The research of influence of periodical signal discontinuity on spectrum form is considered in the article. The numerical modeling of the system of discontinuous signals is performed. The spectrum of the system built from time discreet sampling is analyzed. The plots of the sample correlation coefficient between spectrums of continuous and discontinues signals are shown in the article. The research is needed for the development of digital measuring system for quartz plates frequency detecting.
Keywords: amplitude signal spectrum, discontinuous signal, quartz plates
The atomic structure of bimetallic nanoparticles of Pt-Ag composition, which are the part of metal-carbon electro-catalysts PtAg/C, is studied by means of EXAFS spectroscopy using the suggested technique. These materials have been prepared by methods of consistent and simultaneous deposition of Ag and Pt atoms from aqueous ethylene glycol solutions of their salts with subsequent acid treatment. The values of the structural parameters of the near environment of platinum atoms are determined. The nature of the distribution of components in nanoparticles is established. Cluster models of nanoparticles are constructed. The fraction of Pt atoms in the working shell and its dependance on preparation methods in each case are determined.
Keywords: Metal-carbon electrocatalysts, bimetallic nanoparticles, Catalysis, Platinum, X-ray absorption spectroscopy, atomic structure
In design and manufacture recently interest to a solving of problems of fluid-structure interaction is constantly incremented. MSC.Dytran has opportunities of calculation of fluid-structure interaction. MSC.Dytran has found application in different fields for example in general safety analysis.In this article algorithms of fluid structure interaction , used in MSC.Dytran, are described. Analysis of one-contour geodetic domes under blast loads are described.
Keywords: visualization, computational model, geodetic dome, numerical modelling, blast load, pressure, stress.
As a rule, the information they have guides for fatigue testing geometrical designs, gives only the evaluation of the characteristics and design lay stock in several, and sometimes in tens times exceeds the tensile strength of the material. And saving of material, from the point of view of obsolescence, product should be developed on a certain resource. For details, which operate in the field of elastic deformations and calculated in operation for a given mode of operation should lay in the design of the guaranteed resource. To do this, for example, compensating coupling method is suggested, which is based on the calculation methods of CAD/CAM/CAE/CSE NX 7.5 and field tests considering the impact of technology of surface hardening. The character of strain in «elastic element» in NX 7.5. The calculations of the elastic element module «flexible body» NX 7.5, but due to the fact that the calculation is impossible to consider technological parameters of manufac-turing is conducted equivalent full-scale tests. Accordingly, designed and built a stand for equiva-lent tests. Finally, for comparison, is a computer simulation to calculate large displacements and complicated movements of the coupling. For this we used the application NX 7.5 «Simulation of kinematic mechanisms» with the attraction tools «Flexible body».
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
The quantum and chemical simulation (HF/MP2, cc-pVDZ basis) of diphenyl-2,2',4,4'-tetraamine (DPTA) molecule properties allows to determine the its thin film pyroelectric properties since hydrogen bonds between molecules in the film are weaker than intramolecular bonds. The study of a DPTA photosensitive pyroelectric film microstructure enables one to assume that the dipole moment of the needle-shaped crystallines densely stacked and extended along a film surface is aligned perpendicularly to the surface. The possibility of the reproduced control for DPTA properties may be used when producing the most effective pyroelectric film for photodetectors in infrared wavelength range.
Keywords: Diphenyl-2,2',4,4'-tetraamine, quantum chemical simulation, pyroelectric material, thin-film structure
The article is devoted to modelling of process of decision-making in difficult systems in the conditions of total uncertainty. The problem is formulated on the basis of synthesis of concepts of the control theory and decision-making, the theory of fuzzy sets and the fuzzy logic, the theory of hierarchical multilevel systems, the utility theory and the theory of games. The given concept expands possibilities of the account uncertainty the various nature, typical to mathematical description of the surrounding validity. Problems of search of decisions in an fuzzy hierarchical control system are designated. The way of the description and finding of alternative decisions in multilevel difficult systems is offered in given article. The algorithm is based on information processing in the form of fuzzy intervals taking into account two kinds the politician conservative and aggressive on the basis of criteria «maxmin» and «minmax». The method of projection on individual interval is used for comparison of the fuzzy intervals presented on various dimension scales. The example showing work of algorithm of a choice of two groups of alternatives is resulted: optimistic and pessimistic on a level of hierarchies of the purposes in the conditions of total uncertainty.
Keywords: Difficult system; decision making, fuzzy interval, the control decision; total uncertainty
This article discusses current issues of modern use of the benchmarking system on the example of the clothing companies. Benchmarking is able to dramatically affect the economic and marketing activities of enterprises, as well as foster a constructive dialogue between business structures. Research results revealed the garment industry in the Rostov region, related to the type Brand Non-Recognition and Brand Recognition.
Keywords: benchmarking, comparative analysis, marketing environment, competitiveness, market conditions, the image.
This article describes a method for producing two-component nonisocyanate insulating foams and technology of its spraying on the insulated surface. It describes the device, which, along with standard equipment, includes principally new design of components pre-mixing chamber. Constructive solutions described in the article will allow using the compositions which have different time and temperature of curing than conventional PU foams.
