Исследование влияния эксплуатационных факторов на свойства изоляции и оболочки гибких кабельных изделий

В данной работе рассмотрены основные эксплуатационные факторы, влияющие на свойства оболочек гибких кабельных изделий. Особое внимание уделено температуре и её допустимому диапазону. С помощью исследования физико-механических характеристик выбранных материалов оболочек, был определен материал, на свойства которого температурный фактор влияет меньше, что позволит при его использовании в кабельной промышленности сохранять надежность кабеля в течение длительного времени эксплуатации.In this paper, the main operational factors were considered, which affect the properties of flexible cable products shells. Special attention is paid to the temperature and its permissible range. Using the study of physical and mechanical characteristics of the selected materials of the shells, the material was determined, the properties of which the temperature factor affects less, which will allow its use in the cable industry to maintain the reliability of the cable for a long time of operation

Viable metabolisms in a simulated martian environments

Microbes have multiple ways of producing energy. Which of these methods are possible depends on the chemistry of the environment the microbes are in (e.g. not enough of a metal or too much salt), with only specific methods working in certain environments. The same would be true of any waters that might continue to exist on Mars. To narrow down which methods of producing energy would be theoretically possible we simulated martian waters using a collection of minerals that are chemically similar to the chemistry measured by the Mars rover Curiosity in a crater on Mars. We added mud from an estuary to the simulated martian water and identified which microbes were able to grow. We then repeatedly transferred the growing microbes to fresh “martian” water to dilute out the nutrients from the mud. Over time we observed that most of the microbes from the mud have been lost but a few specific microbes were growing well. From this we hope to investigate changes in the chemistry of the water that happen because of these microbes, to try and identify specific chemistries that can be looked for by the future rover missions on Mars seeking evidence of life

Microbial growth in simulated martian environments

In this study, four new simulants have been developed, and their associated fluid chemistries have been derived for use in a series of microbiological simulation experiments. These experiments will determine if aqueous environments on Mars, past or present, could potentially support microbial life and identify any key geochemical biosignatures that may arise as a result of that life

Testing the habitability of distinct simulated martian environments

Habitability of martian waters would have been partially determined by the chemistry arising from interactions with martian lithologies. In this study, the habitability of groundwater chemistries (based on basaltic, iron- and sulfur-enriched lithologies) and the resulting variation in biosignatures was investigated, with microbes from anaerobic estuarine sediment used as an inoculum. The microbial community was monitored by cell counts and 16S rRNA gene profiling. Changes in fluid and precipitate chemistries were measured using ICP-OES and IC, with changes over geological timescales modelled using CHIM-XPT. The fluid chemistries were shown to be habitable, with distinct patterns in cell abundance and growth phases between the chemistries. However, the same genera dominated (Acetobacterium, Desulfovibrio and Desulfosporomusa) regardless of the initial fluid chemistry. In the biotic test group, changes in fluid chemistry were the same in the three chemistries, with an enhanced concentration of aluminium and iron and the removal of sulfate. However, geochemical modelling of the fluids under abiotic conditions over geological timescales revealed similar changes to those in the biotic test groups. Therefore, these samples require further analysis to assess whether we can identify any potentially unambiguous biosignatures that could develop between geologically distinct sites

Colour Peak:An analogue environment for the waters of late Noachian Mars

The surface of Mars cannot sustain liquid water today, but there is evidence water was present during the Noachian era. The transition of the martian climate from the wet Noachian to the dry Hesperian would have resulted in saline and sulfur rich surface waters . Terrestrial analogue environments that possess a chemistry like these proposed waters can be used to develop an understanding of organisms that could have persisted under such conditions. Here we present the chemistry and microbiome of the analogue environment Colour Peak, a sulfidic and saline spring system located within the Canadian High Arctic. In this study, molecular and geochemical techniques were used to investigate the sediment of the Colour Peak springs. Nucleic acids were extracted from the microbes in the sediments and the microbiome was characterised by the amplification and sequencing of 16S rRNA gene amplicons. The elemental composition of the fluids and sediment was determined by ICP-OES and compared with brines determined from the chemistry of the “Rocknest” sand sample at Yellowknife Bay, Gale Crater (Mars) by thermochemical modelling. Gibbs energy values were calculated from this fluid chemistry to identify potentially viable metabolisms. Analysis of the chemistries of the Colour Peak fluids confirmed a chemical composition like the thermochemically modelled fluid, with this justifying the classification of Colour Peak as an appropriate analogue environment to investigate the habitability of former martian aqueous environments. 16S rRNA gene profiling of the Colour Peak microbial community revealed it was dominated by bacteria associated with oxidation of reduced sulfur species and carbon dioxide fixation. Gibbs energy values calculated using the chemistry of the modelled martian fluid demonstrated that the oxidation of reduced sulfur species was also viable in this chemical environment under aerobic and anaerobic conditions. These results demonstrate that microbial sulfide oxidation is thermodynamically viable using both modelled and environmental proxies for former martian aqueous environments. This study highlights that metabolisms utilising the oxidation of reduced sulfur species could have been thermodynamically viable in ancient martian aqueous environments. Further work is needed to assess this proposed viability and the potential for unambiguous biosignature formation

