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The concept of multi-energy systems (MES) is widely applied in various areas of energy supply. This approach makes it possible to analyze the distribution of energy flows and their mutual influence both for local facilities and for power supply systems. At the same time, currently, promising systems for analysis, forecast, and control of the behavior of energy facilities are those that employ innovative methods, for example, different technologies of mathematical modeling. Their successful application requires a methodological approach to build mathematical models of integrated energy systems relying on simulation modeling. The approach proposed in this paper is based on the concept of an energy hub. It has been tested on a simulation model for two energy supply channels for a fragment of a real-world energy facility. The presented methodological approach to create mathematical models of integrated energy systems is based on simulation. This approach offers broad prospects for expanding the capabilities in the design and operation of integrated multi-energy systems.

Supplementary audiovisual material: https://youtu.be/K-EE9YY6pHY https://youtu.be/gRpxQOx9ugs In the Late Mesolithic graves of Yuzhniy Oleniy Ostrov, Northwest Russia, large amounts of Eurasian elk (Alces alces) incisors have been found. These teeth, for the most part fashioned into portable pendants, seem to have formed decorative sets for the garments or accessories of the deceased. This article examines both the technologies associated with these artefacts and their uses, as well as reflecting on the sensorial experiences generated by them. Osteological analysis of a sample of 100 specimens indicates that all types of incisors were used for making the pendants. Traceological analysis indicates that the teeth were modified by scraping, grooving, grinding, and retouching. Traces of wear consist of general wear and distinctive pits or pecks on the perimeters of the crowns. These traces indicate that the pendants were worn before their deposition in the graves, in such a way that they were in contact with both soft and solid materials. The pattern of pits or pecks has until now been unreported in the traceological literature. In experiments, a similar pattern emerged when pendants of fresh elk incisors were hung in rows and bunches and struck against one another. These strokes created a rattling sound. Thus, the elk incisors of Yuzhniy Oleniy Ostrov appear to provide insight into previously unattainable sonic experiences and activities of Mesolithic hunter-gatherers, as well as the early history of the instrument category of rattles.

Integrated multi-carrier energy systems give good possibilities to have high effectiveness of energy supply to consumers. Transformation of energy systems under the impact of internal and external factors remarkably strengthens the technological integration of those systems and supports development of integrated multi-carrier energy systems. The concept of energy hub is developed for modeling and simulation of integrated multi-carrier energy systems. Based on previous research, a simulation model of the energy hub is being developed. The basic principles of building a simulation model of an energy hub concept are discussed. Realization of simulation model using Matlab/Simulink is proposed. Simulation results for the integrated electricity and heat systems are explained to demonstrate the capabilities of the simulation energy hub model. A case study for application of the simulation model is discussed.

The purpose of the calculation is to substantiate the fulfillment of the mechanical safety requirements for the design solutions of the building of refrigeration machines.The calculation confirms that in the process of operation, the building and its foundation will not reach the limit state in terms of strength, stability and deformations with the variants of simultaneous action of loads and impacts taken into account by this calculation.

More than 4300 Eurasian elk (Alces alces) incisors, most of them pendants, were found in 84 burials in the Late Mesolithic cemetery of Yuzhniy Oleniy Ostrov, Northwest Russia. We analysed the manufacture techniques of elk teeth (4014), in the collection of the Peter the Great Museum of Anthropology and Ethnography, St Petersburg. A striking observation is that the manufacture of these pendants is similar in all burials. Teeth were worked by carving one or several grooves around the root tip. In addition to grooved ones, a number of teeth were not worked at all. The uniformity of the chosen species, tooth and techniques indicates that strict norms prevailed in the pendant industry. Despite the overall similarity, our study shows some variation in making pendants. A groove can cut the whole circumference of the root, or several distinct grooves can mark opposite sides of the root. Sometimes the grooves are deep and made carefully, and sometimes they are weak and made hastily. A typology of various groove types was created. In many graves, one groove type dominates. We interpret that this inter-burial variation and domination of one type resulted from personal choice and taste based on practicality. Such variation could also be associated with kin identifiers, but we did not find clear support for that in our study. Our study indicates that the groove types as such had no connection with particular ornaments, garments or hanging positions.

This paper presents the results of pollen, diatom, charcoal, and sediment analyses from Lake Bol’shoye Zavetnoye, situated between the Gulf of Finland and Lake Ladoga on the Karelian Isthmus, north-western Russia. The main goal is to contribute to the discussion of Neolithic land use in north-eastern Europe. The article aims to answer questions related to Stone Age hunter-gatherer economy, ecology, and anthropogenic environmental impact through a comprehensive combination of multiple types of palaeoecological data and archaeological material.According to diatom data, Lake Bol’shoye Zavetnoye was influenced by the water level oscillations of Ancient Lake Ladoga during much of the Holocene. Intensified human activity and prolonged human occupation become visible in the Lake Bol’shoye Zavetnoye pollen data between 4480 BC and 3250 BC. During the final centuries of the Stone Age, a new phase of land use began, as several anthropogenic indicators, such as Triticum, Cannabis, and Plantago lanceolata appear in the pollen data and a decrease in Pinus values is recorded. In general, the results indicate that socio-cultural transformations could have taken place already from the mid-5th millennium BC onwards, including new ways of utilizing the environment, perhaps also in the field of subsistence, even though the livelihood was based on foraging throughout the period.

