334 research outputs found
Bending Deformation and Fatigue Properties of Precision-Casted TiNi Shape-Memory Alloy Brain Spatula
Ti Ni ゴウキン アツエンバン ノ シュウゴウ ソシキ ト ケイジョウ キオク トクセイ ニカンスル ケンキュウ
従来、Ti-Ni合金を薄膜化するためには、スパッタ法や、急冷凝固法により作成するのが一般的であったが、本研究により、30μmの厚さの圧延材の作成が可能になった。圧延による薄膜化の方法が開発された結果、20μm以下の薄膜はスパッタ法で作成し、 ...筑波大学博士 (工学) 学位論文・平成12年3月24日授与 (甲第2344号)標題紙、目次 -- 第1章 序論 -- 第2章 実験方法及び解析方法 -- 第3章 Ti-Ni形状記憶合金薄板の集合組織に及ぼす熱処理温度の効果 -- 第4章 Ti-Ni形状記憶合金薄板の集合組織に及ぼす圧延率の効果 -- 第5章 結論 -- 第6章 謝辞 -- 公開論文の目
Evaluation of Precision-Cast TiNi Shape Memory Alloy Brain Spatula
In order to develop a brain spatula made of a shape memory alloy (SMA), this paper discusses the bending characteristics of a new brain spatula precision-cast in a TiNi SMA. Based on the yield stress and the modulus of elasticity of the copper and the TiNi SMAs, the bending deformation properties of the SMA-brain spatula were estimated by assuming the condition to use the brain spatula as the bending of the strip cantilever. With respect to the SMA-brain spatula for the same length and width as the existing copper one, if the thickness of the conventional rolled-SMA spatula is 1.3 times as large as that of the existing copper-brain spatula,the SMA spatula can hold the same bending rigidity and can be bent by a smaller force than the existing copper one. If the thickness of the new cast-SMA spatula is 1. 2 times as large as that of the existing-copper spatula, the SMA spatula can hold the same bending rigidity and can be bent by the same force as the existing copper one
Characterization Experiments of Secondary Arcs on Solar Arrays: Threshold and Duration
An electrostatic discharge test performed on a solar array panel is one of the important tests carried out before spacecraft launch to ensure spacecraft reliability in orbit. In this study, the effects of secondary arcs on the solar array, which can cause catastrophic accidents, are considered. The sustained-arc threshold of multijunction and silicon solar arrays was investigated to establish the design guidelines for ensuring the safety of satellite solar arrays. In this experimental study, the string voltage, string current, gap length, and solar-cell type were selected as test parameters. Gap lengths were 0.5, 0.8, 1.0, and 2.0 mm. For 0.5 and 0.8mmof gap length, a permanent sustained arc occurred under the condition of 1.5 A of string current for 50, 70, 90, and 110 V of string voltage. Furthermore, temporary sustained-arc duration exponentially increased with increasing string current. Temporary sustained-arc duration longer than 1 ms can serve as a practical alarm for the imminent permanent sustained-arc inception
Statistical Number of Primary Discharges Required for Solar Array Secondary Arc Tests
In the present paper, we propose a method to assess the risk of a secondary arc on a solar array in orbit based on statistical theory. Ground experiments have been carried out to investigate the statistics of temporary-sustained-arc duration. We have found that secondary-arc duration can be modeled as a combination of multiple Poisson distributions. Once we know the formula of the Poisson distribution, we can easily calculate the probability of a secondary arc lasting longer than an acceptable limit. The quantity of secondary-arc-duration data needed to define the Poisson distribution formula has been discussed. Assuming that thousands or tens of thousands of primary arcs occur in orbit, if the average duration of secondary arcs in the test is less than 5% of the acceptable limit for secondary-arc duration, we can greatly reduce the number of experimental trials to 10 or less in most cases
Ect2 and MgcRacGAP regulate the activation and function of Cdc42 in mitosis
Although Rho regulates cytokinesis, little was known about the functions in mitosis of Cdc42 and Rac. We recently suggested that Cdc42 works in metaphase by regulating bi-orient attachment of spindle microtubules to kinetochores. We now confirm the role of Cdc42 by RNA interference and identify the mechanisms for activation and down-regulation of Cdc42. Using a pull-down assay, we found that the level of GTP-Cdc42 elevates in metaphase, whereas the level of GTP-Rac does not change significantly in mitosis. Overexpression of dominant-negative mutants of Ect2 and MgcRacGAP, a Rho GTPase guanine nucleotide exchange factor and GTPase activating protein, respectively, or depletion of Ect2 by RNA interference suppresses this change of GTP-Cdc42 in mitosis. Depletion of Ect2 also impairs microtubule attachment to kinetochores and causes prometaphase delay and abnormal chromosomal segregation, as does depletion of Cdc42 or expression of the Ect2 and MgcRacGAP mutants. These results suggest that Ect2 and MgcRacGAP regulate the activation and function of Cdc42 in mitosis
Continuous CH4 measurements with the NIPR CFA system
第6回極域科学シンポジウム分野横断セッション:[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日(木) 国立極地研究所1階交流アトリウ
High Resolution Continuous Flow Analysis System developed at the Ice Core Research Center National Institute of Polar Research
第6回極域科学シンポジウム[OM] 極域気水圏11月16日(月) 統計数理研究所 セミナー室2(D304
A detailed protocol for perspiration monitoring using a novel, small, wireless device
Perspiration monitoring can be utilized for the detection of certain diseases, such as thermoregulation and mental disorders, particularly when the patients are unaware of such disorders or are having difficulty expressing their symptoms. Until now, several devices for perspiration monitoring have been developed; however, such devices tend to have a relatively large exterior, considerable power consumption, and/or less sensitivity. Recently, we developed a small, wireless device for perspiration monitoring. The device consists of a temperature/relative humidity (T/RH) sensor, battery-driven small data logger, and silica gel as a desiccant in a small cylindrical exterior. The T/RH sensor is placed between the detection windows (through which the water vapor from the skin enters) and the silica gel. The underlying principle of the perspiration monitoring device is based on Fick\u27s law of diffusion, which means that water vapor flux from the skin to the silica gel (i.e. transepidermal water loss and perspiration) can be captured by change in humidity at the T/RH sensor. In addition, a baseline subtraction method was adopted to distinguish perspiration and transepidermal water loss. As shown in the previous report, the developed device can monitor the perspiration at any sites of the body in an easy, wireless manner. However, detailed methods of how to use the device have not been disclosed yet. In this article, therefore, we would like to show the point-by-point tutorials of how to use the device for perspiration monitoring, by showing the sympathetic activity test with the sympathetic skin response monitoring as an example. © 2016 Journal of Visualized Experiments.Embargo Period 24 month
Development of a small wireless device for perspiration monitoring
A small and wireless device that can capture the temporal pattern of perspiration by a novel structure of water vapor collection combined with reusable desiccant has been developed. The novel device consists of a small cylindrical case with a temperature/relative humidity sensor, battery-driven data logger, and silica gel (desiccant). Water vapor of perspiration was detected by the change in relative humidity and then adsorbed by silica gel, allowing continuous recording of perspiration within a closed and wireless chamber, which has not been previously achieved. By comparative experiments using the commercially-available perspiration monitoring device, the developed device could measure perspiration as efficiently as the conventional one, with a normalized cross coefficient of 0.738 with 6 s delay and the interclass correlation coefficient [ICC(2, 1)] of 0.84. These results imply a good agreement between the conventional and developed devices, and thus suggest the applicability of the developed device for perspiration monitoring. © 2015 IPEM.Embargo Period 12 month
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