• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.9-18
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• 2016

This study was performed to understand wood durability to climate deterioration of planted Indonesian wood specie such as Albizia, Gmelina, Mangium and Mindi. Wood samples were exposed to indoor and outdoor condition. $L^*a^*b^*$ and Color changes (${\Delta}E*ab$) were determined by a spectrophotometer. As a result, color of all samples was changed more markedly by ultraviolet radiation. In indoor test with UV, brightness of wood specimens from four species was not changed and all samples were changed into more reddish and yellowish. In accelerated weathering test, all samples were bleached and changed into more greenish and blueish. In outdoor test, brightness of wood specimens decreased in Albizia and Gmelina and increased in Mangium and Mindi. All wood specimens in outdoor test were changed into more greenish and blueish. Albizia and Gmleina woods showed greater color change than those of Mangium and Mindi. Especially, color change of wood samples might be influenced greatly by moisture. In conclusion, wood color changed into more clearly by UV radiation. Therefore, exposing woods to UV radiation could be one of reasonable methods to improve wood quality on visual characteristic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.64-70
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• 2010

Soybean is of particular interest as a food supplement of isoflavones for inhibiting bone resorption in postmenopausal woman. These beneficial effects of isoflavones are caused by functioning as partial agonists or antagonists of estrogen, of which anti-resorptive effect is mediated indirectly through paracrine factors produced by osteoblasts that act on osteoclasts. In this study, the indirect effect of soybean on osteoclastic differentiation of RAW264.7 cells were investigated. The conditioned medium was collected from MC3T3-E1 osbeoblasts treated with 0.001 mg/mL~0.1 mg/mL soybean extracts for 6 days, mixed in 1:1 ratio with osteoclast medium, and then added into RAW264.7 cells with receptor activator of nuclear factor kappa B ligand (RANKL), a differentiation inducer for 3 days. Of paracrine factors in the conditioned medium, the protein expression of osteoprotegerin (OPG) with soybean extract was specifically higher in a dose dependent manner than with $10^{-9}$ M~$10^{-6}$ M of estrogen, genistein or daidzein standards. In RAW264.7 cells, the conditioned medium with soybean inhibited RANKL induced osteoclastic differentiation as total number of multinucleated tartrateresistant alkaline phosphatase (TRAP)-positive osteoclasts and protein expression of MMP-9 were significantly decreased. Coupled with the low expression of estrogen receptor $\alpha$ and $\beta$ proteins in RANKL treated RAW264.7 cells, we demonstrate that the conditioned medium of soybean treated osteoblasts inhibits RANKL induced differentiation of osteoclasts with the selective expression of OPG in osteoblasts.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.26-33
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• 2005

The study was carried out to provide information about growth and ecological characteristics by site types of natural deciduous forest in Pyeongchang, Gangwon Province. The data were collected from four aspects(the East, the West, the South, and the North) with three elevation(higher than 1.000 m, 700~1,000 m, lower than 700 m) and three topographical conditions(ridge, hill, and valley). Growth parameters by site types were evaluated based on the growth performances of dbh for the last 5 to 10 years; which were also estimated based on both Pressler and Schneider formulae. In addition, ecological characteristics such as Shannon-Wiener's diversity index, evenness index and richness index were analyzed by site types. The management methods by site types were suggested by considering stand density, growth patterns, and ecological characteristics. It was found that the stands on the South and the East are necessary the tending practices to improve growth and ecological characteristics. On the other hand, the West and the North needed the tending practices focusing on stand density management to increase growth rate rather than ecological management. It was also found that the area lower than 700 m in elevation showed Higher growth rate than other areas. As a management standard considered in terms of growth rate, it was suggested that tending practices should be applied to the stands of which growth rate for the last 5 to 10 years were lower than 2%. Considering topographical conditions, valley area showed better ecological characteristics than both ridge and hilly areas. Consequently, it was revealed that the valley areas were suitable for the ecological management.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.3
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• pp.263-270
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• 2024

In recent years, there has been an increasing amount of waste glass that cannot be recycled and is landfilled among construction and household waste. To address this issue, research has been conducted to recycle waste glass as sand, but conflicting results have emerged depending on the type of waste glass and the manufacturing method of recycled glass sand(RGS). To promote the use of RGS, it is necessary to review its performance under field conditions, such as mass production processes and real scale concrete applications. This study introduces examples of mass production system process for RGS and evaluates the effects of the usage conditions(color, content, particle size) of mass-produced RGS on the mechanical properties and alkali-silica reaction(ASR) of mortar. As a result, the mass production system process of RGS causes microcracks inside the particles, which are the cause of mortar strength reduction and ASR expansion. The number of microcracks is highest in clear RGS. Based on these results, it is proposed that RGS can be used as a replacement for natural sand with a content of less than 25 % or a particle size of less than 0.5 mm.

• Journal of the Korea Concrete Institute
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• v.15 no.4
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• pp.541-548
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• 2003

This study is to investigate the temperature curve and development of compressive strength due to the curing conditions and to evaluate the optimum curing condition of test specimens showing the same development of strength to that of real structures in cold weather. The results of temperature curve with curing conditions in mock-up tests showed the trend of decrease plain concrete with insulation form, plain concrete with heating, concrete with accelerator for freeze protection, and control concrete in turn. The strength development of plain concrete of inside and outside of shelter showed the very slow strength gains due to early freezing, but that of concrete with accelerator for freeze protection showed the gradual increase of strength with time. From this, it is clear that accelerator for freeze protection has the effects of reducing the freezing temperature and accelerating the hardening under low temperature. Strength test results of small specimens embedded in members and located in insulation boxes at the site are similar to that of cores drilled from the members at the same ages, thus it is clear that these curing methods are effective for evaluation in-place concrete strength.

