• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.23-28
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• 1994

This study was rimed out to examine the difference in the cell vitality between mesophyII protoplast (MP) and paraveinal mesophyII protoplast (PVMP) of Nicotiana tabaccum 'Xanti', Petunia hybrida 'Blue Star' and Chrysanthemum morifolium 'Baeckwang' by using urea permeability technique. The effects of various enzyme solutions and incubation time, NAA and thidiazron on plant regeneration from isolated protoplasts were also investigated. The vibratome technique was used for protoplast isolation and urea permeability test because the fresh living, thin tissue stripes (50 ${\mu}{\textrm}{m}$ of thickness) could be obtained with minimal damage with the vibratome. For the three plants examined, the urea permeability on the tested tissue stripes was relatively higher in PVMP than in MP by about Ks = 2.0 $\times$ 10$^{-5}$ cm/sec. The treatment of an enzyme mixture of 1.5% cellulase R-10, 1% Driselase, 0.5% Macerozyme R-10, and 0.5% Pectinase for 4 to 8 h was effective on the isolation of PVMP. The highest frequency of callus formation and plant regeneration from the isolated protoplasts was obtained with NAA 2 mg/L and thidiazuron 0.01 mg/L. Furthermore, the results demonstrated that cell devision and plantlet regeneration was more frequent in the PVMP than in the MP of the same leaf or plant We, therefore, conclude that UM is an excellent experimental material for the callus formation and regeneration from isolated protoplasts.

• Journal of the Korea Concrete Institute
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• v.15 no.2
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• pp.234-245
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• 2003

Most of the concrete bridge structures are exposed to damage due to the excessive traffic loading and the aging of the structure. The damage of concrete causes the further deterioration of the function in the concrete structure due to corrosion of the reinforced bars and decohesion between the concrete and the reinforced bar. The quick rehabilitation of the damaged concrete structures has become of great importance in the concrete structural system in order to avoid the further deterioration of the structures. Recently fiber sheets are used for strengthening the damaged concrete structures due to its many advantages such as its durability, non-corrosive nature, low weight, ease of application, cost saving, control of crack propagation, strength to thickness ratio, high tensile strength, serviceability and aesthetic. However, the lack of analytical procedures for assessing the nominal moment capacity by the fiber sheet reinforcement leads to difficulties in the effective process of decisions of the factors in the strengthening procedure. In this work, flexural strengthening effects by fiber sheets bonded on bottom face of the member are studied for the reinforced concrete T beam. In addition, auxiliary flexural strengthening effects by U-type fiber sheets bonded on bottom and side faces of the member to prevent delamination of the bottom fiber sheet are theoretically investigated. The analytical solutions are compared with experimental results of several references to verify the proposed approach. It is shown that the good agreements between the predicted results and experimental data are obtained.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.45-50
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• 2001

Open rack vaporizer (ORV) has been used in liquefied natural gas (LNG) receiving terminal in order to vaporize LNG into natural gas (NG) by heat exchange with seawater The U-type ORV which had been operated with seawater for 14 years is one of the important utilities of the gas production and the weld part of tube connected with header_ pipe had experienced many corrosion problems. To elucidate the cause of corrosion at weld part of vaporizer tube, corrosion potentials were compared by parts. This study concerns on the measurement of corrosion pit depth using non-destructive method and the evaluation of stress distribution in an aspect of safety with finite element analysis. In order to confirm the reliability of galvanic corrosion between weld parts and base metal, the measurement of corrosion potential by parts was conducted for 20 minutes in 3.5$\%$(wt.) NaCl solution. Many non-destructive methods were tried to measure the remaining thickness of vaporizer tube at fields. For general corrosion, tangential radiography test was confirmed as an effective method. In case of a fine corrosion pit, the shape of corrosion pit was reproduced using surface replication method. From collected data, stress distributions were quantitatively evaluated with 2-dimensional finite element method and the diagnostic evaluation on internal pressure of the U-type vaporizer could be made.

• Journal of The Korean Association For Science Education
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• v.31 no.4
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• pp.587-599
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• 2011

The purpose of this study was to analyze variable-controlling strategy (below vcs) and the ability to infer the effect of variables in Middle school students who experienced 'Thinking Science' activities in a CASE program. For this study, 71 9th grade students experienced in CASE program for 2 years were selected as the experimental group and 72 students were selected as the control group. All students were tested with Science Reasoning TaskVII. The five types of variable-controlling strategy were extracted from students' response. According to the result of this study, the students experienced in CASE program was more successful in the variable-controlling strategy of length, quality, and shape than the control group. The types of reasoning ability of the variable effect intuitively were categorized as possibility of reasoning, impossibility of reasoning, and impossibility of reversible thinking. It has shown that the reasoning ability of the experimental group was higher than that of the control group in the length and thickness variable effect. The results of this study implied that the variable controlling activities in CASE program could be effective for learning variable controlling, and eventually, for the development of reasoning ability of the variable controlling effect. In the ability to infer the effects of variables to get difficult Intuitively, both groups were similar to the rate of cognitive level reached to the formal operation in generalization, and the student of experimental group was 1.5 times faster than the control group.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1215-1221
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• 2016

