1,261 research outputs found

    The structure of the shower disk observed at Mt. Norikura

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    The structure of the EAS shower disk, the arrival time distribution of charged particles at the core of the small or middle size shower, is measured at Mt. Norikura in Japan. Four fast scintillation counters with an area of 0.25 sq m and a fast trigger system are added to the Mt. Norikura EAS array for the study

    Fast scintillation counter system and performance

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    An experimental study of the fast scintillation counter (FS) system to observe a shower disk structure at Mt. Norikura is described, especially the system performance and a pulse wave-form by a single charge particles. The photomultiplier tube (PT) pulse appears at the leading edge of the main pulse. To remove this PT-pulse from the main pulse, the frame of the scintillator vessel was changed. The fast triggering system was made to decrease the dead time which came from the use of the function of the self triggering of the storage oscilloscope (OSC). To provide a new field on the multi-parameter study of the cosmic ray showers, the system response of the FS system also improved as a result of many considerations

    Arsenic toxicity in Hawaii: a case report and review.

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    As mentioned at the beginning of this article, many questions were raised in our one particular case including the problem of verifying true arsenic toxicity and in determining the source of the exposure. In our case, there was a markedly elevated concentration of arsenic in samples of pubic hair and in the sample of urine. While arsenic toxicity can present with GI symptoms, we felt that in this particular case the association of the abdominal pain with arsenic toxicity was unlikely. For one, the patient's symptoms persisted despite apparent adequate treatment for arsenic toxicity. Also, the usual symptom of chronic arsenic toxicity is peripheral neuropathy (which was not documented in our case) and not abdominal pain. After the exhaustive diagnostic workup, we felt that this patient had irritable bowel syndrome and that the discovery of arsenic toxicity was serendipitous. In regards to the etiology of the toxicity, the patient's occupation involved working in the construction industry for a number of years. He indicated a definite exposure to termite-treated wood throughout that period. Wood for building houses, etc. is commonly pressure-treated with an arsenic-based compound; therefore, this source of occupational exposure appears to be a likely one. Another remotely possible source was the ingestion of contaminated illicit drugs. Cases of the use of illicit drugs laced with various toxic agents such as cyanide and strychnine have been reported. Although our patient required analgesics not commensurate with his symptoms, he categorically denied any use of "street" drugs. The random urine drug screen for such was negative.(ABSTRACT TRUNCATED AT 250 WORDS

    Relationship between tonic inhibitory currents and phasic inhibitory activity in the spinal cord lamina II region of adult mice

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    Phasic and tonic inhibitions are two types of inhibitory activities involved in inhibitory processing in the CNS. In the spinal cord dorsal horn, phasic inhibition is mediated by both GABAergic and glycinergic inhibitory postsynaptic currents. In contrast to phasic inhibitory currents, using patch-clamp recording technique on spinal cord slices prepared from adult mice we revealed that tonic inhibitory currents were mediated by GABA(A )receptors but not by glycine receptors in dorsal horn lamina II region. We found that there was a linear relationship (r = 0.85) between the amplitude of tonic inhibitory currents and the frequency of GABAergic inhibitory postsynaptic currents. Analysis of charge transfer showed that the charges carried by tonic inhibitory currents were about 6 times of charges carried by phasic inhibitory currents. The prominent charge transfer by tonic inhibitory currents and their synaptic activity dependency suggest a significant role of tonic inhibition in sensory processing

    Comparison of absolute intensity between EAS with gamma-families and general EAS at Mount Norikura

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    Gamma-families with total energy greater than 10 TeV, found in the EX chamber which was cooperated with the EAS array were combined with EAS triggered by big bursts. The absolute intensity of the size spectrum of these combined EAS was compared with that of general EAS obtained by AS trigger. The EAS with sizes greater than 2x1 million were always accompanied by gamma-families with sigma E sub gamma H 10 TeV, n sub gamma, H 2 and Emin=3 TeV, although the rate of EAS accompaning such gamma-families decreases rapidly as their sizes decrease

