• Applied Chemistry for Engineering
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• v.2 no.3
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• pp.270-278
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• 1991

Carboxymethyl chitin(CM-chitin) was prepared by the reaction of alkali chitin with monochloroacetic acid in isopropyl alcohol. According to the pH variation, the adsorptivity of this chelating polymer to the alkali-earth metal ions such as $Ca^{2+},\;Mg^{2+}$, $Sr^{2+}$, $Ba^{2+}$ ions was determined by batch method. The adsorption tendency of this chelating polymer to most metal ions was increased with the increase of pH. The highest degree of adsorption was observed toward $Ca^{2+}$ ion among the alkali-earth metal ions. The selectivity adsorption property toward $Ca^{2+}$ ion was examined in the solution of $Ca^{2+}$ and $Mg^{2+}$ ions, and it was observed that CM-chitin showed excellent selectivity to $Ca^{2+}$ ion than $Mg^{2+}$ ion. $Mg^{2+}$ ion bound to CM-chitin molecule in the presence of $Ca^{2+}$ ion owing to low equilibrium constant. In the adsorption experiment of $Ca^{2+}$ and $Mg^{2+}$ ions to the CM-chitin under coexistence of $Na^+$ and $K^+$ ions, it observed that adsorptivity of only $Ca^{2+}$ ions was not affected by these monovalent cations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1327-1328
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• 2013

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.206-213
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• 1998

This experiment was conducted to investigate the effects of concentration of NO$_{3}$$^{[-10]}$ , $K^{＋}$ and $Ca^{＋＋}$ in nutrient solution on the seedlings growth of ‘Mudeungsan’watermelon. Seeds were sown on March 16, 1997. NO$_{3}$$^{[-10]}$ , $K^{＋}$ and $Ca^{＋＋}$ was treated with three different levels, respectively, NO$_{3}$$^{[-10]}$ = 106, 206, 406ppm; $K^{＋}$ = 150, 200, 400 ppm; $Ca^{＋＋}$ = 150, 200, 400 ppm. Plant growth was investigated at four-days interval in 10 days after treatment. Increasing N concentration in the nutrient solution increased the plant height, leaf area, number of leaves, fresh and dry weight of shoot while high concentration of K and Ca in the nutrient solution decreased the seedling growth in terms of leaf area, leaf dry weight. The uptake of N, K and Mg in petiole sap was positively affected by the adding of 206 ppm of nitrate, 150 ppm of potassium and 200 ppm of calcium levels, respectively. The P and Ca uptake in petiole sap was not affected by the N and K concentrations in the nutrient solution while K concentration above 200 ppm decreased the N and Mg content in petiole sap. High concentration of Ca in the nutrient solution increased the Ca content in petiole sap while Ca concentration above 200 ppm decreased the N content.

• Journal of Nutrition and Health
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• v.25 no.1
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• pp.22-31
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• 1992

In order to study on the Na, K, Ca, Mg content of low sodium diet used in hospital the mineral content of low sodium diet and general diet was measured at C Hospital in Taegu during June 26~28 in 1990. Results were as follows; 1)Energy per day was basis on 2300 Kcal in low sodium diet and general diet. 2) Na content per day of low sodium diet and general diet were 2510.0mg and 3580.3mg 3) K content per day of low sodium diet and general diet and general diet were 676.1mg and 1132.9mg. 4) Ca content per day of low sodium diet and general diet were 662.9mg and 605.4mg 5) Mg content per day of low sodium diet and general diet were 443.1mg and 278.7mg.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.479-482
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• 1991

