413 research outputs found

    Characterized Hysteresis Model and a Magnetic Pulse Compression Circuit

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    Mathematical model of hysteresis is introduced, and it is characterized to analyze highly saturable magnetic equipment on the effect of specific paramenters. Using this mathematical model, performance of magnetic pulse compression circuit is nemerically analyzed

    The Diagnosis and Treatment of Early-Stage Colorectal Cancer

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    The introduction of colorectal endoscopic submucosal dissection (ESD) has expanded the applications for endoscopic treatment; as a result, lesions with low metastatic potential can be treated endoscopically regardless of the lesion size. The most attractive feature of ESD is the achievement of en bloc resection with a lower local recurrence rate in comparison to that of endoscopic piecemeal mucosal resection. However, in case of gastric cancers, ESD is not as widely applied to the treatment of colorectal neoplasms because of its technical difficulty, longer procedural time, and increased perforation risk. In the movement toward diversified endoscopic treatment strategies for superficial colorectal neoplasms, endoscopists who begin to perform ESD need to recognize the indications of ESD, as well as the technical issues and associated complications of this procedure

    Oldest record of Trimeniaceae from the Early Cretaceous of northern Japan

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    <p>Abstract</p> <p>Background</p> <p>Molecular phylogenetic analyses have identified Trimeniaceae, a monotypic family distributed only in Oceania, as among the earliest diverging families of extant angiosperms. Therefore, the fossils of this family are helpful to understand the earliest flowering plants. Paleobotanical information is also important to track the historical and geographical pathways to endemism of the Trimeniaceae. However, fossils of the family were previously unknown from the Early Cretaceous, the time when the angiosperm radiated. In this study, we report a seed from the late Albian (ca. 100 million years ago) of Japan representing the oldest known occurrence of Trimeniaceae and discuss the character evolution and biogeography of this family.</p> <p>Results</p> <p>A structurally preserved seed was collected from the early Late Albian Hikagenosawa Formation of the Yezo Group, which was deposited in palaeolatitudes of 35 to 40°N. The seed has a multilayered stony exotesta with alveolate surface, parenchymatous mesotesta, and operculate inner integument, which are characteristic to extant trimeniaceous seeds. However, the seed differs from extant seeds, i.e., in its well-developed endosperm and absence of antiraphal vascular bundle. Thus, the seed would be a new genus and species of Trimeniaceae.</p> <p>Conclusion</p> <p>The fossil seed indicates that seed coat characters were conserved for 100 million years or more in Trimeniaceae. It also suggests that the antiraphal vascular bundle and perispermy originated secondarily in Trimeniaceae as previously inferred from the phylogeny and character distribution in the extant basalmost angiosperms. The fossil seed provides the first evidence that Trimeniaceae was distributed in a midlatitude location of the Northern Hemisphere during the Early Cretaceous, when angiosperms radiated extensively, supporting a hypothesis that the extant austral distribution is relict.</p

    Experimental Results for a Two-Material Passive di/dt Limiter

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    The purpose of this paper is to experimentally verify the current limiting characteristics of a two material magnetic device consisting of a ferrite and permanent magnet material. A resonant pulsed excitation source and a 60 Hz ac source are used to test the characteristics of the device. The experiments confirm that there is a saturated and unsaturated inductance operating region and a current limiting and loss of current limiting kneepoint

    Application of Giant Magnetoresistive Sensor for Nondestructive Evaluation

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    金沢大学環日本海域環境研究センター生体機能計測研究部門This paper describes the applications of spin-valve type giant magnetoresistance sensor (GMR) for nondestructive evaluation. One is the eddy-current testing (ECT) probe which enables us to inspect micro defect and to detect micro conductors. The proposed ECT probe was applied to the inspection of bare printed circuit board and the recognition of micro solder bead for IC surface mounting package. Another is the measurement of the density of magnetic fluid injected in living body for the hyperthermia treatment. For this purpose, the needle type GMR probe was developed. The experimental results verify the possibility of the proposed system. © 2006 IEEE

    Application of the Repulsive-Type Magnetic Bearing for Manufacturing Micromass Measurement Balance Equipment

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    Many applications of the single-axis controlled repulsive-type magnetic bearing have been proposed earlier. However, both passive and active magnetic bearings are employed in most of such systems. In this paper, a new permanent magnet (PM) repulsive-type micromass measurement system is developed. The repulsive forces of the PM section are used effectively to keep the radial direction stable where the electromagnets, control circuits, and peripheral devices needed for controlling the unstable direction are simplified. The configuration, control design, and operating characteristics of the proposed system have been presented
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