Vol 19, No 4 (2018)

Large space structures (LSS) occupy a special place among other objects of space technology. Due to their large size, these structures are compactly stowed under the fairings of the launch vehicles or in the cargo compartments of the Space Shuttle type spacecraft. After launch into the working orbit, they are deployed automatically into the predetermined configuration with the help of transformable elements, which act both as the load-bearing frame and actuators. The deployment should be carried out within the specified time and should not negatively affect the strength, shape or spatial orientation of the structure. To meet these requirements, it is necessary to theoretically investigate the deployment dynamics of the LSS under consideration. This paper aims to find the optimal design and engineering solutions of an ultralight transformable reflector for a space antenna made of metal mesh with load-bearing elements in the form of telescopic hollow rods made from carbon fiber reinforced plastic. The deployment dynamics of the load-bearing elements with the mesh attached was modeled using the Russian-made software package EULER 10.25. The modeling allowed us to estimate the effect of the tensile load from the mesh on the deployment process. With the elastic load from mesh accounted for, the stability and rigidity of the load-bearing elements will be ensured and the accuracy of the mesh tension will be increased.

At present time, the architects began to show interest in the creation of space large-span shapes due to advent of new materials and building construction technologies. Increased ergonomic requirements for structures and erections are now a great significance. This approach can be seen in many projects, both implemented in material and still being at the stage of drafts and blueprints. Now in economically safe countries, there has already been a splash in the creation of new unique structures, including spatial ones with complex surfaces. It is necessary to prepare for such prospect also in our country. Currently, a large number of surface classifications is offered, but they do not cover the all variety of known surfaces. This article introduces a classification of both new and widely known surface shapes as applied to the structures of building and industrial purposes. A detailed classification of analytic surfaces of 38 classes is constituted. An extensive bibliography containing 40 references is presented for convenient search of studies in the field of geometry and strength analysis of thin shells with the non-canonical middle surfaces.

Climate is one of the important factors in architecture. The historical architecture experience of the inhabitants of the desert zones has created invaluable knowledge on the design of residential environments in these aggressive conditions. Climate also is an important ecological component in the formation of vernacular architecture in the Saharan desert, it had a strong influence on the formation of desert settlements, the Saharan traditional dwellings are an indispensable source for studying organizations and architectural typologies and the adaption to the harsh climate. The article discusses the climatic conditions in which the dwellings in the Sahara desert were built and the important strategies and passive climatization techniques of the design of the dwellings and presents a review of the various techniques developed. These various passive methods and strategies give the Saharan dwellings, adaptation, efficiency, and durability in these hot-arid conditions of the desert and can be a great source of architectural inspiration for new projects.

The article displays information about the Gulf of Guinea and presents the results of gravity anomalies calculations for the forecast of the probable discovery of gas hydrate deposits on the shelf of Cote d’Ivoire by analogy with the shelf of Brazil. Similar features of the geological structure and geophysical anomalies on the shelf sections on different sides of the Atlantic Ocean are shown. The main problem in organizing the search for gas hydrates on the shelf of the Gulf of Guinea is political instability, as well as the lack of funds for research in the Ivorian shelf. And because of the complexity of the extraction of oil resources, all major deposits in the country are conducted by international firms. Despite the low level of oil and gas production, Côte d’Ivoire retains prospects in the future to be an exporter of oil and gas (including gas hydrates), since the country’s sedimentary basin is still very little studied. The coverage of this issue is relevant due to the lack of such information in Russian, and the information available in English and French does not allow to form a general picture of the oil industry complex of the Republic of Cote d’Ivoire. In this article, the forecast of new sites, promising to detect gas hydrate deposits on the shelf of Côte d’Ivoire, and can be used in the allocation of promising areas for new geological studies.

The scope and the role of the secondary (catagenetic) processes in sedimentary-rock formation belong to the category of incompletely resolved and, therefore, the urgent problems of lithological science. The purpose of this work was to show, by means of stadium analysis, the huge “hidden” potential of catagenetic processes in the transformation of the mineral composition of sedimentary strata on the example of sulphate complexes. Boundary clay and carbonate sediments of Urzhumskiy and Sakmarskiy stage of Western limit of the pre-Ural trough were selected as the objects of study. It was found that their lithological appearance has been largely shaped by secondary (diaand catagenetic) processes of sulfate mineralization. And, if the first is reflected in the development of scattered concretionary nodules of gypsum, the latter manifested in large-scale metasomatism with the formation of large anhydrite-gypsum and gypsum-anhydrite lens and tabular bodies, stretching for hundreds of meters. It’s possible that metasomatic solutions were very reactive and moved with underground waters. Those solutions were as aggressive as lateritic weathering, and replaced not only the carbonates, but clay and ferrous minerals as well as quartz and feldspar detritus. All of this points to the high alkalinity and to the reducing atmosphere of sulphate of metasomatic solutions.

Precision topographic work is done by the means of classical instruments such as highprecision levels, theodolites and distance-meters. This method gives accuracy results of ±2 mm in altimetry and better than ±5 mm in planimetry, but it requires a lot of expenditures and a long time of execution and more staff. Nowadays, the constellation of the GNSS satellite positioning system and the improvements to electronic tachymeters can provide solutions to gaps in auscultation using conventional measurements. However, these methods also present their weaknesses, resulting by this way from their uses under the high voltage lines. The study of the influence of electromagnetic waves on high-voltage lines on topographic devices allows observations made with a GNSS receiver to be made from an electronic station or total station or with the aid of optical-mechanical theodolite to analyse and interpret the quality of the data obtained on the ground in the Maria Gléta zones in the municipality of Abomey-Calavi and Araromi in the municipality of Sakété. This makes it possible to present the effects of high voltage cables on these measurements and the determinations made in topometry. Very important on measurements at the GNSS receiver and at the total station, the actions of the electromagnetic waves evolve with the variation of the temperature.