Investigation of the process of recrystallization calcium carbonate microparticles grown on polycaprolactone nanofibers using scanning electron microscopy and X-ray diffraction

Background and Objectives: A method for the mineralization of polycaprolactone nanofibers with microparticles of calcium carbonate (vaterite) is presented. The proposed composite material can be used as a tissue engineering scaffold and a drug delivery vehicle for regenerative medicine. Materials and Methods: The process of recrystallization of vaterite microparticles formed on polycaprolactone fibers into calcite is studied using scanning electron microscopy and X-ray diffraction. Results: The dependences of the mass and quantitative fractions of vaterite/calcite microparticles depending on the duration of the experiment have been compared. Conclusion: The total recrystallization time for vaterite microparticles with an average diameter of 1.2 ± 0.4 microns is 24 hours, and the effective time of their use as a container for targeted drug delivery is limited to 18 hours

Investigation of the recrystallization process of vaterite microparticles containing magnetite nanoparticles grown on polycaprolactone fibers by ultrasonic treatment

Background and Objectives. A method for mineralizing polycaprolactone nanofibers by calcium carbonate (vaterite) microparticles containing nanoparticles of mixed iron oxide (magnetite) using the ultrasonic treatment is proposed. Materials and Methods: The process of recrystallization vaterite microparticles, which are part of the composite material, into calcite using X-ray diffraction and scanning electron microscopy was studied. Results: The resulting composite material can be used in tissue engineering as either a scaffold for cell growth or a drug carrier for their local release. Conclusion: It has been found that the complete process of recrystallization of vaterite into calcite takes about 27 hours, while the recrystallization rate increases significantly after 12 hours of exposure to water. According to X-ray diffraction data, there are no magnetic nanoparticles in the resulting coating by 24 o’clock. This is due to their gradual release as a result of the recrystallization of vaterite into calcite

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

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

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

JUNO Sensitivity to Invisible Decay Modes of Neutrons

We explore the bound neutrons decay into invisible particles (e.g., $n\rightarrow 3 \nu$ or $nn \rightarrow 2 \nu$) in the JUNO liquid scintillator detector. The invisible decay includes two decay modes: $n \rightarrow { inv}$ and $nn \rightarrow { inv}$. The invisible decays of $s$-shell neutrons in $^{12}{\rm C}$ will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino $\bar{\nu}_e$, natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are $\tau/B( n \rightarrow { inv} ) > 5.0 \times 10^{31} \, {\rm yr}$ and $\tau/B( nn \rightarrow { inv} ) > 1.4 \times 10^{32} \, {\rm yr}$.Comment: 28 pages, 7 figures, 4 table

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

JPEG digital watermarking for copyright protection

With the rapid growth of the multimedia technology, copyright protection has become a very important issue, especially for images. The advantages of easy photo distribution are discarded by their possible theft and unauthorized usage on different websites. Therefore, there is a need in securing information with technical methods, for example digital watermarks. This paper reviews digital watermark embedding methods for image copyright protection, advantages and disadvantages of digital watermark usage are produced. Different watermarking algorithms are analyzed. Based on analysis results most effective algorithm is chosen – differential energy watermarking. It is noticed that the method excels at providing image integrity. Digital watermark embedding system should prevent illegal access to the digital watermark and its container. Requirements for digital watermark are produced. Possible image attacks are reviewed. Modern modifications of embedding algorithms are studied. Robustness of the differential energy watermark is investigated. Robustness is a special value, which formulae is given further in the article. DEW method modification is proposed, it’s advantages over original algorithm are described. Digital watermark serves as an additional layer of defense which is in most cases unknown to the violator. Scope of studied image attacks includes compression, filtration, scaling. In conclusion, it’s possible to use DEW watermarking in copyright protection, violator can easily be detected if images with embedded information are exchanged

ANALYSIS OF TECHNOLOGIES AND TECHNICAL MEANS FOR SOWING FOREST SEEDS IN NURSERIES

The analysis of sowing methods and existing types of seeders, which are used in forestry and agrotechnical complexes, as well as patent materials, is given. Analysis of domestic designs of SLP-M, SLU-5-20 and "Litva-25" seeders, intended for sowing small forest seeds in nurseries and open ground, showed that they are energy-intensive and do not always ensure the embedding of seeds in moist soil. The perspective directions of resource conservation in agriculture have been considered: sowing using "no-till" or "mini-do" technology, ensuring sowing of seeds in untreated and minimally cultivated soil. The combined seeder AGRATORDK is equipped with a disc cultivator and a seeder with gouters. The RAPIDRDA-450S seeder from VADERSTAD has spherical discs that cultivate soil in one pass. The presented methods of sowing and seeding devices have a significant drawback - the necessity of additional working bodies with a high probability of getting into the grooves of dry soil, moving the top layer of soil "back and forth." A gouter which can change the angle of entering the soil and planting depths of small forest seeds was developed. Preliminary laboratory studies have shown the operability of gouter mock-up specimen and the ability to cut the seed furrow by cutting out a layer of soil with void formation above the bottom of the seed furrow, into which seeds were fed through tubes from funnels. The seeds were embedded with a layer of soil under the influence of its own gravity</jats:p