185 research outputs found

    Vertical-Vibration Suppressing Design of Accumulator with New Vibration-Measuring Method

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    A compressor was developed using R32 which was a low GWP R32 refrigerant for coping with global warming. However, there is a tendency for vibrations of a compressor to also increase because the circulation of refrigerant increases according to specification for using R32 refrigerant. Since large vibrations of a compressor causes outdoor units to generate solid propagation sound, there is a need for a technology that can reduce vibration of a compressor. However, a vibration-measuring method to analyze such vibration had not been fully developed and it was difficult to specify the cause. Accordingly, a new vibration-measuring method was developed specifically for compressors. The use of this measuring method allowed to discover that one of the unresolved problems with sound of outdoor units was the vertical vibration of the accumulator housed in the compressor. Moreover, it was found that the accumulator vibrates vertically due to the acoustic resonance inside the casing, which led to develop a new (accumulator) design with a focus on resonance. There is a type of spatial resonance inside an accumulator that has a phase difference with the antinode of sound pressure appearing at the upper and lower ends of the space. The vertical force caused by the difference in the sound pressure becomes excitation force, which then causes vertical vibration of the accumulator. Therefore, preventing this resonance from occurring can help suppress the vertical vibration. In order to prevent the generation of resonance, a plate-shaped reflection member was placed inside the accumulator, and it proved to be effective in suppressing the vertical vibration

    Simulation of Stretching Deformation of Film for Electronic Devices in Automotive Applications

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    In this study, we proposed a simulation method for film transverse stretching based on the finite element method using the orthogonal anisotropy plastic model. The simulation method can analyse the large deformation of film stretching and predict whether the kink band phenomenon occurs during the film transverse stretching. The validity of the simulation method was confirmed by the transverse stretching tests performed on the fluorine films with different longitudinal stretching ratios. Using the simulation method, we clarified that the plastic anisotropy index of the longitudinally stretched fluorine film has a great influence on the presence or absence of the kink band phenomenon during the film transverse stretching. The plastic anisotropy index of the longitudinally stretched fluorine film can be related to its birefringence, and the two are approximately in a linear relationship. Moreover, we revealed the change in film stretching deformation due to difference in the ratio of the stretching zone length to the width of the tenter

    Preliminary Design Study of the TMT Telescope Structure System: Overview

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    We present an overview of the preliminary design of the Telescope Structure System (STR) of Thirty Meter Telescope (TMT). NAOJ was given responsibility for the TMT STR in early 2012 and engaged Mitsubishi Electric Corporation (MELCO) to take over the preliminary design work. MELCO performed a comprehensive preliminary design study in 2012 and 2013 and the design successfully passed its Preliminary Design Review (PDR) in November 2013 and April 2014. Design optimizations were pursued to better meet the design requirements and improvements were made in the designs of many of the telescope subsystems as follows: 1. 6-legged Top End configuration to support secondary mirror (M2) in order to reduce deformation of the Top End and to keep the same 4% blockage of the full aperture as the previous STR design. 2. “Double Lower Tube” of the elevation (EL) structure to reduce the required stroke of the primary mirror (M1) actuators to compensate the primary mirror cell (M1 Cell) deformation caused during the EL angle change in accordance with the requirements. 3. M1 Segment Handling System (SHS) to be able to make removing and installing 10 Mirror Segment Assemblies per day safely and with ease over M1 area where access of personnel is extremely difficult. This requires semi-automatic sequence operation and a robotic Segment Lifting Fixture (SLF) designed based on the Compliance Control System, developed for controlling industrial robots, with a mechanism to enable precise control within the six degrees of freedom of position control. 4. CO2 snow cleaning system to clean M1 every few weeks that is similar to the mechanical system that has been used at Subaru Telescope. 5. Seismic isolation and restraint systems with respect to safety; the maximum acceleration allowed for M1, M2, tertiary mirror (M3), LGSF, and science instruments in 1,000 year return period earthquakes are defined in the requirements. The Seismic requirements apply to any EL angle, regardless of the operational status of Hydro Static Bearing (HSB) system and stow lock pins. In order to find a practical solution, design optimization study for seismic risk mitigation was carried out extensively, including the performing of dynamic response analyses of the STR system under the time dependent acceleration profile of seven major earthquakes. The work is now moving to the final design phase from April 2014 for two years

    Tissue Intrinsic Fluorescence Spectra-Based Digital Pathology of Liver Fibrosis by Marker-Controlled Segmentation

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    Tissue intrinsic emission fluorescence provides useful diagnostic information for various diseases. Because of its unique feature of spectral profiles depending on tissue types, spectroscopic imaging is a promising tool for accurate evaluation of endogenous fluorophores. However, due to difficulties in discriminating those sources, quantitative analysis remains challenging. In this study, we quantitatively investigated spectral-spatial features of multi-photon excitation fluorescence in normal and diseased livers. For morphometrics of multi-photon excitation spectra, we examined a marker-controlled segmentation approach and its application to liver fibrosis assessment by employing a mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis. We formulated a procedure of internal marker selection where markers were chosen to reflect typical biochemical species in the liver, followed by image segmentation and local morphological feature extraction. Image segmentation enabled us to apply mathematical morphology analysis, and the local feature was applied to the automated classification test based on a machine learning framework, both demonstrating highly accurate classifications. Through the analyses, we showed that spectral imaging of native fluorescence from liver tissues have the capability of differentiating not only between normal and diseased, but also between progressive disease states. The proposed approach provides the basics of spectroscopy-based digital histopathology of chronic liver diseases, and can be applied to a range of diseases associated with autofluorescence alterations

    Tracing amino acid exchange during host-pathogen interaction by combined stable-isotope time-resolved Raman spectral imaging

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    This study investigates the temporal and spatial interchange of the aromatic amino acid phenylalanine (Phe) between human retinal pigment epithelial cell line (ARPE-19) and tachyzoites of the apicomplexan protozoan parasite Toxoplasma gondii (T. gondii). Stable isotope labelling by amino acids in cell culture (SILAC) is combined with Raman micro-spectroscopy to selectively monitor the incorporation of deuterium-labelled Phe into proteins in individual live tachyzoites. Our results show a very rapid uptake of L-Phe(D8) by the intracellular growing parasite. T. gondii tachyzoites are capable of extracting L-Phe(D8) from host cells as soon as it invades the cell. L-Phe(D8) from the host cell completely replaces the L-Phe within T. gondii tachyzoites 7–9 hours after infection. A quantitative model based on Raman spectra allowed an estimation of the exchange rate of Phe as 0.5–1.6 × 104 molecules/s. On the other hand, extracellular tachyzoites were not able to consume L-Phe(D8) after 24 hours of infection. These findings further our understanding of the amino acid trafficking between host cells and this strictly intracellular parasite. In particular, this study highlights new aspects of the metabolism of amino acid Phe operative during the interaction between T. gondii and its host cell
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