The medical use of Acer mono MAX. and Betula costata T. sap has had the long history in Korea. So the mineral and sugar contents of these sap gathered in Mt. Jiri area at spring were analyzed to investigate the scientific base of folk remedies by using ion liquid chromatography and high performance liquid chromatography. The values of chlorine and sulfate in Acer mono MAX. were 11.5 mg/l and 176.7 mg/l, and in Betula costata T. 26.5 mg/l and 162.4 mg/l, respectively. The values of potassium, sodium, calcium and magnesium in Acer mono MAX. were 67.9 mg/l, 5.6 mg/l, 73.8 mg/l and 4.5 mg/l, and in Betula costata T. were 152.1 mg/l, 9.7 mg/l, 39.2 mg/l and 5.7 mg/l, respectively. The values of copper, zinc and manganese in Acer mono MAX. were 0.057 mg/l, 0.483 mg/l and 5.071 mg/l, and copper, zinc, mangances and iron in Betula costata T. were 0.038 mg/l, 1.584 mg/l, 4.354 mg/l and 2.511 mg/l, respectively. The values of sucrose in Acer mono MAX. were 27.29 mg/l, glucose and fructose in Betula costata T. were 0.97 g/l and 3.05 g/l, respectively.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.4
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• pp.547-553
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• 2007

The physicochemical and functional properties of tofu prepared with kanghwang(Curcuma aromatica Salab.) were investigated, in order to study the effects of six different commercial coagulants. The coagulant concentrations were determined as 0.3% GDL, 0.3% $MgCl_2$, 1.0% $CaCl_2$, 1.5% $CaSO_4$, 0.45% mixed coagulant, and 1.5% Milky-Mg by pre-experiments. Also, the optimum concentration for the added kanghwang(Curcuma aromatica Salab.) was chosen as 0.01%. The yields of the kanghwang tofu prepared with Milky-Mg, mixed, and GDL coagulants were higher than those prepared with $MgCl_2$, $CaCl_2$, and $CaSO_4$. The pH of the kanghwang tofu prepared with the $MgCl_2$ coagulant was higher than when made with the other coagulants. The turbidity of the kanghwang tofu was highest when it was coagulated with GDL, and moisture content was highest or the of kanghwang tofu coagulated with $CaCl_2$. In the color analysis of the kanghwang tofu, the $L^{***}$ value was highest with the Milky-Mg coagulant, while the $a^{***}$ value was highest and the b value lowest with the GDL coagulant. For the textural properties, the hardness results were in the order of $CaSO_4$ > $CaCl_2$ > $MgCl_2$ > mixed > GDL > Milky-Mg, springiness, gumminess, and brittleness were highest in the tofu coagulated with Milky-Mg. For the overall acceptability of the sensory properties, the Kanghwang tofu that was made using the mixed coagulant had the highest score.

• Journal of Nutrition and Health
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• v.25 no.2
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• pp.132-139
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• 1992

A study was conducted to compare urinary Ca excretion and factors influencing urinary Ca excretion in 30 young and 62 middle-aged Korean women. Mean daily intake levels of total protein and P were significantly higher in middle-aged women but Ca and animal protein intake levels of the two groups were similar. The average percentage of daily Ca intake from milk and milk products in young women was 45% while in middle-aged women it was about 24% The frequency of milk consumption was inversely correlated with blood pressures of the subjects. Mean 24-hour urinary calcium excretion in young and middle-aged women were 163.7mg and 174.9mg respectively. The difference was not significant. Menopause of the mid-dle-aged women did not affect urinary calcium levels. However the proportion of subjects with more than 250mg of Ca in 24-hour urine tended to be higher in middle-aged group Factors significnatly correlated with urinary Ca excretion of subjects were systolic and diastolic The study verifies the need for more systematic studies on Ca requirements and the interrelation-ship among Ca and na metabolism blood pressures and bone loss in the middle-aged Korean.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.31-35
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• 1975

