• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.26-35
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• 2015

This study compared the meat quality of sea rainbow trout Oncorhynchus mykiss frame muscle (S-FR-TY) and fillet (S-FI-TY) with the frame muscle of freshwater rainbow trout (F-FR). There was a difference of < 1% in the proximate composition of S-FR-TY vs. S-FI-TY, and of S-FR-TY vs. F-FR. The Hunter a value of F-FR-TY was lower compared with that of F-FR cultured in Jecheon (F-FR-JC), but higher than that of F-FR cultured in Pyeongtaek (F-FR-PT). However, no difference in the Hunter a value of S-FR-TY compared with any other F-FR was observed. The odor intensity of S-FR-TY was lower compared with that of F-FR, while the taste of S-FR-TY was milder than that of S-FI-TY, but stronger than that of F-FR. Although its total amino acid content was lower, the essential amino acid content of S-FR-TY was higher compared with S-FI-TY; the potassium content of S-FR-TY was also significantly greater. S-FR-TY contained high levels of nutritional and functional components, such as anserine, lysine, threonine, and eicosapentaenoic and docosahexaenoic acid. These results suggest that S-FR-TY could be used as a resource of canned food or fish jerky for children.

• Korean journal of food and cookery science
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• v.28 no.3
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• pp.249-255
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• 2012

The objectives of this study were to evaluate the physicochemical characteristics of puffer fish under storage conditions. Free amino acids were identified in the order of taurine > alanine > lysine > leucine > glutamic acid > valine. Glutamic acid, lysine, histidine, arginine, proline, and aspartic acid increased over time and with increased temperature, and valine and tyrosine were affected by temperature. ATP decreased dramatically during 36 h of storage at $4^{\circ}C$, 24 h of storage at $12^{\circ}C$, and 16 h of storage at $20^{\circ}C$. IMP reached its highest level when puffer fish was stored for 36 h at 4 and $12^{\circ}C$ and 24 h at $20^{\circ}C$, and hypoxanthine levels grew steeply at 60 h at $4^{\circ}C$, 24 h at $12^{\circ}C$ and 20 h at $20^{\circ}C$. In terms of K value, the puffer fish was available for sliced raw fish within 60 h at $4^{\circ}C$, 24 h at $12^{\circ}C$ and 12 h at $20^{\circ}C$, and the fish can be taken in after cooking within 72 h at $4^{\circ}C$ and $12^{\circ}C$ and 36 h at $20^{\circ}C$. The physicochemical quality characteristics showed that puffer fish is available for sliced raw fish within 36 h at $4^{\circ}C$, 16 h at $12^{\circ}C$ and 12 h at $20^{\circ}C$, and that the fish can be taken after cooking within 72 h at $4^{\circ}C$ and $12^{\circ}C$ and 36 h at $20^{\circ}C$.

• Journal of Welding and Joining
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• v.17 no.1
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• pp.124-132
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• 1999

Thermal fatigue strength of the solder joints is the most critical issue for TSOP(Thin Small Outline Package) because the leads of this package are extremely short and thermal deformation cannot be absorbed by the deflection of the lead. And the TSOP body can be subject to early fatigue failures in thermal cycle environments. This paper was discussed distribution of thermal stresses at near the joint between silicon chip and die pad and investigated their reliability of solder joints of TSOP with 42 alloy clad lead frame on printed circuit board through FEM and 3 different thermal cycling tests. It has been found that the stress concentration around the encapsulated edge structure for internal crack between the silicon chip and Cu alloy die pad. And using 42 alloy clad, The reliability of TSOP body was improved. In case of using 42 alloy clad die pad(t=0.03mm). $$\sigma$_{VMmax}$ is 69Mpa. It is showed that 15% improvement of the strength in the TSOP body in comparison with using Cu alloy die pad $($\sigma$_{VMmax}$=81MPa). In solder joint of TSOP, the maximum equivalent plastic strain and Von Mises stress concentrate on the heel of solder fillet and crack was initiated in it's region and propagated through the interface between lead and solder. Finally, the modified Manson-Coffin equation and relationship of the ratio of $N_{f}$ to nest(η) and cumulative fracture probability(f) with respect to the deviations of the 50% fracture probability life $(N_{f 50%})$ were achieved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1195-1203
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• 2012

