistance of materials to biocidal attacks, on their mechanical properties or air permeability, and on comfort of use and durability of the structure. Equilibrium moisture content (EMC) and thickness swelling (TS) depending on the relative humidity for plywood (PW), particleboard (PB) and oriented strand board (OSB), for load-bearing purposes in humid environments and bonded with melamine-urea-formaldehyde resin (MUF), are studied in detail in this paper. Equilibrium moisture content and thickness swelling are influenced by the type of material, density, quantity of adhesive composition, and paraffin. The highest values of equilibrium moisture content were found in plywood, whilst the highest thickness swelling was achieved by OSB. A high dependency of nonrecoverable thickness swelling on the equilibrium moisture of the material was also ascertained. The proportion of nonrecoverable thickness swelling increases exponentially, in particular if the material’s equilibrium moisture content exceeds 12%.
Experimental study of the modulus of elasticity of concrete at different ambient temperature
Authors: Bujnakova P , Jost J , Farbak M , Kotes P
Published: June 2019

The structural performance of concrete construction and bridges is directly influenced by the strength and the modulus of elasticity of concrete. The modulus of elasticity is an input parameter to the creep compliance important especially in design calculation of large concrete bridges. The development of strength and modulus of elasticity at the early ages depends also on the temperature of the environment during casting and curing of concrete. The effect of ambient temperature on modulus of elasticity is however not assessed by the EN 1992-1-1 [1]. The experimental program was focused on determination of static modulus of elasticity and compressive strength cast and cured at ambient temperature +20°C and temperature -5°C at different time. The paper also formulates preliminary design recommendations applicable in practice.
Property Rights, Land Disputes and Water Scarcity: Empirical Evidence from Ethiopia
Authors: Di Falco Salvatore , Laurent‐Lucchetti Jérémy , Veronesi Marcella , Kohlin Gunnar
Published: June 2019

This article investigates the relationship between insecure property rights and land disputes using farm household panel data from the highlands of Ethiopia. Our identification strategy relies on the gradual rollout of a land certification program. We find that tenure security significantly reduces the likelihood for a farm household to experience land disputes. We further document that water scarcity during the rainy seasons is an important determinant of land disputes. However, farm households that have been certified are significantly less likely to experience land disputes triggered by water scarcity than farm households without land certification.