• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.632-639
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• 1997

The experiment which imposed the water stress to tobacco(Nicotiana tabacum L.) plant was carried at the late of maximum growth period. In order to know the influence of drought stress on the growth and developmemt of tobacco leaves of different position and to elucidate the physiological response of plant to various soil water content, stomatal conductance, and leaf water potential were measured. The drought stress at the maximum growth period negatively affected to the overall growth characteristics of shoot. The response of the growth was small at the middle and the lower leaves, and great at the upper leaves. The relative water content of upper, middle, and lower leaves at the fifth day after treatment were 74, 64, and 59%, respectively, as soil water content was reduced by 4.3%. This suggested that the wilting point of tobacco leaf was about 75%. The leaf water potential was -0.58 MPa in control and dropped to -1.20 MPa at the fifth day after treatment. This indicated that wilting of leaf may occur at the condition in which the difference of water potential between treatment and control, well watered, was greater than about 20%. Stomatal conductance at the fifth day after treatment dropped from 12 mol /$\textrm{m}^2 sec^{-1}$ to 0.8 mol /$\textrm{m}^2 sec^{-1}$ in the middle and the upper leaves. Stomatal conductance of lower leaves already matured were not affected highly by drought stress at the maximum growth period, but maturing leaves, middle and upper leaves, were highly affected by limitation of soil water.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.3
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• pp.191-198
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• 2005

In order to optimize tissue culture conditions for genetic transformation of orchardgrass, the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of 3 cultivars, 'Frode'. 'Roughrider' and 'Frontier' as explant tissues. Callus induction medium containing 3mg/L 2,4-D or 3mg/L dicamba each with 0.1mg/L BA was optimal fer embryogenic callus formation from mature seed and had a strong effect on successive plant regeneration. The regeneration frequency from embryogenic callus among cultivars were descending order of Roughrider > Frode > Frontier. Supplementation of the regeneration media with 10mg/L $AgNO_3$ and 40mg/L cysteine enhanced frequency of plant regeneration. Efficient regeneration system established in this study will be useful fur molecular breeding of orchardgrass through genetic transformation.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.333-339
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• 2015

The study was intended to investigate the factors affecting dental caries in adults. To that end, adults aged 19 years and older among 10,113 subjects who completed the health-related questionnaire, medical examination and nutrition surveys in the first year (2013) of the 6th Korea National Health and Nutritional Examination Survey, and 4,843 subjects categorized as patients with permanent teeth caries were included in the final analysis. The prevalence of dental caries in line with socio-economic aspects was found to be higher in men than in women. In view of education, the prevalence of dental caries was high in high school graduates, middle school graduates, college graduates and other advanced degree holders in the order named. Low monthly income earners showed the highest prevalence of dental caries. As for health-related lifestyles, the prevalence of dental caries was higher in smokers than in non-smokers. Obese subjects showed a little higher prevalence of dental caries compared to people of normal weight. Also, the prevalence was higher in those who failed to get oral examination than otherwise. Frequent daily toothbrushing and use of dental floss and interdental brush significantly decreased the prevalence of dental caries. In the logistic regression analysis with the presence or absence of dental caries employed as a dependent variable, gender, age, income level, smoking, oral examination and use of dental floss were found to serve as independent variables affecting dental caries. Therefore, Korean adults' socio-economic factors and lifestyles were proved to affect dental caries, which warrants some dental health programs and action plans designed to help lead healthy lifestyles whilst preventing dental caries and improving dental health in adults.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1239-1244
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• 2003

Microcapsules were prepared by coacervation method using acetone/liquid paraffin system to control the ripening of kimchi. Eudragit E100, which was soluble at below pH 5.0 in aqueous solution, was used to make microcapsules to be sensitive to acidity of kimchi. The microcapsules with Eudragit E100 containing grapefruit seed extract (GFSE) showed the highest yield of 92.13%, the size of microcapsules was decreasing as increasing the amount of aluminium stearate, a dispersing agent. Morphology of the microcapsules determined by scanning electron microscopy showed spherical forms. GFSE, encapsulated antimicrobial agents, was quickly released at acidic buffer (pH 4,5,6) within 1 storage day. However, 70% of encapsulated GFSE in Eudragit E100 microcapsules was continuously released at pH 7 till 3 days, and it was sustained till 9 days. Characteristics of kimchi containing microcapsules of GFSE were analysed with ripening period. Decease of pH in kimchi was retarded with the added GFSE microcapsules till 2 days of fermentation, but GFSE did not affect pH in kimchi after 3 days. Total numbers of microorganisms and lactic acid microorganisms in kimchi were decreased with increasing the amount of the added GFSE microcapsules, however, the effect of controlled released GFSE from pH sensitive Eudragit E100 microcapsules was hard to detect. These results suggest the possibility of pH sensitive microcapsules for high qualify of kimchi.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.297-311
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• 2011

This paper deals with a strategic investment decision model for improving investment profit in shipping industry. Despite the quantitative expansion of Korean shipping business, many shipping firms have suffered financial difficulties due to financial and operating risks that result from the characteristics of capital-intensive business as well as of volatility of shipping markets. As a result, managers in charge of making an investment decision, particularly in tramper business sector, are required to take both financial and operating risk factors into consideration. Put it differently, managers are strongly recommended to avoid these risks by ship asset play; buy-low and sell-high, which results in considerable capital gain and cost reduction. In addition, managers in shipping industry are also recommended to consider the ship chartering investment alternative when the freight markets show extreme volatility as the case of 2008 triggered by sub-prime mortgage financial crisis in USA. For example, the BDI suffered plunging down from 1000 in 2008 to 100 in 2010. Consequently, the 4th largest shipping company in Korea, DAEHAN Shipping Co., has collapsed primarily due to excessive tonnage expansion during the peak time of bulk market. In sum, the strategic investment decision model, suggested in this paper, is designed to include such factors as capital gain by asset play, timely chartering for alternative shipping service, and optimization of operating profit by tonnage adjustment in accordance with change in the shipping markets concerned.

