Investigation of the Climatic Stability of Sealing Rubbers Used in the Technology of the North

2020 ◽  
Vol 992 ◽  
pp. 409-414
Author(s):  
M.D. Sokolova ◽  
A.F. Fedorova ◽  
M.L. Davydova

The present paper outlines the results of full-scale tests of climatic stability of rubbers based on BNKS-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing low-volatile and non-toxic phenolic antioxidants. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in deformed state (by 30%). Such indexes of the samples as conditional tensile strength, elongation at break are measured to determine the resistance of rubbers to aging after the first, third, sixth, ninth, twelfth and eighteenth months of exposing. The results of the study reveal the contribution of CO3 stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing CO3 has less property changes in the open air. Stafen stabilizer occurred more effective for the rubber based on Hydrin T6000: Over the entire period of full-scale exposure, rubber samples containing it demonstrated the smallest changes in the indicators of elastic-strength properties as compared to the industrial stabilizer 6РРD and other experimental stabilizers.

2019 ◽  
Vol 945 ◽  
pp. 433-437
Author(s):  
M.D. Sokolova ◽  
A.F. Fedorova ◽  
M.L. Davydova

The present paper outlines the results of full-scale tests of climatic stability and the study of resistance to the action of hydrocarbon media of rubbers based on BNKS-18-18 (butadiene-nitrile rubber) and Hydrin T6000 epichlorohydrin rubber containing one of 6PPDstabilizerwith an aromatic amine moiety widely used in synthetic rubbers. Samples are exposed in an open ground under natural conditions of exposure to climatic external factors of Yakutsk in the Republic of Sakha (Yakutia), as well as in the oil environment of Talakanskoye field and I-50A hydraulic fluid in an unheated room. Such indexes of the samples as conditional tensile strength, elongation at rupture, hardness and degree of swelling are measured to determine the resistance of rubbers to aging after the first, third, and sixth months of exposing. The results of the study reveal the contribution of 6PPD stabilizer in maintaining the stability of the physical and mechanical properties of BNKS-18: rubber containing 6PPD has less property changes both in the open air and in hydrocarbon media compared to rubber without a stabilizer. It should be noted that the oil environment is the most aggressive environment, the swelling of rubbers in oil leads to a significant reduction in strength due to a decrease in intermolecular interaction.6PPD stabilizer occurred less effective for the rubber based on Hydrin T6000: changes in properties of the samples containing the stabilizer are larger than those of the samples without the stabilizer. However, unlike BNKS-18-18-based rubber, the swelling of rubber based on Hydrin T6000 led to the greatest stability of the physical and mechanical properties in the oil environment compared to the open air and hydraulic fluids.


2021 ◽  
pp. 009524432110290
Author(s):  
Mariya L Davydova ◽  
Aytalina F Fedorova

This article represents the results of a study of changes in the properties of vulcanizates based on BNR-18 butadiene-nitrile rubber containing as stabilizers the experimental spatially hindered phenols Stafen, CO3, CO4, and industrial antioxidant 6PPD, after accelerated aging (100°C 96 h) and aging under full-scale exposure in extreme climatic conditions of the Republic of Sakha (Yakutia) during 2 years. In winter, the air temperature reached—48°C, in summer—+36.1°C. It is shown that the experimental sterically hindered phenols more effectively under natural exposure conditions. They are characterized by the most stability in terms of strength throughout the entire exposure period. Under conditions of accelerated aging, the vulcanizate containing the industrial antioxidant 6PPD is characterized by the greatest stability of physical and mechanical properties. According to the viscoelastic characteristics obtained in the dynamic loading mode, the contribution of the presented stabilizers in maintaining resistance to temperature and deformation effects compared with unstabilized rubber is confirmed.


2020 ◽  
Vol 192 ◽  
pp. 01028
Author(s):  
Sergey Sentyabov ◽  
Albert Zubkov

The extraction of solid minerals is associated with the penetration of man into the subsoil by creating either relatively simple or extremely complex structures. All mining operations can be safely and efficiently carried out only on the basis of calculating the stability of these structures, which is based on knowledge of the physical and mechanical properties, the stress state of the rock mass and the patterns of their redistribution and formation in mountain structures. The presented studies confirmed the regularities of the formation of natural stresses in the rock mass, which is the sum of gravitational, static tectonic and variable components, which are formed as a result of uniform periodic volumetric expansion and contraction of the Earth. The problem of shaft stability is due to the need to solve problems to determine the level of stress-strain state and strength properties in concrete lining. The parameters of stresses in the shaft lining and monitoring of their changes were determined using the method of measuring unloading deformations. When analyzing the stresses obtained experimentally by analytical means in the concrete lining of mine shafts, a connection was established with the results of measurements in the rock mass on the basis of 50 meters. Based on the experiment, it was confirmed that theoretical and experimental studies prove that a hierarchically blocky massif of magmatic and metamorphic rocks behaves as an elastic and isotropic medium and changes in natural stresses in the massif Δ on the basis of 5-7 ranks of geoblocks, on the contour of the trunk based on 2 –3 ranks of geoblocks and in the concrete lining of mine shafts Δσb obey this law.


