著者
金子 暁子 野村 康通 高木 周 松本 洋一郎 阿部 豊
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集B編 (ISSN:18848346)
巻号頁・発行日
vol.78, no.786, pp.207-217, 2012 (Released:2012-02-25)
参考文献数
14
被引用文献数
8 19

Microbubble has distinguished characteristics of large surface area to unit volume and small buoyancy. Recently microbubble generators with low energy and high performance are required to wide applications. In the present study, we propose one new effective technique to generate tiny bubbles with less than 200μm diameter utilizing a venturi tube under high void fraction condition. The objective of the present study is to elucidate the mechanism of bubble breakup phenomena in the venturi tube and to clarify the effects of parameters which are necessary to realize an optimum system experimentally. Under low velocity condition, bubbles which were observed with a high speed camera parted gradually in a wide region. On the contrary under high velocity condition, bubbles expanded after passing through the throat and shrank rapidly. Since the speed of sound in gas-liquid system is extremely lower than that of single-phase flow, the bubble breakup phenomenon in the venturi tube is explained as the supersonic flow in a Laval nozzle. With rapid pressure recovery in diverging area, expanding bubbles collapse violently. The tiny bubbles are generated due to the surface instability of shrinking bubbles.
著者
久門 良明 渡邉 英昭 松本 洋明 井上 明宏 岩田 真治 大上 史朗 大西 丘倫
出版者
一般社団法人 日本脳卒中の外科学会
雑誌
脳卒中の外科 (ISSN:09145508)
巻号頁・発行日
vol.37, no.1, pp.18-25, 2009 (Released:2009-09-29)
参考文献数
22

We evaluated the effectiveness of assist-systems such as endoscopy, navigation, and motor evoked potential (MEP) monitoring in terms of improving the safety and accuracy of surgery for cerebrovascular diseases. Since January 2000, the following devices have been used at our institution to assist in surgical procedures: an endoscope (diameter, 2.7 or 4.0 mm; tip angle, 30° or 70°) in 69 surgical procedures to treat cerebral aneurysms, a navigation system (Stealth Station) in 22 operations for cerebral aneurysms and arteriovenous or cavernous malformations, and MEP monitoring (bipolar or mono-polar electrical stimulation of the motor cortex and EMG recording of the face, trunk and upper extremity contralateral to the stimulated side) in 11 operations for cerebral aneurysms or arteriovenous malformations. Endoscopy allowed visualization of the anatomical relationship between the aneurysm neck and the parent or perforated artery before clipping, and the location of the clip tip, occlusion of the perforated artery, or stenosis of the parent artery could be evaluated after clipping. Postoperative MR and/or CT images revealed an asymptomatic infarction of perforated artery in 4 patients. Navigation allowed prediction of the sites of aneurysms, cavernous malformations, or of the feeding arteries of arteriovenous malformations. This resulted in accurate approaches to these structures, although a brain shift in some patients was recognized by ultrasound imaging linked to the navigation system. Although MEP monitoring should have predicted postoperative motor function, MEP findings after clipping the neck of aneurysms or obliterating the arteriovenous malformation of a feeding artery were normal in all of the analyzed patients. Postoperative convulsive seizures developed in patients as a result of 20 mA of bipolar electrical stimulation. Endoscopy, navigation, and MEP monitoring are considered helpful for safe and accurate surgical treatment of cerebrovascular diseases, although the disadvantages of these systems should also be considered.
著者
飯田 彰 松本 洋亘 富岡 清 和田 俊一
出版者
天然有機化合物討論会実行委員会
雑誌
天然有機化合物討論会講演要旨集 44 (ISSN:24331856)
巻号頁・発行日
pp.617-622, 2002-09-01 (Released:2017-08-18)

DNA topoisomerases are nuclear enzymes responsible for biological processes of DNA metabolism such as replication, transcription, recombination and chromosome segregation at mitosis. Therefore, compounds that inhibit these enzymes as the primary cellular target are of special interest since those are promising candidates for anticancer drugs. Our previous studies demonstrated that the ortho-quinone or catechol moiety in aza-deoxypodophyllotoxin analogues plays a critical role in showing topoisomerase II (topo II) enzyme inhibition, in which proton transport during cutting and resealing of DNA is presumed to be blocked by a small structural unit like ortho-quinone. We report herein the synthesis and biological evaluation of nucleoside analogues as novel topo II inhibitors that are hybrids with aza-podophyllotoxin analogues. Our synthesis contains a Michael addition reaction of 1,3-dithianes to chiral butenolide 2, an equivalent to the deoxyribose moiety of a nucleoside, and a Silyl-Hilbert-Johnson reaction as key reactions. As predicted, ortho-quinone 1 and catechol 6 showed topo II inhibition, while dimethoxy derivative 7 was inactive. Unexpectedly, intermediates 6 and 8 were shown to be potent inhibitors. In addition to the active nucleosides, it was found that several lactone derivatives lacking a thymine base also inhibited topo II, indicating that a thymine base is not requisite to topo II inhibition. Structure-activity relationship of these lactone derivatives showed that the presence of the TBS group or dithiane moiety in the molecule is essential for topo II inhibition in the case of non-nucleoside derivatives. Further study is now in progress to examine their possible mechanism of action as topo II inhibitors.
著者
伊藤 良三 石坂 耕一 根葉 保彦 松本 洋和
出版者
The Institute of Electrical Engineers of Japan
雑誌
電気学会論文誌. D, 産業応用部門誌 = The transactions of the Institute of Electrical Engineers of Japan. D, A publication of Industry Applications Society (ISSN:09136339)
巻号頁・発行日
vol.131, no.4, pp.667-668, 2011-04-01
参考文献数
2
被引用文献数
1 3