• Journal of the Mineralogical Society of Korea
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• v.23 no.4
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• pp.357-365
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• 2010

Optically stimulated luminescence (OSL) of quartz is commonly applied to the age dating of Quaternary sediments. However, one of the issues is that some of the quartz samples are not suitable to OSL dating. Mineralogical analysis of the quartz samples with diverse OSL signals are required to strengthen the reliability and applicability of the OSL dating. We analysed the OSL signal characteristics of sedimentary quartz samples from diverse geological environments and measured their trace element contents using laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Quartz samples could be grouped into ones suitable to OSL dating and ones unsuitable on the basis of their OSL signal characteristics. The average trace element contents ranged from 73 to 260 ppm (Al), and from 61 to 248 ppm (Ti) with minor Li, Mg, Cr, Mn, and Fe contents below 40 ppm. We did not find any significant variation of trace element contents of quartz samples consistent with their OSL signal characteristics. This indicates unknown mineralogical factors causing diverse OSL characteristics which should be confirmed by further analysis of sufficient set of samples.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.478-485
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• 2014

This study is to form the self assembly of cubic crystalline phase to penetrate into the skin epidermis. The various performance synthesized diglyceryl phytylacetate (DGPA) having hydroxyl group (-OH) and 4 methyl chains with phytyl group was carried out as an amphoteric lipid such as emulsifying power, self assembly. Emulsifying activity of DGPA was very stabilized on only 1% of small content, it could make a W/O emulsion containing high internal phase incorporated with water. Cubic liquid crystal structure with DGPA on three-phase diagram was formed, when mixed DGPA, dimethicone (2CS), and water. Through three-phase diagram forming the cubic liquid crystal area, hexagonal structure zone, and mixing water phase and hexagonal structure area, reversed micelle area were respectively certified. Its structure was proved by the SAXS (small angled x-ray scattering) analysis. As an application, formation of cubosome containing 10% of magnesium ascorbylphosphate and 5% of pyridoxine tris-hexyldecanoate was encapsulated. Occlusive effect of cubosome had above 1.7 times better than reversed micelle. From using poloxamer of dispersing agent, phase structure recovered from W/O emulsion to cubic liquid crystal phase when storage in $33^{\circ}C$ incubator. Therefore, our this study is expected to be as epidermal-dermal skin absorbers in skin care cosmetics and pharmaceuticals industries as raw materials to form a cubic crystal phase through a more in-depth research to DGPA having amphoteric lipid property.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.208-214
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• 1993

Ginseng-whey beverages were prepared with rennet whey, ginseng, sweetener, honey and Japanese apricot, inoculated with different strains of lactic acid bacteria or unfermented partly. The samples were stored at 4$^{\circ}C$ or 30$\pm$1$0^{\circ}C$ and then physicochemical and microbiological properties were investigated. The yield of whey was 78.8%. The pH-values reduced and acidities increased during the storage period. The contents of solid-substances, ash and lipid in ginseng-whey beverages were 7.90~8.20%, 0.62~0.66% and 0.16%, respectively. The protein contents of ginseng-whey beverages were 0.42~0.56% and the contents were not changed during the storage period. The lactose contents of fermented beverages were higher than those of unfermented beverages. During the storage period (1~5 weeks), the ranges of D(-) - and L(+)- lactic acid contents in fermented ginseng-whey beverages (17.3~156.1 mg/100g, 347.3~1894.2mg/100g) were higher than those of unfermented ginseng-whey beverages (6.2~82.8mg/100g, 7.1~885.5mg/100g). The contents of total saponin in unfermented sample and fermented sample (Lac. casei sub-sp. casei+Str. salivarius sub-sp. thermophilus) were increased during the storage period. But, those of the fermented sample(Lac. acidophilus+Lac. delbrueckii sub-sp. bulgaricus) were reduced. In the electrophoretic results of ginseng-whey beverages, an $\alpha$-lactalbumin and a $\beta$-lactoglobulin bands were shown apparently and there were no changes observed during the storage period. During the storage period (1~3 week) the coliform was not detected and total plate counts and psychrotrophs were increased according to the storage period.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1241-1248
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• 2021

In order to figure out various environmental problems, various governments and companies are investigating more environmentally policies and technologies. In other words, activated carbon is widely used for the adsorption of different harmful gases and waste liquid treatment. However since the required surface properties are different in various industry, depending on the adsorption properties, the development of activated carbon demand in different ways. In this work, we have investigated and developed the activated carbon surface to improve the hydrophilic properties by nitric acid treatment through reforming of activated carbon.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1285-1294
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• 2018

The purpose of this paper was to identify the relationship between the characteristics of community mental health, and to identify if mediatable contextual property acts as factor influencing community mental health. Data of 229 municipal population groups were collected from KNSO and The 6th Community Health Plan. The data were analyzed using ANOVA, Spearman correlation, and multiple regression analysis. The perceived stress showed significant difference depending on health budget, mental health budget, number of mental health personnel, and was negatively correlated with proportion of the elderly, employment rate, percentage of NBLS recipients, health budget, and number of mental health personnel. The depressive mood differed depending on the number mental health personnel, and was negatively correlated with percentage of NBLS recipients and number of mental health personnel. Mental health budget and number of mental health personnel were respectively influencing factor of perceived stress and depressive mood. Following the above result, in order to reduce the gap between the mental health of communities, the researcher suggests that mental health budget as well as overall health budget and the number of mental health personnel be enforced.