Publications by authors named "Konstantin Stepanov"

4 Publications

  • Page 1 of 1

Sensitivity Improvement of Phi-OTDR by Fiber Cable Coils.

Sensors (Basel) 2021 Oct 26;21(21). Epub 2021 Oct 26.

Bauman Moscow State Technical University, 2-nd Baumanskaya 5-1, 105005 Moscow, Russia.

We present a theoretical and experimental study in which we increased the sensitivity of a phase-sensitive optical time-domain reflectometer (phi-OTDR). This was achieved by constructing coils in the sensor cable, which increased the total amplitude of the impact on the fiber. We demonstrate this theoretically using the example of a phase-sensitive reflectometer model and practically in testing grounds with a buried nearby conventional sensor and a sensor with coils. The sensitivity increased 2.2 times. We detected 95% of events when using coils, versus 20% when using a straight cable. The suggested method does not require any modifications to the device.
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http://dx.doi.org/10.3390/s21217077DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8587439PMC
October 2021

Serological Evidence of Hepatitis E Virus Circulation Among Reindeer and Reindeer Herders.

Vector Borne Zoonotic Dis 2021 Jul 19;21(7):546-551. Epub 2021 May 19.

Mechnikov Research Institute for Vaccines and Sera, Moscow, Russia.

Various deer species are infected with hepatitis E virus (HEV) and may be a source of zoonotic infection for humans. So far, HEV has not been isolated from reindeer and the role of this domesticated deer species in HEV transmission is unknown. We tested serum samples from 191 reindeer () and 86 adult reindeer herders from the circumpolar regions of Yakutia (Russian Federation) for anti-HEV and HEV RNA. Anti-HEV IgG prevalence was 12.0% (95% confidence interval [95% CI]: 8.1-17.5) in reindeer and 4.7% (95% CI: 1.5-11.7) in reindeer herders. The latter was similar to the positivity rate observed in adult residents of the city of Yakutsk, the capital of Yakutia, who do not have routine contact with reindeer (3.7% [19/519, 95% CI: 2.3-5.7]). No samples positive for HEV RNA were identified. The study provides evidence of HEV circulation in reindeer. Nevertheless, the low seroprevalence in reindeer herders indicate a low risk of zoonotic HEV infection.
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http://dx.doi.org/10.1089/vbz.2020.2727DOI Listing
July 2021

The Sensitivity Improvement Characterization of Distributed Strain Sensors Due to Weak Fiber Bragg Gratings.

Sensors (Basel) 2020 Nov 11;20(22). Epub 2020 Nov 11.

Kotelnikov Institute of Radioengineering and Electronics of RAS, Mokhovaya 11-7, 125009 Moscow, Russia.

Weak fiber Bragg gratings (WFBGs) in a phase-sensitive optical time-domain reflectometer (phi-OTDR) sensor offer opportunities to significantly improve the signal-to-noise ratio (SNR) and sensitivity of the device. Here, we demonstrate the process of the signal and noise components' formation in the device reflectograms for a Rayleigh scattering phi-OTDR and a WFBG-based OTDR. We theoretically calculated the increase in SNR when using the same optical and electrical components under the same external impacts for both setups. The obtained values are confirmed on experimental installations, demonstrating an improvement in the SNR by about 19 dB at frequencies of 20, 100, and 400 Hz. In this way, the minimum recorded impact (at the threshold SNR = 10) can be reduced from 100 nm per 20 m of fiber to less than 5 nm per 20 m of fiber sensor.
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http://dx.doi.org/10.3390/s20226431DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698298PMC
November 2020

Symposium report: emerging threats for human health - impact of socioeconomic and climate change on zooanthroponosis in the Republic of Sakha (Yakutia), Russia.

Int J Circumpolar Health 2020 12;79(1):1715698

Yakut State Agricultural Academy, Yakutsk, Russian Federation.

Population growth, socio-cultural and economic changes as well as technological progress have an immediate impact on the environment and human health in particular. Our steadily rising needs of resources increase the pressure on the environment and narrow down untainted habitats for plants and wild animals. Balance and resilience of ecosystems are further threatened by climate change, as temperature and seasonal shifts increase the pressure for all species to find successful survival strategies. Arctic and subarctic regions are especially vulnerable to climate change, as thawing of permafrost significantly transforms soil structures, vegetation and habitats. With rising temperature, the risk of zoonotic diseases in the Republic of Sakha (Yakutia) has also increased. As vegetation periods prolong and habitats broaden, zoonotic pathogens and their vectors find more favourable living conditions. Moreover, permafrost degradation may expose historic burial grounds and allow for reviving the vectors of deadly infections from the past. To assess the current state of knowledge and emerging risks in the light of the "One Health" concept, a German-Russian Symposium took place on 13 August 2018 in Yakutsk, Russian Federation. This symposium report presents the main findings generated from presentations and discussions.
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http://dx.doi.org/10.1080/22423982.2020.1715698DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7034492PMC
December 2020
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