528 research outputs found
Characterized Hysteresis Model and a Magnetic Pulse Compression Circuit
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
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
<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
An Adaptive Node Relocation Procedure in FEM with Its Application to Deformation Analysis of Ground
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Magnetization anomaly of Nb3Al strands and instability of Nb3Al Rutherford cables
Using a Cu stabilized Nb{sub 3}Al strand with Nb matrix, a 30 meter long Nb{sub 3}Al Rutherford cable was made by a collaboration of Fermilab and NIMS. Recently the strand and cable were tested. In both cases instability was observed at around 1.5 Tesla. The magnetization of this Nb{sub 3}Al strand was measured first using a balanced coil magnetometer at 4.2 K. Strands showed an anomalously large magnetization behavior around at 1.6 T, which is much higher than the usual B{sub c2} {approx} 0.5 Tesla (4.2 K) of Nb matrix. This result is compared with the magnetization data of short strand samples using a SQUID magnetometer, in which a flux-jump signal was observed at 0.5 Tesla, but not at higher field. As a possible explanation for this magnetization anomaly, the interfilament coupling through the thin Nb films in the strands is suggested. The instability problem observed in low field tests of the Nb{sub 3}Al Rutherford cables is attributed to this effect
High-density double-layer printed circuit board inspection by using high-frequency eddy-current probe
岩原, 正
Improvement on defect detection performance of PCB inspection based on ECT technique with multi-SV-GMR sensor
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 improvement on the defect detection performance of printed circuit board (PCB) inspection based on the eddy-current testing (ECT) technique with the multispin-valve giant magnetoresistance (SV-GMR) sensor. To obtain the ECT signal in the same scanning line, SV-GMR sensors are mounted on the exciting coil in the same column parallel with the scanning direction. Harmonic analysis based on the Fourier transform is used to analyze the signal from the SV-GMR sensor in order to increase scanning speed. Then signal averaging is applied to the ECT signal in order to improve the signal-to-noise ratio. Experimental results are performed to verify the inspection performance. © 2007 IEEE
Experimental Results for a Two-Material Passive di/dt Limiter
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
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