• Title/Summary/Keyword: 환기기구

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Evaluation of Ventilation Systems in an Enclosed Nursery Pig House (무창자돈사의 환기시스템 정립 및 환기효율 평가)

  • Song, J.I.;Choi, H.L.
    • Journal of Animal Science and Technology
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    • v.44 no.1
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    • pp.123-134
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    • 2002
  • An experiment was conducted to establish the most suitable ventilation system for the enclosed nursery pig house in Korea, comparing four different ventilation systems ; i) air enters through perforated ceiling and exhausts through chimney (NA), ii) air enters through perforated ceiling and exhausts through side walls (NB), iii) air enters through perforated ducts and exhausts through side walls (NC) and iv) air enters through perforated ducts and exhausts through chimney(ND). The experiment was carried out during winter and summer separately. The experimental pigs were weaned at fourteen days old in winter (December-February) and at twenty one days old in summer (June-August). The main results of the experiment are as follows : A preliminary experiment showed that in the NC system during summer, air can reach all the pig rooms in the house and the air flow rates of the upper, middle (1.2 m height of the room) and low (at the height of pig stature) parts of the room were measured at 7.0-8.08, over 0.5 and over 0.2 m/s, respectively, which flow rates were much higher(p$<$0.05) than those in other system. At the minimum ventilation efficiency during winter, air flow rates of upper, middle and low parts of the room equipped with the NC system were detected at over 1, less than 0.5 and around 0.07 m/s, respectively. It is concluded that the separated ventilation system air-entering through ducts is the most suitable for the ventilation system of the enclosed nursery pig house and the exhausting system through side walls is more efficient for ventilation than the system through roof. Furthermore, to sustain proper temperature and reduce energy waste as well as heat consumption, a future research should be carried out to develop the environmental control system in relation to developing a heat regulator.

1,000만 서울시민의 발, 지하철이 밝아졌다!고효율 조명기기와 절전형 인버터 설치 ESCO사업 실시

  • 에너지절약전문기업협회
    • The Magazine for Energy Service Companies
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    • s.13
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    • pp.22-25
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    • 2001
  • 지하철이 ESCO사업을 통해 한층 쾌적하고 밝은 시설로 거듭났다. 서울지하철공사가 1, 2, 3, 4호선 115개 역사 가운데 74개역의 조명과 전동기 제어반을 고효율기기와 인버터제어방식으로 개체한 것. 지난해 12월부터 7월까지 약8개월에 걸쳐 $1\~4$호선의 안정기, 형광램프, 반사갓, 터널등기구를 에너지절약형 조명설비로 바꾸고 일반 On/Off제어방식이던 전동기 환기제어반을 절전형 인버터제어기로 교체했다. 지하철공사는 총141억2천9백만원이 투자된 이번 사업으로 인해 연간 약40억원에 해당하는 50,348Mwh의 전력소모를 줄일 수 있게 됐다.

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Studies on the Prevention of Excessive Drying Leaves during Burley Tobacco Curing III. Effect of the Ventilating Conditions on the Occurrence of Excessive Curing Leaves (버어리종 건조시 급건엽발생방지에 관한 연구 III. 환기조건이 급건엽발생에 미치는 영향)

  • 배성국
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.32 no.2
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    • pp.130-136
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    • 1987
  • The studies were carried out to investigate the occurrence of excessive dried leaves during burley tobacco curing. Six different periods of ventilation during the entire stage of curing were applied. And also 3 different heights of rolling up polyethlene film for side ventilation of the curing house combined with 4 different spaces between garlands were applied from after yellowing. The high air temperature and low relative humidity from end of yellowing to end of browning stage were the most critical to occur excessive dried \eaves. As side ventilation was continued for the entire stage of curing, air temperature in curing house was lower and occurrence of excessive dried leaves were remarkably decreased. The air temperature was not affected on hanging spaces, but relative humidity that resulted significantly in decreasing of the excessive dried leaves was increased by narrowing of hanging spaces. As excessive dried leaves were increased, its price per kg was lower, its physical properties was worse and its total nitrogen and total suger were higher than those of normal cured leaves.

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BUC Design and Fabrication for Flyaway Satellite Terminal (운반형 위성단말 고출력 상향 주파수변환기 설계 및 제작)

  • Kim, Joo-Yeon;Shin, Kwan-Ho
    • Journal of IKEEE
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    • v.24 no.1
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    • pp.72-80
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    • 2020
  • This paper describes the design and fabrication of a BUC(Block Up-converter) which is a component of a FST (Flyaway Satellite Terminal), one of the ET(Earth Terminal) of the military satellite. BUC is physically composed of an up-converter module, a high power amplifier module, a receive band suppression filter, a housing, and a cable assembly. It was designed using simulator AWR to satisfy the electrical characteristics of BUC's such as maximum output power, gain, unwanted signal, and intermodulation. The maximum output power and gain characteristics were measured at 43.4dBm and 51.8dB, respectively. The unwanted wave and intermodulation characteristics were -73.5dBc and -31.9dBc, respectively. Of the electrical requirements of Table 1, not only the above four but also all of the items were confirmed to be satisfied.

A Study on the Effective Fire and Smoke Control in Road-Tunnel with Semi-Transverse Ventilation (도로터널 화재시 대배기구 환기방식에서의 배연 연구)

  • Jeon, Yong-Han;Han, Sang-Cheol;Yoo, Oh-Ji;Kim, Nam-Jin;Seo, Tae-Boem;Kim, Jong-Yoon
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.1244-1250
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    • 2009
  • In this study it is intended to review the moving characteristics of smoke by performing visualization for the calculation of the optimal smoke exhaust air volume in case a fire occurs in tunnels where transverse ventilation is applied, and to obtain basic data necessary for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions under various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173\;m^3/s$, $236\;m^3/s$ for the distance of the smoke moving which can limit the distance to 250m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.