Welding is a well-developed, widely used process for permanently joining metal components. However, the mechanical reliability of welded parts still offers room for improvement. A weld region consists of a fusion zone, a partially melted zone, and a heat-affected zone, and each zone has different material properties. In addition, the geometrical shape of a weld bead or fillet influences the mechanical reliability. A precise structural analysis must consider how a local welded region influences the mechanical behavior of the entire structure. This study focuses on an effective modeling scheme for the weld region. It relies on experimental and numerical methods to determine the proper correlation based on experimental results and to propose a modeling scheme for welded parts.

• Preventive Nutrition and Food Science
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• v.21 no.3
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• pp.281-288
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• 2016

This study was designed to investigate the effects of dietary astaxanthin levels on growth performance, feed utilization, muscle pigmentation, and antioxidant capacity in juvenile rainbow trout. Four experimental diets were formulated to contain 0, 50, 75, and 100 mg/kg astaxanthin (designed as AX0, AX50, AX75, and AX100). Each diet was fed to triplicate groups of fish (18.5 g/fish) for 10 weeks. Growth performance and muscle composition of fish were not affected by dietary astaxanthin levels. Total carotenoid concentration in the muscle of fish fed the AX50 diet was higher than that of fish fed the AX0 diet, but no significant differences were observed between these fish and those fed the AX75 and AX100 diets. Muscle astaxanthin content increased with increased astaxanthin in the diet. Deposition of astaxanthin in the flesh resulted in a decrease in lightness and an increase in redness and yellowness. The fillets from trout fed the AX75 diet had significantly lower lightness than trout fed the AX50 and AX100 diets. Fish fed the AX50 and AX75 diets showed significantly lower catalase activity than those fed the control diet. Total antioxidant status increased significantly in all astaxanthin supplemented groups when compared to the control group. Superoxide dismutase activity was significantly decreased in fish fed the AX50 diet compared to fish fed the AX0 diet. These findings suggest that while fillet pigmentation increased with increasing dietary astaxanthin concentration, indices of fish antioxidant capacity may not be affected in a dose dependent manner.

• Journal of Welding and Joining
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• v.27 no.4
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• pp.54-59
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• 2009

In the process to manufacture for metallic structures, control of welding deformation is one of an important problems connected with reliability of the manufactured structures so that welding deformation should be measured and controlled with quickly and actively. Also, welding parameters which have as lot of effects on welding deformation such as arc voltage, welding current and welding speed can also be controlled. The objectives for this study were to develop a simple 2-D FEM to calculate not only the transient thermal histories but also the sizes of fusion and heat-affected zone (HAZ) in multi pass arc welds including the butt and fillet weld type with dissimilar thickness, and to concentrate on a developed model for the finding the parameters of Godak's moving heat source model based on a GA. The developed model includes a GA program using MATLB and GA toolbox, and a batch mode thermal model using ANSYS software. Not only the thermal model was verified by comparison with Goldak's work but also the developed model was validated with molten zone section experimental data.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.253-260
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• 2011

This study was performed to investigate the physical, chemical and microbial characteristics of Gwamegi to provide basic data for the standardization of marine processed foods and for the improvement of the quality of commercial Gwamegi. The acid values of commercial Gwamegi were 5.8, 5.3 and 5.2 mg KOH/g for fillet type (F-type), "two divide" type (T-type) and whole type (W-type), respectively, and the peroxide values were 51.6, 51.5 and 53.2 meq/kg for each. There was a positive correlation between the acid value and the peroxide value (r=0.555) at confidence intervals (CI) of 99%. Trimethylamine (TMA) content of F-type, T-type and W-type products were 2.9, 2.6 and 3.6 mg%, respectively, while volatile basic nitrogen (VBN) contents were 22.4, 21.5 and 21.8 mg%. There was a strong positive correlation between TMA and VBN (r=0.961) at a CI of 99%. The histamine content was detected to be as much as 122 mg/kg, with about 36 % of the samples exceeding the CODEX criteria for histamine of 100 mg/kg. The total microbial count of 4 products exceeded 5 Log CFU/g and coliform group of 11 products exceeded the criteria of less than 1 Log CFU/g. Staphylococcus aureus in 27% of the samples exceeded the criteria of less than 2 Log CFU/g.

