8,063 research outputs found

    Recommendations for nomenclature of ionselective electrodes (IUPAC Recommendations 1994)

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    The rapid growth of interest in the field of ion-selective electrodes (ISEs), within the larger field of electrochemical sensors based on potentiometric, amperometric, and conductometric principles, makes it highly desirable to achieve improved standardization of nomenclature in this area. The previous document, WAC Recommendations 1975 (1) has been corrected using recent experimental and theoretical findings. This report does not define or recommend activity standards or calibration procedures using activity standard

    Texas 4-H Members’ Sense of Community Engagement and Attachment

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    Previous researchers found that youth in 4-H were four times more likely to actively contribute to their communities, two times more likely to be civically active, and five times more likely to graduate from college than non-4- H members. In addition, youth who were more actively involved in community engagement tended to perform at an increased academic achievement level and were more likely to go to college, according to previous studies. The results of the research reported here described participants’ community service and engagement activities both in and outside of 4-H and their attachment to their home communities. Respondents were mostly residents of rural areas, farms, or small towns and cities. They were satisfied with where they lived, and they reported that contributing to their community was important to them and believed it made a positive influence on their life. Most participants also indicated that the community in which they lived and the people closest to them were important parts of their lives and contributed positively to their development. By determining current 4-H members’ level of community attachment, Extension professionals can better understand the influence a community and its stakeholders have in a young person’s leadership development and aspirations

    First Detection of HCO+^+ Absorption in the Magellanic System

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    We present the first detection of HCO+^+ absorption in the Magellanic System. Using the Australia Telescope Compact Array (ATCA), we observed 9 extragalactic radio continuum sources behind the Magellanic System and detected HCO+^+ absorption towards one source located behind the leading edge of the Magellanic Bridge. The detection is located at LSR velocity of v=214.0±0.4 km s−1v=214.0 \pm 0.4\rm\,km\,s^{-1}, with a full width at half maximum of Δv=4.5±1.0 km s−1\Delta v=4.5\pm 1.0\rm\,km\,s^{-1} and optical depth of τ(HCO+)=0.10±0.02\tau(\rm HCO^+)=0.10\pm 0.02. Although there is abundant neutral hydrogen (HI) surrounding the sightline in position-velocity space, at the exact location of the absorber the HI column density is low, <1020 cm−2<10^{20}\rm\,cm^{-2}, and there is little evidence for dust or CO emission from Planck observations. While the origin and survival of molecules in such a diffuse environment remains unclear, dynamical events such as HI flows and cloud collisions in this interacting system likely play an important role.Comment: Accepted for publication in ApJ. 6 pages, 2 figures, 2 table

    En-route to the fission-fusion reaction mechanism: a status update on laser-driven heavy ion acceleration

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    The fission-fusion reaction mechanism was proposed in order to generate extremely neutron-rich nuclei close to the waiting point N = 126 of the rapid neutron capture nucleosynthesis process (r-process). The production of such isotopes and the measurement of their nuclear properties would fundamentally help to increase the understanding of the nucleosynthesis of the heaviest elements in the universe. Major prerequisite for the realization of this new reaction scheme is the development of laser-based acceleration of ultra-dense heavy ion bunches in the mass range of A = 200 and above. In this paper, we review the status of laser-driven heavy ion acceleration in the light of the fission-fusion reaction mechanism. We present results from our latest experiment on heavy ion acceleration, including a new milestone with laser-accelerated heavy ion energies exceeding 5 MeV/u

    Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment

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    The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu Photonics K.K. (HPK) is used in various experiments in particle and astroparticle physics. We describe the test and calibration of 474 PMTs for the reactor antineutrino experiment Double Chooz. The unique test setup at Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate 30 PMTs simultaneously and to characterize the single photo electron response, transit time spread, linear behaviour and saturation effects, photon detection efficiency and high voltage calibration

    Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment

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    The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu Photonics K.K. (HPK) is used in various experiments in particle and astroparticle physics. We describe the test and calibration of 474 PMTs for the reactor antineutrino experiment Double Chooz. The unique test setup at Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate 30 PMTs simultaneously and to characterize the single photo electron response, transit time spread, linear behaviour and saturation effects, photon detection efficiency and high voltage calibration

    Qualification Tests of 474 Photomultiplier Tubes for the Inner Detector of the Double Chooz Experiment

    Full text link
    The hemispherical 10" photomultiplier tube (PMT) R7081 from Hamamatsu Photonics K.K. (HPK) is used in various experiments in particle and astroparticle physics. We describe the test and calibration of 474 PMTs for the reactor antineutrino experiment Double Chooz. The unique test setup at Max-Planck-Institut f\"ur Kernphysik Heidelberg (MPIK) allows one to calibrate 30 PMTs simultaneously and to characterize the single photo electron response, transit time spread, linear behaviour and saturation effects, photon detection efficiency and high voltage calibration

    Remarks on the Upper Bounds on the Higgs Boson Mass from Triviality

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    We study the effects of the one-loop matching conditions on Higgs boson and top quark masses on the triviality bounds on the Higgs boson mass using βλ\beta_{\lambda} with corrected two-loop coefficients. We obtain quite higher results than previous ones and observe that the triviality bounds are not nearly influenced by varying top quark mass over the range measured at CDF and D0. The effects of typo errors in βλ(2)\beta_{\lambda}^{(2)} and the one-loop matching condition on the top quark mass are negligible. We estimate the size of effects on the triviality bounds from the one-loop matching condition on the Higgs boson mass.Comment: 9 pages, tar'ed gzip'ed uuencoded files, LaTex, 5 PostScript figures. To appear in Physical Review
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