• Journal of the Korean Geosynthetics Society
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• v.8 no.2
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• pp.47-54
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• 2009

The ballast track, the most common type of conventional railroad track in Korea, is deteriorated by abrasion of ballast, it's penetration into roadbed, and rugged surface of roadbed caused by cyclic loading of train. Persistent occurrence of those phenomena lead to insufficient drain capacity, one of major factors in track design, and it increases pore water pressure and decreases of shear strength under rainfall condition leading to unstable roadbed. In this study, cylindrical model tests are executed for 3 types of geotextile applying cyclic loading in order to observe the characteristics of displacement and bearing capacity of geotextile, and undrained condition has been applied for 0 day, 3 days and 7 days to each geotextiles. The results showed that there was about 1% difference at the final displacement rates between reinforced soils and nature soils and the displacement of the ground surface increases along with the degrees of the saturation. And in case that water contents exceeds the threshold, it is also apparent that weight and tensile strength of geotextile influences displacement of the ground surface. And the larger weight of geotextile is, the smaller plastic displacement. It is evaluated that non-woven fabric comes into effect on reducing the bearing capacity but, the weight of geotextile has little influence on it.

• Journal of Energy Engineering
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• v.24 no.1
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• pp.114-122
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• 2015

In the high convective gas flow condition, irregular shaped water waves from which droplet entrainment occurs are generated under horizontally stratified two-phase flow condition. KAERI proposed a new mechanistic droplet entrainment model based on the momentum balance equation consisting of the shear stress, surface tension, and gravity forces. However, this model requires correlation or experimental data of several physical parameters related to the wave characteristics. In the present study, we tried to measure the physical parameters such as wave slope, wave hypotenuse length, wave velocity, wave frequency, and wavelength experimentally. For this, an experiment was conducted in the horizontal rectangular channel of which width, height, and length are, respectively, 40 mm, 50 mm, and 4.2 m. In the present test, the working fluids are chosen as air and water. The PIV technique was applied not only to obtain images for phase interface waves but also to measure the velocity field of the water flow. Additionally, we developed the parallel wire conductance probe for the confirmation of wave height from PIV image. Finally, we measured the physical parameters to be used in the validation of new droplet entrainment model.

• Journal of the Korea Institute of Building Construction
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• v.19 no.3
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• pp.201-207
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• 2019

In this study, the direct tensile properties of amorphous metallic fiber-reinforced cement based composites according to the strain was evaluated. A thin plate-shape amorphous metallic fiber with 15mm and 30mm in length was used. And fiber-reinforced cement based composites were prepared with contents of 1.0, 1.5, 2.0%. The direct tensile test was conducted under the conditions of $10^{-6}/s(static)$ and $10^1/s(dynamic)$ strain rate. As a results, amorphous metallic fiber with a length of 15mm was observed in pull-out behavior from the cement matrix because of the short fiber length and large portion of mixed fiber. On the other hand, amorphous metallic fiber with a length of 30mm were not pulled out from matrix because the bonding force between the fiber and matrix was large due to rough surface and large specific surface area. However, fracture occurred because thin plate shape fibers were vulnerable to shear force. Tensile strength, strain capacity and toughness were improved due to the increase in the fiber length. The dynamic increase factor of L15 was larger that of L30 because the bonding performance of the fiber-matrix interface is significantly affected by the strain rate.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.71-79
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• 2017

Purpose: Ni-Cr alloy does not contain Beryllium, causing the metal compound to form oxides in the furnace but by using Titanium as a chemical catalyst the forming of the oxides can be controlled, and by controlling the impurities formed on the metal surface, the possibility of the Ni-Cr alloy bond strength being increased can be analysed. Materials and Methods: Titanium was used as a chemical catalyst in the porcelain for the oxidation of beryllium-free metal (Ni-Cr) alloy. The T1 group, which does not use Titanium power as a chemical catalyst is a reference model for comparison. The T2 group and T3 group used 10 g and 20 g of Titanium power, respectively. They are fabricated to observe the shear bond strength and surface properties. There was no significance when One-way ANOVA analysis/Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups (P > 0.05). Results: Results of measuring the three-point flexural bond strength of the Ni-Cr alloy and thickness of the oxide film. Experiment T3 using 20 g Titanium chemical catalyst: $39.22{\pm}3.41MPa$ and $6.66{\mu}m$, having the highest bond strength and thinness of oxide film. Experiment T2 using 10 g Titanium chemical catalyst: $34.65{\pm}1.39MPa$ and $13.22{\mu}m$. Experiment T1 using no Titanium chemical catalyst: $32.37{\pm}1.91MPa$ and $22.22{\mu}m$. Conclusion: The T2 and T3 experiments using Titanium chemical catalyst showed higher bond strength for the Ni-Cr alloy and lower thickness of oxide film than experiment T1, and the titanium catalyst being able to increase bond strength was observed.

