• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.93-94
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• 2023

This study evaluated the mechanical properties and microstructure of calcium silicate cement based paste according to carbonation curing conditions. As a result, both compressive strength and carbonation depth increased with the carbonation curing period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.1016-1023
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• 1996

The effect of dietary calcium levels, 50%, 100%, and 200% of requirement, on iron utilization was evaluated in 30 Sprague-Dawley female rats by use of balance study for 3 weeks. In the results of this study, there were no significant difference in feed intake, body weight gain, hemoglobin level, hematocrit, calcium and iron levels in serum and tissues across the groups supplemented different calcium levels. Calcium content in kidney of high-calcium group was significantly higher than that of other groups. Urinary and fecal calcium excretions increased as the level of dietary calcium was increased. With increasing levels of dietary calcium, daily calcium retention was accelerated, but daily calcium retention rate was diminished. Iron intake was significantly higher in adequate-calcium group than that in low-calcium or high-calcium group. Urinary and fecal iron excretions were significantly lower in low-calcium group than those in adequate-calcium or high-calcium group. Apparent retention and retention rate estimated by intake, urinary and fecal excretions of iron were significantly lower in high-calcium group t]lan those in low-calcium or adequate-calcium group. These results suggest that taking dietary calcium supplements reduce the absorption of dietary iron.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.4
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• pp.439-445
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• 1999

This study is to investigate the mechanism of inhibitory effect of imipramine on the calcium utilization in single cells isolated from canine detrusor. 2 mm thick smooth muscle chops were incubated in 0.12% collagenase solution at $36^{circ}C,$ and aerated with 95% $O_2/5%\;CO_2,$ and then cell suspension was examined. Acetylcholine (ACh) evoked a concentration-dependent contraction of the isolated detrusor cells in normal physiologic salt solution (PSS), and the ACh-induced contraction was significantly inhibited by imipramine. In $Ca^{2+}-free$ PSS, ACh-induced contraction was less than those in normal PSS and it was not affected by the pretreatment with imipramine. $Ca^{2+}-induced$ contraction in $Ca^{2+}-free$ PSS was supressed by imipramine, but addition of A 23187, a calcium ionophore, overcomed the inhibitory effect of imipramine. High potassium-depolarization (40 mM KCl) evoked cell contraction, which was inhibited by imipramine. Caffeine, a releasing agent of the stored $Ca^{2+}$ from sarcoplasmic reticulum, evoked a contraction of the cells that was not blocked by the pretreatment with imipramine. These results suggest that imipramine inhibits the influx of calcium in the detrusor cells through both the receptor-operated- and voltage-gated-calcium channels, but does not affect the release of calcium from intracellular storage site.

• Resources Recycling
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• v.13 no.2
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• pp.33-38
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• 2004

Concepts and experimental results for the unique utilization process which we could obtain the high purity calcium nitrate from blast furnace slag in the steel industry are described. Firstly we reacted the blast slag with nitric acid and separatively removed the insoluble silica by filtration. We adjust the pH of filtrate to 6∼8 with calcined lime, and then precipiated out the metal components like Fe, Al, Mg in the forms of hydroxides. Consequently concentration of the mother liquor and crystallization processes make us obtain the high purity (>98 wt%) calcium nitrate tetrahydrates, which is expected the valuable fertilizers.

• Korean Journal of Environmental Biology
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• v.25 no.3
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• pp.228-238
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• 2007

Calcium plays an important role for the organisms' physiology, reproduction, and growth. Calcium amount and transfer efficiency along trophic levels were compared at two different geological areas, Limestone area (LS) and Granitic Gneiss area (GG) in 1992 and 1993. Biomass and calcium amount of plants, herbivores and carnivores were seasonally measured. The removal sweeping net method was used to collect the quantitative insect samples. Calcium content (mgCa $g^{-1}$ DM) and pH of soil were 4.85 and 7.3 at LS and 0.21 and 7.3 at GG. The calcium transfer efficiencies (%) at LS and CG were 0.2 and 4.2 from soil to plants, 0.002 and 0.02 from plants to herbivores, and 73 and 47 from herbivores to carnivores, respectively. As a whole, the high calcium content of the LS soil reduced the utilization of calcium by plants. The higher trophical levels were, the higher ecological efficiency of the biological levels was. The calcium transfer amount was higher at LS, but its efficiency was rather higher at GG.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 1995.10a
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• pp.1-21
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• 1995

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.526-531
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• 2001