• Journal of the Society of Naval Architects of Korea
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• v.39 no.3
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• pp.81-88
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• 2002

The root joint in the welding structures are apt to failure by the stress concentration which is occurred by the external force. Therefore, in the safety and reliability of structure, the complete penetration joint welding which are obtained by the groove welding with edge preparation is generally required. Nevertheless, fillet T-joint welding without edge preparation is often carried out in the fields to reduce working time and consumption of welding electrode, however, this process is likely to produce inadequate joint penetration such as root gap. In this paper, the focus of research is to investigate distribution of welding residual stresses in the plate(or flange) and web of T-joint weld, and especially in the near of root gap notch that is due to incomplete joint penetration. For the analysis, we have chosen model of T-joint weld in the cases of single and multi-pass welding with submerged arc welding and analyzed model by using finite element programs considering the heat conduction and thermal elasto-plastic theory.

• Journal of Welding and Joining
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• v.34 no.6
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• pp.1-10
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• 2016

Flux Cored Wire is the most widely used welding material for Flux Cored Arc Welding these days. This paper introduces the technical aspects of manufacturing FCW and the development trend of FCW for each type of steel and metal. The studies are ongoing to lower the production cost of seamless-type FCW since it has not been generally used in welding shops so far because of it high cost even though the seamless-type FCW has various advantages than folded-type FCW in terms of manufacturing technology. Meanwhile, a technical research has been carried out to develop a rutile type of FCW products which satisfies high toughness after post heat treatment. In addition, for high-speed fillet welding, there has been a development of welding materials which can be welded in Single Auto-Carriage 100 cpm or more and up to Twin Tandem 200 cpm without occurring any welding defect in order to improve the welding productivity. As Zn coated steel is being used recently to improve the corrosion resistance of the automotive parts, a research and development for Metal Cored Wire has been conducted to reduce the Si island produced in welding operation than those produced when using the former solid wires. A development of welding material that guarantees CTOD performance beyond $-40^{\circ}C$ CTOD to $-60^{\circ}C$ is underway by different steel grades, and FCW for super austenitic stainless steel is being developed as the corrosion resistant steel has been upgraded.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.945-949
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• 2006

For a membrane bio-reactor, it is possible to fillet and separate activated sludge and effluent by head loss of centimeters, if non-woven fabric material is used as titration media. However, if non-woven fabric material is used to thicken high-concentration sludge, excessive sludge attachment causes the rapid decrease of flux. Mesh with fore sizes of $100{\mu}m,\;150{\mu}m,\;and\;200{\mu}m$ allows for easy separation of attached sludge. This study examined the possibility of mesh as filtration media. Existing close-flow filtration process, which requires maintaining sludge movement, makes It difficult to obtain high thickening rate. With a view of complementing this weakness, this study has made an experimental examination on how high-concentration sludge (about 3,000mg/L to 10,000mg/L) will be filtered and thickened when mesh module is submersed in the bio-reactor. Effluent flowed from the bottom of the bio-reactor by head loss of 65cm. In case of pore size of $100{\mu}m$, SS showed high recovery of 80% to 96%; therefore, it has been decided that mesh can be used as filtration media. Filtration lasted for more than 9 hours, until sludge with 9,000mg/L in MLSS concentration was thickened 9 times as dense. In the range from 3,610mg/L to 9,060mg/L in MLSS concentration, it was possible to obtain effluent with less than 2mg/L in MLSS concentration within 10 minutes.