275 research outputs found

    The Position and Function of Macroscopic Analysis in the Failure Analysis of Railway Fasteners

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    Macroscopic analysis plays an important role in failure analysis, which cannot be replaced by other analyzing methods. In recent years, with the development of characterization techniques, more and more engineers and technicians rely on the advanced analytical testing methods in the process of failure analysis, ignoring the methods and means of macroscopic analysis. This can easily lead to some wrong judgments. Therefore, this chapter will combine with the cases to explain the position and role of macroanalysis in the failure analysis of rail fastening clips and to offer references for engineers and technicians in relevant fields

    Modeling of System Energy of Rock Under Harmonic Vibro-Impact

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    Hamiltonian function is proposed and the modeling of system energy of rock under harmonic vibro-impact is undertaken in this study. The modeling includes two aspects, namely, energy equation of rock system with no damping and the one with damping. Also, the results of numerical simulation are presented. Four main control parameters are considered, including natural frequency of rock, impact frequency, impact force, damping coefficient.It is confirmed that the system energy of rock will increase with the increase of natural frequency impact frequency and impact force. While impact force, damping coefficient and stiffness of rock will mainly decide the vibration amplitude of system energy

    Vektor Malaria Baru di Kabupaten Kotabaru, Provinsi Kalimantan Selatan, Indonesia

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    Nyamuk Anopheles merupakan vektor dari Malaria. Dari sekitar 400 spesies nyamuk Anopheles telah ditemukan 67 spesies dapat menularkan malaria dan 24 diantaranya ditemukan di Indonesia. Kabupaten Kotabaru merupakan kabupaten endemis malaria di Kalimantan Selatan. Data mengenai spesies vektor malaria spesifik pada suatu daerah sangat berperan penting sebagai salah satu bahan rekomendasi bagi tindak lanjut kebijakan pengendalian malaria. Penelitian bertujuan untuk mengetahui data vektor malaria di Kabupaten Kotabaru melalui uji PCR. Penelitian deskriptif dengan desain cross sectional. Penangkapan nyamuk dilakukan di Desa Siayuh Trans dan Magalau Hulu, tambang emas Kura-Kura dan Desa Muara Uri dengan metode penangkapan UOL, UOD, dinding dan kandang. Uji PCR dilaksanakan di laboratorium biomolekuler BBPPVRP Salatiga pada bulan Februari-April 2015. Hasil penangkapan nyamuk didapatkan 345 ekor nyamuk Anopheles yang terdiri dari 9 spesies: An. barbirostris, An. tesselatus, An. balabacensis, An. vagus, An. hyrcanus group, An. peditaeniatus, An. kochi, An. flavirostris, An. umbrosus. Seluruh nyamuk Anopheles yang didapatkan dibuat 56 pool sampel Anopheles sp untuk diuji PCR yang telah diklasifikasikan berdasarkan spesies, tanggal dan metode penangkapan. Hasil PCR terindentifikasi 3 spesies vektor malaria di Desa Siayuh Trans yaitu An. vagus, An. peditaeniatus dan An. tesselatus yang merupakan vektor malaria baru di Propinsi Kalimantan Selatan

    Low-mass dark matter search results from full exposure of PandaX-I experiment

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    We report the results of a weakly-interacting massive particle (WIMP) dark matter search using the full 80.1\;live-day exposure of the first stage of the PandaX experiment (PandaX-I) located in the China Jin-Ping Underground Laboratory. The PandaX-I detector has been optimized for detecting low-mass WIMPs, achieving a photon detection efficiency of 9.6\%. With a fiducial liquid xenon target mass of 54.0\,kg, no significant excess event were found above the expected background. A profile likelihood analysis confirms our earlier finding that the PandaX-I data disfavor all positive low-mass WIMP signals reported in the literature under standard assumptions. A stringent bound on the low mass WIMP is set at WIMP mass below 10\,GeV/c2^2, demonstrating that liquid xenon detectors can be competitive for low-mass WIMP searches.Comment: v3 as accepted by PRD. Minor update in the text in response to referee comments. Separating Fig. 11(a) and (b) into Fig. 11 and Fig. 12. Legend tweak in Fig. 9(b) and 9(c) as suggested by referee, as well as a missing legend for CRESST-II legend in Fig. 12 (now Fig. 13). Same version as submitted to PR
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