Author(s):  
Нинель Васильевна Малышева ◽  
Марина Анатольевна Осорова

В статье рассматриваются фоноструктурные особенности якутских наименований лекарственных и пищевых растений в сравнении с эвенкийскими лексемами. С глубокой древности растительный мир играет важную роль в деятельности коренных народов Севера. Лексика растительного мира якутского языка, в частности лекарственные и пищевые фитонимы, как отдельная лексико-семантическая группа вызывает огромный интерес в связи со своей малоизученностью. До настоящего времени якутская лексика растительного мира не являлась объектом специального научного исследования в сопоставлении с языком эвенков, проживающих по соседству на территории Якутии. Цель данного исследования - выявление фоноструктурных особенностей якутских наименований лекарственных и пищевых растений в сравнении с эвенкийскими лексемами. Материалом исследования послужили лексикографические источники по якутскому и эвенкийскому языкам, а также языковой материал, собранный нами в ходе полевых работ и экспедиционных исследований в районах Республики Саха (Якутия). В статье использованы сравнительно-сопоставительный, типологический, структурный, описательный и количественно-статистический методы. В ходе анализа было выявлено 25 основ, относящихся к якутско-эвенкийским лексическим параллелям, обозначающих наименования лекарственных и пищевых растений в рамках следующих тематических групп: «хвощ» (2), «боярышник» (4), «кедровый стланик» (2), «ягель / мох» (4), «красная смородина» (2), «осока» (2), «черная смородина» (2), «листвень» (3), «осина» (2), «ревень» (2). Фоноструктурный анализ лексических параллелей якутского языка в сравнительном плане с эвенкийским также позволил выявить устойчивость фоноструктурных оформлений основ; особенности изменений фоноструктурных типов якутских форм в сравнении с эвенкийскими основами; основные причины неустойчивости фоноструктур именных основ эвенкийского языка в якутском языке; соответствия согласных / гласных. The article considers the phonostructural features of the medicinal and edable plants’ names in the Yakut language in comparison with the Evenk lexemes. Since ancient times, plants have been playing an important role in the activities of the indigenous peoples of the north. The lexis of the Yakut plants (medicinal and edable phytonyms), being a separate lexical-semantic group, is of great interest due to its being studied rather poorly. The vocabulary of plants’ names in the Yakut language has not been the object of specific scientific research in a comparative aspect with the Evenk language until now. The purpose of this study is to identify the phonostructural features of the Yakut medicinal and edible plants’ names in comparison with the Evenk lexemes. Lexicographic sources on the Yakut and Even languages, as well as the linguistic material collected in the course of the field work and expeditionary research in the regions of the Republic of Sakha (Yakutia) served as the material for the research. The article employs comparative, typological, structural, descriptive and quantitative-statistical methods. The analysis revealed 25 main lexical stems related to the Yakut-Even lexical parallels, denoting the names of medicinal and edable plants within the following thematic groups: “horsetail” (2), “hawthorn” (4), “dwarf cedar” (2), “reindeer moss/moss” 4), “red currant” (2), “sedge” (2), “black currant” (2), “larch” (3), “aspen” 2), “rhubarb” (2). The phonostructural analysis of the lexical parallels of the Yakut language in comparison with the Evenk language also revealed the stability of the phonostructural designs; peculiarities of the changes in the phonostructural types of the Yakut forms in comparison with the Evenk stems; the main reasons for the stability of the phonostructures of the nominal foundations of the Evenk language in the Yakut language; consonant/vowel correspondence.


2020 ◽  
Vol 2 (440) ◽  
pp. 83-91
Author(s):  
T.К. Kuatbayeva ◽  
Zh. Т. Nashiraliyev ◽  
Z. М. Zhambakina ◽  
М. G. Bruyako ◽  
А. Т. Orynova

The article considers the issues of technology of silicate materials of dense and cellular structure with usage of oil bituminous rocks and waste from their processing, in particular: the optimization of the ratios of the raw components of a silicate materials mixture, the development of optimal technological parameters for the production of silicate materials, and the technological aspects of the production of the above materials. The optimal compositions of binders with use of waste products from OBR are studied in this work as an activating component of lime or cement. The stability of the samples was studied in various media with a low and high content of basic calcium hydrosilicate. If they contain insoluble silicates and aluminosilicates containing silica, they are acid resistant. Alkali-resistant rocks containing oxides corresponding to strong bases are combined with oxides corresponding to weak acids, for example, calcium and magnesium carbonates. As a result of the experimental work, technological processes for the manufacture of silicate materials (of dense and cellular structure) based on the OBR and waste from their processing are substantiated and developed. The paper reveals the chemical-mineralogical and the structural features of oil bituminous rocks and waste from their processing. The optimal ratio of the waste mixture of oil and bituminous rocks with lime and the technological parameters that ensure the grade of lime-sand binder from 400 to 500 are established. Silicate materials based on this mixture have high physical and mechanical properties and comply with the requirements of the ST standards of the Republic of Kazakhstan for silicate brick and GOST state standard for aerated concrete. Thus, the compositions and conditions for the preparation of these binders with high resistance in large temperature, pressure and aggressive environments are proposed in this work. Key words: oil bituminous rocks and waste from their processing, structure, mechanochemical activation, silicate materials, binder, cellular concrete, durability.


