41 Works

ALGORITHM FOR POSITIONING OF ROTARY ACTUATORS BASED ON SHAPE MEMORY Cu-Al-Ni TENSILE FORCE ELEMENTS

A. Priadko, S. Pulnev, O. Kovalev & I. Ilin
This paper considers positioning algorithms for rotary actuators based on shape memory Cu-Al-Ni crystals. The actuator function scheme is provided. An algorithm for positioning of the actuator based on an actual rotary angle has been developed. Experimental results on the control algorithm and the actuator are presented. The functional characteristics of the actuator (rotation speed and positioning accuracy) are considered.

SIMULATION OF INVERSE HALL-PETCH RELATION IN NANOCRYSTALLINE CERAMICS BY DISCRETE DISLOCATION DYNAMICS METHOD

S.V. Bobylev
A theoretical model of plastic deformation of nanocrystalline ceramics in the region of small grain sizes is proposed. In the framework of the model, deformation is described as the combined action of grain boundary sliding and emission of lattice dislocations from triple junctions of grain boundaries. Using the method of discrete dislocation dynamics we obtained an inverse Hall-Petch relation, which qualitatively coincides with the experimentally measured dependences of microhardness in nanocrystalline ceramics with extremely small...

Forensic Studies of Trace Evidence Altered by Fire

Igor Latyshov, Mikhail Pakhomov & Natalia Anosova
When investigating crimes involving fire, it is necessary to assess the event of a crime and the circumstances and to find the causes and spread of the fire, and the possible evidence supporting that the fire was used as a means of concealing a previously committed crime, i.e. murder, burglary, etc. Forensic studies of the objects damaged by the fire require the knowledge of theoretical aspects and the ability to detect and evaluate changed patterns...

CLUSTERING OF TERRITORIAL OBJECTS IN THE MANAGEMENT OF THEIR SUSTAINABLE DEVELOPMENT

Dmitrii Rodionov, Dmitry Alferev, Yuliya Klimova & Kaisar Serikuly Alpysbayev

SUSTAINABLE DEVELOPMENT AND ENGINEERING ECONOMICS

Irina Rudskaia, Dmitrii Rodionov, Tatiana Kudryavtseva & Angi Skhvediani

BALANCE SCOREBOARD FOR SUSTAINABLE DEVELOPMENT IN THE RUSSIAN ARCTIC ZONE

Svetlana Gutman

DEVELOPMENT OF A SYSTEM-SYNERGETIC APPROACH TO COST MANAGEMENT FOR A HIGH-TECH INDUSTRIAL ENTERPRISE

Ekaterina Burova, Sergei Grishunin & Svetlana Suloeva

NUCLEAR GEOMETRY: SODIUM, MAGNESIUM, ALUMINUM

Alexander I. Melker
The nuclear geometry has been developed by analogy with the fullerene geometry. On the basis of this geometric approach, it was possible to design the structure of sodium, magnesium and aluminum isomers and their isotopes, which can be obtained by means of nuclear synthesis. The most stable nuclei can be classed into two groups: basic nuclei having equal number of protons and neutrons and isotopes having one or two more neutrons. The latter ensure their...

Effect of Design on the Evacuation Time for the Colosseum of Rome

Marina Gravit, Ekaterina Kirik & Egor Savchenko

Technologies and Media Environment of Information Society

Olga Shipunova
The specificity of the social life-world during the digital era is defined by the dynamics of the multimedia environment where the permanent reproduction of virtual interactions and smart-technologies gives rise to the problem of cognitive orientation in the field of information. Models of personal identification with a new perspective of cyber-anthropology are based on principles for the creation of a multiagent system immersed in the infosphere of the outside world. In this issue we highlight...

Messengers and Chats – Technologies of Learning

Daria Bylieva & Laurent Moccozet
Technology-mediated communication has expanded the possibilities of communicative support of the educational process. Even 10 years ago, students used communication for social and entertainment purposes, but today e-communication related to education is widespread. This research is based on a qualitative analysis of the content of the peer-discussion and survey of Swiss and Russian students (N=1069). Peer-communication serves many purposes, from clarifying work/duty and sharing useful information to collaborative activity. When a student faces a problem...

