• 한국재료학회지
• /
• 제16권7호
• /
• pp.439-444
• /
• 2006

An apparatus capable of melting and solidifying various materials containerlessly in high vacuum via electrostatic levitation (ESL) has been developed for finding materials with new or improved properties and further building a database for processing materials in microgravity. Containerless solidification of semiconductors, metals, and alloys such as Si, Zr, Nb, Mo, $V_3Si$, and boron carbides has been carried out to test how various materials at how high temperatures can be processed by ESL. The materials in levitation became spherical at melting by their own surface tensions which were ideal for measuring intrinsic thermophysical properties of materials in the liquid state. Multiple cycles of melting and cooling were reproducibly repeated and radiative cooling curves were recorded.

• 물과 미래
• /
• 제25권2호
• /
• pp.99-110
• /
• 1992

담수화호에서는 온도 및 염도차에 의하여 성층류가 발생하며 수심이 깊은 담수화호의 경우 그 형상이 더욱 뚜렷하다. 본 연구는 깊은 담수화호를 대상으로 내부환경면이 잘 발달된 이층류에 있어서 저층배수관의 유출수 염분농도를 실험을 통하여 규명하였다. 실험에 이용된 저층배수관은 세가지 유형으로 유입층과 배수관의 유출수 염분농도차를 무차원으로 수식화 하였고 유입층의 상층부 흐름이 순간적으로 배수되는 밀도층의 한계조건을 밀도 Froude수와 배수관의 직경 및 수심의 함수로 방정식을 유도하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 하계학술대회 논문집 C
• /
• pp.1543-1546
• /
• 1994

Ignitabilility of explosive gas mixture by spark of dry cell in case of short circuit by accident was studied for the purpose of evaluation of intrinsically safe characteristics of dry cell that manufactured in Korea. IEC type spark test apparatus, $21{\pm}2$ Vol% of hydrogen - air mixture, and dry cell that produced in Korea was used for the experiment. The result of this research could be used for design, manufacturing, and using the intrinsically safe electrical apparatus.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
• /
• pp.612-617
• /
• 1999

This study was carried orut considering the aspect of economical and measuring time to investigate through the literature review of the test methods and advantage -disadvantage of infilltrometer and porous probe test apparatus. SSRI and BAT permeameter could obtain results within relatively short time and measure low permeability. SDRI is able to obtain values the accuracy and representative of the overall in-situ. BAT permeameter is to suitable because it can obtain the values accurately and quickly . Therefore the apparatus cost can be to disregard. In-situ measurement using in-situ hydralulic conductivity test equipment is able to do for the engineer to quickly identify and remediate problem areas due to construction or material changes.

• 대한가정학회지
• /
• 제26권2호
• /
• pp.69-79
• /
• 1988

This study was to increase the experimental learning effect of textile materials in middle and high school. To this study, three kinds of simply devised apparatus were used for warmth retaining test, air permeability test and static electricity test. Two classes were chosen in a girls' high school comparing learning effect and classified the theoretical learning group and the experimental learning group. In the experimental group, a teaching plan to teach the properties of textile materials was made to use these apparatuses. The results were. 1. In the interest on the unit either the theoretical learning group or the experimental learning group were not different significantly. 2. In the items facilitation of motivation, unsatisfied desires and prevention of failure, effect of transfer and development of inquiry power, both groups were significant. 3. For the purpose of comparing the learning effect, two groups were examined for determining the level of understanding after teaching properties of textile materials. The mean value of the experimental learning group was higher than that of the theoretical learning group. The experimental learning group had more higher markers(over the point of 90) than the theoretical learning group.

• 유공압시스템학회:학술대회논문집
• /
• 유공압시스템학회 2010년도 춘계학술대회
• /
• pp.18-24
• /
• 2010

Because of the increasing demand on the high precision and high response of a machinery, electronic control valves are widely adopted at various application fields. This paper studies on the static characteristic of a first-stage proportional pressure control valve. At first an experimental apparatus including hyd. pump variable speed inverter, pressure and data aquisition system was setted up with the experimental apparatus, various tests such as P-Q-W test, hyd, pump, dynamic, static, frequency response test of the proportional valve was carride out and the results are discussed.

• 대한소아치과학회지
• /
• 제23권4호
• /
• pp.887-892
• /
• 1996

For the purpose of assessing the utility and cautionary aspects of pulse oximetry of which use is rapidly increased, it was applied to the maladaptive child patients with sedative drugs and evaluated the results. When pulse oximeter was used alone for vital sign monitoring, it was thought impossible to exclude the false alarm or false silence by various causes. To minimize or remove these misunderstanding, operators should have a extensive knowledge not only on the factors affecting the operation of this apparatus but also on the potential of misoperation. To review the present status of increasing risk of hypoxia during the sedation, it was thought unreasonable to solely depend upon this apparatus for vital sign monitoring. By combining with more accurate and auxiliary monitoring devices, pulse oximetry will be of greater value and can meet the clinical needs and conveniences.

• 한국수소및신에너지학회논문집
• /
• 제27권6호
• /
• pp.628-635
• /
• 2016

Natural gas reformed hydrogen is used as a fuel of fuel cell vehicle, PSA process is used for the purification of reformed hydrogen. In this study, the performance of CO adsorbent in PSA process was evaluated. Zeolite adsorbents used in the commercial PSA process is used. The physical and chemical properties of adsorbents were characterized using BET apparatus, XRD, and FE-SEM. The breakthrough apparatus modified from GC was used for the CO breakthrough experiment, the quantitative analysis of CO adsorption capacity was performed using CO breakthrough curve. Zeolite 10X and 13X showed superior CO adsorption capacity than activated alumina. The CO adsorption capacity of zeolite 10X is more than twice of zeolite 13X even the BET surface area is low. It seems that the presence of $Ca^{2+}$ cation in zeolite 10X is beneficial to the adsorption of CO.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.540-542
• /
• 2003

In the high-power tests to be performed on electrical apparatus as circuit-breaker, load switch, fuse, transformers, insulators, cable and so on, the results of tests on these apparatus are extremely important to evaluate the performance of test object. The reliability of the results depends on the reliability of measuring systems used in the laboratories where tests are performed. This paper deals with factors of uncertainty and describes estimation of uncertainty in new measuring system used in high-power testing LAB. 1 in KERI.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.493-494
• /
• 2008

During the last years hollow core insulators started their success story in the field of high voltage engineering for electrical apparatus, substituting porcelain insulators. The termination, also named top and bottom fittings are used for the connection to the rest of the electrical apparatus. The top and bottom flange are attached to the composite to transmit mechanical load and also ensure the gas tightness. They are bonded by epoxy glue with a glass transition temperature of about $130^{\circ}C$-$150^{\circ}C$ the glass reinforced epoxy tube of filament winding. This paper describes the results of a study on the bonded joints of fiber reinforced epoxy tube and cast aluminum. This suggests that surface roughness and glue types play an important role in evaluating of gas sealing capability on the flange and fiber reinforced epoxy tube in the composite hollow bushing.