Status of the Baikal-GVD Neutrino Telescope Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
EPJ Web of Conferences,
2019, Letnik:
207
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Currently in Lake Baikal a new-generation neutrino telescope is being deployed: Baikal-GVD, a deep underwater Cherenkov detector on the cubic-kilometer scale. This paper presents the status of the ...detector implementation and the first physical results obtained with the existing configuration.
The Baikal-GVD project aims to create a deep-water neutrino telescope on a cubic kilometer scale in Lake Baikal. The telescope is at the rollout stage; its effective volume for detecting showers from ...high-energy neutrinos of an astrophysical nature has reached 0.25 km
3
. A set of experimental data on the telescope has been acquired since 2015 in the constant exposure mode simultaneously with the build-up of the detector. This article is devoted to the calibration of the measuring system of the neutrino telescope. It presents the equipment of the calibration system, describes the calibration procedure, and discusses the issues of the accuracy, reliability, and effectiveness of the developed calibration procedures.
We present data on the luminescence of the Baikal water medium collected with the Baikal-GVD neutrino telescope. This three-dimensional array of light sensors allows the observation of time and ...spatial variations of the ambient light field. In 2016, we observed a maximum of luminescence activity between July and October.
Baikal-GVD: cascades Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
EPJ Web of Conferences,
2019, Letnik:
207
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Baikal-GVD is a next generation, kilometer-scale neutrino telescope currently under construction in Lake Baikal. GVD is formed by multi-megaton subarrays (clusters) and is designed for the detection ...of astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. The design of Baikal-GVD allows one to search for astrophysical neutrinos with flux values measured by IceCube already at early phases of the array construction. We present here preliminary results of the search for high-energy neutrinos via the cascade mode obtained in 2015 and 2016.
Present day biomedical applications, including magnetic biosensing, demand better understanding of the interactions between living systems and magnetic nanoparticles (MNPs). In this work spherical ...MNPs of maghemite were obtained by a highly productive laser target evaporation technique. XRD analysis confirmed the inverse spinel structure of the MNPs (space group Fd-3m). The ensemble obeyed a lognormal size distribution with the median value 26.8 nm and dispersion 0.362. Stabilized water-based suspensions were fabricated using electrostatic or steric stabilization by the natural polymer chitosan. The encapsulation of the MNPs by chitosan makes them resistant to the unfavorable factors for colloidal stability typically present in physiological conditions such as pH and high ionic force. Controlled amounts of suspensions were used for in vitro experiments with human blood mononuclear leukocytes (HBMLs) in order to study their morphofunctional response. For sake of comparison the results obtained in the present study were analyzed together with our previous results of the study of similar suspensions with human mesenchymal stem cells. Suspensions with and without chitosan enhanced the secretion of cytokines by a 24-h culture of HBMLs compared to a control without MNPs. At a dose of 2.3, the MTD of chitosan promotes the stimulating effect of MNPs on cells. In the dose range of MNPs 10-1000 MTD, chitosan "inhibits" cellular secretory activity compared to MNPs without chitosan. Both suspensions did not caused cell death by necrosis, hence, the secretion of cytokines is due to the enhancement of the functional activity of HBMLs. Increased accumulation of MNP with chitosan in the cell fraction at 100 MTD for 24 h exposure, may be due to fixation of chitosan on the outer membrane of HBMLs. The discussed results can be used for an addressed design of cell delivery/removal incorporating multiple activities because of cell capability to avoid phagocytosis by immune cells. They are also promising for the field of biosensor development for the detection of magnetic labels.
Biomedical engineering is the most promising field for the application of ferrogels as scaffolds for cell culturing in regenerative medicine, targeted drug delivery, and biosensorics. This study is ...focused on the contribution of ferric-oxide magnetic nanoparticles (MNPs) to the biocompatibility of ferrogels with human dermal fibroblasts. The results of experiments with polyacrylamide gels filled with MNPs are presented. These experiments demonstrate that, regardless of the mechanical and electrical characteristics of ferrogels, MNPs have a significant effect on the biological activity of cells.
In order to elucidate the mechanism of the flavonoid taxifolin (dihydroquercetin) oxidation under the electrochemical experiment conditions in the aqueous solutions the chronoamperometry and bulk ...electrolysis with following characterization of the oxidation products by means of the HPLC with both UV–vis and MS detection have been coupled. The taxifolin diffusion coefficient has been evaluated in the aqueous solution as 3.63 × 10−6 cm2/s. The experimentally obtained number of electrons per one taxifolin molecule falls between 2 and 3 demonstrating that under electrochemical oxidation conditions only part of initially oxidized taxifolin molecules participates in dimerization and further transformation.
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•The taxifolin electrochemical oxidation leads to the di- and trimer formation in solutions.•The number of transferred electrons increases due to the di- and trimers further electrooxidation.•The diffusion coefficient of taxifolin has been evaluated in the aqueous solution.
The present work demonstrates the potential applicability of additive manufacturing to X-Ray refractive nano-lenses. A compound refractive lens with a radius of 5 µm was produced by the two-photon ...polymerization induced lithography. It was successfully tested at the X-ray microfocus laboratory source and a focal spot of 5 μm was measured. An amorphous nature of polymer material combined with the potential of additive technologies may result in a significantly enhanced focusing performance compared to the best examples of modern X-ray compound refractive lenses.
Reconstructed tracks of muons produced in neutrino interactions provide the precise probe for the neutrino direction. Therefore, track-like events are a powerful tool to search for neutrino point ...sources. Recently, Baikal-GVD has demonstrated the first sample of low-energy neutrino candidate events extracted from the data of the season 2019 in a so-called single-cluster analysis - treating each cluster as an independent detector. In this paper, the extension of the track-like event analysis to a wider data set is discussed and the first high-energy track-like events are demonstrated. The status of multi-cluster track reconstruction and that of the event analysis are also discussed.
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