Search

In this paper, the pulsating combustion of a premixed propane-butane fuel with air in a vortex combustion chamber is considered. The conclusion of the refined frequency equation is made. The characteristic of the mixture supply system is given. more...

It is noted that digital artificial agricultural ecosystems imply the use of digital control systems of abiotic factors, with appropriate software and algorithms. The algorithm through thermoregulation ensures the highest flow of moisture and nutrients through the plant. The leaf temperature corresponds to the maximum rate of photosynthesis. It is shown that CO2 assimilation and thermoregulation are related, as water vapor and carbon dioxide pass through the same stomatal openings. The aim of the research is to establish, for selected samples of vegetable crops, the level of CO2 concentrations at which the biomass growth of these crops is maximal, as well as the degree of thermoregulation heat reduction for average CO2 concentrations of 1000 ppm and higher. A specially designed stand was used for the studies. The following crops were used for studies of the influence of CO2 concentration on the thermoregulation heat: from vegetables the cucumber cultivar “Courage” and from green spices the cultivar “Coriander”, and for studies of the influence of CO2 concentration on productivity - salad cultivar “Gambrel”. The samples were planted in four cubes of mineral wool, in each of which five plants were placed. Variable concentration was provided by a system of carbon dioxide supply from a cylinder with a reducer, a hose and an electromagnetic valve. It was experimentally proven that the increasing of the CO2 concentration leads to an increase in the weight of green mass, and this increase has an extreme at the concentration of 2944 ppm (for the lettuce culture), with a slight decrease in thermoregulation temperature (for cucumber by 1.4 °C, and for coriander by 0.47 °C). Such a decrease will not lead to a significant deterioration of thermoregulation processes and may not be taken into account in the operation of digital control of them. more...

The theoretical treatment of the scattering of light by LO-phonons under one-photon and two-photon excitation near resonance with the An=2and Bn=1exciton levels in a CdS crystal is given. The influence of the complex structure of the top valence band on these levels is taken into account by the use of the perturbation theory. Assumption of the nonzero matrix elements of the dipole transitions between the A and B sub-bands leads to the fact that the linear combinations of the 1s and 2p exciton wave functions conform to the two “perturbed” energy levels. The possible manifestations of this mixing of states in the resonance Raman and hyper-Raman scatterings are considered. more...

The meat industry is one of the most important sectors of the economy closely related to animal husbandry. In the human diet, meat is the main source of animal protein. Therefore, quality of a final product is extremely important and depends on many factors at all stages of the production. Requirements for parameters of food safety and quality are established in the most countries and are revised permanently depending on the new scientific data. In the Russian Federation and the Customs Union, the controlled parameters are normalized on the basis of scientific data and approved for use in the relevant Technical Regulations. In order to avoid actions misleading consumers, special requirements for product labeling have been developed. In particular, the labeling of slaughter products and meat products must be conformed in accordance to the Technical Regulation of the Customs Union "Food products in terms of their labeling " - TR CU 022/2011, as well as to the some clauses of the Technical Regulation TR CU 034/2013 On the Safety of Meat and Meat Products. According to the working regulation, the manufacturers must indicate nutritional parameters (protein, fat, carbohydrates) of meat products on the product label as the parameter true values. At the same time, each standard for analytical methods includes a permissible relative error of the measured value at the confidence level of 0.95, which had not to be exceeded under the conditions described in the standard. In that way target measurement uncertainty is established. This paper shows the possible risks of false decisions when assessing meat products for its compliance with the labeling, depending on the measurement uncertainty, as well as methods for minimizing these risks. more...

Paper presents data of the experiments with the advanced model of voice authentication. The main idea of the research is to prove or deny the hypotese that adding generated fake data to the training set of the background model help to increase the probability of detecting fake data of the target announcer. Processing the results of a series of experiments did not confirm the hypothesis. more...

A technique for evaluation of risks in a sausage conformity assessment is developed. Measurement uncertainty, correlation and mass balance constraint are considered. A multivariate Bayesian approach and a Monte Carlo method are applied. Risks in assessment of sausage "Braunschweigskaya" are evaluated as a case study. R code for the risk evaluation is provided as electronic supplementary material. more...

We present a photoluminescence study of In(As,P) monolithic nanoinclusions into Si (100) substrates. The structures were grown in openings of the silicon substrates using an original approach based on the metal-organic vapor epitaxy method. The obtained arrays of In(As,P) nanoinclusions into the Si (100) surface were investigated by scanning microphotoluminescence spectroscopy. The obtained results show high crystalline quality of In(As,P) inclusions with broad emission peak in the near-infrared range of wavelengths. more...

