• Korean Journal of Crystallography
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• v.11 no.4
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• pp.224-230
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• 2000

We have been investigated the flaking mechanism of the soda-line glass. The pH of aqueous solution approached to 10 and increased with reaction time by ion exchange reaction between Na/sup +/ ion of glass and H/sup +/ ion of aqueous solution under the conditions of below pH 9 of start solution. The relationship between the pH of solution and reaction time shows logarithm. Total dissolution reaction of glass components by OH/sup -/ ion in aqueous seems to be dominant after the pH solution reached to 10 and the dissolution rate linearly increased with reaction time. The above tow reactions are simultaneously occurred. The dissolved Ca/sup 2+/ ions are reprecipitated on the glass surface to Ca-compound. The flakes are formed by the separation of leached layer of glass due to the different thermal expansion coefficient.

• The Korean Journal of Ecology
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• v.19 no.3
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• pp.193-199
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• 1996

Alleviation of Al toxicity by Ca and Mg was studied with seedings of Pinus densiflora, P. rigida and P. thunbergii under the solution culture. The seedlings were cultivated in the enriched Can and Mg nutrient solution with 2, 000 ${\mu}M$ Al for three weeks. The hightest total root lengths of P. densiflora, P. rigida and P. thunbergii increased by 21, 33 and 133% in Ca enriched solution, and 23, 44 and 107% in Mg enriched solution, respectively. Ratios of lateral root to main root length increased significantly in Mg enriched solution, and redution of Al toxicity was more affected by enriched Mg than by enriched Ca. Al content in tissue was reduced by enriched Ca and Mg.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.405-410
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• 1996

The fermented black tea with tea fungus (FBTF) known to cure various diseases was prepared by culturing tea fungus biomass in black tae with different kinds (sucrose, glucose, fructose and corn syrup) and concentrations (10-60% m/v) of saccharides. pH changes and total acid production of FBTF were investigated during 14 dats incubation at $5-45^{\circ}C$ The patterns of acid production in sucrose and fructose black tea solution were similar each other, and those in glucose and corn syrup black tea solution were similar each other showing that tea fungus biomass utilizes fructose than glucose more efficiently. The optimum incubation temperature for the formation and growth of tea fungus Biomass, and the acid production was $30^{\circ}C$ Low contents of total aids (0.1%-0.2%) were produced in 20% of higher concentrations of sucrose and fructose black tea solution, while 1.8% and 0.68% were produced in the 10% of sucrose and fructose black tea solutions, respectively, pH of FBTF dropped to 2.74-3.56 after 2 days of incubation of all the culture solution and Kept this level to 14 days incubation.

• KOREAN ASSOCIATION OF OCCUPATIONAL HEALTH NURSES
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• v.19 no.1
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• pp.25-55
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• 2012

• The monthly packaging world
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• s.307
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• pp.94-99
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• 2018

• Journal of the Korean Applied Science and Technology
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• v.5 no.1
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• pp.25-30
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• 1988

In order to develope the method of quantitative determination of lipid hydroperoxide in human blood serum, we tried the ferrothiocyanate method to total lipids extracted by Bligh-Dyer method and obtained the results as follows. 1. The maximum absorbance showed at the concentration of Mohr's solution, 0.127M at pH 1.70 and ammonium thiocyanate solution, 3.95M in the ferrothiocyanate method. 2. When hydrogen peroxide, cumene hydroperoxide, and oxidized linoleic acid were added to serum, and extracted them by Bligh-Dyer method to examine the extraction efficiency, we confirmed that cumene hydroperoxide and oxidized linoleic acid were extracted in $CHCI_3$ phase, and hydrogen peroxide in $MeOH-H_2O$ phase, respectively. 3. The concentration of lipid hydroperoxide of total lipids extracted from normal adult serum was $2.0{\times}10^{-5}M$, and increased proportionally the concentration of lipid hydroperoxide by increasing the amount of serum. 4. When we compared the total lipids extracted by Bligh-Dyer method and total lipids extracted after lipoprotein is precipitated by Yagi method in human blood serum, the concentration of lipid hydroperoxide was showed nearly the same value. From our results, we concluded that the concentration of lipid hydroperoxide in human blood serum could be determined quantitatively by ferrothiocyanate method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.70-78
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• 2020

