593 research outputs found

    Identification of potential locations for small hydropower plant based on resources time footprint: A case study in Dan River Basin, China

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    mall hydropower has attracted extensive interest as a clean technology. This study first identified possible sites of small hydropower plants with estimated capacity, and then utilized resources time footprint as a novel way to evaluate the impact of small hydropower plants on the aspects of materials, CO2, labor, and land. Resources time footprint is a sustainability indicator that uses a uniform time unit (years). It assesses whether the usage of resources exceeds the amount allocated to different people and generations. The smaller the value of resources time footprint, the more environmentally friendly is the process. Preferential locations for small hydropower in Dan River were specified, with a potential capacity ranging from 273 to 1175 kW. Resources time footprint of copper is 8.9–47.3 times as large as that of steel. Resources time footprint of CO2 emissions is much smaller than that of other aspects, revealing that small hydropower has a great potential to mitigate the greenhouse effect. The overall resources time footprint decreases with an increase in the installed capacity. The methodology proposed in this study can be used to identify the ideal locations for setting up small hydropower plants in other regions as well. © 2023 The AuthorsThis work was funded by the ESPEC Foundation for Global Environment Research and Technology (Charitable Trust) (ESPEC Prize for the Encouragement of Environmental Studies). This work was also conducted under the joint research program of the Institute of Materials and Systems for Sustainability (IMaSS), Nagoya University. This work was financially supported by the JST SPRING (grant number JPMJSP2125 ). X.H. would like to take this opportunity to thank the “Interdisciplinary Frontier Next-Generation Researcher Program of the Tokai Higher Education and Research System.” The author X.H. would like to thank the inspiring discussion with Dr. Nobuko Kawaguchi and Bifu Huang. We thank Linwei Tao for data validatio

    Isogeometric Analysis for Vehicle Model in Dynamic Explicit Method

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    In Isogeometric Analysis, CAD format models can be used for analysis by using BSpline/NURBS, which is used for drawing shapes in CAD, as a shape function of the finite element method. This method can significantly reduce the time required to generate a mesh, which used to take much time. It is necessary to verify the performance of Isogeometric Analysis in the dynamic explicit method for application to automobile analysis. In this study, automobile structural parts were modeled by Isogeometric Analysis method and structural analysis was performed by the dynamic explicit method for evaluation

    The induction levels of heat shock protein 70 differentiate the vulnerabilities to mutant huntingtin among neuronal subtypes

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    The reason why vulnerabilities to mutant polyglutamine (polyQ) proteins are different among neuronal subtypes is mostly unknown. In this study, we compared the gene expression profiles of three types of primary neurons expressing huntingtin (htt) or ataxin-1. We found that heat shock protein 70 (hsp70), a well known chaperone molecule protecting neurons in the polyQ pathology, was dramatically upregulated only by mutant htt and selectively in the granule cells of the cerebellum. Granule cells, which are insensitive to degeneration in the human Huntington's disease (HD) pathology, lost their resistance by suppressing hsp70 with siRNA, whereas cortical neurons, affected in human HD, gained resistance by overexpressing hsp70. This indicates that induction levels of hsp70 are a critical factor for determining vulnerabilities to mutant htt among neuronal subtypes. CAT (chloramphenicol acetyltransferase) assays showed that CBF (CCAAT box binding factor, CCAAT/enhancer binding protein zeta) activated, but p53 repressed transcription of the hsp70 gene in granule cells. Basal and mutant htt-induced expression levels of p53 were remarkably lower in granule cells than in cortical neurons, suggesting that different magnitudes of p53 are linked to distinct induction levels of hsp70. Surprisingly, however, heat shock factor 1 was not activated in granule cells by mutant htt. Collectively, different levels of hsp70 among neuronal subtypes might be involved in selective neuronal death in the HD pathology

    Study of Non-Standard Neutrino Interactions with Atmospheric Neutrino Data in Super-Kamiokande I and II

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    In this paper we study non-standard neutrino interactions as an example of physics beyond the standard model using atmospheric neutrino data collected during the Super-Kamiokande I(1996-2001) and II(2003-2005) periods. We focus on flavor-changing-neutral-currents (FCNC), which allow neutrino flavor transitions via neutral current interactions, and effects which violate lepton non-universality (NU) and give rise to different neutral-current interaction-amplitudes for different neutrino flavors. We obtain a limit on the FCNC coupling parameter, varepsilon_{mu tau}, |varepsilon_{mu tau}|<1.1 x 10^{-2} at 90%C.L. and various constraints on other FCNC parameters as a function of the NU coupling, varepsilon_{e e}. We find no evidence of non-standard neutrino interactions in the Super-Kamiokande atmospheric data.Comment: 12 Pages, 14 figures. To be submitted to Phys. Rev.

