• Title/Summary/Keyword: Direct contact

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A Note on Direct Contact Exchangers (직접방식 열교환기와 전달특성)

  • 김석현
    • Journal of the KSME
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    • v.35 no.9
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    • pp.829-835
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    • 1995
  • 통상의 열교환기에서 전열면이 제거된 형태의 직접열교환을 통하여 제작비나 열전달 특성에 큰 효과를 얻을 수도 있어 에너지이용 합리화에 기여하는 특성과 사례를 언급하였다. 또한 통상의 열교환기 설계와 다른 매질간의 공유계면에서 발생 가능한 전달특성을 위주로 설계상의 일부 유의사항을 기술하였다. 직접열교환의 기술축적은 상변화를 동반하는 열전달(two phase heat transfer) 문제의 기초지식은 물론, 염수플랜트(desalination)의 기본 요소설계, 원자로의 냉각계 통사고(LOCD)대책, 기타 냉각탑, 탱크가열, 증발기(evaporator), 건조장치(drier), 각종 기계, 화공 공정장치 설계 등 매우 광범위한 기술파급 효과도 기대할 수 있으므로 관련 기술자들의 많은 관심을 기대한다.

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A Study on the Wear Monitoring Technique for Diamond Core Drill (다이아몬드 코어 드릴의 마멸 검출에 관한 연구)

  • 유봉환
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.4 no.2
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    • pp.38-45
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    • 1995
  • The diagnosis and monitoring system of abnormal cutting condition is necessary to realize precision machining proces and factory automation, which are final goal of metal cutting in order to develop this system, theimage processing technique has been investigated in machining process. In theis paper, the measurement system of tool wear using computer vision is designed to detect the wear pattern by non-contact and direct method and get the realiable wear information about cutting tool. We measured the area of the side and front part of the diamond core dril which is used in 40kHz ultrasonic vibration machine.

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Fabrication of PDMS Microlens Using Electrohydrodynamic Atomization (정전분사를 이용한 PDMS 마이크로렌즈의 제작)

  • Kang, Tae-Ho;Yang, Sang-Sik
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.10
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    • pp.1841-1846
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    • 2008
  • In this paper, we present the fabrication of microlens by electrohydrodynamic atomization(EHDA) of PDMS prepolymer. The diameter and contact angle of PDMS microlens can be altered by changing the applied voltage and substrate temperature at the experimental setup. It is considered that PDMS microlens can be integrated into the Lab-on-a-chip directly without any photolithographic process by EHDA. The property of PDMS microlens is confirmed by transmitting and measuring the Gaussian beam through microlens.

A Development of SFD for the measurement of rotational velocity vector (회전 속도 Vector 계측을 위한 공간필터 검출기의 개발)

  • Go, Hyun-Min;Rho, Do-Hwan
    • Proceedings of the KIEE Conference
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    • 1999.11c
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    • pp.621-624
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    • 1999
  • In this paper, we propose the non-contact method to measure rotational speed vector using spatial filtering method. The rotational speed $\omega$ is known by the frequency of output sinusoidal signal direct proportional to that and the rotational direction is given by the phase delay from the weighting function design of spatial filter.

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Current Status of Liquid-Free Superconducting System Develo (액체를 사용하지 않는 초전도시스템의 개발 동향)

  • 장호명
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 1999.02a
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    • pp.1-6
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    • 1999
  • The recent progress in the new cooling technology for superconducting systems without liquid cryogens is briefly presented. In these conduction-cooled systems, the super-conducting magnets are cooled by a direct contact with closed-cycle cryocoolers and only electricity is supplied to maintain the cryogenic temperatures. It is reported that at least 20 conduction-cooled (low Tc or high Tc) super- conducting systems have been constructed, tested, or commercially used worldwide. Some of the significant design issues are discussed in comparison with the conventional liquid-helium cooled systems.

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Classification and Applications of Direct Contact Condensation Heat Exchanger (직접접촉응축 열교환기의 분류 및 응용)

  • 오후규;김성규
    • Journal of the KSME
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    • v.35 no.7
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    • pp.638-646
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    • 1995
  • 직접접촉 얼교환 기술은 냉각탑, 접촉급수 가열기 및 공기분리기 등과 같은 장치에 예전부터 이용되어 왔는데, 그 주요한 적용이유는 가열유체와 수열유체의 사이에 일어나는 전열이 일반 열교환기와는 달리 고체벽(금속 열전달표면)을 통과하지 않고 열교환을 함으로써, 종래의 열교 환기에 비하여 상대적으로 설비의 간단화, 부식 및 스케일 부착문제가 경감됨에 따른 적은 유 지보수비 및 높은 열전달률을 얻을수 있는 이점이 있으며, 저 온도차에서의 효율적인 사용이 가능하기 때문이다. 이 글에서는 직접접촉응축 현상의 장점을 이용하는 직접접촉식 교환기의 구조와 형태, 그리고 그 응용분야에 대해서 알아보고자 한다.

