18 research outputs found

    High density mapping systems for SRF cavities

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    20th International Conference on RF Superconductivity (SRF 2021)In order to evaluate the performance of a superconducting cavity, we are developing a mapping system to measure the distribution of cavity temperature, field emission X-rays, and trapped magnetic flux with high positional resolution. In order to construct a system with high positional resolution, a large number of sensors are required. However, as the number of sensors increases, so does the amount of wiring, which increases the complexity of the wiring in the cryogenic apparatus, and also increases the heat transfer through the wiring, which disturb efficient operation of cavity tests. We are developing an efficient mapping system with a multiplexer that scans the readout signal on the same circuit as the sensor in the cryogenic dewar where the cavity test is conducted. In this presentation, we report the outline and test results of the mapping system under developmen

    Fundamental physics activities with pulsed neutron at J-PARC(BL05)

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    "Neutron Optics and Physics (NOP/ BL05)" at MLF in J-PARC is a beamline for studies of fundamental physics. The beamline is divided into three branches so that different experiments can be performed in parallel. These beam branches are being used to develop a variety of new projects. We are developing an experimental project to measure the neutron lifetime with total uncertainty of 1 s (0.1%). The neutron lifetime is an important parameter in elementary particle and astrophysics. Thus far, the neutron lifetime has been measured by several groups; however, different values are obtained from different measurement methods. This experiment is using a method with different sources of systematic uncertainty than measurements conducted to date. We are also developing a source of pulsed ultra-cold neutrons (UCNs) produced from a Doppler shifter are available at the unpolarized beam branch. We are developing a time focusing device for UCNs, a so called "rebuncher", which can increase UCN density from a pulsed UCN source. At the low divergence beam branch, an experiment to search an unknown intermediate force with nanometer range is performed by measuring the angular dependence of neutron scattering by noble gases. Finally the beamline is also used for the research and development of optical elements and detectors. For example, a position sensitive neutron detector that uses emulsion to achieve sub-micrometer resolution is currently under development. We have succeeded in detecting cold and ultra-cold neutrons using the emulsion detector.Comment: 9 pages, 5 figures, Proceedings of International Conference on Neutron Optics (NOP2017

    Measurement and finite element analysis of the load-dependent pressure redistribution behavior of various types of mattresses

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    Load dependence must be kept in mind when evaluating mattress pressure redistribution, to prevent the development of pressure ulcers at bony prominences. However, there is no standardized method for analyzing load-dependent behavior after mattress pressure redistribution. In this study, a portable palmtop device with a simple load-sensing mechanism was developed for measuring the mean pressure exerted by a protruding shaft surrounded by a disc on low-resilience polyurethane (LRPu) foam, latex foam, coconut fiber and latex (CFL) mattresses, as well as polyurethane (Pu) foam bed and an LRPu foam mattress laid on a bed. Finite element (FE) analysis was used to analyze deformation and contact pressure in detail. The pressure redistribution was greatest for the LRPu foam mattress, and excessive compression was avoided by using an underlay made of stiff Pu foam. FE analysis revealed that the contact pressure increased significantly near the outer circumference of the protruding shaft and the surrounding disc. Significant nonuniformity in pressure was evident, according to the edge and bottom geometry of the device. The measurements and FE analysis revealed load-dependent pressure redistribution behavior, which should allow mattresses to be tailored on an individual basis

    Decision-making in electrical appliance use in the home

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    This paper presents the results of a survey as well as an argument from the viewpoint of behavioral economics with the aim of clarifying how consumers make decisions about electrical appliance use in the home. A survey of consumers showed that most have little awareness of the energy efficiency of appliances, the price of the services produced by electrical appliances, or electricity rates. These findings indicate that price does not function as a signal in electricity consumption through electrical appliance use. Rather, we found that consumer decision-making in electricity consumption is dependent on the characteristics of the particular electrical appliances they use. Additionally, we argue that the payment system for home electricity consumption plays an important role in decision-making, causing biases due to aspects of human psychology discussed here in terms of satisficing and heuristics, payment decoupling, and budgeting. We conclude that decision-making about electrical appliance use and electricity consumption in the home is not always rational and is affected both by the particular characteristics of appliances and the payment system for electricity consumption along with human psychology.

    Complete Stereochemical Assignment of Campechic Acids A and B

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    Campechic acids A and B are anti-invasive polyketide antibiotics isolated from Streptomyces sp. CHI93 strain. Herein we describe stereoselective synthesis of the C-16–C-30 fragment of campechic acids A and B via a biosynthesis-inspired epoxide-opening cascade and its NMR spectroscopic comparison with the authentic degradation product, resulting in configurational assignment of the C-21, C-24, C-25, and C-28 stereogenic centers and reassignment of the C-18 stereogenic center
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