    Magnetic Interactions and Transport in (Ga,Cr)As

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    The magnetic, transport, and structural properties of (Ga,Cr)As are reported. Zincblende Ga1x_{1-x}Crx_{x}As was grown by low-temperature molecular beam epitaxy (MBE). At low concentrations, x\sim0.1, the materials exhibit unusual magnetic properties associated with the random magnetism of the alloy. At low temperatures the magnetization M(B) increases rapidly with increasing field due to the alignment of ferromagnetic units (polarons or clusters) having large dipole moments of order 10-102^2μB\mu_B. A standard model of superparamagnetism is inadequate for describing both the field and temperature dependence of the magnetization M(B,T). In order to explain M(B) at low temperatures we employ a distributed magnetic moment (DMM) model in which polarons or clusters of ions have a distribution of moments. It is also found that the magnetic susceptibility increases for decreasing temperature but saturates below T=4 K. The inverse susceptibility follows a linear-T Curie-Weiss law and extrapolates to a magnetic transition temperature θ\theta=10 K. In magnetotransport measurements, a room temperature resistivity of ρ\rho=0.1 Ω\Omegacm and a hole concentration of 1020\sim10^{20} cm3^{-3} are found, indicating that Cr can also act as a acceptor similar to Mn. The resistivity increases rapidly for decreasing temperature below room temperature, and becomes strongly insulating at low temperatures. The conductivity follows exp[-(T1_1/T)1/2^{1/2}] over a large range of conductivity, possible evidence of tunneling between polarons or clusters.Comment: To appear in PRB 15 Mar 200

    Search for Nucleon Decay into Charged Anti-lepton plus Meson in Super-Kamiokande I and II

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    Searches for a nucleon decay into a charged anti-lepton (e^+ or {\mu}^+) plus a light meson ({\pi}^0, {\pi}^-, {\eta}, {\rho}^0, {\rho}^-, {\omega}) were performed using the Super-Kamiokande I and II data. Twelve nucleon decay modes were searched for. The total exposure is 140.9 kiloton \cdot years, which includes a 91.7 kiloton \cdot year exposure (1489.2 live days) of Super-Kamiokande-I and a 49.2 kiloton \cdot year exposure (798.6 live days) of Super-Kamiokande-II. The number of candidate events in the data was consistent with the atmospheric neutrino background expectation. No significant evidence for a nucleon decay was observed in the data. Thus, lower limits on the nucleon partial lifetime at 90% confidence level were obtained. The limits range from 3.6 \times 10^31 to 8.2 \times 10^33 years, depending on the decay modes.Comment: 25 pages, 18 figure

    An Indirect Search for WIMPs in the Sun using 3109.6 days of upward-going muons in Super-Kamiokande

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    We present the result of an indirect search for high energy neutrinos from WIMP annihilation in the Sun using upward-going muon (upmu) events at Super-Kamiokande. Datasets from SKI-SKIII (3109.6 days) were used for the analysis. We looked for an excess of neutrino signal from the Sun as compared with the expected atmospheric neutrino background in three upmu categories: stopping, non-showering, and showering. No significant excess was observed. The 90% C.L. upper limits of upward-going muon flux induced by WIMPs of 100 GeV/c2^2 were 6.4×1015\times10^{-15} cm2^{-2} sec1^{-1} and 4.0×1015\times10^{-15} cm2^{-2} sec1^{-1} for the soft and hard annihilation channels, respectively. These limits correspond to upper limits of 4.5×1039\times10^{-39} cm2^{-2} and 2.7×1040\times10^{-40} cm2^{-2} for spin-dependent WIMP-nucleon scattering cross sections in the soft and hard annihilation channels, respectively.Comment: Add journal reference. Also fixed typo and cosmetic things in the old draf

    Atmospheric neutrino oscillation analysis with sub-leading effects in Super-Kamiokande I, II, and III

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    We present a search for non-zero theta_{13} and deviations of sin^2 theta_{23} from 0.5 in the oscillations of atmospheric neutrino data from Super-Kamiokande -I, -II, and -III. No distortions of the neutrino flux consistent with non-zero theta_{13} are found and both neutrino mass hierarchy hypotheses are in agreement with the data. The data are best fit at Delta m^2 = 2.1 x 10^-3 eV^2, sin^2 theta_{13} = 0.0, and sin^2 theta_{23} =0.5. In the normal (inverted) hierarchy theta_{13} and Delta m^2 are constrained at the one-dimensional 90% C.L. to sin^2 theta_{13} < 0.04 (0.09) and 1.9 (1.7) x 10^-3 < Delta m^2 < 2.6 (2.7) x 10^-3 eV^2. The atmospheric mixing angle is within 0.407 <= sin^2 theta_{23} <= 0.583 at 90% C.L.Comment: 17 Pages, 14 figures. To be submitted to Phys. Rev. D Minor update to text after referee comments. Figures modified for better grayscale printing
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