The Baikal Gigaton Volume Detector (Baikal-GVD) is a km
3
-scale neutrino detector currently under construction in Lake Baikal, Russia. The detector consists of several thousand optical sensors ...arranged on vertical strings, with 36 sensors per string. The strings are grouped into clusters of 8 strings each. Each cluster can operate as a stand-alone neutrino detector. The detector layout is optimized for the measurement of astrophysical neutrinos with energies of
∼
100 TeV and above. Events resulting from charged current interactions of muon (anti-)neutrinos will have a track-like topology in Baikal-GVD. A fast
χ
2
-based reconstruction algorithm has been developed to reconstruct such track-like events. The algorithm has been applied to data collected in 2019 from the first five operational clusters of Baikal-GVD, resulting in observations of both downgoing atmospheric muons and upgoing atmospheric neutrinos. This serves as an important milestone towards experimental validation of the Baikal-GVD design. The analysis is limited to single-cluster data, favoring nearly-vertical tracks.
The article presents the results of studies into the influence of various factors involved in a new elastic rolling process on residual stresses in the surface layer of high-precision non-rigid ...thin-walled parts. Modeling and optimization of the process are carried out to ensure maximum compressive residual stresses in the surface layers of equipment parts.
To improve the wear resistance of high-precision machine parts, a new technology has been developed: asymmetric uninterrupted lapping. The influence of its basic parameters on the surface ...microhardness is investigated. The optimal parameter values corresponding to maximum surface microhardness are determined.
—The influence of asymmetric uninterrupted lapping on the residual stress in the surface layer of the workpiece is investigated, with a view to increasing product strength.
The prototyping/early construction phase of the BAIKAL-GVD project Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Letnik:
742
Journal Article
Recenzirano
Odprti dostop
The prototyping phase of the BAIKAL-GVD project has been started in April 2011 with the deployment of a three string engineering array which comprises all basic elements and systems of the Gigaton ...Volume Detector (GVD) in Lake Baikal. In April 2012 the version of engineering array which comprises the first full-scale string of the GVD demonstration cluster had been deployed and operated during 2012. The first stage of the GVD-cluster which consists of three strings was deployed in April 2013. We review the prototyping phase of the BAIKAL-GVD project and describe the configuration and design of the 2013 engineering array.
External honing is a new approach improving the surface quality of thin-walled cylindrical parts for marine mechanisms. Its kinematic aspects and technological potential in machining high-precision ...parts are studied.
We present physical motivations and advantages of the new gamma-observatory TAIGA (Tunka Advanced Instrument for cosmic ray physics and gamma-ray astronomy). TAIGA will be located in the Tunka ...valley, 50km to the west of Lake Baikal, at the same place as the integrating air Cherenkov detector for cosmic rays Tunka-133. The TAIGA array is a complex, hybrid detector for ground-based gamma-ray astronomy for energies from a few TeV to several PeV as well as for cosmic ray studies from 100TeV to several EeV. The array will consist of a wide angle Cherenkov array – TAIGA-HiSCORE with 5km2 area, a net of 16 IACT telescopes (with FOV of about 9.72°×9.72°) as well as muon and other detectors. We present the current status of the array construction.
Naphthalene, as a component of crude oil, is a common environmental pollutant. Biochemical and genetic aspects of naphthalene catabolism have been examined in most detail in the bacteria of
...Pseudomonas
genus. In pseudomonads, the key intermediate in naphthalene degradation is salicylate. In this study, we investigated the ability of
Rhodococcus opacus
strain 3D to utilize naphthalene as a sole carbon and energy source. The characteristic feature of this strain is the inability to grow in the mineral medium supplemented with salicylate (typical intermediate of naphthalene degradation in Gram-negative bacteria). The absence of salicylate hydroxylase activity and salicylate accumulation in the course of
R. opacus
3D cultivation in the mineral medium supplemented with naphthalene indicated existence of an alternative pathway of naphthalene oxidation. At the same time,
R. opacus
3D was able to use monoaromatic compounds (salts of gentisic,
ortho-
phthalic, and 2-hydroxycinnamic acids and coumarin) as growth substrates. Based on the analysis of enzymatic activities, identification of the reaction intermediates, genetic determinants, and growth substrates, we concluded that
R. opacus
3D carries out naphthalene degradation through an alternative pathway via formation of ortho-phthalic acid, which is untypical for pseudomonads. Using mass spectrometry, we showed for the first time that salicylic acid associate formed in trace amounts in the process of naphthalene degradation is not further metabolized and accumulated in the growth medium in a form of a dimer.
ABSTRACT
Baikal-GVD has recently published its first measurement of the diffuse astrophysical neutrino flux, performed using high-energy cascade-like events. We further explore the Baikal-GVD cascade ...data set collected in 2018–2022, with the aim to identify possible associations between the Baikal-GVD neutrinos and known astrophysical sources. We leverage the relatively high angular resolution of the Baikal-GVD neutrino telescope (2–3 deg.), made possible by the use of liquid water as the detection medium, enabling the study of astrophysical point sources even with cascade events. We estimate the telescope’s sensitivity in the cascade channel for high-energy astrophysical sources and refine our analysis prescriptions using Monte-Carlo simulations. We primarily focus on cascades with energies exceeding 100 TeV, which we employ to search for correlation with radio-bright blazars. Although the currently limited neutrino sample size provides no statistically significant effects, our analysis suggests a number of possible associations with both extragalactic and Galactic sources. Specifically, we present an analysis of an observed triplet of neutrino candidate events in the Galactic plane, focusing on its potential connection with certain Galactic sources, and discuss the coincidence of cascades with several bright and flaring blazars.
PDF
