• Corrosion Science and Technology
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• v.7 no.1
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• pp.50-60
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• 2008

The majority of the described experimental results deal with relatively pure aluminium. Variations were made in the pretreatment of the aluminum substrates and an investigation was performed on the resulting changes in oxide layer composition and chemistry. Subsequently, the bonding behavior of the surfaces was investigated by using model adhesion molecules. These molecules were chosen to represent the bonding functionality of an organic polymer. They were applied onto the pretreated surfaces as a monolayer and the bonding behavior was studied using infrared reflection absorption spectroscopy. A direct and clear relation was found between the hydroxyl fraction on the oxide surfaces and the amount of molecules that subsequently bonded to the surface. Moreover, it was found that most bonds between the oxide surface and organic functional groups are not stable in the presence of water. The best performance was obtained using molecules, which are capable of chemisorption with the oxide surface. Finally, it was found that freshly prepared relatively pure aluminum substrates, which are left in air, rapidly lose their bonding capacity towards organic functional groups. This can be attributed to the adsorption of contamination and water to the oxide surface. In addition the adhesion of a typical epoxy-coated aluminum system was investigated during exposure to water at different temperatures. The coating was found to quite rapidly lose its adhesion upon exposure to water. This rapid loss of adhesion corresponds well with the data where it was demonstrated that the studied epoxy coating only bonds through physisorptive hydrogen bonding, these bonds not being stable in the presence of water. After the initial loss the adhesion of the coating was however found to recover again and even exceeded the adhesion prior to exposure. The improvement could be ascribed to the growth of a thin oxyhydroxide layer on the aluminum substrate, which forms a new, water-stable and stronger bond with the epoxy coating. Two routes for improvement of adhesion are finally decribed including an interphasial polymeric thin layer and a treatment in boiling water of the substrate before coating takes place. The adhesion properties were finely also studied as a function of the Mg content of the alloys. It was shown that an enrichment of Mg in the oxide could take place when Mg containing alloys are heat-treated. It is expected that for these alloys the (hydr)oxide fraction also depends on the pre-treatment and on the distribution of magnesium as compared to the aluminium hydroxides, with a direct impact on adhesive properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.288-293
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• 2008

In this study, we investigated the anticancer activity of Makgeoly (MG). MG was fractionated into four fractions by using solvent partition method, affording hexane (MGH), methanol (MGM), butanol (MGB) and aquous (MGA) soluble fractions. We determined the cytotoxicity of these four fractions in four kinds of cancer cell lines, such as HepG2, MCF-7, B16-F10 and HT29 by MTT assay. Among the various fractions, the MGM showed the strongest cytotoxic effects on all cancer cell lines. The morphological changes such as membrane shrinking and blebbing of cells were also observed by MGM treatment in HepG2 cell. In addition, we observed quinone reductase (QR) activity stimulating effects in all fraction layers of MG on HepG2 cells. QR activity increased approximately 2.6 and 2.1 times in MGM and MGH treated HepG2 cell at $100{\mu}g/mL$, respectively, compared to that in control value. Although further studies are needed, the present work could suggest that the fin of MG has a potential to be used as a chemopreventive agent against cancer.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.199-204
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• 2014

We conducted a short-term incubation experiment in order to understand the effect of the salinity of reclaimed coastal soils on nitrogen mineralization of livestock manure compost (LMC). Two soils with the same soil texture but different EC levels were collected from the same field. These samples were treated with 0%, 1%, 2%, and 3% of LMC by weight basis and incubated at $25^{\circ}C$ to observe changes in inorganic N contents, pH, and dehydrogenase activity with respect to time. As a result, regardless of the soil EC level, as the LMC increased, the total content of the inorganic N ($NH_4{^+}+NO_3{^-}$) increased. Difference in the soil EC level did not affect N mineralization of LMC greatly. The soil EC had negligible effect on the dehydrgenase activity as with the case of inorganic nitrogen. The $NH_4{^+}$ contents remained very low throughout the experimental period starting from the first week of incubation. We believe this is due to the high pH level (pH 7.9 and pH 8.3) of the original soils leading to ammonia volatilization. On the other hand the $NO_3{^-}$ content maintained high level as the LMC treatment level increased and reached maximum at the third week. The pH of the soil during incubation period decreased as the $NO_3{^-}$ contents increased and increased slightly after three weeks. The rise of pH level is believed to be from the $NO_3{^-}$ absorption for immobilization by microbes. In conclusion, the high soil $EC_{1:5}$ level of $12dS\;m^{-1}$ conducted in this experiment did not affect the growth in terms of soil microbes involved in N mineralization of LMC.