The prediction of carcass composition in Hanwoo steers is very important for value-based marketing, and the improvement of prediction accuracy and precision can be achieved through the analyses of independent variables using a prediction equation with a sufficient dataset. The present study was conducted to develop a prediction equation for Hanwoo carcass composition for which data was collected from 7,907 Hanwoo steers raised at a private farm in Gangwon Province, South Korea, and slaughtered in the period between January 2009 and September 2014. Carcass traits such as carcass weight (CWT), back fat thickness (BFT), eye-muscle area (EMA), and marbling score (MAR) were used as independent variables for the development of a prediction equation for carcass composition, such as retail cut weight and percentage (RC, and %RC, respectively), trimmed fat weight and percentage (FAT, and %FAT, respectively), and separated bone weight and percentage (BONE, and %BONE), and its feasibility for practical use was evaluated using the estimated retail yield percentage (ELP) currently used in Korea. The equations were functions of all the variables, and the significance was estimated via stepwise regression analyses. Further, the model equations were verified by means of the residual standard deviation and the coefficient of determination ($R^2$) between the predicted and observed values. As the results of stepwise analyses, CWT was the most important single variable in the equation for RC and FAT, and BFT was the most important variable for the equation of %RC and %FAT. The precision and accuracy of three variable equation consisting CWT, BFT, and EMA were very similar to those of four variable equation that included all for independent variables (CWT, BFT, EMA, and MAR) in RC and FAT, while the three variable equations provided a more accurate prediction for %RC. Consequently, the three-variable equation might be more appropriate for practical use than the four-variable equation based on its easy and cost-effective measurement. However, a relatively high average difference for the ELP in absolute value implies a revision of the official equation may be required, although the current official equation for predicting RC with three variables is still valid.

• Journal of Mushroom
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• v.3 no.2
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• pp.71-74
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• 2005

The sterile form of Inonotus obliquus is used for preparation of the medicine befungin that is effective in the treatment of gastritis, gastric ulcers, and several tumors. The fungus is known to be produced mainly on the stems of Betula platyphylla var. japonica that grows at high altitudinal (above 1,100 m) region in Korea. But, we found the mushroom on the stem of Betula costata at Mt. Jumbong in Korea. We isolated a pure culture of the fungus from the stem of B. costata by use of potato dextrose agar (PDA) medium with streptomycin. We could isolate the fungus from plant's tissue filled with hyphae, but not from other parts. The spore collected from the sclerotia showed $6.0{\sim}10.0{\times}4.5{\sim}6.0{\mu}m$ in diameter, and the hypha was $2.5{\sim}5.0{\mu}m$ in thickness. The colony showed irregular features and scattered yellow color at the center as the culture ages. We could find brownish setae at the yellow region of colony at 20 days of culture, and the size ranged $4{\sim}6{\times}100{\sim}420{\mu}m$. The oatmeal agar (OA) provided best growth for I. obliquus among five media (CDA, CMA, MA, OA and PDA). Optimum temperature ranged $25{\sim}30^{\circ}C$, and optimum pH was relatively alkaline with the range of pH 8.0~9.5.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.6
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• pp.669-680
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• 2020

In Korea, fireproof performance is evaluated through a series of fire-resistance tests for important structures, and the performance standard follows the guidelines suggested by ITA. The fireproof duct slab manufactured by combining the slab and the fireproof material with a precast method is effective in that it can eliminate the construction time of the fireproof material. In this study, a series of fire resistance tests was performed on the fire test specimens under the RWS fire scenario in order to secure the fire resistance performance of the precast fireproof duct slab. As a result of the test, it was found that the fireproof performance was secured when the thickness of the fireproof material was 30 mm or more. In both fireproof materials and concrete, the rate of temperature change initially increased, then decreased, and then increased again, and the temperature at the inflection point was measured as 110℃ for all fireproof materials and concrete. It is judged that this occurs when the C-S-H (CaO-SiO₂-H₂O) generated by the hydration reaction in both the fireproof material and concrete is dehydrated.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1575-1580
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• 2018

Objective: This study was conducted to estimate the genetic parameters and breeding values of breast meat related traits of Pekin ducks. Selection response was also determined by using ultrasound breast muscle thickness (BMT) measurements in combination with bosom breadth (BB) and keel length (KL) values. Methods: The traits analyzed were breast meat weight (BMW), body weight (BW), breast meat percentage (BMP) and the three parameters of breast meat (BB, KL, and BMT). These measurements were derived from studying 15,781 Pekin ducks selected from 10 generations based on breast meat weight. Genetic parameters and breeding value were estimated for the analysis of the breeding process. Results: Estimated heritability of BMW and BMP were moderate (0.23 and 0.16, respectively), and heritability of BW was high (0.48). Other traits such as BB, KL, and BMT indicated moderate heritability ranging between 0.11 and 0.28. Significant phenotypic correlations of BMW with BW and BMP were discovered (p<0.05), and genetic correlations of BMW with BW and BMP were positive and high (0.83 and 0.66, respectively). It was noted that BMW had positive correlations with all the other traits. Generational average estimated breeding values of all traits increased substantially over the course of selection, which demonstrated that the ducks responded efficiently to increased breast meat yield after 10 generations of breeding. Conclusion: The results indicated that duck BMW had the potential to be increased through genetic selection with positive effects on BW and BMP. The ultrasound BMT, in combination with the measurement of BB and KL, is shown to be essential and effective in the process of high breast meat yield duck breeding.

