• 제목/요약/키워드: AMCA

검색결과 16건 처리시간 0.031초

재사용이 가능한 MFB로부터 AMCA의 합성 공정 개발 (Practical Process Development of AMCA from Recyclable Source MFB)

  • 김종천;류영;김석찬
    • 공업화학
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    • 제27권5호
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    • pp.508-511
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    • 2016
  • 재활용이 가능한 자원인 MFB를 출발 물질로 하여 AMCA의 합성을 진행하였으며, AMBA로부터 AMCA로의 최적의 상업화 합성 조건을 찾고자 촉매, 수소 압력, 반응 온도, 반응 시간 같은 공정 변수를 조사하였다. 최적의 조건은 촉매는 [5% Pd/C : 5% Pt/C : 5% Rh/C (1 : 1 : 1)]의 복합 촉매를 반응 시간은 8 h, 반응 온도는 $130^{\circ}C$, 압력은 30 bar일 때(수율 90%, 순도 99.9%)임을 확인하였다.

뇌동맥류의 조기수술 전 재출혈 방지를 위한 항섬유소용해제 투여의 효과 (The Effect of Antifibrinolytic Therapy in Prevention of Rebleeding before Early Aneurysm Surgery)

  • 이창영;임만빈;이장철;손은익;김동원;김인홍
    • Journal of Korean Neurosurgical Society
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    • 제30권9호
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    • pp.1065-1071
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    • 2001
  • 파열된 뇌동맥류의 조기수술이 계획된 환자에서 수술전까지 단기간에 걸친 항섬유소용해제 투여의 효과를 알아보기 위해 뇌동맥류성 지주막하출혈 환자 137례에 대하여 60례를 AMCA 투여군으로, 77례를 비 투여군으로 분류하여 재출혈, 증상적 혈관연축, 뇌수두증의 발생빈도 및 전체적인 치료성적을 비교, 분석하였다. 재출혈의 발생빈도는 AMCA 비 투여군에 비해 투여군에서 통계학적으로 유의하게 낮게 나타났고 AMCA의 장기투여에서 증가를 보인 증상적 혈관연축과 뇌수두증의 발생빈도는 양군에서 유의한 차이를 보이지 않았으며 전체적인 치료성적은 AMCA 투여군에서 비 투여군에 비해 보다 양호한 결과를 보였다. 따라서 조기수술이 계획된 뇌동맥류성 지주막하출혈 환자에서 AMCA의 단기간 투여는 재출혈율을 감소시켜 전체적인 치료결과를 향상시키는데 도움이 될 것으로 생각된다.

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유동안정화 장치가 홴 테스터의 성능에 미치는 영향 (Effects of Flow Settling Means on the Performance of Fan Tester)

  • 최영석;김덕수;윤준용
    • 한국유체기계학회 논문집
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    • 제8권5호
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    • pp.29-34
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    • 2005
  • In this study, the effect of flow settling means on the performance of fan tester were numerically investigated by using a computational fluid dynamics (CFD). The airflow rate was calculated from the pressure differential across a flow nozzle in the measuring plane and the flow settling means were generally installed in the chamber of the fan tester to provide proper airflow patterns ahead of the measuring plane. The predicted nozzle differential pressures with uniform inlet velocities were compared with the values of the ANSI/AMCA 210-99 to verify the performance of the commercial CFD code CFX 5.6. The influence of flow settling means on the measurement of airflow rate in a fan tester were discussed with various porosities and inlet jet velocities. The results obtained show that the proper band of porosities exist to meet the AMCA standard in a specified inlet jet velocity.

유동안정화 장치가 홴 테스터의 성능에 미치는 영향 (Effects of Flow Settling Means on the Performance of Fan Tester)

  • 최영석;김덕수;윤준용
    • 한국유체기계학회 논문집
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    • 제9권4호
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    • pp.43-48
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    • 2006
  • In this study, the effect of flow settling means on the performance of fan tester were numerically investigated by using a computational fluid dynamics(CFD). The airflow rate was calculated from the pressure differential across a flow nozzle in the measuring plane and the flow settling means were generally installed in the chamber of the fan tester to provide proper airflow patterns ahead of the measuring plane. The predicted nozzle differential pressures with uniform inlet velocities were compared with the values of the ANSI/AMCA 210-99 to verify the performance of the commercial CFD code CFX 5.6. The influence of flow settling means on the measurement of airflow rate in a fan tester were discussed with various porosities and inlet jet velocities. The results obtained show that the proper band of porosities exist to meet the AMCA standard in a specified inlet jet velocity.

자동제어계측을 이용한 송풍기 성능시험 (Fan Performance Test with Automatic Control and Measurement)

  • 최영석;김진권
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
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    • pp.373-378
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    • 2003
  • In this paper, build up of fan performance tester in KITECH was introduced. The fan tester was set up based on AMCA standards 210-99, ANSI/ASHRAE 51-1999 with maximum flowrate within $1000\;m^{3}/min$. Both of inlet and outlet chamber setup with multiple nozzles described in AMCA 210 were established. The development of fully automatic control and measurement system are described. With this system, the accuracy of fan performance test can be maintained through the various flowrate and the uncertainty can be reduced.