1976 ◽  
Vol 21 (2) ◽  
pp. 20-30 ◽  
Author(s):  
Robert A. Johnston

An aeroelastic rotor stability analysis that provides a very complete description of the dynamics and aerodynamics of fully coupled rotor/airframe/control systems, representative of main or tail configurations is discussed. The analysis, which gives system eigenvalues and eigenvectors, can be used to study the stability of rotors in conditions of pure axial flow or for forward flight studies at advance ratios up to about 0.5. Various examples of correlation with scale model and full scale tests are given and the capability of the analysis to predict certain unstable phenomena is demonstrated through correlation with test occurrences. The importance of accurately defining the physical properties of the systems being analyzed is noted and the need for continued development and comprehensive correlation studies is cited.


2018 ◽  
Vol 12 (7-8) ◽  
pp. 92-100
Author(s):  
D. V. SAVVIN ◽  
L. L. FEDOROVA ◽  
E. E. SOLOVIEV

Тhe territory of the Republic of Sakha (Yakutia) is located in the north-eastern part of the Eurasian continent, the Republic is the largest region of the Russian Federation. One of the features of the region is the presence of permafrost. The construction and exploitation of engineering structures is conducted in a harsh climate and difficult engineering-geocryological conditions on this territory. In this case, the disturbance of thermal equilibrium of permafrost, is accompanied by subsidence, deformation of the buildings foundation and structures, and sometimes to their partial destruction. The article presents the results of GPR studies for engineering-geological surveys in Central Yakutia are presented. The relevant research focused on the improvement of assessment of informativeness, efficiency and authenticity of ground condition according to the indications of remote geophysical methods, in particular GPR, is being examined. The results of studies aimed at studying the characteristic features of GPR wave fields for the development of signs of the interpretation of cryogenic processes and phenomena in the soils of the foundations of engineering structures according to GPR data are presented. The wave fields characteristics and GPR signs of talik, water-bearing zones, areas of weakening of the soil, increase the capacity of the active layer caused by the thawing of permafrost, infiltration of the supra permafrost water boundaries identification have been developed and are determined . The selection of interpretative features of permafrost processes at the research site was carried out by comparing the results of GPR with drilling data and analysis of the wave pattern, which considered the configuration, intensity, length of the in-phase axes. The good reproducibility of GPR investigation with the data of electrical resistivity tomography (electrical sounding, multipole sounding) is shown. The effectiveness of GPR in identifying zones, associated with the development of negative cryogenic processes, recommended for drilling for determination of physical and mechanical properties of soils, for example, complicated permafrost conditions of Yakutia.


2020 ◽  
Vol 86 (6) ◽  
pp. 48-54
Author(s):  
N. I. Golikov ◽  
M. M. Sidorov ◽  
I. I. Sannikov ◽  
A. K. Rodionov

The residual strength and technical condition of the material of 530-mm steel pipe (14KhGS) of main gas pipeline are estimated to ensure the safety of long-term operation of pipelines in climatic conditions of the North. The mechanical properties are determined using standard methods of mechanical testing in laboratory conditions. A full-scale pressure test up to failure is used to determine the actual values of the fracture toughness and safety factor of the pipe. Full-scale tests were carried out on a test bench, a computer-measuring complex which displayed the reaction of the object to the load. A pipe fragment was cut from the linear part of the main gas pipeline and welded with spherical plugs. The outer surface of the pipe was notched along the pipe axis. The depth of the notch was calculated such that the breaking load on the ligament section at the notch site corresponded to the working pressure of the gas pipeline. No significant changes in the mechanical properties of the pipe metal were revealed in the absence of visible corrosion and deformation damage during long-term operation of the pipe in the North. Impact tests did not reveal embrittlement of the metal of the tested pipes. Full-scale tests of a pipe with an artificially applied defect made it possible to calculate the value of the critical stress intensity factor, which allowed us to estimate the residual strength of a pipe with a longitudinal crack. The value of the strength criterion of the fracture mechanics indicates the preservation of a sufficiently high viscosity of sheet metal pipes. Similar tests of the pipes (of other size and made of other materials) operating in the main gas pipelines should be continued taking into account temperature ranges and material degradation after long-term operation.


2020 ◽  
Vol 8 (3) ◽  
pp. 74-78
Author(s):  
Farrux Zulfiyev ◽  

This article is based on the principles of shared financing of the production of raw materials. The article is aimed at financing the production of capital on the basis of equity in order to further strengthen the stability of economic reforms in the republic. At the same time, the essence of equity financing, the risks associated with it, and the efficiency of raw materials are covered


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