• Title/Summary/Keyword: 성구

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Analysis of Wave Transformation and Velocity Fields Including Wave Breaking due to the Permeable Submerged Breakwaters (수중투과성구조물에 의한 쇄파를 수반한 파랑변형 및 유속장 해석)

  • 김도삼;이광호;김정수
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.2
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    • pp.171-181
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    • 2002

  • Among various numerical methods of wave transformations including wave breaking by structure, models using VOF(Volume Of Fluid) method to trace free surface are getting into the spotlight recently. In order to analyze wave transformations and velocity of the wave fields due to the permeable submerged breakwater(PSB), This study applied VOF method to the two-dimensional wave channel installed line-source to generate waves and added dissipation zone to offer a non-reflective boundary. Hydraulic experiments was performed to obtain the application of two-dimensional numerical wave channel. The results of numerical experiments using the two-dimensional wave channel agree well with the experimental data. It was shown that vortices are formed behind the PSB, and in case of the 2-rowed PSB they also are occurred in between PSBs, strongly non-linear waves are developed on the crown of the PSB, and the direction of velocities in porous media is determined by the shape of free surface.

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Studies on the Processing of Powdered Katsuobushi and Its Flavor Constituents 3. Volatile Flavor Components of Powdered Katsuobushi (분말가쓰오부시의 제조 및 풍미성분에 관한 연구 3. 분말가쓰오부시의 향기성분)

  • OH Kwang-Soo;LEE Eung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.22 no.4
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    • pp.169-176
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    • 1989

  • Volatile flavor components in powdered Katsuobushi were simultaneous trapped by steam distillation-extraction method, and these were fractionated into the neutral, the phenolic, the acidic and the basic fraction. Volatile flavor components in these fraction were analyzed by the high-resolution GC and GC-MS equipped with a fused silica capillary column. The whole steam volatile concentrate consisted of $48\%$ neutral fraction(NF), $35\%$ phenolic fraction(PF), $12\%$ acidic fraction(AF) and $5\%$ basic fraction(BF). Thirty components such as 8 hydrocarbons, 8 aldehydes, 6 furans, 5 alcohols and 3 ketones were identified from NF. And sixteen components such as phenol, guaiacol, dimethoxy phenol, eugenol in PF, twelve components such as propionic, butanoic, isopentanoic, n-hexanoic, heptanoic, octanoic acid in AF, ten components such as 2,6-dimethylpyrazine, 2-nethylpyridine, 2,4-dimethylthiaBole in BF were identified. NF and PF gave a much higher yield than others and were assumed to be indispensable for the reproduction of aroma of powdered Katsuobushi. It was also identified eight components of volatile carbonyl compounds such as ethanal, propanal, butanal, pentanal by 2,4-DNPH method.

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