Elastic moduli of sea ice and lake ice calculated from in-situ and laboratory experiments

The effective elastic modulus of ice is an important physical parameter for the calculation of ice stresses in different situations when ice deformations are small. In the present paper the review of methods used for the calculation of the elastic modulus of ice is performed, new tests for the calculation of the elastic modulus are described, and their results are discussed. Field experiments with floating vibrating ice beams with fixed ends were performed in March and November 2019 on sea ice of the Van Mijen Fjord and fresh-water ice of a lake near Longyearbyen. Laboratory experiments with vibrating cantilever beams were performed in the cold laboratory of UNIS in November 2019. The results are compared with the values of the effective elastic modulus obtained in quasi-static tests with floating cantilever beams, and with in-situ dynamic tests where the effective elastic modulus was measured by the speed of sound waves

Influence of vibrations on indentation and compression strength of sea ice

Indentation and compression strengths of floating sea ice subjected to vibrations is discussed. The experiments were performed on the land fast ice of the Van-Mijen Fjord in March of 2018 and 2019. The ice thickness was around 70 cm, and the ice salinity was 4-5 ppt. Vibrations were introduced in the ice by the vibration plate with weight of 400 kg before the tests during 10-15 min. The vibration plate was standing and vibrating on the ice surface. The spectrum of vibrations was recorded with accelerometers. Analysis of thin sections of ice was performed on the place of the field works. Indentation tests were performed with the original hydraulic rig on natural ice and ice subjected to the action of vibrating plate. It was discovered that stroke rates tests were higher in the tests performed on the ice subjected to vibrations. Uniaxial compression tests were also performed on ice cores taken from the natural ice and from the ice subjected to the vibrations. Uniaxial compression strength of ice cores taken from the ice subjected to vibrations was higher than in the tests with natural ice

Peculiarities of Circulation of Venezuelan Equine Encephalomyelitis Virus (Scientific Review)

Reviewed are some peculiarities of circulation of Venezuelan equine encephalomyelitis virus (VEE), the enzootic strains of which play an increasingly important part as etiological agents of human infections nowadays. The majority of VEE cases among the residents of the endemic regions within the inter-epidemic period are caused by the ID subtype of VEE that includes 6 genotypes. Isolated from humans have been the genotypes Columbia/Venezuela, Panama/Peru, and Peru/Bolivia, ID subtype of VEE. Possibility of emergence of new VEE outbreaks is associated with ID subtype mutation into the IC subtype, which is assumed to be a potential threat as etiological agent of the disease at present

Опыт специалистов ФГУП «Крыловский государственный научный центр» в разработке международных стандартов по арктическим операциям // Krylov State Research Cetre experience in development of international standards on Arctic operations

Abstract: Объект и цель научной работы. Объектом исследования является деятельность международного и национальных комитетов в части разработки стандартов по безопасности нефтегазовых объектов в условиях низких температур. Цель исследования – обобщение результатов работ по разработке стандартов подкомитетом ИСО/ТК67/ПК8 «Арктические операции». Материалы и методы. Международные и национальные нормативные документы в области обеспечения безопасности морских объектов при их проектировании и эксплуатации в условиях низких температур. Анализ этапов разработки международных стандартов и работы подкомитета «Арктические операции». Основные результаты. Обобщены стандарты, подготовленные подкомитетом ИСО/ТК67/ПК8 «Арктические операции», дано краткое содержание принятых ИСО документов и требований по безопасности морских объектов, проанализировано участие Крыловского государственного научного центра в разработке стандартов и требований к безопасности объектов. Заключение. Разработанные ИСО стандарты определяют международные требования и рекомендации для обеспечения безопасности арктических операций на нефтегазодобывающих объектах. Участие в подготовке стандартов ИСО специалистов ФГУП «Крыловский государственный научный центр» в качестве экспертов позволило более четко сформулировать принятые в стандартах требования по обеспечению безопасности объектов, обслуживающего персонала и окружающей среды в климатических условиях, характерных для российской Арктики. Object and purpose of research. This paper discusses the activities of international and national committees intended to develop safety standards for oil & gas facilities in cold regions. The purpose of this study was to summarize the results of work done by ISO/TC67/SC8 dealing with Arctic operations. Materials and methods. International and national regulatory documents on safety of marine facilities for cold regions at design and construction stage. Milestone analysis of international standard developments and Arctic operations subcommittee activities. Main results. This paper gives a summary of the standards prepared by ISO/TC67/PC8 Arctic operations and a concise description of ISO documents and regulations on safety of marine facilities, as well as highlights KSRC contribution to this work. Conclusion. ISO standards set international safety requirements for Arctic oil & gas facilities. Participation of KSRC experts in preparation of these standards enabled a more distinct formulation of safety requirements for facilities, their personnel and environment taking into account typical conditions of the Russian Arctic