• Journal of Korea Port Economic Association
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• v.34 no.2
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• pp.97-114
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• 2018

The East Asian region, an important part of Korea's imports and exports, is expected to grow further driven by the geographical, political, economic, social, and cultural complementarity. With the recent increase in imports and exports, the port trade volume between Korea and East Asian countries is also growing. However, due to various factors, such as economic size, growth rate, port infrastructure level, and geographical location of these countries, the volume of traffic with these ports is fluctuating. Despite much research on the volatility of port trade volume and changes in port network, this study tries to supplement the gap in a more detailed study of ports in Korea and East Asia since these kinds of studies are limited. The purpose of this study is to analyze the trend of distribution routes of export container cargo among ports in Korea and to present policy and practical implications of Korean trading companies, shipping companies, logistics companies, and port authorities. This study analyzes the variability of the trade volume between Korea's major ports and Daedong. Results show that Shanghai, Ningbo, Ho Chi Minh, and Haiphong were the most important factors in terms of size and volume increase. In terms of ports, the Busan port is the port responsible for trades with Yantai, Weihai, Hakata, Kobe, Ho Chi Minh, and Haiphong; Incheon port deals with Lianyungang, Tianjin, Osaka, Kobe, Ho Chi Minh, Haiphong; Gwangyang port trades with Tianjinxingang, Weihai, Yokohama, Mihn and Tanjong, and Ulsan port is strategically important for the Yantai, Lianyungang, Nagoya, Kobe, Ho Chi Minh and Portkelang ports. Therefore, the Korean government, port authorities, and shipping and logistics companies need to strengthen logistic network cooperation with these ports and actively promote investments in them.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.129-136
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• 2009

This study was to optimize the harvest time of several winter cereal forage crops. Barley, rye, oat, triticale and wheat were evaluated for the quantity and quality of hay and silage at four different harvesting stages, including heading, 10 days after heading (DAH), 20 DAH and 30 DAH. Barley and wheat harvested at 20 DAH, and oat and triticale at 30 DAH showed maximum dry matter yield. Crude protein content of barley, wheat, triticale and oat decreased significantly with advancing crop maturity. Mean crude protein content was the highest in rye and the lowest in oat. The NDF and ADF content of barley, wheat, triticale and oat decreased with late harvest, while rye increased. Maximum total digestible nutrients (TDN) content was recorded in barley and wheat harvested at 20 DAH, in triticale and oat at 30 DAH, and in rye at heading. The maximum TDN content of silage, 66.98%, was recorded in barley, followed by wheat, triticale, oat and rye. However, The crude protein, NDF and ADF of silage was 1 to 4 times higher than those of hay. In this study, barley harvested at 20-25 DAH, wheat and triticale at 30 DAH, and rye at heading provided a good compromise between dry matter yield and forage quality. At this stage, a sufficient quantity of fodder with moderate forage quality was obtained.

• Applied Microscopy
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• v.34 no.2
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• pp.145-157
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• 2004

The aim of the present study was to examine in detail, both at light and electron microscopical levels, the morphological variations in ameloblast of the fetal rat incisor enamel organ. Rats were started on distilled water at the beginning of pregnancy. The pups were sacrificed 11 days after delivery and animals were perfused intravascularly with glutaraldehyde and the incisors were removed. To examine on the ultrastructure of the ameloblast, the study employed primary light microscopy but electron microscopy was used to clarify some of the light microscopic finding. Longitudinal sections through the incisors of the rat show a continuous layer of ameloblasts on the labial surface of the tooth. This layer contains the entire sequence of developmental stages in enamel production. The ameloblast layer was divided into three main zones: 1) Presecretory zone, region of ameloblasts facing pulp. 2) Secretory zone, region of inner and outer enamel secretion. 3) Maturation zone, region of reduced ameloblasts. In particularly, the present study has shown that two distinctively different types of ameloblasts appear in the enamel organ during enamel maturation in the rat incisor. These two types have been designated ruffle-ended ameloblasts (rAB) and smooth-ended ameloblasts (sAB). The fluoride produces marked alteration in the fine structure of ameloblast from teeth of young rats, such as large confluent distensions of the endoplasmic reticulum and swelling of isolated mitochondria. This experimental data suggested that exposure prolonged of animal to high level of fluoride appears to induce a few dramatic changes in the normal appositional growth and initial mineralization of enamel created during amelogenesis.

