• Polymer(Korea)
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• v.38 no.3
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• pp.406-410
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• 2014

Zinc ion containing thiuram type accelerator zinc dibutyldithiocarbamate (ZDBC) was compared to other thiuram type accelerators (tetramethylthiuram disulfide (TMTD) and dipentamethylenethiuram tetrasulfide (DPTT)) in silica filled natural rubber (NR) compound upon vulcanization and mechanical properties (modulus, tensile strength, and elongation %). ZDBC added compound showed the fastest cure time (t10) and the highest reinforcement index (R.I.) among them and showed a marching behavior. The mechanism was reviewed and a new mechanism was proposed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.410-420
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• 2016

Recently, the R&D paradigm has become oriented toward convergence technology and interdisciplinary research. In this study, to elucidate the characteristics of research groups that promote the performance of convergence research, we take into account the input characteristics, disciplinary characteristics and collaborative characteristics of research groups. For this study purpose, 5,217 SCI papers published from 104 centers in Advanced Research Center Projects are analyzed as research outputs. The research findings are that the disciplinary balance in the interdisciplinary characteristics and the number of partners in the collaborative characteristics are positively related to the convergence of R&D outputs. The research field of a group introduced as a control variable exerts a significant effect on the convergent R&D outputs. In conclusion, it is necessary to organize internally with the same number of each disciplinary researcher in a research group and to activate external collaboration with partners in order to produce more outputs of convergent research.

• Journal of the Korean Applied Science and Technology
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• v.24 no.4
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• pp.410-415
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• 2007

Functional cosmetics are intensively investigated for the effectiveness of skin whitening, anti-aging and slimming. For enhancing the effectiveness, active ingredients should be delivered into the cell in the dermis. The amounts of penetration of caffeine and $Arbutin^{(R)}$ were tested, in vitro, using Franz diffusion cell. Oil-in-water emulsions were used for the vehicles of the transport. For the measuring the amounts of active ingredients delivered into the dermal skin, tape stripping was done after finishing the penetration experiments. The amounts of delivered caffeine were $8.45{\pm}$ 1.26ug/ml before tape stripping and $3.45{\pm}$ 1.80ug/ml after tape stripping, however, the amounts of delivered $Arbutin^{(R)}$ was quite small to detect. From now on, proper vehicles are considered for enhancing the delivery of $Arbutin^{(R)}$ Hairless mouse skin was compared with pig skin as a transdermal delivery membrane. The aspects of delivery were similar, but the amount of delivered ingredients using pig skin was larger than that of using hairless mouse skin. Therefore, the pig skin would be considered as a membrane for drug delivery experiments.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.8
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• pp.571-579
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• 2011

Heat pump systems for commercial building with variable refrigerant flow(VRF) are expanding a market due to high energy efficiency, lower maintenance cost and easy installation comparing with the conventional heat pump with the constant refrigerant flow. In general, heat pump systems degrade the energy efficiency in the extremely low temperature regions. In this study, VRF heat pump system with refrigerant heating is experimentally investigated to overcome the low heating performance in the extremely low temperature regions. VRF heat pump system with refrigerant heating is found out the sufficient heating performance in the -25 degree temperature condition comparing with the conventional heat pump system and is obtained more than 2,500 kPa high pressure in the evaporator at low temperature.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.323-327
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• 2013

Various indicators representing skin characteristics such as skin hydration, sebum excretion rate, lightness, and pH are different depending on environmental and genetic factors. However, they are absolute skin indicators and are different from skin characteristics that a person recognizes. Based on this fact, many recent studies have been mainly conducting researches on perspective changes according to changes of absolute skin. This study was proposed not only to find out differences on skin colors of asian by nations, but also to find out whether there was any difference in skin brightness they perceive depending on actual skin color changing. As many as 410 subjects of three Asia nations were participated in this study, and investigated their responses on skin brightness using questionnaire, which was answered their skin color in three different levels. It was also were analyzed how actual skin brightness were changed depending on their perceived skin color changes of subjects. There was a trend showing that the brightness of the actual skin color was increased when participants felt their skin color got brighter regardless of their nationalities. However, there were some differences in color between perceived color and actual color. In addition, there was a different aspect by nations in changes of skin redness and skin yellowness. In conclusion, it was revealed that factors which help people to perceive their own skin brightness were not based on absolute skin brightness, but on different criteria depending on where they are from.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.410-424
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• 2021

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A bio-filter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM₁₀, PM_2.5, and CO₂ increased during rush hour according to the change in the number of passengers, and PM₁₀ and PM_2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM_2.5 in the subway station were the outdoor PM_2.5, platform PM_2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.152-159
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• 1990

