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ABSTRACTThe purpose of the article is to analyse the manufacturing factors that affect the cost of manufacturing a part. Nowadays the cost of equipment used for metal 3D printing, as well as metal powders, are still very expensive. The cost of additive manufacturing of metal parts is mainly dependent on the volume of printing, therefore, reducing the volume of printing can lead to a significant reduction in the cost of manufacturing the part. Manufacturing of a metal shell, the cavity of which is filled with a cheap metal polymer, can be an excellent alternative to an all-metal part. The article provides a method for calculating the cost of manufacturing a lever part using various technologies: subtractive, additive, and composite part manufacturing technology. According to the calculated data, the dependence of the cost of manufacturing a part on piece time has been built, which can be interpreted as the amount of machining. The constructed linear dependence can give an idea of the effectiveness of the application of a particular technology for obtaining a part. In addition, non-economic factors affecting the possibility of using various technological processes for manufacturing a part are described.

2020 witnessed significant changes in the policies, activities and the plans on the level of governments and companies as well as individuals. While the COVID-19 pandemic exposed the increasing threats and weaknesses, it allowed for new opportunities. New proper measures must be taken to increase cybersecurity, especially that impact of the pandemic is going to have long-term ripples and effects. In this article, the structure of indicators included in the calculation of the National Cyber Security Index is studied and the distribution of the National Cyber Security Index across income groups analysed. In addition to that, the assessment of the efficiency of using resources to ensure national cybersecurity and studies of the impact of COVID-19 on the level of national cybersecurity displayed. Finally, recommendations are giving to improve cybersecurity during and after a pandemic.

Digital agriculture requires development and implementation of new information and communication technologies including wireless ones for increasing efficiency. The authors developed wireless sensor networks and wireless technology for express-diagnostics of plant state in agriculture, and created the appropriate hardware, software and methodological support. The developed networks now are implemented and under field tests both in open agricultural lands and in smart greenhouses. In this paper the design and application of developed wireless sensor network and some results of calculations and modelling are given.

The use of metal-polymers in the manufacture of mold-forming parts allows for the significant reduction in price and time used in manufacturing of parts. Using data on the thermal conductivity of metal-polymers in calculations of the cooling system of molds allows calculating the optimal cycle of obtaining the product. The authors propose a method of determining the coefficient of heat transfer of metal-polymers based on a die matrix, filled with aluminum. The chosen equipment or measuring tool by them, allows determining the heat transfer coefficient of the material in use. The values of the coefficient of heat transfer of the material in question, obtained in the course of the research can be use in different databases of applications used for modeling production by injection molding. The described method of determining the coefficient of heat transfer may be repeated for samples of metal-polymers.

For a given nonrepeating function f(x1, ... , xn) that essentially depends on all its variables we estimate the length of the diagnostic test on the set of all nonrepeating functions arbitrarily dependent on the variables x1, ... , xn. Previously the author has shown that the corresponding Shannon function is of order θ(n2). In this article nonrepeating functions f(x1, ... , xn) are constructed for which the length of the minimal test increases superlinearly but not faster than n2/2.

In order to increase the service life of machines the life of their parts should be increased. For example, in machine tool and lifting-and-transport manufacture the maintenance cost of the equipment over the duration of its operation often exceeds the cost of the new equipment by a factor of 10–20. This imposes strict requirements on structural materials for heavily loaded gearings, including the development of high-strength, wear-resistant, manufacture-adaptable, and economically alloyed steels.

A roll is the basic rolling tool whose stability determines the technical and economical parameters of operation of rolling mills and the time of their continuous operation between replacements of the rolls, their output, the stability of operation, the quality and cost of products, the loss to rejects, and the specific consumption of the roll material. Despite the ample investigations, the problem of increasing the endurance of roll steels and creating high-quality working and backup rolls is still urgent, because its solution will save expensive roll tools. This is a complex problem because the durability of rolls depends on a great number of metallurgical, design, technological, and operational parameters.