    Search for non-random feature in arrival times of air showers

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    We have searched for non-random components in arrival times of air showers of mean energy of 1 PeV. By counting the number of air showers observed within time windows of 20-60 minutes, we find small deviation of air shower data from the conventional view of uniformly random cosmic ray injection. The arrival directions of the non-random events concentrate at the direction of the Galactic plane. Though the significance of these events is not so high because of the lack of statistics, they may be induced by sporadic non-random injection of ultra-high energy γ-rays from the Galactic plane

    Tension-tension testing of a novel mooring rope construction

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    This is the author accepted manuscript.Synthetic fibre ropes are in widespread use in maritime applications ranging from lifting to temporary and permanent mooring systems for vessels, offshore equipment and platforms. The selection of synthetic ropes over conventional steel components is motivated by several key advantages including selectable axial stiffness, energy absorption (and hence load mitigation), fatigue resistance and low unit cost. The long-term use of ropes as safety critical components in potentially high dynamic loading environments necessitates that new designs are verified using stringent qualification procedures. The International Organization for Standardization (ISO) is one certification body that has produced several guidelines for the testing of synthetic ropes encompassing quasi-static and dynamic loading as well as fatigue cycling. This paper presents the results of tension-tension tests carried out to ISO 2307:2010, ISO 18692:2007(E) and ISO/TS 19336:2015(E) on three different 12-strand rope constructions manufactured by Ashimori Industry Co. Ltd from polyester and Vectran® fibres. The purpose of the tests was to characterise the performance of a novel 12-strand construction and compare this to a conventional 12-strand construction. Utilising the Dynamic Marine Component test facility (DMaC) at the University of Exeter several key performance metrics were determined including; elongation, minimum break load (MBL) and quasi-static and dynamic stiffness. During the ISO 2307:2010(E) test programme the samples were tested dry and during the ISO 18692:2007(E) and ISO/TS 19336:2015(E) test programmes the samples were fully submerged in tap water after being soaked for at least 24 hours. Two methods were used to quantify sample extension: i) an optical tracking system and ii) a draw-wire potentiometer. Axial compression fatigue and cyclic loading endurance tests were also carried out on two Vectran® samples. Further load-to-failure tests and sample analysis were also carried out by Ashimori Industry Co. Ltd. It was found that the MBL of the samples exceeded the values specified by the manufacturer (by 7.7-29.5% for the polyester samples) with failure occurring at the splices in all cases and minor abrasion noted in several locations. The measured MBL of the novel polyester Straight Strand Rope (SSR) construction was up to 16% higher than the conventional construction with increases of quasi-static and dynamic stiffness of up to 6.8%. Differences between the viscoelastic and viscoplastic behaviour of the samples were also noted. The data obtained during these tests will provide insight into the behaviour of these materials and different rope constructions which will be of use to rope manufacturers, mooring system designers in addition to offshore equipment and vessel operators.The authors at the University of Exeter would like to thank their colleagues at Nagasaki University and Ashimori Industry Co. Ltd for being given the opportunity to carry out the interesting work reported in this paper. Through the Peninsula Research Institute for Marine Renewable Energy (PRIMaRE) consortium, the DMaC test facility was funded from the ERDF Convergence programme and South West Regional Development Agenc

    Fabrication of ZnSnP(2) thin films by phosphidation

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    ZnSnP(2) is a promising candidate as a solar absorbing material consisting of earth-abundant and low-toxic elements. In this study, the phosphidation method, where co-sputtered Zn–Sn thin films react with phosphorus gas, was adopted for fabricating ZnSnP(2) thin films. To establish the conditions for producing ZnSnP(2) thin films, we investigated the influence of phosphidation temperature on the product phases, and interpreted the experimental results using chemical potential diagrams of the Zn–Sn–P system. ZnSnP(2) thin films with a single phase were obtained by phosphidation at 500 °C under a phosphorus vapor pressure of 10[−2] atm. However, formation of ZnSnP(2)protrusions was observed on the surface of the thin films. Based on the experimental results and the chemical potential diagrams, it is indicated that un-reacted liquid Sn particles reacted with Zn and phosphorus gas to form ZnSnP(2) protrusions in a manner similar to the vapor-Liquid-Solid growth mode
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