• Food Science of Animal Resources
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• v.24 no.4
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• pp.319-325
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• 2004

The objective of the present study was to investigate the effect of processing conditions on the physical and sensory properties of pork cutlet produced from chilled pork loin (T1), the cured and massaged chilled pork loin (T2), the cured and massaged frozen pork loin (T3), frozen pork loin (T4), massaged frozen pork loin (T5). Water holding capacity (WHC) of pork cutlets were not significantly different among the treatments. In chilled pork loin, WHC of T2 were slightly higher than that of T1. T4 showed the lowest WHC among all treatment group. In meat color, CIE L$\^$*/, a$\^$*/. b$\^$*/ values in chilled pork loin were not significantly different between T1 and T2. L$\^$*/ values of T3 and T5 were higher than that of T4. a$\^$*/ values were not significantly different among the all treatments. T3 produced through the curing and massaging treatment showed the highest tenderness in shear force (p< 0.001), while force value (kg/㎤) of T4 were the highest among all treatments. Separation ratio of wheat dough from pork cutlet was highest (p.<0.001) in T4. In triangle test, T1 : T3 combination was higher than that of other pairs. No differences in acceptability of sensory evaluation were observed among T1, T2, T3, and T5 groups, while the frozen pork showed the lowest (p<0.001) acceptability. In conclusion, pork cutlets from T4 with the curing and/or massaging process showed similar acceptance than those from chilled pork loins, and this treatments may contribute to promote the consumption of frozen pork loins.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1059-1066
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• 2005

The objective of this study was to investigate the physico-chemical characteristics of chicken breast surimi processed by four times washing (C) and adjustment to pH 3.0 (T1) and pH 11.0 (T2). Water, crude protein, myofibrillar protein and yield of the treatment C were lower compared to other two treatments. Crude fat of T2 was higher than other two treatments. pH, WHC, breaking force and deformation were not different among the treatments. Shear force of T2 was the highest, followed by T1 and C. L* of T2 and a* of T1 were lower than other two treatments. b* of C was the highest, while T2 was the lowest. Brittleness and hardness in textural properties were not different among the treatments. Cohesiveness of T1 was the lowest among three treatments. Springiness and chewiness of T1 and T2 were higher than those of treatment C, respectively. Gumminess of T2 were higher compared to C and T1. Appearance and flavor in sensory evaluation were the highest in T1 and the lowest in C among three treatments. Color, aroma, juiciness, tenderness and overall acceptability were not different among the treatments. In conclusion, physico-chemical quality of chicken breast surimi was the highest in T2 among three treatments.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.747-758
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• 2006

A total of 30 pigs (average 60kg) were used to investigate the influence of breeds on meat quality. Pigs were alloted into one of three experimental groups [A (Landrace×Yorkshire×Duroc), B (England Berkshire), and C (Kagoshima Berkshire)]. Pigs were slaughtered at approximately 110kg of live weight for measurement of meat qualities. Crude protein was significantly higher in B than those of other pig breed groups. Shear force value was higher and pH was lower in A than those of other pig breeds. In color, C was significantly higher in a* of meat color and lower in b* of fat color and in brittleness, hardness, springiness, chewiness as compared with other pig breeds. Essential fatty acid were significantly higher in A and lower in B than those of other pig breeds. Aspartic, threonine, serine, glutamic and phenylalanine were higher in C, whereas glycine, alanine, cystine, valine, leucine, tyrosine, histidine, lysine and arginine were significantly higher in A. In sensory evaluation of fresh meat, color was significantly higher in C. However, moisture, crude fat, crude ash and drip loss, marbling score, overall acceptability of fresh meat and all items in sensory evaluation of cooked meat were not significant difference among the pig groups. In conclusions, loin from Kagoshima Berkshire had the lowest shear force and the highest a* value. In the current study few effects of pig breeds were observed. Further studies are needed on the relationship between physico-chemical properties and the pig breeds.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.373-382
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• 2010

