• Food Science and Preservation
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• v.6 no.3
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• pp.333-338
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• 1999

This studies were conducted to investigate the effects of calcium lactate and calcium acetate on the duality and shelf-life of kimchi. Kimchi was prepared by adding 0.5% mixtures of calcium lactate and calcium acetate at ratios of 04:0, 0.4:0.1, 0.3:0.2. 0.2:0.3, 0.1:0.4, 0:0.5, and fermented at 10$^{\circ}C$. The shelf-life of the kimchi by adding the mixtures of calcium lactate and calcium acetate at the ratio of 0.4:0.1, 0.3:0.2, 0.2:0.1 can be extended approximately 5 days. And, calcium contents of the kimchi tissue increased 46 to 66% against the control products. And also, demage of parenchyma cell was lower, the scores of crispness and overall taste of the kimchi treated were higher than those of the control.

• Food Science and Preservation
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• v.22 no.3
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• pp.452-457
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• 2015

This study was conducted to evaluate the quality characteristics of pickled radish wrap supplemented with calcium chloride ($CaCl_2$) at different concentrations. With $CaCl_2$ supplementation, initial pH and acidity were 3.8~4.0 and 2.7~3.0% (w/v), respectively. During the 28 day-preservation at $4^{\circ}C$ or $50^{\circ}C$, the initial pH and acidity were maintained. However, when the pickled radish wrap was preserved at $25^{\circ}C$, it had lower pH (by 0.5) and higher acidity (by 1.9~2.2%) when compared with the initial values. The difference in color (${\Delta}E$-value) of the pickled radish wrap preserved at $50^{\circ}C$ was significant (${\Delta}E$-value 23~27), though the hardness of the sample prepared at $4^{\circ}C$ or $25^{\circ}C$ showed no distinguishable differences at various concentrations of $CaCl_2$ supplementation (0.1, 0.2, 03, 0.4, and 0.5%). However, once preserved at $50^{\circ}C$, it resulted in the greater hardness with the higher concentrations of $CaCl_2$ supplementation. In terms of softness, the overall trend in changes was similar to the hardness. A sensory evaluation using the samples preserved at $4^{\circ}C$ for 28 days demonstrated that the preparation with 0.4% $CaCl_2$ ranked highest in taste, hardness and overall acceptability. It wass suggested that supplementation with 0.4% $CaCl_2$ would be most appropriate to improve the textural properties of pickled radish wrap while maintaining its organoleptic quality.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.94-100
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• 2003

Preparation method and characteristics of high quality Korean pickled cucumber made with acetic acid-treated cuttle bone powder (KPCCP) were examined and compared to those of Korean pickled cucumber prepared by traditional methods (control). Optimal concentration of acetic acid-treated cuttle bone powder for KPCCP preparation was revealed as 10%. Salt concentration of KPCCP fermented for 3 days was 4.5%, slightly higher than that of the control, whereas that of KPCCP fermented for over 6 day was about 4.8%, similar to that of the control. The pH, greenness, and hardness of korean pickled cucumber decreased during fermentation, with the control showing a greater extent of decrease than KPCCP Total acidity and alcohol insoluble calcium contents increased during fermentation, with KPCCP showing higher extent of increase. These results indicate that quality of KPCCP is superior to that of Korean pickled cucumber prepared by traditional methods.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.255-258
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• 2000

본 연구는 육성돈에 있어 인분해효소인 phytase의 첨가가 환경친화성사료개발을 위한 기초자료로 사용하기 위해 영양소 이용률을 측정하였다. 대조구는 옥수수-대두박의 육성돈 사료이고, 처리구는 대조구 사료에 Phytase의 첨가 수준을 500 unit 및 1,000 unit을 첨가한 구로 3×3 Latin Square 방법으로 실시하였다. 건물과 질소에 대한 소화율에서는 각 처리구간에 유의적인 차이가 없었다(P>0.05). 회분, 칼슘 및 인의 소화율의 경우 phytase 첨가구가 대조구에 비해 높은 수준을 보였다(P<0.05). 돼지가 섭취한 인의 양은 phytase 첨가구가 대조구에 비해 증가하였다. 또한 인의 흡수량에서 phytase 첨가구가 대조구에 비해 높았다(P<0.05) 분과 뇨의 총 인 배설량은 유의적인 차이를 나타내지 않았다. 칼슘의 섭취량은 처리구가 대조구에 비해 높았다. 칼슘의 분 배설량은 각 처리구간에 별 다른 차이를 보이지 않았으나(P>0.05), 뇨의 배설량은 처리구가 대조구보다 적은 양이 배설되었다. 소화된 아미노산 중 cystine, isoleucine, tyrosine, phenylalanine은 처리구가 대조구에 비해 소화율이 현저히 증가된 것을 알 수 있었다(P<0.05). Asparagine, threonine, serine, methionine, leucine의 경우 phytase를 500 unit 첨가한 구가 높은 소화율을 나타내었다(P<0.05). 한편 lysine, histidine, arginine 등의 다른 아미노산은 처리구가 대조구보다 약간의 소화율 증가를 보였으나 통계적 유의차는 나타나지 않았다(P>0.05). 결론적으로 인분해효소 phytase를 사료내 첨가하므로서 분중 영양소를 줄일 수 있는 환경친화성 사료를 개발 가능하다고 사료된다. 체결홈이 형성된 체결부를 갖는 안경집과 이것에 결합되는 체결구가 마련되어 개폐되는 커버가 형성된 케이스로 구성된다.로 금형설계 및 제작기간을 단축하고자 한다.ere demonstrated in rats after i.c.v., intraperitoneally and orally administration, respectively. The antiepileptical effects by the combination of compounds from ginseng; were compared with the iuluence of Rg1, Rb1, Rc and with the well known antiepileptical drugs such as carbamazepine, valproic acid. The base for the research is obtained by using the WAG/Rij strain (Luijtelaar, Coenen, Kuznetcova), an excellent genetic model for human generalized absence epilepsy. The improving action of gensinosides was effectively demonstrated on the model of electrical kindling of amygdala of WAG/Rij rats with genetically determined absences, and the influences of ginsenosides on the slow wave discharges have also been being investigated. The different characteristics of a kindling process exerted in the sex-dif

