• Korean Journal of Soil Science and Fertilizer
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• v.6 no.1
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• pp.17-26
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• 1973

A survey on nutrient recovery by rice plant was carried out countrywide in 1967 and 1968. The relationships between percent recovery of fertilizer nutrient and climatic zone or deposition mode, drainage grade, and texture of paddy soil profile, or chemical characteristics of surface soil were as follows. 1. The percent recovery of fertilizer nitrogen was highest in south and least in north, and that of potassium was highest in south and least in middle climatic zone. 2. Since the percent recovery of Phosphorus variates yearly with climatic zone, mode of deposition drainage grade or soil texture, it seemed to depend greatly on soil-weather interaction. 3. Nitrogen recovery was highest in alluvial colluvial (AC) and it was followed by alluvial (A), fluvomarine (FM) and old alluvial in decreasing order while potassium recovery was OA>AC>A>FM. 4. The greater the drainage was, the higher the nitrogen recovery. The recovery of potassium and phosphorus tended to show high in moderately well drain, and low in poorly and well drain. 5. Nitrogen recovery was highest in fine silty and gradually decreased with coarseness. That of potassium or phosphorus was greater in those below fine loamy than in those above coarse silty. 6. Nitrogen recovery was high in Jisan, Geugrag, and Sindab series, and low in Hwadong, Gyuam, Yongji and Hwabong series. 7. Nitrogen recovery showed significant positive correlation with the content of organic matter (OM), Ca, CEC of surface soil and only in the year of high phosphorus recovery it had significant negative correlation with soil phosphorus. Phosphorus recovery had significant posititive correlation with CEC, Mg or Ca. 8. Potassium recovery showed negative correlation with K/(Ca+Mg), P, OM or K while positive correlation with Ca, Mg, CEC but significant only with K/(Ca+Mg) in the year of low potassium recovery. In the year of high K recovery it showed positive correlation with P, OM, K/(Ca+Mg) or K while negative with CEC, Mg or Ca but significant only with P, OM or CEC. Soil potassium has significant positive correlation with soil OM and P only in the year of low potassium recovery. 9. The percent recovery of N, P or K showed negative correlation coefficient with pH without significant. 10. There was significant positive correlation between OM and P, K or K/(Ca+Mg), P and K or K/(Ca+Mg), K and K/(Ca+Mg), Mg or CEC, Ca and K/(Ca+Mg), Mg, CEC or pH, Mg and CEC while significant negative correlation between Mg and OM, P or K/(Ca+Mg), P and CEC, Ca and K/(Ca+Mg). 11. From the percent rcovery of fertilizer and soil chemical characteristics it was known that soil organic matter increase nitrogen uptake, that K uptake has closer relation to K/(Ca+Mg) than K, that Mg affects P ugtake, and that the annual difference of P and K recovery was partly explainable.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.4
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• pp.175-180
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• 2012

Role of Ca in grain growth behavior has been investigated in hot-rolled Al-3%Mg and Al-3%Mg-0.5%Ca wrought alloys. When annealed for 1 hr from 723 to 823 K, grain size of the Al-3%Mg alloy increased rapidly above 723 K, whereas grains were relatively stable up to 773 K for the Ca-containing alloy. Grain homogeneity of the Ca-containing alloy was better than that of the Ca-free alloy both in hot-rolled and annealed states. Calculated activation energies for grain growth were 77.6 and 85.9 kJ/mole in the range of 723 to 823 K for the alloys with 0 and 0.5%Ca, respectively. Taking SEM images and EDS results into account, enhanced thermal stability in response to Ca addition would be associated with Al4Ca compounds located along the grain boundaries, which eventually play a role in restricting grain growth at elevated temperatures.

• Journal of the Korean Vacuum Society
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• v.8 no.1
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• pp.70-74
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• 1999

MgO-CaO protective layers with various composition were prepared by electron beam evaporation to improve the characteristics of conventional pure MgO thin films as a protective layer for AC-PDP. The maximum deposition rate of pure MgO was 1025 $\AA$/min and decreased with increasing [(CaO/(MgO+CaO)] ratio of evaporation starting materials. From XRD analyses, a trend of peak shift to the lower 2$\theta$ angle side was shown as CaO content increased and it stoped when the concentration of CaO was 0.13, which corresponds to the maximum solubility of CaO in MgO. The optimum composition of the protective thin films was Mg 47.1 at%, Ca 1.3 at%, O 51.6 at%, and firing voltage, memory margin and deposition rate of the film with this composition was 176 V, 0.5 and 515 $\AA$/min, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.709-715
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• 1993