Single-phase boost rectifier with a resonant snubber switch cell is studied. The resonant snubber switch cell consists of an only active power switching device and a LC resonant circuit, and can also provide the necessary control over the current. To turn on and off an active power device under the soft switching conditions, the rectifier is operated in the discontinuous conduction mode (DCM). The experimental results under the charge control confirm that the input current can nearly be wave-shaped sinusoidally with a near-unity power factor.
著者
宮内 信之助 下村 雅人 山内 健 大島 賢治 松本 洋一 迎 勝也
出版者
公益社団法人 高分子学会
雑誌
高分子論文集 (ISSN:03862186)
巻号頁・発行日
vol.58, no.5, pp.227-232, 2001-05-25 (Released:2010-11-22)
参考文献数
9

きのこ [マイタケ (Grifola frondosa: GF) ] の柄を粉末化し, それをアセトンと蒸留水で洗浄することによって, 少し透明感のある白色のGF粉末を得た. このGF粉末存在下で, 硝酸セリウム塩を開始剤として, 水溶媒でアクリルアミド (AAm) の重合を行った. 重合は温度を上げ, GF量を増加させると進み, 60℃で91%の重合収率を得た. 水に対する見かけの可溶化率を調べたが, アクリルアミドの重合がGFの可溶化を助けた. 洗浄前と洗浄後のGF, およびGFを水またはアセトンで洗浄した後の〓液, GF存在下でのGF-ポリアクリルアミド (PAAm) 複合物の水洗浄後の〓液について, 1HNMR測定を行った. その結果, アセトンによる洗浄では, 主として脂肪酸が抽出され, 糖質類は抽出されなかった. 一方, 水による洗浄では, α型の糖質類が抽出され, ポリアクリルアミドと複合化されてもβ型のものは抽出されにくかった.
著者
松本 洋一 久保田 周治 加藤 修三
出版者
一般社団法人電子情報通信学会
雑誌
電子情報通信学会技術研究報告. DSP, ディジタル信号処理 (ISSN:09135685)
巻号頁・発行日
vol.94, no.57, pp.57-63, 1994-05-20

本報告は,CMOS0.8μmマスタースライス(2V動作)を用い開発した,低消費電力化パーソナル通信用復調器LSIについて述べている。開発したLSIは,通信品質の改善および消費電力の低減を図るため新たに以下の方式を用いている。(1)π, 4位相回転操作にキャリアフィルタ帯域が可変な逆変調キャリア再生方式,(2)プリアンブル位相情報を用いた初期クロック位相推定型クロック再生方式,(3)低消費電力化を考慮したパルスカウント型直交検波方式,(4)プリアンブル位相情報を用いたバースト検出方式.試作LSIによる評価試験により,本LSIはパーソナル通信環境下において,遅延検波復調器に比べエラーフロアを40%低減,フロア誤り率10%における所要Eb/Noを3dB改善することが確認された。
著者
日置 雅和 河並 崇 松本 洋平 堤 利幸 中川 格 関川 敏弘 小池 帆平
出版者
一般社団法人電子情報通信学会
雑誌
電子情報通信学会技術研究報告. RECONF, リコンフィギャラブルシステム (ISSN:09135685)
巻号頁・発行日
vol.109, no.198, pp.37-42, 2009-09-10
被引用文献数
3

我々の研究グループは,ソフトウェアとハードウェアの観点から,電力を再構成可能なFPGAである"Flex Power FPGA"の予備的評価を行ってきた.今回,我々はFPGAとしての回路再構成機能に加えて,電力再構成機能を有するFlex Power FPGAチップの設計と試作を90nm CMOS技術で行った.また,デバイス設計と同時に,Flex Power FPGAのための専用ソフトウェアを開発した.専用ソフトウェアを用いて16ビットカウンタ回路のビットストリームを生成しチップへ実装した.その結果,設計したチップ上で16ビットカウンタの完全動作を確認した.
著者
松本 洋幸
出版者
慶應義塾福沢研究センター
雑誌
近代日本研究 (ISSN:09114181)
巻号頁・発行日
no.29, pp.165-204, 2012

特集 : 大正期再考はじめに第1章 「三井・企業城下町」大牟田第2章 市政の二大政党化と三井鉱山第3章 「大衆化」時代の市政と三井鉱山おわりに
著者
高木 周 松本 洋一郎 黄 華雄
出版者
一般社団法人日本機械学会
雑誌
日本機械学會論文集. B編 (ISSN:03875016)
巻号頁・発行日
vol.61, no.586, pp.1976-1983, 1995-06-25
被引用文献数
10

A numerical method is developed to simulate the unsteady axisymmetric flow with a free surface. The method is based on a finite-volume solution of the equations on an orthogonal curvilinear oordinate system. A new iteration technique is used for the boundary condition of the free surface to stabilize the solution. The method is applied to simulate an unsteady motion of a single deformed bubble rising through a quiescent liquid. The numerical results show quantitatively good agreement with those of experiments and calculations of others. In the present study, the transitional phenomena of the initially spherical bubble in reaching the steady state are investigated. It is known experimentally that the rising bubble begins to show an unsteady three-dimensional (spiral or zigzag) motion beyond certain critical Reynolds and Weber numbers. Our numerical results of the axisymmetric flow show unsteady shape oscillations in the parameter range of the three-dimensional motions.