1011 research outputs found
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One Method for Measuring Moment of Inertia of DC Machine with Brush (1)
Get PDFpublisherThis paper suggests one method for measuring the moment of inertia of rotary machines with brushes. They are gotten by measuring mechanical losses on no load test and stopping times on braking test. These deal with four cases of a motor, a motor-driving motor-generator, a generator, and a generator-driving generator-motor.departmental bulletin pape
Magnetic float property for shield film of high Tc superconductor
Get PDFpublisherRecent YBa2Cu3Oy superconductors have made by a combination process of solid state reaction and partial melbing. In air YBa2Cu3Oy phase diagram shows a peritectic point at about 1010℃ where Y2BaCuO5, a liquid and YBa2Cu3Oy coexist. The Y2BaCuO5 acts as the nucleation site for peritectic reaction. The nureacted Y2BaCuO5 seems to act as a flux pinning center. We fabricated bulk superconductors to put YBa2Cu3Oy and Y2BaCuO5, during partial melting. As the result, we have found that Y2BaCuO5 can penetrate into YBa2Cu3Oy bulk superconductors. This bulk superconductor showed long magnetic float property than no penetrated Y2BaCuO5.departmental bulletin pape
Influences of Vaned Diffuser of Centrifugal Pump on Air-Water Two-phase Flow Performance
Get PDFpublisherExperiments of air/water two-phase flow performance were carried out using a centrifugal pump with three kinds of open impellers, each of which has a different outlet blade angle. And influences of installation of diffuser vanes downstream from the impeller were investigated experimentally. Results are described as foilows. Diffuser vanes, installed closely to the impeller outlet, with the appropriate angle and shape are effective in suppressing the
elongation of the gas acctumulating region. And the effectiveness of installation of diffuser vanes is more remarkable when the impeller has a large blade outlet angle in low water flow rate.departmental bulletin pape
Facilities for Study on Arc Welding in Space - Construction and Characteristics -
Get PDFpublisher平成11年度に電子制御工学科に設置した「宇宙アーク溶接の研究設備」の構成と特徴を報告する。この設備は、1．最大エネルギー6kJのコンデンサ電源、2．波形調整用コイル、3．組立式真空チャンバー、
4．高真空排気装置、5．ロゴウスキーコイル式電流センサー、6．高速デジタルメモリスコープ等で構成し、最大電流約8kA、半値幅約13msの真空中パルスアーク放電の発生及びその電流・電圧波形の計測、記録、ハードコピーが可能である。また、この設備は電磁気学の実験教育にも活用でき、鉄心入りコイルの磁気飽租現象や環状導体の磁気浮上について検討した結果を述べる。departmental bulletin pape
A Study of CO2 Gas Absorption into and Desorption from Monoethanolamine Aqueous Solution
Get PDFpublisherIn this paper the absorption rate and the desorption rate of CO2 gas by simultaneous measurement of pH and CO2 concentration in HCl and monoethanolamine(MEA) aqueous solution were studied by blowing CO2 gas and N2 gas through an upward vertical glass nozzle.
The results are smmarized as follows.
(1) In the case of CO2 gas absorption into MEA aqueous solution, the reaction of CO2 and MEA was considered as
pseudo first erder irreversible reaction while CO2 concentration was maintained at zero. The values of activation energies of the apparent absorption rate, (S/V)kL*, in MEA aqueous solution and (S/V)kL in HCl aqueous solution were found to be 20.7kJ/mol and similar 12.3kJ/mol, respectively. A linear relationship was found between (S/V)kL*, which was 3.2 times as much as (S/V)kL, and CO2 gas flow. It seems that the process of mass transfer in liquid film was the rate determining step in this reaction.
(2) In the case of desorption from MEA aqueous solution, the apparent desorption rate, (S/V)kL', was equal to that from HCl solution. The value of activation energy of(S/V)kL' in MEA aqueous solution was 17.2kJ/mol and as much as 13.8kJ/mol in HCl aqueous solution. A linear relationship between (S/V)kL' and N2 gas flow were found. It seems that the process of mass transfer in liquid film was the rate determining step in this reaction.departmental bulletin pape
The Development of High Efficiency Booster Circuit Suitable for Embedded Power Supply On IC by using PSpice
Get PDFpublisherRecently semiconductor technology has advanced, and both digital circuits and analog circuits have become to be fabricated on one chip. It is importat to investigate an analog circuit design as well as a digital circuit from such a background. In this paper the new analog booster circuit is proposed to be fabricated into a digital chip. The booster can generate an output voltages two times higher than a conventional one, like a charge pump booster. The booster adopts both the charge pump technique and the series parallel alternating switched capacitor technique. The circuit is simulated by PSpice software. The theoretical analyses and simulation results show the effectiveness of the proposed circuit. The proposed booster
suitable for embedded power supply circuit in MOSIC.departmental bulletin pape
A Field Survey of a Present Security Situation of the Internet Servers
Get PDFpublisherThe Internet servers such as DNS, mail and WWW ones play an important role in the Internet connection. A security situation of these servers has attracted interest recently. We examine the security situation of the servers attached to our college and a neighboring enterprise. The security situation is checked by open tools of COPS, SATAN (SAINT) and mail relay check site. We report collecting results of our check, then discuss for the conditions to realize a secure server.departmental bulletin pape
Electro-optical Characteristics of PDLC
Get PDFpublisherLiquid crystal display devices by TN, STN, and TFT methods have been widely used for note type computers, TV set, measuring instruments, and others. The author has investigated the electro-optical characteristics of liquid crystal cells by PDLC (polymer dispersed liquid crystal) method. PDLC cells were made by changing the mixing ratio of polymer and nematic liquid crystal, the cell thickness and the irradiated time of ultra violet rays. Electro-optical characteristics of PDLC cells were investigated on the TV, the response time and the cell thickness charactenistics by applying the sine wave voltage of 1 KHz from 0 to 40 Vrms. Experimental results showed that the cell with the mixing ratio of 1:3:4 (plc1:bl01:bl36) has higher contrast and the sharpest characteristics on the T-V characteristics, and the cell with the irradiated time of 400 seconds had high contrast and good characteristics compared with the cells having the irradiated times of 100 and 1000 seconds. The response time was the 60~90 mS for all cells. The cells with thin film had the higher contrast ratio than the cells with thick film.departmental bulletin pape
A Tentative Plan of Semi-special Cultivated Physics Education Ⅰ
Get PDFpublisherAn improvement of physics education in college and in high school is proposed for the sake of fascinating many students in physics. The interesting events in science of the 20th century should be abundantly taken up in the subject of physics. Two items of quamtum mechanics and the world of Einstein are exemplified among many items in different manner from ordinary one.departmental bulletin pape