• Journal of the Korea Concrete Institute
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• v.13 no.1
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• pp.54-61
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• 2001

As a part of the movement of natural resources conservation, there have been doing many recycling research works for obsolete aged tire, wasted plastic materials, etc. The purpose of this experimental study is to develop glass concrete by recycling wasted glasses as a cementitious constituent in concrete. First of all, the optimum replacement ratio of powdered waste glasses(PWG) can be determined through pilot compressive strength test on normal and high strength concrete cylinders, which have been made in various mix proportions by changing the replacement ratio of PWG. Then, further tests have been done to figure out mechanical properties of most desirable glass concrete with optimum replacement ratio of PWG, such as static modulus of elasticity, compressive and tensile strengths, flexural strength. On the other hand, the alkali-silica reactions by the mortar-bar method(KS F 2546) have been experimentally doing in various grain sizes of PWG, since the alkali in the cement has a tendency to react with the silica in the PWG. In can be confirmed from the test that glass concrete can have better workability than concrete with silica fume, and they are alike in compressive strength. It is concluded that wasted glasses can be used as pratical additives for economic and environmentally friendly concrete.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.58-66
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• 2006

The rice quality related traits including physico-chemical traits were evaluated with one hundred sixty-four MG RILs derived from the cross between Milyang 23, Indica/Japonica hybrid type, and Gihobyeo, Japonica type. The variation distribution of all traits examined approximately fit normal distribution and transgressive segregants over parents were observed for all traits. The occurrence of such transgression could be associated with the interactions of complementary QTL alleles from two parents. However in this study, it could not be concluded that our results of segregation were due to either complementary gene effects or overdominance of a major gene. These factors should be verified by further studies. Correlations between traits were evaluated by regressing phenotypic values of one trait on those of another traits. There are highly significant correlation between grain thickness with grain width, white core and white belly. But between white belly and alkali digestion value showed highly negative significant correlation. Contents of protein showed highly negative correlation with amylose and Mg/K ratio but showed highly correlation with K and Fat contents. Hardness of cooked rice showed highly correlation with adhesiveness, elasticity, gumminess, chewiness.

• International Journal of Concrete Structures and Materials
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• v.10 no.sup3
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• pp.97-108
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• 2016

When the energy performance of concrete is substantially higher than that of normal type concrete, such concrete is regarded as energy efficient concrete (WBSCSD 2009). An experimental study was conducted to investigate mechanical properties of energy efficient concrete with binary, ternary and quaternary admixture at different curing ages. Slump test for workability and air content test were performed on fresh concretes. Compressive strength, splitting tensile strength were made on hardened concrete specimens. The mechanical properties of concrete were compared with predicted values by ACI 363R-84 Code, NZS 3101-95 Code, CSA A23.3-94 Code, CEB-FIP Model, EN 1991, EC 2-02, AIJ Code, JSCE Code, and KCI Code. The use of silica fume increased the compressive strengths, splitting tensile strengths, modulus of elasticities and Poisson's ratios. On the other hand, the compressive strength and splitting tensile strength decreased with increasing fly ash.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.2
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• pp.67-75
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• 1982

A study on the effect of water reducing agent on the various characteristics of concrete has been conducted. The experimental results of the study are summarized as follows. 1. Slump test for the concrete added water reducing setretarding agent in proper quantity have been conducted. According to the test results, the decreasing rate of slump value become bigger than plain concrete with increase of the unit weight of cement and elapse of time 2. In case the proper quantity content of maximum compressive strength in Fig. 5 of water reducing set retarding agent is added, unit weight of water is decreased about 15% or so as compared with plain concrete. with the increase of water reducing set accelerating agent content unit weight of water is decreased much more, And other hand, amount of air entraining shows the increasing tendency with the increase of water reducing agent content. 3. The adding rate of water reducing agent which produce maximum strength shows that WR-CH and WR-SA which is water reducing set-starding agent is 0.2% and WR-CO is 0.5% and that WS-PO which is water reducing set accelerating agent is 0.5 4. compressive strength jof the concrete made of sulfate resistant cement shows less than the strength of normal portland cement at initial strength but the strength of both cement shows almost same at curing age of 28 days. 5. when proper quantity of water reducing set retarding agent is used, boned strength is increased about 15% at curing age of 28days. 6. According to the result of durability test, dynamic young's mudulus of elasticity at plain concrete is decreased about 50% as compared with initial step at 300 cycle of freezing and thawing after curing age of days. on the contarary the concrete used water reducing agent is decreased less than 7%.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.689-692
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• 2008

