War Veteran and Academician (The centenary of academician K.S. Kolesnikov)

The article presents brief information on the main stages of the life and work of academician Konstantin Sergeyevich Kolesnikov, and his scientific and educational school created at Bauman Moscow Higher Technical School (BMHTS) to study dynamics and strength of machines and teach mechanics.

International Economic Forum as a Platform for Gaining Experience and Reinforcing Communication Skills

The paper discusses current trends in the Russian labor market. The question of the importance of communication and self-presentation skills for a modern young engineer is highlighted. The paper provides a definition of the engineering elite as universal specialists capable of solving diverse problems. An important component of the education of the elite is the stressful situation simulation for the development of skills for solving extraordinary tasks and teamwork. A visit to the forum is an important component of the training, in which students learn to apply the learned skills in practice to consolidate them and broaden outlook. The necessity of attending high-level public events for students striving for self-realization not only as specialists, but also as an educated person, is shown.

Member of the War and Academician (on the Centenary of the Birth of Academician K.S. Kolesnikov)

The article provides brief information about the main stages of the life and work of Academician Konstantin Sergeyevich Kolesnikov and the scientific and pedagogical school he created in the field of studying the dynamics and strength of machines, teaching mechanics at Bauman Moscow State Technical University.

Investigation of Additional Mass Effect on Dynamic Wing Model Stability in Airflow

The paper investigates a dynamic stability of the wing model in the flow of incoming air. As is known, at a certain flow rate, called critical, there occurs a phenomenon of self-excited non-damping flexural-and-torsional self-vibrations, called flutters. The paper considers an anti-flutter approach that is the placement of additional weight on the elastic elements (springs) in the wing model. Thus, a three-stage wing model is under consideration while the publications concerning this problem more often describe a two-stage wing model. The paper is a natural sequel to the authors’ first paper [9] where a two-stage wing model was considered in detail. It continues and develops research in this area, conducted by many famous scientists, such as V.L. Biderman, S.P. Strelkov, Ya.G. Panovko, I.I. Gubanova, E.P. Grossman, J.C. Fyn and many others who have investigated this phenomenon. It is also necessary to mention the scientists, namely Keldysh M.V., Reese P.M., Parkhomovsky Y. M., etc. who not only studied this phenomenon, but developed anti-flutter methods for it.It should be noted that not only scientists-theoreticians, but also test pilots, in particular M.L. Gallay [8], contributed to the solution of the flutter problem. The paper describes in detail a derivation of the linear differential equations of small vibrations of a wing model with additional weight in the flow, determines the eigenfrequencies and forms of flexural-and-torsional vibrations, checks their orthogonality, explores the forced vibrations under aerodynamic force and moment, and estimates a critical flow rate for a number of system parameters, namely a mass of the additional weight and the rigidity of its suspension. The conclusion is drawn that these parameters effect on the critical rate. Based on the calculation results, one can come to the conclusion on the additional weight effect on the critical flutter speed and on how relevant the anti-flutter method is. The given paper may be of interest both for students of technical specialties who learn the theory of mechanical vibrations, and for engineers majoring in aero-elasticity and dynamic stability of the elements of mechanical systems.

Study of Bismuth Telluride Crystal Strength

The article presents results of strength tests of bismuth telluride prismatic samples obtained by growing crystals. These crystals have semiconductor properties and are used in the heat machines, the run-ability of which largely depends on the strength of crystals. Data available in the literature are significantly different from each other. It has been shown that, the most consistent strength tests results are obtained in case of bend testing. The measurement results of the elasticity modulus and tensile strength are given. For tests, an INSTRON testing machine with maximum direct stress of the 1000 H was used.

Designing Desorber for MEA Regeneration after Associated Petroleum Gas Treatment. Part 2

The paper presents a desorption-based method for treating a waste mono-ethanolamine (MEA) solution to extract hydrogen sulfide. The process is used in the associated petroleum gas (APG) treatment unit to remove hydrogen sulphide together with the MEA solution process of hydrogen sulfide absorption from the APG that comes from the well. Extracted hydrogen sulfide can be used to obtain elemental sulfur. The object of development is a stripper for APG treating to remove hydrogen sulfide.Such a treating system is, as a rule, unavailable separately from the absorber and represents an integrated system to treat APG from hydrogen sulfide. Thus, the work objective was to determine parameters, and develop and design desorption column where mono-ethanolamine purification from hydrogen sulphide occurs.The paper presents calculation of desorption column that allows us to close the treatment process, thereby ensuring the regeneration of the mono-ethanolamine solution through treatment by the desorption process. The waste amine is returned to the gas treatment process, and the extracted hydrogen sulfide goes to the Claus process for elemental sulphur production. The column calculation was performed taking into account chemical and thermal processes. The APG treatment unit option to extract hydrogen sulfide with further elemental sulfur produced through the Claus process has been obtained to solve this problem by using the APG as an industrial and domestic gas.