Non-Verbal Marketing Research Techniques in Education

Marianna Ababkova
The purpose of marketing research in education is to get information about the consumers of educational services and to discover appropriate strategies for tailoring the marketing strategy of an educational organization. Building on previous work regarding “Mental Maps as a Creative Tool of Marketing Analysis in Education,” this paper considers the task of qualitative and quantitative marketing research that aims at identifying significant market features of an educational organization and increasing the potential of its...

Crystallographic texture of industrial automotive steels and effect of tertiary cementite dissolution on its development

Alexander A. Vasilyev, N.Y. Zolotorevsky, Dmitry F. Sokolov & S.A. Philippov
X-ray investigation of crystallographic texture and its correlation with r m value (Lankford coefficient) was performed on a representative set of industrial automotive steels of different grades. Though the majority of steels had the structure of polygonal ferrite with small fractions of pearlite in the hot rolled condition, steels with a more complex structure were also included in the study. For this set of steels, a linear dependency has been shown to hold between r...

Experimental study and modeling of changing mechanical properties in tempering of bainitic-martensitic steels

A.A. Vasilyev , D.F. Sokolov & S.F. Sokolov
Dependences of mechanical properties (yield stress, tensile stress, relative elongation) and impact toughness on the tempering time at various temperatures have been investigated for 10 industrial bainitic-martensitic steels with a wide range of chemical compositions (C(0.04-0.27), Mn(0.33-1.57), Si(0.22-1.09), Cr(0.02-1.14), Ni(0.01-3.74), Cu(0.02-1.03), Mo(0.01-0.43), Nb(0.002-0.044), V(0.003-0.200), Ti(0.001-0.045), B(≤0.003) (mass.%)). Based on the obtained experimental results, a quantitative model is developed to predict the mechanical properties of the considered steels after tempering. The modeling results comply well with...

Frequency-Dependent Dynamic Characteristics of the Soil Foundation

Aleksey Shokin & Daniil Semenov

Migration of nonequilibrium grain boundaries in metal-graphene composites with ultrafine-grained matrix

S.V. Bobylev
We propose a theoretical model describing stress-induced migration of nonequilibrium grain boundaries constrained by the presence of second phase inclusions in metal-graphene composites with the ultrafine-grained matrix. Within the framework of the model, the structure of nonequilibrium boundaries is represented as a combination of dislocation structure of equilibrium boundary and dislocations introduced from outside, trapped by the boundary during deformation. Using the disclination theory approach, a change in the energy of the system associated with...

NUCLEATION AND GROWTH OF FULLERENES AND NANOTUBES HAVING FOUR-FOLD SYMMETRY

Alexander I. Melker, Maria A. Krupina & Aleksandra N. Matvienko
We have studied possible ways of generating and growing the fullerenes having four-fold symmetry. Beginning with cyclobutane C4H8 and clusters C8, we obtained elementary fullerenes C8 and mini-fullerenes C16, which produce the following fullerenes from C24 to C64, perfect (basic) and imperfect, as well as nanotubes. The imperfection is connected either with extra 'interstitial' or 'vacancy' carbon dimers, both types of dimers playing the role of defects. Only the basic fullerenes C24, C32, C40, C48,...

The mechanical properties improvement of thermoplastics-based fiber metal laminates

Dmitry Goncharenko, Ilya Kobykhno, Elizaveta Bobrynina & Oleg Tolochko
This study investigated the possibility of increasing the fiber metal laminates mechanical properties by improving the impregnation quality due to the addition of a different number of layers of polymer film on the prepreg-metal interface. Specimens were made based on two thermoplastic polymers (polyamide-6 and polypropylene), glass fibers (E-glass), and aluminum alloy (AlMg6) by hot pressing. The theoretical calculation was performed for the tensile strength according to the rule of mixtures. The dependences of tensile...

Modeling of carbides and copper particles precipitation during tempering of bainitic-martensitic Cr-Mo-V-Cu steels

A.A. Vasilyev, S.F. Sokolov & D.F. Sokolov
The paper represents a model for the tempering effects on quenched bainitic-martensitic steels that describes both the recovery and precipitation phenomena. The latter involves various carbides (Fe3C, V4C3, Mo2C, Cr7C3) and particles of pure Cu. Thermodynamic driving forces in the nucleation of the considered particles have been calculated using empirical formulas obtained with the Thermo-Calc software. The predicted formation kinetics for the considered carbides and Cu particles complies well with relevant experimental data.