HSC(High Strength Concrete) have superior properties well as improvement in durability compared with normal strength concrete. In spite of durability of HSC, explosive spalling of concrete is serious problem in structure safety. Therefore, Solving methods are required to control the explosive spalling. The properties of concrete are affected by changes of temperatures. Compressive strength and elasticity modulus were degraded depending on a rise of temperatures. Also, change in microstructure and dehydration of concrete subjected to high temperatures. This paper is concerned with change in microstructure and dehydration of the alumino silicate fire protection materials at high temperatures. The testing methods of fire protection materials in high temperature properties are make use of SEM, TG-DSC and XRD. From the experimental test results, influence of high temperatures on microstructure of alumino-silicate fire protection material was identified, including chemical dehydration of C-S-H and CH. The chemical dehydration of CH under various temperatures from to 450 to 600$^{\circ}$C has been measured using the TG-DSC. However, developed alumino silicate fire protection materials showed good stability in high Temperatures. Thus, the results indicate that it is possible to fireproof panels, fire protection of materials.

• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.249-256
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• 2002

High performance concrete is prone to large autogenous shrinkage due to its low water to binder ratio (W/B). The autogenous shrinkage of concrete is caused by self-desiccation as a result of water consumption by the hydration of cement. In this study, the autogenous shrinkage of high performance concrete with and without fly ash was Investigated. The properties of fresh concrete, slump loss, air content, and flowability as well as the mechanical properties, compressive strength and modulus of elasticity, were also measured. Test results was shown that the autogenous shrinkage of concrete increased as the W/B decreased. For the same W/B, the autogenous shrinkage of high strength concrete with fly ash was considerably reduced although the development of its compressive strength was delayed at early ages. Furthermore, the autogenous shrinkage and compressive strength of high strength concrete were more rapidly developed than those of normal strength concrete. It was concluded that fly ash could improve the quality of high strength concrete with respect to the workability and autogenous shrinkage.

• Archives of Reconstructive Microsurgery
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• v.19 no.1
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• pp.46-49
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• 2010

Purpose: It has been reported that the ear perfusion can maintain by a very small pedicle because the ear has good vascularized system. Replantation of an amputated ear with vascular anastmosis, has been reported before and offers the succeessful reconstructive results. But, in this paper we report a case of complete nonmicrosurgical salvage of a nearly amputated ear based on 7 mm-wide small skin pedicle with adjunctive therapies. Methods: A 49-year-old man was referred with a nearly complete detachment of left ear. The blood supply to the ear was maintained exclusively on 7 mm-wide small skin pedicle in the lobule. After we identified the fresh bleeding at the distal margin of the detached ear, we performed the primary repair. At the end of the procedure, the areas of the concha bowl and helical root appeared to be congested. So the immediate postoperative treatment for improving the tissue survival was done with Lipo-Prostaglandin E1 (Eglandin$^{(R)}$) injection, leech apply and antibiotics medications. Results: Assessment of the replanted ear on postoperative day 14 revealed a nearly viable auricle including the helical root. The ear appeared to be entirely healed, with excellent projection and fully restored normal elasticity. Conclusion: We found the complete salvage of a nearly amputated ear based on 7 mm-wide small skin pedicle with adjunctive therapies including Lipo-Prostaglandin E1 (Eglandin$^{(R)}$) injection, leech apply and antibiotics without microsurgery.