Four active strains, producing siderophore and antagonizing to soil plant disease fungi, were isolated and identified from the wheat rhizosphere to reduce the injurious effects of continuous cropping and study on the biological control. The obtained results were summerized as follow. 1. Four strains of fluorescent Pseudomonas were isolated from the wheat rhizosphere and identified as Pseudomonas fluorescens Biotype A(Ps-1,2,5) and Biotype B(Ps-3) That strains inhibitied growth of R. solani, F.oxysperum and F. solani in vitro 2. Optical density of pigment was maximum at 410nm. 3. Siderophore production by identified strains was decreased with addition of $Fe^{+3}$, although not decreased with addition of $Fe^{+2}$ 4. Pigment of Ps-1, 2 and 3 strain inhibitied growth of R. slani, F. oxysperum and F. solani but pigment of Ps-5 strain did not inhibitie growth of R. solani 5. Effect of inoculation was in order of Ps-2, 1, 5 and 3 strain through the dark culture method, and effect of Ps-1 and Ps-2 was greater than that of treatment of captan 50ppm.

• Computers and Concrete
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• v.11 no.5
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• pp.399-410
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• 2013

A nonlinear finite element analysis of R/C hybrid deep T-beam with web opening subjected to pure torsion is presented. Hexahedral 8-nodes and space truss element were used for modeling concrete and reinforcement. The reinforcement was assumed perfectly bonded to the corresponding nodes of the concrete element. The constitutive relations for concrete and reinforcement are based on the modified field theory and elastic perfectly plastic. The smear crack approach was adopted for modeling the crack. The torque-twist angle relationship curve based on the finite element analysis was compared to the experimental results. The comparison shows that the curve of torque-twist angle predicted by the nonlinear finite element analysis is linear before cracking and close to the experimental result. After cracking, the curve becomes nonlinear and stiffer compared to the experimental result.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.261-267
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• 1999

Pot experiments were conducted to evaluate the phosphorus (P) availability with cropping in soils where P were highly accumulated. Bray 1-P contents of the used three soils were 584, 695 and $1043P\;mg\;kg^{-1}$, respectively. Corn ${\rightarrow}$ Chinese cabbage ${\rightarrow}$ Chinese cabbage ${\rightarrow}$ corn were sequentially grown from 1996 to 1998. P fertilizer was applied at three levels of 0 (P0), recommended application rate (P1), and double of recommended application rate (P2). At the end of each crop growth, available P content was determined by methods of Bray 1-P, Olsen-P and Lancaster-P. The growth of crops were not significantly affected by the rates of P applications. The relative yields of PO treatment were more than 88% of P1 treatment. The recoveries of added phosphorus were relatively low due to the high content of available phosphorus in soils. Although available phosphorus contents decreased through cropping, the concentration of soil available phosphorus was maintained high level even after the final cropping. In the case of P0 treatment in the three soils, the residual concentration was in the range of $410{\sim}610mg\;kg^{-1}$ for Bray 1-P, $284{\sim}410mg\;kg^{-1}$ for Olsen-P and $368{\sim}524mg\;kg^{-1}$ for Lancaster-P. The amount of soil available phosphorus decreased during the experiments was linearly regressed with high significance to the amount of P taken up by crops. The regressions of soil 1 as follow, Bray 1-P : y=149.7x=102.7, Lancaster-P : y=209.2x-140.2, Olsen-P: y=60.8x=19.9. The decrease rate of available phosphorus in the P0 treatment with cropping was described by an equation of first-order chemical reaction. The equation of soil1 was as follow: Bray 1-P: In(C)= -0.12N + 6.96 r=-0.991, Lancaster-P: In(C)= -0.14N = 6.88 r= -0.938, Olsen-P: In(C)= -0.07N = 6.37 r= -0.959. The rate constants seemed to be affected by ply, sand and silt content, and exchangeable $Ca^{2+}$ concentration. The times of cropping needed to reduce the content of available P to half of the initial or to the index level could be predicted by using that equation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.241-241
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• 2022

In the digital age, a lot of agricultural R&D is based on data. However, genetic resources are still essential for basic research and agricultural development. Accordingly, many countries are making great efforts to secure various genetic resources. In Korea, the National Agrobiodiversity Center (NAC) has more than 270,000 plant genetic resources so far as part of its efforts. In order to efficiently use the resources for agricultural R&D, it is essential to determine the genotypes of the resources. For this, it is essential to build a system for mass genotyping. For this, sorghum were selected as a model crop considering the genome size, the high-quality reference genome, and the number of resources. To efficiently determine the genotype data from many genetic resources, we developed a GATK pipeline that works efficiently on HPC. The pipeline efficiently and rapidly determined 769 genotypes of 410 genetic resources. Going forward, our team will continue to work to determine genotypes of over a thousand sorghum resources, and the data will be released at the National Agricultural Biotechnology Information Center (NABIC) in order to be used in agricultural R&D.