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ANSI/AMCA 210 기준에 의한 대형 축류 송풍기의 성능시험 및 측정 불확도 평가 (An Estimation of Performance Test and Uncertainty of Measurement for a Large Axial-flow Fan Based on ANSI/AMCA 210 Standard)

  • 고희환;정철영;김경엽
    • 한국유체기계학회 논문집
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    • 제17권2호
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    • pp.24-29
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    • 2014
  • In general, a large-capacity axial flow fan is used for industrial processes or ventilation in a social overhead capital infrastructure. The main characteristics of the large axial-flow fan need a lot of electrical power consumption and operate 24 hours a day, 365 days a year. Since the large axial flow fan consumes several hundreds to thousands kW per hour, both manufacturer and consumer are struggling to select high efficiency products for saving energy and reducing operation cost. Therefore, the performance testing should be accurately conducted in experimental equipments. The performance estimation and uncertainty of measurement of the axial-flow fan gathered from the result from nozzle shaped testing equipments certified with ANSI/AMCA standard and duct shaped testing equipment under the same experimental condition. The experimental results from both facilities have maximum 17% differences in performance evaluation and uncertainty of measurement. As considering that the differences, it is doubt about the reliability of testing result. The test was repeated with the specific term during 12 months because it is important to fully reflect the real conditions and to decide the repeatability of data. The evaluation of duct type testing facilities was failed to get an uncertainty measure. Testing results were previously published. As a series of previous paper, axial fan (∅1690 mm) and duct type testing facilities were fabricated. The purpose of fabricating testing equipment was testing an uncertainty measurement under the controlled environments.

The Angiographic Feature and Clinical Implication of Accessory Middle Cerebral Artery

  • Kim, Myoung-Soo;Lee, Hyun-Koo
    • Journal of Korean Neurosurgical Society
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    • 제45권5호
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    • pp.289-292
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    • 2009
  • Objective : Although there are several descriptions of this vessel, there is no detailed angiographic study of the accessory middle cerebral artery (AMCA) in Korea. We describe the angiographic characteristics of the cortical territory and origin of AMCA and discuss the clinical significance of this anomaly. Methods : We searched for patients with AMCAs from a retrospective review of 1,250 conventional cerebral angiograms. We determined the origins, diameters and cortical territories of these AMCAs. Results : Fifteen patients (15 of 1250 = 1.2%) had 16 AMCAs (one patient had bilateral AMCAs). AMCAs originated from the distal A1 in eleven cases, middle A1 in two, proximal A1 in two, and proximal A2 in one case. All AMCAs followed a course parallel to the main middle cerebral artery (MCA). All but three of these arteries were smaller than the main MCA. Thirteen of the smaller diameter AMCAs had cortical distribution to the orbito-frontal and prefrontal, and precentral areas. Three AMCAs had diameter as large as the main MCA. These three supplied the orbito-frontal, prefrontal, precentral, central and anterior-parietal arteries. Conclusion : The AMCAs originated from A1 or A2. Most had smaller diameter than the main MCA. The AMCAs coursed along the horizontal portion of the MCA, but supplied the orbital surface, the anterior frontal lobe and sometimes wider cortical territory, including the precentral, central, anterior-parietal areas.

제연댐퍼 누설량 시험에 관한 연구 - 제연시스템의 성능위주설계를 위하여 - (A Study on Leaking amount Test of Control Damper - For a Performance Based Designed of Smoke Control System -)

  • 최규출;송윤석;차종호
    • 한국화재소방학회논문지
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    • 제23권3호
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    • pp.131-137
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    • 2009
  • 본 연구에서는 AMCA Standard 500-D-98과 관련하여 여러 시험의 조건 중 제연댐퍼의 누설량을 측정하고자 한다. 이에 본 연구의 결과로서 설계, 도면검토, 성능검사에 공학적 시험자료를 이용한 제연댐퍼의 누설량 성능곡선도 등을 적용하여 제연시스템의 올바른 설계법과 검사법을 정립하여 기술에 대한 이해와 성능이 확보되도록 한다. 또한 성능곡선도의 성능판단에 의한 댐퍼의 선정으로 댐퍼의 품질 개선을 유도하여 제연시스템의 성능을 향상시켜 신뢰성 있는 성능위주설계의 제연시스템을 구축하고자 한다. 제연댐퍼 누설량 시험을 한 결과 시험장치의 크기는 시험하는 제품의 규격, 성능에 따라 결정되므로 먼저 제품의 성능 등급을 설정하여 크기를 결정하여야 하며, 모든 시스템의 성능은 계측에 의하여 판단되므로 측정 값의 신뢰도 확보는 최우선 되어야 하며, 제연댐퍼의 시험방법에 따라 신뢰도를 부여할 수 있는 시험횟수와 시험해야 할 수량에 대하여 충분한 검토 결과에 따른 설정이 필요하다.

차량용 냉각 팬과 엔진 블럭의 간격 변화에 따른 성능 특성 연구 (Experimental Study on Performance Characteristics with Various Spacings between Automobile Cooling Fan and Engine Block)

  • 유병민;유기완;장재경;이강덕;홍성규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2009년도 추계학술대회 논문집
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    • pp.143-149
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    • 2009
  • Recently, according to the tendency to the more comfortable automobile, the improvement of performance of the cooling fan is required. The performance of cooling fan is affected by many peripheral parts, such as radiator, condenser, engine block and etc. Therefore, it is important to consider the effect of peripheral components on the fan performance in design and analysis stages. In this paper, the performance of automobile cooling fan is investigated experimentally by using the large capacity fan tester based on the ASHRAE and the AMCA standards. In particular, the various spacing between cooling fan and engine block are considered to obtain the effect of engine block. An empirical relation between the fan flow rate and the spacing was proposed.

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