Modified Method of State Variables

Formal mathematical model development of an object with lumped parameters is an integral part of CAE systems. The computer-aided design (CAD) system functionality largely depends on the formation method used. The article proposes to modify a method of state variables, which is a pioneer in formal mathematical models development of technical objects whose behaviour is described by a system of ordinary differential equations.The classical method of state variables uses a graph-based representation of the object structure and allows development of its mathematical model in the normal Cauchy form without incorrect locations. The incorrect locations mean situations when capacitance-type branches fall in the graph chords or inductance-type branches fall in the graph tree branches. If there are incorrect locations in the object’s scheme then, to have a model of correct development, additional elements are included to eliminate them. Such an approach is possible if the object description is performed at the level of the basic two-poles, but it is assumed that in all modern CAD systems there is a pre-processor in which it is possible (and as a rule) to use multi-pole components. In this case, it is challenging for an unsophisticated user to make scheme correction.The modified method of state variables proposed in the article is free from this drawback and allows us to obtain a mathematical model in the normal Cauchy form and with incorrect locations available. This will allow us to use both explicit and implicit integration methods, conduct modal analysis, and simply have a model version in the FMI standard.

Domestic Engineering - Industry 4.0 Technology Transition Problems

The paper deals with problem analysis due to domestic engineering transition to the Industry 4.0 technology. It presents such innovative technologies as additive manufacturing (3D-printing), Industrial Internet of Things, total digitization of manufacturing (digital description of products and processes, virtual and augmented reality). Among the main highlighted problems the authors include a lack of unification and standardization at this stage of technology development; incompleteness of both domestic and international regulatory framework; shortage of qualified personnel.

Absorption-based Mono-ethanolamine Treatment of Associated Petroleum Gas. Part 1

The paper presents an absorption-based method to treat associated petroleum gas (APG) using the mono-ethanolamine (MEA) as an absorbent. Involving oiler’s specific data in the southern regions of Russia, an APG treating unit has been developed to take out hydrogen sulfide. The extracted hydrogen sulfide can be used to obtain elemental sulfur. The development object is a treating APG unit.The work objective was to develop an absorber for APG treating to take out hydrogen sulfide by means of regenerated MEA aqueous solution. The work was aimed at reducing environmental pollution when using associated petroleum gas as an energy utility.A plate-shaped absorber model was used. In this design, the liquid enters the upper plate, moves horizontally along the plates, from the overflow from the overlying one towards the overflow to the underlying one, and outlets through the lower part of the absorber.The paper offers an option of the unit for APG treating for removing hydrogen sulfide with the elemental sulfur further produced by the Claus process to solve this problem through using APG as an industrial and domestic gas.The work has involved a complete calculation of the two-component absorption process, a design calculation of the plate-shaped absorber, in particular, determination of the cowl wall thickness, a fitting selection, a calculation of the foundation bolts taking into account the wind load on the absorption column, a rationale for the option chosen, and a calculation of the complete desorption process.In entering the desorber, the absorbent undergoes a single liquid and vapour phase evaporation. To calculate a mole fraction of the stripping initial absorbent, as well as phase compositions, is used a Tregubov method.

Bots Recognition in Social Networks Using the Random Forest Algorithm

Online social networks are of essence, as a tool for communication, for millions of people in their real world. However, online social networks also serve an arena of information war. One tool for infowar is bots, which are thought of as software designed to simulate the real user’s behaviour in online social networks.The paper objective is to develop a model for recognition of bots in online social networks. To develop this model, a machine-learning algorithm “Random Forest” was used. Since implementation of machine-learning algorithms requires the maximum data amount, the Twitter online social network was used to solve the problem of bot recognition. This online social network is regularly used in many studies on the recognition of bots.For learning and testing the Random Forest algorithm, a Twitter account dataset was used, which involved above 3,000 users and over 6,000 bots. While learning and testing the Random Forest algorithm, the optimal hyper-parameters of the algorithm were determined at which the highest value of the F1 metric was reached. As a programming language that allowed the above actions to be implemented, was chosen Python, which is frequently used in solving problems related to machine learning.To compare the developed model with the other authors’ models, testing was based on the two Twitter account datasets, which involved as many as half of bots and half of real users. As a result of testing on these datasets, F1-metrics of 0.973 and 0.923 were obtained. The obtained F1-metric values are quite high as compared with the papers of other authors.As a result, in this paper a model of high accuracy rates was obtained that can recognize bots in the Twitter online social network.