Under the situation which customer orders are cancelled unless all products in the order are delivered all at once, this paper concentrates on the purchase dependent demands and explores the systematic approach to implant the purchase dependence into the multi-product inventory model. First, by acknowledging that it is a challenging task to formulate a suitable inventory model for the purchase dependence, we derive the optimal solution condition using an EOQ model and extend the optimal solution condition to periodic review models. Then, through the comparison simulation of four inventory policies regarding several degrees of purchase dependence, we demonstrate that the inventory models which consider the purchase dependence generate less total cost than the inventory models which ignore the purchase dependence. In general, the inventory models which consider the purchase dependence reduce the loss of sales by maintaining more inventories, which results in reducing the total cost. Consequently, the simulation result supports the effectiveness of this paper's approach. In addition, this paper uses the individual order period and joint order period obtained from the EOQ model for the multi-product inventory model. Through the in-depth analysis of comparing the two models, we observe that the model of using the joint order period produces less total cost when the degree of purchase dependence is high, but the model of using the individual order period produces less total cost when the degree of purchase dependence is low.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.3
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• pp.375-383
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• 2009

This study was conducted to measure the total polyphenol contents and DPPH radical scavenging activities of different potato plants parts, varieties, and grades, and by distribution and different cooking conditions. The results were as follows. For the plant parts, total phenolic content and DPPH radical scavenging activity were highest in the flowers followed by leaves and stems, respectively. Among 5 potato varieties, 'Jasim' had the highest DPPH radical scavenging activity and the activity of its pulp was lower than that of its cortex(peel). Regardless of potato grade, the cortexes(peel) of samples had two-fold higher DPPH radical scavenging activity than pulp, and the Grade SS potato had the highest phenolic content. It was also found that the bud ends and stem ends had comparably larger amounts of phenolic compounds in horizontally cut potatoes. Finally, the descending order for DPPH radical scavenging activity, according to different cooking conditions, was as follows: gas oven range-baking, frying, microwave-heating, sauteing, boiling in 1% saline solution, steaming, and boiling in 3% saline solution.

• Journal of Plant Biology
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• v.37 no.3
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• pp.301-308
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• 1994

The individual and combined effects of acidic rain, Mg deficiency (-Mg) and Al surplus (＋Al) on the growth of shoots and roots of pitch pine seedlings and the effect of humic substances (Lit) on Al toxicity were investigated. The growth of height and dry matter were not significantly less for pitch pine seedlings sprayed with simulated acid rain (SAR) of pH 3.5 than for those sprayed with SAR of pH 5.6. But treatments of Al and ＋Al-Mg in soil solution reduced the growth of seedlings in terms of height of shoots, and dry matter of shoots or roots. Effect of Mg deficiency on the growth of seedlings was apparent only when Al was treated simutaneously. The growth of seedlings, regardless of rain pH, decreased in the following order: control=-Mg>Lit＋Al>＋Al>＋Al-Mg. Treatments of Al and ＋Al-Mg in soil solution reduced the total length of secondary and teritary roots of seedlings regardless of rain pH, and decreased in the following order: the primary root

• Journal of Environmental Science International
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• v.24 no.8
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• pp.1075-1084
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• 2015

This study was conducted to investigated the changes in the nutrient components ($NO_3{^-}-N$, $NH_4{^+}-N$, $PO_4{^{3-}}P$, $K^+$, $Ca^{2+}$, and $Mg^{2+}$) and environmental parameters (electrical conductivity, total dissolved solids and pH) on the leaf lettuce (Lactuca sativa L.) grown with hydroponics. Recirculating hydroponic cultivation system was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic. Nutrient solution was used in the standard solution for Japan vegetables experimental station and commercial hydroponic. The result showed that electrical conductivity (EC), total dissolved solids (TDS) and pH, depending on the growth of lettuce decreased continuously. With the growth of the lettuce, nitrate nitrogen, ammonia nitrogen, phosphate phosphorus were required for periodic replacement. The number of pH compensation due to the growth of lettuce are the most high. The concentration of $Ca^{2+}$ and $Mg^{2+}$ during the lettuce growth showed no significant change. However, $K^+$ concentration increased due to the replacement with nitrogen and phosphorus. Electric conductivity and total dissolved solids with total nutrient concentration showed the linear relationship and the correlation coefficient $R^2$ were 0.8601 and the 0.827, respectively.