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.273-284
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• 2005

Coagulation and precipitation process by using lime$(Ca(OH)_2)$ and calcium carbonate $(CaCO_3)$ were applied to remove heavy metals from groundwater in laboratory scale. From results of batch tests, by the addition of $0.3\;wt.\%$ lime, more than $90\%$ of As and Mn were removed and $70-80\%$ of Cd and Zn were removed by using $0.5\;wt.\%$ of lime. Removal efficiency of Pb almost reached $100\%$ with only $0.1\;wt.\%$ of calcium carbonate and more than $93\%$ of Cd were removed by the addition of $0.1\;wt.\%$of calcium carbonate. Pilot scale column experiments were performed to remove heavy metals in the separation process of precipitated Hoc to supernatant after the coagulation/ precipitation. For lime as a coagulant, more than $99\%$of As were removed from artificial groundwater and removal efficiencies of Cd, Mn, and Zn were over $80\%$. By using calcium carbonate, more than $95\%$ of Cd and Pb were removed in column experiment. Fe and Mn contaminated groundwater taken from a real landfill site, Ulsan was used for the column experiment and more than $99\%$ of Fe and Mn were removed by the addition of $1\;wt.\%$ lime in column experiment, suggesting that the coagulation/precipitation process by using lime and calcium carbonate have a great possibility to remove heavy metals from contaminated groundwater.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.4
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• pp.302-308
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• 2000

Stable amorphous calcium carbonate were synthesized from the serial work for the synthetic conditions such as concentration of solution, reaction temperature, aging time and pH of mother liquor. By using this as a precusor, calcite, aragonite and vaterite crystal particles were obtained in the water from adequate crystallization conditions. Furthermore, characterization for flourescence were performed by using crystals which were crystallized from the Sn dopped amorphous calcium carbonate. Calcite showed the most intensive emission and the center of emission wavelength was 464 nm with pure blue color. Calcite is expected to be used as phosphor for flourescent lamp because the maximum emission intensity was obtained from the excitation with 255 nm wavelength.

• 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.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1347-1352
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• 1996

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.756-765
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• 2004

We present extraction process and reaction mechanism of boric acid from one of calcium borate ores, colemanite by reaction with sulfuric acid. Colemanite has been fully decomposed under pH 5 with sufficiency amount of sulfuric acid, more than the amount stoichiometrically required. Calcium sulfate was separated out, leaving boron in the liquid phase after sulfuric acid addition. The extraction process of boric acid was affected by dissolution temperature and time, amount of sulfuric acid and ammonium sulfate, pH and a degree of concentration before recrystallization. The $SiO_2$ of the impurities which colemanite contains was insoluble so that it was separated out with calcium sulfate from liquid phase. The species of $CaO,\;Al_2O_3,\;Fe_2O_3,\;MgO$ were remained in a liquid phase after reaction with sulfuric acid. These impurities were separated out by addition of ammonia to the liquid phase, funhermore, boric acid was produced by process of pH adjustments and acidification, concentration, and recrystallization.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.85-92
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• 2021

The purpose of this study is to investigate the properties of hardener-free epoxy-modified mortars(EMMs) using ground granulated blast furnace slag(GGBFS) and alkali activators. The hardener-free EMMs with a GGBFS content of 20% using 4 types of alkali activators were prepared with various polymer-binder ratios, and tested for strengths, water absorption, carbonation depth, chloride ion and H2SO4 penetration depth. The conclusions obtained from the test results are summarized as follows: The compressive strength of the EMMs with a GGBFS content of 20% attains a maximum at a polymer-binder ratio of 10%. The flexural strength of the hardener-free EMMs using Ca(OH)2 as a alkali activator is improved with increasing polymer-binder ratios. However, the flexural strength of the EMMs using NaCO3, Na2SO4 and Li2CO3 is gradually decreased with increasing polymer-binder ratios. Regardless of the type of alkali activator, the water absorption, chloride ion penetration and carbonation depth are remarkably decreased with increasing polymer-binder ratios due to the epoxy film formed in the EMMs. The H2SO4 penetration depth of the hardener-free EMMs with a GGBFS content of 20% is gradually increased with increasing polymer-binder ratio. In this study, the properties of hardener-free EMMs using Ca(OH)2 as a alkali activator are more excellent than those of other alkali activators.