• Textile Coloration and Finishing
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• v.11 no.2
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• pp.27-37
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• 1999

Polypropylene(PP) films were treated with plasma glow discharge to produce peroxy radicals on the surfaces. The peroxy radicals formed on the PP film surfaces were subsequently used for the graft polymerization of acrylic acid and acrylamide in an aqueous solution by heating, respectively. Introduction of acrylic acid and acrylamide on the PP film could be confirmed by the observation of carbonyl and primary amine absorptions based on carboxylic acid and amide, respectively. And introduction of functional group could be confirmed by weight analysis and ESCA. The water contact angle(90$^{\circ}$) of PP film was constant, irrespective of elapsed time, while plasma-treated and functional monomer-grafted PP films were slowly increased with elapsed time, showing the rearrangement of surface polar groups in air condition. The water contact angle$(90^\circ)$ of PP film was decreased by the plasma treatment$(56^\circ)$ and further decreased by the grafting of acrylic acid$(34^\circ)$ and acrylamide$(37^\circ)$, indicating increased hydrophilicity of the modified surfaces. The water contact angle of plasma-treated PP film increased a little as time elapsing. The half-life periods of surface voltage on acrylic acid-(31sec) and acrylamide-grafted PP(42sec) were significantly decreased when compared to those on PP(950sec) and plasma-treated PP film(241sec). In the experiments using acid, basic and disperse dyes, absorbance and $\Delta{E}$ values of functional monomer-grafted PP films were significantly increased than that of oxygen plasma-treated one.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.3
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• pp.37-49
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• 1998

Research and a, pp.ication of earthquake protection system in Taiwan have become very active since about ten years ago. Many passive isolators, etc., have been studied extensively. These studies have resulted in a few practical a, pp.ications and proposals of two draft design provisions for seismic isolation design of bridges and buildings. In addition to the pass control, analytical studies on active semi-active control have also been very active and the experimental studies have scheduled in the near future. This paper summarise the progress on recent research and a, pp.ication of earthquake protection systems in Taiwan. The emphases are given to the control systems that have been a, pp.ied in practical a, pp.ications.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.62-66
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• 1984

One row of pollen parent to two rows of seed parent (1:2), 2:4 and solid (1:2) planting patterns (PP) were compared in seed parent densities of 3,500, 5,000 and 6,500 plants per 10 ares to determine effects of PP and plant density on growths of seed and pollen plants, and seed yield of seed parent of modified single cross corn hybrid. Planting pattern did not significantly affect agronomic characteristics of seed plant except ear number per 100 plants and seed yield which were greater in solid and 1:2 PP than in 2:4 PP. Significant PP x plant density interaction did not exist for agronomic characteristics of seed parent. In the seed parent, plant height and 100 kernel weight were not affected by plant density, but ear height, ear number per 100 plants, and kernel number per ear were linearly decreased with increased plant densities. Seed yield ranged from 330 to 460 kg per 10 ares and overall yield response to plant density was quadratic. Tassel length and spikelet number per tassel of the pollen parent were significantly affected by PP and plant density. Significant PP x plant density interaction existed for tassel length and spikelet number per tassel. Tassel length and spikelet number per tassel were greater in 1:2 and 2:4 PP compared to solid PP and were greatly reduced with increased plant densities in solid and 1:2 PP. The results indicated that 1:2 or 2:4 PP at around 5,000 plants per 10 ares for seed parent would be suitable for seed production of modified single cross com hybrid.

• Journal of Public Diplomacy
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• v.2 no.1
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• pp.136-142
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• 2022

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.4
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• pp.211-215
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• 2003

To examine the localization pattern of phospholipase D2 (PLD2) in the pancreatic islet (the islet of Langerhans) depending on species, we conducted a morphological experiment in the rat and guinea pig. Since individual islets display a typical topography with a central core of B cell mass and a peripheral boundary of A, D, and PP cells, double immunofluorescent staining with a panel of antibodies was performed to identify PLD2-immunoreactive cells in the islets PLD2 immunoreactivity was mainly present in A and PP cells of the rat pancreatic islets. And yet, in the guinea pig, PLD2 immunoreactivity was exclusively localized in A cells, and not in PP cells. These findings suggest a possibility that PLD2 is mainly located in A cells of rodent pancreatic islets, and that the existence of PLD2 in PP cells is not universal in all species. Based on these results, it is suggested that PLD2 may play a significant role in the function of A and/or PP cells via a PLD-mediated signaling pathway.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.303-314
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• 2021

With the high quality/high stiffness/high strength of segment lining, segment lining is increasingly used as the final lining of the tunnel. Precast concrete lining has higher quality and strength than field concrete. Paradoxically, this contributes to greater damage to concrete in the event of a fire in a tunnel. In this study, tests were conducted to determine the fire resistance performance of segment linings according to fiber content in fire resistance methods using synthetic fibers such as PP fibers. As a result, it was confirmed that fire resistance performance required by the relevant project can be secured when using 1.5 kg/m³ of PP fiber. In addition, comparison of the results of PP fibers with PET, a similar synthetic fiber, showed better fire resistance performance than when PP fibers were used.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.3
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• pp.433-452
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• 2019