This study was carried out to investigate the effect of reverse osmosis (RO)-treated deep sea water (DSW) supplementation on the quality characteristics of chicken breast meat. For 28 days, one-day-old broiler chicks (Ross 308) were divided into two groups and supplemented with either water (control) or RO-treated DSW (diluted with deionized water at 1:20 [RO-treated DSW:deionized water] ratio). The control group was fed on a basal diet containing 0.21% salt. Five birds were slaughtered on each group and breast meat from carcasses was stored at $4^{\circ}C$ for 9 days. The proximate composition, fatty acid composition, cholesterol content, mineral content, pH value, water-holding capacity and Warner-Bratzler shear force value were not affected by RO-treated DSW supplementation. At 6 day of storage, lipid oxidation (2-thiobarbituric acid reactive substances) was significantly higher in RO-treated DSW group than in the control (P<0.05). With regard to meat color, CIE $L^*$ value was significantly lower in RO-treated DSW group than in the control after 6 day of storage (P<0.05), whereas CIE $a^*$ and $b^*$ values were not significantly different between two groups during storage. Consequently, RO-treated DSW supplementation led to a darker color and reduced the lipid oxidation stability in chicken meat during storage. Therefore, these results may indicate that RO-treated DSW can not be used as drinking water of chickens because it negatively affects the quality of chicken meat.

• Food Science of Animal Resources
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• v.27 no.3
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• pp.320-328
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• 2007

This study was conducted to determine the effect of pH adjustment and the addition of cryoprotectants on the quality characteristics of chicken breast surimi. We prepared surimi from Alaska pollack, as a the control, by two time washing times and the addition of cryoprotectants. Different preparations of surimi were manufactured by adjusting to pH 11.0 and the addition of different addition cryoprotectants during frozen storage (T1 : 5% sorbitol and 0.3% polyphosphate, T2: 4% sugar, 5% sorbitol and 0.3% polyphosphate, and T3: 2% salt, 4% sugar, 5% sorbitol and 0.3% polyphosphate). The moisture content was significantly lower in the control and T3 samples. The crude protein content was increased with storage times. The crude protein was higher in the control. The water-holding capacity, myofibrillar protein and shear force were significantly higher in T3 than other surimi samples. All gel characteristics were significantly higher in the control and T3 than other surimi samples. pH 11.0 adjusted chicken breast surimi had greater lightness than the control, and T3 samples had the highest lightness and whiteness. Sensory evaluations were significantly higher in the control and T3 than the other samples. The gel, and physical characteristics and sensory evaluation of T3 were similar to the control. T3 samples had superior color and pH than the control Alaska pollack surimi.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.187-193
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• 2005

This study was carried out to investigate the effect of the bleeding times(30sec., 90sec., 150sec.) at slaughtering process on meat quality and storage properties of broiler. The redness$(a^{\ast}\;value)$ of skin, wing, leg muscle decreased at high bleeding time(150sec.). However, there was no significant difference in breast muscle. WHC(water holding capacity) of breast muscle decreased from $63.64\%$ at low bleeding time(30sec.) to $61.06\%$ at high bleeding time. TBARS(thiobarbituric acid-reactive substance) values were 0.18 mgMA/kg at the low bleeding time, 0.16 mgMA/kg at the middle bleeding time(90sec.) and 0.21mgMA/kg high bleeding time on 3 days of storage. Total aerobic plate counts(TPC) were $6.25logCFU/cm^2$ at the low bleeding time, $6.25logCFU/cm^2$ at the middle bleeding time and $6.53logCFU/cm^2$ at the high bleeding time. The TPC was increased as the bleeding time increased. In conclusion, meat color of chicken were acceptable when the carcasses were slaughtered at the high bleeding time.