• Restorative Dentistry and Endodontics
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• v.27 no.5
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• pp.535-542
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• 2002

The purpose of this study was to evaluate the effect of EDTA irrigant according to application time and temperature. 31 human mature extracted teeth with a single canal were sectioned with microtome in 3mm thickness and gained 62 samples of root canals. They were distributed randomly into 6 groups of 10 specimens each and control group of 2 specimens. Each specimen was prepared with GT rotary file (Dentsply, Maillefer Co., Swiss) and irrigated with 3 ml sodium hypochlorite every minute. Then smear layer was removed with EDTA solution (PULPDENT$^{\circledR}$, PULPDENT Co., USA.) except two control specimens. Specimens of each group were irrigated with 17% EDTA. The time and temperature of application were as follows : (Table omitted) All specimens were split longitudinally and prepared for examination by scanning electron microscopy. A set of reference micrographs was used to award a debris score as follows: 0 = no smear layer, all tubules clean and open; 1 = no superficial smear layer, tubule openings visible, but some contain debris plug or soft tissue remnants: 2 = moderate smear layer, some tubules open and others closed; 3 = heavy smear layer, most/all tubule openings obscured. Results were evaluated with Kruskal-Wallis test to determine whether there was statistically significant difference among six groups. Pairs of groups were analyzed using the Student-Newman-Keuls Method and Mann-Whitney test. The results were as follows : 1. Control specimens showed heavy smear layer at the canal walls 2. Among the groups applied with EDTA for 2 minutes, group 1 showed the heaviest smear layer, and there was statistically significant difference between group 1 and the other groups(p<0.05). 3. Among the groups applied with EDTA for 5 minutes, group 4 and group 6 showed smear layer but there was no significant difference between them. 4. Among the groups applied with EDTA for the same temperature, group 1 showed heavier smear layer than group 4, and there was statistically significant difference(p<0.05). 5. Among the groups applied with EDTA for the same temperature, group 2 showed heavier smear layer than group 5 and group 3 showed heavier smear layer than group 6. But there was no statistically significant difference among them. From the results above, it could be concluded, EDTA solution is effective in removing of smear layer when it is applied for 5 minutes. If EDTA is applied for 2 minutes, it should be applied above room temperature.

• The Journal of Pediatrics of Korean Medicine
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• v.24 no.1
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• pp.9-35
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• 2010

Objectives The purpose of this study is to investigate the effect of SPDJTK(SoPungDoJeokTangKami) and concurrent administration of AJ(Atopy cream, Jawoongo)+SPDJTK on atopic dermatitis-like skin lesions by using in NC/Nga atopic dermatitis mouse induced by BMAC-induced mice. Methods Clinical skin score, hematology and Serum total IgE and IgG1 of NC/Nga atopic dermatitis mice were evaluated. Moreover, the cytokine level, total cell number, Immunohistochemical staining and Histological features of axillary lymph node(ALN), draining lymph node(DLN), peripheral blood mononuclear cells(PBMCs) and dorsal skin tissue were used in NC/Nga mice. Results Orally administrated SPDJTK with concurrent administration of SPDJTK and AJ decreased the clinical skin score, total cell number of WBC, eosinophils in blood, serum total IgE & IgG1, IL-5, IL-13, IFN-$\gamma$. Also, total cell number of ALN and dorsal skin tissue, absolute cell number of CD4+, CD8+, CD3+CD69+, CD3+CCR3+, CCR3+, CD4+CXCR5+ in ALN, absolute cell number of CD3+CCR3+, CCR3+ in DLN, granulocytes in PBMCs, activation cell number of CD3+CD69+, CCR3+, total cell number of CD3+ T cell in dorsal skin tissue were significantly decreased. Furthermore, thickness of epidermis, infiltrated inflammatory immune cell and mast cell in dermis, amount of Eotaxin2 mRNA, CCR3 mRNA in dorsal skin tissue, gene expression of IL-5, IL-13 mRNA in ALN, CD4+ Th cell in dorsal skin tissue and CCR3+ eosinophils in ALN were all significantly decreased. However, total number of DLN, absolute number of CD3e+ T cell and CD19+ B cell, absolute number of CD4+, number of Th cell in DLN and gene expression of foxp3 mRNA were significantly increased significantly. Conclusions Concurrent administration of SPDJTK and AJ on atopic dermatitis in NC/Nga atopic dermatitis mouse was very effective treatment for atopic dermatitis.