706 research outputs found

    VEGETATION BEHAVIOR AND ITS HABITAT REGION AGAINST FLOOD FLOW IN URBAN STREAMS

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    Hydraulic effects on the vegetation behavior and on its habitat region against flood flow in the urban streams were analysed in this paper. Vegetation behavior was classified into stable, recovered, damaged and swept away stages. Criteria between recovered and damaged status were determined by the bending angle of the aquatic plants. Aquatic plants whose bending angle is lower than 30~50 degree is recovered, but they were damaged and cannot be recovered when the bending angle is higher than 30~50 degree. Phragmites japonica was inhabited in the hydraulic condition of high Froude number which shows that it was inhabited in the upstream reaches. Phragmites communis was inhabited in the relatively low Froude number compared with Phragmites japonica. This shows that it was inhabited in the downstream reaches. Persicaria blumei was found in the relatively wide range of flow velocity and flow depth, which shows that it was inhabited in the middle and downstream reaches. Criterion on the vegetation behavior of Persicaria thunbergii was not clear, which implies that it may be affected by the flow turbulence rather than flow velocity and flow depth

    NUMERICAL ANALYSIS OF THERMAL STRATIFICATION IN THE UPPER PLENUM OF THE MONJU FAST REACTOR

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    A numerical analysis of thermal stratification in the upper plenum of the MONJU fast breeder reactor was performed. Calculations were performed for a 1/6 simplified model of the MONJU reactor using the commercial code, CFX-13. To better resolve the geometrically complex upper core structure of the MONJU reactor, the porous media approach was adopted for the simulation. First, a steady state solution was obtained and the transient solutions were then obtained for the turbine trip test conducted in December 1995. The time dependent inlet conditions for the mass flow rate and temperature were provided by JAEA. Good agreement with the experimental data was observed for steady state solution. The numerical solution of the transient analysis shows the formation of thermal stratification within the upper plenum of the reactor vessel during the turbine trip test. The temporal variations of temperature were predicted accurately by the present method in the initial rapid coastdown period (∼300 seconds). However, transient numerical solutions show a faster thermal mixing than that observed in the experiment after the initial coastdown period. A nearly homogenization of the temperature field in the upper plenum is predicted after about 900 seconds, which is a much shorter-term thermal stratification than the experimental data indicates. This discrepancy may be due to the shortcoming of the turbulence models available in the CFX-13 code for a natural convection flow with thermal stratification

    Light cold dark matter from non-thermal decay

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    We investigate the mass range and the corresponding free-streaming length scale of dark matter produced non-thermally from decay of heavy objects which can be either dominant or sub-dominant at the moment of decay. We show that the resulting dark matter could be very light well below keV scale with a free-streaming length satisfying the Lyman-{\alpha} constraints. We demonstrate two explicit examples for such light cold dark matter.Comment: 8 pages, 4 figure

    Designing a Data Warehouse for Cyber Crimes

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    One of the greatest challenges facing modern society is the rising tide of cyber crimes. These crimes, since they rarely fit the model of conventional crimes, are difficult to investigate, hard to analyze, and difficult to prosecute. Collecting data in a unified framework is a mandatory step that will assist the investigator in sorting through the mountains of data. In this paper, we explore designing a dimensional model for a data warehouse that can be used in analyzing cyber crime data. We also present some interesting queries and the types of cyber crime analyses that can be performed based on the data warehouse. We discuss several ways of utilizing the data warehouse using OLAP and data mining technologies. We finally discuss legal issues and data population issues for the data warehouse

    Test of the reaction mechanism for gamma N -> K Lambda(1520) using the polarized photon

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    We study the reaction mechanism for the photoproduction of the Lambda(1520), based on an effective Lagrangian approach. We investigate each contribution of the s-, u-, t-channel processes and contact term, separately. One of the most characteristic features of this reaction is the contact-term dominance which governs the photoproduction from the proton, when the K*-exchange contribution is possibly not too large. We suggest several different ways of the polarizations and arrangement of the beam and target to make to understand the role of each contribution separately in future experiments.Comment: 10 pages, 14 figures, accepted for publication in PR

    Designing a Data Warehouse for Cyber Crimes

    Get PDF
    One of the greatest challenges facing modern society is the rising tide of cyber crimes. These crimes, since they rarely fit the model of conventional crimes, are difficult to investigate, hard to analyze, and difficult to prosecute. Collecting data in a unified framework is a mandatory step that will assist the investigator in sorting through the mountains of data. In this paper, we explore designing a dimensional model for a data warehouse that can be used in analyzing cyber crime data. We also present some interesting queries and the types of cyber crime analyses that can be performed based on the data warehouse. We discuss several ways of utilizing the data warehouse using OLAP and data mining technologies. We finally discuss legal issues and data population issues for the data warehouse

    Cross-genotype protection of live-attenuated vaccine candidate for severe fever with thrombocytopenia syndrome virus in a ferret model

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    Severe fever with thrombocytopenia syndrome (SFTS) virus (SFTSV) is an emerging tick-borne virus classified within the Banyangvirus genus. SFTS disease has been reported throughout East Asia since 2009 and is characterized by high fever, thrombocytopenia, and leukopenia and has a 12 to 30% case fatality rate. Due to the recent emergence of SFTSV, there has been little time to conduct research into preventative measures aimed at combatting the virus. SFTSV is listed as one of the World Health Organization’s Prioritized Pathogens for research into antiviral therapeutics and vaccine development. Here, we report 2 attenuated recombinant SFTS viruses that induce a humoral immune response in immunized ferrets and confer complete cross-genotype protection to lethal challenge. Animals infected with rHB29NSsP102A or rHB2912aaNSs (both genotype D) had a reduced viral load in both serum and tissues and presented without high fever, thrombocytopenia, or mortality associated with infection. rHB29NSsP102A- or rHB2912aaNSs-immunized animals developed a robust anti-SFTSV immune response against cross-genotype isolates of SFTSV. This immune response was capable of neutralizing live virus in a focus-reduction neutralization test (FRNT) and was 100% protective against a cross-genotype lethal challenge with the CB1/2014 strain of SFTSV (genotype B). Thus, using our midsized, aged ferret infection model, we demonstrate 2 live attenuated vaccine candidates against the emerging pathogen SFTSV
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