A centrifugal cyclone dust collecting apparatus includes a hydro cyclone dust collecting apparatus for separating solid or liquid using liquid or suspension as a medium. In this study, the formation mechanism and improvement of air core and inner air layer were confirmed through Particle Image Velocimetry. These results showed that the modified experimental model was designed in the conventional method suitable for the separation of juvenile fish and eggs. The inlet speed of the multi-stage hydrocyclone dust collector, which can increase the inlet velocity and minimize floatage in the turbulence chamber, was increased from 0.15 to 0.30 m/s. As a result, the air core was stably formed, the inner air layer was increased with increasing speed. In addition, the dust collecting efficiency of egg and juvenile fish was 97.8% on average, It can infer that this system confirmed the ability to efficiently collect particles of 40 μm or more.
We measured the target strength according to the swimming tilt angle and size change for Pacific herring at the frequency of 70 kHz as the basic database in order to estimate its abundance as well as density in the survey area using the hydroacoustical method. The number of the sample used in this study was 14 individuals, and its size distribution by fork length ranged between 20.3 and 29.8 cm and wet weight was measured between 187.6 and 269.9 g. The variation of TS according to the swimming angle (-30~30°) was measured between 10.3 and 18.8 dB in frequency range, the highest value was measured at head-down of Pacific herring in the tilt angle range between 5 and 9 deg. of its swimbladder. The relationship between TS–FL of herring was the same as TS = 20log10 (FL) – 66.79 when its swimming tilt angle in the daytime (3.8 ± 6.0°) and nighttime (-3.2 ± 13.6°), respectively.
This study was conducted to understand the relationships between fish and zooplankton of distribution in the coastal waters of the East Sea from May to August 2016 using hydroacoustic. To distinguish between fish and zooplankton, we used the time varied threshold (TVT) method at the frequency of 120 kHz. As a result, the mean nautical area scattering coefficient (NASC) of fish was highest at 913 m2/n.mile2 in June and lowest at 315 m2/n.mile2 in July. The mean NASC of zooplankton was highest at 247 m2/n.mile2 in May and lowest at 70 m2/n.mile2 in July. The mean NASC of fish and zooplankton showed a significant difference (P < 0.05) with high correlation (R2 = 0.84). In addition, there was no significant difference in the mean NASC of fishes and zooplankton by depth (t-test, person correction = -0.17, p > 0.05).
The purpose of this study was to examine the effect of different types of frying oil on the quality of yakgwa such as expansion rate, color, moisture content and rheological properties. Yakgwa fried with corn oil showed the highest expansion in width and length, and rice bran oil in height. With regard to the overall expansion rate, yakgwa fried with rice bran had the highest value. As for lightness and yellowness, yakgwa fried with soybean oil had the highest lightness (34.74), while yakgwa fried with grape seed oil had the lowest lightness (29.82). As for redness, however, no significant difference was found. Regarding fat content, yakgwa fried with rice bran oil showed the highest value with 18.91%, while yakgwa fried with corn oil and canola oil showed the lowest value. No difference was found in moisture content according to the type of frying oil. In relation to the acid value, yagkwa with soybean oil showed the lowest value of 0.24±0.66; as for peroxide value, yagkwa fried with rice bran oil showed the lowest value of 3.59±1.74 meq/kg. No difference was found in hardness, cohesiveness and resilience according to the type of frying oil. Yagkwa fried with corn oil and canola oil showed the lowest value in terms of adhesiveness and chewiness, respectively. The results of the sensory evaluation showed not significance difference in overall preference, but yakgwa fried with rice bran oil had the highest value of 5.93±1.87.
향신료로 널리 사용되는 후춧가루를 비가열 살균 방법 중 하나인 광펄스 살균 처리를 하는데 있어서 처리용기에 따른 사멸 효과를 살펴보았다. 실험에 사용된 처리용기의 형태는 정치형, 회전 원통형, recycling fluidized bed형의 3가지 처리용기를 사용하였다. 전압1000 V, 펄스수 5 pps, 시료와의 거리 4 cm의 조건에서 10분간 처리하였을 경우 정치형 처리용기의 경우에는 흑후추 80%, 백후추는 84%의 감소효과를 나타내었으며, 정치형 처리용기 내부에 거울을 설치하였을 경우에는 같은 처리조건에서 흑후추는 86%, 백후추는 85%의 감소효과를 보였다. 회전 원통형 처리용기에서는 전압 1000 V, 8 pps, 시료와의 거리 4 cm에서 10분간 처리하였을 경우 일반세균은 흑후추 75%, 백후추 79%의 감소효과를 나타내었고, B. cereus는 흑후추 74%, 백후추 76%의 감소효과를 나타내었다. Recycling fluidized bed형 처리용기를 사용하였을 경우에는 흑후추는 일반세균 71%, B. cereus 60%, 백후추는 일반세균 73%, B. cereus 52%의 감소효과를 보였다. 모든 실험군에서 광펄스 처리 후 후추의 수분함량은 처리시간이 길어질수록 감소하는 경향을 보였으며, 색도에 있어서는 흑후추의 경우 광펄스 처리 후 명도와 적색도에서 유의적인 차이를 나타냈으며, 황색도는 차이를 보이지 않았다. 후추의 지표물질인 piperin은 흑후추의 경우 증가하는 경향을 보인 반면에 백후추의 경우에는 감소하는 경향을 보였으나 유의적인 차이를 보이지는 않았다.