The isomers of 1-benzoyl-2,5-dimethyl-4-piperidone were obtained and equilibrated (89.8% cis ? 10.2% trans isomer, preferred conformations 2a, 5e, and 2a, 5a). The position of the equilibrium between the isomers of 2,5-dimethyl-4-piperidone was determined by two independent methods (89.5% trans ? 10.5% cis isomer). The differences in the free energies of the isomers, the conformational energy of the ?-CH3 group, and the energy of syn-axial 1,3-interaction between the CH and the unshared electron pair were calculated; the decrease in the conformational energy of the ?-methyl group in the series of piperidine (1.6), 4-piperidone (1.47), and N-acyl-4-piperidone (1.28 kcal/mole) was explained by the successive weakening of the repulsive interaction between the ?-CH3 group and the n-pair of the nitrogen as a result of the flattening of the ring and of the conjugation between the free electron pair of the nitrogen and the p electrons of the acyl carbonyl group. The last previously unknown fourth isomer of 2,5-dimethyl-4-piperidol, which exists in the 2e,4a,5a conformation, was obtained by the reduction of cis-1-benzoyl-2,5-dimethyl-4-piperidone followed by debenzoylation. In contrast to the secondary amine, its N-benzoyl- and N-benzyl-substituted derivatives exist in the alternative 2a,4e,5e conformation. The configurations and conformations of the isomers were determined by means of the IR and NMR spectra.

Reduction of 1-benzoyl-2a-methyl-4-oxo-cis-decahydroquinoline with sodium borohydride and sodium in alcohol has given 1-benzoyl-2a-methyl-4?-hydroxy-cis-decahydroquinoline, which exists in the steroidal conformation with diaxial a, a'-substituents in the piperidine ring and with an equatorial hydroxy-group. Debenzoylation of this has given the last of the eight theoretically possible isomers of 2-methyl-4-hydroxydecahydroquinoline, namely 2a-methyl-4?-hydroxy-cis-decahydroquinoline, which exists in the nonsteroidal conformation with an axial hydroxy-group.

Epimeric (with respect to the methyl group) stereoisomers of 4-keto-2-methyl-1-chloro-trans-decahydroquinoline were obtained, and their transformations under the influence of triethylamine were investigated. It was shown that the direction of the transformations depends on the steric orientation of the methyl group and the molar ratio of the N-chloroamine and triethylamine. The N-chloroamine isomer with an equatorial methyl group undergoes dehydrochlorination in the presence of excess triethylamine to give 2-methyl-4-hydroxy-trans-5,6,7,8,9,10-hexahydroquinoline. With an equimolar amount of triethylamine in solution in CCl4 the principal reaction pathway becomes dehydrochlorination and subsequent chlorination to give 2-methyl-4-hydroxy-3-chloro-trans-5,6,7,8,9,10-hexahydroquinoline. The N-chloroamine isomer with an axial methyl group in the presence of both excess and, in particular, equimolar amounts of triethylamine undergoes, in addition to dehydrochlorination and chlorination in the ß position of the piperidine ring, cis-trans isomerization and subsequent dehydrogenation with the primary formation of 2-methyl-4-hydroxy-3-chloro-5,6,7,8-tetrahydroquinoline. The mechanism of the transformations is examined.

We present a theoretical and experimental investigation of Bragg scattering of surface magnetostatic waves (SMSW) by a time-independent, spatially periodic magnetic field when the wave orientation is arbitrary with respect to the magnetization field. In the theoretical section the theory of single-mode Bragg diffraction is generalized to the case of waves with arbitrary dispersion propagating through an anisotropic medium. The calculated results are, on the whole, supported by experimental measurements on SMSW. We demonstrate that a geometry which in isotropic media leads to a sinusoidal distribution of diffraction order amplitudes as a function of penetration into the differing lattice, can lead to a nearly exponential distribution of such amplitudes in anisotropic media. The anisotropy of the interaction between SMSW and the magnetic diffracting lattice is manifested by anomalously high scattering efficiencies for certain cases of relative orientation.

