• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.809-820
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• 2008

A new modified full scale double tee slabs with the length of nib plate - 1,500 mm were suggested, designed, and experimentally evaluated up to the loading of flexural failure. This slabs were composed of the tee section which was same to original PCI double tee and the plate section which was modified in a new shape, and the prestressing force was applied at the bottom of tee section only. This specimens were made from the domestic precast factory. The safety and serviceability of the modified nib plate with the dapped ends were evaluated up to the ultimate flexural strength of tee section. As the experimental loading increased, the flexural crackings developed first in the bottom of the slab and they changed to the increased flexural shear and inclined shear crackings in the nib and dapped portion of the double tees. The suggested modified double tee slabs failed in ductile above the design loading with many evenly distributed flexural crackings. The thickness of nib plate - 250 mm does not show any cracking under the service loading and show several minor flexural cracking up to the ultimate state of tee portion. The proposed specimens were satisfied with the strength and ductility requirements in the design code provisions in the tests. Additional experimental tests are required to reduce the depth and tensile reinforcement of nib plate concrete for the practical use of this system effectively.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.598-604
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• 2007

The current study was conducted to evaluate carcass characteristics, objectives and sensory meat qualities of Hanwoo longissimus muscle as affected by ultimate pH. Twenty-four steers and bulls ($556{\pm}53$ kg and $0.63{\pm}0.32$cm for live weight and backfat thickness, respectively) were used. As there was a linear relationship (r = 0.77) between lean meat color and ultimate pH, cattles were thus segregated into normal $pH{\leq}5.8$, Normal, n = 13) and DFD (pH>5.8, n = 11) groups. Normal pH group had significantly (p<0.05) higher carcass weight, marbling score and backfat thickness than those for high pH group, while fat color and lean meat color were inverse. In principle component analysis for co-ordinates of DFD and normal meats, fat color, lean meat color, texture, time to pH 6.2 and pH at 24 h postmortem were associated with the positive range of the first factor (67.5%) while backfat thickness marbling score and temperature at 24 h were placed in negative values. The rate constant of decline in pH (pH k) did not differ between the two groups, implying that initial pH (i.e., pH at slaughtering) differed between two groups. Contour mapping of pH k between pH at 1 and 24 h postmortem indicated that high pH k was related to lower pHs at 1 and 24 h postmortem. This suggested that the high pH cattles (i.e., DFD cattle) resulted from their own potential. Although the time to reach pH 6.2 was significantly (p<0.05) shorter for normal meat (i.e., 3.2 h) than that for DFD one (i.e., 19.8 h), there were no significantly differences in both WB-shear force and sensory attributes. Given that the experimental animals were sampled from a similar group, which implies a similar myoglobin pigment content, the current data suggested that pre- and post-slaughter animal handling likely had a significant effect on ultimate pH and consequently meat color of Hanwoo longissimus muscle, and also small animals with lower marbling score and backfat thickness had a higher risk for DFD meat.

• Journal of Animal Science and Technology
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• v.58 no.6
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• pp.23.1-23.17
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• 2016

Background: The functionality of myofibrillar proteins is a major factor influencing the quality attributes of muscle foods. Nonetheless, the relationships between muscle type and oxidative changes in chevon during ageing are meagrely elucidated. Postmortem changes in antioxidant status and physicochemical properties of glycolytic gluteus medius (GM) and oxidative infraspinatus (IS) muscles in goats were compared. Methods: Twenty Boer bucks (9-10 months old, body weight of $36.9{\pm}0.725kg$) were slaughtered and the carcasses were subjected to chill storage ($4{\pm}0.5^{\circ}C$). Analyses were conducted on GM and IS muscles sampled on 0, 1, 4 and 7 d postmortem. Results: Chill storage did not affect the antioxidant enzyme activities in both muscles. The IS had greater (P < 0.05) superoxide dismutase and catalase activities than GM. Carotenoid and tocopherol contents did not differ between muscles but decreased (P < 0.05) over storage. The IS had higher (P < 0.05) glycogen and ultimate pH and lower (P < 0.05) shear force and cooking loss than GM. The carbonyl content, % metmyoglobin, drip loss and TBARS increased (P <0.05) while free thiol, metmyoglobin reducing activity (MRA), shear force and myoglobin decreased (P < 0.05) over storage. Muscle type had no effect (P > 0.05) on free thiol, MRA and TBARS. The GM had lower (P < 0.05) redness on d 0 and 1 than IS while the IS had greater carbonyl, % metmyoglobin and drip loss than GM on d 7. The reflective density of slow myosin heavy chain (MHC) was higher (P < 0.05) while the density of fast MHC and actin was lower (P < 0.05) in IS than GM. Regardless of muscle type, the density of MHC decreased (P < 0.05) while that of actin was stable over storage. Nonetheless, the degradation of fast and slow MHC was greater (P < 0.05) in IS than GM. Muscle type had no effect (P > 0.05) on consumer preference for flavour, juiciness and overall acceptability. However, IS had higher (P < 0.05) tenderness score than GM on d 1 and 4 postmortem. Intramuscular fat was higher (P< 0.05) in IS compared with GM. Fatty acid composition did not differ between the muscles. However, GM had lower (P < 0.05) n-6/n-3 ratio than IS. The n-3 and n-6 PUFA declined (P < 0.05) while the SFA increased (P < 0.05) over storage. Conclusion: The changes in myofibrillar proteins and physicochemical properties of goat meat during postmortem chill storage are muscle-dependent.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.289-296
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• 2011

