• Title/Summary/Keyword: Tightness

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신축 공동주택에서 감압법을 이용한 기밀성능 실측 연구 (Field Measurement of Infiltration in New Apartments using De-pressurization Method)

  • 윤재옥
    • KIEAE Journal
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    • 제13권3호
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    • pp.27-32
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    • 2013
  • Infiltration is air flow that occurs through cracks in buildings. According to level and kind of infiltration, the cooling load and heating load in buildings may increase. In this study I conducted field measurements to evaluate air tightness in 27 new apartment units. Field measurements for new apartments was the focus. For the de-pressurization method, the equipment utilized to gauge airtightness included KNS-5000C and KNS-4000 which were installed on the window in order to measure indoor air leakage. The results are summarized as follows. The average ACH50 of a $59m^2$ APT was 3.98, 3.82 for a $84m^2$ APT, and 2.73 for a $114m^2$ APT. The total average ACH50 of 27units was 3.51.

외부조건의 변화에 따른 섬유보강콘크리트의 내구성능 정가에 관한 연구 (A Study on the Evaluation of Durability of Fiber Reinforced Concrete According to the Change of External Conditions)

  • 김남욱
    • 한국안전학회지
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    • 제23권5호
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    • pp.97-104
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    • 2008
  • This study was intended to evaluate the permeable performance through a change of reinforcing materials, curing condition, durability evaluation and permeability test, and to select the reinforcing material which could reduce the durability and water tightness from it, as the study for considering how the change of the outside's environment factors that the concrete structure actually contacted with impacted the concrete's durability especially the permeability by referring to such the background of the study. Accordingly, it was judged that evaluating the permeability by considering the severe environment condition where the concrete structure was placed in was more reasonable than measuring the existing permeability coefficient conducted in the sound state for the permeability evaluation of actually-used concrete structure. In this study, it also could be known that the specimen of hybrid fiber reinforced concrete which mixed the long and short steel fiber was the most effective for water tightness enhancement in severe environmental conditions.

공동주택에서 기밀성능과 차음성능과의 상관성 연구 (A Study on the Correlation between Air-tightness and Sound Insulation in the Apartment Housing)

  • 박철용;홍구표;최지혜;이용대;최준석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 추계학술대회 논문집
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    • pp.296-297
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    • 2013
  • We have investigated correlation between airtightness measured by blower door and airborne sound insulation measured in the upper and lower units. We consist of two cases : all windows sealed(CASE 1) and not sealed(CASE 2). As a result, CASE 1 is tighter than CASE 2 in airtightness, but CASE 1 is lower than CASE 2 in sound level difference. This is because of big wind on measuring CASE 1. Thus we are going to measure them at another fields considering this factor. Finally we ought to find out the correlation between airtightness and sound insulation.

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차음성능과 기밀성능이 향상된 경량 간막이벽 개발 (A Development of Partition Wall for enhenced Sound Transmission Loss and Air Tightness)

  • 배상환;박진우;홍천화
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 II
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    • pp.855-860
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    • 2001
  • As being inconvenient to apply reinforced concrete structure to high-rise buildings. it is applied steel structured system. Therefore light-weight wall systems are applied as partition wall to reduce the self-load of the building. But. the required performances of a light-weight wall are not evaluated systematically. As a field survey result. partition walls of house-to-house and room-to-room were not showed their respected performances. so the dwellers are feel so worse the quality of the whole building. In steel-structured high-rise buildings especially. occupant's dissatisfaction concerned indoor noise was high because curtain wall systems having a high air-tight performance isolate the outdoor noise making masking effect. Also to suppress indoor air movement. stact effect must be concerned. Therefore wall systems which have high performances of sound insulation and air-tightness are required in high-rise buildings.

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GENERALIZED FRÉCHET-URYSOHN SPACES

  • Hong, Woo-Chorl
    • 대한수학회지
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    • 제44권2호
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    • pp.261-273
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    • 2007
  • In this paper, we introduce some new properties of a topological space which are respectively generalizations of $Fr\'{e}chet$-Urysohn property. We show that countably AP property is a sufficient condition for a space being countable tightness, sequential, weakly first countable and symmetrizable, to be ACP, $Fr\'{e}chet-Urysohn$, first countable and semimetrizable, respectively. We also prove that countable compactness is a sufficient condition for a countably AP space to be countably $Fr\'{e}chet-Urysohn$. We then show that a countably compact space satisfying one of the properties mentioned here is sequentially compact. And we show that a countably compact and countably AP space is maximal countably compact if and only if it is $Fr\'{e}chet-Urysohn$. We finally obtain a sufficient condition for the ACP closure operator $[{\cdot}]_{ACP}$ to be a Kuratowski topological closure operator and related results.

Tightness of the Transition State for the Reactions of Secondary Alkyl Arenesulfonates with Anilines in Acetonitrile

  • 오혁근;권영봉;정동수;이익춘
    • Bulletin of the Korean Chemical Society
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    • 제16권9호
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    • pp.827-831
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    • 1995
  • Kinetic studies on the reactions of five secondary acylic alkyl arenesulfonates with anilines are carried out in acetonitrile at 65.0 ℃. The magnitude of ρXZ determined (ρXZ=0.12-0.13) is slightly greater than that for the alicyclic series (ρXZ=0.11) under the same experimental condition. Ab initio MO results are found to support the slightly tighter transition state expected from the greater magnitude of ρXZ for the acyclic series. Despite the small variations, the magnitude of ρXZ and the theoretical transition state tightness remain relatively constant for the secondary carbon centers. Secondary kinetic isotope effects involving deuterated aniline nucleophiles show a successively smaller kH/kD(<1.0) value for a more sterically crowded reaction center carbon. This is in accord with the later transition state for bond-making predicted by the Bell-Evans-Polanyi principle for the more endothermic nucleophilic substitution reaction. Further support is provided by the results of the AM1 MO calculations on the reactions of secondary alkyl benzenesulfonates with chloride nucleophile.

간헐적공기압박장치의 전달압력 측정시스템 개발 (Development of a Measurement System of the Transferred Pressure from Intermittent Pneumatic Compression Device)

  • 이원희;서종현;김준;강승호;김국한;정승현;김광기;강현귀
    • 대한의용생체공학회:의공학회지
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    • 제37권1호
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    • pp.39-45
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    • 2016
  • A pressure measurement system was developed to verify magnitude and position of transferred pressure on the body surface during the intermittent pneumatic compression (IPC) which is one of the most well-known methods for the prevention of deep vein thrombosis (DVT). Eighty force sensing resistors (FSR) were arranged on a mannequin leg and a hardware controller sensed, digitized, and transferred pressure data every second while IPC was being applied. Finally, sensed pressure data were color coded and visualized on the 3D model with lab-developed software. The pressure data were also saved to files for further analysis. Using this measurement system, the changing pattern of pressure was measured on the mannequin leg by changing both chamber pressure and cuff tightness. As a result, net pressure transferred onto the body surface is dependent on chamber pressure and cuff tightness. Under the same chamber pressure, the tighter a cuff was worn, the wider compressed area was and the shorter compression cycle was. Also transferred pressure was proportional to both chamber pressure and cuff tightness.