Transformation of energy systems under the impact of internal and external factors remarkably strengthens the technological integration of those systems and supports development of integrated multienergy systems. The paper discusses the problems of modeling the integrated energy systems and proposes an approach to construction of a simulation model using the Matlab/Simulink software and the energy hub concept.

Constructions involving speech act verbs are a well-known diachronic source of adverbial connectors, but the latter have so far received less attention in the literature compared to other common products of grammaticalization of verba dicendi, such as reportatives or complementizers. This paper focuses on dicendial causal markers in the languages of Eurasia. The majority of such elements fall into two distinct types (“saying / having said” and “if you / one say(s) why”), defined on the basis of their formal make-up, but clearly diff erent in their positional and semantic properties as well. It is shown that the differences between the two types are directly linked to their diachronic origins. Previously proposed universal grammaticalization clines for speech act verbs can only be relevant for the fi rst type. The paper also puts forward hypotheses concerning the syntactic status of causal clauses introduced by markers of the two types and sketches prospective avenues for further languagespecific research.

The review of the book by P.V. Fedorov and A.A. Malashenkov “Soil on the Northern rocks: Orthodox necropolis of the Murmansk coast of the Barents Sea (1863–1920)”. The study based on the processing of metrical books made it possible to publish the information about 2,524 persons of the Orthodox religion buried on the Murmansk coast, or drowned in the sea in 1863–1920. The Authors found the demographic statistics related to the appearance of the settlements with permanent population. The book clarifies the idea of “cultural soil”, local and family-genealogical structures in the Russian Arctic, and it also contributes to the historical personification of the Murmansk coast.

The paper presents the principles of constructing a simulation model of an integrated multi-energy system based on the energy hub concept. An example of application of the developed simulation model is given. The proposed approach offers a broad prospect for the study of many significant problems in integrated power systems with multiple carriers, including their properties, features of expansion and operation. This paper makes a contribution to the important area of research at issue.

Integrated multi-energy systems give good possibilities to have high effectiveness of energy supply to consumers. The concept of energy hub is developed for modeling and simulation of integrated multi-carrier systems. Based on previous investigations, in this paper the authors develop the simulation model of energy hub. Basic principles of designing simulation energy hub model are discussed. Realization of simulation model using Matlab/Simulink is suggested. Simulation results for integrated electricity and heat demand systems are explained as the possibilities demonstration of simulation energy hub model.

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The presence of a great number of technical facilities that form a base of the intelligent network in the modern electric power systems require a principally new approach to the research into the dynamic operating conditions of these systems. Currently consumers impose higher requirements for the quality of electricity and reliability of electricity supply. Therefore, the operating conditions of such power systems and their control, including that in the emergency conditions represent a challenging problem that needs to be studied. The paper presents the results of numerical modeling of an off-grid power system. The algorithms were tested using a reference model of the off-grid electricity supply system. The authors use a universal approach to the mathematical modeling which is based on the input-output system represented as Volterra integro-power series. Staged training inputs were applied to identify transient characteristics.

The paper presents the principles of constructing simulation models of the components of an integrated multi-energy system based on the energy hub concept. The application of the algorithms designed to develop simulation models of the components are given, the results of their implementation are verified with generally accepted theoretical approaches used to obtain the necessary characteristics depending on the set objective functions. The proposed approach offers a broad prospect for the study of many significant problems in integrated power systems with multiple carriers, including their properties, features of expansion and operation

The presence of a great number of technical facilities that form a base of the intelligent network in the modern electric power systems requires a principally new approach to the research into the dynamic operating conditions of these systems. Currently consumers impose higher requirements for the quality of electricity and reliability of electricity supply. Therefore, the operating conditions of such power systems and their control, including that in the emergency conditions represent a challenging problem that needs to be studied. The authors use a universal approach to the mathematical modeling which is based on the input-output system represented by Volterra integro-power series. Staged training inputs were applied to identify transient characteristics. The calculation results presented in the paper demonstrate an increase in the modeling accuracy due to a more complete consideration of information on system outputs to the test inputs.

Currently, due to the global shortage of energy carriers the goal of more efficient use of the existing power sources and transmission lines is getting increasingly more important. At the same time, however, there is a known contradiction. In order to enhance the efficiency, we use advanced industrial electronics, rectifiers, frequency transducers, inverters, etc. This increases the efficiency of the technological plants, but at the same time the supply voltage suffers from an elevated level of harmonic components in the network. As is well known, nonlinear load generates harmonic components, resulting in a change of delivered power characteristics, namely indicators degrades the supplied power quality. In turn, the deterioration of the power quality leads to its overrun. In this regard, the problem of monitoring and reducing the harmonic components is relevant. Timely and accurate measurements based on data recorders vector quantities with high resolution, offers the prospect of continuous monitoring of the quality of power supply. The paper presents a system of continuous power quality monitoring. The system makes it possible to detect a source and a level of nonlinear distortions (harmonics), estimate the harmonic energy cost and control power quality parameters.