• Journal of Animal Science and Technology
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• v.57 no.8
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• pp.28.1-28.7
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• 2015

Background: The physiologic characteristics of the cashmere trait and many of the differentially expressed genes relevant to hair cycling have been extensively studied, whereas genes involved in the prenatal development of hair follicles have been poorly investigated in cashmere goats. The aim of this study, therefore, was to quantify the time-course changes in the expressions of $TR{\alpha}$ and CRABPII genes in the fetal skin of Chinese cashmere goats at the multiple embryonic days (E70, E75, E80, E90, E100, E120 and E130) using real-time quantitative PCR (RT-qPCR). Results: RT-qPCR showed that $TR{\alpha}$ was expressed at E70 with relatively high level and then slightly decreased (E75, E80, and E90). The highest expression of $TR{\alpha}$ mRNA was revealed at E130 (P > 0.05). The expression pattern of CRABPII mRNA showed an 'up-down-up' trend, which revealed a significantly highest expression at E75 (P < 0.05) and was down-regulated during E80 to E120 (P < 0.05) and mildly increased at E130, subsequently. Conclusion: This study demonstrated that $TR{\alpha}$ and CRABPII genes expressed in different levels during prenatal development of cashmere. The present study will be helpful to provide the comprehensive understanding of $TR{\alpha}$ and CRABPII genes expressions during cashmere formation and lay the ground for further studies on their roles in regulation of cashmere growth in goats.

• Journal of Environmental Science International
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• v.28 no.11
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• pp.907-915
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• 2019

This study aims to identify the most tolerant species under salinity stress from amongst Asteraceae and Poaceae. The seeds of six species were exposed to different concentrations of $CaCl_2$ (0, 9, 18, 45, 90 mM) and NaCl (0, 17, 34, 85, 170 mM), and germination was measured once every two days. The results indicated that percent germination of the six species of Asteraceae and Poaceae seeds were affected differently by changes in salinity concentration. Seed germination was reduced as salinity levels increase, and longer mean germination times correlated to lower percent germination and earlier germination cessation. Both Asteraceae and Poaceae seeds had the highest germination rates at 18 mM $CaCl_2$ and 34 mM NaCl, and seed germination and growth were severely reduced at salinities greater than 90 mM $CaCl_2$ and 170 mM NaCl. In the seeds of Poaceae, salt resistance was strong in the order of Miscanthus sinensis Andersson, Pennisetum alopecuroides (L.) Spreng., and Phragmites communis Trin. In the seeds of Asteraceae, salt resistance was strong in the order of Dendranthema zawadskii var. latilobum (Maxim.) Kitam, Aster yomena (Kitam.) Honda, and Dendranthema boreale (Makino) Ling ex Kitam.. Overall, the germination rate was higher in Asteraceae than in Poaceae. This study demonstrated that Dendranthema zawadskii var. latilobum (Maxim.) Kitam. is the most tolerant species and that a relationship exists between the salt tolerance of percent germination and the mean germination time in the leaves.

• Journal of Korea Port Economic Association
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• v.25 no.2
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• pp.129-148
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• 2009

In 2006, the share of fisheries distribution in Busan amounted to 1.9 million ton, which was 41 percent of the whole country. In details, coastal fishery 334 thousand ton(14% of the whole country), deep sea fishery 452 thousand ton(82%), import fishery 964 thousand ton(70%), export fishery 157 thousand ton(43%) were distributed in Busan region, respectively. Recently, the share of fisheries sale through e-commerce is increasing owing to the growth of IT and competitive price of its products. and the sale share of large discount store is also on the 10% more increase owing to the effectiveness of distribution structure. Hereafter these structure changes of fisheries distribution in Busan will be more intensified. Therefore, after reflecting the change in distribution policy of Busan Fisheries, the directions of distribution policy should be established, as follows. Distribution policy to prepare for increasing of sales ratio in large discount store

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.228-236
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• 2019

This study investigated the effect of the sediment phosphorus fraction sampled from the southern coast of Korea on the release characteristics of sediments by environmental changes of water quality. We conducted the release experiment in the laboratory for 20 days and measured the phosphorus fraction properties, the environmental factors of water quality, and the release rate of total phosphorus. The results showed a decrease in dissolved oxygen by the growth of microorganisms in the water layer, leading to the anaerobic condition in which the redox potential of the sediments decreased. As such, the decreasing variability of phosphates bonded to iron oxide in the sediment phosphorus was higher after 20 days of the release experiment than the first day. It means that the metal ions and the separated inorganic phosphorus transfer into the water when the iron oxide is reduced. The separated inorganic phosphorus is easily absorbed by the plankton. The analysis of total phosphorus in the water layer showed that it continuously increased to up to 0.304 mg/L for 20 days, and the release rate had a high correlation with the decrease of dissolved oxygen after 5 days of culture. Therefore, it is necessary to pay attention to the characteristics of iron bonded to phosphorus in the phosphorus fraction and dissolved oxygen to manage the eutrophication of the system.