• 한국수산과학회지
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• 제41권6호
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• pp.440-445
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• 2008

Ciprofloxacin is the most commonly used fluoroquinolones for treating bacterial disease in olive flounder (Paralichthys olivaceus) farming, but its withdrawal time for industrial-scale farming has not been established. The depletion of ciprofloxacin was investigated in the olive flounder under field conditions. Fish were kept in an inland fish farm and fed a commercial diet containing 5 mg/kg of ciprofloxacin for 13 days. Seven fishes per sampling time were examined during and after the treatment. Ciprofloxacin and its major metabolite, enrofloxacin, were analyzed using HPLC with a fluorescence detector. The concentrations of ciprofloxacin and enrofloxacin in muscle increased during the medication period, and then decreased rapidly. The ciprofloxacin and enrofloxacin concentration in the olive flounder peaked on days 11 and 13, respectively, with maximum concentrations in muscle of 0.58 and 0.73 mg/kg. Residual ciprofloxacin and enrofloxacin were eliminated rapidly; 6 days after treatment, the respective levels in muscle were 0.04 and 0.10 mg/kg and neither was detected 15 days post treatment. The level of ciprofloxacin accumulation at the beginning of oral administration was variable according to the farming conditions, but the overall exhaustion time was similar. In conclusion, an adequate withdrawal period for enrofloxacin is 15 days in the case of oral ciprofloxacin administration.

• 한국양식학회지
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• 제12권3호
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• pp.175-183
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• 1999

We have shown previously that the sequence of olive flounder (Paralichthys olivaceus) hsp70-related cDAN has a high similarity with those of cognate hsc70 of other species (Kim et al., 1999; J. Aquaculture, 12:91-100). In order to investigate whether this gene encodes the congate hsc70, we examined the expression of this gene in normal and heat-shocked conditions. By in vitro translation, this gene encoded a 70 kD protein which was constitutively experessed and was not induced by heat shock. This translated protein was recognized by anti-hsp/hsc70 antibody. Tests of heat-inducibility showed that this gene was constitutively expressed in normal conditions and its expression was not increased after heat shock. The expression levels of this gene were high in stomach, gill, intestine, kidney and brain, moderate in liver, and comparatively low in overy and heart. Furthermore, Northern blot analysis of transcript expression showed that the corresponding mRNA were detected throughout embryonic development in the absence of any heat shock. These results provided evidence that olive flounder hsp70-related cDNA encoded to cognate member of hsp70 family, hsc70.

• 한국수산과학회지
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• 제22권5호
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• pp.228-232
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• 1989

분말가쓰오부시를 물로 우릴 때 최적추출조건을 구명하고 아울러 omission test 및 관능검사를 통해서 각 정미성분의 맛에 대한 기여도를 검토하였다. 분말가쓰오부시의 최적추출조건은 $100^{\circ}C$ 1분간 끓이는 고온단시간 추출이 유효하였으며, 특히 저온장시간 추출에 비해 중$\cdot$고비점 휘발성성분이 발생하여 특유의 풍미를 생성시켰고, 또한 국물의 투명감 면에서도 우수하였다. 상기의 조건하에서 추출한 분말가쓰오부시의 국물은 핵산관련물질이 93.6mg/100ml으로 함량이 가장 많았고 다음이 유리아미노산류로 41.3mg/100ml, 유기산류 39.3mg/100ml이었다. 핵산관련물질 중에서는 IMP, inosine, AMP가 주체이었으며, histidine, anserine, taurine, carnosine 및 lactic acid가 유리아미노산 및 유기산의 주성분이었다. Omission test 및 관능검사 결과 분말가쓰오부시 국물맛에 대한 각 정미성분의 기여도는 핵산관련물질이 가장 컸고, 다음이 유리아미노산, 유기산 순이었으나 어느 한 성분의 절대적인 기여보다는 각 성분이 서로 조화를 이루고 있었다.

• 한국수산과학회지
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• 제16권2호
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• pp.133-139
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• 1983

정어리를 효율적으로 이용하기 위한 하나의 방안으로서, 식염농도가 낮은 정어리젓의 가공조건을 설정하고자 젖산, sorbitol, glycerin, 에틸알코올을 첨가하여 숙성 중의 pH, 휘발성염기질소 등의 변화를 관능검사와 더불어 실험한 결과 정어리젓의 최적가공조건은 정어리육에 대하여 젓산 $0.5\%$, sorbitol $6\%$, 에틸알코올 $6\%$를 젓담금할 때 첨가하여 60일간 숙성시키는 것이라는 결론을 얻었다.

