• Journal of the Korean Geotechnical Society
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• v.22 no.7
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• pp.13-21
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• 2006

When enforced earth is used for the retain wall and four walls, the most important thing would be how to maximize the land utilization. Accordingly, in case of enforced earth, we pile up the minimal height of earth ($20{\sim}50\;cm$) and harden the earth using a static dynamic hardening machine. In this paper, we tried to analyze and compare the stress transformation characteristics of reinforced weathered granite soil with geosynthetics when repetitive load is added to the enforced earth structure and when static load is added. The result is that the cohesion component of the strength increased greatly and the friction component decreased slightly.

• Journal of the Korean Geotechnical Society
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• v.39 no.5
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• pp.5-12
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• 2023

This study investigates the existing models for estimating the shear strength of rock joints, presents related problems, and introduces a newly proposed model to overcome the problems. The results of many experimental tests show that the shear strength of a rock joint depends on many complex factors, including asperity angle, compressive strength, applied normal stress, friction angle, asperity cohesive strength, and progressive damage of asperities. However, the existing models do not account for these factors enough. To overcome these problems, Son (2020) developed a new model to estimate the shear strength of rock joints and confirmed its reliability by comparing with experimental results and existing models. In this paper, the developed model was used to investigate the various factors that affect the joint shear strength, and the results were compared and analyzed. Through this study, the factors that affect the shear strength of the rock joint could be identified in more detail.

• Composites Research
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• v.21 no.4
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• pp.7-14
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• 2008

Prediction of the load-bearing capacity of an adhesive-bonded Joint is of practical importance for engineers. This paper introduces interface fracture mechanics approach to predict the load-bearing capacity of composite metal bonded joints. The adhesion strength of composite/steel bonding is evaluated in terms of the energy release rate of an interfacial crack and the fracture toughness of the interface. Virtual track closure technique (VCCT) is used to calculate energy release rates, and hi-material end-notched flexure (ENF) specimens are devised to measure the interfacial fracture toughness. Bi-material ENF specimens gave consistent mode II fracture toughness $(G_{IIc})$ values of the composite/steel interface regardless of the thickness of specimens. The critical energy release rates of double-lap joints showed a good agreement with the measured fracture toughness. Therefore. the energy-based interfacial fracture characterization can be a practical engineering tool for predicting the load-bearing capacity of bonded joints.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1047-1060
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• 2003

To investigate the effects of conjugated linoleic acid added diet feeding on CLA accumulation and quality characteristics of pork meat. The CLA used to add in diet was chemically synthesized by alkaline isomerization method with corn oil. Pigs were divided into 5 treatment groups(4 pigs/group) and subjected to one of five treatment diets(0, 1.25% CLA for 2 weeks, 2.5% CLA for 2 weeks, 1.25% CLA for 4 weeks and 2.5% CLA for 4 weeks, CLA diets; total fed diets) before slaughter. Pork loin were collected from the animals(110 kg body weight) slaughtering at the commercial slaughter house. Pork loin meat were aerobic packaged and then stored during 2, 5, 8, 11 and 14 days at 4$^{\circ}C$. Samples were analyzed for shear force value, texture, TBARS, fatty acid composition, cholesterol and CLA content. CLA treatment groups showed significantly(p〈0.05) higher shear force value compared to those of control group at 11, 14 days of cold storage. All treatments were decreased significantly as the storage period passed. There was a not significantly difference in texture between control and CLA treatment groups. All CLA treatment groups showed significantly(p〈0.05) lower TBARS value than the control. TBARS value was increased significantly during storage in all treatment. CLA treatment groups showed significantly(p〈0.05) lower cholesterol content compared to those of control group. As dietary CLA was increased in feed, the content of CLA was increased, but the control was almost not detected. The contents of CLA were not significantly changed during chilled storage for 14 days. In the change of fatty acid composition, the contents of oleic, linoleic and arachidonic were decreased by dietary CLA-supplementation, whereas the increase level of CLA-supplementation resulted in the higher palmitic and stearic acid. In all results, CLA could be accumulated in pork meat and its antioxidant capability has been indicated. It was suggested that dietary CLA-supplementation could be produced high quality pork.