• KSBB Journal
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• v.24 no.4
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• pp.334-340
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• 2009

For the isolation of a plant growth-promoting rhizobacteria, strain YK-5 was selected from approximately 400 thermostable strains isolated from special soil samples. Strain YK-5 produced an antifungal compound, and optimum carbon and nitrogen sources for the production of the antifungal compound were investigated against Aspergillus flavus as a test strain. Modified LB medium containing 1% peptone, 1% yeast extract and 5% black sugar was determined to be the optimal medium for growth and antifungal compound production. Culture broth of strain YK-5 potently inhibited growth of the phytopathogenic fungus Fusarium oxysporum KACC 40052 for 7 days. The plant growth-promotion function of strain YK-5 was tested against radish and rice in pot trials. Leaf number, plant height and root length in YK-5-treated radish markedly exceeded (> 60%) those of untreated radish. Leaf length and white rootlet development were markedly more prominent than in commercially-treated rice plants. Strain YK-5 was determined to be Bacillus subtilis YK-5 by physiological, chemotaxonomical, and phylogenetical analyses.

• Journal of Mushroom
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• v.21 no.3
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• pp.190-193
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• 2023

To cultivate pine mushroom (Tricholoma matsutake) artificially, co-cultivation with microorganisms has been introduced. Here, experiments were performed to assess the growth-promoting effect of bacteria on T. matsutake mycelia. Bacteria were isolated from soil samples collected in Yangyang County, Korea. Four of the bacterial isolates (Y22_B06, Y22_B11, Y22_B18, and Y22_B22) exhibited a growth-promoting effect on T. matsutake mycelia (154.67%, 125.91%, 134.06%, and 158.28%, respectively). To analyze the characteristics of the bacteria, especially the antifungal activity, 𝛼-amylase and cellulase activity assays were performed. In comparison with the controls, the isolated bacteria exhibited low 𝛼-amylase and cellulase activity. 16S rRNA gene sequencing was performed to identify the four bacterial isolates. The isolates belonged to the Terrabacteria group and were identified as Microbacterium paraoxydans, Paenibacillus castaneae, Peribacillus frigoritolerans, and P. butanolivorans. These bacterial isolates are expected to have contributed to the growth promotion of T. matsutake mycelia and the artificial cultivation of T. matsutake.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1452-1460
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• 2013

The purpose of this study was to investigate secondary drying effects on garlic quality, and to define the optimal secondary drying conditions for garlic preservation. The secondary drying tests used garlic that was naturally dried once and stored at low temperature. After secondary drying, the garlic was stored in a warehouse at room temperature. Tests were performed at different low-temperature storage periods (60, 105, 150, 195, and 240 days), secondary drying temperatures (35 and $40^{\circ}C$), drying times (1, 2, 3 days), and room temperature storage periods (15, 30, and 45 days). The results were compared with a non-secondary drying condition control. In general, the $40^{\circ}C$-2 days dry conditions showed the lowest weight-loss rate (5%) and rotting rate during room temperature storage. The sprouting rate increased by 20% during the initial 15 day-room temperature storage, along with a small increase after 30 days of room temperature storage. Increases in drying temperature and the period of secondary drying conditions caused a decrease in firmness. In addition, the sprouting rate was 10% higher, and rotting rate 5~10% higher, for the non-drying condition, compared to drying conditions. Based on our results, the $40^{\circ}C$-2 days drying condition is the optimal secondary drying condition for garlic storage.

• Journal of Power System Engineering
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• v.4 no.2
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• pp.31-39
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• 2000

Relationships between the plating condition and the plating rate of the deposition film for the electroless plating of Co-Cu-P alloy were discussed in this report. The result obtained from this experiment were summarized as follow ; The optimum bath composition was consisted of 0.8 ppm thiourea as a stabilizing agent. Composition of the deposit was found to be uniform after two hours of electroless plating. Plating rates of nickel-catalytic surface and zincate-catalytic surface were found to be very closely equal, but the plating time of nickel-catalytic surface took longer than that of the zincated-catalytic surface.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2014.10a
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• pp.5-19
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• 2014

최근 팀 다양성이 팀 창의성에 미치는 영향에 대한 연구가 주목을 받고 있으나 팀 다양성이 팀 창의성으로 발현되는 과정과 팀 다양성의 조건 하에서 팀 창의성이 촉진되는 조건에 대한 연구는 제한적으로 이뤄졌다. 국내 24개의 연구개발팀을 대상으로 조사한 결과, 팀 다양성, 특히 정보다양성이 팀 창의성에 긍정적인 영향을 주는 것을 증명하였다. 또한, 팀 구성원간 갈등은 팀 다양성과 창의성 사이에서 유의한 매개효과를 발휘하지 못하는 것을 확인하였다. 변혁적 리더십은 정보다양성과 직무 갈등 사이에서 부(-)의 조절효과를 보였다. 예컨대, 변혁적 리더십이 강하면 정보다양성이 높은 팀일수록 직무 갈등이 낮게 나타났다. 저자는 팀 다양성과 창의성 사이에서 갈등의 조절효과를 증명하기 위해서는 특히 동양권 국가에서 보다 면밀한 측정 방법이 요구되며 팀 다양성이 주는 가치(value in diversity)를 높일 수 있는 잠재적 매개변수의 탐색이 필요하다고 제안하였다.