• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.1
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• pp.239-246
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• 2017

There are various transversal structures (small dams or drop structures) in median and small streams in Korea. Most of them are concrete structures and it is so hard to exclude low-level water. Unless drainage valves and/or gates would not be installed near bottom of bed, sediment from upstream should be deposited and also contaminants attached to the sediments would devastatingly threaten the water quality and ecosystem. One of countermeasures for such problem is the bypass pipe installed underneath the transversal structure. However, there is still issued whether it would be workable if the gravels and/or stones would roll into and be not excluded. Therefore, in this study, the conditions to exclude the rip stone which enter into the bypass pipe was reviewed. Based on sediment transport phenomenon, the behavior of stones was investigated with the concepts from the critical shear stress of sediment and d'Alembert principle. As final results, the basis condition (${\tau}_c{^*}$) was derived using the Lagrangian description since the stones are in the moving state, not in the stationary state. From hydraulic experiments the relative velocity could be obtained. In order to minimize the scale effect, the extra wide channel of 5.0 m wide and 1.0 m high was constructed and the experimental stones were fully spherical ones. Experimental results showed that the ratio of flow velocity to spherical particle velocity was measured between 0.5 and 0.7, and this result was substituted into the suggested equation to identify the critical condition wether the stones were excluded. Regimes about the exclusion of stone in bypass pipe were divided into three types according to particle Reynolds number ($Re_p$) and dimensionless critical shear force (${\tau}_c{^*}$) - exclusion section, probabilistic exclusion section, no exclusion section. Results from this study would be useful and essential information for bypass pipe design in transveral structures.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.422-430
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• 2008

This study was conducted to investigate the nutritional composition and meat quality properties of Hanwoo steer beef by different cut. Ten cuts [Abjin (short plate), Bosup (top sirloin), Cheggt (striploin), Dngsim (loin), Guri (chuck tender), Hongduke (eye of round), Moksim (chuck roll), Sulgit (bottom round), Udoon (top round), Yanaji (brisket)] prepared from 10 Hanwoo steers (28-30 months old) were used for this experiment. The range of pH was 5.46-5.64. In the chemical analysis, Hongduke contained highest protein contents (21.15%) and Dngsim had lowest protein contents (16.94%) (p<0.05). Fat contents were higher in Dngsim whereas those of Guri, Hongduke and Udoon were significantly lower when compared to the other cuts (p<0.05). There were not significantly different in meat color (L, a and b values) properties only except that L values were significantly higher in Dngsim among 10 cuts (p<0.05). Cooking loss (%) was higher in Guri, Hongduke, Udoon and Yangji whereas it was significantly love. in Cheggt (p<0.05). Warner-Bratzler shear force (WBS) was significantly higher in Abjin $(6.24inch^2/kg)$, whereas Dngsim $(3.45inch^2/kg)$ and Cheggt $(3.50inch^2/kg)$ were significantly lower than the other cuts (p<0.05). There was no significant difference in water-holding capacity (WHC) among 10 cuts (p>0.05). Total amino acid contents were significantly higher in Hongduke (p<0.05). Hongduke was highest in most kinds of amino acids, however, Udoon had the highest methionine and histidine contents among 10 cuts (p<0.05). Glutamate contents were high in all cuts and followed by aspartate, leucine and lysin. With regard to mineral contents, Ca was ranged from 47.63-70.69 mg/kg and Fe was ranged from 15.09-26.68 mg/kg in 10 cuts. Zn was highly contained in Guri (50.56 mg/kg) when compared to the other cuts (p<0.05).