In order to gain information on the plant characteristics of high yielding paddy from the point of view of mineral nutrition and to learn more about soil conditions under which high yields are produced a number of soil samples collected from the field experiment carried out in The City College of Seoul were analysed. In addition, a laboratory experiment carried out to support the field experiment was also analysed. Results obtained are as follows: 1. Generally, the higher the yield of paddy, the higher is the potassium content in flag leaves, whereas the reverse is true for the content of Ca and Mg in the leaves. From these facts it can conceivably be said that the high yielding paddy should absorb a large quantity of potassium and a lesser quantity of calcium and magnesium in the reproductive stage. 2. Leaves of paddy which produced yields over 600kg/10a (a comparatively high yield in the experiment) contained 30-35mg/100g of potassium, less than 25me/100g of calcium, and 10me/100g of magnesium which brings the ratio of $K/{\sqrt{Ca+Mg}}$ over 5. 3. Correlation studies indicated a remarkable relationship between the paddy yield and exchangeable potassium in soil samples taken after harvesting. A similar relationship was observed between the yield of paddy and $K/{\sqrt{Cae+Mge}}$ ratio of the soil samples. 4. A regression between yield of padcy (Y) and exchangeable potassium (Ke) or $K/{\sqrt{Ca+Mg}}$ in soil samples taken after harvesting was shown to be; Y=183.95+2135.86Ke $$Y=352.45+3114.454\;K/{\sqrt{Ca+Mg}}$$ 5. The regression between exchangeable potassium (Ke) in soil samples taken after harvesting and the amount of lime (L) and potassium (P) to be applied is; $$Ke=0.1246+0.00007037L+0.004444P+0.000004444L{\cdot}P$$.

• Economic and Environmental Geology
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• v.30 no.4
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• pp.327-340
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• 1997

Geochemical characteristics of groundwater, based on chemical analyses of 54 water samples, differ among main rocks of Haman formation, Panyawoel formation, andesite and granite in Daegu area in relation to mineralogical and chemical compositions of the rocks. Concentrations of most solutes are higher in groundwaters of Haman and Panyawoel formations than in those of andesite and granite. High concentrations of $Ca^{2+}$ and $Mg^{2+}$ in groundwaters of the sedimentary rocks result mainly from reaction of $CO_2$-charged water with calcite and weathered feldspars. Average groundwaters in the sedimentary rocks are oversaturated with respect to calcite. Major types of groundwaters are hard $Ca(HCO_3)_2$ and $CaSO_2-CaCl_2$ with hardness of 442 mg/l for Haman formation and 275 mg/l for Panyawoel formation whereas they are soft $Ca(HCO_3)_2$ with hardness 35 mg/I for andesite and 39 mg/I for granite. $Ca(HCO_3)_2$ type results mainly from calcite-dissolution and $CaSO_4-CaCl_2$ from pyrite and partly from domestic pollutants. $CaSO_4-CaCl_2$ type may indicate that groundwaters in the sedimentary rocks are more evolved geochemically than those in the igneous rocks, but it is not obvious because the type might be affected by pyrie dissolution and domestic pollutions. Acid rain is buffered by active calcite in the sedimentary rocks. In the igneous rocks acid rain might react with gibbsite and other forms of $Al(OH)_3$ that might have accumulated as weathering products of primary silicates, and is buffered.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.223-229
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• 2006

To develop multifunctional microbial inoculant, an insluble phosphate-solubilizing bacterium with antifungal activity was isolated from plant rhizospheric soil. On the basis of its morphological, cultural and physiological characteristics and Biolog analysis, this bacterium was identified as Pseudomonas fluorescens RAF15. P. fluorescens RAF15 showed antifungal activities against phytopathogenic fungi Botrytis cinerea and Rhizoctonia solani. The optimal medium composition and cultural conditions for the solubilization of insoluble phosphate by P. fluorescens RAF15 were 1.5% of glucose, 0.005% of urea, 0.3% $MgCl_2{\cdot}6H_2\;0.01%\;of\;MgSO_4{\cdot}7H_2O\;0.01%,\;of\;CaCl_2{\cdot}2H_2O$, and 0.05% of NaCl along with initial pH 7.0 at $30^{\circ}C$. The soluble phosphate production under optimum condition was 863 mg/L after 5 days of cultivation. The solubilization of insoluble phosphates was associated with a drop in the pH of the culture medium. P. fluorescens RAF15 showed resistance against different environmental stresses like $10-35^{\circ}C$ temperature, 1-4% salt concentration and pH 2-11 range. The strain produced soluble phosphate to the culture broth with the concentrations of 971-1121 mg/L against $CaHPO_4$, 791-908 mg/L against $Ca_3(PO_4){_2}$, and 844 mg/L against hydroxyapatite, respectively. However, the strain produced soluble phosphate to the culture broth with the concentrations of 15 mg/L against $FePO_4$, and 5 mg/L against $AlPO_4$, respectively.