• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.761-766
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• 2006

This paper describes a study on the performance of steam ejector by variation of steam pressure. Water temperature is especially important for good qualify of fish in an inland aquafam. In summer season, the water temperature increases above $25^{\circ}C$, but for good quality breeding or fish is the maintenance of optimum aquafam temperature by about $20^{\circ}C$. Therefore it is needed to drop the water temperature to provide suitable conditions of fish growth. There are many kinds of cooling system, in this study using steam ejector. After cooling the water in vacuum tank with the steam ejector then circulate this water to inland aquafam. In this way to minimizes fish stress that it is caused by water temperature. The objective of research confirms the difference of the case which there is no water in the vacuum tank and has water in the vacuum tank. The purpose of this paper is to examine the effects on the performance of steam ejector by variation of steam pressure.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.4
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• pp.418-429
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• 1992

Recently, many researchers make a great effort to develop high efficient marine diesel engines using low grade heavy oil, and also study substitution fuel oil for engines and boilers. In case of Fisheries Vessels, we need to know that fish oil can be substituted for fuel oil. Therefore, it is studied that evaporation, ignition and combustion phenomena of the single droplet of fish oils (i.e., Sardine fish oil, File fish oil and Alaska pollac oil) on heated plane surface to evaluate appropriateness as substitution oil. Methanol and light oil are tested simultaneously to help the evaluation on these Fish oils. The results are summarized as follows: 1. The type of evaporation and combustion is spherical evaporation in case of methanol and light oil. And fish oil blended with light oil was finished after spherical evaporation happen when high temperature. 2. Ignition of Pure fish oil was shorter than that of fish oil blended with light oil. 3. Heat transferred to droplet could make qualitative comparison by contact diameter of droplet with hot surface as time changes. Life time of droplet according to the change of heated surface temperature was greatly influenced by droplet contact condition on the heated surface. 4. As far as combustion phenomena was concerned, apparent diameter of the fish oil droplet increased after ignition and decreased suddenly by internal boiling of droplet. 5. Three fish oils had similar phenomena on the evaporation, ignition and combustion. 6. Evaporation and combustion feature of fish oil could not be shown by coefficient of evaporation velocity of droplet and coefficient of combustion velocity of droplet.

• Journal of Nutrition and Health
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• v.17 no.4
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• pp.297-304
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• 1984

The effect of dietary fish oil ( mackerel oil : MO, eel oil : EO) on energy utilization in rats was studied with measurements of various tissue lipoprotein lipase( LPL ) and live and heart mitochondrial respiration. Fatty acid composition of mitrochondrial inner membrane matrix was also investigated. Dietary fat level was 10%( w/w) and reference groups were fed soybean oil (SO), repeseed oil ( RO) and beef tallow( BT ). Activity of LPL was about 60% higher in post-heparin plasma and 2 to 3 times higher in adipose tissue of BT group than fish oil or vegetable oil group. But there was no significant difference between fish oil and vegetable oil groups. Inclusion of EO above 2% (w/w) in dietary fat with fille oil of BT, markedly reduced both post -heparin plasma and adipose tissue LPL. Effects of MO and EO were not different in adipose tissue LPL, but EO was more effective than MO, in reducing post -heparin plasma LPL when mixed fat with varying amount of fish oil was used. Hepatic mitochondria isolated from fish oil-fed group showed the lowest rate of respiration but had P/O ratio comparable to SO and BT groups. On the other hand, cardiac mitochondria of fish oil group showed no difference in all the mitochondrial respiration parameters observed RO group had lowest P/O ratio both in hepatic and cardiac mitochondria. Fatty acid compositions of mitochondrial lipid differ between SO, RO, BT and MO groups, notably in the content of $C_{22:1}$ fatty acid.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.375-376
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• 2001

Many studies have been made on antimicrobial activity of Sawa-wasabi (Wasabia japonica). It has been reported that the essential oil of Sawa-wasabi has a particularly strong antimicrobial effect against Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa and fish pathogenic bacteria such as Edwardtarda siella and Vibrio hollisae (Nishida, 1958; Inoue et al. 1983;).(omitted)

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.305-312
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• 1995

A species of metacercariae recovered from the fresh-water fish, collected from Kaumji (Pond), Kaechonji (Pond) and Ssanggyechon (River), Uisong-gun, Kyongsangbuk-do, Korea, was identified as Clinostomum compzcnatum by morphological observation and experimental infection to chicks. The excysted metacercariae, tongue-shaped and progenetic, were 3.28-4.27 mm in length and 0.94-1.46 mm in width. The adult flukes recovered from the chicks four days after infection were 4.20-4.86 mm long and 1.14-1.49 mm wide. Twelve species of the fresh-water fish were found to be infected with the metacercariae. The infection rate ranged from 1.6% (Zacco temminkii) to 88.9% (Acheilognathus rhombec and Microphwsogobio voluensis) . The intensity was highest in Cnrqssius curatus (13.0/fish infected) and the abundance (relative densityl was highest in A. rhombea (7.8/fish examined). This survey demonstrated for the first time the source of human infection by C. complnnntum in Korea.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.4
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• pp.315-328
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• 2016

