• 제목/요약/키워드: Steel wool

검색결과 32건 처리시간 0.024초

염기성 세균 배양을 위한 Steel Wool법과 Gaspak법의 비교 (Comparative Studies of Steel Wool Method and Gaspak Method for the Culture of Anaerobic Bacteria)

  • 정윤섭
    • 미생물학회지
    • /
    • 제12권3호
    • /
    • pp.131-137
    • /
    • 1974
  • It is a well-known fact that an isolation of non-sporeforming anaerobes, considered normal flora in man ordinarily but causes serious infections sometimes, is a dificult procedure because of their great oxygen sensitivity. Among the many techniques employed in clinical laboratories, despite of its high expenses, the GasPak method has been most widely used because of its relative simplicity. On the other hand, the steel wool method has gained a good reputation recently. This technique makes it possible to treat individual plate so that any single specimen can be promptly cultured anaerobically. The procedure is quite simple and the expenses are negligible. In the present study it is to compare these two methods as to their efficiency of anaerobic cultivation using 13 VPI strains of non-sporeforming amaerobic bacteria. Among the 13 species the following 11, Bacteroides fragilis ss. fragilis, B. fragilis ss. thetaiotaomicron, propionibacterium acnes, Eubacterium limosum, E. lentum, peptococcus asaccharolyticus, Pc. prevotii, Pc. magnus, peptostreptococcus anaerobius, Ps. intermedius nad Veillonella parvula, grew well with the steel wool method whose colony numbers reaching 57 to 119% of those with GasPak method. The remaining two species, Fusobacterium nucleatum and F.necrophorum, did not grow well with the steel wool method showing the colony numbers were only 0.4% of those with GasPak method in the case of Fusobacterium nucleatum. In the case of Fusobacterium necrophorum, very few colonies developed even with a heavy inoculation. As to the size of colonies, there were no significant difference between these two methods.

  • PDF

뜬바닥 구조를 이용한 격실의 소음 및 진동저감 (Reduction of noise and vibration of cabin by using the floating floor)

  • 김현실;김봉기;차선일;김영수
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2004년도 춘계학술대회논문집
    • /
    • pp.300-303
    • /
    • 2004
  • In this paper, floor impact noise reduction in a cruise ship cabin by using floating floor is studied. A mock-up is built by using 61 steel plate, and two identical cabins are made where 25t panel is used to construct wall and ceiling inside the steel structure. Various floating floor systems are tested for which normalized impact noise is measured according to ISO 140-7 It is shown that effect of VL(Visco-elastic Layer) is negligible when it is used between deck and mineral wool, since most vibration absorption occurs in the wool. In addition, direction of the mineral wool fiber affects impact noise significantly.

  • PDF

흡음 및 댐핑재 의한 주름강판의 차음성능 개선효과 (Improvement Effect of the Sound Insulation Performance of the Corrugated Steel Panel by Sound Absorbing and Damping Materials)

  • 김석현;서태건;김정태
    • 한국철도학회논문집
    • /
    • 제13권5호
    • /
    • pp.476-480
    • /
    • 2010
  • 철도차량의 바닥재에 널리 사용되는 주름 강판은 국부공진 효과에 의하여 특정 주파수 대역에서의 차음성능이 심각하게 저하된다. 그 대책으로, 본 연구에서는 우레탄 폼재를 주름내부에 충진시키거나 유리면층을 바닥재에 적층시킨 후, 차음성능의 향상효과를 실험적으로 평가한다. 주름강판 및 바닥 적층재를 대상으로 ASTM E2249-02에 근거하여 인텐시티 투과손실을 측정하고 평가한다. 본 연구의 목적은 폼 충진이나 유리면 적층이 중량 증가 측면에서 열차 차체의 차음성능을 어느 정도 향상시키는가를 규명하는 데에 있다.

소형 이륜자동차의 머플러 배기압력 특성에 관한 실험적 연구 (Experimental Study on the Exhaust Pressure Charactieristics in the small motorcycle.)

  • 이중섭;최석천;배재영;정한식;정효민;서정세
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2004년도 추계학술대회
    • /
    • pp.678-683
    • /
    • 2004
  • In this study, a experiment has been developed for measuring the exhaust pressure of muffler at inlet and outlet. The main experimental parameters were a engine speed and sound absorbing material in the muffler. The muffler sound absorbing material tested a steel wool and glass wool. The exhaust pressure was measured with pressure sensor. The phase of exhaust pressure with high speed was moved according to increasing engine speed comparing with exhaust pressure with low speed. Also, the distribution of exhaust pressure at the model-1, 2 and 3 are similar with distribution of exhaust pressure at muffler inlet.