This study was carried out to estimate the relationship among dietary intakes, blood levels, and urinary excretions of Ca, P, Mg and serum lipid levels in 30 healthy adults living area of Korea(12males and 18 females). Analyses for the nutritional status of the subjects were performed by 3-day dietary intake record, duplicated diet collection, 24-hours urine collection, and venous blood sampling before anthropometry. The mean daily intakes of Ca, P and Mg estimated for 3 days were 452.5$\pm$159.5mg, 725.6$\pm$ 567.8mg and 240.4$\pm$78.5mg and the serum concentrations of Ca, P and Mg were 8.9$\pm$ 0.5mg / dl, 3.3$\pm$0.6mg / dl, and 2.1$\pm$0.8mg /dl, respectively. The 24-hour urinary excretions of Ca, P and Mg were 80.4$\pm$24.0mg, 399.0$\pm$161.1mg and 64.8$\pm$35.3mg, respectively. The serum concentrations of total cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol were 158.8$\pm$32.9mg/dl, 95.6$\pm$43.9mg/dl, 45.7$\pm$9.9mg/dl and 92.2$\pm$ 28.5mg/dl, respectively. In the relation between Ca, P, Mg and serum lipids it showed positive correlation with serum Ca and HDL-cholesterol at the level of significance of 5%. It can be concluded that the high level of Ca in serum may be useful in the prevention of cardiovascular disease, but the study verifies the need for more systematic studies.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.611-616
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• 1998

Although the $Ca^{2+}-activated\;K^+\;(I_{K,Ca})$ channel is known to play an important role in the maintenance of resting membrane potential, the regulation of the channel in physiological condition is not completely understood in vascular myocytes. In this study, we investigated the role of cytoplasmic $Mg^{2+}$ on the regulation of $I_{K,Ca}$ channel in pulmonary arterial myocytes of the rabbit using the inside-out patch clamp technique. $Mg^{2+}$ increased open probability (Po), but decreased the magnitude of single channel current. $Mg^{2+}-induced$ block of unitary current showed strong voltage dependence but increase of Po by $Mg^{2+}$ was not dependent on the membrane potential. The apparent effect of $Mg^{2+}$ might, thus, depend on the proportion between opposite effects on the Po and on the conductance of $I_{K,Ca}$ channel. In low concentration of cytoplasmic $Ca^{2+},\;Mg^{2+}$ increased $I_{K,Ca}$ by mainly enhancement of Po. However, at very high concentration of cytoplasmic $Ca^{2+},$ such as pCa 5.5, $Mg^{2+}$ decreased $I_{K,Ca}$ through the inhibition of unitary current. Moreover, $Mg^{2+}$ could activate the channel even in the absence of $Ca^{2+}.\;Mg^{2+}$ might, therefore, partly contribute to the opening of $I_{K,Ca}$ channel in resting membrane potential. This phenomenon might explain why $I_{K,Ca}$ contributes to the resting membrane potential where membrane potential and concentration of free $Ca^{2+}$ are very low.

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.516-530
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• 1989

A 44-day metabolic study was conducted to compare the effects of soy protein and meat protein on N, Ca, P, and Mg metabolism in young Korean males. Meat protein diet(MPD) and soy protin diet(SPD) were provided for 3 weeks each. For MPD, meat protein Supplied 50.3% of total protein and mean daily suplies of Ca, P, and Mg were 33.28mg, 1013.01mg, 226.81mg respectively. For SPD, soy protein supplied 51.8% of total protein and mean contents of Ca, P and Mg were 737.86mg, 1261.76mg, and 451.3mg. Mean daily fecal and urinary excretions of Ca were 350.6mg and 113.3mg for MPD and 515.0mg and 118.3mg for SPD. Apparent absorption rates in MPD and SPD were 4.2mg in MPD and 700.4mg and 475.1mg SPD. Apparent absorption rates were 65.6% in MPD and 44.5% in SPD(p<0.01). For Mg, fecal and urinary excretions were 144.8mg and 81.2mg in MPD and 292.4mg and 65.5mg in SPD. Apparent absorption rates were 37.5% in MPD and 35.2% in SPD. The correlations between urinary Ca, P, and their balance were significant (p<0.001) in MPD, but not in SPD. Urinary Ca was significantly correlated with urinary N, P, Mg(p<0.001) in MPD, but not in SPD. From these results, meat protein seems to increase the excretions of major minerals compared to soy protein.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.419-423
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• 2008

The present study examined the effects of different calcium (Ca) sources and concentrations on the growth and Ca absorption of Agrocybe cylindracea mycelia grown in submerged cultures. The dry weights of the mycelia were not significantly different (significance level of 5%) according to the type of Ca added, and increased with increasing Ca concentration until 500 mg/L, and then decreased at concentrations of 1000 mg/L or greater. The Ca contents of groups were significantly different according to the various concentrations of the Ca source, in which the Ca content of the control group cultured without added Ca was 198.3 mg/kg, and in the treatment groups, Ca content increased to a minimum of 273.7 mg/kg (1.4 times) and a maximum of 67246.0 mg/kg (339.1 times) the Ca contents of the groups generally increased with increasing Ca concentration. According to the number of culture days, growth rates were highest during days 8 through 12, and remained relatively high until day 16. In addition, Ca contents per unit dry weight were higher in young mycelia with a shorter culture period than in mature mycelia with a longer culture period. According to pH, the most active growth and highest Ca content occurred in MCM liquid medium at pH 7.0. In conclusion, in order to produce Agrocybe cylindracea mycelia with high Ca content, it is considered most efficient to culture them in MCM liquid medium without a pH adjustment and containing 1,000 mg/L of Ca-lactate, which is commonly used as a Ca additive in food, as well as to use mycelia between 12-16 days of culturing.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.1
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• pp.26-33
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• 1989

