14,640 research outputs found

    Practical use of reactor anti-neutrinos for nuclear safeguard in Vietnam

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    One of the most abundant man-made sources of low energy (few~MeVs) neutrinos, reactor neutrino, is not only useful for studying neutrino properties, but it is also used in practical applications. In this study, we investigate the practical use of reactor neutrino detectors for nuclear safeguard in Vietnam, specifically at the Dalat Nuclear Reactor, a future research facility, and presumably commercial reactors with 500~kW, 10~MW, and 1000~MW thermal powers, respectively. We compute the rate of observed inverted beta decay events, as well as the statistical significance of extracting isotope composition under the practical assumptions of detector mass, detection efficiency, and background level. We find that a 1-ton detector mass can allow us to detect the reactor's on-off transition state from a few hours to a few days, depending on the standoff distance and reactor thermal power. We investigate how background and energy resolution affect the precision of the extracted weapon-usable 239Pu{}^{239}\text{Pu} isotope. We conclude that in order to distinguish the 10\% variation of the 239Pu{}^{239}\text{Pu} in the 10~MW thermal power reactor, a 1-ton detector placed 50~m away must achieve 1\% background level. Increasing the statistics by using a 10x larger detector or placing it 10\sqrt{10} times closer to the reactor alleviates the requirement of the background level to 10\%

    Stringent constraint on CPT violation with the synergy of T2K-II, NOν\nuA extension, and JUNO

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    Neutrino oscillation experiments have measured precisely the mass-squared differences of three neutrino mass eigenstates, and three leptonic mixing angles by utilizing both neutrino and anti-neutrino oscillations. The possible CPT violation may manifest itself in the difference of neutrino and anti-neutrino oscillation parameters, making these experiments promising tools for testing CPT invariance. We investigate empirically the sensitivity of the CPT test via the difference in mass-squared splittings (Δm312−Δm‾312\Delta m^2_{31} - \Delta \overline{m}^2_{31}) and in leptonic mixing angles (sin⁡2θ23−sin⁡2θ‾23\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}) with the synergy of T2K-II, NOν\nuA extension, and JUNO experiments. If the CPT symmetry is found to be conserved, the joint analysis of the three experiments will be able to establish limits of ∣Δm312−Δm‾312∣|\Delta m^2_{31} - \Delta \overline{m}^2_{31}| < 5.3×10−3eV25.3\times 10^{-3} \text{eV}^2 and ∣sin⁡2θ23−sin⁡2θ‾23∣|\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}| < 0.100.10 at 3σ\sigma C. L. on the possible CPT violation. We find that with (Δm312−Δm‾312\Delta m^2_{31} - \Delta \overline{m}^2_{31}), the dependence of the statistical significance on the relevant parameters to exclude the CPT conservation is marginal, and that, if the difference in the best-fit values of Δm312\Delta m^2_{31} and Δm‾312\Delta \overline{m}^2_{31} measured by MINOS(+) and NOν\nuA persists as the true, the combined analysis will rule out the CPT conservation at 4σ\sigma C. L.. With the (sin⁡2θ23−sin⁡2θ‾23\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}), the statistical significance to exclude CPT invariance depends strongly on the true value of θ23(θ‾23)\theta_{23}(\overline{\theta}_{23}). In case of maximal mixing of θ23\theta_{23}, the CPT conservation will be excluded at 3σ\sigma C. L. or more if the difference in the best-fit values of θ23\theta_{23} and θ‾23\overline{\theta}_{23} remains as the true.Comment: 10 pages, 10 figure

    Designing a novel heterostructure AgInS<sub>2</sub>@MIL-101(Cr) photocatalyst from PET plastic waste for tetracycline degradation

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    Semiconductor-containing porous materials with a well-defined structure could be unique scaffolds for carrying out selective organic transformations driven by visible light. We herein introduce for the first time a heterostructure of silver indium sulfide (AgInS(2)) ternary chalcogenide and a highly porous MIL-101(Cr) metal–organic framework (MOF) synthesised from polyethylene terephthalate plastic waste. Our results demonstrate that AgInS(2) nanoparticles were uniformly attached to each lattice plane of the octahedral MIL-101(Cr) structure, resulting in a nanocomposite with a high distribution of semiconductors in a porous media. We also demonstrate that the nanocomposite with up to 40% of AgInS(2) doping exhibited excellent catalytic activity for tetracycline degradation under visible light irradiation (∼99% tetracycline degraded after 4 h) and predominantly maintained its performance after five cycles. These results could promote a new material circularity pathway to develop new semiconductors that can be used to protect water from further pollution