• Fisheries and Aquatic Sciences
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• 제25권5호
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• pp.264-275
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• 2022

A non-destructive environmental DNA protocol for the genetic analysis of sea cucumber (Apostichopus japonicus) resources DNA was established. Among the several commercial DNA extraction kits, the DNeasy^® Plant Mini Kit was selected as the best choice to obtain the high-quality genomic DNAs from the mucous sea cucumber. As the temperature and incubation time increased, the amount of extracted environmental DNA was also large, but it was judged that the increased amount did not affect as much as 2-3 times. Therefore, these conditions were not considered to be the main factors to consider in actual environmental DNA extraction. However, the amount of seawater relative to the size of the sample was judged as a major consideration, and a sufficient amount of environmental DNA for analysis was secured when stored within 1 min while stirring the volume of seawater corresponding to the total sea cucumber weight (g). In securing the environmental DNA of sea cucumbers, the mortality rate of sea cucumbers in all experiments was 0, and it was judged that the effects of sea cucumbers were not significant through this treatment. Through the results of this study, sea cucumber DNA research, which has been conducted in a destructive method, can be conducted non-destructively through environmental DNA analysis. Through this study, we have secured a standard protocol that can successfully extract the sea cucumber DNA through environmental DNA. It is not only excellent in terms of time and cost of traditional DNA analysis method currently used, but it is completely non-destructive in the ecosystem of the survey area. It is believed that the system can be transformed in a way that does not affect it. However, it is thought that various standard protocols should be established considering the characteristics of each type.

• 한국수산과학회지
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• 제56권6호
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• pp.870-877
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• 2023

The purpose of this study was to assess the efficiency of nitrification based on ammonia loading rates and hydraulic air-loading rates in a moving bed bioreactor (MBBR) under seawater conditions. The goal was to provide foundational data for the design of these bio reactors. At an ammonia loading rate of 0.2 g TAN·m^-2 surface area·day^-1, the influent TAN concentration was determined to be 1.76±0.33 mg·L^-1, which is below the safe concentration for fish survival (2 mg·L^-1). Considering operational aspects, the optimal ammonia-loading rate was derived. Subsequently, experimental results for nitrification efficiency at the optimal ammonia-loading rate revealed that the optimum hydraulic air-loading rate was 1.8 L·air·m^-2 surface area·min^-1. This condition resulted in the lowest concentrations of TAN and NO₂-N in the influent water, thus establishing the optimal hydraulic air-loading rate. A regression equation was derived for the ammonia-removal rate (Y) based on the ammonia-loading rate (x) and expressed as a 0.5-order equation (Y=ax^0.5+b). Specifically, for TAN concentrations of 0-6 mg·L-1, the regression equation Y=0.1683x^0.5-0.13628, was established.

• 수산경영론집
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• 제43권2호
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• pp.15-26
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• 2012

This study aimed to examine the establishment of the fish-paste processing industrial cluster in Busan. In order to successfully promote the fish-paste processing industrial cluster in Busan, first of all, it is required to implement various fish-paste processing related infra-structures and foundations. In addition to this, the agreements among fish-paste processing related organizations and businesses are inevitable to secure plans of inter-working with fisheries policies, to make efficient conditions for the stable supply of raw materials, and to pursue various supports from central and local governments for a viable development of fish-paste processing business companies in Busan.

• 한국수산과학회지
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• 제20권5호
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• pp.457-462
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• 1987

Stochastic stability criterias for ocean wave analysis add simulation are studied using the data simulated by the linear superposition method. To clarify the criterias, the effects of the simulation parameters on the variance of stochastic properties of ocean waves are investigated, and the stable conditions of the parameters are estimated through the comparative study on the stochastic properties of simulated waves and well-known ocean waves. The simulation parameters considered are high frequency cut-off, data length, and number and phase angle of component waves. Statistical characteristics analysed are wave height, period and steepness, and the formation of groups of higher waves, resonance periods, steeper higher waves and extreme run-length of the run.

• 수산해양기술연구
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• 제22권1호
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• pp.49-57
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• 1986

The vibrations problem of thin orthotropic skew plates of linearly varying thickness is analyzed using the small deflection theory of plates. Using dimensionless oblique coordinates, the deflection surface can be expressed as a polyonmial series satisfying the boundary conditions. For orthotropic plates which is clamped on all the four edges, numerical results for the first two natural frequencies are presented for various combinations of aspect ratio, skew angle and taper parameter. The properties of material used are one directional glass fibre reinforced plastic GFRP. The results obtained may be summarised as follows: 1. In case of the first mode vibration of plates with increase in the skew angle, the natural frequencies of plates decrease. 2. As the aspect ratio decrease, the natural frequencies of plates decrease. 3. For the identical skew angle, natural frequencies of plates increase with the taper parameter of thickness.

• 수산해양기술연구
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• 제52권2호
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• pp.79-87
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• 2016

Mobile fish-cage was developed assuming a cage net with an enclosed area, which and estimated the hydrodynamic characteristics of the cage through the model experiment. Flux-shielding plates, installed in the bow were compared with the resistance test carried out by making a hole, bilge keel and stud, and basic block flow rate consisting of the results to a flat surface plate. The experimental results confirmed the improved resistance performance effect of 3~6% in the bilge keel and the stud form. To assess the stability of the fish-cage, evaluation of the stability in accordance with the stability criteria for determining the floating docks had confirmed that it satisfied the static stability performance under operating conditions at sea.