Keywords: Keywords: spray foams, insulating foams, nonisocyanate urethanes, pre-mixing chamber.
The basic virtue of the sowing apparatus of an overpressure is possibility of conducting of sowing on the big speeds and with high uniformity of dispensing of seeds. But the processes occurring in the sowing apparatus of an overpressure at dispensing of seeds, are insufficiently studied. In the article one of stages of process of dispensing by the overpressure sowing apparatus - transportation of a unit seed by dosing elements of a seed disc is observed. The forces acting on a seed in the course of transportation with a dosing element of a seed disc are defined. The gravity, centrifugal force, force of air drag and pressure force of air refers to to them. The scheme of forces is presented. As a consequence of theoretical research dependence of magnitude of an overpressure in the seed vessel from key parameters of work of the sowing apparatus of an overpressure has been defined. Graphs of theoretical dependence of pressure in the seed vessel from diameter of holes and a seed disc angle of rotation are built. The analysis of the gained results allows to draw following conclusions. The increase in diameter of holes of dosing elements of a seed disc leads to considerable decrease of the pressure necessary for transportation of a seed. At increase in an angular velocity of a seed disc pressure necessary for the secured transportation of a seed is augmented. The increase in an angle of rotation of a seed disc puts insignificant agency on pressure in the apparatus seed vessel.
Keywords: seeds, transportation, dispensing, forces, an overpressure, a dosing element, a nominal diameter, dependence.
In the article results of theoretical researches of the rotor scatterer of fertilizers are resulted. For elimination of adverse conditions shock interactings of particles of fertilizers with rotor vanes, possibility of application of curvilinear vanes is observed. The forces acting on a particle which moves on a curvilinear vane are justified. Schemes of act of forces and the scheme of interacting of particles of fertilizers with a curvilinear vane taking into account width of a torrent are presented. The transcendental equation numerical solution on a method the Runge-Kutty is resulted. The analysis of dependences of the kinematic operating modes of the scattering apparatus from design parametres of a curvilinear vane is carried out. The time of interacting of a particle of fertilizer with a surface of a vane taking into account its curvature and a slope is defined. Conclusions are drawn on possibility of lowering of crushing of particles of fertilizers at the expense of blow decrease in a normal direction.
Keywords: fertilizer, vane, rotor, curvature, angle of slope, speed, crushing
To improve the quality of developed software for the controller is proposed to take into account the principles of programming in FBD and CFC. Gives practical recommendations for the use application of. Especially, this approach is acquitted for complex systems of automatic control and regulation of high risk. The proposed method reduces the requirements for qualification of personnel, increases productivity in extreme situations, reduces the possibility of errors in the adjustment programs.
Keywords: Programming principles, identity numbering algoblocks similar algorithms, the in-between software cleat, the principle of non-rigid numbering, quality and reliability of software.
A problem of signal estimation (or estimation of some parameters of the signal) based on measurement results obtained by means of distributed sensor network is considered. The system formed by spaced sensors called nodes (or motes) obtains information about a stochastic process. It is supposed that there is a single source of the information and the distortions are linear.
Every node gets incomplete and distorted knowledge about the observed process and operates on the low sampling rate. Combined processing of the information obtained from the different sensors makes possible to perform the integrated estimation which is usually much more accurate.
The application of the information performance criterion provides high robustness in the presence of the noise and the measurement uncertainty and, theoretically, gives the most complete information, while the measurements have severe constraints.
Due to the multirate signal processing it is possible to decrease requirements on sensor’s sampling frequencies, to reduce the channel loading and the current consumption of sensors. Furthermore, the computational load falls in real-time applications.
Keywords: multirate signal processing, sensor, node, mote, information, stochastic process
The analysis of electromagnetic processes of thyristor controlled voltage regulator consisting of triple-wound transformer with thyristor units is possible only by means of computer modeling. The synthesis of triple-wound transformer by means of block diagram method is concerned here. As a platform for modeling use visual simulation package Simulink. Key assumptions in the development of nonlinear mathematical model of the transformer are generally accepted.
Keywords: three-phase transformer, thyristor voltage regulator, simulation, Simulink
The article concludes data about the technique of carrying out and results of a small-sized energy saving grain flattening farm machine of researches on the firm inclusions admission, on productivity and thickness of a cereal product. Practical recommendations for the most effective operation of an offered grain flattening machine are provided.
Keywords: flattening, grain flattening machine, breast, private farming, feed nutrients
This paper proposes criteria for the optimal choice of a database management system (DBMS), based on the requirements to this system. Empirically assessed criteria and method of analytic hierarchy process for decision making were used to carry out the comparative analysis of several DBMSs, implementing relation data model and having similar functionalities. The obtained matrixes of pair-wise comparison are examined for concurrence by calculating indices described in the article. As a result, the database management system for the own project is rationally chosen.
Keywords: DBMS, method of analytic hierarchy process, criteria, matrixes of pair-wise