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A Survey of Disaster Medical Drill in Korea (국내 재난의료훈련 현황의 고찰)

  • Wang, Soon-joo
    • Journal of the Society of Disaster Information
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    • v.6 no.2
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    • pp.107-117
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    • 2010
  • The disaster preparedness system in Korea has been developed in spite of many obstacles, but there are still many problems especially on actual preparedness including disaster drill and disaster medical system. Disaster drills performed by wide regional emergency medical centers for one years were analyzed based on the disaster drill report and additional compensation of incomplete data by direct contact with the participating institutions. On the disaster medical drills in Korea, it is necessary to emphasize drills on various types of disaster, active participation of medical personnels, drills combined with various types of related institutions, process of disaster medical aspect.

Knowledge and Performance of Universal Precautions by Nursing Students (일부 간호대학생의 혈액매개질환 예방 지침에 대한 지식과 실천 정도)

  • 김경미;김민아;정여숙;김남초
    • Journal of Korean Academy of Nursing
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    • v.29 no.4
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    • pp.929-939
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    • 1999
  • The purpose of this study was to identify knowledge of universal precautions and its performance in practice. The research was conducted from November 2 to 30, 1998. A total 515 student nurses ; 249 from a baccalaureate nursing college and 266 from second and third year of a 3-year community nursing college were surveyed. The results are as following : 1. The average score for universal precautions knowledge was 270.41$\pm$19.43/300(range 150-300). The results showed that 99.2% of students avoid injury from used needles, 98.6% answered that they always wash their hands if they had contact with the patient's blood and they always dispose of used needles in special collectors (97.7%) for needles. But, 39.2% responsed that they dispose of used needles after recapping them. 2. The average score for universal precautions knowledge of the senior students in the 4-year college was the highest (277.65$\pm$13.99). 3. The average score for the performance of universal precautions knowledge was 53.18 $\pm$5.91(range 14-70). The items : ‘I cautiously avoid injury from the used needles’(4.92$\pm$0.33), ‘I always wash my hands if there has been contact with the patient's blood’(4.91$\pm$0.34), and ‘I always disposed of used needles in the appropriate collector’(4.89$\pm$0.42) showed the highest performance. However ‘I always dispose of used needles after recapping them’(2.19$\pm$1.39) and ‘I always use protection goggles when in danger of contamination’(2.19$\pm$1.20) showed low performance level. 4. The highest average score for universal precautions performance was shown among the second year students in 3-year nursing college (54.19$\pm$6.92) between the groups. It showed that the level of the universal precautions performance was higher for those who had education on university precautions prior to performance of the universal precautions than for those without any prior education. 5. The percentage of students who reported the experience of direct contact with patients' blood and/or body fluids was 42.30%. The experience of direct contact with blood and/or body fluids of the educational group was significantly higher than those were not educated. 6. The most frequent cause of the direct contact was ‘needle pricking and/or skin cut’(63.04%). The most frequent substance with which the students contact was ‘blood’(59.85%). The majority of the sample had answered that the mode of contamination was ‘unknown’(63.54%). The majority of the sample answered that strategies used after contamination included ‘washing with soap’(33.61%). Reviewing the chart of patients or asking other health professionals(28.85%). 7. The number of students who had the experience of a needle stick and/or skin cut was 145(28.16%). The clinical practice places where the incidents occurred were mainly in the internal medicine unit (45.07%) and the surgical unit (31.92%) followed by the intensive care unit and the emergency unit in order. The experience of a needle stick and/or skin cut happened during on intra-muscular injection 47.34% and intravenous injection 21.81%. The causes of the needle stick and/or skin cut were ‘putting the needle cap back on 77(35.81%)’. The number of students who took an appropriate post management blood test and/or vaccination was 27(18.62%). 8. The Pearson Correlation Coefficient between the knowledge of universal precautions and performance of universal precautions in practice showed a positive correlation.

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Performance of Underground Air-to-Water Heat Pump with Direct Contact Heat Exchanger (지하공기-물 직접접촉식 열교환기를 구비한 히트펌프의 성능)

  • Kim, Y.H.;Kang, Y.K.;Sung, M.S.;Ryou, Y.S.;Kim, J.G.;Jang, J.K.
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.172.1-172.1
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    • 2010
  • In Jeju, underground air is used for heating greenhouse and fertilizing natural $CO_2$ gas by suppling directly into greenhouse. But greenhouse heating method by direct supply of underground air has several problems as like low temperature below $20^{\circ}C$ or high relative humidity over 90%. The underground air is inadequate in heating of crops such as mangos, oranges with the growing temperature over $20^{\circ}C$. Also if the relative humidity of greenhouse is kept with over 90%, diseases can strike almost of the crops. And also the ventilation loss becomes larger because the air pressure of inside greenhouse by direct supply of underground air is higher. In this study the heat pump system using underground air as heat source was developed and heating performance of the system was analyzed. Heating COP of the system was 2.5~5.0 and rejecting heat into greenhouse and extracting heat from underground air in this heat pump system were 46.5~31.4 kW, 34.9~20.9 kW respectively.

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