Swine industry in Korea plays an important role in providing the meat for domestic consumption, and the number of pigs in Korea was about 9.72 million heads as of June, 2010. Meat quality is used to describe any traits which impact the consumer acceptability of fresh meat products. Meat color, firmness, water holding capacity, ultimate muscle $pH_{24h}$ (measured 24 hours post-mortem), shear force, and intramuscular fat percentage (IMF) are generally accepted as important indicators of meat quality and ultimately, consumer acceptance of fresh pork. The objective of this study was to estimate genetic parameters for meat quality traits in Berkshire pigs. The heritability estimates for muscle $pH_{24h}$, lightness (CIE $L^*$), NPPC marbling were 0.61, 0.56 and 0.57, respectively, The heritability estimates for drip loss, cooking loss, shear force were 0.51, 0.66 and 0.56, respectively. The phenotypic correlations between $pH_{24h}$ and lightness (CIE $L^*$), drip loss, cooking loss were negative, ranging from -.45 ~ -.13. The genetic correlations between muscle $pH_{24h}$ and lightness (CIE $L^*$), drip loss were negative, ranging from -.35 ~ -.32. Genetic parameters obtained herein indicate that genetic improvement of muscle $pH_{24h}$ is not related to the NPPC marbling of meat, but rather to improved lightness(CIE $L^*$) and drip loss. Genetic trends of meat quality traits showed increased muscle $pH_{24h}$ and decreased cooking loss and drip loss.

• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.259-266
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• 2012

A general earthquake resistant design philosophy of ductile frame buildings allows beams to form plastic hinges adjacent to beam-column connections. In order to carry out this design philosophy, the ultimate bond or shear strength of the beam should be greater than the flexural yielding force and should not degrade before reaching its required ductility. The behavior of RC members dominated by bond or shear action reveals a dramatic reduction of energy dissipation in the hysteretic response due to the severe pinching effects. In this study, a method was proposed to predict the deformability of reinforced concrete members with short-span-to-depth-ratios, which would result in bond failure after flexural yielding. Repeated or cyclic loading produces a progressive deterioration of bond that may lead to failure at lower cyclic bond stress levels. Accumulation of bond damage is caused by the propagation of micro-cracks and progressive crushing of concrete in front of the lugs. The proposed method takes into account bond deterioration due to the degradation of concrete in the post yield range. In order to verify bond deformability of the proposed method, the predicted results were compared with the experimental results of RC members reported in the technical literature. Comparisons between the observed and calculated bond deformability of the tested RC members showed reasonably good agreement.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.753-760
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• 2020

The objective of this study was to investigate the influence of increasing carcass weight (CW) on meat quality traits including meat color, water-holding capacity (WHC), tenderness, backfat thickness and intramuscular fat (IMF) content of pork loin. A total of 96 pork carcasses (48 LYD [Landrace × Yorkshire × Duroc] barrows and gilts) were selected at a commercial slaughterhouse. Each gender had commercial CW (≤ 90 kg), heavy CW (91-100 kg) and very heavy CW (> 100 kg) (16 carcasses from each CW group). Loin cuts (Longissimus lumborum) were excised to investigate meat color (CIE L*a*b*), drip loss, cooking loss, released water, Warner-Bratzler shear force (WBSF), and IMF content. Backfat thickness and IMF content of pork loin samples were significantly (p < 0.05) increased with increasing CW, although there was no significant difference in ultimate pH (pHu). CIE a* increased significantly (p < 0.05) with increasing CW, while there were no significant differences in CIE L* or CIE b* among CW groups. Although all WHC measures showed no significant differences among CW groups, WBSF increased significantly (p < 0.01) with increasing CW. Sensory flavor score was significantly increased while panel score for tenderness was decreased significantly (p < 0.001) with increasing CW. Consequently, CW had a positive correlation with flavor but negative correlation with tenderness. These results indicate that the increased IMF content improves flavor, juiciness and palatability, although tenderness deteriorates with increasing CW.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.676-683
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• 2011