LD slag, that is, a by-product of steel making process, has been mainly used as land construction materials. Recently, the seashore application of LD slag was tried in Japan and Korea tut the reaction between LD slag and seawater was not studied yet. We tried to clarify the leaching reaction and/or mechanism of LD slag and the reaction between seawater and LD slag. We tried to apply these results to the decarbonization of seawater for seawater magnesia process. At first, LD slag was milled and classified into 5 grades, that is, (ⅰ)45${\mu}{\textrm}{m}$ under, (ⅱ)0.25~0.5mm (ⅲ)0.5~1mm(ⅳ)1~2mm, (ⅴ)2.36~3.35mm. These slags were leached in the distilled water. In case of 45${\mu}{\textrm}{m}$ under, the pH of the leached solution was over 12. The chemical analysis of leached solution showed that the $Ca^{+}$$^2$was main component and the S $i^{+}$$^4$was very low. On the other hand, the content of S $i^{+}$$^4$in leached solution was decreased with the increase of pH of this solution. The nearly pure calcium solution was made and the ultra high purity MgO could be made with this calcium solution. The leaching behavior of LD slag was different between the fine particle and coarse particle. The calcium was leached by bulk dissolution in the coarse particle and by surface controlled reaction in fine particle. The leaching rate was slow in coarse particle and fast in fine particle. Therefore, the high pH solution, that is, over 12, was obtained in fine particle.cle.e.

• Journal of the Korean Ceramic Society
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• v.33 no.11
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• pp.1276-1284
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• 1996

Ultrafine calcim carbonate powders with the size of 0.05~0.1 ${\mu}{\textrm}{m}$ and the calcite phase were prepared by the nozzle spouting method which was conducted by spouting calcium hydroxide slurry in reactor filled with CO2 gas. Well dispersed ultra-fine particles were synthesized in condition of high Ca(OH)2 concentration of the slurry ( 0.5wt%) synthesized calcium carbonate powder was shown the large particle size with agglo-meration.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.9
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• pp.3981-3986
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• 2014

Ganoderma lucidum polysaccharides (GLP) extracted from Ganoderma lucidum have been shown to induce cell death in some kinds of cancer cells. This study investigated the cytotoxic and apoptotic effect of GLP on HCT-116 human colon cancer cells and the molecular mechanisms involved. Cell proliferation, cell migration, lactate dehydrogenase (LDH) levels and intracellular free calcium levels ($[Ca^{2+}]i$) were determined by MTT, wound-healing, LDH release and fluorescence assays, respectively. Cell apoptosis was observed by scanning and transmission electron microscopy. For the mechanism studies, caspase-8 activation, and Fas and caspase-3 expression were evaluated. Treatment of HCT-116 cells with various concentrations of GLP (0.625-5 mg/mL) resulted in a significant decrease in cell viability (P< 0.01). This study showed that the antitumor activity of GLP was related to cell migration inhibition, cell morphology changes, intracellular $Ca^{2+}$ elevation and LDH release. Also, increase in the levels of caspase-8 activity was involved in GLP-induced apoptosis. Western blotting indicated that Fas and caspase-3 protein expression was up-regulated after exposure to GLP. This investigation demonstrated for the first time that GLP shows prominent anticancer activities against the HCT-116 human colon cancer cell line through triggering intracellular calcium release and the death receptor pathway.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.204-209
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• 2003

Utilization of soluble protein recovered from surimi wastewater using calcium powder of cuttle bone were examined. The crude ash content of the heat-induced surimi gel was increased linearly by increasing substitution ratio of recovered protein-ATC toward commercial surimi. Moisture (approximately $76\%$) and lipid $(0.2\%)$ contents were not change, but their protein contents were decreased 15.7 to $14.3\%$ depend on increasing of substitution ratio. The white index of the heat-induced surimi gel by color meter was increased up to $10\%$ of substitution ratio. There were no difference between $0\%\;and\;5\%$ substituted surimi gel in the gel strength. The sensory score on white index and texture of the heat-induced surimi gel did not change in 0 to $10\%$ as a substitution ratio of recovered protein-ATC toward commercial surimi, while decreased in more $15\%.$ The optimal substitution ratio of recovered protein-ATC as a bulking agent was $10\%.$ The heat-induced surimi gel prepared with $10\%$ substitution of recovered protein-ATC was similar to the content and composition of total amino. acids, and superior to calcium content and the ratio of calcium and phosphorus toward those of commercial surimi.