99 research outputs found

    Spectral shaping of lasing active medium with agglomerated nanoparticles of metals and dielectrics

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    In this paper presented a series of experiments determine the spectral characteristics of random lasing in lasers with agglomerated nanoparticles metals and dielectrics. The data allowed us to establish that, in the active heterogeneous environment, there are various gain effects of lasing the impact of which is determined nanoparticles concentration

    Threshold characteristics cavityless lasing in composites with agglomerated metal and dielectric nanoparticles

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    The paper presents results of experimental studies of the threshold characteristics of lasing in thin layers (20 microns) of a solution of rhodamine 6G with agglomerates of metal and dielectric nanoparticles. The maximum decrease in the lasing threshold was more than two orders for a wide range of changes in the concentration of metal agglomerates. For dielectric nanoparticle agglomerates range of maximum lowering of the threshold is 5 times lower. This is due to different mechanisms of formation of lasing in these environments.Comparing the efficiency of lasing in layers with metal agglomerates proves on expediency using them to create a low threshold microlasers

    Sobemovirus genome appears to encode a serine protease related to cysteine proteases of picornaviruses

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    AbstractA putative serine protease was identified among non-structural proteins of southern bean mosaic virus (SBMV) by sequence comparison with cellular and viral proteases. The predicted SBMV proteased is played a significant similarity to cysteine proteases of picornaviruses, providing a possible evolutionary link between the two enzyme classes. It is suggested that SBMV follows the general expression strategy characteristic of other positive-strand RNA viruses containing 5′-terminal covalently linked proteins (VPg), i.e. generation of functional proteins by polyprotein processing

    The influence of plasmon resonance on the decrease of resonatorless laser generation thresholds

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    The paper presents the results of the measurements of the values of resonatorless laser generation power threshold densities in thin layers of 6G rhodamine colloidal solutions with single plasmon-resonance gold and silver nanoparticles and non-plazmon resonance nanoparticles of platinum and zinc oxide. It is shown that when gold, platinum and silver nanoparticles are used, the thresholds values are approximately equal at the same concentrations. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    The influence of plasmon resonance on the decrease of resonatorless laser generation thresholds

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    The paper presents the results of the measurements of the values of resonatorless laser generation power threshold densities in thin layers of 6G rhodamine colloidal solutions with single plasmon-resonance gold and silver nanoparticles and non-plazmon resonance nanoparticles of platinum and zinc oxide. It is shown that when gold, platinum and silver nanoparticles are used, the thresholds values are approximately equal at the same concentrations. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

    Model for the assessment greenhouse gas emissions from road transport

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    A three-level model for estimating greenhouse gas (GHG) emissions by mobile and stationary road transport facilities of a state or region, proposed in this article, takes account into GHG emissions from a vehicle fleet (mobile objects) and road transport infrastructure (network of car services, road network of various categories). Additionally, it has been developed the intellectual system which evaluates the reliability of the array of initial data, by increasing the range and adjusting (if necessary) the values of individual indicators, as the result we achieving the convergence of the calculating GHG emissions from motor vehicles according to the models of all three levels of assessment. This ensures verification of the obtained gross GHG emissions. Evaluation of greenhouse gas emissions using three-level model was carried out for St. Petersburg and the Leningrad Region (Russian Federation), they shown the possibility of reducing by 2030 by 3.2 ... 12.4% of gross GHG emissions by motor transport of the Russian Federation in comparison with 2015. For St. Petersburg and the Leningrad Region, both the reduction of gross GHG emissions by road transport (12.7% innovative scenario) and their growth (4.8% inertial scenario) are expected during the forecast period. At the same time, both for the St. Petersburg and the Leningrad Region and for the state as a whole, a significant reduction in gross GHG emissions by road transport is expected in the period after 2025 due to the intensive replacement of cars on oil fuel by electric vehicles and hybrids, changes in the transport behavior of the population, the development of public passenger transport and cycling, the introduction of autonomous vehicles, etc

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    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

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    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

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

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    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 30MM_{\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
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