Emojis as a Language of their Own

Dmitriy Agranovskiy & Alina Avilova
Emojis are a product of computer mediated communication. As a means of expressing emotion, indicating the illocutionary force or the intended tone, they are well-researched. However, emojis are rarely seen as a visual language in their own right. The article analyzes the syntax and semantics semantics of emojis and people’s ability to interpret them. The research method for this article was an online survey. An emoji rendering of the title of a literary work was...

Teaching English as a Language for Mechanical Engineering

Eduard Krylov, Liudmila Khalyapina & Alfred Nordmann
Engineering education usually includes the acquisition of a foreign language for a transnational professional discourse. Engineering education also involves the acquisition of competencies to compose functional technical systems from component parts. This paper provides a conceptual and empirical exploration of a synergistic effect between these two learning processes. It proposes that engineering education draw upon and incorporates this synergy. A pilot training course confirms that this leads to a faster development of the overall engineering...

Deformation mechanism of bimodal metal-graphene composites with nanotwinned structure

N.V. Skiba
The theoretical model is suggested which describes micromechanisms of plastic deformation in bimodal metal-graphene composite consisting of large grains embedded into nanocrystalline/ultrafine-grained metal-matrix reinforced by graphene inclusions. In the framework of the model, lattice dislocation slip and grain boundary sliding has occurred in nanocrystalline/ultrafine-grained matrix, and lattice dislocation slip and migration of twin boundaries are realized in large grains with a nanotwinned structure providing the plastic deformation of bimodal metal-graphene composite. With this assumption, the...

Исследование структуры и элементного состава поверхности металла после финишного плазменного упрочнения

Павел Абрамович Тополянский, Сергей Александрович Ермаков & Андрей Павлович Тополянский
Рассмотрена актуальность изучения структуры и элементного состава тонкопленочных покрытий для прогнозирования эффективности повышения долговечности деталей. Приведены известные механизмы упрочнения металла при создании антифрикционных материалов, обеспечивающих минимальные коэффициент трения, длительность приработки, тепловыделение при трении и параметры износа, и дисперсионно-упрочненных наночастицами материалов, повышающих прочностные характеристики. Рассмотрены отдельные аспекты технологии финишного плазменного упрочнения путем нанесения покрытий на финишной стадии изготовления деталей при их температуре нагрева менее 150 °С и неизменности исходных параметров шероховатости. Результаты растровой электронной микроскопии подтвердили...

Effect of the specimen size on necking development in metals and alloys during superplastic deformation

A.G. Sheinerman
A model is proposed that describes the development of individual and multiple necks in superplastically deformed materials. Within the model, the examined samples have the form of round bars and are subjected to tensile superplastic deformation without strain hardening. It is demonstrated that neck development and necking-induced failure occur faster with a decrease in strain rate sensitivity and/or an increase in the fraction of the sample length occupied by necks. This means that high values...

NUCLEAR GEOMETRY: FROM NITROGEN TO NEON

Alexander I. Melker
The nuclear geometry was developed by analogy with the fullerene geometry. On the basis of this geometric approach, it was possible to design the structure of nitrogen, oxygen, fluorine and neon isomers and their isotopes, which can be obtained by means of nuclear synthesis. The most stable nuclei can be classed into two groups: basic nuclei having equal number of protons and neutrons and isotopes having one or two more neutrons. The latter ensure their...

Registration Year

  • 2021
    41

Resource Types

  • Text
    41

Affiliations

  • Peter the Great St. Petersburg Polytechnic University
    41
  • St Petersburg University
    2
  • Institute of Problems of Mechanical Engineering
    2
  • TU Darmstadt
    2
  • Volgograd Academy of the Russian Internal Affairs Ministry
    1
  • Graz University of Technology
    1
  • Saint Petersburg Mining University
    1
  • Izhevsk State Technical University
    1
  • Satbayev University
    1
  • Charles University
    1