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Magnetic iron oxide nanoparticles: synthesis, surface modification, and functionalization by luminescent materials

https://doi.org/10.58224/2618-7183-2023-6-2-58-80
 58-80 p.
Abstract
From the standpoint of current science and engineering, iron oxide particles exhibit remarkable physical and structural features, particularly in the nanoscale range. Several methods have been studied to fabricate magnetic iron oxide nanoparticles and determine how they affect the size, size distribution, elemental composition, crystal structure, and a variety of other physical properties of nanoparticles. Advances in surface chemistry strategies for the functionalization of iron oxide-based magnetic nanoparticles (IONPs) are also explained. This review aims to present a summary of emerging activity relating to composite magneto-fluorescent nano-objects. Due to the high surface energies of iron oxide nanoparticles, agglomeration over time is often encountered. It is thus of prime importance to modify their surface to prevent aggregation and limit non-specific adsorption of fluorescent molecules onto it. Furthermore, the diverse strategies for the covalent linking with fluorescent organic dyes have been discussed, and the chemically relevant steps have been explained in detail. Surface coating and functionalization of iron oxide NPs allow them to attach to fluorescent molecules and prevent photoluminescence quenching entities by the magnetic core, making them a promising candidate for nondestructive magnetic inspections based on nanoparticles.
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Prerequisites and Trends in the Architecture of Modern Circuses

https://doi.org/10.58224/2618-7183-2023-6-2-81-103
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 81-103 p.
Abstract
The article considers the prerequisites for the emergence and development of circuses typology, from street circuses, arenas, then tent constructions of circuses-chapitos to the formation of a stationary circus building. The periods of circuses' existence in Europe as well as in domestic practice are studied. Circus buildings in different periods, their formation, architectural appearance and the functional content of the planning solutions are discussed. In the process of writing the article different methods were used for the study and analysis: a comprehensive analysis of the design materials, photofixation, review of professional literature and publications. The objects of foreign practice, the Soviet and Russian design experience were chosen for the analysis. On the basis of this study the following conclusions were obtained. In Europe and in Russia existing circuses are reconstructed. There is no new permanent circuses being built in Europe, unlike Russia, where the continuation of the Nikitin circus traditions is traced both in circus art and in the architecture of the permanent circus. The circus is losing the niche of performing with animals, where they remain in the circus, and control over their housing, housing, and transportation is becoming stricter. There is a tendency to build multifunctional public entertainment buildings with elements of circus performances. There are still circus circuses, and in the future they will either be stationary circuses on tour, or a new kind of circus circus similar to Cirque du Soleil.
A modern circus is a multifunctional, unique architectural object, a spectacular building, which combines circus art and various show performances (on ice, on water, in the air). The central core re-mains the main arena. Currently it is a round arena, but it may be reconstructed in the future. Circus is a cultural and historical heritage in Russia.
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Method for calculating the strength of massive structural elements in the general case of their stress-strain state (parametric equations of the strength surface)

https://doi.org/10.58224/2618-7183-2023-6-2-104-120
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 104-120 p.
Abstract
In the mechanics of a deformable solid, there are rods (one overall dimension of which is significantly larger than the other two), plates and shells (one dimension of which is significantly smaller than the other two), arrays (all three dimensions of which are of the same order). The complexity of the corresponding calculation models grows in the same order: the calculation models for rods and rod systems are relatively simple, the most complex are the calculation models for massive structural elements.
In the work, parametric equations of the strength surface in the space of internal force factors (IFF) are obtained – 9 forces and 9 moments for homogeneous anisotropic bodies. As special cases, similar equations are given for isotropic bodies that resist tension and compression differently, for isotropic bodies that equally resist tension and compression. Algorithm A1 for constructing the desired sections of strength surfaces given by parametric equations is proposed. Algorithm A2 is proposed for deter-mining the safety factors for the bearing capacity, remaining in the space of the IFF. Some examples of calculations made using the proposed equations, algorithms and the corresponding computer programs compiled on their basis are given.
The proposed method for calculating massive bodies allows a more realistic assessment of the bearing capacity of massive structural elements.
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Ecological Safety of Construction in the Concept of Sustainable Development