The research is dedicated to the integro-power Volterra series application in the description of nonlinear dynamic input-output systems. The paper presents a new algorithm for the identification of Volterra polynomial of the second degree for non-stationary dynamic systems which allow an active experiment using test sets of input signals. A horizontal - axis wind turbine is used for a test case study. The quadratic Volterra polynomials are constructed. They describe the nonlinear dynamics of the angular velocity of the wind turbine components depending on the blade lean angle and wind speed. The practical identification of Volterra kernels was carried out with respect to some random stationary state of a modeled system.

The most modern technical systems are an integration of various energy converters and sources of various physical nature. Mechanical, thermal, electromagnetic, as well as computer (information) monitoring and control system. Multi-energy systems (MES) also belong to the class of such technical devices. The main task in creating mathematical models is a methodological approach that allows joint modelling of 6 energy objects of various nature on a single methodological basis. The article considers the main approaches to the mathematical description of MES, as well as the assumptions and stages of formation for modelling this class of technical systems. The main advantages and disadvantages of the proposed methods for creating mathematical models are considered taking into account the possibility of using optimization methods and using the above models as digital twins for control systems. In addition, the article will present a methodological approach to the formation of mathematical models of an integrated energy system based on the concept of an energy hub using MATLAB.

The paper presents an approach to the construction of a system for automatic control of nonlinear dynamic objects on the basis of Volterra polynomials. The dynamic characteristics of control in terms of the electromechanical facility location are studied. Consideration is given to a model of horizontal-axis wind turbine represented by a system of the nonlinear first order differential-algebraic equations.

Many regions in Russia have no centralized electricity supply because of their geographical location. Taking into account variable electricity generation, available energy storage systems, as well as stricter requirements imposed by consumers on power quality and electricity supply reliability, we can say that operating conditions of such systems and their control, including emergency control, represent a difficult problem that needs to be studied. Generation from wind power plants, however, is a vivid example of stochastic operation of generators. The research is aimed at developing algorithms for the construction of automated systems to control active components of the electrical network. The method applied in the research to describe the object of control is based on the universal approach to the mathematical modelling of nonlinear dynamic system of a black-box type represented by the Volterra polynomials of the N-th degree. This makes it possible for the input and output characteristics of the object to obtain an adequate and fast mathematical description. Results of the computational experiment demonstrate the applicability of the mathematical tool to the control of active components of the intelligent power system.

The construction of automated systems intended for the control of electric power systems requires high-speed mathematical tools. The research is aimed at developing algorithms for the construction of automated systems to control active components of the electrical network. The method applied by the authors to describe the object of control is based on the universal approach to the mathematical modeling of nonlinear dynamic system of a black-box type represented by the Volterra polynomial of the N-th degree. The paper presents a new algorithm for the identification of Volterra polynomial of the second degree for non-stationary dynamic systems which allow an active experiment using test sets of input signals. This makes it possible for the input and output characteristics of the object to obtain an adequate and fast mathematical description. The results enable us to assess the applicability of this mathematical apparatus to the control of active components of electric power system in which power quality parameters are taken into account as an objective vector.

Based on geological and archaeological proxies from NW Russia and NE Estonia and on GIS-based modelling, shore displacement during the Stone Age in the Narva-Luga Klint Bay area in the eastern Gulf of Finland was reconstructed. The reconstructed shore displacement curve displays three regressive phases in the Baltic Sea history, interrupted by the rapid Ancylus Lake and Litorina Sea transgressions c. 10.9–10.2 cal. ka BP and c. 8.5–7.3 cal. ka BP, respectively. During the Ancylus transgression the lake level rose 9 m at an average rate of about 13 mm per year, while during the Litorina transgression the sea level rose 8 m at an average rate of about 7 mm per year. The results show that the highest shoreline of Ancylus Lake at an altitude of 8–17 m a.s.l. was formed c. 10.2 cal. ka BP and that of the Litorina Sea at an altitude of 6–14 m a.s.l., c. 7.3 cal. ka BP. The oldest traces of human activity dated to 8.5–7.9 cal. ka BP are associated with the palaeo-Narva River in the period of low water level in the Baltic basin at the beginning of the Litorina Sea transgression. The coastal settlement associated with the Litorina Sea lagoon, presently represented by 33 Stone Age sites, developed in the area c. 7.1 cal. ka BP and existed there for more than 2000 years. Transformation from the coastal settlement back to the river settlement indicates a change from a fishing-and-hunting economy to farming and animal husbandry c. 4.4 cal. ka BP, coinciding with the time of the overgrowing of the lagoon in the Narva-Luga Klint Bay area.

In building underground structures (bases and foundations of residential and industrial buildings, boreholes for hydrocarbon extraction, etc.) in cryolithic zones, cavities of various shapes and sizes saturated with liquid media often develop. When they refreeze, the refreezing pressure occurs; this may result in failure of the structural member continuity, and further failure of the structure as it is. The paper describes the calculation techniques for the refreezing pressure depending on cavity shapes and sizes.

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