The phenomenon of acoustic emission can be used in studying the characteristic features of the mechanism, kinetics, and energy parameters of the martensitic transformation: determination of the martensite points and the amount of martensite that is formed, measurement of the rate of initiation and growth of martensite crystals, investigation of preliminary processes, establishment of the incubation period and the early stages of the formation of martensite, determination of the type of kinetics, structural mechanism, and morphology of the martensite that is formed, and the formation and annihilation of transformation twins, and determination of the degree of cooperativeness of the transformation, the presence and degree of the autocatalysis effect, and the heterogeneity of the shear strain during the transformation. The possibility of AE development during certain diffusion transformations requires confirmation. A more profound and objective investigation of the AE effect (among other things, a detailed study of the mechanism governing the development of AE signals and the identification of their sources), further improvement and standardization of the methods and equipment used are necessary.

Austenitic nickel cast irons (ANCI) are promising materials, which can be used in many sectors of the national economu. In our country, however, its production is complicated by a scarcity of pure charge materials, inadequate development of precision technology for the smelting, modification, and fabrication of quality castings of complex configuration, welding, hardening facings, and machining. When the chromium content is low, moreover, the ANCI are incapable of passivation and are insufficiently stable in certain aggressive media at elevated tempertures and stresses.

It is shown that epimeric [with respect to the C(2) atom] 1-chloro-2-methyl-4-keto-trans-decahydroquinolines in an acidic medium undergo intermolecular monochlorination in the a position relatve to the carbonyl group with the formation of epimeric [with respect to the C(2) atom] 3e-chloro- and 10a-chloro-2-methyl-4-keto-trans-decahydroquinolines and 2-methyl-4-keto-10-chloro-cis-decahydroquinolines. The mechanism of the transformations is examined, and an assumption regarding the possibility of cis-trans isomerization of the intermediately formed p-chloronium complex is expressed.

Using the relationship between the sizes of particles and the characteristics of their layer, we obtain the dependence of the mass-transfer coefficient on time and concentration; the dependence is included in the third-kind boundary condition. Using this condition, we solve the boundary-value problem of extraction.

1.A relationship was found between phase transformations and chemical microheterogeneity of the solid solution in steels 1Kh15N5AM3 and 1Kh16N4AB.2.It was confirmed that d ferrite can exist in equilibrium and nonequilibrium conditions in these steels.3.The amount of d ferrite can be controlled by changing the holding time.

In this poster we present the use of the SPIRAL system (www.spiral.net) to generate code for modular Fast Fourier Transforms (FFTs). SPIRAL is a library generation system that automatically generates platform-tuned implementations of digital signal processing algorithms with an emphasis on fast transforms. Currently, SPRIAL can generate highly optimized fixed point and floating-point FFTs for a variety of platforms including vectorization, multi-threaded and distributed memory parallelization. The code produced is competitive with the best available code for these platforms and SPIRAL is used by Intel for its IPP (Intel Performance Primitives) and MKL (Math kernel Library) libraries. The SPIRAL system uses a mathematical framework for representing and deriving algorithms. Algorithms are derived using rewrite rules and additional rules are used to symbolically manipulate algorithms into forms that take advantage of the underlying hardware. A search engine with a feedback loop is used to tune implementations to particular platforms. New transforms are added by introducing new symbols and their definition and new algorithms can be generated by adding new rules. We extended SPIRAL to generate algorithms for FFT computation over finite fields. This addition required adding a new data type, several new rules and a new transform (ModDFT) definition. In addition, the unparser (where code is generated) was extended so that it can generate scalar and vectorized code for modular arithmetic. With these enhancements, the SPRIAL machinery can be applied to modular transforms that are of interest to the computer algebra community. This provides a framework for systematically optimizing these transforms, utilizing vector and parallel computation, and for automatically tuning them to different platforms. In this poster we present preliminary results from this exploration. We show that the code generated by SPIRAL, with improved cache locality and vectorization, is approximately ten times faster than the modular FFT code in the modpn library.

Preliminary heat treatment has a substantial effect on the kinetics of the a?? transformation, the amount of retained austenite, the grain size, and the work of crack propagation in steel Kh15N2D2T after final heat treatment.

The impact toughness of steel 4Kh4M1V3F can be improved by increasing the cooling rate during quenching, which prevents the bainitic transformation and precipitation of carbide phase during cooling.