    Development of metal adaptation in a tropical marine zooplankton

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    Simulating chemistry efficiently on fault-tolerant quantum computers

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    Quantum computers can in principle simulate quantum physics exponentially faster than their classical counterparts, but some technical hurdles remain. Here we consider methods to make proposed chemical simulation algorithms computationally fast on fault-tolerant quantum computers in the circuit model. Fault tolerance constrains the choice of available gates, so that arbitrary gates required for a simulation algorithm must be constructed from sequences of fundamental operations. We examine techniques for constructing arbitrary gates which perform substantially faster than circuits based on the conventional Solovay-Kitaev algorithm [C.M. Dawson and M.A. Nielsen, \emph{Quantum Inf. Comput.}, \textbf{6}:81, 2006]. For a given approximation error Ͼ\epsilon, arbitrary single-qubit gates can be produced fault-tolerantly and using a limited set of gates in time which is O(log⁥Ͼ)O(\log \epsilon) or O(log⁥log⁥Ͼ)O(\log \log \epsilon); with sufficient parallel preparation of ancillas, constant average depth is possible using a method we call programmable ancilla rotations. Moreover, we construct and analyze efficient implementations of first- and second-quantized simulation algorithms using the fault-tolerant arbitrary gates and other techniques, such as implementing various subroutines in constant time. A specific example we analyze is the ground-state energy calculation for Lithium hydride.Comment: 33 pages, 18 figure

    Domain Wall Resistance based on Landauer's Formula

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    The scattering of the electron by a domain wall in a nano-wire is calculated perturbatively to the lowest order. The resistance is calculated by use of Landauer's formula. The result is shown to agree with the result of the linear response theory if the equilibrium is assumed in the four-terminal case

    Effect of a Domain Wall on the Conductance Quantization in a Ferromagnetic Nanowire

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    The effect of the domain wall (DW) on the conductance in a ballistic ferromagnetic nanowire (FMNW) is revisited by exploiting a specific perturbation theory which is effective for a thin DW; the thinness is often the case in currently interested conductance measurements on FMNWs. Including the Hund coupling between carrier spins and local spins in a DW, the conductance of a FMNW in the presence of a very thin DW is calculated within the Landauer-B\"{u}ttiker formalism. It is revealed that the conductance plateaus are modified significantly, and the switching of the quantization unit from e2/he^2/h to ``about 2e2/h2e^2/h'' is produced in a FMNW by the introduction of a thin DW. This accounts well for recent observations in a FMNW.Comment: 5 pages, 2 figures, Corrected typos and added reference

    A comprehensive study in efficacy of Vietnamese herbal extracts on whiteleg shrimp (<em>Penaeus vannamei</em>) against <em>Vibrio parahaemolyticus</em> causing acute hepatopancreatic necrosis disease (AHPND)

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    Traditional Vietnamese herbal species were examined for their antimicrobial activity and disease resistance in whiteleg shrimp. In-vitro screening, the extracts of ten herbs were conducted to test the inhibition ability against Vibrio parahaemolyticus, causing acute hepatopancreatic necrosis disease. The results showed that five out of ten herbal species, including Pithecellobium dulce, Melaleuca leucadendron, Eucalyptus globulus, Mimosa pirga, and Hibiscus sabdariffa displayed potent antibacterial activity. Besides, three types of extracts of H. sabdariffa, E. globulus, and M. pirga were coated to the pellet feed at a concentration of 1%. After 30 days of feeding, the whiteleg shrimp (Penaeus vannamei) were challenged by V. parahaemolyticus through immersion. The growth performance (such as growth rate in length and weight, survival rate), hematological parameters of total hemocytes (THC), hyaline hemocytes (HC), and granulocytes (GC), and hepatopancreas recovery under the treatments with herbal extracts of the whiteleg shrimp were significantly enhanced as compared with the control (without herbal extract). The mortality and the bacterial density in the hepatopancreas of shrimp decreased. Specifically, the mortality of shrimp in the treatment supplemented with the methanol extract of H. sabdariffa was the lowest, followed by M. pirga and E. globulus. The experimental results also indicated that H. sabdariffa, E. globulus, and M. pirga could improve immune parameters and disease resistance; therefore, they should be employed in sustainable shrimp, practical farming
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