• The Korean Journal of Food And Nutrition
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• v.22 no.3
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• pp.321-331
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• 2009

In this study, Salvia miltiorrhiza Bunge(Danshen) powder was extracted with ethanol, and its antimicrobial activity was investigated. The ethanol extract of the Danshen had antimicrobial activity against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus. The inhibition zones of the Danshen extract(3 mg/disc) against B. subtilis, E. coli and S. aureus were 13, 12 and 8.5 mm, respectively. To test the food preservation effect of Danshen and determine the optimal ratio of the Danshen extract in a formulation, Sulgidduk samples were prepared with substitutions of 0, 0.25, 0.5, 0.75 and 1% Danshen extract, and then their quality characteristics were investigated over 4 days of storage. According to the results, total cell counts showed a decreasing trend with an increasing amount of added Danshen extract. Moisture contents were not significantly different among the Sulgidduk samples. As the content of Danshen extract increased, the L-values of samples decreased and the a- and b- values increased. For the textural characteristics, the hardness, gumminess, and chewiness of the Sulgidduk samples decreased as the amount of Danshen extract increased; however, they increased with the progression of storage time. In the sensory evaluation, the control group had significantly higher scores for color, flavor and after-taste as compared to the Danshen extract-added groups. With increasing Danshen extract contents, flavor and overall acceptability decreased, while Danshen flavor, bitterness and off-flavor increased. Chewiness was not significantly different among the samples. In conclusion, the results indicate that substituting 0.5% Danshen extract in Sulgidduk is optimal for quality and provides a product with reasonably high overall acceptability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.34-43
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• 1990

Six commerical rice varieties were cultivated and harvested at different locations in 1987 and 1988 to clarify the degree of locational variations. of several characteristics related to rice grain quality using the rice samples harvested from 8 to 20 locations for a variety each year. Locational variations of percent brown rice, percent milled rice, 1000-grain weight and amylose content were small, but whole grain rate, alkali digestibility, gel consistency, percent white-center and white-belly grain, degree of chalkiness and degree of translucency showed larger variations between locations. The degree of locational variation of sensory evaluation score for eating quality of cooked rice were varied from small to large along with rice variety used and year cultivated. Texture palatability index and stickiness of cooked rice among rheogram characteristics showed larger locational variations, but cohesiveness and springiness showed smaller variations between locations. Set back, break down and maximum viscosity showed larger locational variations among amylogram characteristics of rice flour. Special attention was given to a cultivated location, Anseong, because rice samples harvested at Anseong showed lower percent white-center and white-belly grain, and low set back and high break down in Chucheongbyeo, lower percent white-center and white-belly grain, higher texture palatability index and viscousness/hardness ratio, and low set back and high break down in Dongjinbyeo, higher texture palatability index, and low set back and high break down in Yongmunbyeo, lower percent white-center and white-belly grain in Sangpungbyeo, and low set back and high break down in Samkangbyeo. No other locations in this study produced rice samples showing wide acceptable quality-related characteristics except Anseong.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.111-117
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• 2007

This experiment was conducted to research the effects of Yellow Clay(YC) on the sensory evaluation of cooked meat in broiler chicks. A total of 216 one day old broiler chicks were divided into 6 groups at random. The six groups are consisted of one control group, to which no YC was added, and 5 groups to which an amount of YC was differently added. Diets contained 0.5, 1.0, 2.0, 4.0 and 8.0% of YC and fed to the 5 group broilers for 6 weeks. The lightness of meat in the broilers treated with YC was significantly higher than that of the control group in after-cooking(P<0.05). Besides, the lightness of meat was higher after-cooking than before-cooking. The properties of hardness, gumminess and chewiness were significantly lowered in the groups treated with Yellow Clay, as the amount of Yellow Clay increased at before-cooking and after-cooking(P<0.05). The turbidity of stock was higher in the groups treated with Yellow Clay as the percentage level of Yellow Clay increased, compared with the control group(P<0.05). The acceptability of color, flavor, and texture of meat and stock was higher in the groups treated with Yellow Clay, when compared with that of the control group(P<0.05). In total, the group treated with the 4 percentage of Yellow Clay was the highest in the overall preference(P<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.1
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• pp.15-23
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• 1979