Biogeochemical Cycling in Globally Distributed Hypersaline Environments

Studying extremophiles allows the characterisation of the boundaries of life on Earth and the identification of metabolic processes that fuel biogeochemical cycling under extreme conditions. Here we present an analysis of the microbiomes of globally distributed hypersaline environments. We screened published metagenomes produced from a range of hypersaline environments (Marine salterns in Spain, hypersaline lakes in Chile and Antarctica, and soda lakes in Egypt and Mongolia [1–5]) for the presence, diversity, and abundance of shared functional genes that encode for the enzymes relevant to biogeochemical cycling. The study was expanded by generating metagenomes from DNA extracted from the salt and water of an Ethiopian hypersaline lake in the Dallol Depression. Analysis was performed to compare the functional gene profiles between the hypersaline environments. The microbial community within the Ethiopian Lake was comprised of Cyanobacteria, Candidate Phyla, and halophilic bacteria and archaea. Screening of the metagenomes identified that phototrophs in hypersaline environments typically possessed the majority of the genes relating to carbon dioxide and nitrogen fixation, indicating that they play a major role in driving both the carbon and nitrogen cycles [6-7]. High abundances of genes involved in denitrification, methylamine utilisation, and carbon monoxide oxidation classified as Halobacterial were also identified in all the metagenomes, indicating that these taxa are also key players in biogeochemical cycling in hypersaline environments [8-9]. Cultivation efforts are required to further define the interactions between the distinct functional clades identified in the hypersaline environments. References: 1. Zhao D, Zhang S, Xue Q, Chen J, Zhou J, Cheng F, et al. Front Microbiol. 2020;11(July):1–17. 2. Hagagy N, Hamedo H, Elshafi N, Selim S. Shotgun Metagenomic Sequencing of Extremophilic Community from Soda Lake, Ga’ar Lake, in Wadi Al-Natrun, Egyt. Egypt. J. Exp. Biol. (Bot.). 2021;1. 3. Fernandez AB, Ghai R, Martin-Cuadrado AB, Sanchez-Porro C, Rodriguez-Valera F, Ventosa A. Genome Announc. 2013;1(6). 4. Yau S, Lauro FM, Williams TJ, Demaere MZ, Brown M v., Rich J, et al. ISME Journal. 2013;7(10):1944–61. 5. Kurth D, Elias D, Rasuk MC, Contreras M, Farias ME. PLoS One. 2021;16:1–21. 6. Lay CY, Mykytczuk NCS, Yergeau É, Lamarche-Gagnon G, Greer CW, et al. Appl Environ Microbiol 2013;79:3637–3648. 7. Mehda S, Ángeles Muñoz-Martín M, Oustani M, Hamdi-Aïssa B, Perona E, et al. Microorganisms 2021;9:1–27. 8. Sorokin DY, Merkel AY, Messina E, Tugui C, Pabst M, et al. ISME J 2022;1–13. 9. King GM. Proc Natl Acad Sci 2003;51:278–291. Acknowledgements to the Europlanet Society, Science and Technology Facilities Council and the Research England Expanding Excellence in England (E3) fund for funding the research

Colour Peak: An analogue environment for late Noachian Mars

The martian surface cannot sustain liquid water today, but there is evidence water was present during the Noachian era. The transition of the martian climate into the Hesperian would have resulted in saline and sulfuric waters. Terrestrial analogue environments that possess a chemistry like these proposed waters can be used to develop an understanding of organisms that could have persisted. Here we present the chemistry and microbiome of Colour Peak, a sulfidic and saline spring system located within the Canadian High Arctic. Nucleic acids were extracted from the microbes in the sediments and the microbiome was characterised by the amplification and sequencing of 16S rRNA gene amplicons. The elemental composition of the fluids and sediment was determined by ICP-OES and compared with brines determined from the chemistry of the “Rocknest” sample at Yellowknife Bay, Gale Crater (Mars) by thermochemical modelling. Gibbs energy values were calculated from this fluid chemistry to identify potentially viable metabolisms. Analysis of the chemistries of the Colour Peak fluids confirmed a composition like the thermochemically modelled fluid, providing justification for the classification of Colour Peak as an appropriate analogue environment to investigate the habitability of former martian waters. Profiling of the Colour Peak microbial community revealed domination by bacteria associated with oxidation of reduced sulfur species and carbon dioxide fixation. Gibbs energy values calculated using the modelled martian fluid chemistry demonstrated that oxidation of reduced sulfur species was also viable in this chemical environment under aerobic and anaerobic conditions. These results demonstrate microbial sulfide oxidation is thermodynamically viable using both modelled and environmental proxies for former martian aqueous environments. This study highlights that metabolisms utilising the oxidation of reduced sulfur species could have been thermodynamically viable in ancient martian aqueous environments. Further work is needed to test this viability and the subsequent potential for biosignature formation