  • PDF

주름강판의 차음성능 향상 방안 (Improvement Strategy of the Sound Insulation Performance of a Corrugated Steel Panel)

  • 이현우;김석현;김정태;김재철
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2009년도 춘계학술대회 논문집
    • /
    • pp.1097-1102
    • /
    • 2009
  • In a railway vehicle, corrugated steel panel is widely used for the floor panel because of its high bending stiffness and light weight. However, this panel shows lower sound insulation performance than that of the plate with the same weight. Especially, in a particular frequency band, transmission loss (TL) rapidly decreases and it results in the deterioration of TL of the overall floor panel. This study identifies that the remarkable drop in TL is caused from the local resonance of the periodic corrugated structure. This study shows that the frequency band of the TL drop can be controlled by the proper design of the corrugated structure. In addition, improvement effect of TL by attaching foam and glass wool is estimated by experiment. The purpose of the study is to provide the practical information for the improvement of the sound insulation performance of the corrugated steel.

  • PDF

ISO 13784-1 RRT 결과의 정밀도 분석 (Precision analysis on the ISO 13784-1's Round Robin scenarios)

  • 박계원;정재군
    • 한국화재소방학회:학술대회논문집
    • /
    • 한국화재소방학회 2012년도 춘계학술발표회 초록집
    • /
    • pp.333-336
    • /
    • 2012
  • ISO 13784-1 sandwich panel tests were conducted by FILK, KICT in Korea, SP in Sweden and CSIRO in Australia. Sandwich panels composed of steel sheets, EPS and glass wool supplied by FILK were tested. Mainly heat release rate was compared and equlity of distribution also analyzed on the point of statistical view based on ISO.

  • PDF

ISO 13784-1 시험 방법에 의한 국제 상호비교 평가 분석 (Analysis on International Round Robin Test's Result by ISO 13784-1 Standard)

  • 박계원;정재군
    • 한국화재소방학회:학술대회논문집
    • /
    • 한국화재소방학회 2011년도 추계학술논문발표회 논문집
    • /
    • pp.201-204
    • /
    • 2011
  • ISO 13784-1 sandwich panel tests were conducted by FILK, KICT in Korea, SP in Sweden and CSIRO in Australia. Sandwich panels composed of steel sheets, EPS and glass wool supplied by FILK were tested. Mainly heat release rate was compared and equality of distribution also analyzed on the point of statistical view based on ISO.

  • PDF

틸팅 차량용 적층재의 차음성능 평가 (An Estimation of the Sound Insulation Performance of the Multi-layered Panel for a Tilting Train)

  • 서태건;임봉기;김석현;김재철
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2009년도 추계학술대회 논문집
    • /
    • pp.597-600
    • /
    • 2009
  • Sound transmission loss (TL) is experimently investigated on the multi-layered panel used for the floor of a tilting train. Measurement of the intensity transmission loss is performed according to ASTM E 2249-02. The floor structure consists of corrugated steel panel, glass wool, plywood and cover. On the corrugated steel panel, TL drop by local resonance is considered and the TL improvement effect by damping treatment is estimated. Total sound transmission loss of the entire floor structure is obtained and the contribution of each layer is examined.

  • PDF

대형 컨테이너선 건조를 위한 고능률 용접기술 (High Productive Welding Technologies for Large Container Ship)

  • 구연백;성희준;최기영;김경주
    • 대한조선학회 특별논문집
    • /
    • 대한조선학회 2009년도 특별논문집
    • /
    • pp.80-86
    • /
    • 2009
  • In order to improve productivity of large container ship construction, large heat input and/or high productive welding technologies are necessary. This can be achieved by the joint research and cooperation among steel maker, welding consumable company, welding equipment company and ship yards. Two electrodes SAW process is effective the plate butt welding and partial joint welding, while FGB welding process is for the connection of block to block joint. The higher strength and thicker steel is developed, the more reliable welding procedure such as two electrodes EGW including light weight welding equipment should be developed.

  • PDF

Wave 모델을 이용한 바닥충격음 해석 (An Analysis of Floor Impact Noise by using Wave Model)

  • 김현실;김재승;강현주;김봉기;김상렬
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2006년도 춘계학술대회논문집
    • /
    • pp.1417-1420
    • /
    • 2006
  • In this paper, floor impact is studied by using 1-D wave model and predicted insertion loss is compared to the measurements done in the mock-up. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t or 50t panel is used to construct wall and ceiling inside the steel structure. Various floating floor structures are studied, in which mineral wool thickness, height, and stiffness changes are investigated. It is shown that the wave model and measurements are in good agreements in general, although there occur significant discrepancies in the low frequency range below 200 Hz.

  • PDF