Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Digital watermarks in electronic document circulation

This paper reviews different protection methods for electronic documents, their good and bad qualities. Common attacks on electronic documents are analyzed. Digital signature and ways of eliminating its flaws are studied. Different digital watermark embedding methods are described, they are divided into 2 types. The solution to protection of electronic documents is based on embedding digital watermarks. Comparative analysis of this methods is given. As a result, the most convenient method is suggested – reversible data hiding. It’s remarked that this technique excels at securing the integrity of the container and its digital watermark. Digital watermark embedding system should prevent illegal access to the digital watermark and its container. Digital watermark requirements for electronic document protection are produced. Legal aspect of copyright protection is reviewed. Advantages of embedding digital watermarks in electronic documents are produced. Modern reversible data hiding techniques are studied. Distinctive features of digital watermark use in Russia are highlighted. Digital watermark serves as an additional layer of defense, that is in most cases unknown to the violator. With an embedded digital watermark, it’s impossible to misappropriate the authorship of the document, even if the intruder signs his name on it. Therefore, digital watermarks can act as an effective additional tool to protect electronic documents

Heat and mass transfer in laminated glued timber bar

The main prerequisites for the development of wooden housing construction in Russia are given, which determined the goal of this study - to develop a mathematical model of heat and mass transfer (moisture transfer) in glued timber for rational design of enclosing structures. Lamellas can be classified as a capillary ‒ porous body. leaning on theory of academician A.V. Lykov, the formulation of the problem of heat and mass transfer in a multilayer glued laminated timber is presented a system of equations describing non-stationary heat, mass and pressure transfer under real possible operating conditions of enclosing structures is considered. An analytical method is proposed for calculating both individual lamellas and the entire multilayer glued beam. The proposed technique allows the method of solving the inverse problem to directly calculate the resistance value of the entire bar from the unsteady temperature field. The system of equations describing the process is nonlinear and analytically insoluble. To solve the problem, a combined method for solving boundary value problems of heat transfer was used, which is based on a combination of elements of analytical and numerical solutions. A feature of the problem under consideration is that the middle lamella has heat-conducting inclusions in the form of a bough. Method is that the entire heat transfer process is divided into a number of small time intervals. Within each interval, we assume that the temperature is constant at the interface between layers and a constant heat flux through the contacting surfaces, i.e. perfect thermal contact

Undercurrents in the Northeastern Black Sea Detected on the Basis of Multi-Model Experiments and Observations

Numerical simulation results of the Black Sea circulation obtained by four ocean dynamics models are compared to each other and to in situ data in order to determine the features of the Black Sea deep-water circulation such as deep-water undercurrents. The year 2011 is chosen as the test period due to the availability of deep-sea observations, including ARGO profiles and ADCP current velocities. Validation of the simulation results is based on comparison with the temperature and salinity measured by the ARGO floats. Anticyclonic currents (undercurrents) under the cyclonic Rim Current are detected by the results of all numerical models near the North Caucasian coast. The main characteristics of undercurrents are consistent with in situ data on current velocity up to a depth of 1000 m obtained by the Aqualog probe at the IO RAS test site near Gelendzhik in June 2011. The analysis of the spatio-temporal variability of the modeled salinity and velocity fields reveals that the most probable origin of the undercurrents is the horizontal density gradient of seawater in the region

Contributing to Biochemistry and Optoelectronics: Pyrrolo[1′,2′:2,3]imidazo[1,5-a]indoles and Cyclohepta[4,5]pyrrolo[1,2-c]pyrrolo[1,2-a]imidazoles via [3+2] Annulation of Acylethynylcycloalka[b]pyrroles with Δ1-Pyrrolines