Multi-pass spectroscopic absorption cells are commonly used in gas spectroscopy to increase the sensitivity of the measurements. The possibility of systematic errors of such measurements was shown in this paper, even for the case when intrinsic transmittance of the cell alters weakly on the line width. The errors could be manifested both in perturbation of the shape of the absorption line and in the sufficient overestimation or underestimation of the absorption strength. more...

Using chemical etching it was shown that the density of dislocation in lithium niobate (LN) single crystal wafers is higher near the surface in depth about 20 um than in the depth of crystal. It caused to change of diffusion coefficient during the waveguide formation with proton exchange (PE) method and can increase DC-drift of intensity optical modulators based on PE-waveguides. more...

Oscillations of crystal lattices determine important material properties such as thermal conductivity, heat capacity, thermal expansion, and many others; therefore, their study is an urgent and important problem. Along with experimental studies of the nonlinear dynamics of a crystal lattice, effective computer simulation techniques such as ab initio simulation and the molecular dynamics method are widely used. Mathematical simulation is less commonly used since the calculation error there can reach 10 %. Herewith, it is the least computationally intensive. This paper describes the process and results of mathematical simulation of the nonlinear dynamics of a 3D crystal lattice of metals using the Lennard-Jones potential in the MatLab software package, which is well-proven for solving technical computing problems. The following main results have been obtained: 3D distribution of atoms over the computational cell has been plotted, proving the possibility of displacement to up to five interatomic distances; the frequency response has been evaluated using the Welch method with a relative RMS error not exceeding 30 %; a graphical dependence between the model and the reference cohesive energy data for a metal HCP cell has been obtained with an error of slightly more than 3 %; an optimal model for piecewise-linear approximation has been calculated, and its 3D interpolation built. All studies performed show good applicability of mathematical simulation to the problems of studying dynamic processes in crystal physics. more...

The results of the samples study of the magnetostrictive-piezo-conductive structure based on Metglas/GaAs/Metglas with different geometric dimensions are presented in this article. The sizes of the studied samples were 10.2x5 2x0.63 mm; 15.2x5.1x0 63 mm; 20.1x5. 2x0.63 mm - with epitaxial layers on a gallium arsenide (GaAs) plate and 15.2x5.1x0.62 mm - without epitaxial layers. The obtained results confirm the initial theoretical calculations of the observation of the maximum magnetoelectric effect in the plane of the GaAs (100) plate with the orientation of the long side of the sample along the crystallographic direction [011]. The maximum αME was observed in a sample with dimensions of 15.2x5.1x0.62 mm without epitaxial layers and was equal to αME = 54.19 V/(cm·Oe) at the resonance frequency RF = 145.8 kHz. In conclusion, the prospects for practical application of a design based on the Metglas/GaAs/Metglas magnetostrictive-piezo-semiconductive structure as a magnetoelectric resistor, a magnetoelectric diode and a magnetoelectric transistor are given. more...

Geochronological tracking has received wide recognition as an appropriate scientific and methodological tool and an effective information technology of qualimetric research in the interests of ensuring high quality of transport services, transportation efficiency, analysis of the facts of insufficient meeting the needs of the population with spatially remote services, etc. On the basis of geochronotracking, a procedure has been developed for statistical verification of research hypotheses about stable trends in changes in the quality of various spatio-temporal processes. The reliability and validity of accepting a particular hypothesis in the framework of a qualimetric research is determined by the representativeness of the volume of initial data on geographical movements, considered as a selection from the general population. This article is devoted to the analysis of this dependence and the development of an algorithm for assessing the specified stability (significance). more...

The paper proposes a method for predicting the service life of high-power laser diodes used in optoelectronic measuring systems which allow adjusting the thermophysical parameters of the diagnosed flow volume in a certain range of their values. The method based on the analysis of the current dependence of the shape of the line enveloping the laser radiation spectrum after 200 hours of their operation. It is shown that for such an analysis the emission spectrum must be considered as a superposition of the emission spectra of single-mode laser diodes. more...

The reaction between succinic anhydride and 2-aminothiazole was carried out in polar organic solvents (acetone, 1,4-dioxane, isopropanol) and in a mechanochemical reactor. By of X-ray phase analysis, IR, 1H, 13C NMR spectroscopy it was found that in both techniques of carrying out the reaction, the only product was succinamide. It was shown that the process efficiency in the mechanochemical reaction conditions is higher in comparison with the traditional solution’s synthesis. The solid-phase interaction development was proceeded during 45 days after load removed, it was especially intense in the first 10 days. more...