• Nutrition Research and Practice
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• v.8 no.4
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• pp.398-403
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• 2014

BACKGROUND/OBJECTIVES: Ultraviolet B (UVB) irradiation on skin can induce production of reactive oxygen species (ROS), which cause expression of matrix metalloproteinases (MMPs) and collagen degradation. Thus, chronic exposure of skin to UVB irradiation leads to histological changes consistent with aging, such as wrinkling, abnormal pigmentation, and loss of elasticity. We investigated the protective effect of the standardized green tea seed extract (GSE) on UVB-induced skin photoaging in hairless mice. MATERIALS/METHODS: Skin photoaging was induced by UVB irradiation on the back of Skh-1 hairless mice three times per week and UVB irradiation was performed for 10 weeks. Mice were divided into six groups; normal control, UVB irradiated control group, positive control (UVB + dietary supplement of vitamin C 100 mg/kg), GSE 10 mg/kg (UVB + dietary supplement of GSE 10 mg/kg), GSE 100 mg/kg (UVB + dietary supplement of GSE 100 mg/kg), and GSE 200 mg/kg (UVB + dietary supplement of GSE 200 mg/kg). RESULTS: The dietary supplement GSE attenuated UVB irradiation-induced wrinkle formation and the decrease in density of dermal collagen fiber. In addition, results of the antioxidant analysis showed that GSE induced a significant increase in antioxidant enzyme activity compared with the UVB irradiation control group. Dietary supplementation with GSE 200 mg/kg resulted in a significant decrease in expression of MMP-1, MMP-3, and MMP-9 and an increase in expression of TIMP and type-1 collagen. CONCLUSIONS: Findings of this study suggest that dietary supplement GSE could be useful in attenuation of UVB irradiation-induced skin photoaging and wrinkle formation due to regulation of antioxidant defense systems and MMPs expression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.16-21
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• 2014

Micro needle roller therapy has been used for cosmetic purposes, such as reducing skin winkles and improving elasticity of skin. It is claimed that micro needle roller therapy has potentials for connective tissue regeneration by facilitating collagen synthesis. Therefore, there seems to be a possibility that connective tissue regenerating potential of micro needle roller therapy could influence the hair growth cycle. This study, we investigated the hair growth-promoting effects of micro needle roller therapy. C57BL/6 mice were devided into three groups as follows: normal saline-treated, minoxidil-treated, and micro needle roller therapy-received group. Hair growth activity was evaluated by handscopic and microscopic observations. Sections of dorsal skin were stained with hematoxylin and eosin. Expression of BrdU, FGF, and VEGF was detected by immunohistochemical staining. Micro needle roller therapy enhanced the development of hair follicle during anagen. Immunohistochemical analysis revealed that micro neeld roller therapy incresed the expression of BrdU and FGF in the hair follicles of C57BL/6 mice. Furthermore, micro needle roller therapy upregulated mRNA expression of VEGFR-2, FGF-2, EGF - growth factors that play a central role in hair follicle development during anagen. These results suggest that Micro needle roller therapy can potentially be used for the treatment of alopecia.

• The Journal of Fisheries Business Administration
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• v.41 no.3
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• pp.59-78
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• 2010

This paper tries to apply the asymmetrical price transmission(APT) behavior observed in the agricultural industry to supply chains of the domestic fishery industry by a statistical manner. The fore mentioned asymmetrical price transmission refers to when price movements in the later stage of the supply chain do not move in a normal or symmetrical manner corresponding to price movements in the earlier stage of the supply chain. Therefore, when the earlier stage price increase and the later stage price increases to a larger degree, it is called positive(+) asymmetry and the opposite behavior is called negative(-) asymmetry. The study examines the data from domestic producers of three fresh fish types, hairtail, mackerel, and cuttlefish, and tries to examine the price asymmetry between the producer or farm, wholesaler, and retail prices via an APT test utilizing unit root, cointegration, and error correction model. The study found, hairtail wholesale and retail pricing bas a negative asymmetric relationship while mackerel has a negative asymmetric pricing relationship at the producer and retail levels of the supply chain. In the case of cuttlefish, all levels of the supply chain showed negative asymmetrical behavior in the supply chain price transmission, meaning the earlier stage price changes are more rapidly and greatly inputted in the later stage of the supply chain pricing. We believe that the reason why the analysis results show negative price asymmetry is due to the uniqueness of fishery products having an important variable such as freshness. If price increases are greater and quicker than price decreases, then consumer demand, which is sensitive to price increases will decrease and subsequently result in the increase of inventory levels, reducing profits for retailers. Also, frozen hairtail, mackerel, and cuttlefish will act as substitute goods to fresh fishery products. Therefore, fresh fishery products have a high demand of price elasticity. When prices increase, demand quickly decreases. Therefore the profit of wholesalers and retailers to decrease, I think this is the main reason of APT in the supply chain of Korea' s fisheries industry.