Available pyrrolylalkynones with tetrahydroindolyl, cycloalkanopyrrolyl, and dihydrobenzo[g]indolyl moieties, acylethynylcycloalka[b]pyrroles, are readily annulated with Δ1-pyrrolines (MeCN/THF, 70 °C, 8 h) to afford a series of novel pyrrolo[1′,2′:2,3]imidazo[1,5-a]indoles and cyclohepta[4,5]pyrrolo[1,2-c]pyrrolo[1,2-a]imidazoles functionalized with an acylethenyl group in up to an 81% yield. This original synthetic approach contributes to the arsenal of chemical methods promoting drug discovery. Photophysical studies show that some of the synthesized compounds, e.g., benzo[g]pyrroloimidazoindoles, are prospective candidates for TADF emitters of OLED

Structure and Relaxor Behavior of (0.5 − <i>x</i>)BiFeO₃-0.5PbFe_0.5Nb_0.5O₃-<i>x</i>PbTiO₃ Ternary Ceramics

Ceramics of the quasi-binary concentration section (0.1 ≤ x ≤ 0.2, Δx = 0.025) of the ternary solid solution system (0.5 − x)BiFeO3-0.5PbFe0.5Nb0.5O3-xPbTiO3 were prepared by the conventional solid-phase reaction method. An X-ray study at different temperatures revealed that (0.5 − x)BF-0.5PFN-xPT ceramics have a cluster morphology. Clusters have different modulation, crystal lattice symmetry, and chemical composition. The presence of a cluster structure in a solid solution with heterovalent substitution, consisting of regions rich in Ti+4, Nb+5, or Fe3+, has led to the appearance of Maxwell–Wagner polarization in the studied ceramics. The study of the dielectric characteristics revealed the relaxor-like behavior of the studied ceramics. The grain morphology, dielectric, pyroelectric, and piezoelectric properties of the selected solid solutions were investigated. The highest piezoelectric coefficient, d33 = 280 pC/N, was obtained in the 0.3BiFeO3-0.5PbFe0.5Nb0.5O3-0.2PbTiO3 ceramics. Study of the dielectric characteristics of all samples revealed relaxor ferroelectric behavior and a region of diffuse phase transition from the paraelectric to ferroelectric phase in the temperature range of 140–170 °C

Mass Testing and Characterization of 20-inch PMTs for JUNO

Main goal of the JUNO experiment is to determine the neutrino mass ordering using a 20kt liquid-scintillator detector. Its key feature is an excellent energy resolution of at least 3 % at 1 MeV, for which its instruments need to meet a certain quality and thus have to be fully characterized. More than 20,000 20-inch PMTs have been received and assessed by JUNO after a detailed testing program which began in 2017 and elapsed for about four years. Based on this mass characterization and a set of specific requirements, a good quality of all accepted PMTs could be ascertained. This paper presents the performed testing procedure with the designed testing systems as well as the statistical characteristics of all 20-inch PMTs intended to be used in the JUNO experiment, covering more than fifteen performance parameters including the photocathode uniformity. This constitutes the largest sample of 20-inch PMTs ever produced and studied in detail to date, i.e. 15,000 of the newly developed 20-inch MCP-PMTs from Northern Night Vision Technology Co. (NNVT) and 5,000 of dynode PMTs from Hamamatsu Photonics K. K.(HPK)

The JUNO experiment Top Tracker

20 pagesInternational audienceThe main task of the Top Tracker detector of the neutrino reactor experiment Jiangmen Underground Neutrino Observatory (JUNO) is to reconstruct and extrapolate atmospheric muon tracks down to the central detector. This muon tracker will help to evaluate the contribution of the cosmogenic background to the signal. The Top Tracker is located above JUNO's water Cherenkov Detector and Central Detector, covering about 60% of the surface above them. The JUNO Top Tracker is constituted by the decommissioned OPERA experiment Target Tracker modules. The technology used consists in walls of two planes of plastic scintillator strips, one per transverse direction. Wavelength shifting fibres collect the light signal emitted by the scintillator strips and guide it to both ends where it is read by multianode photomultiplier tubes. Compared to the OPERA Target Tracker, the JUNO Top Tracker uses new electronics able to cope with the high rate produced by the high rock radioactivity compared to the one in Gran Sasso underground laboratory. This paper will present the new electronics and mechanical structure developed for the Top Tracker of JUNO along with its expected performance based on the current detector simulation