In the first paper of the series the five soil fertility factors were evaluated by means of principal component analysis and varimax method. They are interpreted as representing, 1) skeletal available phosporus status, 2) organnic matter status, 3) salt status 4) base status, and 5) free oxide status. In order to resynthesize such fragmented information for the overall soil fertility evaluation, the method of multiple regression analysis was adopted, using the five factor scores and yield data for Korean paddy soils as independent and dependent variables respectively. As test of linear models with different combinations of independent variables the results of t-test of regression coefficient were revealed that the organic matter status (FII) has no relevance to the yield of paddy and that the free oxides and salt supply has by it self only an insignificant contribution to the yield. The multiple correlation coefficient (R) revealed its multiple regression analysis was as low as 0.43. Introduction of quadratic terms to the linear model bettered the result. Thus multiple correlation coefficient (R) was increased as 0.59. Therefore, a coefficient of determination 0.35 was obtained by a quadratic model with interaction terms among the five fertility constituents. Generally we think that the fertility factor has more contribution to raise the rice yield in paddy and that the failure of yield prediction by fertility factor scores was caused by one of follows; 1) the roughness of the yield inspection, and 2) missextraction of fertility constituents. The second step in this study, assuming that the residuals by multiple regression analysis were due to factors other than soil fertility, we can now proceed to predicting the yield from the field characters with the classified fertility groups by means of Hayashi's theory of quantification No. 1. Such variables as fertility groups (FTYG), water availability (WATER), soil drainage (DRNG), climatic zone (CLIZ), surface soil's stickiness (STCKT), surface soil's dry consistence (DCNST), and surface soil's texture (FTEXT) are taken up as the explanatory variables. The quantification appears reasonable; the well to extremely well in soil drainage, very sticky of surface soil, inefficiency in water availability, coarse texture, and very hard to extremely hard dry consistence in soil are detrimental to the rice yield. The R was as high as 0.90 for the set of variables. But the given explanatory variables in this study were not quite effective in explaining rice yield. The method developed seems to be promising only if properly collected data are available. Conditions that should be satisfied in the yield inspection obtained from common cultivator for the purpose of deriving a prediction equation were put forward.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.24-33
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• 2009

This study investigated the microbial contamination levels of raw meats used for short-ripened salami and changes in the microbial and physico-chemical properties of the product during storage at 10 and $25^{\circ}C$ for up to 120 days. The microbial counts of raw meats ranged between 2 and 4 Log CFU/g. Frozen-thawed sow meat showed higher total aerobe and Enterobacteriaceae counts than fresh chilled pork and pork back fat. Staphylococcus aureus was found in all raw materials except fresh chilled pork samples, and Clostridium perfringens was detected in a sample stored for 21 days at $25^{\circ}C$. The counts of total aerobes, lactic acid bacteria and Staphylococcus spp. decreased more rapidly at $25^{\circ}C$ than at $10^{\circ}C$ when the storage time was extended. The growth of Enterobacteriaceae, Pseudomonas spp., Clostridium spp., yeast, and mold were restricted to levels below 2 Log CFU/g during storage. The contents of salt, water, crude protein, crude fat, and ash of salami samples were 3.4, 33.4, 30.8, 32.7, and 4.3%, respectively, which were not affected by storage time or temperature. The pH value of the salami was initially 4.79 and increased to 5.02 and 5.26 after 120 days of storage at 10 and $25^{\circ}C$, respectively, whereas the water activity values decreased from an initial value of 0.91 to 0.90 and 0.88 after 120 days at 10 and $25^{\circ}C$, respectively. The TBA and VBN values increased slowly during storage. The redness value of the salami samples stored at $25^{\circ}C$ decreased more significantly than the samples stored at $10^{\circ}C$. With increased storage time, the values for the rheological characteristics of the salami in terms of hardness, brittleness, elasticity, cohesiveness, gumminess, and adhesiveness tended to decrease more remarkably at $25^{\circ}C$ than at $10^{\circ}C$. Based on sensory evaluation scores, it appears that short-ripened salami is no longer acceptable after 90 days at $10^{\circ}C$ and 30 days at $25^{\circ}C$.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.73-82
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• 2005

This study was conducted, based on the field survey and laboratory observations, to elucidate egg developmental processes and their characteristics of the Korean slender gudgeon, Squalidus gracilis majimae. For the experiments, the mature adults were collected at the Woongcheon-Cheon Stream and Boreung Reservoir located in Boreung City, Chungnam Province and eggs were obtained from the natural spawning area. Morphological characteristics of the egg and embryonic development were summarized as follows: The shape of the fertilized egg was spherical, adhesive and transparent. The fertilized egg was 2.9${\pm}$0.3 mm (n = 30) in mean diameter under water temperature of $26{\pm}1.5^{\circ}C$, light white in color and had no oil droplets. After 20 minutes from the time of fertilization, a blastodisc was formed and divided into two cells at 48 minutes after fertilization. The blastular stage occurred at 5 hours 40 minutes after fertilization and the gastrular stage was detected at 8 hours 41 minutes after fertilization. The beginning of embryo formation was observed at 12 hours 58 minutes after fertilization and optic vesicles and 9 somites were discovered at 17 hours 05 minutes after fertilization. Differentiation of brains and embryo wiggling were observed at 37 hours 27 minutes after fertilization. Heart beating and the formation of melanophores in optic vesicles were detected at 44 hours 46 minutes after fertilization. The formation of pectoral fins and melanophores in the body were discovered at 50 hours 36 minutes after fertilization. Hatching occurred at 57 hours 49 minutes after fertilization. The newly hatched larvae were 3.3${\pm}$0.2 mm (n = 120) in total length. We believe that these results may contribute the species and population conservations under the situation of accelerated water pollution and the decreases of its diversity.