This study deals with shotcrete reinforcing performance according to the amount of synthetic fiber (PP fiber) and proper evaluation method. The shotcrete compressive strength, flexural strength and flexural toughness were tested by setting the mixing amounts of steel fiber ($37.0kg/m^3$) and synthetic fiber (PP fiber) as parameters ($5.0kg/m^3$, $7.0kg/m^3$ and $9.0kg/m^3$). Particularly, circular panel flexural toughness test (Road and Traffic Authority, RTA) was performed to evaluate the shotcrete energy absorption capacity. As a result, the compressive strength and the bending strength of the steel fiber reinforced shotcrete were large, but the flexural toughness of the synthetic fibe (PP fiber) reinforced shotcrete was large. Therefore, synthetic fiber (PP fiber) reinforced shotcrete is considered to have a reinforcing effect comparable to that of steel fiber reinforced shotcrete. Analysis of the relationship between the flexural toughness and the energy absorption capacity of synthetic fiber (PP fiber) reinforced shotcrete revealed that the energy absorbing ability is exhibited at a flexural toughness lower than the allowable standard (3.0 MPa). (Class A: 2.55 MPa = 202J, Class B: 2.72 MPa = 282J, Class C: 3.07 MPa = 403J). As a result of this study, it can be concluded that the actual shotcrete support performance can be evaluated by evaluating the support performance of the shotcrete measured at less than the allowable standard (3.0 MPa) at the actual tunnel site.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.33-40
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• 2011

Ionizing radiation can be used to improve the color of green tea extract to brighter. As a result, the irradiated green tea extract can be applied easier and broader in food or cosmetic industry. To confirm the retention of the biological activities of the cosmetic products added with green tea polyphenols (PPs), the real cosmetic products including a skin lotion (PS) and an essence (PE) cream were manufactured. Irradiation also applied to the manufactured cosmetic products to see their improvement of color and changes of biological activity. The PP showed 72% of electron donating ability (EDA) at a 5 ppm concentration and the PS and PE containing 2% PP showed higher than 60%, which was similar inhibition activity to vitamin C. The inhibition of superoxide dismutase (SOD)-like activity of PP, PS, and PE were higher than 55% at a 500 ppm concentration and the inhibition of xanthine oxidase (XOase) were also higher than 65% at a 200 ppm concentration. The measurement of lipid oxidation by addition of $Cu^{2+}$ and $Fe^{2+}$ as prooxidants showed that PP and PS had higher metal chelating ability for $Fe^{2+}$ than that of PE and the ability increased by increase of polyphenol concentration isolated from green tea. The $Cu^{2+}$ chelating ability of PP and PS showed higher than 90% at a 200 ppm concentration. Therefore, it is concluded that addition of PP in manufacturing PS and PE retains its biological activities including EDA, inhibition of XOase and SOD-like activity, and metal chelating ability in the manufactured cosmetic products. In addition, irradiation of PS and PE improved color of the products containing PP brighter without any adverse changes in biological activity of the products.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.530-533
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• 1998

In this paper, a new scheme of a boosted voltage generator (BVG) is designed for low powr DRAM's. The designed BVG can supply stable $V_{pp}$ using a new circuit operting method. This method controls charge pumping capability by switching the supply voltage and ring oscillator frequency of driving circuit, so the BVG can save area and reduce the powr dissipation during $V_{pp}$ maintaining period. The charge pumping circuit of the BVG suffers no $V_{T}$ loss and is to be applicable to low-voltage DRAM's. $V_{pp}$ level detecting circuit can detect constant value of $V_{pp}$ against temperature variation. The level of $V_{pp}$ varies -0.55%~0.098% during its maintaining period. Charge pumping circuit can make $V_{pp}$ level up to 2.95V with $V_{cc}$ =1.5V. The degecting level of $V_{pp}$ level detecting circuit changes -0.34% ~ 0.01% as temperature varies from -20 to 80.deg. C. The powr dissipation during V.$_{pp}$ maintaining period is 4.1mW.W.1mW.

• ALGAE
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• v.37 no.4
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• pp.265-279
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• 2022

The primary production (PP) by phytoplankton in marine ecosystems is essential for carbon cycling and fueling food webs. Hence, estimating the PP in the territorial sea of each country is a necessary step to achieving carbon neutrality. To estimate the PP in the territorial sea of the Republic of Korea from 2005 to 2021, we analyzed various physiochemical parameters, such as sea surface temperature (SST), Secchi depth, and concentrations of chlorophyll-a and nutrients in the seas of five regions, including the East Sea, West Sea, western South Sea, eastern South Sea, and the waters off Jeju Island. During the 17-year study period, the SST tended to increase, while the nutrient concentrations declined, except in the Jeju area. Overall, the PP did not show a specific temporal trend, but daily PP in the western South Sea was the highest among the five regions. Moreover, the maximum PP in the Korean territorial waters (76,450 km²) was estimated at 11,227 Gg C y^-1, which accounts for 0.03% of the global PP. The results may give insights into a better understanding of the PP, further resource utilization, and environmental sustainability in the studied region.