Techniques for determinating hydrodynamic derivatives of underwater tow-fish using CFD(Computational Fluid Dynamics) are described in this paper. Main components of hydrodynamic derivatives are added mass, linear damping and non-linear damping coefficients. In this study, linear and non-linear damping coefficients for translational velocities are settled by CFD analysis. In order to analyze the underwater tow-fish, UlsanFOAM based on open-source CFD code, namely OpenFOAM, is employed. By simulating pitch and yaw angle variation of underwater tow-fish, 6DOF(Degree-of-Freedom) forces and moments are estimated at each attitudes. In order to determinate the hydrodynamic derivatives, curves(forces and moments vs attitude) for CFD results are fitted by least square methods. To demonstrate the applicability of the current approach, two different problems(impulsive side towing and straight towing) are simulated and all results are validated.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.376-385
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• 2017

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 $913m^2/n.mile^2$ in June and lowest at $315m^2/n.mile^2$ in July. The mean NASC of zooplankton was highest at $247m^2/n.mile^2$ in May and lowest at $70m^2/n.mile^2$ in July. The mean NASC of fish and zooplankton showed a significant difference (P < 0.05) with high correlation ($R^2=0.84$). 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 Journal of Fisheries Business Administration
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• v.50 no.1
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• pp.39-54
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• 2019

The purpose of this paper is to analyze the difference of seafood dining consumer behavior by demographic characteristics (age, gender). This research surveyed 251 people in Busan, Korea. t-test, one-way ANOVA, and MDS were used to identify the difference of consumer behavior by demographics. The result of the research revealed the difference between demographic characteristics and seafood dining consumption. 20's showed to accept the trendy dining culture represented by salmon, sushi and shrimp, and 30's also have similar tendency. 40's have higher spending tendency to seafood dining like tuna restaurants. 50's and 60's showed conservative consumption propensity represented by grilled fish, braised fish and raw fish restaurants. In gender analysis, male have higher frequency than female about grilled eel. In the future, the seafood dining market would be reorganized with the expansion of sushi, salmon and shrimp dishes, which can be classified as a new dining market. In this research, we suggested fisheries supply and production strategies according to age and gender.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.147.1-147
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• 2001

No Abstract, See Full Text

• Fisheries and Aquatic Sciences
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• v.20 no.11
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• pp.30.1-30.10
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• 2017

Small-scale fish farmers in developing countries are faced with challenges owing to their limited information on aquaculture management. Nile tilapia farmers in Teso North Sub-County recorded lower yields than expected in 2009 despite having been provided with required inputs. Water quality was suspected to be the key factor responsible for the low yields. This study sought to assess the effects of earthen pond water physico-chemical parameters on the growth of Nile tilapia in six earthen fish ponds under semi-intensive culture system in Teso North Sub-County. The study was longitudinal in nature with pond water and fish being the units of analysis. Systematic sampling was used to select five ponds while a control pond was purposively selected based on its previously high harvest. Four ponds were fed by surface flow and two by underground water. Each pond was fertilized and stocked with 900 fry of averagely 1.4 g and 4.4 cm. Physico-chemical parameters were measured in-situ using a multi-parameter probe. Sixty fish samples were randomly obtained from each pond fortnightly for four months using a 10 mm mesh size and measured, weighed and returned into the pond. Mean range of physico-chemical parameters were: dissolved oxygen (DO) 4.86-10.53 mg/l, temperature $24-26^{\circ}C$, pH 6.1-8.3, conductivity $35-87{\mu}S/cm$ and ammonia 0.01-0.3 mg/l. Temperature (p = 0.012) and conductivity (p = 0.0001) levels varied significantly between ponds. Overall Specific Growth Rate ranged between 1.8% (0.1692 g/day) and 3.8% (1.9 g/day). Ammonia, DO and pH in the ponds were within the optimal levels for growth of tilapia, while temperature and conductivity were below optimal levels. As temperature and DO increased, growth rate of tilapia increased. However, increase in conductivity, pH and ammonia decreased fish growth rate. Temperature and DO ranging between 27 and $30^{\circ}C$ and 5-23 mg/l, respectively, and SGR of 3.8%/day and above are recommended for higher productivity.