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LNB Design and Fabrication for Flyaway Satellite Terminal (운반형 위성단말 저잡음 하향 주파수변환기 설계 및 제작)

  • Kim, Joo-Yeon;Shin, Kwan-Ho
    • Journal of IKEEE
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    • v.24 no.1
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    • pp.81-89
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    • 2020
  • This paper describes the design and fabrication of a LNB(Low Noise Block downd-converter) which is a component of a FST(Flyaway Satellite Terminal), one of the ET(Earth Terminal) of the military satellite. LNB is physically composed of an down-converter module, a low noise amplifier module, a transmit band suppression filter, a isolator, a housing, and a cable assembly. It was designed using simulator (AWR) to satisfy the electrical characteristics of LNB's such as gain, noise figure and unwanted signal. The gain and noise figure characteristics were measured at 61.4dBm and 1.37dB, respectively. The unwanted wave was measured at -66.79dBc. Of the electrical requirements of Table 1, not only the above three but also all other items were confirmed to be satisfied.

Study on the Infection Control and Dental waste Disposal in Dental Clinic Located in Seoul City (서울시 치과의원의 진료실 감염관리 및 폐기물 처리 실태 조사연구)

  • Kang, Jae-Kyoung;Kim, Eun-Sook;Kim, Kyung-Mi
    • Journal of dental hygiene science
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    • v.2 no.2
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    • pp.105-113
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    • 2002
  • This study was aimed to investigate the practice on the infection control and dental waste disposal in dental clinic. The data used in this study had been collected in 100 dental clinics located in Seoul city from August to October, 2001. It was shown that examination instruments, oral surgery instruments, and periodontal instruments were almost sterilization in dental clinic. It was high in the recognition of individual protection but it was low in the degree of practice. Therefore, the practice in infection control is very important to dental team for safety of patients and operators.

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Experimental and Numerical Studies on Heat/Smoke Behavior due to a Fire on Underground Subway Platform (I) - Experimental Approach - (지하철 역사 승강장 화재발생시 열/연기 거동 분석을 위한 실험 및 수치 연구(I) - 실험적 접근 -)

  • Park, Won-Hee;Kim, Dong-Hyeon;Chang, Hee-Chul;Kim, Tae-Kuk
    • Fire Science and Engineering
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    • v.20 no.3 s.63
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    • pp.9-14
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    • 2006
  • In this study boundary velocity which is one of the important boundary conditions for numerical simulation for subway station on fire are experimentally obtained. The tests were conducted according to its operating mode of the ventilation systems in the platform: smoke extraction ventilation mode in occurrence of fire and normal ventilation mode for air conditioning. Velocities are measured at various points on the platform. To examine smoke extraction and air supply capacity in the platform level, air velocities were checked on opening vents. Numerical analysis under normal ventilation mode without fire is conducted by using measured boundary conditions, and the numerical results are compared with the measured velocities on the platform.

A research on the actual condition fire dangerousness for electric installation of stables (축사 전기설비 화재위험성 실태조사)

  • Lee, Young-Soo;Kim, Myeong-Soo;Kim, Man-Keon;Kim, Hyeog-Soo
    • Journal of Korean Institute of Fire Investigation
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    • v.9 no.1
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    • pp.65-77
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    • 2006
  • There is not high level to fire number in stables, but if it were fire, there would be happened many property damage in a national or personal. We grasp safety awareness of a safety supervisor enforcing question survey of electric installation for national stables, and investigate use the actual condition of electric installment with a heating apparatus, a ventilating system, a distributing board, a wiring apparatus etc high fire dangerousness among electric installment using a stables I hope to make use of data to protect a electric fire submitted thesis.

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Portal Placement for Thoracoscopic Right Middle Lung Lobectomy with One-Lung Ventilation in Beagle Dogs (비글견에서 편측성 분리폐 환기를 이용한 흉강경 우중폐엽 절제술을 위한 포트 위치)

  • Park, Ji Young;Lee, Hae-Beom;Jeong, Seong Mok
    • Journal of Veterinary Clinics
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    • v.32 no.1
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    • pp.9-15
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    • 2015
  • Purpose of this study is to determine the reasonable portal approach for thoracoscopic right middle lung lobectomy in small sized dogs under 10 kg. Ten healthy beagle dogs weighing $8.67{\pm}0.49kg$ were included. Under general anesthesia, one-lung ventilation (1LV) was achieved using endobronchial blocker with guidance of fiber-optic bronchoscope. Two portal approaches were used; 8-6-10 intercostal space (ICS) and 8-6-5 ICS approach. Thoracoscopic right middle lung lobectomy was performed using endoscopic linear self-cutting stapler and specimen retrieval bag. Each approach was evaluated by scoring 0; bad, 1; endurable, 2; good, 3; excellent in following five category, 1) visualization, 2) triangulation; instrumental sword fighting in the thoracic cavity, 3) approach to hilar pedicle; application of stapler, 4) any obstacles in applicating Lap Bag, and 5) the operator's convenience. Favorable working space was secured by 1LV and thoracoscopic right middle lung lobectomy was successfully completed in all dogs. There was no need to change the portal location and iatrogenic complication. Most of scores were good to excellent in both approaches. Consequently, both approaches are feasible methods for thoracoscopic right middle lung lobectomy with one lung ventilation using endoscopic linear self-cutting stapler in dogs weighing less than 10 kg.