This pot experiments were conducted to find out the optimal fertilization ratios of the N:S:P anions and K:Ca:Mg cations of major nutrients in an orchardgrass/ladino clover mixed sward. The optimum ratios in equivalent basis were computed by the Homes systematic variations technique. The soil samples were collected from the newly reclaimed soils, which are located on colluvial hilly area with a good consideration for the hilly pasture development. The results were summarized as follows; 1, the optimum fertilization ratios of major nutrients for the high yields by the forage species in a mixed sward were obtained (Table 4 in detail); N:S:P = 3:l: 1 and K:Ca:Mg = 1:l: 1 for grass and grass plus legume, and N:S:P = 1:6:43 and K:Ca:Mg = 1: 3: 1 for legume in general. 2. The yield increases from the systematic variations in this mixed sward were laid in following order; N > P >S-group and K >Mg >Ca-group for grass and grass plus legume, and P >S >N-group and Ca >Mg > K-group for legume. Especially, the yields were greatly increased at the N-group for grass, and at the Pand Ca-groups for legume. 3. Soil pH-value was descreased at the Sgroup, and somewhat increased at the Ca- and Mg-groups. The content of available $P_2O_5$, CEC and base saturation were greatest with the Ca-group. 4. At the N-group, the N-contents were highest and the P-contents were lowest in grass and grass plus legume, which resulted in the highest Ca/P ratio of 2.15 among the anion groups. Whereas the highest Ca/P ratio of 9.20 in legume was obtained at the Ca-group. Legume showed in general higher Ca/P ratio and lower K/(Ca+Mg) ratio than these in grass. 5 . There were differences in the effects of systematic variations of major nutrients on the dry matter yields and the mineral yields. The optimum fertilization ratios of anions and cations for the high mineral yields were obtained (Table E), which showed differences comparing with the ratios for the high dry matter yields. The antagonis between the cations K and Mg was known from the point of mineral yields of mixed forages.

• Journal of Korea Foundry Society
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• v.26 no.2
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• pp.77-84
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• 2006

The effect of alloy composition on the glass forming ability (GFA) of the Ca-rich Ca-Mg-Zn alloys has been investigated in $Ca_{65}Mg_{5+x}Zn_{30-x}$ and $Ca_{55+x}Mg_{15}Zn_{30-x}$ (x=0, 5, 10, 15, 20) alloys. In a wide composition range of 15-25% Zn and 10-20% Mg bulk metallic glass (BMG) samples with the diameter larger than 6 mm are fabricated by conventional copper mold casting method in air atmosphere. Among the alloys investigated, the $Ca_{65}Mg_{15}Zn_{20}$ alloy exhibits the highest GFA enabling to form BMG sample with the diameter of at least 15 mm. The crystalline phase formed during solidification of $Ca_{65}Mg_{15}Zn_{20}$ ($D_{max}=15\;mm$) could be identified as a mixture of $Ca_3Zn$ and $CaMg_2$ cause by the redistribution of the constituent elements on long-range scale. The compressive fracture strength and fracture elongation of the $Ca_{65}Mg_{15}Zn_{20}$ BMG are 602 MPa and 2.08% respectively. The ${\sigma}$ parameter which has been recently proposed for evaluating GFA exhibits better correlation with GFA of Ca-Mg-Zn alloys than other parameters suggested so far such as ${\Delta}T_x$, $T_{rg}$, K, ${\gamma}$, and ${\Delta}T^*$ parameters.

• Journal of Nutrition and Health
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• v.36 no.9
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• pp.942-949
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• 2003

This study was longitudinally conducted to evaluate the intakes of protein, Ca, Mg and P of exclusively breast-fed infants compared with the Recommended Dietary Allowances (RDA) for Korean infants. Twenty Korean lactating women and their infants during the first 3 months of lactation in Incheon area were participated. Protein, Ca and Mg, and P contents in the milk were determined using semimicro Kjeldahl (N ${\times}$ 6.38) , atomic absorption spectrophotometer and colorimeter, respectively, and also the milk consumption of the infants was measured by the test-weighing method. Protein contents of the milk were 1.96, 1.63, 1.51, 1.25 and 1.16 g/100 ml, and protein intakes of the breast-fed infants were 9.00, 9.85, 9.17, 8.97 and 7.76 g/day at 7, 15, 30, 60 and 90 days postpartum. The average protein intake per body weight of the breast-fed infants was 1.84 g/kg/day. The average intakes of Ca, Mg, P were 172.1 mg/day, 15.2 mg/day and 91.4 mg/day, respectively, and the average Ca/P ratio was 1.91. There was positive correlation between protein and Ca, protein and p, and Ca and P contents while negative correlation between Mg and P, The body weight of breast-fed infants increased normally from 3.6 $\pm$ 0.41 g at birth to three month during lactation. It is suggested that the breast-fed infants in Incheon area consume almost adequately protein, Ca and P from the milk compared with RDA for Korean infants.