https://doi.org/10.58224/2618-7183-2023-6-1-5-17
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 5-17 p.
Abstract
The article describes the importance of following global trends in the field of ESG transformation, reveals the relevance of this direction, and also describes the basic principles of ESG in the construction industry. Based on the analysis of research in this area, the main reasons that impede the promotion of the principles of sustainable development of construction companies are identified. Par-ticular attention is paid to the environmental aspect, a comparison of "green" standards is carried out and the main directions for the development of ESG in construction are highlighted.
In the 21st century, the main trend in the construction industry of the leading countries of the world has been the development of environmentally friendly technologies and "green" design. With the de-velopment of information technology, the life of people, primarily those living in megacities, is be-coming more comfortable.
They become more informed about the methods of a healthy lifestyle, including the use of environ-mentally friendly products in their life. People prefer such places of residence, where materials harm-less to the body are used in construction. In the foreign practice of industrialized countries, when de-signing buildings and structures, preference is always given to natural materials or products of their processing. The advantage of buildings made of natural materials is, along with their compliance with environmental requirements, that they allow you to create a healthy space in the building area.
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The Problem of Preservation of the Existing Architectural and Historical-Cultural Landscapes of Resort Cities of the South Coast of Crimea

https://doi.org/10.58224/2618-7183-2023-6-1-18-28
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 18-28 p.
Abstract
In accordance with the project "The Historical Cultural Landscape of the Southern Coast of Crimea as the Basis for Socio-Economic Development" dated 06/08/2021, prepared by a working group chaired by the head of the administration of the city of Yalta Yanina Pavlenko, it is planned to preserve the historical and cultural landscape with cultural heritage sites of the resort towns of the Southern coast of Crimea (South Coast). In accordance with this, the purpose of the research is to determine the main approaches to preserving the compositional, stylistic and figurative characteristics of the existing architectural ensemble in the historical and cultural landscape of the central part of the resort towns of the South Coast using the example of the city of Yalta. In the course of the study, the features of the historical, cultural and natural landscape, the historical and cultural value of the city of Yalta were studied, the main existing architectural and compositional characteristics of the ensemble of the central part of the resort town, stylistic solutions for accent city-forming public objects were identified. A comparative graphic-analytical analysis of the silhouette originality of the ensemble from the side of the embankment, which was formed in different historical periods, was carried out. As a result of the research, the principles of preservation and restoration of the architectural, artistic and stylistic features of the ensemble, its volumetric and spatial characteristics in the historical, cultural and natural landscape in the modern building of the city of Yalta were determined, which will contribute to the development of the resort potential of the South Coast.
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Architectural and Structural Problems of Modern Museum Construction

https://doi.org/10.58224/2618-7183-2023-6-1-29-42
 29-42 p.
Abstract
The author proposes to consider the significant changes that have recently taken place in the construction and architecture of museums. There has been a fundamental change in society's attitude toward the museum as a source of knowledge, a source of spiritual values. Museum attendance is fall-ing. The way out that modern museums find is determined by the needs of society. And as a result, museums are going through a period of commercialization, which has defined the museum object as an object of entertainment. Museums are moving into the realm of large entertainment and educational centers with concert halls, libraries, conference rooms, children's areas, developed food areas, etc. At the same time, architects are challenging designers to provide complex shaping with modern materials and design solutions. In addition to this there is often a lack of space in the cities for the erection of such buildings. The team of the Department of Architecture at Moscow State University of Architec-ture and Civil Engineering has been working on this problem for many years and offers a new type of building. These are bridge and platform buildings, which are elevated large-span objects. Their design solutions involve the most modern structures in the form of steel reinforced concrete ceilings, multi-lattice trusses and a supporting floor system which allow large spans of up to 100-150 m to be covered, which in turn makes it possible to reuse the urban area previously occupied by railroads, freeways or industrial areas. Large spaces are created inside such objects without intermediate supports, which allows to place in them the most diverse objects in terms of their functionality, including museums.
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Folded Structures in Architecture – The Forgotten Past or the Fashion Returns?

https://doi.org/10.58224/2618-7183-2023-6-1-43-59
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 43-59 p.
Abstract
The article deals with modern trends in the development of folded structures in architecture. The periods of emergence and development of folded structures in foreign and domestic design practice have been studied. In the process of writing the article various methods were used to study and analyze folded structures (FR): a comprehensive analysis of design materials, photofixation, review of professional literature, publications. The objects of Soviet and Russian design experience and objects of foreign practice were selected for the analysis. The total number of objects of analysis is more than 40; the objects presented in the article are 26. On the basis of this study the task was set: to determine the directions in the development of SC in architecture for the near future.
At present, the interest in the folded structures has been revived. As a result of studies of SC in differ-ent time periods, from the beginning of their appearance to the present day, we can say that the folded structures "fashion returns". There are two trends in modern design with the use of SC. The first trend: a new round in the development of SC of long-span roofs and walls, and now there is a powerful basis in the form of programming complex structures to implement the creative potential of SC in the archi-tecture, there are innovative building materials and technologies for the implementation of the object. The second direction is related to the use of folded structures as façade folding elements, working ex-clusively to create a unique appearance of the building. Buildings using folded structures and elements become examples for a variety of contemporary styles in architecture. It is safe to say that folded structures are relevant in contemporary architecture. The use of folded structures and architectural folding elements provides great scope for the implementation of bold architectural ideas and the crea-tion of unique, individual architectural forms, volumes of buildings and structures for buildings of dif-ferent functions.
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Development of Alkali-activated Binders based on Technogenic Fibrous Materials