The aim of this study was to compare the physicochemical changes of hot-boned chicken breast and leg muscles. Chicken breast and leg muscles from 56 broilers were excised within a 15 min post-mortem (PM) and stored at $20^{\circ}C$. Physicochemical traits were determined at 0.5, 6, 12, and 24 h PM. The ultimate pH of leg muscle was higher than that of breast muscle (p<0.05). The content of glycogen in the breast muscle was relatively higher than that in the leg muscle until 6 h PM (p<0.05). R-values showing rigor mortis of breast and leg muscles were completed after or before 6 h PM. Breast muscle had less cooking loss than leg muscle (p<0.05). Drip loss did not significantly differ between breast and leg muscles with the exception of that at 6 h PM. The sarcomere length of leg muscle was relatively longer than that of breast muscle (p<0.05). The MFI of leg muscle was significantly lower than that of breast muscle (p<0.05). The shear force of leg muscle was lower than that of breast muscle at 6 and 12 h PM (p<0.05); however, that of both muscles did not significantly differ at 24 h PM.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.238-244
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• 2014

This study was conducted to compare the carcass characteristics and meat quality characteristics of Duroc breed and crossbred pigs (Landrace ${\times}$ Yorkshire ${\times}$ Duroc, LYD). Duroc and crossbred pigs did not show differences in carcass characteristics. Crossbred pigs had higher moisture and protein content than Duroc breeds. However, Duroc breeds had a higher fat content than the crossbred pigs. In meat quality characteristics, crossbred pigs showed higher values of drip loss and cooking loss over Duroc breeds, while Duroc breeds showed higher ultimate pH value compared to that of crossbred pigs. However, there were no differences in water holding capacity and shear force value. In myoglobin content, crossbred pigs had higher content compared to that in the Duroc population. In subjective evaluation and sensory characteristics, Duroc breeds showed significantly higher scores in all categories except for tenderness over the crossbred pigs. However, in storage characteristics, Duroc breeds showed reduced tendency relative to crossbred pigs. Crossbred pigs had higher unsaturated fatty acid content than Duroc breeds did. In these results, Duroc breeds showed excellent meat quality characteristics with its higher intramuscular fat content and pH value, lower drip loss and cooking loss and higher juiciness and flavor, compared to the crossbred pigs.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.898-904
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• 2006

Effects of sodium bicarbonate (SBC) injection on meat quality and functionality of porcine M. longissimus lumborum were investigated. Fifteen pigs ($100{\pm}5kg$) were randomly selected at a commercial slaughter plant. After slaughtering the loins were dissected from the carcass before chilling at approximately 30 minutes post mortem. The loins were divided into four cuts for sample treatment, and SBC of 0.25 M, 0.40 M and 0.75 M was injected (2% w/w) using a syringe. As SBC injection level was increased, muscle pH increased significantly (p<0.05). SBC injection decreased lightness ($L^*$) values on the surface of muscle. Moreover, with injection of SBC, drip loss %, cooking loss % and shear force were significantly (p<0.05) decreased, whereas WHC and $Na^+$ content were significantly (p<0.05) increased. From panel testing of uncooked pork loin, no significant differences (p>0.05) were found in aroma, off-flavor and drip between injection of SBC at different levels and the control, although color and acceptability were significantly lower (p<0.05) in control pork loin compare with injection of SBC at 0.75 M. In cooked pork loin from the panel test, aroma, flavour, off-flavour and juiciness were found to be similar (p>0.05) on all treatments, but tenderness and acceptability were significantly higher (p<0.05) with injection of SBC at 0.75 M than for control loin. Myofibrillar protein solubility of muscles treated with SBC was significantly (p<0.05) higher than that of the control, although no significant differences (p>0.05) were found in sarcoplasmic protein solubility between the treatments. These results indicated that SBC injection into pre-rigor porcine M. longissimus lumborum could improve ultimate pork quality characteristics such as meat color, water-holding capacity, and could inhibit muscle protein denaturation due to an increase in muscle pH.

• Journal of Korean Society of Steel Construction
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• v.19 no.5
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• pp.503-513
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• 2007

The seismic responses of a building are affected by the connection characteristics that have effects on structural stiffness. In this study, push-over analysis and time history analysis were performed to estimate structural behavior of 2D eight-story unbraced steel structures with partially restrained composite connections using a nonlinear dynamic analysis program. Nonlinear $M-{\theta}$characteristics of connection and material inelastic characteristics of composite beam and steel column were considered. The idealization of composite semi-rigid connection as fully rigid connection yielded an increase in initial stiffness and ultimate strength in the push-over analysis. In time history analysis, the stiffness and hysteretic behavior of connections have effects on base-shear force, maximum story-drift and maximum moment in beams and columns. For seismic waves with PGA of 0.4 g, the structure with the semi-rigid composite connections shows the maximum story-drift with less than the life safety criteria by FEMA 273 and no inelastic behavior of beam and column, whereas in the structure with rigid connections, beams and columns have experienced inelastic behaviors.