• Journal of Chest Surgery
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• v.24 no.9
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• pp.837-842
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• 1991

Calcification is a major problem in glutaraldehyde-preserved bioprosthetic valves. We have used bovine pericardium processed in a solution containing 0.625% glutaraldehyde, 0.05M HEPES buffer and 0.26% magnesium chloride in saline. And, we also treated the glutaraldehyde-preserved bovine pericardium with a surfactant, Triton X - 100 to reduce calcification. To evaluate the degree of calcification. 4 kinds of pericardial xenografts, group I [Xenomedica, equine pericardial xenografts], group II [0.625% glutaraldehyde-preserved bovine pericardiums], group III [0.5% Triton X - 100 treated bovine pericardiums], and group IV [1.2% Triton X - 100 treated bovine pericardiums] were implanted in subcutaneous layer of growing rabbits, and they were explanted about 3 months later. The mean calcium contents[%/mg of dry tissue] of 0.5% and 1.2% Triton X - 100 treated bovine pericardiums [80.0$\pm$27.1%: 78.6$\pm$47.0% respectively] were lower than those of glutaraldehyde-preserved bovine pericardiums[126.2$\pm$29.8] [p=0.05]. Thus, under the conditions of subcutaneous implantation in rabbits, Triton X - 100 was efficient in calcification mitigation.

• Journal of the Korean Ceramic Society
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• v.53 no.1
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• pp.7-12
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• 2016

In this paper, we have developed a simple, new and economical carbonation method to synthesize a pure form of aragonite needles using dolomite raw materials. The obtained aragonite Precipitated Calcium Carbonate (PCC) was characterized by XRD and SEM, for the measurement of morphology, particle size, and aspect ratio (ratio of length to diameter of the particles). The synthesis of aragonite PCC involves two steps. At first, after calcinated dolomite fine powder was dissolved in water for hydration, the hydrated solution was mixed with aqueous solution of magnesium chloride at $80^{\circ}C$, and then $CO_2$ was bubbled into the suspension for 3 h to produce aragonite PCC. Finally, aragonite type precipitated calcium carbonate can be synthesized from natural dolomite via a simple carbonation process, yielding product with average particle size of $30-40{\mu}m$.

• Textile Coloration and Finishing
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• v.17 no.5 s.84
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• pp.20-25
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• 2005

The colorants were extracted from black soybean using a buffer solution. Dyeing properties and the fastness of silk fabric dyed with black soybean extracts were investigated. K/S values of dyed fabric were increased with concentration of black soybean extracts. Magnesium sulfate, nickel sulfate and calcium chloride as mordants are used to obtain reddish purple color. Optimum dyeing temperature of black soybean extracts was $30^{\circ}C$. Fastness were generally good except for light fastness which was extremely poor.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.1002-1008
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• 1999

Essential metabolic functions have been identified for seven macrominerals (calcirum, phosprorus, magnesium, sodium, potassium, chloride, and sulfur), and eight microminerals (cobalt, copper, iodine, iron, manganese, molybdenum, selenium, and zinc). Major functions for each of these minerals are summarized. Considerable research suggests that chromium is also essential and that it functions by facilitating insulin activity. Studies are reviewed which indicate that chromium supplementation of animal diets may: 1) increase glucose removal from blood, 2) reduce carcass fat and increase lean in nonruminants, 3) alter egg cholesterol content, and 4) enhance immunity and disease resistance in ruminants. A number of other minerals including nickel, boron, vanadium, arsenic, silicon, lithum, and lead have been reported to be essential, but specific metabolic functions have not been defined for any of these elements. Limited research in poultry suggests that boron may be of practical significance in some instances.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.573-583
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• 2000

In order to investigate the characteristics of PM(sub)2.5 in the background area, the following pollutant were measured from February 1996 to June 1999 in Kanghwa: PM(sub)2.5 mass, sulfate, nitrate, chloride, ammonium, sodium, calcium, magnesium and potassium. The mean concentration of PM(sub)2.5 mass was 25.8$\pm$1.2$\mu\textrm{g}$/㎥(range 5.18~85.74). This value was higher than the annual PM(sub)2.5 US NAAQS(15$\mu\textrm{g}$/㎥) and the total number of samples higher than the 24-h PM(sub)2.5 US NAAQS(65$\mu\textrm{g}$/㎥) was seven. PM(sub)2.5 masses also showed temporal variations both yearly and seasonally. Total water soluble ions constituted about 45% of PM(sub)2.5 miss, and sulfate, nitrate and ammonium were main components in water soluble ions. Compared with the literature data from other areas, the measured PM(sub)2.5 concentrations were relatively high.

