• Korean Journal of Microbiology
• /
• v.12 no.3
• /
• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2004.05a
• /
• 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.

• Journal of the Korean Society for Railway
• /
• v.13 no.5
• /
• pp.476-480
• /
• 2010

In the corrugated steel panels used for railway vehicles, sound insulation performance is significantly deteriorated by local resonance effect. In this study, as a countermeasure, polyurethane foam is filled in the corrugated steel panel and glass wool layer is inserted in the layered floor panel, and then improvement effect of the sound insulation performance is experimentally estimated. Based on ASTM E2249-02, intensity transmission loss is measured and estimated on the corrugated panel and floor structure. The aim of the study is to identify how the foam filling and inserting glass wool layer improve the sound insulation performance of the train body structure in aspect of the weight increment.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• 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.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• 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.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2012.04a
• /
• 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.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2011.11a
• /
• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.10a
• /
• 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.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2009.09a
• /
• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• 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.