Two methodologies for formal concepts derivation are considered: the classical one, which focuses on the posterior analysis of the object’s properties of the studied knowledge domain, and non-classical, the cornerstone of which is the a priori formation of the set of measured object’s properties and the determination of existential relations on this set. In the article, firstly, a position is fixed in the technological chain of the target transformation of the source data, where the difference between considered methodologies shows itself. Secondly, the commonality of these two approaches is established in the aspect of the unity of their hypothetical-deductive basis. In this case, the cognitive activity of the subject is expressed first in a priori and then in a posteriori conceptual scaling of the measured properties. The work demonstrates the need for the joint use of the considered methodologies at processing incomplete and inconsistent empirical data about studied knowledge domain. The intermediate consolidation of these methodologies is possible only on the basis of multi-valued logic. more...

A solid fuel combustion chamber of the Helmholtz-resonator-type is investigated. In previous works, the air supply tube and the combustion product outlet tube were open at the outlet. In this paper, we consider a device in which the tubes are connected by a total volume. The linearization of the conservation equations in the combustion chamber and the interference chamber gives four boundary conditions for acoustic disturbances. From these conditions, an equation follows that allows us to calculate the frequencies of gas vibrations in the device of the considered type. more...

The work is aimed at identifying the most effective methodology for short-term forecasting of energy consumption concerning intervals of 1 hour to 1 week based on the employment of im-proved fuzzy recurrence and long short-term memory neural networks. The object of research is a residential area with an uneven consumption of electrical energy. The article discusses methods for forecasting electrical load on the example of a residential area. The existing methods of forecasting were analyzed and the day-ahead and intra-day power forecast were reviewed. The list of relevant sources was presented. On the basis of the reviewed literature in this area, the most effective and modern methods were identified that allow determining the consumption of electrical loads in residential and industrial buildings with an accuracy of 98 percent. Tables were developed reflecting the effectiveness of the considered techniques. The time horizons of the forecast of electric energy consumption are considered. Four categories of load forecasting were identified: long-term forecasting with a forecast interval of more than one year; medium-term forecasting with a forecast interval from one month to one year; short-term load forecasting with a forecast interval from 1 day to several weeks.; operational forecasting, with a forecast interval from 1-2 hours to the end of the day. A comparative analysis of methods for predicting electrical load for intelligent network applications is carried out and its results are presented. more...

The tools for determining the forecast value of the costs associated with creating new measuring tools that have standardized metrological characteristics are proposed. It is adapted to the cost estimation procedures carried out to develop a plan for their production in both monopolistic and competitive markets. Existing models for optimizing these procedures cannot always be applied since, due to the considerable complexity of the simulated process, they are often illustrative in nature. Some procedures are not formalized and do not consider the required extent of their application’s specifics on a competitive basis. Therefore, when predicting costs in creating new measuring tools, it is sometimes necessary to use analogies and expert evaluations. This circumstance reduces the validity of forecast estimates. In contrast to existing methods of solving the problem under consideration, the proposed toolkit allows solving it systematically and based on formalized procedures. The article presents a model statement of this problem’s solution using a system of criteria and indicators for the quantitative assessment of the processes under consideration. The proposed toolkit is based on the methodology of structural synthesis of cost forecasting procedures. The use of the proposed toolkit will increase the validity of the forecast values of the costs associated with the creation of measuring tools. This will ensure the optimality growth of production plans for new measuring tools used in metrology. One of the possible solutions to this problem is presented in the article. more...

The article discusses the development of a system for recognizing people at a pedestrian crossing. The recognition system includes a trained classifier and two sets of images taken from an open database containing images of city streets from outdoor cameras. Input information prepared using PictureCropper application. The classifier was tested based on the prepared sets of images. The result is shown in the figure, and after testing, the metrics were calculated, necessary to assess the effectiveness of the resulting classifier for each set. System is being developed for specialists, which will allow individual and centralized adjustment of the adjustment of pedestrian phases for each road situation, both for the local system of controllers, and in accordance with the existing algorithms of coordination systems with the expansion of such. more...

The morphology of the relief of nanosized titanium films on the mica surface was studied using a scanning probe microscope at various scales. The characteristic features of the nanorelief of the surface of the investigated films, including fractal properties, are described. The obtained data on the fractal dimension are compared with the available experimental data, as well as the data obtained using scanning tunneling microscopy. Recommendations for the development of technology for «growing» structures with a given surface morphology are proposed. more...