https://doi.org/10.58224/2618-7183-2023-6-1-60-73
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 60-73 p.
Abstract
The paper discusses the development of alkali-activated binders based on technogenic fibrous materials. An approach to the secondary use of technogenic fibrous materials as a filler of composite binders is offered. The properties of mineral wool waste have been established. The microstructure of finely ground fibrous particles has been studied. Compositions of alkali-activated binders were de-veloped, when grinding basalt insulation production waste to a specific surface of 300-330 m2 /kg, followed by the formation of a binder according to the first method with rod tamping sealing and, ac-cording to the second, by pressing a raw binder mixture at a pressure of 10 MPa. The developed com-positions of alkali–activated binder by pressing with a compressive strength of 22.8 MPa, and when compacted with subsequent rod tamping – 11.8 MPa.
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Сompositional analysis: the project of the III Communist International Monument (Tatlin Tower)

https://doi.org/10.58224/2618-7183-2023-6-1-74-83
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 74-83 p.
Abstract
The authors of the article broadcast information about the study of the compositional activity of architects of Soviet Russia in the 20s of the XX century. in line with the trend of "constructivism". The study of three-dimensional architectural composition is considered by the authors as the separation of the "indivisible whole" (integrity – the law of composition) and "unchangeable for further im-provement" (it is impossible to make changes without deterioration of the already created, completed composition) artificially created object – organism of universal laws and means. The authors believe that the study of high–class Heritage samples is based on the separation of formal (composite) ele-ments (contrast, plastic, texture, plane – volume, rhythm, modular divisions, construction, engineering materials, walls, floors, ceilings, fasteners, etc.) from an artificially created composite organism. The analysis allows you to develop compositional thinking, taste and teaches you to understand the course and origins of the Master's compositional thought. The study of the formal (compositional) sphere of the Heritage of the classics of modernity and past eras allows you to build the path of the author's work on the project, avoiding mistakes and disappointments.
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Reinforcement of construction of underground structures with shotcrete

https://doi.org/10.58224/2618-7183-2022-5-6-5-18
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 5-18 p.
Abstract
An urgent scientific task, which is of great practical importance for increasing the defense capability of the state and preserving the population, is the improvement of constructive methods for the complex repair of underground structures. Reinforced shotcrete concretes have been developed and their research has been carried out to strengthen underground structures. Achieving the uniform workability of shotcrete (slump 19 cm) was carried out by varying the dosage of the superplasticizer, which has a high water-reducing ability (40%). Some reduction in slump flow (47 cm) was observed at a dosage of ACC in the amount of 35 wt. %. An increase in the density of the mixed mixture with an increase in the content of the aluminosilicate component in the polymineral binder was established. The introduction of the alumino-silicate component in small quantities (up to 25 wt.%) slightly increases the 28-day density of the cement paste (0.3-0.4%). With an increase in the dosage of ACC (up to 35 percent by weight), an increase in the density of 28-day-old samples was noted, which linearly raised with an increase in the amount of introduced aluminosilicates. The effect of increasing the compressive strength of shotcrete concretes on a polymineral binder increased with an increase in the dosage of ACC up to 35% by weight, and the maximum effect is noted for early strength values, in particular, at the age of 1 day, an increase in compressive strength by compared with the composition without additives was 56%, and with bending 62%. This is also confirmed by the high ratios of the values of strength properties in the first day to similar indicators in the grade age: for compressive strength 0.27 (0.23 for clinker compositions without additives), for bending strength 0.30 (0.26 for additive-free clinker compositions). Theoretically and practically proved the effectiveness of the use of the developed shotcrete for strengthening the supporting structures of underground structures with an increase in strength of more than 2 times, which is explained both by the high strength of the obtained repair composition and the monolithic contact zone between the old and new layers of concrete. The developed shotcrete is able to provide the necessary degree of strengthening of the supporting structures of underground structures, while the thickness of the repair layer of 6 cm (with proper soil fixation) allows the use of underground structures as dual-use facilities.
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