• YAKHAK HOEJI
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• v.45 no.1
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• pp.23-28
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• 2001

Hydrotalcite was prepared by reacting with sodium carbonate, magnesium hydroxide and aluminum chloride solutions in this study. The optimum synthesis conditions based on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of hydrotalcite were as follows ; reacting temperature : 63~9$0^{\circ}C$, concentration of reactant solution : 18.20~19.82%, molar concentration ratio of two reactants [Mg(OH)$_2$] / (AICl$_3$.6$H_2O$) : 6.0, temperature of washing water : 29.0-34.4$^{\circ}C$, drying temperature : 56-77.6$^{\circ}C$. The physicochemical properties of hydrotalcite as medicine were studied by use of chemical analysis, bulk volume test and acid consuming capacity measurements.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.412-418
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• 2010

This paper presents the results of experimental work on both mechanical properties and durability of concrete or mortar incorporating silica fume. The aim of this study was to investigate the effect of replacement of silica fume on the performance of hardened concrete or mortar. The replacement levels of silica fume that replaced cement in this work were 0%, 5%, 10% and 15%, respectively. The results of this study indicate that both mechanical properties and durability of concrete are greatly dependent on the replacement levels of silica fume. As the replacement level of silica fume increased, the mechanical properties including compressive and flexural strengths, and static modulus of elasticity were proportionally enhanced. Furthermore, it was found that silica fume had some beneficial effects on the resistances to both chloride ions penetration and sodium sulfate attack. However, it exhibited poor resistances to both freezing-thawing action and magnesium sulfate attack.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.62-67
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• 1995

The combustion characteristics of cellulose Insulation treated with several metal complexes such as Aluminium hydroxide, Cupric sulfate pentahydrate, Magnesium sulfate heptahydrate, Manganese chloride tetrahydrate and Tnisodium phosphate dodecahydrate are studied to evaluate the effectiveness as a potential flame retardant for cellulosic materials. In this study, we found that LOI values of cellulosic materials treated with the metal complexes are generally increased with the increase of their content. At high concentration, CS(24% ) and SP(24% ) show high LOI values, suggesting resistance to flame spread, The materials examined in this study were found to be relatively more resistance to smouldering and flaming combustion in comparision with untreated cellulosic material. The flammability behavior of the materials exhibits combustion process as follows : LOI$\rightarrow$smouldering region$\rightarrow$smouldering-flaming spread region$\rightarrow$flame spread region.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.6
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• pp.276-280
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• 2001

This paper presents the result of a study on the distribution characteristics of salt contaminants in the west coast region, from Inchon to Yearsoo, of South Korea. To evaluate the distribution characteristics of salt contaminants, we had measured the equivalent salt deposit density(ESDD) with brush wiping method for thirteen month(from May 1999 to June 2000). Under the consideration on the measuring interval and method, normalization method was applied for the ESDD data. Besides the measurement, the chemical analysis (chromatography) was carried to investigate the relationship, between the electrical property and the amount of specific ingredient, such as sodium, magnesium and chloride. From the result, we could get the representative value of contamination for each site and distribution characteristics of salt contaminants with the distance from sea in the west coast.

• Bulletin of the Korean Chemical Society
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• v.18 no.2
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• pp.203-208
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• 1997

A series of MgO-SiO2 catalysts were prepared by coprecipitation from the mixed solution of magnesium chloride and sodium silicate. Some of the sample were modified with 1 N H2SO4 and used as modified catalysts. The addition of MgO to SiO2 caused the increase of acidity and the shift of O-H and Si-O stretching bands of the silanol group to a lower frequency in proportion to the MgO content. The acid structure of MgO-SiO2 agreed with that proposed by Tanabe et al.. Catalytic activity for 2-propanol dehydration increased in relation to the increase of acidity and band shift to a lower frequency.